Anisotropic and high-mobility C3S monolayer as a photocatalyst for water splitting

Taking into account the high conductivity and stability of carbon materials, such as graphene, and the strong polar covalent bonding character of main-group compounds, we explore potential 2D materials in the C–S binary system through first-principles structure search calculations. Herein, a hitherto unknown semiconducting C3S monolayer is identified, consisting of well-known n-biphenyl and S atom linked benzenes, exhibiting an obvious direction-dependent atomic arrangement. Thus, it exhibits anisotropic mechanical properties and carrier mobility. Its electron mobility reaches 2.14 × 104 cm2 V–1 s–1 in the b direction, along which n-biphenyl units are arranged, and is much higher than that in the well-used MoS2 monolayer and black phosphorus. Meanwhile, the C3S monolayer has high optical absorption coefficients (105 cm–1), high thermal and dynamical stabilities, and a moderate ability to split water. All these desirable properties make the C3S monolayer a promising candidate for applications in novel optoelectronic devices.The authors acknowledge funding support from the Natural Science Foundation of China under Nos. 21873017 and 21573037, the Postdoctoral Science Foundation of China under Grant 2013M541283, the Natural Science Foundation of Jilin Province (20190201231JC), and the Natural Science Foundation of Hebei Province (B2021203030). The work was carried out at National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1 (A). A.B. acknowledges financial support from the Spanish Ministry of Science and Innovation (PID2019-105488GB-I00).Peer reviewe

Achieving high hydrogen evolution reaction activity of a Mo2C monolayer

Two-dimensional Mo2C materials (1T and 2H phases) have emerged as promising electrocatalysts for the hydrogen evolution reaction (HER) due to their low cost, inherent metallicity, and high stability. Unfortunately, the catalytic activity of Mo2C is lower than that of Pt, and it needs to be substantially improved for practical applications. It is necessary and urgent to consider the effect of synergetic interactions among defects, functions, and strain on the HER activity. In this study, the geometric structures, electronic properties, and the HER activity of the Mo2C monolayer, with vacancy defects (i.e. Mo and C), oxygen functionalization, and strain, are studied by using first-principles calculations. According to our results, the combination of Mo vacancies, which can be obtained under C-rich conditions, and oxygen functionalization is the most effective way to improve the HER activity of 1T- and 2H-Mo2C. Considering the abundant active sites and optimal Gibbs free energy of hydrogen adsorption, the 1T phase we obtained shows excellent HER activity even at high H coverage and improves the utilization of active sites, for which the HER activity is comparable to that of Pt. This can be attributed to the fact that oxygen atoms gain more electrons from Mo2C, which weakens the strength of the O–H bond. Our work provides not only an opportunity to better understand the catalytic mechanism, but also a guide to achieving high HER activity of a Mo2C monolayer.The authors acknowledge the funding support from the Natural Science Foundation of China under No. 21873017, 21573037, 11704062, and 51732003, the Postdoctoral Science Foundation of China under grant 2013M541283, and the Natural Science Foundation of Jilin Province (20190201231JC). This work was carried out at National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1 (A). A. B. acknowledges financial support from the Spanish Ministry of Science and Innovation (PID2019-105488GB-I00).Peer reviewe

Wide band gap P3S monolayer with anisotropic and ultrahigh carrier mobility

Phosphorene has offered an additional advantage for developing new optoelectronic devices due to its anisotropic and high carrier mobility. However, its instability in air causes a rapid degradation of the performance of the device. Thus, improving the stability of phosphorene while maintaining its original properties has become the key to the development of high-performance electronic devices. Herein, we propose that the formation of two-dimensional (2D) P-rich P–S compounds could achieve this goal. First-principles swarm-structural searches revealed two previously unkonwn P3S and P2S monolayers. The P3S monolayer, consisting of n-bicyclo-P6 units along the armchair direction, exhibits anisotropic and wide band gap characteristics. Interestingly, its carrier mobility reaches 1.11 × 104 cm2 V–1 s–1 and is much higher than in phosphorene. Its electronic band gap and optical absorption coefficients in the ultraviolet region reach 2.71 eV and 105 cm–1, respectively. Additionally, the P3S monolayer has a high structural stability and resistance to air oxidation.The authors acknowledge funding support from the Natural Science Foundation of China under Nos. 21873017 and 21573037, the Postdoctoral Science Foundation of China under grant 2013M541283, the Natural Science Foundation of Hebei Province (B2021203030), and the Natural Science Foundation of Jilin Province (20190201231JC). The work was carried out at the National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1 (A). A.B. acknowledges financial support from the Spanish Ministry of Science and Innovation (PID2019-105488GB-I00).Peer reviewe

Expression and Transcriptional Regulation of Human ATP6V1A Gene in Gastric Cancers.

Recent studies demonstrate that the invasion and metastasis of gastric cancer (GC) is closely associated with a multi-subunit vacuolar H+-ATPase (V-ATPase). Here we investigated the expression and role of the human ATP6V1A gene that encodes the catalytic subunit A of V-ATPase in GC. We found that ATP6V1A expression level is significantly elevated in GCs compared to normals, but GC patients with higher expression levels of ATP6V1A have a better prognosis. Genomic analysis revealed that APT6V1A copy number is gained in a small fraction of GC patients and lost in a minimum number. Moreover, the ATP6V1A copy number was positively correlated with its mRNA level. To explore additional mechanisms by which ATP6V1A overexpressed in GCs, we investigated the relationship between transcription factor YY1 and ATP6V1A, and found that mRNA expression of YY1 had significant correlation with that of ATP6V1A. To validate that YY1 transcriptionally regulates ATP6V1A, we discovered that the ATP6V1A core promoter region contains three YY1 binding sites. Moreover, RNAi-mediated knockdown of YY1 in GC cells significantly decreased ATP6V1A mRNA and protein expression, while YY1 overexpression increased ATP6V1A expression level. In conclusion, YY1 may play an important regulatory role in ATP6V1A expression with potential mechanistic and clinical implications in GC

Expression and Transcriptional Regulation of Human ATP6V1A Gene in Gastric Cancers.

Recent studies demonstrate that the invasion and metastasis of gastric cancer (GC) is closely associated with a multi-subunit vacuolar H+-ATPase (V-ATPase). Here we investigated the expression and role of the human ATP6V1A gene that encodes the catalytic subunit A of V-ATPase in GC. We found that ATP6V1A expression level is significantly elevated in GCs compared to normals, but GC patients with higher expression levels of ATP6V1A have a better prognosis. Genomic analysis revealed that APT6V1A copy number is gained in a small fraction of GC patients and lost in a minimum number. Moreover, the ATP6V1A copy number was positively correlated with its mRNA level. To explore additional mechanisms by which ATP6V1A overexpressed in GCs, we investigated the relationship between transcription factor YY1 and ATP6V1A, and found that mRNA expression of YY1 had significant correlation with that of ATP6V1A. To validate that YY1 transcriptionally regulates ATP6V1A, we discovered that the ATP6V1A core promoter region contains three YY1 binding sites. Moreover, RNAi-mediated knockdown of YY1 in GC cells significantly decreased ATP6V1A mRNA and protein expression, while YY1 overexpression increased ATP6V1A expression level. In conclusion, YY1 may play an important regulatory role in ATP6V1A expression with potential mechanistic and clinical implications in GC

Efficacy of quadruple therapy with clarithromycin based on faecal molecular antimicrobial susceptibility tests as first-line treatment for Helicobacter pylori infection: a protocol of a single-centre, single-blind, randomised clinical trial in China

Introduction Helicobacter pylori is the most well-known risk factor for gastric cancer. Antibiotic resistance is the main reason for the failure of H. pylori eradication, and understanding the antibiotic resistance before treatment may be the main determinant of successful eradication of H. pylori. This study aims to evaluate the efficacy and safety of quadruple therapy based on faecal molecular antimicrobial susceptibility tests for the first-line eradication of H. pylori infection.Methods and analysis This is a single-centre, single-blind, randomised controlled trial, enrolling 855 patients with H. pylori infection. Patients are randomised to three groups for a 14-day treatment: group A: amoxicillin- and clarithromycin-based bismuth-containing quadruple therapy (BQT) (rabeprazole 10 mg, amoxicillin 1 g, clarithromycin 500 mg and colloidal bismuth 200 mg two times per day); group B: clarithromycin medication history-based BQT (rabeprazole 10 mg, amoxicillin 1 g, furazolidone 100 mg (with clarithromycin medication history)/clarithromycin 500 mg (without clarithromycin medication history) and colloidal bismuth 200 mg two times per day); group C: antimicrobial susceptibility test-based BQT (rabeprazole 10 mg, amoxicillin 1 g, clarithromycin 500 mg (clarithromycin-sensitive)/furazolidone 100 mg (clarithromycin resistant) and colloidal bismuth 200 mg two times per day). The primary end point is the eradication rate. The secondary end points are the incidence of adverse events and compliance.Ethics and dissemination This study was approved by the Ethics Committee of Second Affiliated Hospital, School of Medicine, Zhejiang University (Number 20230103). The results will be published in the appropriate peer-reviewed journal.Trial registration number NCT05718609