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Abstract MXenes, an emerging two-dimensional (2D) transition metal carbides, nitrides and carbonitrides, have exhibited great potential as electrocatalysts for hydrogen evolution reaction (HER) due to the excellent characters, including excellent structural and chemical stability, superior electrical conductivity, and large active surface area. In this comprehensive study, firstly, the preparation advances of MXenes are systematically summarized. Then, the representative applications of MXenes-based HER electrocatalysts are introduced, from experimental and theoretical aspects. Thirdly, the strategies for improving HER catalytic activity of MXenes are demonstrated, such as optimizing active sites by termination modification and metal-atom doping, increasing active sites by fabricating various nanostructures. Finally, the existing challenges and new opportunities for MXenes-based electrocatalysts are also elucidated. This paper provides reference for the future development of new and efficient MXenes-based electrocatalysts for hydrogen production through water-splitting technology.

Excitonic effects induced via Coulomb interactions and an appropriate interfacial contact of electrode modified materials play crucial roles in transfer/separation of interfacial charge carriers during the electrochemical sensing process. Herein, an oxygen vacancy (Vo) mediated step-scheme (S-scheme) heterojunction of WO2.9/g-C3N4 was fabricated by electrostatic self-assembly of high-purity commercial WO2.9 nanoparticles and ultrathin g-C3N4 nanosheets, where g-C3N4 nanosheets were prepared via polymerization followed ultrasonic-assisted exfoliation. The fabricated Vo-S-scheme WO2.9/g-C3N4 heterojunction-based sensor exhibited superior electrochemical performance for detecting environmental hormone 4-nitrophenol (4-NP). Due to the introduction of Vo, an increased free-charge-carriers, a built-in electric field and a high adsorption energy are generated at the heterojunction interface, which all can significantly improve the sensitivity of this proposed sensor. It also showed good reproducibility, high accuracy, good recovery, and strong feasibility for 4-NP detection in real samples. This work not only conduces significantly to understanding the defective structures and S-scheme heterojunctions, but also provides new insights into designing and constructing novel efficient electrochemical sensors.

BackgroundKidney Renal Clear Cell Carcinoma (KIRC) is one of the most prevalent types of cancer worldwide. KIRC has a poor prognosis and, to date, immunotherapy based on immune checkpoints is the most promising treatment. However, the role of immune checkpoints in KIRC remains ambiguous.MethodsBioinformatics analyses and qRT-PCR were performed to explore and further confirm the prognostic value of immune checkpoint genes and their correlation with immune infiltration in KIRC samples.ResultsThe expression of the immune checkpoint genes CD274, PDCD1LG2, HAVCR2, CTLA4, TIGFT, LAG3, and PDCD1 was upregulated in KIRC tissues. These genes were involved in the activation of the apoptosis pathway in KIRC. Low expression of CD274 and HAVCR2 and high expression of CTLA4 were associated with poor overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) of KIRC patients. The univariate and multivariate analyses revealed that CTLA4, HAVCR2, age, pTNM stage, and tumor grade were independent factors affecting the prognosis of KIRC patients. A predictive nomogram demonstrated that the calibration plots for the 3‐year and 5‐year OS probabilities showed good agreement compared to the actual OS of KIRC patients. The expression of CTLA4 and HAVCR2 were positively associated with immune cell infiltration, immune biomarkers, chemokines, and chemokine receptors. Moreover, miR-20b-5p was identified as a potential miRNA target of CTLA4 in KIRC.ConclusionOur study clarified the prognostic value of several immune checkpoint regulators in KIRC, revealing a CTLA4/miR-20b-5p axis in the control of immune cell infiltration in the tumor microenvironment.

Background: Bladder cancer is the ninth most-common cancer worldwide and it is associated with high morbidity and mortality. Tumor mutational burden (TMB) is an emerging biomarker in cancer characterized by microsatellite instability. TMB has been described as a powerful predictor of tumor behavior and response to immunotherapy. Methods: A total of 443 bladder cancer samples obtained from The Cancer Genome Atlas (TCGA) were analyzed for mutation types, TMB values, and prognostic value of TMB. Differentially expressed genes (DEGs) were identified from the TMB groupings. Functional analysis was performed to assess the prognostic value of the first 30 core genes. CIBERSORT algorithm was used to determine the correlation between the immune cells and TMB subtypes. Results: Single nucleotide polymorphism (SNP) and C>T were reported as the most common missense mutations and we also identified a high rate of mutations in TP53, TTN, KMT2D. Bladder cancer patients with high TMB showed a better prognosis. Enrichment analysis of the DEGs revealed that they were involved in the regulation of the P13K-Akt signaling pathway, cytokine-cytokine receptor interaction, and Ras signaling pathway. The high expression of hub genes ADRA2A, CXCL12, S1PR1, ADAMTS9, F13A1, and SPON1 was correlated with poor overall survival. Besides, significant differences in the composition of the immune cells of T cells CD8, T cells CD4 memory activated, NK cells resting and Mast cells resting were observed. Conclusions: The present study provides a comprehensive and systematic analysis of the prediction of TMB in bladder cancer and its clinical significance. Also, the study provides additional prognostic information and opportunities for immunotherapy in bladder cancer. [ABSTRACT FROM AUTHOR]

Background Parapelvic renal cysts are more likely to be symptomatic compared with that of simple peripheral renal cysts, and their treatment remains challenging. This study aimed to assess the feasibility and safety of flexible ureteroscopy in managing symptomatic endogenous renal cystic diseases. Materials and methods Thirty-five patients with symptomatic endogenous renal cystic diseases were treated by ureteroscopic unroofing and drainage into the collecting system. Surgical procedure, patient's outcome, and postoperative complications were retrospectively evaluated. Results Ureteroscopic unroofing and drainage were successful in 35 patients without conversion to open surgery. For patients with successful surgery, the mean operation and hospitalization times were 25.38 ± 3.71 min and 3.01 ± 0.57 d, respectively, with a curative standard rate of 74.3% (26/35). Three patients experienced Clavien grade I and II complications but no serious perioperative complications occurred. During the follow-up period averaging 36 mo, no cysts were detected in 74.3% of patients (26/35); noticeable relief was observed in four patients showing a simple renal cyst (diameter <2 cm). In five patients who presented with polycystic kidneys, the renal volume was decreased by 93.76 ± 7.38 mL per side, on average, compared with pretreatment values. Pain was relieved in all 30 patients with renal cysts. Hydronephrosis disappeared in all 15 patients diagnosed with this condition at presentation. No secondary cyst lesions (such as infection, hematoma formation, and solid cystic changes) occurred. Conclusions The transurethral flexible ureteroscopic incision and drainage for symptomatic endogenous renal cystic diseases has multiple advantages such as minimal trauma, rapid recovery, and a definite curative effect. [ABSTRACT FROM AUTHOR]