bluuebunny/crossref_metadata_2025 huggingface dataset:
On the existence of global solution of the system of equations of liquid movement in porous medium
Authors: Tokareva Margarita , Papin Alexander
Published: February 2021

The initial-boundary value problem for the system of one-dimensional isothermal motion of viscous liquid in deformable viscous porous medium is considered. Local theorem of existence and uniqueness of problem is proved in case of compressible liquid. In case of incompressible liquid the theorem of global solvability in time is proved in Holder classes. A feature of the model of fluid filtration in a porous medium considered in this paper is the inclusion of the mobility of the solid skeleton and its poroelastiс properties. The transition from Euler variables to Lagrangian variables is used in the proof of the theorems.
The adoption of sustainable development indicators in agricultural practices in the Gharb region (Morocco)
Authors: Chbika Sami , Aouane El Mahjoub
Published: February 2021

Many studies were carried out in Morocco to show that the dynamics of the market gardening is characterized by frequent use and often uncontrolled use of chemical inputs to the detriment of the preservation of natural resources, the health of consumers and the producers themselves. This reality, calls for appropriate structural actions, based on the levels of sustainability of the sector. The IDEA method (Farm Sustainability Indicators) is one way of giving practical expression to the concept of sustainable farms. Based on 40 sustainability indicators covering the three dimensions of sustainability: agro-ecological, socio- territorial, and economic. Using the IDEA method, we conducted this research with a view to analyze the sustainability of market gardening exploitations in three rural communities: Mnasra, Sidi Mohamed Benmansour, and Benmansour. We conducted questionnaire interviews with 180 producers. The results obtained have generally shown that the market gardening farms in this region have low sustainability scores. The sustainability of farms is lowest on the socio-territorial scale due to the absence of product quality approaches, poor human development, and poor employment conditions and services. On the economic scale, the low viability stands out. The agro-ecological scale shows higher values due to the good organization of space and diversified systems.
The role of renewable energy sector in reducing unemployment: The Moroccan case
Authors: El Moummy Chama , Salmi Yahya , Baddih Hindou
Published: February 2021

The Covid-19 pandemic is putting the world into some very hard times and the labor market is currently experiencing a very significant shock. In Morocco, the unemployment rate has increased since the beginning of the crisis. In the other hand, the world is engaged in a sustainable path and Morocco has started some years ago the deployment of renewable energy sources. After the 2008 crisis, the emergence of the concept of “Green New Deal” has demonstrated the impact of environmental measures and strategies included in many countries recovery plans, on boosting the economy. The objective of this article is to highlight the benefits of green economic recovery policies, on the employment in Morocco, especially for the renewable energy sector. The causality between renewable energy consumption and unemployment will be tested using the VAR model, the Johansen co-integration test, and the Granger causality test, for the period 1990-2017. Our results suggest that there is causality running from renewable energy consumption to unemployment. In fact, renewable energy sector can contribute to reduce the employment rate in Morocco. Investments in the sector can then be made to create jobs, particularly after the Covid-19 pandemic, that caused many jobs losses.
A contribution to the therapeutic valorization of Moroccan Cistus Ladanifer L
Authors: Adadi Imad , El Aydi Rachida , El Ibaoui Hamid , Bentayeb Amar
Published: February 2021

Cistus ladanifer L. is a medicinal shrub traditionally used against several diseases. The present study was performed for trying to enrich the potentialities of this plant by evaluating the possible analgaesic effect of aqueous extract of Cistus. ladanifer (AECL) and oral formulation prepared from AECL. The analgaesic effect was tested using the acetic acid induces writhing and formalin models. The results showed that both aqueous extract and herbal syrup induced a significant analgaesic activity in the two nociceptive tests. Moreover, the oral formulation produced the potent analgaesic effect. We conclude from the results of this work that the Moroccan C. ladanifer L orally administrated to mice possesses an efficient analgaesic effect, and may will contribute to developing a natural analgaesic drug.
Aerial Target Tracking Based on Frequency-Domain Gabor Filters and Correlation Filters under Complex Interference Environment
Authors: Yang Xi , Li Shaoyi , Wang Xiaotian , Zhang Kai , Yan Jie
Published: February 2021

Aerial infrared target automatic tracking technology is the core technology of the photoelectric countermeasure system of infrared imaging missiles. Aiming at challenging conditions of complex battlefield environment, large scale change of air target, infrared interference partial occlusion and so on, we propose a new correlation filtering algorithm based on Gabor filtering features in the frequency domain for aerial infrared target tracking. This algorithm constructs a set of frequency-domain Gabor filters, which extracts frequency-domain Gabor filtering(GF) features of the target image block and reduces dimension fusion, thereby effectively suppressing background noise and highlighting target texture information. According to the characteristics and variation law of spectrum energy distribution, the eigenvectors of target spectrum scale are extracted to improve the accuracy of target scale information estimation. High-confidence patches are used to track the reliable part of the target, and the energy distribution of the tracking box is calculated to predict the occluded part of the target simultaneously. This method provides more target information and improves the robustness of the algorithm in case of reappearance of the occluded target. Compared with other tracking algorithms, the average accuracy of the proposed algorithm was improved by 15.2%, and the frame frequency reached above 110 Hz.
A Tolerant Detection Method for Estimating Robust Signal Subspace with Horizontal Arrays in Uncertain Shallow Ocean Environment
Authors: Wang Xuan , Sun Chao , Xiang Longfeng , Li Mingyang
Published: February 2021

The environmental parameters are usually uncertain in complex shallow ocean environment and restrict the performance of the matching model-like method. Therefore, we need a more tolerant detection method for detecting underwater targets in the uncertain shallow ocean environment. The previous mode-subspace detection method has the characteristics of both high performance and robustness. However, the robust mode-subspace detector is suitable for vertical arrays and its performance is limited by shallow ocean environment. Therefore, we propose the tolerant detection method for estimating the robust signal subspace with horizontal arrays. We estimate the robust signal subspace by bringing uncertain parameters into the observation matrix of a horizontal array. Combined with the robust signal subspace estimation, we propose a subspace detector that tolerates uncertain parameters. The results on simulation in a uncertain shallow ocean environment show that the detector we proposed has a high average detection capability and a certain tolerance for uncertain parameters.
Research on Calculation Method for Acoustic Scattering of Helicopter Noise
Authors: Fan Feng , Cao Yaxiong , Jiang Lusheng , Lin Yongfeng
Published: February 2021

A new calculation method of helicopter rotor/fuselage acoustic scattering is developed. Firstly, a CFD analysis model is developed to simulate flow field of the rotor, which is based on the motional embedded grid system and RANS equations, and provides aerodynamic data for rotor noise calculation. Then, FW-H equations are employed to calculate the aeroacoustic characteristics of isolated rotor, and G 1A formulas are applied to calculate the rotor acoustic gradient to provide boundary condition for acoustic scattering. Based on these, the time-domain equivalent source method is applied to calculate acoustic scatter field, and the total acoustic field that considered the fuselage scatter is superposed by isolated rotor acoustics and the scatter one. Finally, the numerical simulations of helicopter main-rotor/fuselage and tail-rotor/fuselage scatter effect are conducted by using the developed models. The results indicate that the helicopter fuselage has important scatter effect on the high frequency acoustics of main rotor and tail rotor, and the acoustic scatter effect become more obvious with the smaller space between the main rotor (tail rotor) and fuselage.
Study on Early Warning Method of Cylinder Block's Off-Center Position and Swing Failure for 50 MW Steam Turbine
Authors: Shi Jiakui , Yao Kun , Fu Junfeng , Ju Guoteng , Li Fengjun , Wan Jie
Published: February 2021

Due to the special structure of the cylinder block, there is an off-center position and swing fault in the process of start-up and operation of the 50 MW extraction unit. Moreover, the lack of effective monitoring and early warning means seriously affects the safety of the unit operation. Therefore, it is very important to forewarn the fault of cylinder off-center position and swing. First of all, through the design of cylinder block offset amplifying mechanism for fault monitoring, the data of eccentric swing required for establishing mathematical model is obtained. Then, neural network is selected for data-driven modeling, two time series prediction models are obtained, and the influence of input and output parameters on the prediction accuracy is studied. Finally, by selecting reasonable early warning value and decision rules, an effective early warning of off-center position and swing fault is realized, and a monitoring device for real-time monitoring and fault early warning is developed. The actual application effect shows that this early warning method has important engineering value to avoid equipment damage caused by the swing fault for 50 MW unit.
Air Combat Maneuver Decision Based on Reinforcement Genetic Algorithm
Authors: Xie Jianfeng , Yang Qiming , Dai Shuling , Wang Wanyang , Zhang Jiandong
Published: February 2021

With the continuous development of UAV technology, the trend of using UAV in the military battlefield is increasingly obvious, but the autonomous air combat capability of UAV needs to be further improved. The air combat maneuvering decision is the key link to realize the UAV autonomous air combat, and the genetic algorithm has good robustness and global searching ability which is suitable for solving large-scale optimization problems. This paper uses an improved genetic algorithm to model UAV air combat maneuvering decisions. Based on engineering application requirements, a typical simulation test scenario is established. The simulation results show that the air combat maneuvering decision model based on reinforcement genetic algorithm in this paper can obtain the correct maneuvering decision sequence and gain a position advantage in combat.
Dialysepatienten als Flugpassagiere
Authors: Kammerl Martin
Published: February 2021

Nierenersatztherapie beeinflusst den Alltag der betroffenen Patienten deutlich. Trotzdem können verschiedene Reiseangebote wahrgenommen werden. Bei Flugreisen sollten Dialysepatienten bereits bei der Reisevorbereitung einige organisatorische Aspekte berücksichtigen, Anpassungen der Medikation können erforderlich werden, während des Fluges können Notfälle im Zusammenhang mit der Dialysebehandlung auftreten. Diese Besonderheiten bei Dialysepatienten als Flugpassagiere werden genauer dargestellt.
Differential Diagnosis of Acute Scrotum in Childhood and Adolescence with High-Resolution Duplex Sonography
Authors: Deeg Karl-Heinz
Published: February 2021

Acute testicular pain in childhood can be caused by testicular torsion, torsion of the appendix testis, or epididymo-orchitis. Quick and reliable diagnosis is essential for determining the further course of action (surgery or conservative approach). The diagnostic tool of choice is high-resolution sonography with a linear transducer (> 10 MHz) combined with color and spectral Doppler sonography. The Doppler device settings should include a low pulse repetition frequency (< 4 cm/s), a low wall filter (< 100 Hz), and adequate gain. Comparison with the unaffected healthy testis is essential. The most important of the three diseases is torsion of the spermatic cord because it requires immediate surgical intervention and detorsion. The affected testis is enlarged and has an inhomogeneous echotexture with hypoechoic and hyperechoic areas as well as an associated hydrocele. In testicular torsion, color Doppler shows reduced or absent intratesticular vessels in comparison with the healthy contralateral testis. Spectral Doppler shows decreased flow velocities especially during diastole in intratesticular arteries and an increased resistance index. The investigation should always include imaging of the spermatic cord from the outer inguinal ring to the upper pole of the testis. In contrast to a normal finding, the vessels and the ductus deferens are not displayed as linear tubular structures but in form of a spiral twist. Ultrasound shows a target-like structure with multiple concentric rings. Color Doppler sonography shows the typical whirlpool sign. In torsion of the appendix testis, the appendix testis is enlarged in the groove between the testis and epididymis. The longitudinal diameter of the appendix testis can be greater than 5 mm. The echogenicity of the torsed appendage can vary between hypoechoic (acute torsion) and hyperechoic (prior torsion). An associated hydrocele of varying size is usually seen. Color Doppler sonography reveals a lack of perfusion of the enlarged appendix testis and increased vascularity of the testis and primarily the epididymis. Epididymo-orchitis is characterized by an enlarged epididymis and/or testis with inhomogeneous echogenicity (hypoechoic – hyperechoic). Color Doppler sonography shows increased vascularity in comparison with the unaffected testis. Spectral Doppler reveals increased diastolic flow velocities and a decreased resistance index. Idiopathic scrotal edema and an incarcerated inguinal hernia must be ruled out in the differential diagnosis.
NADA-Ohrakupunktur bei Geflüchteten
Authors: Wendling Ursula
Published: February 2021

Die NADA-Ohrakupunktur wird bereits seitden 1970er-Jahren eingesetzt, um die EntzugssymptomatikDrogen- und Alkoholabhängigerzu lindern. Durch ihre einfacheAnwendung und ihre vielfältige Wirkungwie Reduktion von Stress, Ängstlichkeit undvegetativen Beschwerden wie innere Unruheund Herzrasen weiteten sich die Einsatzbereicheder NADA-Akupunktur in den vergangenenJahrzehnten zunehmend aus. Sowird sie seit den 2000er-Jahren auch beiTraumatisierung durch Krieg, Flucht, Vertreibung,Gewalt und (Natur-)Katastrophen angewendet.Seit 2015 kommt NADA-Akupunkturauch bei Geflüchteten in Deutschlandzum Einsatz. Die Erfahrungen auseinem Stuttgarter Wohnheim für Geflüchtetezeigen die gute Akzeptanz und Wirksamkeitder Anwendung.
Homöopathie für Geflüchtete
Authors: Möller Maria
Published: February 2021

Das Asylbewerberleistungsgesetz schränktdie Behandlungsmöglichkeiten für Geflüchtetein Deutschland in den ersten 18 Monatenstark ein. Auch danach besteht kein Anspruchauf Sprachvermittler, und die finanziellenMöglichkeiten sind begrenzt. Zu einer homöopathischenBehandlung besteht keinZugang. Doch gerade bei traumatisiertenPatientInnen erweist sich ein ganzheitlicherAnsatz als hilfreich. Das Projekt „Homöopathiefür Flüchtlinge in Deutschland“ ermöglichtkörperlich und seelisch erkrankten Geflüchtetendaher eine homöopathische Behandlungunter Einbeziehung vonÜbersetzern. Die Erfahrungen mit diesemund anderen Projekten zeigen eine hohe Akzeptanzder ganzheitlichen Medizin bei denGeflüchteten und erfreuliche Erfolge in derBehandlung von PatientInnen mit akutenoder chronischen Traumafolgestörungen.
Rassismus im medizinischen Alltag – eine fragmentarische Reise
Authors: Windel Anne-Sophie
Published: February 2021

Alltäglicher Rassismus hat auch in Deutschlandzu einer intensiven gesellschaftlichenDiskussion geführt. Was bedeutet aber Rassismusfür den Arztberuf?Die Autorin spürt den subtileren Formen vonRassismus im medizinischen Alltag nach undhinterfragt dabei auch eigene Stereotype imKopf und das eigene Handeln.
Post-COVID-Syndrom: Behandlung von Residuen nach SARS-CoV-2-Infektionen mit Chinesischer Arzneimitteltherapie
Authors: Thede Christian
Published: February 2021

Bei anhaltend hohen Infektionsraten sind zunehmendviele Menschen von chronischen Residualzuständennach SARS-CoV-2-Infektionen betroffen. Es werden effektiveTherapiekonzepte der chinesischen Arzneimitteltherapiezur Behandlung der besonders häufigen respiratorischenund Fatigue-Symptomatik vorgestellt, unterbesonderer Berücksichtigung der Behandlung speziellerFormen von COVID-19-Folgezuständen als Dysharmoniedes Shaoyang mit Variationen des „Kleinen BupleurumDekokts“ (Xiao chai hu tang).
Homöopathie: Aconitum napellus nach akuter Traumatisierung
Authors: Pfanzelt Ingrid
Published: February 2021

Kausalität und Spannung bilden die „Essenz“ der Arznei Aconitum undcharakterisieren den psychischen Prozess eines Traumas
Aconitum in der Chinesischen Medizin
Authors: Wiebrecht Axel
Published: February 2021

Vom Pfeilgift zum sicheren Arzneimittel
COVID-19 in Egyptian Children: A Multicenter Study
Authors: Abdel Baki Amin , Zaky Samy , Hosny Hossam , Elassal Gehan , Abdelbary Akram , Said Ahmad , Kamal Ehab , Asem Noha , Ibrahim Hamdy , Eid Alaa , Amin Wagdy , El Badry Mohamed , Mossa Abdelmajeed , El-Raey Fathiya , Baghdady Shazly , Tahoon Marwa , Hassany Mohamed , Zaid Hala
Published: February 2021

Objective The novel coronavirus disease 2019 (COVID-19) has made its worldwide spread since its outbreak in December 2019. Limited information is available about the epidemiology and clinical characteristics of COVID-19, especially in Africa and Egypt.

Methods We aimed to study the clinical and epidemiological characteristics of COVID-19 in Egyptian children. This is an observational retrospective cohort study performed at two specialized COVID-19 isolation hospitals in Egypt. All admitted COVID-19 pediatric patients between March 20, 2020, and May 1, 2020, were included in the study.

Discussion This study included 40 COVID-19 confirmed cases (mean age, 9.4 years), 67.5% were male, 85% were asymptomatic, and 15% had mild symptoms. There were no confirmed severe or critically ill cases among the patients.

Conclusion COVID-19 runs in a benign course in Egyptian children with no mortality and no significant morbidity.
Machine learning techniques provide insight into materials with competing order parameters
Authors: Fore Meredith
Published: February 2021

Atomically disordered systems are extremely complicated to model, but a new probabilistic algorithm allows them to be quantitatively analyzed. This could lead to the discovery of new physics.
Diffusion temperature dependent microstructure and magnetic properties of TbHx grain boundary diffused Nd–Fe–B magnets
Authors: Zhao Yang , Feng Haibo , Li Anhua , Li Wei
Published: February 2021

Commercial N50 sintered Nd–Fe–B magnets were grain boundary diffusion (GBD) processed with TbHx powders. The diffusion temperature and time dependent microstructure and magnetic properties of the GBD processed magnets were investigated. High remanence and coercivity were obtained when the magnet was GBD processed at 875 °C for 14 h; the coercivity of the magnet increased from 12.57 kOe to 22.65 kOe. The relationships between microstructure and coercivity, remanence, and thermal stability of the GBD processed magnets were analyzed and discussed.
Anisotropic pyrochemical dry etching of fluorinated ethylene propylene induced by pre-irradiation with synchrotron radiation
Authors: Fujitani Kaito , Takeuchi Masaya , Haruyama Yuichi , Yamaguchi Akinobu , Utsumi Yuichi
Published: February 2021

Anisotropic pyrochemical micro-etching induced by synchrotron x-ray irradiation is developed as a microfabrication process for fluorinated ethylene propylene (FEP). X-ray irradiation is performed at room temperature, and the irradiation area is etched by heating in an oven. By measuring the irradiation area using Raman spectroscopy, the peak of the Raman spectrum is shown to decrease with an increasing irradiation dose. It is also observed that the etching can be performed at a heating temperature of around 200 °C while maintaining the chemical composition of the surface. The etching mechanism is speculated to be as follows: x-ray irradiation causes chain scission, which decreases the number-average degree of polymerization. The melting temperature of irradiated FEP decreases as the polymer chain length is decreased so that the irradiated area can be evaporated at low temperatures of post-heating. In this way, we demonstrate that anisotropic pyrochemical micro-etching of FEP proceeds only in the depth direction where x rays are absorbed. It is possible to avoid deterioration of the shape accuracy arising from thermal expansion during the transfer process of the mask pattern by separating pre-irradiation from post-heating. Through this method, it becomes possible to realize a high precision microstructure of FEP in a large area.
Cytoplasmic synthesis of endogenous
Alu
complementary DNA via reverse transcription and implications in age-related macular degeneration
Authors: Fukuda Shinichi , Varshney Akhil , Fowler Benjamin J. , Wang Shao-bin , Narendran Siddharth , Ambati Kameshwari , Yasuma Tetsuhiro , Magagnoli Joseph , Leung Hannah , Hirahara Shuichiro , Nagasaka Yosuke , Yasuma Reo , Apicella Ivana , Pereira Felipe , Makin Ryan D. , Magner Eamonn , Liu Xinan , Sun Jian , Wang Mo , Baker Kirstie , Marion Kenneth M. , Huang Xiwen , Baghdasaryan Elmira , Ambati Meenakshi , Ambati Vidya L. , Pandey Akshat , Pandya Lekha , Cummings Tammy , Banerjee Daipayan , Huang Peirong , Yerramothu Praveen , Tolstonog Genrich V. , Held Ulrike , Erwin Jennifer A. , Paquola Apua C. M. , Herdy Joseph R. , Ogura Yuichiro , Terasaki Hiroko , Oshika Tetsuro , Darwish Shaban , Singh Ramendra K. , Mozaffari Saghar , Bhattarai Deepak , Kim Kyung Bo , Hardin James W. , Bennett Charles L. , Hinton David R. , Hanson Timothy E. , Röver Christian , Parang Keykavous , Kerur Nagaraj , Liu Jinze , Werner Brian C. , Sutton S. Scott , Sadda Srinivas R. , Schumann Gerald G. , Gelfand Bradley D. , Gage Fred H. , Ambati Jayakrishna
Published: February 2021

Significance

Alu
elements, comprising more than 10% of the human genome, propagate via retrotransposition. This genomic expansion requires enzymatic activity of L1 that reverse transcribes
Alu
RNA into
Alu
cDNA in the nucleus. We report
Alu
also undergoes L1-mediated reverse transcription via self-priming in the cytoplasm independent of retrotransposition, providing evidence of human DNA synthesis in this cellular compartment. This newly discovered shunt molecule in the
Alu
replication cycle also induces death of the retinal pigmented epithelium, a hallmark of atrophic age-related macular degeneration. A Big Data Archeology analysis of multiple health insurance databases reveals that use of FDA-approved nucleoside reverse transcriptase inhibitors is associated with protection against macular degeneration, identifying a repurposing candidate for this blinding disease.
Tribological properties of Al2O3/WS2 oil-based composite lubricant utilized on steel-brass frictional couples
Authors: Sujan Kafle , Wang Bingxu , Hu Ming , Meng Shaohua , Zhang Lijian , Hu Ruiqin , Barber Gary C
Published: February 2021

The tribological properties of Al2O3/WS2 composite lubricant were examined by using a ball-on-plate reciprocating sliding wear test configuration utilizing PAO6 base fluid and oleic acid as surfactant. The morphology and chemical composition of the wear tracks were examined by using a scanning electron microscope and a x-ray energy dispersive spectrometer. It was found that the coefficient of friction was reduced by 46.6% after adding 0.5 wt% Al2O3/WS2 composite particles. The wear width and wear depth were reduced by 37% and 59.6% after adding 3 wt% Al2O3/WS2 composite particles. In orthogonal tests, it was proposed that the best tribological performance of Al2O3/WS2 composite lubricant could be achieved while using the normal load of 50 N, frequency of 2 Hz and temperature of 65 °C. Frequency could be considered as the primary factor affecting the tribological properties of compsite lubricant. The excellent lubricating performance could be attributed to the formation of WS2 tribo-film with low shearing resistance, and a portion of the Al2O3 particles were embedded by external force to prevent surface contact between the steel ball and brass plate.
Synergic fabrication of titanium dioxide incorporation into heparin-polyvinyl alcohol nanocomposite: enhanced in vitro antibacterial activity and care of in vivo burn injury
Authors: Li Shougen , Zeng Jia , Yin Dongfang , Liao Peiqiang , Ding Siqing , Mao Ping , Liu Ying
Published: February 2021

In this study, a highly porous heparin-polyvinylalcohol@TiO2 nanocomposite (H-PVA@TiO2) bandage was fabricated by incorporating TiO2 into H-PVA hydrogel for burn injury. The effects of the H-PVA hydrogel and TiO2 nanoparticle composition on the functional group and surface properties of the as-prepared bandages were characterized by Fourier transform infrared spectroscopy (FT-IR) and x-ray diffractometry (XRD). The morphology of the H-PVA hydrogel and H-PVA@TiO2 were evaluated using a scanning electron microscope (SEM) and transmission electron microscope (TEM). A study of the material properties of H-PVA hydrogel has shown that the presence of TiO2 nanoparticles improves its toughness. Prepared H-PVA@TiO2 nanoporous dressing has indicated good antimicrobial activity against types of bacteria (Staphylococcus aureus and Escherichia coli) and excellent biocompatibility with human dermal fibroblast cells (HFFF2) suitable for biological applications. Additionally, in vivo experiments using Kunming mice showed it as-prepared H-PVA@TiO2 nanocomposite dressings improved wound healing and triggered skin cell development alongside collagen growth. Synergistic effects of the H-PVA@TiO2 nanocomposite hydrogel dressing material through in vivo experiments, such as its excellent hydrophilic design, strong bactericidal activity, biocompatibility and wound healing ability, make it a promising candidate for the treatment of burn injuries.
Microstructure and mechanical properties of Mg-2Zn-0.3Ca-0.5La magnesium alloy extruded with different temperatures
Authors: Hong Shu , Yungui Chen , Jianxun Wu , Maochao Zhang , Tang Yongbai
Published: February 2021

The extrusion tests of the Mg-2Zn-0.3Ca-0.5La (ZXLa200) alloy were carried out at different extrusion temperatures (260 °C–320 °C), and the mechanical properties and microstructure were studied and analyzed by means of optical microscope, scanning electron microscope, x-ray diffraction, transmission electron microscope, and tensile testing. The research have demonstrated significant influence of Extrusion temperature towards grain size, recrystallization grains and texture. With the extrusion temperature increases, the recrystallization grain of the extruded ZXLa200 alloy increases, but the texture intensity decreases. During the extrusion process, a large amount of Ca2Mg6Zn3 (50–200 nm) precipitates are precipitated, which inhibited the growth of dynamic recrystallization grains and improved the yield strength of the alloys. The tensile yield strength and elongation of extruded ZXLa200 alloy were acquired to be 375 MPa, 5.9% at 260 °C and 310 MPa, 19.2% at 320 °C.
Genome Size Reduction and Transposon Activity Impact tRNA Gene Diversity While Ensuring Translational Stability in Birds
Authors: Ottenburghs Jente , Geng Keyi , Suh Alexander , Kutter Claudia
Published: February 2021

As a highly diverse vertebrate class, bird species have adapted to various ecological systems. How this phenotypic diversity can be explained genetically is intensively debated and is likely grounded in differences in the genome content. Larger and more complex genomes could allow for greater genetic regulation that results in more phenotypic variety. Surprisingly, avian genomes are much smaller compared to other vertebrates but contain as many protein-coding genes as other vertebrates. This supports the notion that the phenotypic diversity is largely determined by selection on non-coding gene sequences. Transfer RNAs (tRNAs) represent a group of non-coding genes. However, the characteristics of tRNA genes across bird genomes have remained largely unexplored. Here, we exhaustively investigated the evolution and functional consequences of these crucial translational regulators within bird species and across vertebrates. Our dense sampling of 55 avian genomes representing each bird order revealed an average of 169 tRNA genes with at least 31% being actively used. Unlike other vertebrates, avian tRNA genes are reduced in number and complexity but are still in line with vertebrate wobble pairing strategies and mutation-driven codon usage. Our detailed phylogenetic analyses further uncovered that new tRNA genes can emerge through multiplication by transposable elements. Together, this study provides the first comprehensive avian and cross-vertebrate tRNA gene analyses and demonstrates that tRNA gene evolution is flexible albeit constrained within functional boundaries of general mechanisms in protein translation.
The Crashing Neonate
Authors: Kennedy Thomas M. , Sharieff Ghazala Q.
Published: February 2021

An increasing incidence of newborn emergency department visits in the United States has been documented; this may be due to a higher number of home births and hospital policies directing earlier discharge of newborns from nurseries. Although many of these visits are for benign conditions, it is imperative that the emergency physician know how to manage a critically ill neonate (a newborn in the first 28 days of life). The mnemonic, THE MISFITS, provides a method for remembering many of the serious conditions that present acutely in the neonatal period: trauma (accidental trauma and child abuse), heart disease (structural and nonstructural) and hypovolemia, endocrinopathies, metabolic abnormalities (electrolyte imbalances), inborn errors of metabolism, sepsis, formula mishaps (under- or overdilution), intestinal catastrophes (e.g., necrotizing enterocolitis and midgut volvulus), toxic exposures, and seizures. This chapter provides the essential clinical information for several of these conditions.
Vaccine-Preventable Disease
Authors: Yamamoto Loren G.
Published: February 2021

This chapter discusses disease entities that are vaccine preventable. Diseases not likely to be seen by physicians because of near eradication include diphtheria, tetanus, polio, and rabies. However, suspected rabies exposure is common, and initiating post-exposure prophylaxis is essential to preventing rabies. Clearly, other diseases that vaccines have reduced but not eliminated, such as pertussis, hepatitis A, hepatitis B, rotavirus, varicella/zoster, pneumococcal disease, meningococcal disease, influenza, respiratory syncytial virus, and tuberculosis, will be encountered. Haemophilus influenzae type b disease may also rarely be seen. There is great potential for physicians to never see a case of measles, mumps, and rubella, but because clusters of parents have chosen to not vaccinate their children, sporadic outbreaks will continue to occur.
The Pediatric Chest X-Ray
Authors: Yamamoto Loren G.
Published: February 2021

The pediatric chest X-ray (CXR) provides a wealth of useful information. In most instances, clinicians are seeking more definitive information regarding the lungs. Findings can be subtle or obvious, but difficult to notice. “Tunnel vision” permits the human brain to focus on areas of interest, only to miss other important findings. This chapter discusses the clinical entities that can be identified on a pediatric CXR and presents examples of most of these entities. The CXR is best read in a methodical manner focusing one’s attention on the heart, lungs, aorta, mediastinum, bones, neck, abdomen, and the periphery of the CXR.
Pediatric Cardiovascular Emergencies
Authors: Rose Jerri A.
Published: February 2021

Cardiovascular emergencies are relatively uncommon in children. Cardiovascular disease in infants and children may arise from structural heart lesions, conduction abnormalities, and acquired illnesses. Although causes and clinical presentations may vary widely, the common denominator for all pediatric cardiovascular emergencies is compromised cardiac output. Heart disease should be considered when evaluating children with common, nonspecific symptoms, including lethargy, poor feeding, respiratory distress, and abdominal pain. Rapid recognition, stabilization, and restoration of cardiac output in children with cardiovascular emergencies are paramount. Whereas cardiovascular emergencies are rare in children, chest pain and syncope are both common complaints in the pediatric population. Most children presenting with these complaints do not have underlying cardiac disease. Careful history and physical examination are essential in differentiating children with true cardiac disease from the majority with noncardiac etiologies.
Fluid and Electrolyte Emergencies
Authors: Mody Ameer P.
Published: February 2021

Fluid and electrolyte emergencies are a common presenting complaint in the emergency department. Dehydration emergencies can occur as a complicating factor of another illness or due to vomiting and/or diarrhea. The recognition and management of dehydration in infants and children are of critical importance to the emergency department provider. The severity of dehydration requires a focused history and detailed examination, with multiple elements required to determine the degree of illness. Oral rehydration is the preferred method of treatment for mild and moderate dehydration. Intravenous hydration is preferred for severe dehydration and moderate dehydration that has failed traditional oral rehydration therapy. Electrolyte derangements should be considered in patients with moderate and severe illness or for whom the clinical picture is unclear.
Pediatric Burns
Authors: Moehrle Neal , Osterman Jessica Lange
Published: February 2021

Burns can be classified into several categories, including thermal, electrical, and chemical injuries, each with its own unique clinical implications. Thermal injuries account for more than 120,000 pediatric emergency department visits every year and are the fourth leading cause of death among children in the United States. Among all burn-related injuries in adults and pediatrics, approximately two-thirds are related to scald injuries, 43% of which occur in children younger than 5 years of age. Emergency providers must be equipped to manage patients with burns of all severities, from those with impending respiratory collapse to those requiring only local wound care. This chapter discusses the classification of thermal burns, estimation of body surface area involved, initial emergency department management, and electrical burns.
Wound Care
Authors: Iyer Shweta R. , Tay Ee Tein
Published: February 2021

Wound care is a common complaint in the pediatric emergency department, and depending on the type of wound, there are a myriad of options for treatment. Various options exist for analgesia and anxiolysis, including child-friendly techniques and topical, oral, intranasal, and injectable medications. Options for wound repair include nonsuture techniques, which may be favorable in children when appropriate (e.g., hair apposition technique and tissue adhesives). This chapter discusses types of wounds, analgesia, cleaning, repair of wounds (including topical adhesives, sutures, and staples), and tetanus prophylaxis. Suturing methods and various types of sutures with their respective indications are reviewed. It also discusses common complications and indications for antibiotic treatment, imaging, consultations, and disposition.
Rheumatology
Authors: Maloney Meghan , Lim C. Anthoney
Published: February 2021

Rheumatic disease in children can involve multiple organ systems and requires care from various subspecialists. The presentation of rheumatic disease in children is often prolonged with insidious symptoms that can lead to delay in diagnosis. This chapter reviews the evaluation and management of the pediatric rheumatological conditions. The focus is on four specific diagnoses that illustrate the variety of disease presentations in this population: juvenile idiopathic arthritis; systemic lupus erythematosus; granulomatosis with polyangiitis, formerly known as Wegener’s granulomatosis; and juvenile dermatomyositis. For each diagnosis, the presentation, diagnostic workup, and emergency department management are discussed. Complications of each disorder are also reviewed in detail because they present a significant source of morbidity and mortality in this population and may be the reason for seeking medical care.
Pediatric Head Injury
Authors: Homme James L.
Published: February 2021

Blunt head trauma (BHT) is the leading cause of trauma-related death and disability in children worldwide. Pediatric BHT is a common presenting complaint in acute care settings. Traumatic brain injury (TBI) manifests as a continuum from minor to severe, with cases of minor TBI vastly outnumbering severe cases. Clinicians must be able to identify patients at low risk for TBI who do not require additional observation or testing while at the same time not missing higher risk patients. This chapter presents an evidence-based approach to the evaluation and management of BHT in pediatric patients across all ages and spectrums of severity.
Pediatric Thoraco-Abdominal Trauma
Authors: Amato Christopher S.
Published: February 2021

In children, injury is the most common cause of death. Thoracic and abdominal trauma are both associated with high morbidity and mortality, and they warrant a thorough evaluation. Abdominal trauma occurs in 25% of children with major trauma and is responsible for 9% of all trauma deaths. Because it can delay care, lack of recognition of intra-abdominal injury increases morbidity and mortality. Thoracic trauma comprises only 4–6% of pediatric trauma but is related to 14% of pediatric trauma-related deaths and is the second most common cause of mortality in pediatric trauma. This chapter discusses the keys to the evaluation of the pediatric trauma patient with thoraco-abdominal injury, including the evidence-based approach and algorithms to be utilized by medical personnel.
Pediatric Orthopedic Emergencies
Authors: Semple-Hess Janet
Published: February 2021

Children’s bones, due to their continual maturity during childhood and into late adolescence and their unique features such as growth plates, can present a challenge to the emergency physician. Interpretation of radiographs when looking for fractures in growing children, as well as deciding on treatment and determining whether to employ surgical versus nonsurgical management, requires knowledge of the patterns of injury in children. This chapter discusses these injuries as well as fractures related to child abuse, overuse injuries, back pain in children, radial head subluxation, slipped capital femoral epiphyses, avulsion fractures of the pelvis, Perthes disease, and infectious diseases (osteomyelitis and septic arthritis).
Pediatric Gastrointestinal Emergencies
Authors: Easter Joshua
Published: February 2021

Many conditions affect the gastrointestinal tract in children. Compared with adult gastrointestinal problems, gastrointestinal problems in children present with unique signs and symptoms. In younger children, it can be particularly difficult to elicit reliable diagnostic information from the history and physical examination. Pediatric gastrointestinal disease often requires surgical intervention, and delays in diagnosis may lead to significant morbidity and mortality. The differential diagnosis depends on age. Presentation also varies with age, and many conditions are unique to children. This chapter discusses important gastrointestinal emergencies. The classic pediatric presentation, atypical presentation, diagnostic features, treatment, and potential complications for these emergencies are also detailed.
Obstetrical Emergencies
Authors: McFarlin Anna
Published: February 2021

Pregnancy should be considered in all adolescent females presenting to the emergency department. Roughly half of all teenagers report that they are sexually active. Pregnancy in teenagers has many unique risk factors and potential complications. Due to concerns about confidentiality, transportation, cost, embarrassment, and perception of judgment, teens are less likely to seek care for possible pregnancy. When they do seek care, they are more likely to present to the emergency department than to a primary care provider. They often present at a much more advanced gestational age compared to their adult counterparts. This chapter reviews several important complications in the diagnosis and management of pregnancy, associated complications, and details important management principles in the care of the pregnant teenager.
Pediatric Foreign Bodies
Authors: Dietrich Ann M.
Published: February 2021

Foreign bodies are common in children. Ear, nose, gastrointestinal , vaginal, and rectal foreign bodies are all possible and may pose a challenge to the clinician. Children with attention-deficit/hyperactivity disorder, autism, or mental health issues are more likely to insert a foreign body into an orifice. Both organic and non-organic objects may be inserted. Most objects do not cause problems, but objects such as magnets, batteries, and long, sharp objects may result in significant adverse events. If one object is present, there may also be other objects in other locations, so a comprehensive evaluation must be conducted. This chapter reviews the clinical presentation, diagnostic options, and therapeutic choices for management.
Child Abuse
Authors: Main Rhiannon , Jacobson Laura , Young Amy , Young Tim
Published: February 2021

Child maltreatment is an important clinical condition. The emergency department (ED) is frequently the site of initial evaluation when a child is the victim of an acute inflicted injury. Abused children may present to the ED for vague complaints that could be attributed to a more benign illness such as a viral infection, but have evidence of abusive injuries. This evidence is sometimes overt but often subtle. Recognition of these injuries may save the child’s life, spare them from years of psychological and physical suffering, and prevent long-term morbidity such as intellectual disability and need for chronic medical care. In this way, emergency providers are at the front line of child abuse detection. This chapter details important diagnostic tools for evaluation of potential child maltreatment.
Medical Legal Aspects
Authors: Joseph Madeline
Published: February 2021

Children and adolescents may present to the emergency department (ED) without a guardian for several reasons, such as emergencies occurring during school or lack of guardian availability so that relatives, family friends, or day care or school personnel must accompany children to the ED. Concern about providing evaluation and treatment without formal consent is one of the challenges that emergency physicians face when minor patients present to the ED without parents or guardians. The Emergency Medical Treatment and Labor Act mandates that all patients, including minors, presenting to the ED receive a medical screening examination to determine if an emergency medical condition exists. This chapter reviews who can provide consent for minors; cases in which minors can be treated without consent in the ED, including minors involved in the juvenile justice system; and adolescent emancipation.
Psychosocial and mental health impacts of migration on ‘left-behind’ children of international migrant workers
Authors: Vanore Michaella , Wickramage Kolitha Prabhash , Devakumar Delanjathan , Jordan Lucy P.
Published: February 2021

Global migration flows include large numbers of labour migrants, many of whom are of prime child-bearing/rearing age and have children who must remain in the origin country during the migration episode. The psychosocial and mental health (PSMH) needs of children and other family members who are separated from migrant kin can be extremely complex and have been largely neglected in research and in intervention frameworks. This chapter explores the PSMH of children who remain in the origin country following parental migration and identifies the interrelated factors at individual, household, and societal levels that shape the influence of migration on child PSMH. A review of empirical evidence from different world regions informs a conceptual framework that identifies pathways of influence between migration and child PSMH. The framework emphasizes that the impact of migration on child outcomes is diverse and shaped by factors and characteristics at micro- (e.g. child sex, child age), meso- (e.g. household composition, community support structures), and macro-levels (e.g. migration policy, domestic laws for child protection). The consequences of parental migration for a child’s PSMH vulnerability or thriving trajectory are far from universal and require a context-specific and nuanced response from healthcare practitioners, clinicians, and policymakers.
Systematic identification of non-coding somatic single nucleotide variants associated with altered transcription and DNA methylation in adult and pediatric cancers
Authors: Chen Fengju , Zhang Yiqun , Creighton Chad J
Published: February 2021

Whole-genome sequencing combined with transcriptomics can reveal impactful non-coding single nucleotide variants (SNVs) in cancer. Here, we developed an integrative analytical approach that, as a first step, identifies genes altered in expression or DNA methylation in association with nearby somatic SNVs, in contrast to alternative approaches that first identify mutational hotspots. Using genomic datasets from the Pan-Cancer Analysis of Whole Genomes (PCAWG) consortium and the Children's Brain Tumor Tissue Consortium (CBTTC), we identified hundreds of genes and associated CpG islands for which the nearby presence of a non-coding somatic SNV recurrently associated with altered expression or DNA methylation, respectively. Genomic regions upstream or downstream of genes, gene introns and gene untranslated regions were all involved. The PCAWG adult cancer cohort yielded different significant SNV-expression associations from the CBTTC pediatric brain tumor cohort. The SNV-expression associations involved a wide range of cancer types and histologies, as well as potential gain or loss of transcription factor binding sites. Notable genes with SNV-associated increased expression include TERT, COPS3, POLE2 and HDAC2—involving multiple cancer types—MYC, BCL2, PIM1 and IGLL5—involving lymphomas—and CYHR1—involving pediatric low-grade gliomas. Non-coding somatic SNVs show a major role in shaping the cancer transcriptome, not limited to mutational hotspots.