Determination of micro-scale plastic strain caused by orthogonal cutting

An electron beam lithography technique has been used to produce microgrids in order to measure local plastic strains, induced during an orthogonal cutting process, at the microscopic scale in the shear zone and under the machined surface. Microgrids with a 10 μm pitch and a line width less than 1 μm have been printed on the polished surface of an aluminium alloy AA 5182 to test the applicability of the technique in metal cutting operations. Orthogonal cutting tests were carried out at 40 mm/s. Results show that the distortion of the grids could successfully be used to compute plastic strains due to orthogonal cutting with higher accuracy compared to other techniques reported in the literature. Strain maps of the machined specimens have been produced and show high-strain gradients very close to the machined surface with local values reaching 2.2. High-resolution strain measurements carried out in the primary deformation zone also provide new insight into the material deformation during the chip formation process

A survey on some risk factors and evaluation of their impacts on streptococcosis incidence in rainbow trout farms in west of Mazandaran province

This study aimed to investigate the effects of 5- parameter dissolved oxygen, PH, nitrite, nitrate and temperature of the water on Streptococcosis incidence in two groups of fry and grower fish. Research was performed at west Mazandaran province -Tonkabon region in 12 rainbow trout selected farms. Research conducted in 3 farms with well source water, 8 farms with water source of the river of Dohezar and one farm with water source of the river of Azarood, during 12 consecutive months. From 1390.04.01 to 1391.04.01, once time each month, and in each time 10 fish randomly sampled, inlet water were sampled simultaneously Of 1350 sampled fish 607 fish with an average weight 22.04 gr, average length 12.59 cm were in fry category and 743 fish with an average weight 156.25 gr, average length 23.32 cm in were grower category. Streptococcosis observed only in grower category Of 72 fish with clinical signs of the disease, 14 numbers were positive Streptococcosis (19.44%) and 58 numbers were negative Streptococcosis (80.55%). Three fish from grower category has not any clinical signs of disease and seemed to be healthy but were positive Streptococcosis in examinations (0.22% of total fish sampled. Fish with clinical signs of the disease but negative Streptococcosis were of at least 55.1 gr and at most weight 417 gr respectively. The results showed that 47.07% cases of Streptococcosis happened at 15.6°C water temperature, 35.29% at 16.98°C and 17.64% cases happened at 18.04°C so that 100% of Streptococcosis cases was observed at the average temperature of 16.99°C. In addition, the survey results show that despite relatively high levels of nitrite in source water of farms from wells, nitrite does not effect on the disease incidence. It seems that an optimal level of dissolved oxygen in water is effective in reducing the effectiveness of nitrite in this disease. According to equation coefficients logit model is as follows: According to Logit model, it seems that for every degree change in temperature and pH of water, morbidity change will diminish 0.37 % and 1.74 % respectively. 80.56% of fish sampled that had the clinical symptoms, was ranging from an average weight of 5.1 gr (fry) and 417 gr (grower fish), that despite having clinical signs of the disease were negative Streptococcosis. Isolation of Staphylococcus bacteria as well as Gram-negative bacilli from fish with clinical symptoms similar to the symptoms of Streptococcosis, may indicate the involvement of other pathogens in fish clinical signs

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Estimation of physiologic ability and surgical stress (E-PASS) as a predictor of immediate outcome after elective abdominal aortic aneurysm surgery

Background The Estimation of Physiologic Ability and Surgical Stress (E-PASS) score was designed on the premise that the balance between the patient’s physiologic reserve capacity and the surgical stress inflicted at operation was important in the occurrence of postoperative complications. The aim of this study was to assess its value in predicting mortality and morbidity after open elective abdominal aortic aneurysm (AAA) repair. Methods E-PASS data items were collected prospectively in a group of 204 patients undergoing elective open AAA repair over a 6-year period. The operative morbidity and mortality rates were compared with the preoperative risk score (PRS), surgical stress score (SSS) and comprehensive risk score (CRS) of E-PASS. The group comprised 180 (88%) males and the median age was 73 (range 44 to 86) years. Results There were 13 (6%) deaths and 121 (59%) experienced a postoperative complication. As the PRS, SSS and CRS increased, the incidence of postoperative morbidity and mortality significantly increased (P < .0001). Overall mean CRS was .52 (±.27). Mean CRS in the groups of patients who survived and died were .49 (±.24) and .98 (±26), respectively. PRS, SSS, and CRS all had extremely good predictive power for both mortality and morbidity as demonstrated by high areas under the receiver operator curve (range .799 to .953). CRS also showed a strong statistically significant association with the severity of postoperative complication (P < .0001) and length of hospital stay (P < .0001). Conclusions The E-PASS model appears to be a promising method of predicting death and the development of postoperative complications in patients undergoing elective open AAA surgery. It requires further validation in arterial surgery at different geographical locations