MSLN induced EMT, cancer stem cell traits and chemotherapy resistance of pancreatic cancer cells

Chemoresistance is one of the main reasons for poor prognosis of pancreatic cancer. The effects of mesothelin (MSLN) on chemoresistance in pancreatic cancer are still unclear. We aim to investigate potential roles of MSLN in chemoresistance and its relationship with proliferation, epithelial-mesenchymal transition (EMT) and cancer stemness of pancreatic cancer cells. Human pancreatic cancer cell lines ASPC-1 and Mia PaCa-2 with high and low expression of MSLN, respectively, were selected. The ASPC-1 with MSLN knockout (KO) and Mia PaCa-2 of MSLN overexpression (OE) were generated. The effects of MSLN on cell phenotypes, expression of EMT-related markers, clone formation, tumor sphere formation, and pathologic role of MSLN in tumorigenesis were detected. Sensitivity of tumor cells to gemcitabine was evaluated. The results showed that adhesion, proliferation, migration and invasion were decreased significantly in ASPC-1 with MSLN KO, whereas increased significantly in Mia PaCa-2 with MSLN OE. The size and the number of clones and tumor spheres were decreased in ASPC-1 with MSLN KO, and increased in Mia PaCa-2 with MSLN OE. In xenograft model, tumor volume was decreased (tumor grew slower) in MSLN KO group compared to control group, while increased in MSLN OE group. Mia PaCa-2 with MSLN OE had a higher IC50 of gemcitabine, while ASPC-1 with MSLN KO had a lower IC50. We concluded that MSLN could induce chemoresistance by enhancing migration, invasion, EMT and cancer stem cell traits of pancreatic cancer cells. Targeting MSLN could represent a promising therapeutic strategy for reversing EMT and chemoresistance in pancreatic cancer cells.

Prevalence, Risk Factors, and Metabolic Characteristics of Metabolically Healthy Obesity in Patients Seeking Bariatric Surgery: A Cohort Study

BACKGROUND

Bariatric surgery is an effective treatment for morbid obesity. However, a subset of individuals seeking bariatric surgery may exhibit a metabolically healthy obesity (MHO) phenotype, suggesting that they may not experience metabolic complications despite being overweight.

OBJECTIVE

This study aimed to determine the prevalence and metabolic features of MHO in a population undergoing bariatric surgery.

METHODS

A representative sample of 665 participants aged 14 or older who underwent bariatric surgery at our center from January 1, 2010 to January 1, 2020 was included in this cohort study. MHO was defined based on specific criteria, including blood pressure, waist-to-hip ratio, and absence of diabetes.

RESULTS

Among the 665 participants, 80 individuals (12.0%) met the criteria for MHO. Female gender (P = .021) and younger age (P < .001) were associated with a higher likelihood of MHO. Smaller weight and BMI were observed in individuals with MHO. However, a considerable proportion of those with MHO exhibited other metabolic abnormalities, such as fatty liver (68.6%), hyperuricemia (55.3%), elevated lipid levels (58.7%), and abnormal lipoprotein levels (88%).

CONCLUSION

Approximately 1 in 8 individuals referred for bariatric surgery displayed the phenotype of MHO. Despite being metabolically healthy based on certain criteria, a significant proportion of individuals with MHO still exhibited metabolic abnormalities, such as fatty liver, hyperuricemia, elevated lipid levels, and abnormal lipoprotein levels, highlighting the importance of thorough metabolic evaluation in this population.

Quercetin Alleviates Lipopolysaccharide-Induced Cardiac Inflammation via Inhibiting Autophagy and Programmed Cell Death

Objective

The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide (LPS) induced septic cardiac dysfunction.

Methods

Specific pathogen-free chicken embryos ( n = 120) were allocated untreated control, phosphate buffer solution (PBS) vehicle, PBS with ethanol vehicle, LPS (500 ng/egg), LPS with quercetin treatment (10, 20, or 40 nmol/egg, respectively), Quercetin groups (10, 20, or 40 nmol/egg). Fifteen-day-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity. At embryonic day 19, the hearts of the embryos were collected for histopathological examination, RNA extraction, real-time polymerase chain reaction, immunohistochemical investigations, and Western blotting.

Results

They demonstrated that the heart presented inflammatory responses after LPS induction. The LPS-induced higher mRNA expressions of inflammation-related factors (TLR4, TNFα, MYD88, NF-κB1, IFNγ, IL-1β, IL-8, IL-6, IL-10, p38, MMP3, and MMP9) were blocked by quercetin with three dosages. Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of TLR4, IFNγ, MMP3, and MMP9 when compared with the LPS group. Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1, and significantly decreased protein expression of claudin 1 when compared with the LPS group. Quercetin significantly downregulated autophagy-related gene expressions (PPARα, SGLT1, APOA4, AMPKα1, AMPKα2, ATG5, ATG7, Beclin-1, and LC3B) and programmed cell death (Fas, Bcl-2, CASP1, CASP12, CASP3, and RIPK1) after LPS induction. Quercetin significantly decreased immunopositivity to APOA4, AMPKα2, and LC3-II/LC3-I in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of AMPKα1, LC3-I, and LC3-II. Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.

Conclusion

Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy, programmed cell death, and myocardiocytes permeability.

Clinical study on the necessity and feasibility of routine MRCP in patients with cholecystolithiasis before LC

BACKGROUND

In the past quite a long time, intraoperative cholangiography(IOC)was necessary during laparoscopic cholecystectomy (LC). Now magnetic resonance cholangiopancreatography (MRCP) is the main method for diagnosing common bile duct stones (CBDS). Whether MRCP can replace IOC as routine examination before LC is still inconclusive. The aim of this study was to analyze the clinical data of patients undergoing LC for cholecystolithiasis, and to explore the necessity and feasibility of preoperative routine MRCP in patients with cholecystolithiasis.

METHODS

According to whether MRCP was performed before operation, 184 patients undergoing LC for cholecystolithiasis in the Department of General Surgery, Beijing Shijitan Hospital, Capital Medical University from January 1, 2017 to December 31, 2018 were divided into non-MRCP group and MRCP group for this retrospective study. The results of preoperative laboratory test, abdominal ultrasound and MRCP, biliary related comorbidities, surgical complications, hospital stay and hospitalization expenses were compared between the two groups.

RESULTS

Among the 184 patients, there were 83 patients in non-MRCP group and 101 patients in MRCP group. In MRCP group, the detection rates of cholecystolithiasis combined with CBDS and common bile duct dilatation by MRCP were higher than those by abdominal ultrasound (P < 0.05). The incidence of postoperative complications in non-MRCP group (8.43%) was significantly higher (P < 0.05) than that in MRCP group (0%). There was no significant difference in hospital stay (P > 0.05), but there was significant difference in hospitalization expenses (P < 0.05) between the two groups. According to the stratification of gallbladder stone patients with CBDS, hospital stay and hospitalization expenses were compared, and there was no significant difference between the two groups (P > 0.05).

CONCLUSIONS

The preoperative MRCP can detect CBDS, cystic duct stones and anatomical variants of biliary tract that cannot be diagnosed by abdominal ultrasound, which is helpful to plan the surgical methods and reduce the surgical complications. From the perspective of health economics, routine MRCP in patients with cholecystolithiasis before LC does not increase hospitalization costs, and is necessary and feasible.

Giant lipoma in the Retzius space resected under laparoscopy: A case report

Lipoma is a common type of benign soft tissue tumor that can occur in the shoulders, neck and back, in addition to other body parts. The Retzius space is a small anatomical space between the pubic symphysis and the bladder located extraperitoneally and filled with loose fatty connective tissue. Giant lipomas are rare in the Retzius space. A 61-year-old Chinese male arrived at Beijing Yanhua Hospital (Beijing, China) due to frequent urination, and CT scan images of the lower abdomen observed a large pelvic mass and left inguinal hernia. Preoperative clinical manifestations and auxiliary examination suggested that the tumor originated from the urinary bladder wall. The maximum tumor diameter was ~25 cm and abdominal pressure was increased. Therefore, laparoscopic pelvic tumor resection combined with inguinal hernia repair was attempted. Intraoperatively, the tumor was found to originate from the Retzius space and the postoperative pathological diagnosis was lipoma. The present case report may serve as a reference for minimally invasive treatment of this type of rare disease in future.

Tunable electronic structures, Rashba splitting, and optical and photocatalytic responses of MSSe-PtO2 (M = Mo, W) van der Waals heterostructures

Binding energies, AIMD simulation and phonon spectra confirm both the thermal and dynamical stabilities of model-I and model-II of MSSe-PtO2 (M = Mo, W) vdWHs. An indirect type-II band alignment in both the models of MSSe-PtO2 vdWHs and a larger Rashba spin splitting in model-II than in model-I provide a platform for experimental design of MSSe-PtO2 vdWHs for optoelectronics and spintronic device applications. Transfer of electrons from the MSSe layer to the PtO2 layer at the interface of MSSe-PtO2 vdWHs makes MSSe (PtO2) p(n)-type. Large absorption in the visible region of MoSSe-PtO2 vdWHs, while blue shifts in WSSe-PtO2 vdWHs are observed. In the case of model-II of MSSe-PtO2 vdWHs, a further blue shift is observed. Furthermore, the photocatalytic response shows that MSSe-PtO2 vdWHs cross the standard water redox potentials confirming their capability to split water into H+/H2 and O2/H2O.

A nomogram based on adipogenesis-related methylation sites in intraoperative visceral fat to predict EWL% at 1 year following laparoscopic sleeve gastrectomy

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is a crucial surgical procedure for patients with obesity. However, epigenetic research in LSG is still in its infancy from the perspective of adipogenesis.

OBJECTIVES

This work aims to develop a model to predict 1 year excess weight loss percentage (EWL)% following LSG in Chinese patients with obesity by examining the DNA methylation profiles of intraoperative visceral fat.

SETTING

University hospital, Beijing, China.

METHODS

Firstly, we classified patients with obesity as either the satisfied group or unsatisfied group depending on whether their EWL% was 50% or higher at 1 year following LSG. After that, we analyzed differentially methylated sites (DMSs) between the satisfied group and unsatisfied group. DMSs were mapped to the corresponding differentially methylated genes. Then, we took the intersection of adipogenesis-related genes and differentially methylated genes and obtained adipogenesis-related DMSs. Next, hub methylation sites were identified by least absolute shrinkage and selection operator analysis. Finally, a nomogram was developed to predict EWL% of Chinese patients with obesity at 1 -year following LSG.

RESULTS

A total of 26 patients with obesity were enrolled in the study, including 13 in the satisfied group and 13 in the unsatisfied group. A total of 16 genes and 31 DMSs were involved in the adipogenesis signaling pathway. Finally, 4 hub methylation sites (cg06093355, cg00294552, cg00753924, and cg17092065) were identified and a predictive nomogram was established.

CONCLUSIONS

The predictive nomogram based on methylation sites including cg06093355, cg00294552, cg00753924, and cg17092065 can predict EWL% at 1 year following LSG in Chinese patients with obesity efficiently.

First-principles study of BX-SiS (X = As, P) van der Waals heterostructures for enhanced photocatalytic performance

The vertical integration of two-dimensional (2D) materials through weak van der Waals (vdW) interactions is gaining tremendous attention for application in nanotechnology and photovoltaics. Here, we performed first-principles study of the electronic band structure, optical and photocatalytic properties of vertically stacked heterostructures based on boron pnictides BX (X = As, P) and SiS monolayers. Both heterobilayers possess a stable geometry and reveal type I band alignment with a direct band gap, indicating substantial transfer of charge across the junction of the same layer. Interestingly, a redshift is found in the visible light region of the optical absorption spectra of BX-SiS heterobilayers. The comparatively larger hole mobility (14 000 cm2 V-1 s-1) of BP-SiS preferably allows hole conduction in the zigzag-direction. More importantly, the excellent band edge values of the standard redox potential and smaller Gibbs free energy for the adsorption of hydrogen (ΔGH*) make them ideal for performing the hydrogen evolution reaction (HER) mechanism under solar irradiation. These findings offer exciting opportunities for developing next-generation devices based on BX-SiS heterobilayers for promising applications in nanoelectronics, optoelectronic devices and photocatalysts for water dissociation into hydrogen to produce renewable clean energy.

Identification of optimal primary tumor resection candidates for metastatic gastric cancer: Nomograms based on propensity score matching

BACKGROUND

This study sought to develop and validate nomograms for screening patients with metastatic gastric cancer (mGC) who are candidates for primary tumor resection (PTR) and evaluating the prognosis of mGC patients after PTR.

METHODS

From 2010 to 2016, we screened mGC patients with complete data from the Surveillance, Epidemiology, and End Results (SEER) database. Depending on whether or not PTR was performed, we categorized patients into surgery and non-surgery groups. A 1:1 propensity score matching (PSM) analysis was used to balance the characteristics of the two groups. The endpoints were overall survival (OS) and cancer-specific survival (CSS). Two predictive nomograms were developed using logistic regression to assess the likelihood of benefit. Two additional prognostic nomograms were developed to assess prognosis in mGC patients after PTR by Cox regression. Finally, nomograms were evaluated using a variety of methodologies.

RESULTS

Our study included 3594 mGC patients who met the criteria. PTR was associated with improved OS and CSS time (median OS time after PSM: 15 vs. 7 months, P < 0.05; median CSS time after PSM: 17 vs. 7 months, P < 0.05). The OS-related predictive nomogram, including age, histologic type, grade, T stage, and chemotherapy, was developed. Moreover, the CSS-related predictive nomogram, including age, histologic type, grade, and chemotherapy, was developed. Sex, histologic type, grade, T stage, N stage, and chemotherapy were found to be correlated with OS. Furthermore, the CSS correlated with histologic type, grade, T stage, N stage, and chemotherapy. Both predictive and prognostic nomograms were found to be valuable and reliable after different types of validation.

CONCLUSION

Predictive nomograms were developed and validated for identifying the optimal PTR mGC candidates. Prognostic nomograms were developed and validated for assessing the prognosis of mGC patients after PTR.

Correction: First principles study of electronic and optical properties and photocatalytic performance of GaN-SiS van der Waals heterostructure

[This corrects the article DOI: 10.1039/D1RA06011B.].

Correction: Theoretical prediction of the electronic structure, optical properties and photocatalytic performance of type-I SiS/GeC and type-II SiS/ZnO heterostructures

[This corrects the article DOI: 10.1039/D3RA01061A.].

Long-term weight loss outcome of laparoscopic Roux-en-Y gastric bypass predicted by weight loss at 6 months in Chinese patients with BMI ≥ 32.5 kg/m2

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is classic bariatric procedure with long-term safety and efficacy. However, no studies have focused on predicting long-term weight loss after LRYGB in Chinese patients with body mass index (BMI) ≥ 32.5 kg/m2. To explore the relationship between initial and long-term weight loss after LRYGB in patients with BMI ≥ 32.5 kg/m2. All patients were followed-up to evaluate BMI, percentage of excess weight loss (%EWL), and comorbidities. Linear and logistic regression were performed to assess the relationship between initial and long-term weight loss. Receiver operating characteristic curve was used to determine optimal cutoff value. We enrolled 104 patients. The median preoperative BMI was 41.44 (37.92-47.53) kg/m2. %EWL ≥ 50% at 5 years was considered as successful weight loss, and 75.00% of the patients successfully lost weight. The cure rates of hypertension, hyperlipidemia, and type 2 diabetes mellitus at 1 year were 84.38%, 33.93%, and 60.82%, respectively. %EWL at 6 months and 5 years were positively correlated and its relationship could be described by following linear equation: %EWL5 years = 43.934 + 0.356 × %EWL6 months (P < .001; r2 = 0.166). The best cutoff %EWL at 6 months after LRYGB to predict 5-year successful weight loss was 63.93% (sensitivity, 53.85%; specificity, 84.62%; area under the curve (AUC) = 0.671). In Chinese patients with BMI ≥ 32.5 kg/m2, %EWL at 6 months and 5 years were positively correlated and %EWL at 5 years could be calculated by following linear equation: %EWL5 years = 43.934 + 0.356 × %EWL6 months.

Correction: Revealing the electronic, optical and photocatalytic properties of PN-M2CO2 (P = Al, Ga; M = Ti, Zr, Hf) heterostructures

[This corrects the article DOI: 10.1039/D3NA00017F.].

Theoretical prediction of the electronic structure, optical properties and photocatalytic performance of type-I SiS/GeC and type-II SiS/ZnO heterostructures

Nowadays, it would be ideal to develop high-performance photovoltaic devices as well as highly efficient photocatalysts for the production of hydrogen via photocatalytic water splitting, which is a feasible and sustainable energy source for addressing the challenges related to environmental pollution and a shortage of energy. In this work, we employ first-principles calculations to investigate the electronic structure, optical properties and photocatalytic performance of novel SiS/GeC and SiS/ZnO heterostructures. Our results indicate that both the SiS/GeC and SiS/ZnO heterostructures are structurally and thermodynamically stable at room temperature, suggesting that they are promising materials for experimental implementation. The formation of SiS/GeC and SiS/ZnO heterostructures gives rise to reduction of the band gaps as compared to the constituent monolayers, enhancing the optical absorption. Furthermore, the SiS/GeC heterostructure possesses a type-I straddling gap with a direct band gap, while the SiS/ZnO heterostructure forms a type-II band alignment with indirect band gap. Moreover, a red-shift (blue-shift) has been observed in SiS/GeC (SiS/ZnO) heterostructures as compared with the constituent monolayers, enhancing the efficient separation of photogenerated electron-hole pairs, thereby making them promising candidates for optoelectronic applications and solar energy conversion. More interestingly, significant charge transfers at the interfaces of SiS-ZnO heterostructures, have improved the adsorption of H, and the Gibbs free energy Δ_H* becomes close to zero, which is optimal for the hydrogen evolution reaction to produce hydrogen. The findings pave the path for the practical realization of these heterostructures for potential applications in photovoltaics and photocatalysis of water splitting.

Revealing the electronic, optical and photocatalytic properties of PN-M2CO2 (P = Al, Ga; M = Ti, Zr, Hf) heterostructures

Using DFT, the electronic structure, optical, and photocatalytic properties of PN (P = Ga, Al) and M₂CO₂ (M = Ti, Zr, Hf) monolayers and their PN-M₂CO₂ van der Waals heterostructures (vdWHs) are investigated. Optimized lattice parameters, bond length, bandgap, conduction and valence band edges show the potential of PN (P = Ga, Al) and M₂CO₂ (M = Ti, Zr, Hf) monolayers in photocatalytic applications, and the application of the present approach to combine these monolayers and form vdWHs for efficient electronic, optoelectronic and photocatalytic applications is shown. Based on the same hexagonal symmetry and experimentally achievable lattice mismatch of PN (P = Ga, Al) with M₂CO₂ (M = Ti, Zr, Hf) monolayers, we have fabricated PN-M₂CO₂ vdWHs. Binding energies, interlayer distance and AIMD calculations show the stability of PN-M₂CO₂ vdWHs and demonstrate that these materials can be easily fabricated experimentally. The calculated electronic band structures show that all the PN-M₂CO₂ vdWHs are indirect bandgap semiconductors. Type-II[-I] band alignment is obtained for GaN(AlN)-Ti₂CO₂[GaN(AlN)-Zr₂CO₂ and GaN(AlN)-Hf₂CO₂] vdWHs. PN-Ti₂CO₂ (PN-Zr₂CO₂) vdWHs with a PN(Zr₂CO₂) monolayer have greater potential than a Ti₂CO₂(PN) monolayer, indicating that charge is transfer from the Ti₂CO₂(PN) to PN(Zr₂CO₂) monolayer, while the potential drop separates charge carriers (electron and holes) at the interface. The work function and effective mass of the carriers of PN-M₂CO₂ vdWHs are also calculated and presented. A red (blue) shift is observed in the position of excitonic peaks from AlN to GaN in PN-Ti₂CO₂ and PN-Hf₂CO₂ (PN-Zr₂CO₂) vdWHs, while significant absorption for photon energies above 2 eV for AlN-Zr₂CO₂, GaN-Ti₂CO₂ and PN-Hf₂CO₂, give them good optical profiles. The calculated photocatalytic properties demonstrate that PN-M₂CO₂ (P = Al, Ga; M = Ti, Zr, Hf) vdWHs are the best candidates for photocatalytic water splitting.

Structural, electronic and thermoelectric properties of GeC and MXO (M = Ti, Zr and X = S, Se) monolayers and their van der Waals heterostructures

Vertical stacking of two-dimensional materials into layered van der Waals heterostructures is considered favourable for nanoelectronics and thermoelectric applications. In this work, we investigate the structural, electronic and thermoelectric properties of GeC and Janus monolayers MXO (M = Ti, Zr; X = S, Se) and their van der Waals (vdW) heterostructures using first-principles calculations. The values of binding energies, interlayer distances and thermal stability confirm the stability of these vdW heterostructures. The calculated band structure shows that GeC monolayer have a direct band gap while MXO (M = Ti, Zr; X = S, Se) and their van der Waals heterostructures show indirect band nature. Partial density of states confirms the type-II band alignment of GeC–MXY vdW heterostructures. Our results shows that ZrSeO (GeC) monolayers and GeC–ZrSO vdW heterostructures have higher power factor, making them promising for thermoelectric device applications.

Calculated Seebeck coefficient (a) and (b) electrical conductivity (c) and (d) and power factor (e) and (f) of GeC–TiSO, GeC–TiSeO, GeC–ZrSO and GeC–ZrSeO vdW heterostructures for 300 K and 800 K, respectively.

An Assessment of the Effect of Bariatric Surgery on Cardiovascular Disease Risk in the Chinese Population Using Multiple Cardiovascular Risk Models

BACKGROUND

Many studies have reported that bariatric surgery may reduce postoperative cardiovascular risk in patient with obesity, but few have addressed this risk in the Chinese population.

OBJECTIVE

To assess the impact of bariatric surgery on cardiovascular disease (CVD) risk in the Chinese population using the World Health Organization (WHO) risk model, the Global risk model, and the Framingham Risk Score.

METHODS

We retrospectively analyzed data collected on patient with obesity who underwent bariatric surgery at our institution between March 2009 and January 2021. Their demographic characteristics, anthropometric variables, and glucolipid metabolic parameters were assessed preoperatively and at their 1-year postoperative follow-up. Subgroup analysis compared body mass index (BMI) < 35 kg/m² and BMI ≥ 35 kg/m², as well as gender. We used the 3 models to calculate their CVD risk.

RESULTS

We evaluated 61 patients, of whom 26 (42.62%) had undergone sleeve gastrectomy (SG) surgery and 35 (57.38%) Roux-en-Y gastric bypass (RYGB) surgery. Of the patients with BMI ≥ 35 kg/m², 66.67% underwent SG, while 72.97% with BMI < 35 kg/m² underwent RYGB. HDL levels were significantly higher at 12 months postoperatively relative to baseline. When the models were applied to calculate CVD risk in Chinese patients with obesity, the 1-year CVD risk after surgery were reduced lot compared with the preoperative period.

CONCLUSION

Patient with obesity had significantly lower CVD risks after bariatric surgery. This study also demonstrates that the models are reliable clinical tools for assessing the impact of bariatric surgery on CVD risk in the Chinese population.

A first principles study of a van der Waals heterostructure based on MS2 (M = Mo, W) and Janus CrSSe monolayers

The strategy of stacking two-dimensional materials for designing van der Waals heterostructures has gained tremendous attention in realizing innovative device applications in optoelectronics and renewable energy sources. Here, we performed the first principles calculations of the geometry, optoelectronic and photocatalytic performance of MS₂-CrSSe (M = Mo, W) vdW heterostructures. The mirror asymmetry in the Janus CrSSe system allows the designing of two models of the MS₂-CrSSe system by replacing S/Se atoms at opposite surfaces in CrSSe. The feasible configurations of both models of the MS₂-CrSSe system are found energetically, dynamically and thermally stable. The studied heterobilayers possess an indirect type-I band alignment, indicating that the recombination of photogenerated electrons and holes in the CrSSe monolayer is hence crucial for photodetectors and laser applications. Remarkably, a red-shift in the optical absorption spectra of MS₂-CrSSe makes them potential candidates for light harvesting applications. More interestingly, all heterobilayers (except W(Mo)S₂-CrSSe of model-I(II)) reveal appropriate band edge positions of the oxidation and reduction potentials of the photocatalysis of water dissociation into H⁺/H₂ and O₂/H₂O at pH = 0. These results shed light on the practical design of the MS₂-CrSSe system for efficient optoelectronic and photocatalytic water splitting applications.

First principles study of optoelectronic and photocatalytic performance of novel transition metal dipnictide XP2 (X = Ti, Zr, Hf) monolayers

Low cost and highly efficient two dimensional materials as photocatalysts are gaining much attention to utilize solar energy for water splitting and produce hydrogen fuel as an alternative to deal with the energy crisis and reduce environmental hazards. First principles calculations are performed to investigate the electronic, optical and photocatalytic properties of novel two dimensional transition metal dipnictide XP₂ (X = Ti, Zr, Hf) monolayers. The studied single layer XP₂ is found to be dynamically and thermally stable. TiP₂, ZrP₂ and HfP₂ systems exhibit semiconducting nature with moderate indirect band gap values of 1.72 eV, 1.43 eV and 2.02 eV, respectively. The solar light absorption is found to be in energy range of 1.65–3.3 eV. All three XP₂ systems (at pH = 7) and the HfP₂ monolayer (at pH = 0) that straddle the redox potentials, are promising candidates for the water splitting reaction. These findings enrich the two dimensional family and provide a platform to design novel devices for emerging optoelectronic and photovoltaic applications.

Low cost and highly efficient two dimensional materials as photocatalysts are gaining much attention to utilize solar energy for water splitting and produce hydrogen fuel as an alternative to deal with the energy crisis and reduce environmental hazards.

Intriguing interfacial characteristics of the CS contact with MX2 (M = Mo, W; X = S, Se, Te) and MXY ((X ≠ Y) = S, Se, Te) monolayers

Using (hybrid) first principles calculations, the electronic band structure, type of Schottky contact and Schottky barrier height established at the interface of the most stable stacking patterns of the CS–MX₂ (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH are investigated. The electronic band structures of CS–MX₂ and CS–MXY MS vdWH seem to be simple sum of CS, MX₂ and MXY monolayers. The projected electronic properties of the CS, MX₂ and MXY layers are well preserved in CS–MX₂ and CS–MXY MS vdWH. Their smaller effective mass (higher carrier mobility) render promising prospects of CS–WS₂ and CS–MoSeTe as compared to other MS vdWH in nanoelectronic and optoelectronic devices, such as a high efficiency solar cell. In addition, we found that the effective mass of holes is higher than that of electrons, suggesting that these heterostructures can be utilized for hole/electron separation. Interestingly, the MS contact led to the formation of a Schottky contact or ohmic contact, therefore we have used the Schottky Mott rule to calculate the Schottky barrier height (SBH) of CS–MX₂ (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH. It was found that CS–MX₂ (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) (in both model-I and -II) MS vdWH form p-type Schottky contacts. These p-type Schottky contacts can be considered a promising building block for high-performance photoresponsive optoelectronic devices, p-type electronics, CS-based contacts, and for high-performance electronic devices.

Electronic band structure, type of Schottky contact and Schottky barrier height established at the interface of the CS–MX₂ (M = Mo, W; X = S, Se, Te) and CS–MXY ((X ≠ Y) = S, Se, Te) MS vdWH.

Long-Term Weight Loss Outcome of Laparoscopic Sleeve Gastrectomy Predicted by the Percentage of Excess Weight Loss at 6 Months in Chinese Patients with Body Mass Index ≥ 32.5 Kg/m2

PURPOSE

To evaluate the predictive effect of the initial weight loss on the long-term weight loss in Chinese patients with a body mass index (BMI) ≥ 32.5 kg/m² who underwent LSG.

PATIENTS AND METHODS

The follow-up was completed via phone or WeChat for outpatients and at the hospital for inpatients. We evaluated the BMI, percentage of excess weight loss (%EWL), and type 2 diabetes mellitus, hypertension, and hyperlipidemia statuses. Linear and logistic regression analyses were performed on the relationship between the initial and long-term weight loss. The optimal cut-off value was determined by receiver operating characteristic (ROC) curve analysis.

RESULTS

We enrolled 307 patients, with a median preoperative BMI of 39.68 (35.68, 45.47) kg/m². %EWL ≥ 50% was regarded as successful weight loss, and 76.55% of the patients lost their weight successfully. (Reviewer #1, comment #4) %EWL at 6 months and 5 years were positively correlated (P < 0.001). Further, the following linear equation could express the relationship: (%EWL_{5 years} = 29.193 + 0.526 × %EWL_{6 months}). %EWL ≥ 58.57% at 6 months was the best predictor of successful weight loss at 5 years after LSG (Reviewer #1, comment #5) (sensitivity, 73.62%; specificity, 73.61%; AUC value, 0.780). Internal verification of the prediction model revealed satisfactory results in terms of discrimination and calibration.

CONCLUSION

In Chinese patients with BMI ≥ 32.5 kg/m² who underwent LSG, %EWL at 6 months and 5 years were correlated. %EWL ≥ 58.57% at 6 months was a predictor of successful long-term weight loss.

Intriguing electronic, optical and photocatalytic performance of BSe, M2CO2 monolayers and BSe-M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures

Using density functional (DFT) theory calculations, we have investigated the electronic band structure, optical and photocatalytic response of BSe, M₂CO₂ (M = Ti, Zr, Hf) monolayers and their corresponding BSe–M₂CO₂ (M = Ti, Zr, Hf) van der Waals (vdW) heterostructures. Optimized lattice constant, bond length, band structure and bandgap values, effective mass of electrons and holes, work function and conduction and valence band edge potentials of BSe and M₂CO₂ (M = Ti, Zr, Hf) monolayers are in agreement with previously available data. Binding energies, interlayer distance and Ab initio molecular dynamic simulations (AIMD) calculations show that BSe–M₂CO₂ (M = Ti, Zr, Hf) vdW heterostructures are stable with specific stacking and demonstrate that these heterostructures might be synthesized in the laboratory. The electronic band structure shows that all the studied vdW heterostructures have indirect bandgap nature – with the CBM and VBM at the Γ–K and Γ-point of BZ for BSe–Ti₂CO₂, respectively; while for BSe–Zr₂CO₂ and BSe–Hf₂CO₂ vdW heterostructures the CBM and VBM lie at the K-point and Γ-point of BZ, respectively. Type-II band alignment in BSe–M₂CO₂ (M = Ti, Zr, Hf) vdW heterostructures prevent the recombination of electron–hole pairs, and hence are crucial for light harvesting and detection. Absorption spectra are investigated to understand the optical behavior of BSe–M₂CO₂ (M = Ti, Zr, Hf) vdW heterostructures, where the lowest energy transitions are dominated by excitons. Furthermore, BSe–M₂CO₂ (M = Ti, Zr, Hf) vdW heterostructures are found to be potential photocatalysts for water splitting at pH = 0, and exhibit enhanced optical properties in the visible light zones.

Using density functional theory calculations, we have investigated the electronic band structure, optical and photocatalytic response of BSe, M₂CO₂ (M = Ti, Zr, Hf) monolayers and their corresponding BSe–M₂CO₂ (M = Ti, Zr, Hf) van der Waals heterostructures.

First principles study of electronic and optical properties and photocatalytic performance of GaN-SiS van der Waals heterostructure

The vertical stacking of two-dimensional materials via van der Waals (vdW) interaction is a promising technique for tailoring the physical properties and fabricating potential devices to be applied in the emerging fields of materials science and nanotechnology. The structural, electronic and optical properties and photocatalytic performance of a GaN-SiS vdW heterostructure were explored using first principles calculations. The most stable stacking configuration found energetically stable, possesses a direct staggered band gap, which is crucial for separating photogenerated charged carriers in different constituents and is efficacious for solar cells. Further, the charge transfer occurred from the SiS to GaN layer, indicating that SiS exhibits p-type doping in the GaN-SiS heterobilayer. Interestingly, a systematic red-shift was observed in the optical absorption spectra of the understudy heterobilayer system. Moreover, the conduction band edge and valence band edge of the monolayers and corresponding heterostructure were located above and below the standard redox potentials for photocatalytic water splitting, making these systems promising for water dissociation for hydrogen fuel production. The results provide a route to design the GaN-SiS vdW heterostructure for the practical realization of next-generation light detection and energy harvesting devices.

Effect of low temperature and high humidity stress on physiology of cucumber at different leaf stages

Low temperature (LT) and high humidity (HH) are important environmental factors in greenhouses and plastic tunnels during the cold season, as they hamper plant growth and development. Here, we studied the effect of LT (day/night: 9/5 °C, 25/18 °C as control) and HH (95%, 80% as control) on young cucumber plants at the 2, 4 or 6 leaf stages. LT+HH stress resulted in a decline in shoot, root and total fresh and dry weights, and decreased P_n , g_s , T_r , F_v /F_m , qP, ETR and chlorophyll, and increased MDA, H₂ O₂ , O₂ ^- , NPQ and C_i as compared to the control at the 2 leaf stage. SOD, POD, CAT, APX and GR were upregulated under LT+HH stress as compared to the control at the 6 leaf stage. ABA and JA increased under LT+HH stress as compared to the control at the 6 leaf stage, while IAA and GA decreased under LT+HH stress as compared to the control at the 2 leaf stage. Our results show that LT+HH stress affects young cucumber plant photosynthetic efficiency, PSII activity, antioxidant defence system, ROS and hormone profile. Plants at the 6 leaf stage were more tolerant than at the 2 and 4 leaf stages under stress conditions.

Stacking effects in van der Waals heterostructures of blueP and Janus XYO (X = Ti, Zr, Hf: Y = S, Se) monolayers

Using first-principles calculations, the geometry, electronic structure, optical and photocatalytic performance of blueP and XYO (X = Ti, Zr, Hf; Y = S, Se) monolayers and their corresponding van der Waal heterostructures in three possible stacking patterns, are investigated. BlueP and XYO (X = Ti, Zr, Hf; Y = S, Se) monolayers are indirect bandgap semiconductors. A tensile strain of 8(10)% leads to TiSeO(ZrSeO) monolayers transitioning to a direct bandgap of 1.30(1.61) eV. The calculated binding energy and AIMD simulation show that unstrained(strained) blueP and XYO (X = Ti, Zr, Hf; Y = S, Se) monolayers and their heterostructures are thermodynamically stable. Similar to the corresponding monolayers, blueP-XYO (X = Ti, Zr, Hf: Y = S, Se) vdW heterostructures in three possible stacking patterns are indirect bandgap semiconductors with staggered band alignment, except blueP-TiSeO vdW heterostructure, which signifies straddling band alignment. Absorption spectra show that optical transitions are dominated by excitons for blueP and XYO (X = Ti, Zr, Hf; Y = S, Se) monolayers and the corresponding vdW heterostructures. Both E VB and E CB in TiSO, ZrSO, ZrSeO and HfSO monolayers achieve energetically favorable positions, and therefore, are suitable for water splitting at pH = 0, while TiSeO and HfSeO monolayers showed good response for reduction and fail to oxidise water. All studied vdW heterostructures also show good response to any produced O2, while specific stacking reduces H+ to H2.

Two-dimensional blue phosphorene–BAs vdW heterostructure with optical and photocatalytic properties: a first-principles study

In this work, we investigated the electronic, optical and photocatalytic properties of a blue phosphorene–BAs (BlueP–BAs) vdW heterostructure using first-principles calculations.

Optoelectronic and photocatalytic applications of hBP-XMY (M = Mo, W; (X ≠ Y) = S, Se, Te) van der Waals heterostructures

Stacking of layers via weak van der Waals interactions is an important technique for tuning the physical properties and designing viable electronic products. Using first-principles calculations, the geometry, electronic structure, and optical and photocatalytic performance of novel vdW heterostructures based on hexagonal boron phosphide (hBP) and Janus (XMY (M = Mo, W; (X ≠ Y) = S, Se, Te)) monolayers are investigated. Favorable (dynamically and energetically) stacking patterns of two different models of hBP-XMY heterostructures are presented with an alternative order of chalcogen atoms at opposite surfaces in SMSe. A direct type-II band alignment is obtained in both models of hBP-SMoSe, hBP-SWSe and hBP-SeWTe, while the rest are type-II indirect bandgap semiconductors. The Bader charge, and planer-averaged and plane-averaged charge density differences are investigated, which show that hBP donates electrons to the SMoSe and SWSe layer in the hBP-SMoSe and hBP-SWSe vdW heterostructure, while in the case of the hBP-SMoTe (hBP-SWTe) and hBP-SeMoTe (hBP-SeWTe) vdW heterostructures, the transfer of electrons is observed from SMoTe (SWTe) and SeMoTe (SeWTe) to hBP. The imaginary part of the dielectric function shows that the lowest energy transitions are dominated by excitons with a systematic red shift for heavier chalcogen atoms. Furthermore, the photocatalytic performance indicates that the hBP-XMY (M = Mo, W; (X ≠ Y) = S, Se, Te) vdW heterostructures in model-I are suitable for water splitting at pH = 0.

Intriguing electronic structure and photocatalytic performance of blueP-SMSe and blueP-SeMS (M = Mo, W) van der Waals heterostructures

Van der Waals (vdW) combination of two dimensional (2D) materials in the form of a heterostructure is a widely accepted tool for tailoring properties and designing novel nanoelectronic and energy harvesting applications. The stacking geometry and electronic and photocatalytic properties of vdW heterostructures based on blueP and Janus SMSe and SeMS (M = Mo, W) monolayers are investigated by using first principles calculations. Two alternate stacking configurations of both heterostructures with an alternative order of chalcogen atoms in SMSe and SeMS (M = Mo, W) are constructed and found to be energetically and thermally stable. The feasible stackings of both heterostructures exhibit type-II band alignment (except blueP–SeMoS), hence are promising for light detection devices. In particular, the suitable positions of the valence and conduction band edges of all the heterostructures (except blueP–SMoSe) are appropriate for standard redox potentials and are capable of splitting water into O₂/H₂O and H⁺/H₂. The findings pave the way for potential applications of these heterobilayer systems in future nanoelectronics, optoelectronics and photocatalytic water dissociation.

The stacking geometry and electronic and photocatalytic properties of vdW heterostructures based on blueP and Janus SMSe and SeMS (M = Mo, W) monolayers are investigated using first principles calculations.

Abdominal infectious complications associated with the dislocation of intraperitoneal part of drainage tube and poor drainage after major surgeries

Abdominal drainage, serving as a diagnostic and therapeutic tool, has been widely applied to prevent complications after major abdominal surgical procedures. However, dislocation of intraperitoneal portion of drainage tube and poor drainage after major surgery has never been detailed. In this retrospective study, we determined whether postoperative abdominal infectious complications are attributed to dislocation of intraperitoneal portion of drainage tube. Patients were recruited from the Department of General Surgery at Beijing Shijitan Hospital, Capital Medical University, between June 2015 and June 2018. All of the enrolled patients had undergone different major abdominal surgical procedures with abdominal drainage. According to different fixation methods of the drainage tube, the patients were categorised as follows: group 1 as conventional extra-abdominal fixation where the tubes were fixed on abdominal wall; group 2 as double fixation where the tubes were fixed by both extra-abdominal and intra-abdominal fixation. Among 60 patients (40 in group 1 and 20 in group 2) with suspected postoperative abdominal infection, abdominal computed tomography (CT) was performed to determine the presence of abnormality. Dislocation of drainage tubes, morbidity, treatment, and prognosis were compared between the two groups. None of the patients showed slip knot or drainage tube slipping from the abdomen based on physical examination and CT imaging. Drainage tube was fixed firmly on the abdominal wall. In group 1, 18 (45%) patients developed postoperative complications resulting from abdominal infection where severe dislocation of intraperitoneal portion of drainage tubes was confirmed by CT. Drainage tubes of six cases were significantly dislocated to the anterior abdominal wall from the target area; 7 upper abdominal drainage tubes dislocated to the lower abdomen; and 5 lower abdominal drainage tubes dislocated to the upper abdomen. Common complications included localised peritonitis (n = 4), abdominal abscess (n = 8), and anastomotic leakage (n = 6). Among them, 8 patients were cured by abdominal puncture catheter drainage; 5 underwent secondary operation and 5 were cured by conservative treatment. In group 2, no tube dislocation was identified by CT. Five patients (25%) developed complications, including localised peritonitis (n = 1), abdominal abscess (n = 1), and anastomotic leakage (n = 3). All the five patients were cured by conservative treatment. Postoperative abdominal infection complications can stem from dislocation of intraperitoneal portion of drainage tube and poor drainage after major abdominal surgery. Maintaining the intraperitoneal portion of drainage tube at the proper location, for example, by applying intraabdominal fixation, is paramount to decrease the incidence and severity of postoperative complications.

Laparoscopic Sleeve Gastrectomy Affects Coagulation System of Obese Patients

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is nowadays the most popular bariatric procedure for obesity. However, whether LSG increases the risk of thrombosis remains unclear. The aim of this study was to investigate potential effects of LSG on coagulation system.

METHODS

Fifty-five obese patients underwent LSG between 2016 and 2018. The LSG was performed with pneumoperitoneum pressure maintained at 13 mmHg. Venous blood specimens were collected from each patient before surgery, at the end of pneumoperitoneum (i.e., 0 h after surgery), and at 24 h after surgery to determine prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), platelet count (PLT), D-dimer (D-D), red blood cell count (RBC), hematocrit (HCT), plateletcrit (PCT), cholesterol (CHOL), triglyceride (TRIG), and serum calcium (Ca). All patients were examined on the veins of the lower limbs by color Duplex sonography (CDS) before surgery and at 24 h after surgery, respectively.

RESULTS

All patients successfully underwent LSG. No severe surgery-related complications were observed during 1-month follow-up after operation. Preoperative BMI was 43.6 ± 8.3 kg/m². The levels of coagulation factors were within the normal range before surgery, except a relatively higher PLT. The PT and D-D were increased at 0 h and 24 h after surgery (P < 0.05), whereas APTT was decreased (P < 0.05). The postoperative FIB remained similar to the preoperative one (P > 0.05). The CDS identified no thrombus in the veins of the lower limbs, either before surgery or at 24 h after surgery.

CONCLUSIONS

LSG may cause postoperative hypercoagulability of patients with obesity.

Computational insights into structural, electronic and optical characteristics of GeC/C2N van der Waals heterostructures: effects of strain engineering and electric field

Vertical heterostructures from two or more than two two-dimensional materials are recently considered as an effective tool for tuning the electronic properties of materials and for designing future high-performance nanodevices. Here, using first principles calculations, we propose a GeC/C₂N van der Waals heterostructure and investigate its electronic and optical properties. We demonstrate that the intrinsic electronic properties of both GeC and C₂N monolayers are quite preserved in GeC/C₂N HTS owing to the weak forces. At the equilibrium configuration, GeC/C₂N HTS forms the type-II band alignment with an indirect band gap of 0.42 eV, which can be considered to improve the effective separation of electrons and holes. Besides, GeC/C₂N vdW-HTS exhibits strong absorption in both visible and near ultra-violet regions with an intensity of 10⁵ cm⁻¹. The electronic properties of GeC/C₂N HTS can be tuned by applying an electric field and vertical strains. The semiconductor to metal transition can be achieved in GeC/C₂N HTS in the case when the positive electric field of +0.3 V Å⁻¹ or the tensile vertical strain of −0.9 Å is applied. These findings demonstrate that GeC/C₂N HTS can be used to design future high-performance multifunctional devices.

Vertical heterostructures from two or more than two two-dimensional materials are recently considered as an effective tool for tuning the electronic properties of materials and for designing future high-performance nanodevices.

Effects of electric field and strain engineering on the electronic properties, band alignment and enhanced optical properties of ZnO/Janus ZrSSe heterostructures

The formation of van der Waals heterostructures (vdWHs) have recently emerged as promising structures to make a variety of novel nanoelectronic and optoelectronic devices. Here, in this work, we investigate the structural, electronic and optical features of ZnO/ZrSSe vdWHs for different stacking patterns of ZnO/SeZrS and ZnO/SZrSe by employing first-principles calculations. Binding energy and ab initio molecular dynamics calculations are also employed to confirm the structural and thermal stability of the ZnO/ZrSSe vdWHs for both models. We find that in both stacking models, the ZnO and ZrSSe layers are bonded via weak vdW forces, leading to easy exfoliation of the layers. More interestingly, both the ZnO/SeZrS and ZnO/SZrSe vdWHs posses type-II band alignment, making them promising candidates for the use of photovoltaic devices because the photogenerated electrons–holes are separated at the interface. The ZnO/ZrSSe vdWHs for both models possess high performance absorption in the visible and near-infrared regions, revealing their use for acquiring efficient photocatalysts. Moreover, the band gap values and band alignments of the ZnO/ZrSSe for both models can be adjusted by an electric field as well as vertical strains. There is a transformation from semiconductor to metal under a negative electric field and tensile vertical strain. These findings demonstrate that ZnO/ZrSSe vdWHs are a promising option for optoelectronic and nanoelectronic applications.

Here, in this work, we investigate the structural, electronic and optical features of ZnO/ZrSSe vdWHs for different stacking patterns of ZnO/SeZrS and ZnO/SZrSe by employing first-principles calculations.

Effects of different surface functionalization on the electronic properties and contact types of graphene/functionalized-GeC van der Waals heterostructures

Constructing vertical heterostructures by placing graphene (Gr) on two-dimensional materials has recently emerged as an effective way to enhance the performance of nanoelectronic and optoelectronic devices.

Electronic structure, optoelectronic properties and enhanced photocatalytic response of GaN–GeC van der Waals heterostructures: a first principles study

In this work, we systematically studied the electronic structure and optical characteristics of van der Waals (vdW) heterostructure composed of a single layer of GaN and GeC using first principles calculations. The GaN–GeC vdW heterostructure exhibits indirect band gap semiconductor properties and possesses type-II energy band arrangement, which will help the separation of photogenerated carriers and extend their lifetime. In addition, the band edge positions of the GaN–GeC heterostructure meet both the requirements of water oxidation and reduction energy, indicating that the photocatalysts have the potential for water decomposition. The GaN–GeC heterostructure shows obvious absorption peaks in the visible region, leading to the efficient use of solar energy. Tensile and compressive strains of up to 10% are also proposed. Tensile strain leads to an increase in the blue shift of optical absorption, whereas a red shift is observed in the case of the compressive strain. These fascinating characteristics make the GaN–GeC vdW heterostructure a highly effective photocatalyst for water splitting.

In this work, we systematically studied the electronic structure and optical characteristics of van der Waals (vdW) heterostructure composed of a single layer of GaN and GeC using first principles calculations.

The value of preoperative lymphocytes-to-monocytes ratio in predicting lymph node metastasis in gastric cancer

Background

This study was aimed to evaluate value of preoperative lymphocytes-to-monocytes ratio (LMR) as a predictor for lymph node metastasis in gastric cancer.

Methods

Patients with pathologically diagnosed malignant gastric tumor were reviewed retrospectively. Patients’ demographic data, clinical manifestations and LMR were collected. The postoperative pathology data including the tumor size, tumor sites, differentiation degree of tumor, depth of tumor invasion, metastatic lymph nodes, total dissected lymph nodes, distant metastasis, vessel carcinoma embolus, neural invasion, Lauren’s classification, Ki-67 and TNM stage were collected. Receiver operating characteristic curve (ROC) was used to determine the cut-off point of LMR. The association between LMR and the clinicopathologic factors was further analyzed.

Results

A total of 177 subjects were enrolled into the study. LMR =3.79 was used as cut-off point; the patients with LMR ≥3.79 were classified as high-LMR group (123 cases) and the patients with LMR <3.79 as low-LMR group (54 cases). LMR was an independent risk factor for lymph node metastasis.

Conclusions

Low preoperative LMR was positively correlated with lymph node metastasis in gastric cancer patients, and had predictive value for lymph node metastasis in gastric cancer patients.

Tailoring the structural and electronic properties of an SnSe2/MoS2 van der Waals heterostructure with an electric field and the insertion of a graphene sheet

van der Waals heterostructures by stacking different two-dimensional materials are being considered as potential materials for nanoelectronic and optoelectronic devices because they can show the most potential advantages of individual 2D materials.

Optoelectronic and solar cell applications of Janus monolayers and their van der Waals heterostructures

Janus monolayers and their van der Waals heterostuctures are investigated by hybrid density functional theory calculations.

Band alignment and optical features in Janus-MoSeTe/X(OH)2 (X = Ca, Mg) van der Waals heterostructures

van der Waals heterostructures can be effectively used to enhance the electronic and optical properties and extend the application range of two-dimensional materials.

Structural and electronic properties of a van der Waals heterostructure based on silicene and gallium selenide: effect of strain and electric field

Combining van der Waals heterostructures by stacking different two-dimensional materials on top of each other layer-by-layer can enhance their desired properties and greatly extend the applications of the parent materials. In this work, by means of first principles calculations, we investigate systematically the structural and electronic properties of six different stacking configurations of a Si/GaSe heterostructure. The effect of biaxial strain and electric field on the electronic properties of the most energetically stable configuration of the Si/GaSe heterostructure has also been discussed. At the equilibrium state, the electronic properties of the Si/GaSe heterostructure in all its stacking configurations are well kept as compared with that of single layers owing to their weak van der Waals interactions. Interestingly, we find that a sizable band gap is opened at the Dirac K point of silicene in the Si/GaSe heterostructure, which could be further controlled by biaxial strain or electric field. These findings open up a possibility for designing silicene-based electronic devices, which exhibit a controllable band gap. Furthermore, the Si/GaSe heterostructure forms an n-type Schottky contact with a small Schottky barrier height of 0.23 eV. A transformation from the n-type Schottky contact to a p-type one, or from the Schottky contact to an ohmic contact may occur in the Si/GaSe heterostructure when strain or an electric field is applied.

Enhanced expression of the long non-coding RNA SNHG16 contributes to gastric cancer progression and metastasis

This paper aimed to probe into the expression of long non-coding RNA (lncRNA) SNHG16 in human gastric cancer (GC) and its potential tumor biological functions. The expression of lncRNA SNHG16 was detected in GC and adjacent tissues and GC cell lines using qRT-PCR. GC MGC-803 cells were transfected with siRNA of lncRNA SNHG16, as well as blank and negative control. A series of experiments including CCK-8, flow cytometry, transwell, and wound healing assay were adopted to evaluate the effects of lncRNA SNHG16 on cell growth and metastasis. Besides, the nude mouse xenograft tumor model was established to draw tumor growth curve and measure tumor volume during treatments. TUNEL staining was used to determine the apoptosis rate of tissues. The expression of lncRNA SNHG16 in GC tissue, significantly associated with invasion depth, lymph node metastasis, TNM stage and histological differentiation (all P< 0.05), was upregulated compared with adjacent tissues. Transfected with siRNA of lncRNA SNHG16 inhibited GC MGC-803 cell proliferation, and arrested cells in the G0/G1 phase, and then promoted apoptosis rate with reduced cell invasion and shortened migration distance. Additionally, the nude mice xenograft presented lower tumor growth rate and weight loss alongside elevated apoptosis rate of tumor tissues. LncRNA SNHG16 is highly expressed in GC, while suppression of SNHG16 expression can inhibit proliferation, weaken invasion and migration of GC cells, and enhance apoptosis, to be a novel target for GC clinical treatment.

Long-limb length difference had no effect on outcomes of laparoscopic Roux-en-Y gastric bypass surgery for obese Chinese patients with type 2 diabetes mellitus: A CONSORT compliant article

Bariatric surgery is effective in treating different components of metabolic syndrome including obesity, type 2 diabetes mellitus (T2DM), and hyperlipidemia. But there is no consensus on the ideal biliopancreatic and Roux limb length. This study aimed to explore the effect of biliopancreatic limb and Roux limb lengths during laparoscopic Roux-en-Y gastric bypass (LRYGB) procedures on weight loss and T2DM control.We studied the clinical records of 58 patients with metabolic syndrome, T2DM, and body mass index (BMI) 32 to 50 kg/m who underwent LRYGB in our hospital. The short limb group (Group A) underwent LRYGB with a limb length of 160 to 200 cm (n = 31) and the long limb group (Group B) underwent LRYGB with a limb length of 210 to 240 cm (n = 27) were compared.The occurrence of acute or chronic internal hernia in Group B was higher than that in Group A (P = .026). Twelve months after surgery, patients from the 2 groups were also observed with reduction in BMI, percent excess weight loss (EWL), preoperative FPG, and HbA1c as compared with these indicators before surgery. However, the differences of these indicators between 2 groups were not significant at the time point of before and 3, 6, 12 months after surgery.LRYGB had significant effects on weight loss and diabetes control in obese T2DM patients. However, there was no significant difference in the short term on weight loss and diabetes control in the patients receiving different limb lengths.