269 research outputs found
Optimal design of photovoltaic shading systems for multi-story buildings
This study provides new insights into the comprehensive energy and economic performances of photovoltaic shading systems (PVSS) in multi-story buildings. A numerical shading model was developed to evaluate the shading effect from an upper PVSS row on its subjacent row. Simulation models based on EnergyPlus were developed to analyze the net electricity consumption (NEC) of PVSS with different tilt angles and widths in different climates. Benefit per capacity (BC) and the cost of benefit (CB) indicators were used to analyze the economic performances of PVSS. Finally, the optimum PVSS tilt angles and widths in different cities were obtained. Harbin, Beijing, Changsha, Kunming, and Guangzhou, were selected as representative cities for different geographical and climatic conditions. The results indicate that the optimum tilt angles for PVSS installed in Harbin, Beijing, Changsha, Kunming and Guangzhou are 55°, 50°, 40°, 40° and 30°, respectively. Optimum PVSS width for all five cities is 1.156m (7 columns of standard solar cells). PVSS installed, using the optimal design scheme, in multi-story buildings have better energy-saving potentials than either rooftop photovoltaic systems or traditional power supply modes for commercial buildings in China
Widespread Presence of Glycolaldehyde and Ethylene Glycol Around Sagittarius B2
We report the detection of widespread CHOHCHO and HOCHCHOH
emission in Galactic center giant molecular cloud Sagittarius B2 using the
Shanghai Tianma 65m Radio Telescope. Our observations show for the first time
that the spatial distribution of these two important prebiotic molecules
extends over 15 arc-minutes, corresponding to a linear size of approximately 36
pc. These two molecules are not just distributed in or near the hot cores. The
abundance of these two molecules seems to decrease from the cold outer region
to the central region associated with star-formation activity. Results present
here suggest that these two molecules are likely to form through a low
temperature process. Recent theoretical and experimental studies demonstrated
that prebiotic molecules can be efficiently formed in icy grain mantles through
several pathways. However, these complex ice features cannot be directly
observed, and most constraints on the ice compositions come from millimeter
observations of desorbed ice chemistry products. These results, combined with
laboratory studies, strongly support the existence of abundant prebiotic
molecules in ices.Comment: 20 pages, 7 figures, accepted by Ap
Observation of symptomatic thromboembolic events in endoscopic retrograde cholangiopancreatography patients with interruption of antithrombotic therapies
Background and objectivesAn increasing number of patients with antithrombotic therapies are undergoing endoscopic retrograde cholangiopancreatography (ERCP). Interruption of antithrombotic therapies may be associated with a higher risk of symptomatic thromboembolic (TE) events. We aimed to investigate the risk of symptomatic TE events among patients undergoing ERCP.MethodsA retrospective cohort study on patients at risk for symptomatic TE events who had undergone ERCP from January 2016 to October 2023 was conducted. A total of 2,482 patients who had undergone ERCP were included in this study. We compared the risk of symptomatic TE events within 30 days after ERCP between the group treated with antithrombotic agent and the group not treated with antithrombotic agent using multivariate regression analysis adjusted for covariates.ResultsA total of 15 patients (0.60%, 15/2,482) developed symptomatic TE events within 30 days after ERCP. The symptomatic TE event rate in subjects on any antithrombotic drug was 1.46% with an odds ratio (OR) of 5.267 (n = 689, 95% CI 1.79–15.46, p = 0.002), compared with those not treated with antithrombotic drugs (n = 1,793). The symptomatic TE event rate in subjects on temporary interruption of antithrombotic drugs was 1.48% with an OR of 5.36 (n = 677, 95% CI 1.83–15.74, p = 0.002), compared with those not treated with antithrombotic drugs (n = 1,793). Multivariate regression analysis indicated that patients with high-risk conditions had a significantly higher risk of post-ERCP symptomatic TE events (adjusted OR 11.73, 95% CI 2.23–61.70).ConclusionInterruption of antithrombotic drugs is associated with higher post-ERCP symptomatic TE events, particularly in high-risk conditions
LDC7559 inhibits microglial activation and GSDMD-dependent pyroptosis after subarachnoid hemorrhage
Mounting evidence indicates that inhibition of microglial activation and neuronal pyroptosis plays important roles in brain function recovery after subarachnoid hemorrhage (SAH). LDC7559 is a newly discovered gasdermin D (GSDMD) inhibitor. Previous studies have demonstrated that LDC7559 could inhibit microglial proliferation and pyroptosis. However, the beneficial effects of LDC7559 on SAH remain obscure. Based on this background, we investigated the potential role and the mechanism of LDC7559 on SAH-induced brain damage both in vivo and in vitro. The findings revealed that microglial activation and neuronal pyroptosis were evidently increased after SAH, which could be markedly suppressed by LDC7559 both in vivo and in vitro. Meanwhile, LDC7559 treatment reduced neuronal apoptosis and improved behavior function. Mechanistically, LDC7559 decreased the levels of GSDMD and cleaved GSDMD after SAH. In contrast, nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation by nigericin increased GSDMD-mediated pyroptosis and abated the beneficial effects of LDC7559 on SAH-induced brain damage. However, LDC7559 treatment did not significantly affect the expression of NLRP3 after SAH. Taken together, LDC7559 might suppress neuronal pyroptosis and microglial activation after SAH by inhibiting GSDMD, thereby promoting brain functional recovery
Precision Removal of Uneven Skin Tissue at the Micrometer Level via Focus-Corrected Femtosecond-Laser Ablation
From the perspective of aesthetic surgery and regenerative medicine, the precision of surgical instruments is critical for preventing aesthetic complications during procedures such as skin debridement and the removal of unwanted tissues, as well as for better regeneration. Femtosecond lasers (fs-lasers) can achieve micrometer-level tissue removal. However, an uneven skin texture can cause the laser to defocus, leading to iatrogenic injury and hindering clinical application. Overcoming the defocusing tendency of fs-lasers is therefore crucial for their clinical use
Tenofovir alafenamide versus entecavir for treating hepatitis B virus-related acute-on-chronic liver failure: real-world study
Background and aimsReal-world data regarding hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) patients receiving tenofovir alafenamide (TAF) as an antiviral drug are limited. Hence, we evaluated the efficacy and kidney safety of TAF among this population.MethodsA total of 272 HBV-related ACLF patients hospitalized at Xiangya Hospital of Central South University were enrolled in this retrospective research. All patients received antiviral therapy with TAF (n = 100) or ETV (n = 172) and comprehensive medical treatments.ResultsThrough 1:1 propensity score matching, 100 patients were finally included in each group. At week 48, the survival rates without transplantation of the TAF group and ETV group were 76.00 and 58.00%, separately (P = 0.007). After 4 weeks of treatment, the TAF treatment group exhibited a significantly decline in HBV DNA viral load (P = 0.029). The mean estimated glomerular filtration rate was apparently improved in the TAF group compared with the ETV group (TAF 5.98 ± 14.46 vs. ETV 1.18 ± 18.07 ml/min/1.73 m2) (P < 0.05). There were 6 patients in TAF group and 21 patients in ETV group with chronic kidney disease (CKD) stage progression ≥ 1. By contrast, the ETV treatment group has a greater risk of renal function progression in CKD 1 stage patients (P < 0.05).ConclusionThis real-world clinical study showed that TAF is more effective than ETV in reducing viral load and improving survival rate in HBV-ACLF patients and the risk of renal function decline is lower.Clinical trial registrationhttps://ClinicalTrials.gov, identifier NCT05453448
Ultra-short lifetime isomer studies from photonuclear reactions using laser-driven ultra-intense {\gamma}-ray
Isomers, ubiquitous populations of relatively long-lived nuclear excited
states, play a crucial role in nuclear physics. However, isomers with half-life
times of several seconds or less barely had experimental cross section data due
to the lack of a suitable measuring method. We report a method of online
{\gamma} spectroscopy for ultra-short-lived isomers from photonuclear reactions
using laser-driven ultra-intense {\gamma}-rays. The fastest time resolution can
reach sub-ps level with {\gamma}-ray intensities >10^{19}/s ({\geqslant} 8
MeV). The ^{115}In({\gamma}, n)^{114m2}In reaction (T_{1/2} = 43.1 ms) was
first measured in the high-energy region which shed light on the nuclear
structure studies of In element. Simulations showed it would be an efficient
way to study ^{229m}Th (T_{1/2} = 7 {\mu}s), which is believed to be the next
generation of nuclear clock. This work offered a unique way of gaining insight
into ultra-short lifetimes and promised an effective way to fill the gap in
relevant experimental data
The Progress of CDAS
The Chinese Data Acquisition System (CDAS) based on FPGA techniques has been developed in China for the purpose of replacing the traditional analog baseband converter. CDAS is a high speed data acquisition and processing system with 1024 Msps sample rate for 512M bandwidth input and up to 16 channels (both USB and LSB) output with VSI interface compatible. The instrument is a flexible environment which can be updated easily. In this paper, the construction, the performance, the experiment results, and the future plans of CDAS will be reported
Fluorescent core-shell silica nanoparticles as tunable precursors: towards encoding and multifunctional nano-probes
Core-shell silica nanoparticles comprised of a RuBpy doped silica core and a Pas-DTPA doped silica shell were synthesized and post-functionalized with an encoding fluorescence combination and multiplex imaging function
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