bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrent Intraocular Lens Dislocation in a Patient with Familial Ectopia Lentis
Authors: Wilczyński Tomasz K. , Niewiem Alfred , Leszczyński Rafał , Michalska-Małecka Katarzyna
Published: April 2021

A 36-year-old patient presented to the hospital with recurrent dislocation of the intraocular lens (IOL). The patient with the diagnosis of familial ectopia lentis was first operated on for crystalline lens subluxation in the left eye in 2007 and in the right eye in 2009. In both eyes, lens extraction with anterior vitrectomy and transscleral fixation of a rigid IOL was performed. In 2011, the IOL in the right eye luxated into the vitreous cavity due to ocular trauma. The patient underwent a pars plana vitrectomy with the IOL resuturation to the sclera. Seven years later, a spontaneous vision loss in the right eye was caused by a retinal detachment. The pars plana vitrectomy with silicone oil tamponade and a consequential oil removal three months later were performed in 2018. The follow-up examination revealed recurrent IOL dislocation in the same eye. Due to a history of previous suture-related complications a decision was made to remove the subluxated rigid polymethyl-methacrylate (PMMA) IOL and fixate to sclera a sutureless SOLEKO FIL SSF Carlevale lens. The purpose of this report is to present a single case of a 36-year-old patient who was presented to the hospital with recurrent dislocation of the intraocular lens. In a three-month follow-up period, a good anatomical and functional outcome was finally obtained with transscleral sutureless intraocular lens. This lens is an option worth considering especially in a young patient with a long life expectancy and physically active.
Proposed Environmental Risk Management Elements in a Carpathian Valley Basin, within the Roşia Montană European Historical Mining Area
Authors: Bănăduc Doru , Curtean-Bănăduc Angela , Cianfaglione Kevin , Akeroyd John , Cioca Lucian-Ionel
Published: April 2021

Non-ferrous metals mining activities have long accompanied people, and began in the study area of South East Europe over 2000 years ago. The environment quality is significantly affected by both historic mining activities and contemporary impacts. All these problems, inducing synergic negative effects on local organism communities, have created a chronic state of pollution. The Corna Valley has one of the oldest historical human impacts in Romania due to the influence of mining. Fish and benthic macroinvertebrates have exhibited significant responses to long term mining effects on lotic systems. The analysis of macroinvertebrate communities, correlated with the lack of fish and some biotope characteristics, indicates that the Corna River presents a variety of categories of ecological status between sectors. The lack of fish reveals the poor ecological conditions. Technical and management solutions are proposed here to diminish the historical environmental problems and to avoid future ecological accidents, especially in an attempt to improve any construction plan concerning a possible new de-cyanidation dam and lake. Fish and benthic macroinvertebrates have exhibited significant responses to long term mining effects on lotic systems. Two management zones were identified, an upper zone which can be used as a reference area and a lower zone, where pollution remedial activities are proposed.
SARS-CoV-2 Viral Entry Proteins in Hyperandrogenemic Female Mice: Implications for Women with PCOS and COVID-19
Authors: Huffman Alexandra M. , Rezq Samar , Basnet Jelina , Yanes Cardozo Licy L. , Romero Damian G.
Published: April 2021

SARS-CoV-2, the causative agent of COVID-19, infects host cells using the angiotensin I converting enzyme 2 (ACE2) as its receptor after priming by host proteases, including TMPRSS2. COVID-19 affects multiple organ systems, and male patients suffer increased severity and mortality. Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in reproductive-age women and is characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. PCOS is associated with obesity and cardiometabolic comorbidities, both being risk factors associated with severe COVID-19 pathology. We hypothesize that elevated androgens in PCOS regulate SARS-CoV-2 entry proteins in multiple tissues increasing the risk for this population. Female mice were treated with dihydrotestosterone (DHT) for 90 days. Body composition was measured by EchoMRI. Fasting glucose was determined by an enzymatic method. mRNA and protein levels of ACE2, Tmprss2, Cathepsin L, Furin, Tmprss4, and Adam17 were quantified by RT-qPCR, Western-blot, or ELISA in tissues, serum, and urine. DHT treatment increased body weight, fat and lean mass, and fasting glucose. Ace2 mRNA was upregulated in the lung, cecum, heart, and kidney, while downregulated in the brain by DHT. ACE2 protein was upregulated by DHT in the small intestine, heart, and kidney. The SARS-CoV-2 priming proteases Tmprss2, Cathepsin L, and Furin mRNA were upregulated by DHT in the kidney. ACE2 sheddase Adam17 mRNA was upregulated by DHT in the kidney, which corresponded with increased urinary ACE2 in DHT treated mice. Our results highlight the potential for increased cardiac, renal, and gastrointestinal dysfunction in PCOS women with COVID-19.
Drug Response Diversity: A Hidden Bacterium?
Authors: Hannachi Nadji , Camoin-Jau Laurence
Published: April 2021

Interindividual heterogeneity in response to treatment is a real public health problem. It is a factor that can be responsible not only for ineffectiveness or fatal toxicity but also for hospitalization due to iatrogenic effects, thus increasing the cost of patient care. Several research teams have been interested in what may be at the origin of these phenomena, particularly at the genetic level and the basal activity of organs dedicated to the inactivation and elimination of drug molecules. Today, a new branch is being set up, explaining the enigmatic part that could not be explained before. Pharmacomicrobiomics attempts to investigate the interactions between bacteria, especially those in the gut, and drug response. In this review, we provide a state of the art on what this field has brought as new information and discuss the challenges that lie ahead to see the real application in clinical practice.
Improving the Hydrophilicity of Flexible Polyurethane Foams with Sodium Acrylate Polymer
Authors: Borreguero Ana M. , Zamora Javier , Garrido Ignacio , Carmona Manuel , Rodríguez Juan F.
Published: April 2021

Hydrophilic, flexible polyurethane (FPU) foams made from Hypol prepolymers are capable of retaining large amounts of water and saline solutions. The addition of different catalysts and surfactant agents to Hypol JM 5008 prepolymer was assayed to obtain a foam with good structural stability and elasticity. The combination of three catalysts, stannous octoate and two amine-based ones (Tegoamin 33 and Tegoamin BDE), and the surfactant Niax silicone L-620LV allowed to synthesize a foam with a homogeneous cell size distribution, exhibiting the highest saline absorption capacity (2.4 g/gram of foam) and almost complete shape recovery, with up to a 20% of remaining deformation. Then, superabsorbent sodium acrylate polymer (PNaA) was added to the FPU foam up to 8 pph. The urine absorption capacity of the foam was increased about 24.8% by incorporating 6 pph of PNaA, absorbing 17.46 g of saline solution per foam gram, without any negative impact on the rest of the foam properties. All these properties make the synthesized foams suitable for corporal fluids absorption applications in which elasticity and low-density are required.
Fiber-Templated 3D Calcium-Phosphate Scaffolds for Biomedical Applications: The Role of the Thermal Treatment Ambient on Physico-Chemical Properties
Authors: Mocanu Aura-Cătălina , Miculescu Florin , Stan George E. , Pandele Andreea-Mădălina , Pop Mihai Alin , Ciocoiu Robert Cătălin , Voicu Ștefan Ioan , Ciocan Lucian-Toma
Published: April 2021

A successful bone-graft-controlled healing entails the development of novel products with tunable compositional and architectural features and mechanical performances and is, thereby, able to accommodate fast bone in-growth and remodeling. To this effect, graphene nanoplatelets and Luffa-fibers were chosen as mechanical reinforcement phase and sacrificial template, respectively, and incorporated into a hydroxyapatite and brushite matrix derived by marble conversion with the help of a reproducible technology. The bio-products, framed by a one-stage-addition polymer-free fabrication route, were thoroughly physico-chemically investigated (by XRD, FTIR spectroscopy, SEM, and nano-computed tomography analysis, as well as surface energy measurements and mechanical performance assessments) after sintering in air or nitrogen ambient. The experiments exposed that the coupling of a nitrogen ambient with the graphene admixing triggers, in both compact and porous samples, important structural (i.e., decomposition of β-Ca3(PO4)2 into α-Ca3(PO4)2 and α-Ca2P2O7) and morphological modifications. Certain restrictions and benefits were outlined with respect to the spatial porosity and global mechanical features of the derived bone scaffolds. Specifically, in nitrogen ambient, the graphene amount should be set to a maximum 0.25 wt.% in the case of compact products, while for the porous ones, significantly augmented compressive strengths were revealed at all graphene amounts. The sintering ambient or the graphene addition did not interfere with the Luffa ability to generate 3D-channels-arrays at high temperatures. It can be concluded that both Luffa and graphene agents act as adjuvants under nitrogen ambient, and that their incorporation-ratio can be modulated to favorably fit certain foreseeable biomedical applications.
Virtual Experiments of Particle Mixing Process with the SPH-DEM Model
Authors: Zhu Siyu , Wu Chunlin , Yin Huiming
Published: April 2021

Particle mixing process is critical for the design and quality control of concrete and composite production. This paper develops an algorithm to simulate the high-shear mixing process of a granular flow containing a high proportion of solid particles mixed in a liquid. DEM is employed to simulate solid particle interactions; whereas SPH is implemented to simulate the liquid particles. The two-way coupling force between SPH and DEM particles is used to evaluate the solid-liquid interaction of a multi-phase flow. Using Darcy’s Law, this paper evaluates the coupling force as a function of local mixture porosity. After the model is verified by two benchmark case studies, i.e., a solid particle moving in a liquid and fluid flowing through a porous medium, this method is applied to a high shear mixing problem of two types of solid particles mixed in a viscous liquid by a four-bladed mixer. A homogeneity metric is introduced to characterize the mixing quality of the particulate mixture. The virtual experiments with the present algorithm show that adding more liquid or increasing liquid viscosity slows down the mixing process for a high solid load mix. Although the solid particles can be mixed well eventually, the liquid distribution is not homogeneous, especially when the viscosity of liquid is low. The present SPH-DEM model is versatile and suitable for virtual experiments of particle mixing process with different blades, solid particle densities and sizes, and liquid binders, and thus can expedite the design and development of concrete materials and particulate composites.
Mechanical Properties and Microstructure of Epoxy Mortars Made with Polyethylene and Poly(Ethylene Terephthalate) Waste
Authors: Dębska Bernardeta , Brigolini Silva Guilherme Jorge
Published: April 2021

The article describes the results of a study to determine the simultaneous effect of polyethylene terephthalate waste (PET) and polyethylene (PE) on the strength characteristics and bulk density of epoxy mortars. In these mortars, 9 wt.% of the polymer binder was replaced by glycolysate which was made from PET waste and propylene glycol. Additionally, 0–10 vol.% of the aggregate was substituted with PE agglomerate made from plastic bags waste, respectively. The modification of the composition of epoxy mortar has a special environmental and economic aspect. It also allows to protect natural sources of the aggregate, while reducing the amount of waste and reducing problems arising from the need to store them. The resulting composite has very good strength properties. With the substitution of 9 wt.% of resin and 5 vol.% of sand, a flexural strength of 35.7 MPa and a compressive strength of 101.1 MPa was obtained. The results of the microstructure study of the obtained mortars constitute a significant part of the paper.
Exploration of D022-Type Al3TM(TM = Sc, Ti, V, Zr, Nb, Hf, Ta): Elastic Anisotropy, Electronic Structures, Work Function and Experimental Design
Authors: Zhang Guowei , Sun Fenger , Liu Heping , Ren Xiaoyan , Xu Hong , Wang Mingjie , Fu Yizheng
Published: April 2021

The structural properties, elastic anisotropy, electronic structures and work function of D022-type Al3TM (TM = Sc, Ti, V, Y, Zr, Nb, La, Hf, Ta) are studied using the first-principles calculations. The results indicate that the obtained formation enthalpy and cohesive energy of these compounds are in accordance with the other calculated values. It is found that the Al3Zr is the most thermodynamic stable compound. The mechanical property indexes, such as elastic constants, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, and Vickers hardness are systematically explored. Moreover, the calculated universal anisotropic index, percent anisotropy and shear anisotropic factors of D022-type Al3TM are analyzed carefully. It demonstrates that the shear modulus anisotropy of Al3La is the strongest, while that of Al3Ta is the weakest. In particular, the density of states at Fermi level is not zero, suggesting that these phases have metal properties and electrical conductivity. More importantly, the mechanisms of correlation between hardness and Young’s modulus are further explained by the work function. Finally, the experimental design proves that D022-Al3Ta has an excellent strengthening effect.
Ceramic Biomaterial Pores Stereology Analysis by the Use of Microtomography
Authors: Garczyk Żaneta , Jaegermann Zbigniew , Duda Piotr , Swinarew Andrzej S. , Stach Sebastian
Published: April 2021

The main aim of this study was to analyze microtomographic data to determine the geometric dimensions of a ceramic porous material’s internal structure. Samples of a porous corundum biomaterial were the research material. The samples were prepared by chemical foaming and were measured using an X-ray scanner. In the next stage, 3D images of the samples were generated and analyzed using Thermo Scientific Avizo software. The analysis enabled the isolation of individual pores. Then, the parameters characterizing the pore geometry and the porosity of the samples were calculated. The last part of the research consisted of verifying the developed method by comparing the obtained results with the parameters obtained from the microscopic examinations of the biomaterial. The comparison of the results confirmed the correctness of the developed method. The developed methodology can be used to analyze biomaterial samples to assess the geometric dimensions of biomaterial pores.
Cutting Forces in Peripheral Up-Milling of Particleboard
Authors: Pałubicki Bartosz
Published: April 2021

An analysis of forces acting in the peripheral up-milling of particleboard is presented. First, a novel method of high-frequency piezoelectric force signal treatment is proposed and used to separate the original force signal from the vibrations of the previous cutting iteration. This allows for the analysis of single chip cutting force courses during industrial CNC (Computer Numerical Control) milling. The acting forces are compared with the theoretical, instantaneous, uncut chip thickness. The results show that, for a range of 40–60 m/s, the higher the cutting speed used, the higher the resultant and principal cutting forces. The method of cutting thrust force used was similar to that observed in solid wood milling, i.e., first using a pushing action, followed by a pulling action. The obtained average specific principal cutting forces for particleboard peripheral up-milling are equal to 32.0 N/mm2 for slow and 37.6 N/mm2 for fast milling. The specific cutting thrust force decreases with the increase in instantaneous uncut chip thickness.
Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders
Authors: Yang Yimin , Li Xiaoying , Liu Ziyu , Hu Dianjun , Liu Xin , Chen Penghui , Tian Feng , Zhu Danyang , Zhang Lixuan , Li Jiang
Published: April 2021

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.
Beneficial Effect of Left Ventricular Remodeling after Early Change of Sacubitril/Valsartan in Patients with Nonischemic Dilated Cardiomyopathy
Authors: Kim Hyue-Mee , Kim Kyung-Hee , Park Jin-Sik , Oh Byung-Hee
Published: April 2021

Background and Objectives: Evidence for effectiveness of early change from angiotensin II receptor blockers (ARBs) or angiotensin-converting enzyme inhibitors (ACEIs) to sacubitril/valsartan is lacking. We aimed to investigate whether early changes to sacubitril/valsartan could improve outcomes in patients with nonischemic dilated cardiomyopathy (DCM) in real-world practice. Materials and Methods: A total of 296 patients with nonischemic DCM who were treated with ARB or ACEI continuously (group A, n = 150) or had their medication switched to sacubitril/valsartan (group S, n = 146) were included. The sacubitril/valsartan group was divided into early change (within 60 days, group S/E, n = 59) and late change (group S/L, n = 87) groups. Changes in echocardiographic parameters from the time of initial diagnosis to the last follow-up were analyzed. Results: Patients in group S showed greater left ventricular (LV) end-diastolic dimension (EDD) (group A vs. S, 61.7 ± 7.4 vs. 66.5 ± 8.0, p < 0.001) and lower LV ejection fraction (LVEF) (28.9 ± 8.2% vs. 23.9 ± 7.5%, p < 0.001) than those in group A at initial diagnosis. During a median follow-up of 76 months, patients in group S/E, ∆ LVEF (%) and ∆ LVESD (mm) were significantly improved compared with those in patients in group A (group A vs. S/E, ∆ LVEF, p = 0.036; ∆ LVESD, p = 0.023) or S/L (group S/E vs. S/L, ∆ LVEF, p = 0.05; ∆ LVESD, p = 0.005). Among patients whose medications were switched to sacubitril/valsartan, those with an earlier change showed a significant correlation with greater LVEF improvement (r = −0.367, p < 0.001) and LV reverse remodeling (r = 0.277, p < 0.001). Conclusions: in patients with nonischemic DCM, an early switch to sacubitril/valsartan was associated with greater improvement in LV function. Patients might benefit in terms of LV function by early switching to sacubitril/valsartan.
Removal of Cd(II) from Micro-Polluted Water by Magnetic Core-Shell Fe3O4@Prussian Blue
Authors: Long Xinxin , Chen Huanyu , Huang Tijun , Zhang Yajing , Lu Yifeng , Tan Jihua , Chen Rongzhi
Published: April 2021

A novel core-shell magnetic Prussian blue-coated Fe3O4 composites (Fe3O4@PB) were designed and synthesized by in-situ replication and controlled etching of iron oxide (Fe3O4) to eliminate Cd (II) from micro-polluted water. The core-shell structure was confirmed by TEM, and the composites were characterized by XRD and FTIR. The pore diameter distribution from BET measurement revealed the micropore-dominated structure of Fe3O4@PB. The effects of adsorbents dosage, pH, and co-existing ions were investigated. Batch results revealed that the Cd (II) adsorption was very fast initially and reached equilibrium after 4 h. A pH of 6 was favorable for Cd (II) adsorption on Fe3O4@PB. The adsorption rate reached 98.78% at an initial Cd (II) concentration of 100 μg/L. The adsorption kinetics indicated that the pseudo-first-order and Elovich models could best describe the Cd (II) adsorption onto Fe3O4@PB, indicating that the sorption of Cd (II) ions on the binding sites of Fe3O4@PB was the main rate-limiting step of adsorption. The adsorption isotherm well fitted the Freundlich model with a maximum capacity of 9.25 mg·g−1 of Cd (II). The adsorption of Cd (II) on the Fe3O4@PB was affected by co-existing ions, including Cu (II), Ni (II), and Zn (II), due to the competitive effect of the co-adsorption of Cd (II) with other co-existing ions.
Comparison of the Effects of Conching Parameters on the Contents of Three Dominant Flavan3-ols, Rheological Properties and Sensory Quality in Chocolate Milk Mass Based on Liquor from Unroasted Cocoa Beans
Authors: Urbańska Bogumiła , Kowalska Hanna , Szulc Karolina , Ziarno Małgorzata , Pochitskaya Irina , Kowalska Jolanta
Published: April 2021

The content of polyphenols in chocolate depends on many factors related to the properties of raw material and manufacturing parameters. The trend toward developing chocolates made from unroasted cocoa beans encourages research in this area. In addition, modern customers attach great importance to how the food they consume benefits their bodies. One such benefit that consumers value is the preservation of natural antioxidant compounds in food products (e.g., polyphenols). Therefore, in our study we attempted to determine the relationship between variable parameters at the conching stage (i.e., temperature and time of) and the content of dominant polyphenols (i.e.,catechins, epicatechins, and procyanidin B2) in chocolate milk mass (CMM) obtained from unroasted cocoa beans. Increasing the conching temperature from 50 to 60 °C decreased the content of three basic flavan-3-ols. The highest number of these compounds was determined when the process was carried out at 50 °C. However, the time that caused the least degradation of these compounds differed. For catechin, it was 2 h; for epicatechin it was 1 h; and for procyanidin it was 3 h. The influence of both the temperature and conching time on the rheological properties of chocolate milk mass was demonstrated. At 50 °C, the viscosity and the yield stress of the conched mass showed its highest value.
Identification of Novel Inhibitors of Escherichia coli DNA Ligase (LigA)
Authors: Alomari Arqam , Gowland Robert , Southwood Callum , Barrow Jak , Bentley Zoe , Calvin-Nelson Jashel , Kaminski Alice , LeFevre Matthew , Callaghan Anastasia J. , Vincent Helen A. , Gowers Darren M.
Published: April 2021

Present in all organisms, DNA ligases catalyse the formation of a phosphodiester bond between a 3′ hydroxyl and a 5′ phosphate, a reaction that is essential for maintaining genome integrity during replication and repair. Eubacterial DNA ligases use NAD+ as a cofactor and possess low sequence and structural homology relative to eukaryotic DNA ligases which use ATP as a cofactor. These key differences enable specific targeting of bacterial DNA ligases as an antibacterial strategy. In this study, four small molecule accessible sites within functionally important regions of Escherichia coli ligase (EC-LigA) were identified using in silico methods. Molecular docking was then used to screen for small molecules predicted to bind to these sites. Eight candidate inhibitors were then screened for inhibitory activity in an in vitro ligase assay. Five of these (geneticin, chlorhexidine, glutathione (reduced), imidazolidinyl urea and 2-(aminomethyl)imidazole) showed dose-dependent inhibition of EC-LigA with half maximal inhibitory concentrations (IC50) in the micromolar to millimolar range (11–2600 µM). Two (geneticin and chlorhexidine) were predicted to bind to a region of EC-LigA that has not been directly investigated previously, raising the possibility that there may be amino acids within this region that are important for EC-LigA activity or that the function of essential residues proximal to this region are impacted by inhibitor interactions with this region. We anticipate that the identified small molecule binding sites and inhibitors could be pursued as part of an antibacterial strategy targeting bacterial DNA ligases.
Acute Consumption of Blueberries and Short-Term Blueberry Supplementation Improve Glucose Management and Insulin Levels in Sedentary Subjects
Authors: Palma Ximena , Thomas-Valdés Samanta , Cruz Gonzalo
Published: April 2021

Background: Blueberries are polyphenol-rich fruits with antioxidant and anti-inflammatory properties. Polyphenols from berries act by blocking digestive enzymes, reshaping gastrointestinal microbiota, and affecting the release of gastrointestinal hormones to regulate insulin dynamics and glucose management. However, most studies use fruit extracts instead of fresh fruit. We aimed to evaluate postprandial glucose management and antioxidant capacity of fresh blueberries consumed acutely or as a six-day supplementation in 10 sedentary subjects. Methods: To evaluate the effect of acute blueberry intake, 150 g of blueberries were consumed together with 150 g of white bread by the subject and blood samples were collected at 0, 30, 60, 90 and 120 min to measure glucose, insulin, and plasma antioxidant capacity. To evaluate supplementation, 150 g of blueberries were provided daily for six days and sample collection was performed at day 7. Results: Acute consumption of blueberries decreased postprandial glucose area under the curve (AUC) and increased insulin levels at 15 min timepoint. Supplementation did not affect glucose levels but decreased insulin levels at 120 min. No changes in antioxidant capacity were observed. Conclusions: Consumption of fresh blueberries improves postprandial glucose management presumably due to actions on the gastrointestinal tract, while supplementation improves insulin sensitivity, probably due antioxidant and anti-inflammatory effects.
Polymerized Albumin Receptor of Hepatitis B Virus for Evading the Reticuloendothelial System
Authors: Takagi Kurumi , Somiya Masaharu , Jung Joohee , Iijima Masumi , Kuroda Shun’ichi
Published: April 2021

Various strategies, such as optimization of surface chemistry, size, shape, and charge, have been undertaken to develop nanoparticles (NPs) as DDS (drug delivery system) nanocarriers for evading the reticuloendothelial system (RES) in vivo. We previously developed a hollow NP composed of hepatitis B virus (HBV) surface antigen L proteins and lipid bilayers, hereinafter referred to as bio-nanocapsule (BNC), as a nonviral DDS nanocarrier. Such a BNC harbors the HBV-derived human hepatic cell-specific infection mechanism, and intravenously injected BNCs by themselves were shown to avoid clearance by RES-rich organs and accumulate in target tissues. In this study, since the surface modification with albumins is known to prolong the circulation time of nanomedicines, we examined whether the polymerized albumin receptor (PAR) of BNCs contributes to RES evasion in mouse liver. Our results show that NPs conjugated with peptides possessing sufficient PAR activity were captured by Kupffer cells less efficiently in vitro and were able to circulate for a longer period of time in vivo. Comparing with polyethylene glycol, PAR peptides were shown to reduce the recognition by RES to equal content. Taken together, our results strongly suggest that the PAR domain of BNCs, as well as HBV, harbors an innate RES evasion mechanism. Therefore, the surface modification with PAR peptides could be an alternative strategy for improving the pharmacodynamics and pharmacokinetics of forthcoming nanomedicines.
A General Temperature-Dependent Stress–Strain Constitutive Model for Polymer-Bonded Composite Materials
Authors: Duan Xiaochang , Yuan Hongwei , Tang Wei , He Jingjing , Guan Xuefei
Published: April 2021

This study develops a general temperature-dependent stress–strain constitutive model for polymer-bonded composite materials, allowing for the prediction of deformation behaviors under tension and compression in the testing temperature range. Laboratory testing of the material specimens in uniaxial tension and compression at multiple temperatures ranging from −40 ∘C to 75 ∘C is performed. The testing data reveal that the stress–strain response can be divided into two general regimes, namely, a short elastic part followed by the plastic part; therefore, the Ramberg–Osgood relationship is proposed to build the stress–strain constitutive model at a single temperature. By correlating the model parameters with the corresponding temperature using a response surface, a general temperature-dependent stress–strain constitutive model is established. The effectiveness and accuracy of the proposed model are validated using several independent sets of testing data and third-party data. The performance of the proposed model is compared with an existing reference model. The validation and comparison results show that the proposed model has a lower number of parameters and yields smaller relative errors. The proposed constitutive model is further implemented as a user material routine in a finite element package. A simple structural example using the developed user material is presented and its accuracy is verified.
Data-Driven Approaches for Tornado Damage Estimation with Unpiloted Aerial Systems
Authors: Chen Zhiang , Wagner Melissa , Das Jnaneshwar , Doe Robert K. , Cerveny Randall S.
Published: April 2021

Tornado damage estimation is important for providing insights into tornado studies and assisting rapid disaster response. However, it is challenging to precisely estimate tornado damage because of the large volumes of perishable data. This study presents data-driven approaches to tornado damage estimation using imagery collected from Unpiloted Aerial Systems (UASs) following the 26 June 2018 Eureka Kansas tornado. High-resolution orthomosaics were generated from Structure from Motion (SfM). We applied deep neural networks (DNNs) on the orthomosaics to estimate tornado damage and assessed their performance in four scenarios: (1) object detection with binary categories, (2) object detection with multiple categories, (3) image classification with binary categories, and (4) image classification with multiple categories. Additionally, two types of tornado damage heatmaps were generated. By directly stitching the resulting image tiles from the DNN inference, we produced the first type of tornado damage heatmaps where damage estimates are accurately georeferenced. We also presented a Gaussian process (GP) regression model to build the second type of tornado damage heatmap (a spatially continuous tornado damage heatmap) by merging the first type of object detection and image classification heatmaps. The GP regression results were assessed with ground-truth annotations and National Weather Service (NWS) ground surveys. This detailed information can help NWS Weather Forecast Offices and emergency managers with their damage assessments and better inform disaster response and recovery.
Multiple Classifiers Based Semi-Supervised Polarimetric SAR Image Classification Method
Authors: Zhu Lekun , Ma Xiaoshuang , Wu Penghai , Xu Jiangong
Published: April 2021

Polarimetric synthetic aperture radar (PolSAR) image classification has played an important role in PolSAR data application. Deep learning has achieved great success in PolSAR image classification over the past years. However, when the labeled training dataset is insufficient, the classification results are usually unsatisfactory. Furthermore, the deep learning approach is based on hierarchical features, which is an approach that cannot take full advantage of the scattering characteristics in PolSAR data. Hence, it is worthwhile to make full use of scattering characteristics to obtain a high classification accuracy based on limited labeled samples. In this paper, we propose a novel semi-supervised classification method for PolSAR images, which combines the deep learning technique with the traditional scattering trait-based classifiers. Firstly, based on only a small number of training samples, the classification results of the Wishart classifier, support vector machine (SVM) classifier, and a complex-valued convolutional neural network (CV-CNN) are used to conduct majority voting, thus generating a strong dataset and a weak dataset. The strong training set are then used as pseudo-labels to reclassify the weak dataset by CV-CNN. The final classification results are obtained by combining the strong training set and the reclassification results. Experiments on two real PolSAR images on agricultural and forest areas indicate that, in most cases, significant improvements can be achieved with the proposed method, compared to the base classifiers, and the improvement is approximately 3–5%. When the number of labeled samples was small, the superiority of the proposed method is even more apparent. The improvement for built-up areas or infrastructure objects is not as significant as forests.
Dielectrophoresis Prototypic Polystyrene Particle Synchronization toward Alive Keratinocyte Cells for Rapid Chronic Wound Healing
Authors: Deivasigamani Revathy , Maidin Nur Nasyifa Mohd , Wee M. F. Mohd Razip , Mohamed Mohd Ambri , Buyong Muhamad Ramdzan
Published: April 2021

Diabetes patients are at risk of having chronic wounds, which would take months to years to resolve naturally. Chronic wounds can be countered using the electrical stimulation technique (EST) by dielectrophoresis (DEP), which is label-free, highly sensitive, and selective for particle trajectory. In this study, we focus on the validation of polystyrene particles of 3.2 and 4.8 μm to predict the behavior of keratinocytes to estimate their crossover frequency (fXO) using the DEP force (FDEP) for particle manipulation. MyDEP is a piece of java-based stand-alone software used to consider the dielectric particle response to AC electric fields and analyzes the electrical properties of biological cells. The prototypic 3.2 and 4.8 μm polystyrene particles have fXO values from MyDEP of 425.02 and 275.37 kHz, respectively. Fibroblast cells were also subjected to numerical analysis because the interaction of keratinocytes and fibroblast cells is essential for wound healing. Consequently, the predicted fXO from the MyDEP plot for keratinocyte and fibroblast cells are 510.53 and 28.10 MHz, respectively. The finite element method (FEM) is utilized to compute the electric field intensity and particle trajectory based on DEP and drag forces. Moreover, the particle trajectories are quantified in a high and low conductive medium. To justify the simulation, further DEP experiments are carried out by applying a non-uniform electric field to a mixture of different sizes of polystyrene particles and keratinocyte cells, and these results are well agreed. The alive keratinocyte cells exhibit NDEP force in a highly conductive medium from 100 kHz to 25 MHz. 2D/3D motion analysis software (DIPP-MotionV) can also perform image analysis of keratinocyte cells and evaluate the average speed, acceleration, and trajectory position. The resultant NDEP force can align the keratinocyte cells in the wound site upon suitable applied frequency. Thus, MyDEP estimates the Clausius–Mossotti factors (CMF), FEM computes the cell trajectory, and the experimental results of prototypic polystyrene particles are well correlated and provide an optimistic response towards keratinocyte cells for rapid wound healing applications.
Design and Characterization of Electrochemical Sensor for the Determination of Mercury(II) Ion in Real Samples Based upon a New Schiff Base Derivative as an Ionophore
Authors: Alharthi Salman S. , Fallatah Ahmed M. , Al-Saidi Hamed M.
Published: April 2021

The present paper provides a description of the design, characterization, and use of a Hg2+ selective electrode (Hg2+–SE) for the determination of Hg2+ at ultra-traces levels in a variety of real samples. The ionophore in the proposed electrode is a new Schiff base, namely 4-bromo-2-[(4-methoxyphenylimino)methyl]phenol (BMPMP). All factors affecting electrode response including polymeric membrane composition, concentration of internal solution, pH sample solution, and response time were optimized. The optimum response of our electrode was obtained with the following polymeric membrane composition (% w/w): PVC, 32; o-NPOE, 64.5; BMPMP, 2 and NaTPB, 1.5. The potentiometric response of Hg2+–SE towards Hg2+ ion was linear in the wide range of concentrations (9.33 × 10–8−3.98 × 10–3 molL–1), while, the limit of detection of the proposed electrode was 3.98 × 10–8 molL–1 (8.00 μg L–1). The Hg2+–SE responds quickly to Hg2+ ions as the response time of less than 10 s. On the other hand, the slope value obtained for the developed electrode was 29.74 ± 0.1 mV/decade in the pH range of 2.0−9.0 in good agreement with the Nernstian response (29.50 mV/decade). The Hg2+–SE has relatively less interference with other metal ions. The Hg2+–SE was used as an indicator electrode in potentiometric titrations to estimate Hg2+ ions in waters, compact fluorescent lamp, and dental amalgam alloy and the accuracy of the developed electrode was compared with ICP–OES measurement values. Moreover, the new Schiff base (BMPMP) was synthesized and characterized using ATR–FTIR, elemental analysis, 1H NMR, and 13C NMR. The PVC membranes containing BMPMP as an ionophore unloaded and loaded with Hg(II) are reported by scanning electron microscope images (SEM) along with energy-dispersive X-ray spectroscopy (EDX) spectra.
LBA: Online Learning-Based Assignment of Patients to Medical Professionals
Authors: Rosemarin Hanan , Rosenfeld Ariel , Lapp Steven , Kraus Sarit
Published: April 2021

Central to any medical domain is the challenging patient to medical professional assignment task, aimed at getting the right patient to the right medical professional at the right time. This task is highly complex and involves partially conflicting objectives such as minimizing patient wait-time while providing maximal level of care. To tackle this challenge, medical institutions apply common scheduling heuristics to guide their decisions. These generic heuristics often do not align with the expectations of each specific medical institution. In this article, we propose a novel learning-based online optimization approach we term Learning-Based Assignment (LBA), which provides decision makers with a tailored, data-centered decision support algorithm that facilitates dynamic, institution-specific multi-variate decisions, without altering existing medical workflows. We adapt our generic approach to two medical settings: (1) the assignment of patients to caregivers in an emergency department; and (2) the assignment of medical scans to radiologists. In an extensive empirical evaluation, using real-world data and medical experts’ input from two distinctive medical domains, we show that our proposed approach provides a dynamic, robust and configurable data-driven solution which can significantly improve upon existing medical practices.
Recycling Carbon Tax under Different Energy Efficiency Improvements: A CGE Analysis of China
Authors: Liu Weijiang , Liu Tingting , Li Yangyang , Liu Min
Published: April 2021

Carbon emission reductions and sustainable development have become hot issues in international conferences. As the most direct instrument for carbon emission reductions, the carbon tax has not been favored by policymakers because of its negative effect on the economy. To achieve low-carbon sustainable development, we use a computable general equilibrium (CGE) model to simulate carbon tax recycling under different energy transfer efficiency improvements to achieve triple dividends of carbon emission reductions and social welfare improvement. This paper contributes to the literature on recycling carbon tax for triple dividends in China. The simulation has three main findings: (i) the carbon tax revenue recycling toward reducing the resident income tax rate yields triple dividends without any energy transfer efficiency improvement; (ii) the losses of GDP and social welfare are exaggerated. Meanwhile, the carbon tax brings down carbon emissions and total carbon intensity of GDP with a mild impact on the Chinese economy; (iii) the improvement of energy transfer efficiency demonstrates the advantages of recycling carbon tax and is essential for achieving triple dividends. Thus, we propose the following policy recommendations: (i) the pilot carbon tax mechanism should be launched in high-carbon sectors (such as coal) and then implemented in other industries gradually; (ii) the government should strongly support the technological improvement of energy transfer efficiency in order to achieve sustainable development.
Tourism Economic Network Structural Characteristics of National Parks in the Central Region of China
Authors: Wang Kai , Wang Menghan , Gan Chang , Chen Qinchang , Voda Mihai
Published: April 2021

The social network analysis has been actively applied in various tourist destinations, with a few studies on the tourism economic network structure of national parks. Taking the national parks in the Central Region of China as research objects, this study applies the modified gravity model to measure the strength of tourism economic connection. The social network analysis method (SNA) is used to analyze the network structure of tourism economic connection among national parks from the perspectives of overall network density, network centrality, and cohesive subgroups. The results show that the intensity of the tourism relationships among national parks in Central China is unbalanced in spatial distribution. The structure of tourism economic network presents a multi-core model. Lushan Mountain, Shaoshan, Wudang Mountain, and other national parks play a necessary role in the transmission of regional tourism economic elements. There are cohesive subgroups of connections among national parks, which are closely related to administrative divisions and regional cultural background. The subgroups of interior scenes in the same province are more closely related, and the degree of tourism integration still needs to be improved. The study advances the understanding of tourism economic network relationships among tourist attractions in a destination.
Socio-Emotional Skills as Predictors of Performance of Students: Differences by Gender
Authors: Portela-Pino Iago , Alvariñas-Villaverde Myriam , Pino-Juste Margarita
Published: April 2021

Socio-emotional skills seem to have an important influence on the academic performance of students. This performance is usually higher in girls than in boys. Our aim was to determine which socio-emotional skills influence academic performance and whether gender is a variable that can explain these differences. The results indicated that the socio-emotional skills of adolescents were high, highlighting self-awareness, relationship management, and decision-making. The lowest scores were in social awareness and self-management. Girls obtained higher grades, and students with higher grades had a higher level of social-emotional skills, except in self-management, where there were no differences. Self-management was greater in boys and relationship management was greater in girls. Students who failed did not differ from those who obtained very high results, except in decision-making. Overall, decision-making appeared to be the most important variable in students’ academic performance. Therefore, it would be necessary to design strategies that promote this ability in students. Hence, the adoption of active and collaborative methodologies that facilitate the achievement of this goal is suggested.
Air Pollution Control: An Analysis of China’s Industrial Off-Peak Production Policy through the Quasi-Natural Experiment Method
Authors: Xu Xindi , Wang Qinyun , Hu Haichao , Wang Xinjun
Published: April 2021

To reduce frequent heavy air pollution, the Chinese government suspends clinker production during the heating season in most areas of the North, which is known as the Clinker Off-peak Production Policy. The questions regarding such a repressive production policy for environmental purposes are whether this policy is effective in reducing pollutants and whether the marginal cost is high. To explore these policy effects, a quasi-experiment is designed, taking advantage of spatial-temporal variations in policy implementation. With the triple-difference method and environmental satellite data, the effect on air pollution is estimated to be −1900 μg/m2 (~2%) of SO2 and −3200 μg/m2 (~10%) of NO2. With daily price information and the difference-in-differences method, the market effect is estimated to be an approximately 10% increase in annual sale prices. The marginal cost estimated through a back-of-the-envelope analysis is 32 k RMB yuan/ton SO2 or NO2, which is 24.88 times the pollutant discharge fee but which better reflects the pollutant shadow price.
Inheritance and Development: Study on the Overall Management and Control Strategies of the North–South Extension of Central Axis of Beijing
Authors: Zhang Jing , Shang Yuchen , Li Qiang , Zhang Shiwen , Xiao Jinsong , Li Min
Published: April 2021

The Central Axis of Beijing represents the epitome of this typical feature of ancient Chinese capitals. In 2020, the Beijing government decided to extend it southward and northward, ushering in new opportunities for its protection and development. Based on the “Historical Urban Landscape” analysis framework, the paper constructs an overall analysis framework of the central axis, including its historical evolution, its relationship with Beijing’s macro landscape pattern and its changes, its relationship with urban elements, and the property rights arrangement and public opinion analysis in its governance. Under this analysis framework, the paper expands the overall positioning of the new axis, and on the basis of the integration of historical and cultural heritage, natural ecological factors and urban elements, puts forward the overall control and management strategy system including the control scope, extension direction, horizontal space, axial space, traffic, water system, green space and ecological leisure system, context and governance system.
Spillover Effect of FDI on Food Exports: Based on Firm-Level Analysis in China
Authors: Jin Yue , Chen Chen , Shi Zhanyi
Published: April 2021

This paper examines the spillover effect of foreign direct investment (FDI) on Chinese domestic food exports under firm heterogeneity. By using a rich firm-level panel data of China’s food firms, the empirical analyses rely on the first-order difference generalized method of moments (GMM) for industry-level analysis, and Heckman’s two-stage method for firm-level analysis. The results show that the horizontal FDI led to a positive spillover effect on domestic food industry exports, varying across food subindustries. The paper also finds that a large part of the promotion effect is driven through extensive margin (the probability to export) instead of intensive margin (the quantities of exports) in firm-level analysis. The heterogeneous export spillovers across food firms are further considered to depend on their nature characteristics, like productivity, size, and ownership. Moreover, the heterogeneities of FDI origins and business purpose are confirmed to influence export spillovers. The estimation results are quite robust for different types of regression specifications and substitutions of variable measurement. These findings provide suggestions for decision-makers to carefully assess the impact of FDI and make policy for the sustainable development of domestic food exports.