Polyethylene Terephthalates

Polyethlene terephthalate films were surface-modified with polyethylene oxide (18 500 g/mol) using a solution technique described previously. These films were investigated for their resistance to bacterial adhesion. Three bacterial strains most commonly associated with implant infections, Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa, were cultured in tryptic soya broth, human plasma and human serum on the polymeric substrates. Significant reductions (between 70 and 95%) in adherent bacteria were observed on the polyethylene oxide-modified substrates compared to the untreated control polyethylene terephthalate.

Th ere is still debate whether sintethic graft (polytetrafl uoroethylene or Dacron) is equivalent to vein as bypass graft material for the above-knee femoropopliteal bypass. Th erefore, we performed prospective randomized trial to compare vein with polytetrafl uoroethylene/dacron for femoropopliteal bypasses with the distal anastomosis above the knee. Between January  and June ,  femoropopliteal bypasses were performed. Th e indications for operation were severe claudication in  cases, rest pain in  cases, and ulceration in  cases. After randomization,  reversed saphenous venous bypasses and  polytetrafl uoroethylene/ dacron bypasses were performed. No perioperative mortality was seen, and  of the patients had minor infections of the wound, not resulting in loss of the bypass, the limb, or life. After  years,  of the patients had died and  were lost to follow-up. Only once saphenous vein was necessary for coronary artery bypass grafting. Primary patency rates after  years were , for venous bypass grafts and , for polytetrafl uoroethylene/dacron grafts (p=,). Secondary patency rates were , for vein and , for polytetrafl uoroethylene/dacron bypasses (p = ,). In the venous group,  bypasses failed, leading to four new bypasses. In the polytetrafl uoroethylene group,  bypasses failed, leading to  reinterventions. After  years of follow-up, we conclude that a bypass with saphenous vein has better patency rates at all intervals and needs fewer reoperations. Saphenous vein should be the graft material of choice for above-knee femoropopliteal bypasses and should not be preserved for reinterventions. Polytetrafl uoroethylene/dacron is an acceptable alternative if the saphenous vein is not available.

A novel infection-resistant biomaterial was created by applying the antibiotic Ciprofloxacin (Cipro) to a recently developed bifunctionalized polyethylene terephthalate ("polyester," Dacron) material using textile-dyeing technology. Dacron was modified via exposure to ethylenediamine (EDA) to create amine and carboxylic acid sites within the polymer backbone. Cipro was applied to the bifunctionalized Dacron construct under varied experimental conditions, with resulting antimicrobial activity determined via zone of inhibition. Dacron segments treated at a liquor ratio of 20:1, with 5% Cipro on weight of fabric (owf), at pH 8 for 4 h at 70°C followed by autoclaving showed antimicrobial activity for 78 days (length of study). Segments treated similarly but without autoclaving lost activity within 1 day. Dyeing time and temperature did not significantly affect antibiotic release/activity, but segments dyed at pHs higher or lower than 8 had less antimicrobial activity. The long-term infection resistance provided by this technique may answer major problems of infection from which implantable Dacron biomedical devices suffer.

This biomechanical study compared the fixation characteristics of horizontally or vertically implanted FasT-Fix devices (Smith & Nephew, Endoscopy Division, Andover, MA) consisting of two 5-mm PLLA suture T-bar anchors with a pretied self-sliding knot (No. 0 nonabsorbable, USP, braided polyester suture material) and the RapidLoc device (Mitek Surgical Products, Westwood, MA) consisting of a PLLA T-bar anchor or "backstop," a connecting suture (No. 2 nonbiodegradable Ethibond; Ethicon, Somerville, NJ), and a PLLA grommet, for repairing posterior third lesions in human menisci. Type of Study: Controlled laboratory biomechanical study. Methods: After repair of a vertical longitudinal meniscus lesion with either vertically or horizontally implanted FasT-Fix devices or RapidLoc devices, 3 groups of 6 specimens underwent cyclic loading (5 mm/minute, cycling between 5 and 50 N at 1 Hz for 500 cycles) before load to failure testing on a servo hydraulic device. One-way analysis of variance and Tukey HSD post hoc tests were used to evaluate group differences (P Ͻ .05). Results: The vertical FasT-Fix device group (3.2 Ϯ 0.49 mm) had less displacement after cyclic testing than either the horizontal FasT-Fix (4.4 Ϯ 0.73 mm, P ϭ .003) or the RapidLoc (4.6 Ϯ 0.22 mm, P ϭ .002) device groups. The vertical FasT-Fix device group had greater stiffness during cyclic testing (14.4 Ϯ 2.1 N/mm) than the horizontal FasT-Fix (10.4 Ϯ 1.6 N/mm, P ϭ .0001) or the RapidLoc (9.7 Ϯ 0.44 N/mm, P ϭ .0001) device groups. During load to failure testing, the vertical FasT-Fix group (125.3 Ϯ 39 N) had 28% greater strength than the horizontal FasT-Fix device group (89.7 Ϯ 14 N, P ϭ .02) and 30% greater strength than the RapidLoc device group (87.1 Ϯ 13 N, P ϭ .028), whereas displacement and stiffness did not show statistically significant group differences. Conclusions: The vertical FasT-Fix group had superior biomechanical characteristics for meniscal fixation during cyclic and load to failure testing compared with horizontal FasT-Fix or RapidLoc devices. Clinical Relevance: Although the RapidLoc devices provided fixation characteristics comparable to horizontally implanted FasT-Fix devices, vertically implanted FasT-Fix devices may provide superior all-inside fixation.

From a screening on agar plates with bis(benzoyloxyethyl) terephthalate (3PET), a Bacillus subtilis p-nitrobenzylesterase (BsEstB) was isolated and demonstrated to hydrolyze polyethyleneterephthalate (PET). PET-hydrolase active strains produced clearing zones and led to the release of the 3PET hydrolysis products terephthalic acid (TA), benzoic acid (BA), 2hydroxyethyl benzoate (HEB), and mono-(2-hydroxyethyl) terephthalate (MHET) in 3PET supplemented liquid cultures. The 3PET-hydrolase was isolated from non-denaturating polyacrylamide gels using fluorescein diacetate (FDA) and identified as BsEstB by LC-MS/MS analysis. BsEstB was expressed in Escherichia coli with C-terminally fused StrepTag II for purification. The tagged enzyme had a molecular mass of 55.2 kDa and a specific activity of 77 U/mg on pnitrophenyl acetate and 108 U/mg on p-nitrophenyl butyrate. BsEstB was most active at 40 C and pH 7.0 and stable for several days at pH 7.0 and 37 C while the half-life times decreased to 3 days at 40 C and only 6 h at 45 C. From 3PET, BsEstB released TA, MHET, and BA, but neither bis(2-hydroxyethyl) terephthalate (BHET) nor hydroxyethylbenzoate (HEB). The k cat values decreased with increasing complexity of the substrate from 6 and 8 (sÀ1) for p-nitrophenyl-acetate (4NPA) and p-nitrophenyl-butyrate (4NPB), respectively, to 0.14 (sÀ1) for bis(2-hydroxyethyl) terephthalate (BHET). The enzyme hydrolyzed PET films releasing TA and MHET with a concomitant decrease of the water-contact angle (WCA) from 68.2 AE 1.7 to 62.6 AE 1.1 due to formation of novel hydroxyl and carboxyl groups. These data correlated with a fluorescence emission intensity increase seen for the enzyme treated sample after derivatization with 2-(bromomethyl)naphthalene. V

Introduction Biodegradable implants are frequently used for meniscus repair. Articular cartilage damage has been reported recently after meniscus repair with biodegradable implants. The aim of the study was to investigate the meniscofemoral contact pressure at the posterior horn of the medial and lateral meniscus after repair of bucket-handle lacerations. Materials and methods Specimens were mounted in a materials testing machine (Bionix 858, MTS) which was equipped with a load cell. The quadriceps tendon was attached to a hydraulic cylinder, and knee motion was controlled via tension of the quadriceps tendon. A piezo-resistive system (Tekscan, Boston, MA, USA) measured the meniscofemoral contact pressure. Five different types of biodegradable implants (Arrow, Dart, Fastener, Stinger and Meniscal Screw) and horizontal suture (no. 2 Ethibond) were tested. The knee was extended from 90°of flexion to 0°under a constant load of 350 N due to adjustment of the tension force of the quadriceps tendon. The femorotibial pressure and contact area were recorded at 0°, 30°, 60°and 90°of flexion. Results The meniscofemoral pressure did not increase after meniscus repair with biodegradable implants or sutures. The meniscofemoral peak pressure at the posterior horn was 1.46±1.54 MPa in the medial compartment and 1.08±1.17 MPa in the lateral compartment at full knee extension. The meniscofemoral pressure increased significantly in both compartments with knee flexion from 0°to 90°. Conclusion Biodegradable implants for meniscus repair do not affect the meniscofemoral pressure. However, there remains a risk of damage to the cartilage when barbed implants are used. If the implant is not entirely advanced into the meniscus, the sharp head or some of the barbs at the column of the implant may come into direct contact with the articular cartilage of the femoral condyle or tibial plateau. The authors presume that incorrect positioning of the implant seems to be the major reason for cartilage damage.

The effect of high-pressure processing on 2 plastic food packaging films, a biopolymer (PLASiOx/PLA) and a synthetic polymer (PET-AlOx), was studied. Samples in direct contact with olive oil, as a fatty food simulant, and distilled water, as an aqueous simulant, were subjected to a pressure of 500MPa for 15 min at 50 • C. The mechanical, thermal, and gas barrier properties of both films were evaluated after the high-pressure processing (HPP) and compared to control samples that have not undergone this treatment. Significant changes in all properties were observed in both films after the HPP treatment and in contact with the food simulants. In both films an induced crystallization was noticed. In the PLASiOx/PLA film the changes were larger when in contact with water that probably acted as a plasticizer. In the PET-AlOx film the changes in properties were attributed to the formation of pinholes and cracks during the HPP treatment. In this film, most of the properties changed more in the presence of oil as the food simulant.

Yang et al suggest that the use of low-crystallinity poly(ethylene terephthalate) (PET) exaggerates our results. However, the primary focus of our study was identifying an organism capable of the biological degradation and assimilation of PET, regardless of its crystallinity. We provide additional PET depolymerization data that further support several other lines of data showing PET assimilation by growing cells of Ideonella sakaiensis.

Background. The present study was undertaken to evaluate clinical, hemodynamic, and morphologic results of composite stentless xenograft with polyethylene terephthalate fiber (Dacron; DuPont, Wilmington, DE) graft extension for combined replacement of the aortic valve, root, and ascending aorta.

h i g h l i g h t s " The role of waste PET was significant in the SMA and shows acceptable trends. " The mixtures containing waste PET have much higher rutting resistance. " The PET-mixtures have a higher resilient modulus. " Utilizing PET in the SMA mixture improve its resistance against binder drain down. " Utilizing PET in the SMA can have structural, environmental and economic benefits.

Heavy metal contaminants in environment, especially in drinking water, are always of great concern due to their health impact. Due to the use of heavy metals as catalysts during plastic syntheses, particularly antimony, human exposure to metal release from plastic bottles has been a serious concern in recent years. The aim and scope of this study were to assess metal contaminations leaching out from a series of recycling plastic bottles upon treatments. In this study, leaching concentrations of 16 metal elements were determined in 21 different types of plastic bottles from five commercial brands, which were made of recycling materials ranging from no. 1 to no. 7. Several sets of experiments were conducted to study the factors that could potentially affect the metal elements leaching from plastic bottles, which include cooling with frozen water, heating with boiling water, microwave, incubating with low-pH water, outdoor sunlight irradiation, and in-car storage. Heating and microwave can lead to a noticeable increase of antimony leaching relative to the controls in bottle samples A to G, and some even reached to a higher level than the maximum contamination level (MCL) of the US Environmental Protection Agency (USEPA) regulations. Incubation with low-pH water, outdoor sunlight irradiation, and in-car storage had no significant effect on antimony leaching relative to controls in bottle samples A to G, and the levels of antimony leaching detected were below 6 ppb which is the MCL of USEPA regulations. Cooling had almost no effect on antimony leaching based on our results. For the other interested 15 metal elements (Al, V, Cr, Mn, Co, Ni, Cu, As, Se, Mo, Ag, Cd, Ba, Tl, Pb), no significant leaching was detected or the level was far below the MCL of USEPA regulations in all bottle samples in this study. In addition, washing procedure did contribute to the antimony leaching concentration for polyethylene terephthalate (PET) bottles. The difference of antimony leaching concentration between washing procedure involved and no washing procedure involved (AC) was larger than zero for samples A to G. This interesting result showed that higher antimony concentration was detected in experiments with no washing procedures compared with those experiments with washing procedures. Our study results indicate that partial antimony leaching from PET bottles comes from contaminations on the surface of plastic during manufacturing process, while major antimony leaching comes from conditional changes. The results revealed that heating and microwaving enhance antimony leaching significantly in PET plastic bottles. Plastic bottle manufacturers should consider the contaminations during manufacturing process and washing bottles before first use was strongly recommended to remove those contaminants.

An attempt to substitute in concrete the 5% by weight of fine aggregate (natural sand) with an equal weight of PET aggregates manufactured from the waste un-washed PET bottles (WPET), is presented. The WPET particles possessed a granulometry similar to that of the substituted sand. Specimens with different cement content and water/cement ratio were manufactured. Rheological characterization on fresh concrete and mechanical tests at the ages of 28 and 365 days were performed on the WPET/concretes as well as on reference concretes containing only natural fine aggregate in order to investigate the influence of the substitution of WPET to the fine aggregate in concrete. It was found that the WPET concretes display similar workability characteristics, compressive strength and splitting tensile strength slightly lower that the reference concrete and a moderately higher ductility.

Background Use of the Rives-Stoppa procedure for ventral incisional hernia repair (RS-VIHR), in which the prosthesis is placed between the rectus abdominis muscle and the posterior sheath, has diminished reherniation markedly and is the most promising open technique. Materials and methods Over a 5-year period 176 open abdominal wall incisional hernia repairs were performed in our department by the Rives-Stoppa technique. The prosthetic material used was Mersilene and the mean follow-up time was 96 months (range: 62-121 months).

The goal of this work was to study the mechanical behavior of concrete with recycled Polyethylene Therephtalate (PET), varying the water/cement ratio (0.50 and 0.60), PET content (10 and 20 vol%) and the particle size. Also, the influence of the thermal degradation of PET in the concrete was studied, when the blends were exposed to different temperatures (200, 400, 600°C). Results indicate that PET-filled concrete, when volume proportion and particle size of PET increased, showed a decrease in compressive strength, splitting tensile strength, modulus of elasticity and ultrasonic pulse velocity; however, the water absorption increased. On the other hand, the flexural strength of concrete-PET when exposed to a heat source was strongly dependent on the temperature, water/cement ratio, as well as on the PET content and particle size. Moreover, the activation energy was affected by the temperature, PET particles location on the slabs and water/cement ratio.

Currently, polymer modified asphalt mixture is a relatively costly mixture for paving roads. One way to reduce the cost of such constructions and rendering them more convenient is by using inexpensive polymers, i.e. waste polymers. The main purpose of this research is to determine the effect of incorporating waste plastic bottles (Polyethylene Terephthalate (PET)) on the engineering properties of stone mastic asphalt (SMA) mixture. The volumetric and mechanical properties of asphalt mixes that include various percentages of PET (0%, 2%, 4%, 6%, 8% and 10%) were calculated and assessed with laboratory tests. The appropriate amount of PET was found to be 6% by weight of bitumen. The outcomes were statistically analysed and the determination of the significance at certain confidence limits was performed with the two factor variance analysis (ANOVA). Moreover, some studies conducted on polyethylene modified asphalt mixture have also been taken into consideration in this paper. The results show that the addition of PET has a significant positive effect on the properties of SMA and it can promote the re-use of waste material in industry in an environmentally friendly and economical way.► The PET increased the stiffness level of the mixture improving its resistance level against permanent deformation. ► The effects of waste PET on Marshall Stability, air void and bulk specific gravity of the mixture are significant. ► The appropriate amount of PET was found to be 6% by weight of bitumen.

The aim was to determine which contaminants were present in washed and dried shredded poly(ethylene terephthalate) (PET, flake) obtained from curbside collection and whether the concentrations were above the US FDA threshold of 215 ppb. Thirty-two semi-volatile contaminants were extracted from the treated flake by Soxhlet extraction using dichloromethane as a PET swelling solvent and gas chromatography-mass spectrometry (GC-MS) was used for identification and quantification. Soxhlet extraction of flake ground to 0-300 pm was effectively completed in 24 h, whereas sonication reduced the extraction time to 3 h. In contrast, Soxhlet extractions of flake ground to a larger particle size range (300-425 pm) were completed in 4 h, possibly due to less aggregation in the extraction thimble. The levels of 26 contaminants were below 215 ppb, but six were not. Dodecanoic acid was present at about 1200 ppb, 2-butoxyethanol was approximately 1000 ppb, limonene, benzophenone and methyl salicylate were above 800 ppb, and 2-methyl-naphthalene near 215 ppb.

In this work, the utilization of shredded waste Poly-ethylene Terephthalate (PET) bottle granules as a lightweight aggregate in mortar was investigated. Investigation was carried out on two groups of mortar samples, one made with only PET aggregates and, second made with PET and sand aggregates together. Additionally, blast-furnace slag was also used as the replacement of cement on mass basis at the replacement ratio of 50% to reduce the amount of cement used and provide savings. The water-binder (w/b) ratio and PET-binder (PET/b) ratio used in the mixtures were 0.45 and 0.50, respectively. The size of shredded PET granules used in the preparation of mortar mixtures were between 0 and 4 mm. The results of the laboratory study and testing carried out showed that mortar containing only PET aggregate, mortar containing PET and sand aggregate, and mortars modified with slag as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET granules as aggregate in the production of structural lightweight concrete. The use of shredded waste PET granules due to its low unit weight reduces the unit weight of concrete which results in a reduction in the death weight of a structural concrete member of a building. Reduction in the death weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependant on the dead-weight. Furthermore, it was also concluded that the use of industrial wastes such as PET granules and blast-furnace slag in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.

OBJECTIVES: Several techniques have been described for the treatment of thoraco-abdominal aneurysms in patients with mega-aortic syndrome (MAS), but the incidence of stroke, spinal cord injury and endoleaks remains significant. We present the mid-term results of a new hybrid, multistep technique to treat patients with MAS.

Poly(ethylene terephthalate) (PET) is used extensively worldwide in plastic products, and its accumulation in the environment has become a global concern. Because the ability to enzymatically degrade PET has been thought to be limited to a few fungal species, biodegradation is not yet a viable remediation or recycling strategy. By screening natural microbial communities exposed to PET in the environment, we isolated a novel bacterium, Ideonella sakaiensis 201-F6, that is able to use PET as its major energy and carbon source. When grown on PET, this strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid. Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol.

Whereas the nature of healing reaction in skeletal muscle following implantation of biomaterial has been extensively studied, the extent of variation in cell phenotypes is poorly known. Here, we studied the phenotypic alteration of cell types following injury in skeletal muscle of rabbits implanted with a commonly used biomaterial, polyethylene terephthalate (PET) fabric. Following implantation, histomorphological features were studied after 1, 4, and 12 weeks. Routine objective histomorphological evaluation was supplemented with histochemistry for collagen and immunohistochemistry for proliferating cell nuclear antigen (PCNA), CD34, vimentin, and alpha smooth muscle actin (a-SMA). The extent of reaction was quantified. The foreign body giant cells were found to comprise subpopulations, based on the variation in vimentin detectability or the presence of differentially capable proliferating nuclei (PCNA positive). Many rhabdomyocytes adjacent to the implant were PCNA-positive and some of them showed CD34 positivity. Often, the rhabdomyocytes very near to implanted PET fabric assumed a myofibroblast phenotype as evidenced by vimentin and/or a-SMA positivity at immunohistochemistry. Overall, the results suggested a phenotypic alteration of native cell types following implantation of PET fabric in rabbit skeletal muscle. Quantification of such cell types at the tissue-material interphase in relation to the deposition of collagen may be desirable during safety evaluation of biomaterials by histomorphology.

2 commercially bottled table water as a food simulant. Likewise compounds such as carbon disulfide, [1,1' biphenyl]-2-ol and propanoic acid, 2 methyl 1-(1,1 dimethyl)-2-methyl-1,3propanediyl ester probably originating from cotton and rubber components of netting materials may also contribute to off-odor/taste development.

Objective: The saphenous vein subjected to arterial pressure stretches to its elastic limits and constitutes intimal hyperplasia. Sheathing of the vein graft with pressure-resistant tubing might prolong vein graft patency. Methods: Twenty-one sheep received radial vein grafts or hybrid grafts composed of radial vein, collagen fibrin glue and highly flexible torlen/dacron mesh tubing transplanted into the carotid artery position. Veins were examined with the use of light and electron microscopy. Proliferating cell antigen (Ki-67) stains served as markers of proliferation. Results: The mean wall thickness of both intimal and medial layers was evaluated. The mean intimal wall thickness was 19^11 mm in hybrid grafts vs. 24^7 mm in unsheathed grafts (P , 0:001); 22^6 vs. 26^10 mm (P , 0:001); 23^8 vs. 52^15 mm (P , 0:001); 37^21 vs. 90^31 mm (P , 0:001); 57^31 vs. 104^28 mm (P , 0:001); 58^21 vs. 133^32 mm (P , 0:001); and 72^22 vs. 244^100 mm (P , 0:001) after respectively 5 days, 9 days, 4 weeks, 6 weeks, 8 weeks, 10 weeks and 12 weeks from implantation. Electronic microscope examination of hybrid grafts revealed a smooth endothelial layer with intact nuclei and an intima composed of layers of collagen and muscle fibers. In unsheathed grafts endothelial edema and nuclear destruction were observed. Conclusions: The external vein graft support with mesh tubing reduces intimal and medial layer thickening and cell proliferation in composite vein grafts transplanted in the arterial position.

Currently, polymer modified asphalt mixture is a relatively costly mixture for paving roads. One way to reduce the cost of such constructions and rendering them more convenient is by using inexpensive polymers, i.e. waste polymers. The main purpose of this research is to determine the effect of incorporating waste plastic bottles (Polyethylene Terephthalate (PET)) on the engineering properties of stone mastic asphalt (SMA) mixture. The volumetric and mechanical properties of asphalt mixes that include various percentages of PET (0%, 2%, 4%, 6%, 8% and 10%) were calculated and assessed with laboratory tests. The appropriate amount of PET was found to be 6% by weight of bitumen. The outcomes were statistically analysed and the determination of the significance at certain confidence limits was performed with the two factor variance analysis (ANOVA). Moreover, some studies conducted on polyethylene modified asphalt mixture have also been taken into consideration in this paper. The results show that the addition of PET has a significant positive effect on the properties of SMA and it can promote the re-use of waste material in industry in an environmentally friendly and economical way. © 2011 Elsevier Ltd.

http://www.sciencedirect.com/science/article/pii/S0261306911004225

In order to improve the properties of asphalt mixture and reduce the negative impact of the waste materials on nature and the environment, it seems to be logical to propose a means of re-using waste materials in engineering and industrial construction projects such as road pavement. The current paper presents an experimental research on the application of waste plastic bottles (Polyethylene Terephthalate (PET)) as an additive in stone mastic asphalt (SMA). Wheel tracking, moisture susceptibility, resilient modulus and drain down tests were carried out on the mixtures that included various percentages of waste PET as 0%, 2%, 4%, 6%, 8% and 10% by weight of bitumen content. By experimentation, the appropriate range for the amount of waste PET was determined to be 4-6% by weight of the bitumen content. The results show that the addition of waste PET into the mixture has a significant positive effect on the properties of SMA which could improve the mixture's resistance against permanent deformation (rutting), increase the stiffness of the mix, provide lower binder drain down and promotion of re-use and recycling of waste materials in a more environmentally and economical way. © 2012 Elsevier Ltd. All rights reserved.

http://www.sciencedirect.com/science/article/pii/S0950061812004072

One of the major types of plastics that can be found in Municipal Solid Waste (MSW) is Polyethylene Terephthalate (PET) which is a non-biodegradable semi-crystalline thermoplastic polymer, and is considered as polyester material. Generating large amount of waste PET, mainly as bottles, would cause environmental hazards by disposing in landfills. This paper aims to evaluate effects of utilizing waste PET flakes as modifier in asphalt mixture as an alternative solution to overcome the potential risks arise from producing large amount of waste PET as well as evaluating the deformation characteristics of unmodified and PET modified asphalt mixtures. To achieve this aim, different percentages of PET were designated for this investigation, namely: 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1% by weight of aggregate particles, and dynamic creep test was performed at different stress levels (300 kPa and 400 kPa) and temperatures (10°C, 25°C and 40°C). Consequently, Zhou three-stage model was developed. The results showed that permanent deformation characteristics of asphalt mixture were considerably improved by utilization of PET modification, when the permanent strain was remarkably decreased in PET modified mixture compared to the conventional mixture at all stress levels and temperatures. Besides, based on Zhou model, it was concluded that elastic and visco-elastic properties of asphalt mixture were improved by application of PET modification.

Background. The surgical reconstruction of right ventricle outflow tract (RVOT) often requires the implantation of a valved conduit. Homografts are lacking availability and are associated with limited durability in children. Our experience with the Hancock porcinevalved Dacron (DuPont, Wilmington, DE) conduit (Medtronic, Minneapolis, MN) was retrospectively assessed.

In the repair of soft tissue to bone using suture anchors, failure of the suture material can occur at the anchor eyelet. This study examines the load strength at which suture material fails with different metallic suture anchor eyelets. Biomechanical study. Suture material (Ethibond No. 2, Ethicon, Norderstedt, Germany) was pulled out from 22 metallic suture anchor models at 60 mm/min, and tensile load at failure and failure mode were recorded. Tests were performed either by simultaneous pulling on 2 suture limbs in 3 different directions (straight, at 45 degrees, and at 45 degrees rotated by 90 degrees to the suture anchor axis) or by pulling on 1 suture limb while measuring the resulting force on the second limb. All tests were performed until suture failure. Pulling was performed in single tests on an Instron materials testing machine (High Wycombe, UK), with the anchors held by a vise. In all cases, the suture failed at the anchor eyelet. Failure load at straight loading ranged from 116 +/- 5 N to 226 +/- 5 N and from 69 +/- 5 N to 193 +/- 7 N when loaded at an angle of 45 degrees. The best results were found with the Statak 5.2-mm (Zimmer, Warsaw, IN): 177 N; Corkscrew 6.5-mm anchor (Arthrex, Naples, FL): 174 N; and PeBA 4.0-mm anchor (OBL Orthopaedic Biosystems, Scottsdale, AZ): 169 N. With each eyelet, sutures failed preferentially in 1 direction, depending on the presence of sharp edges. Suture material can be cut at suture anchor eyelets. Failure load depends on sharp edges on the eyelet and occurs at forces up to 73% below the breaking strength of the suture material on a smooth hook. Anchors with suture-protecting channels are particularly sensitive to the orientation in which the sutures are loaded.

Polyethylene terephthalate (PET) waste flakes were degraded with aqueous methylamine and aqueous ammonia, respectively at room temperature in the presence and absence of quaternary ammonium salt as a catalyst for different periods of time. The aminolysed and ammonolysed PET samples were investigated for the surface morphology with the help of scanning electron micrograph (SEM). It shows that the semi-crystalline PET waste samples reduce to monodisperse rods before fully degradation to the end products. The presence of the catalyst provides site for degradation of PET waste and enhances the rate of degradation. The SEM shows early developments of fissures in comparison to the one in absence of quaternary ammonium salt used as catalyst.

Goals of work Aprepitant is currently recommended for the prevention of acute antineoplastic-induced nausea and vomiting in adults receiving highly emetogenic therapy. The lack of an oral liquid dosage form is one barrier to its use in children. The purpose of this study was to develop a stable oral liquid formulation of aprepitant using the marketed aprepitant capsules. Materials and methods Aprepitant 20-mg/mL oral liquid was prepared from 125-mg capsule contents in Orablend®. Twelve test samples were prepared: six packaged in amber glass and six in polyethylene terephthalate (PET) containers, three of each stored at either 23°C or 4°C. The physical characteristics of the oral aprepitant liquid stored in amber glass bottles were evaluated at the time of compounding and on days 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, and 91. The aprepitant content of three test solutions of each container type and storage temperature was deter-mined using a stability-indicating assay at 14, 29, 48, 62, 73, and 111 days after compounding. Main results All samples stored in glass demonstrated suitable physical characteristics and those stored in either glass or PET retained more than 94.0% of the initial concentration. Based on the higher limit of the 95% confidence interval of the degradation rate, suspensions stored at 23°C achieved 10% loss within 66 to 85 days, compared to greater than 100 days when stored at 4°C. Conclusions The extemporaneous aprepitant oral suspension formulation described is physically and chemically stable for at least 90 days when refrigerated. The bioavailability of this formulation is unknown.

Right coronary arteries that arise from the left sinus or ectopically from the right sinus with a slit ostium can cause myocardial ischemia, myocardial infarction, or sudden death. The surgical repair of these anomalies has evolved toward a simpler operation that widens the R ight coronary arteries that arise from the left sinus in an anomalous manner have been classified by Kragel and Roberts [1] into four types. These types are defined in and are depicted in . In addition, Virmani [2,3] and Isner and their associates have observed that right coronary arteries which arise ectopically in the right sinus behave in the same manner as those that arise anomalously from the left sinus when the ostium has a valve ridge (ie, slit). Both groups of anomalies produce myocardial ischemia and infarction, and their sequelae .

Materials and methods. Graft infections were established in the back subcutaneous tissue of 120 adult male Wistar rats by implantation of 1-cm 2 Dacron/ ePTFE prosthesis followed by topical inoculation with 2 ؋ 10 7 CFU of clinical isolate of MRSE. Each of the series included one group with no graft contamination and no antibiotic prophylaxis (uncontaminated control), one contaminated group that did not receive any antibiotic prophylaxis (untreated control), one contaminated group in which perioperative intraperitoneal prophylaxis with vancomycin (10 mg/kg) was administered, two contaminated groups that received rifampicin-soaked (5 mg/1 ml) or vancomycin-soaked (1 mg/1 ml) grafts, and one contaminated group that received a combination of rifampicin-soaked (5 mg/1 ml) graft with perioperative intraperitoneal vancomycin prophylaxis (10 mg/kg). The grafts were removed sterilely 7 days after implantation and evaluated by using sonication and quantitative blood agar culture.

Purpose Swanson's technique for repair of the extensor tendon of the proximal interphalangeal (PIP) joint, entailing bony reattachment of the extensor tendon to the base of the middle phalanx, is a common procedure. We introduce a repair technique that is less complicated and that may be equally appropriate for approach to the PIP joint. The extensor tendon is incised longitudinally directly over the PIP joint. The insertion of the central slip and capsule are elevated off of the base of the middle phalanx. This allows excellent visualization of the PIP joint. The extensor tendon is then repaired by side-to-side approximation using Ethibond suture. The purpose of this study was to test and compare the strength of this proposed technique with that of Swanson in a cadaver model.

A lipase from Thermomyces lanuginosus and cutinases from Thermobifida fusca and Fusarium solani hydrolysed poly(ethylene terephthalate) (PET) fabrics and films and bis(benzoyloxyethyl) terephthalate (3PET) endo-wise as shown by MALDI-Tof-MS, LC-UVD/MS, cationic dyeing and XPS analysis. Due to interfacial activation of the lipase in the presence of Triton X-100, a seven-fold increase of hydrolysis products released from 3PET was measured. In the presence of the plasticizer N,N-diethyl-2-phenylacetamide (DEPA), increased hydrolysis rates of semi-crystalline PET films and fabrics were measured both for lipase and cutinase. The formation of novel polar groups resulted in enhanced dye ability with additional increase in colour depth by 130% and 300% for cutinase and lipase, respectively, in the presence of plasticizer.

This study monitored the release of mutagenicycarcinogenic compounds into mineral water (natural and carbonated) from polyethylene terephthalate (PET) bottles, using a plant mutagenicity test which reveals micronuclei formation in Tradescantia pollen cells (TradyMCN test), a DNA damage assay (Comet assay) on human leukocytes and gas chromatographyymass spectrometry (GCyMS) for the characterisation of migrants. The water samples were collected at a bottling plant and stored in PET bottles for a period ranging from 1 to 12 months. Every month some samples were randomly collected and lyophilised, the residual powders were extracted with organic solvents and then analysed by GCyMS and tested for DNA damage in human leukocytes, or reconstituted with distilled water to obtain concentrates for the exposure of Tradescantia inflorescences. Micronuclei increase in pollen was found only in natural mineral water stored for 2 months. DNA-damaging activity was found in many of the natural and carbonated water samples. Spring water was negative in the plant micronuclei test and the Comet assay, whereas distributed spring water showed DNA-damaging effects, suggesting a possible introduction of genotoxins through the distribution pipelines. GCyMS analysis showed the presence in mineral water of di(2-ethylhexyl)phthalate, a nongenotoxic hepatocarcinogenic plasticizer, after 9 months of storage in PET bottles. ᮊ

Human adult bone marrow contains hematopoietic lineage cells as well as a heterogeneous population of cells making up the marrow stroma . Stromal cells include adipocytes, reticular cells, endothelial cells, and fibroblastic cells. They are in direct contact with hematopoietic cells and support the differentiation of Background: It has been frequently reported that culture-expanded mesenchymal stem cells from bone marrow of healthy donors can be induced to differentiate to osteocytic lineage. This study examined the potential for osteogenic differentiation of mesenchymal stem cells obtained from two patients with myeloproliferative disorders. Methods: Mesenchymal stem cells were derived from bone marrow aspirates obtained in an outpatient clinic from two patients, one with polycythemia vera and the other with essential thrombocythemia. Nucleated bone marrow cells were directly cultured in flasks. Adherent fibroblastic cells in monolayers were isolated by removing nonadherent cells during medium changes. Osteogenic differentiation was induced in expanded adherent cells for 2 weeks in osteogenic medium containing 100 nmol/ L dexamethasone, 10 mmol/L β-glycerophosphate, and 0.05 mmol/L L-ascorbic acid-2-phosphate. Osteogenic differentiation was evaluated by alkaline phosphatase staining and determination of calcium in deposited minerals on culture plates. The expression of osteopontin mRNA was determined by reverse transcription-polymerase chain reaction. Results: After induction in osteogenic medium, the expression of alkaline phosphatase in mesenchymal stem cells became more intense. Induced alkaline phosphatase-positive cells assumed an irregular shape with multiple spiculate projections, while uninduced alkaline phosphatase-positive cells had a flattened polygonal shape or were elongated. Calcium deposition on the plates of induced cells was 0.39 ± 0.03 µmol/well in cells from the patient with polycythemia vera and 0.54 ± 0.03 µmol/ well in cells from the patient with essential thrombocythemia, but was not detectable in uninduced cells from either patient. Induction by osteogenic medium markedly increased the expression of osteopontin mRNA in stem cells derived from both patients. Conclusions: In this study, mesenchymal stem cells obtained from aspiration of bone marrow in patients with myeloproliferative disorders were expanded by culture. After osteogenic induction, these cells were shown to be able to differentiate into osteocytic lineage in vitro.

Oligomers and polymers (film, fabrics) of the linear aromatic polyester poly(trimethylene terephthalate) (PTT) were treated with polyesterases from Thermomyces lanuginosus, Penicillium citrinum, Thermobifida fusca and Fusarium solani pisi. The cutinase from T. fusca was found to release the highest amounts of hydrolysis products from PTT materials and was able to open and hydrolyse a cyclic PTT dimer according to RP-HPLC-UV detection. In contrast, the lipase from T. lanuginosus also showed activity on the PTT fibres and on bis(3-hydroxypropyl) terephthalate (BHPT) but was not able to hydrolyse the polymer film, mono(3-hydroxypropyl) terephthalate (MHPT) nor the cyclic dimer of PTT. As control enzymes inhibited with mercury chloride were used. Surface hydrophilicity changes were investigated with contact angle measurements and the degree of crystallinity changes were determined with DSC.

Poly(ethylene terephthalate) (PET) fiber analysis and comparison by spectral and polymer molecular weight determination was investigated. Plain fibers of PET, a common textile fiber and plastic material was chosen for this study. The fibers were analyzed for morphological (SEM and AFM), spectral (IR and NMR), thermal (DSC) and molecular weight (MS and GPC) differences. Molecular analysis of PET fibers by Gel Permeation Chromatography (GPC) allowed the comparison of fibers that could not be otherwise distinguished with high confidence. Plain PET fibers were dissolved in hexafluoroisopropanol (HFIP) and analyzed by GPC using hexafluoroisopropanol:chloroform 2:98 v/v as eluent. 14 PET fiber samples, collected from various commercial producers, were analyzed for polymer molecular weight by GPC. Distinct differences in the molecular weight of the different fiber samples were found which may have potential use in forensic fiber comparison. PET fibers with average molecular weights between about 20,000 and 70,000 g mol À 1 were determined using fiber concentrations in HFIP as low as 1 μg mL À 1 . This GPC analytical method can be applied for exclusively distinguish between PET fibers using 1 μg of fiber. This method can be extended to forensic comparison of other synthetic fibers such as polyamides and acrylics.

Moreno, M. J.; Ajji, A.; Mohebbi-Kalhori, D.; Rukhlova, M.; Hadjizadeh, A.; Bureau, M. N. Contact us / Contactez nous: nparc.cisti@nrc-cnrc.gc.ca. http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=fr L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le site Web page / page Web http://dx.

The diagnosis and treatment of SLAP tears have improved with the development of arthroscopic shoulder surgery techniques. With types 2 and 4 tears, the goal is to restore stability to the labrum and biceps anchor and achieve healing to the glenoid. Suture repair with anchors is currently the repair technique of choice. The purpose of this article is to report a fast and simple method for arthroscopic SLAP repair that uses knotless suture anchors and obviates complex suture management and arthroscopic knot tying.