全文获取类型
收费全文 | 12284篇 |
免费 | 563篇 |
国内免费 | 101篇 |
专业分类
耳鼻咽喉 | 92篇 |
儿科学 | 257篇 |
妇产科学 | 149篇 |
基础医学 | 1387篇 |
口腔科学 | 219篇 |
临床医学 | 699篇 |
内科学 | 3583篇 |
皮肤病学 | 350篇 |
神经病学 | 821篇 |
特种医学 | 368篇 |
外科学 | 1978篇 |
综合类 | 56篇 |
预防医学 | 357篇 |
眼科学 | 152篇 |
药学 | 624篇 |
中国医学 | 49篇 |
肿瘤学 | 1807篇 |
出版年
2023年 | 76篇 |
2022年 | 126篇 |
2021年 | 246篇 |
2020年 | 138篇 |
2019年 | 186篇 |
2018年 | 280篇 |
2017年 | 194篇 |
2016年 | 248篇 |
2015年 | 269篇 |
2014年 | 373篇 |
2013年 | 405篇 |
2012年 | 730篇 |
2011年 | 810篇 |
2010年 | 458篇 |
2009年 | 367篇 |
2008年 | 784篇 |
2007年 | 850篇 |
2006年 | 775篇 |
2005年 | 845篇 |
2004年 | 850篇 |
2003年 | 873篇 |
2002年 | 823篇 |
2001年 | 134篇 |
2000年 | 97篇 |
1999年 | 157篇 |
1998年 | 193篇 |
1997年 | 144篇 |
1996年 | 160篇 |
1995年 | 151篇 |
1994年 | 139篇 |
1993年 | 99篇 |
1992年 | 100篇 |
1991年 | 102篇 |
1990年 | 66篇 |
1989年 | 68篇 |
1988年 | 61篇 |
1987年 | 47篇 |
1986年 | 39篇 |
1985年 | 51篇 |
1984年 | 64篇 |
1983年 | 42篇 |
1982年 | 50篇 |
1981年 | 51篇 |
1980年 | 21篇 |
1979年 | 35篇 |
1978年 | 17篇 |
1977年 | 15篇 |
1975年 | 17篇 |
1974年 | 9篇 |
1973年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
171.
Shohei Nakamura Yutaka Kobayashi Kazuhiko Tozuka Akihiko Tokue Akira Kimura Chikuma Hamada 《The Journal of urology》1996,156(4):1275-1279
Purpose
Circadian changes in urinary frequency, diuresis and bladder capacity were evaluated in middle-aged and elderly patients.Materials and Methods
A total of 2,703 urinations from 50 men (median age 66 years) was recorded with a 24-hour uroflowmetry system.Results
During a 24-hour period the elderly group showed increased frequency and decreased bladder capacity. No difference was observed in diuresis between the 2 age groups. From midnight to 6 a.m. frequency in the elderly group was significantly greater (p less than 0.01) than that in the middle-aged group.Conclusions
Increased frequency in the elderly group during these hours was primarily due to an increase in diuresis. 相似文献172.
Fujio Atsuta Kenichi Sato Koscak Maruyama Yutaka Shimada 《Journal of muscle research and cell motility》1993,14(5):511-517
Summary The distribution of connectin (titin), nebulin and -actinin in the areas of myotendinous junctions of chicken pectoralis muscles was examined by immunocytochemical methods. Staining with antibodies against connectin (4C9, SM1 and P1200) and nebulin formed doublets flanking nonterminal Z-bands; near the end of muscle fibres singlets were seen within the terminal sarcomere on the side adjacent to the terminal Z-bands. The apical regions of muscle processes, where no myosin filaments are present although actin filaments exist, were reactive with anti-nebulin but not with anti-connection. Antibodies against pectoralis (skeletal muscle type) -actinin stained non terminal Z-bands and that against gizzard (smooth muscle type) the sarcolemma. Terminal Z-bands were unreactive with both of these antibodies. These findings indicate that, although terminal and nonterminal Z-bands differ in their molecular composition, connectin and nebulin filaments appear to link myosin and actin filaments, respectively, to both Z-band types. 相似文献
173.
Kawanishi Toru Takahashi Atsushi Ohno Yasuo Takanaka Akira Kasuya Yutaka Omori Yoshihito 《Archives of toxicology》1983,54(4):323-330
A simple method for the quantitative estimation of the formation of N-nitrosodimethylamine (NDMA) in mice has been developed. Mice were frozen in liquid nitrogen and homogenized. NDMA was then extracted and analyzed by a gas chromatograph equipped with a thermal energy analyzer. In normal mice NDMA (100 nmole) administered orally was rapidly metabolized and recovery of NDMA was about 10% after 60 min. However, when pyrazole (300 mg/kg) was injected i.p. to mice 60 min before the administration of NDMA, more than 80% of the administered NDMA could be recovered within 60 min. This result suggested that in pyrazole pretreated mice the accurate amount of NDMA formed could be estimated. Therefore the NDMA formation was measured in the pyrazole pretreated mice. When 0.25 mole of aminopyrine and from 0.25 to 2.0 umole of sodium nitrite were simultaneously administered orally, the amount of the NDMA formation in 20 min was found to be from 8.2 to 60.3 nmole. These values are equal to about from 30 to 200 g/kg of body weight which are nearly daily doses expected to cause the carcinogenic effect on mice or rats. This method of measuring NDMA in pyrazole pretreated mice appears to be useful for investigating the in vivo formation of NDMA quantitatively. 相似文献
174.
Shin-ichi Hirano Naoki Agata Yutaka Hara Hiroshi Iguchi Masataka Shirai Hiroshi Tone Norimoto Urakawa 《Cancer chemotherapy and pharmacology》1991,28(4):266-272
Summary In the present study we examined the effects of pirarubicin [(2R)-4-0-tetrahydropyranyladriamycin, THP] on a cardiovascular system. An injection of THP (0.39–3.13 mg/kg, i. v.) reduced the mean blood pressure and caused an increase in the respiratory air rate in anesthetized rats. At 1.5×10–6–1.5×10–5
m, THP markedly relaxed a contraction induced by 10–7
m norepinephrine in rat aorta with endothelium but not in that without endothelium. At a dose of 0.02–0.5 mg, THP produced an increase in the contractile force and the perfusion flow of isolated perfused guinea pig hearts. At a higher concentration (4.5×10–5–1.5×10–4
m), it produced a slight increase in the contractile force of the left atria in guinea pigs. This positive inotropic action of THP was inhibited by diphenhydramine (10–6–5×10–5
m), chlorpheniramine (3×10–7–3×10–5
m), and tripelennamine (3×10–7–3×10–5
m) but not by propranolol (10–6
m), cimetidine (10–5
m), diltiazem (10–6
m), or ryanodine (10–8
m). THP given i. v. at 2.5 mg/kg elevated the plasma histamine level in anesthetized dogs. From these data, we conclude that THP mainly relaxed the rat aorta in the presence of endothelium and that at higher concentrations, it increased the contractile force in the cardiac muscle, probably mediated through the release of histamine. 相似文献
175.
Koichi Kono Yasuhisa Yoshida Misuzu Watanabe Yutaka Tanioka Yukio Orita Tomotaro Dote Yasumori Bessho Yuka Takahashi Junichi Yoshida Yoshiko Sumi 《International archives of occupational and environmental health》1992,64(5):343-346
Summary To define the relationship between ionic fluoride concentration in the serum of workers and the amount of hydrofluoric acid (HF) in the work environment, pre-and postshift serum and urine samples of 142 HF workers and 270 unexposed workers were examined. The maximum and minimum concentrations of HF in the air in each workshop varied from the mean by less than 30%. The pre-exposure levels of serum and urinary fluoride in HF workers were higher (P < 0.001) than the control values. This suggests that fluoride excretion from the body continues for at least 12 h. The postshift serum and urinary fluoride concentrations of these workers were significantly higher (P < 0.001) than the preshift concentrations. A good correlation (r = 0.64) was obtained between postshift serum fluoride and postshift urine fluoride. There was a linear relationship between mean serum fluoride concentration and HF concentration in the workshop. A mean fluoride concentration of 82.3 g/l with a lower fiducial limit (95%, P = 0.05) of 57.9 g/l was estimated to correspond to an atmospheric HF concentration of 3 ppm. This is the maximum allowable environmental concentration recommended by the Japanese Association of Industrial Health, and it is also the threshold limit value suggested by the American Conference of Governmental Industrial Hygienists. The results demonstrate that exposure to HF can be monitored by determining the serum fluoride concentration. 相似文献
176.
Hyperthermo-chemotherapy combined with cytoreductive surgery for the treatment of gastric cancer with peritoneal dissemination 总被引:6,自引:0,他引:6
Yutaka Yonemura M.D. Takashi Fujimura M.D. Sachio Fushida M.D. Shigeru Takegawa M.D. Toru Kamata M.D. Kanji Katayama M.D. Takeo Kosaka M.D. Akio Yamaguchi M.D. Kouichi Miwa M.D. Ituo Miyazaki M.D. 《World journal of surgery》1991,15(4):530-535
Continuous hyperthermic peritoneal perfusion (CHPP) with anticancer agents (mitomycin C and cisplatin) in warm saline was performed in patients with peritoneal dissemination of gastric cancer following resection of the primary lesion. The effect of CHPP was examined by a second-look operation. This study includes 41 cases of gastric cancer with peritoneal dissemination but without liver metastasis treated during the past 6 years. The overall median survival was 14.6 months to 64.2 months from CHPP to death and the 3-year survival rate was 28.5%. Second look surgery revealed a remarkable diminution in the degree of peritoneal dissemination in 7 (50%) of 14 patients with disappearance of ascites after only one course of CHPP in 7 (77.8%) of 9 patients. Long-term 3 year-survival was noted in 4 (9.8%) patients on CHPP. Side effects were renal insufficiency in 2 (5%) patients, leukopenia in 2 (5%) patients, and perforation of the small intestine in 1 (2%) patient. These results suggest the effectiveness of CHPP in the treatment of gastric cancer with peritoneal dissemination.
Resumen La perfusión hipertérmica continua (PHTC) con agentes anticancerosos (mitocina G y cisplatino) y solutión salina fue realizada en pacientes con cáncer gástrico con diseminación peritoneal después de resección de la lesión primaria, y el efecto de PHTC fue determinado mediante reexploración (operación de second look, OSL). La población de pacientes está constituída por 41 casos de cáncer gástrico con diseminación peritoneal pero sin metástasis hepáticas, tratdos en el curso de los últimos 6 años. La sobrevida media global fue de 437 dias (rango 28 a 1925 días) desde la PHTC hasta la muerte y la tasa de sobrevida a 3 años fue 28.5%. La OSL reveló una notoria disminución de la diseminación peritoneal en 7 (50%) de 14 casos y desaparición de la ascites después de sólo un ciclo de PHTC en 7 de 9 casos con ascitis. Sobrevida de 3 años ocurrió en 4 casos. Los efectos colaterales fueron insuficiencia renal en 2 casos (5%), leucopenia en 2 casos (5%) y perforación del intestino delgado en 1 caso (2%). Los anteriores resultados sugieren que la PHTC es eficaz en el tratamiento del cáncer gástrico con diseminación peritoneal.
Résumé La perfusion péritonéale continue hyperthermique (PPCH) avec des agents anticancéreux comme le mitomycine C et la cis-platine avec sérum physiologique chauffé a été instaurée lorsqu'une carcinose d'origine gastrique a été trouvée. Les effets de la PCH ont été évalués chez 16 patients lors d'un second-look (SL). Cette étude concerne 41 patients avec carcinose péritonéale sans métastase hépatique observés au cours des 6 dernières années. La survie globale médiane était de 437 jours (extrêmes 28 à 1925 jours): le taux de survie a 3 ans était de 28.5%. Les lésions avaient diminué de façon notable chez 7 (50%) de 14 patients. L'ascite a disparu dans 7 des 9 cas. Une survie à long terme (3 ans) a été notée dans 4 cas. Les effets secondaires ont été une insuffisance rénale dans 2 cas (5%), une leucopénie dans 2 cas (5%) et une perforation de l'intestin grêle dans un cas (2%). Les résultats suggèrent que la PPCH est efficace dans le traitement du cancer gastrique avec dissémination péritonéale.相似文献
177.
Does Hyperthermia Induce Peritoneal Damage in Continuous Hyperthermic Peritoneal Perfusion? 总被引:3,自引:0,他引:3
Shido A Ohmura S Yamamoto K Kobayashi T Fujimura T Yonemura Y 《World journal of surgery》2000,24(5):507-511
To investigate the mechanisms of the peritoneal damage induced by continuous hyperthermic peritoneal perfusion (CHPP), protein
and fluid loss during and after CHPP and continuous normothermic peritoneal perfusion (CNPP) was studied. Sixteen patients
with advanced gastric cancer underwent peritoneal perfusion therapy with saline solution containing 150 to 300 mg cisplatin
and 30 to 60 mg mitomycin C for 60 minutes. The temperature in Douglas' pouch was maintained at 42.0°C in the CHPP group (n= 9) and 37.0°C in the CNPP group (n= 7) during perfusion. No statistical differences were found in patients' characteristics between the groups except the maximum
temperature in Douglas' pouch during perfusion (41.6°± 0.4°C and 37.6°± 0.4°C in CHPP and CNPP groups, respectively, p < 0.05). The amount of protein lost into the perfusate was 0.35 ± 0.22 g/kg body weight in the CHPP group and 0.37 ± 0.19
g/kg in the CNPP group, showing no significant difference. On the day of surgery, there was no significant difference in the
amount of protein and fluid lost through the abdominal drains between the CHPP group (27.9 ± 24.6 mg/kg/hr and 0.94 ± 0.63
ml/kg/hr, respectively) and the CNPP group (25.9 ± 8.6 mg/kg/hr and 1.03 ± 0.31 ml/kg/hr, respectively). We could not find
any significant differences in postoperative protein and fluid loss between the groups on the following 3 days either. We
conclude that the peritoneal damage by CHPP is not caused by the hyperthermia but by the peritoneal perfusion with saline
solution containing anticancer drugs. 相似文献
178.
Kato M Imamura M Hosotani R Shimada Y Doi R Itami A Komoto I KosakaM T T Konishi J 《World journal of surgery》2000,24(11):1425-1430
The intravenous secretin injection test (secretin test) has been used for the differential diagnosis of gastrinoma. In this
study we report that the intraoperative secretin test (IOS test) is also useful for determining the extent of curability in
patients with Zollinger-Ellison syndrome (ZES). Twelve patients with ZES underwent surgical exploration and the IOS test.
The results of the IOS test were obtained by rapid radioimmunoassay of the serum gastrin level (IRG) within 60 minutes. The
test was diagnosed as negative when the maximum increase of serum IRG was less than 80 pg/ml and also less than 20% of the
basal serum IRG level. Three of the twelve patients underwent pancreatoduodenectomy (PD), and two patients underwent distal
pancreatectomy. Extirpation of duodenal tumors with dissection of regional lymph nodes was performed in seven patients. In
two of the seven patients the IOS test remained positive after extirpation of the duodenal tumors and the dissection of regional
lymph nodes. In one patient PD was performed on the basis of the positive results, and the IOS test became negative after
PD. In the other patient, two tiny metastatic liver tumors were identified and were resected, but the IOS test did not become
negative. We closed the abdomen in 11 patients when we obtained negative results from the IOS test. The results of the IOS
test were almost identical to the data obtained by the standard assay postoperatively. The serum IRG levels of all but one
patient fell to the normal level, and the secretin test became negative postoperatively. The IOS test is thus useful and indispensable
for curative resection of microgastrinomas in patients with ZES. 相似文献
179.
180.
The influence of androgen deprivation therapy on dihydrotestosterone levels in the prostatic tissue of patients with prostate cancer. 总被引:3,自引:0,他引:3
PURPOSE: The influence of androgen deprivation therapy on dihydrotestosterone levels in the prostatic tissue is not clearly known. Changes in dihydrotestosterone levels in the prostatic tissue during androgen deprivation therapy in the same patients have not been reported. We analyzed dihydrotestosterone levels in prostatic tissue before and after androgen deprivation therapy. EXPERIMENTAL DESIGN: A total of 103 patients who were suspected of having prostate cancer underwent prostatic biopsy. Sixty-nine patients were diagnosed as having prostate cancer whereas the remaining 34 were negative. Serum samples were collected before biopsy or prostatectomy. Dihydrotestosterone levels in prostatic tissue and serum were analyzed using liquid chromatography/electrospray ionization-mass spectrometry after polar derivatization. In 30 of the patients with prostate cancer, dihydrotestosterone levels in prostatic tissue were determined by performing rebiopsy or with prostate tissues excised after 6 months on androgen deprivation therapy with castration and flutamide. RESULTS: Dihydrotestosterone levels in prostate tissue after androgen deprivation therapy remained at approximately 25% of the amount measured before androgen deprivation therapy. Dihydrotestosterone levels in serum decreased to approximately 7.5% after androgen deprivation therapy. The level of dihydrotestosterone in prostatic tissue before androgen deprivation therapy was not correlated with the serum level of testosterone. Serum levels of adrenal androgens were reduced to approximately 60% after androgen deprivation therapy. CONCLUSIONS: The source of dihydrotestosterone in prostatic tissue after androgen deprivation therapy involves intracrine production within the prostate, converting adrenal androgens to dihydrotestosterone. Dihydrotestosterone still remaining in prostate tissue after androgen deprivation therapy may require new therapies such as treatment with a combination of 5alpha-reductase inhibitors and antiandrogens, as well as castration. 相似文献