Molecular Spintronics: Spin-Dependent Electron Transport in Molecular Wires

We present a theoretical study of spin-dependent transport through molecular wires bridging ferromagnetic metal nanocontacts. We extend to magnetic systems a recently proposed model that provides a em quantitative explanation of the conductance measurements of Reed et al. on Au break-junctions bridged by self-assembled molecular monolayers (SAMs) of 1,4-benzene-dithiolate (BDT) molecules. Based on our calculations, we predict that spin-valve behavior should be observable in nickel break-junctions bridged by SAM's formed from BDT. We also consider spin transport in systems consisting of a clean ferromagnetic nickel STM tip and SAMs of benzene-thiol molecules on gold and nickel substrates. We find that spin-valve behavior should be possible for the Ni substrate. For the case where the substrate is gold, we show that it should be possible to inject a highly spin-polarized current into the substrate.Comment: 14 pages, 9 figure

Reduction of apoptosis and preservation of mitochondrial integrity under ischemia/reperfusion injury is mediated by estrogen receptor β

Background Estrogen improves cardiac recovery after ischemia/reperfusion (I/R) by yet incompletely understood mechanisms. Mitochondria play a crucial role in I/R injury through cytochrome c-dependent apoptosis activation. We tested the hypothesis that 17β-estradiol (E2) as well as a specific ERβ agonist improve cardiac recovery through estrogen receptor (ER)β-mediated mechanisms by reducing mitochondria-induced apoptosis and preserving mitochondrial integrity. Methods We randomized ovariectomized C57BL/6N mice 24h before I/R to pre-treatment with E2 or a specific ERβ agonist (ERβA). Isolated hearts were perfused for 20min prior to 30min global ischemia followed by 40min reperfusion. Results Compared with controls, ERβA and E2 treated groups showed a significant improvement in cardiac recovery, i.e. an increase in left ventricular developed pressure, dP/dtmax and dP/dtmin. ERβA and E2 pre- treatment led to a significant reduction in apoptosis with decreased cytochrome c release from the mitochondria and increased mitochondrial levels of anti-apoptotic Bcl2 and ACAA2. Protein levels of mitochondrial translocase inner membrane (TIM23) and mitochondrial complex I of respiratory chain were increased by ERβA and E2 pre-treatment. Furthermore, we found a significant increase of myosin light chain 2 (MLC2) phosphorylation together with ERK1/2 activation in E2, but not in ERβA treated groups. Conclusions Activation of ERβ is essential for the improvement of cardiac recovery after I/R through the inhibition of apoptosis and preservation of mitochondrial integrity and can be a achieved by a specific ERβ agonist. Furthermore, E2 modulates MLC2 activation after I/R independent of ERβ

Share.TEC System Architecture

This paper presents the Share.TEC system architecture and the first system prototype. This description stresses on the main system components and underlying technologies, standards and protocols. The main system functionalities are following logically from the main use cases and user requirements. The system design allows a tight integration between data, which have been automatically harvested from various external repositories, and a representation of the ontology that describes all aspects of the teacher education domain. The proposed implementation relies on modern features such as searching a net of digital objects interconnected by custom-defined relations. A multicultural system which accommodates to the user preferences requires specific user interface. The dynamic approach for presenting the information to the user, based on the teacher education ontology, contributes to the flexibility of the system

Share.TEC Repository System

The Share.TEC system has the main goal to establish a highly visible and functional portal with advanced brokerage services that will provide personalised access to a wide-range of Teacher Education (TE) content. The heart of the Share.TEC system is the central repository, storing metadata about TE resources. In this paper we describe the design of the digital Share.TEC repository, providing the more flexible and powerful ways for representing Common Metadata Model (CMM) metadata records and objects from the Teacher Education Ontology (TEO), and ensuring the most efficient and comprehensive search and reasoning abilities, as the key factors for the success of the Share.TEC project. We describe the data models for representing CMM and TEO, as well as the processes ensuring their correct coexistence

Level of vascular ligation and association with oncological expediency in sigmoid and rectal cancer

Introduction: The techniques and oncology feasibility of high vascular ligation of the inferior mesenteric artery along with their varieties – low tie (LT) and high tie (HT) techniques in left-sided colon and rectal cancer, were described more than 100 years ago by Miles and Moynihan. However, the relationship between the level of vascular ligation and the microperfusion of the proximal anastomosis segment, on the one hand, and the volume and quality of lymphatic dissection, on the other, are the subject of numerous clinical trials and discussions. The vegetative nerve spare in the different approaches is also included in a consideration. Despite the well-established modern standardization in conventional and laparoscopic left colon and rectal cancer surgery, some surgeons still do ligation at the a. rectalis superior level in rectal cancer, which contradicts modern oncology principles.Materials and Methods: Prospective non-randomized comparative cohort study of patients from the Department of Surgery in Alexandrovska University Hospital with cancer of the sigmoid colon or rectum in clinical stage I-III, operated by an open or laparoscopic approach over a 4-year period, stratified into two groups according to the level of ligation of the inferior mesenteric artery (IMA) and vein - high tie - at the site of the origin  (1 cm) from aorta and low tie - distal to the origin of the left colic artery. The comparative indicators included the anastomotic leakage rate, the number of lymph nodes harvested with a metastatic lymph node index, a 3-year disease-free survival (DFS), disease-related survival OS. The follow-up period was 12-48 months.Results: For the period 2014-2018 a total of 217 patients with cancer of the sigmoid colon or rectum underwent 169 laparoscopic and 48 open surgeries. The distribution was as follows: 69% high ligation compared to 31% low ligation; 52 in an emergency or delayed emergency manner; 58% male and 42% female, mean age 64 ± 0.8 years; 56% in clinical stage III, 40% in II and only 4% in clinical stage I, relatively evenly distributed in the two target groups. There were wide variations in the number of lymph nodes harvested from the specimen (n = 4 to 22) for both groups without significant differences in the metastatic index. There was no statistically significant difference in the incidence of anastomotic leaks for both groups (3.8% for HT versus 3.0% for LT). With respect to the 3-year disease-free interval, there were also significant differences - 81.2% (HT) and 79.4% (LT) and the overall survival rate of 79.1% (HT) compared to 77.2% (LT) with a 72% follow-up coefficient.Discussion: The findings of this study are broadly consistent with those published so far and analyzed in three systematic reviews - the last one in 2018. This indicates that no statistically significant difference between high and low vascular ligation has been identified for the most important comparative indicators. It is extremely important to discuss several technical issues at present - contemporary problems requiring future high-quality clinical trials: the necessity and means of implementing left colic flexure mobilization in both types of vascular ligation with the lack of standardization; adequate and accurate identification of a correct cleavage plane of the dissection with differentiation of target vascular areas, avoiding erroneous entry into the sigmoid mesentery along with separate ligation of sigmoid vessels - oncologically inappropriate; sequence and level of ligation of the lower mesenteric vein with wide variations; pathoanatomic processing of the specimen with adequate isolation and examination of the removed lymph nodes, respectively adequacy of the pathohistological N-staging as well as the quality of the mesorectal excision; the need for stage control of the microvascular perfusion of the anastomosis segments by ICG fluorescence on the already validated global methods (hence the prevention of anastomotic leaks); progress in the importance and technical feasibility of low tie vascular ligation + perivascular lymph dissection to the IMA origin, and complete mesocolic excision (CME) in colon carcinoma (similar to TME in the rectal), the subject of more and more current studies; the specifics and advantages of robotic surgery of left-sided colon and rectal cancer with respect to accuracy of vascular and lymphatic dissection

Laser-ion acceleration through controlled surface contamination

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98750/1/PhysPlasmas_18_040702.pd

Individual patient data meta-analysis of organ failure in acute pancreatitis : protocol of the PANCREA II study

Context Organ failure is a major determinant of mortality in patients with acute pancreatitis. These patients usually requireadmission to high dependency or intensive care units and consume considerable health care resources. Given a low incidence rate of organ failure and a lack of large non-interventional studies in the field of acute pancreatitis, the characteristics of organ failure that influence outcomes of patients with acute pancreatitis remain largely unknown. Therefore, the Pancreatitis Across Nations Clinical Research and Education Alliance (PANCREA) aims to conduct a meta-analysis of individual patient data from prospective non-interventional studies to determine the influence of timing, duration, sequence, and combination of different organ failures on mortality in patients with acute pancreatitis. Methods Pancreatologists currently active with acute pancreatitis clinical research will be invited to contribute. To be eligible for inclusion patients will have to meet the criteria of acute pancreatitis, develop at least one organ failure during the first week of hospitalization, and not be enrolled into an intervention study. Raw data will then be collated and checked. Individual patient data analysis based on a logistic regression model with adjustment for confounding variables will be done. For all analyses, corresponding 95% confidence intervals and P values will be reported. Conclusion This collaborative individual patient data meta-analysis will answer important clinical questions regarding patients with acute pancreatitis that develop organ failure. Information derived from this study will be used to optimize routine clinical management and improve care strategies. It can also help validate outcome definitions, allow comparability of results and form a more accurate basis for patient allocation in further clinical studies