The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
E.v. Khots - One of the best experts on this subject based on the ideXlab platform.
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Fluctuating absorption coefficient of single molecule
Journal of Luminescence, 2003Co-Authors: I.s. Osad’ko, E.v. KhotsAbstract:A quantum mechanical theory for fluctuating absorption coefficient of the impurity center is used to explain spectral trajectory and Temporal Line broadening of a single terrylene molecule doped polyethylene.
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Scan Time Dependence of Single Molecule Optical Lines in Polymers and Glasses
Single Molecules, 2002Co-Authors: I.s. Osad'ko, E.v. KhotsAbstract:Analysis of various theories for optical bands of a guest molecule in fluctuating environment is carried out. It is shown that any proper dynamical theory for such a system must include initial conditions for two level systems (TLSs) of a solvent. True choice of the initial conditions can be carried out with the help of quantum mechanics principles. Our dynamic theory gives a theoretical basis for a “sudden jump model” which is used in many stochastic theories. Our theory describes the scan time dependence of single molecule optical Lines in more comprehensive fashion than any existing stochastic theory is able to carry out. Experimental data on Temporal Line broadening of single molecule optical Lines are treated with the help of our dynamical theory.
Manfred Tschabitscher - One of the best experts on this subject based on the ideXlab platform.
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Endoscopic reconstruction of the middle cranial fossa through a subTemporal keyhole using a pedicled deep Temporal fascial flap: a cadaveric study.
Neurosurgery, 2012Co-Authors: Mika Komatsu, Fuminari Komatsu, Antonio Di Ieva, Tooru Inoue, Manfred TschabitscherAbstract:Reconstruction of the skull base is essential to prevent postoperative leakage of cerebrospinal fluid (CSF). However, a reliable method of reconstructing the middle cranial fossa via a subTemporal keyhole is not available. To determine whether less invasive reconstruction of the middle cranial fossa under endoscopic guidance with a pedicled deep Temporal fascia approach via a subTemporal keyhole is feasible and useful. The middle cranial fossa in 4 fresh cadaver heads was reconstructed with a 4-mm 0° rigid endoscope. A subTemporal skin incision (subTemporal incision) was followed by 2 small skin incisions (Temporal Line incisions) made on the superior Temporal Line. The endoscope was inserted through the Temporal Line incisions, and then the deep Temporal fascia was separated from the superficial Temporal fascia and Temporal muscle under endoscopic view. A pedicled flap was harvested from the subTemporal incision and applied to the middle cranial fossa after subTemporal keyhole craniotomy. The pedicled deep Temporal fascial flap was flexible, long, and large enough to overlay skull base defects. This purely endoscopic technique using a pedicled deep Temporal fascial flap provided reliable reconstruction of the middle cranial fossa through a subTemporal keyhole. This technique would also be applicable in preventing CSF leakage or treating traumatic, acquired nontraumatic, or congenital encephalocele in the middle cranial fossa.
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Endoscopic reconstruction of the middle cranial fossa through a subTemporal keyhole using a pedicled deep Temporal fascial flap: a cadaveric study.
Neurosurgery, 2011Co-Authors: Mika Komatsu, Fuminari Komatsu, Antonio Di Ieva, Tooru Inoue, Manfred TschabitscherAbstract:BACKGROUND: Reconstruction of the skull base is essential to prevent postoperative leakage of cerebrospinal fluid (CSF). However, a reliable method of reconstructing the middle cranial fossa via a subTemporal keyhole is not available. OBJECTIVE: To determine whether less invasive reconstruction of the middle cranial fossa under endoscopic guidance with a pedicled deep Temporal fascia approach via a subTemporal keyhole is feasible and useful. METHODS: The middle cranial fossa in 4 fresh cadaver heads was reconstructed with a 4-mm 0° rigid endoscope. RESULTS: A subTemporal skin incision (subTemporal incision) was followed by 2 small skin incisions (Temporal Line incisions) made on the superior Temporal Line. The endoscope was inserted through the Temporal Line incisions, and then the deep Temporal fascia was separated from the superficial Temporal fascia and Temporal muscle under endoscopic view. A pedicled flap was harvested from the subTemporal incision and applied to the middle cranial fossa after subTemporal keyhole craniotomy. The pedicled deep Temporal fascial flap was flexible, long, and large enough to overlay skull base defects. CONCLUSION: This purely endoscopic technique using a pedicled deep Temporal fascial flap provided reliable reconstruction of the middle cranial fossa through a subTemporal keyhole. This technique would also be applicable in preventing CSF leakage or treating traumatic, acquired nontraumatic, or congenital encephalocele in the middle cranial fossa.
Bum-tae Kim - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the Indications and Treatment Results of Burr-Hole Drainage at the Maximal Thickness Area versus Twist-Drill Craniostomy at the Pre-Coronal Point for the Evacuation of Symptomatic Chronic Subdural Hematomas.
Journal of Korean Neurosurgical Society, 2014Co-Authors: Gi Hun Kim, Sun-chul Hwang, Soo Bin Im, Bum-tae Kim, Je Hoon Jeong, Dong-seong ShinAbstract:OBJECTIVE To analyze the clinical data and surgical results from symptomatic chronic subdural hematoma (CSDH) patients who underwent burr-hole drainage (BHD) at the maximal thickness area and twist-drill craniostomy (TDC) at the precoronal point. METHODS We analyzed data from 65 symptomatic CSDH patients who underwent TDC at the pre-coronal point or BHD at the maximal thickness area. For TDC, we defined the pre-coronal point to be 1 cm anterior to the coronal suture at the level of the superior Temporal Line. TDC was performed in patients with CSDH that extended beyond the coronal suture, as confirmed by preoperative CT scans. Medical records, radiological findings, and clinical performance were reviewed and analyzed. RESULTS Of the 65 CSDH patients, 13/17 (76.4%) with BHD and 42/48 (87.5%) with TDC showed improved clinical performance and radiological findings after surgery. Catheter failure was seen in 1/48 (2.4%) cases of TDC. Five patients (29.4%) in the BHD group and four patients (8.33%) in the TDC group underwent reoperations due to remaining hematomas, and they improved with a second operation, BHD or TDC. CONCLUSION Both BHD at the maximal thickness area and TDC at the pre-coronal point are safe and effective drainage methods for symptomatic CSDHs with reasonable indications.
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Safe entry point for twist-drill craniostomy of a chronic subdural hematoma
Journal of neurosurgery, 2009Co-Authors: Sun-chul Hwang, Soo Bin Im, Bum-tae KimAbstract:Object Twist-drill craniostomy (TDC) with closed-system drainage is an effective treatment option for chronic subdural hematoma (CSDH). Because the entry point for TDC has not been described in a definitive area, the aim of this study was to define the optimal twist-drill entry point for CSDH. Methods The authors selected 40 random cases involving selective catheter angiography of the external carotid artery, regardless of study purpose, to evaluate the course of the middle meningeal artery. Furthermore, 50 skull radiographs were reviewed to assess the relation of the vascular groove to the coronal suture. On the basis of the radiological anatomical study, the authors propose that the normal TDC entry point should be 1 cm anterior to the coronal suture at the level of the superior Temporal Line (STL). Thirty patients with symptomatic CSDH were treated using TDC with closed-system drainage at the proposed entry point. The thicknesses of the hematoma and the skull were measured at the proposed entry point. ...
Gordon L Hager - One of the best experts on this subject based on the ideXlab platform.
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Power-law behavior of transcription factor dynamics at the single-molecule level implies a continuum affinity model.
Nucleic acids research, 2021Co-Authors: David A Garcia, Gregory Fettweis, Diego M Presman, Ville Paakinaho, Christopher Jarzynski, Arpita Upadhyaya, Gordon L HagerAbstract:Single-molecule tracking (SMT) allows the study of transcription factor (TF) dynamics in the nucleus, giving important information regarding the diffusion and binding behavior of these proteins in the nuclear environment. Dwell time distributions obtained by SMT for most TFs appear to follow bi-exponential behavior. This has been ascribed to two discrete populations of TFs-one non-specifically bound to chromatin and another specifically bound to target sites, as implied by decades of biochemical studies. However, emerging studies suggest alternate models for dwell-time distributions, indicating the existence of more than two populations of TFs (multi-exponential distribution), or even the absence of discrete states altogether (power-law distribution). Here, we present an analytical pipeLine to evaluate which model best explains SMT data. We find that a broad spectrum of TFs (including glucocorticoid receptor, oestrogen receptor, FOXA1, CTCF) follow a power-law distribution of dwell-times, blurring the Temporal Line between non-specific and specific binding, suggesting that productive binding may involve longer binding events than previously believed. From these observations, we propose a continuum of affinities model to explain TF dynamics, that is consistent with complex interactions of TFs with multiple nuclear domains as well as binding and searching on the chromatin template.
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power law behaviour of transcription factor dynamics at the single molecule level implies a continuum affinity model
bioRxiv, 2020Co-Authors: David A Garcia, Gregory Fettweis, Diego M Presman, Ville Paakinaho, Christopher Jarzynski, Arpita Upadhyaya, Gordon L HagerAbstract:ABSTRACT Single-molecule tracking (SMT) allows the study of transcription factor (TF) dynamics in the nucleus, giving important information regarding the search and binding behaviour of these proteins in the nuclear environment. Dwell time distributions for most TFs have been described by SMT to follow bi-exponential behaviour. This is consistent with the existence of two discrete populations bound to chromatin in vivo, one non-specifically bound to chromatin (i.e. searching mode) and another specifically bound to target sites, as originally defined by decades of biochemical studies. However, alternative models have started to emerge, from multiple exponential components to power-law distributions. Here, we present an analytical pipeLine with an unbiased model selection approach based on different statistical metrics to determine the model that best explains SMT data. We found that a broad spectrum of TFs (including glucocorticoid receptor, oestrogen receptor, FOXA1, CTCF) follow a power-law distribution, blurring the Temporal Line between non-specific and specific binding, and suggesting that productive binding may involve longer binding events than previously thought. We propose a continuum of affinities model to explain the experimental data, consistent with the movement of TFs through complex interactions with multiple nuclear domains as well as binding and searching on the chromatin template.
I.s. Osad'ko - One of the best experts on this subject based on the ideXlab platform.
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Scan Time Dependence of Single Molecule Optical Lines in Polymers and Glasses
Single Molecules, 2002Co-Authors: I.s. Osad'ko, E.v. KhotsAbstract:Analysis of various theories for optical bands of a guest molecule in fluctuating environment is carried out. It is shown that any proper dynamical theory for such a system must include initial conditions for two level systems (TLSs) of a solvent. True choice of the initial conditions can be carried out with the help of quantum mechanics principles. Our dynamic theory gives a theoretical basis for a “sudden jump model” which is used in many stochastic theories. Our theory describes the scan time dependence of single molecule optical Lines in more comprehensive fashion than any existing stochastic theory is able to carry out. Experimental data on Temporal Line broadening of single molecule optical Lines are treated with the help of our dynamical theory.
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Dynamical theory for Temporal and thermal broadening and shift of the single molecule optical Line
Chemical Physics Letters, 1996Co-Authors: I.s. Osad'ko, Nikolai ZaitsevAbstract:Abstract A dynamical theory for thermal and Temporal Line broadening and shift is developed. A comparison with stochastic theories for spectral diffusion is carried out. The dependence of the Linewidth on time and the initial distribution for two-level systems is discussed.
