全文获取类型
收费全文 | 34904篇 |
免费 | 1638篇 |
国内免费 | 154篇 |
专业分类
耳鼻咽喉 | 370篇 |
儿科学 | 827篇 |
妇产科学 | 458篇 |
基础医学 | 4319篇 |
口腔科学 | 900篇 |
临床医学 | 2189篇 |
内科学 | 8987篇 |
皮肤病学 | 559篇 |
神经病学 | 2689篇 |
特种医学 | 1104篇 |
外科学 | 6301篇 |
综合类 | 155篇 |
一般理论 | 3篇 |
预防医学 | 1066篇 |
眼科学 | 546篇 |
药学 | 2544篇 |
中国医学 | 113篇 |
肿瘤学 | 3566篇 |
出版年
2023年 | 189篇 |
2022年 | 328篇 |
2021年 | 553篇 |
2020年 | 310篇 |
2019年 | 448篇 |
2018年 | 537篇 |
2017年 | 477篇 |
2016年 | 530篇 |
2015年 | 518篇 |
2014年 | 693篇 |
2013年 | 891篇 |
2012年 | 1387篇 |
2011年 | 1465篇 |
2010年 | 903篇 |
2009年 | 772篇 |
2008年 | 1479篇 |
2007年 | 1564篇 |
2006年 | 1633篇 |
2005年 | 1750篇 |
2004年 | 1697篇 |
2003年 | 1663篇 |
2002年 | 1588篇 |
2001年 | 1300篇 |
2000年 | 1386篇 |
1999年 | 1213篇 |
1998年 | 508篇 |
1997年 | 361篇 |
1996年 | 360篇 |
1995年 | 326篇 |
1994年 | 283篇 |
1993年 | 293篇 |
1992年 | 865篇 |
1991年 | 791篇 |
1990年 | 765篇 |
1989年 | 801篇 |
1988年 | 701篇 |
1987年 | 660篇 |
1986年 | 594篇 |
1985年 | 556篇 |
1984年 | 377篇 |
1983年 | 324篇 |
1982年 | 161篇 |
1979年 | 290篇 |
1978年 | 200篇 |
1977年 | 183篇 |
1974年 | 169篇 |
1973年 | 182篇 |
1972年 | 185篇 |
1971年 | 174篇 |
1970年 | 166篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Tanaka Takeo Kobayashi Masao Saito Osamu Kamada Nanao Kuramoto Atsushi Usui Tomofusa 《Clinica chimica acta; international journal of clinical chemistry》1981,117(2):121-131
The biochemical activities of 8 lysosomal acid hydrolases in leukemic cells from 48 patients were examined. Characteristic alterations were found in α-mannosidase, β-galactosidase and N-acetyl-β-glucosaminidase activities of leukemic cells. The level of α-mannosidase activity was much higher in myelo(mono)genous leukemias (AML, AMoL, AMMoL, CML and CMMoL) than in lymphogenous ones (ALL, T-cell leukemia, hairy cell leukemia and CLL) without exception. The β-galactosidase activity also differed as a result of α-mannosidase, except in T-cell leukemia. In T-cell leukemia it was within the range of normal lymphocytes, but in the other lymphogenous leukemias it was significantly below normal. N-acetyl-β-glucosaminidase activity in myelo(mono)genous leukemic cells was above the range of normal granulocytes. The changes in these enzyme levels were consistent. The lymphocytic or myelocytic nature of three cases of acute undifferentiated leukemia could be determined by enzyme studies. In two cases it was lymphocytic and in one it was myelocytic. The enzymatic abnormalities were also found in morphologically mature neutrophils from patients with not only chronic types (CML, CMMoL) but also acute types (AMoL, AMMoL) of leukemias, and were similar to those of their respective leukemic cells. Analysis of lysosomal enzymes (at least three of those mentioned above), can elucidate one of the biochemical properties of leukemic cells and may be valuable in the differentiation of leukemias. 相似文献
12.
A case of Ullrich disease was presented. The patient was a 3-year-old girl with torticollis, generalized muscle weakness and acroatonia since birth. High-arched palate, protruded calcaneus, and mild contracture of proximal joints were also recognized. Intellectual development was normal. Serum level of CPK was slightly increased. In histological and histochemical examinations of quadriceps femoris muscle, proliferated connective tissue, marked variation in the muscle fiber diameter, and a lot of degenerated and regenerated fibers were recognized. Minimal injury easily causes subcutaneous hemorrhage, but no abnormality was found in the structure of collagen. 相似文献
13.
14.
S Yamaguchi H Fujii S Kaneko S Yachiku F Inada T Anzai T Kobayashi K Furuta H Ishida 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1991,82(10):1561-1567
Ultrasonotomograms of 22 kidneys were obtained in 11 patients with renal-acute renal failure (renal-ARF). The underlying diseases of renal-ARF were acute tubular necrosis in 8 patients and acute on-set chronic glomerulonephritis in 3 patients. They were treated by hemodialysis in 10 patients and intermittent peritoneal dialysis in 1 patient. Ultrasonic measurement of the size of kidneys revealed that the thickness (anterior-posterior diameter) and the ratio of thickness to length (T/L) were greater in patients with ARF than in those with chronic renal failure and normal renal function. The patients with a low value of T/L (under 0.60) had a significantly greater urine volume than those with high a value of T/L (0.60 or more). The sonographic features of renal-ARF kidneys were marked increase in parenchymal echogenicity and appearance of hypoechoic swollen renal pyramids with sharpness of the corticomedullary border. In the course of ARF, these sonographic changes gradually disappeared when the patients had recovered from ARF. However, the prognosis was poor in patients with severer sonographic findings. We believe that repeated ultrasonic examination of the kidneys in patients with renal-ARF is useful for not only differential diagnosis of post-renal urinary obstruction but evaluating the course of ARF. 相似文献
15.
A 67-year-old woman, who presented polyneuropathy, pleural effusion, ascites and sclerosing changes in the ribs, was admitted to our hospital on June 17, 1987. On admission, cerebrospinal examination showed a marked protein-cell dissociation and a delay in nerve conduction velocity. Bence-Jones protein was detected in urine, and the immunohistochemical study of biopsied bone marrow of the rib revealed lambda-chain positive plasmacytoma. Serum immunoelectrophoresis, however, showed no monoclonal gamma-globulinemia. From the findings described above, she was diagnosed as having Crow-Fukase syndrome associated with lambda-type light chain disease. Even with a therapy by prednisolone, platelet counts progressively declined to 10,000/ml3. Bone marrow aspiration showed normal number of megakaryocytes. Since platelet-associated IgG was increased to 452 ng/1.0 x 10(8) plt, a diagnosis of autoimmune thrombocytopenia was considered. Melphalan and cyclophosphamide to plasmacytoma resulted in a marked improvement of platelets. In addition, the level of platelet-associated IgG returned to normal range. Polyneuropathy, however, didn't respond to those therapies. It was suggested that both Crow-Fukase syndrome and thrombocytopenia were closely concerned with plasmacytoma but developed in a different manner. 相似文献
16.
17.
Liver histopathology in clinical Reye syndrome 总被引:1,自引:0,他引:1
Analysis of the liver histopathology in 19 children with clinical Reye syndrome (RS) revealed that nine had diffuse panlobular steatosis, one giant cell hepatitis, one a mild choledochal cyst with inflammation, two multifocal spotty necrosis and one multiple centrilobular necrosis, the other five being normal. Four of the nine patients with diffuse panlobular steatosis showed microvesicular fatty droplets with central nuclei, which was consistent with findings characteristic for typical RS. Two cases showed a periportal area dominant macrovesicular fatty change, which was highly suggestive for metabolic disorder. In the other three cases, the findings were so variable in terms of the size of lipid droplets and the location of nuclei in hepatocytes that it was not possible to provide any clue for defining a diagnosis. These results confirmed the legitimacy of the diagnostic criteria of RS which included a liver biopsy as one of the mandatory conditions. They also indicated that RS-mimicking clinical pictures can be presented by miscellaneous conditions in which liver histology does not necessarily helpful in establishing definite diagnosis. 相似文献
18.
In order to examine the cholecystohepatic circulation of trichloroethylene (TRI) and its metabolites, we injected the gallbladder with TRI and its metabolites, i.e. chloral hydrate (CH), free-trichloroethanol (F-TCE), trichloroacetic acid (TCA) and conjugated-trichloroethanol (Conj-TCE), using anesthetized dogs. The absorption rates of water from the gallbladder were 25-30% 2 h after administration for all substances. The absorption rates of substances were 65-70% in the CH, F-TCE and TRI groups, and 40-50% in the Conj-TCE and TCA groups 2 h after the administration. Conj-TCE in the blood absorbed from the gallbladder has a tendency to be directly transported to the venous system rather than to be taken into hepatocytes in the liver. All of the administered substances, in particular, F-TCE might be metabolized to other substances in the gallbladder. 相似文献
19.