757 research outputs found

    End reflections in a layered piezoelectric circular cylinder

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    AbstractEnd reflection phenomenon in a semi-infinitely long layered piezoelectric circular cylinder is constructed with modal data from a spectral decomposition of the differential operator governing its natural vibrations. These modal data consist of all propagating modes and edge vibrations and they constitute the basis for a wave function expansion of the reflection of waves arriving at the traction-free end of the cylinder. Without any other external stimulus, a passive reflection event occurs. This traction-free end condition is enforced at the Gaussian integration points over the end cross-section on the combination of incoming and reflected wave fields. Reflections due to monochromatic incoming axisymmetric (m=0) and flexural (m=1) waves are studied and two numerical examples are presented.For an incoming axisymmetric wave, there is a particular frequency that induces an end resonance, which is characterized by high (but finite) amplitudes of end displacements vis-a-vis those of neighboring (i.e., slightly different) frequencies. This phenomenon is illustrated in the two cylinder examples.It is possible to modify the passive reflection event by imposing some voltage distribution over the free end. For an oscillating end voltage that is out-of-phase with the incoming wave, it is possible to extract electrical energy from it, i.e., energy harvesting. Examples of such an oscillating voltage with a particular radial distribution are given, that illustrate the amount of extracted energy as a function of the frequency of the incident monochromatic wave

    Growth and production of Nile tilapia (Oreochromis niloticus Lin.) in irrigated Boro rice under floodplain environment

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    The experiment was conducted at BRRI Regional Station, Habiganj during 1994-95 to evaluate the growth and economic performance of Nile tilapia, Oreochromis niloticus, fish reared in the field of irrigated boro rice with different fertilizer levels. Grain yield of rice was not affected by fish culture. It was observed that 50% of recommended fertilizer was enough to produce increased rice yield (8-10 t/ha) at floodplain environment and additional yield was obtained with the increasing fertilizer rates. Results further indicated that O. niloticus could successfully be reared in the field of irrigated boro rice with recommended fertilizer level. Larger size of fingerlings at release had improved recovery percent, body weight gain and higher fish yield. Results also revealed that rice + fish production system produced higher net return than the system with rice alone

    Electrospinning of Chitosan-Based Solutions for Tissue Engineering and Regenerative Medicine

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    Electrospinning has been used for decades to generate nano-fibres via an electrically charged jet of polymer solution. This process is established on a spinning technique, using electrostatic forces to produce fine fibres from polymer solutions. Amongst, the electrospinning of available biopolymers (silk, cellulose, collagen, gelatine and hyaluronic acid), chitosan (CH) has shown a favourable outcome for tissue regeneration applications. The aim of the current review is to assess the current literature about electrospinning chitosan and its composite formulations for creating fibres in combination with other natural polymers to be employed in tissue engineering. In addition, various polymers blended with chitosan for electrospinning have been discussed in terms of their potential biomedical applications. The review shows that evidence exists in support of the favourable properties and biocompatibility of chitosan electrospun composite biomaterials for a range of applications. However, further research and in vivo studies are required to translate these materials from the laboratory to clinical applications

    The similarity question for biologicals and non-biological complex drugs

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    AbstractFor small – low molecular weight – molecule medicines a robust regulatory system has evolved over the years. This system guarantees high and constant quality of our (generic) medicines. Pharmaceutical equivalence and bioequivalence assessment are the pillars under that system. But there are complex medicines where the question of equivalence is more challenging to answer. For biologicals the paradigm of similarity rather than equality (the emergence of ‘biosimilars’) was developed in the past decade. This has been a program where an evolutionary, science based approach has been chosen by the frontrunner regulatory body, the EMA, with a ‘learn and confirm’ character.In addition, there is another group of complex drugs, the non-biological complex drugs, NBCDs, where the generic paradigm can be challenged as well. The NBCDs are defined as: 1. consisting of a complex multitude of closely related structures; 2. the entire multitude is the active pharmaceutical ingredient; 3. the properties cannot be fully characterized by physicochemical analysis and 4. the consistent, tightly controlled manufacturing process is fundamental to reproduce the product. NBCDs encompass product families such as the glatiramoids, liposomes, iron–carbohydrate colloids and many candidates of the group of the upcoming nanoparticulate systems. Following the main principles of regulatory pathways for biologicals (with appropriate product-by-product adjustments), instead of that for small molecules, would be the more logical strategy for these NBCDs.The status and outstanding regulatory issues for biosimilars and NBCD-similars/follow on versions were discussed at a conference in Budapest, Hungary (October 2014) and this commentary touches upon the issues brought up in the presentations, deliberations and conclusions

    β-Catenin Signaling Drives Differentiation and Proinflammatory Function of IRF8-Dependent Dendritic Cells.

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    β-Catenin signaling has recently been tied to the emergence of tolerogenic dendritic cells (DCs). In this article, we demonstrate a novel role for β-catenin in directing DC subset development through IFN regulatory factor 8 (IRF8) activation. We found that splenic DC precursors express β-catenin, and DCs from mice with CD11c-specific constitutive β-catenin activation upregulated IRF8 through targeting of the Irf8 promoter, leading to in vivo expansion of IRF8-dependent CD8α(+), plasmacytoid, and CD103(+)CD11b(-) DCs. β-Catenin-stabilized CD8α(+) DCs secreted elevated IL-12 upon in vitro microbial stimulation, and pharmacological β-catenin inhibition blocked this response in wild-type cells. Upon infections with Toxoplasma gondii and vaccinia virus, mice with stabilized DC β-catenin displayed abnormally high Th1 and CD8(+) T lymphocyte responses, respectively. Collectively, these results reveal a novel and unexpected function for β-catenin in programming DC differentiation toward subsets that orchestrate proinflammatory immunity to infection

    Expansion for the solutions of the Bogomolny equations on the torus

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    We show that the solutions of the Bogomolny equations for the Abelian Higgs model on a two-dimensional torus, can be expanded in powers of a quantity epsilon measuring the departure of the area from the critical area. This allows a precise determination of the shape of the solutions for all magnetic fluxes and arbitrary position of the Higgs field zeroes. The expansion is carried out to 51 orders for a couple of representative cases, including the unit flux case. We analyse the behaviour of the expansion in the limit of large areas, in which case the solutions approach those on the plane. Our results suggest convergence all the way up to infinite area.Comment: 26 pages, 8 figures, slightly revised version as published in JHE

    Anesthesia considerations for cataract surgery in patients with schizophrenia: A narrative review

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    Schizophrenia is ranked among the top 10 global burdens of disease. About 1 of people meet the diagnostic criteria for this disorder over their lifetime. Schizophrenic patients can develop cataract, particularly related to age and medications, requiring surgery and anesthesia. Many concerning factors, including cognitive function, anxiety, behavioral issues, poor cooperation and paroxysmal movements, may lead to general anesthesia as the default method. Antipsychotic agents should be continued during the periop-erative period if possible. Topical/regional anesthesia is suitable in most schizophrenic patients undergoing cataract surgery. It reduces potential drug interactions and many postoperative complications; however, appropriate patient selection is paramount to its success. General anesthesia remains the primary technique for patients who are considered unsuitable for the topical/regional technique. Early involvement of a psychiatrist in the perioperative period, especially for patients requiring general anesthesia, is beneficial but often under-utilized. This narrative review summarizes the anesthetic considerations for cataract surgery in patients with schizophrenia. Keywords. © 2021, Author(s)

    The Effects Of Dry And Chilled Air On Tool Wear Behavior During Face Milling Of Inconel 718

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    Tool wear is one of the important criteria during the cutting process. It is mostly caused by the machining parameters, namely; cutting speed, feed rate, depth of cut, cooling condition, etc. This paper presents the behavior of cutting tool during dry and chilled air condition of face mill with the cutting speed of 20 to 40 m/min, the feed rate of 0.1 to 0.2 mm/tooth and axial depth of 0.1 mm. The analysis of variance (ANOVA) is applied to identify the significance of these factors effect on tool performance, later the mathematical model for the tool life prediction was developed. The investigation revealed that the cutting speed, feed rate dominating wear rate whilst the chilled air found to be marginally significant. Finally, the optimum condition for machining parameter for greater tool life can be obtained by the combination cutting speed of 20 m/min, the feed rate of 0.1 mm/tooth under chilled air condition. Implementation of chilled air contributed 7% improvement with 45 min compared to a dry condition. The study exhibited the round type insert of dry face milling is more prone to rapid flank wear than chilled air with no BUE appearance on the tool cutting edge

    Patient preferences for the design of a pharmacy-based colorectal cancer screening program

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    Purpose: To assess preferences for design of a pharmacy-based colorectal cancer (CRC) screening program (PharmFIT™) among screening-eligible adults in the United States (US) and explore the impact of rurality on pharmacy use patterns (e.g., pharmacy type, prescription pick-up preference, service quality rating). Methods: We conducted a national online survey of non-institutionalized US adults through panels managed by Qualtrics, a survey research company. A total of 1,045 adults (response rate 62%) completed the survey between March and April 2021. Sampling quotas matched respondents to the 2010 US Census and oversampled rural residents. We assessed pharmacy use patterns by rurality and design preferences for learning about PharmFIT™; receiving a FIT kit from a pharmacy; and completing and returning the FIT kit. Results: Pharmacy use patterns varied, with some notable differences across rurality. Rural respondents used local, independently owned pharmacies more than non-rural respondents (20.4%, 6.3%, p < 0.001) and rated pharmacy service quality higher than non-rural respondents. Non-rural respondents preferred digital communication to learn about PharmFIT™ (36% vs 47%; p < 0.001) as well as digital FIT counseling (41% vs 49%; p = 0.02) more frequently than rural participants. Preferences for receiving and returning FITs were associated with pharmacy use patterns: respondents who pick up prescriptions in-person preferred to get their FIT (OR 7.7; 5.3–11.2) and return it in-person at the pharmacy (OR 1.7; 1.1–2.4). Conclusion: Pharmacies are highly accessible and could be useful for expanding access to CRC screening services. Local context and pharmacy use patterns should be considered in the design and implementation of PharmFIT™

    Evaluation of factors influencing <sup>18</sup>F-FET uptake in the brain.

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    PET using the amino-acid O-(2- &lt;sup&gt;18&lt;/sup&gt; F-fluoroethyl)-l-tyrosine ( &lt;sup&gt;18&lt;/sup&gt; F-FET) is gaining increasing interest for brain tumour management. Semi-quantitative analysis of tracer uptake in brain tumours is based on the standardized uptake value (SUV) and the tumour-to-brain ratio (TBR). The aim of this study was to explore physiological factors that might influence the relationship of SUV of &lt;sup&gt;18&lt;/sup&gt; F-FET uptake in various brain areas, and thus affect quantification of &lt;sup&gt;18&lt;/sup&gt; F-FET uptake in brain tumours. Negative &lt;sup&gt;18&lt;/sup&gt; F-FET PET scans of 107 subjects, showing an inconspicuous brain distribution of &lt;sup&gt;18&lt;/sup&gt; F-FET, were evaluated retrospectively. Whole-brain quantitative analysis with Statistical Parametric Mapping (SPM) using parametric SUV PET images, and volumes of interest (VOIs) analysis with fronto-parietal, temporal, occipital, and cerebellar SUV background areas were performed to study the effect of age, gender, height, weight, injected activity, body mass index (BMI), and body surface area (BSA). After multivariate analysis, female gender and high BMI were found to be two independent factors associated with increased SUV of &lt;sup&gt;18&lt;/sup&gt; F-FET uptake in the brain. In women, SUV &lt;sub&gt;mean&lt;/sub&gt; of &lt;sup&gt;18&lt;/sup&gt; F-FET uptake in the brain was 23% higher than in men (p &lt; 0.01). SUV &lt;sub&gt;mean&lt;/sub&gt; of &lt;sup&gt;18&lt;/sup&gt; F-FET uptake in the brain was positively correlated with BMI (r = 0.29; p &lt; 0.01). The influence of these factors on SUV of &lt;sup&gt;18&lt;/sup&gt; F-FET was similar in all brain areas. In conclusion, SUV of &lt;sup&gt;18&lt;/sup&gt; F-FET in the normal brain is influenced by gender and weakly by BMI, but changes are similar in all brain areas
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