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排序方式: 共有1871条查询结果,搜索用时 15 毫秒
991.
Sleep state changes in response to different thermal stimuli were investigated in newborn piglets between 2 and 10 days of age. Test animals were exposed to cold air (7-12 degrees C) and warm air (27-33 degrees C) around the face, while the remainder of the body was kept at first warm (normothermic) then hyperthermic. A separate group of animals was studied under normothermic conditions (control) for the duration of the study. Piglets showed typical changes in sleep state patterns characteristic of rapid maturation over the first 10 days of development. It was found that both the amount of rapid eye movement (REM) sleep and, in some cases, the duration of REM episodes increased in response to facial cooling regardless of rectal temperature. However, hyperthermia with warm air exposure caused a significant decrease in the amount of REM sleep but not in the duration of REM episodes. It is suggested that an infant placed to bed in a cold room or exposed to a draft might also experience a greater amount of REM sleep than an infant placed to sleep in a warm draft-free room. 相似文献
992.
Cholesterol granuloma of the breast is a rare benign condition. It is often clinically and radiologically indistinguishable from breast carcinoma. A case of cholesterol granuloma which manifested as an intracystic papilloma on ultrasound is described. This unusual ultrasonographic appearance has not previously been reported. 相似文献
993.
OBJECTIVE: Patients with rheumatoid arthritis (RA) have reduced life expectancy; however, there are few data on the changing pattern of causes of death with longterm followup, or on the longterm effect of early presentation. The objectives of this study were (1) to examine the effect of early presentation on subsequent mortality; (2) to compare the causes of death early and late in the followup period; and (3) to compare survival of the cohort with that of the general population (adjusted for age and sex) over a followup period of up to 27 years. METHODS: A cohort of 448 patients with RA (inpatients and outpatients), assembled 1968-74, were followed to December 31, 1990. Death certificates were obtained for all who had died and coded using the International Classification of Diseases. Kaplan-Meier survival curves were constructed. RESULTS: By the end of the study, 266 patients (59%) had died. The standardized mortality ratio (SMR) was 2.7 (95% CI 2.4-3.1). Patients who presented early continued to do well. Most excess deaths were due to cardiovascular disease. SMR due to infection, renal failure, and non-Hodgkin's lymphoma rose with disease duration. CONCLUSION: Patients with RA should be referred early, and those with chronic disease should be closely monitored for evidence of infection and renal impairment. 相似文献
994.
Z Wroblewska T Valyi-Nagy J Otte A Dillner A Jackson DP Sole NW Fraser 《Canadian Metallurgical Quarterly》1993,15(2):141-151
Following primary infection with varicella-zoster virus (VZV), the virus establishes a latent infection in humans. The molecular pathogenesis of VZV latency is not well understood, mainly due to the lack of an adequate animal model. We report here that we have developed a mouse model for VZV infection that involves corneal inoculation of mice. Although infected animals showed no signs of disease, most of the animals could not eliminate the virus early after infection. By PCR, we demonstrated that at 33 days post-infection (p.i.), viral DNA was still present in more than 60% of the animals (14/21). VZV DNA was most frequently detected in the trigeminal ganglia (7/14) followed by the brain stem (10/21), kidneys (4/21), spleen (3/20), liver (2/21) and brain (1/21). By in situ hybridization, a few cells positive for VZV mRNA were detected in the trigeminal ganglia, brain stem, cerebellum and spleen of a small number of the infected animals as late as 33 days p.i. No viral proteins were detected at the site of inoculation or in any other tissue by immunostaining. Our results suggest that VZV spreads in mice by both viraemia and axonal transport and establishes a non-productive (latent) infection. 相似文献
995.
H Kozáková R St?pánková J Kolínská MA Farré DP Funda L Tucková H Tlaskalová-Hogenová 《Canadian Metallurgical Quarterly》1998,43(5):497-500
BACKGROUND: Gastric outlet obstruction is commonly considered a complication of peptic ulcer disease. Malignancy accounts for up to 39% of gastric outlet obstruction. The object of this study was to evaluate the reliability of endoscopic biopsies in excluding malignancy as the cause of gastric outlet obstruction. METHODS: A retrospective study of 40 consecutive patients admitted with gastric outlet obstruction was conducted. Patient demographics, their use of H2-receptor antagonists or nonsteroidal anti-inflammatory drugs, and history of peptic ulcer disease were recorded. Histopathologic results of the endoscopic biopsy and surgical specimen were reviewed. The diagnosis based on the surgical specimen was considered the gold standard. RESULTS: Sixteen patients (40%) had malignant gastric outlet obstruction. Seven patients had gastric adenocarcinoma and nine had extragastric tumors. The patients with malignant obstruction were significantly older (> 55 years) (p = 0.03; odds ratio: 95% CI: 5.21 [1.05-23.49]). Gastric cancer patients had less frequently a history of peptic ulcer disease when compared with patients with benign gastric outlet obstruction (p = 0.04; odds ratio: 95% CI: 5 [1.04-38.13]). Endoscopic biopsy to detect malignant obstruction had poor sensitivity (i.e., 37%) when compared with biopsies of the surgical specimen. In three of seven patients with gastric cancer (40%), repeated jumbo biopsies were negative for malignancy. CONCLUSION: Patients with gastric outlet obstruction who had endoscopic biopsies negative for cancer should be explored surgically before embarking on medical therapy. The surgical exploration is especially important in gastric outlet obstruction patients who are considered at high risk for malignancy, that is, those who are older and have no history of peptic ulcer disease. 相似文献
996.
J Schrenzel L Serrander B Bánfi O Nüsse R Fouyouzi DP Lew N Demaurex KH Krause 《Canadian Metallurgical Quarterly》1998,392(6677):734-737
Electron transport across biological membranes is a well-known feature of bacteria, mitochondria and chloroplasts, where it provides motive forces for vectorial transport processes. In contrast, electron transport is generally not found in the plasma membrane of eukaryotic cells, possibly because it would interfere with electric processes at the plasma membrane. An exception is provided by the phagocyte NADPH oxidase, which generates superoxide (O2.-) through electron transfer from cytosolic NADPH to extracellular oxygen. The enzyme is essential for host defence, and patients with chronic granulomatous disease, who lack the functional enzyme, suffer from severe infections. It has been suggested that electron transfer by the NADPH oxidase might be electrogenic. Here we demonstrate, using the whole-cell patch-clamp technique, the generation of electron currents by the NADPH oxidase in human eosinophil granulocytes. The currents were absent in granulocytes of sufferers of chronic granulomatous disease and under conditions of low oxygen. Generation of electron currents across the plasma membrane of eukaryotic cells has not been observed previously and might be-independently of the generation of superoxide-a physiologically relevant function of the phagocyte NADPH oxidase. 相似文献
997.
The purpose of this clinical study was to determine the efficacy, tolerability, and impact on quality of life of domperidone--a specific peripherally acting dopamine antagonist--in the management of symptoms of gastroparesis, a common and potentially debilitating condition in patients with diabetes mellitus. In the first phase of this multicenter, two-phase withdrawal study, 287 diabetic patients with symptoms of gastroparesis of at least 6 months' duration received domperidone 20 mg QID in a single-masked fashion for 4 weeks. Efficacy was evaluated using a four-point rating scale (0 = none, 1 = mild, 2 = moderate, 3 = severe) for each of the following symptoms: nausea, abdominal distention/bloating, early satiety, vomiting, and abdominal pain. At the end of the first phase, patients with sufficient improvement in their total symptom score (a score < or = 6 and a decrease in score of > or = 5 units from the baseline [selection] visit) were eligible for the 4-week, randomized, placebo-controlled, double-masked withdrawal phase of the study. The impact of domperidone on quality of life was determined using the Medical Outcomes Study Short Form-36 (SF-36). Of 269 patients with data from the single-masked phase, 208 (77%) qualified for entry into the double-masked phase based on a statistically significant improvement in total symptom score, from a mean score of 10.32 at baseline (initial visit) to 3.79 after 4 weeks of single-masked domperidone therapy. During the double-masked phase, patients in the placebo group had significantly greater deterioration in total symptom scores compared with patients in the domperidone group (mean changes of 1.84 and 0.85, respectively). Similar significant differences in favor of domperidone were seen in the secondary efficacy variables (i.e., patients' diary scores and global assessments of symptoms). The tolerability profile of domperidone was similar to that of placebo. Patients who responded to domperidone experienced significant improvements in quality of life, as indicated by the SF-36 physical and mental component summary scores. During the double-masked phase, patients who were randomized to placebo experienced a significant deterioration in the physical component summary score compared with patients in the domperidone group. The results of this study suggest that domperidone 20 mg QID provides significant improvement in the upper gastrointestinal symptoms of diabetic gastroparesis and is well tolerated in patients with this condition. 相似文献
998.
EJ Farrell RJ Gorniak EL Kramer ME Noz GQ Maguire DP Reddy 《Canadian Metallurgical Quarterly》1997,21(3):155-172
We present a graphical three-dimensional method that facilitates image registration and fusion, and provides quantitative geometric and volume information. In particular it enhances the use of functional (radiopharmaceutical) imaging (SPECT, PET) which, though a powerful clinical tool, has the disadvantage of low spatial resolution and ill-defined boundaries. Registration between functional images and structural images (MRI, CT) can augment the anatomical context of these functional images. 相似文献
999.
Development of a novel adaptive lead-free solder containing reinforcements displaying the shape-memory effect 总被引:3,自引:0,他引:3
I. Dutta B. S. Majumdar D. Pan W. S. Horton W. Wright Z. X. Wang 《Journal of Electronic Materials》2004,33(4):258-270
Microelectronic solder joints are typically exposed to aggressive thermomechanical cycling (TMC) conditions during service.
During TMC, strain localization occurs near solder/bond pad interfaces, where large, inelastic-shear strains accumulate, eventually
causing low-cycle fatigue (LCF) failure of the joint. In this study, a novel methodology to mitigate the effects of strain
localization within the joint is discussed, wherein the solder alloy is reinforced with a martensitic NiTi-based, shape-memory
alloy (SMA). In this scheme, the SMA reinforcement deforms in shear concurrently with the solder during TMC and, subsequently,
undergoes martensite-to-austenite (M → A) transformation, placing the solder matrix next to the reinforcements in reverse
shear. This is purported to reduce inelastic-strain localization within the solder and, thus, enhance joint life. In this
paper, we present results of thermal-mechanical loading experiments conducted on a monolithic 95.5Sn-3.8Ag-0.7Cu solder, a
Cu/Cu6Sn5 particle-reinforced solder, and NiTi-solder, single-fiber composites (SFCs) to elucidate the impact of the shape-memory effect
on the overall joint behavior. It is demonstrated that during TMC, the phase transformations occurring in NiTi can significantly
reduce the inelastic-strain range to which a joint is subjected (by ∼25% in the present experiments). Finally, we report on
the successful fabrication of a composite solder paste from which adaptive solders with a uniform distribution of about 5
vol.% of NiTi particulates may be produced. 相似文献
1000.
Postoperative pain is a common reason for the delayed discharge and unanticipated hospital admission of out-patients. In this study, we examined the pattern of pain in ambulatory surgical patients and determined those factors that predict postoperative pain. Ten thousand eight consecutive ambulatory surgical patients were prospectively studied. Preoperative patient characteristics, intraoperative variables, and pain in the postanesthesia care unit (PACU) and the ambulatory surgical unit (ASU) and 24 h postoperatively were documented. The incidence of severe pain was 5.3% in the PACU, 1.7% in the ASU, and 5.3% 24 h postoperatively. In the PACU, younger male adults (36 +/- 13 vs 47 +/- 22 yr), ASA physical status I patients, and patients with a higher body mass index (26 +/- 5 vs 25 +/- 5 kg) had a higher incidence of severe pain. In the group with severe pain, the duration of anesthesia, the duration of stay in the PACU and the ASU, and the time to discharge was longer than in the group without severe pain. In the PACU, orthopedic patients had the highest incidence of pain (16.1%), followed by urologic (13.4%), general surgery (11.5%), and plastic surgery (10.0%) patients. In patients who had general anesthesia, the intraoperative dose of fentanyl was significantly smaller in the group with severe pain than in the group without severe pain when body mass index and duration of anesthesia were taken into consideration. Body mass index, duration of anesthesia, and certain types of surgery were significant predictors of severe pain in the PACU. This knowledge will allow us to identify those patients at risk of severe postoperative pain and manage them prophylactically. Implications: The pattern of pain was examined in 10,008 consecutive ambulatory surgical patients. The incidence of severe pain was 5.3% in the postanesthesia care unit, 1.7% in the ambulatory surgical unit, and 5.3% 24 h postoperatively. Body mass, duration of anesthesia, and certain types of surgery were significant predictors of pain in the postanesthesia care unit. These data will allow us to better predict those patients who need intense prophylactic analgesic therapy. 相似文献