全文获取类型
收费全文 | 6569篇 |
免费 | 322篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 164篇 |
儿科学 | 123篇 |
妇产科学 | 41篇 |
基础医学 | 780篇 |
口腔科学 | 136篇 |
临床医学 | 459篇 |
内科学 | 1609篇 |
皮肤病学 | 57篇 |
神经病学 | 507篇 |
特种医学 | 243篇 |
外科学 | 1373篇 |
综合类 | 33篇 |
一般理论 | 1篇 |
预防医学 | 264篇 |
眼科学 | 44篇 |
药学 | 261篇 |
中国医学 | 6篇 |
肿瘤学 | 853篇 |
出版年
2024年 | 6篇 |
2023年 | 46篇 |
2022年 | 80篇 |
2021年 | 149篇 |
2020年 | 85篇 |
2019年 | 117篇 |
2018年 | 166篇 |
2017年 | 125篇 |
2016年 | 194篇 |
2015年 | 184篇 |
2014年 | 253篇 |
2013年 | 269篇 |
2012年 | 449篇 |
2011年 | 492篇 |
2010年 | 309篇 |
2009年 | 269篇 |
2008年 | 410篇 |
2007年 | 443篇 |
2006年 | 466篇 |
2005年 | 453篇 |
2004年 | 436篇 |
2003年 | 390篇 |
2002年 | 336篇 |
2001年 | 60篇 |
2000年 | 54篇 |
1999年 | 71篇 |
1998年 | 100篇 |
1997年 | 55篇 |
1996年 | 65篇 |
1995年 | 55篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 30篇 |
1991年 | 21篇 |
1990年 | 34篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 15篇 |
1986年 | 15篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 8篇 |
1980年 | 20篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1969年 | 5篇 |
排序方式: 共有6954条查询结果,搜索用时 31 毫秒
991.
Sakakura M Nishii K Usui E Monma F Tsukada T Shiku H 《International journal of hematology》2006,83(3):252-253
All-trans retinoic acid (ATRA) is the drug of choice for the treatment of acute promyelocytic leukemia (APL). In general, ATRA is well tolerated, but it does have side effects, the most severe of which is ATRA syndrome. We report the case of a young patient with APL treated with ATRA for induction and maintenance therapy who then developed avascular necrosis of both femoral heads. We also review cases of APL patients with osteonecrosis of the femoral head after ATRA therapy. 相似文献
992.
AIMS: To clarify the influence of Erabu sea snake lipid on levels of plasma insulin and adipocyte-derived hormones. METHODS: Normal male mice (6 months) and streptozotocin-diabetic mice (a single administration, 150 mg/kg i.p.) were fed diets containing 10% fat as either lard or a mixture of 5% lard and 5% sea snake lipid for 4 months. RESULTS: The normal mice on the sea snake lipid diet had a significantly lower plasma glucose concentration (198 +/- 16 mg/dl; 148 +/- 11 mg/dl) than those mice on the lard diet. Although plasma insulin concentrations were not influenced by the dietary fat type, leptin (10 +/- 1 ng/ml; 16 +/- 2 ng/ml) and adiponectin (18 +/- 1 mug/ml; 21 +/- 1 mug/ml) concentrations were significantly higher in the sea snake lipid group than in the lard group. However, these effects of a sea snake lipid intake were not evident in the streptozotocin-diabetic mice. CONCLUSION: The results suggest that the decrease in plasma glucose following the intake of sea snake lipids could be related to a corresponding increase in leptin and adiponectin level. 相似文献
993.
Taiji Nakano Akira Nakajima Hiroto Watanabe Ayaka Osada Yasuhiro Namura Takayuki Yoneyama Eiji Tanaka Mitsuru Motoyoshi 《The Angle orthodontist》2021,91(5):656
ObjectivesTo examine the torque moment that occurs between esthetic brackets and bendable alloy (stainless steel [SS], titanium-molybdenum [Ti-Mo], and titanium-niobium [Ti-Nb]) wires.Materials and MethodsThis study examined ceramic (CR), zirconium oxide (ZC), polycarbonate (PC), and conventional metallic brackets (MT) (upper, 0.018-inch and 0.022-inch slots) combined with SS, Ti-Mo, and Ti-Nb wires using elastic module ligation. The torque moments delivered by various wire and bracket combinations were measured using a torque gauge apparatus. The wire torque angles at 5–40° were examined.ResultsThe torque value increased in the order of CR, ZC, MT, and PC brackets for both 0.018-inch and 0.022-inch slots. The fracture points of the CR and ZC brackets combined with SS and Ti-Mo wires were approximately more than 30° and 35°, respectively. No fracture points were detected in the combination of ZC brackets and Ti-Nb wires.ConclusionsThe current study identified the material characteristics of CR, ZR, and PC brackets during torque tooth movements. The present results demonstrate a characteristic combined effect between different esthetic brackets and bendable alloy wires. 相似文献
994.
The Outcome of Gastrointestinal Stromal Tumors (GISTs) After a Surgical Resection in Our Institute 总被引:1,自引:1,他引:0
PURPOSE: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract arising from Cajal's cells and expressing c-kit. In a consensus report, the clinical behavior of GISTs was categorized into risk classes according to the tumor size and mitotic count. We analyzed the risk categories based on GIST patients who underwent a surgical resection at our institute during a period of 15 years. METHODS: We evaluated the risk categories of GISTs and analyzed the outcome and risk categories retrospectively. We presented the MIB-1 score of the tumor instead of mitotic counts for the evaluation of cellular growth because of inaccuracies regarding the mitotic counts. RESULTS: Patients were classified into 4 cases of very low risk, 11 of low risk, 8 of intermediate risk, and 5 of high risk. Four high-risk patients showed recurrence as either liver metastasis or peritoneal dissemination. In addition, local recurrence occurred in one low-risk and one intermediate-risk patient each. CONCLUSION: Our cases confirmed the correlation between the risk categories and the prognosis. A complete resection with sufficient margin must be confirmed even in low-risk cases to prevent local recurrence. Since high-risk patients showed poor prognosis, the adjuvant treatment with chemotherapeutic regimens must therefore be further studied for high-risk patients. 相似文献
995.
Sahin FP Yamashita H Guo Y Terasaka K Kondo T Yamamoto Y Shimada H Fujita M Kawasaki T Sakai E Tanaka T Goda Y Mizukami H 《Biological & pharmaceutical bulletin》2007,30(7):1265-1270
Internal transcribed spacer (ITS) regions of nuclear ribosomal RNA gene were amplified from 23 plant- and herbarium specimens belonging to eight Plantago species (P. asiatica, P. depressa, P. major, P. erosa, P. hostifolia, P. camtschatica, P. virginica and P. lanceolata). Sequence comparison indicated that these Plantago species could be identified based on the sequence type of the ITS locus. Sequence analysis of the ITS regions amplified from the crude drug Plantago Herb obtained in the markets indicated that all the drugs from Japan were derived from P. asiatica whereas the samples obtained in China were originated from various Plantago species including P. asiatica, P. depressa, P. major and P. erosa. 相似文献
996.
The fast and precise neuron-to-neuron signalling at the synapses is one of the most crucial processes in the central nervous system (CNS) function. Recent advances in the functional and morphological analysis of the brain synapses have identified adenosine 5'-triphosphate (ATP), a ubiquitous and most important molecule in the intracellular functions, to play important roles also as an extracellular messenger at synapses. Lines of evidence accumulated until today indicate that ATP (1) is released into the extracellular space particularly from astrocytes through specific mechanisms, (2) activates specific receptors for extracellular ATP, which modifies synaptic transmission, and (3) is hydrolysed to adenosine by ecto-nucleotidases, which in turn activates specific adenosine receptors modulating synaptic transmission. We have recently shown, using the patch-clamp recording of postsynaptic membrane currents in the acute brain slice preparations in vitro, that (1) ATP activates ATP-gated Ca2+ -permeable channels (P2X receptor channels) on presynaptic terminal membrane, triggering glutamate release without action potential, and (2) adenosine, produced from ATP in the extracellular milieu, activates presynaptic G protein-coupled receptors, which reduces Ca2+ entry through voltage-dependent Ca2+ channels and suppresses action potential-dependent transmitter release. These distinct mechanisms operate in synergy in various CNS structures and form the "purinergic regulatory complex" of the synaptic transmission. 相似文献
997.
Burioka N Fukuoka Y Takata M Endo M Miyata M Chikumi H Tomita K Kodani M Touge H Takeda K Sumikawa T Yamaguchi K Ueda Y Nakazaki H Suyama H Yamasaki A Sano H Igishi T Shimizu E 《Journal of pharmacological sciences》2007,103(2):144-149
Bronchial asthma is a chronic inflammatory disorder of the airways, in which inflammation causes bronchial hyper-responsiveness and flow limitation in the presence of various stimuli. Pulmonary function in asthmatic patients frequently deteriorates between midnight and early morning, which has suggested a role for chronotherapy. Although relationships between bronchial asthma and the function of clock genes remain unclear, some medications given for asthma such as glucocorticoids or beta(2)-adrenoceptor agonists may influence clock genes in vivo. In our studies of clock gene mRNA expressions in human bronchial epithelial cells in vitro and peripheral blood cells in vivo, we demonstrated that glucocorticoid or beta(2)-adrenoceptor agonist treatment strongly induced human Per1 mRNA expression both in vitro and in vivo. Human peripheral blood cells provide a useful indication of peripheral clock gene mRNA expression in vivo. 相似文献
998.
Okamoto E Nakamura M Akasaka Y Inoue Y Abe Y Chinzei T Saito I Isoyama T Mochizuki S Imachi K Mitamura Y 《Artificial organs》2007,31(7):538-541
We have developed internal battery systems for driving an undulation pump ventricular assist device using two kinds of lithium ion rechargeable batteries. The lithium ion rechargeable batteries have high energy density, long life, and no memory effect; however, rise in temperature of the lithium ion rechargeable battery is a critical issue. Evaluation of temperature rise by means of numerical estimation is required to develop an internal battery system. Temperature of the lithium ion rechargeable batteries is determined by ohmic loss due to internal resistance, chemical loss due to chemical reaction, and heat release. Measurement results of internal resistance (R(cell)) at an ambient temperature of 37 degrees C were 0.1 Omega in the lithium ion (Li-ion) battery and 0.03 Omega in the lithium polymer (Li-po) battery. Entropy change (DeltaS) of each battery, which leads to chemical loss, was -1.6 to -61.1 J/(mol.K) in the Li-ion battery and -9.6 to -67.5 J/(mol.K) in the Li-po battery depending on state of charge (SOC). Temperature of each lithium ion rechargeable battery under a discharge current of 1 A was estimated by finite element method heat transfer analysis at an ambient temperature of 37 degrees C configuring with measured R(cell) and measured DeltaS in each SOC. Results of estimation of time-course change in the surface temperature of each battery coincided with results of measurement results, and the success of the estimation will greatly contribute to the development of an internal battery system using lithium ion rechargeable batteries. 相似文献
999.
Takahashi T Senbokuya N Horikoshi T Sato E Nukui H Kinouchi H 《No shinkei geka. Neurological surgery》2007,35(8):799-806
Spontaneous intracranial hypotension (SIH) is reported to cause chronic subdurai hematoma (SDH), however diagnosis of SIH in patients with SDH is not always easy. We report a case of chronic SDH refractory to repeated drainage, which was attributed to SIH. A forty-five-year-old man who had been suffering from orthostatic headache for one month was admitted to our hospital presenting with unconsciousness and hemiparesis. CT on admission revealed a chronic subdural hematoma, which was successfully treated once with subdural drainage. However, the patient fell into unconscious again with recurrence of the hematoma within several days. After two more sessions of drainage, SIH due to cerebrospinal fluid leakage was diagnosed with spinal magnetic resonance imaging (MRI) and radionuclide cisternography. Spinal MRI demonstrated abnormal fluid accumulation in the thoracic epidural space, and the radionuclide cisternogram showed early excretion of tracer into urine as well as absence of intracranial tracer filling. After treatment with epidural blood patching, the hematoma rapidly disappeared and he was discharged without symptoms. In the treatment of chronic SDH, especially in young to middle aged patient without preceding trauma or hematological disorders, physicians should pay attention to underlying SIH to avoid multiple surgery. MRI of the spine as well as radionuclide cisternography is useful in evaluation of this condition. 相似文献
1000.
Several viruses have been demonstrated to be the etiologic agent in chronic progressive diseases, associated with persistence; however, major questions concerning the pathogenic mechanisms of viral persistence are still unanswered. With the aim of identifying host cellular proteins that may play a role in viral replication, we established long-term persistently infected human glioblastoma cell lines with mutant measles virus (MV) and analyzed the host proteins by two-dimensional gel electrophoresis (2-DE) with mass spectrometry. We observed significant down-modulation in the expression of mitochondrial short chain enoyl-CoA hydratase (ECHS), which catalyzes the beta-oxidation pathway of fatty acid. Knockdown of this gene by a short interference RNA (siRNA) apparently impaired wild-type MV replication and the cytopathic effects (CPEs) of MV were significantly reduced in siRNA-transfected cells. These findings will shed light upon a new important notion for the interaction between virus replication and lipid metabolism in host cells and might provide a new strategy for virus control. 相似文献