全文获取类型
收费全文 | 275篇 |
免费 | 8篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 9篇 |
妇产科学 | 5篇 |
基础医学 | 24篇 |
口腔科学 | 8篇 |
临床医学 | 57篇 |
内科学 | 5篇 |
皮肤病学 | 3篇 |
神经病学 | 5篇 |
特种医学 | 9篇 |
外科学 | 38篇 |
综合类 | 43篇 |
预防医学 | 40篇 |
眼科学 | 2篇 |
药学 | 19篇 |
中国医学 | 5篇 |
肿瘤学 | 17篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 2篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 12篇 |
2011年 | 20篇 |
2010年 | 16篇 |
2009年 | 22篇 |
2008年 | 11篇 |
2007年 | 18篇 |
2006年 | 12篇 |
2005年 | 16篇 |
2004年 | 8篇 |
2003年 | 12篇 |
2002年 | 12篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1978年 | 2篇 |
排序方式: 共有289条查询结果,搜索用时 15 毫秒
1.
In a series of experiments, we investigated the effects of pulsed low-level microwave irradiation on amphetamine-induced hyperthermia in the rat. Rats were irradiated in a 2,450-MHz cylindrical waveguide exposure system at 1 mW/cm2, 2 s pulses, 500 pps, average SAR of 0.6 W/kg. Acute (45 min) exposure to microwaves attenuated amphetamine-induced hyperthermia. This effect was blocked by pretreatment of the animals with the narcotic antagonist naloxone. In another experiment, rats were subjected to ten daily sessions of microwave exposure (45 min/session). On day 11, amphetamine-induced hyperthermia was studied in the animals immediately after a session of either microwave or sham exposure. Similar to the acute effect, amphetamine-induced hyperthermia was attenuated in rats irradiated with microwaves (unconditioned effect). In the sham-irradiated animals we observed a potentiation of the amphetamine-induced hyperthermia, which was a conditioned effect of microwaves. Thus, the conditioned effect (potentiation) was opposite in direction to the unconditioned effect (attenuation). No tolerance developed to the unconditioned effect after subchronic exposure. Furthermore, both conditioned and unconditioned effects of microwaves on amphetamine-induced hyperthermia could be blocked by treatment with naloxone. These data suggest that (1) microwave irradiation may activate endogenous opioids, which in turn alter the actions of psychoactive drugs, and (2) the effect of microwaves on drug action can be classically conditioned.
Offprint requests to: H. Lai 相似文献
2.
原发性肝癌经皮微波凝固治疗前后局部免疫活性细胞功能检测 总被引:18,自引:2,他引:16
目的:了解原发性肝癌经皮微波凝固治疗前、后局部免疫活性细胞功能变化。方法:C地38例病理诊断原发性肝癌,并接受超声导引下经皮微波凝固治疗的患者。分别治疗前及治疗后17d,超声导引下经皮用18G组织切割针于病灶及其周边肝组织取活检标本,取出的组织标本石蜡包埋,采用特异性单克隆抗体免疫组织化学染色,检测CD3^ 、CD56^ 、CD68^ 细胞及T淋巴细胞表面Fas配体;并在光镜下观察,用病理图像分析仪测量治疗前后、后阳性细胞直径、阳性细胞占单位面积百分比、T淋巴细胞Fas-L阳性表达率及治疗前后巨噬细胞内次级溶酶体变化。结果:治疗前肿瘤内仅有少量免疫细胞浸润,多数浸润的CD3^ 和CD56^ 细胞最大径小于10μm,CD68^ 细胞最大径小于18μm。治疗后病灶内浸润的CD3^ 、CD56^ 和CD68^ 细胞数量较治疗前明显增加,细胞体积明显增大(同治疗前相比CD3^ 细胞和CD56^ 细胞t和P值分别为3.48,-4.76和0.025,0.000,巨噬细胞t和P值分别为-2.46和0.028)。最大径大于10μm的CD3^ 和CD56^ 细胞分别由治疗前的10.4%和20.1%增至24.9%和30.2%,最大径大于18μm的CD68^ 细胞由10.2%增至33.4%。T淋巴细胞Fas-L阳性率由治疗前的7.2%增高至20.1%(P<0.01,巨噬细胞内次级溶酶体和T淋巴细胞内细胞器明显增多。结论:原发性肝癌经皮微波凝固治疗提高局部浸润免疫细胞的功能。 相似文献
3.
微波治疗涎腺粘液囊肿疗效观察 总被引:1,自引:1,他引:1
目的探讨微波治疗涎腺粘液囊肿的疗效。方法使用WB-100B型微波多功能治疗机对40例涎腺粘液囊肿患者进行治疗。术区常规消毒,用1%的卡因棉片置于囊肿表面及周围黏膜上表面麻醉后,将针状辐射探头直接插入囊腔内,进行烧灼治疗,至囊肿范围组织发白。所用微波频率为2450MHz,输出功率40W。根据囊肿大小酌情连续操作2~3次。术后常规口服抗生素3d。结果术中患者感到轻度疼痛(无需特殊处理)。术后7d复查无一感染,痂皮大部脱落,肉芽组织生长良好。15d创面愈合,口腔黏膜外形良好,无瘢痕挛缩、无畸形,随访1~2年无一复发,治愈率100%。结论微波治疗涎腺粘液囊肿,操作简便易行,疗效满意,值得推广应用。 相似文献
4.
大功率微波热疗联合化疗治疗晚期恶性肿瘤的临床研究 总被引:2,自引:0,他引:2
目的:观察大功率微波热疗联合化疗治疗晚期恶性肿瘤的近期疗效及副作用。方法:将53例晚期恶性肿瘤患者随机分为两组:一组接受传统的化疗,另一组接受化疗+热疗。热疗时肛温39.5~42.0℃,维持60m in,1次/周,4次为1个疗程。结果:热化疗组有效率(CR+PR)50.0%(13/26),化疗组有效率(CR+PR)22.2%(6/27),两者有显著性差异。KPS评分的提高两组间也有显著性差异。两组不良反应相似,主要为化疗所致的骨髓抑制和胃肠道反应,热化疗组未出现任何严重的热疗副作用。结论:热疗联合化疗能提高晚期恶性肿瘤的治疗有效率,改善生活质量,且不良反应轻,耐受性良好。 相似文献
5.
高频电波刀对宫颈病变的诊治价值 总被引:1,自引:2,他引:1
目的探讨高频电波刀环切术(LEEP)对各级宫颈上皮内瘤变(CIN)、宫颈中重度炎症、宫颈HPV感染及宫颈息肉的诊治效果。方法回顾性分析136例宫颈病变患者进行LEEP治疗后的随访资料。结果LEEP术后病理级别升高者18例,占13.2%,降级者38例,占27.9%,术前术后诊断符合率为58.8%,差异有统计学意义(P〈0.05)。136例LEEP手术历时平均11min,术中出血量平均15ml,术后出血发生率2.2%,宫颈管粘连发生率1.5%。CIN治愈率为96%,病变残留率4%,复发率2%。术后第12个月,HPV转阴率86.7%,持续阳性率13.3%。HPV转阴率术后逐步上升。结论LEEP术是治疗CIN的安全有效方法,对宫颈HPV清除具有较好疗效。 相似文献
6.
Objective: To explore the feasibility and effect of microwave in situ inactivation of malignant primary or metastatic tumors in the scapula. Methods: Seventeen patients (12 men, 5 women, mean age 48 years [range, 13–59 years]) with malignant primary or metastatic tumors involving the scapula were treated by microwave inactivation between June 1998 and February 2008. There were12 malignant primary bone and 5 metastatic tumors. In 14 cases Area Sl was involved and in 3 cases both Areas S1 and S2. All 17 cases were by making a dorsal arc‐ or “∩‐” shaped incision to expose the tumor, protecting the surrounding soft tissues with a copper grid, and then heated the tumors locally with 2450 MHz microwave to 50°C for 20 min, after which all or some of the necrotic tumor tissue was removed, preserving the support role of the scapula. Results: The operation time was 60–180 min (mean 120 min) and blood loss was 300–1000 mL (mean 460 mL). No serious intraoperative or postoperative complications occurred in any patient. The patients were followed up for 3 months to 10 years (mean 4.2 years). Three patients with Ewing's sarcoma in the scapula had pulmonary, cerebral and systemic multiple metastases and died 8~24 months after surgery. Three patients with malignant fibrous histiocytoma died of pulmonary and systemic multiple metastases 10~22 months after surgery; one patient had recurrence 6 months after surgery and survived with tumor. Five patients with metastatic tumor in the scapula died of non‐scapular metastatic tumor 6~14 months after surgery. The other five patients with primary malignant bone tumors had no recurrence or metastasis during follow‐up. Three cases had restricted extension of the shoulder joint with unrestricted protraction and retroflexion after surgery. Conclusion: In situ microwave inactivation features simple surgery, reliable effects and patient acceptability, making it an ideal surgical method for malignant tumors in the scapula. 相似文献
7.
目的观察中药排毒养生胶囊联合微波针刺疗法治疗海洛因依赖临床戒毒疗效。方法将海洛因依赖患者113例随机分为单用中药组(57例)和中药配合微波针刺组(56例);采用阿片类戒断综合征量表评测两组对海洛因成瘾戒断综合征治疗效果。结果12d治疗观察显示:中药组和微波针刺组临床脱毒率均为100%,但微波针刺组脱毒达标时间为第2日,中药组为第3日;戒断症状分项比较结果:微波针刺组对肌骨疼痛、抑郁心境、睡眠障碍主显症状控制效果明显优于中药组(P〈0.05)。结论中药联合微波针刺治疗海洛因急性脱毒期戒断综合征效果良好。 相似文献
8.
A 4-element array of coherently driven dipole microwave antennae produces a hot spot in the central region of the implanted volume and cold spots in the peripheral regions of the implant. Conversely, an incoherently driven array of antennae predominantly heats peripheral (along the antennae) regions of the implant. These two modes of feeding the antennae are complementary in a sense that the cold zones obtained with the coherently driven antennae coincide with the hot zones obtained with the incoherently driven antennae and vice versa. The SAR distributions resulting from mixing these modes of feeding (mixed-mode technique) were studied theoretically and experimentally. A theoretical model that allowed calculation of SAR distributions of a 4-element array of microwave antennae fed coherently, incoherently or using a mixed-mode technique was developed in this work. The goal of the theoretical study was to determine the proper mix of the coherent and incoherent modes of feeding the antennae such that the adequately (enclosed within a 50% isoSAR surface) heated volume was maximized. In experimental studies, the antennae were driven in a cyclical manner with a duty cycle equal to the weight of the coherent mode in the mix. The duty cycle was defined as the ratio of the time the antennae were driven coherently to the total duration of the cycle. To facilitate the periodical change from the coherent to incoherent feeding, a special electromechanical switch was developed. This switch allowed a wide range of variation of the duty cycle and cycle period. Theoretical and experimental studies have demonstrated that, if the relative weight of the coherent feeding in the mix-mode technique was 30% (duty cycle=0.3), the adequately heated volume was significantly larger and the SAR distribution was more uniform than those obtained with either the coherent or incoherent mode of feeding. 相似文献
9.
G. Shi 《International journal of hyperthermia》2013,29(6):625-636
The design and performance of annular antenna arrays with reflectors is presented. Arrays with three shapes of reflectors are analysed and simulated. These include the corner reflector, the circular reflector and the elliptical reflector. Power-density distributions within the annular arrays with and without reflectors are obtained by using the FDTD method. Also, the image theory method is used to verify the FDTD results in one case. By comparing the power-density distribution pattern of all four of the array designs (three with different reflectors, one without reflector), it is readily seen in each case that the array with reflectors yields better power-efficiency than the array without reflectors and the elliptical reflector yields the best performance. Comparisons of each array are made using 4, 6 and 8 antennae in the annular array. By using the optimized results of the elliptical reflector, the requirement for the input-power level to each antenna is greatly reduced. 相似文献
10.
Mobile phones signals are pulse-modulated microwaves, and EEG studies suggest that the extremely low-frequency (ELF) pulse modulation has sleep effects. However, 'talk', 'listen' and 'standby' modes differ in the ELF (2, 8, and 217Hz) spectral components and specific absorption rates, but no sleep study has differentiated these modes. We used a GSM900 mobile phone controlled by a base-station simulator and a test SIM card to simulate these three specific modes, transmitted at 12.5% (23dBm) of maximum power. At weekly intervals, 10 healthy young adults, sleep restricted to 6h, were randomly and single-blind exposed to one of: talk, listen, standby and sham (nil signal) modes, for 30 min, at 13:30 h, whilst lying in a sound-proof, lit bedroom, with a thermally insulated silent phone beside the right ear. Bipolar EEGs were recorded continuously, and subjective ratings of sleepiness obtained every 3 min (before, during and after exposure). After exposure the phone and base-station were switched off, the bedroom darkened, and a 90 min sleep opportunity followed. We report on sleep onset using: (i) visually scored latency to onset of stage 2 sleep, (ii) EEG power spectral analysis. There was no condition effect for subjective sleepiness. Post-exposure, sleep latency after talk mode was markedly and significantly delayed beyond listen and sham modes. This condition effect over time was also quite evident in 1-4Hz EEG frontal power, which is a frequency range particularly sensitive to sleep onset. It is possible that 2, 8, 217Hz modulation may differentially affect sleep onset. 相似文献