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Primary and revision total knee arthroplasty have become common orthopaedic procedures. The operating surgeon, at times, may be faced with a difficult surgical case due to soft tissue contractures or bone deformities. A review of multiple surgical techniques using soft tissue releases and osteotomies are presented including their potential complications. Although these techniques are aimed at the atypical operative case, the operating surgeon may utilize them for ‘routine’ exposures as well. Importance is focused on the functional integrity of the knee extensor mechanism. 相似文献
14.
Frequency-domain analysis of cerebral autoregulation from spontaneous fluctuations in arterial blood pressure 总被引:4,自引:0,他引:4
Dr. R. B. Panerai J. M. Rennie A. W. R. Kelsall D. H. Evans 《Medical & biological engineering & computing》1998,36(3):315-322
The dynamic relationship between spontaneous fluctuations of arterial blood pressure (ABP) and corresponding changes in crebral
blood flow velocity (CBFV) is studied in a population of 83 neonates. Static and dynamic methods are used to identify two
subgroups showing either normal (group A, n=23) or impaired (group B, n=21) cerebral autoregulation. An FFT algorithm is used
to estimate the coherence and transfer function between CBFV and ABP. The significance of the linear dependence between these
two variables in demonstrated by mean values of squared coherence >0.50 for both groups in the frequency range 0.02–0.50 Hz.
However, group A has significanlty smaller coherences than group B in the frequency ranges 0.02–0.10 Hz and 0.33–0.49 Hz.
The phase response of group A is also significantly more positive than that of group B, with slopes of 9.3±1.05 and 1.80±1.2
rad Hz−1, respectively. The amplitude frequency response is also significantly smaller for group A in relation to group B for the
frequency range 0.25–0.43 Hz. These results suggest that transfer function analysis may be able to identify different components
of cerebral autoregulation and also provide a deeper understanding of recent findings by other investigators. 相似文献
15.
CNS pattern of metabolic activity during tonic pain: evidence for modulation by beta-endorphin 总被引:1,自引:0,他引:1
Porro CA Cavazzuti M Baraldi P Giuliani D Panerai AE Corazza R 《The European journal of neuroscience》1999,11(3):874-888
CNS correlates of acute prolonged pain, and the effects of partial blockade of the central beta-endorphin system, were investigated by the quantitative 2-deoxyglucose technique in unanaesthetized, freely moving rats. Experiments were performed during the second, tonic phase of the behavioural response to a prolonged chemical noxious stimulus (s.c. injection of dilute formalin into a forepaw), or after minor tissue injury (s.c. saline injection). During formalin-induced pain, local glucose utilization rates in the CNS were bilaterally increased in the grey matter of the cervical spinal cord, in spinal white matter tracts and in several supraspinal structures, including portions of the medullary reticular formation, locus coeruleus, lateral parabrachial region, anterior pretectal nucleus, the medial, lateral and posterior thalamic regions, basal ganglia, and the parietal, cingulate, frontal, insular and orbital cortical areas. Pretreatment with anti-beta-endorphin antibodies, injected i.c.v., led to increased metabolism in the tegmental nuclei, locus coeruleus, hypothalamic and thalamic structures, putamen, nucleus accumbens, diagonal band nuclei and dentate gyrus, and in portions of the parietal, cingulate, insular, frontal and orbital cortex. In formalin-injected rats, pretreated with anti-beta-endorphin, behavioural changes indicative of hyperalgesia (increased licking response) were found, which were paralleled by a significant enhancement of functional activity in the anterior pretectal nucleus and in thalamo-cortical systems. A positive correlation was found between the duration of the licking response and metabolic activity of several forebrain regions. These results provide a map of the CNS pattern of metabolic activity during tonic somatic pain, and demonstrate a modulatory role for beta-endorphin in central networks that process somatosensory inputs. 相似文献
16.
Cerebrovascular response to dynamic changes in pCO2 总被引:4,自引:0,他引:4
Garnham J Panerai RB Naylor AR Evans DH 《Cerebrovascular diseases (Basel, Switzerland)》1999,9(3):146-151
Fifty-six subjects with carotid artery disease were assessed by measuring the cerebral blood flow velocity (CBFV) change in response to inhalation of 5% CO2 in air whilst continuously monitoring the blood pressure (BP). Coherent averaging of the data characterised differences in CBFV, BP, resistance area product and critical closing pressure during changes in end-tidal CO2 (ETCO2). The results primarily demonstrate that the augmentation of ETCO2 increases the CBFV and BP, causing a pressure autoregulatory response, and allows the processes of pressure autoregulation and cerebral vascular reserve to be differentiated. 相似文献
17.
Impact of education for physicians on patient outcomes 总被引:4,自引:0,他引:4
NM Clark M Gong MA Schork D Evans D Roloff M Hurwitz L Maiman RB Mellins 《Pediatrics》1998,101(5):831-836
18.
Hemoglobin and albumin adducts of benzene oxide among workers exposed to high levels of benzene 总被引:3,自引:0,他引:3
Yeowell-O'Connell K; Rothman N; Smith MT; Hayes RB; Li G; Waidyanatha S; Dosemeci M; Zhang L; Yin S; Titenko-Holland N; Rappaport SM 《Carcinogenesis》1998,19(9):1565-1571
Benzene oxide (BO) reacts with cysteinyl residues in hemoglobin (Hb) and
albumin (Alb) to form protein adducts (BO-Hb and BO-Alb), which are
presumed to be specific biomarkers of exposure to benzene. We analyzed
BO-Hb in 43 exposed workers and 42 unexposed controls, and BO-Alb in a
subsample consisting of 19 workers and 19 controls from Shanghai, China, as
part of a larger cross-sectional study of benzene biomarkers. The adducts
were analyzed by gas chromatography-mass spectrometry following reaction of
the protein with trifluoroacetic anhydride and methanesulfonic acid. When
subjects were divided into controls (n = 42) and workers exposed to < or
=31 (n = 21) and >31 p.p.m. (n = 22) benzene, median BO-Hb levels were
32.0, 46.7 and 129 pmol/g globin, respectively (correlation with exposure:
Spearman r = 0.67, P < 0.0001). To our knowledge, these results
represent the first observation in humans that BO-Hb levels are
significantly correlated with benzene exposure. Median BO-Alb levels in
these 3 groups were 103 (n = 19), 351 (n = 7) and 2010 (n = 12) pmol/g Alb,
respectively, also reflecting a significant correlation with exposure
(Spearman r = 0.90, P < 0.0001). The blood dose of BO predicted from
both Hb and Alb adducts was very similar. These results clearly affirm the
use of both Hb and Alb adducts of BO as biomarkers of exposure to high
levels of benzene. As part of our investigation of the background levels of
BO-Hb and BO-Alb found in unexposed persons, we analyzed recombinant human
Hb and Alb for BO adducts. Significant levels of both BO-Hb (19.7 pmol/g)
and BO-Alb (41.9 pmol/g) were detected, suggesting that portions of the
observed background adducts reflect an artifact of the assay, while other
portions are indicative of either unknown exposures or endogenous
production of adducts.
相似文献
19.
Increased aneusomy and long arm deletion of chromosomes 5 and 7 in the lymphocytes of Chinese workers exposed to benzene 总被引:4,自引:1,他引:4
Zhang L; Rothman N; Wang Y; Hayes RB; Li G; Dosemeci M; Yin S; Kolachana P; Titenko-Holland N; Smith MT 《Carcinogenesis》1998,19(11):1955-1961
Two of the most common cytogenetic changes in therapy- and chemical-
related leukemia are the loss and long (q) arm deletion of chromosomes 5
and 7. The detection of these aberrations in lymphocytes of individuals
exposed to potential leukemogens may serve as useful biomarkers of
increased leukemia risk. We have used a novel fluorescence in situ
hybridization (FISH) procedure to determine if specific aberrations in
chromosomes 1, 5 and 7 occur at an elevated rate in the blood cells of
workers exposed to benzene. Forty-three healthy workers exposed to a wide
range of benzene concentrations (median 31 p.p.m., 8 h time-weighted
average) and 44 unexposed controls from Shanghai were studied. Whole blood
was cultured and metaphase spreads were harvested at 72 h. Benzene exposure
was associated with increases in the rates of monosomy 5 and 7 but not
monosomy 1 (P < 0.001, P < 0.0001 and P = 0.94, respectively) and
with increases in trisomy and tetrasomy frequencies of all three
chromosomes. Long arm deletion of chromosomes 5 and 7 was increased in a
dose-dependent fashion (P = 0.014 and P < 0.0001) up to 3.5-fold in the
exposed workers. These results demonstrate that leukemia-specific changes
in chromosomes 5 and 7 can be detected by FISH in the peripheral blood of
otherwise healthy benzene-exposed workers. We suggest that aberrations in
chromosomes 5 and 7 may be useful biomarkers of early biological effect for
benzene exposure.
相似文献
20.
新生儿复苏培训项目十年回顾 总被引:5,自引:1,他引:5
每年约2000万新生儿出生的中国,鼓励一对夫妻只生一个孩子,随着国民经济迅速发展,生活水平不断提高,每一个新生儿的健康都受到家庭及社会的高度关注。1991年中国要儿死亡率为50.2‰,1998年降至33.3‰,地区性差别很大,贫困地区最高可达56‰,一些条件较好的城市低至7.5‰。围产医学界公认围产窒息为要儿患病及死亡的首要原因,如合并早产、严重肺、脑疾病等后果更为严重。 相似文献