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1.
Osteoporos Int ; 35(5): 759-773, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38224388

RESUMO

This study reviewed the risk factors of Osteosarcopenic obesity (OSO), a condition linking weak bones, muscle loss, and obesity. Notable associations were found with female gender, physical inactivity, hypertension, and frailty. Recognizing these early can aid targeted prevention, emphasizing further research for improved understanding and strategies. PURPOSE: Osteosarcopenic obesity (OSO) represents a confluence of osteopenia/osteoporosis, sarcopenia, and obesity, contributing to increased morbidity and mortality risks. Despite escalating prevalence, its risk factors remain under-explored, necessitating this comprehensive systematic review and meta-analysis. METHODS: A diligent search of PubMed, Scopus, and Cochrane databases was conducted for pertinent studies until June 2023. The random-effects model was employed to compute pooled odds ratios (ORs) and 95% confidence intervals (CIs), scrutinizing various risk factors like age, gender, lifestyle factors, and common comorbidities. RESULTS: Our meta-analysis incorporated 21 studies comprising 178,546 participants. We identified significant associations between OSO and factors such as female gender (OR 1.756, 95% CI 1.081 to 2.858), physical inactivity (OR 1.562, 95% CI 1.127-2.165), and hypertension (OR 1.482, 95% CI 1.207-1.821). Conversely, smoking (OR 0.854, 95% CI 0.672-1.084), alcohol consumption (OR 0.703, 95% CI 0.372-1.328), and dyslipidemia (OR 1.345, 95% CI 0.982-1.841) showed no significant associations. Remarkable heterogeneity was observed across studies, indicating considerable variation in effect sizes. Notably, OSO was strongly associated with frailty (OR 6.091; 95% CI 3.576-10.375). CONCLUSIONS: Our study underscored the substantial role of female gender, physical inactivity, and hypertension in the development of OSO, whilst suggesting a strong link between OSO and frailty. These findings emphasize the importance of early risk factor identification and targeted interventions in these groups. Further research is warranted to decode the complex pathophysiological interplay and devise effective prevention and management strategies.


Assuntos
Fragilidade , Hipertensão , Sarcopenia , Humanos , Feminino , Obesidade/complicações , Obesidade/epidemiologia , Fatores de Risco , Hipertensão/complicações , Hipertensão/epidemiologia , Estilo de Vida
2.
Inorg Chem ; 63(12): 5727-5733, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38470094

RESUMO

Nickel-rich layered oxides are envisaged as one of the most promising alternative cathode materials for lithium-ion batteries, considering their capabilities to achieve ultrahigh energy density at an affordable cost. Nonetheless, with increasing Ni content in the cathodes comes a severe extent of Ni4+ redox side reactions on the interface, leading to fast capacity decay and structural stability fading over extended cycles. Herein, dual additives of bis(vinylsulfonyl)methane (BVM) and lithium difluorophosphate (LiDFP) are adopted to synergistically generate the F-, P-, and S-rich passivation layer on the cathode, and the Ni4+ activity and dissolution at high voltage are restricted. The sulfur-rich layer formed by the polymerization of BVM, combined with the Li3PO4 and LiF phases derived from LiDFP, alleviates the problems of increased impedance, cracks, and an irreversible H2-H3 phase transition. Consequently, the Ni-rich LiNixM1-xO2 (x > 0.95) button half-cell cycled in LiDFP + BVM electrolyte exhibits a significant discharging capacity of 181.4 mAh g-1 at 1 C (1 C = 200 mA g-1) with retention of 83.7% after 100 cycles, surpassing the performance of the commercial electrolyte (160.7 mAh g-1) with retention of 53.3%. Remarkably, the NCM95||graphite pouch cell exhibits a remarkable capacity retention of 95.5% after 200 cycles. This work inspires the rational design of electrolyte additives for ultrahigh-energy batteries with nickel-rich layered oxide cathodes.

3.
Nature ; 560(7718): 331-335, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30069045

RESUMO

Eukaryotic genomes are generally organized in multiple chromosomes. Here we have created a functional single-chromosome yeast from a Saccharomyces cerevisiae haploid cell containing sixteen linear chromosomes, by successive end-to-end chromosome fusions and centromere deletions. The fusion of sixteen native linear chromosomes into a single chromosome results in marked changes to the global three-dimensional structure of the chromosome due to the loss of all centromere-associated inter-chromosomal interactions, most telomere-associated inter-chromosomal interactions and 67.4% of intra-chromosomal interactions. However, the single-chromosome and wild-type yeast cells have nearly identical transcriptome and similar phenome profiles. The giant single chromosome can support cell life, although this strain shows reduced growth across environments, competitiveness, gamete production and viability. This synthetic biology study demonstrates an approach to exploration of eukaryote evolution with respect to chromosome structure and function.


Assuntos
Cromossomos Artificiais de Levedura/genética , Engenharia Genética/métodos , Aptidão Genética/genética , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Biologia Sintética/métodos , Fusão Gênica Artificial/métodos , Centrômero/genética , Evolução Molecular , Meiose , Viabilidade Microbiana/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Esporos Fúngicos/genética , Telômero/genética , Transcriptoma
4.
Acta Biochim Biophys Sin (Shanghai) ; 56(2): 315-322, 2024 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273782

RESUMO

SRP14 is a crucial protein subunit of the signal recognition particle (SRP), a ribonucleoprotein complex essential for co-translational translocation to the endoplasmic reticulum. During our investigation of SRP14 expression across diverse cell lines, we observe variations in its migration on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), with some cells exhibiting slower migration and others migrating faster. However, the cause of this phenomenon remains elusive. Our research rules out alternative splicing as the cause and, instead, identifies the presence of a P124A mutation in SRP14 (SRP14 P124A) among the faster-migrating variants, while the slower-migrating variants lack this mutation. Subsequent ectopic expression of wild-type SRP14 P124 or SRP14 WT and SRP14 P124A in various cell lines confirms that the P124A mutation indeed leads to faster migration of SRP14. Further mutagenesis analysis shows that the P117A and A121P mutations within the alanine-rich domain at the C-terminus of SRP14 are responsible for migration alterations on SDS-PAGE, whereas mutations outside this domain, such as P39A, Y27F, and T45A, have no such effect. Furthermore, the ectopic expression of SRP14 WT and SRP14 P124A yields similar outcomes in terms of SRP RNA stability, cell morphology, and cell growth, indicating that SRP14 P124A represents a natural variant of SRP14 and retains comparable functionality. In conclusion, the substitution of proline for alanine in the alanine-rich tail of SRP14 results in faster migration on SDS-PAGE, but has little effect on its function.


Assuntos
Alanina , Partícula de Reconhecimento de Sinal , Partícula de Reconhecimento de Sinal/genética , Partícula de Reconhecimento de Sinal/metabolismo , Mutação , Mutagênese , Eletroforese em Gel de Poliacrilamida , Alanina/genética
5.
Nano Lett ; 23(22): 10148-10156, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37922398

RESUMO

Dendrite growth and corrosion of Zn metal anodes result in the limited reversibility of aqueous Zn metal batteries (ZMBs), hindering their prospects as large-scale energy storage devices. Inspired by the similarity of conventional electroplating industrial engineering and Zn deposition in ZMBs, we tend to utilize a low-cost leveling agent (LEA), 1,4-butynediol, to level the Zn deposition. Combining theoretical with in situ experimental characterizations, the preferential adsorption of LEA molecules on different lattice planes can contribute to crystallographic orientation manipulation of the (002) plane, causing good inhibition of dendrite growth. Additionally, the adsorption of LEA molecules on the Zn surface can also prevent undesirable corrosion. Endowed with these merits, symmetric cells and full cells with the LEA additive achieve improved stability and reversibility. This work provides new inspiration for introducing traditional electroplating additives into high-performance ZMBs and gives researchers a direction for choosing electrolyte additives, which also has potential to be applied to other metal anodes.

6.
Nano Lett ; 23(8): 3181-3188, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37036714

RESUMO

Sluggish desolvation in extremely cold environments caused by strong Li+-dipole interactions is a key inducement for the capacity decline of a battery. Although the Li+-dipole interaction is reduced by increasing the electrolyte concentration, its high viscosity inevitably limits ion transfer at low temperatures. Herein, Li+-dipole interactions were eliminated to accelerate the migration rate of ions in electrolytes and at the electrode interface via designing Li+-anion nanometric aggregates (LA-nAGGs) in low-concentration electrolytes. Li+ coordinated by TFSI- and FSI- anions instead of a donor solvent promotes the formation of an inorganic-rich interfacial layer and facilitates Li+ transfer. Consequently, the LA-nAGG-type electrolyte demonstrated a high ionic conductivity (0.6 mS cm-1) at -70 °C and a low activation energy of charge transfer (38.24 kJ mol-1), enabling Li||NiFe-Prussian blue derivative cells to deliver ∼83.1% of their room-temperature capacity at -60 °C. This work provides an advanced strategy for the development of low-temperature electrolytes.

7.
Nano Lett ; 23(4): 1135-1143, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36779620

RESUMO

Aqueous Zn metal batteries have attracted extensive attention due to their intrinsic advantages. However, zinc ions tend to deposit irregularly, seriously depleting the capacity and stability of the battery. The construction of zincophilic sites can effectively regulate the nucleation and growth of Zn, but there is a defect that these sites will be covered with gradual failure after long-term cycling. Here, in combination with the sustained-compensated strategy, interfacial zincophilic sites are continuously constructed, thus effectively avoiding the threat of dendrites and improving the electrochemical performance. Impressively, at 10 mA cm-2 and 5 mAh cm-2, the protected Zn metal exhibits excellent cycling stability over 2000 cycles in the Zn//Zn battery. Moreover, even the cathode mass loading is considerably high (35 mg cm-2), and the Zn//NVO full cell significantly outperforms with high areal capacity (up to 4 mAh cm-2). This novel strategy provides a direction for the development of high-capacity aqueous batteries.

8.
Angew Chem Int Ed Engl ; 63(20): e202320258, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38456300

RESUMO

Large-scale energy storage devices play pivotal roles in effectively harvesting and utilizing green renewable energies (such as solar and wind energy) with capricious nature. Biphasic self-stratifying batteries (BSBs) have emerged as a promising alternative for grid energy storage owing to their membraneless architecture and innovative battery design philosophy, which holds promise for enhancing the overall performance of the energy storage system and reducing operation and maintenance costs. This minireview aims to provide a timely review of such emerging energy storage technology, including its fundamental design principles, existing categories, and prototype architectures. The challenges and opportunities of this undergoing research topic will also be systematically highlighted and discussed to provide guidance for the subsequent R&D of superior BSBs while conducive to bridging the gap for their future practical application.

9.
Biochem J ; 479(23): 2433-2447, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36416748

RESUMO

The KEOPS complex is an evolutionarily conserved protein complex in all three domains of life (Bacteria, Archaea, and Eukarya). In budding yeast Saccharomyces cerevisiae, the KEOPS complex (ScKEOPS) consists of five subunits, which are Kae1, Bud32, Cgi121, Pcc1, and Gon7. The KEOPS complex is an ATPase and is required for tRNA N6-threonylcarbamoyladenosine modification, telomere length maintenance, and efficient DNA repair. Here, recombinant ScKEOPS full complex and Kae1-Pcc1-Gon7 and Bud32-Cgi121 subcomplexes were purified and their biochemical activities were examined. KEOPS was observed to have ATPase and GTPase activities, which are predominantly attributed to the Bud32 subunit, as catalytically dead Bud32, but not catalytically dead Kae1, largely eliminated the ATPase/GTPase activity of KEOPS. In addition, KEOPS could hydrolyze ADP to adenosine or GDP to guanosine, and produce PPi, indicating that KEOPS is an ADP/GDP nucleotidase. Further mutagenesis characterization of Bud32 and Kae1 subunits revealed that Kae1, but not Bud32, is responsible for the ADP/GDP nucleotidase activity. In addition, the Kae1V309D mutant exhibited decreased ADP/GDP nucleotidase activity in vitro and shortened telomeres in vivo, but showed only a limited defect in t6A modification, suggesting that the ADP/GDP nucleotidase activity of KEOPS contributes to telomere length regulation.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/metabolismo , Difosfato de Adenosina/metabolismo , GTP Fosfo-Hidrolases/metabolismo
10.
Int J Qual Health Care ; 35(3)2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37417461

RESUMO

Since the public long-term care insurance (LTCI) system was piloted in Chengdu, China, in October 2017, there has been considerable growth of LTC institutions in China. This study aimed to evaluate the health value effect of LTCI in older patients with severe disabilities in an LTC institution. This prospective study was based on data from 985 severe disability patients with or without LTCI from October 2017 to May 2021 in the Eighth People's Hospital, Chengdu, China. The Cox proportional hazard model estimated LTCI's health value, including survival probability and risk of pneumonia/pressure ulcers. Subgroup analysis was performed for sex, age, Charlson Comorbidity Index (CCI), and the number of drugs. In the analysis, 519 and 466 patients in LTCI and non-LTCI groups were included, respectively. In adjusted Cox analyses, the LTCI group had a significantly elevated survival rate compared with the non-LTCI groups at 12 months (P < .001, hazard ratio (HR) = 1.758, 95% confidence interval (CI) 1.300-2.376). At 40 months, the adjusted survival rate was 62.6% in the LTCI group, which was significantly higher (53.7%; P = .003, HR = 1.438, 95% CI 1.131-1.831). The subgroups of patients aged 60 to 79 years (interaction P = .007) and with CCI ≥ 3 (interaction P = .026) were more significantly associated with survival improvement than those aged >80 years and with CCI< 3. The LTCI group was also at lower risk for hospital-acquired pneumonia (P = .016, HR 0.622, 95% CI 0.422-0.917) and pressure ulcers (P = .008, HR 0.695, 95% CI 0.376-0.862). The improved survival of LTCI remained stable in sensitivity analyses. For older patients with severe disabilities, in a LTC institution, LTCI significantly improved their health profile and longevity after a year, suggesting the large role and development potentiality of institution care in the LTCI system of China.


Assuntos
Seguro de Assistência de Longo Prazo , Úlcera por Pressão , Humanos , Idoso , Estudos Prospectivos , China , Avaliação de Resultados em Cuidados de Saúde , Assistência de Longa Duração
11.
Nano Lett ; 22(8): 3473-3479, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35426684

RESUMO

The key to enabling high energy density of organic energy-storage systems is the development of high-voltage organic cathodes; however, the redox voltage (<4.0 V vs Li/Li+) of state-of-the-art organic electrode materials (OEMs) remains unsatisfactory. Herein, we propose a novel dibromotetraoxapentacene (DBTOP) redox center to surpass the redox potential limit of OEMs, achieving ultrahigh discharge plateaus of approximately 4.4 V (vs Li+/Li). As theoretically analyzed, electron delocalization between dioxin active centers and benzene rings as well as electron-withdrawing bromine atoms endows the molecule with a low occupied molecular orbital level by diluting the electron density of dioxin in the whole p-π conjugated skeleton, and the strong π-π interactions among the DBTOP molecules provide a faster electrochemical kinetic pathway. This tetraoxapentacene redox center makes the working voltage of OEMS closer to the high-voltage inorganic electrodes, and its chemical and structural tunability may stimulate the further development of high-voltage organic cathodes.


Assuntos
Dioxinas , Eletrodos , Elétrons , Lítio/química , Oxirredução
12.
Nano Lett ; 22(7): 2898-2906, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35353004

RESUMO

The practical application of aqueous high-rate Zn metal battery (ZMB) is limited due to accelerated dendrite formation at high current densities. It is urgent to find an electrolyte, which could not only be mechanically stiff to clamp down dendrites but also not sacrifice ionic conductivity and interfacial compatibility. Herein, a new type of dynamically "solid-liquid" interconvertible electrolyte based on non-Newtonian fluid (NNFE) is proposed. Liquidity characteristic of NNFE is favorable for electrochemical kinetics and interfacial compatibility. Furthermore, in an area with high current rate NNFE would respond and mechanically stiffen to dissuade localized increase in Zn dendrite growth. Even at a current density of 50 mA cm-2, NNFE enables reversible and stable operation of a Zn symmetrical cell over 20 000 cycles. For Zn//Na5V12O32 (NVO) full cell, the NNFE also realizes lengthy cycling for 5000 periods at 5 A g-1. This research opens up new inspirations to high-rate Zn metal even other metal batteries.

13.
J Med Virol ; 94(6): 2317-2330, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35174515

RESUMO

Pooled data from 2352 hospitalized coronavirus disease 2019 (COVID-19) patients with viral RNA in feces across 46 studies were analyzed and the pooled prevalence of fecal RNA was 46.8% (95% confidence interval [CI]: 0.383-0.554). The pooled analysis showed that the occurrence of total gastrointestinal (GI) symptoms was 28.5% (95% CI: 0.125-0.44) in COVID-19 patients with fecal RNA, that of both respiratory and GI symptoms was 21.9% (95% CI: 0.09-0.346), that of only GI symptoms was 19.8% (95% CI: 0.107-0.288), and that of only respiratory symptoms was 50.5%(95% CI: 0.267-0.744). The pooled data showed no significant difference in positive fecal RNA between severe and nonsevere cases (odds ratio = 2.009, p = 0.079, 95% CI: 0.922-4.378). During hospital admission, after samples from the respiratory system tested negative for viral RNA, 55.4% (95% CI: 0.418-0.669) of the patients with positive fecal RNA had persistent shedding of fecal RNA and pooled results from the other 4 studies including 848 discharged patients with nucleic acid-negative stool samples indicated that the occurrence of repositive stool swabs was 18.1% (95% CI: 0.028-0.335), that of repositive respiratory swabs was 22.8% (95% CI: 0.003-0.452), that of both repositive stool and respiratory swabs was 19.1% (95% CI: 0.019-0.363), and that of only repositive stool swabs was 9.6% (95% CI: 0.010-0.203). The digestive tract may be an important organ involved in COVID-19 infection and in the excretion of the virus. Because of the potential risk of fecal-oral transmission, giving emphasis on stool swab tests can help increase the detection rate of asymptomatic carriers and reduce missed diagnoses.


Assuntos
COVID-19 , Gastroenteropatias , COVID-19/diagnóstico , Fezes , Humanos , RNA Viral/genética , SARS-CoV-2/genética
14.
Nucleic Acids Res ; 48(22): 12792-12803, 2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33270890

RESUMO

Telomeres at the ends of eukaryotic chromosomes are essential for genome integrality and stability. In order to identify genes that sustain telomere maintenance independently of telomerase recruitment, we have exploited the phenotype of over-long telomeres in the cells that express Cdc13-Est2 fusion protein, and examined 195 strains, in which individual non-essential gene deletion causes telomere shortening. We have identified 24 genes whose deletion results in dramatic failure of Cdc13-Est2 function, including those encoding components of telomerase, Yku, KEOPS and NMD complexes, as well as quite a few whose functions are not obvious in telomerase activity regulation. We have characterized Swc4, a shared subunit of histone acetyltransferase NuA4 and chromatin remodeling SWR1 (SWR1-C) complexes, in telomere length regulation. Deletion of SWC4, but not other non-essential subunits of either NuA4 or SWR1-C, causes significant telomere shortening. Consistently, simultaneous disassembly of NuA4 and SWR1-C does not affect telomere length. Interestingly, inactivation of Swc4 in telomerase null cells accelerates both telomere shortening and senescence rates. Swc4 associates with telomeric DNA in vivo, suggesting a direct role of Swc4 at telomeres. Taken together, our work reveals a distinct role of Swc4 in telomere length regulation, separable from its canonical roles in both NuA4 and SWR1-C.


Assuntos
Adenosina Trifosfatases/genética , Histona Acetiltransferases/genética , Proteínas de Saccharomyces cerevisiae/genética , Homeostase do Telômero/genética , Cromatina/genética , Proteínas de Ligação a DNA/genética , Regulação Fúngica da Expressão Gênica/genética , Histonas/genética , Humanos , Complexos Multiproteicos/genética , Saccharomyces cerevisiae/genética , Telomerase/genética , Telômero/genética , Proteínas de Ligação a Telômeros/genética
15.
Nano Lett ; 21(12): 5021-5027, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34078078

RESUMO

Effective recycling of spent Li metal anodes is an urgent need for energy/resource conservation and environmental protection, making Li metal batteries more affordable and sustainable. For the first time, we explore a unique sustainable healable lithium alloy anode inspired by the intrinsic healing ability of liquid metal. This lithium alloy anode can transform back to the liquid state through Li-completed extraction, and then the structure degradation generated during operation could be healed. Therefore, an ultralong cycle life of more than 1300 times can be successfully realized under harsh conditions of 5 mA h cm-2 capacitance by a process of two healing behaviors. This design improves the sustainable utilization of Li metal to a great extent, bringing about unexpected effects in the field of lithium-based anodes even at an unprecedentedly high discharge current density (up to 25 mA cm-2) and capacity (up to 50 mA h cm-2).

16.
Nucleic Acids Res ; 47(11): 5684-5697, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-30937455

RESUMO

KEOPS complex is one of the most conserved protein complexes in eukaryotes. It plays important roles in both telomere uncapping and tRNA N6-threonylcarbamoyladenosine (t6A) modification in budding yeast. But whether KEOPS complex plays any roles in DNA repair remains unknown. Here, we show that KEOPS complex plays positive roles in both DNA damage response and homologous recombination-mediated DNA repair independently of its t6A synthesis function. Additionally, KEOPS displays DNA binding activity in vitro, and is recruited to the chromatin at DNA breaks in vivo, suggesting a direct role of KEOPS in DSB repair. Mechanistically, KEOPS complex appears to promote DNA end resection through facilitating the association of Exo1 and Dna2 with DNA breaks. Interestingly, inactivation of both KEOPS and Mre11/Rad50/Xrs2 (MRX) complexes results in synergistic defect in DNA resection, revealing that KEOPS and MRX have some redundant functions in DNA resection. Thus we uncover a t6A-independent role of KEOPS complex in DNA resection, and propose that KEOPS might be a DSB sensor to assist cells in maintaining chromosome stability.


Assuntos
DNA Helicases/fisiologia , DNA Fúngico , Exodesoxirribonucleases/fisiologia , Recombinação Homóloga , Reparo de DNA por Recombinação , Proteínas de Saccharomyces cerevisiae/fisiologia , Ligação Competitiva , Cromatina/química , DNA/química , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , Endodesoxirribonucleases/metabolismo , Exodesoxirribonucleases/metabolismo , Metaloendopeptidases/metabolismo , Mutação , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Telômero/metabolismo , Fatores de Transcrição/metabolismo
17.
Nanotechnology ; 31(31): 315401, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32299078

RESUMO

Carbon material doped with nitrogen and transition metal is a kind of promising candidate of the platinum for oxygen reduction reaction (ORR) process due to its low cost, efficiency and stability. Here we demonstrate an original type of Fe/N/C catalyst based on pore-in-pore structures (P-P Fe/N/C), showing one of the highest oxygen reduction reaction performances among all reported Fe/N/C-type catalysts (onset potential of 0.995 V, half-wave potential of 0.881 V vs. RHE with a relatively low mass loading of 0.32 mg cm-2 and long-term durability (97% relative current in 60 000 s operation) in alkaline media. Such outstanding performances can be ascribed to the efficient active sites activated by the encapsulated atomic and subnanoscale iron, and great exposure of these active sites due to the unique pore-in-pore hierarchical construction. Once assembled in lithium-O2 batteries, a specific capacity of 7250 mA h g-1 at 70 mA g-1 can be obtained by the P-P Fe/N/C catalyst. Moreover, upon cycling, the P-P Fe/N/C electrode can be cycled 150 times with no capacity loss, which is much longer than six cycles of pure Super P air electrode. These results evidently reveal the developed Fe/N/C catalyst holds great promise to serve as an alternative to the conventional Pt-based noble metal catalysts.

18.
Nano Lett ; 19(5): 3066-3073, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-30951633

RESUMO

Lithium-metal batteries (LMB) are very attractive owing to their high theoretical energy density, but significant challenges such as low ionic conductivity and safety risks prevent their widespread application. Herein, we report a new design of high-safety all-solid-state LMB by using high-ionic-conductivity thermoresponsive solid-polymer electrolyte (TSPE), providing a smart and active approach to realize thermally induced autonomic shutdown of LMBs by efficiently inhibiting the ionic conduction between electrodes beyond an unsafe temperature. The as-obtained TSPE exhibits a high ionic conductivity (2 × 10-4 S cm-1 at 30 °C), which enables a significantly improved capacity of 160 mA h g-1 at 0.2 C and outstanding high rate capability up to 5 C as well as a super-long cycle life of over 400 cycles for the constructed all-solid-state Li||LiFePO4 batteries. The present study opens up a new avenue for the fabrication of self-protective all-solid-state batteries with inherent intelligent thermal management to ensure battery-series safety.

19.
Nucleic Acids Res ; 45(6): 3308-3322, 2017 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-28180293

RESUMO

Rad6 and Bre1, ubiquitin-conjugating E2 and E3 enzymes respectively, are responsible for histone H2B lysine 123 mono-ubiquitination (H2Bub1) in Saccharomyces cerevisiae. Previous studies have shown that Rad6 and Bre1 regulate telomere length and recombination. However, the underlying molecular mechanism remains largely unknown. Here we report that H2BK123 mutation results in telomere shortening, while inactivation of Ubp8 and/or Ubp10, deubiquitinases of H2Bub1, leads to telomere lengthening in Rad6-Bre1-dependent manner. In telomerase-deficient cells, inactivation of Rad6-Bre1 pathway retards telomere shortening rate and the onset of senescence, while deletion of UBP8 and/or UBP10 accelerates senescence. Thus, Rad6-Bre1 pathway regulates both telomere length and recombination through its role in H2Bub1. Additionally, inactivation of both Rad6-Bre1-H2Bub1 and Mre11-Rad50-Xrs2 (MRX) pathways causes synthetic growth defects and telomere shortening in telomerase-proficient cells, and significantly accelerates senescence and eliminates type II telomere recombination in telomerase-deficient cells. Furthermore, RAD6 or BRE1 deletion, or H2BK123R mutation decreases the accumulation of ssDNA at telomere ends. These results support the model that Rad6-Bre1-H2Bub1 cooperates with MRX to promote telomere-end resection and thus positively regulates both telomerase- and recombination-dependent telomere replication. This study provides a mechanistic link between histone H2B ubiquitination and telomere replication.


Assuntos
Histonas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Homeostase do Telômero , Telômero/metabolismo , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitinação , DNA de Cadeia Simples/metabolismo , Endopeptidases/metabolismo , Deleção de Genes , Viabilidade Microbiana , Proteínas Nucleares/metabolismo , Recombinação Genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/genética , Encurtamento do Telômero , Proteínas de Ligação a Telômeros/genética , Ubiquitina Tiolesterase/metabolismo , Enzimas de Conjugação de Ubiquitina/antagonistas & inibidores , Enzimas de Conjugação de Ubiquitina/genética
20.
Nano Lett ; 18(7): 4598-4605, 2018 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-29856925

RESUMO

Lithium metal batteries have attracted increasing attention recently due to their particular advantages in energy density. However, as for their practical application, the development of solid-state lithium metal batteries is restricted because of the poor Li/electrolyte interface, low Li-ion conductivity, and irregular growth of Li dendrites. To address the above issues, we herein report a high Li-ion conductivity and compatible polymeric interfacial layer by grafting tween-20 on active lithium metal. Sequential oxyethylene groups in tween-grafted Li (TG-Li) improve the ion conductivity and the compatibility of the Li/electrolyte interface, which enables low overpotentials and stable performance over 1000 cycles. Consequently, the poly(ethylene oxide)-based solid-state lithium-sulfur battery with TG-Li exhibits a high reversible capacity of 1051.2 mA h g-1 at 0.2 C (1 C = 1675 mA h g-1) and excellent stability for 500 cycles at 2 C. The decreasing concentration of the sulfur atom with increasing Ar+ sputtering depth indicates that the polymer interfacial layer works well in suppressing polysulfide reduction to Li2S/Li2S2 on the metallic Li surface even after long-term cycling.

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