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1.
J Infect Public Health ; 15(3): 321-323, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35144047

ABSTRACT

The biggest public health catastrophe of this century-the SARS coronavirus-2, 2019 (COVID-19) pandemic has affected nearly all countries. Countries after countries were gripped by the intermittent waves of the infection. One of the most affected countries was India, wherein the second wave of the pandemic afflicted the vast swathe of the nation. The medical community was overwhelmed and stressed with the inordinate number of patients. Doctors were inundated with the task of managing all kinds of COVID-19 patients ranging from mildly symptomatic to critically ill, in addition to the non-COVID-19 patients. The life of most of the population was significantly disrupted due to the fear of infection and lockdowns in various places. Due to multiple reasons, physician access was limited for mild to moderately sick patients. During this time, online consultations were at their peak and many groups came forward to help Indian patients. These groups were supported largely by Indian doctors based overseas.


Subject(s)
COVID-19 , Communicable Disease Control , Humans , India/epidemiology , Pandemics/prevention & control , SARS-CoV-2
2.
ACS Appl Mater Interfaces ; 13(50): 60279-60287, 2021 Dec 22.
Article in English | MEDLINE | ID: mdl-34881882

ABSTRACT

Voltage losses (ΔVOC) are a crucial limitation for the performance of excitonic organic solar cells (OSCs) and can be estimated by two approaches─the radiative limit and the Marcus charge-transfer (MCT) model. In this work, we show that combining the radiative limit and MCT models for voltage loss calculations provides useful insights into the physics of emerging efficient OSCs. We studied nine different donor-acceptor systems, wherein the power conversion efficiency ranges from 4.4 to 14.1% and ΔVOC varies from 0.55 to 0.95 V. For these state-of-the-art devices, we calculated the ΔVOC using the radiative limit and the MCT model. Furthermore, we combined both models to derive new insights on the origin of radiative voltage losses (ΔVrad) in OSCs. We quantified the contribution in ΔVrad due to the bulk intramolecular (S1) disorder and interfacial intermolecular (CT) disorder by revisiting the spectral regions of interest for OSCs. Our findings are in agreement with the expected relationship of VOC with Urbach energy (EU), which suggests that the low EU is beneficial for reduced losses. However, unprecedentedly, we also identify a universal, almost linear relationship between the interfacial disorder (λ) and ΔVrad. We believe that these results can be exploited by the organic photovoltaic (OPV) community for the design of new molecules and a combination of donor-acceptors to further improve OSCs.

3.
ACS Appl Mater Interfaces ; 12(40): 45083-45091, 2020 Oct 07.
Article in English | MEDLINE | ID: mdl-32900181

ABSTRACT

In this work, a unique comprehensive and comparative analysis of photoinduced charge generation, recombination kinetics, and energy losses has been carried out to study the effect of different fullerene-based acceptors (FBAs) and nonfullerene acceptors (NFAs) on the performance of organic solar cells (OSCs). For this, different FBAs, specifically ICBA, PC60BM, and PC70BM, and NFAs, namely, ITIC, IT-4F, and IEICO-4F, were employed independently along with a particular donor polymer, PBDB-T, to fabricate bulk heterojunction OSCs and their performances have been compared. This donor molecule is known to give similar power conversion efficiency (PCE) with FBAs and NFAs and hence is ideal for comparative studies. The origin of the higher PCE of NFA-based OSCs vs FBA-based OSCs is analyzed in terms of spectral coverage, charge generation, recombination, and energy loss. It is found that the energy loss (ΔEloss) is ∼0.8 to 1 eV for FBA-based OSCs, while it is 0.5-0.7 eV for NFA-based OSCs. Interestingly, for the PBDB-T:IEICO-4F-based system, energy losses due to charge generation (ΔECT) are ∼0 eV and therefore this system has minimum ΔEloss among all of the studied devices. Providing a systematic, comprehensive, and comparative outlook, our study may further be extended to new upcoming NFA systems and beyond the donor system used in this work.

4.
Polymers (Basel) ; 12(4)2020 Apr 15.
Article in English | MEDLINE | ID: mdl-32326662

ABSTRACT

Since the ability of ionic liquid (IL) was demonstrated to act as a solvent or an electrolyte, IL-based electrolytes have been widely used as a potential candidate for renewable energy storage devices, like lithium ion batteries (LIBs) and supercapacitors (SCs). In this review, we aimed to present the state-of-the-art of IL-based electrolytes electrochemical, cycling, and physicochemical properties, which are crucial for LIBs and SCs. ILs can also be regarded as designer solvents to replace the more flammable organic carbonates and improve the green credentials and performance of energy storage devices, especially LIBs and SCs. This review affords an outline of the progress of ILs in energy-related applications and provides essential ideas on the emerging challenges and openings that may motivate the scientific communities to move towards IL-based energy devices. Finally, the challenges in design of the new type of ILs structures for energy and environmental applications are also highlighted.

5.
Nanotechnology ; 30(38): 385204, 2019 Sep 20.
Article in English | MEDLINE | ID: mdl-31048572

ABSTRACT

In bulk heterojunction organic solar cells (OSCs), nanomorphology of the photoactive layer plays a crucial role in determining photocurrent and fill factor (FF) of OSCs, and therefore it is essential to control the nanomorphology of the photoactive layer to fabricate devices with high power conversion efficiency (PCE). We demonstrate the combined effects of a ZnO nanorippled electron transport layer (ETL) and solvent additive (1,8-diiodooctane (DIO)) on the nanomorphology and performance of a model OSC in an inverted geometry. The photoactive layer in the model OSC is composed of Poly [4,8-bis (5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl] (PTB7-Th):phenyl-C71-butyric acid methyl ester (PC71BM) blend. It is observed that the use of ZnO nanoripples as an ETL and DIO as a solvent additive facilitates the formation of near ideal nanomorphology of bi-continuous interpenetrating network of donor and acceptor. This is confirmed by morphological studies using atomic force microscopy, scanning electron microscopy and transmission electron microscopy. Photo-electrochemical impedance spectroscopy measurements confirm that obtained nanomorphology of bicontinuous interpenetrating network is contributing to the improved device performance. The device with 3 vol% DIO, with underneath ZnO nanoripples exhibited improved current density (J sc), FF, open circuit voltage (V oc) and PCE of 15.57 mA cm-2, 64.50%, 0.81V and 8.20%, respectively.

6.
RSC Adv ; 8(11): 5984-5991, 2018 Feb 02.
Article in English | MEDLINE | ID: mdl-35539580

ABSTRACT

In the present study, we have compared the device performance of poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thio-phene-)-2-carb-oxylate-2-6-diyl)] (PTB7-Th):phenyl-C71-butyric acid methyl ester (PCBM) organic solar cells (OSCs) in an inverted geometry with ZnO, a bilayer of ZnO and Ba(OH)2 [ZnO/Ba(OH)2] and a nanocomposite of ZnO and Ba(OH)2 [ZnO:Ba(OH)2] as electron transport layers (ETLs). Our study reveals that the performance of the devices with the ZnO/Ba(OH)2 and ZnO:Ba(OH)2 nanocomposite as ETL supersedes that of devices with only ZnO as ETL. The plausible reasons for the improved performance of these devices are identified using morphological studies, contact angle measurements, X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS) and photo-electrochemical impedance spectroscopy (EIS) measurements. It is observed that films of ZnO/Ba(OH)2 and ZnO:Ba(OH)2 nanocomposites have a low work function and are slightly more smooth and hydrophobic than ZnO films. This might have suppressed the charge recombination and thereby improved the charge collection as has been confirmed by EIS measurements.

7.
Sci Rep ; 7(1): 11103, 2017 09 11.
Article in English | MEDLINE | ID: mdl-28894241

ABSTRACT

A new generation of boronic ionic liquid namely 1-ethyl-3-methylimidazolium difluoro(oxalate)borate (EMImDFOB) was synthesized by metathesis reaction between 1-ethyl-3-methylimiazolium bromide and lithium difluoro(oxalate)borate (LiDFOB). Ternary gel polymer electrolyte membranes were prepared using electrolyte mixture EMImDFOB/LiDFOB with poly vinylidenefluoride-co-hexafluoropropylene (PVdF-co-HFP) as a host matrix by facile solvent-casting method and plausibly demonstrated its feasibility to use in lithium ion batteries. Amongst ternary gel electrolyte membrane, DFOB-GPE3, which contained 80 wt% of EMImDFOB/LiDFOB and 20 wt% PVdF-co-HFP, showed excellent electrochemical and cycling behaviors. The highest ionic conductivity was found to be 10-3 Scm-1 at 378 K. Charge-discharge profile of Li/DFOB-GPE3/LiCoO2 coin cell displayed a maximum discharge capacity of 148.4 mAhg-1 at C/10 rate with impressive capacity retention capability and columbic efficiency at 298 K.

8.
BMJ ; 345: e4975, 2012 Jul 23.
Article in English | MEDLINE | ID: mdl-22826594
9.
Int Dent J ; 57(4): 257-60, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17849684

ABSTRACT

AIM: To determine any association between pre-term low birth weight (PTLBW) neonates and periodontal disease during the mother's pregnancy. DESIGN: A multi-centered prospective case cohort study. SETTING: Ante-natal clinics at the Colonial War Memorial and Lautoka Hospitals, Fiji from 1st January to 30th June 2004. PARTICIPANTS: 670 multiethnic pregnant women. METHODS: Participants were interviewed to identify confounding variables--medical conditions, smoking, alcohol consumption, maternal age and history of preterm birth. Oral examination was conducted and included the Community Periodontal Index of Treatment Needs (CPITN). Delivery outcome was recorded for each woman. RESULTS: The mean age of participants was 25.80 +/- 5.56 years. 1.9% (n=13) women delivered preterm babies. More than 50% of this group displayed moderate to severe periodontitis compared with 13% of women who had a normal delivery. Preterm birth was also associated with the mother having had a previous preterm birth and who was more likely to be Indo-Fijian (p < 0.01). There was no significant association with where the mother lived; however, rural women with PTLBW babies had more severe periodontal disease (p = 0.0001). CONCLUSION: There is a highly significant association between pre-term birth and moderate to severe periodontal disease (p = 0.0001).


Subject(s)
Infant, Low Birth Weight , Infant, Premature , Periodontal Diseases/complications , Pregnancy Complications , Adult , Alcohol Drinking , Cohort Studies , Ethnicity , Female , Fiji , Humans , Infant, Newborn , Maternal Age , Periodontal Index , Periodontitis/complications , Pregnancy , Pregnancy Outcome , Prospective Studies , Reproductive History , Rural Health , Smoking
10.
Bioinformatics ; 20(7): 1074-80, 2004 May 01.
Article in English | MEDLINE | ID: mdl-14764577

ABSTRACT

MOTIVATION: The recent outbreak of severe acute respiratory syndrome (SARS) caused by SARS coronavirus (SARS-CoV) has necessitated an in-depth molecular understanding of the virus to identify new drug targets. The availability of complete genome sequence of several strains of SARS virus provides the possibility of identification of protein-coding genes and defining their functions. Computational approach to identify protein-coding genes and their putative functions will help in designing experimental protocols. RESULTS: In this paper, a novel analysis of SARS genome using gene prediction method GeneDecipher developed in our laboratory has been presented. Each of the 18 newly sequenced SARS-CoV genomes has been analyzed using GeneDecipher. In addition to polyprotein 1ab(1), polyprotein 1a and the four genes coding for major structural proteins spike (S), small envelope (E), membrane (M) and nucleocapsid (N), six to eight additional proteins have been predicted depending upon the strain analyzed. Their lengths range between 61 and 274 amino acids. Our method also suggests that polyprotein 1ab, polyprotein 1a, S, M and N are proteins of viral origin and others are of prokaryotic. Putative functions of all predicted protein-coding genes have been suggested using conserved peptides present in their open reading frames. AVAILABILITY: Detailed results of GeneDecipher analysis of all the 18 strains of SARS-CoV genomes are available at http://www.igib.res.in/sarsanalysis.html


Subject(s)
Gene Expression Profiling/methods , Sequence Analysis, Protein/methods , Severe acute respiratory syndrome-related coronavirus/genetics , Software , Viral Proteins/genetics , Algorithms , Genetic Testing/methods , Reproducibility of Results , Sensitivity and Specificity , Sequence Alignment/methods , Sequence Analysis/methods , Sequence Analysis, DNA/methods
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