全文获取类型
收费全文 | 9675篇 |
免费 | 468篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 115篇 |
儿科学 | 247篇 |
妇产科学 | 104篇 |
基础医学 | 1027篇 |
口腔科学 | 198篇 |
临床医学 | 764篇 |
内科学 | 3053篇 |
皮肤病学 | 110篇 |
神经病学 | 666篇 |
特种医学 | 266篇 |
外科学 | 1509篇 |
综合类 | 41篇 |
预防医学 | 248篇 |
眼科学 | 97篇 |
药学 | 856篇 |
中国医学 | 15篇 |
肿瘤学 | 903篇 |
出版年
2023年 | 65篇 |
2022年 | 118篇 |
2021年 | 230篇 |
2020年 | 109篇 |
2019年 | 153篇 |
2018年 | 248篇 |
2017年 | 178篇 |
2016年 | 190篇 |
2015年 | 226篇 |
2014年 | 255篇 |
2013年 | 332篇 |
2012年 | 503篇 |
2011年 | 626篇 |
2010年 | 333篇 |
2009年 | 269篇 |
2008年 | 482篇 |
2007年 | 531篇 |
2006年 | 534篇 |
2005年 | 474篇 |
2004年 | 544篇 |
2003年 | 495篇 |
2002年 | 514篇 |
2001年 | 224篇 |
2000年 | 225篇 |
1999年 | 213篇 |
1998年 | 117篇 |
1997年 | 109篇 |
1996年 | 89篇 |
1995年 | 75篇 |
1994年 | 83篇 |
1993年 | 48篇 |
1992年 | 136篇 |
1991年 | 138篇 |
1990年 | 127篇 |
1989年 | 122篇 |
1988年 | 107篇 |
1987年 | 110篇 |
1986年 | 89篇 |
1985年 | 95篇 |
1984年 | 62篇 |
1983年 | 67篇 |
1981年 | 36篇 |
1980年 | 33篇 |
1979年 | 70篇 |
1978年 | 41篇 |
1977年 | 42篇 |
1974年 | 30篇 |
1971年 | 36篇 |
1970年 | 32篇 |
1969年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
1.
Mitsuhiro Tozaki Kunihiko Fukuda Masafumi Suzuki 《Magnetic resonance in medical sciences》2006,5(3):137-146
PURPOSE: The purpose of this study was to assess the relationship between the amount of scirrhous component in invasive ductal carcinoma and its MR characteristics. MATERIALS AND METHODS: We retrospectively reviewed 71 consecutive patients with invasive ductal carcinoma smaller than 25 mm (average, 16.6 mm) in diameter. The scirrhous component was defined as invasive foci in small clusters of cancer cells showing desmoplasia. Invasive ductal carcinoma was subclassified into 3 groups in accordance with the amount of the scirrhous component (scirrhous component degree; SCD): SCD I (scirrhous component less than 20%), SCD II (intermediate), and SCD III (more than 80%). Dynamic magnetic resonance (MR) imaging was performed using volumetric interpolated sequence. Prior to dynamic study, T2*-weighted first-pass perfusion images were obtained before, during, and after bolus injection of 0.1 mmol Gd-DTPA/kg. RESULTS: Twenty-eight lesions were classified as SCD I, 14 as SCD II, and 29 as SCD III. Mass margin and signal intensity loss in the perfusion study were significantly different among the 3 SCD groups (P<0.001). The kinetic patterns were significantly different among the 3 SCD groups (P=0.04), and between SCD I/II and SCD III (P=0.03). The presence of enhancing internal septations was significantly different between SCD I/II and SCD III carcinomas (P=0.05). Central enhancement was only observed in SCD I carcinoma (4%; 3/71). CONCLUSION: The histological predominance of the scirrhous component in invasive ductal carcinoma may be one explanation for the differences in morphologic and kinetic patterns on MR imaging. 相似文献
2.
Peter Chiba Barbara Tell Walter Jger Elisabeth Richter Manuela Hitzlera Gerhard Ecker 《Archiv der Pharmazie》1997,330(11):343-347
A series of 5-hydroxy and 5-benzyloxy analogs of the antiarrhythmic and multidrug resistance (MDR) modulating drug propafenone was synthesized and the MDR-modulating activity of the compounds was evaluated using a daunomycin efflux assay system. The key step of the synthesis is the selective reduction of the double bond in 1 without cleavage of the benzyl group thus leading to the phenol 3 . Alkylation with epichlorohydrine followed by nucleophilic epoxide ring opening gave the benzylated target compounds 5a–d . Subsequent cleavage of the benzyl group gave the 5-hydroxy analogs 6a–d . Structure activity relationship studies showed, that the 5-hydroxy derivates 6a–d fit the log P/log potency correlation line previously established for a series of propafenone analogs. In contrast, all four 5-benzyloxy analogs 5a–d showed almost identical EC50 values, independent of their log P value. 相似文献
3.
Acute Immobilization Stress and Intraventricular Injection of CRF Suppress Naloxone-Induced LH Release in Ovariectomized Estrogen-Primed Rats 总被引:1,自引:0,他引:1
Tatsuo Akema Atsuhiko Chiba Reiji Shinozaki Morihiro Oshida Fukuko Kimura & Jun-ichi Toyoda 《Journal of neuroendocrinology》1996,8(8):647-652
The present study was undertaken to evaluate the role and possible interaction of the endogenous opioid peptide (EOP) and corticotropin-releasing factor (CRF) in the acute stress-induced suppression of gonadotropin secretion in ovariectomized estrogen-primed rats. An intravenous (i.v.) injection of naloxone (10 or 20 mg/kg), an EOP antagonist, significantly elevated serum luteinizing hormone (LH) levels within 10 min in non-stressed animals. The naloxone-induced LH release was completely eliminated when tested 30 min after the onset of acute immobilization. In a subsequent study, it was found that suppression of the naloxone-induced LH release occurred as early as 5 min after the stress onset, and was still evident 60 min after the end of a 30-min period of immobilization. The effect of naloxone was restored 3 h after liberation of the animal from the 30-min immobilization. An intraventricular (i.c.v.) injection of CRF (1 or 5 μg) also significantly suppressed, in a dose-related manner, the effect of a subsequent i.v. injection of naloxone. However, an i.c.v. injection of α -helical CRF(9-41) (25 or 50 μg), a CRF antagonist, prior to immobilization, could not interfere with the suppressive effect of stress on naloxone-induced LH release. These results suggest that both acute immobilization stress and CRF can inhibit the LH secretory activity without mediation by EOP neurons. However, the stress-related suppression may involve non-CRF mechanism(s). 相似文献
4.
5.
M Nakanishi Y Demura S Mizuno S Ameshima Y Chiba I Miyamori H Itoh M Kitaichi T Ishizaki 《The European respiratory journal》2007,29(3):453-461
High-resolution computed tomography (HRCT) findings in patients with respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) are varied and nonspecific. There is no known report of changes in HRCT findings and respiratory function test results for RB-ILD patients following the cessation of smoking. Five patients with RB-ILD, confirmed by surgical lung biopsy, were retrospectively studied. Each stopped cigarette smoking and did not receive corticosteroid therapy after diagnosis. The clinical symptoms, respiratory function test results and HRCT findings obtained at the final observation were compared with those from the time of diagnosis. Ground-glass opacity and centrilobular nodules corresponding to pathological respiratory bronchiolitis, as well as intralobular fine linear-reticular opacity corresponding to fibrosis involving the subpleural alveolar septa, showed computed tomography-pathological correlations. Both clinical symptoms and the diffusing capacity of the lungs for carbon monoxide improved significantly following smoking cessation, as did ground-glass opacity and centrilobular nodules seen during the initial HRCT examination. Centrilobular nodules and ground-glass opacity, which are the main features of high-resolution computed tomography of respiratory bronchiolitis-associated interstitial lung disease patients and represent pathological respiratory bronchiolitis, can be improved by smoking cessation. The diffusing capacity of the lung for carbon monoxide in respiratory function tests can be also improved. 相似文献
6.
The incidence of late infection after cranioplasty was studied in 130 patients with 133 cranioplasties. The materials used were prefabricated resin in 62 cases, autogenic bone in 38, intraoperatively fashioned resin in 25, and vitallium in eight. Six infections were documented, for an infection rate of 4.5%. In addition to these six cases, we studied eight patients with infections who had undergone cranioplasty elsewhere but had the infected plates removed in our hospitals. Among the 14 cases of infection, the intervals between cranioplasty and plate removal were 3 to 43 months (average, 10.5 months). The eight patients referred from other hospitals had a significantly shorter average interval between external decompression and cranioplasty than did patients who did not develop infection (2.6 versus 6.7 months; p less than 0.005). Systemic signs were mild despite obvious local signs of infection. Of the 11 first infections, nine (82%) were associated with discharge of pus from a fistula; in these cases a galeal suture had become infected apparently through scratching by the patients. In contrast, in the three patients who had had a previous infection, the second infection manifested as subgaleal and epidural empyema or meningitis without a fistula or pus discharge. Nine infections (69%) were due to Staphylococcus. All but two patients required removal of the infected plates. One recovered with conservative therapy and one died of meningitis, giving a mortality rate of 0.8%. No matter how mild the systemic signs, late infection warrants surgical debridement and plate removal. The risk factors for late infection of cranioplasty are discussed. 相似文献
7.
Yukinori Sakao Toru Sakuragi Yuji Takeda Masafumi Natsuaki Tsuyoshi Itoh 《General thoracic and cardiovascular surgery》2003,51(10):537-540
We experienced a rare case of giant cell tumor (GCT) arising in the 5th rib involving the 5th vertebral body and transverse process. A 57-year-old man presented with a well-defined mass in the left thoracic cavity on chest x ray examination. Chest computed tomography showed a heterogeneous 7cm-diameter mass originating in the posterior segment of the left 5th rib. The tumor had spread to the 5th thoracic vertebra destroying the left half of the body and transverse process. Magnetic resonance imaging showed a heterogeneous-intensity mass involving the 4th to 6th ribs. A radical excision of the tumor followed by a 50 Gy radiotherapy was performed after embolization of the feeding arteries. The pathological diagnosis was a GCT. The patient remains well without evidence of recurrence for 6 years following surgery. The present case is only the 14th case of GCT arising in the rib to have been reported in Japan. 相似文献
8.
Mana Ichimura Koichi Hiratsuka Naomi Ogura Tadahiko Utsunomiya Hiroyuki Sakamaki Toshirou Kondoh Yoshimitsu Abiko Shigeo Otake Masafumi Yamamoto 《Journal of oral pathology & medicine》2006,35(3):167-174
BACKGROUND: To understand the immunopathological features of oral lichen planus (OLP), we analyzed the expression of chemokines in the epithelial cell layers. Methods: Epithelia from OLP or healthy gingiva were collected by laser microdissection. The chemokine and chemokine receptor expressions in the epithelia were analyzed by DNA microarray. RESULTS: High levels of MIP-3alpha/LARC/CCL20 and its receptor CCR6 were expressed in the lesional epithelia. Furthermore, DC-CK1/CCL18, ELC/CCL19, SDF-1/CXCL12 and CXCR4 expressions were also increased. Immunohistologial analysis showed that high numbers of Langerhans cells (LCs) were present in the epithelia of OLP. Lesional epithelia also expressed high levels of the ligands specific for CXCR3 (e.g. MIG/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11) and CCR5 (e.g. RANTES/CCL5). CONCLUSIONS: Infiltration of LCs is orchestrated by CCR6. Further, LCs residing in the lesional epithelia may be a mature phenotype. Moreover, infiltration of T cells in OLP could be mediated by signaling pathways through CXCR3 and CCR5. 相似文献
9.
Masafumi Kumano Hideaki Miyake Isao Hara Junya Furukawa Atsushi Takenaka Masato Fujisawa 《International journal of urology》2007,14(4):336-338
BACKGROUND: The objective of this study was to evaluate the efficacy and safety of first-line high-dose chemotherapy (HDCT) combined with peripheral blood stem cell transplantation (PBSCT) for patients with advanced extragonadal germ cell tumors (EGGCT). METHODS: Six male patients with advanced non-seminomatous EGGCT were treated with HDCT combined with PBSCT following 2-3 cycles of conventional-dose induction chemotherapy. The regimens used for HDCT were carboplatin, etoposide and ifosfamide (ICE) in five patients and ICE plus paclitaxel (T-ICE) in one patient, and that for induction therapy was cisplatin, etoposide and bleomycin (PEB) in all patients. As a rule, HDCT was continuously administered until alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin normalized (beta-HCG). RESULTS: Following 1-6 courses of HDCT (median, 4 courses), beta-HCG and AFP were normalized in all patients, and five and one patient were diagnosed as showing partial remission and stable disease, respectively. Five patients underwent surgical resection of residual tumors after HDCT, yielding necrotic tissue in two, mature teratoma in two, and viable cancer tissue in one, and the surgical margin was negative in all patients. At a median follow-up of 36 months, five patients were alive and disease-free, whereas the remaining one died of disease progression. Although all patients had grade 3 hematological toxicity, there was no treatment-related death by combining PBSCT. CONCLUSIONS: First-line HDCT with PBSCT could be safely administered to patients with advanced EGGCT, and the antitumor effect of this treatment was comparatively favorable. First-line HDCT therefore may represent an attractive option for patients with advanced EGGCT. 相似文献
10.
Masafumi Kataoka Kaori Shigemitsu Shunsuke Tanabe Toshinori Ohara Takaomi Takahata Soichiro Nose 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2005,53(7):365-368
A 67-year-old man was admitted to our hospital due to esophageal cancer. Cancer existed at the lower esophagus and subtotal esophagectomy and lymphadenectomy was performed. The postoperative course was uneventful. Pathological findings revealed moderately differentiated squamous cell carcinoma that metastasized to the abdominal lymph nodes which include the paraaortic lymph nodes. He complained of anorexia three months after the operation and was found to have multiple liver and mediastinal lymph node metastases. He was admitted for chemotherapy. Before starting chemotherapy, he suddenly died without any sign of hemorrhage or respiratory disorder. Autopsy showed metastatic lesions to the heart and mediastinal lymph nodes, liver, thoracic vertebrae, kidney, adrenal gland and heart. Metastatic nodules in the heart were on the ventricular septum where the conducting system exists. No direct invasion from the pericardium was observed. Blockade of the conducting system of the heart was considered to have caused the severe arrhythmia and sudden cardiac arrest. 相似文献