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1.
J Am Chem Soc ; 2024 May 21.
Article in English | MEDLINE | ID: mdl-38771765

ABSTRACT

Single-atom catalysts (SACs) have been widely investigated and have emerged as a transformative approach in electrocatalysis. Despite their clear structure, the origin of their exceptional activity remains elusive. Herein, we elucidate a common phenomenon of the hybridization state transition of metal centers, which is responsible for the activity origin across various SACs for different reactions. Focusing on N-doped carbon-supported Ni SAC (NiN4 SAC) for CO2 reduction reaction (CO2RR), our comprehensive computations successfully clarify the hybridization state transition under working conditions and its relation with the activity. This transition, triggered by the reaction intermediates and applied potential, converts the Ni center from the inert dsp2 hybridization state to the active d2sp3 hybridization state. Importantly, the calculated activity and selectivity of the CO2RR over the d2sp3-hybridized Ni center are consistent with the experimental results, offering strong support for the proposed hypothesis. This work suggests a universal principle of electronic structure evolution in SACs that could revolutionize catalyst design, which also introduces a new paradigm for manipulating electronic states to enhance catalytic performance, with implications for various reactions and catalyst platforms.

2.
Med Phys ; 2024 May 21.
Article in English | MEDLINE | ID: mdl-38772044

ABSTRACT

BACKGROUND: Determining the optimal energy layer (EL) for each field, under considering both dose constraints and delivery efficiency, is crucial to promoting the development of proton arc therapy (PAT) technology. PURPOSE: This study aimed to explore the feasibility and potential clinical benefits of utilizing machine learning (ML) technique to automatically select EL for each field in PAT plans of lung cancer. METHODS: Proton Bragg peak position (BPP) was employed to characterize EL. The ground truth BPPs for each field were determined using the modified ELO-SPAT framework. Features in geometric, water-equivalent thicknesses (WET) and beamlet were defined and extracted. By analyzing the relationship between the extracted features and ground truth, a polynomial regression model with L2-norm regularization (Ridge regression) was constructed and trained. The performance of the regression model was reported as an error between the predictions and the ground truth. Besides, the predictions were used to make PAT plans (PAT_PRED). These plans were compared with those using the ground truth BPPs (PAT_TRUTH) and the mid-WET of the target volumes (PAT_MID) in terms of relative biological effectiveness-weighted dose (RWD) distributions. One hundred ten patients with lung cancer, a total of 7920 samples, were enrolled retrospectively, with 5940 cases randomly selected as the training set and the remaining 1980 cases as the testing set. Nine patients (648 samples) were collected additionally to evaluate the regression model in terms of plan quality and robustness. RESULTS: With regard to the prediction errors, the root mean squared errors and mean absolute errors between the ML-predicted and ground truth BPPs for the testing set were 9.165 and 6.572 mm, respectively, indicating differences of approximately two to three ELs. As for plan quality, the PAT_TRUTH and PAT_PRED plans performed similarly in terms of plan robustness, target coverage and organs at risk (OARs) protection, with differences smaller than 0.5 Gy(RBE). This trend was also observed for dose conformity and uniformity. The PAT_MID plans produced the lowest robustness index and lowest doses to OARs, along with the highest heterogeneity index, indicating better protection for OARs, improved plan robustness, but compromised dose homogeneity. Additionally, for relatively small tumor sizes, the PAT_MID plan demonstrated a notably poor dose conformity index. CONCLUSIONS: Within this cohort under investigation, our study demonstrated the feasibility of using ML technique to predict ELs for each field, offering a fast (within 2 s) and memory-efficient reduced way to select ELs for PAT plan.

3.
J Am Chem Soc ; 2024 May 22.
Article in English | MEDLINE | ID: mdl-38775661

ABSTRACT

Solid electrolyte interphases (SEIs) are sought to protect high-capacity anodes, which suffer from severe volume changes and fast degradations. The previously proposed effective SEIs were of high strength yet abhesive, inducing a yolk-shell structure to decouple the rigid SEI from the anode for accommodating the volume change. Ambivalently, the interfacial void-evolved electro-chemo-mechanical vulnerabilities become inherent defects. Here, we establish a new rationale for SEIs that resilience and adhesivity are both requirements and pioneer a design of a resilient yet adhesive SEI (re-ad-SEI), integrated into a conjugated surface bilayer structure. The re-ad-SEI and its protected particles exhibit excellent stability almost free from the thickening of SEI and the particle pulverization during cycling. More promisingly, the dynamically bonded intact SEI-anode interfaces enable a high-efficiency ion transport and provide a unique mechanical confinement effect for structural integrity of anodes. The high Coulombic efficiency (>99.8%), excellent cycling stability (500 cycles), and superior rate performance have been demonstrated in microsized Si-based anodes.

4.
Small ; : e2400927, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38726949

ABSTRACT

Due to the presence of spatial barriers, persistent bacteria, and excessive inflammation in bacteria biofilm-infected wounds, current nanoplatforms cannot effectively address these issues simultaneously during the therapeutic process. Herein, a novel biomimetic photothermal nanoplatform integrating silver and polydopamine nanoparticles (Ag/PDAs) that can damage biofilms, kill bacterial persisters, and reduce inflammation for wound treatment is presented. These findings reveal that Ag/PDAs exhibit a broad-spectrum antimicrobial activity through direct damage to the bacterial membrane structure. Additionally, Ag/PDAs demonstrate a potent photothermal conversion efficiency. When combined with near-infrared (NIR) irradiation, Ag/PDAs effectively disrupt the spatial structure of biofilms and synergistically eradicate the resident bacteria. Furthermore, Ag/PDAs show remarkable anti-inflammatory properties in counteracting bacterium-induced macrophage polarization. The in vivo results confirm that the topical application of Ag/PDAs significantly suppress Staphylococcus aureus biofilm-infected wounds in murine models, concurrently facilitating wound healing. This research provides a promising avenue for the eradication of bacterial biofilms and the treatment of biofilm-infected wounds.

6.
Article in English | MEDLINE | ID: mdl-38758157

ABSTRACT

Objective: To examine the clinical efficacy of bevacizumab (BEV) combined with temozolomide (TMZ) as a treatment for patients with recurrent malignant gliomas. Methods: 50 patients with recurrent malignant gliomas treated at our hospital between January 2019 and January 2022 were enrolled and randomized to the control group and combine group using a random table method, with 25 cases in each group. The control group received TMZ and the combine group received BEV plus TMZ. The disease control rate (DCR), the quality-of-life score before and after treatment, and the median 6-month progression-free survival (PFS) rate as well as adverse reactions were recorded and compared. Results: There was a significant difference in DCR between the combine group (80%) and the control group (52%) (χ2 = 5.556, P = .018). In each of the quality-of-life scales, the scores of the combine group were significantly greater than those of the control group after treatment, and the difference was statistically significant (P < .05). In the control group, the median PFS was 16.2 weeks, and the six-month PFS was 19.8%. However, in the combine group, the median PFS was 21.9 weeks, and the six-month PFS was 43.1% (P < .05). Comparing the two groups, the rate of adverse reactions in the control group was significantly higher (44.0% vs 12.0%) (χ2 = 6.349, P = .012). Conclusion: BEV plus TMZ is remarkable in the treatment of patients with recurrent malignant gliomas. The combination treatment improves the DCR and PFS of patients and their quality of life, and does not increase adverse reactions, making it a promising approach that deserves widespread promotion and clinical application.

7.
Materials (Basel) ; 17(9)2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38730782

ABSTRACT

Bimetallic composites have a wide range of application prospects in various industries. Different bonding temperatures, as one of the influencing factors, directly affect the bonding effectiveness as well as the performance and application of the materials. Using metallurgical bonding techniques ensures a strong bond at the interface of bimetallic materials, resulting in high-quality composite pipe billets. This paper describes an Incoloy825/P110 steel bimetal composite material made by the solid-liquid composite method. By utilizing ProCAST 14.5 software for simulation and deriving theoretical formulas, an initial range of temperatures for bimetallic preparation has been tentatively determined. And this temperature range will be utilized for on-site experiments to prepare bimetallic samples. After the preparation process is completed, samples will be selected. The influence of the external mold temperature on the interface bonding of Incoloy825/P110 steel solid-liquid composite material is studied using an ultra-depth three-dimensional morphology microscope and a scanning electron microscope. Through research, the optimal preheating temperature range for the solid-liquid composite outer mold of Incoloy825/P110 bimetallic composite material has been determined. The casting temperature of the inner mold has a significant impact on the interface bonding of this bimetal composite material. As the casting temperature of the inner mold increases, the interface thickness gradually increases. At lower temperatures, the interface thickness is lower and the bonding is poorer. At higher temperatures, melting may occur, leading to coarse grains at the interface. When the temperatures of the inner and outer molds are within a certain range, a new phase appears at the interface. Indeed, it increases the strength of the interface bonding. Due to co-melting of the bimetal near the interface, element migration occurs, resulting in increased Ni and Cr content at the interface and enhanced corrosion resistance.

8.
Animals (Basel) ; 14(9)2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38731350

ABSTRACT

The rabbitfish, Siganus oramin, is a commercially important table fish in southeastern China. However, there have been few studies on its gonad development and reproduction regulation. Comparative transcriptome analysis was first performed on adult male and female gonads of S. oramin. In total, 47,070 unigenes were successfully assembled and 22,737 unigenes were successfully annotated. Through comparative transcriptome analysis of male and female gonads, a total of 6722 differentially expressed genes were successfully identified, with 3528 upregulated genes and 3154 downregulated genes in the testes. In addition, 39 differentially expressed reproduction-related genes were identified. Finally, quantitative real-time PCR was used to validate the expression levels of several differentially expressed genes. These results provide important data for further studying the function of reproduction-related genes and the molecular mechanism regulating gonad development and reproduction in S. oramin.

9.
Foods ; 13(9)2024 May 01.
Article in English | MEDLINE | ID: mdl-38731767

ABSTRACT

The diversity of alcohol beverage microorganisms is of great significance for improving the brewing process and the quality of alcohol beverage products. During the process of making alcoholic beverages, a group of microorganisms, represented by yeast and lactic acid bacteria, conducts fermentation. These microorganisms have complex synergistic or competitive relationships, and the participation of different microorganisms has a major impact on the fermentation process and the flavor and aroma of the product. Strain selection is one of the key steps. Utilizing scientific breeding technology, the relationship between strains can be managed, the composition of the alcoholic beverage microbial community can be improved, and the quality and flavor of the alcoholic beverage products can be increased. Currently, research on the microbial diversity of alcohol beverages has received extensive attention. However, the selection technology for dominant bacteria in alcohol beverages has not yet been systematically summarized. To breed better-quality alcohol beverage strains and improve the quality and characteristics of wine, this paper introduces the microbial diversity characteristics of the world's three major brewing alcohols: beer, wine, and yellow wine, as well as the breeding technologies of related strains. The application of culture selection technology in the study of microbial diversity of brewed wine was reviewed and analyzed. The strain selection technology and alcohol beverage process should be combined to explore the potential application of a diverse array of alcohol beverage strains, thereby boosting the quality and flavor of the alcohol beverage and driving the sustainable development of the alcoholic beverage industry.

10.
Chin Herb Med ; 16(2): 274-281, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38706818

ABSTRACT

Objective: Rheumatoid arthritis (RA) is a chronic inflammatory and destructive arthritis, characterized by inflammatory infiltration and bone destruction. Huangqi Guizhi Wuwu Decoction (HGWD) is traditional Chinese medicine, which has been applied in the treatment of RA in clinical. The aim of this study was to investigate the therapeutic effect of HGWD on collagen-induced arthritis (CIA) mouse model. Methods: DBA/1J female mice were used to establish the collagen-induced arthritis (CIA) model. HGWD was administered intragastrically once a day for four weeks starting on the 22nd day after the first immunization. The body weight, hind paw thickness and clinical score were measured every five days. Gait analysis, histopathological staining, enzyme-linked immunosorbent assay (ELISA), ultrasound imaging and micro-computed tomography imaging were performed to determine the effects of HGWD treatment on inflammation and bone structure in this model. Moreover, Real-time PCR and Western blot analysis were used to detect inflammatory factors mRNA and protein levels after HGWD intervention in RAW 264.7 cells. Results: HGWD attenuated symptoms of arthritis, suppressed inflammatory synovium area and the serum levels of inflammatory factors, inhibited joint space enlargement in the knee and ankle joints, reduced numbers of osteoclasts, protected bone destruction, as well as improved motor function. HGWD decreased the expression of mRNA for inflammatory factors and the protein expression levels of p-NF-кB and IL-17. Conclusion: These results suggested that HGWD suppresses inflammation, attenuates bone erosion and maintains motor function in collagen-induced arthritis mice.

11.
J Exerc Sci Fit ; 22(4): 297-304, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38706951

ABSTRACT

Background: Probiotic supplementation has a positive effect on endurance exercise performance and body composition in athletes, but the underlying mechanisms remain unclear. Gut microbiota can provide measurable markers of immune function in athletes, and microbial composition analysis may be sensitive enough to detect stress and metabolic disorders caused by exercise. Methods: Nineteen healthy active amateur marathon runners (15 male and 4 female) with a mean age of 29.11 years volunteered to participate in this double-blind controlled study. Based on the performance of the Cooper 12-min running test (CRT), the participants were allocated into two groups to receive either a probiotic formulation comprising lactobacillus acidophilus and bifidobacterium longum (n = 10) or placebo containing maltodextrin (n = 9) for five weeks. Consistency of diet and exercise was ensured throughout the experimental period. Before and after the intervention, all participants were assessed for CRT, emotional stability and gastrointestinal symptoms, gut microbiota composition, body composition and magnetic resonance imaging (MRI) indicators of skeletal muscle microcirculation. Results: Compared to before the intervention, the probiotics group showed an increase in CRT score (2.88 ± 0.57 vs 3.01 ± 0.60 km, P<0.05), significant improvement in GSRS and GIQLI (9.20 ± 4.64 vs 7.40 ± 3.24, 118.90 ± 12.30 vs 127.50 ± 9.85, P<0.05), while these indicators remained unchanged in the control group, with a significant time-group interaction effect on gastrointestinal symptoms. Additionally, some MRI metabolic cycling indicators of the thigh skeletal muscle also changed in the probiotics group (P<0.05). Regarding microbiota abundance, the probiotics group exhibited a significant increase in the abundance of beneficial bacteria and a significant decrease in the abundance of harmful bacteria post-intervention (P<0.05). Conclusion: As a sports nutritional supplement, probiotics have the potential to improve athletic performance by optimizing the balance of gut microbiota, alleviating gastrointestinal symptoms.

12.
Cornea ; 2024 May 07.
Article in English | MEDLINE | ID: mdl-38713491

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the long-term incidence, risk factors, and the management of corneal melt following Boston type I keratoprosthesis (B-KPro I) implantation. METHODS: This is a retrospective observational case series. Data were collected regarding demographics, preoperative characteristics, incidence, and outcomes of corneal melt in 102 patients who underwent B-KPro I in the Chinese PLA General Hospital between 2011 and 2018, with a follow-up period ranging from 4 to 11 years. RESULTS: Chemical burn was the most common indication for B-KPro I (n = 56; 53.8%), followed by ocular trauma (n = 26; 25.0%). During the follow-up period (107 ± 25.7 months), corneal melt occurred in 60 cases among 37 eyes (35.6%), with an incidence of 20.2% at 1 year after surgery. Fourteen cases presented with recurrent corneal melt. Patients with multiple corneal allograft failures had a higher risk of corneal melt. Thermal burns, compared with alkali burns, significantly elevated the odds ratio (OR) of corneal melt (OR, 5.11; 95% confidence interval, 1.05-24.86; P = 0.043). CONCLUSIONS: Corneal melt significantly reduced the retention time of KPro (P < 0.01), and its coexistence with other complications further shortened the retention time. A specific pattern of corneal melt occurrence was identified, with a peak incidence at 1 year postoperatively. Our findings suggest variations in the risk of corneal melt among different indications, with thermal burns carrying the highest OR. Moreover, each previous failed keratoplasty doubled the risk of corneal melt after B-KPro I.

13.
Cerebrovasc Dis ; 2024 May 15.
Article in English | MEDLINE | ID: mdl-38749409

ABSTRACT

BACKGROUND AND PURPOSE: We aimed to determine predictors of early (END) and delayed neurological deterioration (DND) and their association with functional outcome in patients with acute ischemic stroke (AIS) who participated in the international Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED). METHODS: END and DND were defined as scores of a ≥2 point increase on the National Institutes of Health Stroke Scale (NIHSS) or ≥1 point decrease on Glasgow coma scale, or death, from baseline to 24 hours and 24 hours to 72 hours, respectively. Multivariable logistic regression models were used to determine independent predictors of END and DND and their association with 90-day outcomes (dichotomous scores on the modified Rankin scale [mRS] of 2-6 vs 0-1 and 3-6 vs 0-2, and death). RESULTS: Of 4496 patients, 871 (19.4%) and 302 (8.4%) patients experienced END and DND, respectively. Higher baseline NIHSS score, older age, large artery occlusion due to significant atheroma, cardioembolic stroke subtype, hemorrhagic infarction and parenchymatous hematoma within 24 hours, were all independent predictors for both END (all P ≤0.01) and DND (all P ≤0.024). Moreover, higher baseline systolic blood pressure (BP) (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.02-1.12), higher diastolic BP variability within 24 hours (OR 1.07, 95% CI 1.04-1.09), patients from Asia (OR 1.25, 95% CI 1.03-1.52) were the only independent predictors for END. However, Asian ethnicity was negatively associated with DND (OR 0.64, 95% CI 0.47-0.86). Hemorrhagic infarction and parenchymatous hematoma within 24 hours were the key predictor of END across all stroke subtypes. END and DND were all associated with a poor functional outcome at 90 days (all P<0.001). CONCLUSIONS: We identified overlapping and unique demographic and clinical predictors of END and DND after thrombolysis for acute ischemic stroke. Both END and DND predict unfavorable outcomes at 90 days.

14.
N Engl J Med ; 2024 May 16.
Article in English | MEDLINE | ID: mdl-38752650

ABSTRACT

BACKGROUND: Treatment of acute stroke, before a distinction can be made between ischemic and hemorrhagic types, is challenging. Whether very early blood-pressure control in the ambulance improves outcomes among patients with undifferentiated acute stroke is uncertain. METHODS: We randomly assigned patients with suspected acute stroke that caused a motor deficit and with elevated systolic blood pressure (≥150 mm Hg), who were assessed in the ambulance within 2 hours after the onset of symptoms, to receive immediate treatment to lower the systolic blood pressure (target range, 130 to 140 mm Hg) (intervention group) or usual blood-pressure management (usual-care group). The primary efficacy outcome was functional status as assessed by the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days after randomization. The primary safety outcome was any serious adverse event. RESULTS: A total of 2404 patients (mean age, 70 years) in China underwent randomization and provided consent for the trial: 1205 in the intervention group and 1199 in the usual-care group. The median time between symptom onset and randomization was 61 minutes (interquartile range, 41 to 93), and the mean blood pressure at randomization was 178/98 mm Hg. Stroke was subsequently confirmed by imaging in 2240 patients, of whom 1041 (46.5%) had a hemorrhagic stroke. At the time of patients' arrival at the hospital, the mean systolic blood pressure in the intervention group was 158 mm Hg, as compared with 170 mm Hg in the usual-care group. Overall, there was no difference in functional outcome between the two groups (common odds ratio, 1.00; 95% confidence interval [CI], 0.87 to 1.15), and the incidence of serious adverse events was similar in the two groups. Prehospital reduction of blood pressure was associated with a decrease in the odds of a poor functional outcome among patients with hemorrhagic stroke (common odds ratio, 0.75; 95% CI, 0.60 to 0.92) but an increase among patients with cerebral ischemia (common odds ratio, 1.30; 95% CI, 1.06 to 1.60). CONCLUSIONS: In this trial, prehospital blood-pressure reduction did not improve functional outcomes in a cohort of patients with undifferentiated acute stroke, of whom 46.5% subsequently received a diagnosis of hemorrhagic stroke. (Funded by the National Health and Medical Research Council of Australia and others; INTERACT4 ClinicalTrials.gov number, NCT03790800; Chinese Trial Registry number, ChiCTR1900020534.).

15.
Nat Protoc ; 2024 May 14.
Article in English | MEDLINE | ID: mdl-38745111

ABSTRACT

Microbial signatures have emerged as promising biomarkers for disease diagnostics and prognostics, yet their variability across different studies calls for a standardized approach to biomarker research. Therefore, we introduce xMarkerFinder, a four-stage computational framework for microbial biomarker identification with comprehensive validations from cross-cohort datasets, including differential signature identification, model construction, model validation and biomarker interpretation. xMarkerFinder enables the identification and validation of reproducible biomarkers for cross-cohort studies, along with the establishment of classification models and potential microbiome-induced mechanisms. Originally developed for gut microbiome research, xMarkerFinder's adaptable design makes it applicable to various microbial habitats and data types. Distinct from existing biomarker research tools that typically concentrate on a singular aspect, xMarkerFinder uniquely incorporates a sophisticated feature selection process, specifically designed to address the heterogeneity between different cohorts, extensive internal and external validations, and detailed specificity assessments. Execution time varies depending on the sample size, selected algorithm and computational resource. Accessible via GitHub ( https://github.com/tjcadd2020/xMarkerFinder ), xMarkerFinder supports users with diverse expertise levels through different execution options, including step-to-step scripts with detailed tutorials and frequently asked questions, a single-command execution script, a ready-to-use Docker image and a user-friendly web server ( https://www.biosino.org/xmarkerfinder ).

16.
Chem Commun (Camb) ; 60(41): 5459-5462, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38689549

ABSTRACT

The lack of suitable cathode materials has hampered the further development of calcium-ion batteries (CIBs). A novel composite cathode material, namely BaV6O16·3H2O@GO, was fabricated, which delivers a high specific capacity of 285.72 mA h g-1 at 50 mA g-1 after 50 cycles and a long cycle life, benefiting from a large layer spacing and robust structure. This study provides guidance for the development of vanadium-based cathode materials for CIBs.

17.
J Plant Res ; 2024 May 13.
Article in English | MEDLINE | ID: mdl-38739241

ABSTRACT

Reevesia is an eastern Asian-eastern North American disjunction genus in the family Malvaceae s.l. and comprises approximately 25 species. The relationships within the genus are not well understood. Here, 15 plastomes representing 12 Reevesia species were compared, with the aim of better understanding the species circumscription and phylogenetic relationships within the genus and among genera in the family Malvaceae s.l. The 11 newly sequenced plastomes range between 161,532 and 161, 945 bp in length. The genomes contain 114 unique genes, 18 of which are duplicated in the inverted repeats (IRs). Gene content of these plastomes is nearly identical. All the protein-coding genes are under purifying selection in the Reevesia plastomes compared. The top ten hypervariable regions, SSRs, and the long repeats identified are potential molecular markers for future population genetic and phylogenetic studies. Phylogenetic analysis based on the whole plastomes confirmed the monophyly of Reevesia and a close relationship with Durio (traditional Bombacaceae) in subfamily Helicteroideae, but not with the morphologically similar genera Pterospermum and Sterculia (both of traditional Sterculiaceae). Phylogenetic relationships within Reevesia suggested that two species, R. pubescens and R. thyrsoidea, as newly defined, are not monophyletic. Six taxa, R. membranacea, R. xuefengensis, R. botingensis, R. lofouensis, R. longipetiolata and R. pycnantha, are suggested to be recognized.

18.
Nature ; 2024 May 08.
Article in English | MEDLINE | ID: mdl-38720078

ABSTRACT

Electrocaloric1,2 and electrostrictive3,4 effects concurrently exist in dielectric materials. Combining these two effects could achieve the lightweight, compact localized thermal management that is promised by electrocaloric refrigeration5. Despite a handful of numerical models and schematic presentations6,7, current electrocaloric refrigerators still rely on external accessories to drive the working bodies8-10 and hence result in a low device-level cooling power density and coefficient of performance (COP). Here we report an electrocaloric thin-film device that uses the electro-thermomechanical synergy provided by polymeric ferroelectrics. Under one-time a.c. electric stimulation, the device is thermally and mechanically cycled by the working body itself, resulting in an external-driver-free, self-cycling, soft refrigerator. The prototype offers a directly measured cooling power density of 6.5 W g-1 and a peak COP exceeding 58 under a zero temperature span. Being merely a 30-µm-thick polymer film, the device achieved a COP close to 24 under a 4 K temperature span in an open ambient environment (32% thermodynamic efficiency). Compared with passive cooling, the thin-film refrigerator could immediately induce an additional 17.5 K temperature drop against an electronic chip. The soft, polymeric refrigerator can sense, actuate and pump heat to provide automatic localized thermal management.

19.
iScience ; 27(5): 109724, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38711457

ABSTRACT

This work introduces a pioneering approach in the development of organic thin-film transistors (OTFTs), featuring a double-layer dielectric structure that combines poly(para-xylylene)s (Parylene) and poly(methyl methacrylate) (PMMA) to leverage the high insulation properties and high surface polarity of Parylene with the low insulation properties and low surface polarity of PMMA. This combination results in devices that showcase significantly enhanced electrical performance, including superior charge carrier mobility, increased current on/off ratios, and greater transconductance. Utilizing poly(3-hexylthiophene) (P3HT) for the active layer, the study demonstrates the advantage of the dual dielectric layers in minimizing hysteresis in the transfer curve, thereby facilitating the systematic growth of the organic active layer and enhancing electrical conductivity over single-layer alternatives. The superior performance of the Parylene/PMMA double-layer insulating structure opens new avenues for the advancement of organic electronics, presenting methodologies for performance optimization and expanding the application spectrum of OTFTs.

20.
Ecol Evol ; 14(5): e11336, 2024 May.
Article in English | MEDLINE | ID: mdl-38711485

ABSTRACT

The preservation or removal of apical meristem in Leymus chinensis is contingent upon grazing intensity and has a significant impact on above- and belowground biomass, nutritive value, and sustainability of L. chinensis grassland. However, this topic remains understudied. Therefore, a manipulative trial was conducted to induce grazing defoliation through mowing, where two post-grazing heights (preservation or removal of the apical meristem) and four pre-grazing plant heights (i.e., 18, 24, 31, and 35 cm) are combined factorially to create gradients of grazing intensities, resulting in a total of eight treatments. Additionally, two identical control treatments are also incorporated. Our results showed that apical meristem removal at various pre-grazing heights resulted in varying degrees of increased grazing intensities, thereby enhancing the nutritive value of L. chinensis. However, this practice also led to detrimental effects on the plant's carbohydrates reserve as well as herbage mass. The results indicated that although defoliation in treatments involving apical meristem removal resulted in the highest number of frequent cuttings, it did not confer any advantages in terms of herbage mass and nutrient preserves, except for herbage nutritive values when compared to treatments involving apical meristem preservation. The apical meristem preservation treatments demonstrated the highest CP yield over a 2-year period compared to the apical meristem removal treatments. Furthermore, within these apical meristem preservation treatments, only when the pre-grazing height is 35 cm and post-grazing height is 17 cm, there is no significant decrease in above- and belowground biomass. This establishes this specific defoliation regime as an optimal and effective management strategy for L. chinensis grassland.

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