The microstructural evolution of pearlite during severe cold rolling in Fe-0.8C binary alloy and Fe-1Mn-0.8C ternary alloys was investigated by using SEM, TEM and XRD etc. The results show that the deformed pearlite c...The microstructural evolution of pearlite during severe cold rolling in Fe-0.8C binary alloy and Fe-1Mn-0.8C ternary alloys was investigated by using SEM, TEM and XRD etc. The results show that the deformed pearlite consists of irregularly bent lamella, coarse lamella with shear-band and fine lamella. As the rolling reduction increases, the proportion of fine lamella increases. The strong plastic deformation, amorphization and dissolution of cementite take place during the severe cold rolling. The maximum carbon content in ferrite reaches 0.15 mass% after 90% cold rolling.展开更多
Objective To investigate the relation of methionine synthase (MS) gene variation with congenital heart disease (CHD) phenotype. Methods One hundred and ninety three CHD patients (94 males and 99 females) and their bio...Objective To investigate the relation of methionine synthase (MS) gene variation with congenital heart disease (CHD) phenotype. Methods One hundred and ninety three CHD patients (94 males and 99 females) and their biological parents (nuclear families) in Liaoning Province were selected as the case group, and another 104 normal persons (60 males and 44 females) and their parents without family history of birth defects as the control group. For all subjects the polymorphism of MS gene A2756G locus was examined by PCR-RFLP method. Results In offspring of the control group the frequencies of MS genotype (+/ -) and allele (+) were 10.7% and 5.3%, without existence of homozygote. The MS genotype distribution and allele frequencies of CHD patients and their mothers were not significantly different from the control (P > 0.05). The frequency of allele (+) in case fathers (5.0 %) was apparently lower than that in the control (9.1%, P=0.060), and the odds ratio (OR) was 0.53 (95% CI: 0.25-1.09). There was no difference in parents' genotype combination between the two groups, and in genotype distribution among different types of CHD. Analysis of genetic transmission indicated that mutation allele (+) existed transmission disequilibrium in CHD nuclear families. The percentage of allele (+) transmitted from parents was lower than that allele (-) with OR 0.26 (95% CI: 0.11-0.60). Conclusion MS gene variation in parents is associated with occurrence of CHD in offspring, and mutation allele (+) in parents may be related with the decrease of CHD risk in offspring.展开更多
To investigate the relationship between G1958A gene polymorphism of methylenetetrahydrofolate dehydrogenase (MTHFD) and occurrence of congenital heart disease (CHD) in North China. Methods One hundred and ninety-two...To investigate the relationship between G1958A gene polymorphism of methylenetetrahydrofolate dehydrogenase (MTHFD) and occurrence of congenital heart disease (CHD) in North China. Methods One hundred and ninety-two CHD patients and their parents were included in this study as case group in Liaoning Province by birth defect registration cards, and 124 healthy subjects (age and gender matched) and their parents were simultaneously selected from the same geographic area as control. Their gene polymorphism of MTHFD G1958A locus was examined with PCR-RFLP, and serum folic acid and homocysteine (Hcy) levels were tested with radio-immunoassay and fluorescence polarization immunoassay (FPIA). Results There existed gene polymorphism at MTHFD G1958A locus in healthy subjects living in North China. The percentages of GG, GA, and AA genotype were 57.98%, 35.57%, and 6.45% respectively, and the A allele frequency was 24.23%, which was significantly different from Western population. No difference was observed when comparing genotype distribution and allele frequency between the case and control groups, so was the result from the comparison between genders. The A allele frequency of arterial septal defect patients’ mothers (10.87%) was significantly lower than that of controls (28.15%) (P=0.014), with OR=0.31 (95% CI: 0.09-0.84), and no difference in the other subgroups. The percentage of at least one parent carrying A allele in arterial septal defect subgroup (43.48%) was significantly lower than that in controls (69.64%) (P=0.017), with OR=0.34 (95% CI: 0.12-0.92). The analysis of genetic transmission indicated that there was no transmission disequillibrium in CHD nuclear families. Their serum folic acid level was significantly higher than that of controls (P=0.000), and Hcy level of the former was higher than that of the latter with no statistical significance (P>0.05). Serum Hcy and folic acid levels of mothers with gene mutation were lower than those of mothers with no mutation. Conclusion No significant difference of genotype distribution and allele frequency existed between CHD patients and healthy population. MTHFD G1958A mutation in parents (particularly in mother) can decrease the risk of arterial septal defect in offspring. The possible mechanism of protection might be mutation, which can increase MTHFD enzyme activity, folic acid metabolism and homocysteine remethylation, and decrease Hcy level.展开更多
AIM:Modified Heller's myotomy is still the first choice for achalasia and the assessment of surgical outcomes is usually made based on the subjective sensation of patients.This study was to objectively assess the ...AIM:Modified Heller's myotomy is still the first choice for achalasia and the assessment of surgical outcomes is usually made based on the subjective sensation of patients.This study was to objectively assess the long-term outcomes of esophageal myotomy for achalasia using esophageal manometry, 24-hour pH monitoring,esophageal scintigraphy and fiberoptic esophagoscopy.METHODS:From February 1979 to October 2000, 176 patients with achalasia underwent modified Heller's myotomy, including esophageal myotomy alone in 146 patients, myotomy in combination with Gallone or Dor antirefiux procedure in 22 and 8 patients, respectively. Clinical score,pressure of the lower esophageal sphincter (LES),esophageal clearance rate and gastroesophageal reflux were determined before and i to 22 years after surgery.RESULTS: After a median follow-up of 14 years, 84.5% of patients had a good or excellent relief of symptoms,and clinical scores as well as resting pressures of the esophageal body and LES were reduced compared with preoperative values (P<0.001).However,there was no significant difference in DeMeester score between pre-and postoperative patients(P=0.51).Esophageal transit was improved in postoperative patients, but still slower than that in normal controls. The incidence of gastroesophageal reflux in patients who underwent esophageal myotomy alone was 63.6% compared to 27.3% in those who underwent myotomy and antirefiux procedure (P=-0.087). Three (1.7%) patients were complicated with esophageal cancer after surgery.CONCLUSION: Esophageal myotomy for achalasia can reduce the resting pressures of the esophageal body and LES and improve esophageal transit and dysphagia. Myotomy in combination with antireflux procedure can prevent gastroesophageal reflux to a certain extent,but further randomized studies should be carried out to demonstrate its efficacy.展开更多
AIM: To investigate the uptake of 99mTc-HYNIC-Tyr3-octreotide (99mTc-HYNIC-TOC) in human hepatocellular carcinoma (HCC), which can provide the localizable diagnosis in hepatic carcinoma. METHODS: The expression of som...AIM: To investigate the uptake of 99mTc-HYNIC-Tyr3-octreotide (99mTc-HYNIC-TOC) in human hepatocellular carcinoma (HCC), which can provide the localizable diagnosis in hepatic carcinoma. METHODS: The expression of somatostatin receptor 2 (SSTR2) messenger RNA (mRNA) in human HCC cell line HepG2 was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). Uptake of 99mTc-HYNIC-TOC was evaluated in the human HCC implanted into BALB/c nude mice. ANMIS2000 nuclear medicine analysis system was used to calculate the ratio of 99mTc uptake between tumor tissue and vital organs. RESULTS: We demonstrated the expression of SSTR2 mRNA in human HCC cell line HepG2 by RT-PCR. The size of the RT-PCR products was 364 bp detected by sequence analysis of the human SSTR2 mRNA. Scintigraphy proved that 99mTc-HYNIC-TOC was uptaken in the tumor tissue, liver and kidney of the tumor-bearing mice. CONCLUSION: Based on expression of the SSTR2 mRNA in human HCC, 99mTc-HYNIC-TOC can markedly bind with and be uptaken by human HCC tissues as compared with normal liver tissue. The significant retention of radionudide in kidney and bladder is probably related to non-specific peptide uptake in the tubulus cells of kidney and possibly due to excretion by kidney. Our results show that localizable diagnosis and targeting radiotherapy with radionuclide-labeled somatostatin analog for HCC are of great value to be further studied.展开更多
To examine the effect of community-based dietary intervention on hyperlipidemia. Methods A total of 180 hyperlipidemia individuals with TG>2.26 mmol稬-1(200 mg穌L-1)and/or TC>5.72 mmol稬-1 (220 mg穌L-1) were ...To examine the effect of community-based dietary intervention on hyperlipidemia. Methods A total of 180 hyperlipidemia individuals with TG>2.26 mmol稬-1(200 mg穌L-1)and/or TC>5.72 mmol稬-1 (220 mg穌L-1) were selected from 428 eligible subjects in eight communities of Beijing. They were randomly divided into intervention group (n=108) and control group (n=72). Dietary intervention was provided for the intervention group for 6 months. Information on dietary intakes, physical examinations and blood samples was collected. Serum lipids were assayed at baseline and endpoint of the study period. Results Respective decrease in dietary intake of total calories, fat, cholesterol and cooking oil by 13.62%, 24.75%, 24.40%, and 22.43%, in the intervention group was observed. The percentages of total calories from fat, carbohydrate and protein appeared to be desirable after study. Reduced body weight and BMI were also observed. There was a respective 5.61% and 7.06 % decrease in total serum cholesterol and low-density lipoprotein cholesterol in the intervention group, while no significant changes were found in the control group. Conclusions Community-based dietary intervention can effectively improve dietary patterns, control body weight, and decrease the levels of total serum cholesterol and low-density lipoprotein cholesterol.展开更多
Pilot biomechanical design of biomaterials for artificial nucleus prosthesiswas carried out based on the 3D finite-element method. Two 3D models of lumbar intervertebral discrespectively with a real human nucleus and ...Pilot biomechanical design of biomaterials for artificial nucleus prosthesiswas carried out based on the 3D finite-element method. Two 3D models of lumbar intervertebral discrespectively with a real human nucleus and with the nucleus removed were developed and validatedusing published experimental and clinical data. Then the models with a stainless steel nucleusprosthesis implanted and with polymer nucleus prostheses of various properties implanted were usedfor the 3D finite-element biomechanical analysis. All the above simulation and analysis were carriedout for the L4/L5 disc under a human worst--daily compression load of 2000 N. The results show thatthe polymer materials with Young's modulus of elasticity E = 0.1-100 MPa and Poisson's ratio v=0.35-0.5 are suitable to produce artificial nucleus prosthesis in view of biomechanicalconsideration.展开更多
Journal evaluation is a compliated engineering system, how to evaluate academic journals more scientifically in scientific methods have becomes a problem of great concerns. This paper presents attribute mathematical m...Journal evaluation is a compliated engineering system, how to evaluate academic journals more scientifically in scientific methods have becomes a problem of great concerns. This paper presents attribute mathematical model for comprehensive index system' quality evaluation for natural science academic journals, aiming to make comprehensive index system' quality evaluation for academic journals more objective and reasonable compared with other quantitative evaluation ways.展开更多
基金The financial support of the Iron and Alloy Institute of Japan is gratefully acknowledged.One of the authors(Wantang Fu)appreciates the support from the National Natural Science Foundation of China(No.50271061).
文摘The microstructural evolution of pearlite during severe cold rolling in Fe-0.8C binary alloy and Fe-1Mn-0.8C ternary alloys was investigated by using SEM, TEM and XRD etc. The results show that the deformed pearlite consists of irregularly bent lamella, coarse lamella with shear-band and fine lamella. As the rolling reduction increases, the proportion of fine lamella increases. The strong plastic deformation, amorphization and dissolution of cementite take place during the severe cold rolling. The maximum carbon content in ferrite reaches 0.15 mass% after 90% cold rolling.
基金This work was supported by the Major State Basic Research Development Program of People's Republic of China (G1999055904) the Danone's Diet and Nutrition Research and Education Grant (DIC2002-08).
文摘Objective To investigate the relation of methionine synthase (MS) gene variation with congenital heart disease (CHD) phenotype. Methods One hundred and ninety three CHD patients (94 males and 99 females) and their biological parents (nuclear families) in Liaoning Province were selected as the case group, and another 104 normal persons (60 males and 44 females) and their parents without family history of birth defects as the control group. For all subjects the polymorphism of MS gene A2756G locus was examined by PCR-RFLP method. Results In offspring of the control group the frequencies of MS genotype (+/ -) and allele (+) were 10.7% and 5.3%, without existence of homozygote. The MS genotype distribution and allele frequencies of CHD patients and their mothers were not significantly different from the control (P > 0.05). The frequency of allele (+) in case fathers (5.0 %) was apparently lower than that in the control (9.1%, P=0.060), and the odds ratio (OR) was 0.53 (95% CI: 0.25-1.09). There was no difference in parents' genotype combination between the two groups, and in genotype distribution among different types of CHD. Analysis of genetic transmission indicated that mutation allele (+) existed transmission disequilibrium in CHD nuclear families. The percentage of allele (+) transmitted from parents was lower than that allele (-) with OR 0.26 (95% CI: 0.11-0.60). Conclusion MS gene variation in parents is associated with occurrence of CHD in offspring, and mutation allele (+) in parents may be related with the decrease of CHD risk in offspring.
基金This work was supported by the Major State Basic Research Development Program of People’s Republic of China (G1999055904)and the Danone’s Diet and Nutrition Research and Education Grant (DIC2002-08).
文摘To investigate the relationship between G1958A gene polymorphism of methylenetetrahydrofolate dehydrogenase (MTHFD) and occurrence of congenital heart disease (CHD) in North China. Methods One hundred and ninety-two CHD patients and their parents were included in this study as case group in Liaoning Province by birth defect registration cards, and 124 healthy subjects (age and gender matched) and their parents were simultaneously selected from the same geographic area as control. Their gene polymorphism of MTHFD G1958A locus was examined with PCR-RFLP, and serum folic acid and homocysteine (Hcy) levels were tested with radio-immunoassay and fluorescence polarization immunoassay (FPIA). Results There existed gene polymorphism at MTHFD G1958A locus in healthy subjects living in North China. The percentages of GG, GA, and AA genotype were 57.98%, 35.57%, and 6.45% respectively, and the A allele frequency was 24.23%, which was significantly different from Western population. No difference was observed when comparing genotype distribution and allele frequency between the case and control groups, so was the result from the comparison between genders. The A allele frequency of arterial septal defect patients’ mothers (10.87%) was significantly lower than that of controls (28.15%) (P=0.014), with OR=0.31 (95% CI: 0.09-0.84), and no difference in the other subgroups. The percentage of at least one parent carrying A allele in arterial septal defect subgroup (43.48%) was significantly lower than that in controls (69.64%) (P=0.017), with OR=0.34 (95% CI: 0.12-0.92). The analysis of genetic transmission indicated that there was no transmission disequillibrium in CHD nuclear families. Their serum folic acid level was significantly higher than that of controls (P=0.000), and Hcy level of the former was higher than that of the latter with no statistical significance (P>0.05). Serum Hcy and folic acid levels of mothers with gene mutation were lower than those of mothers with no mutation. Conclusion No significant difference of genotype distribution and allele frequency existed between CHD patients and healthy population. MTHFD G1958A mutation in parents (particularly in mother) can decrease the risk of arterial septal defect in offspring. The possible mechanism of protection might be mutation, which can increase MTHFD enzyme activity, folic acid metabolism and homocysteine remethylation, and decrease Hcy level.
文摘AIM:Modified Heller's myotomy is still the first choice for achalasia and the assessment of surgical outcomes is usually made based on the subjective sensation of patients.This study was to objectively assess the long-term outcomes of esophageal myotomy for achalasia using esophageal manometry, 24-hour pH monitoring,esophageal scintigraphy and fiberoptic esophagoscopy.METHODS:From February 1979 to October 2000, 176 patients with achalasia underwent modified Heller's myotomy, including esophageal myotomy alone in 146 patients, myotomy in combination with Gallone or Dor antirefiux procedure in 22 and 8 patients, respectively. Clinical score,pressure of the lower esophageal sphincter (LES),esophageal clearance rate and gastroesophageal reflux were determined before and i to 22 years after surgery.RESULTS: After a median follow-up of 14 years, 84.5% of patients had a good or excellent relief of symptoms,and clinical scores as well as resting pressures of the esophageal body and LES were reduced compared with preoperative values (P<0.001).However,there was no significant difference in DeMeester score between pre-and postoperative patients(P=0.51).Esophageal transit was improved in postoperative patients, but still slower than that in normal controls. The incidence of gastroesophageal reflux in patients who underwent esophageal myotomy alone was 63.6% compared to 27.3% in those who underwent myotomy and antirefiux procedure (P=-0.087). Three (1.7%) patients were complicated with esophageal cancer after surgery.CONCLUSION: Esophageal myotomy for achalasia can reduce the resting pressures of the esophageal body and LES and improve esophageal transit and dysphagia. Myotomy in combination with antireflux procedure can prevent gastroesophageal reflux to a certain extent,but further randomized studies should be carried out to demonstrate its efficacy.
文摘AIM: To investigate the uptake of 99mTc-HYNIC-Tyr3-octreotide (99mTc-HYNIC-TOC) in human hepatocellular carcinoma (HCC), which can provide the localizable diagnosis in hepatic carcinoma. METHODS: The expression of somatostatin receptor 2 (SSTR2) messenger RNA (mRNA) in human HCC cell line HepG2 was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). Uptake of 99mTc-HYNIC-TOC was evaluated in the human HCC implanted into BALB/c nude mice. ANMIS2000 nuclear medicine analysis system was used to calculate the ratio of 99mTc uptake between tumor tissue and vital organs. RESULTS: We demonstrated the expression of SSTR2 mRNA in human HCC cell line HepG2 by RT-PCR. The size of the RT-PCR products was 364 bp detected by sequence analysis of the human SSTR2 mRNA. Scintigraphy proved that 99mTc-HYNIC-TOC was uptaken in the tumor tissue, liver and kidney of the tumor-bearing mice. CONCLUSION: Based on expression of the SSTR2 mRNA in human HCC, 99mTc-HYNIC-TOC can markedly bind with and be uptaken by human HCC tissues as compared with normal liver tissue. The significant retention of radionudide in kidney and bladder is probably related to non-specific peptide uptake in the tubulus cells of kidney and possibly due to excretion by kidney. Our results show that localizable diagnosis and targeting radiotherapy with radionuclide-labeled somatostatin analog for HCC are of great value to be further studied.
基金Danone Institute Grant for Nutrition Research and Education Projects China 2000.
文摘To examine the effect of community-based dietary intervention on hyperlipidemia. Methods A total of 180 hyperlipidemia individuals with TG>2.26 mmol稬-1(200 mg穌L-1)and/or TC>5.72 mmol稬-1 (220 mg穌L-1) were selected from 428 eligible subjects in eight communities of Beijing. They were randomly divided into intervention group (n=108) and control group (n=72). Dietary intervention was provided for the intervention group for 6 months. Information on dietary intakes, physical examinations and blood samples was collected. Serum lipids were assayed at baseline and endpoint of the study period. Results Respective decrease in dietary intake of total calories, fat, cholesterol and cooking oil by 13.62%, 24.75%, 24.40%, and 22.43%, in the intervention group was observed. The percentages of total calories from fat, carbohydrate and protein appeared to be desirable after study. Reduced body weight and BMI were also observed. There was a respective 5.61% and 7.06 % decrease in total serum cholesterol and low-density lipoprotein cholesterol in the intervention group, while no significant changes were found in the control group. Conclusions Community-based dietary intervention can effectively improve dietary patterns, control body weight, and decrease the levels of total serum cholesterol and low-density lipoprotein cholesterol.
文摘Pilot biomechanical design of biomaterials for artificial nucleus prosthesiswas carried out based on the 3D finite-element method. Two 3D models of lumbar intervertebral discrespectively with a real human nucleus and with the nucleus removed were developed and validatedusing published experimental and clinical data. Then the models with a stainless steel nucleusprosthesis implanted and with polymer nucleus prostheses of various properties implanted were usedfor the 3D finite-element biomechanical analysis. All the above simulation and analysis were carriedout for the L4/L5 disc under a human worst--daily compression load of 2000 N. The results show thatthe polymer materials with Young's modulus of elasticity E = 0.1-100 MPa and Poisson's ratio v=0.35-0.5 are suitable to produce artificial nucleus prosthesis in view of biomechanicalconsideration.
文摘Journal evaluation is a compliated engineering system, how to evaluate academic journals more scientifically in scientific methods have becomes a problem of great concerns. This paper presents attribute mathematical model for comprehensive index system' quality evaluation for natural science academic journals, aiming to make comprehensive index system' quality evaluation for academic journals more objective and reasonable compared with other quantitative evaluation ways.
