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Environmental Exposure to Lead as a Risk for Prostate Cancer

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biomedical and Environmental sciences 2002年第4期15卷 298-305页

作者： M．k．j．sIDDIQUI s．srivastava 等 IndustialToxicologyReserachCentre PostBoxNo.80.M.G.Marg.Lucknow226－001India Dr RMLAvadhUniversityFaizabad－224001India

Objective To evaluate the possible role of environmental exposure to lead as a risk factor for prostate pathology in patients suffering from prostate cancer (PCA) and benign prostate hyperplasia (bPH). Methods blood lead (bPb) level was determined in PCA and bPH cases using a graphite furnace Atomic Absorption spectrophotometer and compared with those in a control group living in the similar socioeconomic environment. Results bPb was significantly higher in PCA and bPH cases than in normals (Pblood levels of zinc and copper were significantly lower in PCA and bPH cases when compared with controls (Ps, a statistically significant positive correlation between lead and thiobarbituric acid reactive substances (TEARs) measured as malondialdehyde, and negative correlation between blood lead and antioxidant GsH level, indicative of possible generation of reactive oxygen species, were also observed after adjusting for age as a possible confounders. However, positive association between blood lead and TEARs was relatively higher in PCA patients (r=0.77, PbPH (r=0.32, Psion These results with limited power seem to suggest for the first time that environmental exposure of aging males to lead may be a risk factor for prostate cancer and/or benign prostate hyperplasia possibly through generation of reactive oxygen species and/or reducing the level of zinc which acts as a cellular growth protector.

关键词： benign prostate hyperplasia Prostate cancer blood lead Atomic Absorption spectrophotometer

synthesis and enhanced photoluminescence properties of red emitting divalent ion(Ca^(2+))doped Eu:Y_(2)O_(3)nanophosphors for optoelectronic applications

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journal of Rare Earths 2022年第8期40卷 1187-1198页

作者： Arpita Dwivedi Monika srivastava Ankur Dwivedi Amit srivastava Anurag Mishra s.k.srivastava Department of Physics Institute of ScienceBanaras Hindu University(BHU)Varanasi221005India school of Materials science and Technology Indian Institute of Technology(BHU)Varanasi221005India Department of Mining Engineering Indian Institute of Technology(BHU)Varanasi221005India Department of Physics TDPG College VBS Purvanchal UniversityJaunpur222001India

This work presents the synthesis of Y_(2)O_(3):Eu^(3+),χCa^(2+)(χ=0 mol%,1 mol%,3 mol%,5 mol%,7 mol%,9 mol%,11 mol%)nanophosphors with enhanced photoluminescence properties through a facile solution combustion method for optoelectronic,display,and lighting *** X-ray diffraction(XRD)patterns of the proposed nanophosphor reveal its structural properties and crystalline *** transmission electron microscope(TEM)results confirm the change in the shape of the particle and aggregation of particles after co-doping with Ca^(2+).Fourier transform infrared spectroscopy(FTIR)and Raman vibrations also confirm the presence of Y-O vibration and subsequently explain the crystalline nature,structural properties,and purity of the *** the synthesized nanophosphors samples emit intense red emission at 613 nm(~5D_(0)→~7 F_(2))under excitation with 235,394 and 466 nm wavelengths of Eu^(3+)*** photoluminescence(PL)emission spectra excited with 235 nm illustrate the highest emission peak with two other emission peaks excited with 466 and 394 nm that is 1.4 times higher than 466 nm and 1.9 times enhanced by 394 nm wavelength,*** emission intensity of Y_(2)O_(3):Eu^(3+),χCa^(2+)(5 mol%)is increased 8-fold as compared to Eu:Y_(2)O_(3).Doping with Ca^(2+)ions enhances the emission intensity of Eu:Y_(2)O_(3)nanopho sphors due to an increase in energy transfer in Ca^(2+)→Eu^(3+)through asymmetry in the crystal field and by introduction of radiative defect centers through oxygen vacancies in the yttria *** is also observed that the optical band gap and the lifetime of the~5D_(0)level of Eu^(3+)ions in Y_(2)O_(3):Eu^(3+),xCa^(2+)nanophosphor sample gets changed with a doping conce ntration of Ca^(2+)*** also reveals high thermal stability and quantum yield as estimating activation energy of 0.25 eV and 81%,***,CCT,and color purity values(>98%)show an improved red-emitting nanophosphor in the warm region of light,which m

关键词： Red emission Photoluminescence(PL) Y_(2)O_(3):Eu^(3+),xCa^(2+) Rare earths Nanophosphors LEDs

THEORY OF INTERPOLATION ON INFINITE INTERVAL—Ⅰ(UNIFORM CONVERGENCE OF sTAbLE INTERPOLATION PROCEssEs)

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Acta Mathematica scientia 1986年第4期6卷 373-378页

作者： k.b.srivastava Department of Mathematics Indian Institute of Technology kanpur-208016 India

§1. Preliminaries and Results Let us begin by defining a triangular matrix L whose n-th row consists of n distinct points xvn, v=1, n; n=1, 2, … such that 01n2n<…nn<∞. （1.1） Denote by H_n.（f, x, L）≡H_n（f, L... 详细信息

§1. Preliminaries and Results Let us begin by defining a triangular matrix L whose n-th row consists of n distinct points xvn, v=1, n; n=1, 2, … such that 01n2nby H_n.（f, x, L）≡H_n（f, L） the n-th Hermite-Fejer interpolation

关键词： THEORY OF INTERPOLATION ON INFINITE INTERVAL UNIFORM CONVERGENCE OF sTAbLE INTERPOLATION PROCEssEs

Radiation Losses in the Microwave X band in Al-Cr substituted Y-Type Hexaferrites

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Chinese Physics Letters 2017年第4期34卷 35-38页

作者： D.basandrai R.k.bedi A.Dhami j.sharma s.b.Narang k.Pubby A.k.srivastava Research scholar Department of Physics I. K. Gujral Punjab Technical University Jalandhar India Department of Physics Lovely Professional University Phagwara India principal Satyam Institute of Engineering & Technology Amritsar India Department of Electronic Technology Guru Nanak Dev University Amritsar India

We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely ba2Mg2Alx/2Crx/2Fe12-xO22 （x = 0, 0.5 and 1.0）. The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. ba2Mg2Fe12O22 hexaferrite shows radiation loss of -37.25db （99.999% loss） at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.

关键词： ba Al Radiation Losses in the Microwave X band in Al-Cr substituted Y-Type Hexaferrites Cr

seasonal Inhomogeneity of soot Particles over the Central Indo-Gangetic Plains,India:Influence of Meteorology

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journal of Meteorological Research 2015年第6期29卷 935-949页

作者： sINGH b.P. TIWARI s. HOPkE Philip k. sINGH R.s. bIsHT D.s. srivastava A.k. sINGH R.k. DUMkA U.C. sINGH A.k. RAI b.N. srivastava Manoj k. Department of Geophysics Banaras Hindu University Indian Institute of Tropical Meteorology(New Delhi branch) Clarkson University Department of Chemical Engineering Banaras Hindu University Aryabhatta Research Institute of Observational sciences Department of Physics Banaras Hindu University

black carbon（bC） particles play a unique and important role in earth’s climate *** was measured（in-situ） in the central part of the Indo-Gangetic Plains（IGP） at Varanasi,which is a highly populated and polluted region due to its topography and extensive emission *** annual mean bC mass concentration was 8.92 ± 7.0 μg m-3,with 34%of samples exceeding the average ***,bC was highest during the post-monsoon and winter periods（approximately 18 μg m-3） and lower in the premonsoon/monsoon seasons（approximately 6 μg m-3）.The highest frequency（approximately 46%） observed for bC mass was in the interval from 5 to 10 μg ***,during the post-monsoon season,the most common values（approximately 23%） were between 20 and 25 μg *** nighttime concentrations of bC were approximately twice as much as the daytime values because of lower boundary layer heights at *** Angstrom exponent was significantly positively correlated（0.55） with ground-level bC concentrations,indicating the impact of bC on the columnar aerosol *** estimated mean absorption Angstrom exponent was 1.02 ± 0.08 μg m-3,indicating that the major source of bC was from fossil fuel *** negative correlations between bC mass and meteorological parameters indicate a pronounced effect of atmospheric dynamics on the bC mass in this *** highest mean bC mass concentration（18.1 ± 6.9 μg m-3） as a function of wind speed was under calm wind conditions（38%of the time）.

关键词： black carbon Indo-Gangetic Plains absorption Angstr(o|¨)m exponent biomass fossil fuel

Combinatorial therapies for spinal cord injury repair

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Neural Regeneration Research 2025年第5期20卷 1293-1308页

作者： Carla s.sousa Andreia Monteiro António j.salgado Nuno A.silva Life and Health sciences Research Institute(ICVs) School of MedicineUniversity of MinhoCampus de Gualtar-gualtarBragaPortugal ICVs/3b’s Associate Lab PT Government Associated LabCampus de Gualtar-gualtarBragaPortugal

spinal cord injuries have profound detrimental effects on individuals, regardless of whether they are caused by trauma or non-traumatic events. The compromised regeneration of the spinal cord is primarily attributed to damaged neurons, inhibitory molecules, dysfunctional immune response, and glial scarring. Unfortunately, currently, there are no effective treatments available that can fully repair the spinal cord and improve functional outcomes. Nevertheless, numerous pre-clinical approaches have been studied for spinal cord injury recovery, including using biomaterials, cells, drugs, or technological-based strategies. Combinatorial treatments, which target various aspects of spinal cord injury pathophysiology, have been extensively tested in the last decade. These approaches aim to synergistically enhance repair processes by addressing various obstacles faced during spinal cord regeneration. Thus, this review intends to provide scientists and clinicians with an overview of pre-clinical combinatorial approaches that have been developed toward the solution of spinal cord regeneration as well as update the current knowledge about spinal cord injury pathophysiology with an emphasis on the current clinical management.

关键词： electric stimulation neural tissue regeneration neuroprotection polytherapy spinal cord injury

Nanostructural Features and Optical Performance of RF Magnetron sputtered ZnO Thin Films

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journal of Materials science & Technology 2010年第11期26卷 986-990页

作者： A.k.srivastava Praveen M.Arora s.k.Gupta b.R.Chakraborty s.Chandra s.Toyoda H.bahadur Natonal Physical Laboratory Council of Scientific and Industrial Research Indian Institute of Technology Okayama University of science

Zinc oxide （ZnO） thin films were grown on silicon substrate by RF （radio frequency） magnetron *** topography of these films exhibited a nanostructured granular appearance with the size of individual grains between 50 to 100 *** cross-sectional electron micrographs revealed columnar grains in the form of aggregated nanorods/wires with length of about 500 nm,similar to the thickness of these thin films of ZnO nucleated and grown vertically on the silicon *** resolution lattice scale imaging using high resolution transmission electron microscope （HRTEM） elucidated the single crystalline 1010 planes of hexagonal-ZnO constituting the columnar grains with the individual nanorod diameter between 3 and 4 *** photoluminescence measurements showed the prominent emission peak at around 460 nm for the blue band,normally attributed to intrinsic defects in particular interstitial zinc （Zn）.These films were further characterized by X-ray diffraction （XRD）,Fourier transform infrared spectroscopy （FTIR）,Raman spectroscopy and electron paramagnetic resonance （EPR） to evaluate various aspects on preferred growth orientations,band structures and vibrational modes originated in such fascinating nano-grained thin films of *** present investigations inferred that these films are advantageous in various potential applications for fabricating nano-scaled devices.

关键词： Electron microscopy Nanomaterials ZnO RF sputtering Photoluminescence spectroscopy Electron paramagnetic resonance

Enhanced dielectric and optical properties of nanoscale barium hexaferrites for optoelectronics and high frequency application

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Chinese Physics b 2018年第12期27卷 517-525页

作者： j Mohammed A b suleiman Tchouank Tekou Carol T H Y Hafeez jyoti sharma Pradip k Maji sachin Godara kumar A k srivastava Department of Physics School of Chemical Engineering and Physical Sciences Lovely Professional University Department of Physics Faculty of Science Federal University Dutse sRM Research Institute SRM University Department of Polymer and Processing Engineering Indian Institute of Technology Roorkee Department of Chemistry Guru Nanak Dev University

M-type barium hexaferrites with chemical composition ba1-xDyxFe12-yCryO19(x = 0.0, 0.1, 0.2, and y =0.0, 0.4, 0.5) were synthesized via sol–gel auto-combustion method. The samples were pre-sintered at 400℃ for 3 h and sintered at 950℃ for 5 h. The changes in the structural, dielectric, and optical properties were studied after the substitution of Dy3+and Cr3+ions. X-ray diffraction(XRD) analysis confirms the formation of single phase hexaferrites with the absence of secondary phase. FTIR analysis gives an idea of the formation of hexaferrites with the appearance of two peaks at 438 cm-1and 589 cm-1. The field emission scanning electron micrographs(FEsEM) show a combination of crystallites with large shapes close to hexagonal platelet-like shape and others with rice or rod-like shapes, whereas EDX and elemental analysis confirm the stoichiometry of prepared samples. The calculated band gap from UV-vis NIR spectroscopy spectra was found to decreases with increase in Dy3+–Cr3+substitution. The dielectric properties were explained on the basis of Maxwell–Wagner model. Enhancement of dielectric constant at higher frequencies was observed in all the samples. Low dielectric loss is also observed in all the samples and Cole–Cole plot shows that grain boundary resistance(Rgb) contribute most to the dielectric properties. The prepared samples exhibit properties that could be useful for optoelectronics and high frequency application.

关键词： Maxwell–Wagner model dielectric constant Cole–Cole plot optical band-gap

Ce-Co-doped biFeO_3 multiferroic for optoelectronic and photovoltaic applications

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Chinese Physics b 2017年第11期26卷 383-388页

作者： jyoti sharma Deepak basandrai A k srivastava Department of Physics Lovely Professional University

The Ce-Co-doped biFeO3 multiferroic, bi（1-x）Ce）xFe（1-x）CoxO3（x = 0.00, 0.01, 0.03, and 0.05）, has been prepared by a sol-gel auto-combustion method and analyzed through Raman spectroscopy, photoluminescence, and UV-visible spectroscopy. We have observed an anomalous intensity of the second-order Raman mode at - 1260 cm^-1 in pure bFO and suppressed intensity in doped samples, which indicates the presence of spin two-phonon coupling in these *** photoluminescence spectra show reduction in the intensity of emission with the increasing dopant concentration, which indicates the high charge separation efficiency. A sharp absorption with three charge transfer（C-T） and two d-d transitions are shown by UV-visible spectra in the visible region. The band gap of biFeO3（bFO） is decreasing with increasing dopant concentrations and the materials are suitable for photovoltaic applications.

关键词： Raman and UV-visible spectroscopy photoluminescence and photo-voltaic applications