Enhancing NIR-II Upconversion Monochromatic Emission for Temperature Sensing.

The upconversion luminescence (UCL) in the second near-infrared window (NIR-II) is highly attractive due to its excellent performance in high-resolution bioimaging, anticounterfeiting, and temperature sensing. However, upconvertion nanoparticles (UCNPs) are normally emitted in visible light, potentially impacting the imaging quality. Here, a monochromatic Er3+-rich (NaErF4:x%Yb@NaYF4) nanoparticles with excitation at 1532 nm and emission at 978 nm is proposed, both situated in the NIR-II region. The proper proportion of Yb3+ ions doping has a positive effect on the NIR-II emission, by enhancing the cross relaxation efficiency and accelerating the energy transfer rate. Owing to the interaction between the Er3+ and Yb3+ is inhibited at low temperatures, the UCL emission intensities at visible and NIR-II regions show opposite trend with temperature changing, which establishes a fitting formula to derive temperature from the luminous intensity ratio, promoting the potential application of UCL in NIR-II regions for the temperature sensing.

Related barriers to using HIV pre-exposure prophylaxis among MSM: A multicentre cross-sectional survey.

OBJECTIVE: The objective of this study was to gain insight into the barriers hindering the use of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in five cities in China. METHODS: MSM were recruited via community-based organizations in an online "snowball" manner. Participants completed the questionnaire anonymously and shared it with key MSM peers (seeds) in five cities in China. Based on the results of univariate analysis, we used a structural equation model to analyse the role of PrEP knowledge awareness, PrEP counselling, and other behavioural variables on PrEP use. RESULTS: The study collected a total of 4223 valid questionnaires, and 18.2% of participants reported PrEP use. The results of the standardized total effects showed that the following paths were statistically significant (p < 0.05): from the age of first sex with men to PrEP knowledge awareness (ß = -0.113) and PrEP use (ß = 0.042); from high-risk sexual behaviour scores to PrEP counselling (ß = 0.039) and PrEP use (ß = 0.103); from the number of HIV tests in the last year to PrEP knowledge awareness (ß = 0.034), PrEP counselling (ß = 0.170), and PrEP use (ß = 0.197); from the level of self-perceived risk of HIV infection to PrEP counselling (ß = -0.115); from PrEP knowledge awareness to PrEP use (ß = -0.049); and from PrEP counselling to PrEP use (ß = 0.420). CONCLUSIONS: The proportion of PrEP use among MSM was relatively low. Age at first sex with men, number of HIV tests, high-risk sexual behaviour, and PrEP counselling had a positive effect on PrEP use, whereas PrEP knowledge awareness had an inverse effect on PrEP use.

Arabidopsis transcription factor STOP1 directly activates expression of NOD26-LIKE MAJOR INTRINSIC PROTEIN5;1, and is involved in the regulation of tolerance to low-boron stress.

Transcriptional regulation is a crucial component of plant adaptation to numerous different stresses; however, its role in how plants adapt to low-boron (B) stress remains unclear. In this study, we show that the C2H2-type transcription factor SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) in Arabidopsis is essential for improving plant growth under low-B conditions. STOP1 and the boric acid-channel protein NOD26-LIKE MAJOR INTRINSIC PROTEIN5;1 (NIP5;1) were found to co-localize in root epidermal cells, and STOP1 binds to the 5´-untranslated region of NIP5;1 to activate its expression and enhance B uptake by the roots. Overexpression of STOP1 increased tolerance to low-B stress by up-regulating NIP5;1 transcript levels. Further genetic analyses revealed that STOP1 and NIP5;1 function together in the same pathway to confer low-B tolerance. These results highlight the importance of the STOP1-NIP5;1 module in improving plant growth under low-B conditions.

LincRNA-ROR/miR-145/ZEB2 regulates liver fibrosis by modulating HERC5-mediated p53 ISGylation.

The tumor suppressor p53 has been implicated in the pathogenesis of liver fibrosis. HERC5-mediated posttranslational ISG modification of the p53 protein is critical for controlling its activity. Here, we demonstrated that the expression of HERC5 and ISG15 is highly elevated, whereas p53 is downregulated, in fibrotic liver tissues of mice and transforming growth factor-ß1 (TGF-ß1)-induced LX2 cells. HERC5 siRNA clearly increased the protein expression of p53, but the mRNA expression of p53 was not obviously changed. The inhibition of lincRNA-ROR (ROR) downregulated HERC5 expression and elevated p53 expression in TGF-ß1-stimulated LX-2 cells. Furthermore, the expression of p53 was almost unchanged after TGF-ß1-stimulated LX-2 cells were co-transfected with a ROR-expressing plasmid and HERC5 siRNA. We further confirmed that miR-145 is a target gene of ROR. In addition, we also showed that ROR regulates the HERC5-mediated ISGylation of p53 through mir-145/ZEB2. Together, we propose that ROR/miR-145/ZEB2 might be involved in the course of liver fibrosis by regulating ISGylation of the p53 protein.

Sirtuins in kidney diseases: potential mechanism and therapeutic targets.

Sirtuins, which are NAD+-dependent class III histone deacetylases, are involved in various biological processes, including DNA damage repair, immune inflammation, oxidative stress, mitochondrial homeostasis, autophagy, and apoptosis. Sirtuins are essential regulators of cellular function and organismal health. Increasing evidence suggests that the development of age-related diseases, including kidney diseases, is associated with aberrant expression of sirtuins, and that regulation of sirtuins expression and activity can effectively improve kidney function and delay the progression of kidney disease. In this review, we summarise current studies highlighting the role of sirtuins in renal diseases. First, we discuss sirtuin family members and their main mechanisms of action. We then outline the possible roles of sirtuins in various cell types in kidney diseases. Finally, we summarise the compounds that activate or inhibit sirtuin activity and that consequently ameliorate renal diseases. In conclusion, targeted modulation of sirtuins is a potential therapeutic strategy for kidney diseases. Video Abstract.

MR defecography in assessing stress urinary incontinence with or without symptomatic pelvic organ prolapse.

PURPOSE: Utilize magnetic resonance defecography (MRD) to analyze the primary pelvic floor dysfunctions in patients with stress urinary incontinence (SUI) associated with pelvic organ prolapse (POP), and in SUI patients with asymptomatic POP. METHOD: We performed MRD in both SUI and POP subjects. As a primary analysis, the functional MR parameters were compared between the isolated POP and POP combined SUI groups. As a secondary analysis, the functional MR data were compared between the POP combined SUI and the SUI with asymptomatic POP (isolated SUI) groups. RESULTS: MRD noted the main characteristics of SUI combined moderate or severe POP, including the shorter closed urethra length (1.87 cm vs. 2.50 cm, p < 0.001), more prevalent urethral hypermobility (112.31° vs. 85.67°, p = 0.003), bladder neck funneling (48.28% vs. 20.51%, p = 0.020), lower position of vesicourethral junction (2.11 cm vs. 1.67 cm, p = 0.030), and more severe prolapse of the posterior bladder wall (6.26 cm vs. 4.35 cm, p = 0.008). The isolated SUI patients showed the shortest length of the closed urethra (1.56 cm vs. 1.87 cm, p = 0.029), a larger vesicourethral angle (153.80° vs. 107.58°, p < 0.001), the more positive bladder funneling (84.85% vs. 48.28%, p = 0.002) and a special urethral opening sign (45.45% vs. 3.45%, p < 0.001). CONCLUSIONS: Patients with SUI accompanying POP primarily exhibit excessive urethral mobility and a shortened urethral closure. SUI patients with asymptomatic POP mainly show dysfunction of the urethra and bladder neck, characterized by the opening of the urethra and bladder neck and a shortened urethral closure.

Study on fingerprint and quantitative analysis of Verbena officinalis water extract by LC-MS and HPLC.

Verbena officinalis L. as a medical plant has been used to treat many diseases. However, the quality control underlying V. officinalis remains to be studied. HPLC fingerprint analysis and the qualitative and quantitative analysis of water extract from V. officinalis were carried out, and it was found that the quality varies according to habitat and batch. Verbenalin could be a crucial component in the quality evaluation of V. officinalis. This study contributes to better understanding of quality control for V. officinalis.

Angiographic demonstration of a cutoff sign as an unfavorable prognostic indicator for patients with acute ischemic stroke undergoing mechanical thrombectomy.

OBJECTIVES: The aim was to investigate whether the angiographic demonstration of a cutoff sign on the initial angiogram could predict recanalization and prognosis in acute ischemic stroke patients treated by endovascular thrombectomy. METHODS: The angiographic and clinical data of patients who underwent endovascular treatment from October 2018 to April 2023 were retrospectively reviewed. The pretreatment angiographic appearance of the thrombus's proximal part was assessed and classified as either the cutoff sign (+) or (-). Patients' baseline characteristics and angiographic and clinical outcomes between the two groups were analyzed using propensity score matching. Then, the two commonly used techniques, stent retrieval and contact aspiration, were compared in terms of successful reperfusion and clinical outcome in patients with the cutoff sign. RESULTS: The cutoff sign was observed in 77 (36.2%) of 213 patients. Patients with the cutoff sign were younger and were less likely to have involvement of the anterior circulation. Compared with the cutoff sign (-) group, the cutoff sign (+) group had a significantly longer procedure time (103 versus 80 min, P =0.002) and a lower percentage of 3-month good functional outcomes (18.2% versus 36%, P =0.006). After propensity score matching, the procedure time (100 versus 75 min, P =0.002) and the 3-month good outcome (19.2% versus 41.4%, P =0.004) remained significantly different. No significant differences were observed in the radiological (OR 0.758, 95% CI 0.157 to 3.658; P =0.730) and clinical (OR 0.747, 95% CI 0.147 to 3.787; P =0.725) outcomes between the two techniques. CONCLUSIONS: The cutoff sign might be an unfavorable prognostic indicator in patients undergoing mechanical thrombectomy, and the efficacy of mechanical thrombectomy techniques does not differ in patients positive for the cutoff sign.

Preparation and Application of Volatilized Wormwood Essence Derived Naturally into Green Insecticide.

Naturally occurring substances and their derivatives function as vital resources for pesticides that can be used in fields, such as insecticide production and fungicide development. As a botanical entity displaying multifaceted biological functions, wormwood has received thorough scrutiny across multiple sectors. The insect repellency potency combined with antibacterial and antifungal activities of wormwood position it as a potential candidate for prospective development into eco-friendly chemical pesticides. In this research, Wormwood essential oil was procured via ethanol water under ultrasonic scenarios and subsequently diluted with PEG 400 to formulate green chemical pesticides. The defensive efficacy of this green pesticide on plants was validated through 2 weeks of clustered plant growth experiments. Active constituents that exerted their effects were scrutinized by GC-MS. Furthermore, this green pesticide also displays efficacious effects on the prevention and management of aphids, exhibiting a dose-dependent relationship. 4-terpenol, eucalyptol, carvacrol, and L-borneol were identified by GC-MS as the predominant active constituents in this green chemical pesticide. Wormwood can be leveraged to develop green chemical pesticides, which can protect plants without contaminating the environment.

Anti-aging effect of peptides on Caenorhabditis elegans: a meta-analysis.

BACKGROUND: Recently, peptides have been studied in Caenorhabditis elegans for anti-aging research. Due to the lack of sufficient evidence, we conducted this meta-analysis focusing on the anti-aging effect of peptides in C. elegans to provide more convincing evidence. RESULTS: A literature search in PubMed, SCOUPUS, and Web of Science databases yielded 2879 articles. After removing duplicates and based on inclusion criteria and STAIR checklist quality assessment, nine articles were selected. Data extraction and analysis showed that, compared to the control group without peptide intervention, peptide supplementation significantly reduced nematode mortality risk [hazard ratio = 0.54, 95% confidence interval (CI) = 0.47, 0.62; P < 0.05], significantly increased the pharyngeal pumping rate [standardized mean difference (SMD) = 1.64, 95% CI = 0.87, 2.41; P < 0.05], bending frequency (SMD = 1.67, 95% CI = 1.16, 2.18; P < 0.05), and significantly decreased the accumulation of lipofuscin levels within nematodes (SMD = -4.48, 95% CI = -6.85, -2.12; P < 0.05). Additionally, subgroup analysis showed that doses ranging from 0.1 to 1 mg/mL (HR = 0.50, 95% CI = 0.38, 0.65; P < 0.05) displayed better anti-aging effects compared to other dose ranges. CONCLUSION: The findings suggest that peptides can significantly extend the lifespan of C. elegans under normal circumstances and improve three indicators of healthy life. More importantly, subgroup analysis revealed that a dosage of 0.1-1 mg/mL demonstrated superior anti-aging effects. This meta-analysis provides more convincing evidence that peptides can play an anti-aging role in C. elegans. © 2024 Society of Chemical Industry.

Role of MoOx Surficial Modification in Enhancing the OER Performance of Ru-Pyrochlore.

Pyrochlore ruthenate (Y2 Ru2 O7-δ ) is highlighted as a promising oxygen evolution reaction (OER) catalyst for water splitting in polymer electrolyte membrane electrolyzers. However, an efficient electronic modulation strategy for Y2 Ru2 O7-δ is required to overcome its electrochemical inertness. Herein, a surface manipulation strategy involving implanting MoOx moieties on nano Y2 Ru2 O7-δ (Mo-YRO) using wet chemical peroxone method is demonstrated. In contrast to electronic structure regulation by intramolecular charge transfer (i.e., substitutional strategies), the heterogeneous Mo-O-Ru micro-interfaces facilitate efficient intermolecular electron transfer from [RuO6 ] to MoOx . This eliminates the bandgap by inducing Ru 4d delocalization and band alignment rearrangement. The MoOx modifiers also alleviate distortion of [RuO6 ] by shortening Ru-O bond and enlarging Ru-O-Ru bond angle. This electronic and geometric structure tailoring enhances the OER performance, showing a small overpotential of 240 mV at 10 mA cm-2 . Moreover, the electron-accepting MoOx moieties provide more electronegative surfaces, which serve as a protective "fence" to inhibit the dissolution of metal ions, thereby stabilizing the electrochemical activity. This study offers fresh insights into the design of new-based pyrochlore electrocatalysts, and also highlights the versatility of surface engineering as a way of optimizing electronic structure and catalytic performance of other related materials.

Proteome-wide mendelian randomization study implicates therapeutic targets in common cancers.

BACKGROUND: The interest in targeted cancer therapies has been growing rapidly. While numerous cancer biomarkers and targeted treatment strategies have been developed and employed, there are still significant limitations and challenges in the early diagnosis and targeted treatment of cancers. Accordingly, there is an urgent need to identify novel targets and develop new targeted drugs. METHODS: The study was conducted using combined cis-Mendelian randomization (cis-MR) and colocalization analysis. We analyzed data from 732 plasma proteins to identify potential drug targets associated with eight site-specific cancers. These findings were further validated using the UK Biobank dataset. Then, a protein-protein interaction network was also constructed to examine the interplay between the identified proteins and the targets of existing cancer medications. RESULTS: This MR analysis revealed associations between five plasma proteins and prostate cancer, five with breast cancer, and three with lung cancer. Subsequently, these proteins were classified into four distinct target groups, with a focus on tier 1 and 2 targets due to their higher potential to become drug targets. Our study indicatied that genetically predicted KDELC2 (OR: 0.89, 95% CI 0.86-0.93) and TNFRSF10B (OR: 0.74, 95% CI 0.65-0.83) are inversely associated with prostate cancer. Furthermore, we observed an inverse association between CPNE1 (OR: 0.96, 95% CI 0.94-0.98) and breast cancer, while PDIA3 (OR: 1.19, 95% CI 1.10-1.30) were found to be associated with the risk of breast cancer. In addition, we also propose that SPINT2 (OR: 1.05, 95% CI 1.03-1.06), GSTP1 (OR: 0.82, 95% CI 0.74-0.90), and CTSS (OR: 0.91, 95% CI 0.88-0.95) may serve as potential therapeutic targets in prostate cancer. Similarly, GDI2 (OR: 0.85, 95% CI 0.80-0.91), ISLR2 (OR: 0.87, 95% CI 0.82-0.93), and CTSF (OR: 1.14, 95% CI 1.08-1.21) could potentially be targets for breast cancer. Additionally, we identified SFTPB (OR: 0.93, 95% CI 0.91-0.95), ICAM5 (OR: 0.95, 95% CI 0.93-0.97), and FLRT3 (OR: 1.10, 95% CI 1.05-1.15) as potential targets for lung cancer. Notably, TNFRSF10B, GSTP1, and PDIA3 were found to interact with the target proteins of current medications used in prostate or breast cancer treatment. CONCLUSIONS: This comprehensive analysis has highlighted thirteen plasma proteins with potential roles in three site-specific cancers. Continued research in this area may reveal their therapeutic potential, particularly KDELC2, TNFRSF10B, CPNE1, and PDIA3, paving the way for more effective cancer treatments.

One-Pot Access to Boron-Doped Fused Heterocycles via Domino Cyclization of Bis-Diazidoboranes with Isonitrile.

Boron-doped fused heterocycles have shown great potential in the field of functional materials. This study reports on the synthesis of a new class of bis-diazidoboranes and the discovery of their cycloaddition reaction with isonitriles. Triply fused boron-doped heterocyclic compounds were constructed in a one-pot process through a domino cycloaddition, providing an effective route for constructing complex boron-doped heterocyclic systems.

Distance-Triggered Distinct Aryl Migrations on Azidodiboranes.

Derived from structurally similar precursors, two different azidodiboranes went through distinct aryl migration reactions triggered by different boron-boron separation distances. Biphenylene based diborane with a shorter boron-boron distance underwent heterolateral aryl migration to form a seven-membered azadiborepin, while xanthrene based diborane with a longer boron-boron distance afforded a stable bis-azidoborane scaffold. The pyrolysis of such a bis-azidoborane led to eight-membered oxazadiborocine through homolateral aryl migration and subsequent [3+2] cycloaddition. Density functional theory (DFT) calculations unveiled that the boron-boron separation distances were the intrinsic factors for the distinct migrations.

Neutral Boryl Radicals in Mixed-Valent B(III) Br-B(II) Adducts.

The general strategies to stabilize a boryl radical involve single electron delocalization by π-system and the steric hinderance from bulky groups. Herein, a new class of boryl radicals is reported, with intramolecular mixed-valent B(III) Br-B(II) adducts ligated by a cyclic (alkyl)(amino)carbene (CAAC). The radicals feature a large spin density on the boron center, which is ascertained by EPR spectroscopy and DFT calculations. Structural and computational analyses revealed that the stability of radical species was assisted by the CAAC ligand and a weak but significant B(III)Br-B(II) interaction, suggesting a cooperative avenue for stabilization of boryl radicals. Two-electron reduction of these new boryl radicals provides C-H insertion products via a borylene intermediate.

Amino acids-targeted metabolomics reveals novel diagnostic biomarkers for ulcerative colitis and Crohn's disease.

Inflammatory bowel disease (IBD), which mainly comprises ulcerative colitis (UC) and Crohn's disease (CD), is a common chronic intestinal inflammatory disease that affects the ileum, rectum, and colon. Currently, the diagnosis of IBD is based on clinical history, physical examination and complementary diagnostic tests. It is challenging for physicians to make a definitive diagnosis. This study aimed to analyze the variation in amino acid metabolites in IBD serum and to identify potential predictive biomarkers of IBD diagnosis and progression. Serum samples were collected from 158 UC patients, 130 CD patients and 138 healthy controls (HCs). The 37 amino acids in serum were determined by ultra-high-pressure liquid chromatography coupled to a mass spectrometer. A panel of three-amino-acid metabolites (taurine, homocitrulline and kynurenine) was identified as a specific biomarker panel of IBD. Receiver operating characteristic analysis (ROC) showed that the panel had a sensitivity of 88.4% with a specificity of 84.6% for discriminating CD patients from UC patients. The biomarkers identified are increased in CD compared to UC. Our approach demonstrated a strong relationship between serum amino acid levels and IBD. We successfully identified serum amino acid biomarkers associated with CD and UC. The biomarker panel has potential in clinical practice for IBD diagnosis and will provide new insights into IBD pathogenesis.

The deubiquitinase OTUD1 enhances iron transport and potentiates host antitumor immunity.

Although iron is required for cell proliferation, iron-dependent programmed cell death serves as a critical barrier to tumor growth and metastasis. Emerging evidence suggests that iron-mediated lipid oxidation also facilitates immune eradication of cancer. However, the regulatory mechanisms of iron metabolism in cancer remain unclear. Here we identify OTUD1 as the deubiquitinase of iron-responsive element-binding protein 2 (IREB2), selectively reduced in colorectal cancer. Clinically, downregulation of OTUD1 is highly correlated with poor outcome of cancer. Mechanistically, OTUD1 promotes transferrin receptor protein 1 (TFRC)-mediated iron transportation through deubiquitinating and stabilizing IREB2, leading to increased ROS generation and ferroptosis. Moreover, the presence of OTUD1 promotes the release of damage-associated molecular patterns (DAMPs), which in turn recruits the leukocytes and strengthens host immune response. Reciprocally, depletion of OTUD1 limits tumor-reactive T-cell accumulation and exacerbates colon cancer progression. Our data demonstrate that OTUD1 plays a stimulatory role in iron transportation and highlight the importance of OTUD1-IREB2-TFRC signaling axis in host antitumor immunity.

Investigation of the transport and metabolic patterns of oil-displacing bacterium FY-07-G in the microcosm model using X-CT technology.

AIMS: Microbial enhanced oil recovery (MEOR) is dedicated to enhancing oil recovery by harnessing microbial metabolic activities and their byproducts within reservoir rocks and fluids. Therefore, the investigation of microbial mobility and their extensive distribution within crude oil is of paramount importance in MEOR. While microscale models have been valuable for studying bacterial strain behavior in reservoirs, they are typically limited to 2D representations of porous media, making them inadequate for simulating actual reservoir conditions. Consequently, there is a critical need for 3D models and dependable visualization methods to observe bacterial transport and metabolism within these complex reservoir environments. METHODS AND RESULTS: Bacterial cellulose (bc) is a water-insoluble polysaccharide produced by bacteria that exhibits biocompatibility and biodegradability. It holds significant potential for applications in the field of MEOR as an effective means for selective plugging and spill prevention during oil displacement processes. Conditionally cellulose-producing strain, FY-07-G, with green fluorescent labeling, was engineered for enhanced oil recovery. 3D micro-visualization model was constructed to directly observe the metabolic activities of the target bacterial strain within porous media and to assess the plugging interactions between cellulose and the medium. Additionally, X-ray computed tomography (X-CT) technology was employed for a comprehensive analysis of the transport patterns of the target strain in oil reservoirs with varying permeabilities. The results indicated that FY-07-G, as a microorganism employing biopolymer-based plugging principles to enhance oil recovery, selectively targets and seals regions characterized by lower permeability and smaller pore spaces. CONCLUSIONS: This work provided valuable insights into the transport and metabolic behavior of MEOR strains and tackled the limitation of 2D models in faithfully replicating oil reservoir conditions, offering essential theoretical guidance and insights for the further application of oil-displacing bacterial strains in MEOR processes.

Pre-exposure prophylaxis uptake for high-risk men who have sex with men in China: a multi-city cross-sectional survey.

BACKGROUND: Pre-exposure prophylaxis (PrEP) is a proven biomedical strategy to prevent HIV transmission among men who have sex with men (MSM). Despite oral PrEP is safe and effective in MSM, the use of PrEP has been discouraging, especially in high-risk MSM. And there are no relevant studies showing the use of PrEP in high-risk MSM. The purpose of this study was to get the rate of PrEP use and the factors influencing PrEP use among high-risk MSM. METHODS: A cross-sectional study was conducted through an electronic questionnaire on the "i guardian Platform", and "snowballing" method was used to recruit MSM in six cities in China, including Beijing, Shenzhen, Chengdu, Changsha, Jinan and Nanjing in China, from January to April 2021. Univariate and multivariate logistic regression analysis were used to analyze the factors associated with the use of PrEP among high-risk MSM who had heard about PrEP. RESULTS: Among the 1865 high-risk MSM who had heard of PrEP, the rates of those who were willing to use PrEP, had knowledge awareness of PrEP, and had used PrEP were 96.7%, 24.7%, and 22.4%, respectively. Multivariate logistic regression analysis of PrEP use in high-risk MSM showed that more PrEP was used by those who were 26 years or older (OR = 1.86, 95%CI 1.17 ~ 2.99), had master degree or above (OR = 2.37, 95% CI 1.21 ~ 4.72), had unstable work (OR = 1.86, 95% CI 1.16 ~ 2.96), had tested five or more HIV times in the past year (OR = 3.09, 95% CI 1.65 ~ 6.04), had consulted PrEP (OR = 22.05, 95% CI 14.87 ~ 33.91) and had PrEP knowledge awareness (OR = 1.90, 95% CI 1.41 ~ 2.55) (P < 0.05). CONCLUSIONS: The rate of PrEP use in high-risk MSM was relatively low. PrEP was used more by high-risk MSM with unstable jobs, higher education, frequent HIV testing, and PrEP counseling. Public education on PrEP for MSM should continue to be enhanced to help them use PrEP in a timely and accurate manner.

Nitrogen fixation and transformation with main group elements.

Nitrogen fixation is essential for the maintenance of life and development of society, however, the large bond dissociation energy and nonpolarity of the triple bond constitute a considerable challenge. The transition metals, by virtue of their combination of empty and occupied d orbitals, are prevalent in the nitrogen fixation studies and are continuing to receive a significant focus. The main group metals have always been considered incapable in dinitrogen activation owing to the absence of energetically and symmetrically accessible orbitals. The past decades have witnessed significant breakthroughs in the dinitrogen activation with the main group elements and compounds via either matrix isolation, theoretical calculations or synthetic chemistry. The successful reactions of the low-valent species of the main group elements with inert dinitrogen have been reported via the π back-donation from either the d orbitals (Ca, Sr, Ba) or p orbitals (Be, B, C…). Herein, the significant achievements have been briefly summarized, along with predicting the future developments.