A retrospective analysis of the causes of postoperative ventral hernia recurrence

Considering the results of surgical treatment of postoperative ventral hernia, a significant number of recurrences of 4.3–46 % should be noted, and in case of large and giant postoperative ventral hernias reaches up to 80 %, which is associated with demographic imbalance that is an increase in the number of persons of old and senile age with comorbidity typical for them. Excessive obesity, especially in women, requires a revision of the main surgical approaches in the choice of methods of hernioplasty. Failure to take into account the present syndrome of undifferentiated connective tissue dysplasia (UCTD) in the performance of hernioplasty and allohernioplasty in 60 % of cases leads to postoperative relapse.Objective. On the basis of the analysis of the performed surgical treatment of patients with ventral and postoperative ventral hernia, to study the main causes of the development of recurrent hernia, which would improve the results of surgical treatment of this category of patients.Materials and methods. The clinical section of the work is based on a retrospective analysis of the results of surgical treatment of 1419 patients who underwent surgery on the anterior abdominal wall for primary ventral and postoperative ventral hernias. The distribution of patients into groups was according to the periods of surgical treatment of patients: from 2001 to 2009 and from 2010 to2017. In the first period, 597 (42.07%) patients who made the comparison group were examined and operated. The main group (2010–2017) amounted to 822 (57.93 %) patients.To determine the localization, size and extent of hernial bulging in defects of the anterior abdominal wall, we used the classification of the European Association of Surgeons-Herniologists (EHS-classification, 2008).In the comparison group, R1 was observed in 123 (93.18 %) patients, R2 – in 6 (4.55 %), R3 – in 2 (1.51%), R4 and more – in 1 (0.76 %). In the main group: R1 was observed in 63 (71.59 %) patients, R2 – in 18 (20.45 %), R3 – in 5 (5.68 %), R4 and more – in 2 (2.28 %).Results. In 250 (17.62 %) patients, recurrent hernia developed after various types of surgery. The highest recurrence rate was observed in patients after own tissue hernioplasty, which was 36.07 % of all operated patients according to this procedure. In second place, by the frequency of relapse were patients after performed allohernioplasty using inlay technique – 19.63 %. The recurrence rate after allohernioplasty by the onlay technique is, according to our study, 10.58 %. After performing the sublay technique, the results obtained differ significantly with a low percentage of relapses compared to other methods of hernioplasty. Thus, the recurrence was only in 6.01 % of cases. The only method of surgical treatment of POVH with no recurrence was the method of hernioplasty with anatomic separation of the components of the anterior abdominal wall (CST), which was performed in two variants – without the use of polypropylene mesh (PPM) by Ramirez and combined one using PPM. Such data may be explained by the small number of completed surgery interventions (45 (3.17%)) and short observation periods (4 years).Conclusions. Analyzing the causes of recurrence, it can be argued that the main ones are the choice of inadequate method of hernioplasty to a specific clinical situation, incomplete revision of the musculo-aponeurotic layer of the anterior wall, especially in patients with postoperative ventral hernias and concomitant undifferentiated connective tissue dysplasia and obesity, the presence of hidden (small in size and clinically intact) defects and weaknesses, incorrect choice of mesh implant type (“light” or “heavy” polypropylene mesh) and its size, choice of inappropriate material thickness

Engineering Cu2O Nanowire Surfaces for Photoelectrochemical Hydrogen Evolution Reaction

Cu2O is a narrow band gap material serving as an important candidate for photoelectrochemical hydrogen evolution reaction. However, the main challenge that hinders its practical exploitation is its poor photostability, due to its oxidation into CuO by photoexcited holes. Here, we thoroughly minimize the photo-oxidation of Cu2O nanowires by growing a thin layer of the TiO2 protective layer and an amorphous layer of the VOx cocatalyst using magnetron sputtering and atomic layer deposition, respectively. After optimization of the protective and the cocatalyst layers, the photoelectrode exhibits a current density of -2.46 mA/cm2 under simulated sunlight (100 mW/cm2) at 0.3 V versus reversible hydrogen electrode, and its performance is stable for an extended illumination time. The chemical stability and the good performance of the engineered photoelectrode demonstrate the potential of using earth-abundant materials as a light-harvesting device for solar hydrogen production

Design and performance of ropes for climbing and sailing

Ropes are an important part of the equipment used by climbers, mountaineers, and sailors. On first inspection, most modern polymer ropes appear similar, and it might be assumed that their designs, construction, and properties are governed by the same requirements. In reality, the properties required of climbing ropes are dominated by the requirement that they effectively absorb and dissipate the energy of the falling climber, in a manner that it does not transmit more than a critical amount of force to his body. This requirement is met by the use of ropes with relatively low longitudinal stiffness. In contrast, most sailing ropes require high stiffness values to maximize their effectiveness and enable sailors to control sails and equipment precisely. These conflicting requirements led to the use of different classes of materials and different construction methods for the two sports. This paper reviews in detail the use of ropes, the properties required, manufacturing techniques and materials utilized, and the effect of service conditions on the performance of ropes. A survey of research that has been carried out in the field reveals what progress has been made in the development of these essential components and identifies where further work may yield benefits in the future

MoS2 Nanosheets Uniformly Anchored on NiMoO4 Nanorods, a Highly Active Hierarchical Nanostructure Catalyst for Oxygen Evolution Reaction and Pseudo-Capacitors

Hierarchical nanostructures have attracted considerable research attention due to their applications in the catalysis field. Herein, we design a versatile hierarchical nanostructure composed of NiMoO4 nanorods surrounded by active MoS2 nanosheets on an interconnected nickel foam substrate. The as-prepared nanostructure exhibits excellent oxygen evolution reaction per-formance, producing a current density of 10 mA cm−2 at an overpotential of 90 mV, in comparison with 220 mV necessary to reach a similar current den-sity for NiMoO4. This behavior originates from the structural/morphological properties of the MoS2 nanosheets, which present numerous surface-active sites and allow good contact with the electrolyte. Besides, the structures can effectively store charges, due to their unique branched network providing accessible active surface area, which facilitates intermediates adsorptions. Particularly, NiMoO4/MoS2 shows a charge capacity of 358 mAhg−1 at a current of 0.5 A g−1 (230 mAhg−1 for NiMoO4), thus suggesting promising applications for charge-storing devices

Guidelines for incorporating scientific knowledge and practice on rare diseases into higher education: neuronal ceroid lipofuscinoses as a model disorder model disorder.

This article addresses the educational issues associated with rare diseases (RD) and in particular the Neuronal Ceroid Lipofuscinoses (NCLs, or CLN diseases) in the curricula of Health Sciences and Professional's Training Programs. Our aim is to develop guidelines for improving scientific knowledge and practice in higher education and continuous learning programs. Rare diseases (RD) are collectively common in the general populationwith 1 in 17 people affected by a RDin their lifetime. Inherited defects in genes involved in metabolism are the commonest group of RD with over 8000 known inborn errors of metabolism. The majority of these diseases are neurodegenerative including the NCLs. Any professional training program on NCL must take into account the medical, social and economic burdens related to RDs. To address these challenges and find solutions to themit is necessary that individuals in the government and administrative authorities, academia, teaching hospitals and medical schools, the pharmaceutical industry, investment community and patient advocacy groups all work together to achieve these goals. The logistical issues of including RD lectures in university curricula and in continuing medical education should reflect its complex nature. To evaluate the state of education in the RD field, a summary should be periodically up dated in order to assess the progress achieved in each country that signed up to the international conventions addressing RD issues in society. It is anticipated that auditing current practice will lead to higher standards and provide a framework for those educators involved in establishing RD teaching programs world-wide.publishedVersio

First-principles study of As interstitials in GaAs: Convergence, relaxation, and formation energy

Convergence of density-functional supercell calculations for defect formation energies, charge transition levels, localized defect state properties, and defect atomic structure and relaxation is investigated using the arsenic split interstitial in GaAs as an example. Supercells containing up to 217 atoms and a variety of {\bf k}-space sampling schemes are considered. It is shown that a good description of the localized defect state dispersion and charge state transition levels requires at least a 217-atom supercell, although the defect structure and atomic relaxations can be well converged in a 65-atom cell. Formation energies are calculated for the As split interstitial, Ga vacancy, and As antisite defects in GaAs, taking into account the dependence upon chemical potential and Fermi energy. It is found that equilibrium concentrations of As interstitials will be much lower than equilibrium concentrations of As antisites in As-rich, $n$-type or semi-insulating GaAs.Comment: 10 pages, 5 figure

Quantitative expression of osteopontin in nasal mucosa of patients with allergic rhinitis: effects of pollen exposure and nasal glucocorticoid treatment

<p>Abstract</p> <p>Background</p> <p>Osteopontin (OPN) is a multifunctional cytokine that has been primarily investigated in Th1 diseases. Recently, it has also been implicated in Th2-mediated allergic diseases, such as asthma. The expression of OPN in allergic rhinitis (AR) is currently unknown, as is the effect of intranasal glucocorticosteroids (GCs) on that expression.</p> <p>Methods</p> <p>Subjects with AR were randomised to receive treatment with fluticasone propionate (FP) (n = 12) or a placebo (n = 16) over the grass pollen season and nasal biopsies were taken prior to, and during the season. OPN expression in the nasal mucosa was examined with immunohistochemistry. Healthy non-AR controls (n = 5) were used as a comparator.</p> <p>Results</p> <p>OPN expression was detected in epithelial cells, subepithelial infiltrating/inflammatory cells and cells lining the vessels and glands of all subjects. Comparison of the pre- and peak-pollen season biopsy sections in placebo treated patients revealed no increase in OPN expression during the grass pollen season (5.7% vs 6.4%). Treatment with a local glucocorticosteroid did not alter the expression of OPN during pollen exposure (6.2% vs 6.7%).</p> <p>Conclusion</p> <p>OPN has been increasingly associated with the pathogenesis of various Th2-mediated diseases. However, our finding that the OPN expression in the nasal mucosa of AR patients is not significantly affected by allergen exposure and is comparable to that of the healthy controls, suggests that intracellular OPN is not directly involved in the pathogenesis of allergic rhinitis.</p