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Background: In pancreaticobiliary maljunction (PBM), the sphincter of Oddi can not control bile and pancreatic juice flow, which may lead to two-way reflux of bile and pancreatic juice, thus causing chronic inflammation, thickening, fibrosis and metaplasia of the common bile duct wall. These pathophysiological changes have been linked to disruption of the epithelium barrier in the common bile duct. We hypothesized that the expression of tight junction-associated proteins may be dysregulated in the common bile duct in PBM. In the current study, we sought to analyze the expression of tight junction-associated proteins in the common bile duct epithelium of pediatric patients with PBM.Methods: Specimens of the common bile duct were collected from 12 pediatric patients with PBM and 10 non-PBM controls. The expression of the tight junction-associated proteins occludin and claudin-1 in the epithelium was examined by immunohistochemistry. The Image-Pro Plus v. 6.0 image analysis software was used to calculate the mean qualifying score (MQS) of imunostained sections of common bile duct epithelium. Total protein extracts of common bile duct were analyzed by Western blotting assays to examine expression of occludin, claudin-1 and myosin light chain kinase (MLCK). Spearman correlation analysis was used to analyze the relation between MLCK and occludin, MLCK and claudin-1.Results: Immunostained sections of the common bile duct epithelium showed significantly higher MQS in pediatric patients than controls for occludin (44.11 ± 13.82 vs. 11.30 ± 9.58, P = 0.0034) and claudin-1 (63.44 ± 23.59 vs. 46.10 ± 7.84, P = 0.0384). Western blotting also showed significantly higher expression of occludin, claudin-1 and MLCK in the common bile duct of patients than of controls (P = 0.0023, 0.0015, 0.0488). Spearman correlation analysis showed that MLCK expression correlated positively with the expression of occludin (r s = 0.61538, P = 0.0032) and claudin-1 (r s = 0.7972, P = 0.0019).Conclusions: Occludin and claudin-1 are up-regulated in the common bile duct epithelium of pediatric PBM patients. MLCK may be involved in the process of up-regulation of the tight junction-associated proteins in PBM. [ABSTRACT FROM AUTHOR]

How to identify the optimum switch point of sequential invasive and noninvasive ventilation is the focus of clinical attention on the patients suffering from acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated by acute respiratory failure (ARF). This study aims to explore the clinical significance of taking the change rate of procalcitonin (PCT) as identifying the timing of weaning on the mechanical ventilation for the patients of AECOPD followed by ARF as a complication. There were altogether 140 patients of AECOPD complicated with ARF, who were randomly selected and divided into a study group and a control group respectively. A change rate of serum PCT level exceeding 50% was taken as the switch point selection of tracheal intubation removal for the patients of the study group, while the ‘pulmonary infection control (PIC) window’ was done for those in the control group. With CRP, IL-6, TNF-a, PaCO2, PaO2, and Lac having been detected before and after treatment to them all, clinical indexes were obtained and compared between these two groups. The CRP, TNF-a, and IL-6 levels of the patients in the study group after treatment (p 0.05). Even so, some other indexes available for the study group of patients were found to be lower than those for the control group (p

Chronic myelogenous leukemia (CML) is a type of cancer with a series of characteristics that make it particularly suitable for observations on leukemogenesis. Research have exhibited that the occurrence and progression of CML are associated with the dynamic alterations of histone modification (HM) patterns. In this study, we analyze the distribution patterns of 11 HM signals and calculate the signal changes of these HMs in CML cell lines as compared with that in normal cell lines. Meanwhile, the impacts of HM signal changes on expression level changes of CML-related genes are investigated. Based on the alterations of HM signals between CML and normal cell lines, the up- and down-regulated genes are predicted by the random forest algorithm to identify the key HMs and their regulatory regions. Research show that H3K79me2, H3K36me3, and H3K27ac are key HMs to expression level changes of CML-related genes in leukemogenesis. Especially H3K79me2 and H3K36me3 perform their important functions in all 100 bins studied. Our research reveals that H3K79me2 and H3K36me3 may be the core HMs for the clinical treatment of CML.

Background To explore the relationship between the liver X receptor α gene (LXRα) rsl2221497 polymorphism and the susceptibility of coronary heart disease (CHD) and serum lipids and glucose levels. Methods The single fluorescently labeled probes technique was used to detect the genotype of rsl2221497 in LXRα gene in 240 CHD patients and 250 healthy control subjects. The difference of genotype distribution between the two groups was analyzed using of Chi-square test. The serum lipids and glucose levels between the different genotypes were also compared. Results The risk of CHD in carriers with (AA + GA) genotype was 1.76 times as that in the GG genotype carriers (OR = 1.76, 95%CI: 1.18-2.87, P <0.05), and the risk of CHD in carriers with A allele increased 0.88 times compared to that in G allele carriers (OR = 1.88, 95% CI:1.21-3.43, P <0.01). Logistic regression analysis showed that after adjusting for other confounding factors, A allele was an independent risk for CHD. However, there were no differences in serum lipids and glucose levels between each genotype. Conclusions The rsl2221497 polymorphism in LXRα gene was associated with susceptibility of CHD in Han population. [ABSTRACT FROM AUTHOR]

We report a case of atypical clinical manifestation of pneumonia infected by 2019-novel coronavirus, which is helpful to improve the understanding of the clinical characteristics of pneumonia caused by the virus. At the same time, some suggestions on the discharge criteria and hierarchical management of admission of 2019-nCoV pneumonia are put forward. The results are constructive for effective prevention and control of 2019-nCoV pneumonia and optimizing patient process management in China.

In order to precisely assess gene expression level, a suitable internal reference gene must be chosen to quantify real-time reverse transcription polymerase chain reaction (RT-qPCR) data. For greenbug, Schizaphis graminum, a suitable reference gene for assessing the level of transcriptional expression of target genes has yet to be explored. In our study, eight reference genes, elongation fator 1 beta (Ef1β), TATA box binding protein (TBP), alpha-tubulin (α-TUB), 18S ribosomal (18S), 28S ribosomal (28S), glyceraldehyde-3-phosphate (GAPDH), actin (ACT), and ribosomal protein L18 (RPL18) were evaluated in S. graminum at different developmental stages, tissues, and insecticide treatments. To further explore whether these genes are suitable to serve as internal control, three software-based approaches (geNorm, BestKeeper, and NormFinder), ΔCt method, and one web-based comprehensive tool (RefFinder) were employed to analyze and rank the tested genes. The optimal number of reference genes was determined using the geNorm program, and the suitability of particular reference genes was empirically validated according to normalized gene expression data of three target genes, heat shock protein gene (HSP70), cytocrome P450 gene (SgraCYP18A1), and glutathione S-transferase (GST). We found that the most suitable reference genes varied considerably under different experimental conditions. For developmental stages, α-TUB and 28S were the optimal reference genes; for different tissues, 18S and ACT were suitable reference genes; for insecticide treatments, 28S and α-TUB were suitable for normalizations of expression data. In addition, 28S and α-TUB were the suitable reference gene as they had the most stable expression among different developmental stages, tissues and insecticide treatments. This should be useful for the selection of the suitable reference genes to obtain reliable RT-qPCR data in the gene expression of S. graminum.

Objective: Defects in L-selectin ligand (LSL) expression have been reported to cause implantation failure, but little is known about LSL expression in adenomyosis. This study evaluates LSL expression throughout the menstrual cycle in women with adenomyosis. Materials and methods: Endometrial samples were obtained from reproductive-aged women with adenomyosis who underwent hysterectomy. A total of 42 endometrial biopsies were included. There were 12 women in proliferative phase, 10 in early-secretory phase, 9 in mid-secretory phase, and 11 in late-secretory phase. Immunohistochemistry, western blotting, and RT-PCR were performed to evaluate LSL expression. A non-parametric Kruskal–Wallis one-way analysis of variance with multiple comparisons was performed to examine differences among menstrual phases. Results: Immunohistochemistry analysis with MECA-79 shows that LSL is expressed with weak intensity in the endometrium in all phases. In the luminal epithelium, MECA-79 reactivity increased from the proliferative to the late-secretory phase but decreased in the mid-secretory phase. There were significant differences in the mean histological scores (HSCOREs) among the proliferative, early-secretory, and late-secretory phases (p

It is known that a propagating wave at a certain spatial point can be decomposed into plane waves propagating at different angles. In this work, by designing a gradient index phononic crystal lens (GRIN PCL) with transverse-continuous leaf-like unit cells, we theoretically and experimentally show that the spatial-domain propagating waves in finite periodic structures can be linked to their time-domain vibration behaviors. The full-field instantaneous focusing behaviors of Lamb waves in the proposed leaf-like GRIN PCL give an example of the wave-vibration linkage in finite periodic structures while allowing a certain complexity. The conclusion in this paper can help one skip iterative time-consuming finite element analysis (e.g., time-stepping solutions) to avoid possible numerical instabilities occurred in calculating transient wave field on practical finite metamaterials or phononic crystals having unit cells with complicated configurations.

The preparation and electrical properties of diamond nanocones are reviewed, including a maskless etching process and mechanism of large-area diamond conical nanostructure arrays using a hot filament chemical vapor deposition (HFCVD) system with negatively biased substrates, and the field electron emission, gas sensing, and quantum transport properties of a diamond nanocone array or an individual diamond nanocone. Optimal cone aspect ratio and array density are investigated, along with the relationships between the cone morphologies and experimental parameters, such as the CH4/H2 ratio of the etching gas, the bias current, and the gas pressure. The reviewed experiments demonstrate the possibility of using nanostructured diamond cones as a display device element, a point electron emission source, a gas sensor or a quantum device. [ABSTRACT FROM AUTHOR]

Objective To investigate the relationship between angiotensin converting enzyme (ACE) gene insertion / deletion (I / D) polymorphism and diabetic essential hypertension in elderly population. Methods Polymerase chain reaction (PCR) technique was used in 260 elderly normal control patients, 205 elderly hypertensive patients and 138 elderly diabetic hypertensive patients to detect the I / D polymorphism in ACE gene. Results DD genotype frequency (0.352) and D allele frequency (0.543) in elderly hypertensive patients were higher than those in the normal control patients. DD genotype (0.421) and D allele frequency (0.579) in elderly diabetic hypertensive patients were significantly higher than those in the control patients (0.133 and 0.250). The differences of DD genotype and D allele frequency between the elderly hypertensive patients and the elderly diabetic hypertensive patients were not significant (P > 0.05). Conclusion ACE gene deletion is a risk factor for hypertension but is not a risk factor for diabetes in elderly population. [ABSTRACT FROM AUTHOR]

Background: Dendritic cells (DCs) release bioactive exosomes that play an important role in immune regulation. Because they express low levels of class I major histocompatibility complex (MHC) and co-stimulatory molecules, exosomes derived from donor immature DCs (imDex) prolong allograft survival by inhibiting T-cell activation. However, this effect is limited and does not induce immunological tolerance when imDex are administered alone. Thus, we tested the effect of combined treatment with donor imDex and low-dose rapamycin on inducing tolerance in a mouse cardiac transplantation model. Methods: ImDex were obtained from the culture supernatant of immature DCs derived from donor mouse (C57BL/6) bone marrow and were injected with suboptimal doses of rapamycin into recipient mouse (BALB/c) before and after transplantation. The capacity of this treatment to induce immune tolerance was analyzed in vitro and in vivo using the mouse cardiac transplantation model. Results: Donor imDex expressed moderate levels of MHC class II and low levels of MHC class I and co-stimulatory molecules, but neither imDex nor subtherapeutic rapamycin dose alone induced cardiac allograft tolerance. Combined treatment with imDex and rapamycin, however, led to donor specific cardiac allograft tolerance. This effect was accompanied by decreased anti-donor antigen cellular response and an increased percentage of spleen CD4+ CD25+ T cells in recipients. Furthermore, this donor specific tolerance could be further transferred to naïve allograft recipients through injection of splenocytes, but not serum, from tolerant recipients. Conclusion: Combined with immunosuppressive treatment, donor imDex can prolong cardiac allograft survival and induce donor specific allograft tolerance. [ABSTRACT FROM AUTHOR]

Background: Emergence of rmtB-positive Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) poses a great threat to antimicrobial treatment options. Methods: From January 2010 to December 2010, non-duplicate KPC-KP isolates from our hospital were screened for rmtB and multiple other resistance determinants with PCR. Subsequent studies included MIC determination, PFGE, and multilocus sequence typing. Records from patients with KPC-KP isolated were retrospectively reviewed. Comparisons of molecular and clinical characteristics between rmtB-positive and rmtB-negative isolates were systematically performed, as well as the environmental colonization study in ICU wards. Results: A total of 84 KPC-KP strains were collected, including 48 rmtB-positive KPC-KP (RPKP) and 36 rmtB-negative KPC-KP (RNKP) isolates. All KPC-KP isolates were multidrug resistant, with colistin and tigecycline being the most active agents. Compared with RNKP, RPKP displayed a much severer resistance phenotype. Susceptibility rates for amikacin (0% for RPKP versus 88.9% for RNKP, p < 0.01), fosfomycin (8.5% for RPKP versus 88.9% for RNKP, p < 0.01), and minocycline (6.7% for RPKP versus 52.8% for RNKP, p < 0.01), were all significantly lower in RPKP strains. Isolates belonging to PFGE pulsetype A and sequence type 11 were predominant in both groups, including 39 (81.3%) RPKP and 22 (61.1%) RNKP isolates. Nevertheless, RNKP showed more complex genetic backgrounds compared with RPKP. Diverse clinical characteristics were found in both cohorts, however, no significant differences were observed between RPKP and RNKP patients. Conclusions: RPKP strains have spread widely and gradually replaced RNKP in our hospital. They seemed to show much severer resistance phenotypes compared with RNKP and had a bigger dissemination potential. Prudent use of available active agents combined with good control practices is therefore mandatory. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between age and axillary lymph node (LN) involvement in Chinese breast cancer patients, and to replicate a recently identified piecewise relationship between age and LN involvement. Methods: A dataset, consisting of 3,715 patients (with complete information on study variables) with operable breast cancer consecutively surgically treated between 1996 and 2006, was derived from the database of Shanghai Cancer Hospital. Univariate and multivariate logistic regression were employed to analyze the relationship between age and LN. We subsequently performed a similar analysis on another dataset including 1,832 consecutive patients treated between 2007 and 2008 to replicate our findings in the first dataset. Results: A U-shaped relationship (previously observed in two European populations) between age and LN status failed to be replicated in our dataset of Chinese patients. Instead, we observed a linear rather than piecewise relationship. After multivariate adjustment, the linear relationship was still present. Moreover, the interaction between age and LN involvement was not modified by tumor size. The odds of LN involvement decreased by 1.5% for each year increase in age (OR 0.985, 95% CI 0.979-0.991, P,0.001). Breast cancer subtypes were also associated with LN status. Proportions of basallike and ERBB2+ subtypes decreased with increasing age. The observations in the first dataset were successfully replicated in a second independent dataset. Conclusion: We confirmed a straightforward but not piecewise relationship between age and LN status in Chinese patients. The different pattern between Chinese and European elderly patients should be considered when making clinical decisions. [ABSTRACT FROM AUTHOR]

The article describes the case of a 72-year-old woman who developed Klebsiella pneumoniae K351 on her wound following a hip replacement. The patient, who went through the procedure while residing in Iran, was transferred to a hospital in Florida in February 2014 for further care. The epidemiology of the New Delhi metallo-ß-lactamase (NDM)-1-producing Enterobacteriaceae is discussed.

Abstract This study investigates peptide components of L-selectin ligand (LSL) and their gene expressions in human endometrium during the natural menstrual cycle. We recruited 41 endometrial samples from reproductive-aged women with leiomyoma and undergoing hysterectomy and 11 endometrial samples from menopausal women as controls. Immunohistochemistry revealed strong MECA-79 expression from the early through the mid-secretory phase and low expression in menopausal endometrium. Five peptide components of LSL were detected in reproductive and menopausal endometrium by one-step quantitative RT-PCR: podocalyxin, endomucin, nepmucin, GlyCAM-1, and CD34. Endomucin differed significantly between the proliferative and early-secretory phases. CHST2 and CHST4 genes (which are involved in the generation of LSL epitopes) were expressed without significant differences among phases. The gene expression of progesterone receptor decreased from the proliferative to the late-secretory phase, and the difference was significant. However, estrogen receptor α expression showed stability among phases. The significant expression of endomucin between the proliferative and early-secretory phases might play a vital role in endometrial receptivity. Further studies are needed to investigate the factors that regulate the expression of endomucin and other LSL peptide components in different phases of the menstrual cycle.

The hydraulic design method for the impact-type energy dissipator is explained. It includes the plane geometry of flow field near the impact pier, the maximum deflection angle corresponding to the Froude number of coming flow, the ratio of the down-stream flow depth to the upstream flow depth of the shock front, the shock angle and the hydrodynamic pressure acting on the impact pier. The effect of non-hydrostatic pressure distribution downstream of the shock front is taken into account. A scheme with three concrete piers as the impact-type energy dissipator at the terminal apron of a spillway is also introduced: These impact blocks are 14. 4 m in length, 22 m in height and 2. 5 m in thickness. A hydraulic model test has been conducted and the test results show that the impact-type energy dissipator has an excellent hydraulic characteristics and the design method proposed is applicable. [ABSTRACT FROM AUTHOR]

Background/Aims: Increasing evidence suggests that T-UCRs are involved in the development of cancer. In this study, we evaluated the role of a macrophage-derived T-UCR, uc.306, in the prognosis of hepatitis B (HBV)-related hepatocellular carcinoma (HCC). Methods: The uc.306 was obtained by screening microassay data obtained during the polarization of U937 cells from the M2 to M1 phenotype. Uc.306 and macrophage molecule markers were detected by qPCR. Immunohistochemical (IHC) assays were used to examine the M1/M2 status of 90 paired HCC tissues. Kaplan-Meier tests and multivariable Cox regression models were used to analyze predictive confidences, survival, and risk factors. Results: In total, 2,977 differentially expressed T-UCRs were obtained, of which 257 showed fold changes >1.5. The uc.306 was upregulated in M1 cells and was predicted to be involved in the Wnt pathway. The IHC results showed that M1 macrophages (CD68+) were present in the para-tumor tissues, while the M2 phenotype (CD163+) was mainly in the HCC tissues. Uc.306 had a lower expression in the HCC tissues than in that of the para-tumor tissues in 30 paired HCC training sets (P < 0.0001), and 252 paired HCC testing sets (P < 0.0001). Low expression of uc.306 was significantly associated with a shorter overall survival (P < 0.05). Conclusions: The uc.306 may be a promising biomarkerfor HBV-related HCC, providing a novel marker for the prognosis of HCC.

CRISPR-Cas systems provide bacteria and archaea with programmable immunity against mobile genetic elements. Evolutionary pressure by CRISPR-Cas has driven bacteriophage to evolve small protein inhibitors, anti-CRISPRs (Acrs), that block Cas enzyme function by wide-ranging mechanisms. We show here that the inhibitor AcrVA4 uses a previously undescribed strategy to recognize the L. bacterium Cas12a (LbCas12a) pre-crRNA processing nuclease, forming a Cas12a dimer, and allosterically inhibiting DNA binding. The Ac. species Cas12a (AsCas12a) enzyme, widely used for genome editing applications, contains an ancestral helical bundle that blocks AcrVA4 binding and allows it to escape anti-CRISPR recognition. Using biochemical, microbiological, and human cell editing experiments, we show that Cas12a orthologs can be rendered either sensitive or resistant to AcrVA4 through rational structural engineering informed by evolution. Together, these findings explain a new mode of CRISPR-Cas inhibition and illustrate how structural variability in Cas effectors can drive opportunistic co-evolution of inhibitors by bacteriophage.

We investigated the distribution and chemical speciation of Cd, Cr, Cu, Pb and Zn in the water level-fluctuating (WLF) zone of the main stream (MS) and tributaries (ZX and MX) of the Three Gorges Reservoir. We evaluated the ecological risk and pollution level from heavy metals based on the Potential Ecological Risk Index (RI), Risk Assessment Code (RAC), and Ratio of Secondary Phase and Primary Phase (RSP). Our results indicated that the total and bio-available heavy metal contents were higher in the tributaries than in the MS. Moderate pollution from Cd and light pollution from Pb were observed both at the MS and ZX sites, whereas the MX site exhibited a pattern of heavy Cd pollution and light Cr and Pb pollution. In our study area, the results indicated that Cd exhibited a higher ecological risk than did the other heavy metals. Finally, the pH and nitrogen content of sediments may play a key role in controlling the amount of heavy metal bioavailability, further inducing a higher potential ecological risk.

LiNixCoyMnzO2 (LNCM)-layered materials are considered the most promising cathode for high-energy lithium ion batteries, but suffer from poor rate capability and short lifecycle. In addition, the LiNi1/3Co1/3Mn1/3O2 (NCM 111) is considered one of the most widely used LNCM cathodes because of its high energy density and good safety. Herein, a kind of NCM 111 with semi-closed structure was designed by controlling the amount of urea, which possesses high rate capability and long lifespan, exhibiting 140.9 mAh·g−1 at 0.85 A·g−1 and 114.3 mAh·g−1 at 1.70 A·g−1, respectively. The semi-closed structure is conducive to the infiltration of electrolytes and fast lithium ion-transfer inside the electrode material, thus improving the rate performance of the battery. Our work may provide an effective strategy for designing layered-cathode materials with high rate capability.

The application of anaerobic digestors to decentralized wastewater treatment systems (DWTS) has gained momentum worldwide due to their ease of operation, high efficiency, and ability to recycle wastewater. However, the microbial mechanisms responsible for the high efficiency and ability of DWTS to recycle wastewater are still unclear. In this study, the microbial community structure and function of two different anaerobic bioreactors (a primary sludge digestor, PSD, and anaerobic membrane bioreactor, AnMBR) of a DWTS located in Germany was investigated using 16S rRNA gene amplicon and metagenomic sequencing, respectively. The results showed that the microbial community structure was remarkably different in PSD and AnMBR. Methanobacteriaceae and Syntrophaceae were identified as the families that significantly differed in abundance between these two bioreactors. We also used genome-centered metagenomics to predict the microbial interactions and methane-generating pathway, which yielded 21 near-complete assembled genomes (MAGs) (average completeness of 93.0% and contamination of 2.9%). These MAGs together represented the majority of the microbial community. MAGs affiliated with methanogenic archaea, including Methanobacterium sp., Methanomicrobiales archaea, Methanomassiliicoccales archaea, and Methanosaeta concilii, were recruited, along with other syntrophic bacterial MAGs associated with anaerobic digestion. Key genes encoding enzymes involved in specific carbohydrate-active and methanogenic pathways in MAGs were identified to illustrate the microbial functions and interactions that occur during anaerobic digestion in the wastewater treatment. From the MAG information, it was predicted that bacteria affiliated with Bacteroidetes, Prolixibacteraceae, and Synergistaceae were the key bacteria involved in anaerobic digestion. In the methane production step, Methanobacterium sp. performed hydrogenotrophic methanogenesis, which reduced carbon dioxide to methane with hydrogen as the primary electron donor. Taken together, our findings provide a clear understanding of the methane-generating pathways and highlight the syntrophic interactions that occur during anaerobic digestion in DWTS.

A comparative study regarding the performance of real-scale oil-free centrifugal chillers having the flooded evaporator or falling film evaporator was conducted in this study. The nominal capacity for the test chillers was around 200~230 USRT (US refrigeration ton) (703~809 kW). The compressors of the two chillers were identical and R-134a was used as the working fluid. Both evaporators employed the same enhanced tubes (GEWA-B) to fulfill phase change. Tests were conducted in full, 75%, 50%, and 25% loading. Test results indicate that both chillers contained a comparable system performance with an integrated part-load value of around 8.62~8.63. The overall heat transfer coefficient for the flooded evaporator was appreciably higher (20~40%) than the falling film evaporator. This is because the falling film flowrate was below the threshold value and the heat transfer was dominated by evaporation mode. Yet, the heat transfer performance for the falling film evaporator was further jeopardized due to starvation of the film flowrate (partial dry-out), especially in the middle or bottom of the tube bundle. This phenomenon became even more pronounced at partial loading (25%), whereas the flooded evaporator did not reveal such a performance dip at partial loading.

ZMT04 muscovite serves as a quality control reference material for K--Ar dating, with a recommended age of 1804 ± 21 Ma (2σ). Here, we check the homogeneity for ZMT04 muscovite and compare its age against the reference material Fish Canyon sanidine (FCs). Five sub-samples of ZMT04 muscovite were irradiated in three different reactors with different irradiation doses, analysed at varying sample masses over different time periods, and subjected to different mass spectrometric measurement procedures in two independent laboratories, which yielded consistent plateau ages with a mean of 1772.2 ± 2.7 Ma (2σ, MSWD = 1.30, and P = 0.18) and RFCs=28.294±0.072Ma ZMT04 = 105.53 ± 0.25 (2sd, MSWD = 0.88, and P = 0.57). The single-grain results are consistent with the multi-grain stepwise heating results, indicating good reproducibility and homogeneity of 40Ar* and K at the single-grain level. A single grain is sufficient to yield a high precision result when the J-value >0.01. We recommend 1 mg as the minimum sample mass to yield enough neutron-induced 39Ar signals for high-precision analysis (J-value <0.001). Accordingly, ZMT04 muscovite can represent a reliable 40Ar/ 39Ar dating and K--Ar dating reference material for Paleoproterozoic geological samples. [ABSTRACT FROM AUTHOR]

In this work we report that after single-walled carbon nanotubes (SWNTs) are sheared with a pair of titanium scissors, the magnetization becomes larger than that of the corresponding pristine ones. The magnetization increases proportionally with the number of SWNTs with sheared ends, suggesting that there exist magnetic moments at the sheared ends of SWNTs. By using the coefficient of this linear relation, the average magnetic moment is estimated to be 41.5 ± 9.8 μB (Bohr magneton) per carbon atom in the edge state at temperature of 300.0 K, suggesting that ultrahigh magnetic fields can be produced. The dangling sigma and pi bonds of the carbon atoms at sheared ends play important roles in determining the unexpectedly high magnetic moments, which may have great potential applications. [ABSTRACT FROM AUTHOR]

Heterostructures from mechanically-assembled stacks of two-dimensional materials allow for versatile electronic device applications. Here, we demonstrate the intrinsic charge transport behaviors in graphene-black phosphorus heterojunction devices under different charge carrier densities and temperature regimes. At high carrier densities or in the ON state, tunneling through the Schottky barrier at the interface between graphene and black phosphorus dominates at low temperatures. With temperature increasing, the Schottky barrier at the interface is vanishing, and the channel current starts to decrease with increasing temperature, behaving like a metal. While at low carrier densities or in the OFF state, thermal emission over the Schottky barrier at the interface dominates the carriers transport process. A barrier height of ∼ 67.3 meV can be extracted from the thermal emission-diffusion theory. [ABSTRACT FROM AUTHOR]

OBJECTIVE:To compare the accuracy of ultrasonography (US) with the current clinical standard of endoscopy for a diagnosis of nasopharyngeal carcinoma (NPC). METHODS:A total of 150 patients suspected of having NPC underwent US and endoscopy. A diagnosis was obtained from an endoscopic biopsy collected from each suspected tumor and was compared with a biopsy obtained from a normal nasopharynx. The diagnostic accuracy of US and endoscopy for NPC was evaluated using receiver operating curve (ROC) analysis performed by MedCalc Software. RESULTS:The sensitivity, specificity, and accuracy of US versus endoscopy for this cohort were 90.1%, 84.8%, and 87.3%for US, and 88.7%, 97.5%, and 93.3% for endoscopy, respectively. Both US and endoscopy exhibited good diagnostic accuracy for NPC with area under the curve (AUC) values of 0.929 and 0.938, respectively. However, this difference was not significant (Z = 0.36, P = 0.72). CONCLUSION:US is a useful tool for the detection of tumors in endoscopically suspicious nasopharynx tissues, and also for the detection of subclinical tumors in endoscopically normal nasopharynx tissues.

The asymmetric unit of the title compound, C14H11NS, contains two molecules in which the dihedral angles between the phenyl rings are 77.23 (7) and 86.30 (7)°. No aromatic π–π stacking interactions are observed.

The complete molecule of the title compound, C12H10ClO2PS, is generated by crystallographic mirror symmetry, with the P, S and Cl atoms lying on the mirror plane. The resulting PO2SCl tetrahedron is significantly distorted [O—P—O = 96.79 (9)°]. The crystal packing exhibits no directional interactions.

In the title compound, C19H15O2P, the dihedral angles between the benzoic acid ring and the phenyl rings are 75.64 (7) and 80.88 (7)°; the dihedral angle between the phenyl rings is 81.35 (7)°. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generate R22(8) loops between the head-to-head carboxylic acid groups.

In practical applications of biochips and bio-sensors, electrokinetic mechanisms are commonly employed to manipulate and analyze the characteristics of single bio-molecules. To accurately and flexibly control the movement of single molecule within micro-/submicro-fluidic channels, the characteristics of current signals at the initial stage of the flow are systematically studied based on a three-electrode system. The current response of micro-/submicro-fluidic channels filled with different electrolyte solutions in non-continuous external electric field are investigated. It is found, there always exists a current reversal phenomenon, which is an inherent property of the current signals in micro/submicro-fluidics Each solution has an individual critical voltage under which the steady current value is equal to zero The interaction between the steady current and external applied voltage follows an exponential function. All these results can be attributed to the overpotentials of the electric double layer on the electrodes. These results are helpful for the design and fabrication of functional micro/nano-scale fluidic sensors and biochips. [ABSTRACT FROM AUTHOR]

The formation mechanism of ice banding in the system of freezing colloidal suspensions, which is of significance in frost heaving, ice-templating porous materials and biological materials, is still a mystery. Recently, the theory of secondary nucleation and growth of ice has been proposed to explain the emergence of a new ice lens. However, this theory has not been quantitatively examined. Here, we quantitatively measure the initial interfacial undercooling of a new ice lens and the nucleation undercoolings of suspensions. We find that the interfacial undercooling cannot satisfy the nucleation undercooling of ice and hence disprove the secondary nucleation mechanism for ice banding. [ABSTRACT FROM AUTHOR]

This paper presents an application of ultra high-performance liquid-chromatography-quadrupole-TOF high resolution mass spectrometry (UHPLC-Q-TOF HRMS) for simultaneous analysis of 23 illegal adulterated aphrodisiac type chemical ingredients in health foods and Chinese Traditional Patent Medicines (CTPMs). The mass spectrometer was operated in Information Dependent Acquisition (IDA) mode, which provides crucial information for the elemental composition analysis, structure elucidation and quantitative analysis simultaneously. Quantitative analysis was performed using the peak areas of the precursor ions in the XICs. The method validation included assessment of selectivity, sensitivity, calibration curve, accuracy, precision, recovery, matrix effect and stability. The results show good linear relationship with the concentrations of the analytes over wide concentration ranges (e.g., 0.05-10 μg/g for sildenafil) as all the fitting coefficients of determination r² are >0.9984. The detection limits (LODs) were in the range of 0.002-0.1 μg/g. The recoveries were able to reach 82.5-103.6%, while the matrix effects ranged from 87.7 to 109.3%. The intra- and inter-day accuracies were in the range of 82.3-113.8%, while the intra- and inter-day precision ranged from 0.4 to 13.6%. Among 40 batches of health foods and 32 batches of CTPMs (including 28 capsules, 32 tablets, 10 liquid and 2 pills) samples, 28 batches of heath foods were positive. The detected chemical ingredients involved sildenafil, tadalafil, aildenafil and sulfoaildenafil. This method can be used for the screening, identification and quantification of illegal adulterated aphrodisiac chemical ingredients in health foods and CTPMs. Moreover, the LC-Q-TOF MS is very useful to structural elucidation of unknown compound. [ABSTRACT FROM AUTHOR]