全文获取类型
收费全文 | 15001篇 |
免费 | 847篇 |
国内免费 | 114篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 273篇 |
妇产科学 | 118篇 |
基础医学 | 2045篇 |
口腔科学 | 382篇 |
临床医学 | 1066篇 |
内科学 | 4252篇 |
皮肤病学 | 176篇 |
神经病学 | 1011篇 |
特种医学 | 790篇 |
外科学 | 2416篇 |
综合类 | 63篇 |
预防医学 | 445篇 |
眼科学 | 158篇 |
药学 | 819篇 |
中国医学 | 14篇 |
肿瘤学 | 1832篇 |
出版年
2023年 | 152篇 |
2022年 | 269篇 |
2021年 | 548篇 |
2020年 | 268篇 |
2019年 | 333篇 |
2018年 | 462篇 |
2017年 | 331篇 |
2016年 | 369篇 |
2015年 | 336篇 |
2014年 | 486篇 |
2013年 | 529篇 |
2012年 | 893篇 |
2011年 | 913篇 |
2010年 | 528篇 |
2009年 | 435篇 |
2008年 | 748篇 |
2007年 | 728篇 |
2006年 | 727篇 |
2005年 | 683篇 |
2004年 | 657篇 |
2003年 | 638篇 |
2002年 | 615篇 |
2001年 | 276篇 |
2000年 | 274篇 |
1999年 | 280篇 |
1998年 | 174篇 |
1997年 | 126篇 |
1996年 | 138篇 |
1995年 | 108篇 |
1994年 | 90篇 |
1993年 | 81篇 |
1992年 | 247篇 |
1991年 | 250篇 |
1990年 | 202篇 |
1989年 | 230篇 |
1988年 | 204篇 |
1987年 | 180篇 |
1986年 | 176篇 |
1985年 | 174篇 |
1984年 | 129篇 |
1983年 | 105篇 |
1982年 | 50篇 |
1981年 | 60篇 |
1979年 | 113篇 |
1978年 | 58篇 |
1977年 | 51篇 |
1975年 | 50篇 |
1974年 | 48篇 |
1973年 | 55篇 |
1968年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Nobuaki Miyazono M.D. Hiroki Inoue Akira Hori Ichiroh Kanetsuki Jurio Shimada Masayuki Nakajo 《Cardiovascular and interventional radiology》1994,17(1):36-37
We present a 44-year-old woman in whom a bronchialto-coronary artery communication via the conus branch was discovered after distal bronchial artery embolization with gelatin sponge for hemoptysis. If this bronchial-to-coronary artery anastomosis, not visible prior to embolization, had been inadvertently embolized, the patient could have developed a myocardial infarction. To reduce the likelihood of a serious complication, the possibility of this anastomosis should be kept in mind and angiography should be repeated before attempting proximal bronchial artery embolization. 相似文献
42.
H Akama MD H Tanaka MD T Yoshida MD H Kameda MD S Kawai MD 《International journal of clinical practice》1994,48(3):161-162
SUMMARY Weber-Christian disease, a disease of unknown aetiology, is characterised by relapsing febrile episodes and systemic panniculitis. Glucocorticoid therapy is often useful during acute phases of the disease. This report describes a patient in whom hyperpyrexia did not respond to high-dose glucocorticoid treatment, yet did respond to a non-steroidal anti-inflammatory drug (NSAID). 相似文献
43.
Tsuyoshi Satoh Tadashi Watanabe Masanori Tadokoro Junichi Sakamoto Hiroki Murayama Katsuki Itoh Sadayuki Sakuma Hiroshi Takagi 《Cancer science》1992,83(4):379-386
Anti-carcinoembryonic antigen monoclonal antibody (MAb) CEA102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with 131 I-labeled intact CEA102 or its F(ab')2 . Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of 131 I-labeled CEA102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the distribution of administered radiolabeled MAb in individual tumors, but the density of the tumors was higher than that of the normal tissues. In the quantitative distribution analysis of CEA102, the uptake of the primary tumor (mean 1.10%ID/kg) was ten-fold greater than that of the normal colon mucosa (mean G.10%ID/kg). These results revealed that the application of MAb has great potential in radioimmunodetection as well as in antibody-directed therapy. 相似文献
44.
We report the surgical results of 13 accessory nerve neurotizations in brachial plexus birth palsy. The mean age at operation was 5.9 months. The accessory nerve was transferred to three C5 roots, to three C6 roots, to four posterior division of the middle trunks, to one musculocutaneous nerve, and to two suprascapular nerves. Sixty-seven percent of the cases acquired M4 or more in the deltoid muscle, 88% in the infraspinatus muscle, and 100% in the biceps brachii muscle. Twenty-five percent of the cases acquired M4 or more in the triceps brachii muscle and the wrist extensor muscles. These results were much better than formerly reported for adult cases by other authors. No functional compromise of the trapezius muscle was noted. The accessory nerve neurotization can be used safely and effectively in neurosurgical reconstruction of the brachial plexus palsy in infants. © 1994 Wiley-Liss, Inc. 相似文献
45.
N-Glycolylneuraminic acid (NeuGc) is distributed in most animals except humans and chickens. However, human and chicken cancerous tissues often synthesize this heterophilic sialic acid as a tumor-associated Hanganutziu-Deicher antigen [M. Naiki and H. Higashi, Adv. Exp. Med. Biol., 152: 445-456, 1982; H. Higashi et al., Cancer Res., 45: 3796-3802, 1985]. In this paper, NeuGc in human cancerous tissues and chicken Marek's disease lymphoma cell lines was determined quantitatively with gas chromatography-mass spectrometry analysis using mass fragmentography. The detectable limit of NeuGc was 40 pg (0.12 pmol) in each injection using 5 ng of trideuteriomethyl ester trideuteriomethyl glycoside of the sialic acid as an internal standard sample when a pair of ions at m/e 386 and 389 was chosen for ion monitoring. NeuGc was detected in ganglioside-rich fractions of various human cancerous tissues from 5 of 8 patients examined but was not detected in glycosphingolipids of normal human tissues. The contents of NeuGc in these cancerous tissues ranged from 0.02 to 0.5% of the total sialic acid content. NeuGc was also detected in freeze-dried samples of 5 different cell lines from chicken Marek's disease lymphomas but was not detected in a cell line from chicken lymphoid leukosis lymphoma and normal chicken skeletal muscle tissue. The contents of NeuGc in the positive cell lines ranged from 0.03 to 0.11% of the total sialic acid content. These results indicate that NeuGc can be synthesized in both humans and chickens in some cancers. 相似文献
46.
M Ishii O Abe H Okura N Okazaki T Kawai Y Saito N Sawabu Y Takamizawa T Takeuchi H Niitani 《Gan to kagaku ryoho. Cancer & chemotherapy》1987,14(8):2548-2555
The CA-50 enzyme immunoassay kit (EIA kit) that has been developed with the use of C-50 monoclonal antibody prepared by L. Lindholm et al. was evaluated for diagnosis of human cancer. The levels of CA-50 in the sera were determined using this kit supplied from Mitsui Pharmaceuticals, Inc. Co. in 759 healthy donors, 728 patients with benign disease and 1,263 untreated patients with cancer. A CA-50 concentration of 40 U/ml of serum was used as the cut-off value. Patients with pancreatic cancer and patients with bile duct cancer had high positive incidence of 75% and 68%, respectively, compared with a low positive incidence of under 40% in patients with other cancers. On the other hand, positive rates in patients with benign disease were as low as 13%. Comparison of the serum levels of CA-50 with CA19-9 in the same samples did not exhibit complete positive correlation in patients with pancreatic cancer, patients with bile duct cancer and patients with liver cancer. These findings indicated that C-50 antibody reacted with two epitopes of CA19-9 and sialosyllactotetraose. From the above results, the usefulness of CA-50 as a tumor marker for pancreatic cancer and bile duct cancer was recognized with this EIA kit. 相似文献
47.
The ontogeny of gamma-melanocyte stimulating hormone (gamma-MSH)-like immunoreactive (gamma-MSHI) structures in the brain and hypophysis was investigated in the rat by means of indirect immunofluorescence. gamma-MSHI neurons in the arcuate nucleus appeared at Day 13 of gestation, in the anterior hypophysis at Day 16, in the intermediate lobe at Day 18, and in the nucleus commissuralis after birth. gamma-MSHI fibers first appeared at Day 15 of gestation in the hypothalamic area and extended dorsally to reach the surface of the diencephalon. At Day 16 of gestation, another gamma-MSHI fiber bundle was found that ran laterally along the ventral surface of the diencephalon. At Day 19, immunoreactive fibers first appeared in the forebrain, diencephalon, midbrain and upper pons, and thereafter they increased in number, reaching a maximum at postnatal Day 15. gamma-MSHI fibers in the lower pons and medulla oblongata first appeared after birth. They also increased in number with age and reached a maximum at postnatal Day 15. The present ontogenetical study has demonstrated the different times of first appearance of each of the 3 major gamma-MSHI structures-containing cell groups in the brain, i.e., the arcuate nucleus, hypophysis and nucleus commissuralis. These findings may reflect the different functions of 3 groups of cells. 相似文献
48.
The ascidian tadpole larva represents the basic body plan of all chordates in a relatively small number of cells and tissue types. Although it had been considered that ascidians develop largely in a determinative way, whereas vertebrates develop in an inductive way, recent studies at the molecular and cellular levels have uncovered several similarities in the way developmental fates are specified. In this review, we describe ascidian embryogenesis and its cell lineages, introduce several characteristics of ascidian embryos, describe recent advances in understanding of the mechanisms of cell fate specification, and discuss them in the context of what is known in vertebrates and other organisms. Developmental Dynamics 236:1748–1757, 2007. © 2007 Wiley‐Liss, Inc. 相似文献
49.
Toshio Kawai Kazunori Mizunuma Tomojiro Yasugi Shun'ichi Horiguchi Masayuki Ikeda 《International archives of occupational and environmental health》1994,66(5):309-315
The validity of two new biological exposure markers of toluene in blood (TOL-B) and toluene in urine (TOL-U) was examined in comparison with that of the traditional marker of hippuric acid in urine (HA-U) in 294 male workers exposed to toluene in workroom air (TOL-A), mostly at low levels. The exposure was such that the geometric mean for toluene was 2.3 ppm with a maximum of 132 ppm; the workers were also exposed to other solvents such as hexane, ethyl acetate, styrene, and methanol, but at lower levels. The chance of cutaneous absorption was remote. Higher correlation with TOL-A and better sensitivity in separating the exposed workers from the nonexposed subjects were taken as selection criteria. When workers exposed to TOL-A at lower concentrations (< 50 ppm, < 10 ppm, < 2 ppm, etc.) were selected and correlation with TOL-A was examined, TOL-B showed the largest correlation coefficient which was significant even at TOL-A of < 1 ppm, whereas correlation of HA-U was no longer significant when TOL-A was < 10 ppm. TOL-U was between the two extremes. The sensitivities of TOL-B and TOL-U were comparable; HA-U showed the lowest sensitivity. Thus, it was concluded that TOL-B is the indicator of choice for detecting toluene exposure at low levels. 相似文献
50.
Masataka Kawai 《Journal of muscle research and cell motility》1986,7(5):421-434
Summary The role of orthophosphate (Pi) ions in crossbridge kinetics was investigated in chemically skinned rabbit psoas fibres in the presence of saturating Ca2+. The muscle length was altered sinusoidally, and the resulting tension time courses were analysed in terms of three exponential processes (A), (B) and (C). Experiments were also performed with step length changes, and the resulting tension transients were correlated with the results of sinusoidal analysis. It was shown that addition of a low millimolar concentration of Pi increased both the rate constant and magnitude of process (B), which resulted in a dramatic increase in the oscillatory power output. The Pi effect was greater at higher oscillation amplitude and at higher MgATP concentration. At 5mm MgATP, the amplitude effect became saturated at a 6 nm length change per crossbridge, whereas the Pi effect did not become saturated in the concentration range tested (0–16mm), An introduction of MgADP to the activating saline resulted in a decrease of all rate constants, and these effects were opposite to MgATP. The effect of Pi resembled neither MgADP nor MgATP. Based on these observations, all the crossbridge reactions except for one (ADP desorption reaction) were eliminated as the possible site of action of Pi ions, supposing that Pi affects only one specific site in the crossbridge cycle. Other mechanisms, which might account for the Pi effects, are the presence of parallel hydrolysis pathways and the presence of multiple sites of action of the Pi ions. 相似文献