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A novel indicator system for catalytic spectrophotometric determination and speciation of inorganic selenium species (Se(Ⅳ), Se(Ⅵ)) at trace levels in natural lake and river water samples

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Rare Metals 2011年第5期30卷 477-487页

作者： Ramazan Gürkan Halil brahim Ulusoy Mehmet akay Pinar Bulut Department of Chemistry Faculty of Science University of Cumhuriyet

A novel catalytic kinetic method is proposed for the determination of Se（Ⅳ）, Se（Ⅵ）, and total inorganic selenium in water based on the catalytic effect of Se（Ⅳ） on the reduction of Celestine blue by sodium sulfide at pH 7.0 phosphate buffer. The fixed-time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the two calibration graphs are linear with a good correlation coefficient in the range 2-20 and 20-200 μg·L-1 of Se（Ⅳ） for the fixed-time method at 30℃. The experimental and theo- retical detection limits of the developed kinetic method were found to be 0.21 and 2.50 μg·L-1 for the fixed-time method （3 min）. All of the variables that affect the sensitivity at 645 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se（Ⅳ） determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus as long as chelating agents of thiourea and thiosulphate. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The relative standard deviations （RSDs） for ten replicate measurements of 2, 10, and 20 μg·L-1 of Se（Ⅳ） change between 0.35% and 5.58%, while the RSDs for ten replicate measurements of 3, 6, and 12 μg·L-1 of Se（Ⅵ） change between 0.49% and 1.61%. Analyses of a certified standard reference material （NIST SRM 1643e） for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. The Se（Ⅳ）, Se（Ⅵ）, and total inorganic selenium in lake and river water samples have been successfully determined by this method after selective reduction of Se（Ⅵ） to Se（Ⅳ）.

关键词： selenium speciation Celestine blue catalytic effect kinetic spectrophotometry natural waters

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Giant magnetocaloric effect in the Gd_5 Ge_(2.025)Si_(1.925)In_(0.05) compound

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Chinese Physics B 2010年第3期19卷 517-522页

作者： E.Yzak I.Dincer Y.Elerman Department of Engineering Physics Faculty of EngineeringAnkara University06100 BesevlerAnkaraTurkey

The magnetocaloric properties of the GdsGe2.025Si1.925In0.05 compound have been studied by x-ray diffraction, magnetic and heat capacity measurements. Powder x-ray diffraction measurement shows that the compound has a dominant phase of monoclinic Cd5Ge2Si2-type structure and a small quantity of Gds（Ge,Si）3-type phase at room temperature. At about 270 K, this compound shows a first order phase transition. The isothermal magnetic entropy change （△SM） is calculated from the temperature and magnetic field dependences of the magnetization and the temperature dependence of MCE in terms of adiabatic temperature change （△Tad） is calculated from the isothermal magnetic entropy change and the temperature variation in zero-field heat-capacity data. The maximum △SM is -13.6 J·kg^-1.K^- 1 and maximum ATad is 13 K for the magnetic field change of 0 5 T. The Debye temperature （θD） of this compound is 149 K and the value of DOS at the Fermi level is 1.6 states/*** from the low temperature zero-field heat-capacity data. A considerable isothermal magnetic entropy change and adiabatic temperature change under a field change of 0-5 T jointly make the Gd5Ge2.025Si1.925In0.05 compound an attractive candidate for a magnetic refrigerant.

关键词： magnetic properties magnetocaloric effect isothermal magnetic entropy change adia-batic temperature change

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First record of Capnodium berberidis from India

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Studies in Fungi 2019年第1期4卷 37-42页

作者： Gautam ak Avasthi S School of Agriculture Faculty of ScienceAbhilashi UniversityMandi-175028India Department of Botany Abhilashi Post Graduate Institute of SciencesMandi-175008India

Capnodium berberidis,a sooty mould fungus,previously reported only from Pakistan in 1978,was recently observed on Berberis lycium in Jot Pass,district Chamba of Himachal Pradesh,*** lycium is a well-known small to medium sized spiny,woody,deciduous or evergreen medicinal and ornamental plant distributed throughout temperate and subtropical regions of the *** symptoms appeared as thin,black to dark brown,easily removed superficial layer of hyphae on various parts of host plant including leaves,stem,twigs and *** detailed studies on its morphology and taxonomy revealed it a sooty mould fungus Capnodium *** per literature consulted,this is the first report of Capnodium berberidis from India and probably second from world.

关键词： Berberis lycium black mildew Dothideomycetes Himachal Pradesh new record sooty moulds

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Assessment of germ cell apoptosis in cryptorchid rats

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Asian Journal of Andrology 2002年第3期4卷 183-186页

作者： IzzetKoak MehmetDündar Mine Hekimgil Pinar Okyay Department of Urology Adnan Menderes University School of Medicine Aydin TurkeyDepartment of Urology Adnan Menderes University School of Medicine Aydin TurkeyDepartment of Pathology Ege University School of Medicine Izmir TurkeyDepartment of Public Health Adnan Menderes University School of Medicine Aydin Turkey

Aim: To investigate the relationship between germ cell degeneration and apoptosis in cryptorchid rats. Methods: Thirteen 21-day-old Wistar rats were made unilaterally cryptorchid by closing the left inguinal canal. At day 30 (Group 1, n=6) and day 60 (Group 2, n=7) after operation, the testes were removed for histopathological examination. The controls (n=8) were sham operated and were sacrificed at day 60. Germ cell apoptosis was assessed by means of the TUNEL method. Results: Spermatogenesis was arrested and the testicular and seminiferous tubular diameters were significantly reduced In the unilateral undescended testes (UUTs) compared with the contralateral descended testes (CDTs) and the control rats. However, atrophic changes, pathological calcification, necrosis of seminiferous tubule, and absence or sloughing of germ cells were not found in all the animals. The spermatocytes were the main type of germ cells undergoing apoptosis in all the groups. In the UUTs, there was a significant and time-dependent increase in the mean apoptotic index. By 60 days after surgery, increased apoptosis in germ cells was also observed in the CDTs. Conclusion: Apoptosis is the predominant mechanism of germ cell death rather than atrophy and necrosis in cryptorchidism.

关键词： cryptorchidism germ cells apoptosis TUNEL method

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Preliminary pharmacological evaluation of Martynia annua Linn leaves for wound healing

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Asian Pacific Journal of Tropical Biomedicine 2011年第6期1卷 421-427页

作者： Santram Lodhi Singhai ak Department of Pharmaceutical Sciences Dr.H.S.Gour University SAGAR(M.P.)

Objective:To evaluate the wound healing potential of fractions from ethanol extract of Martynin annua(***) Linn ***:Ethanol extract of *** Linn leaves was fractionate into three different fractions(MAF-A,MAF-B and MAF-C) which were screened for wound healing potential using two models:excision and incision on *** thin layer chromatography(TLC) profile of all fractions were analysed and TLC of luteolin was also *** PovidoneIodine Ointment was used as reference for *** and incision wounds were created on dorsal portion of rats for *** contraction,biochemical parameters(protein level and hydroxyproline level) and histopathological study were performed in excision wound model whereas incision model was used for determination of tensile ***:The wound contraction and tensile strength of skin tissues were observed significantly greater in MAF-C fraction treated group than other two fractions(Plagen fibres and fibroblast cells as compared with the control ***:In conclusion, our findings suggest that fiaction MAF-C from ethanol extract of *** leaves is found most effective in wound healing.

关键词： Martynia annua Wound healing Povidone-iodine ointment Incision Excision Luteolin TLC Wound contraction Tensile strength

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Production and characterization of ZnO nanoparticles and porous particles by ultrasonic spray pyrolysis using a zinc nitrate precursor

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International Journal of Minerals,Metallurgy and Materials 2012年第7期19卷 651-656页

作者： Burak Ebin Elif Arτg Burak zkal Sebahattin Gürmen Metallurgical & Materials Engineering Department Istanbul Technical University

ZnO nanoparticles and porous particles were produced by an ultrasonic spray pyrolysis method using a zinc nitrate precursor at various temperatures under air atmosphere. The effects of reaction temperature on the size and morphology of ZnO particles were investi- gated. The samples were characterized by energy dispersive spectroscopy, X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. ZnO particles were obtained in a hexagonal crystal structure and the crystallite shapes changed from spherical to hex- agonal by elevating the reaction temperature. The crystallite size grew by increasing the temperature, in spite of reducing the residence time in the heated zone. ZnO nanoparticles were obtained at the lowest reaction temperature and ZnO porous particles, formed by aggregation of ZnO nanoparticles due to effective sintering, were prepared at higher temperatures. The results showed that the properties of ZnO particles can be controlled by changing the reaction temperature in the ultrasonic spray pyrolysis method.

关键词： zinc oxide nanoparticles nanocrystallites porous materials ultrasonic applications spray pyrolysis

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New insights into the coagulopathy of liver disease and liver transplantation

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World Journal of Gastroenterology 2006年第48期12卷 7725-7736页

作者： M Senzolo P Burra E Cholongitas ak Burroughs Gastroenterology Department of Surgical and Gastroenterological Sciences University Hospital of Padua Padua ItalyLiver Transplantation and Hepatobiliary Unit Royal Free Hospital London United Kingdom Gastroenterology Department of Surgical and Gastroenterological Sciences University Hospital of Padua Padua Italy Liver Transplantation and Hepatobiliary Unit Royal Free Hospital London United Kingdom

The liver is an essential player in the pathway of coagulation in both primary and secondary haernostasis. Only yon Willebrand factor is not synthetised by the liver, thus liver failure is associated with impairment of coagulation. However, recently it has been shown that the delicate balance between pro and antithrornbotic factors synthetised by the liver might be reset to a lower level in patients with chronic liver disease. Therefore, these patients might not be really anticoagulated in stable condition and bleeding may be caused only when additional factors, such as infections, supervene. Portal hypertension plays an important role in coagulopathy in liver disease, reducing the number of circulating platelets, but platelet function and secretion of thrornbopoietin have been also shown to be impaired in patients with liver disease. Vitamin K deficiency may coexist, so that abnormal clotting factors are produced due to lack of gamma carboxylation. Moreover during liver failure, there is a reduced capacity to clear activated haernostatic proteins and protein inhibitor complexes from the circulation. Usually therapy for coagulation disorders in liver disease is needed only during bleeding or before invasive procedures. When end stage liver disease occurs, liver transplantation is the only treatment available, which can restore normal haemostasis, and correct genetic clotting defects, such as haemophilia or factor V Leiden mutation. During liver transplantation haemorrage may occur due to the pre-existing hypocoagulable state, the collateral circulation caused by portal hypertension and increased fibrinolysis which occurs during this surgery.

关键词： Coagulation Cirrhosis Liver transplantation

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Magnetocaloric properties of the Gd_5Si_(2.05-x)Ge_(1.95-x)Mn_(2x) compounds

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Journal of Rare Earths 2010年第3期28卷 477-480页

作者： E.Yüzüak I.Dincer Y.Elerman Ankara University Faculty of EngineeringDepartment of Engineering Physics

The influence of the manganese-alloying on the structure and magnetocaloric properties of the Gd5Si2.05Ge1.95 compound was studied by X-ray powder diffraction and magnetization *** Gd5Si2.05-xGe1.95-xMn2x(2x=0,0.03 and 0.08) compounds crystallized in the Gd5Si2Ge2-type monoclinic *** all X-ray powder diffraction patterns,a minor hexagonal Gd5Si3 phase was observed as a second *** increasing Mn content,the unit cell volume *** the compounds with x=0,0.03 and 0.08,the fi...

关键词： magnetic materials heat treatments intermetallics rare earths

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Effects of manganese doping on magnetocaloric effect in Ge-rich Gd_5Ge_(2.05)Si_(1.95) alloy

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Journal of Rare Earths 2012年第3期30卷 217-221页

作者： E.Yüzüak I.Dincer Y.Elerman Department of Engineering Physics Faculty of EngineeringAnkara University

The structure, magnetic and magnetocaloric properties of the Ge-rich Gd5Ge2.05-xSi1.95-xMn2x （x=0.01 and 0.03） alloys were investigated by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimeter （DSC） and magnetization measurements. The results of energy dispersive X-ray analysis （EDX） and X-ray diffraction analyses showed that the composition and crystal structure of the alloys were desired. DSC measurements were performed to determine the transformation temperatures for each alloy. Both alloys exhibited the first order phase transition around room temperature. The alloys showed an anti-ferromagnetic transition around 60 K. The isothermal magnetic entropy changes of the alloys were determined from the isothermal magnetization measurements by using the Maxwell relation. The maximum values of isothermal magnetic entropy change of the Gd5Ge2.05-xSi1.95-xMn2x alloy with x=0.01 was found to be -12.1 and -19.8 J/（kg·K） using Maxwell equation around 268 K in applied fields of 2 and 5 T, respectively.

关键词： magnetocaloric effect entropy change magnetic materials rare earths

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Healing property of the Piper betel phenol, allylpyrocatechol against indomethacin-induced stomach ulceration and mechanism of action

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World Journal of Gastroenterology 2007年第27期13卷 3705-3713页

作者： S Bhattacharya D Banerjee ak Bauri S Chattopadhyay SK Bandyopadhyay Department of Biochemistry Dr. B.C. Roy Post Graduate Institute of Basic Medical Sciences IPGME&R 244B Acharya Jagadish Chandra Bose Road Kolkata-700020 India Bio-Organic Division Bhabha Atomic Research Centre Mumbai-400085 India

AIM：To evaluate the protective activity of allylpyrocatechol （APC）, the major antioxidant constituent of Piper betel, against the indomethacin-induced stomach ulceration in the rat model and correlates with its antioxidative and mucin protecting properties.METHODS： Male Sprague-Dawley rats were divided into five groups. Normal control rats （group Ⅰ ） were given the vehicle oral dose of gum acacia in distilled water （1 mL per rat）; ulcerated control and treated rats （groups Ⅱ-V） were given a single dose of indomethacin （30 mg/kg body wt.）; group Ⅱ rats were sacrificed 4 h after indomethacin administration; groups Ⅲ-Ⅴ rats were given the vehicle （1 mL per rat） or APC （2 mg/kg body wt.） or misoprostol （1.43 μg/kg body wt.） once daily by oral intubation for 7 d starting from 4 h after the indomethacin administration. After 7 d, the stomach tissues were excised for histological examination and biochemical analysis. RESULTS： Treatment with APC （2 mg/kg body wt per day） and misoprostol （1.43 μg/kg body wt per day） for 7 d could effectively heal the stomach ulceration as revealed from the ulcer index and histopathological studies. Compared to the zero day ulcerated group, treatment with APC and misoprostol reduced the ulcer index by 93.4% and 85.4% respectively （P 〈 0.05）. Both APC and misoprostol accelerated ulcer healing observed in natural recovery （P 〈 0.05）, their respective healing capacities not being significantly different. The healing capacities of APC and misoprostol could be attributed to their antioxidant activity as well as the ability to enhance the rnucin content of the gastric tissues. Compared to the ulcerated untreated rats, those treated with APC and rnisoprostol showed near normal MDA levels, while the protein levels were 86% and 78% of the normal value respectively （P 〈 0.05）. Likewise, both APC and rnisoprostol increased the SOD, catalase, and rnucin levels significantly （P 〈 0.05）, the effect of APC being better. CONCLUSION： APC can protect ind

关键词： Allylpyrocatechol Antioxidant Histopathology Indornethacin Mucin Piper betel Stomach ulcer

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