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1.
Small ; : e2401972, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38770749

RESUMEN

Due to the chemical stability of graphene, synthesis of carboxylated graphene still remains challenging during the electrochemical exfoliation of graphite. In this work, a spatially confined radical addition reaction which occurs in the sub-nanometer scaled interlayers of the expanded graphene sheets for the electrochemical synthesis of highly stable carboxylated graphene is reported. Here, formate anions act as both intercalation ions and co-reactant acid for the confinement of electro-generated carboxylic radical (●COOH) in the sub-nanometer scaled interlayers, which facilitates the radical addition reaction on graphene sheets. The controllable carboxylation of graphene is realized by tuning the concentration of formate anions in the electrolyte solution. The high crystallinity of the obtained product indicates the occurrence of spatially confined ●COOH addition reaction between the sub-nanometer interlayers of expanded graphite. In addition, the carboxylated graphene have been used for water desalination and hydrogen/oxygen reduction reaction. Therefore, this work provides a new method for the in situ preparation of functionalized graphene through the electrolysis and its applications in water desalination and hydrogen/oxygen reduction reactions.

2.
Langmuir ; 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38738776

RESUMEN

Layered transition metal oxides are commonly used as the cathode materials in sodium-ion batteries due to their low cost and easy manufacturing. However, the application is hindered by poor rate performance and complex phase transitions. To address these challenges, a new seven-component high-entropy layered oxide cathode material, O3-NaNi0.25Fe0.15Mn0.3Ti0.1Sn0.05Co0.05Li0.1O2 (HEO) has been developed. The entropy stabilization effect plays a crucial role in improving the performance of electrochemical systems and the stability of structures. The HEO exhibits a specific discharge capacity of 154.1 mA h g-1 at 0.1 C and 94.5 mA h g-1 at 7 C. In-situ and ex-situ XRD results demonstrate that the HEO effectively retards complex phase transitions. This work provides a high-entropy design for the storage materials with a high energy density. Meanwhile, it eliminates industry doubts about the performance of sodium ion layered oxide cathode materials.

3.
J Cancer Res Clin Oncol ; 150(5): 242, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38717639

RESUMEN

BACKGROUND: Drug resistance is an important constraint on clinical outcomes in advanced cancers. LAMP2A is a limiting protein in molecular chaperone-mediated autophagy. This study was aimed to explore LAMP2A function in cisplatin (cis-diamminedichloroplatinum, DDP) resistance colorectal cancer (CRC) to seek new ideas for CRC clinical treatment. METHODS: In this study, LAMP2A expression was analyzed by molecular experimental techniques,such as qRT-PCR and western blot. Then, LAMP2A in cells was interfered by cell transfection experiments. Subsequently, the function of LAMP2A on proliferation, migration, invasion, DDP sensitivity, and autophagy of CRC/DDP cells were further investigated by a series of experiments, such as CCK-8, transwell, and western blot. RESULTS: We revealed that LAMP2A was clearly augmented in DDP-resistant CRC and was related to poor patient prognosis. Functionally, LAMP2A insertion remarkably CRC/DDP proliferation, migration, invasion ability and DDP resistance by strengthen autophagy. In contrast, LAMP2A knockdown limited the proliferation, migration, and invasion while heightened cellular sensitivity to DDP by restraining autophagy in CRC/DDP cells. Furthermore, LAMP2A silencing was able to curb tumor formation and enhance sensitivity to DDP in vivo. CONCLUSION: In summary, LAMP2A boosted malignant progression and DDP resistance in CRC/DDP cells through mediating autophagy. Clarifying LAMP2A function in DDP resistance is promising to seek cancer therapies biomarkers targeting LAMP2A activity.


Asunto(s)
Autofagia , Cisplatino , Neoplasias Colorrectales , Resistencia a Antineoplásicos , Proteína 2 de la Membrana Asociada a los Lisosomas , Humanos , Cisplatino/farmacología , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Autofagia/efectos de los fármacos , Proteína 2 de la Membrana Asociada a los Lisosomas/metabolismo , Proteína 2 de la Membrana Asociada a los Lisosomas/genética , Animales , Ratones , Proliferación Celular , Antineoplásicos/farmacología , Ratones Desnudos , Movimiento Celular , Línea Celular Tumoral , Ensayos Antitumor por Modelo de Xenoinjerto , Femenino , Masculino , Ratones Endogámicos BALB C , Pronóstico
4.
Res Sq ; 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38562782

RESUMEN

Balance of bone and marrow fat formation is critical for bone homeostasis. The imbalance of bone homeostasis will cause various bone diseases, such as osteoporosis. However, the precise mechanisms governing osteoporotic bone loss and marrow adipose tissue (MAT) accumulation remain poorly understood. By analysis of publicly available databases from bone samples of osteoporosis patients, we found that the expression of intraflagellar transport 20 (IFT20) and WW domain containing transcription regulator 1 (WWTR1) were significantly downregulated in osteoblast lineage cells. Additionally, we found that double deletions of IFT20 and WWTR1 in osteoblasts resulted in a significant accumulation of MAT and bone loss. Moreover, IFT20 and WWTR1 deficiency in osteoblasts exacerbated bone-fat imbalance in ovariectomy (OVX)- and high-fat-diet (HFD)-induced osteoporosis mouse models. Mechanistically, we found that deletions of IFT20 and WWTR1 in osteoblasts synergistically inhibited osteogenesis and promoted adipogenesis and osteoclastogenesis. We also found that IFT20 interacted with TGF-ß receptor type II (TßRII) to enhance TßRII stability by blocking c-Cbl-mediated ubiquitination and degradation of TßRII. WWTR1 transcriptionally upregulated TßRII expression by directly binding its promoter. These findings indicate that targeting IFT20/WWTR1 may be a potential therapeutic strategy for the treatment of osteoporosis.

6.
Inflammopharmacology ; 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38642222

RESUMEN

BACKGROUND: This work evaluated the effects of proton pump inhibitors (PPIs) on cardiovascular events (CVEs) and inflammatory factors in patients with upper gastrointestinal bleeding (UGIB) undergoing dual antiplatelet therapy (DAPT) after percutaneous coronary intervention. Clinical data from these patients were analysis, intending to provide relevant theoretical evidence for clinical practice. MATERIALS AND METHODS: Data of 166 patients who underwent percutaneous coronary intervention and developed UGIB while on DAPT at The First People' Hospital of Linping District from April 2021 to April 2023 were retrospectively analyzed. The patients were rolled into two groups: those who received PPI treatment and those who did not, namely, PPI and non-PPI group, respectively. Furthermore, occurrence of CVEs and the levels of inflammatory factors of patients in all groups were statistically analyzed. RESULTS: In patients with UGIB, melena is a common presentation. The incidence of CVE in the PPI group showed no statistically significant difference compared to the control group, and there was no significant variance observed in the distribution of CVE incidence among different PPIs. However, levels of C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α) were significantly lower in the PPI group compared to the non-PPI group (P < 0.05). CONCLUSION: Melena was the most frequent clinical manifestation in UGIB patients. The use of PPIs did not increase the risk of CVEs, and different PPI drugs did not affect the occurrence of CVEs. Furthermore, PPIs lowered CRP and TNF-α levels in serum of these patients.

7.
Infect Drug Resist ; 17: 1397-1405, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38628239

RESUMEN

Objective: To investigate the value of metagenomic Next-Generation Sequencing (mNGS) in diagnosing Pneumocystis jirovecii pneumonia (PJP) in non-human immunodeficiency virus (HIV)-infected patients. Methods: In this retrospective study, non-HIV-infected patients with PJP and those diagnosed with non-PJP from August 2022 to December 2024 were selected as subjects. The presence of Pneumocystis jirovecii (PJ) and other co-pathogens in bronchoalveolar lavage fluid (BALF) was analyzed, and the diagnostic efficacy of NGS, polymerase chain reaction (PCR) and serum 1,3-ß-D-glucan (BDG) in PJP was compared with the reference standard of clinical compound diagnosis. Results: Eighty-nine non-HIV-infected patients were recruited, with dyspnea as the primary symptom (69.66%) and solid malignant tumor as the most common underlying disease (20.22%). Taking clinical compound diagnosis as the reference standard, the sensitivity, specificity, negative predictive value and positive predictive value of mNGS were higher than those detected by PCR and serum BDG. Among 42 non-HIV-infected patients with PJP who underwent mNGS and conventional pathogen detection of BALF, 6 had simple PJ infection and 36 had combined PJ infection. The detection rate of mNGS in mixed infections was significantly higher than that of conventional pathogen detection (85.71 vs 61.70%, P = 0.012). A total of 127 pathogens were detected in BALF using mNGS, among which fungi had the highest detection rate (46.46%). The fungi, viruses and bacteria detected were mainly Pneumocystis jirovecii, human gammaherpesvirus 4 and Acinetobacter baumannii. Conclusion: mNGS is highly effective in diagnosing non-HIV-infected patients with PJP and exhibits ideal performance in the detection of co-pathogens. In addition, it has certain value for clinical diagnosis and guidance of targeted anti-infective drug treatment.

8.
Biomedicines ; 12(4)2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38672192

RESUMEN

In recent years, the utilization of minimally invasive surfactant therapy (MIST) and Non-invasive ventilation (NIV) as the primary respiratory assistance has become increasingly prevalent among preterm infants with neonatal respiratory distress syndrome (RDS). This study aims to compare the outcomes between MIST administered with nasal continuous positive airway pressure (NCPAP) versus nasal intermittent positive pressure ventilation (NIPPV), with the objective of exploring the respiratory therapeutic benefits of these two approaches. This retrospective study collected data from the neonatal intensive care unit of Kaohsiung Medical University Hospital spanning from January 2016 to June 2021. Infants were divided into two groups based on the type of NIV utilized. The NCPAP group comprised 32 infants, while the NIPPV group comprised 22 infants. Statistical analysis revealed significant differences: the NIPPV group had a smaller gestational age, lower birth weight, higher proportion of female infants, and earlier initiation of MIST. Additionally, the NIPPV group exhibited higher incidence rates of retinopathy of prematurity, longer respiratory support duration, prolonged hospitalization, and mortality. However, upon adjustment, these differences were not statistically significant. Analysis of venous blood gas and respiratory parameter changes indicated that both the NCPAP and NIPPV groups experienced improvements in oxygenation and ventilation following MIST.

9.
Ecotoxicol Environ Saf ; 277: 116365, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38657452

RESUMEN

Microglia, the resident immune cells of the central nervous system (CNS), play a dual role in neurotoxicity by releasing the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome and brain-derived neurotrophic factor (BDNF) in response to environmental stress. Suppression of BDNF is implicated in learning and memory impairment induced by exposure to manganese (Mn) or lead (Pb) individually. Methyl CpG Binding Protein 2 (MeCp2) and its phosphorylation status are related to BDNF suppression. Protein phosphatase2A (PP2A), a member of the serine/threonine phosphatases family, dephosphorylates substrates based on the methylation state of its catalytic C subunit (PP2Ac). However, the specific impairment patterns and molecular mechanisms resulting from co-exposure to Mn and Pb remain unclear. Therefore, the purpose of this study was to explore the effects of Mn and Pb exposure, alone and in combination, on inducing neurotoxicity in the hippocampus of mice and BV2 cells, and to determine whether simultaneous exposure to both metals exacerbate their toxicity. Our findings reveal that co-exposure to Mn and Pb leads to severe learning and memory impairment in mice, which correlates with the accumulation of metals in the hippocampus and synergistic suppression of BDNF. This suppression is accompanied by up-regulation of the epigenetic repressor MeCp2 and its phosphorylation status, as well as demethylation of PP2Ac. Furthermore, inhibition of PP2Ac demethylation using ABL127, an inhibitor for its protein phosphatase methylesterase1 (PME1), or knockdown of MeCp2 via siRNA transfection in vitro effectively increases BDNF expression and mitigates BV2 cell damage induced by Mn and Pb co-exposure. We also observe abnormal activation of microglia characterized by enhanced release of the NLRP3 inflammasome, Casepase-1 and pro-inflammatory cytokines IL-1ß, in the hippocampus of mice and BV2 cells. In summary, our experiments demonstrate that simultaneous exposure to Mn and Pb results in more severe hippocampus-dependent learning and memory impairment, which is attributed to epigenetic suppression of BDNF mediated by PP2A regulation.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo , Epigénesis Genética , Hipocampo , Plomo , Manganeso , Trastornos de la Memoria , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ratones , Epigénesis Genética/efectos de los fármacos , Manganeso/toxicidad , Plomo/toxicidad , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Trastornos de la Memoria/inducido químicamente , Masculino , Ratones Endogámicos C57BL , Microglía/efectos de los fármacos , Proteína 2 de Unión a Metil-CpG/metabolismo , Proteína 2 de Unión a Metil-CpG/genética , Proteína Fosfatasa 2/metabolismo , Aprendizaje/efectos de los fármacos
10.
Langmuir ; 40(18): 9556-9562, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38666374

RESUMEN

Direct regeneration has gained much attention in LiFePO4 battery recycling due to its simplicity, ecofriendliness, and cost savings. However, the excess carbon residues from binder decomposition, conductive carbon, and coated carbon in spent LiFePO4 impair electrochemical performance of direct regenerated LiFePO4. Herein, we report a preoxidation and prilling collaborative doping strategy to restore spent LiFePO4 by direct regeneration. The excess carbon is effectively removed by preoxidation. At the same time, prilling not only reduces the size of the primary particles and shortens the diffusion distance of Li+ but also improves the tap density of the regenerated materials. Besides, the Li+ transmission of the regenerated LiFePO4 is further improved by Ti4+ doping. Compared with commercial LiFePO4, it has excellent low-temperature performance. The collaborative strategy provides a new insight into regenerating high-performance spent LiFePO4.

11.
Int J Biol Macromol ; 265(Pt 2): 130988, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38518942

RESUMEN

Codonopsis pilosula is a famous edible and medicinal plants, in which polysaccharides are recognized as one of the important active ingredients. A neutral polysaccharide (CPP-1) was purified from C. pilosula. The structure was characterized by HPSEC-MALLS-RID, UV, FT-IR, GC-MS, methylation analysis, and NMR. The results showed that CPP-1 was a homogeneous pure polysaccharide, mainly containing fructose and glucose, and a small amount of arabinose. Methylation analysis showed that CPP-1 composed of →1)-Fruf-(2→, Fruf-(1→ and Glcp-(1→ residues. Combined the NMR results the structure of CPP-1 was confirmed as α-D-Glcp-(1 â†’ [2)-ß-D-Fruf-(1 â†’ 2)-ß-D-Fruf-(1]26 â†’ 2)-ß-D-Fruf with the molecular weight of 4.890 × 103 Da. The model of AML12 hepatocyte fat damage was established in vitro. The results showed that CPP-1 could increase the activity of SOD and CAT antioxidant enzymes and reduce the content of MDA, thus protecting cells from oxidative damage. Subsequently, the liver protective effect of CPP-1 was studied in the mouse model of nonalcoholic fatty liver disease (NAFLD) induced by the high-fat diet. The results showed that CPP-1 significantly reduced the body weight, liver index, and body fat index of NAFLD mice, and significantly improved liver function. Therefore, CPP-1 should be a potential candidate for the treatment of NAFLD.


Asunto(s)
Codonopsis , Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Codonopsis/química , Espectroscopía Infrarroja por Transformada de Fourier , Polisacáridos/farmacología , Polisacáridos/uso terapéutico , Polisacáridos/química , Antioxidantes/farmacología
12.
Children (Basel) ; 11(3)2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38539386

RESUMEN

Nasal continuous positive airway pressure (NCPAP) is extensively used for preterm infants experiencing respiratory distress syndrome (RDS). Weaning from NCPAP includes direct weaning or gradually extending room air exposure. However, a high-flow nasal cannula (HFNC) is an alternative weaning method. Therefore, this study evaluated the clinical outcomes of HFNC and progressively increasing room air duration as weaning strategies. This study enrolled 46 preterm infants with RDS receiving NCPAP support who underwent the cyclic use of NCPAP and HFNC weaning protocol as the HFNC group; a retrospective analysis included 87 preterm infants weaned from NCPAP by gradually extending room air duration as the room air group. Differences in clinical conditions, complications, and short-term outcomes between the weaning methods were compared. The mean post-menstrual age at initiating NCPAP weaning was lower in the room air group than in the HFNC group (mean ± SD, 35.2 ± 2.3 weeks vs. 33.2 ± 2.5 weeks, p < 0.001). Hospital stay duration and total respiratory therapy days were longer in the HFNC group (96 ± 38 days and 80 ± 37 days, respectively) than in the room air group (78 ± 28 days and 56 ± 25 days, respectively), with p-values of 0.006 and <0.001. In conclusion, employing HFNC for weaning from NCPAP resulted in longer hospital admissions and respiratory therapy days than the room air method. However, further studies with a larger sample size are warranted for a more comprehensive evaluation, given the limited number of enrolled patients.

13.
Heliyon ; 10(2): e24795, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38304798

RESUMEN

Most clinically non-functioning pituitary tumour arise from gonadotroph cells. However, clinically functional pituitary gonadotroph adenoma is rare. Here we report a female case who presented with menstrual disturbances, however further workup demonstrated a pituitary microadenoma with elevated FSH and oestradiol level. Transsphenoidal resection was performed and the surgical histopathology confirmed pituitary gonadotroph adenoma. Postoperatively, improvement in both symptoms and hormonal profile were observed. Interestingly, the initially enlarged and polycystic ovaries became within normal range around eight months after the surgery. We suggest functional gonadotroph adenoma should be considered in the presence of gynaecological disorder with persistently elevated oestradiol and FSH levels.

14.
Hortic Res ; 11(2): uhad273, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38333729

RESUMEN

In the era of rapid advancements in high-throughput omics technologies, the visualization of diverse data types with varying orders of magnitude presents a pressing challenge. To bridge this gap, we introduce DataColor, an all-encompassing software solution meticulously crafted to address this challenge. Our aim is to empower users with the ability to handle a wide array of data types through an assortment of tools, while simultaneously streamlining parameter selection for rapid insights and detailed enhancements. DataColor stands as a robust toolkit, encompassing 23 distinct tools coupled with over 600 parameters. The defining characteristic of this toolkit is its adept utilization of the color spectrum, allowing for the representation of data spanning diverse types and magnitudes. Through the integration of advanced algorithms encompassing data clustering, normalization, squarified layouts, and customizable parameters, DataColor unveils an abundance of insights that lay hidden within the intricate relationships embedded in the data. Whether you find yourself navigating the analysis of expansive datasets or embarking on the quest to visualize intricate patterns, DataColor stands as the comprehensive and potent solution. We extend the availability of DataColor to all users at no cost, accessible through the following link: https://github.com/frankgenome/DataColor.

15.
BMC Public Health ; 24(1): 448, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38347551

RESUMEN

Whether a family history of diabetes (FHD) and exposure to perfluoroalkyl acids (PFAAs) are correlated with an increased risk of developing arthritis remains unclear. This cross-sectional study was conducted to explore the correlations between FHD or exposure to PFAAs and arthritis as well as their interaction using the National Health and Nutrition Examination Survey (NHANES). In total, 6,194 participants aged ≥ 20 years from the 2011-2018 NHANES were enrolled. PFAAs are a cluster of synthetic chemicals, including perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid (PFDA) and perfluorohexane sulfonic acid (PFHxS). FHD was evaluated using self-reported questionnaires. Arthritis was classified into three types, rheumatoid arthritis (RA), osteoarthritis (OA), and others, which were diagnosed using questionnaires. Generalized linear models (GLMs) were used to test the correlation between FHD and arthritis. To examine the joint effects of PFAAs and FHD on arthritis, interaction terms were applied in the GLM. Arthritis incidence was 26.7% among all participants. FHD was associated with both RA [OR = 1.70 (95% CI: 1.15-2.50)] and other types of arthritis [OR = 1.62 (95% CI: 1.21-2.16)]. However, the relationship between FHD and OA was not significant after adjustment (P = 0.18). Interaction outcomes indicated that higher PFDA levels increased the association between FHD and arthritis. FHD is associated with an increased incidence of arthritis, which may be increased by PFDA. Given the heavy burden of arthritis, preventive measures for arthritis and reduction of PFAAs exposure for patients with FHD are required.


Asunto(s)
Artritis , Ácidos Decanoicos , Diabetes Mellitus , Contaminantes Ambientales , Fluorocarburos , Humanos , Encuestas Nutricionales , Estudios Transversales , Artritis/epidemiología , Artritis/genética
16.
J Thorac Dis ; 16(1): 51-64, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38410615

RESUMEN

Background: Transthoracic echocardiography (TTE) is recommended as the most important noninvasive screening tool for the diagnosis of pulmonary hypertension (PH), sonographers usually measure the volume of regurgitant flow rather than evaluating the spectral quality, so physicians will determine whether the ultrasound measurements of pulmonary arterial systolic pressure (US-PASP) are reliable based on the volume of tricuspid regurgitation (TR). Therefore, for the first time, we grade the quality of TR spectrum (TRS) based on its integrity and clarity, aiming to assess clinical application value of different tricuspid regurgitant spectrum quality grades (TR-SQG), and investigate whether the accuracy of US-PASP is more trustworthy than TR. Methods: We retrospectively analyzed 108 patients with chronic thromboembolic PH (CTEPH) to compare the correlation and agreement between US-PASP and right heart catheterization measurements of PASP (RHC-PASP). TR area (TRA) and TRS were measured in each patient, and TR-SQG was performed. Results: The correlation coefficients between US-PASP and RHC-PASP were r=0.622 (P<0.001), r=0.754 (P<0.001), r=0.595 (P<0.001) in mild, moderate, severe TR, and r=0.301 (P=0.135), r=0.747 (P<0.001), r=0.739 (P<0.001), r=0.828 (P<0.001) in TR-SQG I-IV, respectively. Bland-Altman analysis revealed the mean biases of 5.05, 3.06, 7.62 mmHg in mild, moderate, severe TR, and -16.47, -8.07, 1.82, 6.09 mmHg in TR-SQG I-IV, respectively. In mild TR with the TR-SQG III and IV, the correlation coefficients between US-PASP and RHC-PASP were r=0.779 (P<0.001), intraclass correlation coefficient (ICC) =0.774, paired t-test P=0.160, respectively; and the consistency was significantly higher than that of mild TR without considering TR-SQG. In moderate TR with the TR-SQG III and IV, the r=0.749, ICC =0.746, paired t-test P=0.298 between US-PASP and RHC-PASP. Conclusions: The US-PASP with TR-SQG III or IV is trustworthy, and its accuracy and consistency are better than those predicted by the traditional severity of TR. The establishment of the ultrasound evaluation system of TR-SQG helps clinicians to judge whether the US-PASP is accurate, credible, and reliable.

17.
ACS Nano ; 18(9): 6936-6945, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38271620

RESUMEN

Multiterminal memtransistors made from two-dimensional (2D) materials have garnered increasing attention in the pursuit of low-power heterosynaptic neuromorphic circuits. However, existing 2D memtransistors tend to necessitate high set voltages (>1 V) or feature defective channels, posing concerns regarding material integrity and intrinsic properties. Herein, we present a monocrystalline monolayer MoS2 memtransistor designed for operation within submicron regimes. Under reverse drain bias sweeps, our experiments reveal memristive behavior within the device, further controllable through modulation of the gate terminal. This controllability facilitates the consistent manifestation of multistate memory effects. Notably, the memtransistor behavior becomes more significant as the channel length diminishes, particularly with channel lengths below 1.6 µm, showcasing an increase in the switching ratio alongside a decrease in the set voltage with the decreasing channel length. Our optimized memtransistor demonstrates the ability to exhibit individual resistance states spanning 5 orders of magnitude, with switching drain voltages of approximately 0.05 V. To elucidate these findings, we investigate hot carrier effects and their interplay with oxide traps within the HfO2 dielectric. This work highlights the importance of memtransisor behavior in highly scaled 2D transistors, particularly those featuring low contact resistances. This understanding holds the potential to tailor memory characteristics essential for the development of energy-efficient neuromorphic devices.

18.
Int J Biol Macromol ; 259(Pt 1): 129223, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38185309

RESUMEN

To obtain a flexible composite electrode material with excellent electrochemical performance, chitosan (CS)/graphene oxide (GO) composite pretreated from microwave hydrothermal is adopted as the carbon substrate, and MnO2 active material is uniformly deposited on their surface through anodic electrodeposition. In this composite system, CS penetrates into graphene sheets as small molecule units, forming NH-C=O groups with GO via dehydration condensation, which effectively inhibits the stacking of GO and improves the specific surface area, conductivity, as well as the wettability of the carbon support. MnO2 bonding with heteroatom N from CS enables high active material loadings and forms stable three-dimensional network structure, facilitating the enhanced electrochemical performance. Results indicate that increasing depositing MnO2 amount leads to more defective structures of the composite, which promotes their electrochemical performance when used as electrode material. The area specific capacitance of the optimal composite reaches 3553.74 mF/cm2 at 5 mA/cm2 in 1 M Na2SO4 electrolyte. Kinetic analysis shows the energy storage process is capacitance-dominated, with the redox reactions of MnO2 being the main contributor. The prepared asymmetric solid supercapacitor delivers an energy density high up to 0.585 mWh/cm2 at power density of 3000 mW/cm2, and their excellent flexibility makes them promising candidates as flexible sensor.


Asunto(s)
Quitosano , Grafito , Cinética , Compuestos de Manganeso , Óxidos , Carbono
19.
J Colloid Interface Sci ; 657: 559-566, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38071805

RESUMEN

The rational design of low-cost, efficient, and stable heterojunction catalysts for pH-universal hydrogen evolution is attracting increasing attention towards a sustainable hydrogen economy. Herein, a sequential spatial restriction-pyrolysis route is developed to confine Mott-Schottky-type Co-Co2P heterojunctions embedded in the one-dimensional (1D) carbon nanotube-modified three-dimensional (3D) N,P dual-doped carbon matrix (Co-Co2P@CNT//CM). The synergistic effect between the abundant Mott-Schottky heterointerfaces and the 1D/3D dual carbon confinement system enables fully exposed active sites and facilitated charge transfer dynamics, thus triggering favorable electronic structures of Co-Co2P@CNT//CM. As a result, Co-Co2P@CNT//CM heterojunctions exhibit excellent pH-universal hydrogen evolution reaction (HER) performance with overpotentials of 142, 205, and 262 mV at 10 mA cm-2 in 0.5 M H2SO4, 1.0 M KOH, and 1.0 M phosphate buffer saline (PBS), respectively. The theoretical results demonstrated that the Mott-Schottky effect can induce an oriented interfacial charge exchange between Co and Co2P. This can lower the reactive kinetic barrier and endow Co-Co2P@CNT//CM with ideal hydrogen adsorption free energy, which efficiently drives the production of H2 from electrolytic water.

20.
Small ; : e2306369, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-38054776

RESUMEN

Cobalt sulfide is deemed a promising anode material, owing to its high theoretical capacity (630 mAh g-1 ). Due to its low conductivity, fast energy decay, and the huge volume change during the lithiation process limits its practical application. In this work, a simple and large-scale method are developed to prepare Co1-x S nanoparticles embedding in N-doped carbon/graphene (CSCG). At a current density of 0.2 C, the reversible discharge capacity of CSCG maintains 937 mAh g-1 after 200 cycles. The discharge capacity of CSCG maintains at 596 mAh g-1 after 500 cycles at the high current density of 2.0 C. The excellent performance of CSCG is due to its unique structural features. The addition of rGO buffered volume changes while preventing Co1-x S from crushing/aggregating during the cycle, resulting in multiplier charge-discharge and long cycle life. The N-doped carbon provides a simple and easy way to achieve excellent performance in practical applications. Combined with density functional theory calculation, the presence of Co-vacancies(Co1-x ) increases more active site. Moreover, N-doping carbon is beneficial to the improve adsorption energy. This work presents a simple and effective structural engineering strategy and also provides a new idea to improve the performance of Li-ion batteries.

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