Permanent Barrier Research Articles

Optic disc pit maculopathy: Covering or filling technique with human amniotic membrane patch to treat the optic disc pit maculopathy?

To describe two patients affected by optic disk pit-maculopathy ODP-M surgically treated with pars-plana vitrectomy (PPV) and the apposition of a human Amniotic Membrane (hAM) patch. Patients underwent a PPV with the apposition of a hAM patch to cover the ODP. In case 1, a 2nd surgery was necessary to push the hAM patch inside the pit, whereas in case 2 the patch was pulled inside the pit following the pressure gradient when infusion was turned on. After surgery the hAM patch filled the ODP and in both cases, during follow-up, there was a progressive reduction of macular OCT changes and a concomitant BCVA improvement. Our experience seems to support the idea that the dynamic fluctuation of pressure between intra-ocular and intra-cranial spaces can direct the movement of fluid through the anomalous communication created by the ODP. In this perspective, our cases seem to support the idea that the primary goal of any surgery should be to create a permanent barrier to fluid migration through the ODP to the intra-ocular space, and that hAM can be successfully used to fill the OPD and to create that permanent barrier to achieve the resolution of ODP-M.

Reduction of amphibian roadkill by one-side barriers

Amphibians are the most affected vertebrates by roadkill. Often, to minimise this problem mitigation barriers are installed. While two-side barriers effectiveness is well described in the literature, one-side barriers are poorly studied. The present study aimed to evaluate the effectiveness of one-side barriers installed by LIFE LINES project along the EM535 road in south-east Portugal. Two types of one-side barriers (one permanent and another temporary one made from tarp) were monitored through road surveys. For each barrier, the influence of interaction between the period (before and after the barrier installation) and road sector (control-no barrier, permanent or temporary barrier installed) on the number of amphibians was evaluated. The result showed that, contrary to the temporary barrier, the permanent one-side barrier appeared to be effective. Thus, the ineffectiveness of the temporary barrier may be related to (i) the tarp material that allows some amphibians to escape, (ii) the presence of vegetation that goes over the top of the barrier, or (iii) increased fence-end effects due to its short length. Even though less effective than two-side barriers, one-side barriers could be installed when there is budget limitation in conservation projects or if land use conflicts exist. Given that our study was the first to evaluate the effectiveness of one-side barriers, we discuss the potential constrains that may have affected our results.

Laboratory Earthquake Rupture Interactions With a High Normal Stress Bump

AbstractTo better understand how normal stress heterogeneity affects earthquake rupture, we conducted laboratory experiments on a 760 mm poly (methyl‐mathacrylate) PMMA sample with a 25 mm “bump” of locally higher normal stress (∆σbt). We systematically varied the sample‐average normal stress () and bump prominence (). For bumps with lower prominence () the rupture simply propagated through the bump and produced regular sequences of periodic stick‐slip events. Bumps with higher prominence () produced complex rupture sequences with variable timing and ruptures sizes, and this complexity persisted for multiple stick‐slip supercycles. During some events, the bump remained locked and acted as a barrier that completely stopped rupture. In other events, a dynamic rupture front terminated at the locked bump, but rupture reinitiated on the other side of the bump after a brief pause of 0.3–1 ms. Only when stress on the bump was near critical did the bump slip and unload built up strain energy in one large event. Thus, a sufficiently prominent bump acted as a barrier (energy sink) when it was far from critically stressed and as an asperity (energy source) when it was near critically stressed. Similar to an earthquake gate, the bump never acted as a permanent barrier. In the experiments, we resolve the above rupture interactions with a bump as separate rupture phases; however, when observed through the lens of seismology, it may appear as one continuous rupture that speeds up and slows down. The complicated rupture‐bump interactions also produced enhanced high frequency seismic waves recorded with piezoelectric sensors.

A new formulation of screwworm fly attractant with reduced hazardous chemicals and transport restrictions.

New World screwworm flies, Cochliomyia hominivorax (Coquerel), are obligate parasites of warm-blooded animals. They were eradicated from North and Central America during the mid-20th to early-21st centuries using the sterile insect technique (SIT), a method presently employed to maintain a permanent barrier between Central and South America. Lures are an important component of the screwworm eradication program, where they are used for surveillance, sample collection, and strain evaluation in the field. The first chemical lure, later named swormlure, was developed based on the attractiveness of C. hominivorax to volatile organic compounds (VOCs) produced from decomposing animal tissues. The formulation has changed little over the years and presently contains 10 chemicals, one of which is dimethyl disulfide (DMDS). Restrictions on the transport of DMDS have recently impeded its use in swormlure-4 (SL-4). However, dimethyl trisulfide (DMTS) is not as highly restricted and can be shipped via air transportation. Both chemicals are produced by microbial decomposition of animal tissues. Here, we conducted field trials using three releases of sterile C. hominivorax, each comprising approximately 93,000 flies, to test the efficacy of SL-4, containing DMDS, to swormlure-5 (SL-5) containing DMTS. Traps baited with SL-4 and SL-5 captured 575 (mean = 191.7, SD 17.9) and 665 (mean = 221.7, SD 33.2) C. hominivorax, respectively (df = 19, F = 1.294, P = 0.269). However, traps baited with SL-5 captured considerably more Cochliomyia macellaria (Fabricius), a closely related but nontarget fly.

Simulation study of cement plug micro-annulus in milling section of abandoned wells

When the integrity of the annular barrier outside the casing is degraded, parts of the casing in the abandoned well must be milled to place a permanent barrier. Considering the micro-annulus induced by accumulation fluid, this paper developed a 3D finite element model of cement plug in the milling section. Monte Carlo methods evaluated the fluid accumulation rate as a part of the model. The model simulated the micro-annulus propagation at the cement-formation interface under the fluid-driven force. The influence of milling position and reaming radius was analyzed. Meanwhile, the influence of the Poor Bonding Zone (PBZ) was analyzed based on a new method of simulating bonding quality. Simulation results show that the accumulation fluid affects the interface stress state and induces the micro-annulus. The initial stress of the interface is non-uniformly distributed under non-uniform in-situ stress, and the micro-annulus tends to expand along the axial direction. The selection of low Young's modulus, high Poisson's ratio, and low permeability formation region for milling is beneficial. The micro-annulus is highly sensitive to PBZ, and reducing the proportion of PBZ on the bonding face is significant in preventing barrier leakage. The results of this paper are essential for permanent barrier design and prevention of leakage.

Outlines to Initiate Epilepsy Surgery in Low- and Middle-Income Countries.

Surgery is an essential treatment option for patients with drug-resistant epilepsy. While most epilepsy patients worldwide live in low- and middle-income countries (LMIC), most of these countries do not have epilepsy surgery, and those that do have surgical epilepsy services lack capacities. The rapidly growing population in LMIC further widens the gap between the number of patients who can potentially benefit from surgery and those who can actually receive it. This makes the initiation of new surgical epilepsy centers in those countries an urgent issue. Epilepsy surgery is feasible in LMIC, even in resource-poor settings, but lack of local expertise is a major obstacle to the introduction of new surgical services. Importantly, expertise deficits can be compensated by collaborating with a well-established epilepsy center for knowledge transfer, skill building and mentoring. Such projects need to be organized in a multidisciplinary team, should focus on the given circumstances, and should use technologies and personnel that are reasonably available and can function sustainably. Local cultural factors and improvement of patients' quality of life are further spotlights reflected by an increasing number of studies. As a general outline for a new surgical epilepsy program in LMIC, it is recommended to initially focus on patients with mesial temporal lobe epilepsy due to hippocampal sclerosis or other well defined pathologies. These constellations have an excellent surgical outcome in terms of seizure control, can be diagnosed by non-invasive methods, and can be reliably identified even under low-resource conditions. Moreover, surgery can be performed with a highly standardized approach and at reasonable costs, and the vast majority of patients will benefit from surgical intervention. The range of services can then be gradually expanded, depending on growing expertise, local needs, prospects and constraints. Although the introduction of surgical epilepsy services in LMIC can face several challenges, none of them should be a permanent barrier for further establishments.

Impacts of Storm Surge Barriers on Drag, Mixing, and Exchange Flow in a Partially Mixed Estuary

AbstractStorm surge barriers are increasingly being considered as risk mitigation measures for coastal population centers. During non‐storm periods, permanent barrier infrastructure reduces the flow cross‐sectional area and affects tidal exchange. Effects of barrier structures on estuarine tidal and salinity dynamics have not been extensively examined, particularly for partially mixed estuaries. A nested, high‐resolution model is used to characterize impacts of a potential storm surge barrier near the mouth of the Hudson River estuary. Maximum tidal velocities through barrier openings are more than double those in the base case. Landward of the barrier, tidal amplitude decreases on average by about 6% due to increased drag. The drag coefficient with the barrier is about 5 times greater than the base case due primarily to form drag from flow separation at barrier structures rather than increased bottom friction. The form drag scales with barrier geometry similar to previous studies of flow around headlands. Tidal water levels are reduced particularly during spring tides, such that marsh inundation frequency is reduced up to 25%. Strong tidal velocities through barrier openings enhance salinity mixing locally, but overall mixing in the estuary decreases due to reduced tidal velocities. Correspondingly, stratification decreases near the barrier and increases landward in the estuary. The salinity intrusion length increases by 5%–15% depending on discharge due to the decreased mixing and increased exchange flow. Exchange flow increases near the barrier due reflux into the lower layer with the increased mixing, which has the potential to increase estuarine residence times.

Geographic Population Genetic Structure of the New World Screwworm, Cochliomyia hominivorax (Diptera: Calliphoridae), Using SNPs.

The New World screwworm, Cochliomyia hominivorax (Coquerel 1858) (Diptera: Calliphoridae), is a serious parasite of livestock, humans, and other warm-blooded animals. It has been eradicated from the northern parts of its historical range down to the Panama-Colombian border where a permanent barrier zone is maintained. This eradication was accomplished through using the sterile insect technique (SIT). In 2016 there was an outbreak of C. hominivorax in the Florida Keys. In only six months, this pest was successfully re-eradicated using SIT, but the geographic origin of the invasion has yet to be resolved. It was previously determined that the Florida flies most likely represented a single invasion, and it was recommended that a finer-scale genetic assessment should be completed. Thus, this current proof-of-concept study aimed to develop a population genetic database using single nucleotide polymorphisms (SNPs) to reference outbreaks and potentially identify the origin of the Florida outbreak. This initial database consists of wild-caught samples from 4 geographic locations as well as laboratory colony samples that originated from 7 additional locations using a genotyping by sequencing (GBS) approach. Geographic population structuring was identified for twelve populations that clustered according to geographic location. The Florida outbreak samples appeared similar to samples from the outer Caribbean cluster which included samples from Dominican Republic and Trinidad and Tobago, however, these results will be further clarified with the replacement of laboratory colony samples with future wild-caught samples.

Flexible InGaP/GaAs Tandem Solar Cells Encapsulated with Ultrathin Thermally Grown Silicon Dioxide as a Permanent Water Barrier and an Antireflection Coating

The lifetime and stability of flexible photovoltaic (PV) devices are crucial factors in the production of sustainable and eco-friendly energy. However, flexible PV devices are usually constructed with a thin active material integrated onto a soft substrate, the surfaces of which are prone to moisture and heat damage, making devices unreliable in terms of their lifetime and stability. Here, we built flexible InGaP/GaAs tandem solar cells with an ultrathin thermally grown silicon dioxide layer as a permanent water barrier and an antireflection coating (ARC). By transferring an ultrathin thermally grown silicon dioxide onto flexible InGaP/GaAs tandem solar cells, there was no performance degradation even after soaking the solar cells in water at 70 °C for 10 days. Furthermore, the energy conversion efficiency of the solar cell with a thermally grown silicon dioxide layer was improved by 2.24% due to antirefletion effect compared with that of the solar cells without the silicon dioxide layer. Such device technology establishes a stable energy source not only for vehicles, satellites, and drones exposed to harsh environments but also for underwater operating systems and sensors.

Historical perspective and new avenues to control the myiasis-causing fly Cochliomyia hominivorax in Uruguay

‘Mosca de la bichera’ or simply ‘bichera’ are common names given in Uruguay and the region to the primary myiasis-causing species Cochliomyia hominivorax, the New World Screwworm (NWS) fly (Diptera: Calliphoridae). Myiasis happens when dipteran larvae infest live animals at least during some developmental phase to feed on host’s flesh and fluids. For the NWS fly it is mandatory that all three larvae phases develop on living tissues of warm-blooded vertebrates, including humans. Unsurprisingly, this parasitic behavior causes great profit losses to the livestock industry and is also considered a neglected public health issue. NWS is endemic from the tropics and subtropics of the Americas, but has been eradicated from North and Central America through a Sterile Insect Technique (SIT) based Area Wide – Integrated Pest Management (AW-IPM) program that lasted more than 50 years. Since 2004, a permanent barrier is actively maintained in Darien, along the Panama-Colombian border, by releasing 14 million sterile flies per week to avoid reintroductions. Due to its direct and indirect impact on the national economy, the logistic complexity and the cost of SIT control programs, much discussion is underway in Uruguay about NWS fly eradication. Direct economic losses due to myiasis in Uruguay oscillate between USD 40 and 154 million annually (i.e., between 2-8% of livestock Gross Domestic Product, GDP). Currently, the Food and Agriculture Organization of the UN/International Atomic Energy Agency (FAO/IAEA) and the US Department of Agriculture/Panama United States Commission for the Eradication and Prevention of Screwworm/ Ministry of Livestock, Agriculture and Fisheries (USDA/COPEG/MGAP) have been working on eradication proposals for Uruguay. Cost-benefit analysis of each group concluded that a net present value of around USD 98 million and USD 146 million could be achieved, respectively, supporting the positive impact of NWS fly eradication at local farmers and the whole livestock sector levels. The main challenge of this endeavor is to find a way to keep the myiasis-free status of Uruguay in case that its neighbors, Argentina and Brazil, do not engage in a similar program, at least for their southernmost region. Here we review the bulk of bibliography produced since the beginning of NWS eradication programs in North America during the 40s decade, its life cycle and parasitic lifestyle as well as many aspects of its population genetics and ecology. We further discuss promising biotechnological approaches under active development based on transgenesis and CRISPR/Cas genome-editing, that are considered the new avenue in insect-control strategies. Balance among innovation and regulation framework is considered based on lessons learned. Currently, a CRISPR/Cas gene editing strategy for gene drive is being investigated in Uruguay, a development conducted with national funds, what guarantees its complete control and local institutions, authorities and ultimately livestock producers can be the biotechnology owners. Finally, we highlight the know-how that will be generated opening the possibility to locally develop new genetic-based control strategies for other parasites and/or vector insects of high veterinary and public health relevance.

The Melagiri Elephant Fence - A Crucial tool for Human-Elephant Control

Effectively restraining elephants within forests and away from human use areas is critical to solving human-elephant conflict (HEC). Present methods such as solar fences, elephant proof trenches, alarm systems, scaring and driving methods have met with mixed results and not achieved the desired reduction in elephant crop depredation, human and elephant deaths. This case study showcases the successful development of the Melagiri Elephant Fence, using steel wire rope strands and precast steel reinforced concrete posts as the primary elements of the fence. The Melagiri Elephant Fence was field-tested in a high human-elephant conflict area of the Hosur Forest Division and monitored using camera traps. The final design of the fence was successful in containing even the most persistent and largest bull elephants. The Melagiri Elephant Fence is a cost-effective, permanent and maintenancefree elephant proof barrier for landscape-level occupancy planning and mitigation of human-elephant conflict. No injury to elephants, humans or other animals have been reported, and the fence may be considered as safe for use.

Technology Focus: Cementing and Zonal Isolation (May 2021)

Wow! What a year it has been! We have experienced enormous upheavals in our professional and social circles and wholescale changes in the way that we interact with each other. As engineers, though, we recognize that in every challenge there is an opportunity. I have been lucky to attend SPE online events, including a happy hour and a webinar on geothermal energy. As we witness a shift to renewable energy, I note that 2020 SPE President Shauna Noonan highlighted that our SPE professional expertise in the subsurface will be needed to both maintain existing energy production and develop new sources of energy. Cementing, zonal isolation, and well integrity continue to be an important piece of the puzzle. This year, in the presence of enormous challenges, the selected papers demonstrate step changes both in efficiency and in the results of cementing operations. Managed-pressure cementing extends the benefits of managed-pressure drilling, and a successful case is described in paper OTC 30481. Last year, we read about offline cementing in North America. Offline cementing continues to increase rig efficiency, and wellhead equipment that enables offline cementing is described in paper SPE 202439. Improving cementing results by enabling casing rotation with rotating cement heads is discussed in paper SPE 198970. Research that will enable future successful changes also continues. Although not summarized in this edition, extra reading is recommended for interesting discussions on proving shale as a barrier (SPE 200755), cement properties and initial state of stress in confined pressure conditions (SPE 201770), and the evaluation of neutron logging as a possible cement evaluation tool (SPE 202973). As an industry, we also continue to investigate materials that will provide effective isolation in the annulus. Papers about self-healing systems (SPE 203174), epoxy (SPE 202648), and expanding metal sealing systems (SPE 203354) are also recommended as extra reading. Although it has been a challenging year, operational improvements, research, and material investigation continue to provide engineering opportunities in cementing and zonal isolation. Recommended additional reading at OnePetro: www.onepetro.org. SPE 200755 - Innovative One-Trip System Helps Qualify Creeping Shale as Permanent Barrier for Plug and Abandonment of Wells on the Gyda Field by Thore Andre Stokkeland, Archer, et al. SPE 201770 - Laboratory Measurement of Cement Stress Before, During, and After Curing Under Undrained Condition With Constant Hydrostatic Pressure by Meng Meng, Los Alamos National Laboratory, et al. SPE 202973 - Potential Usage of Neutron Logging Technology for Casing Cement Evaluation—Feasibility Study by Espen Dommersnes, University of Stavanger, et al. SPE 203174 - A Game-Changing Technology for Cementing in Highly Deviated and Horizontal Wells Using Interactive Mud-Sealing Cement System by Choosak Orprasert, Mubadala Petroleum, et al. SPE 202648 - Primary Cementing Using Epoxy Resins as Additive: Experimental and Application by Khawlah Abdulaziz Alanqari, Saudi Aramco, et al.

An early female lethal system of the New World screwworm, Cochliomyia hominivorax, for biotechnology-enhanced SIT

BackgroundThe New World Screwworm fly (NWS), Cochliomyia hominivorax, is an ectoparasite of warm-blooded animals and a major pest of livestock in parts of South America and the Caribbean where it remains endemic. In North and Central America it was eradicated using the Sterile Insect Technique (SIT). A control program is managed cooperatively between the governments of the United States and Panama to prevent the northward spread of NWS from infested countries in South America. This is accomplished by maintaining a permanent barrier through the release of millions of sterile male and female flies in the border between Panama and Colombia. Our research team demonstrated the utility of biotechnology-enhanced approaches for SIT by developing a male-only strain of the NWS. The strain carried a single component tetracycline repressible female lethal system where females died at late larval/pupal stages. The control program can be further improved by removing females during embryonic development as larval diet costs are significant.ResultsThe strains developed carry a two-component system consisting of the Lucilia sericata bottleneck gene promoter driving expression of the tTA gene and a tTA-regulated Lshid proapoptotic effector gene. Insertion of the sex-specifically spliced intron from the C. hominivorax transformer gene within the Lshid gene ensures that only females die when insects are reared in the absence of tetracycline. In several double homozygous two-component strains and in one “All-in-one” strain that had both components in a single construct, female lethality occurred at the embryonic and/or first instar larval stages when raised on diet without tetracycline. Laboratory evaluation for phenotypes that are relevant for mass rearing in a production facility revealed that most strains had fitness characteristics similar to the wild type J06 strain that is currently reared for release in the permanent barrier. Testing of an “All in one” strain under mass rearing conditions showed that the strain maintained the fitness characteristics observed in small-scale rearing.ConclusionsThe early female lethal strains described here could be selected by the NWS Control Program for testing at large scale in the production facility to enhance the efficiency of the NWS eradication program.

Let-7g* and miR-98 Reduce Stroke-Induced Production of Proinflammatory Cytokines in Mouse Brain.

Stroke is a debilitating illness facing healthcare today, affecting over 800,000 people and causing over 140,000 deaths each year in the United States. Despite being the third-leading cause of death, very few treatments currently exist for stroke. Often, during an ischemic attack, the blood-brain barrier (BBB) is significantly damaged, which can lead to altered interactions with the immune system, and greatly worsen the damage from a stroke. The impaired, BBB promotes the infiltration of peripheral inflammatory cells into the brain, secreting deleterious mediators (cytokines/chemokines) and resulting in permanent barrier injury. let-7 microRNAs (miRs) are critical for regulating immune responses within the BBB, particularly after ischemic stroke. We have previously shown how transient stroke decreases expression of multiple let-7 miRs, and that restoration of expression confers significant neuroprotection, reduction in brain infiltration by neutrophils, monocytes and T cells. However, the specific mechanisms of action of let-7 miRs remain unexplored, though emerging evidence implicates a range of impacts on cytokines. In the current study, we evaluate the impacts of miR-98 and let-7g* on targeting of cytokine mRNAs, cytokine release following ischemic stroke, and cell-specific changes to the neurovascular space. We determined that miR-98 specifically targets IP-10, while let-7g* specifically aims IL-8, and attenuates their levels. Both produce strong impacts on CCL2 and CCL5. Further, let-7g* strongly improves neurovascular perfusion following ischemic stroke. Together, the results of the study indicate that let-7 miRs are critical for mediating endothelial-immune reactions and improving recovery following ischemic stroke.

Can Ferret Badgers (Melogale moschata) Cross the Rabies Epidemic Boundary in Western Taiwan?

Taiwan was considered rabies-free for > 50 years until the disease reemerged in its ferret badger population (Melogale moschata) in 2013. Although it is still expanding slowly northward in eastern Taiwan, its spread in the west has thus far been halted by the Da-An River. To prevent diffusion of rabies, an immunization zone should be established along the epidemic boundary before further rabies expansion crosses it. This study developed 19 microsatellite markers with tri- or tetra-nucleotide motifs specifically for ferret badgers using next generation sequencing, and we used these markers to evaluate level of gene flow across the Da-An River. Low levels of genetic differentiation and high levels of gene flow across the river indicated that the Da-An River was not a permanent barrier to rabies. Rabies may eventually be able to expand across this temporary boundary. We suggest that an immunization zone should be established along the Da-An River as soon as possible.

The effect of a permanent saltwater barrier on Rangia cuneata, an indicator species of brackish conditions

Rangia cuneata is a brackish water clam with a broad distribution along western Atlantic coasts and is an important component of estuarine communities. Adult R. cuneata are tolerant of salinities ranging from 0 to 32 but limited experimental studies have indicated that spawning and larval development are constrained to salinities between 2 and 10. In 2003, a permanent saltwater barrier was built in the lower Neches River, Texas, that partitioned a population of R. cuneata that had been surveyed since the 1950s. The barrier prevented salt water intrusions upstream and provided a natural experiment to determine how the regulation of salinity intrusion can influence R. cuneata spawning, recruitment, and establishment. We surveyed a total of 12 historical sites (eight above and four below the barrier) plus one site outside the previous surveys. Above the barrier, five sites had no living R. cuneata and the remaining three sites had very low densities (<0.2 per m−2). The large sizes of the few R. cuneata above the barrier (mean = 65.8 mm) suggested no spawning, with energy instead being invested into somatic growth. It also demonstrated the effectiveness of the barrier in preventing the continued recruitment of R. cuneata upstream and supports the hypothesis that non-zero salinity levels are needed for successful reproduction of the species. Populations downstream from the barrier experienced a resurgence in population size since the last survey in 1992, with one site having >86 individuals m−2. The presence of distinct size cohorts indicated that spawning and recruitment occurs sporadically. Using the results of previous research, we defined the conditions apparently needed for successful reproductive events as warm weather periods with a salinity change (≥4 over a week) to induce spawning and elevated salinity levels (2–10 for 15+ days) for larval development. Using these criteria, we identified three salinity influx events on the lower Neches River in the last eight years that correlate with the presence of the size cohorts observed below the barrier, which support the hypothesis that salinity fluxes and durations are needed to induce spawning and facilitate larval recruitment.

Can Redo Sternotomy Become as Easy as First-Time Sternal Opening?

Injury to vital vascular and cardiac structures is a redoubtable complication associated with redo sternotomy. This may be one reason why the pericardium should be closed whenever possible at least over the great vessels and the cranial part of the heart in every patient. This is of particular importance in those patients in whom a redo surgery may be expected (congenital surgery, valvular reconstruction and/or implantation of tissue valves, implantation of left ventricular device as bridging therapy). In many patients, however, a complete closure of the pericardium is not possible because of the intraoperative swelling of the heart or just because the necessary filling of the heart at the end of the procedure precludes a tension-free pericardial closure. In these cases, implantation of a pericardial or artificial membrane as pericardial replacement may be a wise decision. Independently of the presence of a membrane or not, computed tomography or magnetic resonance imaging is of great value before reopening the sternum to estimate the proximity of the posterior surface of the sternum to the most important cardiovascular structures (right ventricle, ascending aorta, innominate vein) or previous implants (pulmonary conduit or homograft, and saphenous vein grafts or internal thoracic artery in case of previous coronary artery bypass grafting). Previous subcutaneous implantation of different pericardial replacement patches in a porcine model has shown the following results: CorMatrix (CorMatrix Cardiovascular, Inc, Sunnyvale, CA) showed gradual and consistent patch resorption and subsiding inflammatory and fibrosis process. Full scaffold degradation and replacement by mild fibrosis and subcutaneous tissue were seen by 1 year. Xenopericardial patches remained intact, and the initially severe inflammatory and fibrotic reactions reduced gradually to moderate fibrosis and chronic inflammation. Gore-Tex (W.L. Gore & Assoc, Flagstaff, AZ) showed foreign body reaction.1Mosala Nezhad Z. Poncelet A. Fervaille C. Gianello P. Comparing the host reaction to CorMatrix and different patch materials implanted subcutaneously in growing pigs.Thorac Cardiovasc Surg. 2019; 67: 44-49Crossref PubMed Scopus (6) Google Scholar The GoreTex polytetrafluoroethylene membrane has most probably been the most frequently implanted pericardial substitute so far. Its protective effects in case of redo sternotomy are recognized, but the adhesions with the epicardial surfaces may be strong. Among more recent alternatives, CorMatrix has been described as an interesting recellularized scaffold but the results among different studies were somewhat conflicting,2Bustamante-Munguira J. Serrano R. Figuerola-Tekerina A. et al.Is CorMatrix really a recellularization scaffold as a pericardial substitute in cardiac surgery?.J Cardiovasc Surg (Torino). 2018; 59: 142-143PubMed Google Scholar whereas bovine pericardium subjected to a novel anticalcification tissue-engineering process (CardioCel, LeMaitre Vascular, Inc, Burlington, MA) seems promising: A neointimal layer of varying thickness developed on the visceral surface of 5 CardioCel explants with endothelialization of the longest duration explant.3Prabhu S. Armes J.E. Bell D. et al.Histologic evaluation of explanted tisue-engineered bovine pericardium (CardioCel).Semin Thorac Cardiovasc Surg. 2017; 29: 356-363Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar In this issue of The Annals of Thoracic Surgery, Hu and coauthors4Hu C. Tang F. Wu Q. et al.Novel trilaminar polymeric anti-adhesion membrane prevents postoperative pericardial adhesion.Ann Thorac Surg. 2021; 111: 184-190Abstract Full Text Full Text PDF Scopus (8) Google Scholar from Beijing have to be congratulated for another important step—that is, a novel trilaminar membrane that was compared (mainly adhesive effects) to the well-known expanded polytetrafluoroethylene membrane in an animal study. The goal of this new membrane is to minimize post-sternotomy adhesions (through the resorbable components) while maintaining a permanent physical barrier (through the middle layer). All layers contain a novel polymer made of polyvinyl alcohol and carboxymethylcellulose. Because the generation of adhesions and granulation tissue are most active 5 to 7 days after implantation and adhesions become stable approximately from day 14 post implantation, the new material resorbs rapidly after implantation during initial surgery. This might be of particular interest if, for any reason, a reexploration becomes necessary during the early follow-up period. Looking at the microscopic specimen in animals, every cardiac surgeon may be eager to have this new pericardial replacement membrane in their fingers as soon as available on the market. Novel Trilaminar Polymeric Antiadhesion Membrane Prevents Postoperative Pericardial AdhesionThe Annals of Thoracic SurgeryVol. 111Issue 1PreviewPostoperative pericardial adhesion formation is a prominent cause of morbidity and death in cardiovascular surgery, but there is still no ideal prevention method, especially in redo cases. This study investigated a novel antiadhesion trilaminar polymeric film compared with the Gore PRECLUDE Pericardial Membrane (W. L. Gore & Associates, Flagstaff, AZ) and a negative control. Full-Text PDF

Predictive simulation of leachate transport in a coastal lateritic aquifer when remediated with reactive barrier of nano iron

The current study focuses on determination of extent of groundwater contamination on a typical tropical coastal aquifer due to a landfill located at Vamnjoor in Dakshina Kannada district, India with the help of groundwater flow model, MODFLOW and MT3DMS when remediated with permanent reactive barrier of nano iron. The aquifer considered is a shallow, unconfined one with laterite soil which gets good rains during monsoon and will be dry during rest of the year. The adsorption by laterite soil has been considered. The specific yield and transmissivity were estimated to be 7.85% and 213m2/day respectively. After calibrating successfully with Nash–Sutcliffe efficiency 0.8, horizontal hydraulic conductivity was set as 7 m/day. Validation of model was then done with the field data and is applied for forecasting the spread of contaminant for anticipated future scenarios. The results show that in spite of retardation offered by lateritic soil, contaminant trail is expanding with a velocity of 0.15 m/day in downstream direction. When permeable reactive barrier of nano iron which can adsorb nearly 65% of chemical oxygen demand is installed, it is showing that the contaminant spread can be reduced to 400 mg/l at the observation well located at 1 km from landfill. Hence a comprehensive remedial alternative of permanent reactive barrier of nano iron can be recommended for preventing groundwater contamination from landfill leachate.

The Luxury value in the AI era. A new “quality growth paradigm” is born!

The high prices associated with quality are a permanent barrier for the majority to access high quality and luxury, as the two concepts &#8220;democratization of luxury&#8221; and &#8220;luxury as quality and rarity&#8221; seemed to be contradiction in terms. But a new growth paradigm was identified if we apply quantic approach and functional economy approach to the analysis of the potential new &#8220;forms of luxury&#8221; (&#8220;luxury functionalities), which could be in the same time &#8220;not luxury quality&#8221; and &#8220;luxury quality&#8221; depending on the &#8220;observer&#8221;, after the analogy with &#8220;the cat and the paradox of Schrodinger&#8221;. But in the digital world, the &#8220;observer&#8221; is demultiplexed, the observation is in real time and continuously). Luxury domain could inspire and generalize the &#8220;augmented value creation&#8221; by &#8220;open valorization strategies&#8221; and scaled-up by national regulatory support (for example, the Law PACTE in France, the country where fashion and luxury adds to more than 42 milliards and 86% exports). New research will be conducted on this potential &#8220;augmented quality growth paradigm&#8221; inspired by the luxury new business model.JEL codes: D460, D470, D230, D210, (D82, D83, D84), P420, P470, E710.

Review of the Effectiveness of Composite Barrier Mesh Used for Laparoscopic Ventral Hernia Repair

Background: The objective of this research is to provide an overview of the physical and biomechanical properties of composite barrier meshes frequently used in Laparoscopic Ventral Hernia Repair as well as reviewing the existing relevant literature assessing the characteristics and effectiveness of both procedures. Methods: A secondary research is used using existing literature review of the preclinical and clinical literature designed to compare the Composite prostheses with permanent barriers (COMPOSIX, VENTRIO, DUALMESH, DYNAMESH and TiMESH ) to composite prostheses with absorbable barriers ( PROCEED, C-QUR, PHYSIOMESH, PARIETEX and SEPRAMESH ). Results: Significant differences were observed between Composite prostheses with regard to its physical and biomechanical properties. Amongst the permanent barrier meshes, Dualmesh showed the highest suture retention strength. On the other hand, between the absorbable barrier meshes, Sepramesh proved to have the most significant suture retention and tears strength. Overall, all meshes established tensile strengths greater than 16-32 N/cm. Moreover, that composite meshes with absorbable barriers had less complications of adhesions, recurrences and wound infection compared with meshes with permanent barriers. Conclusion: Composite meshes with absorbable barriers proved to be superior to permanent ones. Other findings demonstrated there was no significant difference of effectiveness among absorbable barriers.