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PURPOSE: This study aims to comprehensively assess the safety of Asenapine by conducting an comprehensive statistical analysis of adverse event reports in the FAERS database, with a particular focus on potential adverse reactions related to its use in the treatment of psychiatric disorders. METHODS: Event reports from the first quarter of 2009 to the third quarter of 2023 were collected and analyzed. Detailed examinations of gender, age, reporter identity, and other aspects were conducted to reveal the fundamental characteristics of Asenapine-related adverse events. Signal mining techniques were employed to systematically evaluate various adverse reactions associated with Asenapine. RESULTS: The study found that adverse event reports involving Asenapine were more common among female patients, with the age group mainly distributed between 18 and 45 years. Physicians were the primary reporters of adverse events, and psychiatric disorders, neurological disorders, and gastrointestinal disorders were the most common areas affected by adverse reactions. In addition to known adverse reactions, potential risks not mentioned in the drug label were identified, such as anosognosia, attentional drift, and psychogenic compensation disorder. CONCLUSION: Asenapine carries the risk of various adverse reactions alongside its therapeutic effects. In clinical practice, physicians should closely monitor the occurrence of neurological disorders, psychiatric disorders, and gastrointestinal system disorders.
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Sistemas de Notificação de Reações Adversas a Medicamentos , Antipsicóticos , Bases de Dados Factuais , Dibenzocicloeptenos , Transtornos Mentais , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Antipsicóticos/efeitos adversos , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/induzido quimicamente , Adulto , Adolescente , Adulto Jovem , Doenças do Sistema Nervoso/induzido quimicamente , Idoso , Compostos Heterocíclicos de 4 ou mais Anéis/efeitos adversosRESUMO
PURPOSE: To design a pan-cancer gene panel for childhood malignancies and validate it using clinically characterized patient samples. EXPERIMENTAL DESIGN: In addition to 5,275 coding exons, SJPedPanel also covers 297 introns for fusions/structural variations and 7,590 polymorphic sites for copy number alterations. Capture uniformity and limit of detection are determined by targeted sequencing of cell lines using dilution experiment. We validate its coverage by in silico analysis of an established real-time clinical genomics (RTCG) cohort of 253 patients. We further validate its performance by targeted re-sequencing of 113 patient samples from the RTCG cohort. We demonstrate its power in analyzing low tumor burden specimens using morphologic remission and monitoring samples. RESULTS: Among the 485 pathogenic variants reported in RTCG cohort, SJPedPanel covered 86% of variants, including 82% of 90 rearrangements responsible for fusion oncoproteins. In our targeted re-sequencing cohort, 91% of 389 pathogenic variants are detected. The gene panel enabled us to detect ~95% of variants at allele fraction 0.5%, while the detection rate is ~80% at allele fraction 0.2%. The panel detected low frequency driver alterations from morphologic leukemia remission samples and relapse-enriched alterations from monitoring samples, demonstrating its power for cancer monitoring and early detection. CONCLUSIONS: SJPedPanel enables the cost-effective detection of clinically relevant genetic alterations including rearrangements responsible for subtype-defining fusions by targeted sequencing of ~0.15% of human genome for childhood malignancies. It will enhance the analysis of specimens with low tumor burdens for cancer monitoring and early detection.
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Background: We aimed to evaluate the level of knowledge, awareness, and perceptions regarding osteoporosis (OP) and risk factors in China. Methods: The databases of PubMed, Medline, Embase, Web of science, VIP, and CNKI were searched for papers published before December 2022 using Chinese and English keywords and their combinations: "knowledge", "osteoporosis", "risk factor", "bone health", "perception", "awareness". The levels of knowledge, awareness, and perception about OP, as well as risk factors, clinical symptoms, and health information sources were narratively synthesized. Results: Sixteen papers were finally included for analysis. Participants all showed poor levels of knowledge and perception regarding osteoporosis and risk factors. Investigation of clinical symptoms was rarely involved in the included studies due to the asymptomatic features of OP. The findings also suggest a strong association between poor level of knowledge regarding OP and educational attainment, type of participant, and gender. The majority of participants are increasingly turning to the Internet and social media to access information about OP. Conclusion: The findings of this paper provide useful information for intervention providers to prevent and control OP and encourage them to carry out health promotion campaigns to enhance knowledge and awareness of OP.
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BACKGROUND: In the past 40 years, China has experienced tremendous economic development, but the current situation of hematologists has rarely been reported. A landscape survey of human resources is essential for healthcare development and policy formulation in the future. METHODS: The Chinese Society of Hematology initiated a survey of Chinese hematologists in mainland China for evaluating demographic and practice characteristics. Respondents were anonymous, and there were no limitations regarding their age, sex, etc. RESULTS: Totally 2032 hematologists responded, with a median age bracket of 36-45 years. Respondents were well engaged into subspecialties, and 28.1% acquired doctorates of philosophy. Hematopoietic cell transplantation (HCT) centers have been established all over China. Higher-GDP regions reported more advantages, including bigger scale of transplant centers (P < 0.001), younger age structure (P = 0.039), better education qualifications (P = 0.001) and less turnover intentions (P = 0.004), despite of increased risk of medical disputes (P = 0.028). Although females accounted for 65.5% of hematologists, males were older (P < 0.001), and had more senior professional titles (P < 0.001), academic positions (P < 0.001), opportunities for continuing education (P < 0.001), and paper publishing in the recent two years (P = 0.001). For turnover intention, the higher GDP regions led to an independently reduced risk (HR = 0.673, 95%CI [0.482-0.940], P = 0.020), whereas medical disputes resulted in an increased the risk (HR = 2.037, 95%CI [1.513-2.743], P < 0.001). Considering the impact of the COVID-19 pandemic, majority of respondents believed that the decline in patient visits and delay in treatment was within 30%. 67.9% of respondents reported a decrease of the use of bone marrow as grafts but 18.8% reported an increase of cord blood units. 35.0% of the respondents switched their daily work to support the anti-epidemic medical activities. CONCLUSIONS: We concluded the discipline of hematology in China has flourished in recent years with a young workforce, while regional economic and gender disparities warrant further continuous optimization. Joint efforts against the impact of COVID-19 are needed in the post-pandemic era.
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COVID-19 , Hematologia , Masculino , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Pandemias , Inquéritos e Questionários , Atenção à Saúde , Serviços de SaúdeRESUMO
Nanozymes, a class of synthetic nanomaterials possessing enzymatic catalytic properties, exhibit distinct advantages such as exceptional stability and cost-effectiveness. Among them, metal-organic framework (MOF)-based nanozymes have garnered significant attention due to their large specific surface area, tunable pore size and uniform structure. MOFs are porous crystalline materials bridged by inorganic metal ions/clusters and organic ligands, which hold immense potential in the fields of catalysis, sensors and drug carriers. The combination of MOFs with diverse nanomaterials gives rise to various types of MOF-based nanozyme, encompassing original MOFs, MOF-based nanozymes with chemical modifications, MOF-based composites and MOF derivatives. It is worth mentioning that the metal ions and organic ligands in MOFs are perfectly suited for designing oxidoreductase-like nanozymes. In this review, we intend to provide an overview of recent trends and progress in MOF-based nanozymes with oxidoreductase-like activity. Furthermore, the current obstacles and prospective outlook of MOF-based nanozymes are proposed and briefly discussed. This comprehensive analysis aims to facilitate progress in the development of novel MOF-based nanozymes with oxidoreductase-like activity while serving as a valuable reference for scientists engaged in related disciplines.
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Estruturas Metalorgânicas , Nanoestruturas , Estruturas Metalorgânicas/química , Oxirredutases , Metais , Ligantes , ÍonsRESUMO
The binding process between three species of chromium and serum albumin (SA) was investigated, as well as the interaction between K2Cr2O7 and bovine serum albumin (BSA) under coexistence of different chromium forms. CrCl3, K2Cr2O7 and Crpic bound to SA spontaneously through Van der Waals force, and their binding constants were 103-104 M-1 at 298 K, respectively. K2Cr2O7 and Crpic both had strong binding affinity for BSA, and significantly affected the secondary structure of BSA and the microenvironment surrounding amino acid residues. Chromium exhibited a greater fluorescence quenching constant towards HSA than toward BSA, and K2Cr2O7 induced greater conformational changes in human serum albumin (HSA) than in BSA. A weak binding of CrCl3 to BSA had no significant effect on the binding affinity of K2Cr2O7 to BSA. K2Cr2O7 and BSA have a greater binding affinity when coexisting with Crpic, and K2Cr2O7 induces a greater conformational change in BSA.
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Cromo , Albumina Sérica , Humanos , Albumina Sérica/química , Espectrometria de Fluorescência , Termodinâmica , Soroalbumina Bovina/química , Albumina Sérica Humana/química , Ligação Proteica , Sítios de Ligação , Simulação de Acoplamento MolecularRESUMO
Background: Large scale genomics projects have identified driver alterations for most childhood cancers that provide reliable biomarkers for clinical diagnosis and disease monitoring using targeted sequencing. However, there is lack of a comprehensive panel that matches the list of known driver genes. Here we fill this gap by developing SJPedPanel for childhood cancers. Results: SJPedPanel covers 5,275 coding exons of 357 driver genes, 297 introns frequently involved in rearrangements that generate fusion oncoproteins, commonly amplified/deleted regions (e.g., MYCN for neuroblastoma, CDKN2A and PAX5 for B-/T-ALL, and SMARCB1 for AT/RT), and 7,590 polymorphism sites for interrogating tumors with aneuploidy, such as hyperdiploid and hypodiploid B-ALL or 17q gain neuroblastoma. We used driver alterations reported from an established real-time clinical genomics cohort (n=253) to validate this gene panel. Among the 485 pathogenic variants reported, our panel covered 417 variants (86%). For 90 rearrangements responsible for oncogenic fusions, our panel covered 74 events (82%). We re-sequenced 113 previously characterized clinical specimens at an average depth of 2,500X using SJPedPanel and recovered 354 (91%) of the 389 reported pathogenic variants. We then investigated the power of this panel in detecting mutations from specimens with low tumor purity (as low as 0.1%) using cell line-based dilution experiments and discovered that this gene panel enabled us to detect â¼80% variants with allele fraction of 0.2%, while the detection rate decreases to â¼50% when the allele fraction is 0.1%. We finally demonstrate its utility in disease monitoring on clinical specimens collected from AML patients in morphologic remission. Conclusions: SJPedPanel enables the detection of clinically relevant genetic alterations including rearrangements responsible for subtype-defining fusions for childhood cancers by targeted sequencing of â¼0.15% of human genome. It will enhance the analysis of specimens with low tumor burdens for cancer monitoring and early detection.
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Coastal blue carbon ecosystems offer promising benefits for both climate change mitigation and adaptation. While there have been widespread efforts to transplant mangroves from the tropics to the subtropics and to introduce exotic saltmarsh plants like Spartina alterniflora in China, few studies have thoroughly quantified the chronological records of carbon sequestration with different organic carbon (OC) sources. To understand how variations in OC sources can affect the carbon sequestration potential of coastal wetland environment over time, we conducted a study on typical islands with two scenarios: S. alterniflora invasion and mangrove transplantation. Our study determined chronological records of carbon sequestration and storage from five sediment profiles and traced changes in the OC sources using carbon stable isotope (δ13C) and C:N ratios in response to these scenarios. The S. alterniflora invasion resulted in an 84 ± 19 % increase in the OC burial rate compared to unvegetated mudflats, while mangrove transplantation resulted in a 167 ± 74 % increase in the OC burial rate compared to unvegetated mudflats. S. alterniflora and mangroves showed greater carbon sequestration potential in areas with high supplies of suspended particulate matter, while mangroves needed to grow to a certain scale to display obvious carbon sequestration benefits. In the mangrove saltmarsh ecotone, mature mangrove habitats exhibited resistance to the S. alterniflora invasion, while mangrove transplantation in the environment invaded by S. alterniflora had a significant effect on OC contribution. Besides, plant-derived OC can be exported to the surrounding environment due to the rapid turnover of sediments. The blue carbon chronosequence-based estimation of OC sources and burial rates provides a useful reference for establishing carbon accounting policies.
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Ecossistema , Áreas Alagadas , Sequestro de Carbono , Espécies Introduzidas , Plantas , Poaceae/fisiologia , Carbono/análise , Isótopos de Carbono , ChinaRESUMO
Various marine aquaculture systems have different impacts on the environment, but few assessments were focused on the environmental impact by different systems in the same region. To study the effects of various aquaculture systems on phytoplankton community structure and water properties, 5 surveys were carried out in seaweed (Gracilaria lemaneiformis, GL), shellfish (Mytilus coruscus, MC) and cage fish (Larimichthys crocea, LC) mariculture areas in Dongji island, Zhejiang, China from June to September 2020. Significant differences were observed in some environmental parameters and phytoplankton communities among three aquaculture systems. The dissolved oxygen concentrations and Secchi depth in the surface waters in GL area were relatively higher than in the blank and other areas. As for nutrients concentration, LC and MC areas had higher concentrations than blank area, while GL area was the lowest. Though Chlorophyll-a concentration displayed fluctuations, relatively lower concentrations were found in GL area. Shannon diversity index was found to be relatively constant and higher in GL area. The Non-metric multidimensional scaling results revealed that phytoplankton composition had a distinct pattern among sampling times. The correlations and Redundancy analysis showed that total nitrogen, salinity and transparency were primary environmental factors associated with phytoplankton composition. Our study confirmed that different marine aquaculture systems can cause environmental fluctuations. Among the three systems, seaweed cultivation can bring multiple positive effects by improving surrounding water quality and increasing the phytoplankton composition. G. lemaneiformis culture in summer has great positive impact on seawater environment as it can maintain the ecological balance and reduce the risk of harmful algal blooms (HABs), and therefore, it is strongly recommended more G. lemaneiformis cultivation in this region in summer.
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Fitoplâncton , Alga Marinha , Animais , Qualidade da Água , Frutos do Mar , Água do Mar , ChinaRESUMO
Background: A good perception of disease risk can help patients adopt correct preventive behaviors and good adherence to treatment. We examined knowledge, awareness, and perception towards thyroid cancer (TC) by a systematic analysis of published literature. Methods: Four databases, including PubMed, Medline, Embase, and Web of science were searched using relevant keywords for papers prior to June 30, 2022. The levels of knowledge, awareness, and perception about TC, as well as risk factors, clinical signs, and sources of health were narratively synthesized. Results: Ten papers were finally included in this study for analysis. Despite relative good awareness, both the general population and medical students have relatively poor levels of knowledge and perception of TC and risk factors. The results of most studies showed that less than half of the participants had good knowledge about TC and its risk factors. Most participants are increasingly turning to the Internet and social media to obtain information about TC. This study also indicated that poor levels of knowledge regarding TC were strongly related to educational attainment and type of participants. Conclusion: The findings of this paper provide valuable information for intervention providers to prevent and control of TC and encourage them to carry out health promotion campaigns to enhance knowledge and awareness of TC.
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Background: Thyroid cancer (TC) is becoming an increasing public health problem worldwide. TikTok is a global video-sharing social media app, which can be a source of information on TC. However, the information quality of these videos remains unknown. Methods: A search of TikTok was performed with the term ""and "" ("thyroid cancer" and "thyroid neoplasm" in Chinese). Videos included were independently assessed using six predefined questions for content scores and DISCERN scale for information quality, while the video popularity index (VPI) was also calculated. A correlation analysis was performed among duration, presence of animation, VPI, DISCERN scores, and content scores. Results: A total of 56 videos were finally included, of which 49 were uploaded by physicians, 4 by health organizations, and 3 by hospitals. While 43 were real content videos, 13 were animated. The mean of DISCERN score and content score was 3.44 ± 0.72 and 5.19 ± 0.95, respectively. Good consistency was found between the two reviewers in terms of both DISCERN scores and content scores. The video duration and presence of animation were positively correlated with VPI, while DISCERN scores and content scores were not correlated with VPI. Conclusion: The overall quality of TC-related videos was satisfactory, although the quality varies greatly depending on the type of source. Patients should be cautious when using TikTok as a source of TC-related information.
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Disseminação de Informação , Mídias Sociais , Neoplasias da Glândula Tireoide , Humanos , Gravação em VídeoRESUMO
Limited numbers of available hematopoietic stem cells (HSCs) limit the widespread use of HSC-based therapies. Expansion systems for functional heterogenous HSCs remain to be optimized. Here, we present a convenient strategy for human HSC expansion based on a biomimetic Microniche. After demonstrating the expansion of HSC from different sources, we find that our Microniche-based system expands the therapeutically attractive megakaryocyte-biased HSC. We demonstrate scalable HSC expansion by applying this strategy in a stirred bioreactor. Moreover, we identify that the functional human megakaryocyte-biased HSCs are enriched in the CD34+CD38-CD45RA-CD90+CD49f lowCD62L-CD133+ subpopulation. Specifically, the expansion of megakaryocyte-biased HSCs is supported by a biomimetic niche-like microenvironment, which generates a suitable cytokine milieu and supplies the appropriate physical scaffolding. Thus, beyond clarifying the existence and immuno-phenotype of human megakaryocyte-biased HSC, our study demonstrates a flexible human HSC expansion strategy that could help realize the strong clinical promise of HSC-based therapies.
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Biomimética , Megacariócitos , Humanos , Células-Tronco Hematopoéticas , Antígenos CD34 , Antígenos Comuns de LeucócitoRESUMO
Lipid-lowering drugs are often taken with anticoagulant drugs in hyperlipidemia patients. Fenofibrate (FNBT) and warfarin (WAR) are common clinical lipid-lowering drugs and anticoagulant drugs, respectively. A study of binding affinity, binding force, binding distance, and binding sites was performed to determine the interaction mechanism between drugs and carrier proteins (bovine serum albumin, BSA), as well as their effects on BSA conformation. Both FNBT and WAR can form complexes with BSA by van der Waals force and hydrogen bonds. WAR had a stronger fluorescence quenching effect on BSA, a stronger binding affinity, and greater effects on BSA conformation than FNBT. According to fluorescence spectroscopy and cyclic voltammetry, co-administration of drugs decreased one drug's binding constant to BSA and increased its binding distance. This suggested that each drug's binding to BSA was disturbed by each other, as well as each drug's binding ability to BSA was altered by the other. It was demonstrated that co-administration of drugs had greater effects on the secondary structure of BSA and microenvironment polarity surrounding amino acid residues, using multiple spectroscopy techniques, such as ultraviolet spectroscopy, Fourier transform infrared spectroscopy, and synchronous fluorescence spectroscopy.
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Fenofibrato , Soroalbumina Bovina , Humanos , Soroalbumina Bovina/química , Ligação Proteica , Varfarina , Termodinâmica , Espectrofotometria Ultravioleta , Sítios de Ligação , Espectroscopia de Infravermelho com Transformada de Fourier , Espectrometria de Fluorescência , Estrutura Secundária de Proteína , Anticoagulantes , Lipídeos , Simulação de Acoplamento MolecularRESUMO
Aim: This study aimed to develop an ELISA array-based immunoassay for the simultaneous detection of osteoporosis-relevant biomarkers. Methods: ELISA array was constructed and its performance was evaluated using commercial antigens. The validity was further confirmed using traditional ELISA. Results: The constructed ELISA array showed good repeatability. The linear ranges and limits of detection for the four markers mentioned above were 0.01-8 ng/ml (1 pg/ml), 5.0-1000 ng/ml (1 ng/ml), 0.5-400 ng/ml (0.1 ng/ml) and 1-100 ng/ml (1 ng/ml), respectively. The measured concentrations of serum samples by ELISA array showed high correlation with those from traditional ELISA. Conclusion: ELISA array-based immunoassay provided a feasible and productive method to multiplex measure markers for osteoporosis.
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Colágeno Tipo I , Osteoporose , Humanos , Osteoporose/diagnóstico , Biomarcadores/análise , Imunoensaio/métodos , Ensaio de Imunoadsorção EnzimáticaRESUMO
BACKGROUND: Nasopharyngeal swabs are taken to determine the causative agent of community acquired pneumonia (CAP), while the reliability of upper respiratory tract sampling as a proxy for lower respiratory tract infections is still unclear. METHODS: Nasopharyngeal (NP) swabs, bronchoalveolar lavage (BAL) fluid samples and clinical data were collected from 153 hospitalized children between 3 months and 14 years of age with severe CAP, enrolled from March to June 2019. Written informed consent for the storage and use of the samples for further studies was obtained from the parents or caregivers. Putative pathogens were detected using a sensitive, high-throughput GeXP-based multiplex PCR and qPCR. RESULTS: The same bacterial species in paired samples were found in 29 (23.4%) and the same viral species in 52 (27.5%) of the patients. moderate concordance was found for Mycoplasma pneumoniae (ĸ=0.64), followed by Haemophilus influenzae (ĸ=0.42). The strongest discordance was observed for human adenovirus and also for Pseudomonas aeruginosa, the latter was exclusively detected in BAL samples. In the adenovirus cases strong concordance was associated with high viral loads in the NP swabs. CONCLUSION: The variation in concordance in pathogen detection in the upper and lower respiratory tract of children with severe pneumonia is generally high but varies depending on the species. Novel and impactful insights are the concordance between NP and BAL detection for M. pneumoniae and H. influenzae and the strong correlation between high adenoviral loads in NP swabs and detection in BAL fluid.
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Infecções Comunitárias Adquiridas , Pneumonia , Infecções Respiratórias , Criança , Humanos , Lactente , Reprodutibilidade dos Testes , Bactérias/genética , Pneumonia/diagnóstico , Líquido da Lavagem Broncoalveolar/microbiologia , Infecções Respiratórias/diagnóstico , Mycoplasma pneumoniae , Haemophilus influenzae , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/microbiologia , TraqueiaRESUMO
Nanozymes have been widely used to construct colorimetric sensors due to their advantages of cost-effectiveness, high stability, good biocompatibility, and ease of modification. The emergence of nanozymes greatly enhanced the detection sensitivity and stability of the colorimetric sensing platform. Recent significant research has focused on designing various sensors based on nanozymes with peroxidase-like activity for colorimetric analysis. However, with the deepening of research, nanozymes with peroxidase-like activity has also exposed some problems, such as weak affinity and low catalytic activity. In view of the above issues, existing investigations have shown that the catalytic properties of nanozymes can be improved by adding surface modification and changing the structure of nanomaterials. In this review, we summarize the recent trends and advances of colorimetric sensors based on several typical nanozymes with peroxidase-like activities, including noble metals, metal oxides, metal sulfides/metal selenides, and carbon and metal-organic frameworks (MOF). Finally, the current challenges and prospects of colorimetric sensors based on nanozymes with peroxidase-like activity are summarized and discussed to provide a reference for researchers in related fields.
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Colorimetria , Nanoestruturas , Nanoestruturas/química , Catálise , Metais , Peroxidases/químicaRESUMO
Various forms of vanadium coexist in vivo, and the behavior mechanism is different. An investigation of the separate and simultaneous binding of three vanadium forms with bovine serum albumin (BSA) was performed. VO(acac)2/NaVO3/VOSO4 bound to site I of BSA, and their binding constants were 4.26 × 105, 9.18 × 103, and 4.31 × 102 L mol-1 at 298 K, respectively. VO(acac)2 had the strongest binding ability to BSA and had the most influence on the secondary structure of BSA and the microenvironment of around amino acid residues. The effect of NaVO3 and VOSO4 coexistence on the binding of VO(acac)2 to BSA was therefore further investigated. Both NaVO3 and VOSO4 had an effect on the binding of VO(acac)2 and BSA, with NaVO3 having the most noticeable effect. NaVO3 interfered with the binding process of VO(acac)2 and BSA, increased the binding constant, and changed the binding forces between them. Competition and allosteric effect may be responsible for the change of binding process between VO(acac)2 and BSA in the presence of NaVO3/VOSO4.
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Soroalbumina Bovina , Vanádio , Sítios de Ligação , Ligação Proteica , Espectrometria de Fluorescência , Vanádio/farmacologiaRESUMO
Enzymatic isomerization of lactose into lactulose via cellobiose 2-epimerase (CE) could provide an eco-friendly route for the industrial production of lactulose, a valuable food prebiotic. However, poor substrate affinity for lactose and preference for epimerization over isomerization hinder this application. Previous studies on CE improvement have focused on random mutagenesis or active site rational design; little is known about the relationship between substrate binding and enzyme efficacy, which was hence the subject of this study. First, residues 372W and 308W were identified as key for disaccharide recognition in CEs based on crystal structure alignment of the N-acetyl-glucosamine 2-epimerase superfamily and site-directed mutation. This binding domain was then reshaped through site saturation mutagenesis, resulting in seven mutants with enhanced isomerization activity. The optimal mutant CsCE/Q371E had significantly enhanced substrate affinity (Km, 269.65 mM vs Km, 417.5 mM), reduced epimerization activity, and 3.3-fold increased isomerization activity over the original CsCE. Molecular dynamics simulation further revealed that substituting Gln-371 with Glu strengthened the hydrogen-bonding network and altered the active site-substrate interactions, increasing the substrate stability and shifting the catalytic direction. This study uncovered new information about the substrate binding region and its mechanisms and impact on CE catalytic performance, paving the way for potential commercial applications.
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Celobiose , Lactulose , Lactulose/química , Celobiose/metabolismo , Lactose/química , Isomerismo , Racemases e Epimerases/genética , Racemases e Epimerases/metabolismo , Especificidade por SubstratoRESUMO
Benzophenone (BP)-type UV filters can cause structural changes of carrier protein in plasma. The binding process of five BP-type UV filters with bovine serum albumin (BSA) was investigated by multiple characterization methods, along with their structure-affinity relationship involving the structure of the five BP-type UV filters and their binding affinity for BSA. The BP-type UV filters investigated bound to BSA spontaneously, and altered conformation of BSA. The binding constants and number of binding sites between BP-type UV filters and BSA were 103-106 M-1 and 0.82-1.26, respectively. These BP-type UV filters and BSA interacted with the same binding forces and went through the similar binding process, suggesting that the benzophenone skeleton structure was primarily responsible for the BP-type UV filters and BSA binding, and changes in the structure of the BSA. The BP-type UV filters with hydroxyl substituent (BP-1 and BP-9) and non-polar molecules (BP-6) had a high affinity for binding BSA and had a greater impact on BSA conformation.
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Benzofenonas , Soroalbumina Bovina , Soroalbumina Bovina/química , Espectrometria de Fluorescência , Sítios de Ligação , Ligação Proteica , TermodinâmicaRESUMO
Removing the blocked molecular groups and fully exposing the intrinsic active sites of metal-organic frameworks (MOFs) could give full play to their advantages of multi-active sites and multi-channel mass transfer, which will benefit the electrocatalytic oxygen reduction reaction (ORR) in fuel cells. Here, the partial diligandation-activated ZIF-67 (named as ZIF-67-400) with excellent ORR performance was obtained by simple low-temperature pyrolysis. The ORR electrocatalytic activity exhibits a half-wave potential of 0.82 V and the stability of maintaining 96% activity after 10 h of operation, which is comparable to commercial Pt/C. Further research studies reveal that the morphology, special dodecahedron configuration, and crystal structure of ZIF-67-400 are maintained well during the pyrolysis, but some hydrocarbon groups in the ligands are eliminated, resulting in the active sites being exposed and coordinated with the intrinsic porosity, improving the catalytic performance. This work may provide an alternative path for activating the electrocatalytic performance of metal-organic frameworks by low-temperature annealing.