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1.
Cryo Letters ; 44(6): 327-332, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38311926

RESUMO

BACKGROUND: Antioxidant present in sperm cells protects them from oxidative damage. However, sperm are more susceptible to peroxidative damages due to the loss of these enzymes during cryopreservation and their survival and fertility may be compromised. Insulin like growth factor-1 (IGF-1) has an antioxidant effect and could maintain sperm motility. OBJECTIVE: To improve seminal parameters, mitochondrial membrane potential (MMP), oxidative status and DNA integrity of buck semen after freeze-thawing by fortification of goat semen diluent with various concentrations of IGF-1. MATERIALS AND METHODS: Fifty ejaculates were collected and were extended with tris- citric acid- fructose diluent with 10% egg yolk and 6% glycerol with sperm concentrations of 1×108 mL-1. Post-cryopreserved sperm were assessed for motility and a range of other functional parameters. RESULTS: In post-thaw semen sperm motility, live sperm count, acrosome integrity, hypo-osmotic swelling positive spermatozoa, malondialdehyde (MDA), protein carbonyl content (PCC), TUNEL positive sperm differed significantly (P<0.05) with the various concentrations of IGF-1 used. Sperm functional parameters post-thawing were significantly (P<0.05) better in 250 ng/mL IGF-1. IGF-1 protects against lipid peroxidation by lowering MDA and PCC production, thus reducing the harmful effect of reactive oxygen species. The kidding percentage using the artificial insemination technique was significantly higher ( i.e., 40%) in the group supplemented with 250 ng/mL of IGF-1 than in the non-supplemented group (i.e., 30%). CONCLUSION: IGF-1 may be used to improve post-thaw semen quality and fertility as measured by actual kidding rate. Doi.org/10.54680/fr23610110312.


Assuntos
Preservação do Sêmen , Sêmen , Animais , Masculino , Análise do Sêmen , Potencial da Membrana Mitocondrial , Cabras , Fator de Crescimento Insulin-Like I/farmacologia , Fragmentação do DNA , Carbonilação Proteica , Motilidade dos Espermatozoides , Criopreservação/métodos , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Espermatozoides , Antioxidantes/farmacologia
2.
Malays J Pathol ; 45(1): 139-143, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37119255

RESUMO

INTRODUCTION: PMCT is superior to autopsy for identification of intravascular or extravascular gas pockets and their distribution. However, differentiation between air embolism and putrefactive gas can prove challenging due to overlapping imaging findings. CASE REPORT: We report a case of a healthy young man who was involved in a fight, sustained a slash wound to the right side of his head by a kitchen knife and died at the scene. Pre-autopsy PMCT demonstrated complex fractures of the right mastoid bone extending to the right petrous apex and jugular bulb, exposing the right sigmoid sinus. There was also asymmetric intravascular air distribution suspicious of air embolism with ancillary findings of traumatic carotid-jugular pseudoaneurysm and arteriovenous fistulous formation. Post-mortem examination revealed a slash wound measuring 12x2 cm at the right side of the head, cutting through the scalp, right temporal bone, right temporal meninges, right sigmoid venous sinus and part of the right occipital lobe. No intracranial haemorrhage was found on both PMCT and autopsy. DISCUSSION: PMCT findings of air embolism versus putrefactive air on PMCT are discussed in this case. Detailed history on mechanism, circumstances, time of death and careful analysis of intravascular and extravascular air distribution patterns on PMCT are essential in guiding differentiation of true fatal air embolism and "normal" post-mortem putrefactive air. Needless to say, it is recommended that PMCT be performed as early as possible after death to reduce the chances and presence of artifactual decomposition changes.


Assuntos
Fístula Arteriovenosa , Embolia Aérea , Masculino , Humanos , Embolia Aérea/etiologia , Tomografia Computadorizada por Raios X/métodos , Autopsia/métodos
3.
Phys Rev Lett ; 129(22): 221802, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493447

RESUMO

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46} cm^{2} (90% C.L.) at DM mass of 10 MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14 MeV/c^{2} for the massless dark photon and bound DM final state, respectively.


Assuntos
Núcleo Celular , Fótons
4.
Parasitol Res ; 121(12): 3477-3493, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36222955

RESUMO

The present investigation was aimed to study the sequence, phylogenetic and haplotype analyses of Toxocara cati based on the ITS region, along with the genetic diversity, demographic history and population-genetic structure. The maximum likelihood tree based on Kimura 2-parameter model was constructed using the complete ITS region of all the nucleotide sequences (n = 57) of Toxocara spp. and other related ascarid worms available in the GenBank™. It placed all the sequences of T. cati into four major clades designated as T. cati genotypes 1-4 (TcG1-G4). A total of 66 signature nucleotides were identified in the ITS region between genotypes. The median-joining haplotype network displayed a total of 24 haplotypes, with China exhibiting the highest number of haplotypes (h = 20) followed by India (h = 4), and Japan and Russia (h = 1). It indicated a clear distinction between all the four genotypes. The pairwise FST values between all the genotypes indicated huge genetic differentiation (> 0.25) between different T. cati genotypes. Moreover, the gene flow (Nm) between T. cati genotypes was very low. Results of AMOVA revealed higher genetic variation between genotypes (92.82%) as compared to the variation within genotypes (7.18%). The neutrality indices and mismatch distributions for the G1-G4 genotypes, Indian isolates and the overall dataset of T. cati indicated either a constant population size or a slight population increase. The geographical distribution of all the genotypes of T. cati is also reported. This is the first report of genotyping of T. cati on the basis of the ITS region.


Assuntos
Variação Genética , Toxocara , Animais , Filogenia , Toxocara/genética , China , Índia , Japão , Haplótipos
5.
Zygote ; 29(1): 49-58, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33004105

RESUMO

This study was carried out to compare the efficacy of different methods to activate buffalo A + B and C + D quality oocytes parthenogenetically and to study the in vitro developmental competence of oocytes and expression of some important genes at the different developmental stages of parthenotes. The percentage of A + B oocytes (62.16 ± 5.06%, range 53.8-71.3%) was significantly higher (P < 0.001) compared with that of C + D oocytes (37.8 ± 5.00%, range 28.6-46.1%) retrieved from slaughterhouse buffalo ovaries. Among all combinations, ethanol activation followed by culture in research vitro cleave medium gave the highest cleavage and blastocyst yields for both A + B and C + D grade oocytes. Total cell numbers, inner cell mass/trophectoderm ratio and apoptotic index of A + B group blastocysts were significantly different (P < 0.05) from their C + D counterpart. To determine the status of expression patterns of developmentally regulated genes, the expression of cumulus-oocyte complexes, fertilization, developmental competence and apoptotic-related genes were also studied in parthenogenetically produced buffalo embryos at different stages, and indicated that the differential expression patterns of the above genes had a role in early embryonic development.


Assuntos
Búfalos , Oócitos , Animais , Blastocisto , Desenvolvimento Embrionário , Fertilização in vitro , Indicadores e Reagentes , Partenogênese
6.
Cryo Letters ; 42(3): 137-145, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33970991

RESUMO

BACKGROUND: Defensins are antimicrobial peptides and uniformly spans the entire sperm surface and is not exclusive to a specific domain. Goat ß-defensin-1 helps in initiation of motility and capacitation of sperm. OBJECTIVE: To know the status of ß-defensin-1 in blood, semen and its effect on post thaw fertility gene expression in Indian goat breeds. MATERIALS AND METHODS: Semen was extended and divided for estimation of ß-defensin-1 and cryopreserved having different concentrations of ß-defensin-1. RESULTS: Bet defensin-1 concentration (pg/mL) in neat semen, sperm pellet and seminal plasma was significantly higher (P< 0.05) in goat breed Barbari followed by Jamunapari and Jakhrana. ß-defensing-1 was also high in Jakhrana blood followed by Barbari and Jamunapari. The post thaw motility, live sperm, acrosome intactness and hypo osmotic swelled sperms were significantly higher (P< 0.05) with 10 ng/mL ß-defensin in the semen dilutor. CONCLUSION: Beta defensin (10 ng/mL) in semen dilutor may be used as immuno-modulator to get better post thaw quality suitable for artificial insemination.


Assuntos
Criopreservação , Fertilidade , Cabras , Preservação do Sêmen , beta-Defensinas , Animais , Criopreservação/veterinária , Fertilidade/genética , Expressão Gênica , Cabras/genética , Masculino , Sêmen , Preservação do Sêmen/veterinária , Motilidade dos Espermatozoides/genética , Espermatozoides , beta-Defensinas/genética
7.
Trop Anim Health Prod ; 53(3): 403, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34268607

RESUMO

Feed constitutes about 60-70% of the total cost of poultry production. So maximizing the feed efficiency will reduce production cost. The rapid growth in the juvenile period is essential to achieve higher body weight. Therefore, identifying the genes and pathways involved in rapid growth at an early age with a lesser requirement of feed is of utmost importance to further economize the broiler production. The efficiency of feed utilization was measured using RFI (residual feed intake). The present study aimed to estimate the RFI (0-5 week) in a population of indigenously developed colored broiler sire line chicken as well as identifying the differentially expressed genes influencing RFI in high and low RFI groups. The liver samples of high and low RFI broiler chicken aged 35 days were used for microarray analysis. A total of 2798 differentially expressed genes (DEGs) were identified, out of which 913 genes were downregulated and 1885 were upregulated. The fold change varied from - 475.17 to 552.94. A subset of genes was confirmed by qRT-PCR, and outcomes were matched well with microarray data. In the functional annotation study of DEGs, the highest significant GO (Gene Ontology) terms in the biological process included protein transport, protein localization, regulation of apoptosis, and mitochondrial transport. Gene network analysis of these DEGs plays an important role to understand the interaction among genes. Study of the important genes which were differentially expressed and the related molecular pathways in this population may hold the potential for future breeding strategies for augmenting feed efficiency.


Assuntos
Ração Animal , Galinhas , Ração Animal/análise , Animais , Galinhas/genética , Ingestão de Alimentos , Expressão Gênica , Fígado
8.
Reprod Fertil Dev ; 32(5): 508-521, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31959280

RESUMO

Expression levels of 13 microRNAs (miRNAs) were compared between buffalo blastocysts produced by somatic cell nuclear transfer through hand-made cloning and IVF to improve cloning efficiency. Expression of miR-22, miR-145, miR-374a and miR-30c was higher, whereas that of miR-29b, miR-101, miR-302b, miR-34a, miR-21 and miR-25 was lower, in nuclear transferred (NT) than IVF embryos; the expression of miR-200b, miR-26a and miR-128 was similar between the two groups. Based on these, miR-145, which is involved in the regulation of pluripotency, was selected for further investigation of NT embryos. miR-145 expression was lowest at the 2-cell stage, increased through the 4-cell stage and was highest at the 8-cell or morula stage in a pattern that was similar between NT and IVF embryos. miR-145 expression was higher in NT than IVF embryos at all stages examined. Treatment of reconstructed embryos 1h after electrofusion with an inhibitor of miR-145 for 1h decreased the apoptotic index and increased the blastocyst rate, total cell number, ratio of cells in the inner cell mass to trophectoderm, global levels of acetylation of histone 3 at lysine 18 and expression of Krueppel-like factor 4 (KLF4), octamer-binding transcription factor 4 (OCT4) and SRY (sex determining region Y)-box 2 (SOX2) in blastocysts. Treatment with an miR-145 mimic had the opposite effects. In conclusion, treatment of NT embryos with an miR-145 inhibitor improves the developmental competence and quality, and increases histone acetylation and expression of pluripotency-related genes.


Assuntos
Apoptose , Blastocisto/fisiologia , Búfalos/fisiologia , Epigênese Genética , Fertilização in vitro , MicroRNAs/antagonistas & inibidores , Técnicas de Transferência Nuclear/veterinária , Acetilação , Animais , Blastocisto/metabolismo , Técnicas de Cultura Embrionária/veterinária , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Histonas/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Gravidez
9.
Phys Rev Lett ; 123(22): 221301, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31868422

RESUMO

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6 GeV/c^{2} among WIMP AM measurements to date.

10.
Phys Rev Lett ; 123(16): 161301, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31702340

RESUMO

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35} cm^{2} for TI analysis at m_{χ}∼50-180 MeV/c^{2}, and 3×10^{-32}∼9×10^{-38} cm^{2} for AM analysis at m_{χ}∼75 MeV/c^{2}-3.0 GeV/c^{2}.

11.
Photochem Photobiol Sci ; 18(1): 224-231, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30444520

RESUMO

The development of UV-B protective mechanisms in aquacultural species is essential for the sustainable production of healthy aqua crop. Freshwater carp Catla catla larvae (13.5 ± 1.12 mg) were fed with a diet containing 0.5% vitamin C (D1) and a control diet (D2) for 40 days. Each group was exposed to two doses of UV-B irradiation: 360 (5 min, D15 min and D25 min) and 720 mJ cm-2 (10 min, D110 min and D210 min) for 15 days. Significantly (p < 0.05) higher survival and average weight were recorded in D1 compared to D2 exposed to the same dose. Also, significantly (p < 0.001) higher nitric oxide synthase and lower thiobarbituric acid reactive substances and heat shock protein 70 levels were recorded in D15 min compared to the other groups. A direct relationship was found between the dose of UV-B and DNA fragmentation in muscles. DNA damage indices such as tail DNA, tail extent moment and olive tail moment were significantly (p < 0.01) lower in D15 min. Thus, supplementation of vitamin C in the diet provides UV-B protection to larvae.


Assuntos
Ácido Ascórbico/farmacologia , Carpas/crescimento & desenvolvimento , Suplementos Nutricionais , Proteção Radiológica , Protetores Solares/farmacologia , Raios Ultravioleta/efeitos adversos , Animais , Antioxidantes/farmacologia , Fragmentação do DNA/efeitos dos fármacos , Fragmentação do DNA/efeitos da radiação , Proteínas de Choque Térmico HSP70/metabolismo , Larva/efeitos da radiação , Modelos Animais , Óxido Nítrico Sintase/metabolismo , Tiobarbitúricos/metabolismo
12.
Environ Geochem Health ; 41(5): 1923-1937, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30719612

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) (Ba, Zn, Pb, Cu, Cr, Ni, As, Co) were determined in the road dusts of a coal mining area (Dhanbad, India) to assess their content and potential human health risks. Dust samples were collected from sign boards of the heavy traffic road connecting Dhanbad and Sindri. The total PAHs (∑PAHs, all values in mg/kg) content in the road dust samples varied from 3.98 to 13.1, with carcinogenic PAHs content of 14.8-34.4% of the ∑PAHs. Phenanthrene (2.72), fluorene (0.715) and pyrene (0.575) are the major PAHs. Principal component analysis revealed that these PAHs are probably originated from pyrogenic (coal combustion and traffic emission) and petrogenic (coal dust, tyre and road particles) sources. Among the PTEs, the mean content was higher for Ba (293 mg/kg) followed by Zn (224), Pb (128), Cu (52.6), Cr (45.2), Ni (22.0), As (17.5) and Co (8.11). The overall pollution load index varied from 0.43 to 1.0. Source analysis showed that PTEs in the road dust of the study site were derived from traffic emission (Zn, Fe, Mn, Co and Pb), coal dust (Cr, As and Ni) and soil (K, Mg, Ba, Sr and Ca). In general, the PTEs are lower, but the PAHs contents were elevated in the road dust samples. Although the exposure risks from PTEs are low, the risk to children (expressed as hazardous quotient) for As and Pb is near to the permissible limit of 1.0. Cancer risk from PAHs for adult (4.8 × 10-6) and child (5.3 × 10-6) has exceeded the acceptable limit of 10-6.


Assuntos
Minas de Carvão , Poeira/análise , Exposição Ambiental/análise , Poluentes Ambientais/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Carcinógenos/análise , Carvão Mineral/análise , Monitoramento Ambiental , Humanos , Índia , Medição de Risco
13.
Phys Rev Lett ; 120(24): 241301, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29956956

RESUMO

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36} cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5 GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2 GeV/c^{2}.

14.
Reprod Domest Anim ; 53(4): 986-996, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29733525

RESUMO

Incomplete or aberrant reprogramming of nuclear genome is one of the major problems in somatic cell nuclear transfer. In this study, we studied the effect of histone deacetylase inhibitor m-carboxycinnamic acid bishydroxamide (CBHA) on in vitro development of buffalo embryos produced by Hand-made cloning. Cloned embryos were treated with CBHA (0, 5, 10, 20 or 50 µM) for 10 hr from the start of reconstruction till activation. At 10 µM, but not at other concentrations examined, CBHA increased (p < .05) the blastocyst rate (63.77 ± 3.97% vs 48.63 ± 3.55%) and reduced (p < .05) the apoptotic index of the cloned blastocysts (8.91 ± 1.94 vs 4.36 ± 1.08) compared to untreated controls, to levels similar to those in IVF blastocysts (4.78 ± 0.74). CBHA treatment, at all the concentrations examined, increased (p < .05) the global level of H3K9ac in cloned blastocysts than in untreated controls to that observed in IVF blastocysts. Treatment with CBHA (10 µM) decreased (p < .05) the global level of H3K27me3 in cloned blastocysts than in untreated controls but it was still higher (p < .05) than in IVF blastocysts. CBHA (10 µM) treatment increased (p < .05) the relative expression level of pluripotency-related genes OCT-4 and NANOG, and anti-apoptotic gene BCL-XL, and decreased (p < .05) that of pro-apoptotic gene BAX than in untreated controls but did not affect the relative expression level of apoptosis-related genes p53 and CASPASE3 and epigenetics-related genes DNMT1, DNMT3a and HDAC1. These results suggest that treatment of cloned embryos with 10 µM CBHA improves the blastocyst rate, reduces the level of apoptosis and alters the epigenetic status and gene expression pattern.


Assuntos
Apoptose/efeitos dos fármacos , Búfalos/embriologia , Cinamatos/farmacologia , Clonagem de Organismos , Técnicas de Cultura Embrionária/veterinária , Embrião de Mamíferos/efeitos dos fármacos , Animais , Cinamatos/administração & dosagem , Relação Dose-Resposta a Droga , Epigênese Genética/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos
15.
Small Rumin Res ; 165: 124-130, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30078954

RESUMO

Goats are adaptable to varied farming environments and contribute significantly towards sustainable livestock production and food security. Selective breeding of goats for improved performance is an important component of sustainable production. The objectives of the present study were to determine the most appropriate models of analysis for growth traits, to estimate genetic parameters, survival potential of kids from birth to 12 months of age and to estimate genetic trends for growth traits of Jamunapari kids at different ages. Genetic parameter estimates were obtained from 6590 records generated between 1982 and 2012 from 5922 animals with a pedigree covering over 13 generations. The most parsimonious model for early growth traits included permanent environmental effects due to the dam (PE) and litter effects. Similarly, the most appropriate model for early average daily gain (ADG) between birth and 3 or 6 months also included PE and litter effects. The estimates of heritability for survival from birth to 12 months of age ranged from 0.10 to 0.43. The estimates of heritability for ADG varied from 0.04 to 0.41. In general, higher estimates of heritability were observed when a sire model was fitted in the random effect. There was no genetic variation observed for survival between birth and 3 months of age. However, heritability estimates of between 0.18 and 0.39 were observed for survivability during post-weaning period to 12 months of age. The genetic trend at 9 months of age and 12 months of age was 0.144 kg 0.189 kg per year respectively. The genetic trend at all the ages was positive during the study period.

16.
Langmuir ; 33(20): 4890-4902, 2017 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-28463002

RESUMO

We report titania nanoheterostructures decorated with silver, exhibiting tuneable photochromic properties for the first time when stimulated only by visible white light (domestic indoor lamp), with no UV wavelengths. Photochromic materials show reversible color changes under light exposure. However, all inorganic photochromic nanoparticles (NPs) require UV light to operate. Conventionally, multicolor photochromism in Ag-TiO2 films involves a change in color to brownish-gray during UV-light irradiation (i.e., reduction of Ag+ to Ag0) and a (re)bleaching (i.e., (re)oxidation of Ag0 to colorless Ag+) upon visible-light exposure. In this work, on the contrary, we demonstrate visible-light-induced photochromism (ranging from yellow to violet) of 1-10 mol % Ag-modified titania NPs using both spectroscopic and colorimetric CIEL*a*b* analyses. This is not a bleaching of the UV-induced color but a change in color itself under exposure to visible light, and it is shown to be a completely different mechanism-driven by the interfacial charge transfer of an electron from the valence band of TiO2 to that of the AgxO clusters that surround the titania-to the usual UV-triggered photochromism reported in titania-based materials. The quantity of Ag or irradiation time dictated the magnitude and degree of tuneability of the color change, from pale yellow to dark blue, with a rapid change visible only after a few seconds, and the intensity and red shift of surface plasmon resonance induced under visible light also increased. This effect was reversible after annealing in the dark at 100 °C/15 min. Photocatalytic activity under visible light was also assessed against the abatement of nitrogen oxide pollutants, for interior use, therefore showing the coexistence of photochromism and photocatalysis-both triggered by the same wavelength-in the same material, making it a multifunctional material. Moreover, we also demonstrate and explain why X-ray photoelectron spectroscopy is an unreliable technique with such materials.

17.
Luminescence ; 32(5): 839-844, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28067013

RESUMO

Nanophosphors of (Sr0.98-x Mgx Eu0.02 )2 SiO4 (x = 0, 0.18, 0.38, 0.58 and 0.78) were prepared through low temperature solution combustion method and their luminescence properties were studied. The emission peak for Eu2+  -doped Sr2 SiO4 nanophosphor is observed at ~490 nm and ~553 nm corresponding to two Sr2+ sites Sr(I) and Sr(II) respectively for 395 nm excitation. However the addition of Mg2+ dopant in Sr2 SiO4 leads to suppression of ~553 nm emission peak due to absence of energy levels of Sr (II) sites which results in a single broad emission at ~460 nm. It was shown that the emission peak blue shifted with increase in Mg concentration which may be attributed to change in crystal field environment around Sr(I) sites. Therefore, the (Mg0.78 Sr0.20 Eu0.02 )2 SiO4 nanophosphor can be used for blue emission and the Sr2 SiO4 :Eu0.042+ for green-yellow emission at 395 nm excitations. The Commission International de L'Eclairage (CIE) chromaticity coordinates for mixed powders of (Mg0.78 Sr0.20 Eu0.02 )2 SiO4 and Sr2 SiO4 :Eu0.042+ (in a 1:1 ratio) fall in the white region demonstrating the possible use of the mixture in white light generation using near-UV excitation source.


Assuntos
Substâncias Luminescentes/química , Medições Luminescentes/métodos , Magnésio/química , Cor , Európio/química , Microscopia Eletrônica de Varredura , Nanoestruturas/química , Tamanho da Partícula , Estrôncio/química , Difração de Raios X
18.
Luminescence ; 32(1): 35-42, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27118686

RESUMO

We present here a systematic investigation on the interaction between a water-soluble alloyed semiconductor quantum dot and bovine serum albumin using various spectroscopic techniques i.e. fluorescence quenching, resonance light scattering and synchronous fluorescence spectroscopy. The analysis of fluorescence spectrum and fluorescence intensity indicates that the intrinsic fluorescence of bovine serum albumin (BSA) gets quenched by both static and dynamic quenching mechanism. The Stern-Volmer quenching constants, energy transfer efficiency parameters, binding parameters and corresponding thermodynamic parameters (ΔH0 , ΔS0 and ΔG0 ) have been evaluated by using van 't Hoff equation at different temperatures. A positive entropy change with a positive enthalpy change was observed suggesting that the binding process was an entropy-driven, endothermic process associated with the hydrophobic effect. The intermolecular distance (r) between donor (BSA) and acceptor (CdSeS/ZnS quantum dots) was estimated according to Förster's theory of non-radiative energy transfer. The synchronous fluorescence spectra revealed a blue shift in the emission maxima of tryptophan which is indicative of increasing hydrophobicity. Negative ΔG0 values implied that the binding process was spontaneous. It was found that hydrophobic forces played a role in the quenching process. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Compostos de Cádmio/química , Pontos Quânticos , Compostos de Selênio/química , Soroalbumina Bovina/química , Sulfetos/química , Compostos de Zinco/química , Animais , Bovinos , Solubilidade , Espectrometria de Fluorescência , Termodinâmica , Água/química
19.
Med J Armed Forces India ; 73(1): 85-87, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28123251

RESUMO

BACKGROUND: Intrauterine contraceptive device is a popular and effective method of contraception. It can be inserted either as an interval procedure or after abortion or delivery. Threads are attached to the vertical limb so that the user can find out the location of the device. Sometimes the threads are not palpable by the user; this study was conducted to find out the reasons for inability to palpate the threads. METHODS AND RESULTS: The retrospective study was conducted over a period of eight years; 110 female patients who complained of inability to feel the threads were included in the study. In most of the cases the device was in the right place. In four cases the device could not be felt on uterine sounding; this could have been due to subendometrial placement of the device. There was no case of perforation by the device. CONCLUSION: Inability to feel the threads is a common complaint by the patients who are using intrauterine contraceptive device. In most of the cases the device was in correct position and could be localized by clinical examination. Ultrasonography can help in localization of the device; if used at the time of insertion it can confirm proper insertion and location of the device. This will reassure the client and the health care providers.

20.
Surf Sci ; 646: 5-12, 2015 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-27279673

RESUMO

We have deposited 4-aminophenol on Pt(111) surfaces in ultra-high vacuum and studied the strength of its adsorption through a combination of STM, LEED, XPS and ab initio calculations. Although an ordered (2√3×2√3)R30° phase appears, we have observed that molecule-substrate interaction dominates the adsorption geometry and properties of the system. At RT the high catalytic activity of Pt induces aminophenol to lose the H atom from the hydroxyl group, and a proportion of the molecules lose the complete hydroxyl group. After annealing above 420K, all deposited aminophenol molecules have lost the OH moiety and some hydrogen atoms from the amino groups. At this temperature, short single-molecule oligomer chains can be observed. These chains are the product of a new reaction that proceeds via the coupling of radical species that is favoured by surface diffusion.

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