Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
Add more filters











Publication year range
1.
Nat Commun ; 15(1): 8431, 2024 Sep 29.
Article in English | MEDLINE | ID: mdl-39343779

ABSTRACT

Construction of a solid electrolyte interphase (SEI) of zinc (Zn) electrode is an effective strategy to stabilize Zn electrode/electrolyte interface. However, single-layer SEIs of Zn electrodes undergo rupture and consequent failure during repeated Zn plating/stripping. Here, we propose the construction of a robust bilayer SEI that simultaneously achieves homogeneous Zn2+ transport and durable mechanical stability for high Zn utilization rate (ZUR) and Coulombic efficiency (CE) of Zn electrode by adding 1,3-Dimethyl-2-imidazolidinone as a representative electrolyte additive. This bilayer SEI on Zn surface consists of a crystalline ZnCO3-rich outer layer and an amorphous ZnS-rich inner layer. The ordered outer layer improves the mechanical stability during cycling, and the amorphous inner layer homogenizes Zn2+ transport for homogeneous, dense Zn deposition. As a result, the bilayer SEI enables reversible Zn plating/stripping for 4800 cycles with an average CE of 99.95% (± 0.06%). Meanwhile, Zn | |Zn symmetric cells show durable lifetime for over 550 h with a high ZUR of 98% under an areal capacity of 28.4 mAh cm-2. Furthermore, the Zn full cells based on the bilayer SEI functionalized Zn negative electrodes coupled with different positive electrodes all exhibit stable cycling performance under high ZUR.

2.
Nano Lett ; 24(5): 1729-1737, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38289279

ABSTRACT

Rechargeable hydrogen gas batteries, driven by hydrogen evolution and oxidation reactions (HER/HOR), are emerging grid-scale energy storage technologies owing to their low cost and superb cycle life. However, compared with aqueous electrolytes, the HER/HOR activities in nonaqueous electrolytes have rarely been studied. Here, for the first time, we develop a nonaqueous proton electrolyte (NAPE) for a high-performance hydrogen gas-proton battery for all-climate energy storage applications. The advanced nonaqueous hydrogen gas-proton battery (NAHPB) assembled with a representative V2(PO4)3 cathode and H2 anode in a NAPE exhibits a high discharge capacity of 165 mAh g-1 at 1 C at room temperature. It also efficiently operates under all-climate conditions (from -30 to +70 °C) with an excellent electrochemical performance. Our findings offer a new direction for designing nonaqueous proton batteries in a wide temperature range.

3.
Technol Soc ; 70: 102020, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35755131

ABSTRACT

This research aims to explore the usage of social networking sites in the midst of the COVID-19 pandemic. To achieve the objective, this study develops and validates a scale to measure the usage of social networking sites. Data was collected via a google form link through social networking sites in India viz. Facebook, Instagram, Twitter, Telegram and WhatsApp. A total of 204 responses were found accurate and useable for the study. The population of the study includes people residing in India. Data was analyzed applying SPSS 20 and AMOS 22.0. To design and validate the scale, both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were used in conjunction with each other. The EFA results indicate a six-factor structure, explaining 73.43% of the cumulative variance, with all the items loading above 0.70. Thus, all the 20 items of six constructs meet this threshold limit. Therefore, this 20-items questionnaire emerges as an effective tool for assessing social networking usage. This study developed and validated the scale of usage of social networking sites to measure the six constructs informativeness, education, entertainment, shopping, socialization and social cause. Social media developers and analysts can use this scale from a technological standpoint to redesign and refine their websites for a better user interface. Since the research is primarily focused on India, extrapolating the results to other countries is difficult.

4.
Article in English | WPRIM (Western Pacific) | ID: wpr-979232

ABSTRACT

Aims@#Thermophilic proteases are important industrial enzymes because they can be used at high temperatures in various bioprocessing schemes. The bacterial population of the Cholistan desert was explored for thermophilic proteases and their industrial applications.@*Methodology and results@#Three bacterial isolates K1, K5 and K7 were found promising protease producers. These isolates were preliminary identified as Bacillus based on morphological characteristics and biochemical tests (positive for catalase, oxidase and citrate tests, and negative for indole and urease tests). The isolates K1, K5 and K7 were further identified as Priestia endophytica, Lysinibacillus cresolivorans and Bacillus subtilis, respectively by phylogenetic analysis. The isolates grew best at 50 °C and P. endophytica (K1), L. cresolivorans (K5) and B. subtilis (K7) produced larger zones of hydrolysis at 37 °C, 45 °C and 50 °C at pH 7, respectively. The optimum temperature where protease activity was maximum was 65 °C for P. endophytica and L. cresolivorans and 55 °C for B. subtilis, and the optimum pH was 9.@*Conclusion, significance and impact of study@#The proteases produced by these isolates were found active at high temperatures (45 °C to 85 °C) and high pH (9-12), which make them industrially important thermoalkaliphilic proteases. These proteases successfully de-haired cow’s skin and de-stained blood from cotton cloth pieces, which are rarely tested applications of these proteases.


Subject(s)
Desert , Peptide Hydrolases
5.
Chemistry ; 27(71): 17818-17823, 2021 Dec 20.
Article in English | MEDLINE | ID: mdl-34533232

ABSTRACT

Coordination polymers are promising cathode materials for rechargeable alkaline batteries. Therefore, the precise modulation of these cathodes by chemical structure and in-depth structure transform study is necessary. Here, two model coordination polymer battery cathodes were designed to demonstrate the dynamic structure-performance relationship. We studied the electrochemical performance of two kinds of nickel-based coordination polymer, comprising a planar 2D cyanide-bridged network and a 3D cyanide-bridged network pillared by pyrazine molecules. The 2D coordination polymer showed serious voltage degradation with poor rate capability, whereas the 3D coordination polymer exhibited stable voltage output coupled with high rate at various current densities. The investigation revealed the underlining relationship of plateau voltage degradation and hydrolysis process of electrodes. It was revealed that the pyrazine pillar molecules in the 3D coordination polymer could suppress the hydrolysis and lead to the in situ formation of partially hydrolyzed structure with excellent electrochemical kinetics; this exhibited obvious smaller peak separation (27 mV compared with 149 mV) and hence an almost twofold increase in capacity retention (31.9 to 50.0 %) and energy density retention (18.2 to 35.9 %) at 10 A g-1 .

6.
Article in English | WPRIM (Western Pacific) | ID: wpr-825858

ABSTRACT

Objective:To gather the fragmented literature on ethnobotany, phytochemistry and in-vitro activities of medicinal plants of Pakistan being used against common infections caused by Staphylococcus aureus (S. aureus).Methods:A large number of published and unpublished research studies related to the ethnomedicinal, phytochemical and anti-S. aureus activity of medicinal flora of Pakistan published from 1990-2018 were reviewed using online bibliographic databases such as PubMed, Web of Science, Science Direct, ResearchGate and libraries.Results:S. aureus can cause many human ailments including endocarditis, staphylococcal scalded skin syndrome, septic arthritis, respiratory problems with an estimated infection rate of 25%-35% across the globe. This review comprised of 86 medicinal plants. Data showed that people mostly used leaves (50%) for the preparation of traditional medicines. Correlation analysis on the reviewed data revealed that methanolic extract concentrations of medicinal plants was highly significantly positive correlated (r=0.8; P<0.01) with the S. aureus zone of inhibitions. S. aureus reportedly showed complete resistant to the commonly used antibiotic erythromycin. Isolated compounds like altheahexacosanyl lactone, cinnamaldehyde, niloticane, gobicusin A, asparacosin A, muzanzagenin, isoagatharesinol, friedelin, inophynone and eugenol were active against S. aureus. This study provided in-vitro proof for the flora of Pakistan used against different infections caused by S. aureus.Conclusions:Antibacterial agents from natural sources could be more effective against bacterial pathogens and will be helpful in minimizing the adverse effects of synthetic drugs, and hence provides a base for the pharmaceutical industries.

7.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-972446

ABSTRACT

Objective: To gather the fragmented literature on ethnobotany, phytochemistry and in-vitro activities of medicinal plants of Pakistan being used against common infections caused by Staphylococcus aureus (S. aureus). Methods: A large number of published and unpublished research studies related to the ethnomedicinal, phytochemical and anti-S. aureus activity of medicinal flora of Pakistan published from 1990-2018 were reviewed using online bibliographic databases such as PubMed, Web of Science, Science Direct, ResearchGate and libraries. Results: S. aureus can cause many human ailments including endocarditis, staphylococcal scalded skin syndrome, septic arthritis, respiratory problems with an estimated infection rate of 25%-35% across the globe. This review comprised of 86 medicinal plants. Data showed that people mostly used leaves (50%) for the preparation of traditional medicines. Correlation analysis on the reviewed data revealed that methanolic extract concentrations of medicinal plants was highly significantly positive correlated (r=0.8; P<0.01) with the S. aureus zone of inhibitions. S. aureus reportedly showed complete resistant to the commonly used antibiotic erythromycin. Isolated compounds like altheahexacosanyl lactone, cinnamaldehyde, niloticane, gobicusin A, asparacosin A, muzanzagenin, isoagatharesinol, friedelin, inophynone and eugenol were active against S. aureus. This study provided in-vitro proof for the flora of Pakistan used against different infections caused by S. aureus. Conclusions: Antibacterial agents from natural sources could be more effective against bacterial pathogens and will be helpful in minimizing the adverse effects of synthetic drugs, and hence provides a base for the pharmaceutical industries. http://www.apjtm.org/article.asp?issn=1995-7645;year=2018;volume=11;issue=6;spage=355;epage=368;aulast=Adnan;type=2.

8.
Journal of Breast Cancer ; : 133-141, 2016.
Article in English | WPRIM (Western Pacific) | ID: wpr-166641

ABSTRACT

PURPOSE: The promoter methylation status of cell cycle regulatory genes plays a crucial role in the regulation of the eukaryotic cell cycle. CpG cytosines are actively subjected to methylation during tumorigenesis, resulting in gain/loss of function. E2F5 gene has growth repressive activities; various studies suggest its involvement in tumorigenesis. This study aims to investigate the epigenetic regulation of E2F5 in breast cancer to better understand tumor biology. METHODS: The promoter methylation status of 50 breast tumor tissues and adjacent normal control tissues was analyzed. mRNA expression was determined using SYBR® green quantitative polymerase chain reaction (PCR), and methylation-specific PCR was performed for bisulfite-modified genomic DNA using E2F5-specific primers to assess promoter methylation. Data was statistically analyzed. RESULTS: Significant (p<0.001) upregulation was observed in E2F5 expression among tumor tissues, relative to the control group. These samples were hypo-methylated at the E2F5 promoter region in the tumor tissues, compared to the control. Change in the methylation status (Δmeth) was significantly lower (p=0.022) in the tumor samples, indicating possible involvement in tumorigenesis. Patients at the postmenopausal stage showed higher methylation (75%) than those at the premenopausal stage (23.1%). Interestingly, methylation levels gradually increased from the early to the advanced stages of the disease (p<0.001), which suggests a putative role of E2F5 methylation in disease progression that can significantly modulate tumor biology at more advanced stage and at postmenopausal age (Pearson's r=0.99 and 0.86, respectively). Among tissues with different histological status, methylation frequency was higher in invasive lobular carcinoma (80.0%), followed by invasive ductal carcinoma (46.7%) and ductal carcinoma in situ (20.0%). CONCLUSION: Methylation is an important epigenetic factor that might be involved in the upregulation of E2F5 gene in tumor tissues, which can be used as a prognostic marker for breast cancer.


Subject(s)
Humans , Biology , Breast Neoplasms , Breast , Carcinogenesis , Carcinoma, Ductal , Carcinoma, Intraductal, Noninfiltrating , Carcinoma, Lobular , Cell Cycle , Disease Progression , DNA , E2F5 Transcription Factor , Epigenomics , Eukaryotic Cells , Genes, Regulator , Methylation , Polymerase Chain Reaction , Promoter Regions, Genetic , RNA, Messenger , Up-Regulation
SELECTION OF CITATIONS
SEARCH DETAIL