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901.
902.
The effects of dilute additions of titanium up to 0.20 wt pct on the solubility of nitrogen in two complex Fe−Cr−Ni alloys were examined over the temperature range 1450 to 1600°C. Sieverts' law was obeyed by all titanium-bearing alloys up to some nitrogen pressure below one atmosphere. ‘Breaks’ in each solubility plot were observed that corresponded to the formation of titanium nitride. Titanium additions were observed to lower the nitrogen solubility in each group of alloys. This effect is opposite to that previously observed in pure iron. Calculated values of the solubility product (pct Ti) (pct N) for TiN formation in each alloy increased with rising melt temperature.  相似文献   
903.
Clinical trials of inactivated hepatitis A vaccine Hep-A-in-Vac demonstrated its specific safety and moderate reactogenicity, manifesting by short-term fibrillar twitching of musculus deltoideus at the site of injection. After a course of three immunizations 87.5% seronegative vaccines developed a high level of specific antibodies to hepatitis A virus with at least 100 reverse values of titers. In controls antibody titers remained seronegative in 90% cases. These data indicate evident immunologic activity of Hep-A-in-Vac vaccine.  相似文献   
904.
A model of acute spinal and phantom pain syndromes caused by the formation of an abnormally increased excitation generator (AIEG) in the system of dorsal horns of the spine was used to study the effects of sodium valproate when used chronically in the phantom pain syndrome, when given in a single dose in the acute pain syndrome and when applied to the spine with disinhibitors inducing the pain syndrome. It was shown that during chronic administration sodium valproate produced a stress-preventive action, but failed to affect pain sensation and to prevent the development of the pain syndrome. When used in the acute pain syndrome, sodium valproate had a marked analgesic effect, and when applied to the spine it substantially reduced the manifestations of the pain syndrome. The action of sodium valproate on the AIEG can be accounted for by the higher GABA level that results in the hyperpolarization of neurons which are a part of AIEG. When the latter is formed and operates in acute and chronic pain syndromes there are differences in the functional activity of the neurochemical structures responsible for the realization of pain reaction components. This is suggested by varying effects of sodium valproate on pain sensation during acute and chronic experiments.  相似文献   
905.
Here we describe the cloning of a full-length cDNA encoding a neutrophil chemoattractant peptide, ENA-78, from human platelets. The cDNA encodes a predicted sequence of 114 amino acids and contains the Cys motif C-X-C found in other members of the alpha-chemokine family which also includes interleukin 8 (IL-8). ENA-78 has a high degree of sequence identity with other platelet-derived chemokines which also share overlapping chemotactic activities such as GRO alpha and the neurophil-activating peptide 2 (NAP-2; derived by proteolytic cleavage of the connective-tissue-activating peptide III (CTAP-III)).  相似文献   
906.
BACKGROUND: Uncontrolled studies suggest that a combination of chemotherapy and radiotherapy improves the survival of patients with esophageal adenocarcinoma. We conducted a prospective, randomized trial comparing surgery alone with combined chemotherapy, radiotherapy, and surgery. METHODS: Patients assigned to multimodal therapy received two courses of chemotherapy in weeks 1 and 6 (fluorouracil, 15 mg per kilogram of body weight daily for five days, and cisplatin, 75 mg per square meter of body-surface area on day 7) and a course of radiotherapy (40 Gy, administered in 15 fractions over a three-week period, beginning concurrently with the first course of chemotherapy), followed by surgery. The patients assigned to surgery had no preoperative therapy. RESULTS: Of the 58 patients assigned to multimodal therapy and the 55 assigned to surgery, 10 and 1, respectively, were withdrawn for protocol violations. At the time of surgery, 23 of 55 patients (42 percent) treated with preoperative multimodal therapy who could be evaluated had positive nodes or metastases, as compared with 45 of the 55 patients (82 percent) who underwent surgery alone (P<0.001). Thirteen of the 52 patients (25 percent) who underwent surgery after multimodal therapy had complete responses as determined pathologically. The median survival of patients assigned to multimodal therapy was 16 months, as compared with 11 months for those assigned to surgery alone (P=0.01). At one, two, and three years, 52, 37, and 32 percent, respectively, of patients assigned to multimodal therapy were alive, as compared with 44, 26, and 6 percent of those assigned to surgery, with the survival advantage favoring multimodal therapy reaching significance at three years (P=0.01). CONCLUSIONS: Multimodal treatment is superior to surgery alone for patients with resectable adenocarcinoma of the esophagus.  相似文献   
907.
PURPOSE: We defined the efficacy of radiotherapy for the treatment of high grade (Gleason scores 8 to 10) adenocarcinoma of the prostate. MATERIALS AND METHODS: A total of 50 patients underwent radiotherapy with curative intent for clinically localized prostate cancer with Gleason scores of 8 to 10 at 1 of 4 facilities affiliated with the University of California San Francisco. Patients were considered to have biochemical failure if they had a significant increase in prostate specific antigen (PSA) of 0.5 ng./ml. per year, an increase in PSA to greater than 1.0 ng./ml. or a positive biopsy. RESULTS: Among the 50 patients median PSA was 22.7 ng./ml. (range 1.3 to 93.4). Tumors were clinical stage T1 or T2 in 46% of the cases and stage T3 or T4 in 54%. The overall actuarial probability of freedom from biochemical failure at 4 years was 23%. In a multivariate analysis including all patients pretreatment PSA was the only predictor of PSA failure, with 64% free of progression if the pretreatment PSA was 10 ng./ml. or less compared to only 16% at 3 years if PSA was more than 10 ng./ml. (p = 0.01). In a multivariate analysis restricted to patients with PSA less than 20 ng./ml. 83% of those treated to more than 71 Gy. were free of progression compared to 0% for those treated to less than 71 Gy. (p = 0.03). In a multivariate analysis PSA 10 ng./ml. or less (related risk 11.4, p = 0.02), T stage 1 or 2 (relative risk 3.8, p = 0.05) and radiation dose more than 71 Gy. (relative risk 4.0, p = 0.06) were associated with a favorable outcome. CONCLUSIONS: At 4 years the freedom from PSA failure following radiotherapy for high grade prostate cancer was comparable to previously reported surgical series. The high failure rate among patients with PSA greater than 20 ng./ml. suggests that these patients should be considered for investigational approaches. The apparent improvement in freedom from progression with the use of higher doses provides reason for optimism.  相似文献   
908.
Neurosurgical patients in pentobarbital coma are a complex nutrition support population. Physiologic changes associated with the primary injury to the brain, combined with the pharmacodynamic influences of barbiturate therapy, contribute to the difficulties of initiating aggressive nutrition support. Early nutritional repletion is important to the overall outcome of traumatically injured patients. Consequently, factors that influence nutrition support decisions must be understood to assure appropriate intervention. The metabolic changes associated with traumatic head injury, pentobarbital therapy, and nutrition support strategies are reviewed.  相似文献   
909.
910.
Managing safety and quality through the red meat chain   总被引:1,自引:0,他引:1  
To successfully manage food safety and quality risks in meat production, a holistic approach is required. The ideal would be a fully integrated assurance system, with effective controls applied at all stages. However, the red meat industry is by nature somewhat fragmented, and a truly integrated system is not at present achievable in all but a few operations. This paper describes a variety of assurance initiatives, and explores how targeted research and development can be used to augment assurance programmes by providing underpinning knowledge, using the Australian beef and lamb industry as an example.  相似文献   
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