A A cerium-based chemical conversion process was studied. First, zinc coating obtained from a free-cyanide alkaline bath, with derivative of imidazol with new brightener, was investigated, zinc-plated steel specimens...A A cerium-based chemical conversion process was studied. First, zinc coating obtained from a free-cyanide alkaline bath, with derivative of imidazol with new brightener, was investigated, zinc-plated steel specimens were treated with a solution of 50 mmol· L^-1 Ce（NO3 ）3 The corrosion behavior of bare and treated mild galvanized steel was evaluated during exposure to 0.5 mol · L^-1 NaCl for different immersion time, using Tafel polarization curves and electrochemical impedance spectroscopy （EIS） measurements. The surface morphology of the coating was studied using scanning electron microscopy （SEM）. The composition and chemical percent of the coating were examined by X-ray dispersion energy （EDAX）. The results of these measurements showed that the newly developed cerium-based conversion coating process was a promising candidate for replacing the conventional chromate treatments used at present for galvanized steel.展开更多
AIM:To assess the efficacy of N-acetylcysteine(NAC) and activated Dimethicone in improving endoscopic mucosal visibility.METHODS:A total of 148 patients were randomly allocated into four groups to receive one of the f...AIM:To assess the efficacy of N-acetylcysteine(NAC) and activated Dimethicone in improving endoscopic mucosal visibility.METHODS:A total of 148 patients were randomly allocated into four groups to receive one of the following premedications:group A:100 mL water alone;group B:activated Dimethicone plus water(up to 100 mL);group C:NAC plus water(up to 100 mL);and group D:activated Dimethicone and NAC plus water(up to 100 mL).A single endoscopist blinded to the patients group assessed the gastric mucosal visibility scores(range 1-4) at four sites.The sum of the scores from the four sites was considered as the total mucosal visibility score(TMVS).RESULTS:The patients in group B showed a significantly lower TMVS than those of groups A and C(P < 0.001).The TMVS in patients of group D was significantly lower than that of groups A and C(P < 0.001).The TMVS did not significantly differ between groups B and D(P > 0.05).The difference between TMVS of groups C and A was not significant(P > 0.05).CONCLUSION:Premedication with activated Dimethicone 20 min prior to the upper endoscopy leads to the best visibility.NAC does not improve visualization by itself.展开更多
The mechanical behavior of plastic concrete used in the cut-off walls of earth dams has been studied. Triaxial compression tests on the specimens in various ages and mix designs under different confining pressures hav...The mechanical behavior of plastic concrete used in the cut-off walls of earth dams has been studied. Triaxial compression tests on the specimens in various ages and mix designs under different confining pressures have been done and the stress-strain behavior of such materials and their strength parameter changes have been experimentally investigated. It has been observed that increasing the confining pressures applied on the specimens causes the material behavior to be alike the more ductile materials and the compressive strength increases considerably as well. Moreover, a parametric study has been carded out to investigate the influence of essential parameters on the shear strength parameters of these materials. According to the research, increasing the coarse to fine aggregates ratio leads to the increase of compressive strength of the specimens as well as the increase of the cohesion and internal friction angle of the materials. Furthermore, the bentonite content decrease and the cement factor increase result in an increase of the cohesion parameter of plastic concretes and decrease of the internal friction angle of such materials.展开更多
AIM: To study the loss of heterozygosity (LOH) at 8p21-23 locus in diffuse gastric cancer.METHODS: To evaluate the involvement of this region in gastric cancer, we used eight microsatellite markers covering two Mb of ...AIM: To study the loss of heterozygosity (LOH) at 8p21-23 locus in diffuse gastric cancer.METHODS: To evaluate the involvement of this region in gastric cancer, we used eight microsatellite markers covering two Mb of mentioned region, to perform a high-resolution analysis of allele loss in 42 cases of late diffuse gastric adenocarcinoma.RESULTS: Six of these STS makers: D8S1149, D8S1645, D8S1643, D8S1508, D8S1591, and D8S1145 showed 36%, 28%, 37%, 41%, 44% and 53% LOH, respectively.CONCLUSION: A critical region of loss, close to the NAT2 locus and relatively far from FEZ1 gene currently postulated as tumor suppressor gene in this region.展开更多
Water flooding and pressure maintenance are recommended to improve oil recovery practices after low recovery of petroleum reservoirs occurs during primary production.Salt crystal formation is a frequent occurrence whe...Water flooding and pressure maintenance are recommended to improve oil recovery practices after low recovery of petroleum reservoirs occurs during primary production.Salt crystal formation is a frequent occurrence when using these techniques.Several experimental,numerical,and theoretical studies have been done on the mechanisms underlying scaling and permeability reduction in porous media;however,there has not been a satisfactory model developed.This study developed a phenomenological model to predict formation damage caused by salt deposition.Compared with existing models,which provide a scaling tendency,the proposed model predicts the profile of scale deposition.The salt precipitation model simulates reactive fluid flow through porous media.A thermodynamic,kinetic,and flow hydrodynamic model was developed and coupled with the ion transport equation to describe the movement of ions.Further,a set of carefully designed dynamic experiments were conducted and the data were compared with the model predictions.Model forecasts and experimental data were observed to have an average absolute error(AAE)ranging from 0.68%to 5.94%,which indicates the model's suitability.展开更多
This research examines the impact of wettability alteration on the end points of relative permeability,a crucial property of fluids and porous media that influences the displacement processes of immiscible fluids thro...This research examines the impact of wettability alteration on the end points of relative permeability,a crucial property of fluids and porous media that influences the displacement processes of immiscible fluids through such media.The estimation of the mobility ratio for oil recovery relies on these end points,which are influenced by connate water saturation and residual oil saturation.To investigate this relationship,carbonate rock is generally subjected to wettability alteration using surfactant agents,and core flooding is employed to determine the relative permeability before and after the alteration.The wettability of the rock is commonly assessed through contact angle measurements.Two surfactants,TritonX-100(Tx-100)and Cedar,were tested in reducing the wettability of the porous media for oil.The contact angle measurements revealed that Tx-100 was more effective for this purpose than Cedar.Furthermore,the relative permeability tests indicated that both surfactants decreased residual oil saturation,but Tx-100 also improved system pressure.In contrast,Cedar reduced residual oil saturation but increased system pressure,possibly because of its high viscosity.The results also demonstrate that injecting Tx-100 leads to a 14%increase in ultimate oil recovery compared with water injection,while Cedar injection increased the recovery factor by 5%.This difference may be attributed to the incomplete coverage of the pore wall by Cedar or its weaker chemical structure than Tx-100.Notably,in carbonate cores,neither non-ionic surfactant enhanced oil recovery.展开更多
Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of s...Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica （L.） Willd. ex Del., Prosopis juliflora （Sw.） DC. ：and Dodonaea viscosa （L.） Jacq. The following treatments were applied： T1, untreated seed （control）; T2, sulphuric acid （97%） for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog （MS） medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable Seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds （80.8%-90.8%） and for scarified seeds of A. nilotica （50.2%） boiled in water. The germination indices, i.e., final germination percentage （FG）, mean daily germination （MDG） and germination rate （GR）, were significantly affected by treatments and species （p 〈 0.01）.展开更多
Pathological scarring imposes a major clinical and social burden worldwide.Human cutaneous wounds are responsive to mechanical forces and convert mechanical cues to biochemical signals that eventually promote scarring...Pathological scarring imposes a major clinical and social burden worldwide.Human cutaneous wounds are responsive to mechanical forces and convert mechanical cues to biochemical signals that eventually promote scarring.To understand the mechanotransduction pathways in cutaneous scarring and develop new mechanotherapy approaches to achieve optimal scarring,the current study highlights the mechanical behavior of unwounded and scarred skin as well as intra-and extracellular mechanisms behind keloid and hypertrophic scars.Additionally,the therapeutic interventions that promote optimal scar healing by mechanical means at the molecular,cellular or tissue level are extensively reviewed.The current literature highlights the significant role of fibroblasts in wound contraction and scar formation via differentiation intomyofibroblasts.Thus,understanding myofibroblasts and their responses to mechanical loading allows the development of new scar therapeutics.A review of the current clinical and preclinical studies suggests that existing treatment strategies only reduce scarring on a small scale after wound closure and result in poor functional and aesthetic outcomes.Therefore,the perspective of mechanotherapies needs to consider the application of both mechanical forces and biochemical cues to achieve optimal scarring.Moreover,early intervention is critical in wound management;thus,mechanoregulation should be conducted during the healing process to avoid scar maturation.Future studies should either consider combining mechanical loading(pressure)therapies with tension offloading approaches for scar management or developing more effective early therapies based on contraction-blocking biomaterials for the prevention of pathological scarring.展开更多
Naturally fractured carbonate reservoirs have very low oil recovery efficiency owing to their wettability and tightness of matrix.However,smart water can enhance oil recovery by changing the wettability of the carbona...Naturally fractured carbonate reservoirs have very low oil recovery efficiency owing to their wettability and tightness of matrix.However,smart water can enhance oil recovery by changing the wettability of the carbonate rock surface from oilwet to water-wet,and the addition of surfactants can also change surface wettability.In the present study,the effects of a solution of modified seawater with some surfactants,namely C12 TAB,SDS,and TritonX-100(TX-100),on the wettability of carbonate rock were investigated through contact angle measurements.Oil recovery was studied using spontaneous imbibition tests at 25,70,and 90°C,followed by thermal gravity analysis to measure the amount of adsorbed material on the carbonate surface.The results indicated that Ca2+,Mg2+,and SO42-.ions may alter the carbonate rock wettability from oil-wet to water-wet,with further water wettability obtained at higher concentrations of the ions in modified seawater.Removal of NaCl from the imbibing fluid resulted in a reduced contact angle and significantly enhanced oil recovery.Low oil recoveries were obtained with modified seawater at 25 and 70°C,but once the temperature was increased to 90°C,the oil recovery in the spontaneous imbibition experiment increased dramatically.Application of smart water with C12 TAB surfactant at 0.1 wt%changed the contact angle from 161°to 52°and enhanced oil recovery to 72%,while the presence of the anionic surfactant SDS at 0.1 wt%in the smart water increased oil recovery to 64.5%.The TGA analysis results indicated that the adsorbed materials on the carbonate surface were minimal for the solution containing seawater with C12 TAB at 0.1 wt%(SW+CTAB(0.1 wt%)).Based on the experimental results,a mechanism was proposed for wettability alteration of carbonate rocks using smart water with SDS and C12 TAB surfactants.展开更多
AIM:To evaluate the changes in the anterior segment parameters of the subjects with primary angle closure suspect(PACS) before and after laser iridotomy(LI) using the Pentacam and gonioscopy. METHODS:Forty-eight eyes ...AIM:To evaluate the changes in the anterior segment parameters of the subjects with primary angle closure suspect(PACS) before and after laser iridotomy(LI) using the Pentacam and gonioscopy. METHODS:Forty-eight eyes of 48 PACS were included.Anterior chamber angle(ACA),central anterior chamber depth(ACD),anterior chamber volume(ACV) and central corneal thickness(CCT) were recorded from the Pentacam before and one month after LI.ACA was graded according to Shaffer classification using Goldmann gonioscopy.RESULTS:ACA increased significantly from 25.59±4.41 to 26.46±4.33 degrees(P=0.009) and ACV changed from 85.97±16.07mm3to 99.25±15.83mm3(P=0.000).The changes in ACD,CCT and intraocular pressure were non-significant(P】0.05).Gonioscopy showed significant widening of the Shaffer angle in 4 quadrants(P【0.001).CONCLUSION:Pentacam can serve as the objective instrument in assessing the efficacy of LI.展开更多
AIM:To evaluate joint effects of Methylentetra-hydrofolate reductase(MTHFR) C677T genotypes,and serum folate/vitamin B12 concentrations on promoter methylation of tumor-associated genes among Iranian colorectal cancer...AIM:To evaluate joint effects of Methylentetra-hydrofolate reductase(MTHFR) C677T genotypes,and serum folate/vitamin B12 concentrations on promoter methylation of tumor-associated genes among Iranian colorectal cancer patients. METHODS:We examined the associations between MTHFR C677T genotype,and promoter methylation of P16,hMLH1,and hMSH2 tumor-related genes among151 sporadic colorectal cancer patients. The promoter methylation of tumor-related genes was determined by methylation-specific PCR. Eighty six patients from whom fresh tumor samples were obtained and 81 controls were also examined for serum folate and vitamin B12 concentrations by a commercial radioimmunoassay kit. RESULTS:We found 29.1% of cases had tumors with at least one methylated gene promoter. In case-case comparison,we did not find a significant association between methylation in tumors and any single genotype. However,in comparison to controls with the CC genotype,an increased risk of tumor methylation was associated with the CT genotype(OR = 2.5;95% CI,1.1-5.6) . In case-case comparisons,folate/vitamin B12 levels were positively associated with tumor methylation. Adjusted odds ratios for tumor methylation in cases with high(above median) versus low(below median) serum folate/vitamin B12 levels were 4.9(95% CI,1.4-17.7) ,and 3.9(95% CI,1.1-13.9) ,respectively. The frequency of methylated tumors was significantly higher in high methyl donor than low methyl donor group,especially in those with MTHFR CT(P = 0.01) ,and CT/TT(P = 0.002) genotypes,but not in those with the CC genotype(P = 1.0) . CONCLUSION:We conclude that high concentrations of serum folate/vitamin B12 levels are associated with the risk of promoter methylation in tumor-specific genes,and this relationship is modified by MTHFR C677T genotypes.展开更多
Nanostructured LaFeO3 and substituted LaZnxFe1-xO3(x = 0.01,0.05,0.1,0.2,and 0.3) perovskites were synthesized by the sol-gel auto-combustion method and used in the catalytic combustion of toluene.Their structures and...Nanostructured LaFeO3 and substituted LaZnxFe1-xO3(x = 0.01,0.05,0.1,0.2,and 0.3) perovskites were synthesized by the sol-gel auto-combustion method and used in the catalytic combustion of toluene.Their structures and surface properties were investigated by X-ray diffraction,Fourier transmission infrared spectroscopy,BET surface area,and scanning electron microscopy.Characterization data revealed that the total insertion of zinc into LaFeO3 takes place when x ≤ 0.1.However,ZnO segregation occurs to some extent,especially at x > 0.1.The performance of these perovskites was evaluated by toluene combustion.The catalytic activity of the catalysts increased substantially with an increase in zinc substitution.These results can be attributed to the cooperative effect between LaZnxFe1-xO3 and the zinc oxide phases.The relative concentration of these phases determines their oxygen activation ability and reactivity.展开更多
AIM:To evaluate the contribution of the G-197A polymorphism in the interleukin-17(IL-17)promoter region to gastric cancer risk in an Iranian population.METHODS:We performed a case control study using samples from 161 ...AIM:To evaluate the contribution of the G-197A polymorphism in the interleukin-17(IL-17)promoter region to gastric cancer risk in an Iranian population.METHODS:We performed a case control study using samples from 161 individuals with gastric cancer and171 healthy controls.For each individual,the G-197A genotype was determined by restriction fragment length polymorphism analysis of polymerase chain reaction-amplified fragments.Statistical analyses were performed to determine whether any demographic or behavioral factors,infection with Helicobacter pylori(H.pylori),or a particular G-197A genotype was associated with gastric cancer risk.RESULTS:We found that the G-197A genotype wassignificantly associated with increased gastric cancer risk(P=0.001).Patients who were homozygous(AA)at position-197 were 2.9 times more likely to develop disease(95%CI:1.56-5.4;P=0.001).Furthermore,logistic regression analysis revealed that the presence of a single A allele increased the risk of gastric cancer up to 1.7-fold(95%CI:1.26-2.369;P=0.001).This association was observed for early stage gastric adenocarcinomas only,and was not linked to H.pylori infection.CONCLUSION:These results suggest that carrying one or more G-197A polymorphisms at position-197 in the IL-17 promoter region significantly increases gastric cancer risk in this patient population.展开更多
In this work, the mixing and segregation of binary mixtures of particles with different sizes and densities in a pseudo-2D spouted bed were studied experimentally. A binary mixture of solid particles including sand, g...In this work, the mixing and segregation of binary mixtures of particles with different sizes and densities in a pseudo-2D spouted bed were studied experimentally. A binary mixture of solid particles including sand, gypsum, and polyurethane was used. To determine the particles mass fraction, and their mixing and segregation in the bed, an image-processing technique was developed and used. Important hydrodynamic parameters, such as the axial and radial segregation profiles of the solid particles, were measured. The effects of air velocity, particle size, and particle mass fraction were also evaluated. The flow regime in the spouted bed and the time required for reaching the equilibrium state of the solid particles were discussed. The results showed that the segregation of solid particles and the time to equilibrium both decreased when the air velocity increased to much larger than the minimum spouting velocity. The axia! segregation increased with the diameter ratio of the particles. Upon completion of the test, coarse particles were concentrated mainly in the spout region, while fine particles were aggregated in the annulus region. Examination of the flow pattern in the spouted bed showed that the particles near the wall had longer flow paths, while those near the spout region had shorter flow paths.展开更多
AIM:To report the cytology results of 25-gauge transconjunctival(25G-TSV)diagnostic vitrectomy in cases suspicious for intraocular lymphoma(IOL),and compare the results to those reported in the literature.METHODS:Clin...AIM:To report the cytology results of 25-gauge transconjunctival(25G-TSV)diagnostic vitrectomy in cases suspicious for intraocular lymphoma(IOL),and compare the results to those reported in the literature.METHODS:Clinical and cytopathological records of 18vitreous biopsy specimens obtained via 25G-TSV diagnostic vitrectomy in 12 patients suspicious for IOL were reviewed retrospectively.A review of the literature in regards to the diagnostic yields of vitreous specimens obtained via 25-gauge and 20-gauge diagnostic vitrectomy in suspected cases of IOL was performed.RESULTS:Eighteen eyes from 12 patients with clinical suspicion of IOL underwent diagnostic 25G-TSV.The cytopathological investigations demonstrated IOL in 15eyes(83.3%).Vitreous analysis was non-diagnostic in 3eyes(16.7%).CONCLUSION:Twenty-five-gauge diagnostic vitrectomy yields adequate sample for cytological evaluation of the vitreous in cases suspicious for IOL.The diagnostic results of the 25G-TSV in the current study are superior to those reported for 20-gauge vitrectomy but equivalent to those reported for 25G-TSV in the published literature.展开更多
The energy absorption capacity of the Al5083 thin-walled tube produced by parallel tubular angular pressing(PTCAP) process was evaluated. Also, microstructure, mechanical properties, and anisotropy coefficients were s...The energy absorption capacity of the Al5083 thin-walled tube produced by parallel tubular angular pressing(PTCAP) process was evaluated. Also, microstructure, mechanical properties, and anisotropy coefficients were studied in the peripheral and axial directions. Results showed that values of energy absorption decreased with processing pass increasing and the values for the unprocessed, first and second passes were obtained to be 167, 161.4 and 160.7 J, respectively. The differences between the simulation results for the energy absorption values and their experimental values for the unprocessed, the first and the second PTCAP passes samples are about 5%, 10%, and 13%, respectively. The energy absorption capacity was related to the anisotropy coefficient and microstructure. The results demonstrated that grain refinement occurred and ultimate tensile strength(UTS) and microhardness after the first and second PTCAP passes were enhanced, while the increase rate in the first pass was much severer. Also, by applying PTCAP, the deformation modes were altered, such that the deformation mode of the annealed tube was quite symmetrical and circular while for the first and second passes there have been triple and double lobes diamond. The results of the numerical simulation for the deformation mode of the annealed and PTCAPed tubes were consistent with the experimental results. The deformation mode of tubes is dependent on their mechanical properties and variation of the mechanical properties during PTCAP process.展开更多
AIM： To investigate the association of the inducible ni- tric oxide synthetase （iNOS） C150T polymorphism with Helicobacter pylori （H. pylor/） infection and gastric can- cer （GC） risk in Iran. METHODS： In order...AIM： To investigate the association of the inducible ni- tric oxide synthetase （iNOS） C150T polymorphism with Helicobacter pylori （H. pylor/） infection and gastric can- cer （GC） risk in Iran. METHODS： In order to determine whether there was a correlation between iNOS genotype and GC in Iran, we conducted a case-control study using samples from 329 individuals. For each sample, the C150T ilVOS poly- morphism was genotyped by polymerase chain reaction （PCR） and restriction digestion. Patients were grouped by cancer presence, demographic and behavior charac- teristics, and/-/, pylori infection status. Statistical tests were conducted to determine whether any behavioral factors or a particular iNOS genotype was associated with GC in the study population. RESULTS： In this population, we found that smok- ing, hot beverage consumption, a familial history of GC and H. pylori infection status were significantly associated with GC development （P = 0.015, P 〈 0.001, P = 0.0034, and P 〈 0.015, respectively）. The distribution of the C150T ilVOS genotypes among the two study groups was not statistically significant alone, but was impacted by H. pylori infection status. When compared to the non-/-/, pylori infected group, cancer patients who had a heterozygous CT genotype and were also infected with H. pylori were 2.1 times more at risk of developing GC [odds ratio （OR） = 2.1, P = 0.03] while those with a homozygous TT genotype and infected with H. pylori were 5.0 times more at risk of developing GC （OR = 5.0, P = 0.029）. In contrast, this association was not seen in patients in the control group.CONCLUSION： ACT or TT polymorphism at position 150 in the iNO$ gene significantly increases the risk of GC and may be a marker for GC susceptibility.展开更多
基金Project supported by the Office of the New Material and Clean Chemistry Research of the Tabriz University
文摘A A cerium-based chemical conversion process was studied. First, zinc coating obtained from a free-cyanide alkaline bath, with derivative of imidazol with new brightener, was investigated, zinc-plated steel specimens were treated with a solution of 50 mmol· L^-1 Ce（NO3 ）3 The corrosion behavior of bare and treated mild galvanized steel was evaluated during exposure to 0.5 mol · L^-1 NaCl for different immersion time, using Tafel polarization curves and electrochemical impedance spectroscopy （EIS） measurements. The surface morphology of the coating was studied using scanning electron microscopy （SEM）. The composition and chemical percent of the coating were examined by X-ray dispersion energy （EDAX）. The results of these measurements showed that the newly developed cerium-based conversion coating process was a promising candidate for replacing the conventional chromate treatments used at present for galvanized steel.
文摘AIM:To assess the efficacy of N-acetylcysteine(NAC) and activated Dimethicone in improving endoscopic mucosal visibility.METHODS:A total of 148 patients were randomly allocated into four groups to receive one of the following premedications:group A:100 mL water alone;group B:activated Dimethicone plus water(up to 100 mL);group C:NAC plus water(up to 100 mL);and group D:activated Dimethicone and NAC plus water(up to 100 mL).A single endoscopist blinded to the patients group assessed the gastric mucosal visibility scores(range 1-4) at four sites.The sum of the scores from the four sites was considered as the total mucosal visibility score(TMVS).RESULTS:The patients in group B showed a significantly lower TMVS than those of groups A and C(P < 0.001).The TMVS in patients of group D was significantly lower than that of groups A and C(P < 0.001).The TMVS did not significantly differ between groups B and D(P > 0.05).The difference between TMVS of groups C and A was not significant(P > 0.05).CONCLUSION:Premedication with activated Dimethicone 20 min prior to the upper endoscopy leads to the best visibility.NAC does not improve visualization by itself.
文摘The mechanical behavior of plastic concrete used in the cut-off walls of earth dams has been studied. Triaxial compression tests on the specimens in various ages and mix designs under different confining pressures have been done and the stress-strain behavior of such materials and their strength parameter changes have been experimentally investigated. It has been observed that increasing the confining pressures applied on the specimens causes the material behavior to be alike the more ductile materials and the compressive strength increases considerably as well. Moreover, a parametric study has been carded out to investigate the influence of essential parameters on the shear strength parameters of these materials. According to the research, increasing the coarse to fine aggregates ratio leads to the increase of compressive strength of the specimens as well as the increase of the cohesion and internal friction angle of the materials. Furthermore, the bentonite content decrease and the cement factor increase result in an increase of the cohesion parameter of plastic concretes and decrease of the internal friction angle of such materials.
基金Supported by Research Center of Gastric and Liver Disease in Tehran Taleghani hospital
文摘AIM: To study the loss of heterozygosity (LOH) at 8p21-23 locus in diffuse gastric cancer.METHODS: To evaluate the involvement of this region in gastric cancer, we used eight microsatellite markers covering two Mb of mentioned region, to perform a high-resolution analysis of allele loss in 42 cases of late diffuse gastric adenocarcinoma.RESULTS: Six of these STS makers: D8S1149, D8S1645, D8S1643, D8S1508, D8S1591, and D8S1145 showed 36%, 28%, 37%, 41%, 44% and 53% LOH, respectively.CONCLUSION: A critical region of loss, close to the NAT2 locus and relatively far from FEZ1 gene currently postulated as tumor suppressor gene in this region.
文摘Water flooding and pressure maintenance are recommended to improve oil recovery practices after low recovery of petroleum reservoirs occurs during primary production.Salt crystal formation is a frequent occurrence when using these techniques.Several experimental,numerical,and theoretical studies have been done on the mechanisms underlying scaling and permeability reduction in porous media;however,there has not been a satisfactory model developed.This study developed a phenomenological model to predict formation damage caused by salt deposition.Compared with existing models,which provide a scaling tendency,the proposed model predicts the profile of scale deposition.The salt precipitation model simulates reactive fluid flow through porous media.A thermodynamic,kinetic,and flow hydrodynamic model was developed and coupled with the ion transport equation to describe the movement of ions.Further,a set of carefully designed dynamic experiments were conducted and the data were compared with the model predictions.Model forecasts and experimental data were observed to have an average absolute error(AAE)ranging from 0.68%to 5.94%,which indicates the model's suitability.
文摘This research examines the impact of wettability alteration on the end points of relative permeability,a crucial property of fluids and porous media that influences the displacement processes of immiscible fluids through such media.The estimation of the mobility ratio for oil recovery relies on these end points,which are influenced by connate water saturation and residual oil saturation.To investigate this relationship,carbonate rock is generally subjected to wettability alteration using surfactant agents,and core flooding is employed to determine the relative permeability before and after the alteration.The wettability of the rock is commonly assessed through contact angle measurements.Two surfactants,TritonX-100(Tx-100)and Cedar,were tested in reducing the wettability of the porous media for oil.The contact angle measurements revealed that Tx-100 was more effective for this purpose than Cedar.Furthermore,the relative permeability tests indicated that both surfactants decreased residual oil saturation,but Tx-100 also improved system pressure.In contrast,Cedar reduced residual oil saturation but increased system pressure,possibly because of its high viscosity.The results also demonstrate that injecting Tx-100 leads to a 14%increase in ultimate oil recovery compared with water injection,while Cedar injection increased the recovery factor by 5%.This difference may be attributed to the incomplete coverage of the pore wall by Cedar or its weaker chemical structure than Tx-100.Notably,in carbonate cores,neither non-ionic surfactant enhanced oil recovery.
文摘Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless ,specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica （L.） Willd. ex Del., Prosopis juliflora （Sw.） DC. ：and Dodonaea viscosa （L.） Jacq. The following treatments were applied： T1, untreated seed （control）; T2, sulphuric acid （97%） for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog （MS） medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable Seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds （80.8%-90.8%） and for scarified seeds of A. nilotica （50.2%） boiled in water. The germination indices, i.e., final germination percentage （FG）, mean daily germination （MDG） and germination rate （GR）, were significantly affected by treatments and species （p 〈 0.01）.
文摘Pathological scarring imposes a major clinical and social burden worldwide.Human cutaneous wounds are responsive to mechanical forces and convert mechanical cues to biochemical signals that eventually promote scarring.To understand the mechanotransduction pathways in cutaneous scarring and develop new mechanotherapy approaches to achieve optimal scarring,the current study highlights the mechanical behavior of unwounded and scarred skin as well as intra-and extracellular mechanisms behind keloid and hypertrophic scars.Additionally,the therapeutic interventions that promote optimal scar healing by mechanical means at the molecular,cellular or tissue level are extensively reviewed.The current literature highlights the significant role of fibroblasts in wound contraction and scar formation via differentiation intomyofibroblasts.Thus,understanding myofibroblasts and their responses to mechanical loading allows the development of new scar therapeutics.A review of the current clinical and preclinical studies suggests that existing treatment strategies only reduce scarring on a small scale after wound closure and result in poor functional and aesthetic outcomes.Therefore,the perspective of mechanotherapies needs to consider the application of both mechanical forces and biochemical cues to achieve optimal scarring.Moreover,early intervention is critical in wound management;thus,mechanoregulation should be conducted during the healing process to avoid scar maturation.Future studies should either consider combining mechanical loading(pressure)therapies with tension offloading approaches for scar management or developing more effective early therapies based on contraction-blocking biomaterials for the prevention of pathological scarring.
文摘Naturally fractured carbonate reservoirs have very low oil recovery efficiency owing to their wettability and tightness of matrix.However,smart water can enhance oil recovery by changing the wettability of the carbonate rock surface from oilwet to water-wet,and the addition of surfactants can also change surface wettability.In the present study,the effects of a solution of modified seawater with some surfactants,namely C12 TAB,SDS,and TritonX-100(TX-100),on the wettability of carbonate rock were investigated through contact angle measurements.Oil recovery was studied using spontaneous imbibition tests at 25,70,and 90°C,followed by thermal gravity analysis to measure the amount of adsorbed material on the carbonate surface.The results indicated that Ca2+,Mg2+,and SO42-.ions may alter the carbonate rock wettability from oil-wet to water-wet,with further water wettability obtained at higher concentrations of the ions in modified seawater.Removal of NaCl from the imbibing fluid resulted in a reduced contact angle and significantly enhanced oil recovery.Low oil recoveries were obtained with modified seawater at 25 and 70°C,but once the temperature was increased to 90°C,the oil recovery in the spontaneous imbibition experiment increased dramatically.Application of smart water with C12 TAB surfactant at 0.1 wt%changed the contact angle from 161°to 52°and enhanced oil recovery to 72%,while the presence of the anionic surfactant SDS at 0.1 wt%in the smart water increased oil recovery to 64.5%.The TGA analysis results indicated that the adsorbed materials on the carbonate surface were minimal for the solution containing seawater with C12 TAB at 0.1 wt%(SW+CTAB(0.1 wt%)).Based on the experimental results,a mechanism was proposed for wettability alteration of carbonate rocks using smart water with SDS and C12 TAB surfactants.
文摘AIM:To evaluate the changes in the anterior segment parameters of the subjects with primary angle closure suspect(PACS) before and after laser iridotomy(LI) using the Pentacam and gonioscopy. METHODS:Forty-eight eyes of 48 PACS were included.Anterior chamber angle(ACA),central anterior chamber depth(ACD),anterior chamber volume(ACV) and central corneal thickness(CCT) were recorded from the Pentacam before and one month after LI.ACA was graded according to Shaffer classification using Goldmann gonioscopy.RESULTS:ACA increased significantly from 25.59±4.41 to 26.46±4.33 degrees(P=0.009) and ACV changed from 85.97±16.07mm3to 99.25±15.83mm3(P=0.000).The changes in ACD,CCT and intraocular pressure were non-significant(P】0.05).Gonioscopy showed significant widening of the Shaffer angle in 4 quadrants(P【0.001).CONCLUSION:Pentacam can serve as the objective instrument in assessing the efficacy of LI.
基金The office of the Vice Chancellor for Research, Shiraz University of Medical Sciences, No. 83-2212 Grant from the Gastroenterohepatology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
文摘AIM:To evaluate joint effects of Methylentetra-hydrofolate reductase(MTHFR) C677T genotypes,and serum folate/vitamin B12 concentrations on promoter methylation of tumor-associated genes among Iranian colorectal cancer patients. METHODS:We examined the associations between MTHFR C677T genotype,and promoter methylation of P16,hMLH1,and hMSH2 tumor-related genes among151 sporadic colorectal cancer patients. The promoter methylation of tumor-related genes was determined by methylation-specific PCR. Eighty six patients from whom fresh tumor samples were obtained and 81 controls were also examined for serum folate and vitamin B12 concentrations by a commercial radioimmunoassay kit. RESULTS:We found 29.1% of cases had tumors with at least one methylated gene promoter. In case-case comparison,we did not find a significant association between methylation in tumors and any single genotype. However,in comparison to controls with the CC genotype,an increased risk of tumor methylation was associated with the CT genotype(OR = 2.5;95% CI,1.1-5.6) . In case-case comparisons,folate/vitamin B12 levels were positively associated with tumor methylation. Adjusted odds ratios for tumor methylation in cases with high(above median) versus low(below median) serum folate/vitamin B12 levels were 4.9(95% CI,1.4-17.7) ,and 3.9(95% CI,1.1-13.9) ,respectively. The frequency of methylated tumors was significantly higher in high methyl donor than low methyl donor group,especially in those with MTHFR CT(P = 0.01) ,and CT/TT(P = 0.002) genotypes,but not in those with the CC genotype(P = 1.0) . CONCLUSION:We conclude that high concentrations of serum folate/vitamin B12 levels are associated with the risk of promoter methylation in tumor-specific genes,and this relationship is modified by MTHFR C677T genotypes.
基金the Iranian Nanotechnology Initiative for financial support
文摘Nanostructured LaFeO3 and substituted LaZnxFe1-xO3(x = 0.01,0.05,0.1,0.2,and 0.3) perovskites were synthesized by the sol-gel auto-combustion method and used in the catalytic combustion of toluene.Their structures and surface properties were investigated by X-ray diffraction,Fourier transmission infrared spectroscopy,BET surface area,and scanning electron microscopy.Characterization data revealed that the total insertion of zinc into LaFeO3 takes place when x ≤ 0.1.However,ZnO segregation occurs to some extent,especially at x > 0.1.The performance of these perovskites was evaluated by toluene combustion.The catalytic activity of the catalysts increased substantially with an increase in zinc substitution.These results can be attributed to the cooperative effect between LaZnxFe1-xO3 and the zinc oxide phases.The relative concentration of these phases determines their oxygen activation ability and reactivity.
基金Supported by The Mazandaran University of Medical Sciences,No.89-512
文摘AIM:To evaluate the contribution of the G-197A polymorphism in the interleukin-17(IL-17)promoter region to gastric cancer risk in an Iranian population.METHODS:We performed a case control study using samples from 161 individuals with gastric cancer and171 healthy controls.For each individual,the G-197A genotype was determined by restriction fragment length polymorphism analysis of polymerase chain reaction-amplified fragments.Statistical analyses were performed to determine whether any demographic or behavioral factors,infection with Helicobacter pylori(H.pylori),or a particular G-197A genotype was associated with gastric cancer risk.RESULTS:We found that the G-197A genotype wassignificantly associated with increased gastric cancer risk(P=0.001).Patients who were homozygous(AA)at position-197 were 2.9 times more likely to develop disease(95%CI:1.56-5.4;P=0.001).Furthermore,logistic regression analysis revealed that the presence of a single A allele increased the risk of gastric cancer up to 1.7-fold(95%CI:1.26-2.369;P=0.001).This association was observed for early stage gastric adenocarcinomas only,and was not linked to H.pylori infection.CONCLUSION:These results suggest that carrying one or more G-197A polymorphisms at position-197 in the IL-17 promoter region significantly increases gastric cancer risk in this patient population.
文摘In this work, the mixing and segregation of binary mixtures of particles with different sizes and densities in a pseudo-2D spouted bed were studied experimentally. A binary mixture of solid particles including sand, gypsum, and polyurethane was used. To determine the particles mass fraction, and their mixing and segregation in the bed, an image-processing technique was developed and used. Important hydrodynamic parameters, such as the axial and radial segregation profiles of the solid particles, were measured. The effects of air velocity, particle size, and particle mass fraction were also evaluated. The flow regime in the spouted bed and the time required for reaching the equilibrium state of the solid particles were discussed. The results showed that the segregation of solid particles and the time to equilibrium both decreased when the air velocity increased to much larger than the minimum spouting velocity. The axia! segregation increased with the diameter ratio of the particles. Upon completion of the test, coarse particles were concentrated mainly in the spout region, while fine particles were aggregated in the annulus region. Examination of the flow pattern in the spouted bed showed that the particles near the wall had longer flow paths, while those near the spout region had shorter flow paths.
文摘AIM:To report the cytology results of 25-gauge transconjunctival(25G-TSV)diagnostic vitrectomy in cases suspicious for intraocular lymphoma(IOL),and compare the results to those reported in the literature.METHODS:Clinical and cytopathological records of 18vitreous biopsy specimens obtained via 25G-TSV diagnostic vitrectomy in 12 patients suspicious for IOL were reviewed retrospectively.A review of the literature in regards to the diagnostic yields of vitreous specimens obtained via 25-gauge and 20-gauge diagnostic vitrectomy in suspected cases of IOL was performed.RESULTS:Eighteen eyes from 12 patients with clinical suspicion of IOL underwent diagnostic 25G-TSV.The cytopathological investigations demonstrated IOL in 15eyes(83.3%).Vitreous analysis was non-diagnostic in 3eyes(16.7%).CONCLUSION:Twenty-five-gauge diagnostic vitrectomy yields adequate sample for cytological evaluation of the vitreous in cases suspicious for IOL.The diagnostic results of the 25G-TSV in the current study are superior to those reported for 20-gauge vitrectomy but equivalent to those reported for 25G-TSV in the published literature.
文摘The energy absorption capacity of the Al5083 thin-walled tube produced by parallel tubular angular pressing(PTCAP) process was evaluated. Also, microstructure, mechanical properties, and anisotropy coefficients were studied in the peripheral and axial directions. Results showed that values of energy absorption decreased with processing pass increasing and the values for the unprocessed, first and second passes were obtained to be 167, 161.4 and 160.7 J, respectively. The differences between the simulation results for the energy absorption values and their experimental values for the unprocessed, the first and the second PTCAP passes samples are about 5%, 10%, and 13%, respectively. The energy absorption capacity was related to the anisotropy coefficient and microstructure. The results demonstrated that grain refinement occurred and ultimate tensile strength(UTS) and microhardness after the first and second PTCAP passes were enhanced, while the increase rate in the first pass was much severer. Also, by applying PTCAP, the deformation modes were altered, such that the deformation mode of the annealed tube was quite symmetrical and circular while for the first and second passes there have been triple and double lobes diamond. The results of the numerical simulation for the deformation mode of the annealed and PTCAPed tubes were consistent with the experimental results. The deformation mode of tubes is dependent on their mechanical properties and variation of the mechanical properties during PTCAP process.
基金Supported by The Mazandaran University of Medical Sciences,No. 88-512
文摘AIM： To investigate the association of the inducible ni- tric oxide synthetase （iNOS） C150T polymorphism with Helicobacter pylori （H. pylor/） infection and gastric can- cer （GC） risk in Iran. METHODS： In order to determine whether there was a correlation between iNOS genotype and GC in Iran, we conducted a case-control study using samples from 329 individuals. For each sample, the C150T ilVOS poly- morphism was genotyped by polymerase chain reaction （PCR） and restriction digestion. Patients were grouped by cancer presence, demographic and behavior charac- teristics, and/-/, pylori infection status. Statistical tests were conducted to determine whether any behavioral factors or a particular iNOS genotype was associated with GC in the study population. RESULTS： In this population, we found that smok- ing, hot beverage consumption, a familial history of GC and H. pylori infection status were significantly associated with GC development （P = 0.015, P 〈 0.001, P = 0.0034, and P 〈 0.015, respectively）. The distribution of the C150T ilVOS genotypes among the two study groups was not statistically significant alone, but was impacted by H. pylori infection status. When compared to the non-/-/, pylori infected group, cancer patients who had a heterozygous CT genotype and were also infected with H. pylori were 2.1 times more at risk of developing GC [odds ratio （OR） = 2.1, P = 0.03] while those with a homozygous TT genotype and infected with H. pylori were 5.0 times more at risk of developing GC （OR = 5.0, P = 0.029）. In contrast, this association was not seen in patients in the control group.CONCLUSION： ACT or TT polymorphism at position 150 in the iNO$ gene significantly increases the risk of GC and may be a marker for GC susceptibility.
