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A collagen thin film-based bioimpedance sensor for cell proliferation rate assessment
Masoomeh Ashoorirad
Rasool Baghbani

Masoomeh Ashoorirad

and 4 more

May 14, 2021
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.
Ichthyosis and Multiple Sclerosis: A case report
Mehri  Salari
Masoud Etemadifar

Mehri Salari

and 3 more

May 14, 2021
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 as critical pioneers and engineers in alpine ecosystems across the Tib...
Yi Wang
Jian Sun

Yi Wang

and 4 more

May 14, 2021
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.
Acute Cholecystitis due to a gall bladder torsion: A case report
Dhafer Hadded
MERYAM MESBAHI

Dhafer Hadded

and 6 more

May 14, 2021
Gallbladder torsion is an unusual cause of an acute abdomen that can be mortal. It mimicks commonly acute cholecystitis. Its diagnosis is challenging for surgeons. Once it is suspected, prompt surgical treatment must be carried out, which is detorsion with cholecystectomy.
Psychological hesitance and myths related to COVID-19 vaccine is a hindrance in vacci...
Dr. Noor Ul Ain

Dr. Noor Ul Ain

and 2 more

May 14, 2021
The entire world is dealing with this pandemic of COVID-19 since December 2019. And several variants of this SARS-COV2 virus have occurred and they have more impact on the increase in the mortality rate and it has now increased to more than 5 percent up till now which is quite an alarming state. But despite this, every day increasing mortality rate the vaccine which is now available for use is not considered to be effective by the general population due to their self-created myths and this leads them to be reluctant to the vaccine. And that's why the vaccination process is still far slow as we know that the number of cases is getting increased day by day the immunization by the vaccine is much important to cope up with this challenging pandemic. There is a need to avoid the psychological considerations for the vaccination because vaccine provision is important to provide the maximum number of individuals with the vaccine so the more complex states of this variant form of viral infection could be deal with in a more sophisticated manner.
Comparison of ambulance usage characteristics in children between the pre-pandemic an...
Eyüp Sarı
İshak Şan

Eyüp Sarı

and 3 more

May 14, 2021
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.
On the relationship between mechanical energy rate and heat dissipated rate during fa...
Rosa De Finis
Davide Palumbo

Rosa De Finis

and 2 more

May 14, 2021
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.
Spinal Cord Tumor Presenting with Abdominal Pain: A Case Report
Anood  Alassaf
Rana  Al Shami

Anood Alassaf

and 5 more

May 13, 2021
Three years old boy presented with recurrent severe abdominal pain. He was treated for constipation and the pain resolved. Later he developed a limitation of neck movements. Investigations revealed a spinal cord mass. After surgical resection, histopathology confirmed pilocytic astrocytoma.
A note to further explain the mechanism of turbulent flow drag reduction by polymer f...
Xin Zhang
Xiaodong Dai

Xin Zhang

and 7 more

May 13, 2021
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.
A newborn with Aortico-left Ventricular Tunnel mimicking Sinus of Valsalva Aneurysm
SENAY AKBAY
Filiz EKICI

SENAY AKBAY

and 5 more

May 13, 2021
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.
Prenatally Diagnosed Left Atrial Appendage Aneurysm with Various Postnatal Imaging In...
Takeshi Sasaki
Yuki Kawasaki

Takeshi Sasaki

and 8 more

May 13, 2021
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 in neonatal Marf...
Sathish Chikkabyrappa
Kathryn Virk

Sathish Chikkabyrappa

and 5 more

May 13, 2021
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.
Bronchoscopic evaluation of children less than 5 years old with stridor
Kaustubh Mohite
Mahesh Mohite

Kaustubh Mohite

and 1 more

May 13, 2021
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.
Soil Water Stress Overrides the Boosting Effect of iWUE from Rising CO2 and temperatu...
Guodong Jia
Lixin Chen

Guodong Jia

and 3 more

May 13, 2021
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.
SARS-CoV-2 RNA stability in saliva and dry swabs for storage and transport at ambient...
Alonzo Alfaro-Núñez
Stephanie Crone

Alonzo Alfaro-Núñez

and 9 more

May 13, 2021
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.
What dermatologists should communicate
Dr. Carolina Diamandis

Dr. Carolina Diamandis

and 2 more

May 13, 2021
In the case of a suspicious skin mole, the question always arises as to whether it is benign or malignant. Is it a harmless mole, a capillary malformation or a basal cell carcinoma, squamous cell carcinoma or even a melanoma? Often the nevus can already be assessed by a close examination of the lesion and a few questions regarding its development. But most important: the patients need to be informed about their condition in a simple but professional way.
Evaluation of Single-use Tangential Flow Filtration Technology for Purification of Ac...
Seyed Pouria Motevalian
Jonathan Steen

Seyed Pouria Motevalian

and 7 more

May 13, 2021
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.
On the fatigue notch sensitivity of Ti6Al4V specimens with α+β microstructure produce...
Antonio Cutolo
Chola Elangeswaran

Antonio Cutolo

and 3 more

May 13, 2021
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.
Unintentional overdosing of ponatinib in a patient with chronic phase chronic myeloid...
George Nesr
Giorgia Francesconi

George Nesr

and 2 more

May 13, 2021
Unintentional overdosing of ponatinib in a patient with chronic phase chronic myeloid leukaemia
Impacts of Abrupt Climatic Changes on Flood Susceptibility in Northern Sindh and Sout...
Awais  Munir
Asad Ghufran

Awais Munir

and 5 more

May 13, 2021
Among all other disasters floods are the most destructive and common natural hazards. It not only endangers people’s lives, land, and wealth but also destroys a country’s economy. As a result, identifying flood-susceptible areas have significant importance for flood risk management as well as early disaster management plan. The main aim of this study is to classify flood susceptible areas using a frequency ratio model. The ten (10) conditioning factors including aspect, profile curvature, Elevation, slope, Normalized Difference Vegetation Index NDVI, Normalized Difference Soil Index NDSI, distance from road, distance from river, land use/land cover LULC, and rainfall were included. Total 230 flood location points were used to create the flood inventory map. The data was split into two datasets at random, with 70 percent (161 flood points) being used for preparation and the remaining 30 percent (69 flood points) being used for validation. The flood vulnerability map was divided into five zones, very low (19.73%), low (20.37%), moderate (20.37%), high (19.88%), and very high (19.62 %). District Jacobabad has high susceptible land as compare to other districts of the study area. This region is highly sensitive and has very low adaptive capability. Pakistan’s share in Greenhouse gas emissions is relatively very low, but it is the most affected and vulnerable country by the impacts of climate change. Finally, the area under the ROC curve AUC was used to develop the presentation and prediction score, which yielded satisfactory results of 77.4%. The findings of this paper would be useful to planners, decision-makers, and future development programs in Pakistan.
Experimental and ReaxFF-based molecular dynamics studies of the reaction of oxygen wi...
Neng Tao
Yuan Cheng

Neng Tao

and 6 more

May 13, 2021
The cis-1,1,1,4,4,4-hexafluoro-2-butene (DR-2 or HFO-1336mzz(Z)) is a novel environmentally friendly working fluid with appropriate physicochemical characteristics. The present work firstly investigates decomposition mechanism and thermal stability of DR-2 under the atmosphere containing oxygen (O2) and high temperature experimentally. The oxidative degradation features of DR-2 were explored at the temperature of 473-1073 K and the products were monitored by GC-MS and IC. The experimental and ReaxFF-based molecular dynamics results demonstrated the promotion effects of O2 on the DR-2 decomposition. The participation of O2 molecules was supposed to lower the initial thermal decomposition temperature by 240 K approximately and also would increase the number of products such as hydrogen fluoride (HF), but the enhancement effect was weakened by the increasing reaction temperature. The reasonable Arrhenius parameters calculated from the first-order kinetic analyses-based reactive molecular dynamics (RMD) simulations. Combined with density functional theory, the pathways of initial oxidation decomposition product firstly observed in the experimental and RMD simulations were proposed in this study. These results may pave the way for further study of DR-2 as a working fluid with lower global warming potential.
Host-pathogen-environment interactions determine survival outcomes of adult sockeye s...
Amy Teffer
Scott Hinch

Amy Teffer

and 9 more

May 13, 2021
Incorporating host-pathogen(s)-environment axes into management and conservation planning is critical to preserving species in a warming climate. However, the role pathogens play in host stress resilience remains largely unexplored in wild animal populations. We experimentally characterized how independent and cumulative stressors (fisheries handling, high water temperature) and natural infections affected the health and longevity of released wild adult sockeye salmon (Oncorhynchus nerka) in British Columbia, Canada. Returning adults were collected before and after entering the Fraser River, yielding marine- and river-collected groups, respectively. Fish were exposed to a mild (seine) or severe (gill net) fishery treatment at collection, and then held in circulating freshwater tanks for up to four weeks at historical (14°C) or projected migration temperatures (18°C). Using weekly nonlethal gill biopsies and high-throughput qPCR, we quantified loads of up to 46 pathogens with host stress and immune gene expression. Marine-captured fish had less severe infections than river-captured fish, a short migration distance (100 km, 5-7 d) that produced profound infection differences. At 14°C, river-collected fish survived 1-2 weeks less than marine-collected fish. All fish held at 18°C died within 4 weeks unless they experienced minimal handling. Gene expression correlated with infections in river-collected fish, while marine-collected fish were more stressor-responsive. Cumulative stressors were detrimental regardless of infections or collection location, likely due to extreme physiological disturbance. Because river-derived infections correlated with single stressor responses, river entry likely decreases stressor resilience of adult salmon by altering both physiological status and pathogen burdens, which redirect host responses toward disease resistance.
Challenges in Studying Steric Interactions in Highly Strained Perhalogenated Alkanes...
Luís Simões
RODRIGO CORMANICH

Luís Simões

and 1 more

May 13, 2021
The decomposition of the molecular total energy in their hyperconjugative, steric and electrostatic effects can lead to interesting interpretations about the stereoelectronic effects that govern their geometry and properties. In this work, we have studied homologous series of perfluoroalkanes, perchloroalkanes, perfluorosilanes and perchlorosilanes, and all molecules have preference for helical geometries. According to Natural Bond Orbitals (NBO) calculations, the silanes have their helical geometry stabilised by hyperconjugative interactions, as well as the perfluoroalkanes. However, it was surprisingly difficult to disclose that steric interactions are ruling the helical geometry preference in perchloroalkanes by comparing the NBO analysis and the Quantum Theory of Atoms ins Molecules (QTAIM). Although perchloroalkanes have extremely intense steric interactions between Cl lone pairs, some of them were underestimated by the NBO analysis, which showed the opposite behaviour compared with QTAIM that indicates steric effects as the leading forces to helical geometry preference.
Stretch-driven microfluidic chip for nucleic acid detection
Xiang Li
Xiaoyu Zhao

Xiang Li

and 7 more

May 13, 2021
Molecular diagnosis is an essential means to detect pathogens. The portable nucleic acid detection chip has excellent prospects in places where medical resources are scarce, and it is also of research interest in the field of microfluidic chips. Here, the paper developed a new type of microfluidic chip for nucleic acid detection where stretching acts as the driving force. The sample entered the chip by applying capillary force. The strain valve was opened under the action of tensile force, and the spring pump generated the power to drive the fluid to flow to the detection chamber in a specific direction. The detection of COVID-19 was realized on the chip. The RT-LAMP amplification system was adopted to observe the liquid color in the detection chamber to decide whether the sample tested positive or negative qualitatively.
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