Slow Auger Recombination of Trapped Excitons Enables Efficient Multiple Electron Transfer in CdS–Pt Nanorod Heterostructures

Solar-to-fuel conversion reaction often requires multiple proton-coupled electron transfer (PCET) processes powered by the energetic electrons and/or holes generated by the absorption of multiple photons. The effective coupling of multiple electron transfer from the light absorber with the multiple PCET reactions at the catalytic center is one of the key challenges in efficient and selective conversion of solar energy to chemical fuels. In this paper, we examine the dynamics of multiple electron transfer in quantum confined CdS nanorods with a Pt tip, in which the CdS rod functions as the light absorber and the Pt tip the catalytic center. By excitation-fluence-dependent transient absorption spectroscopic measurements, we show that the multiexciton Auger recombination rate in CdS rods follows a carrier-collision model, knA = n2(n – 1)/4k2A, with a biexciton lifetime (1/k2A) of 2.0 ± 0.2 ns. In CdS–Pt nanorods, electron transfer kinetics from the CdS conduction band edge to the Pt show negligible dependence on the excitation fluence, occurring with a half-life time of 5.6 ± 0.6 ps. The efficiency of multiple exciton dissociation by multiple electron transfer to Pt decreases from 100% in biexciton states to ∼41% at 22 exciton state due to the competition with Auger recombination. The half-lifetime of the n-charge separated state recombination (with n electrons in the Pt and n holes in the CdS) decreases from 10 μs in the single charge separated state to 42 ns in nine charge separated states. Our findings suggest the possibility of driving multielectron photocatalytic reactions under intense illumination and controlling product selectivity through multielectron transfer

Does flattening the government hierarchy improve corporate innovation? Evidence from China

We examine the impact of flattening the government hierarchy on corporate innovation. Leveraging the change from province–city–county to province–managing–county (PMC) administrative structures in China, we use a different-in-differences research design to show that the PMC reform enhances corporate innovation. The results are robust to a battery of checks. We report that political connection, state-ownership of firms and improved government services mediate the effects of the PMC reform on corporate innovation. Moreover, in the cross-sectional analysis, we find that the impact of the PMC reform is more salient for non-state-owned firms or when a province has new leadership.</p

Selective Fluorescence Detection of Cysteine over Homocysteine and Glutathione Based on a Cysteine-Triggered Dual Michael Addition/Retro-aza-aldol Cascade Reaction

In this work, a cysteine (Cys)-triggered dual Michael addition/retro-aza-aldol cascade reaction has been exploited and utilized to construct a fluorescent probe for Cys for the first time. The resulting fluorescent probe 8-alkynylBodipy <b>1</b> contains an activated alkynyl unit as Michael receptor and a Bodipy dye as fluorescence reporter and can highly selectively detect Cys over homocysteine (Hcy)/glutathione (GSH) as well as other amino acids with a significant fluorescence off–on response (∼4500-fold) and an ultralow detection limit (0.38 nM). The high selectivity of <b>1</b> for Cys could be attributed to a kinetically favored five-membered cyclic intermediate produced by the dual Michael addition of Cys with the activated alkynyl unit of <b>1</b>. The big fluorescence off–on response is due to the subsequent retro-aza-aldol reaction of the five-membered cyclic intermediate that results in the release of a highly fluorescent 8-methylBodipy dye <b>2</b>. The probe has been successfully used to detect and image Cys in serum and cells, respectively

Study selection diagram.

<p>Study selection diagram.</p

Overexpression of Rho GDP-Dissociation Inhibitor Alpha Is Associated with Tumor Progression and Poor Prognosis of Colorectal Cancer

The GDP dissociation inhibitors (GDIs) are pivotal regulators of Rho GTPases, which are essential for tumor progression, particularly in the area of metastasis. One member of GDIs was identified as RhoGDI (Rho GDP-dissociation inhibitor alpha, or RhoGDIα), but little is known about this protein in tumors. In this study, we used comparative proteomic analysis to show that RhoGDI is markedly up-regulated in metastatic colorectal cancer (CRC). The elevated level of RhoGDI protein in metastatic CRC was confirmed by Western blot at the tissue (n = 24) and cell (n = 6) levels. Further, we analyzed RhoGDI protein expression in 126 clinicopathologically characterized CRC cases by immunohistochemistry. Statistical analysis showed that there were significant differences of RhoGDI overexpression in patients categorized according to tumor invasion (p = 0.018), lymph node metastasis (p = 0.001) and clinical stage (p = 0.009). A trend was also identified between high expression of RhoGDI and shorter overall survival (p = 0.013). In the present work, we also analyzed the effect of RhoGDI on CRC cell line. Gene transfection-mediated overexpression of RhoGDI in HT29 cells, containing a low detectable level of endogenous RhoGDI, resulted in a significant increase in cell proliferation and motility in vitro. These data suggest that RhoGDI may promote CRC progression and metastasis by stimulating tumor cell growth and migration

Forest plot of risk ratios and 95% confidence intervals (CI) for the incidence of contrast induced nephropathy among patients assigned to statin therapy versus control.

<p>Forest plot of risk ratios and 95% confidence intervals (CI) for the incidence of contrast induced nephropathy among patients assigned to statin therapy versus control.</p

Quality of included RCTs.

<p> <b>NS = not specified or available.</b></p

Characteristics of included studies-continued.

<p>Statin = statin-treated group (high-dose);Control = control group (low-dose or non-statin);CAG = coronary angiography;PCI = percutaneous coronary intervention;CrCl = creatinine clearance;Scr = serum creatinine;CRP = C-reactive protein;eGFR = estimated glomerular filtration rate;NAC = N-acetylcysteine;NS = 0.9% sodium chloride; NS = not specified or available.</p

Funnel plot with 95% confidence intervals (CI) to assess for evidence of publication bias.

<p>Funnel plot with 95% confidence intervals (CI) to assess for evidence of publication bias.</p

Forest plot of risk ratios and 95% confidence intervals (CI) for the incidence of CIN among patients assigned to short-term high-dose statin treatment versus low-dose or non-statin.

<p>Forest plot of risk ratios and 95% confidence intervals (CI) for the incidence of CIN among patients assigned to short-term high-dose statin treatment versus low-dose or non-statin.</p