全文获取类型
收费全文 | 7107篇 |
免费 | 381篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 125篇 |
妇产科学 | 47篇 |
基础医学 | 893篇 |
口腔科学 | 122篇 |
临床医学 | 521篇 |
内科学 | 1633篇 |
皮肤病学 | 208篇 |
神经病学 | 461篇 |
特种医学 | 325篇 |
外科学 | 1180篇 |
综合类 | 21篇 |
预防医学 | 241篇 |
眼科学 | 274篇 |
药学 | 487篇 |
中国医学 | 21篇 |
肿瘤学 | 919篇 |
出版年
2023年 | 66篇 |
2022年 | 132篇 |
2021年 | 214篇 |
2020年 | 90篇 |
2019年 | 156篇 |
2018年 | 173篇 |
2017年 | 126篇 |
2016年 | 152篇 |
2015年 | 183篇 |
2014年 | 232篇 |
2013年 | 274篇 |
2012年 | 430篇 |
2011年 | 439篇 |
2010年 | 263篇 |
2009年 | 206篇 |
2008年 | 395篇 |
2007年 | 443篇 |
2006年 | 394篇 |
2005年 | 377篇 |
2004年 | 327篇 |
2003年 | 299篇 |
2002年 | 277篇 |
2001年 | 176篇 |
2000年 | 175篇 |
1999年 | 150篇 |
1998年 | 82篇 |
1997年 | 58篇 |
1996年 | 53篇 |
1995年 | 41篇 |
1994年 | 40篇 |
1993年 | 37篇 |
1992年 | 131篇 |
1991年 | 107篇 |
1990年 | 86篇 |
1989年 | 77篇 |
1988年 | 100篇 |
1987年 | 72篇 |
1986年 | 57篇 |
1985年 | 52篇 |
1984年 | 39篇 |
1983年 | 39篇 |
1982年 | 19篇 |
1979年 | 31篇 |
1977年 | 18篇 |
1975年 | 22篇 |
1973年 | 18篇 |
1972年 | 20篇 |
1970年 | 18篇 |
1969年 | 17篇 |
1968年 | 20篇 |
排序方式: 共有7530条查询结果,搜索用时 15 毫秒
81.
Association of cavernous malformation within vestibular schwannoma: immunohistochemical analysis of matrix metalloproteinase-2 and -9 总被引:1,自引:0,他引:1
A 65-year-old man presented with a rare case of cavernous malformation with hemorrhage located within vestibular schwannoma. He had suffered hearing impairment for 20 years, and was admitted to our hospital with vertigo and ataxic gait. Neurological examination revealed hearing loss, facial nerve paresis, and left cerebellar ataxia. Magnetic resonance imaging demonstrated a left vestibular schwannoma 35 mm in diameter, as well as a heterogeneous area associated with hypointense rim within the tumor, indicating intratumoral hemorrhage. Subtotal removal of the tumor together with the fibrously encapsulated hematoma was performed through a left retrosigmoid craniotomy. Histological examination of the surgical specimen revealed cavernous malformation within vestibular schwannoma. Immunohistochemistry for matrix metalloproteinase (MMP)-2 and -9, and tissue inhibitors of metalloproteinase-2 showed strong expression in the endothelial cells of the cavernous malformation, but not in the interstitial structures. His symptoms significantly improved after surgery and he underwent gamma-knife therapy for the residual tumor. Cavernous malformations may show dynamic characteristics such as repeated hemorrhage and de novo formation. MMP-2 and -9, which are implicated in angiogenesis and hemorrhage, may be upregulated in such tumors. 相似文献
82.
BACKGROUND: Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving CBF, but little is known about the change in CBF and its effect on neurologic status during the acute stage after revascularization. METHODS: 123I-IMP-SPECT was performed 1 and 7 days after STA-MCA anastomosis on 34 sides of 27 consecutive patients with adult-onset moyamoya disease (6 men, 21 women; 22-62 years old). The follow-up period ranged from 5 to 28 months (mean, 17.6 months). RESULTS: Thirteen patients (13 sides, 38.2%) suffered temporary neurologic deterioration due to hyperperfusion several days after surgery, which was sustained for several days (7.4 days in average). Postoperative magnetic resonance imaging/angiography showed the STA as a higher intensity signal than the preoperative finding without ischemic changes in all 13 patients. Postoperative SPECT revealed focal intense increase in CBF at the sites of anastomosis in all 13 patients. Eleven patients (32.4%) had transient focal neurologic deficit mimicking ischemic attack. Two patients (5.9%) had cerebral hyperperfusion syndrome associated with subarachnoid hemorrhage extending to the ipsilateral sylvian cistern. Symptoms were relieved by intensive blood pressure control, and no patients had permanent neurologic deficit or delayed neurologic deterioration during the follow-up period. CONCLUSIONS: Surgical revascularization including STA-MCA anastomosis is a safe and effective treatment for moyamoya disease, although temporary neurologic deterioration due to hyperperfusion could occur at a substantial rate. Routine CBF measurement is recommended for accurate diagnosis of postoperative hyperperfusion in moyamoya disease because its treatment is contradictory to that for ischemia. 相似文献
83.
Narisawa A Fujimura M Shimizu H Tominaga T 《No shinkei geka. Neurological surgery》2007,35(5):467-474
Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving cerebral blood flow (CBF). Seizure is known as a rare complication after revascularization for moyamoya disease, although its underlying mechanism is undetermined. We investigated the relationship between seizure attack and postoperative alteration in CBF in patients with moyamoya disease. CBF was routinely measured by N-isopropyl-p-[123I] iodpamphetamine (123I-IMP-SPECT) 1 and 7 days after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis on 64 sides of the 44 consecutive patients (male:female = 13:31, 2-62 years old) with moyamoya disease. Three patients (male:female = 1:2, 40-55 years old) suffered from seizure attack at 1 to 10 days after surgery. Two of the three patients manifested as seizures at 8-10 days after surgery and presented transient neurologic deteriolation before seizure. Postoperative SPECT revealed significant increase in CBF at the sites of the anastomosis in all three patients. Postoperative magnetic resonance imaging showed no ischemic changes, and magnetic resonance angiography showed the apparently patent STA-MCA anastomosis as thick high signal intensity sign in all three patients. The anatomical location and the temporal profile of hyperperfusion were completely in accordance with the focus of seizure attack. Intensive blood pressure control and the use of antiepileptic agents were instituted. The neurologic deficits were resolved and no seizure attack recurred in three patients. Seizure following STA-MCA anastomosis can be caused by hyperperfusion in patients with moyamoya disease. When seizure attacks occur, routine CBF measurement is recommended to differentiate hyperperfusion and ischemia, since the treatments for these conditions are contradictory. 相似文献
84.
Yamamoto N Unno N Mitsuoka H Saito T Miki K Ishimaru K Kaneko H Nakamura S 《Journal of vascular surgery》2002,36(6):1225-1230
OBJECTIVE: Interruption of incompetent perforating veins (PVs) is important for varicose vein surgery. The purpose of this study was to evaluate the preoperative and intraoperative diameter-reflux relationship of PVs and to evaluate the accuracy of preoperative duplex scanning in patients with varicose vein. METHODS: Patients with primary varicose veins were retrospectively investigated. Diameters and reflux of PVs were evaluated before surgery with color flow duplex ultrasound scan (US). During operation, the incompetent PVs were defined as those that showed an outward spurt of blood flow from the stump of the PVs. The sensitivity and specificity of US in the detection of reflux of PVs were calculated. Competent versus incompetent vein diameters were compared with the Student t test and one-way analysis of variance. RESULTS: Three hundred twenty-four calf PVs were detected in 304 legs of 175 patients with varicose vein. Diameters of competent and incompetent PVs confirmed with intraoperative finding averaged 2.67 +/- 1.10 mm (n = 28) and 3.28 +/- 1.01 mm (n = 58), respectively, at the upper calf (P =.012), 2.85 +/- 0.85 mm (n = 53) and 3.68 +/- 0.94 mm (n = 137), respectively, at the lower calf (p <.001), and 2.67 +/- 0.99 mm (n = 14) and 3.27 +/- 0.66 mm (n = 22), respectively, at the posterior calf (P =.036). The overall sensitivity of detection of reflux with US was 87.7%, and the specificity was 75.3%. Diameters of true-incompetent PVs and false-incompetent PVs were 3.59 +/- 0.94 mm (n = 199) and 3.31 +/- 0.84 mm (n = 24), respectively (P =.157). Diameters of true-competent PVs and false-competent PVs were 2.61 +/- 0.91 mm (n = 73) and 2.89 +/- 0.82 mm (n = 28), respectively (P =.158). CONCLUSION: Although the diameter of incompetent PVs was larger than that of competent PVs in both US and intraoperative findings, diameter measurement alone can not completely distinguish competent and incompetent PVs. The sensitivity and specificity of reflux obtained with US showed that the accuracy of preoperative duplex scanning to evaluate PV competency was not sufficient. 相似文献
85.
Kano H Mizuta K Sakakihara Y Kato H Miki Y Shibuya N Saito M Narita M Kawarasaki H Igarashi T Hashizume K Iwata T 《Transplantation》2002,74(4):543-550
BACKGROUND: Infection is a serious complication after liver transplantation. Immunization is one means of controlling infections. The objective of this study was to investigate the efficacy and safety of simultaneous administration of several vaccines before transplantation and the efficacy and safety of administration under immunosuppressive conditions after transplantation. METHODS: Fifty-eight patients who underwent living-related liver transplantation between April 1994 and March 2000 were included in this study. Simultaneous administration of a maximum of six vaccines was performed in a short period of time before transplantation. We also readministered vaccines to 15 patients with waning antibody titers after transplantation from June 1999. We investigated whether patients could seroconvert for measles, rubella, mumps, and varicella after immunization and how long antibody titers could be retained by measuring them several times throughout the period before and after transplantation. We also examined side effects caused by immunization. RESULTS: The rates of seroconversion against measles, rubella, mumps, and varicella after the pretransplantation vaccination were 82%, 100%, 90%, and 95%, respectively. The rates of reseroconversion against measles, rubella, mumps, and varicella after the posttransplantation revaccination were 85%, 100%, 100%, and 71%, respectively. Although antibody titers against these viruses generally waned with time, no patient exhibited any serious illness or side effects. CONCLUSION: Although 12 of 58 patients (21%) had an infection, pretransplantation immunization was effective to prevent serious illness, especially for the 6 months after transplantation. Posttransplantation live-vaccine administration under immunosuppressive conditions is effective and safe. 相似文献
86.
Miki Komatsu Masahiko Takahata Mitsuru Sugawara Yoh Takekuma Takashi Kato Manabu Ito Yuichiro Abe Tohru Irie Norimasa Iwasaki Akio Minami 《European spine journal》2010,19(12):2149-2155
Linezolid belongs to a new class of synthetic antimicrobial agent that is effective for a variety of methicillin-resistant
Staphylococcus aureus (MRSA) infections including bone and joint MRSA infections, but the effectiveness of linezolid for the treatment of MRSA
spine infection remains controversial. In this study, we investigated the diffusion of linezolid or vancomycin into normal
rabbit spinal tissues to determine the adequacy of linezolid for the treatment of spinal infection. The penetration efficacy
of linezolid into the annulus fibrosus, nucleus pulposus, and vertebral bone (10, 8, and 10%, respectively) was lower than
that of vancomycin (27, 11, and 14%, respectively). The penetration efficacy of linezolid into the bone marrow and iliopsoas
muscle (88 and 84%, respectively), however, was higher than that of vancomycin (67 and 9%, respectively). These results suggest
that linezolid is inadequate for the treatment of spine infection limited to the intervertebral disc, but may be effective
for the treatment of infection extending into the muscle and bone marrow, such as in vertebral osteomyelitis, iliopsoas abscess,
and postsurgical infection. 相似文献
87.
Miki Nagase 《Clinical and experimental nephrology》2010,14(4):303-314
Recent clinical and experimental studies have shown that aldosterone is a potent inducer of proteinuria and that mineralocorticoid receptor (MR) antagonists confer efficient antiproteinuric effects. We identified glomerular epithelial cells (podocytes) as novel targets of aldosterone; activation of MR injures podocytes possibly via oxidative stress, resulting in disruption of glomerular filtration barrier, proteinuria, and progression of chronic kidney disease. We also demonstrated that SHR/cp, a rat model of metabolic syndrome, was susceptible to podocyte injury and proteinuria. Aldosterone excess caused by adipocyte-derived aldosterone-releasing factors was suggested to underlie the nephropathy. High salt intake augmented MR activation in the kidney and exacerbated the nephropathy. Furthermore, we identified an alternative pathway of MR activation by small GTPase Rac1. RhoGDIα knockout mice, a model with Rac1 activation in the kidney, showed albuminuria, podocyte injury, and glomerulosclerosis. Renal injury in the knockout mice was accompanied by enhanced MR signaling in the kidney despite normoaldosteronemia, and was ameliorated by an MR antagonist, eplerenone. Moreover, Rac-specific inhibitor significantly reduced the nephropathy, concomitantly with repression of MR activation. In vitro transfection studies provided direct evidence of Rac1-mediated MR activation. In conclusion, our findings suggest that MR activation plays a pivotal role in the pathogenesis of chronic kidney disease in metabolic syndrome, and that MR may be activated both aldosterone dependently (via aldosterone-releasing factors) and independently (via Rac1). MR antagonists are promising antiproteinuric drugs in metabolic syndrome, although long-term effects on renal outcomes, mortality, and safety need to be established. 相似文献
88.
Laparoscopic and endoscopic cooperative surgery for gastrointestinal stromal tumor dissection 总被引:1,自引:1,他引:1
Hiki N Yamamoto Y Fukunaga T Yamaguchi T Nunobe S Tokunaga M Miki A Ohyama S Seto Y 《Surgical endoscopy》2008,22(7):1729-1735
BACKGROUND: Laparoscopic wedge resections are increasingly applied for gastric submucosal tumors such as gastrointestinal stromal tumor (GIST). Despite this, no defined strategy exists to guide the surgeon in choosing the appropriate laparoscopic technique for an individual case on the basis of tumor characteristics such as location or size. This study aimed to introduce a laparoscopic and endoscopic cooperative surgery (LECS) for gastric wedge resection that is applicable for submucosal tumor resection independent of tumor location and size. METHODS: Seven patients underwent LECS for the resection of gastric submucosal tumors. Both mucosal and submucosal layers around the tumor were circumferentially dissected using endoscopic submucosal dissection via intraluminal endoscopy. Subsequently, the seromusclar layer was laparoscopically dissected on the exact three-fourths cut line around the tumor. The submucosal tumor then was exteriorized to the abdominal cavity and dissected with a standard endoscopic stapling device. RESULTS: In all cases, the LECS procedure was successful for dissecting out the gastric submucosal tumor. In four of seven cases, the tumor was located in the upper gastric portion near the esophagogastric junction. The remaining three tumors were in the posterior gastric wall. In two cases, the tumors were more than 5 cm in diameter, and one was a GIST of the remnant stomach. The mean operation time was 169 +/- 17 min, and the estimated blood loss was 7 +/- 2 ml. The postoperative course was uneventful in all cases. CONCLUSIONS: The LECS procedure for dissection of gastric submucosal tumors such as GIST may be performed safely with reasonable operation times, less bleeding, and adequate cut lines. In addition, the success of the procedure does not depend on the tumor location such as the vicinity of the esophagogastric junction or pyloric ring. 相似文献
89.
Iwai T Abe S Miki Y Tokizaki T Matsuda K Wakimoto N Nakamura S Imamura T Matsushita T 《Archives of orthopaedic and trauma surgery》2008,128(8):763-767
Chondroblastoma located in the femoral head is one of the locations accounting for frequent recurrence. One of the reasons for this is the difficulty in obtaining appropriate surgical access to it for adequate removal of tumors. The authors present and illustrate a trapdoor procedure for the surgical treatment of chodroblastoma in the epiphysis of the femoral head. The surgical approach was made over the great trochanter and a trochanteric osteotomy was performed. The capsulotomy was made anteriorly and posteriorly, and the hip was dislocated anteriorly. Using a scalpel and an osteotome, the edges of a trapdoor segment were sharply dissected and the rectangular segment was lifted back to reveal an underlying subchondral tumor. The tumor tissue was thoroughly curetted and autologous cancellous bone was grafted. The trapdoor was replaced without any additional fixation, and the femoral head was reduced. The patient recovered good hip function without pain, and showed no recurrence of chondroblastoma at 5 years after surgery. The trapdoor procedure enabled sufficient access to complete curettage and autologous cancellous bone grafting for the chondroblastoma of the femoral head. This procedure proved to be a useful surgical approach for the treatment of chodroblastoma in the epiphysis of the femoral head in this case. 相似文献
90.
We report a case of upper urinary tract carcinoma which recurred 11 years after total cystectomy. A 52-year-old man presented with complaints of a sense of residual urine and terminal miction pain. Urinary cytology, cystoscopic examination and intravenous pyelography revealed normal findings. Twenty months later, because class V urinary cytologic findings were detected, transurethral biopsy was performed. Carcinoma in situ was diagnosed pathologically. Therefore, total cystectomy and ileal conduit urinary diversion were performed. The pathological diagnosis was transitional cell carcinoma, grade 3, pTis. At 127 months postoperatively, laboratory examination revealed an extremely high serum level of LDH (3,084 U/l). The right kidney was not visualized on IVP and computed tomography revealed a right renal irregular mass. On the suspicion of a renal pelvic tumor, right total nephroureterectomy was done. The pathologic diagnosis was renal pelvic adenocarcinoma and ureteral transitional cell carcinoma. The patient was treated postoperatively with 3 cycles of systemic chemotherapy and radiotherapy. The serum level of LDH returned to normal. However, one year later, the serum level of LDH elevated to 1,118 U/l. He died of retroperitoneal lymph node, left adrenal gland and pulmonary metastases. 相似文献