2,545 research outputs found

    A bizarre foreign body in the appendix: A case report

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    Foreign bodies are rare causes of appendicitis and, in most cases, ingested foreign bodies pass through the alimentary tract asymptomatically. However, ingested foreign bodies may sometimes remain silent within the appendix for many years without an inflammatory response. Despite the fact that cases of foreign-body-induced appendicitis have been documented, sharp and pointed objects are more likely to cause perforations and abscesses, and present more rapidly after ingestion. Various materials, such as needles and drill bits, as well as organic matter, such as seeds, have been implicated as causes of acute appendicitis. Clinical presentation can vary from hours to years. Blunt foreign bodies are more likely to remain dormant for longer periods and cause appendicitis through obstruction of the appendiceal lumen. We herein describe a patient presenting with a foreign body in his appendix which had been swallowed 15 years previously. The contrast between the large size of the foreign body, the long clinical history without symptoms and the total absence of any histological inflammation was notable. We suggest that an elective laparoscopic appendectomy should be offered to such patients as a possible management optio

    The AMS-02 Time of Flight System. Final Design

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    The AMS-02 detector is a superconducting magnetic spectrometer that will operate on the International Space Station. The time of flight (TOF) system of AMS-02 is composed by four scintillator planes with 8, 8, 10, 8 counters each, read at both ends by a total of 144 phototubes. This paper describes the new design, the expected performances, and shows preliminary results of the ion beam test carried on at CERN on October 2002.Comment: 4 pages, 6 EPS figures. Proc. of the 28th ICRC (2003

    Blumgart Anastomosis After Pancreaticoduodenectomy. A Comprehensive Systematic Review, Meta-Analysis, and Meta-Regression

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    Background: The superiority of Blumgart anastomosis (BA) over non-BA duct to mucosa (non-BA DtoM) still remains under debate. Methods: We performed a systematic search of studies comparing BA to non-BA DtoM. The primary endpoint was CR-POPF. Postoperative morbidity and mortality, post-pancreatectomy hemorrhage (PPH), delayed gastric emptying (DGE), reoperation rate, and length of stay (LOS) were evaluated as secondary endpoints. The meta-analysis was carried out using random effect. The results were reported as odds ratio (OR), risk difference (RD), weighted mean difference (WMD), and number needed to treat (NNT). Results: Twelve papers involving 2368 patients: 1075 BA and 1193 non-BA DtoM were included. Regarding the primary endpoint, BA was superior to non-BA DtoM (RD = 0.10; 95% CI: −0.16 to −0.04; NNT = 9). The multivariate ORs' meta-analysis confirmed BA's protective role (OR 0.26; 95% CI: 0.09 to 0.79). BA was superior to DtoM regarding overall morbidity (RD = −0.10; 95% CI: −0.18 to −0.02; NNT = 25), PPH (RD = −0.03; 95% CI −0.06 to −0.01; NNT = 33), and LOS (− 4.2 days; −7.1 to −1.2 95% CI). Conclusion: BA seems to be superior to non-BA DtoM in avoiding CR-POPF

    “Plug and play” modular façade construction system for building renovation to achieve nearly Zero Energy Building (nZEB)

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    Following energy performance improvement policies, there is a need for the massive renovation of the European building stock. The prevalence of multi-rise buildings with concrete structure and poor thermal performance offers a significant opportunity for renovation packages that facilitate the improvement of the building fabric, with its insulation, air-tightness and integration of building services and solar technologies. The RenoZEB project develops a "plug and play" modular facade construction system answering to this need. This prefabricated plug and play modular system has been tested by reproducing the holistic methodology and new technologies in the market by means of real and virtual demonstrators. The applicability and effectiveness of the methodology has been tested by means of a full-scale mock-up system has been constructed and installed in the KUBIK by Tecnalia test facility. The design, construction, manufacture & installation cycle has been tested. Its applicability for a real construction project for a multi-rise residential building in Spain is presented.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 768718

    Galactic secondary positron flux at the Earth

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    Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms of the positron fraction, which exhibits an increase above 10 GeV. Many scenarios have been proposed to explain this feature, among them some additional primary positrons originating from dark matter annihilation in the Galaxy. The PAMELA satellite has provided high quality data that has enabled high accuracy statistical analyses to be made, showing that the increase in the positron fraction extends up to about 100 GeV. It is therefore of paramount importance to constrain theoretically the expected secondary positron flux to interpret the observations in an accurate way. We find the secondary positron flux to be reproduced well by the available observations, and to have theoretical uncertainties that we quantify to be as large as about one order of magnitude. We also discuss the positron fraction issue and find that our predictions may be consistent with the data taken before PAMELA. For PAMELA data, we find that an excess is probably present after considering uncertainties in the positron flux, although its amplitude depends strongly on the assumptions made in relation to the electron flux. By fitting the current electron data, we show that when considering a soft electron spectrum, the amplitude of the excess might be far lower than usually claimed. We provide fresh insights that may help to explain the positron data with or without new physical model ingredients. PAMELA observations and the forthcoming AMS-02 mission will allow stronger constraints to be aplaced on the cosmic--ray transport parameters, and are likely to reduce drastically the theoretical uncertainties.Comment: 15 pages, 12 figures. The recent PAMELA data on the positron fraction (arXiv:0810.4995) have been included and the ensuing discussion has been extended. Accepted version in A&

    Endothelial cell-specific roles for tetrahydrobiopterin in myocardial function, cardiac hypertrophy, and response to myocardial ischemia-reperfusion injury

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    The cofactor tetrahydrobiopterin (BH4) is a critical regulator of nitric oxide synthase (NOS) function and redox signaling, with reduced BH4 implicated in multiple cardiovascular disease states. In the myocardium, augmentation of BH4 levels can impact on cardiomyocyte function, preventing hypertrophy and heart failure. However, the specific role of endothelial cell BH4 biosynthesis in the coronary circulation and its role in cardiac function and the response to ischemia has yet to be elucidated. Endothelial cell-specific Gch1 knockout mice were generated by crossing Gch1fl/fl with Tie2cre mice, generating Gch1fl/flTie2cre mice and littermate controls. GTP cyclohydrolase protein and BH4 levels were reduced in heart tissues from Gch1fl/flTie2cre mice, localized to endothelial cells, with normal cardiomyocyte BH4. Deficiency in coronary endothelial cell BH4 led to NOS uncoupling, decreased NO bioactivity, and increased superoxide and hydrogen peroxide productions in the hearts of Gch1fl/flTie2cre mice. Under physiological conditions, loss of endothelial cell-specific BH4 led to mild cardiac hypertrophy in Gch1fl/flTie2cre hearts. Endothelial cell BH4 loss was also associated with increased neuronal NOS protein, loss of endothelial NOS protein, and increased phospholamban phosphorylation at serine-17 in cardiomyocytes. Loss of cardiac endothelial cell BH4 led to coronary vascular dysfunction, reduced functional recovery, and increased myocardial infarct size following ischemia-reperfusion injury. Taken together, these studies reveal a specific role for endothelial cell Gch1/BH4 biosynthesis in cardiac function and the response to cardiac ischemia-reperfusion injury. Targeting endothelial cell Gch1 and BH4 biosynthesis may provide a novel therapeutic target for the prevention and treatment of cardiac dysfunction and ischemia-reperfusion injury. NEW & NOTEWORTHY We demonstrate a critical role for endothelial cell Gch1/BH4 biosynthesis in coronary vascular function and cardiac function. Loss of cardiac endothelial cell BH4 leads to coronary vascular dysfunction, reduced functional recovery, and increased myocardial infarct size following ischemia/reperfusion injury. Targeting endothelial cell Gch1 and BH4 biosynthesis may provide a novel therapeutic target for the prevention and treatment of cardiac dysfunction, ischemia injury, and heart failure

    Immunotherapy and its development for gynecological (Ovarian, endometrial and cervical) tumors: From immune checkpoint inhibitors to chimeric antigen receptor (car)-T cell therapy

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    Gynecological tumors are malignancies with both high morbidity and mortality. To date, only a few chemotherapeutic agents have shown efficacy against these cancer types (only ovarian cancer responds to several agents, especially platinum-based combinations). Within this context, the discovery of immune checkpoint inhibitors has led to numerous clinical studies being carried out that have also demonstrated their activity in these cancer types. More recently, following the development of chimeric antigen receptor (CAR)-T cell therapy in hematological malignancies, this strategy was also tested in solid tumors, including gynecological cancers. In this article, we focus on the molecular basis of gynecological tumors that makes them potential candidates for immunotherapy. We also provide an overview of the main immunotherapy studies divided by tumor type and report on CAR technology and the studies currently underway in the area of gynecological malignancies

    The Ring Imaging Cherenkov detector (RICH) of the AMS experiment

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    The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the International Space Station (ISS) will be equipped with a proximity focusing Ring Imaging Cherenkov (RICH) detector for measuring the electric charge and velocity of the charged cosmic particles. A RICH prototype consisting of 96 photomultiplier units, including a piece of the conical reflector, was built and its performance evaluated with ion beam data. Preliminary results of the in-beam tests performed with ion fragments resulting from collisions of a 158 GeV/c/nuc primary beam of Indium ions (CERN SPS) on a Pb target are reported. The collected data included tests to the final front-end electronics and to different aerogel radiators. Cherenkov rings for a large range of charged nuclei and with reflected photons were observed. The data analysis confirms the design goals. Charge separation up to Fe and velocity resolution of the order of 0.1% for singly charged particles are obtained.Comment: 29th International Conference on Cosmic Rays (Pune, India

    Improved control strategy of DFIG-based wind turbines using direct torque and direct power control techniques

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    This paper presents different control strategies for a variable-speed wind energy conversion system (WECS), based on a doubly fed induction generator. Direct Torque Control (DTC) with Space-Vector Modulation is used on the rotor side converter. This control method is known to reduce the fluctuations of the torque and flux at low speeds in contrast to the classical DTC, where the frequency of switching is uncontrollable. The reference for torque is obtained from the maximum power point tracking technique of the wind turbine. For the grid-side converter, a fuzzy direct power control is proposed for the control of the instantaneous active and reactive power. Simulation results of the WECS are presented to compare the performance of the proposed and classical control approaches.Peer reviewedFinal Accepted Versio

    Potential Application of Chimeric Antigen Receptor (CAR)-T Cell Therapy in Renal Cell Tumors

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    Currently, renal cell carcinoma is characterized by encouraging benefits from immunotherapy that have led to significant results in treatment outcome. The approval of nivolumab primarily as second-line monotherapy and, more recently, the approval of new combination therapies as first-line treatment have confirmed the importance of immunotherapy in this type of tumor. In this context, the chimeric antigen receptor (CAR)-T represents a further step forward in the field of immunotherapy. Initially tested on hematological malignancies, this new therapeutic approach is also becoming a topic of great interest for solid tumors. Although the treatment has several advantages over previous T-cell receptor-dependent immunotherapy, it is facing some obstacles in solid tumors such as a hostile tumor microenvironment and on-tumor/off-tumor toxicities. Several strategies are under investigation to overcome these problems, but the approval of CAR-T cell therapy is still some way off. In renal cancer, the significant advantages obtained from immune checkpoint inhibitors represent a good starting point, but the potential nephrological toxicity of CAR-T cell therapy represents an important risk. In this review, we provide the rationale and preliminary results of CAR-T cell therapy in renal cell malignancies
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