565 research outputs found
Transformed implicit-explicit DIMSIMs with strong stability preserving explicit part
For many systems of differential equations modeling problems in science and
engineering, there are often natural splittings of the right hand side into two
parts, one of which is non-stiff or mildly stiff, and the other part is stiff.
Such systems can be efficiently treated by a class of implicit-explicit (IMEX)
diagonally implicit multistage integration methods (DIMSIMs), where the stiff
part is integrated by implicit formula, and the non-stiff part is integrated by
an explicit formula. We will construct methods where the explicit part has
strong stability preserving (SSP) property, and the implicit part of the method
is -, or -stable. We will also investigate stability of these methods
when the implicit and explicit parts interact with each other. To be more
precise, we will monitor the size of the region of absolute stability of the
IMEX scheme, assuming that the implicit part of the method is -, or
-stable. Finally we furnish examples of SSP IMEX DIMSIMs up to the order
four with good stability properties
Natural Volterra Runge-Kutta methods
A very general class of Runge-Kutta methods for Volterra integral equations of the second kind is analyzed. Order and stage order conditions are derived for methods of order p and stage order q = p up to the order four. We also investigate stability properties of these methods with respect to the basic and the convolution test equations. The systematic search for A- and V0-stable methods is described and examples of highly stable methods are presented up to the order p = 4 and stage order q = 4
Whey fermented by using Lactobacillus plantarum strains: A promising approach to increase the shelf life of pita bread
Nowadays, there is an increasing concern regarding the shelf life of food products, leading producers to research natural antimicrobial agents to use in food preparation. In this study, we evaluated the antifungal activity of Lactobacillus plantarum fermented whey and then added the whey during preparation of pita bread to study shelf-life improvement. The fermented whey showed a satisfactory inhibitory (antifungal) effect against Penicillium expansum and Penicillium brevicompactum strains: the minimum inhibitory and minimum fungicidal concentrations ranged from 3.9 to 39.0 g/L and from 62.5 to 250 g/L, respectively. Addition of fermented whey increased the shelf life of the pita bread. After inoculation of the bread surface with Penicillium, an increase in shelf life until d 8 was achieved compared with the positive control, whereas under natural contamination conditions, an extension of shelf life until d 19 was observed. In terms of antimicrobial activity, the greatest reduction (100%) in fungal growth was achieved when all of the water in the dough was replaced with fermented whey. An untrained sensory panel could not identify differences between bread produced with fermented whey and control pita breads. These results suggest the possibility of using fermented whey in food preservation
Refining diagnosis and management of chronic venous disease: Outcomes of a modified Delphi consensus process
Abstract Chronic venous disease (CVD) is a common condition with major health consequences that is associated with poor long-term prognosis, significant socioeconomic impact, disabling symptoms and reduced quality of life. To provide practical guidance for diagnosis and management of CVD, a Delphi panel of 5 experts in steering committee and 28 angiologists/vascular surgeons met with the major aim of providing a supplement for established national and international guidelines. A total of 24 statements were voted upon in two rounds, of which consensus was reached on 22 statements, indicating a high level of overall agreement. Consensus was reached on 7 of 8 statements relative to diagnosis (CEAP classification, diagnostic tools, QoL assessment, diagnostic imaging) and on 15 of 16 statements on management (conservative treatments, compressive therapy, pharmacological therapy, surgical treatment). The results of the consensus reached are discussed herein from which it is clear that diagnostic and management approaches utilising personalised therapies tailored to the individual patient should be favoured. While it is clear that additional studies are needed on many aspects of diagnosis and management of CVD, the present Delphi survey provides some key recommendations for clinicians treating CVD that may be useful in daily practice
Efficacy of Narrowband UVB Phototherapy in Erythema Dyschromicum Perstans Treatment: Case Reports
No abstract availabl
Outcomes after non-cardiac surgery: Mortality, complications, disability, and rehospitalization
In the last 25 years, the number of patients aged ≥75 years undergoing non-cardiac surgery has greatly increased. In elderly patients, frailty is significantly associated with an increased risk of adverse events, functional decline, procedural complications, prolonged hospitalization, and mortality. The relationship between frailty and increased mortality and morbidity requires an appropriate tool of assessment to accurately quantify the patient's clinical and perioperative conditions. The preoperative evaluation of elderly patients candidate for non-cardiac surgery should include assessment of frailty, sarcopenia and malnutrition, as these are related to high surgical risk. For colon-rectal surgery as also for gastric cancer surgery, especially early gastric cancer, the introduction of laparoscopy has yielded considerable benefits in terms of short-term postsurgical outcomes, e.g. lower rate of intraprocedural bleeding and reduced length of hospital stay. Despite the progress made in preoperative assessment, surgical procedures and postoperative management, the improvement of outcomes after non-cardiac surgery in elderly patients remains a challenge and calls for future, well-designed clinical studies.</p
Langerhans' cell histiocytosis of the vulva: The use of photodynamic therapy
Background: The evaluation of possible efficacy of Photodynamic Therapy (PDT) in a rare condition of vulvar Langerhans' cell histiocytosis (LCH), in a 43-years-old women with one year history of pruritic vulvar lesions. Main observations: After a cycle of 5 sessions of PDT, with aminolevulinic acid (ALA) in low percentage (5%), the patient reported an improvement of lesions, and an high improvement of local symptoms, with a significant reduction of itch and pain. Conclusions: Our case confirms this single experience of literature for the treatment of vulvar LCH by PDT, with an improvement of disease's symptoms, and can suggest the use of PDT for this rare and untreated disease
Assessment of the Combined Efficacy of Needling and the Use of Silicone Gel in the Treatment of C-Section and Other Surgical Hypertrophic Scars and Keloids
OBJECTIVE:
To evaluate the individual effectiveness of needling therapy using the Dermapen (Dermapen, Salt Lake City, Utah) and topical therapy with silicone gel (Kelo-cote, Sinclair Pharma, London, England), and their combined effectiveness for the treatment of linear surgical scars, hypertrophic scars, and keloids.
MATERIALS AND METHODS:
Twenty patients were randomly selected and equally divided into 2 groups (A and B), with each group of 10 including 6 patients with keloids and 4 with hypertrophic scars. Treatment assignments were random. In group A, the entire scar was treated by skin needling, with silicone gel applied to half of the scar. Patients in group B were treated with silicone gel on the whole scar, with only half of the scar also treated with skin needling. During follow-up visits, clinical photographs, evaluation of the scars' thickness, skin ultrasound, and modified Vancouver Scar Scale were performed.
RESULTS:
Group A showed an average improvement of 68% (P < .01) on the half of the scar with the combination treatment (skin needling plus silicone gel) compared with a 52% improvement on the half of the scar that was treated with only skin needling. Group B showed an average improvement of 63% (P < .01) where the combination treatment was performed, compared with 47% improvement on the area treated with only the silicone gel.
CONCLUSIONS:
In conclusion, the combination of these 2 treatments is safe and effective for the treatment of hypertrophic scars and keloids. These modalities achieved favorable results with each patient adhering to the study paramenters
Synchronous liver and peritoneal metastases from colorectal cancer: Is cytoreductive surgery and hyperthermic intraperitoneal chemotherapy combined with liver resection a feasible option?
BackgroundTraditionally, synchronous liver resection (LR), cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy for colorectal liver and peritoneal metastases have been contraindicated. Nowadays, clinical practice has promoted this aggressive treatment in selected cases. This study aimed to review surgical and survival results of an extensive surgical approach including CRS with hyperthermic intraperitoneal chemotherapy (HIPEC) and LR. MethodsPubMed, EMBASE, and Web of Science databases were matched to find the available literature on this topic. The search period was limited to 10 years (January 2010-January 2021). A threshold of case series of 10 patients or more was applied. ResultsIn the search period, out of 114 studies found about liver and peritoneal metastases from colorectal cancer, we found 18 papers matching the inclusion criteria. Higher morbidity and mortality were reported for patients who underwent such an extensive surgical approach when compared with patients who underwent only cytoreductive surgery and HIPEC. Also, survival rates seem worse in the former than in the latter. ConclusionThe role of combined surgical strategy in patients with synchronous liver and peritoneal metastases from colorectal cancer remains controversial. Survival rates and morbidity and mortality seem not in favor of this option. A more accurate selection of patients and more restrictive surgical indications could perhaps help improve results in this subgroup of patients with limited curative options
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