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2.
Adv Tech Stand Neurosurg ; 52: 63-72, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39017786

RESUMEN

OBJECTIVE: Transcortical approaches using a spatula-based retraction system have traditionally been used for the microsurgical resection of deep-seated intraventricular and parenchymal brain tumors. Recently, transparent cylindrical or tubular retractors have been developed to provide a stable corridor to access deeper brain lesions and perform bimanual microsurgical resection. The flexible endoports minimize brain retraction injury during surgery and, along with the superior vision of endoscopes, offer several advantages over standard microsurgery. In this chapter, we describe the surgical technique of the endoport-guided endoscopic excision of deep-seated intraaxial brain tumors. METHODS: The endoscopic endoport technique that we use at our institution for the surgical management of intraventricular and intraparenchymal brain tumors has been described in detail with illustrative cases. RESULTS: Results from the literature review of intraventricular and intraparenchymal port surgery were analyzed, and the feasibility and safety of this technique were discussed. Surgical complication avoidance and management were highlighted. The port technique offers numerous potential advantages, including (1) reducing focal brain injury by distributing retraction forces homogenously, (2) minimizing white matter disruption and the risk of fascicle injury during cannulation, (3) ensuring the stability of the surgical corridor during the procedure, (4) preventing inadvertent expansion of the corticectomy and white fiber tract dissection throughout surgery, and (5) protecting the surrounding tissues against iatrogenic injuries caused by instrument entry and reentry. CONCLUSION: The endoport-assisted endoscopic technique is safe and offers an effective alternative option for the resection of intraventricular and intraparenchymal lesions.


Asunto(s)
Neoplasias Encefálicas , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Encefálicas/cirugía , Neuroendoscopía/métodos , Neuroendoscopía/instrumentación , Procedimientos Neuroquirúrgicos/métodos
3.
Biofabrication ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38981495

RESUMEN

One ever-evolving and ever-demanding critical human endeavour is the provision of food security for the growing world population. It could be done by adopting sustainable agriculture through horizontal (expanding the aerable land area) and vertical (intensifying agriculture through sound technological approaches) interventions. Customised formulated nanomaterials have numerous advantages. With their specialised physicochemical properties, some nanoparticulised materials improve plant's natural development and stress tolerance and some other are good nanocarriers. Nanocarriers in agriculture often coat chemicals to form composites having utilities with crop productivity enhancement abilities, environmental management (like ecotoxicity reduction ability), and biomedicines (like the ability of controlled and targeted release of useful nanoscale drugs). The Ag, Fe, Zn, TiO2, ZnO, SiO2 and MgO nanoparticles often employed in advanced agriculture are covered here. Some nanoparticles used for various extended purposes in modern farming practices, including disease diagnostics and seed treatment are covered too. Thus, nanotechnology has revolutionised agrotechnology, which holds promises to transform agricultural (eco)system as a whole to ensure food security in future. Considering the available literature, the article further probes the emergent regulatory issues governing the synthesis and use of nanomaterials in the agriculture sector. If applied responsibly, nanomaterials could help improve soil health. The article provides an overview of the used nanomaterials in distribution of biomolecules, to aid in devising a safer and eco-friendly sustainable agriculture strategy. Through this, agri-systems depending on advanced farming practices might function more effectively and enhance agri-productivity to meet the food demand of the rising world population.

4.
Front Neurosci ; 18: 1399923, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38988765

RESUMEN

Introduction: Cognitive dysfunction is commonplace in Motor Neurone Disease (MND). However, due to the prominent motor symptoms in MND, assessing patients' cognitive function through traditional cognitive assessments, which oftentimes require motoric responses, may become increasingly challenging as the disease progresses. Oculomotor pathways are apparently resistant to pathological degeneration in MND. As such, abnormalities in oculomotor functions, largely driven by cognitive processes such as saccades and smooth pursuit eye movement, may be reflective of frontotemporal cognitive deficits in MND. Thus, saccadic and smooth pursuit eye movements may prove to be ideal mechanistic markers of cognitive function in MND. Methods: To ascertain the utility of saccadic and smooth pursuit eye movements as markers of cognitive function in MND, this review summarizes the literature concerning saccadic and smooth pursuit eye movement task performance in people with MND. Results and discussion: Of the 22 studies identified, noticeable patterns suggest that people with MND can be differentiated from controls based on antisaccade and smooth pursuit task performance, and thus the antisaccade task and smooth pursuit task may be potential candidates for markers of cognition in MND. However, further studies which ascertain the concordance between eye tracking measures and traditional measures of cognition are required before this assumption is extrapolated, and clinical recommendations are made. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=376620, identifier CRD42023376620.

5.
Mater Today Bio ; 27: 101139, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39027679

RESUMEN

The prevalence of polymer usage in everyday activities has emerged as a detriment to both human life and the environment. A large number of studies describe severe impacts of micropolymers (MP) and nanopolymers (NP) on various organ systems, including the endocrine system. Additionally, plasticizers utilized as additives have been identified as endocrine-disrupting chemicals (EDCs). MP/NP, along with associated plasticizers, affect principal signalling pathways of endocrine glands such as the pituitary, thyroid, adrenal, and gonads, thereby disrupting hormone function and metabolic processes crucial for maintaining homeostasis, fertility, neural development, and fetal growth. This review delves into the sources, distribution, and effects of micropolymers, nanopolymers, and associated plasticizers acting as EDCs. Furthermore, it provides a detailed review of the mechanisms underlying endocrine disruption in relation to different types of MP/NP.

6.
J Neuroinflammation ; 21(1): 174, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39014482

RESUMEN

BACKGROUND: Specific microglia responses are thought to contribute to the development and progression of neurodegenerative diseases, including Parkinson's disease (PD). However, the phenotypic acquisition of microglial cells and their role during the underlying neuroinflammatory processes remain largely elusive. Here, according to the multiple-hit hypothesis, which stipulates that PD etiology is determined by a combination of genetics and various environmental risk factors, we investigate microglial transcriptional programs and morphological adaptations under PARK7/DJ-1 deficiency, a genetic cause of PD, during lipopolysaccharide (LPS)-induced inflammation. METHODS: Using a combination of single-cell RNA-sequencing, bulk RNA-sequencing, multicolor flow cytometry and immunofluorescence analyses, we comprehensively compared microglial cell phenotypic characteristics in PARK7/DJ-1 knock-out (KO) with wildtype littermate mice following 6- or 24-h intraperitoneal injection with LPS. For translational perspectives, we conducted corresponding analyses in human PARK7/DJ-1 mutant induced pluripotent stem cell (iPSC)-derived microglia and murine bone marrow-derived macrophages (BMDMs). RESULTS: By excluding the contribution of other immune brain resident and peripheral cells, we show that microglia acutely isolated from PARK7/DJ-1 KO mice display a distinct phenotype, specially related to type II interferon and DNA damage response signaling, when compared with wildtype microglia, in response to LPS. We also detected discrete signatures in human PARK7/DJ-1 mutant iPSC-derived microglia and BMDMs from PARK7/DJ-1 KO mice. These specific transcriptional signatures were reflected at the morphological level, with microglia in LPS-treated PARK7/DJ-1 KO mice showing a less amoeboid cell shape compared to wildtype mice, both at 6 and 24 h after acute inflammation, as also observed in BMDMs. CONCLUSIONS: Taken together, our results show that, under inflammatory conditions, PARK7/DJ-1 deficiency skews microglia towards a distinct phenotype characterized by downregulation of genes involved in type II interferon signaling and a less prominent amoeboid morphology compared to wildtype microglia. These findings suggest that the underlying oxidative stress associated with the lack of PARK7/DJ-1 affects microglia neuroinflammatory responses, which may play a causative role in PD onset and progression.


Asunto(s)
Inflamación , Lipopolisacáridos , Ratones Noqueados , Microglía , Proteína Desglicasa DJ-1 , Animales , Proteína Desglicasa DJ-1/deficiencia , Proteína Desglicasa DJ-1/genética , Proteína Desglicasa DJ-1/metabolismo , Microglía/metabolismo , Microglía/patología , Microglía/efectos de los fármacos , Ratones , Lipopolisacáridos/toxicidad , Lipopolisacáridos/farmacología , Inflamación/patología , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/genética , Humanos , Ratones Endogámicos C57BL , Enfermedades Neuroinflamatorias/patología , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/inducido químicamente , Enfermedades Neuroinflamatorias/genética
7.
Microsyst Nanoeng ; 10: 74, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38855359

RESUMEN

Smart, low-cost and portable gas sensors are highly desired due to the importance of air quality monitoring for environmental and defense-related applications. Traditionally, electrochemical and nondispersive infrared (IR) gas sensors are designed to detect a single specific analyte. Although IR spectroscopy-based sensors provide superior performance, their deployment is limited due to their large size and high cost. In this study, a smart, low-cost, multigas sensing system is demonstrated consisting of a mid-infrared microspectrometer and a machine learning algorithm. The microspectrometer is a metasurface filter array integrated with a commercial IR camera that is consumable-free, compact ( ~ 1 cm3) and lightweight ( ~ 1 g). The machine learning algorithm is trained to analyze the data from the microspectrometer and predict the gases present. The system detects the greenhouse gases carbon dioxide and methane at concentrations ranging from 10 to 100% with 100% accuracy. It also detects hazardous gases at low concentrations with an accuracy of 98.4%. Ammonia can be detected at a concentration of 100 ppm. Additionally, methyl-ethyl-ketone can be detected at its permissible exposure limit (200 ppm); this concentration is considered low and nonhazardous. This study demonstrates the viability of using machine learning with IR spectroscopy to provide a smart and low-cost multigas sensing platform.

8.
Clin Pharmacol Ther ; 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38847597

RESUMEN

Administration of a new drug candidate in a first-in-human (FIH) clinical trial is a particularly challenging phase in drug development and is especially true for immunomodulators, which are a diverse and complex class of drugs with a broad range of mechanisms of action and associated safety risks. Risk is generally greater for immunostimulators, in which safety concerns are associated with acute toxicity, compared to immunosuppressors, where the risks are related to chronic effects. Current methodologies for FIH dose selection for immunostimulators are focused primarily on identifying the minimum anticipated biological effect level (MABEL), which has often resulted in sub-therapeutic doses, leading to long and costly escalation phases. The Health and Environmental Sciences Institute (HESI) - Immuno-Safety Technical Committee (ITC) organized a project to address this issue through two complementary approaches: (i) an industry survey on FIH dose selection strategies and (ii) detailed case studies for immunomodulators in oncology and non-oncology indications. Key messages from the industry survey responses highlighted a preference toward more dynamic PK/PD approaches as in vitro assays are seemingly not representative of true physiological conditions for immunomodulators. These principles are highlighted in case studies. To address the above themes, we have proposed a revised decision tree, which expands on the guidance by the IQ MABEL Working Group (Leach et al. 2021). This approach facilitates a more refined recommendation of FIH dose selection for immunomodulators, allowing for a nuanced consideration of their mechanisms of action (MOAs) and the associated risk-to-benefit ratio, among other factors.

9.
Lipids Health Dis ; 23(1): 174, 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38851752

RESUMEN

BACKGROUND: Obesity is a metabolic syndrome where allelic and environmental variations together determine the susceptibility of an individual to the disease. Caloric restriction (CR) is a nutritional dietary strategy recognized to be beneficial as a weight loss regime in obese individuals. Preconceptional parental CR is proven to have detrimental effects on the health and development of their offspring. As yet studies on maternal CR effect on their offspring are well established but paternal CR studies are not progressing. In current study, the impact of different paternal CR regimes in diet-induced obese male Wistar rats (WNIN), on their offspring concerning metabolic syndrome are addressed. METHODS: High-fat diet-induced obese male Wistar rats were subjected to caloric restriction of 50% (HFCR-I) and 40% (HFCR-II) and then they were mated with normal females. The male parent's reproductive function was assessed by sperm parameters and their DNMT's mRNA expression levels were also examined. The offspring's metabolic function was assessed by physiological, biochemical and molecular parameters. RESULTS: The HFCR-I male parents have shown reduced body weights, compromised male fertility and reduced DNA methylation activity. Further, the HFCR-I offspring showed attenuation of the AMPK/SIRT1 pathway, which is associated with the progression of proinflammatory status and oxidative stress. In line, the HFCR-I offspring also developed altered glucose and lipid homeostasis by exhibiting impaired glucose tolerance & insulin sensitivity, dyslipidemia and steatosis. However, these effects were largely mitigated in HFCR-II offspring. Regarding the obesogenic effects, female offspring exhibited greater susceptibility than male offspring, suggesting that females are more prone to the influences of the paternal diet. CONCLUSION: The findings highlight that HFCR-I resulted in paternal undernutrition, impacting the health of offspring, whereas HFCR-II largely restored the effects of a high-fat diet on their offspring. As a result, moderate caloric restriction has emerged as an effective weight loss strategy with minimal implications on future generations. This underscores the shared responsibility of fathers in contributing to sperm-specific epigenetic imprints that influence the health of adult offspring.


Asunto(s)
Restricción Calórica , Metilación de ADN , Dieta Alta en Grasa , Obesidad , Ratas Wistar , Sirtuina 1 , Animales , Sirtuina 1/metabolismo , Sirtuina 1/genética , Dieta Alta en Grasa/efectos adversos , Obesidad/metabolismo , Obesidad/etiología , Masculino , Femenino , Ratas , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Transducción de Señal , Embarazo
12.
Membranes (Basel) ; 14(6)2024 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-38921490

RESUMEN

This paper presents the results of adsorption and permeation experiments of hydrogen and methane at elevated temperatures on a carbon-based nanoporous membrane material provided by Fraunhofer IKTS. The adsorption of pure components was measured between 90 °C and 120°C and pressures up to 45 bar. The Langmuir adsorption isotherm shows the best fit for all data points. Compared to available adsorption isotherms of H2 and CH4 on carbon, the adsorption on the investigated nanoporous carbon structures is significantly lower. Single-component permeation experiments were conducted on membranes at temperatures up to 220 °C. After combining the experimental results with a Maxwell-Stefan surface diffusion model, Maxwell-Stefan surface diffusion coefficients Dis were calculated. The calculated values are in line with an empirical model and thus can be used in future multi-component modeling approaches in order to better analyze and design a membrane system. The published adsorption data fill a gap in the available adsorption data for CH4 and H2.

13.
Front Bioeng Biotechnol ; 12: 1362681, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38903193

RESUMEN

Chemotherapy drugs like doxorubicin (Dox) are widely used in middle-income countries around the world to treat various types of cancers, including breast cancer. Although they are toxic, they are still widely used to treat cancer. Delivering chemotherapy drugs directly to cancer cells to reduce side effects remains a challenge. Moreover, modern research gave rise to cancer stem cell theory, which implicated cancer stem cells in tumor initiation, progression, and relapse. This makes it imperative to target cancer stem cells to achieve complete remission. Our work highlights the development of an exosome-based targeted drug delivery vehicle. These exosomes were isolated from mature dendritic cells (mDCs) and encapsulated with doxorubicin (ExoDS). Our results showed that ExoDS specifically targeted breast cancer cells and breast cancer stem cells. Further analysis revealed that ExoDS did not induce any significant apoptosis in healthy mammary cells and peripheral blood mononuclear cells (PBMCs) isolated from healthy individuals and breast cancer patients. ExoDS was also found to target circulating tumor cells (CTCs) isolated from patient blood. ExoDS also showed equal efficiency compared to free doxorubicin in vivo. We also observed that ExoDS reduced the expression of cancer stem cell markers in murine tumor tissues. Altogether, this work provides novel insights into how mDC-derived exosomes can be used to specifically target cancer cells and cancer stem cells.

14.
J Antibiot (Tokyo) ; 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890385

RESUMEN

Antibiotic resistant is the major concern in public health to control the infectious diseases. MRSA (Methicillin-resistant Staphylococcus aureus) is a significant concern in healthcare settings due to its resistance to many antibiotics, including methicillin and other beta-lactams. MRSA infection difficult to treat and increases the risk of complications. Here, we have tested a series of highly condensed heterocyclic derivatives of pyrrolo[1,2-a][1,4]benzodiazepines. Compounds were tested against both, Gram-positive bacteria, Staphylococcus aureus and S. epidermidis, and Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, to assess the antimicrobial efficacy. Compared to Gram-negative bacteria, compounds showed much stronger antibacterial activity against Gram-positive bacteria. SM-5 [Ethyl2-(7-(4-chlorophenyl)-4-methoxy-6,7,8,13-tetrahydro-5H-benzo[e]benzo[5,6][1,4]diazepino[2,1-a]isoindol-15-yl)acetate] derivative was selected as best on the basis of higher therapeutic index among the tested compounds, showed MIC value of 7.81 µg. ml-1 against Staphylococcus strains. Molecular docking analysis between cell wall biosynthesis protein of S. aureus and SM-5 revealed that PBP2a showed the highest binding energy (-8.3 Kcal mol-1), followed by beta-lactam-inducible PBP4 (-7.7 Kcal mol-1), and lipoteichoic acid synthase (-7.5 Kcal mol-1) which is comparably higher than methicillin. Ground state energy calculations by DFT analysis revealed that compound SM-5 and SM-6, almost have equal electronegativity 0.11018 au which also satisfy the quality of the compound reactivity. Analysis of their biofilm inhibition in vitro and in silico toxicity analysis demonstrated their substantial potential to be a kind of future lead antibiotic.

15.
J Pharm Bioallied Sci ; 16(Suppl 2): S1776-S1783, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38882761

RESUMEN

Background: New severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and waning vaccine efficacy led to the administration of booster doses. Healthcare workers (HCWs) are vulnerable to contract the infection, and vaccination hesitancy in this group may have an impact on vaccine uptake among the general public. Aims: This study aimed to (1) assess the prevalence of self-reported adverse effects (AEs) after the first booster dose vaccine, (2) evaluate the AEs between the homologous and heterologous booster vaccines, and (3) evaluate the willingness to receive a hypothetical yearly booster dose. Materials and Methods: An online, cross-sectional, self-administered, structured questionnaire was distributed to members of the health sciences faculties (HSFs), XXXX University, Malaysia. Convenience sampling was adopted, and descriptive statistics was used to interpret the results. Results: About 67.1% of participants experienced systemic or local AEs. The common AEs were pain at the site of injection (60.2%), fatigue (45.7%), headache (31.6%), and fever (24.7%). About 64% of our participants believed that the booster dose provided extra immunity against the coronavirus disease 2019 (COVID-19) infection and 57.7% of participants expressed concern over the "mix-match" of vaccination. About 78% of the participants were keen to receive the hypothetical yearly booster dose. The severity of AEs between the booster dose and the primary dose was statistically insignificant (P < 0.159). Conclusion: Booster vaccination AEs were similar to the primary dose. However, a higher severity of AEs occurring in heterologous vaccine receivers was noted in our study.

16.
Nanomaterials (Basel) ; 14(11)2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38869572

RESUMEN

The alkaline oxygen evolution reaction (OER) remains a bottleneck in green hydrogen production owing to its slow reaction kinetics and low catalytic efficiencies of earth abundant electrocatalysts in the alkaline OER reaction. This study investigates the OER performance of hierarchically porous cobalt electrocatalysts synthesized using the dynamic hydrogen bubble templating (DHBT) method. Characterization studies revealed that electrocatalysts synthesized under optimized conditions using the DHBT method consisted of cobalt nanosheets, and hierarchical porosity with macropores distributed in a honeycomb network and mesopores distributed between cobalt nanosheets. Moreover, X-ray photoelectron spectroscopy studies revealed the presence of Co(OH)2 as the predominant surface cobalt species while Raman studies revealed the presence of the cubic Co3O4 phase in the synthesized electrocatalysts. The best performing electrocatalyst required only 360 mV of overpotential to initiate a current density of 10 mA cm-2, exhibited a Tafel slope of 37 mV dec-1, and stable OER activity over 24 h. The DHBT method offers a facile, low cost and rapid synthesis approach for preparation for highly efficient cobalt electrocatalysts.

17.
Sci Total Environ ; 942: 173780, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-38844230

RESUMEN

Arctic regions are extremely sensitive to global warming. Aerosols are one of the most important short-lived climate-forcing agents affecting the Arctic climate. The present study examines the summertime chemical characteristics and potential sources of various organic and inorganic aerosols at a Norwegian Arctic site, Ny-Ålesund (79°N). The results show that organic matter (OM) accounts for 60 % of the total PM10 mass, followed by sulfate (SO42-). Water-soluble organic carbon (WSOC) contributes 62 % of OC. Photochemical processes involving diverse anthropogenic and biogenic precursor compounds are identified as the major sources of WSOC, while water-insoluble organic carbon (WIOC) aerosols are predominantly linked to primary marine emissions. Despite being a remote pristine site, the aerosols show a sign of chemical aging, evidenced by a significant chloride depletion, which was about 82 % on average during the study period. Nitrogen-containing aerosols are likely stemming from migratory seabird colonies and local dust sources around the sampling site. While biogenic, crustal, and sea salt-derived SO42- account for 37%, 8%, and 5% respectively, the remaining 50% is attributed to anthropogenic SO42-. Through chemical tracers, Pearson correlation coefficient matrix, and Hierarchical Cluster Analysis (HCA), the present study identifies soil biota (terrestrial biogenic) and marine emissions, along with their photochemical oxidation processes, as potential sources of Arctic aerosols during summer, while biomass burning and combustion-related sources have a minor contribution. The chemical closure of hygroscopicity highlights that while organics predominantly control aerosol hygroscopicity in the Arctic summer, specific inorganic components like (NH4)2SO4 can significantly increase it on certain days, affecting aerosol-cloud interactions and climate processes over the Arctic during summer. The present study highlights the high abundance of organics and their vital role in the Arctic climate during summer when natural aerosols are conquered.

18.
Biomed Pharmacother ; 176: 116921, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38870628

RESUMEN

Pulp therapy has been emerged as a one of the efficient therapies in the field of endodontics. Among different types of new endodontic materials, pulpotec has been materialized as a recognized material for vital pulp therapy. However, its efficacy has been challenged due to lack of information about its cellular biocompatibility. This study evaluates the mechanistic biocompatibility of pulpotec cement with macrophage cells (RAW 264.7) at cellular and molecular level. The biocompatibility was evaluated using experimental and computational techniques like MTT assay, oxidative stress analysis and apoptosis analysis through flow cytometry and fluorescent microscopy. The results showed concentration-dependent cytotoxicity of pulpotec cement extract to RAW 264.7 cells with an LC 50 of X/10-X/20. The computational analysis depicted the molecular interaction of pulpotec cement extract components with metabolic proteins like Sod1 and p53. The study revealed the effects of Pulpotec cement's extract, showing a concentration-dependent induction of oxidative stress and apoptosis. These effects were due to influential structural and functional abnormalities in the Sod1 and p53 proteins, caused by their molecular interaction with internalized components of Pulpotec cement. The study provided a detailed view on the utility of Pulpotec in endodontic applications, highlighting its biomedical aspects.


Asunto(s)
Apoptosis , Materiales Biocompatibles , Macrófagos , Estrés Oxidativo , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Ratones , Animales , Células RAW 264.7 , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Materiales Biocompatibles/farmacología , Ensayo de Materiales , Supervivencia Celular/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismo , Cementos Dentales/farmacología , Cementos Dentales/química , Superóxido Dismutasa-1/metabolismo
19.
ACS Appl Mater Interfaces ; 16(25): 32748-32761, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38861705

RESUMEN

Layer-by-layer (LbL) self-assembly of oppositely charged polyelectrolytes (PEs) is usually performed on a conventional ultrafiltration base substrate (negative zeta potential) by depositing a cationic PE as a first layer. Herein, we report the facile and fast formation of high performance molecular selective membrane by the nonelectrostatic adsorption of anionic PE on the polyvinylidene fluoride (PVDF, zeta potential -17 mV) substrate followed by the electrostatic LbL assembly. Loose nanofiltration membranes have been prepared via both concentration-polarization (CP-LbL, under applied pressure) driven and conventional (C-LbL, dipping) LbL self-assembly. When the first layer is poly(styrene sodium) sulfonic acid, the LbL assembled membrane contains free -SO3- groups and exhibits higher rejection of Na2SO4 and lower rejection of MgCl2. The reversal of salt rejection occurs when the first layer is quaternized polyvinyl imidazole (PVIm-Me). The membrane (five layers) prepared by first depositing PStSO3Na shows higher rejection of several dyes (97.9 to >99.9%), higher NaCl to dye separation factor (52-1800), and higher dye antifouling performance as compared to the membrane prepared by first depositing PVIm-Me (97.5-99.5% dye rejection, separation factor ∼40-200). However, the C-LbL membrane requires a longer time of self-assembly or higher PE concentration to reach a performance close to the CP-LbL membranes. The membranes exhibit excellent pressure, pH (3-12), and salt (60 g L-1) stability. This work provides an insight for the construction of low fouling and high-performance membranes for the fractionation of dye and salt based on the LbL self-assembly sequence.

20.
Adv Mater ; : e2402156, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38869191

RESUMEN

Producing green hydrogen in a cost-competitive manner via water electrolysis will make the long-held dream of hydrogen economy a reality. Although platinum (Pt)-based catalysts show good performance toward hydrogen evolution reaction (HER), the high cost and scarce abundance challenge their economic viability and sustainability. Here, a non-Pt, high-performance electrocatalyst for HER achieved by engineering high fractions of stacking fault (SF) defects for MoNi4/MoO2 nanosheets (d-MoNi) through a combined chemical and thermal reduction strategy is shown. The d-MoNi catalyst offers ultralow overpotentials of 78 and 121 mV for HER at current densities of 500 and 1000 mA cm-2 in 1 M KOH, respectively. The defect-rich d-MoNi exhibits four times higher turnover frequency than the benchmark 20% Pt/C, together with its excellent durability (> 100 h), making it one of the best-performing non-Pt catalysts for HER. The experimental and theoretical results reveal that the abundant SFs in d-MoNi induce a compressive strain, decreasing the proton adsorption energy and promoting the associated combination of *H into hydrogen and molecular hydrogen desorption, enhancing the HER performance. This work provides a new synthetic route to engineer defective metal and metal alloy electrocatalysts for emerging electrochemical energy conversion and storage applications.

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