The infrared structure of the quark-antiquark scattering kernel in quantumchromodynamics: A clue to the nature of the quark binding potential?

1977 ◽  
Vol 71 (2) ◽  
pp. 381-384 ◽  
Author(s):  
Enrico C. Poggio
Keyword(s):  
Binding Potential ◽  
Scattering Kernel

Quantitative accuracy of serotonergic neurotrans-mission imaging with high-resolution 123I SPECT

2004 ◽  
Vol 43 (06) ◽  
pp. 185-189 ◽  
Author(s):  
J. T. Kuikka
Keyword(s):  
High Resolution ◽  
Scatter Correction ◽  
Region Of Interest ◽  
Binding Potential ◽  
Partial Volume ◽  
Therapeutic Drugs ◽  
Quantitative Accuracy ◽  
Critical Error ◽  
Statistical Noise

Summary Aim: Serotonin transporter (SERT) imaging can be used to study the role of regional abnormalities of neurotransmitter release in various mental disorders and to study the mechanism of action of therapeutic drugs or drugs’ abuse. We examine the quantitative accuracy and reproducibility that can be achieved with high-resolution SPECT of serotonergic neurotransmission. Method: Binding potential (BP) of 123I labeled tracer specific for midbrain SERT was assessed in 20 healthy persons. The effects of scatter, attenuation, partial volume, mis-registration and statistical noise were estimated using phantom and human studies. Results: Without any correction, BP was underestimated by 73%. The partial volume error was the major component in this underestimation whereas the most critical error for the reproducibility was misplacement of region of interest (ROI). Conclusion: The proper ROI registration, the use of the multiple head gamma camera with transmission based scatter correction introduce more relevant results. However, due to the small dimensions of the midbrain SERT structures and poor spatial resolution of SPECT, the improvement without the partial volume correction is not great enough to restore the estimate of BP to that of the true one.

New scattering kernel for gas-surface interaction

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1000-1011
Author(s):  
C. Cercignani ◽  
M. Lampis
Keyword(s):  
Surface Interaction ◽  
Scattering Kernel

A Review on Quantum Dots: Synthesis to In- silico Analysis as Next Generation Antibacterial Agents

2019 ◽  
Vol 20 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Sounik Manna ◽  
Munmun Ghosh ◽  
Ranadhir Chakraborty ◽  
Sudipto Ghosh ◽  
Santi M. Mandal
Keyword(s):  
Quantum Dots ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Antimicrobial Properties ◽  
Binding Potential ◽  
Antibacterial Drug ◽  
Next Generation ◽  
Mechanism Of Reaction ◽  
High Level ◽  
Membrane Components

Succumbing to Multi-Drug Resistant (MDR) bacteria is a great distress to the recent health care system. Out of the several attempts that have been made to kill MDR pathogens, a few gained short-lived success. The failures, of the discovered or innovated antimicrobials, were mostly due to their high level of toxicity to hosts and the phenomenal rate of developing resistance by the pathogens against the new arsenal. Recently, a few quantum dots were tested against the pathogenic bacteria and therefore, justified for potential stockpiling of next-generation antibacterial agents. The key players for antimicrobial properties of quantum dots are considered to be Reactive Oxygen Species (ROS). The mechanism of reaction between bacteria and quantum dots needs to be better understood. They are generally targeted towards the cell wall and membrane components as lipoteichoic acid and phosphatidyl glycerol of bacteria have been documented here. In this paper, we have attempted to simulate ZnS quantum dots and have analysed their mechanism of reaction as well as binding potential to the above bacterial membrane components using CDOCKER. Results have shown a high level of antibacterial activity towards several pathogenic bacteria which specify their potentiality for future generation antibacterial drug development.

scholarly journals Treadmilling FtsZ polymers drive the directional movement of sPG-synthesis enzymes via a Brownian ratchet mechanism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joshua W. McCausland ◽  
Xinxing Yang ◽  
Georgia R. Squyres ◽  
Zhixin Lyu ◽  
Kevin E. Bruce ◽  
...  
Keyword(s):  
Cell Wall ◽  
Single Molecule ◽  
Theoretical Modelling ◽  
Binding Potential ◽  
Central Component ◽  
Macromolecular Complex ◽  
Bacterial Cells ◽  
Brownian Ratchet ◽  
Ratchet Mechanism ◽  
Directional Movement

AbstractThe FtsZ protein is a central component of the bacterial cell division machinery. It polymerizes at mid-cell and recruits more than 30 proteins to assemble into a macromolecular complex to direct cell wall constriction. FtsZ polymers exhibit treadmilling dynamics, driving the processive movement of enzymes that synthesize septal peptidoglycan (sPG). Here, we combine theoretical modelling with single-molecule imaging of live bacterial cells to show that FtsZ’s treadmilling drives the directional movement of sPG enzymes via a Brownian ratchet mechanism. The processivity of the directional movement depends on the binding potential between FtsZ and the sPG enzyme, and on a balance between the enzyme’s diffusion and FtsZ’s treadmilling speed. We propose that this interplay may provide a mechanism to control the spatiotemporal distribution of active sPG enzymes, explaining the distinct roles of FtsZ treadmilling in modulating cell wall constriction rate observed in different bacteria.

High-Throughput Affinity Selection Mass Spectrometry Using SAMDI-MS to Identify Small-Molecule Binders of the Human Rhinovirus 3C Protease

2021 ◽  
pp. 247255522110232
Author(s):  
Michael D. Scholle ◽  
Doug McLaughlin ◽  
Zachary A. Gurard-Levin
Keyword(s):  
Mass Spectrometry ◽  
Drug Discovery ◽  
High Throughput ◽  
High Throughput Screening ◽  
Human Rhinovirus ◽  
Binding Potential ◽  
Affinity Selection ◽  
Response Curves ◽  
Desorption Ionization ◽  
Self Assembled

Affinity selection mass spectrometry (ASMS) has emerged as a powerful high-throughput screening tool used in drug discovery to identify novel ligands against therapeutic targets. This report describes the first high-throughput screen using a novel self-assembled monolayer desorption ionization (SAMDI)–ASMS methodology to reveal ligands for the human rhinovirus 3C (HRV3C) protease. The approach combines self-assembled monolayers of alkanethiolates on gold with matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry (MS), a technique termed SAMDI-ASMS. The primary screen of more than 100,000 compounds in pools of 8 compounds per well was completed in less than 8 h, and informs on the binding potential and selectivity of each compound. Initial hits were confirmed in follow-up SAMDI-ASMS experiments in single-concentration and dose–response curves. The ligands identified by SAMDI-ASMS were further validated using differential scanning fluorimetry (DSF) and in functional protease assays against HRV3C and the related SARS-CoV-2 3CLpro enzyme. SAMDI-ASMS offers key benefits for drug discovery over traditional ASMS approaches, including the high-throughput workflow and readout, minimizing compound misbehavior by using smaller compound pools, and up to a 50-fold reduction in reagent consumption. The flexibility of this novel technology opens avenues for high-throughput ASMS assays of any target, thereby accelerating drug discovery for diverse diseases.

scholarly journals Genome-wide binding potential and regulatory activity of the glucocorticoid receptor’s monomeric and dimeric forms

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas A. Johnson ◽  
Ville Paakinaho ◽  
Sohyoung Kim ◽  
Gordon L. Hager ◽  
Diego M. Presman
Keyword(s):  
Receptor Binding ◽  
Site Response ◽  
Physiological Role ◽  
Binding Potential ◽  
Open Chromatin ◽  
Imaging Data ◽  
Response Elements ◽  
Genome Wide ◽  
Genomic Studies

AbstractA widely regarded model for glucocorticoid receptor (GR) action postulates that dimeric binding to DNA regulates unfavorable metabolic pathways while monomeric receptor binding promotes repressive gene responses related to its anti-inflammatory effects. This model has been built upon the characterization of the GRdim mutant, reported to be incapable of DNA binding and dimerization. Although quantitative live-cell imaging data shows GRdim as mostly dimeric, genomic studies based on recovery of enriched half-site response elements suggest monomeric engagement on DNA. Here, we perform genome-wide studies on GRdim and a constitutively monomeric mutant. Our results show that impairing dimerization affects binding even to open chromatin. We also find that GRdim does not exclusively bind half-response elements. Our results do not support a physiological role for monomeric GR and are consistent with a common mode of receptor binding via higher order structures that drives both the activating and repressive actions of glucocorticoids.

scholarly journals Preclinical Evaluation of [18F]FACH in Healthy Mice and Piglets: An 18F-Labeled Ligand for Imaging of Monocarboxylate Transporters with PET

2021 ◽  
Vol 22 (4) ◽  
pp. 1645
Author(s):  
Daniel Gündel ◽  
Masoud Sadeghzadeh ◽  
Winnie Deuther-Conrad ◽  
Barbara Wenzel ◽  
Paul Cumming ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Ex Vivo ◽  
Specific Binding ◽  
Monocarboxylate Transporters ◽  
Binding Potential ◽  
Kidney Cortex ◽  
Binding Studies ◽  
Imaging Tool ◽  
Pre Treatment

The expression of monocarboxylate transporters (MCTs) is linked to pathophysiological changes in diseases, including cancer, such that MCTs could potentially serve as diagnostic markers or therapeutic targets. We recently developed [18F]FACH as a radiotracer for non-invasive molecular imaging of MCTs by positron emission tomography (PET). The aim of this study was to evaluate further the specificity, metabolic stability, and pharmacokinetics of [18F]FACH in healthy mice and piglets. We measured the [18F]FACH plasma protein binding fractions in mice and piglets and the specific binding in cryosections of murine kidney and lung. The biodistribution of [18F]FACH was evaluated by tissue sampling ex vivo and by dynamic PET/MRI in vivo, with and without pre-treatment by the MCT inhibitor α-CCA-Na or the reference compound, FACH-Na. Additionally, we performed compartmental modelling of the PET signal in kidney cortex and liver. Saturation binding studies in kidney cortex cryosections indicated a KD of 118 ± 12 nM and Bmax of 6.0 pmol/mg wet weight. The specificity of [18F]FACH uptake in the kidney cortex was confirmed in vivo by reductions in AUC0–60min after pre-treatment with α-CCA-Na in mice (−47%) and in piglets (−66%). [18F]FACH was metabolically stable in mouse, but polar radio-metabolites were present in plasma and tissues of piglets. The [18F]FACH binding potential (BPND) in the kidney cortex was approximately 1.3 in mice. The MCT1 specificity of [18F]FACH uptake was confirmed by displacement studies in 4T1 cells. [18F]FACH has suitable properties for the detection of the MCTs in kidney, and thus has potential as a molecular imaging tool for MCT-related pathologies, which should next be assessed in relevant disease models.

scholarly journals Paired-Agent Fluorescence Molecular Imaging of Sentinel Lymph Nodes Using Indocyanine Green as a Control Agent for Antibody-Based Targeted Agents

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Chengyue Li ◽  
Xiaochun Xu ◽  
Nathan McMahon ◽  
Omar Alhaj Ibrahim ◽  
Husain A. Sattar ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Lymph Nodes ◽  
Indocyanine Green ◽  
Metastatic Breast ◽  
Control Agent ◽  
Sentinel Lymph Nodes ◽  
Imaging Agent ◽  
Binding Potential ◽  
Cancer Spread ◽  
Kinetics Of

Purpose. Paired-agent molecular imaging methods, which employ coadministration of an untargeted, “control” imaging agent with a targeted agent to correct for nonspecific uptake, have been demonstrated to detect 200 cancer cells in a mouse model of metastatic breast cancer. This study demonstrates that indocyanine green (ICG), which is approved for human use, is an ideal control agent for future paired-agent studies to facilitate eventual clinical translation. Methods. The kinetics of ICG were compared with a known ideal control imaging agent, IRDye-700DX-labeled antibody in both healthy and metastatic rat popliteal lymph nodes after coadministration, intradermally in the footpad. Results. The kinetics of ICG and antibody-based imaging agent in tumor-free rat lymph nodes demonstrated a strong correlation with each other (r = 0.98, p<0.001) with a measured binding potential of −0.102 ± 0.03 at 20 min postagent injection, while the kinetics of ICG and targeted imaging agent shows significant separation in the metastatic lymph nodes. Conclusion. This study indicated a potential for microscopic sensitivity to cancer spread in sentinel lymph nodes using ICG as a control agent for antibody-based molecular imaging assays.

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