Operation-based flow-time estimation in dynamic job shops

Cataloged from PDF version of article.In the scheduling literature, estimation of job owtimes has been an important issue since the late 1960s. The previous studies focus on the problem in the context of due date assignment and develop methods using aggregate information in the estimation process. In this study, we propose a new owtime estimation method that utilizes the detailed job, shop and route information for operations of jobs as well as the machine imbalance information. This type of information is now available in computer-integrated manufacturing systems. The performance of the proposed method is measured by computer simulation under various experimental conditions. It is compared with the existing owtime estimation methods for a wide variety of performance measures. The results indicate that the proposed method outperforms all the other owtime estimation methods. Moreover, it is quite robust to changing shop conditions (i.e., machine breakdowns, arrival rate and processing time variations, etc.). A comprehensive bibliography is also provided in the paper. 2002 Elsevier Science Ltd. All rights reserved

An assessment of serum leptin levels in patients with chronic viral hepatitis: a prospective study

<p>Abstract</p> <p>Background</p> <p>The role of leptin in the course of liver disease due to chronic viral hepatitis (CVH) remains controversial. Our aims were to investigate the relationship between serum leptin concentrations and the severity of liver disease in a cohort of subjects with HBeAg negative chronic hepatitis B (CHB) and C (CHC) and to analyze the effect of body composition, the leptin system and insulin resistance together with viral factors on virologic response to antiviral treatment.</p> <p>Methods</p> <p>We studied 50 (36 men) consecutive patients suffering from biopsy-proven CVH due to HBV (n = 25) or HCV (n = 25) infection. Thirty-two (17 men) healthy volunteers served as controls. Levels of serum leptin and insulin were determined by immunoassays at baseline and at the end of the treatment.</p> <p>Results</p> <p>A significant association between serum leptin levels and the stage of hepatic fibrosis was noted; patients with cirrhosis presented higher serum leptin levels compared to those with lower fibrosis stage [CHB patients (17436 pg/ml vs 6028.5 pg/ml, p = 0.03), CHC patients (18014 pg/ml vs 4385 pg/ml, p = 0.05]. An inverse correlation between lower leptin levels and response to lamivudine monotherapy was noted in patients with CHB; those with a virologic response presented lower serum leptin levels (5334 vs 13111.5 pg/ml; p-value = 0.003) than non-responders. In genotype 1 CHC patients, insulin resistance played a significant role in the response to antiviral therapy.</p> <p>Conclusion</p> <p>Our data clearly suggest that cirrhosis due to CHB or CHC is associated with higher leptin levels. Increased serum leptin levels represent a negative prognostic factor for response to lamivudine monotherapy in patients with CHB. In CHC patients insulin resistance strongly influences the response to antiviral treatment in patients infected with genotype 1.</p

LEADER 5: prevalence and cardiometabolic impact of obesity in cardiovascular high-risk patients with type 2 diabetes mellitus: baseline global data from the LEADER trial

Background: Epidemiological data on obesity are needed, particularly in patients with type 2 diabetes mellitus (T2DM) and high cardiovascular (CV) risk. We used the baseline data of liraglutide effect and action in diabetes: evaluation of CV outcome results—A long term Evaluation (LEADER) (a clinical trial to assess the CV safety of liraglutide) to investigate: (i) prevalence of overweight and obesity; (ii) relationship of the major cardiometabolic risk factors with anthropometric measures of adiposity [body mass index (BMI) and waist circumference (WC)]; and (iii) cardiometabolic treatment intensity in relation to BMI and WC. Methods: LEADER enrolled two distinct populations of high-risk patients with T2DM in 32 countries: (1) aged ≥50 years with prior CV disease; (2) aged ≥60 years with one or more CV risk factors. Associations of metabolic variables, demographic variables and treatment intensity with anthropometric measurements (BMI and WC) were explored using regression models (ClinicalTrials.gov identifier: NCT01179048). Results: Mean BMI was 32.5 ± 6.3 kg/m2 and only 9.1 % had BMI &lt;25 kg/m2. The prevalence of healthy WC was also extremely low (6.4 % according to International Joint Interim Statement for the Harmonization of the Metabolic Syndrome criteria). Obesity was associated with being younger, female, previous smoker, Caucasian, American, with shorter diabetes duration, uncontrolled blood pressure (BP), antihypertensive agents, insulin plus oral antihyperglycaemic treatment, higher levels of triglycerides and lower levels of high-density lipoprotein cholesterol. Conclusions: Overweight and obesity are prevalent in high CV risk patients with T2DM. BMI and WC are related to the major cardiometabolic risk factors. Furthermore, treatment intensity, such as insulin, statins or oral antihypertensive drugs, is higher in those who are overweight or obese; while BP and lipid control in these patients are remarkably suboptimal. LEADER confers a unique opportunity to explore the longitudinal effect of weight on CV risk factors and hard endpoints

Effect of sitagliptin on cardiovascular outcomes in type 2 diabetes

BACKGROUND: Data are lacking on the long-term effect on cardiovascular events of adding sitagliptin, a dipeptidyl peptidase 4 inhibitor, to usual care in patients with type 2 diabetes and cardiovascular disease. METHODS: In this randomized, double-blind study, we assigned 14,671 patients to add either sitagliptin or placebo to their existing therapy. Open-label use of antihyperglycemic therapy was encouraged as required, aimed at reaching individually appropriate glycemic targets in all patients. To determine whether sitagliptin was noninferior to placebo, we used a relative risk of 1.3 as the marginal upper boundary. The primary cardiovascular outcome was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. RESULTS: During a median follow-up of 3.0 years, there was a small difference in glycated hemoglobin levels (least-squares mean difference for sitagliptin vs. placebo, -0.29 percentage points; 95% confidence interval [CI], -0.32 to -0.27). Overall, the primary outcome occurred in 839 patients in the sitagliptin group (11.4%; 4.06 per 100 person-years) and 851 patients in the placebo group (11.6%; 4.17 per 100 person-years). Sitagliptin was noninferior to placebo for the primary composite cardiovascular outcome (hazard ratio, 0.98; 95% CI, 0.88 to 1.09; P<0.001). Rates of hospitalization for heart failure did not differ between the two groups (hazard ratio, 1.00; 95% CI, 0.83 to 1.20; P = 0.98). There were no significant between-group differences in rates of acute pancreatitis (P = 0.07) or pancreatic cancer (P = 0.32). CONCLUSIONS: Among patients with type 2 diabetes and established cardiovascular disease, adding sitagliptin to usual care did not appear to increase the risk of major adverse cardiovascular events, hospitalization for heart failure, or other adverse events

Operation-based flowtime estimation in a dynamic job shop

In the scheduling literature, estimation of job flowtimes has been an important issue since the late 1960s. The previous studies focus on the problem in the context of due date assignment and develop methods using aggregate information in the estimation process. In this study, we propose a new flowtime estimation method that utilizes the detailed job, shop and route information for operations of jobs as well as the machine imbalance information. This type of information is now available in computer-integrated manufacturing systems. The performance of the proposed method is measured by computer simulation under various experimental conditions. It is compared with the existing flowtime estimation methods for a wide variety of performance measures. The results indicate that the proposed method outperforms all the other flowtime estimation methods. Moreover, it is quite robust to changing shop conditions (i.e., machine breakdowns, arrival rate and processing time variations, etc.). A comprehensive bibliography is also provided in the paper.Flowtime estimation Due date assignment Simulation Scheduling

Diagnostic usefulness of tumour marker levels in pleural effusions of malignant and benign origin

Pleural effusion is a common diagnostic problem. The analysis of serum and body fluids for tumor markers has been intensively applied to clinical diagnosis. The aim of the present study was to determine the usefulness of simultaneous quantification of carbohydrate antigen 19.9, carbohydrate antigen 125, neuron specific enolase, mucinous-carcinoma-associated antigen, and ferritin in samples of pleural fluids in the malign pleural effusion and its differentiation from benign effusions. A total of 61 pleural effusions were collected from the patients, who were subjected either to simple needle aspiration or to tube drainage for the diagnosis of pleural effusion. Tumor markers were determined in benign patient groups with nonspecific pleurisy, tuberculous pleurisy, empyema, congestive heart failure and in malignancy groups consisting of adenocarcinoma, small cell lung carcinoma, mesothelioma, epidermoid lung cancer. The tumor markers CA-19.9, CA-125, NSE, and ferritin levels were quantified by the sandwich assay using the streptavidin technology of ELISA in an ES-300 Boehringer-Mannheim analyser. MCA was measured by employing a two-side solid phase EIA method. MCA measurements were done by the Cobas-Core. For all patients, the effusions correctly or incorrectly identified by the different procedures as being malignant or nonmalignant are defined as true positive, false positive, true negative, and false negative, the term 'positive' referring to histologically proven malignant pleural effusion while nonmalignant effusions are referred to as 'negative'. Therefore, sensitivity, specificity, positive predictive value, and negative predictive value were defined as diagnostic parameters. The cut-off values calculated were 352 U/ml for CA-125, 54 U/ml for CA-19.9. 555 for ferritin, 11.1 for MCA and 8.7 for NSE. In our study, the highest sensitivity is found to be MCA with 100%; specificity, CA-19.9 with 97%; PPV, CA-19.9 and MCA with 95% and NPV, MCA with 100%. Our data imply that the co-measurement of MCA + CA-19.9 + CA-125 levels may further improve their diagnostic value in malignant pleural effusion compared with that of each tumour marker alone and may be useful in distinguishing malignant from benign pleural effusions. (C) 2000 Elsevier Science B.V. All rights reserved

Technetium-99m tetrofosmin uptake in insular thyroid carcinoma - A comparison with iodine-131

The authors describe a 42-year-old man with insular thyroid carcinoma. In this patient, iodine-131 (I-131) and technetium-99m (Tc-99m) tetrofosmin imaging were performed to investigate residual thyroid tissue and metastatic foci of tumor. Both I-131 and Tc-99m tetrofosmin images showed metastatic foci, but Tc-99m tetrofosmin imaging revealed the lesions better than did the I-131 scan. Tc-99m tetrofosmin imaging does not require withholding of thyroid hormone suppression and can be used for follow-up evaluation of patients with insular thyroid carcinoma

The beneficial effects of lipid-lowering drugs beyond lipid-lowering effects: A comparative study with pravastatin, atorvastatin, and fenofibrate in patients with type IIa and type IIb hyperlipidemia

Hyperlipidemia is an important risk factor for atherosclerosis. Hemorheological factors contribute to morbidity and mortality in patients with dyslipidemia. We evaluated the effects of 3 antihyperlipidemic drugs (pravastatin, atorvastatin, and fenofibrate), which have different mechanisms of action and different patterns of action on lipid profiles, on erythrocyte deformability and fibrinogen levels in patients with type IIa and type IIb hyperlipidemia. Twenty-one patients (4 men and 17 women) with type IIa and IIb hyperlipidemia were randomized to 3 drugs (pravastatin 20 mg/d, atorvastatin 10 mg/d, fenofibrate 250 mg/d) for 8 weeks. Plasma glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) analysis were performed on a BM-Hitachi 747-200 autoanalyzer (Hitachi-Roche, Tokyo, Japan). Fibrinogen analysis was performed according to Clauss method. Erythrocyte deformability was assessed with cell transit analysis device. There was no significant difference in body mass index, lipid profile, fibrinogen level, and erythrocyte deformability index values among the groups before treatment (P > .05). In all groups, there were statistically significant reductions in total LDL-C levels (P .05). There was no significant change in HDL-C levels during the treatment with statins (P > .05), but there was a significant increase in the fenofibrate group (P .05), but in fenofibrate group, fibrinogen levels were significantly decreased (P < .05)