Sturm Liouville Problem with Moving Discontinuity Points

In this paper, we present a new discontinuous Sturm Liouville problem with symmetrically located discontinuities which are defined depending on a neighborhood of a midpoint of the interval. Also the problem contains an eigenparameter in one of the boundary conditions and has coupled transmission conditions at the discontinuity points. We investigate the properties of the eigenvalues, obtain asymptotic formulas for the eigenvalues and the corresponding eigenfunctions and construct Green's function of this problem.Comment: 19 pages. arXiv admin note: text overlap with arXiv:1210.4350 by other author

Sampling Theorems for Sturm Liouville Problem with Moving Discontinuity Points

In this paper, we investigate the sampling analysis for a new Sturm-Liouville problem with symmetrically located discontinuities which are defined to depending on a neighborhood of a midpoint of the interval. Also the problem has transmission conditions at these points of discontinuity and includes an eigenparameter in a boundary condition. We establish briefly the needed relations for the derivations of the sampling theorems and construct Green's function for the problem. Then we derive sampling representations for transforms whose kernels are either solutions or Green's functions.Comment: 11 page

Eigenvalue Problem with Moving Discontinuity Points

In this paper, we present a Sturm Liouville problem which has discontinuities in the neighborhood of the midpoint of an interval. Also the problem contains an eigenparameter in one of the boundary conditions. We derive operator theoretic formulation in suitable Hilbert space, give some properties of the eigenvalues and obtain asymptotic formulas for the eigenvalues and the corresponding eigenfunctions

Inhibition of protein glycation and advanced glycation end products by ascorbic acid

Advanced glycation end products (AGEs) formation is increased in diabetes mellitus, leading to microvascular and macrovascular complications. Recently, much attention has been focused on natural and synthetic inhibitors to delay the onset or progression of diabetes and its comorbidities. Ascorbic acid (AA) can react with proteins, including hemoglobin and possibly interfere with protein glycation process. An in vitro glycation model containing plasma from type 2 diabetic and non-diabetic healthy volunteers together with glucose as glycating agent was used to study antiglycation activity of AA. Samples with different concentrations of glucose and AA were incubated for five weeks at 37°C. Nonenzymatic glycation (NEG) was quantitated by thiobarbituric acid calorimetry and AGEs were measured by enzyme linked immuno-sorbent assay (ELISA). The NEG and AGEs levels were reduced by AA. Increasing the AA concentrations greatly diminished protein glycations, indicating dose-dependent effects of AA. Plasma NEG and AGEs were decreased with an average of 20 to 26% (p < 0.05) and 26 to 28% (p < 0.05). A significant correlation was found between the glycation inhibition and the inhibition of AGE formation (p < 0.05). The antiglycation role of AA is evident in the present study and it also indicates the possibility of inexpensive, relatively non-toxic vitamin therapy for the prevention and treatment of diabetic complications. It is plausible that AGEs inhibition by AA may also form the basis for future intervention strategies in both diabetic and non-diabetic individuals.Keywords: Diabetes mellitus, glycation, advanced glycation end products, hyperglycemia, ascorbic aci

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Clinical evaluation of muscle functions in neurofibromatosis type 1

Aim Muscle weakness, fatigue and speech problems can occur in neurofibromatosis type 1 (NF1). The pathogenesis of these symptoms is unclear, likely multifactorial. We examined motor function in limb and speech muscles in NF1 patients. Methods We evaluated NF1 and control groups aged 4-18 years for muscle strength, tone and mobility using standard manual testing, joint motion and Beighton score measurements. Speech and language functions were assessed by speech articulation and resonance. As a marker of muscle tissue turnover, we determined collagen degradation products in urine before and after submaximal exercise. Results NF1 patients had reduced strength in proximal limb muscles compared to control subjects. Speech articulation problems and hypernasality were more common in NF1 (47% and 38%, respectively). Collagen products excreted in urine correlated with gluteal and biceps muscle strength. Conclusion Muscle dysfunction can be detected in some children with NF1 and may explain certain clinical features including fatigue, speech and articulation problems. If confirmed by further research, these findings may be relevant to the management of this condition