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1.
CO2激光辐照对酿酒酵母菌的诱变作用   总被引:8,自引:0,他引:8  
应用红外CO2激光对甘蔗糖蜜工业性生产用酿酒酵母菌Saccharomyces cerevisiae AS2.1189进行辐照处理,经酵母菌糖蜜酒精发酵试验,发现红外CO2激光对酿酒酵母菌具有诱变作用,并初步筛选到决乙醇含量有较大变化的辐照变异菌株;同时,通过对这些辐照变异菌株的乙醇脱氢酶同工酶的比较分析,进一步证实了红外CO2激光对酿酒酵母酶的诱变作用。从而为工业上利用红外CO2激光对酿酒酵母菌进  相似文献   

2.
C02激光辐照对酿酒酵母菌的诱变作用   总被引:1,自引:0,他引:1  
应用红外CO_2激光对甘蔗糖蜜工业性生产用酿酒酵母菌Saccharomyces cerevisiae AS2.1189进行辐照处理,经酵母菌糖蜜酒精发酵试验,发现红外CO_2激光对酿酒酵母菌具有诱变作用,并初步筛选到产乙醇含量有较大变化的辐照变异菌株;同时,通过对这些辐照变异菌株的乙醇脱氢酶同工酶的比较分析,进一步证实了红外CO_2、激光对酿酒酵母菌的诱变作用.从而为工业上利用红外CO_2激光对酿酒酵母菌进行诱变育种展现新的前景。  相似文献   

3.
低增益区红外Ti∶Al2O3飞秒激光器在西安通过鉴定由中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室侯洵学部委员,阮双琛研究员,王水才研究员等,完成了国家攀登计划“飞秒激光技术与超快过程研究”的子项目“低增益区红外Ti∶Al2O3飞秒激光...  相似文献   

4.
应用红外CO激光对甘蔗糖蜜工业性生产用酿酒酵母菌Saccharomyces cerevisiae AS2.1189进行辐照处理,经酵母菌糖蜜酒精发酵试验,发现红外CO激光对酿酒酵母菌具有诱变作用,并初步筛选到产乙醇含量有较大变化的辐照变异菌株;同时,通过对这些辐照变异菌株的乙醇脱氢酶同工酶的比较分析,进一步证实了红外CO、激光对酿酒酵母菌的诱变作用.从而为工业上利用红外CO激光对酿酒酵母菌进行诱变  相似文献   

5.
近年来红外荧光素的研发及相应的标记技术的进展在生物医学领域的研究中备受关注,通过与尖端仪器的结合在一系列生物样本的检测中得到广泛的应用. 然而,红外荧光标记技术在病毒感染生物学研究中的应用却少见报道.本文建立了Alexa Fluor 647(AF647)红外荧光素标记重组2型腺相关病毒(AAV2)的方法,并通过凝胶电泳的银染、红外荧光成像和透射电镜分析等手段,对标记病毒的结构和形态与未标记的病毒进行了细致的比较,同时进一步鉴定了其感染293T细胞后的转导活性.结果发现,AAV2在标记后的理化性质和感染活性均未发生改变. 应用狭缝印迹和激光共聚焦显微成像技术,分别对标记病毒的细胞摄取效率和在宿主细胞内的分布进行描述,为红外标记AAV2在研究中的应用提供了范例.AF647标记的 AAV2为腺相关病毒的感染动力学研究提供了新的手段,具有敏感度高、抗荧光漂白和低非特异干扰等优点,并且对直接有效地结合形态学分析和生化分子生物学检测,具有重要的应用价值.  相似文献   

6.
编者按     
<正>自1960年激光出现后的短短50多年以来,激光技术的飞速发展促进了紫外、可见和近红外和红外吸收光谱,荧光光谱,拉曼光谱等激光光谱技术的全面发展。激光光谱技术具有极高的光谱分辨率和探测灵敏度。近年来,随着各种非标记激光光谱技术以及特异性靶向功能标记技术的出现,激光光谱技术在人体组织的生化成分分析、疾病诊断、器官功能监测、药物疗效评估以及生物学研究等方面得到更广泛的应用。在庆祝《激光生物学报》创刊23周年,暨第12届全国激光生物学学术会议成功召开之际,我们编  相似文献   

7.
以薄皮库尔勒香梨、硬皮山竹为材料,研究水果自身性质及红外脉冲激光标刻参数对标刻效果及标刻后水果贮藏品质的影响,分析了不同果皮含水量、果皮硬度和标刻速度对激光标刻颜色、线宽和连续性的影响,并得到了在相对最优工艺参数下,贮藏期间水果果皮标刻区域的局部形貌、标记稳定性及腐烂情况.结果表明,果皮含水量、果皮硬度及标刻速度对薄皮...  相似文献   

8.
在激光果树育种中,激光的生物效应不仅取决于辐照时的激光参数,也取决于被辐照组织的部位、辐照季节等。本文对如何预选激光参数,并对激光诱变生物效应的机制均进行了探讨。紫外和可见激光的诱变机制主要是光化学反应;红外激光的诱变机制,在强激励方式下主要是多光子吸收,在弱激励时则热效应和非热的相干共振效应同时存在。  相似文献   

9.
本文回顾了激光心肌血管重建术的发展过程,对存在的问题进行了归纳总结和分析研究,对激光心肌血管重建术的治疗机理等问题进行了探讨。为激光心肌血管重建术的临床应用与研究提供一个参考。  相似文献   

10.
为了研究激光照射后角膜蛋白质化学组成的改变,探讨激光角膜损伤的发生机制,将日本大耳白兔随机分为正常对照组和激光损伤组,选取角膜上皮层和基质层作为研究对象,通过傅里叶变换红外光谱技术(Fou-rier transform infrared spectroscopy,FT-IR)对角膜组织酰胺I带中蛋白质二级结构各吸收峰进行定量分析,观察激光照射后蛋白质分子结构的改变情况。结果显示,激光照射后出现蛋白质二级结构吸收峰的位移和积分百分比的改变。激光照射可使角膜上皮层和基质层蛋白质构象发生改变,从而导致蛋白质结构稳定性下降和蛋白质生物功能的破坏。  相似文献   

11.
This paper discusses the development of biophysical methods for biochip analysis. A scheme and construction of a biochip analyzer based on wide-field digital fluorescence microscopy are described. The analyzer is designed to register images of biological microchips labeled with fluorescent dyes. The device developed is useful for high-sensitivity throughput recording of analyses with biochips after interaction of immobilized probes with fluorescently labeled sample molecules as well as it provides a higher rate of the analysis compared with laser scanning devices. With this analyzer, the scope where biological microchips can be applied becomes wider, development of new protocols of the analyses is possible and standard analyses run faster with the use of biochips, the expenses for performing routine analyses can be reduced.  相似文献   

12.
This paper discusses an issue on the development of biophysical methods for biochip analysis. A scheme and construction of a biochip analyzer based on wide-field digital fluorescence microscopy are described. The analyzer is designed to register images of biological microchips labeled with fluorescent dyes. The device developed is useful for high-sensitive throughput recording analyses by biochips after interaction of immobilized probes with fluorescently labeled sample molecules as well as it provides the higher rate of the analysis compared to laser scanning devices. With this analyzer a scope where biological microchips can be applied becomes wider, the development of new protocols of the analyses is possible and standard analyses run faster with the use of biochips, the expenses for the analysis performance can be reduced.  相似文献   

13.
The laser welding of biological tissues is a particular use of lasers in surgery. The technique has been proposed since the 1970s for surgical applications, such as repairing blood vessels, nerves, tendons, bronchial fistulae, skin and ocular tissues. In vascular surgery, two procedures have been tested and optimized in animal models, both ex vivo and in vivo, in order to design different approaches for blood vessels anastomoses and for the repair of vascular lesions: the laser-assisted vascular anastomosis (LAVA) and the laser-assisted vessel repair (LAVR). Sealing tissues by laser may overcome the problems related to the use of conventional closuring methods that are generally associated with various degrees of vascular wall damage that can ultimately predispose to vessel thrombosis and occlusion. In fact, the use of a laser welding technique provides several advantages such as simplification of the surgical procedure, reduction of the operative time, suppression of bleeding, and may guarantee an optimal healing process of vascular structures, very similar to restitutio ad integrum. Despite the numerous preclinical studies performed by several research groups, the clinical applications of laser-assisted anastomosis or vessel repair are still far off. Substantial breakthrough in the laser welding of biological tissues may come from the advent of nanotechnologies. Herein we describe the present status and the future perspectives in laser welding of vascular structures.  相似文献   

14.
The present paper introduces an innovative contact-free optical viscosity measurement technique, laser-induced capillary wave (LiCW) using pulsed YAG laser as a heating source, to measure whole-blood viscosity with only a microliter-order sample volume and measurement time on the millisecond order. In this method, interfering pulsed laser beams heat a whole-blood sample and generate a capillary wave, the amplitude of which is less than 10 nm with wavelength of 80–100 μm in the present experiment, caused by a spatially sinusoidal temperature distribution. The damped oscillation of the capillary wave, which is detected by a diffracted probing laser beam at the heated area, provides information regarding the viscosity and surface tension of the whole blood. To demonstrate the validity of the present laser-induced capillary wave viscometer, the viscosity of human whole blood taken from two healthy donors having different hematocrit values was measured using 90 μl sample volumes at 37°C. To consider the feasibility of the present technique for blood rheological studies, we discuss the characteristics of LiCW regarding the non-Newtonian behavior of blood, the velocity boundary layer, the existence of a free surface, and the temperature increase of the blood, and also demonstrate the capability of the method to sense the temporal evolution of blood viscosity with sampling frequency of 0.25 Hz.  相似文献   

15.
A new use is described for the CO2 laser--that of deepithelialization. Deepithelialization is a technique used in a myriad of plastic surgical procedures. This paper introduces the use of the laser for deepithelialization and illustrates its advantages in 44 consecutive patients undergoing reduction mammaplasty. Advantages are the precise removal of the upper dermis and epidermis--a true deepithelialization--with preservation of the lower dermis and pilosebaceous units. Associated decreased blood loss and more rapid operating time without an increase in complications makes this an attractive adjunctive technique with a wide variety of applications. No adverse effects or contraindications to the use of the CO2 laser for deepithelializing have been found.  相似文献   

16.
目的:探讨低强度氦氖激光对临床中风等缺血性疾病患者红细胞变形能力影响情况。方法:临床采集不同缺血性疾病患者新鲜血样,检测各组红细胞变形能力情况。对中风患者血样进一步分组,给予不同剂量的氦氖激光处理,讨论临床低强度氦氖激光量效关系,探讨具有临床疗效的有效剂量情况。结果:各疾病病组红细胞变形能力较正常对照组红细胞变形能力为低;缺血疾病组样品经低强度氦氖激光照射后,其红细胞变形能力较未经激光照射组有显著不同。结论:显示体外人红细胞变形能力因患者疾病情况、红细胞状态、低强度氦氖激光临床治疗输出功率等因素有不同。  相似文献   

17.
In this paper, we examine the performance of a pencil-and-paper screening questionnaire on depressive symptoms (the Center for Epidemiologic Studies Depression Scale, or CES-D) in a sample of 120 adult American Indians belonging to a single Northwest Coast tribe. Results of factor analyses suggest that somatic complaints and emotional distress are not well differentiated from each other in this population. CES-D scores (which have shown good sensitivity and specifity for depressive disorders in this sample) also show weak and apparently nonsignificant trends to be elevated in the presence of other psychiatric diagnoses (including alcoholism) or general impairment. However, because of the use of a convenience sample (rather than a probability sample), analyses of associations between study factors - including comorbidity - are liable to produce spurious results due to selection bias (including Berkson bias). On this basis, we suggest that the use of probability samples should assume a high priority in cross-cultural studies. The study of the entire population of interest is another solution to the sampling problem, particularly in small communities.  相似文献   

18.
Laser microdissection is an invaluable tool in medical research that facilitates collecting specific cell populations for molecular analysis. Diversity of research targets (e.g., cancerous and precancerous lesions in clinical and animal research, cell pellets, rodent embryos, etc.) and varied scientific objectives, however, present challenges toward establishing standard laser microdissection protocols. Sample preparation is crucial for quality RNA, DNA and protein retrieval, where it often determines the feasibility of a laser microdissection project. The majority of microdissection studies in clinical and animal model research are conducted on frozen tissues containing native nucleic acids, unmodified by fixation. However, the variable morphological quality of frozen sections from tissues containing fat, collagen or delicate cell structures can limit or prevent successful harvest of the desired cell population via laser dissection. The CryoJane Tape-Transfer System®, a commercial device that improves cryosectioning outcomes on glass slides has been reported superior for slide preparation and isolation of high quality osteocyte RNA (frozen bone) during laser dissection. Considering the reported advantages of CryoJane for laser dissection on glass slides, we asked whether the system could also work with the plastic membrane slides used by UV laser based microdissection instruments, as these are better suited for collection of larger target areas. In an attempt to optimize laser microdissection slide preparation for tissues of different RNA stability and cryosectioning difficulty, we evaluated the CryoJane system for use with both glass (laser capture microdissection) and membrane (laser cutting microdissection) slides. We have established a sample preparation protocol for glass and membrane slides including manual coating of membrane slides with CryoJane solutions, cryosectioning, slide staining and dissection procedure, lysis and RNA extraction that facilitated efficient dissection and high quality RNA retrieval from CryoJane preparations. CryoJane technology therefore has the potential to facilitate standardization of laser microdissection slide preparation from frozen tissues.  相似文献   

19.
The purpose of this research was to explore the possibility of employing PAT for particle sizing during spray drying with the use of an in-line and at-line laser diffraction system. Microspheres were made using maltodextrin and modified starch as wall material and size results obtained using PAT compared with those determined with off-line laser diffraction and light microscopy. Median particle size results were highest for in-line laser diffraction, followed by at-line and off-line laser diffraction and finally light microscopy. This was due to the presence of agglomerates which were measured as discrete microspheres in the in-line set-up. At-line and off-line laser diffraction gave results more closely correlated with individual microsphere sizes due to agglomerate breakdown during the measurement process. Light microscopy allowed direct observation of the particle morphology, however, its use for particle sizing was tedious and sample size was much smaller compared to laser diffraction. Although PAT was found to be an efficient and convenient tool, careful data interpretation was needed taking into account the cohesiveness of the material measured. The at-line set-up appeared to be more suitable in this particular application.  相似文献   

20.
Crowley TA  Hayes MA 《Proteomics》2005,5(14):3798-3804
Off-line coupling of capillary IEF (CIEF) with matrix-assisted laser desorption/ionization mass spectrometry was utilized for the analysis of human blood serum. Serum proteins were initially separated by CIEF, and fractions of the isoelectric separation were eluted sequentially to a MALDI-TOF MS sample target. During pressure elution of the CIEF sample, voltage was maintained across the capillary system utilizing a sheath flow arrangement to minimize band broadening induced by the laminar flow field. Both pI and mass information were obtained from the complex biological sample, similar to traditional 2-DE techniques, and the platform was faster (hours versus days), more automatable, and simpler than 2-DE. The volume of raw sample present in the actual analysis was approximately 100 nL, making this technique well suited for very rare specimens. Additionally, the speed and simplicity of the technology make it an attractive technique for performing initial comparative analyses of complex samples.  相似文献   

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