全文获取类型
收费全文 | 10529篇 |
免费 | 383篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 212篇 |
儿科学 | 202篇 |
妇产科学 | 117篇 |
基础医学 | 1285篇 |
口腔科学 | 143篇 |
临床医学 | 772篇 |
内科学 | 2523篇 |
皮肤病学 | 101篇 |
神经病学 | 682篇 |
特种医学 | 482篇 |
外科学 | 1837篇 |
综合类 | 31篇 |
预防医学 | 294篇 |
眼科学 | 340篇 |
药学 | 673篇 |
中国医学 | 29篇 |
肿瘤学 | 1247篇 |
出版年
2023年 | 34篇 |
2022年 | 92篇 |
2021年 | 146篇 |
2020年 | 66篇 |
2019年 | 92篇 |
2018年 | 136篇 |
2017年 | 118篇 |
2016年 | 155篇 |
2015年 | 157篇 |
2014年 | 236篇 |
2013年 | 338篇 |
2012年 | 537篇 |
2011年 | 650篇 |
2010年 | 375篇 |
2009年 | 354篇 |
2008年 | 638篇 |
2007年 | 709篇 |
2006年 | 669篇 |
2005年 | 718篇 |
2004年 | 769篇 |
2003年 | 754篇 |
2002年 | 755篇 |
2001年 | 175篇 |
2000年 | 183篇 |
1999年 | 171篇 |
1998年 | 176篇 |
1997年 | 144篇 |
1996年 | 140篇 |
1995年 | 126篇 |
1994年 | 112篇 |
1993年 | 124篇 |
1992年 | 122篇 |
1991年 | 131篇 |
1990年 | 120篇 |
1989年 | 88篇 |
1988年 | 79篇 |
1987年 | 75篇 |
1986年 | 46篇 |
1985年 | 60篇 |
1984年 | 45篇 |
1983年 | 26篇 |
1982年 | 26篇 |
1981年 | 24篇 |
1980年 | 37篇 |
1979年 | 34篇 |
1978年 | 31篇 |
1977年 | 20篇 |
1973年 | 14篇 |
1971年 | 15篇 |
1970年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Itsuko Okuda Hiromi Yamase Shigeru Ogawa Harushi Udagawa Tadasu Kohno 《General thoracic and cardiovascular surgery》2009,57(7):369-375
Objective The tracheobronchial structures were evaluated by multidetector-row computed tomography (MDCT), which provided imaging information
for one-lung anesthesia during thoracic surgery.
Methods The subjects consisted of 100 patients. Three-dimensional (3D) images of the tracheobronchial structures and the bronchial
tubes were created.
Results Individual differences were found in the tracheobronchial structures in 100 patients. The length and the diameter of the right
main bronchus were measured with 3D images and were not related to the patient’s physical appearance, such as body height.
Problematic intubation cases included a short right main bronchus <10 mm, an anomaly of the right bronchus, and tracheal stenosis.
Conclusion The 3D images demonstrated problematic areas of the tracheobronchial structure and helped the anesthesiologists select the
most appropriate bronchial tube suitable for the tracheobronchial structure variations. Therefore, this technique is considered
to contribute to safer performance of one-lung anesthesia.
Presented at the 60th Annual Scientific Meeting of the Japanese Association for Thoracic Surgery. 相似文献
992.
Shigeru Kotake Yuki Nanke Manabu Kawamoto Toru Yago Nobuyuki Udagawa Naomi Ichikawa Tsuyoshi Kobashigawa Seiji Saito Shigeki Momohara Naoyuki Kamatani Hisashi Yamanaka 《BONE》2009,45(4):627-639
Synovial tissues of patients with rheumatoid arthritis (RA) include factors regulating bone resorption, such as receptor activator NF-κB ligand (RANKL), TNFα, IL-6, IL-17 and IFNγ. However, in addition to these cytokines, other factors expressed in synovial tissues may play a role in resorbing bone. Here, our objective was to identify novel proteins expressed in synovial tissues of RA that regulate human osteoclastogenesis. Proteins were purified from synovial tissues of patients with RA, using gel filtration chromatography, ion-exchange chromatography, reverse-aspect HPLC, and mass spectrometry. We evaluated the effects of the purified fractions on human osteoclastogenesis induced by RANKL and M-CSF. We determined the amino acid sequences showing inhibitory activity on human osteoclastogenesis. In addition, we synthesized novel peptides from the molecule including the amino acid sequences. Then, we evaluated the effects of the peptides and antibodies against the molecule on human osteoclastogenesis from monocytes and mature osteoclasts, and on pit formation by mature osteoclasts using OsteologicR discs. We examined the effect of the peptide on the expression of both mRNA and protein of NFATc1. We also examined the effect of RANKL on the expression of mRNA of the molecule on osteoclasts and macrophages. We identified a small peptide including Gly-Gln-Asn (GQN) with inhibitory activity on human osteoclastogenesis. We then found that GQN is included in the amino acid sequence of the extra-cellular domain of TCTA protein, which is expressed ubiquitously in normal human tissues, but whose function has not been clarified. We designed novel peptides, including GQN, from the sequence of TCTA protein. One of these peptides (29-mer), but not a scrambled peptide for the 29-mer peptide, potently inhibited RANKL-induced human osteoclastogenesis. The peptide also inhibited pit formation of mature human osteoclasts and suppressed the formation of large osteoclasts in the culture of mature osteoclasts. Furthermore, polyclonal antibodies against TCTA protein suppressed the formation of large osteoclasts in the cultures of both monocytes and mature osteoclasts, supporting our hypothesis. Peptide A did not significantly inhibit the expression of both mRNA and protein of NFATc1 in osteoclasts. Our novel peptide and polyclonal antibodies against the peptide inhibited human osteoclastogenesis and the function of mature osteoclasts, preventing cellular fusion by TCTA protein and a putative counterpart molecule. 相似文献
993.
994.
995.
Motoaki Sugiura Keisuke Wakusawa Atsushi Sekiguchi Yuko Sassa Hyeonjeong Jeong Kaoru Horie Shigeru Sato Ryuta Kawashima 《Human brain mapping》2009,30(8):2676-2688
Humans extract behaviorally significant meaning from a situation by integrating meanings from multiple components of a complex daily environment. To determine the neural underpinnings of this ability, the authors performed functional magnetic resonance imaging of healthy subjects while the latter viewed naturalistic scenes of two people and an object, including a threatening situation of a person being attacked by an offender with an object. The authors used a two‐factorial design: the object was either aversive or nonaversive, and the offender's action was either directed to the person or elsewhere. This allowed the authors to examine the neural response to object aversiveness and person‐directed intention separately. A task unrelated to threat was also used to address incidental (i.e., subconscious or unintentional) detection. Assuming individual differences in incidental threat detection, the authors used a functional connectivity analysis using principal components analysis of intersubject variability. The left lateral orbitofrontal cortex and medial prefrontal cortex (MPFC) were specifically activated in response to a threatening situation. The threat‐related component of intersubject variability was extracted from these data and showed a significant correlation with personality scores. There was also a correlation between threat‐related intersubject variability and activation for object aversiveness in the left temporal pole and lateral orbitofrontal cortex; person‐directed intention in the left superior frontal gyrus; threatening situations in the left MPFC; and independently for both factors in the right MPFC. Results demonstrate independent processing of object aversiveness and person‐directed intention in the left temporal‐orbitofrontal and superior frontal networks, respectively, and their integration into situational meaning in the MPFC. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc. 相似文献
996.
Real-time endobronchial ultrasound-guided transbronchial needle aspiration is useful for diagnosing sarcoidosis 总被引:1,自引:0,他引:1
Oki M Saka H Kitagawa C Tanaka S Shimokata T Kawata Y Mori K Kajikawa S Ichihara S Moritani S 《Respirology (Carlton, Vic.)》2007,12(6):863-868
BACKGROUND AND OBJECTIVE: Several studies of real-time endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) have reported a sensitivity of approximately 90% in the diagnosis of mediastinal and hilar malignancies. However, few studies have addressed its role in the diagnosis of sarcoidosis. The aim of the present study was to assess the utility of EBUS-TBNA in confirming a pathological diagnosis of sarcoidosis. METHODS: Fifteen consecutive patients with suspected sarcoidosis and mediastinal and/or hilar lymphadenopathy were investigated prospectively. EBUS-TBNA with an echo-bronchoscope and a dedicated echogenic 22-gauge needle was carried out in patients under conscious sedation, followed by conventional TBNA of the same lesion using a 19-gauge needle. RESULTS: EBUS-TBNA and/or TBNA demonstrated non-caseating epithelioid cell granulomas in 14 of 15 patients (93%). All 14 patients with a pathological diagnosis of sarcoidosis were considered to have sarcoidosis based on subsequent clinical assessments. The single patient with a negative EBUS-TBNA and TBNA had a malignant melanoma diagnosed following surgical biopsy. EBUS-TBNA confirmed a diagnosis of sarcoidosis in 13 of the 14 patients (93%) by identifying non-caseating epithelioid cell granulomas in 18 of 23 lymph nodes (78%) sampled. When two needle aspirates of one or two lymph nodes were carried out, the percentage positive pathological diagnosis for sarcoidosis for (i) EBUS-TBNA; (ii) TBNA; and (iii) the combination of EBUS-TBNA and TBNA were 93% (13 of 14 patients), 93% (13 of 14 patients) and 100% (14 of 14 patients), respectively. There were no complications associated with the procedures. CONCLUSION: EBUS-TBNA is less invasive and acceptably sensitive as a method for obtaining pathological confirmation of sarcoidosis. 相似文献
997.
Chin S Isomoto H Mizuta Y Wen CY Shikuwa S Kohno S 《World journal of gastroenterology : WJG》2007,13(11):1752-1754
A 62-year-old man presented with upper abdominal discomfort underwent upper gastrointestinal endoscopy. Gastroscopy and endoscopic ultrasonography revealed a submucosal tumor (SMT) with homogenous echogenicity originated from extragastric organs. An abdominal contrast-enhanced computed tomography (CT) showed that the well-marginated ovoid mass, approximately 6 cm in diameter, enhanced homogenously to a similar degree as splenic parenchyma. 99mTechnetium sulfur colloid scintigraphy revealed the splenic nature of the mass. A diagnosis of accessory spleen mimicking gastric SMT was made. Subsequent follow-up was uneventful without performing splenectomy. 相似文献
998.
999.
With device improvements, more total occlusions have been crossed with a guidewire and balloon. However, true intraluminal/intrastent passage is not always accessed, which is not apparent on coronary angiography. In this study, using intravascular ultrasound as well as computed tomography, we demonstrated a crushed stent previously implanted outside the sirolimus-eluting stent, which resulted from subintimal (outside the stent) passage of a guidewire. 相似文献
1000.
Yatoh S Akashi T Chan PP Kaneto H Sharma A Bonner-Weir S Weir GC 《Diabetes/metabolism research and reviews》2007,23(3):239-249
BACKGROUND: Our goal was to convert adult mouse hepatocytes to pancreatic beta-cells. METHODS AND RESULTS: To facilitate conversion, cultured primary hepatocytes were dedifferentiated by the removal of dexamethasone (Dex) from the culture media. Removal of Dex caused detachment of hepatocytes from the culture dish, but the addition of betacellulin prevented this from happening. With the combination of lack of Dex and addition of betacellulin, albumin mRNA levels decreased. Cultured hepatocytes had a faint expression of insulin 2 mRNA, Nkx 6.1 and Pax 6 mRNA. Dedifferentiated hepatocytes were transduced with adenoviruses expressing NeuroD1, Ngn 3, or Pax 4. NeuroD1 transduction increased the insulin 2 mRNA but caused detachment of cells. However, when hepatocytes were allowed to reaggregate for 4 and 6 days in hydrophobic plates after transduction with NeuroD1, further increases of insulin 2 mRNA were found along with induction of PDX-1, IAPP, NeuroD1, Ngn3, Pax 4, Isl-1, PC1, PC2 and islet glucokinase. Additionally, glucagon, pancreatic polypeptide and somatostatin expression were induced, but neither elastase 1 nor insulin 1 mRNA could be detected. Ngn 3 and Pax 4 had effects similar to NeuroD1, but did not increase insulin 2 mRNA as much as NeuroD1. CONCLUSION: We conclude that the combination of NeuroD1 and reaggregation promotes cultured dedifferentiated hepatocytes to differentiate towards a pancreatic beta-cell phenotype. 相似文献