| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 3. |
- Jin, Tingting, et al.
(författare)
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Efficient heterogeneous integration of InP/Si and GaSb/Si templates with ultra-smooth surfaces
- 2022
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Ingår i: Science China Information Sciences. - : Springer Science and Business Media LLC. - 1869-1919 .- 1674-733X. ; 65:8
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Tidskriftsartikel (refereegranskat)abstract
- Heterogeneous integration of InP and GaSb on Si substrates holds a huge potential interest in near-infrared and mid-infrared optoelectronic devices. In this study, 2-inch 180-nm-thick InP and 185-nm-thick GaSb thin layers were successfully transferred onto the Si substrates to form high-quality and ultra-smooth InP/Si and GaSb/Si templates using molecular beam epitaxy (MBE) and the ion-slicing technique together with selective chemical etching. The relocation of the implantation-introduced damage in the sacrificial layer enables the transfer of relatively defect-free InP and GaSb thin films. The sacrificial layers were completely etched off by selective chemical etching, leaving ultra-smooth epitaxial surfaces with a roughness of 0.2 nm for the InP/Si template and 0.9 nm for the GaSb/Si template, respectively. Thus, the chemical mechanical polishing (CMP) process was not required to smooth the surface which usually introduces particles and chemical contaminations on the transferred templates. Furthermore, the donor substrate is not consumed and can be recycled to reduce the cost, which provides a paradigm for the sustainable and economic development of the Si integration platform.
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| 4. |
- Jin, Taiyi, et al.
(författare)
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Environmental epidemiological study and estimation of benchmark dose for renal dysfunction in a cadmium-polluted area in China.
- 2004
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Ingår i: Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine. - : Kluwer Academic Publishers. - 0966-0844 .- 1572-8773. ; 17:5, s. 525-30
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Tidskriftsartikel (refereegranskat)abstract
- We have performed a study aimed at investigating the critical concentration of urinary cadmium (UCd) required for the development of renal dysfunction. We studied population groups (totally 790 persons) living in two cadmium exposed areas and one control area in China. UCd, was determined as an indicator of cadmium exposure and accumulation, while the concentrations of N-acetyl-beta-D-glucosaminidase (NAG), its iso-form B (NAG-B), beta2-microglobulin (B2M), retinol binding protein (RBP), and albumin (ALB) in urine were measured as indicators of the renal effects caused by cadmium. There was a significantly increased prevalence of hyperNAGuria, hyperNAG-Buria, hyperB2Muria, hyperRBPuria and hyperALBuria with increasing levels of Cd excretion in urine. We used the benchmark dose (BMD) procedure to estimate the critical concentration of urinary cadmium in this general population. The lower confidence limit of the BMD (LBMD-05) of urinary cadmium for a 5% level of risk above the background level was estimated for each of the renal effect indicators. The BMD-05/LBMD-05 were estimated to be 4.46/3.99, 6.70/5.87, 8.36/7.31, 7.98/6.98 and 15.06/12.18 microg/g creatinine for urinary NAG-B, NAG, B2M, RBP and ALB, respectively. Our findings suggest, based on the present study, that the Lower Confidence Limit of the Population Critical Concentration of UCd (LPCCUCd-05) of tubular dysfunction for 5% excess risk level above the background may be ca. 3-4 microg/g creatinine, and that cadmium concentration in urine should be kept below this level to prevent renal tubular damage. This report is the first to use the BMD method in this field and to define the concept of critical concentration in urine.
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| 5. |
- Jin, Taiyi, et al.
(författare)
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Osteoporosis and renal dysfunction in a general population exposed to cadmium in China.
- 2004
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Ingår i: Environmental research. - : Elsevier BV. - 0013-9351. ; 96:3, s. 353-9
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis is a common metabolic disease characterized by low bone mass and microarchitectural deterioration of bone tissue. Many factors are involved in the occurrence of osteoporosis. Cadmium can cause both osteomalacia and osteoporosis and these effects have long been investigated through various epidemiological or experimental studies. The present study examines a possible relationship between cadmium nephropathy and its effects on the skeleton in populations living in a polluted area in southeast China. Monophoton absorptiometry was used to measure bone mineral density in the population and the Z score (the number of SD from the difference between the measured bone density of the individual and the group mean value for sex- and age-matched controls) was introduced to define osteoporosis (Z score < -2). Osteoporosis caused by cadmium exposure was demonstrated in this study on a general population environmentally exposed to cadmium in China. It was found that there were significant differences in the prevalence of osteoporosis among the different urinary cadmium groups (chi2 = 18.84, P = 0.0008). The linear trend test gave chi2 = 16.281, P = 0.00005. There was a dose-response relationship between cadmium exposure (urinary cadmium) and prevalence of osteoporosis. Of 31 subjects with osteoporosis, 23 subjects were suffering from renal dysfunction. The prevalence of renal dysfunction (74.19%) was significantly higher than that in those without osteoporosis (chi2 = 16.53, P < 0.001). Stratum analysis was performed to further assess the relationship between bone damage and renal impairment caused by cadmium. There was a significant difference between those with and without tubular damage (chi2 = 19.92, P = 0.000) but not in those with and without glomerular damage (chi2 = 0.08, P = 0.114). This showed that glomerular dysfunction plays a smaller role than tubular dysfunction in the causation of bone damage. It was found that the prevalence of osteoporosis increases with increasing values of parameters of tubular damage. Osteoporosis caused by cadmium is thus related to kidney dysfunction and especially to tubular damage and its severity but not to glomerular damage. The present study has thus demonstrated the combined adverse effects (osteoporosis and renal dysfunction) caused by environmental exposure to cadmium for the first time in Asia outside the endemic area in Japan.
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| 6. |
- Jin, Taiyi, et al.
(författare)
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Renal dysfunction of cadmium-exposed workers residing in a cadmium-polluted environment.
- 2004
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Ingår i: Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine. - : Kluwer Academic Publishers. - 0966-0844 .- 1572-8773. ; 17:5, s. 513-8
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Tidskriftsartikel (refereegranskat)abstract
- Human exposure to cadmium may occur in both occupational and general environments. We were interested in determining whether a combination of occupational and environmental exposure to cadmium results in different levels of severity of renal dysfunction relative to that arising from environmental or occupational exposure alone. We selected 44 residents, who once were employed in a smelter and lived in a cadmium-polluted area, as group A. Another 88 subjects, who never worked in the plant, but lived in the same area, were selected as group B. Group C consisted of 88 subjects who had no history of occupational exposure to cadmium and lived in a non-cadmium-polluted area. Statistical analysis demonstrated that there was no significant difference in age or gender among the three groups, nor were there significant differences in smoking habits. The prevalence of renal dysfunction as indicated by increased excretion of beta2-microglobulin (B2M), N-acetyl-beta-D-glucosaminidase (NAG) and albumin (ALB), was higher in group A than in group B. This finding suggests that exposure to cadmium both occupationally and environmentally results in a higher prevalence of renal dysfunction, relative to those who are exposed to cadmium only in the general environment. Therefore, this specific population, who once were occupationally exposed to cadmium and lived in polluted areas, should be identified. Furthermore, health examinations of this population should be conducted in time to prevent further health damage induced by cadmium exposure.
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| 7. |
- Li, Qianjin, et al.
(författare)
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Synthesis of highly selective molecularly imprinted nanoparticles by a solid-phase imprinting strategy for fluorescence turn-on recognition of phospholipid
- 2022
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 368
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Tidskriftsartikel (refereegranskat)abstract
- Molecularly imprinted polymers (MIPs) are artificial receptors with template tailored recognition sites complementary to the targets. The versatility of this molecular imprinting technique has been hampered by the lack of practical synthetic procedures to prepare highly selective MIP nanoparticles targeting phospholipids, which are challenging to be imprinted due to their amphiphilic structure. Here, a novel sedimentation-based solid phase imprinting strategy is introduced relying on polymerization in the presence of template-modified silica nanospheres (SNs). To demonstrate this concept, the sphingosine-1-phosphate receptor agonist fingolimod phosphate (FP) was coupled to SNs which were dispersed in the prepolymerization medium consisting of the fluorescent functional monomer 1,8-bis(N-vinylimidazol-N'-methyl)anthracene bromide and the crosslinking monomer ethyleneglycol dimethacrylate. High dilution polymerization of the dispersion under agitation followed by simple sedimentation-based separation of the SN template resulted in the isolation of surface imprinted fluorescent MIP nanoparticles (FMIP NPs) in a high yield (17 %). The FMIP NPs displayed fluorescence enhancement in response to the template with a high imprinting factor (IF=9) under the experimental conditions and good specificity, and could recognize FP in human serum with recoveries of 68-74 %. Moreover, the template-modified SNs could be recycled for reuse. Such molecular imprinting strategy opens a new approach to produce highly selective artificial receptors targeting phospholipids.
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| 8. |
- Liang, Hao, et al.
(författare)
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InAs/GaAs quantum dot laser epitaxially grown on on-axis (001) GaAsOI substrate
- 2021
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Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 29:23, s. 38465-38476
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Tidskriftsartikel (refereegranskat)abstract
- Quantum dot (QD) laser as a light source for silicon optical integration has attracted great research attention because of the strategic vision of optical interconnection. In this paper, the communication band InAs QD ridge waveguide lasers were fabricated on GaAs-on-insulator (GaAsOI) substrate by combining ion-slicing technique and molecular beam epitaxy (MBE) growth. On the foundation of optimizing surface treatment processes, the InAs/In0.13Ga0.87As/GaAs dot-in-well (DWELL) lasers monolithically grown on a GaAsOI substrate were realized under pulsed operation at 20 °C. The static device measurements reveal comparable performance in terms of threshold current density, slope efficiency and output power between the QD lasers on GaAsOI and GaAs substrates. This work shows great potential to fabricate highly integrated light source on Si for photonic integrated circuits.
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| 9. |
- Lin, Jiajie, et al.
(författare)
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Wafer-scale heterogeneous integration InP on trenched Si with a bubble-free interface
- 2020
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Ingår i: APL Materials. - : AIP Publishing. - 2166-532X. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- Heterogeneous integration of compound semiconductors on a Si platform leads to advanced device applications in the field of Si photonics and high frequency electronics. However, the unavoidable bubbles formed at the bonding interface are detrimental for achieving a high yield of dissimilar semiconductor integration by the direct wafer bonding technology. In this work, lateral outgassing surface trenches (LOTs) are introduced to efficiently inhibit the bubbles. It is found that the chemical reactions in InP-Si bonding are similar to those in Si-Si bonding, and the generated gas can escape via the LOTs. The outgassing efficiency is dominated by LOTs' spacing, and moreover, the relationship between bubble formation and the LOT's structure is well described by a thermodynamic model. With the method explored in this work, a 2-in. bubble-free crystalline InP thin film integrated on the Si substrate with LOTs is obtained by the ion-slicing and wafer bonding technology. The quantum well active region grown on this Si-based InP film shows a superior photoemission efficiency, and it is found to be 65% as compared to its bulk counterpart.
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| 10. |
- Shi, Chen, et al.
(författare)
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Comprehensive Landscape of Heparin Therapy for COVID-19
- 2021
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Ingår i: Carbohydrate Polymers. - OXFORD ENGLAND : Elsevier. - 0144-8617 .- 1879-1344. ; 254
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Forskningsöversikt (refereegranskat)abstract
- The pandemic coronavirus disease 2019 (COVID-19), caused by the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is rapidly spreading globally. Clinical observations found that systemic symptoms caused by SARS-CoV-2 infection are attenuated when using the anticoagulant agent heparin, indicating that heparin may play other roles in managing COVID-19, in addition to prevention of pulmonary thrombosis. Several biochemical studies show strong binding of heparin and heparin-like molecules to the Spike protein, which resulted in inhibition of viral infection to cells. The clinical observations and in vitro studies argue for a potential multiple-targeting effects of heparin. However, adverse effects of heparin administration and some of the challenges using heparin therapy for SARS-CoV-2 infection need to be considered. This review discusses the pharmacological mechanisms of heparin regarding its anticoagulant, anti-inflammatory and direct antiviral activities, providing current evidence concerning the effectiveness and safety of heparin therapy for this major public health emergency.
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