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1.
J Colloid Interface Sci ; 668: 25-36, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38669993

RESUMO

In the realm of polymer composites, there is growing interest in the use of more than one filler for achieving multifunctional properties. In this work, a composite separator membrane has been developed for lithium-ion battery application, by incorporating conductive silver nanowires (AgNWs) and titanium dioxide (TiO2) nanoparticles into a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer matrix. The composite membranes were manufactured by solvent casting and thermally induced phase separation, with total filler content varying up to 10 wt%. The ternary composites composites present improved mechanical characteristics, ionic conductivity and lithium transfer number compared to the neat polymer matrix. On the other hand, the filler type and content within the composite has little bearing on the morphology, polymer phase, or thermal stability. Once applied as a separator in lithium-ion batteries, the highest discharge capacity value was obtained for the 5 wt% AgNWs/5 wt% TiO2/PVDF-HFP membrane at different C-rates, benefiting from the synergetic effect from both fillers. This work demonstrates that higher battery performance can be achieved for next-generation lithium-ion batteries by using separator membranes based on ternary composites.

2.
Opt Quantum Electron ; 54(4): 222, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35308634

RESUMO

Nano-particle embedded system plays an importance in developing of future terahertz (THz) radiation source for real-world applications. The laser interactions with nanoparticle embedded system can produce a wide range of THz radiation due to plasma oscillations excitation. We investigate THz field generation from the laser-beat wave interaction with a mixture of spherical and cylindrical graphite nanoparticles in argon gas. Different laser intensity distributions such as Gaussian, cosh-Gaussian, flat-top and ring shape laser pulses have been studied in this work. The relevant plasmon resonance conditions with appropriate symmetry of spherical nanoparticles and cylindrical nanoparticles are discussed. THz field is enhanced upto the order of 10 2 when the laser intensity redistributes along the polarization direction for a ring shape field envelope.

3.
Ann Oncol ; 33(3): 299-309, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34861374

RESUMO

BACKGROUND: In the BROCADE3 trial, addition of the poly(ADP-ribose) polymerase inhibitor, veliparib, to carboplatin/paclitaxel improved progression-free survival (PFS) (hazard ratio 0.71, 95% confidence interval 0.57-0.88; P = 0.002) in patients with advanced human epidermal growth factor receptor 2-negative, germline BRCA1/2-mutated breast cancer. A subset of patients discontinued both carboplatin and paclitaxel before progression and continued on veliparib/placebo maintenance monotherapy until progression. Analyses in this patient subgroup are reported. PATIENTS AND METHODS: Patients were randomized 2 : 1 to veliparib plus carboplatin/paclitaxel or placebo plus carboplatin/paclitaxel. Veliparib (120 mg twice daily) or placebo was given on days -2 to 5, carboplatin (area under the curve 6 mg/ml) on day 1, and paclitaxel (80 mg/m2) on days 1, 8, and 15 of 21-day cycles. Patients who discontinued both carboplatin and paclitaxel before progression received blinded study drug monotherapy at an increased dose of 300-400 mg twice daily continuously. PFS was the primary endpoint. Exploratory analyses were carried out in the subgroup of patients who received blinded study drug as monotherapy. A time-varying Cox model including data from all patients was also used to evaluate treatment effect in the combination and monotherapy phases. RESULTS: A total of 136 of 337 patients randomized to veliparib plus carboplatin/paclitaxel and 58/172 patients randomized to placebo plus carboplatin/paclitaxel discontinued both carboplatin and paclitaxel before progression and continued on blinded veliparib or placebo monotherapy. In this blinded monotherapy subgroup, investigator-assessed median PFS from randomization was 25.7 months with veliparib versus 14.6 months with placebo. Hazard ratios from a time-varying Cox model favored veliparib during both combination therapy and monotherapy. Any-grade adverse events occurring in the monotherapy phase were primarily gastrointestinal. The most common grade ≥3 adverse events were neutropenia and anemia (4% each with veliparib; 5% and 2%, respectively, with placebo). CONCLUSIONS: Veliparib maintenance monotherapy had a tolerable safety profile and may extend PFS following combination chemotherapy.


Assuntos
Neoplasias da Mama , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Benzimidazóis , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Carboplatina , Feminino , Células Germinativas , Humanos , Paclitaxel
4.
Radiat Prot Dosimetry ; 193(3-4): 247-258, 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-33942069

RESUMO

A method has been proposed to evaluate the kinetic parameters, viz. activation energy ($E$) and order of kinetics ($b$) from a single or isolated thermoluminescence (TL) glow peak. Along with the area under the entire curve, this method uses a set of three arbitrary data points and calculates the partial area under the curve from each point to the endpoint. In this way, the entire information associated with the curve is used and the method is named as 'Three-Point Area' (TPA) method. We have applied it successfully on a number of theoretically simulated TL curves generated in One Trap One Recombination centre (OTOR) model and General-Order Kinetics (GOK) model under quasi-equilibrium approximations with linear heating scheme. The activation energies are found in good agreement with input values for both the models. For OTOR model, temperature average of order of kinetics is estimated to compare with the present result. Systematic analysis is carried out for estimation of errors inherent in the method in the purview of GOK model. A closer look on the results reveals that any set of three points, preferably chosen from the rising side of the curve, can yield activation energy and order of kinetics. The validity of the method to extract $E$ and $b$ from experimental glow curves is exemplified by considering experimental TL data reported in literature. Finally, a complete study starting from the synthesis of a new phosphor $\mathrm{K_2SrP_2O_7:Pr} $ and analysis of the recorded TL data to estimate $E$ and $b$ employing the TPA method has been reported.


Assuntos
Dosimetria Termoluminescente , Cinética , Temperatura
5.
Mitochondrion ; 49: 135-148, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31382041

RESUMO

This communication reports a comprehensive profile of mitogenome analysis of Rhipicephalus microplus, isolated and identified from Andaman and Nicobar islands, a part of Maritime South East Asia. Complete mitogenome of Indian isolate of R. microplus (MK234703) was 14,903 bp. Mitochondrial (mt.) genome had 13 protein coding genes (PCGs), 22 tRNAs, two ribosomal subunits and two control regions. All PCGs were located on the H-strand except nad1, nad5, nad4 and nad4L. All start codons were ATN codon and abbreviated stop codons were seen in cox-2-3, nad-5 and cytb. A purine rich tick-box motif has been identified. A tandem repeat unit (TTTATT), described as a region alike to nad1 was identified in 130 bp insertion in between nad1 and tRNA-Glu and in nad1 sequence. Presence of two control regions (CRs) proved that, two CRs have evolved in concert rather than independently. Strong biasness towards A and T in Indian isolate of R. microplus is a typical feature for most of the arthropods. Subtracted values of dn and ds suggested that, there was least effect of nt. sequence of cox1 gene when Indian isolate was compared with other isolates of Rhipicephalus. On the basis of phylogenetic analysis, species of the genus Rhipicephalus could be clustered in three groups; ticks of the genera belonging to sub-family Rhipicephalinae could be grouped in a single cluster. Finally, cox1 sequence of MK234703 indicated that the isolate belonged to clade A sensu Burger et al., 2014 which has not been reported earlier from India.


Assuntos
Genoma Mitocondrial , Mitocôndrias/genética , Filogenia , Rhipicephalus/genética , Animais , Índia , Proteínas Mitocondriais/genética , RNA Ribossômico/genética , RNA de Transferência/genética
6.
Mitochondrial DNA B Resour ; 4(2): 2808-2810, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-33365738

RESUMO

Nicobari pig and Andaman Desi pig are indigenous pig germplasm of Andaman and Nicobar islands, India. Over the last two decades, the pig breeds witnessed a rapid decline in population, necessitating immediate characterization and conservation. The present study depicts the complete mitochondrial genome sequence of Nicobari pig and Andaman Desi pig. The mitogenomes of both the breeds encode 37 genes including 13 protein coding genes, 22 tRNAs, and two ribosomal RNA genes. In addition, a control region (D-loop) was also present. Phylogenetic analysis showed that Nicobari is phylogenetically close to Banna mini and Breed I pig, whereas Andaman Desi pig is close to Mong cai and Jinhua pig breeds. The results of the study will be helpful for formulating of conservation strategy of the native swine breeds.

7.
J Environ Manage ; 197: 89-95, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28334647

RESUMO

Rice the staple food is a notable intake source of arsenic to the rural population of eastern India through food-chain. A field survey was carried out to study the variation of arsenic load in different parts of rice genotype Shatabdi (most popular genotype of the region) exposed to varying level of arsenic present in the irrigation water and soil. As irrigation is the primary source of arsenic contamination, a study was conducted to assess arsenic load in rice ecosystem under deficit irrigation practices like intermittent ponding (IP), saturation (SAT) and aerobic (AER) imposed during stress allowable stage (16-40 days after transplanting) of the crop (genotype Shatabdi). Present survey showed that arsenic content in water and soil influenced the arsenic load of rice grain. Variation in arsenic among different water and soil samples influenced grain arsenic load to the maximum extent followed by straw. Deviation in root arsenic load due to variation in water and soil arsenic content was lowest. Arsenic concentration of grain is strongly related to the arsenic content of both irrigation water and soil. However, water has 10% higher impact on grain arsenic load over soil. Translocation of arsenic from root to shoot decreased with the increase in arsenic content of water. Imposition of saturated and aerobic environment reduced both yield and grain arsenic load. In contrast under IP a marked decrease in grain arsenic content recorded with insignificant reduction in yield. Deficit irrigation resulted in significant reduction (17.6-25%) in arsenic content of polished rice and the values were lower than that of the toxic level (<0.2 mg kg-1). In contrast the decrease in yield was to the tune of 0.9% under IP regime over CP.


Assuntos
Arsênio , Poluentes do Solo , Irrigação Agrícola , Humanos , Índia , Oryza , Solo
8.
Cell Death Differ ; 23(2): 216-30, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26138443

RESUMO

Reactive oxygen species (ROS) may cause cellular damage and oxidative stress-induced cell death. Autophagy, an evolutionarily conserved intracellular catabolic process, is executed by autophagy (ATG) proteins, including the autophagy initiation kinase Unc-51-like kinase (ULK1)/ATG1. Although autophagy has been implicated to have both cytoprotective and cytotoxic roles in the response to ROS, the role of individual ATG proteins, including ULK1, remains poorly characterized. In this study, we demonstrate that ULK1 sensitizes cells to necrotic cell death induced by hydrogen peroxide (H2O2). Moreover, we demonstrate that ULK1 localizes to the nucleus and regulates the activity of the DNA damage repair protein poly (ADP-ribose) polymerase 1 (PARP1) in a kinase-dependent manner. By enhancing PARP1 activity, ULK1 contributes to ATP depletion and death of H2O2-treated cells. Our study provides the first evidence of an autophagy-independent prodeath role for nuclear ULK1 in response to ROS-induced damage. On the basis of our data, we propose that the subcellular distribution of ULK1 has an important role in deciding whether a cell lives or dies on exposure to adverse environmental or intracellular conditions.


Assuntos
Estresse Oxidativo , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Transporte Ativo do Núcleo Celular , Animais , Apoptose , Autofagia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia , Núcleo Celular/metabolismo , Ativação Enzimática , Células HEK293 , Humanos , Peróxido de Hidrogênio/farmacologia , Camundongos , Poli(ADP-Ribose) Polimerase-1
9.
Neotrop Entomol ; 44(4): 374-84, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26174962

RESUMO

In tropical freshwaters, different species of water bugs (Heteroptera) constitute a guild sharing similar prey resources including chironomid and mosquito larvae. Assuming possibilities of intraguild predation (IGP) among the constituent members, an attempt was made to evaluate the effects of prey and predator density on the mortality of mosquito and chironomid larvae (shared prey), using Laccotrephes griseus Guérin-Méneville (Hemiptera: Nepidae) and Ranatra filiformis Fabricius (Hemiptera: Nepidae) as IG predators and Anisops bouvieri Kirkaldy (Hemiptera: Notonectidae) as IG prey. The predation on mosquito and chironomid larvae varied with the density and combinations of the predators. When present as conspecific IG predators, L. griseus exhibited greater effect on the prey mortality than R. filiformis. The effects on shared prey suggest that the two predators are not substitutable in terms of the effect on the shared prey mortality. The mortality of A. bouvieri (IG prey) at low shared prey density was significantly different (p < 0.05) from high shared prey density. In view of predatory effect of the heteropteran predators on the dipteran larvae, the results suggest possible interference by the presence of A. bouvieri as an intermediate predator. It seems that the presence of heteropteran predators including A. bouvieri as IG prey may benefit the dipteran prey under situations when the density is low in tropical waters. The intensity of the predatory effect may differ based on the species composition at IG predator level. For mosquito biological control, the interactions between the predators may not be substitutable and are independent in their effects.


Assuntos
Heterópteros/fisiologia , Comportamento Predatório , Animais , Culicidae , Larva , Densidade Demográfica
10.
Opt Express ; 23(14): 17909-22, 2015 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-26191851

RESUMO

Recently, it has been greatly appreciated that intense light matter interaction is modified due to the nano- and microstructures in the target by--surface plasmons, laser energy localization scattering etc. Extreme laser intensities produce dense plasmas and collective mechanisms generate energetic electrons, ions and hard x-rays. Recently, it is postulated that the anharmonic electron motion, driven by ultrashort, high-intensity laser pulses, provides a universal mechanism for the laser absorption. Here, we provide the first demonstration of anharmonic-resonance-aided high laser-absorption in a biological system. At intensities of ∼ 10¹6⁻¹8 W/cm², 40 fs pulses excite a plasma formed with E. coli bacteria. The density-inhomogeneities due to the micro- and nanostructures in the bacterial target increase anharmonic resonance (AHR) heating and result in a 104-fold enhancement in the hard x-ray yield compared to plain solid targets. These observations lead to novel high-energy x-ray sources that have implications to lithography, imaging and medical applications.

11.
Artigo em Inglês | MEDLINE | ID: mdl-25974597

RESUMO

In a previous paper [M. Kundu, Phys. Plasmas 21, 013302 (2014)], fractional collisional absorption (α) of laser light in underdense plasma was studied by using a classical scattering model of electron-ion collision frequency ν(ei), where total velocity v=√[v(th)(2)+v(0)(2)] (with v(th) and v(0) as the thermal and the ponderomotive velocity of an electron) dependent Coulomb logarithm lnΛ(v) was shown to be responsible for the anomalous (unconventional) increase of ν(ei) and α(∝ν(ei)) with the laser intensity I(0) up to a maximum value about an intensity I(c) in the low temperature (T(e)<15eV) regime and a conventional ≈I(0)(-3/2) decrease when I(0)≫I(c). One may object that the anomalous increase in ν(ei) and α were partly due to the artifact introduced in lnΛ through the maximum cutoff distance b(max)∝v. In this work, we show similar anomalous increase in ν(ei) and α versus I(0) (in the low temperature and underdense density regime) with more accurate quantum and classical kinetic models of ν(ei) without using lnΛ, but with a proper choice of the total velocity dependent inverse cutoff length k(max)∝v(2) (classical) or k(max)∝v (quantum). For a given I(0)<5×10(14)Wcm(-2), ν(ei) versus T(e) also exhibits so far unnoticed identical anomalous increase as ν(ei) versus I(0), even if the conventional k(max)∝v(th)(2) or k(max)∝v(th) (without v(0)) is chosen. The total velocity dependent k(max) in the kinetic models, as proposed here, is found to explain the anomalous increase of α with I(0) measured in some earlier laser-plasma experiments.

12.
J Hosp Infect ; 90(3): 263-6, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25799481

RESUMO

Contact precautions may have an adverse effect on a patient's hospital experience and the delivery of care. This case-control study compared patient satisfaction scores between 70 patients isolated for MRSA and 139 non-isolated patients. Based on an adjusted analysis, there was no difference in patient satisfaction between the two groups. Age and educational status were found to affect patient satisfaction.


Assuntos
Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Satisfação do Paciente , Infecções Estafilocócicas/prevenção & controle , Precauções Universais/métodos , Estudos de Casos e Controles , Feminino , Humanos , Modelos Logísticos , Masculino , Isolamento de Pacientes , Estudos Prospectivos , Estudos Retrospectivos , Inquéritos e Questionários , Estados Unidos
13.
Sci Rep ; 4: 6002, 2014 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-25102948

RESUMO

Intense laser produced plasmas generate hot electrons which in turn leads to ion acceleration. Ability to generate faster ions or hotter electrons using the same laser parameters is one of the main outstanding paradigms in the intense laser-plasma physics. Here, we present a simple, albeit, unconventional target that succeeds in generating 700 keV carbon ions where conventional targets for the same laser parameters generate at most 40 keV. A few layers of micron sized bacteria coating on a polished surface increases the laser energy coupling and generates a hotter plasma which is more effective for the ion acceleration compared to the conventional polished targets. Particle-in-cell simulations show that micro-particle coated target are much more effective in ion acceleration as seen in the experiment. We envisage that the accelerated, high-energy carbon ions can be used as a source for multiple applications.


Assuntos
Bactérias/metabolismo , Lasers , Carbono/química , Carbono/metabolismo , Escherichia coli/metabolismo , Hidrodinâmica , Íons/química , Prótons
14.
Opt Express ; 20(5): 5754-61, 2012 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-22418381

RESUMO

We demonstrate that the interaction of intense femtosecond light on a plain solid substrate can be substantially altered by a few micron layer coating of bacterial cells, live or dead. Using E. Coli cells, we show that at an intensity of 10(16)W cm(-2), the bremsstraahlung hard x-ray emission (up to 300 keV), is increased by more than two orders of magnitude as compared to a plain glass slab. Particle-in-cell simulations carried out by modeling the bacterial cells as ellipsoidal particles show that the hot electron generation is indeed enhanced by the presence of microstructures. This new methodology should pave way for using microbiological systems of varied shapes to control intense laser produced plasmas for EUV/x-ray generation.


Assuntos
Rastreamento de Células/instrumentação , Escherichia coli/citologia , Lasers , Lentes , Intensificação de Imagem Radiográfica/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento
15.
Clin Microbiol Infect ; 13(2): 146-152, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17328726

RESUMO

Tuberculosis (TB) infections in India account for one-third of the global burden, making it important to develop speedy, cost-effective diagnostic tools. This study evaluated recombinant RD1-encoded antigens of Mycobacterium tuberculosis as tools for serodiagnosis by determining the immunological reactivity of these proteins against sera from healthy, bacille Calmette-Guérin (BCG)-vaccinated and TB-infected individuals from Kolkata. Rv3872, Rv3875 (ESAT-6) and Rv3878 were able to discriminate healthy BCG-vaccinated controls from TB patients. Rv3872 showed the highest level of antibody response in comparison with other antigens, and also showed statistically significant differences between pulmonary (p <0.0001) or extra-pulmonary (p <0.001) TB patients and healthy BCG-vaccinated individuals. The levels of antibody were measured using 20-mer overlapping peptides spanning the entire Rv3872 sequence. The immunological reactivity against a mixture of two peptides (P8 and P9) encompassing amino-acids 57-84 correlated well with that obtained using full-length Rv3872. This result was explained by the fact that two of the predicted regions of high antigenicity lie within amino-acid residues 57-85 of Rv3872. The high sensitivity and specificity of Rv3872, as well as the mixture of two synthetic overlapping peptides derived from Rv3872, highlight their potential and argue in favour of their use in serodiagnosis of both pulmonary and extra-pulmonary TB.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/imunologia , Tuberculose/diagnóstico , Antígenos de Bactérias/genética , Antígenos de Bactérias/isolamento & purificação , Vacina BCG/imunologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Humanos , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Sensibilidade e Especificidade , Testes Sorológicos , Tuberculose/imunologia , Vacinas contra a Tuberculose/imunologia
16.
Artigo em Inglês | AIM (África) | ID: biblio-1256199

RESUMO

Rhus semialata Murr. (Anacardiaceae) is a deciduous tree of north eastern India. The fruit of this plant is traditionally used to control diarrhoea and dysentery. The Present study was undertaken to evaluate anti-diarrhoeal potency of methanol extract of fruits of R. semialatalts indicated that the methanol extract of the fruits of R. semialata possesses significant anti-diarrhoeal effect and substantiated the use of this herbal remedy as a non-specific treatment for diarrhoea in folk medicine


Assuntos
Antidiarreicos , Difenoxilato , Extratos Vegetais , Ratos , Rhus
17.
Phys Rev Lett ; 96(12): 123401, 2006 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-16605903

RESUMO

Rare-gas or metal clusters are known to absorb laser energy very efficiently. Upon cluster expansion, the Mie plasma frequency may become equal to the laser frequency. This linear resonance has been well studied both experimentally and theoretically employing pump probe schemes. In this work, we focus on the few-cycle regime or the early stage of the cluster dynamics, where linear resonance is not met but, nevertheless, efficient absorption of laser energy persists. By retrieving time-dependent oscillator frequencies from particle-in-cell simulation results, we show that nonlinear resonance is the dominant mechanism behind outer ionization and energy absorption in near infrared laser-driven clusters.

19.
Protein J ; 24(1): 27-35, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15756815

RESUMO

We have quantitatively characterized by FT-IR spectroscopy the contents of secondary structure of beta-lactoglobulin during thermal unfolding and subsequent refolding. Our data clearly indicate that considerable amount of secondary structure, particularly beta-sheet, still remained intact even at 90 degrees C. Noticeable changes in secondary structure of beta-lactoglobulin were observed only above 70 degrees C. The refolded protein regained, within limits of experimental error, all of the secondary structure lost during thermal unfolding. The data also indicate that the refolding mechanism operating at pH 7.0 and 2.0 are the same. Identical secondary structure of native and refolded beta-lactoglobulin was also indicated by far-UV circular dichroic spectra of the two forms of protein. Near UV circular dichroic spectra of the same two forms showed considerable differences indicating less tertiary structure of refolded beta-lactoglobulin. The combined CD and FT-IR data indicated that refolded form of beta-lactoglobulin could be characterized as a molten globule state as it had native-like secondary structure and compromised tertiary structure.


Assuntos
Temperatura Alta , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Dobramento de Proteína , Dicroísmo Circular , Conformação Proteica , Desnaturação Proteica , Renaturação Proteica , Estrutura Secundária de Proteína , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
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