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Piotr Zoltowski Bartlomiej Legawiec 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》2004,572(2):205-210
Transport of hydrogen in elastic metals has been analysed in terms of an impedance-like non-linear transfer function (TF). The equilibrium in a membrane specimen is perturbed by a sinusoidal signal of the concentration of hydrogen, of large amplitude, applied to one of its surfaces. The fundamental harmonics of periodically reproducible flux at the same surface is considered as a response. The TF is defined as the ratio of the signal to the response. The power of the said TF in determining the diffusion coefficient of hydrogen in a metal–hydrogen system and its bulk elastic modulus was analysed for the example of α-phase Pd–H and Pd81Pt19–H systems. It has been found that such a TF is suitable for determination of the above parameters. Also, the sensitivity of these estimates to the uncertainty of concentration of hydrogen in the metal, its partial molar volume and the thickness of the specimen has been explored. 相似文献
14.
Piotr Kozlowski Alastair M. Buchan Ursula I. Tuor Dong Xue Zhi-Gao Huang Karen E. Chaundy John K. Saunders 《Magnetic resonance in medicine》1997,37(3):346-354
31P, 1H and lactate spectroscopic imaging was used to evaluate the effects of hypothermia on focal cerebral ischemia produced by middle cerebral artery occlusion. The effects on high energy phosphate metabolism, pH, lactate and NAA were investigated in 24 spontaneously hypertensive rats subjected to either permanent or transient ischemia. Under either normothermic (37.5°C) or hypothermic (32°C) conditions, with permanent 6-h occlusion, there was little difference between groups in either the NMR measurements or the volume of infarction. In animals that underwent 3 h of ischemia followed by 12 h of reperfusion, the ischemic changes in lactate, pH, NAA, and high-energy phosphate returned toward control values, and there was a protective effect of hypothermia (infarct volume of 211 ± 26 and 40 ± 14 mm3 in normothermic and hypothermic groups, respectively). Thus, hypothermia did not ameliorate the changes in lactate, pH, NAA, or high energy phosphate levels occurring during ischemia, however, during reperfusion there was an improvement in both the recovery of these metabolites and pathological outcome in hypothermic compared with normothermic animals. 相似文献
15.
Micha? Ciurzyński Piotr Bienias Agnieszka Szewczyk Barbara Lichodziejewska Maria B?aszczyk Danuta Liszewska-Pfejfer Piotr Pruszczyk 《Medical science monitor》2007,13(10):CS124-CS127
BACKGROUND: Systemic sclerosis (SSc) is a connective tissue disorder of unknown etiology characterized by fibrosis of the skin and visceral organs, in which the heart is frequently (40-70% of patients) and severely involved. Pulmonary hypertension affects 10-15% of patients with SSc and is one of the most important complications adversely influencing their survival. CASE REPORT: The case report presents a 59-year-old male patient with advanced systemic sclerosis whose initial examination revealed pulmonary hypertension, rhythm and atrioventricular conduction disturbances, and elevated level of NT-proBNP. After six months the patient deteriorated; an increase in NT-proBNP level and progression of pulmonary hypertension were observed. CONCLUSIONS: The described case is followed by a discussion of cardiovascular involvement in systemic sclerosis and emphasizes that heart involvement in SSc may have very serious clinical implications. 相似文献
16.
Piotr K?osiński Maciej Gilis-Januszewski Witold Serafin 《Chirurgia narzadów ruchu i ortopedia polska》2004,69(3):167-172
Early results (12 weeks after surgery) of the lumbar spinal stenosis operative treatment were assessed in the group of 36 patients (aged 40-65 years). In 72% of patients posterior fusion was applied. In the results evaluation lumbar pain, low extremities pain, neurogenic claudicat ion, sensory disturbances and functional status were taken in account. A significant decrease in low extremities and lumbar pain was observed. Some sensory disturbances after operative treatment did not affect general high patients assessment of the performed surgical procedures (positive 80.5% cases). 相似文献
17.
Anna Gasinska Jan Skolyszewski Tadeusz Popiela Piotr Richter Zbigniew Darasz Krystyna Nowak Joanna Niemiec Beata Biesaga Agnieszka Adamczyk Krzysztof Bucki Krzysztof Malecki Marian Reinfuss Teresa Kowalska 《Journal of gastrointestinal surgery》2007,11(4):520-528
Purpose Assessment of tumor proliferation rate using Bromodeoxyuridine labeling index (BrdUrdLI) as a possible predictor of rectal
cancer response to preoperative radiotherapy (RT).
Methods and material Ninety-two patients were qualified either to short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I),
or to short RT and 4–5 weeks interval before surgery (schedule II). Tumor samples were taken twice from each patient: before
RT and at the time of surgery. The samples were incubated with BrdUrd for 1 h at 37°C, and the BrdUrdLI was calculated as
a percentage of BrdUrd-labeled cells.
Results Thirty-eight patients were treated according to schedule I and 54 patients according to schedule II. Mean BrdUrdLI before
RT was 8.5% and its value did not differ between the patients in the two compared groups. After RT tumors showed statistically
significant growth inhibition (reduction of BrdUrdLI). As the pretreatment BrdUrd LI was not predictive for early clinical
and pathologic tumor response, prognostic role of the ratio of BrdUrdLI after to BrdUrdLI before RT was considered. The ratios
were calculated separately for fast (BrdUrd LI > 8.5%) and slowly (BrdUrd LI ≤ 8.5%) proliferating tumors and correlated with
overall treatment time (OTT, i.e., time from the first day of RT to surgery). One month after RT, accelerated proliferation
was observed only in slowly proliferating tumors.
Conclusions Pretreatment BrdUrdLI was not predictive for early clinical and pathologic tumor response. The ratio after/before RT BrdUrdLI
was correlated to inhibition of proliferation in responsive tumors.
The paper was presented at ECCO 13, October 30 to November 03, 2005 in Paris, France 相似文献
18.
Guido Germano Paul B. Kavanagh Piotr J. Slomka Serge D. Van Kriekinge Geoff Pollard Daniel S. Berman 《Journal of nuclear cardiology》2007,14(4):433-454
Cedars-Sinai’s approach to the automation of gated perfusion single photon emission computed tomography (SPECT) imaging is
based on the identification of key procedural steps (processing, quantitation, reporting), each of which is then implemented,
in completely automated fashion, by use of mathematic algorithms and logical rules combined into expert systems. Our current
suite of software applications has been designed to be platform- and operating system-independent, and every algorithm is
based on the same 3-dimensional sampling scheme for the myocardium. The widespread acceptance of quantitative software by
the nuclear cardiology community (QGS alone is used at over 20,000 locations) has provided the opportunity for extensive validation
of quantitative measurements of myocardial perfusion and function, in our opinion, helping to make nuclear cardiology the
most accurate and reproducible modality available for the assessment of the human heart. 相似文献
19.
Andrzej Zyluk Ireneusz Walaszek Piotr Puchalski 《Chirurgia narzadów ruchu i ortopedia polska》2004,69(5):297-300
A series of 54 patients is presented in which full-thickness soft-tissue defects on 57 digits were reconstructed using homodigital V-Y flaps. This is a modification of the Moberg procedure, which was designed for coverage of injuries of distal thumb. The V-Y flap is pedicled on two digital neurovascular bundles, possible advancement is up to 2 cm, and V-shaped base of the flap allows direct closure of the proximal defect, without skin grafting. This technique was used for the reconstruction both volar and dorsal tissue defects of the fingers. All flaps healed within 2-4 weeks. 14 patients (15 fingers) were evaluated after they recovered. In all affected fingers active range of motion was satisfactory, only with slight defect of extension in 2 cases. However, sensation of the light touch was decreased in 10 fingers, and 2PD discrimination was abnormal in 5 fingers. The versatility of V-Y technique in various clinical occasions and its low risk of complications was emphasized. This method is very useful, easy to learn even for trainees unfamiliar with microsurgery. 相似文献
20.
Brian K Owler Shahan Momjian Zofia Czosnyka Marek Czosnyka Alonso Péna Neil G Harris Piotr Smielewski Tim Fryer Tim Donovan Jonathon Coles Adrian Carpenter John D Pickard 《Journal of cerebral blood flow and metabolism》2004,24(1):17-23
Regional cerebral blood flow (CBF) was studied with O(15)-water positron emission tomography and anatomic region-of-interest analysis on co-registered magnetic resonance in patients with idiopathic (n = 12) and secondary (n = 5) normal pressure hydrocephalus (NPH). Mean CBF was compared with values obtained from healthy volunteers (n = 12) and with clinical parameters. Mean CBF was significantly decreased in the cerebrum and cerebellum of patients with NPH. The regional analysis demonstrated that CBF was reduced in the basal ganglia and the thalamus but not in white matter regions. The results suggest that the role of the basal ganglia and thalamus in NPH may be more prominent than currently appreciated. The implications for theories regarding the pathogenesis of NPH are discussed. 相似文献