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21.
In addition to the difficulties related to the definition of a reference population and hence of reference limits, special methodological problems have to be dealt with when early markers of renal damage are applied to monitor groups at risk. The urinary excretion of both high and low molecular weight proteins, as measured by sensitive immunoassays, is routinely applied in health surveillance programmes aimed at preventing the occurrence of adverse renal effects resulting from exposure to nephrotoxic chemicals, among which are several metals. Owing to the large intra-individual variability experimentally demonstrated for all indicators of renal impairment, carefully standardized sampling conditions must be adopted. At the individual level, repeated measurements should be performed before a diagnosis of renal disease or dysfunction is established. In fact, several physiological conditions may account for transient changes in renal function, leading to measured levels greatly exceeding reference limits.  相似文献   
22.

Information

V International Conference and Exhibition “Computer-Aided Design and Manunfacture Product Data Manager (CAD/CAM/PDM-2005)” October 25–27, 2005  相似文献   
23.
The objective of this study was to analyse the immune response to electromagnetic fields (ELMFs) in seven men and eight women employed in a museum. The workers were exposed in a room to an ELMFs (range 0.2-3.6 microT and 40-120 V/m) induced by 50 Hz electricity for 20 h a week. Control groups consisted of 47 women and 39 men with a similar percentage of atopic subjects, age (range 30-51 years) and smoking habits of the workers included in the study. Levels of blood lead (Pb) and urinary trans-trans muconic acid, a metabolite of benzene (markers of exposure to traffic and smoking) of the control and exposed groups were similar. Lymphocyte subsets were determined in men and women using conjugated antibodies. Serum interleukin (IL) 4 and interferon gamma and their 'in vitro' production by peripheral mononuclear blood cells (PMBCs) stimulated by phytohemoglutinin (PHA), as well as blastogenesis of PMBCs induced by PHA, were determined in women only. ELMF-exposed women showed a significant reduction in the percentage of B and NK CD3(-)-CD25+ lymphocytes and a slight reduction of CD16(+)-56+ NK lymphocytes. They also showed significantly lower levels of interferon gamma in serum, or produced in the supernatants by PMBCs both spontaneously and stimulated by PHA, while they did not show significant changes in serum and 'in vitro' produced IL-4, or in blastogenesis of PMBCs. Men working in the museum showed, in relation to the controls, a statistically significant reduction in both number and percentage of CD16(+)- CD56+ and CD3(-)-CD25+ lymphocyte subsets. On the whole, this investigation demonstrates a reduction of blood NK lymphocytes and of the production of interferon gamma in workers exposed to low frequency ELMFs. Recent studies have shown that stress and poor lifestyle induce the reduction of blood cytotoxic activities possibly acting on nervous functions. This may suggest that ELMFs reduces blood NK lymphocytes by combined effects on the immune and nervous systems.  相似文献   
24.
An MS patient experienced sudden hearing loss. Brainstem auditory evoked potentials, previously normal, showed substantial abnormalities that suggested the impairment of the distal part of the acoustic nerve. MRI detected a small hyperintense lesion along the acoustic nerve; the lesion decreased in size and then disappeared after steroid treatment. This demonstrates that a demyelinating lesion in the distal tract of the eighth cranial nerve may cause an acute hearing loss in MS.  相似文献   
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This article presents the author's personal reflection on how her nursing practice was enhanced as a result of losing her voice. Surprisingly, being unable to speak appeared to improve the nurse/patient relationship. Patients responded positively to a quiet approach and silent communication. Indeed, the skilled use of non-verbal communication through silence, facial expression, touch and closer physical proximity appeared to facilitate active listening, and helped to develop empathy, intuition and presence between the nurse and patient. Quietly 'being with' patients and communicating non-verbally was an effective form of communication. It is suggested that effective communication is dependent on the nurse's ability to listen and utilize non-verbal communication skills. In addition, it is clear that reflection on practical experience can be an important method of uncovering and exploring tacit knowledge in nursing.  相似文献   
27.
A scalable small-signal and noise model of InP-InGaAs single heterojunction bipolar transistors was developed. Effects which become important at higher frequencies such as the correlation between base and collector current noise and frequency-dependent base current noise are taken into account. We will show that these effects are significant at frequencies higher than 40 GHz and can no longer be neglected. Our model also includes the effects of the different emission coefficients of the base and collector currents. Using this improved model, a direct-coupled, lumped broad-band amplifier was designed. We completely characterized the fabricated circuit with respect to small-signal, noise, and linearity behavior. A -3-dB bandwidth of 50 GHz with a dc gain of 9.8 dB and a gain-peaking of only 1.2 dB were achieved. All these values agree very well with the simulation results. The noise figure is 7.5 dB over a large frequency range. In the frequency range from 2 to 50 GHz, the third-order intercept point IP3 and 1-dB compression point at the output have values from 17 to 10 dBm and 3 to 0 dBm, respectively  相似文献   
28.
A technique of thoracic splanchnicectomy under video thoracoscopic control is reported. This simple and non aggressive procedure is indicated for very painful forms of pancreatic cancer and for some cases of chronic pancreatitis. It should relieve pain for a longer period than splanchnic nerve injection or radiotherapy.  相似文献   
29.
In many applications, the information required by the user cannot be found in just one source, but has to be retrieved from many varying sources. This is true not only of formatted data in database management systems, but also of textual documents and multimedia data, such as images and videos. We propose a mediator system that provides the end-user with a single query interface to an integrated view of multiple heterogeneous data sources. We exploit the capabilities of the MOMIS integration system and the MILOS multimedia data management system. Each multimedia source is managed by an instance of MILOS, in which a collection of multimedia records is made accessible by means of similarity searches employing the query-by-example paradigm. MOMIS provides an integrated virtual view of the underlying multimedia sources, thus offering unified multimedia access services. Two features are that MILOS is flexible—it is not tied to any particular similarity function—and the MOMIS’s mediator query processor only exploits the ranks of the local answers.  相似文献   
30.
1. To investigate whether microdialysis is suitable to monitor catecholamine in white adipose tissue of conscious rat and to assess eventual differences in norepinephrine (NE) interstitial levels, two groups of 12 male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats, 14-16 weeks old, were compared. 2. A flexible microdialysis probe was implanted subcutaneously in the parascapular region, and perfused with Ringer solution (flow rate: 2.0 mu L/min). After a 20 min equilibration period, NE levels were monitored over a 120 min period; then, tyramine hydrochloride (0.1 nmol/min) was perfused for 80 min. Dialysates from each 20 min collection period were analysed by HPLC with electrochemical detection for NE. 3. Basal levels of NE (adjusted for the recovery) were higher in SHR compared to WKY (1210.0 +/- 140.5 pg/mL dialysate vs 573.3 +/- 75.8 pg/mL dialysate; P < 0.001, ANOVA). In both strains tyramine perfusion increased NE concentration in dialysates; the net (i.e. baseline subtracted) NE output was lower (76.3 pg/h, s.e.m. 22.3) in SHR compared with that shown by WKY rats (201.0 pg/h, s.e.m 18.4, P < 0.01). 4. The increased basal levels of NE observed in SHR are associated with a blunted response to tyramine challenge. Since tyramine is known to cause NE release from the cytosol but not from vesicle stores, such a blunted response is consistent with an increased turnover rate of NE or with an accelerated uptake in pre-synaptic vesicles which, together with the higher basal levels, would suggest increased noradrenergic activity.  相似文献   
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