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1.
Mol Microbiol ; 120(5): 684-701, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37718557

RESUMEN

Syphilis is a persistent sexually transmitted disease caused by infiltration of the elusive pathogen Treponema pallidum. Despite the prevalence of human polymorphonuclear neutrophils (hPMNs) within cutaneous lesions, which are characteristic of incipient syphilis, their role in T. pallidum infection remains unclear. Tp92 is the only T. pallidum helical outer membrane protein that exhibits structural features similar to those of outer membrane proteins in other gram-negative bacteria. However, the functional mechanism of this protein in immune cells remains unclear. Neutrophils are short-lived cells that undergo innate apoptosis in response to external stimuli that typically influence this process. In this study, we determined that Tp92 impedes the activation of procaspase-3 via the ERK MAPK, PI3K/Akt, and NF-κB signaling pathways, consequently suppressing caspase-3 activity within hPMNs, and thereby preventing hPMNs apoptosis. Furthermore, Tp92 could also modulate hPMNs apoptosis by enhancing the expression of the anti-apoptotic protein Mcl-1, stimulating IL-8 secretion, and preserving the mitochondrial membrane potential. These findings provide valuable insights into the molecular mechanisms underlying T. pallidum infection and suggest potential therapeutic targets for syphilis treatment.


Asunto(s)
FN-kappa B , Sífilis , Humanos , FN-kappa B/metabolismo , Treponema pallidum/genética , Treponema pallidum/metabolismo , Sífilis/metabolismo , Sífilis/microbiología , Sífilis/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas de la Membrana/metabolismo , Neutrófilos , Apoptosis
2.
J Eur Acad Dermatol Venereol ; 38(8): 1478-1490, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38376088

RESUMEN

Treponema pallidum is the causative factor of syphilis, a sexually transmitted disease (STD) characterized by perivascular infiltration of inflammatory cells, vascular leakage, swelling and proliferation of endothelial cells (ECs). The endothelium lining blood and lymphatic vessels is a key barrier separating body fluids from host tissues and is a major target of T. pallidum. In this review, we focus on how T. pallidum establish intimate interactions with ECs, triggering endothelial dysfunction such as endothelial inflammation, abnormal repairment and damage of ECs. In addition, we summarize that migration and invasion of T. pallidum across vascular ECs may occur through two pathways. These two mechanisms of transendothelial migration are paracellular and cholesterol-dependent, respectively. Herein, clarifying the relationship between T. pallidum and endothelial dysfunction is of great significance to provide novel strategies for diagnosis and prevention of syphilis, and has a great potential prospect of clinical application.


Asunto(s)
Endotelio Vascular , Sífilis , Treponema pallidum , Humanos , Sífilis/microbiología , Endotelio Vascular/fisiopatología , Endotelio Vascular/patología , Células Endoteliales/patología , Células Endoteliales/microbiología
3.
J Transl Med ; 21(1): 917, 2023 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-38105236

RESUMEN

Syphilis, a sexually transmitted disease (STD) caused by Treponema pallidum (T. pallidum), has had a worldwide resurgence in recent years and remains a public health threat. As such, there has been a great deal of research into clinical strategies for the disease, including diagnostic biomarkers and possible strategies for treatment and prevention. Although serological testing remains the predominant laboratory diagnostic method for syphilis, it is worth noting that investigations pertaining to the DNA of T. pallidum, non-coding RNAs (ncRNAs), chemokines, and metabolites in peripheral blood, cerebrospinal fluid, and other bodily fluids have the potential to offer novel perspectives on the diagnosis of syphilis. In addition, the global spread of antibiotic resistance, such as macrolides and tetracyclines, has posed significant challenges for the treatment of syphilis. Fortunately, there is still no evidence of penicillin resistance. Hence, penicillin is the recommended course of treatment for syphilis, whereas doxycycline, tetracycline, ceftriaxone, and amoxicillin are viable alternative options. In recent years, efforts to discover a vaccine for syphilis have been reignited with better knowledge of the repertoire of T. pallidum outer membrane proteins (OMPs), which are the most probable syphilis vaccine candidates. However, research on therapeutic interventions and vaccine development for human subjects is limited due to practical and ethical considerations. Thus, the preclinical model is ideal for conducting research, and it plays an important role in clinical transformation. Different preclinical models have recently emerged, such as in vitro culture and mouse models, which will lay a solid foundation for clinical treatment and prevention of syphilis. This review aims to provide a comprehensive summary of the most recent syphilis tactics, including detection, drug resistance treatments, vaccine development, and preclinical models in clinical practice.


Asunto(s)
Sífilis , Vacunas , Animales , Ratones , Humanos , Sífilis/tratamiento farmacológico , Treponema pallidum , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Doxiciclina/uso terapéutico , Vacunas/uso terapéutico
4.
Risk Anal ; 43(6): 1097-1114, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-35853833

RESUMEN

Foodborne disease caused by nontyphoidal Salmonella (NTS) is one of the most important food safety issues worldwide. The objectives of this study were to carry out microbial monitoring on the prevalence of NTS in commercial ground pork, investigate consumption patterns, and conduct a quantitative microbiological risk assessment (QMRA) that considers cross-contamination to determine the risk caused by consuming ground pork and ready-to-eat food contaminated during food handling in the kitchen in Chengdu, China. The food pathway of ground pork was simplified and assumed to be several units according to the actual situation and our survey data, which were collected from our research or references and substituted into the QMRA model for simulation. The results showed that the prevalence of NTS in ground pork purchased in Chengdu was 69.64% (95% confidence interval [CI], 60.2-78.0), with a mean contamination level of -0.164 log CFU/g. After general cooking, NTS in ground pork could be eliminated (contamination level of zero). The estimated probability of causing salmonellosis per day was 9.43E-06 (95% CI: 8.82E-06-1.00E-05), while the estimated salmonellosis cases per million people per year were 3442 (95% CI: 3218-3666). According to the sensitivity analysis, the occurrence of cross-contamination was the most important factor affecting the probability of salmonellosis. To reduce the risk of salmonellosis caused by NTS through ground pork consumption, reasonable hygiene prevention and control measures should be adopted during food preparation to reduce cross-contamination. This study provides valuable information for household cooking and food safety management in China.


Asunto(s)
Carne de Cerdo , Carne Roja , Intoxicación Alimentaria por Salmonella , Infecciones por Salmonella , Animales , Humanos , Porcinos , Carne Roja/microbiología , Carne de Cerdo/análisis , Microbiología de Alimentos , Salmonella , Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/prevención & control , Infecciones por Salmonella/epidemiología , Medición de Riesgo/métodos , Manipulación de Alimentos/métodos , Contaminación de Alimentos/análisis
5.
Catheter Cardiovasc Interv ; 99(3): 763-771, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-33590679

RESUMEN

BACKGROUND: Based on coronary angiography and mean aortic pressure, a specially designed computational flow dynamics (CFD) method is proposed to determine contrast fractional flow reserve (cFFR) without using invasive pressure wire. This substudy assessed diagnostic performance of coronary angiography-derived cFFR in catheterization laboratory, based on a previous multicenter trial for online assessment of coronary angiography-derived FFR (caFFR). METHODS: Patients with diagnosis of stable angina pectoris or unstable angina pectoris were enrolled in six centers. Wire-based FFR was measured in coronary arteries with 30-90% diameter stenosis. Offline angiography-derived cFFR was computed in blinded fashion against the wire-based FFR and caFFR at an independent core laboratory. RESULTS: A total of 330 patients were enrolled to fulfill inclusion/exclusion criteria from June 26 to December 18, 2018. Offline angiography-derived cFFR and wire-based FFR results were compared in 328 interrogated vessels. The statistical analysis showed the highest diagnostic accuracy of 89.0 and 86.6% for angiography-derived cFFR with a cutoff value of 0.94 and 0.93 against the wire-based FFR with a cutoff value of 0.80 and 0.75, respectively. The corresponding sensitivity and specificity were 92.2 and 87.3% for the cutoff value of 0.94 and 80.0 and 88.4% for the cutoff value of 0.93, which are similar to those against the caFFR. The receiver-operating curve has area under the curve of 0.951 and 0.972 for the wire-based FFR with the cutoff value of 0.80 and 0.75, respectively. CONCLUSIONS: Coronary angiography-derived cFFR showed higher accuracy, sensitivity, and specificity against wired-based FFR and caFFR. Hence, angiography-derived cFFR could enhance the hemodynamic assessment of coronary lesions.


Asunto(s)
Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Estenosis Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Humanos , Valor Predictivo de las Pruebas , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
6.
Nanotechnology ; 33(50)2022 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-36049467

RESUMEN

Ultra-high frequency (UHF) radio frequency identification (RFID) tags need to be attached or embedded to objects in various environments to achieve non-contact automatic identification. Graphene shows unique electrical and optical properties, which makes it become a promising material for radio frequency devices. In this paper, the transparent UHF RFID tags were fabricated based on graphene films with different number of stacked layers prepared by chemical vapor deposition (CVD). Through structural design, parameter optimization and experimental measurements, the reading distance of the transparent RFID tags was tested and compared. As the graphene film stacked layers increased, the reading distance of graphene-based RFID tags was farther. The UHF RFID tag based on the CVD-grown graphene with the light transmittance of 88% reached the maximum reading distance of 2.78 m in the frequency range of 860-960 MHz. In addition, the reading distance of graphene-based RFID tags at different bending angles and cycles was measured. The results reveal transparent graphene-based RFID tags have good flexibility and stability and can be used in flexible transparent devices.

7.
Mol Biol Rep ; 49(11): 10761-10773, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35810239

RESUMEN

Autophagy is a lysosomal degradation pathway that depends on various evolutionarily conserved autophagy-related genes (ATGs). Dysregulation of autophagy plays an important role in the occurrence and development of cancer. Chemotherapy, targeted therapy, radiotherapy, and immunotherapy are important treatment options for cancer, which can significantly improve the survival rate of cancer patients. However, the occurrence of therapy resistance results in therapeutic failure and poor prognosis of cancer. Accumulating studies have found that long non-coding RNAs (lncRNAs) are well known as crucial regulators to control autophagy through regulating ATGs and autophagy-associated signaling pathways, including the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, ultimately mediating chemoresistance and radioresistance. Taken together, this review systematically summarizes and elucidates the pivotal role of lncRNAs in cancer chemoresistance and radioresistance via regulating autophagy. Understanding the specific mechanism of which may provide autophagy-related therapeutic targets for cancer in the future.


Asunto(s)
Neoplasias , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Autofagia/genética , Neoplasias/tratamiento farmacológico , Neoplasias/genética
8.
Opt Express ; 29(22): 36389-36399, 2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34809050

RESUMEN

Nonlinear optical property of atomically thin materials suspended in liquid has attracted a lot of attention recently due to the rapid development of liquid exfoliation methods. Here we report laser-induced dynamic orientational alignment and nonlinear-like optical response of the suspensions as a result of their intrinsic anisotropic properties and thermal convection of solvents. Graphene and graphene oxide suspensions are used as examples, and the transition to ordered states from initial optically isotropic suspensions is revealed by birefringence imaging. Computational fluid dynamics is performed to simulate the velocity evolution of convection flow and understand alignment-induced birefringence patterns. The optical transmission of these suspensions exhibits nonlinear-like saturable or reverse saturable absorptions in Z-scan measurements with both nanosecond and continuous-wave lasers. Our findings not only demonstrate a non-contact controlling of macroscopic orientation and collective optical properties of nanomaterial suspensions by laser but also pave the way for further explorations of optical properties and novel device applications of low-dimensional nanomaterials.

9.
Cancer Cell Int ; 21(1): 653, 2021 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-34876130

RESUMEN

MYB is often overexpressed in malignant tumors and plays a carcinogenic role in the initiation and development of cancer. Deletion of the MYB regulatory C-terminal domain may be a driving mutation leading to tumorigenesis, therefore, different tumor mechanisms produce similar MYB proteins. As MYB is a transcription factor, priority has been given to identifying the genes that it regulates. All previous attention has been focused on protein-coding genes. However, an increasing number of studies have suggested that MYB can affect the complexity of cancer progression by regulating tumor-associated noncoding RNAs (ncRNAs), such as microRNAs, long-non-coding RNAs and circular RNAs. ncRNAs can regulate the expression of numerous downstream genes at the transcription, RNA processing and translation levels, thereby having various biological functions. Additionally, ncRNAs play important roles in regulating MYB expression. This review focuses on the intricate crosstalk between oncogenic MYB and ncRNAs, which play a pivotal role in tumorigenesis, including proliferation, apoptosis, angiogenesis, metastasis, senescence and drug resistance. In addition, we discuss therapeutic strategies for crosstalk between MYB and ncRNAs to prevent the occurrence and development of cancer.

10.
Nanotechnology ; 32(47)2021 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-34375954

RESUMEN

The transfer process of chemical vapor deposition graphene film leads to unavoidable crack, wrinkles, doping, and contamination, which limits its function to establish stable and high-performance devices. It raises a growing interest to fabricate high-quality graphene on the target substrate directly. Here, bi-layer graphene (BLG) film can be grown on sapphire substrate by a Cu sacrificial layer using atmospheric-pressure chemical vapor deposition. The as-obtained BLG at the interface between sapphire and Cu layer is free of wrinkles, and the corresponding surface roughness Ra is as low as 0.66 nm. The square resistance of the graphene is 898.1 ohm sq-1, which is the lowest among the records of graphene film directly grown on nonmetal substrates.

11.
Pak J Pharm Sci ; 34(3(Special)): 1249-1254, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34602396

RESUMEN

This study attempted to investigate the effect of intravenous anesthesia with dexmedetomidine and propofol combined with seaweed polysaccharides on painless induced abortion. A total of 82 pregnant females were divided into study group and reference group. The subjects in the study group took seaweed polysaccharides orally before surgery and received intravenous anesthesia with dexmedetomidine and propofol, while the subjects in the reference group received intravenous anesthesia with sufentanil combined with propofol. The onset time of anesthesia in the reference group was significantly shorter than that in the study group (P<0.001) and both recovery time and the dosage of propofol in the study group were significantly lower than those in the reference group (P<0.001). The values of MAP and HR at T3 and T4, clinical analgesia effective rate, ramsay sedation scores and incidence of adverse reactions of the subjects in study group was significantly better than those indexes of the subjects in reference group (P<0.05). The intravenous anesthesia with dexmedetomidine and propofol combined with seaweed polysaccharides is a promising strategy for painless induced abortion, which is worthy of application and popularization in clinical practice.


Asunto(s)
Aborto Inducido/métodos , Anestésicos Intravenosos/uso terapéutico , Carragenina/uso terapéutico , Sedación Profunda/métodos , Dexmedetomidina/uso terapéutico , Dolor Asociado a Procedimientos Médicos/tratamiento farmacológico , Propofol/uso terapéutico , Adulto , Presión Arterial , Mareo , Femenino , Frecuencia Cardíaca , Hemodinámica , Humanos , Complicaciones Posoperatorias/epidemiología , Náusea y Vómito Posoperatorios/epidemiología , Embarazo , Algas Marinas , Sufentanilo/uso terapéutico , Adulto Joven
12.
Blood Cells Mol Dis ; 85: 102477, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32711219

RESUMEN

Chronic myeloid leukemia (CML) is a kind of myeloproliferative disorder caused by a constitutively active BCR-ABL tyrosine kinase. Tyrosine kinase inhibitors (TKIs), imatinib and its derivatives, have achieved great progress in the treatment of CML. However, many CML patients do not respond to TKIs alone. p19INK4d, a cyclin-dependent kinase inhibitor, plays important roles in proliferation, DNA damage repair, apoptosis and cell differentiation, but its role in CML is unknown. Herein, we found that the expression of p19INK4d in CML patients was significantly lower than that in healthy controls. p19INK4d overexpression inhibits cell proliferation through cell cycle arrest, and cooperates with imatinib to inhibit CML more effectively in vitro and in vivo. Mechanistically, p19INK4d decreased the expression of BCR-ABL and its downstream molecules p-Mek1/2, moreover, the expression of Gli-1, c-myc, MUC1, Shh and TC48 also reduced significantly. Collectively, p19INK4d inhibits proliferation and enhances imatinib efficacy in the treatment of CML. These findings maybe have implications for developing potential targets to increase imatinib sensitivity for CML.


Asunto(s)
Antineoplásicos/uso terapéutico , Inhibidor p19 de las Quinasas Dependientes de la Ciclina/genética , Proteínas de Fusión bcr-abl/genética , Regulación Leucémica de la Expresión Génica , Mesilato de Imatinib/uso terapéutico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Animales , Antineoplásicos/farmacología , Proliferación Celular/efectos de los fármacos , Inhibidor p19 de las Quinasas Dependientes de la Ciclina/metabolismo , Proteínas de Fusión bcr-abl/metabolismo , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Mesilato de Imatinib/farmacología , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Ratones Desnudos , Transducción de Señal/efectos de los fármacos
13.
J Appl Toxicol ; 39(1): 87-100, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30027633

RESUMEN

4-Nonylphenol (NP) is a persistent estrogen-active compound. Human exposure to NP is primarily through water and food. Although risk assessments of NP have been conducted by the European Union and a few other countries, only the Danish Veterinary and Food Administration, in 2000, proposed a tolerable daily intake of 0.005 mg kg-1 body weight (bw) day-1 . New data have been accumulated since then, prompting an update on the risk assessment of NP. A weight of evidence approach is recommended for use in scientific assessments by several agencies, e.g., European Food Safety Authority, etc. Based on the results of a weight of evidence approach, two methods were used to derive the health-based guidance value (HBGV) for NP in this study, namely a no observed adverse effects level/lowest observable adverse effect level method, and a benchmark dose method. Considering the considerable uncertainty of benchmark dose model fitting of the available data, a tolerable daily intake value of 0.025 mg kg-1 bw day-1 was derived as a provisional HBGV for NP based on the lowest observable adverse effect level value of 15 mg kg-1 bw day-1 of the renal toxicity in rats, together with the uncertainty factor of 600. However, the HBGV of NP still needs further investigation.


Asunto(s)
Exposición Dietética/normas , Contaminación de Alimentos/análisis , Guías como Asunto , Nivel sin Efectos Adversos Observados , Fenoles/análisis , Fenoles/normas , Animales , Humanos , Modelos Animales , Ratas , Medición de Riesgo
14.
Environ Health Prev Med ; 24(1): 32, 2019 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-31084616

RESUMEN

BACKGROUND: Traditional toxicological studies focus on individual compounds. However, this single-compound approach neglects the fact that the mixture exposed to human may act additively or synergistically to induce greater toxicity than the single compounds exposure due to their similarities in the mode of action and targets. Mixture effects can occur even when all mixture components are present at levels that individually do not produce observable effects. So the individual chemical effect thresholds do not necessarily protect against combination effects, an understanding of the rules governing the interactive effects in mixtures is needed. The aim of the study was to test and analyze the individual and combined estrogenic effects of a mixture of three endocrine disrupting chemicals (EDCs), bisphenol A (BPA), nonylphenol (NP) and diethylstilbestrol (DES) in immature rats with mathematical models. METHOD: In the present study, the data of individual estrogenic effects of BPA, NP and DES were obtained in uterotrophic bioassay respectively, the reference points for BPA, NP and DES were derived from the dose-response ralationship by using the traditional no observed adverse effect (NOAEL) or lowest observed adverse effect level (LOAEL) methods, and the benchmark dose (BMD) method. Then LOAEL values and the benchmark dose lower confidence limit (BMDL10) of single EDCs as the dose design basis for the study of the combined action pattern. Mixed prediction models, the 3 × 2 factorial design model and the concentration addition (CA) model, were employed to analyze the combined estrogenic effect of the three EDCs. RESULTS: From the dose-response relationship of estrogenic effects of BPA, NP and DES in the model of the prepuberty rats, the BMDL10(NOAEL) of the estrogenic effects of BPA, NP and DES were 90(120) mg/kg body weight, 6 mg/kg body weight and 0.10(0.25) µg/kg body weight, and the LOAEL of the the estrogenic effects of three EDCs were 240 mg/kg body weight, 15 mg/kg body weight and 0.50 µg/kg body weight, respectively. At BMDL10 doses based on the CA concept and the factorial analysis, the mode of combined effects of the three EDCs were dose addition. Mixtures in LOAEL doses, NP and DES combined effects on rat uterine/body weight ratio indicates antagonistic based on the CA concept but additive based on the factorial analysis. Combined effects of other mixtures are all additive by using the two models. CONCLUSION: Our results showed that CA model provide more accurate results than the factorial analysis, the mode of combined effects of the three EDCs were dose addition, except mixtures in LOAEL doses, NP and DES combined effects indicates antagonistic effects based on the CA model but additive based on the factorial analysis. In particular, BPA and NP produced combination effects that are larger than the effect of each mixture component applied separately at BMDL doses, which show that additivity is important in the assessment of chemicals with estrogenic effects. The use of BMDL as point of departure in risk assessment may lead to underestimation of risk, and a more balanced approach should be considered in risk assessment.


Asunto(s)
Disruptores Endocrinos/toxicidad , Estrógenos/toxicidad , Modelos Teóricos , Animales , Compuestos de Bencidrilo/toxicidad , Dietilestilbestrol/toxicidad , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Fenoles/toxicidad , Ratas , Ratas Sprague-Dawley , Medición de Riesgo
15.
Angew Chem Int Ed Engl ; 58(43): 15206-15226, 2019 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-30785665

RESUMEN

Hybrid organic-inorganic materials have been considered as a new candidate in the field of thermoelectric materials since the last decade owing to their great potential to enhance the thermoelectric performance by utilizing the low thermal conductivity of organic materials and the high Seebeck coefficient, and high electrical conductivity of inorganic materials. Herein, we provide an overview of interfacial engineering in the synthesis of various organic-inorganic thermoelectric hybrid materials, along with the dimensional design for tuning their thermoelectric properties. Interfacial effects are examined in terms of nanostructures, physical properties, and chemical doping between the inorganic and organic components. Several key factors which dictate the thermoelectric efficiency and performance of various electronic devices are also discussed, such as the thermal conductivity, electric transportation, electronic band structures, and band convergence of the hybrid materials.

16.
Chemistry ; 24(55): 14816-14823, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30063103

RESUMEN

Flexible rechargeable zinc-air batteries are considered as one of the most promising power supplies for the emerging flexible and wearable electronic devices. However, the development of flexible zinc-air batteries is stagnant due to the lack of efficient bifunctional catalysts with high oxygen catalytic activity and flexible solid-state electrolytes with high mechanical stability and ionic conductivity. In this work, Co3 O4 /Ag@NrGO composite was synthesized by a facile one-pot method, and the catalyst shows remarkable oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) bifunctional catalytic activity and good long-term stability. In particular, the OER overpotential of Co3 O4 /Ag@NrGO reaches 437 mV, outperforming that of the commercial IrO2 catalyst. This can be attributed to the combined effects of Co3 O4 , Ag, and N-rGO. Furthermore, PAA (polyacrylic acid) and PVA (polyvinyl alcohol) based gel-electrolytes have been developed as flexible solid-state electrolytes for zinc-air batteries. The results show that PAA-based electrolyte is more favorable to the flexible zinc-air battery with a high power density due to its relatively high ionic conductivity. The maximum power density of flexible zinc-air batteries with Co3 O4 /Ag@NrGO catalyst and PAA-based electrolyte can reach 108 mW cm-2 , which is almost the highest value reached in recent reports. This work will provide valuable guidance for the development of flexible rechargeable zinc-air batteries with high power density and stability.

17.
Regul Toxicol Pharmacol ; 97: 120-126, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29928935

RESUMEN

Benchmark dose (BMD) analysis is generally recognized superior to generate a point of departure (PoD) to conduct risk assessment on environmental toxicants, comparing with the traditionally employed no observed adverse effect level (NOAEL) or lowest observed adverse effect level (LOAEL) methods. However, only a few studies compared the two on producing PoD of thyroid toxicity caused by environmental chemicals. Here, we presented BMD analyses on several thyroid toxicity endpoints caused by a model chemical - propylthiouracil (PTU). Adult female rats underwent ovariectomy were randomly assigned into groups receiving different doses of PTU (0, 0.1, 0.5, 1.0, and 5.0 mg/kg bw) through gavage for 8 days. Results show that PTU induces significant dose-dependent changes of serum total thyroxine (tT4), total triiodothyronine (tT3), thyroid stimulating hormones, liver type I 5'-deiodinonase (5'-DI) and malic enzyme (ME) activity with profound histopathological exacerbation. BMD and BMDL results (0.03 and 0.01 mg/kg bw respectively) from Hill model of liver 5'-DI activity were accepted based on selection criteria in the benchmark dose analysis. In summary, BMD analysis results in much lower PoD (0.01 mg/kg bw) than LOAEL (0.1 mg/kg bw) in PTU induced thyroid toxicity.


Asunto(s)
Benchmarking , Ovariectomía , Propiltiouracilo/toxicidad , Glándula Tiroides/efectos de los fármacos , Glándula Tiroides/cirugía , Administración Oral , Animales , Femenino , Propiltiouracilo/administración & dosificación , Ratas , Ratas Sprague-Dawley , Glándula Tiroides/patología , Hormonas Tiroideas/sangre
18.
Environ Health Prev Med ; 23(1): 7, 2018 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-29444637

RESUMEN

BACKGROUND: China has the world's largest tea plantation area in the world. To sustain high yields of the tea, multiple pesticides are used on tea crops to control pests. Organophosphorus (OP) pesticides are among the most widely used types of agricultural pesticides in China. As tea is a significant potential source of exposure to pesticide residues, the public concern has increased in relation to pesticide residues found in tea in China. The aim of the study was to estimate cumulative dietary exposure to OP residues from tea infusion for Chinese tea consumers to determine whether exposure to OP residues from tea infusion is a cause of health concern for tea consumers in China. METHODS: OP residue data were obtained from the China National Monitoring Program on Food Safety (2013-2014), encompassing 1687 tea samples from 12 provinces. Tea consumption data were obtained from the China National Nutrient and Health Survey (2002), comprising 506 tea consumers aged 15-82 years. The transfer rates of residues from tea leaves into tea infusions were obtained from the literature. The relative potency factor (RPF) approach was used to estimate acute cumulative exposure to 20 OP residues from tea infusion using methamidophos as the index compound. Dietary exposure was calculated in a probabilistic way. RESULTS: For tea consumers, the mean and the 99.9th percentile (P99.9) of cumulative dietary exposure to OP residues from tea infusion equalled 0.08 and 1.08 µg/kg bw/d. When compared with the acute reference dose (ARfD), 10 µg/kg bw/d for methamidophos, this accounts for 0.8 and 10.8% of the ARfD. CONCLUSIONS: Even when considering OP residues from vegetables, fruits and other foods, there are no health concerns based on acute dietary exposure to OP residues from tea infusion. However, it is necessary to strengthen the management of the OP pesticides used on tea in China to reduce the risk of chronic dietary exposure to OPs from tea infusion.


Asunto(s)
Exposición Dietética/análisis , Compuestos Organofosforados/análisis , Residuos de Plaguicidas/análisis , Té/química , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Medición de Riesgo/métodos , Adulto Joven
19.
Small ; 13(14)2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28145634

RESUMEN

A nitrogen-doped 3D graphene foam assembled with nanoscroll structure is constructed via a facile mild-heating methodology using a polar molecule of formamide as the driving regent. The as-prepared graphene nanoscroll foam exhibits promising performance in organic pollutant removal with improved adsorption rate and high binding affinity, and is thought to be a novel adsorption material.

20.
Small ; 13(34)2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28692763

RESUMEN

Macroscopic porous graphene materials composed of graphene sheets have demonstrated their advantageous aspects in diverse application areas. It is essential to maximize their excellent performances by rationally controlling the sheet arrangement and pore structure. Bulk porous graphene materials with oriented pore structure and arrangement of graphene sheets are prepared by marrying electrolyte-assisted self-assembly and shear-force-induced alignment of graphene oxide sheets, and the super elasticity and anisotropic mechanical, electrical, and thermal properties induced by this unique structure are systematically investigated. Its application in pressure sensing exhibits ultrahigh sensitivity of 313.23 kPa-1 for detecting ultralow pressure variation below 0.5 kPa, and it shows high retention rate for continuously intercepting dye molecules with a high flux of ≈18.7 L m-2 h-1 bar-1 and a dynamic removal rate of 510 mg m-2 h-1 .

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