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BACKGROUND: Patients with type 2 diabetes often face early tubular injury, necessitating effective treatment strategies. This study aimed to evaluate the impact of the SGLT2 inhibitor empagliflozin on early tubular injury biomarkers in type 2 diabetes patients with normoalbuminuria. METHODS: A randomized controlled clinical study comprising 54 patients selected based on specific criteria was conducted. Patients were divided into an intervention group (empagliflozin, n = 27) and a control group (n = 27) and treated for 6 weeks. Tubular injury biomarkers KIM-1 and NGAL were assessed pre- and post-treatment. RESULTS: Both groups demonstrated comparable baseline characteristics. Post-treatment, fasting and postprandial blood glucose levels decreased similarly in both groups. The intervention group exhibited better improvements in total cholesterol, low-density lipoprotein, and blood uric acid levels. Renal function indicators, including UACR and eGFR, showed greater enhancements in the intervention group. Significant reductions in KIM-1 and NGAL were observed in the intervention group. CONCLUSION: Treatment with empagliflozin in type 2 diabetes patients with normoalbuminuria led to a notable decrease in tubular injury biomarkers KIM-1 and NGAL. These findings highlight the potential of SGLT2 inhibitors in early tubular protection, offering a new therapeutic approach.
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Compostos Benzidrílicos , Biomarcadores , Diabetes Mellitus Tipo 2 , Glucosídeos , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/complicações , Compostos Benzidrílicos/uso terapêutico , Glucosídeos/uso terapêutico , Masculino , Feminino , Pessoa de Meia-Idade , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Glicemia , Idoso , Lipocalina-2/sangue , Adulto , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/prevenção & controleRESUMO
Capacitive deionization for selective separation of ions is rarely reported since it relies on the electrostatic attraction of oppositely charged ions with no capability to distinguish ions of different valent states. Using molecular dynamic simulation, a screening process identified a hybrid material known as AC/PTh, which consists of activated carbon with a thin layer of polythiophene (PTh) coating. By utilizing AC/PTh as electrode material implementing the short-circuit cycle (SCC) mode in flow-electrode capacitive deionization (FCDI), selective separation of mono-/divalent ions can be realized via precise control of dynamic adsorption and desorption of mono-/divalent ions at a particular surface. Specifically, AC/PTh shows strong interaction with divalent ions but weak interaction with monovalent ions, the distribution of divalent ions can be enriched in the electric double layer after a couple of adsorption-desorption cycles. At Cu2+/Na+ molar ratio of 1:40, selectivity toward divalent ions can reach up to 110.3 in FCDI SCC mode at 1.0 V. This work presents a promising strategy for separating ions of different valence states in a continuously operated FCDI device.
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The concurrent utilization of an adsorbent and absorbent for carbon dioxide (CO2) adsorption with synergistic effects presents a promising technique for CO2 capture. Here, 1-butyl-3-methylimidazole acetate ([Bmim][Ac]), with a high affinity for CO2, and the molecular sieve SAPO-34 were selected. The impregnation method was used to composite the hybrid samples of [Bmim][Ac]/SAPO-34, and the pore structure and surface property of prepared samples were characterized. The quantity and kinetics of the sorbed CO2 for loaded samples were measured using thermogravimetric analysis. The study revealed that SAPO-34 could retain its pristine structure after [Bmim][Ac] loading. The CO2 uptake of the loaded sample was 1.879 mmol g-1 at 303 K and 1 bar, exhibiting a 20.6% rise compared to that of the pristine SAPO-34 recording 1.558 mmol g-1. The CO2 uptake kinetics of the loaded samples were also accelerated, and the apparent mass transfer resistance for CO2 sorption was significantly reduced by 11.2% compared with that of the pure [Bmim][Ac]. The differential scanning calorimetry method revealed that the loaded sample had a lower CO2 desorption heat than that of the pure [Bmim][Ac], and the CO2 desorption heat of the loaded samples was between 30.6 and 40.8 kJ mol-1. The samples exhibited good cyclic stability. This material displays great potential for CO2 capture applications, facilitating the reduction of greenhouse gas emissions.
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BACKGROUND: Inadequately managed postoperative pain remains a common issue. Examining factors like pain sensitivity, pain catastrophizing, and pain self-efficacy can help improve postoperative pain management. While these factors have been identified as potential predictors of acute postoperative pain, their effects have been inconsistent. Few studies have explored the interactions between these factors. AIM: To investigate the influence of preoperative pain sensitivity, pain catastrophizing, and pain self-efficacy on acute postoperative pain in abdominal surgery patients and to determine the mediating roles of pain catastrophizing and pain self-efficacy in the relationship between pain sensitivity and acute postoperative pain, as per the gate control theory. METHODS: A total of 246 patients were enrolled in this study. General information was collected before surgery, and the Pain Sensitivity Questionnaire (PSQ), Pain Catastrophizing Scale (PCS), and Pain Self-Efficacy Questionnaire (PSEQ) were administered. After surgery, patients' average pain scores over the 24 hours were reported using the Numerical Rating Scale (NRS). Correlation analyses and a structural equation model were used to examine the relationships among these variables. RESULTS: NRS scores over 3 during the 24 hours post-surgery were reported by 21.54% of patients. Postoperative acute pain was found to be associated with pain sensitivity (rs = 0.463, p < .001), pain catastrophizing (rs = 0.328, p < .001), and pain self-efficacy (rs = -0.558, p < .001). A direct effect on postoperative acute pain was exerted by pain sensitivity (effect = 0.250, p = .001), along with indirect effects through: (A) pain catastrophizing (effect = 0.028, p = .001); (B) pain self-efficacy (effect = 0.132, p = .001); and (C) the chain mediation of pain self-efficacy and pain catastrophizing (effect = 0.021, p = .008). CONCLUSIONS: The severity of postoperative acute pain can be predicted by pain self-efficacy and pain catastrophizing, and the connection between moderate pain sensitivity and postoperative acute pain severity is mediated by them. Therefore, intervention programs aimed at boosting pain self-efficacy and reducing pain catastrophizing can enhance postoperative pain outcomes for abdominal surgery patients.
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Dor Aguda , Humanos , Autoeficácia , Catastrofização , Dor Pós-Operatória , Medição da DorRESUMO
Soluble starch synthases (SSs) play important roles in the synthesis of cassava starch. However, the expression characteristics of the cassava SSs genes have not been elucidated. In this study, the MeSSIII-1 gene and its promoter, from SC8 cassava cultivars, were respectively isolated by PCR amplification. MeSSIII-1 protein was localized to the chloroplasts. qRT-PCR analysis revealed that the MeSSIII-1 gene was expressed in almost all tissues tested, and the expression in mature leaves was 18.9 times more than that in tuber roots. MeSSIII-1 expression was induced by methyljasmonate (MeJA), abscisic acid (ABA), and ethylene (ET) hormones in cassava. MeSSIII-1 expression patterns were further confirmed in proMeSSIII-1 transgenic cassava. The promoter deletion analysis showed that the -264 bp to -1 bp MeSSIII-1 promoter has basal activity. The range from -1228 bp to -987 bp and -488 bp to -264 bp significantly enhance promoter activity. The regions from -987 bp to -747 bp and -747 bp to -488 bp have repressive activity. These findings will provide an important reference for research on the potential function and transcriptional regulation mechanisms of the MeSSIII-1 gene and for further in-depth exploration of the regulatory network of its internal functional elements.
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Regulação da Expressão Gênica de Plantas , Manihot , Proteínas de Plantas , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Manihot/genética , Manihot/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Sintase do Amido/genética , Sintase do Amido/metabolismo , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Etilenos/metabolismoRESUMO
Drug discovery involves a crucial step of optimizing molecules with the desired structural groups. In the domain of computer-aided drug discovery, deep learning has emerged as a prominent technique in molecular modeling. Deep generative models, based on deep learning, play a crucial role in generating novel molecules when optimizing molecules. However, many existing molecular generative models have limitations as they solely process input information in a forward way. To overcome this limitation, we propose an improved generative model called BD-CycleGAN, which incorporates BiLSTM (bidirectional long short-term memory) and Mol-CycleGAN (molecular cycle generative adversarial network) to preserve the information of molecular input. To evaluate the proposed model, we assess its performance by analyzing the structural distribution and evaluation matrices of generated molecules in the process of structural transformation. The results demonstrate that the BD-CycleGAN model achieves a higher success rate and exhibits increased diversity in molecular generation. Furthermore, we demonstrate its application in molecular docking, where it successfully increases the docking score for the generated molecules. The proposed BD-CycleGAN architecture harnesses the power of deep learning to facilitate the generation of molecules with desired structural features, thus offering promising advancements in the field of drug discovery processes.
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Fármacos Anti-HIV , Simulação de Acoplamento Molecular , Descoberta de Drogas , Hidrolases , Memória de Longo PrazoRESUMO
BACKGROUND: Patients with schizophrenia (SCH) have deficits in source monitoring (SM), speech-in-noise recognition (SR), and auditory prosody recognition. This study aimed to test the covariation between SM and SR alteration induced by negative prosodies and their association with psychiatric symptoms in SCH. METHODS: Fifty-four SCH patients and 59 healthy controls (HCs) underwent a speech SM task, an SR task, and the assessment of positive and negative syndrome scale (PANSS). We used the multivariate analyses of partial least squares (PLS) regression to explore the associations among SM (external/internal/new attribution error [AE] and response bias [RB]), SR alteration/release induced by four negative-emotion (sad, angry, fear, and disgust) prosodies of target speech, and psychiatric symptoms. RESULTS: In SCH, but not HCs, a profile (linear combination) of SM (especially the external-source RB) was positively associated with a profile of SR reductions (induced especially by the angry prosody). Moreover, two SR reduction profiles (especially in the anger and sadness conditions) were related to two profiles of psychiatric symptoms (negative symptoms, lack of insight, and emotional disturbances). The two PLS components explained 50.4% of the total variances of the release-symptom association. CONCLUSION: Compared to HCs, SCH is more likely to perceive the external-source speech as internal/new source speech. The SM-related SR reduction induced by the angry prosody was mainly associated with negative symptoms. These findings help understand the psychopathology of SCH and may provide a potential direction to improve negative symptoms via minimizing emotional SR reduction in schizophrenia.
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Esquizofrenia , Percepção da Fala , Humanos , Esquizofrenia/complicações , Esquizofrenia/diagnóstico , Fala , Emoções/fisiologia , Ira , Medo , Percepção da Fala/fisiologiaRESUMO
LIGHT is a member of the TNF superfamily and a proinflammatory cytokine involved in liver pathogenesis. Many liver diseases involve activation of Toll-like receptor 3 (TLR3), which is activated by double-stranded RNA (dsRNA). However, the involvement of LIGHT in TLR3 implicated liver diseases is not clear. In this study, we investigated the role of LIGHT in TLR3 involved liver pathogenesis by using a mouse model of TLR3 agonist poly(I:C)-induced hepatitis. We found LIGHT expression at both protein and mRNA level in liver tissues is dramatically increased during the course of poly(I:C)-induced liver injury. This induction depends on NF-κB activation as pretreating the mice with a NF-κB inhibitor abrogates LIGHT upregulation. Importantly, blockade of the LIGHT signaling pathway with the recombinant LIGHT receptor HVEM protein ameliorates liver injury in poly(I:C)-induced hepatitis. Conclusions. These results indicate that LIGHT amplification by NF-κB plays a significant role in TLR3 involved hepatitis and points LIGHT to be a potential drug target for liver disease therapy.
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Hepatite , NF-kappa B , Receptor 3 Toll-Like , Citocinas , Hepatite/genética , Hepatite/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Poli I-C/farmacologia , Transdução de Sinais , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/metabolismo , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo , Animais , Camundongos , Modelos Animais de Doenças , Doença AgudaRESUMO
Objective: Both functional magnetic resonance imaging and renal tubular injury markers have been proved to be able to detect early renal damage in normoalbuminuric diabetic patients. This study mainly explored the functional magnetic resonance imaging parameters and renal tubular injury markers in the early evaluation of type 2 diabetes. Methods: A case observation study was established, and 62 patients with early-stage low-risk type 2 diabetes mellitus with normoalbuminuric (UACR<30 mg/g, eGFR≥60 ml/min/1.73 m2) were included for analysis. Urine kidney damage was determined by ELISA. Kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) assessment of renal tubular injury, and use of intravoxel incoherent motion magnetic resonance Imaging (intravoxel incoherent motion, IVIM) and blood oxygen level dependent magnetic resonance imaging (blood oxygen level dependent, BOLD) to evaluate renal cortex, medulla blood perfusion, water molecule diffusion, oxygenation level and other functional information, using linear correlation to analyze the correlation between functional magnetic resonance imaging parameters and markers of renal tubular injury. Results: The correlation analysis between IVIM parameters and renal tubular injury markers showed that KIM-1 was inversely correlated with the MD value of the renal medulla region parameter (r = -0.24, P = .03), and was closely related to the other IVIM cortex and medulla. There was no correlation between qualitative parameters (P > .05), and no correlation between NGAL and all parameters of IVIM (P > .05). The correlation analysis between BOLD parameters and renal tubular injury markers showed that KIM-1 was positively correlated with renal medulla region parameter MR2* value (r = 0.26, P = .04) and MCR value (r = 0.28, P = .03), respectively. There was also a positive correlation between NGAL and renal medulla region parameter MR2* value (r = 0.24, P = .04). Conclusion: In the early low-risk type 2 diabetic patients with normoalbuminuria, the more obvious the renal medullary water molecule diffusion disorder, the higher the renal tubular injury marker KIM-1, and the more severe renal medullary hypoxia, the renal tubular injury. The higher the markers KIM-1 and NGAL are, it is proved that the hypoxia and water diffusion disorder in the early renal medulla are related to renal tubular damage.
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As a starchy and edible tropical plant, cassava (Manihot esculenta Crantz) has been widely used as an industrial raw material and a dietary source. However, the metabolomic and genetic differences in specific germplasms of cassava storage root were unclear. In this study, two specific germplasms, M. esculenta Crantz cv. sugar cassava GPMS0991L and M. esculenta Crantz cv. pink cassava BRA117315, were used as research materials. Results showed that sugar cassava GPMS0991L was rich in glucose and fructose, whereas pink cassava BRA117315 was rich in starch and sucrose. Metabolomic and transcriptomic analysis indicated that sucrose and starch metabolism had significantly changing metabolites enrichment and the highest degree of differential expression genes, respectively. Sugar transport in storage roots may contribute to the activities of sugar, which will eventually be exported to transporters (SWEETs), such as (MeSWEET1a, MeSWEET2b, MeSWEET4, MeSWEET5, MeSWEET10b, and MeSWEET17c), which transport hexose to plant cells. The expression level of genes involved in starch biosynthesis and metabolism were altered, which may result in starch accumulation. These results provide a theoretical basis for sugar transport and starch accumulation and may be useful in improving the quality of tuberous crops and increasing yield.
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Manihot , Amido , Amido/metabolismo , Manihot/genética , Manihot/metabolismo , Transcriptoma , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Glucose/metabolismo , Sacarose/metabolismoRESUMO
Cancer treatment represents an unmet challenge due to the development of drug resistance and severe side effects of chemotherapy. Artemisinin (ARS)-type compounds exhibit excellent antimalarial effects with few side effects and drug-resistance. ARS and its derivatives were also reported to act against various tumor types in vitro and in vivo, including acute leukemia. Therefore, ARS-type compounds may be exquisitely suitable for repurposing in leukemia treatment. To provide comprehensive clues of ARS and its derivatives for acute leukemia treatment, their molecular mechanisms are discussed in this review. Five monomeric molecules and 72 dimers, trimers and hybrids based on the ARS scaffold have been described against acute leukemia. The modes of action involve anti-angiogenic, anti-metastatic and growth inhibitory effects. These properties make ARS-type compounds as potential candidates for the treatment of acute leukemia. Still, more potent and target-selective ARS-type compounds need to be developed.
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Antimaláricos/uso terapêutico , Antineoplásicos/uso terapêutico , Artemisininas/uso terapêutico , Descoberta de Drogas , Reposicionamento de Medicamentos/métodos , Neoplasias/tratamento farmacológico , Animais , HumanosRESUMO
Methane (CH4 ) is a potent greenhouse gas and the second highest contributor to global warming. CH4 emissions are still growing at an alarmingly high pace. To limit global warming to 1.5 °C, one of the most effective strategies is to reduce rapidly the CH4 emissions by developing large-scale methane removal methods. The purpose of this perspective paper is threefold. (1) To highlight the technology gap dealing with low concentration CH4 (at many emission sources and in the atmosphere). (2) To analyze the challenges and prospects of solar-driven gas phase advanced oxidation processes for CH4 removal. And (3) to propose some ideas, which may help to develop solar-driven gas phase advanced oxidation processes and make them deployable at a climate significant scale.
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Both electrical conductivity and surface wettability are required for the selection of active carbon materials in flow-electrode capacitive deionization, while a trade-off exists between these two properties. In this work, a hybrid material with a thin layer of polyaniline (PANI) coating on activated carbon (AC/PANI) was successfully developed to retain excellent electrical conductivity and acquire good surface wettability. By adjusting the dosage of initiator, AC/PANI composites with different loading fractions of PANI were obtained. The electrochemical testing demonstrated that the AC/PANI composites have higher specific capacitance and lower ion diffusion resistance compared to pure AC, resulting in better desalinization performance. Specifically, with a feed concentration of 1600 mg/L, excellent adsorption capacity and high charge efficiency can be simultaneously achieved at 13.51 mg/g and 92.21%, respectively. Benefiting from the formation of a continuous electrical percolation network and reduced solid/liquid interfacial transport resistance, a 39% enhancement of average salt adsorption rate (from 0.54 to 0.75 µmol/min/cm2) was obtained.
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Membrane separation is considered one of the most promising CO2/CH4 separation technologies currently available because it is a safe, environment-friendly, and economical method. However, the inability of membrane materials to reconcile the trade-off between permeability and permeation selectivity limits their further applications; moreover, the mechanism underlying this process is unclear, which is mainly determined by the performance of gas adsorption and diffusion. Therefore, this paper describes the effect of gas adsorption and diffusion on membrane separation by assessing the fundamental gas-membrane and gas-gas interactions. Combining molecular simulation methods (Monte Carlo and molecular dynamics simulation) and a thermodynamic model called "linearized nonequilibrium thermodynamic transfer model", we investigate the permeability and permeation selectivity for CO2/CH4 in five carbon-based membranes and propose a general method for screening membrane materials. The interaction-dominated mechanism derived in this work provides new insights into membrane separation and facilitates the screening of high-performance membrane materials.
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In this work, the distribution and partition behavior of ionic liquids (ILs) in nanopores with rough surfaces are investigated by a two-dimensional (2D) classical density functional theory model. The model is consistent with the equation of state that combines the perturbed-chain statistical associating fluid theory and the mean spherical approximation theory for bulk fluids. Its performance is verified by comparing the theoretical predictions with the results from molecular simulations. The fast Fourier transform and a hybrid iteration method of Picard iteration and Anderson mixing are used to efficiently obtain the solution of density profile for the sizable 2D system. The molecular parameters for IL-ions are obtained by fitting model predictions to experimental densities of bulk ILs. The model is applied to study the structure and partition of the ILs in nanopores. The results show that the peak of the density profile of counterions near a rough surface is much higher than that near a smooth surface. The adsorption of counterions and removal of co-ions are enhanced by surface roughness. Thus, the nanopore with a rough surface can store more charge. At low absolute surface potential, the partition coefficient for ions on rough surfaces is lower than that on smooth surfaces. At high absolute surface potential, increasing surface roughness leads to an increase in the partition coefficient for counterions and a decrease in the partition coefficient for co-ions.
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The adsorption behaviors of ciprofloxacin (CIP), a fluoroquinolone antibiotic, onto goethite (Gt) in the presence of silver and titanium dioxide nanoparticles (AgNPs and TiO2NPs) were investigated. Results showed that CIP adsorption kinetics in Gt with or without NPs both followed the pseudo-second-order kinetic model. The presence of AgNPs or TiO2NPs inhibited the adsorption of CIP by Gt. The amount of inhibition of CIP sorption due to AgNPs was decreased with an increase of solution pH from 5.0 to 9.0. In contrast, in the presence of TiO2NPs, CIP adsorption by Gt was almost unchanged at pHs of 5.0â¼6.5 but was decreased with an increase of pH from 6.5 to 9.0. The mechanisms of AgNPs and TiO2NPs in inhibiting CIP adsorption by Gt were different, which was attributed to citrate coating of AgNPs resulting in competition with CIP for adsorption sites on Gt, while TiO2NPs could compete with Gt for CIP adsorption. Additionally, CIP was adsorbed by Gt or TiO2NPs through a tridentate complex involving the bidentate inner-sphere coordination of the deprotonated carboxylic group and hydrogen bonding through the adjacent carbonyl group on the quinoline ring. These findings advance our understanding of the environmental behavior and fate of fluoroquinolone antibiotics in the presence of NPs.
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Nanopartículas , Prata , Adsorção , Ciprofloxacina , Concentração de Íons de Hidrogênio , Compostos de Ferro , Minerais , TitânioRESUMO
Piwi-interacting RNAs (piRNAs) defend animal gonads by guiding PIWI-clade Argonaute proteins to silence transposons. The nuclear Piwi/piRNA complexes confer transcriptional repression of transposons, which is accompanied with heterochromatin formation at target loci. On the other hand, piRNA clusters, genomic loci that transcribe piRNA precursors composed of transposon fragments, are often recognized by piRNAs to define their heterochromatic identity. Therefore, Piwi/piRNA complexes must resolve this conundrum of silencing transposons while allowing the expression of piRNA precursors, at least in Drosophila germlines. This review is focused on recent advances how the piRNA pathway deals with this genetic conflict.
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Proteínas Argonautas/metabolismo , Núcleo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Inativação Gênica , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/genética , Transporte Ativo do Núcleo Celular , Animais , Elementos de DNA Transponíveis/genética , Loci Gênicos , Gônadas/metabolismo , Heterocromatina/metabolismo , Transcrição Gênica/genéticaRESUMO
Antibiotic pollution in water has become an increasingly serious problem, posing a potentially huge threat to human health. Ofloxacin (OFL), norfloxacin (NOR), and enoxacin (ENX) are typical broad-spectrum quinolone antibiotics, which are frequently detected in various water environments. An electrochemical sensor is a rapid and effective tool to detect antibiotics in the aquatic environment. The molecular structure of target pollutants is an important factor affecting the detection performance of electrochemical sensors. Based on the electrochemical detection results of antibiotics (OFL, NOR, and ENX), we first used the molecular structure analysis method based on quantum chemistry to accurately identify the electronegativity and the electrocatalytic degree of the oxidizable (and non-oxidizable) functional groups of pollutants. We also clarified the influence mechanism of the molecular structure on the peak current and peak potential. These results can provide theoretical support for rapidly selecting electrodes with a suitable electrochemical window to efficiently detect trace organic pollutants (such as antibiotics) in water based on the molecular structure of the target pollutant.
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Antibacterianos/análise , Quinolonas/análise , Poluentes Químicos da Água/análise , Catálise , Técnicas Eletroquímicas , Enoxacino/análise , Estrutura Molecular , Norfloxacino/análise , Ofloxacino/análise , Oxirredução , ÁguaRESUMO
Enhancing molecular interaction is critical for improving the immobilization and stability of proteins on TiO2 surfaces. In this work, mesoporous TiO2 materials with varied pore geometries were decorated with phenyl phosphoric acid (PPA), followed by a thermal treatment to obtain chemically heterogeneous C-TiO2 samples without changing the geometry and crystalline structure, which can keep the advantages of both carbon and TiO2. The molecular interaction force between the protein and the surfaces was measured using atomic force microscopy by decomposing from the total adhesion forces, showing that the surface chemistry determines the interaction strength and depends on the amount of partial carbon coverage on the TiO2 surface (â¼40-80%). Samples with 58.3% carbon coverage provide the strongest molecular interaction force, consistent with the observation from the detected friction force. Surface-enhanced Raman scattering and electrochemical biosensor measurements for these C-TiO2 materials were further conducted to illustrate their practical implications, implying their promising applications such as in protein detection and biosensing.
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Técnicas Biossensoriais , Nanoestruturas , Microscopia de Força Atômica , TitânioRESUMO
Protein adsorption is of fundamental importance for bioseparation engineering applications. In this work, a series of mesoporous TiO2 with various geometric structures and different aqueous buffer solutions were prepared as platforms to investigate the effects of the surface geometry and ionic strength on the protein adsorptive behavior. The surface geometry of the TiO2 was found to play a dominant role in the protein adsorption capacity when the ionic strength of buffer solutions is very low. With the increase in ionic strength, the effect of the geometric structure on the protein adsorption capacity reduced greatly. The change of ionic strength has the highest significant effect on the mesoporous TiO2 with large pore size compared with that with small pore size. The interaction between the protein and TiO2 measured with atomic force microscopy further demonstrated that the adhesion force induced by the surface geometry reduced with the increase in the ionic strength. These findings were used to guide the detection of the retention behavior of protein by high-performance liquid chromatography, providing a step forward toward understanding the protein adsorption for predicting and controlling the chromatographic separation of proteins.