1,169 research outputs found
Three dimensional thermal analysis of rocket thrust chambers
A numerical model for the three dimensional thermal analysis of rocket thrust chambers and nozzles has been developed. The input to the model consists of the composition of the fuel/oxidant mixture and flow rates, chamber pressure, coolant entrance temperature and pressure, dimensions of the engine, materials and the number of nodes in different parts of the engine. The model allows for temperature variation in three dimensions: axial, radial and circumferential directions and by implementing an iterative scheme, it provides nodal temperature distribution, rates of heat transfer, hot gas and coolant thermal and transport properties
Long-term follow-up of residual masses after chemotherapy in patients with non-seminomatous germ cell tumours
This retrospective study was undertaken to determine the outcome of patients with non-seminomatous germ cell tumour who achieved a serological complete response but who had residual radiologic abnormalities upon completion of primary platinum-based chemotherapy. This was an analysis of 76 consecutive patients treated at Mount Vernon Hospital between 1983 and 1997. The patients were placed into two groups based upon whether they had surgical resection (surgery group, 48 patients) or observation (observation group, 28 patients) of residual radiologic masses on completion of initial chemotherapy (to enter the surgery group, complete surgical resection must have been achieved). The primary end-points were progression-free and overall survival. The percentage of patients alive with median follow-up 66 months was 90% for the surgery group and 80% for the observation group (P= 0.53, not significant). The percentage of patients continuously disease-free was 70% in the surgery group and 80% in the observation group (P= 0.31, not significant). In the small sub-group of patients with differentiated teratoma (TD) in the primary lesion who were observed, there was no excess risk of relapse or death. Patients who achieve a serological complete response after primary chemotherapy, but are left with †2âcm radiological masses that are not cystic and have responded, can be safely observed with diligent follow-up. © 2000 Cancer ResearchCampaig
Diagnosis and neurosurgical treatment of glossopharyngeal neuralgia: clinical findings and 3-D visualization of neurovascular compression in 19 consecutive patients
Glossopharyngeal neuralgia is a rare condition with neuralgic sharp pain in the pharyngeal and auricular region. Classical glossopharyngeal neuralgia is caused by neurovascular compression at the root entry zone of the nerve. Regarding the rare occurrence of glossopharyngeal neuralgia, we report clinical data and magnetic resonance imaging (MRI) findings in a case series of 19 patients, of whom 18 underwent surgery. Two patients additionally suffered from trigeminal neuralgia and three from additional symptomatic vagal nerve compression. In all patients, ipsilateral neurovascular compression syndrome of the IX cranial nerve could be shown by high-resolution MRI and image processing, which was confirmed intraoperatively. Additional neurovascular compression of the V cranial nerve was shown in patients suffering from trigeminal neuralgia. Vagal nerve neurovascular compression could be seen in all patients during surgery. Sixteen patients were completely pain free after surgery without need of anticonvulsant treatment. As a consequence of the operation, two patients suffered from transient cerebrospinal fluid hypersecretion as a reaction to Teflon implants. One patient suffered postoperatively from deep vein thrombosis and pulmonary embolism. Six patients showed transient cranial nerve dysfunctions (difficulties in swallowing, vocal cord paresis), but all recovered within 1Â week. One patient complained of a gnawing and burning pain in the cervical area. Microvascular decompression is a second-line treatment after failure of standard medical treatment with high success in glossopharyngeal neuralgia. High-resolution MRI and 3D visualization of the brainstem and accompanying vessels as well as the cranial nerves is helpful in identifying neurovascular compression before microvascular decompression procedure
The effects of swimming exercise and supraphysiological doses of nandrolone decanoate on the testis in adult male rats: a transmission electron microscope study
Anabolic-androgenic steroids (AAS) are used in high doses by athletes to improve
athletic ability, physical appearance, and muscle mass. Unfortunately,
the abuse of these agents has significantly increased. It has been established
that exercise and high doses of AAS may influence the hypothalamic-pituitary
gonadal (H-P-G) axis, which can in turn affect the ultrastructure of the testes.
However, the effect of the combination of exercise and high doses of AAS on
the ultrastructure of the testes is not known. This study was undertaken in
order to examine the combination effects of swimming exercise and supraphysiological
doses of nandrolone decanoate on the ultrastructural changes in
rat testes. Five groups of male Wistar strain albino rats were treated as follows
for 8 weeks: solvent of nandrolone decanoate (peanut oil) as a vehicle (sham);
nandrolone decanoate (ND) (10 mg/kg/week) - ND; exercise (1 h/day, 5 days
a week) - exercise; ND (10 mg/kg/week) and exercise (1 h/day, 5 days a week)
- ND-EX; and sedentary control without any injection or exercise - control.
Ultrastructural changes in the rat testes were characterised by transmission
electron microscopy. The number and size of Leydig cells were considerably
decreased in the interstitial space in the experimental rats. The increased thickness
and irregular wavy multilaminar appearance of basement membrane in
the treated animals, especially in the ND-EX group, are associated with well
developed myoid cells. Cytoplasm vacuolisation, vesicular-like crista of the mitochondria,
numerous lipid droplets, and lysosome and phagolysosome in Sertoli
cells were significantly observed in the experimental groups. Several apoptotic
germ cells were considerably observed in the experimental rats (p ≤ 0.05).
Exercise training seems to increase the extent of ultrastructural changes caused
by supraphysiological doses of ND in rats, which in turn may affect fertility.
(Folia Morphol 2010; 69, 3: 138-146
Pragmatic randomised controlled trial of very early etanercept and MTX versus MTX with delayed etanercept in RA: the VEDERA trial
Objectives: We sought to confirm in very early rheumatoid arthritis (ERA) a much greater superiority (30%) of first-line etanercept+methotrexate (ETN+MTX) over treat-to-target MTX (MTX-TT) than previously reported in ERA (14%); and explore whether ETN following initial MTX secures a comparable response to first-line ETN+MTX.
Methods: Pragmatic, open-label, randomised controlled trial of treatment-naĂŻve ERA (â€12âmonths symptom), Disease Activity Score 28 joint (DAS28)-erythrocyte sedimentation rate (ESR) â„3.2, rheumatoid factor (RF)+/âanticitrullinated peptide antibody (ACPA) positive or ultrasound power Doppler (PD) if RF and ACPA negative. Subjects were randomised 1:1 to ETN+MTX; or MTX-TT, escalated to ETN if week 24 DAS28-ESR â„2.6 and intramuscular corticosteroid at protocolised time points. Primary endpoint of week 48 DAS28ESR remission with clinical and imaging secondary endpoints.
Results: We randomised 120 patients, 60 to each arm (71% female, 73% RF/84% ACPA positive, median (IQR) symptom duration 20.3 (13.1, 30.8) weeks; mean (SD) DAS28 5.1 (1.1)). Remission rates with ETN+MTXâand MTX-TT, respectively, were 38% vs 33% at week 24; 52% vs 38% at week 48 (ORs 1.6, 95%âCI 0.8 to 3.5, p=0.211). Greater, sustained DAS28-ESR remission observed with ETN+MTXâversus MTX-TT (42% and 27%, respectively; p=0.035). PD was fully suppressed by week 48 in over 90% in each arm. Planned exploratory analysis revealed OR 2.84, 95%âCI 0.8 to 9.6) of achieving remission after 24 weeks of ETN administered first line compared with administered post-MTX.
Conclusions: Compared with remission rates typically reported with first-line tumour necrosis factor inhabitor+MTX versus MTX-TT, we did not demonstrate a larger effect in very ERA. Neither strategy conferred remission in the majority of patients although ultrasound confirmed local inflammation suppression. Poorer ETN response following failure of MTX-TT is also suggested.
Trial registration number:
NCT0243318
Pimecrolimus 1 percent cream and pulsed dye laser in treatment of a patient with reticular erythematous mucinosis syndrome
We report on the efficacy of twice daily application of pimecrolimus 1 percent cream in a 48-year-old woman with reticular erythematous mucinosis (REM) syndrome and compare its results with pulsed dye laser (PDL) on the other side of her chest and back. The patient was previously treated by hydroxychloroquine but only a fair response was observed. After application of 5 months of pimecrolimus, the lesions completely resolved and the result was comparable with the other side of her body treated by pulsed dye laser PDL. Topical pimecrolimus and pulsed dye laser appear to be effective and safe treatments for REM. Ă© 2007 Dermatology Online Journal
Conformational changes of calmodulin upon Ca2+ binding studied with a microfluidic mixer
A microfluidic mixer is applied to study the kinetics of calmodulin conformational changes upon Ca2+ binding. The device facilitates rapid, uniform mixing by decoupling hydrodynamic focusing from diffusive mixing and accesses time scales of tens of microseconds. The mixer is used in conjunction with multiphoton microscopy to examine the fast Ca2+-induced transitions of acrylodan-labeled calmodulin. We find that the kinetic rates of the conformational changes in two homologous globular domains differ by more than an order of magnitude. The characteristic time constants are â490 ÎŒs for the transitions in the C-terminal domain and â20 ms for those in the N-terminal domain of the protein. We discuss possible mechanisms for the two distinct events and the biological role of the stable intermediate, half-saturated calmodulin
Report of the GDR working group on the R-parity violation
This report summarizes the work of the "R-parity violation group" of the
French Research Network (GDR) in Supersymmetry, concerning the physics of
supersymmetric models without conservation of R-parity at HERA, LEP, Tevatron
and LHC and limits on R-parity violating couplings from various processes. The
report includes a discussion of the recent searches at the HERA experiment,
prospects for new experiments, a review of the existing limits, and also
theoretically motivated alternatives to R-parity and a brief discussion on the
implications of R-parity violation on the neutrino masses.Comment: 60 pages, LaTeX, 22 figures, 2 table
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