333 research outputs found

    The role of color and false color in object recognition with degraded and non-degraded images

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    Recent technological advances in the design and manufacturing of night vision multispectral sensors now allow spatially registered imagery provided by each of the sensors to be combined within a single fused image for display to an end user. The product is a multispectral false colored rendering of the imaged scene. The use of false color in fused imagery may facilitate object recognition, providing contour information of the objects present in the scene, but incongruently colored fused imagery, may be disruptive of perceptual performance. This study investigated if the use of false color imagery compared to natural color, imagery was helpful or not in object recognition. Subjects' reaction times (RTs) and error rates were measured in a standard naming task. Stimuli consisted of photographs of food objects that had been manipulated in color (natural color, false color, natural grayscale, and false grayscale) and noise (three levels). The results of the experiment showed similar differences in RTs between color images (natural or false) and their grayscale counterparts at different levels of noise, indicating that both color conditions were similarly helpful in object recognition. These results give an indication that false color may be useful in multispectral sensors based on its facilitation of image segmentation with shape degraded images.http://www.archive.org/details/roleofcolorfalse00cavaN00173-99-WR-00215, DARPALieutenant Commander, Spanish NavyApproved for public release; distribution is unlimited

    Unlocking room-temperature bistable spin transition at the nanoscale: the synthesis of core@shell [Fe(NH 2 trz) 3 (NO 3 ) 2 ]@SiO 2 nanoparticles †

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    In this work, we address the synthesis of stable spin-crossover nanoparticles capable of undergoing a hysteretic spin transition at room temperature. For this purpose, we use the reverse-micelle protocol to prepare naked [Fe(NH2trz)3](NO3)2 and core@shell [Fe(NH2trz)3](NO3)2@SiO2 nanoparticles. Through meticulous adjustment of synthetic parameters, we achieved nanoparticle sizes ranging from approximately 40 nm to 60 nm. Our findings highlight that [Fe(NH2trz)3](NO3)2 presents a modest thermal hysteresis of 7 K, which decreases by downsizing. Conversely, silica-coated nanoparticles with sizes of ca. 60 and 40 nm demonstrate a remarkable hysteretic response of approximately 30 K, switching their spin state around room temperature. Moreover, the presence of a SiO2 shell substantially enhances the nanoparticles’ stability against oxidation. In this context, the larger 60 nm [Fe(NH2trz)3](NO3)2@SiO2 hybrid remains stable in water for up to two hours, enabling the observation of an unreported water-induced spin transition after 30 min. Therefore, this work also introduces an intriguing avenue for inducing spin transitions through solvent exchange, underscoring the versatility and potential of these nanoparticles

    Halide-mediated Modification of magnetism and electronic structure of α-Co (II) hydroxides: synthesis, characterization, and DFT+ U simulations

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    The present study introduces a comprehensive exploration in terms of physicochemical characterization and calculations based on density functional theory with Hubbard's correction (DFT+U) of the whole family of α-Co(II) hydroxyhalide (F, Cl, Br, I). These samples were synthesized at room temperature by employing a one-pot approach based on the epoxide route. A thorough characterization (powder X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis/mass spectroscopy, and magnetic and conductivity measurements) corroborated by simulation is presented that analyzes the structural, magnetic, and electronic aspects. Beyond the inherent tendency of intercalated anions to modify the interlayer distance, the halide's nature has a marked effect on several aspects. Such as the modulation of the CoOh to CoTd ratio, as well as the inherent tendency towards dehydration and irreversible decomposition. Whereas the magnetic behavior is strongly correlated with the CoTd amount reflected in the presence of glassy behavior with high magnetic disorder, the electrical properties depend mainly on the nature of the halide. The computed electronic structures suggest that the CoTd molar fraction exerts a minor effect on the inherent conductivity of the phases. However, the band gap of the solid turns out to be significantly dependent on the nature of the incorporated halide, governed by ligand to metal charge transfer, which minimizes the gap as the anionic radius becomes larger. Conductivity measurements of pressed pellets confirm this trend. To the best of our knowledge, this is the first report on the magnetic and electrical properties of α-Co(II) hydroxyhalides validated with in silico descriptions, opening the gate for the rational design of layered hydroxylated phases with tunable electrical, optical, and magnetic properties

    Controlling A<sub>x</sub>Mn[Fe(CN)<sub>6</sub>] charge transfer pathways through tilt-engineering for enhanced metal-to-metal interactions

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    The induction of structural distortion in a controlled manner through tilt engineering has emerged as a potent method to finely tune the physical characteristics of Prussian blue analogues. Notably, this distortion can be chemically induced by filling their pores with cations that can interact with the cyanide ligands. With this objective in mind, we optimized the synthetic protocol to produce the stimuli-responsive Prussian blue analogue AxMn[Fe(CN)6] with A = K+, Rb+, and Cs+, to tune its stimuli-responsive behavior by exchanging the cation inside pores. Our crystallographic analyses reveal that the smaller the cation, the more pronounced the structural distortion, with a notable 20-degree Fe–CN tilting when filling the cavities with K+, 10 degrees with Rb+, and 2 degrees with Cs+. Moreover, this controlled distortion offers a means to switch on/off its stimuli-responsive behavior, while modifying its magnetic response. Thereby empowering the manipulation of the PBA's physical properties through cationic exchang

    The randomized clinical trial trustworthiness crisis

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    Background The rising number of retracted randomised clinical trials (RCTs) is a concern over their trustworthiness. In today’s digital landscape electronic observational data is easily accessible for research purposes. This emerging perspective, in tandem with the growing scrutiny of RCT credibility, may steer some researchers towards favouring non-randomized studies. It is crucial to emphasize the ongoing need for robust RCTs, shedding light on the areas within trial design that require enhancements and addressing existing gaps in trial execution. Main body Evidence-based medicine pivots on the nexus between empirical medical research and the theoretical and applied facets of clinical care. Healthcare systems regularly amass patient data, creating a vast reservoir of information. This facilitates large-scale observational studies, which may appear as potential substitutes for RCTs. These large-scale studies inherently possess biases that place them a notch below randomized evidence. Honest errors, data manipulation, lapses in professionalism, and methodological shortcomings tarnish the integrity of RCTs, compromising trust in trials. Research institutions, funding agencies, journal editors and other stakeholders have the responsibility to establish robust frameworks to prevent both deliberate and inadvertent mishandling of RCT design, conduct and analysis. Systematic reviews that collate robust RCTs are invaluable. They amalgamate superior evidence instrumental in improving patient outcomes via informed health policy decisions. For systematic reviews to continue to retain trust, validated integrity assessment tools must be developed and routinely applied. This way it will be possible to prevent false or untrustworthy research from becoming part of the recommendations based on the evidence. Conclusion High-quality RCTs and their systematic reviews play a crucial role in acquiring valid and reliable evidence that is instrumental in improving patient outcomes. They provide vital information on healthcare effectiveness, and their trustworthiness is key to evidence-based medicine.Beatriz Galindo (senior modality) programme of the Spanish Ministry of Educatio

    The reproductive potential of vitrifiedwarmed euploid embryos declines following repeated uterine transfers

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    Background Recurrent implantation failure (RIF) represents a vague clinical condition with an unclear diagnostic challenge that lacks solid scientific underpinning. Although euploid embryos have demonstrated consistent implantation capabilities across various age groups, a unanimous agreement regarding the advantages of preimplantation genetic testing for aneuploidy (PGT-A) in managing RIF is absent. The ongoing discussion about whether chromosomal aneuploidy in embryos significantly contributes to recurrent implantation failure remains unsettled. Despite active discussions in recent times, a universally accepted characterization of recurrent implantation failure remains elusive. We aimed in this study to measure the reproductive performance of vitrified-warmed euploid embryos transferred to the uterus in successive cycles. Methods This observational cohort study included women (n = 387) with an anatomically normal uterus who underwent oocyte retrieval for PGT-A treatment with at least one biopsied blastocyst, between January 2017 and December 2021 at a university-affiliated public fertility center. The procedures involved in this study included ICSI, blastocyst culture, trophectoderm biopsy and comprehensive 24-chromosome analysis of preimplantation embryos using Next Generation Sequencing (NGS). Women, who failed a vitrified-warmed euploid embryo transfer, had successive blastocyst transfer cycles (FET) for a total of three using remaining cryopreserved euploid blastocysts from the same oocyte retrieval cycle. The primary endpoints were sustained implantation rate (SIR) and live birth rate (LBR) per vitrified-warmed single euploid embryo. The secondary endpoints were mean euploidy rate (m-ER) per cohort of biopsied blastocysts from each patient, as well as pregnancy and miscarriage rates. Results The mean age of the patient population was 33.4 years (95% CI 32.8–33.9). A total of 1,641 embryos derived from the first oocyte retrieval cycle were biopsied and screened. We found no associations between the m-ER and the number of previous failed IVF cycles among different ranges of maternal age at oocyte retrieval (P = 0.45). Pairwise comparisons showed a significant decrease in the sustained implantation rate (44.7% vs. 30%; P = 0.01) and the livebirth rate per single euploid blastocyst (37.1% vs. 25%; P = 0.02) between the 1st and 3rd FET. The cumulative SIR and LBR after up to three successive single embryo transfers were 77.1% and 68.8%, respectively. We found that the live birth rate of the first vitrified-warmed euploid blastocyst transferred decreased significantly with the increasing number of previously failed IVF attempts by categories (45.3% vs. 35.8% vs. 27.6%; P = 0.04). A comparable decrease in sustained implantation rate was also observed but did not reach statistical significance (50% vs. 44.2 vs. 37.9%; P = NS). Using a logistic regression model, we confirmed the presence of a negative association between the number of previous IVF failed attempts and the live birth rate per embryo transfer cycle (OR = 0.76; 95% CI 0.62–0.94; P = 0.01). Conclusions These findings are vital for enhancing patient counseling and refining management strategies for individuals facing recurrent implantation failure. By tailoring interventions based on age and ovarian reserve, healthcare professionals can offer more personalized guidance, potentially improving the overall success rates and patient experiences in fertility treatments

    Comparison of knowledge, attitudes and hand hygiene behavioral intention in medical and nursing students

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    Introduction Hand hygiene is crucial to prevent cross infection. Healthcare students are in a prime position to learn hand hygiene skills. The aim of this study was to analyze hand hygiene behavioral intentions of healthcare students before and after contact with the patient and to compare the knowledge of and attitude towards hand hygiene between medical and nursing students. Methods In a descriptive survey research design, convenience selection of a sample of medical students (n=657) and nursing students (n=303) was done from modules taught by the Department of Preventive Medicine and Public Health in both Medicine and Nursing undergraduate degrees in four Spanish universities. The hand hygiene Questionnaire, a validated instrument to evaluate behavior, knowledge, and attitudes, was used. Results A significantly lower percentage of students reported always or almost always carrying out hand hygiene before contact with the patient or invasive procedures in comparison to the percentage complying after contact with secretions or with the patient. Although hand hygiene knowledge appears acceptable, its importance is not sufficiently valued. Conclusions There are deficiencies in behavioral intention, knowledge, and attitudes related to hand hygiene in medical and nursing students. Better results are observed among nursing students, especially those who have received specific training

    Hospitalisation by tick-borne diseases in the last 10 years in two hospitals in South Spain: analysis of tick exposure data collected in the Emergency Department

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    Tick-borne diseases (TBDs) can sometimes cause severe symptoms and lead to hospitalisation, but they often go unnoticed in the Emergency Department (ED). The aim of this study was twofold: (i) to describe the profile of patients hospitalised by TBDs; and (ii) to evaluate the data collected in the medical records from the ED in order to analyse their potential clinical consequences. A total of 84 cases that included all TBD diagnoses registered in the ED records were identified and analysed. These corresponded to all the hospitalisations by TBDs in the last 10 years (2009–2019) in two tertiary hospitals in Granada, Spain. Statistical analyses were made using RStudio. Coinciding with the absence of patient’s report of exposure to ticks, 64.3% of TBDs were not suspected in the ED. Intensive care unit admission was required in 8.3% of cases, and the mortality rate was 2.4%. Non-suspected cases showed longer hospital stay (P < 0.001), treatment duration (P = 0.02) and delay in the initiation of antibiotic treatment (P < 0.001). Our findings indicate that symptoms associated with TBDs are highly non-specific. In the absence of explicit information related to potential tick exposure, TBDs are not initially suspected. As a consequence, elective treatment administration is delayed and hospitalisation time is prolonged. In conclusion, our results highlight the importance of addressing potential exposure to ticks during the ED contact with patients presenting with febrile syndrome

    The association between timed up and go test and history of falls: The Tromsø study

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    BACKGROUND: Fall-related injuries in older adults are a major health problem. Although the aetiology of falls is multifactorial, physical factors are assumed to contribute significantly. The "Timed up and go test" (TUG) is designed to measure basic mobility function. This report evaluates the association between TUG times and history of falls. METHODS: A retrospective, observational, population-based study was conducted on 414 men and 560 women with mean age 77.5 (SD 2.3). TUG time and falls during the previous 12 months were recorded. Covariates were age, sex, medical history and health-related mobility problems. Means, confidence intervals and test characteristics for TUG were calculated. Odds ratios and influence of covariates were examined by logistic regression. RESULTS: The mean TUG time was 11.1s (SD 2.5) among male non-fallers and 13.0s (SD 7.8) among fallers. The difference was 1.9s (95%CI 0.9–3.0). The odds ratio for fallers being in the upper quartile was 2.1 (95%CI 1.4–3.3). Adjusted for covariates, the odds ratio was (OR = 1.8, 95%CI 1.1–2.9). The corresponding mean was 13.0s (SD 5.74) among female non-fallers and 13.9s (SD 8.5) among fallers. The difference was 0.9 (95%CI -0.3–2.1). The odds ratio for fallers being in upper quartile was 1.0 (95%CI 0.7–1.4). The area under the ROC curve was 0.50 (95%CI 0.45–0.55) in women and 0.56 (95%CI 0.50–0.62) in men. CONCLUSION: TUG is statistically associated with a history of falls in men but not in women. The ability to classify fallers is poor, and the clinical value of the association is therefore limited
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