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71.
72.
Mononuclear phagocytes appear to synthesize kynurenine-like products from the oxidation of biologically active indole compounds including melatonin, catalyzed by interferon (IFN)-gamma-inducible enzyme indoleamine 2,3-dioxygenase (IDO). Concanavalin A (Con A) is a plant lectin that induces interferon-gamma (IFN-gamma) production by T cells. In this study we investigated whether Con A-primed peritoneal macrophages are able to oxidize melatonin to N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK). The AFMK production was accompanied by chemiluminescence. It was found that Con A-primed but not resident macrophages produce AFMK. Surprisingly, Con A-primed macrophages from IFN-gamma-deficient mice were as effective as macrophages from IFN-gamma-sufficient mice in oxidizing melatonin. Moreover, addition of an inhibitor of IDO (1-methyltryptophan) did not affect melatonin oxidation. Con A-primed but not resident macrophages have a significant content of myeloperoxidase (MPO) and inhibition of MPO by azide completely blocked chemiluminescence and AFMK production. Thus, our findings provide evidence that melatonin oxidation by macrophages may occur through a mechanism dependent of MPO and independent of IFN-gamma and IDO activity.  相似文献   
73.
In vitro synthesis of the major lens membrane protein.   总被引:7,自引:0,他引:7       下载免费PDF全文
The biosynthetic activity of a polyribosomal fraction isolated from the lens fiber plasma membrane-cytoskeleton complex by DNase I treatment has been assayed. After translation of these polyribosomes in a reticulocyte cell-free system and analysis of the products by electrophoresis in sodium dodecyl sulfate gels, the preferential synthesis of a protein with an apparent molecular weight of 26,000 was observed. By means of immunochemical characterization we showed that this protein, which seems not to be synthesized by "free" polyribosomes, is identical with the major intrinsic plasma membrane protein MP26 of lens fibers. Upon storage, the molecular weight of the newly synthesized protein decreases to about 22,000, a phenomenon that has previously been observed for MP26 in isolated plasma membranes and that may be caused by the presence of a specific proteolytic cleaving site in the protein.  相似文献   
74.
Numerous medical sequelae associated with illicit drug use have been reported. Nevertheless, there has been scarce documentation of the effects of these drugs on the eyes. Drug-induced ocular symptoms include decreased visual acuity, disturbances in perception, and even flashbacks. Methamphetamine (METH) is a highly addictive drug whose abuse has spread worldwide during the past two decades. METH abuse is associated with many adverse psychiatric and medical consequences including strokes and psychosis. METH-induced ophthalmic complications are rarely discussed but include retinal vasculitis, episcleritis, panophthalmitis, endophthalmitis, scleritis, retinopathy, corneal ulceration, and transient visual losses. Because the drug has shown a marked increase in the prevalence of its use amongst pregnant women, there has also been an increase of drug-induced complications in fetuses and newborn babies. These complications need to be further detailed and studied. Herein, the authors report on the ocular complications associated with METH abuse. They also discuss some potential mechanisms for the toxic effects of the drug on that system.  相似文献   
75.
76.
Human prostate-specific antigen (hPSA) is found in serum and semen in a variety of forms, is form-free and complex, and has clinical importance to prostate cancer diagnosis. Here, a simple procedure is described for the efficient purification of hPSA from seminal plasma. The semen was clarified by centrifugation, and the isolation of PSA was carried out by immunoaffinity chromatography using the monoclonal antibody anti total PSA CB-PSA.4. The recuperation of PSA from seminal plasma by this procedure was 66.4%, and a purification factor of 65.8 was reached. The specificity activity obtained was 0.79 mg PSA/mg protein, and the preparation appeared homogeneous by SDS-PAGE and immunoelectrophoresis. A molecular weight of preparation was 30.46 kDa by SDS-PAGE, similar to the commercial PSA. These results indicate that immunoaffinity purification of PSA by means of this monoclonal antibody is a simple one-step procedure for the production of biologically active, highly purified human PSA.  相似文献   
77.
PspA is one of the most well studied pneumococcal proteins and a promising candidate for a future protein-based anti-pneumococcal vaccine. Nevertheless, its structural and serological variability suggests the inclusion of more than one PspA molecule in order to broaden protection. Since different PspAs exhibit variable levels of cross-reactivity, the selection of the protein combination with the highest coverage potential is an essential step for PspA-based vaccine development. This work investigated the level of cross-reactivity within family 1 PspAs, and established a complement based antibody mediated opsonophagocytic assay for measuring the level of cross-protection. Among a panel of ten family 1 PspA molecules, two of them, one belonging to clade 1 and another from clade 2, induced antibodies capable of enhancing complement deposition and mediating the phagocytic killing by mouse peritoneal macrophages of all pneumococci bearing PspA family 1 strains tested, regardless of their serotype. Therefore, we suggest the inclusion of either one in a PspA-based vaccine, as a representative of family 1. Furthermore, our results suggest that opsonophagocytosis by mouse peritoneal cells can be an efficient means of evaluating the induction of protective immune responses in mice across a large number of strains.  相似文献   
78.
We evaluated a new portable monitor (AvoSure PT PRO, Menarini Diagnostics, Firenze, Italy) developed to test the prothrombin time in capillary blood and plasma by comparing it with the standard laboratory determination. We studied 62 patients receiving acenocoumarol therapy. The international normalized ratio (INR) in capillary blood was analyzed by 2 methods: AvoSure PT PRO and Thrombotrack Nycomed Analyzer (Axis-Shield, Dundee, Scotland). Parallel studies were performed in plasma samples by a reference method using the Behring Coagulation Timer (Behring Diagnostics, Marburg, Germany). Plasma samples also were tested with the AvoSure PT PRO. Correlation was good for INR values for capillary blood and plasma samples by AvoSure PT PRO and our reference method (R2 = 0.8596) and for capillary blood samples tested by the AvoSure PT PRO and Thrombotrack Nycomed Analyzer (R2 = 0.8875). The correlation for INR in capillary blood and plasma samples by AvoSure PT PRO was 0.6939 (P < .0004). Capillary blood determinations are rapid and effective for monitoring oral anticoagulation therapy and have a high correlation to plasma determinations. AvoSure PT PRO is accurate for controlling INR in plasma and capillary blood samples, may be used in outpatient clinics, and has advantages over previous portable monitors.  相似文献   
79.
Temporal integration in an anuran auditory nerve   总被引:1,自引:0,他引:1  
We determined temporal integration in individual auditory nerve fibers of the arboreal frog, Eleutherodactylus coqui by measuring the change in rate threshold to tonal stimulation for tone burst durations from 20 to 450 ms. Temporal integration was quantified in two ways: (1) we calculated the temporal integration time constant of the fiber (tau), and (2) we calculated the shift in threshold per decade increment of the tone stimulus (dB/decade). In some cases, the procedure was repeated using a continuous, broadband noise masker (20-50 dB/Hz). Our results indicate that low frequency fibers (CF less than 0.50 kHz) have the longest mean integration time (274 ms), mid-frequency fibers (0.50 to 1.30 kHz) have the shortest mean integration time (183 ms) and high frequency fibers (CF greater than 1.3 kHz) have an intermediate mean integration time (235 ms). Continuous noise increased the integration times of some, but not all fibers, and caused some fibers which did not display temporal integration to do so. We investigated the possibility that these changes may be caused by a decrease in the slope of the rate-intensity function (measured between +5 and +15 dB re threshold) with the addition of the continuous noise masker. The slope of the rate-intensity function decreased (from 73 spikes/s/dB to 49 spikes/s/dB) with the addition of the continuous noise for those fibers (N = 28) that showed an increase in temporal integration with the addition of noise. However, the slopes of the rate-intensity functions also decreased by 30% for those fibers (N = 8) that did not show increasing temporal integration.  相似文献   
80.
BACKGROUND: The aim of this study was to evaluate the predictability of the free connective tissue graft in prosthetically treated patients needing gingival augmentation. The following outcome variables were studied 1) dimensional changes of free connective gingival grafts; 2) color blending with adjacent tissues; and 3) periodontal and marginal health status, when compared to a non-surgical control group. METHODS: Two groups of patients without periodontitis were investigated. The test group (group A) consisted of 16 patients. The inclusion criteria for surgical correction were: 1) at least 1 site lacking (<1 mm) keratinized tissue and/or lacking vestibular depth; 2) insufficient plaque control; and 3) the selected site was scheduled to undergo or had already received a fixed prosthetic restoration. The control group (group B) included 14 patients with the same inclusion criteria, but declining to undergo surgery. Group A patients were treated with a free connective tissue graft to augment the keratinized tissue at the selected sites. The size of the graft was recorded at baseline (surgical intervention) and the width of keratinized tissue was measured at 1, 4, 26, and 52 weeks. Gingival inflammation and plaque accumulation were assessed at baseline and 52 weeks in both groups. Probing depth and clinical attachment levels were recorded at baseline and 26 and 52 weeks in both groups. Evaluation of the esthetic results was carried out at the end of the study. All patients in both groups received oral hygiene instructions and supragingival plaque and calculus removal before and at the end of the investigation. RESULTS: In group A, the results showed a mean amount of keratinized tissue of 5.81 +/- 1.42 mm at 26 weeks and 5.25 +/- 1.34 mm at 52 weeks. Mean shrinkage of the graft was 10.2% (P = 0.001) at 1 week, 28.4% (P = 0.0004) at 4 weeks, 37.2% (P = 0.0004) at 26 weeks, and 43.25% (P = 0.0004) at 52 weeks. All the dimensional changes were statistically significant, when compared to baseline. Evaluation of color blending with the surrounding gingiva demonstrated an "excellent result" at 52 weeks with an 87.5% agreement among the three masked examiners. In the test group, the periodontal indices improved or remained stable; in the control group, there was a minor improvement of the indices, with three patients showing a worse gingival inflammation score and two a worse plaque score. CONCLUSION: Although these results are not conclusive, mostly due to a lack of a large enough sample population, the statistically significant results shown in this investigation tend to support the use of gingival augmentation procedures in prosthetic patients with insufficient keratinized gingiva and/or shallow or absent vestibules, when they cannot demonstrate adequate plaque control.  相似文献   
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