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This article introduces the basic principles of reading electrocardiograms (ECGs) for nurses who are unfamiliar with reading them. For more experienced practitioners there are a number of useful articles and books (e.g. Hampton, 1992a, b) that will help further their knowledge. The ECG records cardiac electrical activity as a graph; interpretation is illustrated here by sinus rhythm. A single ECG lead (lead II) is used throughout this article. Atrial fibrillation is described to show a contrasting dysrhythmia. Specific nursing care is suggested for patients being monitored or having ECGs taken.  相似文献   
3.
The authors, after some remarks on the pathophysiology of primary alkaline gastritis, analyze the main methods, available at present, for diagnosis; they particularly consider the importance of endoscopy and histology, gastroesophageal 24-hours pH-metry and 99mTc HIDA scintigraphy. Successively, they present the criteria for the identification of patients who will predictably benefit from surgical treatment, and examine advantages and limits of the two main corrective surgical techniques for the duodenogastric reflux in patients not previously operated on the gastrointestinal tract: duodenal extramucosal myotomy according to Mattioli, relatively easy to perform, and the "duodenal switch" according to De Meester, technically more complex, but pathophysiologically more acceptable, completely eliminating the duodenogastric reflux.  相似文献   
4.
The aim of the present work was to develop two products from blackberry juice by freeze and spray drying with potential use as food colorants or healthy ingredients. A characterization of the physical and functional properties of the powdered juices was done. Maltodextrin or a mixture of trehalose and maltodextrin were assessed as carrier matrices. Freeze-dried, maltodextrin-containing powders presented the best retention of bioactive compounds and antiradical activity; however, they showed a narrow relative humidity range for storage in the glassy state. Spray-dried powders showed better physical properties, bearing higher glass transition temperature and lower molecular mobility than freeze-dried formulations.  相似文献   
5.
德州仪器公司(TI)的IVC102精密积分器有高质量的内部电容.图1的电路可以用来测量非常高的Rx电阻值.一只精密差分放大器(TI的INA105)为Rx施加一个基准电压.积分期间,在IVC12的输出端产生一个负电压斜坡Vo.两只LM311将Vo的振幅与两个固定阈值作比较,产生两个数字信号:开始和停止.  相似文献   
6.
This second section is dedicated to gain more insight into the Voltage Division Position Sensitive Detector described in Part I of this work. Here, the discussion is taken from a design point of view. The linearity and rejection to light intensity variations are described on the practical situation of an incident light beam whose cross sectional dimensions could be negligible to the length of the sensor active area. The noise contribution due to the resistive nature of the detector is taken into account and discussed, too. According to the ideas here depicted, a sensor based on high-quality CVD-diamond film has been fabricated. The experimental results acquired for such specimens, under UV excimer laser or X-ray illumination, confirm the theoretical expectations.  相似文献   
7.
The aim of this work was to analyze the effect of UV-C radiation (fluence: 11.2 kJ/m2), with or without an anti-browning pretreatment containing 1% (w/v) ascorbic acid plus 0.1% (w/v) calcium chloride, on the linear viscoelastic properties (oscillatory shear and creep/recovery), instrumental texture (TPA), sensory texture and ultrastructure (ESEM, TEM) of cut apple. Changes in structural features and viscoelastic parameters were mainly evidenced after refrigerated storage. All samples showed a viscoelastic solid behavior with the storage modulus (G′) dominating the viscoelastic response. Overall, both dynamic moduli decreased, and instantaneous compliance (J0), decay compliances (J1 and J2) and fluidity significantly increased after treatments and storage at 5 °C, while retardation times were in general constant. Fracture properties proved to be the most highly correlated with sensory texture. The test panel only significantly differentiated stored untreated apple from the other samples regarding fracturability and juiciness. Mechanical spectra and creep parameters showed ability to evidence ultrastructural differences (rupture of membranes, swelling of cells, alteration of cell walls) in the surface of cut apples subjected to the different treatments.  相似文献   
8.
Site-directed mutagenesis on human cytidine deaminase (CDA)was employed to mutate specifically two highly conserved phenylalanineresidues, F36 and F137, to tryptophan; at the same time, theunique tryptophan residue present in the sequence at position113 was mutated to phenylalanine. These double mutations wereperformed in order to have for each protein a single tryptophansignal for fluorescence studies relative to position 36 or 137.The mutant enzymes thus obtained, W113F, F36W/W113F and F137W/W113F,showed by circular dicroism and thermal stability an overallstructure not greatly affected by the mutations. The titrationof Trp residues by N-bromosuccinimide (NBS) suggested that residueW113 of the wild-type CDA and W36 of mutant F36W/W113F are buriedin the tertiary structure of the enzyme, whereas the residueW137 of mutant F137W/W113F is located near the surface of themolecule. Kinetic experiments and equilibrium experiments withFZEB showed that the residue W113 seems not to be part of theactive site of the enzyme whereas the Phe/Trp substitution inF36W/W113F and F137W/W113F mutant enzymes had a negative effecton substrate binding and catalysis, suggesting that F137 andF36 of the wild-type CDA are involved in a stabilizing interactionbetween ligand and enzyme.  相似文献   
9.
Three antigens of Candida albicans were comparatively evaluated to their ability to elicit delayed hypersensitivity (DH) responses in the mouse footpad test, using alloxan-diabetic and normal mice which were primed with heat-killed C. albicans in complete Freund adjuvant. These antigens were: (1) a preparation of sonically disrupted heat-killed cells; (2) a preparation of soluble cytoplasmic material remaining in the supernatant of a broken-cell suspension centrifuged at 100,000 g; (3) a preparation obtained by extraction of pulverized defatted cells with dilute phenol and sodium bicarbonate in water. After separation by polyacrylamide gel electrophoresis, the major components of soluble cytoplasmic material and dilute phenol extract were identified as a 43-kD protein, and glycoproteins of 21, 27 and 38 kD, respectively. Fifty-eight CD-1 outbred mice, which had received a single intravenous injection of alloxan followed by a 28-day rest period, were randomized with normal littermates to distinct experimental groups. Seven days after sensitization, mice were injected with one of the antigens in the right rear footpad and saline in the left rear footpad and the net specific increase in footpad thickness determined 24 and 48 h later. All three antigens elicited significant responses in sensitized normal mice. The responses of sensitized diabetic mice were clearly inferior to those of sensitized normal mice when heat-killed cells and soluble cytoplasmic material were used. Dilute phenol extract elicited equivalent responses at 24 and 48 h in both primed diabetic and normal mice.  相似文献   
10.
The study aimed to evaluate, with regard to the human nutrition, the lipid profile of meat and backfat from gilts and barrows of the Italian autochthonous genotype Casertana and its crossbreed (Casertana×Large White) slaughtered at two different live weights. Meat from the Casertana cross was nutritionally comparable to that from the purebreed and both would be considered healthy, irrespective of sex and weight, due to the relatively low levels of intramuscular lipids and cholesterol. Muscle cholesterol was considerably lower in the heavy pigs than in the light ones and, as weight increased, cholesterol decreased but only in gilts. Females supply meat with higher polyunsaturated fatty acids (PUFA) and slightly lower saturated fatty acids (SFA) respect to barrows and, thus, higher PUFA/SFA ratio. Casertana crossbreds can represent a good alternative to pure Casertana, mainly in the production of Colonnata lard, due to the better fatty acid profile of the subcutaneous adipose tissue. From the nutritional point of view, the optimal slaughtering weight was about 150kg for both genotypes. Heavy pigs, compared to the light ones, produced loin with lower atherogenic and thrombogenic indexes, lower SFA/unsaturated fatty acids ratio, and higher PUFA/SFA ratio.  相似文献   
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