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ENHANCED TUmORIGENEsIs BY smALL, PROTRACTED DOsEs OF DENsELY IONIZING RADIATION

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Chinese medical Journal 1994年第6期 16-21页

作者： m.m. ElkindDepartment of Radiological Health sciences, Colorado state University, Fort Collins, Colorado 80523, U.s.A.

starting with observations that were first published in 1982. a series of additional findings led to the discovery of an important property of eel's in late G2/ mitosis. In addition to being the most sensitive to killing, cells in this age-interval were also shown to be the most sensitive to radiation-induced neoplastic transformation. In this work, C3H mouse cells, designated 10T1 / 2, were irradiated with fission-spectrum neutrons and assayed in vitro via the endpoint focus formation on a monolayer of normal cells. From these observations, a biophysical model was developed to explain the anomalous finding that the frequency of transformation by low doses was enhanced when the exposure was protracted. In contrast to transformation by X- and 7-rays where repair and kinetics during exposure play dominant roles, with radiations like reactor neutrons and a-particles repair has a minimal effect; only cell kinetics acts significantly to modify transformation due to protracted doses. In this report, the lack of responsiveness of mitotic cells to promotion by the phorbol ester 12-0-tetradecanoylphorbol-13-acetate is shown further to agree with the findings with fission-neutrons and the model that, at low dose rate, enhanced transformation is due principally to the progression of cells into the window of sensitivity. Implications of this model for lung cancer due to environmental radon are also discussed.

关键词： Res rate ENHANCED TUmORIGENEsIs BY smALL PROTRACTED DOsEs OF DENsELY IONIZING RADIATION 口口 TPA

structural, electronic, elastic, and thermal properties of CaNiH3 perovskite obtained from first-principles calculations

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Chinese Physics B 2018年第3期27卷 384-390页

作者： s Benlamari H Bendjeddou R Boulechfar sAmara Korba H meradji R Ahmed s Ghemid R Khenata s Bin Omran Laboratoire LPR Departement de Physique Faculté des Sciences Université Badji Mokhtar Annaba Algeria Department of Physics Faculty of Science Universiti Teknologi Malaysia UTM Skudai 81310 Johor Malaysia Laboratoire de Physique Quantique et de modelisation mathematique de la matiere (LPQ3m) Universite de Mascara-29000-Algeria Department of Physics and Astronomy College of Science King Sand University P.O. Box 2455 Riyadh 11451 Saudi Arabia

A theoretical study of the structural, elastic, electronic, mechanical, and thermal properties of the perovskite-type hydride CaNiH3 is presented. This study is carded out via first-principles full potential （FP） linearized augmented plane wave plus local orbital （LAPW＋lo） method designed within the density functional theory （DFT）. To treat the exchange-correlation energy/potential for the total energy calculations, the local density approximation （LDA） of Perdew-Wang （PW） and the generalized gradient approximation （GGA） of Perdew-Burke-Ernzerhof （PBE） are used. The three independent elastic constants （C11, C12, and C44） are calculated from the direct computation of the stresses generated by small strains. Besides, we report the variation of the elastic constants as a function of pressure as well. From the calculated elastic constants, the mechanical character of CaNiH3 is predicted. Pertaining to the thermal properties, the Debye temperature is estimated from the average sound velocity. To further comprehend this compound, the quasi-harmonic Debye model is used to analyze the thermal properties. From the calculations, we find that the obtained results of the lattice constant （ao）, bulk modulus （Bo）, and its pressure derivative （B0′） are in good agreement with the available theoretical as well as experimental results. similarly, the obtained electronic band structure demonstrates the metallic character of this perovskite-type hydride.

关键词： perovskite-type hydrides elastic constants hydrogen storage materials

Individual stages of bacterial dichloromethane degradation mapped by carbon and chlorine stable isotope analysis

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Journal of Environmental sciences 2019年第4期31卷 147-160页

作者： maria L.Torgonskaya Anatoly m.Zyakun Yuri A.Trotsenko Kestutis s.Laurinavichius steffen Kümmel stéphane Vuilleumier Hans H.Richnow Laboratory of Radioactive Isotopes G.K.Skryabin Institute of Biochemistry and Physiology of MicroorganismsFRC Pushchino Center for Biological ResearchRussian Academy of Sciences Laboratory of mass spectrometry G.K.Skryabin Institute of Biochemistry and Physiology of MicroorganismsFRC Pushchino Center for Biological ResearchRussian Academy of Sciences Department of Isotope Biogeochemistry Helmholtz Centre for Environmental Research-UFZ Université de strasbourg CNRS

The fractionation of carbon and chlorine stable isotopes of dichloromethane(CH_2Cl_2,DCm)upon dechlorination by cells of the aerobic methylotroph methylobacterium extorquens Dm4 and by purified DCm dehalogenases of the glutathione s-transferase family was *** effects for individual steps of the multi-stage DCm degradation process,including transfer across the cell wall from the aqueous medium to the cell cytoplasm,dehalogenase binding,and catalytic reaction,were *** observed carbon and chlorine isotope fractionation accompanying DCm consumption by cell supensions and enzymes was mainly determined by the breaking of C\Cl bonds,and not by inflow of DCm into *** isotope effects of DCm dehalogenation were initially masked in high density cultures,presumably due to inverse isotope effects of non-specific DCm oxidation under conditions of oxygen *** cofactor supply remarkably affected the correlation of variations of DCm carbon and chlorine stable isotopes(Δδ^(13)C/Δδ^(37)Cl),increasing corresponding ratio from 7.2–8.6 to 9.6–10.5 under conditions of glutathione *** suggests that enzymatic reaction of DCm with glutathione thiolate may involve stepwise breaking and making of bonds with the carbon atom of DCm,unlike the uncatalyzed reaction,which is a one-stage process,as shown by quantum-chemical modeling.

关键词： Dichloromethane(DCm) microbial degradation Aerobic methylotrophic bacteria Dichloromethane dehalogenase Carbon and chlorine isotopic fractionation

BINARY TIssUE CLAssIFICATION sTUDIEs ON REsECTED HUmAN BREAsT TIssUEs UsING OPTICAL COHERENCE TOmOGRAPHY ImAGEs

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Journal of Innovative Optical Health sciences 2011年第1期4卷 59-66页

作者： m.BHATTACHARJEE P.C.AsHOK K.DIVAKAR RAO s.K.mAJUmDER Y.VERmA P.K.GUPTA Laser Biomedical Applications and Instrumentation Division Raja Ramanna Center for Advanced Technology Indore 452013 India the Variable Energy Cyclotron Centre Kolkata(India) the school of Physics and Astronomy University of St.AndrewsSt.AndrewsScotland(UK)

We report the results of a comparative study of Fourier domain analysis(FDA)and texture analysis(TA)of optical coherence tomography(OCT)images of resected human breast tissues for binary classification between normalabnormal classes and benignmalignant *** the incorporation of Fisher linear discriminant analysis(FLDA)in TA for feature extraction,the TA-based algorithm provided improved diagnostic performance as compared to the FDAbased algorithm in discriminating OCT images corresponding to breast tissues with three different *** specificity and sensitivity values obtained for normalabnormal classification were both 100%,whereas they were 90% and 85%,respectively for benignmalignant classification.

关键词： Optical coherence tomography breast tissue texture analysis Fourier domain analysis classification

Accuracy of biometric formulae for intraocular lens power calculation in a teaching hospital

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International Journal of Ophthalmology(English edition) 2020年第1期13卷 61-65页

作者： Kevin s Tang Elaine m Tran Allison J Chen David R Rivera Jorge J Rivera Paul B Greenberg Division of Ophthalmology Alpert Medical SchoolBrown UniversityProvidence 02903Rhode IslandUSA section of Ophthalmology Providence VA Medical CenterProvidence 02908Rhode IslandUSA shiley Eye Institute and Department of Ophthalmology University of California San DiegoLa Jolla 92093CaliforniaUSA

AIm: To evaluate the accuracy of three commonly used biometric formulae across different axial lengths(ALs) at one United states Veterans Affairs teaching ***: A retrospective chart review was conducted from November 2013 to may 2018. One eye of each patient who underwent cataract surgery with a monofocal intraocular lens(IOL) was included. The range of postoperative follow-up period was from 3 wk to 4 mo. The Holladay 2, Barrett Universal II, and Hill-Radial Basis Function(Hill-RBF) formulae were used to predict the postoperative refraction for all cataract surgeries. For each formula, we calculated the prediction errors [including mean absolute prediction error(mAE)] and the percentage of eyes within ±0.25 diopter(D) and ±0.5 D of predicted refraction. We performed subgroup analyses for short(ALmm), medium(AL 22.0-25.0 mm), and long eyes(AL>25.0 mm).REsULTs: A total of 1131 patients were screened, and 909 met the inclusion criteria. Resident ophthalmologists were the primary surgeons in 710(78.1%) cases. We found no statistically significant difference in predictive accuracy among the three formulae over the entire AL range or in the short, medium, and long eye subgroups. Across the entire AL range, the Hill-RBF formula resulted in the lowest mAE(0.384 D) and the highest percentage of eyes with postoperative refraction within ±0.25 D(42.7%) and ±0.5 D(75.5%) of predicted. All three formulae had the highest mAEs(>0.5 D) and lowest percentage within ±0.5 D of predicted refraction(short ***: In cataract surgery patients at our teaching hospital, three commonly used biometric formulae demonstrate similar refractive accuracy across all ALs. short eyes pose the greatest challenge to predicting postoperative refractive error.

关键词： cataract surgery biometry intraocular lens power calculation

sounding Board. The illness as the focus of geriatric medicine

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四川生理科学杂志 2024年第1期46卷 86-86页

作者： m E Williams 不详

Understanding the difference between illness and disease is a prerequisite to the care of patients affected by incurable *** palliation in the absence of substantive information regarding this discrepancy is the art of *** elderly patients often present with several chronic diseases,many of which are irreversible,cure-oriented physicians caring for the elderly are especially vulnerable to frequent disappointments.

关键词： patients diseases irreversible

Enhancement of luminescence intensity and spectroscopic analysis of Eu^(3+) activated and Li^+ charge-compensated Bi_2O_3 nanophosphors for solid-state lighting

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Journal of Rare Earths 2019年第4期37卷 356-364页

作者： s.Ashwini s.C.Prashantha RamachANDra Naik H.Nagabhushana Department of Physics Channabasaveshwara Institute of Technology Research Center Department of Science East West Institute of Technology Department of Physics New Horizon College of Engineering CNR Rao Center for Advanced materials Tumkur University

The present work reports the synthesis, characterization, photoluminescence and photocatalytic activity of Eu^(3+)(1 mol%-11 mol%) doped and Li^+(0.5 mol%-5 mol%) co-doped Bi_2 O_3 nanophosphors(NPs) by sonochemical method. The average particle size was estimated using powder X-ray diffraction(PXRD)and transmission electron microscopy(TEm) and is found to be in the range of 30-35 nm. The scanning electron microscopy(sEm) images were highly dependent on sonication time and concentration of epigallocatechin gallate(EGCG) bio-surfactant. The energy gap of doped and co-doped Bi_2 O_3 nanophosphors was estimated using Kubelka-munk(K-m) function and is found to be in the range of2.9-3.08 eV. The effect of Li+ co-doping on luminescence of optimized Bi_2 O_3:Eu^(3+) was studied and is found about more than 3 fold enhancement of emission intensity. Judd-Ofelt parameters(Ω_2, Ω_4 and Ω_6).transition probabilities(A_T), quantum efficiency(η), luminescence lifetime(τ_(rad)), color chromaticity coordinates(CIE) and correlated color temperature(CCT) values were estimated from the emission spectra and are discussed in detail. The estimated CIE chromaticity co-ordinates are very close to the NTsC(National Television standard Committee) standard value of red emission. The synthesized NPs show excellent photocatalytic activity of acid red-88 under UV-light irradiation, which can degrade 98.1% in60 min. The decreasing electron-hole pair recombination rate with quick electron transfer ability is predominantly ascribed to the balance between crystallite size, morphology, band gap, defects, surface area, etc. These results show a light for the use of sonochemical route of Bi_2 O_3:Eu^(3+):Li^+ in solid state display and photocatalytic applications.

关键词： Bi2O3:Eu3+:Li+ sonochemical Photoluminescence CIE n CCT Photocatalysis Rare earths

Antifungal activity of Ocimum sanctum Linn.(Lamiaceae) on clinically isolated dermatophytic fungi

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Asian Pacific Journal of Tropical medicine 2011年第8期4卷 654-657页

作者： Balakumar s Rajan s Thirunalasundari T Jeeva s Department of Chemistry and Biosciences SASTRA UniversitySrinivasa Ramanujan Centre.Kumbakonam- 612001Tamil NaduIndia Department of microbiology M.R.Government Arts CollegeMannargudi.Thriuvarur District.Tamil NaduIndia Department of Biotechnology Bharathidasan UniversityTiruchirappalli-620 024Tamil Nadu.India Centre for Biodiversity and Biotechnology.Department of Botany Nesamony Memorial Christian College.Marthandam-629 165Tamil Nadu.India

Objective:To assess antifungal activity of Ocimum sanctum leaves against dermatophytic fungi. methods:Antifungal activity of Ocimum sanctum leaves was measured by 38 A NCCLs method. minimum inhibitory concentration(mIC) and minimum fungicidal concentration(mFC) of various extracts and fractions of Ocimum sanctum leaves were also ***:Ocimum sanctum leaves possessed antifungal activity against clinically isolated dermatophytes at the concentration of 200μg/*** and mFC were high with water fraction(200μg/mL) against dermatophytic fungi ***:Ocimum sanctum has antifungal activity,and the leaf extracts may be a useful source for dermatophytic infections.

关键词： Antifungal activity Dermatophytosis Epidermophyton floccosum minimum fungicidal concentration microsporum sp minimum inhibitory concentration Ocimum sanctum Trichophyton sp

measurement of neutron cross sections and resonance parameters of ^(169)Tm below 100 eV

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Chinese Physics C 2010年第2期34卷 177-181页

作者：王文明李霞赵志祥周祖英于洪伟吴海成魏义祥 T.F. Wang G.N. Kim m.W. Lee K.s. Kim m.H. Cho I.s. Ko W. Namkung China Institute of Atomic Energy Department of Engineering Physics Tsinghua University Department of Physics Kyungpook National University Department of Physics Pohang University of Science and Technology

The neutron total cross-sections of thulium （^169Tm） were measured in the neutron energy region from 0.01 eV to 100 eV by using the time-of-flight method at the Pohang Neutron Facility, which consists of an electron linac, a water-cooled tantalum target with a water moderator, and a 12 m time of flight path, Two thulium plates with different thicknesses were used for the neutron transmission measurement. The background level was determined by using a notch-filter of Co, In, and Cd sheets. The present measurement was compared with the previous ones, and a new set of resonance parameters of ^169Tm isotope was obtained from the transmission rate by using the sAmmY code, with a comparison with the recommended parameters by mughabghab.

关键词： resonance parameters thulium n-TOF method sAmmY