1,116 research outputs found

    improving performance of feature extraction in sfm algorithms for 3d sparse point cloud

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    Abstract. The use of Structure-from-Motion algorithms is a common practice to obtain a rapid photogrammetric reconstruction. However, the performance of these algorithms is limited by the fact that in some conditions the resulting point clouds present low density. This is the case when processing materials from historical archives, such as photographs and videos, which generates only sparse point clouds due to the lack of necessary information in the photogrammetric reconstruction. This paper explores ways to improve the performance of open source SfM algorithms in order to guarantee the presence of strategic feature points in the resulting point cloud, even if sparse. To reach this objective, a photogrammetric workflow is proposed to process historical images. The first part of the workflow presents a method that allows the manual selection of feature points during the photogrammetric process. The second part evaluates the metric quality of the reconstruction on the basis of a comparison with a point cloud that has a different density from the sparse point cloud. The workflow was applied to two different case studies. Transformations of wall paintings of the Karanlık church in Cappadocia were analysed thanks to the comparison of 3D model resulting from archive photographs and a recent survey. Then a comparison was performed between the state of the Komise building in Japan, before and after restoration. The findings show that the method applied allows the metric scale and evaluation of the model also in bad condition and when only low-density point clouds are available. Moreover, this tool should be of great use for both art and architecture historians and geomatics experts, to study the evolution of Cultural Heritage

    24-hour blood pressure recording in patients with orthostatic hypotension.

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    Continuous intra-arterial blood pressure measurement and electrocardiograms were obtained in two ambulatory patients with orthostatic hypotension due to autonomic dysfunction. Systolic and diastolic arterial pressure presented marked variations which took place mainly during the day and were related to several physical activities; however, marked falls in blood pressure were also observed during sleep and at the moment of arousal. A peak incidence of hypotensive events was found in the afternoon, mainly in the hours following the afternoon meal. Recording was repeated after 3 weeks of treatment with propranolol, 40 mg t.i.d. In patient 1, beta blockade drastically reduced the number and severity of hypotensive episodes, while propranolol failed to control blood pressure in patient 2, who experienced a higher number of hypotensive events during treatment. Findings of this study may be relevant to the management of patients with orthostatic hypotension and should contribute to a more accurate characterization of blood pressure profile in autonomic dysfunction

    Platelet-Rich Plasma (PRP) and Adipose-Derived Stem Cell (ADSC) Therapy in the Treatment of Genital Lichen Sclerosus: A Comprehensive Review

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    Lichen sclerosus (LS) is a chronic inflammatory dermatosis mostly localized in the genital area, characterized by vulvar alterations that can severely impact a patient's quality of life. Current treatment modalities often provide incomplete relief, and there is a need for innovative approaches to manage this condition effectively. Platelet-rich plasma (PRP) and adipose-derived stem cells (ADSCs) have emerged as potential regenerative therapies for LS, offering promising results in clinical practice. This comprehensive review explores the utilization of PRP and ADSC therapy in the treatment of genital LS, highlighting their mechanisms of action, safety profiles, and clinical outcomes. PRP is a blood product enriched in growth factors and cytokines, which promotes tissue regeneration, angiogenesis, and immune modulation. ADSC regenerative potential relies not only in their plasticity but also in the secretion of trophic factors, and modulation of the local immune response. Numerous studies have reported the safety of PRP and ADSC therapy for genital LS. Adverse events are minimal and typically involve mild, self-limiting symptoms, such as transient pain and swelling at the injection site. Long-term safety data are encouraging, with no significant concerns identified in the literature. PRP and ADSC therapy have demonstrated significant improvements in LS-related symptoms, including itching, burning, dyspareunia, and sexual function. Additionally, these therapies enable many patients to discontinue the routine use of topical corticosteroids. Several studies have explored the efficacy of combining PRP and ADSC therapy for LS. In combination, PRP and ADSCs seem to offer a synergistic approach to address the complex pathophysiology of LS, particularly in the early stages. The use of PRP and ADSC therapy for genital lichen sclerosus represents a promising and safe treatment modality. These regenerative approaches have shown significant improvements in LS-related symptoms, tissue trophism, and histological features. Combination therapy, which harnesses the synergistic effects of PRP and ADSCs, is emerging as a preferred option, especially in early-stage LS cases. Further research, including randomized controlled trials and long-term follow-up, is warranted to elucidate the full potential and mechanisms of PRP and ADSC therapy in the management of genital LS. These regenerative approaches hold great promise in enhancing the quality of life of individuals suffering from this challenging condition

    Ultralow loading electroless deposition of IrOx on nickel foam for efficient and stable water oxidation catalysis

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    Abstract Photocatalysis and electrolysis are crucial processes for the development of a sustainable, clean energy system, since they enable solar fuel production, such as hydrogen by water splitting, as well as CO2 reduction. In these processes efficient and robust catalysts for water oxidation are required and the reduction of employed amount of noble metals is crucial to reduce costs and increase the sustainability of the technology. To obtain extremely low iridium loading on nickel foam electrodes we have employed electroless deposition by spontaneous galvanic displacement as a simple, low cost, highly scalable technique. After deposition the Ir oxidation has been achieved by annealing in air at 250 °C. By varying the deposition parameters, an optimal condition has been achieved, with an overpotential for water oxidation of 360 mV at 10 mA cm−2 in 1.0 M KOH solution. The Ni foam coverage with Ir oxide has also a positive impact on the electrode stability, strongly decreasing the degradation rate, compared to the case of bare Ni foam. The average amount of noble metal in the best performing electrode is only 35 μg cm−2 for a 1.6 mm thick Ni foam electrode. The proposed approach is highly promising for gas diffusion electrodes, and can be implemented in electrolytic cells, as well as in fuel cells

    Heart rate, pr, and qt intervals in normal children: A 24‐hour holter monitoring study

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    A dynamic electrocardiographic Holter monitoring study was performed in 32 healthy children (20 males and 12 females, age range 6-11 years old), without heart disease, according to clinical and noninvasive instrumental examination. We evaluated atrioventricular conduction time (PR), heart rate (HR), and QT interval patterns defining the range of normality of these electrocardiographic parameters. The PR interval ranged from 154 +/- 10 ms (mean +/- SD) for HR less than or equal to 60 to 102 +/- 12 ms for HR greater than or equal to 120 (range 85-180). The absolute mean HR was 87 +/- 10 beats/min (range 72-104), the minimum observed HR being 61 +/- 10 (range 51-79), the maximum 160 +/- 20 beats/min (range 129-186). Daytime mean HR gave a mean value of 93 +/- 10 (range 71-148), while during night hours it was 74 +/- 11 (range 54-98). The minimum QT interval averaged 261 +/- 10 ms for HR greater than 120 and the maximum 389 +/- 9 ms for HR less than or equal to 60; the corresponding mean value of QTc (i.e., QT corrected for HR) ranged from 388 +/- 8 for HR less than or equal to 60 beats/min to 403 +/- 14 ms for HR greater than 120 beats/min. The results of the present study provide data of normal children which can be readily compared against those of subjects in whom cardiac abnormalities are suspect or patient.(ABSTRACT TRUNCATED AT 250 WORDS

    Carotenoid Pigment Content in Durum Wheat (Triticum turgidum L. var durum): An Overview of Quantitative Trait Loci and Candidate Genes

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    Carotenoid pigment content is an important quality trait as it confers a natural bright yellow color to pasta preferred by consumers (whiteness vs. yellowness) and nutrients, such as provitamin A and antioxidants, essential for human diet. The main goal of the present review is to summarize the knowledge about the genetic regulation of the accumulation of pigment content in durum wheat grain and describe the genetic improvements obtained by using breeding approaches in the last two decades. Although carotenoid pigment content is a quantitative character regulated by various genes with additive effects, its high heritability has facilitated the durum breeding progress for this quality trait. Mapping research for yellow index and yellow pigment content has identified quantitative trait loci (QTL) on all wheat chromosomes. The major QTL, accounting for up to 60%, were mapped on 7L homoeologous chromosome arms, and they are explained by allelic variations of the phytoene synthase (PSY) genes. Minor QTL were detected on all chromosomes and associated to significant molecular markers, indicating the complexity of the trait. Despite there being currently a better knowledge of the mechanisms controlling carotenoid content and composition, there are gaps that require further investigation and bridging to better understand the genetic architecture of this important trait. The development and the utilization of molecular markers in marker-assisted selection (MAS) programs for improving grain quality have been reviewed and discussed

    A solar photothermocatalytic approach for the CO2 conversion: Investigation of different synergisms on CoO-CuO/brookite TiO2-CeO2 catalysts

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    The photoactive features of the least common polymorph of TiO2, i.e. brookite, were combined with the thermocatalytic redox ones of cerium oxide, focusing on the effects of the addition of small amounts of Co-Cu oxides for the solar CO2 conversion. By considering the characterization data, a surface segregation of the hosted metal oxides on the TiO2-CeO2 composite was evidenced, and their presence increased the amount of oxygen vacancies and improved the charge carriers separation. The bimetallic oxides-based sample was the most performing one in the photocatalytic carbon dioxide reduction at room temperature. The formation of carbon monoxide and methane was 5 and 0.5 μmol g−1h−1, respectively, i.e. about 10 times higher than that found with bare brookite. A further enhancement was obtained with the same CoO-CuO/TiO2-CeO2 catalyst applying the photothermal approach. The CO2-TPD and the FTIR measurements highlighted the high interaction between CO2 and the surface sites

    PlGFMMP9-engineered iPS cells supported on a PEGfibrinogen hydrogel scaffold possess an enhanced capacity to repair damaged myocardium

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    Cell-based regenerative therapies are significantly improved by engineering allografts to express factors that increase vascularization and engraftment, such as placental growth factor (PlGF) and matrix metalloproteinase 9 (MMP9). Moreover, the seeding of therapeutic cells onto a suitable scaffold is of utmost importance for tissue regeneration. On these premises, we sought to assess the reparative potential of induced pluripotent stem (iPS) cells bioengineered to secrete PlGF or MMP9 and delivered to infarcted myocardium upon a poly(ethylene glycol)-fibrinogen scaffold. When assessing optimal stiffness of the PEG-fibrinogen (PF) scaffold, we found that the appearance of contracting cells after cardiogenic induction was accelerated on the support designed with an intermediate stiffness. Revascularization and hemodynamic parameters of infarcted mouse heart were significantly improved by injection into the infarct of this optimized PF scaffold seeded with both MiPS (iPS cells engineered to secrete MMP9) and PiPS (iPS cells engineered to secrete PlGF) cells as compared with nonengineered cells or PF alone. Importantly, allograft-derived cells and host myocardium were functionally integrated. Therefore, survival and integration of allografts in the ischemic heart can be significantly improved with the use of therapeutic cells bioengineered to secrete MMP9 and PlGF and encapsulated within an injectable PF hydrogel having an optimized stiffness

    Antiabsence effects of carbenoxolone in two genetic animal models of absence epilepsy (WAG/Rij rats and lh/lh mice)

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    Carbenoxolone (CBX), the succinyl ester of glycyrrhetinic acid, is an inhibitor of gap junctional intercellular communication. We have tested its possible effects upon two genetic animal models of epilepsy (WAG/Rij rats and lethargic (lh/lh) mice). Systemic administration of CBX was unable to significantly affect the occurrence of absence seizures in WAG/Rij rats. In particular, intravenous (5-40 mg/kg) or intraperitoneal (i.p.; 10-80 mg/kg) administration of CBX was unable to significantly modify the number and duration of spike-wave discharges (SWDs) in WAG/Rij rats, whereas the bilateral microinjection (0.05, 0.1, 0.5 and 1 microg/0.5 microl) of CBX into nucleus reticularis thalami (NRT) and nucleus ventralis posterolateralis (VPL) thalami produced a decrease in the duration and the number of SWDs. Bilateral microinjection of CBX into nucleus ventroposteromedial (VPM) thalami did not produce any significant decrease in the number and duration of SWDs. On the contrary, i.p. (5-40 mg/kg) or intracerebroventricular (0.5, 1, 2 and 4 microg/2 microl) administration of CBX in lh/lh mice induced a marked decrease in the number and duration of SWDs in a dose-dependent manner. At the doses used no movement disorders, or other behavioural changes, were recorded in both WAG/Rij rats and lh/lh mice. No effects were observed in both animal models following systemic or focal administration of glycyrrhizin into the same brain areas where CBX was shown to be effective
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