全文获取类型
收费全文 | 149篇 |
免费 | 12篇 |
国内免费 | 1篇 |
专业分类
基础医学 | 3篇 |
口腔科学 | 11篇 |
临床医学 | 5篇 |
内科学 | 3篇 |
神经病学 | 11篇 |
特种医学 | 46篇 |
外科学 | 2篇 |
综合类 | 3篇 |
预防医学 | 21篇 |
药学 | 20篇 |
中国医学 | 2篇 |
肿瘤学 | 35篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 16篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 25篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 13篇 |
2006年 | 5篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有162条查询结果,搜索用时 15 毫秒
11.
BPA used in BNCT has a similar structure to some essential amino acids and is transported into tumor cells by amino acid transport systems. Previous study groups have tried various techniques of loading BPA to increase intracellular boron concentration. CHO-K1 cells demonstrate system L (LAT1) activity and are suitable for specifying the transport system of a neutral amino acid. In this study, we examined the intracellular accumulation of boron in CHO-K1 cells by amino acid transport control, which involves co-loading with L-type amino acid esters. Intracellular boron accumulation in CHO-K1 cells showed the greatest increased upon co-loading 1.0 mM BPA, with 1.0 mM l-Tyr-O-Et and incubating for 60 min. This increase is caused by activation of a system L amino acid exchanger between BPA and l-Tyr. The amino acid esters are metabolized to amino acids by intracellular hydrolytic enzymes that increase the concentrations of intracellular amino acids and stimulate exchange transportation. We expect that this amino acid transport control will be useful for enhancing intracellular boron accumulation. 相似文献
12.
胶质瘤细胞系摄取BPA实验研究 总被引:2,自引:0,他引:2
目的 探讨孵育时间和细胞周期对胶质瘤细胞摄取BPA(p boronophenylalanine)的影响 ,进一步阐明BPA的胶质瘤细胞选择性作用机制。方法 将C6 ,BT 32 5 ,SHG 4 4胶质瘤细胞和原代大鼠星形胶质细胞培养在含BPA的培养液中 ,分别培养 4h、8h、12h、16h、2 0h和 2 4h后 ,采用感应耦合等离子体原子发射光谱 (ICP AES)法测定细胞内硼的含量。培养 2 4h后 ,流式细胞仪分选G0 /G1和G2 /M期的细胞 ,ICP AES法分别测定细胞内硼的水平。结果 三种胶质瘤细胞在每个检测时间点的细胞内硼含量均显著高于对照组胶质细胞 (P <0 .0 1)。三种胶质瘤细胞G2 /M期与G0 /G1期相比硼含量均明显增高 (P <0 .0 5 ) ,而星形胶质细胞两期差异不明显。C6、SHG 4 4和BT 32 5与星形胶质细胞G0 /G1期的硼浓度比分别为 1.4 6、1.5 1和 1.4 0 ,G2 /M期的硼浓度比分别为 3.6 5、3.96和3.76。结论 有丝分裂的过程可以加强胶质瘤对BPA的吸收 ,这一过程可能与胶质瘤细胞对BPA的主动运输有关。主动运输可能是BPA对胶质瘤选择性作用的基础 相似文献
13.
Boron neutron capture therapy (BNCT) is based on the nuclear reaction that occurs when a stable isotope, boron-10, is irradiated
with low energy (0.025 eV) thermal neutrons (n
th) to yield alpha (4He) particles and,7Li nuclei (10B+n
th→[11B]→4He+7Li+2.79 MeV). The success of BNCT as a tumoricidal modality is dependent on the delivery of a sufficient quantity of10B andn
th to individual cancer cells to sustain a lethal10B(n, α)7Li reaction. Boron delivery agents include a variety of compounds, such as the sulfhydryl containing polyhedral borane sodium
borocaptate (Na2B12H11SH, [BSH]), boronoporphyrins, boronophenylalanine, carboranyl uridines (CBU), and boronated monoclonal antibodies (MAb). The
present review will focus on three delivery systems that currently are under investigation in our laboratories, boronated
monoclonal antibodies, carboranyl uridines, and boronophenylalanine. Methodology has been developed to heavily boronate MAb
using a precision macromolecule, a “starburst” dendrimer, which can be linked to MAb by means of heterobifunctional reagents.
Although the resulting immunoconjugates retain their in vitro immunoreactivity, they lose their in vivo tumor localizing properties
and accumulate in the liver. In order to obviate this problem, work is now in progress to produce bispecific MAb, which can
simultaneously recognize a tumor-associated antigen and a boronated macromolecule. Boron containing, nucleosides are potential
vehicles for incorporating boron compounds into nucleic acids of neoplastic cells. For this purpose, carboranyl uridines have
been synthesized with the boron moiety on either the pyrimidine base or on the carbohydrate component. Although such structures
appear to be avidly taken up and retained by tumor cells in vitro, only the 5-carboranyl-nucleosides are converted biologically
to the nucleotide. There is no evidence, however, that the latter are incorporated into nucleic acids. Other carboranyl nucleosides
currently are being synthesized that may have better tumor localizing properties. The potential use of boronophenylalanine
as a capture agent for the treatment of melanoma metastatic to the brain also is under investigation. A nude rat model has
been developed using human melanoma cells that are stereotactically implanted into the brain. BNCT-treated animals have either
had prolonged survival times or continue to live compared to control rats that invariably died of their tumors, thereby suggesting
therapeutic efficacy. 相似文献
14.
铝 硅 硼与慢性肾衰的关系研究 总被引:1,自引:0,他引:1
为了解尿毒症及血液透析与血清微量元素的关系,用等离子体发射光谱仪检测10例未透析尿毒症患者、10例透析尿毒症患者、25例健康对照者血清Fe、Al、Si、B、Ca、Mg、As、Mo、Sb、Se、Tl含量。结果:透析组与未透析组年龄、肾功能指标、Hb、mBp、Ch、TG、HDL、LDL均无显著性差别;两组患者血清B、Si均比正常显著升高,血清Fe均比正常显著下降;血清Al、Mg仅在透析组比正常显著升高;透析组与未透析组比较仅Al、Mg显著升高,其余元素无显著性差别;血清B、Si均与BuN显著正相关,与Hb显著负相关。提示透析可增加血清Al、Mg含量。B、Si升高可能对肾脏有直接毒性。B可能与尿毒症神经系统损害有关。Si可抑制透析铝痴呆症的发展。 相似文献
15.
Glyn R. Wellum Robert G. Zamenhof Eugene I. Tolpin 《International journal of radiation oncology, biology, physics》1982,8(8):1339-1345
The possibility of achieving a therapeutically useful tissue boron distribution for boron neutron capture therapy (BNCT) of cerebral gliomas with boron loaded tumor-specific antibodies is discussed. Using a theoretical tumor-immunological model and RBE dose-depth calculations, the effects of various parameters, e.g. antibodyantigen association constant, antigen site density, number of boron atoms per antibody molecule, etc., on the advantage depth, a relative measure of the resulting radiation dose distributions, are determined. It is shown that with this model a maximum in the advantage depth as a function of the blood boron concentration occurs, the position of which is dependent on the value of the parameters used. Frequently this maximum corresponds to a blood boron-10 concentration range of between 0.1 to 0.5 μg10B/g blood. It is concluded that given the pharmacodynamic properties of potentially useful antibody preparations for this type of tumor therapy, advantage depths significantly greater than those obtainable with existing “blood-brain-barrier” compounds are not likely to be easily achieved. 相似文献
16.
Kageji T Nagahiro S Matsuzaki K Mizobuchi Y Toi H Nakagawa Y Kumada H 《International journal of radiation oncology, biology, physics》2006,65(5):1446-1455
PURPOSE: To clarify the correlation between the radiation dose and clinical outcome of sodium borocaptate-based intraoperative boron neutron capture therapy in patients with malignant glioma. METHODS AND MATERIALS: The first protocol (P1998, n = 8) prescribed a maximal gross tumor volume (GTV) dose of 15 Gy. In 2001, a dose-escalated protocol was introduced (P2001, n = 11), which prescribed a maximal vascular volume dose of 15 Gy or, alternatively, a clinical target volume (CTV) dose of 18 Gy. RESULTS: The GTV and CTV doses in P2001 were 1.1-1.3 times greater than those in P1998. The maximal vascular volume dose of those with acute radiation injury was 15.8 Gy. The mean GTV and CTV dose in long-term survivors with glioblastoma was 26.4 and 16.5 Gy, respectively. A statistically significant correlation between the GTV dose and median survival time was found. In the 11 glioblastoma patients in P2001, the median survival time was 19.5 months and 1- and 2-year survival rate was 60.6% and 37.9%, respectively. CONCLUSION: Dose escalation contributed to the improvement in clinical outcome. To avoid radiation injury, the maximal vascular volume dose should be <12 Gy. For long-term survival in patients with glioblastoma after boron neutron capture therapy, the optimal mean dose of the GTV and CTV was 26 and 16 Gy, respectively. 相似文献
17.
Suzuki M Sakurai Y Masunaga S Kinashi Y Nagata K Maruhashi A Ono K 《International journal of radiation oncology, biology, physics》2006,66(5):552-1589
PURPOSE: To investigate the feasibility of boron neutron capture therapy (BNCT) for malignant pleural mesothelioma (MPM) from a viewpoint of dose distribution analysis using Simulation Environment for Radiotherapy Applications (SERA), a currently available BNCT treatment planning system. METHODS AND MATERIALS: The BNCT treatment plans were constructed for 3 patients with MPM using the SERA system, with 2 opposed anterior-posterior beams. The (10)B concentrations in the tumor and normal lung in this study were assumed to be 84 and 24 ppm, respectively, and were derived from data observed in clinical trials. The maximum, mean, and minimum doses to the tumors and the normal lung were assessed for each plan. The doses delivered to 5% and 95% of the tumor volume, D(05) and D(95), were adopted as the representative dose for the maximum and minimum dose, respectively. RESULTS: When the D(05) to the normal ipsilateral lung was 5 Gy-Eq, the D(95) and mean doses delivered to the normal lung were 2.2-3.6 and 3.5-4.2 Gy-Eq, respectively. The mean doses delivered to the tumors were 22.4-27.2 Gy-Eq. The D(05) and D(95) doses to the tumors were 9.6-15.0 and 31.5-39.5 Gy-Eq, respectively. CONCLUSIONS: From a viewpoint of the dose-distribution analysis, BNCT has the possibility to be a promising treatment for MPM patients who are inoperable because of age and other medical illnesses. 相似文献
18.
R G Fairchild V P Bond 《International journal of radiation oncology, biology, physics》1985,11(4):831-840
At least 8 classes of compounds are being evaluated in various laboratories around the world as possible vehicles for the transport of boron to tumor for neutron capture therapy (NCT). A parameter of major importance is the minimum concentration of boron needed in tumor in order to produce improved results in cancer therapy. Calculations are made here of the minimum boron content in tumor necessary for NCT. These estimations are obtained for various neutron beams, on the basis of therapeutic gain produced by the effective dose (absorbed dose X relative biological effect). The effects of repair are considered, in anticipation of having boronated bio-molecules with selective and long-term binding to tumor cells, thus allowing protracted irradiations. Pure epithermal neutron beams (free of significant fast neutron and gamma contamination) are found to offer major advantages, particularly when the effects of repair are included. The various boron compounds being investigated for NCT are evaluated on the basis of necessary minimum boron content in tumor. 相似文献
19.
T. Fujimoto T. Andoh T. Sudo I. Fujita M. Imabori H. Moritake T. Sugimoto Y. Sakuma T. Takeuchi H. Sonobe Alan L. Epstein T. Akisue M. Kirihata M. Kurosaka Y. Fukumori H. Ichikawa 《Applied radiation and isotopes》2011,69(12):1713-1716
Clear cell sarcoma (CCS), a rare malignant tumor with a predilection for young adults, is of poor prognosis. Recently however, boron neutron capture therapy (BNCT) with the use of p-borono‐L‐phenylalanine (BPA) for malignant melanoma has provided good results. CCS also produces melanin; therefore, the uptake of BPA is the key to the application of BNCT to CCS. We describe, for the first time, the high accumulation of boron in CCS and the CCS tumor-bearing animal model generated for BNCT studies. 相似文献
20.
Y.C. Lin S.J. Wang H.P. Chung H.M. Liu F.I. Chou 《Applied radiation and isotopes》2011,69(12):1728-1731
This study attempted to increase the boron uptake of human head and neck carcinoma SAS cells for BNCT by using a gamma dose of 0.1 Gy for combined treatment. Intracellular boron concentrations in 25 μg B/mL medium of BPA treated and BPA combined gamma-irradiation treated SAS cells were 73.8±1.73 and 95.15±1.36 ppm, respectively. After neutron irradiation, the G2/M-phase cell populations of untreated, BPA treated and BPA combined gamma-irradiation treated SAS cells were 19.31±1.71%, 52.47±2.25% and 59.19±2.63%, respectively. Experimental results indicate that the low dose gamma radiation with combination BPA treatment has the highest killing rate after neutron irradiation. Capable of significantly increasing the G2/M arrest after neutron irradiation, the combined treatment of a low dose of gamma irradiation with 25 μg B/mL medium of BPA also provided a higher killing effect for BNCT. 相似文献