Solar-thermal energy conversion and storage technology has attracted great interest in the past few decades. Phase change materials (PCMs), by storing and releasing solar energy, are able to ...effectively address the imbalance between energy supply and demand, but they still have the disadvantage of low thermal conductivity and leakage problems. In this work, new form-stable solar thermal storage materials by impregnating paraffin PCMs within porous copper-graphene (G-Cu) heterostructures were designed, which integrated high thermal conductivity, high solar energy absorption, and anti-leakage properties. In this new structure, graphene can directly absorb and store solar energy in the paraffin PCMs by means of phase change heat transfer. The porous structure provided good heat conduction, and the large surface area increased the loading capacity of solar thermal storage materials. The small pores and superhydrophobic surfaces of the modified porous G-Cu heterostructures effectively hindered the leakage issues during the phase change process. The experimental results exhibited that the thermal conductivity of the prepared form-stable PCM composites was up to 2.99 W/(m·K), and no leakage took place in the solar-thermal charging process. At last, we demonstrated that the PCM composites as an energy source were easily integrated with a thermoelectric chip to generate electric energy by absorbing and converting solar energy.
With the gradual increase in energy demand in global industrialization, the energy crisis has become an urgent problem. Due to high heat storage density, small volume change, and nearly constant ...transition temperature, phase change materials (PCMs) provide a promising method to store thermal energy. In this work, we designed and fabricated three kinds of porous metal structures with hexagonal, rectangular, and circular pores and explored the phase change process of PCMs within them. A two-dimensional numerical model was established to investigate the heat transfer process of PCMs within different shapes of porous metal structures and analyze the influence of heat source location on the thermal performance of the thermal storage units. Visualization experiments were also carried out to reveal the melting process of PCMs within different porous metal structures by a digital camera. The results show that paraffin in a porous metal structure with hexagonal pores has the fastest melting rate, while that in a porous metal structure with circular pores has the slowest melting rate. Under the bottom heating mode, the melting time of the paraffin in porous metal structures with hexagonal pores is shortened by 18.6% compared to that in porous metal structures with circular pores. Under the left heating mode, the corresponding melting time is shortened by 16.7%. These findings in this work will offer an effective method to design and optimize the structure of porous metal and improve the thermal properties of PCMs.
Endothelial dysfunction is the key player in the development and progression of vascular events. Oxidative stress is involved in endothelial injury. Rosmarinic acid (RA) is a natural polyphenol with ...antioxidative, antiapoptotic, and anti-inflammatory properties. The present study investigates the protective effect of RA on endothelial dysfunction induced by hydrogen peroxide (H2O2). Compared with endothelium-denuded aortic rings, the endothelium significantly alleviated the decrease of vasoconstrictive reactivity to PE and KCl induced by H2O2. H2O2 pretreatment significantly injured the vasodilative reactivity to ACh in endothelium-intact aortic rings in a concentration-dependent manner. RA individual pretreatment had no obvious effect on the vasoconstrictive reaction to PE and KCl, while its cotreatment obviously mitigated the endothelium-dependent relaxation impairments and the oxidative stress induced by H2O2. The RA cotreatment reversed the downregulation of AMPK and eNOS phosphorylation induced by H2O2 in HAEC cells. The pretreatment with the inhibitors of AMPK (compound C) and eNOS (L-NAME) wiped off RA’s beneficial effects. All these results demonstrated that RA attenuated the endothelial dysfunction induced by oxidative stress by activating the AMPK/eNOS pathway.
At present, effective strategies for obtaining electric energy from harvesting and converting thermal energy have attracted great attention in the field of new energy. According to the working ...principle of electrostatic induction and triboelectrification, the triboelectric nanogenerators (TENGs) technology is regarded as a promising energy harvester. Herein, we propose a novel thermal-electric generator that combines a liquid-solid TENG and a 3D pulsating heat pipe (3D-PHP). The liquid-solid TENG consists of copper foil and polytetrafluoroethylene (PTFE) tubes, and 50 % deionized water is filled into the 3D-PHP. Based on phase change heat transfer, water columns in the 3D-PHP will pulsate and flow through a liquid-solid TENG, leading to the generation of electric energy. The minimum thermal resistance of this 3D-PHP with TENGs is only 0.131 K/W at a heating power of 200 W, indicating it has excellent heat transfer performance. The peak output voltage and power generated by the developed 3D-PHP generator are up to 14 V and 1.05 μW, respectively. Finally, the harvested electricity is successfully applied to power a digital thermometer. These findings will offer a promising strategy for harvesting thermal energy from electronic equipment and systems involving high-flux heat production and dissipation.
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•A device by integrating a triboelectric nanogenerator into a three-dimensional pulsating heat pipe is proposed.•The 3D-PHP generator realizes efficient heat transfer and output power simultaneously.•More than 14.0 V of output voltage and more than 1.05 μW of peak power are obtained.
To the best of our knowledge, there is no study that has conducted a review investigating the clinical efficacy and safety of bisoprolol combined with trimetazidine on chronic heart failure (CHF) ...patients with chronic obstructive pulmonary disease (COPD). Therefore, in order to provide new evidence-based medical evidence for clinical treatment, we undertook a systematic review and meta-analysis to assess the effectiveness and safety of bisoprolol combined with trimetazidine on CHF patients with COPD.
Seven electronic databases including Web of Science, Embase, PubMed, Wanfang Data, Scopus, Science Direct, Cochrane Library will be searched in April 2021 by 2 independent reviewers. For search on PubMed, the following search terms will be used: "trimetazidine, bisoprolol, chronic heart failure, chronic obstructive pulmonary disease." In order to achieve a consistency of extracted items, the data extractors will extract data from a sample of eligible studies. The outcomes include all-cause mortality and hospitalization for cardiac or/and respiratory causes; left ventricular structure and function; and functional scores. Review Manager software (v 5.4; Cochrane Collaboration) will be used for the meta-analysis. Two independent reviewers will assess the risk of bias of the included studies at study level. Any disagreements will be discussed and resolved in discussion with a third reviewer.
The results of our review will be reported strictly following the PRISMA criteria.
The review will add to the existing literature by showing compelling evidence and improved guidance in clinic settings.
10.17605/OSF.IO/ZWPRB.
•The gradient porous metal structure was fabricated by metal 3D printing technology.•The effect of gradient porous structure and heating position on PCM was studied.•Visualization experiments were ...carried out to observe the melting process of PCM.•The gradient porous metal structure could improve the heat storage performance.
As the global economy steadily develops and the rapid growth in industrialization increases, the world is gradually moving towards a serious energy crisis, and finding effective energy utilization methods becomes a consensus. Phase change materials (PCMs) have a wide range of applications in thermal energy storage due to their advantages of high thermal storage density, good cyclic performance, low cost, and environmental friendliness. In this work, the phase change process of the paraffin in uniform and gradient porous metal structures is investigated by simulation and experiments. Thermal storage units combined with paraffin and porous metal structures are designed and fabricated by metal 3D printing technology. A numerical model is established to explore the influence of the gradient porosity and heating source location on the melting process of the paraffin within different thermal storage units. To verify the correctness of the numerical model, visualization experiments are carried out to observe the phase change process of the paraffin. Both the simulated and experimental results demonstrate that the gradient porosity and heating source position greatly influence the paraffin's melting behavior in the porous metal structure. Compared to the uniform porous metal structure, the melting time of the paraffin in the gradient porous metal structure under the bottom and left heating mode can be shortened by 11.26% and 6.21%, respectively. The findings of this study are of considerable scientific and technological interest for developing and optimizing composite phase change thermal storage materials.
Previous research has suggested that Xuebijing injection (XBJ), an herbal-based intravenous preparation, may reduce mortality among patients with sepsis.
To determine the effect of XBJ vs placebo on ...28-day mortality among patients with sepsis.
The Efficacy of Xuebijing Injection in Patients With Sepsis (EXIT-SEP) trial was a multicenter, randomized double-blind, placebo-controlled trial conducted in intensive care units at 45 sites and included 1817 randomized patients with sepsis (sepsis 3.0) present for less than 48 hours. Patients aged 18 to 75 years with a Sequential Organ Failure Assessment score of 2 to 13 were enrolled. The study was conducted from October 2017 to June 2019. The final date of follow-up was July 26, 2019. Data analysis was performed from January 2020 to August 2022.
The patients were randomized to receive either intravenous infusion of XBJ (100 mL, n = 911) or volume-matched saline placebo (n = 906) every 12 hours for 5 days.
The primary outcome was 28-day mortality.
Among the 1817 patients who were randomized (mean SD age, 56.5 13.5 years; 1199 66.0% men), 1760 (96.9%) completed the trial. In these patients, the 28-day mortality rate was significantly different between the placebo group and the XBJ group (230 of 882 patients 26.1% vs 165 of 878 patients 18.8%, respectively; P < .001). The absolute risk difference was 7.3 (95% CI, 3.4-11.2) percentage points. The incidence of adverse events was 222 of 878 patients (25.3%) in the placebo group and 200 of 872 patients (22.9%) in the XBJ group.
In this randomized clinical trial among patients with sepsis, the administration of XBJ reduced 28-day mortality compared with placebo.
ClinicalTrials.gov Identifier: NCT03238742.
CKLF-like MARVEL transmembrane domain-containing family （CMTM） is a family of proteins linking classical chemokines and the transmembrane-4 superfamily （TM4SF）. In humans, they are encoded by nine ...genes, including chemokine-like factor （CKLF） and CMTM1 to CMTM8 1.
Convolution neural network (CNN) utilizes alternating convolutional and pooling layers to learn representative spatial information when the training samples are sufficient. However, for pixelwise ...classification of hyperspectral image, some important information is neglected by CNN, such as the erased information by the pooling operation and the appearance information from lower layers. Moreover, the lack of training samples is a common situation in remote sensing area, which afflicts CNN with overfitting problem. To address the aforementioned issues, this paper designs an end-to-end deconvolution network with skip architecture to learn the spectral-spatial features. The proposed network starts with two branches, i.e., the spatial branch and spectral branch. In the spatial branch, a band selection layer is designed to reduce parameters and remit the overfitting problem, unpooling and deconvolution operations are utilized to recover the erased information of the pooling layers and learn pixelwise spatial representation hierarchically, and the skip architecture is constructed for merging the deep semantic information with the shallow appearance information. In the spectral branch, a contextual deep network is employed for learning deep spectral features. Experimental results on three benchmark data sets reveal the competitive performance of the proposed approach over several related methods.
Two-Dimensional (2D) materials have attracted immense attention in recent years. These materials have found their applications in various fields, such as catalysis, adsorption, energy storage, and ...sensing, as they exhibit excellent physical, chemical, electronic, photonic, and biological properties. Recently, researchers have focused on constructing porous structures on 2D materials. Various strategies, such as chemical etching and template-based methods, for the development of surface pores are reported, and the porous 2D materials fabricated over the years are used to develop supercapacitors and energy storage devices. Moreover, the lattice structure of the 2D materials can be modulated during the construction of porous structures to develop 2D materials that can be used in various fields such as lattice defects in 2D nanomaterials for enhancing biomedical performances. This review focuses on the recently developed chemical etching, solvent thermal synthesis, microwave combustion, and template methods that are used to fabricate porous 2D materials. The application prospects of the porous 2D materials are summarized. Finally, the key scientific challenges associated with developing porous 2D materials are presented to provide a platform for developing porous 2D materials.
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