形成于细胞骨架微管中的量子计算

微管是细胞骨架中的重要组成部分和功能组件，其中充满了液体水。本文基于腔量子电动力学描述了微管中水的电偶极子与电磁辐射场的相互作用，并论述了基于量子力学原理的量子计算，进而探讨了微管实现量子计算的一种可能机理。     

量子药理学及其在我国的现状

本文试图使药物化学家和药理学家充分了解量子药理学在研究和开发新药中的作用。文中先简单说明量子药理学的兴起,尔后分四段叙述,即理论基础;扼要介绍常用的半经验方法;被计算的分子性质,特别是电荷分布和分子静电势;以及量子药理学在我国的现状。     

电离辐射对蛋白质分子作用的量子孤波分析

本文运用量子力学方法对蛋白质分子中孤波传播的非线性动力学特征进行了探讨。研究表明：电离辐射产生的自由基对蛋白质分子的伤害将会对携带能量、信息的孤立子波传播产生较为显著的影响。     

量子生物化学的某些进展

绪言随着电子光谱、顺磁共振、电离幅射等物理方法在生物学中的运用,量子力学的基本理论就成为研究生命物质微观结构的重要依据。量子生物化学就是一门研究生命物质微观结构的理论性学科。它是用量子力学的基本理论,通过数学运算来研究生物分子的电子结构、电磁性质、能量转移及化学反应等问题。在量子生物化学的发展过程中,     

遗传变异与修复机制的量子观点

根据一种使得量子可以完全克隆的机制——量子半保留克隆机制,并以量子相干态可以半保留克隆为基础,作了推广到研究生物DNA分子克隆上的尝试,提出了量子半保留克隆、量子涨落与量子压缩相干态可以作为分别研究生物的遗传、变异与修复机制的可行性基础.研究指出:细胞分裂事件或者细胞死亡事件服从泊松分布;DNA复制的过程中存在着自发的、不可避免的出错几率,相对大小为平均的基因数乘以4π之后的倒数(该公式的计算与实验结果十分吻合);存在修复机制,由此导致了生物体的特殊基因座不同的自发突变频率.     

TAKENO孤子的量子理论

研究蛋白质分子中能量远距离传输的机理,在Ｔａｋｅｎｏ提出的孤子理论的基础上,进上步考虑了氢键相互作用的非简谐性,并用量子力学对模型进行了处理,在连续近似下,得到的结果表明,能量可以通过以超声速运动的孤子来传输。     

量子点标记活细胞内GLUT4 蛋白的研究

目的:研究量子点标记活细胞内GLUT4蛋白的方法,用于长时程观察活细胞内GLUT4的转运过程。方法:使用在GLUT4蛋白膜外区构建了myc位点的L6-GLUT4myc细胞系,用胰岛素刺激L6细胞内的GLUT4myc转运到细胞膜上,通过抗体抗原反应先后将一抗9E10和偶联二抗IgG的量子点与特异性位点结合。结果:通过量子点标记固定细胞内GLUT4的实验,证明了标记方法的特异性和灵敏性。量子点能够标记细胞膜表面的GLUT4蛋白并伴随GLUT4的胞吞进入细胞。适当调整实验温度,用量子点标记细胞膜上的GLUT4并且在实验过程结束后将标记了量子点的GLUT4保持在细胞膜表面,能够观察活细胞内GLUT4蛋白内化和胞内循环的过程。结论:发展了量子点标记活细胞内GLUT4的方法,为进一步研究活细胞内GLUT4的转运过程打下了基础。     

量子点的生命科学中的应用

近年来,最子点（半导体纳米微晶体）的研究引起国内外研究者的广泛兴趣,其研究内容涉及物理、化学、材料等多材料,已成为一门新兴的交叉学科。虽然量子点在生物学中的应用才刚刚起步,但是已经取得了意义的进展,成为人们极为注意的一个热点。现就量子点的光学特性、制备方法以及在生物学中的研究进展和应用前景作一简要综述。     

一些海洋浮游植物量子产值的研究

现场实验以及用硅藻、金藻和绿藻所做的实验表明,在光饱和深度以下,随着深度的增加,浮游植物的量子产懂具有不变、增加和下降3种垂直变化趋势。偏离理论模式的后两种结果可能是由浮游植物的光强适应(Light-shade adaptation)等原因引起。还探讨了量子产值作为初级生产力模型和光利用效率模型中的参数的问题。     

量子点在癌症研究中的应用

半导体量子点具有长时间、多目标和灵敏度高等独特的光化学性质,这些特性使量子点成为细胞标记和生物应用中得到了广泛的应用。利用量子点目标定位癌细胞,对于寻找癌变部位具有指导的作用。近年来,利用量子点作为光动力学治疗癌症的能量供体也得到了一定的研究。简单地介绍了量子点独特的光学性质,并从量子点标记癌细胞、可视化癌细胞表面功能和在光动力学治疗癌症等方面综述了量子点在癌症诊断和治疗中的应用。     

激光对蛋白质分子作用产生的混沌态

在维一蛋白质分子链模型的基础上,引入了激光与蛋白质的相互作用项。用Ｍｅｉｎｉｋｏｖ方法讨论了激光对蛋白质分子上弧立子的作用发,现在弱激光的作用下蛋白质分子内的集体振荡可能进入混沌状态。结果表明弱激光能使蛋白质变性。     

量子点荧光技术标记肿瘤细胞中HSP的应用研究

目的探讨量子点荧光技术对人肾癌细胞株(ACHN)中不同HSP进行标记的可行性应用。方法利用量子点的荧光特性,免疫细胞化学方法检测体外培养的ACHN细胞中量子点特异性标记的HSP70、HSP90、HSPgp96的表达情况。结果共聚焦荧光显微镜下可见ACHN细胞中HSP70、HSP90、HSPgp96均有明显表达,呈现均匀分布的橙红色强荧光,且量子点在持续激发30分钟后无荧光淬灭发生。结论量子点荧光标记技术能够对不同HSP进行标记,且与传统的标记方法相比具有显著优点,可作为一种新型的检测技术应用于科研及临床标记检测中。     

The properties of bio-energy transport and influence of structure nonuniformity and temperature of systems on energy transport along polypeptide chains

A new theory of bio-energy transport along protein molecules in living systems, where the energy is released by hydrolysis of adenosine triphosphate (ATP), is proposed based on some physical and biological reasons. In the new theory, the Davydov's Hamiltonian and wave function of the systems are simultaneously modified and extended. A new interaction has been added into Davydov's Hamiltonian. The wave function of the excitation state of single particles for the excitons in the Davydov model is replaced by a new wave function of two-quanta quasicoherent state. In such a case, the bio-energy is transported by the new soliton, which differs from the Davydov's soliton. The soliton is formed through self- trapping of two excitons interacting amino acid residues. The exciton is generated by vibrations of amide-I (CO stretching) arising from the energy of hydrolysis of ATP. The properties of the new soliton are extensively studied by analytical method and its lifetime is calculated using the nonlinear quantum perturbation theory and a wide ranges of parameter values relevant to protein molecules. The lifetime of the new soliton at the biological temperature 300 K is enough large and belongs to the order of 10?1? s, or τ/τ?≥700, in which the soliton can transports over several hundreds amino acid residues. These studied results show clearly that the new soliton is thermally stable and has so larger lifetime that it can play an important role in biological processes. Thus the new model is a candidate of the bio-energy transport mechanism in protein molecules. In the meanwhile, the influences of structure nonuniformity in protein molecules and temperature of the systems on the states and properties of the soliton transport of bio-energy are numerically simulated and studied by the fourth-order Runge-Kutta method. The structure nonuniformity arises from the disorder distributions of masses of amino acid residues, side groups and impurities, which results also in the fluctuations of the spring constant of protein molecules, dipole-dipole interaction between the neighboring amides, exciton-phonon (vibration of amino acids)interaction, chain-chain interaction among the three channels and ground state energy of the systems. We investigated the behaviors and states of the new solitons in a single protein molecular chain and α-Helix protein molecules with three channels under influences of the structure nonuniformity. We prove first that the bio-energy is transported by a soliton, which can move without dispersion, retaining its shape, velocity and energy in a uniform and periodic protein molecule. When the structure nonuniformity exists, although the fluctuations of the spring constant, dipole-dipole interaction constant, exciton-phonon coupling constant and ground state energy and the nonuniformity distributions of masses of amino acid residues can change the states and properties of motion of new soliton, they are still quite stable and very robust against these structure nonuniformities, i.e., even there are a larger structure nonuniformity in the protein molecules, the new solitons cannot be still dispersed. If the effects of thermal perturbation of medium on the soliton in nonuniform proteins is considered again, the new soliton can transport also over a larger spacing of 400 amino acids and has a longer time period of 300 ps, it is still thermally stable up to 320 K under the influence of the above structure nonuniformities. However, the new soliton disperses in the case of a higher temperature of 325 K and in more large structure nonuniformity. Thus, we determine that the new soliton's lifetime and critical temperature are 300 ps and 320 K, respectively. These results are also consistent with analytical data obtained via quantum perturbed theory. For α-Helix protein molecules with three channels, the results obtained show that the structure nonuniformity and quantum fluctuation can change the states and features of the new solitons, for example, the amplitudes, energies and velocities of the new soliton are decreased, but the solitons have been not destroyed, they can still transport steadily along the molecular chains retaining energy and momentum. When the quantum fluctuations are larger, such as, structure disorders and quantum fluctuations of 0.67<α(K)<2, ΔW=±8%Wˉ, ΔJ=±1%Jˉ, Δ(χ?+χ?)=±3%(χˉ?+χˉ?) and ΔL=±1%Lˉ and Δ??=?|β(n)|, ?=0.1 meV, |β(n)|<0.5, the new soliton is still stable. Therefore, the new solitons are quite robust against these nonuniform effects. However, they will be dispersed or disrupted in cases of very large structure nonuniformity. When the influence of temperature on solitons is considered, we find that the new solitons can transport steadily over 333 amino acid residues in the case of a long time period of 120 ps, in which the soliton can retain its shape and energy to travel forward along protein molecules after their mutual collision at the biological temperature of 300 K. However, the soliton disperses in cases of higher temperatures 325 K under action of a larger structure disorder. Thus, its critical temperature is about 320 K. When the effects of structure nonuniformity and temperature are considered simultaneously, then the new soliton has still high thermal stability and can transport also along the protein molecular chains retaining its amplitude, energy and velocity, they will disperses in the larger fluctuations, for example, 0.67 Mˉ相似文献   

Design of europium(III) complexes with high quantum yield

This work describes a rational planning of a new light-conversion molecular device with high quantum yield. For this, we made modifications in the 3-amino-2-carboxypyridine and 3-amino-2-carboxypirazine acid ligands, generating eight different complexes. Theoretical methods have been used to calculate the quantum yield of each of the complexes. We first used the Sparkle model to calculate the ground-state geometries of the eight complexes. These data were used to perform theoretical predictions of the energy transitions using the INDO/S–CI method. After having obtained the geometry and the energy transitions, the energy transfer rates and quantum yield were calculated using a theoretical approach based on the application of the 4f–4f transition theory. The results show that the modifications in the 3-amino-2-carboxypyridine ligand had generated three complexes with high quantum yield (about 52.8, 51.6 and 52.8%). On the other hand, the modifications in the 3-amino-2-carboxypirazine led to only one complex with quantum yield larger than 50%, but it is the most efficient complex projected.     

丹参醌化合物结构特征与抗氧化活性

对双氢丹参醌I和丹参醌Ⅱ在油脂中的抗氧化作用及构效关系进行了量子化学研究。结果表明 ,抗氧化剂与油脂中碳中心自由基 (R· )复合成稳定自由基 (AH -R· ) ,可能是丹参醌抑制或阻止油脂氧化酸败的主要途径 ,双氢丹参醌I也可借助释放活泼H(本身转化成稳定自由基A· )有效清除R·。丹参醌分子本身的化学活性和对应的AH -R·与A·的稳定性对此类抗氧化作用有重要影响。AH -R·和A·中自旋集居分布 ,对比较抗氧化剂的相对活性可能是一个有价值的电子结构参数。     

Quantum entanglement in photoactive prebiotic systems

This paper contains the review of quantum entanglement investigations in living systems, and in the quantum mechanically modelled photoactive prebiotic kernel systems. We define our modelled self-assembled supramolecular photoactive centres, composed of one or more sensitizer molecules, precursors of fatty acids and a number of water molecules, as a photoactive prebiotic kernel systems. We propose that life first emerged in the form of such minimal photoactive prebiotic kernel systems and later in the process of evolution these photoactive prebiotic kernel systems would have produced fatty acids and covered themselves with fatty acid envelopes to become the minimal cells of the Fatty Acid World. Specifically, we model self-assembling of photoactive prebiotic systems with observed quantum entanglement phenomena. We address the idea that quantum entanglement was important in the first stages of origins of life and evolution of the biospheres because simultaneously excite two prebiotic kernels in the system by appearance of two additional quantum entangled excited states, leading to faster growth and self-replication of minimal living cells. The quantum mechanically modelled possibility of synthesizing artificial self-reproducing quantum entangled prebiotic kernel systems and minimal cells also impacts the possibility of the most probable path of emergence of protocells on the Earth or elsewhere. We also examine the quantum entangled logic gates discovered in the modelled systems composed of two prebiotic kernels. Such logic gates may have application in the destruction of cancer cells or becoming building blocks of new forms of artificial cells including magnetically active ones.     

Absolute quantum yield measurement of powder samples

Measurement of fluorescence quantum yield has become an important tool in the search for new solutions in the development, evaluation, quality control and research of illumination, AV equipment, organic EL material, films, filters and fluorescent probes for bio-industry. Quantum yield is calculated as the ratio of the number of photons absorbed, to the number of photons emitted by a material. The higher the quantum yield, the better the efficiency of the fluorescent material. For the measurements featured in this video, we will use the Hitachi F-7000 fluorescence spectrophotometer equipped with the Quantum Yield measuring accessory and Report Generator program. All the information provided applies to this system. Measurement of quantum yield in powder samples is performed following these steps: 1. Generation of instrument correction factors for the excitation and emission monochromators. This is an important requirement for the correct measurement of quantum yield. It has been performed in advance for the full measurement range of the instrument and will not be shown in this video due to time limitations. 2. Measurement of integrating sphere correction factors. The purpose of this step is to take into consideration reflectivity characteristics of the integrating sphere used for the measurements. 3. Reference and Sample measurement using direct excitation and indirect excitation. 4. Quantum Yield calculation using Direct and Indirect excitation. Direct excitation is when the sample is facing directly the excitation beam, which would be the normal measurement setup. However, because we use an integrating sphere, a portion of the emitted photons resulting from the sample fluorescence are reflected by the integrating sphere and will re-excite the sample, so we need to take into consideration indirect excitation. This is accomplished by measuring the sample placed in the port facing the emission monochromator, calculating indirect quantum yield and correcting the direct quantum yield calculation. 5. Corrected quantum yield calculation. 6. Chromaticity coordinates calculation using Report Generator program. The Hitachi F-7000 Quantum Yield Measurement System offer advantages for this application, as follows: High sensitivity (S/N ratio 800 or better RMS). Signal is the Raman band of water measured under the following conditions: Ex wavelength 350 nm, band pass Ex and Em 5 nm, response 2 sec), noise is measured at the maximum of the Raman peak. High sensitivity allows measurement of samples even with low quantum yield. Using this system we have measured quantum yields as low as 0.1 for a sample of salicylic acid and as high as 0.8 for a sample of magnesium tungstate. Highly accurate measurement with a dynamic range of 6 orders of magnitude allows for measurements of both sharp scattering peaks with high intensity, as well as broad fluorescence peaks of low intensity under the same conditions. High measuring throughput and reduced light exposure to the sample, due to a high scanning speed of up to 60,000 nm/minute and automatic shutter function. Measurement of quantum yield over a wide wavelength range from 240 to 800 nm. Accurate quantum yield measurements are the result of collecting instrument spectral response and integrating sphere correction factors before measuring the sample. Large selection of calculated parameters provided by dedicated and easy to use software. During this video we will measure sodium salicylate in powder form which is known to have a quantum yield value of 0.4 to 0.5.