Mechanistic insight into microbial interaction and metabolic pattern of anammox consortia on surface-modified biofilm carrier with extracellular polymeric substances.

The extremely slow growth rate of anaerobic ammonia oxidation (anammox) bacteria limits full-scale application of anammox process worldwide. In this study, extracellular polymeric substances (EPS)-coated polypropylene (PP) carriers were prepared for biofilm formation. The biomass adhesion rate of EPS-PP carrier was 12 times that of PP carrier, and EPS-PP achieved significant enrichment of E. coli BY63. The 120-day continuous flow experiment showed that the EPS-PP carrier accelerated the formation of anammox biofilm, and the nitrogen removal efficiency increased by 10.5 %. In addition, the abundance of Candidatus Kuenenia in EPS-PP biofilm was 27.1%. Simultaneously, amino acids with high synthesis cost and the metabolites of glycerophospholipids related to biofilm formation on EPS-PP biofilm were significantly up-regulated. Therefore, EPS-PP carriers facilitated the rapid formation of anammox biofilm and promoted the metabolic activity of functional bacteria, which further contributed to the environmental and economic sustainability of anammox process.

Case report: Successful management of primary hyalinizing clear cell carcinoma in nasopharynx: a report of 2 cases and system analysis.

Hyalinizing clear cell carcinomas (HCCCs) are infrequent, malignant tumors characterized by their low-grade nature. They typically originate from minor salivary glands. However, these tumors can potentially emerge in any location with minor salivary glands, including the nasopharynx. This report presents two cases of HCCC in females aged 61 and 72 years, with both tumors approximately 4 cm in size. In the first case, a 72-year-old female presented with recurrent bilateral epistaxis. Imaging studies revealed a nasopharyngeal mass, surgically excised, and histopathological analysis confirmed HCCC. Postoperatively, the patient received combined chemotherapy and radiotherapy, achieving a recurrence-free status 2.5 years later. The second case involves a 61-year-old female with a two-year history of bloody nasal discharge. Imaging studies identified a nasopharyngeal lesion, surgically removed, and histopathological examination confirmed HCCC. This patient underwent radiotherapy followed by combination chemotherapy with paclitaxel and carboplatin, displaying no signs of recurrence upon reevaluation after 10 months. These cases highlight the successful management of HCCC through a comprehensive, multimodal approach, integrating surgical intervention and adjuvant therapy. The favorable outcomes emphasize the significance of a thorough treatment strategy for HCCC in the nasopharynx, providing valuable insights for clinicians. Further studies are essential to enhance our understanding of this rare entity and refine treatment protocols for optimized patient outcomes.

Quorum sensing mediated response mechanism of anammox consortia to anionic surfactant: Molecular simulation and molecular evidence.

The widespread use of surfactants raise challenges to biological wastewater treatment. Anaerobic ammonium oxidation (anammox) process has the potential to treat wastewater containing anionic surfactants, but the response of anammox consortia at the molecular level under long-term exposure is unclear. Using high-throughput sequencing and gene quantification, combined with molecular docking, the effect of sodium dodecyl sulfonate (SDS) on anammox consortia were investigated. Levels of reactive oxygen species (ROS) might be lower than the threshold of oxidative damage, while the increase of lactate dehydrogenase (LDH) represented the cell membrane damage. Decreased abundance of functional genes (hdh, hzsA and nirS) indicated the decrease of the anammox bacterial abundance. Trace amounts of N-acyl homoserine lactone (AHL, C6-HSL, C8-HSL and C12-HSL) contained in influent could induce endogenous quorum sensing (QS), which could regulate the correlation between functional bacteria to optimize the microbial community and strengthen the resistance of anammox consortia to SDS. In addition, the proliferation of disinfectant resistance genes might increase the environmental pathogenicity of sewage discharge. This work highlights the potential response mechanism of anammox consortium to surfactants and provides a universal microbial-friendly bioenhancement strategy based on QS.

Experimental and Computational Study Toward Identifying Active Sites of Supported SnOx Nanoparticles for Electrochemical CO2 Reduction Using Machine-Learned Interatomic Potentials.

SnOx has received great attention as an electrocatalyst for CO2 reduction reaction (CO2RR), however; it still suffers from low activity. Moreover, the atomic-level SnOx structure and the nature of the active sites are still ambiguous due to the dynamism of surface structure and difficulty in structure characterization under electrochemical conditions. Herein, CO2RR performance is enhanced by supporting SnO2 nanoparticles on two common supports, vulcan carbon and TiO2. Then, electrolysis of CO2 at various temperatures in a neutral electrolyte reveals that the application window for this catalyst is between 12 and 30 °C. Furthermore, this study introduces a machine learning interatomic potential method for the atomistic simulation to investigate SnO2 reduction and establish a correlation between SnOx structures and their CO2RR performance. In addition, selectivity is analyzed computationally with density functional theory simulations to identify the key differences between the binding energies of *H and *CO2 -, where both are correlated with the presence of oxygen on the nanoparticle surface. This study offers in-depth insights into the rational design and application of SnOx-based electrocatalysts for CO2RR.

Association of human leukocyte antigen-G and -F with recurrent miscarriage and implantation failure: A systematic review and meta-analysis.

PROBLEM: The immune system plays an essential role in embryonic implantation and pregnancy, but the molecular details remain controversial. In the past four decades, human leukocyte antigen (HLA)-G and -F have garnered significant attention. METHOD OF STUDY: MEDLINE, EMBASE, Web of Science, and the Cochrane Trials Registry were searched from their inception dates until December 2022. Studies were selected following PRISMA guidelines. Meta-analyses were used to assess the relationship of soluble HLA-G (sHLA-G) and HLA-G 3'-untranslated region polymorphisms with recurrent miscarriage (RM) and recurrent implantation failure (RIF). Narrative synthesis was conducted to determine the association of RM with other single nucleotide polymorphisms (SNPs) and HLA-G protein in tissues and of RIF with HLA-F. Risk-of-bias was assessed using ROBINS-I. Publication bias was assessed using Egger's and Begg's tests. RESULTS: Finally, 42 articles were eligible for inclusion in the systematic review (32 in the meta-analysis; 13 in narrative synthesis). We found a significant association between the 14-bp ins/del HLA-G polymorphism and RM risk, but no definitive association with RIF risk. Women with RM had lower blood concentrations of sHLA-G during pregnancy and non-pregnancy than did controls. For women in the RIF group, no significant difference was found. CONCLUSION: HLA-G protein and gene expression levels may be closely related to RM. The relevance of HLA-G to RIF is still being determined. A narrative synthesis of current studies has shown that HLA-F is likely associated with RIF.

Bushen Huoxue formula for the treatment of diminished ovarian reserve: A combined metabolomics and integrated network pharmacology analysis.

Objective: This study aimed to explore the mechanism of the Bushen Huoxue Formula (BHF) in treating diminished ovarian reserve (DOR) through the use of metabolomics and integrated network pharmacology. Methods: The study involved 24 non-pregnant female Sprague-Dawley rats, divided into four groups of six rats each: control, model, BHF, and DHEA (n = 6 per group). The model group was induced with DOR by administering Tripterygium glycosides orally [50 mg (kg·d)-1] for 14 days. Subsequently, BHF and Dehydroepiandrosterone (DHEA) treatments were given to the respective groups. Ovarian reserve function was assessed by measuring anti-Müllerian hormone (AMH), estradiol (E2), and follicle-stimulating hormone (FSH) levels and conducting hematoxylin-eosin staining. In addition, UHPLC-QTOF-MS analysis was performed to identify differential metabolites and pathways in DOR rats treated with BHF. In this study, LC-MS was utilized to identify the active ingredients of BHF, while network pharmacology was employed to investigate the correlations between BHF-related genes and DOR-related genes. An integrated analysis of metabonomics and network pharmacology was conducted to elucidate the mechanisms underlying the efficacy of BHF in treating DOR. Results: The model group exhibited a poor general condition and a significant decrease in the number of primordial, primary, and secondary follicles (P < 0.05) when compared to the control group. However, BHF intervention resulted in an increase in the number of primordial, primary, and secondary follicles (P < 0.05), along with elevated levels of AMH and E2 (P < 0.05), and a decrease in FSH levels (P < 0.05) in DOR rats. The modeling process identified eleven classes of metabolites, including cholesterol esters (CE), diacylglycerols (DAG), hexosylceramides (HCER), lysophosphatidylcholines (LPC), phosphatidylcholines (PC), phosphatidylethanolamines (PE), sphingomyelins (SM), ceramides (CER), free fatty acids (FFA), triacylglycerols (TAG), and lysophosphatidylethanolamines (LPE). The study found that PC, CE, DAG, and TAG are important metabolites in the treatment of DOR with BHF. LC-MS analysis showed that there were 183 active ingredients in ESI(+) mode and 51 in ESI(-) mode. Network pharmacology analysis identified 285 potential genes associated with BHF treatment for DOR in ESI(+) mode and 177 in ESI(-) mode. The combined analysis indicated that linoleic acid metabolism is the primary pathway in treating DOR with BHF. Conclusion: BHF was found to improve ovarian function in rats with DOR induced by Tripterygium glycosides. The study identified key metabolites such as phosphatidylcholine (PC), cholesteryl ester (CE), diacylglycerol (DAG), triacylglycerol (TAG), and the linoleic acid metabolism pathway, which were crucial in improving ovarian function in DOR rats treated with BHF.

Discovery, traceability, formation mechanism, metal and organic components analysis of supramolecules from Maxing Shigan decoction.

Traditional Chinese medicine (TCM) decoction is a complex polydispersed phase system containing colloid solution, emulsion and suspension, which maybe induced by the supramolecular phenomenon in decoction. However, until now there is no systematic analysis of composition and formation mechanism of supramolecules in TCM decoction contained mineral drug and herb medicines. Maxing Shigan Decoction (MXSGT), one of the classic TCM recipes, has been widely used in the treatment of fever in clinic. In this study, we obtained the supramolecular part of MXSGT (MXSGT NPs). And its traceability, formation mechanism, metal and organic components were further analyzed. The morphology was characterized by scanning electron microscopy (SEM) and dynamic light scattering (DLS); and the lipopolysaccharides (LPS) induced rats' fever model was established to evaluate the antipyretic effect of MXSGT NPs. Furthermore, interaction of the disassembled groups was studied to explore the traceability and formation mechanism of MXSGT NPs by isothermal titration calorimeter (ITC). Due to the combination of mineral gypsum and herb medicines, both ICP-OES and UHPLC-Q-Orbitrap HRMS were used to analyze metal and organic components of MXSGT and MXSGT NPs, respectively. The results showed that MXSGT NPs was regular spherical nanoparticles and had the same antipyretic effect as MXSGT. Moreover, MXSGT NPs was formed by the interaction between metal and organic components, resulted in enriching the main active compounds of MXSGT. This study would provide a new idea of studying TCM decoction, especially clarifying the connotation with the participation of mineral gypsum.

Superaerophilic/superaerophobic cooperative electrode for efficient hydrogen evolution reaction via enhanced mass transfer.

Hydrogen evolution reaction (HER), as an effective method to produce green hydrogen, is greatly impeded by inefficient mass transfer, i.e., bubble adhesion on electrode, bubble dispersion in the vicinity of electrode, and poor dissolved H2 diffusion, which results in blocked electrocatalytic area and large H2 concentration overpotential. Here, we report a superaerophilic/superaerophobic (SAL/SAB) cooperative electrode to efficiently promote bubble transfer by asymmetric Laplace pressure and accelerate dissolved H2 diffusion through reducing diffusion distance. Benefiting from the enhanced mass transfer, the overpotential for the SAL/SAB cooperative electrode at -10 mA cm-2 is only -19 mV, compared to -61 mV on the flat Pt electrode. By optimizing H2SO4 concentration, the SAL/SAB cooperative electrode can achieve ultrahigh current density (-1867 mA cm-2) at an overpotential of -500 mV. We can envision that the SAL/SAB cooperative strategy is an effective method to improve HER efficiency and stimulate the understanding of various gas-involved processes.

[Regulatory effect of five-element music therapy of traditional Chinese medicine for suboptimal health status of liver stagnation and spleen deficiency based on the temperature changes of acupoints].

OBJECTIVE: To observe the effect of five-element music therapy of traditional Chinese medicine (TCM) on the clinical symptoms and the quality of life in the patients with suboptimal health status (SHS) of liver stagnation and spleen deficiency and explore the corresponding specificity changes in the temperature of acupoints when zangfu functions are of dysfunction and recovered to be balanced, separately. METHODS: Sixty patients with SHS of liver stagnation and spleen deficiency were randomized into an observation group and a control group, 30 cases in each one. In the control group, the conventional health education was provided. In the observation group, on the base of the therapeutic regimen as the control group, the patients received the five-element music therapy to pacify the liver qi and strengthen the spleen functions, once every two days, 30 min each time, 3 treatments a week. The course of treatment consisted of 4 weeks. Before and after treatment, the TCM syndrome score and the MOS 36-item short form healthy survey (SF-36) score were compared between the two groups and the clinical therapeutic effect was evaluated. Using infrared thermal imaging, the temperature at the acupoints of the affected organs (liver, spleen), the related organs (gallbladder, stomach) and the other non-related zangfu organs (pericardium, lung) was detected before and after treatment in the two groups. RESULTS: After treatment, the TCM syndrome scores were reduced when compared with those before treatment in the two groups (P<0.01, P<0.05); the reduction in the observation group was larger than that of the control group (P<0.01). The score of each domain for the SF-36 in the observation group and the score of role-emotional domain in the control group were all increased when compared with the scores before treatment (P<0.01, P<0.05); and the score of each domain for the SF-36 in the observation group was higher than that in the control group (P<0.01). The total effective rate was 66.7% (20/30) in the observation group, which was higher than 10.0% in the control group (3/30, P<0.05). In the observation group, the temperature of the yuan-primary point, the back-shu point and the front-mu point related to the liver, as well as those related to the gallbladder after treatment was reduced when compared with the temperature before treatment; and the changes were larger than those of the control group (P<0.01). The temperature of the yuan-primary point, the back-shu point and the front-mu point related to the spleen, as well as the back-shu point and the front-mu point related to the stomach in the observation group was increased when compared with the temperature before treatment (P<0.01); and the changes were larger than those of the control group (P<0.01). For the temperature of the non-specific points related to the liver and spleen, as well as the yuan-primary point, the back-shu point and the front-mu point related to the pericardium and the lung, there was no significant differences when compared with the temperature at the above-mentioned acupoints before and after treatment (P>0.05). CONCLUSION: TCM five-element music therapy associated with the conventional health education may effectively relieve the clinical symptoms and improve the quality of life in the patients with suboptimal health status of liver stagnation and sleep deficiency; and the therapeutic effect is better than the simple health education. The changes in the temperature of acupoints may reflect the functional regulation of the related zangfu organs in the body.

Multi-functional self-assembly nanoparticles originating from small molecule natural product for oral insulin delivery through modulating tight junctions.

BACKGROUND: Oral administration of insulin (INS) could be absorbed into systemic circulation only if the carrier protected it from the hostile gastrointestinal conditions. However, traditional macromolecular carriers have not totally overcome challenges in addressing these biological barriers. RESULT: In this study, inspired by small molecule natural products (SMNPs), we demonstrate the multi-functional self-assembly nanoparticles (BA-Al NPs) originating from baicalin (BA) and AlCl3 through coordination bonds and hydrogen bonds. As a novel carrier for oral insulin delivery (INS@BA-Al NPs), it displayed effective capacity in pH stimuli-responsive insulin release, intestinal mucoadhesion and transepithelial absorption enhance. Meanwhile, BA improved the paracellular permeability for insulin absorption, because of its downregulation at both mRNA and protein level on internal tight junction proteins. In vivo experiments exhibited remarkable bioavailability of INS and an ideal glucose homeostasis in the type I diabetic rat model. CONCLUSION: This study offers a novel frontier of multi-functional carriers based on SMNPs with self-assembly character and bioactivity, which could be a promising strategy for diabetes therapy.

Estimation of moisture migration in rammed earth based on entropy theory.

In the field of cultural relic protection, the migration of moisture will cause a series of adverse effects, such as disruption and crater eruption. Assessment of water migration status is the key to early warning and prevention of these problems. In an attempt for a solution, the whole process of moisture migration in rammed earth is studied by using the moisture migration initiation criterion based on entropy. We analyzed and compared the entropy change law of the infrared radiation temperature in the two main migration stages, and we made a judgment on whether the moisture state is in the steady equilibrium or in the process of dynamic migration. The results show that the moisture migration status can be identified quickly and in real time by using the moisture migration initiation criterion based on entropy. The results of this study provide a new method for judging the state of moisture migration in geotechnical engineering, especially in the field of cultural relic protection, which has very important practical significance.

Alveolar bone loss with microarchitecture changes in aged rat / Pérdida ósea alveolar con alteraciones en la microarquitectura en ratas envejecidas

SUMMARY: The aim of the present study was to evaluate the changes of alveolar bone in aged rats. The mandibles of the 4- month and 22-month aged rats were scanned by micro-CT. After the reconstruction of the alveolar bone,the distance between the cemento enamel junction (CEJ) and the alveolar bone crest (ABC) was measured. The micro architectures of the inter-radicular alveolar bone were analyzed. The 22-month rats experienced the reduction in alveolar crest height in the buccal side and the lingual side, and significant increase in alveolar bone loss compared with the 4-month rats. The 22-month rats had a porous microarchitecture, the trabecular arrangement was obviously dissociated with the expanded inter-bone spaces of marrow, and the bone histomorphometry analysis showed the decreased bone volume/tissue volume and trabecular thickness in the 22-month rats. These results suggest that alveolar bone loss and alveolar trabecular bone deterioration might contribute to the weakening of molar support in the elderly.

RESUMEN: El objetivo del presente estudio fue evaluar los cambios del hueso alveolar en ratas envejecidas. Las mandíbulas de las ratas de 4 y 22 meses se escanearon mediante micro-TC. Después de la reconstrucción del hueso alveolar, se midió la distancia entre la unión cementoesmalte (CEJ) y la cresta ósea alveolar (ABC). Se analizaron las microarquitecturas del hueso alveolar interradicular. Las ratas de 22 meses experimentaron la reducción de la altura de la cresta alveolar. en el lado bucal y lingual, y un aumento significativo en la pérdida de hueso alveolar en comparación con las ratas de 4 meses. Las ratas de 22 meses tenían una microarquitectura porosa, la disposición trabecular estaba obviamente disociada con los espacios interóseos expandidos de la médula y el análisis de histomorfometría ósea mostró una disminución del volumen óseo / volumen tisular y del grosor trabecular en las ratas de 22 meses. Estos resultados sugieren que la pérdida ósea alveolar y el deterioro del hueso trabecular alveolar podrían contribuir al debilitamiento del soporte molar en los ancianos.

Impact of the COVID-19 Pandemic on the Mental Health of College Students: A Systematic Review and Meta-Analysis.

BACKGROUND: The coronavirus disease (COVID-19) pandemic has been spreading and brought unprecedented psychological pressure on people across the entire globe since December 2019. OBJECTIVES: To synthesize the existing evidence of the prevalence of mental health status during the epidemic and provide the basis for mental health education. MATERIALS AND METHODS: The literature search was conducted in nine databases from December 2019 to October 2020. The risk of bias for each study was assessed, and the random-effects meta-analysis was used to estimate the prevalence of specific mental health problems. The review protocol was registered in PROSPERO with the registration number CRD42020208619. RESULTS: About 27 studies were included in the analysis with a total of 706,415 participants combined, and 14 mental health problems were gathered. Meta-analysis showed that the prevalence of depression was 39% (95% CI: 27-51%) and that of anxiety was 36% (95% CI: 26-46%). Subgroup analysis indicated that the prevalence of depression and anxiety varied among nations and due to the survey date. The prevalence of depression (60%, 95% CI: 46-74%) and anxiety (60%, 95% CI: 46-74%) in non-Chinese college students was higher than those in Chinese college students (26%, 95% CI: 21-30% and 20%, 95% CI: 14-26%). The proportion of depression (54%, 95% CI: 40-67%) and anxiety (37%, 95% CI: 26-48%) was higher after March 1 than before it (21%, 95% CI: 16-25% and 19%, 95% CI: 13-25%). CONCLUSIONS: The meta-analysis results presented that the prevalence of depression (39%) or anxiety (36%) among college students greatly increased during the COVID-19 pandemic. In addition, the mental health of college students is affected by the nations and the survey date. It was necessary to take measures to reduce mental health risks during the pandemic.

Revealing the Toxicity-Enhancing Essence of Glycyrrhiza on Genkwa Flos Based on Ultra-high-performance Liquid Chromatography Coupled With Quadrupole-Orbitrap High-Resolution Mass Spectrometry and Self-Assembled Supramolecular Technology.

Researchers often focus on the mechanisms of synergistic agents, a few explore drug combinations that enhance toxicity, while few have studied the internal mechanism of compatibility enhancement in chemical level. Herein, we present a comprehensive analysis based on ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) and a self-assembled supramolecular strategy, which reveals the toxicity-enhancing essence of glycyrrhizic acid originated in licorice when combined with Genkwa Flos. Through this method, we discovered the toxicity was enhanced through the formation of a supramolecular complex from Genkwa Flos/glycyrrhizic acid. The morphology and size distribution of the self-assembled nanoparticles were characterized by scanning electron microscopy and dynamic light scattering Furthermore, a total of 58 constituents (eight diterpenoids, 35 flavonoids, five phenylpropanoids, four nucleosides, two amino acids, and four other compounds) consisted from the supramolecular complex were identified through accurate-mass measurements in full-scan MS/data-dependent MS/MS mode. Based on the hydrophobic interaction of glycyrrhizic acid with yuanhuacine (one of main ingredients from Genkwa Flos), the supramolecular self-assembly mechanism was revealed with proton nuclear magnetic resonance (1H-NMR) and NOESY 2D NMR. The toxicity of Genkwa Flos and Genkwa Flos/glycyrrhizic acid supramolecular complex were compared through in vitro studies on L-02 cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; and 4',6-diamidino-2-phenylindole (DAPI) staining was performed to further confirm the enhancement inhibition of Genkwa Flos/glycyrrhizic acid supramolecular complex than Genkwa Flos. This study provides fundamental scientific evidence of the formation of a self-assembled phytochemical supramolecular when Genkwa Flos and glycyrrhizic acid are combined, enabling to understand their clinical incompatibility and contraindication.

Self-Assembled Nanoparticles of Natural Phytochemicals (Berberine and 3,4,5-Methoxycinnamic Acid) Originated from Traditional Chinese Medicine for Inhibiting Multidrug-Resistant Staphylococcus aureus.

BACKGROUND: In the field of antibacterial, nanomaterials are favored by researchers because of their unique advantages. Medicinal plants, especially traditional Chinese medicine, are considered to be an important source of new chemicals with potential therapeutic effects, as well as an important source for the discovery of new antibiotics. MRSA is endangering people's lives as a kind of multidrug-resistant Staphylococcus aureus, which is resistant to tetracycline, amoxicillin, norfloxacin and other first-line antibiotics. It is a hotspot to find good anti-drug-resistant bacteriae, nature-originated nanomaterials with good biocompatibility. OBJECTIVE: We reported the formation of phytochemical nanoparticles (NPs) by the self-assembly of berberine (BBR) and 3,4,5-methoxycinnamic acid (3,4,5-TCA) from Chinese herb medicine, which had good antibacterial activity against MRSA. METHODS AND RESULTS: We found that NPs had good antibacterial activity against MRSA; especially, its antibacterial activity was better than first-line amoxicillin, norfloxacin and its self-assembling precursors on MRSA. When the concentration reached 0.1 µmol/mL, the inhibition rate of NPs reached 94.62%, which was higher than that of BBR and the other two antibiotics (p < 0.001). It was observed by Field-Emission Scanning Electron Microscopy (FESEM) that NPs could directly adhere to the bacterial surface, which might be an important aspect of the antibacterial activity of NPs. Meanwhile, we further analyzed that the self-assembly was formed by hydrogen bonds and π-π stacking through Ultraviolet-Visible (UV-vis), Fourier Transform Infrared Spectroscopy (FTIR), hydrogen Nuclear Magnetic Spectrum (1H NMR), and powder X-ray Diffraction (pXRD). NPs' morphology was observed by FESEM and TEM. The particle size and surface charge were characterized by Dynamic Light Scattering (DLS); and the surface charge was -31.6 mv, which proved that the synthesized NPs were stable. CONCLUSION: We successfully constructed a naturally self-assembled nanoparticle, originating from traditional Chinese medicine, which had a good antibacterial activity for MRSA. It is a promising way to obtain natural nanoparticles from medicinal plants and apply them to antibacterial therapy.

Betulinic Acid-Nitrogen Heterocyclic Derivatives: Design, Synthesis, and Antitumor Evaluation in Vitro.

Betulinic acid (BA) is a star member of the pentacyclic triterpenoid family, which exhibits great prospects for antitumor drug development. In an attempt to develop novel antitumor candidates, 21 BA-nitrogen heterocyclic derivatives were synthetized, in addition to four intermediates, 23 of which were first reported. Moreover, they were screened for in-vitro cytotoxicity against four tumor cell lines (Hela, HepG-2, BGC-823 and SK-SY5Y) by a standard methylthiazol tetrazolium (MTT) assay. The majority of these derivatives showed much stronger cytotoxic activity than BA. Remarkably, the most potent compound 7e (the half maximal inhibitory concentration (IC50) of which was 2.05 ± 0.66 µM) was 12-fold more toxic in vitro than BA-treated Hela. Furthermore, multiple fluorescent staining techniques and flow cytometry collectively revealed that compound 7e could induce the early apoptosis of Hela cells. Structure-activity relationships were also briefly discussed. The present study highlighted the importance of introducing nitrogen heterocyclic rings into betulinic acid in the discovery and development of novel antitumor agents.

Canopy Nitrogen Concentration Monitoring Techniques of Summer Corn Based on Canopy Spectral Information.

Crop nitrogen monitoring techniques, particularly choosing sensitive monitoring bands and suitable monitoring models, have great significance both in theory and in practice for achieving non-destructive monitoring of nitrogen concentration and accurate management of water and fertilizer in large-scale areas. In this study, a lysimeter experiment was carried out to examine the characteristics of canopy spectral reflectance variation of summer corn under different fertilization levels. The relationship between canopy spectral reflectance and nitrogen concentration was investigated, based on which sensitive bands for the corn canopy nitrogen monitoring were selected and a suitable spectral index model was determined. The results suggest that under different fertilization levels, the canopy spectral reflectance of summer corn decreases with the increase of the canopy nitrogen concentration in the visible light band, but varies in the opposite direction in the near-infrared band, with a premium put on a higher correlation between the spectral reflectance of the characteristic bands and their first derivatives and the canopy nitrogen concentration. The most sensitive bands for monitoring the canopy nitrogen concentration using spectral reflectance and its first derivative are found to be 762 nm and 726 nm and the correlation coefficients are 0.550 and 0.795, respectively. The optimal band combination, generated by multivariate stepwise regression analysis, is composed of 762 nm, 944 nm and 957 nm bands. From the 55 reported spectral index models of crop nitrogen concentration monitoring, the most suitable index model, NDRE, is chosen such that this index model has the highest correlation with the canopy nitrogen concentration in summer corn. This model has a significant positive correlation with the canopy nitrogen concentration at each growth period, and the correlation coefficient is up to 0.738 during the whole growth period. Spectral monitoring models of canopy nitrogen concentration are constructed using sensitive bands, and a combination of bands and the spectral index, suggesting that these models perform well in monitoring. The models arranged in descending order of simulation accuracy are as follows: the suitable spectral index model, the optimal band combination model, the sensitive band reflectance first derivative model, the sensitive band reflectance model. The determination coefficients are 0.754, 0.711, 0.639 and 0.306, respectively.

Highly efficient and stable solar-powered desalination by tungsten carbide nanoarray film with sandwich wettability.

Solar-powered desalination is a promising way to resolve the worldwide water crisis for its low consumption and simple facility. Considering the fragility and aggregations of traditional materials, which may decrease efficiency, we herein introduce a robust tungsten carbide (WC) nanoarray film as a stable and efficient photothermal material, whose absorption is over 97.5% throughout almost the whole solar spectrum range (220-2200 nm) due to nanoarray structure and thus enhanced localized surface plasmon resonance. Besides, for the first time, we modified the film with sandwich wettability. It accelerates evaporation by reducing water's reflection of light, enlarging hydrophobic-hydrophilic boundaries, and depressing heat dissipation. Combining high absorption with unique wettability, the WC nanoarray film offers high solar-to-vapor efficiency of 90.8% and produces drinking water at the rate of (1.06 ±â€¯0.10) kg m-2 h-1 from man-made seawater and (0.98 ±â€¯0.18) kg m-2 h-1 from heavy metal sewage under one sun (AM 1.5) while 98% performance remains after 1 h × 100 times' reutilization.

Nitrogen-doped tungsten carbide nanoarray as an efficient bifunctional electrocatalyst for water splitting in acid.

Tungsten carbide is one of the most promising electrocatalysts for the hydrogen evolution reaction, although it exhibits sluggish kinetics due to a strong tungsten-hydrogen bond. In addition, tungsten carbide's catalytic activity toward the oxygen evolution reaction has yet to be reported. Here, we introduce a superaerophobic nitrogen-doped tungsten carbide nanoarray electrode exhibiting high stability and activity toward hydrogen evolution reaction as well as driving oxygen evolution efficiently in acid. Nitrogen-doping and nanoarray structure accelerate hydrogen gas release from the electrode, realizing a current density of -200 mA cm-2 at the potential of -190 mV vs. reversible hydrogen electrode, which manifest one of the best non-noble metal catalysts for hydrogen evolution reaction. Under acidic conditions (0.5 M sulfuric acid), water splitting catalyzed by nitrogen-doped tungsten carbide nanoarray starts from about 1.4 V, and outperforms most other water splitting catalysts.

The role of Snf5 in the osteogenic differentiation potential during replicative senescence of rat mesenchymal stromal cells.

The osteogenic capacities of bone marrow-derived stromal cells (BMSCs) diminish during replicative senescence, and these changes affect the success of therapeutic application of BMSCs. In this study, we sought to explore the molecular mechanisms underlying the osteogenic differentiation capacities that occur during replicative senescence. It is well known that Oct4 is a key transcription factor essential for maintaining differentiation capacities of the stem cells. In this study, we found that BMSCs at passage 6 (replicative senescent BMSCs) showed marked decreases in the osteogenic differentiation potential and the level of Oct4. These were accompanied by reduced levels of Snf5 and histone H3 lysine-4 trimethylation (H3K4me3) in the Oct4 promoter. In BMSCs at passage 2, knockdown of Snf5 diminished expression of Oct4 and disrupted the up-regulation of alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2) after osteogenic differentiation induction, which was accompanied by a reduction in Snf5 and H3K4me3 binding to the Oct4 promoter. These findings indicate that the decreased level of Snf5 binding to the promoter region of the Oct4 gene down-regulated the expression of Oct4, which may be the mechanism underlying the decline in osteogenic capacities in replicative senescent BMSCs.