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41.
白花前胡中白花前胡甙和Pd-C-I的分离和鉴定 总被引:9,自引:0,他引:9
从白花前胡(Peucedanum,praeruptorum)根中分得7个化合物,经化学方法和光谱分析分别鉴定为Pd-C-I(I),白花前胡甙(II),香草酸(III),没食子酸(IV),nodakenin(V),rutarin(VI)和isorutarin(VII)。II为新化合物,其化学结构为4-O-β-D-吡喃葡萄糖基-3-甲氧基苯丙酮,命名为白花前胡甙。I为首次从白花前胡中分得的线型二氢吡喃香豆素类化合物,这对前胡属植物化学分类学有一定意义。还利用2DNMR纠正了文献中关于化合物I和VII的个别碳信号归属的错误。 相似文献
42.
华北白前中的C21甾体类化合物 总被引:12,自引:0,他引:12
从华北白前(Cynanchum hancockianum)干燥根的乙醇提取物中分离鉴定了6个C21甾体化合物,其中白前甙元C(glaucogenin C,Ⅰ),白薇甙A(cynatratoside A,Ⅱ),白前甙元A(glaucogenin A,Ⅲ),脱水何拉得甙元(anhydrohirundigenin,Ⅳ)为已知化合物;华北白前甙元B(hancogenin B,Ⅴ),华北白前甙A(hancoside A,Ⅵ)为新化合物。提出了变型C21甾体甙元质谱的裂解规律。药理实验发现化合物Ⅱ具有一定的抗肿瘤活性,化合物Ⅵ具有一定的抗内毒素作用。 相似文献
43.
Turner DA; Alcorn FS; Shorey WD; Stelling CB; Mategrano VC; Merten CW; Silver B; Economou SG; Straus AK; Witt TR 《Radiology》1988,168(1):49-58
Detectability of breast cancer with magnetic resonance (MR) imaging versus xeromammography was quantitatively compared. MR images were obtained of breasts of 120 women who underwent xeromammography. T1 values were determined for masses larger than 2 cm. Cancer was histologically confirmed in 39 breasts and was considered excluded from 81 due to results of biopsy, cyst aspiration, or sonography or absence of change in xeromammographic findings over time. Images were blindly interpreted by three observers, and results were expressed as receiver operating characteristic curves. Detectability of breast cancer was substantially better with xeromammography than with MR imaging for all observers (P less than .03, 10(-6), and .001). On MR images, spiculation of a mass, distorted architecture, skin thickening, and nipple or skin retraction were specific but relatively insensitive indicators of cancer. Masses with smooth, distinct margins and signal intensity greater than that of fat on T2-weighted images were always benign. Other findings and T1 values were not diagnostically useful. The authors conclude that xeromammography is superior to MR imaging in detection of breast cancer. 相似文献
44.
Suspected leaking abdominal aortic aneurysm: use of sonography in the emergency room 总被引:5,自引:0,他引:5
Shuman WP; Hastrup W JR; Kohler TR; Nyberg DA; Wang KY; Vincent LM; Mack LA 《Radiology》1988,168(1):117-119
To determine the value of sonography in the emergent evaluation of suspected leaking abdominal aortic aneurysms, the authors examined 60 patients in the emergency department using sonography and a protocol involving advance radio notification from the ambulance; arrival of sonographic personnel and equipment in the triage room before patient arrival; and, during other triage activities, rapid sonographic evaluation of the aorta for aneurysm and of the paraaortic region for extraluminal blood. Sonographic findings were correlated with surgical results and clinical outcome. When performed under these circumstances, sonography was accurate in demonstrating presence or absence of aneurysm (98%), but its sensitivity for extraluminal blood was poor (4%). A combination of sonographic confirmation of aneurysm, abdominal pain, and unstable hemodynamic condition resulted in the correct decision to perform emergent surgery in 21 of 22 patients (95%). An abbreviated sonographic examination done in the emergency room can provide accurate, useful information about the presence of aneurysm; this procedure does not significantly delay triage of these patients. 相似文献
45.
TR. REUBEN U. OKAFOR 《Death Studies》2013,37(4):417-425
In D. Leviton's (1991) conception of horrendous death , a poorly managed environment can contribute to widespread mortality, and the deaths so caused can further create an environment for subsequent death. The African environment in particular is characterized by a number of "deathogenic" factors that must be understood and confronted by health educators committed to minimizing or eliminating the impact of horrendous death on the African continent. In this comment, the author argues that attention to characteristic but preventable forms of death in the African context can lead to greater public advocacy among African health educators, contributing to the physical and psychological wellbeing of the populations they serve. 相似文献
46.
47.
白花前胡中前胡香豆素D和前胡香豆素E的分离和鉴定 总被引:7,自引:0,他引:7
从中药白花前胡(Peucedanum Praeruptorum Dunn)根中分到5个化合物,经理化常数、波谱数据及化学反应分别鉴定为前胡香豆素D(I),Pd-Ib(II),前胡香豆素E(III),nodakenetin(IV)和scopoletin(V)。其中化合物I和III为两个新化合物,与巳知化合物凯林内酯的化学沟通确定了其绝对构型,其化学结构分别为3'(S),4'(S)-二乙酰氧基-3',4'-二氢邪蒿内酯(I)和3'(R)-惕各酰氧基-4'-酮基-3',4'-二氢邪蒿内酯(III)。化合物IV和V为首次从该植物中分离得到。通过DEPT,1H-1HCOSY和13C-1HCOSY等实验归属了II的碳氢信号。 相似文献
48.
49.
The human acute promyelocytic leukemia cell line HL-60 is induced by retinoic acid (RA) and N,N-dimethylformamide (DMF) to differentiate into cells having many of the functional and morphologic characteristics of mature granulocytes. With normal human phagocytic cells there is both superoxide anion (O2-) production and chemotaxis in response to chemoattractants such as N-formyl-methionyl-leucyl- phenylalanine (FMLP). We have now found that although HL-60 cells induced with RA alone produce O2- in response to 12-0-tetradecanoyl- phorbol-13-acetate (TPA) they are deficient in FMLP-stimulated O2- production and chemotaxis. In contrast, HL-60 induced either with DMF or with a combination of 10 nmol/L RA and a T cell-derived lymphokine, differentiation-inducing activity (DIA), produce O2- and exhibit chemotaxis in response to FMLP. The basis for these results appears to be the concentration of cell surface chemotactic peptide receptors. Thus, untreated HL-60 and HL-60 induced with either RA alone or DIA alone do not have measurable levels of FMLP receptors, whereas HL-60 induced with a combination of RA and DIA has 5,400 receptors per cell. HL-60 induced with RA and DIA plus 1 mumol/L dexamethasone have 25,000 receptors per cell and have greater chemotactic activity than HL-60 induced with the combination of RA and DIA. Thus, differentiation of HL- 60 to cells with many properties of normal phagocytes can be induced in vitro by physiologic substances. 相似文献
50.
Claire S Reader Sabari Vallath Colin W Steele Syed Haider Adam Brentnall Ami Desai Kate M Moore Nigel B Jamieson David Chang Peter Bailey Aldo Scarpa Rita Lawlor Claude Chelala Stephen M Keyse Andrew Biankin Jennifer P Morton TR Jeffry Evans Simon T Barry Owen J Sansom Hemant M Kocher John F Marshall 《The Journal of pathology》2019,249(3):332-342