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61.
联合营销在北京森林旅游市场中的应用   总被引:1,自引:0,他引:1  
通过对北京市森林旅游区市场营销现状的调查和存在问题的分析,针对北京森林旅游市场的实际,提出了一种新的营销模式——联合营销。其具有低投入、高回报、影响广泛、利于资源整合等特点。  相似文献   
62.
Canine distal renal tubular acidosis and urolithiasis   总被引:1,自引:0,他引:1  
Distal RTA is characterized by decreased distal renal tubular hydrogen ion secretion, decreased ability to acidify urine, hypercalciuria, hyperphosphaturia, hypocitraturia, and metabolic acidosis. Because of the resulting alterations in urine composition and pH, patients with distal RTA are predisposed to urolithiasis and renal calcification. Diagnosis of distal RTA is important because it is a potentially reversible disorder that, left untreated, may cause nephrocalcinosis, recurrent urolith formation, moderate to severe metabolic acidosis, and renal failure.  相似文献   
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Intrajugular injection of a purified E. coli lipopolysaccharide induced a biphasic fever in sheep after a latent period of 12 to 20 min. The changes in the blood flow from the liver and from the viscera drained by the portal vein were: (a) in the latent period, decreases in total hepatic blood flow (THF) due to decreased portal venous blood flow (PVF); (b) during the first febrile phase, increases in THF due to increased hepatic arterial blood flow and, (c) in the second febrile phase, increases in THF due to decreased PVF. Although there were large variations in the oxygen supply to the viscera drained by the portal vein and to the liver, there were relatively small or no changes in their oxygen consumption.  相似文献   
68.
This study evaluates the ability of selenium (Se) supplementation to prevent experimental copper (Cu)-induced hepatocellular damage. Weanling male Fischer 344 rats were randomly assigned to groups of 15, 3 groups (A,B,C) were fed Cu-loaded diets (containing 2000 microg/g copper, added as CuSO4) and different levels of Se (added as Na2SeO3 x 5H2O) as follows: A) Cu-loaded/Se adequate diet (0.4 microg/g Se, fed basis); B) Cu-loaded/Se-supplemented diet (2 microg/g Se); and C) Cu-loaded/Se-deficient diet (< 0.2 microg/g). Three additional groups (D,E,F) were fed diets containing adequate levels of Cu (14 microg/g Cu, fed basis) and different levels of Se as follows: D) Cu-adequate/Se-adequate diet; E) Cu-adequate/Se-supplemented diet (2 microg/g Se); and F) Cu-adequate/Se-deficient (< 0.2 microg/g) diet. After 4, 8, and 12 weeks on the experimental diets, liver samples were processed for histology, histochemistry, metal analysis, glutathione peroxidase (GSH-Px) measurement, and quantification of malondialdehyde (MDA). Morphologic changes characteristic of Cu-associated hepatitis, without an increase in hepatic MDA levels, were seen in all Cu-loaded rats in each sampling. Similar changes occurred in rats fed Se-adequate, Se-supplemented and Se-deficient diets. This study demonstrates that Fischer 344 rats fed 2000 microg/g Cu develop morphologic changes due to Cu toxicity without evidence of lipid peroxidation. Furthermore, Se supplementation does not result in protection against Cu-induced liver injury.  相似文献   
69.
叙述了用AutoCAD2 0 0 0进行机械二维图形设计的各种技巧 ,并详细介绍了绘图时的环境设置、图形绘制、标注及绘图输出等。  相似文献   
70.
Objective: To evaluate the ability of capnography to document proper placement of nasoesophageal (NE) and nasogastric (NG) feeding tubes. This study was conducted in 3 phases. Phase I of this study was designed in order to test the efficacy of capnography to distinguish placement of a feeding tube in the alimentary tract versus the respiratory tract. Phase II was designed in order to document that carbon dioxide (CO2) could be measured through a polyvinyl chloride (PVC) feeding tube. Phase III was performed in order to evaluate the technique of continuous monitoring during insertion of the feeding tube into the esophagus and stomach as would be performed during a clinical‐tube placement. Design: Prospective study. Setting: Research laboratory. Animals: 24 adult dogs. Interventions: In Phase I, sedated dogs were instrumented with an intratracheal catheter and an 8 French feeding tube placed nasally into the distal esophagus and later advanced into the stomach. In Phase II, dogs were anesthetized and an 8 French feeding tube was placed down the endotracheal tube, then into the esophagus and later advanced into the stomach. In Phase III, sedated dogs were instrumented with an 8 French feeding tube inserted intranasally and then advanced to the level of the nasopharynx, distal esophagus and, lastly, the stomach. Fluoroscopy was used in order to determine location of the feeding tube. Measurements and main results: Phase I measurements included respiratory rate and CO2 from the trachea, esophagus, and stomach and pH of gastric fluid sample. Phase II measurements included respiratory rate and CO2 from the endotracheal tube, feeding tube in the endotracheal tube, feeding tube in the distal esophagus, and feeding tube in the stomach. Phase III data collection included respiratory rate and CO2 as the tube was passed through the nasal cavity, nasopharynx, esophagus and stomach. Phase I fluid samples were collected from 5 of the 9 dogs and had pH values from 1.68 to 4.20. In both phases, values for the respiratory rate and CO2 from the esophagus and stomach were 0 ± 0, significantly lower (P < 0.001) than the values from the trachea. In Phase II, there was no significant difference between the respiratory rates (P = 0.886) and CO2 (P = 0.705) readings obtained from the endotracheal tube compared to readings from the feeding tube in the endotracheal tube. In Phase III, there was a significant difference (P < 0.001) between the respiratory rates and CO2 readings obtained from the nasal cavity and the nasopharynx when compared to those readings obtained from the esophagus and stomach. Measurement of CO2 and respiratory rate resulted in a reading of 0 every time the feeding tube was in the esophagus or stomach. Conclusions: Capnography may be used in order to detect airway placement of NE and NG tubes.  相似文献   
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