全文获取类型
收费全文 | 634篇 |
免费 | 33篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 20篇 |
妇产科学 | 5篇 |
基础医学 | 120篇 |
口腔科学 | 16篇 |
临床医学 | 54篇 |
内科学 | 142篇 |
皮肤病学 | 23篇 |
神经病学 | 20篇 |
特种医学 | 17篇 |
外科学 | 93篇 |
综合类 | 4篇 |
预防医学 | 9篇 |
眼科学 | 14篇 |
药学 | 70篇 |
中国医学 | 2篇 |
肿瘤学 | 57篇 |
出版年
2022年 | 7篇 |
2021年 | 12篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 27篇 |
2011年 | 26篇 |
2010年 | 26篇 |
2009年 | 28篇 |
2008年 | 23篇 |
2007年 | 30篇 |
2006年 | 41篇 |
2005年 | 32篇 |
2004年 | 32篇 |
2003年 | 36篇 |
2002年 | 33篇 |
2001年 | 11篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 20篇 |
1997年 | 16篇 |
1996年 | 17篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1993年 | 11篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1959年 | 3篇 |
1958年 | 8篇 |
1957年 | 12篇 |
1956年 | 12篇 |
1955年 | 7篇 |
1954年 | 6篇 |
排序方式: 共有668条查询结果,搜索用时 15 毫秒
41.
Summary Blood flow in active skeletal muscles provides energy substrate, oxygen and reduction of excessive heat and metabolic by-products. Although cyclic jaw motions such as those during mastication and speech articulation are the primitive oro-facial functions, possible effects of the cyclic muscle contractions on the intramuscular haemodynamics of the jaw muscles remains scarcely known. We investigated the masseteric haemodynamics during and after gum-chewing. Ten healthy female adults participated in the study. Electromyography, kinetics of masseter muscle oxygenation, electrocardiogram and blood pressure were recorded simultaneously. The subjects were asked to perform gum-chewing and cyclic jaw motion without gum bolus (empty-chewing task). The haemodynamics parameters were compared between the two experimental conditions. During gum-chewing task, deoxygenated haemoglobin and sympathetic nerve activity increased, while tissue blood oxygen saturation decreased. Blood pressure and parasympathetic nerve activity did not change. The overall behaviour of haemodynamic parameters during empty-chewing task was similar to that observed during gum-chewing task. However, the latency periods from the end of chewing until significant changes in the haemodynamic parameters were notably shorter ( P < 0·05) in gum-chewing task as compared with those associated with empty-chewing task. The duration of the changes was shorter with empty-chewing than with gum-chewing. Fluctuations in masseter muscle haemodynamics associated with chewing jaw movement differed depending on the level of muscle contraction during movement. The differences became statistically significant immediately after the commencement of chewing and after the cessation movement. During the chewing movement, automatic nerve activities increased in response to the level of muscle contraction during movement. 相似文献
42.
HIROYUKI ABE TAIJI NISHIMURA TAKAFUMI MIURA TAKUSHI UCHIKOBA TOMOYASU OHNO NORIYUKI ISHIKAWA KIMIYOSHI YOKOI YOSHIHARU OHAKI 《International journal of urology》2002,9(10):599-601
BACKGROUND: We report here an extremely rare case of cystosarcoma phyllodes of the seminal vesicle. METHODS: A 65-year-old man presented with urinary hesitancy, frequency and constipation. Clinical examinations including two needle biopsies were performed, and the patient had undergone open surgery. RESULTS: The final pathological diagnosis was cystosarcoma phyllodes of the seminal vesicle. Seven months after the operation, a chest X-ray showed lung metastasis, and the patient died 11 months after the operation. CONCLUSION: To our knowledge, only one case of cystosarcoma phyllodes of the seminal vesicle has been previously reported. 相似文献
43.
Takao UCHIDA Koichi MAKIMURA Katsuhito ISHIHARA Hideaki GOTO Yoshito TAJIRI Mariko OKUMA Ryuichi FUJISAKI Katsuhisa UCHIDA Sigeru ABE Masafumi IIJIMA 《The Journal of dermatology》2009,36(4):202-208
The positive rates of dermatophytes isolated and identified by conventional methods are rather low. Moreover, clinical isolates sometimes show atypical morphology, and in such cases microscopic methods are not applicable for identification. The present study was performed to assess the utility of specific polymerase chain reaction (PCR)-based methods for Trichophyton rubrum and Trichophyton mentagrophytes as diagnostic tools for dermatophytoses. Both conventional morphological identification and specific PCR methods based on the nuclear ribosomal internal transcribed spacer (ITS)1 DNA sequence were performed to identify dermatophyte species from clinical specimens of patients who visited Kawasaki Social Insurance Hospital between 16 May and 17 August 2005. Specific PCR methods were also directly applied to clinical specimens, and the results of the two methods were compared. The clinical samples examined consisted of 126 skin scale specimens and 80 nail specimens. The positive rates of culture isolation from clinical specimens were 67% and 33% for skin scale and nail specimens, respectively. In contrast, PCR analysis yielded a positive rate of 100% for clinical isolates from both skin scales and nails, and rates of 95% and 99% were obtained by direct application to clinical specimens. The results of the present study indicated that specific PCR is highly advantageous as a diagnostic tool for detection and identification of dermatophytes on direct application to skin scale or nail specimens. 相似文献
44.
Junji Yoshino Saburo Nakazawa Kazuo Inui Yoshimichi Katoh Takao Wwkabayashi Kazumu Okushima Takashi Kobayashi Yuta Nakamura Shinya Watanabe Naoko Asakura 《Digestive endoscopy》2000,12(3):233-236
Background: The normal gastric wall has been reported to appear to be a five‐layered structure. The structure of the gastric wall using a 30 MHz endoscopic ultrasound probe and especially the identification of the muscularis mucosae (MM), has not been analyzed clearly. Methods: In a basic study, 11 sections of normal gastric wall with 26 horizontally inserted nylon sutures were immersed in water. The sections were scanned and the findings correlated using standard histology. In a clinical study, 15 early gastric cancers were examined by a 30 MHz endoscopic ultrasound probe. Results: In a basic study, layers deeper than the lower part of the submucosa could not be seen using ultrasonography. The first to fourth layers represented the mucosal layer except the MM, the fifth layer (high‐echo layer) represented the boundary echo and a part of the MM, while the sixth layer (low‐echo layer) represented the rest of the MM. The muscularis mucosae was seen clearly in all samples. In a clinical study the layers deeper than the submucosal layer could not be seen and the MM was visible in 87% of cases. The depth of invasion was estimated accurately in 90% of mucosal cancers and in 80% of submucosal cancers. Conclusion: A 30 MHz endoscopic ultrasound probe, which cannot image the entire gastric wall, can visualize the MM and may help to confirm the structure of gastric wall layers and improve the ability to determine the depth of invasion in gastric cancer. 相似文献
45.
Takahiko Sakamoto Goki Matsumura Yoshimichi Kosaka Yusuke Iwata Noboru Yamamoto Satoshi Saito Kazuaki Ishihara Hiromi Kurosawa 《European journal of cardio-thoracic surgery》2008,34(1):37-41
OBJECTIVE: The current study aims to evaluate the long-term outcomes of the Konno procedure. METHODS: The clinical records of 63 patients who had undergone the Konno procedure between February 1984 and March 2007 were reviewed. During this period, the Ross procedure was introduced in 1996. Of the 63 patients, 38 were male and 25, female. Their ages at the time of operation ranged from 1 year 9 months to 37 years, and their body weights ranged from 8.1 to 63 kg. Valves larger than 23 mm were used in 57 patients. RESULTS: There was one hospital death (myocardial infarction) and six late deaths (sudden death, 2; congestive heart failure, 2; infectious endocarditis, 1; traffic accident, 1). The Kaplan-Meier survival rates including hospital mortality and late mortality were 91.9% at 10 years and 87.7% at 15 years. There were 20 significant complications in 16 patients: thromboembolism was noted in 1 patient; reoperations (Konno procedure (aortic valve replacement), 5 (thrombosed valve, 3; pannus formation, 1; IE, 1); mitral valve replacement, 3; coronary artery bypass grafting, 2; grafting of the descending aorta, 1), balloon dilatation for recoarctation, and 7 catheter interventions were required in 9, 1, and 5 patients, respectively. The event-free rates including all events were 75.2% at 10 years and 67.2% at 15 years. In the long-term period, the results of echocardiography revealed good cardiac function. CONCLUSIONS: The Konno procedure is effective and safe for the treatment of complex left ventricular outflow tract obstruction and for the preservation of ventricular function. Since some issues concerning anticoagulation-related complications and infectious endocarditis remain, careful observation is mandatory. 相似文献
46.
47.
Aya Hotta Young Chul Kim Eri Nakamura Yoshihiko Kito Yoshimichi Yamamoto Hikaru Suzuki 《Journal of Smooth Muscle Research》2005,41(6):313-327
In circular smooth muscle bundles isolated from the guinea-pig stomach antrum, the effects of quinidine, Ni2+, flufenamic acid, niflumic acid, La3+, SKF-96365 and 4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) on acetylcholine (ACh)-induced depolarization were investigated. Recording membrane potentials from smooth muscle cells with intracellular microelectrodes revealed that ACh (1 microM) depolarized the membrane by 5-8 mV and increased the amplitude and frequency of slow potentials. These effects were inhibited by atropine. Quinidine (10 microM) increased the amplitude of ACh-induced depolarization, with no alteration to the properties of slow potentials. Ni2+ (50 microM) transiently (5-10 min) depolarized the membrane by about 5 mV, with an associated increase in frequency and amplitude of slow potentials. In the stabilized condition with Ni2+, the amplitude of ACh-induced depolarization remained unchanged. Flufenamic acid (10 microM) inhibited the generation of slow potentials, with no change in either the amplitude of ACh-induced depolarization or of the amplitude and frequency of slow potentials generated during ACh stimulation. A high concentration of flufenamic acid (100 microM) depolarized the membrane and increased the amplitude of ACh-induced depolarization. Niflumic acid (10 microM) hyperpolarized the membrane and increased the amplitude and frequency of slow potentials and also the amplitude of ACh-induced depolarization. DIDS (100 microM) hyperpolarized the membrane and inhibited the amplitude and frequency of slow potentials, with no alteration to the amplitude of ACh-induced depolarization. SKF-96365 (3-50 microM) depolarized the membrane in a concentration-dependent manner, but did not change the level of ACh-induced depolarization. La3+ (50 microM) did not alter the properties of the slow potentials or the ACh-induced responses. These results provide evidence that ACh-induced depolarization is not inhibited by chemicals known to inhibit non-selective cation channels. We suggest that muscarinic receptor-mediated signal transduction may be different in smooth muscle and interstitial cells. 相似文献
48.
49.
Toyobuku H Sai Y Kagami T Tamai I Tsuji A 《The Journal of pharmacology and experimental therapeutics》2003,305(1):40-47
The feasibility of using adenovirus-mediated human oligopeptide transporter (hPEPT1) gene transfer to achieve peptide drug delivery to the brain across the blood-brain barrier was tested by examining the accumulation of model peptides in a rat brain endothelial cell line (RBEC1) and rat brain after transduction with a recombinant adenovirus encoding hPEPT1-enhanced yellow fluorescent protein fusion gene (AdhPEPT1-EYFP). In vitro uptake of [(3)H]GlySar was determined in RBEC1 transduced with AdhPEPT1-EYFP. In vivo, the accumulation of cefadroxil in rat brain was evaluated after transduction of AdhPEPT1-EYFP. At pH 6.0, the uptake of [(3)H]GlySar by RBEC1 transduced with AdhPEPT1-EYFP was increased 4-fold compared with that of nontransduced cells. At pH 7.4, uptake of [(3)H]GlySar in AdhPEPT1-EYFP transduced RBEC1 was 1.5 times higher than that of nontransduced cells. Unlabeled glycylsarcosine (10 mM) reduced the uptake of [(3)H]GlySar to a level comparable with that of nontransduced cells. At 30 min after intravenous administration of cefadroxil to rats transduced with AdhPEPT1-EYFP at 3.2 x 10(9) plaque-forming units/rat by an in situ brain perfusion method, the brain-to-plasma concentration ratio (Kp) of cefadroxil was increased about 2 times compared with that of nontransduced or AdGFP (control vector)-transduced rats, although this was not statistically significant. In contrast, Kp of [(14)C]inulin, a marker for extracellular fluid space, remained unchanged after adenoviral transduction. In conclusion, our results suggest that adenovirus-mediated heterologous expression of hPEPT1 in vivo could be a useful approach to deliver oligopeptides to the brain. 相似文献
50.
RITSUKO KOHNO M.D. HARUHIKO ABE M.D. F.A.C.C. YASUSHI OGINOSAWA M.D. TOSHIHISA NAGATOMO M.D. YUTAKA OTSUJI M.D. F.A.C.C 《Pacing and clinical electrophysiology : PACE》2007,30(S1):S203-S206
The treatment of severe orthostatic hypotension (OH) is currently unsatisfactory and usually includes various pharmaceuticals to expand the blood volume and promote peripheral vasoconstriction. This study examined the short- and intermediate-term effects of atrial tachypacing (ATP) in patients with severe OH. We implanted dual chamber pacemakers in five patients (mean age 64 ± 7 years; four men), presenting with drug refractory, recurrent syncope, and OH due to panautonomic failure with severe chronotropic incompetence and absence of rate acceleration upon assuming the upright posture. The blood pressure (BP) was measured in the supine and passive upright postures, during sinus rhythm, and during atrial pacing at 90, 100, and 110 ppm, at 1 week and at discharge and/or 3 months after pacemaker implantation. Alleviation of symptoms and a delay in the fall in upright BP were observed in a single patient at 1 week, while at discharge and/or 3 months, all patients were markedly improved. The mean fall in systolic/diastolic BP between supine and upright position decreased from 73 ± 17/46 ± 13 mmHg before, to 56 ± 27/41 ± 30 mmHg during ATP. Although these changes did not reach statistical significance, the time required for the fall in BP lengthened significantly from 2.1 ± 0.2 minutes during sinus rhythm to 9.3 ± 1.5 minutes during ATP (P < 0.001).
Conclusions: At discharge and/or 3 months of follow-up, ATP conferred beneficial effects on orthostatic BP and alleviated symptoms in patients with severe OH. The short-term effects of ATP did not reflect its longer-term effects in four of the five patients. 相似文献
Conclusions: At discharge and/or 3 months of follow-up, ATP conferred beneficial effects on orthostatic BP and alleviated symptoms in patients with severe OH. The short-term effects of ATP did not reflect its longer-term effects in four of the five patients. 相似文献