452 research outputs found
Heliophysics Event Knowledgebase for the Solar Dynamics Observatory and Beyond
The immense volume of data generated by the suite of instruments on SDO
requires new tools for efficient identifying and accessing data that is most
relevant to research investigations. We have developed the Heliophysics Events
Knowledgebase (HEK) to fill this need. The HEK system combines automated data
mining using feature-detection methods and high-performance visualization
systems for data markup. In addition, web services and clients are provided for
searching the resulting metadata, reviewing results, and efficiently accessing
the data. We review these components and present examples of their use with SDO
data.Comment: 17 pages, 4 figure
Solid-State Diffusion Welding of Wrought AISI 304 Stainless Steel to Nimonic AP-1 Superalloy Powder by Hot Isostatic Pressing Dissimilar materials like stainless steels and powder metallurgy superalloys can be joined by diffusion welding using hot isostat
ABSTRACT. The diffusion welding characteristics of wrought AISI 304 stainless steel to a superalloy powder Nimonic AP-1 were examined in this study. After encapsulation, evacuation and degassing, the welds were hot isostatically pressed (HIPed) in two different cycles, i.e., 1200°C (2192°F)/3 h/147 MPa and 1270°C (2318°F)/3 h/121 MPa. A variation in surface condition of stainless steel was also studied for its influence on properties of the joints. These diffusionwelded joints were characterized for diffusion of alloying elements, microstructural features and tensile properties. Most specimens showed good weld strength for both the hot isostatic pressing (HIP) cycles, except specimens with sand blasted surfaces, which gave negligible ductility because of the presence of sand particles embedded on the surface. In general, the tensile properties of the diffusion welded specimens were limited by the mechanical properties of stainless steel and not the joint interface. The microstructural examination of a HIP welded joint showed a thin weld zone of 30-40 ~m. While the stainless steel region of the welded specimen showed a relatively clean structure, the Nimonic AP-1 region showed precipitation of dark particles near the interface extending over 20-60 pm. Electron microprobe analysis of the diffusion welded zone revealed enrichment of titanium-rich particles along prior particle boundaries (PPBs) near the interface. Electron microprobe analysis further revealed extensive diffusion of Ni, Co and AI elements into stainless steel and that of Fe into Nimonic AP-1 superalloy indicating complex composition of the weld interlayer. M. C. SOMANI and N. C. BIRLA, Scientists, are with Defence Metallurgical Research Laboratory, Hyderabad, India, and A. TEKIN is with th
Endovascular control of haemorrhagic urological emergencies: an observational study
BACKGROUND: Transarterial embolisation (TAE) is an effective method in control of haemorrhage irrespective of the nature of urological emergency. As the technique and technology have evolved, it is now possible to perform highly selective embolisation. The aim of this study was to critically appraise feasibility and efficacy of therapeutic TAE in control of haemorrhagic urological emergencies using selective and non-selective embolisation. Specifically, we aimed to assess the impact of timing of embolisation on the requirement of blood transfusion and long-term morphological and functional follow-up of embolised organs. METHODS: This is a single institutional observational study carried out between March 1992 and March 2006. Records of all patients who underwent selective and non-selective angioembolisation to control bleeding in urological emergencies were reviewed. Data on success rate, periprocedural complications, timing of embolisation, requirement of blood transfusion and the long-term morphological and functional outcomes of embolised organs was recorded. RESULTS: Fourteen patients underwent endovascular control of bleeding as a result of trauma, iatrogenic injury and spontaneous perinephric haemorrhage during a period of 14 years. All these patients would have required emergency open surgery without the option of embolisation procedure. The mean time between the first presentation and embolisation was 22 hours (range 30 minutes to 60 hours). Mean pre-embolisation transfusion requirement was 6.8 units (range 0–22 units). None of the patients with successful embolisation required post-procedural blood transfusion. Permanent haemostasis was achieved in all but one patient, who required emergency nephrectomy. There were no serious procedure related post-embolisation complications. CONCLUSION: Endovascular control using transarterial angioembolisation is an effective method for managing haematuria or haemorrhage in urological emergencies. Wherever and whenever indicated, this option should be considered early in the management of these cases
Does age impact outcomes of retrograde intrarenal surgery in the elderly? Results from 366 patients from the FLEXible ureteroscopy outcomes registry (FLEXOR)
Background: There has been a consistent increase in the last decades in prevalence of renal stones in elderly. Aims: To evaluate outcomes of retrograde intrarenal surgery (RIRS) for renal stones in elderly and factors associated with postoperative complications and residual fragments (RFs). Methods: Data from 12 centers were retrospectively reviewed. Inclusion criteria: ≥ 75 years, renal stones only, normal renal anatomy. Patients were divided into three groups; Group 1: patients aged 75–79 years; Group 2: age 80–84 years; Group 3: age ≥ 85 years. Multivariable logistic regression analyses were performed to assess factors associated with perioperative complications, sepsis, and RFs. Results: 366 patients were included. There were 189 patients in Group 1, 113 in Group 2, and 64 in Group 3. There was no difference between groups regarding stone features and total surgical time. Median length of stay was significantly longer in Group 3 (6.0 days, vs 2.0 days in Group 2 vs 2.5 days in Group 1, p = 0.043). There was no significant difference in postoperative complications and RFs between the groups. At multivariable logistic regression analysis, female gender (OR 2.82) and maximum stone diameter (OR 1.14) were associated with higher odds of sepsis, while surgical time (OR 1.12) and the use of a reusable ureteroscope (OR 6.51) with overall complications. Stone size (OR 1.23) was associated with higher odds of RFs. Conclusion: RIRS showed safety and efficacy for kidney stones in elderly patients. Surgical time should be kept as short as possible to avoid higher odds of postoperative complications, particularly in females
Scoping Review of Experimental and Clinical Evidence and Its Influence on Development of the Suction Ureteral Access Sheath
The ureteral access sheath (UAS) has been a boon and a bane in flexible ureteroscopy (FURS), with its merits and demerits well established. Its design and dimensions were instrumental in reshaping the way flexible scopes were used and were key adjuncts to establishing retrograde intrarenal surgery (RIRS) as a standard of care in the endourological management of renal stones. With the ever-changing landscape of RIRS over the decades shaped by technological advancements in lasers and flexible scopes, the UAS has also continuously evolved. The utility of suction in endourology has recently changed the way RIRS is performed and is a game changer for FURS outcomes. With strong clinical and experimental evidence to support its use, the UAS has undergone a transformative change in the recent past, with its ability to monitor intrarenal pressure and provide a superior vacuum-cleaner effect that improves the trifecta of RIRS, namely an improved single-stage stone-free rate (SFR), minimise complications, and reduce reinterventions. Our comprehensive review outlines the key clinical and experimental evidence and traces the developments that were key to modifying the traditional UAS into a flexible and navigable suction ureteric access sheath (FANS) and highlights how the design and modifications, in turn, influence the ability to push the boundaries of RIRS
A comparison of sexual behaviour and attitudes of healthy adolescents in a Danish high school in 1982, 1996, and 2001
AIM: To assess changes in sexual behaviour among students at a high school in Denmark from 1982 to 2001. METHODS: An anonymous self-administered questionnaire was used to compare data from three identical cross-sectional surveys performed in 1982, 1996, and 2001. RESULTS: Girls: More girls reported their first sexual intercourse before their 16th birthday in 2001 (42%) than in 1996 (29%) In 1982 it was also 42% (Chi-square for trend: p = 0.003). Fewer girls with no regular partner used condoms for their personal protection in 2001 (2%) than in 1996 (9%) and 1982 (0%) (Chi-square for trend p = 0.016). The proportion of girls with no regular partner who considered protection from sexually transmitted disease important for their choice of contraception was 39% in 2001 compared with 71% in 1996 and only 10% in 1982 (Chi-square for trend: p < 0.0001). Boys: More boys reported sexual debut before their 16th birthday in 2001 (40%) than in 1996 (37%) and 1982 (24%) (Chi-square for trend: p = 0.023). For boys with no regular partner, condom was preferred for personal protection by 85% in 2001, 91% in 1996 and 61% in 1982 (Chi-square for trend p = 0.007). Protection against sexually transmitted infection declined, especially among boys with no regular partner, from 51% in 2001 to 72% in 1996 and 21% in 1982 Chi-square for trend: p < 0.0001). The tendency towards earlier sexual debut and less use of safe sex practices to protect against sexually transmitted infections (STI) was accompanied by a rise in the number of detected STIs during this period. CONCLUSIONS: The period from 1982 to 1996 during which sexual attitudes were directed toward safer sex seems to have given way to a reverse trend in the period from 1996 to 2001. These findings may have significant implications for health care authorities organising preventive strategies for healthy adolescents
The tyrosine phosphatase CD148 is an essential positive regulator of platelet activation and thrombosis
Platelets play a fundamental role in hemostasis and thrombosis. They are also involved in pathologic conditions resulting from blocked blood vessels, including myocardial infarction and ischemic stroke. Platelet adhesion, activation, and aggregation at sites of vascular injury are regulated by a diverse repertoire of tyrosine kinase–linked and G protein–coupled receptors. Src family kinases (SFKs) play a central role in initiating and propagating signaling from several platelet surface receptors; however, the underlying mechanism of how SFK activity is regulated in platelets remains unclear. CD148 is the only receptor-like protein tyrosine phosphatase identified in platelets to date. In the present study, we show that mutant mice lacking CD148 exhibited a bleeding tendency and defective arterial thrombosis. Basal SFK activity was found to be markedly reduced in CD148-deficient platelets, resulting in a global hyporesponsiveness to agonists that signal through SFKs, including collagen and fibrinogen. G protein–coupled receptor responses to thrombin and other agonists were also marginally reduced. These results highlight CD148 as a global regulator of platelet activation and a novel antithrombotic drug targe
The Spread of HIV in Pakistan: Bridging of the Epidemic between Populations
In the last two decades, ‘concentrated epidemics’ of human immunodeficiency virus (HIV) have established in several high risk groups in Pakistan, including Injecting Drug Users (IDUs) and among men who have sex with men (MSM). To explore the transmission patterns of HIV infection in these major high-risk groups of Pakistan, 76 HIV samples were analyzed from MSM, their female spouses and children, along with 26 samples from a previously studied cohort of IDUs. Phylogenetic analysis of HIV gag gene sequences obtained from these samples indicated a substantial degree of intermixing between the IDU and MSM populations, suggesting a bridging of HIV infection from IDUs, via MSM, to the MSM spouses and children. HIV epidemic in Pakistan is now spreading to the female spouses and offspring of bisexual MSM. HIV control and awareness programs must be refocused to include IDUs, MSM, as well as bisexual MSM, and their spouses and children
Isometric handgrip as an adjunct for blood pressure control: a primer for clinicians
Considered a global health crisis by the World Health Organization, hypertension (HTN) is the leading risk factor for death and disability. The majority of treated patients do not attain evidence-based clinical targets, which increases the risk of potentially fatal complications. HTN is the most common chronic condition seen in primary care; thus, implementing therapies that lower and maintain BP to within-target ranges is of tremendous public health importance. Isometric handgrip (IHG) training is a simple intervention endorsed by the American Heart Association as a potential adjuvant BP-lowering treatment. With larger reductions noted in HTN patients, IHG training may be especially beneficial for those who (a) have difficulties continuing or increasing drug-based treatment; (b) are unable to attain BP control despite optimal treatment; (c) have pre-HTN or low-risk stage I mild HTN; and (d) wish to avoid medications or have less pill burden. IHG training is not routinely prescribed in clinical practice. To shift this paradigm, we focus on (1) the challenges of current HTN management strategies; (2) the effect of IHG training; (3) IHG prescription; (4) characterizing the population for whom it works best; (5) clinical relevance; and (6) important next steps to foster broader implementation by clinical practitioners
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