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101.
BACKGROUND: Optical coherence tomography (OCT) is a noninvasive, noncontact transpupillary imaging technology that can image retinal structures in vive with a resolution of up to 10 microns. Anatomic layers within the retina can be differentiated and retinal thickness measured. The objective is to demonstrate clinical viability and useful interpretation of macular images derived from a commercially available OCT instrument. MEHODS: A Stratus OCT (Zeiss-Humphrey, Dublin, California) imaging system was used to evaluate several pathological presentations of the macula in selected patients. Conditions illustrated in this case series were macular holes, epiretinal membranes, macular edema, idiopathic central serous choroidopathy, detachments of pigment epithelium and sensory retina, choroidal neovascular membranes, and retinal vascular occlusions. CONCLUSIONS: Acquired OCT images achieved structural information regarding anatomical characteristics of the conditions scanned. A cross-sectional resolution of 10 microns was accomplished, which is 10 times greater than current ultrasound. OCT provides important information that may be critical in the diagnosis and management of some ocular conditions. Its high-resolution scans may contribute to the better understanding of disease pathogenesis, as well as assistance in or confirmation of a diagnosis. This imaging technology provides important information beyond what can be seen on clinical examination, and offers a useful adjunct to other diagnostic imaging tools such as fundus photography, fluorescein angiography, and indocyanine green angiography. 相似文献
102.
The porous coated anatomic total hip replacement. A ten to fourteen-year follow-up study of a cementless total hip arthroplasty 总被引:8,自引:0,他引:8
Kawamura H Dunbar MJ Murray P Bourne RB Rorabeck CH 《The Journal of bone and joint surgery. American volume》2001,(9):1333-1338
BACKGROUND: We previously reported our two and five-year results of arthroplasty with the Porous Coated Anatomic total hip prosthesis. We now report on the performance of this prosthesis at ten to fourteen years. METHODS: The results of 311 total hip replacements in which a Porous Coated Anatomic prosthesis was inserted without cement in 279 patients were analyzed prospectively. The average age of the patients at the time of the replacement was sixty--one years (range, twenty to eighty-one years). Sixty-four patients (seventy-six hips) died postoperatively. Forty-five patients (forty-seven hips) were lost to follow-up, and four were excluded because of their medical condition. One hundred and sixty-eight patients (187 hips) were followed for ten to fourteen years (average, twelve years). Seventeen of those patients (seventeen hips) had a revision. RESULTS: The overall survival rate (with any revision as the end point) was 90.0% +/- 5.4% at fourteen years, with an average Harris hip score of 85 +/- 14 points. The prevalence of thigh pain was 36% (fifty-six of 157) in the late period (more than ten years postoperatively). Radiographs showed stable fixation, with bone ingrowth, of 83% (130) of the 156 acetabular components and 88% (137) of the 156 femoral components at the latest follow-up evaluation. Men had a significantly higher rate of femoral osteolysis than did women (p < 0.001). The rates of acetabular and femoral osteolysis associated with 32-mm femoral heads (49% [twenty-three] of forty-seven and 70% [thirty-three] of forty-seven, respectively) were significantly higher (p < 0.01) than those associated with 26-mm heads (26% [twenty-eight] of 109 and 30% [thirty-three] of 109, respectively). Despite this, revision (removal or exchange of components) was not directly related to head size; instead, it was related to polyethylene thickness. CONCLUSIONS: There have been persistent problems with the Porous Coated Anatomic hip system, including thigh pain and an increasing prevalence of osteolysis with time. Revision because of aseptic loosening was related more to the thickness of the polyethylene liner than to the size of the femoral head. Femoral heads with a 32-mm diameter did not increase the risk for revision provided that an adequate thickness of polyethylene had been used. 相似文献
103.
104.
Referred phantom sensations and cortical reorganization after spinal cord injury in humans 下载免费PDF全文
Moore CI Stern CE Dunbar C Kostyk SK Gehi A Corkin S 《Proceedings of the National Academy of Sciences of the United States of America》2000,97(26):14703-14708
To test the hypothesis that cortical remapping supports phantom sensations, we examined referred phantom sensations and cortical activation in humans after spinal-cord injury (SCI) at the thoracic level (T3-T12). Of 12 SCI subjects, 9 reported phantom sensations, and 2 reported referred phantom sensations. In both of these subjects, referred phantom sensations were evoked by contact in reference zones (RZ) that were not adjacent in the periphery and were not predicted to be adjacent in the postcentral gyrus (PoCG), suggesting that representations separated by centimeters of cortical space were simultaneously engaged. This finding was supported by functional MRI (fMRI). In a subject with a T6-level complete SCI, contact in RZ on the left or right forearm projected referred phantom sensations to the ipsilateral chest. During fMRI, contact in either forearm RZ evoked activity in the central PoCG (the position of the forearm representation) and the medial PoCG (the position of the chest representation) with >/=1.6 cm of nonresponsive cortex intervening. In contrast, stimulation in non-RZ forearm and palm regions in this subject and in lesion-matched SCI subjects evoked central but not medial PoCG activation. Our findings support a relation between PoCG activation and the percept of referred phantom sensations. These results, however, present an alternative to somatotopic cortical reorganization, namely, cortical plasticity expressed in coactivation of nonadjacent representations. The observed pattern suggests that somatotopic subcortical remapping, projected to the cortex, can support perceptual and cortical reorganization after deafferentation in humans. 相似文献
105.
Loss of tumor-promoting activity of unleaded gasoline in N- nitrosodiethylamine-initiated ovariectomized B6C3F1 mouse liver 总被引:1,自引:0,他引:1
Unleaded gasoline (UG) vapor (2056 ppm) increased the incidence of liver
tumors in a chronic bioassay and exhibited tumor-promoting activity in
N-nitrosodiethylamine (DEN)-initiated female mouse liver. Estrogen
inhibited mouse liver tumor development and the hepatocarcinogenic and
tumor-promoting dose of UG produced uterine changes suggestive of estrogen
antagonism. To directly test the hypothesis that UG-induced tumor-promoting
ability is secondary to its interaction with the mouse liver tumor
inhibitor, estrogen, we compared the tumor-promoting ability of UG in
ovariectomized (Ovex) mice with the hepatic tumor-promoting ability of UG
in intact mice. Ovaries were surgically removed at 4 weeks of age. Exposure
to wholly vaporized UG (2018 ppm) under bioassay and tumor-promoting
conditions began at 8 weeks of age. After 4 months of exposure, UG
increased relative liver weight and hepatic microsomal cytochrome P450
pentoxyresourfin-O- dealkylase and ethoxyresorufin-O-deethylase activity to
a similar extent in intact and Ovex mice. Non-focal hepatocyte
proliferation, as measured by the incorporation of bromo-deoxyuridine, was
not changed by UG exposure and was similar in all treatment groups. After 4
months of exposure to DEN-initiated mice, UG significantly increased the
volume fraction of liver occupied by foci (three-fold) as compared to
control intact mice. As expected, volume of foci was elevated in
DEN/Ovex/control mice as compared to DEN/intact/control mice. In DEN/Ovex
mice UG did not significantly increase the focal volume fraction. Thus, the
tumor promoting activity of UG, as demonstrated by increased volume
fraction of liver occupied by hepatic foci in intact mice, is greatly
attenuated in Ovex mice. The volume fraction data in Ovex mice support the
hypothesis that the tumor promoting activity of UG is dependent upon the
interaction of UG with ovarian hormones. These data also indicate that
hepatic microsomal cytochrome P450 PROD and EROD induction, hepatomegaly
and non-focal hepatic LI are not specific markers of hepatic tumor
promoting activity of UG.
相似文献
106.
Perkins SN; Hursting SD; Haines DC; James SJ; Miller BJ; Phang JM 《Carcinogenesis》1997,18(5):989-994
Transgenic mice with both alleles of the p53 tumor suppressor gene product
'knocked out' by gene targeting are susceptible to early development of
tumors, chiefly lymphomas and sarcomas. Compared with the control group,
administration of dehydroepiandrosterone (DHEA) at 0.3% of the diet to male
p53-deficient mice extended their lifespan by delaying death due to
neoplasms (from 105 to 166 days on study, P = 0.002), primarily by
suppressing lymphoblastic lymphoma (from 45 to 6% of neoplastic deaths, P =
0.010). Treatment with a synthetic DHEA analog,
16alpha-fluoro-5-androsten-17-one (compound 8354), at 0.15% of the diet
also increased lifespan, to 140 days for mice that developed tumors (P =
0.037). The effects of these steroids on lifespan and tumor development did
not appear to be strongly related to inhibition of food consumption and
weight gain, in that a group pair-fed with control diet to the reduced food
consumption of the DHEA-treated group developed and died of the same types
of neoplasms at the same rate as the controls fed ad libitum. The
chemopreventive effect of these steroids has been proposed to be due to
suppression of DNA synthesis by inhibition of glucose 6-phosphate
dehydrogenase, the rate-limiting enzyme of the pentose phosphate pathway.
Although DHEA and its analog are strong non- competitive inhibitors of this
enzyme in vitro, treatment with DHEA did not deplete cellular nucleotide
pools in the liver, as would have been predicted. The chemopreventive
effect of DHEA in this model may be due to steroid-induced thymic atrophy
and suppression of T cell lymphoma, permitting these mice to survive long
enough to develop tumors with longer latency.
相似文献
107.
Wu DC; Liu JM; Chen YM; Yang S; Liu SM; Chen LT; Whang-Peng J 《Japanese journal of clinical oncology》1997,27(2):115-118
Hemolytic uremic syndrome spontaneously arises in a few patients with
advanced cancer, but it is more commonly related to the use of certain
chemotherapeutic agents. Mitomycin-C is, etiologically, the most common
causative agent inducing hemolytic uremic syndrome, in a dose dependent
manner. We report this syndrome, attributable to mitomycin-C at a
cumulative dose of 40 mg/m2, in a gastric cancer patient. A 42-year-old
female with stage III gastric cancer underwent radical gastrectomy and was
given mitomycin-C at 10 mg/m2 intravenously every four weeks as adjuvant
therapy. Hemolytic uremic syndrome was diagnosed three months after the
last dose of mitomycin-C administration. The most prominent symptoms
included pallor, hypertension and anasarca, with laboratory evidence of
microangiopathic hemolytic anemia, azotemia and hyperkalemia. Her disease
was progressive, but fortunately stabilized after staphylococcus column A
dialysis. Her disease remained in remission for 24 months from the time of
diagnosis, and then relapsed in the form of peritoneal carcinomatosis with
partial intestinal obstruction.
相似文献
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