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91.
Carl Ganter 《Magnetic resonance in medicine》2006,55(1):98-107
Spoiled gradient echo sequences can only reach a homogeneous steady state if sufficiently strong crusher gradients are used in combination with RF phase cycling (RF spoiling). However, the signal depends quite sensitively on the chosen phase increment ? and—lacking analytical solutions—numerical simulations must be used to study the transient and steady‐state magnetization. For the steady state an exact analytical solution is derived, which holds for arbitrary sequence and tissue parameters. Besides a considerably improved computation performance, the analytical approach enables a better understanding of the complicated dependence on ?. For short repetition times (TR) the regime of small ? turns out to be particularly interesting: It is shown that the typical ?c, where RF spoiling starts to become effective, is essentially inversely proportional to T2. This tissue dependence implies that contrasts can be considerably larger with partial spoiling (? ≈ ?c) than with conventional RF spoiling (? ? ?c). As an example, the uptake of contrast agents in tissues is investigated. For typical parameters a considerably improved contrast enhancement can be obtained, both theoretically and experimentally. Magn Reson Med, 2006. © 2005 Wiley‐Liss, Inc. 相似文献
92.
《Journal of labelled compounds & radiopharmaceuticals》2006,49(12):1125-1130
Silymarin, the seed extract of milk thistle plant, Silybum marianum, has been used traditionally for the treatment of liver diseases and bile duct infection. Silybin 1 is the main bioactive components of silymarin, consisting a pair of diastereomers: Silybin A and Silybin B. In this article, we report the preparation of tritium‐labeled Silybin, which was accomplished by protection of Silybin as tritylated compound 2 and followed by oxidation of the primary alcohol to its corresponding aldehyde 3 . Subsequent reduction with NaB[3H]4 and deprotection of the trityl group provided the tritium‐labeled Silybin 4 . Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
93.
烧伤患者急性期反应物的变化及其临床意义 总被引:3,自引:0,他引:3
用环状免疫单扩散法观察了27例烧伤患者伤后46天以内血清急性期反应物前白蛋白、铜蓝蛋白、α_1酸性糖蛋白、α_1抗胰蛋白酶、转铁蛋白、C反应蛋白、纤维连接蛋白、补体成分C_4、C_(3c)、触珠蛋白的变化趋势、试图探讨它们与病情发生、发展规律之间的关系。结果:C反应蛋白、α_1酸性糖蛋白和α_1抗胰蛋白酶在所有患者都升高,提示烧伤后组织损伤逐渐加重及伴发炎症、感染的存在;白蛋白、铜蓝蛋白、转铁蛋白和纤维连接蛋白在伤后均明显降低,提示伤后的分解代谢增加、贫血及网状内皮系统功能降低与之有关;触珠蛋白伤后明显降低且死亡组更明显,提示其作为具有过氧化物酶活性的保护作用降低是促进死亡的原因之一;伤后补体C_4、C_(3c)在存活组升高而死亡组明显降低,因而可能被用于对患者病情和预后的判断。总之,观测急性期反应蛋白的变化规律,有助于及时发现患者病情的变化,以便临床及时采取相应措施。 相似文献
94.
采用人外周血淋巴细胞非程序DNA合成(UDS)试验和人胚肺成纤维细胞转化试验,测试了煤焦沥青烟雾提取物(ECTPF)对人体细胞的细胞毒性和遗传毒性。UDS试验结果表明,ECTPF可使淋巴细胞UDS值明显增加,并有剂量一反应关系。引起半数淋巴细胞死亡的浓度(LC50)为33.8μg/ml。细胞转化试验表明,ECTPF能诱发人胚肺成纤维细胞明显的形态学转化,且转化细胞具有部分恶性转化细胞的特性。引起半数人胚肺成纤维细胞生长抑制的浓度为41.3μg/ml。实验结果提示,ECTPF是一种具有细胞毒性和遗传毒性的物质。 相似文献
95.
Timo Laatikainen Henri Kurunmäki Aarne Koskimies 《Journal of assisted reproduction and genetics》1988,5(1):14-17
Of 70 cycles stimulated with clomiphene and human menopausal gonadotropin (hMG) for an in vitro fertilization-embryo transfer (IVF-ET) program, a short luteal phase of 11 days or less was found in 18. In this group the mean estradiol and progesterone levels were elevated in the early luteal phase. Despite the elevated initial values, progesterone levels fell rapidly at the mid luteal phase as a sign of premature luteolysis. The mean total amount of gonadotropin administered and the mean number of follicles punctured and of oocytes recovered did not show any significant difference between the groups of normal and short luteal phases. The present findings support the theory that hyperestrogenism in the early luteal phase may initiate the premature luteolysis observed in clomiphene-menopausal gonadotropin-stimulated cycles. 相似文献
96.
Ruprecht Nitschke Charles Pratt Michael Harris Jeffrey Krischer Teresa J. Vietti Holcombe Grier Willem Kamps Stuart Toledano 《Investigational new drugs》1992,10(2):93-96
CHIP (325 mg/M2), a second generation cisplatin derivative, was administered intravenously every 3 weeks to 85 pediatric patients with recurrent sarcomas (19), osteosarcomas (20), neuroblastoma (23), germ cell tumors (10), and other malignant tumors (7). Thirty-eight of them had been previously exposed to cisplatin. Partial remissions were only observed in 3 of 23 (13% SE=7%) patients having neuroblastoma. Severe thrombocytopenia (65%) and neutropenia (35%) were the dose limiting factors. 相似文献
97.
98.
A. M. Ibrahim 《Phytotherapy research : PTR》1992,6(3):155-157
The anthelmintic activity of aqueous extracts (0.25–50 mg/mL) from 14 plant species that represent seven families of the Sudanese flora was examined using the free living rhabditid nematode, Caenorhabditis elegans as a test organism. Extracts of Balanites aegyptiaca and Sesbania sesban were the most effective (LC50, 0.8 and 8.0 mg/mL, respectively). Extracts of Albizzia anthelmintica, Cymbopogen narvatus, Abrus precatorius, Rhyncosia minima, Striga hermonthica and Anogeissus leiocarpa (LC50, 9.5–84.6 mg/mL were less effective in this model test system. Extracts of six plant species, Albizzia malacophylla, Gardenia lutea, Physostigma mesoponticum, Salvadora persica, Xeromphis nilotica and Waltheria indica had no effect upon C. elegans survival. 相似文献
99.
目的研究T3期胃癌CD34与胃癌新生血管形成及淋巴结转移的关系.方法随机选取胃癌手术标本41例,其中T3N0M020例,T3N1M021例,分别进行特异性抗体免疫组化染色,并采用Image Pro Plus 5.0图像软件分析数据,计算胃癌组织CD34微血管密度(MVD)和其他相关抗体(CD44、Ⅳ型胶原、层黏蛋白)的表达,并进行统计学分析.结果CD34 MVD计数(CD34表达强度),在T3N0M0和T3N1 M0肿瘤组分别为43.10±18.22和56.24±28.36,两组比较有显著差异(P<0.05);CD44、Ⅳ型胶原、层黏连蛋白的表达强度,T3N0M0和T3N1M0肿瘤组比较无显著差异(P>0.05).结论CD34与T3期胃癌组织新生血管形成及淋巴结转移的关系密切,可作为诊断T3期胃癌淋巴结转移的参考指标. 相似文献
100.