Frey’s procedure: short term follow up results in terms of pain, endocrine and exocrine status, a tertiary care centre experience

Background: Chronic pancreatitis, a debilitating disease which affects the patient to an extent to render him bedridden sometimes and often make him/her unable to perform daily work, leading to poor quality of life, severe emotional stress and financial burden. Frey’s procedure one of the most commonly performed surgery in patient of chronic pancreatitis with stones in pancreatic duct and small inflammatory head mass. This procedure had shown promising results in terms of pain control with unclear outcome with respect to exocrine and endocrine status.Methods: Study was conducted in Government Kilpauk Medical College, Chennai during March 2016 to December 2019. Total 21 patients were followed up for 18 months and Post-operative pain was analysed using pain scoring system used by Bloechle et al. Exocrine status in terms of diarrhea, bloating sensation and Fecal Elastase level(preoperative and postoperative) were analysed. Patient glycaemic status were also analysed and compared. Patient Nutritional status was analysed in terms of weight gain.Results: In this study there was significant improvement in pain after surgery in terms of VAS pain Score (Preop Mean-82.14, Post-op Mean- 9.76, p<0.001) , frequency of pain (Preop Mean-78.57, Post-op Mean- 14.29, p<0.001), analgesia required (Preop Mean-15, Post-op Mean- 3.10, p<0.001), and inability to work due to pain (Preop Mean-80.95, Post-op Mean- 11.90, p<0.001). Overall total Pain score was significantly improved after surgery (Preop Mean-256.67, Post-op Mean- 39.05, p<0.001). There was significant weight gain and significant improvement in Fecal Elastase level in patients following surgery, however there was no significant difference in pancreatic exocrine status on the basis of symptoms.Conclusions: Frey’s procedure is very effective in pain control in properly selected patients of chronic calcific pancreatitis, and it also improves nutritional status of patient. Frey’s procedure might improve patient exocrine and endocrine status but further  multicentre studies are needed to come to a conclusion.

Mechanisms of passivation and chloride-induced corrosion of mild steel in sulfide-containing alkaline solutions

The pore fluid within many concretes is highly alkaline and rich in reduced sulfur species, but the influence of such alkaline-sulfide solutions on the surface film formed on steel reinforcement is poorly understood. This study investigates the critical role of HS− in defining mild steel passivation chemistry. The surface film formed on the steel in alkaline-sulfide solutions contains Fe(OH)2 and Fe–S complexes, and the critical chloride concentration to induce corrosion increases at high sulfide concentration. However, this behavior is dependent on the duration of exposure of the steel to the electrolyte, and the nature of the sulfidic surface layer

Steel corrosion in reinforced alkali-activated materials

The development of alkali-activated materials (AAMs) as an alternative to Portland cement (PC) has seen significant progress in the past decades. However, there still remains significant uncertainty regarding their long term performance when used in steel-reinforced structures. The durability of AAMs in such applications depends strongly on the corrosion behaviour of the embedded steel reinforcement, and the experimental data in the literature are limited and in some cases inconsistent. This letter elucidates the role of the chemistry of AAMs on the mechanisms governing passivation and chloride-induced corrosion of the steel reinforcement, to bring a better understanding of the durability of AAM structures exposed to chloride. The corrosion of the steel reinforcement in AAMs differs significantly from observations in PC; the onset of pitting (or the chloride ‘threshold’ value) depends strongly on the alkalinity, and the redox environment, of these binders. Classifications or standards used to assess the severity of steel corrosion in PC appear not to be directly applicable to AAMs due to important differences in pore solution chemistry and phase assemblage

Generating and detecting bound entanglement in two-qutrits using a family of indecomposable positive maps

The problem of bound entanglement detection is a challenging aspect of quantum information theory for higher dimensional systems. Here, we propose an indecomposable positive map for two-qutrit systems, which is shown to generate a class of positive partial transposed (PPT) states. A corresponding witness operator is constructed and shown to be weakly optimal and locally implementable. Further, we perform a structural physical approximation of the indecomposable map to make it a completely positive one, and find a new PPT entangled state which is not detectable by certain other well-known entanglement detection criteria.Comment: 9 pages, 3 figures, Comments are welcome

Chloride-induced corrosion of steel rebars in simulated pore solutions of alkali-activated concretes

The passivation and chloride-induced depassivation of steel rebars immersed in varying alkaline environments (0.80 M, 1.12 M and 1.36 M NaOH solutions), simulating the pore solutions of low-Ca alkali-activated concretes, were investigated using a range of electrochemical techniques. The passive film on the steel rebars was complex in chemical makeup, composed of Fe–hydroxides, oxy-hydroxides and oxides. An increased degree of passivation of the rebars was observed when exposed to solutions with higher hydroxide concentrations. The critical chloride level ([Cl⁻]/[OH⁻] ratio) required to induce depassivation of steel was strongly dependent on the alkalinity of the pore solution, and was found to be 0.90, 1.70 and 2.40 for 0.80 M, 1.12 M and 1.36 M NaOH solutions, respectively. These values all correspond to a constant value of [Cl⁻]/[OH⁻]³ = 1.25, which is a novel relationship to predict the onset of pitting, interlinking chloride concentration and the solubility of the passive film

Influence of sulfide on the onset of chloride-induced corrosion of steel reinforcement in alkali-activated slags

In alkali-activated slags (AAS), where ground granulated blast furnace slag is used as the main precursor, the presence of reduced sulfur species yields a highly reducing pore solution environment. This study investigates the influence of sulfide on steel passivation in alkali-activated slag mortars immersed in alkaline (1 M NaOH) and alkaline chloride-rich (1 M NaOH with 5 M NaCl) solutions, and the dependency of chloride-induced pitting on the immersion time and the concentration of sulfide in simulated alkali-activated slag pore solutions (containing 0.80 M OH- and 0 M, 0.01 M and 0.45 M HS-) by means of electrochemical techniques. Surfacesensitive X-ray photoelectron spectroscopic (XPS) and Raman spectroscopic analysis of the corrosion products formed on the steel surfaces, both in alkali-activated slag mortars and in simulated pore solutions, shows that sulfide has a very important influence in altering – but not necessarily in a deleterious way – the characteristics of the steel surface under these conditions

Identification of disease-causing genes using microarray data mining and gene ontology

Background: One of the best and most accurate methods for identifying disease-causing genes is monitoring gene expression values in different samples using microarray technology. One of the shortcomings of microarray data is that they provide a small quantity of samples with respect to the number of genes. This problem reduces the classification accuracy of the methods, so gene selection is essential to improve the predictive accuracy and to identify potential marker genes for a disease. Among numerous existing methods for gene selection, support vector machine-based recursive feature elimination (SVMRFE) has become one of the leading methods, but its performance can be reduced because of the small sample size, noisy data and the fact that the method does not remove redundant genes. Methods: We propose a novel framework for gene selection which uses the advantageous features of conventional methods and addresses their weaknesses. In fact, we have combined the Fisher method and SVMRFE to utilize the advantages of a filtering method as well as an embedded method. Furthermore, we have added a redundancy reduction stage to address the weakness of the Fisher method and SVMRFE. In addition to gene expression values, the proposed method uses Gene Ontology which is a reliable source of information on genes. The use of Gene Ontology can compensate, in part, for the limitations of microarrays, such as having a small number of samples and erroneous measurement results. Results: The proposed method has been applied to colon, Diffuse Large B-Cell Lymphoma (DLBCL) and prostate cancer datasets. The empirical results show that our method has improved classification performance in terms of accuracy, sensitivity and specificity. In addition, the study of the molecular function of selected genes strengthened the hypothesis that these genes are involved in the process of cancer growth. Conclusions: The proposed method addresses the weakness of conventional methods by adding a redundancy reduction stage and utilizing Gene Ontology information. It predicts marker genes for colon, DLBCL and prostate cancer with a high accuracy. The predictions made in this study can serve as a list of candidates for subsequent wet-lab verification and might help in the search for a cure for cancers

Factors controlling carbonation resistance of alkali-activated materials

Although notable advances have been made in recent years in elucidating the relationship between the nature of the precursor and the activation conditions used for production of alkali-activated materials (AAMs), it remains largely unknown whether these materials can withstand various environmental threats during their service life. The interaction between a cementitious material and the CO2 present in the air is referred to as carbonation, and while this is largely a well understood phenomenon for portland cement systems, its long-term effects in AAMs are unknown. This is a consequence of the large number of variables controlling microstructural development and therefore macro-scale properties of AAMs, and the lack of standardized methodologies for testing their carbonation resistance. This study reports an overview of recently identified factors inducing microstructural changes in AAMs upon exposure to CO2, and the influence of carbonation on the corrosion resistance of some steel reinforced AAMs

Plasma total cell-free DNA (cfDNA) is a surrogate biomarker for tumour burden and a prognostic biomarker for survival in metastatic melanoma patients

Introduction Tumour burden is a prognostic biomarker in metastatic melanoma. However, tumour burden is difficult to measure and there are currently no reliable surrogate biomarkers to easily and reliably determine it. The aim of this study was to assess the potential of plasma total cell free DNA as biomarker of tumour burden and prognosis in metastatic melanoma patients. Materials and methods A prospective biomarker cohort study for total plasma circulating cell-free DNA (cfDNA) concentration was performed in 43 metastatic melanoma patients. For 38 patients, paired blood collections and scan assessments were available before treatment and at first response evaluation. Tumour burden was calculated as the sum of volumes from three-dimensional radiological measurements of all metastatic lesions in individual patients. Results Baseline cfDNA concentration correlated with pre-treatment tumour burden (ρ = 0.52, P < 0.001). Baseline cfDNA levels correlated significantly with hazard of death and overall survival, and a cut off value of 89 pg/μl identified two distinct prognostic groups (HR = 2.22 for high cfDNA, P = 0.004). Patients with cfDNA ≥89 pg/μl had shorter OS (10.0 versus 22.7 months, P = 0.009; HR = 2.22 for high cfDNA, P = 0.004) and the significance was maintained when compared with lactic dehydrogenase (LDH) in a multivariate analysis. We also found a correlation between the changes of cfDNA and treatment-related changes in tumour burden (ρ = 0.49, P = 0.002). In addition, the ratio between baseline cfDNA and tumour burden was prognostic (HR = 2.7 for cfDNA/tumour volume ≥8 pg/(μl*cm3), P = 0.024). Conclusions We have demonstrated that cfDNA is a surrogate marker of tumour burden in metastatic melanoma patients, and that it is prognostic for overall survival.Fil: Valpione, S.. University of Manchester; Reino Unido. Christie NHS Foundation Trust; Reino UnidoFil: Gremel, G.. University of Manchester; Reino UnidoFil: Mundra, P.. University of Manchester; Reino UnidoFil: Middlehurst, P.. University of Manchester; Reino UnidoFil: Galvani, E.. Christie NHS Foundation Trust; Reino Unido. University of Manchester; Reino UnidoFil: Girotti, Maria Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. University of Manchester; Reino UnidoFil: Lee, R.J.. University of Manchester; Reino UnidoFil: Garner, G.. University of Manchester; Reino UnidoFil: Dhomen, N.. University of Manchester; Reino UnidoFil: Lorigan, P.C.. Christie NHS Foundation Trust; Reino UnidoFil: Marais, R.. University of Manchester; Reino Unid