645 research outputs found
Forecasting Proximal Femur and Wrist Fracture Caused by a Fall to the Side during Space Exploration Missions to the Moon and Mars
The possibility of bone fracture in space is a concern due to the negative impact it could have on a mission. The Bone Fracture Risk Module (BFxRM) developed at the NASA Glenn Research Center is a statistical simulation that quantifies the probability of bone fracture at specific skeletal locations for particular activities or events during space exploration missions. This paper reports fracture probability predictions for the proximal femur and wrist resulting from a fall to the side during an extravehicular activity (EVA) on specific days of lunar and Martian exploration missions. The risk of fracture at the proximal femur on any given day of the mission is small and fairly constant, although it is slightly greater towards the end of the mission, due to a reduction in proximal femur bone mineral density (BMD). The risk of wrist fracture is greater than the risk of hip fracture and there is an increased risk on Mars since it has a higher gravitational environment than the moon. The BFxRM can be used to help manage the risk of bone fracture in space as an engineering tool that is used during mission operation and resource planning
A morphometric study of nucleolar organiser regions in cervical intraepithelial neoplasia
The study sought a correlation between the number of AgNOR granules and
the degree of cervical intraepithelial neoplasia (CIN). Thirty-five sections (5 normal,
10 CIN1, 10 CIN2 and 10 CIN3) were subjected to retrospective analysis.
The percentage of cells with 1, 2, 3, 4 and more AgNORs was calculated and the
number of granules per 100 cells was counted. The number of cells containing
single granules decreases. However, the number increases with CIN level when
the cells contain 4 and more AgNORs. The number of granules per 100 cells also
increases with the degree of CIN. It can be thus concluded that the number of cells
with 4 and more AgNOR granules can serve as a CIN differentiation exponent
The influence of doxycycline on articular cartilage in experimental osteoarthrosis induced by iodoacetate
The experiment was performed on 36 Wistar rats. On the first day of the experiment
iodoacetate was administered to the left posterior knee joint of the 18 rats
which composed Group I. The second group of 18 rats received additionally
doxycycline (doxy) through the gastric tube in doses comparable with those of
doxycycline used in humans. The experiment lasted 21 days. The animals were
sacrificed after 7, 14 and 21 days in groups of 6 rats each. In sections stained
with Safranin 0 semiquantitative histochemical intensity tests were performed
on articular cartilage glycosaminoglycans (GAG) using a four-point scale (0–3).
In the first group examined destructive lesions in the articular cartilage and weak
reactivity on GAG were noted at all stages of the experiment. The intensity of
GAG staining was higher in the second group after 14 and especially after 21 days,
which may suggest a protective action of doxy on articular cartilage
Non-compact Topological Branes on Conifold
We consider non-compact branes in topological string theories on a class of
Calabi-Yau spaces including the resolved conifold and its mirror. We compute
the amplitudes of the insertion of non-compact Lagrangian branes in the A-model
on the resolved conifold in the context of the topological vertex as well as
the melting crystal picture. They all agree with each other and also agree with
the results from Chern-Simons theory, supporting the large N duality. We find
that they obey the Schr\"odinger equation confirming the wavefunction behavior
of the amplitudes. We also compute the amplitudes of the non-compact B-branes
in the DV matrix model which arises as a B-model open string field theory on
the mirror manifold of the deformed conifold. We take the large N duality to
consider the B-model on the mirror of the resolved conifold and confirm the
wave function behavior of this amplitude. We find appropriate descriptions of
non-compact branes in each model, which give complete agreements among those
amplitudes and clarify the salient features including the role of symmetries
toward these agreements.Comment: 32 pages, 9 figures, a reference added, typos fixe
Hepatic profile analyses of tipranavir in Phase II and III clinical trials
<p>Abstract</p> <p>Background</p> <p>The risk and course of serum transaminase elevations (TEs) and clinical hepatic serious adverse event (SAE) development in ritonavir-boosted tipranavir (TPV/r) 500/200 mg BID recipients, who also received additional combination antiretroviral treatment agents in clinical trials (TPV/r-based cART), was determined.</p> <p>Methods</p> <p>Aggregated transaminase and hepatic SAE data through 96 weeks of TPV/r-based cART from five Phase IIb/III trials were analyzed. Patients were categorized by the presence or absence of underlying liver disease (+LD or -LD). Kaplan-Meier (K-M) probability estimates for time-to-first US National Institutes of Health, Division of AIDS (DAIDS) Grade 3/4 TE and clinical hepatic SAE were determined and clinical actions/outcomes evaluated. Risk factors for DAIDS Grade 3/4 TE were identified through multivariate Cox regression statistical modeling.</p> <p>Results</p> <p>Grade 3/4 TEs occurred in 144/1299 (11.1%) patients; 123/144 (85%) of these were asymptomatic; 84% of these patients only temporarily interrupted treatment or continued, with transaminase levels returning to Grade ≤ 2. At 96 weeks of study treatment, the incidence of Grade 3/4 TEs was higher among the +LD (16.8%) than among the -LD (10.1%) patients. K-M analysis revealed an incremental risk for developing DAIDS Grade 3/4 TEs; risk was greatest through 24 weeks (6.1%), and decreasing thereafter (>24-48 weeks: 3.4%, >48 weeks-72 weeks: 2.0%, >72-96 weeks: 2.2%), and higher in +LD than -LD patients at each 24-week interval. Treatment with TPV/r, co-infection with hepatitis B and/or C, DAIDS grade >1 TE and CD4<sup>+ </sup>> 200 cells/mm<sup>3 </sup>at baseline were found to be independent risk factors for development of DAIDS Grade 3/4 TE; the hazard ratios (HR) were 2.8, 2.0, 2.1 and 1.5, respectively. Four of the 144 (2.7%) patients with Grade 3/4 TEs developed hepatic SAEs; overall, 14/1299 (1.1%) patients had hepatic SAEs including six with hepatic failure (0.5%). The K-M risk of developing hepatic SAEs through 96 weeks was 1.4%; highest risk was observed during the first 24 weeks and decreased thereafter; the risk was similar between +LD and -LD patients for the first 24 weeks (0.6% and 0.5%, respectively) and was higher for +LD patients, thereafter.</p> <p>Conclusion</p> <p>Through 96 weeks of TPV/r-based cART, DAIDS Grade 3/4 TEs and hepatic SAEs occurred in approximately 11% and 1% of TPV/r patients, respectively; most (84%) had no significant clinical implications and were managed without permanent treatment discontinuation. Among the 14 patients with hepatic SAE, 6 experienced hepatic failure (0.5%); these patients had profound immunosuppression and the rate appears higher among hepatitis co-infected patients. The overall probability of experiencing a hepatic SAE in this patient cohort was 1.4% through 96 weeks of treatment. Independent risk factors for DAIDS Grade 3/4 TEs include TPV/r treatment, co-infection with hepatitis B and/or C, DAIDS grade >1 TE and CD4<sup>+ </sup>> 200 cells/mm<sup>3 </sup>at baseline.</p> <p>Trial registration</p> <p>US-NIH Trial registration number: NCT00144170</p
Dideoxynucleoside HIV reverse transcriptase inhibitors and drug-related hepatotoxicity: a case report
This report regards the case of a 43 year-old HIV-positive woman who developed an episode of serious transaminase elevation during stavudine-including antiretroviral therapy. Diagnostic assessment ruled out hepatitis virus co-infection, alcohol abuse besides other possible causes of liver damage. No signs of lactic acidosis were present. Liver biopsy showed portal inflammatory infiltrate, spotty necrosis, vacuoles of macro- and micro-vesicular steatosis, acidophil and foamy hepatocytes degeneration with organelles clumping, poorly formed Mallory bodies and neutrophil granulocytes attraction (satellitosis). A dramatic improvement in liver function tests occurred when stavudine was discontinued and a new antiretroviral regimen with different nucleoside reverse transcriptase inhibitors was used. The importance of considering hepatotoxicity as an adverse event of HAART including stavudine, even in absence of other signs of mitochondrial toxicity should therefore be underlined. Liver biopsy may provide further important information regarding patients with severe transaminase elevation, for a better understanding of the etiology of liver damage
Penner Type Matrix Model and Seiberg-Witten Theory
We discuss the Penner type matrix model recently proposed by Dijkgraaf and
Vafa for a possible explanation of the relation between four-dimensional gauge
theory and Liouville theory by making use of the connection of the matrix model
to two-dimensional CFT. We first consider the relation of gauge couplings
defined in UV and IR regimes of N_f = 4, N = 2 supersymmetric gauge theory
being related as . We then use this relation to discuss the action of modular
transformation on the matrix model and determine its spectral curve.
We also discuss the decoupling of massive flavors from the N_f = 4 matrix
model and derive matrix models describing asymptotically free N = 2 gauge
theories. We find that the Penner type matrix theory reproduces correctly the
standard results of N = 2 supersymmetric gauge theories.Comment: 22 pages; v2: references added, typos corrected; v3: a version to
appear in JHE
Rationale, challenges, and participants in a Phase II trial of a botanical product for chronic hepatitis C
Background Chronic hepatitis C is associated with significant morbidity and mortality as a consequence of progression to cirrhosis, hepatocellular carcinoma, and liver failure. Current treatment for chronic hepatitis C with pegylated interferon (IFN) and ribavirin is associated with suboptimal responses and numerous adverse effects. A number of botanical products have been used to treat hepatic disorders. Silymarin, extracted from the milk thistle plant, Silybum marianum (L) Gaertn. (Asteraceae), has been most widely used for various liver disorders, including chronic hepatitis C, B, and alcoholic liver disease. However, the safety and efficacy of silymarin have not been studied systematically in chronic hepatitis C
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