6,449 research outputs found
Beneficial effects on pregnancy outcomes of thyroid hormone replacement for subclinical hypothyroidism
Hypothyroidismand raised thyroid antibody levels have been associated with adverse obstetrical outcomes. Several studies have investigated causal associations, but results have been inconsistent and fewstudies have reported the effects of thyroxine replacement therapy on pregnancy outcomes in hypothyroid patients. Objective.The primary study objective was to determine the outcome of pregnancies in women diagnosed with overt and subclinical hypothyroidism (SCH) (serum TSH \u3e 2.5mIU/L) and those with elevated circulating thyroid autoantibody levels in the first trimester of pregnancy and after the institution of appropriate thyroxine replacement therapy to maintain the serum TSH ≤ 2.5mIU/L. Study Design. This prospective observational study was undertaken between 2013 and 2016. Blood samples were taken from 1025 women at presentation for thyroid stimulating hormone (TSH), anti-thyroglobulin antibodies (TGAb), and thyroid peroxidase antibodies (TPOAb).Those with a TSH \u3e 2.5mIU/L were treated with thyroxine andmanaged appropriately to ensure that theTSHwasmaintained ≤2.5mIU/L. Outcomes in these patients were compared to those in euthyroid patients. Maternal antenatal complications and perinatal outcomes were recorded. Results. There were a total of 1025 patients of whom 382 (37.5%) were nulliparous. 10.1% had a TSH level \u3e 2.5mIU/L and 18.2% had at least one raised thyroid antibody level. No differences in adverse outcomes of pregnancy were evident in women treated for SCH or overt hypothyroidism compared to the euthyroid group. There was also no association between raised thyroid antibodies and adverse pregnancy outcomes in either group. Conclusion.There were no adverse outcomes of pregnancy found in pregnant women who had been diagnosed and treated with thyroxine for SCH at the time of presentation when compared to euthyroid patients. There was also no relationship with thyroid antibodies and adverse pregnancy outcomes in the two groups. It is not possible to unequivocally advocate for thyroxine replacement in pregnant women with subclinical and overt hypothyroidism until large scale randomized controlled trials are performed
Studies on the determination of sulfur as barium sulfate
1. The conditions affecting the accuracy of sulfur determination by barium chloride precipitation have been studied, using potassium and sodium sulfates.
2. The effect of sodium, calcium and magnesium salts has been investigated, under conditions approximating those of insecticide analysis.
3. A definite set of conditions is quoted, which if strictly observed, will yield fairly accurate analyses. For more accurate work, a method of checking by analysis of a synthetic solution is advocated.
4. The theory of the contamination of barium sulfate by extraneous substances is discussed, and the experimental data throw further light upon the nature of the adhesion phenomena.
5. An exhaustive bibliography of previous work is appended, together with abstracts of the papers
Parallel quantized charge pumping
Two quantized charge pumps are operated in parallel. The total current
generated is shown to be far more accurate than the current produced with just
one pump operating at a higher frequency. With the application of a
perpendicular magnetic field the accuracy of quantization is shown to be 20
ppm for a current of pA. The scheme for parallel pumping presented in
this work has applications in quantum information processing, the generation of
single photons in pairs and bunches, neural networking and the development of a
quantum standard for electrical current. All these applications will benefit
greatly from the increase in output current without the characteristic decrease
in accuracy as a result of high-frequency operation
A Requirements Analysis for an Integrated Maintenance Information System Application into Theater Air Control System Maintenance
This research was to determine to what extent Integrated Maintenance Information System IMIS functional requirements could satisfy the maintenance information requirements of the ground-based Theater Air Control System. IMIS is a program sponsored by Armstrong Laboratory at Wright-Patterson Air Force Base, Ohio to automate maintenance information. To date, Armstrong Laboratory has only targeted aircraft maintenance for this automated program. The Theater Air Control System contains powerful military radars connected to a mobile communications and computer network. Theater Air Control System maintenance information requirements were identified through a study of the 728th Air Control Squadron at Eglin Air Force Base, Florida, and the existing aircraft requirements matrix for the Integrated Maintenance Information System was modified to meet Theater Air Control System requirements. The small amount of changes required to modify the aircraft matrix in order to satisfy ground TACS requirements indicate that ground TACS is a prime candidate for IMIS technology
Variations in Cholesterol Management Practices of U.S. Physicians
AbstractObjectives. This study sought to evaluate national cholesterol management practices of U.S. physicians.Background. Past studies show that nonclinical factors affect physician practices. We tested the hypothesis that physician and patient characteristics influence cholesterol management.Methods. We used a stratified, random sample of 2,332 office-based physicians providing 56,215 visits to adults in the 1991–1992 National Ambulatory Medical Care Surveys. We investigated physicians’ reporting of cholesterol-related screening, counseling or medications during office visits and used multiple logistic regression to assess independent predictors.Results. An estimated 1.12 billion adult office visits occurred in 1991 and 1992 (95% confidence interval 1.06 to 1.18 billion). For the 1.03 billion visits by patients without reported hyperlipidemia, cholesterol screening (2.8% of visits) and counseling (1.2%) were not frequent. The likelihood of screening increased with older age, cardiovascular disease risk factors, white race and private insurance. We estimate that only 1 in 12 adults received cholesterol screening annually. In the 85 million visits by patients with hyperlipidemia, cholesterol testing was reported in 22.9%, cholesterol counseling in 34.4% and lipid-lowering medications in 23.1%. Testing was more likely in diabetic and nonobese patients. Counseling was more likely with younger age, cardiovascular disease and private insurance. Medications use was associated with cardiovascular disease, Northeast region of the United States, nonobese patients and visits to internists. Physician practices did not differ by patient gender.Conclusions. Although clinical conditions strongly influence cholesterol management, the appropriateness of variations noted by payment source, geographic region and physician specialty deserve further evaluation. These variations and the low estimated volume of services suggest that physicians have not fully adopted recommended cholesterol management practices.(J Am Coll Cardiol 1997;29:139–46)
Caenorhabditis elegans Operons Contain a Higher Proportion of Genes with Multiple Transcripts and Use 3′ Splice Sites Differentially
RNA splicing generates multiple transcript isoforms from a single gene and enhances the complexity of eukaryotic gene expression. In some eukaryotes, operon exists as an ancient regulatory mechanism of gene expression that requires strict positional and regulatory relationships among its genes. It remains unknown whether operonic genes generate transcript isoforms in a similar manner as non-operonic genes do, the expression of which is less likely limited by their positions and relationships with surrounding genes. We analyzed the number of transcript isoforms of Caenorhabditis elegans operonic genes and found that C. elegans operons contain a much higher proportion of genes with multiple transcript isoforms than non-operonic genes do. For genes that express multiple transcript isoforms, there is no apparent difference between the number of isoforms in operonic and non-operonic genes. C. elegans operonic genes also have a different preference of the 20 most common 3′ splice sites compared to non-operonic genes. Our analyses suggest that C. elegans operons enhance expression complexity by increasing the proportion of genes that express multiple transcript isoforms and maintain splicing efficiency by differential use of common 3′ splice sites
Forman's Ricci curvature - From networks to hypernetworks
Networks and their higher order generalizations, such as hypernetworks or
multiplex networks are ever more popular models in the applied sciences.
However, methods developed for the study of their structural properties go
little beyond the common name and the heavy reliance of combinatorial tools. We
show that, in fact, a geometric unifying approach is possible, by viewing them
as polyhedral complexes endowed with a simple, yet, the powerful notion of
curvature - the Forman Ricci curvature. We systematically explore some aspects
related to the modeling of weighted and directed hypernetworks and present
expressive and natural choices involved in their definitions. A benefit of this
approach is a simple method of structure-preserving embedding of hypernetworks
in Euclidean N-space. Furthermore, we introduce a simple and efficient manner
of computing the well established Ollivier-Ricci curvature of a hypernetwork.Comment: to appear: Complex Networks '18 (oral presentation
Additional femoral catheter in combination with popliteal catheter for analgesia after major ankle surgery
Background The contribution of the saphenous nerve in pain after major ankle surgery is unknown. The aim of this study was to evaluate its contribution in this context. Methods Fifty patients were included in this prospective, randomized, controlled study. In all patients [Group P (popliteal) and Group F (popliteal+femoral)], a popliteal catheter was placed before operation and ropivacaine 0.5% (30 ml) administered via this catheter; major ankle surgery was then performed under spinal anaesthesia. In Group PF patients, an additional femoral catheter was sited before operation and ropivacaine 0.5% (10 ml) administered. Six hours after spinal anaesthesia (defined as T0), a continuous infusion of ropivacaine 0.3% (14 ml h−1) was started through the popliteal catheter until T24. Then, the concentration was reduced to 0.2% until T48. Patients in Group PF received continuous ropivacaine 0.2% (5 ml h−1) through the femoral catheter from T0 to T48. I.V. morphine patient-controlled analgesia was used as a rescue analgesia. Pain at rest, pain with movement, adverse effects, and i.v. morphine consumption were assessed. Pain at rest and on movement was evaluated 6 months after operation. Results Pain at rest was comparable in the two groups. In Group PF, patients had significantly reduced pain during movement in the postoperative period (P=0.01) and 6 months after operation (P=0.03). Morphine consumption was significantly reduced in Group PF at T0-T24 and T24-T48 (P=0.01). Adverse effects were comparable in both groups. Conclusions The addition of continuous femoral catheter infusion of ropivacaine to a continuous popliteal catheter infusion improved postoperative analgesia during movement after major ankle surgery. This effect was still present 6 months after surger
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