bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduzierte Arenkomplexe von Hafnium mit einem Triamidoaminliganden
Authors: Ghana Priyabrata , Schrader Sebastian , Rajeshkumar Thayalan , Spaniol Thomas P. , Englert Ulli , Maron Laurent , Okuda Jun 
Published: April 2021

AbstractHafniumkomplexe mit reduzierten Arenen der Formel [K(L)][Hf(Xy‐N3N)(Aren)] (Xy‐N3N={(3,5‐Me2C6H3)NCH2CH2}3N3−, L=THF, 18‐Krone‐6; Ar=C10H82−, C14H102−) ahmen die Chemie von Hafnium in seiner formalen Oxidationsstufe +II nach. Alle Verbindungen wurden nach Reduktion des Chloridokomplexes [HfCl(Xy‐N3N)(THF)] mit zwei Äquivalenten Kaliumnaphthalinid oder ‐anthracenid erhalten. Die reduzierende Natur und die Basizität des reduzierten Anthracenliganden wurden bei der Reaktion von Benzonitril und Azobenzol bzw. durch Deprotonierung von tert‐Butylacetylen untersucht. Die Reduktion von Benzonitril liefert ein anfängliches doppeltes Insertionsprodukt zweier Nitrile unter kinetischer Kontrolle, das nach Abgabe eines der inserierten Nitrile zu einem Hafniumimidokomplex als thermodynamisches Produkt umlagert. Die Reduktion von Azobenzol führte zu einem Diphenylhydrazido(2−)‐Komplex. Die Umsetzung von terminalen Alkinen mit dem Anthracen‐ oder Diphenylhydrazido(2−)‐Komplex führte zur selektiven Protonierung des entsprechenden dianionischen Liganden.
Preparation, characterization, and in vitro bioactivity of magnetic co‐polymer [N, N‐dimethylaminopropylacrylamide‐co‐1‐allylimidazole] as a new nanocarrier for delivery of cefotaxime
Authors: Alipour Arash , Babaei Shekardasht Mehrnaz , Gharbani Parvin 
Published: April 2021

AbstractIn this research, new magnetic nanoparticles (MNPs) conjugated radical co‐polymerization with N, N‐dimethylaminopropylacrylamide (N, N‐DMAPAAm) as a thermosensitive monomer and 1‐allylimidazole (AI) as a cross‐linker agent was prepared as a magnetic nanocomposite (MNC). The synthesized MNC were characterized by Fourier transform infrared spectroscopy, Elemental analysis (CHN), Field emission scanning electron microscopy, Vibrating Sample Magnetometer, and Thermo Gravimetric Analysis. Cefotaxime was selected as a model drug and was loaded into the synthesized polymer. The main factors of adsorption process such as pH, contact time, temperature, and eluent were evaluated and optimized. The mechanism of cefotaxime adsorption is explained by Langmuir isotherm. Also, in vitro cefotaxime delivery in the simulated gastric and intestinal fluids was investigated. The drug release profile revealed that about 30.35% of the adsorbed cefotaxime was released in the first 30 min. at pH =1.2 (simulated gastric fluid) and 62.65% was released during 15 h at pH =7.4 (simulated intestinal fluid).
Ancestry‐based variation in maxillary sinus anatomy: Implications for health disparities in sinonasal disease
Authors: Kim Suhhyun , Ward Lyndee A. , Butaric Lauren N. , Maddux Scott D. 
Published: April 2021

AbstractParanasal sinus drainage is mediated by mucociliary transport and gravity. However, human orthograde posture, along with the superior positioning of the maxillary sinus (MS) ostium, increases reliance on the mucociliary system. Previous research has thus suggested that differences in MS size and shape may impede mucociliary clearance, potentially contributing to disparities in sinusitis susceptibility. To further investigate this hypothesis, this study collected 29 three‐dimensional (3D) coordinate landmarks and seven linear measurements of MS morphology from 167 computed tomography (CT) scans of crania of European, East Asian, or Equatorial African ancestry. MANOVA results reveal the Asian‐derived individuals are characterized by both a significantly taller MS (F = 14.15, p <  0.0001) and a significantly greater distance from the MS floor to the ostium (F = 17.22, p <  0.0001) compared to those of European and African ancestry. A canonical variate (CV) analysis conducted on 3D landmark data provides corroborative results, distinguishing Asian‐derived individuals predominantly on the basis of a relatively lower MS floor. As a greater distance between the MS floor and ostium may impede mucociliary clearance, our results suggest MS anatomy may be a more prominent factor in chronic sinusitis among individuals of Asian ancestry compared to those of European and African ancestries. This provides tentative evidence of an anatomical etiology for chronic sinusitis even in the absence of anatomical variants/abnormalities (e.g., nasal polyps, concha bullosa, Haller's cells, and Agger nasi cells). Further research into the relationship between MS anatomy and sinusitis, in addition to socioeconomic inequalities of healthcare, is warranted to continue evaluating possible contributions to health disparities.
Morphometric and structural analysis of Florida manatee spermatozoa
Authors: Cowart Jonathan R. , Collins Danielle M. , Stanton Daniel L. , van der Horst Gerhard , Larkin Iskande V. 
Published: April 2021

AbstractSperm characteristics, such as sperm morphology and sperm morphometry are important in assessing sperm quality. This is especially important for the management and conservation of endangered and exotic species, like the Florida manatee, where information of this nature is extremely limited. In this study, we fill this knowledge gap to better understand the reproductive physiology of Florida manatees by conducting the first extensive analysis of sperm morphometry and ultrastructure. Sperm were retrieved from the vas deferens of nine recently deceased Florida manatees. Computer‐aided sperm morphology analysis (CASMA) was used for morphometric analysis and laser‐scanning confocal microscopy and electron microscopy were used for structural and ultrastructural characterization. Our findings reveal new morphometric and structural data for the Florida manatee spermatozoon. Twelve morphometric features of Florida manatee sperm were quantified with some approximately 1.5–2 times larger than those previously reported. Ultrastructurally, the Florida manatee spermatozoon followed a mammalian structural pattern with an ovate‐shaped head, midpiece containing 84–90 mitochondria, and a flagellum. However, unique ultrastructural features were identified. Distinct, rectangular‐like enlargement of four outer dense fibers surrounding the axoneme was evident, which may provide additional tensile strength to counteract the forces on sperm transiting the female reproductive tract. Likewise, strong localization of F‐actin fibers within the midpiece may function to maintain sperm integrity within the female reproductive tract. These findings highlight the potential effects of sexual selective pressures on sperm size and structure in the Florida manatee and provide avenues for research on the occurrence of sperm competition in this species.
Graphene quantum dots prepared from dried lemon leaves and microcrystalline mosaic structure
Authors: Kir Şifa , Dehri İlyas , Önal Yunus , Esen Ramazan 
Published: April 2021

AbstractThe aim of this study is to obtain graphene quantum dots (GQDs) by using Citrus limonum leaves grown in Adana Province, Mediterranean region. Thus, dried Citrus limonum leaves were subjected to carbonization at temperatures of 200, 275, 350, 425 and 500°C and 90, 180, and 270 min respectively at each temperature. Characterization of the material obtained at the end of the process was determined by using X‐ray diffraction (XRD), Fourier‐transform infrared (FT‐IR), fluorescence spectroscopy, elemental analyzer, scanning electron microscopy (SEM), ultraviolet (UV)‐visible, UV‐A and UV‐C lamps. It was determined that the samples obtained in the carbonization process carried out at 350 and 425°C for 3 h made blue colored fluorescence. The results of the experiments completed for characterization analysis verified the GQDs and mosaic crystal structure compared to the literature. It was observed that the GQDs obtained at 350°C for 3 h had maximum fluorescence properties. Radical changes at the sample matrix was observed when carbonization temperature changed from 350°C to 425°C.
The effect of exogenous ciliary neurotrophic factor on cell cycle and neural differentiation markers of in vitro model cells: New insights for future therapeutic approaches
Authors: Ghasemi Maryam , Alizadeh Effat , Motlagh Behzad Fallahi , Zarghami Nosratollah 
Published: April 2021

Retinoblastoma is known as childhood rare malignancy of the retina. Ciliary neurotrophic factor (CNTF) was previously found to reduce degeneration and promote retina survival. This work investigated the effects of CNTF supplementation on in‐vitro model cells including retinoblastoma (Y79) and adipose‐derived mesenchymal stem cells (AMSCs) viability, proliferation, gene expression and cell cycle. A drop of viability was detected in Y79 treated with CNTF in a dose‐dependent manner (P < .05). However, the proliferation of AMSCs was increased at lower concentrations of CNTF (5 ng/mL), but declined in higher doses (50 and 100 ng/mL). The BrdU assay confirmed the MTT assay results. Cell cycle was arrested in both Y79 and AMSCs in the G0/G1 phase by CNTF treatment. A considerable down‐regulation of Bcl2, CycD1 and N‐Myc genes expression (P < .05) inversely, P15 and P21 genes up‐regulation in treated Y79 cells was observed. Besides, stemness genes' transcription was reduced in AMSCs (P < .05), and levels of neuronal‐specific markers such as neuron‐specific enolase (NSE) and neuronal nuclei (NeuN) were increased (P < .05). The findings of this study suggest a promising potential of CNTF in terms of arresting Y79 retinoblastoma cells, and differentiation‐inducing to AMSCs, which could be valuable for managing future innovative treatments targeting retinoblastoma.Significance of the studyWe demonstrate that CNTF has the potential to reduce proliferation of Y79 cells and induce the cell cycle arrest of them. Also, down‐regulation of oncogenes (such as N‐Myc) while up‐regulation of tumour suppressor genes (such as P21) was detected by exposure of Y79 cells to CNTF. Furthermore, we observed the cell cycle arrest, reduction of stemness gene and up‐regulation of neural differentiation markers in AMSCs treated with CNTF. These results support the probable promising effects of CNTF for controlling retinoblastoma.
Recent Advances in the Value Addition of Biomass‐Derived Levulinic Acid: A Review Focusing on its Chemical Reactivity Patterns
Authors: Dutta Saikat , Bhat Navya Subray 
Published: April 2021

AbstractLevulinic acid (LA) is one of the most prominent biomass‐derived chemical building blocks that can be transformed into specialty chemicals like fuels, solvents, monomers for polymers, plasticizers, surfactants, agrochemicals, and pharmaceuticals. Over the past three decades, an enormous amount of research data have been acquired on the preparation and downstream value addition of LA, and these works have been reviewed. However, considering the astonishing number of publications appearing every year on LA derivatives, the periodical review of recent works focusing on unique aspects of chemistry must be undertaken to critically evaluate the achievements to date, reassess the challenges, and recognize new opportunities. This review discusses the chemical‐catalytic synthesis of various derivatives of LA by focusing on its functionalities and reactivity patterns. Recent literature on some crucial derivatives such as γ‐valerolactone, 4,4’‐diphenolic acid, and ethyl levulinate have been tabulated and discussed. The synthetic interconversion between various derivatives, mechanistic insights, critical analysis of the reaction parameters toward selective preparation of various derivatives, and their potential commercial applications have been elaborated using predominantly heterogeneous catalysts. A critical assessment of the relative advantages and shortcomings of the existing synthetic strategies for various derivatives of LA has been presented to enkindle fresh ideas.
Generation of Droplets in Double T‐Shaped Microchannels with Necked Structures
Authors: Zhang Yaolong , Chen Xueye , Han Wenbo 
Published: April 2021

AbstractMicrofluidic droplets are widely applied in various fields such as biomedicine, aerospace, energy utilization, and chemical engineering due to their advantages of large specific surface area, uniform size, stability, and easy control. The double T‐shaped microchannel has the characteristics of rapid preparation of microdroplets with controllable size and good uniformity. Through 3D numerical simulation, the influence of the constriction structure of the microchannel on the formation of droplets was studied qualitatively and quantitatively. Compared with ordinary double T‐shaped microchannels, the microchannels with a necked structure generate smaller droplets in diameter and faster generation frequency. Among the three structures of rectangular necking, inverted trapezoidal necking, and trapezoidal necking, the microchannel with the latter structure has the best performance, can produce monodisperse droplets of uniform size, and the period is stable.
Multi‐scale modelling of monolith reactors: A 30‐year perspective from 1990 to 2020
Authors: Hayes Robert E. , Cornejo Ivan 
Published: April 2021

AbstractThe honeycomb type monolith reactor dominates the field of catalytic automotive exhaust gas after treatment systems and is increasingly being used in other applications. Advanced computational modelling of such systems can provide valuable insight into their operating characteristics and be used as a design tool. This reactor provides an excellent example of a multi‐scale modelling challenge with many complexities. This paper provides a perspective on the development and use of computational modelling tools in this context over the last 30 years, with an emphasis on the work published by the researchers at the University of Alberta. This paper covers all aspects of model development, including single channel and full‐scale reactor models and inter and intra mass and heat transfer effects, with the latter including radiation.
Emulsion polymerization of vinylidene fluoride: Effects of mixing and reaction conditions on the initial rate of polymerization
Authors: Ecoscia Ana Carolina M. , Sheibat‐Othman Nida , McKenna Timothy F. L. 
Published: April 2021

AbstractIn order to contribute to a better understanding of the emulsion polymerization of vinylidene fluoride (VDF), an experimental study under conditions of temperature and pressure similar to those found in industrial processes was carried out. It is shown that the initial rate of polymerization is strongly influenced by the agitation of the reactor, with the rate of reaction increasing as the rate of agitation increases. In addition, using a more efficient impeller also increases the polymerization. It is proposed that this is due to mass transfer limitations. This idea is confirmed by a similar dependence of the average molecular weight on agitation. Experimental data also shows that particles are formed by homogeneous coagulative nucleation. It is proposed that particle nucleation occurs throughout the polymerization, and that a competition between controlled coagulation and particle generation governs the rate of reaction.
Detection of periodontal bone loss in mandibular area from dental panoramic radiograph using image processing techniques
Authors: Vigil M. S. Antony , Bharathi V. Subbiah 
Published: April 2021

AbstractMedical imaging plays the vital role in diagnosis of abnormalities. Periodontitis is a common chronic inflammatory disease damaging the soft tissue that untreated can lead to loss of bone, which supports the teeth. The severity of periodontitis is correlated to pocket depth in alveolar area. Even if analyses of the pocket depth can be manually performed, an automatic assistive tool can drastically help radiologists conduct more accurate analyses. In the proposed research, image processing algorithms were developed to compute pocket depth and diagnose the periodontitis. Radiologists manually segmented 350 panoramic radiographic images, dividing them into normal and periodontitis. The same dataset is used in our work to validate the Classification algorithm. The images are preprocessed with median filter and histogram equalization to improve the contrast and then segmented using two‐dimensional‐Otsu thresholding method into teeth and bony area in the mandibular region. Normal pocket depth of 3 mm as reported by American Academy of Periodontology is equivalently converted to pixel height in the radiographic images. Based on this pocket depth rule based classification method classifies the images into normal and periodontitis. The proposed work achieved 91.34% accuracy, 92.8% sensitivity, and 95.47% F‐score in classifying the dental panoramic radiography.
Detecting cells rotations for increasing the robustness of cell sizing by impedance measurements, with or without machine learning
Authors: Taraconat Pierre , Gineys Jean‐Philippe , Isèbe Damien , Nicoud Franck , Mendez Simon 
Published: April 2021

AbstractThe Coulter principle is a widespread technique for sizing red blood cells (RBCs) in hematological analyzers. It is based on the monitoring of the electrical perturbations generated by cells passing through a micro‐orifice, in which a concentrated electrical field is imposed by two electrodes. However, artifacts associated with near‐wall passages in the sensing region are known to skew the statistics for RBCs sizing. This study presents numerical results that emphasize the link between the cell flow‐induced rotation in the detection area and the error in its measured volume. Based on these observations, two methods are developed to identify and reject pulses impaired by cell rotation. In the first strategy, the filtering is allowed by a metric computed directly from the waveform. In the second, a numerical database is employed to train a neural network capable of detecting if the cell has experienced a rotation, given its electrical pulse. Detecting and rejecting rotation‐associated pulses are shown to provide results comparable to hydrodynamical focusing, which enforces cells to flow in the center of the orifice, the gold standard implementation of the Coulter principle.
Constitutive expression of spliced XBP1 causes perinatal lethality in mice
Authors: Xu Qian , Zhang Hua , Wang Suzhen , Qin Chunlin , Lu Yongbo 
Published: April 2021

SummaryUpon endoplasmic reticulum (ER) stress, inositol‐requiring enzyme 1 (IRE1) is activated and catalyzes nonconventional splicing of an unspliced X‐box binding protein 1 (XBP1U) mRNA to yield a spliced XBP1 (XBP1S) mRNA that encodes a potent XBP1S transcription factor. XBP1S is a key mediator of the IRE1 branch that is essential for alleviating ER stress. We generated a novel mouse strain (referred to as “Xbp1CS/+” mice) that constitutively expressed XBP1S after Cre recombinase‐mediated recombination. Further breeding of these mice with Twist2 Cre recombinase (Twist2‐Cre) knock‐in mice generated Twist2‐Cre;Xbp1CS/+ mice. Most Twist2‐Cre;Xbp1CS/+ mice died shortly after birth. Reverse‐transcription polymerase chain reaction (RT‐PCR) showed that constitutive expression of XBP1S occurred in various mouse tissues examined, but not in the brain. Immunohistochemistry confirmed that although the immunostaining signals for total XBP1 (XBP1U and XBP1S) were found in the calvarial bones in both Twist2‐Cre;Xbp1CS/+ and control mice, the signals for XBP1S were only detected in the Twist2‐Cre;Xbp1CS/+ mice, but not in the control mice. These results suggest that a precise control of XBP1S production is essential for normal mouse development.
Larval anurans follow predictions of stoichiometric theory: implications for nutrient storage in wetlands
Authors: Knapp Daniel D. , Smith Lora L. , Atkinson Carla L. 
Published: April 2021

AbstractEcological stoichiometry provides a framework to predict how animals regulate nutritional balances within their tissue and, as a result, how animal biomass affects ecosystem processes through nutrient cycling. However, most interspecific and developmental stoichiometric studies in animals focus on invertebrates, and the few vertebrate studies are largely fish‐centric. Larval anurans are ideal vertebrates to test predictions of developmental and interspecific stoichiometry as they undergo a complex development, exhibit broad arrays of life‐history traits, and can constitute high animal biomass in wetlands, implying major roles in wetland nutrient storage and cycling. We examined (1) patterns of body stoichiometry across larval developmental stages within multiple anuran species, (2) whether key predictors of stoichiometric change, specifically body size, developmental period, and breeding season, influence interspecific stoichiometric variation, and (3) natural magnitudes and fluctuations of larval anuran nutrient storage in geographically isolated wetlands (GIWs). We measured carbon (C), nitrogen (N), and phosphorus (P) tissue content in larval anurans across five developmental stages within 11 species collected from four GIWs to examine patterns of developmental and interspecific stoichiometry. Within species, we found broad developmental stoichiometric patterns in which later developmental stages were lower in %N, but higher in %P than earlier stages. Patterns in %C were inconsistent but were generally lower in later stages, while tissue C:N ratios increased, and C:P and N:P decreased in later developmental stages. Interspecific stoichiometric variation was partially explained by body size and developmental period which positively affected %C and C:N ratios. We observed spatial and temporal fluctuations in species‐specific biomass which dictated nutrient storage patterns within larval anuran assemblages, though stoichiometric identity played a major role. Our estimated magnitudes of larval anuran areal nutrient storage also greatly exceeded that of other wetland fauna with the maximum estimated areal P storage reaching over 200 times that of a similar‐density co‐occurring invertebrate group. These results highlight stoichiometric patterns of development and interspecific variation in a diverse group of amphibians while providing critical baseline information for elucidating the role of anurans in wetland nutrient dynamics.