| 1. |
- Klionsky, Daniel J., et al.
(författare)
-
Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
-
Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
-
Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
|
|
| 2. |
- Deng, Min, et al.
(författare)
-
Genome-wide association analyses in Han Chinese identify two new susceptibility loci for amyotrophic lateral sclerosis
- 2013
-
Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 45:6, s. 697-
-
Tidskriftsartikel (refereegranskat)abstract
- To identify susceptibility genes for amyotrophic lateral sclerosis (ALS), we conducted a genome-wide association study (GWAS) in 506 individuals with sporadic ALS and 1,859 controls of Han Chinese ancestry. Ninety top SNPs suggested by the current GWAS and 6 SNPs identified by previous GWAS were analyzed in an independent cohort of 706 individuals with ALS and 1,777 controls of Han Chinese ancestry. We discovered two new susceptibility loci for ALS at 1q32 (CAMK1G, rs6703183, P-combined = 2.92 x 10(-8), odds ratio (OR) = 1.31) and 22p11 (CABIN1 and SUSD2, rs8141797, P-combined = 2.35 x 10(-9), OR = 1.52). These two loci explain 12.48% of the overall variance in disease risk in the Han Chinese population. We found no association evidence for the previously reported loci in the Han Chinese population, suggesting genetic heterogeneity of disease susceptibility for ALS between ancestry groups. Our study identifies two new susceptibility loci and suggests new pathogenic mechanisms of ALS.
|
|
| 3. |
- Li, Wenting, et al.
(författare)
-
Effects of prenatal exposure to five parabens on neonatal thyroid function and birth weight : Evidence from SMBCS study
- 2020
-
Ingår i: Environmental Research. - : Academic Press. - 0013-9351 .- 1096-0953. ; 188
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Parabens, suspected as endocrine-disrupting chemicals, are nearly ubiquitous in the human body and exposure to these chemicals during pregnancy may disrupt thyroid hormones homeostasis and even affect fetal growth, although the impacts are still unclear.OBJECTIVES: We aimed to estimate associations of maternal urinary paraben concentrations with cord serum thyroid hormones and birth weight.METHODS: A subset of 437 mother-newborn pairs were included from a prospective birth cohort with five parabens quantified in maternal urine and seven thyroid function indicators measured in cord serum samples. Multivariable linear regression models and elastic net regression (ENR) models were applied to explore associations between individual and mixtures of prenatal urinary paraben concentrations and thyroid hormones and birth weight, respectively.RESULTS: Maternal urinary ethyl-paraben (EtP) concentrations were associated with increased cord serum total triiodothyronine levels (TT3) [percent change: 1.51%; 95% confidence interval (CI): 0.20%, 2.74%; p=0.017]. Urinary propyl-paraben (PrP) levels predicted higher thyroid peroxidase antibodies (percent change: 4.19%, 95% CI: 0.20%, 8.44%; p=0.041). Maternal urinary EtP and butyl-paraben (BuP) concentrations were significantly positively associated with birth weight [regression coefficient, (β)=40.9g, 95% CI: 3.99, 76.6; p=0.030; β=62.1g, 95% CI: 8.70, 115; p=0.023, for EtP and BuP, respectively]. In sex-stratified analyses, positive relationship between EtP levels and birth weight was observed in boys. Urinary EtP concentrations predicted higher TT3 levels in cord serum samples, assessing parabens as a chemical mixture with ENR models.CONCLUSIONS: Prenatal exposure to parabens may affect thyroid hormone indicators with increased serum TT3 levels and associate with higher birth weight, especially in boys. The underlying biological mechanisms and effects of prenatal paraben exposures on disruption of thyroid function homeostasis and potential impacts of childhood growth and development needed to be further investigated.
|
|
| 4. |
- Liu, Zhiying, et al.
(författare)
-
On Gate Capacitance of Nanotube Networks
- 2011
-
Ingår i: IEEE Electron Device Letters. - : IEEE. - 0741-3106 .- 1558-0563. ; 32:5, s. 641-643
-
Tidskriftsartikel (refereegranskat)abstract
- This letter presents a systematic investigation of the gate capacitance C-G of thin-film transistors (TFTs) based on randomly distributed single-walled carbon nanotubes (SWCNTs) in the channel. In order to reduce false counting of SWCNTs that do not contribute to current conduction, C-G is directly measured on the TFTs using a well-established method for MOSFETs. Frequency dispersion of C-G is observed, and it is found to depend on the percolation behavior in SWCNT networks. This dependence can be accounted for using an RC transmission line model. These results are of important implications for the determination of carrier mobility in nanoparticle-based TFTs.
|
|
| 5. |
- Chen, Fei'er, et al.
(författare)
-
The effects of PM2.5 on asthmatic and allergic diseases or symptoms in preschool children of six Chinese cities, based on China, Children, Homes and Health (CCHH) project
- 2018
-
Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 232, s. 329-337
-
Tidskriftsartikel (refereegranskat)abstract
- The urbanization and industrialization in China is accompanied by bad air quality, and the prevalence of asthma in Chinese children has been increasing in recent years. To investigate the associations between ambient PM2.5 levels and asthmatic and allergic diseases or symptoms in preschool children in China, we assigned PM2.5 exposure data from the Global Burden of Disease (GBD) project to 205 kindergartens at a spatial resolution of 0.1° × 0.1° in six cities in China (Shanghai, Nanjing, Chongqing, Changsha, Urumqi, and Taiyuan). A hierarchical multiple logistical regression model was applied to analyze the associations between kindergarten-level PM2.5 exposure and individual-level outcomes of asthmatic and allergic symptoms. The individual-level variables, including gender, age, family history of asthma and allergic diseases, breastfeeding, parental smoking, indoor dampness, interior decoration pollution, household annual income, and city-level variable-annual temperature were adjusted. A total of 30,759 children (average age 4.6 years, 51.7% boys) were enrolled in this study. Apart from family history, indoor dampness, and decoration as predominant risk factors, we found that an increase of 10 μg/m3 of the annual PM2.5 was positively associated with the prevalence of allergic rhinitis by an odds ratio (OR) of 1.20 (95% confidence interval [CI] 1.11, 1.29) and diagnosed asthma by OR of 1.10 (95% CI 1.03, 1.18). Those who lived in non-urban (vs. urban) areas were exposed to more severe indoor air pollution arising from biomass combustion and had significantly higher ORs between PM2.5 and allergic rhinitis and current rhinitis. Our study suggested that long-term exposure to PM2.5 might increase the risks of asthmatic and allergic diseases or symptoms in preschool children in China. Compared to those living in urban areas, children living in suburban or rural areas had a higher risk of PM2.5 exposure.
|
|
| 6. |
- Chen, Si, et al.
(författare)
-
A graphene field-effect capacitor sensor in electrolyte
- 2012
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 101:15, s. 154106-
-
Tidskriftsartikel (refereegranskat)abstract
- The unique electronic properties of graphene are exploited for field-effect sensing in both capacitor and transistor modes when operating the sensor device in electrolyte. The device is fabricated using large-area graphene thin films prepared by means of layer-by-layer stacking. Although essentially the same device, its operation in the capacitor mode is found to yield more information than in the transistor mode. The capacitor sensor can simultaneously detect the variations of surface potential and electrical-double-layer capacitance at the graphene/electrolyte interface when altering the ion concentration. The capacitor-mode operation further facilitates studies of the molecular binding-adsorption kinetics by monitoring the capacitance transient
|
|
| 7. |
- Guo, Jianqiu, et al.
(författare)
-
Anthropometric measures at age 3 years in associations with prenatal and postnatal exposures to chlorophenols
- 2019
-
Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 228, s. 204-211
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Chlorophenols (CPs), suspected as endocrine disrupting chemicals, exposure during early life may contribute to body size. However, limited human data with inconsistent findings have examined the developmental effects of CPs exposure.Objective: To explore associations between prenatal and postnatal CPs exposure and anthropometric parameters in children aged 3 years.Methods: A subset of 377 mother-child pairs with urinary five CP concentrations were enrolled from a prospective birth cohort. Generalized linear models were conducted to evaluate associations of CPs exposure with children's anthropometric measures.Results: Maternal urinary 2,4,6-trichlorophenol (2,4,6-TCP) concentrations were significantly negatively associated with weight z scores [regression coefficient (beta)=-0.51, 95% confidence interval (Cl): -0.96, -0.05; p = 0.01], weight for height z scores (beta = -0.54, 95% Cl:-1.02, -0.06; p= 0.01) and body mass index (BMI) z scores (beta = -0.53, 95% CI;-1.03, 0.03; p = 0.01) of children aged 3 years, after adjustment for potential confounders and postnatal CPs exposure. In the sex-stratified analyses, these inverse associations remained among boys, while in girls, positive associations of prenatal 2,4,6-TCP exposure with weight for height z scores and BMI z scores were observed. Postnatal exposure to 2,5-diclorophenol (2,5-DCP) was positively associated with weight z scores (beta = 0.26, 95% CI: 0.02, 0.50; p = 0.04), after controlling for possible confounders and maternal CPs exposure during pregnancy. Considering potential sex-specific effects, these associations were only observed in girls.Conclusions: Our findings indicate that prenatal 2,4,6-TCP exposure and postnatal 2,5-DCP exposure may have adverse and sex-specific effects on children's physical development.
|
|
| 8. |
- Guo, Jianqiu, et al.
(författare)
-
Associations of melamine and cyanuric acid exposure with markers of kidney function in adults : Results from NHANES 2003-2004
- 2020
-
Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 141
-
Tidskriftsartikel (refereegranskat)abstract
- Higher melamine exposure may increase the risk of kidney stone formation and kidney injury in infants, but little is known about the potential nephrotoxic effects of environmental low-dose melamine and its derivative exposure on kidney function of adults in the general population. Our objective was to assess associations between urinary concentrations of melamine and its derivative, cyanuric acid, and kidney function through analyzing the data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004. Information on 298 participants aged ≥20 years was utilized. Urinary melamine and cyanuric acid levels were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) were calculated to reflect kidney function. Covariate-adjusted creatinine standardization concentrations accounting for sex, race, age, race/ethically, and body mass index, was employed to control potential confounding of kidney function. Multivariable linear regression models were conducted to estimate associations of covariate-adjusted creatinine standardization urinary melamine and cyanuric acid concentrations with eGFR and UACR. Log-binomial regression models were performed to estimate risks of impaired kidney function and hypertension associated with urinary melamine and cyanuric acid levels. The geometric mean values of urinary melamine and cyanuric acid concentrations were 1.51 μg/L [95% confidence interval (CI): 1.21 μg/L, 1.89 μg/L] and 5.86 μg/L (95% CI: 5.34 μg/L, 6.44 μg/L), respectively. The median value of estimated daily intake (EDI) for melamine was 0.06 (ranging from undetectable to 1.11) μg/kg body weight/day calculated by urinary concentration and creatinine excretion accounting for sex and body weight. Adults in the fourth quartile of melamine and cyanuric acid exposure had 0.142 mL/min/1.73 m2 (95% CI: -0.271, -0.014) and 0.106 mL/min/1.73 m2 (95% CI: -0.020, 0.006) lower eGFR for melamine and cyanuric acid, respectively, compared to participants in the first quartile of exposure with adjustment for potential confounders. To our best knowledge, this is the first study to report associations between melamine and its derivative and kidney function of the U.S. adults from NHANES 2003-2004. The suggestive evidence revealed that individuals with high melamine exposure had lower eGFR than those with low melamine exposure, although no significant association between melamine and cyanuric acid exposure and markers of kidney function was observed. These findings should be interpreted with caution regarding the possible reverse causality.
|
|
| 9. |
- Guo, Jianqiu, et al.
(författare)
-
Associations of prenatal and childhood chlorpyrifos exposure with Neurodevelopment of 3-year-old children
- 2019
-
Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 251, s. 538-546
-
Tidskriftsartikel (refereegranskat)abstract
- Chlorpyrifos (CPF), an organophosphate insecticide, has been linked to adverse neurodevelopmental effects in animal studies. However, little is known about long-term neurotoxicity of early-life CPF exposure in humans. We aimed to evaluate the associations of both prenatal and early childhood CPF exposure with neurodevelopment of children. In this observational study based on Sheyang Mini Birth Cohort, pregnant women were recruited from an agricultural region between June 2009 and January 2010, and their children were followed up from birth to age three. Urinary 3,5,6-Trichloro-2-pyridinol (TCPy), a specific metabolite of CPF, was quantified using large-volume-injection gas chromatography tandem mass spectrometry. Developmental quotients (DQs) of children in motor, adaptive, language, and social areas were assessed by trained pediatricians. Data from 377 mother-child pairs were used in the current study. Associations between CPF exposure and neurodevelopmental indicators were estimated using generalized linear models with adjustment for potential confounders. The median concentrations of TCPy in maternal and children's urine were 5.39 mu g/L and 5.34 mu g/L, respectively. No statistically significant association was found between maternal urinary TCPy concentrations and children neurodevelopment. While for postnatal exposure, we found lower motor area DQ score 0.61 [95% confidence interval (CI): -1.13, -0.09; p = 0.02] and social area DQ score 0.55 (95% CI: -1.07, -0.03; p = 0.04) per one-unit increase in the In-transformed childhood urinary TCPy concentrations. Further stratification by sex indicated that the inverse associations were only observed in boys, but not in girls. Our findings suggest that adverse neurodevelopmental effects were associated with early childhood CPF exposure, but not prenatal exposure. Additional longitudinal studies are needed to replicate these results and to further understand the toxicological mechanisms of CPF.
|
|
| 10. |
- Guo, Jianqiu, et al.
(författare)
-
Early life triclosan exposure and neurodevelopment of children at 3 years in a prospective birth cohort
- 2020
-
Ingår i: International journal of hygiene and environmental health. - : Urban & Fischer. - 1438-4639 .- 1618-131X. ; 224
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Early life exposure to triclosan, an emerging endocrine disrupting chemical, may adversely impact childhood neurodevelopment, but limited epidemiologic studies have examined the associations.OBJECTIVE: We evaluated the associations between prenatal and postnatal triclosan exposure and child neurodevelopment at 3 years.METHODS: The study included 377 mother-child pairs who participated in Sheyang Mini Birth Cohort Study (SMBCS), a longitudinal birth cohort in China. Triclosan concentrations in maternal and 3-year-old child urine samples were quantified using gas chromatography-tandem mass spectrometry (GC-MS/MS). Gesell Developmental Schedules (GDS) were used to assess child neurodevelopment at 3 years of age. Multivariate linear regression models were applied to estimate associations of prenatal and postnatal urinary triclosan concentrations with children's developmental quotients (DQs).RESULTS: Detection frequencies of triclosan in maternal and childhood urine samples were 100% and 99.5%, respectively. The median values of prenatal and postnatal urinary triclosan levels were 0.65 and 0.44 μg/L, respectively. One ln-unit increase of maternal urinary triclosan concentration was associated with increase of DQ scores in motor area of children (regression coefficient, β = 0.28, 95% confidence interval, CI: 0.03, 0.54; p = 0.03). In sex-stratified analyses, maternal urinary triclosan levels were significantly related to increases in DQ scores in motor area among boys (β = 0.25, 95%CI: 0.01, 0.50; p = 0.04), while postnatal urinary triclosan concentrations were inversely associated with DQ scores in social area in boys (β = -0.37, 95%CI: -0.72, -0.03; p = 0.03).CONCLUSIONS: The findings suggested that prenatal triclosan exposure predicted increases in motor scores, while postnatal triclosan exposure was related to reductions in social scores of 3-year-old children. These associations were only observed in boys. The biological mechanisms linking triclosan exposure to neurodevelopment await further studies.
|
|
| 11. |
- Guo, Jianqiu, et al.
(författare)
-
Maternal and childhood urinary phenol concentrations, neonatal thyroid function, and behavioral problems at 10 years of age : The SMBCS study
- 2020
-
Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 743
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Environmental phenols, bisphenol A (BPA), triclosan (TCS), and benzophenone-3 (BP-3), are known as emerging endocrine-disrupting chemicals; however, their impacts on thyroid hormones and children's neurobehaviors are still unclear.OBJECTIVES: We aimed to examine the associations of prenatal and childhood exposure to phenols with neonatal thyroid function and childhood behavioral problems aged 10 years.METHODS: A total of 386 mother-singleton pairs were included from Sheyang Mini Birth Cohort Study (SMBCS), a longitudinal birth cohort in China. We quantified urinary BPA, TCS and BP-3 concentrations in maternal and 10-year-old children's urine samples using gas chromatography tandem mass spectrometry and thyroid function parameters in cord serum samples. Caregivers completed the Strength and Difficulties Questionnaire (SDQ) for their children at 10 years of age. Multivariable linear regression models and logistic regression models were applied to estimate associations of urinary phenol concentrations with thyroid hormones and risks of children's behavioral problems, respectively.RESULTS: The median values of urinary BPA, TCS and BP-3 concentrations for pregnant women were 1.75 μg/L, 0.54 μg/L and 0.37 μg/L, while 1.29 μg/L, 6.64 μg/L and 1.39 μg/L for children, respectively. Maternal urinary BPA concentrations were in associations with 1.00% [95% confidence interval (CI): 0.20%, 1.92%] increases in cord serum FT4 concentrations and significantly associated with increased risks of total difficulties [odds ratio (OR): 1.45, 95% CI: 1.07, 1.97], while maternal urinary levels of BP-3 were significantly related to poorer prosocial behaviors (OR: 1.58, 95% CI: 1.04, 2.39) of children at 10 years of age. In sex-stratified analyses, maternal urinary BPA concentrations were related to increased total difficulty subscales only in boys.CONCLUSIONS: The findings indicated that higher prenatal urinary BPA concentrations were associated with increased risks of total difficulties, especially in boys and maternal urinary BP-3 concentrations were related to poorer prosocial behaviors at 10 years.
|
|
| 12. |
- Guo, Jianqiu, et al.
(författare)
-
Prenatal exposure to multiple phenolic compounds, fetal reproductive hormones, and the second to fourth digit ratio of children aged 10 years in a prospective birth cohort
- 2021
-
Ingår i: Chemosphere. - : Pergamon Press. - 0045-6535 .- 1879-1298. ; 263
-
Tidskriftsartikel (refereegranskat)abstract
- Select phenols are known to possess hormone-disrupting properties, but no previous study has addressed the potential effects of prenatal exposure to phenol mixtures on fetal reproductive hormones and children's second to fourth digit (2D: 4D) ratio, a marker for in utero testosterone (T) exposure. We aimed to explore interrelations of prenatal phenol exposures individually and in mixtures, cord serum reproductive hormones, and 2D: 4D ratio of children aged 10 years. Urinary 11 phenol concentrations were determined from 392 pregnant women participating in a longitudinal birth cohort. We estimated associations of prenatal phenol exposures individually and in mixtures with cord reproductive hormones and children's 2D:4D ratio using three statistical approaches, including generalized linear models (GLMs), elastic net regression (ENR) models and Bayesian kernel machine regression (BKMR) models. In female newborns, the three models showed that maternal triclosan (TCS) concentrations were significantly negatively associated with cord serum T levels [regression coefficient (β) = -0.076, 95% confidence interval (CI): 0.138, -0.013; p = 0.018]. Additionally, maternal urinary bisphenol A (BPA) levels were related to decreases in 2D:4D ratio of the left hand in girls by GLMs (β = -0.003, 95% CI: 0.007, -0.001; p = 0.024) and ENR models, but not BKMR models. We provided evidence that prenatal TCS exposure predicted lower cord serum T levels, and maternal BPA exposure was related to decreased 2D:4D ratio of the left hand in females.
|
|
| 13. |
- Hu, Jianfeng, et al.
(författare)
-
A general mechanism of grain growth -I. Theory
- 2021
-
Ingår i: Journal of Materiomics. - : Elsevier BV. - 2352-8478 .- 2352-8486. ; 7:5, s. 1007-1013
-
Tidskriftsartikel (refereegranskat)abstract
- The behaviors of grain growth dominate the formation of the microstructure inside polycrystalline materials and thus strongly influence their practical performances. However, grain growth behaviors still remain ambiguous and thus lack a mathematical formula to describe the general evolution despite decades of efforts. Here, we propose a new migration model of grain boundary (GB) and further derive a mathematical expression to depict the general evolution of grain growth in the cellular structures. The expression incorporates the variables influencing growth rate (e.g. GB features, grain size and local grain size distribution) and thus reveals how the normal, abnormal and stagnant behaviors of grain growth occur in polycrystalline systems. In addition, our model correlates quantitatively GB roughening transition with grain growth behavior. The general growth theory may provide new insights into the GB thermodynamics and kinetics during the cellular structure evolution.
|
|
| 14. |
- Li, Jiantong, et al.
(författare)
-
Contact-electrode insensitive rectifiers based on carbon nanotube network transistors
- 2008
-
Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 29:5, s. 500-502
-
Tidskriftsartikel (refereegranskat)abstract
- This letter presents rectifiers based on the diode connection of carbon nanotube network (CNN) transistors. Despite a low density of carbon nanotubes in the CNNs, the devices can achieve excellent performance with a forward/reverse current ratio reaching 10(5). By casting nanotube suspension on oxidized Si substrates with predefined electrodes, CNN-based field-effect transistors are readily prepared. By short-circuiting the source and gate terminals, CNN-based rectifiers are realized with the rectification characteristics independent of whether Pd or Al is employed as the contact electrodes. This independence is especially attractive for applications of CNN-based transistors/rectifiers in flexible electronics with various printing techniques.
|
|
| 15. |
|
|
| 16. |
- Liu, Zhiying, et al.
(författare)
-
Hysteresis-free thin-film transistors achieved by novel solution-processing of nanotubes/polymer composites
- 2012
-
Ingår i: Materials Research Society Spring Meeting 2012, San Francisco, April 9-13, 2012..
-
Konferensbidrag (refereegranskat)abstract
- Thin-film transistors (TFTs) based on single-walled carbon nanotubes (SWCNTs) have gained enormous attention in the community of flexible/stretchable electronics. At present, such TFTs often suffer from severe problems including giant hysteresis in their transfer characteristics. With SiO2 as the gate dielectric, extensive investigations have led to generally accepted understanding of the hysteresis as being caused by charge transfer between the SWCNTs and their surroundings including both water molecules bound on the SiO2 surface (Si≡OH) and the water/oxygen molecules in the ambient atmosphere. In order to combat the hysteresis issue, significant efforts have been made by annealing the TFTs in vacuum and separating SWCNTs from SiO2 by deposition of a self-assembled monolayer (SAM) on the SiO2 or passivating the SWCNTs with an organic or inorganic dielectric film. These methods, however, require either processing in inert environment or developing elaborated processes. In the present work, we demonstrate hysteresis-free TFTs based on SWCNT/polymer composite without any complex treatment. The composite consists of SWCNTs and poly-9,9_dioctyl-fluorene-co-bithiophene (F8T2). With the aid of polymer F8T2, SWCNTs can be efficiently dissolved in commonly used solvents thereby forming a uniform composite solution. By soaking a chip with predefined TFT structures on an oxidized Si substrate in the composite solution, direct assembly of the composite on the SiO2 occurs, leading to the formation of a composite thin film in the channel region of the TFTs. Although fabricated using a very simple process, our TFTs exhibit hysteresis-free operation under ambient conditions. It is plausible to suggest that SWCNTs are embedded in the F8T2 matrix with the latter providing an effective shield for the former against the trap sites on the SiO2 and the H2O/O2 molecules in the atmosphere. In comparison to the other reported means aiming at hysteresis reduction, the present method is simple, robust, solution processable, effective, and operable under ambient conditions. In addition, we have found F8T2 to preferentially disperse semiconducting SWCNTs rendering a selective removal of the metallic species in the solution. This selectivity is of paramount importance as it results in high-performance TFTs with both high on-state current (0.1 µA/µm @ channel length = 50 µm) and large on/off current ratio (103-105). The TFTs have also shown significantly improved uniformity and dimensional scalability with a mobility value of 10-20 cm2V-1s-1, which have allowed us to investigate the TFTs using the resultant logic circuits.
|
|
| 17. |
- Liu, Zhiying, et al.
(författare)
-
Mobility Extraction for Nanotube TFTs
- 2011
-
Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 32:7, s. 913-915
-
Tidskriftsartikel (refereegranskat)abstract
- An extensive investigation of carrier mobility is presented for thin-film transistors (TFTs) with single-walled carbon nanotube (SWCNT) networks as the semiconductor channel. For TFTs particularly with low-density SWCNTs in the networks, the extracted mobility using the standard method for Si metal-oxide-semiconductor field-effect transistors is erroneous, mainly resulting from use of a parallel-plate capacitor model and assumption of the source-drain current being inversely proportional to the channel length. Large hysteresis in the transfer characteristics further complicates the extraction. By properly addressing all these challenges in this letter, a comprehensive methodology is established, leading to the extraction of mobility values that are independent of geometrical parameters.
|
|
| 18. |
- Liu, Zhiying, et al.
(författare)
-
SMALL-Hysteresis Thin-Film Transistors Achieved by Facile Dip-Coating of Nanotube/Polymer Composite
- 2012
-
Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 24:27, s. 3633-3638
-
Tidskriftsartikel (refereegranskat)abstract
- Small-hysteresis, high-performance thin-film transistors (TFTs) are readily realized simply by dip-coating of a solution-processable composite. The composite consists of single-walled carbon nanotubes (SWCNTs) embedded in semiconducting polymer used as the channel material. The resultant TFTs simultaneously exhibit large on/off current ratio, high on-current level, high mobility in the range 10−20 cm2V−1s−1, and good uniformity and scalability.
|
|
| 19. |
- Liu, Zhiying, 1982-, et al.
(författare)
-
Solution-Processed Logic Gates Based On Nanotube/Polymer Composite
- 2013
-
Ingår i: IEEE Transactions on Electron Devices. - 0018-9383 .- 1557-9646. ; 60:8, s. 2542-2547
-
Tidskriftsartikel (refereegranskat)abstract
- Hysteresis-free logic gates capable of operation at 100 kHz are fabricated basing on local-gate thin-film transistors with their channel featuring solution-processed composite films of single-walled carbon nanotubes (SWCNTs) and poly(9,9-dioctylfluorene-co-bithiophene) (F8T2). Using dip-coating for deposition of composite films, high-density SWCNTs are found to be embedded in an F8T2 layer and thus being kept from the underlying AlOx gate dielectric by a certain distance. The presence of the F8T2 interlayer effectively suppresses hysteresis although it also weakens the gate electrostatic control. The fabricated transistors are characterized by nil hysteresis, high carrier mobility, large ON/OFF current ratio, low operation voltage, small subthreshold swing, and remarkable scalability. These properties are crucial for the realization of the well-performing logic circuits.
|
|
| 20. |
- Luo, Jun, et al.
(författare)
-
Surface-energy triggered phase formation and epitaxy in nanometer-thick Ni1-xPtx silicide films
- 2010
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 96:3
-
Tidskriftsartikel (refereegranskat)abstract
- The formation of ultrathin silicide films of Ni1-xPtx at 450-850 degrees C is reported. Without Pt (x=0) and for t(Ni)< 4 nm, epitaxially aligned NiSi2-y films readily grow and exhibit extraordinary morphological stability up to 800 degrees C. For t(Ni)>= 4 nm, polycrystalline NiSi films form and agglomerate at lower temperatures for thinner films. Without Ni (x=1) and for t(Pt)=1-20 nm, the annealing behavior of the resulting PtSi films follows that for the NiSi films. The results for Ni1-xPtx of other compositions support the above observations. Surface energy is discussed as the cause responsible for the distinct behavior in phase formation and morphological stability.
|
|
| 21. |
- Luo, Ziteng, et al.
(författare)
-
Roots-Enhanced Preferential Flows in Deciduous and Coniferous Forest Soils Revealed by Dual-Tracer Experiments
- 2019
-
Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425. ; 48:1, s. 136-146
-
Tidskriftsartikel (refereegranskat)abstract
- Macropores formed by roots are crucial channels for preferential flows in forest soils that are largely responsible for water percolation and solute leaching. Using dual-tracer experiments (Brilliant Blue FCF and bromide [Br]), this study investigated the preferential flows of water and solutes in a deciduous forest dominated by Bl. and a coniferous forest mainly planted with (L.) Franco. Dye-stained patterns and concentrations of Brilliant Blue and Br were obtained in vertical soil profiles (0-30 cm), whereas stained and unstained roots were collected and analyzed in horizontal soil profiles to a 30-cm soil depth. Brilliant Blue and Br were mainly accumulated in the 0- to 20-cm soil depth, which had greater total root length density than the 20- to 30-cm soil depth ( < 0.05). Only part of the roots facilitated the preferential flows, with finer roots (i.e., diameter <1 mm) contributing the most. More intriguingly, the coniferous forest soil had a greater degree of preferential flows and greater tracer concentrations at deeper soil depth than the deciduous forest soil, suggesting the importance of tree species and forest composition on water and solute transport in forest ecosystems.
|
|
| 22. |
- Makafe, Gaelle G., et al.
(författare)
-
Quinoline Derivatives Kill Mycobacterium tuberculosis by Activating Glutamate Kinase
- 2019
-
Ingår i: Cell Chemical Biology. - : CELL PRESS. - 2451-9456 .- 2451-9448. ; 26:8, s. 1187-
-
Tidskriftsartikel (refereegranskat)abstract
- There is a great need for identification and development of new anti-tuberculosis drugs with novel targets. Recent drug-discovery efforts typically focus on identifying inhibitors but not activators that perturb metabolic enzymes' functions as a means to kill Mycobacterium tuberculosis (Mtb). Here, we describe a class of quinoline compounds, Z0933/Z0930, which kill Mtb by acting as activators of glutamate kinase (GK), a previously untargeted enzyme catalyzing the first step of proline biosynthesis. We further show that Z0933/Z0930 augment proline production and induce Mtb killing via proline-derived redox imbalance and production of reactive oxygen species. This work highlights the effectiveness of gain-of-function probes against Mtb and provides a framework for the discovery of next-generation allosteric activators of GK.
|
|
| 23. |
- Qiu, Zhijun, et al.
(författare)
-
A comparative study of two different schemes to dopant segregation at NiSi/Si and PtSi/Si interfaces for Schottky barrier height lowering
- 2008
-
Ingår i: IEEE Transactions on Electron Devices. - 0018-9383 .- 1557-9646. ; 55:1, s. 396-403
-
Tidskriftsartikel (refereegranskat)abstract
- An experimental study is presented to compare two different schemes used to incorporate a high concentration of dopants at the silicide/silicon interface for NiSi and PtSi, i.e., dopant segregation, with the purpose of lowering the Schottky barrier height (SBH) of the contact systems. Specifically, the interfacial dopant is introduced either through silicidation-induced dopant segregation (SIDS) or by silicide as diffusion source (SADS). For the latter, a postimplantation drive-in anneal is needed. For both silicide systems, the dopant segregation gives rise to a predominant effect, leading to an effective SBH that is independent of the original SBHs of PtSi and NiSi, which differs by 0.2 eV. Scheme SUDS is relatively simple in processing, but the silicidation process is dopant-dependent, leading to local variations of silicide formation. Scheme SADS addresses the adverse effect of dopant on silicidation by separating silicidation from dopant incorporation.
|
|
| 24. |
- Qiu, Zhijun, et al.
(författare)
-
Role of Si implantation in control of underlap length in Schottky-barrier source/drain MOSFETs on ultrathin body SOI
- 2008
-
Ingår i: Proceedings of ULIS. - NEW YORK : IEEE. ; , s. 175-178, s. 175-178
-
Konferensbidrag (refereegranskat)abstract
- This works demonstrates a novel approach using Si implantation prior to Pt deposition and PtSi formation to control the underlap length between the PtSi source/drain regions to the gate in Schottky-Barrier (SB-) MOSFETs. Dopant segregation at the PtSi/Si interface is used to enhance device performance. With the lon /Ioff current ratio as an indicator, optimized Si implant doses are found for both n- and p-channel SB-MOSFETs. Through an effective barrier width, the underlap length has direct implication on the leakage current.
|
|
| 25. |
- Qiu, Zhijun, et al.
(författare)
-
Silicide as diffusion source for dopant segregation in 70-nm MOSFETs with PtSi Schottky-barrier source/drain on ultrathin-body SOI
- 2008
-
Ingår i: ULIS 2008. - NEW YORK : IEEE. ; , s. 23-26
-
Konferensbidrag (refereegranskat)abstract
- In this paper, dopant segregation (DS) method is adopted to enhance device performance of PtSi-based Schottky-barrier source/drain MOSFETs (SB-MOSFETs) fabricated on ultrathin silicon-on-insulator. The DS formation is realized by means of Silicide As Diffusion Source. Without DS treatment, the devices are typically p-type, but with a rather large electron branch at positive gate bias. Dopant segregation with As is found to turn the devices to well-performing n-MOSFETs, and DS with B to greatly enhance the hole conduction in the p-MOSFETs. A large threshold voltage (V-t) shift is however observed in the p-MOSFET due to B lateral spread caused during the drive-in process for the DS formation. By reducing the drive-in temperature, this problem is partially addressed with a smaller V-t shift and a much better control of short channel effect.
|
|
| 26. |
- Zhang, Jiming, et al.
(författare)
-
Carbamate pesticides exposure and delayed physical development at the age of seven : Evidence from the SMBCS study
- 2022
-
Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 160
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Carbamate pesticides are widely used in agriculture and cause widespread human exposure. The health effect of carbamates on physical development remains unclear. The current study aimed to explore the carbamate's health effect on physical development.METHODS: Prenatal, 3-year-old, 7-year-old urinary carbofuranphenol concentration was measured by gas chromatography tandem mass spectrometry and adjusted by creatinine. Anthropometric indices were measured by standard method and z-score standardized. Generalized linear models (GLM) were using to assess associations between exposure measurements and anthropometric indices. The generalized estimate equation (GEE) was applied to analyze the association between multiperiod exposure and anthropometric indices, and time-interaction terms were used to exam health effect consistency of exposure in each period. Gender-stratified analysis were conducted according to results of gender-interaction terms to identify gender-specific effects.RESULTS: The gender-interaction term of prenatal exposure with height z-score was significant (β = -0.057; 95% CI: -0.113, -0.001; p = 0.045). The 3-year-old carbofuranphenol level showed negative associations with weight z-score (β = -0.019; 95% CI: -0.038, -0.000; p = 0.040), height z-score (β = -0.015; 95% CI: -0.028, -0.001; p = 0.026), chest circumference (β = -0.086; 95% CI: -0.171, -0.001; p = 0.046), and waist circumference (β = -0.128; 95% CI: -0.230, -0.026; p = 0.014). No statistically significant trend was found for prenatal and 7-year-old carbofuranphenol levels. In GEEs, carbofuranphenol level was negatively associated with weight z-score (β = -0.103; 95% CI: -0.195, -0.011; p = 0.027), height z-score (β = -0.087; 95% CI: -0.152, -0.022; p = 0.008), and chest circumference (β = -0.472; 95% CI: -0.918, -0.026; p = 0.037). Boy's height z-score was inversely associated with carbamate exposure (β = -0.140; 95% CI: -0.227, -0.053; p = 0.001).CONCLUSIONS: Prenatal and postnatal carbamate exposure may affect physical developmental process.
|
|
| 27. |
- Zhang, Jiming, et al.
(författare)
-
Early-life carbamate exposure and intelligence quotient of seven-year-old children
- 2020
-
Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 145
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Early-life carbamate exposure during developmental period has been linked with adverse health effects and attracted attention.Methods: Three hundred and three children at age of seven were included in the current study. Urinary carbofuranphenol concentrations were measured using gas chromatography-tandem mass spectrometry. Verbal, performance and full-scale intelligence quotients (IQ(V), IQ(P), and IQ(FS)) were assessed using Wechsler Intelligence Scale for Children-Chinese Revised. Generalized linear models were used to explore the associations between carbofuranphenol levels and IQs. Generalized estimating equations were used to explore long-term health effect and sensitive time window.Results: Carbofuranphenol was detected in 96.6% of the seven-year-old urinary samples, the geometric mean, median, and inter quartile range of the carbofuranphenol concentrations were 0.67 mu g/L, 0.30 mu g/L, and 0.09-3.72 mu g/L, respectively, which were similar with the level of three-year-old children from the SMBCS cohort. Seven-year-old carbofuranphenol level was negatively associated with IQP [beta = -0.044; 95% confidence interval (CI): -0.087, -0.001; p = 0.045]. Three-year-old carbofuranphenol level was negatively associated with IQP (beta =-0.100; 95% CI: -0.186, -0.014; p= 0.022) and IQFS (beta =-0.087; 95% CI: -0.173, -0.001; p = 0.047). Carbamate exposure of maternal and children at both three and seven years old had negative associations with IQP (beta = -0.089; 95% CI: -0.171, -0.007; p = 0.034), and IQFS (beta = -0.064; 95% CI: -0.127, -0.000; p = 0.049) of children at age of seven.Conclusion: Results of the present study verify that children in an agricultural region of China were widely exposed to carbamate pesticides. Carbamate exposure in utero and at three and seven years may adversely impact children's neurodevelopment.
|
|
| 28. |
- Zhang, Jiming, et al.
(författare)
-
Exposure to carbamate and neurodevelopment in children : Evidence from the SMBCS cohort in China
- 2019
-
Ingår i: Environmental Research. - : Academic Press. - 0013-9351 .- 1096-0953. ; 177
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Carbamate pesticides exposure have been linked with adverse health effects during developmental period. Based on 377 mother-child pairs from Sheyang Mini Birth Cohort Study, the present study aimed to assess carbofuranphenol exposure of three-year-old children and explore the associations between prenatal or postnatal carbofuranphenol exposures and neurodevelopmental indicators.METHODS: Urinary carbofuranphenol concentrations were measured by gas chromatography-tandem mass spectrometry. Neural developmental quotient (DQ) of children was evaluated using Gesell Developmental Schedules. Generalized linear models were used to examine the associations between carbofuranphenol concentrations and neurodevelopment.RESULTS: Geometric mean, geometric standard deviation, median, inter quartile range of postnatal urinary carbofuranphenol concentrations were 0.653 μg/L, 9.345 μg/L, 0.413 μg/L, 0.150-1.675 μg/L, respectively. Postnatal carbofuranphenol level showed negatively significant trend in language DQ [beta (β) = -0.121; 95% confidence interval (95% CI): 0.212, -0.031; p value (p) = 0.008] and total average DQ (β = -0.059, 95% CI: 0.115, -0.003; p = 0.035). Prenatal carbofuranphenol level showed negative correlations with children's adaptive DQ (β = -0.755; 95% CI: 1.257, -0.254; p = 0.003), social DQ (β = -0.341; 95% CI: 0.656, -0.027; p = 0.032) and total average DQ (β = -0.349; 95% CI: 0.693, -0.005; p = 0.047).CONCLUSION: The results of the present study supposed children in agricultural region of China are widely exposed to carbamate pesticides, and both prenatal and postnatal exposure to carbamate pesticides may lead to neurodevelopmental effect.
|
|
| 29. |
- Zhang, Jiming, et al.
(författare)
-
Maternal urinary carbofuranphenol levels before delivery and birth outcomes in Sheyang Birth Cohort
- 2018
-
Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 625, s. 1667-1672
-
Tidskriftsartikel (refereegranskat)abstract
- Exposure to carbamates has been linked with adverse health effects on developmental period. This study aimed to monitor exposure to carbofuranphenol of pregnant women from Sheyang Birth Cohort and investigate associations between prenatal exposure to carbofuranphenol and birth outcomes. During June 2009 to January 2010, 1100 pregnant women living in Sheyang County participated in our study and donated urine sample. Urinary carbofuranphenol concentration was measured by gas chromatography-tandem mass spectrometry. Associations between urinary carbofuranphenol levels and infant birth outcomes were assessed by generalized linear models. Urinary carbofuranphenol concentrations varied from 0.01 to 395.40μg/L (0.01-303.93μg/g for creatinine adjusted), the geometric mean, median and inter quartile range are 0.81μg/L (1.28μg/g cr), 0.80μg/L (1.23μg/g cr) and 0.27-2.20μg/L (0.47-3.11μg/g cr), respectively. No statistically significant association between maternal urinary carbofuranphenol levels and birth outcomes was found in total infants and female infants. In male neonates, carbofuranphenol level was significantly associated with head circumference (b=-0.226; 95% confidence interval: -0.411, -0.041; P=0.01) and ponderal index (b=0.043, 95% CI: 0.004, 0.083; P=0.03). These findings suggested that the pregnant women were generally exposed to carbofuranphenol and prenatal exposure to carbofuranphenol might have adverse effects on fetal development.
|
|
| 30. |
- Zhang, Jiming, et al.
(författare)
-
Multiple mediation effects on association between prenatal triclosan exposure and birth outcomes
- 2022
-
Ingår i: Environmental Research. - : Elsevier. - 0013-9351 .- 1096-0953. ; 215:Part 1
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Triclosan is a broad-spectrum antimicrobial, and was thought to affect intrauterine development, but the mechanism remains unclear.OBJECTIVE: To explore the association between prenatal triclosan exposure and birth outcomes.METHODS: Based on 726 mother-child pairs from the Sheyang Mini Birth Cohort Study (SMBCS), we used the available (published) data of triclosan in maternal urines, the hormones including thyroid-related hormones, gonadal hormones in cord blood, and adipokines, trimethylamine-N-oxide (TMAO) and its precursors in cord blood to explore possible health effects of triclosan on birth outcomes through assessing different hormones and parameters, using Bayesian mediation analysis.RESULTS: Maternal triclosan exposure was associated with ponderal index (β = 0.317) and head circumference (β = -0.172) in generalized linear models. In Bayesian mediation analysis of PI model, estradiol (β = 0.806) and trimethylamine (TMA, β = 0.164) showed positive mediation effects, while total thyroxine (TT4, β = -0.302), leptin (β = -2.023) and TMAO (β = -0.110) showed negative mediation effects. As for model of head circumference, positive mediation effects were observed in free thyroxine (FT4, β = 0.493), TMA (β = 0.178), and TMAO (β = 0.683), negative mediation effects were observed in TT4 (β = -0.231), testosterone (β = -0.331), estradiol (β = -1.153), leptin (β = -2.361), choline (β = -0.169), betaine (β = -0.104), acetyl-L-carnitine (β = -0.773).CONCLUSION: The results indicated triclosan can affect intrauterine growth by interfering thyroid-related hormones, gonadal hormones, adipokines, TMAO and its precursors.
|
|
| 31. |
- Zhang, Lei, et al.
(författare)
-
Prenatal exposure to parabens in association with cord serum adipokine levels and offspring size at birth
- 2022
-
Ingår i: Chemosphere. - : Pergamon Press. - 0045-6535 .- 1879-1298. ; 301
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Paraben exposure is linked to the release of adipokine such as leptin and adiponectin, and both paraben and adipokine may affect fetal growth. The present study aimed to explore the associations among maternal paraben exposure, adipokine level and offspring size.METHODS: 942 mother-newborn pairs from the Sheyang Mini Birth Cohort Study (SMBCS) were enrolled. Data of birth weight, length, head circumference and ponderal index (PI) were obtained from medical records. Maternal urinary parabens were determined by gas chromatography tandem mass spectrometry. Cord serum leptin and adiponectin were measured using ELISA assay. Generalized linear regression was applied to explore the associations among parabens, adipokines and offspring size.RESULTS: The median levels of leptin and adiponectin were 13.13 μg/L and 161.82 μg/mL. Benzylparaben level was positively associated with leptin (regression coefficient (β) = 0.06, 95% confidence interval (CI): 0.03-0.09; p < 0.01). Leptin level was positively associated with neonatal weight (β = 84.11, 95% CI: 63.22-105.01; p < 0.01), length (β = 0.25, 95% CI: 0.14-0.37; p < 0.01), head circumference (β = 0.15, 95% CI: 0.07-0.22; p < 0.01) and PI (β = 0.23, 95% CI: 0.08-0.39; p < 0.01). Adiponectin was positively associated with neonatal weight (β = 75.94, 95% CI: 29.65-122.23; p < 0.01) and PI (β = 0.43, 95% CI: 0.09-0.77; p = 0.01). Urinary propylparaben concentration (β = -0.10, 95% CI: 0.17 to -0.02; p = 0.01) was negatively associated with head circumference. Sex-stratified analyses indicated the negative association of propylparaben and head circumference was only remained in male neonates.CONCLUSIONS: Prenatal paraben exposure might affect cord serum leptin levels. Both paraben and adipokine levels may affect fetal growth, and sex-specific differences may exist.
|
|
| 32. |
- Zhang, Zhen, et al.
(författare)
-
Performance fluctuation of FinFETs with Schottky barrier source/drain
- 2008
-
Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 29:5, s. 506-508
-
Tidskriftsartikel (refereegranskat)abstract
- A considerable performance fluctuation of FinFETs featuring PtSi-based Schottky barrier source/drain is found. The Fin-channels measure 27-nm tall and 35-nm wide. Investigation of similarly processed transistors of broad gate-widths reveals a large variation in the position of the PtSi/Si interface with reference to the gate edge along the gate width. This variation suggests an uneven underlap between the PtSi and the gate from device to device for the FinFETs, since essentially only one silicide grain would be in contact with each Fin-channel at the PtSi/Si interface. The size of the underlap is expected to sensitively affect the performance of the FinFETs.
|
|
| 33. |
- Zhang, Zhen, et al.
(författare)
-
SB-MOSFETs in UTB-SOI featuring PtSi source/drain with dopant segregation
- 2008
-
Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 29:1, s. 125-127
-
Tidskriftsartikel (refereegranskat)abstract
- MOSFETs of both polarities with PtSi-based Schottky-barrier source/drain (S/D) have been fabricated in ultrathin-body Si-on-insulator. The PtSi is formed in the S/D regions without lateral silicide growth under the gate spacers. This design leads to a 30-nm underlap between the PtSi-Si contacts and the gate edges resulting in low drive currents. Despite the underlap, excellent performance is achieved for both types of MOSFETs with large drive currents and low leakage by means of dopant segregation through As and B implantation into the PtSi followed by drive-in annealing at low temperatures.
|
|
| 34. |
- Zhang, Zhen, et al.
(författare)
-
Schottky-barrier height tuning by means of ion implantation into preformed silicide films followed by drive-in anneal
- 2007
-
Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 28:7, s. 565-568
-
Tidskriftsartikel (refereegranskat)abstract
- An experimental study on Schottky-barrier height (SBH) tuning using ion implantation followed by drive-in anneal of As, B, In, and P in preformed NiSi and PtSi films is presented. Measured on B-implanted NiSi and PtSi Schottky diodes, the effective SBH on n-type Si is altered to similar to 1.0 eV. For As- and P-implanted diodes, the SBH on p-type Si can be tuned to around 0.9 eV The process window for the most pronounced SBH modification is dopant dependent.
|
|
| 35. |
- Zhong, Shenghui, et al.
(författare)
-
Assessment of grid/filter size dependence in large eddy simulation of high-pressure spray flames
- 2022
-
Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 329
-
Tidskriftsartikel (refereegranskat)abstract
- With the increase of computing power, large eddy simulation (LES) within the Lagrangian–Eulerian two-phase flow framework has evolved as an useful numerical tool to gain insights to the spray combustion processes in advanced internal combustion engines. However, the inherent effect of grid/filter size (G/FS) on the physics revealed by LES is not fully understood. In this paper, we present several new viewpoints on this by analyzing the results from a Lagrangian–Eulerian LES study of Engine Combustion Networks Spray A with a newly developed multi-region adaptive mesh refinement method in OpenFOAM. It is found that G/FS affects the predicted spray characteristics, the modes of spray combustion, the ignition delay time and the liftoff length in different ways. First, owing to the nature of Lagrangian particle-in-cell approach, the spray liquid penetration length converges as the G/FS approaches to the nozzle diameter. The convergence behavior is rather independent of the spray model parameters. Second, it is critical to have a well resolved spray liquid region; the main spray combustion characteristics, e.g., the mean pressure rise profile, the onsets of the cool flame and hot flame, and the main flame structure, are shown to be similar and independent of G/FS once the liquid region is properly resolved. However, the detailed flame structures at the liftoff position are sensitive to G/FS; the upstream auto-ignition events, the low temperature ignition assisted flame propagation and the hot flame propagation, are shown to partially rely on the adopted G/FS. Finally, it is found that a finer G/FS predicts a slower fuel/oxidizer mixing and a shorter flame liftoff length, yielding a higher soot mass.
|
|
| 36. |
|
|
| 37. |
- Baryshnikov, G. V., et al.
(författare)
-
Structure and Spectral Properties of Truxene Dye S5
- 2012
-
Ingår i: Optics and Spectroscopy. - 0030-400X .- 1562-6911. ; 112:2, s. 168-174
-
Tidskriftsartikel (refereegranskat)abstract
- On the ground of functional theory with the B3LYP and BMK functionals, we have studied the structure and optical properties of a truxene dye sensitizer S5 for photoelectric transducers. Based on the calculations of the vertical excitations energy of the dye molecule and accounting the influence of the solvent, we have revealed a positive solvatochromic effect that is weak compared to results obtained in the vacuum approximation. We have studied new features describing stabilization of the planar structure of the cyanothiophene-acrylic fragment of the S5 dye.
|
|
| 38. |
|
|
| 39. |
- Du, Jie, et al.
(författare)
-
Effects of rainfall intensity and slope on interception and precipitation partitioning by forest litter layer
- 2019
-
Ingår i: Catena. - : Elsevier BV. - 0341-8162. ; 172, s. 711-718
-
Tidskriftsartikel (refereegranskat)abstract
- Rainfall interception and other hydrologic processes affected by the forest litter layer are usually related to litter characteristics and rainfall conditions, with limited studies that consider the influence of slope. To simulate the hydrological functions of the litter layer at different slope gradients, artificial rainfall experiments were conducted at four rainfall intensities (from 30 to 120 mm hr−1) in horizontal and inclined trays (with the slope of 0° 10° 20° and 30°) with litter of Pinus tabuliformis or Quercus variabilis. The results indicated that (1) the dynamic process of litter interception had 3 phases: a rapid intercepted phase within the first 5 min, a moderate intercepted phase and a post-rainfall drainage phase; (2) the maximum interception storage (Cmax) and the minimum interception storage (Cmin) of Q. variabilis were larger than those of P. tabuliformis; (3) Cmax and Cmin were correlated with slope for both types of litter, whereas only Cmax was correlated with rainfall intensity; and (4) lateral flow amount significantly increased with both slope gradient and rainfall intensity only for Quercus variabilis, whereas drainage volume showed significant correlation with rainfall intensity. Moreover, the ratio of lateral runoff and drainage was affected by slope gradient whereas percentage of litter interception had a good relationship with rainfall intensity, rather than slope, with litter interception and drainage contributing the smallest and the largest proportions, respectively. Overall, the results demonstrate the effect of rainfall and slope factors on hydrological processes in the forest litter layer.
|
|
| 40. |
- Gao, Lihua, et al.
(författare)
-
Interfacial phenomenon and Marangoni convection of Fe–C melt on coke substrate under in situ observation
- 2023
-
Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- The interfacial phenomenon between liqiuid iron and coke is important for determining the melting efficiency in the blast furnace iron-making process. In this study, the interaction observed in the case of the iron-carbon (Fe–C) melt on coke substrate was investigated using a high-temperature vacuum wettability test equipment. The Fe–C melt did not wet and spread on the coke substrate with different graphitization degrees (r 0) at a high temperature of 1450 °C. The contact angles changed from 124.5° to 105.3°, and the r 0 increased from 9.30 to 50.00%, thus indicating a nonwetting state. The deepening of graphitization decreased the contact angle. Thereby, increasing the contact area between liquid iron and the carbonaceous material, which facilitated carbon dissolution. The irregular movements of Fe–C melt were observed in situ during the wetting process. The horizontal force of the droplet caused by interfacial tension and the contact angle; the Marangoni convection owing to the gradient of carbon concentration; and the impulse force caused by the generation, aggregation, and release of SiO bubbles at the interface were attributed to the driving force.
|
|
| 41. |
- Luo, Jun, et al.
(författare)
-
On Different Process Schemes for MOSFETs With a Controllable NiSi-Based Metallic Source/Drain
- 2011
-
Ingår i: IEEE Transactions on Electron Devices. - : IEEE Institute of Electrical and Electronics. - 0018-9383 .- 1557-9646. ; 58:7, s. 1898-1906
-
Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on different silicidation schemes toward a controllable NiSi-based metallic source/drain (MSD) process with restricted lateral encroachment of NiSi. These schemes include thickness control of Ni, Ni-Pt alloying, and two-step annealing. Experimental results show that all the three process schemes can give rise to effective control of lateral encroachment during Ni silicidation. By controlling t(Ni), NiSi-based MSD metal-oxide-semiconductor field-effect transistors (MOSFETs) of gate length L-G = 55 nm are readily realized on ultrathin-body silicon-on-insulator substrates with 20-nm surface Si thickness. With the aid of dopant segregation (DS) to modifying the Schottky barrier heights of NiSi, both n- and p-type MSD MOSFETs show significant performance improvement, compared to reference devices without DS.
|
|
| 42. |
|
|
| 43. |
- Ning, Zhijun, et al.
(författare)
-
Novel iridium complex with carboxyl pyridyl ligand for dye-sensitized solar cells : High fluorescence intensity, high electron injection efficiency?
- 2009
-
Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 694:17, s. 2705-2711
-
Tidskriftsartikel (refereegranskat)abstract
- Novel iridium-based sensitizers Iridium(III) bis[2-phenylpyridinato-N,C-2']-5-carboxylpicolinate) (Ir1), Iridium(III) bis[2-(naphthalen-1-yl) pyridinato-N,C-2']-5-carboxyl-picolinate) (Ir2), Iridium(III) bis[2-phenylpyridinato-N, C-2']-4,4'-(dicarboxylicacid)-2,2'-bipyridine (Ir3) were synthesized for sensitization of mesoscopic titanium dioxide injection solar cells. By changing the ligand, the absorption spectra can be extended and molar extinction coefficient was enhanced. The dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) based on dye Ir3 showed the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 85%, a short-circuit photocurrent density (J(sc)) of 9.59 mA cm (2), an open-circuit photovoltage (V-oc) of 0.552 V, and a fill factor (ff) of 0.54, corresponding to an overall conversion efficiency of 2.86% under AM 1.5 sun light. Moreover, the HOMO and LUMO energy levels tuning can be conveniently accomplished by alternating the ligand. The high oxidative potential of Ir3 enables it to be used along with Br-/Br-3(-) redox electrolyte and the photovoltage was found to be enhanced greatly.
|
|
| 44. |
- Ning, Zhijun, et al.
(författare)
-
Photovoltage Improvement for Dye-Sensitized Solar Cells via Cone-Shaped Structural Design
- 2009
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 113:23, s. 10307-10313
-
Tidskriftsartikel (refereegranskat)abstract
- In this article, three truexene-based dyes with 2-cyanoacrylic acid as acceptor and starburst triarylamine as donor (S5, S6, and S7) were conveniently synthesized and used for dye-sensitized solar cells (DSSCs). A compact sensitizer layer is molecular interfacially engineered on the TiO2 surface via cone-shaped sensitizers. As a result, the approach of the electrolyte to the TiO2 surface is blocked significantly by the compact sensitizer layer formed and the charge recombination in the DSSCs is proved to be retarded effectively. The monochromatic incident photon-to-current conversion efficiency of these sensitizers is near 90%. In addition, S7-sensitized solar cells yield an open-circuit voltage of 752 mV and it fill factor of 0.70, which are even higher than those of N719 under the same conditions.
|
|
| 45. |
- Ning, Zhijun, et al.
(författare)
-
Starburst triarylamine based dyes for efficient dye-sensitized solar cells
- 2008
-
Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 73:10, s. 3791-3797
-
Tidskriftsartikel (refereegranskat)abstract
- We report here on the synthesis and photophysical/electrochemical properties of a series of novel starburst triarylamine-based organic dyes (S1, S2, S3, and S4) as well as their application in dye-sensitized nanocrystalline TiO2 solar cells (DSSCs). For the four designed dyes, the starburst triarylamine group and the cyanoacetic acid take the role of electron donor and electron acceptor, respectively. It was found that the introduction of starburst triarylamine group to form the D-D-pi-A configuration brought about superior performance over the simple D-pi-A configuration, in terms of bathochromically extended absorption spectra, enhanced molar extinction coefficients and better thermo-stability. Moreover, the HOMO and LUMO energy levels tuning can be conveniently accomplished by alternating the donor moiety, which was confirmed by electrochemical measurements and theoretical calculations. The DSSCs based on the dye S4 showed the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 85%, a short-circuit photocurrent density (J(sc)) of 13.8 mA cm(-2), an open-circuit photovoltage (V-oc) of 0.63 V, and a fill factor (ff) of 0.69, corresponding to an overall conversion efficiency of 6.02% under 100 mW cm(-)2 irradiation. This work suggests that the dyes based on starburst triphenylamine donor are promising candidates for improvement of the performance of the DSSCs.
|
|
| 46. |
- Ning, Zhijun, et al.
(författare)
-
Wave-Function Engineering of CdSe/CdS Core/Shell Quantum Dots for Enhanced Electron Transfer to a TiO2 Substrate.
- 2010
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:35, s. 15184-15189
-
Tidskriftsartikel (refereegranskat)abstract
- The authors synthesized core/shell quantum dots (QDs) for the purpose of enhancing the electron transfer from the dots to a TiO2 substrate. The authors make use of the fact that CdSe is a small-bandgap material compared with CdS; therefore, in a common CdSe/CdS core/shell QD, the photoexcited electron is confined deeply in the CdSe core. By special construction of the CdS/CdSe core/shell QDs, referred as reversed type-I, the electron wave function will distribute largely in the shell region. This facilitates the transfer of the electron from the QD to the TiO2 substrate, resulting in significantly improved electron-injection efficiency. Such an enhanced electron-injection efficiency was confirmed by fluorescence lifetime decay measurements, showing the largest lifetime redn. after that the QDs were adsorbed on the TiO2 surface. The reversed type-I CdS/CdSe QDs show a much higher photon-to-current conversion efficiency than type-I CdSe/CdS and CdSe QDs without shell. Also, by chem.-bath depositing of CdS on the QD-sensitized electrode to form a quantum-well structure, the electron recombination between the QDs and the redox couple was reduced, hence further enhancing the electron-injection efficiency. The absorbed-photon-to-current efficiency of the quantum well CdS/CdSe/CdS sensitized solar cells reaches a value ≤60%. [on SciFinder(R)]
|
|
| 47. |
- Qu, Minni, et al.
(författare)
-
Interaction of bipolaron with the H2O/O-2 redox couple causes current hysteresis in organic thin-film transistors
- 2014
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 5, s. 3185-
-
Tidskriftsartikel (refereegranskat)abstract
- Hysteresis in the current–voltage characteristics is one of the major obstacles to the implementation of organic thin-film transistors in large-area integrated circuits. The hysteresis has been correlated either extrinsically to various charge-trapping/transfer mechanisms arising from gate dielectrics or surrounding ambience or intrinsically to the polaron–bipolaron reaction in low-mobility conjugated polymer thin-film transistors. However, a comprehensive understanding essential for developing viable solutions to eliminate hysteresis is yet to be established. By embedding carbon nanotubes in the polymer-based conduction channel of various lengths, here we show that the bipolaron formation/recombination combined with the H2O/O2 electrochemical reaction is responsible for the hysteresis in organic thin-film transistors. The bipolaron-induced hysteresis is a thermally activated process with an apparent activation energy of 0.29 eV for the bipolaron dissociation. This finding leads to a hysteresis model that is generally valid for thin-film transistors with both band transport and hopping conduction in semiconducting thin films.
|
|
| 48. |
- Shi, Wenming, et al.
(författare)
-
Urinary phthalate metabolites in relation to childhood asthmatic and allergic symptoms in Shanghai
- 2018
-
Ingår i: Environment International. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0160-4120 .- 1873-6750. ; 121, s. 276-286
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Few studies can be found on phthalate exposure in relation to childhood asthma and allergic symptoms from Mainland China, where a persistent increase in prevalence of childhood asthma and allergic disease has been observed. Objectives: This study aimed to assess the exposure levels to phthalates and its relationship with asthmatic and allergic symptoms among children in Shanghai, which has the highest prevalence of childhood asthma in Mainland China. Methods: A follow-up study (2013-2014) of 434 children aged 5-10 years was conducted, based on the China, Children, Homes, Health (CCHH) study (2011-2012) in Shanghai, China. Information on asthmatic and allergic symptoms (wheeze, rhinitis, and eczema) were collected using validated questionnaires. Ten phthalate metabolites in morning urine samples were analyzed by high-performance liquid chromatography with triple quadrupole tandem mass spectrometry (HPLC-MS/MS). Multivariable logistic regression was used to estimate the associations between symptoms and urinary phthalate metabolites controlling for demographics, family history of allergic diseases and other covariates. Results: Nine out of 10 phthalate metabolites were detected in all subjects (average detection rate of 93.2%). By multivariable logistic regression analyses, the 4th quartile of Mono-n-butyl phthalate (MnBP) (reference: 1st quartile) had adjusted prevalence odds ratios (aPORs) and 95% confidence intervals (95%CIs) of 2.27(1.06-4.88), 2.14(1.02-4.46) and 2.98(1.19-7.50) for wheeze, rhinitis and eczema, respectively, while those of Mono-isobutyl phthalate (MiBP) were 2.23(1.08-4.62) and 2.96(1.02-8.60) for rhinitis and eczema, respectively. The highest quartile of mono-2-ethyl-5-hydroxyhexyl phthalate(MEHHP) and mono 2 ethyl 5 ox ohexyl phthalate(MEOHP) had aPORs and 95%CIs of 3.10(1.10-8.74) and 2.63(1.02-6.80) for eczema, respectively. By summing up the 4 low molecular weight metabolites (Sigma 4LMWP) and all 9 metabolites (Sigma(9)Total), the highest quartiles of Sigma 4LMWP and Sigma(9)Total were significantly associated with all symptoms. In most of the above associations, a significantly increasing trend from the 1st to the 4th quartile was observed. Subjects with 2 or 3 concomitant symptoms (reference: no symptoms) had significant positive associations with a higher level (the 4th quartile) of phthalate metabolites. Conclusions: Low MW metabolites such as MnBP and MiBP, high MW DEHP and the total amount of phthalate metabolites might have adverse health effects on asthma and allergic symptoms in Chinese children.
|
|
| 49. |
- Tian, Shangjie, et al.
(författare)
-
Magnetic topological insulator MnBi6 Te10 with a zero-field ferromagnetic state and gapped Dirac surface states
- 2020
-
Ingår i: Physical Review B. - 2469-9950. ; 102:3
-
Tidskriftsartikel (refereegranskat)abstract
- Magnetic topological insulators (TIs) with nontrivial topological electronic structure and broken time-reversal symmetry exhibit various exotic topological quantum phenomena. The realization of such exotic phenomena at high temperature is one of the central topics in this area. We reveal that MnBi6Te10 is a magnetic TI with an antiferromagnetic ground state below 10.8 K whose nontrivial topology is manifested by Dirac-like surface states. The ferromagnetic axion insulator state with Z4=2 emerges once spins are polarized at a field as low as 0.1 T, accompanied with saturated anomalous Hall resistivity up to 10 K. Such a ferromagnetic state is preserved even with an external field down to zero at 2 K. Theoretical calculations indicate that the few-layer ferromagnetic MnBi6Te10 is also topologically nontrivial with a nonzero Chern number. Angle-resolved photoemission spectroscopy experiments further reveal three types of Dirac surface states arising from different terminations on the cleavage surfaces, one of which has insulating behavior with an energy gap of ∼28 meV at the Dirac point. These outstanding features suggest that MnBi6Te10 is a promising system to realize various topological quantum effects at zero field and high temperature.
|
|
| 50. |
- Wang, Bing, et al.
(författare)
-
Efficient organic mulch thickness for soil and water conservation in urban areas
- 2021
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- The use of organic mulch is important for urban green applications. For urban areas in arid and semiarid regions receiving short high-intensive rainfall, rainfall characteristics, and soil slope play an important role for mulch functioning. These properties of mulch were studied. For this purpose, rainfall simulation experiments using organic mulching were conducted in Jiufeng National Forestry Park to analyze the influence of organic mulch under different slope and heavy rainfall events. The results showed that soil water content displayed a decreasing tendency with increasing mulch application. Compared to bare soil, a mulch application of 0.25 kg/m2 and 0.50 kg/m2 led to maximum soil water content and maximum runoff decrease occurred for 0.50 kg/m2 mulch. Higher application rate of mulch displayed less soil water content and greater runoff. The runoff amount and runoff generation rate decreased by 28–83% and 21–83%, respectively, as compared to bare soil. With a mulch application of 0.25–1.00 kg/m2, soil drainage accounted for 56–60% of total rainfall. Overall, an efficient mulch application was found to be 0.25–0.50 kg/m2. The results of this study are relevant for arid and semiarid urban regions that experience heavy rainfall.
|
|
