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1.
Proc Natl Acad Sci U S A ; 119(19): e2117292119, 2022 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-35503914

RESUMEN

Stringent containment and closure policies have been widely implemented by governments to prevent the transmission of COVID-19. Yet, such policies have significant impacts on people's emotions and mental well-being. Here, we study the effects of pandemic containment policies on public sentiment in Singapore. We computed daily sentiment values scaled from −1 to 1, using high-frequency data of ∼240,000 posts from highly followed public Facebook groups during January to November 2020. The lockdown in April saw a 0.1 unit rise in daily average sentiment, followed by a 0.2 unit increase with partially lifting of lockdown in June, and a 0.15 unit fall after further easing of restrictions in August. Regarding the impacts of specific containment measures, a 0.13 unit fall in sentiment was associated with travel restrictions, whereas a 0.18 unit rise was related to introducing a facial covering policy at the start of the pandemic. A 0.15 unit fall in sentiment was linked to restrictions on public events, post lock-down. Virus infection, wearing masks, salary, and jobs were the chief concerns found in the posts. A 2 unit increase in these concerns occurred even when some restrictions were eased in August 2020. During pandemics, monitoring public sentiment and concerns through social media supports policymakers in multiple ways. First, the method given here is a near real-time scalable solution to study policy impacts. Second, it aids in data-driven and evidence-based revision of existing policies and implementation of similar policies in the future. Third, it identifies public concerns following policy changes, addressing which can increase trust in governments and improve public sentiment.


Asunto(s)
COVID-19 , Política de Salud , Opinión Pública , Medios de Comunicación Sociales , Actitud , COVID-19/epidemiología , COVID-19/prevención & control , Emociones , Humanos , Pandemias/prevención & control , SARS-CoV-2
2.
Small ; : e2403108, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39037401

RESUMEN

Interfacial electron transport in multicomponent systems plays a crucial role in controlling electrical conductivity. Organic-inorganic heterostructures electronic devices where all the entities are covalently bonded to each other can reduce interfacial electrical resistance, thus suitable for low-power consumption electronic operations. Programmed heterostructures of covalently bonded interfaces between ITO-ethynylbenzene (EB) and EB-zinc ferrite (ZF) nanoparticles, a programmed structure showing 67 978-fold enhancement of electrical current as compared to pristine NPs-based two terminal devices are created. An electrochemical approach is adopted to prepare nearly π-conjugated EB oligomer films of thickness ≈26 nm on ITO-electrode on which ZF NPs are chemically attached. A "flip-chip" method is employed to combine two EB-ZnFe2O4 NPs-ITO to probe electrical conductivity and charge conduction mechanism. The EB-ZnFe2O4 NPs exhibit strong electronic coupling at ITO-EB and EB-NPs with an energy barrier of 0.13 eV between the ITO Fermi level and the LUMO of EB-ZF NPs for efficient charge transport. Both the DC and AC-based electrical measurements manifest a low resistance at ITO-EB and EB-ZF NPs, revealing enhanced electrical current at ± 1.5 V. The programmed heterostructure devices can meet a strategy to create well-controlled molecular layers for electronic applications toward miniaturized components that shorten charge carrier distance, and interfacial resistance.

3.
Chemphyschem ; : e202400225, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39226414

RESUMEN

We demonstrated the coexistence of memresistance, memcapacitance, and meminductance non-volatile bipolar analog resistive switching in Cu (top electrode)/CuO (active layer)/ SS (bottom electrode) memory devices with and without the presence of the light. The onset of memcapacitance and meminductance is noticed from the pinched-shaped characteristics in the first and third quadrants. The variation in the scan rate also impacts the coexistence characteristics by shifting the intercept point for low resistance (LRS) and high resistance (HRS) states in positive and negative biasing voltages.  The durability and retention are measured over a period of 150 cycles and 1500 s with and without light illumination. The Weibull slope for set/reset state with and without light are 106.80/114.23 and 70.21/102.25, respectively, suggesting that stability of the device increases with light illumination. Interestingly, the memcapacitance disappears after 600 cycle and after 60 . The double logarithmic I-V characteristics suggest the trap assisted conduction (higher slope > 2) in the higher external electric field, and Ohmic behaviour in the lower applied field region. Thus, the present study provides a way for low power electronics and photoresistors together with memresistance, memcapacitance, and meminductance, simultaneously, i.e., MEMRIC in a single device.

4.
Mol Cell Biochem ; 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39316324

RESUMEN

The increasing prevalence of screen time among modern citizens has raised concerns regarding its potential impact on neuroinflammation and overall brain health. This review examines the complex interconnections between screen time and neuroinflammatory processes, particularly in children and adolescents. We analyze existing literature that explores how excessive digital media use can lead to alterations in neurobiological pathways, potentially exacerbating inflammatory responses in the brain. Key findings suggest that prolonged exposure to screens may contribute to neuroinflammation through mechanisms such as disrupted sleep patterns, diminished cognitive engagement, and increased stress levels. Similarly, we discuss the implications of these findings for mental health and cognitive development, emphasizing the need for a balanced approach to screen time. This review highlights the necessity for further research to elucidate the causal relationships and underlying mechanisms linking screen time and neuroinflammation, thereby informing guidelines for healthy media consumption.

5.
J Chem Ecol ; 50(7-8): 373-384, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38637418

RESUMEN

Scirpophaga incertulas Walker (Lepidoptera: Crambidae, yellow stem borer, YSB) is a monophagous insect pest that causes significant yield loss in rice (Oryza staiva L.). Semiochemical based pest management is being sought as an alternate to chemical pesticides to reduce pesticide footprints. We hypothesized differential release of volatiles from host rice and two companion non-host weeds, Echinochloa colona and Echinochloa crus-galli could be responsible for oviposition and biology of YSB and these chemicals could be used for YSB management. Number of eggs laid, and number of larvae hatched were significantly higher in rice plant as compared to weeds. YSB could only form dead hearts in rice plants. YSB significantly preferred host-plant volatiles compared to the non-host plants both in choice and no-choice tests in an Y-tube olfactometer. 2-Hexenal, hexanal, 2,4-hexadienal, benzaldehyde, nonanal, methyl salicylate and decanal were found in the leaf volatolomes of both the host and non-host plants in HS-SPME-GC-MS (Headspace-Solid phase micro extraction-Gas chromatography-Mass spectrometer). Pentene-3-one, 2-pentyl furan, 2,4-heptadienal, 2-octenal, 2-octenol and menthol were present only in the non-host plants. Fourteen rice unique compounds were also detected. The built-in PCA (Principal Component Analysis) and PLS-DA (Partial least squares-discriminant analysis) analysis in the MS-DIAL tool showed that the volatiles emitted from TN1 formed a cluster distinct from Echinochloa spp. and 2-octenal was identified as a unique compound. Olfactometer bioassays using synthetic compounds showed that rice unique compounds, like xylene, hexanal served as attractants whereas non-host unique compounds, like 2-pentylfuran, 2-octenal acted as repellent. The results indicate that the rice unique compounds xylene, hexanal along with other volatile compounds could be responsible for higher preference of YSB towards rice plants. Similarly, the non-host unique compounds 2-pentylfuran, 2-octenal could possibly be responsible for lower preference and defence against YSB. These compounds could be utilised for devising traps for YSB monitoring and management.


Asunto(s)
Oryza , Compuestos Orgánicos Volátiles , Animales , Oryza/química , Oryza/metabolismo , Oryza/parasitología , Compuestos Orgánicos Volátiles/metabolismo , Compuestos Orgánicos Volátiles/química , Compuestos Orgánicos Volátiles/farmacología , Compuestos Orgánicos Volátiles/análisis , Cromatografía de Gases y Espectrometría de Masas , Mariposas Nocturnas/fisiología , Oviposición/efectos de los fármacos , Echinochloa/química , Echinochloa/efectos de los fármacos , Femenino , Larva/fisiología , Microextracción en Fase Sólida , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Malezas , Olfatometría
6.
J Plant Res ; 137(3): 463-484, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38337083

RESUMEN

Floral biochemistry and stress physiology is an underexplored aspect of mangroves, which should be investigated as part of preservation and restoration efforts. A thriving true mangrove tree (Bruguiera gymnorrhiza (L.) Lamk.) and a threatened mangrove-associate species (Heritiera fomes Buch. Ham.) were studied in the Sundarban region of India for seasonal variations in floral odours, non-volatile phytochemicals, antioxidant enzyme activities, and surface water chemistry in surrounding habitat. Both species were found to exhibit significant differences in floral volatilomes, protein contents, antioxidant enzyme activities, total flavonoids, and total phenolic contents between spring and autumn blooms. The bird-pollinated flowers of B. gymnorrhiza also showed considerable seasonal differences in floral anthocyanin and proline contents, indicating vulnerability of the post-anthesis open flowers to environmental factors. Contrarily to previous findings, B. gymnorrhiza floral bouquet appeared to be enriched in various classes of volatiles - dominated by sulphurous compounds in bud stage and terpenoids in open stage. Floral anthocyanins, contributing to the striking colouration of the calyx, were found to comprise cyanidin and delphinidin derivatives. Other glycosides of cyanidin and delphinidin were detected in H. fomes flowers, contributing to visual guides to potential food rewards for pollinating insects. Floral tissue in H. fomes was found to be protected by densely overlapping layers of stellate trichomes containing sesquiterpenoids as phytoprotectants. Comparison of the two floral species suggested that H. fomes flowering is optimized to oligohaline (but not freshwater) vernal conditions; whereas B. gymnorrhiza blooms are adapted for biologically enriched (including abundant herbivores and microbial growth), mesohaline forest habitats.


Asunto(s)
Ecosistema , Flores , Odorantes , Rhizophoraceae , Flores/fisiología , Rhizophoraceae/fisiología , Odorantes/análisis , India , Antocianinas/metabolismo , Antocianinas/análisis , Humedales , Estrés Fisiológico , Estaciones del Año , Polinización , Animales , Flavonoides/metabolismo , Flavonoides/análisis , Antioxidantes/metabolismo , Compuestos Orgánicos Volátiles/metabolismo , Compuestos Orgánicos Volátiles/análisis , Fitoquímicos/metabolismo , Fitoquímicos/química , Fenoles/metabolismo , Fenoles/análisis , Prolina/metabolismo , Prolina/análisis
7.
Ann Plast Surg ; 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39150820

RESUMEN

BACKGROUND: Hand injuries pose challenges due to complexity and aesthetic-functional concerns. Dorsum of hand injuries are difficult to treat due to thin skin cover and increased propensity to exposure of underlying structures. Perforator-based flaps can provide better outcomes with minimal donor site morbidity. This study aims to bridge the gap in anatomical knowledge and explore the potential benefits of dorsal carpal artery perforator flap. MATERIALS AND METHODS: A prospective study was done from July 2021 to June 2023, focused on study of dorsal carpal artery perforators on 12 fresh frozen cadaveric hands. Anatomical study involved injection of red latex into arteries at the wrist, followed by dissection and measurements. During the clinical phase, we used the inferences gained from the anatomical study to identify and mark perforator of dorsal carpal arteries. We performed V-Y advancement flap based on the DCPs in 5 patients who had dorsum of hand defects due to trauma. RESULTS: The study was carried out on 6 fresh frozen cadavers (12 hands). Anatomical findings revealed the anatomical location, caliber, and consistent number of dorsal carpal artery perforators supplying the dorsum of the hand arranged in 2 rows. Clinically, we applied this insight to create V-Y flaps in 5 patients with successful outcomes, thus, offering DCP-based flap as an alternative to distant flaps. CONCLUSION: DCP-based flaps offer an efficient solution for reconstructing proximal hand defects over the dorsum, with minimal complications, enhancing our understanding of hand reconstruction options. The study's comprehensive anatomical insights and clinical outcomes contribute to improving hand defect management and surgical techniques.

8.
Subst Use Misuse ; 59(1): 29-40, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37907086

RESUMEN

BACKGROUND: This systematic review evaluated the available medical literature on the prevalence and trends of waterpipe tobacco smoking among adolescents and youth in jurisdictionally representative populations. METHODS: PubMed, Embase, and Scopus were searched for relevant studies from inception until 31 December 2022 that reported the burden of waterpipe smoking among adolescents and youth (10-24 years of age). We extracted qualitative data on the demographic characteristics, burden, and correlates of waterpipe smoking (PROSPERO ID: CRD42022310982). RESULTS: A total of 2,197 articles were screened and 62 were included in the analysis. The majority (29) of the studies was from the United States of America and there were no studies from the south-east Asian region. The prevalence of ever waterpipe smoking among the 10-24 years age group was noted to be 18.16% (95% CI, 18.03-18.29). The prevalence of current (30-day) waterpipe smoking was 6.43% (95% CI, 6.34-6.50). The age of initiation of waterpipe smoking was variable. The prevalence of waterpipe smoking was higher among males, among those who belong to the high- and middle-income groups, and among university students. The common risk factors of waterpipe smoking included cigarette smoking, alcohol, and substance use. Waterpipe smoking resulted in increased susceptibility to the use of conventional forms of tobacco (e.g. smoking) among those who were never smokers. CONCLUSION: Waterpipe smoking usage was significantly high among adolescents and young adults. Developing regulatory guidelines for water-pipe smoking, surveillance of its use, intervention, and specific policy frameworks may be considered a public health priority.


Asunto(s)
Pipas de Agua , Tabaco para Pipas de Agua , Fumar en Pipa de Agua , Masculino , Adulto Joven , Humanos , Adolescente , Estados Unidos , Fumar en Pipa de Agua/epidemiología , Encuestas y Cuestionarios , Prevalencia
9.
Int J Phytoremediation ; 26(1): 45-51, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37291794

RESUMEN

The present research work approaches the accumulation of fluoride ions from contaminated water using an aquatic plant Monochoria hastate L. in hydroponic culture. A design of experiment (DOE) has been adopted and an analysis of variance has been conducted to establish the statistical significance of various process parameters. The different experimental factors are root and shoot (Factor A), fluoride concentration (Factor B), and experimental days (Factor C) largely influence the output response. Plants treated with 5 mg/L of fluoride solutions accumulated the highest concentration in root biomass 1.23 mg/gm, and shoot biomass 0.820 mg/gm, dry weight after 21 days' experimentation. The accumulation mechanism and potentiality of treated plants depend on root cells of the plasma membrane and energy-capturing molecules of adenosine triphosphate. Monochoria hastate L. root biomass was characterized to confirm the accumulation of fluoride ions in the experimented plants using scanning electron micrographs-energy dispersive spectrum (SEM-EDS), and Fourier transforms infrared analysis (FTIR) analysis.


The novelty of this study is the high fluoride accumulation efficiency in hydroponic treatment by Monochoria hastate L an excellent choice for phytoremediation technique. The Design of Experiment (DOE) has a good approach for the optimization of fluoride in the accumulation process. The maximum absorption of fluoride ions in root biomass is 1.23 mg/gm, and shoot biomass is 0.820 mg/gm, dry weight after 21 days of treatment. To know the fluoride ions in shoot and root biomass are characterized using scanning electron micrographs-energy dispersive spectrum (SEM-EDS), and Fourier transforms infrared analysis (FTIR).


Asunto(s)
Fluoruros , Agua , Fluoruros/análisis , Fluoruros/metabolismo , Agua/análisis , Hidroponía , Biodegradación Ambiental , Biomasa , Raíces de Plantas/química
10.
Nano Lett ; 23(23): 10998-11005, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38048073

RESUMEN

We describe here the fabrication of large-area molecular junctions with a configuration of ITO/[Ru(Phen)3]/Al to understand temperature- and thickness-dependent charge transport phenomena. Thanks to the electrochemical technique, thin layers of electroactive ruthenium(II)-tris(phenanthroline) [Ru(Phen)3] with thicknesses of 4-16 nm are covalently grown on sputtering-deposited patterned ITO electrodes. The bias-induced molecular junctions exhibit symmetric current-voltage (j-V) curves, demonstrating highly efficient long-range charge transport and weak attenuation with increased molecular film thickness (ß = 0.70 to 0.79 nm-1). Such a lower ß value is attributed to the accessibility of Ru(Phen)3 molecular conduction channels to Fermi levels of both the electrodes and a strong electronic coupling at ITO-molecules interfaces. The thinner junctions (d = 3.9 nm) follow charge transport via resonant tunneling, while the thicker junctions (d = 10-16 nm) follow thermally activated (activation energy, Ea ∼ 43 meV) Poole-Frenkel charge conduction, showing a clear "molecular signature" in the nanometric junctions.

11.
Prep Biochem Biotechnol ; 54(7): 882-895, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38170207

RESUMEN

In growing plant population, effect of stress is a perturb issue affecting its physiological, biochemical, yield loss and developmental growth. Protein-L-isoaspartate-O-methyltransferase (PIMT) is a broadly distributed protein repair enzyme which actuate under stressful environment or aging. Stress can mediate damage converting protein bound aspartate (Asp) residues to isoaspartate (iso-Asp). This spontaneous and deleterious conversion occurs at an elevated state of stress and aging. Iso-Asp formation is associated with protein inactivation and compromised cellular survival. PIMT can convert iso-Asp back to Asp, thus repairing and contributing to cellular survival. The present work describes the isolation, cloning, sequencing and expression of PIMT genes of Carica papaya (Cp pimt) and Ricinus communis (Rc pimt) Using gene specific primers, both the pimts were amplified from their respective cDNAs and subsequently cloned in prokaryotic expression vector pProEXHTa. BL21(DE3) strain of E. coli cells were used as expression host. The expression kinetics of both the PIMTs were studied with various concentrations of IPTG and at different time points. Finally, the PIMT supplemented BL21(DE3) cells were evaluated against different stresses in comparison to their counterparts with the empty vector control.


Asunto(s)
Carica , Proteínas de Plantas , Proteína D-Aspartato-L-Isoaspartato Metiltransferasa , Ricinus , Carica/genética , Carica/enzimología , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteína D-Aspartato-L-Isoaspartato Metiltransferasa/genética , Proteína D-Aspartato-L-Isoaspartato Metiltransferasa/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ricinus/enzimología , Ricinus/genética , Estrés Fisiológico
12.
Indian J Plast Surg ; 57(3): 179-183, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39139678

RESUMEN

Background Early detection of free flap compromise is critical for salvage of the flap. Various methods of free flap monitoring have been described, but clinical assessment is the standard method for among all. In this study, role of infrared thermography is evaluated for free flap monitoring. Materials and Methods In patients undergoing free flap surgery, monitoring was done using standard clinical parameters and infrared thermography as per our institutional protocol. Mean temperature difference (∆T) between the flap and the surrounding skin was calculated using the temperature readings from the thermal images intra- and postoperatively. The accuracy of infrared thermography in flap monitoring was assessed in comparison to the standard clinical protocol. Results Forty-one flaps were included in the analysis, out of which five flaps got compromised. It was observed that the mean temperature difference was higher (mean ∆T 0.20-0.59 vs. 2.38-3.32) when there was a flap compromise, and this temperature difference was evident even before the development of clinical signs. The temperature difference in venous thrombosis (mean ∆T 1.0-2.7) was found to be slightly lower than in arterial insufficiency (mean ∆T 2.1-4.4). For a ∆T cutoff value of 2°C, the thermal camera had a sensitivity of 88.6%, specificity of 98.9%, positive predictive value of 93.9%, and negative predictive value of 97.7%. Conclusion Infrared thermography is a valuable and noninvasive objective tool in free flap monitoring, which can detect flap compromise (increasing value of ∆T) even before it becomes clinically evident.

13.
Angew Chem Int Ed Engl ; 63(15): e202317413, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38252076

RESUMEN

Metal-organic frameworks (MOFs) are a specific class of hybrid, crystalline, nano-porous materials made of metal-ion-based 'nodes' and organic linkers. Most of the studies on MOFs largely focused on porosity, chemical and structural diversity, gas sorption, sensing, drug delivery, catalysis, and separation applications. In contrast, much less reports paid attention to understanding and tuning the electrical properties of MOFs. Poor electrical conductivity of MOFs (~10-7-10-10 S cm-1), reported in earlier studies, impeded their applications in electronics, optoelectronics, and renewable energy storage. To overcome this drawback, the MOF community has adopted several intriguing strategies for electronic applications. The present review focuses on creatively designed bulk MOFs and surface-anchored MOFs (SURMOFs) with different metal nodes (from transition metals to lanthanides), ligand functionalities, and doping entities, allowing tuning and enhancement of electrical conductivity. Diverse platforms for MOFs-based electronic device fabrications, conductivity measurements, and underlying charge transport mechanisms are also addressed. Overall, the review highlights the pros and cons of MOFs-based electronics (MOFtronics), followed by an analysis of the future directions of research, including optimization of the MOF compositions, heterostructures, electrical contacts, device stacking, and further relevant options which can be of interest for MOF researchers and result in improved devices performance.

14.
Angew Chem Int Ed Engl ; : e202413846, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39192732

RESUMEN

The homologous series of gaseous C1-4 alkanes represents one of the most abundant sources of short alkyl fragments. However, their application in synthetic organic chemistry is exceedingly rare due to the challenging C-H bond cleavage, which typically demands high temperatures and pressures, thereby limiting their utility in the construction of complex organic molecules. In particular, the formation of C(sp2)-C(sp3) bonds is crucial for constructing biologically active molecules, including pharmaceuticals and agrochemicals. In this study, we present the previously elusive coupling between gaseous alkanes and (hetero)aryl bromides, achieved through a combination of Hydrogen Atom Transfer (HAT) photocatalysis and nickel-catalyzed cross coupling at room temperature. Utilizing flow technology allowed us to conduct this novel coupling reaction with reduced reaction times and in a scalable fashion, rendering it practical for widespread adoption in both academia and industry. Density Functional Theory (DFT) calculations unveiled that the oxidative addition constitutes the rate-determining step, with the activation energy barrier increasing with smaller alkyl radicals. Furthermore, radical isomerization observed in propane and butane analogues could be attributed to the electronic properties of the bromoarene coupling partner, highlighting the crucial role of oxidative addition in the observed selectivity of this transformation.

15.
J Food Sci Technol ; 61(1): 62-68, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38192716

RESUMEN

This paper presents the results of two proficiency testing (PT) rounds conducted by the Export Inspection Agency (EIA) Chennai laboratory in 2021 for food testing laboratories in India. The PT program was designed in accordance with ISO/TS 22117, a standard for proficiency testing in food microbiology, and targeted Listeria monocytogenes and Salmonella spp as the organisms of focus. The samples were found to be stable and recoverable during the analysis, and all PT sample packages were delivered to participant laboratories in good condition. The participant laboratories reported high sensitivity rates of 100% for PT round 061021 M and 96.49% for PT round 050721 M. The accuracy rate in PT round 061021 M was 91.89% and 92.10% in case of PT round 050721 M. However, there were some false positive and false negative results reported by some participant laboratories in both PT rounds, which may have been caused by operational errors or inconsistencies in analysis. During the PT round 061021 M, out of a total of 38 participant laboratories, five laboratories reported false positive results and one laboratory reported a false negative result. Similarly, during the PT round 050721 M, six laboratories reported false positive results which resulted in their results being deemed unsatisfactory.

16.
Chemphyschem ; 24(21): e202300142, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37646108

RESUMEN

Cu2 ZnSnS4 (CZTS) active material-based resistive random-access memory (RRAM) devices are investigated to understand the impact of three different Cu, Ag, and Al top electrodes. The dual resistance switching (RS) behaviour of spin coated CZTS on ITO/Glass is investigated up to 102 cycles. The stability of all the devices (Cu/CZTS/ITO, Ag/CZTS/ITO, and Al/CZTS/ITO) is investigated up to 103  sec in low- (LRS) and high- (HRS) resistance states at 0.2 V read voltage. The endurance up to 102 cycles with 30 msec switching width shows stable write and erase current. Weibull cumulative distribution plots suggest that Ag top electrode is relatively more stable for set and reset state with 33.61 and 25.02 shape factors, respectively. The charge carrier transportation is explained by double logarithmic plots, Schottky emission plots, and band diagrams, substantiating that at lower applied electric field intrinsic copper ions dominate in Cu/CZTS/ITO, whereas, at higher electric filed, top electrodes (Cu and Ag) dominate over intrinsic copper ions. Intrinsic Cu+ in CZTS plays a decisive role in resistive switching with Al electrode. Further, the impedance spectroscopy measurements suggest that Cu+ and Ag+ diffusion is the main source for the resistive switching with Cu and Ag electrodes.

17.
Phys Chem Chem Phys ; 25(29): 19868-19881, 2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37455647

RESUMEN

We demonstrated the resistive random access memory characteristics for Cu (top contact)/BFO/PMMA (active layer)/ITO (bottom electrode)/PET sheet as a flexible substrate device configuration. The device showed non-volatile bipolar resistive switching characteristics with good repeatability and the coexistence of NDR for 100 cycles or more with 0.28/3.43 mW power consumption for 1st/100th cycles. The device retains its read state for 104 s or more and switches from LRS to HRS or vice versa for 103 cycles with a pulse width of 100 ms for a write-read-erase-read pulse without affecting the memory characteristics. The Weibull distribution suggests that a set state is more stable than the reset state with shape factor ß = 25.20. The device follows Ohmic behavior for the lower applied external field and Child square and Schottky emission for the higher external fields. The Joule heating, Sorets, and Fick's forces are responsible for the formation and rupturing of ionic filament. The coexistence of resistive switching and flexible strength of the device sustains the bending curvature of infinity, 0.2 cm, 1 cm, 1.7 cm, and 2.2 cm. The memory characteristics are retained under tensile conditions for 100 cycles or more. More interestingly, the power consumption for sustaining the NDR region with bending (19 µW) is much lower than without bending (0.19 mW). Thus, this study provides the possibility of integrating BFO with flexible substrates suitable for hybrid organic/inorganic memory structures.

18.
Environ Res ; 216(Pt 1): 114334, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36162475

RESUMEN

Temperature can be considered as pro-oxidant factor that favor the generation of ROS on the species with lower antioxidant efficiency may leads to affect the level of tolerance. So the basic antioxidant enzyme activity (LPO, CAT, SOD, GPx and GST) of gastropod Nerita oryzarum was evaluated at six stations which located between the thermal effluent discharges points from Tarapur Atomic Power Station, India. The antioxidant enzyme activity was shown that all enzyme at discharge point (SII station) where the maximum temperature of heated effluent released. The average maximum values of enzyme activity recorded for LPO, CAT, SOD, GPx and GST were 1.88 ± 0.12, 1.52 ± 0.14, 22.57 ± 0.89, 1.98 ± 0.2 and 17.22 ± 0.63 respectively. The results were inferred the level water temperature directly proportional to the oxidative stress by ROS generation in Nerita oryzarum. Similar results were observed at laboratory experiment under the condition i.e., Treatment 1 (300C), Treatment 2 (350C), Treatment 3 (400C) and Control (250C). The present prima facie work clearly indicated the physiological response of N. oryzarum with respect to antioxidant enzyme activity against the heated effluent released, which will be useful as baseline information for future research work.


Asunto(s)
Antioxidantes , Gastrópodos , Animales , Antioxidantes/metabolismo , Gastrópodos/metabolismo , Temperatura , Especies Reactivas de Oxígeno , Estrés Oxidativo/fisiología , Superóxido Dismutasa/metabolismo , Centrales Eléctricas , Catalasa/metabolismo
19.
Biotechnol Appl Biochem ; 70(5): 1741-1753, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37183365

RESUMEN

Alkaline proteases from microbial sources have been found suitable for diverse industrial applications, with serine proteases being the most common enzymes used in the detergent industry. In the present study, we have purified and characterized an extracellular alkaline serine protease from Microbacterium paraoxydans sp. SKS10. The protease was purified using ammonium sulfate precipitation followed by different chromatography techniques (fold purification 6.919). Km and Vmax for the protease were determined to be 0.183 mg/mL and 4.904 U/mL, respectively. This enzyme is a thermostable high molecular weight (∼109.4 kDa) protease which has maximal activity at 60°C, and above pH 10. Inhibitor assays revealed the enzyme to be a serine protease whose activity increased by 2.5-fold in the presence of EDTA. This enzyme remained active in the presence of various metal salts and organic solvents and was compatible with commercially available laundry detergents highlighting its potential for use in the detergent industry.


Asunto(s)
Detergentes , Serina Proteasas , Serina Proteasas/química , Detergentes/química , Peso Molecular , Endopeptidasas/química , Endopeptidasas/metabolismo , Proteínas Bacterianas/química , Concentración de Iones de Hidrógeno , Estabilidad de Enzimas , Temperatura
20.
Xenobiotica ; 53(3): 163-172, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37216617

RESUMEN

Delayed-release dimethyl fumarate (DMF), Tecfidera®, is approved globally for treating relapsing-remitting multiple sclerosis. The disposition of DMF was determined in humans after administration of a single oral dose of [14C]DMF, and the total recovery was estimated to be between 58.4% to 75.0%, primarily through expired air.The absorption of [14C]DMF-derived radioactivity was rapid, with Tmax at 1h postdose. Glucose was the predominant circulating metabolite, accounting for ∼60% of the total extractable radioactivity. Cysteine and N-acetylcysteine conjugates of mono- or di-methyl succinate were found to be the major urinary metabolites.In vitro studies showed that [14C]DMF was mainly metabolised to MMF, and fumarase exclusively converted fumaric acid to malic acid and did not catalyse the conversion of fumaric acid esters to malic acid. DMF was observed to bind with human serum albumin through Michael addition to the Cys-34 residue when exposed to human plasma.These findings indicate that DMF undergoes metabolism via hydrolysis, GSH conjugation, and the TCA cycle, leading to the formation of citric acid, CO2, and water. These ubiquitous and well-conserved metabolism pathways minimise the risk of drug-drug interactions and reduce variability related to pharmacogenetics and ethnicity.


Asunto(s)
Dimetilfumarato , Xenobióticos , Humanos , Dimetilfumarato/uso terapéutico , Biotransformación , Acetilcisteína , Redes y Vías Metabólicas , Inmunosupresores/uso terapéutico
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