Turbulent boundary layer on a rough surface with pressure gradient and surface heating

Imperial Users onl

Application of near infrared spectroscopy for evaluation of liver oxygenation and function

There is no readily available technique for measurement of liver oxygenation and function. Near infrared spectroscopy (NIRS) is a non-invasive technique originally developed for measuring cerebral oxygenation. This thesis has investigated its application for measurement of changes in hepatic tissue oxygenation and function. A new algorithm was developed for the hepatic application of NIRS. It was validated by comparing tissue oxygenation changes measured by NIRS with hepatic vein oxygenation in pigs. A significant correlation was found between hepatic vein oxygen partial pressure and hepatic oxyhaemoglobin (HbO2), deoxyhaemoglobin (Hb), and cytochrome oxidase (Cyt Ox) (r = 0.87, -0.86, and 0.91, respectively). NIRS measurement of Cyt Ox changes as an indicator of the intracellular tissue oxygenation correlated (r= 0.91) with cellular adenosine triphosphate levels measured by magnetic resonance spectroscopy. A possible role for NIRS in monitoring hepatic blood flow was investigated in pigs by correlating liver tissue oxygenation and blood volume measured by NIRS with hepatic artery and portal vein blood flow. Changes to liver blood inflow were immediately reflected by alterations in liver tissue oxygenation and blood volume. With hepatic artery occlusion there was a significant decrease in Hb02 and total haemoglobin (HbT). Portal vein occlusion caused a greater reduction in Hb02 and HbT with a significant decrease in Cyt Ox. Total occlusion caused a further a decrease in Hb02 and HbT with a significant decrease in Cyt Ox. To investigate the possible role of NIRS in evaluating liver dysfunction, a rabbit model of ischaemia reperfusion (I/R) injury was used. Changes in hepatic Hb02 correlated with reduced flow in the hepatic microcirculation (HM) (r = 0.94). HbO2 changes correlated with the hepatocellular injury as shown by serum ALT, AST, and LDH (r = 0.89, 0.81 and 0.77, respectively). Also, HbO2 changes correlated with the reduction in the bile volume (r = -0.91). Intracellular oxygenation as reflected by changes of Cyt Ox correlated with HM changes (r = 0.93). A significant correlation was found between the Cyt Ox and serum ALT, AST, and LDH (r = 0.97, 0.90, and 0.85, respectively). Also, Cyt Ox correlated significantly with bile volume (r = -0.93). NIRS can measure hepatic indocyanine green (ICG) and this was studied in different animals models. In a rabbit model of acute hepatic dysfunction, ICG uptake rate correlated significantly with total hepatic blood flow (THBF) and HM (r = 0.79 and 0.59, respectively). In a rabbit l/R model, ICG excretion rate correlated with serum ALT, AST, and LDH (r = -0.73, -0.61, and -0.56, respectively) and bile volume (r = 0.83). In a rabbit model of fatty liver ICG rate of uptake correlated with THBF (r = 0.94) and HM (r = 0.96) and its excretion rate correlated with serum bilirubin (r = -0.89), ALT (r = -0.87), AST (r = -0.90), and albumin (r = 0.95). In conclusion NIRS can be used to monitor changes in hepatic tissue oxygenation and function. This technique has potential for clinical application in liver surgery and transplantation for evaluating hepatic tissue viability

Compact modeling of multiple gate mos devices.

Aquesta tesi doctoral presenta models analítics electrostàtics i de transport de diferents tipus de transistors MOSFET de porta múltiple: Double-Gate (DG) MOSFET, Gate-All-Around MOSFETs i FinFETs.Les estructures de porta múltiple són les més adequades per aconseguir la miniaturització dels circuits CMOS per sota dels 50 nm de longitud de canal. La reducció del tamany implica més velocitat i més densitat de circuits a un xip, però també dóna lloc a problemes (efectes de canal curt) que empitjoren les prestacions dels transistors; aquests problemes es deuen a un control més deficient del canal per la porta, que causa un augment del corrent de fuites (degradant la relació on/off del corrent) i disminució de la resistència de sortida (degradant el guany). Amb les estructures de porta múltiple el control electrostàtic del canal per la porta augmenta considerablement i els efectes de canal curt es redueixen dràsticament.El disseny de circuits nanomètrics necessita models acurats dels dispositius MOS de porta múltiple. A més, els models han d'ésser analítics, de manera que els puguin utilitzar els simuladors de circuits, amb temps de simulació petits i sense problemes de convergencia.Aquesta tesi presenta models analítics dels transistors multi-gate MOSFETs, tant per al comportament electrostàtic com pels mecanismes de transport. L'electrostàtica ha estat modelada a partir de l'equació de Poisson en 2 o 3 dimensions. S'han desenvolupat tècniques per resoldre analíticament l'equació de Poisson. El fet de què els models es derivin d'una anàlisi bidimensional o tridimensional fa que els efectes de canal curt s'incloguin de manera física, sense paràmetres empírics. Els models analítics resultants s'han comparat amb simulacions numèriques bidimensionals i tridimensionals, i s'ha observat una concordància quasi perfecta fins als 20 nm de longitud de canal. En el cas del FinFET, a més, s'ha pogut realitzar una comparació amb mesures experimentals, que ha resultat bastant exitosa.Aquesta tesi està recolzada per un total 7 articles publicats o acceptats a revistes internacionals, i dos més d'enviats.En esta tesis hemos estudiado las características de los dispositivos MOSFET nodopados de puerta múltiple (multiple-gate MOSFETs), con dimensiones nanométricas.Hemos introducido modelos compactos de los efectos de canal corto (SCEs) para trestipos de dispositivos MOS de puerta múltiple (surrounding-gate MOSFET, double-gateMOSFET, y FinFET). Se han conseguido modelar los principales parámetros afectadospor los efectos de canal corto. Este trabajo supone un avance muy importante en el modelado de los nuevosdispositivos nanométricos MOS de puerta múltiple. Una buena prueba de ello es que lamayor parte de los resultados presentados en esta tesis se han publicado (o estánaceptados para publicación) en prestigiosas revistas internacionales y en actas decongresos internacionales de reconocido prestigio

Correlates of Missed Nursing Care in Selected Medical Intensive Care Units, Egypt

Background: Missed nursing care is a universal phenomenon that could threaten patient safety across all countries and cultures, Missed nursing care is practiced by registered nurses, licensed vocational nurses, and nurses' aides alike. Therefore, when nursing care is not completed, the quality of care that follows is reduced. Aim: The current study was conducted to determine the correlates of missed nursing care in selected medical intensive care units. Design: Descriptive correlational design was utilized to carry out the study. Setting: The study was conducted in six medical intensive care units at EL Kasr El Ainy hospital and El Manial University hospital. Sample: included a convenience sample of (n = 73) staff nurses working at the selected units. Tools: Data were collected by using modified MISSCARE self-reporting questionnaire. Results: The findings of the study revealed that, the majority of staff nurses reported that they never missed the elements of missed nursing care. Meanwhile the most reported factors contributed to missed nursing care were related to patient, hospital system and polices followed by factors related to nursing staff. Recommendations: the current study recommended that the staff nurses need to realize the importance of reporting the factors that produce obstacles in providing adequate nursing care in addition, the importance to report and disclose the elements of nursing care being missed, ensuring that each nurse is assigned a manageable patient load to render all the needed care and maintaining adequate supplies and well working equipment enable muses to provide higher quality of nursing care. Keywords: Correlates, Missed Nursing Care, Medical Intensive Care Unit

Impact of increasing dietary oil concentrations with a constant energy level on the tolerance of broiler chickens to a high ambient temperature

Broiler males (n= 140) were used in a straight-run experimental design and distributed randomly among four treatment groups with seven replicates per treatment and five broilers per replicate. During 21–42 d old, the chickens were fed iso-caloric and iso-nitrogenous diets containing four levels of dietary vegetable oils (DVO), of 2.7, 4, 6 and 8%. During d 25–27, 31–33, and 38–40 of age, broilers were exposed to heat stress for 4 h a day (1000–1400 h) at 34 ºC, 70–75 % relative humidity. Feeding an 8% DVO diet significantly increased body weight gain compared to the other DVO levels. The feed conversion ratio, protein conversion ratio, metabolizable energy conversion ratio and European production index were significantly enhanced due to feeding an 8% DVO diet compared to a diet containing 6% DVO. Feeding 8% DVO significantly increased the meat protein and lipid percentages, compared to the control group (2.7 % DVO), but decreased the plasma low-density lipoprotein, very-low-density lipoprotein and lymphocytes. Feeding 8% DVO significantly increased the mean cell volume and mean cell hemoglobin, and bursa weight and percentage compared to the control. In addition, 6 and 8% DVO significantly increased the plasma total antioxidant capacity compared to the control group, but decreased the malondialdehyde. Thus, broilers fed a diet containing 8% DVO have an increased tolerance to heat stress, as evidenced by increasing the productive performance, meat quality, blood hematological and biochemical traits, antioxidants and immunity

Using Literature in Pedagogical Contexts as a Solution for the EFL Learners’ Problems in Sudan

This paper is an attempt to answer several open-ended questions regarding the pedagogical values of the exploitation of literature in promoting EFL learning at the different educational levels in the Sudan. These answers are grounded on a system of research methods which have recently been introduced by the new trends in stylistics. Apart from the introduction and the conclusion, this paper consists of the background of the topic which reviews a number of issues concerning the merits, role, procedures and activities of using literature in EFL contexts. The paper also provides a summary of research in the theories and approaches of literature in EFL contexts. Afterwards, the paper focuses on the tools of the stylistic methods and techniques to be applied in the study of every literary text. Two English poems were specifically selected for placing the stylistic analysis principles in the context of patterns of meaning to be stylistically analyzed. The examples were selected for the investigation of the poetic devices which are commonly used in a literary text. Finally, the paper tries to summarize the pedagogical values gained by poetry stylistic analysis in learning the linguistic aspects of a literary text. This paper focuses on the most effective pedagogical technique and content as a contribution to the quality of education in the Sudan

Screening of Dyslipidemia and Obesity among Children in Zagazig University Hospitals

Background: Westerners are well aware of plasma lipid problems, which are becoming increasingly important in the Middle East. The European Expert Panel has advocated universal screening as a preferable approach of hypercholesterolemia screening as a part of the primary preventive effort. Objective: To assess the relation between dyslipidemia and its risk factors; age and body mass index. Patients and Methods: A cross-sectional study that included 357 of children who visited the Pediatrics General Outpatient Clinic at Zagazig University Hospitals. All subjects were subjected to full history taking, general examination, anthropometric measurements, blood pressure, and laboratory investigations including: non-fasting and fasting lipid profiles. Results: Non-fasting total cholesterol (TC) of ≥ 200 was (14.3%) and < 200 was (85.7%). Non-fasting (LDL) of ≥ 130 was (16.8%) and <130 was (83.2%). HDL category of < 40 was (61.3%) and ≥ 40 was (38.7%). There was no statistically significant difference between age, sex and lipid profiles. There was statistically significant positive correlation between non-fasting triglycerides (TG) and non-fasting HDL and non-fasting non-HDL-C. Conclusion: Obesity was associated with the prevalence of at least one abnormal lipid level. This highlights the importance of paying greater attention to the prevention of cardiovascular disease and obesity in children from an early age