Spectra of identified high-p(T) pi(+/-) and p((p)over-bar ) in Cu + Cu collisions at root s(NN)=200 GeV

We report new results on identified (anti) proton and charged pion spectra at large transverse momenta (3 < p(T) < 10 GeV/c) from Cu + Cu collisions at root s(NN) = 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-p(T) and the anomalous baryon to meson enhancement at intermediate transverse momenta. Both phenomena could be attributed to the creation of a new form of QCD matter. The results presented here bridge the system size gap between the available pp and Au + Au data, and allow for a detailed exploration of the onset of the novel features. Comparative analysis of all available 200 GeV data indicates that the system size is a major factor determining both the magnitude of the hadron spectra suppression at large transverse momenta and the relative baryon to meson enhancement.

Charged and strange hadron elliptic flow in Cu plus Cu collisions at root s(NN)=62.4 and 200 GeV

We present the results of an elliptic flow, v(2), analysis of Cu + Cu collisions recorded with the solenoidal tracker detector (STAR) at the BNL Relativistic Heavy Ion Collider at root s(NN) = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v(2)(p(T)), is reported for different collision centralities for charged hadrons h(+/-) and strangeness-ontaining hadrons K-S(0), Lambda, Xi, and phi in the midrapidity region vertical bar eta vertical bar < 1.0. Significant reduction in systematic uncertainty of the measurement due to nonflow effects has been achieved by correlating particles at midrapidity, vertical bar eta vertical bar < 1.0, with those at forward rapidity, 2.5 < vertical bar eta vertical bar < 4.0. We also present azimuthal correlations in p + p collisions at root s = 200 GeV to help in estimating nonflow effects. To study the system-size dependence of elliptic flow, we present a detailed comparison with previously published results from Au + Au collisions at root s(NN) = 200 GeV. We observe that v(2)(p(T)) of strange hadrons has similar scaling properties as were first observed in Au + Au collisions, that is, (i) at low transverse momenta, p(T) < 2 GeV/c, v(2) scales with transverse kinetic energy, m(T) - m, and (ii) at intermediate p(T), 2 < p(T) < 4 GeV/c, it scales with the number of constituent quarks, n(q.) We have found that ideal hydrodynamic calculations fail to reproduce the centrality dependence of v(2)(p(T)) for K-S(0) and Lambda. Eccentricity scaled v(2) values, v(2)/epsilon, are larger in more central collisions, suggesting stronger collective flow develops in more central collisions. The comparison with Au + Au collisions, which go further in density, shows that v(2)/epsilon depends on the system size, that is, the number of participants N-part. This indicates that the ideal hydrodynamic limit is not reached in Cu + Cu collisions, presumably because the assumption of thermalization is not attained.

Observation of pi(+)pi(-)pi(+)pi(-) photoproduction in ultraperipheral heavy-ion collisions at root s(NN)=200 GeV at the STAR detector

We present a measurement of pi(+)pi(-)pi(+)pi(-) photonuclear production in ultraperipheral Au-Au collisions at root s(NN) = 200 GeV from the STAR experiment. The pi(+)pi(-)pi(+)pi(-) final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The pi(+)pi(-)pi(+)pi(-) invariant mass spectrum of the coherent events exhibits a broad peak around 1540 +/- 40 MeV/c(2) with a width of 570 +/- 60 MeV/c(2), in agreement with the photoproduction data for the rho(0)(1700). We do not observe a corresponding peak in the pi(+)pi(-) final state and measure an upper limit for the ratio of the branching fractions of the rho(0)(1700) to pi(+)pi(-) and pi(+)pi(-)pi(+)pi(-) of 2.5% at 90% confidence level. The ratio of rho(0)(1700) and rho(0)(770) coherent production cross sections is measured to be 13.4 +/- 0.8(stat.) +/- 4.4(syst.)%.

Identified particle production, azimuthal anisotropy, and interferometry measurements in Au plus Au collisions at root s(NN)=9.2 GeV

We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au + Au collisions below the nominal injection energy at the BNL Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance solenoidal tracker at RHIC (STAR) detector at root s(NN) = 9.2 GeV from a test run of the collider in the year 2008. Midrapidity results on multiplicity density dN/dy in rapidity y, average transverse momentum < p(T)>, particle ratios, elliptic flow, and Hanbury-Brown-Twiss (HBT) radii are consistent with the corresponding results at similar root s(NN) from fixed-target experiments. Directed flow measurements are presented for both midrapidity and forward-rapidity regions. Furthermore the collision centrality dependence of identified particle dN/dy, < p(T)>, and particle ratios are discussed. These results also demonstrate that the capabilities of the STAR detector, although optimized for root s(NN) = 200 GeV, are suitable for the proposed QCD critical-point search and exploration of the QCD phase diagram at RHIC.

Observation of an Antimatter Hypernucleus

Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons-comprising an antiproton, an antineutron, and an antilambda hyperon-produced by colliding gold nuclei at high energy. Our analysis yields 70 +/- 17 antihypertritons (3/Lambda(H) over bar) and 157 +/- 30 hypertritons (H-3(Lambda)). The measured yields of H-3(Lambda) (3/Lambda(H) over bar) and He-3 ((3)(He) over bar) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and of nuclei containing strange quarks, have implications spanning nuclear and particle physics, astrophysics, and cosmology.

Longitudinal scaling property of the charge balance function in Au plus Au collisions at root s(NN)=200 GeV

We present measurements of the charge balance function, from the charged particles, for diverse pseudorapidity and transverse momentum ranges in Au + Au collisions at root S-NN = 200 GeV using the STAR detector at RHIC. We observe that the balance function is boost-invariant within the pseudorapidity coverage vertical bar-1.3, 1.3 vertical bar. The balance function properly scaled by the width of the observed pseudorapidity window does not depend on the position or size of the pseudorapidity window. This scaling property also holds for particles in different transverse momentum ranges. In addition, we find that the width of the balance function decreases monotonically with increasing transverse momentum for all centrality classes. (c) 2010 Elsevier B.V. All rights reserved.

Early effects of low dose C-12(6+) ion or X-ray irradiation on human peripheral blood lymphocytes

The aim of this study was to estimate the acute effects of low dose C-12(6+) ions or X-ray radiation on human immune function. The human peripheral blood lymphocytes (HPBL) of seven healthy donors were exposed to 0.05 Gy C-12(6+) ions or X-ray radiation and cell responses were measured at 24 h after exposure. The cytotoxic activities of HPBL were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT); the percentages of T and NK cells subsets were detected by flow cytometry; mRNA expression of interleukin (IL)-2, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma were examined by real time quantitative RT-PCR (qRT-PCR); and these cytokines protein levels in supematant of cultured cells were assayed by enzyme-linked immunosorbent assays (ELISA). The results showed that the cytotoxic activity of HPBL, mRNA expression of IL-2, IFN-gamma and TNF-alpha in HPBL and their protein levels in supernatant were significantly increased at 24 h after exposure to 0.05 Gy C-12(6+) ions radiation and the effects were stronger than observed for X-ray exposure. However, there was no significant change in the percentage of T and NK cells subsets of HPBL. These results suggested that 0.05 Gy high linear energy transfer (LET) C-12(6+) radiation was a more effective approach to host immune enhancement than that of low LET X-ray. We conclude that cytokines production might be used as sensitive indicators of acute response to LDL (C) 2009 COSPAR. Published by Elsevier Ltd. All rights reserved.

Center of mass energy and system-size dependence of photon production at forward rapidity at RHIC

We present the multiplicity and pseudorapidity distributions of photons produced in Au + Au and Cu + Cu collisions at root(NN)-N-s = 62.4 and 200 GeV. The photons are measured in the region -3.7 < eta < -2.3 using the photon Multiplicity detector in the STAR experiment at RHIC. The number of photons produced per average number of participating nucleon pairs increases with the beam energy and is independent of (lie collision centrality. For collisions with similar average numbers of participating nucleons the photon multiplicities are observed to be similar for An + Au and Cu + Cu collisions at a given beam energy. The ratios of the number of charged particles to photons in the measured pseudorapidity range are found to be 1.4 +/- 0.1 and 1.2 +/- 0.1 for root(NN)-N-s = 62.4 and 200 GeV, respectively. The energy dependence of this ratio could reflect varying contributions from baryons to charged particles, while mesons are the dominant contributors to photon production in the given kinematic region. The photon pseudorapidity distributions normalized by average number of participating nucleon pairs, when plotted as a function of eta-Y-beam, are found to follow a longitudinal scaling independent of centrality and colliding ion species at both beam energies. (C) 2009 Elsevier B.V. All rights reserved.

低剂量12C6+辐射对小鼠免疫系统损伤和抗氧化剂氮乙酰半胱氨酸的保护作用研究

实验目的：随着科技的发展，人类活动范围已经逐渐向外太空扩展，对于人类太空探索的最大威胁是太空中的各种粒子辐射。这些辐射包括太阳辐射（质子和电子）和银河辐射（质子占85%，氦离子占14%，重离子占1%）。众所周知，重离子与常规X和γ射线相比有较高的传能线密度（linear energy transfer, LET）和相对生物学效应（relative biological effectiveness, RBE），对机体组织和器官有较强的影响。放射治疗是肿瘤治疗的重要手段之一，由于肿瘤细胞的异质性，其对放、化疗的反应相差悬殊。本研究的目的是： 1评估辐射对健康机体产生的生物学风险； 2研究抗氧化剂氮乙酰半胱氨酸（NAC）对机体辐射损伤的保护作用 3不同肿瘤细胞辐射敏感性的差异。实验方法： 1 X射线或12C6+离子对小鼠进行不同剂量的全身辐射。NAC处理组小鼠在照射前1小时腹腔注射200mg/kg的NAC，对照组注射等体积的生理盐水。照射后不同时间点取样，利用流式细胞仪检测小鼠免疫细胞周期和凋亡情况，单细胞电泳检测淋巴细胞DNA损伤，MTT法（3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide）检测脾脏NK（natural killer，NK）细胞活性，微核法检测淋巴细胞染色体损伤情况，小鼠体内干扰素－γ（Interferon-γ，IFN-γ）由ELISA方法得到，小鼠血清中超氧化物岐化酶(Surperoxide dismutase SOD）由分光光度法测定，并观察胸腺和脾脏指数变化。 2 不同剂量X射线和12C6+离子辐射人肺腺癌细胞H1299和A549，用细胞克隆法检测照射后细胞存活曲线，流式细胞仪检测细胞周期和凋亡，Western-blot 检测A549 细胞P53蛋白表达。 结果： 1小鼠外周血淋巴细胞、胸腺细胞和脾脏淋巴细胞周期随着X射线照射剂量的增大而被阻滞在了G0/G1期，相同剂量的12C6+离子辐射时外周血淋巴细胞周期被阻滞在S期，分次连续X射线照射时，外周血淋巴细胞周期随着累积剂量的增加被阻滞在G2/M期；细胞凋亡比例随着照射剂量的增加而增加。小鼠血清中IFN-γ水平和脾脏中NK细胞活性在重离子照射剂量为0.05Gy时有显著增加，脾脏NK细胞活性随着照射剂量的增加而减弱。 2重离子照射后，小鼠淋巴细胞DNA和染色体的损伤随辐射剂量和照射后时间的延长而加剧。脾脏NK细胞活性在照射后各个时间点减弱，血清中IFN-γ水平和SOD酶活性随着重离子照射剂量的增加而降低。预防性给予NAC，12C6+离子辐射对淋巴细胞DNA和染色体所致损伤，胸腺细胞周期和凋亡，脾脏NK细胞活性，血清中IFN-γ的水平和SOD酶的活性的损伤与盐水组比较均有显著改善。 3 X射线照射对肺腺癌H1299细胞周期和凋亡率未产生明显影响，重离子照射后随着照射剂量的增加细胞周期被阻滞在G2/M期，细胞凋亡率也呈剂量依赖性；X射线和12C6+离子照射A549细胞后，细胞周期均被阻滞在G2/M期，凋亡率剂量依赖性增加。A549细胞P53蛋白的表达水平随着重离子照射剂量的增加而增加。结论： 1重离子辐射造成细胞DNA和染色体损伤随着照射剂量的增加和照射后时间的延长而增加，比X射线辐射损伤复杂和难以修复，产生这种现象的机理为辐射导致活性氧分子簇的产生，细胞因子和与细胞氧化反应有关的酶活性的变化，同时这种损伤对胸腺细胞周期、凋亡和胸腺、脾脏指数以及机体免疫系统都有影响；低剂量重离子辐射（0.05Gy）对小鼠机体的免疫力有刺激作用，机体免疫能力随着照射剂量增加和照射后时间的推移而减弱，不同的免疫器官对辐射的敏感性也不同； 2 200mg/kg 的NAC对辐射所致小鼠免疫系统损伤有很好的保护作用； 3 肺腺癌细胞H1299比同系A549具有较强的辐射敏感性，A549细胞凋亡的增加与P53蛋白表达水平升高有关

长期施肥对作物产量的贡献

以中国科学院沈阳生态试验站16年定位试验为平台,研究了8种施肥制度的增产效应与稳产性能。结果表明:不同施肥处理对作物产量有明显影响,作物平均产量NPK>NP>NK>N>PK>P>K>CK,不施N肥时(即P、K、PK等处理)作物产量低;肥料对作物产量的年际贡献率在N、NP、NK、NPK处理中总体呈上升趋势,而在P、K、PK处理中则表现出下降的趋势;从化肥N、P、K的增产效果上看,总趋势是N>P>K;作物年际间产量的变异系数随化肥的均衡施用呈下降的趋势;玉米在NPK处理时的稳产性能最好,大豆在PK处理的稳产性最好。

虎眼万年青多糖对小鼠免疫功能的调节作用

依据虎眼万年青组分中多糖对小鼠巨噬细胞吞噬功能的影响,筛选并优化出60%醇浓度中性多糖活性组分S3,进而研究其对体液免疫、细胞免疫及细胞因子变化的影响,并从细胞和分子水平探讨其作用的机理.方法:采用溶血素测定方法,测定S3对小鼠脾细胞溶血素抗体的诱导作用;采用3H-TdR渗入法,测定S3对ConA诱导小鼠脾淋巴细胞的增殖作用;采用3H-TdR后标记法,测定S3对NK细胞细胞毒活性的影响;以ELISA法测定S3对小鼠脾细胞IL-2产生的影响;利用流式细胞术,检测S3对T淋巴细胞亚群CD3、CD4、CD8、CD4/CD8阳性细胞百分率的影响;采用RT-PCR方法检测IL-2 mBNA的表达水平.结果:S3高、中剂量组能明显增强小鼠脾细胞溶血素抗体的形成(P<0.05);各剂量组均能明显增强ConA诱导的淋巴细胞增殖能力(P<0.001);各剂量组均能增强NK细胞的细胞毒活性并促进IL-2的产生(P<0.001,P<0.01);高、中剂量组CD8阳性细胞百分率明显降低(P<0.001),各剂量组均能显著地提高CD4/CD8阳性细胞百分率(P<0.001);高剂量组可明显促进脾细胞中细胞因子IL-2的mRNA表达,使表达量增加(P<0.05).结论:S3具有较强的增强机体多种免疫功能的作用,可利用开发为一种免疫增强药物.

人工合成生物降解可吸收材料细胞免疫学及致突变实验研究

目的：探讨骨科生物降解材料，聚己内酯（PCL）及其与聚乳酸（PLA）的共聚物的生物相容性。方法：采用细胞免疫学方法，观察材料对小鼠淋巴细胞转化功能及NK细胞活性的影响；采用小鼠体内微核试验观察四种不同生物降解材料对染色体的影响。结果：四种不同生物材料在不同时间对小鼠淋巴细胞转化功能及NK细胞活性的影响，与对照组无明显差异，微核实验致突变阴性。结论：本材料有良好的组织相容性，与国外同类产品对比，无明显差异。

热致液晶性序列嵌段共聚酯的多重热转变

本文利用DSC研究了热致液晶性序列嵌段共聚酯在不同升温速率时的多重熔融转变,和不同冷却速率对结晶与熔融过程的影响。发现T_(kn)和T_(ni)与热历史、升温速率及成形条件均无关,T_(kn)=425.86K,T_(nt)=480.60K;而T_(in)与T_(nk)随冷却速率增大而降低。

Immunomodulation and antitumor activity of kappa-carrageenan oligosaccharides

The modulation of carrageenan oligosaccharides from Kappaphycus striatum on the immune system in S 180-bearing mice was investigated. The mice inoculated with S180 cell suspension were treated p.o. with carrageenan oligosaccharides (50, 100 and 200 mu g/g) for 14 days. The effects of carrageenan oligosaccharides on transplantable tumors and macrophage phagocytosis, quantitative hemolysis of sheep red blood cells (QHS),. lymphocyte proliferation, the activity of natural killer cells (NK), production of interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) were studied. Carrageenan oligosaccharides could significantly inhibit the growth of transplantable sarcoma S180 and increase macrophage phagocytosis, the form of antibody secreted by spleen cells, spleen lymphocyte proliferation, NK cells activity, serumal IL-2 and TNF-alpha level in S 180-bearing mice. Considering all these results, it is suggested that carrageenan oligosaccharides exert their antitumor effect by promoting the immune system. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

高寒小嵩草草甸种子库和种子雨动态分析

对小嵩草草甸种子库的大小和物种组成及与种子雨、地上植被的关系进行了初步研究。结果表明，返青期和枯黄期小嵩草草甸种子库单位体积（1.0m×1.0m×0.1m）分别有种子nf=10550粒和nk＝13815粒，分别由22种和24种植物组成，分属9个科，其中，莎草科，豆科和龙胆科占优势，禾本科所占比例较小，每平方米种子雨nr=8436.4粒，由25种植物组成，分属10个科，莎草科和禾本科所占比例较大，种子库和种子雨在物种组成上有一定的相似性（r=0.7600,P<0.01），二者共有19个种，分别占种子库和种子雨物种总数的82.61和90.48。地上植被与种子库的相似性较小，地上植被中有43.24和51.35的植物分别在返青期和枯黄期种子库中出现，60％的植物出现于种子雨中。在物种分布和优势度上，地上植被与种子雨间一致性较高，但它们与种子库间有一定的分歧。从地上植被到返青期时的种子库，物种多样性降低了1.61，从而说明种子库不仅是地上植被补充更新的源泉之一，而且是维持植物物种多样性的一种机制。图3参13。