© Springer-Verlag Berlin Heidelberg 1995 Softcover reprint of the hardcover I st edition 1995The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.Typesetting: Macmillan India Ltd, Bangalore-25 SPIN: 10069941 54/3140/SPS -5 432 I 0 -Printed on acid-free paper PrefaceThe electron, positron, and positronium (Ps, the electron-positron bound state) are the only light particles which participate in normal low-energy processes of physics and chemistry. Because of their small masses quantum mechanical phenomena play a great role in their behavior. Good accounts of the excess electron behavior are available. Similarly, several good books treat the behavior of the positron in solid state and gas physics. However, the research on the positron and Ps in chemistry-oriented fields of science is not well treated in the literature. In liquids Ps is normally in the "bubble" state, and hence, its chemical reactions are very exceptional, indeed. The states and reactions of the positron in insulating liquids can profitably be compared to those of the only other charged light particle, the excess electron. Furthermore, Ps is formed by a reaction between the positron and excess electron in the positron spur, and Ps formation studies give, therefore, information on excess electrons, too. Consequently, to understand "light particle chemistry" it is necessary to have a good understanding of the chemistry of the positron and Ps. This book is a critical review of the research on the behavior of the positron and Ps performed within chemistry-oriented positron annihilation. In particular, I have emphasized the interpretation of selected, typical, experimental results in the field. The book does not give an exhaustive discussion of all the published results. This is impossible because of lack of space anyway. Discussions of experimental results and theoretical explanations believed to be outdated, erratic, or misleading are mainly omitted, with the exceptions of those which have been used extensively in the literature. The omission of certain works might just indicate that the accepted ideas and concepts in the field have changed very much recently.Partly because of lack of space positron annihilation in several fields on the borderline of chemistry, physics, and/or materials science is not discussed. For example, research on metals, semiconductors, ionic crystals, ceramic materials, high Tc superconductors, gases, and liquid noble gases is not discussed, except if the results are of general interest.The writing of this book would have been impossible without many years of very good collaboration with M. Eldrup and N.J. Pedersen at Risoe. Furthermore, I spent seven months doing fruitful work at IMFUFA, Roskilde University VI Preface
BackgroundPostoperative wound complications are common following surgical procedures. Negative‐pressure wound therapy (NPWT) is well recognized for the management of open wounds and has been applied recently to closed surgical incisions. The evidence base to support this intervention is limited. The aim of this study was to assess whether NPWT reduces postoperative wound complications when applied to closed surgical incisions.MethodsThis was a systematic review and meta‐analysis of randomized clinical trials of NPWT compared with standard postoperative dressings on closed surgical incisions.ResultsTen studies met the inclusion criteria, reporting on 1311 incisions in 1089 patients. NPWT was associated with a significant reduction in wound infection (relative risk (RR) 0·54, 95 per cent c.i. 0·33 to 0·89) and seroma formation (RR 0·48, 0·27 to 0·84) compared with standard care. The reduction in wound dehiscence was not significant. The numbers needed to treat were three (seroma), 17 (dehiscence) and 25 (infection). Methodological heterogeneity across studies led to downgrading of the quality of evidence to moderate for infection and seroma, and low for dehiscence.ConclusionCompared with standard postoperative dressings, NPWT significantly reduced the rate of wound infection and seroma when applied to closed surgical wounds. Heterogeneity between the included studies means that no general recommendations can be made yet.
A new model of positronium (Ps) formation is proposed. Positronium is assumed to be formed by a reaction between a positron and an electron in the positron spur. Ps formation must compete with electron-ion recombination and electron or positron reactions with solvent molecules and scavenger impurities. It is also influenced by electron and positron solvation. The model correlates the measured Ps formation probabilities with the spur electron properties determined in radiation chemistry. The predictions of the model are shown to be in good agreement with experimental results for liquids and solids.
Pregnancy rate was found to be lower and miscarriage rate higher after UAE than after myomectomy. However, we found very low quality of evidence regarding the assessed outcomes and the reported proportions are uncertain. There is a need for improved prospective randomized studies to improve the evidence base. Systematic review registration number: CRD42016036661.
RCT: prophylactic incisional NPWT versus standard dressings postcaesarean in 876 women significantly reduces the risk of SSI.
Suppression of immune reactivity by increased expression of co-inhibitory receptors has been discussed as a major reason as to why the immune system fails to control tumor development. Elucidating the co-inhibitory expression pattern of tumor-infiltrating lymphocytes in different cancer types will help to develop future treatment strategies. We characterized markers reflecting and affecting T-cell functionality by flow cytometry on lymphocytes isolated from blood, ascites and tumor from advanced ovarian cancer patients (n = 35). Significantly higher proportions of CD4+ and CD8+ T-cells expressed co-inhibitory receptors LAG-3, PD-1 and TIM-3 in tumor and ascites compared to blood. Co-expression was predominantly observed among intratumoral CD8+ T-cells and the most common combination was PD-1 and TIM-3. Analysis of 26 soluble factors revealed highest concentrations of IP-10 and MCP-1 in both ascites and tumor. Correlating these results with clinical outcome revealed the proportion of CD8+ T-cells without expression of LAG-3, PD-1 and TIM-3 to be beneficial for overall survival. In total we identified eight immune-related risk factors associated with reduced survival. Ex vivo activation showed tumor-derived CD4+ and CD8+ T-cells to be functionally active, assessed by the production of IFN-γ, IL-2, TNF-α, IL-17 and CD107a. Blocking the PD-1 receptor resulted in significantly increased release of IFN-γ suggesting potential reinvigoration. The ovarian tumor environment exhibits an inflammatory milieu with abundant presence of infiltrating immune cells expressing inhibitory checkpoints. Importantly, we found subsets of CD8+ T-cells with double and triple expression of co-inhibitory receptors, supporting the need for multiple checkpoint-targeting agents to overcome T-cell dysfunction in ovarian cancer.
Pregnant women with obesity may experience prejudice from healthcare professionals. These women felt they were treated with a lack of respect, an accusatorial response, and the feeling that information which could have been helpful was not forthcoming. Communication between obese pregnant woman and healthcare professionals appears to be lacking. Improved training in communication skills, less judgemental behaviour and better dissemination of information from healthcare professionals working with pregnant women with obesity are needed.
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