713 research outputs found

    Proline-Based Boronic Acid Receptors for Chiral Recognition of Glucose

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    Chiral recognition remains a major challenge in the area of molecular receptor design. With this research, we set out to explore the use of proline-based receptors for chiral recognition. Importantly, the proline structure allows for the introduction of at least two different binding groups due to the availability of both an amine and carboxylic acid group. Here we report a proof-of-concept exploration into the chiral recognition of d/l-glucose as a model chiral species, which prefers to bind to at least two boronic acid groups. We evaluated several proline-based receptors incorporating two phenylboronic acid groups, respectively, at the N- and C-termini of the amino acid residue, via amide bonds. We confirmed that the receptors exhibited chiral recognition using CD, 1H NMR, and 19F NMR spectroscopy. Given the derivation diversity available, our strategy to use proline-based receptors for chiral recognition holds significant promise for extension to other chiral systems. </p

    Associations between impulsivity, aggression, and suicide in Chinese college students

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    BACKGROUND: Although there are accumulating data regarding the epidemiology of suicide in China, there are meager data on suicidal ideation and attempts among college students. Interestingly, elevated impulsivity is thought to facilitate the transition from suicidal thoughts to suicidal behavior. Therefore, the objective of this research was to identify the associations between suicide and the personality factors of impulsivity and aggression. METHODS: This study’s sampling method employed stratified random cluster sampling. A multi-stage stratified sampling procedure was used to select participants (n = 5,245). We conducted structured interviews regarding a range of socio-demographic characteristics and suicidal morbidity. The Patient Health Questionnaire depression module (PHQ-9) was used to acquire the information about thoughts of being better off dead or hurting themselves in some ways during the past two weeks. The impulsivity symptoms in this study were assessed with the BIS-11-CH (i.e., the Chinese version of the BIS-11), and the Aggressive symptoms were assessed with the BAQ. The statistical package for social science (SPSS) v.13.0 program (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Socio-demographic variables such as ethnic and gender were compared between groups, through the use of χ(2) tests. The nonparametric test (k Independent Sample test, Kruskal-Wallis H) was performed to determine differences between the personality factors of impulsivity and aggression and suicide. RESULTS: In total, 9.1% (n = 479) of the 5,245 students reported they have ever thought about committing suicide; and 1% (n = 51) reported a history of attempted suicide (attempters). The analyses detected significant differences in scores on cognitive impulsivity (p < 0.01), when comparing individuals who only had suicidal ideation and individuals who had attempted suicide. Moreover, significant differences were found between ideators only and attempters on scores of self-oriented attack (p < .001). CONCLUSIONS: Suicidal ideation is prevalent among Chinese university students. Students with high aggression scores were more susceptible to committing suicide. Scores on self-oriented attack and cognitive impulsivity may be important factors for differentially predicting suicide ideation and suicide attempts

    Investigation of He’s Yang Chao recipe against oxidative stress-related mitophagy and pyroptosis to improve ovarian function

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    BackgroundPrimary ovarian insufficiency (POI) is a common gynecological disease with serious ramifications including low pregnancy rate and low estrogen symptoms. Traditional Chinese medicine is regarded as an effective treatment for POI. However, the therapeutic mechanism of it is unclear.MethodsIn this study, a mouse model of primary ovarian insufficiency was established by intraperitoneal injection of cyclophosphamide (CTX) and He’s Yang Chao Recipe (HSYC) concentrate was used for intragastric administration. Serum hormone levels (Anti-Müllerian Hormone, Estradiol, Progesterone, Luteinizing Hormone and Follicle Stimulating Hormone) and Oxidative Stress (OS) related products, superoxide dismutase (SOD), GSH-Px, and malondialdehyde (MDA) were measured by enzyme-linked immunosorbent assay. Pathological changes in ovarian tissue were evaluated by hematoxylin and eosin staining, and flow cytometry was used to determine reactive oxygen species content and mitochondrial membrane potential levels in granulosa cells. Mitochondrial distribution and morphology were investigated using immunofluorescence staining. The level of mitophagy was evaluated by LC3 immunofluorescence staining and autophagosome counts using electron microscopy. Western blotting and qPCR were used to detect the expression of proteins and genes related to mitophagy and the NLRP3 inflammasome.ResultsAfter HSYC treatment, the ovarian damage was milder than in the CTX group. Compared with the CTX group; SOD, GSH-Px, and the total antioxidant capacity were significantly increased, while MDA and ROS were decreased in the HSYC treatment groups. Furthermore, mitochondrial distribution and membrane potential levels were improved after HSYC treatment compared to the CTX group. After the HSYC treatment, the LC3 fluorescent intensity and autophagosome counts were decreased. Similarly, mitophagy related markers PINK1, Parkin, LC3, and Beclin1 were decreased, while p62 was significantly increased, compared with the CTX groups. The mRNA and protein expression of NLRP3 inflammasome, NLRP3, caspase-1, GSDMD, IL-18, and IL-1β were significantly decreased in the HSYC treatment groups.ConclusionThis is the first study in molecular mechanisms underlying HSYC against granulosa cell injury in POI. HSYC protects ovaries from CTX-induced ovarian damage and oxidative stress. HSYC enhanced ovarian function in mice with primary ovarian insufficiency by inhibiting PINK1-Parkin mitophagy and NLRP3 inflammasome activation

    Nivolumab in Advanced Hepatocellular Carcinoma: Safety Profile and Select Treatment-Related Adverse Events From the CheckMate 040 Study.

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    BACKGROUND: CheckMate 040 assessed the efficacy and safety of nivolumab in patients with advanced hepatocellular carcinoma (HCC). Understanding the safety profile of nivolumab is needed to support the management of treatment-related adverse events (TRAEs). This analysis assessed the safety of nivolumab monotherapy in the phase I/II, open-label CheckMate 040 study. MATERIALS AND METHODS: Select TRAEs (sTRAEs; TRAEs with potential immunologic etiology requiring more frequent monitoring) occurring between first dose and 30 days after last dose were analyzed in patients in the dose-escalation and -expansion phases. Time to onset (TTO), time to resolution (TTR), and recurrence of sTRAEs were assessed, and the outcome of treatment with immune-modulating medication (IMM) was evaluated. RESULTS: The analysis included 262 patients. The most common sTRAE was skin (35.5%), followed by gastrointestinal (14.5%) and hepatic (14.1%) events; the majority were grade 1/2, with 10.7% of patients experiencing grade 3/4 events. One patient had grade 5 pneumonitis. Median (range) TTO ranged from 3.6 (0.1-59.9) weeks for skin sTRAEs to 47.6 (47.1-48.0) weeks for renal sTRAEs. Overall, 68% of sTRAEs resolved, with median (range) TTR ranging from 3.7 (0.1-123.3+) weeks for gastrointestinal sTRAEs to 28.4 (0.1-79.1) weeks for endocrine sTRAEs. Most gastrointestinal and all hepatic events resolved with treatment in accordance with established toxicity management algorithms. In 57 patients (40%), sTRAEs were managed with IMM. Reoccurrence of sTRAEs was uncommon following rechallenge with nivolumab. CONCLUSION: Nivolumab demonstrated a manageable safety profile in this analysis of patients with advanced HCC. A majority of sTRAEs resolved with treatment. IMPLICATIONS FOR PRACTICE: Nivolumab is a viable treatment option for patients with previously treated advanced hepatocellular carcinoma as it has demonstrated durable tumor responses and promising survival. Nivolumab has a manageable safety profile. The most common select treatment-related adverse events (sTRAEs) in this analysis were skin related (35%). Gastrointestinal and hepatic sTRAEs were observed in approximately 14% of patients. The majority of sTRAEs resolved (68%). Safety events are easier to manage if addressed early. Patient education on signs and symptoms to watch out for and the importance of early reporting and consultation should be emphasized

    6-Bromoindirubin-3′-Oxime (6BIO) Suppresses the mTOR Pathway, Promotes Autophagy, and Exerts Anti-aging Effects in Rodent Liver

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    Liver aging is associated with age-related histopathological and functional changes that significantly enhance the risk of numerous diseases or disorders developing in elderly populations. 6-Bromoindirubin-3′-oxime (6BIO), a potent inhibitor of glycogen synthase kinase-3 (GSK-3), has been implicated in various age-related diseases and processes, such as tumorigenesis, neurodegeneration, and diabetes. Recent studies have also revealed that 6BIO increases autophagy in yeast, mammalian cell lines, and dopaminergic neurons, which is one of the classical mechanisms strongly associated with liver aging. However, the impact or the mechanism of action of 6BIO in liver remains entirely unknown. Here, we find that 6BIO reduces oxidative stress, improves lipid metabolism, enhances autophagy, and significantly retards liver aging via modulating the GSK-3β pathway and mTOR pathway. Our findings suggest that 6BIO could be a potential agent to protect the liver in the field of anti-aging pharmacology

    Seroprevalence of Toxoplasma gondii infection in dairy goats in Shaanxi Province, Northwestern China

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    <p>Abstract</p> <p>Background</p> <p><it>Toxoplasma gondii </it>is an important zoonotic pathogen causing significant human and animal health problems. Infection in dairy goats not only results in significant reproductive losses, but also represents an important source of human infection due to consumption of infected meat and milk. In the present study we report for the first time seroprevalence of <it>T. gondii </it>infection in Guanzhong and Saanen dairy goats in Shaanxi province, Northwestern China.</p> <p>Results</p> <p>Sera from 751 dairy goats from 9 farms in 6 counties were examined for <it>T. gondii </it>antibodies with an indirect haemagglutination (IHA) test. Antibodies to <it>T. gondii </it>were detected in 106 (14.1%) serum samples, with antibody titres ranging from 1:64 to 1:1024. Seropositive goats were found in all 9 farms and seroprevalences in Guanzhong (16.3%, 75/461) and Saanen (10.7%, 31/290) dairy goats were not statistically significantly different. All the factors (sex, age and location) reported in the present study affected prevalence of infection, and seroprevalence increased with age, suggesting postnatal acquisition of <it>T. gondii </it>infection.</p> <p>Conclusions</p> <p>The results of the present survey indicate that infection by <it>T. gondii </it>is widely prevalent in dairy goats in Shaanxi province, Northwestern China, and this has implications for prevention and control of toxoplasmosis in this province.</p

    Efficient current-induced spin torques and field-free magnetization switching in a room-temperature van der Waals magnet

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    The discovery of magnetism in van der Waals (vdW) materials has established unique building blocks for the research of emergent spintronic phenomena. In particular, owing to their intrinsically clean surface without dangling bonds, the vdW magnets hold the potential to construct a superior interface that allows for efficient electrical manipulation of magnetism. Despite several attempts in this direction, it usually requires a cryogenic condition and the assistance of external magnetic fields, which is detrimental to the real application. Here, we fabricate heterostructures based on Fe3GaTe2 flakes that possess room-temperature ferromagnetism with excellent perpendicular magnetic anisotropy. The current-driven non-reciprocal modulation of coercive fields reveals a high spin-torque efficiency in the Fe3GaTe2/Pt heterostructures, which further leads to a full magnetization switching by current. Moreover, we demonstrate the field-free magnetization switching resulting from out-of-plane polarized spin currents by asymmetric geometry design. Our work could expedite the development of efficient vdW spintronic logic, memory and neuromorphic computing devices
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