bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detailed positron annihilation lifetime spectroscopic investigation of atrazine imprinted polymers grafted onto PE/PP non‐woven fabrics
Authors: Söylemez Meshude Akbulut , Güven Olgun 
Published: October 2017

AbstractThis study presents the preparation of molecularly imprinted matrices by using radiation‐induced grafting technique onto polyethylene/polypropylene (PE/PP) non‐woven fabrics. Atrazine imprinted polymers were grafted onto PE/PP non‐woven fabrics through the use of methacrylic acid (MAA) and ethylene glycol dimethylacrylate (EGDMA) as the functional monomer and crosslinking agent, respectively. Grafted MIPs were characterized by attenuated total reflectance Fourier transform infra‐red spectroscopy (ATR‐FTIR), X‐ray photoelectron spectroscopy (XPS), elemental analysis, scanning electron microscopy (SEM), and positron annihilation lifetime spectroscopy (PALS). The average diameter of free volume holes was determined as 0.612 nm which correlates very well with the size of template molecule atrazine, 0.512 nm. Binding behaviors were investigated against various factors, such as concentration of template molecule, pH, and contact time. Furthermore, the specific selectivity of grafted MIP on non‐woven fabric was studied by using other common triazine compounds, such as simazine and metribuzine which show structural similarities to atrazine. The specific binding values for atrazine, simazine, and metribuzine were determined as 40%, 2.5%, and 1.5%, respectively.
Emerging materials for sample preparation
Authors: Maya Fernando , Palomino Cabello Carlos , Ghani Milad , Turnes Palomino Gemma , Cerdà Víctor 
Published: October 2017

AbstractThis review provides an update on the implementation of emerging materials as sorbents for sample preparation in combination with chromatographic separation. We have focused on recent applications of metal–organic frameworks, layered double hydroxides, porous carbons obtained from polymers or biomass precursors, and silicates (clays and zeolites). The review is directed toward the strategies followed by the authors to engineer suitable supports enabling the application of materials with unconventional size and shape as high‐performance sorbents to explore new boundaries in sample pretreatment in manual or automated modes.
A review of methods for the chemical characterization of cannabis natural products
Authors: Leghissa Allegra , Hildenbrand Zacariah L. , Schug Kevin A. 
Published: October 2017

AbstractCannabis has garnered a great deal of new attention in the past couple of years in the United States due to the increasing instances of its legalization for recreational use and indications for medicinal benefit. Despite a growing number of laboratories focused on cannabis analysis, the separation science literature pertaining to the determination of cannabis natural products is still in its infancy despite the plant having been utilized by humans for nearly 30 000 years and it being now the most widely used drug worldwide. This is largely attributable to the restrictions associated with cannabis as it is characterized as a schedule 1 drug in the United States. Presented here are reviewed analytical methods for the determination of cannabinoids (primarily) and terpenes (secondarily), the primary natural products of interest in cannabis plants. Focus is placed foremost on analyses from plant extracts and the various instrumentation and techniques that are used, but some coverage is also given to analysis of cannabinoid metabolites found in biological fluids. The goal of this work is to provide a collection of relevant separation science information, upon which the field of cannabis analysis can continue to grow.
Microvasculature dropout detected by the optical coherence tomography angiography in nonarteritic anterior ischemic optic neuropathy
Authors: Song Yi , Min Jing‐yu , Mao Lei , Gong Yuan‐yuan 
Published: October 2017

ObjectiveTo investigate microcirculation characteristics of peripapillary superficial retina and optic disc in eyes with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA).MethodsForty‐one eyes of 30 NAION patients and 30 eyes of 30 normal subjects were evaluated with OCTA (AngioVue, Optovue). The whole vessel density, inside disc vessel density, peripapillary vessel density, and vessel densities based on the sectorial division in the nerve head mode peripapillary superficial retina and RPC mode optic disc were measured respectively.ResultsIn the NAION group, vessel densities in both the peripapillary superficial retina and optic disc were significant reduced (P < 0.01), as compared with the control group. The whole vessel density of the optic disc in chronic NAION group were significantly lower than that in acute NAION group (P < 0.01). The whole and temporal vessel density of the peripapillary superficial retina was significantly correlated with log MAR VA (r = −0.381 and r = −0.337, both P < 0.05). Vessel densities in both the peripapillary superficial retina and optic disc were reduced (P < 0.05) in unilateral involved eyes, as compared to the unaffected fellow eyes, except for the inside disc (P = 0.270) and SN (P = 0.054) vessel density in the optic disc, while there was no difference in the fellow eyes compared to the normal eyes.ConclusionIn NAION patients, a dropout of microvasculature in peripapillary superficial retina and optic disc could be detected by OCTA directly. OCTA might become a useful tool for detection and monitoring of NAION. Lasers Surg. Med. 50:194–201, 2018. © 2017 Wiley Periodicals, Inc.
Microstructure and properties of in‐situ vanadium carbide phase reinforced nickel based coating by laser cladding
Authors: Hai‐Qiang Cheng , Han‐Guang Fu , Kai‐Ming Wang , Xiao‐Le Cheng , Yin‐Hu Qu , Yong‐Ping Lei , Da‐Wei Yi 
Published: October 2017

AbstractLaser cladding has been applied to fabricate in‐situ vanadium carbide phase on the surface of C45E (according to ISO 683‐1:2016 (E)) using a preplaced powder consisting of 55 wt.% Ni35 and 45 wt.% (FeV50 + graphite), meanwhile, pure Ni35 has also been cladded for comparison. The microstructure and phases analysis were carried out by means of optical microscope, X‐ray diffractometer, scanning electron microscope, energy dispersive spectroscopy, and electron probe microanalysis. The microhardness and wear resistance were tested through the microhardness tester and ring‐on‐block wear tester respectively. The results show that there are many kinds of microstructure such as cellular and columnar crystals for the pure Ni35 cladding coating, and lots of cellular or dendritic vanadium carbide and reticular Cr2Fe14C3 phases distribute over the Fe3Ni2 matrix in the coating cladded with 55 wt.% Ni35 and 45 wt.% (FeV50 + graphite). Vanadium carbide phase is uniformly distributed and bonded metallurgically to the matrix very well, which increases the hardness and wear resistance. The wear resistance of coating cladded with 55 wt. % Ni35 and 45 wt. % (FeV50 + graphite) alloy powder is 5.16 times as high as C45E, and is higher 139.7% than that of the pure Ni35 clad layer.
The spreaded gracilis flap revisited: Comparing outcomes in lower limb reconstruction
Authors: Heidekrueger Paul Immanuel , Ehrl Denis , Ninkovic Milomir , Thiha Aung , Prantl Lukas , Herter Frank , Mueller Camillo , Broer Peter Niclas 
Published: October 2017

BackgroundIn lower limb reconstruction, the free gracilis muscle flap is usually chosen for coverage of small‐ to medium‐sized defects. Aim of this study was a re‐appraisal regarding the reconstructive indications of the gracilis muscle flap with a focus on postoperative complications in order to evaluate if it can also be routinely used to reconstruct large‐size lower limb defects.MethodsA total of 204 patients underwent free gracilis muscle transfers for lower limb reconstruction at our institution. Cases were divided according to the size of the defect into two groups (<150 cm2 versus ≥150 cm2). The small‐ to medium defect size group included 150 patients and the large defect size group included 54 patients. In the large defect size group, the muscle was enlarged as needed by careful dissection of the epimysium and all connective tissue surrounding the intrinsic vessels under loupe magnification to protect the muscle perfusion. Surgical complications were accounted for and the two groups compared accordingly.ResultsOverall, there were no significant differences between the two groups of patients regarding the rate of major (15.72% versus 10.91%; P = .506) and minor surgical complications (6.92% versus 3.64%; P = .522). The total percentage of flap losses in the small to medium defect size group was 5.03%. There were no total flap losses in the large defect size group (P = .117).ConclusionThe use of the spreaded gracilis flap provides a valuable option for the microsurgeon, especially also to reconstruct large size lower limb defects.
Reconstruction of severe atherosclerotic and obstructive diabetic feet using thoracodorsal artery perforator flaps with long vascular pedicles
Authors: Kim Sang Wha , Sung Il Hoon , Kim Youn Hwan 
Published: October 2017

BackgroundFoot ulcers in diabetic patients often require free flaps. A long vascular pedicle is mandatory so that more proximal vessels can be used as recipient vessels, especially when the flap is used to reconstruct distal foot defects. We evaluated the outcome of diabetic foot defect that were reconstructed using thoracodorsal artery perforator (TDAP) flaps with long vascular pedicles.Patients and MethodsWe reconstructed the foot defects of 22 diabetic patients. Nineteen patients were male, and the mean age was 56.4 years. The defects were located in big toe in 11 patients; fourth and/or fifth toe, including lateral aspect of the foot, in 8 patients; and dorsum of the foot, medial plantar, and first metatarsal medial head in 1 patient each. CT angiography showed that the two main vessels of the lower leg remained intact in 7 patients, only one vessel was intact in the lower leg of 11, and no vessels were visible in 4.ResultsThe flap size ranged between 5 × 4 cm2 and 18 × 11cm2, with a mean pedicle length of 16.5 cm. The anterior tibial artery was used as the recipient vessel in 15 patients, while the posterior tibial artery was used in 7. All the flaps survived. Three wound disruptions and two partial flap losses healed conservatively, without further surgery. Ulcer due to diabetes recurred in three cases. The mean follow‐up period was 46.1 months. All wounds healed completely.ConclusionsTDAP flaps with long vascular pedicles may be a viable choice for reconstructing defects in the feet of diabetic patients.
Liquid tissue surrogates for X‐ray and CT phantom studies
Authors: FitzGerald Paul F. , Colborn Robert E. , Edic Peter M. , Lambert Jack W. , Bonitatibus Peter J. , Yeh Benjamin M. 
Published: October 2017

PurposeTo develop a simple method for producing liquid‐tissue‐surrogate (LTS) materials that accurately represent human soft tissues in terms of density and X‐ray attenuation coefficient.Methods and materialsWe evaluated hypothetical mixtures of water, glycerol, butanol, methanol, sodium chloride, and potassium nitrate; these mixtures were intended to emulate human adipose, blood, brain, kidney, liver, muscle, pancreas, and skin. We compared the hypothetical densities, effective atomic numbers (Zeff), and calculated discrete‐energy CT attenuation [Hounsfield Units (HU)] of the proposed materials with those of human tissue elemental composition as specified in International Commission on Radiation Units (ICRU) Report 46. We then physically produced the proposed LTS materials for adipose, liver, and pancreas tissue, and we measured the polyenergetic CT attenuation (also expressed as HU) of these materials within a 32 cm phantom using a 64‐slice clinical CT scanner at 80 kVp, 100 kVp, 120 kVp, and 140 kVp.ResultsThe predicted densities, Zeff, and calculated discrete‐energy CT attenuation of our proposed formulations generally agreed with those of ICRU within < 1% or < 10 HU. For example, the densities of our hypothetical materials agreed precisely with ICRU's reported values and were 0.95 g/mL for adipose tissue, 1.04 g/mL for pancreatic tissue, and 1.06 g/mL for liver tissue; the discrete‐energy CT attenuation at 60 keV of our hypothetical materials (and ICRU‐specified compositions) were −107 HU (−113 HU) for adipose #3, −89 HU (−90 HU) for adipose #2, 56 HU (55 HU) for liver tissue, and 31 HU (31 HU) for pancreatic tissue. The densities of our physically produced materials (compared to ICRU‐specified compositions) were 0.947 g/mL (0.0%) for adipose #2, 1.061 g/mL (+2.0%) for pancreatic tissue, and 1.074 g/mL (+1.3%) for liver tissue. The empirical polyenergetic CT attenuation measurements of our LTS materials (and the discrete‐energy HU of the ICRU compositions at the mean energy of each spectrum) at 80 kVp were −104 HU (−113 HU) for adipose #3, −87 HU (−90 HU) for adipose #2, 59 HU (55 HU) for liver tissue, and 33 HU (31 HU) for pancreatic tissue; at 120 kVp, these were −83 HU (−83 HU) for adipose #3, −68 HU (−63 HU) for adipose #2, 55 HU (52 HU) for liver tissue, and 35 HU (33 HU) for pancreatic tissue.ConclusionOur method for formulating tissue surrogates allowed straightforward production of solutions with CT attenuation that closely matched the target tissues' expected CT attenuation values and trends with kVp. The LTSs' inexpensive and widely available constituent chemicals, combined with their liquid state, should enable rapid production and versatile use among different phantom and experiment types. Further study is warranted, such as the inclusion of contrast agents. These liquid tissue surrogates may potentially accelerate development and testing of advanced CT imaging techniques and technologies.
Optimization of data acquisition in axial CT under the framework of sampling on lattice for suppression of aliasing artifacts with algorithmic detector interlacing
Authors: Xie Huiqiao , Tang Xiangyang 
Published: October 2017

PurposeWe present the methodology for analyzing and optimizing the sampling structure of projection data acquisition in axial multidetector CT (MDCT) and cone beam CT (CBCT) under the framework of sampling on lattice. Specifically, we propose and evaluate the scheme of interlaced detector cell binning for suppression of longitudinal aliasing artifacts. In addition, we investigate the proposed scheme's capability of mitigating shift variation in spatial resolution and possibility of improving CB image reconstruction accuracy.MethodsUnder the framework of sampling on lattice, the proposed scheme is evaluated using an axial MDCT with its architecture similar to that of state‐of‐the‐art CT scanners for diagnostic imaging in the clinic. The widely used FDK algorithm is adopted for image reconstruction, in which either horizontal/latitudinal or vertical/longitudinal interpolation is used for lining‐up of projection data between interlaced detector cells. Using a spiral clock phantom, the capability of suppressing aliasing artifacts and possibility of improving reconstruction accuracy is quantitatively investigated. The in‐plane spatial resolution, as assessed by the modulation transfer function (MTF), and its shift‐variant property are quantitatively assessed using wire phantoms, while the through‐plane spatial resolution and its shift‐variant behavior are assessed by the slice sensitivity profile (SSP) using thin foil phantoms.ResultsThe preliminary results show that the interlaced detector cell binning can suppress longitudinal aliasing artifacts effectively, while the shift variation in spatial resolution and reconstruction inaccuracy can be mitigated moderately. In addition, the direction, along which the interpolation is carried out to line up projection data between the interlaced detector cells for image reconstruction, plays a significant role in determining the in‐plane and through‐plane spatial resolution.ConclusionsThe scheme of interlaced detector cell binning with longitudinal interpolation for data lining‐up is an effective solution for suppression of longitudinal aliasing artifacts in axial MDCT and CBCT.
Isogeometric FEM‐BEM coupled structural‐acoustic analysis of shells using subdivision surfaces
Authors: Liu Zhaowei , Majeed Musabbir , Cirak Fehmi , N. Simpson Robert 
Published: October 2017

SummaryWe introduce a coupled finite and boundary element formulation for acoustic scattering analysis over thin‐shell structures. A triangular Loop subdivision surface discretisation is used for both geometry and analysis fields. The Kirchhoff‐Love shell equation is discretised with the finite element method and the Helmholtz equation for the acoustic field with the boundary element method. The use of the boundary element formulation allows the elegant handling of infinite domains and precludes the need for volumetric meshing. In the present work, the subdivision control meshes for the shell displacements and the acoustic pressures have the same resolution. The corresponding smooth subdivision basis functions have the C1 continuity property required for the Kirchhoff‐Love formulation and are highly efficient for the acoustic field computations. We verify the proposed isogeometric formulation through a closed‐form solution of acoustic scattering over a thin‐shell sphere. Furthermore, we demonstrate the ability of the proposed approach to handle complex geometries with arbitrary topology that provides an integrated isogeometric design and analysis workflow for coupled structural‐acoustic analysis of shells.
The bulky and the sweet: How neutralizing antibodies and glycan receptors compete for virus binding
Authors: Dietrich Melanie H. , Harprecht Christina , Stehle Thilo 
Published: October 2017

AbstractNumerous viruses rely on glycan receptor binding as the initial step in host cell infection. Engagement of specific glycan receptors such as sialylated carbohydrates, glycosaminoglycans, or histo‐blood group antigens can determine host range, tissue tropism, and pathogenicity. Glycan receptor‐binding sites are typically located in exposed regions on viral surfaces—sites that are also generally prone to binding of neutralizing antibodies that directly interfere with virus‐glycan receptor interactions. In this review, we examine the locations and architecture of the glycan‐ and antibody‐binding sites in four different viruses with stalk‐like attachment proteins (reovirus, influenza virus, norovirus, and coronavirus) and investigate the mechanisms by which antibodies block glycan recognition. Those viruses exemplify that direct molecular mimicking of glycan receptors by antibodies is rare and further demonstrate that antibodies often partly overlap or bind sufficiently close to the receptor‐binding region to hinder access to this site, achieving neutralization partially because of the epitope location and partly due to their sheer size.
Spatial features of proteins related to their phosphorylation and associated structural changes
Authors: Karasev Dmitry A. , Veselova Darya A. , Veselovsky Alexander V. , Sobolev Boris N. , Zgoda Victor G. , Archakov Alexander I. 
Published: October 2017

AbstractProtein phosphorylation is widely used in biological regulatory processes. The study of spatial features related to phosphorylation sites is necessary to increase the efficacy of recognition of phosphorylation patterns in protein sequences. Using the data on phosphosites found in amino acid sequences, we mapped these sites onto 3D structures and studied the structural variability of the same sites in different PDB entries related to the same proteins. Solvent accessibility was calculated for the residues known to be phosphorylated. A significant change in accessibility was shown for many sites, but several ones were determined as buried in all the structures considered. Most phosphosites were found in coil regions. However, a significant portion was located in the structurally stable ordered regions. Comparison of structures with the same sites in modified and unmodified states showed that the region surrounding a site could be significantly shifted due to phosphorylation. Comparison between non‐modified structures (as well as between the modified ones) suggested that phosphorylation stabilizes one of the possible conformations. The local structure around the site could be changed due to phosphorylation, but often the initial conformation of the site surrounding is not altered within bounds of a rather large substructure. In this case, we can observe an extensive displacement within a protein domain. Phosphorylation without structural alteration seems to provide the interface for domain‐domain or protein‐protein interactions. Accounting for structural features is important for revealing more specific patterns of phosphorylation. It is also necessary for explaining structural changes as a basis for regulatory processes.
Crystal structure of D‐glycero‐Β‐D‐manno‐heptose‐1‐phosphate adenylyltransferase fromBurkholderia pseudomallei
Authors: Park Jimin , Kim Hyojin , Kim Suwon , Lee Daeun , Kim Mi‐Sun , Shin Dong Hae 
Published: October 2017

AbstractThe crystal structure of HldC fromB. pseudomallei(BpHldC), the fourth enzyme of the heptose biosynthesis pathway, has been determined.BpHldC converts ATP andd‐glycero‐β‐d‐manno‐heptose‐1‐phosphate into ADP‐d‐glycero‐β‐d‐manno‐heptose and pyrophosphate. The crystal structure ofBpHldC belongs to the nucleotidyltransferase α/β phosphodiesterase superfamily sharing a common Rossmann‐like α/β fold with a conserved T/HXGH sequence motif. The invariant catalytic key residues ofBpHldC indicate that the core catalytic mechanism ofBpHldC may be similar to that of other closest homologues. Intriguingly, a reorientation of the C‐terminal helix seems to guide open and close states of the active site for the catalytic reaction.
Sublethal effects of four insecticides on folding and spinning behavior in the rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae)
Authors: Yang Yajun , Wang Caiyun , Xu Hongxing , Lu Zhongxian 
Published: October 2017

AbstractBACKGROUNDThe rice leaffolder, Cnaphalocrocis medinalis, is an important rice pest. The sublethal effects of chlorpyrifos, chlorantraniliprole, emamectin benzoate and spinosad were investigated on the folding and spinning behaviors of third‐ to fifth‐instar C. medinalis larvae (L3 − L5) after insecticidal exposure of the second instar.RESULTSA 25% lethal concentration (LC25) of chlorpyrifos prolonged the leaf selection time of L5, and reduced the number of binds per primary fold for L4 and L5. An LC10 of chlorantraniliprole reduced the number of binds per primary fold for L4 and increased the number of head swings per bind for L5. An LC10 of emamectin benzoate shortened the primary fold length for L5 and decreased the number of head swings per primary fold for L3 and L4 and the number of head swings per bind for L3, while an LC25 of emamectin benzoate shortened the fold length per 24 h for L5 and folding time for L3. An LC10 of spinosad lowered the fold length per 24 h and the number of head swings for L5. An LC25 of spinosad prolonged leaf selection time, and decreased primary fold length, binds per primary fold, binds per fold and fold length per 24 h in L5.CONCLUSIONEmamectin benzoate and spinosad exerted stronger sublethal effects on the folding and spinning behavior of C. medinalis than chlorpyrifos and chlorantraniliprole. These results provide better understanding of the sublethal effects of interactions of insecticides on C. medinalis. © 2017 Society of Chemical Industry