698 research outputs found
Water Exchange across the Blood-Brain Barrier in Obstructive Sleep Apnea: An MRI Diffusion-Weighted Pseudo-Continuous Arterial Spin Labeling Study
Obstructive sleep apnea (OSA) subjects show brain injury in sites that control autonomic, cognitive, and mood functions that are deficient in the condition. The processes contributing to injury may include altered blood-brain barrier (BBB) actions. Our aim was to examine BBB function, based on diffusion-weighted pseudo-continuous arterial spin labeling (DW-pCASL) procedures, in OSA compared to controls. We performed DW-pCASL imaging in nine OSA and nine controls on a 3.0-Tesla MRI scanner. Global mean gray and white matter arterial transient time (ATT, an index of large artery integrity), water exchange rate across the BBB (Kw, BBB function), DW-pCASL ratio, and cerebral blood flow (CBF) values were compared between OSA and control subjects. RESULTS: Global mean gray and white matter ATT (OSA vs. controls; gray matter, 1.691 ± .120 vs. 1.658 ± .109 second, P = .49; white matter, 1.700 ± .115 vs. 1.650 ± .114 second, P = .44), and CBF values (gray matter, 57.4 ± 15.8 vs. 58.2 ± 10.7 ml/100 g/min, P = .67; white matter, 24.2 ± 7.0 vs. 24.6 ± 6.7 ml/100 g/min, P = .91) did not differ significantly, but global gray and white matter Kw (gray matter, 158.0 ± 28.9 vs. 220.8 ± 40.6 min-1, P = .002; white matter, 177.5 ± 57.2 vs. 261.1 ± 51.0 min-1, P = .006), and DW-pCASL ratio (gray matter, .727 ± .076 vs. .823 ± .069, P = .011; white matter, .722 ± .144 vs. .888 ± .100, P = .004) values were significantly reduced in OSA over controls. OSA subjects show compromised BBB function, but intact large artery integrity. The BBB alterations may introduce neural damage contributing to abnormal functions in OSA, and suggest a need to repair BBB function with strategies commonly used in other fields
Intracranial Aneurysms: Review of Current Treatment Options and Outcomes
Intracranial aneurysms are present in roughly 5% of the population, yet most are often asymptomatic and never detected. Development of an aneurysm typically occurs during adulthood, while formation and growth are associated with risk factors such as age, hypertension, pre-existing familial conditions, and smoking. Subarachnoid hemorrhage, the most common presentation due to aneurysm rupture, represents a serious medical condition often leading to severe neurological deficit or death. Recent technological advances in imaging modalities, along with increased understanding of natural history and prevalence of aneurysms, have increased detection of asymptomatic unruptured intracranial aneurysms (UIA). Studies reporting on the risk of rupture and outcomes have provided much insight, but the debate remains of how and when unruptured aneurysms should be managed. Treatment methods include two major intervention options: clipping of the aneurysm and endovascular methods such as coiling, stent-assisted coiling, and flow diversion stents. The studies reviewed here support the generalized notion that endovascular treatment of UIA provides a safe and effective alternative to surgical treatment. The risks associated with endovascular repair are lower and incur shorter hospital stays for appropriately selected patients. The endovascular treatment option should be considered based on factors such as aneurysm size, location, patient medical history, and operator experience
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Lower Back Injuries in National Collegiate Athletic Association Football Players: A 5-Season Epidemiological Study
Background: Low back injuries are common in collegiate football players and can frequently lead to persistent pain, reinjuries, and time lost from participation. Purpose: To describe the epidemiology of back injuries in National Collegiate Athletic Association (NCAA) football players during the 2009/2010 through 2013/2014 academic years utilizing the NCAA Injury Surveillance Program (ISP) database. Study Design: Descriptive epidemiology study. Methods: A convenience sample of NCAA varsity football teams was utilized to determine the rates and patterns of back injuries as well as to generate national injury estimates. The rates and distribution of back injuries were identified within the context of mechanism of injury, injury chronicity, and time lost from sport. Injury rates were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). Incidence rate ratios were calculated to compare the rates of injury between season, event type, mechanism of injury, injury chronicity, and time lost from sport. Results: Nationally, there were 267 low back injuries reported in the database. These were used to estimate 7076 back injuries over the 5-year period, approximately 82% of which were new injuries. The injuries occurred at a rate of 2.70 per 10,000 AEs. Overall, injuries were 3.12 times more likely to occur in competitions than in practices. Athletes were 4.67 times more likely to sustain a back injury during the preseason compared with the postseason but were 1.41 times more likely to sustain a low back injury during the preseason compared with the regular season. Both contact and noncontact were reported equally as the mechanism of injury (37.8% and 38.3%, respectively), and unspecified low back pain was the most common injury (64.2%). Only 1.6% of patients required surgery for their injury, and the majority of athletes (59.6%) returned to play within 24 hours. Conclusion: There was a relatively high rate of lumbar back injuries at the collegiate level (2.70/10,000 AEs), the majority of which were new injuries. About 18% of reported injuries were reinjuries. Although very few required surgery, a careful examination and work-up should be conducted to evaluate each injury. Regimented physical therapy and reconditioning programs are recommended to avert reinjuries.NCAAOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Crop type identification and spatial mapping using Sentinel-2 satellite data with focus on field-level information
Accurate monitoring of croplands helps in making decisions (for
insurance claims, crop management and contingency plans) at
the macro-level, especially in drylands where variability in cropping
is very high owing to erratic weather conditions. Dryland
cereals and grain legumes are key to ensuring the food and nutritional
security of a large number of vulnerable populations living
in the drylands. Reliable information on area cultivated to such
crops forms part of the national accounting of food production
and supply in many Asian countries, many of which are employing
remote sensing tools to improve the accuracy of assessments
of cultivated areas. This paper assesses the capabilities and limitations
of mapping cultivated areas in the Rabi (winter) season and
corresponding cropping patterns in three districts characterized
by small-plot agriculture. The study used Sentinel-2 Normalized
Difference Vegetation Index (NDVI) 15-day time-series at 10m
resolution by employing a Spectral Matching Technique (SMT)
approach. The use of SMT is based on the well-studied relationship
between temporal NDVI signatures and crop phenology. The
rabi season in India, dominated by non-rainy days, is best suited
for the application of this method, as persistent cloud cover will
hamper the availability of images necessary to generate clearly
differentiating temporal signatures. Our study showed that the
temporal signatures of wheat, chickpea and mustard are easily
distinguishable, enabling an overall accuracy of 84%, with wheat
and mustard achieving 86% and 94% accuracies, respectively. The
most significant misclassifications were in irrigated areas for mustard
and wheat, in small-plot mustard fields covered by trees and
in fragmented chickpea areas. A comparison of district-wise
national crop statistics and those obtained from this study
revealed a correlation of 96%
Interfacial Water Properties in the Presence of Surfactants.
Water, because of its fundamental role in biology, geology, and many industrial applications and its anomalous behavior compared to that of simple fluids, continues to fascinate and attract extensive scientific interest. Building on previous studies of water in contact with different surfaces, in this study, we report results obtained from molecular dynamics simulations of water near hydrophilic and hydrophobic interfaces in the presence of nonionic and ionic amphiphilic molecules, hexaethylene glycol monododecyl ether (C12E6) and sodium dodecyl sulfate (SDS). We elucidate how these surfactants affect the packing (i.e., density profiles) and orientation of interfacial water. The results highlight the interplay of both surfactant charges and the substrate charge distribution predominantly with respect to the orientation of water molecules, up to distances longer than those expected based on simulation results on flat solid surfaces. We also quantify the dynamics of interfacial water molecules by computing the residence probability for water in contact with various substrates. We compare our results to those previously obtained for interfacial water on silica and graphite and also with experimental sum-frequency vibrational spectroscopy results at the air-water interface in the presence of surfactants. Our analysis could be useful for a better understanding of interfacial water not only near solid substrates but also near self-assembled/aggregated molecules at a variety of interfaces
Thermal behaviour of zircon/zirconia-added chemically durable borosilicate porous glass
Macroporous alkali resistant glass has been developed by making additions of zirconia (ZrO2) and zircon (ZrSiO4) to the sodium borosilicate glass system SiO2–B2O3 Na2O. The glass was made using a traditional high temperature fusion process. Differential thermal analysis (DTA) was carried out to identify the glass transition temperature (Tg) and crystallisation temperature (Tx). Based on these findings, controlled heat-treatments were implemented to separate the glass into two-phases; a silica-rich phase, and an alkali-rich borate phase. X-ray diffraction (XRD) was used to identify any crystal phases present in the asquenched and heat-treated glasses. Fourier transform infrared (FTIR) spectroscopy also proved effective in investigating phase separation and crystallisation behaviour. After leaching, a silica-rich skeleton with an interconnected pore structure and a uniform pore distribution was observed. Pore characterisation was carried out using mercury porosimetry. The size and shape of the pores largely depended on the heattreatment temperature and time. ZrO2/ZrSiO4 additions increased the alkali resistance of the porous glass 3–4 times
Germline heterozygous DDX41 variants in a subset of familial myelodysplasia and acute myeloid leukemia
The Brazilian National Council for Scientific and
Technological Development), Bloodwise, Children with Cancer and MRC (Medical
Research Council, UK)
Evaluating Student Performance and Perception of a Workshop Integrating Pharmacy Practice and a Pharmaceutics Lab
Objective: Evaluating Student Performance and Perception of a Workshop Integrating Pharmacy Practice and a Pharmaceutics Lab
Innovation: Common methods for curricular integration are often time and faculty-intensive. An innovative approach to integration was developed and utilized in an introductory compounding workshop. Faculty members collaborated with a compounding pharmacist to design and facilitate a pharmaceutics workshop for first-year pharmacy students. The workshop was composed of four major sections, an introduction to pharmaceutical compounding and the regulations surrounding manufacturing and sterility, a case discussion involving a pediatric patient and the need to develop an appropriate drug delivery system, a short review of pharmaceutical calculations and labeling requirements, and then an introduction to logistics and active learning in a lab setting.
Critical Analysis: After taking part in the workshop, students indicated a significantly higher comfort level going into the pharmaceutics lab (3.48±0.83 to 4.04±0.70) and in the compounding process (3.06±0.83 to 3.71±0.80). Their views of the clinical application of the lab and the need to use knowledge gained from other courses in the lab were also significantly improved (4.36±0.68 to 4.61±0.49 and 3.71±0.77 to 4.26±0.74, respectively). In addition, their perceptions of how they will utilize the skills developed as a practicing pharmacist, and their feelings towards the safety procedures involved in compounding, were also positively affected (3.96±0.87 to 4.45±0.59 and 3.28±0.92 to 3.91±0.72, respectively). Finally, students’ average quiz score in Spring 2016, when the workshop was instituted, significantly increased from Spring 2015 (90.154±4.98 versus 85.89±10.87, respectively).
Article Type: Not
Preoperative Atrial Fibrillation/Flutter Impact on Risk-Adjusted Repeat Aortic Intervention Patients[PROTOCOL]
Aim: Impacts of pre-operative atrial fibrillation or flutter (AF/AFL) upon repeat aortic valve replacement (r-AVR) patients’ risk-adjusted short-term outcomes is unknown.Methods: From 2005-2018, New York State AF/AFL versus non-AF/AFL adults’ risk-adjusted r-AVR outcomes were compared. Primary endpoints included the Society of Thoracic Surgeons’ 30-day operative mortality or major morbidity (MM) composite and 30-day readmission (READMIT); the MM sub-components were secondary endpoints. Multivariable logistic regression models evaluated AF/AFL impact upon these endpoints while holding other factors constant.Results: Of 36,783 adults initially undergoing aortic valve replacement, 334 subsequently underwent r-AVR. Within this r-AVR group, 42.4% of repeat surgical (r-SAVR) patients had AF/AFL; 50.4% of repeat transcatheter (viv-TAVR) patients had AF/AFL. R-SAVR AF/AFL patients were older and had more comorbidities than those without AF/AFL. Viv-TAVR AF/AFL patients were similar to those without AF/AFL except for lower rates of chronic obstructive pulmonary disease. Comparing risk-adjusted r-AVR outcomes, AF/AFL did not impact MM [odds ratio (OR), 95% confidence interval (CI): 1.23, 0.66-2.28, P = 0.512] or READMIT (OR, 95%CI: 1.15, 0.60-2.19, P = 0.681). Black race (OR, 95%CI: 2.89, 1.01-8.32, P = 0.049) and Elixhauser mortality score (OR, 95%CI: 1.07, 1.04-1.10, P < 0.0001) predicted MM risk. Cerebrovascular disease (OR, 95%CI: 2.54, 1.23-5.25, P = 0.012) predicted READMIT risk, while viv-TAVR was protective compared to r-SAVR (OR, 95%CI: 0.44, 0.21-0.91, P = 0.027).Conclusion: AF/AFL was not associated with risk-adjusted short-term r-AVR outcomes. Black race, Elixhauser mortality score, and cerebrovascular disease predicted adverse outcomes
Predictors and Risk-Adjusted Outcomes of New-Onset Postoperative Atrial Fibrillation in Surgical and Transcatheter Aortic Valve Replacement [post-AF rAVR PROTCOL]
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