Set-up and evaluation of a mid-infrared reflectometer and investigation of the optical properties of doped tin telluride

A system comprised of a Bomem interferometer and a LT3-110 Heli-Tran cryostat was set up to measure the reflectance of materials in the mid-infrared spectral region. Several tests were conducted to ensure the consistency and reliability of the system. Silicon and Chromium, two materials with well known optical properties were measured to test the accuracy of the system, and the results were found to be in good agreement with the literature. Reflectance measurements on pure SnTe and several Pb and Mn-doped alloys were carried out. These materials were chosen because they exhibit a strong plasma edge in the mid infrared region. The optical conductivity and several related optical parameters were calculated from the measured reflectance. Very low temperature measurements were carried out in the far-infrared on Sn9SMn2Te, and the results are indicative of a spin glass phase at 0.8 K. Resistivity measurements were made at room temperature. The resistivity values were found, as expected, to decrease with increasing carrier concentration and to increase with increasing manganese concentration

Prevalence and Causes of Intrahepatic and Extrahepatic Bile Duct Obstruction among the Jaundiced Patients at Riyadh Hospitals Diagnosed by Ultrasound

The aim of this study was to assess the prevalence and causes of bile duct obstruction among patients with jaundice at the ultrasound departments in Riyadh hospitals. Methods and Results: The study included 525 records of jaundiced patients above 18 years old that were referred to the ultrasound department. Data were collected from PACS (Picture Archiving and Communication System) at three different hospitals in Riyadh. Of 525 adult jaundiced patients, 69 had biliary obstruction, a 13% prevalence. In our study, 38(55.1%) cases of obstruction were caused by stones, 14(20.3%) by tumors, 9(13.0%) by inflammation, 5(7.2%) by a nonfunctioning stent, and 3(4.3%) by pnemobilia. Obstructive jaundice occurred significantly more frequently with increasing age. The study revealed no significant difference between gender and the presence of obstruction. More studies with a larger sample size of obstructive jaundice patients are suggested

Association between Renal Stones Sonographic Findings and Demographic Data among Patients at Riyadh Hospitals, Saudi Arabia

Background: Ultrasound is the primary imaging modality to identify renal stones (RS) in patients with acute flank pain. This study aimed to evaluate the presence, location, and size of RS diagnosed by ultrasound in association with age, gender, and BMI among patients at Riyadh hospitals. Methods and Results: In this case-control study, a total of 250 records (130/52% for males and 120/48% for females) from 2018 to 2019 were reviewed from January to March 2020 at different hospitals in Riyadh. In this study, 150(60%) records of patients with RS and 100(40%) records of patients without RS were collected to evaluate the risk factor for RS formation in the central area of Saudi Arabia. A designed data collection sheet containing all variables (demographic and sonographic) of the study was used. Demographic data included gender, age, and body mass index (BMI). Sonographic data included RS presence (yes, no), RS location (right kidney [RK], left kidney [LK], both kidneys), and RS size (small [1cm]). The study found that RS were more common among males than females (P0.05) Conclusion: Among patients at Riyadh hospitals, females are less affected by RS than males. Gender is a significant risk factor for the development of RS. The effect of BMI is obvious on renal stone location and size

Measurement of glutathione in human brain at 3T using an improved double quantum filter in vivo

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