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Can DyeCycling break the photobleaching limit in single-molecule FRET?

1999年

作者： Bernard J. Hamrock Bo O. Jacobson Steven R. schmid.

来源：畅想之星图书光盘版（南... 评论

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Nano Research 2022年第11期15卷 9818-9830页

作者： Benjamin Vermeer Sonja schmid NanoDynamicsLab Laboratory of BiophysicsWageningen UniversityStippeneng 46708WE WageningenThe Netherlands

Biomolecular systems,such as proteins,crucially rely on dynamic processes at the *** biomolecular nanodynamics is therefore key to obtaining a mechanistic understanding of the energies and molecular driving forces that controlbiomolecular ***-molecule fluorescence resonance energy transfer(smFRET)is a powerful technique to observe inreal-time how a single biomolecule proceeds through its functional cycle involving a sequence of distinct structural ***,this technique is fundamentally limited by irreversible photobleaching,causing the untimely end of the experiment andthus,a narrow temporal bandwidth of≤3 orders of ***,we introduce“DyeCycling”,a measurement scheme withwhich we aim to break the photobleaching limit in *** introduce the concept of spontaneous dye replacement bysimulations,and as an experimental proof-of-concept,we demonstrate the intermittent observation of a single biomolecule forone hour with a time resolution of ***,DyeCycling can provide>100-fold more information per singlemolecule than conventional *** discuss the experimental implementation of DyeCycling,its current and fundamentallimitations,and specific biological use *** its general simplicity and versatility,DyeCycling has the potential torevolutionize the field of time-resolved smFRET,where it may serve to unravel a wealth of biomolecular dynamics by bridgingfrom milliseconds to the hour range.

关键词： biomolecular dynamics single-molecule fluorescence resonance energy transfer(smFRET) photobleaching conformational changes single-molecule kinetics

Prospect of gastroenterology and hepatology in the next century

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World Journal of Gastroenterology 1999年第3期5卷 185-190页

作者： Rudi schmid University of California 美国

The task of predicting what Gastroenterology and Hepatology may look like in the coming century is a great personal challenge and at the same time an awe-inspiring assignment. Not only have these two medical specialties become very large and diversified but there are so many new discoveries and ideas that it is a capricious undertaking to attempt fore-telling which of them may become part of the next century′s medical practice. I therefore will take the personal privilege of being highly selective, choosing only topics for discussion which I believe have a distinct potential of generating novel scientific concepts, fresh approaches or new therapeutic modalities.

关键词： Prospect of gastroenterology and hepatology in the next century

一种崭新的语言动态模型——《语言系统的动态性使用、规约化和固化》评介

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当代语言学 2023年第4期25卷 625-631页

作者： Hans-Jorg schmid 田良斌刘国兵不详河南师范大学马克思主义学院、外国语学院河南师范大学外国语学院

1. 引言Peirce(1936)从辩证唯物论本体论综合的符号哲学思想出发, 认为“语言系统”是人脑控制的社会交际的信息符号系统, 承载人们通过主观实践所获取的全部知识。相比之下, Saussure(1959)语言观中的“符号”, 显然是一种狭义的说法,... 详细信息

1. 引言Peirce(1936)从辩证唯物论本体论综合的符号哲学思想出发, 认为“语言系统”是人脑控制的社会交际的信息符号系统, 承载人们通过主观实践所获取的全部知识。相比之下, Saussure(1959)语言观中的“符号”, 显然是一种狭义的说法, 是通过声音要素和概念要素相互联系的结果, 即Saussure认为语言实际上是一种符号系统。语言系统呈现为何种样貌, 又从何而来, 一直是学者们讨论的焦点议题(P.1)。

关键词：信息符号符号系统概念要素焦点议题辩证唯物论符号哲学动态模型社会交际

Transient thermal analysis as measurement method for IC package structural integrity

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Chinese Physics B 2015年第6期24卷 47-64页

作者： Alexander Han Maximilian schmid E Liu Gordon Elger Technische Hochschule Ingolstadt

Practices of IC package reliability testing are reviewed briefly, and the application of transient thermal analysis is examined in great depth. For the design of light sources based on light emitting diode （LED） efficient and accurate reliability testing is required to realize the potential lifetimes of 105 h. Transient thermal analysis is a standard method to determine the transient thermal impedance of semiconductor devices, e.g. power electronics and LEDs. The temperature of the semiconductor junctions is assessed by time-resolved measurement of their forward voltage （Vf）. The thermal path in the IC package is resolved by the transient technique in the time domain. This enables analyzing the structural integrity of the semiconductor package. However, to evaluate thermal resistance, one must also measure the dissipated energy of the device （i.e., the thermal load） and the k-factor. This is time consuming, and measurement errors reduce the accuracy. To overcome these limitations, an innovative approach, the relative thermal resistance method, was developed to reduce the measurement effort, increase accuracy and enable automatic data evaluation. This new way of evaluating data simplifies the thermal transient analysis by eliminating measurement of the k-factor and thermal load, i.e. measurement of the lumen flux for LEDs, by normalizing the transient Vf data. This is especially advantageous for reliability testing where changes in the thermal path, like cracks and delaminations, can be determined without measuring the k-factor and thermal load. Different failure modes can be separated in the time domain. The sensitivity of the method is demonstrated by its application to high- power white InGaN LEDs. For detailed analysis and identification of the failure mode of the LED packages, the transient signals are simulated by time-resolved finite element （FE） simulations. Using the new approach, the transient thermal analysis is enhanced to a powerful tool for reliability

关键词： transient thermal analysis thermal resistance reliability light emitting diode

Diagnostic approaches for cholangiocarcinoma

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World Journal of Gastroenterology 2008年第26期14卷 4131-4136页

作者： Andreas Weber Roland M schmid Christian Prinz Department of Internal Medicine Ⅱ Technical University of MunichMunich 81675Germany

Cholangiocarcinomas arise from the epithelial cells of the bile ducts and are associated with poor prognosis. Despite new diagnostic approaches, the definite diagnosis of this malignancy continues to be challenging. Cholangiocarcinomas often grow longitudinally along the bile duct rather than in a radial direction. Thus, large tumor masses are frequently absent and imaging techniques, including ultrasound, CT, and MRI have only limited sensitivity. Tissue collection during endoscopic (ERCP) and/or percutaneous transhepatic (PTC) procedures are usually used to confirm a definitive diagnosis of cholangiocarcinoma. However, forceps biopsy and brush cytology provide positive results for malignancy in about only 50% of patients. Percutaneous and peroral cholangioscopy using fiber-optic techniques were therefore developed for direct visualization of the biliary tree, yielding additional information about endoscopic appearance and tumor extension, as well as a guided biopsy acquistion. Finally, endoscopic ultrasonography (EUS) complements endoscopic and percutaneous approaches and may provide a tissue diagnosis of tumors in the biliary region through fine-needle aspiration. In the future, new techniques allowing for early detection, including molecular markers, should be developed to improve the diagnostic sensitivity in this increasing tumor entity.

关键词： Diagnosis Brush cytology Forceps biopsy Cholangiocarcinoma

Male-mediated developmental toxicity

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Asian Journal of Andrology 2014年第1期16卷 81-88页

作者： Diana Andersonl Thomas E schmid Adolf Baumgartner Division of Medical Sciences School of Life Sciences University of Bradford Bradford West Yorkshire BD UK Department of Radiation Oncology Klinikum rechts der Isar Technische Universit~t MOnchen Munich Germany.

Male-mediated developmental toxicity has been of concern for many years. The public became aware of male-mediated developmental toxicity in the early 1990s when it was reported that men working at Sellafield might be causing leukemia in their children. Human and animal studies have contributed to our current understanding of male-mediated effects. Animal studies in the 1980s and 1990s suggested that genetic damage after radiation and chemical exposure might be transmitted to offspring. With the increasing understanding that there is histone retention and modification, protamine incorporation into the chromatin and DNA methylation in mature sperm and that spermatozoal RNA transcripts can play important roles in the epigenetic state of sperm, heritable studies began to be viewed differently. Recent reports using molecular approaches have demonstrated that DNA damage can be transmitted to babies from smoking fathers, and expanded simple tandem repeats minisatellite mutations were found in the germline of fathers who were exposed to radiation from the Chernobyl nuclear power plant disaster. In epidemiological studies, it is possible to clarify whether damage is transmitted to the sons after exposure of the fathers. Paternally transmitted damage to the offspring is now recognized as a complex issue with genetic as well as epigenetic components.

关键词： genetic and epigenetic effects human exposure to chemicals and radiation male-mediated animal studies paternalexposure to chemicals and radiation

Distribution of Debris Flows in Glacier National Park,Montana,U.S.A.

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Journal of Mountain Science 2008年第4期5卷 318-326页

作者： WILKERSON Forrest D. schmid Ginger L. Department of Geography 7 Armstrong HallMinnesota State UniversityMankatoMN 56001USA

The spectacular scenery of Glacier National Park is the result of glacial erosion as well as post-glacial mass wasting processes. Debris flow magnitude and frequency have been established through extensive fieldwork across seven separate drainage basins in the eastern portion of the park. This paper summarizes the investigation of the hypotheses that debris flow distribution in the Glacier National Park, east of the Continental Divide is （a） not random; and Co） concentrated adjacent to the Continental Divide. The location of 2317 debris flows were identified and mapped from sixty-three 1-m resolution Digital Orthophoto Quarter Quadrangles and their spatial distribution was then analyzed using ArcView Spatial Analyst GIS software. The GIS analysis showed that the debris flows are not randomly distributed nor are they concentrated directly adjacent to the Divide. While the Continental Divide provides orographic enhancement of precipitation directly adjacent to the Divide, the debris flows are not concentrated there due to a lack of available weathered regolith. The most recent Little Ice Age glaciation removed the debris directly adjacent to the Divide, and without an adequate debris supply, these steep slopes experience few debris flows. Both abundant water and an adequate debris supply are necessary to initiate slope failure, resulting in a clustering of debris flows at the break in slope where valley walls contact talus slopes. A variety of summer storm and antecedent moisture conditions initiate slope failures in the Glacier National Park, with no distinct meteorological threshold. With over two million visitorsevery year, and millions of dollars of park infrastructure at risk, identifying the hazard of debris flows is essential to future park management plans.

关键词： Debris flows remote sensing GIS GlacierNational Park USA

Complementarity among species in horizontal versus vertical rooting space

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Journal of Plant Ecology 2008年第1期1卷 33-41页

作者： Stefanie von Felten Bernhard schmid Institute of Environmental Sciences University of Zurich8057 ZurichSwitzerland Institute of Plant Sciences ETH Zurich8092 ZurichSwitzerland

Aims Many experiments have shown a positive effect of species richness on productivity in grassland plant ***,it is poorly understood how environmental conditions affect this *** aimed to test whether deep soil and limiting nutrient conditions increase the complementarity effect(CE)of species richness due to enhanced potential for resource *** We grew monocultures and mixtures of four common grassland species in pots on shallow and deep soil,factorially combined with two nutrient *** volume was kept constant to avoid confounding soil depth and *** an additive partitioning method,we separated biodiversity effects on plant productivity into components due to species complementarity and *** findings Net biodiversity and complementarity effects were consistently higher in shallow pots,which was unexpected,and at the low nutrient *** two results suggest that although belowground partitioning of resources was important,especially under low nutrient conditions,it was not due to differences in rooting *** conclude that in our experiment(i)horizontal root segregation might have been more important than the partitioning of rooting depths and(ii)that the positive effects of deep soil found in other studies were due to the combination of deeper soil with larger soil volume.

关键词： biodiversity effects nutrient limitation resource partitioning root competition soil depth

Simulating the evolution of a clonal trait in plants with sexual and vegetative reproduction

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Journal of Plant Ecology 2008年第3期1卷 161-171页

作者： Markus Fischer Eckart Winkler Bernhard schmid Institute of Plant Sciences University of BernAltenbergrain 21CH-3013 BernSwitzerland Institute for Biochemistry and Biology University of PotsdamMaulbeerallee 1D-14469 PotsdamGermany Department of Ecological Modelling Helmholtz Centre for Environmental Research UFZPO Box 500135D-04301 LeipzigGermany Institute of Environmental Sciences University of ZurichWinterthurerstrasse 190CH-8057 ZurichSwitzerland

Aims Phenotypic optimality models neglect ***,especially when heterozygous genotypes are fittest,evolving allele,genotype and phenotype frequencies may not correspond to predicted *** was not previously addressed for organisms with complex life *** Therefore,we modelled the evolution of a fitness-relevant trait of clonal plants,stolon internode *** explored the likely case of an asymmetric unimodal fitness profile with three model *** constant selection models(CSMs),which are gametic,but not spatially explicit,evolving allele frequencies in the one-locus and fiveloci cases did not correspond to optimum stolon internode length predicted by the spatially explicit,but not gametic,phenotypic *** deviation was due to the asymmetry of the fitness ***,spatially explicit individual-based(SEIB)modeling allowed us relaxing the CSM assumptions of constant selection with exclusively sexual *** findings For entirely vegetative or sexual reproduction,predictions of the gametic SEIB model were close to the ones of spatially explicit nongametic phenotypic models,but for mixed modes of reproduction they approximated those of gametic,not spatially explicit ***,in contrast to gametic SEIB models,phenotypic models and,especially for few loci,also CSMs can be very *** conclude that the evolution of traits governed by few quantitative trait loci appears hardly predictable by simple models,that genetic algorithms aiming at technical optimization may actually miss the optimum and that selection may lead to loci with smaller effects in derived compared with ancestral lines.

关键词： clonal plants ecological and evolutionary modelling genetic variation life-history evolution optimal life histories simulation model