135 research outputs found
Ultrafast heterogeneous electron transfer reactions Comparative theoretical studies on time and frequency domain data
Recent theoretical studies on linear absorption spectra of dye semiconductor systems perylene attached to nanostructured TiO2, L. Wang et al., J. Phys. Chem. B 109, 9589 2005 are extended here in different respects. Since the systems show ultrafast photoinduced heterogeneous electron transfer the time dependent formulation used to compute the absorbance is also applied to calculate the temporal evolution of the sub 100 fs charge injection dynamics after a 10 fs laser pulse excitation. These studies complement our recent absorption spectra fit for two perylene bridge anchor group TiO2 systems. Moreover, the time dependent formulation of the absorbance is confronted with a frequency domain description. The latter underlines the central importance of the self energy caused by the coupling of the dye levels to the semiconductor band continuum. The used model is further applied to study the effect of different parameters such as 1 the dependence on the reorganization energies of the involved intramolecular transitions, 2 the effect of changing the transfer integral which couples the excited dye state with the band continuum, and 3 the effect of the concrete form of the semiconductor band density of states. Emphasis is also put on the case where the charge injection level of the dye is near or somewhat below the band edge. This nicely demonstrates the change from a structureless absorption to a well resolved vibrational progression including characteristic shifts of the absorption lines which are a direct measure for the dye semiconductor couplin
Serum uromodulin and progression of kidney disease in patients with chronic kidney disease
Abstract
Background
Uromodulin is specifically synthesized and secreted by kidney tubular epithelial cells. Studies on the association of serum uromodulin and outcomes of chronic kidney disease (CKD) are lacking. This study aimed to evaluate whether serum uromodulin was associated with outcomes of patients with CKD.
Methods
We measured serum uromodulin concentrations by ELISA in 2652 CKD patients from the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE) and investigated the association of serum uromodulin with outcomes of CKD patients, including end-stage kidney disease (ESKD) receiving kidney replacement therapy, cardiovascular events and mortality by Cox proportional hazards regression model.
Results
A total of 2652 CKD patients were enrolled in this study, with an age of 48.7 ± 13.8 years and the baseline eGFR of 49.6 ± 29.4 mL/min/1.73 m2, of whom 58.4% were male. The median level of urinary albumin/creatinine ratio and serum uromodulin was 473.7 mg/g (IQR 134.1–1046.6 mg/g) and 77.2 ng/mL (IQR 48.3–125.9 ng/mL), respectively. Altogether, 404 ESKD, 189 cardiovascular events, and 69 deaths occurred during the median follow-up of 53.6 (IQR 44.0–64.0) months. Lower levels of serum uromodulin were independently associated with higher risk of incident ESKD after adjusting for traditional cardiovascular risk factors, with the hazard ratios (HRs) of 3.23 (95% confidence intervals [CIs] 2.15–4.85) for the middle tertile and 7.47 (95% CI 5.06–11.03) for the bottom tertile, compared with top tertile and 0.31 (95% CI 0.25–0.38) per every standard deviation increase. After further adjustment for the baseline eGFR, the association was greatly attenuated, but still significant, with HRs of 1.92 (95% CI 1.26–2.90) for the bottom tertile compared with top tertile and 0.69 (95% CI 0.55–0.86) per every standard deviation increase.
Conclusions
Serum uromodulin is independently associated with an increased risk of incident ESKD in CKD patients.https://deepblue.lib.umich.edu/bitstream/2027.42/146520/1/12967_2018_Article_1693.pd
The Underpricing of Venture Capital Backed IPOs in China
This paper measures the influence of venture capital (VC) on IPO valuations in China. It is found that the authentication effect is dominated by the grandstanding effect, suggesting that VC firms in China greatly value their reputations. It is also shown that the market-specific characteristics of non-VC-backed firms are more closely related to their initial returns, compared to those of VC-backed firms. In addition, corporate fundamentals play a more important role in the valuation for VC-backed firms than for non-VC-backed firms
The Underpricing of Venture Capital Backed IPOs in China
This paper measures the influence of venture capital (VC) on IPO valuations in China. It is found that the authentication effect is dominated by the grandstanding effect, suggesting that VC firms in China greatly value their reputations. It is also shown that the market-specific characteristics of non-VC-backed firms are more closely related to their initial returns, compared to those of VC-backed firms. In addition, corporate fundamentals play a more important role in the valuation for VC-backed firms than for non-VC-backed firms
N′-[(5-Methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)(thioÂphen-2-yl)methylÂidene]benzohydrazide
In the title compound, C22H18N4O2S, the seven-membered ring generated by an intraÂmolecular N—H⋯O hydrogen bond adopts an envelope conformation in both of the two independent molÂecules in the asymmetric unit. In the crystal, molÂecules are linked into C(9) chains along [100] by N—H⋯O hydrogen bonds. The molÂecules are also weakly linked by C—H⋯O and C—H⋯N interÂactions, forming dimers with edge-connected R
2
2(9) rings. The dimers are interÂlinked by further weak C—H⋯N hydrogen bonds into chains along [010]
Neutrophil-to-lymphocyte ratio and incident end-stage renal disease in Chinese patients with chronic kidney disease: results from the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE)
Abstract
Background
Chronic kidney disease (CKD) leads to end-stage renal failure and cardiovascular events. An attribute to these progressions is abnormalities in inflammation, which can be evaluated using the neutrophil-to-lymphocyte ratio (NLR). We aimed to investigate the association of NLR with the progression of end stage of renal disease (ESRD), cardiovascular disease (CVD) and all-cause mortality in Chinese patients with stages 1–4 CKD.
Methods
Patients with stages 1–4 CKD (18–74 years of age) were recruited at 39 centers in 28 cities across 22 provinces in China since 2011. A total of 938 patients with complete NLR and other relevant clinical variables were included in the current analysis. Cox regression analysis was used to estimate the association between NLR and the outcomes including ESRD, CVD events or all-cause mortality.
Results
Baseline NLR was related to age, hypertension, serum triglycerides, total serum cholesterol, CVD history, urine albumin to creatinine ratio (ACR), chronic kidney disease-mineral and bone disorder (CKD-MBD), hyperlipidemia rate, diabetes, and estimated glomerular filtration rate (eGFR). The study duration was 4.55 years (IQR 3.52–5.28). Cox regression analysis revealed an association of NLR and the risk of ESRD only in patients with stage 4 CKD. We did not observe any significant associations between abnormal NLR and the risk of either CVD or all-cause mortality in CKD patients in general and CKD patients grouped according to the disease stages in particular.
Conclusion
Our results suggest that NLR is associated with the risk of ESRD in Chinese patients with stage 4 CKD. NLR can be used in risk assessment for ESRD among patients with advanced CKD; this application is appealing considering NLR being a routine test.
Trial registration ClinicalTrials.gov Identifier NCT03041987. Registered January 1, 2012. (retrospectively registered) (
https://www.clinicaltrials.gov/ct2/show/NCT03041987?term=Chinese+Cohort+Study+of+Chronic+Kidney+Disease+%28C-STRIDE%29&rank=1
)https://deepblue.lib.umich.edu/bitstream/2027.42/148285/1/12967_2019_Article_1808.pd
Seasonality of the transmissibility of hand, foot and mouth disease: a modelling study in Xiamen City, China.
This study attempts to figure out the seasonality of the transmissibility of hand, foot and mouth disease (HFMD). A mathematical model was established to calculate the transmissibility based on the reported data for HFMD in Xiamen City, China from 2014 to 2018. The transmissibility was measured by effective reproduction number (Reff) in order to evaluate the seasonal characteristics of HFMD. A total of 43 659 HFMD cases were reported in Xiamen, for the period 2014 to 2018. The median of annual incidence was 221.87 per 100 000 persons (range: 167.98/100,000-283.34/100 000). The reported data had a great fitting effect with the model (R2 = 0.9212, P < 0.0001), it has been shown that there are two epidemic peaks of HFMD in Xiamen every year. Both incidence and effective reproduction number had seasonal characteristics. The peak of incidence, 1-2 months later than the effective reproduction number, occurred in Summer and Autumn, that is, June and October each year. Both the incidence and transmissibility of HFMD have obvious seasonal characteristics, and two annual epidemic peaks as well. The peak of incidence is 1-2 months later than Reff
Optomechanical effects in nanocavity-enhanced resonant Raman scattering of a single molecule
In this paper, we address the optomechanical effects in surface-enhanced resonant Raman scattering (SERRS) from a single molecule in a nanoparticle on mirror (NPoM) nanocavity by developing a quantum master-equation theory, which combines macroscopic quantum electrodynamics and electron-vibration interaction within the framework of open quantum system theory. We supplement the theory with electromagnetic simulations and time-dependent density functional theory calculations in order to study the SERRS of a methylene blue molecule in a realistic NPoM nanocavity. The simulations allow us not only to identify the conditions to achieve conventional optomechanical effects, such as vibrational pumping, nonlinear scaling of Stokes and anti-Stokes scattering, but also to discovery distinct behaviors, such as the saturation of exciton population, the emergence of Mollow triplet side bands, and higher-order Raman scattering. All in all, our study might guide further investigations of optomechanical effects in resonant Raman scattering.This work is supported by the Projects No. 12004344 and No. 21902148 from the National Nature Science Foundation of China, joint Project No. 21961132023 from the NSFC-DPG, Project No. PID2019-107432GB-I00 from the Spanish Ministry of Science and Innovation, and Grant No. IT1526-22 for consolidated groups of the Basque University, through the Department of Education, Research, and Universities of the Basque Government.Peer reviewe
Ocular fundus pathology and chronic kidney disease in a Chinese population
<p>Abstract</p> <p>Background</p> <p>Previous study indicated a high prevalence of ocular fundus pathology among patients with chronic kidney disease (CKD), while the relationship between them has never been explored in a Chinese Population.</p> <p>Methods</p> <p>This cross-sectional study included 9 670 participants enrolled in a medical screening program. Ocular fundus examination was performed by ophthalmologists using ophthalmoscopes. The presence of eGFR less than 60 mL/min/1.73 m<sup>2 </sup>and/or proteinuria was defined as CKD.</p> <p>Results</p> <p>Compared to participants without CKD, participants with CKD had higher prevalence of retinopathy (28.5% vs. 16.3%, P < 0.001), glaucoma suspect (3.1% vs. 1.8%, P = 0.004), age-related macular degeneration (1.7% vs. 0.9%, P = 0.01) and overall eye pathology (32.0% vs. 19.4%, P < 0.001). After adjusting for potential confounders, the odds ratio of proteinuria for overall eye pathology and retinopathy was 1.29 (95% confidence interval [CI] 1.07-1.55) and 1.37 (95% CI 1.12-1.67), respectively. The results were robust after excluding participants with hypertension or with diabetes.</p> <p>Conclusions</p> <p>Ocular fundus pathology is common among Chinese patients with CKD. Regular eye exam among persons with proteinuria is warranted.</p
Quantitative real-time RT-PCR validation of differential mRNA expression of SPARC, FADD, Fascin, COL7A1, CK4, TGM3, ECM1, PPL and EVPL in esophageal squamous cell carcinoma
BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the most malignant tumors and typically presents at an advanced and rapidly fatal stage. To better understand the role of genetics in the etiology and prevention of ESCC and to identify potential susceptibility genes as well as early detection markers, we previously compared tumor and matched normal tissues from ESCC patients from a high-risk area of China using cDNA expression microarrays and identified 41 differentially-expressed genes (13 over-expressed and 28 under-expressed). METHODS: In the current study, we validated and quantitated differential mRNA expression in a sample of nine of these 41 genes, including four that were over-expressed (SPARC, FADD, Fascin, COL7A1), and five that were under-expressed (CK4, TGM3, ECM1, PPL, EVPL), in 75 new ESCC patients using quantitative Real-time RT-PCR and the 2(-ΔΔCT )method to examine both tumor and matched normal tissue. In addition, we examined expression patterns for these genes by selected demographic and clinical characteristics. RESULTS: Four previously over-expressed (tumor ≥2-fold normal) genes were all increased in the majority of new ESCC patients: SPARC was increased in 71% of patients, Fascin in 70%, FADD in 63%, and COL7A1 in 57%. Five previously under-expressed (tumor ≤0.5-fold normal) genes similarly showed decreased mRNA expression in two-thirds or more of patients: CK4 was decreased in 83% of patients, TGM3 in 77%, ECM1 in 73%, and PPL and EVPL in 67% each. In subset analyses, associations with age (for COL7A1), family history (for PPL and ECM1), and alcohol use (for SPARC and Fascin) were also noted. CONCLUSION: These data indicate that these nine genes have consistent differential mRNA expression, validating results of our previous cDNA array results, and affirming their potential role in the early detection of ESCC
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