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GLUT7 is a Class II glucose transporter predominantly expressed at the apical membrane of enterocytes in the small intestine. Here, we report the cryo-EM structure of nanodisc-reconstituted human GLUT7 in the apo state at 3.3 Å resolution. Our atomic model reveals a typical major facilitator superfamily fold, with the substrate-binding site open to the extracellular side of the membrane. Despite the nearly identical conformation to its closest family member, rat GLUT5, our structure unveils distinct features of the substrate-binding cavity that may influence substrate specificity and binding mode. A homology model of the inward-open human GLUT7 indicates that similar to other members of the GLUT family, it may undergo a global rocker-switch-like reorientation of the transmembrane bundles to facilitate substrate translocation across the membrane. Our work enhances the current structural understanding of the GLUT family, and lays a foundation for rational design of regulators of GLUTs and other sugar transporters.
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Background: Ankle fusion is considered a treatment of choice for end-stage ankle arthritis when a total ankle replacement procedure is not indicated. However, the potential risk of secondary arthritis in the adjacent joint after ankle fusion raises arguments on whether preserving the adjacent joint during an isolated tibiotalar (TT) fusion brings about any future benefits with regard to pain and gait discomfort. In this study, we intended to present midterm results following TT or tibiotalocalcaneal (TTC) fusion using an Ilizarov external fixator and to investigate whether spontaneous fusion occurred in the subtalar or midtarsal joint. Methods: This is a retrospective observational study. Medical records of patients who underwent TT or TTC fusion using an Ilizarov external fixator for substantial bone defects around the ankle joint between 1994 and 2018 were manually searched. Forty-one patients were included and the status of the joints adjacent to the fusion site was evaluated in radiographic examinations. Results: Of the 34 patients who underwent TT fusion, 30 patients (88.3%) had a spontaneous fusion in the adjacent joints. Specifically, 11 patients (29.4%) had subtalar joint fusion and 19 patients (55.9%) had both midtarsal joint and subtalar joint fusion. In TTC fusion, the midtarsal joint was spontaneously fused in all 7 patients. Conclusions: In this study, we observed spontaneous adjacent joint fusion following TT or TTC fusion using an Ilizarov external fixator for substantial bone defects around the ankle joint. Although a careful approach should be made since patients treated in this study may not represent typical candidates that need primary joint-sacrificing procedures, we believe that this study may draw attention from surgeons concerned about the fate of the adjacent joint status after TT or TTC fusion.
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Articulação do Tornozelo , Técnica de Ilizarov , Humanos , Estudos Retrospectivos , Feminino , Masculino , Pessoa de Meia-Idade , Articulação do Tornozelo/cirurgia , Técnica de Ilizarov/instrumentação , Idoso , Artrodese/métodos , Artrodese/instrumentação , Fixadores Externos , Adulto , Articulação Talocalcânea/cirurgia , Calcâneo/cirurgiaRESUMO
Quercetin (QC), a naturally occurring bioflavonoid found in various fruits and vegetables, possesses many potential health benefits, primarily attributed to its robust antioxidant properties. The generation of oxidative stress in bone cells is a key modulator of their physiological behavior. Moreover, oxidative stress status influences the pathophysiology of mineralized tissues. Increasing scientific evidence demonstrates that manipulating the redox balance in bone cells might be an effective technique for developing bone disease therapies. The QC antioxidant abilities in skeletal muscle significantly enhance muscle regeneration and reduce muscle atrophy. In addition, QC has been shown to have protective effects against oxidative stress, inflammation, apoptosis, and matrix degradation in tendons, helping to maintain the structural integrity and functionality of tendons. Thus, the antioxidant properties of QC might be crucial for addressing age-related musculoskeletal disorders like osteoporosis, sarcopenia, and tendon-related inflammatory conditions. Understanding how QC influences redox signaling pathways involved in musculoskeletal disorders, including their effect on bone, muscle, and tendon differentiation, might provide insights into the diverse advantages of QC in promoting tissue regeneration and preventing cellular damage. Therefore, this study reviewed the intricate relationship among oxidative stress, inflammation, and tissue repair, affected by the antioxidative abilities of QC, in age-related musculoskeletal tissues to improve the overall health of bones, muscles, and tendons of the skeletal system. Also, reviewing the ongoing clinical trials of QC for musculoskeletal systems is encouraging. Given the positive effect of QC on musculoskeletal health, further scientific investigations and controlled human intervention studies are necessary to explore the therapeutic potential to its optimum strength.
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INTRODUCTION: This multicenter phase I/IIa study aimed to determine the recommended phase II dose (RP2D) and evaluate the safety and preliminary efficacy of liposomal irinotecan (nal-IRI), oxaliplatin, and S-1 (NASOX) as first-line treatment for advanced pancreatic adenocarcinoma. METHODS: Patients with locally advanced or metastatic pancreatic adenocarcinoma without prior systemic treatment for advanced disease, aged ≥ 19 years, with measurable disease, and Eastern Cooperative Oncology Group performance status of 0-1 were eligible. The primary endpoints were to determine the dose-limiting toxicity (DLT) in the phase I cohort and overall response rate (ORR) in the phase IIa cohort. The intention-to-treat (ITT) analysis included patients who received the RP2D. RESULTS: In phase I, seven patients were screened, and six were assessed for DLT. None experienced DLT during the first cycle. The RP2D was determined as nal-IRI 50 mg/m2 and oxaliplatin 60 mg/m2 on day 1, S-1 40 mg/m2 twice daily on days 1-7 every 14 days. For the ITT (N = 41; 7, and 34 from phases I and IIa, respectively), the most common grade 3-4 treatment-emergent adverse events were neutropenia (31.7 %), enterocolitis (9.8 %), anorexia (7.3 %), and diarrhea (2.4 %). The ORR was 58.5 % (1 complete, and 23 partial responses). Two underwent conversion surgery; both achieved R0 resection. With median follow-up of 17.5 months, median progression-free survival was 6.5 months (95 % confidence interval [CI], 5.0-8.1) and median overall survival was 11.4 months (95 % CI, 9.8-15.5). CONCLUSION: NASOX exhibited a manageable safety profile and encouraging efficacy outcomes consistent with NALIRIFOX, showing potential to replace infusional 5-fluorouracil with oral S-1 in the triplet regimen.
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Adenocarcinoma , Protocolos de Quimioterapia Combinada Antineoplásica , Combinação de Medicamentos , Irinotecano , Oxaliplatina , Ácido Oxônico , Neoplasias Pancreáticas , Tegafur , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/mortalidade , Masculino , Irinotecano/uso terapêutico , Irinotecano/administração & dosagem , Oxaliplatina/administração & dosagem , Oxaliplatina/uso terapêutico , Oxaliplatina/efeitos adversos , Feminino , Pessoa de Meia-Idade , Ácido Oxônico/administração & dosagem , Ácido Oxônico/uso terapêutico , Ácido Oxônico/efeitos adversos , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/secundário , Adenocarcinoma/patologia , Adenocarcinoma/mortalidade , Tegafur/administração & dosagem , Tegafur/uso terapêutico , Tegafur/efeitos adversos , Lipossomos , Adulto , Intervalo Livre de ProgressãoRESUMO
Background/Aim: Extreme hyperbilirubinemia is occasionally observed in intensive care unit (ICU) and non-ICU settings. This study examined the etiologies of extreme hyperbilirubinemia (bilirubin level ≥12 mg/dL) and the factors associated with the 30-day mortality. Methods: This retrospective observational cohort study identified 439 patients with extreme hyperbilirubinemia at the Gyeongsang National University Changwon Hospital between 2016 and 2020. The patients were classified into three groups and 11 diseases according to their etiology. The risk factors associated with 30-day mortality at the baseline were investigated using the Cox proportional hazards model. Results: Of 439 patients with extreme hyperbilirubinemia, 287, 78, and 74 were in the liver cirrhosis/malignancy group, the ischemic injury group, and the benign hepatobiliary-pancreatic etiological group, respectively, with corresponding 30-day mortality rates of 42.9%, 76.9%, and 17.6%. The most common disease leading to hyperbilirubinemia was a pancreatobiliary malignancy (28.7%), followed by liver cirrhosis (17.3%), hepatocellular carcinoma (10.9%), and liver metastases (8.4%). The etiologies of hyperbilirubinemia, obstructive jaundice, infection, albumin level, creatinine level, and prothrombin time-international normalized ratio were independently associated with the 30-day mortality. Conclusions: This study suggests three etiologies of extreme hyperbilirubinemia in the ICU and non-ICU settings. The prognosis of patients with extreme hyperbilirubinemia depends largely on the etiology and the presence of obstructive jaundice.
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Bilirrubina , Hiperbilirrubinemia , Cirrose Hepática , Modelos de Riscos Proporcionais , Humanos , Estudos Retrospectivos , Feminino , Masculino , Hiperbilirrubinemia/complicações , Pessoa de Meia-Idade , República da Coreia , Idoso , Fatores de Risco , Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico , Cirrose Hepática/mortalidade , Cirrose Hepática/patologia , Bilirrubina/sangue , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/diagnóstico , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/diagnóstico , Adulto , Unidades de Terapia IntensivaRESUMO
Insitu stabilization and phytoextraction are considered as two convenient and effective technologies for the remediation of toxic elements (TEs) in soils. However, the effectiveness of these two remediation technologies together on the bioavailability and phytoextraction of TEs in field trials has not been explored yet. Specifically, the remediation potential of fly ash (FA; as stabilizing agent) and ryegrass (as a TE accumulator) intercropped with a target crop for soil polluted with multiple TEs has not been investigated yet, particularly in long-term field trials. Therefore, in this study, a six-month combined remediation field experiment of FA stabilization and/or ryegrass intercropping (IR) was carried out on the farmland soils contaminated with As, Cd, Cr, Cu, Hg, Ni, Pb and Zn where Zanthoxylumbungeanum (ZB) trees as native crops were grown for years. The treatments include soil cultivated alone with ZB untreated- (control) and treated-with FA (FA), produced by burning lignite in Shaanxi Datong power plant, China, soil cultivated with ZB and ryegrass untreated- (IR) and treated-with FA (FA + IR). This was underpinned by a large-scale survey in Daiziying (China), which showed that the topsoils were polluted by Cd, Cu, Hg and Pb, and that Hg and Pb contents in the Zanthoxylumbungeanum fruits exceeded their allowable limits. The TEs contents in the studied FA were lower than their total element contents in the soil. The DTPA-extractable TEs contents of the remediation modes were as follows: FA < FA + IR < IR < control. Notably, TEs contents in the ZB fruits were lowest under the FA + IR treatment, which were decreased by 27.6% for As, 42.3% for Cd, 16.7% for Cr, 30.5% for Cu, 23.1% for Hg, 15.5% for Ni, 33.2% for Pb and 38.1% for Zn compared with the control treatment. Whereas the FA + IR treatment enhanced TEs contents in ryegrass shoots and roots, and the TEs contents in ryegrass shoots were below their regulatory limits for fodder crops. The findings confirmed that the combined remediation strategy, i.e., FA (with low content of TEs) stabilization effect and intercropping of ZB (target crop) and ryegrass (accumulating plant) could provide a prospective approach to produce target plants within safe TEs thresholds with greater economic benefits, while remediating soils polluted with multiple TEs and mitigating the potential ecological and human health risk. Those results are of great applicable concern.
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Cinza de Carvão , Lolium , Poluentes do Solo , Solo , Lolium/crescimento & desenvolvimento , Lolium/metabolismo , Poluentes do Solo/metabolismo , Solo/química , China , Recuperação e Remediação Ambiental/métodos , Biodegradação Ambiental , Metais PesadosRESUMO
Reverse zoonosis reveals the process of transmission of a pathogen through the human-animal interface and the spillback of the zoonotic pathogen. In this article, we methodically demonstrate various aspects of reverse zoonosis, with a comprehensive discussion of SARS-CoV-2 and MPXV reverse zoonosis. First, different components of reverse zoonosis, such as humans, different pathogens, and numerous animals (poultry, livestock, pets, wild animals, and zoo animals), have been demonstrated. Second, it explains the present status of reverse zoonosis with different pathogens during previous occurrences of various outbreaks, epidemics, and pandemics. Here, we present 25 examples from literature. Third, using several examples, we comprehensively illustrate the present status of the reverse zoonosis of SARS-CoV-2 and MPXV. Here, we have provided 17 examples of SARS-CoV-2 reverse zoonosis and two examples of MPXV reverse zoonosis. Fourth, we have described two significant aspects of reverse zoonosis: understanding the fundamental aspects of spillback and awareness. These two aspects are required to prevent reverse zoonosis from the current infection with two significant viruses. Finally, the One Health approach was discussed vividly, where we urge scientists from different areas to work collaboratively to solve the issue of reverse zoonosis.
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COVID-19 , SARS-CoV-2 , Zoonoses , Animais , Humanos , COVID-19/transmissão , COVID-19/epidemiologia , COVID-19/virologia , Zoonoses/transmissão , Zoonoses/virologia , Monkeypox virus/genética , Monkeypox virus/patogenicidade , Monkeypox virus/isolamento & purificação , Animais Selvagens/virologia , Saúde Única , Mpox/transmissão , Mpox/epidemiologia , Mpox/virologiaRESUMO
ATP-binding cassette transporter B6 (ABCB6), a protein essential for heme biosynthesis in mitochondria, also functions as a heavy metal efflux pump. Here, we present cryo-electron microscopy structures of human ABCB6 bound to a cadmium Cd(II) ion in the presence of antioxidant thiol peptides glutathione (GSH) and phytochelatin 2 (PC2) at resolutions of 3.2 and 3.1 Å, respectively. The overall folding of the two structures resembles the inward-facing apo state but with less separation between the two halves of the transporter. Two GSH molecules are symmetrically bound to the Cd(II) ion in a bent conformation, with the central cysteine protruding towards the metal. The N-terminal glutamate and C-terminal glycine of GSH do not directly interact with Cd(II) but contribute to neutralizing positive charges of the binding cavity by forming hydrogen bonds and van der Waals interactions with nearby residues. In the presence of PC2, Cd(II) binding to ABCB6 is similar to that observed with GSH, except that two cysteine residues of each PC2 molecule participate in Cd(II) coordination to form a tetrathiolate. Structural comparison of human ABCB6 and its homologous Atm-type transporters indicate that their distinct substrate specificity might be attributed to variations in the capping residues situated at the top of the substrate-binding cavity.
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Transportadores de Cassetes de Ligação de ATP , Humanos , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/ultraestrutura , Sítios de Ligação , Cádmio/metabolismo , Cádmio/química , Microscopia Crioeletrônica , Glutationa/metabolismo , Glutationa/química , Modelos Moleculares , Fitoquelatinas/metabolismo , Fitoquelatinas/química , Ligação Proteica , Conformação ProteicaRESUMO
Iron/chromium hydroxide coprecipitation controls the fate and transport of toxic chromium (Cr) in many natural and engineered systems. Organic coatings on soil and engineered surfaces are ubiquitous; however, mechanistic controls of these organic coatings over Fe/Cr hydroxide coprecipitation are poorly understood. Here, Fe/Cr hydroxide coprecipitation was conducted on model organic coatings of humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA). The organics bonded with SiO2 through ligand exchange with carboxyl (-COOH), and the adsorbed amounts and pKa values of -COOH controlled surface charges of coatings. The adsorbed organic films also had different complexation capacities with Fe/Cr ions and Fe/Cr hydroxide particles, resulting in significant differences in both the amount (on HA > SA(-COOH) â« BSA(-NH2)) and composition (Cr/Fe molar ratio: on BSA(-NH2) â« HA > SA(-COOH)) of heterogeneous precipitates. Negatively charged -COOH attracted more Fe ions and oligomers of hydrolyzed Fe/Cr species and subsequently promoted heterogeneous precipitation of Fe/Cr hydroxide nanoparticles. Organic coatings containing -NH2 were positively charged at acidic pH because of the high pKa value of the functional group, limiting cation adsorption and formation of coprecipitates. Meanwhile, the higher local pH near the -NH2 coatings promoted the formation of Cr(OH)3. This study advances fundamental understanding of heterogeneous Fe/Cr hydroxide coprecipitation on organics, which is essential for successful Cr remediation and removal in both natural and engineered settings, as well as the synthesis of Cr-doped iron (oxy)hydroxides for material applications.
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Cromo , Hidróxidos , Ferro , Hidróxidos/química , Ferro/química , Cromo/química , Soroalbumina Bovina/química , Adsorção , Substâncias Húmicas , Água/química , Precipitação Química , Alginatos/químicaRESUMO
In this work, the practical utility of constructed wetlands (CWs) is described as a promising treatment option for micropollutants (MPs) in wastewater with the aid of their eco-friendly, low-energy, economically feasible, and ecologically sustainable nature. This paper offers a comprehensive review on CW technology with respect to the key strategies for MP removal such as phytoremediation, substrate adsorption, and microbial degradation. It explores the important factors controlling the performance of CWs (e.g., in terms of configurations, substrates, plant-microbe interactions, temperature, pH, oxygen levels, hydraulic loading rate, and retention time) along with the discussions on the pivotal role of microbial populations in CWs and plant-microbe cooperative remediation dynamics, particularly in relation to diverse organic MP patterns in CWs. As such, this review aims to provide valuable insights into the key strategies for optimizing MP treatment and for enhancing the efficacy of CW systems. In addition, the process-based models of constructed wetlands along with the numerical simulations based on the artificial neural network (ANN) method are also described in association with the data exploratory techniques. This work is thus expected to help open up new possibilities for the application of plant-microbe cooperative remediation approaches against diverse patterns of organic MPs present in CWs.
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Biodegradação Ambiental , Eliminação de Resíduos Líquidos , Águas Residuárias , Poluentes Químicos da Água , Áreas Alagadas , Águas Residuárias/química , Poluentes Químicos da Água/análise , Eliminação de Resíduos Líquidos/métodos , AdsorçãoRESUMO
Reactions of mineral surfaces with dissolved metal ions at far-from-equilibrium conditions can deviate significantly from those in near-equilibrium systems due to steep concentration gradients, ion-surface interactions, and reactant transport effects that can lead to emergent behavior. We explored the effect of dissolved Pb2+ on the dissolution rate and topographic evolution of calcite (104) surfaces under far-from-equilibrium acidic conditions (pH 3.7) in a confined single-pass laminar-flow geometry. Operando measurements by digital holographic microscopy were conducted over a range of Pb2+ concentrations ([Pb2+] = 0 to 5 × 10-2 M) and flow velocities (v = 1.67-53.3 mm s-1). Calcite (104) surface dissolution rates decreased with increasing [Pb2+]. The inhibition of dissolution and the emergence of unique topographic features, including micropyramids, variable etch pit shapes, and larger scale topographic patterns, became increasingly apparent at [Pb2+] ≥ 5 × 10-3 M. A better understanding of such dynamic reactivity could be crucial for constructing accurate models of geochemical transport in aqueous carbonate systems.
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Background: Myelin oligodendrocyte glycoprotein antibody (MOG) immunoglobulin G (IgG)-associated disease (MOGAD) has clinical and pathophysiological features that are similar to but distinct from those of aquaporin-4 antibody (AQP4-IgG)-positive neuromyelitis optica spectrum disorders (AQP4-NMOSD). MOG-IgG and AQP4-IgG, mostly of the IgG1 subtype, can both activate the complement system. Therefore, we investigated whether the levels of serum complement components, regulators, and activation products differ between MOGAD and AQP4-NMOSD, and if complement analytes can be utilized to differentiate between these diseases. Methods: The sera of patients with MOGAD (from during an attack and remission; N=19 and N=9, respectively) and AQP4-NMOSD (N=35 and N=17), and healthy controls (N=38) were analyzed for C1q-binding circulating immune complex (CIC-C1q), C1 inhibitor (C1-INH), factor H (FH), C3, iC3b, and soluble terminal complement complex (sC5b-9). Results: In attack samples, the levels of C1-INH, FH, and iC3b were higher in the MOGAD group than in the NMOSD group (all, p<0.001), while the level of sC5b-9 was increased only in the NMOSD group. In MOGAD, there were no differences in the concentrations of complement analytes based on disease status. However, within AQP4-NMOSD, remission samples indicated a higher C1-INH level than attack samples (p=0.003). Notably, AQP4-NMOSD patients on medications during attack showed lower levels of iC3b (p<0.001) and higher levels of C3 (p=0.008), C1-INH (p=0.004), and sC5b-9 (p<0.001) compared to those not on medication. Among patients not on medication at the time of attack sampling, serum MOG-IgG cell-based assay (CBA) score had a positive correlation with iC3b and C1-INH levels (rho=0.764 and p=0.010, and rho=0.629 and p=0.049, respectively), and AQP4-IgG CBA score had a positive correlation with C1-INH level (rho=0.836, p=0.003). Conclusions: This study indicates a higher prominence of complement pathway activation and subsequent C3 degradation in MOGAD compared to AQP4-NMOSD. On the other hand, the production of terminal complement complexes (TCC) was found to be more substantial in AQP4-NMOSD than in MOGAD. These findings suggest a strong regulation of the complement system, implying its potential involvement in the pathogenesis of MOGAD through mechanisms that extend beyond TCC formation.
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Neuromielite Óptica , Humanos , Aquaporina 4 , Complemento C1q , Complemento C3b , Proteínas do Sistema Complemento , Imunoglobulina G , Glicoproteína Mielina-OligodendrócitoRESUMO
The effectiveness of almond shell-derived biochar (ASB) in immobilizing soil heavy metals (HMs) and its impact on soil microbial activity and diversity have not been sufficiently studied. Hence, a pot study was carried out to investigate the effectiveness of ASB addition at 2, 4, and 6 % (w/w) on soil biochemical characteristics and the bioavailability of Cd, Cu, Pb, and Zn to tomato (Solanum lycopersicum L.) plants, as compared to the control (contaminated soil without ASB addition). The addition of ASB promoted plant growth (up to two-fold) and restored the damage to the ultrastructure of chloroplast organelles. In addition, ASB mitigated the adverse effects of HMs toxicity by decreasing oxidative damage, regulating the antioxidant system, improving soil physicochemical properties, and enhancing enzymatic activities. At the phylum level, ASB addition enhanced the relative abundance of Actinobacteriota, Acidobacteriota, and Firmicutes while decreasing the relative abundance of Proteobacteria and Bacteroidota. Furthermore, ASB application increased the relative abundance of several fungal taxa (Ascomycota and Mortierellomycota) while reducing the relative abundance of Basidiomycota in the soil. The ASB-induced improvement in soil properties, microbial community, and diversity led to a significant decrease in the DTPA-extractable HMs down to 41.0 %, 51.0 %, 52.0 %, and 35.0 % for Cd, Cu, Pb, and Zn, respectively, as compared to the control. The highest doses of ASB (ASB6) significantly reduced the metals content by 26.0 % for Cd, 78.0 % for Cu, 38.0 % for Pb, and 20.0 % for Zn in the roots, and 72.0 % for Cd, 67.0 % for Cu, 46.0 % for Pb, and 35.0 % for Zn in the shoots, as compared to the control. The structural equation model predicts that soil pH and organic matter are driving factors in reducing the availability and uptake of HMs. ASB could be used as a sustainable trial for remediation of HMs polluted soils and reducing metal content in edible plants.
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Antioxidantes , Carvão Vegetal , Metais Pesados , Microbiota , Prunus dulcis , Microbiologia do Solo , Poluentes do Solo , Solanum lycopersicum , Carvão Vegetal/química , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Microbiota/efeitos dos fármacos , Disponibilidade Biológica , Solo/químicaRESUMO
HYPOTHESIS: Understanding the mechanisms of proton transfer on quartz surfaces in water is critical for a range of processes in geochemical, environmental, and materials sciences. The wide range of surface acidities (>9 pKa units) found on the ubiquitous mineral quartz is caused by the structural variations of surface silanol groups. Molecular scale simulations provide essential tools for elucidating the origin of site-specific surface acidities. SIMULATIONS: We used density-functional tight-binding-based molecular dynamics combined with rare-event metadynamics simulations to probe the mechanisms of deprotonation reactions from ten representative surface silanol groups found on both pristine and defect-rich quartz (101) surfaces with Si vacancies. FINDINGS: The results show that deprotonation is a highly dynamic process where both the surface hydroxyls and bridging oxygen atoms serve as the proton acceptors, in addition to water. Deprotonation of embedded silanols through intrasurface proton transfer exhibited lower pKa values with less H-bond participation and higher energy barriers, suggesting a new mechanism to explain the bimodal acidity observed on quartz surface. Defect sites, recently shown to comprise a significant portion of the quartz (101) surface, diversify the coordination and local H-bonding environments of the surface silanols, changing both the deprotonation pathways and energetics, leading to a wider range of pKa values (2.4 to 11.5) than that observed on pristine quartz surface (10.4 and 12.1).
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The internal crystallinity of calcite is investigated for samples synthesized using two approaches: precipitation from solution and the ammonium carbonate diffusion method. Scanning electron microscopy (SEM) analyses reveal that the calcite products precipitated using both approaches have a well-defined rhombohedron shape, consistent with the euhedral crystal habit of the mineral. The internal structure of these calcite crystals is characterized using Bragg coherent diffraction imaging (BCDI) to determine the 3D electron density and the atomic displacement field. BCDI reconstructions for crystals synthesized using the ammonium carbonate diffusion approach have the expected euhedral shape, with internal strain fields and few internal defects. In contrast, the crystals synthesized by precipitation from solution have very complex external shapes and defective internal structures, presenting null electron density regions and pronounced displacement field distributions. These heterogeneities are interpreted as multiple crystalline domains, created by a nonclassical crystallization mechanism, where smaller nanoparticles coalescence into the final euhedral particles. The combined use of SEM, X-ray diffraction (XRD), and BCDI allows for structurally differentiating calcite crystals grown with different approaches, opening new opportunities to understand how grain boundaries and internal defects alter calcite reactivity.
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BACKGROUND AND AIMS: Endobiliary radiofrequency ablation (RFA) is an emerging endoscopic palliative adjunctive therapy used for the local treatment of unresectable malignant biliary obstruction (MBO). However, irregular ablation ranges caused by insufficient electrode-to-bile duct contact pose a significant obstacle. We investigated the feasibility of a self-expandable stent (SES)-based electrode with a customized RFA generator in the porcine liver and common bile duct (CBD). METHODS: An SES-RFA system with polarity switching was developed to perform endobiliary RFA. The ablation ranges of 20 ablation protocols were evaluated to validate the feasibility of the newly developed RFA system in the porcine liver. Nine of 20 ablation protocols were selected for evaluation in the porcine CBD with cholangiography, endoscopy, and histologic and immunohistochemical analysis. RESULTS: The SES-RFA system with polarity switching was successfully constructed and demonstrated high accuracy and reproducibility. The ablation area was clearly identified between the 2 SESs. The ablation ranges and degree of mucosal damage, including terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling-positive and heat shock protein 70-positive depositions, increased proportionally with ablation protocols in the porcine liver and CBD (all P < .05). Ablation length and depth linearly increased with ablation protocols from 8.74 ± .25 to 31.25 ± .67 mm and 1.61 ± .09 to 11.94 ± .44 mm, respectively. CONCLUSIONS: The SES-RFA system with polarity switching between electrodes provided an even circumferential area of ablation and enhanced ablation depth between the electrodes. This novel endobiliary RFA system is a promising modality for local ablation in patients with unresectable MBO.
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miRNAs are single-stranded ncRNAs that act as regulators of different human body processes. Several miRNAs have been noted to control the human immune and inflammatory response during severe acute respiratory infection syndrome (SARS-CoV-2) infection. Similarly, many miRNAs were upregulated and downregulated during different respiratory virus infections. Here, an attempt has been made to capture the regulatory role of miRNAs in the human immune and inflammatory response during the infection of SARS-CoV-2 and other respiratory viruses. Firstly, the role of miRNAs has been depicted in the human immune and inflammatory response during the infection of SARS-CoV-2. In this direction, several significant points have been discussed about SARS-CoV-2 infection, such as the role of miRNAs in human innate immune response; miRNAs and its regulation of granulocytes; the role of miRNAs in macrophage activation and polarisation; miRNAs and neutrophil extracellular trap formation; miRNA-related inflammatory response; and miRNAs association in adaptive immunity. Secondly, the miRNAs landscape has been depicted during human respiratory virus infections such as human coronavirus, respiratory syncytial virus, influenza virus, rhinovirus, and human metapneumovirus. The article will provide more understanding of the miRNA-controlled mechanism of the immune and inflammatory response during COVID-19, which will help more therapeutics discoveries to fight against the future pandemic.
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COVID-19 , MicroRNAs , Humanos , MicroRNAs/genética , SARS-CoV-2/genética , COVID-19/genética , Vírus Sinciciais Respiratórios , RhinovirusRESUMO
Biliary strictures are characterized by the narrowing of the bile duct lumen, usually caused by surgical biliary injury, cancer, inflammation, and scarring from gallstones. Endoscopic stent placement is a well-established method for the management of biliary strictures. However, maintaining optimal mechanical properties of stents and designing surfaces that can prevent stent-induced tissue hyperplasia and biofilm formation are challenges in the fabrication of biodegradable biliary stents (BBSs) for customized treatment. This study proposes a novel approach to fabricating functionalized polymer BBSs with nanoengineered surfaces using 3D printing. The 3D printed stents, fabricated from bioactive silica poly(ε-carprolactone) (PCL) via a sol-gel method, exhibited tunable mechanical properties suitable for supporting the bile duct while ensuring biocompatibility. Furthermore, a nanoengineered surface layer was successfully created on a sirolimus (SRL)-coated functionalized PCL (fPCL) stent using Zn ion sputtering-based plasma immersion ion implantation (S-PIII) treatment to enhance the performance of the stent. The nanoengineered surface of the SRL-coated fPCL stent effectively reduced bacterial responses and remarkably inhibited fibroblast proliferation and initial burst release of SRL in vitro systems. The physicochemical properties and biological behaviors, including in vitro biocompatibility and in vivo therapeutic efficacy in the rabbit bile duct, of the Zn-SRL@fPCL stent demonstrated its potential as a versatile platform for clinical applications in bile duct tissue engineering.
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The environmental impact of biodegradable polylactic acid microplastics (PLA-MPs) has become a global concern, with documented effects on soil health, nutrient cycling, water retention, and crop growth. This study aimed to assess the repercussions of varying concentrations of PLA-MPs on rice, encompassing aspects such as growth, physiology, and biochemistry. Additionally, the investigation delved into the influence of PLA-MPs on soil bacterial composition and soil enzyme activities. The results illustrated that the highest levels of PLA-MPs (2.5%) impaired the photosynthesis activity of rice plants and hampered plant growth. Plants exposed to the highest concentration of PLA-MPs (2.5%) displayed a significant reduction of 51.3% and 47.7% in their root and shoot dry weights, as well as a reduction of 53% and 49% in chlorophyll a and b contents, respectively. The activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in rice leaves increased by 3.1, 2.8, 3.5, and 5.2 folds, respectively, with the highest level of PLA-MPs (2.5%). Soil enzyme activities, such as CAT, urease, and dehydrogenase (DHA) increased by 19.2%, 10.4%, and 22.5%, respectively, in response to the highest level of PLA-MPs (2.5%) application. In addition, PLA-MPs (2.5%) resulted in a remarkable increase in the relative abundance of soil Proteobacteria, Nitrospirae, and Firmicutes by 60%, 31%, and 98.2%, respectively. These findings highlight the potential adverse effects of PLA-MPs on crops and soils. This study provides valuable insights into soil-rice interactions, environmental risks, and biodegradable plastic regulation, underscoring the need for further research.
Assuntos
Plásticos Biodegradáveis , Oryza , Solo , Plântula , Microplásticos/toxicidade , Plásticos/toxicidade , Clorofila A , PoliésteresRESUMO
Quantitative PCR (qPCR) is the gold standard for detecting nucleic acid sequences specific to the target pathogen. For COVID-19 diagnosis, several molecular assays have been developed. In this study, we present an optimization strategy for the measurement of SARS-CoV-2 RNA via multiplex qPCR and digital PCR (dPCR). Compared to qPCR, both droplet and chip-based dPCR, which are known to be more sensitive and accurate, showed a better resilience to suboptimal assay compositions and cycling conditions following the proposed optimizations. In particular, the formation of heterodimers among assays greatly interfered with qPCR results, but only minimally with dPCR results. In dPCR, existing heterodimers lowered the PCR efficiency, producing a dampened fluorescent signal in positive partitions. This can be corrected by adjusting the PCR cycling conditions, after which dPCR shows the capability of measuring the expected copy number. In addition, we present a process to improve the existing RdRp assay by correcting the primer sequences and matching the melting temperature, ultimately producing highly sensitive and robust assays. The results of this study can reduce the cost and time of SARS-CoV-2 diagnosis while increasing accuracy. Furthermore, our results suggest that dPCR is a reliable method for the accurate measurement of nucleic acid targets.