EVA System Research Articles

Regulating reaction kinetics used for the preparation of ethylene-vinyl acetate copolymer with high grafting ratio

A feasible and innovative reaction kinetics control method was proposed to reduce the degradation, cross-linking and other side reactions during the melt grafting process. The components in the melt grafting system were firstly blended at a temperature lower than the half-life (170 °C) of the radical initiator. After the system was homogeneous, the temperature was raised to the half-life temperature for high-temperature melting reaction. By regulating the reaction kinetics of silane grafted EVA system, the collision probability between macromolecular free radicals and grafted monomers was effectively increased. The efficiency and grafting rate of EVA grafted by silane were significantly improved, which reached a maximum of 74.45 % and 4.81 wt%, respectively. The thermal behavior, crystallographic, mechanical and electrical properties of the grafts were further characterized, which made the structure-activity relationship of polymers construct and investigate.

EVA NEXUS-Phaco performance study.

To investigate a novel phacoemulsification system "EVA NEXUS" (D.O.R.C., Dutch Opthalmic Research Center) in comparison to the existing system "EVA" in clinical use. And to compare both phacoemulsification systems in terms of efficiency, safety and postoperative inflammatory activity. In this study standardized cataract surgery was performed on both eyes of the study participant, using the "EVA system" (control group, n=20) on one eye and the "EVA NEXUS system" (intervention group, n=20) on the other eye. Only patients with cataract LOCS Grading 1-3 and no accompanying eye diseases were included in this study. A total of 20 patients were included in this study, with each treatment arm including 20 eyes. During surgery a 0.1 mL aqueous humor sample was collected 1min after phacoemulsification to measure the total prostaglanin E2 concentrations using an enzyme-linked immunosorbent assay. The endothelial cell count, visual and refractive outcomes, and anterior chamber flare were evaluated preoperatively, and 1d, 1wk, and 3mo postoperatively. There were no statistically significant differences between both groups regarding intraoperative safety parameters including effective phacoemulsification time (P=0.904), balanced saline solution flow (P=0.701) and total surgery time (P=0.565). Postoperative prostaglandin E2 levels, anterior chamber flare as well as endothelial cell loss tended to be lower in the NEXUS-Group, however not being statistically significant (P=0.718; 0.164; 0.486). Both systems provided similar clinical outcomes, regarding best corrected visual acuity and refractive parameters, showing no statistically significant differences between both groups. Both systems show a high level of safety and efficency with similar results in terms of safety parameters including postoperative inflammatory activity and endothelial cell loss as well as visual and refractive outcomes. Although statistically not significant, the EVA NEXUS system tends to cause less postoperative inflammation with lower prostaglandin E2 levels and lower anterior chamber flare values.

Diagnostic Efficacy of Enhanced Visual Assessment [Visual Check] for Triaging Cervical Cancer Screen Positive Women.

Colposcopy is important for triaging any abnormal cervical screening test. Scarcity of trained colposcopists and colposcopy centers is a big hurdle to screening programs in low- and middle-income countries. The objective was to assess the performance of the artificial intelligence incorporated into the mobile optical device technologies (ODT) Enhanced Visual Assessment (EVA visual check) against physician colposcopic diagnosis and the gold standard of histopathology. It was a cross-sectional observational study conducted on women referred to a colposcopy clinic following an abnormal screening test. Colposcopic examination was performed by colposcopists using the MobileODT EVA system. Physician's impression and Visual Check analysis were compared with the final histopathological analysis or cytology. Cases with normal cytology and normal colposcopy did not undergo biopsy, and these were considered normal. A total of 2050 women were screened, and 147 screen-positive women were recruited in the study. EVA Visual Check had a sensitivity of 86.8% (75-95), specificity of 28.7% (20-39), positive predictive value (PPV) of 40.7% (32-50), negative predictive value (NPV) of 79.4% (62-91), and diagnostic accuracy of 49.7% (41-58) for diagnosing cervical intraepithelial neoplasia (CIN) 1+ lesions. EVA Visual Check has a sensitivity of 89.3% (72-98), specificity of 26.1% (18-35), PPV of 22.1% (15-31), NPV of 91.2% (76-98), and diagnostic accuracy of 38.1% (30-46) for CIN 2+ lesions. MobileODT EVA colposcope with AI has sensitivity comparable to physician's diagnosis, whereas specificity, PPV, and NPV were less than that of physician's diagnosis. It could prove valuable for triage of screen-positive women for further management.

Correlation of the mobile colposcopy eva system with ai algorythm visualcheck2.0 and mobilab hpv 16/18/31 antigen rapid test in daily gynecological practice

Correlation of the mobile colposcopy eva system with ai algorythm visualcheck2.0 and mobilab hpv 16/18/31 antigen rapid test in daily gynecological practice

Mobile colposcopy by trained nurses in a cervical cancer screening programme at Battor, Ghana.

Cervical precancer screening programs are difficult to establish in low resource settings partly because of a lack of human resource. Our aiming was to overcome this challenge. We hypothesized that this could be done through task shifting to trained nurses. Descriptive retrospective cross-sectional review. Training was at the Cervical Cancer Prevention and Training Center (CCPTC) and screening was carried out at the clinic and at outreaches / peripheral facilities. All women who reported to the clinic for screening or were recruited during outreaches. All 4 nurses were trained for at least 2weeks (module 1). A total of 904 women were screened by the trained nurses using the EVA system. Quality assurance was ensured. Primary screening and follow-up were carried out by the trained nurses with quality assured through image sharing and meetings with peers and experienced gynaecologists. 828 women had primary screening and 76 had follow-up screening. 739 (89.3%) were screened at the clinic and 89 (10.7%) at outreaches/peripheral facilities. Of all screened, 130 (14.5%) had cervical lesions, and 25 (2.8%) were treated, 12 (48.0%) by Loop Electrosurgical Excision Procedure (LEEP) performed by a gynaecologist, 11 (44.0%) with thermal coagulation by trained nurses except one, and 2 (8.0%) with cryotherapy by trained nurses. We demonstrate the utility of a model where nurses trained in basic colposcopy can be used to successfully implement a cervical precancer screening and treatment program in low-resource settings. None indicated.

EVA: Fully automatic hemodynamics assessment system for the bulbar conjunctival microvascular network

Background and objectiveConjunctival microcirculation has been used to quantitatively assess microvascular changes due to systemic disorders. The space between red blood cell clusters in conjunctival microvessels is essential for assessing hemodynamics. However, it causes discontinuities in vessel image segmentation and increases the difficulty of automatically measuring blood velocity. In this study, we developed an EVA system based on deep learning to maintain vessel segmentation continuity and automatically measure blood velocity. MethodsThe EVA system sequentially performs image registration, vessel segmentation, diameter measurement, and blood velocity measurement on conjunctival images. A U-Net model optimized with a connectivity-preserving loss function was used to solve the problem of discontinuities in vessel segmentation. Then, an automatic measurement algorithm based on line segment detection was proposed to obtain accurate blood velocity. Finally, the EVA system assessed hemodynamic parameters based on the measured blood velocity in each vessel segment. ResultsThe EVA system was validated for 23 videos of conjunctival microcirculation captured using functional slit-lamp microscopy. The U-Net model produced the longest average vessel segment length, 158.03 ± 181.87 µm, followed by the adaptive threshold method and Frangi filtering, which produced lengths of 120.05 ± 151.47 µm and 99.94 ± 138.12 µm, respectively. The proposed method and one based on cross-correlation were validated to measure blood velocity for a dataset consisting of 30 vessel segments. Bland-Altman analysis showed that compared with the cross-correlation method (bias: 0.36, SD: 0.32), the results of the proposed method were more consistent with a manual measurement-based gold standard (bias: -0.04, SD: 0.14). ConclusionsThe proposed EVA system provides an automatic and reliable solution for quantitative assessment of hemodynamics in conjunctival microvascular images, and potentially can be applied to hypoglossal microcirculation images.

Life Sciences Discovery and Technology Highlights

Life Sciences Discovery and Technology Highlights

A pilot study of mobile digital colposcopy in Japanese patients with cervical intraepithelial neoplasm.

Digital colposcopy built around a smartphone is becoming common, and this has advantages for telemedicine and data sharing by taking advantage of smartphone characteristics. However, digital colposcopy itself is not allowed in clinical practice in Japan. The aim of the present study was to investigate the feasibility of mobile digital colposcopy incorporating a smartphone for management of cervical screening in Japanese patients. Patients who underwent colposcopy at Saitama Medical University International Medical Center between July 2019 and February 2020 were enrolled in the present study. The inclusion criteria were women aged 21-65 years old referred for colposcopy following the Japanese standard of care. Written informed consent was obtained from all patients. A total of 40 patients (52 tests) were included in the study. Following the standard of care, acetic acid was applied to the cervix, which was then visualized using a traditional colposcope, with biopsies collected as necessary. The cervix was then visualized and an imaged was captured using a mobile digital colposcope incorporating a smartphone (EVA System; Mobile ODT). All images were collected before biopsy. Images were stored on a secure cloud portal for subsequent evaluation by the provider who performed the conventional colposcopy, and the diagnoses were compared. The present study was approved by the Institutional Review Board of Saitama Medical University International Medical Center (Hidaka, Japan). The match rates for diagnoses were 75%. The match rates for the actual (from conventional colposcopy) and assumed (from digital colposcopy) biopsy sites were 61, 16 and 23%, based on definitions of the ‘same’, ‘almost the same’ and ‘different’, respectively. The present results indicated that ≥75% cases were equivalent in digital colposcopy and conventional colposcopy. This suggests that digital colposcopy may not be inferior to conventional colposcopy.

Effect of Different Methods for the Overhang Amalgam Restorations Removal on Periodontal Health Status

Overhanging tooth restorations due to environmental change of the balance between beneficial bacteria and periodontopathogens lead to periodontal breakdown. This study aim was to evaluate the periodontal status after using different techniques for amalgam overhang removal. The proximal restorations were examined clinically and then radiographically by taking bitewing radiograph. From a total of 1200 patients examined in College of Dentistry, Hawler Medical University and (Khanzad) Specialized Centre for Dentistry for presence of proximal amalgam restoration, for this interventional and prospective study, 45 patients with amalgam overhang were divided into three groups each 15 patients according to size and position of amalgam overhang each had one type of the following treatment (Refilling, Diamond Bur, EVA system) and 15 patients without amalgam overhang (control group) selected completed the trial. Clinical periodontal parameters were measured in teeth with amalgam overhang at baseline, 2 week, 1 and 3 months after removal of amalgam overhang. The results showed that the periodontal parameters showed a gradual decrease in all groups throughout the follow-up visits (except calculus index) and became a statistically significant in the 3 months follow-up following treatment (P < 0.001), with more reduction found in refilling group followed by EVA system then diamond bur group. In conclusion that it is better to replace the restoration rather than to use the other methods of treatment according to periodontal health which recorded by periodontal parameters.

Improving fire retardancy of ceramifiable polyolefin system via a hybrid of zinc borate@melamine cyanurate

To achieve a high flame retardancy of ethylene-vinyl acetate copolymer (EVA)-based ceramifiable composites, we prepared a hybrid of zinc borate@melamine cyanurate (ZB@MCA) by depositing zinc borate (ZB) at the surface of melamine cyanurate (MCA) on the basis of their hydrogen bonding, and incorporated the ZB@MCA into the EVA/glass powder/mica powder/organo-modified montmorillonite (EVA/GP/MP/OMMT) system to form a novel flame-retardant and ceramifiable EVA composite (EVA/GP/MP/OMMT/ZB@MCA). For EVA/GP/MP/OMMT/ZB@MCA composite with a weight ratio of 35/23/17/5/20, its ceramic formed at 800 °C has the flexural strength of 13.9 MPa, keeping at a high level. The burning tests confirmed that the limiting oxygen index (LOI) value of the composite reached 27.5%, and the UL-94 V-0 rating was achieved. The peak of heat release rate (PHRR) and the peak of smoke production rate (SPR) decreased remarkably compared with the corresponding value of neat EVA in cone calorimeter test. Thermogravimeter-Fourier transform infrared spectroscopy (TG-FTIR) and X-ray photoelectron spectroscopy (XPS) spectra were used to illustrate the flame-retardant mechanism of ZB@MCA in ceramifiable EVA system, and the result illustrated that the gas-phase flame-retardant mechanism was dominant, meanwhile, the ZB facilitated the formation of ceramic layer as a physical barrier in condensed phase, further leading to the enhancement of flame retardancy of EVA composite.

Assessment and economic valuation of air pollution impacts on human health over Europe and the United States as calculated by a multi-model ensemble in the framework of AQMEII3.

The impact of air pollution on human health and the associated external costs in Europe and the United States (US) for the year 2010 are modeled by a multi-model ensemble of regional models in the frame of the third phase of the Air Quality Modelling Evaluation International Initiative (AQMEII3). The modeled surface concentrations of O3, CO, SO2 and PM2.5 are used as input to the Economic Valuation of Air Pollution (EVA) system to calculate the resulting health impacts and the associated external costs from each individual model. Along with a base case simulation, additional runs were performed introducing 20 % anthropogenic emission reductions both globally and regionally in Europe, North America and east Asia, as defined by the second phase of the Task Force on Hemispheric Transport of Air Pollution (TF-HTAP2).Health impacts estimated by using concentration inputs from different chemistry–transport models (CTMs) to the EVA system can vary up to a factor of 3 in Europe (12 models) and the United States (3 models). In Europe, the multi-model mean total number of premature deaths (acute and chronic) is calculated to be 414 000, while in the US, it is estimated to be 160 000, in agreement with previous global and regional studies. The economic valuation of these health impacts is calculated to be EUR 300 billion and 145 billion in Europe and the US, respectively. A subset of models that produce the smallest error compared to the surface observations at each time step against an all-model mean ensemble results in increase of health impacts by up to 30 % in Europe, while in the US, the optimal ensemble mean led to a decrease in the calculated health impacts by ~ 11 %.A total of 54 000 and 27 500 premature deaths can be avoided by a 20 % reduction of global anthropogenic emissions in Europe and the US, respectively. A 20 % reduction of North American anthropogenic emissions avoids a total of ~ 1000 premature deaths in Europe and 25 000 total premature deaths in the US. A 20 % decrease of anthropogenic emissions within the European source region avoids a total of 47 000 premature deaths in Europe. Reducing the east Asian anthropogenic emissions by 20 % avoids ~ 2000 total premature deaths in the US. These results show that the domestic anthropogenic emissions make the largest impacts on premature deaths on a continental scale, while foreign sources make a minor contribution to adverse impacts of air pollution.

Application Research on the Enterprise Value Evaluation Based on EVA of Energy Conservation and Environmental Protection Industry

Energy conservation and environmental protection industry is coming into a rapid developing period, there is urgent need to a reasonable assessment of the energy conservation and environmental protection enterprise target value with the scale up and frequencies of M&A activity. This research demonstrates the current situation of energy conservation and environmental protection industry in China, and analysis the application of EVA enterprise evaluation method in energy conservation and environmental protection industry. This research takes Beijing Sanju Environmental Protection & New Materials Company for example to assess the enterprise value, and compares with market capitalization, so it is effective and feasible to use EVA system in energy conservation and environmental protection enterprise value evaluation. Finally, the article points out the suggestion of application in energy conservation and environmental protection enterprise value evaluation based on EVA.

Effect of electrolyzed water and continuous ozone exposure on some aspects of clementine quality during conservation

Maintaining the quality of fruits and vegetables during postharvest is a difficult challenge. Due to regulation, there are few chemicals still available for postharvest application, and even those can be used only under restrictive conditions. The use of integrated strategies to protect the environment and minimize potential damages resulting from the use of pesticides is expected to increase. Among the possible strategies, the use of electrolyzed water (EW) looks very promising. EW has good antioxidant and antimicrobial effects and is an effective surface sanitizer. In this research, clementine citrus fruit were treated with EW produced by EVA System® 100 (Industrie De Nora S.p.A. Italy), in the field or immediately after harvest. Fruit were stored at 4±1°C for 20 days with or without gaseous ozone (O3) at 0.3 ppm, then at 23°C for 7 days. At the end of the storage period, decay severity, fungal contamination and fruit soluble solid content (SSC) were evaluated. The results showed that both EW treatment and O3 presence during storage at 4°C, significantly reduced microbial contamination and maintained SSC at values significantly higher than those on untreated fruit for the whole experimental period. However, the best effect was obtained when EW treatment was associated with storage in presence of O3. These results showed that it is possible to improve the quality of citrus fruit by low cost and easy to use strategies.

EVA in Economic Feasibility Study of Agricultural Water Project Investment in Crop Production Bases

There are many different methods and ways in terms of agricultural water project investment, but how to establish an efficient and scientific system to review the economic value is most important practically for investors. This study analyzes advantages and disadvantages of NPV index in current agricultural water project investments in crop producation bases, expounds in detail the EVA, which can measure the investment decision and operation performance, discusses the interconnection of EVA and common NPV, approves the equivalency between MVA and NPV in investment decision making and the equivalency of EVA and after-tax NAV and with comparison it is shown that EVA is more rational than NPV. Taking a agricultural water project as an example, it displays the EVA active function in project decision making and performance review and, further, it provides references in application of EVA system in future investment decision making.

Understanding User Perceptions of Eva [Commonwealth of Virginia E-Procurement System

This report explores the reasons for Virginia local governments’ currently low usage levels of eVA for procuring goods and services and what changes DPS might make to facilitate the localities’ increased use. This report explores the reasons why localities within the state of Virginia do or do not use the state’s electronic procurement system (eVA) in its two main forms eVA-Lite and eVA-Full. A group of four Master of Public Administration students at Virginia Commonwealth University have been tasked with researching the issue and providing recommendations to improve eVA and to make it more of an asset to the Commonwealth and its localities.eVA is owned and managed by the Virginia Department of General Services’ (DGS), Division of Purchases and Supply (DPS) and is the central procurement system for all nonconstruction and non-IT procurement needs for all state agencies and institutions. Research question: What are the reasons for local governments’ low use of eVA for procuring goods and services and what changes might DPS make to increase usage? Of the approximately $6 billion in expenditures procured by the state, localities currently make only 1.4 percent of those expenditures through the eVA procurement system. DPS is interested in understanding the reasons why localities do not use eVA for all essential goods and services. From DPS's perspective, using eVA will help increase local government’s access to essential goods and services through an affordable and efficient system. Methods of research and analysis include interviews with members of DPS; a survey sent to all localities that use eVA-Lite and eVA-Full, and observations of eVA outreach presentations to localities. The main findings revolve around the format of the eVA system and user’s understanding of the system. Survey findings suggest that many local governments perceive that eVA is not user-friendly and is time consuming. Additionally, responses from many local government procurers suggest the need for more education and training to better understand all aspects of the eVA system.Finally, the recommendations section offers considerations for DPS to improve the existing eVA system, according to the responses and suggestions of the survey participants. The recommendations fall under the areas of system changes, outreach and marketing strategies, and providing incentives for increasing local governments’ use of eVA.

Effect of silica‐based nanofillers on the properties of a low‐density polyethylene/ethylene vinyl acetate copolymer based thermoplastic elastomer

AbstractThe effect of pristine silica nanoparticles on a model low‐density polyethylene (LDPE)–ethylene vinyl acetate copolymer (EVA) thermoplastic elastomer blend system is explored in this article. Pristine silica nanoparticles were melt‐blended with the LDPE–EVA system at 1.5, 3, and 5 wt % loadings through the variation of the sequence of addition. In one of the compositions, coupling agent bis[3‐(triethoxysilyl)propyl] tetrasulfide (Si‐69) was used to improve the interaction of hydrophilic silica fillers with the polymer matrix. The blends were compression‐molded, and their mechanical, dynamic mechanical, and thermal properties, X‐ray diffraction patterns, and morphology were evaluated. The properties of the blends were found to be strong functions of the sequence of addition of nanofillers during their preparation. With Si‐69 as a coupling agent, the dynamic storage modulus of nanosilica‐based composites was found to increase up to 35%. An appreciable improvement in the tension set properties of the thermoplastic elastomer nanocomposites was observed in all the nanosilica‐based films. Morphological studies and dynamic properties clearly indicated that the differential properties of these blend systems primarily stemmed from the extent of dispersion and alternation of crystalline morphology, which in turn was a strong function of preferential incorporation in the LDPE or EVA matrix and the agglomeration tendency of the nanofillers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Preparation and morphological evolution of heterophasic PP‐EP/EVA/organoclay nanocomposites: Effect of the nanoclay organic modifier

AbstractA study is presented on the morphological effects caused by the nanoclay organic modifier and the nanoclay concentration. This was made under previously determined compatibility conditions of heterophasic polypropylene copolymers (PP‐EP)/poly(ethylene vinyl acetate) (EVA)/organoclay nanocomposites. The nanocomposites were prepared using the fluidity of the EVA phase to disperse the nanoclay platelets. Therefore, no additional compatibilizer was used to achieve the clay dispersion. Two organoclays were used with different characteristics and polarity of the substituent groups. Transmission electron microscopy and X‐ray diffraction results first indicated that two hydrogenated tallow modifiers are more effective than one to enhance nanoclay exfoliation. Thermogravimetric studies indicated a low probability of thermal degradation of the nanoclay modifiers and as a consequence of their effect on the layer–layer exfoliation. Molecular simulations were made with the purpose to study additional factors affecting exfoliation. The introduction of nanoclay, within the compatibility conditions of the PP‐EP/EVA system, was also studied. It was determined that the system preserved its original morphology and that the silicate layers were hosted by the EVA domains. The crystallization characteristics of the PP‐EP/EVA mixtures indicated a gradual evolution of the overall crystalline structures depending on the EVA content. In the case of the ternary nanocomposites PP‐EP/EVA/nanoclay, the β crystalline structure was partially formed, although it decreased with increasing nanoclay content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

AN EVA/UNMODIFIED NANO-MAGNESIUM HYDROXIDE/SILICONE RUBBER NANOCOMPOSITE WITH SYNERGISTIC FLAME RETARDANCY

A novel EVA/unmodified nano-magnesium hydroxide (NMH)/silicone rubber ternary nanocomposite was prepared by using a special compound flame retardant of NMH and silicone rubber (CFR). The flammability of the ternary composite was studied by cone calorimeter test (CCT). Synergistic effect on flame retardancy was found between silicone rubber and NMH. EVA/CFR ternary nanocomposite showed the lowest peak heat release rate (PHRR) and mass loss rate (MLR) among the samples of virgin EVA, EVA composites. The synergistic flame retardancy of silicone rubber and NMH in EVA system is attributed to the enhanced char layers in the condensed phase that prevents the heat and mass transfer in the fire.

Complex activity of clay and CNT particles in flame retarded EVA copolymer

AbstractInterface modifications optimized for fire retardancy require detailed research. Confocal Raman microscopy was used to analyze the degradation locally in the area of the nanotube and clay additives. The double‐walled carbon nanotube (DWCNT), containing Co catalyst residue, accelerates the deacetylation process of poly(ethylene‐co‐vinylacetate) (EVA) considerably, while the montmorillonite (MMT) has no significant influence under static circumstances. The compounding process influences the effect of MMT, which causes partial crosslinking in EVA during the compounding. This mechanochemical reaction is catalyzed by uncovered MMT particles, while organophillized MMT promotes the charring process. Inorganic surface modification with various metal ions has also some stabilizing effect. Spray drying of MMT results in microparticles of increased surface area and improved thermal stability of the EVA system. The lowest rate of flame spreading was achieved using uncoated MMT, while coating with cationic surfactant was most efficient for hindering dripping. The rate of heat release (RHR) of the organically modified and the spray dried MMT was approximately the same. The combined organic‐inorganic modified clay moderates both the dripping and the flame spreading in the EVA. Copyright © 2006 John Wiley & Sons, Ltd.

EVAcon: a protein contact prediction evaluation service

Here we introduce EVAcon, an automated web service that evaluates the performance of contact prediction servers. Currently, EVAcon is monitoring nine servers, four of which are specialized in contact prediction and five are general structure prediction servers. Results are compared for all newly determined experimental structures deposited into PDB (∼5–50 per week). EVAcon allows for a precise comparison of the results based on a system of common protein subsets and the commonly accepted evaluation criteria that are also used in the corresponding category of the CASP assessment. EVAcon is a new service added to the functionality of the EVA system for the continuous evaluation of protein structure prediction servers. The new service is accesible from any of the three EVA mirrors: PDG (CNB-CSIC, Madrid) (); CUBIC (Columbia University, NYC) (); and Sali Lab (UCSF, San Francisco) ().