72 research outputs found

    Multipathogen infections in hospitalized children with acute respiratory infections

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    <p>Abstract</p> <p>Background</p> <p>To explore the epidemiologic and clinical features of, and interactions among, multipathogen infections in hospitalized children with acute respiratory tract infection (ARTI). A prospective study of children admitted with ARTI was conducted. Peripheral blood samples were analyzed by indirect immunofluorescence to detect respiratory agents including respiratory syncytial virus; adenovirus; influenza virus (Flu) types A and B; parainfluenza virus (PIV) types 1, 2, and 3; chlamydia pneumonia; and mycoplasma pneumonia. A medical history of each child was taken.</p> <p>Results</p> <p>Respiratory agents were detected in 164 (51.9%) of 316 children with ARTI. A single agent was identified in 50 (15.8%) children, and multiple agents in 114 (36.1%). Flu A was the most frequently detected agent, followed by Flu B. Coinfection occurred predominantly in August and was more frequent in children between 3 and 6 years of age. A significantly higher proportion of Flu A, Flu B, and PIV 1 was detected in samples with two or more pathogens per sample than in samples with a single pathogen.</p> <p>Conclusion</p> <p>Our study suggests that there is a high occurrence of multipathogen infections in children admitted with ARTI and that coinfection is associated with certain pathogens.</p

    Liposomes for systematic delivery of vancomycin hydrochloride to decrease nephrotoxicity: Characterization and evaluation

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    AbstractVancomycin hydrochloride (VANH), the first glycopeptide antibiotic, is a water-soluble drug for the treatment of acute osteomyelitis. Liposomal formulations of VANH have already been manipulated and characterized, which was a mean of increasing their therapeutic index, reducing their toxicity and altering drug biodistribution. One of the challenges for preparing VANH-Lips is their low encapsulation efficiency (EE). In the present study, we aim to improve the liposomal formulation of VANH for higher EE, longer systemic circulation, reduced nephrotoxicity and enhanced antimicrobial activities. Vancomycin hydrochloride-loaded liposomes (VANH-Lips) were formulated by the method of modified reverse phase evaporation. Based on the optimization of formulation with orthogonal experimental design, the average drug encapsulation efficiency and the mean particle size of VANH-Lips were found to be 40.78 ± 2.56% and 188.4 ± 2.77 nm. In vitro drug release of VANH-Lips possessed a sustained release characteristic and their release behavior was in accordance with the Weibull equation. After intravenous injection to mice, the mean residence time (MRT) of VANH-Lips group was significantly prolonged in vivo and the AUC value was improved as well compared with the vancomycin hydrochloride solution (VANH-Sol) group. Furthermore, the biodistribution results in mice showed that VANH-Lips decreased the accumulation of VANH in kidney after intravenous injection. In conclusion, VANH-Lips may be a potential delivery system for VANH to decrease nephrotoxicity in the treatment of osteomyelitis

    Acute Urticaria in Inpatients Undergoing Non-emergent Coronary Angiography With Corticosteroid Prophylaxis: A Retrospective Study

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    Background and Aims: Acute urticaria (AU) is the most frequently reported immediate hypersensitivity reaction in skin by administration of iodinated contrast media (ICM). We aimed to establish the pattern and identify the risk factors of AU among inpatients undergoing non-emergent coronary angiography (CAG) with prophylactic corticosteroids in China.Methods: Medical records of 19,326 adult inpatients undergoing non-emergent CAG with prophylactic methylprednisolone in 2013–2019 were retrospectively investigated. AU was identified within 1 h post-ICM administration, and diffuse involvement was defined when wheals occur in two or more body parts, including the back, abdomen, chest, and extremities. Age- and sex-matched inpatients (1:4) without AU were randomly selected for assessment of risk factors.Results: Approximately 0.8% of CAG inpatients had AU, including 101 diffuse and 64 limited form. The diffuse AU was more common in settings of non-diagnostic CAG, iohexol used, average ICM injection≥3 ml/min, recurrent CAG, and past history of immediate hypersensitivity to ICM. Inpatients with preexisting allergies, decreased evaluated glomerular filtration rate, and increased high sensitivity C reactive protein or neutrophil-to-lymphocyte ratio prior to CAG had a higher probability of AU (odds ratio &gt;1, P &lt; 0.05 for all variables). All AU inpatients complained of pruritus, and mild itching predominated. AU dissipated in several days under treatment of ebastine or levocetirizine 10 mg/daily, but ebastine showed superiority.Conclusions: ICM-induced AU is not uncommon in non-emergent CAG inpatients with prophylactic methylprednisolone. Preexisting allergies, renal dysfunction, and mild inflammation are high-risk factors, and antihistamine monotherapy is a favorable candidate for ICM-related AU

    Nanofluidics and Nanofluids Shape Oscillation of a Single Microbubble in an Ultrasound Field

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    The shape oscillation of a single two-dimensional nitrogen microbubble in an ultrasound field is numerically investigated. The Navier–Stokes equations are solved by using the finite-volume method combined with the volume-of-fluid model. The numerical results are in good accordance with experimental and theoretical results reported. According to the analyses of the shape oscillation process, the bubble deformation period is twice the driving acoustic pressure period and the shape oscillation is mainly caused by the change of interface velocity. The vortexes produced due to velocity variations lead to the deformation of the bubble interface

    Numerical Simulation of Non-Spherical Submicron Particle Acceleration and Focusing in a Converging–Diverging Micronozzle

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    Submicron particles transported by a Laval-type micronozzle are widely used in micro- and nano-electromechanical systems for the aerodynamic scheme of particle acceleration and focusing. In this paper, the Euler–Lagrangian method is utilized to numerically study non-spherical submicron particle diffusion in a converging–diverging micronozzle flow field. The influence of particle density and shape factor on the focusing process is discussed. The numerical simulation shows how submicron particle transporting with varying shape factors and particle density results in different particle velocities, trajectories and focusing in a micronozzle flow field. The particle with a larger shape factor or larger density exhibits a stronger aerodynamic focusing effect in a supersonic flow field through the nozzle. In the intersection process, as the particle size increases, the position of the particle trajectory intersection moves towards the throat at first and then it moves towards the nozzle outlet. Moreover, the influence of the thermophoretic force of the submicron particle on the aerodynamic focusing can be ignored. The results will be beneficial in technological applications, such as micro-thrusters, microfabrication and micro cold spray

    Review of wheel-rail forces measuring technology for railway vehicles

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    In this paper, the research status of three types of wheel-rail interaction force measuring approaches, that is, IWS, ground measurement method and indirect measurement method, are summarized systematically. According to the measuring locations, the IWS can be determined by measuring the bending strain of the axle, as well as the strain of the wheel web. The measuring principle, bridge assembly method, calibration test and sensing technology of IWS are introduced respectively. This paper introduces the ground measurement method of measuring·wheel-rail force by arranging sensors on the rail and other track components to test their response, and the indirect methods for wheel-rail forces measurement are reviewed, which is derived from inertial force and suspension force of wheelset according to the force states of the wheelset. The advantages and disadvantages of the IWS, the ground measurement method and the indirect measurement method are analyzed. The investigation results show that the measuring principle of the IWS is relatively mature, and its measurement accuracy mainly depends on the manufacturing technology, bench calibration and signal acquisition. Future development of the IWS tend to realize the non-destructive, wireless, continuous and accurate measurement of the wheel-rail forces and contact points locations

    Research on the Influence of Wheel Polygonization on Axle Stress

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    To study the influence of wheel polygonization on the dynamic stress of the wheel axle, a vehicle-track rigid-flexible coupling dynamic model was established. In the model, the wheelset, axle box, and track system were modelled as flexible bodies to consider the influence of elastic vibration. At the same time, the dynamic stress on key positions of the axle under the wheel polygonization excitation was measured on the high-frequency vibration test rig. The accuracy of the model was verified by comparison with the test results. The wheel axle stress under the excitation of the wheel polygonization with different orders, wave depths, and running speed was calculated. The results show that the wheel polygonization can increase the amplitude of the axle dynamic stress, and the larger the wave depth of the wheel polygonization, the larger the stress amplitude. When the wheel polygonization frequency is close to the frequency of the wheelset elastic vibration mode, the wheelset first-order bending and second-order bending modes have a great influence on the axle stress. The resonance vibration of the wheelset elastic modal can cause the dynamic stress on key positions of the axle increase sharply

    Association between N-terminal pro-B-type natriuretic peptide and clinical outcomes in bedridden patients with stroke: a cross-sectional study

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    Objectives Patients with stroke often remain bedridden despite rehabilitation. Serum N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels increase after stroke. Our study aimed to investigate the difference in NT-pro-BNP levels between bedridden and non-bedridden patients with stroke and to explore the factors influencing NT-pro-BNP levels in bedridden patients.Design A single-centre, cross-sectional study.Setting This study was conducted in a hospital, Shenzhen, China.Participants Between January 2019 and December 2022, 465 participants were included in this study.Outcome measures The collected data included basic information, laboratory data and echocardiographic parameters. Binary logistic regression analysis and receiver operating characteristic curves were used to identify factors associated with high NT-pro-BNP levels.Results Bedridden patients with stroke had higher levels of NT-pro-BNP, D-dimer, high-sensitivity C reactive protein (hs-CRP) and lower levels of creatinine, high-density lipoprotein cholesterol, albumin and haemoglobin, as well as lower left ventricular ejection fraction, fractional shortening and the ratio between the peak velocities of early and late diastolic filling than non-bedridden patients. In bedridden patients, age ≥75 years, high levels of hs-CRP and creatinine, and low levels of albumin were associated with high NT-pro-BNP levels. In non-bedridden patients, age ≥75 years and high creatinine levels were associated with high NT-pro-BNP levels. In bedridden patients with stroke, the area under the curve (AUC) of hs-CRP was 0.700 (p&lt;0.001, 95% CI 0.638 to 0.762) with a cut-off value of 5.12 mg/L. The AUC of albumin was 0.671 (p&lt;0.001, 95% CI 0.606 to 0.736) with a cut-off value of 37.15 g/L.Conclusions NT-pro-BNP levels were higher in bedridden patients with stroke than in non-bedridden patients. Decreased albumin and elevated hs-CRP levels were associated with high levels of NT-pro-BNP in bedridden patients. Further studies are needed to explore the risk stratification and potential treatments for elevated NT-pro-BNP in bedridden patients with stroke
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