全文获取类型
收费全文 | 21337篇 |
免费 | 1068篇 |
国内免费 | 206篇 |
专业分类
耳鼻咽喉 | 171篇 |
儿科学 | 403篇 |
妇产科学 | 179篇 |
基础医学 | 2495篇 |
口腔科学 | 413篇 |
临床医学 | 1263篇 |
内科学 | 6497篇 |
皮肤病学 | 435篇 |
神经病学 | 1313篇 |
特种医学 | 824篇 |
外科学 | 3505篇 |
综合类 | 80篇 |
一般理论 | 3篇 |
预防医学 | 573篇 |
眼科学 | 488篇 |
药学 | 1278篇 |
中国医学 | 51篇 |
肿瘤学 | 2640篇 |
出版年
2023年 | 177篇 |
2022年 | 349篇 |
2021年 | 608篇 |
2020年 | 348篇 |
2019年 | 461篇 |
2018年 | 505篇 |
2017年 | 407篇 |
2016年 | 502篇 |
2015年 | 526篇 |
2014年 | 692篇 |
2013年 | 830篇 |
2012年 | 1359篇 |
2011年 | 1568篇 |
2010年 | 889篇 |
2009年 | 693篇 |
2008年 | 1166篇 |
2007年 | 1372篇 |
2006年 | 1314篇 |
2005年 | 1275篇 |
2004年 | 1178篇 |
2003年 | 1080篇 |
2002年 | 1104篇 |
2001年 | 346篇 |
2000年 | 311篇 |
1999年 | 310篇 |
1998年 | 269篇 |
1997年 | 230篇 |
1996年 | 199篇 |
1995年 | 162篇 |
1994年 | 134篇 |
1993年 | 129篇 |
1992年 | 185篇 |
1991年 | 173篇 |
1990年 | 182篇 |
1989年 | 187篇 |
1988年 | 164篇 |
1987年 | 155篇 |
1986年 | 159篇 |
1985年 | 143篇 |
1984年 | 90篇 |
1983年 | 81篇 |
1982年 | 46篇 |
1981年 | 42篇 |
1980年 | 41篇 |
1979年 | 48篇 |
1978年 | 36篇 |
1977年 | 35篇 |
1975年 | 32篇 |
1974年 | 40篇 |
1968年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Full-length human thyroid hormone receptor alpha 1 (hTR alpha 1) was expressed in Escherichia coli using a T7 expression system. While present in large amounts, the receptor was highly enriched in the insoluble fraction after cell lysis. We describe here the successful solubilization and refolding of the expressed receptor in a functional form in the presence of Zn2+. Using a DNA-cellulose binding assay and gel shift assay, we found that treatment of expressed receptor with 1 mM EDTA in the denaturing agent (5 M guanidine-HCl) results in the formation of aporeceptor that does not specifically recognize target DNA, while it does retain T3-binding activity. This aporeceptor recovered DNA-binding activity by adding Zn2+ during refolding. Zinc-induced restoration of DNA-binding activity occurred in a dose- and time-dependent manner. Moreover, once recovered, this DNA-binding activity persisted without Zn2+, even in the presence of 1 mM EDTA. These data indicate that the hTR alpha 1 molecule has a high affinity for Zn2+, and this metal coordination is essential for proper folding of TR protein into its native active structure. 相似文献
72.
S Yamaguchi M Kyakuno M Osafune M Sakurai H Nakamura 《Hinyokika kiyo. Acta urologica Japonica》1990,36(1):55-58
A case of renal schwannoma is presented. A 51-year-old female was admitted to our hospital because of a left renal mass on April, 16, 1987. A drip infusion pyelogram showed encasement of the lower and medial calyx. An abdominal CT-scan showed a 2.5 cm mass with irregular density. Selective left renal arteriography showed the hypovascular tumor of the left kidney. Transperitoneal radical nephrectomy was performed on May, 1, 1987. Histological diagnosis was renal schwannoma arising from renal pelvis. The patient was well without recurrence 20 months after operation. Our present case is the 12th case of renal schwannoma reported in the English and Japanese literature. 相似文献
73.
74.
M Sakurai S Shibuya J Miyagishima E Wakamatsu 《The Japanese journal of antibiotics》1986,39(3):739-745
Cefotaxime (CTX) was intravenously administered in an amount of 2.0 g to each of 34 adult patients before the surgery mainly of the hip joint. Samples of the blood from the bone marrow around the trochanter were taken at the time of the operation. At the same time blood samples were taken from peripheral veins. The sample was centrifuged and the supernatant was analyzed for CTX and desacetyl-CTX. The concentration of CTX in the marrow blood was 150.9 micrograms/ml and that in the blood was 182.5 micrograms/ml in the earliest samples taken at 20 minutes after injection. In the 44 pairs of samples, the concentration of CTX in the marrow blood was lower than that in the peripheral blood in all the cases except 4. The concentration of desacetyl-CTX (Des-CTX), however, in the marrow blood was higher than in the peripheral blood in 33 of the 44 pairs of specimens. Since the degradation of the drug progresses with time, the ratio of Des-CTX to CTX increased with time. This trend was particularly marked in the bone marrow blood and can be expressed as Y = 113.0 + 0.32 t, when Y is the ratio percentage (Des-CTX/CTX) and t is time after the injection of the drug in minute. Thus, CTX transferred into the bone marrow tends to remain there and transformed into the desacetyl form. 相似文献
75.
76.
Combined large cell neuroendocrine carcinoma 总被引:1,自引:0,他引:1
Toshiya Bessho Keiya Yokochi Teruhisa Sakurai 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(9):426-428
We report a case of combined large cell neuroendocrine carcinoma. A 78-year-old man with vertigo was referred to our hospital
where chest X-ray revealed a tumor shadow in the right lung. A transbronchial lung biopsy specimen verified a diagnosis of
non-small cell lung carcinoma (cT1N0M0). Right lower lobectomy with mediastinal lymph node dissection (#7,8,9) was performed.
A postoperative histological diagnosis was combined large cell neuroendocrine carcinoma of a component of squamous cell carcinoma
[pT4 (pm) N2M0]. The patient received concurrent chemoradiotherapy due to upper mediastinal lymph node metastasis 4 months
after surgery. The chemoradiotherapy well responded and the patient remains well 9 months after surgery. 相似文献
77.
Select types of supporting cell in the inner ear express aquaporin-4 water channel protein 总被引:14,自引:0,他引:14
Yutaka Takumi Erlend Arnulf Nagelhus Jo Eidet Atsushi Matsubara Shin-ichi Usami Hideichi Shinkawa Søren Nielsen Ole Petter Ottersen 《The European journal of neuroscience》1998,10(12):3584-3595
Aquaporins (AQPs) confer a high water permeability on cell membranes and play important parts in secretory and absorptive epithelia in kidney and other organs. Here we investigate whether AQPs are expressed in the sensory epithelia of the inner ear, where a precise volume regulation is crucial. By use of specific antibodies it was found that the inner ear contains AQP1 and 4 while being devoid of detectable levels of AQP2, 3 or 5. Immunofluorescence and postembedding immunogold labelling revealed a strictly non-epithelial distribution of AQP1, confirming previous data. In contrast, AQP4 protein and mRNA (visualized by in situ hybridization) were concentrated in select types of supporting cell, including Hensen's cells and inner sulcus cells. Immunogold particles signalling AQP4 were confined to the basolateral plasma membrane of Hensen's cells and to the basal plasma membrane of Claudius cells and inner sulcus cells. AQP4 was also found in supporting cells of the vestibular end organs, but was absent from transitional epithelial cells and dark cells. Strong labelling for AQP4 and AQP4-mRNA was associated with the central part of the cochlear and vestibular nerves. Hair cells were consistently unlabelled. Our findings indicate that AQP4 may facilitate osmotically driven water fluxes in the sensory epithelia of the inner ear and thus contribute to the volume and ion homeostasis at these sites. 相似文献
78.
We report herein the case of a 56-year-old woman who developed secondary Kwashiorkor 9 years after undergoing a total gastrectomy for early gastric cancer. Until she began developing the symptoms of Kwashiorkor, including general fatigue, edema of the face and extremities, anemia, alopecia, and weight loss, she had been leading a normal life post-gastrectomy. Her symptoms were alleviated by total parenteral nutrition (TPN) therapy, but reappeared soon after TPN therapy was discontinued. Therefore, she required several subsequent courses of TPN. In an attempt to permanently resolve the ongoing Kwashiorkor symptoms, reconstructive surgery involving transposition of the jejunum from the previous Graham method to the interposition method was performed 10 years after the initial gastrectomy. After the second operation, her malnutrition was completely alleviated, and she has been in good health for the 8 years since. To our knowledge, there has been no other report of the symptoms of secondary Kwashiorkor after total gastrectomy being alleviated by altering the procedure of reconstruction of the intestinal tract. Thus, we recommend surgical treatment to alter the digestive continuity to a more physiological pathway for selected patients with secondary Kwashiorkor syndrome. 相似文献
79.
Abdullah Bereket Thomas A. Wilson Sandra L. Blethen Yoichi Sakurai David N. Herndon Robert R. Wolfe Charles H. Lang 《Clinical endocrinology》1996,44(5):525-532
OBJECTIVE Little information is available regarding the regulation of serum acid-labile subunit (ALS) in human disease. We have studied alterations in serum ALS of the insulin-like growth factor (IGF) ternary complex in children with untreated insulin-dependent diabetes mellitus (IDDM) and subjects with severe burns before and after insulin therapy. In addition, we have investigated the effect of insulin plus GH on serum ALS in burn patients. DESIGN Serum samples were obtained from children with newly diagnosed and untreated IDDM before the initiation of insulin therapy and 1 month thereafter. Serum samples were also obtained from adult patients with severe burns who were on a continuous infusion of a carbohydrate-rich enteral diet via nasogastric and duodenal catheters under basal conditions, after a 1-week period of continuous insulin infusion, and after an additional week of insulin plus recombinant GH. PATIENTS Twenty children and adolescents with untreated IDDM, aged 1.2–16 years, and 6 young adult patients with severe burns aged 17–28 years were studied longitudinally. Control sera were obtained from age, sex and pubertal status matched subjects (for children with IDDM) and from fed healthy adults. MEASUREMENTS Serum insulin, GH, cortisol and IGF-I were measured by radioimmunoassay, and serum ALS levels were assessed by Western immunoblot before and after treatment periods. RESULTS Serum ALS levels were lower in untreated children with IDDM (69 ± 6% of control children). Insulin therapy significantly increased serum ALS (79 ± 5%, P<0.05) in these children. Patients with severe burns also had lower serum ALS levels (79 ± 10% of control adults). After one week of insulin therapy serum ALS levels increased to 90 ± 15% of control values (P<0.05). Addition of GH to insulin therapy for another week did not significantly further increase serum ALS levels (95 ± 27%). Serum IGF-I concentrations increased nearly 2.5-fold in diabetic subjects and fourfold in burn subjects at the end of the study periods. There were no proteolytic fragments of ALS in the sera studied. The deglycosylation pattern of ALS did not differ between diabetic and control sera. CONCLUSION Serum ALS levels were diminished in children with untreated IDDM and were partially restored after the initiation of insulin therapy. Serum ALS levels were also diminished in patients with severe burn injury and restored by insulin treatment. Addition of GH to insulin therapy did not significantly increase serum ALS levels over levels obtained during insulin therapy alone. These decreases in serum ALS were smaller than the decrease in serum IGF-I concentrations in both conditions, suggesting that IGF-I is the limiting factor for the ternary complex formation in the catabolic states. Insulin may regulate circulating ALS levels in catabolic states and helps to restore the IGF system. 相似文献
80.
Shohachi Suzuki Satoshi Nakamura Hideki Ishida Takanori Sakaguchi Atsushi Serizawa Hiroyuki Konno Shozo Baba Hiroyuki Muro Isao Kosugi Eisaku Gu 《Surgery today》1996,26(8):635-639
Hepatic angiomyolipoma is a rare tumor composed of spindle-shaped and epithelioid smooth muscle cells, adipose tissue, and proliferating blood vessels. We report the first documented case of this tumor developing in a patient with ulcerative colitis. A solitary tumor (7.5×7.5×7cm) was detected in the left lateral segment of the liver and a left hepatic lobectomy was performed. The diagnosis of angiomyolipoma was confirmed by a pathological examination. We also review the literature on previously reported cases of hepatic angiomyolipoma. 相似文献