The test section’s Mach number in wind tunnel testing is a significant metric for evaluating system performance.The quality of the flow field in the wind tunnel is contingent upon the system's capacity to maintai...The test section’s Mach number in wind tunnel testing is a significant metric for evaluating system performance.The quality of the flow field in the wind tunnel is contingent upon the system's capacity to maintain stability across various working conditions.The process flow in wind tunnel testing is inherently complex,resulting in a system characterized by nonlinearity,time lag,and multiple working conditions.To implement the predictive control algorithm,a precise Mach number prediction model must be created.Therefore,this report studies the method for Mach number prediction modelling in wind tunnel flow fields with various working conditions.Firstly,this paper introduces a continuous transonic wind tunnel.The key physical quantities affecting the flow field of the wind tunnel are determined by analyzing its structure and blowing process.Secondly,considering the nonlinear and time-lag characteristics of the wind tunnel system,a CNN-LSTM model is employed to establish the Mach number prediction model by combining the 1D-CNN algorithm with the LSTM model,which has long and short-term memory functions.Then,the attention mechanism is incorporated into the CNN-LSTM prediction model to enable the model to focus more on data with greater information importance,thereby enhancing the model's training effectiveness.The application results ultimately demonstrate the efficacy of the proposed approach.展开更多
AIM: The survival time of patients with hepatocellular carcinoma (HCC) after resection is hard to predict. Both residual liver function and tumor extension factors should be considered. A new scoring system has recent...AIM: The survival time of patients with hepatocellular carcinoma (HCC) after resection is hard to predict. Both residual liver function and tumor extension factors should be considered. A new scoring system has recently been proposed by the Cancer of the Liver Italian Program (CLIP). CLIP score was confirmed to be one of the best ways to stage patients with HCC. To our knowledge, however, the literature concerning the correlation between CLIP score and prognosis for patients with HCC after resection was not published. The aim of this study is to evaluate the recurrence and prognostic value of CLIP score for the patients with HCC after resection. METHODS: A retrospective survey was carried out in 174 patients undergoing resection of HCC from January 1986 to June 1998. Six patients who died in the hospital after operation and 11 patients with the recurrence of the disease were excluded at 1 month after hepatectomy. By the end of June 2001, 4 patients were lost and 153 patients with curative resection have been followed up for at least three years. Among 153 patients, 115 developed intrahepatic recurrence and 10 developed extrahepatic recurrence, whereas the other 28 remained free of recurrence. Recurrences were classified into early (【 or =3 year) and late (】3 year) recurrence. The CLIP score included the parameters involved in the Child-Pugh stage (0-2), plus macroscopic tumor morphology (0-2), AFP levels (0-1), and the presence or absence of portal thrombosis (0-1). By contrast, portal vein thrombosis was defined as the presence of tumor emboli within vascular channel analyzed by microscopic examination in this study. Risk factors for recurrence and prognostic factors for survival in each group were analyzed by the chi-square test, the Kaplan-Meier estimation and the COX proportional hazards model respectively. RESULTS: The 1-, 3-, 5-, 7-,and 10-year disease-free survival rates after curative resection of HCC were 57.2%, 28.3%, 23.5%, 18.8%, and 17.8%, respectively. Median survival time was 28, 10, 4, and 5 mo for CLIP score 0, 1, 2, 3, and 4 to 5, respectively. Early and late recurrence developed in 109 patients and 16 patients respectively. By the chi-square test, tumor size, microsatellite, venous invasion, tumor type (uninodular, multinodular, massive), tumor extension (【 or = or 】50% of liver parenchyma replaced by tumor), TNM stage, CLIP score, and resection margin were the risk factors for early recurrence, whereas CLIP score and Child-Pugh stage were significant risk factors for late recurrence. In univariate survival analysis, Child-Pugh stages, resection margin, tumor size, microsatellite, venous invasion, tumor type, tumor extension, TNM stages, and CLIP score were associated with prognosis. The multivariate analysis by COX proportional hazards model showed that the independent predictive factors of survival were resection margins and TNM stages. CONCLUSION: CLIP score has displayed a unique superiority in predicting the tumor early and late recurrence and prognosis in the patients with HCC after resection.展开更多
In this paper our studies about the sequential testing program for predicting and identificating carcinogens, sequential discriminant method and cost- effectiveness analysis are summarized. The analysis of our databas...In this paper our studies about the sequential testing program for predicting and identificating carcinogens, sequential discriminant method and cost- effectiveness analysis are summarized. The analysis of our database of carcinogeniclty and genotoxicity of chemicals demonstrates the uncertainty . of short- term tests ( STTs ) to predict carcinogens and the results of most routine STTs are statistically dependent. We recommend the sequential testing program combining STTs and carclnogenicity assay, the optimal STT batteries, the rules of the sequential discrimination and the preferal choices of STTs tor specific chemical class. For illustrative pmposes the carclnogenicity prediction of several sample chamicals is presented. The results of cost-effectiveness analysis suggest that this program has vast social-economic effectiveness.展开更多
Water circulation is the main disturbance source against precise gravimetry measurement which is one of the principal means of geodynamic study. Some scientists studied the disturbance of water level changes in lakes ...Water circulation is the main disturbance source against precise gravimetry measurement which is one of the principal means of geodynamic study. Some scientists studied the disturbance of water level changes in lakes andrivers and groundwater activities on gravity field.Taking water circulation as a whole and combining it with thehydrogeological conditions in northwest Yunnan mountainous area and the measured gravity data,this paperstudies the features, connections of water circulation in atmosphere,on surface and under ground and its effecton gravimetric data. The main conclusions are as follows: 1) The water circulation in atmosphere has little directdisturbance on gravity field 1 2 ) The change of lake water level may cause gravitational effect of (10- 20) × 10-8m. s-2 ; 3) In the NW Yunnan, types of the groundwater are various,and its changes are complicated, it isnecessary to study point by point. In general, its disturbance on gravity field in this region is about 10 × 10- 8m. s- 2, less than that in plain area.展开更多
AIM:To analyze the performance value of high risk factors in population-based colorectal cancer(CRC) screening in China.METHODS:We compared the performance value of the immunochemical fecal occult blood test(iFOBT) an...AIM:To analyze the performance value of high risk factors in population-based colorectal cancer(CRC) screening in China.METHODS:We compared the performance value of the immunochemical fecal occult blood test(iFOBT) and other high risk factors questionnaire in a population sample of 13 214 community residents who completed both the iFOBT and questionnaire investigation.Patients with either a positive iFOBT and/or questionnaire were regarded as a high risk population and those eligible were asked to undergo colonoscopy.RESULTS:The iFOBT had the highest positive predictive value and negative predictive value in screening for advanced neoplasia.The iFOBT had the highest sensitivity,lowest number of extra false positive results associated with the detection of one extra abnormality for screening advanced neoplasias and adenomas.A history of chronic cholecystitis or cholecystectomy,chronic appendicitis or appendectomy,and chronic diarrhea also had a higher sensitivity than a history of adenomatous polyps in screening for advanced neoplasias and adenomas.The sensitivity of a history of chronic cholecystitis or cholecystectomy was highest among the 10 high risk factors in screening for nonadenomatous polyps.A history of chronic appendicitis or appendectomy,chronic constipation,chronic diarrhea,mucous and bloody stool,CRC in first degree relatives,malignant tumor and a positive iFOBT also had higher sensitivities than a history of adenomas polyps in screening for non-adenomatous polyps.Except for a history of malignant tumor in screening for non-adenomatous polyps,the gain in sensitivity was associated with an increase in extra false positive results associated with the detection of one extra abnormality.CONCLUSION:The iFOBT may be the best marker for screening for advanced neoplasias and adenomas.Some unique high risk factors may play an important role in CRC screening in China.展开更多
AIM:To quantitatively assess the ability of double contrast-enhanced ultrasound(DCUS) to detect tumor early response to pre-operative chemotherapy.METHODS:Forty-three patients with gastric cancer treated with neoadjuv...AIM:To quantitatively assess the ability of double contrast-enhanced ultrasound(DCUS) to detect tumor early response to pre-operative chemotherapy.METHODS:Forty-three patients with gastric cancer treated with neoadjuvant chemotherapy followed by curative resection between September 2011 and February 2012 were analyzed.Pre-operative chemotherapy regimens of fluorouracil + oxaliplatin or S-1 + oxaliplatin were administered in 2-4 cycles over 6-12 wk periods.All patients underwent contrast-enhanced computed tomography(CT) scan and DCUS before and after two courses of pre-operative chemotherapy.The therapeutic response was assessed by CT using the response evaluation criteria in solid tumors(RECIST 1.1) criteria.Tumor area was assessed by DCUS as enhanced appearance of gastric carcinoma due to tumor vascularity during the contrast phase as compared to the normal gastric wall.Histopathologic analysis was carried out according to the Mandard tumor regression grade criteria and used as the reference standard.Receiver operating characteristic(ROC) analysis was used to evaluate the efficacy of DCUS parameters in differentiating histopathological responders from non-responders.RESULTS:The study population consisted of 32 men and 11 women,with mean age of 59.7 ± 11.4 years.Neither age,sex,histologic type,tumor site,T stage,nor N stage was associated with pathological response.The responders had significantly smaller mean tumor size than the non-responders(15.7 ± 7.4 cm vs 33.3 ± 14.1 cm,P < 0.01).According to Mandard's criteria,27 patients were classified as responders,with 11(40.7%) showing decreased tumor size by DCUS.In contrast,only three(18.8%) of the 16 non-responders showed decreased tumor size by DCUS(P < 0.01).The area under the ROC curve was 0.64,with a 95%CI of 0.46-0.81.The effects of several cut-off points on diagnostic parameters were calculated in the ROC curve analysis.By maximizing Youden's index(sensitivity + specificity-1),the best cut-off point for distinguishing responders from non-responders was determined,which had optimal sensitivity of 62.9% and specificity of 56.3%.Using this cut-off point,the positive and negative predictive values of DCUS for distinguishing responders from non-responders were 70.8% and 47.4%,respectively.The overall accuracy of DCUS for therapeutic response assessment was 60.5%,slightly higher than the 53.5% for CT response assessment with RECIST criteria(P = 0.663).Although the advantage was not statistically significant,likely due to the small number of cases assessed.DCUS was able to identify decreased perfusion in responders who showed no morphological change by CT imaging,which can be occluded by such treatment effects as fibrosis and edema.CONCLUSION:DCUS may represent an innovative tool for more accurately predicting histopathological response to neoadjuvant chemotherapy before surgical resection in patients with locally-advanced gastric cancer.展开更多
AIM: To demonstrate the relationship between H-ras oncogene and hepatocellular carcinoma (HCC) metastasis. METHODS: Activated H-ras oncogene was transfected into SMMC 7721, a cell line derived from human HCC, by calci...AIM: To demonstrate the relationship between H-ras oncogene and hepatocellular carcinoma (HCC) metastasis. METHODS: Activated H-ras oncogene was transfected into SMMC 7721, a cell line derived from human HCC, by calcium phosphate transfection method. Some metastasis-related parameters were detected in vitro, including adhesion assay, migration assay, expression of collagenase IV(c IV ase) and epidermal growth factor receptor (EGFR). RESULTS: The abilities of H-ras-transfected cell clones in adhesion to laminin (LN) or fibronectin (FN), migration, c IV ase secretion increased markedly, and the expression of EGFR elevated moderately. More importantly, these alterations were consistent positively with the expression of p21, the protein product of H-ras oncogene. CONCLUSION: H-ras oncogene could induce the metastatic phenotype of HCC cell in vitro to raise its metastatic potential.展开更多
AIM:The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreati...AIM:The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreatitis. METHODS:The plasma levels of C-reactive protein(CRP), lipid peroxide(LPO),myeloperoxidase(MPO)and superoxide dismutase(SOD)were measured in 13 patients with acute pancreatitis and 14 healthy volunteers. RESULTS:Among the patients with acute pancreatitis,there were higher plasma levels of LPO and MPO and lower SOD activity in patients with severe pancreatitis than in those with mild pancreatitis.However,there was no significant difference in the serum marker of oxidative stress no matter what the etiology was.The LPO level was especially correlated with the concentration of serum CRP and CT severity index. CONCLUSION:The oxygen free radicals may be closely associated with inflammatory process and the severity of acute pancreatitis.Especially,the concentration of plasma LPO is a meaningful index for determining the severity of the disease.展开更多
AIM: The optimal treatment for bile duct stones (in terms of cost, complications and accuracy) is unclear. The aim of our study was to determine the predictive factors for preoperative endoscopic retrograde cholangiop...AIM: The optimal treatment for bile duct stones (in terms of cost, complications and accuracy) is unclear. The aim of our study was to determine the predictive factors for preoperative endoscopic retrograde cholangiopancreatography (ERCP).METHODS: Patients undergoing preoperative ERCP (≤90 d before laparoscopic cholecystectomy) were evaluated in this retrospective study from the 1^st of January 1996 to the 31^st of December 2002. The indications for ERCP were elevated serum bilirubin, elevated liver function tests (LFT), dilated bile duct (≥8 mm) and/or stone at US examination, coexisting acute pancreatitis and/or acute pancreatitis or jaundice in patient's history. Suspected prognostic factors and the combination of factors were compared to the result of ERCRRESULTS: Two hundred and six preoperative ERCPs were performed during the observed period. The rate of successful cannulation for ERC was (97.1%). Bile duct stones were detected in 81 patients (39.3%), and successfully removed in 79 (97.5%). The number of prognostic factors correlated with the presence of bile duct stones. The positive predictive value for one prognostic factor was 1.2%, for two 43%,for three 72.5%, for four or more 91.4%.CONCLUSION: Based on our data preoperative ERCP is highly recommended in patients with three or more positive factors (high risk patients). In contrast, ERCP is not indicated in patients with zero or one factor (low risk patients).Preoperative ERCP should be offered to patients with two positive factors (moderate risk patients), however the practice should also be based on the local conditions (e.g.skill of the endoscopist, other diagnostic tools).展开更多
AIM:To test whether in vitro incubation of peripheral blood mononuclear cells (PBMC) with interferon (IFN) could efficiently decrease hepatitis C virus-RNA (HCV-RNA) amount and to analyze whether this effect was assoc...AIM:To test whether in vitro incubation of peripheral blood mononuclear cells (PBMC) with interferon (IFN) could efficiently decrease hepatitis C virus-RNA (HCV-RNA) amount and to analyze whether this effect was associated with clinical response to IFN.METHODS:Twenty-seven patients with histologically proven chronic hepatitis C were given intravenous administration of 6 million units (MU) IFN-β daily for 6 weeks followed by three times weekly for 20 weeks. PBMC collected before IFN therapy were incubated with IFN-β and HCV-RNA in PMBC was semi-quantitatively determined.RESULTS: Twenty-five patients completed IFN therapy.Eight patients (32%) had sustained loss of serum HCV-RNA with normal serum ALT levels after IFN therapy (complete responders).HCV-RNA in PBMC was detected in all patients,whereas it was not detected in PBMC from healthy subjects.In vitro administration of IFN-β decreased the amount of HCV-RNA in PMBC in 18 patients (72%). Eight of these patients obtained complete response. On the other hand,none of the patients whose HCV-RNA in PBMC did not decrease by IFN-β was complete responders. Multiple logistic regression analysis revealed that the decrease of HCV-RNA amount in PBMC by IFN-β was the only independent predictor for complete response (P<0.05).CONCLUSION:The effect of in vitro IFN-β on HCV in PBMC reflects clinical response and would be taken into account as a predictive marker of IFN therapy for chronic hepatitis C.展开更多
Several prediction models have been developed to estimate the outcomes of prostate biopsies. Most of these tools were designed for use with Western populations and have not been validated across different ethnic group...Several prediction models have been developed to estimate the outcomes of prostate biopsies. Most of these tools were designed for use with Western populations and have not been validated across different ethnic groups. Therefore, we evaluated the predictive value of the Prostate Cancer Prevention Trial （PCPT） and the European Randomized Study of Screening for Prostate Cancer （ERSPC） risk calculators in a Chinese cohort. Clinicopathological information was obtained from 495 Chinese men who had undergone extended prostate biopsies between January 2009 and March 2011. The estimated probabilities of prostate cancer and high-grade disease （Gleason 〉6） were calculated using the PCPT and ERSPC risk calculators. Overall measures, discrimination, calibration and clinical usefulness were assessed for the model evaluation. Of these patients, 28.7% were diagnosed with prostate cancer and 19.4% had high-grade disease. Compared to the PCPT model and the prostate-specific antigen （PSA） threshold of 4 ng m1-1, the ERSPC risk calculator exhibited better discriminative ability for predicting positive biopsies and high-grade disease （the area under the curve was 0.831 and 0.852, respectively, P〈O.01 for both）. Decision curve analysis also suggested the favourable clinical utility of the ERSPC calculator in the validation dataset. Both prediction models demonstrated miscalibration： the risk of prostate cancer and high-grade disease was overestimated by approximately 20% for a wide range of predicted probabilities. In conclusion, the ERSPC risk calculator outperformed both the PCPT model and the PSA threshold of 4 ng ml- z in predicting prostate cancer and high-grade disease in Chinese patients. However, the prediction tools derived from Western men significantly overestimated the probability of prostate cancer and high-grade disease compared to the outcomes of biopsies in a Chinese cohort.展开更多
AIM:To examine the calcium metabolism of colorectal cancer (CRC)in patients with colorectal cancer and control patients. METHODS:Seventy newly diagnosed CRC patients were included.The healthy control group was age and...AIM:To examine the calcium metabolism of colorectal cancer (CRC)in patients with colorectal cancer and control patients. METHODS:Seventy newly diagnosed CRC patients were included.The healthy control group was age and gender matched(n=32).Particular attention was devoted to the relationship between serum calcium of patients,and levels of AFP,CEA,carbohydrate antigen 19-9(CA 19-9)(that could be considered as prognostic factors).Furthermore,the Ca-sensing receptor(CaSR)gene A986S polymorphism was investigated in these patients,as well as the relationship between different CaSR genotypes and the data stated above. RESULTS:A lower level of ionized calcium(also corrected for albumin)was found in the serum of CRC patients with normal 25(OH)vitamin D levels.The ionized calcium concentration was inversely correlated with the serum level of CA.19-9.There was no difference in the distribution of CaSR genotypes,between CRC patients and general population.The genotypes did not correlate with other data examined. CONCLUSION:Based on these results,lower levels of serum calcium might be a pathogenic and prognostic factor in colorectal cancer.展开更多
AIM:To prospectively explore the role of carcinoembryonic antigen (CEA) in gallbladder bile in patients with colorectal carcinoma and the morphological and clinical features of neoplasia and the occurrence of hepatic ...AIM:To prospectively explore the role of carcinoembryonic antigen (CEA) in gallbladder bile in patients with colorectal carcinoma and the morphological and clinical features of neoplasia and the occurrence of hepatic metastases. METHODS:CEA levels in the gallbladder and peripheral blood were studied in 44 patients with colorectal carcinoma and 10 patients with uncomplicated cholelithiasis.CEA samples were collected from the gallbladder bile and peripheral blood during the operation,immediately before extirpating the colorectal neoplasia or cholecystectomy. Values of up to 5 ng/ml were considered normal for bile and serum CEA. RESULTS:In the 44 patients with colorectal carcinoma who underwent operation with curative intent,the average level of serum CEA was 8.5 ng/ml (range:0.1 to 111.0 ng/ ml) and for bile CEA it was 74.5 ng/ml (range:0.2 to 571.0 ng/ml).In the patients with uncomplicated cholelithiasis who underwent cholecystectomy,the average level of serum CEA was 2.9 ng/ml (range:1.0 to 3.5 ng/ml) and for bile CEA it was 1.2 ng/ml (range:0.3 to 2.9 ng/ml). The average duration of follow-up time was 16.5 months (range:6 to 48 months).Four patients who underwent extirpation of the colorectal carcinoma without evidence of hepatic metastasis and with an average bile CEA value of 213.2 ng/ml presented hepatic metastases between three and seventeen months after removal of the primary colorectal neoplasia.Three of them successfully underwent extirpation of the hepatic lesions. CONCLUSION:High CEA levels in gallbladders of patients undergoing curative operation for colorectal carcinoma may indicate the presence of hepatic metastases.Such patients must be followed up with special attention to the diagnosis of such lesions.展开更多
AIM:The mostly known genotypic virulence features,of H.pylori are cytotoxin associated gene A (cagA) and Vacuolating cytotoxin gene A (VacA).We investigated the association of these major virulence factors with ulcer ...AIM:The mostly known genotypic virulence features,of H.pylori are cytotoxin associated gene A (cagA) and Vacuolating cytotoxin gene A (VacA).We investigated the association of these major virulence factors with ulcer and non-ulcer dyspepsia in our region. METHODS:One hundred and forty two dyspeptic patients were studied (average age 44.8±15.9 years,range 15-87 years,64 males and 78 females).Antral and corpus biopsies were taken for detecting and genotyping of H.pylori.107 patients who were H.pylori positive by histological assessment were divided into three groups according to endoscopic findings:Duodenal ulcer (DU),gastric ulcer (GU) and non-ulcer dyspepsia (NUD).The polymerase chain reaction (PCR) was used to detect CagA and VacA genes of H.pylori using specific primers. RESULTS:H.pyloriwas isolated from 75.4% (107/142) of the patients.Of the 107 patients,66 (61.7%) were cagA- positive and 82 (76.6%) were VacA-positive.CagA gene was positively associated with DU and GU (P<0.01,P<0.02), but not with NUD (P>0.05).Although VacA positivity in ulcer patients was higher than that in NUD group,the difference was not statistically significant (P>0.05). CONCLUSION:There is a significantly positive association between CagA genes and DU and GU.The presence of VacA is not a predictive marker for DU,GU,and NUD in our patients.展开更多
INTRODUCTIONThe increased expression of ICAM-1 on a widerange of cells and in the sera of patients withmalignancies, chronic liver diseases andinflammation diseases has been described since thelate 1980s[1-22]. Recent...INTRODUCTIONThe increased expression of ICAM-1 on a widerange of cells and in the sera of patients withmalignancies, chronic liver diseases andinflammation diseases has been described since thelate 1980s[1-22]. Recently rapid progress in studieson expression of ICAM-1 in patients withhepatocellular carcinoma ( HCC ) have beenachieved, including clinical and experimentalresearches[23-31].展开更多
AIM:This study was designed to compare the levels of v5 and v6 splice variants of CD44 evaluated using EITSA test in the serum of patients with colorectal cancer in different stages of progression of the disease estim...AIM:This study was designed to compare the levels of v5 and v6 splice variants of CD44 evaluated using EITSA test in the serum of patients with colorectal cancer in different stages of progression of the disease estimated in pT stage according to WHO score,histopathological grade of malignancy and some clinicopathological features. METHODS:The serum obtained from 114 persons with colorectal adenocarcinomas was examined using ELISA method,pT stage and grade of malignancy of the tumour were examined in formalin fixed and paraffin embedded materials obtained during operation. RESULTS:Only the level of CD44 v5 in the serum of patients before operation with G2 pT4 tumour was lower than that in other probes and the difference was statistically significant. We did not find any other correlations between the level of v5 and v6 CD44 variants and other evaluated parameters. CONCLUSION:The level of CD44 v5 and v6 estimated by ELISA test in the serum can not be used as a prognostic factor in colorectal cancer.展开更多
AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay con...AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation. RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis. CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.展开更多
To solve the problems of blindness and inefficiency existing in the determination of meso-level mechanical parameters of particle flow code (PFC) models, we firstly designed and numerically carried out orthogonal test...To solve the problems of blindness and inefficiency existing in the determination of meso-level mechanical parameters of particle flow code (PFC) models, we firstly designed and numerically carried out orthogonal tests on rock samples to investigate the correlations between macro-and meso-level mechanical parameters of rock-like bonded granular materials. Then based on the artificial intelligent technology, the intelligent prediction systems for nine meso-level mechanical parameters of PFC models were obtained by creating, training and testing the prediction models with the set of data got from the orthogonal tests. Lastly the prediction systems were used to predict the meso-level mechanical parameters of one kind of sandy mudstone, and according to the predicted results the macroscopic properties of the rock were obtained by numerical tests. The maximum relative error between the numerical test results and real rock properties is 3.28% which satisfies the precision requirement in engineering. It shows that this paper provides a fast and accurate method for the determination of meso-level mechanical parameters of PFC models.展开更多
The authors of the World Health Organization Semen Analysis Manual are to be congratulated on producing a new edition; it is an essential tool to disseminate good practice in andrology. However, the tests described ha...The authors of the World Health Organization Semen Analysis Manual are to be congratulated on producing a new edition; it is an essential tool to disseminate good practice in andrology. However, the tests described have poor prognostic power to predict a man＇s fertility and show little about the underlying causes of sub-fertility. This commentary urges a revival of research into the diagnosis of male fertility. It suggests that fertility should be regarded as a continuum and that the artificial binary division between fertile and infertile should be abandoned. Models to predict a sub-fertile couple＇s chance of conception in a year should be developed on the basis of prospective data. These models would allow for sophisticated decision making about management. The future lies in the identification of tests to detect underlying pathologies open to specific treatment. Leads such as oxidative stress, defects in the intracellular regulation and the developing field ofproteomics should be explored.展开更多
AIM: To asses the relationship between severity of gastroesophageal refluxe disease and Epworth sleepiness scale as an indicator of daytime somnolence. METHODS: One hundred and thirty-four patients underwent an upper ...AIM: To asses the relationship between severity of gastroesophageal refluxe disease and Epworth sleepiness scale as an indicator of daytime somnolence. METHODS: One hundred and thirty-four patients underwent an upper panendoscopy as indicated by the typical reflux symptoms and were also investigated with regard to somnolence. Sleepiness was evaluated by Epworth Sleepiness Scale, which was compared to the severity of endoscopic findings (Savary-Miller/modified by Siewert). Patients with psychiatric disorders or being on sedato-hypnotics as well as shift workers were excluded from the study. The relationship between the severity of the reflux disease and daytime somnolence was analyzed with the help of multivariate regression analysis. RESULTS: A positive tendency was found between the severity of the reflux disease and the corresponding Epworth Sleepiness Scale. In the case of the more severe type-Savary-Miller Ⅲ- at least a mild hypersomnia was found. For this group daytime somnolence was significantly higher than in the case of the non-erosive type of Gastroesophageal Reflux Disease representing the mildest stage of reflux disease. CONCLUSION: The severity of Gastroesophageal Reflux Disease influences daytime somnolence.展开更多
基金funded by the National Natural Science Foundation of China(No.61503069)the Fundamental Research Funds for the Central Universities(N150404020).
文摘The test section’s Mach number in wind tunnel testing is a significant metric for evaluating system performance.The quality of the flow field in the wind tunnel is contingent upon the system's capacity to maintain stability across various working conditions.The process flow in wind tunnel testing is inherently complex,resulting in a system characterized by nonlinearity,time lag,and multiple working conditions.To implement the predictive control algorithm,a precise Mach number prediction model must be created.Therefore,this report studies the method for Mach number prediction modelling in wind tunnel flow fields with various working conditions.Firstly,this paper introduces a continuous transonic wind tunnel.The key physical quantities affecting the flow field of the wind tunnel are determined by analyzing its structure and blowing process.Secondly,considering the nonlinear and time-lag characteristics of the wind tunnel system,a CNN-LSTM model is employed to establish the Mach number prediction model by combining the 1D-CNN algorithm with the LSTM model,which has long and short-term memory functions.Then,the attention mechanism is incorporated into the CNN-LSTM prediction model to enable the model to focus more on data with greater information importance,thereby enhancing the model's training effectiveness.The application results ultimately demonstrate the efficacy of the proposed approach.
文摘AIM: The survival time of patients with hepatocellular carcinoma (HCC) after resection is hard to predict. Both residual liver function and tumor extension factors should be considered. A new scoring system has recently been proposed by the Cancer of the Liver Italian Program (CLIP). CLIP score was confirmed to be one of the best ways to stage patients with HCC. To our knowledge, however, the literature concerning the correlation between CLIP score and prognosis for patients with HCC after resection was not published. The aim of this study is to evaluate the recurrence and prognostic value of CLIP score for the patients with HCC after resection. METHODS: A retrospective survey was carried out in 174 patients undergoing resection of HCC from January 1986 to June 1998. Six patients who died in the hospital after operation and 11 patients with the recurrence of the disease were excluded at 1 month after hepatectomy. By the end of June 2001, 4 patients were lost and 153 patients with curative resection have been followed up for at least three years. Among 153 patients, 115 developed intrahepatic recurrence and 10 developed extrahepatic recurrence, whereas the other 28 remained free of recurrence. Recurrences were classified into early (【 or =3 year) and late (】3 year) recurrence. The CLIP score included the parameters involved in the Child-Pugh stage (0-2), plus macroscopic tumor morphology (0-2), AFP levels (0-1), and the presence or absence of portal thrombosis (0-1). By contrast, portal vein thrombosis was defined as the presence of tumor emboli within vascular channel analyzed by microscopic examination in this study. Risk factors for recurrence and prognostic factors for survival in each group were analyzed by the chi-square test, the Kaplan-Meier estimation and the COX proportional hazards model respectively. RESULTS: The 1-, 3-, 5-, 7-,and 10-year disease-free survival rates after curative resection of HCC were 57.2%, 28.3%, 23.5%, 18.8%, and 17.8%, respectively. Median survival time was 28, 10, 4, and 5 mo for CLIP score 0, 1, 2, 3, and 4 to 5, respectively. Early and late recurrence developed in 109 patients and 16 patients respectively. By the chi-square test, tumor size, microsatellite, venous invasion, tumor type (uninodular, multinodular, massive), tumor extension (【 or = or 】50% of liver parenchyma replaced by tumor), TNM stage, CLIP score, and resection margin were the risk factors for early recurrence, whereas CLIP score and Child-Pugh stage were significant risk factors for late recurrence. In univariate survival analysis, Child-Pugh stages, resection margin, tumor size, microsatellite, venous invasion, tumor type, tumor extension, TNM stages, and CLIP score were associated with prognosis. The multivariate analysis by COX proportional hazards model showed that the independent predictive factors of survival were resection margins and TNM stages. CONCLUSION: CLIP score has displayed a unique superiority in predicting the tumor early and late recurrence and prognosis in the patients with HCC after resection.
文摘In this paper our studies about the sequential testing program for predicting and identificating carcinogens, sequential discriminant method and cost- effectiveness analysis are summarized. The analysis of our database of carcinogeniclty and genotoxicity of chemicals demonstrates the uncertainty . of short- term tests ( STTs ) to predict carcinogens and the results of most routine STTs are statistically dependent. We recommend the sequential testing program combining STTs and carclnogenicity assay, the optimal STT batteries, the rules of the sequential discrimination and the preferal choices of STTs tor specific chemical class. For illustrative pmposes the carclnogenicity prediction of several sample chamicals is presented. The results of cost-effectiveness analysis suggest that this program has vast social-economic effectiveness.
文摘Water circulation is the main disturbance source against precise gravimetry measurement which is one of the principal means of geodynamic study. Some scientists studied the disturbance of water level changes in lakes andrivers and groundwater activities on gravity field.Taking water circulation as a whole and combining it with thehydrogeological conditions in northwest Yunnan mountainous area and the measured gravity data,this paperstudies the features, connections of water circulation in atmosphere,on surface and under ground and its effecton gravimetric data. The main conclusions are as follows: 1) The water circulation in atmosphere has little directdisturbance on gravity field 1 2 ) The change of lake water level may cause gravitational effect of (10- 20) × 10-8m. s-2 ; 3) In the NW Yunnan, types of the groundwater are various,and its changes are complicated, it isnecessary to study point by point. In general, its disturbance on gravity field in this region is about 10 × 10- 8m. s- 2, less than that in plain area.
基金Supported by 11th 5-Year Key Programs for Science and Technology Development of China,No.2006BAI02A08
文摘AIM:To analyze the performance value of high risk factors in population-based colorectal cancer(CRC) screening in China.METHODS:We compared the performance value of the immunochemical fecal occult blood test(iFOBT) and other high risk factors questionnaire in a population sample of 13 214 community residents who completed both the iFOBT and questionnaire investigation.Patients with either a positive iFOBT and/or questionnaire were regarded as a high risk population and those eligible were asked to undergo colonoscopy.RESULTS:The iFOBT had the highest positive predictive value and negative predictive value in screening for advanced neoplasia.The iFOBT had the highest sensitivity,lowest number of extra false positive results associated with the detection of one extra abnormality for screening advanced neoplasias and adenomas.A history of chronic cholecystitis or cholecystectomy,chronic appendicitis or appendectomy,and chronic diarrhea also had a higher sensitivity than a history of adenomatous polyps in screening for advanced neoplasias and adenomas.The sensitivity of a history of chronic cholecystitis or cholecystectomy was highest among the 10 high risk factors in screening for nonadenomatous polyps.A history of chronic appendicitis or appendectomy,chronic constipation,chronic diarrhea,mucous and bloody stool,CRC in first degree relatives,malignant tumor and a positive iFOBT also had higher sensitivities than a history of adenomas polyps in screening for non-adenomatous polyps.Except for a history of malignant tumor in screening for non-adenomatous polyps,the gain in sensitivity was associated with an increase in extra false positive results associated with the detection of one extra abnormality.CONCLUSION:The iFOBT may be the best marker for screening for advanced neoplasias and adenomas.Some unique high risk factors may play an important role in CRC screening in China.
基金Supported by National Science Foundation of China,No. 81101834Projects of the Health Bureau of Zhejiang Province, No.2009QN011 and 2011KYB037
文摘AIM:To quantitatively assess the ability of double contrast-enhanced ultrasound(DCUS) to detect tumor early response to pre-operative chemotherapy.METHODS:Forty-three patients with gastric cancer treated with neoadjuvant chemotherapy followed by curative resection between September 2011 and February 2012 were analyzed.Pre-operative chemotherapy regimens of fluorouracil + oxaliplatin or S-1 + oxaliplatin were administered in 2-4 cycles over 6-12 wk periods.All patients underwent contrast-enhanced computed tomography(CT) scan and DCUS before and after two courses of pre-operative chemotherapy.The therapeutic response was assessed by CT using the response evaluation criteria in solid tumors(RECIST 1.1) criteria.Tumor area was assessed by DCUS as enhanced appearance of gastric carcinoma due to tumor vascularity during the contrast phase as compared to the normal gastric wall.Histopathologic analysis was carried out according to the Mandard tumor regression grade criteria and used as the reference standard.Receiver operating characteristic(ROC) analysis was used to evaluate the efficacy of DCUS parameters in differentiating histopathological responders from non-responders.RESULTS:The study population consisted of 32 men and 11 women,with mean age of 59.7 ± 11.4 years.Neither age,sex,histologic type,tumor site,T stage,nor N stage was associated with pathological response.The responders had significantly smaller mean tumor size than the non-responders(15.7 ± 7.4 cm vs 33.3 ± 14.1 cm,P < 0.01).According to Mandard's criteria,27 patients were classified as responders,with 11(40.7%) showing decreased tumor size by DCUS.In contrast,only three(18.8%) of the 16 non-responders showed decreased tumor size by DCUS(P < 0.01).The area under the ROC curve was 0.64,with a 95%CI of 0.46-0.81.The effects of several cut-off points on diagnostic parameters were calculated in the ROC curve analysis.By maximizing Youden's index(sensitivity + specificity-1),the best cut-off point for distinguishing responders from non-responders was determined,which had optimal sensitivity of 62.9% and specificity of 56.3%.Using this cut-off point,the positive and negative predictive values of DCUS for distinguishing responders from non-responders were 70.8% and 47.4%,respectively.The overall accuracy of DCUS for therapeutic response assessment was 60.5%,slightly higher than the 53.5% for CT response assessment with RECIST criteria(P = 0.663).Although the advantage was not statistically significant,likely due to the small number of cases assessed.DCUS was able to identify decreased perfusion in responders who showed no morphological change by CT imaging,which can be occluded by such treatment effects as fibrosis and edema.CONCLUSION:DCUS may represent an innovative tool for more accurately predicting histopathological response to neoadjuvant chemotherapy before surgical resection in patients with locally-advanced gastric cancer.
文摘AIM: To demonstrate the relationship between H-ras oncogene and hepatocellular carcinoma (HCC) metastasis. METHODS: Activated H-ras oncogene was transfected into SMMC 7721, a cell line derived from human HCC, by calcium phosphate transfection method. Some metastasis-related parameters were detected in vitro, including adhesion assay, migration assay, expression of collagenase IV(c IV ase) and epidermal growth factor receptor (EGFR). RESULTS: The abilities of H-ras-transfected cell clones in adhesion to laminin (LN) or fibronectin (FN), migration, c IV ase secretion increased markedly, and the expression of EGFR elevated moderately. More importantly, these alterations were consistent positively with the expression of p21, the protein product of H-ras oncogene. CONCLUSION: H-ras oncogene could induce the metastatic phenotype of HCC cell in vitro to raise its metastatic potential.
文摘AIM:The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreatitis. METHODS:The plasma levels of C-reactive protein(CRP), lipid peroxide(LPO),myeloperoxidase(MPO)and superoxide dismutase(SOD)were measured in 13 patients with acute pancreatitis and 14 healthy volunteers. RESULTS:Among the patients with acute pancreatitis,there were higher plasma levels of LPO and MPO and lower SOD activity in patients with severe pancreatitis than in those with mild pancreatitis.However,there was no significant difference in the serum marker of oxidative stress no matter what the etiology was.The LPO level was especially correlated with the concentration of serum CRP and CT severity index. CONCLUSION:The oxygen free radicals may be closely associated with inflammatory process and the severity of acute pancreatitis.Especially,the concentration of plasma LPO is a meaningful index for determining the severity of the disease.
文摘AIM: The optimal treatment for bile duct stones (in terms of cost, complications and accuracy) is unclear. The aim of our study was to determine the predictive factors for preoperative endoscopic retrograde cholangiopancreatography (ERCP).METHODS: Patients undergoing preoperative ERCP (≤90 d before laparoscopic cholecystectomy) were evaluated in this retrospective study from the 1^st of January 1996 to the 31^st of December 2002. The indications for ERCP were elevated serum bilirubin, elevated liver function tests (LFT), dilated bile duct (≥8 mm) and/or stone at US examination, coexisting acute pancreatitis and/or acute pancreatitis or jaundice in patient's history. Suspected prognostic factors and the combination of factors were compared to the result of ERCRRESULTS: Two hundred and six preoperative ERCPs were performed during the observed period. The rate of successful cannulation for ERC was (97.1%). Bile duct stones were detected in 81 patients (39.3%), and successfully removed in 79 (97.5%). The number of prognostic factors correlated with the presence of bile duct stones. The positive predictive value for one prognostic factor was 1.2%, for two 43%,for three 72.5%, for four or more 91.4%.CONCLUSION: Based on our data preoperative ERCP is highly recommended in patients with three or more positive factors (high risk patients). In contrast, ERCP is not indicated in patients with zero or one factor (low risk patients).Preoperative ERCP should be offered to patients with two positive factors (moderate risk patients), however the practice should also be based on the local conditions (e.g.skill of the endoscopist, other diagnostic tools).
文摘AIM:To test whether in vitro incubation of peripheral blood mononuclear cells (PBMC) with interferon (IFN) could efficiently decrease hepatitis C virus-RNA (HCV-RNA) amount and to analyze whether this effect was associated with clinical response to IFN.METHODS:Twenty-seven patients with histologically proven chronic hepatitis C were given intravenous administration of 6 million units (MU) IFN-β daily for 6 weeks followed by three times weekly for 20 weeks. PBMC collected before IFN therapy were incubated with IFN-β and HCV-RNA in PMBC was semi-quantitatively determined.RESULTS: Twenty-five patients completed IFN therapy.Eight patients (32%) had sustained loss of serum HCV-RNA with normal serum ALT levels after IFN therapy (complete responders).HCV-RNA in PBMC was detected in all patients,whereas it was not detected in PBMC from healthy subjects.In vitro administration of IFN-β decreased the amount of HCV-RNA in PMBC in 18 patients (72%). Eight of these patients obtained complete response. On the other hand,none of the patients whose HCV-RNA in PBMC did not decrease by IFN-β was complete responders. Multiple logistic regression analysis revealed that the decrease of HCV-RNA amount in PBMC by IFN-β was the only independent predictor for complete response (P<0.05).CONCLUSION:The effect of in vitro IFN-β on HCV in PBMC reflects clinical response and would be taken into account as a predictive marker of IFN therapy for chronic hepatitis C.
文摘Several prediction models have been developed to estimate the outcomes of prostate biopsies. Most of these tools were designed for use with Western populations and have not been validated across different ethnic groups. Therefore, we evaluated the predictive value of the Prostate Cancer Prevention Trial （PCPT） and the European Randomized Study of Screening for Prostate Cancer （ERSPC） risk calculators in a Chinese cohort. Clinicopathological information was obtained from 495 Chinese men who had undergone extended prostate biopsies between January 2009 and March 2011. The estimated probabilities of prostate cancer and high-grade disease （Gleason 〉6） were calculated using the PCPT and ERSPC risk calculators. Overall measures, discrimination, calibration and clinical usefulness were assessed for the model evaluation. Of these patients, 28.7% were diagnosed with prostate cancer and 19.4% had high-grade disease. Compared to the PCPT model and the prostate-specific antigen （PSA） threshold of 4 ng m1-1, the ERSPC risk calculator exhibited better discriminative ability for predicting positive biopsies and high-grade disease （the area under the curve was 0.831 and 0.852, respectively, P〈O.01 for both）. Decision curve analysis also suggested the favourable clinical utility of the ERSPC calculator in the validation dataset. Both prediction models demonstrated miscalibration： the risk of prostate cancer and high-grade disease was overestimated by approximately 20% for a wide range of predicted probabilities. In conclusion, the ERSPC risk calculator outperformed both the PCPT model and the PSA threshold of 4 ng ml- z in predicting prostate cancer and high-grade disease in Chinese patients. However, the prediction tools derived from Western men significantly overestimated the probability of prostate cancer and high-grade disease compared to the outcomes of biopsies in a Chinese cohort.
文摘AIM:To examine the calcium metabolism of colorectal cancer (CRC)in patients with colorectal cancer and control patients. METHODS:Seventy newly diagnosed CRC patients were included.The healthy control group was age and gender matched(n=32).Particular attention was devoted to the relationship between serum calcium of patients,and levels of AFP,CEA,carbohydrate antigen 19-9(CA 19-9)(that could be considered as prognostic factors).Furthermore,the Ca-sensing receptor(CaSR)gene A986S polymorphism was investigated in these patients,as well as the relationship between different CaSR genotypes and the data stated above. RESULTS:A lower level of ionized calcium(also corrected for albumin)was found in the serum of CRC patients with normal 25(OH)vitamin D levels.The ionized calcium concentration was inversely correlated with the serum level of CA.19-9.There was no difference in the distribution of CaSR genotypes,between CRC patients and general population.The genotypes did not correlate with other data examined. CONCLUSION:Based on these results,lower levels of serum calcium might be a pathogenic and prognostic factor in colorectal cancer.
文摘AIM:To prospectively explore the role of carcinoembryonic antigen (CEA) in gallbladder bile in patients with colorectal carcinoma and the morphological and clinical features of neoplasia and the occurrence of hepatic metastases. METHODS:CEA levels in the gallbladder and peripheral blood were studied in 44 patients with colorectal carcinoma and 10 patients with uncomplicated cholelithiasis.CEA samples were collected from the gallbladder bile and peripheral blood during the operation,immediately before extirpating the colorectal neoplasia or cholecystectomy. Values of up to 5 ng/ml were considered normal for bile and serum CEA. RESULTS:In the 44 patients with colorectal carcinoma who underwent operation with curative intent,the average level of serum CEA was 8.5 ng/ml (range:0.1 to 111.0 ng/ ml) and for bile CEA it was 74.5 ng/ml (range:0.2 to 571.0 ng/ml).In the patients with uncomplicated cholelithiasis who underwent cholecystectomy,the average level of serum CEA was 2.9 ng/ml (range:1.0 to 3.5 ng/ml) and for bile CEA it was 1.2 ng/ml (range:0.3 to 2.9 ng/ml). The average duration of follow-up time was 16.5 months (range:6 to 48 months).Four patients who underwent extirpation of the colorectal carcinoma without evidence of hepatic metastasis and with an average bile CEA value of 213.2 ng/ml presented hepatic metastases between three and seventeen months after removal of the primary colorectal neoplasia.Three of them successfully underwent extirpation of the hepatic lesions. CONCLUSION:High CEA levels in gallbladders of patients undergoing curative operation for colorectal carcinoma may indicate the presence of hepatic metastases.Such patients must be followed up with special attention to the diagnosis of such lesions.
文摘AIM:The mostly known genotypic virulence features,of H.pylori are cytotoxin associated gene A (cagA) and Vacuolating cytotoxin gene A (VacA).We investigated the association of these major virulence factors with ulcer and non-ulcer dyspepsia in our region. METHODS:One hundred and forty two dyspeptic patients were studied (average age 44.8±15.9 years,range 15-87 years,64 males and 78 females).Antral and corpus biopsies were taken for detecting and genotyping of H.pylori.107 patients who were H.pylori positive by histological assessment were divided into three groups according to endoscopic findings:Duodenal ulcer (DU),gastric ulcer (GU) and non-ulcer dyspepsia (NUD).The polymerase chain reaction (PCR) was used to detect CagA and VacA genes of H.pylori using specific primers. RESULTS:H.pyloriwas isolated from 75.4% (107/142) of the patients.Of the 107 patients,66 (61.7%) were cagA- positive and 82 (76.6%) were VacA-positive.CagA gene was positively associated with DU and GU (P<0.01,P<0.02), but not with NUD (P>0.05).Although VacA positivity in ulcer patients was higher than that in NUD group,the difference was not statistically significant (P>0.05). CONCLUSION:There is a significantly positive association between CagA genes and DU and GU.The presence of VacA is not a predictive marker for DU,GU,and NUD in our patients.
基金Supported by the grant from the Guangxi ScienceTechnology Committee, No. 9811003
文摘INTRODUCTIONThe increased expression of ICAM-1 on a widerange of cells and in the sera of patients withmalignancies, chronic liver diseases andinflammation diseases has been described since thelate 1980s[1-22]. Recently rapid progress in studieson expression of ICAM-1 in patients withhepatocellular carcinoma ( HCC ) have beenachieved, including clinical and experimentalresearches[23-31].
文摘AIM:This study was designed to compare the levels of v5 and v6 splice variants of CD44 evaluated using EITSA test in the serum of patients with colorectal cancer in different stages of progression of the disease estimated in pT stage according to WHO score,histopathological grade of malignancy and some clinicopathological features. METHODS:The serum obtained from 114 persons with colorectal adenocarcinomas was examined using ELISA method,pT stage and grade of malignancy of the tumour were examined in formalin fixed and paraffin embedded materials obtained during operation. RESULTS:Only the level of CD44 v5 in the serum of patients before operation with G2 pT4 tumour was lower than that in other probes and the difference was statistically significant. We did not find any other correlations between the level of v5 and v6 CD44 variants and other evaluated parameters. CONCLUSION:The level of CD44 v5 and v6 estimated by ELISA test in the serum can not be used as a prognostic factor in colorectal cancer.
基金the National Nature Science Foundation of China,No.39800121
文摘AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation. RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis. CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.
基金the National Natural Science Foundation of China (Nos. 50674083 and 51074162) for its financial support
文摘To solve the problems of blindness and inefficiency existing in the determination of meso-level mechanical parameters of particle flow code (PFC) models, we firstly designed and numerically carried out orthogonal tests on rock samples to investigate the correlations between macro-and meso-level mechanical parameters of rock-like bonded granular materials. Then based on the artificial intelligent technology, the intelligent prediction systems for nine meso-level mechanical parameters of PFC models were obtained by creating, training and testing the prediction models with the set of data got from the orthogonal tests. Lastly the prediction systems were used to predict the meso-level mechanical parameters of one kind of sandy mudstone, and according to the predicted results the macroscopic properties of the rock were obtained by numerical tests. The maximum relative error between the numerical test results and real rock properties is 3.28% which satisfies the precision requirement in engineering. It shows that this paper provides a fast and accurate method for the determination of meso-level mechanical parameters of PFC models.
文摘The authors of the World Health Organization Semen Analysis Manual are to be congratulated on producing a new edition; it is an essential tool to disseminate good practice in andrology. However, the tests described have poor prognostic power to predict a man＇s fertility and show little about the underlying causes of sub-fertility. This commentary urges a revival of research into the diagnosis of male fertility. It suggests that fertility should be regarded as a continuum and that the artificial binary division between fertile and infertile should be abandoned. Models to predict a sub-fertile couple＇s chance of conception in a year should be developed on the basis of prospective data. These models would allow for sophisticated decision making about management. The future lies in the identification of tests to detect underlying pathologies open to specific treatment. Leads such as oxidative stress, defects in the intracellular regulation and the developing field ofproteomics should be explored.
文摘AIM: To asses the relationship between severity of gastroesophageal refluxe disease and Epworth sleepiness scale as an indicator of daytime somnolence. METHODS: One hundred and thirty-four patients underwent an upper panendoscopy as indicated by the typical reflux symptoms and were also investigated with regard to somnolence. Sleepiness was evaluated by Epworth Sleepiness Scale, which was compared to the severity of endoscopic findings (Savary-Miller/modified by Siewert). Patients with psychiatric disorders or being on sedato-hypnotics as well as shift workers were excluded from the study. The relationship between the severity of the reflux disease and daytime somnolence was analyzed with the help of multivariate regression analysis. RESULTS: A positive tendency was found between the severity of the reflux disease and the corresponding Epworth Sleepiness Scale. In the case of the more severe type-Savary-Miller Ⅲ- at least a mild hypersomnia was found. For this group daytime somnolence was significantly higher than in the case of the non-erosive type of Gastroesophageal Reflux Disease representing the mildest stage of reflux disease. CONCLUSION: The severity of Gastroesophageal Reflux Disease influences daytime somnolence.
