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91.
HPLC法测定生物样品中淫羊藿苷的浓度   总被引:16,自引:1,他引:16  
以苯甲酸为内标,建立了HPLC测定动物血浆,尿,粪及心,肝,脾,肺,肾等组织匀浆中淫羊萑苷的浓度。色谱术五彩 用ZorbaxODS,流动相为四氢呋喃一水一冰醋酸(20:75:5),紫外检测波长270nm。  相似文献   
92.
Long considered merely a trophic and mechanical support to neurons, astrocytes have progressively taken the center stage as their ability to react to acute and chronic neurodegenerative situations became increasingly clear. Reactive astrogliosis starts when trigger molecules produced at the injury site drive astrocytes to leave their quiescent state and become activated. Distinctive morphological and biochemical features characterize this process (cell hypertrophy, upregulation of intermediate filaments, and increased cell proliferation). Moreover, reactive astrocytes migrate towards the injured area to constitute the glial scar, and release factors mediating the tissue inflammatory response and remodeling after lesion. A novel view of astrogliosis derives from the finding that subsets of reactive astrocytes can recapitulate stem cell/progenitor features after damage, fostering the concept of astroglia as a promising target for reparative therapies. But which biochemical/signaling pathways modulate astrogliosis with respect to both the time after injury and the type of damage? Are reactive astrocytes overall beneficial or detrimental for neuroprotection and tissue regeneration? This debate has been animating this research field for several years now, and an integrated view on the results obtained and the possible future perspectives is needed. With this Commentary article we have attempted to answer the above-mentioned questions by reviewing the current knowledge on the molecular mechanisms controlling and sustaining the reaction of astroglia to injury and its stem cell-like properties. Moreover, the cellular/molecular mechanisms supporting the detrimental or beneficial features of astrogliosis have been scrutinized to gain insights on possible pharmacological approaches to enhance astrocyte neuroprotective activities.  相似文献   
93.
This work was mainly focused on the processing-parameter-related microstructure and properties of ultrafine WC-10Co-0.4VC-0.5Cr3C2 cemented carbide. The samples were prepared via a spark plasma sintering (SPS) technique using nano WC and Co powders and the corresponding inhibitor VC and Cr3C2 powders. The influence of the processing process on the microstructure and mechanical properties of ultrafine-grained cemented carbide was investigated under different ball-milling times and sintering temperatures. The results showed that the grain size of WC decreased with increasing ball-milling time and decreasing sintering temperature and that the specific gravity of ε-Co increased with increasing ball-milling time. The hardness of cemented carbide increased with increasing ball-milling time and decreased with increasing sintering temperature due to the corresponding variation in grain size and the relative density of samples. The transverse fracture strength (TRS) was mainly affected by ball-milling time. The increase in ball-milling time led to decreased TRS values, mainly ascribed to the formation of WC particle agglomeration and the decreased WC-Co eutectic temperature. In addition, temperature changes were found to have little effect on TRS. The samples sintered at 1250 °C with a ball-milling time of 60 h had comprehensive mechanical properties. Their average grain size, relative density, hardness, and TRS were 355.5 nm, 95.79%, 2035.5 kg/mm2, and 2155.99 MPa, respectively.  相似文献   
94.
目的 检测MicroRNA-939(miR-939)和性别决定区相关HMG族盒蛋白4(Sry-related HMG box 4,SOX4)在先天性巨结肠(Hirschsprung's disease,HSCR)中的表达水平,评估miR-939在SOX4调控肠神经嵴前体细胞(enteric neural crest c...  相似文献   
95.
The primary plasma cell leukemia (pPCL) is a rare but aggressive variant of multiple myeloma (MM). Few studies have focused on the differences in the causes of death between pPCL and MM. This study aimed to compare and evaluate the causes of death of patients with pPCL and MM.The data were collected from the Surveillance Epidemiology, and End Results (SEER) database. The demographic characteristics, survival, and causes of death in pPCL and MM patients were evaluated and compared. The competing risk regression model was performed to predict the cause of death.Between 1975 and 2009, the overall mortality rate was 96.13% and 88.71% for pPCL and MM, and the median survival was 9 and 26 months, respectively. In pPCL, leukemia caused 45.05% of the deaths, followed by myeloma (38.83%). In MM, myeloma was the leading cause of death, accounting for 74.89% of the deaths. Older age at diagnosis was a risk factor for dying of leukemia in pPCL patients (HR = 1.49, 95% CI: 1.16–1.91), while older age at death was associated with reduced risk (HR = 0.67, 95% CI: 0.52–0.86). Although the survival of pPCL patients increased with time periods of diagnosis since 1975 to 2009, the risk of dying of leukemia increased with the periods. For MM, most of the demographic characteristics were found to have independently predicting influence on the cause of death.Patients with pPCL and MM had distinct causes of death. Leukemia was the leading and the most serious cause of death in pPCL patients. The demographic factors could not predict the causes of death in pPCL. More large-scale and multi-center studies are needed to evaluate the effect of novel agents in pPCL patients, especially for patients who have progressed to leukemia.  相似文献   
96.
皮肤抗老化领域的细胞治疗技术自问世以来,经历多次更新和优化,目前临床上公认安全性和效果较好的细胞治疗制剂包括脂肪干细胞及其培养基提取物、成纤维细胞、皮肤间充质干细胞以及富血小板浓缩物、富血小板血浆制剂等.然而,针对这些制剂的作用机制及优缺点还缺乏系统的总结,本文将对此进行详细阐述.  相似文献   
97.
富血小板血浆(PRP)是人自体全血经离心后获得的血小板浓缩物,含有大量生长因子及蛋白质。PRP因其有助于组织再生、伤口愈合、瘢痕修复等作用,在骨科、皮肤科、口腔颌面外科、整形美容科等领域应用广泛,而在妇科领域应用迄今相对较少。最新研究结果显示,PRP具有促进子宫内膜和卵泡生长作用,在治疗薄型子宫内膜(TE)、改善子宫内膜容受性(ER)、恢复卵巢功能等方面取得较大进展,并为多种妇科疾病治疗提供新的研究方向和手段。笔者拟就PRP的制备及分类、在妇科疾病治疗中的应用及其前景展望等最新研究现状进行阐述。  相似文献   
98.
目的 采用HPLC法测定大鼠血浆中莽草酸的含量.方法 大鼠血浆样品经甲醇沉淀蛋白后,采用HPLC法测定血浆中莽草酸的含量.色谱柱为WondaCract ODS-2 (250 mm×4.6 mm,5μm),流动相为甲醇(3 mmol·L-1四庚基溴化铵)-5mmol· L-1磷酸(用1 mol· L-1 NaOH调pH5.8)(60∶40),检测波长220 nm,流速0.8 mL· min-1,柱温35℃.结果 血浆中莽草酸的线性范围为0.525 ~ 10.50 μg· mL-(r=0.9998),平均回收率为97.7% ~ 101.6%,日内、日间RSD均<15%.结论 所用方法简便、灵敏、结果准确,适用于测定生物样品中莽草酸的浓度.  相似文献   
99.
目的:采用HPLC-MS/MS法检测人体血浆中丙泊酚的浓度,并将该方法用于临床药动学研究。方法:采用Zorb-ax Eclipse XDB-C18(50 mm×4.6 mm,5μm)色谱柱分离;流动相为甲醇和0.1%氨水二元梯度洗脱系统;流速为0.3 mL.min-1;通过电喷雾离子化电离源(ESI),采用负离子检测。结果:线性范围为0.010~12μg.mL-1,相关系数≥0.99,定量下限为0.010μg.mL-1。日内及日间精密度不高于15%,准确度的相对误差(RE)在-2.0%~5.0%。药代动力学符合三室模型,清除率为0.029 L.min-1.kg-1,中央室分布容积为0.60 L.kg-1,血药浓度消除半衰期t1/2α为0.84 min,t1/2β为6.7 min,t1/2γ为128.7 min。结论:该方法高效、灵敏,特异性强,准确度、精密度好,适用于丙泊酚药物动力学研究。  相似文献   
100.
Plasma treatment on a zirconia surface prevents bacterial contamination and maintains osteoblast activity. To assess the degree of adhesion of Porphyromonas gingivalis on a zirconia surface after non-thermal plasma (NTP) treatment, specimens were treated with plasma for 60, 300, and 600 s, after which P. gingivalis was inoculated onto the surface and incubated for 48 h. To assess osteoblast activity after NTP treatment, osteoblasts (MC3T3-E1) were dispensed onto the specimens contaminated with P. gingivalis immediately after NTP for 60 and 120 s, followed by incubation for 48, 72, and 96 h. P. gingivalis was cultured after 60 s of NTP treatment of zirconia. The NTP and control groups showed no significant difference (p = 0.91), but adhesion was significantly increased following NTP treatment for 300 s or longer (300, 600 s groups) (p < 0.05). After NTP treatment of P. gingivalis-contaminated zirconia, osteoblast activity significantly increased at 72 and 96 h (I60 and I120 s group) in the groups treated with plasma (p < 0.017). Application of NTP to dental zirconia implants for 60 s not only inhibits the proliferation of P. gingivalis, which causes peri-implantitis but also increases osseointegration on zirconia surfaces contaminated with P. gingivalis.  相似文献   
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