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The thermodynamic favorability of an alkaline solution for the oxidation of water suggests the need for developing hydrogen evolution reaction (HER) catalysts that can function in basic aqueous solutions so that both of the half reactions in overall water splitting can occur in mutually compatible solutions. Although photocatalytic HERs have been reported mostly in acidic solutions and a few at basic pHs in mixed organic aqueous solutions, visible-light driven HER catalyzed by molecular metal complexes in purely alkaline aqueous solutions remains largely unexplored. Here, we report a new cobalt complex with a tetrapyridylamine ligand that catalyzes photolytic HER with turnover number up to 218 000 in purely aqueous solutions at pH 9.0. Density functional theory (DFT) calculations suggested a modified electron transfer (E)-proton transfer (C)-electron transfer (E)-proton transfer (C) (mod-ECEC) pathway for hydrogen production from the protonation of CoII-H species. The remarkable catalytic activity resulting from subtle structural changes of the ligand scaffold highlights the importance of studying structure-function relationships in molecular catalyst design. Our present work significantly advances the development of a molecular metal catalyst for visible-light driven HER in more challenging alkaline aqueous solutions that holds substantial promise in solar-driven water-splitting systems.
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This review introduces multifaceted mutual interactions between molecules containing a catechol moiety and aggregation-prone proteins. The complex relationships between these two molecular species have previously been elucidated primarily in a unidirectional manner, as demonstrated in cases involving the development of catechol-based inhibitors for amyloid aggregation and the elucidation of the role of functional amyloid fibers in melanin biosynthesis. This review aims to consolidate scattered clues pertaining to catechol-based amyloid inhibitors, functional amyloid scaffold of melanin biosynthesis, and chemically designed peptide fibers for providing chemical insights into the role of the local three-dimensional orientation of functional groups in manifesting such interactions. These orientations may play crucial, yet undiscovered, roles in various supramolecular structures.
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Peptídeos beta-Amiloides , Melaninas , Peptídeos beta-Amiloides/metabolismo , Melaninas/química , Amiloide/química , Proteínas Amiloidogênicas , Catecóis/químicaRESUMO
Domain adaptation is a potential method to train a powerful deep neural network across various datasets. More precisely, domain adaptation methods train the model on training data and test that model on a completely separate dataset. The adversarial-based adaptation method became popular among other domain adaptation methods. Relying on the idea of GAN, the adversarial-based domain adaptation tries to minimize the distribution between the training and testing dataset based on the adversarial learning process. We observe that the semi-supervised learning approach can combine with the adversarial-based method to solve the domain adaptation problem. In this paper, we propose an improved adversarial domain adaptation method called Semi-Supervised Adversarial Discriminative Domain Adaptation (SADDA), which can outperform other prior domain adaptation methods. We also show that SADDA has a wide range of applications and illustrate the promise of our method for image classification and sentiment classification problems.
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We have previously shown that ultrasonography can detect hyperechogenic crystal deposits in the kidney medulla of patients with gout. In this cross-sectional study we investigated the frequency and clinical correlates of hyperechogenic kidney medulla in 502 consecutive primary consultants for gout (ACR/EULAR criteria) at the Vien Gut medical center in Ho Chi Minh City, Vietnam. None of these patients received urate-lowering drugs. Kidney medulla echogenicity on B-mode ultrasonography was compared to that of the kidney cortex. Overall, 36% patients showed a hyperechoic pattern of Malpighi pyramids. On univariate analysis, the pattern was significantly associated with age, estimated gout duration, steroid-dependency, clinical tophi, urate arthropathy, double contour thickness at the scanned joints, coronary heart disease, arterial hypertension, hyperuricemia, proteinuria, leukocyturia, and decreased estimated glomerular filtration rate. On multivariable analysis, the hyperechoic pattern was associated with estimated disease duration, clinical tophi, urate arthropathy, double contour thickness and decreased estimated glomerular filtration rate. No hyperechoic pattern was observed in 515 consecutive consultants without gout. Thus, hyperechoic kidney medulla was frequently demonstrated in Vietnamese patients with tophaceous gout and associated with features of tubulointerstitial nephritis. This finding revives the hypothesis of microcrystalline nephropathy of gout, predominantly seen in untreated gouty patients, which could be an important target for urate-lowering therapy.
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Gota , Hiperuricemia , Estudos Transversais , Gota/diagnóstico por imagem , Gota/tratamento farmacológico , Gota/epidemiologia , Humanos , Medula Renal , Ácido ÚricoRESUMO
Polydopamine (PD) and melanin species are chemically complex systems, the formation and properties of which are incompletely understood. Inspired by the role of functional amyloids in melanin biosynthesis, this paper examines the influences of the supramolecular structure of amyloids on oxidative polymerization of dopamine. Kinetic analyses on the formation of PD species in the presence of hen egg white lysozyme (HEWL) fibers or soluble HEWL revealed that both forms gave rise to the total quantity of PD species, but the rate of their formation could be accelerated only by the amyloid form. PD species formed with HEWL fibers showed a morphology of bundled fibers, whereas those with soluble HEWL had a mesh-like structure. Amyloid fibers of recombinant Pmel17 had properties similar to those of HEWL fibers in modulating PD formation. The results presented here suggest how nature designs functionality with an amyloid structure and can help understand and engineer chemistries of other functional amyloids.
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Amiloide/química , Indóis/química , Melaninas/química , Muramidase/química , Polímeros/química , Amiloide/metabolismo , Animais , Cinética , Muramidase/metabolismoRESUMO
A CoMoS composite is synthesized to combine the benefits of cobalt and molybdenum sulfides as an anodic material for advanced lithium-ion batteries (LIBs). The synthesis is accomplished using a simple two-step hydrothermal method and the resulting CoMoS nanocomposites are subsequently encapsulated in a carbonized polydopamine shell. The synthesis procedure exploited the self-polymerization ability of dopamine to create nitrogen-doped carbon-coated cobalt molybdenum sulfide, denoted as CoMoS@NC. Notably, the de-lithiation capacity of CoMoS and CoMoS@NC is 420 and 709 mAh gâ»1, respectively, even after 100 lithiation/de-lithiation cycles at a current density of 200 mA gâ»1. Furthermore, excellent capacity retention ability is observed for CoMoS@NC as it withstood 600 consecutive lithiation/de-lithiation cycles with 94% capacity retention. Moreover, a LIB full-cell assembly incorporating the CoMoS@NC anode and an NMC-532 cathode is subjected to comprehensive electrochemical and practical tests to evaluate the performance of the anode. In addition, the density functional theory showcases the increased lithium adsorption for CoMoS@NC, supporting the experimental findings. Hence, the use of dopamine as a nitrogen-doped carbon shell enhanced the performance of the CoMoS nanocomposites in experimental and theoretical tests, positioning the material as a strong candidate for LIB anode.
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The JNET classification, combined with magnified narrowband imaging (NBI), is essential for predicting the histology of colorectal polyps and guiding personalized treatment strategies. Despite its recognized utility, the diagnostic efficacy of JNET classification using NBI with dual focus (DF) magnification requires exploration in the Vietnamese context. This study aimed to investigate the diagnostic performance of the JNET classification with the NBI-DF mode in predicting the histology of colorectal polyps in Vietnam. A cross-sectional study was conducted at the University Medical Center in Ho Chi Minh City, Vietnam. During real-time endoscopy, endoscopists evaluated the lesion characteristics and recorded optical diagnoses using the dual focus mode magnification according to the JNET classification. En bloc lesion resection (endoscopic or surgical) provided the final pathology, serving as the reference standard for optical diagnoses. A total of 739 patients with 1353 lesions were recruited between October 2021 and March 2023. The overall concordance with the JNET classification was 86.9%. Specificities and positive predictive values for JNET types were: type 1 (95.7%, 88.3%); type 2A (81.4%, 90%); type 2B (96.6%, 54.7%); and type 3 (99.9%, 93.3%). The sensitivity and negative predictive value for differentiating neoplastic from non-neoplastic lesions were 97.8% and 88.3%, respectively. However, the sensitivity for distinguishing malignant from benign neoplasia was lower at 64.1%, despite a specificity of 95.9%. Notably, the specificity and positive predictive value for identifying deep submucosal cancer were high at 99.8% and 93.3%. In Vietnam, applying the JNET classification with NBI-DF demonstrates significant value in predicting the histology of colorectal polyps. This classification guides treatment decisions and prevents unnecessary surgeries.
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Pólipos do Colo , Colonoscopia , Imagem de Banda Estreita , Humanos , Imagem de Banda Estreita/métodos , Estudos Transversais , Vietnã , Feminino , Masculino , Pessoa de Meia-Idade , Pólipos do Colo/diagnóstico por imagem , Pólipos do Colo/classificação , Pólipos do Colo/diagnóstico , Pólipos do Colo/patologia , Colonoscopia/métodos , Idoso , Adulto , Sensibilidade e Especificidade , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/classificação , Neoplasias Colorretais/patologia , Valor Preditivo dos Testes , População do Sudeste Asiático , População do Leste AsiáticoRESUMO
Eph receptors, the largest known family of receptor tyrosine kinases, and ephrin ligands have been implicated in a variety of human cancers. The novel bidirectional signaling events initiated by binding of Eph receptors to their cognate ephrin ligands modulate many cellular processes such as proliferation, metastasis, angiogenesis, invasion, and apoptosis. The relationships between the abundance of a unique subset of Eph receptors and ephrin ligands with associated cellular processes indicate a key role of these molecules in tumorigenesis. The combinatorial expression of these molecules converges on MAP kinase and/or AKT/mTOR signaling pathways. The intracellular target proteins of the initial signal may, however, vary in some cancers. Furthermore, we have also described the commonality of up- and down-regulation of individual receptors and ligands in various cancers. The current state of research in Eph receptors illustrates MAP kinase and mTOR pathways as plausible targets for therapeutic interventions in various cancers.
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Neoplasias , Receptores da Família Eph , Humanos , Receptores da Família Eph/química , Receptores da Família Eph/metabolismo , Efrinas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ligantes , Neoplasias/metabolismo , Proteínas Quinases Ativadas por Mitógeno , Serina-Treonina Quinases TORRESUMO
The formation of dimer [(µ-Cl)Rh-(κ3(P,Si,Si)PhP(o-C6H4CH2SiiPr2)(o-C6H4CH2SiiPrnPr))]2 (Rh-3) with an n-propyl group on one of the silicon atoms as a minor product was affected by the reaction of [RhCl(COD)]2 with proligand PhP(o-C6H4CH2SiHiPr2)2, L1. The major product of the reaction was monomeric 14-electron Rh(III) complex [ClRh(κ3(P,Si,Si)PhP(o-C6H4CH2SiiPr2)2)] (Rh-1). Computations revealed that the monomer-dimer equilibrium is shifted toward the monomer with four isopropyl substituents on the two Si atoms of the ligand as in Rh-1; conversely, the dimer is favored with only one n-propyl as in Rh-3, and with less bulky alkyl substituents such as in [ClRh(κ3(P,Si,Si)PhP(o-C6H4CH2SiMe2)2]2 (Rh-2). Computations on the mechanism of formation of Rh-3 directly from [RhCl(COD)]2 are in agreement with the experimental findings and it is found to be less energetic than if stemming from Rh-1. Additionally, a Si-O-Si complex, [µ-Cl-Rh{κ3(P,Si,C)PPh(o-C6H4CH2SiiPrO SiiPr2CH-o-C6H4)}]2, Rh-4, is generated from the reaction of Rh-1 with adventitious water as a result of intramolecular C-H activation.
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Immunothrombosis has emerged as a dominant pathological process exacerbating morbidity and mortality in acute- and long-COVID-19 infections. The hypercoagulable state is due in part to immune system dysregulation, inflammation and endothelial cell damage, as well as a reduction in defense systems. One defense mechanism in particular is glutathione (GSH), a ubiquitously found antioxidant. Evidence suggests that reduction in GSH increases viral replication, pro-inflammatory cytokine release, and thrombosis, as well as decreases macrophage-mediated fibrin removal. The collection of adverse effects as a result of GSH depletion in states like COVID-19 suggest that GSH depletion is a dominant mechanism of immunothrombosis cascade. We aim to review the current literature on the influence of GSH on COVID-19 immunothrombosis pathogenesis, as well as the beneficial effects of GSH as a novel therapeutic for acute- and long-COVID-19.
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COVID-19 , Humanos , COVID-19/prevenção & controle , Tromboinflamação , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda , Glutationa/uso terapêuticoRESUMO
Research has shown that obesity increases the risk for type 2 diabetes mellitus (Type 2 DM) by promoting insulin resistance, increases serum estrogen levels by the upregulation of aromatase, and promotes the release of reactive oxygen species (ROS) by macrophages. Increased circulating glucose has been shown to activate mammalian target of rapamycin (mTOR), a significant signaling pathway in breast cancer pathogenesis. Estrogen plays an instrumental role in estrogen-receptor-positive breast cancers. The role of ROS in breast cancer warrants continued investigation, in relation to both pathogenesis and treatment of breast cancer. We aim to review the role of obesity in breast cancer pathogenesis and novel therapies mediating obesity-associated breast cancer development. We explore the association between body mass index (BMI) and breast cancer incidence and the mechanisms by which oxidative stress modulates breast cancer pathogenesis. We discuss the role of glutathione, a ubiquitous antioxidant, in breast cancer therapy. Lastly, we review breast cancer therapies targeting mTOR signaling, leptin signaling, blood sugar reduction, and novel immunotherapy targets.
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Diabetes Mellitus Tipo 2 , Neoplasias , Humanos , Espécies Reativas de Oxigênio , Obesidade/complicações , Estrogênios , Serina-Treonina Quinases TORRESUMO
A new synthesis of N-fused tetracyclic indole derivatives and their related polycyclic analogues has been developed based on ruthenium(II)-catalyzed C-H activation and intramolecular hydroarylation. A series of polycyclic indoles with a 3-formyl group have been prepared in good to high yields. Various aliphatic and aromatic amines have been studied to form a transient directing group with the aldehyde for the catalytic process. A significant impact of the structures of the aromatic amines was identified, and 1-naphthylamine was shown to enable the catalytic process. DFT computations were performed to gain further insight into the role of the transient directing groups.
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In this paper, we develop a method for Friedel-Crafts acylation using metal triflate in deep eutectic solvents. Various metal triflates were tested and provided good to excellent yields of corresponding ketone products. The density functional theory calculation revealed the metal effects on the formation of active intermediate acylium triflate as well as the acidic condition. The metal triflate in the deep eutectic solvent can be recovered and reused with a little loss in the catalytic activity.
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The MOF material NU-1000 was employed to host Ni tripodal complexes prepared from new organometallic precursors [HNi(κ4(E,P,P,P)-E(o-C6H4CH2PPh2)3], E = Si (Ni-1), Ge (Ni-2). The new heterogeneous catalytic materials, Ni-1@NU-1000 and Ni-2@NU-1000, show the advantages of both homogeneous and heterogeneous catalysts. They catalyze the hydroboration of aldehydes and ketones more efficiently than the homogeneous Ni-1 and Ni-2, under aerobic conditions and show recyclability.
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OBJECTIVE: The coexistence of calcium pyrophosphate dihydrate (CPPD) and monosodium urate monohydrate crystals in gouty tophi has rarely been reported. We undertook this study to investigate CPPD crystal deposits in a series of surgically removed gouty tophi and to identify factors associated with these deposits. METHODS: Twenty-five tophi from 22 gout patients were analyzed using polarized light microscopy, field emission scanning electron microscopy (FESEM), and µ Fourier transform infrared (µFTIR) spectroscopy. RESULTS: Tophi consisted of multiple lobules separated by fibrous septa and surrounded by a foreign-body giant cell reaction. CPPD crystal aggregates were identified in 9 of 25 tophi from 6 patients. CPPD crystals were dispersed or highly compacted, localized at the edge or inside the tophus lobules, with some lobules completely filled with crystals. Both monoclinic and triclinic CPPD crystal phases were identified using FESEM and µFTIR. Compared to patients without CPPD, those with CPPD-containing tophi were older (mean 60.5 years versus 47.2 years; P = 0.009), and had longer-term gout duration (mean 17.0 years versus mean 9.0 years; P < 0.05) and tophi duration (mean 10.0 years versus mean 4.6 years; P < 0.01). None of the patients had radiographic chondrocalcinosis of the knee or wrist. CONCLUSION: CPPD crystal formation seems to be a late and frequent event of tophus maturation, occurring more frequently with aging, and could contribute to the speed of tophus dissolution and the apparent persistence of tophus sometimes observed even after effective, long-lasting urate-lowering therapy.
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Pirofosfato de Cálcio/análise , Gota/patologia , Ácido Úrico/análise , Adulto , Fatores Etários , Idoso , Humanos , Masculino , Microscopia Eletrônica de Varredura , Microscopia de Polarização , Pessoa de Meia-Idade , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de TempoRESUMO
OBJECTIVE: The aim of this study was to investigate risk factors for cutaneous adverse reactions (CARs) in Kinh Vietnamese. METHODS: All patients were prospectively recruited in Ho Chi Minh City. Presence of the HLA-B*58:01 allele was determined by real-time PCR-sequence-specific amplification by using the PG5801 Detection Kit (Pharmigene, Taipei). Patients with severe (SCARs) and mild (MCARs) CARs and controls were compared for differences in features prospectively collected, and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. RESULTS: On comparing 32 patients with SCARs and 395 tolerant controls, we identified eight strong risk factors: increased age (OR 15.1 [95% CI 5.8-40.1], P < 0.0001), female sex (OR 333 [40-43,453], P < 0.0001), allopurinol for asymptomatic hyperuricemia (OR 955 [120-125,847], P < 0.0001), allopurinol starting dose > 150 mg (OR 316 [101-122], P < 0.0001), diuretics intake (OR 304 [35-40,018], P < 0.0001), eGFR < 60 ml/min/1.73 m2 (OR 100 [32-353], P < 0.0001), history of allopurinol-induced skin reaction (OR 78 [6-10,808], P = 0.004), and HLA-B*58:01 carriage (OR 147 [45-746], P < 0.0001). HLA-B*58:01 allele frequency in controls was 7.3%. For MCARs (n = 74), risk factors were eGFR < 60 ml/min/1.73 m2 (OR 4.9 [1.61-14.6], P = 0.006), history of allopurinol-induced skin reaction (OR 27 [2-3777], P = 0.01), and asymptomatic hyperuricemia (OR 27 [2-3777], P = 0.01). CONCLUSION: This study confirmed 8 risk factors, including HLA-B*58:01, for SCARs and identified 3 risk factors for MCARs in Kinh Vietnamese. HLA-B*58:01 genotyping could guide the indication for allopurinol in Kinh Vietnamese patients with gout.
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Alopurinol , Antígenos HLA-B , Alopurinol/efeitos adversos , Povo Asiático , Estudos de Casos e Controles , Feminino , Supressores da Gota/efeitos adversos , Humanos , Fatores de RiscoRESUMO
This paper deals with the newly found antibacterial efficiency of coral-like crystalline Rh nanoplates. Rh nanoplates with rough surface morphology synthesized by inverse-directional galvanic replacement exhibited highly enhanced antibacterial efficiency compared to Rh3+ ion and Rh nanospheres. The observed antibacterial efficiency was comparable to Ag nanoplates, a well-known anticancer nano-agent. Results clearly demonstrate that the composition and morphology of a nanostructure play significant roles in antibacterial effects.
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From an EtOAc-soluble fraction of the stem barks of Swintonia floribunda (Anacardiaceae), one new dimeric alkylresorcinol named integracin E (1), together with 4 known compounds (2-5) were isolated. Their chemical structures were elucidated based on the spectroscopic data interpretation. The absolute configuration of 1 was determined by the specific rotation analysis of its acid-catalyzed hydrolysis product. Compound 1 showed potent tyrosinase inhibitory activity with an IC50 value of 48.2 µM.
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Anacardiaceae/química , Casca de Planta/química , Resorcinóis/isolamento & purificação , Dimerização , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Concentração Inibidora 50 , Estrutura Molecular , Monofenol Mono-Oxigenase/antagonistas & inibidores , Análise EspectralRESUMO
Several herbal remedies have been used as topical agents to cure burn wound, one of the most common injuries in worldwide. In this study, we investigated the potential use of Cleistocalyx operculatus essential oil to treat the burn wound. We identified a total of 13 bioactive compounds of essential oil, several of which exhibited the anti-inflammatory and antimicrobial activities. Furthermore, the essential oil showed the antibacterial effect against S. aureus but not with P. aeruginosa. The supportive effect of essential oil on burn wound healing process also has been proven. Among three groups of mice, wound contraction rate of essential oil treated group (100%) was significantly higher than tamanu oil treated (79%) and control mice (71%) after 20 days (0.22 ± 0.03 versus 0.31 ± 0.02 cm2, resp., p < 0.05). Histological studies revealed that burn wounds treated with essential oil formed a complete epidermal structure, thick and neatly arranged fibers, and scattered immune cells in burn wound. On the contrary, saline treated burn wound formed uneven epidermal layer with necrotic ulcer, infiltration of immune cells, and existence of granulation tissue. This finding demonstrated Cleistocalyx operculatus essential oil as promising topical dermatological agent to treat burn wound.
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Single clove garlic is the product of atypical bulbing process of garlic under specific conditions. Therefore, the number of researches on single clove garlic bioactivity is limited. Recently, the hepatoprotective effect of single clove garlic has been demonstrated. In this study, we investigated amelioration of single clove black garlic aqueous extract, a processed product from single clove garlic, on dyslipidemia and hepatitis induced by chronic administration of CCl4. Mice were randomly divided into four groups: control, extract control, CCl4 intoxication, and coadministrated CCl4 and extract group. Mice were orally given a dose of 1 ml/kg body weight of CCl4 for 28 days twice a week to establish chronic liver injury model. To evaluate the hepatoprotective effect of single clove black garlic, mice were cotreated with CCl4 and single clove black garlic extract (200 mg/kg body weight) via gastric gauge for 30 days. Cotreatment with CCl4 and extract could improve the changes of body weight, liver weight, and relative liver weight as compared to CCl4 intoxicated mice. Single clove black garlic ameliorated dyslipidemia and the elevation of ALT and AST levels induced by chronic CCl4 intoxication. Histological studies revealed that single clove black garlic could prevent mononuclear cells infiltration and hepatocyte necrosis.