Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning–electrospraying hybrid process for use in protective applications

ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications

The design and testing of a dual fiber textile matrix for accelerating surface hemostasis

The standard treatment for severe traumatic injury is frequently compression and application of gauze dressing to the site of hemorrhage. However, while able to rapidly absorb pools of shed blood, gauze fails to provide strong surface (topical) hemostasis. The result can be excess hemorrhage-related morbidity and mortality. We hypothesized that cost-effective materials (based on widespread availability of bulk fibers for other commercial uses) could be designed based on fundamental hemostatic principles to partially emulate the wicking properties of gauze while concurrently stimulating superior hemostasis. A panel of readily available textile fibers was screened for the ability to activate platelets and the intrinsic coagulation cascade in vitro. Type E continuous filament glass and a specialty rayon fiber were identified from the material panel as accelerators of hemostatic reactions and were custom woven to produce a dual fiber textile bandage. The glass component strongly activated platelets while the specialty rayon agglutinated red blood cells. In comparison with gauze in vitro, the dual fiber textile significantly enhanced the rate of thrombin generation, clot generation as measured by thromboelastography, adhesive protein adsorption and cellular attachment and activation. These results indicate that hemostatic textiles can be designed that mimic gauze in form but surpass gauze in ability to accelerate hemostatic reactions

Safety evaluation in the development of medical devices and combination products

Capturing the growth of the global medical device market in recent years, this practical new guide is essential for all who are responsible for ensuring safety in the use and manufacture of medical devices. It has been extensively updated to reflect significant advances, incorporating combination products and helpful case examples of current real-life problems in the field.The Third Edition explores these key current trends:global device marketscontinually advancing technologythe increasing harmonization of device safety regulation worldwideEach aspect of safety evaluation is considered in te

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Single serum progesterone as a screen for ectopic pregnancy: exchanging specificity and sensitivity to obtain optimal test performance

To investigate the diagnostic accuracy of screening serum P in diagnosis of ectopic pregnancy (EP) and to identify a cutoff value that provides the best compromise between test sensitivity and specificity. Retrospective analysis. University hospital. Observation only. First trimester pregnant women at risk for EP. Single P measurements were obtained from 3,674 pregnancies with outcomes defined as EP, viable intrauterine pregnancy (IUP), and spontaneous abortion (SAB). Diagnostic accuracy of the test was analyzed by generating receiver operating characteristic (ROC) curves, which quantify the ability of the test to distinguish EP and SAB from IUP. Diagnostic accuracy for EP versus IUP was 88.7%±0.1% (mean±SEM); for SAB versus IUP, 93.8±0.4%; and for SAB±EP versus IUP, 92.8%±0.4%. Diagnostic accuracy for SAB versus EP was only 39.4%±0.2%. In the interval of 15.0 to 19.9ng/mL (47.7 to 63.3nmol/L), P missed 5.3% of the EPs and incorrectly included 84.3% of the viable IUPs; in the interval of 20.0 to 24.9ng/mL (63.6 to 79.2nmol/L), sensitivity improved in that only 3.5% of the EPs were missed but 88.8% of viable IUPs were included incorrectly. A cutoff value of≥17.5ng/mL (55.7nmol/L), the median point of the 15.0 to 19.9ng/mL (47.7 to 63.3nmol/L) interval, missed only 35 of 423 (8.3%) total EPs in the study. Analysis of ROC curves demonstrates that single serum P has high diagnostic accuracy for differentiating accidents of pregnancy (SAB and EP) from viable IUP, both individually (SAB versus IUP and EP versus IUP) and collectively (SAB+EP versus IUP); it cannot efficiently discriminate SAB versus EP. We conclude that for P≥17.5ng/mL (55.7nmol/L), patients thought to be at risk for EP may be followed reasonably without ultrasound or further invasive diagnostic studies

Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning–electrospraying hybrid process for use in protective applications

ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications

Novel 3-D Spacer Textiles to Protect Crops from Insect Infestation and That Enhance Plant Growth

Pesticide-free, 3-D, spacer fabrics (Plant Armor Generation (PA Gen) 1 and 2) were investigated for proof-of-concept as an insect barrier to protect plants and improve plant agronomics for organic farming. The time to 50% penetration (TP50) for tobacco thrips, Frankliniella fusca (Hinds) adults in laboratory Petri dish bioassays was 30 and 175 min for PA Gen 1 and 2, respectively, and 12 min for the control (a commercially available, single layer-crop cover, Proteknet). PA Gen 2 was ≥90% resistant to penetration of unfed caterpillar neonates, Helicoverpa zea (Boddie), while the TP50‘s for Gen 1 and Proteknet were 3.1 and 2.35 h, respectively. In small cage studies, PA Gen 2 covered potted cabbage plants were 100% resistant to penetration by these insects through 10 d after which the study was ended. In small field plot studies for 3 summer months, cabbage plants grew approximately twice as fast when covered versus not covered with Gen 1 and Gen 2 without the need for insecticides or herbicides. This was not observed for the control crop cover. Martindale abrasion tests demonstrated Gen 1 and 2 were at least 6- and 1.8-fold more durable than the control crop cover used. Data are also presented on percentage light, water, air, and water vapor penetration across each textile and operational temperatures and humidity for cabbage plants covered and uncovered in small field plots

Copper-Encapsulated Vertically Aligned Carbon Nanotube Arrays

A new procedure is described for the fabrication of vertically aligned carbon nanotubes (VACNTs) that are decorated, and even completely encapsulated, by a dense network of copper nanoparticles. The process involves the conformal deposition of pyrolytic carbon (Py-C) to stabilize the aligned carbon-nanotube structure during processing. The stabilized arrays are mildly functionalized using oxygen plasma treatment to improve wettability, and they are then infiltrated with an aqueous, supersaturated Cu salt solution. Once dried, the salt forms a stabilizing crystal network throughout the array. After calcination and H₂ reduction, Cu nanoparticles are left decorating the CNT surfaces. Studies were carried out to determine the optimal processing parameters to maximize Cu content in the composite. These included the duration of Py-C deposition and system process pressure as well as the implementation of subsequent and multiple Cu salt solution infiltrations. The optimized procedure yielded a nanoscale hybrid material where the anisotropic alignment from the VACNT array was preserved, and the mass of the stabilized arrays was increased by over 24-fold because of the addition of Cu. The procedure has been adapted for other Cu salts and can also be used for other metal salts altogether, including Ni, Co, Fe, and Ag. The resulting composite is ideally suited for application in thermal management devices because of its low density, mechanical integrity, and potentially high thermal conductivity. Additionally, further processing of the material via pressing and sintering can yield consolidated, dense bulk composites