AIM: To investigate the expression of NGF family and their receptors in gastric carcinoma and normal gastric mucosa,and to elucidate their effects on gastric carcinoma.METHODS: RNA of gastric cancer tissues and normal...AIM: To investigate the expression of NGF family and their receptors in gastric carcinoma and normal gastric mucosa,and to elucidate their effects on gastric carcinoma.METHODS: RNA of gastric cancer tissues and normal gastric tissues was respectively isolated and mRNA was purified.Probes of both mRNA reverse transcription product cDNAs labled with α-33P dATP were respectively hybridized with Atlas Array membrane where NGF and their family genes were spotted on. Hybridized signal images were scanned on phosphor screen with ImageQuant 5.1 software after hybridization. Normalized values on spots were analyzed with ArrayVersion 5.0 software. Differential expression of NGF family and their receptors mRNA was confirmed between hybridized Atlas Array membranes of gastric cancer tissues and normal gastric mucosa, then their effects on gastric carcinoma were investigated.RESULTS: Hybridization signal images on Atlas Array membrane appeared in a lower level of nonspecific hybridization. Both of NGF family and their receptors Trk family mRNA were expressed in gastric cancer and normal gastric mucosa. But adversely up-regulated expression in other tissues and organs. NGF, BDGF, NT-3, NT-4/5, NT-6and TrkA, B and C were down-regulated simultaneously in gastric carcinoma in comparison with normal gastric mucosa. Degrees of down-regulation in NGF family were greater than those in their receptors Trk family. Downregulation of NT-3 and BDGF was the most significant,and TrkC down-regulation level was the lowest in receptors Trk family.CONCLUSION: Down-regulated expression of NGF family and their receptors Trk family mRNA in gastric cancer is confirmed. NGF family and their receptors Trk family probably play a unique role in gastric cancer cell apoptosis by a novel Ras or Raf signal transduction pathway. Their synchronous effects are closely associated with occurrence and development of gastric carcinoma induced by reduction of signal transduction of programmed cell death.展开更多
AIM: To study the value of monitoring K-ras point mutation at codon 12 and telomerase activity in exfoliated cells obtained from pancreatic duct brushings during endoscopic retrograde cholangiopancreatography (ERCP) i...AIM: To study the value of monitoring K-ras point mutation at codon 12 and telomerase activity in exfoliated cells obtained from pancreatic duct brushings during endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic cancer.METHODS: Exfoliated cells obtained from pancreatic duct brushings during ERCP were examined in 27 patients: 23 with pancreatic cancers, 4 with chronic pancreatitis. K-ras point mutation was detected with the polymerase chain reaction and restriction fragment-length polymorphism(PCR-RFLP). Telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA).RESULTS: The telomerase activities in 27 patients were measured in 21 exfoliated cell samples obtained from pancreatic duct brushings. D450 value of telomerase activities in pancreatic cancer and chronic pancreatitis were 0.446+0.27 and 0.041+0.0111, respectively. Seventy-seven point eight percent (14/18) of patients with pancreatic cancer and none of the patients with chronic pancreatitis showed telomerase activity in cells collected from pancreatic duct brushings when cutoff value of telomerase activity was set at 2.0. The K-ras gene mutation rate (72.2%) in pancreatic cancer was higher than that in chronic pancreatitis (33.3%) (P<0.05). In considering of both telomerase activities and K-ras point mutation, the total positive rate was 83.3% (15/18), and the specificity was 100%.CONCLUSION: Changes of telomerase activities and K-ras point mutation at codon 12 may be an early event of malignant progression in pancreatic cancer. Detection of telomerase activity and K-ras point mutation at codon 12 may be complementary to each other, and is useful in diagnosis of pancreatic cancer.展开更多
An efficient method is developed to investigate the vibration and stability of moving plates immersed in fluid by applying the Kirchhoff plate theory and finite element method.The fluid is considered as an ideal fluid...An efficient method is developed to investigate the vibration and stability of moving plates immersed in fluid by applying the Kirchhoff plate theory and finite element method.The fluid is considered as an ideal fluid and is described with Bernoulli’s equation and the linear potential flow theory.Hamilton’s principle is used to acquire the dynamic equations of the immersed moving plate.The mass matrix,stiffness matrix,and gyroscopic inertia matrix are determined by the exact analytical integration.The numerical results show that the fundamental natural frequency of the submersed moving plates gradually decreases to zero with an increase in the axial speed,and consequently,the coupling phenomenon occurs between the first-and second-order modes.It is also found that the natural frequency of the submersed moving plates reduces with an increase in the fluid density or the immersion level.Moreover,the natural frequency will drop obviously if the plate is located near the rigid wall.In addition,the developed method has been verified in comparison with available results for special cases.展开更多
Extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydro- chloride (PCN) in the system described in the title was studied. Research shows that the extraction efficiency of CPZ can amount to 96% by...Extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydro- chloride (PCN) in the system described in the title was studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, while that of PCN is 77%. This system produces the distribution coefficients (KD) of 12.3 and 2.6 respectively for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet and molecular fluorescence spectra variation of the drugs in the system studied.展开更多
A 3D structured composite of carbon nanofibers @ MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofibe...A 3D structured composite of carbon nanofibers @ MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofiber yarns were synthesized directly over copper foil through a floating catalyst method. The growth of carbon nanofiber yarns was significantly enhanced by mechanical polishing of the copper foils, which can be attributed to the increased surface roughness and surface area of the copper foils. MnO2 was then grown over carbon nanofibers through spontaneous reduction of potassium permanganate by the carbon nanofibers. The obtained composites of carbon nanofibers@MnO2 over copper foil were tested as an anode in lithium ion batteries and they show superior electrochemical performance. The initial reversible capacity of carbon nanofibers@MnO2 reaches up to around 998 mAh.g-1 at a rate of 60 mmA.g-l based on the mass of carbon nanofibers and MnO2. The carbon nanofibers @ MnO2 electrodes could deliver a capacity of 630 mAh.g-1 at the beginning and maintain a capacity of 440 mmAh.g-1 after 105 cycles at a rate of 600 mA.g-~. The high initial capacity can be attributed to the presence of porous carbon nanofiber yarns which have good electrical conductivity and the MnO2 thin film which makes the entire materials electrochemically active. The high cyclic stability of carbon nanofibers@MnO2 can be ascribed to the MnO2 thin film which can accommodate the volume expansion and shrinking during charge and discharge and the good contact of carbon nanofibers with MnO2 and copper foil.展开更多
Electrochemical energy storage systems with high specific energy and power as well as long cyclic stability attract increasing attention in new energy technologies. The principles for rational design of electrodes are...Electrochemical energy storage systems with high specific energy and power as well as long cyclic stability attract increasing attention in new energy technologies. The principles for rational design of electrodes are discussed to reduce the activation, concentration, and resistance overpotentials and improve the active ma- terial efficiency in order to simultaneously achieve high specific energy and power. Three dimensional （3D） nanocomposites are currently considered as promising electrode materials due to their large surface area, reduced electronic and ionic diffusion distances, and synergistic effects. This paper reviews the most recent progress on the synthesis and application of 3D thin film nanoelectrode arrays based on aligned carbon nan- otubes （ACNTs） directly grown on metal foils for energy storages and special attentions are paid on our own representative works. These novel 3D nanoelectrode arrays on metal foil exhibit improved electrochemical performances in terms of specific energy, specific power and cyclic stability due to their unique structures. In this active materials coated ACNTs over conductive substrate structures, each component is tailored to address a different demand. The electrochemical active material is used to store energy, while the ACNTs are employed to provide a large surface area to support the active material and nanocable arrays to facilitate the electron transport. The thin film of active materials can not only reduce ion transport resistance by shorten- ing the diffusion length but also make the film elastic enough to tolerate significant volume changes during charge and discharge cycles. The conductive substrate is used as the current collector and the direct contact of the ACNT arrays with the substrate reduces significantly the contact resistance. The principles obtained from ACNT based electrodes are extended to aligned graphene based electrodes. Similar improvements have been achieved which confirms the reliability of the principles obtained. In addition, we al展开更多
To analyze the hazard factors for the constructors through the geographic environment along the Qinghai-Tibetan railway. On the basis of the physical examination data of the constructors, we dynamically investigated t...To analyze the hazard factors for the constructors through the geographic environment along the Qinghai-Tibetan railway. On the basis of the physical examination data of the constructors, we dynamically investigated the impact of the plateau environment on the constructors’ health. We concluded the adaptation after the plain people entering into the plateau, and the application of the medical security measures and the effectiveness of the Plateau diseases preventing and controlling measures during the construction of the Qinghai-Tibetan railway. The results showed that there existed many occupational hazard factors because of the harsh environment in the Qinghai-Tibetan plateau, and they did a severe harm to the constructors. To take an effective prevention measure could apparently alleviate the occupational hazards, and ensure the safety and health of the constructors. The paper not only provided the valuable experiences for the medical support during the economic construction in the Qinghai-Tibetan plateau areas in the future, but also made a contribution for improving the development of the world plateau medicine.展开更多
Objective To confirmed reliability and feasibility of intranasal nerve growth factor (NGF) bypassing the blood-brain barrier and its potential neuroprotective effects on acute cerebral ischemia. Methods (1) To assay N...Objective To confirmed reliability and feasibility of intranasal nerve growth factor (NGF) bypassing the blood-brain barrier and its potential neuroprotective effects on acute cerebral ischemia. Methods (1) To assay NGF concentrations in different brain regions after middle cerebral artery occlusion (MCAO).Rats were randomly divided into intranasal (IN) NGF, intravenous (IV) NGF, and untreated group (n= 4). The concentra-tions of NGF of different brain regions in the three groups after MCAO were measured by ELISA. (2) To observe neuro-protective action of NGF on focal cerebral ischemic damage. Rats were randomly assigned to 4 groups: IN vehicle, IN NGF, IV vehicle, IV NGF (n= 8). Treatment was initiated 30 minutes after onset of MCAO and given again 24 hours later. Three neurologic behavioral tests were performed 24 and 48 hours following onset of MCAO. Corrected infarct volumes were determined 48 hours after onset of MCAO. Results The olfactory bulb in IN NGF group obtained the highest concentration (3252 pg/g) of NGF among all regions, followed by the hippocampus. The NGF concentrations in the olfactory bulb and hippocampus in IN NGF group were markedly higher than that in IV NGF and control groups. The infarct volume in IN NGF group was markedly reduced by 38.8% compared with IN vehicle group. IN NGF group vestibulum function markedly improved compared with IN vehicle group at 24 and 48 hours after onset of MCAO (P 24 h = 0.02 and P 48 h = 0.04, respectively). Conclusion Intranasal NGF could pass through the blood-brain barrier, reach the central nervous system, reduce infarct volume, and improve neurologic function in rats following MCAO. Intranasal delivery of NGF may be a promising treat-ment for stroke.展开更多
Objective To estimate the frequency of various risk factors for overall stroke and to identify risk factors for cerebral infarction (CI) versus intracerebral hemorrhage (ICH) in a large hospital-based stroke registry....Objective To estimate the frequency of various risk factors for overall stroke and to identify risk factors for cerebral infarction (CI) versus intracerebral hemorrhage (ICH) in a large hospital-based stroke registry. Methods Data from a total of 3901 patients, consisting of 3525 patients with CI and 376 patients with ICH were pros-pectively coded and entered into a computerized data bank. Results Hypertension and smoking were the most prominent factors affecting overall stroke followed by mild internal carotid artery stenosis (< 50%), hypercholesterolemia, transient ischemic attacks (TIAs), diabetes mellitus, and cardiac ischemia. Univariate analysis showed that factors in male significantly associated with CI versus ICH were old age, a family history of stroke, and intermittent claudication; whereas in female the factors were oral contraception and migraine. By multivariate analysis, in all patients, the factors significantly associated with CI as opposed to ICH were smoking, hyperch-olesterolemia, migraine, TIAs, atrial fibrillation, structural heart disease, and arterial disease. Hypertension was the only significant factor related with ICH versus CI.Conclusions The factors for ischemic and hemorrhagic stroke are not exactly the same. Cardiac and arterial disease are the most powerful factors associated with CI rather than ICH.展开更多
Objective To investigate the relationship between vascular endothelial dysfunction and serum homocysteine (HCY) level in patients with coronary lesions. Methods Serum HCY, serum nitric oxide (NO), plasma endothelin-1 ...Objective To investigate the relationship between vascular endothelial dysfunction and serum homocysteine (HCY) level in patients with coronary lesions. Methods Serum HCY, serum nitric oxide (NO), plasma endothelin-1 (ET-1), and circulation endothelial cell (CEC) were measured in 76 patients who received coronary angiography. Fifty-four patients with a stenosis of 50% or more at least in one coronary atery were as coronary artery disease (CAD) group. Other 22 cases with no recognizable plaque and/or stenosis were as control group. HCY level was detected using an enzyme immunoassay kit. NO concentration was measured using a nitrate reductase kit. Radio-immunoassay was applied to analyse the ET-1 level, and CEC was measured by flow cytometry. Results The levels of HCY, ET-1, and CEC in patients with coronary lesions were significantly increased in comparison with control group (P < 0.01), while NO level in CAD group was significantly lower compared with that in control (P < 0.01). Using a multivariate stepwise regression analysis, HCY level had a positive correlation with ET-1 level (r = 0.420, P < 0.05) and CECs number (r = 0.423, P < 0.05); and had a negative correlation with NO/ET-1 (r = -0.403, P < 0.05). But there was no significant correlation between HCY and NO levels. Conclusions HCY might lead to endothelial cell injury, which would provide a plausible mechanism for the relationship between hyperhomocysteinemia and development of coronary artery disease. HCY can be considered as a predictor for preli-minary or active coronary lesion.展开更多
In this paper, we consider the blow-up of smooth solutions to the 3D ideal MHD equations. Let (u, b) be a smooth solution in (0, T). It is proved that the solution (u, b) can be extended after t = T if . This is an i...In this paper, we consider the blow-up of smooth solutions to the 3D ideal MHD equations. Let (u, b) be a smooth solution in (0, T). It is proved that the solution (u, b) can be extended after t = T if . This is an improvement of the result given by Caflisch, Klapper, and Steele [3].展开更多
AIM:To investigate the effect of Helicobacter pylori (H pylon)infection on the expressions of Bcl-2 family members in gastric adenocarcinoma.METHODS:Gastric adenocarcinoma and resection margin tissues of 95 patients w...AIM:To investigate the effect of Helicobacter pylori (H pylon)infection on the expressions of Bcl-2 family members in gastric adenocarcinoma.METHODS:Gastric adenocarcinoma and resection margin tissues of 95 patients were studied.Semi-quantitative RT-PCR was used to measure Bid, Bax and Bcl-2 mRNA expressions.RESULTS:Expressions of Bid and Bax in gastric adenocarcinoma tissues without H pyloriinfection,with cagA^- H pyloriinfection and cagA^+ H pyloriinfection increased significantly in turn (Bid,0.304,0.422 and 0.855 respectively, P<0.05, Bax,0.309,0.650 and 0.979 respectively, P<0.05). Bcl-2 mRNA levels increased significantly in gastric adenocarcinoma tissues with cagA^- H pylori infection and cagA^+ H pylori infection,compared with those without H pyloriin fection(0.696 and 0.849 vs0.411, P<0.05).Expressions of Bid,Bax and Bcl-2 in resection margin tissues without Hpylori infection,with cagA^- H pylori infection and cagA^+ H pylori infection increased significantly in turn (Bid, 0.377, 0.686 and 0.939 respectively, P<0.05, Bax,0.353,0.645 and 1.001 respectively,P<0.05,Bcl-2,0.371,0.487 and 0.619 respectively,P<0.05).In H pylori negative specimens,expressions of Bid and Bax correlated negatively with that of Bcl-2 respectively in adenocarcinoma tissues (Bid vs Bcl-2, r=-0.409, P<0.05,Bax vs Bcl-2,r=-0.451, P<0.05).In H pylori positive specimens,expressions of Bid and Bax did not correlate with that of Bcl-2 in adenocarcinoma tissues(Bid vs Bcl-2,r=-0.187, P>0.05,Bax vs Bcl-2,r=0.201,P>0.05),but correlated positively with that of Bcl-2 respectively in resection margin tissues (Bid vs Bcl-2,r=-0.331,P<0.05,Bax vs Bcl-2,r=-0.295, P<0.05).CONCLUSION:H pylorimay enhance Bid, Bax and Bcl-2 mRNA levels and cause deregulation of these apoptosis-associated genes expressions, which may play a role during development of gastric adenocarcinoma induced by H pylori.展开更多
Objective To evaluate the feasibility and safety of operative laparoscopy for ectopic pregnancy with hypovolemic shock. Methods Two hundred and fifteen women with ectopic pregnancy underwent operative laparoscopy. The...Objective To evaluate the feasibility and safety of operative laparoscopy for ectopic pregnancy with hypovolemic shock. Methods Two hundred and fifteen women with ectopic pregnancy underwent operative laparoscopy. These patients were divided into two groups. The study group included 21 patients with shock and intraperitoneal hemorrhage more than 1000 mL, and control group included 194 patients, hemodynamically stable, with blood loss less than 1000 mL. Clinical data of perio-perative periods in two groups were retrospectively analyzed. Results All patients were tubal pregnancies. The occurrence rate of tubal rupture was higher in study group than in control group (80.95% vs. 15.98%, P < 0.001). Intraabdominal blood loss was significantly higher in study group than in control group (1900 mL vs. 300 mL, P < 0.001), and autologous blood transfusions were given to 95.24% and 9.3% of patients in study and control group, respectively (P < 0.001). Laparoscopic salpingectomy was performed on 85.7 % and 50.5% of patients in study and control group (P < 0.001). The operative time was somewhat longer in study group than that in control group (60 minutes vs. 45 minutes), but with no significant difference. All patients had no perioperative complications. Conclusion Operative laparoscopy in patients with hopovolemic shock can be safely and effectively performed by experi-enced laparoscopists with the aid of optimal anesthesia, advanced cardiovascular monitoring, and autologous blood transfusion.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
目的 探究血氨在急诊科脓毒症患者预后评估中的应用,并与急诊脓毒症病死率评 分(mortality in emergency department sepsis,MEDS)进行分析比较。方法 采用回顾性临床研究,纳入2017年6月至2018年5月期间于四川大学华西医院急诊科确诊...目的 探究血氨在急诊科脓毒症患者预后评估中的应用,并与急诊脓毒症病死率评 分(mortality in emergency department sepsis,MEDS)进行分析比较。方法 采用回顾性临床研究,纳入2017年6月至2018年5月期间于四川大学华西医院急诊科确诊的、符合2001年美国胸科医师协会/危重病医学会共识会议的诊断标准的脓毒症患者的临床资料,排除伴有其他影响血氨水平的疾病及失访的对象,并收集MEDS评分,电话随访统计患者的生存情况。采用独立样本t检验比较两组间差异,应用受试者操作特性(ROC)曲线评估脓毒症病死率预测的准确性,使用logistic回归模型探讨血氨与MEDS评分联合应用的价值。结果 最终纳入80例研究对象,按预后分为1周存活组(n=52)、1周死亡组(n=28);4周存活组(n=37)、4周死亡组(n=43);12周存活组(n=33)、12周死亡组(n=47);1年存活组(n=32)、1年死亡组(n=48),组间研究对象的人口特征差异无统计学意义,所有死亡对象的血氨水平均比同期存活的患者更高[(116.57±85.33)μmol/L vs (77.64±35.82)μmol/L,(108.53±73.00)μmol/L vs (71.19±32.53)μmol/L,(106.75±71.59)μmol/L vs (69.21±28.84)μmol/L,(105.77±71.14)μmol/L vs (69.50±29.25)μmol/L,P<0.05];根据1周、4周、12周和1年后的死亡情况得出,血氨的ROC曲线下面积(AUC)分别0.668(95%CI:0.542~0.793,P=0.014)、0.706(95%CI:0.593~0.819,P=0.002)、0.705(95%CI:0.592~0.818,P=0.002)、0.697(95%CI:0.582~0.811,P=0.003);与单独使用血氨、乳酸或MEDS评分相比,血氨与MEDS的联合使用会提高对脓毒症患者预后评估的准确性(P<0.05)。结论 血氨用于预测急诊科脓毒症患者的近期和1年预后都具有较高的价值,与MEDS评分的联合使用,可以进一步提高其预测价值。展开更多
文摘AIM: To investigate the expression of NGF family and their receptors in gastric carcinoma and normal gastric mucosa,and to elucidate their effects on gastric carcinoma.METHODS: RNA of gastric cancer tissues and normal gastric tissues was respectively isolated and mRNA was purified.Probes of both mRNA reverse transcription product cDNAs labled with α-33P dATP were respectively hybridized with Atlas Array membrane where NGF and their family genes were spotted on. Hybridized signal images were scanned on phosphor screen with ImageQuant 5.1 software after hybridization. Normalized values on spots were analyzed with ArrayVersion 5.0 software. Differential expression of NGF family and their receptors mRNA was confirmed between hybridized Atlas Array membranes of gastric cancer tissues and normal gastric mucosa, then their effects on gastric carcinoma were investigated.RESULTS: Hybridization signal images on Atlas Array membrane appeared in a lower level of nonspecific hybridization. Both of NGF family and their receptors Trk family mRNA were expressed in gastric cancer and normal gastric mucosa. But adversely up-regulated expression in other tissues and organs. NGF, BDGF, NT-3, NT-4/5, NT-6and TrkA, B and C were down-regulated simultaneously in gastric carcinoma in comparison with normal gastric mucosa. Degrees of down-regulation in NGF family were greater than those in their receptors Trk family. Downregulation of NT-3 and BDGF was the most significant,and TrkC down-regulation level was the lowest in receptors Trk family.CONCLUSION: Down-regulated expression of NGF family and their receptors Trk family mRNA in gastric cancer is confirmed. NGF family and their receptors Trk family probably play a unique role in gastric cancer cell apoptosis by a novel Ras or Raf signal transduction pathway. Their synchronous effects are closely associated with occurrence and development of gastric carcinoma induced by reduction of signal transduction of programmed cell death.
文摘AIM: To study the value of monitoring K-ras point mutation at codon 12 and telomerase activity in exfoliated cells obtained from pancreatic duct brushings during endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic cancer.METHODS: Exfoliated cells obtained from pancreatic duct brushings during ERCP were examined in 27 patients: 23 with pancreatic cancers, 4 with chronic pancreatitis. K-ras point mutation was detected with the polymerase chain reaction and restriction fragment-length polymorphism(PCR-RFLP). Telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA).RESULTS: The telomerase activities in 27 patients were measured in 21 exfoliated cell samples obtained from pancreatic duct brushings. D450 value of telomerase activities in pancreatic cancer and chronic pancreatitis were 0.446+0.27 and 0.041+0.0111, respectively. Seventy-seven point eight percent (14/18) of patients with pancreatic cancer and none of the patients with chronic pancreatitis showed telomerase activity in cells collected from pancreatic duct brushings when cutoff value of telomerase activity was set at 2.0. The K-ras gene mutation rate (72.2%) in pancreatic cancer was higher than that in chronic pancreatitis (33.3%) (P<0.05). In considering of both telomerase activities and K-ras point mutation, the total positive rate was 83.3% (15/18), and the specificity was 100%.CONCLUSION: Changes of telomerase activities and K-ras point mutation at codon 12 may be an early event of malignant progression in pancreatic cancer. Detection of telomerase activity and K-ras point mutation at codon 12 may be complementary to each other, and is useful in diagnosis of pancreatic cancer.
基金the National Natural Science Foundation of China(Nos.11922205 and 11672071)the Liaoning Revitalization Talents Program(No.XLYC1807026)the Fundamental Research Funds for the Central Universities(No.N2005019)。
文摘An efficient method is developed to investigate the vibration and stability of moving plates immersed in fluid by applying the Kirchhoff plate theory and finite element method.The fluid is considered as an ideal fluid and is described with Bernoulli’s equation and the linear potential flow theory.Hamilton’s principle is used to acquire the dynamic equations of the immersed moving plate.The mass matrix,stiffness matrix,and gyroscopic inertia matrix are determined by the exact analytical integration.The numerical results show that the fundamental natural frequency of the submersed moving plates gradually decreases to zero with an increase in the axial speed,and consequently,the coupling phenomenon occurs between the first-and second-order modes.It is also found that the natural frequency of the submersed moving plates reduces with an increase in the fluid density or the immersion level.Moreover,the natural frequency will drop obviously if the plate is located near the rigid wall.In addition,the developed method has been verified in comparison with available results for special cases.
文摘Extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydro- chloride (PCN) in the system described in the title was studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, while that of PCN is 77%. This system produces the distribution coefficients (KD) of 12.3 and 2.6 respectively for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet and molecular fluorescence spectra variation of the drugs in the system studied.
基金VISTA-a basic research program funded by Statoil,conducted in close collaboration with The Norwegian Academy of Science and Letters which is gratefully acknowledged
文摘A 3D structured composite of carbon nanofibers @ MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofiber yarns were synthesized directly over copper foil through a floating catalyst method. The growth of carbon nanofiber yarns was significantly enhanced by mechanical polishing of the copper foils, which can be attributed to the increased surface roughness and surface area of the copper foils. MnO2 was then grown over carbon nanofibers through spontaneous reduction of potassium permanganate by the carbon nanofibers. The obtained composites of carbon nanofibers@MnO2 over copper foil were tested as an anode in lithium ion batteries and they show superior electrochemical performance. The initial reversible capacity of carbon nanofibers@MnO2 reaches up to around 998 mAh.g-1 at a rate of 60 mmA.g-l based on the mass of carbon nanofibers and MnO2. The carbon nanofibers @ MnO2 electrodes could deliver a capacity of 630 mAh.g-1 at the beginning and maintain a capacity of 440 mmAh.g-1 after 105 cycles at a rate of 600 mA.g-~. The high initial capacity can be attributed to the presence of porous carbon nanofiber yarns which have good electrical conductivity and the MnO2 thin film which makes the entire materials electrochemically active. The high cyclic stability of carbon nanofibers@MnO2 can be ascribed to the MnO2 thin film which can accommodate the volume expansion and shrinking during charge and discharge and the good contact of carbon nanofibers with MnO2 and copper foil.
基金support from NTNU Nanolab and financial supports from VISTA, Zhengzhou Research Institute of Chalco and Norwegian research council
文摘Electrochemical energy storage systems with high specific energy and power as well as long cyclic stability attract increasing attention in new energy technologies. The principles for rational design of electrodes are discussed to reduce the activation, concentration, and resistance overpotentials and improve the active ma- terial efficiency in order to simultaneously achieve high specific energy and power. Three dimensional （3D） nanocomposites are currently considered as promising electrode materials due to their large surface area, reduced electronic and ionic diffusion distances, and synergistic effects. This paper reviews the most recent progress on the synthesis and application of 3D thin film nanoelectrode arrays based on aligned carbon nan- otubes （ACNTs） directly grown on metal foils for energy storages and special attentions are paid on our own representative works. These novel 3D nanoelectrode arrays on metal foil exhibit improved electrochemical performances in terms of specific energy, specific power and cyclic stability due to their unique structures. In this active materials coated ACNTs over conductive substrate structures, each component is tailored to address a different demand. The electrochemical active material is used to store energy, while the ACNTs are employed to provide a large surface area to support the active material and nanocable arrays to facilitate the electron transport. The thin film of active materials can not only reduce ion transport resistance by shorten- ing the diffusion length but also make the film elastic enough to tolerate significant volume changes during charge and discharge cycles. The conductive substrate is used as the current collector and the direct contact of the ACNT arrays with the substrate reduces significantly the contact resistance. The principles obtained from ACNT based electrodes are extended to aligned graphene based electrodes. Similar improvements have been achieved which confirms the reliability of the principles obtained. In addition, we al
文摘To analyze the hazard factors for the constructors through the geographic environment along the Qinghai-Tibetan railway. On the basis of the physical examination data of the constructors, we dynamically investigated the impact of the plateau environment on the constructors’ health. We concluded the adaptation after the plain people entering into the plateau, and the application of the medical security measures and the effectiveness of the Plateau diseases preventing and controlling measures during the construction of the Qinghai-Tibetan railway. The results showed that there existed many occupational hazard factors because of the harsh environment in the Qinghai-Tibetan plateau, and they did a severe harm to the constructors. To take an effective prevention measure could apparently alleviate the occupational hazards, and ensure the safety and health of the constructors. The paper not only provided the valuable experiences for the medical support during the economic construction in the Qinghai-Tibetan plateau areas in the future, but also made a contribution for improving the development of the world plateau medicine.
文摘Objective To confirmed reliability and feasibility of intranasal nerve growth factor (NGF) bypassing the blood-brain barrier and its potential neuroprotective effects on acute cerebral ischemia. Methods (1) To assay NGF concentrations in different brain regions after middle cerebral artery occlusion (MCAO).Rats were randomly divided into intranasal (IN) NGF, intravenous (IV) NGF, and untreated group (n= 4). The concentra-tions of NGF of different brain regions in the three groups after MCAO were measured by ELISA. (2) To observe neuro-protective action of NGF on focal cerebral ischemic damage. Rats were randomly assigned to 4 groups: IN vehicle, IN NGF, IV vehicle, IV NGF (n= 8). Treatment was initiated 30 minutes after onset of MCAO and given again 24 hours later. Three neurologic behavioral tests were performed 24 and 48 hours following onset of MCAO. Corrected infarct volumes were determined 48 hours after onset of MCAO. Results The olfactory bulb in IN NGF group obtained the highest concentration (3252 pg/g) of NGF among all regions, followed by the hippocampus. The NGF concentrations in the olfactory bulb and hippocampus in IN NGF group were markedly higher than that in IV NGF and control groups. The infarct volume in IN NGF group was markedly reduced by 38.8% compared with IN vehicle group. IN NGF group vestibulum function markedly improved compared with IN vehicle group at 24 and 48 hours after onset of MCAO (P 24 h = 0.02 and P 48 h = 0.04, respectively). Conclusion Intranasal NGF could pass through the blood-brain barrier, reach the central nervous system, reduce infarct volume, and improve neurologic function in rats following MCAO. Intranasal delivery of NGF may be a promising treat-ment for stroke.
文摘Objective To estimate the frequency of various risk factors for overall stroke and to identify risk factors for cerebral infarction (CI) versus intracerebral hemorrhage (ICH) in a large hospital-based stroke registry. Methods Data from a total of 3901 patients, consisting of 3525 patients with CI and 376 patients with ICH were pros-pectively coded and entered into a computerized data bank. Results Hypertension and smoking were the most prominent factors affecting overall stroke followed by mild internal carotid artery stenosis (< 50%), hypercholesterolemia, transient ischemic attacks (TIAs), diabetes mellitus, and cardiac ischemia. Univariate analysis showed that factors in male significantly associated with CI versus ICH were old age, a family history of stroke, and intermittent claudication; whereas in female the factors were oral contraception and migraine. By multivariate analysis, in all patients, the factors significantly associated with CI as opposed to ICH were smoking, hyperch-olesterolemia, migraine, TIAs, atrial fibrillation, structural heart disease, and arterial disease. Hypertension was the only significant factor related with ICH versus CI.Conclusions The factors for ischemic and hemorrhagic stroke are not exactly the same. Cardiac and arterial disease are the most powerful factors associated with CI rather than ICH.
文摘Objective To investigate the relationship between vascular endothelial dysfunction and serum homocysteine (HCY) level in patients with coronary lesions. Methods Serum HCY, serum nitric oxide (NO), plasma endothelin-1 (ET-1), and circulation endothelial cell (CEC) were measured in 76 patients who received coronary angiography. Fifty-four patients with a stenosis of 50% or more at least in one coronary atery were as coronary artery disease (CAD) group. Other 22 cases with no recognizable plaque and/or stenosis were as control group. HCY level was detected using an enzyme immunoassay kit. NO concentration was measured using a nitrate reductase kit. Radio-immunoassay was applied to analyse the ET-1 level, and CEC was measured by flow cytometry. Results The levels of HCY, ET-1, and CEC in patients with coronary lesions were significantly increased in comparison with control group (P < 0.01), while NO level in CAD group was significantly lower compared with that in control (P < 0.01). Using a multivariate stepwise regression analysis, HCY level had a positive correlation with ET-1 level (r = 0.420, P < 0.05) and CECs number (r = 0.423, P < 0.05); and had a negative correlation with NO/ET-1 (r = -0.403, P < 0.05). But there was no significant correlation between HCY and NO levels. Conclusions HCY might lead to endothelial cell injury, which would provide a plausible mechanism for the relationship between hyperhomocysteinemia and development of coronary artery disease. HCY can be considered as a predictor for preli-minary or active coronary lesion.
文摘In this paper, we consider the blow-up of smooth solutions to the 3D ideal MHD equations. Let (u, b) be a smooth solution in (0, T). It is proved that the solution (u, b) can be extended after t = T if . This is an improvement of the result given by Caflisch, Klapper, and Steele [3].
基金Supported by the National Natural Science Foundation of China,No.30070043,and the Key Programs of the Military Medical and Health Foundation during the 10th Five-Year Plan Period,No.O1Z075
文摘AIM:To investigate the effect of Helicobacter pylori (H pylon)infection on the expressions of Bcl-2 family members in gastric adenocarcinoma.METHODS:Gastric adenocarcinoma and resection margin tissues of 95 patients were studied.Semi-quantitative RT-PCR was used to measure Bid, Bax and Bcl-2 mRNA expressions.RESULTS:Expressions of Bid and Bax in gastric adenocarcinoma tissues without H pyloriinfection,with cagA^- H pyloriinfection and cagA^+ H pyloriinfection increased significantly in turn (Bid,0.304,0.422 and 0.855 respectively, P<0.05, Bax,0.309,0.650 and 0.979 respectively, P<0.05). Bcl-2 mRNA levels increased significantly in gastric adenocarcinoma tissues with cagA^- H pylori infection and cagA^+ H pylori infection,compared with those without H pyloriin fection(0.696 and 0.849 vs0.411, P<0.05).Expressions of Bid,Bax and Bcl-2 in resection margin tissues without Hpylori infection,with cagA^- H pylori infection and cagA^+ H pylori infection increased significantly in turn (Bid, 0.377, 0.686 and 0.939 respectively, P<0.05, Bax,0.353,0.645 and 1.001 respectively,P<0.05,Bcl-2,0.371,0.487 and 0.619 respectively,P<0.05).In H pylori negative specimens,expressions of Bid and Bax correlated negatively with that of Bcl-2 respectively in adenocarcinoma tissues (Bid vs Bcl-2, r=-0.409, P<0.05,Bax vs Bcl-2,r=-0.451, P<0.05).In H pylori positive specimens,expressions of Bid and Bax did not correlate with that of Bcl-2 in adenocarcinoma tissues(Bid vs Bcl-2,r=-0.187, P>0.05,Bax vs Bcl-2,r=0.201,P>0.05),but correlated positively with that of Bcl-2 respectively in resection margin tissues (Bid vs Bcl-2,r=-0.331,P<0.05,Bax vs Bcl-2,r=-0.295, P<0.05).CONCLUSION:H pylorimay enhance Bid, Bax and Bcl-2 mRNA levels and cause deregulation of these apoptosis-associated genes expressions, which may play a role during development of gastric adenocarcinoma induced by H pylori.
文摘Objective To evaluate the feasibility and safety of operative laparoscopy for ectopic pregnancy with hypovolemic shock. Methods Two hundred and fifteen women with ectopic pregnancy underwent operative laparoscopy. These patients were divided into two groups. The study group included 21 patients with shock and intraperitoneal hemorrhage more than 1000 mL, and control group included 194 patients, hemodynamically stable, with blood loss less than 1000 mL. Clinical data of perio-perative periods in two groups were retrospectively analyzed. Results All patients were tubal pregnancies. The occurrence rate of tubal rupture was higher in study group than in control group (80.95% vs. 15.98%, P < 0.001). Intraabdominal blood loss was significantly higher in study group than in control group (1900 mL vs. 300 mL, P < 0.001), and autologous blood transfusions were given to 95.24% and 9.3% of patients in study and control group, respectively (P < 0.001). Laparoscopic salpingectomy was performed on 85.7 % and 50.5% of patients in study and control group (P < 0.001). The operative time was somewhat longer in study group than that in control group (60 minutes vs. 45 minutes), but with no significant difference. All patients had no perioperative complications. Conclusion Operative laparoscopy in patients with hopovolemic shock can be safely and effectively performed by experi-enced laparoscopists with the aid of optimal anesthesia, advanced cardiovascular monitoring, and autologous blood transfusion.
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.
文摘目的 探究血氨在急诊科脓毒症患者预后评估中的应用,并与急诊脓毒症病死率评 分(mortality in emergency department sepsis,MEDS)进行分析比较。方法 采用回顾性临床研究,纳入2017年6月至2018年5月期间于四川大学华西医院急诊科确诊的、符合2001年美国胸科医师协会/危重病医学会共识会议的诊断标准的脓毒症患者的临床资料,排除伴有其他影响血氨水平的疾病及失访的对象,并收集MEDS评分,电话随访统计患者的生存情况。采用独立样本t检验比较两组间差异,应用受试者操作特性(ROC)曲线评估脓毒症病死率预测的准确性,使用logistic回归模型探讨血氨与MEDS评分联合应用的价值。结果 最终纳入80例研究对象,按预后分为1周存活组(n=52)、1周死亡组(n=28);4周存活组(n=37)、4周死亡组(n=43);12周存活组(n=33)、12周死亡组(n=47);1年存活组(n=32)、1年死亡组(n=48),组间研究对象的人口特征差异无统计学意义,所有死亡对象的血氨水平均比同期存活的患者更高[(116.57±85.33)μmol/L vs (77.64±35.82)μmol/L,(108.53±73.00)μmol/L vs (71.19±32.53)μmol/L,(106.75±71.59)μmol/L vs (69.21±28.84)μmol/L,(105.77±71.14)μmol/L vs (69.50±29.25)μmol/L,P<0.05];根据1周、4周、12周和1年后的死亡情况得出,血氨的ROC曲线下面积(AUC)分别0.668(95%CI:0.542~0.793,P=0.014)、0.706(95%CI:0.593~0.819,P=0.002)、0.705(95%CI:0.592~0.818,P=0.002)、0.697(95%CI:0.582~0.811,P=0.003);与单独使用血氨、乳酸或MEDS评分相比,血氨与MEDS的联合使用会提高对脓毒症患者预后评估的准确性(P<0.05)。结论 血氨用于预测急诊科脓毒症患者的近期和1年预后都具有较高的价值,与MEDS评分的联合使用,可以进一步提高其预测价值。
