In this paper, a bioimpedance sensor used to measure the impedance behavior of the biological cells cultured on a scaffold of collagen thin films. The collagen thin films with different concentrations were created on a 1-hexadecanethiol modified surface of the interdigitated electrodes(IDEs). The mesenchymal stem cells(MSCs) and human umbilical vein endothelial cells(HUVECs) were cultured on the collagen thin films. The interaction and the proliferation rate of these cells were investigated by the microscopic, and bioimpedance approaches. Results showed that the MSCs, and HUVECs excellently attached to the collagen thin films. Impedance measurements of the cells cultured on the collagen thin film were performed by a Hioki IM3570 impedance analyzer at the frequency band of 10 kHz to 1MHz at 10 mV. Bioimpedance measurements showed that the proliferation rate of both MSCs, and HUVECs increased by decreasing the collagen thin films concentration. After 48 h, the differential impedances (ΔΖ ) of the MSCs cultured on the collagen thin layers with concentrations of 250μg/mL,500μg/mL , and 1000μg/mL measured 3.09Ω≤Δ≤48.03Ω, 2.62Ω≤Δ≤45.79Ω, and 1.9Ω≤Δ≤25.22Ω, respectively. Also, ΔΖ of the HUVECs obtained 27.3Ω≤Δ≤39.2Ω, 8.25Ω≤Δ≤18.43Ω, and 0.96Ω≤Δ≤9.6Ω for the corresponding frequency band and collagen thin films concentrations.
Abstract Concurrent presentation of MS and congenital ichthyosis is extremely rare. In this study we present a case of a 27-year-old woman with congenital ichthyosis who presented with signs of multiple sclerosis. This concurrence may provide insight into any common immunopathologic and genetic mechanisms.
Cushion plants are widely representative species of the alpine ecosystem due to their vital roles in the abiotic and biotic environments, ecological succession processes, and ecosystem engineering. Importantly, Cushion plants, such as Androsace L. and Arenaria L., can be regarded as critical pioneers of ecosystem health, restoration and sustainability across the Tibetan Plateau because these plants (i) exhibit tenacious vitality, regulate regional climates, substrates and soil nutrients and keep warmth in extreme regions; (ii) facilitate relationships with surrounding and maintain the diversity of above- and below-ground communities; and (iii) have high sensitivity to environmental changes, which can indicate grassland ecosystem health and resilience in the context of global change.
Aim: A pandemic is an epidemic of an infectious disease that has spread across a large region of the world and affects many people. In this study, it was aimed to evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on ambulance use by pediatric patients in ……………., Turkey. Materials and Methods: This retrospective study was conducted in the spring-summer of 2019 and 2020. The electronic medical records of pediatric patients who were transported to the hospital by ambulance were analyzed. Results: It was determined that 49.6% of the 23,201 patients included in the study were transported during the pandemic period. Male gender was higher in both the pandemic and pre-pandemic periods, there was no difference in terms of average age. The rate of forensic cases and refugee patients increased, while that of emergency patients decreased. Both the arrival at the scene time and intervention time were prolonged. Medical cause was the most common cause of emergency calls in both years, however, it increased significantly in 2020. The decrease in cases of traffic accidents, suicides, and other accidents was statistically significant. In the pandemic period, total rate of COVID-19 infection and suspicion was 29.7%. Most of the patients had been referred to a public hospital. Conclusion: It was found that most of the ambulances were used for transporting patients with minor illnesses that did not require immediate medical attention.
This work deals with the analysis in the frequency domain of the temperature signal and mechanical energy rate of C45 steel under two different fatigue stepwise loading series at stress ratios of 0.1 and -1. It was first investigated the energy distribution among the harmonic components of the signals to understand possible variations caused by a different stress ratio. In addition, the second amplitude harmonic (SAH) of heat dissipated and mechanical energy rates have been considered in the analysis and their relationship was investigated. It has been shown as it depends only on the material, hence it is valid whatever the kind of the test is without any assumption on the energy supplied to the material or material hysteresis loop stabilisation. The adopted approach allows the analysis of intrinsic dissipations by means of rapid, full-field and contactless techniques without any specific requirement on loading condition or temperature signal stabilisation.
In our previous work regarding the mechanism of drag reduction and degradation by flexible linear polymers, we proposed a correlation based on the Fourier series to predict the drag reduction and its degradation, where a phase angle was involved, but the physical meaning for the correlation especially of the employed phase angle was not clear, which is however important for reasonable explanation of the drag reduction mechanism over flexible linear polymers. This letter aims to clarify this issue. We use several steps of deduction from the viscoelastic theory, and conclude that the Fourier series employed to predict the drag reduction and its degradation is due to viscoelastic property of drag-reducing polymer solution, and the phase angle represents the hysteresis of polymer in turbulent flow. Besides, our new view of drag reduction by flexible polymers can also explain why a maximum drag reduction in rotational flow appears before degradation happens.
Aortico-left ventricular tunnel (ALVT) is a rare congenital cardiac anomaly and constitues of less than 0.1% of all congenital cardiac defects (1). ALVT is described as an abnormal connection between the ascending aorta and the left ventricul which originates commonly above the right sinus of valsalva. Most patients are diagnosed with an ALVT during early infancy (2). Although transthoracic echocardiography (TTE) is more effective in diagnosis of ALVT, misdiagnosis rate was 17.1% (3). Sinus of valsalva aneurysm (SVA) is frequently confused with ALVT (3). We report a term female newborn with SVA in echocardiographic examination but in surgery she was diagnosed with ALVT.
A congenital left atrial appendage aneurysm (LAAA) is a rare cardiac malformation that is usually diagnosed in adulthood. It is rarely diagnosed prenatally. In most cases, surgical resection is recommended soon after the diagnosis has been made due to the risk of arrhythmia and thrombotic events. The present report describes a case of LAAA which was prenatally diagnosed and was asymptomatic postnatally. Imaging revealed the relation of the cardiac and airway structures around the LAAA in detail. The patient underwent surgical resection of the LAAA successfully at 7 months of age and is currently healthy at 5 years of age.
Congenital Pseudoaneurysm of the mitral aortic intervalvular fibrosa (P-MAIVF) is extremely rare condition. We report a case of neonatal Marfan syndrome with unique and rare diagnosis of case of congenital pseudoaneurysm of the mitral aortic intervalvular fibrosa, where the transthoracic echocardiogram and computed tomography images described a congenital pseudoaneurysm of the mitral aortic intervalvular fibrosa.
Background: Stridor is a harsh, vibratory sound with variable pitch which is caused by partial obstruction of airway that results in turbulent airflow. It is mainly due to anatomic deformities in the infantile age group. However, various acquired conditions affecting upper airway may also cause stridor. Here, we evaluated 87 cases of stridor using Flexible bronchoscope in order to determine the cause of stridor. Objective: To determine the clinical characteristics, Flexible bronchoscopy findings and clinical correlation in children admitted in our hospital with complains of stridor. Design: Retrospective observational study. Setting: Single center study conducted in Amrut medical foundation. 87 children aged less than 5 years with a clinical complains of stridor were included in the study and Flexible bronchoscopy was performed. The findings were analyzed and results were reported. Results: A total of 87 children with stridor were enrolled in the study and Flexible Bronchoscopy was performed in them. Of these, 68 children had an abnormal bronchoscopy finding. Laryngomalacia was the commonest cause of stridor observed followed by subglottic stenosis and tracheomalacia. Cough was the commonest presenting symptom associated with stridor and tachypnea was the commonest clinical sign observed in these children. Conclusion: Flexible bronchoscopy plays an important role in diagnosing the exact cause of stridor in pediatric age group. Key words: Stridor, Flexible Bronchoscopy, Laryngomalacia.
Background Congenital GBM (cGBM), presenting prenatally or within the first months of life, is among the rarest type of congenital brain tumor, with approximately 120 cases reported. Due to its infrequent occurrence, few studies have focused on the molecular and genetic aspects of this tumor, and the mutational events involved in the pathogenesis and progression of cGBM still remains poorly understood. This study aimed to investigate molecular alterations, with a potential prognostic marker and therapeutic target in cGBM using the next-generation sequencing (NGS) strategy. Methods We selected seven tumor samples from patients diagnosed with cGBM and treated at Pediatric Oncology Institute-GRAACC/UNIFESP. NGS was performed to identify somatic genetic variants in tumor samples using the Oncomine Childhood Cancer Research Assay® panel, from ThermoFisher Scientific®, designed specifically for pediatric neoplasms. Results Of all seven patients analyzed, three patients exhibited tumors with genetic variants, which include two pathogenic variants in NF1 and SUZ12 genes that have not been reported in cGBM yet, an increase in the number of copies of ALK gene, and two gene fusions, PPP1CB-ALK and TPM3-NTRK1. Also, none of the cases showed variants in H3F3A, TP53 and ATRX genes, alterations which are frequently seen in pediatric and adolescent GBM. Conclusions Our results suggest that cGBM may comprise a unique tumor entity and alterations in ALK and NTRK genes provide a potential target for therapy. Therefore, identification of genetic variants in cGBM is highly relevant in order to define prognosis and therapeutic strategies.
The counteractive influence of atmospheric CO2 enrichment and drought stress on tree growth results in great uncertainty in growth patterns of planted forests in cold semi-arid regions. We used tree-ring chronology and carbon isotope analysis to track ecophysiological processes in reaction to environmental factors over the past four decades of Populus simonii plantations in cold semi-arid areas in northern China. Our results showed that the boosting effect of the rising atmospheric CO2 concentration (Ca) on iWUE and stem growth was more significant in declined stands. However, the increased iWUE did not negate tree dieback when water stress was present. Therefore, the BAI and iWUE deviation of different health status trees started from a very early age. Climatic factors showed limited influences on the stem growth of the poplar plantations. The inaccessibility of deep soil water due to site-specific soil conditions rendered the trees exposed to chronic soil water stress and constrained stomatal conductance and reduced the CO2 fertilization effect. Consequently, these stands experienced a lower stem growth rate. In summary, we suggest that soil moisture conditions the iWUE and growth sensitivity to global warming and thus portrays site-specific decline episodes of different degrees in drought-prone areas.
During the current COVID-19 pandemic, different methods have been used to evaluate patients suspected with infection of SARS-CoV-2. In this study, we evaluate the longevity of saliva and dry swab samples to retain SARS-CoV-2 for storage and transport at different environmental settings. Our results show that at ambient temperature of 20°C, SARS-CoV-2 RNA remains stable for up to 9 days giving a long span of time for transport and storage without compromising clinical results. Additionally, this study demonstrates that saliva and dry swabs specimens can also be stored at -20°C and +4°C for up to 26 days without affecting RT-qPCR results. Our data is relevant for low-and middle-income countries, which have limited access to rapid refrigerated transport and storage of samples representing an economical alternative. Finally, our study demonstrates that dry swabs provide clear advantages over using transport medium.
Over the past decade, single-use tangential flow filtration (TFF) technologies have emerged to reduce system preparation time, promote fast and flexible product change over, and ultimately shorten process development and manufacturing time/cost. In this study, the performance of a recently developed Pellicon® single-use TFF capsule was compared against traditional Pellicon® cassette by assessing TFF process performance (such as flux, residuals clearance, and yield) and post-purification product attributes (such as concentration and mass-weighted average molecular weight). Good scaling was shown by comparing process performance and product attributes across different scales and formats. Additionally, similar TFF process performance and post-purification product attributes were observed for the single-use capsule compared to the reusable TFF cassettes. The capsule requires a smaller flush than the cassette, and it is easier to use since it does not require a compression holder or pre-sanitization. The results provide insight into the application of the single-use TFF capsule and scalability of TFF processes for the purification of conjugate vaccines.
Laser powder bed fusion (L-PBF) is an additive manufacturing (AM) process which offers several advantages over conventional manufacturing techniques, including material savings and design possibilities. For these reasons several industrial sectors such as biomedical, aerospace and automotive, are considering L-PBF for customized parts production. Among the processable material palette, Ti6Al4V gained increasing interest due to the high specific strength, and stiffness, and excellent bio-compatibility, and corrosion resistance. However, to include L-PBF Ti6Al4V parts in load bearing applications it is important to properly understand the mechanical properties of AM’ed materials with a specific focus on fatigue behaviour. In this study the fatigue notch sensitivity of Ti6Al4V L-PBF manufactured specimens is investigated in depth. Samples with different notches were subjected to stress relieving heat treatment to generate a fine α+β microstructure. The results were used to define a relation between the perturbed stress field generated by the geometrical discontinuity, the microstructure size and the notch sensitivity. Moreover, the critical distance has been calculated using the theory of critical distance formulated with the line method (LM). The estimated value were adopted to predict fatigue properties of notched components with different notch radii.