全文获取类型
收费全文 | 222篇 |
免费 | 1篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 26篇 |
妇产科学 | 2篇 |
基础医学 | 23篇 |
口腔科学 | 1篇 |
临床医学 | 13篇 |
内科学 | 52篇 |
皮肤病学 | 4篇 |
神经病学 | 14篇 |
特种医学 | 4篇 |
外科学 | 48篇 |
综合类 | 1篇 |
预防医学 | 2篇 |
药学 | 10篇 |
肿瘤学 | 22篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2017年 | 1篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2007年 | 2篇 |
2006年 | 14篇 |
2005年 | 10篇 |
2004年 | 13篇 |
2003年 | 9篇 |
2002年 | 2篇 |
2001年 | 3篇 |
1999年 | 9篇 |
1998年 | 18篇 |
1997年 | 11篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 1篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1959年 | 1篇 |
1958年 | 6篇 |
1957年 | 4篇 |
1956年 | 4篇 |
1955年 | 4篇 |
1954年 | 5篇 |
排序方式: 共有223条查询结果,搜索用时 0 毫秒
41.
HARUAKI YAJIMA KENICHI AKAJI KAZUYA MITANI NOBUTAKA FUJII SUSUMU FUNAKOSHI HIDEKI ADACHI MARIKO OISHI YOSHIHARU AKAZAWA 《Chemical biology & drug design》1979,14(2):169-176
A new devised arginine derivative, NG-mesitylene-2-sulfonylarginine, Arg(Mts), was employed for the synthesis of hypothalamic substance P and neurotensin. The former was obtained in 74% yield by treatment of the protected undecapeptide amide, Z - Arg(Mts) - Pro - Lys(Z) - Pro - Gln - Gln - Phe - Phe - Gly - Leu - Met(O)-NH2, with methanesulfonic acid in the presence of anisole followed by reduction of the sulfoxide with 2-mercaptoethanol. The latter was obtained in 54% yield by the similar treatment of the protected tridecapeptide ester, Z-Pyr-Leu - Tyr - Glu(OBzl) - Asn - Lys(Z)-Pro-Arg(Mts) - Arg(Mts) - Pro - Tyr-Ile-Leu-OBzl, with methanesulfonic acid. As scavenger, a mixture of anisole-thioanisole-o-cresol (1:1:1, by vol.) was employed to suppress the side reaction, O-mesitylene-2-sulfonation of the Tyr residue. 相似文献
42.
43.
Prediction of Optimal Atrioventricular Delay in Patients with Implanted DDD Pacemakers 总被引:12,自引:0,他引:12
TOSHIYUKI ISHIKAWA SHINICHI SUMITA KAZUO KIMURA MIYAKO KIKUCHI MASAMI KOSUGE NAOMITSU KUJI TSUTOMU ENDO TERUYASU SUGANO TOMOHIKO SIGEMASA IZUMI KOBAYASHI OSAMU TOCHIKUBO TAKASHI USUI 《Pacing and clinical electrophysiology : PACE》1999,22(9):1365-1371
In patients with an implanted DDD pacemaker (PM), the atrial contribution may be interrupted by too short an atrioventricular (AV) delay, and filling time may be shortened by too long an AV delay. The AV delay at which the end of the A wave on transmitral flow coincides with complete closure of the mitral valve may be optimal. The subjects were 15 patients [70.3+/-12.3 (SD) years old] with an implanted DDD PM. Cardiac output (CO) and pulmonary capillary wedge pressure (PCWP) were measured by Swan-Ganz catheter. Transmitral flow was recorded by pulsed Doppler echocardiography. AV delay was prolonged stepwise by 25 msc. When the AV delay was set at 155+/-26 ms, the end of the A wave coincided with complete closure of the mitral valve. When the AV delay was prolonged 25, 50, 75, and 100 ms from this AV delay, the interval between the end of the A wave and complete closure of mitral the valve was prolonged 16+/-5, 39+/-6, 65+/-4 and 88+/-5 ms, respectively (r = 0.97, P<0.0001) and diastolic mitral regurgitation was observed during this period. Thus, the optimal AV delay may be predicted as follows: the slightly prolonged AV delay minus the interval between the end of the A wave and complete closure of the mitral valve. When the AV delay was set at 215 ms, there was a significant positive correlation between the predicted optimal AV delay (166+/-23 ms) and the optimal AV delay (CO: 161+/-26 msec, r = 0.93, P<0.0001, PCWP: 161+/-28 msec, r = 0.95, P<0.0001). In conclusion, optimal AV delay can be predicted by this simple formula: slightly prolonged AV delay minus the interval between end of A wave and complete closure of mitral valve at the AV delay setting. 相似文献
44.
Age-related endothelium-dependent vascular relaxation in rat thoracic aorta in response to colforsin
KAZUHIRO Mori YASUNOBU Hayabuchi YASUHIRO Kuroda YUTAKA Nakaya KOICHIRO Tsuchiya & HIDEKI Moritoki 《Pediatrics international》1999,41(6):673-681
BACKGROUND: Colforsin, a novel water-soluble forskolin derivative, increases intracellular cyclic AMP by direct stimulation of adenylate cyclase and has strong positive inotropic and vasodilative effects. However, it is not known whether colforsin causes nitric oxide (NO) release and enhances endothelium-dependent vascular relaxation. METHODS: We studied NO production and relaxation on exposure to colforsin in thoracic aorta from rats aged 4, 12 and 60 weeks. RESULTS: When a low concentration of colforsin was added to a solution bathing ring segments of aorta from 12-week-old rats, relaxation was greater in the ring segments with intact endothelium than in those from which the endothelium had been removed. A high concentration of colforsin induced the same degree of relaxation of ring segments with or without endothelium, probably by a direct effect on vascular smooth muscle cells. Production of NO in response to colforsin by cultured endothelial cells from 12-week-old rat aorta was demonstrated by the electron paramagnetic resonance spin trapping method. A low concentration of colforsin relaxed aortic segments with intact endothelium from 4-week-old rats more than those from 12-week-old or 60-week-old rats. Reversal of relaxation by NG-nitro L-arginine, an NO synthesis inhibitor, was most significant in arteries from 4-week-old rats. Production of NO after exposure to colforsin was greater in aortic segments from 4-week-old rats than older rats, as detected by an NO-selective electrode. CONCLUSIONS: Colforsin induces vasodilation in part by releasing NO from the endothelium in rat thoracic aorta. In addition to a direct vasodilative effect on the vascular smooth muscle cells, an endothelium-dependent vasodilative effect is also important in younger arteries. 相似文献
45.
目的 通过研究质子加速器 7Li(p,n)7Be 反应的中子特性,为研究和制作适用于硼中子俘获治疗(BNCT)的加速器中子源提供基础数据。方法 加速质子使其轰击Li靶后产生中子;通过金属箔活化法,测量中子与In箔发生阈值反应后放出的γ射线;然后计算出In箔的放射性活度、加速器反应后放出中子的注量和反应的微分截面。结果 质子加速轰击Li靶后,在不同方向产生不同能量和注量的中子。加速器电压分别为3.0、2.8和2.6 MV,出射中子与入射质子束的方向一致时, 7Li(p,n)7Be 反应的微分截面约为50 mb/mr;夹角为60°时,反应的微分截面减小到30 mb/mr左右。由于部分中子与其他金属原子等发生弹性散射而射向后方,提高了这一范围内In箔的比放射性活度,影响了其微分截面的准确性。结论 用金属箔活化法测定中子简便易行,可同时测得多个方向的中子分布,但需对中子与其他金属弹性散射产生的影响进行进一步的研究; 7Li(p,n)7Be 反应后发射出的中子经慢化后,能得到适于BNCT治疗的热中子和超热中子;若作为BNCT的中子源,加速器的质子束流需达到10 mA。 相似文献
46.
目的 用18F亲电反应法,研究一种方便、迅速的18F标记氨基酸衍生物的方法。方法 标记过程分三步进行:①加速器内20Ne (d,α)18F反应合成18F2气体;②18F2气体通过特制的反应柱,转化为CH3COO18F;③CH3COO18F与氨基酸衍生物直接反应,得到相应的标记物。结果 整个标记过程约为45min,放射性产额约60%,放射化学纯度>95%,pH值约为7,无菌性和热源实验均为阴性,这些结果保证了进一步动物实验和临床应用的可行性。结论 18F亲电反应法是一种简单易行的标记氨基酸衍生物的方法。 相似文献
47.
HIDEO SAKAMOTO KATSUYUKI SAITO TAKESHI SHICHIZYO KIMIYASU ISHIKAWA ATUSHI IGARASHI HIDEKI YOSHIDA 《International journal of urology》2006,13(8):1073-1078
AIM: We assessed the value of scrotal color Doppler ultrasonography as a routine examination in infertile men. METHODS: Color Doppler ultrasonography was performed in 545 infertile men with a mean age of 35.8 years to detect intrascrotal abnormalities. Findings were compared with those of physical examination. RESULTS: Intrascrotal abnormalities were detected by ultrasonography in 65.3% of patients. Of 374 abnormalities, 58.3% were undetected by physical examination. Left varicocele was found in 313 patients (57.4%); testicular microlithiasis in 30 (5.5%); epididymal cyst in 21 (3.9%); right varicocele in 4 (0.8%); and testicular cysts in 3 (0.6%). One occurrence each (0.2%) was found for testicular tumor, intrascrotal hemangioma, and hydrocele of the spermatic cord. Compared to ultrasonography, sensitivity in detecting left varicocele by physical examination was 58.4%; specificity, 79.3%; accuracy, 67.3%; and positive predictive value, 79.3%. Venous diameters in the pampiniform plexus were 3 mm or more in 61.5% of 130 subclinical left varicoceles. Of 30 patients with testicular microlithiasis, 14 had varicocele, 2 had epididymal cyst,s 3 had a history of mumps orchitis, 1 had retractile testis, and 1 had a history of orchiectomy for contralateral testicular tumor. CONCLUSIONS: The routine Color Doppler ultrasonography is valuable for diagnosing scrotal abnormalities in infertile men, frequently detecting non-palpable lesions. 相似文献
48.
Katsushi CHIBA Mohammed E. RAHMAN Hitoshi ISHIKAWA Akira ENDO 《Congenital anomalies》1995,35(2):189-197
Abstract We examined the time and order of appearance of ossification centers of various bones in hand and foot in newborn Jcl:ICR mice by staining on days 22, 24, 26 and 28 post coitum (pc) by the alcian blue and alizarin red S staining procedure. The time of appearance of ossification centers of the carpal bones was from about day 22 pc to about day 26 pc, while the ossification centers of the tarsal bones appeared from preterm to about day 28 pc. The order of appearance of ossification centers of respective bones in mice was roughly similar to humans and rats. In carpal bones, ulnar sesamoid, centrale, fused 4th and 5th distal carpal and ulnare appeared first. Then, fused radiale and intermedium and 3rd distal carpal appeared. Finally, 1st distal carpal, 2nd distal carpal, and the last pisiform appeared. In the tarsal bones, fibulare and intermedium appeared first. Then, 1st distal tarsal, fused 4th and 5th distal tarsal and 3rd distal tarsal appeared. Finally, 2nd distal tarsal, centrale and tibiale appeared. In other mammals (humans, chimpanzees, rhesus monkeys and rats), it has been shown that the carpal and tarsal bone ossification of females starts earlier than that of males. However, in this study in mice, there was no such sex difference. The timing of ossification of carpal and tarsal bones in mice is of practical importance in determining the developmental status of hand and foot of mice in the field of neonatal teratology. 相似文献
49.
CHIEI TAKANAKA MAKOTO NONOKAWA TAKESHI MACHII SHOKOKU LEE HIDEKI KATO MASATO HARUNA SEITARO YABE 《Pacing and clinical electrophysiology : PACE》1992,15(11):2130-2133
The electrophysiological effects of combination therapy of mexiletine and propafenone were assessed using standard 12-Iead electrocardiogram (standard ECG), signal-averaged EGG (SAECG), and ambulatory ECG in 31 patients with ventricular arrhythmias. All patients underwent mexiletine monotherapy (M-mono), propafenone monotherapy (P-mono), low dose combination therapy (low M 4- P), and full dose combination therapy (full M + P). Full M + P increased the PQ interval and QRS duration to the same extent as P-mono did. Low M + P increased PQ interval and QRS duration to a lesser extent than P-mono and full M + P did. P-mono and full M + P significantly decreased root mean square (RMS) and increased f-QRS in SAECG, while M-mono and low M + P showed only a weak trend. SAECGs with late potentials increased in number with treatments; 9 in predrug control, 11 on M-mono, 15 on P-mono, 10 on low M + P, and 14 on full M + P. The percent suppression of frequent premature ventricular contractions (PVCs) (> 1,000/day) with M-mono, P-mono, low M + P, and full M + P were 46.4 ± 9.0,56.6 ± 10.4,64.4 ± 9.2, and 71.4 ± 7.1, respectively, and those of frequent couplets (> 10/day) were 58.3 ± 17.7, 62.6 ± 23.6, 87.5 ± 6.2, and 92.1 ± 4.0, respectively. Thus, full dose combination of mexiletine and propafenone exhibited the maximum antiarrhythmic efficacy without enhancement of effects on standard ECG and SAECG. Low dose combination therapy showed better antiarrhythmic efficacy in association with lesser effects on standard ECG and SAECG compared with propafenone monotherapy. 相似文献
50.
Higher cerebral dysfunction in a case with atypical multiple sclerosis with concentric lesions 总被引:1,自引:0,他引:1
CHIKAKO MORIOKA KEN NAMETA YOICHI KOMATSU TAKEHIKO TSUTIO HIDEKI KONDO 《Psychiatry and clinical neurosciences》1996,50(1):41-44
Abstract A patient with atypical multiple sclerosis (MS) with clear concentric structure was studied using high field magnetic resonance imaging (MRI). This case was considered to be Balo's concentric sclerosis. Magnetic resonance imaging showed diffuse multiple concentric demyelinating lesions in the bilateral centrum semiovales, which finally regressed with the necrotic lesions remaining when the patient was discharged. During his clinical course, he showed some higher cerebral dysfunctions, such as memory disturbance, constructual apraxia and acalculia. He was treated with glycerin, prednisone and rehabilitation; all of which were effective in his recovery. Over a 4 month period, the patient recoveredclinically, but some intellectual impairment remained. 相似文献