Responses of micropropagated peach cultivars to thermotherapy for the elimination of prunus necrotic ringspot virus

Peach (Prunus persica (L.) Batsch) shoot-cultures infected with prunus necrotic ringspot virus (PNRSV) were selected for evaluating the responses of in vitro grown shoots of cvs Hermosa and Summerset to thermotherapy. The survival of shoot-cultures during thermotherapy was improved by selection of the optimum concentration of 6-benzylamino purine in the medium and optimum age of shoots for treatment. Alternating high and low temperature thermotherapy regimes were more effective in decreasing virus titre than constant high temperatures. Of the regimes tested, the most effective inhibition of PNRSV combined with a high survival of shoots was obtained by applying 38°C for 16 h in light alternating with 28 ^CC for 8 h in darkness for 18 days for Hermosa and 22 days for Summerset. Following this treatment 90% of Hermosa and 40% of Summerset shoot-cultures were virus-free as determined by enzyme-linked immunosorbent assay. Relatively large (about 10 mm) apices excised from these shots regenerated into virus-free plants. The advantage of the in vitro system for thermotherapy is discussed.     

Interaction of free fatty acids with the erythrocyte membrane as affected by hyperthermia and ionizing radiation

The interference of hyperthermia and ionizing radiation, respectively, with the effects of capric (100), lauric (120), myristic (140), oleic (cis-181) and elaidic (trans-181) acids on the osmotic resistance of human erythrocytes was investigated. The results are summarized as follows: (A) not only at 37°, but also at 42° and 47°C lauric acid (120) represents the minimum chain length for the biphasic behaviour of protecting against hypotonic hemolysis at a certain lower concentration range and hemolysis promotion at subsequent higher concentrations; (B) with increasing temperatures the protecting as well as the hemolytic effects occur at lower concentrations of the fatty acids; (C) the increase of temperature promotes the extent of hemolysis and reduces the extent of protection against hypotonic hemolysis; (D) Gamma-irradiation of erythrocytes selectively affects the concentration of oleic acid at which maximum protection against hypotonic hemolysis occurs, without altering the minimum concentration for 100% hemolysis.     

生物基化学纤维产业发展现状与展望

生物基化学纤维具有生产过程环境友好、原料可再生以及产品可生物降解等优良特性,因此,大力发展生物基化学纤维对于替代化石资源、发展循环经济、建设资源节约型和环境友好型的社会具有十分重大的意义。本文介绍了我国生物基纤维产业的发展现状,分析了生物基纤维产业发展存在的问题,指出了生物基纤维材料科技创新趋势和目标,并给出了我国发展生物基纤维的建议。     

Myoglobin signal as an NMR tissue thermometer: implication for hyperthermia treatment of tumors

Measuring local tissue temperature is critical in stablishing a rational approach for hyperthermia treatment of tumors. We have found that the heme signals of myoglobin provide a unique basis for NMR thermometry in vivo. In particular the 5-methyl heme signal of MbCN exhibits a sharp, temperature-dependent resonance that is distinguishable in the tissue spectrum. Its calibrated chemical shift can then reflect the local tissue temperature in vivo.     

Comparison of SR-excited X-ray fluorescence analysis with neutron activation analysis for hair and fiber

Human scalp hair and some kinds of vegetable and animal fibers were analyzed by means of the SR excited X-ray fluorescence method (SRXFA) and the neutron activation method (NAA). Human hair samples collected from five males and five females were washed by the IAEA method prior to analysis. In the SRXFA analysis, samples were excited by monochromated X-rays. Fluorescence X-rays were measured by an Si(Li) detector. The elements detected in all hair samples were S, Ca, Cu, Fe, Zn, Br, and Sr. The elements K, Ti, Cr, Mn, Ni, Se, Hg, and Pb were also detected in several samples. After SRXFA analysis these same samples were analyzed by the NAA method. Elements such as Cu, Zn, and Br were detected by both methods, and their relative concentrations show a good agreement of variation between individuals. However, Pb was only detected by SRXFA, and Na, Au, and Sb were only detected by NAA. Therefore, these two methods are complementary to each other for trace element analysis.     

基于专家数据库的人体信息诊疗仪的研制

本文介绍了我们研制的一种基于电脑专家数据库的人体信息诊疗仪。融合了先进的激光技术、电子技术、计算机技术和人体信息诊疗学于一体。该仪器由两部分组成：（1）可自动诊断的电脑专家数据库;（2）半导体激光针灸部分。     

Concept of photonic hook scalpel generated by shaped fiber tip with asymmetric radiation

Structured light have made deep impacts on modern biotechnology and clinical practice, with numerous optical systems and lasers currently being used in medicine to treat disease. We demonstrate a new concept of fiber-based optical hook scalpel. The subwavelength photonic hook is obtained in the vicinity of a shaped fiber tip with asymmetric radiation. A 1550 nm continuous-wave source, commonly used for medical imaging, has been required. Photonic hook with a lateral feature size less than the half-wavelength is achieved using a hemispherical shaped fiber tip with metallic mask. This breakthrough is carried out in ambient air by using a 4-μm-diameter fiber with a shaped tip. A good correlation is observed between the computed intensity distribution of photonic hook and the tip sizes. Photonic hook generated with a shaped fiber tip, easier to manipulate, shows far-reaching benefits for potential applications such as ophthalmic laser surgery, super-resolution microscopy, photolithography and material processing.     

Effect of hyperthermia on TRAIL-induced apoptotic death in human colon cancer cells: development of a novel strategy for regional therapy

Approximately 25% of patients with colorectal cancer will develop metastatic disease exclusively or largely confined to the liver, and the vast majority of these cases are not amenable to surgical resection. These unresectable cases of liver metastatic disease can be treated with isolated hepatic perfusion (IHP), which involves a method of complete vascular isolation of the liver to allow treatment of liver tumors with toxic systemic doses of chemotherapeutic agents. To improve the efficacy of IHP, hyperthermia and biological agents have been applied along with the chemotherapeutic agents. In this study, we investigated whether hyperthermia in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) enhances mortality in human colorectal carcinoma CX-1 cells. Cells were treated with various concentrations of TRAIL (0-200 ng/ml) at various temperatures (40-46 degrees C) for 1 h and further incubated at 37 degrees C in the presence of TRAIL. We observed that hyperthermia at 42-43 degrees C effectively promoted TRAIL-induced apoptosis, as indicated by cell death, poly (ADP-ribose) polymerase (PARP) cleavage, and activation of caspase-8, -9, and -3. In contrast, hyperthermia at 45-46 degrees C suppressed TRAIL-induced apoptosis. We also observed that mild hyperthermia, but not acute hyperthermia, promoted cytochrome c release during treatment with TRAIL. Our data suggest that promotion of cytochrome c release during mild hyperthermia is responsible for the enhancement of TRAIL cytotoxicity.     

Development of acetylcholine sensor using carbon fiber (amperometric determination)

An enzyme sensor is developed using carbon fiber to measure acetylcholine concentration. The mechanism is based on the detection of H₂O₂ which is a product of the sequential enzyme reactions of acetylcholinesterase and choline oxidase. The fabrication of the electrode is described. The sensor is polarized at 1.2 V. Enzymes are co-immobilized in polyvinyl alcohol containing styryl pyrydinium (photo-crosslinkable polymer). A fast response time of 0.8 min is obtained. A linear correlation is observed between 0.2 and 1.0 mM. Other optimal operational conditions with respect to pH, temperature and stability are discussed. The use of carbon fiber containing co-immobilized enzymes could offer several model advantages especially in neuroscience research. In conclusion, the aims of the present work are centered on carbon fiber electrode fabrication, immobilization electrochemical measurements.     

An open-source algorithm for rapid unbiased determination of DNA fiber length

DNA fiber fluorography is widely employed to study the kinetics of DNA replication, but the usefulness of this approach has been limited by the lack of freely-available automated analysis tools. Quantification of DNA fibers usually relies on manual examination of immunofluorescence microscopy images, which is laborious and prone to inter- and intra-operator variability. To address this, we developed an unbiased, fully automated algorithm that quantifies length and color of DNA fibers from fluorescence microscopy images. Our fiber quantification method, termed FiberQ, is an open-source image processing tool based on edge detection and a novel segment splicing approach. Here, we describe the algorithm in detail, validate our results experimentally, and benchmark the analysis against manual assessments. Our implementation is offered free of charge to the scientific community under the General Public License.     

Development of optimized transfectoma cell lines for production of chimeric antibodies in hollow fiber cell culture systems

Methods for the selection of transfectoma cells that express large quantities of mouse-human chimeric antibodies have been develped. SP2/0 mouse myeloma cells were transfected with pSV2-gpt and pSV2-neo based immunoglobulin expression vectors. Double transfectants were selected using the xanthine-guanine phosphoribosyl transferase (gpt)and the neomycin (neo) selection marker genes. ELISA-based screening of transfectoma clones resulted in the isolation of IgG-producing transfectomas. Introduction of the kappa light-chain 3'-enhancer into the light-chain expression vector significantly increased immunoglobulin expression, but only when the enhancer was located at its physiological site, 9 kb downstream of the kappa constant region exon. With some of the transfectomas, final yields of up to 80 mg/L of chimeric IgG were obtained in conventional flask cultures using serum-free growth medium. A pilot-scale AcuSyst Maximizer hollow fiber cell culture system was used for the production of gram amounts of chimeric IgG. Results obtained with different transfectoma clones in conventional culture were not fully predictive for yields in the hollow fiber system. In contrast, differences in productivity between individual clones in the laboratory-scale Tecnomouse cell culture unit were comparable with those in the Maximizer system. Up to 200 mg of chimeric IgG were produced per day in one Maximizer bioreactor. (c) 1995 John Wiley & Sons, Inc.     

Microassay for malignant hyperthermia susceptibility: hypersensitive ligand-gating of the Ca channel in muscle sarcoplasmic reticulum causes increased amounts and rates of Ca-release

A crude preparation of heavy sarcoplasmic reticulum (HSR) was isolated using 1 gram of muscle obtained from swine susceptible to malignant hyperthermia (MH) and from control swine. The caffeine and ATP concentration-dependency of Ca-release was determined using suction filtration with radioisotopic ⁴⁵Ca as a tracer. Rates of release were determined using a rapid filtration system. Caffeine and ATP-induced Ca-release from MH-susceptible (MHS) HSR occurred at one-tenth the concentration of agonist that was required for control muscle HSR. No differences in rates and amounts of release were observed when agonist concentrations were used that caused maximum release for controls. However, at the threshold concentration of caffeine causing release for control HSR, the MHS HSR released 4-times as much Ca and at 3-times the rate of controls. These findings indicate that increased rates and amounts of Ca-release are due to the hypersensitivity of the Ca-release channel of HSR and that this abnormality can be detected using 1 gram of muscle.     

Proteomic analysis of testis biopsies in men treated with transient scrotal hyperthermia reveals the potential targets for contraceptive development

Mild testicular heating safely and reversibly suppresses spermatogenesis. In this study, we attempted to clarify the underlying molecular mechanism(s) involved in heat‐induced spermatogenesis suppression in human testis. We conducted global proteomic analyses of human testicular biopsies before, and at 2 and 9 wk after heat treatment. Thirty‐one and Twenty‐six known proteins were identified with significant differential expression at 2 and 9 wk after heat treatment, respectively. These were used to characterize the cellular and molecular events in the testes when seminiferous epithelia became damaged (2 wk) and recovered (9 wk). At 2 wk post‐treatment, the changed expression of a series of proteins could promote apoptosis or suppress proliferation and cell survival. At 9 wk post‐treatment, the changed expression of proteins mainly promoted cell proliferation, differentiation and survival, but resisted cell apoptosis. Among those heat‐regulated proteins, HNRNPH1 was selected for the further functional study. We found that HNRNPH1 was an anti‐apoptosis protein that could regulate the expression of other heat‐induced proteins. In conclusion, heat‐induced reversible suppression of spermatogenesis occurred by modulating the expression of proteins related to proliferation, differentiation, apoptosis and cell survival pathways. These differentially expressed proteins were found to be key molecular targets affecting spermatogenesis after heat treatment.     

Development of a radiometric metabolic viability testing method for human and porcine skin

A radiometric viability assay based upon the conversion of [¹⁴C]glucose into ¹⁴CO₂ by the viable cells on the dermal side of whole skin has been developed. The assay proved to be sensitive, reproducible, and practical, and was based upon the use of a microbiological growth detection system commonly used in many hospitals and laboratories. Relatively small samples of skin (0.25–1.00 g) were used in the test, and it was found that microbiological contamination did not interfere with the assay under normal conditions. The linear proportionality of the assay with both time and amount of skin assayed precluded the difficulties of nonlinear proportionality in other systems, allowing direct comparisons to be made between skin samples of different sizes and different incubation times. The assay could also detect ¹⁴CO₂ released from many radiolabeled substrates, including glucose, aspartate, glutamate, ornithine, orotic acid, and glycerol. Thus, the method could be used to test a number of cellular functions necessary for viability, including glycolysis, the functioning of the citric acid cycle and the pentose phosphate pathway, sugar and amino acid metabolism, pyrimidine biosynthesis, and cryopreservative agent metabolism. Since any of these tests could be performed in 4 hr, a viability assay based upon glycolysis alone, or in combination with any of the other tested substrates, could be carried out after allograft skin procurement before a decision needed to be made on skin cryopreservation.     

一种新型半导体激光治疗机研制

采用二合一光纤系统,高效率光纤耦合装置,AlGaInp半导体激光器, 方便适用的光纤定位装置以及稳定可靠的电源控制系统,研制了一种新型650nm半导体激光治疗仪,其光纤端输出达109mW。该仪器已在生物医学领域成功应用。     

Structural changes of the regulatory proteins bound to the thin filaments in skeletal muscle contraction by X-ray fiber diffraction

In order to clarify the structural changes related to the regulation mechanism in skeletal muscle contraction, the intensity changes of thin filament-based reflections were investigated by X-ray fiber diffraction. The time course and extent of intensity changes of the first to third order troponin (TN)-associated meridional reflections with a basic repeat of 38.4 nm were different for each of these reflections. The intensity of the first and second thin filament layer lines changed in a reciprocal manner both during initial activation and during the force generation process. The axial spacings of the TN-meridional reflections decreased by ∼0.1% upon activation relative to the relaxing state and increased by ∼0.24% in the force generation state, in line with that of the 2.7-nm reflection. Ca²⁺-binding to TN triggered the shortening and a change in the helical symmetry of the thin filaments. Modeling of the structural changes using the intensities of the thin filament-based reflections suggested that the conformation of the globular core domain of TN altered upon activation, undergoing additional conformational changes at the tension plateau. The tail domain of TN moved together with tropomyosin during contraction. The results indicate that the structural changes of regulatory proteins bound to the actin filaments occur in two steps, the first in response to the Ca²⁺-binding and the second induced by actomyosin interaction.     

麦秸秆/高密度聚乙烯（HDPE）复合材料中纤维分散性的描述模型

麦秸秆纤维作为一种重要生物质资源已被广泛应用于热塑性复合材料中。纤维在复合材料中的分散性是影响复合材料力学性能的重要因素之一,而目前对其定量化的描述和分析方法仍存在一定不足。本研究基于实验获得的纤维尺寸的统计分布规律,利用随机生成算法模拟纤维在复合材料中的分布;构建描述纤维分散性的指标:分散度,单个纤维数和接触纤维数;统计分析纤维含量、纤维大小对分散性指标影响。结果表明单个纤维数随纤维含量增加而增加,但其增量随纤维含量的增加而降低,降低规律符合三次函数。纤维接触数随纤维含量增加,增加规律符合二次函数,亦符合理论估计。纤维大小影响单个纤维数和接触纤维数的增加幅度,但不影响单个纤维数的百分比。分散度随纤维含量的增加呈线性下降规律。纤维分散性的定量化描述为进一步的复合材料性能分析和建模提供了量化指标。     

Characterization of broadband fiber optic line detectors for photoacoustic tomography

The frequency response of fiber optic line detectors is investigated in the presented paper. An analytical model based on oblique scattering of elastic waves is used to calculate the frequency dependent acousto‐optical transfer functions of bare glass optical and polymer optical fibers. From the transfer functions the transient response of fibers detectors to photoacoustically excited spherical sources is derived. Photoacoustic tomography is simulated by calculating the temporal response of arrays of fiber optic line detectors and subsequent image reconstruction. The results show that the choice of the fiber material is of significant importance and influences the quality of imaging. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

闭锁繁育乌骨鸡群体的RAPD指纹分析

随机抽样测定了一个长期闭锁繁育和一个开放繁育雪峰乌骨鸡群体的早期生长和成活率,并藉ＲＡＰＤ分析比较了２个乌骨鸡群体的遗传学特征,结果表明：闭锁繁育群体ＲＡＰＤ标记的平均共带系数和平均带纹频率显著高于开放群体．标记效应估计结果表明随机引物Ｓ１０２扩增的ｂ４（１８２０ｂｐ）和ｂ５（１９３０ｂｐ）片段和Ｓ１０５扩增的ｂ９（１８４９ｂｐ）和ｂ１０（４１０４ｂｐ）片段作为遗传标记对于体重（尤其是３５日龄和７０日龄体重）具有很高的负向相关效应,因此,该４个ＲＡＰＤ标记可以作为近交衰退候选指示标记加以深入研究,最终结论有待于在大样本、多群体、多世代资料中验证．