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521.
为研究环磷酰胺(CP)诱导的小鼠骨髓细胞微核率的时间-效应关系和剂量-反应关系,给小鼠一次腹腔注射不同剂量(按体质量计)CP(0、30、60、90 mg/kg)后,于不同时间(给药后12、24、36、486、0 h)、不同部位(胸骨与股骨)取材来观察小鼠骨髓细胞微核率的变化。结果表明,高、中、低三个剂量组的小鼠骨髓细胞微核率与0 mg/kg组相比较,其差异具有统计学意义(P<0.01),且4个剂量组之间两两比较也均有统计学意义(P<0.05),并表现出明显的剂量-反应关系;不同取样时间对小鼠骨髓细胞微核率的影响具有统计学意义(P<0.05),在36~48 h这个时间段能够观察到更高的微核率,通过线性回归的曲线拟合分析,以41 h取材最佳;胸骨取材与股骨取材之间的微核率差异无统计学意义(P>0.05)。环磷酰胺可作为诱导小鼠骨髓细胞微核的阳性对照,在一定范围内,具有剂量-反应关系和时间-效应关系。给小鼠一次腹腔注射量(按体质量计)60~90 mg/kg后36~48 h胸骨取材可取得较高微核率,结果满意。 相似文献
522.
本文以明胶、硝酸钙Ca(NO3)2和磷酸氢二铵(NH4)2HPO4为前驱体,初始Ca/P为1.5,制备了纯相的β-磷酸三钙.红外谱图和X射线晶体衍射结果表明,溶液中直接沉淀得到的产物为缺钙磷灰石,该产物在明胶浓度≥0.22 %(质量分数)时热转化为纯相的β-磷酸三钙.通过晶体尺寸计算和比表面积测定,缺钙磷灰石的晶体大小随着明胶用量的增加而变小.透射电镜结果显示溶液中直接沉淀的缺钙磷灰石呈针状形貌,经过高温煅烧后,针状的缺钙磷灰石将相互融合形成葡萄状的β-磷酸三钙.差热/热重结果表明,明胶与生成的缺钙磷灰石形成了化学键合,这将有助于吸附较多的水分子,随后水分子与缺钙磷灰石发生化学反应生成羟基磷灰石,羟基磷灰石继续与沉淀中的偏磷酸钙反应生成β-磷酸三钙.本文还研究了明胶对纯相β-磷酸三钙的生成机理. 相似文献
523.
Daniel E. Hagaman Jossana A. Damasco Joy Vanessa D. Perez Raniv D. Rojo Marites P. Melancon 《Molecules (Basel, Switzerland)》2021,26(2)
Patients with advanced prostate cancer can develop painful and debilitating bone metastases. Currently available interventions for prostate cancer bone metastases, including chemotherapy, bisphosphonates, and radiopharmaceuticals, are only palliative. They can relieve pain, reduce complications (e.g., bone fractures), and improve quality of life, but they do not significantly improve survival times. Therefore, additional strategies to enhance the diagnosis and treatment of prostate cancer bone metastases are needed. Nanotechnology is a versatile platform that has been used to increase the specificity and therapeutic efficacy of various treatments for prostate cancer bone metastases. In this review, we summarize preclinical research that utilizes nanotechnology to develop novel diagnostic imaging tools, translational models, and therapies to combat prostate cancer bone metastases. 相似文献
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526.
Esther Cascarosa Jason BeckerLorenzo Ferrante Cedric BriensFranco Berruti Jesús Arauzo 《Journal of Analytical and Applied Pyrolysis》2011,91(2):359-367
Nowadays, meat and bone meal produced in animal slaughterhouses and farms has become an important waste. Landfilling this residue means that its energy is lost. The pyrolysis of meat and bone meal produces a solid fraction which can be used as a fuel or as solid adsorbent, a liquid fraction with possible chemical applications and a low heating value gas.In this work, meat and bone meal has been pyrolyzed with a new technology, a mechanically fluidized reactor (MFR). This MFR is a stainless steel cylinder with 7.7 cm i.d., and an internal height of 15.6 cm. The meat and bone meal pyrolysis was carried out at 500 °C of temperature. The effect of several factors (mixer speed, heating rate and feed composition) on the product yields, bio-oil phases yield, bio-oil heating value and char heating value was studied. The amount of pure meat meal in the feed had a strong impact on product yields and compositions. The liquid yield, which has two phases, varies from 22 wt% to 52 wt% when the raw material fed changed from pure bone meal to pure meat meal. 相似文献
527.
以2-乙基咪唑、5-溴戊酸乙酯和PCl3为原料,合成了一种唑来膦酸衍生物:1-羟基-5-(2-乙基-1H-咪唑-1-基)戊烷-1,1-双膦酸(EIPeDP),将其与放射性元素99mTc(Ⅳ)进行标记形成配合物,研究了EIPeDP用量和反应体系pH值对标记率的影响。结果表明,当pH值为5~6、EIPeDP为5 mg、SnCl2.2H2O为100μg和Na99mTcO4为92.5 MBq时,可获得满意的标记率和放化纯(均大于97%)。标记物99mTc-EIPeDP具有良好的体外稳定性。动物体内实验表明,兔经注射99mTc-EIPeDP 1 h后获得的骨显像图质量明显优于99mTc-ZL和99mTc-MDP。表明99mTc-EIPeDP是一种制备简便、稳定性好和骨显像性能优异的新型放射显像剂。 相似文献
528.
Z. Tahmasebi Birgani Pamela Habibovic Lucas A. Kinard F. Kurtis Kasper Antonios G. Mikos John A. Jansen Sander C. G. Leeuwenburgh Jeroen J. J. P. van den Beucken 《Macromolecular bioscience》2013,13(6):777-788
The enzyme alkaline phosphatase (ALP) is added at different concentrations (i.e., 0, 2.5, and 10 mg · ml?1) to oligo(poly(ethylene glycol)fumarate) (OPF) hydrogels. The scaffolds are either incubated in 10 mM calcium glycerophosphate (Ca–GP) solution for 2 weeks or implanted in a rat subcutaneous model for 4 weeks. Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and alizarin red staining show a strong ability to form minerals exclusively in ALP‐containing hydrogels in vitro. Additionally, the calcium content increases with increasing ALP concentration. Similarly, only ALP‐containing hydrogels induce mineralization in vivo. Specifically, small (≈5–20 µm) mineral deposits are observed at the periphery of the hydrogels near the dermis/scaffold interface using Von Kossa and alizarin red staining.
529.
Gregory B. Kharas Anthony Scola III Kristen Mc Colough Allison Crawford Celeste A. Diener Gilbert Villaseñor 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(3):459-467
Unsaturated polyesters are prepared by transesterification polymerization of diethyl fumarate and 1,4‐cyclohexanedimethanol. The structure of the polyesters was characterized by FT‐IR and 1H‐ and 13C‐NMR spectroscopy. Semicrystalline morphology of the polymers is suggested by DSC analysis with Tg at 21°C and melting at 140°C. The thermogravimetric analysis indicated that the onset of degradation takes place at 300°C. The polyester's structure has significant impact on the properties of the composites prepared by crosslinking the fumarate double bonds with N‐vinyl pyrrolidone in the presence of an inorganic filler, calcium sulfate dihydrate, with the addition of a radical initiator, benzoyl peroxide, at ambient temperatures. The compressive strength and hydrolytic stability of the cement compositions was correlated with structure of the polyesters. 相似文献
530.
Natasha Irrera Alessandra Bitto Emanuela SantAntonio Rita Lauro Caterina Musolino Alessandro Allegra 《Molecules (Basel, Switzerland)》2021,26(13)
The endocannabinoid system (ECS) is a composite cell-signaling system that allows endogenous cannabinoid ligands to control cell functions through the interaction with cannabinoid receptors. Modifications of the ECS might contribute to the pathogenesis of different diseases, including cancers. However, the use of these compounds as antitumor agents remains debatable. Pre-clinical experimental studies have shown that cannabinoids (CBs) might be effective for the treatment of hematological malignancies, such as leukemia and lymphoma. Specifically, CBs may activate programmed cell death mechanisms, thus blocking cancer cell growth, and may modulate both autophagy and angiogenesis. Therefore, CBs may have significant anti-tumor effects in hematologic diseases and may synergistically act with chemotherapeutic agents, possibly also reducing chemoresistance. Moreover, targeting ECS might be considered as a novel approach for the management of graft versus host disease, thus reducing some symptoms such as anorexia, cachexia, fatigue, anxiety, depression, and neuropathic pain. The aim of the present review is to collect the state of the art of CBs effects on hematological tumors, thus focusing on the essential topics that might be useful before moving into the clinical practice. 相似文献