693 research outputs found
The NDE of Complex Liquids Containing Suspended Particles
Many products of commercial significance exist as suspensions of particles in a liquid or will have consisted as such as suspension at a stage during manufacture; the particles may be solid or liquid. It is necessary to determine the physical state of such suspensions both in the development laboratory and for the purposes of quality and process control at plant level. Reliable estimates are required of the size distribution and concentration of the dispersed phase, as well as indications of flocculation, and network formation. Dynamic measures may be required in support of reaction processes such as crystallization. Techniques that can be used for the characterisation of suspensions are optical scattering or turbidity tests, sedimentation rate tests, ionizing radiation, electrical tests, electroacoustic measurements, and acoustic (ultrasonic) methods alone. Ultrasonic methods have the advantages that they can be used on mixtures that are too opaque for optical techniques, and that they can be incorporated into robust and low cost instrumentation. This paper gives a brief overview of the physics of the interactions of ultrasonic waves with particulate suspensions and a brief review of measurement methods and errors. Recent results that show agreement or otherwise between theory and experiment are given for silica sols. Examples are also given of the use of ultrasound to track flocculation in an aqueous emulsion, and to track a crystallization reaction
Computerised interpretation of fetal heart rate during labour (INFANT) : a randomised controlled trial
Background: Continuous electronic fetal heart-rate monitoring is widely used during labour, and computerised interpretation could increase its usefulness. We aimed to establish whether the addition of decision-support software to assist in the interpretation of cardiotocographs affected the number of poor neonatal outcomes.
Methods: In this unmasked randomised controlled trial, we recruited women in labour aged 16 years or older having continuous electronic fetal monitoring, with a singleton or twin pregnancy, and at 35 weeks' gestation or more at 24 maternity units in the UK and Ireland. They were randomly assigned (1:1) to decision support with the INFANT system or no decision support via a computer-generated stratified block randomisation schedule. The primary outcomes were poor neonatal outcome (intrapartum stillbirth or early neonatal death excluding lethal congenital anomalies, or neonatal encephalopathy, admission to the neonatal unit within 24 h for >= 48 h with evidence of feeding difficulties, respiratory illness, or encephalopathy with evidence of compromise at birth), and developmental assessment at age 2 years in a subset of surviving children. Analyses were done by intention to treat. This trial is completed and is registered with the ISRCTN Registry, number 98680152.
Findings: Between Jan 6, 2010, and Aug 31, 2013, 47 062 women were randomly assigned (23 515 in the decision-support group and 23 547 in the no-decision-support group) and 46 042 were analysed (22 987 in the decision-support group and 23 055 in the no-decision-support group). We noted no difference in the incidence of poor neonatal outcome between the groups-172 (0.7%) babies in the decision-support group compared with 171 (0.7%) babies in the no-decision-support group (adjusted risk ratio 1.01, 95% CI 0.82-1.25). At 2 years, no significant differences were noted in terms of developmental assessment.
Interpretation: Use of computerised interpretation of cardiotocographs in women who have continuous electronic fetal monitoring in labour does not improve clinical outcomes for mothers or babies
Driving fiber diameters to the limit: nanoparticle-induced diameter reductions in electrospun photoactive composite nanofibers for organic photovoltaics
Electrospun photoactive nanofibers hold significant potential for enhanced photon absorption and charge transport in organic photovoltaics. However, electrospinning conjugated polymers with fiber diameters comparable to exciton diffusion lengths for efficient dissociation, is difficult. Previously, spinning sub-100 nm poly(3-hexylthiophene) (P3HT) fibers has required the auxiliary polymer, poly(ethylene oxide) (PEO), and large antisolvent additions. Therefore, its success differs considerably across donor polymers, due to variable antisolvent addition limits before precipitation. Herein, plasmonic nanoparticle infusion into P3HT nanofibers is used to modulate viscosity and deliver a novel and unrivaled strategy to achieve reduced fiber diameters. Following PEO removal, the fibers measure 55 nm in diameter, 30% lower than any previous report – providing the shortest exciton diffusion pathways to the heterojunction upon electron acceptor infiltration. The nanoparticle-containing nanofibers present a 58% enhancement over their pristine thin-film counterparts. ~17% is ascribed to plasmonic effects, demonstrated in thin-films, and the remainder to along-fiber polymer chain alignment, introduced by electrospinning. The anisotropy of light absorbed when polarized parallel versus perpendicular to the fibers increases from 0.88 to 0.62, suggesting the diameter reduction improves the alignment, resulting in greater electrospinning-induced enhancements. Controlled by the electrospinning behavior of PEO, our platform may be adapted to contemporary donor-acceptor systems
The effect of different dosing regimens of motesanib on the gallbladder: a randomized phase 1b study in patients with advanced solid tumors
Extent: 11 p.BACKGROUND: Gallbladder toxicity, including cholecystitis, has been reported with motesanib, an orally administered small-molecule antagonist of VEGFRs 1, 2 and 3; PDGFR; and Kit. We assessed effects of motesanib on gallbladder size and function. METHODS: Patients with advanced metastatic solid tumors ineligible for or progressing on standard-of-care therapies with no history of cholecystitis or biliary disease were randomized 2:1:1 to receive motesanib 125 mg once daily (Arm A); 75 mg twice daily (BID), 14-days-on/7-days-off (Arm B); or 75 mg BID, 5-days-on/2-days-off (Arm C). Primary endpoints were mean change from baseline in gallbladder size (volume by ultrasound; independent review) and function (ejection fraction by CCK-HIDA; investigator assessment). RESULTS: Forty-nine patients received ≥1 dose of motesanib (Arms A/B/C, n = 25/12/12). Across all patients, gallbladder volume increased by a mean 22.2 cc (from 38.6 cc at baseline) and ejection fraction decreased by a mean 19.2% (from 61.3% at baseline) during treatment. Changes were similar across arms and appeared reversible after treatment discontinuation. Three patients had cholecystitis (grades 1, 2, 3, n = 1 each) that resolved after treatment discontinuation, one patient developed grade 3 acute cholecystitis requiring cholecystectomy, and two patients had other notable grade 1 gallbladder disorders (gallbladder wall thickening, gallbladder dysfunction) (all in Arm A). Two patients developed de novo gallstones during treatment. Twelve patients had right upper quadrant pain (Arms A/B/C, n = 8/1/3). The incidence of biliary “sludge” in Arms A/B/C was 39%/36%/27%. CONCLUSION: Motesanib treatment was associated with increased gallbladder volume, decreased ejection fraction, biliary sludge, gallstone formation, and infrequent cholecystitis. Trial registration: ClinicalTrials.gov NCT00448786Lee S. Rosen, Lara Lipton, Timothy J. Price, Neil D. Belman, Ralph V. Boccia, Herbert I. Hurwitz, Joe J. Stephenson Jr., Lori J. Wirth, Sheryl McCoy, Yong-jiang Hei, Cheng-Pang Hsu and Niall C. Tebbut
Feasibility and design of a trial regarding the optimal mode of delivery for preterm birth: the CASSAVA multiple methods study
BACKGROUND: Around 60,000 babies are born preterm (prior to 37 weeks' gestation) each year in the UK. There is little evidence on the optimal birth mode (vaginal or caesarean section). OBJECTIVE: The overall aim of the CASSAVA project was to determine if a trial to define the optimal mode of preterm birth could be carried out and, if so, determine what sort of trial could be conducted and how it could best be performed. We aimed to determine the specific groups of preterm women and babies for whom there are uncertainties about the best planned mode of birth, and if there would be willingness to recruit to, and participate in, a randomised trial to address some, but not all, of these uncertainties. This project was conducted in response to a Heath Technology Assessment programme commissioning call (17/22 'Mode of delivery for preterm infants'). METHODS: We conducted clinician and patient surveys (n = 224 and n = 379, respectively) to identify current practice and opinion, and a consensus survey and Delphi workshop (n = 76 and n = 22 participants, respectively) to inform the design of a hypothetical clinical trial. The protocol for this clinical trial/vignette was used in telephone interviews with clinicians (n = 24) and in focus groups with potential participants (n = 13). RESULTS: Planned sample size and data saturation was achieved for all groups except for focus groups with participants, as this had to be curtailed because of the COVID-19 pandemic and data saturation was not achieved. There was broad agreement from parents and health-care professionals that a trial is needed. The clinician survey demonstrated a variety of practice and opinion. The parent survey suggested that women and their families generally preferred vaginal birth at later gestations and caesarean section for preterm infants. The interactive workshop and Delphi consensus process confirmed the need for more evidence (hence the case for a trial) and provided rich information on what a future trial should entail. It was agreed that any trial should address the areas with most uncertainty, including the management of women at 26-32 weeks' gestation, with either spontaneous preterm labour (cephalic presentation) or where preterm birth was medically indicated. Clear themes around the challenges inherent in conducting any trial emerged, including the concept of equipoise itself. Specific issues were as follows: different clinicians and participants would be in equipoise for each clinical scenario, effective conduct of the trial would require appropriate resources and expertise within the hospital conducting the trial, potential participants would welcome information on the trial well before the onset of labour and minority ethnic groups would require tailored approaches. CONCLUSION: Given the lack of evidence and the variation of practice and opinion in this area, and having listened to clinicians and potential participants, we conclude that a trial should be conducted and the outlined challenges resolved. FUTURE WORK: The CASSAVA project could be used to inform the design of a randomised trial and indicates how such a trial could be carried out. Any future trial would benefit from a pilot with qualitative input and a study within a trial to inform optimal recruitment. LIMITATIONS: Certainty that a trial could be conducted can be determined only when it is attempted. TRIAL REGISTRATION: Current Controlled Trials ISRCTN12295730. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 61. See the NIHR Journals Library website for further project information
Phagocytosis of Aspergillus fumigatus by Human Bronchial Epithelial Cells Is Mediated by the Arp2/3 Complex and WIPF2
Aspergillus fumigatus is an opportunistic fungal pathogen capable of causing severe infection in humans. One of the limitations in our understanding of how A. fumigatus causes infection concerns the initial stages of infection, notably the initial interaction between inhaled spores or conidia and the human airway. Using publicly-available datasets, we identified the Arp2/3 complex and the WAS-Interacting Protein Family Member 2 WIPF2 as being potentially responsible for internalization of conidia by airway epithelial cells. Using a cell culture model, we demonstrate that RNAi-mediated knockdown of WIPF2 significantly reduces internalization of conidia into airway epithelial cells. Furthermore, we demonstrate that inhibition of Arp2/3 by a small molecule inhibitor causes similar effects. Using super-resolution fluorescence microscopy, we demonstrate that WIPF2 is transiently localized to the site of bound conidia. Overall, we demonstrate the active role of the Arp2/3 complex and WIPF2 in mediating the internalization of A. fumigatus conidia into human airway epithelial cells
Nanostructure and photovoltaic potential of plasmonic nanofibrous active layers
Nanofibrous active layers offer hierarchical control over molecular structure, and the size and distribution of electron donor:acceptor domains, beyond conventional organic photovoltaic architectures. This structure is created by forming donor pathways via electrospinning nanofibers of semiconducting polymer, then infiltrating with an electron acceptor. Electrospinning induces chain and crystallite alignment, resulting in enhanced light-harvesting and charge transport. Here, the charge transport capabilities are predicted, and charge separation and dynamics are evaluated in these active layers, to assess their photovoltaic potential. Through X-ray and electron diffraction, the fiber nanostructure is elucidated, with uniaxial elongation of the electrospinning jet aligning the polymer backbones within crystallites orthogonal to the fiber axis, and amorphous chains parallel. It is revealed that this structure forms when anisotropic crystallites, pre-assembled in solution, become oriented along the fiber– a configuration with high charge transport potential. Competitive dissociation of excitons formed in the photoactive nanofibers is recorded, with 95%+ photoluminescence quenching upon electron acceptor introduction. Transient absorption studies reveal that silver nanoparticle addition to the fibers improves charge generation and/or lifetimes. 1 ns post-excitation, the plasmonic architecture contains 45% more polarons, per exciton formed, than the bulk heterojunction. Therefore, enhanced exciton populations may be successfully translated into additional charge carriers
A phase II study of weekly cisplatin, 6S-stereoisomer leucovorin and fluorouracil as first-line chemotherapy for elderly patients with advanced gastric cancer
The incidence of gastric cancer (GC) increases significantly after the fifth decade and palliative chemotherapy is the ultimate treatment in the majority of patients. We investigated safety and efficacy of a weekly regimen with cisplatin, fluorouracil and leucovorin as first-line chemotherapy for elderly patients with advanced GC. Chemotherapy-naive patients older than 65 years were considered eligible for study entry. Frail elderly patients were identified and excluded according to the following criteria: age >85 years, dependence in one or more activities of daily living (activities of daily living and instrumental activities of daily living scales), three or more comorbid conditions, one or more geriatric syndromes. Chemotherapy consisted of 1-day per week administration of intravenous cisplatin 35 mg m(-2), 6S-stereoisomer leucovorin 250 mg m(-2) and fluorouracil 500 mg m(-2) (PLF). Patients were re-evaluated after eight weekly cycles and six additional weekly administrations were planned for patients without disease progression. A 5-day subcutaneous filgrastim (5 mug Kg(-1) day(-1), days +1-+5) was used after the first treatment delay for neutropenia and maintained thereafter. In the whole group, the best intention-to-treat overall response rate was 43\% (95\% CI: 30-56\%). The time to disease progression and the median survival time were 5.3 and 8.6 months, respectively. Fatigue was the commonest nonhaematologic toxicity (71\% of the patients). Filgrastim was used in 30 patients who showed grade II (20 patients) or grade III (10 patients) neutropenia. Neither grade IV toxicity nor toxic deaths were observed. The weekly PLF regimen resulted safe and effective in elderly patients with advanced GC. This outpatient regimen is based on old and low-cost drugs and it may represent an alternative to new and more expensive combinations
Capecitabine and mitomycin C as third-line therapy for patients with metastatic colorectal cancer resistant to fluorouracil and irinotecan
Protracted venous infusion 5-fluorouracil (5FU) combined with mitomycin C (MMC) has demonstrated significant activity against metastatic colorectal cancer. Owing to potential synergy based upon upregulation of thymidine phosphorylase by MMC, the combination of capecitabine and MMC may improve outcomes in irinotecan-refractory disease. Eligible patients with progressive disease during or within 6 months of second-line chemotherapy were treated with capecitabine (1250 mg m−2 twice daily) days 1–14 every 3 weeks and MMC (7 mg m−2 IV bolus) once every 6 weeks. A total of 36 patients were recruited, with a median age of 64 years (range 40–77), and 23 patients (78%) were performance status 0–1. The objective response rate was 15.2%. In all, 48.5% of patients had stable disease. Median failure-free survival was 5.4 months (95% CI 4.6–6.2). Median overall survival was 9.3 months (95% CI: 6.9–11.7). Grade 3 toxicities were palmar-plantar erythema 16.7%, vomiting 8.3%, diarrhoea 2.8%, anaemia 8.3%, and neutropenia 2.8%. No patients developed haemolytic uraemic syndrome. Symptomatic improvement occurred for pain, bowel symptoms, and dyspnoea. Capecitabine in combination with MMC is an effective regimen for metastatic colorectal cancer resistant to 5FU and irinotecan with an acceptable toxicity profile and a convenient administration schedule
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