Colloidal PbS Quantum Dot Photodiode Imager with Suppressed Dark Current.

Lead sulfide (PbS) colloidal quantum dots (CQDs) for photodetectors (PDs) have garnered great attention due to their potential use as low-cost, high-performance, and large-area infrared focal plane arrays. The prevailing device architecture employed for PbS CQD PDs is the p-i-n structure, where PbS CQD films treated with thiol molecules, such as 1,2-ethanedithiol (EDT), are widely used as p-type layers due to their favorable band alignment. However, PbS-EDT films face a critical challenge associated with low film quality, resulting in many defects that curtail the device performance. Herein, a controlled oxidization process is developed for better surface passivation of the PbS-EDT transport layer. The dark current density (Jd) of PbS CQD PDs based on optimized PbS-EDT layer shows a dramatic decrease by nearly 2 orders of magnitude. The increase of carrier lifetime and suppression of carrier recombination via controlled oxidation in PbS-EDT CQDs were confirmed by transient absorption spectra and electrochemical impedance spectra. The device based on the optimized PbS-EDT hole transport layer (HTL) exhibits a specific detectivity (D*) that is 3.4 times higher compared to the control device. Finally, the CQD PD employing oxidization PbS-EDT CQDs is integrated with a thin film transistor (TFT) readout circuit, which successfully accomplishes material discrimination imaging, material occlusion imaging, and smoke penetration imaging. The controlled oxidization strategy verifies the significance of surface management of CQD solids and is expected to help advance infrared optoelectronic applications based on CQDs.

Fluoride passivation of ZnO electron transport layers for efficient PbSe colloidal quantum dot photovoltaics.

Lead selenide (PbSe) colloidal quantum dots (CQDs) are suitable for the development of the next-generation of photovoltaics (PVs) because of efficient multiple-exciton generation and strong charge coupling ability. To date, the reported high-efficient PbSe CQD PVs use spin-coated zinc oxide (ZnO) as the electron transport layer (ETL). However, it is found that the surface defects of ZnO present a difficulty in completion of passivation, and this impedes the continuous progress of devices. To address this disadvantage, fluoride (F) anions are employed for the surface passivation of ZnO through a chemical bath deposition method (CBD). The F-passivated ZnO ETL possesses decreased densities of oxygen vacancy and a favorable band alignment. Benefiting from these improvements, PbSe CQD PVs report an efficiency of 10.04%, comparatively 9.4% higher than that of devices using sol-gel (SG) ZnO as ETL. We are optimistic that this interface passivation strategy has great potential in the development of solution-processed CQD optoelectronic devices.

The practice of reaction window in an electrocatalytic on-chip microcell.

To enhance the efficiency of catalysis, it is crucial to comprehend the behavior of individual nanowires/nanosheets. A developed on-chip microcell facilitates this study by creating a reaction window that exposes the catalyst region of interest. However, this technology's potential application is limited due to frequently-observed variations in data between different cells. In this study, we identify a conductance problem in the reaction windows of non-metallic catalysts as the cause of this issue. We investigate this problem using in-situ electronic/electrochemical measurements and atom-thin nanosheets as model catalysts. Our findings show that a full-open window, which exposes the entire catalyst channel, allows for efficient modulation of conductance, which is ten times higher than a half-open window. This often-overlooked factor has the potential to significantly improve the conductivity of non-metallic catalysts during the reaction process. After examining tens of cells, we develop a vertical microcell strategy to eliminate the conductance issue and enhance measurement reproducibility. Our study offers guidelines for conducting reliable microcell measurements on non-metallic single nanowire/nanosheet catalysts.

High-Pressure Synthesis of Single-Crystalline SnS Nanoribbons.

Two-dimensional tin monosulfide (SnS) is attractive for the development of electronic and optoelectronic devices with anisotropic characteristics. However, its shape-controlled synthesis with an atomic thickness and high quality remains challenging. Here, we show that highly crystalline SnS nanoribbons can be produced via high-pressure (0.5 GPa) and thermal treatment (400 °C). These SnS nanoribbons have a length of several tens of micrometers and a thickness down to 5.8 nm, giving an average aspect ratio of ∼30.6. The crystal orientation along the zigzag direction and the in-plane structural anisotropy of the SnS nanoribbons are identified by transmission electron microscopy and polarized Raman spectroscopy, respectively. An ionic liquid-gated field-effect transistor fabricated using the SnS nanoribbon exhibits an on/off current ratio of >103 and a field-effect mobility of ∼0.7 cm2 V-1 s-1. This work provides a unique way to achieve one-dimensional growth of SnS.

Cation-Exchange Enables In Situ Preparation of PbSe Quantum Dot Ink for High Performance Solar Cells.

Lead selenide (PbSe) colloidal quantum dots (CQDs) are promising candidates for optoelectronic applications. To date, PbSe CQDs capped by halide ligands exhibit improved stability and solar cells using these CQDs as active layers have reported a remarkable power conversion efficiency (PCE) up to 10%. However, PbSe CQDs are more prone to oxidation, requiring delicate control over their processability and compromising their applications. Herein, an efficient strategy that addresses this issue by an in situ cation-exchange process is reported. This is achieved by a two-phase ligand exchange process where PbI2 serves as both a passivating ligand and cation-source inducing transformation of CdSe to PbSe. The defect density and carrier lifetime of PbSe CQD films are improved to 1.05 × 1016  cm-3 and 12.2 ns, whereas the traditional PbSe CQD films possess 1.9 × 1016  cm-3 defect density and 10.2 ns carrier lifetime. These improvements are translated into an enhancement of photovoltaic performance of PbSe solar cells, with a PCE of up to 11.6%, ≈10% higher than the previous record. Notably, the approach enables greatly improved stability and a two-month stability is successfully demonstrated. This strategy is expected to promote the fast development of PbSe CQD applications in low-cost and high-performance optoelectronic devices.

Meigs' syndrome caused by granulosa cell tumor accompanied with intrathoracic lesions: A case report.

BACKGROUND: Meigs' syndrome is regarded as a benign ovarian tumor accompanied by pleural effusion and ascites, both of which resolve after removal of the tumor. Patients often seek treatment in the Department of Respiratory and Critical Care Medicine or other internal medicine departments due to symptoms caused by ascites or hydrothorax. Here, we report a rare case of Meigs' syndrome caused by granulosa cell tumor accompanied with intrathoracic lesions. CASE SUMMARY: A 52-year-old women was admitted to the Department of Respiratory and Critical Care Medicine due to coughing and expectoration accompanied with shortness of breath. Chest X-ray and chest computed tomography showed a modest volume of pleural fluid with pleural thickening in the right lung. The carbohydrate antigen 125 (CA125) concentration was 150.8 U/mL (normal, 0-35 U/mL) and no tumor cells were observed in pleural fluid. Nodules and a neoplasm with a fish meat-like appearance in the parietal pleura and nodules with a 'string of beads'-like appearance in the diaphragm were found by thoracoscopic examination. Furthermore, pelvic magnetic resonance revealed a pelvic mass measuring about 11.6 cm × 10.0 cm × 12.4 cm with heterogeneous signal intensity and multiple hypointense separations. Total abdominal hysterectomy, bilateral adnexectomy, and separation of pelvic adhesion were performed under general anesthesia. The pathology results showed granulosa cell tumor. At the 2-mo follow-up after the surgery, the hydrothorax subsided, and the CA125 level returned to normal. CONCLUSION: For postmenopausal women with unexplained hydrothorax and elevated CA125, in addition to being suspected of having gynecological malignancy, Meigs' syndrome should be considered.

The heterogeneous effects of urbanization and income inequality on CO2 emissions in BRICS economies: evidence from panel quantile regression.

This paper empirically examines the effects of urbanization and income inequality on CO2 emissions in the BRICS economies (i.e., Brazil, Russia, India, China, and South Africa) during the periods 1994-2013. The method we used is the panel quantile regression, which takes into account the unobserved individual heterogeneity and distributional heterogeneity. Our empirical results indicate that urbanization has a significant and negative impact on carbon emissions, except in the 80th, 90th, and 95th quantiles. We also quantitatively investigate the direct and indirect effect of urbanization on carbon emissions, and the results show that we may underestimate urbanization's effect on carbon emissions if we ignore its indirect effect. In addition, in middle- and high-emission countries, income inequality has a significant and positive impact on carbon emissions. The results of our study indicate that in the BRICS economies, there is an inverted U-shaped environmental Kuznets curve (EKC) between the GDP per capita and carbon emissions. The conclusions of this study have important policy implications for policymakers. Policymakers should try to narrow the income gap between the rich and the poor to improve environmental quality; the BRICS economies can speed up urbanization to reduce carbon emissions, but they must improve energy efficiency and use clean energy to the greatest extent in the process.

Combined prolapse and midurethral sling surgery versus prolapse surgery for women with pelvic organ prolapse and stress urinary incontinence:a Meta-analysis / 中国基层医药

Objective To systematically review the efficacy and safety of prolapse surgery versus combined prolapse and midurethral sling surgery in women with pelvic organ prolapse and stress urinary incontinence.Methods Databases including PubMed,EMbase,the Cochrane Library(Issue 7,2016),Web of Knowledge,CNKI,CBM,WanFang Data and VIP were searched from inception to July 31th 2016,to collect randomized controlled trial(RCT) of combined prolapse and midurethral sling surgery versus prolapse surgery for pelvic organ prolapse and stress urinary incontinence.Two reviewers independently screened literature,extracted data and assessed the risk of bias of included studies.Then,meta-analysis was performed using RevMan 5.3 software.Results A total of 4 RCT involving 446 patients were included.The results of meta-analysis showed that,for postoperative outcomes,compared with prolapse surgery,the incidence of urinary incontinence,stress urinary incontinence,urgency urinary incontinence,any treatment for SUI,surgery for stress urinary incontinence[RR=0.57,95%CI(0.46~0.70),P<0.000;RR=0.24,95%CI(0.10~0.60),P=0.002;RR=0.58,95%CI(0.39~0.85,P=0.006;RR=0.20,95%CI(0.06~0.67),P=0.009;RR=0.07,95%CI(0.01~0.56),P=0.010]were lower in combined prolapse and midurethral sling surgery.For complications,the incidence of bladder perforation or injury,urinary tract infection,incomplete bladder emptying at 1 week[RR=9.72,95%CI(1.78~53.01),P=0.009;RR=1.77,95%CI(1.23~2.54),P=0.002;RR=1.39,95%CI(1.06~1.81),P=0.020]were higher in combined prolapse and midurethral sling surgery,while there were no statistical differences between the two groups in the incidence of voiding dysfunction,vaginal tape erosion,major bleeding or vascular complication.Conclusion For women with pelvic organ prolapse and stress urinary incontinence,compared to prolapse surgery,the incidence of urinary incontinence and treatment of urinary incontinence is lower in combined prolapse and midurethral sling surgery,the incidence of partial complications is higher in combined prolapse and midurethral sling surgery.Due to the limited quality and quantity of the included studies,more high quality studies are needed to verify the above conclusion.

[Contributions of Factors That Influenced the Visibility In North Suburb of Nanjing In Winter and Spring].

The data of visibility, relative humidity (RH), temperature (T), concentrations and chemical compositions of particles from January to May in 2014 were analyzed to understand the effects of meteorological elements and aerosols on the visibility in north suburb of Nanjing, research the contributions of different aerosol chemical compositions to extinction coefficients and propose the visibility fitting solutions of this region based on different parameters. As the results showed, the average visibility during the observation period was (5.78 ± 3.64) km; there were obvious negative correlations between visibility and RH, PM2.5 and the correlation coefficients were -0.66 and -0.48, respectively. The average extinction coefficient in winter was (398.72 ± 219.88) Mm⁻¹, the contributions of Organic, NH4NO3, (NH4)2SO4 and EC to extinction coefficient were 38.81%, 27.81%, 23.95% and 7.15%, respectively; and the average extinction coefficient in spring was (248.36 ± 78.42) Mm⁻¹, the contributions of Organic, NH4NO3, (NH4) 2SO4 and EC to extinction coefficient were 31.59%, 24.36%, 32.63% and 8.64%, respectively. The visibility fitting solution based on chemical compositions of aerosols was better than that based on extinction coefficient when comparing the different fitting solutions. The levels of PM2.5 mass concentrations' influences on the visibility depended on different ranges of RH; the visibility fitting solutions based on PM2.5, RH and T explained that the effects of PM2.5 on visibility were strong when RH stayed low, while RH became the more important factor with its increase.

[Hygroscopic Properties and Closure of Aerosol Chemical Composition in Mt. Huang in Summer].

The hygroscopic properties of aerosol have significant impact on aerosol optical properties, cloud condensation nuclei activity and human health. Aerosol particles growth factor and size-resolved ions chemical compositions were monitored in Mt. Huang. The hygroscopic properties of aerosol particles in Mt. Huang were studied. The results demonstrated that between 70 nm and 230 nm, the mass fractions of (NH4)2SO4, organic matter and other insoluble materials were the highest. The fraction of NH4NO3 standed in the medium. The fraction of NH4HSO4 was the lowest. The fraction of inorganic salts increased with increasing particle diameter. Aerosol particles during daytime had stronger hygroscopicity than that at night and the hygroscopicity of aerosol became stronger when its diameter increased. The calculation hygroscopic parameter κ of aerosol particles showed similar diurnal variation characteristics to the observation κ. Good closure could be achieved when ZSR mixing rule was used based on aerosol chemical composition to calculate aerosol hygroscopic parameter κ and the coefficient of determination was 0.60 for all the diameters.

[Effects of Relative Humidity and Aerosol Physicochemical Properties on Atmospheric Visibility in Northern Suburb of Nanjing].

To understand the effects of relative humidity (RH) and aerosol physicochemical properties on the atmospheric visibility in autumn and winter in northern suburb of Nanjing, the relationships between meteorological elements, particulate matter and visibility were analyzed with the data of meteorological elements, aerosol particle spectra, particulate matter concentration and chemical composition. The average visibility was 4.76 km in autumn and winter in northern suburb of Nanjing. There was a certain negative correlation between the particulate matter concentration and the visibility, especially the influence of fine particles on the visibility was more remarkable. The occurrence frequencies of low visibilities showed an increasing trend with the increasing concentration of fine particles and RH. When the visibility decreased from 5-10 km to <5 km, the mass concentrations of PM10 and PM2.5 increased by 7.56% and 37.64%, respectively. Meanwhile, the mass concentrations of SO4(2-) and NO3-increased significantly. Effects of aerosol particle number concentration on the visibility were related with RH. Aerosol number concentration with diameters ranging from 0.5 microm to 2 microm increased slowly with the increase of RH, while those ranging from 2 microm to 10 microm decreased. The correlation analysis between the aerosol surface area concentration and the visibility showed that RH and fine particles between 0.5 microm and 2 microm were the main factors which caused the decrease of atmospheric visibility in autumn and winter in northern suburb of Nanjing.