520 research outputs found

    Ligand-targeted liposomes directed against pathological vasculature

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    The development of liposomes targeted to angiogenic endothelial cells offers exciting prospects for intervention in cancer and inflammation. Several proteins are (strongly) over-expressed on angiogenic endothelial cells as compared to the quiescent endothelium, and could potentially serve as targets for site-specific drug delivery. In this contribution particular attention is given to the design of targeted long-circulating liposomes directed against the alpha v beta 3-integrin protein

    Lie detector

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    Novel, semicrystalline polyamides and copolyamides were synthesized from a new carbohydrate-based diamine, namely isoidide-2,5-dimethyleneamine (IIDMA). In combination with 1,6-hexamethylene diamine (1,6-HDA) as well as the biobased sebacic acid (SA) or brassylic acid (BrA), the desired copolyamides were obtained via melt polymerization of the nylon salts followed by a solid-state polycondensation (SSPC) process. Depending on the chemical compositions, the number average molecular weights (Mn) of the polyamides were in the range of 4000–49000 g/mol. With increasing IIDMA content in the synthesized copolyamides, their corresponding glass transition temperatures (Tg) increased from 50 °C to approximately 60–67 °C while the melting temperatures (Tm) decreased from 220 to 160 °C. The chemical structures of the polyamides were analyzed by NMR and FT-IR spectroscopy. Both differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) analyses revealed the semicrystalline character of these novel copolyamides. Variable-temperature (VT) 13C{1H} cross-polarization/magic-angle spinning (CP/MAS) NMR and FT-IR techniques were employed to study the crystal structures as well as the distribution of IIDMA moieties over the crystalline and amorphous phases of the copolyamides. The performed ab initio calculations reveal that the stability of the IIDMA moieties is due to a pronounced boat conformation of the bicyclic rings. The incorporation of methylene segments in between the isohexide group and the amide groups enables the hydrogen bonds formation and organization of the polymer chain fragments. Given the sufficiently high Tm values (200 °C) of the copolyamides containing less than 50% of IIDMA, these biobased semicrystalline copolyamides can be useful for engineering plastic applications

    Long-term results after Boston brace treatment in late-onset juvenile and adolescent idiopathic scoliosis

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    <p>Abstract</p> <p>Background</p> <p>It is recommended that research in patients with idiopathic scoliosis should focus on short- and long-term patient-centred outcome. The aim of the present study was to evaluate outcome in patients with late-onset juvenile or adolescent idiopathic scoliosis 16 years or more after Boston brace treatment.</p> <p>Methods</p> <p>272 (78%) of 360 patients, 251 (92%) women, responded to follow-up examination at a mean of 24.7 (range 16 - 32) years after Boston brace treatment. Fifty-eight (21%) patients had late-onset juvenile and 214 had adolescent idiopathic scoliosis. All patients had clinical and radiological examination and answered a standardised questionnaire including work status, demographics, General Function Score (GFS) (100 - worst possible) and Oswestry Disability Index (ODI) (100 - worst possible), EuroQol (EQ-5D) (1 - best possible), EQ-VAS (100 - best possible), and Scoliosis Research Society - 22 (SRS - 22) (5 - best possible).</p> <p>Results</p> <p>The mean age at follow-up was 40.4 (31-48) years. The prebrace major curve was in average 33.2 (20 - 57)°. At weaning and at the last follow-up the corresponding values were 28.3 (1 - 58)° and 32.5 (7 - 80)°, respectively. Curve development was similar in patients with late-onset juvenile and adolescent start. The prebrace curve increased > 5° in 31% and decreased > 5° in 26%. Twenty-five patients had surgery. Those who did not attend follow-up (n = 88) had a lower mean curve at weaning: 25.4 (6-53)°. Work status was 76% full-time and 10% part-time. Eighty-seven percent had delivered a baby, 50% had pain in pregnancy. The mean (SD) GFS was 7.4 (10.8), ODI 9.3 (11.0), EQ-5D 0.82 (0.2), EQ-VAS 77.6 (17.8), SRS-22: pain 4.1 (0.8), mental health 4.1 (0.6), self-image 3.7 (0.7), function 4.0 (0.6), satisfaction with treatment 3.7 (1.0). Surgical patients had significantly reduced scores for SRS-physical function and self-image, and patients with curves ≥ 45° had reduced self-image.</p> <p>Conclusion</p> <p>Long-term results were satisfactory in most braced patients and similar in late-onset juvenile and idiopathic adolescent scoliosis.</p

    Overdiagnosis and overtreatment of breast cancer: Microsimulation modelling estimates based on observed screen and clinical data

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    There is a delicate balance between the favourable and unfavourable side-effects of screening in general. Overdiagnosis, the detection of breast cancers by screening that would otherwise never have been clinically diagnosed but are now consequently treated, is such an unfavourable side effect. To correctly model the natural history of breast cancer, one has to estimate mean durations of the different pre-clinical phases, transition probabilities to clinical cancer stages, and sensitivity of the applied test based on observed screen and clinical data. The Dutch data clearly show an increase in screen-detected cases in the 50 to 74 year old age group since the introduction of screening, and a decline in incidence around age 80 years. We had estimated that 3% of total incidence would otherwise not have been diagnosed clinically. This magnitude is no reason not to offer screening for women aged 50 to 74 years. The increases in ductal carcinoma in situ (DCIS) are primarily due to mammography screening, but DCIS still remains a relatively small proportion of the total breast cancer problem

    The effect of ambient temperature on gross-efficiency in cycling

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    Time-trial performance deteriorates in the heat. This might potentially be the result of a temperature-induced decrease in gross-efficiency (GE). The effect of high ambient temperature on GE during cycling will be studied, with the intent of determining if a heat-induced change in GE could account for the performance decrements in time trial exercise found in literature. Ten well-trained male cyclists performed 20-min cycle ergometer exercise at 60% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}PVO2max P_{V{\text{O}}_{{\text{2max}}} }\end{document} (power output at which VO2max was attained) in a thermo-neutral climate (N) of 15.6 ± 0.3°C, 20.0 ± 10.3% RH and a hot climate (H) of 35.5 ± 0.5°C, 15.5 ± 3.2% RH. GE was calculated based on VO2 and RER. Skin temperature (Tsk), rectal temperature (Tre) and muscle temperature (Tm) (only in H) were measured. GE was 0.9% lower in H compared to N (19.6 ± 1.1% vs. 20.5 ± 1.4%) (P < 0.05). Tsk (33.4 ± 0.6°C vs. 27.7 ± 0.7°C) and Tre (37.4 ± 0.6°C vs. 37.0 ± 0.6°C) were significantly higher in H. Tm was 38.7 ± 1.1°C in H. GE was lower in heat. Tm was not high enough to make mitochondrial leakage a likely explanation for the observed reduced GE. Neither was the increased Tre. Increased skin blood flow might have had a stealing effect on muscular blood flow, and thus impacted GE. Cycling model simulations showed, that the decrease in GE could account for half of the performance decrement. GE decreased in heat to a degree that could explain at least part of the well-established performance decrements in the heat

    DMAIC Approach for the Reduction of Healthcare-Associated Infections in the Neonatal Intensive Care Unit of the University Hospital of Naples ‘Federico II’

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    Improvements in the obstetrical and neonatal management have allowed children to survive. These enhancements have showed, anyway, a general increased incidence of healthcare-associated infections, one of the most influent causes of morbidity and mortality in neonatal intensive care units. The aim of this paper is to suggest corrective measures to reduce sentinel germs colonization and identify the relationships between bacteria colonization with the number of procedures and the length of hospital stay. The Lean Six Sigma methodology was used to tackle this issue using a tailored Define, Measure, Analyze, Improve, and Control problem-solving strategy. An increased number of procedures and an extended length of hospital stay demonstrated a statistically significant influence on newborns’ possibility to be infected by sentinel germs. These findings could guide the clinical staff to improve the management of neonates in neonatal intensive care units reducing the number of infected patients, their length of hospital stay and the costs for the hospital. © 2021, Springer Nature Switzerland AG

    Dedicated bifurcation analysis: basic principles

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    Over the last several years significant interest has arisen in bifurcation stenting, in particular stimulated by the European Bifurcation Club. Traditional straight vessel analysis by QCA does not satisfy the requirements for such complex morphologies anymore. To come up with practical solutions, we have developed two models, a Y-shape and a T-shape model, suitable for bifurcation QCA analysis depending on the specific anatomy of the coronary bifurcation. The principles of these models are described in this paper, as well as the results of validation studies carried out on clinical materials. It can be concluded that the accuracy, precision and applicability of these new bifurcation analyses are conform the general guidelines that have been set many years ago for conventional QCA-analyses

    A Sex-Specific Metabolite Identified in a Marine Invertebrate Utilizing Phosphorus-31 Nuclear Magnetic Resonance

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    Hormone level differences are generally accepted as the primary cause for sexual dimorphism in animal and human development. Levels of low molecular weight metabolites also differ between men and women in circulating amino acids, lipids and carbohydrates and within brain tissue. While investigating the metabolism of blue crab tissues using Phosphorus-31 Nuclear Magnetic Resonance, we discovered that only the male blue crab (Callinectes sapidus) contained a phosphorus compound with a chemical shift well separated from the expected phosphate compounds. Spectra obtained from male gills were readily differentiated from female gill spectra. Analysis from six years of data from male and female crabs documented that the sex-specificity of this metabolite was normal for this species. Microscopic analysis of male and female gills found no differences in their gill anatomy or the presence of parasites or bacteria that might produce this phosphorus compound. Analysis of a rare gynandromorph blue crab (laterally, half male and half female) proved that this sex-specificity was an intrinsic biochemical process and was not caused by any variations in the diet or habitat of male versus female crabs. The existence of a sex-specific metabolite is a previously unrecognized, but potentially significant biochemical phenomenon. An entire enzyme system has been synthesized and activated only in one sex. Unless blue crabs are a unique species, sex-specific metabolites are likely to be present in other animals. Would the presence or absence of a sex-specific metabolite affect an animal's development, anatomy and biochemistry
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