bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone Turnover in Young Adult Men: Cross-Sectional Determinants and Associations With Prospectively Assessed Bone Loss
Authors: Verroken Charlotte , Zmierczak Hans-Georg , Goemaere Stefan , Kaufman Jean-Marc , Lapauw Bruno
Published: October 2017

Biochemical markers of bone turnover are higher in young adult men than in middle-aged men or young adult women. Nonetheless, little is known about the determinants and clinical significance hereof. The present study examined determinants of serum bone turnover markers in men around peak bone mass age, and explored whether bone turnover at this age predicts subsequent changes in bone mass. We used cross-sectional and longitudinal data from 973 and 428 healthy men, respectively, aged 25 to 45 years at baseline, including baseline procollagen type I amino-terminal propeptide (P1NP), osteocalcin, and C-terminal telopeptide of type I collagen (CTX) from fasting serum samples, baseline questionnaire-assessed physical activity levels, and baseline and follow-up dual-energy X-ray absorptiometry–derived areal bone mineral density (aBMD) and body composition. Mean follow-up time was 12.4 ± 0.4 years. At baseline, all bone turnover markers were inversely associated with total body fat mass (β ≤ –0.20, p < 0.001), and positively with physical activity during sports activities (β ≥ 0.09, p ≤ 0.003), and, albeit not independently from fat mass, total body lean mass (β ≥ 0.20, p ≤ 0.003). Mean annual aBMD changes in the longitudinal cohort were –0.19% ± 0.24% at the total body, –0.14% ± 0.42% at the spine, –0.49% ± 0.47% at the femoral neck, and –0.25% ± 0.37% at the total hip (all p < 0.001). Higher bone turnover markers at baseline were associated with larger decreases in aBMD at all measurement sites (β ≤ –0.08, p ≤ 0.081 for P1NP; β ≤ –0.16, p ≤ 0.002 for osteocalcin; and β ≤ –0.21, p < 0.001 for CTX). In conclusion, our findings show that sports activities and body composition, primarily fat mass, are the main identified determinants of bone turnover in men around peak bone mass age. Further, bone turnover at this age is an important determinant of subsequent changes in bone mass, with higher levels of bone turnover markers being associated with greater decreases in aBMD. © 2017 American Society for Bone and Mineral Research.
Depletion of Mast Cells and Macrophages Impairs Heterotopic Ossification in an Acvr1R206H Mouse Model of Fibrodysplasia Ossificans Progressiva
Authors: Convente Michael R , Chakkalakal Salin A , Yang EnJun , Caron Robert J , Zhang Deyu , Kambayashi Taku , Kaplan Frederick S , Shore Eileen M
Published: October 2017

Heterotopic ossification (HO) is a clinical condition that often reduces mobility and diminishes quality of life for affected individuals. The most severe form of progressive HO occurs in those with fibrodysplasia ossificans progressiva (FOP; OMIM #135100), a genetic disorder caused by a recurrent heterozygous gain-of-function mutation (R206H) in the bone morphogenetic protein (BMP) type I receptor ACVR1/ALK2. In individuals with FOP, episodes of HO frequently follow injury. The first sign of active disease is commonly an inflammatory “flare-up” that precedes connective tissue degradation, progenitor cell recruitment, and endochondral HO. We used a conditional-on global knock-in mouse model expressing Acvr1R206H (referred to as Acvr1cR206H/+) to investigate the cellular and molecular inflammatory response in FOP lesions following injury. We found that the Acvr1 R206H mutation caused increased BMP signaling in posttraumatic FOP lesions and early divergence from the normal skeletal muscle repair program with elevated and prolonged immune cell infiltration. The proinflammatory cytokine response of TNFα, IL-1β, and IL-6 was elevated and prolonged in Acvr1cR206H/+ lesions and in Acvr1cR206H/+ mast cells. Importantly, depletion of mast cells and macrophages significantly impaired injury-induced HO in Acvr1cR206H/+ mice, reducing injury-induced HO volume by ∼50% with depletion of each cell population independently, and ∼75% with combined depletion of both cell populations. Together, our data show that the immune system contributes to the initiation and development of HO in FOP. Further, the expression of Acvr1R206H in immune cells alters cytokine expression and cellular response to injury and unveils novel therapeutic targets for treatment of FOP and nongenetic forms of HO. © 2017 American Society for Bone and Mineral Research.
Association study of polymorphisms in the ABO gene and their gene‐gene interactions with ischemic stroke in Chinese population
Authors: Li Hao , Cai Yong , Xu An‐Ding
Published: October 2017

Aims

To investigate the impact of 4 single nucleotide polymorphisms (SNPs) within ABO gene and their gene‐gene interactions on ischemic stroke (IS) susceptibility in Chinese Han population.

Methods

A total of 1993 participants (1375 males, 618 females) were selected, including 991 IS patients and 1002 normal controls. The SNPstats (http://bioinfo.iconcologia.net/SNPstats) was used for Hardy‐Weinberg equilibrium (HWE) test. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best interaction combination among 4 SNPs within ABO gene. Logistic regression was performed to calculate the ORs (95%CI) for interaction between SNPs.

Results

Both rs579459 and rs505922 within ABO gene were associated with IS risk in additive and dominant models. IS risks were higher in those with minor alleles of rs579459 and rs505922 than those with wild‐type homozygotes, OR (95%CI) were 1.62 (1.19‐2.10) and 1.69 (1.23‐2.18), respectively. We did not find any relation of rs651007 and rs529565 with IS risk in both additive and dominant models. GMDR model indicated a significant two‐locus model (P = .0010) involving rs505922 and rs579459, indicating a potential interaction between rs505922 and rs579459, the cross‐validation consistency of the two‐locus models was 9/10, and the testing accuracy was 60.72%. We also found that participants with rs505922‐ TC/CC and rs579459‐ TC/CC genotype have the highest IS risk, compared to participants with rs505922‐ TT and rs579459‐ TT genotype, OR (95%CI) was 2.94 (1.28‐4.66).

Conclusions

We found that rs579459 and rs505922 within ABO gene and their interaction were both associated with increased IS risk in Chinese population.
Evaluation of the highly sensitive chemiluminescent enzyme immunoassay “Lumipulse HBsAg‐HQ” for hepatitis B virus screening
Authors: Deguchi Matsuo , Kagita Masanori , Yoshioka Nori , Tsukamoto Hiroko , Takao Miyuki , Tahara Kazuko , Maeda Ikuhiro , Hidaka Yoh , Yamauchi Satoshi , Kaneko Atsushi , Miyakoshi Hideo , Isomura Mitsuo
Published: October 2017

Background

Ongoing efforts in the development of HBsAg detection kits are focused on improving sensitivity and specificity. The purpose of this study was to evaluate an improved, highly sensitive quantitative assay, “Lumipulse HBsAg‐HQ”, a chemiluminescent enzyme immunoassay designed for a fully automated instrument, the “Lumipulse G1200”.

Methods

Serum samples for reproducibility, dilution, correlation, sensitivity, and specificity studies were obtained from patients at the Osaka University Hospital. Seroconversion and sensitivity panels were purchased from a commercial vender. Subtype, sensitivity panels, and HBsAg recombinant proteins with one or two amino acid substitutions were prepared in‐house.

Results

The coefficients of variation for the low, medium, and high concentration samples ranged from 1.93 to 2.55%. The HBsAg‐HQ reagent for dilution testing showed good linearity in the 0.005‐150 HBsAg IU/mL range and no prozone phenomenon. All 102 HBV carrier samples were positive by HBsAg‐HQ, while other commercial reagents showed one or more to be negative. In the seroconversion panel, the 14‐day blood sample was positive. The sensitivity against HBsAg‐HQ “ad” and “ay” subtypes was 0.025 ng/mL. Comparisons among the HBsAg‐HQ, HISCL, and Architect HBsAg reagents were performed using the Bland‐Altman plot. Specificity for 1000 seronegative individuals was 99.7%. HBsAg‐HQ detected 29 positive serum among 12 231 routinely obtained serum samples, which showed concentrations of 0.005‐0.05 HBsAg IU/mL.

Conclusions

According to these results, the Lumipulse HBsAg‐HQ assay, with a highly sensitive limit of detection of 0.005 IU/mL, may facilitate the development of a better management strategy for a considerable proportion of infected patients.
The effect of hot water pretreatment on the heavy metal adsorption capacity of acid insoluble lignin from Paulownia elongata
Authors: Chen Hanchi , Liu Ni , Qu Xiaolin , Joshee Nirmal , Liu Shijie
Published: October 2017

BACKGROUND

Biorefinery processes utilize carbohydrates from biomass in order to produce biochemical and biomaterials. Lignin as the byproduct after biorefinery needs to be studied for applications. This study evaluated how hot water pretreatment, a typical biorefinery process, will impact on the heavy metal adsorption capacity of lignin.

RESULTS

Paulownia elongata acid insoluble lignin was tested for its heavy metal adsorption capacities for Pb(II), Cu(II) and Cd(II). Hot water pretreatment was conducted on the lignin with both water and dilute acetic acid solution. Samples with both increased and decreased adsorption capacity were observed after the pretreatment, while samples with long duration of pretreatment encountered a substantial loss in the adsorption ability. Depolymerization and condensation lignin reaction schemes under acidic environment were summarized and applied to explain the capacity changes. NMR analysis was performed to quantify the functional groups in the lignin samples. Changes in the amount of functional groups were found in the samples after pretreatment.

CONCLUSION

Hot water pretreatment can either increase or decrease the adsorption capacity of lignin depending on the treatment duration. Lignin byproducts after treatment under acidic and high temperature environments with long duration is no longer suggested for use as a heavy metal adsorbent. © 2017 Society of Chemical Industry
Computer‐aided diagnosis software for vulvovaginal candidiasis detection from Pap smear images
Authors: Momenzadeh Mohammadreza , Vard Alireza , Talebi Ardeshir , Mehri Dehnavi Alireza , Rabbani Hossein
Published: October 2017

Vulvovaginal candidiasis (VVC) is a common gynecologic infection and it occurs when there is overgrowth of the yeast called Candida. VVC diagnosis is usually done by observing a Pap smear sample under a microscope and searching for the conidium and mycelium components of Candida. This manual method is time consuming, subjective and tedious. Any diagnosis tools that detect VVC, semi‐ or full‐automatically, can be very helpful to pathologists. This article presents a computer aided diagnosis (CAD) software to improve human diagnosis of VVC from Pap smear samples. The proposed software is designed based on phenotypic and morphology features of the Candida in Pap smear sample images. This software provide a user‐friendly interface which consists of a set of image processing tools and analytical results that helps to detect Candida and determine severity of illness. The software was evaluated on 200 Pap smear sample images and obtained specificity of 91.04% and sensitivity of 92.48% to detect VVC. As a result, the use of the proposed software reduces diagnostic time and can be employed as a second objective opinion for pathologists.
The micromorphological characterization of adhesive bond in dentin different locations
Authors: Ramic Bojana D. , Drobac Milan R. , Stojanac Igor L. , Premovic Milica T. , Petrovic Ljubomir M.
Published: October 2017

The aim of this study was to analyse the interfacial micromorphology of total‐etch adhesives and dentin structures different locations by using SEM. Standardized cylindrical cavities (3mm in diameter, 2mm deep) with all margins in dentin were prepared on occlusal and buccal surfaces of twenty extracted human third molars. A total‐etch dentin adhesive system and a light‐cure flowable composite (Filtek Ultimate Flowable, 3M ESPE, St. Paul, MN, USA) were used in this study. Micro‐morphological SEM analysis of the marginal seal of the original tooth specimens was performed using high magnification of up to 1000×. In this study, we found the difference in interfacial micromorphology in dentin different locations. Also, marginal gap was found in both observed dentin area. Better understanding of complexity and three‐ dimensional variations of the tooth structure is important for prevention of clinical challenges such as postoperative sensitivity, marginal discoloration and secondary caries, which could be prevented by achieving of predictable and long‐lasting adhesive bond.
Adhesion, unfolding forces, and molecular elasticity of fibronectin coatings: An atomic force microscopy study
Authors: Sumarokova Maria , Iturri Jagoba , Toca‐Herrera José L.
Published: October 2017

Fibronectin is an extracellular matrix protein that is involved in cell adhesion, growth, migration, differentiation, and wound healing. Fibronectin coatings are currently used in many laboratories for biomedical and biotechnology purposes. In this study we have investigated the adhesion and mechanical properties of fibronectin coatings. The coatings were also used to study the role of the residence time and the influence of the loading rate in nonspecific interactions. The results showed that the adhesion force between silica and fibronectin increased with loading rate delivering similar values for residence times of 1 and 2 s. Further analysis indicated that the distance to the transition state was about 0.5 nm. Moreover, the adhesion force did not vary with the loading rate for contact time of 0 s. The unfolding of fibronectin domains also depended of the Dwell time (no unfolding events were observed for zero residence time). Applied loads of 2 nN were able to stretch the fibronectin layer up to 200 nm and to unfold the three fibronectin domains, which were similar for a Dwell time of 1 and 2 s. However, the unfolding length increased with loading rate: below 2.5 µm s−1 the obtained lengths matched the value of FN I (13.5 nm), while for higher speeds the measured values corresponded to the lengths of FN II (18 nm) and FN III (27 nm). This investigation has answered and opened new questions about the mechanical stability and function of fibronectin coatings. The results have also raised theoretical questions about the difference between specific and nonspecific interactions to be addressed in future work.
Total synthesis of [13C]2‐, [13C]3‐, and [13C]5‐isotopomers of xanthohumol, the principal prenylflavonoid from hops
Authors: Ellinwood Duncan C. , El‐Mansy Mohamed F. , Plagmann Layhna S. , Stevens Jan F. , Maier Claudia S. , Gombart Adrian F. , Blakemore Paul R.
Published: October 2017

Xanthohumol [(E)‐6′‐methoxy‐3′‐(3‐methylbuten‐2‐yl)‐2′,4′,4″‐trihydroxychalcone], he principal prenylated flavonoid from hops, has a complex bioactivity profile, and 13C‐labeled isotopomers of this compound are of potential use as molecular probes and as analytical standards to study metabolism and mode of action. 1,3‐[13C]2‐Xanthohumol was prepared by an adaptation of the total synthesis of Khupse and Erhardt in 7 steps and 5.7% overall yield from phloroglucinol by a route incorporating a cascade Claisen‐Cope rearrangement to install the 3′‐prenyl moiety from a 5′‐prenyl aryl ether and an aldol condensation between 1‐[13C]‐2′,4′‐bis(benzyloxymethyloxy)‐6′‐methoxy‐3′‐(3‐methylbuten‐2‐yl)acetophenone and 1′‐[13C]‐4‐(methoxymethyloxy)benzaldehyde. The 13C‐atom in the methyl ketone was derived from 1‐[13C]‐acetyl chloride while that in the aryl aldehyde was derived from [13C]‐iodomethane. Tri‐ and penta‐13C‐labeled xanthohumols were similarly prepared by applying minor modifications to the route.
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

This 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

This 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

Cannabis 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

Objective

To 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).

Methods

Forty‐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.

Results

In 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.

Conclusion

In 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.
Hyper Branched Silica Precursor Poly(alkoxysiloxane): Influence of Alkyl Group Modification on Thermal Stability and Conversion to Silica
Authors: Swaton‐Höckels Michael , Peter Karin , Möller Martin
Published: October 2017

Alkyl group modified hyper branched poly(alkoxysiloxane)s (PAOS) were synthesized via a one‐pot co‐monomer route based on a non‐aqueous condensation reaction. By using tri(ethoxyalkylsilane) as co‐monomer we are able to introduce a high amount of alkyl groups into the PAOS molecule. The chemical structure and degree of modification were analyzed by 29Si‐NMR and GPC. According to thermal gravimetric analysis (TGA) the conversion of PAOS to silica is highly affected by type and the content of the modifying units. With increasing of both the chain length and the quantity of alkyl groups the rate of conversion of PAOS to silica is decreased. Additionally, we discuss the influence of atmosphere and temperature on the degree of conversion to silica within a defined time.
Synthesis and Study of Organosoluble Aromatic Cardo (co)polyamides and Their Application in the Optical Fiber Primary Coating Technology
Authors: Sapozhnikov Dmitriy A. , Bayminov Bato A. , Popova Nadezhda A. , Zabegaeva Olesya N. , Alekseyeva Diana D. , Semjonov Sergey L. , Kosolapov Alexey F. , Plastinin Evgeniy A. , Vygodskii Yakov S.
Published: October 2017

A series of organosoluble aromatic cardo copolyamides (PA) with chlorine and carboxylic side groups has been synthesised by low‐temperature polycondensation in N‐methyl‐2‐pyrrolidone (N‐MP) solution and their properties have been estimated. The obtained polymers are differed in high molar masses (ηinh = 0.7 ÷ 1.8 dL/g) and demonstrate the following thermal characteristics: 300 °C < Tg < 390 °C; 425 °C < T10% < 510 °C (in air). PA films are characterized by high tensile strength (100 ÷ 230 MPa) and modulus (1.6 ÷ 2.3 GPa). It was stated the obtained PAs form the high quality coatings with good adhesion to the optical fiber surface without any additional coupling agent. The fibers with elaborated PA coatings demonstrate high thermal stability. The study of the optical fiber bending strength before and after thermal tests has shown that this parameter decreases by 10% only after prolonged exposure to high temperatures, namely, 72 h at 200–300 °C. Some samples withstand more than 1 h treatment at 350 °C without any changes of the optical fiber bending strength.
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

Laser 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

Background

In 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.

Methods

A 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.

Results

Overall, 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).

Conclusion

The 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

Background

Foot 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 Methods

We 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.

Results

The 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.

Conclusions

TDAP flaps with long vascular pedicles may be a viable choice for reconstructing defects in the feet of diabetic patients.
Boundedness and stabilization in a two‐species chemotaxis‐competition system of parabolic‐parabolic–elliptic type
Authors: Mizukami Masaaki
Published: October 2017

This paper is concerned with the two‐species chemotaxis‐competition system

urn:x-wiley:mma:media:mma4607:mma4607-math-0001
where Ω is a bounded domain in
with smooth boundary ∂Ω, n≥2; χi and μi are constants satisfying some conditions. The above system was studied in the cases that a1,a2∈(0,1) and a1>1>a2, and it was proved that global existence and asymptotic stability hold when
are small. However, the conditions in the above 2 cases strongly depend on a1,a2, and have not been obtained in the case that a1,a2≥1. Moreover, convergence rates in the cases that a1,a2∈(0,1) and a1>1>a2 have not been studied. The purpose of this work is to construct conditions which derive global existence of classical bounded solutions for all a1,a2>0 which covers the case that a1,a2≥1, and lead to convergence rates for solutions of the above system in the cases that a1,a2∈(0,1) and a1≥1>a2.
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

Purpose

To 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 materials

We 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.

Results

The 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.

Conclusion

Our 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

Purpose

We 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.

Methods

Under 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.

Results

The 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.

Conclusions

The 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

We 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.
Synergistic flame‐retardant effect and mechanisms of boron/phosphorus compounds on epoxy resins
Authors: Tang Shuo , Qian Lijun , Qiu Yong , Dong Yuping
Published: October 2017

To explore the component synergistic effect of boron/phosphorus compounds in epoxy resin (EP), 3 typical boron compounds, zinc borate (ZB), boron phosphate (BPO4), and boron oxide (B2O3), blended with phosphaphenanthrene compound TAD were incorporated into EP, respectively. All 3 boron/phosphorus compound systems inhibited heat release and increased residue yields and exerted smoke suppression effect. Among 3 boron/phosphorus compound systems, B2O3/TAD system brought best flame‐retardant effect to epoxy thermosets in improving the UL94 classification of EP composites and also reducing heat release most efficiently during combustion. B2O3 can interact with epoxy matrix and enhance the charring quantity and quality, resulting in obvious condensed‐phase flame‐retardant effect. The combination of condensed‐phase flame‐retardant effect from B2O3 and the gaseous‐phase flame‐retardant effect from TAD effectively optimized the action distribution between gaseous and condensed phases. Therefore, B2O3/TAD system generated component synergistic flame‐retardant effect in epoxy thermosets.
The effect of eccentricity of load on the behavior of compressed composite columns in critical state
Authors: Wysmulski Pawel , Debski Hubert
Published: October 2017

The study concerns a short thin‐walled channel section column made of carbon‐epoxy laminate. The tested column was subjected to compression, including an eccentric compression force relative to the gravity center of the cross‐section of the column toward its higher rigidity. The boundary conditions applied in the study reflected articulated, simple support of the column's ends. The scope of the study included determination of the effect of eccentric load on the structure's buckling mode and critical load. The critical load of the real structure was determined using approximation methods based on the post‐critical equilibrium paths of the structure obtained in experimental tests. At the same time, a numerical analysis by the finite element method was performed using the commercial simulation software Abaqus®. The numerical analysis involved solving an eigenproblem to determine the buckling mode of the structure and to determine the critical load of this structure under axial and eccentric load. The experimental results were used to verify the developed numerical models. The analysis enabled determination of the effect of eccentric load on the structure's buckling mode and critical load, which is of vital importance for the design of thin‐walled real structures that are coated with reinforcing thin‐walled stiffeners. Examples of such constructions include thin‐walled stressed‐skin structures such as an aircraft's main body section and wings, where the thin skin or outer covering is reinforced by a series of longitudinal profiles with open and closed sections. POLYM. COMPOS., 40:70–77, 2019. © 2017 Society of Plastics Engineers
The relevance of material and processing parameters on the thermal conductivity of thermoplastic composites
Authors: Wieme Tom , Tang Dahang , Delva Laurens , D'hooge Dagmar R. , Cardon Ludwig
Published: October 2017

Thermoplastics composites show vast promise as an alternative for thermal management applications in the scope of the development of next‐generation electronics and heat exchangers. Their low cost, reduced weight, and corrosion resistance make them an attractive replacer for traditionally used metals, in case their thermal conductivity (TC) can be sufficiently increased by designing the material (e.g., filler type and shape) and processing (e.g., dispersion quality, mixing, and shaping) parameters. In the present contribution, the relevance of both types of parameters is discussed, and guidelines are formulated for future research to increase the TC of thermoplastic polymer composites. POLYM. ENG. SCI., 58:466–474, 2018. © 2017 Society of Plastics Engineers
Large strain, high rate semi‐solid deformation of high density polyethylene at elevated temperatures
Authors: McKelvey D. , Menary G.H. , Martin P.J. , Yan S.
Published: October 2017

High density polyethylene (HDPE) is predominately processed from the molten state. However, there is the potential to enhance the mechanical properties by forming below the melt temperature, in the semi‐solid phase. To further investigate this enhancement, HDPE sheets were deformed under constant width, simultaneous equal‐biaxial (EB), and sequential biaxial deformation. The samples were deformed at strain‐rates, from 4 to 16 s−1, up to nominal strains of 3.0 at temperatures below 130°C. The strain‐rate and high‐strain level applied were chosen so that the data was comparable to the thermoforming process. It was discovered that in order for the HDPE sheet to deform at the high‐rate and high strains the processing temperature must be between 126°C and 130°C. This resulted in a processing window that was particularly small, 5°C, and that within this window a temperature change of 1°C had a significant impact on the stress–strain response. The samples were analyzed post deformation, where the elastic modulus was found to increase by a factor of 2.08 in the machine direction, when deformed via EB at 129°C. The results showed that HDPE can be deformed to strain levels comparable to the thermoforming process. POLYM. ENG. SCI., 58:1516–1522, 2018. © 2017 Society of Plastics Engineers
Preparation of electrospun polyurethane/hydrophobic silica gel nanofibrous membranes for waterproof and breathable application
Authors: Gu Xianyuan , Li Ni , Cao Jin , Xiong Jie
Published: October 2017

The polyurethane (PU)/hydrophobic silica gel (HSG) fibrous membranes with the hydrophobic and breathable surface was fabricated via electrospinning. By employing the HSG incorporation, mechanical properties, thermal stability, and waterproofness of the composite membranes could be improved. The porous structure of the membranes would be regulated by tuning the temperatures of thermal treatment. When HSG content increased to 3 wt%, the PU/HSG composite membranes possessed remarkable tensile strength of 6.3 MPa and high water contact angle (WCA) of 134°. Furthermore, the maximum WCA (142° ± 1°), good hydrostatic pressure (5.45 kPa), large water vapor transmission rate (8.05 kg/m2/day), and high air permeability (9.25 L/m2/s) of the composite membranes could be achieved by heat treatment at 120°C. The resultant membranes performed significantly better when compared to the pure PU membranes under the same conditions, such as the higher tensile strength (100%), better waterproofness (200%), and stronger breathablity (25%). POLYM. ENG. SCI., 58:1381–1390, 2018. © 2017 Society of Plastics Engineers
Evaluation of the quality of postconsumer plastics obtained from disassembly‐based recycling strategies
Authors: Wagner F. , Peeters J. , De Keyzer J. , Duflou J. , Dewulf W.
Published: October 2017

The focus of the presented research is on the mechanical recycling of postconsumer plastics from Waste Electrical and Electronic Equipment (WEEE). Currently only a limited number of these plastics are mechanically recycled on an industrial scale while the majority is thermally treated for energy recovery. Since there is a significant potential for value recovery and to lower the environmental impact of plastics, the aim of this research is to develop new mechanical recycling processes based on the disassembly of plastic components and the sorting of these plastics based on identification by spectroscopic methods. This study will present this distinct recycling process based on a case study of the recycling of Acrylonitrile Butadiene Styrene terpolymer (ABS) from Liquid Crystal Display (LCD) TVs. The quality of the recyclates is evaluated by mechanical testing and injection molding of thin‐walled products. Results showed that with direct reapplication of the obtained ABS without compounding, high mechanical properties could be achieved when compared to postshredder recycled ABS. However, remaining impurities in the polymer matrix limit the applicability of the recycled plastics to components without neither structurally critical nor aesthetical requirements. POLYM. ENG. SCI., 58:485–492, 2018. © 2017 Society of Plastics Engineers
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

Numerous 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

Protein 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.