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51.
During cardiopulmonary bypass or long-term extracorporeal life support, foreign surface induced platelet deposition in the oxygenator causes deterioration of gas exchange. In this study, the authors evaluated the effectiveness of nitric oxide (NO) in reducing the adhesion of platelets in whole blood to the surface of hollow fiber membranes. For this purpose, a test chamber was designed consisting of a gas exchanger with ten mitsubishi multi-layered composite hollow fibers (MHF: 257 mm OD; 203 mm ID; 70 mm length) and a polypropylene tube (16 mm OD; 100 mm length). Pure N2 (control) or nitric oxide (NO) (100 ppm, 200 ppm in N2) were delivered into the test chamber previously filled with 13 ml human whole blood. Platelet counts and platelet factor 4 (PF4), as a measure of platelet activation, were measured before and after either 1 or 2 hr of testing, and fibers were observed under scanning electron microscopic study (SEM) after each experiment. In the control and 100 ppm NO groups, platelet counts decreased and the level of PF4 increased during the 1 hr period. In the 200 ppm NO group, almost no platelet deposition could be observed on the surface of fibers under SEM. In conclusion, NO flow through hollow fiber membranes can markedly reduce platelet adhesion. Additional quantitative studies should define the optimal concentration for this effect and determine if this finding could improve oxygenator function, especially under conditions of long-term support.  相似文献   
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An orally applicable fermentation product of wheat germ containing 0.04% substituted benzoquinone (MSC) was invented by Hungarian chemists under the trade--name of AVEMAR. The following biological effects of this product were observed. Oral administration (3 g/kg body weight) of MSC enhances blastic transformation of splenic lymphocytes of mice. The same treatment shortens the survival time of skin grafts in co-isogenic mouse skin transplantation model, which points to immune-reconstructive effect of MSC. Highly significant anti-metastatic effect of MSC was observed in three metastasis models (3LL-HH, B16, HCR-25). The antimetastatic activity of MSC--besides the immune reconstitution--may also due to the cell-adhesion inhibitory, cell proliferation inhibitory, apoptosis-enhancing and antioxidant effects, which were also observed in our in vitro experiments. Based on the biological effects of MSC--which is non-toxic, according to subacute toxicology studies--this product may be used as an adjuvant in the therapy of malignant neoplasia and other diseases caused by or following immunedeprivation.  相似文献   
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OBJECTIVE: Patients with primary head and neck neoplasia can present during follow-up with suspected recurrence, and both fine needle aspiration biopsy (FNAB) and fluoride-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scan are available methodologies for evaluating these patients. Our objective was to retrospectively correlate patients who underwent both FNAB and FDG-PET scan in order to assess the possibility of recurrent neoplasia. STUDY DESIGN: The cytopathology files at Saint Louis University Health Sciences Center were retrospectively searched for patients with known primary head and neck malignancies beginning in 1995. Suspected recurrence and local metastases evaluated by both FNAB and FDG-PET scan were correlated. RESULTS: Twenty-eight patients received a combined total of 37 FNABs with concurrent FDG-PET scans. The majority of patients had primary oropharyngeal squamous cell carcinoma with intermixed, single cases of other primary head and neck neoplasms. Thirty of the 32 aspirates with recurrent or locally metastatic disease had combined positive findings by both FNAB and FDG-PET scan, yielding a sensitivity of 94%. One nonspecific and one negative FDG-PET scan came from a patient who had disease confirmed by FNAB. Five patients had negative findings by both methods that were supported by the subsequent clinical course. CONCLUSION: FNAB can provide confirmatory evidence of disease in a clinically suspicious abnormality with nonspecific FDG-PET results. FNAB and FDG-PET are highly sensitive for tumors in cases of clinically suspected recurrence and locally metastatic disease.  相似文献   
54.
PURPOSE: To determine the treatment outcome of standard acute myeloid leukemia (AML)-type chemotherapy in a subset of patients with newly diagnosed myelodysplastic syndromes (MDS) compared with that of patients with de novo AML as defined using French-American-British (FAB) criteria. In addition, to determine the pretreatment variables having prognostic significance for treatment outcome in patients with MDS. PATIENTS AND METHODS: Nine hundred seven newly diagnosed patients with no history of cytopenias having a local institutional de novo AML successfully karyotyped and treated on Cancer and Leukemia Group B (CALGB) protocols for AML from 1984 to 1992. Thirty-three of the 907 patients were reclassified as having MDS on central pathology review using FAB criteria and form the basis of this analysis. RESULTS: The treatment outcomes for patients with MDS and AML were similar; the complete remission (CR) rate was 79% and 68%, respectively (P = .37); median CR duration was 11 and 15 months, respectively (P = .28); and median survival was 13 and 16 months, respectively (P = .72). For the MDS patients, there were no prognostic variables for CR rate identified. For CR duration, only the Sanz classification had prognostic value. The prognostic factors for survival in a univariate analysis included age, WBC count, Sanz classification, and percent blood blasts. In a proportional hazards analysis of survival, age greater than 60 years and WBC less than 2.6 x 10(9)/L were adverse prognostic factors. CONCLUSION: In patients with no known history of cytopenias who are treated intensively at diagnosis, the FAB distinctions between MDS (refractory anemia with excess blasts and refractory anemia with excess blasts in transformation) and AML appear to have little therapeutic relevance.  相似文献   
55.
OBJECTIVE: To investigate the role of tumor persistence in patients submitted to irradiation therapy and radical hysterectomy. DESIGN: A retrospective analysis of prognostic factors. LOCATION: Hospital A.C. Camargo, S?o Paulo, Brazil, a private non-profitmaking foundation and tertiary referral centre. PATIENTS: A total of 629 cases of invasive squamous cell carcinoma of the cervix were studied. Criteria for inclusion in the study were: confirmed histological diagnosis of squamous cell carcinoma and no previous treatment (except for preoperative radiotherapy carried out at the Hospital A.C. Camargo itself). At the end of the follow-up period, 410 patients (65%) had no evidence of disease and 219 (34.8%) had died because of the tumor. INTERVENTION: The patients were submitted to radical surgery and radiation therapy, separately or in combination between 1953 and 1982. MAIN OUTCOMES MEASURES: Multivariate analysis of the different variables was performed according to the Cox regression method. RESULTS: The variables of prognostic value were, in decreasing order of importance: the decade of patient admission (p = 0.0001), the modality of therapy employed (p = 0.0005), the presence of residual tumor in the surgical specimens (p = 0.0055) and the clinical stage of the disease (p = 0.0575). CONCLUSION: Radiation therapy controlled a considerable number of local tumors and pelvic lymph nodes but not all of them in every patient. There is a specific group of patients for whom radical surgery is necessary to achieve control of the disease.  相似文献   
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Listeria monocytogenes is an intracellular bacterial pathogen that elicits a strong cellular immune response following infection and therefore has potential use as a vaccine vector. However, while infections by L. monocytogenes are fairly rare and can readily be controlled by a number of antibiotics, the organism can nevertheless cause meningitis and death, particularly in immunocompromised or pregnant patients. We therefore have endeavored to isolate a highly attenuated strain of this organism for use as a vaccine vector. D-Alanine is required for the synthesis of the mucopeptide component of the cell walls of virtually all bacteria and is found almost exclusively in the microbial world. We have found in L. monocytogenes two genes that control the synthesis of this compound, an alanine racemase gene (dal) and a D-amino acid aminotransferase gene (dat). By inactivating both genes, we produced an organism that could be grown in the laboratory when supplemented with D-alanine but was unable to grow outside the laboratory, particularly in the cytoplasm of eukaryotic host cells, the natural habitat of this organism during infection. In mice, the double-mutant strain was completely attenuated. Nevertheless, it showed the ability, particularly under conditions of transient suppression of the mutant phenotype, to induce cytotoxic T-lymphocyte responses and to generate protective immunity against lethal challenge by wild-type L. monocytogenes equivalent to that induced by the wild-type organism.  相似文献   
59.
A random sample (N = 197) of supported employees with mental retardation was examined in a longitudinal study. Results indicate that intelligence, prior earnings, and federal job subsidy predicted future earnings. Statistical controls applied to the stratified sample show that job placement, job type, subsidy, and means of transportation had little influence on earnings.  相似文献   
60.
Mouse hepatitis virus [MHV], the coronavirus of the mouse, is the most common viral pathogen in contemporary laboratory mouse colonies throughout the world. It is highly contagious with variable clinical manifestations. The majority of infections are subclinical, but can still significantly influence biological responses, thus interfering with research, mainly in the field of immunology. MHV has been intensively studied from a number of research perspectives and has become the prototype for studying the molecular biology of coronaviruses. MHV contains a single-stranded, positive-sense RNA genome ranging from 27 to 31 kb, which is divided into seven genes. Virions consist of four to five structural proteins. There are many MHV strains that vary in virulence, organotropism and cell tropism, and are constantly evolving by naturally occurring mutation and recombination. Based on pathogenesis studies MHV strains are usually grouped according to their primary tissue tropism into two biotypes: polytropic and enterotropic. Enterotropic strains of MHV replicate in the intestinal mucosa and only rarely spread to other tissues. No morphological structure of the virion has as yet been identified that is responsible for enterotropism. The course of an MHV infection is dependent on the virus strain and host factors. Generally, MHV causes an acute, self-limiting infection which is inapparent in adult mice. Neonates are highly susceptible to disease and show high mortality. In an enzootically infected colony, however, they are protected by maternally derived passive immunity. Detection of MHV infections depends on serological screening of colonies. MHV is controlled by culling and rederivation of the affected colony using hysterectomy or embryo transfer or by elimination through cessation of breeding.  相似文献   
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