Polymer-Plasticizer Coatings for BTEX Detection Using Quartz Crystal Microbalance.

Sensing films based on polymer-plasticizer coatings have been developed to detect volatile organic compounds (VOCs) in the atmosphere at low concentrations (ppm) using quartz crystal microbalances (QCMs). Of particular interest in this work are the VOCs benzene, ethylbenzene, and toluene which, along with xylene, are collectively referred to as BTEX. The combinations of four glassy polymers with five plasticizers were studied as prospective sensor films for this application, with PEMA-DINCH (5%) and PEMA-DIOA (5%) demonstrating optimal performance. This work shows how the sensitivity and selectivity of a glassy polymer film for BTEX detection can be altered by adding a precise amount and type of plasticizer. To quantify the film saturation dynamics and model the absorption of BTEX analyte molecules into the bulk of the sensing film, a diffusion study was performed in which the frequency-time curve obtained via QCM was correlated with gas-phase analyte composition and the infinite dilution partition coefficients of each constituent. The model was able to quantify the respective concentrations of each analyte from binary and ternary mixtures based on the difference in response time (τ) values using a single polymer-plasticizer film as opposed to the traditional approach of using a sensor array. This work presents a set of polymer-plasticizer coatings that can be used for detecting and quantifying the BTEX in air, and discusses the selection of an optimum film based on τ, infinite dilution partition coefficients, and stability over a period of time.

Comprehensive analysis of repair/reinforcement materials for polymethyl methacrylate denture bases: mechanical and dimensional stability characteristics.

Fracture of complete denture is a common problem as acrylic resins hold inherent limitations. This necessitates affirmation of a selection criterion by evaluating the critical requirements of repair materials. The study intended to evaluate mechanical properties and dimensional stability of common denture base repair and reinforcement materials under standard experimental protocol. Seven types of denture reinforcement materials were chosen. Forty cuboidal samples were made in accordance with ISO 178 for three point bending test and divided to eight groups of five samples each. One group acted as control and samples of seven groups were sectioned and repaired with chosen materials. Five mechanical properties-fracture load, deflection, flexural strength, fracture toughness and elastic modulus were evaluated for all groups. Forty mandibular complete denture specimens were utilized for evaluating fracture load and deflection under loading. Dimensional stability after repair with seven different repair materials was analyzed in two planes (Linear and curvilinear) utilizing separate set of denture samples. Heat cure polymethyl methacrylate with polyethylene fiber was affirmed as material of choice based on this study as it accomplishes the most critical norms of requirement.

Fungal Keratitis Treatment Using Drug-Loaded Hyaluronic Acid Microgels.

Antifungal drug-loaded hyaluronic acid (HA) microgels using conjugation and encapsulation drug-loading techniques were utilized in the treatment of fungal keratitis. Natamycin (NAT) and amphotericin B (AMB) drugs were chemically linked to HA microgels by employing a chemical coupling agent to obtain conjugated (C-) HA:NAT and HA:AMB microgels. Also, these drugs were loaded into the HA microgel network during HA microgel preparation to attain encapsulated (E-) HA:NAT and HA:AMB microgels. The conjugation of drug molecules was confirmed by FT-IR spectra of bare and drug-loaded HA microgels. It was determined that the AMB loading amount was about 4-fold higher for E-HA:AMB in comparison to C-HA:AMB microgels. Furthermore, the antifungal activity of drug conjugated and encapsulated HA:NAT and HA:AMB microgels was tested on Fusarium sp. and compared with the effect of bare drug molecules as control for up to 15 days of incubation time by means of the disc diffusion technique. The antifungal activity of 200 µL at 20 mg/mL concentration of C-HA:NAT and C-HA:AMB microgels was not found to effectively inhibit Fusarium sp. growth after 1 day of incubation, whereas the same concentration of E-HA:NAT and E-HA:AMB microgels totally killed Fusarium sp. for up to 15 days. These E-HA:NAT and E-HA:AMB microgels show no cytotoxicity on the L929 fibroblast cells up to 1000 µg/mL concentration, whereas the free drug molecules destroy the cells even at 100 µg/mL concentration.

An articulating antibiotic spacer controls infection and improves pain and function in a degenerative septic hip.

BACKGROUND: Treating septic arthritis of the hip with coexisting advanced degenerative disease is challenging. The use of primary total hip arthroplasty (THA) has led to postoperative infection rates as high as 22%. Insertion of antibiotic spacers with subsequent reimplantation of a THA controls infection and improves pain and function in patients with periprosthetic infections. QUESTIONS/PURPOSES: We asked whether two-stage exchange for patients with degenerative joint disease (DJD) and coexisting septic arthritis would control infection and improve pain relief and function both during the period after insertion of the spacer and after conversion to THA. METHODS: We retrospectively reviewed 14 patients with severe DJD and either active or recent septic arthritis treated with débridement and insertion of a primary antibiotic-loaded cement spacer between 1996 and 2008. Ten patients underwent subsequent exchange to a permanent hip arthroplasty. Four patients did not undergo exchange to a permanent THA: two died from unrelated causes and two elected not to proceed with exchange because their spacer provided adequate function. We obtained a modified Harris hip score. The minimum clinical followup was 7 months (average, 28 months; range, 7-65 months) after insertion of the spacer. RESULTS: Mean pain scores improved from 6 to 34, and overall Harris hip scores improved from 11 to 67 at last followup with the spacer. Those who underwent definitive THA had further improvement in their mean Harris hip scores to 93. CONCLUSIONS: Articulating antibiotic spacers offer acceptable pain relief and function while the infection is treated in this unique group of patients. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Activating Sphingosine-1-phospahte signaling in endothelial cells increases myosin light chain phosphorylation to decrease endothelial permeability thereby inhibiting cancer metastasis.

Targeting the metastatic process to prevent disease dissemination in cancer remains challenging. One step in the metastatic cascade involves cancer cells transiting through the vascular endothelium after inflammation has increased the permeability of this cellular layer. Reducing inflammation-mediated gaps in the vascular endothelium could potentially be used to retard metastasis. This study describes the development of a novel ASR396-containing nanoparticle designed to activate the Sphingosine-1-Phosphate Receptor 1 (S1PR1) in order to tighten the junctions between the endothelial cells lining the vascular endothelium thereby inhibiting metastasis. ASR396 was derived from the S1PR1 agonist SEW2871 through chemical modification enabling the new compound to be loaded into a nanoliposome. ASR396 retained S1PR1 binding activity and the nanoliposomal formulation (nanoASR396) made it systemically bioavailable upon intravenous injection. Studies conducted in microvessels demonstrated that nanoASR396 significantly attenuated inflammatory mediator-induced permeability increase through the S1PR1 activation. Similarly, nanoASR396 inhibited gap formation mediated by inflammatory agents on an endothelial cell monolayer by decreasing levels of phosphorylated myosin light chain protein thereby inhibiting cellular contractility. In animal models, nanoASR396 inhibited lung metastasis by up to 80%, indicating its potential for retarding melanoma metastasis. Thus, a novel bioavailable nanoparticle-based S1PR1 agonist has been developed to negate the effects of inflammatory mediators on the vascular endothelium in order to reduce the metastatic dissemination of cancer cells.

Conformable surface acoustic wave biosensor for E-coli fabricated on PEN plastic film.

Over the last decades, great effort has gone into developing new biosensor technologies for applications in different fields such as disease diagnosis and detection of pollutants in water and food. Global developments in robotic, IoT technologies and in healthcare sensors require new flexible sensor technologies that are low cost and built from sustainable and reusable or recyclable materials. One of the most promising technologies is based on the development of surface acoustic wave (SAW) flexible biosensors, which are highly reproducible, reliable and wirelessly controllable. This work presents for the first time a novel aluminum nitride (AlN)-based conformable SAW immunosensor fabricated on recyclable polyethylene naphthalate. We apply it to the detection of E.Coli using a faster and innovative functionalization method that exploit Protein-A/antibody affinity. A higher sensitivity (Limit of detection-LoD, 6.54*105 CFU/ml) of the Lamb wave traveling on the polymeric device has been obtained in comparison with SAWs traveling on AlN on silicon substrate (LoD, 1.04*106 CFU/ml). Implementation of a finite element method allowed for the estimation of the single E.Coli mass of approximately 9*10-13 g. This work demonstrates the high biosensing potential of flexible polymeric SAW devices for bacteria contamination control in food chain, water and smart packaging.

Upper airway dimensions and sleep efficiency--three-dimensional imaging analysis and assessment of the nasopharyngeal appliance.

BACKGROUND: Reduction of upper airway (UA) dimensions during sleep is contemplated to cause reduced sleep efficiency (SE) but a definitive association is not affirmed. Efficacy of nasopharyngeal appliance (NPA) in management of UA resistance syndrome (UARS) has not been compared with mandibular repositioning splint (MRS). This study intended to assess relation of UA dimensions to SE and effectiveness of NPA. MATERIALS AND METHODS: Research had two phases: Case-control study to determine association between UA and SE; randomized control trial (with independent concurrent trial groups and double-blind design) to analyze treatment outcome with NPA. Subjects were categorized to three groups of 20 in each: A control group of healthy subjects (Group A); two "Randomly Assigned" sample groups of subjects with reduced SE (Groups B and C). Preliminary questionnaire for sleep analysis, Final data collection sheet (first and second case sheets) were recorded, cephalometric variables analyzed, and diagnostic overnight polysomnography was done to match and confirm selection criteria. Three-dimensional computed tomography was done to analyze airway dimensions before and after appliance placement. ANOVA and post-hoc tests were used for statistical analysis of results. CONCLUSIONS: Reduced UA dimension during sleep is associated with reduced SE; NPA gives better improvement for UARS than MRS.

An appraisal on increasing the occlusal vertical dimension in full occlusal rehabilitation and its outcome.

Increasing the occlusal vertical dimension for gaining sufficient restoration space in the management of severely worn dentition is being practiced. This contentious belief has lead to challenging thoughts regarding its effects on the Odonto-stomatognathic system. There are basic uncertainties and existing erroneous thoughts regarding the perception of increasing the occlusal vertical dimension. This manuscript will review the bite raising concepts and its outcome on the stomatognathic system.

Four novel prosthodontic methods for managing upper airway resistance syndrome: an investigative analysis revealing the efficacy of the new nasopharyngeal aperture guard appliance.

STATEMENT OF PROBLEM: Obstructive sleep apnea is the most frequent cause for insomnia in the populace. Snoring is mulled over as the potential factor that can lead the sequel to obstructive sleep apnea. Although the etiology and deterrence measures for snoring are yet to be undoubtedly clarified by our scientific sorority, various means of surgical corrections have been affirmed and put into practice, with a substantial degree of success. Despite this, it is implicit that a noninvasive method of managing obstructive sleep apnea is more relevant for overcoming this condition. PURPOSE: This manuscript intends to establish how snoring can be controlled prosthodontically by different modalities of scientifically defensible approaches. The most effective among the modalities was affirmed as the investigative analyses of the treatment outcomes with each modality. NOVEL METHODS: Four new methods of managing obstructive sleep apnea--uvula lift appliance, uvula and velopharynx lift appliance, nasopharyngeal aperture guard, and soft palate lift appliance were demonstrated through this article. CLINICAL REPORTS: The four new modalities stated and one conventional modality of mandibular advancement appliance for managing obstructive sleep apnea, a total of five types of appliance therapies, were described with case reports for each. INVESTIGATION: Five individuals undergoing the appliance therapy were chosen for each modality. The treatment outcome with each modality was examined by analysis of clinical predictors and also by means of standard investigation, with nasal and oral endoscopic analyses. RESULT: Among the five types of appliance therapies, the nasopharyngeal aperture guard provided the best treatment outcome in terms of clinical predictors and endoscopic analyses. CONCLUSION: Nasopharyngeal aperture guard, the novel method stated in this article is the better modality for managing obstructive sleep apnea, among the five different appliance therapies.

Single subcutaneous administration of RGDK-lipopeptide:rhPDGF-B gene complex heals wounds in streptozotocin-induced diabetic rats.

Development of effective therapeutics for chronic wounds remains a formidable clinical challenge. Deficiency of growth factors is of paramount importance among the multitude of factors contributing to the pathogenesis of diabetic wounds. Clinical interest has been witnessed in the past for exogenous applications of platelet derived growth factor B (PDGF-B) in chronic nonhealing wounds. However, accomplishing even modest favorable clinical effects in such topical applications requires large and repeated doses of PDGF-B proteins. Chronic wounds are being increasingly circumvented by gene therapy approach and to this end, cationic liposomes are emerging as promising nonviral carriers for delivering various growth factors encoding therapeutic genes to wound beds. However, as in case of topical application of growth factors, all the prior studies on the use of cationic liposomes in nonviral gene therapy of wounds involved repeated injections of cationic liposome:cDNA complexes over several weeks for ensuring complete wound healing. Herein, we show that a single subcutaneous administration of an electrostatic complex of rhPDGF-B plasmid, integrin receptor selective RGDK-lipopeptide 1 and cholesterol (as auxiliary lipid) is capable of healing wounds in streptozotocin-induced diabetic Sprague-Dawley rats (as model of chronic wounds). Western blot analysis revealed significant expression of rhPDGF-B in mouse fibroblast cells transfected with RGDK-lipopeptide 1:rhPDGF-B lipoplex. The transfection efficiencies of the RGDK-lipopeptide 1 in mouse and human fibroblast cells preincubated with various monoclonal anti-integrin receptor antibodies support the notion that the cellular uptake of the RGDK-lipopeptide 1:DNA complexes in fibroblast cells is likely to be selectively mediated by alpha5beta1 integrin receptors. Findings in the histopathological stainings using both hematoxylin and eosin (H & E) as well as Masson's Trichrome staining revealed a significantly higher degree of epithelization, keratization, fibrocollagenation and blood vessel formation in rats treated with RGDK-lipopeptide 1:rhPDGF compared to those in rats treated with vehicle alone.

Generalized coating route to silica and titania films with orthogonally tilted cylindrical nanopore arrays.

We describe a simple, inexpensive coating method to produce thin silica and titania films with surfactant templated, orthogonally tilted cylindrical nanopore arrays. These films can be deposited onto any substrate because orientation of the 2D hexagonally close packed (HCP) mesophases out of the plane of the film is directed by a chemically neutral sacrificial copolymer layer. Orientation of the HCP mesophases through the entire thickness of films cured in open air is achieved by limiting the coating thickness. This generalizes the coating method by making it possible to deposit oriented films on substrates of any curvature and size. We find a critical thickness between 70 and 100 nm, below which the triblock copolymer surfactant-templated HCP phase aligns completely out of the plane of glass and silicon wafer substrates. Above this thickness, the effect of the chemically neutral bottom layer does not propagate across the entire film, and alignment of the HCP mesophases parallel to the (nonpolar) air interface produces a mixed orientation.

Generation of 30-50 nm structures using easily fabricated, composite PDMS masks.

This communication demonstrates an approach to generate simple nanostructures with critical dimensions down to 30 nm over cm2-sized areas using composite PDMS masks. These masks were patterned with feature sizes down to 100 nm. When used in phase-shifting lithography, these masks generated arrays of structures in photoresist with line widths as small as 30 nm, slots in metal with features down to 40 nm, and wells in epoxy with diameters as small as 100 nm. The wells were used to prepare arrays of uniformly sized nanocrystals of salts.

The effect of tibial polyethylene insert design on range of motion: evaluation of in vivo knee kinematics by a computerized navigation system during total knee arthroplasty.

Computer-assisted navigation for total knee arthroplasty offers the unique opportunity to assess in vivo knee kinematics during surgery and implement changes whenever appropriate. Using a computerized navigation system, the effect of 2 tibial polyethylene insert designs on knee kinematics in general and knee range of motion (ROM) in particular was evaluated in 37 knee arthroplasties in 30 patients. The Scorpioflex tibial insert was found to provide a significant increase in mean extension, mean flexion, and overall ROM of the knee compared with the standard tibial insert (P<.005) without affecting knee ligamentous balance. Navigation is a very effective and useful tool for intraoperative assessment of knee kinematics and accurate recording of ROM. Based on the information obtained from the navigation software, the surgeon can implement changes in selection of the knee components with beneficial effects in knee kinematics in general and knee ROM in particular. This may, in turn, translate to better clinical outcome of the knee arthroplasty.

Isolated acetabular polyethylene exchange through the anterolateral approach.

Isolated exchange of an acetabular liner, in the presence of a well-fixed acetabular component, has become an established method for the management of polyethylene wear. Various experienced adult-reconstruction surgeons have noted a high incidence of instability following isolated liner exchange. We report the results of isolated liner exchange in 35 patients with polyethylene wear and osteolysis (16 patients) or polyethylene wear and instability (19 patients) with a minimum follow-up of 2 years. Isolated liner exchange was performed through an anterolateral approach in all cases. Postoperative dislocation occurred in 2 of the 35 patients (6%), both with polyethylene wear and osteolysis. Isolated liner exchange was successful in addressing instability in all 19 patients who presented with polyethylene wear and dislocation. Isolated acetabular liner exchange performed through an anterolateral approach carries an acceptable dislocation rate.