Despite the safety,low cost,and high theoretical capacity(820 mA h g^(-1))of Zn metal anodes,the practical application of aqueous Zn metal batteries remains a critical challenge due to the Zn dendrite growth,corrosion...Despite the safety,low cost,and high theoretical capacity(820 mA h g^(-1))of Zn metal anodes,the practical application of aqueous Zn metal batteries remains a critical challenge due to the Zn dendrite growth,corrosion,and hydrogen evolution reaction.Herein,we demonstrate the MXene ink hosting Zn metal anodes(MX@Zn)for high-performance and patternable Zn metal full batteries.The as-designed MX@Zn electrode is more facile and reversible than bare Zn and CC@Zn,as verified by better cyclic stability and lower overpotentials of symmetric cells with the plating capacity of 0.05 mA h cm^(-2)at 0.1 m A cm^(-2)and of 1 m A h cm^(-2)at 1 m A cm^(-2).The MX@Zn|MnO_(2)full cells deliver a high specific capacity of 281.9 m A h g^(-1),91.5%of the theoretical capacity,achieving 50%capacity retention from 60 mA g^(-1)to 300 mA g^(-1)and 79.7%of initial capacity after 200 cycles.Moreover,the patterned devices based on the MX@Zn electrode achieve high energy and power densities of 348.57 Wh kg^(-1)and 1556 W kg^(-1),respectively,along with a capacity retention of 64%and Coulombic efficiency of 99%over 500 cycles.The high performance of MX@Zn is attributed to the high electrical conductivity and hydrophilicity of MXene and rapid ion diffusion through the 3D interconnected porous channels.展开更多
Nickel and nickel-ceria catalysts supported on high surface area silica, with 6 wt% Ni and 20 wt% CeO2 were prepared by microwave assisted(co) precipitation method. The catalysts were investigated by XRD,TPR and XPS a...Nickel and nickel-ceria catalysts supported on high surface area silica, with 6 wt% Ni and 20 wt% CeO2 were prepared by microwave assisted(co) precipitation method. The catalysts were investigated by XRD,TPR and XPS analyses and they were tested in partial oxidation of methane(CPO). The catalytic reaction was carried out at atmospheric pressure in a temperature range of 400–800℃ with a feed gas mixture containing methane and oxygen in a molecular ratio CH4/O2=2. The Ni catalyst exhibited 60% methane conversion with 60% selectivity to CO already at 500℃. On the contrary, the Ni–Ce catalyst was inert to CPO up to 700℃. Moreover, the former catalyst reproduced its activity at the descending temperatures maintaining a good stability at 600℃, over a reaction time of 80 h, whereas the latter one completely deactivated. Test of CH4 temperature programmed surface reaction(CH4-TPSR) revealed a higher methane activation temperature(> 100℃) for the Ni–Ce catalyst as compared to the Ni one. Noticeable improvement of the ceria containing catalyst occurred when the reaction test started at a temperature higher than the methane decomposition temperature. In this case, the sample achieved the same catalytic behavior of the Ni catalyst. As confirmed by XPS analyses, the distinct electronic state of the supported nickel was responsible for the differences in catalytic behavior.展开更多
ZnO,NiO and ZnO@NiO nanocrystals were successfully synthesized and characterized by FTIR,XRD and SEM methods.The average particles sizes of ZnO,NiO and ZnO@NiO were32,50and48nm,respectively.The nanocrystals were exami...ZnO,NiO and ZnO@NiO nanocrystals were successfully synthesized and characterized by FTIR,XRD and SEM methods.The average particles sizes of ZnO,NiO and ZnO@NiO were32,50and48nm,respectively.The nanocrystals were examined assensors for cyanide removal.The cyanide sensing test revealed that,compared with the pure ZnO,NiO,the ZnO@NiO nanocrystalsexhibited highly improved sensing performances.The ZnO@NiO nano crystals were found to have better capacity for iron cyanidethan sodium cyanide.The effects of significant parameters such as contact time,pH(2-12),nanocrystal dose(0.02-0.4g)andcyanide concentration(5-50mg/L)on the removal of cyanide by nanocrystals were explored.At an optimum pH<5,over90%removal of20mg/L cyanide was obtained for nanocrystal dose of0.2g after30min contact time for iron cyanide by ZnO@NiOnano crystals.Cyanide removal was followed by pseudo second order kinetic model for ZnO@NiO nano crystals(k2=4.66×10-2andR2=0.999).The values of standard entralpy change of7.87kJ/mol and standard free energy change of-18.62kJ/mol at298K suggestthe adsorption of cyanide on nanocrystals is an endothermic and spontaneous process.ZnO@NiO nanocrystal is an efficient sensorfor removal of cyanide from water and wastewater.展开更多
AIM：To evaluate possible risk factors for the spread of hepatitis C infection and to analyze the characteristics of the epidemiological and clinical patterns among the patients with hepatitis C infection. METHODS： D...AIM：To evaluate possible risk factors for the spread of hepatitis C infection and to analyze the characteristics of the epidemiological and clinical patterns among the patients with hepatitis C infection. METHODS： During a five-year period a cross-sectional study was conducted among HCV positive individuals referred to the Ahwaz JundiShapour University Hospitals （AJSUH） and Hepatitis Clinic from 1 Sept 1999 to 1 Sept 2003. The control group consisted of first time blood donors referred to the Regional Blood Transfusion organization. Enzyme-linked immunosorbent assay and recombinant immunoblot assay anti-hepatitis C virus （HCV） tests were performed for two groups. Positive serum specimens were retested using polymerase chain reaction （PCR） for HCV RNA. Risk factors were evaluated using a questionnaire. Reported risk factors among infected subjects （＂HCV-positive＂） were compared to those of subjects never exposed （＂HCV-negative＂） to HCV. RESULTS： A total of 514 subjects were studied for HCV, of which 254 were HCV-positive and 260 HCV- negative donors comprised the control group. Mean age of the patients was 28.4 （Std 15.22） years. HCV-positive subjects were more likely to be of male gender （63% versus 37%）. Transfusion 132 （52%）, non-intravenous （n-iv） drug abuse and iv drug abuse 37 （14.5%）, haemodialysis 25 （10%）, receiving wounds at war and extramarital sexual activities （2.4%）, tattooing （3.6%） were found to be independent risk factors of being HCV-positive. No apparent risk factors could be demonstrated in 29 （11.2%） of the positive cases. CONCLUSION： Our data indicate that a history of transfusion and iv drug abuse and haemodialysis are important risk factors for HCV infection in our area and that more careful pretransfusion screening of blood for anti- HCV must be introduced in our blood banks. Improvements in certain lifestyle patterns, and customs in this area may be essential to prevent transmission of the infection.展开更多
AIM： Celiac disease is characterized by life-long gluten intolerance. Clinical features of patients with celiac disease are variable. Studies about the prevalence of celiac disease in our country are scarce and there...AIM： Celiac disease is characterized by life-long gluten intolerance. Clinical features of patients with celiac disease are variable. Studies about the prevalence of celiac disease in our country are scarce and there is no study on the prevalence of celiac disease in southern Iran. In the current study, clinical, laboratory and histological features of 52 patients with celiac disease were evaluated. METHODS： In a cross sectional study we retrospectively studied the characteristics of 52 celiac patients at Ahwaz JundiShapour University Hospitals （AJSUH） from November 1, 1999 to 1st Sep 2004. Intestinal biopsy and serum antigliadin and anti-endomysium antibodies were used for the diagnosis of patients. Mucosal lesions were classified according to the criteria of Marsh. Antigliadin antibodies were measured with a commercial enzyme-linked immunosorbent assay. Anti-endomysium antibodies were analyzed by indirect immunofluorescence with the use of a section of monkey esophagus. Routine hematological and biochemical analyses and measurement of immunoglobulin levels were undertaken.RESULTS： Male： female ratio was 1.08. The mean ＋ SD patient age was 21 ＋ 4.5 years （range 10-70 years） and the most common symptoms were diarrhea and weight loss （78.8%） followed by fatigue （73.1%）, pallor （65.4%）, anorexia （40.4%）, abdominal distention （32.7%）, and failure to thrive （23.1%）. Diarrhea and weight loss and fatigue were the most common findings. Iron deficiency anemia was found in 63.2% of patients and this became normal after adoption of a gluten-free diet in all patients. Immunoglobulin A, IgG antigliadin antibodies and IgA anti-endomysium antibodies were found in 33 and 48 cases, 78.8% and 85.4% of patients, respectively. Biopsy of the small intestine revealed that 90.4% of patients had typical lesions according to the Marsh classification. CONCLUSION： Although classical presentation was seen in most of the patients, atypical clinical manifestations of celiac disease should be kept展开更多
Objective： To analyze the effects of a Qigong program on various parameters of unstimulated saliva, including volume, pH and secretory immunoglobulin A （S-IgA） level. Methods： Twice a day from the beginning of Fal...Objective： To analyze the effects of a Qigong program on various parameters of unstimulated saliva, including volume, pH and secretory immunoglobulin A （S-IgA） level. Methods： Twice a day from the beginning of Fall 2005, twenty-three healthy volunteers aged 22-24 did special Qigong exercises and massage of acupuncture points which stimulated the energy cycle and increased body water energy. The unstimulated saliva volume and pH were recorded every week in Spring （April, May, June） 2005 before the volunteers started to learn and exercise Qigong, and after Qigong intervention in Spring （April, May, June） 2006. During the period of study, saliva was collected in the same location and on similar dates at the Dental Faculty of Tehran University of Medical Sciences. The S-IgA levels of the last samples of the last week of Spring 2005 and 2006 were measured. Results： The unstimulated saliva volume after Qigong exercises （2.94±0.20 mL/5min） was significantly higher as compared to the pre-Qigong phase （1.65±0.102 mL/5min, P〈0.05）. The S-IgA level was 105.45±69.41 mg/mL before doing Qigong exercises, and 156.23±88.56 mg/mL after doing Qigong exercises, and a statistically significant difference was seen between the two measurements （P=0.005）. The change in pH was not statistically significant. Conclusions： The application of Qigong is beneficial for increasing salivary volume and other parameters. Moreover, the results suggest that Qigong may be a useful medication for patients with salivary hyposecretion. Further research is recommended in examining the long-term effects of Qigong on improving salivary volume and other parameters in individuals with salivary hyposecretion.展开更多
The structural and magnetic properties of the synthesized pure and functionalized CoFe2O4magnetic nanoparticles(NPs) are studied by analyzing the results from the x-ray diffraction(XRD), transmission electron microsco...The structural and magnetic properties of the synthesized pure and functionalized CoFe2O4magnetic nanoparticles(NPs) are studied by analyzing the results from the x-ray diffraction(XRD), transmission electron microscopy(TEM), FT–IR spectroscopy, thermogravimetry(TG), and vibrating sample magnetometer(VSM). To extract the structure and lattice parameters from the XRD analysis results, we first apply the pseudo-Voigt model function to the experimental data obtained from XRD analysis and then the Rietveld algorithm is used in order to optimize the model function to estimate the true intensity values. Our simulated intensities are in good agreement with the experimental peaks, therefore, all structural parameters such as crystallite size and lattice constant are achieved through this simulation. Magnetic analysis reveals that the synthesized functionalized NPs have a saturation magnetization almost equal to that of pure nanoparticles(PNPs). It is also found that the presence of the turmeric causes a small reduction in coercivity of the functionalized NPs in comparison with PNP. Our TGA and FTIR results show that the turmeric is bonded very well to the surface of the NPs. So it can be inferred that a nancomposite(NC) powder of turmeric and nanoparticles is produced. As an application, the anti-arsenic characteristic of turmeric makes the synthesized functionalized NPs or NC powder a good candidate for arsenic removal from polluted industrial waste water.展开更多
In this paper, we have investigated the prospects of exploiting the rich world thorium reserves using Canada Deuterium Uranium （CANDU） reactors. The analysis is performed using the Monte Carlo MCNP code in order to ...In this paper, we have investigated the prospects of exploiting the rich world thorium reserves using Canada Deuterium Uranium （CANDU） reactors. The analysis is performed using the Monte Carlo MCNP code in order to understand how much time the reactor is in criticality conduction. Four different fuel compositions have been selected for analysis. We have obtained the infinite multiplication factor, k∞, under full power operation of the reactor over 8 years. The neutronic flux distribution in the full core reactor has already been investigated.展开更多
In this study, we investigate the photoluminescence （PL） properties of γ and θ-alumina nanoparticles synthesized by the chemical wet method followed by annealing. The obtained experimental results indicate the pre...In this study, we investigate the photoluminescence （PL） properties of γ and θ-alumina nanoparticles synthesized by the chemical wet method followed by annealing. The obtained experimental results indicate the presence of some favorable near ultraviolet （NUV）-orange luminescent centers for usage in various luminescence applications, such as oxygen vacancies （F, F＋, F2＋, and F2 centers）, OH related defects, cation interstitial centers, and some new luminescence bands attributed to trapped-hole centers or donor-acceptor centers. The energy states of each defect are discussed in detail. The defects mentioned could alter the electronic structure by producing some energy states in the band gap that result in the optical absorption in the middle ultraviolet （MUV） region. Spectra show that photoionazation of F and F2 centers plays a crucial role in providing either free electrons for the conduction band, or the photoconversions of aggregated oxygen va- cancies into each other, or mobile electrons for electrons-holes recombination process by the Shockley-Read-Hall （SRH） mechanism.展开更多
The extrusion process of hybrid sheet metals through arbitrarily curved dies was analyzed by the method of upper bound. The material under deformation was divided into two deformation regions, bimetal and mono-metal r...The extrusion process of hybrid sheet metals through arbitrarily curved dies was analyzed by the method of upper bound. The material under deformation was divided into two deformation regions, bimetal and mono-metal regions, and the flow of the material in each region was assumed as plane strain state. The internal, shearing and frictional power terms were derived and they were used in the upper bound model. The extrusion forces for two types of die shapes, an optimum wedge shaped die and an optimum streamlined die shape for a hybrid sheet composed of copper as sleeve and aluminum as core were determined. The corresponding results for those two die shapes were also determined by using the finite element code, ABAQUS, and compared with the upper bound results. These comparisons show a good agreement.展开更多
Nearly 8.5 million people in Iran directly or indirectly make a living from hand-made carpet weaving industry. Ongoing work, poor postures, breathing problems and skin irritations are among factors affecting the healt...Nearly 8.5 million people in Iran directly or indirectly make a living from hand-made carpet weaving industry. Ongoing work, poor postures, breathing problems and skin irritations are among factors affecting the health, safety and wellbeing of those involved in this industry. Hence, considering such factors seem to improve the quality of carpet as a valuable cultural commodity and expand its export. Accordingly, this study investigates the oxidative stress biomarkers among involved and non-involved people in the hand-made carpet industry. 25 carpet maker and 25 ordinary people (not involved in carpet industry) who had been matched for age and sex were selected as study groups. The level of oxidative stress biomarkers such as antioxidant capacity, total thiols and catalase were measured among subjects, and finally the biomarkers were compared between the two groups. To compare the oxidative stress biomarkers in two groups, Independent Sample T Test was used. The mean levels of total antioxidant capacity showed no significant difference between the two groups (0.05 p-value). In conclusion, carpet weaving industry induces oxidative stress and natural antioxidant may be considered beneficial for the protection of oxidative damage in such subjects.展开更多
We report combination of explants and enzymatic protocol as mixed enzymatic-explant procedure to faster extraction of MSCs from WJ. Umbilical cords (UC) were collected from Imam Khomini Hospital. For explant outgrowth...We report combination of explants and enzymatic protocol as mixed enzymatic-explant procedure to faster extraction of MSCs from WJ. Umbilical cords (UC) were collected from Imam Khomini Hospital. For explant outgrowth, 6 - 9 pieces of WJ were transferred onto tissue culture flask and waited for attachment. For mixed enzymatic-explant, 1 cm3 pieces WJ were placed in enzymatic cocktail comprising 4 mg/ml Collagenase Type I and 1 mg/ml Hyaluronidase and 0.1% trypsin-EDTA. Then isolated cells were analyzed for surface cell markers such as CD73, CD31. Isolated 1.0 × 106 MSCs/ml were encapsulated in alginate hydrogel. Cells with MSCs phenotype were isolated from mixed enzymatic-explant and explant procedures within 24 - 48 hrs and 7 - 10 days, respectively. Both of procedures were shown to form clumps and colonies with dense centers. Phenotypic changes gradually appeared as round cell in UC pieces into homogeneous spindle-shaped and typical fibroblast-like shape cells. By using flow cytometery MSCs showed positive for CD73, and negative for CD31. the morphology of viable MSCs in the beads did not significantly show a different morphology pattern before and after the bead formation process. These findings are indicated that when mixed enzymatic-explant procedure is performed MSCs can be isolated faster and much higher from WJ. These finding is important in comparing with time consuming explants culture for isolation of MSCs.展开更多
基金supported by financial support from the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(NRF-2020R1A3B2079803 and NRF2019K1A3A1A21032033),Republic of Korea。
文摘Despite the safety,low cost,and high theoretical capacity(820 mA h g^(-1))of Zn metal anodes,the practical application of aqueous Zn metal batteries remains a critical challenge due to the Zn dendrite growth,corrosion,and hydrogen evolution reaction.Herein,we demonstrate the MXene ink hosting Zn metal anodes(MX@Zn)for high-performance and patternable Zn metal full batteries.The as-designed MX@Zn electrode is more facile and reversible than bare Zn and CC@Zn,as verified by better cyclic stability and lower overpotentials of symmetric cells with the plating capacity of 0.05 mA h cm^(-2)at 0.1 m A cm^(-2)and of 1 m A h cm^(-2)at 1 m A cm^(-2).The MX@Zn|MnO_(2)full cells deliver a high specific capacity of 281.9 m A h g^(-1),91.5%of the theoretical capacity,achieving 50%capacity retention from 60 mA g^(-1)to 300 mA g^(-1)and 79.7%of initial capacity after 200 cycles.Moreover,the patterned devices based on the MX@Zn electrode achieve high energy and power densities of 348.57 Wh kg^(-1)and 1556 W kg^(-1),respectively,along with a capacity retention of 64%and Coulombic efficiency of 99%over 500 cycles.The high performance of MX@Zn is attributed to the high electrical conductivity and hydrophilicity of MXene and rapid ion diffusion through the 3D interconnected porous channels.
基金The Executive Programme for Cooperation between Italy and India (Prot.No.MAE01054762017)。
文摘Nickel and nickel-ceria catalysts supported on high surface area silica, with 6 wt% Ni and 20 wt% CeO2 were prepared by microwave assisted(co) precipitation method. The catalysts were investigated by XRD,TPR and XPS analyses and they were tested in partial oxidation of methane(CPO). The catalytic reaction was carried out at atmospheric pressure in a temperature range of 400–800℃ with a feed gas mixture containing methane and oxygen in a molecular ratio CH4/O2=2. The Ni catalyst exhibited 60% methane conversion with 60% selectivity to CO already at 500℃. On the contrary, the Ni–Ce catalyst was inert to CPO up to 700℃. Moreover, the former catalyst reproduced its activity at the descending temperatures maintaining a good stability at 600℃, over a reaction time of 80 h, whereas the latter one completely deactivated. Test of CH4 temperature programmed surface reaction(CH4-TPSR) revealed a higher methane activation temperature(> 100℃) for the Ni–Ce catalyst as compared to the Ni one. Noticeable improvement of the ceria containing catalyst occurred when the reaction test started at a temperature higher than the methane decomposition temperature. In this case, the sample achieved the same catalytic behavior of the Ni catalyst. As confirmed by XPS analyses, the distinct electronic state of the supported nickel was responsible for the differences in catalytic behavior.
基金financial support from the Research Council of Islamic Azad University of Yazd
文摘ZnO,NiO and ZnO@NiO nanocrystals were successfully synthesized and characterized by FTIR,XRD and SEM methods.The average particles sizes of ZnO,NiO and ZnO@NiO were32,50and48nm,respectively.The nanocrystals were examined assensors for cyanide removal.The cyanide sensing test revealed that,compared with the pure ZnO,NiO,the ZnO@NiO nanocrystalsexhibited highly improved sensing performances.The ZnO@NiO nano crystals were found to have better capacity for iron cyanidethan sodium cyanide.The effects of significant parameters such as contact time,pH(2-12),nanocrystal dose(0.02-0.4g)andcyanide concentration(5-50mg/L)on the removal of cyanide by nanocrystals were explored.At an optimum pH<5,over90%removal of20mg/L cyanide was obtained for nanocrystal dose of0.2g after30min contact time for iron cyanide by ZnO@NiOnano crystals.Cyanide removal was followed by pseudo second order kinetic model for ZnO@NiO nano crystals(k2=4.66×10-2andR2=0.999).The values of standard entralpy change of7.87kJ/mol and standard free energy change of-18.62kJ/mol at298K suggestthe adsorption of cyanide on nanocrystals is an endothermic and spontaneous process.ZnO@NiO nanocrystal is an efficient sensorfor removal of cyanide from water and wastewater.
文摘AIM：To evaluate possible risk factors for the spread of hepatitis C infection and to analyze the characteristics of the epidemiological and clinical patterns among the patients with hepatitis C infection. METHODS： During a five-year period a cross-sectional study was conducted among HCV positive individuals referred to the Ahwaz JundiShapour University Hospitals （AJSUH） and Hepatitis Clinic from 1 Sept 1999 to 1 Sept 2003. The control group consisted of first time blood donors referred to the Regional Blood Transfusion organization. Enzyme-linked immunosorbent assay and recombinant immunoblot assay anti-hepatitis C virus （HCV） tests were performed for two groups. Positive serum specimens were retested using polymerase chain reaction （PCR） for HCV RNA. Risk factors were evaluated using a questionnaire. Reported risk factors among infected subjects （＂HCV-positive＂） were compared to those of subjects never exposed （＂HCV-negative＂） to HCV. RESULTS： A total of 514 subjects were studied for HCV, of which 254 were HCV-positive and 260 HCV- negative donors comprised the control group. Mean age of the patients was 28.4 （Std 15.22） years. HCV-positive subjects were more likely to be of male gender （63% versus 37%）. Transfusion 132 （52%）, non-intravenous （n-iv） drug abuse and iv drug abuse 37 （14.5%）, haemodialysis 25 （10%）, receiving wounds at war and extramarital sexual activities （2.4%）, tattooing （3.6%） were found to be independent risk factors of being HCV-positive. No apparent risk factors could be demonstrated in 29 （11.2%） of the positive cases. CONCLUSION： Our data indicate that a history of transfusion and iv drug abuse and haemodialysis are important risk factors for HCV infection in our area and that more careful pretransfusion screening of blood for anti- HCV must be introduced in our blood banks. Improvements in certain lifestyle patterns, and customs in this area may be essential to prevent transmission of the infection.
文摘AIM： Celiac disease is characterized by life-long gluten intolerance. Clinical features of patients with celiac disease are variable. Studies about the prevalence of celiac disease in our country are scarce and there is no study on the prevalence of celiac disease in southern Iran. In the current study, clinical, laboratory and histological features of 52 patients with celiac disease were evaluated. METHODS： In a cross sectional study we retrospectively studied the characteristics of 52 celiac patients at Ahwaz JundiShapour University Hospitals （AJSUH） from November 1, 1999 to 1st Sep 2004. Intestinal biopsy and serum antigliadin and anti-endomysium antibodies were used for the diagnosis of patients. Mucosal lesions were classified according to the criteria of Marsh. Antigliadin antibodies were measured with a commercial enzyme-linked immunosorbent assay. Anti-endomysium antibodies were analyzed by indirect immunofluorescence with the use of a section of monkey esophagus. Routine hematological and biochemical analyses and measurement of immunoglobulin levels were undertaken.RESULTS： Male： female ratio was 1.08. The mean ＋ SD patient age was 21 ＋ 4.5 years （range 10-70 years） and the most common symptoms were diarrhea and weight loss （78.8%） followed by fatigue （73.1%）, pallor （65.4%）, anorexia （40.4%）, abdominal distention （32.7%）, and failure to thrive （23.1%）. Diarrhea and weight loss and fatigue were the most common findings. Iron deficiency anemia was found in 63.2% of patients and this became normal after adoption of a gluten-free diet in all patients. Immunoglobulin A, IgG antigliadin antibodies and IgA anti-endomysium antibodies were found in 33 and 48 cases, 78.8% and 85.4% of patients, respectively. Biopsy of the small intestine revealed that 90.4% of patients had typical lesions according to the Marsh classification. CONCLUSION： Although classical presentation was seen in most of the patients, atypical clinical manifestations of celiac disease should be kept
基金Supported by a Grant from Sports Medicine Research Center,Tehran University of Medical Sciences(No.1790)
文摘Objective： To analyze the effects of a Qigong program on various parameters of unstimulated saliva, including volume, pH and secretory immunoglobulin A （S-IgA） level. Methods： Twice a day from the beginning of Fall 2005, twenty-three healthy volunteers aged 22-24 did special Qigong exercises and massage of acupuncture points which stimulated the energy cycle and increased body water energy. The unstimulated saliva volume and pH were recorded every week in Spring （April, May, June） 2005 before the volunteers started to learn and exercise Qigong, and after Qigong intervention in Spring （April, May, June） 2006. During the period of study, saliva was collected in the same location and on similar dates at the Dental Faculty of Tehran University of Medical Sciences. The S-IgA levels of the last samples of the last week of Spring 2005 and 2006 were measured. Results： The unstimulated saliva volume after Qigong exercises （2.94±0.20 mL/5min） was significantly higher as compared to the pre-Qigong phase （1.65±0.102 mL/5min, P〈0.05）. The S-IgA level was 105.45±69.41 mg/mL before doing Qigong exercises, and 156.23±88.56 mg/mL after doing Qigong exercises, and a statistically significant difference was seen between the two measurements （P=0.005）. The change in pH was not statistically significant. Conclusions： The application of Qigong is beneficial for increasing salivary volume and other parameters. Moreover, the results suggest that Qigong may be a useful medication for patients with salivary hyposecretion. Further research is recommended in examining the long-term effects of Qigong on improving salivary volume and other parameters in individuals with salivary hyposecretion.
基金supported by the University of Guilanthe Iran Nanotechnology Initiative Council
文摘The structural and magnetic properties of the synthesized pure and functionalized CoFe2O4magnetic nanoparticles(NPs) are studied by analyzing the results from the x-ray diffraction(XRD), transmission electron microscopy(TEM), FT–IR spectroscopy, thermogravimetry(TG), and vibrating sample magnetometer(VSM). To extract the structure and lattice parameters from the XRD analysis results, we first apply the pseudo-Voigt model function to the experimental data obtained from XRD analysis and then the Rietveld algorithm is used in order to optimize the model function to estimate the true intensity values. Our simulated intensities are in good agreement with the experimental peaks, therefore, all structural parameters such as crystallite size and lattice constant are achieved through this simulation. Magnetic analysis reveals that the synthesized functionalized NPs have a saturation magnetization almost equal to that of pure nanoparticles(PNPs). It is also found that the presence of the turmeric causes a small reduction in coercivity of the functionalized NPs in comparison with PNP. Our TGA and FTIR results show that the turmeric is bonded very well to the surface of the NPs. So it can be inferred that a nancomposite(NC) powder of turmeric and nanoparticles is produced. As an application, the anti-arsenic characteristic of turmeric makes the synthesized functionalized NPs or NC powder a good candidate for arsenic removal from polluted industrial waste water.
文摘In this paper, we have investigated the prospects of exploiting the rich world thorium reserves using Canada Deuterium Uranium （CANDU） reactors. The analysis is performed using the Monte Carlo MCNP code in order to understand how much time the reactor is in criticality conduction. Four different fuel compositions have been selected for analysis. We have obtained the infinite multiplication factor, k∞, under full power operation of the reactor over 8 years. The neutronic flux distribution in the full core reactor has already been investigated.
基金Iran’s Nanotechnology initiative council for their financial support
文摘In this study, we investigate the photoluminescence （PL） properties of γ and θ-alumina nanoparticles synthesized by the chemical wet method followed by annealing. The obtained experimental results indicate the presence of some favorable near ultraviolet （NUV）-orange luminescent centers for usage in various luminescence applications, such as oxygen vacancies （F, F＋, F2＋, and F2 centers）, OH related defects, cation interstitial centers, and some new luminescence bands attributed to trapped-hole centers or donor-acceptor centers. The energy states of each defect are discussed in detail. The defects mentioned could alter the electronic structure by producing some energy states in the band gap that result in the optical absorption in the middle ultraviolet （MUV） region. Spectra show that photoionazation of F and F2 centers plays a crucial role in providing either free electrons for the conduction band, or the photoconversions of aggregated oxygen va- cancies into each other, or mobile electrons for electrons-holes recombination process by the Shockley-Read-Hall （SRH） mechanism.
文摘The extrusion process of hybrid sheet metals through arbitrarily curved dies was analyzed by the method of upper bound. The material under deformation was divided into two deformation regions, bimetal and mono-metal regions, and the flow of the material in each region was assumed as plane strain state. The internal, shearing and frictional power terms were derived and they were used in the upper bound model. The extrusion forces for two types of die shapes, an optimum wedge shaped die and an optimum streamlined die shape for a hybrid sheet composed of copper as sleeve and aluminum as core were determined. The corresponding results for those two die shapes were also determined by using the finite element code, ABAQUS, and compared with the upper bound results. These comparisons show a good agreement.
文摘Nearly 8.5 million people in Iran directly or indirectly make a living from hand-made carpet weaving industry. Ongoing work, poor postures, breathing problems and skin irritations are among factors affecting the health, safety and wellbeing of those involved in this industry. Hence, considering such factors seem to improve the quality of carpet as a valuable cultural commodity and expand its export. Accordingly, this study investigates the oxidative stress biomarkers among involved and non-involved people in the hand-made carpet industry. 25 carpet maker and 25 ordinary people (not involved in carpet industry) who had been matched for age and sex were selected as study groups. The level of oxidative stress biomarkers such as antioxidant capacity, total thiols and catalase were measured among subjects, and finally the biomarkers were compared between the two groups. To compare the oxidative stress biomarkers in two groups, Independent Sample T Test was used. The mean levels of total antioxidant capacity showed no significant difference between the two groups (0.05 p-value). In conclusion, carpet weaving industry induces oxidative stress and natural antioxidant may be considered beneficial for the protection of oxidative damage in such subjects.
文摘We report combination of explants and enzymatic protocol as mixed enzymatic-explant procedure to faster extraction of MSCs from WJ. Umbilical cords (UC) were collected from Imam Khomini Hospital. For explant outgrowth, 6 - 9 pieces of WJ were transferred onto tissue culture flask and waited for attachment. For mixed enzymatic-explant, 1 cm3 pieces WJ were placed in enzymatic cocktail comprising 4 mg/ml Collagenase Type I and 1 mg/ml Hyaluronidase and 0.1% trypsin-EDTA. Then isolated cells were analyzed for surface cell markers such as CD73, CD31. Isolated 1.0 × 106 MSCs/ml were encapsulated in alginate hydrogel. Cells with MSCs phenotype were isolated from mixed enzymatic-explant and explant procedures within 24 - 48 hrs and 7 - 10 days, respectively. Both of procedures were shown to form clumps and colonies with dense centers. Phenotypic changes gradually appeared as round cell in UC pieces into homogeneous spindle-shaped and typical fibroblast-like shape cells. By using flow cytometery MSCs showed positive for CD73, and negative for CD31. the morphology of viable MSCs in the beads did not significantly show a different morphology pattern before and after the bead formation process. These findings are indicated that when mixed enzymatic-explant procedure is performed MSCs can be isolated faster and much higher from WJ. These finding is important in comparing with time consuming explants culture for isolation of MSCs.
