全文获取类型
收费全文 | 1057篇 |
免费 | 56篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 70篇 |
妇产科学 | 8篇 |
基础医学 | 101篇 |
口腔科学 | 18篇 |
临床医学 | 163篇 |
内科学 | 241篇 |
皮肤病学 | 22篇 |
神经病学 | 35篇 |
特种医学 | 291篇 |
外科学 | 65篇 |
综合类 | 21篇 |
一般理论 | 1篇 |
预防医学 | 34篇 |
眼科学 | 2篇 |
药学 | 86篇 |
肿瘤学 | 35篇 |
出版年
2023年 | 3篇 |
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 27篇 |
2012年 | 22篇 |
2011年 | 9篇 |
2010年 | 32篇 |
2009年 | 43篇 |
2008年 | 24篇 |
2007年 | 70篇 |
2006年 | 12篇 |
2005年 | 25篇 |
2004年 | 25篇 |
2003年 | 20篇 |
2002年 | 14篇 |
2001年 | 22篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 66篇 |
1997年 | 73篇 |
1996年 | 52篇 |
1995年 | 65篇 |
1994年 | 38篇 |
1993年 | 36篇 |
1992年 | 20篇 |
1991年 | 25篇 |
1990年 | 18篇 |
1989年 | 36篇 |
1988年 | 37篇 |
1987年 | 27篇 |
1986年 | 27篇 |
1985年 | 49篇 |
1984年 | 22篇 |
1983年 | 17篇 |
1982年 | 26篇 |
1981年 | 14篇 |
1980年 | 24篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 15篇 |
1976年 | 15篇 |
1975年 | 9篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有1195条查询结果,搜索用时 31 毫秒
1.
2.
The simultaneous determination of cerebrospinal fluid and plasma adenosine deaminase activity as a diagnostic aid in tuberculous meningitis 总被引:1,自引:0,他引:1
P R Donald C Malan A van der Walt J F Schoeman 《Suid-Afrikaanse tydskrif vir geneeskunde》1986,69(8):505-507
The simultaneous determination of cerebrospinal fluid (CSF) and plasma adenosine deaminase (ADA) activity was evaluated as a diagnostic aid in tuberculous meningitis (TBM). CSF and plasma ADA activity were determined in four groups of patients: (i) a 'no meningitis' group of 174 children investigated for possible meningitis, but found to be uninfected; (ii) an aseptic meningitis group of 40 children; (iii) a bacterial meningitis group of 31 children; and (iv) a TBM group of 27 patients (24 children and 3 adults). CSF ADA alone was determined in a further 23 children with aseptic meningitis, 19 with bacterial meningitis and 13 children and 7 adults with TBM. Both the CSF/plasma ADA ratio and the absolute CSF ADA activity were raised in TBM (mean values 0,24 and 12,61 U/I respectively) and bacterial meningitis (mean values 0,59 and 15,43 U/I respectively), but not in the aseptic meningitis group (mean values 0,06 and 2,00 U/I) or the 'no meningitis' group (mean values 0,04 and 1,51 U/I). Both values will distinguish TBM from aseptic meningitis, but do not appear to hold any marked advantages over conventional CSF criteria in the diagnosis of TBM. 相似文献
3.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
4.
5.
D. Chemla P. Démolis M. Thyrault D. Annane Y. Lecarpentier and JF Giudicelli 《Fundamental & clinical pharmacology》1996,10(4):393-399
Summary— The influence of local resistance and cardiac performance on peripheral blood acceleration was investigated in 14 healthy male volunteers. Steady and pulsatile flow was studied in the brachial and in the common carotid arteries, ie, two territories that exhibit marked differences in resistive characteristics. Instantaneous blood velocity (V), mean blood velocity (Vm ) and artery diameter (D) were evaluated at rest by an ultrasonic range-gated pulsed Doppler flowmeter using a double transducer probe, thus allowing the calculation of mean blood flow (Q). Mean local resistance (R) was obtained by dividing the mean arterial pressure by Q. The peak value of the local acceleration of the blood was obtained by computer-assisted calculation of the first derivative of instantaneous blood velocity (Gmax = +dV/dtmax ). Peak aortic blood acceleration (GAo) was simultaneously measured from the suprasternal notch using a pulsed Doppler velocity meter. In the brachial and the common carotid arteries, Gmax was of a similar magnitude (551 ±30 and 555 ± 44 cm/s2 , respectively) despite major differences in the respective D, Vm , Q and R values. In neither artery was there a relationship between Gmax and either resting Q or R. At the brachial artery level, Gmax was positively related to GAo ( r = 0.79, P = 0.0008). At the common carotid artery level, there was a weak, although non significant relationship between Gmax and GAo ( P = 0.08). Our results indicate that the local acceleration of peripheral blood flow in the brachial artery is related rather to upstream central impulse than to downstream hemodynamics, and suggest some regional differences in the hemodynamic determinants of the local acceleration of peripheral blood flow. 相似文献
6.
In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population. 相似文献
7.
8.
Chronic exposure of humans to benzene (BZ), a myelotoxin, causes aplastic anemia and acute leukemia. The stromal macrophage that produces interleukin-1 (IL-1), a cytokine essential for hematopoiesis, is a target of BZ's toxicity. Monocyte dysfunction and decreased IL-1 production have been shown to be involved in aplastic anemia in humans. Hydroquinone (HQ), a toxic bone marrow (BM) metabolite of BZ, causes time- and concentration-dependent inhibition of processing of the 34-Kd pre-interleukin-1 alpha (IL-1 alpha) to the 17-Kd mature cytokine in murine P388D1 macrophages and BM stromal macrophages, as measured by Western immunoblots of cell lysate proteins using a polyclonal rabbit antimurine IL-1 alpha antibody. HQ over a 10-fold concentration range had no effect on the lipopolysaccharide (LPS)-induced production of pre- IL-1 alpha precursor or on cell viability or DNA and protein synthesis. Stromal macrophages obtained from the femoral BM of C57Bl/6 mice exposed to BZ (600 or 800 mg/kg body weight) for 2 days were incapable of processing the 34-Kd pre-IL-1 alpha to the mature 17-Kd cytokine when stimulated in culture with LPS. Stromal macrophages from mice coadministered BZ and indomethacin, a prostaglandin H synthase (PHS) inhibitor that has been shown to prevent BZ-induced myelotoxic and genotoxic effects in mice when coadministered with benzene were able to convert the pre-IL-1 alpha to mature cytokine. Administration of recombinant murine IL-1 alpha (rMuIL-1 alpha) to mice before a dose of BZ that causes severe depression of BM cellularity completely prevents BM depression, most probably by bypassing the inability of the stromal macrophage in BZ-treated animals to process pre-IL-1 alpha to the mature cytokine. 相似文献
9.
The results of conventional cerebrospinal fluid (CSF) investigations (CSF cell count, protein and glucose concentrations and Pandy's test for CSF globulin) obtained on admission and sequentially from weekly follow-up lumbar punctures for 4 weeks were evaluated in 99 children (median age 28 months) with stage II (50 children) and stage III (49 children) tuberculous meningitis. On admission, six children (6%) had a CSF cell count greater than 500 x 10(6)/l and nine (9%) a polymorphonuclear predominance. A CSF protein less than 0.8 g/l was found in 17 children (18%) of 97 in whom CSF protein was evaluated. Globulin was either absent or present as a trace only in 26 children (27%). CSF glucose was less than 2.2 mmol/l in 58 cases (60%) and less than 2.5 mmol/l in 67 (69%). In 63 children weekly CSF specimens obtained for the 1st 4 weeks of therapy showed an uninterrupted decline in cell count in 23 (37%), a fluctuating downward trend in 27 (43%) and a fluctuating upward trend in 13 (21%). Sequential CSF protein values in 57 children showed an uninterrupted rise in three (5%), a fluctuating upward course in 19 (33%), an uninterrupted downward trend in seven (12%), and a fluctuating downward course in 28 (49%). Of the 61 children in whom sequential CSF glucose concentrations were available, 11 (18%) experienced fluctuating concentrations, values falling to less than 2.2 mmol/l after being greater than 2.2 mmol/l on admission or after having risen to greater than 2.2 mmol/l.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.
A S Alberts L Schoeman W Burger F Greef G Falkson 《American journal of clinical oncology》1992,15(1):35-36
Thirty-five patients with advanced epidermoid carcinoma of the esophagus were treated with 5-fluorouracil (5-FU) 425 mg/m2 and leucovorin 20 mg/m2, day 1-5 every 28 days. Six patients had a partial response (95% confidence limit, 7-35%) with a median response duration of 32 weeks. The median survival time of the patients on study was 14 weeks. The toxicity was acceptable, with only two patients experiencing severe hematologic toxicity and one patient experiencing severe nausea and vomiting. The addition of leucovorin at this dose level in this population of patients with advanced disease does not appear to enhance the activity of 5-FU for patients with squamous cell cancer of the esophagus. Since only a small percentage of patients experienced significant toxicity, a higher response rate could be achieved in patients treated with the maximally tolerated dose. 相似文献