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81.
A comparison of six cypovirus isolates by cross-hybridisation of their dsRNA genome segments 总被引:5,自引:0,他引:5
Summary. Genetic relationships between the genome segments of six cypovirus (CPV) isolates were analysed by RNA cross-hybridisation.
These included three type 1 viruses and single isolates of types 2, 5 and 12, which collectively are identical to those previously
compared by serology and electrophoresis [Mertens et al. (1989), J Gen Virol 70: 173–185]. Since only genome segment 10 of
three cypovirus types and segments 8 and 9 of a single virus strain (of type 1) have currently been sequenced, this initial
study provides some additional information on sequence variation / similarity in each of the ten genome segments. The RNA
of the type 1 viruses showed high levels of cross-hybridisation. Significant but much lower levels of cross-hybridisation
were detected between type 1 and the related type 12 CPV. However, only very low levels of cross-hybridisation were detected
between the other pairs of viruses. Apart from evidence of a slightly higher level of sequence similarity between the largest
segments, the RNA sequence appeared to vary uniformly across the whole genome. There was no evidence for any type specific
RNA sequences restricted to individual genome segment(s). The sequence variation, reflected in the levels of RNA sequence
similarity and cross hybridisation, correlates well with serological data, showing large differences between CPV types and
supports the continued use of electropherotype as one of the ‘species parameters’ for the classification of cypoviruses.
Received April 30, 1998 Accepted August 14, 1998 相似文献
82.
Evaluation of the Digene Hybrid Capture II Assay with the Rapid Capture System for detection of Chlamydia trachomatis and Neisseria gonorrhoeae
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Van Der Pol B Williams JA Smith NJ Batteiger BE Cullen AP Erdman H Edens T Davis K Salim-Hammad H Chou VW Scearce L Blutman J Payne WJ 《Journal of clinical microbiology》2002,40(10):3558-3564
Screening for chlamydial and gonococcal infection has been strongly recommended for all sexually active women under the age of 26. Advances in the ability to detect infection by nucleic acid detection techniques have improved access to screening methods in routine clinical practices. To meet the increasing demand for testing, a high-throughput system is desirable. We evaluated the performance of the Hybrid Capture 2 CT/GC (HC2) assay with the Digene Rapid Capture System (HC2-RCS). The results of HC2-RCS for endocervical samples from 330 women were compared to those of culture and the COBAS Amplicor PCR. For detection of chlamydial infection, HC2-RCS had a sensitivity and a specificity similar to those of PCR (P > 0.5) and an improved sensitivity compared to that of culture (P = 0.007). For identification of gonococcal infections, all assays performed similarly (P > 0.5). The performance of HC2-RCS was also compared to that of the manual HC2 format (HC2-M) with these samples and with 911 endocervical samples collected previously. The performance of HC2-RCS was equivalent to that of HC2-M; the overall concordance rates for the detection of chlamydia and gonorrhea were 99.7% (kappa = 0.97) and 99.8% (kappa = 0.97), respectively. When the HC2 assay was performed with a semiautomated system application designed for high throughput, it demonstrated high sensitivity and a high specificity for detection of both Chlamydia trachomatis and Neisseria gonorrhoeae. 相似文献
83.
84.
Preliminary observations on polar body extrusion and pronuclear formation in human oocytes using time-lapse video cinematography 总被引:10,自引:17,他引:10
Payne D; Flaherty SP; Barry MF; Matthews CD 《Human reproduction (Oxford, England)》1997,12(3):532-541
In this study, we have used time-lapse video cinematography to study
fertilization in 50 human oocytes that had undergone intracytoplasmic sperm
injection (ICSI). Time-lapse recording commenced shortly after ICSI and
proceeded for 17-20 h. Oocytes were cultured in an environmental chamber
which was maintained under standard culture conditions. Overall, 38 oocytes
(76%) were fertilized normally, and the fertilization rate and embryo
quality were not significantly different from 487 sibling oocytes cultured
in a conventional incubator. Normal fertilization followed a defined course
of events, although the timing of these events varied markedly between
oocytes. In 35 of the 38 fertilized oocytes (92%), there were circular
waves of granulation within the ooplasm which had a periodicity of 20-53
min. The sperm head decondensed during this granulation phase. The second
polar body was then extruded, and this was followed by the central
formation of the male pronucleus. The female pronucleus formed in the
cytoplasm adjacent to the second polar body at the same time as, or
slightly after, the male pronucleus, and was subsequently drawn towards the
male pronucleus until the two abutted. Both pronuclei then increased in
size, the nucleoli moved around within the pronuclei and some nucleoli
coalesced. During pronuclear growth, the organelles contracted from the
cortex towards the centre of the oocyte, leaving a clear cortical zone. The
oocyte decreased in diameter from 112 to 106 microm (P < 0.0001) during
the course of the observation period. The female pronucleus was
significantly smaller in diameter than the male pronucleus (24.1 and 22.4
microm respectively, P = 0.008) and contained fewer nucleoli (4.2 and 7.0
respectively, P < 0.0001). After time-lapse recording, oocytes were
cultured for 48 h prior to embryo transfer or cryopreservation. Embryo
quality was related to fertilization events and periodicity of the
cytoplasmic wave, and it was found that good quality embryos arose from
oocytes that had more uniform timing from injection to pronuclear abuttal
and tended to have a longer cytoplasmic wave. In conclusion, we have shown
that time-lapse video cinematography is an excellent tool for studying
fertilization and early embryo development, and have demonstrated that
human fertilization comprises numerous complex dynamic events.
相似文献
85.
Campbell JM Gilmore DP Russell D Growney CA Favor G Kennedy AK Davies RW Payne AP Stone TW 《Neuroscience》2000,100(1):45-52
The as/agu rat is a spontaneously occurring mutation which exhibits locomotor abnormalities, reduced tyrosine hydroxylase levels in the substantia nigra and lower extracellular levels of dopamine. The animal could represent a model of some human locomotor disorders. High-potassium medium evoked a 460% rise of dopamine levels in control rats but double this in mutants. Amphetamine increased extracellular dopamine by 710% in controls and 1480% in mutants. Clorgyline produced a small increase of dopamine levels in controls but an 1170% increase in mutants. The uptake inhibitor nomifensine increased dopamine levels by 910% in controls but only 270% in mutants. After treatment with benserazide plus L-DOPA, an acute injection of L-DOPA evoked a release of dopamine which was twice as large in the as/agu rats compared with controls. The results show reduced extracellular dopamine in as/agu rats when the locomotor disorder is apparent, but there has been little loss of tyrosine hydroxylase. The responses to drugs are qualitatively different from those obtained using 6-hydroxydopamine.Overall, the effects of compounds affecting aminergic neurons suggest that one possible mechanism for the neuronal abnormality in as/agu rats is a defective regulation of dopamine release from striatal terminals. 相似文献
86.
C R Payne J W Hadfield P G Stovin V Barker B E Heard J E Stark 《Journal of clinical pathology》1981,34(7):773-778
The accuracy of diagnosis in 656 patients with the four common histopathological types of primary lung cancer has been assessed by comparing the cell type diagnosis made on cytological and histological investigation with that determined by examination of the surgically resected or necroscopy specimen. The accuracy of diagnosis achieved by cytological examination of sputum and bronchial aspirate, and by bronchial biopsy histology was over 85%. The least accurate diagnostic procedure was percutaneous needle biopsy (62%). Squamous and small cell tumours were accurately diagnosed by all four investigations but errors were made in the diagnosis of large cell and adenocarcinomas. Nearly half the number of patients (43%) with large cell carcinoma were later reclassified as having squamous carcinoma and of the patients with adenocarcinoma 32% had been predicted to be squamous and 18% large cell carcinoma. We consider such quality control of pretreatment diagnosis mandatory in management of individual patients and before enrollment in clinical trials. 相似文献
87.
88.
Evaluation of the single radial haemolysis (SRH) technique for rubella antibody measurement.
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S M Russell S R Benjamin M Briggs M Jenkins P P Mortimer S B Payne 《Journal of clinical pathology》1978,31(6):521-526
Sera from 1258 individuals have been tested by four laboratories for rubella antibody by both the haemagglutination-inhibition and single radial haemolysis techniques. There was good agreement between the results obtained by the two methods. Although sheep red blood cells were used in the single radial haemolysis plates, no problems were encountered with sera from patients with infectious mononucleosis. The single haemolysis technique was found to be simple, convenient, and reliable, and suited to the rapid screening of large numbers of sera to assess susceptibility to rubella in the context of a vaccination campaign. However, since the technique does not detect anti-rubella IgM, it should not be used as the only test to investigate suspected recent infection. 相似文献
89.
Primary and secondary tumour and bone marrow trephine biopsies from 20 patients with carcinomas were stained for carcinoembryonic antigen by the three stage immunoperoxidase method. Six marrow biopsies contained tumour deposits, five of which were positive for carcinoembryonic antigen. A further five marrow biopsies contained single carcinoembryonic antigen positive cells of uncertain origin. Carcinoembryonic antigen staining may be a useful adjunct to conventional histology in the diagnosis of marrow metastases. 相似文献
90.
A three-phase evaluation of the Toa E-5000 Automated Hematology Analyzer was performed. The first phase consisted of evaluation of linearity, carryover, precisions, accuracy, sample stability, and effectiveness of the mixing and sampling mechanism. The second phase was comparison of erythroid and platelet parameters with results from a Coulter Counter Model S-Plus IV. The third phase consisted of comparison of the trimodal leukocyte differential count of the Toa E-5000 in 300 patients with four other differential methods. The first-phase studies showed excellent performance characteristics. Stability of samples at room temperature was good for a minimum of 12 hours, but storage for longer than 12 hours requires refrigeration to maintain stable values. The erythrocyte and platelet parameters showed good correlation with the Coulter S-Plus IV values except for the erythrocyte distribution width that is calculated differently. The third-phase studies are published elsewhere. 相似文献