| 1. |
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| 2. |
- Wang, Zhaoming, et al.
(author)
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Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33
- 2014
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In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 23:24, s. 6616-6633
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Journal article (peer-reviewed)abstract
- Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.
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| 3. |
- Klionsky, Daniel J., et al.
(author)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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In: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Research review (peer-reviewed)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.
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| 4. |
- Bao, Qinye, et al.
(author)
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Energy Level Alignment of N-Doping Fullerenes and Fullerene Derivatives Using Air-Stable Dopant
- 2017
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In: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 9:40, s. 35476-35482
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Journal article (peer-reviewed)abstract
- Doping has been proved to be one of the powerful technologies to achieve significant improvement in the performance of organic electronic devices. Herein, we systematically map out the interface properties of solution-processed air-stable n-type (4(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)phenyl) doping fullerenes and fullerene derivatives and establish a universal energy level alignment scheme for this class of n-doped system. At low doping levels at which the charge-transfer doping induces mainly bound charges, the energy level alignment of the n-doping organic semiconductor can be described by combining integer charger transfer-induced shifts with a so-called double-dipole step. At high doping levels, significant densities of free charges are generated and the charge flows between the organic film and the conducting electrodes equilibrating the Fermi level in a classic "depletion layer" scheme. Moreover, we demonstrate that the model holds for both n- and p-doping of pi-backbone molecules and polymers. With the results, we provide wide guidance for identifying the application of the current organic n-type doping technology in organic electronics.
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| 5. |
- Bao, Qinye, et al.
(author)
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The Effect of Oxygen Uptake on Charge Injection Barriers in Conjugated Polymer Films
- 2018
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In: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 10:7, s. 6491-6497
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Journal article (peer-reviewed)abstract
- The energy offset between the electrode Fermi level and organic semiconductor transport levels is a key parameter controlling the charge injection barrier and hence efficiency of organic electronic devices. Here, we systematically explore the effect of in situ oxygen exposure on energetics in n-type conjugated polymer P(NDI2OD-T2) films. The analysis reveals that an interfacial potential step is introduced for a series of P(NDI2OD-T2) electrode contacts, causing a nearly constant downshift of the vacuum level, while the ionization energies versus vacuum level remain constant. These findings are attributed to the establishment of a so-called double-dipole step via motion of charged molecules and will modify the charge injection barriers at electrode contact. We further demonstrate that the same behavior occurs when oxygen interacts with p-type polymer TQ1 films, indicating it is possible to be a universal effect for organic semiconductOrs.
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| 6. |
- Guo, Xuewen, et al.
(author)
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Novel small-molecule zwitterionic electrolyte with ultralow work function as cathode modifier for inverted polymer solar cells
- 2018
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In: Organic electronics. - : ELSEVIER SCIENCE BV. - 1566-1199 .- 1878-5530. ; 59, s. 15-20
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Journal article (peer-reviewed)abstract
- Interfacial compatibility between the electrode and organic semiconductor plays a critical role in controlling the charge transport and hence efficiency of organic solar cell. Here, we introduce a novel small-molecule zwitterionic electrolyte (S1) combined with ZnO as electron transporting interlayer employed for the inverted PTB7:PC71BM bulk heterojunction solar cell. The resulting device with the S1/ZnO stacked interlayer achieves a high PCE of 8.59%, obtaining a 16.2% improvement over the control device performance of 7.4% without the S1 attributed to the significant increased short-circuit current density and fill factor. The interfacial properties are investigated. It is found that the S1/ZnO interlayer possess an ultralow work function of 3.6 eV, which originates from the interfacial double dipole step induced by the zwitterionic side chain electrostatic realignment at interface. The S1/ZnO interlayer exhibits the excellent charge extraction ability, suppresses the charge recombination loss and decreases the series resistance at the active layer/electrode contact.
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| 7. |
- Guo, Xuewen, et al.
(author)
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Understanding the effect of N2200 on performance of J71 : ITIC bulk heterojunction in ternary non-fullerene solar cells
- 2019
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In: Organic electronics. - : Elsevier. - 1566-1199 .- 1878-5530. ; 71, s. 65-71
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Journal article (peer-reviewed)abstract
- None-fullerene solar cells with ternary architecture have attracted much attention because it is an effective approach for boosting the device power conversion efficiency. Here, the crystalline polymer N2200 as the third component is integrated into J71: ITIC bulk heterojunction. A series of characterizations indicate that N2200 could increase photo-harvesting, balanced hole and electron mobilities, enhanced exciton dissociation, and suppressed charge recombination, which result in the comprehensive improvement of open circuit voltage, short circuit current and fill factor in the device. Moreover, after introduction of N2200, the morphology of the ternary active layer is optimized, and the film crystallinity is improved. This work demonstrates that adding a small quantity of high crystallization acceptor into non-fullerene donor: acceptor mixture is a promising strategy toward developing high-performance organic solar cells.
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| 8. |
- Huang, Qiangsheng, et al.
(author)
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Ultracompact tapered coupler for the Si/III-V heterogeneous integration
- 2015
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In: Applied Optics. - 1559-128X .- 2155-3165. ; 54:14, s. 4327-4332
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Journal article (peer-reviewed)abstract
- An ultracompact tapered coupler, which is suitable for mode transformation between a 220 nm high silicon wire waveguide and a Si/III-V hybrid waveguide, is proposed for Si/III-V heterogeneous integration. The tapered coupler is composed of three sections. Since the tapered coupler avoids exciting the unwanted high-order modes in the III-V waveguide, the length of the tapered coupler can be dramatically shortened. In the proposed structure, the total length of the trisectional tapered coupler can be as short as 8 mu m with a fundamental mode-coupling efficiency of over 95% in a bandwidth of over 100 nm. The alignment tolerance of the proposed structure is also analyzed.
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| 9. |
- Sun, Xianqiang, et al.
(author)
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Residues remote from the binding pocket control the antagonist selectivity towards the corticotropin-releasing factor receptor-1
- 2015
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5, s. 8066-
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Journal article (peer-reviewed)abstract
- The corticotropin releasing factors receptor-1 and receptor-2 (CRF1R and CRF2R) are therapeutic targets for treating neurological diseases. Antagonists targeting CRF1R have been developed for the potential treatment of anxiety disorders and alcohol addiction. It has been found that antagonists targeting CRF1R always show high selectivity, although CRF1R and CRF2R share a very high rate of sequence identity. This has inspired us to study the origin of the selectivity of the antagonists. We have therefore built a homology model for CRF2R and carried out unbiased molecular dynamics and well-tempered metadynamics simulations for systems with the antagonist CP-376395 in CRF1R or CRF2R to address this issue. We found that the side chain of Tyr(6.63) forms a hydrogen bond with the residue remote from the binding pocket, which allows Tyr(6.63) to adopt different conformations in the two receptors and results in the presence or absence of a bottleneck controlling the antagonist binding to or dissociation from the receptors. The rotameric switch of the side chain of Tyr356(6.63) allows the breaking down of the bottleneck and is a perquisite for the dissociation of CP-376395 from CRF1R.
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| 10. |
- Tang, Yong, et al.
(author)
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Enhancement of fermentable sugar yield by competitive adsorption of non-enzymatic substances from yeast and cellulase on lignin
- 2014
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In: BMC Biotechnology. - : Springer Science and Business Media LLC. - 1472-6750. ; 14
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Journal article (peer-reviewed)abstract
- Background: Enhancement of enzymatic digestibility by some supplementations could reduce enzyme loading and cost, which is still too high to realize economical production of lignocellulosic biofuels. A recent study indicates that yeast hydrolysates (YH) have improved the efficiency of cellulases on digestibility of furfural residues (FR). In the current work, the components of YH were separated by centrifugation and size exclusion chromatography and finally characterized in order to better understand this positive effect. Results: A 60.8% of nitrogen of yeast cells was remained in the slurry (YHS) after hydrothermal treatment. In the supernatant of YH (YHL), substances of high molecular weight were identified as proteins and other UV-absorbing compounds, which showed close molecular weight to components of cellulases. Those substances attributed to a synergetic positive effect on enzymatic hydrolysis of FR. The fraction of YHL ranged from 1.19 to 2.19 mL (elution volume) contained over 50% of proteins in YHL and had the best performance in stimulating the release of glucose. Experiment results proved the adsorption of proteins in YHL on lignin. Conclusions: Supplementation of cellulases with YH enhances enzymatic digestibility of FR mainly by a competitive adsorption of non-enzymatic substances on lignin. The molecular weight of these substances has a significant impact on their performance. Different strategies can be used for a good utilization of yeast cells in terms of biorefinery concept.
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| 11. |
- Xiao, Wei, et al.
(author)
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Exploring Red, Green, and Blue Light-Activated Degradation of Perovskite Films and Solar Cells for Near Space Applications
- 2020
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In: Solar RRL. - : Wiley-VCH Verlagsgesellschaft. - 2367-198X. ; 4:3
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Journal article (peer-reviewed)abstract
- Hybrid perovskite solar cells with a high specific power have great potential to become promising power sources mounted on spacecrafts in space applications. However, there is a lack of study on their photostability as light absorbers in those conditions. Herein, the stability of the perovskite films and solar cells under red, green, and blue (RGB) light illumination in medium vacuum that belongs to near space is explored. The perovskite active layers exhibit different degradations from morphological, chemical, and structural points of view. This is attributed to the strong coupling between photoexcited carriers and the crystal lattice and the diversity of RGB light absorption in the perovskite films. Device characterizations reveal that the efficiency loss of perovskite solar cells results from not only perovskite degradation, but also the photoexcited carriers reducing the energy barrier of ion migration and accelerating the migration to generate more deep-level trap defects. Moreover, comparative devices suggest that the well encapsulation can weaken the effect of vacuum on stability.
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| 12. |
- Yang, Jianming, et al.
(author)
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Comprehensive understanding of heat-induced degradation of triple-cation mixed halide perovskite for a robust solar cell
- 2018
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In: Nano Energy. - : ELSEVIER SCIENCE BV. - 2211-2855 .- 2211-3282. ; 54, s. 218-226
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Journal article (peer-reviewed)abstract
- The triple-cation mixed halide perovskite Cs-0.05(MA(0.17)FA(0.83))(0.95)Pb(I0.83Br0.17)(3) emerges as one of the most promising candidates for photovoltaics due to superior optoelectronic properties, but the thermal stability is still a major challenge for the viability of perovskite solar cells towards commercialization. Herein, we firstly explore the thermal response of the photovoltaic performances to access device physical changes. It is shown that the efficiency loss originates from decreased charge mobility, increased trap density and generation of PbI2 charge recombination centers near the interface. In-depth analysis of evolutions in morphology, chemical composition, dynamic and electronic structure of the perovskite layer at the nanometer scales indicates that it is initial dangling bonds and vacancies on the imperfect surfaces decrease the activation energy and cause the perovskite decomposition in a layer-by-layer pathway sequentially from the film surface to bulk. Based on the results, a strategy of surface passivation to improve the thermal stability is demonstrated and discussed. This work for the first time provides insights into the physical and chemical change of such triple-cation perovskite and indicates that more effort should be invested in surface treatment for enhancing perovskite device stability.
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| 13. |
- Yang, Jianming, et al.
(author)
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Extremely Low-Cost and Green Cellulose Passivating Perovskites for Stable and High-Performance Solar Cells
- 2019
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In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 11:14, s. 13491-13498
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Journal article (peer-reviewed)abstract
- The fast evolution of metal halide perovskite solar cells has opened a new chapter in the field of renewable energy. High-quality perovskite films as the active layers are essential for both high efficiency and long-term stability. Here, the perovskite films with enlarged crystal grain size and decreased defect density are fabricated by introducing the extremely low-cost and green polymer, ethyl cellulose (EC), into the perovskite layer. The addition of EC triggers hydrogen bonding interactions between EC and the perovskite, passivating the charge defect traps at the grain boundaries. The long chain of EC further acts as a scaffold for the perovskite structure, eliminating the annealing-induced lattice strain during the film fabrication process. The resulting devices with the EC additive exhibit a remarkably enhanced average power conversion efficiency from 17.11 to 19.27% and an improvement of all device parameters. The hysteresis index is found to decrease by three times from 0.081 to 0.027, which is attributed to suppressed ion migration and surface charge trapping. In addition, the defect passivation by EC significantly improves the environmental stability of the perovskite films, yielding devices that retain 80% of their initial efficiency after 30 days in ambient air at 45% relative humidity, whereas the pristine devices without EC fully degrade. This work provides a low-cost and green avenue for passivating defects that improves both the efficiency and operational stability of perovskite solar cells.
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| 14. |
- Yang, Jianming, et al.
(author)
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Oxygen- and Water-Induced Energetics Degradation in Organometal Halide Perovskites
- 2018
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In: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 10:18, s. 16225-16230
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Journal article (peer-reviewed)abstract
- Organometal halide perovskites are under rapid development, and significant focus has been placed on their stability that currently presents a major obstacle for practical application. Energetics plays a vital role in charge injection/extraction and transport properties in devices. Here, we in situ investigate oxygen and water-induced energetics degradation in organometal halide perovskite films. Oxygen gas induces an upward shift of the vacuum level of the perovskite films because of the formation of an oxygen induced surface dipole, water vapor causes a significant vacuum-level downshift, and the valence band binding energy referenced to the Fermi level simultaneously increases so as to keep the ionization potential of the perovskite films unchanged. Moreover, the chemical compositions, crystalline structures, surface morphologies, and dynamical properties also are monitored and analyzed in detail. These results are indispensable to understand the degradation mechanisms and to perform the optimizations of stable materials and devices in the future.
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| 15. |
- Yang, Jianming, et al.
(author)
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Unraveling Photostability of Mixed Cation Perovskite Films in Extreme Environment
- 2018
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In: Advanced Optical Materials. - : WILEY-V C H VERLAG GMBH. - 2162-7568 .- 2195-1071. ; 6:20
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Journal article (peer-reviewed)abstract
- Organometal halide perovskites exhibit a bright future for applications in solar cells, as efficiency has achieved over 22%. The long-term stability remains a major obstacle for commercialization. Here, it is found that three cationic compositional engineered perovskites, MAPb(I0.83Br0.17)(3), FA(0.83)MA(0.17)Pb(I0.83Br0.17)(3), and Cs-0.1(FA(0.83)MA(0.17))(0.9)Pb(I0.83Br0.17)(3), undergo severe degradation under white-light illumination in ultrahigh vacuum (UHV) environment, but the rate of degradation is significantly lower for the mixed cation perovskites. This is attributed to the defect-induced trap states that trigger the strong coupling between the photoexcited carriers and the crystal lattice. The observed behavior supports the view of the mixed cations suppressing the photoinduced degradation. It is further demonstrated that UHV environment remarkably accelerates the degradation of the perovskite films under illumination, which delivers a very important message that the current hybrid perovskite materials and their optoelectronic devices are not suitable for application in outer space. Moreover, the applied UHV environment can be an accelerated test method to estimate the photostability of the perovskites.
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| 16. |
- Yong, Tang, et al.
(author)
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Simultaneous saccharification and cofermentation of lignocellulosic residues from commercial furfural production and corn kernels using different nutrient media
- 2011
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In: Biotechnology for Biofuels. - : Springer Science and Business Media LLC. - 1754-6834. ; 4:22, s. 1-10
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Journal article (peer-reviewed)abstract
- Abstract Background: As the supply of starch grain and sugar cane, currently the main feedstocks for bioethanol production, become limited, lignocelluloses will be sought as alternative materials for bioethanol production. Production of cellulosic ethanol is still cost-inefficient because of the low final ethanol concentration and the addition of nutrients. We report the use of simultaneous saccharification and cofermentation (SSCF) of lignocellulosic residues from commercial furfural production (furfural residue, FR) and corn kernels to compare different nutritional media. The final ethanol concentration, yield, number of live yeast cells, and yeast-cell death ratio were investigated to evaluate the effectiveness of integrating cellulosic and starch ethanol. Results: Both the ethanol yield and number of live yeast cells increased with increasing corn-kernel concentration, whereas the yeast-cell death ratio decreased in SSCF of FR and corn kernels. An ethanol concentration of 73.1 g/L at 120 h, which corresponded to a 101.1% ethanol yield based on FR cellulose and corn starch, was obtained in SSCF of 7.5% FR and 14.5% corn kernels with mineral-salt medium. SSCF could simultaneously convert cellulose into ethanol from both corn kernels and FR, and SSCF ethanol yield was similar between the organic and mineralsalt media. Conclusions: Starch ethanol promotes cellulosic ethanol by providing important nutrients for fermentative organisms, and in turn cellulosic ethanol promotes starch ethanol by providing cellulosic enzymes that convert the cellulosic polysaccharides in starch materials into additional ethanol. It is feasible to produce ethanol in SSCF of FR and corn kernels with mineral-salt medium. It would be cost-efficient to produce ethanol in SSCF of high concentrations of water-insoluble solids of lignocellulosic materials and corn kernels. Compared with prehydrolysis and fed-batch strategy using lignocellulosic materials, addition of starch hydrolysates to cellulosic ethanol production is a more suitable method to improve the final ethanol concentration.
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