bluuebunny/crossref_metadata_2025_split huggingface dataset:
Holocene lake phosphorus species and primary producers reflect catchment processes in a small, temperate lake
Authors: Klamt Anna‐Marie , Poulsen Sofie P. , Odgaard Bent V. , Hübener Thomas , McGowan Suzanne , Jensen Henning S. , Reitzel Kasper 
Published: April 2021

AbstractThis paleolimnological study aims to investigate how natural processes and anthropogenic land‐use changes have affected sedimentary phosphorus (P) forms and primary producers in a small, temperate lake (Lake Fuglsø, Denmark) throughout the Holocene. Our multi‐proxy approach uses pollen, X‐ray fluorescence scanning, carbon (C) and nitrogen contents and stable isotopes, sequential P extraction, 31P nuclear magnetic resonance spectroscopy, pigments, diatoms, and plant macrofossils from a 14C‐dated sediment record. We found three periods of human impact: (1) low disturbance from domestic grazing during the early/mid Neolithic (~3600 to ~2600 BC), (2) higher disturbance because of animal husbandry and some grain cultivation during the Late Bronze and Pre‐Roman Iron Age (~800 BC to AD ~100), and (3) strong disturbance caused by domestic grazing, intensified crop cultivation and, in particular, by retting of fiber plants during the Middle Ages and Renaissance (AD ~1000 to ~1700). Cultural eutrophication during the latter phase caused unprecedented changes in the lake, including altered species composition, high production, and strongly accelerated sediment accumulation rates. Generally, catchment deforestation was related to elevated proportions of metal (iron, aluminum, calcium)‐bound P forms in the sediment, while high tree cover correlated with elevated proportions of P forms associated with organic material (“organic” P, humic‐bound P, refractory organic P) and loosely bound P. During phases with forest in the catchment, silicon (Si) inputs to the lake were insufficient and diatom frustules were mostly absent in the sediments. In contrast, diatoms thrived in the lake when the landscape was open and erosional Si influx was high. This study is the first to show long‐term (~eight millennia) and recurring Si limitation of diatoms, a finding that may explain the absence of diatoms in sediment records of other sites too. In summary, human land‐use with preceding deforestation accelerated the transport of nutrients and elements from the terrestrial to the aquatic environment, leading to substantial and irreversible changes in Lake Fuglsø. Our study is a good example of the tight links between catchment processes and lake status, indicating that catchment dynamics should be considered in lake restoration projects, particularly for lowland lakes with high catchment : lake area ratios.
Precise Color Communication by Determination of the Color of Vegetable Oils and Fats in the CIELAB 1976 (L*a*b*) Color Space
Authors: Brühl Ludger , Unbehend Günter 
Published: April 2021

AbstractThe precise determination of the colour of oils and fats is a common and important parameter for the production of oils, fats, margarine, and mayonnaise. A new method has been developed and tested in order to improve reliability and reproducibility of the results. It is based on colour values, which describe the colour in a 3D space as defined by the International Commission on Illumination (CIE) as CIE 1976 (L*a*b*). The precision data obtained from a collaborative method validation test show significant improved repeatability with relative coefficients of variation of repeatability between 0.1 and 1.7% except for a very dark pumpkin seed oil (2.7%). The coefficients of variation of reproducibility range from 0.7 to 13.9 %. The signals of very intense colored samples might exceed the linear range of some measuring instruments. Solutions of colour standards tartrazine and Ponceau 4R as pure (>99 %) and non‐toxic substances are tested for laboratory calibration covering a colour space from CIE 1976 L* (63–99), a* (−23–67), and b* (0.5–119). A storage experiment with these standard substances is carried out and the results show improved stability over a period of 80 days compared to bromothymol blue and iodine standard solutions.Practical Applications: The results of this study show the suitability of an analysis method for the determination of the colour of oils and fats using the 3D CIE 1976 colour space as an alternative to the common Lovibond system of red and yellow colour values. As the international harmonized approach of the CIE 1976 colour space is widely accepted for the communication of precise colour description and differences between two different colors in many applications all over the world, this will be also an advantage for the communication and specification of colors in the oils and fats industry, market, and trade. In addition, the use of easy to prepare colour standard solutions enables every laboratory to check the suitability of their colour measuring device in a convenient way.
Effect of Interfacial Activity of Eugenol and Eugenol Esters with Different Alkyl Chain Lengths on Inhibiting Sunflower Oil Oxidation
Authors: Keramat Malihe , Golmakani Mohammad‐Taghi , Toorani Mohamad Reza 
Published: April 2021

AbstractEffects of eugenol esters with different alkyl chain lengths and combinations of eugenol + eugenol esters on sunflower oil oxidation at 338, 358, and 378 K are evaluated by determining different kinetic parameters. Also, water content and reverse micelles size of sunflower oil samples are monitored during oxidation. Eugenyl acetate shows higher antioxidant activity than eugenol in sunflower oil, while eugenyl butyrate, eugenyl hexanoate, and eugenyl decanoate shows lower antioxidant activity than eugenol. Antioxidant activity of eugenol esters decreases by increasing their alkyl chain length. Eugenol shows a synergistic effect with eugenyl acetate and eugenyl butyrate on increasing the induction period and antioxidant activity values, while it shows an antagonistic effect with eugenyl hexanoate and eugenyl decanoate. Also, combinations of eugenol + eugenyl acetate, as well as, eugenol + eugenyl butyrate stabilize the reverse micelles at longer period of time (3263 min for eugenol + eugenyl acetate and 2900 min for eugenol + eugenyl butyrate) than eugenol (2750 min). In addition, eugenol + eugenyl acetate and eugenol + eugenyl butyrate decrease the magnitude of temperature‐related effects on sunflower oil oxidation to the higher extent than eugenol did.Practical applications: Recent studies have suggested that the antioxidants with ability to locate at the active sites of lipid oxidation can efficiently reduce lipid oxidation in bulk oil. Despite a remarkable focus on antioxidant activity of eugenol, there is no information regarding improving its interfacial performance through esterification method. Also, there are few published data regarding the effects of esterified antioxidants on physicochemical changes during the oxidation of bulk oil. In this study, eugenol is esterified with anhydrides with different alkyl chain lengths to increase its accessibility to the active site of lipid oxidation, that is, water–oil interface of reverse micelles in sunflower oil. Effects of eugenol esters on stability of reverse micelles and critical reverse micelles concentration of lipid hydroperoxides have been investigated for the first time.
Maximization of heat transfer density from a single‐row cross‐flow heat exchanger with wing‐shaped tubes using constructal design
Authors: Anas Rusul Qusay , Mussa Munther Abdullah 
Published: April 2021

AbstractA single‐row cross‐flow heat exchanger with wing‐shaped tubes is designed in this paper using the constructal design method. The wing‐to‐wing spacing and the wing thickness are free to morph while the chord of the wings remains constant. Wing‐to‐wing spacing optimization or heat transfer density maximization from the wings is the objective function in this design. Two directions of the free‐stream (incoming) flow are considered. The right‐ and left‐flow directions are considered with a constant drop in pressure. All wings are heated at a uniform temperature, and the air is used to cool these wings. The two‐dimensional conservation of mass, conservation of momentum, and the conservation of energy equations are solved by means of the finite volume method for steady and incompressible flow. The ratio of the wing thickness to the chord (dimensionless wing thickness) is changed from 0.2 to 1. For each wing thickness, three Bejan numbers (Be = 103, 104, and 105) are used in the numerical simulation. The results revealed that in the case of the flow direction to the left, the maximum heat transfer density is higher than that in the case of the flow direction to the right for all wing thicknesses and all Bejan numbers.
In vitro evaluation of loaded chitosan membranes for pain relief and infection prevention
Authors: Harrison Zoe L. , Bumgardner Joel D. , Fujiwara Tomoko , Baker Daniel L. , Jennings J. Amber 
Published: April 2021

AbstractWounds resulting from surgeries, implantation of medical devices, and musculoskeletal trauma result in pain and can also result in infection of damaged tissue. Up to 80% of these infections are due to biofilm formation either on the surface of implanted devices or on surrounding wounded tissue. Bacteria within a biofilm have intrinsic growth and development characteristics that allow them to withstand up to 1,000 times the minimum inhibitory concentration of antibiotics, demonstrating the need for new therapeutics to prevent and treat these infections. Cis‐2‐decenoic acid (C2DA) is known to disperse preformed biofilms and can prevent biofilm formation entirely for some strains of bacteria. Additionally, local anesthetics like bupivacaine have been shown to have antimicrobial effects against multiple bacterial strains. This study sought to evaluate hexanoic acid‐treated electrospun chitosan membranes (HA‐ESCM) as wound dressings that release C2DA and bupivacaine to simultaneously prevent infection and alleviate pain associated with musculoskeletal trauma. Release profiles of both therapeutics were evaluated, and membranes were tested in vitro against Methicillin‐resistant Staphylococcus aureus (MRSA) to determine efficacy in preventing biofilm infection and bacterial growth. Results indicate that membranes release both therapeutics for 72 hr, and release profile can be tailored by loading concentration. Membranes were effective in preventing biofilm growth but were toxic to fibroblasts when loaded with 2.5 or 5 mg of bupivacaine.
Patellofemoral and tibiofemoral joint loading during a single‐leg forward hop following ACL reconstruction
Authors: Sritharan Prasanna , Schache Anthony G. , Culvenor Adam G. , Perraton Luke G. , Bryant Adam L. , Morris Hayden G. , Whitehead Timothy S. , Crossley Kay M. 
Published: April 2021

AbstractAltered biomechanics are frequently observed following anterior cruciate ligament reconstruction (ACLR). Yet, little is known about knee‐joint loading, particularly in the patellofemoral‐joint, despite patellofemoral‐joint osteoarthritis commonly occurring post‐ACLR. This study compared knee‐joint reaction forces and impulses during the landing phase of a single‐leg forward hop in the reconstructed knee of people 12‐24 months post‐ACLR and uninjured controls. Experimental marker data and ground forces for 66 participants with ACLR (28 ± 6 years, 78 ± 15 kg) and 33 uninjured controls (26 ± 5 years, 70 ± 12 kg) were input into scaled‐generic musculoskeletal models to calculate joint angles, joint moments, muscle forces, and the knee‐joint reaction forces and impulses. The ACLR group exhibited a lower peak knee flexion angle (mean difference: −6°; 95% confidence interval: [−10°, −2°]), internal knee extension moment (−3.63 [−5.29, −1.97] percentage of body weight × participant height (body weight [BW] × HT), external knee adduction moment (‐1.36 [−2.16, −0.56]% BW × HT) and quadriceps force (−2.02 [−2.95, −1.09] BW). The ACLR group also exhibited a lower peak patellofemoral‐joint compressive force (−2.24 [−3.31, −1.18] BW), net tibiofemoral‐joint compressive force (−0.74 [−1.20, 0.28] BW), and medial compartment force (−0.76 [−1.08, −0.44] BW). Finally, only the impulse of the patellofemoral‐joint compressive force was lower in the ACLR group (−0.13 [−0.23, −0.03] body weight‐seconds). Lower compressive forces are evident in the patellofemoral‐ and tibiofemoral‐joints of ACLR knees compared to uninjured controls during a single‐leg forward hop‐landing task. Our findings may have implications for understanding the contributing factors for incidence and progression of knee osteoarthritis after ACLR surgery.
AuNPs Decorated PLA Stereocomplex Micelles for Synergetic Photothermal and Chemotherapy
Authors: Fan Xiaoshan , Luo Zheng , Ye Enyi , You Mingliang , Liu Minting , Yun Ye , Loh Xian Jun , Wu Yun‐Long , Li Zibiao 
Published: April 2021

AbstractA unique platform for combined photothermal and chemotherapy using PLA stereocomplex (PLA SC) micelles‐induced hybrid gold nanocarriers is designed. The PLA SC micelles, made from the self‐assembly of poly(ethylene glycol)‐block‐poly(l‐lactide) (PEG‐PLLA) and poly(2‐(dimethylamino) ethyl methacrylate)‐block‐poly(d‐lactide) (PDMAEMA‐PDLA), for the first time are used as a template to fabricate the hybrid PLA SC@Au core–shell nanocarriers, in which the anticancer drugs are encapsulated within the core, while the Au nanoparticles are tethered in the shell via the in situ reduction of AuCl4− by PDMAEMA. The obtained PLA SC@Au hybrid nanocarriers exhibit low toxicity and remarkable photothermal effect. Upon near‐infrared laser irradiation, the on‐site photothermal therapy can further induce an accelerated drug release from the hybrid nanocarrier reservoir via hyperthermia heating of the nanocarriers, thus leading to a synergistic photothermal and chemotherapy toward a significantly improved efficacy in tumor shrinkage. The as‐designed PLA SC@Au hybrid nanocarriers, with their biocompatible compositions, dual‐drug delivery characteristics, and combined photothermal/chemotherapy, show high potential as a novel platform for cancer treatment.
Fabrication of Biodegradable Polyurethane Foam Scaffolds with Customized Shapes and Controlled Mechanical Properties by Gas Foaming Technique
Authors: Han Soo Kyung , Song Minju , Choi Kangho , Choi Sung‐Wook 
Published: April 2021

AbstractPoly(ε‐caprolactone) (PCL)‐based polyurethane (PU) foam scaffolds with different mechanical properties are fabricated using a gas foaming technique to use as porous substitutes for ear or bone with cartilage. PCL diol or triol is used as a polyol in PU foam for biocompatibility and biodegradation, with an aqueous gelatin solution as a blowing agent. The highly porous inner and outer structures of the scaffolds are developed by employing a silicone surfactant and sulfuric acid, respectively. The PU scaffolds prepared by PCL diol show ductile and flexible properties, whereas the PU scaffolds prepared by PCL triol exhibit high compression strength. In vitro test reveals the low toxicity of the PU scaffolds and the high ALP activity of MC3T3‐E1 cells in the PU scaffold prepared by PCL triol. By taking advantage of the difference in mechanical properties, customized PU scaffolds with ear or bone shapes are fabricated using a silicone mold. The PU scaffolds with two compartments of PCL diol and triol (corresponding to cartilage and bone, respectively) are fabricated as a substitute for bone with cartilage. It is believed that the PU scaffolds with highly porous structure and controlled mechanical properties have wide potential application for tissue engineering.
Shape‐free arbitrary polygonal hybrid stress/displacement‐function flat shell element for linear and geometrically nonlinear analyses
Authors: Wu Cheng‐jin , Cen Song , Ma Ru‐xia , Li Chen‐feng 
Published: April 2021

AbstractA high‐performance shape‐free arbitrary polygonal hybrid stress/displacement‐function flat shell finite element method is proposed for linear and geometrically nonlinear analyses of shells. First, an arbitrary polygonal Mindlin–Reissner plate element and an arbitrary polygonal membrane element with drilling degrees of freedom are constructed based on hybrid displacement‐function and hybrid stress‐function methods, respectively. Both elements have only two corner nodes along each edge. Second, by assembling the plate and the membrane elements, an arbitrary polygonal flat shell element is constructed. Third, based on the corotational method, a proper best‐fit corotated frame for geometrically nonlinear polygonal elements is designed. By updating the analytical trial functions of shell element in each increment step, the original linear flat shell element is generalized to a geometrically nonlinear model. Numerical examples show that the new element possesses excellent performance for both linear and geometrically nonlinear analyses, and possesses outstanding flexibility in dealing with complex loading distributions and mesh shapes.
Magnetohydrodnamics nanofluid flow of shaped nanoparticles over a porous stretching wall and slip effect
Authors: Rashid Irfan , Sagheer Muhammad , Hussain Shafqat 
Published: April 2021

AbstractIn this study, we analyze the magnetohydrodynamic flow of magnetite‐engine oil nanofluid in the presence of nonidentical shaped nanoparticles subject to the porous medium and velocity slip effect. Energy analysis is carried out with the Ohmic heating and thermal radiation impacts. The system of partial differential equations are transformed into the system of ordinary differential equations using similarity variable. The Hamilton–Crosser model is used. The exact solutions for the momentum and heat transport analysis are found. The impact of various emerging parameters on the velocity and temperature profiles are analyzed by graphs. Furthermore, the local skin friction and heat transfer rate are examined graphically. It is examined that the velocity field increases with an increment in the magnitude of ϕ and L. An increase in the value of Hartman number enhancing the temperature profile.
Feasibility studies of intraocular use of gelatin methacryloyl hydrogel to patch retinal tears
Authors: Chen Juan , Wang Chunyi , Wen Wen , Ni Jie , Jiang Jingjie , Ge Zhongjun , Wang Mingwei , Zhang Fang 
Published: April 2021

AbsractWe engineered gelatin methacryloyl (GelMA) to be a sealant that can patch retinal tears and verified its biocompatibility in rabbit eyes. We compared adhesion, stability at 37°C, degradation time, swelling ratio, photo‐crosslinking time, pH, and physical conditions before photo‐crosslinking GelMA at 37°C with different methacrylic anhydride (MA) degrees of substitution (25, 50, and 75%) and concentrations (10, 20, and 30%). We injected 0.1 ml GelMA prepolymer into the vitreous cavity in study rabbits (n = 6) and 0.1 ml normal saline into control rabbits (n = 6), and performed clinical and histological examinations. GelMA hydrogel with a 75% degree of substitution and 20% concentration (75/20) exhibited stronger adhesion and stable properties during the first 2 weeks. It can be injected with a 25‐gauge needle at 37°C before photo‐crosslinking. Degradation time was acceptable, the swelling ratio was low, photo‐crosslinking time was short, and the pH was stable. No significant inflammation or other complications occurred, and intraocular pressure remained within a normal range of 16–20 mmHg after surgery. Histological examination revealed no damage to the retinal layers. GelMA (75/20) was the most suitable formulation to close retinal tears, and it exhibited satisfactory intraocular biocompatibility. GelMA can be used as a patch to seal retinal tears during vitrectomy for rhegmatogenous retinal detachment.
Downregulation of 5‐hydroxymethylcytosine is an early event in pancreatic tumorigenesis
Authors: Fujikura Kohei , Alruwaii Zainab I , Haffner Michael C , Trujillo Maria A , Roberts Nicholas J , Hong Seung‐Mo , Macgregor‐Das Anne , Goggins Michael G , Roy Sujayita , Meeker Alan K , Ding Ding , Wright Michael , He Jin , Hruban Ralph H , Wood Laura D 
Published: April 2021

AbstractEpigenetic alterations are increasingly recognized as important contributors to the development and progression of pancreatic ductal adenocarcinoma. 5‐hydroxymethylcytosine (5hmC) is an epigenetic DNA mark generated through the ten‐eleven translocation (TET) enzyme‐mediated pathway and is closely linked to gene activation. However, the timing of alterations in epigenetic regulation in the progression of pancreatic neoplasia is not well understood. In this study, we hypothesized that aberrant expression of ten‐eleven translocation methylcytosine dioxygenase 1 (TET1) and subsequent global 5hmC alteration are linked to early tumorigenesis in the pancreas. Therefore, we evaluated alterations of 5hmC and TET1 levels using immunohistochemistry in pancreatic neoplasms (n = 380) and normal ducts (n = 118). The study cohort included representation of the full spectrum of precancerous lesions from low‐ and high‐grade pancreatic intraepithelial neoplasia (n = 95), intraductal papillary mucinous neoplasms (all subtypes, n = 129), intraductal oncocytic papillary neoplasms (n = 12), and mucinous cystic neoplasms (n = 144). 5hmC and TET1 were significantly downregulated in all types of precancerous lesion and associated invasive pancreatic ductal adenocarcinomas compared with normal ductal epithelium (all p < 0.001), and expression of 5hmC positively correlated with expression of TET1. Importantly, downregulation of both 5hmC and TET1 was observed in most low‐grade precancerous lesions. There were no clear associations between 5hmC levels and clinicopathological factors, thereby suggesting a common epigenetic abnormality across precancerous lesions. We conclude that downregulation of 5hmC and TET1 is an early event in pancreatic tumorigenesis. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Modeling and simulation of the elastic properties of natural fiber‐reinforced thermosets
Authors: Alhijazi Mohamad , Safaei Babak , Zeeshan Qasim , Asmael Mohammed 
Published: April 2021

AbstractThis paper presents an analysis on the elastic characteristics of luffa and palm natural fiber composites (NFC) with epoxy and ecopoxy matrixes, taking into account the impact of fiber volume fractions. Furthermore, longitudinal modulus, transverse modulus, shear modulus, and Poisson's ratio were predicted using representative volume elements (RVEs) with chopped random and unidirectional fiber arrangements. However, analytical approaches such as rule of mixture, Chamis, Halpin–Tsai, and Nielsen were considered for validating and comparing the findings of finite element analyses. Hence, it was found that increasing fiber volume fraction increased the elastic properties of palm/epoxy, palm/ecopoxy, and luffa/epoxy NFCs, but decreased that of luffa/ecopoxy NFC. Addition of palm fibers in ecopoxy and epoxy had stronger effect than luffa on enhancing the elastic properties of the final structure. However, greatest elastic characteristics observed through analytical and numerical models were obtained for ecopoxy matrix with 0.5 palm fibers. A strong agreement was observed between the results obtained from analytical approaches and RVE unidirectional model. Chamis model exhibited higher outcomes compared to the considered analytical techniques, while Halpin–Tsai model showed the least values.