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In this paper, we formed two BC2P/MoS2 van der Waals (vdW) heterostructures, namely BC2P/MoS2-a and -b heterostructures by stacking the MoS2 and BC2P monolayers. First, by analyzing binding energies, flat average differential charge density and elastic constants of two vdW heterostructures, their structures and formation possibility were studied. Two vdW heterostructures are semiconductors with their indirect band gaps as 0.774/1.405 eV and 1.028/1.458 (direct) eV under the GGA-PBE/HSE06 functional, respectively. Moreover, they are two-dimensional materials with close hardness to the graphene. Especially, two vdW heterostructures possess very high absorption coefficients (> 30%) and low reflection coefficients (< 4%) for the visible light, which makes them as novel and potential two-dimensional materials in the application of optoelectronic, electronic and photovoltaics devices. [ABSTRACT FROM AUTHOR]

Considered in this paper is an inverse Robin problem governed by a steady-state diffusion equation. By the Robin inverse problem, one wants to recover the unknown Robin coefficient on an inaccessible boundary from Cauchy data measured on the accessible boundary. In this paper, instead of reconstructing the Robin coefficient directly, we compute first the Cauchy data on the inaccessible boundary which is a linear inverse problem, and then compute the Robin coefficient through Newton's law. For the Cauchy problem, a parameter-dependent coupled complex boundary method (CCBM) is applied. The CCBM has its own merits, and this is particularly true when it is applied to the Cauchy problem. With the introduction of a positive parameter, we can prove the regularized solution is uniformly bounded with respect to the regularization parameter which is a very good property because the solution can now be reconstructed for a rather small value of the regularization parameter. For the problem of computing the Robin coefficient from the recovered Cauchy data, a least square output Tikhonov regularization method is applied to Newton's law to obtain a stable approximate Robin coefficient. Numerical results are given to show the feasibility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

OBJECTIVE: DJ-1 is a negative regulator of PTEN and plays a role in tumorigenesis. Abnormal miR-203 expression is associated with pancreatic cancer. Bioinformatics analysis showed a targeted relationship between miR-203 and DJ-1 3'-UTR. This study investigated whether miR-203 regulates DJ-1 expression and its role in pancreatic cancer cell proliferation, apoptosis, and cisplatin (DDP) resistance. MATERIALS AND METHODS: The Dual-Luciferase reporter gene assay validated the targeted regulation between miR-203 and DJ-1. The DDP-resistant cell line SW1990/DDP was established and divided into miR-NC group and miR- 203 mimic group followed by analysis of the expression of DJ-1, PTEN and p-AKT, cell apoptosis, and proliferation. RESULTS: There was a targeted relationship between miR-203 and DJ-1 mRNA. The expression of miR-203 in SW1990/DDP cells was significantly lower than that in SW1990 cells, while the expression of DJ-1 mRNA and protein was significantly higher than that in SW1990 cells. Compared with miR-NC group, the expression of DJ-1 and p-AKT protein in SW1990/DDP cells was significantly decreased in miR-203 mimic transfection group, while the expression of PTEN was significantly increased with increased cell apoptosis and decreased cell proliferation, as well as reduced DDP resistance. CONCLUSIONS: The decreased expression of miR-203 and the increased expression of DJ-1 is associated with drug resistance in pancreatic cancer cells. Elevated miR-203 can inhibit the expression of DJ-1, affect the activity of PTEN-PI3K/AKT pathway, inhibit the proliferation of pancreatic cancer cells, induce cell apoptosis, and reduce DDP resistance of pancreatic cancer cells. [ABSTRACT FROM AUTHOR]

Bioluminescence tomography (BLT) aims at the determination of the distribution of a bioluminescent source quantitatively. The mathematical problem involved is an inverse source problem and is ill-posed. With the Tikhonov regularization, an optimization problem is formed for the light source reconstruction and it is usually solved by gradient-type methods. However, such iterative methods are often locally convergent and thus the solution accuracy depends largely on initial guesses. In this paper, we reformulate the reduced regularized optimal problem as a nonlinear equation and apply a homotopy method, which is a powerful tool for solving nonlinear problem due to its globally convergent property, to it. Numerical experiments show that the application of the homotopy technique is feasible and can produce satisfactory approximate solutions for a very large range of initial guesses. [ABSTRACT FROM PUBLISHER]

Abstract: Since February 2012, CO2, H2O, and wind data at 10 Hz have been measured by the open‐path eddy covariance systems at 8, 16, 47, 80, 140, 200, and 280 m above ground level on the 325 m Beijing meteorological tower. Analysis of the data from 2013 to 2016 indicates that the annual averaged CO2 concentration increased and the local and regional CO2 emission decreased with the sequestration of background CO2 concentration. The maximum values occurred during winter, and the minimum values occurred during summer. During spring, summer, and autumn, there was a constant CO2 flux layer from 47 m to 140 m. However, during winter, CO2 flux increased with height, and the maximum appeared at approximately 140 m and then decreased with height. Above 47 m, the CO2 fluxes were represented as the net efflux, and below 16 m, the fluxes were near zero or a net uptake. At all observed heights, the diurnal variation in the CO2 concentration displayed a clear cycle with a peak corresponding to the morning transportation rush hour. The local wavelet power spectra of the CO2 concentration, CO2 flux, and other meteorological elements identified significant cross‐wavelet powers near the 24 h and 365 day bands for the CO2 concentration and flux with temperature, wind speed, friction velocity, and turbulent kinetic energy. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To study the expression profile and role of microRNA miR-34a in Leukemia stem cells (LSC) and during its metastasis. We examined upon the enforced expression of miR-34a in TIM3 positive leukemia stem cells and study the impact of leukemia stem cells and its metastasis. PATIENTS AND METHODS: Samples were collected from acute myeloid leukemia (AML) children along with controls. Immunohistochemistry analysis was performed with TIM3 antibody followed by Sorting of TIM3 positive cells by flow cytometry and the expression level of miR-34a was quantified by qRT-PCR assay. RESULTS: Immunohistochemistry in accordance with Sorting of TIM3 positive cells by flow cytometry concludes that the leukemia stem cells (LSC) were present in the samples. Induced expression of miR-34a in TIM3 positive leukemia stem cells (LSC), inhibits the clonogenic expansion, tumor progression and metastasis of leukemia. CONCLUSIONS: The enforced expression of miR-34a in TIM3 positive leukemia stem cells inhibits the leukemia stem cells and its metastasis. Our study illustrates that miR-34a is a key regulator and which will be developed as a novel therapeutic agent against leukemia stem cells (LSC). [ABSTRACT FROM AUTHOR]

Objective: To analyze the gene variation of a genetic coagulation factor Ⅴ (FⅤ) deficiency pedigree and explore the molecular pathogenesis. Methods: The proband was a 32 years old female. The patient was prone to nose bleeding since childhood which was usually self-healed. On March 10, 2021, the proband went to the First Affiliated Hospital of Air Force Medical University for treatment of knee hematoma caused by a fall. None of the family members reported any history of bleeding. The prothrombin time (PT), activated partial thromboplastin time (APTT) and FⅤ activity (FⅤ: C) were detected by clotting method and the FⅤ antigen (FⅤ: Ag) was tested with enzyme-linked immunosorbent assay (ELISA). All exons and flanks of F5 gene were determined by Sanger sequencing. Clustalx-2.1-win, PolyPhen-2 and Swiss-PDBViewer software were used to analyze the conservatism of missense variation sites, whether the variations were harmful and their influences on protein structure and function. MutationTaster and NetGene2 software were used to analyze whether the splice site variation was harmful and its effect on the splice site. Results: The PT and APTT of the proband prolonged to 24.0 s and 69.8 s, respectively. The FⅤ: C and FⅤ: Ag decreased to 6% and 9%, respectively. There were compound heterozygous variations in F5 gene, which included c.911G>A heterozygous missense variation in exon 6 leading to p.Gly276Glu variation and c.5208+1G>A heterozygous missense variation in intron 15. The father and daughter had the p.Gly276Glu heterozygous variation. Her mother and son had the c.5208+1G>A heterozygous variation. Software analysis results of p.Gly276Glu heterozygous variation showed that Gly276 was conserved among homologous species, the variation was harmful, and it could affect the local structure and function of the protein. The c.5208+1G>A heterozygous variation was deleterious and resulted in the disappearance of the splice site, thereby affecting the protein function. Conclusion: The p.Gly276Glu and c.5208+1G>A compound heterozygous variants are deleterious variants associated with the patient's disease and may be the molecular pathogenesis of inherited FⅤ deficiency in this family.

Bacterial mercury oxidation coupled to denitrification offers great potential for simultaneous removal of elemental mercury (Hg 0 ) and nitric oxide (NO) in a denitrifying membrane biofilm reactor (MBfR). Four potentially contributory mechanisms tested separately, namely, membrane gas separation, medium absorption, biosorption and biotransformation, which contributed 4.9%/7.2%, 8.1%/8.9%, 38.8%/9.5% and 48.2%/84.9% of overall Hg 0 /NO removal in MBfR. Herein, Hg 0 bio-oxidation, oxidative Hg 0 biosorption and denitrification played leading roles in simultaneous removal of Hg 0 and NO. Living microbes performed simultaneous Hg 0 bio-oxidation and denitrification, in which Hg 0 as electron donor was biologically oxidized to oxidized mercury (Hg 2+ ), while NO as the terminal electron acceptor was denitrified to N 2 . The Hg 2+ further complexed with humic acids in extracellular polymeric substances via functional groups (-SH, -OH, -NH - and -COO - ) and formed humic acids bound mercury (HA-Hg). Non-living microbial matrix performed oxidative Hg 0 biosorption, in which Hg 0 may be physically adsorbed by cellular matrix, then non-metabolically oxidized to Hg 2+ via oxidative complexation with -SH in humic acids and finally cleavage of S-H bond and surface charge transfer led to formation of HA-Hg. Therefore, bioconversion of Hg 0 to HA-Hg by Hg 0 bio-oxidation and oxidative Hg 0 biosorption coupled with NO denitrification to N 2 dynamically cooperated to accomplish simultaneous removal of Hg 0 and NO in MBfR., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Photocatalytic membrane coupled to biodegradation offers potential for degrading volatile organic compounds (VOCs) in photocatalytic membrane biofilm reactor. An intimately coupled photocatalysis and biodegradation reactor was operated in continuous operation for 500 days to treat simulated waste gas containing toluene. Toluene removal efficiency obtained 99%, with the elimination capacity of 550 g m -3 ·h -1 . Membrane photocatalysis coupled to biodegradation was created to improve toluene removal from 11 to 20%. The dominant genera were Lysinibacillus, Hydrogenophaga, Pseudomonas at 30 d, Rudaea, Dongia, Litorilinea at 230 d xyl, Tod, Tcb, Bed, Tmo, Tbu, Tou, Dmp, Cat were functional genes of toluene metabolism, as shown by16S rDNA and metagenomic sequencing. Photocatalysis destroyed part of the toluene into biodegradable intermediates that were immediately mineralized by microorganisms in biofilm, some toluene was directly degraded by toluene degrading bacterial community into carbon dioxide and water. The novel hybrid photocatalytic membrane biofilm reactor is a cost-effective and robust alternative to VOCs treatment., (Copyright © 2019. Published by Elsevier Inc.)

Objective: To analyze the base situation and influential factors of late diagnosis among newly identified HIV/AIDS cases in Anhui Province from 2011 to 2015. Methods: Database information of the newly identified HIV/AIDS cases in Anhui Province from 2011 to 2015 were downloaded from the National HIV/AIDS Comprehensive Information System of China's disease prevention and control information system. To analyze the data including basic information, sample source, route of HIV transmission, population mobility, venereal disease, death and first CD4 count; and the number of 7 073 cases were classified according to late diagnosis and non-late diagnosis criteria. The Chi-square test and logistic regression analysis were used to analyze the influential factors of HIV late diagnosis. Results: A total of 7 073 newly identified HIV/AIDS cases were analyzed, and the mean age was (38.5±15.0) years. The proportion of late diagnosis in all counted cases was 41.7% (2 949/7 073); from 2011 to 2015, the proportions of late diagnosis were 59.7% (485/812), 46.5% (531/1 141), 42.7% (587/1 376), 36.1% (609/1 686), and 35.8% (737/2 058), respectively. Compared with the 0 to 19 years group, the 40 to 59 years group and over 60 years old group have higher risk of late diagnosis ( OR= 2.68, 95 %CI: 1.94-3.71; OR= 2.18, 95 %CI: 1.53-3.10, respectively). Compared with the high education group, the illiterate and primary school education group have higher risk of late diagnosis ( OR= 1.74, 95 %CI: 1.36-2.22; OR= 1.64, 95 %CI: 1.34-2.01, respectively). Compared with other sample sources, medical institutions have higher risk of late diagnosis ( OR= 2.64, 95 %CI: 2.28-3.05). Compared with migrant population, the resident population have higher risk of late diagnosis ( OR= 1.80, 95 %CI: 1.53-2.11). Conclusion: The proportion of late diagnosis among newly identified HIV/AIDS cases in Anhui province was relatively high from 2011 to 2015. The main risk factors of late diagnosis included cases reported by medical institutions, resident population, over 40 years old age group and low education level.

Objective: To evaluate vitamin D status in middle-aged subjects in Beijing and explore the correlation between serum 25-hydroxyvitamin D[25(OH)D] levels and dyslipidemia., Methods: A total of 448 individuals over 40 years old were enrolled in the cross-sectional survey. The general information, blood biochemical and lipid profiles and serum 25(OH)D levels were collected. The subjects were either divided into two groups (the dyslipidemia group and the non-dyslipidemia group) based on the lipid levels, or four groups according to quartiles of 25(OH)D levels. The association between 25(OH)D levels and dyslipidemia risk was analyzed by a logistic regression analysis., Results: A total of 234 cases were in dyslipidemia group, which accounted for 52.23% of the subjects. The serum 25(OH)D levels were significantly lower in the dyslipidemia group than in the non-dyslipidemia group both in men and in women (all P<0.05). The median serum 25(OH)D level in the total subjects was 15.7 (12.2, 20.1)μg/L with 91.1% subjects of serum 25(OH)D level<30 μg/L. The proportion of subjects with dyslipidemia (high TC, high TG, high LDL-C, or low HDL-C) increased with the decrease of 25(OH)D level quartiles (P<0.05). After adjustment of confounding factors, the logistic regression analysis showed that subjects in the lowest 25(OH) D quartile group had 143% higher risks for dyslipidemia than those in the highest quartile group., Conclusion: These findings indicate that 25(OH)D insufficiency is highly prevalent among middle-aged individuals and it may be associated with the risk of dyslipidemia.

Objective: To investigate the relationship between sex hormones and metabolic syndrome (MS), as well as its components in elderly men., Methods: 1 505 elderly men (≥60 years old, mean age 75.4±9.7 years old) who participated in a routine health screening examination in PLA general hospital from May to June in 2012 were enrolled in this cross-sectional study. Serum lipids, glucose and sex hormones were measured along with body height, weight and blood pressure. Free testosterone (FT) and bioavailable testosterone (BT) were calculated. The correlation of serum sex hormones with the presence of MS and its components were analyzed., Results: The prevalence of MS was 21.7% (326/1 505) in this study. Elderly men with MS had lower levels of sex hormone-binding globulin (SHBG), total testosterone (TT), FT and BT than those without MS. The levels of SHBG, TT, FT and BT were significantly lower in the overweight/obesity group, hyperglycemia group and dyslipidemia group than those in the respective control groups (P<0.05). Logistic regression analysis showed that the SHBG level was an independent risk factor for MS in elderly men(OR=0.977, 95%CI: 0.964-0.989, P<0.001), while the levels of TT, FT and BT were not associated with MS. The prevalence of MS gradually increased with decreasing of SHBG values (P<0.001). When comparing subjects in the lowest and highest quartile of SHBG, the former group demonstrated a 2.13-fold increase in the odds ratio for MS after adjusting for age, smoking, drinking and other sex hormone indices., Conclusion: In elderly men, lower SHBG level, not TT, FT or BT may be an independent predictor for the prevalence of MS, in which the mechanism requires further studies.

Objective: To investigate the clinical efficacy, safety, predictability, corneal sensitivity, tear function and recovery of subbasal nerves after femtosecond lenticule extraction (FLEx) and laser in situ keratomileusis (LASIK)., Methods: In this prospective, nonrandomized, comparative clinical study, 49 patients (98 eyes) were divided into two groups. FLEx was performed to treat myopia by Visumax femtosecond laser system, and LASIK was performed by Allegretto Wave laser system. The patients were followed up for 6 months. Visual acuity, manifest refraction, intraocular pressure, slit-lamp examination, corneal topography by Pentacam, tear break-up time, Schirmer test, corneal sensitivity and confocal microscopy were assessed., Results: Forty-four patients (88 eyes) completed the 6-month follow-up. Best corrected visual acuity (BCVA) was 0.89±0.14 in eyes with FLEx and 0.98±0.08 in eyes with LASIK at 1 day after surgery. After 10 days, BCVA was 0.98±0.09 and 1.02±0.09, respectively. At the final follow-up visit, the efficacy index was 1.09 in the FLEx group and 1.07 in the LASIK group, and the safety index was 1.12 and 1.07, respectively, in the two groups. Mean Schirmer score was (16.92±7.58) mm and (15.03±5.89) mm (t=1.316, P=0.192), mean tear break-up time was (8.94±2.57) s and (8.00±2.39) s (t=1.759, P=0.082), and corneal sensitivity was (56.46±4.49) mm and (51.38±8.16) mm (t=1.316, P=0.001) in the groups of FLEx and LASIK, respectively. At 10 days after surgery, the number of subbasal nerves was significantly decreased in the FLEx group, and in the LASIK group the subbasal nerve fibers were hardly observed. At 6 months, regenerated nerve fibers were evident in the subbasal area, which recovered faster in eyes with FLEx than in those with LASIK., Conclusions: Femtosecond lenticule extraction appears to be efficient, safe and predictable for myopia. FLEx surgery is superior over LASIK in less reduction of corneal sensation and lower risk of harm to the subbasal nerve fibers.