全文获取类型
收费全文 | 12134篇 |
免费 | 537篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 226篇 |
妇产科学 | 147篇 |
基础医学 | 1606篇 |
口腔科学 | 221篇 |
临床医学 | 605篇 |
内科学 | 3124篇 |
皮肤病学 | 384篇 |
神经病学 | 1168篇 |
特种医学 | 447篇 |
外科学 | 2350篇 |
综合类 | 66篇 |
预防医学 | 370篇 |
眼科学 | 101篇 |
药学 | 709篇 |
中国医学 | 37篇 |
肿瘤学 | 1156篇 |
出版年
2023年 | 66篇 |
2022年 | 115篇 |
2021年 | 170篇 |
2020年 | 107篇 |
2019年 | 140篇 |
2018年 | 182篇 |
2017年 | 156篇 |
2016年 | 178篇 |
2015年 | 209篇 |
2014年 | 277篇 |
2013年 | 353篇 |
2012年 | 537篇 |
2011年 | 648篇 |
2010年 | 364篇 |
2009年 | 338篇 |
2008年 | 605篇 |
2007年 | 628篇 |
2006年 | 667篇 |
2005年 | 693篇 |
2004年 | 686篇 |
2003年 | 748篇 |
2002年 | 764篇 |
2001年 | 272篇 |
2000年 | 258篇 |
1999年 | 263篇 |
1998年 | 213篇 |
1997年 | 208篇 |
1996年 | 157篇 |
1995年 | 151篇 |
1994年 | 157篇 |
1993年 | 136篇 |
1992年 | 178篇 |
1991年 | 172篇 |
1990年 | 189篇 |
1989年 | 161篇 |
1988年 | 187篇 |
1987年 | 175篇 |
1986年 | 150篇 |
1985年 | 146篇 |
1984年 | 116篇 |
1983年 | 99篇 |
1982年 | 67篇 |
1981年 | 65篇 |
1980年 | 55篇 |
1979年 | 66篇 |
1978年 | 60篇 |
1977年 | 34篇 |
1975年 | 41篇 |
1971年 | 37篇 |
1966年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Dr. Ichiro Shimoyama Yoshio Nakajima Toshihiko Ito Tadahiko Shibata 《Brain topography》1997,9(4):271-274
Summary We recorded visual evoked potentials (VEPs) elicited with high or low imaginable Chinese characters (HIC or LIC), representing concrete objects or absolute concepts, respectively. A closed circle (CC) acts as control stimulus. These were displayed (at 1.6° visual angle) for 35 ms on a TV monitor. Twenty-one channel VEPs (band-pas filter: 0.05–60 Hz), using balanced non-cephalic electrodes, were recorded from –100 to 924 ms for 11 right-handed male volunteers. The VEPs were analyzed by multivariate analysis of variance (MANOVA) and comparison of topographies at four remarkable peaks (P110, N160, P230 and N320). MANOVA showed significant differences (p< 0.001) for both conditions of channel and stimuli (HIC, LIC or CC). P100 for the CC-VEPs, N160 for the HIC-and LIC-VEPs, P230 for the CC-VEPs, and N320 for the HIC-VEPs were remarkable in the posterior scalp regions. Topographies at P100 and N160 showed no difference between the HIC-and LIC-stimuli. However, those at N320 showed difference between the HIC-and LIC-stimuli over the occipital and posterior temporal areas. Those results suggest that the responses at P100 and N160 might segregate Chinese characters from non Chinese characters. N320 suggested certain processes in imagery on recognizing Chinese characters over the occipital and posterior temporal areas.We are grateful to Dr. Yoshiji Kojima of Hamamatsu University for helpful comments. 相似文献
52.
Traumatic dislocation of the testes 总被引:1,自引:0,他引:1
Traumatic dislocation of the testis is an unusual disorder. A case of bilateral traumatic dislocation of the testes is presented. Ultrasound examination is very useful for determination of the preoperative diagnosis and management of the dislocated testis. 相似文献
53.
T Motohiro Y Yoshinaga H Sasaki K Oda M Aramaki A Kawakami K Tanaka T Koga Y Shimada Y Sakata 《The Japanese journal of antibiotics》1989,42(2):465-494
It has been known that clarithromycin (TE-031, A-56268), a new macrolide antibiotic (ML), achieves higher concentrations in blood, is better excreted into urine and is better distributed into various tissues than conventional MLs. We investigated the pharmacokinetics of TE-031 in children upon oral administration of the drug in the following method. TE-031 granular preparation with a potency of 100 mg/g was given to 6 boys (5 years 4 months-14 years 0 month) with dose levels of 5 mg/kg and 10 mg/kg for each 3 boys. A tablet preparation with each tablet containing 50 mg of TE-031 was administered to 4 boys and 2 girls (8 years 5 months-11 years 6 months) with dose level of 2 tablets (i.e., 100 mg) and 3 tablets (i.e., 150 mg) for each 3 children. All administrations were done at 30 minutes before meal. Then, to conduct a cross-over test, the granule preparation was given orally to the 3 children mentioned above who was given 2 tablets and the 1 of 3 cases that were given 3 tablets at the same dose levels (100 mg and 150 mg) respectively. A bioassay was used to determine concentrations in blood of active antibiotic compounds and an high performance liquid chromatography (HPLC) was used to determine unchanged TE-031 and its main metabolite, M-5. Urinary concentrations of active antibiotic compounds were also determined by the bioassay and the HPLC was used to determine concentrations and proportions of unchanged TE-031 and its metabolites, M-1, M-4, M-5, M-6 and M-7 to figure out the urinary recovery rate in the first 6 hours. The results of these experiments are summarized as follows. 1. As was mentioned above, TE-031 was administered orally to 2 groups of children at dose levels of 5 mg/kg and 10 mg/kg, respectively. Mean serum levels of total active antibiotic compounds reached their maximum in 1 and 2 hours for the 5 mg/kg and the 10 mg/kg dosage groups, respectively, at 1.28 and 3.62 micrograms/ml, respectively. Mean half lives of serum concentrations in the 2 groups were quite similar, with values of at 2.1 and 2.0 hours, respectively. Mean serum concentrations of unchanged TE-031 determined by the HPLC method reached their peaks in 1 hour after administration in either of the 5 and 10 mg/kg dosage groups at peak levels of 0.65 micrograms/ml and 2.67 micrograms/ml, respectively. Thus, dose-response relationships were observed with TE-031 and M-5.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
54.
T Motohiro K Tanaka A Kawakami T Koga Y Shimada S Tomita Y Sakata T Fujimoto T Nishiyama N Kuda 《The Japanese journal of antibiotics》1987,40(6):1200-1214
To evaluate pharmacokinetics of amikacin (AMK), one of the aminoglycoside antibiotics, children with ages from 2 days to 11 years were treated with various doses by various administration routes, and both plasma and urinary levels of AMK were determined. The following is a summary of the results obtained: 1. Of 6 children, three were treated with 2.0 mg/kg of AMK by a 30-minute intravenous drip infusion, and the other 3 with 4.0 mg/kg by a 60-minute. Peaks of average plasma levels were observed at the ends of the infusions in both cases, and their levels were 9.23 and 13.67 micrograms/ml, respectively, showing a dose-dependency. Both half-lives and areas under plasma concentration-time curves (AUCs) were similar to those of adults. However, the volume of distribution (Vd) showed a lower value than that of adults. Peaks of average urine levels were 149.3 micrograms/ml with 2.0 mg/kg in 0-2 hours after the start of the infusion and 223.3 micrograms/ml with 4.0 mg/kg in 2-4 hours. Average urinary recovery rates within 6 hours after the start of the infusion were 95.4% with 2.0 mg/kg and 85.7% with 4.0 mg/kg. These recoveries were equal to or higher than that of adults. 2. When 3.0, 4.0 and 6.0 mg/kg of AMK were administered to 3 groups of mature or premature babies by intramuscular injection, average peak levels of AMK in plasma were 6.26, 8.61 and 12.60 micrograms/ml, respectively, at 30 minutes after the injection, showing dose-dependency. In these groups, the younger the day age after birth was, the longer the half-life became. The AUCs were larger as the half-life became longer. The Vd was larger than that in the intravenous drip infusion group, but, any particular was not observed. Average peak levels of AMK in urine were 78.83 micrograms/ml at 4-6 hours with a dose level of 3.0 mg/kg, 99.17 micrograms/ml at 2-4 hours with 4.0 mg/kg and 139.20 micrograms/ml at 0-2 hours with 6.0 mg/kg. Average urinary recovery rates within 6 hours were 36.57% with 3.0 mg/kg, 34.67% with 4.0 mg/kg and 43.77% with 6.0 mg/kg. These recovery rates were markedly lower than those observed in adults and children. One of the causes of this low recovery is that mature and premature babies have immature renal functions. 3. When 3.0 mg/kg of AMK was administered to three premature babies by a 30-minute intravenous drip infusion, the average peak plasma levels was 7.61 micrograms/ml at the end of the drip infusion.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
55.
Satoshi Kuwabara Nobuhiro Yuki Michiaki Koga Takamichi Hattori Daisuke Matsuura Masami Miyake Masatoshi Noda 《Annals of neurology》1998,44(2):202-208
To investigate the pathophysiological role of anti-GM1 antibody in Gullain-Barre syndrome (GBS), we reviewed sequential nerve conduction studies of 345 nerves in 34 GBS patients. Statistically significant correlation between IgG anti-GM1 antibodies and electrodiagnoses was found. Sixteen IgG anti-GM1-positive patients were classified as having acute motor sensory axonal neuropathy (AMAN or AMSAN) (12 patients), as having acute inflammatory demyelinating polyneuropathy (AIDP) (3 patientsrpar;, or as undetermined (1 patient) by electrodiagnostic criteria. Besides axonal features, there was rapid resolution of conduction slowing and block. In 3 patients initially diagnosed as having AIDP, conduction slowing was resolved within days, and 1 of them and 3 AMAN patients showed markedly rapid increases in amplitudes of distal compound muscle action potentials that were not accompanied by prolonged duration and polyphasia. The time courses of conduction abnormalities were distinct from those in IgG anti-GM1-negative AIDP patients. Rapid resolution of conduction slowing and block, and the absence of remyelinating slow components, suggest that conduction failure may be caused by impaired physiological conduction at the nodes of Ranvier. Reversible conduction failure as well as axonal degeneration constitutes the pathopsiological mechanisms in IgG anti-GM1)positive GBS. In both cases, immune-mediated attack probably occurs on the axolemma of motor fibers. 相似文献
56.
Seiji Nakata Jin Sato Kyoichi Imai Hidetoshi Yamanaka Yoshio Ichinose 《International journal of urology》1995,2(3):191-197
Background Prostate cancer is rare in Asia, but the number of patients is increasing in Japan. We conducted an epidemiological study of prostate cancer in Gunma Prefecture, Japan, to investigate the trends and characteristics of the disease.
Methods: The subjects were 1.411 prostate cancer patients newly diagnosed between 1985 and and 656 patients who died from prostate cancer between 1981 and 1992. The incidence and mortality rates were calculated by year, demographic region and age.
Results: The yearly incidence rate showed an increase but the mortality rate showed no marked fluctuations. There was no significant difference between urban and ruraI districts in either incidence or mortality rate. The incidence rate tended to be high in the northern part of the prefecture, but no marked variation in mortality rate was seen. The incidence and mortality rates in districts with a history of manganese mining were high compared to those in districts without mining. In contrast, the incidence and mortality rates in districts with a history of zinc mining were comparatively lower. Both incidence and mortality rates showed a marked increase with age. The age-specific incidence showed a double logarithmic relationship to age.
Conclusions: The increase of the yearly incidence rate might be due to changes in lifestyle and environmental factors, improved diagnostic techniques, and increased awareness among the general public regarding prostate disease. Further investigation is needed to clarify the pattern and the causes of regional differences in the incidence and mortality rates. The possibilities that manganese and zinc might be related to prostatic carcinogenesis are suggested. Int J Urol 1995:2:191–197 相似文献
Methods: The subjects were 1.411 prostate cancer patients newly diagnosed between 1985 and and 656 patients who died from prostate cancer between 1981 and 1992. The incidence and mortality rates were calculated by year, demographic region and age.
Results: The yearly incidence rate showed an increase but the mortality rate showed no marked fluctuations. There was no significant difference between urban and ruraI districts in either incidence or mortality rate. The incidence rate tended to be high in the northern part of the prefecture, but no marked variation in mortality rate was seen. The incidence and mortality rates in districts with a history of manganese mining were high compared to those in districts without mining. In contrast, the incidence and mortality rates in districts with a history of zinc mining were comparatively lower. Both incidence and mortality rates showed a marked increase with age. The age-specific incidence showed a double logarithmic relationship to age.
Conclusions: The increase of the yearly incidence rate might be due to changes in lifestyle and environmental factors, improved diagnostic techniques, and increased awareness among the general public regarding prostate disease. Further investigation is needed to clarify the pattern and the causes of regional differences in the incidence and mortality rates. The possibilities that manganese and zinc might be related to prostatic carcinogenesis are suggested. Int J Urol 1995:2:191–197 相似文献
57.
We report herein the case of a 56-year-old woman who developed secondary Kwashiorkor 9 years after undergoing a total gastrectomy for early gastric cancer. Until she began developing the symptoms of Kwashiorkor, including general fatigue, edema of the face and extremities, anemia, alopecia, and weight loss, she had been leading a normal life post-gastrectomy. Her symptoms were alleviated by total parenteral nutrition (TPN) therapy, but reappeared soon after TPN therapy was discontinued. Therefore, she required several subsequent courses of TPN. In an attempt to permanently resolve the ongoing Kwashiorkor symptoms, reconstructive surgery involving transposition of the jejunum from the previous Graham method to the interposition method was performed 10 years after the initial gastrectomy. After the second operation, her malnutrition was completely alleviated, and she has been in good health for the 8 years since. To our knowledge, there has been no other report of the symptoms of secondary Kwashiorkor after total gastrectomy being alleviated by altering the procedure of reconstruction of the intestinal tract. Thus, we recommend surgical treatment to alter the digestive continuity to a more physiological pathway for selected patients with secondary Kwashiorkor syndrome. 相似文献
58.
We conducted a prospective survey on the incidence of respiratory
complications associated with tracheal intubation and extubation in 1005
patients who underwent elective general anaesthesia over a 4-month period.
During induction of anaesthesia, respiratory complications occurred in 46
patients (4.6%; 95% confidence limits (CL): 3.3, 5.9%). The common
complications were coughing (1.5%) and difficult ventilation through a
facemask (1.4%). Tracheal intubation was difficult in eight patients
(0.8%). Complications occurred immediately after tracheal extubation in 127
patients (12.6%; 95% CL: 10.6, 14.7) and in the recovery room in 95
patients (9.5%; 95% CL: 7.6, 11.3%). The common complications immediately
after extubation were coughing (6.6%) and oxygen desaturation (SaO2 <
90%) (2.4%), and in the recovery room, airway obstruction (3.8%) and
coughing (3.1%). The incidence of complications was significantly higher
immediately after tracheal extubation than during induction of anaesthesia
(P << 0.001). Even when all incidents of coughing that occurred after
tracheal extubation were disregarded as a complication, the overall
incidence was still higher immediately after extubation (7.4%) than during
induction of anaesthesia (P < 0.01). We conclude that the incidence of
respiratory complications associated with tracheal extubation may be higher
than that during tracheal intubation.
相似文献
59.
A single oral administration of orthophenylphenol (OPP, 1400 mg/kg; about half the LD50) to male Fischer 344 rats produced an elevation of serum transaminase activity 24 h later. Pretreatment with l-buthionine-S,R-sulfoximine (BSO, 900 mg/kg) in the OPP-treated rats potentiated the hepatic and renal damage which was accompanied by necrosis. Six hours after the administration of OPP (700 or 1400 mg/kg), hepatic and renal glutathione (GSH) levels decreased with increasing dosage. Hepatic GSH depletion with OPP was enhanced with BSO pretreatment and the recovery of GSH in both organs was slow in the high-dose OPP group. These results suggest that hepatic and renal damage is associated with a serious and prolonged GSH depletion. When either phenyl-p-benzoquinone (PBQ) or phenylhydroquinone (PHQ), which are intermediates of OPP, was administered orally to rats at 700 or 1400 mg/kg, the mortality with the high dose of PBQ was 75% at 24 h. The serum transaminase activity and UN level increased with the low dose of PBQ, accompanied by necrotic hepatocytes. The toxic effects of PHQ on kidney or liver were less than those on PBQ. These observations suggest that the liver and kidney may be target organs for toxic actions of a large dose of OPP and its intermediate, PBQ.Part of this work was presented at IInd International ISSX Meeting Xenobiotic Metabolism and Disposition, May 16–20, 1988, Kobe, Japan 相似文献
60.
Summary We report here a 75-year-old-male with a slowly progressive dementia of 5-year duration along with a rapid exacerbation of symptoms in the terminal 3 months. Neuropathological examinations revealed findings consistent with conspicuous Alzheimer's disease and mild Creutzfeldt-Jakob disease (CJD). The plaque amyloid was exclusively composed of -protein. The immunohistochemistry of prion protein using hydrolytic autoclaving pretreatment showed diffuse gray matter stainings in the sections of both the cerebral and cerebellar cortices. This method was thus considered useful in confirming the diagnosis of CJD for this case. 相似文献