bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Roll Restoring Arm Variation Using a Three-Dimensional Hybrid Panel Method
Authors: Bu Shu Xia , Gu Min , Abdel-Maksoud Moustafa
Published: January 2019

Providing a reliable numerical tool for the prediction of parametric roll and pure loss of stability is a difficult task. It is acknowledged that the occurrence of these two failure modes is mainly attributed to the variation of roll restoring arm, which should be calculated accurately. This work studies exclusively the roll restoring arm variation numerically and experimentally. First, partially restrained experimental tests at different constant heeling angles (up to 30°) are conducted to measure the variation of roll restoring arm in regular waves. Second, a numerical method for the calculation of roll restoring arm in waves taking radiation and diffraction moments into account is adopted. The calculation results are benchmarked against experimental model test data. Third, the characteristics of roll restoring arm variation and the effects of radiation and diffraction moments on roll restoring arm variation (GZRD) in head and following seas are investigated. Finally, the feasibility of GZ calculated by the integral of instantaneously average wetted surface is studied by comparing the results with that calculated by the integral of the fully instantaneously wetted surface. The research show that the GZRD can be ignored in following seas. The GZ in head seas consists of two important harmonic components, and GZRD is the main contribution of the second harmonic component. Therefore, GZRD should be calculated with consideration of the instantaneous heeling angles and Froude number in head seas, especially for the prediction of large amplitude roll motion at high speed.

1. Introduction

Currently, the second-generation intact stability criteria are under development by the International Maritime Organization (IMO) (IMO SLF 53/WP.1-Add.1 2011; IMO SDC 3/WP.5 2016). Five different kinds of potentially dangerous dynamic stability failure modes in waves were proposed. Parametric roll and pure loss of stability are two of the stability failure modes that may lead to capsizing of a ship. According to the proposed drafts, a multilevel structure was adopted to make sure that numerical assessment procedures are only applied when the vulnerability to dynamical stability failures is beyond reasonable doubt. Assessment of the vulnerability criteria is normally based on simplified geometry characteristics or empirical formulas. However, direct stability assessment requires highly accurate prediction (Kobylinski 2012).
Modèle conceptuel de circulation hydrogéologique au niveau de l’aquifère plioquaternaire de Settat (Maroc) : étude hydrogéochimique
Authors: Paaza Namira El Amrani , Larocque Marie , Herrera José Benavente
Published: January 2019

La région de Settat a connu durant ces deux dernières décennies une croissance démographique importante et un essor économique majeur par l’implantation d’une zone industrielle. En plus, cette région est connue par son caractère agricole, surtout en cultures céréalières (grenier du Maroc). Cette croissance a été accompagnée par une augmentation des débits des effluents liquides urbains et industriels qui sont directement évacués dans l’oued Boumoussa considéré comme égout à ciel ouvert et qui ont induit une détérioration de la qualité de ces eaux. Tout cela a eu un impact sur l’aquifère de Settat du point de vue hydrodynamique et de qualité des eaux souterraines. Pour pallier à cette problématique, une étude pluridisciplinaire a été menée au moyen de l’analyse physicochimique et de l’analyse des isotopes stables de l’eau. Les études antérieures et les analyses présentées ici révèlent une pollution chimique des eaux de la nappe par les écoulements superficiels de l'oued Boumoussa. Les résultats montrent la présence d’un phénomène d’évaporation de l’eau souterraine ainsi que la présence d'un recyclage des eaux d’irrigation qui se mêlent à la recharge naturelle (précipitation) pour alimenter l'aquifère de Settat. Les résultats ont permis de proposer, sur la base des données physicochimiques et isotopiques, un modèle conceptuel de circulation des eaux au niveau de l’aquifère plioquaternaire de Settat pour une meilleure gestion de la ressource en eau.
The capability of the red seaweed Gracilaria vermiculophylla in producing prostaglandins
Authors: Illijas Muhammad Ikbal , Nasir Andriani , Dahlia Dahlia , Arma Nur Rahmawaty , Itabashi Yutaka
Published: January 2019

The red seaweed G. vermiculophylla is rich in polyunsaturated fatty acids with 20 carbon atoms, mainly arachidonic acid (AA) and eicosapentaenoic acid, which are precursors of prostaglandins (PGs). The present study aimed to elucidate the capability of the seaweed in releasing PGs using acetone powder as the crude enzyme. Crude enzyme was prepared using cold acetone. The crude enzyme was incubated with AA at different concentrations (0.1– 4 mg). For determination of PG contents, 5 µL of sample as the test solution corresponding to 0.2 g wet mass of the seaweed was injected into the HPLC. For mass spectrometer analysis, an HPLC system connected with mass spectrometer was used. Results of the study showed that t he released PGs from incubation of acetone powder and AA analyzed by HPLC consisted of PGE 2 , 15-keto-PGE 2 , 15-hydroperoxy-PGE 2 , PGA 2 , and AA while PGs detected by LC-MS were PGF 2α , PGE 2 , 15-keto-PGE 2 , 15-hydroperoxy-PGE 2 , and PGA 2 . The capability of the red algae in producing PGs was affected by available oxygen, aspirin, a cyclooxygenase inhibitor, and AA concentration. The crude enzyme of the red alga (250 mg) was capable to produce 1.63 µg and 1.32 µg of PG 2 and 15-keto-PGE 2 from incubation with 0.25 mg of AA. This method could be the one way to provide PGs in vitro to fulfill demands of PGs in the pharmaceutical industry.
New clinical trial designs in the era of precision medicine
Authors: Garralda Elena , Dienstmann Rodrigo , Piris‐Giménez Alejandro , Braña Irene , Rodon Jordi , Tabernero Josep
Published: January 2019

Cancer treatment has made significant strides towards the promise of personalized medicine. Recent scientific advances have shown that there are numerous genetic deregulations that are common in multiple cancer types, raising the possibility of developing drugs targeting those deregulations irrespective of the tumour type. Precision Cancer Medicine (PCM) was born out of accumulated evidence matching targeted agents with these tumour molecular deregulations. At the same time, the therapeutic armamentarium is rapidly increasing and the number of new drugs (including immune‐oncology agents) entering drug development continues to rise. These factors, added to strong collaboration with regulatory agencies, which have approved novel agents based on data obtained from phase 1/2 trials, have led to unprecedented evolution in the design of early‐stage clinical trials. Currently, we have seen rapid phase 1 dose‐escalation trials followed by remarkably large expansion cohorts, and are witnessing the emergence of new trials, such as adaptive studies with basket and umbrella designs aimed at optimizing the biomarker–drug co‐development process. Alongside the growing complexity of these clinical trials, new frameworks for stronger and faster collaboration between all stakeholders in drug development, including academic institutions and frameworks, clinicians, pharma companies and regulatory agencies, have been established. In this review article, we describe the main challenges and opportunities that these new trial designs may provide for a more efficient drug development process, which may ultimately help ensure that PCM becomes a reality for patients.
Incorporating clickers into an enzymology course improves student performance
Authors: Stines‐Chaumeil Claire , Paumard Patrick , Hooks Mark A.
Published: January 2019

Here, we describe how poor exam results of undergraduate students enrolled in an enzymology course at the University of Bordeaux were improved through the introduction of ‘clickers’ as an audience response system. By using clickers only in a small‐group tutorial element of a large theoretical course, we observed an improvement in exam scores that resulted in a lower failure rate for the course. Furthermore, students of all abilities were found to benefit from their use. Students reported better retention of both lecture and tutorial content. An analysis of how clickers were employed within the tutorials indicated that the use of clickers to promote discussion and impart knowledge likely resulted in a moderate improvement of exam scores. We hypothesize that students were more prepared for exams through greater reflection of exam questions, resulting in an enhanced ability to retrieve memorized information and apply it within a time‐limited exam setting.
Glycol esters, glycol ethers – Method for the determination of propylene glycol monoethyl ether, 1‐ethoxy‐2‐propanol acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether in workplace air using gas chromatography [Air Monitoring Methods, 2018]
Authors: Giesen Y. , Friedrich C. , Breuer D. , Fauss J. , Hebisch R. , Brock T.H. , Hartwig A. ,   MAK Commission
Published: January 2019

This analytical method is a validated measurement procedure for the determination and limit value monitoring of 1‐ethoxy‐2‐propanol, 1‐ethoxy‐2‐propyl acetate, 2‐(2‐methoxyethoxy)ethanol, 2‐(2‐ethoxyethoxy)ethanol and 2‐(2‐butoxyethoxy)ethanol in workplace air. With this method simultaneously airborne glycols in the gaseous state as well as particles are collected. Sampling is performed by drawing a defined volume of air through the sampling system GGP‐Mini consisting of a glass fibre filter and a charcoal tube connected downstream using a suitable flow‐regulated pump. The flow rate is set to 0.33 L/min with a recommended air sample volume of 40 L. The collected glycols are desorbed with a mixture of dichloromethane/methanol containing 1‐hexanol as internal standard and then analysed by means of gas chromatography using FID. The quantitative evaluation is based on calibration functions obtained by means of multiple‐point calibrations. The limit of quantification (LOQ) for the individual glycol esters or glycol ethers is 0.5 mg/m
3
based on an air sample volume of 40 L.

Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the working group “Air Analyses” of the Permanent Senate Commission of the Deutsche Forschungsgemeinschaft for the Investigation of Health Hazards of Chemical Compounds in the Work Area.
Addendum to Benzene [BAT Value Documentation, 2018]
Authors: Kraus T. , Bader M. , Klotz K. , Weistenhöfer W. , Drexler H. , Hartwig A. ,   MAK Commission
Published: January 2019

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has derived biological reference values (BAR) and re‐evaluated the exposure equivalents for carcinogenic substances (EKA) for the urinary benzene metabolites S‐phenylmercapturic acid, t,t‐muconic acid and benzene in 2016. Available publications are described in detail.

The existing exposure equivalents for carcinogenic substances (EKA) for the benzene metabolites were re‐evaluated and extended especially to the low‐exposure range. For the parameter benzene in urine, new EKA were established.

Taking results of studies into consideration with persons of the general population not occupationally exposed to benzene, with sufficient number of cases and current biomonitoring methods, biological reference values (BAR) of 0.3 µg S‐phenylmercapturic acid/g creatinine, 150 µg t,t‐muconic acid/g creatinine and 0.3 µg benzene/L urine were established. Sampling time is at the end of exposure or the end of the working shift.
Addendum zu Aluminium [BAT Value Documentation in German language, 2019]
Authors: Klotz K. , Drexler H. , Hartwig A. ,   MAK Commission
Published: January 2019

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated a biological reference value (BAR) for aluminium [CAS No. 7429‐90‐5] in 2018. Available publications are summarised.

Considering the available studies analysing aluminium in urine, a BAR of 15 µg aluminium/g creatinine was established. Sampling time is for long‐term exposures: at the end of the shift after several shifts. For aluminium in blood, the data base is not sufficient for the evaluation of a BAR.
Diisotridecylphthalat, Ditridecylphthalat [MAK Value Documentation in German language, 2019]
Authors: Hartwig A. ,   MAK Commission
Published: January 2019

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated diisotridecyl phthalate (a mixture a various isomers) [
27253‐26‐5
] and ditridecyl phthalate [
119‐06‐2
] considering all toxicological endpoints. Available publications and unpublished study reports are described in detail. The critical effect is centrilobular hepatocyte hypertrophy following prolonged oral exposure of rats. There are signs of peroxisome proliferating activity which has also been observed with other phthalates like di(2‐ethylhexyl) phthalate. Diisotridecyl phthalate and ditridecyl phthalate are not genotoxic. No carcinogenicity study has been performed, but due to the similarity to di(2‐ethylhexyl) phthalate, liver carcinogenicity cannot be excluded. Therefore, diisotridecyl phthalate and ditridecyl phthalate are classified in Category 3B for suspected carcinogens.

Both phthalates cause at most minimal irritation to the eyes and skin of rabbits. As no inhalation study has been performed, possible long‐term effects on larynx and nasal goblet cells, the targets of other phthalates, cannot be evaluated. Therefore, no maximum concentration at the workplace (MAK value) can be derived.

Ditridecyl phthalate does not cause developmental toxicity in rats up to an oral dose of 100 mg/kg body weight and day, the highest dose tested. Skin contact is not expected to contribute significantly to systemic toxicity. Limited data show no sensitization.
Wasserstoffperoxid [MAK Value Documentation in German language, 2019]
Authors: Hartwig A. ,   MAK Commission
Published: January 2019

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of hydrogen peroxide [
7722‐84‐1
] as new inhalation studies are available.

Hydrogen peroxide is an irritant to the respiratory tract and the eyes.

In a 90‐day inhalation study in the rat a NOAEC of 7 ml/m
3
was determined, which confirms the previous 28‐day inhalation study and proves that the effects at the respiratory tract do not increase with exposure duration.

A new study of acute effects in volunteers suggests that hydrogen peroxide is slightly irritating at 2.2 ml/m
3
, but not at 0.5 ml/m
3
. These findings support all previously described results of inhalation studies in workers or volunteers.

Based on the NOAEC established for humans, the MAK value of 0.5 ml/m
3
is retained.

Peak Limitation Category I and the excursion factor of 1 are retained as there are no new data.
Crafting Mussel‐Inspired Metal Nanoparticle‐Decorated Ultrathin Graphitic Carbon Nitride for the Degradation of Chemical Pollutants and Production of Chemical Resources
Authors: Cai Jingsheng , Huang Jianying , Wang Shanchi , Iocozzia James , Sun Zhongti , Sun Jingyu , Yang Yingkui , Lai Yuekun , Lin Zhiqun
Published: January 2019

The development of efficient photocatalysts for the degradation of organic pollutants and production of hydrogen peroxide (H2O2) is an attractive two‐in‐one strategy to address environmental remediation concerns and chemical resource demands. Graphitic carbon nitride (g‐C3N4) possesses unique electronic and optical properties. However, bulk g‐C3N4 suffers from inefficient sunlight absorption and low carrier mobility. Once exfoliated, ultrathin nanosheets of g‐C3N4 attain much intriguing photocatalytic activity. Herein, a mussel‐inspired strategy is developed to yield silver‐decorated ultrathin g‐C3N4 nanosheets (Ag@U‐g‐C3N4‐NS). The optimum Ag@U‐g‐C3N4‐NS photocatalyst exhibits enhanced electrochemical properties and excellent performance for the degradation of organic pollutants. Due to the photoformed valence band holes and selective two‐electron reduction of O2 by the conduction band electrons, it also renders an efficient, economic, and green route to light‐driven H2O2 production with an initial rate of 0.75 × 10−6 m min−1. The improved photocatalytic performance is primarily attributed to the large specific surface area of the U‐g‐C3N4‐NS layer, the surface plasmon resonance effect induced by Ag nanoparticles, and the cooperative electronic capture properties between Ag and U‐g‐C3N4‐NS. Consequently, this unique photocatalyst possesses the extended absorption region, which effectively suppresses the recombination of electron–hole pairs and facilitates the transfer of electrons to participate in photocatalytic reactions.
Breaking the Depth Dependence by Nanotechnology‐Enhanced X‐Ray‐Excited Deep Cancer Theranostics
Authors: Fan Wenpei , Tang Wei , Lau Joseph , Shen Zheyu , Xie Jin , Shi Jianlin , Chen Xiaoyuan
Published: January 2019

The advancements in nanotechnology have created multifunctional nanomaterials aimed at enhancing diagnostic accuracy and treatment efficacy for cancer. However, the ability to target deep‐seated tumors remains one of the most critical challenges for certain nanomedicine applications. To this end, X‐ray‐excited theranostic techniques provide a means of overcoming the limits of light penetration and tissue attenuation. Herein, a comprehensive overview of the recent advances in nanotechnology‐enhanced X‐ray‐excited imaging and therapeutic methodologies is presented, with an emphasis on the design of multifunctional nanomaterials for contrast‐enhanced computed tomography (CT) imaging, X‐ray‐excited optical luminescence (XEOL) imaging, and X‐ray‐excited multimodal synchronous/synergistic therapy. The latter is based on the concurrent use of radiotherapy with chemotherapy, gas therapy, photodynamic therapy, or immunotherapy. Moreover, the featured biomedical applications of X‐ray‐excited deep theranostics are discussed to highlight the advantages of X‐ray in high‐sensitivity detection and efficient elimination of malignant tumors. Finally, key issues and technical challenges associated with this deep theranostic technology are identified, with the intention of advancing its translation into the clinic.
Chemical Nanomotors at the Gram Scale Form a Dense Active Optorheological Medium
Authors: Choudhury Udit , Singh Dhruv P. , Qiu Tian , Fischer Peer
Published: January 2019

The rheological properties of a colloidal suspension are a function of the concentration of the colloids and their interactions. While suspensions of passive colloids are well studied and have been shown to form crystals, gels, and glasses, examples of energy‐consuming “active” colloidal suspensions are still largely unexplored. Active suspensions of biological matter, such as motile bacteria or dense mixtures of active actin–motor–protein mixtures have, respectively, reveals superfluid‐like and gel‐like states. Attractive inanimate systems for active matter are chemically self‐propelled particles. It has so far been challenging to use these swimming particles at high enough densities to affect the bulk material properties of the suspension. Here, it is shown that light‐triggered asymmetric titanium dioxide that self‐propel, can be obtained in large quantities, and self‐organize to make a gram‐scale active medium. The suspension shows an activity‐dependent tenfold reversible change in its bulk viscosity.
Electron Beam‐Induced Microstructural Evolution of SnS2 Quantum Dots Assembled on N‐Doped Graphene Nanosheets with Enhanced Photocatalytic Activity
Authors: Chen Dayong , Huang Shoushuang , Huang Ruting , Zhang Qian , Le Thanh‐Tung , Cheng Erbo , Yue Rong , Hu Zhangjun , Chen Zhiwen
Published: January 2019

Development of photocatalysts for degradation of organic pollutants with low‐cost and robust stability remains as one of the most serious challenges. Herein, SnS2 quantum dots (QDs)/N‐doped graphene nanocomposites (SNGNSs) are successfully prepared by combining a hydrothermal process with an electron‐beam irradiation (EBI) technique. Due to the enhanced light absorption and efficient separation of photogenerated electrons and holes, the resultant SNGNSs display excellent photodegradation ability for methyl orange (MO). Additionally, it is found that an EBI treatment could further improve the photocatalytic activity of SNGNSs. Particularly, the as‐prepared SNGNSs irradiated under 70 kGy exhibit a photodegraded rate of 95.6% for the degradation of MO within 60 min, which is greatly superior to that of the unirradiated one (59.5%). The enhanced photocatalytic performance can be ascribed to the doping of nitrogen element into graphene nanosheets, the enhanced crystallinity of SnS2 QDs as well as the creating lattice defects in SnS2 QDs. This work suggests that EBI treatment is an effective strategy to modify the surface of graphene‐based nanocomposites, which displays widely potential applications for constructing carbon‐based photocatalysts with excellent catalytic ability and developing high‐performance photoelectronic devices.
Impact of Initial Bulk‐Heterojunction Morphology on Operational Stability of Polymer:Fullerene Photovoltaic Cells
Authors: Limbu Saurav , Pont Sebastian , Doust Alexander B. , Kwon Sooncheol , Fuller Patrick , Tan Ellasia , Durrant James R. , Kim Ji‐Seon
Published: January 2019

Controlling initial bulk‐heterojunction (BHJ) morphology of photoactive layer is critical for device efficiency of organic photovoltaic (OPV) cells. However, its impact on performance, specifically long‐term operational stability is still poorly understood. This is mainly due to limitations in direct measurements enabling in situ monitoring of devices at a molecular level. Here, a thermal annealing preconditioning step is utilized to tune initial morphology of model polymer:fullerene BHJ OPV devices and molecular resonant vibrational spectroscopy to identify in situ degradation pathways. Direct spectroscopic evidence is reported for molecular‐scale phase‐segregation temperature (TPS) which critically determines a boundary in high efficiency and long operational stability. Under operation, initially well‐mixed blend morphology (no annealing) shows interface instability related to the hole‐extracting layer via de‐doping. Likewise, initially phase‐segregated morphology at a molecular level (annealed above TPS) shows instability in the photoactive layer via continuous phase‐segregation between polymer and fullerenes in macroscales, coupled with further fullerene photodegradation. The results confirm that a thermal annealing preconditioning step is essential to stabilize the BHJ morphology; in particular annealing below TPS is critical for improved operational stability while maintaining high efficiency.
Improving Supercapacitance of Electrospun Carbon Nanofibers through Increasing Micropores and Microporous Surface Area
Authors: Wang He , Wang Wenyu , Wang Hongjie , Li Yeran , Jin Xin , Niu Haitao , Wang Hongxia , Zhou Hua , Lin Tong
Published: January 2019

Previous papers about electrospun carbon nanofibers do not provide systemic understandings about how in situ activation agents affect the porous structure of carbon nanofibers. In this study, poly(vinylpyrrolidone), poly(methyl methacrylate), and high‐amylose starch (HAS) are used as activation agent to separately prepare porous carbon nanofibers from electrospun polyacrylonitrile nanofibers, and the effects of the polymer activation agents on the porous structure and supercapacitive properties of the resulting carbon nanofibers are examined. The studies indicate that melting point and decomposition temperature are two important parameters deciding the pore size profile. The one with high melting point and low decomposition temperature, such as HAS, allows to form micropore‐dominant porous structure with large specific surface area. The HAS‐activated carbon nanofibers have a micropore specific surface area as high as ≈809 m2 g−1, total pore volume of ≈0.42 cm3 g−1, and micropore content as high as ≈59%. The corresponding electrodes have a capacitance of 282 F g−1 at the current density of 1.0 A g−1 with excellent cycling durability. These novel understandings may be useful for the development of effective carbon nanofibers for high‐performance supercapacitor and other applications.
Visible‐Light‐Mediated Stereoselective 1,2‐Iodoalkylation of Alkynes
Authors: Liu Jie‐Jie , Lan Ling , Gao Yu‐Ting , Liu Qi , Cheng Liang , Wang Dong , Liu Li
Published: January 2019

A visible‐light‐mediated and photocatalyst/initiator‐free addition to alkynes has been developed. An atom transfer radical addition (ATRA) mechanistic afforded a broad scope of valuable iodo‐substituted alkenyl derivatives with high E/Z‐selectivities, which are versatile intermediates for the synthesis of various tri‐ and tetra‐ substituted alkenes.

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Sandwich‐structured starch‐grafted polyethylhexylacrylate/polyvinyl alcohol thin films
Authors: Prusty Kalyani , Sethy Pramod K. , Swain Sarat K.
Published: January 2019

The present study aimed to explore the designing of nanoclay‐decorated polyethylhexylacrylate/polyvinyl alcohol clay (S‐g‐PEHA/PVA@clay) thin films. The thickness of the S‐g‐PEHA/PVA@clay thin films mainly depends on the polymerization of ethylhexylacrylate and concentrations of PVA. The presence of clay nanoparticles in S‐g‐PEHA/PVA thin films was confirmed by Fourier transform infrared spectroscopy, X‐ray diffraction, and energy‐dispersive X‐ray spectroscopy analyses. The field emission scanning electron microscopy images showed the presence of exfoliated nanoclay throughout the films. High‐resolution transmission electron microscopy was also performed to determine the degree of distribution and exfoliation of clay platelets. The surface and nano‐tribological characteristics of the thin films were investigated by atomic force microscopy. It was found that the exfoliation and intercalation of clay platelets in thin films depend on the concentration of Cloisite® 30B loading. The thermal conductivity, tensile strength, thermal properties, and refractive index were studied as a function of clay loading. It was noticed that tensile strength, thermal conductivity, thermal properties, and refractive index of the thin films were enhanced with the increase in Cloisite® 30B content due to the formation of an exfoliated and partially intercalated structure of the S‐g‐PEHA/PVA@clay. Chemical resistance and antibacterial and biodegradable properties of the thin films were also studied. The oxygen barrier property of the thin films was reduced fivefold due to the sandwich structure of clay platelets.
Fabrication of graphene oxide‐lead oxide epoxy based composite with enhanced chemical resistance, hydrophobicity and thermo‐mechanical properties
Authors: Abdollahifar Ali , Hashemi Seyyed Alireza , Mousavi Seyyed Mojtaba , Rahsepar Mansour , Amani Ali Mohammad
Published: January 2019

In this study, graphene oxide (GO) was synthesized using modified Hummer's method and thence GO's surface was decorated with Pb3O4 and active functional groups. Thereafter, composites containing GO‐Pb3O4 at diverse filler loadings were fabricated using vacuum shock technique. Successful synthesize of GO and GO‐Pb3O4 were confirmed using FTIR, EDAX, SEM, and PSA analyses, while developed composites subjected to chemical resistance and dynamic mechanical thermal analysis analyses to examine their resistance against chemical degradation and thermo‐mechanical performance, respectively. Achieved results showed that developed composites present fantastic resistance against solvents infiltration, chemical degradation, and crack propagation. Moreover, increase in the weight percentage of GO‐Pb3O4 to 10 wt% can lead to 0.9 kgf/mm2, 27.8°, and 53.23°C increase in the hardness, contact angle, and glass transition temperature compared with neat epoxy resin, respectively. This significant enhancement of developed composites is due to the strong interfacial connection and interaction between fillers and matrix.
A case of broken bones and systems: The threat of irresponsible testimony
Authors: Shur Natasha
Published: January 2019

A 2‐month‐old healthy baby presented to the emergency room with an arm that was not moving and was found to have multiple and extensive fractures of her long bones. An extensive medical work‐up was done, and the hospital's multidisciplinary child abuse team was consulted, including child protection, genetics, radiology, and general pediatrics. It was determined that the history, clinical findings, radiographic findings, and laboratory findings were consistent with child abuse. Child protection services removed the child from the home, and for the next 10 months, the infant was well, and did not sustain a single new fracture. At a civil proceeding to determine the infant's custody, an expert witness for the defense concluded that the child had hypermobile Ehlers‐Danlos syndrome and low vitamin D. He stated that because of these conditions, the baby was vulnerable to fractures with routine handling. This is a personal story of a clinical geneticist who explored fracture fact versus fracture fiction and learned about the difference between responsible and irresponsible testimony. This story gives insight into how physicians can prepare to transition from the clinic to the courtroom. It is also a story about how medical experts must and should remain unbiased, evidence‐based, and committed to accuracy and truth.
Local transgene expression and whole‐body transgenesis to model brain diseases in nonhuman primate
Authors: Chansel‐Debordeaux Lucie , Bezard Erwan
Published: January 2019

Animal model is an essential tool in the life sciences research, notably in understanding the pathogenesis of the diseases and for further therapeutic intervention success. Rodents have been the most frequently used animals to model human disease since the establishment of gene manipulation technique. However, they remain inadequate to fully mimic the pathophysiology of human brain disease, partially due to huge differences between rodents and humans in terms of anatomy, brain function, and social behaviors. Nonhuman primates are more suitable in translational perspective. Thus, genetically modified animals have been generated to investigate neurologic and psychiatric disorders. The classical transgenesis technique is not efficient in that model; so, viral vector‐mediated transgene delivery and the new genome‐editing technologies have been promoted. In this review, we summarize some of the technical progress in the generation of an ad hoc animal model of brain diseases by gene delivery and real transgenic nonhuman primate.
A Single‐Atom Nanozyme for Wound Disinfection Applications
Authors: Xu Bolong , Wang Hui , Wang Weiwei , Gao Lizeng , Li Shanshan , Pan Xueting , Wang Hongyu , Yang Hailong , Meng Xiangqin , Wu Qiuwen , Zheng Lirong , Chen Shenming , Shi Xinghua , Fan Kelong , Yan Xiyun , Liu Huiyu
Published: January 2019

Single‐atom catalysts (SACs), as homogeneous catalysts, have been widely explored for chemical catalysis. However, few studies focus on the applications of SACs in enzymatic catalysis. Herein, we report that a zinc‐based zeolitic‐imidazolate‐framework (ZIF‐8)‐derived carbon nanomaterial containing atomically dispersed zinc atoms can serve as a highly efficient single‐atom peroxidase mimic. To reveal its structure–activity relationship, the structural evolution of the single‐atom nanozyme (SAzyme) was systematically investigated. Furthermore, the coordinatively unsaturated active zinc sites and catalytic mechanism of the SAzyme are disclosed using density functional theory (DFT) calculations. The SAzyme, with high therapeutic effect and biosafety, shows great promises for wound antibacterial applications.
Auto‐Tandem Cooperative Catalysis Using Phosphine/Palladium: Reaction of Morita–Baylis–Hillman Carbonates and Allylic Alcohols
Authors: Chen Peng , Chen Zhi‐Chao , Li Yue , Ouyang Qin , Du Wei , Chen Ying‐Chun
Published: January 2019

Auto‐tandem catalysis (ATC), in which a single catalyst promotes two or more mechanistically different reactions in a cascade pattern, provides a powerful strategy to prepare complex products from simple starting materials. Reported here is an unprecedented auto‐tandem cooperative catalysis (ATCC) for Morita–Baylis–Hillman carbonates from isatins and allylic carbonates using a simple Pd(PPh3)4 precursor. Dissociated phosphine generates phosphorus ylides and the Pd leads to π‐allylpalladium complexes, and they undergo a γ‐regioselective allylic–allylic alkylation reaction. Importantly, a cascade intramolecular Heck‐type coupling proceeds to finally furnish spirooxindoles incorporating a 4‐methylene‐2‐cyclopentene motif. Experimental results indicate that both Pd and phosphine play crucial roles in the catalytic Heck reaction. In addition, the asymmetric versions with either a chiral phosphine or chiral auxiliary are explored, and moderate results are obtained.
Calculation of Nitrogen‐to‐Protein Conversion Factors: A Review with a Focus on Soy Protein
Authors: Krul Elaine S.
Published: January 2019

Protein content in foods and feeds is measured indirectly by nitrogen determination, requiring a nitrogen‐to‐protein conversion factor (NPCF). Historically, 6.25 was applied to all proteins based on two assumptions: (1) all proteins had a nitrogen content of 16% (100/16 = 6.25) and (2) all nitrogen was derived from protein. Amino acid analyses revealed that a conversion factor of 6.25 overestimated the protein content of most foods due to variations in amino acid profiles and nonprotein nitrogen. The lack of standardization of methods to determine food‐specific NPCF has resulted in continued use of 6.25 and inconsistent development of new factors. This review summarizes efforts made to derive NPCF for various foods. Soy protein has been the subject of considerable debate since publication of the “Jones factors” in 1931, which based the soy conversion factor of 5.71 on the nitrogen content of glycinin. Nonetheless, 6.25 is still used by the soy industry, analytic associations, and government regulatory bodies. Given the impact to the valuation of soy protein products and food relabeling costs, changes to soy alone appear discriminatory in the absence of standardized methods for developing NPCF for all proteins. Proposed solutions include (1) developing a consensus method to determine NPCF applicable to all foods, (2) applying standardized NPCF to measure protein in all foods and assessing the economic, nutritional, and regulatory consequences equitably, and (3) developing standardized direct methods to measure protein, such as amino acid analyses, in foods intended as single sources in vulnerable populations where more accurate measurement and reducing any risk of adulteration with nonprotein nitrogen are essential.
Effects of the biaxial orientation on the mechanical and optical properties and shrinkage of polyamide 6‐66–montmorillonite–nanosilica nanocomposite films
Authors: Liu Xiaochao , Liu Yuejun , Yang Jian , Wang Wenzhi , Lai Dengwang , Mao Long , Zheng Wei , Yang Jun , Chen Xi
Published: January 2019

Polyamide 6–66 (PA6‐66)–montmorillonite (MMT)–nanosilica (NS) nanocomposite films were fabricated through a cast film process and then biaxially stretched on a laboratory stretcher. Uniaxial or biaxial stretching induced the elongated conformation of MMT and NS. The b axis of the α crystals and the amorphous phase were revealed to align along the machine direction (MD) after stretching, with the uniaxial orientation playing a more significant role. Furthermore, the crystallinity of PA6‐66 stretching increased with the stretching ratio. Uniaxial stretching gave rise to a significantly enhanced tensile strength along the MD, whereas it slightly decreased the mechanical properties along the transverse direction (TD). In contrast, the films subjected to biaxial stretching exhibited more balanced mechanical properties. Uniaxial and biaxial stretching led to decreased transmittance and increased haze in the PA6‐66–MMT–NS films; this could have been due to the elongated nanostructure of the two nanofillers, which inhibited the transmission and facilitated the scattering of visible light. The thermal shrinkage of the films increased with increasing stretching ratio, and the biaxially oriented films presented nearly equal shrinkage in the MD and TD. The addition of nanofillers decreased the shrinkage attributed to the mobility inhibition of the polymer chains during heating. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47504.
Effect of the nanoparticles in the stability of hydrolyzed polyacrylamide/resorcinol/formaldehyde gel systems for water shut‐off/conformance control applications
Authors: Pérez‐Robles Saray , Cortés Farid B. , Franco Camilo A.
Published: January 2019

The main objective of this work is to evaluate the inclusion of nanoparticles to partially hydrolyzed polyacrylamide/resorcinol/formaldehyde gel systems to improve the stability under static and dynamic conditions. Oxide nanoparticles (<100 mg·L−1) of SiO2, Al2O3, MgO, and Cr2O3 were employed and characterized by their physicochemical properties. Gels were prepared and subsequently placed at 70 °C for evaluating the nanoparticles influence in gel strength through rheological properties and syneresis measurements. Al2O3 nanoparticles showed the highest potential for the reduction of the syneresis phenomena, followed by MgO and Cr2O3. The SiO2 nanoparticles lead to a higher degradation of the gel. As the zeta potential increases, the syneresis of the gel system decreases. The nanoparticles did not significantly affect the storage modulus, describing similar gel strength than the original gel. Also, displacement tests showed an incremental of 64% of oil recovery regarding the system in the absence of Al2O3 nanoparticles. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47568.
Development and characterization of genomic SSR markers for Tamarix chinensis (Tamaricaceae)
Authors: Zhang Ruhua , Wen Qiang , Xu Li‐an
Published: January 2019

Premise of the Study

We developed a set of microsatellite markers to study the population genetic structure, mating system, and interspecific hybridization of Tamarix chinensis (Tamaricaceae), an alkali‐ and salt‐tolerant shrub endemic to China, Korea, and Japan.

Methods and Results

Using Illumina sequencing, we developed 10 polymorphic and 11 monomorphic microsatellite primers. High levels of polymorphism were detected in four T. chinensis populations. Allele numbers ranged from two to 11, and the levels of observed and expected heterozygosity ranged from 0.182 to 0.846 and from 0.165 to 0.794, respectively. The polymorphism information content values ranged from 0.201 to 0.803. Cross‐species amplification showed two to 15 alleles per locus in 24 individuals from one natural population of the congener T. ramosissima, and the levels of observed and expected heterozygosity ranged from 0.042 to 0.864 and from 0.041 to 0.892, respectively.

Conclusions

These markers should be useful for exploring the population genetic structure, mating system, and gene flow of T. chinensis.
The Benefits of an Augmented Reality Magic Mirror System for Integrated Radiology Teaching in Gross Anatomy
Authors: Bork Felix , Stratmann Leonard , Enssle Stefan , Eck Ulrich , Navab Nassir , Waschke Jens , Kugelmann Daniela
Published: January 2019

Early exposure to radiological cross‐section images during introductory anatomy and dissection courses increases students’ understanding of both anatomy and radiology. Novel technologies such as augmented reality (AR) offer unique advantages for an interactive and hands‐on integration with the student at the center of the learning experience. In this article, the benefits of a previously proposed AR Magic Mirror system are compared to the Anatomage, a virtual dissection table as a system for combined anatomy and radiology teaching during a two‐semester gross anatomy course with 749 first‐year medical students, as well as a follow‐up elective course with 72 students. During the former, students worked with both systems in dedicated tutorial sessions which accompanied the anatomy lectures and provided survey‐based feedback. In the elective course, participants were assigned to three groups and underwent a self‐directed learning session using either Anatomage, Magic Mirror, or traditional radiology atlases. A pre‐ and posttest design with multiple choice questions revealed significant improvements in test scores between the two tests for both the Magic Mirror and the group using radiology atlases, while no significant differences in test scores were recorded for the Anatomage group. Furthermore, especially students with low mental rotation test (MRT) scores benefited from the Magic Mirror and Anatomage and achieved significantly higher posttest scores compared to students with a low MRT score in the theory group. Overall, the results provide supporting evidence that the Magic Mirror system achieves comparable results in terms of learning outcome to established anatomy learning tools such as Anatomage and radiology atlases.
Computational phantom study of frozen melanoma imaging at 0.45 terahertz
Authors: Vilagosh Zoltan , Lajevardipour Alireza , Wood Andrew W.
Published: January 2019

Terahertz radiation (THz) is highly absorbed by liquid water. This creates the possibility of medical imaging on the basis of the water content difference between normal and diseased tissue. The effective penetration of THz is limited, however, to a tissue depth of 0.2–0.3 mm at body temperature. A unique feature of the 0.1–2.0 THz frequency is that there is a high disparity between liquid water absorption and ice absorption, with ice being 100 times more permeable to the radiation than liquid water. This results in 90% of the radiation surviving to 1.0 mm in ice, permitting the imaging of frozen tissues to a depth of 5.0 mm. This method is practical as an in vivo procedure before or during surgical excision. Finite difference time domain (FDTD) computational modeling of frozen normal skin and frozen melanoma was undertaken using tissue phantoms. The study suggests that sufficient contrast exists to differentiate normal frozen skin and melanoma on the basis of the difference of water content alone. When the melanin pigment in melanomas is modeled as a significant absorber of THz, the contrast changes. Based on the modeling, further exploration of the “THz‐skin freeze” imaging technique is justified. In the modeling, the boundary between the frozen tissue and non‐frozen tissue is shown to be strongly reflective. If the reflective properties of the boundary are substantiated, the “THz‐skin freeze” technique will have applications in other areas of skin diagnostics and therapeutics. Bioelectromagnetics. 40:118–127, 2019. © 2019 Bioelectromagnetics Society
Attenuated levels of ghrelin in synovial fluid is related to the disease severity of ankle post‐traumatic osteoarthritis
Authors: Zou Yu‐Cong , Li Hai‐Hong , Yang Guang‐Gang , Yin Hai‐Dong , Cai Dao‐Zhang , Liu Gang
Published: January 2019

Post‐traumatic osteoarthritis (PTOA) of ankle joints results in pain and reduced joint function. Ghrelin, a 28‐amino‐acid polypeptide, has been previously identified as the first cognate natural ligand that binds to the growth hormone secretagogue receptor. In the present study, ghrelin has been validated to exert cartilage‐protective and anti‐inflammatory effects. The current study was aimed at investigating the potential role of the levels of serum and synovial fluid (SF) ghrelin on the severity of disease in patients suffering from ankle PTOA. Ninety‐seven patients with ankle osteoarthritis who received an arthroscopical examination and debridement or replacement of the ankle joint were included in the study cohort. Meanwhile, 95 healthy individuals (whose age and sex were matched) who received periodic body checkups were enrolled as healthy controls. Enzyme‐linked immunosorbent assay (ELISA) was used to analyze the ghrelin levels in serum and SF. SF was also probed for cartilage degradation enzyme matrix metalloproteinases‐3 (MMP‐3) and tumor necrosis factor alpha (TNF‐α), which is a known pro‐inflammatory cytokine. The clinical evaluation was carried out using the American Orthopedic Foot and Ankle Society (AOFAS) ankle‐hindfoot rating scale and visual analogue scale (VAS). The radiographic severity was evaluated using the modified Kellgren–Lawrence (K–L) grading system. We scored for the modified Mankin's score to depict histopathological changes due to cartilage lesions. The diagnostic relevance of the ghrelin concentrations in the prediction of the radiographic grading (in comparison with MMP‐3 and TNF‐α) was evaluated by calculating the area under the curve of the receiver operating characteristic (ROC) curve. The serum abundance of ghrelin was not significantly altered between ankle PTOA patients and healthy controls. SF ghrelin was negatively correlated with radiographic progression determined by modified ankle K–L grades. In addition SF ghrelin concentrations were negatively related to VAS scores, and positively associated with AOFAS ankle‐hindfoot rating. Moreover, SF ghrelin was inversely proportional to the expressions of MMP‐3 and TNF‐α. ROC analysis curve demonstrated that ghrelin serves as a favorable marker for the diagnosis of radiographic severity by modified ankle K‐L grade. The ghrelin concentration in SF is negatively proportional to disease progression in patients suffering from ankle PTOA. Local administration of ghrelin may function as a decent adjuvant therapy to delay the progress of ankle PTOA. © 2019 BioFactors, 45(3):463–470, 2019
Determination of bisphenol A in red wine using a double vortex–ultrasound‐assisted microextraction assay: Role of the interfacial properties
Authors: Cinelli Giuseppe , Cuomo Francesca , Ambrosone Luigi , Venditti Francesco , Lopez Francesco
Published: January 2019

Bisphenol A (BPA) is a synthetic compound broadly used in medical devices as well as in packaging of food and drinks. Recently, BPA toxicity has become of concern to environmental public health. Red wine that is susceptible to BPA contamination is an alcoholic beverage made from yeast fermentation of grapes in the presence of grape skins so as to extract phenolic compounds. The aim of this study was to validate an efficient, low cost, and time‐saving method for BPA determination in red‐wine beverage. To this end, a rapid and simple microextraction method is here proposed consisting in liquid–liquid separation assisted by a vortex–ultrasound–vortex procedure combined with gas chromatographic analysis (GC‐Fid or GC‐IT/MS). By means of a comparative study between real red‐wine matrix and synthetic hydroalcoholic solutions, different parameters related to the microextraction steps were investigated. The minimal amount of extraction solvent for a given volume of sample was calculated for both the systems. It was demonstrated that for red‐wine matrix, the extent of phase separation is strongly affected by some wine constituents and that separation can be tuned by varying the amount of the extraction solvent. This double vortex–ultrasound‐assisted method achieved high recovery of BPA and enrichment factor compared with other microextraction methods.
Chronic ventricular lead perforation: Expect the unexpected
Authors: Sidhu Baldeep S. , Rajani Ronak , Rinaldi Christopher A.
Published: January 2019

Key Clinical Message

A high index of suspicion is needed to diagnose a chronic right ventricular lead perforation. They should be suspected in patients who develop breathlessness and have a sudden change in pacing parameters. Contrast‐enhanced CT provides high diagnostic accuracy. They can often be extracted percutaneously and rarely require surgical intervention.