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1.
J Phys Condens Matter ; 34(45)2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36055225

RESUMO

Topologically nontrivial electronic states are recently found in a family of noncentrosymmetric transition metal pnictidesTRuX(T=Zr, Hf;X=P, As), presenting a unique platform for superconductivity to interplay with topological electronic states and asymmetric spin-orbit coupling. Here, we investigate the superconducting order parameter of HfRuP and ZrRuAs by measuring the magnetic penetration depth changeΔλ(T)using a method based on the tunnel-diode oscillator. Both compounds show clear exponential temperature dependence inΔλ(T)at low temperatures, suggesting fully-gapped superconductivity. Moreover, the superfluid densities in both HfRuP and ZrRuAs can be reasonably described by ans-wave superconducting model.

2.
Artigo em Inglês | MEDLINE | ID: mdl-36078577

RESUMO

Crime prevention and governance play critical roles in public security management. Liangshan Yi Autonomous Prefecture in Sichuan Province has a high crime rate, and spatio-temporal analysis of crime in this region could assist with public security management. Therefore, Liangshan Prefecture was selected as the research object in this study. The spatial crime data were obtained from China Judgments Online, and property crime, violent crime, and special crime (i.e., pornography, gambling, drugs, and guns) were analyzed. The findings were as follows. In terms of time characteristics (month, day, and hour), property crime tended to occur in autumn and winter, in the early month, on Wednesdays and Fridays, and at early morning. Violent crime tended to occur in winter and spring, on Mondays and Thursdays, and at night. Special crime occurred in spring and autumn, on Tuesdays, and in the daytime. In terms of spatial features, the central region of Liangshan Prefecture was the focal area for crime. There were obvious low-aggregation areas in the western region for special crime. The eastern region exhibited a high incidence of various crimes. Regarding the spatio-temporal evolution characteristics from 2013 to 2019, there were some obvious hotspots of violent and property crime in downtown and surrounding townships of Xichang City, which is the capital of Liangshan Prefecture. During the study period, the incidence of special crime has an obvious downward trend which shows that there are more new cold spots.


Assuntos
Crime , China/epidemiologia , Incidência , Análise Espaço-Temporal
3.
Front Immunol ; 13: 1007176, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36148218

RESUMO

Background: Early-onset gastric cancer (EOGC, ≤45 years old) is characterized with increasing incidence and more malignant phenotypes compared with late-onset gastric cancer, which exhibits remarkable immune cell infiltration and is potential immunotherapeutic population. Till now, restricted survival information of EOGC is available due to limited case numbers. This study established a novel nomogram to help evaluate cancer-specific survival (CSS) of EOGC patients who underwent gastrectomy, and may provide evidence for predicting patients' survival. Methods: We retrospectively enrolled a cohort containing 555 EOGC cases from five independent medical centers in China, among which 388 cases were randomly selected into a training set while the other 167 cases were assigned into the internal validation set. Asian or Pacific Islander (API) patients diagnosed with EOGC during 1975-2016 were retrieved from the SEER database (n=299) and utilized as the external validation cohort. Univariate and multivariate analyses were conducted to test prognostic significances of clinicopathological factors in the training set. Accordingly, two survival nomogram models were established and compared by concordance index (C-index), calibration curve, receiver operating characteristics (ROC) curves and decision curve analyses (DCA). Results: The 5-year CSS rate of training cohort was 61.3% with a median survival time as 97.2 months. High consistency was observed on calibration curves in all three cohorts. Preferred nomogram was selected due to its better performance on ROC and DCA results. Accordingly, a novel predicative risk model was introduced to better stratify high-risk EOGC patients with low-risk patients. In brief, the 5-year CSS rates for low-risk groups were 92.9% in training set, 83.1% in internal validation set, 89.9% in combined NQSQS cohort, and 85.3% in SEER-API cohort. In contrast, the 5-year CSS rates decreased to 38.5%, 44.3%, 40.5%, and 36.9% in the high-risk groups of the four cohorts above, respectively. The significant survival difference between high-risk group (HRG) and low-risk group (LRG) indicated the precise accuracy of our risk model. Furthermore, the risk model was validated in patients with different TNM stages, respectively. Finally, an EOGC web-based survival calculator was established with public access, which can help predict prognosis. Conclusions: Our data provided a precise nomogram on predicting CSS of EOGC patients with potential clinical applicability.

4.
Small Sci ; : 2200009, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35942171

RESUMO

The ongoing global COVID-19 pandemic, caused by the SARS-CoV-2 virus, has resulted in significant loss of life since December 2019. Timely and precise virus detection has been proven as an effective solution to reduce the spread of the virus and to track the epidemic. Rapid antigen diagnostics has played a significant role in the frontline of COVID-19 testing because of its convenience, low cost, and high accuracy. Herein, different types of recently innovated in-lab and commercial antigen diagnostic technologies with emphasis on the strengths and limitations of these technologies including the limit of detection, sensitivity, specificity, affordability, and usability are systematically reviewed. The perspectives of assay development are looked into.

5.
Environ Pollut ; 310: 119918, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35952990

RESUMO

Endocrine disrupting chemicals (EDCs) have been identified as emerging contaminants, which poses a great threat to human health and ecosystem. Pesticides, polycyclic aromatic hydrocarbons, dioxins, brominated flame retardants, steroid hormones and alkylphenols are representative of this type of contaminant, which are closely related to daily life. Unfortunately, many wastewater treatment plants (WWTPs) do not treat EDCs as targets in the normal treatment process, resulting in EDCs entering the environment. Few studies have systematically reviewed the related content of EDCs in terms of occurrence, harm and remediation. For this reason, in this article, the sources and exposure routes of common EDCs are systematically described. The existence of EDCs in the environment is mainly related to human activities (Wastewater discharges and industrial activities). The common hazards of these EDCs are clarified based on available toxicological data. At the same time, the mechanism and effect of some mainstream EDCs remediation technologies (such as adsorption, advanced oxidation, membrane bioreactor, constructed wetland, etc.) are separately mentioned. Moreover, our perspectives are provided for further research of EDCs.


Assuntos
Disruptores Endócrinos , Retardadores de Chama , Purificação da Água , Ecossistema , Humanos , Águas Residuárias
6.
Mol Ther Nucleic Acids ; 29: 400-412, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36035752

RESUMO

Gene therapy would benefit from the effective editing of targeted cells with CRISPR-Cas9 tools. However, it is difficult to precisely assess the editing performance in vivo because the tissues contain many non-targeted cells, which is one of the major barriers to clinical translation. Here, in the Atoh1-GFP;Kcnq4 +/G229D mice, recapitulating a novel mutation we identified in a hereditary hearing loss pedigree, the high-efficiency editing of CRISPR-Cas9 in hair cells (34.10% on average) was precisely detected by sorting out labeled cells compared with only 1.45% efficiency in the whole cochlear tissue. After injection of the developed AAV_SaCas9-KKH_sgRNA agents, the Kcnq4 +/G229D mice showed significantly lower auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) thresholds, shorter ABR wave I latencies, higher ABR wave I amplitudes, increased number of surviving outer hair cells (OHCs), and more hyperpolarized resting membrane potentials of OHCs. These findings provide an innovative approach to accurately assess the underestimated editing efficiency of CRISPR-Cas9 in vivo and offer a promising strategy for the treatment of KCNQ4-related deafness.

7.
J Biomater Sci Polym Ed ; : 1-16, 2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-35951330

RESUMO

Bacterial infection and massive blood loss are major challenges for global public health. Herein, a series of tannic acid encapsulated O-carboxymethyl chitosan (CMC) based hydrogels were prepared using a facile approach for both hemorrhage control and effective anti-bacterium. The results indicated that the tannic acid-cosslinked CMC hydrogels had excellent mechanical property, swelling ability as well as great cytocompatibility. Comparably, with increasing tannic acid loading, the bleeding control and antibacterial performance against both E. coli and S. aureus were improved simultaneously, especially for the 5% tannic acid-cosslinked CMC hydrogel. Moreover, the prepared CMC hydrogel loading with tannic acid could induce hemocytes and platelets aggregation, promote the blood clotting and achieve bleeding control in vivo due to the interconnected fibrous web structure and the chemical activation (the phenol group of tannic acid). Thus, the resultant CMC hydrogel enabled the maintenance of high bioavailability of tannic acid and synchronization with the interconnected fibrous structure of CMC hydrogels, which was expected to be a promising candidate for robust and safe hemostatic dressings.

8.
Biochem Genet ; 2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36001185

RESUMO

Circular RNAs (circRNAs) have been reported to paly roles in the progression and management of breast cancers (BC). This work aimed to detect the role and mechanism of circ_0008717 in BC tumorigenesis. Expression levels of genes and proteins were evaluated by quantitative real-time polymerase chain reaction and western blot. In vitro assays were conducted using cell counting kit-8, colony formation, transwell, tube formation, and flow cytometry assays, respectively. The interaction between miR-326 and circ_0008717 or GATA6 (GATA Binding Protein six) was confirmed by bioinformatics analysis, and dual-luciferase reporter assay and RNA immunoprecipitation assay. The murine xenograft models were established to perform in vivo assay. Circ_0008717 and GATA6 were highly expressed, while miR-326 was lowly expressed in BC tissues and cells. Functionally, knockdown of circ_0008717 not only suppressed breast cancer cell proliferation, angiogenesis, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro, but also hindered tumor growth and EMT process in vivo. Mechanistically, Circ_0008717 directly bound to miR-326, which targeted GATA6. Rescue experiments showed that miR-326 reversed the anticancer action of circ_0008717 knockdown on BC cells. Moreover, miR-326 restoration repressed BC cell growth and metastasis, which were attenuated by GATA6 overexpression. In addition, we also observed that circ_0008717 could regulate GATA6 expression by sponging miR-326. Circ_0008717 promoted breast cancer growth and metastasis through miR-326/GATA6 axis, revealing a potential therapeutic target for breast cancer treatment.

9.
Phys Rev Lett ; 129(5): 053901, 2022 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-35960569

RESUMO

Coupling among closely packed waveguides is a common optical phenomenon, and plays an important role in optical routing and integration. Unfortunately, this coupling property is usually sensitive to the working wavelength and structure features that hinder the broadband and robust functions. Here, we report a new strategy utilizing an artificial gauge field (AGF) to engineer the coupling dispersion and realize a dispersionless coupling among waveguides with periodically bending modulation. The AGF-induced dispersionless coupling is experimentally verified in a silicon waveguide platform, which already has well-established broadband and robust routing functions (directional coupling and splitting), suggesting potential applications in integrated photonics. As examples, we further demonstrate a three-level-cascaded AGF waveguide network to route broadband light to desired ports with an overwhelming advantage over the conventional ones in comparison. Our method provides a new route of coupling dispersion control by AGF and benefits applications that fundamentally rely on waveguide coupling.

11.
Neuroreport ; 33(11): 451-462, 2022 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-35775321

RESUMO

The secondary injury plays a vital role in the development of spinal cord injury (SCI), which is characterized by the occurrence of oxidative stress, neuronal apoptosis, and inflammatory response. Notoginsenoside R1 (NGR1) has been involved in the modulation of antioxidative stress and anti-inflammatory response. However, its roles in SCI-induced injury are still unknown. We explored the therapeutic effect of NGR1 and its underlying mechanism after SCI by using behavioral, biochemical, and immunohistochemical techniques. The administration of NGR1 after SCI enhanced the neurological function, and mitigated tissue damage and motor neuron loss than those in SCI + vehicle group. Meanwhile, significantly increased expression of Nrf2 protein and HO-1 protein was found in the SCI + NGR1 group compared with those in the SCI + vehicle group. In addition, the inhibitory effects of oxidative stress, apoptotic neuron ratio, and neuronal inflammation in the SCI + NGR1 group can be partially reversed when the Nrf2/HO-1 signaling pathway was inhibited by ML385. Our results indicate that the administration of NGR1 can attenuate oxidative stress, neuronal apoptosis, and inflammation by activating the Nrf2/HO-1 signaling pathway after SCI, thereby improving neurological function.


Assuntos
Ginsenosídeos , Heme Oxigenase-1 , Traumatismos da Medula Espinal , Apoptose/efeitos dos fármacos , Ginsenosídeos/farmacologia , Heme Oxigenase-1/metabolismo , Humanos , Inflamação/tratamento farmacológico , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/metabolismo , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/metabolismo
12.
Emerg Microbes Infect ; 11(1): 1959-1972, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35848148

RESUMO

Convergence of mcr and carbapenemase genes has been sporadically detected in Enterobacter cloacae complex (ECC) with an upward trend. However, the state of the epidemic and underlying mechanism of such convergence has been poorly understood. In this study, the co-occurrence of MCR and carbapenemases was systematically analyzed in 230 clinical ECC isolates collected between 2000 and 2018 together with a global dataset consisting of 3,559 ECC genomes compiled from GenBank. We identified 48 mcr-9/mcr-10-positive isolates (MCR-ECC) (20.9%) in our collection, and a comparable ratio of MCR-ECC (720/3559, 20.2%) was detected in the global dataset. A high prevalence of carbapenemase-producing MCR-ECC (MCR-CREC) was further identified in the MCR-ECC of both datasets (16/48, 33.3%; 388/720, 53.9%), demonstrating a frequent convergence of mcr-9/10 and carbapenemase genes in ECC worldwide. An epidemic IncHI2/2A plasmid with a highly conserved backbone was identified and largely contributed to the dissemination of mcr-9 in ECC worldwide. A highly conserved IncX3-type NDM-1-carrying plasmid and IncN-type IMP-4-carrying plasmid were additionally detected in MCR-CREC isolated in China. Our surveillance data showed that MCR-CREC emerged (in 2013) much later than MCR-ECC (in 2000), indicating that MCR-CREC could be derived from MCR-ECC by additional captures of carbapenemase-encoding plasmids. Tests of plasmid stability and incompatibility showed that the mcr-9/mcr-10-encoding plasmids with the NDM-1-encoding plasmids stably remained in ECC but incompatible in Escherichia coli, suggesting that the convergence was host-dependent. The findings extend our concern on the convergence of resistance to the last resort antibiotics and highlight the necessity of continued surveillance in the future.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Enterobacter cloacae , Antibacterianos/farmacologia , Proteínas de Bactérias , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Farmacorresistência Bacteriana/genética , Enterobacter cloacae/genética , Escherichia coli/genética , Testes de Sensibilidade Microbiana , Plasmídeos/genética , beta-Lactamases/genética
13.
Cell ; 185(16): 3008-3024.e16, 2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35870449

RESUMO

Here, we report inducible mosaic animal for perturbation (iMAP), a transgenic platform enabling in situ CRISPR targeting of at least 100 genes in parallel throughout the mouse body. iMAP combines Cre-loxP and CRISPR-Cas9 technologies and utilizes a germline-transmitted transgene carrying a large array of individually floxed, tandemly linked gRNA-coding units. Cre-mediated recombination triggers expression of all the gRNAs in the array but only one of them per cell, converting the mice to mosaic organisms suitable for phenotypic characterization and also for high-throughput derivation of conventional single-gene perturbation lines via breeding. Using gRNA representation as a readout, we mapped a miniature Perturb-Atlas cataloging the perturbations of 90 genes across 39 tissues, which yields rich insights into context-dependent gene functions and provides a glimpse of the potential of iMAP in genome decoding.


Assuntos
Sistemas CRISPR-Cas , RNA Guia , Animais , Sistemas CRISPR-Cas/genética , Edição de Genes , Genoma , Camundongos , RNA Guia/genética , RNA Guia/metabolismo , Transgenes
14.
Artigo em Inglês | MEDLINE | ID: mdl-35830498

RESUMO

As a device for direct conversion of chemical energy into electrical energy, the solid oxide fuel cell (SOFC) contributes positively to the sustainable development strategy. However, the commercialization of fuel cells is still impeded by severe cathode degradation caused by its limited stability at operating temperatures and being prone to Cr-poisoning from Cr-containing alloy interconnectors commonly used in these cells. This paper reports the development of a high-durability Ba-doped LSCF(La0.6Sr0.4Co0.2Fe0.8O3-δ) cathode material under realistic fuel cell operating conditions in the presence of the Cr alloy. In particular, when tested in a symmetrical cell constructed of Ba-doped LSCF, the polarization resistance of the cell remains very low at 0.06 Ω cm2 after being tested at 800 °C for 120 h exposed to Cr in 3% humidified air. In contrast, for the undoped LSCF under the same testing conditions, the polarization resistance of the cell increases ∼10 times from 0.22 Ω cm2 of the pristine cell to 2.18 Ω cm2 after Cr-exposure testing. Furthermore, when tested in an anode-supported complete cell as a cathode under typical SOFC operation conditions at 750 °C, the cell with the Ba-doped LSCF cathode displays significantly low degradation rates of 0.00056% h-1 (without Cr) and 0.00310% h-1 (with Cr); both are much lower than that of the cell using the undoped LSCF cathode (0.00124% h-1 without Cr and 0.01082% h-1 with Cr). This enhanced durability and Cr-tolerance exhibited by the Ba-doped LSCF cathode stem from its higher crystal structure stability and improved chemical resistance compared to undoped LSCF.

15.
Neuroreport ; 33(11)2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35776939

RESUMO

The secondary injury plays a vital role in the development of spinal cord injury (SCI), which is characterized by the occurrence of oxidative stress, neuronal apoptosis, and inflammatory response. Notoginsenoside R1 (NGR1) has been involved in the modulation of antioxidative stress and anti-inflammatory response. However, its roles in SCI-induced injury are still unknown. We explored the therapeutic effect of NGR1 and its underlying mechanism after SCI by using behavioral, biochemical, and immunohistochemical techniques. The administration of NGR1 after SCI enhanced the neurological function, and mitigated tissue damage and motor neuron loss than those in SCI + vehicle group. Meanwhile, significantly increased expression of Nrf2 protein and HO-1 protein was found in the SCI + NGR1 group compared with those in the SCI + vehicle group. In addition, the inhibitory effects of oxidative stress, apoptotic neuron ratio, and neuronal inflammation in the SCI + NGR1 group can be partially reversed when the Nrf2/HO-1 signaling pathway was inhibited by ML385. Our results indicate that the administration of NGR1 can attenuate oxidative stress, neuronal apoptosis, and inflammation by activating the Nrf2/HO-1 signaling pathway after SCI, thereby improving neurological function.


Assuntos
Ginsenosídeos , Fator 2 Relacionado a NF-E2 , Traumatismos da Medula Espinal , Apoptose/efeitos dos fármacos , Ginsenosídeos/farmacologia , Heme Oxigenase-1/metabolismo , Humanos , Inflamação/induzido quimicamente , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Transdução de Sinais/efeitos dos fármacos , Traumatismos da Medula Espinal/metabolismo
16.
Ann Surg ; 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35781462

RESUMO

OBJECTIVE: To assess the safety and efficacy of antimicrobial peptide PL-5 (Peceleganan) spray in the treatment of wound infections. BACKGROUND: Antimicrobial peptide PL-5 spray is a novel topical antimicrobial agent. METHODS: We conducted a multicenter, open-label, randomized, controlled phase IIb clinical trial to evaluate the efficacy and safety of PL-5 spray, as compared with silver sulfadiazine, in patients with skin wound infections. The primary efficacy outcome was the clinical efficacy rate on the first day after ending the treatment (D8). The secondary efficacy outcome was the clinical efficacy rate on the fifth day posttreatment (D5), the bacteria clearance rate, and the overall efficacy rate at the mentioned 2 time points. The safety outcomes included adverse reactions and pharmacokinetic analysis posttreatment. RESULTS: A total of 220 patients from 27 hospitals in China were randomly assigned to 4 groups. On D8, the efficacy rate was 100.0%, 96.7%, 96.7% for the 1‰ PL-5, 2‰ PL-5, 4‰ PL-5 groups, respectively, as compared with 87.5% for the control group. The efficacy rate among the 4 groups was significantly different (P<0.05). On D5, the efficacy rate was 100.0%, 93.4%, 98.3% for the 1‰ PL-5, 2‰ PL-5, 4‰ PL-5 groups, respectively, as compared with 82.5% for the control group. The efficacy rate among the 4 groups was significantly different (P<0.05). The blood concentration of PL-5 was not detectable in pharmacokinetic analysis. No severe adverse event related to the application of PL-5 was reported. CONCLUSIONS: Antimicrobial peptide PL-5 spray is safe and effective for the treatment of skin wound infections. TRIAL REGISTRATION: ChiCTR2000033334.

17.
Front Chem ; 10: 964128, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35898969

RESUMO

The catalytic conversion of ethyl levulinate (EL) to γ-valerolactone (GVL) is an important intermediate reaction in the conversion and utilization of biomass resources. The development of novel and efficient catalysts is significantly important for this reaction. In this work, using the biomass-derived tannic acid as carbon precursor and the transition metal cobalt as active component, a novel tannic acid carbon supported cobalt catalyst (Co/TAC) was prepared by pyrolysis and subsequent hydrazine hydrate reduction method. The hydrogenation of EL and other carbonyl compounds by hydrogen transfer reaction was used to evaluate the performance of the catalysts. The effects of different preparation and reaction conditions on the performance of the catalysts were investigated, and the structures of the prepared catalysts were characterized in detail. The results showed that the carbonization temperature of the support had a significant effect on the activity of the catalyst for the reaction. Under the optimized conditions, the Co/TAC-900 catalyst obtained the highest GVL yield of 91.3% under relatively mild reaction conditions. Furthermore, the prepared catalyst also showed high efficiency for the hydrogenation of various ketone compounds with different structures. This work provides a new reference for the construction of the catalysts during the conversion of biomass and a potential pathway for the high-value utilization of tannin resource.

18.
Mol Pain ; 18: 17448069221111158, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35712881

RESUMO

Can mice recognize themselves in a mirror? The answer is unclear. Previous studies have reported that adult mice - when shown itch-like videos - demonstrated itch empathy. However, this was proven to be unreproducible in other studies. In the present study, we wanted to examine whether adult mice were able to recognize their mirror image. In our testing, we found that mice spent more time in the central area in an open field with mirrors surrounding the chamber than those in a normal open field. In a similar open field test with four mice placed in four directions, mice showed similar behavioral responses to those with mirrors. These results indicate that mice are able to recognize images in the mirror, however, they cannot distinguish their own mirror images from the mirror images of other mice. To repeat the experiments of itch empathy, we compared the itch responses of mice in the mirrored environment, to those without. No significant difference in itching responses was detected. Differently, in the case of chemical pain (formalin injection), animals' nociceptive responses to formalin during Phase II were significantly enhanced in the mirrored open field. A new format of heat map was developed to help the analysis of the trace of mice in the open field. Our results suggest that mice do recognize the presence of mice in the mirror, and their nociceptive - but not itch - responses are enhanced.


Assuntos
Nociceptividade , Prurido , Animais , Comportamento Animal , Formaldeído , Camundongos , Dor
19.
Nat Commun ; 13(1): 3217, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35680926

RESUMO

Growing threats from extreme climatic events and biodiversity loss have raised concerns about their interactive consequences for ecosystem functioning. Evidence suggests biodiversity can buffer ecosystem functioning during such climatic events. However, whether exposure to extreme climatic events will strengthen the biodiversity-dependent buffering effects for future generations remains elusive. We assess such transgenerational effects by exposing experimental grassland communities to eight recurrent summer droughts versus ambient conditions in the field. Seed offspring of 12 species are then subjected to a subsequent drought event in the glasshouse, grown individually, in monocultures or in 2-species mixtures. Comparing productivity between mixtures and monocultures, drought-selected plants show greater between-species complementarity than ambient-selected plants when recovering from the subsequent drought, causing stronger biodiversity effects on productivity and better recovery of drought-selected mixtures after the drought. These findings suggest exposure to recurrent climatic events can improve ecosystem responses to future events through transgenerational reinforcement of species complementarity.


Assuntos
Secas , Ecossistema , Biodiversidade , Pradaria , Plantas , Estações do Ano
20.
Artigo em Inglês | MEDLINE | ID: mdl-35657022

RESUMO

Regulating the electronic structure of MoS2 by constructing cationic vacancies is an effective method to activate and improve its intrinsic properties. Herein, we synthesize the MoS2-based composite with abundant single atomic Mo cation vacancies through uniformly loading nickel-cobalt-Prussian blue analogues (NiCoPBA) (NiCoPBA-MoS2-VMo) by immersing a single Ni atom-decorated MoS2 (Ni-MoS2) into K3[Co(CN)6] solution. Subsequently, NiCoP-MoS2-VMo with improved conductivity is obtained by phosphating the composite as a high-efficiency hydrogen evolution reaction (HER) catalyst. Experiments and theoretical calculations indicate that the electrons of NiCoP are spontaneously transferred to the substrate MoS2-VMo nanosheets in NiCoP-MoS2-VMo, and the moderately oxidized NiCoP is beneficial to the adsorption of OH*. Meanwhile, the mono-atomic Mo cation vacancies of the catalyst modulate the electronic structure of S, optimizing the adsorption of hydrogen in the reaction process. Therefore, NiCoP-MoS2-VMo has enhanced chemical adsorption for H* (on MoS2-VMo) and OH*(on NiCoP), expediting the water-splitting step and HER catalysis, and benefiting from the regulation of the electronic structure induced by the construction of metallic Mo vacancies in MoS2, the as-prepared catalyst displays an overpotential of only 67 mV at 10 mA cm-2 with long-term stability (no current decay over 20 h). This work affords not only a kind of efficient HER catalysts but also a new valuable route for developing inexpensive and high-performance catalysts with single atomic cation vacancies.

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