Far infrared transmission spectroscopy of binary semiconductors

The far infrared optical properties of a selection of binary semiconductors have been studied by the technique of dispersive Fourier transform spectroscopy. A commercial modular Michelson interferometer has been rebuilt in a single pass dispersive mode for this work. The performance of the instrument has been substantially improved by mounting the moving mirror on a pneumatically controlled precision linear slide to provide a smooth travel. The interferogram was sampled internally by monitoring the interference fringes derived from a secondary He-Ne laser channel. Precision alignment maximises the throughput signal enabling a relatively small specimen to be studied. Direct measurements of the amplitude and phase transmission spectra of GaP, GaAs, InSb, InAs and ZnSe have been performed at room temperature and 100K for the first time. The single-pass configuration has enabled new optical constant data to be obtained accurately on either side of the reststrahlen band. In most cases, these are the first reported results at the two temperatures. In each case the absorption coefficient and the complex dielectric response functions have also been calculated. Prominent features in the spectra are assigned as phonon-combination bands with the aid of critical point phonon frequencies derived from a lattice dynamical model. The magnitude of the imaginary part of the anharmonic self-energy function of the zone-centre transverse optical phonon required to account fully for the observed absorption has been estimated. The results give a clear indication of the range of validity of the anharmonic mechanism and the onset of lattice absorption due to non linear terms in the dipole moment expansion. <p

Determination of optimum combination of voxel size and b-value for brain diffusion tensor imaging

Optimum combination of voxel size resolution and b-value for whole brain imaging has been determined. Data images were acquired using a 1.5T magnetic resonance imaging (MRI) system (GE Signa HDxt). Diffusion tensor imaging (DTI) scan was performed on phantom and a human volunteer. Six protocols which consist of various combination of voxel size and b-value were evaluated. Measurement of signal-to-noise ratio (SNR) and DTI parameter indices were carried out for both phantom and in-vivo studies. Due consideration was given to a combination of parameters yielding sufficient SNR with DTI values comparable to those obtained from previous reported studies. For the phantom study, SNR ≥ 20 was found in all of the protocols except for a combination of voxel size of 2.0 × 2.0 × 2.0 mm3 with b-value of 1200 s/mm2 (V2.0 B1200) and that of voxel size of 2.0 × 2.0 × 2.0 mm3 with b-value of 1000 s/mm2 (V2.0 B1000). For in-vivo study, all protocols presented SNR > 20. It was found that a combination of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 1000 s/mm2 (V2.5 B1000) and that of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 700 s/mm2 (V2.5 B700) displayed the most comparable ADC and FA values with references. In terms of anatomic coverage, V2.5 B700 was found better than V2.5 B1000 as it assures coverage of the whole brain. In conclusion, a combination of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 700 s/mm2 was considered as optimum parameters for brain DTI

Optimization of number of scans for a sparse temporal sampling (STS) functional magnetic resonance imaging (fMRI)

High sensitivity signal detection for a sparse temporal sampling (STS) functional magnetic resonance imaging (fMRI) is compensated by the increase in the number of scans (Ns) and consequently the scan time. A long scan time would result in fatigue and restlessness in participants, while a short scan time is undesirable for an STS-fMRI due to insufficient Ns for averaging. The purpose of this study was to determine the Ns practically sufficient for a sparse fMRI study. Eighteen participants were presented with white noise during a sparse fMRI scan. The height extent of activation was determined via t statistics and region of interest (ROI) based percentage of signal change (PSC). The t statistics and PSC for Heschl’s gyrus (HG) and superior temporal gyrus (STG) during which the participants listened to the white noise were calculated for different number of scans which were 6, 12, 18, 24, 30 and 36. The t statistics and PSC values calculated for the bilateral HG and STG qualitatively indicated a minimal change over Ns = 12 to 36. Both ROIs showed a consistent common right lateralization of activation for all Ns, indicating the right-hemispheric dominance of auditory cortex in processing white noise stimulus. It was proposed that for a sparse fMRI study, Ns may practically fall between 12 and 36

Effect Of Functional Endoscopic Sinus Surgery To The Flow Behavior In Nasal During Resting Breathing Condition

Functional endoscopic sinus surgery is a surgery to remove uncinate process in order to restore sufficient sinus ventilation and drainage in nasal. However, there were a few cases wit11 side effects such as facial pain, reduction in sense of smell and sinusitis reoccurrence of infection. In this study, the effect of uncinate process removal is investigated. Images of the model were done through computational technique and then the flow was simulated to predict the effect of the removal. Inhalation processes with resting breathing condition were modeled. The results &how that smooth flow was observed at nasal area which indicates successful surgical process. However for post FESS model the result shows that the possibilities of sinusitis reoccurrence of infection were high. Finally, velocity profile in the olfactory area show non-favorabIe flow condition for effective smell senses

Effect Of Functional Endoscopic Sinus Surgery To The Flow Behavior In Nasal During Resting Breathing Condition

Functional endoscopic sinus surgery (FESS) is a surgery to removeuncinate process in order to restore sufficient sinus ventilation and drainagein nasal. However, there were a few cases with side effects such as facialpain, reduction in sense of smell and sinusitis reoccurrence of infection. Inthis study, the effect of uncinate process removal is investigated. Images ofthe model were done through computational technique and then the flowwas simulated to predict the effect of the removal. Inhalation processes withresting breathing condition were modeled. The results show that smoothflow was observed at nasal area which indicates successful surgical process.However for post FESS model the result shows that the possibilities ofsinusitis reoccurrence of infection were high. Finally, velocity profile in theolfactory area show non-favorable flow condition for effective smell senses

Covid-19's impact on the physical environments of people with intellectual disabilities: a systematic literature review

COVID-19 pandemic is a public health issue. From 2019 to 2022, 4.5 million people died from the COVID-19 epidemic. Consequently, COVID-19 has put a significant strain on every single creature in this world. COVID-19 has been associated with lockdown, thus resulting in lockdown related inequities towards most people in this world, with unanticipated consequences for people with disabilities. Building in this debate, this paper aimed to discuss on the impacts of COVID-19 on the physical health of People with Intellectual Disabilities. Based on the Prisma protocol, this systematic literature review examined 28 publications from Web Sources of Science and Scopus.The study identified three themes regarding the impact of COVID-19 on the physical environment of people with intellectual disabilities namely mental health, social isolation, severe health problems, socioeconomic and psychology. This study has significant implications in understanding how PWID are impacted by COVID 19 and urged that early preventative measures should be taken since People with Intellectual Disabilities are considered a vulnerable population, therefore it is crucial to ensure that their health status are sustained

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Effect of anastomosis angle on hemodynamic of side-to-end radiocephalic arteriovenous fistula (RCAVF)

Radiocephalic arteriovenous fistula (RCAVF) at wrist is the chosen access for hemodialysis. Most studies describe access complications without considering the effect of the anastomosis angle. In the present investigation, eighteen three-dimensional, simplified models of RCAVF were used to analyze the hemodynamic effect of anastomosis angle under fixed flow rate of 900 ml/min, corresponding to Reynolds number 950. EFD. Lab software was used in the flow simulation with steady flow conditions. The results show that high pressure drop was observed for RCAVF with smaller anastomosis angle. However, for cases with anastomosis angle larger than 45°, pressure drop became relatively constant. The results also show that large vortices appeared in cases with angle smaller than 30°. For cases with angle larger than 60°, low flow zone appeared at the inner wall that may lead to promotion of intimal thickening and formation of stenosis. Overall, for average flowrate, it is recommended that anastomosis angle should be maintained between 45° and 60° to minimize adverse effects

Effect of anastomosis angle on hemodynamic of side-to-end radiocephalic arteriovenous fistula (RCAVF)

Radiocephalic arteriovenous fistula (RCAVF) at wrist is the chosen access for hemodialysis. Most studies describe access complications without considering the effect of the anastomosis angle. In the present investigation, eighteen three-dimensional, simplified models of RCAVF were used to analyze the hemodynamic effect of anastomosis angle under fixed flow rate of 900 ml/min, corresponding to Reynolds number 950. EFD. Lab software was used in the flow simulation with steady flow conditions. The results show that high pressure drop was observed for RCAVF with smaller anastomosis angle. However, for cases with anastomosis angle larger than 45°, pressure drop became relatively constant. The results also show that large vortices appeared in cases with angle smaller than 30°. For cases with angle larger than 60°, low flow zone appeared at the inner wall that may lead to promotion of intimal thickening and formation of stenosis. Overall, for average flowrate, it is recommended that anastomosis angle should be maintained between 45° and 60° to minimize adverse effects