The Experts below are selected from a list of 24351 Experts worldwide ranked by ideXlab platform

Michelle D. Wang - One of the best experts on this subject based on the ideXlab platform.

  • Optical tweezers in single-molecule Biophysics
    Nature Reviews Methods Primers, 2021
    Co-Authors: Carlos J. Bustamante, Yann R. Chemla, Shixin Liu, Michelle D. Wang
    Abstract:

    This Primer on optical tweezers describes the instrumentation and experimental designs used in most single-molecule optical tweezers assays and discusses optical tweezers measurements in systems of biophysical interest such as DNA elasticity, protein and RNA folding, and molecular motors. Optical tweezers have become the method of choice in single-molecule manipulation studies. In this Primer, we first review the physical principles of optical tweezers and the characteristics that make them a powerful tool to investigate single molecules. We then introduce the modifications of the method to extend the measurement of forces and displacements to torques and angles, and to develop optical tweezers with single-molecule fluorescence detection capabilities. We discuss force and torque calibration of these instruments, their various modes of operation and most common experimental geometries. We describe the type of data obtained in each experimental design and their analyses. This description is followed by a survey of applications of these methods to the studies of protein–nucleic acid interactions, protein/RNA folding and molecular motors. We also discuss data reproducibility, the factors that lead to the data variability among different laboratories and the need to develop field standards. We cover the current limitations of the methods and possible ways to optimize instrument operation, data extraction and analysis, before suggesting likely areas of future growth.

Ron Rowbotham - One of the best experts on this subject based on the ideXlab platform.

  • complications and recommended practices for electrosurgery in laparoscopy
    American Journal of Surgery, 2000
    Co-Authors: Mingping Wu, Chausu Ou, Shwuling Chen, Ron Rowbotham
    Abstract:

    BACKGROUND: Electrosurgery is one of the most commonly used energy systems in laparoscopic surgery. Two major categories of potential complications related to electrosurgery in laparoscopy are mechanical trauma and electrothermal injury. The latter can result from unrecognized energy transfer in the operational field or, less commonly, to unnoticed stray current outside the laparoscopic field of view. Stray current can result from insulation failure, direct coupling, or capacitive coupling. METHODS: We reviewed the literature concerning essential Biophysics of electrosurgery, including electrosurgical waveform differentiation, tissue effect, and variables that determine tissue effect. The incidence of electrosurgical injuries and possible mechanisms responsible for the injuries are discussed. Different types of injuries may result in different clinical manifestations and histopathological findings. Gross and microscopic pathological check-ups of the injury sites may distinguish between different mechanisms, and thus provide further clues postoperatively. RESULTS: Several recommended practices are proposed to avoid electrosurgical injury laparoscopically. To achieve electrosurgical safety and to prevent electrosurgical injuries, the surgical team should have a good understanding of the Biophysics of electrosurgery, the basis of equipment and general tissue effects, as well as the surgeon's spatial orientation and hand-eye coordination. Some intraoperative adjuvant procedures and newly developed safety devices have become available may aid to improve electrosurgical safety. CONCLUSIONS: Knowledge of the Biophysics of electrosurgery and the mechanisms of electrosurgical injury is important in recognizing potential complications of electrosurgery in laparoscopy. Procedures for prevention, intraoperative adjuvant maneuvers, early recognition of the injury with in-time salvage treatment, and alertness to postoperative warning signs can help reduce such complications.

  • Complications and recommended practices for electrosurgery in laparoscopy.
    American journal of surgery, 2000
    Co-Authors: Shwuling Chen, Ernest Y.t Yen, Ron Rowbotham
    Abstract:

    Abstract Background: Electrosurgery is one of the most commonly used energy systems in laparoscopic surgery. Two major categories of potential complications related to electrosurgery in laparoscopy are mechanical trauma and electrothermal injury. The latter can result from unrecognized energy transfer in the operational field or, less commonly, to unnoticed stray current outside the laparoscopic field of view. Stray current can result from insulation failure, direct coupling, or capacitive coupling. Methods: We reviewed the literature concerning essential Biophysics of electrosurgery, including electrosurgical waveform differentiation, tissue effect, and variables that determine tissue effect. The incidence of electrosurgical injuries and possible mechanisms responsible for the injuries are discussed. Different types of injuries may result in different clinical manifestations and histopathological findings. Gross and microscopic pathological check-ups of the injury sites may distinguish between different mechanisms, and thus provide further clues postoperatively. Results: Several recommended practices are proposed to avoid electrosurgical injury laparoscopically. To achieve electrosurgical safety and to prevent electrosurgical injuries, the surgical team should have a good understanding of the Biophysics of electrosurgery, the basis of equipment and general tissue effects, as well as the surgeon’s spatial orientation and hand-eye coordination. Some intraoperative adjuvant procedures and newly developed safety devices have become available may aid to improve electrosurgical safety. Conclusions: Knowledge of the Biophysics of electrosurgery and the mechanisms of electrosurgical injury is important in recognizing potential complications of electrosurgery in laparoscopy. Procedures for prevention, intraoperative adjuvant maneuvers, early recognition of the injury with in-time salvage treatment, and alertness to postoperative warning signs can help reduce such complications.

Steven M Block - One of the best experts on this subject based on the ideXlab platform.

Marcin Plodzien - One of the best experts on this subject based on the ideXlab platform.

  • simulating polaron Biophysics with rydberg atoms
    Scientific Reports, 2018
    Co-Authors: Marcin Plodzien, Tomasz Sowinski, S J J M F Kokkelmans
    Abstract:

    Transport of excitations along proteins can be formulated in a quantum physics context, based on the periodicity and vibrational modes of the structures. Numerically exact solutions of the corresponding equations are very challenging to obtain on classical computers. Approximate solutions based on the Davydov ansatz have demonstrated the possibility of stabilized solitonic excitations along the protein, however, experimentally these solutions have never been directly observed. Here we propose an alternative study of biophysical transport phenomena based on a quantum simulator composed of a chain of ultracold dressed Rydberg atoms, which allows for a direct observation of the Davydov phenomena. We show that there is an experimentally accessible range of parameters where the system directly mimics the Davydov equations and their solutions. Moreover, we show that such a quantum simulator has access to the regime in between the small and large polaron regimes, which cannot be described perturbatively.

  • simulating polaron Biophysics with rydberg atoms
    arXiv: Atomic Physics, 2017
    Co-Authors: Marcin Plodzien, Tomasz Sowinski, S J J M F Kokkelmans
    Abstract:

    Transport of excitations along proteins can be formulated in a quantum physics context, based on the periodicity and vibrational modes of the structures. Exact solutions are very challenging to obtain on classical computers, however, approximate solutions based on the Davydov ansatz have demonstrated the possibility of stabilized solitonic excitations along the protein. We propose an alternative study based on a chain of ultracold atoms. We investigate the experimental parameters to control such a quantum simulator based on dressed Rydberg atoms. We show that there is a feasible range of parameters where a quantum simulator can directly mimic the Davydov equations and their solutions. Such a quantum simulator opens up new directions for the study of transport phenomena in a biophysical context.

Carlos J. Bustamante - One of the best experts on this subject based on the ideXlab platform.

  • Optical tweezers in single-molecule Biophysics
    Nature Reviews Methods Primers, 2021
    Co-Authors: Carlos J. Bustamante, Yann R. Chemla, Shixin Liu, Michelle D. Wang
    Abstract:

    This Primer on optical tweezers describes the instrumentation and experimental designs used in most single-molecule optical tweezers assays and discusses optical tweezers measurements in systems of biophysical interest such as DNA elasticity, protein and RNA folding, and molecular motors. Optical tweezers have become the method of choice in single-molecule manipulation studies. In this Primer, we first review the physical principles of optical tweezers and the characteristics that make them a powerful tool to investigate single molecules. We then introduce the modifications of the method to extend the measurement of forces and displacements to torques and angles, and to develop optical tweezers with single-molecule fluorescence detection capabilities. We discuss force and torque calibration of these instruments, their various modes of operation and most common experimental geometries. We describe the type of data obtained in each experimental design and their analyses. This description is followed by a survey of applications of these methods to the studies of protein–nucleic acid interactions, protein/RNA folding and molecular motors. We also discuss data reproducibility, the factors that lead to the data variability among different laboratories and the need to develop field standards. We cover the current limitations of the methods and possible ways to optimize instrument operation, data extraction and analysis, before suggesting likely areas of future growth.