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Hydrogen has been widely used in industrial and commercial applications as a carbon-free, efficient energy source. Due to the high flammability and explosion risk of hydrogen-air mixtures, it is vital to develop sensors featuring fast-responding and high sensitivity for hydrogen leakage detection. This paper presents a miniaturized electrochemical gas sensor by elaborately establishing a nanocomposite and thin ionic liquid interface for highly sensitive and rapid electrochemical detection of hydrogen, in which a remarkable response time and recovery time of approximately 6 s was achieved at room temperature. A screen-printed carbon electrode was modified with a reduced graphene oxide-carbon nanotube (rGO-CNT) hybrid and platinum-palladium (Pt-Pd) bimetallic nanoparticles to realize high sensitivity. To achieve miniaturization and high stability of the sensor, a thin-film room-temperature ionic liquid (RTIL) was employed as the electrolyte with a significantly decreased response time. The fast-responding hydrogen sensor demonstrates excellent performance with high sensitivity, linearity, and repeatability at concentrations below the lower explosive limit of 4 vol %. The engineered high-performance interface and gas sensor provide a promising and effective strategy for gas sensor design and rapid hazardous gas monitoring.
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Urolithiasis stands as a prevalent ailment within the urinary system, with hyperoxaluria and hypocitraturia being the most frequent manifestations characterized by excessive oxalic acid (OA) and deficient citric acid (CA) levels in urine. Detecting these compounds in urine quantitatively holds paramount importance for early urolithiasis screening. Existing methodologies fall short in achieving simultaneous and on-site identification of OA and CA, posing challenges for accurate urolithiasis screening. Addressing this concern, the study successfully accomplishes the concurrent identification of OA and CA in urine through a combination of dual-spectral analysis and biomimetic peroxidase utilization. Bovine serum albumin and dithiothreitol-modified copper nanoclusters (BSA-DTT-CuNCs) are employed as biomimetic peroxidases, effectively mitigating interference and enabling the simultaneous determination of OA and CA. The quantification range spans from 0 to 12 mm for OA and 0.5 to 2.5 mm for CA, with detection limits of 0.18 and 0.11 mm, respectively. To facilitate swift and on-location urine analysis, a fully automated urine analyzer (FAUA) is introduced that streamlines the process of biomarker pretreatment and identification within urine samples. Validation with real urine samples from urolithiasis patients demonstrates the method's diagnostic precision, highlighting the dual-spectral technique and analyzer's promising role in urolithiasis screening.
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Peroxidase , Urolitíase , Humanos , Ácido Oxálico , Biomimética , Peroxidases , Urolitíase/diagnóstico , Ácido Cítrico , CorantesRESUMO
BACKGROUND: This study aimed to investigate the relationship between serum testosterone levels and the risk of congestive heart failure (CHF) in adult males. Previous research has suggested a potential link between serum testosterone and cardiovascular health, but the findings have been inconclusive. METHODS: This study was cross-sectional, and the data were obtained from the 2011-2016 cycle of the National Health and Nutrition Examination Survey (NHANES), which included a sample of 6,841 male participants. Serum testosterone levels were measured using a standardized assay, and CHF status was assessed through self-reporting. Covariates such as age, ethnicity, lifestyle factors, and health conditions were considered in the analysis. RESULTS: Among the participants, 242 individuals had a documented history of CHF. We observed a linear correlation between serum testosterone levels and CHF occurrence, with higher serum testosterone levels associated with a decreased risk of CHF (Q4 vs. Q1, OR = 0.29, 95% CI: 0.19-0.47, P < 0.001). After adjusting for confounding variables, multivariate analysis revealed that high serum testosterone levels remained significantly associated with a lower risk of CHF (OR: 0.47, 95% CI: 0.27-0.80, P = 0.01). Subgroup analysis indicated a significant association between high serum testosterone levels and reduced CHF risk in individuals over 50 years old. CONCLUSION: Our findings suggest that the serum testosterone level was positively associated with CHF in adult males. This study highlights the potential role of serum testosterone in cardiovascular health, particularly in older individuals. Further research is needed to elucidate the underlying mechanisms and explore the clinical implications of these findings.
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Insuficiência Cardíaca , Adulto , Humanos , Masculino , Idoso , Pessoa de Meia-Idade , Inquéritos Nutricionais , Fatores de Risco , Estudos Transversais , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/complicações , TestosteronaRESUMO
Motivated by recent studies of two-phase lipid vesicles possessing 2D solid domains integrated within a fluid bilayer phase, we study the shape equilibria of closed vesicles possessing a single planar, circular inclusion. While 2D solid elasticity tends to expel Gaussian curvature, topology requires closed vesicles to maintain an average, non-zero Gaussian curvature leading to an elementary mechanism of shape frustration that increases with inclusion size. We study elastic ground states of the Helfrich model of the fluid-planar composite vesicles, analytically and computationally, as a function of planar fraction and reduced volume. Notably, we show that incorporation of a planar inclusion of only a few percent dramatically shifts the ground state shapes of vesicles from predominantly prolate to oblate, and moreover, shifts the optimal surface-to-volume ratio far from spherical shapes. We show that for sufficiently small planar inclusions, the elastic ground states break symmetry via a complex variety of asymmetric oblate, prolate, and triaxial shapes, while inclusion sizes above about 8% drive composite vesicles to adopt axisymmetric oblate shapes. These predictions cast useful light on the emergent shape and mechanical responses of fluid-solid composite vesicles.
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We employ the phospholipid bilayer membranes of giant unilamellar vesicles as a free-standing environment for the growth of membrane-integrated ultrathin phospholipid crystals possessing a variety of shapes with 6-fold symmetry. Crystal growth within vesicle membranes, where more elaborate shapes grow on larger vesicles is dominated by the bending energy of the membrane itself, creating a means to manipulate crystal morphology. Here we demonstrate how cooling rate preconditions the membrane tension before nucleation, in turn regulating nucleation and growth, and directing the morphology of crystals by the time they are large enough to be visualized. The crystals retain their shapes during further growth through the two phase region. Experiments demonstrate this behavior for single crystals growing within the membrane of each vesicle, ultimately comprising up to 13% of the vesicle area and length scales of up to 50 microns. A model for stress evolution, employing only physical property data, reveals how the competition between thermal membrane contraction and water diffusion from tensed vesicles produces a size- and time-dependence of the membrane tension as a result of cooling history. The tension, critical in the contribution of bending energy in the fluid membrane regions, in turn selects for crystal shape for vesicles of a given size. The model reveals unanticipated behaviors including a low steady state tension on small vesicles that allows compact domains to develop, rapid tension development on large vesicles producing flower-shaped domains, and a stress relaxation through water diffusion across the membrane with a time constant scaling as the square of the vesicle radius, consistent with measurable tensions only in the largest vesicles.
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Most nonoxide catalysts based on transition metal elements will inevitably change their primitive phases under anodic oxidation conditions in alkaline media. Establishing a relationship between the bulk phase and surface evolution is imperative to reveal the intrinsic catalytic active sites. In this work, it is demonstrated that the introduction of Fe facilitates the phase transition of orthorhombic CoSe2 into its cubic counterpart and then accelerates the Co-Fe hydroxide layer generation on the surface during electrocatalytic oxygen evolution reaction (OER). As a result, the Fe-doped cubic CoSe2 catalyst exhibits a significantly enhanced activity with a considerable overpotential decrease of 79.9 and 66.9 mV to deliver 10 mA·cm-2 accompanied by a Tafel slope of 48.0 mV·dec-1 toward OER when compared to orthorhombic CoSe2 and Fe-doped orthorhombic CoSe2, respectively. Density functional theory (DFT) calculations reveal that the introduction of Fe on the surface hydroxide layers will tune electron density around Co atoms and raise the d-band center. These findings will provide deep insights into the surface reconstitution of the OER electrocatalysts based on transition metal elements.
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The demand for thermophilic protein has been increasing in protein engineering recently. Many machine-learning methods for identifying thermophilic proteins have emerged during this period. However, most machine learning-based thermophilic protein identification studies have only focused on accuracy. The relationship between the features' meaning and the proteins' physicochemical properties has yet to be studied in depth. In this article, we focused on the relationship between the features and the thermal stability of thermophilic proteins. This method used 2-D general series correlation pseudo amino acid (SC-PseAAC-General) features and realized accuracy of 82.76% using the J48 classifier. In addition, this research found the presence of higher frequencies of glutamic acid in thermophilic proteins, which help thermophilic proteins maintain their thermal stability by forming hydrogen bonds and salt bridges that prevent denaturation at high temperatures.
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Aminoácidos , Aprendizado de Máquina , Ligação de HidrogênioRESUMO
BACKGROUND: Suicide was an important cause of death in prostate cancer. This study intended to investigate trends in suicide mortality among prostate cancer (PCa) survivors from 1975 to 2019 in the United States. METHOD: We identified PCa survivors from the Surveillance, Epidemiology, and End Results (SEER) program from January 1975 to December 2019. Standardized mortality rate (SMR) was calculated d to assess the relative risk of suicide in PCa survivors compared with the general men population. Poisson regression model was performed to test for trend of SMRs. The cumulative mortality rate of suicide was calculated to assess the clinical burden of suicide mortality. RESULTS: 7108 (0.2%) cases were death from suicide cause, and 2,308,923(65.04%%) cases recorded as dying from non-suicidal causes. Overall, a slightly higher suicide mortality rate among PCa survivors was observed compared with general male population (SMR: 1.15, 95%CI: 1.09-1.2). The suicide mortality rate declined significantly relative to the general population by the calendar year of diagnosis, from an SMR of 1.74(95%CI: 1.17-2.51) in 1975-1979 to 0.99(0.89-1.1) in 2015-2019 (Ptrend < 0.001). PCa survivors with aged over 84 years, black and other races, registered in registrations (including Utah, New Mexico, and Hawaii) failed to observe a decrease in suicide mortality (Ptrend > 0.05). The cumulative suicide mortality during 1975-1994 was distinctly higher than in 1995-2019(P < 0.001). CONCLUSION: The trend in suicide mortality declined significantly from 1975 to 2019 among PCa survivors compared with the general male population in the United States. Notably, part of PCa survivors had no improvement in suicide mortality, and additional studies in the future were needed to explore it.
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Sobreviventes de Câncer , Neoplasias da Próstata , Suicídio , Humanos , Masculino , Idoso , Próstata , Sobreviventes , HavaíRESUMO
Glaucoma is a group of diseases characterized by the degeneration of retinal ganglion cells (RGCs) and progressive, irreversible vision loss. High intraocular pressure (IOP) heightens the likelihood of glaucoma and correlates with RGC loss. While the current glaucoma therapy prioritizes lower the IOP; however, RGC, and visual loss may persist even when the IOP is well-controlled. As such, discovering and creating IOP-independent neuroprotective strategies for safeguard RGCs is crucial for glaucoma management. Investigating and clarifying the mechanism behind RGC death to counteract its effects is a promising direction for glaucoma control. Empirical studies of glaucoma reveal the role of multiple regulated cell death (RCD) pathways in RGC death. This review delineates the RCD of RGCs following IOP elevation and optic nerve damage and discusses the substantial benefits of mitigating RCD in RGCs in preserving visual function.
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Glaucoma , Morte Celular Regulada , Animais , Células Ganglionares da Retina/metabolismo , Pressão Intraocular , Glaucoma/terapia , Glaucoma/metabolismo , Neuroproteção , Modelos Animais de DoençasRESUMO
During a survey of thermotolerant fungi in China, three isolates were obtained from soil samples. Phylogenetic analysis of a combined internal transcribed spacer and large subunit dataset showed that these isolates belong to the same species, which form a well-separated lineage distinct from the other genera in Latoruaceae. Morphologically, the isolates are characterized by having globose and smooth conidiogenous cells, verruculose mycelium and cymbiform conidia. Combining the phylogenetic analyses and morphological characteristics, Multiverruca gen. nov. is proposed and introduced to accommodate a single new species, Multiverruca sinensis sp. nov. Detailed descriptions, illustrations and notes are provided for the new genus and species.
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Ascomicetos , Solo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Composição de Bases , Ácidos Graxos/químicaRESUMO
PURPOSE: To investigate prognostic values of prostatic urethra involvement (PUI) and construct a prognostic model that estimates the probability of cancer-specific survival for T1 bladder cancer patients. METHOD AND MATERIALS: We investigated the national Surveillance, Epidemiology, and End Results (SEER) database (2004-2015) to get patients diagnosed with T1 bladder cancer. An external validation cohort was obtained from the First Affiliated Hospital of Nanchang University. The Kaplan-Meier method with the log-rank test was applied to assess cancer-specific survival (CSS) and overall survival (OS). Moreover, the propensity score matching (PSM) and multivariable Cox proportional hazard model were performed. All patients were randomly divided into the development cohort and validation group at the ratio of 7:3. The performance of the model was internally validated by calibration curves and the concordance index (C-index). RESULTS: The PUI group had a lower survival rate of both CSS and overall survival OS before and after PSM when compared to non-involved patients (All P < 0.05). Multivariate analysis revealed a poor prognosis in the PUI group for cancer-specific mortality (CSM) and all-cause mortality (ACM) analyses before and after PSM (All P < 0.05). Seven variables, including age, surgery, radiotherapy, tumour size, PUI, and marital status, were incorporated in the final nomogram. The C-index in the development cohort was 0.715 (0.711-0.719), while it was 0.672 (0.667-0.677) in the validation group. Calibration plots for 3- and 5-year cancer-specific survival showed good concordance in the development and validation cohorts. CONCLUSIONS: PUI was an independent risk factor of ACM and CSM in T1 bladder cancer patients. In addition, a highly discriminative and precise nomogram that predicted the individualized probability of cancer-specific survival for patients with T1 bladder cancer was constructed.
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Neoplasias , Nomogramas , Humanos , Prognóstico , Uretra , Bases de Dados FactuaisRESUMO
BACKGROUND: Renal cell carcinoma (RCC) survival has improved due to recent developments in RCC treatment. Therefore, other co-morbid conditions may have a more critical role. This study aims to explore the common causes of death in patients with RCC to improve the management and survival of RCC. METHOD: We used the Surveillance, Epidemiology, and End Results (SEER) (1992-2018) database to get patients with RCC. We calculated the percentage of total deaths of six kinds of the cause of death (COD) and the cumulative incidence of death for each selected cause over survival time. The joinpoint regression was utilized to present the trend of mortality rate by COD. RESULTS: We enrolled 107,683 cases with RCC. RCC was the leading cause of death in patients with RCC [25376(48.3%)], followed by cardiovascular diseases [9023(17.2%)], other cancers [8003 (15.2%)], other non-cancer diseases [4195 (8%)], non-disease cause [4023 (7.7%)], and respiratory diseases [1934 (3.6%)]. The proportion of patients who died of RCC decreased gradually over survival time, and this value decreased from 69.71% in 1992-1996 to 38.96% in 2012-2018. The non-RCC cause mortality rate showed an increasing trend, whereas a slight decrease was observed in RCC specific mortality rate. The distribution of such conditions varied across different patient populations. CONCLUSION: RCC was still the primary COD of patients with RCC. However, non-RCC cause death was increasingly important among RCC patients in recent two decades. Cardiovascular disease and other cancers were crucial co-morbidities that required significant attention in the management of RCC patients.
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Carcinoma de Células Renais , Neoplasias Renais , Humanos , Estados Unidos/epidemiologia , Carcinoma de Células Renais/epidemiologia , Carcinoma de Células Renais/patologia , Causas de Morte , Incidência , Comorbidade , Programa de SEERRESUMO
BACKGROUND: The aging of China's population has led to an increase in the incidence rate of osteoporosis, which indirectly increases the risk of OVCF in osteoporosis patients. Low back pain is the main symptom of OVCF, and severe patients can further develop kyphosis. Although the conservative treatment of OVCF can effectively control the patient's condition, long-term bed rest will increase the risk of OVCF complications. Minimally invasive surgery is a common solution for OVCF. METHODS: 100 OVCF patients admitted to our hospital from January 2021 to January 2022 are selected for analysis and randomly divided into PVP group and PKP group, 50 cases in each group. The PVP group and the PKP group undergo PVP and PKP operations respectively. The differences in efficacy indicators and adverse reactions are compared, and the multivariate Logistic regression method is used to analyze the influencing factors of postoperative secondary fractures in patients with vertebral compression fractures. RESULTS: Compared with the PVP group, the total effective rate of PKP group is significantly increased, and the VAS, ODI score, kyphotic Cobb Angle, lateral distribution rate of bone cement and bone cement leakage rate are significantly decreased (P < 0.05). Age ≥ 80 years old, female, glucocorticoid use, lateral distribution of bone cement and bone cement leakage are significantly higher in the proportion of secondary fractures and are independent risk factors for postoperative secondary fractures in patients with OVCF. CONCLUSION: PKP surgery has a higher efficacy in the treatment of OVCF patients, which can reduce the incidence of pain, adverse reactions and promote the recovery of kyphotic Cobb Angle. PKP surgery has a higher value in the treatment of OVCF. In addition, the influencing factors of secondary fracture after minimally invasive surgery in OVCF patients include age, gender, glucocorticoid use, bone cement distribution pattern, bone cement leakage, etc.
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Fraturas por Compressão , Cifoplastia , Cifose , Osteoporose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Vertebroplastia , Humanos , Feminino , Idoso de 80 Anos ou mais , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/cirurgia , Fraturas da Coluna Vertebral/complicações , Fraturas por Compressão/diagnóstico por imagem , Fraturas por Compressão/cirurgia , Fraturas por Compressão/complicações , Cifoplastia/métodos , Vertebroplastia/métodos , Cimentos Ósseos/efeitos adversos , Glucocorticoides , Prognóstico , Osteoporose/complicações , Resultado do Tratamento , Cifose/complicações , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Fraturas por Osteoporose/complicações , Estudos RetrospectivosRESUMO
To study the clinical effects of Ω toenail correction in the treatment of paronychia. One hundred thirty-six cases of 130 patients during the period from August 2018 to August 2021 were treated with Ω toenail correction according to clinical stages, the clinical therapeutic effects of which were evaluated in terms of the operation time, the time to resume movement, treatment cycle, 1-y recurrence rate, and visual analogue scale (VAS) scores before and after treatment. The clinical efficacy was analyzed and compared of Ω toenail correction in treating paronychia of different clinical stages. It has been demonstrated that there was no significant difference in operation time, time to resume movement, treatment cycle and recurrence rate among different stages of paronychia, while there existed the significant difference (p < .05) in VAS score of resting-state pain before and after correction which stood at 6.43 ± 0.29 points with the after-treatment VAS scores at 1.10 ± 0.22. There is a statistical difference (p < .05) in VAS score of movement-evoked pain between before and after treatment. The VAS scores of movement-evoked pain stood at 7.55 ± 0.42, which is in contrast with the after-treatment VAS at 1.74 ± 0.93. It has been concluded that Ω toenail correction characterized by easy operation can relieve the pain immediately, which can achieve satisfactory clinical efficacy for treating paronychia of different stages.
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OBJECTIVES: To evaluate the clinical effectiveness of integrated management during the perinatal period for fetuses diagnosed with total anomalous pulmonary venous connection (TAPVC) by prenatal echocardiography. METHODS: Clinical data of 64 cases of TAPVC fetuses diagnosed by prenatal echocardiography and managed with integrated perinatal care in Qingdao Women and Children's Hospital from January 2017 to December 2021 were retrospectively analyzed. Integrated perinatal care included multidisciplinary collaboration among obstetrics, fetal medicine, ultrasound, pediatric cardiology, pediatric anesthesia, and neonatology. RESULTS: Among the 64 TAPVC fetuses, there were 29 cases of supracardiac type, 27 cases of intracardiac type, 2 cases of infracardiac type, and 6 cases of mixed type. Chromosomal analysis was performed in 42 cases, and no obvious abnormalities were found. Among the 64 TAPVC fetuses, 37 were induced labor, and 27 were followed up until term birth. Among the 27 TAPVC cases, 2 cases accepted palliative care, 2 cases were referred to another hospital for treatment and lost to follow-up, while the remaining 23 cases underwent primary repair surgery. One case died within 6 months after the operation due to low cardiac output syndrome, while the other 22 cases were followed up for (2.1±0.3) years with good outcomes (2 cases underwent a second surgery within 1 year after the first operation due to anastomotic stenosis or pulmonary vein stenosis). CONCLUSIONS: TAPVC fetuses can achieve good outcomes with integrated management during the perinatal period.
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Cardiopatias Congênitas , Veias Pulmonares , Síndrome de Cimitarra , Feminino , Humanos , Gravidez , Ecocardiografia , Cardiopatias Congênitas/cirurgia , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/anormalidades , Veias Pulmonares/cirurgia , Estudos Retrospectivos , Síndrome de Cimitarra/diagnóstico por imagem , Síndrome de Cimitarra/cirurgia , Recém-NascidoRESUMO
The past decade has witnessed tremendous progress achieved in taste research, while few studies focus on interactions among taste compounds. Indeed, sweeteners and acidulants are commonly used food additives, and sweet-sour mixtures always provide improved tastes. For example, sensory studies have shown that sourness suppresses sweetness. However, the degree of sweetness suppression by sourness is difficult to evaluate quantitatively and objectively. Therefore, we propose a biohybrid tongue that is constructed by integrating mammalian gustatory epithelium with a microelectrode array chip. The taste quality and intensity information is coded in time-frequency patterns of local field potential. Different response patterns evoked by sweet and sour stimuli are observed, and the response is dose-dependent. Then, interaction effects of sourness against sweetness are quantified. The results indicate that suppression of sweetness by sourness occurs by increasing sourness concentrations. In summary, this study provides a powerful new tool for quantitative evaluation of sweet, sour, and their binary taste interactions that mimic the mammalian taste system.
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Edulcorantes , Paladar , Animais , Mamíferos , Paladar/fisiologia , LínguaRESUMO
Non-invasive deep-tissue three-dimensional optical imaging of live mammals with high spatiotemporal resolution is challenging owing to light scattering. We developed near-infrared II (1,000-1,700 nm) light-sheet microscopy with excitation and emission of up to approximately 1,320 nm and 1,700 nm, respectively, for optical sectioning at a penetration depth of approximately 750 µm through live tissues without invasive surgery and at a depth of approximately 2 mm in glycerol-cleared brain tissues. Near-infrared II light-sheet microscopy in normal and oblique configurations enabled in vivo imaging of live mice through intact tissue, revealing abnormal blood flow and T-cell motion in tumor microcirculation and mapping out programmed-death ligand 1 and programmed cell death protein 1 in tumors with cellular resolution. Three-dimensional imaging through the intact mouse head resolved vascular channels between the skull and brain cortex, and allowed monitoring of recruitment of macrophages and microglia to the traumatic brain injury site.
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Lesões Encefálicas Traumáticas/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Neoplasias Colorretais/diagnóstico por imagem , Microscopia de Fluorescência/métodos , Imagem Óptica/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Encéfalo/irrigação sanguínea , Lesões Encefálicas Traumáticas/patologia , Neoplasias Colorretais/irrigação sanguínea , Neoplasias Colorretais/patologia , Feminino , Corantes Fluorescentes , Humanos , Imageamento Tridimensional , Raios Infravermelhos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Several concepts for platinum-based catalysts for the oxygen reduction reaction (ORR) are presented that exceed the US Department of Energy targets for Pt-related ORR mass activity. Most concepts achieve their high ORR activity by increasing the Pt specific activity at the expense of a lower electrochemically active surface area (ECSA). In the potential region controlled by kinetics, such a lower ECSA is counterbalanced by the high specific activity. At higher overpotentials, however, which are often applied in real systems, a low ECSA leads to limitations in the reaction rate not by kinetics, but by mass transport. Here we report on self-supported platinum-cobalt oxide networks that combine a high specific activity with a high ECSA. The high ECSA is achieved by a platinum-cobalt oxide bone nanostructure that exhibits unprecedentedly high mass activity for self-supported ORR catalysts. This concept promises a stable fuel-cell operation at high temperature, high current density and low humidification.
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Keratinophyton is a genus of well-known keratinophilic fungi found in various terrestrial habitats. During a survey of keratinolytic fungi in China, a total of 12 isolates of Keratinophyton species, representing eight taxa, were obtained from the soil. Two of these isolates were described as new species based on their morphological characteristics and molecular analyses of the internal transcribed spacer region and the rRNA gene of the nuclear large subunit. Descriptions and illustrations of these two novel species, which are named Keratinophyton chongqingense sp. nov. and Keratinophyton sichuanense sp. nov., are provided herein.
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Microbiologia do Solo , Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fungos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
PbTx-2 and okadaic acid (OA) are two typical marine toxins that are highly toxic and harmful to human health. The approach based on citrate-capped gold nanoparticles (Cit-AuNPs) and specific aptamers to construct label-free colorimetric sensors is a widely used method for marine toxin detection. However, the potential interactions between Cit-AuNPs and target molecules have always been ignored, which may result in wrong analytical results due to shortcomings in the Cit-AuNPs. To overcome these shortfalls, in this work, AuNPs were synthesized using tyrosine as a reducing and capping agent, and a robust colorimetric aptasensor based on tyrosine-capped AuNPs (Tyr-AuNPs) was constructed for the label-free detection of marine toxins. Tyr-AuNPs presented better stability compared to Cit-AuNPs due to the stronger binding of amine groups on tyrosine to AuNPs through the Au-N bond. Interactions between Tyr-AuNPs and PbTx-2 were analyzed through UV-vis and isothermal titration calorimetry methods and the results validated the robustness of the Tyr-AuNPs. Colorimetric aptasensors were established for PbTx-2 and OA detection with a linear range of 0.05-4 ppm and limits of detection of 2.25 ppb and 5.19 ppb, respectively. These results demonstrate that the developed colorimetric aptasensor can be a robust and promising method for marine toxin detection.