全文获取类型
收费全文 | 12365篇 |
免费 | 547篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 221篇 |
儿科学 | 216篇 |
妇产科学 | 181篇 |
基础医学 | 1667篇 |
口腔科学 | 301篇 |
临床医学 | 796篇 |
内科学 | 3089篇 |
皮肤病学 | 129篇 |
神经病学 | 1182篇 |
特种医学 | 608篇 |
外科学 | 1960篇 |
综合类 | 58篇 |
预防医学 | 444篇 |
眼科学 | 235篇 |
药学 | 721篇 |
中国医学 | 23篇 |
肿瘤学 | 1155篇 |
出版年
2023年 | 92篇 |
2022年 | 144篇 |
2021年 | 247篇 |
2020年 | 131篇 |
2019年 | 199篇 |
2018年 | 242篇 |
2017年 | 176篇 |
2016年 | 224篇 |
2015年 | 212篇 |
2014年 | 254篇 |
2013年 | 314篇 |
2012年 | 567篇 |
2011年 | 615篇 |
2010年 | 330篇 |
2009年 | 279篇 |
2008年 | 484篇 |
2007年 | 519篇 |
2006年 | 600篇 |
2005年 | 613篇 |
2004年 | 565篇 |
2003年 | 565篇 |
2002年 | 554篇 |
2001年 | 411篇 |
2000年 | 475篇 |
1999年 | 423篇 |
1998年 | 198篇 |
1997年 | 145篇 |
1996年 | 136篇 |
1995年 | 123篇 |
1994年 | 84篇 |
1993年 | 80篇 |
1992年 | 223篇 |
1991年 | 253篇 |
1990年 | 247篇 |
1989年 | 258篇 |
1988年 | 241篇 |
1987年 | 240篇 |
1986年 | 208篇 |
1985年 | 190篇 |
1984年 | 160篇 |
1983年 | 102篇 |
1982年 | 60篇 |
1981年 | 60篇 |
1979年 | 92篇 |
1976年 | 46篇 |
1974年 | 47篇 |
1972年 | 64篇 |
1971年 | 46篇 |
1970年 | 46篇 |
1969年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Susumu Shibasaki Koichi Suda Masaya Nakauchi Kenichi Nakamura Kenji Kikuchi Kazuki Inaba Ichiro Uyama 《World journal of gastroenterology : WJG》2020,26(11):1172-1184
BACKGROUND Minimally invasive surgery for gastric cancer(GC) has gained widespread use as a safe curative procedure especially for early GC.AIM To determine risk factors for postoperative complications after minimally invasive gastrectomy for GC.METHODS Between January 2009 and June 2019, 1716 consecutive patients were referred to our division for primary GC. Among them, 1401 patients who were diagnosed with both clinical and pathological Stage Ⅲ or lower GC and underwent robotic gastrectomy(RG) or laparoscopic gastrectomy(LG) were enrolled. Retrospective chart review and multivariate analysis were performed for identifying risk factors for postoperative morbidity.RESULTS Morbidity following minimally invasive gastrectomy was observed in 7.5% of the patients. Multivariate analyses demonstrated that non-robotic minimally invasive surgery, male gender, and an operative time of ≥ 360 min were significant independent risk factors for morbidity. Therefore, morbidity was compared between RG and LG. Accordingly, propensity-matched cohort analysis revealed that the RG group had significantly fewer intra-abdominal infectious complications than the LG group(2.5% vs 5.9%, respectively; P = 0.038), while no significant differences were noted for other local or systemic complications.Multivariate analyses of the propensity-matched cohort revealed that non-robotic minimally invasive surgery [odds ratio = 2.463(1.070–5.682); P = 0.034] was a significant independent risk factor for intra-abdominal infectious complications.CONCLUSION The findings showed that robotic surgery might improve short-term outcomes following minimally invasive radical gastrectomy by reducing intra-abdominal infectious complications. 相似文献
2.
3.
4.
5.
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
6.
Jun Agata Nobuyuki Ura Hideaki Yoshida Yasuyuki Shinshi Haruki Sasaki Masaya Hyakkoku Shinya Taniguchi Kazuaki Shimamoto 《Hypertension research》2006,29(11):865-874
Angiotensin II receptor blockers (ARBs) are widely used for the treatment of hypertension. It is believed that treatment with an ARB increases the level of plasma angiotensin II (Ang II) because of a lack of negative feedback on renin activity. However, Ichikawa (Hypertens Res 2001; 24: 641-646) reported that long-term treatment of hypertensive patients with olmesartan resulted in a reduction in plasma Ang II level, though the mechanism was not determined. It has been reported that angiotensin 1-7 (Ang-(1-7)) potentiates the effect of bradykinin and acts as an angiotensin-converting enzyme (ACE) inhibitor. It is known that ACE2, which was discovered as a novel ACE-related carboxypeptidase in 2000, hydrolyzes Ang I to Ang-(1-9) and also Ang II to Ang-(1-7). It has recently been reported that olmesartan increases plasma Ang-(1-7) through an increase in ACE2 expression in rats with myocardial infarction. We hypothesized that over-expression of ACE2 may be related to a reduction in Ang II level and the cardioprotective effect of olmesartan. Administration of 0.5 mg/kg/day of olmesartan for 4 weeks to 12-week-old stroke-prone spontaneously hypertensive rats (SHRSP) significantly reduced blood pressure and left ventricular weight compared to those in SHRSP given a vehicle. Co-administration of olmesartan and (D-Ala7)-Ang-(1-7), a selective Ang-(1-7) antagonist, partially inhibited the effect of olmesartan on blood pressure and left ventricular weight. Interestingly, co-administration of (D-Ala7)-Ang-(1-7) with olmesartan significantly increased the plasma Ang II level (453.2+/-113.8 pg/ml) compared to olmesartan alone (144.9+/-27.0 pg/ml, p<0.05). Moreover, olmesartan significantly increased the cardiac ACE2 expression level compared to that in Wistar Kyoto rats and SHRSP treated with a vehicle. Olmesartan significantly improved cardiovascular remodeling and cardiac nitrite/ nitrate content, but co-administration of olmesartan and (D-Ala7)-Ang-(1-7) partially reversed this anti-remodeling effect and the increase in nitrite/nitrate. These findings suggest that olmesartan may exhibit an ACE inhibitory action in addition to an Ang II receptor blocking action, prevent an increase in Ang II level, and protect cardiovascular remodeling through an increase in cardiac nitric oxide production and endogenous Ang-(1-7) via over-expression of ACE2. 相似文献
7.
Kosuke Kaida Masaya Takahashi Torbj?rn Akerstedt Akinori Nakata Yasumasa Otsuka Takashi Haratani Kenji Fukasawa 《Clinical neurophysiology》2006,117(7):1574-1581
OBJECTIVE: The Karolinska sleepiness scale (KSS) is frequently used for evaluating subjective sleepiness. The main aim of the present study was to investigate the validity and reliability of the KSS with electroencephalographic, behavioral and other subjective indicators of sleepiness. METHODS: Participants were 16 healthy females aged 33-43 (38.1+/-2.68) years. The experiment involved 8 measurement sessions per day for 3 consecutive days. Each session contained the psychomotor vigilance task (PVT), the Karolinska drowsiness test (KDT-EEG alpha & theta power), the alpha attenuation test (AAT-alpha power ratio open/closed eyes) and the KSS. RESULTS: Median reaction time, number of lapses, alpha and theta power density and the alpha attenuation coefficients (AAC) showed highly significant increase with increasing KSS. The same variables were also significantly correlated with KSS, with a mean value for lapses (r=0.56). CONCLUSIONS: The KSS was closely related to EEG and behavioral variables, indicating a high validity in measuring sleepiness. SIGNIFICANCE: KSS ratings may be a useful proxy for EEG or behavioral indicators of sleepiness. 相似文献
8.
Endoscopic anterior cruciate ligament reconstruction using a computer-assisted fluoroscopic navigation system 总被引:3,自引:0,他引:3
Hisatada Hiraoka Sou Kuribayashi Akira Fukuda Naoshi Fukui Kozo Nakamura 《Journal of orthopaedic science》2006,11(2):159-166
Background During anterior cruciate ligament (ACL) reconstruction, placement of the reconstructed ligament affects the clinical results.
To accomplish accurate and reproducible placement of the tibial bone tunnel, we employed a fluoroscopic navigation system
for endoscopic ACL reconstruction. In this study, preciseness of the tibial tunnel placement was evaluated, and the advantages
and disadvantages of this navigation system for endoscopic ACL reconstruction are discussed.
Methods Altogether, 16 knees of 16 patients who had undergone ACL reconstruction using this system (navi group) were evaluated regarding
the positioning of the tibial tunnel against Blumensaat's line using X-p and the route of the graft by magnetic resonance
imaging (MRI). Another 16 knees of 16 patients who underwent endoscopic ACL reconstruction without the navigation system were
the controls (control group).
Results At the 1-year follow-up, maximally extended lateral knee X-p revealed that the anterior edge of the tibial tunnel and Blumensaat's
line were almost aligned and that roof impingement was avoided; the T2-weighted MR images showed that the graft was placed
close to and parallel to the intercondylar roof in all the knees of the navi group. The ratio of the distance between Blumensaat's
line and the anterior edge of the tibial tunnel at the level of the tibial plateau to the anteroposterior width in fully extended
true lateral radiographs was 2.7% ± 3.4% in the navi group and 8.4% ± 7.4% in the control group.
Conclusions The computer-assisted fluoroscopic navigation system improves accuracy and decreases dispersion of the tibial tunnel placement
against Blumensaat's line in single-bundle ACL reconstruction. This innovative device renders the reconstruction procedure
more reliable, eliminating the problem of skeletal variation among patients. However, the function of this navigation system
for femoral tunnel placement is insufficient at present. Further refinement of the system is necessary, and the method of
application requires improvement. 相似文献
9.
Yasuyuki Suzuki Kazuyuki Daitoku Masahito Minakawa Kozo Fukui Ikuo Fukuda 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(1):44-46
We report the case of a 4-year-old girl who had quadricuspid aortic valve regurgitation with tetralogy of Fallot and pulmonary
atresia. This combination is very uncommon. Aortic valve replacement was performed successfully due to aortic regurgitation
which had progressed one year after the total repair. The dilated aortic annulus plus quadricuspid aortic valve may result
in progressive aortic regurgitation for a short period. 相似文献
10.
Experiments were performed on spinalized rats, transected at the Cl level. The intravenous administration of TRH and its analog YM-14673 (N alpha-[(S)-4-oxo-2-azetidinyl) carbonyl]-L-histidyl-L-prolinamide dehydrate) produced marked increases in the amplitude of mono- and polysynaptic reflex potentials and those of the withdrawal flexor reflexes. The effects of YM-14673 were stronger and longer-lasting than those of TRH. The stimulant action of TRH and YM-14673 on the flexor reflexes was not antagonized by prazosin, chlorpromazine, haloperidol or cyproheptadine, suggesting no involvement of the release of catecholamines or serotonin in the stimulant effects of TRH and its analog. Therefore, YM-14673 may be beneficial for the treatment of several spinal motor neuron diseases. 相似文献