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991.
We investigated whether the polymerase chain reaction (PCR) performed with aspirates of bone marrow or lymph node can be used as a test of cure of visceral leishmaniasis (VL). Sixty-one VL patients who had received supervised treatment with sodium stibogluconate in the health centre of Médecins sans Frontières (MSF) Holland in Um-Kuraa, eastern Sudan, were studied. Immediately after treatment, no parasite could be demonstrated by microscopy in aspirates of bone marrow or lymph node. In contrast, PCR detected Leishmania deoxyribonucleic acid in 50 of the 61 lymph node aspirates (82%). Forty-nine patients were examined 3 and 6 months later; the other 12 were reported to be alive but had left the area. With 10 of these 49 patients, the PCR was negative and the patients remained free from signs and symptoms of VL; they were apparently cured. Of the 39 patients with a positive PCR after treatment, 14 (36%) developed post kala-azar dermal leishmaniasis and 9 (23%) had a recurrence of VL symptoms with reappearance of parasites in the aspirates. Four relapsed patients subsequently died of VL. We concluded that the PCR on lymph node aspirates can be used to assess treatment and cure of VL. The fact that 23 of 49 patients who received standard supervised treatment were not completely cured indicated that there is a need to investigate extended or alternative treatments.  相似文献   
992.
993.
Maximizing the response of selection with a predefined rate of inbreeding   总被引:4,自引:0,他引:4  
Automated analytical instruments for enumerating indicator organisms and diagnostic test kits for pathogens can be used in food microbiology to screen samples and to replace conventional cultural and confirmation steps. Such methods are now available for rapid detection or estimation of groups of (indicator) organisms, pathogenic micro-organisms, bacterial toxins and mycotoxins, and molds. These alternative methods can be classified by the principles on which they are based: modified conventional methods, instrumental measurement of bacterial metabolism, bioluminescence, immunological techniques, DNA techniques, and combinations of these techniques. To meet user expectations, test kits must be accurate, sensitive, specific, rapid (24 h or less), easy to use, and labor-saving. They must also offer the possibility of computerization, a low detection limit, and low investment and running costs. The paper compares the ability of alternative methods to meet these criteria. Variations were found, depending on the techniques used and the target organism of the analysis. Economic reasons can determine whether alternative methods can be used routinely. Adoption of these screening systems also can be hampered by lack of internationally coordinated and accepted validation protocols.  相似文献   
994.
The lutropin/choriogonadotropin receptor is a seven-helix transmembrane (TM) receptor. A unique feature of TM helices is the content of Pro, which generally is absent in alpha helices of globular proteins. Because Pro disrupts helices and introduces a approximately 26 degrees kink, it has been speculated that Pro plays a crucial role in the structure of TM helices, exoloops, and cytoloops of TM receptors. To examine the roles of the five TM Pros of the lutropin/choriogonadotropin receptor, these residues were individually substituted. Mutant receptors were examined for surface expression, hormone binding, and cAMP induction. Surface expression was monitored after introducing the flag epitope into the receptors. Flag epitopes slightly affected cAMP induction but not hormone binding or surface expression of receptors as monitored by immunofluorescence microscopy and 125I-anti-flag antibody. The results indicate that Pro479 in TM 4 and Pro598 in TM 7 play important yet contrasting roles. Pro479 is crucial for hormone binding at the cell surface but not after solubilization of the receptor. This is more likely due to the Pro side chain than the Pro-induced kink. Pro598 is important for surface expression. The kinks of Pro463 of TM 4, Pro562 of TM 6, or Pro591 of TM 7 are not important because the substitution of Phe for these residues did not significantly impact surface expression, hormone binding, and cAMP induction.  相似文献   
995.
BACKGROUND: Treatment of acute renal allograft rejection with the monoclonal antibody (mAb) OKT3 has been shown to be superior to treatment with polyclonal antisera. To date, only OKT3 has demonstrated consistent efficacy in reversing rejection crisis. METHODS: From 1989 to 1993, a phase II trial comparing the mAb T10B9.1A31 (T10B9) with OKT3 for treatment of acute cellular rejection in renal allograft recipients was done at the University of Kentucky. We collected data from 178 patients potentially eligible to enter the study; 48 never rejected, 9 refused, 13 could not be biopsied, 16 received methylprednisolone, and 11 received antithymocyte globulin or OKT3. Altogether, 81 patients entered the study, 76 of whom were able to be evaluated. Patients with biopsy-confirmed acute rejection were randomly assigned to T10B9 or OKT3 for at least 10 days. RESULTS: Demographically, there was no difference between the T10B9 or OKT3 cohorts. Actuarial graft survival at 4 years was 87% for patients receiving T10B9, 79% for those receiving OKT3, and 89% for those receiving both mAbs (P=0.55). Patient survival at 4 years was 94% for T10B9, 100% for OKT3, and 89% for both mAbs (P=0.45). Mean creatinines of the cohorts were no different at 1, 6, 12, 24, and 36 months. There was less cytokine nephropathy (P<0.001) observed in patients receiving T10B9. Untoward gastrointestinal, neurological, respiratory, and febrile effects were significantly more frequent in the OKT3 cohort after the first dose (day 0) and with later (day 1-9) administration. Cytokine levels (tumor necrosis factor alpha and interferon gamma) measured 2 hr after the first dose were three to six times higher in patients treated with OKT3 than in those treated with T10B9 (P<0.005). Infectious complications were not significantly different, although serious infections occurred only in patients receiving OKT3. No cases of posttransplant lymphoproliferative disorder were seen in either cohort. Human anti-mouse antibody development was as follows: titer 1:100, 30% T10B9, 42% OKT3; titer 1:1000, 3% T10B9, 3% OKT3. There was no cross-reactivity with OKT3 in patients treated with T10B9, and there was only 9.7% cross-reactivity to T10B9 in patients treated with OKT3. CONCLUSIONS: T10B9 provides treatment for renal allograft acute cellular rejection as effective as that of OKT3 with fewer untoward effects, less cytokine release and nephropathy, fewer serious infections, and without increased development of human anti-mouse antibody. The lack of cross-reactivity offers an alternative therapy should the first mAb fail or re-rejection occur. A phase III trial should be initiated in renal allograft recipients, and phase I and phase II trials should be initiated in other solid-organ transplantations.  相似文献   
996.
Helicobacter pylori infection is mainly acquired in childhood, and studies on the epidemiology of this infection depend on the availability of a noninvasive diagnostic test for use in children. The aim of this study was to determine whether the carbon 13-labeled urea breath test (UBT) can be used in children by evaluating: (1) its sensitivity and specificity compared with either culture or both rapid urease test and histologic examination, (2) whether a test meal or a prolonged fast is required, (3) the usefulness after treatment for H. pylori. Eighty-eight children (mean age, 10.6 +/- 4.19 years) who were undergoing upper endoscopy were studied while fasting, not fasting, and after treatment. Children were given 50 mg of 13C-urea if they weighed less than 50 kg or 75 mg of 13C-urea if they weighed more than 50 kg with 50 mg of a glucose polymer solution in 7.5 ml of water. Breath samples were collected at baseline and at 15, 30, 45, and 60 minutes. In 63 fasting children the UBT was 100% sensitive and 97.6% specific at 30 minutes with a cutoff value of 3.5 delta 13CO2 per mil. Nonfasting tests in 23 children, performed between 1 and 2 hours after their usual meal, were 100% sensitive and 91.6% specific. In 13 children fed directly before the UBT, the sensitivity of the test was reduced to 50%. Thirty minutes was the optimal sampling time. There was a significant decrease in specificity when samples were obtained at 15 minutes, possibly caused by the interference of oral urease-producing organisms. The test was 100% sensitive and specific in 20 children after treatment for H. pylori infection. The UBT is a highly sensitive and specific test for the diagnosis of H. pylori infection in children. Neither a prolonged fast nor a test meal is required.  相似文献   
997.
There has been no in vivo validation of the use of transthoracic echocardiography to measure distal left anterior descending coronary artery (LAD) diameter. We therefore undertook transthoracic echocardiography on 65 male patients immediately before cardiac catheterization to compare echocardiographic and angiographic findings. The distal LAD was successfully imaged in 41 (63%) patients; 29 of these had an angiographically normal distal LAD as assessed by an independent cardiologist and formed the study group. Transthoracic echocardiographic and quantitative coronary angiographic measurements of distal LAD diameter were made. Echocardiographic measurements ranged from 0.14 to 0.28 cm (mean 0.20 cm). Angiographic results ranged from 0.12 to 0.28 cm (mean 0.195 cm). Correlation between techniques was good (r=.925). The maximum discrepancy between transthoracic echocardiography and quantitative coronary angiography was 0.03 cm. Limits of agreement were +0.032 to -0.024 cm. We conclude that transthoracic echocardiography is a valid technique for measurement of distal LAD diameter.  相似文献   
998.
OBJECTIVES: To characterize progressive patterns of dehydration, stress responses, and water consumption in horses transported long distances in hot weather and to evaluate various measurements in detecting dehydration and stress in transported horses. DESIGN: Prospective study. ANIMALS: 30 mature, healthy horses. PROCEDURE: The following 4 treatment groups were studied: horses that were penned and offered water every 5 hours (n = 5), horses that were penned and not offered water (5), horses that were transported in a truck and offered water every 5 hours (10), and horses that were transported and not offered water (10). The study commenced after 6 hours of water deprivation. Every 4 hours, the truck returned to the pen area and body weights were measured, physical examinations were performed, and blood samples were obtained. During this 1-hour period, water was offered to some horses, depending on treatment group. RESULTS: After 24 hours of transport, 3 horses were judged unable to continue and the study was terminated. Horses that were penned and offered water drank a mean of 38.2 L and horses that were transported and offered water drank 20.9 L, but some of the latter horses did not drink until after 19 or 24 hours of transport. In horses that were transported or penned and not offered water, serum electrolyte concentrations were greater than reference range values by 19 hours. Most horses that were transported and offered water consumed adequate water to postpone severe dehydration beyond 24 hours. CLINICAL IMPLICATIONS: Tame horses in good condition and initially deprived of access of water for approximately 6 hours can be transported in groups in open trailers during hot, humid conditions for up to 24 hours before dehydration and fatigue become severe. Rectal temperature and appearance of the horses were the most useful measures for determining crisis situations.  相似文献   
999.
Despite its name, the actin-binding protein lymphocyte-specific protein1 (LSP1) is found in all hematopoetic cells, and yet its role in cell function remains unclear. Recently, LSP1 was identified as the 47-kD protein overexpressed in the polymorphonuclear neutrophils of patients with a rare neutrophil disorder, neutrophil actin dysfunction with abnormalities of 47-kD and 89-kD proteins (NAD 47/89). These neutrophils are immotile, defective in actin polymerization in response to agonists, and display distinctive, fine, "hairlike" F-actin-rich projections on their cell surfaces. We now show that overexpression of LSP1 produces F-actin bundles that are likely responsible for the morphologic and motile abnormalities characteristic of the NAD 47/89 phenotype. Coincident with LSP1 overexpression, cells from each of several different eukaryotic lines, including a highly motile human melanoma line, develop hairlike surface projections that branch distinctively and contain F-actin and LSP1. The hairlike projections are supported at their core by thick actin bundles, composed of actin filaments of mixed polarity, which periodically anastomose to generate a branching structure. The motility of the melanoma cells is inhibited even at low levels of LSP1 expression. Therefore, these studies show that overexpression of LSP1 alone can recreate the morphologic and motile defects seen in NAD 47/89 and suggest that LSP1 is distinct from other known actin binding proteins in its effect on F-actin network structure.  相似文献   
1000.
Mammography remains the most practical and reliable procedure for routine breast cancer screening. It also plays an important role, along with physical examination, in evaluation of symptoms of breast disease. Among the complementary imaging techniques, breast ultrasound is the most valuable. It helps differentiate cysts from solid lesions and assists in intervention. When used in combination, clinical breast examination and mammography and, if appropriate, ultrasound, offer the best opportunity for the evaluation of the breast in symptomatic and asymptomatic women.  相似文献   
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