38 resultados para HSV TK


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Photoinduced anisotropy of a photochromic pyrrylfulgide/PMMA film was investigated by using two linearly polarized beams. Excitation by linearly polarized light induces into the film an optical axis that has the same polarization as the excitation beam. This causes a change of the transmittance and of the polarization state of the detection beam. With a microscope a matrix of 4x4 light spots with different polarizations were recorded in the pyrrylfulgide/PMMA film. If readout with non-polarized light, the matrix of light spots show no information pattern. However, when readout with differently polarized lights, different patterns can be displayed. The experiment demonstrates that pyrrylfulgide/PMMA films can be used to hide two differently polarized patterns, which may be applied in camouflage technology. (C) 2005 Optical Society of America.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

1、喜树碱类衍生物抗HIV构效关系与作用机制研究 喜树碱为传统的抗肿瘤药物。本研究对经过化学结构修饰的喜树碱类衍生物进行抗HIV活性及作用机制的研究,并初步探讨了其抗HIV构效关系。 我们对喜树碱类衍生物A系列化合物A1(喜树碱)、A2(10-羟基喜树碱)及A3(7-羟基喜树碱)进行了抗HIV活性检测。化合物A1和A3有较好的抗HIV-1和抗HIV-2活性,化合物A2没有显示抗HIV活性。表明化合物A1的C-10位上-OH基团修饰可能会降低抗HIV活性,化合物A1的C-7位上-CH2OH基团修饰和C-20位-CH3缺失可能会提高其抗HIV活性。对化合物A3和A1的抗HIV机制研究发现:二者对整合酶有一定的结合活性,对慢性感染H9/HIV-1ⅢB 和Jurkat/HIV-1ⅢB细胞中病毒复制没有抑制活性、不能阻断H9/HIV-1ⅢB与正常细胞间的融合,对重组的HIV-1蛋白酶和逆转录酶没有抑制活性。化合物A1和A3不具有选择性杀伤HIV-1ⅢB慢性感染的H9和Jurkat细胞系的作用。进一步进行化合物A3诱导 H9和H9/HIV-1ⅢB、Jurkat和Jurkat/HIV-1ⅢB的凋亡实验显示,化合物A3诱导感染HIV-1ⅢB和未感染病毒细胞的凋亡没有选择性。据此我们初步认为化合物A3和A1的抗HIV作用可能与抑制整合酶活性有关,该化合物可能还作用于其它靶点。 喜树碱类衍生物B系列中化合物B1为20(S)-O - [-O-( 1'-氧基-2',2',6',6'-四甲基哌啶-4'-丁二酸)]-20-喜树碱酯,化合物B2为20(S)-O - [-N-( 1'-氧基-2',2',6',6'-四甲基-1',2',5',6'-四氢吡啶酰胺)-4'-丙氨酸)]-20-喜树碱酯)。我们对化合物B1和B2进行了抗HIV活性检测。结果显示:化合物B2有较好的抗HIV-1和抗HIV-21、喜树碱类衍生物抗HIV构效关系与作用机制研究 喜树碱为传统的抗肿瘤药物。本研究对经过化学结构修饰的喜树碱类衍生物进行抗HIV活性及作用机制的研究,并初步探讨了其抗HIV构效关系。 我们对喜树碱类衍生物A系列化合物A1(喜树碱)、A2(10-羟基喜树碱)及A3(7-羟基喜树碱)进行了抗HIV活性检测。化合物A1和A3有较好的抗HIV-1和抗HIV-2活性,化合物A2没有显示抗HIV活性。表明化合物A1的C-10位上-OH基团修饰可能会降低抗HIV活性,化合物A1的C-7位上-CH2OH基团修饰和C-20位-CH3缺失可能会提高其抗HIV活性。对化合物A3和A1的抗HIV机制研究发现:二者对整合酶有一定的结合活性,对慢性感染H9/HIV-1ⅢB 和Jurkat/HIV-1ⅢB细胞中病毒复制没有抑制活性、不能阻断H9/HIV-1ⅢB与正常细胞间的融合,对重组的HIV-1蛋白酶和逆转录酶没有抑制活性。化合物A1和A3不具有选择性杀伤HIV-1ⅢB慢性感染的H9和Jurkat细胞系的作用。进一步进行化合物A3诱导 H9和H9/HIV-1ⅢB、Jurkat和Jurkat/HIV-1ⅢB的凋亡实验显示,化合物A3诱导感染HIV-1ⅢB和未感染病毒细胞的凋亡没有选择性。据此我们初步认为化合物A3和A1的抗HIV作用可能与抑制整合酶活性有关,该化合物可能还作用于其它靶点。 喜树碱类衍生物B系列中化合物B1为20(S)-O - [-O-( 1'-氧基-2',2',6',6'-四甲基哌啶-4'-丁二酸)]-20-喜树碱酯,化合物B2为20(S)-O - [-N-( 1'-氧基-2',2',6',6'-四甲基-1',2',5',6'-四氢吡啶酰胺)-4'-丙氨酸)]-20-喜树碱酯)。我们对化合物B1和B2进行了抗HIV活性检测。结果显示:化合物B2有较好的抗HIV-1和抗HIV-2活性,而化合物B1的抗HIV活性差。表明化合物B1的C-4’位-CH2被-NH取代,同时C-3’位-CH3修饰可能会提高其抗HIV活性。对化合物B2的抗HIV机制研究发现,化合物B2对慢性感染H9/HIV-1ⅢB细胞中病毒复制没有抑制活性、不能阻断H9/HIV-1ⅢB与正常细胞间的融合,对HIV-1蛋白酶、重组的HIV-1逆转录酶及整合酶没有抑制活性。化合物B2不具有选择性杀伤HIV-1ⅢB慢性感染的H9细胞系的作用。化合物B2抗HIV的作用机制还需进一步研究。 2、HIV/AIDS患者疱疹病毒感染状况及性病患者的HIV感染状况分析 疱疹病毒是AIDS患者合并感染的常见病原体。引起人类疾病的8种疱疹病毒与HIV感染及AIDS进展、机会性感染、恶性肿瘤密切相关。为了解HIV/AIDS患者人类8型疱疹病毒感染状况,我们检测了30例AIDS患者、40例HIV携带者及70例正常对照的液标本中8型疱疹病毒感染状况。采用ELISA法检测单纯疱疹病毒1型(HSV-1)、单纯疱疹病毒2型(HSV-2)、水痘-带状疱疹病毒(VZV)和巨细胞病毒(CMV);采用PCR法检测EB病毒(EBV)、疱疹病毒6型(HHV-6)、疱疹病毒7型(HHV-7)及疱疹病毒8型(HHV-8)。结果显示,HIV/AIDS患者中HSV-1、HSV-2、VZV、CMV、HHV-6、HHV-8 阳性率均高于健康体检者,其中AIDS患者VZV感染率与HIV携带者有显著性差异;在AIDS患者中多种疱疹病毒共感染普遍存在,必须重视HIV/AIDS患者合并疱疹病毒感染的防治。 性病可促进HIV的传播,了解性病患者的HIV感染状况及临床特征具有重要的意义。在自愿接受HIV咨询检测的基础上,对临床确诊的412例性病患者进行HIV-1/2抗体检测,并对其临床特征进行分析研究。结果显示412例性病患者的HIV检出率为2.9%。性病患者中检出HIV阳性率依次为:尖锐湿疣(6.2%)、生殖器疱疹(4.2%)、梅毒(3.4%)、淋病(1.5%)及非淋菌性尿道炎(1.0%)。83.3%合并感染HIV的性病患者存在多性伴,商业性行为普遍存在,安全套使用率极低现象。感染HIV的尖锐湿疣及生殖器疱疹患者以频繁复发为突出表现,1例合并感染HIV的梅毒患者半年即进展为神经梅毒。性病患者是HIV感染的重要高危人群,危险性行为是其感染HIV和其它性病的主要原因,应该加强性病患者的HIV检测。对临床上频繁复发的尖锐湿疣及生殖器疱疹患者、快速进展的梅毒患者应高度怀疑合并HIV感染的可能。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

本文直接针对当前严重的世界性问题-病毒传染性疾病,开展了五种天然低聚糖及其硫酸酯衍生物的制备、抗病毒活性研究以及具抗疱疹病毒活性低聚糖硫酸酯作用机制的初步探讨。中药的结构修饰是中药现代化的重要内容,本研究的开展结合了药学、药理学和构效学,进一步丰富了硫酸酯化糖类抗病毒活性研究,有助于获得抗病毒活性新型药物以用于病毒引起的各类疾病,具有重要的理论和应用意义。1。分别从多花黄精以及与之在种属上有着由近及远关系的大玉竹、天冬、魔芋(酶解干粉)和香菇(子实体)中用类似程序提取了五种低聚糖样品,分别命名为Pcos、Pmos、Acos、Apkos、Leos。单糖组成分析、凝胶柱层析、红外光谱分析以及基体辅助激光解吸-飞行时间质谱分析的结果表明五种样品属于分子量比较接近、单糖组成各异、糖链骨架结构不同的低聚糖。这为后面不同糖链骨架结构的低聚糖硫酸酯的制备、探讨低聚糖硫酸酯衍生物糖链结构与抗病毒活性的关系建立了基础。从香菇子实体中用酶法制备低糖为首次报道。2。采用氯磺酸-吡啶法分别制备了五种天然低聚会糖的硫酸酯衍生物,分别命名为S-Pcos、S-Pmos、S-Acos、S-Apkos、S-Leos,经硫含量分析、Biol-Gel P4 凝胶柱层析、红外光谱分析证明该方法成功地向低聚糖中引入了硫酸基团,为开展天然低聚糖及其硫酸酯的抗病毒活性研究准备了必备的材料。3。利用细胞病变抑制法、中性红染色法、病毒空斑抑制法开展了五种低聚糖及其硫酸酯的体外抗HSV-2活性研究,结果都表明五种天然低聚糖本身没有抗HSV-2活性,除S-Acos之外的四种不同糖链骨架结构的低聚糖硫酸酯产生大小不同的活性, 说明硫酸酯低聚糖的抗病毒活性具有普遍的意义,这就大大扩大了药源,也为新的抗病毒活性药物筛选提供了新的思路和途径。S-Acos没有抗HSV-2活性,可能是因为低聚糖硫酸酯的抗病毒活性还存在硫酸基团以外的其它因素在起作用。五种低聚糖硫酸酯能抑制乙型肝炎抗原表达,说明低聚糖硫酸酯可能具有广谱抗病毒活性,有很大的应用前景。大玉竹、天冬、魔芋低聚糖及其硫酸酯的抗病毒活性研究未见报道。四种具抗HSV-2活性的低聚糖硫酸酯中,以S-Pmos的抗HSV-2活性最好,具有潜在抗病毒药物开发应用价值,值得进一步研究开发。4。初步探讨了低聚糖硫酸酯的抗病毒作用机制,由不同时间加药实验结果推测四种低聚糖硫酸硫酯具有类似的作用机制,可能作用于HSV-2与细胞的吸附阶段,不能抑制病毒在细胞内的复制过程;低聚糖硫酸酯的作用对象为病毒;对病毒毒力的影响实验和撤药实验说明四种低聚硫酸酯不能杀灭HSV-2,仅起抑制作用。作用机制的研究不仅进一步明确了四种低聚糖硫酸酯的抗HSV-2活性,还为今后开发和临床应用该类潜在性抗病毒药物提供了实验基础和依据。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

本学位论文主要研究一株放线菌发酵产物的抗肿瘤活性。先对该株放线菌进行活化培养,然后进行大批量发酵,发酵液经过冷冻离心,对离心得到的沉淀和上清液用不同极性的有机溶剂进行萃取,得到六个浸膏样品。对六个样品进行初步抗肿瘤活性检测。 然后对活性浸膏进行分离纯化和活性跟踪。本论文主要进行了如下的工作: 1、对菌种进行活化培养,利用该菌株在280C,200r.min-1条件下进行发酵实验,发酵时间为72h,发酵总量为15L。发酵液经过离心得到上清液和沉淀两部分。 2、分别用石油醚、乙酸乙酯、正丁醇萃取沉淀和上清液,得到编号为1—6的六个浸膏样品,对六个浸膏样品进行初步的细胞毒性和抗HepG2肿瘤活性实验,得出结论为5号样品活性最高。在没有分离纯化的情况下GI50达到0.76µg/mL。 3、对5号样品进行TLC实验,找出能够较好分离5号样品中各组分的溶剂组合,最后得出在氯仿:甲醇=8:1时分离效果较好。然后利用氯仿:甲醇=8:1的溶剂组合作为洗脱剂对5号样品进行过硅胶柱分离纯化并进行活性跟踪分离。 4、对分离纯化后得到的样品进行活性跟踪和结构分析。分离后得到样品A,在其浓度为10µg/ml时,抗肿瘤实验细胞的生长率为73.5%。在浓度为1.0mg/ml时,抗单纯疱疹病毒率(HSVⅡ)为74.5%。结构分析得知其分子式最可能为C41H43N8O4. This dissertation studied about the anti-tumor activity of an actinomycete fermentation product. First, we cultured the actinomycete. Second, we fermented it in large quantities, and then centrifuged the fermentation fluid; the next step is that we extract sedimentation and supernatant in different polar organic solvents, in turn to obtained six samples, which were detected about anti-tumor activity. Last, we purified active sample and tracked activity of it. We carried out the following research work: 1. Activation, culture and screening of the actinomyces was carried on. We used the screening strain to carry on the fermentation when the conditions are 280C,200r.min-1,the fermentation time is 72h. Fermentation fluid volume is 15L.And we obtained sedimentation and supernatant after fermentation fluid was centrifuged. 2. We used Petroleum ether, ethyl acetate, n-butanol separately to extract sedimentation and supernatant, and obtained six samples that were numbered 1-6. From the preliminary cell toxicity and the anti-tumor(HepG2) bioactivity experiment, we found that No.5 sample has the highest activity in the samples; the GI50 was 0.76µg/ml which has not been purified. 3. We Carried on TLC experiment on the No.5 sample, found the solvent composition that can separate each component of the No.5 sample. At last, we found that when the proportions are tri-chloromethane: methyl alcohol = 8:1, the Separation result was the best, and then we used the Solvent composition which proportion are tri-chloromethane: methyl alcohol = 8:1 as eluant to Purify No.5 sample by silica gel column. 4. We tracked the activity of pure sample obtained from Purification and analyzed structure of these substances. We got a compound A after separation, and the cell growth rate was 73.5% when its concentration was 10µg/ml. The anti-virus(HSVⅡ) rate was 74.5% when its concentration was 1.0mg/ml. We analyzed the Structure of A, and informed its molecular formula that was the most likely for C41H43N8O4.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We present results on the system size dependence of high transverse momentum di-hadron correlations at root s(NN) = 200 GeV as measured by STAR at RHIC. Measurements in d + Au, Cu + Cu and Au + Au collisions reveal similar jet-like near-side correlation yields (correlations at small angular separation Delta phi similar to 0, Delta eta similar to 0) for all systems and centralities. Previous measurements have shown Chat the away-side (Delta phi similar to pi) yield is suppressed in heavy-ion collisions. We present measurements of the away-side Suppression as a function of transverse momentum and centrality in Cu + Cu and Au + Au collisions. The suppression is found to be similar in Cu + Cu and An + An collisions at a similar number of participants. The results are compared to theoretical calculations based on the patron quenching model and the modified fragmentation model. The observed differences between data and theory indicate that the correlated yields presented here will further constrain dynamic energy loss models and provide information about the dynamic density profile in heavy-ion collisions. (C) 2009 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at root s = 200 GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of p(T) >= 5 GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high p(T).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

200 GeV corresponding to baryon chemical potentials (mu(B)) between 200 and 20 MeV. Our measurements of the products kappa sigma(2) and S sigma, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the root s(NN) dependence of kappa sigma(2). From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for mu(B) below 200 MeV.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We report the first three-particle coincidence measurement in pseudorapidity (Delta eta) between a high transverse momentum (p(perpendicular to)) trigger particle and two lower p(perpendicular to) associated particles within azimuth |Delta phi| < 0.7 in root s(NN) = 200 GeV d + Au and Au + Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Delta eta correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Delta eta. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We report on a measurement of the gamma(1S + 2S + 3S) -> e(+)e(-) cross section at midrapidity in p + p collisions at root s = 200 GeV. We find the cross section to be 114 +/- 38(stat + fit)(-24)(+23)(syst) pb. Perturbative QCD calculations at next-to-leading order in the color evaporation model are in agreement with our measurement, while calculations in the color singlet model underestimate it by 2 sigma. Our result is consistent with the trend seen in world data as a function of the center-of-mass energy of the collision and extends the availability of gamma data to RHIC energies. The dielectron continuum in the invariant-mass range near the gamma is also studied to obtain a combined yield of e(+)e(-) pairs from the sum of the Drell-Yan process and b-(b) over bar production.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Charged-particle spectra associated with direct photon (gamma(dir)) and pi(0) are measured in p + p and Au + Au collisions at center-of-mass energy root(S)(NN) = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. A shower-shape analysis is used to partially discriminate between gamma(dir) and pi(0). Assuming no associated charged particles in the gamma(dir) direction ( near side) and small contribution from fragmentation photons (gamma(frag)), the associated charged-particle yields opposite to gamma(dir) (away side) are extracted. In central Au + Au collisions, the charged-particle yields at midrapidity (vertical bar eta vertical bar < 1) and high transverse momentum (3 < (assoc)(PT) < 16 GeV/c) associated with gamma(dir) and pi(0) (vertical bar eta vertical bar < 0.9, 8 < (trig)(PT) < 16 GeV/c) are suppressed by a factor of 3-5 compared with p + p collisions. The observed suppression of the associated charged particles is similar for gamma(dir) and pi(0) and independent of the gamma(dir) energy within uncertainties. These measurements indicate that, in the kinematic range covered and within our current experimental uncertainties, the parton energy loss shows no sensitivity to the parton initial energy, path length, or color charge.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Yields, correlation shapes, and mean transverse momenta p(T) of charged particles associated with intermediate-to high-p(T) trigger particles (2.5 < p(T) < 10 GeV/c) in d + Au and Au + Au collisions at root s(NN) = 200 GeV are presented. For associated particles at higher p(T) greater than or similar to 2.5 GeV/c, narrow correlation peaks are seen in d + Au and Au + Au, indicating that the main production mechanism is jet fragmentation. At lower associated particle pT < 2 GeV/c, a large enhancement of the near- (Delta phi similar to 0) and away-side (Delta phi similar to pi) associated yields is found, together with a strong broadening of the away-side azimuthal distributions in Au + Au collisions compared to d + Au measurements, suggesting that other particle production mechanisms play a role. This is further supported by the observed significant softening of the away-side associated particle yield distribution at Delta phi similar to pi in central Au + Au collisions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Balance functions have been measured for charged-particle pairs, identified charged-pion pairs, and identified charged-kaon pairs in Au + Au, d + Au, and p + p collisions at root s(NN) = 200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These balance functions are presented in terms of relative pseudorapidity, Delta eta, relative rapidity, Delta y, relative azimuthal angle, Delta phi, and invariant relative momentum, q(inv). For charged-particle pairs, the width of the balance function in terms of Delta eta scales smoothly with the number of participating nucleons, while HIJING and UrQMD model calculations show no dependence on centrality or system size. For charged-particle and charged-pion pairs, the balance functions widths in terms of Delta eta and Delta y are narrower in central Au + Au collisions than in peripheral collisions. The width for central collisions is consistent with thermal blast-wave models where the balancing charges are highly correlated in coordinate space at breakup. This strong correlation might be explained by either delayed hadronization or limited diffusion during the reaction. Furthermore, the narrowing trend is consistent with the lower kinetic temperatures inherent to more central collisions. In contrast, the width of the balance function for charged-kaon pairs in terms of Delta y shows little centrality dependence, which may signal a different production mechanism for kaons. The widths of the balance functions for charged pions and kaons in terms of q(inv) narrow in central collisions compared to peripheral collisions, which may be driven by the change in the kinetic temperature.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We report a measurement of high-p(T) inclusive pi(0), eta, and direct photon production in p + p and d + Au collisions at root s(NN) = 200 GeV at midrapidity (0 < eta < 1). Photons from the decay pi(0) -> gamma gamma were detected in the barrel electromagnetic calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The eta -> gamma gamma decay was also observed and constituted the first eta measurement by STAR. The first direct photon cross-section measurement by STAR is also presented; the signal was extracted statistically by subtracting the pi(0), eta, and omega(782) decay background from the inclusive photon distribution observed in the calorimeter. The analysis is described in detail, and the results are found to be in good agreement with earlier measurements and with next-to-leading-order perturbative QCD calculations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Parity (P)-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the orbital momentum of the system created in noncentral collisions. To study this effect, we investigate a three-particle mixed-harmonics azimuthal correlator which is a P-even observable, but directly sensitive to the charge-separation effect. We report measurements of this observable using the STAR detector in Au + Au and Cu + Cu collisions at root s(NN) = 200 and 62 GeV. The results are presented as a function of collision centrality, particle separation in rapidity, and particle transverse momentum. A signal consistent with several of the theoretical expectations is detected in all four data sets. We compare our results to the predictions of existing event generators and discuss in detail possible contributions from other effects that are not related to P violation.