全文获取类型
收费全文 | 5726篇 |
免费 | 380篇 |
国内免费 | 239篇 |
专业分类
耳鼻咽喉 | 199篇 |
儿科学 | 61篇 |
妇产科学 | 37篇 |
基础医学 | 420篇 |
口腔科学 | 150篇 |
临床医学 | 381篇 |
内科学 | 416篇 |
皮肤病学 | 47篇 |
神经病学 | 208篇 |
特种医学 | 125篇 |
外国民族医学 | 1篇 |
外科学 | 223篇 |
综合类 | 991篇 |
预防医学 | 564篇 |
眼科学 | 45篇 |
药学 | 940篇 |
1篇 | |
中国医学 | 1384篇 |
肿瘤学 | 152篇 |
出版年
2023年 | 80篇 |
2022年 | 114篇 |
2021年 | 228篇 |
2020年 | 178篇 |
2019年 | 153篇 |
2018年 | 173篇 |
2017年 | 194篇 |
2016年 | 229篇 |
2015年 | 182篇 |
2014年 | 349篇 |
2013年 | 389篇 |
2012年 | 412篇 |
2011年 | 419篇 |
2010年 | 324篇 |
2009年 | 245篇 |
2008年 | 279篇 |
2007年 | 295篇 |
2006年 | 255篇 |
2005年 | 199篇 |
2004年 | 148篇 |
2003年 | 140篇 |
2002年 | 109篇 |
2001年 | 85篇 |
2000年 | 90篇 |
1999年 | 73篇 |
1998年 | 51篇 |
1997年 | 36篇 |
1996年 | 30篇 |
1995年 | 37篇 |
1994年 | 31篇 |
1993年 | 32篇 |
1992年 | 35篇 |
1991年 | 25篇 |
1990年 | 26篇 |
1989年 | 29篇 |
1988年 | 21篇 |
1986年 | 16篇 |
1985年 | 72篇 |
1984年 | 61篇 |
1983年 | 57篇 |
1982年 | 52篇 |
1981年 | 51篇 |
1980年 | 54篇 |
1979年 | 44篇 |
1978年 | 30篇 |
1977年 | 47篇 |
1976年 | 35篇 |
1975年 | 46篇 |
1974年 | 28篇 |
1973年 | 20篇 |
排序方式: 共有6345条查询结果,搜索用时 46 毫秒
31.
Subjects cycled at a work load calculated to elicit 75% of maximal oxygen uptake on two occasions: the first to fatigue (34.5 ± 5.3 min; mean ± SE), and the second at the same workload and for the same duration as the first. Biopsies were obtained from the quadriceps femoris muscle before and immediately after exercise, and 5 min post-exercise. Before the first experiment, muscle glycogen was lowered by a combination of exercise and diet, and before the second, experiment muscle glycogen was elevated. In the low glycogen condition (LG), muscle glycogen decreased from 169 ± 15 mmol glucosyl units kg-1dry wt at to rest to 13 ± 6 after exercise. In the high glycogen condition (HG) glycogen decreased from 706 ± 52 at rest to 405 ± 68 after exercise. Glycogen synthase fractional activity (GSF) was always higher during the LG treatment. During exercise in the HG condition, those subjects who cycled for < 35 min (n= 3) had GSF values in muscle which were lower than at rest, whereas those subjects who cycled for > 35 min (n= 4) had values which were similar to or higher than at rest. Thus the change in GSF in muscle during HG was positively related to the exercise duration (r= 0.94; y = 254–17x + 0.3x2; P < 0.001) and negatively related to the glycogen content at the end of exercise (r=–0.82; y= 516–2x + 0.001x2; P < 0.05). During LG exercise GSF remained constant. GSF increased markedly after 5 min post-exercise in both HG and LG conditions. cAMP dependent protein kinase activity increased similarly during both LG and HG exercise and reverted to the preexercise values 5 min post-exercise. It is concluded that muscle contraction decreases GSF, but low glycogen levels can attenuate or abolish the decrease in GSF. The rapid increase of GSF during recovery from exercise does not require glycogen depletion during the exercise. 相似文献
32.
本文报告了葡萄糖酸锌糖浆的制法及用二甲橙指示剂法测定含量的方法。结果表明制法简便,含量测定方法准确。 相似文献
33.
We report a patient with metastatic thyroid carcinoma invading the esophagus in whom barium and MR examinations revealed an expansile intraluminal mass indistinguishable from that of a primary esophageal malignancy. Metastatic thyroid carcinoma should therefore be included in the differential diagnosis of an expansile esophageal mass. As in our patient, MR imaging may be useful for showing that the mass originates in the thyroid gland. 相似文献
34.
医院门诊药房与医院分离的理性探讨 总被引:4,自引:0,他引:4
中华医院管理学会药事管理专业委员会 《中国医院》2003,7(4):50-54
介绍了医药分业的定义、国外医药分业的目的和少数医院无门诊药房的原因。指出门诊药房从医院分离出去弊大于利,认为门诊药房从医院分离,难以达到预期目的,反而有损于医疗卫生事业的公益性;医药分离削弱、甚至取消了医院对医师不当处方和合理药物治疗等医疗行为的行政和技术监管与干预;医药分离不适合我国的国情,不符合我国卫生体制改革的精神,不利于医疗质量的提高,不利于病人安全、有效、经济用药,不利于调动医院广大药学技术人员的积极性,不利于医院药物治疗管理自动化的实现与信息的传递。建议医药结合的模式必须加强;保留门诊药房,加大监督力度;建立药品配送中心,完善社会化物流机制;加速非处方药药品的发展;在条件成熟后实施处方调剂费;高薪养廉,较大幅度提高医师职业的收入;解决当前医疗体系中分配不合理问题,适当提高挂号、手术、诊疗等收费标准,降低药品收入在医院总收入中所占的比例。 相似文献
35.
Hiroshi Shimada Masao Nanko Shoichi Fujii Hidenobu Masui Shinji Togo Hideyuki Ike Akira Nakano Shigeo Ohki 《Journal of Hepato-Biliary-Pancreatic Surgery》1995,2(2):116-121
Hepatic micrometastases of the parenchyma adjacent to a macroscopic lesion were detected in 17 of 31 resected liver metastases.
Fifty-nine micrometastatic lesions were detected in total; 26 lesions were situated in the portal vein (PV), 22 in the central
vein (CV), 5 in the bile duct (BD), and 6 in the sinusoid (SS). A histological study confirmed the direct invasion of the
macrometastatic cancer cells into the adjacent PV, CV, BD, and SS. According to the tumor doubling time, the mean diameter
of the macrometastases in 19 remnant livers was calculated to have been 0.57±0.87 cm at the time of the primary resection.
The calculated diameter of 3 of these 19 macrometastases was found to be less than 0.01 cm, the minimum implantable size,
indicating that the cancer recurrence in these specimens may have developed from macroscopic metastatic lesions as a satellite,
and not from the primary tumor. In 13 patients who received doses of 5250 mg or more of 5 fluorouracil (FU) via the hepatic
artery, the cumulative disease-free rate 2 years postoperatively was 100%; this value was 47.6% in 11 patients who received
less than 5250 mg of 5 FU via the hepatic artery, and 0% in 39 patients who received no chemotherapy (P<0.005). These results suggest that anatomical hepatic resection for satellite lesions, combined with prophylactic hepatic
arterial chemotherapy for micrometastases, decreases the recurrence rate of hepatic metastases in the remnant liver. 相似文献
36.
Summary In Denmark it is legal to grow opium poppies for the production of poppy seeds and until 1986 for decoration purposes, too. Danish poppy capsules contain 0.3–5 mg morphine per capsule and the content of morphine in opium exuded from the capsules may amount to 24%. This has resulted in misuse as both fresh and dried poppy capsules have been used for the production of opium tea. During the period 1982–1985, seven casualties occurred among drug addicts in Denmark which were solely or partly caused by these opium poppies. 相似文献
37.
暗柳橙(Citrus sinensis Osbeck)第一次生理落果期(3月下旬~4月中旬)的果实外植体脱落过程中,离区纤维素酶A、B的活性明显升高,第二次落果(4月下旬~5月中旬)期的果实脱落过程中,纤维素酶A的活性也显著提高,但纤维素酶B活性变化较小。细胞内、外纤维素酶的活性在外植体脱落过程中也不断升高。2,4—D能明显抑制胞内、外纤维素酶及纤维素酶A的活性,同时还能抑制外植体及非离休果实内乙烯的产生,但对纤维素酶B活性的影响无明显效应。田间喷布低浓度的2,4—D,明显地减少第一次生理落果,但对第二次落果的作用不如赤霉素。本文还讨论了果实的脱落、纤维素酶活性与乙烯之间的相互关系,及2,4—D的调控作用。并认为采用外植体的方法不失为研究脱落问题的有效手段。 相似文献
38.
After injecting a horseradish peroxidase (HRP) solution into the vestibular apparatus in goldfish (Carassius auratus), cells in the medulla oblongata exhibited retrogradely transported HRP reaction product. These labeled cells were confined to 3 nuclei, i.e. the nucleus motorius tegmenti of Bartelmez (with the most prominent labeled cell groups), the ventral vestibular nucleus (Dieter's nucleus) and the medial vestibular nucleus. We consider these labeled cells to be the origin of the efferent innervation to the vestibular apparatus in goldfish. Neurons providing efferent innervation to the sensory periphery in the nucleus motorius tegmenti have, as yet, not been described. 相似文献
39.
M. Vandenbranden J.L. de Coen R. Jeener L. Kanarek J.M. Ruyschaert 《Molecular immunology》1981,18(7):621-631
Interactions between rabbit-γ-immunoglobulins and model membranes (lipid monalayers, planar lipid bilayers, liposomes) have been investigated. No significant interaction was observed with immunoglobulins. However, immunoglobulins dialysed first vs aqueous buffer having pH 2 or 3 and then dialysed against pH 7 buffer presumably adopt a new conformation which allows their bindings to model membranes. This binding is hydrophobic and the immunoglobulin region interacting with the lipid acyl chains is probably located in the heavy chain, as suggested by labelling in this region by a photosensitive probe previously incorporated into the lipid hydrophobic core. Cleavage at the hinge region by papain or pepsin, or heating above 38°C, induces the loss of the hydrophobic conformation responsible for hydrophobic bindings. The binding capacity of immunoglobulins heated above 38°C is restored after momentary dialysis at pH 2. The possible existence of two Ig isomers is discussed in relation to the mechanism of γ-immunoglobulin passage through the endoplasmic membrane and fixation into the plasma membrane. 相似文献
40.
Miroslav Makek Hans Jörg Leu 《Virchows Archiv : an international journal of pathology》1982,397(3):241-250
Summary We present the case of a sacrococcygeal chordoma which recurred 15 years after the radical removal as a soft tissue tumor in the gluteal musculature. This tumor consisted of two parts: a chordoma without symptoms of aggressive cellular proliferation and a malignant fibrous histiocytoma. During the following 4 years several local recurrences of the malignant fibrous histiocytoma occurred in the gluteal musculature. The patient finally died of lung metastases. No chordoma tumor tissue was found in the lungs, in the gluteal musculature or in the sacrococcygeal bone area. Histology including electron microscopy revealed no proof of a transition of chordoma into malignant fibrous histiocytoma. It must be assumed that the secondary soft tissue tumor originated from residual chordoma cells which were implanted during the operation of the primary tumor. It remains unclear whether the malignant fibrous histiocytoma arose from mesenchymal stromal cells within the chordoma or directly from primitive neuroectodermal chorda cells which possess the ability to differentiate into a variety of cell types including mesenchymal cells. 相似文献