bluuebunny/crossref_metadata_2025 huggingface dataset:
CATALYTIC SYNTHESIS OF GLYCOLIC ACID AND ITS METHYL ESTER FROM GLYOXAL
Authors: Levytska Svitlana , Mylin Artur
Published: January 2021

Glycolic acid is practically non-toxic to humans, has bactericidal properties and a weak odor, which makes it widely used in food (as a flavoring and preservative) textile (as a dye and tanning agent), cosmetics and pharmaceuticals (as a keratolytic and a skin care agen). Glycolic acid can also be converted to biodegradable polymer with good mechanical properties and excellent biocompatibility, wich is used for different medical applications. In industry, glycolic acid is obtained by carbonylation of formaldehyde using as catalysts quite aggressive acids (H2SO4, HCl, HF), hydrolysis of hydroxyacetonitrile under the influence of acids (H2SO3, H3PO3) or the enzyme nitrilase and saponification of chloroacetic acid with a double excess of alkali (NaOH, KOH). In addition to the non-ecological nature of used raw materials for this process there is a problem associated of purification of the product especially from homogeneous catalysts. The process of obtaining glycolic acid and its methyl ester from glyoxal over a number of solid acid and basic catalysts based on mixed oxides of aluminum, tin, titanium, zirconium, and magnesium has been studied. In study, commercially available 40% aqueous solution of glyoxal, anhydrous glyoxal trimer (Sigma-Aldrich, 95%) and methanol (99%, Merck) were used. Catalytic experiments were carried out in rotated steel autoclave (60 rpm) for 0.5–5 hours at temperatures of 100–170 °C. It is shown that the synthesized oxide catalysts after 5 h of reaction at 100 °C provide up to 98% conversion of an aqueous solution of glyoxal to glycolic acid with a selectivity of 83–100%.It was found that over the studied basic catalysts the undesirable oligomerization process of the formed glycolic acid occurred to a lesser extent and as a result the yield of monoglycolic acid was much higher (60–69%) than over acid catalysts (28–40%). The most selective MgO-ZrO2 catalyst after 1 h of the reaction at 150 °C of methanolicglyoxal solution provides almost 100% yield of methyl glycolate.
Behavior of Dynamic Strain Aging in Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr Alloy Strip
Authors: Kim Il-Hyun , Lee Myung-Ho , Jung Yang-Il , Kim Hyun-Gil , Jang Jae-Il
Published: January 2021

The behavior of dynamic strain aging (DSA) in a Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr alloy strip was investigated at temperature ranges of 25–600 °C via a tensile test. The tensile test was performed at two different strain rates 8.33 × 10-5 and 1.67 × 10-2 s-1. The shear stress of the alloy strip revealed a linear dependency on the test temperature when the specimens were tested under a higher strain rate (1.67 × 10-2 s-1). However, the linear relationship was broken due to DSA when the samples were deformed under a lower strain rate (8.33 × 10-5 s-1). The discrepancy was most significant at 400 °C. The trend in DSA behavior was similar irrespective of the orientation of the samples, i.e., rolling direction (RD) or transverse direction (TD). However, the effect of DSA was larger in the TD samples than the RD samples. The phenomena were interpreted to the variation in work hardening exponents and strain rate sensitivity. The value of the exponent decreased from 0.14 to 0.08 along a RD and from 0.1 to 0.07 along a TD, respectively. However, the smallest value was observed at 400–500 °C irrespective of the specimen orientation, which is consistent with the DSA behavior. It is suggested that the DSA was caused by an interaction of moving dislocations with solute atoms typically oxygen.
NILAI-NILAI BUDAYA DALAM UPACARA NENI URAN WAIR PADA MASYARAKAT TANAH AI DI KABUPATEN SIKKA NUSATENGARA TIMUR
Authors: Nuwa Gustav Gisela , Aquinoranda Maria R.
Published: January 2021

Cultural issues are the ones often discussed today, especially in the effort to preserve them. In the Tanah Ai community, it is very important to maintain ancestral heritage in the Neni Uran Wair ceremony. This research was conducted in Sikka Regency, East Nusa Tenggara, Tanah Ai Tribe. This study aims to determine the values contained in the Neni Uran Wair ceremony and the effort to preserve cultural values ​​in the Neni Uran Wair ceremony. In this study, researchers used qualitative methods using ethnographic methods. The data sources in this research were primary data and secondary data. Primary data included customary leaders, community leaders and youth, while secondary data included documents and photos of documentation. The techniques of collecting data used in this study were observation, interviews, and documentation. Meanwhile, data analysis technique included data collection, data education, data presentation and data verification. The results showed that the values ​​contained in the Neni Uran Wair ceremony were religious, cooperation values, brotherhood values, social values, and economic values. Meanwhile, the conservation efforts includes the involvement of the local government and the young generation by forming a customary group and location (Nuba and Mahe), and cultural revitalization.
KONDISI SOSIAL EKONOMI NELAYAN PENANGKAP IKAN JULUNG-JULUNG DI WILAYAH PESISIR KAMPUNG PALARENG KABUPATEN KEPULAUAN SANGIHE
Authors: Sarapil Costantein Imanuel , Kumaseh Eunike Irene , Ikhtiagung Ganjar Ndaru , Lahungkasiang Putri , Puspaputri Erlin
Published: January 2021

Penelitian ini bertujuan untuk mengetahui kondisi sosial ekonomi nelayan serta menganalisis usaha penangkapan ikan julung-julung dengan soma giop di Kampung Palareng. Kegiatan usaha penangkapan ikan yang sudah berlangsung lama, sehingga menarik untuk diketahui apakah usaha tersebut memberi keuntungan bagi nelayan di Kampung Palareng. Metode yang digunakan dalam penelitian ini yaitu metode kualitatif dan kuantitatif. Dimana penelitian kualitatif menggunakan fenomena sosial menjadi pusat perhatian. Sedangkan penelitian kuantitatif menggunakan analisa dan perhitungan. Hasil penelitian disajikan secara deskriptif kualitatif, sementara untuk memperoleh  nilai B/C, NPV dan PP menggunakan metode kuantitatif. Kondisi sosial nelayan di Kampung Palareng masih sangat kuat. Solidaritas yang tinggi bagi masyarakat dapat terlihat dalam kegiatan gotong royong maupun kegiatan sosial lainnya. Sebagian besar masyarakat mempunyai tingkat pendidikan Sekolah Dasar (SD). Pendapatan yang tegolong tinggi bagi para nelayan. Secara finansial, analisis kelayakan usaha penangkapan ikan julung-julung diperoleh hasil BCR sebesar 0,96 dimana B/C kurang dari 1, PP 1 tahun, dan NPV sebesar Rp -12.472.049 (NPV bernilai negatif). Secara Finansial, usaha penangkapan ikan julung-julung di Kampung Palareng tidak layak untuk diteruskan. Namun, usaha penangkapan ikan julung-julung memiliki makna sosial dan budaya yang tinggi bagi kehidupan masyarakat Kampung Palareng. Baik perempuan maupun laki-laki, tua dan muda, semua bekerja sama ikut perahu penangkap ikan julung-julung dan mengikuti kegiatan pengoperasian penangkapan ikan. Hasil tangkapan dibagi untuk semua yang mengikuti kegiatan penangkapan maupun bagi masyarakat secara keseluruhan. Nilai sosial budaya ini yang mempertahankan keberadaan usaha penangkapan ikan julung-julung di Kampung Palareng.
The Home State Effect on National Business Coalitions: Evidence from U.S. Climate Politics
Authors: Meckling Jonas , Trachtman Samuel
Published: January 2021

Opposition from organized business interests can impede policy reform. Under what conditions are firms incentivized to support reform? We argue that in federal systems state policy and politics can have a home state effect on the national preferences of firms and firms’ coalition membership. State policies can force firms to absorb regulatory cost, thus reducing the marginal cost of national policies. In addition, firms heavily regulated at the state level have incentives to strategically align with their state governments. We test our argument by matching original data on the positions of large electric utilities towards the Clean Power Plan and data on ad hoc coalition membership with data measuring state policy stringency and state government positions. Quantitative evidence is consistent with hypotheses: both state policies and state politics influence utilities’ national positions. Elite interviews help clarify different mechanisms. Our findings show how sub-national governments shape national interest group politics.
Utveckling, lärande, forskning (ULF) – i samverkan mellan akademi och skola
Authors: Thorsten Anja
Published: January 2021

Verksamheten i skolan kommer alltid att stöta på utmaningar, hinder och problem där det krävs ny kunskap, utveckling och förändring. Det gör att det finns stora vinster med en nära samverkan mellan universitet och skola.
«МОИ ВОСПОМИНАНИЯ»: ВОСПОМИНАНИЯ ВАЛЕНТИНЫ АНДРЕЕВНЫ ЗВОНКОВОЙ. Ч. 2
Authors: Олег Викторович Кириченко
Published: January 2021

Аннотация. Воспоминания В. А. Звонковой посвящены церковной жизни автора, начиная с послевоенного времени и заканчивая 2000-ми годами. В центре воспоминаний стоит судьба самого автора, идущего сложной и тернистой дорогой православного христианина в атеистическом государстве и обществе. Автор показывает, что путь этот был непрост не только из-за преследований верующих, но даже в большей степени из-за особой нравственной атмосферы в быстро атеизирующемся советском обществе, где попирались традиционные нормы брачных отношений, где рушились привычные родственные связи и т. д. Воспоминания отмечены тонкими наблюдениями автора за жизнью современников, как церковной, так и светской.
Ключевые слова: православная вера, Русская Православная Церковь, благочестие, аскетика, духовничество, старчество, церковный приход, советская эпоха, воспоминания.

Abstract. The memoirs of V. A. Zvonkova are devoted to church life from the 1940-s to the 2000-s. At the heart of the memoirs is the fate of the author herself, walking the difficult path of the Orthodox Christian in an atheistic state and society. The author shows that this path was not easy, not only because of the persecution of believers, but even more so because of the special moral atmosphere in the rapidly atheizing Soviet society, where the traditional norms of marital relations were violated, where familiar family ties were broken, etc. The memoirs are marked by the author’s subtle observations of the life of contemporaries, both churchly and secular. Keywords: memoirs, Soviet era from the 1940-s to the beginning of the 2000-s, Orthodox Christian church, church, priests, parish life.
Key words: Orthodox faith, Russian Orthodox Church, piety, asceticism, clergy, eldership, church parish.
The Effect of Degeneration on Internal Strains and the Mechanism of Failure in Human Intervertebral Discs Analyzed Using Digital Volume Correlation (DVC) and Ultra-High Field MRI
Authors: Tavana Saman , Masouros Spyros D. , Baxan Nicoleta , Freedman Brett A. , Hansen Ulrich N. , Newell Nicolas
Published: January 2021

The intervertebral disc (IVD) plays a main role in absorbing and transmitting loads within the spinal column. Degeneration alters the structural integrity of the IVDs and causes pain, especially in the lumbar region. The objective of this study was to investigate non-invasively the effect of degeneration on human 3D lumbar IVD strains (n= 8) and the mechanism of spinal failure (n= 10) under pure axial compression using digital volume correlation (DVC) and 9.4 Tesla magnetic resonance imaging (MRI). Degenerate IVDs had higher (p< 0.05) axial strains (58% higher), maximum 3D compressive strains (43% higher), and maximum 3D shear strains (41% higher), in comparison to the non-degenerate IVDs, particularly in the lateral and posterior annulus. In both degenerate and non-degenerate IVDs, peak tensile and shear strains were observed close to the endplates. Inward bulging of the inner annulus was observed in all degenerate IVDs causing an increase in the AF compressive, tensile, and shear strains at the site of inward bulge, which may predispose it to circumferential tears (delamination). The endplate is the spine's “weak link” in pure axial compression, and the mechanism of human vertebral fracture is associated with disc degeneration. In non-degenerate IVDs the locations of failure were close to the endplate centroid, whereas in degenerate IVDs they were in peripheral regions. These findings advance the state of knowledge on mechanical changes during degeneration of the IVD, which help reduce the risk of injury, optimize treatments, and improve spinal implant designs. Additionally, these new data can be used to validate computational models.
Serine/threonine Kinases Play Important Roles in Regulating Polyunsaturated Fatty Acid Biosynthesis in Synechocystis sp. PCC6803
Authors: Chen Gao , Cao Yuelei , Zhong Huairong , Wang Xiaodong , Li Yanle , Cui Xiaoyan , Lu Xiaoyuan , Bi Xiangdong , Dai Meixue
Published: January 2021

Serine/threonine kinases (STKs) play important roles in prokaryotic cellular functions such as growth, differentiation, and secondary metabolism. When the external environment changes, prokaryotes rely on signal transduction systems, including STKs that quickly sense these changes and alter gene expression to induce the appropriate metabolic changes. In this study, we examined the roles of the STK genes spkD and spkG in fatty acid biosynthesis in the unicellular cyanobacterium Synechocystis sp. PCC6803, using targeted gene knockout. The linoleic acid (C18: 2), γ-linolenic acid (C18: 3n6), α-linolenic acid (C18: 3n3), and stearidonic acid (C18: 4) levels were significantly lower in spkD and spkG gene knockout mutants than in the wild type at a culture temperature of 30°C and a light intensity of 40 μmol⋅m–2⋅s–1. The expression levels of fatty acid desaturases and STK genes differed between the spkD and spkG gene knockout mutants. These observations suggest that spkD and spkG may directly or indirectly affect the fatty acid composition in Synechocystis sp. PCC6803 by regulating the expression of fatty acid desaturases genes. Therefore, the STK genes spkD and spkG play important roles in polyunsaturated fatty acid biosynthesis in Synechocystis sp. PCC6803. These findings could facilitate the development of cyanobacteria germplasm resources that yield high levels of fatty acids. In addition, they provide a theoretical basis for the genetic engineering of cyanobacteria with improved yields of secondary metabolites and increased economic benefits.
Modulation of Increased mGluR1 Signaling by RGS8 Protects Purkinje Cells From Dendritic Reduction and Could Be a Common Mechanism in Diverse Forms of Spinocerebellar Ataxia
Authors: Wu Qin-Wei , Kapfhammer Josef P.
Published: January 2021

Spinocerebellar ataxias (SCAs) are a group of hereditary neurodegenerative diseases which are caused by diverse genetic mutations in a variety of different genes. We have identified RGS8, a regulator of G-protein signaling, as one of the genes which are dysregulated in different mouse models of SCA (e.g., SCA1, SCA2, SCA7, and SCA14). In the moment, little is known about the role of RGS8 for pathogenesis of spinocerebellar ataxia. We have studied the expression of RGS8 in the cerebellum in more detail and show that it is specifically expressed in mouse cerebellar Purkinje cells. In a mouse model of SCA14 with increased PKCγ activity, RGS8 expression was also increased. RGS8 overexpression could partially counteract the negative effects of DHPG-induced mGluR1 signaling for the expansion of Purkinje cell dendrites. Our results suggest that the increased expression of RGS8 is an important mediator of mGluR1 pathway dysregulation in Purkinje cells. These findings provide new insights in the role of RGS8 and mGluR1 signaling in Purkinje cells and for the pathology of SCAs.
MiRNA Regulatory Functions in Photoreceptors
Authors: Pawlick Julia Sophie , Zuzic Marta , Pasquini Giovanni , Swiersy Anka , Busskamp Volker
Published: January 2021

MicroRNAs (miRNAs) are important regulators of gene expression. These small, non-coding RNAs post-transcriptionally silence messenger RNAs (mRNAs) in a sequence-specific manner. In this way, miRNAs control important regulatory functions, also in the retina. If dysregulated, these molecules are involved in several retinal pathologies. For example, several miRNAs have been linked to essential photoreceptor functions, including light sensitivity, synaptic transmission, and modulation of inflammatory responses. Mechanistic miRNA knockout and knockdown studies further linked their functions to degenerative retinal diseases. Of note, the type and timing of genetic manipulation before, during, or after retinal development, is important when studying specific miRNA knockout effects. Within this review, we focus on miR-124 and the miR-183/96/182 cluster, which have assigned functions in photoreceptors in health and disease. As a single miRNA can regulate hundreds of mRNAs, we will also discuss the experimental validation and manipulation approaches to study complex miRNA/mRNA regulatory networks. Revealing these networks is essential to understand retinal pathologies and to harness miRNAs as precise therapeutic and diagnostic tools to stabilize the photoreceptors’ transcriptomes and, thereby, function.
Assessing Autophagy in Muscle Stem Cells
Authors: Campanario Silvia , Ramírez-Pardo Ignacio , Hong Xiaotong , Isern Joan , Muñoz-Cánoves Pura
Published: January 2021

The skeletal muscle tissue in the adult is relatively stable under normal conditions but retains a striking ability to regenerate by its resident stem cells (satellite cells). Satellite cells exist in a quiescent (G0) state; however, in response to an injury, they reenter the cell cycle and start proliferating to provide sufficient progeny to form new myofibers or undergo self-renewal and returning to quiescence. Maintenance of satellite cell quiescence and entry of satellite cells into the activation state requires autophagy, a fundamental degradative and recycling process that preserves cellular proteostasis. With aging, satellite cell regenerative capacity declines, correlating with loss of autophagy. Enhancing autophagy in aged satellite cells restores their regenerative functions, underscoring this proteostatic activity’s relevance for tissue regeneration. Here we describe two strategies for assessing autophagic activity in satellite cells from GFP-LC3 reporter mice, which allows direct autophagosome labeling, or from non-transgenic (wild-type) mice, where autophagosomes can be immunostained. Treatment of GFP-LC3 or WT satellite cells with compounds that interfere with autophagosome-lysosome fusion enables measurement of autophagic activity by flow cytometry and immunofluorescence. Thus, the methods presented permit a relatively rapid assessment of autophagy in stem cells from skeletal muscle in homeostasis and in different pathological scenarios such as regeneration, aging or disease.
Mechanotranduction Pathways in the Regulation of Mitochondrial Homeostasis in Cardiomyocytes
Authors: Liao Hongyu , Qi Yan , Ye Yida , Yue Peng , Zhang Donghui , Li Yifei
Published: January 2021

Mitochondria are one of the most important organelles in cardiomyocytes. Mitochondrial homeostasis is necessary for the maintenance of normal heart function. Mitochondria perform four major biological processes in cardiomyocytes: mitochondrial dynamics, metabolic regulation, Ca2+ handling, and redox generation. Additionally, the cardiovascular system is quite sensitive in responding to changes in mechanical stress from internal and external environments. Several mechanotransduction pathways are involved in regulating the physiological and pathophysiological status of cardiomyocytes. Typically, the extracellular matrix generates a stress-loading gradient, which can be sensed by sensors located in cellular membranes, including biophysical and biochemical sensors. In subsequent stages, stress stimulation would regulate the transcription of mitochondrial related genes through intracellular transduction pathways. Emerging evidence reveals that mechanotransduction pathways have greatly impacted the regulation of mitochondrial homeostasis. Excessive mechanical stress loading contributes to impairing mitochondrial function, leading to cardiac disorder. Therefore, the concept of restoring mitochondrial function by shutting down the excessive mechanotransduction pathways is a promising therapeutic strategy for cardiovascular diseases. Recently, viral and non-viral protocols have shown potentials in application of gene therapy. This review examines the biological process of mechanotransduction pathways in regulating mitochondrial function in response to mechanical stress during the development of cardiomyopathy and heart failure. We also summarize gene therapy delivery protocols to explore treatments based on mechanical stress–induced mitochondrial dysfunction, to provide new integrative insights into cardiovascular diseases.
Shear Stress Rescued the Neuronal Impairment Induced by Global Cerebral Ischemia Reperfusion via Activating PECAM-1-eNOS-NO Pathway
Authors: Gao Jing-Quan , Wang Peng , Yan Jun-Wei , Ba Li-Na , Shi Pi-Long , Wu Hong-Mei , Guan Xue-Ying , Cao Yong-gang , Sun Hong-Li , Mao Xiao-Yuan
Published: January 2021

Microvessel hypoperfusion following ischemic stress resulted in a decreased shear stress of brain microvascular endothelial cells (BMECs) and contributed to abnormal expression of PECAM-1 after global cerebral ischemia/reperfusion (I/R) injury. Here, we identified novel pathophysiologic and rehabilitative procedures specific to shear stress in microvascular endothelial cells in response to global cerebral I/R injury. We found that the decrease in cerebral blood flow of gerbils after global cerebral I/R injury reduces shear stress, and the abnormal change in shear stress leads to microvascular endothelial cell and neuron damage. Nevertheless, suitable high levels of shear stress contribute to rescuing the dysfunction and malformation of BMECs via regulating the PECAM-1-eNOS-NO pathway to enhance nitric oxide release, decrease the expression of caspase-3 to reduce apoptosis, and improve the shear-adaptability of endothelial cells, thereby playing a protective role in the gerbil brain.
Identification of Methicillin-Resistant Staphylococcus Aureus From Methicillin-Sensitive Staphylococcus Aureus and Molecular Characterization in Quanzhou, China
Authors: Bai Zhimin , Chen Min , Lin Qiaofa , Ye Ying , Fan Hongmei , Wen Kaizhen , Zeng Jianxing , Huang Donghong , Mo Wenfei , Lei Ying , Liao Zhijun
Published: January 2021

To distinguish Methicillin-Resistant Staphylococcus aureus (MRSA) from Methicillin-Sensitive Staphylococcus aureus (MSSA) in the protein sequences level, test the susceptibility to antibiotic of all Staphylococcus aureus isolates from Quanzhou hospitals, define the virulence factor and molecular characteristics of the MRSA isolates. MRSA and MSSA Pfam protein sequences were used to extract feature vectors of 188D, n-gram and 400D. Weka software was applied to classify the two Staphylococcus aureus and performance effect was evaluated. Antibiotic susceptibility testing of the 81 Staphylococcus aureus was performed by the Mérieux Microbial Analysis Instrument. The 65 MRSA isolates were characterized by Panton-Valentine leukocidin (PVL), X polymorphic region of Protein A (spa), multilocus sequence typing test (MLST), staphylococcus chromosomal cassette mec (SCCmec) typing. After comparing the results of Weka six classifiers, the highest correctly classified rates were 91.94, 70.16, and 62.90% from 188D, n-gram and 400D, respectively. Antimicrobial susceptibility test of the 81 Staphylococcus aureus: Penicillin-resistant rate was 100%. No resistance to teicoplanin, linezolid, and vancomycin. The resistance rate of the MRSA isolates to clindamycin, erythromycin and tetracycline was higher than that of the MSSAs. Among the 65 MRSA isolates, the positive rate of PVL gene was 47.7% (31/65). Seventeen sequence types (STs) were identified among the 65 isolates, and ST59 was the most prevalent. SCCmec type III and IV were observed at 24.6 and 72.3%, respectively. Two isolates did not be typed. Twenty-one spa types were identified, spa t437 (34/65, 52.3%) was the most predominant type. MRSA major clone type of molecular typing was CC59-ST59-spa t437-IV (28/65, 43.1%). Overall, 188D feature vectors can be applied to successfully distinguish MRSA from MSSA. In Quanzhou, the detection rate of PVL virulence factor was high, suggesting a high pathogenic risk of MRSA infection. The cross-infection of CA-MRSA and HA-MRSA was presented, the molecular characteristics were increasingly blurred, HA-MRSA with typical CA-MRSA molecular characteristics has become an important cause of healthcare-related infections. CC59-ST59-spa t437-IV was the main clone type in Quanzhou, which was rare in other parts of mainland China.
3D Printed Biomimetic PCL Scaffold as Framework Interspersed With Collagen for Long Segment Tracheal Replacement
Authors: She Yunlang , Fan Ziwen , Wang Long , Li Yinze , Sun Weiyan , Tang Hai , Zhang Lei , Wu Liang , Zheng Hui , Chen Chang
Published: January 2021

The rapid development of tissue engineering technology has provided new methods for tracheal replacement. However, none of the previously developed biomimetic tracheas exhibit both the anatomy (separated-ring structure) and mechanical behavior (radial rigidity and longitudinal flexibility) mimicking those of native trachea, which greatly restricts their clinical application. Herein, we proposed a biomimetic scaffold with a separated-ring structure: a polycaprolactone (PCL) scaffold with a ring-hollow alternating structure was three-dimensionally printed as a framework, and collagen sponge was embedded in the hollows amid the PCL rings by pouring followed by lyophilization. The biomimetic scaffold exhibited bionic radial rigidity based on compressive tests and longitudinal flexibility based on three-point bending tests. Furthermore, the biomimetic scaffold was recolonized by chondrocytes and developed tracheal cartilage in vitro. In vivo experiments showed substantial deposition of tracheal cartilage and formation of a biomimetic trachea mimicking the native trachea both structurally and mechanically. Finally, a long-segment tracheal replacement experiment in a rabbit model showed that the engineered biomimetic trachea elicited a satisfactory repair outcome. These results highlight the advantage of a biomimetic trachea with a separated-ring structure that mimics the native trachea both structurally and mechanically and demonstrates its promise in repairing long-segment tracheal defects.
Mesenchymal Stromal Cells Promote Retinal Vascular Repair by Modulating Sema3E and IL-17A in a Model of Ischemic Retinopathy
Authors: Noueihed Baraa , Rivera José Carlos , Dabouz Rabah , Abram Pénélope , Omri Samy , Lahaie Isabelle , Chemtob Sylvain
Published: January 2021

Ischemic retinopathies (IRs), such as retinopathy of prematurity and diabetic retinopathy, are characterized by an initial phase of microvascular degeneration that results in retinal ischemia, followed by exaggerated pathologic neovascularization (NV). Mesenchymal stromal cells (MSCs) have potent pro-angiogenic and anti-inflammatory properties associated with tissue repair and regeneration, and in this regard exert protection to neurons in ischemic and degenerative conditions; however, the exact mechanisms underlying these functions remain largely unknown. Class III Semaphorins (A–G) are particularly implicated in regulating neural blood supply (as well as neurogenesis) by suppressing angiogenesis and affecting myeloid cell function; this is the case for distinct neuropillin-activating Sema3A as well as PlexinD1-activating Sema3E; but during IR the former Sema3A increases while Sema3E decreases. We investigated whether retinal vascular repair actions of MSCs are exerted by normalizing Semaphorin and downstream cytokines in IR. Intravitreal administration of MSCs or their secretome (MSCs-conditioned media [MSCs-CM]) significantly curtailed vasoobliteration as well as aberrant preretinal NV in a model of oxygen-induced retinopathy (OIR). The vascular repair effects of MSCs-CM in the ischemic retina were associated with restored levels of Sema3E. Vascular benefits of MSCs-CM were reversed by anti-Sema3E; while intravitreal injection of anti-angiogenic recombinant Sema3E (rSema3E) in OIR-subjected mice reproduced effects of MSCs-CM by inhibiting as expected preretinal NV but also by decreasing vasoobliteration. To explain these opposing vascular effects of Sema3E we found in OIR high retinal levels, respectively, of the pro- and anti-angiogenic IL-17A and Sema3A-regulating IL-1β; IL-17A positively affected expression of IL-1β. rSema3E decreased concentrations of these myeloid cell-derived pro-inflammatory cytokinesin vitroandin vivo. Importantly, IL-17A suppression by MSCs-CM was abrogated by anti-Sema3E neutralizing antibody. Collectively, our findings provide novel evidence by which MSCs inhibit aberrant NV and diminish vasoobliteration (promoting revascularization) in retinopathy by restoring (at least in part) neuronal Sema3E levels that reduce pathological levels of IL-17A (and in turn other proinflammatory factors) in myeloid cells. The ability of MSCs to generate a microenvironment permissive for vascular regeneration by controlling the production of neuronal factors involved in immunomodulatory activities is a promising opportunity for stem cell therapy in ocular degenerative diseases.
Discovery of Diaryl Ether Substituted Tetrahydrophthalazinones as TbrPDEB1 Inhibitors Following Structure-Based Virtual Screening
Authors: de Heuvel Erik , Kooistra Albert J. , Edink Ewald , van Klaveren Sjors , Stuijt Jeffrey , van der Meer Tiffany , Sadek Payman , Mabille Dorien , Caljon Guy , Maes Louis , Siderius Marco , de Esch Iwan J. P. , Sterk Geert Jan , Leurs Rob
Published: January 2021

Several members of the 3′,5′-cyclic nucleotide phosphodiesterase (PDE) family play an essential role in cellular processes, which has labeled them as interesting targets for various diseases. The parasitic protozoan Trypanosoma brucei, causative agent of human African trypanosomiasis, contains several cyclic AMP specific PDEs from which TbrPDEB1 is validated as a drug target. The recent discovery of selective TbrPDEB1 inhibitors has increased their potential for a novel treatment for this disease. Compounds characterized by a rigid biphenyl tetrahydrophthalazinone core structure were used as starting point for the exploration of novel TbrPDEB1 inhibitors. Using a virtual screening campaign and structure-guided design, diaryl ether substituted phthalazinones were identified as novel TbrPDEB1 inhibitors with IC50 values around 1 μM against T. brucei. This study provides important structure-activity relationship (SAR) information for the future design of effective parasite-specific PDE inhibitors.
Hemodynamic Relevance of Anomalous Coronary Arteries Originating From the Opposite Sinus of Valsalva-In Search of the Evidence
Authors: Bigler Marius Reto , Ashraf Afreed , Seiler Christian , Praz Fabien , Ueki Yasushi , Windecker Stephan , Kadner Alexander , Räber Lorenz , Gräni Christoph
Published: January 2021

Coronary artery anomalies (CAA) represent a heterogeneous group of congenital disorders of the arterial coronary circulation, defined by an anomalous origin of the coronary ostium and/or vessel course. Of particular interest are anomalous coronary arteries originating from the opposite sinus of Valsalva (ACAOS). The interarterial variants (with the anomalous vessel situated between the great arteries) are historically called “malignant,” based on an anticipated higher risk for myocardial ischemia and sudden cardiac death (SCD), especially affecting young patients during strenuous physical activity. However, the interarterial course itself may not be the predominant cause of ischemia, but rather represents a surrogate for other ischemia-associated anatomical high-risk features. As the exact pathophysiology of ACAOS is not well-understood, there is a lack of evidence-based guidelines addressing optimal diagnostic work-up, downstream testing, sports counseling, and therapeutic options in patients with ACAOS. Therefore, treating physicians are often left with uncertainty regarding the clinical management of affected patients. This review focuses on the pathophysiologic consequences of ACAOS on myocardial ischemia and discusses the concept of the interplay between fixed and dynamic coronary stenosis. Further, we discuss the advantages and limitations of the different diagnostic modalities and give an outlook by highlighting the gaps of knowledge in the assessment of such anomalies.
Integrative Identification of Hub Genes Associated With Immune Cells in Atrial Fibrillation Using Weighted Gene Correlation Network Analysis
Authors: Yan Tao , Zhu Shijie , Zhu Miao , Wang Chunsheng , Guo Changfa
Published: January 2021

Background: Atrial fibrillation (AF) is the most common tachyarrhythmia in the clinic, leading to high morbidity and mortality. Although many studies on AF have been conducted, the molecular mechanism of AF has not been fully elucidated. This study was designed to explore the molecular mechanism of AF using integrative bioinformatics analysis and provide new insights into the pathophysiology of AF.

Methods: The GSE115574 dataset was downloaded, and Cibersort was applied to estimate the relative expression of 22 kinds of immune cells. Differentially expressed genes (DEGs) were identified through the limma package in R language. Weighted gene correlation network analysis (WGCNA) was performed to cluster DEGs into different modules and explore relationships between modules and immune cell types. Functional enrichment analysis was performed on DEGs in the significant module, and hub genes were identified based on the protein-protein interaction (PPI) network. Hub genes were then verified using quantitative real-time polymerase chain reaction (qRT-PCR).

Results: A total of 2,350 DEGs were identified and clustered into eleven modules using WGCNA. The magenta module with 246 genes was identified as the key module associated with M1 macrophages with the highest correlation coefficient. Three hub genes (CTSS, CSF2RB, and NCF2) were identified. The results verified using three other datasets and qRT-PCR demonstrated that the expression levels of these three genes in patients with AF were significantly higher than those in patients with SR, which were consistent with the bioinformatic analysis.

Conclusion: Three novel genes identified using comprehensive bioinformatics analysis may play crucial roles in the pathophysiological mechanism in AF, which provide potential therapeutic targets and new insights into the treatment and early detection of AF.
Large-Scale High-Resolution Coastal Mangrove Forests Mapping Across West Africa With Machine Learning Ensemble and Satellite Big Data
Authors: Liu Xue , Fatoyinbo Temilola E. , Thomas Nathan M. , Guan Weihe Wendy , Zhan Yanni , Mondal Pinki , Lagomasino David , Simard Marc , Trettin Carl C. , Deo Rinki , Barenblitt Abigail
Published: January 2021

Coastal mangrove forests provide important ecosystem goods and services, including carbon sequestration, biodiversity conservation, and hazard mitigation. However, they are being destroyed at an alarming rate by human activities. To characterize mangrove forest changes, evaluate their impacts, and support relevant protection and restoration decision making, accurate and up-to-date mangrove extent mapping at large spatial scales is essential. Available large-scale mangrove extent data products use a single machine learning method commonly with 30 m Landsat imagery, and significant inconsistencies remain among these data products. With huge amounts of satellite data involved and the heterogeneity of land surface characteristics across large geographic areas, finding the most suitable method for large-scale high-resolution mangrove mapping is a challenge. The objective of this study is to evaluate the performance of a machine learning ensemble for mangrove forest mapping at 20 m spatial resolution across West Africa using Sentinel-2 (optical) and Sentinel-1 (radar) imagery. The machine learning ensemble integrates three commonly used machine learning methods in land cover and land use mapping, including Random Forest (RF), Gradient Boosting Machine (GBM), and Neural Network (NN). The cloud-based big geospatial data processing platform Google Earth Engine (GEE) was used for pre-processing Sentinel-2 and Sentinel-1 data. Extensive validation has demonstrated that the machine learning ensemble can generate mangrove extent maps at high accuracies for all study regions in West Africa (92%–99% Producer’s Accuracy, 98%–100% User’s Accuracy, 95%–99% Overall Accuracy). This is the first-time that mangrove extent has been mapped at a 20 m spatial resolution across West Africa. The machine learning ensemble has the potential to be applied to other regions of the world and is therefore capable of producing high-resolution mangrove extent maps at global scales periodically.
Results from the Ice Thickness Models Intercomparison eXperiment Phase 2 (ITMIX2)
Authors: Farinotti Daniel , Brinkerhoff Douglas J. , Fürst Johannes J. , Gantayat Prateek , Gillet-Chaulet Fabien , Huss Matthias , Leclercq Paul W. , Maurer Hansruedi , Morlighem Mathieu , Pandit Ankur , Rabatel Antoine , Ramsankaran RAAJ , Reerink Thomas J. , Robo Ellen , Rouges Emmanuel , Tamre Erik , van Pelt Ward J. J. , Werder Mauro A. , Azam Mohod Farooq , Li Huilin , Andreassen Liss M.
Published: January 2021

Knowing the ice thickness distribution of a glacier is of fundamental importance for a number of applications, ranging from the planning of glaciological fieldwork to the assessments of future sea-level change. Across spatial scales, however, this knowledge is limited by the paucity and discrete character of available thickness observations. To obtain a spatially coherent distribution of the glacier ice thickness, interpolation or numerical models have to be used. Whilst the first phase of the Ice Thickness Models Intercomparison eXperiment (ITMIX) focused on approaches that estimate such spatial information from characteristics of the glacier surface alone, ITMIX2 sought insights for the capability of the models to extract information from a limited number of thickness observations. The analyses were designed around 23 test cases comprising both real-world and synthetic glaciers, with each test case comprising a set of 16 different experiments mimicking possible scenarios of data availability. A total of 13 models participated in the experiments. The results show that the inter-model variability in the calculated local thickness is high, and that for unmeasured locations, deviations of 16% of the mean glacier thickness are typical (median estimate, three-quarters of the deviations within 37% of the mean glacier thickness). This notwithstanding, limited sets of ice thickness observations are shown to be effective in constraining the mean glacier thickness, demonstrating the value of even partial surveys. Whilst the results are only weakly affected by the spatial distribution of the observations, surveys that preferentially sample the lowest glacier elevations are found to cause a systematic underestimation of the thickness in several models. Conversely, a preferential sampling of the thickest glacier parts proves effective in reducing the deviations. The response to the availability of ice thickness observations is characteristic to each approach and varies across models. On average across models, the deviation between modeled and observed thickness increase by 8.5% of the mean ice thickness every time the distance to the closest observation increases by a factor of 10. No single best model emerges from the analyses, confirming the added value of using model ensembles.
Potential Dust Induced Changes on the Seasonal Variability of Temperature Extremes Over the Sahel: A Regional Climate Modeling Study
Authors: Diba Ibrahima , Basse Jules , Ndiaye Mamadou , Sabaly Hamady Ngansou , Diedhiou Arona , Camara Moctar
Published: January 2021

The aim of this study is to simulate the impact of mineral dust emissions from the Sahel–Saharan zone on temperature extremes over the Sahel. To achieve this goal, we performed two numerical simulations: one with the standard version of the regional climate model RegCM4 (no dust run) and another one with the same version of this model incorporating a dust module (dust run). The difference between both versions of the model allowed to isolate the impacts of mineral dust emissions on temperature extremes. The results show that the accumulation of mineral dust into the atmosphere leads to a decrease of the frequency of warm days, very warm days, and warm nights over the Sahel. This decrease is higher during the MAM (March-April-May) and JJA (June-July-August) periods especially in the northern and western parts of the Sahel. The impact of the mineral dust emissions is also manifested by a decrease of the frequency of tropical nights especially during MAM in the northern Sahel. When considering the warm spells, mineral particles tend to weaken them especially in MAM and JJA in the northern Sahel. To estimate the potential impacts of the mineral dust accumulation on heat stress, the heat index and the humidex are used. The analysis of the heat index shows that the dust impact is to reduce the health risks particularly in the northern Sahel during the MAM period, in the western Sahel during JJA, and in the southern and the northeastern parts of the Sahel during the SON (September-October-November) period. As for the humidex, it is characterized by a decrease especially in the northern Sahel for all seasons. This reduction of the occurrence of thermal extremes may have a positive effect on the energy demand for cooling and on global health. However, the accumulation of dust particles in the atmosphere may also increase the meningitis incidence and prevalence.
Near-Field Body-Wave Extraction From Ambient Seafloor Noise in the Nankai Subduction Zone
Authors: Tonegawa Takashi , Kimura Toshinori , Araki Eiichiro
Published: January 2021

Ambient noise correlation is capable of retrieving waves propagating between two receivers. Although waves retrieved using this technique are primarily surface waves, the retrieval of body waves, including direct, refracted, and reflected waves, has also been reported from land-based observations. The difficulty of body wave extraction may be caused by large amplitudes and little attenuation of surface waves excited by microseisms, indicating that body wave extraction using seafloor records is very challenging because microseisms are generated in ocean areas and large amplitudes of surface waves are presumably observed at the seafloor. In this study, we used a unique dataset acquired by dense arrays deployed in the Nankai subduction zone, including a permanent cabled-network of 49 stations, a borehole sensor, and 150 temporary stations, to attempt to extract near-field body waves from ambient seafloor noise observed by multivariate sensors of broadband and short-period seismometers, differential pressure gauges (DPGs), and hydrophones. Our results show thatPwaves are extracted only in the DPG-record correlations at a frequency of 0.2–0.5 Hz, which can be seen up to a separation distance of two stations of 17 km with an apparent velocity of 3.2 km/s. At 1–3 Hz,Pwaves are observed only in the vertical-record correlations up to a separation distance of 11 km with an apparent velocity of 2.0 km/s. These velocity differences reflect the vertical velocity gradient of the accretionary prism, because thePwaves at low frequencies propagate at relatively long distances and therefore the turning depth is greater. Moreover, the long-period and short-periodPwaves are observed at the slope and flat regions on the accretionary prism, respectively. To investigate the retrieved wavefield characteristics, we conducted a two-dimensional numerical simulation for wave propagations, where we located single sources at the sea surface above the flat and slope bathymetry regions. Based on our observations and simulations, we suggest that the retrieval of near-field body waves from ambient seafloor noises depends on the relative amplitudes ofPand other surface waves in the ambient noise wavefield, and those are controlled by the subseafloor velocity structure, seafloor topography, and water depth.
Plethora of Traumatic Lesions of Bilateral Knee Extensor Mechanism in Osteogenesis Imperfecta
Authors: Kloen Peter , Hamdy Reggie Charles , Bech Niels Hendrik
Published: January 2021

Introduction

Injuries to the quadriceps extensor mechanism are rare in patients with Osteogenesis Imperfecta (OI). To the best of our knowledge, non-union of the patella in OI, either as an isolated problem or in combination with an acute fracture, has not been previously reported.

Case report

We describe how we surgically approached both the fracture and the non-union simultaneously. The surgical technique and steps are described in detail. Post-operative course was uneventful and the outcome was favorable, with full return of function for the patient.

Conclusion

A review of various knee extensor mechanism injuries in OI is described as illustrated in a single patient. The unusual simultaneous surgical treatment of a non-union and an acute fracture in the same patella shows that despite the severely compromised bone in this rare bone disease the bone still has a capacity to heal with a functional outcome.
Evaluating the Effect of Oil-Displacing Agents Using Computer Graphics and Visualization Glass Plate Model Experiments
Authors: Sun Xiangyu , Ge Jijiang , Ren Shang , Zhao An
Published: January 2021

The results of visualization experiments primarily provide descriptions of local features or a general conclusion because, to obtain accurate numerical results, it is necessary to count each small point in the visual image and calculate the remaining oil based on the color. There is currently no method that can automatically and accurately calculate the recovery factor based on a visualized image. Computer graphics can be used to solve this problem, and Matlab software with its powerful image calculation functions was used to analyze and calculate images of visualization experiment processes. This article first summarizes the development and respective characteristics of the visual experiment evaluation of oil displacement agents. Then, the corresponding relationship between the actual oil displacement recovery parameters and the image parameters is introduced in detail, and a calculation formula for the visual image recovery factor is summarized. Finally, using the quantitative visual experimental results from different oil displacement agent injection methods as an example, we compared the different oil displacement processes and their recovery. The different characteristics of the two injection methods were evaluated, and the feasibility of the calculation method was verified. This method provides data support for interpreting visual experimental processes and a description of the experimental results. This provides a clear and unified calculation method for the recovery factors of oil displacement processes, which often involve many difficult-to-compare processes.