Characterization of DYRK2 (dual-specificity tyrosine-phosphorylation-regulated kinase 2) from Zebrafish (Dario rerio)

Proteins of the DYRK (dual-specificity tyrosine-phosphorylation-regulated kinase) family are characterized by the presence of a conserved kinase domain and N-terminal DH box. DYRK2 is involved in regulating key developmental and cellular processes, such as neurogenesis, cell proliferation, cytokinesis, and cellular differentiation. Herein, we report that the ortholog of DYRK2 found in zebrafish shares about 70% identity with that of human, mouse, and chick. RT-PCR showed that DYRK2 is expressed maternally and zygotically. In-situ hybridization results show that DYRK2 is expressed in somite cells that will develop into muscles. Our results provide preliminary evidence for investigating the in-vivo function of DYRK2 in zebrafish muscle development.

Multiplex CARS measurements in supersonic H-2/air combustion

H-2 and O-2 multiplex coherent anti-stokes Raman spectroscopy (CARS) employing a single dye laser has been explored to simultaneously determine the temperature and concentrations of H-2 and O-2 in a hydrogen-fueled supersonic combustor. Systematic calibrations were performed through a well-characterized H-2/air premixed flat-flame burner. In particular, temperature measurement was accomplished using the intensity ratio of the H-2 S(5) and S(6) rotational lines, whereas extraction of the H-2 and O-2 concentrations was obtained from the H-2 S(6) and O-2 Q-branch, respectively. Details of the calibration procedure and data reduction are discussed. Quantification of the supersonic mixing and combustion characteristics applying the present technique has been demonstrated to be feasible. The associated detection limits as well as possible improvements are also identified.

Single attosecond pulse generation in He+ by controlling the instant ionization rate using attosecond pulse trains combined with an intense laser pulse

High-order harmonics and single attosecond pulse generation by using an infrared laser pulse combined with attosecond pulse trains (APT) interacting with He+ have been investigated. We show that the ionization for different instant time intervals can be controlled by altering the time delay between the APT and the infrared pulse. Consequently, APT can be used as a tool to control the efficiency of high-order harmonics emitted at different times. By choosing appropriate APT and time delay, the driving pulse width for single attosecond pulse generation can be extended up to six optical cycles. (c) 2007 Optical Society of America.

利用数字全息干涉术观察RuO2：LiNbO3晶体中畴反转的区域特性

利用马赫-曾德尔干涉光路和V光学透镜系统，以部分畴反转的掺钌铌酸锂晶体（RuO2：LiNbO3）的透射光作为物光来记录全息图，并在数值再现过程对其进行频域滤波以实现物场波前信息的数值重建，检测出在一定电压作用下晶体内部折射率变化的二维分布．检测结果证实;晶体中发生畴反转的区域与发生电色效应的区域严格相符．数字全息干涉术非接触、无干扰、无破坏的优势在准实时监控、检测和分析铌酸锂晶体畴反转方面有很好的应用前景．

水母雪莲毛状根培养及黄酮类化合物生物合成的调控

水母雪莲(Saussurea medusa Maxim)为菊科凤毛菊属植物,是名贵中药材,其主要活性成分为黄酮类化合物。为解决雪莲资源匮乏，本文开展了利用水母雪莲毛状根培养生产黄酮类活性成分的研究。 在1/2MS液体培养基上研究了不同理化因子对水母雪莲毛状根生长和黄酮类化合物生物合成的影响。实验结果表明:氮源总浓度（包括NH4+和NO3-）为30 mmol/L;NH4+/NO3-比例为5:25;2 %蔗糖和3 %葡萄糖组合;0.5 mg/L GA3和0.5 mg/L IBA;pH 5.8;18 h/d的光照（光强为3500 Lux）;24℃;摇床转速为100 rpm的条件有利于毛状根生长及黄酮类化合物的生物合成。在此培养条件下，经过21 d的培养毛状根生长量达到12.8 g/L（DW），黄酮类化合物合成量为1922 mg/L，即黄酮类化合物含量占毛状根干重的15 %，约为野生水母雪莲植株干重黄酮类化合物含量的25倍。 用MJ和SA两种诱导子分别处理水母雪莲的毛状根，适宜条件下它们均能使毛状根中黄酮类化合物的产量得到提高。实验发现，在水母雪莲毛状根培养过程中，MJ抑制其生长，但提高了黄酮类化合物在毛状根中的百分含量;SA降低了黄酮类化合物在毛状根中的百分含量，但促进其生长。诱导子的作用效果与诱导子的浓度和添加时间有关。在延迟期后期添加浓度为0.02 mmol/L的MJ时黄酮类化合物产量达到 849 mg/L，比对照（633 mg/L）提高34.1 %;在指数生长期中期添加浓度为0.03 mmol/L的SA时，黄酮类化合物产量达到968 mg/L，比对照（633 mg/L）提高52.9 %。在指数生长期前期同时添加浓度为0.02 mmol/L的MJ 和0.03 mmol/L的SA，黄酮类化合物的产量为1125 mg/L，比对照（633 mg/L）提高77.7 %。 另外采取热水、碱提取，乙醇沉淀获得水母雪莲毛状根多糖。进一步用α-萘酚—浓硫酸法进行定性、定量分析，测得水母雪莲毛状根中水溶性多糖与碱溶性多糖的含量分别为2.453 %和3.391 % 。

Revealing the History of Sheep Domestication Using Retrovirus Integrations

The domestication of livestock represented a crucial step in human history. By using endogenous retroviruses as genetic markers, we found that sheep differentiated on the basis of their "retrotype" and morphological traits dispersed across Eurasia and Afr

黄鳝摄食活饵的初步研究

本文对不同体重的黄鳝摄食蚯蚓、蝌蚪、蛴螬的饵料系数、特定生长率、能量转化效率和最大摄食量等作了初步研究。结果表明 :在限食试验中 ,黄鳝摄食蚯蚓、蝌蚪、蛴螬的饵料系数分别为 3.2 83.89、7.0 99.0 7、3.393.4 2 ;特定生长率分别为 0 .33% 1.0 9%、1.0 9% 1.2 0 %、0 .6 5 % 0 .70 % ;能量转化效率分别为2 4 .9% 2 9.5 %、33.2 % 34.1%、2 8.8% 2 9.1%。饵料系数、特定生长率的大小主要决定于饵料性质 ,与体重(

青、草、鲢、鳙、鲤对氢离子浓度的生存适应性

<正> 一、引言氢离子浓度(pH值)的变化对于水生生物,特别是鱼类的生活常常被认为是直接或间接发生影响的因子之一。1920年,M.E.Jewell氏开始注意到水质的氢离子浓度变化对于两栖类蝌蚪代谢和再生作用的影响,他发现最适宜的氢离子浓度是中性或接近中性,同时发现再生率和再生总量和水中溶氧含量有密切关系。E.B.Power氏(1922)开始注意到氢离子浓度与鱼类呼吸生理之间的关系。此后,有许多学者研究了氢离子浓度对鱼类耗氧率的影响,以及氢离子浓度对鱼类从水中吸取溶氧机能的影响。其中

Phase uncertainty in calibrating microwave test fixtures

The problem of phase uncertainty arising in calibration of the test fixtures is investigated in this paper, It is shown that the problem exists no matter what kinds of calibration standards are used. It is also found that there is no need to determine the individual S-parameters of the test fixtures. In order to eliminate the problem of phase uncertainty, three different precise (known) reflection standards or one known reflection standard plus one known transmission standard should be used to calibrate symmetrical test fixtures. For the asymmetrical cases, three known standards, including at least one transmission standard, should be used. The thru-open-match (TOM) and thru-short-match (TSM) techniques are the simplest methods, and they have no bandwidth limitation. When the standards are imprecise (unknown), it is recommended to use any suitable technique, such as the thru-reflect-line, line-reflect-line, thru-short-delay, thru-open-delay,line-reflect-match, line-reflect-reflect-match, or multiline methods, to accurately determine the values of the required calibration terms and, in addition, to use the TOM or TSM method with the same imprecise standards to resolve the phase uncertainty.

钟控密钥流生成器及其密码性能

提出了一种新的钟控密钥流生成器,由3个移位寄存器组成:两个被钟控的线性反馈移位寄存器A和B,一个提供钟控信息的非线性反馈移位寄存器C。设A、B和C的长度分别为l1、l2和l3。移位寄存器A和B的钟控信息由从移位寄存器C选取的两个比特串提供,移位的次数分别是两个比特串的汉明重量。研究了该生成器的周期、线性复杂度和k错线性复杂度,分析了这种密钥流生成器的安全性。

金纳米线阵列制备及其光谱特性

利用电化学沉积方法在重离子径迹模板中制备出直径从45nm到200nm,长径比达700的金纳米线阵列,利用扫描电子显微镜(SEM)和X射线衍射(XRD)对所制备金纳米线的形貌及晶体结构进行分析,结果表明,在1.5V(无参比电极)沉积电压下所制备出的直径为200nm金纳米线沿[100]晶向具有较好择优取向.利用紫外-可见光谱(UV-Vis)对镶嵌在透明模板中平行排列的金纳米线阵列光学特性进行研究,发现金纳米线直径为45nm时,其紫外可见光谱在539nm处有强烈吸收峰,随着金纳米线直径增加,吸收峰红移,当金纳米线直径达到200nm时,其吸收峰峰位移至700nm.结合金纳米颗粒相关表面等离子体共振吸收效应对实验结果进行了讨论.