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Objectives To compare the available evidence of the effectiveness of single blastocyst stage transfer against the effectiveness of single cleavage stage embryo transfer. Study design A systematic research based on Pubmed, Embase and the Cochrane Library was performed until May 2, 2020 to identify all relevant studies. The Cochrane Collaboration’s Review Manager (RevMan) 5.0.2 software was used for statistical analysis. Results Five randomized controlled trials (RCTs) were included in analysis, involving 1784 patients in total, who were divided into 2 groups, which were the single blastocyst stage transfer (SBT) group of 932, and the single cleavage stage transfer (SCT) group of 852. Our meta-analysis concluded that SBT group had a significantly higher clinical pregnancy rate (RR 1.26; 95%CI: 1.14–1.39), ongoing pregnancy rate (RR 1.19; 95%CI: 1.05–1.35) and delivery rate (RR 1.4; 95%CI: 1.13–1.75) than SCT group during the fresh transfer. While miscarriage rate (RR 0.93; 95% CI: 0.66–1.33), multiple pregnancy rate (RR, 1.12; 95% CI, 0.51–2.45) and ectopic pregnancy rate (RR, 0.5; 95% CI: 0.13–1.90) between two groups showed no significant difference. However, the SCT group contained notably more cryopreserved embryos than the SBT group. (RR −0.68, 95% CI: −0.95 to −0.41). Conclusions Our results indicate that single blastocyst stage transfer is associated with higher ongoing pregnancy rate and delivery rate comparing to single cleavage stage transfer in the clinical practice. Due to the low quality of the evidence of the primary outcomes, other higher-quality lager RCTs are necessary before a fully informed decision is made.

As coal mining is extended from shallow to deep areas along the western coalfield, it is of great significance to study weakly cemented sandstone at different depths for underground mining engineering. Sandstones from depths of 101.5, 203.2, 317.3, 406.9, 509.9 and 589.8 m at the Buertai Coal Mine were collected. The characteristic strength, acoustic emission (AE), and energy evolution of sandstone during uniaxial compression tests were analyzed. The results show that the intermediate frequency (125–275 kHz) of shallow rock mainly occurs in the postpeak stage, while deep rock occurs in the prepeak stage. The initiation strength and damage strength of the sandstone at different depths range from 0.23 to 0.50 and 0.63 to 0.84 of peak strength (σc), respectively, decrease exponentially and are a power function with depth. The precursor strength ranges from 0.88σc to 0.99σc, increases with depth before reaching a depth of 300 m, and tends to stabilize after 300 m. The ratio of the initiation strength to the damage strength (k) ranges from 0.25 to 0.62 and decreases exponentially with depth. The failure modes of sandstone at different depths are tension-dominated mixed tensile-shear failure. Shear failure mainly occurs at the unstable crack propagation stage. The count of the shear failure bands before the peak strength increases gradually, and increases first and then decreases after the peak strength with burial depth. The cumulative input energy, released elastic energy and dissipated energy increase with depth. The elastic release rate ranges from 0.46 × 10–3 to 198.57 × 10–3 J/(cm3 s) and increases exponentially with depth.

Background The efficacy of levofloxacin and ciprofloxacin in the treatment of urinary tract infection is not clear yet. This study perform a meta-analysis to explore the differences between the two against urinary tract infection (UTI). Methods A computerized literature search was conducted of the databases of PubMed, Medline, Embase, and the Cochrane Library. All the retrieved literatures were randomized comparative studies of levofloxacin and ciprofloxacin. The included studies were screened according to the standard of nanofiltration. The risk of bias was assessed with RevMan 5.3.5 software. The treatment effect index and incidence of adverse reactions index were established and compared via meta-analysis. Results A total of 5 studies were included, involving 2,877 patients overall. The results showed that levofloxacin was more effective than ciprofloxacin, but the difference between the 2 drugs was not statistically significant [odds ratio (OR) =1.18, 95% confidence interval (CI): 0.94 to 1.46, P=0.15]. There was also no statistical significance in the rate of adverse reactions between the 2 drugs (OR =0.91, 95% CI: 0.78 to 1.07, P=0.27). Discussion In the treatment of UTI, the efficacy and safety of levofloxacin and ciprofloxacin are similar statistically. If bacterial resistance is discovered after the treatment of one of the drugs, the other drug might become an alternative.

Background This study explored the relevance between rs1695 and susceptibility to the lung cancer in the Chinese Han population. Stratification analysis was conducted on the basis of age, gender, smoking status, tumor-related family history, and pathological type to observe relations between rs1695 and susceptibility to lung cancer in the subgroups. Methods A case-control study was performed with 974 lung cancer patients who were pathologically diagnosed and 1005 healthy cases based on physical examination to analyze the association between rs1695 and the risk of lung cancer. Results The frequencies of the AA, GA, and GG genotypes of rs1695 were 68.4%, 28.7%, and 2.9% in cases and 64.8%, 30.8%, and 4.2% in controls, respectively. After adjustment for age, gender, smoking status, and family history, it appears that the rs1695 G allele decreases the risk of lung cancer (OR = 0.811, 95% CI 0.684–0.961, P = 0.016). Moreover, compared with the AA genotype, the GA + GG genotype decreased lung cancer susceptibility (OR = 0.808, 95% CI 0.663–0.985, P = 0.035) and the GG genotype (OR = 0.591, 95% CI 0.347–0.988, P = 0.048). In a stratified analysis, the risk of lung cancer in the G allele carriers decreased among the males, patients without a tumor-related family history, and patients with lung adenocarcinoma, especially in smokers. Conclusion The polymorphism of locus rs1695 is related to the risk of lung cancer and is expected to be a target for the prediction of lung cancer.

Introduction: The aim of this study was to investigate the sexual intercourse frequency (SIF) of infertile couples without sexual dysfunction and analyze its related influencing factors. Materials and Methods: We retrospectively analyzed the data of a total number of 4,923 infertile couples without sexual dysfunction who received treatment in our assisted reproductive center from October 2016 to October 2018. Both partners of couples were inquired about their information of demographic statistics, occupations, lifestyles, education backgrounds, psychological characteristics, and testostrone levels of male patients. The multivariable linear regression analysis was applied to evaluate the influence of various variables on SIF. Results: The median (interquartile range) SIF of infertile couples without sexual dysfunction was 7 (6.5–8) times per month. Lower academic qualification and younger age were predictive of increased SIF in both partners. The SIF of Chinese Han women and Chinese Zang women is higher than that of other ethnic groups. Men with lower testosterone (Conclusion: In our study, we analyzed demographics data, occupational characteristics, and lifestyle behaviors of both partners, as well as men’s testosterone levels; we also reported the related SIF. According to our research, men’s education level was the most important factor in predicting SIF, followed by men’s age. Testosterone levels of men do not appear to play a substantial role in predicting SIF in infertile couples.

Coal mass strength estimation has attracted broad attentions for decades. Investigating the effect of scale and anisotropy on the Uniaxial Compressive Strength (UCS) estimation via P-wave velocity ...

We examine the relation between borrowing firms’ corporate political transparency and the cost of debt. Using a sample of S&P 500 firms over the 2012–2016 period, we document a significant negative association between firms’ corporate political transparency and their cost of debt. We also find that the negative association is more pronounced when the borrowing firms are in less unionized industries and have younger executives (CEOs or board of directors). Our results are robust to a variety of sensitivity tests.

In this article, we fabricate a flexible pressure sensor based on the honeycomb-like graphene network (HGN). The HGN is fabricated by mixing cube sugar, graphene oxide solution, and polydimethylsiloxane. Attributing to the structure, the pressure sensor shows a high sensitivity of 3.54 kPa−1 in the low-pressure regime (

BackgroundThe 5-year survival rate of patients with lung cancer in China is less than 20% and predicting their prognosis is challenging. We investigated the association between a common non-synonymous single nucleotide polymorphism (SNP), rs7214723, in the Ca2+/calmodulin-dependent protein kinase kinase 1 (CAMKK1) gene and the prognosis of patients with lung cancer.MethodsGenomic DNA was extracted from the blood samples of 839 patients with lung cancer, recruited from Changhai Hospital (n = 536) and Taizhou Institute of Health Sciences (n = 352), and genotyped using the SNPscan technique. The association between patient prognosis and the genotypic data for CAMKK1 was analyzed using a multivariate Cox proportional hazards model adjusted for multiple potential confounders. The CRISPR/Cas9 gene-editing system was used to introduce point mutations in the CAMKK1 rs7214723 of A549 and NCI-H358 cells. Subsequently, Cell proliferation and migration ability were assessed with the Cell Counting Kit-8 and scratch assay. The Annexin V-FITC apoptosis detection kit was used to detect cell apoptosis.ResultsThe CAMKK1 rs7214723 recessive CC genotype conferred significantly better overall survival (CC vs. TT + TC: adjusted hazard ratio = 0.78, 95% confidence interval [CI], 0.61-1.00, P = 0.049) than the TT + TC genotypes. Stratified analysis showed that the CAMKK1 rs7214723 CC genotype and recessive CC genotype conferred a significantly decreased risk of death in patients who were male, had a smoking history, or had stage III + IV cancer, compared with the TT and TT + TC genotypes. Relative to the TT + TC genotypes, the rs7214723 recessive CC genotype was also associated with a decreased risk of death in patients aged < 60 years (CC vs. TT + TC: adjusted hazard ratio = 0.59, 95% CI, 0.37-0.93, P = 0.024) and patients with squamous cell carcinoma (CC vs. TT + TC: adjusted hazard ratio = 0.65, 95% CI, 0.44-0.98, P = 0.038). Remarkably, CRISPR/Cas9-guided single nucleotide editing demonstrated that CAMKK1 rs7214723 T > C mutation significantly inhibits cell proliferation and migration and promotes cell apoptosis.ConclusionsCAMKK1 SNP rs7214723 may be a significant prognostic factor for the risk of death among patients with lung cancer.

Using the recognition of the Inevitable Disclosure Doctrine (IDD) by US state courts as an exogenous shock to the risk of losing trade secrets, this study examines the effects of trade secrets on disclosure of forward‐looking financial information. We find that management earnings forecast frequency and forecast horizon increases after the US state where a firm is headquartered starts to recognize IDD. We also find that the effect of IDD recognition on management forecasts is more pronounced for firms that have larger market shares, higher product market competition, more intensive R&D, shorter distance to their industry rivals, and more employees who possess knowledge of the firms’ trade secrets.

In this work, a thin-film transistor gas sensor based on the p-N heterojunction is fabricated by stacking chemical vapor deposition-grown tungsten disulfide (WS2) with a sputtered indium–gallium–zi...

Two-dimensional (2D) hybrid perovskite sandwiched between two long-chain organic layers is an emerging class of low-cost semiconductor materials with unique optical properties and improved moisture stability. Unlike conventional semiconductors, ion migration in perovskite is a unique phenomenon possibly responsible for long carrier lifetime, current–voltage hysteresis, and low-frequency giant dielectric response. While there are many studies of ion migration in bulk hybrid perovskite, not much is known for its 2D counterparts, especially for ion migration induced by light excitation. Here, we construct an exfoliated 2D perovskite/carbon nanotube (CNT) heterostructure field effect transistor (FET), not only to demonstrate its potential in photomemory applications, but also to study the light induced ion migration mechanisms. We show that the FET I–V characteristic curve can be regulated by light and shows two opposite trends under different CNT oxygen doping conditions. Our temperature-dependent study indicates that the change in the I–V curve is probably caused by ion redistribution in the 2D hybrid perovskite. The first principle calculation shows the reduction of the migration barrier of I vacancy under light excitation. The device simulation shows that the increase of 2D hybrid perovskite dielectric constant (enabled by the increased ion migration) can change the I–V curve in the trends observed experimentally. Finally, the so synthesized FET shows the multilevel photomemory function. Our work shows that not only we could understand the unique ion migration behavior in 2D hybrid perovskite, it might also be used for many future memory function related applications not realizable in traditional semiconductors., A two-dimensional perovskite/carbon nanotube heterostructure was constructed not only to study light induced ion migration mechanisms, but also to demonstrate its potential in photomemory applications.

MXenes have attracted great attention for their potential applications in electrochemical and electronic devices due to their excellent characteristics. Traditional sound sources based on the thermoacoustic effect demonstrated that a conductor needs to have an extremely low heat capacity and high thermal conductivity. Hence, a thin MXene film with a low heat capacity per unit area (HCPUA) and special layered structure is emerging as a promising candidate to build loudspeakers. However, the use of MXenes in a sound source device has not been explored. Herein, we have successfully prepared sound source devices on an anodic aluminum oxide (AAO) and a flexible polyimide (PI) substrates by using the prepared Ti3C2 MXene nanoflakes. Due to the larger interlayer distance of MXene, the MXene-based sound source device has a higher sound pressure level (SPL) than that of graphene of the same thickness. High-quality Ti3C2 MXene nanoflakes were fabricated by selectively etching the Ti3AlC2 powder. The as-fabricated MXene sound source device on an AAO substrate exhibits a higher SPL of 68.2 dB (f = 15 kHz) and has a very stable sound spectrum output with frequency varying from 100 Hz to 20 kHz. A theoretical model has been built to explain the mechanism of the sound source device on an AAO substrate, matching well with the experimental results. Furthermore, the MXene sound source device based on a flexible PI substrate has been attached to the arms, back of the hand, and fingers, indicating an excellent acoustic wearability. Then, the MXene film is packaged successfully into a commercial earphone case and shows an excellent performance at high frequencies, which is very suitable for human audio equipment.

Among two-dimensional layered semiconductors, indium selenide (InSe) is one of the most promising materials with absolute advantages in field-effect transistors (FETs) because of its high electron mobility and stable material properties. Some work has been performed to improve the mobility of InSe FETs. However, in practical applications, electrical stability of FETs is another essential factor to guarantee the performance of the electronic system. Here, we show a highly stable InSe FET with a field-effect mobility of 1200 cm2/V·s in the practical working regime. The bottom-gate staggered InSe FET was fabricated with a polymethyl methacrylate (PMMA)/HfO2 dual-layer gate dielectric and PMMA back-channel encapsulation. The hysteresis was maintained at 0.4 V after 30 days of storage under normal ambient conditions, and the threshold voltage shift was retained at 0.6 V with a gate stress VGS of 10 V, which represents the best electrical stability reported to date. Its high mobility and electrical stability enable reliable detection of the weak nerve action potential at a low power consumption. High-performance InSe FETs expand their promising applications in flexible and in situ real-time intelligent nerve action potential recording.

Background: Elabela (ELA) is a newly identified endogenous ligand of apelin receptor (APJ) which has been confirmed to be implicated in the pathogenesis of hypertension. Previous experiments have revealed the critical role of ELA in eliciting vasodilation and lowering blood pressure. However, the role of plasma ELA levels in hypertensive patients and its relationship with vascular function have not been investigated.Method: Thirty-one patients with essential hypertension (EH) and 31 age-matched healthy subjects as controls were recruited in the study. Plasma ELA concentration and vascular function parameters including brachial artery flow-mediated dilation (FMD) and brachial-ankle pulse wave velocity (baPWV) were measured.Results: We observed remarkably lower plasma ELA concentration in hypertensive patients as compared with controls (1.29 ± 0.56 ng/ml vs. 1.79 ± 0.55 ng/ml; P = 0.001). Linear correlation analysis showed that ELA was negatively correlated with systolic blood pressure (r = -0.388, P = 0.002) and diastolic blood pressure (r = -0.321, P = 0.011) and positively correlated with FMD (r = 0.319, P = 0.011). There was no statistically significant relationship between ELA and baPWV (r = 0.234, P = 0.067). Stepwise multiple linear analysis also identified a close association of plasma ELA levels with endothelial function.Conclusion: The present study demonstrates for the first time that circulating ELA levels are reduced in patients with EH. The fall in endogenous ELA levels may be involved in the pathogenesis of hypertension-related vascular damage.

The emergence of social media as a corporate disclosure channel has caused significant changes in the production and dissemination of corporate information. This review identifies important themes in recent research on the impact of social media on the corporate information environment and provides suggestions for further explorations of this new but fast-growing area of research. Specifically, we first review the evolution of Internet-based corporate disclosure and related regulations, and then focus on three recent streams of research: 1) companies’ use of social media; 2) information produced by non-corporate users and its impact on capital markets; and 3) the credibility of corporate information on social media platforms.

Purpose Lung cancer is the leading cause of cancer death worldwide, and the predominant risk factor for its development is smoking. Thymidylate synthase (TYMS) is a key enzyme in DNA synthesis that catalyzes the conversion of deoxyuridine monophosphate to dTMP. Rs931794, a single nucleotide polymorphism located in the TYMS gene, was suggested to be associated with cancer risk. Methods To analyze the interaction between rs3819102 and environmental factors on the risk of lung cancer in a Chinese population, single nucleotide polymorphismscan was used to genotype this polymorphism in 974 lung cancer cases and 1005 control subjects. Results The frequencies of TT, CT, and CC genotypes of TYMS rs3819102 were 61.8%, 32.9%, and 5.3% in controls, and 53.8%, 38.4%, and 7.8% in cases, respectively. Compared with the TT genotype, the CT (odds ratio [OR], 1.380; 95% confidence interval [CI], 1.131-1.683), and CC (OR, 1.786; 95% CI, 1.213-2.644) genotypes were associated with an increased risk of lung cancer after adjustment for age, gender, smoking status, and family history. The C allele of rs3819102 is the risk allele for lung carcinogenesis in a dominant model (OR, 1.435; 95% CI, 1.188-1.735). In a stratified analysis, the risk effects of both the CT and CC genotypes of rs3819102 were more evident in subgroups of smokers and people without a family history of cancer. Conclusion The rs3819102 polymorphism in TYMS might increase susceptibility to environmental factors and contribute to the risk of lung cancer. The C allele is a risk allele in lung carcinogenesis.

COVID-19 is a respiratory disease caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2). This paper proposes a deep learning model to assist medical imaging physicians in diagnosing COVID-19 cases. We designed the Parallel Channel Attention Feature Fusion Module (PCAF), and brand new structure of convolutional neural network MCFF-Net was put forward. The experimental results show that the overall accuracy of MCFF-Net66-Conv1-GAP model is 96.79% for 3-class classification. Simultaneously, the precision, recall, specificity and the sensitivity for COVID-19 are both 100%. Compared with the latest state-of-art methods, the experimental results of our proposed method indicate its uniqueness.

When light-matter polaritons travel in periodic media, they acquire properties akin to Bloch quasi-particles in crystals., Efficient control of photons is enabled by hybridizing light with matter. The resulting light-matter quasi-particles can be readily programmed by manipulating either their photonic or matter constituents. Here, we hybridized infrared photons with graphene Dirac electrons to form surface plasmon polaritons (SPPs) and uncovered a previously unexplored means to control SPPs in structures with periodically modulated carrier density. In these periodic structures, common SPPs with continuous dispersion are transformed into Bloch polaritons with attendant discrete bands separated by bandgaps. We explored directional Bloch polaritons and steered their propagation by dialing the proper gate voltage. Fourier analysis of the near-field images corroborates that this on-demand nano-optics functionality is rooted in the polaritonic band structure. Our programmable polaritonic platform paves the way for the much-sought benefits of on-the-chip photonic circuits.

Machine learning (ML) methods have shown promising results in identifying genes when applied to large transcriptome datasets. However, no attempt has been made to compare the performance of combining different ML methods together in the prediction of high feed efficiency (HFE) and low feed efficiency (LFE) animals. In this study, using RNA sequencing data of five tissues (adrenal gland, hypothalamus, liver, skeletal muscle, and pituitary) from nine HFE and nine LFE Nellore bulls, we evaluated the prediction accuracies of five analytical methods in classifying FE animals. These included two conventional methods for differential gene expression (DGE) analysis (t-test and edgeR) as benchmarks, and three ML methods: Random Forests (RFs), Extreme Gradient Boosting (XGBoost), and combination of both RF and XGBoost (RX). Utility of a subset of candidate genes selected from each method for classification of FE animals was assessed by support vector machine (SVM). Among all methods, the smallest subsets of genes (117) identified by RX outperformed those chosen by t-test, edgeR, RF, or XGBoost in classification accuracy of animals. Gene co-expression network analysis confirmed the interactivity existing among these genes and their relevance within the network related to their prediction ranking based on ML. The results demonstrate a great potential for applying a combination of ML methods to large transcriptome datasets to identify biologically important genes for accurately classifying FE animals.

COVID-19 is a respiratory disease caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2). Due to the rapid spread of COVID-19 around the world, the number of COVID-19 cases continues to increase, and lots of countries are facing tremendous pressure on both public and medical resources. Although RT-PCR is the most widely used detection technology with COVID-19 detection, it still has some limitations, such as high cost, being time-consuming, and having low sensitivity. According to the characteristics of chest X-ray (CXR) images, we design the Parallel Channel Attention Feature Fusion Module (PCAF), as well as a new structure of convolutional neural network MCFF-Net proposed based on PCAF. In order to improve the recognition efficiency, the network adopts 3 classifiers: 1-FC, GAP-FC, and Conv1-GAP. The experimental results show that the overall accuracy of MCFF-Net66-Conv1-GAP model is 94.66% for 4-class classification. Simultaneously, the classification accuracy, precision, sensitivity, specificity, and F1-score of COVID-19 are 100%. MCFF-Net may not only assist clinicians in making appropriate decisions for COVID-19 diagnosis but also mitigate the lack of testing kits.

Both computed tomography (CT) and notched semicircular bend (NSCB) tests are performed for coals with high and medium bursting proneness to extract the scientific expression of pore-fracture and its influence mechanism on the tensile failure behavior. The acoustic emission (AE) parameters in the sample during loading and failure are monitored, and the influence mechanism of pore-fracture on tensile failure behavior of coal is analyzed. The result illustrates that the spatial distribution feature of the pore-fracture in coals with high and medium bursting proneness is extremely different. The deformation and failure mode of the coals are affected by many factors, loading mode, notch depth and width, mechanical properties of matrix and minal, spatial distribution feature of pore-fracture, etc. The influence of primary pore-fracture in the coal on the extension and penetration of the secondary fracture could be divided into two types: bifurcation and promotion, which would cause different local damage in the sample and affect the final failure mode. The feature of acoustic emission parameters indicates that the deformation and failure process of a sample under loading could be divided into four stages: compaction stage, elastic deformation stage, displacement plastic growth stage, and post peak failure stage, which is the result of comprehensive action of many factors. The evolution process of secondary fracture is accompanied by the dissipation of elastic strain energy and the intensification of internal damage of coal, which reflects the failure process of coal.

Recently, soft electrothermal actuators have attracted tremendous attentions. Large deformation under low driving voltage has long been the design concerns for scholars. However, in practice, apart from larger deformation, higher requirements are put forward for higher deformation speed in repeated cycles to achieve efficient and agile actuation. Herein, a soft electrothermal actuator is fabricated based on laser reduced graphene oxide and silver nanowire composite with polydimethylsiloxane substrate, which completely realizes the above required advantages. Besides, a concept of periodic curvature rate is proposed to accurately evaluate the deformation speed, which is more normalized than time alone to reflect before. The soft electrothermal actuator here can achieve a large curvature of 2.5 cm-1 with a high periodic curvature rate of up to 8.93×10-2 cm-1/s under low power density input of 0.8W•cm-2 (driving voltage of 28V), which shows obvious advantages in both deformation quantity and speed compared with most reported electrothermal actuators till now. Finally, a bionic hand consisting of five U-shaped electrothermal actuators is demonstrated to achieve gesture following and restoring, showing its promising prospects in the emerging bionics field.

An ultraviolet (UV) photodetector based on hydrothermally processed ZnO nanorods (ZnO NRs) decorated by gold nanoparticles (Au NPs) was demonstrated to exhibit extraordinary optoelectronic properties. Due the implementation of Au NPs, the UV responsivity and specific detectivity reached 70 A/W and 3.41 $\times$ 1012 cm Hz1/2 W−1, respectively, which were enhanced by approximately four times at an excitation wavelength of 365 nm compared with those of pristine ZnO NRs. Moreover, such photodetector shows good flexibility as well due to the mica substrate, which maintains almost constant performances under different bending radii of curvature and repeatable bending test more than 200 cycles. The photodetector also exhibits good transparency, giving it the potential of integration with other light photodetectors. In addition, a schematic band-diagram and the accompanying finite-difference time-domain analysis were performed to reveal the electron transfer and electric field distribution of ZnO NRs decorated with Au NPs. Our results revealed that the noble metal modified plasmon-enhanced ZnO NRs photodetector with high responsivity, low cost has a great potential for application in manufacturing flexible and transparent integrated optoelectronics.

In this study, the structural, electronic and optical properties of a tungsten disulfide (WS2) hybrid with indium-gallium-zinc-oxide (IGZO) heterostructures were investigated based on density functional theory (DFT) calculations. According to the results of binding energy, charge density difference and electron localization function of heterostructures, we found that the WS2 and IGZO monolayers were bound to each other via non-covalent interactions with large binding energy. The calculated results illustrate that the AAii stacking pattern has an indirect band gap of 1.643 eV, while AAi and AB stacking patterns have maximum direct-gaps of 1.102 eV and 1.234 eV, respectively. Under an external E-field and mechanical strain, the response of the energy gap of the WS2/IGZO heterostructure monotonically decreased over a wide range, even with a semiconductor-metal transition. In addition, we investigated the optical properties of the heterostructure and found that it exhibits a much broad spectral responsivity (from visible light to deep UV light) and a more pronounced optical absorption than WS2 and IGZO monolayers. Moreover, the tensile strain could weaken the photoresponse of the heterostructure to the UV light and enhance the response for the visible light; under compressive strain, the heterostructure showed a strong absorption peak in the UV light. Meanwhile, a red-shift was observed under an external strain. All these unique and tunable properties indicate that the WS2/IGZO heterostructure is a good candidate for nanoelectronic and photoelectronic devices, such as field-effect transistors, flexible sensors, photodetectors and photonic devices.

Cytokine-induced killer (CIK) cells are heterogeneous, major histocompatibility complex (MHC)-unrestricted T lymphocytes that have acquired the expression of several natural killer (NK) cell surface markers following the addition of interferon gamma (IFN-&gamma, ), OKT3 and interleukin-2 (IL-2). Treatment with CIK cells demonstrates a practical approach in cancer immunotherapy with limited, if any, graft versus host disease (GvHD) toxicity. CIK cells have been proposed and tested in many clinical trials in cancer patients by autologous, allogeneic or haploidentical administration. The possibility of combining them with specific monoclonal antibodies nivolumab and ipilimumab will further expand the possibility of their clinical utilization. Initially, phenotypic analysis was performed to explore CD3, CD4, CD56, PD-1 and CTLA-4 expression on CIK cells and PD-L1/PD-L2 expression on tumor cells. We further treated CIK cells with nivolumab and ipilimumab and measured the cytotoxicity of CIK cells cocultured to renal carcinoma cell lines, A-498 and Caki-2. We observed a significant decrease in viability of renal cell lines after treating with CIK cells (p &lt, 0.0001) in comparison to untreated renal cell lines and anti-PD-1 or anti-CTLA-4 treatment had no remarkable effect on the viability of tumor cells. Using CCK-8, Precision Count Beads&trade, and Cell Trace&trade, violet proliferation assays, we proved significant increased proliferation of CIK cells in the presence of a combination of anti-PD-1 and anti-CTLA-4 antibodies compared to untreated CIK cells. The IFN-&gamma, secretion increased significantly in the presence of A-498 and combinatorial blockade of PD-1 and CTLA-4 compared to nivolumab or ipilimumab monotreatment (p &lt, 0.001). In conclusion, a combination of immune checkpoint inhibition with CIK cells augments cytotoxicity of CIK cells against renal cancer cells.

Single-crystal (SC) perovskite is currently a promising material due to its high quantum efficiency and long diffusion length. However, the reported perovskite photodetection range ( 10 μs) are still limited. Here, to promote the development of perovskite-integrated optoelectronic devices, this work demonstrates wider photodetection range and shorter response time perovskite photodetector by integrating the SC CH3NH3PbBr3 (MAPbBr3) perovskite on silicon (Si). The Si/MAPbBr3 heterojunction photodetector with an improved interface exhibits high-speed, broad-spectrum, and long-term stability performances. To the best of our knowledge, the measured detectable spectrum (405-1064 nm) largely expands the widest response range reported in previous perovskite-based photodetectors. In addition, the rise time is as fast as 520 ns, which is comparable to that of commercial germanium photodetectors. Moreover, the Si/MAPbBr3 device can maintain excellent photocurrent performance for up to 3 months. Furthermore, typical gray scale face imaging is realized by scanning the Si/MAPbBr3 single-pixel photodetector. This work using an ultrafast photodetector by directly integrating perovskite on Si can promote advances in next-generation integrated optoelectronic technology.

Background Conventional hepatitis B virus (HBV) vaccines fail to induce protective antibody titers in 5–10% of immune-competent vaccines. Therefore, safe and effective HBV vaccines are still clinically needed. Methods In this study, we developed a plasmid DNA vaccine encoding CD317 single-chain fragment variable (α317scFv) linked with the hepatitis B surface antigen (HBsAg) and detected the humoral and cellular immune responses elicited by this vaccine in BALB/c mice. Results Vaccination with this fusion DNA vaccine in BALB/c mice induced more robust antiviral T cell and antibody immunity against HBsAg. Compared with mice vaccinated with control vaccine encoding HBsAg, the level of serum-circulating anti-HBsAg antibody (HBsAb) was nearly double in fusion DNA-vaccinated mice. More interesting, splenic lymphocytes isolated from fusion DNA-vaccinated mice showed more potent proliferation and IFN-γ production after being re-stimulated with recombinant HBsAg in vitro. And not only that, the cytotoxicity of fusion DNA vaccine-sensitized splenocytes was ∼3-fold higher than that of controls. Conclusion Taken together, our results reveal that the fusion DNA vaccine can induce more effective immunological protection against HBV, and is a promising candidate for preventing HBV infection.

We examine whether initial loan sales in the secondary loan market relate to borrowing firms’ accounting conservatism. We find that borrowing firms exhibit a significant decline in accounting conservatism after the initial loan sales. We show that the decline in borrower conservatism is more pronounced for firms borrowing from lenders with lower monitoring incentive and for firms with lower incentive to supply conservatism. The baseline results are robust to a battery of sensitivity tests. Collectively, we provide corroborative evidence that lead lenders’ monitoring incentive is a mechanism through which accounting conservatism is enforced in the private debt market, and that lead lenders play a more prominent role than secondary loan market participants in shaping corporate (conservative) reporting.

With the development of integrated circuits according to Moore’s law, traditional silicon-based devices have gradually reached their performance limitation. Nanoelectronics based on carbon nanomaterials provides a broad prospect for the continuation of Moore’s law. In particular, in the field of optoelectronic devices, it is necessary to further develop new types of nano-optoelectronic devices. Carbon nanotubes (CNTs) are one of the representative materials of nanoelectronics with excellent electrical and optical properties, e.g., high mobility, suitable band structure, and good infrared absorption. The application of CNTs in optoelectronic devices is a very attractive research topic, which has been developed rapidly in recent years. Until now, various prototypes of CNT-based optoelectronic devices have been developed. In this Review, we briefly introduce the structure and photoelectric properties of CNTs. Then, according to different photo-electron coupling mechanisms, four types of CNTs based on optoelectronic devices are introduced in detail, namely, solar cells, photodetectors, light-emitting diodes, and lasers. Intrinsic and composite CNT-based optoelectronic devices are presented in order to describe the development of CNT-based optoelectronic devices. Finally, different material preparation, separation, and mixing methods of CNTs are discussed, which are the methods for basic material preparation for the fabrication of high performance CNT-based optoelectronic devices. An in-depth study of the development trend of CNT-based optoelectronic devices will contribute to the future development of novel high-performance nanoelectronic devices.

Natural energy haversting devices serve as an alternative candidate for power supply in many micro-/nano-systems. However, traditional nanogenerators based on piezoelectricity or triboelectric power generation face challenges in terms of biocompatibility and stability in various biological systems. The bacteriorhodopsin (bR) protein in Halobacterium halobium is an ideal biocompatible material for photoelectric conversion. Conventional bR systems based on ion transport or enhanced light absorption layers have a limited light power conversion speed. On the other hand, bR-based biohybrid devices have a great potential for sensitive light power conversion as compared to conventional nanogenerators. Herein, we present a biohybrid nanogenerator made of bR and horizontally aligned-long carbon nanotubes (CNTs) with electron–ion interaction for the first time for sensitive light power conversion. The bR layer serves as the proton pump, whereas CNTs are utilized to enhance the photocurrent; thus, the photocurrent frequency response improves significantly because of the effect of the electron–ion interaction. The photocurrent shows a linear relationship with the intensity of light and can still obtain a stable signal at a light intensity of 0.03 mW cm−2. With regard to the influence of the light on–off period, the photocurrent initially increases and then decreases with an increase in flickering frequency up to 360 Hz; this can be ascribed to the combinational influence of light switch speed and photocycle decay time. The photocurrent shows highest value (99 nA cm−2) at a frequency of about 50 Hz at a light intensity of 0.43 mW cm−2, which matches well with the frequency standard of the electrical power supply system. Moreover, we found that a higher density of CNTs contributed to improve performance of the nanogenerators. Furthermore, a H+ ion releasing model was proposed to interpret the operating mechanism of the biohybrid nanogenerator. The biohybrid nanogenerator shows great potential for applications as a power source for bio-nanosystems.

Flexible gas sensing is attracting more attention with the development of machine learning and Internet of Things (IoT). Herein, we report flexible and foldable high-performance hydrogen (H2) sensor on all textiles substrate-fabricated by inkjet–printing of reduced graphene oxide (rGO) and its application to wearable environmental sensing. The inkjet-printing process provides the advantages of the compatibility with various substrates, the capability of non-contact patterning and cost-effectiveness. The sensing mechanism is based on the catalytic effect of palladium (Pd) nanoparticles (NPs) on the wide bandgap rGO, which allows facile adsorption and desorption of the nonpolar H2 molecules. The graphene textile gas sensor (GT-GS) demonstrates about six times higher sensing response than the graphene polyimide membrane gas sensor due to the large surface area of the textile substrate. An analysis of the temperature influence on the GT-GS shows better H2 gas response at room temperature than at high temperature (e.g., 120 °C). In addition, with the machine learning-enabled technology and triboelectric-textile to power IoT (temperature and humidity for gas calibration), H2 is well identified for wearable applications with a robust mechanical performance (e.g., flexibility and foldability).

A ferroelectric thin film transistor (Fe-TFT) based on annealing-free hafnium zirconium oxide (HfZrO) is demonstrated in this paper. Indium zinc oxide was used as channel semiconductor. The as-deposited 30-nm HfZrO film implemented as gate dielectric was proved to be crystallized with a mixture of monoclinic, tetragonal, and orthorhombic phases and showed ferroelectricity naturally. Thus, high temperature annealing process was avoided. The transfer characteristic of this Fe-TFT was demonstrated with operating voltage that was smaller than 3 V, memory window about 1 V, and small subthreshold slope (SS) about 82 mV/dec. The charge trapping phenomenon in this device was explored by characterizing the transfer curves with different ranges of gate voltages. This HfZrO-based device with low processing thermal budget and small SS has high potential for Fe-TFT memory which can be used in oxide semiconductor-based systems and applications.

In this paper, field effect transistors (FET) based on different kinds of non-graphene materials are introduced, which are MoS2, WSe2 and black phosphorus (BP). Those devices have their unique features in fabrication process compared with conventional FETs. Among them, MoS2 FET shows better electrical characteristics by applying a SiO2 protective layer; WSe2 FET is fabricated based on a new low pressure chemical vapor deposition (LPCVD) method; BP FET acquires high on/off ratio and high hole mobility by using a simple dry transfer method. Those novel non-graphene materials inspire new design and fabrication process of basic logic device.

Purpose This study examines whether auditors’ pricing decisions on managerial ability are affected by auditor litigation risk (financial distress or financial crisis), auditor’s familiarity with their client or regulatory changes in the post-Sarbanes–Oxley Act of 2002 (SOX) era. Design/methodology/approach Building on the extant audit fee literature, this study constructs an audit fee determinants model to examine how context affects auditors’ pricing of managerial ability. Findings Auditors offer a larger fee discount to more able client management teams when auditors face lower litigation risks or are more familiar with the client. Furthermore, managerial ability has a more pronounced effect on audit fees in the post-SOX era when managers are mandated to play more active roles in financial reporting (i.e. certification of financial statements required by SOX 302). Research limitations/implications Based on the audit risk model (Simunic, 1980), Krishnan and Wang (2015) show that the managerial ability of an audit client is relevant and important to auditors’ pricing decisions. This study demonstrates that managerial ability exhibits a non-linear relationship with audit fees and contextual factors, such as litigation risk, and that auditors’ familiarity with managers can alter the negative association between audit fees and managerial ability. This study extends Krishnan and Wang’s study by offering additional insights into auditors’ use of soft information such as managerial ability. Furthermore, the findings add to the literature on the impact of SOX on audit fees by suggesting that SOX has not only increased overall audit fees (Ghosh and Pawlewicz, 2009; Huang et al., 2009), it has also increased auditors’ price sensitivity to soft information (e.g. managerial ability). Practical implications This study provides insights for audit firms and client companies who are interested in understanding audit fee-pricing decisions. The findings also suggest that auditors need to be sensitive and responsive to various contextual factors when making pricing decisions. Originality/value Previous studies have not addressed the non-linear relationship between audit fees and soft information about managerial ability.

OBJECTIVE Use independent diagnostic data to analyze the screening effectiveness of the pre-Registry commercial driver medical examination (CDME) for obstructive sleep apnea (OSA), and its sensitivity for hypertension; analyze certification lengths where relevant. METHODS CDME screening results for 1668 drivers were compared to polysomnogram diagnostic test results, and CDME screening results were evaluated for 1155 drivers with at least one insurance claim with a hypertension diagnostic code. Any CDME documentation of the medical condition was considered as detection by screening. RESULTS CDME sensitivity was 20.7% for moderate OSA (AHI ≥ 15). While sensitivity was 77.5% for hypertension, 93.3% of drivers with Stage 3 hypertension were certified, contrary to Federal Motor Carrier Safety Administration standards. CONCLUSIONS The pre-Registry CDME was ineffective in screening commercial drivers for OSA. Screening was better for hypertension; incorrect certifications were given to many hypertensive drivers.

In view of the rising index of traffic flow data, how to research and analyze the massive data quickly and accurately has become a hotspot in the field of Intelligent Transportation. This article conducted a study on the accuracy and instantaneity of the short-term traffic flow forecast in big data environment. A combined forecast model based on cluster analysis and Regression Forest in Spark platform was proposed. Through the application of Kmeans, it analyzed the temporal and weather’s correlation of traffic flow by cluster analysis method. In combination with the parallel Regression Forest algorithm as a predictor, Spark distributed computing cluster was deployed and massive data was combined for training and forecast. The experimental results show that the combined forecast model for equivalent data sets is more real-time than the stand-alone operation in the Spark cluster environment. And as the amount of data increases, the advantage is more obvious. Compared with stand-alone support vector machine and regression forest classic machine learning model, it also has better prediction results in terms of forecast accuracy.

To achieve further insight into the pore characteristics, the coal specimens with different bursting proneness before and after uniaxial compression failure are tested and compared in this paper. The data of mercury intrusion test is corrected by that of low-temperature nitrogen adsorption and desorption test (LTNAD). The pore size distribution and pore volume of specimens are obtained. The pore compressibility coefficient is determined based on the fractal dimension of pore. Scanning electron microscope (SEM) and computed tomography (CT) are combined to evaluated the pore connectivity. The value of pore compressibility coefficient of specimens with high bursting proneness is larger than that of medium bursting proneness. It means more compressibility and abrupt failure under stress. The researches of both SEM and CT indicate that the pore connectivity of specimens with medium bursting proneness is better. The results show that great differences exist in the pore characteristics of specimens with high and medium bursting proneness, and uniaxial compression failure exacerbates the complexity of pore characteristics.

this paper first analyses the new challenges of power information network management, difficulties of the power information network resource survey and vulnerability detection are proposed. Then, a linkage model of network resource survey and vulnerability detection is designed, and the framework of three modules in the model is described, meanwhile the process of network resources survey and vulnerability detection linkage is proposed. Finally, the implementation technologies are given corresponding to the main functions of each module.

A low-density parity-check (LDPC)-coded free space optical (FSO) orthogonal frequency-division multiplexing (OFDM) communication system over aggregated exponentiated Weibull (EW) fading channels with pointing errors considered is investigated. On the basis of the probability density function and cumulative distribution function of the composite channel gain, the analytical expressions of average bit error rate (ABER) of this FSO-OFDM system with on–off keying, K -ary quadrature amplitude modulation (QAM) and phase shift keying (PSK) modulation schemes are derived by using generalized Gauss–Lagurre quadrature rule, respectively. Monte Carlo simulations are provided to verify the validity of these three expressions. Furthermore, LDPC codes are applied in the simulation to improve the ABER performance. The results show that the ABER performance of 16-QAM-OFDM is better than that of the 16-PSK-OFDM system over composite EW fading channels, regardless of the turbulence strengths. For the modulation schemes involved, the degradation due to the increase of atmospheric turbulence strength for turbulence only scenario is more severe when compared with pointing errors included case. The study also demonstrates that significant coding gain improvement can be achieved by LDPC codes over EW fading channels, especially under strong turbulence condition. With pointing errors, more coding gain can be obtained when the jitter increases or beamwidth decreases.

We examine the effects of a multinational firm's subsidiary operations in offshore financial centers (OFCs) on bank loan contracting terms. Using a propensity score matched cross-country sample of firms with and without OFC subsidiaries, we find that firms with OFC subsidiaries receive less favorable loan terms than firms without OFC subsidiaries. The results from a difference-in-differences analysis and an analysis of a firm's mutation from a non-OFC firm to an OFC firm support the causal effect of offshore operations on the unfavorable loan terms. Furthermore, focusing on firms with OFC subsidiaries, we find that the intensity of offshore operations affects loan terms unfavorably. We also find that the unfavorable effect is more pronounced for more opaque firms and for firms that are headquartered in countries or jurisdictions with weaker legal enforcement. Our findings indicate that banks view offshore operations of borrowers as a credit risk-increasing factor.

SYNOPSIS In this study, we examine whether and how borrowing firms' financial statement comparability affects the contracting features of syndicated loans. Using a sample of loans issued by U.S. public firms in the syndicated loan market over the period 1992–2008, we find strong and robust evidence that financial statement comparability is negatively associated with loan spread and the likelihood of pledging collateral, and positively associated with loan maturity and the likelihood of including performance pricing provisions in loan contracts. We also find that borrowing firms with greater financial statement comparability are able to complete the loan syndication process more swiftly, form loan syndicates enabling the lead lenders to retain smaller percentages of loan shares, and attract a greater number of lenders and, particularly, a greater number of uninformed participating lenders. Altogether, these findings are consistent with the view that financial statement comparability plays an important role in alleviating information asymmetry in the syndicated loan market. JEL Classifications: G12; G14; M41

Inertial motion sensors located on the animal have been used to study the behaviour of ruminant livestock. The time window size of segmented signal data can significantly affect the classification accuracy of animal behaviours. To date, there have been no studies evaluating the impact of a mixture of time window size features on the accuracy of animal behaviour classification. In this study, data was collected from accelerometers attached to the neck of 17 Merino sheep over a period of two days. We also recorded a ground truth dataset of behaviour recordings (grazing, ruminating, walking, and standing) over the same time period, We then investigated the ability of three machine learning (ML) approaches, Random Forest (RF), Support Vector Machine (SVM) and linear discriminant analysis (LDA), to accurately classify sheep behaviour. Our results clearly show that simultaneous inclusion of features derived from time windows of mixed sizes, ranging from 2 to 15 s, significantly improved the behaviour classification accuracy, in comparison to those determined from a single unique time window size. Of the three ML methods applied here, the RF approach yielded the best results. Together our results show that including features obtained from mixed window sizes improved the classification accuracy of sheep behaviours.

Coal is a complex heterogeneous and anisotropic material conformed with fractal characteristics. The pore and fracture characteristics have important influence on the dynamic disasters including rock burst and gas outburst, however, the relationship between them is not accurately investigated due to inadequate research method. The pore and fracture distribution of coal with different bursting proneness were obtained by comprehensive application of MIP, LTNAD, SEM, and X-ray CT, and then fractal theory and DIC were used to research the pore and fracture characteristics. The result indicated that the modification of MIP result by LTNAD result could effectively eliminate the adverse effect of coal matrix compressibility, exactly reflect the distribution of pore and fracture in coal, and the pore distribution of coal with different bursting proneness were quite different. Gray scale image from SEM and 3D reconstruction technology based on X-ray CT could show the geological structure, fracture structure, and pore structure characteristics of coal. The study of LTNAD, SEM, and X-ray CT showed that these methods complemented each other, the coal had fractal properties, and the fractal dimension value had a positive correlation with the bursting proneness of coal sample.

Facing the challenge from a fast growth in global primary energy consumption during the last two decades, energy conversion and storage with high efficiency and sustainability is demanded. This chapter intends to discuss the broad picture of world energy utilization, and introduce various types of energy storage technologies, their advantages/disadvantages, research at the present stage and sustainability for the future. Specifically, this chapter will introduce the basic working principles of crucial electrochemical energy storage devices (e.g., primary batteries, rechargeable batteries, pseudocapacitors and fuel cells), and key components/materials for these devices.

In private debt contracts with a borrower consent clause, a creditor’s decision to transfer its portion of the loan can be thwarted if the borrower denies the consent to loan transfer. We find that the probability of the inclusion of a borrower consent clause in a private debt contract increases in the intensity of accompanying creditor control rights in the contract. This association is more pronounced for larger and less risky borrowers. We also find that loans with a borrower consent clause have lower secondary market liquidity and larger stock market returns around the announcement of the loans. We argue that consent clauses are important contractual innovations that are created to protect borrowers in response to the rise of the originate-to-distribute model of banking and the recent increase in nonbank investors’ interest in the corporate loan market.