High performance parallel numerical methods for Volterra equations with weakly singular kernels

Non-stationary discrete time waveform relaxation methods for Abel systems of Volterra integral equations using fractional linear multistep formulae are introduced. Fully parallel discrete waveform relaxation methods having an optimal convergence rate are constructed. A significant expression of the error is proved, which allows us to estimate the number of iterations needed to satisfy a prescribed tolerance and allows us to identify the problems where the optimal methods offer the best performance. The numerical experiments confirm the theoretical expectations

Agar hydrogel with silver nanoparticles to prolong the shelf life of Fior di Latte cheese.

The objective of this work was to evaluate the effectiveness of an antimicrobial packaging system containing active nanoparticles on the quality deterioration of Fior di Latte cheese. To this aim, 3 concentrations of silver montmorillonite embedded in agar were used. The cell loads of spoilage and useful microorganisms were monitored during a refrigerated storage period. Moreover, cheese sensory quality (i.e., odor, color, consistency, and overall quality) was evaluated by means of a panel test. Results showed that the active packaging system markedly increased the shelf life of Fior di Latte cheese, due to the ability of silver cations to control microbial proliferation, without affecting the functional dairy microbiota and the sensory characteristics of the product. The active packaging system developed in this work could be used to prolong the shelf life of Fior di Latte and boost its distribution beyond local market borders

Immobilization of lysozyme on polyvinylalcohol films for active packaging applications.

A new technique for the immobilization of lysozyme onto the surface of polyvinylalcohol films is presented. The active compound was sprayed along with a suitable bonding agent onto the surface of the cross-linked polymeric matrix. Active compound release tests determined the amount of lysozyme immobilized on the film surface. With the use of Micrococcus lysodeikticus, the antimicrobial activity of the films was determined and the results correlated with the amount of immobilized lysozyme. This new technique was effective for immobilizing the enzyme, and the developed films were active against the test microorganism. Results were compared with those obtained with a different immobilizing technique, in which the active compound was bound into the bulk of the polymeric film. As expected, the surface-immobilized lysozyme films have a higher antimicrobial activity than bulk-bound films

Laparoscopic Treatment of Inguinal Ovarian Hernia in Female Infants and Children: Standardizing the Technique

Sliding indirect inguinal hernias containing ovary are not uncommon in girls. We reported our experience with laparoscopic treatment of inguinal ovarian hernias in female infants and children with the aim to standardize the surgical technique. METHODS: The medical records of all girls who underwent laparoscopic inguinal hernia repair in our unit over the past 5 years were retrospectively reviewed. Only patients with an ovary found intraoperatively in the hernia sac were included in the study. All patients younger than 1 year received preoperatively a bowel preparation with simethicone and enemas. RESULTS: A total of 289 girls (median age 3.2 ± 0.5 years) underwent laparoscopic inguinal hernia repair during the study period. Thirty-seven patients (12.8%) had an ovarian hernia and were included in the study. Of these 37 girls, 9 (28.1%) were younger than 1 month, 20 (62.5%) ranged in age from 2 months to 1 year, and 3 (9.4%) were from 1 to 7 years. The average operative time was 23.7 minutes (range 18-43 minutes). No necrotic ovary was found intraoperatively, and all the procedures were accomplished laparoscopically. Neither intraoperative nor postoperative complications were reported. A patency of the contralateral canal of Nuck was found in 16 of the 37 patients (43.2%) and repaired during the same procedure. The average length of hospitalization was 21.8 hours (range 18-36 hours). No hernia recurrence or ovarian atrophy was recorded at a mean follow-up of 36 months (range 1-60 months). CONCLUSIONS: On the basis of our experience, laparoscopy should be considered the gold standard for the treatment of inguinal ovarian hernias in girls. Key points for standardization of the technique are as follows: bowel preparation in children younger than 1 year, use of 5-mm umbilical balloon trocar, correct positioning of 3-mm working screw trocars, section of the abnormal attachment of ovarian suspensory ligament, section of the periorificial peritoneum, and use of nonresorbable sutures

Whole extruded linseed in the diet of dairy ewes during early lactation: effect on the fatty acid composition of milk and cheese

In a long term supplementation trial (10 weeks), the effects of the inclusion of whole extruded linseed in the diet of dairy ewes on milk and cheese fatty acid composition were evaluated. Two groups of 24 Sarda ewes in early lactation were randomly assigned to control concentrate (800 g/d concentrate, C) or whole extruded linseed concentrate (L, 700 g/d, with 30% of extruded linseed, Omega-Lin®). Results showed that, after 2 weeks on the L diet, the milk content of unsaturated fatty acid (UFA), including rumenic acid (RA), vaccenic acid (VA) and alfa-linolenic acid (ALA) increased sharply compared to C group, reaching the highest levels after 7-8 weeks (3.06, 7.31 and 2.31 g/100 g milk fat for RA, VA and ALA, respectively). During the last 2 weeks of the experimental period, when pasture was included in the diet of both groups, the content of the above fatty acids slightly decreased in milk from L group, whereas in milk from C group increased. Nevertheless, the average content of these fatty acids in milk from L group remained significantly higher than that of milk from C group. Compared with the control, the L diet resulted in a significant reduction (-17%) in the concentration of saturated fatty acid in milk. The fatty acid content of the cheese obtained from milk of the two groups reflected the milk fatty acid composition. The inclusion of extruded linseed in the diet of dairy ewes improved the nutraceutical properties of milk and cheese, but further researches are needed in order to better understand the relationship between basal diet and lipid supplementation in dairy ewes

Active systems based on silver-montmorillonite nanoparticles embedded into bio-based polymer matrices for packaging applications.

Silver-montmorillonite (Ag-MMT) antimicrobial nanoparticles were obtained by allowing silver ions from nitrate solutions to replace the Na(+) of natural montmorillonite and to be reduced by thermal treatment. The Ag-MMT nanoparticles were embedded in agar, zein, and poly(ε-caprolactone) polymer matrices. These nanocomposites were tested in vitro with a three-strain cocktail of Pseudomonas spp. to assess antimicrobial effectiveness. The results indicate that Ag-MMT nanoparticles embedded into agar may have antimicrobial activity against selected spoilage microorganisms. No antimicrobial effects were recorded with active zein and poly(ε-caprolactone). The water content of the polymeric matrix was the key parameter associated with antimicrobial effectiveness of this active system intended for food packaging applications

Lentil fortified spaghetti: Technological properties and nutritional characterization

Lentil (Lens culinaris), consumed as a part of the diet worldwide, is a functional dietary ingredient that plays a function in human nutrition as a rich source of bioactive nutrients (low quantities of fat, sodium, and vitamin K; high content of potassium, essential amino acids, insoluble dietary fiber, and polyphenols). In this study spaghetti fortified with lentil flours (40% w/w) were developed and characterized. The addition of two different lentil flours significantly affected the sensory attributes and cooking properties of dry spaghetti. Therefore, the addition of carboxymethyl cellulose was adopted as technological option to improve the quality of fortified pasta; specifically, sensory acceptability, cooking loss, swelling index, and water absorption were studied. Chemical results highlighted that the addition of lentil to semolina significantly increased the content of lysine and threonine. It was observed an increase in essential and branched-chain amino acids. Contrary to what was expected, no increase in mono and polyunsaturated fatty acids was observed in fortified spaghetti, due to their loss during cooking, even after the addition of carboxymethyl cellulose

Pediatric Endoscopic Pilonidal Sinus Treatment: An Effective Procedure for Children with Recurrent Pilonidal Sinus Disease after Failed Open Surgery

Background: The traditional open excision of pilonidal sinus disease (PSD) is associated with a painful postoperative course and high recurrence rates. We recently published our technique of pediatric endoscopic pilonidal sinus treatment (PEPSiT). We aimed to report our long-term outcome including using PEPSiT for recurrent PSD after failed open repair. Methods: All patients with recurrent PSD after open excision who underwent PEPSiT in our unit over the past 2 years were included in the study. During surgery a fistuloscope was introduced through the fistula's orifice. All identifiable hairs were removed using endoscopic forceps. Thereafter, the cavity was debrided with endobrush and ablated with monopolar electrode. External openings were not closed. Results: In the past 2 years, 40 patients with PSD underwent PEPSiT. Ten of 40 patients (6 boys and 4 girls with an average age of 16.8 years [range = 14-18]) had recurrent PSD after open surgery and were included in the study. The average operative time was 27.7 minutes (range = 24-43). No perioperative complications occurred. The average analgesic requirement was 20 hours (range = 16-26) and the average hospitalization was 22.4 hours (range = 18-36). The average time to return to full daily activities was 2.3 days (range = 1-5) and all patients were highly satisfied of postoperative course. At 1 month postoperatively, the external openings were completely healed. No recurrence was recorded at a mean follow-up of 18 months (range = 6-24). Conclusions: Our results demonstrated that PEPSiT is an excellent technique for surgical treatment of PSD in children and teenagers. In fact, it is technically easy and fast to perform, with a short and painless hospital stay and it allows to the operated patients an early return to full daily activities without any physical limitations compared with open repair. In addition, it is also effective for treatment of recurrent PSD after failed open repair

Technical standardization of MIS management of children with pilonidal sinus disease using pediatric endoscopic pilonidal sinus treatment (PEPSiT) and laser epilation

This study aimed to standardize the technique of pediatric endoscopic pilonidal sinus treatment (PEPSiT) associated with laser epilation. METHODS: All pediatric patients presenting with acute or chronic pilonidal sinus disease (PSD) who underwent PEPSiT in our institution over a 36-month period (July 2015-July 2018), were included in the study. Pre- and postoperative management, recurrence rate, postoperative pain, hospital stay, analgesic requirements, and patient satisfaction levels were evaluated. RESULTS: A total of 59 patients (23 girls and 36 boys) underwent PEPSiT during the study period. Ten/59 patients (16.9%) had recurrent PSD after open repair, and 4/59 (6.7%) presented a concomitant pilonidal cyst. All children underwent laser epilation pre- and postoperatively over the last 15 months. The average length of surgery was 27.5 min (range 20-45). The average pain score during the first 48 postoperative hours was 2.7 (range 2-5), and the average analgesic requirement was 20 h (range 16-24). The average hospitalization was 22.4 h (range 18-36). At 1 month postoperatively, external openings were healed in all patients. During follow-up, 1 recurrence (1.6%) was recorded and successfully re-treated with PEPSiT. CONCLUSIONS: We believe that PEPSiT represents the technique of choice for treatment of PSD in the pediatric population. It is crucial to standardize the technique consisting of pre- and postoperative laser epilation, PEPSiT, and accurate postoperative wound management with eosin and sulfadiazine spray

Antimicrobial activity of immobilized lysozyme on plasma-treated polyethylene films.

In this study we tested the antimicrobial activity of polyethylene films modified by means of plasma processes that were followed by the chemical immobilization of lysozyme, an antimicrobial enzyme. To chemically immobilize the enzyme in its active form at the surface of polyethylene, substrates that had been plasma treated under different experimental conditions were soaked in lysozyme solutions at different concentrations. The immobilization of the enzyme was checked, and the antimicrobial activity of the films was investigated by observing the death rate of Micrococcus lysodeikticus cells suspended in phosphate buffer in contact with the films. The results clearly indicate that plasma-treated films loaded with lysozyme are active against the selected microorganism. A modified version of the Gompertz equation was used to quantitatively valuate the dependence of the antimicrobial activity of the films under both plasma treatment conditions and lysozyme concentrations