Numerical Study for Performance Evaluation of Plastic Solar Air Heater with Different Cross-Sectional Configuration

In this research, a numerical investigation was performed on five solar air heaters with different cross-sectional shape to find the best configuration relevant to thermal performance. The selected tested shapes in this study were (circular, semi-circular, half-circle plus isosceles triangle, half circle-negative isosceles triangle shape and crescent shape) and all tested shapes hade the same absorber surface area. The effect of two parameter (velocity and solar radiation intensity) on thermal performance of solar air heater were studied numerically by ANSYS 14.0. The velocity of air was changed from 0.25 to 2.0 (m.s -1 ). Results indicated that the highest efficiencies were accomplished for the circular configuration and reached to about 51.79% at solar radiation intensity 850 (W.m-2 ). The solar radiation intensity was changed from 400 to 1200 (W.m-2 ). Results indicated that the highest efficiencies were accomplished for the circular configuration and reached to about 35.51% at air velocity 1.0 (m.s-1 )

Effect of Experimental Phenylketonuria on the Bone of Pregnant Mothers and Their Young During Perinatal Life and After Delivered Newborn of Albino Rats

Phenylketonuria (PKU) is a genetic disorder that is characterized by an inability of the body to utilize the essential amino acid, phenylalanine. The disease results from a deficiency in phenylalanine hydroxylase, the enzyme catalyzing the conversion of phenylalanine to tyrosine. Although, this inborn error of metabolism was among the first in humans to be understood biochemically and genetically, little is known about the mechanisms involved in the pathology of PKU during neonatal development. Elevated concentrations of plasma phenylalanine were induced in pregnant rats by oral administration of 50mg/100g body weight alpha-methylphenylalanine plus phenylalanine supplementation at a dosage of 60mg/100g body weight two times daily after the 6th day of onset of gestation till 14 & 16 days of gestation as well as at parturition. Treatment with alpha-methylphenylalanine/ phenylalanine resulted in a significant decrease of accumulated body weight gain during pregnancy as well as exhibited marked growth retardation of prenatal fetuses and delivered newborn. The growth retarded fetuses was manifested by decreased body weight, malformed both fore- & hindlimb, oedematous skin & superficial hematomas widely spread in different parts of the body. Ossification of bones was greatly altered. Skeletal abnormalities restricted mainly in skull, sternebrae, lumbar, caudal vertebrae and distal phalanx of both fore- & hindlimb. Histological examination of femoral bone revealed varieties of histopathological abnormalities which illustrated and discussed. These results suggested that exposure of the fetus to high plasma concentrations of phenylalanine cause deformities of bone

Histopathological Effects on the Eye Development During Perinatal Growth of Albino Rats Maternally Treated with Experimental Phenylketonuria During Pregnancy

Phenylketonuria (PKU) is a genetic disorder that is characterized by an inability of the body to utilize the essential amino acid, phenylalanine. The disease results from a deficiency in phenylalanine hydroxylase, the enzyme catalyzing the conversion of phenylalanine to tyrosine. Although, this inborn error of metabolism was among the first in humans to be understood biochemically and genetically, little is known about the mechanisms involved in the pathology of PKU during neonatal brain development. Elevated concentrations of plasma phenylalanine were induced in pregnant rats by oral administration of 50mg/100g body weight alpha-methylphenylalanine plus phenylalanine supplementation at a dosage of 60mg/100g body weight two times daily after 6th day of onset of gestation till 14 & 16 days prenatal as well as at parturition. Treatment with alpha-methylphenylalanine resulted in significant reduction of retinal cell layers of prenatal fetuses and delivered newborns.   Histological abnormalities were detected manifested by either hyaline degeneration of lens structure or inducing lens cataract as well as comparative atrophy of retina associated with the development of Malignant polypoid mass in the ganglionic cell layers in contact with the lens

Study of the Optical Properties of Zno Nano-structure at Different Ti Content

Zinc oxide (ZnO) and TZO samples having different Ti content were synthesized from doping to composite by Citrate sol-gel method (dissolving and react with citric acid) characterized according to their optical properties. The UV - vis characterization exhibiting good optical properties. The results show there are one absorption edge at pure and low Ti doping but at higher Ti% another edge appeared and slightly shifted around 400 nm. The maximum absorption nearly at 350 nm, and the band gap energy of Ti-doped ZnO increase from 3.16 to 3.20 eV achieving a blue-shift. A red shift from 3.07 to 3.19 eV in the visible range which has a very important application, this improves the optical properties of ZnO and gives an indication how to tune its band gap (increase or decrease by doping or composition)

Histopathological Effects on the Eye Development during Perinatal Growth of Albino Rats Maternally Treated with Experimental Phenylketonuria during Pregnancy

Phenylketonuria (PKU) is a genetic disorder that is characterized by an inability of the body to utilize the essential amino acid, phenylalanine. The disease results from a deficiency in phenylalanine hydroxylase, the enzyme catalyzing the conversion of phenylalanine to tyrosine. Although, this inborn error of metabolism was among the first in humans to be understood biochemically and genetically, little is known about the mechanisms involved in the pathology of PKU during neonatal brain development. Elevated concentrations of plasma phenylalanine were induced in pregnant rats by oral administration of 50mg/100g body weight alpha-methylphenylalanine plus phenylalanine supplementation at a dosage of 60mg/100g body weight two times daily after 6th day of onset of gestation till 14 & 16 days prenatal as well as at parturition. Treatment with alpha-methylphenylalanine resulted in significant reduction of retinal cell layers of prenatal fetuses and delivered newborns.   Histological abnormalities were detected manifested by either hyaline degeneration of lens structure or inducing lens cataract as well as comparative atrophy of retina associated with the development of malignant polypoid mass in the ganglionic cell layers in contact with the lens

Effect of Experimental Phenylketonuria on the Bone of Pregnant Mothers and their young during Perinatal Life and after Delivered Newborn of Albino Rats

Phenylketonuria (PKU) is a genetic disorder that is characterized by an inability of the body to utilize the essential amino acid, phenylalanine. The disease results from a deficiency in phenylalanine hydroxylase, the enzyme catalyzing the conversion of phenylalanine to tyrosine. Although, this inborn error of metabolism was among the first in humans to be understood biochemically and genetically, little is known about the mechanisms involved in the pathology of PKU during neonatal development. Elevated concentrations of plasma phenylalanine were induced in pregnant rats by oral administration of 50mg/100g body weight alpha-methylphenylalanine plus phenylalanine supplementation at a dosage of 60mg/100g body weight two times daily after the 6th day of onset of gestation till 14 & 16 days of gestation as well as at parturition. Treatment with alpha-methylphenylalanine/ phenylalanine resulted in a significant decrease of accumulated body weight gain during pregnancy as well as exhibited marked growth retardation of prenatal fetuses and delivered newborn. The growth retarded fetuses was manifested by decreased body weight, malformed both fore- & hindlimb, oedematous skin & superficial hematomas widely spread in different parts of the body. Ossification of bones was greatly altered. Skeletal abnormalities restricted mainly in skull, sternebrae, lumbar, caudal vertebrae and distal phalanx of both fore- & hindlimb. Histological examination of femoral bone revealed varieties of histopathological abnormalities which illustrated and discussed. These results suggested that exposure of the fetus to high plasma concentrations of phenylalanine cause deformities of bone

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases

Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics