Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 85
Filtrar
1.
Microbiol Spectr ; 12(2): e0323123, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38189330

RESUMEN

The formation of reactive oxygen species is harmful and can destroy intracellular macromolecules such as lipids, proteins, and DNA, even leading to bacterial death. To cope with this situation, microbes have evolved a variety of sophisticated mechanisms, including antioxidant enzymes, siderophores, and the type VI secretion system (T6SS). However, the mechanism of oxidative stress resistance in Cupriavidus pinatubonensis is unclear. In this study, we identified Reut_A2805 as an OxyR ortholog in C. pinatubonensis, which positively regulated the expression of T6SS1 by directly binding to its operon promoter region. The study revealed that OxyR-regulated T6SS1 combats oxidative stress by importing iron into bacterial cells. Moreover, the T6SS1-mediated outer membrane vesicles-dependent iron acquisition pathway played a crucial role in the oxidative stress resistance process. Finally, our study demonstrated that the T6SS1 and siderophore systems in C. pinatubonensis exhibit different responses in combating oxidative stress under low-iron conditions, providing a comprehensive understanding of how bacterial iron acquisition systems function in diverse conditions.IMPORTANCEThe ability to eliminate reactive oxygen species is crucial for bacterial survival. Continuous formation of hydroperoxides can damage metalloenzymes, disrupt DNA integrity, and even result in cell death. While various mechanisms have been identified in other bacterial species to combat oxidative stress, the specific mechanism of oxidative stress resistance in C. pinatubonensis remains unclear. The importance of this study is that we elucidate the mechanism that OxyR-regulated T6SS1 combats oxidative stress by importing iron with the help of bacterial outer membrane vesicle. Moreover, the study highlights the contrasting responses of T6SS1- and siderophore-mediated iron acquisition systems to oxidative stress. This study provides a comprehensive understanding of bacterial iron acquisition and its role in oxidative stress resistance in C. pinatubonensis under low-iron conditions.


Asunto(s)
Estrés Oxidativo , Sideróforos , Sideróforos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Hierro/metabolismo , ADN/metabolismo , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica
2.
Small ; 20(5): e2305191, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37752759

RESUMEN

Metal halide perovskite colloidal quantum wells (CQWs) hold great promise for modern photonics and optoelectronics. However, current studies focus on Ruddlesden-Popper (R-P) phase perovskite CQWs that contain bilayers of monovalent long-chain alkylamomoniums between the separated perovskite octahedra layers. The bilayers are packed back-to-back via weak van der Waals interaction, resulting in inferior charge carrier transport and easier decomposition of perovskite. This report first creates a new type of perovskite colloidal multiple QWs (CMQWs) in the form of Dion-Jacobson (D-J) structure by introducing an asymmetric diammonium cation. Furthermore, the phase distribution is optimized by the synergistic effect of valeric acid and zwitterionic lecithin, finally achieving pure deep-blue emission at 435 nm with narrow full width at half maximum. The diammonium layer in D-J perovskite CMQWs features extremely short width of only ≈0.6 nm, thereby contributing to more effective charge carrier transport and higher stability. Through the continuous photoluminescence (PL) measurement and corresponding theoretical calculation, the higher stability of D-J perovskite CMQWs than that of R-P structural CMQWs is confirmed. This work reveals the inherent superior stability of D-J structural CMQWs, which opens a new direction for fabricating stable perovskite optoelectronics.

3.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 37(8): 1002-1010, 2023 Aug 15.
Artículo en Chino | MEDLINE | ID: mdl-37586802

RESUMEN

Objective: To investigate the effect of Kartogenin (KGN) combined with adipose-derived stem cells (ADSCs) on tendon-bone healing after anterior cruciate ligament (ACL) reconstruction in rabbits. Methods: After the primary ADSCs were cultured by passaging, the 3rd generation cells were cultured with 10 µmol/L KGN solution for 72 hours. The supernatant of KGN-ADSCs was harvested and mixed with fibrin glue at a ratio of 1∶1; the 3rd generation ADSCs were mixed with fibrin glue as a control. Eighty adult New Zealand white rabbits were taken and randomly divided into 4 groups: saline group (group A), ADSCs group (group B), KGN-ADSCs group (group C), and sham-operated group (group D). After the ACL reconstruction model was prepared in groups A-C, the saline, the mixture of ADSCs and fibrin glue, and the mixture of supernatant of KGN-ADSCs and fibrin glue were injected into the tendon-bone interface and tendon gap, respectively. ACL was only exposed without other treatment in group D. The general conditions of the animals were observed after operation. At 6 and 12 weeks, the tendon-bone interface tissues and ACL specimens were taken and the tendon-bone healing was observed by HE staining, c-Jun N-terminal kinase (JNK) immunohistochemical staining, and TUNEL apoptosis assay. The fibroblasts were counted, and the positive expression rate of JNK protein and apoptosis index (AI) were measured. At the same time point, the tensile strength test was performed to measure the maximum load and the maximum tensile distance to observe the biomechanical properties. Results: Twenty-eight rabbits were excluded from the study due to incision infection or death, and finally 12, 12, 12, and 16 rabbits in groups A-D were included in the study, respectively. After operation, the tendon-bone interface of groups A and B healed poorly, while group C healed well. At 6 and 12 weeks, the number of fibroblasts and positive expression rate of JNK protein in group C were significantly higher than those of groups A, B, and D (P<0.05). Compared with 6 weeks, the number of fibroblasts gradually decreased and the positive expression rate of JNK protein and AI decreased in group C at 12 weeks after operation, with significant differences (P<0.05). Biomechanical tests showed that the maximum loads at 6 and 12 weeks after operation in group C were higher than in groups A and B, but lower than those in group D, while the maximum tensile distance results were opposite, but the differences between groups were significant (P<0.05). Conclusion: After ACL reconstruction, local injection of a mixture of KGN-ADSCs and fibrin glue can promote the tendon-bone healing and enhance the mechanical strength and tensile resistance of the tendon-bone interface.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior , Adhesivo de Tejido de Fibrina , Animales , Conejos , Adipocitos , Adhesivo de Tejido de Fibrina/uso terapéutico , Células Madre
4.
Chemosphere ; 340: 139937, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37619754

RESUMEN

Versatile two-dimensional nanomaterials have offered a promising prospect to enhance the water purification efficiency and overcome the fouling obstacle in membrane technology. In this work, a graphitic carbon nitride (g-C3N4) nanosheet membrane intercalated with the nano-sized Fe-based metal-organic framework (MIL-100(Fe)) is developed for the enhanced removal of aqueous organic contaminants by synergically promoting separation and Fenton-like processes. The g-C3N4/MIL-100(Fe) membrane is constructed through a self-assembly route in which the nano-MIL-100(Fe) is anchored into g-C3N4 layers by the coordination bonds between Fe nodes and pyridinic N. The MIL-100(Fe) intercalation not only enlarges the interlayer spacing to raise the membrane permeability, but also expedites the electron transfer between Fe2+ and Fe3+ to improve the Fenton-like activity. With a stable water flux of 98.2 L m2·h-1·bar-1 under wide-range pH and pressures, the g-C3N4/MIL-100(Fe) membrane shows high dye removal efficiency (≥99%) and prominent self-cleaning ability. Mechanism insight proposes a combination of size exclusion, electrostatic interaction and steady radical generation. The intercalation of nano-MIL-100(Fe) into g-C3N4 membranes can realize the mutual promotion between separation and Fenton-like processes, the synergistic effect of which provides an effective and feasible strategy for aqueous pollution abatement.


Asunto(s)
Grafito , Purificación del Agua , Transporte de Electrón , Contaminación Ambiental , Agua
5.
Front Public Health ; 11: 1119352, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37006585

RESUMEN

Background: Menopausal women may experience menopausal syndrome and long-term effects caused by low estrogen levels, such as senile dementia and osteoporosis in the elderly. Most menopausal women may have misconceptions about menopause and low use of pharmacological interventions. These misconceptions may damage the quality of life and miss the critical period for preventing senile diseases. Thus, enhancing the awareness of menopausal women regarding psychosocial and physical changes through health education programs was a way to improve positive attitudes toward menopause and make further treatment options. Objectives: This study aimed to evaluate the effect of multidisciplinary health education based on lifestyle medicine on menopausal syndrome and lifestyle behaviors of menopausal women. Methods: The study was conducted in several hospitals in Chongqing, China. The two groups were from different hospitals with similar medical levels in order to reduce information contamination. It was designed as a clinical controlled trial in which the intervention group (n = 100) and control group (n = 87) were matched for age, age at menarche, menopausal symptoms and drug use status at enrollment. Women in the intervention group received multidisciplinary health education based on lifestyle medicine for 2 months while those in the control group received routine outpatient health guidance. Menopausal syndrome, physical activity and dietary status of participants were assessed before and after the intervention. Paired t-tests and Independent-sample t-tests were adopted for comparison within and between groups, respectively, in the normal variables. Wilcoxon signed-rank tests and Mann-Whitney U tests were adopted for comparison within and between group, respectively, in the abnormal variables. Categorical variables were tested using Pearson's χ2. P-value < 0.05 was statistically significant in statistical tests. Results: Post intervention testing indicated that menopausal syndrome of participants was significantly improved in the intervention group compared to the control group (P < 0.001). Between-group comparison showed a significant improvement of weekly energy expenditure of total physical activity (P = 0.001) and participation in exercise (P < 0.001) in the intervention group compared to the control group after the intervention. The dietary status of participants was significantly improved in the intervention group compared to the control group (P < 0.001). In the intervention group, the menopausal syndrome of participants improved more in the hormone drug group than in the non-hormone group (P = 0.007), as did the control group (P = 0.02). In the hormone drug group, the physical activity (P = 0.003) and dietary status (P = 0.001) mproved more in the intervention group than in the control group. Conclusions: The multidisciplinary health education based on lifestyle medicine was effective in improving the menopausal syndrome and healthy lifestyle behaviors of menopausal women. Studies with extended observation period and larger sample size are in need to evaluate the long-term scale-up effects of the multidisciplinary health education.


Asunto(s)
Menopausia , Calidad de Vida , Anciano , Femenino , Humanos , Ejercicio Físico , Educación en Salud , Estilo de Vida , Menopausia/psicología
6.
J Orthop Surg (Hong Kong) ; 31(1): 10225536231171057, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37075166

RESUMEN

INTRODUCTION: Flatfoot and patellar instability are both developmental limb deformities that occur frequently in adolescents. A high number of patients with both diseases can be seen in clinic, and there are no studies showing a correlation between the two. The goal of this study is to investigate the association between developmental patellar instability and flat feet in adolescents and its associated risk factors. METHODS: This experiment uses a cross-sectional study to select 74 adolescent patients with flat foot from a randomly selected middle school in this city since December 2021 and obtain relevant data. SPSS26.0 statistical software was used for data analysis. Quantitative data were expressed as mean ± standard deviation, and Pearson correlation coefficient was used for analysis. p < 0.05 indicates a statistically significant difference. RESULTS: A total of 74 people (40 men and 34 women) were included in this study. The correlation coefficients between Meary angle, Pitch angle, calcaneal valgus angle, CSI, BMI, and Beighton scores and knee joint Q angle are 0.358 (p < 0.01), -0.312 (p < 0.01), 0.403 (p < 0.01), 0.596 (p < 0.01), 0.427 (p < 0.01), and 0.293 (p < 0.05), respectively, indicating that flat foot, overweight, and Beighton scores are all correlated with Q angle. The correlation coefficients between Meary angle, Pitch angle, calcaneal valgus angle, CSI, and BMI were 0.431 (p < 0.01), -0.399 (p < 0.01), 0.319 (p < 0.01), and 0.563 (p < 0.01), respectively, indicating a correlation between flat foot and BMI. The correlation coefficients between Meary's angle, Pitch's angle, calcaneal valgus angle, CSI, and Beighton's score were 0.207 (p > 0.05), -0.240 (p < 0.05), 0.204 (p > 0.05), and 0.413 (p < 0.01), respectively, indicating a correlation between flat foot and Beighton's score. CONCLUSION: We believe that there is a significant correlation between adolescent flatfoot and patellar instability. Excessive weight and ligamental laxity during adolescent development are among the risk factors for flatfoot and patellar instability.


Asunto(s)
Pie Plano , Inestabilidad de la Articulación , Articulación Patelofemoral , Masculino , Humanos , Adolescente , Femenino , Pie Plano/epidemiología , Inestabilidad de la Articulación/epidemiología , Estudios Transversales , Factores de Riesgo , Estudios Retrospectivos
7.
Infect Drug Resist ; 16: 721-726, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36756610

RESUMEN

Background: Herpes zoster (HZ) is an acute herpetic skin disease resulting from the varicella-zoster virus. Typically, this condition is treated with a one-week administration of antiviral drugs, including famciclovir, which can effectively control the symptoms during the acute phase and prevent the occurrence of postherpetic neuralgia (PHN). Objective: To investigate whether a longer, two-week, regimen would enhance the capacity for famciclovir to reduce pain and prevent the occurrence of postherpetic neuralgia. Methods: HZ patients were randomly divided into two groups who were treated with famciclovir for either a one- or two-week period. Following their respective famciclovir treatments, patients were assessed for potential differences in pain intensity as evaluated at 1, 2, 4, 8 and 12 weeks post-treatment. In addition, the occurrence of postherpetic neuralgia at three months after treatment was compared between the two groups. Results: Of the 86 patients initially enrolled, 80 completed the study with N=40 randomly assigned to each of the two groups. Pain scores decreased significantly at 1, 2, 4, 8 and 12 weeks after famciclovir treatments. There were no significant differences in pain scores, and the incidence of postherpetic neuralgia occurrence between the two groups. There were no statistically significant differences in reducing pain intensity or frequency of postherpetic neuralgia between the one-week and two-week treatment protocols. Conclusion: It suggests that longer administration of famciclovir has no further benefit in the treatment of herpes zoster in our study.

8.
Toxics ; 11(2)2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36850972

RESUMEN

To investigate the heavy metal contamination of soil in a uranium mining area in northern Guangdong, a physicochemical evaluation method was used to evaluate the contaminated soil near the pit and tailings pond of the uranium mining area, determine its heavy metal content and evaluate its ecological risk using the Nemerow integrated contamination index, ground accumulation index and potential ecological risk index. The results show that the average content of nine heavy metal elements in the soil of the uranium mining area exceeds the background value of red soil in Guangdong Province. Three pollution evaluation indices all indicate that Cd, As and U have serious pollution and high ecological risk, while the remaining elements are weakly polluted and the potential ecological risk of the six sampling sites all show very strong risk. On this basis, soil ecotoxicity was evaluated using ostracods (Cypridopsis vidua and Heterocypris sp.), Vibrio fischeri and Vicia faba L. Higher concentrations of heavy metals at individual sites (T1, T2, P2) resulted in higher mortality of ostracods, higher inhibition of Vibrio fischeri luminescence and a significant reduction in germination and pigmentation of broad beans. The results of the biotoxicity evaluation were consistent with the results of the physicochemical evaluation, allowing for a more direct and comprehensive evaluation of the ecotoxic effects of uranium and heavy metals in the mine soils.

9.
Sci Total Environ ; 864: 161080, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36574852

RESUMEN

Ferrate(VI) is a green oxidant and can effectively oxidize micropollutants. However, the instability of Fe(VI), i.e., self-decomposition, in the aqueous solution limited its application. Herein, it was found that the degradation of phenolic substances had been substantially improved through the combination of Fe(VI) with NaClO. At the condition of pH 8.0, 50 µM of Fe(VI) degraded 18.66 % of BPA (bisphenol A) at 0.5 min or 21.67 % of phenol at 2 min. By contrast, Fe(VI)/NaClO (50/10 µM) oxidized 38.21 % of BPA at 0.5 min or 38.08 % of phenol at 2 min with a synergistic effect. At the end of the reaction, the concentration of Fe(VI) in Fe(VI)/NaClO (50/10 µM) was 28.97 µM for BPA degradation, higher than the 25.62 µM of Fe(VI) group. By active species analysis, intermediate iron species [i.e., Fe(V) and Fe(IV)] played a vital role in the synergistic effect in Fe(VI)/NaClO system, which would react with the applied NaClO to regenerate Fe(VI). In natural water, the Fe(VI)/NaClO could also degrade phenolic substances of natural organic matter (NOM). Although the NaClO reagent was applied, disinfection by-products (DBPs) formation potential decreased by 22.75 % of the raw sample after Fe(VI)/NaClO treatment. Significantly, THMs, mainly caused by phenolic substances of NOM, even declined by 29.18 % of raw sample. Based on that, this study explored a novel ferrate(VI) oxidation system using the cheap NaClO reagent, which would present a new insight on ferrate(VI) application.

10.
Sci Total Environ ; 858(Pt 2): 159934, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36343821

RESUMEN

Microplastics are ubiquitous in the natural environment and have the potential to endanger the natural environment, ecology and even human health. A series of microfluidic experiments by using soft lithography technology were carried out to investigate the effect of flow rate, particle volume fraction, particle size and pore/throat ratio on microplastics migration and deposition at the pore scale. We discovered a range of deposition patterns of the spherical microplastics from no particle deposition, to discontinuous particle layer, and to continuous particle layers in the retained liquid in the pores, depending on the particle size and volume fraction. Several metrics, including air saturation, probability of particle detainment, expansion ratio and thickness of residual liquid, were quantified to examine the role of various parameters on particle migration and retention of microplastics. At low flow rate (Q = 0.05 µL/min), microplastics migration and deposition were sensitive to changes in particle volume fraction, particle size and pore/throat ratio. In contrast, at high flow rates (Q > 5 µL/min), the migration and retention of particles were mainly controlled by strongly channelized air invasion pattern, while the particle volume fraction, particle size and pore/throat size ratio have only secondary influence. At intermediate range of flow rates, microplastics migration and deposition were dramatically impacted by flow rate, particle volume fraction, particle size and pore/throat ratio. This work improves the understanding of the mechanisms of particle migration and retention in porous media and can provide a reference for more accurate assessment of the exposure levels and times of microplastics in soil and groundwater systems.


Asunto(s)
Microplásticos , Plásticos , Humanos , Porosidad , Suelo , Tamaño de la Partícula
11.
Water Res ; 229: 119452, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36502655

RESUMEN

Oxidation pretreatments prior to ultrafiltration are hindered by the need for energy input and sludge disposal. Herein, a simulated sunlight-induced natural organic matter (NOM) for peroxymonosulfate (PMS) activation was used as pretreatment to alleviate ultrafiltration membrane fouling caused by NOM itself in the Songhua River water. When light intensity was over 100 mW/cm2, the pretreatment removed NOM effectively, characterized with UV254, dissolved organic carbon (DOC) and maximum fluorescent intensity (Fmax), and improved filtration flux. At 200 mW/cm2 light intensity and 0.5 mM PMS, 57.5% of UV254 and 18.5% of DOC were removed, and humic-like fluorescent component was degraded by 84%-94% while ∼60% for protein-like substance. Membrane flux was increased by 94%, and reversible and irreversible fouling resistances were reduced by 62.4% and 51.9%, respectively. Both total fouling index (TFI) and hydraulic irreversible fouling index (HIFI) were moderately correlated with the DOC, whereas they prominently correlated with the UV254 and the Fmaxs of all fluorescence components, which could be served as key indicators to predict and control membrane fouling. Mathematical modeling showed that the pretreatment alleviated the fouling in the membrane pores and cake layer. The simulated sunlight-induced NOM (3NOM* and eaq¯) could activate PMS to form active species, which enabled to oxidize high molecular weight (MW) substances and mineralize low MW compounds in NOM as well as hinder their linking with inorganic cations, thereby reducing organic and inorganic membrane fouling simultaneously. This study may provide a new strategy for decentralized potable water treatment, especially in a single household or community.


Asunto(s)
Ultrafiltración , Purificación del Agua , Luz Solar , Membranas Artificiales , Peróxidos
12.
BMC Musculoskelet Disord ; 23(1): 1112, 2022 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-36544111

RESUMEN

BACKGROUND: The purpose of this study was to evaluate the effect of varying the different correction angles of hindfoot osteotomy orthosis on the biomechanical changes of the adjacent joints after triple arthrodesis in adult patients with stiff clubfoot to determine the optimal hindfoot correction angle and provide a biomechanical basis for the correction of hindfoot deformity in patients with stiff clubfoot. METHODS: A 26-year-old male patient with a stiff left clubfoot was selected for the study, and his ankle and foot were scanned using dual-source computed tomography. A three-dimensional finite element model of the ankle was established, and after the validity of the model was verified by plantar pressure experiments, triple arthrodesis was simulated to analyze the biomechanical changes of the adjacent joints under the same load with "3°" of posterior varus, "0°" of a neutral position and "3°, 6°, 9°" of valgus as the correction angles. RESULTS: The peak plantar pressure calculated by the finite element model of the clubfoot was in good agreement with the actual plantar pressure measurements, with an error of less than 1%. In triple arthrodesis, the peak von Mises stress in the adjacent articular cartilage was significantly different and less than the preoperative stress when the corrected angle of the hindfoot was valgus "6°". In comparison, the peak von Mises stress in the adjacent articular cartilage was not significantly different in varus "3°", neutral "0°", valgus "3°" and valgus "9°" compared with the preoperative stress. CONCLUSION: The results of this study showed that different angles of hindfoot correction in triple arthrodesis did not increase the peak von Mises stress in the adjacent joints, which may not lead to the development of arthritis in the adjacent joint, and a hindfoot correction angle of "6°" of valgus significantly reduced the peak von Mises stress in the adjacent joints after triple arthrodesis.


Asunto(s)
Pie Equinovaro , Adulto , Masculino , Humanos , Pie Equinovaro/diagnóstico por imagen , Pie Equinovaro/cirugía , Articulación del Tobillo/diagnóstico por imagen , Articulación del Tobillo/cirugía , Tobillo , Artrodesis/métodos , Extremidad Inferior , Fenómenos Biomecánicos
13.
Materials (Basel) ; 15(22)2022 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-36431626

RESUMEN

The erosion of the valve core causes valve failure problems. Thus, a novel method to extend the erosion resistance of the valve was innovatively proposed, namely, nanosecond laser ablation micro-pits on the substrate surface and high velocity oxygen fuel (HVOF) spraying WC coating to extend the erosion resistance of the valve. The characterization and evaluation of the erosion resistance of the WC-sprayed coating after the pretreatment of the 3Cr13 substrate surface polishing/grit blasting/nanosecond laser ablation circular micro-dimple were conducted using the unit coupon erosion test of liquid-solid two-phase flow, followed by the test evaluation and analysis of the erosion resistance test of the WC coating after different pretreatments of the full-size valve core. Results showed that the micro-dimple pretreatment on the surface of the 3Cr13 substrate increased the contact area rate and bonding strength of the substrate and the WC coating. By taking erosion volume loss as the evaluation index, the erosion resistance of the micro-dimple pretreatment on the surface of the 3Cr13 substrate was increased by about 31.98% compared with that of the polishing pretreatment. Therefore, the new method of surface nanosecond laser texture pretreatment and HVOF-spraying WC coating can effectively improve the erosion resistance of the valve.

14.
Colloids Surf B Biointerfaces ; 220: 112869, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36244132

RESUMEN

Recently, red emissive carbon dots (R-CDs) have drawn widespread attention on account of their desirable fluorescence properties and good biocompatibility. Despite great efforts, facile synthesis of R-CDs for cellular imaging remains challenging and the fluorescence mechanism of R-CDs is still elusive. Herein, p-phenylenediamine-derived R-CDs with excitation-independency were successfully obtained through a facile solvothermal approach together with proportional precipitation. The fluorescent solvatochromism of R-CDs is realized, while high polarity leads to higher degree of dipole interaction between R-CDs and different solvents, favoring for emissive red-shift. Furthermore, density functional theory is adopted to explore the optical and electronic characteristics of some polycyclic aromatic molecules. Among different configurations, pyridine nitrogen and carbonyl bonds could relatively increase the charge density and significantly narrow the band gap, which can provide a crucial theoretical basis for the precise preparation of R-CDs. Moreover, R-CDs possess favorable cellular imaging ability, which indicates their potential for a promising candidate as fluorescence probes in bioimaging.


Asunto(s)
Carbono , Puntos Cuánticos , Carbono/química , Puntos Cuánticos/química , Espectrometría de Fluorescencia , Nitrógeno , Solventes/química , Colorantes Fluorescentes/química
15.
Biomaterials ; 288: 121706, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35953328

RESUMEN

Cancer vaccines are viewed as a promising immunotherapy to eradicate malignant tumors and aim to elicit the patients' own tumor-specific immune response against tumor cells. However, few cancer vaccines have been applied due to the low immunogenicity of antigen and invalidation of adjuvant. Herein, we designed a tumor microenvironment (TME) responsive MnO2-melittin nanoparticles (M-M NPs). The M-M NPs consumed glutathione and produced •OH via Fenton-like reaction in the mimic TME, specifically caused tumor cell death in vitro, activated cGAS-STING pathway in vitro and promoted the maturation of antigen-presenting cells in vitro and in vivo to elicit systemic anti-tumor immune response including the augmentation of tumor-specific T cells and more productions of pro-inflammatory cytokines and chemokines, which all were stronger than MnO2 NPs and melittin. The anti-tumor effects of M-M NPs were evaluated in three subcutaneous tumor models and the B16-F10 lung metastasis model and the tumor growth and lung metastasis were more obviously inhibited in the M-M NPs treated mice, compared with MnO2 NPs and melittin treatments. More importantly, only M-M NPs promoted the MHC-I cross-dressing by dendritic cells to prime tumor-specific CD8+ T cells and remarkably suppressed the growth of left tumors if express cognate antigen while treating on the right in the bilateral tumor model. Our findings proposed a strategy to enhance the cancer vaccine efficiency which showed great therapeutic effect on tumor immunotherapy.


Asunto(s)
Vacunas contra el Cáncer , Neoplasias Pulmonares , Nanopartículas , Animales , Antígenos , Linfocitos T CD8-positivos , Inmunidad , Inmunoterapia , Neoplasias Pulmonares/tratamiento farmacológico , Compuestos de Manganeso , Meliteno , Nanopartículas del Metal , Ratones , Óxidos , Microambiente Tumoral
16.
Toxics ; 10(7)2022 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-35878254

RESUMEN

The development of uranium mines has been necessary to obtain abundant and scarce uranium resources, but they also bring inevitable radioactive contamination to the surrounding soil, rivers and lakes. This paper explores the sensitivity of Cypridopsis vidua to the radioactive element uranium and the heavy elements cadmium and copper with single and combined acute toxicity experiments and combined toxicity model predictions. The results from the single toxicity experiments showed that the degree of toxic effects was cadmium > copper > uranium. The combined toxicity experiments showed that the compound toxicity of U-Cd and U-Cu was higher than the weakest component and lower than the strongest component, whereas the compound toxicity of Cd-Cu was higher than either of its components. When the overall proportion of a more toxic metal was increased, its mixed toxicity also increased, and vice versa. Combined toxicity predictions showed that the U-Cd combination was best described by the concentration additive (CA) model, the independent action (IA) model was more applicable to the Cd-Cu combination, and the most applicable model for the U-Cu combination changed depending on the concentration gradient. The acute toxicity data from this study provide a reference for the development of wastewater discharge standards for uranium mines, enriches the data related to the toxicity of uranium for ostracods and deepens the understanding of the threat of uranium pollution to aquatic ecosystems.

17.
Small ; 18(15): e2108120, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35253372

RESUMEN

InP quantum dots (QDs) have attracted much attention owing to their nontoxic properties and shown great potential in optoelectronic applications. Due to the surface defects and lattice mismatch, the interfacial structure of InP/ZnS QDs plays a significant role in their performance. Herein, the formation of In-S and Sx -In-P1-x interlayers through anion exchange at the shell-growth stage is revealed. More importantly, it is proposed that the composition of interface is dependent on the synergistic effect of halogen ions and shelling temperature. High shelling temperature contributes to the optical performance improvement resulting from the formation of interlayers, besides the thicker ZnS shell. Moreover, the effect relates to the halogen ions where I- presents more obvious enhancement than Br- and Cl- , owing to their different ability to coordinate with In dangling bonds, which are inclined to form In-S and Sx -In-P1-x bonds. Further, the anion exchange under I- -rich environment causes a blue-shift of emission wavelength with shelling temperature increasing, unobserved in a Cl- - or Br- -rich environment. It contributes to the preparation of highly efficient blue emissive InP/ZnS QDs with emission wavelength of 473 nm, photoluminescence quantum yield of ≈50% and full width at half maximum of 47 nm.


Asunto(s)
Puntos Cuánticos , Halógenos , Puntos Cuánticos/química , Sulfuros/química , Temperatura , Compuestos de Zinc
18.
Biomed Res Int ; 2022: 2146236, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35299894

RESUMEN

This paper addresses the mixture symptom mention problem which appears in the structuring of Traditional Chinese Medicine (TCM). We accomplished this by disassembling mixture symptom mentions with entity relation extraction. Over 2,200 clinical notes were annotated to construct the training set. Then, an end-to-end joint learning model was established to extract the entity relations. A joint model leveraging a multihead mechanism was proposed to deal with the problem of relation overlapping. A pretrained transformer encoder was adopted to capture context information. Compared with the entity extraction pipeline, the constructed joint learning model was superior in recall, precision, and F1 measures, at 0.822, 0.825, and 0.818, respectively, 14% higher than the baseline model. The joint learning model could automatically extract features without any extra natural language processing tools. This is efficient in the disassembling of mixture symptom mentions. Furthermore, this superior performance at identifying overlapping relations could benefit the reassembling of separated symptom entities downstream.


Asunto(s)
Aprendizaje Automático , Registros Médicos , Medicina Tradicional China , Evaluación de Síntomas/métodos , Humanos
19.
Water Res ; 214: 118167, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35196618

RESUMEN

To improve H2O2 generation and Fe3+/Fe2+ cycle simultaneously for enhancing Electro-Fenton performance, the electrode aeration (EA) and hydroxylamine sulfate (HA) were coupled. With dimethyl phthalate (DMP) as main target contaminant, combination of HA and EA greatly accelerated the degradation of DMP and exhibited a synergy in the pH of 2.0-6.9 through promoting the key reactions, including electrochemical two-electron reduction of O2 into H2O2 and redox cycles of Fe3+/Fe2+, which then improved the generation of hydroxyl radicals (·OH). The coupling EA and HA reduced the use of HA and converted most of HA into environment-friendly N2 (60.1-62.1% of HA products), while HA/solution aeration(SA) system consumed HA rapidly and the generated N2 only accounted for 5.8-6.7% of HA products. Furthermore, compared with HA/SA and EA Electro-Fenton systems, enhancement degree of DMP degradation in HA/EA Electro-Fenton process was higher in actual waterbody than in ultrapure water. The coupling EA and HA in the Electro-Fenton process could solve the low Fe3+/Fe2+ cycle efficiency and low H2O2 production simultaneously, and improve the N2 selectivity of HA transformation, which advanced its application in practical environmental remediation.

20.
Front Cell Dev Biol ; 10: 1031872, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36589737

RESUMEN

Temporal lobe epilepsy (TLE) is the most common form of epilepsy with focal seizures which in some conditions can develop into secondarily generalized tonic-clonic seizures by the propagation of epileptic activities in the temporal lobe to other brain areas. The nucleus accumbens (NAc) has been suggested as a treatment target for TLE as accumulating evidence indicates that the NAc, especially its shell, participates in the process of epileptic seizures of patients and animal models with TLE. The majority of neurons in the NAc are GABAergic medium spiny neurons (MSNs) expressing dopamine receptor D1 (D1R) or dopamine receptor D2 (D2R). However, the direct evidence of the NAc shell participating in the propagation of TLE seizures is missing, and its cell type-specific modulatory roles in TLE seizures are unknown. In this study, we microinjected kainic acid into basolateral amygdala (BLA) to make a mouse model of TLE with initial focal seizures and secondarily generalized seizures (SGSs). We found that TLE seizures caused robust c-fos expression in the NAc shell and increased neuronal excitability of D1R-expressing MSN (D1R-MSN) and D2R-expressing MSN (D2R-MSN). Pharmacological inhibition of the NAc shell alleviated TLE seizures by reducing the number of SGSs and seizure stages. Cell-type-specific chemogenetic inhibition of either D1R-MSN or D2R-MSN showed similar effects with pharmacological inhibition of the NAc shell. Both pharmacological and cell-type-specific chemogenetic inhibition of the NAc shell did not alter the onset time of focal seizures. Collectively, these findings indicate that the NAc shell and its D1R-MSN or D2R-MSN mainly participate in the propagation and generalization of the TLE seizures.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...