1,503 research outputs found
Shear Strengthening of Self-Compacting Reinforced Concrete Deep Beams With External Bonded Layers
Self-compacting concrete (SCC) is a stable and highly flowable concrete. In this study, a new shear strengthening technique for reinforced self-compacting concrete (RSCC) deep beams was suggested and compared with some traditional techniques. An experimental test program consists of sixteen specimens of RSCC deep beams strengthened by different materials such as steel, glass and carbon fiber reinforced polymers (GFRP and CFRP) was executed. Externally bonded layers (EBL) and near surface mounted reinforcement (NSMR) were used as two different techniques. The effects of the new technique which depends on using intertwined roving NSM GFRP rods saturated with epoxy were compared with the other models. The new technique for shear strengthening increases the load capacity from 36% to 55% depending on the anchorage length of GFRP rods. Two dimensional nonlinear isoperimetric degenerated layered finite elements (FE) analysis was used to represent the SCC, reinforcement and strengthening layers of the tested models. The analytical results have been very close to the experimental results. Â
An immune-endocrine approach to identify biomarkers of outcomes following major burn injury in adults
Severe thermal injury induces a profound immune-inflammatory, endocrine and hypermetabolic response associated with poor outcomes including delayed wound healing, sepsis, multiorgan failure (MOF) and mortality. One urgent clinical need is to understand the mechanisms mediating the systemic response in order to identify prognostic biomarkers of outcome and develop new therapies.
This thesis analysed stored serum samples from a large observational study of severely burned patients (≥20% TBSA) at the Queen Elizabeth Hospital Birmingham. The HPA/HPG, Vitamin D, inflammatory, immune and adipokine responses were characterized from day of injury to 12 months post-injury and related to clinical outcomes including sepsis, MOF, wound healing, scarring and mortality.
Low DHEA, DHEAS, Testosterone and Vitamin D (25D3, Free 25D3, Bioavailable 25D3) status showed significant associations with poor outcomes including delayed wound healing, sepsis and mortality independent of age, gender and injury severity. Higher levels of DHEA, DHEAS, testosterone, Vitamin D and adiponectin were associated with improved scarring. Current burn treatments with potential influence on the endocrine system were also assessed. Corticosteroid use was associated with poor prognosis including sepsis, MOF and mortality, whereas Oxandrolone use was associated with improved outcomes. The data reveal several novel biomarkers of outcome that could also have therapeutic value
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A 3D printed drug delivery implant formed from a dynamic supramolecular polyurethane formulation
Using a novel molecular design approach, we have prepared a thermo-responsive supramolecular polyurethane as a matrix material for use in drug eluting implants. The dynamic supramolecular polyurethane (SPU) is able to self-assemble through hydrogen bonding and π-π stacking interactions, resulting in an addressable polymer network with a relatively low processing temperature. The mechanical properties of the SPU demonstrated the material was self-supporting, stiff, yet flexible thus making it suitable for hot-melt extrusion processing, inclusive of related 3D printing approaches. Cell-based toxicity assays revealed the SPU to be non-toxic and therefore a viable candidate as a biocompatible polymer for implant applications. To this end, the SPU was formulated with paracetamol (16 %w/w) and 4 wt% or 8 wt% poly(ethylene glycol) (PEG) as an excipient and hot melt extruded at 100 °C to afford a 3D printed prototype implant to explore the extended drug release required for an implant and the potential manipulation of the release profile. Furthermore, rheological, infra-red spectroscopy, powder X-ray diffraction and scanning electron microscopy studies revealed the chemical and physical properties and compatibility of the formulation components. Successful release of paracetamol was achieved from in vitro dissolution studies and it was predicted that the drug would be released over a period of up to 8.5 months with hydrophilic PEG being able to influence the release rate. This extended release time is consistent with applications of this novel dynamic polymer as a drug eluting implant matrix
A method for volume stabilization of single, dye-doped water microdroplets with femtoliter resolution
A self-control mechanism that stabilizes the size of Rhodamine B-doped water
microdroplets standing on a superhydrophobic surface is demonstrated. The
mechanism relies on the interplay between the condensation rate that was kept
constant and evaporation rate induced by laser excitation which critically
depends on the size of the microdroplets. The radii of individual water
microdroplets (>5 um) stayed within a few nanometers during long time periods
(up to 455 seconds). By blocking the laser excitation for 500 msec, the stable
volume of individual microdroplets was shown to change stepwise.Comment: to appear in the J. Op. Soc. Am.
Systemic absorption of oral vancomycin in a peripheral blood stem cell transplant patient with severe graft-versus-host disease of the gastrointestinal tract
Oral vancomycin is often considered the drug of choice for severe Clostridium difficile- associated disease due to both its efficacy and pharmacokinetics. The potential for absorption is not well described in patients with impaired gastrointestinal (GI) mucosa. We describe a case of significant and potentially toxic absorption of oral vancomycin in a peripheral blood stem cell transplant patient with grade IV graft-versus-host disease (GVHD) of the GI tract. In patients with GI GVHD clinicians need to be aware of the potential for oral absorption and, in select cases, monitoring of levels may be appropriate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74898/1/j.1399-3062.2009.00426.x.pd
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Molecular diagnosis in recessive pediatric neurogenetic disease can help reduce disease recurrence in families.
BackgroundThe causes for thousands of individually rare recessive diseases have been discovered since the adoption of next generation sequencing (NGS). Following the molecular diagnosis in older children in a family, parents could use this information to opt for fetal genotyping in subsequent pregnancies, which could inform decisions about elective termination of pregnancy. The use of NGS diagnostic sequencing in families has not been demonstrated to yield benefit in subsequent pregnancies to reduce recurrence. Here we evaluated whether genetic diagnosis in older children in families supports reduction in recurrence of recessive neurogenetic disease.MethodsRetrospective study involving families with a child with a recessive pediatric brain disease (rPBD) that underwent NGS-based molecular diagnosis. Prenatal molecular testing was offered to couples in which a molecular diagnosis was made, to help couples seeking to prevent recurrence. With this information, families made decisions about elective termination. Pregnancies that were carried to term were assessed for the health of child and mother, and compared with historic recurrence risk of recessive disease.ResultsBetween 2010 and 2016, 1172 families presented with a child a likely rPBD, 526 families received a molecular diagnosis, 91 families returned to the clinic with 101 subsequent pregnancies, and 84 opted for fetal genotyping. Sixty tested negative for recurrence for the biallelic mutation in the fetus, and all, except for one spontaneous abortion, carried to term, and were unaffected at follow-up. Of 24 that genotyped positive for the biallelic mutation, 16 were electively terminated, and 8 were carried to term and showed features of disease similar to that of the older affected sibling(s). Among the 101 pregnancies, disease recurrence in living offspring deviated from the expected 25% to the observed 12% ([95% CI 0·04 to 0·20], p = 0·011).ConclusionsMolecular diagnosis in an older child, coupled with prenatal fetal genotyping in subsequent pregnancies and genetic counselling, allows families to make informed decisions to reduce recessive neurogenetic disease recurrence
IRS-assisted millimeter-wave massive MIMO with transmit antenna selection for IoT networks
An intelligent reflecting surface (IRS)-assisted millimeter-wave (mmWave) massive multiple input multiple output (MIMO) system with transmit antenna selection (TAS) using orthogonal space-time block codes (OSTBC) scheme is proposed in this paper. This system combines TAS and IRS with hybrid analog-digital beamforming (HBF) for 60 GHz mmWave communications in order to exploit the benefits of TAS, OSTBC, analog beamforming (ABF), and transmit digital precoding techniques. The proposed system, however, benefits from the transmit diversity gain of OSTBC scheme as well as from the signal-to-noise ratio (SNR) gains of both the beamformer and the IRS technology. The simulation results show that TAS-OSTBC system with zero-forcing precoding outperforms the conventional TAS-OSTBC scheme. Furthermore, the bit error rate (BER) performance significantly improves as the number of antenna array elements increases due to providing a beamforming gain. In addition, increasing the number of reflecting elements further enhances the BER performance. It is also found from the simulation results that the TAS-OSTBC system with hybrid precoding has better performance than that of TAS-OSTBC with ABF, and IRS-assisted systems significantly outperform the conventional systems without the IRS technology. This makes the proposed IRS-assisted system an appealing solution for internet-of-things (IoT) networks
Non-Invasive Data Acquisition and IoT Solution for Human Vital Signs Monitoring: Applications, Limitations and Future Prospects
The rapid development of technology has brought about a revolution in healthcare stimulating a wide range of smart and autonomous applications in homes, clinics, surgeries and hospitals. Smart healthcare opens the opportunity for a qualitative advance in the relations between healthcare providers and end-users for the provision of healthcare such as enabling doctors to diagnose remotely while optimizing the accuracy of the diagnosis and maximizing the benefits of treatment by enabling close patient monitoring. This paper presents a comprehensive review of non-invasive vital data acquisition and the Internet of Things in healthcare informatics and thus reports the challenges in healthcare informatics and suggests future work that would lead to solutions to address the open challenges in IoT and non-invasive vital data acquisition. In particular, the conducted review has revealed that there has been a daunting challenge in the development of multi-frequency vital IoT systems, and addressing this issue will help enable the vital IoT node to be reachable by the broker in multiple area ranges. Furthermore, the utilization of multi-camera systems has proven its high potential to increase the accuracy of vital data acquisition, but the implementation of such systems has not been fully developed with unfilled gaps to be bridged. Moreover, the application of deep learning to the real-time analysis of vital data on the node/edge side will enable optimal, instant offline decision making. Finally, the synergistic integration of reliable power management and energy harvesting systems into non-invasive data acquisition has been omitted so far, and the successful implementation of such systems will lead to a smart, robust, sustainable and self-powered healthcare system
Antibacterial synergy of Tritirachium oryzae-produced silver nanoparticles with different antibiotics and essential oils derived from Cupressus sempervirens and Asteriscus graveolens (Forssk)
Purpose: To carry out eco-friendly biosynthesis of fungi-derived silver nanoparticles (AgNPs) and investigate their antibacterial synergies with essential oils (EOs) of Asteriscus graveolens (Forssk.) Less. and Cupressus sempervirens.
Methods: Biosynthesis of AgNPs was carried out using a cell-free filtrate of Tritirachium oryzae. The biosynthesized AgNPs characteristics were assessed using different methods, including ultravioletvisible spectrophotometry (UV), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy-dispersive x-ray spectroscopy (EDS) and transmission electron microscopy (TEM).
Results: Obvious synergistic effects were observed between AgNPs and chloramphenicol, vancomycin, nitrofurantoin or tetracycline with Pseudomonas aeruginosa, through increases in fold area of inhibition (IFAs) within the range of 2.4 to 9.0. Synergistic interactions were also seen between AgNPs and the antibiotics used, depending on the strain. Increase in IFA ranged from 1- to 3-fold for S. aureus, E. coli and P. aeruginosa. Similarly, combinations of AgNPs, EO of A. graveolens and cefotaxime, nitrofurantoin or amoxicillin against P. aeruginosa led to 10-, 3- and 10-fold synergy, respectively. In contrast, the use of AgNPs and trimethoprim, tetracycline or amoxicillin against E. coli led to 1 to 6-fold synergy. The best synergistic capacity resulted from AgNPs and the EO of C. sempervirens and trimethoprim against S. epidermidis, which yielded 29-fold increase in IFA. The use of combination of AgNPs and vancomycin against P. aeruginosa led to 16.4-fold enhancement of IFA.
Conclusion: The findings can potentially lead to the development of a new perception of antibacterial agents (innovative medications) involving the incorporation of nanoparticles (NPs) or new materials that potentially synergize with antibiotics, NPs and the EOs of different plants
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