136 research outputs found
Synthesis of Bis-4-hydroxycoumarins via a Multi Component Reaction Using Silica Boron-sulfuric Acid Nanoparticles (SBSANs) as an Efficient Heterogeneous Solid Acid Catalyst
The silica boron sulfuric acid nanoparticles (SBSANs) as an efficient heterogeneous solid acid catalyst with both Brønsted and Lewis acidic sites catalyzed the preparation of bis-4-hydroxycoumarin derivatives using reaction of aldehydes and 4-hydroxycoumarin under mild and solvent-free condition at room temperature. This new and efficient methodology has advantages in comparison with currently used methods such as: easy work-up, simple separation of catalyst from the reaction mixture, reusability and lower catalyst loading, relatively short reaction time, eco-friendly with environment, excellent yields, simple purification of products and mild reaction condition. Using this method a range of biologically active bis-4-hydroxycoumarin derivatives were synthesized in good to excellent yield. The catalyst system was reusable at least for 5 times in this reaction without significant decreasing in its catalytic activity
The Actor–Partner Effects of Parenting Stress on Quality of Life Among Parents of Children with ASD: The Mediating Role of Mental Quality of Life
The present study investigated the actor–partner effects of parenting stress (PS) on quality of life (QoL) among parents (96 couples) of children with autism spectrum disorder (ASD). Data were collected using the QoL Scale and the PS Index. Structural equation modeling was also utilized to test the hypothesis. The results revealed the effects of PS in each parent on mental QoL of that parent. Maternal PS further shaped physical QoL in mothers. However, PS in one parent did not influence QoL of his or her partner. Accordingly, mental QoL had a mediating role between PS and physical QoL. It was ultimately suggested to take account of QoL among parents in addition to the treatment of children with ASD
Control Rods Reactivity Worth Measurement in a Mixed Core Heavy Water Zero Power Reactor (HWZPR)
Systems related to reactivity control in a heavy water zero power reactor (HWZPR) consist of safety rod, control rod, emergency dump, and water level measurement and regulation systems. The control rod reactivity worth and safety rods should, therefore, meet the necessary safety criteria. The safety rods are used to shutdown the reactor through rapid falls in the emergency of the reactor and for a normal shutting down condition. According to the safety criteria, the equivalent rod reactivity worth must be appreciably greater than the maximum excess of reactivity which occurs in a reactor. The main applications of the control rods are to control the power rising period and the transition from subcritical to supercritical states. According to the safety guide for a HWZPR when a reactor is close to the critical state, the reactivity insertion rate should not exceed 2×10-4 (∆k/k)/s and the reactivity worth of each control rod should be less than 0.2% ∆k/k to ensure the safety of the reactor operation. According to the obtained calculational and experimental results, these conditions are satisfied for HWZPR. By changing the reactor fuel from natural metal uranium to mixed fuel (natural metal uranium fuel and natural oxide uranium), the control rod reactivity worth is measured and according to the obtained results, the control rod reactivity worth can meet the above provisions
Thermal enhancement effect on chemo-radiation of Glioblastoma multiform
Background: Hyperthermia plays a significant role in the chemo-radiotherapy effect in different malignancies. In this research, we treated Glioblastoma multform (GBM) patents with hyperthermia (HT) along with the chemoradiaton, in order to evaluate HT efficacy in terms of tumor volume changes, survival tme, and probability. Materials and Methods: Thirty-eight GBM patents were distributed into two groups identfied as chemoradiaton (CRT), and also CRT plus HT (CRHT). The Karnofsky Performance Status Scale (KPS) was done before, immediately and three months after treatments. Capacitve hyperthermia device was used at frequency of 13.56 MHz (Celsius 42+ GmbH, Germany) for HT one hour before the radiotherapy for 10-12 sessions. Patents in both groups underwent MR imaging (1.5 Tesla) before, 3 and 6 months after the treatments. Thermal enhancement factors (TEF) were atained in terms of clinical target volume changes, TEF(CTV), and survival probability (SP) or TEF(SP). Results: Age ranges were from 27-73 years (Mean=50) and 27-65 years (Mean=50) for CRT and CRHT groups, respectvely. For 53 and 47 of cases biopsy and partal resecton were accomplished in both groups, respectvely. Means and standard deviatons of tumor volumes were 135.42±92.5 and 58.4±104.1cm3before treatment in CRT and CRHT groups, respectvely, with no significant difference (P= 0.2). TEF(CTV) value was atained to be as 1.54 and 1.70 for three and six months after treatments, respectvely, TEF(SP) was also equal to the 1.90. Conclusion: HT enhanced the chemoradiaton effects throughout the patent survival probability and KPS. TEF may reflect the hyperthermia efficacy for a given radiaton dose. © 2020 Novin Medical Radiation Institute. All rights reserved
Resolved Photon Processes
We review the present level of knowledge of the hadronic structure of the
photon, as revealed in interactions involving quarks and gluons ``in" the
photon. The concept of photon structure functions is introduced in the
description of deep--inelastic scattering, and existing
parametrizations of the parton densities in the photon are reviewed. We then
turn to hard \gamp\ and \gaga\ collisions, where we treat the production of
jets, heavy quarks, hard (direct) photons, \jpsi\ mesons, and lepton pairs. We
also comment on issues that go beyond perturbation theory, including recent
attempts at a comprehensive description of both hard and soft \gamp\ and \gaga\
interactions. We conclude with a list of open problems.Comment: LaTeX with equation.sty, 85 pages, 29 figures (not included). A
complete PS file of the paper, including figures, can be obtained via
anonymous ftp from
ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-898.ps.
First experience with a new negative pressure incision management system on surgical incisions after cardiac surgery in high risk patients
<p>Abstract</p> <p>Background</p> <p>Sternal wound infection remains a serious potential complication after cardiac surgery. A recent development for preventing wound complications after surgery is the adjunctive treatment of closed incisions with negative pressure wound therapy. Suggested mechanisms of preventive action are improving the local blood flow, removing fluids and components in these fluids, helping keep the incision edges together, protecting the wound from external contamination and promoting incision healing. This work reports on our initial evaluation and clinical experience with the Prevena™Incision Management System, a recently introduced new negative pressure wound therapy system specifically developed for treating closed surgical incisions and helping prevent potential complications. We evaluated the new treatment on sternal surgical incisions in patients with multiple co-morbidities and consequently a high risk for wound complications.</p> <p>Methods</p> <p>The Prevena™incision management system was used in 10 patients with a mean Fowler risk score of 15.1 [Range 8-30]. The negative pressure dressing was applied immediately after surgery and left in place for 5 days with a continuous application of -125 mmHg negative pressure. Wounds and surrounding skin were inspected immediately after removal of the Prevena™ incision management system and at day 30 after surgery.</p> <p>Results</p> <p>Wounds and surrounding skin showed complete wound healing with the absence of skin lesions due to the negative pressure after removal of the Prevena™ dressing. No device-related complications were observed. No wound complications occurred in this high risk group of patients until at least 30 days after surgery.</p> <p>Conclusions</p> <p>The Prevena™system appears to be safe, easy to use and may help achieve uncomplicated wound healing in patients at risk of developing wound complications after cardiothoracic surgery.</p
Evaluation of autologous platelet rich plasma for cardiac surgery: outcome analysis of 2000 patients
Theory of hard photoproduction
The present theoretical knowledge about photons and hard photoproduction
processes, i.e. the production of jets, light and heavy hadrons, quarkonia, and
prompt photons in photon-photon and photon-hadron collisions, is reviewed.
Virtual and polarized photons and prompt photon production in hadron collisions
are also discussed. The most important leading and next-to-leading order QCD
results are compiled in analytic form. A large variety of numerical predictions
is compared to data from TRISTAN, LEP, and HERA and extended to future electron
and muon colliders. The sources of all relevant results are collected in a rich
bibliography.Comment: Habilitationsschrift, scheduled for publication in Rev. Mod. Phys.,
126 pages, 61 figure
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