3,481 research outputs found

    Jefferson Medical College and CME: New Challenges, New Opportunities

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    Intermolecular interactions of substituted benzenes on multi-walled carbon nanotubes grafted on HPLC silica microspheres and interaction study through artificial neural networks

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    Purified multi-walled carbon nanotubes (MWCNTs) grafted onto silica microspheres by gamma-radiation were applied as a HPLC stationary phase for investigating the intermolecular interactions between MWCNTs and substituted benzenes. The synthetic route, simple and not requiring CNTs derivatization, involved no alteration of the nanotube original morphology and physical–chemical properties. The affinity of a set of substituted benzenes for the MWCNTs was studied by correlating the capacity factor (k′) of each probe to its physico-chemical characteristics (calculated by Density Functional Theory). The correlation was found through a theoretical approach based on feedforward neural networks. This strategy was adopted because today these calculations are easily affordable for small molecules (like the analytes), and many critical parameters needed are not known. This might increase the applicability of the proposed method to other cases of study. Moreover, it was seen that the normal linear fit does not provide a good model. The interaction on the MWCNT phase was compared to that of an octadecyl (C18) reversed phase, under the same elution conditions. Results from trained neural networks indicated that the main role in the interactions between the analytes and the stationary phases is due to dipole moment, polarizability and LUMO energy. As expected for the C18 stationary phase correlation, is due to dipole moment and polarizability, while for the MWCNT stationary phase primarily to LUMO energy followed by polarizability, evidence for a specific interaction between MWCNTs and analytes. The CNT-based hybrid material proved to be not only a chromatographic phase but also a useful tool to investigate the MWCNT-molecular interactions with variously substituted benzenes

    Efficacy, Safety, and Timing of Anticoagulant Thromboprophylaxis for the Prevention of Venous Thromboembolism in Patients With Acute Spinal Cord Injury: A Systematic Review

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    Study Design: Systematic review. Objectives: The objective of this study was to answer 5 key questions: What is the comparative effectiveness and safety of (1a) anticoagulant thromboprophylaxis compared to no prophylaxis, placebo, or another anticoagulant strategy for preventing deep vein thrombosis (DVT) and pulmonary embolism (PE) after acute spinal cord injury (SCI)? (1b) Mechanical prophylaxis strategies alone or in combination with other strategies for preventing DVT and PE after acute SCI? (1c) Prophylactic inferior vena cava filter insertion alone or in combination with other strategies for preventing DVT and PE after acute SCI? (2) What is the optimal timing to initiate and/or discontinue anticoagulant, mechanical, and/or prophylactic inferior vena cava filter following acute SCI? (3) What is the cost-effectiveness of these treatment options? Methods: A systematic literature search was conducted to identify studies published through February 28, 2015. We sought randomized controlled trials evaluating efficacy and safety of antithrombotic strategies. Strength of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Results: Nine studies satisfied inclusion criteria. We found a trend toward lower risk of DVT in patients treated with enoxaparin. There were no significant differences in rates of DVT, PE, bleeding, and mortality between patients treated with different types of low-molecular-weight heparin or between low-molecular-weight heparin and unfractionated heparin. Combined anticoagulant and mechanical prophylaxis initiated within 72 hours of SCI resulted in lower risk of DVT than treatment commenced after 72 hours of injury. Conclusion: Prophylactic treatments can be used to lower the risk of venous thromboembolic events in patients with acute SCI, without significant increase in risk of bleeding and mortality and should be initiated within 72 hours. © 2017, © The Author(s) 2017

    Određivanje etilnog etera u krvi primjenom plinske kromatografije

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    Les auteurs décrivent une technique de chromatographie gazeuse pour I ‘identification et la détermination quantitative de I\u27éther éthylique dans le sang, frais ou putréfié. En considérant Jas preuves que l\u27on a faites on a constaté une séparation aisée de l\u27éther éthylique de l\u27alcool éthylique et des produits dûs à la putréfaction. A\u27 propos de ces derniers on n\u27a pas rencontré dans les échantillons examinés la présence d\u27alcools supérieurs (butylique, propylique, amylique) signalée pair d\u27autres auteurs.Vršena su određivanja etilnog etera u uzorcima trule krvi primjenom plinske kromatografije u slučajevima kad su klasične metode rada dale prevelike pogreške. Opisana je upotrebljena aparatura i metodika rada. Slika 1. prikazuje kromatogram etera u zraku. Slika 2. daje kromatograme različite koncentracije etera. Slika 3. prikazuje kromatogram za uzorak krvi pokusne životinje koja je tretirana letalnom dozom etilnog etera. Slika 4. je kromatogram trule krvi uz dodatak etilnog etera, a bez tragova etilnog alkohola. Slika 5. dobivena je na isti način, ali uz prisutnost etilnog alkohola. Ukratko se pokazuje značenje plinske kromatografije, naročito za sudsko medicinsku identifikaciju tvari kojih klasična analiza nije jednostavna

    Modified montmorillonite as drug delivery agent for enhancing antibiotic therapy

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    The appealing properties of surfactant‐intercalated Montmorillonites (Organo-montmorillonite, OMt) were successfully investigated to propose an effective drug delivery system for metronidazole (MNE) antibiotic therapy. This represents a serious pharmaceutical concern due to the adverse drug reactions and the low targeting ability of MNE. The non‐ionic surfactant Tween 20 was used to functionalize montmorillonite, thus accomplishing the two‐fold objective of enhancing the stability of clay dispersion and better controlling drug uptake and release. The adsorption process was performed under different experimental conditions and investigated by constructing the adsorption isotherms through high‐performance liquid chromatography (HPLC) measurements. Powder X‐ray diffraction (XRD) measurements were performed to characterize the MNE/OMt compounds. The gathered results revealed that the uptake of the drug occurs preferentially in the clay interlayer, and it is governed by positive cooperative processes. The presence of surfactant drives the adsorption into clay interlayer and hampers the adsorption onto external lamella faces. The good performances of the prepared OMt in the controlled release of the MNE were proved by investigating the release profiles under physiological conditions, simulating oral drug administration. Cytotoxicity measurements demonstrated the biocompatibility of the complexes and evidenced that, under specific experimental conditions, nanodevices are more biocompatible than a free drug

    Application of the Maximum Power Extrapolation Procedure for Human Exposure Assessment to 5G Millimeter Waves: Challenges and Possible Solutions

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    This paper describes an investigation on the application of the Maximum Power Extrapolation (MPE) technique on a fully operational Fixed Wireless Access (FWA) FR2-band 5G gNB. The data was acquired in [27.1-27.3] GHz band using a network scanner over nearly 10 minutes periods to allow a statistical analysis and an accurate estimation of the role of each contribution to the total uncertainty, including the fading affecting the 5G FR2 reference signal. The results show that the level of the electromagnetic field is well below the limits imposed by Italian legislation. However the goal of the paper is more fundamental, and shows an approach that can be used to identify the critical elements of the measurement set-up, suggesting where to concentrate efforts to improve the measurement procedure. In particular, the uncertainty budget highlights three contributions, (i.e. estimation of the traffic beam level, of the probe response and of the 5G FR2 reference signal) that deserve further investigations

    Vinblastine, bleomycin, and methotrexate chemotherapy plus irradiation for patients with early-stage, favorable Hodgkin lymphoma - The experience of the gruppo italiano studio linfomi

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    BACKGROUND. The acknowledged effectiveness of vinblastine, bleomycin, and methotrexate (VBM) chemotherapy in patients with early-stage Hodgkin lymphoma has been associated with conflicting toxicity reports. METHODS. One hundred forty-three patients were evaluated clinically and had favorable Stage IA or IIA Hodgkin lymphoma. Ninety-three patients were treated with the standard VBM schedule combined with extended-field radiotherapy (EFRT), leaving the choice of the therapeutic sequence free. Fifty subsequent patients were treated with a slightly modified VBM schedule (VbMp) combined with RT limited to involved fields (IF-RT) and delivered only after the end of chemotherapy. In the VbMp schedule, intervals between cycles were 21 days instead of 28 days, bleomycin doses were reduced, small doses of prednisone were given orally, and the interval before RT was prolonged. RESULTS. Clinical response was complete in 96% of patients who were treated with VBM plus EF-RT and in 94% of patients who were treated with VbMp plus IF-RT. Recurrence rates were nearly identical (12% and 11%, respectively) over necessarily different follow-up (91 months and 33 months, respectively). Hematologic toxicity was tolerable in both trials, and pulmonary side effects were moderate in the first trial and negligible in the second. On the whole, treatment was tolerated better when RT followed chemotherapy. CONCLUSIONS. The VBM regimen was confirmed to be effective in patients with early-stage Hodgkin lymphoma. Administration of all cycles before RT improved tolerance; pulmonary toxicity probably is mitigated further by reduced bleomycin doses, mild prednisone therapy, and a more prolonged resting interval before RT. A slightly higher recurrence rate was expectable in the VBM plus IF-RT trial despite the actual intensification of vinblastine and methotrexate

    The incidence of deep vein thrombosis detected by routine surveillance ultrasound in neurosurgery patients receiving dual modality prophylaxis.

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    The optimal method of thromboprophylaxis and the value of screening ultrasonography for detection of deep venous thrombosis (DVT) in neurosurgery patients remains unclear. The goal of this study was to determine the incidence of DVT in neurosurgical patients who, by hospital protocol, receive surveillance ultrasonography of the lower extremities twice weekly, in addition to prophylaxis with unfractionated heparin and external pneumatic compression sleeves. A retrospective review of 7,298 ultrasound studies carried out on 2,593 patients over 4 years at a university neurosurgical hospital was conducted. There was a 7.4% incidence of proximal lower extremity DVT and a 9.7% total incidence including distal DVT. A greater number of distal DVTs were detected with the implementation of whole-leg ultrasonography in the last 2 years of observation. Chart review of 237 patients diagnosed with DVT demonstrated an admitting diagnosis of subarachnoid hemorrhage in nearly half of the patients. The median hospital length of stay for DVT patients was 18 days. Institutional control data demonstrated non-ruptured aneurysm and cerebrovascular anomalies to be the leading reason for admission, followed closely by subarachnoid hemorrhage. The hospital protocol of biweekly screening ultrasound and dual modality prophylaxis for neurosurgery patients resulted in a proximal DVT incidence consistent with that demonstrated by previous studies of standardized dual modality prophylaxis, and higher than that demonstrated in previous studies that employed ultrasound screening protocols
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