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81.
82.
A multidetector computed tomography (MDCT) was installed in our department. Referral rates, examination protocols and detection rates of abnormal findings in CT examinations for cervical spine trauma 6 months before and 6 months after MDCT installation were compared to look for changes in practice. Retrospective analysis of all CT cervical spine examinations in patients with multiple trauma over two contiguous 6-month periods: from July 2003 to December 2003 (helical CT) and from January 2004 to June 2004 (MDCT). Variables recorded were number of CT examinations performed, scan plane coverage and traumatic abnormalities detected. Phantom dosimetry measurements for cervical spine examination in both helical CT and MDCT were compared. One hundred and fifty four patients underwent cervical spine CT during these periods. Helical CT period: of 91 patients undergoing CT cervical spine examination for trauma, 65 (71%) were complete cervical examinations and 26 (29%) were level-specific examinations. Eight patients (9%) had cervical spine fracture, six of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 24.76, 1.86 and 0.21 mGy, respectively, for complete cervical spine examinations. MDCT period: of 63 patients who underwent CT cervical spine examination for trauma, 61 (97%) were complete examinations and 2 (3%) were level-specific examinations. Six patients (11%) had cervical spine fracture, three of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 75.8, 9.7 and 0.7 mGy, respectively, for complete cervical spine examinations, which were notably higher than those for helical CT. After installation of MDCT, clinical requests for complete examination of the cervical spine following trauma increased. This changing trend resulted in a significantly higher radiation dose to thyroid, lens and breast. 相似文献
83.
LainPM LoKW YuMY WongWS 《疑难病杂志》2005,4(1):39-39
患者,女性,54岁,中国籍,因急性左下肢水肿就诊。既往有子宫肌瘤史2年。腹部及盆腔凹显示左髂总静脉血栓及子宫左下部肌瘤(直径6cm)。考虑静脉血栓系肌瘤压迫髂静脉所致,予抗凝治疗,为缩小子宫体积以减轻其对髂静脉的压力,皮下注射促性腺激素释放激素类似物(GnRHa)3个月。患者对GnRHa冶疗无不良反应,治疗后闭经。4月后复查腹部及盆腔CT显示子宫明显缩小, 相似文献
84.
Tissue distribution and macromolecular binding of extremely low doses of [14C]-benzene in B6C3F1 mice 总被引:1,自引:0,他引:1
The tissue distribution and macromolecular binding of benzene was studied
over a dose range spanning nine-orders of magnitude to determine the nature
of the dose-response and to establish benzene's internal dosimetry at doses
encompassing human environmental exposures. [14C]-Benzene was administered
to B6C3F1 male mice at doses ranging between 700 pg/kg and 500 mg/kg body
wt. Tissues, DNA and protein were analyzed for [14C]-benzene content
between 0 and 48 h post-exposure (625 Ng/kg and 5 microg/kg dose) by
accelerator mass spectrometry (AMS). [14C]-Benzene levels were highest in
the liver and peaked within 0.5 h of exposure. Liver DNA adduct levels
peaked at 0.5 h, in contrast to bone marrow DNA adduct levels, which peaked
at 12-24 h. Dose- response assessments at 1 h showed that adducts and
tissue available doses increased linearly with administered dose up to
doses of 16 mg/kg body wt. Tissue available doses and liver protein adducts
plateau above the 16 mg/kg dose. Furthermore, a larger percentage of the
available dose in bone marrow bound to DNA relative to liver. Protein
adduct levels were 9- to 43-fold greater than DNA adduct levels. These data
show that benzene is bioavailable at human-relevant doses and that DNA and
protein adduct formation is linear with dose over a dose range spanning
eight orders of magnitude. Finally, these data show that the dose of
bioactive metabolites is greater to the bone marrow than the liver and
suggests that protein adducts may contribute to benzene's hematoxicity.
相似文献
85.
YL Lau LCK Low R Yung KW Ng CW Leung WH Lee A Ho SJ Oppenheimer Hong Kong Hib Study Group 《Acta paediatrica (Oslo, Norway : 1992)》1995,84(2):173-176
A 5-year territory-wide retrospective survey of invasive Haemophilus influenzae type b diseases was conducted in Hong Kong. Between 1986 and 1990, 57 cases (28 male) were recorded in children less than 12 years old (37 cases of meningitis, 9 of septicaemia and 11 of bacteraemic pneumonia). The annual incidence for children less than 5 years old was 2.7 per 105 (95% confidence interval (CI) 2.0–3.5). Of the 57 cases, 39 were Chinese and 18 non-Chinese (7 Vietnamese refugees, 6 Caucasians, 5 others). The annual incidence in Vietnamese refugees less than 5 years old was 42.7 per 105 (95% CI 17.2–87.9), giving a relative risk of 18.5 (95% CI 8.3–41.0). Chinese patients (68%) were under-represented as Chinese accounted for at least 94% of the population. Moreover, 14 of the 39 Chinese patients had pre-existing medical problems, compared with only 1 of the 18 non-Chinese patients (p = 0.022). 相似文献
86.
KW Bell RC Heng J Atallah I Chaitowitz 《Journal of Medical Imaging and Radiation Oncology》2006,50(4):377-380
The vastly improved scanning speed and z‐axis resolution afforded by multi‐detector technology has allowed CT to refine its traditional roles and to explore many new applications in imaging. We present a case report of a patient with renal failure and an ischaemic leg, which illustrates a useful new CT vascular imaging application. By carrying out 16‐channel multi‐detector row CT angiography through a sheath introduced into the common femoral artery, we obtained a high‐quality angiographic image of the affected leg, using only 30 mL of iodinated contrast material. The examination definitively showed the number, distribution and patency of the tibial run‐off arteries, with significant influence on the patient‘s subsequent clinical management. This simple and relatively minimally invasive technique is useful in peripheral vascular imaging, when conventional CT angiography using a large volume of i.v. contrast and MR angiography are unsuitable or unavailable. 相似文献
87.
88.
Winnie CW Chu Bobby KW Ng Albert M Li Tsz-ping Lam Wynnie WM Lam Jack CY Cheng 《Journal of orthopaedic surgery and research》2007,2(1):20-7
Background
Restrictive impairment is the commonest reported pulmonary deficit in AIS, which improves following surgical operation. However, exact mechanism of how improvement is brought about is unknown. Dynamic fast breath-hold (BH)-MR imaging is a recent advance which provides direct quantitative visual assessment of pulmonary function. By using above technique, change in lung volume, chest wall and diaphragmatic motion in AIS patients before and six months after posterior spinal fusion surgery were measured. 相似文献89.
NJ Hardcastle†§ AJ Tunbridge‡ KW Shum† DH Dockrell‡§ ST Green‡ 《Journal of the European Academy of Dermatology and Venereology》2005,19(5):631-633
We present a case where alopecia occurred with severe seborrhoeic dermatitis associated with the commencement of combination antiretroviral therapy for acute retroviral syndrome. We postulate that the eruption could represent a novel manifestation in association with immunological response to antiretroviral therapy. 相似文献
90.
Hepatoma, arterioportal shunting, and hyperkinetic portal hypertension: therapeutic embolization 总被引:8,自引:0,他引:8
Four patients with hepatocellular carcinoma, shunting of blood from the hepatic artery to the portal vein, and hyperkinetic portal hypertension were treated by transcatheter embolization of the hepatic artery. In three acutely bleeding patients variceal hemorrhage was controlled by the embolization. Following embolization hepatofugal portal venous flow became hepatopetal in all four patients. No serious complications were encountered. When hepatoma is complicated by arterioportal shunting and hyperkinetic portal hypertension, occlusion of the fistula by transcatheter embolotherapy can reduce the portal pressure. 相似文献