全文获取类型
收费全文 | 56502篇 |
免费 | 5276篇 |
国内免费 | 4110篇 |
专业分类
耳鼻咽喉 | 349篇 |
儿科学 | 484篇 |
妇产科学 | 567篇 |
基础医学 | 6554篇 |
口腔科学 | 1026篇 |
临床医学 | 7821篇 |
内科学 | 8041篇 |
皮肤病学 | 494篇 |
神经病学 | 2827篇 |
特种医学 | 2042篇 |
外国民族医学 | 42篇 |
外科学 | 5365篇 |
综合类 | 10364篇 |
现状与发展 | 19篇 |
一般理论 | 1篇 |
预防医学 | 3737篇 |
眼科学 | 1775篇 |
药学 | 6152篇 |
39篇 | |
中国医学 | 3506篇 |
肿瘤学 | 4683篇 |
出版年
2024年 | 228篇 |
2023年 | 1037篇 |
2022年 | 2535篇 |
2021年 | 3258篇 |
2020年 | 2337篇 |
2019年 | 1891篇 |
2018年 | 2121篇 |
2017年 | 1799篇 |
2016年 | 1750篇 |
2015年 | 2733篇 |
2014年 | 3378篇 |
2013年 | 2775篇 |
2012年 | 4164篇 |
2011年 | 4671篇 |
2010年 | 2701篇 |
2009年 | 2238篇 |
2008年 | 2849篇 |
2007年 | 2858篇 |
2006年 | 2861篇 |
2005年 | 2855篇 |
2004年 | 1887篇 |
2003年 | 1749篇 |
2002年 | 1503篇 |
2001年 | 1202篇 |
2000年 | 1282篇 |
1999年 | 1334篇 |
1998年 | 899篇 |
1997年 | 840篇 |
1996年 | 653篇 |
1995年 | 613篇 |
1994年 | 515篇 |
1993年 | 313篇 |
1992年 | 393篇 |
1991年 | 311篇 |
1990年 | 289篇 |
1989年 | 241篇 |
1988年 | 225篇 |
1987年 | 172篇 |
1986年 | 143篇 |
1985年 | 105篇 |
1984年 | 46篇 |
1983年 | 42篇 |
1982年 | 18篇 |
1981年 | 20篇 |
1980年 | 15篇 |
1979年 | 15篇 |
1977年 | 2篇 |
1973年 | 2篇 |
1935年 | 4篇 |
1910年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
本实验采用血管铸型扫描电镜,注射明胶卡红组织切片显微镜下观察和注射铅丹乳胶追踪血管来源三种方法对14只健康大白鼠肾上腺血管构筑进行了研究。大白鼠肾上腺动脉发自腹主动脉和肾动脉。它们在行程中发出分支至腺体表面,再次分支穿入囊内,逐级分支至毛细血管。皮质动脉发自囊内血管,它们在皮质中分支分布。球状带的毛细血管与囊的毛细血管相连,毛细血管在球状带围绕细胞团形成网眼状;在束状带呈放射状排列;在网状带吻合增多形成网状。髓质动脉亦发自囊的血管,它们在皮质中不发分支直抵髓质,在髓质分成毛细血管。网状带的毛细血管越向髓质口径越粗,它们在皮髓交界处互相吻合形成更粗的静脉,这些静脉逐级吻合,最后形成一主干——中央静脉,它穿出皮质出现于肾上腺门处。左侧的中央静脉注入在肾静脉,右侧的注入下腔静脉。 相似文献
52.
甘利欣联合654-2治疗慢性乙型肝炎60例疗效观察 总被引:2,自引:0,他引:2
目的观察甘利欣联合654-2治疗慢性乙型肝炎的临床疗效。方法采用甘利欣联合654-2治疗慢性乙型肝炎患者60例。治疗4w和8w时,分别观察临床症状、体征及肝功能(包括ALT和TB)的变化。结果ALT、TB恢复程度以治疗组为高,与对照组比较有统计学差异(P<0.05)。采用甘利欣联合654-2治疗8w后,总有效率为96.6%。结论甘利欣联合654-2治疗慢性乙型肝炎的治疗较疗效满意。 相似文献
53.
组织多肽特异性抗原在乳腺癌中的临床研究 总被引:16,自引:1,他引:15
Hang Zheng Ben-fu He Rong-cheng Luo Chang-xuan You Guo-feng Mai Hui-fang Lu 《第一军医大学学报》2003,23(8):823-825
OBJECTIVE: To investigate the expression of serum tissue polypeptide-specific antigen (TPS) in breast cancer patients and its clinical value in such cases. METHODS: Altogether 160 subjects (90 patients with breast cancer, 40 with benign breast lesions, and 30 healthy subjects) were enrolled in this study. The serum TPS and CA153 levels were measured by ELISA in all the subjects. RESULTS: The levels and positivity rate of serum TPS and CA153 in breast cancer group were significantly higher than those in the normal subjects group and benign lesion group (P<0.01), and became even higher as the malignancy progressed. High serum TPS level was detected in the cancer patients in stage I. Serum TPS level was the most sensitive to bone metastasis of the malignancy, but its highest levels occurred in cases of lymphoid node metastasis (P<0.05). In patients who responded favorably to the treatment, serum TPS and CA153 levels were significantly reduced (P<0.05), but the reduction in TPS levels tended to be more obvious (P<0.05). CONCLUSION: Serum TPS can be used as a very useful and sensitive tumor marker in the diagnosis of breast cancer, especially in case of bone metastasis, and may be of great value in clinical decision-making and assessment of therapeutic effect. 相似文献
54.
Jiang He Mary Rusckowski Yi Wang Shuping Dou Xinrong Liu Surong Zhang Guozheng Liu Donald J. Hnatowich 《Molecular imaging and biology》2007,9(1):17-23
Objective Pretargeting with radioactivity has significantly improved tumor to normal tissue radioactivity ratios over conventional antibody
imaging in both animal studies and clinical trials. This laboratory is investigating DNA analogues such as phosphorodiamidate
morpholinos (MORFs) for pretargeting using technetium-99m (99mTc) for detection. However, the unique properties of fluorescence activation and quenching combined with oligomers with their
unique properties of hybridization may be particularly useful when used together for pretargeting with optical detection.
The use of linear fluorophore-conjugated oligomer duplexes have been little used in animals, and to our knowledge, have not
previously been considered for pretargeting applications.
Methods A MORF/cDNA pair was selected such that when hybridized, the fluorescence of the Cy5.5-conjugated 25 mer MORF (Cy5.5–MORF25)
is inhibited with a BHQ3-conjugated 18 mer complementary DNA (BHQ3–cDNA18). The short BHQ3–cDNA18 was selected to dissociate
in the presence of a long cMORF25 in the pretargeted tumor, thus releasing the inhibitor from the Cy5.5 emitter. In this manner,
the Cy5.5 fluorescence will be inhibited everywhere but in the target. The dissociation was first examined in vitro by adding the duplex to the cMORF25 both in solution and immobilized on polystyrene microspheres and by surface plasmon resonance
(SPR). Thereafter, biotinylated cMORF25 immobilized on streptavidin polystyrene microspheres were administered intramuscularly
in one thigh of hairless SKH-1 mice as target while an identical weight of the identical microspheres but without the cMORF25
was administered in the contralateral thigh as control. The animals then received IV the Cy5.5–MORF25/BHQ3–cDNA18 duplex or
equal molar dosage of single-chain Cy5.5–MORF25 and were imaged.
Results The SPR studies showed that the immobilized cDNA18 rapidly captured the flowing MORF25 to provide a duplex with a slow dissociation
rate constant. Furthermore, when cMORF25 was next allowed to flow over the now immobilized duplex, the cDNA18 was unable to
prevent dissociation of the heteroduplex and the formation and release of the cMORF25-MORF25 homoduplex. Images of animals
obtained soon after receiving the Cy5.5–MORF25 singlet showed intense whole body fluorescence obscuring the target thigh.
However, only 5 minutes after receiving the Cy5.5–MORF25/BHQ3–cDNA18 duplex, the target thigh was clearly visible along with
only the kidneys.
Conclusions This first study of optical pretargeting provides a proof of concept that oligomer pretargeting found to be useful with radioactivity
detection is applicable with fluorescent detection as well. In addition, our results demonstrate that by using linear oligomers
for optical pretargeting, chain lengths (and base sequences) may be manipulated to provide duplexes with stabilities and fluorescence
inhibition optimized for pretargeting and other in vivo applications of optical imaging. 相似文献
55.
目的:分析肾移植后免疫抑制剂对长期存活的影响,寻找移植后不同时间合适的免疫抑制用药方案及其用药剂量。 方法:对肾移植一年以上、肾功能正常的497例患者进行5年连续随访。根据移植后2、3、5年的不同免疫抑制用药将患者分为三联、二联、传统二联治疗三组。统计各组的排异发生率,排异和无排异患者免疫抑制用药的种类、剂量及CsA浓度,对排异患者追踪排异发生前12个月内的药物更动情况。 结果:肾移植后2、3、5 相似文献
56.
Ultraviolet Laser-Induced Fluorescence Spectroscopy Diagnosis of Human Stomach Malignant Tissues 总被引:2,自引:0,他引:2
To evaluate the potential of laser-induced autofluorescence spectroscopy for the detection of premalignant lesions of human
stomach, fluorescence properties of stomach tissues have been investigated in vitro and in vivo. A specially made optical
fibre probe and the multichannel fluorescence collection system have been used successfully in our research.
Paper received 26 June 1997; accepted in revised form 31 October 1997. 相似文献
57.
58.
X. He C. J. Wikstrand P. Fredman J.-E. Månsson L. Svennerholm D. D. Bigner 《Acta neuropathologica》1989,79(3):317-325
Summary Seven monoclonal antibodies (mAbs) reactive with ganglioside II3(NeuAc)2-LacCer (GD3) were generated; four of these mAbs (DMAb-21, DMAb-22, DMAb-23, and DMAb-24) by immunizing mice with GD3 adsorbed to Salmonella minnesota and the remaining three (DMAb-7, DMAb-8, and DMAb-17) with melanoma line SK-MEL 28, which contains 1.4 nmol sialic acid of GD3 per mg protein. The specificities of the mAbs were defined by high-performance thin-layer chromatography (HPTLC) immunostain and solid-phase radioimmunoassay (SP-RIA) with a panel of purified gangliosides. DMAb-7 and DMAb-8 reacted with GD3, IV3(NeuAc)2nLcOse4Cer(3,8-LD1), and very weakly with IV3(NeuAc)2II3NeuAc-GgOse4Cer (GTla), but not with II3NeuAc-LacCer (GM3), II3NeuAcGgOse3Cer(GM2), II3NeuAc-GgOse4Cer(GM1), II3NeuAc, IV3NeuAcGgOse4Cer (GD1a), II3(NeuAc)2GgOse3(GD2), II3(NeuAc)2GgOse4Cer (GD1b), IV3NeuAcII3(NeuAc)2, GgOse4Cer(GT1b), suggesting the binding epitope to be a terminal tetrasaccharide NeuAc2-8NeuAc2-3Gal1-4(Glc or GlcNAc). DMAb-7 and DMAb-8 were used to investigate the expression of GD3 on cultured human tumor cells of neuroectodermal origin. Thirteen of 19 gliomas, 3 of 5 medulloblastomas, 5 of 5 neuroblastomas, 2 of 2 melanomas, and 1 of 3 teratomas were shown to react with DMAb-8 and/or DMAb-7 by cell surface-RIA (CS-RIA) and immunofluorescence (IF) assays. HPTLC and densitometric analysis confirmed these results, as positive immunostains in the GD3 region were obtained with oligoganglioside fractions from 9 glioma, 1 medulloblastoma, 2 neuroblastoma, 1 melanoma, and 1 teratoma cell line. Glioma cell line U-105 MG and medulloblastoma cell line Daoy contain GD3 as shown by HPTLC immunostain analysis of extracts, although GD3 was undetectable on the cell surface as determined by CS-RIA and IF. There was no detectable GD3 found in gangliosides isolated from cell lines U-373 MG, D-54 MG, TE-671, and PA-1, which were negative for both DMAb-7 and DMAb-8 by CS-RIA and IF assay. Our results provide evidence that GD3 is expressed extensively with significant quantitative heterogeneity on cultured human neuroectodermal tumor cells including glioma, medulloblastoma, neuroblastoma, and melanoma.Supported by NIH grants R37 CA11898, NS 20023, and CA32672 and by grants from the Swedish Medical Research Council (project no. 03X-627), Swedish Cancer Society (project no. 2260-B88-01X) and the National Swedish Board for Technical Development (project no. 84-4667) 相似文献
59.
Ehteshami G Singh A Coryell G Massia S He J Raupp G 《Journal of biomaterials science. Polymer edition》2003,14(10):1105-1116
Photosensitive benzocyclobutene (photo-BCB) is a class of polymers with the trade name Cyclotene. The photoimagable property of Cyclotene makes it suitable for the manufacture of microelectronic devices. The motivation behind this study is that we see an exciting application of photo-BCB as substrates in implantable microelectronic biomedical devices due to several desirable properties distinctive from other polymer materials. To our knowledge, however, photo-BCB has never been tested for biomedical implant applications, as evidenced by the lack reported data on its biocompatibility. This study takes the first step towards assessing photo-BCB biocompatibility by evaluating the cytotoxicity and cell adhesion behavior of Cyclotene 4026 coatings exposed to monolayers of glial and fibroblast cells in vitro. It can be concluded from these studies that photo-BCB films deposited on silicon wafers using microfabrication processes did not adversely affect 3T3 fibroblast and T98-G glial cell function in vitro. We also successfully rendered photo-BCB films non-adhesive (no significant fibroblast or glial cell adhesion) with surface immobilized dextran using methods developed for other biomaterials and applications. Future work will further develop prototype photo-BCB microelectrode devices for chronic neural implant applications. 相似文献
60.
Dipole-tracing of 'awareness' attenuating the cortical components of somatosensory evoked potentials 总被引:1,自引:0,他引:1
Using the dipole-tracing method, the source generators of N18, P22 and P40 of the somatosensory evoked potential (SEP) were estimated as the equivalent dipole. After voluntary action of the thumb flexion, no changes were observed in N18 or P40, but the amplitude of P22 was suppressed. The after-effects of intention accompanied by a voluntary action or the subject's awareness that electrical stimulation will be given after the voluntary action were treated as 'awareness'. By subtracting the pure SEP from SEP during 'awareness', it was found that the equivalent dipole of 'awareness' of P22 was located at the same region of pure P22, but the vector was of opposite orientation. 'Awareness' attenuated the perceptive potential of SEP like P22 generated in the cortex. 相似文献