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Different facets in perovskite crystals exhibit distinct atomic arrangements, influencing their electronic, physical, and chemical properties. Perovskite films incorporating tin oxide (SnO2) as the electron transport layer face challenges in facet regulation. This study reveals that tea saponin (TS), a natural compound serves as a SnO2 modifier, facilitates optimal growth of perovskite crystals on the (111) facet. The modification promotes preferential crystal orientation through hydrogen bond and Lewis coordination. TS forms a chelate with SnO2, resulting in a smoother film and n-type doping, leading to improved carrier extraction and reduced defects. The TS-modified perovskite solar cells achieve a champion efficiency of 24.2%, leveraging from an obvious enhancement of open-circuit voltage (Voc) of 1.18 V and fill factor (FF) of 82.8%. The devices also demonstrate enhanced humidity tolerance and storage stability, ensuring improved stability without encapsulation.
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As urbanization proceeds, urban transportation resilience suffers greater challenges. Covering panel data for 35 Chinese cities from 2006 to 2019, after controlling for other variables that may affect urban residents' transportation volumes, this paper finds that rising houseing prices have a significant positive effect on urban residents' traffic frequency. As frequent traffic trips increase the probability of urban residents experiencing disruptions, rising housing purchase prices would have a negative impact on Chinese urban residents' transportation resilience. The regional comparison analysis finds that the regression coefficients of coastal and eastern cities with more expensive housing price are significantly higher than those of non-coastal and western cities with lower housing price, further validating the findings of this paper.
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All man-made flying objects in the sky, ships in the ocean can be regarded as small infrared targets, and the method of tracking them has been received widespread attention in recent years. In search of a further efficient method for infrared small target recognition, we propose a hierarchical attention-guided multiscale aggregation network (HAMANet) in this thesis. The proposed HAMANet mainly consists of a compound guide multilayer perceptron (CG-MLP) block embedded in the backbone net, a spatial-interactive attention module (SiAM), a pixel-interactive attention module (PiAM) and a contextual fusion module (CFM). The CG-MLP marked the width-axis, height-axis, and channel-axis, which can result in a better segmentation effect while reducing computational complexity. SiAM improves global semantic information exchange by increasing the connections between different channels, while PiAM changes the extraction of local key information features by enhancing information exchange at the pixel level. CFM fuses low-level positional information and high-level channel information of the target through coding to improve network stability and target feature utilization. Compared with other state-of-the-art methods on public infrared small target datasets, the results show that our proposed HAMANet has high detection accuracy and a low false-alarm rate.
Subject(s)
Neural Networks, Computer , Recognition, Psychology , Humans , Semantics , Image Processing, Computer-AssistedABSTRACT
The two-step sequential deposition strategy has been widely recognized in promoting the research and application of perovskite solar cells, but the rapid reaction of organic salts with lead iodide inevitably affects the growth of perovskite crystals, accompanied by the generation of more defects. In this study, the regulation of crystal growth was achieved in a two-step deposition method by mixing 1-naphthylmethylammonium bromide (NMABr) with organic salts. The results show that the addition of NMABr effectively delays the aggregation and crystallization behavior of organic salts; thereby, the growth of the optimal crystal (001) orientation of perovskite is promoted. Based on this phenomenon of delaying the crystallization process of perovskite, the "slow-release effect assisted crystallization" is defined. Moreover, the incorporation of the Br element expands the band gap of perovskite and mitigates material defects as nonradiative recombination centers. Consequently, the power conversion efficiency (PCE) of the enhanced perovskite solar cells (PSCs) reaches 20.20%. It is noteworthy that the hydrophobic nature of the naphthalene moiety in NMABr can enhance the humidity resistance of PSCs, and the perovskite phase does not decompose for more than 3000 h (30-40% RH), enabling it to retain 90% of its initial efficiency even after exposure to a nitrogen environment for 1200 h.
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Harnessing the inexhaustible solar energy for water splitting is regarded one of the most promising strategies for hydrogen production. However, sluggish kinetics of oxygen evolution reaction (OER) and expensive photovoltaics have hindered commercial viability. Here, an adhesive-free electrodeposition process is developed for in-situ preparation of earth-abundant electrocatalysts on super-flat indium tin oxide (ITO) substrate. NiFe hydroxide exhibited prominent OER performance, achieving an ultra-low overpotential of 236 mV at 10 mA/cm2 in alkaline solution. With the superior OER activity, we achieved an unassisted solar water splitting by series connected perovskite solar cells (PSCs) of 2 cm2 aperture area with NiFe/ITO//Pt electrodes, yielding overall solar to hydrogen (STH) efficiency of 13.75 %. Furthermore, we upscaled the monolithic facility to utilize perovskite solar module for large-scale hydrogen production and maintained an approximate operating current of 20 mA. This creative strategy contributes to the decrease of industrial manufacturing expenses for perovskite-based photovoltaic-electrochemical (PV-EC) hydrogen production, further accelerating the conversion and utilization of carbon-free energy.
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Killer meiotic drivers (KMDs) skew allele transmission in their favor by killing meiotic progeny not inheriting the driver allele. Despite their widespread presence in eukaryotes, the molecular mechanisms behind their selfish behavior are poorly understood. In several fission yeast species, single-gene KMDs belonging to the wtf gene family exert selfish killing by expressing a toxin and an antidote through alternative transcription initiation. Here we investigate how the toxin and antidote products of a wtf-family KMD gene can act antagonistically. Both the toxin and the antidote are multi-transmembrane proteins, differing only in their N-terminal cytosolic tails. We find that the antidote employs PY motifs (Leu/Pro-Pro-X-Tyr) in its N-terminal cytosolic tail to bind Rsp5/NEDD4 family ubiquitin ligases, which ubiquitinate the antidote. Mutating PY motifs or attaching a deubiquitinating enzyme transforms the antidote into a toxic protein. Ubiquitination promotes the transport of the antidote from the trans-Golgi network to the endosome, thereby preventing it from causing toxicity. A physical interaction between the antidote and the toxin enables the ubiquitinated antidote to translocate the toxin to the endosome and neutralize its toxicity. We propose that post-translational modification-mediated protein localization and/or activity changes may be a common mechanism governing the antagonistic duality of single-gene KMDs.
Subject(s)
Schizosaccharomyces , Schizosaccharomyces/genetics , Schizosaccharomyces/metabolism , Antidotes , Ubiquitination , Golgi Apparatus/metabolism , Ubiquitin/metabolism , Endosomal Sorting Complexes Required for Transport/metabolism , Ubiquitin-Protein Ligases/metabolismABSTRACT
BACKGROUND@#Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease, lymphadenitis, and disseminated disease in cases of advanced immune suppression. Data on patients coinfected with HIV and NTM are limited. Thus, this study aimed to analyze the clinical characteristics, drug resistance, and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.@*METHODS@#Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu, between January 2014 and December 2018, were analyzed. NTM drug sensitivity testing was performed using the microporous plate ratio method. Data were analyzed using SPSS 19.0, and the change in drug resistance rate was analyzed using the chi-square (χ) test.@*RESULTS@#Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study, with Mycobacterium avium-intracellulare complex (52.5%) and M. kansasii (27.1%) as the predominant species. Male patients were more affected 50/59 (84.7%); the mean age of the 59 cases was 45 years. The clinical characteristics mainly included anemia (86.4%), cough and expectoration (79.7%). The baseline CD4 count was 0.05).@*CONCLUSIONS@#The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage; more male are affected in patients who are mainly infected with MAC and M. kansasii and with serious drug resistance. The drug resistance rate of ethambutol and clarithromycin is relatively low.
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Background@#Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease, lymphadenitis, and disseminated disease in cases of advanced immune suppression. Data on patients coinfected with HIV and NTM are limited. Thus, this study aimed to analyze the clinical characteristics, drug resistance, and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.@*Methods@#Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu, between January 2014 and December 2018, were analyzed. NTM drug sensitivity testing was performed using the microporous plate ratio method. Data were analyzed using SPSS 19.0, and the change in drug resistance rate was analyzed using the chi-square (χ2) test.@*Results@#Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study, with Mycobacterium avium–intracellulare complex (52.5%) and M. kansasii (27.1%) as the predominant species. Male patients were more affected 50/59 (84.7%); the mean age of the 59 cases was 45 years. The clinical characteristics mainly included anemia (86.4%), cough and expectoration (79.7%). The baseline CD4 count was <50 cells/μL (84.7%). Patients were mainly in advanced acquired immunodeficiency syndrome (AIDS) stage. Chest imaging mainly showed patchy shadows (42.4%) and nodules (32.2%), with various degrees of AIDS-defining diseases. The drug resistance of NTM was severe, and the rate of isoniazid resistance (100.0%) was the highest, followed by rifampicin (94.9%), streptomycin (94.9%), ofloxacin (93.2%), and others. Ethambutol (52.5%) and clarithromycin (33.9%) were relatively low. No significant difference was found in the drug resistance rate of NTM strain against nine antituberculosis drugs in 5 years (P > 0.05).@*Conclusions@#The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage; more male are affected in patients who are mainly infected with MAC and M. kansasii and with serious drug resistance. The drug resistance rate of ethambutol and clarithromycin is relatively low.
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Objective To find out the resistant situation and drug of Mycobacteria patients in Sichuan and offer foundation for clinical.Methods Two hundred randomized clinical isolates of Mycobacterium were determined by Roche drug sensitivity and minimum inhibitory concentration (MIC) method.Results Of the 200 clinical isolates,192 stains were Mycobacterium tuberculosis(MTB) (96.0%),8 strains (4.0%) were non-tuberculosis mycobacterium(NTM).Of the 192 MTB strains,108( 57.3% ) sensitive strains and 84 (43.7%)stains were resistant to one or more than one drugs.Among these 84 resistant strains 23 were multi-drug resistant ( MDR,12.0% ),4 were extensively drug resistant( XDR,2.1% ).The anti-TB drug resistance rates were:SM(16.7%),INH(20.8%),RFP(17.2%),EMB(10.9%),PI(16.1%),LFX(8.8%),AMK ( 16.7% ),CPM ( 6.2% ),PTA ( 33.3% ),respectively.Conclusion The resistance rate of tuberculosis keeps at a high level in Sichuan,especially the resistance rate of multiple (≥4) drug,we should oar attention.