我国激光育成的农作物品种

本文整理撰写了七十年代初以来我国利用激光诱变育成的13种农作物突变品种名录38个,这些品种约占我国植物诱变品种总数的10％。叙述了诸如品种名称、育成单位、激光器种类及剂量、亲本材料、主要改良特性、审(鉴)定和推广应用情况以及相关的问题。展示了该研究领域的新动态。     

赤霉素产生菌的激光诱变育种研究

激光是一种新型的物理诱变剂,对微生物产生不同的诱变效应。本文报导用Ｈｅ－Ｎｅ激光对赤霉素产生菌进行照射１０－１５分钟产生较为满意的诱变效果;所得到的高产菌株的效价提高率可达１１０５以上。实验证明,掌握好激光器的种类功率大小和正确的诱变条件是诱变产生高产菌株的关键。     

激光诱变的生物学效应及其在动植物遗传育种上的应用

激光诱变是一种新型的育种技术,具有能量密度高,比较集中,单色性和方向性好,诱变当代即可出现遗传突变等特点。本文概述了激光诱变的一般原理和生物学效应,激光诱变后对植物形态,生理和遗传性状及动物早期胚肥发育的影响,旨在为深入研究激光诱变机制及其在动植物遗传育种上的应用提供参考。     

激光对家蚕诱变效应的探讨

激光应用于生物学的研究,国内外都取得了一定进展。Zkzolo用红宝石激光器照射雄性果蝇幼虫产生了突变。中山大学用CO_2激光器处理植物花药,引起大量染色体畸变。安徽农学院用钕玻璃激光器照射蚕卵,获得一雌一雄的突变体,进而育成新原种。华南农学     

激光在医学中的应用

本文叙述了几种激光器的优点及其在医学中的应用。它们在治疗过程中的应用方法有很多种,并且还存在有更多种类的激光器,这里选择叙述的是医生和专家常应用的。随着科技的发展,激光技术在医学中的应用将会越来越成熟,旧的激光器也将会被淘汰,越来越先进的激光器一定会问世。本文还将叙述激光的基本理论,以及不同手术中所采用的激光应用技术。     

激光生物学效应的研究

本文较系统地报道了CO_2激光,He-Ne激光的生物学作用,证明激光确能导致生物体内生理生化的变化,确能诱发染色体畸变和基因突变。作者认为激光作为育种上一种新的诱变因素是有根据的。     

Ar^＋,远红外激光,γ射线单一及复合处理水稻的诱变效果

用Ar~+、远红外两种激光和~(60)Co—r射线单一或复合处理两个籼稻品种的干种子,分析和比较了不同处理对水稻的当代生物学效应及处理二代的变异频率。结果表明,两种激光对当代的几个性状均表现为刺激效应,并有减轻,射线辐射损伤的作用,复合处理二代的变异频率和变异类型数明显高于相应的单一处理。说明复合处理是提高激光育种效果的有效方法。     

激光技术在医学域领中的最新应用

1960年美国科学家制造出世界第一台红宝石激光器,翌年立即用于医疗。激光技术在40年来取得了巨大成就。在医学领域内,激光技术已广泛应用于诊断、治疗及基础理论研究。由于激光器具有切割、凝固、气化、打孔、截骨等功能,目前已广泛应用于眼科、耳鼻喉科、皮肤科、普外科、神经外科和肿瘤科等。医用激光器作为手术治疗的器械,已充分显示了它无与伦比的优越性。近年在医学领域中的应用更是举世瞩目,下面介绍几种激光技术最新应用情况。     

远红外激光辐射引起水稻变异的研究——Ⅰ.发芽势和酯酶及过氧化物酶同工酶的变化

激光有明显的生物学效应。研究表明,激光会增加染色体的畸变频率,也会引起DNA的合成和胚胎发育异常。但多数的基础研究是以实验动物为对象,观察短波长激光的效应。有关激光对植物基因表达的效应则研究得不多。 近年来,亚毫米和短毫米波长激光谱线的研究和利用取得了较快的进展。光泵远红外激光器在波长40μm—3mm的远红外谱区都     

激光的生物学效应研究

本文通过分析多种激光（十五种激光器,波长从２６６ｎｍ—４４７．２×ｌ０３ｎｍ）对生物体（九十多种生物,如果把品种计算在内,则大约２００多种）的生物学效应研究发现：①不同波长激光都能对生物体产生作用;②激光对动物、植物、微生物均能产生生物学效应;③低剂量辐照对生物体主要是刺激作用,随着剂量增加则产生抑制、损伤,以及诱变和致死作用;④激光对６０Ｃｏ—γ射线的辐射损伤有一定的修复作用;⑤低功率激光对生物体的作用主要在于其电效应和电磁场效应（关于这个方面,将另文详细讨论）。     

A comparison of low-power helium-cadmium and argon ultraviolet lasers in commercial flow cytometers

The feasibility of installing a low power ultraviolet (UV) laser in a commercial flow cytometer was evaluated by testing an Ortho Cytofluorograf 50HH and a Coulter Epics V. Both instruments were equipped with two argon ion lasers, one emitting at 488 nm and the other in the UV region and were tested by measuring the DNA content of cells stained with Hoechst 33342 or DAPI. The coefficient of variation (CV) of the G0/G1 peak of the DNA histograms produced by each instrument did not deteriorate markedly when results obtained at 100-125 mW were compared to those obtained at 10 mW. These tests indicated that a helium-cadmium laser (He-Cd) which can produce 10 mW at 325 nm should work well as a UV laser in these instruments. An Ortho Cytofluorograf IIs was purchased with a 10 mW He-Cd laser installed in the forward position. Studies of DNA content have confirmed that this low power UV laser can produce CVs of 2.2% with DAPI stained fixed cells and 3.6% with Hoechst 33342 stained viable lymphocytes. Thus, the He-Cd laser should provide a reasonable alternative as a UV source for flow cytometers.     

Anchored cell analysis and sorting (ACAS) system]

Advanced biology and recent technology have provided sophisticated and objective method for analyzing biological characteristics on cells. Following that, many new instruments have developed. Diagnostic immunocytochemistry has become an accepted diagnostic tool in cell biology. In recent years, remarkable advances in technology provide a method for quantitative and objective analyses of cell characteristics. The newly developed computer assisted laser cytometer (ACAS 570) can be applied in clinical basis as well as in research laboratory. Fluorescent intensities of ancharage-dependent cells can be automatically analyzed and make it possible to separate a subpopulation of cells. This computer controlled system principally consists of argon ion laser, phase contrast microscope. Quantitative fluorescence measurements and computer graphic images can be obtained. The present paper demonstrates multiple applications of laser cytometer for evaluation of cell biology.     

Imaging aspects of cardiovascular disease at the cell and molecular level

Cell and molecular imaging has a long and distinguished history. Erythrocytes were visualized microscopically by van Leeuwenhoek in 1674, and microscope technology has evolved mightily since the first single-lens instruments, and now incorporates many types that do not use photons of light for image formation. The combination of these instruments with preparations stained with histochemical and immunohistochemical markers has revolutionized imaging by allowing the biochemical identification of components at subcellular resolution. The field of cardiovascular disease has benefited greatly from these advances for the characterization of disease etiologies. In this review, we will highlight and summarize the use of microscopy imaging systems, including light microscopy, electron microscopy, confocal scanning laser microscopy, laser scanning cytometry, laser microdissection, and atomic force microscopy in conjunction with a variety of histochemical techniques in studies aimed at understanding mechanisms underlying cardiovascular diseases at the cell and molecular level.     

Improved double immunofluorescence for confocal laser scanning microscopy.

Reliable double immunofluorescence labeling for confocal laser scanning microscopy requires good separation of the signals generated by the fluorochromes. We have successfully overcome the limitation of a single argon ion laser in achieving effective excitation of dyes with well-separated emission spectra by employing the novel sulfonated rhodamine fluorochromes designated Alexa 488 and Alexa 568. The more abundant antigen was visualized using the red-emitting Alexa 568, with amplification of the signal by a biotinylated bridging antibody and labeled streptavidin. This was combined with the green-emitting Alexa 488, which yielded brighter images than fluorescein but exhibited comparable photodegradation. With appropriate controls to ensure the absence of crosstalk between fluorescence channels, these dyes permitted unequivocal demonstration of co-localization. This combination of fluorochromes may also offer advantages for users of instruments equipped with alternative laser systems.     

飞秒激光与生物细胞作用机理及应用

飞秒激光是自1960年第一台激光器诞生以来,过去20年间由激光科学发展起来的最强有力的新工具之一。飞秒激光由于脉冲持续时间短、瞬时功率大、聚焦尺寸小的特点,使得其在超快、超强和超精细领域有着广阔的应用前景。其中最重要的一个方向是飞秒激光在生物细胞方面的应用。细胞是生命活动的基本单位。所有的病源微观上都体现在细胞中细胞器的工作,所以用飞秒激光作用在病体的细胞器上达到治疗的目的,是一个很有前景的领域。由于生物大分子和水几乎不吸收近红外光,故应用近红外飞秒激光对细胞进行手术,同时可在不损伤细胞活性的前提下对细胞进行实验。这种激光手术技术已被用于对细胞内结构进行切割和蚀除。介绍了该技术在细胞领域中的一些应用,如纳米手术、基因转染和染色体切割等;还介绍了飞秒激光技术与生物细胞中主要细胞器的祛除的原理、飞秒激光细胞操作与手术系统和实验中荧光成像、多光子成像显微镜等手段。     

Development and application of portable manual non-contact-type anthropometric instruments for measuring human anatomical longitudinal parameters

Several contact-type anthropometric instruments have been previously established for use in population surveys that contribute to the construction of anthropometric databases. Manual anthropometric measurements need to comply with or fulfill the following conditions: anatomical landmarks (term, location, and detecting method); measuring methods (item and subject's posture); five contact-type instruments (anthropometer, large sliding caliper, sliding caliper, spreading caliper, and tape measure); and well-trained examiners. Here, two manual non-contact-type portable anthropometric instruments were developed for measuring small regions such as the head and for larger regions such as the trunk of the human body, and for obtaining anatomical longitudinal parameters (length, height, breadth, and depth) based on the principle of projection by spot irradiation using laser markers. A new landmark-detecting method, based on the idea of visual landmarks, was proposed instead of the conventional palpation method (direct feeling with fingers), which was not appropriate for a non-contact measuring system. The accuracy of each instrument was tested using industrial tools, and performance was compared with contact-type instruments using a skeletal model (four measurements), a free posture manikin (eight measurements), and the healthy human body (five males and five females; nine measurements). Measurement errors and visual inspection to detect landmarks were discussed. The instruments show applicability to non-contact anthropometry.     

Comparison of three commercially available antibodies for flow cytometric monitoring of P-glycoprotein expression in tumor cells.

Cellular drug resistance to natural products is often due to the presence of an efflux pump which reduces intracellular drug content and chemosensitivity. A 170 kD cell surface resident P-glycoprotein is believed to act as the efflux pump. In the present report, we have compared three commercially available antibodies C-219, JSB-1, and mdr(Ab-1) for use in flow cytometric detection of P-glycoprotein positive cells. Our data show that C219 gives uniformly good results in a variety of murine and human tumor cell lines for detection of P-glycoprotein positive cells. We have also compared data of C219 stained cells analyzed in parallel on a flow cytometer equipped with a small laser (15 mW) and a large laser (5 watt) cell sorter. Data obtained on these two instruments are comparable. A staining protocol and data on dual staining of cells for DNA content by propidium iodide and P-glycoprotein expression after FITC labeling are also presented.     

A Temperature-Jump Optical Trap for Single-Molecule Manipulation

To our knowledge, we have developed a novel temperature-jump optical tweezers setup that changes the temperature locally and rapidly. It uses a heating laser with a wavelength that is highly absorbed by water so it can cover a broad range of temperatures. This instrument can record several force-distance curves for one individual molecule at various temperatures with good thermal and mechanical stability. Our design has features to reduce convection and baseline shifts, which have troubled previous heating-laser instruments. As proof of accuracy, we used the instrument to carry out DNA unzipping experiments in which we derived the average basepair free energy, entropy, and enthalpy of formation of the DNA duplex in a range of temperatures between 5°C and 50°C. We also used the instrument to characterize the temperature-dependent elasticity of single-stranded DNA (ssDNA), where we find a significant condensation plateau at low force and low temperature. Oddly, the persistence length of ssDNA measured at high force seems to increase with temperature, contrary to simple entropic models.     

Ultrafast Mid-IR Laser Scalpel: Protein Signals of the Fundamental Limits to Minimally Invasive Surgery

Lasers have in principle the capability to cut at the level of a single cell, the fundamental limit to minimally invasive procedures and restructuring biological tissues. To date, this limit has not been achieved due to collateral damage on the macroscale that arises from thermal and shock wave induced collateral damage of surrounding tissue. Here, we report on a novel concept using a specifically designed Picosecond IR Laser (PIRL) that selectively energizes water molecules in the tissue to drive ablation or cutting process faster than thermal exchange of energy and shock wave propagation, without plasma formation or ionizing radiation effects. The targeted laser process imparts the least amount of energy in the remaining tissue without any of the deleterious photochemical or photothermal effects that accompanies other laser wavelengths and pulse parameters. Full thickness incisional and excisional wounds were generated in CD1 mice using the Picosecond IR Laser, a conventional surgical laser (DELight Er:YAG) or mechanical surgical tools. Transmission and scanning electron microscopy showed that the PIRL laser produced minimal tissue ablation with less damage of surrounding tissues than wounds formed using the other modalities. The width of scars formed by wounds made by the PIRL laser were half that of the scars produced using either a conventional surgical laser or a scalpel. Aniline blue staining showed higher levels of collagen in the early stage of the wounds produced using the PIRL laser, suggesting that these wounds mature faster. There were more viable cells extracted from skin using the PIRL laser, suggesting less cellular damage. β-catenin and TGF-β signalling, which are activated during the proliferative phase of wound healing, and whose level of activation correlates with the size of wounds was lower in wounds generated by the PIRL system. Wounds created with the PIRL systsem also showed a lower rate of cell proliferation. Direct comparison of wound healing responses to a conventional surgical laser, and standard mechanical instruments shows far less damage and near absence of scar formation by using PIRL laser. This new laser source appears to have achieved the long held promise of lasers in minimally invasive surgery.