Hartmann's Procedure or Primary Anastomosis?

Perforation following acute diverticulitis is a typical scenario during the first attack. Different classification systems exist to classify acute perforated diverticulitis. While the Hinchey classification, which is based on intraoperative findings, is internationally best known, the German Hansen-Stock classification which is based on CT scan is widely accepted within Germany. When surgery is necessary, sigmoid colectomy is the standard of care. An important question is whether patients should receive primary anastomosis or a Hartmann procedure subsequently. A priori there are several arguments for both procedures. Hartmann's operation is extremely safe and, therefore, represents the best option in severely ill patients and/or extensive peritonitis. However, this operation carries a high risk of stoma nonreversal, or, when reversal is attempted, a high risk in terms of morbidity and mortality. In contrast, primary anastomosis with or without loop ileostoma is a slightly more lengthy procedure as normally the splenic flexure needs to be mobilized and construction of the anastomosis may consume more time than the Hartmann operation. The big advantage of primary anastomosis, however, is that there is no need for the potentially risky stoma reversal operation. The most interesting question is when to do the Hartmann operation or primary anastomosis. Several comparative case series were published showing that primary anastomosis is feasible in many patients. However, no randomized trial is available to date. It is of note, that all non-randomized case series are biased, i.e. that patients in better condition received anastomosis and those with severe peritonitis underwent Hartmann's operation. This bias is undoubtedly likely to be present, even if not obvious, in the published papers! Our own data suggest that this decision should not be based on the extent of peritonitis but rather on patient condition and comorbidity. In conclusion, sigmoid colectomy and primary anastomosis is feasible and safe in many patients who need surgery for perforated diverticulitis, particularly when combined with loop ileostomy. Based on our own published analysis, however, we recommend performing Hartmann's operation in severely ill patients who carry substantial comorbidity, while the extent of peritonitis appears not to be of predominant importance. Copyright (C) 2012 S. Karger AG, Base

Examining Biased Assimilation of Brand-related Online Reviews

This paper examines the impact of pre-existing brand attitudes on consumer processing of electronic word-of-mouth (eWOM). This topic is particularly important for brands that simultaneously possess strongly pronounced proponents as well as opponents. Two experimental studies using univalent (study 1, N = 538) and mixed (study 2, N = 262) sets of online reviews find indications for biased assimilation effects of eWOM processing. Consumers perceive positive (negative) arguments in online reviews as more (less) persuasive when having a positive (negative) attitude towards the brand. Perceived persuasiveness in turn influences behavioral intentions and acts as a mediator on the relationship between attitude and behavioral intentions. We examine two moderators of this effect. When priming individuals to focus on other consumers (vs. a self-focus prime), the biased assimilation effect is weaker (study 3a, N = 131). In contrast, we show that biased assimilation becomes stronger under conditions of high (vs. low) cognitive impairment (study 3b, N = 124). Our findings contribute to the literature on the relationship between eWOM and brands and advance our understanding of potential outcomes of brand polarization

Walks of molecular motors in two and three dimensions

Molecular motors interacting with cytoskeletal filaments undergo peculiar random walks consisting of alternating sequences of directed movements along the filaments and diffusive motion in the surrounding solution. An ensemble of motors is studied which interacts with a single filament in two and three dimensions. The time evolution of the probability distribution for the bound and unbound motors is determined analytically. The diffusion of the motors is strongly enhanced parallel to the filament. The analytical expressions are in excellent agreement with the results of Monte Carlo simulations.Comment: 7 pages, 2 figures, to be published in Europhys. Let

A Microscopic Mechanism for Muscle's Motion

The SIRM (Stochastic Inclined Rods Model) proposed by H. Matsuura and M. Nakano can explain the muscle's motion perfectly, but the intermolecular potential between myosin head and G-actin is too simple and only repulsive potential is considered. In this paper we study the SIRM with different complex potential and discuss the effect of the spring on the system. The calculation results show that the spring, the effective radius of the G-actin and the intermolecular potential play key roles in the motion. The sliding speed is about $4.7\times10^{-6}m/s$ calculated from the model which well agrees with the experimental data.Comment: 9 pages, 6 figure

Actively Contracting Bundles of Polar Filaments

We introduce a phenomenological model to study the properties of bundles of polar filaments which interact via active elements. The stability of the homogeneous state, the attractors of the dynamics in the unstable regime and the tensile stress generated in the bundle are discussed. We find that the interaction of parallel filaments can induce unstable behavior and is responsible for active contraction and tension in the bundle. Interaction between antiparallel filaments leads to filament sorting. Our model could apply to simple contractile structures in cells such as stress fibers.Comment: 4 pages, 4 figures, RevTex, to appear in Phys. Rev. Let

Stakeholder involvement in systematic reviews: a protocol for a systematic review of methods, outcomes and effects

Background There is an expectation for stakeholders (including patients, the public, health professionals, and others) to be involved in research. Researchers are increasingly recognising that it is good practice to involve stakeholders in systematic reviews. There is currently a lack of evidence about (A) how to do this and (B) the effects, or impact, of such involvement. We aim to create a map of the evidence relating to stakeholder involvement in systematic reviews, and use this evidence to address the two points above. Methods We will complete a mixed-method synthesis of the evidence, first completing a scoping review to create a broad map of evidence relating to stakeholder involvement in systematic reviews, and secondly completing two contingent syntheses. We will use a stepwise approach to searching; the initial step will include comprehensive searches of electronic databases, including CENTRAL, AMED, Embase, Medline, Cinahl and other databases, supplemented with pre-defined hand-searching and contacting authors. Two reviewers will undertake each review task (i.e., screening, data extraction) using standard systematic review processes. For the scoping review, we will include any paper, regardless of publication status or study design, which investigates, reports or discusses involvement in a systematic review. Included papers will be summarised within structured tables. Criteria for judging the focus and comprehensiveness of the description of methods of involvement will be applied, informing which papers are included within the two contingent syntheses. Synthesis A will detail the methods that have been used to involve stakeholders in systematic reviews. Papers from the scoping review that are judged to provide an adequate description of methods or approaches will be included. Details of the methods of involvement will be extracted from included papers using pre-defined headings, presented in tables and described narratively. Synthesis B will include studies that explore the effect of stakeholder involvement on the quality, relevance or impact of a systematic review, as identified from the scoping review. Study quality will be appraised, data extracted and synthesised within tables. Discussion This review should help researchers select, improve and evaluate methods of involving stakeholders in systematic reviews. Review findings will contribute to Cochrane training resources

Molecular Motor of Double-Walled Carbon Nanotube Driven by Temperature Variation

An elegant formula for coordinates of carbon atoms in a unit cell of a single-walled nanotube (SWNT) is presented and a new molecular motor of double-walled carbon nanotube whose inner tube is a long (8,4) SWNT and outer tube a short (14,8) SWNT is constructed. The interaction between inner an outer tubes is analytically derived by summing the Lennard-Jones potentials between atoms in inner and outer tubes. It is proved that the molecular motor in a thermal bath exhibits a directional motion with the temperature variation of the bath.Comment: 9 pages, 4 figures, revtex

The gene for trypsin inhibitor CMe is regulated in trans by the lys 3a locus in the endosperm of barley (Hordeum vulgare L.)

A cDNA encoding trypsin inhibitor CMe from barley endosperm has been cloned and characterized. The longest open reading frame of the cloned cDNA codes for a typical signal peptide of 24 residues followed by a sequence which is identical to the known amino acid sequence of the inhibitor, except for an Ile/Leu substitution at position 59. Southern blot analysis of wheat-barley addition lines has shown that chromosome 3H of barley carries the gene for CMe. This protein is present at less than 2%–3% of the wild-type amount in the mature endosperm of the mutant Risø 1508 with respect to Bomi barley, from which it has been derived, and the corresponding steady state levels of the CMe mRNA are about I%. One or two copies of the CMe gene (synonym Itc1) per haploid genome have been estimated both in the wild type and in the mutant, and DNA restriction patterns are identical in both stocks, so neither a change in copy number nor a major rearrangement of the structural gene account for the markedly decreased expression. The mutation at the lys 3a locus in Risø 1508 has been previously mapped in chromosome 7 (synonym 5H). A single dose of the wild-type allele at this locus (Lys 3a) restores the expression of gene CMe (allele CMe-1) in chromosome 3H to normal levels