184 research outputs found

    Bis[hexa­amminecobalt(III)] penta­chloride nitrate

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    The title compound, [Co(NH3)6]2Cl5(NO3), was obtained under hydro­thermal conditions. The asymmetric unit contains three Co3+ ions, one lying on an inversion center and the other two located at 2/m positions. All Co3+ ions are six-coordinated by NH3 mol­ecules, forming [Co(NH3)6]3+ octahedra, with Co—N distances in the range 1.945 (4)–1.967 (3) Å. The nitrate N atom and one of the O atoms lie at a mirror plane. Among the Cl− anions, one lies in a general position, one on a twofold axis and two on a mirror plane. N—H⋯O and N—H⋯Cl hydrogen bonds link the cations and anions into a three-dimensional network

    IOT network: models, structure, communications, problems

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    A brief analysis of the concepts and applications of IoT networks is carried out. Four models of building these networks as variants of component interaction are given: terminal, gateway, cloud, application. Variants of IoT network architectures are presented. Seven variants of interaction in Yota networks are considered. The analysis of problems in these networks and the direction of their solution are carried out

    A Systematic Approach for Making 3D-Printed Patient-Specific Implants for Craniomaxillofacial Reconstruction

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    Craniomaxillofacial reconstruction implants, which are extensively used in head and neck surgery, are conventionally made in standardized forms. During surgery, the implant must be bended manually to match the anatomy of the individual bones. The bending process is time-consuming, especially for inexperienced surgeons. Moreover, repetitive bending may induce undesirable internal stress concentration, resulting in fatigue under masticatory loading in vivo and causing various complications such as implant fracture, screw loosening, and bone resorption. There have been reports on the use of patient-specific 3D-printed implants for craniomaxillofacial reconstruction, although few reports have considered implant quality. In this paper, we present a systematic approach for making 3D-printed patient-specific surgical implants for craniomaxillofacial reconstruction. The approach consists of three parts: First, an easy-to-use design module is developed using Solidworks® software, which helps surgeons to design the implants and the axillary fixtures for surgery. Design engineers can then carry out the detailed design and use finite-element modeling (FEM) to optimize the design. Second, the fabrication process is carried out in three steps: ① testing the quality of the powder; ② setting up the appropriate process parameters and running the 3D printing process; and ③ conducting post-processing treatments (i.e., heat and surface treatments) to ensure the quality and performance of the implant. Third, the operation begins after the final checking of the implant and sterilization. After the surgery, postoperative rehabilitation follow-up can be carried out using our patient tracking software. Following this systematic approach, we have successfully conducted a total of 41 surgical cases. 3D-printed patient-specific implants have a number of advantages; in particular, their use reduces surgery time and shortens patient recovery time. Moreover, the presented approach helps to ensure implant quality

    Value of Immediate Heart Rate Alteration From Supine to Upright in Differential Diagnosis Between Vasovagal Syncope and Postural Tachycardia Syndrome in Children

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    Objectives: To explore the predictive value of immediate heart rate alteration from supine to upright in the differential diagnosis between vasovagal syncope (VVS) and postural tachycardia syndrome (POTS) in children.Materials and Methods: A total of 76 pediatric outpatients or inpatients who visited the Peking University First Hospital from July 2016 to November 2017 were recruited in the study. Among them, 52 patients were diagnosed with VVS and 24 patients were diagnosed with POTS. The differential diagnostic value of acceleration index (AI) and 30/15 ratio was evaluated by the receiver operating characteristic (ROC) curve. An external validation test was performed in another 46 patients.Results: Compared with the cases in the VVS group, patients in the POTS group had a significantly increased AI but a decreased 30/15 ratio (33.495 ± 8.472 vs. 23.440 ± 8.693, p < 0.001; 0.962 ± 0.067 vs. 1.025 ± 0.084, p = 0.002; respectively). The ROC curves showed that AI and 30/15 ratio were useful for differentiating POTS from VVS. A cut-off value of AI set at 28.180 yielded a sensitivity of 79.2% and a specificity of 73.1%. A cut-off value of 30/15 ratio set at 1.025 yielded a sensitivity of 87.5% and a specificity of 61.5%. A combined use of these two indices improved the sensitivity to 95.8% when either AI or 30/15 was used, and specificity to 80.8% with the use of both AI and 30/15 at the same diagnosis. The external validation test showed that the positive and negative predictive values of the AI and 30/15 ratio were 77.3 and 79.2%, and 72.0 and 81.0%, respectively. The positive predictive value increased to 87.5% when both the AI and 30/15 ratio cut-off values were used together.Conclusions: The AI and 30/15 ratio, which are easy to perform and non-invasive, have proper sensitivity and specificity to differentiate patients with POTS from those with VVS. The combination of these two indices significantly improves the predictive value

    Remarkable nucleation and growth of ultrafine particles from vehicular exhaust

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    High levels of ultrafine particles (UFPs; diameter of less than 50 nm) are frequently produced from new particle formation under urban conditions, with profound implications on human health, weather, and climate. However, the fundamental mechanisms of new particle formation remain elusive, and few experimental studies have realistically replicated the relevant atmospheric conditions. Previous experimental studies simulated oxidation of one compound or a mixture of a few compounds, and extrapolation of the laboratory results to chemically complex air was uncertain. Here, we show striking formation of UFPs in urban air from combining ambient and chamber measurements. By capturing the ambient conditions (i.e., temperature, relative humidity, sunlight, and the types and abundances of chemical species), we elucidate the roles of existing particles, photochemistry, and synergy of multipollutants in new particle formation. Aerosol nucleation in urban air is limited by existing particles but negligibly by nitrogen oxides. Photooxidation of vehicular exhaust yields abundant precursors, and organics, rather than sulfuric acid or base species, dominate formation of UFPs under urban conditions. Recognition of this source of UFPs is essential to assessing their impacts and developing mitigation policies. Our results imply that reduction of primary particles or removal of existing particles without simultaneously limiting organics from automobile emissions is ineffective and can even exacerbate this problem

    DNA methylation age is associated with an altered hemostatic profile in a multi-ethnic meta-analysis

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    Many hemostatic factors are associated with age and age-related diseases; however, much remains unknown about the biological mechanisms linking aging and hemostatic factors. DNA methylation is a novel means by which to assess epigenetic aging, which is a measure of age and the aging processes as determined by altered epigenetic states. We used a meta-analysis approach to examine the association between measures of epigenetic aging and hemostatic factors, as well as a clotting time measure. For fibrinogen, we performed European and African ancestry–specific meta-analyses which were then combined via a random effects meta-analysis. For all other measures we could not estimate ancestry-specific effects and used a single fixed effects meta-analysis. We found that 1-year higher extrinsic epigenetic age as compared with chronological age was associated with higher fibrinogen (0.004 g/L/y; 95% confidence interval, 0.001-0.007; P 5 .01) and plasminogen activator inhibitor 1 (PAI-1; 0.13 U/mL/y; 95% confidence interval, 0.07-0.20; P 5 6.6 3 1025) concentrations, as well as lower activated partial thromboplastin time, a measure of clotting time. We replicated PAI-1 associations using an independent cohort. To further elucidate potential functional mechanisms, we associated epigenetic aging with expression levels of the PAI-1 protein encoding gene (SERPINE1) and the 3 fibrinogen subunit-encoding genes (FGA, FGG, and FGB) in both peripheral blood and aorta intima-media samples. We observed associations between accelerated epigenetic aging and transcription of FGG in both tissues. Collectively, our results indicate that accelerated epigenetic aging is associated with a procoagulation hemostatic profile, and that epigenetic aging may regulate hemostasis in part via gene transcription

    Advances in Biological Control and Resistance Genes of Brassicaceae Clubroot Disease-The Study Case of China

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    Clubroot disease is a soil-borne disease caused by Plasmodiophora brassicae. It occurs in cruciferous crops exclusively, and causes serious damage to the economic value of cruciferous crops worldwide. Although different measures have been taken to prevent the spread of clubroot disease, the most fundamental and effective way is to explore and use disease-resistance genes to breed resistant varieties. However, the resistance level of plant hosts is influenced both by environment and pathogen race. In this work, we described clubroot disease in terms of discovery and current distribution, life cycle, and race identification systems; in particular, we summarized recent progress on clubroot control methods and breeding practices for resistant cultivars. With the knowledge of these identified resistance loci and R genes, we discussed feasible strategies for disease-resistance breeding in the future
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