2,009 research outputs found
Implantation of a Bi-Ventricular Pacing System in the Setting of Dextrocardia with Situs Inversus Totalis
Dextrocardia with situs inversus totalis is a rare disorder but is frequently associated with anomalous venous return. Pacemaker/Internal Cardioverter Defibrillator implantation in this population can be difficult given the difficult venous anatomy. This case illustrates how beforehand knowledge of the venous anatomy by cardiac MRI can facilitate device implantation
Clustering of solutions in the random satisfiability problem
Using elementary rigorous methods we prove the existence of a clustered phase
in the random -SAT problem, for . In this phase the solutions are
grouped into clusters which are far away from each other. The results are in
agreement with previous predictions of the cavity method and give a rigorous
confirmation to one of its main building blocks. It can be generalized to other
systems of both physical and computational interest.Comment: 4 pages, 1 figur
Beneficial physiological effects with blackcurrant intake in endurance athletes
Blackcurrant contains anthocyanins, known to influence vasorelaxation and peripheral blood flow. We examined the effects of 7 days intake of Sujon New Zealand blackcurrant powder (6g/day) on the lactate curve, maximum oxygen uptake, and cardiovascular responses at rest and during cycling. Thirteen trained triathletes with >3 yrs experience (8 men, age: 38±8 yrs, body mass: 71±9 kg, BF%: 19±5%, mean±SD) performed two incremental cycling protocols with recording of physiological and cardiovascular responses (Portapres® Model 2). Cardiovascular function was also measured in rest. Experimental design was double-blind, placebo-controlled, randomized and cross-over (wash-out 4 wks). Data was analysed with two-tailed t-tests and 2-way ANOVA and significance accepted at p<0.05. Plasma lactate was lower at 40%, 50%, 60% and 70% of maximum power by 27%, 22%, 17% and 13%. Intensity at 4 mmol∙L-1 OBLA was 6% higher with blackcurrant without effect on heart rate and oxygen uptake. Maximum values of oxygen uptake, heart rate and power were not affected by blackcurrant, but obtained with 14% lower lactate. In rest, blackcurrant increased stroke volume and cardiac output by 25% and 26%, and decreased total peripheral resistance by 16%, with no changes in blood pressure and heart rate. Cardiovascular responses during exercise at 40%, 50%, 60%, 70% and 80% intensity were not affected. Sujon New Zealand blackcurrant powder affects lactate production and/or clearance during exercise. Sujon New Zealand blackcurrant powder affects physiological and cardiovascular responses in rest and during exercise that may have implications for exercise performance
Increasing Onshore Oil Production: An Unexpected Explosion in Trauma Patients
Introduction. Few data currently exist which are focused on typeand severity of onshore oil extraction-related injuries. The purposeof this study was to evaluate injury patterns among onshore oil fieldoperations.
Methods. A retrospective review was conducted of all traumapatients aged 18 and older with an onshore oil field-related injuryadmitted to an American College of Surgeons-verified level 1 traumacenter between January 1, 2003 and June 30, 2012. Data collectedincluded demographics, injury severity and details, hospital outcomes,and disposition.
Results. A total of 66 patients met inclusion criteria. All patientswere male, of which the majority were Caucasian (81.8%, n = 54)with an average age of 36.5 ± 11.8 years, injury severity score of 9.4 ±8.9, and Glasgow Coma Scale score of 13.8 ± 3.4. Extremity injurieswere the most common (43.9%, n = 29), and most were the resultof being struck by an object (40.9%, n = 27). Approximately onethirdof patients (34.8%, n = 23) were admitted to the intensive careunit. Nine patients (13.6%) required mechanical ventilation while27 (40.9%) underwent operative treatment. The average hospitallength of stay was 5.8 ± 16.6 days, and most patients (78.8%, n = 52)were discharged home. Four patients suffered permanent disabilities,and there were two deaths.
Conclusions. Increased domestic onshore oil production inevitablywill result in higher numbers of oil field-related traumas. By focusingon employees who are at the greatest risk for injuries and by targetingthe main causes of injuries, training programs can lead to a decreasein injury incidence. Kans J Med 2018;11(2):34-37
Measurements of Si Hybrid CMOS X-Ray Detector Characteristics
The development of Hybrid CMOS Detectors (HCDs) for X-Ray telescope focal
planes will place them in con- tention with CCDs on future satellite missions
due to their faster frame rates, flexible readout scenarios, lower power
consumption, and inherent radiation hardness. CCDs have been used with great
success on the current generation of X-Ray telescopes (e.g. Chandra, XMM,
Suzaku, and Swift). However their bucket-brigade read-out architecture, which
transfers charge across the chip with discrete component readout electronics,
results in clockrate limited readout speeds that cause pileup (saturation) of
bright sources and an inherent susceptibility to radiation induced displacement
damage that limits mission lifetime. In contrast, HCDs read pixels with low
power, on-chip multiplexer electronics in a random access fashion. Faster frame
rates achieved with multi-output readout design will allow the next
generation's larger effective area telescopes to observe bright sources free of
pileup. Radiation damaged lattice sites effect a single pixel instead of an
entire row. Random access, multi-output readout will allow for novel readout
modes such as simultaneous bright-source-fast/whole-chip-slow readout. In order
for HCDs to be useful as X-Ray detectors, they must show noise and energy
resolution performance similar to CCDs while retaining advantages inherent to
HCDs. We will report on readnoise, conversion gain, and energy resolution
measurements of an X-Ray enhanced Teledyne HAWAII-1RG (H1RG) HCD and describe
techniques of H1RG data reduction.Comment: 11 pages, 10 figure
Biological and functional evaluation of a novel pyrolytic carbon implant for the treatment of focal osteochondral defects in the medial femoral condyle: assessment in a canine model
Increased ocular lens density in HIV-infected individuals with low nadir CD4 counts in South Africa: evidence of accelerated aging.
BACKGROUND: HIV infection is thought to be associated with an increased risk of age-related morbidity and premature aging. Lens density increases with age and may function as a biomarker of aging. The relationship of lens density measurements with clinical and demographic characteristics in HIV-infected individuals in comparison with a matched population of HIV-seronegative individuals was investigated. METHODS: Case-control study of 490 adults aged greater than or equal to 30 years composed of 242 HIV-infected adults and 248 age- and sex-matched HIV-seronegative individuals. Lens density was assessed using lens densitometry (Pentacam) imaging. Measurements were divided into quartiles, and comparison of HIV status and HIV-related factors was assessed by multivariate and multinomial logistic regression. RESULTS: The mean age was 41.2 years in HIV-infected adults and 42.3 years in HIV-seronegative individuals (P = 0.14). Of the HIV-infected adults, 88% were receiving antiretroviral therapy (ART) (median duration, 58 months), and within this group, their median CD4 count was 468 cells per microliter and 84% had undetectable viral load. Although adjusted lens densities were similar by HIV serostatus, participants on ART and who had nadir CD4 counts less than 200 cells per microliter had a higher risk of high lens density compared with HIV-seronegative individuals (P trend = 0.04). Lens density was weakly associated with detectable HIV viremia despite ART, but not with current CD4 count. CONCLUSIONS: HIV-infected individuals on ART with nadir CD4 counts <200 cells per microliter had increased risk of higher lens density. Lens density may represent a novel biomarker of aging, providing insight into accelerated aging trajectories in HIV infection
Study protocol. A prospective cohort study of unselected primiparous women: the pregnancy outcome prediction study.
BACKGROUND: There have been dramatic changes in the approach to screening for aneuploidy over the last 20 years. However, the approach to screening for other complications of pregnancy such as intra-uterine growth restriction, pre-eclampsia and stillbirth remains largely unchanged. Randomised controlled trials of routine application of high tech screening methods to the general population have generally failed to show improvement in outcome. We have previously reviewed this and concluded it was due, in large part, to poor performance of screening tests. Here, we report a study design where the primary aim is to generate clinically useful methods to screen women to assess their risk of adverse pregnancy outcome. METHODS/DESIGN: We report the design of a prospective cohort study of unselected primiparous women recruited at the time of their first ultrasound scan. Participation involves serial phlebotomy and obstetric ultrasound at the dating ultrasound scan (typically 10-14 weeks), 20 weeks, 28 weeks and 36 weeks gestation. In addition, maternal demographic details are obtained; maternal and paternal height are measured and maternal weight is serially measured during the pregnancy; maternal, paternal and offspring DNA are collected; and, samples of placenta and membranes are collected at birth. Data will be analysed as a prospective cohort study, a case-cohort study, and a nested case-control study. DISCUSSION: The study is expected to provide a resource for the identification of novel biomarkers for adverse pregnancy outcome and to evaluate the performance of biomarkers and serial ultrasonography in providing clinically useful prediction of risk
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Membranous Glomerulonephritis With Crescents.
INTRODUCTION: Membranous glomerulonephritis (MGN) is rarely associated with necrotizing and crescentic glomerulonephritis (NCGN). METHODS: We report the clinical and pathologic findings in 15 patients with MGN and NCGN associated with anti-neutrophil cytoplasm antibodies (ANCAs), anti-glomerular basement membrane (GBM), or anti-phospholipase A2 receptor (PLA2R) antibodies. RESULTS: The cohort consisted of 15 patients: 7 males and 8 females with a median age of 63 years (range: 18-79). In 12 of 15 patients, MGN and NCGN were diagnosed at the time of the biopsy, and in 3 cases, MGN predated the NCGN. ANCA was positive in 7 cases (6 MPO myeloperoxidase (MPO)-ANCA and 1 PR3-ANCA), anti-GBM antibodies were detected in 5 cases, and anti-PLA2R antibodies were found in 2 cases. One case was negative for all antibodies. Microscopic hematuria was present in all but one patient who was anuric, and median urinary protein-to-creatinine ratio was 819.5 mg/mmol (range: 88-5600). Pathologic evaluation revealed MGN and NCGN with crescents involving 28% of glomeruli (median; range: 5%-100%). Follow-up was available for all 15 patients; all were treated with steroids; 10 with cyclophosphamide, and 6 also received rituximab. At a median follow-up of 72 months, 9 had stabilization or improvement of renal function, 6 had progressed to end-stage renal disease, and 4 died during the follow-up period. CONCLUSION: MGN with crescents associated with ANCAs or anti-GBM antibodies is a rare dual glomerulopathy. Patients present with heavy proteinuria, microscopic hematuria, and acute kidney injury and should be treated for a rapidly progressive glomerulonephritis. Prognosis is variable, and 40% of patients progress to end-stage renal disease
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A Lower Maternal Cortisol-to-Cortisone Ratio Precedes Clinical Diagnosis of Preterm and Term Preeclampsia by Many Weeks.
CONTEXT: Previous studies have shown reduced placental levels of 11-β-hydroxysteroid dehydrogenase type 2 (11βHSD2) in preeclampsia (PE). However, it is unknown if the maternal cortisol-to-cortisone ratio is predictive of placental complications of pregnancy. OBJECTIVE: To determine the relationship between the maternal serum cortisol-to-cortisone ratio at different stages of pregnancy and the risk of PE or fetal growth restriction (FGR). DESIGN: Women from the Pregnancy Outcome Prediction Study experiencing PE (n = 194) or FGR (n = 185), plus a random sample of healthy controls (n = 279), were studied. Steroids were measured at ∼12, ∼20, ∼28, and ∼36 weeks of gestational age (wkGA). Separate analyses were performed for outcomes with term or preterm delivery. Associations were modeled using logistic regression. RESULTS: At 28 wkGA, the cortisol-to-cortisone ratio was negatively associated (OR per 1 SD increase, 95% CI)] with preterm PE (OR 0.33, 95% CI 0.19 to 0.57), term PE (OR 0.61, 95% CI 0.49 to 0.76), and preterm FGR (OR 0.50, 95% CI 0.29 to 0.85). At 36 wkGA, the cortisol-to-cortisone ratio was negatively associated with term PE (OR 0.42, 95% CI 0.32 to 0.55) but not term FGR (OR 1.07, 95% CI 0.87 to 1.31). Associations were not materially affected by adjustment for maternal characteristics. CONCLUSIONS: A lower maternal serum cortisol-to-cortisone ratio precedes clinical manifestation of PE and preterm FGR by many weeks, despite previous reports of reduced levels of placental 11βHSD2 in these conditions. Our observations implicate enhanced maternal 11βHSD2 activity or reduced 11βHSD type 1 activity in the pathophysiology of PE.The POP study was funded by the National Institute for Health Research (NIHR) Cambridge Comprehensive Biomedical Research Centre (Women’s Health theme), and a project grant from the Medical Research Council (United Kingdom; G1100221). The study was also supported by GE Healthcare (donation of two Voluson i ultrasound systems for the POP study), and by the NIHR Cambridge Clinical Research Facility, where all research visits took place. A.E.H. was an Academic Clinical Fellow funded by NIHR
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