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Glucagon-like peptide-1 (GLP-1) and its analogs are widely used for diabetes treatment. The paraventricular nucleus (PVN) is crucial for regulating cardiovascular activity. This study aims to determine the roles of GLP-1 and its receptors (GLP-1R) in the PVN in regulating sympathetic outflow and blood pressure. Experiments were carried out in male normotensive rats and spontaneously hypertensive rats (SHR). Renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) were recorded. GLP-1 and GLP-1R expressions were present in the PVN. PVN microinjection of GLP-1R agonist recombinant human GLP-1 (rhGLP-1) or EX-4 increased RSNA and MAP, which were prevented by GLP-1R antagonist exendin 9-39 (EX9-39) or GLP-1R antagonist 1, superoxide scavenger tempol, antioxidant N-acetylcysteine, NADPH oxidase (NOX) inhibitor apocynin, adenylyl cyclase (AC) inhibitor SQ22536 or protein kinase A (PKA) inhibitor H89. PVN microinjection of rhGLP-1 increased superoxide production, NADPH oxidase activity, cAMP level, AC, and PKA activity, which were prevented by SQ22536 or H89. GLP-1 and GLP-1R were upregulated in the PVN of SHR. PVN microinjection of GLP-1 agonist increased RSNA and MAP in both WKY and SHR, but GLP-1 antagonists caused greater effects in reducing RSNA and MAP in SHR than in WKY. The increased superoxide production and NADPH oxidase activity in the PVN of SHR were augmented by GLP-1R agonists but attenuated by GLP-1R antagonists. These results indicate that activation of GLP-1R in the PVN increased sympathetic outflow and blood pressure via cAMP-PKA-mediated NADPH oxidase activation and subsequent superoxide production. GLP-1 and GLP-1R upregulation in the PVN partially contributes to sympathetic overactivity and hypertension.
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Peptídeo 1 Semelhante ao Glucagon , Receptor do Peptídeo Semelhante ao Glucagon 1 , Hipertensão , Núcleo Hipotalâmico Paraventricular , Ratos Endogâmicos SHR , Sistema Nervoso Simpático , Animais , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Núcleo Hipotalâmico Paraventricular/metabolismo , Masculino , Hipertensão/fisiopatologia , Hipertensão/metabolismo , Ratos , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/fisiologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/antagonistas & inibidores , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Ratos Endogâmicos WKY , Ratos Sprague-DawleyRESUMO
The discovery and utilization of main-group element catalysts that behave similarly to transition metal (TM) complexes have become increasingly active areas of investigation in recent years. Here, we report a series of Lewis acidic bismuth(III) complexes that allow for the catalytic allylic C(sp3)-H functionalization of olefins via an organometallic complexation-assisted deprotonation mechanism to generate products containing new C-C bonds. This heretofore unexplored mode of main-group reactivity was applied to the regioselective functionalization of 1,4-dienes and allylbenzene substrates. Experimental and computational mechanistic studies support the key steps of the proposed catalytic cycle, including the intermediacy of elusive Bi-olefin complexes and allylbismuth species.
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BACKGROUND: Metabolic syndrome (MetS) elevates cancer risk. However, a single MetS assessment does not fully reveal the long-term association with cancer. Inflammation, alongside MetS, could synergistically expedite both the onset and advancement of cancer. This study aims to investigate MetS score trajectories and cancer risk in a large, prospective cohort study. METHODS: The authors prospectively examined the relationship between MetS score trajectory patterns and new-onset cancer in 44,115 participants. Latent mixture modeling was used to identify the MetS score trajectories. Cox proportional hazards regression models were used to evaluate the association between MetS score trajectory patterns and the risk of overall and site-specific cancers. RESULTS: Four MetS score trajectory patterns were identified: low-stable (n = 4657), moderate-low (n = 18,018), moderate-high (n = 18,288), and elevated-increasing (n = 3152). Compared to participants with a low-stable trajectory pattern, the elevated-increasing trajectory pattern was associated with an elevated risk of overall (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.04-1.55), breast (HR, 2.11; 95% CI, 1.04-4.34), endometrial (HR, 3.33; 95% CI, 1.16-6.77), kidney (HR, 4.52; 95% CI, 1.17-10.48), colorectal (HR, 2.54; 95% CI, 1.27-5.09), and liver (HR, 1.61; 95% CI, 1.09-4.57) cancers. Among participants with chronic inflammation (C-reactive protein levels ≥3 mg/L), the elevated-increasing trajectory pattern was significantly associated with subsequent breast, endometrial, colorectal, and liver cancers. CONCLUSIONS: Trajectories of MetS scores are associated with the occurrence of cancers, especially breast, endometrial, kidney, colorectal, and liver cancers, emphasizing the importance of long-term monitoring and evaluation of MetS. PLAIN LANGUAGE SUMMARY: The association between long-term elevated metabolic syndrome (MetS) scores and a heightened risk of various cancers is a pivotal finding of our study. Our research further indicates that individuals with MetS, particularly when coupled with chronic inflammation, are at an increased risk of cancer. We propose that sustained monitoring and management of MetS could be beneficial in reducing cancer risk.
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Síndrome Metabólica , Neoplasias , Humanos , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Feminino , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Estudos Prospectivos , Adulto , Fatores de Risco , Modelos de Riscos Proporcionais , Idoso , Inflamação/complicaçõesRESUMO
By utilizing bicontinuous and nanoporous ordered nanonetworks, such as double gyroid (DG) and double diamond (DD), metamaterials with exceptional optical and mechanical properties can be fabricated through the templating synthesis of functional materials. However, the volume fraction range of DG in block copolymers is significantly narrow, making it unable to vary its porosity and surface-to-volume ratio. Here, the theoretically limited structural volume of the DG phase in coil-coil copolymers is overcome by enlarging the conformational asymmetry through the association of mesogens, providing fast access to achieving flexible structured materials of ultra-high porosities. The new materials design, dual-extractable nanocomposite, is created by incorporating a photodegradable block with a solvent-extractable mesogen (m) into an accepting block, resulting in a new hollow gyroid (HG) with the largely increased surface-to-volume ratio and porosity of 77 vol%. The lightweight HG exhibits a low refractive index of 1.11 and a very high specific reduced modulus, almost two times that of the typical negative gyroid (porosity≈53%) and three times that of the positive gyroid (porosity≈24%). This novel concept can significantly extend the DG phase window of block copolymers and the corresponding surface-to-volume ratio, being applicable for nanotemplate-synthesized nanomaterials with a great gain of mechanical, catalytic, and optoelectronic properties.
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Quantum mechanics/molecular mechanics (QM/MM) simulations offer an efficient way to model reactions occurring in complex environments. This study introduces a specialized set of charge and Lennard-Jones parameters tailored for electrostatically embedded QM/MM calculations, aiming to accurately model both adsorption processes and catalytic reactions in zirconium-based metal-organic frameworks (Zr-MOFs). To validate our approach, we compare adsorption energies derived from QM/MM simulations against experimental results and Monte Carlo simulation outcomes. The developed parameters showcase the ability of QM/MM simulations to represent long-range electrostatic and van der Waals interactions faithfully. This capability is evidenced by the prediction of adsorption energies with a low root mean square error of 1.1 kcal mol-1 across a wide range of adsorbates. The practical applicability of our QM/MM model is further illustrated through the study of glucose isomerization and epimerization reactions catalyzed by two structurally distinct Zr-MOF catalysts, UiO-66 and MOF-808. Our QM/MM calculations closely align with experimental activation energies. Importantly, the parameter set introduced here is compatible with the widely used universal force field (UFF). Moreover, we thoroughly explore how the size of the cluster model and the choice of density functional theory (DFT) methodologies influence the simulation outcomes. This work provides an accurate and computationally efficient framework for modeling complex catalytic reactions within Zr-MOFs, contributing valuable insights into their mechanistic behaviors and facilitating further advancements in this dynamic area of research.
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PURPOSE: Major Depressive Disorder (MDD) and Insomnia Disorder (ID) are prevalent psychiatric conditions often occurring concurrently, leading to substantial impairment in daily functioning. Understanding the neurobiological underpinnings of these disorders and their comorbidity is crucial for developing effective interventions. This study aims to analyze changes in functional connectivity within attention networks and default mode networks in patients with depression and insomnia. METHODS: The functional connectivity alterations in individuals with MDD, ID, comorbid MDD and insomnia (iMDD), and healthy controls (HC) were assessed from a cohort of 174 participants. They underwent rs-fMRI scans, demographic assessments, and scale evaluations for depression and sleep quality. Functional connectivity analysis was conducted using region-of-interest (ROI) and whole-brain methods. RESULTS: The MDD and iMDD groups exhibited higher Hamilton Depression Scale (HAMD) scores compared to HC and ID groups (P < 0.001). Both ID and MDD groups displayed enhanced connectivity between the left and right orbital frontal cortex compared to HC (P < 0.05), while the iMDD group showed reduced connectivity compared to HC and ID groups (P < 0.05). In the left insula, reduced connectivity with the right medial superior frontal gyrus was observed across patient groups compared to HC (P < 0.05), with the iMDD group showing increased connectivity compared to MDD (P < 0.05). Moreover, alterations in functional connectivity between the left thalamus and left temporal pole were found in iMDD compared to HC and MDD (P < 0.05). Correlation analyses revealed associations between abnormal connectivity and symptom severity in MDD and ID groups. CONCLUSIONS: Our findings demonstrate distinct patterns of altered functional connectivity in individuals with MDD, ID, and iMDD compared to healthy controls. These findings contribute to a better understanding of the pathophysiology of depression and insomnia, which could be used as a reference for the diagnosis and treatments of these patients.
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Rede de Modo Padrão , Transtorno Depressivo Maior , Imageamento por Ressonância Magnética , Distúrbios do Início e da Manutenção do Sono , Humanos , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Distúrbios do Início e da Manutenção do Sono/diagnóstico por imagem , Masculino , Feminino , Adulto , Transtorno Depressivo Maior/fisiopatologia , Pessoa de Meia-Idade , Rede de Modo Padrão/fisiopatologia , Rede Nervosa/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Atenção/fisiologia , Comorbidade , Encéfalo/fisiopatologia , Encéfalo/diagnóstico por imagem , ConectomaRESUMO
BACKGROUND: Remote rehabilitation after total knee arthroplasty has gradually gained popularity in recent years. This study aimed to determine whether smartphone application-based remote rehabilitation could outperform home-based rehabilitation and outpatient guidance in terms of 12-week outcomes following primary unilateral total knee arthroplasty. METHODS: Patients who underwent primary unilateral total knee arthroplasty were recruited and randomly divided into a telerehabilitation group and a control group. A total of 100 patients were examined, with 50 each assigned to the telerehabilitation and control groups. In the telerehabilitation group, a telerehabilitation application was installed on the smartphones of the participants to allow postdischarge guidance. The primary outcomes were knee range of motion (ROM) at 12 weeks postoperatively. Secondary outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society Score, The Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), Five Times Sit-to-Stand Test (5xSST), Single-Leg Stance Test (SLST), satisfaction, rehabilitation costs, complication rate, and 90-day readmission rate. All outcomes were collected at 2, 6, and 12 weeks after surgery. RESULTS: At 12 weeks postoperatively, the telerehabilitation patients significantly outperformed the controls in terms of knee ROM (124 ± 8.7 versus 119 ± 5.5 P = .01), SF-36 (physiological function) (61.5 ± 20.3 versus 45.5 ± 18.1 P = .000), SF-36 (role-physical) (49.3 ± 41.5 versus 27.7 ± 28.9 P = .012), SLST (13.0 ± 9.1 versus 9.1 ± 5.9 P = .026), and 5xSST (17.7 ± 4.3 versus 19.4 ± 3.5 P = .043). No significant differences were found between groups in the Western Ontario and McMaster Universities Osteoarthritis Index score, Knee Society Score, rehabilitation costs, 90-day readmission rate, or incidence of adverse events. CONCLUSION: Our study showed that smartphone app-based remote rehabilitation worked better than home-based rehabilitation with outpatient guidance in terms of short-term results in ROM, SLST, and 5xSST.
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Artroplastia do Joelho , Aplicativos Móveis , Osteoartrite do Joelho , Osteoartrite , Telerreabilitação , Humanos , Artroplastia do Joelho/reabilitação , Telerreabilitação/métodos , Smartphone , Assistência ao Convalescente , Resultado do Tratamento , Alta do Paciente , Osteoartrite/cirurgia , Osteoartrite do Joelho/cirurgiaRESUMO
We report a highly enantioselective intermolecular C-H bond silylation catalyzed by a phosphoramidite-ligated iridium catalyst. Under reagent-controlled protocols, propargylsilanes resulting from C(sp3)-H functionalization, as well the regioisomeric and synthetically versatile allenylsilanes, could be obtained with excellent levels of enantioselectivity and good to excellent control of propargyl/allenyl selectivity. In the case of unsymmetrical dialkyl acetylenes, good to excellent selectivity for functionalization at the less-hindered site was also observed. A variety of electrophilic silyl sources (R3SiOTf and R3SiNTf2), either commercial or in situ-generated, were used as the silylation reagents, and a broad range of simple and functionalized alkynes, including aryl alkyl acetylenes, dialkyl acetylenes, 1,3-enynes, and drug derivatives were successfully employed as substrates. Detailed mechanistic experiments and DFT calculations suggest that an η3-propargyl/allenyl Ir intermediate is generated upon π-complexation-assisted deprotonation and undergoes outer-sphere attack by the electrophilic silylating reagent to give propargylic silanes, with the latter step identified as the enantiodetermining step.
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Cyclopentadienyliron dicarbonyl-based complexes present opportunities for underexplored disconnections in synthesis. Access to challenging dihydropyrrolone products is achieved by propargylic C-H functionalization of alkynes for the formation of cyclic organoiron species. Excellent regioselectivity for unsymmetrical alkynes is observed in many cases. Notably, regioselectivity under these stoichiometric conditions diverges from those observed previously under catalysis, occurring at the more-substituted terminus of the alkyne, allowing for methine functionalization and the formation of quaternary centers. Divergent demetallation of the intermediate organoiron complexes gives access to chemically diverse products which are amenable to further functionalization.
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Carbazole, as one of the most important organic frameworks, has been used in optoelectronic materials and biochemistry. However, the synthesis of C4-substituted carbazole has always been an unsolved problem. This report describes the one-step synthesis of C4-aminated carbazoles and their derivatives through the series reaction of C-H amination and arylation. The substrate scope is wide. C4-Amino carbazoles substituted by C2, C6, C7, and C8 methyl groups, especially carbazole derivatives of fused rings, pyridine, and dibenzofuran, can be synthesized.
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This report describes the use of a simple Pd/NBE catalytic system to achieve ortho C-H oxylation and phosphonylation and other functionalizations of aryl iodide through templated conversion reactions. Dimethylamine is introduced in the ortho-site of aryl iodide through C-H amination, and aryl dimethylamine is quickly converted to methyl quaternary ammonium salt precipitation. Methyl quaternary ammonium salt avoids Hofmann elimination in subsequent functionalization. This method solves various ortho functionalization reactions of aryl iodide that have not been achieved for a long time in the field of Pd/NBE chemistry indirectly.
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BACKGROUND: Previous studies have shown that insomnia affects human prefrontal function and that there are specific patterns of brain activation to counteract sleep and improve cognition. However, the effects of insomnia on the prefrontal cortex of MDD (major depressive disorder) patients and the patterns of activation to counteract sleep in MDD patients remain unclear. The aim of this study is to examine this using fNIRS (functional near-infrared spectroscopy). METHODS: Eighty depressed patients and 44 healthy controls were recruited for this study. fNIRS was used to assess changes in the concentration of oxygenated hemoglobin ([oxy-Hb]) in the prefrontal cortex of all participants during the VFT (verbal fluency test) and to record the number of words created to assess cognitive ability. The Pittsburgh Sleep Quality Index was used to assess sleep quality, and the Hamilton Rating Scale for Depression (24-item) and Hamilton Rating Scale for Anxiety (14-item) were used to assess the severity of depression and anxiety. RESULTS: When comparing patients, the healthy control group had significantly higher [oxy-Hb] values in the bilateral prefrontal cortex during VFT than the MDD group. In the MDD group, the [oxy-Hb] values in all brain regions except the right DLPFC were significantly higher in the group with insomnia than in the group without insomnia, but their VFT performance was significantly lower than in the group without insomnia and the healthy group. PSQI scores were positively correlated with [oxy-Hb] values in some left-brain regions, whereas HAMD and HAMA scores were not correlated with [oxy-Hb] values. CONCLUSION: The PFC was significantly less active during VFT in those with MDD than in healthy controls. All brain regions, except the right DLPFC, were significantly more active in MDD patients with insomnia than in those without insomnia, suggesting that sleep quality needs to be an important indicator in fNIRS screening. In addition, there was a positive correlation between the severity of insomnia in the left VLPFC and the level of activation, suggesting a role for the left brain region in the neurophysiology of overcoming sleepiness in MDD patients. these findings may provide new ideas for the treatment of MDD patients in the future. TRIAL REGISTRATION: Our experiment was registered in the China Clinical Trial Registry (registration number ChiCTR2200065622) on November 10.( The first patient was recruited in 10/11/2022.).
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Transtorno Depressivo Maior , Distúrbios do Início e da Manutenção do Sono , Humanos , Ansiedade , Depressão , Transtorno Depressivo Maior/diagnóstico , Córtex Pré-Frontal/diagnóstico por imagem , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Distúrbios do Início e da Manutenção do Sono/complicaçõesRESUMO
Schisandrin B (Scheme B) is the most abundant and active lignan monomer isolated from Schisandra chinensis. At present, most reports focus on its cardioprotective and hepatoprotective effects, however, the related reports on gastrointestinal protective effects are still limited. The study aims to evaluate the protective effect of Scheme B on cisplatin-induced rat intestinal crypt epithelial (IEC-6) cell injury and the possible molecular mechanisms. The results showed that Scheme B at 2.5, 5 and 10 µM could inhibit dose-dependently the reduction of cell activity induced by cisplatin exposure at 1 µM, decrease the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), while increasing glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) to alleviate oxidative stress injury in IEC-6 cell lines. Meanwhile, Scheme B could relieve cisplatin-induced apoptosis by regulating PI3K/AKT and the downstream caspase signaling pathway. The results from flow cytometry analysis and mitochondrial membrane potential (MMP) staining also demonstrated the anti-apoptosis effect of Scheme B. Furthermore, Scheme B was found to reduce the inflammation associated with cell damage by evaluating the protein expressions of the nuclear factor-kappa B (NF-κB) signaling pathway. Importantly, Wnt/ß-catenin, as a functional signaling pathway that drives intestinal self-recovery, was also in part regulated by Scheme B. In conclusion, Scheme B might alleviate cisplatin-induced IEC-6 cell damage by inhibiting oxidative stress, apoptosis, inflammation, and repairing intestinal barrier function. The present research provides a strong evidence that Scheme B may be a useful modulator in cisplatin-induced intestinal toxicity.
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Lignanas , Schisandra , Ratos , Animais , Cisplatino/efeitos adversos , Fosfatidilinositol 3-Quinases/metabolismo , Lignanas/farmacologia , Estresse Oxidativo , NF-kappa B/metabolismo , Glutationa/metabolismo , InflamaçãoRESUMO
We present a framework for studying the spillover effect of negative foreign COVID-19 news on attitudes towards immigration. Our framework proposes that exposure to negative COVID-19 news from foreign countries can activate negative associations with foreigners, reduce positive attitudes towards them, and increase perceived threat, ultimately leading to decreased support for immigration. We conducted three studies to test this framework. Study 1 found that exposure to negative COVID-19 news about a foreign country increased negative valence associations with that country. Study 2 showed that exposure to more negative COVID-19 news about foreign countries was associated with lower acceptance of immigration policies in real life. Study 3 replicated the spillover effect of negative news exposure using a scenario manipulation. The effects of negative news exposure on immigration policy acceptance in both Studies 2 and 3 were mediated by changes in foreigner attitudes and intergroup threat. Our results demonstrate the important spillover effect of negative foreign COVID-19 news exposure on immigration attitudes and highlight the association perspective as a foundation for understanding attitude changes during the COVID-19 pandemic.
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This study aimed to evaluate the efficacy and safety of various oral Chinese patent medicines in the adjuvant treatment of rotavirus gastroenteritis(RVGE) in children based on network Meta-analysis. Randomized controlled trial(RCT) of oral Chinese patent medicine in the adjuvant treatment of RVGE in children was retrieved from the databases such as CNKI, Wanfang, VIP, SinoMed, PubMed, Cochrane Library, EMbase, and Web of Science from database inception to October 22, 2022. The quality of the included RCT was evaluated according to the Cochrane risk-of-bias tool, and the data were analyzed by RevMan 5.4 and Stata 16 software. Sixty-three RCTs were included, with 11 oral Chinese patent medicines involved, including Xingpi Yanger Granules, Weichang'an Pills, Qiuxieling Mixture, Erxieting Granules, and Changyanning Granules/Syrup. The results of the network Meta-analysis showed that in terms of clinical total effective rate, the top 3 optimal interventions were Changyanning Granules/Syrup, Xiaoer Guangpo Zhixie Oral Liquid, and Xiaoer Shuangjie Zhixie Granules combined with conventional western medicine. In terms of the anti-diarrheal time, the top 3 optimal interventions were Shenling Baizhu Granules, Qiuxieling Mixture, and Shuangling Zhixie Oral Liquid combined with conventional western medicine. In terms of the antiemetic time, the top 3 optimal interventions were Changyanning Granules/Syrup, Xingpi Yanger Granules, and Xiaoer Shuangjie Zhixie Granules combined with conventional western medicine. In terms of the antipyretic time, the top 3 optimal interventions were Shenling Baizhu Granules, Xiaoer Shuangjie Zhixie Granules, and Qiuxieling Mixture combined with conventional western medicine. In terms of the negative conversion rate of rotavirus, the top 3 optimal interventions were Xingpi Yanger Granules, Erxieting Granules, and Cangling Zhixie Oral Liquid combined with conventional western medicine. In terms of reducing creatine kinase isoenzyme MB(CK-MB) level, the top 3 optimal interventions were Weichang'an Pills, Xingpi Yanger Granules, and Xiaoer Shuangjie Zhixie Granules combined with conventional western medicine. In terms of adverse reactions, no se-rious adverse reactions were reported in all studies. Oral Chinese patent medicines in the adjuvant treatment of children with RVGE have their own advantages, Specifically, Changyanning Granules/Syrup + conventional western medicine focuses on improving the clinical total effective rate and shortening the antiemetic time, Shenling Baizhu Granules + conventional western medicine on shortening the anti-diarrheal time and antipyretic time, Xingpi Yanger Granules + conventional western medicine on improving the negative conversion rate of rotavirus, and Weichang'an Pills + conventional western medicine on reducing the CK-MB level. Limited by the quantity and quality of literature included in this study, the results need to be verified by high-quality RCT with a larger sample size.
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Antieméticos , Antipiréticos , Medicamentos de Ervas Chinesas , Enterite , Rotavirus , Criança , Humanos , Adjuvantes Farmacêuticos , Medicamentos de Ervas Chinesas/uso terapêutico , Enterite/tratamento farmacológico , Metanálise em Rede , Medicamentos sem Prescrição/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Propylene gas is produced worldwide by steam cracking on million-metric-ton scale per year. It serves as a valuable starting material for π-bond functionalization but is rarely applied in transition metal-catalyzed allylic C-H functionalization for fine chemical synthesis. Herein, we report that a newly-developed cationic cyclopentadienyliron dicarbonyl complex allows for the conversion of propylene to its allylic C-C bond coupling products under catalytic conditions. This approach was also found applicable to the allylic functionalization of simple α-olefins with distinctive branched selectivity. Experimental and computational mechanistic studies supported the allylic deprotonation of the metal-coordinated alkene as the turnover-limiting step and led to insights into the multifaceted roles of the newly designed ligand in promoting allylic C-H functionalization with enhanced reactivity and stereoselectivity.
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An iridium-catalyzed stereoselective coupling of allylic ethers and alkynes to generate 3,4-substituted 1,5-enynes is reported. Under optimized conditions, the coupling products are formed with excellent regio-, diastereo-, and enantioselectivities, and the protocol is functional group tolerant. Moreover, we report conditions that allow the reaction to proceed with complete reversal of diastereoselectivity. Mechanistic studies are consistent with an unprecedented dual role for the iridium catalyst, enabling the propargylic deprotonation of the alkyne through π-coordination, as well as the generation of a π-allyl species from the allylic ether starting material.
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Compostos Alílicos , Irídio , Alcinos/química , Compostos Alílicos/química , Catálise , Éteres , Irídio/química , EstereoisomerismoRESUMO
In this study, a bacteriocin PA996 isolated from Pseudomonas azotoformans (P. azotoformans) was purified to homogeneity by ammonium sulphate precipitation and SP-Sepharose column chromatography. P. azotoformans began to grow at 6 h, reached exponential phase at 12-18 h. Bacteriocin PA996 was produced at 18 h and reached a maximum level of 2400 AU/mL. The molecular mass of purified bacteriocin PA996 was estimated by SDS-PAGE and its molecular mass was approximately 50 kDa. By screening in vitro, the bacteriocin PA996 showed an antimicrobial activity against Pasteurella multocida (P. multocida). The bacteriocin PA996 showed antibacterial activity in the range of pH2-10 and it was heat labile. The inhibitory activities were diminished after treatment with proteinase K, trypsin and papain, respectively, while catalase treatment was ineffective. The minimal inhibitory concentration (MIC) and bactericidal kinetics curves showed that the bacteriocin PA996 had a good inhibitory ability against P. multocida. Our data indicate that bacteriocin PA996 could inhibit the growth of P. maltocida and it may have the potential to apply as an alternative therapeutic drug.
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Antibacterianos , Bacteriocinas , Pasteurella multocida/efeitos dos fármacos , Pseudomonas , Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Concentração de Íons de Hidrogênio , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Craving-related brain responses have been associated with the emergence and maintenance of addictions. However, little is known about brain network organizations underlying cravings in internet gaming disorder (IGD). METHODS: Sixty-six IGD subjects and 61 matched individuals with recreational game use (RGU) were scanned while performing a cue-craving task. A recently developed whole-brain analysis approach, connectome-based predictive modelling (CPM) with leave-one-out cross-validation was conducted to identify networks that predicted craving responses in IGD. Then, the craving network was tested in different brain states (cue-craving under deprivation) to investigate replicability. RESULTS: CPM identified an IGD craving network, as indicated by a significant correspondence between predicted and actual craving values (r = 0.49, p < 0.001), characterized by within-network default mode (DMN) connectivity and connectivity between canonical networks implicated in executive/cognitive control (frontoparietal, medial frontal, DMN) and reward responsiveness (subcortical, motor/sensory). Network strength in the cue-craving task during gaming deprivation also predicted IGD craving scores (r = 0.43, p = 0.017), indicating network replication across brain states. CONCLUSIONS: The CPM results demonstrate that individual differences in cognitive, attention, and control network function can predict craving intensities in IGD subjects. These networks may be targets for potential interventions using brain modulation.
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Conectoma , Fissura/fisiologia , Transtorno de Adição à Internet/fisiopatologia , Adulto , Encéfalo/fisiopatologia , Mapeamento Encefálico/métodos , Sinais (Psicologia) , Função Executiva/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Recompensa , Jogos de Vídeo/psicologia , Adulto JovemRESUMO
On the basis of the higher order perturbation formulas of g factors for a 4d1 group in tetragonally compressed octahedra, the g factors, optical absorption, local structure, and their concentration dependences of pentavalent molybdenum in 40PbO-(10 - x)Y2 O3 -50P2 O5 :xMoO3 (1 ≤ x ≤ 5 mol%) glass are uniformly investigated. The experimental optical absorption spectra and g factors for Mo5+ at various concentrations x are reasonably regenerated by using the reasonable exponential concentration functions of the cubic field parameter Dq , covalent factor N, and relative tetragonal compression ratio ρ. The tetragonal compression ratio ρ due to the Jahn-Teller effect was found in the range of 3.8% to 4.2%. The decreasing trend of Dq and N and the increasing trend of ρ with concentration can be interpreted as the fact that the variations of MoO3 and Y2 O3 concentrations lead to the modulations of local structure and electron cloud distribution around Mo5+ , associated with the adjustment of the glass network. The concentration dependence of optical basicity is also analyzed for the above glass systems.