Methodological Impact on Curing Kinetics of Bone Cement Based on Poly (Styrene--Methyl Methacrylate)-2D Nanofiller Nanocomposites.

Herein, we report the methodological impact on the curing kinetics of bone cement based on polymer nanocomposites prepared using different methods. Poly (styrene--methylmethacrylate)-2D nanofiller nanocomposites (P(S-MMA)-2D Nanofiller) were prepared using bulk and suspension polymerization methods to study the effect of the different methods. The prepared nanocomposites were well-characterized for chemical, thermal, mechanical, and structural characteristics using Fourier Transform Infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), nano-indentation, and scanning electron microscopy (SEM) techniques, respectively.

Flexible and Freestanding MoS/Graphene Composite for High-Performance Supercapacitors.

Two-dimensional atomically thick materials such as graphene and layered molybdenum disulfide (MoS) have been studied as potential energy storage materials because of their high specific surface area, potential redox activity, and mechanical flexibility. However, because of the layered structure restacking and poor electrical conductivity, these materials are unable to attain their full potential. Composite electrodes made of a mixture of graphene and MoS have been shown to partially resolve these issues in the past, although their performance is still limited by inadequate mixing at the nanoscale.

Insight into thermo-mechanical enhancement of polymer nanocomposites coated microsand proppants for hydraulic fracturing.

The present work reports the fabrication of ultra-high strength microsand proppants (100 mesh) through a polymer nanocomposite dual coating approach and gives insight into their thermo-mechanical reinforcements. The dual coating can be of 3D-cross-linked poly(styrene-methyl methacrylate)/divinylbenzene) (PS-PMMA/DVB) porous network and thermally cross-linked epoxy with graphene nanosheets. The inner layer of PS-PMMA/DVB was prepared using bulk polymerization of styrene (S) and methyl methacrylate (MMA) at 70 °C with a free radical initiator azobisisobutyronitrile (AIBN).

Robot Navigation Based on Potential Field and Gradient Obtained by Bilinear Interpolation and a Grid-Based Search.

The original concept of the artificial potential field in robot path planning has spawned a variety of extensions to address its main weakness, namely the formation of local minima in which the robot may be trapped. In this paper, a smooth navigation function combining the Dijkstra-based discrete static potential field evaluation with bilinear interpolation is proposed. The necessary modifications of the bilinear interpolation method are developed to make it applicable to the path-planning application.

Microwave Irradiation Synthesis and Characterization of Reduced-(Graphene Oxide-(Polystyrene-Polymethyl Methacrylate))/Silver Nanoparticle Nanocomposites and their Anti-Microbial Activity.

Herein, we report a facile process for the preparation of styrene and methyl-methacrylate copolymer nanocomposites containing reduced graphene oxide and silver nanoparticles ((R-(GO-(PS-PMMA))/AgNPs)) by using (i) microwave irradiation (MWI) to obtain R-(GO-(PS-PMMA))/AgNPs and (ii) the in situ bulk polymerization technique to produce RGO/AgNPs-(PS-PMMA). Various characterization techniques, including FT-IR, XPS, Raman spectroscopy, XRD, SEM, HR-TEM, DSC, and TGA analysis, were used to characterize the prepared nanocomposites. The Berkovich nanoindentation method was employed to determine the hardness and elastic modulus of the nanocomposites.

Li-Ion Capacitor Integrated with Nano-network-Structured Ni/NiO/C Anode and Nitrogen-Doped Carbonized Metal-Organic Framework Cathode with High Power and Long Cyclability.

Lithium-ion capacitors (LICs) represent a new type of energy-storage devices, which have combined merits of high energy density Li-ion battery and high power density supercapacitor. Nevertheless, one significant challenge for LICs is the imbalanced kinetics between the fast capacitive cathode and relatively slow intercalation anode that limit the energy-storage performance. Here, the asymmetric LIC devices were developed based on a nitrogen-doped, carbonized zeolitic imidazolate framework (ZIF-8) cathode and a three-dimensional, nano-network-structured, conversion reaction-based Ni/NiO/C anode.

Inclusion of non-target antigen in vaccination favors generation of OVA specific CD4 memory T cells.

Inducing long-lived memory T cells by sub-unit vaccines has been a challenge. Subunit vaccines containing single immunogenic target antigen from a given pathogen have been designed with the presumption of mimicking the condition associated with natural infection, but fail to induce quality memory responses. In this study, we have included non-target antigens with vaccine candidate, OVA, in the inoculum containing TLR ligands to suffice the minimal condition of pathogen to provoke immune response.

Directed Self-Assembly of Star-Block Copolymers by Topographic Nanopatterns through Nucleation and Growth Mechanism.

Exploring the ordering mechanism and dynamics of self-assembled block copolymer (BCP) thin films under confined conditions are highly essential in the application of BCP lithography. In this study, it is aimed to examine the self-assembling mechanism and kinetics of silicon-containing 3-arm star-block copolymer composed of polystyrene (PS) and poly(dimethylsiloxane) blocks as nanostructured thin films with perpendicular cylinders and controlled lateral ordering by directed self-assembly using topographically patterned substrates. The ordering process of the star-block copolymer within fabricated topographic patterns with PS-functionalized sidewall can be carried out through the type of secondary (i.

Fabrication of Mesoporous Polystyrene Films with Controlled Porosity and Pore Size by Solvent Annealing for Templated Syntheses.

Herein, we aim to develop a facile method for the fabrication of mesoporous polystyrene (PS) films with controlled porosity and pore size by solvent annealing. A PS polymer film is solvent-annealed using N,N-dimethyl formamide (DMF) vapor for the development of phase separation, followed by rapidly cooling to the preset cryogenic temperature. Subsequently, a nonsolvent (methanol) is introduced to extract the crystalline DMF from the DMF-swollen PS, giving mesoporous PS with a network structure after the removal of DMF.

Aircraft Recirculation Filter for Air-Quality and Incident Assessment.

The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus.

Hydrophilic polymer nanofibre networks for rapid removal of aromatic compounds from water.

Hydrophobic mesoporous polymer nanofibre networks were converted to hydrophilic ones by a mild sulfonation reaction. The resultant mesoporous polystyrene with a large free surface area effectively captured water-soluble dye molecules and allowed aromatic compounds to rapidly permeate into the internal binding sites.

Flash freezing route to mesoporous polymer nanofibre networks.

There are increasing requirements worldwide for advanced separation materials with applications in environmental protection processes. Various mesoporous polymeric materials have been developed and they are considered as potential candidates. It is still challenging, however, to develop economically viable and durable separation materials from low-cost, mass-produced materials.

Hemosuccus pancreaticus: a rare cause of gastrointestinal bleeding.

Hemorrhage from the pancreatic duct, referred to as hemosuccus pancreaticus or pseudohemobilia, is a rare cause of gastrointestinal (GI) bleeding. This potentially life-threatening complication of pancreatitis may pose a significant diagnostic and therapeutic dilemma, especially in patients who do not exhibit symptoms such as abdominal pain, jaundice, or GI bleeding. Here we describe a 55-year-old male with a known history of chronic calcifying pancreatitis, who presented with repeated episodes of melena associated with paroxysms of abdominal pain and frequent drop in hemoglobin requiring hospitalization.

Use of the Tower of London - Drexel University, Second Edition (TOLDX) in adults with traumatic brain injury.

The Tower of London - Drexel University, Second Edition (TOL(DX)) was investigated in order to determine the efficacy of using this instrument in evaluating the impact of traumatic brain injury on cognitive functioning in adults. Performance on the TOL(DX) was compared among 56 individuals with complicated mild to severe traumatic brain injury ("sTBI"), 68 individuals with uncomplicated, mild traumatic brain injury ("mTBI"), and 124 demographically matched, healthy controls. Both TBI groups performed worse than controls on TOL(DX) measures of executive time (ET) and number of moves used (TMS), but only patients with sTBI were more likely to be impaired on TMS (i.

Absence of gastrointestinal pathogens in ileum tissue resected for necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) is one of the most common gastrointestinal emergencies in premature infants and has been linked with viral antigens in as much as 40% of cases in single-center cohorts. We examined 28 tissue sections from surgically resected ileum from 27 preterm infants with NEC from 2 separate institutions for 15 common bacterial, viral, and parasitic gastrointestinal pathogens using multiplex reverse transcriptase polymerase chain reaction amplification and suspension array detection methods. We did not detect infectious enteritis pathogens in any of the NEC tissues and conclude that gastrointestinal pathogens are a rare cause of NEC.

Exposure of flight attendants to pyrethroid insecticides on commercial flights: urinary metabolite levels and implications.

Pyrethroid insecticides have been used for disinsection of commercial aircrafts. However, little is known about the pyrethroids exposure of flight attendants. The objective of the study was to assess pyrethroids exposure of flight attendants working on commercial aircrafts through monitoring the urinary pyrethroids metabolite levels.

Embedded assessment of validity using the continuous visual memory test in patients with traumatic brain injury.

Retrospective review of a consecutive patient series (n = 115) referred for neuropsychological examinations for traumatic brain injury was undertaken to evaluate an embedded measure of symptom validity for the Continuous Visual Memory Test (CVMT). Performance on the Test of Memory Malingering (TOMM) and Word Memory Test (WMT) was used for classification. Individuals who failed the TOMM or WMT were almost six times more likely to fail the CVMT validity criteria than those who passed the TOMM or WMT.

Sampling scheme for pyrethroids on multiple surfaces on commercial aircrafts.

A wipe sampler for the collection of permethrin from soft and hard surfaces has been developed for use in aircraft. "Disinsection" or application of pesticides, predominantly pyrethrods, inside commercial aircraft is routinely required by some countries and is done on an as-needed basis by airlines resulting in potential pesticide dermal and inhalation exposures to the crew and passengers. A wipe method using filter paper and water was evaluated for both soft and hard aircraft surfaces.

Factor-analytic study of the Yale Global Tic Severity Scale.

We report on the factor structure of the Yale Global Tic Severity Scale. Participants were 76 children and adolescents diagnosed with tic disorders. Overall, the model proposed by Leckman et al.

The psychometric properties of the Brief Fear of Negative Evaluation Scale.

This study examined the psychometric properties of the Brief Fear of Negative Evaluation (BFNE) Scale in a nonclinical, nonstudent sample. Participants were administered the BFNE Scale, Beck Depression Inventory (BDI), and the UCLA Loneliness Scale. No differences were found across age, but women scored significantly higher on the BFNE Scale than men.

The effects of preexisting depression on cerebrovascular health outcomes in geriatric continuing care.

Background: Previous studies have investigated depression as the cause and outcome of vascular deficit in elderly persons.

Methods: The authors wanted to determine whether baseline depression is predictive of subsequent cardiovascular events in very elderly persons residing in a continuing care retirement community (n = 181).

Results: Controlling for demographic factors, both depression and the number of cardiovascular risk factors (CVRFs) at baseline were strongly predictive of stroke, whereas only CVRFs strongly predicted myocardial infarctions.

Improved extraction of ePTFE and medical adhesive modified defibrillation leads from the coronary sinus and great cardiac vein.

Background: Permanent leads with shocking coils for defibrillation therapy are sometimes implanted in the coronary sinus (CS) and great cardiac vein (GCV). These shocking coils, as documented by pathologic examination of animal investigations, often become tightly encapsulated by fibrosis and can be very difficult to remove.

Methods: One of three configurations of the Guidant model 7109 Perimeter coronary sinus shocking lead was implanted into the distal portion of the GCV of 24 sheep for up to 14 months.

Relationship of Indoor, Outdoor and Personal Air (RIOPA) study: study design, methods and quality assurance/control results.

The Relationship of Indoor, Outdoor and Personal Air (RIOPA) Study was undertaken to evaluate the contribution of outdoor sources of air toxics, as defined in the 1990 Clean Air Act Amendments, to indoor concentrations and personal exposures. The concentrations of 18 volatile organic compounds (VOCs), 17 carbonyl compounds, and fine particulate matter mass (PM(2.5)) were measured using 48-h outdoor, indoor and personal air samples collected simultaneously.

Use of stable isotopically labeled benzene to evaluate environmental exposures.

The use of stable, isotopically labeled compounds in controlled exposure experiments at environmentally relevant levels allows for the distinguishing of urinary metabolites associated with known exposure from background levels generally present in the urine. Exposures of volunteers to (13)C-benzene for 2 h at 40+/-10 p.p.