The article is dedicated to measuring the thickness of step height standards using the author's version of the variable wavelength interferometer (VAWI) in the reflected-light mode, where the interference pattern is created by the combination of two Wollaston prisms. The element of novelty consists in replacing the traditional search for the coincidence of fringes in the object and background with a continuous measurement of their periods and phases relative to the zero-order fringe. The resulting system of sinusoids is then analyzed using two methods: the classical one and the second utilizing the criterion of uniform thickness.
View Article and Find Full Text PDFDespite scratching behavior in owned domestic cats being a self-motivated and natural behavior, it is commonly reported as a behavior problem by owners when it results in damage to household items. The objectives of this study were to use a cross-sectional survey targeting cat owners within the United States and Canada, to explore perspectives on cat scratching behavior and management strategies, as well as identify factors that influence the performance of inappropriate scratching behavior in the household. A total of 2465 cat owners participated in the survey and three mixed logistic regression models were generated to explore associations between (1) cat demographic factors, (2) provisions of enrichment, and (3) owner demographic and management factors with owner reports of problematic scratching.
View Article and Find Full Text PDFBackground: Fast Track Pathways (FTP) directed at reducing length of stay (LOS) and overall costs are being increasingly implemented for emergency surgeries. The purpose of this study is to evaluate implementation of a FTP for Emergency General Surgery (EGS) at an academic medical center (AMC).
Methods: The study included 165 patients at an AMC between 2016 and 2018 who underwent laparoscopic appendectomy (LA), laparoscopic cholecystectomy (LC), or laparoscopic inguinal hernia repair (LI).
Background: Robot-assisted transabdominal preperitoneal inguinal hernia repair (rTAPP-IHR) is a safe and feasible approach for hernias of varying etiology. We aim to present a single surgeon's learning curve (LC) of this technique based on operative times, while accounting for bilaterality and complexity.
Methods: This is a retrospective cohort analysis of patients who underwent rTAPP-IHR over a period of 5 years.
Surg Laparosc Endosc Percutan Tech
November 2020
Background: Cumulative sum (CUSUM) learning curves (LCs) are useful to analyze individual performance and to evaluate the acquisition of new skills and the evolution of those skills as experience is accumulated. The purpose of this study is to present a CUSUM LC based on the operative times of robotic intraperitoneal onlay mesh (rIPOM) ventral hernia repair (VHR) and identify differences observed throughout its phases.
Materials And Methods: Patients who underwent rIPOM repair for elective, midline, and primary hernias were included.
J Laparoendosc Adv Surg Tech A
July 2021
Robotic Rives-Stoppa ventral hernia repair (rRS-VHR) is a minimally invasive technique that incorporates extraperitoneal mesh placement, using either transabdominal or totally extraperitoneal access. An understanding of its learning curve and technical challenges may guide and encourage its adoption. We aim at evaluating the rRS-VHR learning curve based on operative times while accounting for adverse outcomes.
View Article and Find Full Text PDFPurpose: rTAPP-VHR is a novel technique which may be added to a surgeon's armamentarium. We aim to evaluate the robotic transabdominal preperitoneal ventral hernia repair (rTAPP-VHR) learning curve based on operative times while accounting for peritoneal flap integrity.
Methods: We performed a retrospective analysis of a database collected over a 7-year period.
Background: Timing of surgical treatment of facial fractures may vary with the patient age, injury type, and presence of polytrauma. Previous studies using national data sets have suggested that trauma patients with government insurance experience fewer operations, longer length of hospital stay (LOS), and worse outcomes compared with privately insured patients. The objective of this study is to compare treatment of facial fractures in patients with and without Medicaid insurance (excluding Medicare).
View Article and Find Full Text PDFBackground: Nationally, Medicaid enrollees with emergency surgical conditions experience worse outcomes overall when compared with privately insured patients. The goal of this study is to investigate disparities in the treatment of cholecystitis based on insurance type and to identify contributing factors.
Methods: Adults with cholecystitis at a safety-net hospital in Central Massachusetts from 2017-2018 were included.
Fast excitatory synaptic transmission in the mammalian central nervous system is mediated by glutamate-activated α-amino-5-methyl-3-hydroxy-4-isoxazole propionate (AMPA) receptors. In neurons, AMPA receptors coassemble with transmembrane AMPA receptor regulatory proteins (TARPs). Assembly with TARP γ8 alters the biophysical properties of the receptor, producing resensitization currents in the continued presence of glutamate.
View Article and Find Full Text PDFBackground: Studies using national data sets have suggested that insurance type drives a disparity in the care of emergency surgery patients. Large databases lack the granularity that smaller, single-institution series may provide. The goal of this study is to identify factors that may account for differences in care between Medicaid and non-Medicaid enrollees with appendicitis in central Massachusetts.
View Article and Find Full Text PDFBiochim Biophys Acta Biomembr
January 2020
Kainate receptors, which are glutamate activated excitatory neurotransmitter receptors, predominantly exist as heteromers of GluK2 and GluK5 subunits in the mammalian central nervous system. There are currently no structures of the full-length heteromeric kainate receptors. Here, we have used single molecule FRET to determine the specific arrangement of the GluK2 and GluK5 subunits within the dimer of dimers configuration in a full-length receptor.
View Article and Find Full Text PDFKainate receptors are glutamate-gated cation-selective channels involved in excitatory synaptic signaling and are known to be modulated by ions. Prior functional and structural studies suggest that the dimer interface at the agonist-binding domain plays a key role in activation, desensitization, and ion modulation in kainate receptors. Here we have used fluorescence-based methods to investigate the changes and conformational heterogeneity at these interfaces associated with the resting, antagonist-bound, active, desensitized, and ion-modulated states of the receptor.
View Article and Find Full Text PDFSingle-molecule fluorescence energy transfer methods allow us to determine the complete structural landscape between the donor and acceptor fluorophores introduced on the protein of interest. This method is particularly attractive to study ion channel proteins as single-molecule current recordings have been used to study the function of these proteins for several decades. Here we describe the smFRET method used to study glutamate receptors.
View Article and Find Full Text PDFRecent studies have shown that the small GTPase KRAS adopts multiple orientations with respect to the plane of anionic model membranes, whereby either the three C-terminal helices or the three N-terminal β-strands of the catalytic domain face the membrane. This has functional implications because, in the latter, the membrane occludes the effector-interacting surface. However, it remained unclear how membrane reorientation occurs and, critically, whether it occurs in the cell in which KRAS operates as a molecular switch in signaling pathways.
View Article and Find Full Text PDFBackground: Small bowel lesions (SBL) are rare, representing diagnostic and management challenges. The purpose of this cross-sectional study was to evaluate diagnostic modalities used and management practices of patients with SBL at an advanced endoscopic referral center.
Methods: We analyzed patients undergoing surgical management for SBL from 2005 to 2015 at a single tertiary care center.
Background: is a genus of mites living predominantly in mammalian pilosebaceous units. They are commonly detected in the skin of face, with increasing numbers in inflammatory lesions. Causation between mites and inflammatory diseases, such as rosacea, blepharitis, perioral and seborrhoeic dermatitis or chalazion, is controversially discussed.
View Article and Find Full Text PDFSurg Laparosc Endosc Percutan Tech
October 2016
Background: Percutaneous cholecystostomy tube placement has widely been used as an alternative treatment to cholecystectomy, especially in advanced disease or critically ill patients. Reported postprocedural complication rates have varied significantly over the last decade. The goal of this study is to evaluate the safety of percutaneous cholecystostomy tube treatment in critically ill patients.
View Article and Find Full Text PDFBackground: Sepsis from bacteremia occurs in 250,000 cases annually in the United States, has a mortality rate as high as 60%, and is associated with a poorer prognosis than localized infection. Because of these high figures, empiric antibiotic administration for patients with systemic inflammatory response syndrome (SIRS) and suspected infection is the second most common indication for antibiotic administration in intensive care units (ICU)s. However, overuse of empiric antibiotics contributes to the development of opportunistic infections, antibiotic resistance, and the increase in multi-drug-resistant bacterial strains.
View Article and Find Full Text PDFSurg Laparosc Endosc Percutan Tech
October 2014
Purpose: Determine which management strategy is ideal for patients with acute cholecystitis.
Materials And Methods: Prospective enrollment between August 2009 and March 2011. Large academic center.
Myxococcus xanthus is a model organism for studying bacterial social behaviors due to its ability to form complex multi-cellular structures. Knowledge of M. xanthus surface gliding motility and the mechanisms that coordinated it are critically important to our understanding of collective cell behaviors.
View Article and Find Full Text PDFMyxococcus xanthus cells self-organize into periodic bands of traveling waves, termed ripples, during multicellular fruiting body development and predation on other bacteria. To investigate the mechanistic basis of rippling behavior and its physiological role during predation by this Gram-negative soil bacterium, we have used an approach that combines mathematical modeling with experimental observations. Specifically, we developed an agent-based model (ABM) to simulate rippling behavior that employs a new signaling mechanism to trigger cellular reversals.
View Article and Find Full Text PDFBackground: Management of patients with severe acute cholecystitis (AC) remains controversial. In settings where laparoscopic cholecystectomy (LC) can be technically challenging or medical risks are exceedingly high, surgeons can choose between different options, including LC conversion to open cholecystectomy or surgical cholecystostomy tube (CCT) placement, or initial percutaneous CCT. We reviewed our experience treating complicated AC with CCT at a tertiary-care academic medical center.
View Article and Find Full Text PDF