Stress Redistribution Near a Crack in Maraging Steel using Composite Patch

The presence of a crack significantly reduces the load bearing capacity of a structure made of fracture prone material. The conventional process of repairing a defect is gouging and filling the gouged location by rewelding. It is not only time consuming but also constrained by the number of repairs that can be done as material properties degrade with each round of rewelding. In an attempt to overcome the limitation of the conventional repair process, repairing a defect using composite patch is proposed. The study is carried out on Maraging steel (M250) and the defect considered is a crack. Stress intensity factor (SIF), being an important parameter in fracture-based design, it is evaluated in Abaqus. Extended finite element method is used to model the crack. SIF is used to predict the failure load of a surface cracked tension specimen and the same is compared with the values reported in literature. Composite patch is modelled using woven ply properties. A separate layer of adhesive is also modelled to predict the properties adhesive properties. Failure analysis of each component namely, the Maraging steel plate, the composite patch and the adhesive is carried.  It was observed that the addition of a composite patch completely nullifies the presence of a crack. The patch with thickness 1mm and woven ply properties is having minimal damage initiation and likely to survive. The adhesive properties required is also obtained from the finite element analysis.  Thus, it was observed that a composite patch with woven ply properties and thickness 1mm is able to completely nullify the effect of a crack when bonded with a suitable adhesive as predicted by the analysis

Pathological significance of heme oxygenase-1 as a potential tumor promoter in heme-induced colorectal carcinogenesis

The significance of the heme-metabolizing enzyme heme oxygenase-1 (HMOX1) in the pathogenesis of colorectal cancer (CRC) has not been fully explored. HMOX1 cytoprotection is imperative to limit oxidative stress. However, its roles in preventing carcinogenesis in response to high levels of heme are not thoroughly understood. This study reviews various mechanisms associated with the paradoxical role of HMOX1, which is advantageous for tumor growth, refractoriness, and survival of cancer cells amid oxidative stress in heme-induced CRC. The alternate role of HMOX1 promotes cell proliferation and metastasis through immune modulation and angiogenesis. Inhibiting HMOX1 has been found to reverse tumor promotion. Thus, HMOX1 acts as a conditional tumor promoter in CRC pathogenesis

Detection of regional DNA methylation using DNA-graphene affinity interactions

We report a new multiplexed strategy for the electrochemical detection of regional DNA methylation across multiple regions. Using the sequence dependent affinity of bisulfite treated DNA towards gold surfaces, the method integrates the high sensitivity of a micro-fabricated multiplex device comprising a microarray of gold electrodes, with the powerful multiplexing capability of multiplex-PCR. The synergy of this combination enables the monitoring of the methylation changes across several genomic regions simultaneously from as low as 500 pg μl(-1) of DNA with no sequencing requirement

Rare landing of Longfin mako shark

Mako sharks are fast-swimming pelagic sharks that migrate through tropical and temperate seas of the world. The shortfin Mako (Isurus oxyrinchus) and longfin Mako (Isurus paucus) are the two species that represent the genus Isurus belonging to Lamnidae family

Research priorities in Maternal, Newborn, & Child Health & Nutrition for India:An Indian Council of Medical Research-INCLEN Initiative

In India, research prioritization in Maternal, Newborn, and Child Health and Nutrition (MNCHN) themes has traditionally involved only a handful of experts mostly from major cities. The Indian Council of Medical Research (ICMR)-INCLEN collaboration undertook a nationwide exercise engaging faculty from 256 institutions to identify top research priorities in the MNCHN themes for 2016-2025. The Child Health and Nutrition Research Initiative method of priority setting was adapted. The context of the exercise was defined by a National Steering Group (NSG) and guided by four Thematic Research Subcommittees. Research ideas were pooled from 498 experts located in different parts of India, iteratively consolidated into research options, scored by 893 experts against five pre-defined criteria (answerability, relevance, equity, investment and innovation) and weighed by a larger reference group. Ranked lists of priorities were generated for each of the four themes at national and three subnational (regional) levels [Empowered Action Group & North-Eastern States, Southern and Western States, & Northern States (including West Bengal)]. Research priorities differed between regions and from overall national priorities. Delivery domain of research which included implementation research constituted about 70 per cent of the top ten research options under all four themes. The results were endorsed in the NSG meeting. There was unanimity that the research priorities should be considered by different governmental and non-governmental agencies for investment with prioritization on implementation research and issues cutting across themes

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

mTOR expression in colorectal adenoma--reply (Correspondence)

"...The mTOR protein expression in colorectal adenomas has not been widely reported in the literature. Our recent study demonstrated no significant difference in mTOR protein expression in adenomas compared to carcinomas of the large intestine [1]. However, mTOR mRNA showed lower expression in colorectal adenomas compared to colorectal adenocarcinomas...

Clinical impacts of mammalian target of rapamycin expression in human colorectal cancers

This study investigated the clinicopathologic roles of mammalian target of rapamycin (mTOR) expression and its relationship to carcinogenesis and tumor progression in a colorectal adenoma-adenocarcinoma model. Two colon cancer cell lines with different pathologic stages (SW480 and SW48) and 1 normal colonic epithelial cell line (FHC) were used, in addition to 119 colorectal adenocarcinomas and 32 adenomas. mTOR expression profiles at messenger RNA (mRNA) and protein levels were investigated in the cells and tissues using real-time quantification polymerase chain reaction and immunohistochemistry. The findings were correlated with the clinicopathologic features of the tumors. The colon cell line from stage III cancer (SW48) showed higher expression of mTOR mRNA than that from stage II cancer (SW480). At the tissue level, mTOR showed higher mRNA and protein expression in colorectal carcinoma than in adenoma. The mRNA and protein expression was correlated with each other in approximately one-third of the carcinomas and adenomas. High levels of mTOR mRNA expression were noted more in carcinoma or adenoma arising from the distal portion of the large intestine (P = .025 and .019, respectively). Within the colorectal cancer population, a high level of expression of mTOR mRNA was related to the presence of lymph node metastases (P = .031), advanced pathologic stage (P = .05), and presence of persistent disease or tumor recurrence (P = .035). To conclude, the study has indicated that mTOR is likely to be involved in the development and progression of colorectal cancer and is linked to cancer initiation, invasiveness, and progression

miR-126 in human cancers: Clinical roles and current perspectives

miR-126 has been implicated in the processes of inflammation and angiogenesis. Through these processes, miR-126 is implicated in cancer biology, but its role there has not been well reviewed. The aim of this review is to examine the molecular mechanisms and clinicopathological significance of miR-126 in human cancers. miR-126 was shown to have roles in cancers of the gastrointestinal tract, genital tracts, breast, thyroid, lung and some other cancers. Its expression was suppressed in most of the cancers studied. The molecular mechanisms that are known to cause aberrant expression of miR-126 include alterations in gene sequence, epigenetic modification and alteration of dicer abundance. miR-126 can inhibit progression of some cancers via negative control of proliferation, migration, invasion, and cell survival. In some instances, however, miR-126 supports cancer progression via promotion of blood vessel formation. Downregulation of miR-126 induces cancer cell proliferation, migration, and invasion via targeting specific oncogenes. Also, reduced levels of miR-126 are a significant predictor of poor survival of patients in many cancers. In addition, miR-126 can alter a multitude of cellular mechanisms in cancer pathogenesis via suppressing gene translation of numerous validated targets such as PI3K, KRAS, EGFL7, CRK, ADAM9, HOXA9, IRS-1, SOX-2, SLC7A5 and VEGF. To conclude, miR-126 is commonly down-regulated in cancer, most likely due to its ability to inhibit cancer cell growth, adhesion, migration, and invasion through suppressing a range of important gene targets. Understanding these mechanisms by which miR-126 is involved with cancer pathogenesis will be useful in the development of therapeutic targets for the management of patients with cancer