2,414 research outputs found

    Amorphous formulations of indomethacin and griseofulvin prepared by electrospinning

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    Following an array of optimization experiments, two series of electrospun polyvinylpyrrolidone (PVP) fibers were prepared. One set of fibers contained various loadings of indomethacin, known to form stable glasses, and the other griseofulvin (a poor glass former). Drug loadings of up to 33% w/w were achieved. Electron microscopy data showed the fibers largely to comprise smooth and uniform cylinders, with evidence for solvent droplets in some samples. In all cases, the drug was found to exist in the amorphous physical state in the fibers on the basis of X-ray diffraction and differential scanning calorimetry (DSC) measurements. Modulated temperature DSC showed that the relationship between a formulation's glass transition temperature (Tg) and the drug loading follows the Gordon-Taylor equation, but not the Fox equation. The results of Gordon-Taylor analysis indicated that the drug/polymer interactions were stronger with indomethacin. The interactions between drug and polymer were explored in more detail using molecular modeling simulations and again found to be stronger with indomethacin; the presence of significant intermolecular forces was further confirmed using IR spectroscopy. The amorphous form of both drugs was found to be stable after storage of the fibers for 8 months in a desiccator (relative humidity <25%). Finally, the functional performance of the fibers was studied; in all cases, the drug-loaded fibers released their drug cargo very rapidly, offering accelerated dissolution over the pure drug

    Neuropsychiatric symptoms in 921 elderly subjects with dementia: a comparison between vascular and neurodegenerative types.

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    Objective:  i) to describe the neuropsychiatric profile of elderly subjects with dementia by comparing vascular (VaD) and degenerative dementias, i.e. dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD); ii) to assess whether the severity and type of dementia are associated with clinically relevant neuropsychiatric symptoms (CR‐NPS). Method:  One hundred and thirty‐one out‐patients with VaD, 100 with DLB and 690 with AD were studied. NPS were evaluated by the neuropsychiatric inventory (NPI). Results:  Vascular dementia had lower total and domain‐specific NPI scores and a lower frequency of CR‐NPS than AD and DLB, for which frequency of CR‐NPS increased significantly with disease severity, particularly in AD. Logistic regression analysis showed that a higher CDR score and a diagnosis of degenerative dementia were independently associated with CR‐NPS. Conclusion:  Vascular dementia is associated less with CR‐NPS than AD and DLB. Frequency of CR‐NPS increases with disease severity in AD and, to a lesser extent, in DLB

    Cytotoxic polyfunctionality maturation of cytomegalovirus-pp65-specific CD4 + and CD8 + T-cell responses in older adults positively correlates with response size

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    Cytomegalovirus (CMV) infection is one of the most common persistent viral infections in humans worldwide and is epidemiologically associated with many adverse health consequences during aging. Previous studies yielded conflicting results regarding whether large, CMV-specific T-cell expansions maintain their function during human aging. In the current study, we examined the in vitro CMV-pp65-reactive T-cell response by comprehensively studying five effector functions (i.e., interleukin-2, tumor necrosis factor-α, interferon-γ, perforin, and CD107a expression) in 76 seropositive individuals aged 70 years or older. Two data-driven, polyfunctionality panels (IL-2-associated and cytotoxicity-associated) derived from effector function co-expression patterns were used to analyze the results. We found that, CMV-pp65-reactive CD8 + and CD4 + T cells contained similar polyfunctional subsets, and the level of polyfunctionality was related to the size of antigen-specific response. In both CD8 + and CD4 + cells, polyfunctional cells with high cytotoxic potential accounted for a larger proportion of the total response as the total response size increased. Notably, a higher serum CMV-IgG level was positively associated with a larger T-cell response size and a higher level of cytotoxic polyfunctionality. These findings indicate that CMV-pp65-specific CD4 + and CD8 + T cell undergo simultaneous cytotoxic polyfunctionality maturation during aging

    Mechanical slowing-down of cytoplasmic diffusion allows in vivo counting of proteins in individual cells.

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    Many key regulatory proteins in bacteria are present in too low numbers to be detected with conventional methods, which poses a particular challenge for single-cell analyses because such proteins can contribute greatly to phenotypic heterogeneity. Here we develop a microfluidics-based platform that enables single-molecule counting of low-abundance proteins by mechanically slowing-down their diffusion within the cytoplasm of live Escherichia coli (E. coli) cells. Our technique also allows for automated microscopy at high throughput with minimal perturbation to native physiology, as well as viable enrichment/retrieval. We illustrate the method by analysing the control of the master regulator of the E. coli stress response, RpoS, by its adapter protein, SprE (RssB). Quantification of SprE numbers shows that though SprE is necessary for RpoS degradation, it is expressed at levels as low as 3-4 molecules per average cell cycle, and fluctuations in SprE are approximately Poisson distributed during exponential phase with no sign of bursting

    Gauge-independent MS‾\overline{MS} renormalization in the 2HDM

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    We present a consistent renormalization scheme for the CP-conserving Two-Higgs-Doublet Model based on MS‾\overline{MS} renormalization of the mixing angles and the soft-Z2Z_2-symmetry-breaking scale MsbM_{sb} in the Higgs sector. This scheme requires to treat tadpoles fully consistently in all steps of the calculation in order to provide gauge-independent SS-matrix elements. We show how bare physical parameters have to be defined and verify the gauge independence of physical quantities by explicit calculations in a general RξR_{\xi}-gauge. The procedure is straightforward and applicable to other models with extended Higgs sectors. In contrast to the proposed scheme, the MS‾\overline{MS} renormalization of the mixing angles combined with popular on-shell renormalization schemes gives rise to gauge-dependent results already at the one-loop level. We present explicit results for electroweak NLO corrections to selected processes in the appropriately renormalized Two-Higgs-Doublet Model and in particular discuss their scale dependence.Comment: 52 pages, PDFLaTeX, PDF figures, JHEP version with Eq. (5.23) correcte

    Obscuration beyond the nucleus: infrared quasars can be buried in extreme compact starbursts

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    \ua9 The Author(s) 2023. In the standard quasar model, the accretion disc obscuration is due to the canonical dusty torus. Here, we argue that a substantial part of the quasar obscuration can come from the interstellar medium (ISM) when the quasars are embedded in compact starbursts. We use an obscuration-unbiased sample of 578 infrared (IR) quasars at z ≈ 1–3 and archival Atacama Large Millimetre/submillimetre Array submillimetre host galaxy sizes to investigate the ISM contribution to the quasar obscuration. We calculate star formation rates (SFR) and ISM column densities for the IR quasars and a control sample of submillimetre galaxies (SMGs) not hosting quasar activity and show that: (1) the quasar obscured fraction is constant up to SFR ≈ 300 M☉ yr−1, and then increases towards higher SFR, suggesting that the ISM obscuration plays a significant role in starburst host galaxies, and (2) at SFR ≳ 300 M☉ yr−1, the SMGs and IR quasars have similarly compact submillimetre sizes (Re ≈ 0.5–3 kpc) and consequently, the ISM can heavily obscure the quasar, even reaching Compton-thick (NH &gt; 1024 cm−2) levels in extreme cases. Based on our results, we infer that ≈10–30 per cent of the IR quasars with SFR ≳ 300 M☉ yr−1 are obscured solely by the ISM

    Getting into hot water:sick guppies frequent warmer thermal conditions

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    Ectotherms depend on the environmental temperature for thermoregulation and exploit thermal regimes that optimise physiological functioning. They may also frequent warmer conditions to up-regulate their immune response against parasite infection and/or impede parasite development. This adaptive response, known as ‘behavioural fever’, has been documented in various taxa including insects, reptiles and fish, but only in response to endoparasite infections. Here, a choice chamber experiment was used to investigate the thermal preferences of a tropical freshwater fish, the Trinidadian guppy (Poecilia reticulata), when infected with a common helminth ectoparasite Gyrodactylus turnbulli, in female-only and mixed-sex shoals. The temperature tolerance of G. turnbulli was also investigated by monitoring parasite population trajectories on guppies maintained at a continuous 18, 24 or 32 °C. Regardless of shoal composition, infected fish frequented the 32 °C choice chamber more often than when uninfected, significantly increasing their mean temperature preference. Parasites maintained continuously at 32 °C decreased to extinction within 3 days, whereas mean parasite abundance increased on hosts incubated at 18 and 24 °C. We show for the first time that gyrodactylid-infected fish have a preference for warmer waters and speculate that sick fish exploit the upper thermal tolerances of their parasites to self medicate

    Effectiveness, cost-effectiveness and cost-benefit of a single annual professional intervention for the prevention of childhood dental caries in a remote rural Indigenous community

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    Background The aim of the study is to reduce the high prevalence of tooth decay in children in a remote, rural Indigenous community in Australia, by application of a single annual dental preventive intervention. The study seeks to (1) assess the effectiveness of an annual oral health preventive intervention in slowing the incidence of dental caries in children in this community, (2) identify the mediating role of known risk factors for dental caries and (3) assess the cost-effectiveness and cost-benefit of the intervention. Methods/design The intervention is novel in that most dental preventive interventions require regular re-application, which is not possible in resource constrained communities. While tooth decay is preventable, self-care and healthy habits are lacking in these communities, placing more emphasis on health services to deliver an effective dental preventive intervention. Importantly, the study will assess cost-benefit and cost-effectiveness for broader implementation across similar communities in Australia and internationally. Discussion There is an urgent need to reduce the burden of dental decay in these communities, by implementing effective, cost-effective, feasible and sustainable dental prevention programs. Expected outcomes of this study include improved oral and general health of children within the community; an understanding of the costs associated with the intervention provided, and its comparison with the costs of allowing new lesions to develop, with associated treatment costs. Findings should be generalisable to similar communities around the world. The research is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), registration number ACTRN12615000693527; date of registration: 3rd July 2015

    Periodontal disease and some adverse perinatal outcomes in a cohort of low risk pregnant women

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    Objective: To evaluate the association of periodontal disease (PD) in pregnancy with some adverse perinatal outcomes. Method: This cohort study included 327 pregnant women divided in groups with or without PD. Indexes of plaque and gingival bleeding on probing, probing pocket depth, clinical attachment level and gingival recession were evaluated at one periodontal examination below 32 weeks of gestation. The rates of preterm birth (PTB), low birth weight (LBW), small for gestational age (SGA) neonates and prelabor rupture of membranes (PROM) were evaluated using Risk Ratios (95%CI) and Population Attributable Risk Fractions. Results: PD was associated with a higher risk of PTB (RRadj. 3.47 95% CI 1.62-7.43), LBW (RRadj. 2.93 95% CI 1.36-6.34) and PROM (RRadj. 2.48 95% CI 1.35-4.56), but not with SGA neonates (RR 2.38 95% CI 0.93 - 6.10). Conclusions: PD was a risk factor for PT, LBW and PROM among Brazilian low risk pregnant women
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