bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of changing ocean circulation on the distribution of marine microplastic litter
Authors: Welden Natalie AC , Lusher Amy L
Published: April 2017

Marine plastic pollution is currently a major scientific focus, with attention paid to its distribution and impacts within ecosystems. With recent estimates indicating that the mass of plastic released to the marine environment may reach 250 million metric tons by 2025, the effects of plastic on our oceans are set to increase. Distribution of microplastics, those plastics measuring less than 5 mm, are of increasing concern because they represent an increasing proportion of marine litter and are known to interact with species in a range of marine habitats. The local abundance of microplastic is dependent on a complex interaction between the scale of local plastic sources and prevailing environmental conditions; as a result, microplastic distribution is highly heterogeneous. Circulation models have been used to predict plastic distribution; however, current models do not consider future variation in circulation patterns and weather systems caused by a changing climate. In this study, we discuss the potential impacts of global climate change on the abundance and distribution of marine plastic pollution. Integr Environ Assess Manag 2017;13:483–487. © 2017 SETAC

Key Points

Microplastic distribution may be greatly altered by global climate change. Incorporating predicted changes into models of plastic transport may enable the prediction of at-risk habitats.
Menstrual and reproductive factors and lung cancer risk: A pooled analysis from the international lung cancer consortium
Authors: Ben Khedher Soumaya , Neri Monica , Papadopoulos Alexandra , Christiani David C. , Diao Nancy , Harris Curtis C , Olivo‐Marston Susan , Schwartz Ann G. , Cote Michele , Koushik Anita , Siemiatycki Jack , Landi Maria Teresa , Hung Rayjean J. , McLaughlin John , Duell Eric J , Andrew Angeline S. , Orlow Irene , Park Bernard J. , Brenner Hermann , Saum Kai‐Uwe , Pesatori Angela C. , Stücker Isabelle
Published: April 2017

Many clinical features of lung cancer are different in women and men. Sex steroid hormones exert effects in nonreproductive organs, such as the lungs. The association between menstrual and childbearing factors and the risk of lung cancer among women is still debated. We performed a pooled analysis of eight studies contributing to the International Lung Cancer Consortium (4,386 cases and 4,177 controls). Pooled associations between menstrual or reproductive factors and lung cancer were estimated using multivariable unconditional logistic regression. Subgroup analyses were done for menopause status, smoking habits and histology. We found no strong support for an association of age at menarche and at menopause with lung cancer, but peri/postmenopausal women were at higher risk compared to premenopausal (OR 1.47, 95% CI 1.11–1.93). Premenopausal women showed increased risks associated with parity (OR 1.74, 95% CI 1.03–2.93) and number of children (OR 2.88, 95% CI 1.21–6.93 for more than 3 children; p for trend 0.01) and decreased with breastfeeding (OR 0.54, 95% CI 0.30–0.98). In contrast, peri/postmenopausal subjects had ORs around unity for the same exposures. No major effect modification was exerted by smoking status or cancer histology. Menstrual and reproductive factors may play a role in the genesis of lung cancer, yet the mechanisms are unclear, and smoking remains the most important modifiable risk factor. More investigations in large well‐designed studies are needed to confirm these findings and to clarify the underlying mechanisms of gender differences in lung cancer risk.
What drives differences of opinion in sovereign ratings? The roles of information disclosure and political risk
Authors: Vu Huong , Alsakka Rasha , ap Gwilym Owain
Published: April 2017

This paper investigates the causes of split sovereign ratings across S&P, Moody's, and Fitch for 64 countries from 1997 to 2011. We identify that split sovereign ratings are not symmetric, with S&P tending to be the most conservative agency. We find that opaque sovereigns are more likely to receive split ratings. Political risk plays a highly significant role in explaining split ratings and dominates economic and financial indicators. Out‐of‐sample model performance is enhanced by capturing political risk. Government information disclosure affects split ratings between Moody's and Fitch in emerging countries. The study implies an incentive for governments to reduce political uncertainty and to enhance transparency.
Construction and validation of the Sport Sense of Community in Adolescence Questionnaire (SSCAQ)
Authors: Scotto di Luzio Silvia , Guillet‐Descas Emma , Procentese Fortuna , Martinent Guillaume
Published: April 2017

The purpose of the present study was to develop and psychometrically evaluate a measure of sport sense of community (SoC) for adolescents grounded in McMillan and Chavis’ framework: the Sport Sense of Community in Adolescence Questionnaire (SSCAQ). A calibration sample of 256 and a validation sample of 257 adolescent athletes voluntarily participated in the study. Data were analyzed pertaining to reliability, confirmatory factor analyses (CFAs), and multigroup CFAs as well as with correlational analyses. Results showed that the 5‐factor, 19‐item hierarchical model of the SSCAQ fit the data adequately on the calibration and validation samples. Multigroup CFAs showed that the SSCAQ scores were invariant across sex of the participants and type of sport (individual versus team sports). Furthermore, both convergent and discriminant validity of the SSCAQ scores were established by finding interrelations between perceived autonomy support from the coach, future sport intentions, and the SSCAQ subscales. The SSCAQ is a measure that will be useful for research on sport SoC.
An Efficient One‐Pot Three‐Component Synthesis of Some New Polyhydroquinolines via Enaminone Intermediates
Authors: Abdelhamid Antar A. , Abd Allah Omyma A. , Tamam Asmaa H.A.
Published: April 2017

For a wide spectrum of pharmacological effects of polyhydroquinolines, this study introduces a developed safe, simple, higher yields and fast method for the synthesis of some new hexahydroquinoline derivatives using one‐pot three‐component cyclocondensation reaction, via the reaction of 1,3‐cyclohexanedione with primary amine and arylidinemalononitrile or salicylaldehyde derivatives. The prepared compounds were reacted with different reagents as N,N‐dimethylformamide dimethylacetal, acetic anhydride, sulphuric acid, and hydrazine hydrate forming several polycyclic hexahydroquinoline and acridine derivatives. All these new compounds have been characterized by spectral data and expected to be effective pharmaceutical drugs.
Evaluation of column length and particle size effect on the untargeted profiling of a phytochemical mixture by using UHPLC coupled to high‐resolution mass spectrometry
Authors: Zenezini Chiozzi Riccardo , Capriotti Anna Laura , Cavaliere Chiara , Ferraris Francesca , La Barbera Giorgia , Piovesana Susy , Laganà Aldo
Published: April 2017

Liquid chromatography coupled to high‐resolution mass spectrometry is the technique of choice for the untargeted profiling of food matrices. Despite the high potential of high‐resolution mass spectrometry, when dealing with complex mixtures, an efficient separation technique is also needed. The novel core‐shell chromatographic columns packed with sub‐2 μm sized particles are claimed to show very good resolution. However, the analytes retention can be significantly altered when working under ultra‐high performance chromatographic conditions. In this work, an evaluation of four chromatographic systems, with either a single or two in‐series Kinetex™ C18 columns, either packed with 2.6 or 1.7 μm particles, is presented for the targeted analysis of a standard mixture and the untargeted analysis of a strawberry extract. An ultra‐high performance chromatographic system coupled via an electrospray source to a hybrid quadrupole‐Orbitrap mass spectrometer was used. From the extensive comparison, a surprising result was obtained, namely, that the system identifying the largest number of features was the one with two in‐series connected columns with the larger particle size. The inconsistency among the theoretical assumptions and the applicative findings points out the importance of an extensive chromatographic evaluation for the comprehensive untargeted profiling of complex real samples.
Landscape capability predicts upland game bird abundance and occurrence
Authors: Loman Zachary G. , Blomberg Erik J. , Deluca William V. , Harrison Daniel J. , Loftin Cynthia S. , Wood Petra B.
Published: April 2017

Landscape capability (LC) models are a spatial tool with potential applications in conservation planning. We used survey data to validate LC models as predictors of occurrence and abundance at broad and fine scales for American woodcock (Scolopax minor) and ruffed grouse (Bonasa umbellus). Landscape capability models were reliable predictors of occurrence but were less indicative of relative abundance at route (11.5–14.6 km) and point scales (0.5–1 km). As predictors of occurrence, LC models had high sensitivity (0.71–0.93) and were accurate (0.71–0.88) and precise (0.88 and 0.92 for woodcock and grouse, respectively). Models did not predict point‐scale abundance independent of the ability to predict occurrence of either species. The LC models are useful predictors of patterns of occurrences in the northeastern United States, but they have limited utility as predictors of fine‐scale or route‐specific abundances. © 2017 The Wildlife Society.
Flowpath and retention of snowmelt in an ice‐covered arctic lake
Authors: Cortés Alicia , MacIntyre Sally , Sadro Steven
Published: April 2017

The extent to which snowmelt flowing into ice‐covered lakes spreads horizontally and mixes vertically influences retention of solutes derived from the landscape. To quantify these transport processes and retention, we combine time series temperature and specific conductance measurements in Toolik Lake (Alaska) and its major inflow, with measurements of discharge and meteorology, and profiles of specific conductance, temperature, fluorescence, chlorophyll a, and dissolved organic carbon (DOC) in spring of 3 yr. During early snowmelt, the concentration of DOC in the stream was 750 μM, twice that in the lake. During slow melt (discharge (Q) < 4 m3 s−1), the incoming solute‐rich intrusion spread lakewide below the ice. During melt with Q > 6 m3 s−1, the incoming water partially flushed the inlet basin and the more dilute water flowed over the original intrusion with a preferential flowpath to the outlet. Penetrative convection was restricted by the increased density gradients from the incoming plume and initially constrained to shallow mixing zones associated with the step changes in density. As ice thickness decreased to less than 1 m, heating caused density instabilities at the base of the intrusions that mixed solutes ∼ 10 m vertically, contributing to retention. Near‐surface layers enriched with DOC persisted for ∼ 10 d during a rapid melt and for over 3 weeks when the melt was slow. Retention, of order 10–20%, also depended on the rapidity of melt and magnitude of discharge.
Interfacial reaction between SAC305 lead–free solders and ENImAg surface finish and bare copper
Authors: Adawiyah M.A. Rabiatul , Azlina O. Saliza
Published: April 2017

Different surface finishes on printed circuit board strongly influence the formation of intermetallic compounds (IMCs), and solder joint reliability. In this paper the effect of two different substrates namely electroless nickel/immersion silver (ENImAg) and bare copper on interfacial reaction when exposed to a reflow soldering process are presented. The result revealed that the black line nickel disappeared on the electroless nickel/immersion silver surface finish after the plating process. Subsequently, the intermetallic compound formed on electroless nickel/immersion silver surface finish are (Cu,Ni)6Sn5, and (Ni,Cu)3Sn4 with a chuck‐shape, rode‐type, and needle‐shape after reflow soldering. Meanwhile, only Cu6Sn5 layer is found on bare copper with a spherical‐shape. The results also indicated that different surface finishes are affected by the growth of intermetallic formation and shear strength, where tin‐3.0silver‐copper0.5/copper (SAC305/Cu) produced a thicker intermetallic layer, larger grain size, and less shear strength compared with tin‐3.0silver‐copper0.5/electroless nickel immersion silver (SAC305/ENImAg) surface finish.
Numerical simulation of two–phase separation in a small diameter ratio T‐junction
Authors: Pao W. , Saieed A. , Hashim F. M. , Norpiah R. B. M.
Published: April 2017

The utilization of T‐junctions for flow division is quite common in industries. Due to the phenomena known as multiphase maldistribution, occurring in a T‐junction, they are often used as partial phase separators for reducing the work load on phase separation devices in oil and gas platforms. Previous literature says that reducing the diameter ratio of the T‐junction improves the two‐phase separation, however it was also reported that reducing the diameter ratio too much has a negative effect on two‐phase separation. To test this, a numerical study was performed to see the two‐phase stratified flow separation in 1, 0.6 and 0.167 diameter ratio T‐junctions. Furthermore, the impact of air superficial velocity on phase maldistribution at the junction is also considered. The T‐junctions with diameter ratios 1 and 0.6 were just used for the validation of present model, by comparing the obtained numerical results with previous experimental data. While, 0.167 diameter ratio T‐junction is the one for which the actual analysis was performed. It is concluded that an increase in air superficial velocity aids liquid carryover, whereas liquid carryover is very sensitive to side arm extraction rates in a very small diameter ratio T‐junction.
Integral representation and estimation of harmonic functions in the quaternionic half space
Authors: Zhang Yan Hui , Kou Kit Ian
Published: April 2017

In this article, we discuss the integral representation of quaternionic harmonic functions in the half space with the general boundary condition. Next, we derive a lower bound from an upper one for quaternionic harmonic functions. These results generalize some of the classic results from the case of plane to the case of noncommutative quaterninionic half space. Copyright © 2017 John Wiley & Sons, Ltd.
Dynamics of virus infection models with density‐dependent diffusion and Beddington–DeAngelis functional response
Authors: Wang Shaoli , Zhang Jiafang , Xu Fei , Song Xinyu
Published: April 2017

In this work, we integrate both density‐dependent diffusion process and Beddington–DeAngelis functional response into virus infection models to consider their combined effects on viral infection and its control. We perform global analysis by constructing Lyapunov functions and prove that the system is well posed. We investigated the viral dynamics for scenarios of single‐strain and multi‐strain viruses and find that, for the multi‐strain model, if the basic reproduction number for all viral strains is greater than 1, then each strain persists in the host. Our investigation indicates that treating a patient using only a single type of therapy may cause competitive exclusion, which is disadvantageous to the patient's health. For patients infected with several viral strains, the combination of several therapies is a better choice. Copyright © 2017 John Wiley & Sons, Ltd.
Effects of time integration schemes on discontinuous deformation simulations using the numerical manifold method
Authors: Qu Xiaolei , Qi Chengzhi , Fu Guoyang , Li Xiaozhao
Published: April 2017

Numerical stability by using certain time integration scheme is a critical issue for accurate simulation of discontinuous deformations of solids. To investigate the effects of the time integration schemes on the numerical stability of the numerical manifold method, the implicit time integration schemes, ie, the Newmark, the HHT‐α, and the WBZ‐α methods, and the explicit time integration algorithms, ie, the central difference, the Zhai's, and Chung‐Lee methods, are implemented. Their performance is examined by conducting transient response analysis of an elastic strip subjected to constant loading, impact analysis of an elastic rod with an initial velocity, and excavation analysis of jointed rock masses, respectively. Parametric studies using different time steps are conducted for different time integration algorithms, and the convergence efficiency of the open‐close iterations for the contact problems is also investigated. It is proved that the Hilber‐Hughes‐Taylor‐α (HHT‐α), Wood‐Bossak‐Zienkiewicz‐α (WBZ‐α), Zhai's, and Chung‐Lee methods are more attractive in solving discontinuous deformation problems involving nonlinear contacts. It is also found that the examined explicit algorithms showed higher computational efficiency compared to those implicit algorithms within acceptable computational accuracy.
Characterization of the anti‐CD22 targeted therapy, moxetumomab pasudotox, for B‐cell precursor acute lymphoblastic leukemia
Authors: Kinjyo Ichiko , Matlawska‐Wasowska Ksenia , Chen Xiaoru , Monks Noel R. , Burke Patricia , Winter Stuart S. , Wilson Bridget S.
Published: April 2017

Moxetumomab pasudotox is a second‐generation recombinant immunotoxin against CD22 on B‐cell lineages. Antileukemic activity has been demonstrated in children with chemotherapy‐refractory B‐cell precursor acute lymphoblastic leukemia (BCP‐ALL), with variable responses. Here, we report in vitro and in vivo evaluation of moxetumomab pasudotox treatment of human cell lines and patient‐derived cells as a preliminary study to understand characteristics of sensitivity to treatment. Binding, internalization, and apoptosis were evaluated using fluorescently tagged moxetumomab pasudotox. Studies in NOD‐scid IL2Rgnull mice showed a modest survival benefit in mice engrafted with 697 cells but not in NALM6 or the two patient‐derived xenograft models.
How do Personality and Social Structures Interact with Each other to Predict Important Life Outcomes? The Importance of Accounting for Personality Change
Authors: Boyce Christopher J. , Wood Alex M. , Delaney Liam , Ferguson Eammon
Published: April 2017

Personality is important for a range of life outcomes. However, despite evidence that personality changes across time, there is a concerning tendency for researchers outside of personality psychology to treat measures of personality as if they are non–changing when establishing whether personality predicts important life outcomes. This is problematic when personality changes in response to outcomes of interest and creates a methodological issue that may result in misleading conclusions. We illustrate this methodological issue and suggest using measures before the outcome takes place to mitigate concerns. We then demonstrate, using data from Germany, that using post–event personality measures, as opposed to pre–outcome measures, to predict both occurrence of, and reactions to, socio–economic events results in inconsistent conclusions in the directions hypothesized and therefore increases the likelihood of Type 1 and Type 2 errors. This has implications for research investigating the importance of personality for psychological, behavioural, and socio–economic outcomes. Copyright © 2017 European Association of Personality Psychology
Quantitative proteomic analysis of EZH2 inhibition in acute myeloid leukemia reveals the targets and pathways that precede the induction of cell death
Authors: Sandow Jarrod J. , Infusini Giuseppe , Holik Aliaksei Z. , Brumatti Gabriela , Averink Tessa V. , Ekert Paul G. , Webb Andrew I.
Published: April 2017

Purpose

Chromosomal translocation of the mixed lineage leukemia (MLL) locus generates fusion proteins that drive acute myeloid leukemia (AML) resulting in atypical histone methyltransferase activity and alterations in the epigenetic regulation of gene expression. Targeting histone regulators, such as Enhancer of Zeste Homologue 2 (EZH2), has shown promise in AML. Profiling differential protein expression following inhibition of epigenetic regulators in AML may help to identify novel targets for therapeutics.

Experimental design

Murine models of AML combined with quantitative SILAC analysis were used to identify differentially expressed proteins following inhibition of EZH2 activity using 3‐Deazaneplanocin A (DZnep). Western blotting and flow cytometry were used to validate a subset of differentially expressed proteins. Gene set analysis was used to determine changes to reported EZH2 target genes.

Results

Our quantitative proteomic analysis and subsequent validation of protein changes identified that epigenetic therapy leads to cell death preceded by the induction of differentiation with concurrent p53 up‐regulation and cell cycle arrest. Gene set analysis revealed a specific subset of EZH2 target genes that were regulated by DZnep in AML.

Conclusion and clinical relevance

These discoveries highlight how this new class of drugs affects AML cell biology and cell survival, and may help identify novel targets and strategies to increase treatment efficacy.
Discovery of LHRH and development of LHRH analogs for prostate cancer treatment
Authors: Schally Andrew V. , Block Norman L. , Rick Ferenc G.
Published: April 2017

The discovery, isolation, elucidation of structure, synthesis, and initial testing of the neuropeptide hypothalamic luteinizing hormone‐releasing hormone (LHRH), which regulates reproduction, is briefly described. The design, synthesis, and experimental and clinical testing of agonistic analogs of LHRH is extensively reviewed focusing on the development of new methods for the treatment of prostate cancer. Subsequent development of antagonistic analogs of LHRH is then faithfully recounted with special emphasis on therapy of prostate cancer and BPH. The concepts of targeted therapy to peptide receptors on tumors are re‐examined and the development of the cytotoxic analogs of LHRH and their status is reviewed. The endeavor to develop better therapies for prostate cancer, based on LHRH analogs, guided much of our work.
Pressure‐induced polyamorphism in lanthanide‐solute metallic glasses
Authors: Li Liangliang , Wang Luhong , Li Renfeng , Qu Dongdong , Zhao Haiyan , Chapman Karena W. , Chupas Peter J. , Liu Haozhe
Published: April 2017

The electronic structure inheritance of lanthanide‐solvent atoms in lanthanide‐based metallic glasses has been proposed. Is a polyamorphism possible in lanthanide‐solute metallic glasses? So far, polyamorphic phase transitions in metallic glass containing lanthanide have been observed only in lanthanide‐solvent metallic glasses. Here, a pressure‐induced transition between two distinct amorphous states, accompanied by a 7% volume collapse at ambient pressure, was observed in La43.4Pr18.6Al14Cu24 metallic glass, with low lanthanide content, by using in situ X‐ray total scattering method. The transformation also indicated by changes in short range and medium range order. Thus, it is proposed that the lanthanide‐solute metallic glasses also inherit 4f electronic transition from pure lanthanide element in polyamorphic transition. This discovery offers a supplement to research on lanthanide‐based metallic glasses, which further provides a new perspective of the polyamorphic transformation in metallic glasses containing lanthanide element.
The effects of chosen plant extracts and compounds on mesenchymal stem cells—a bridge between molecular nutrition and regenerative medicine‐ concise review
Authors: Kornicka Katarzyna , Kocherova Ievgeniia , Marycz Krzysztof
Published: April 2017

Mesenchymal stem cells (MSC) stand as a promising tool in regenerative medicine because of their high therapeutic potential in treatment of degenerative, metabolic and other types of diseases. The cellular therapies involving MSCs include their isolation mainly from the bone marrow, adipose tissue or umbilical cord and in vitro expansion for further autologous or allogeneic transplantation. Recent studies revealed, that bioactive compounds, naturally occurring in seaweeds, herbs, fruits and vegetables, possess the ability to modulate self‐renewal and differentiation potential of adult stem cells, targeting a broad range of intracellular signal transduction pathways. Number of ongoing trials aim to find a herbal extract that may become less toxic and affordable natural therapeutic. Mesenchymal stem cells are treated with crude extracts or individual compounds to investigate its effects and mechanism on stem cells proliferation and differentiation. Deeply investigated, herbal extract which increases tissue regeneration and promotes stem cell growth may be successfully applied in the field of biomaterials. Promoting the endogenous stem cell multipotency and their differentiation potential may additionally support the regenerative processes after MSCs transplantation. The review focuses on the beneficial effects of chosen plant derived substances on MSCs proliferative activity and their osteogenic differentiation potential. Copyright © 2017 John Wiley & Sons, Ltd.
A single‐molecule reaction cascade: First‐principles molecular dynamics simulation
Authors: Frank Irmgard
Published: April 2017

The success of mechanochemistry is continued with the targeted organic synthesis of functional nano‐scale devices. In the present theoretical study, first principles molecular dynamics simulations are performed for a recently synthesized three‐ring system that functions as a molecular reaction cascade. Mechanochemical and photochemical reaction conditions are investigated. The system was designed in a way that three bonds would break consecutively in mechanochemical and sonochemical setups. We succeeded to simulate the reaction mechanisms with first‐principles molecular dynamics simulations and discuss the stereochemistry.
Immunosuppressive drugs in whole blood: validation of a commercially available liquid chromatography/tandem mass spectrometry kit and comparison with immunochemical assays
Authors: Polledri Elisa , Mercadante Rosa , Ferraris Fusarini Chiara , Maiavacca Rita , Fustinoni Silvia
Published: April 2017

Rationale

In the determination of immunosuppressive drugs cyclosporine A (CSA), tacrolimus (TARO), sirolimus (SIRO), and everolimus (EVE) in whole blood there is an open debate about which is the best assay between immunochemistry and liquid chromatography/tandem mass spectrometry (LC/MS/MS). This work is aimed to explore this topic, focusing on the use of updated assays and the analysis of a large number of samples.

Methods

A certified in vitro diagnostic kit coupled with a medical device LC/MS/MS was validated and applied to the analysis of 1192 blood samples of patients treated with immunosuppressive drugs. The results were compared with those obtained by immunoassays.

Results

The LC/MS/MS approach was found to provide linear, stable, precise, and accurate results, with lower limits of quantification of 12.5, 1.1, 1.2, and 1.2 μg/L for CSA, TACRO, SIRO, and EVE, respectively. With this method 80 samples were analysed and reported within a single work shift. A correlation was observed between the LC/MS/MS and immunoassay data, with Spearman correlation coefficients of 0.980 (n = 260) for CSA, 0.836 for TACRO (n = 562), 0.898 for SIRO (n = 113), and 0.904 for EVE (n = 257). Passing‐Bablock regression showed the presence of constant and proportional biases for most of the drugs. A Blond‐Altman graph showed differences between the assays, with immunoassays generally overestimating the drugs.

Conclusions

The LC/MS/MS certified kit was validated for the detection of immunosuppressant drugs in whole blood and it provided a high‐throughput method that is consistent with the requirements of clinical laboratories. The comparison of patient data between LC/MS/MS and up‐dated immunoassays shows that a significant discrepancy still exists, especially for CSA and SIRO, confirming the greater specificity associated with use of the LC/MS/MS assay Copyright © 2017 John Wiley & Sons, Ltd.
Synthesis and Characterization of Graphene like Carbon Nanosheet: Interaction with some Drug Molecules and Anticancer Activity
Authors: Chattopadhyay Asoke P. , Mandal Prasenjit , Sarkar Rajkumar , Samadder Asmita , Khuda‐Bukhsh Anisur R. , Yadav Priya , Sarkar Keka
Published: April 2017

Graphene‐like carbon nano‐sheets are prepared from dextrin, with cetyltrimethyl ammonium bromide (CTAB) as stabiliser, by the action of concentrated sulfuric acid. Oxidation of such sheets produce graphene oxide (GO) like material. These are characterized in the usual manner and their photophysical properties are explored. Binding of certain drug molecules with carbon nano‐sheet is investigated fluorimetrically. Finally, action of carbon nano‐sheets on normal and cancer cell lines revealed that the sheets have no effect on normal cells, but induce apoptosis on cancer cells. Also, these carbon nano‐sheets behave very similar to reduced graphene oxide platelets.
Synthetic plant virology for nanobiotechnology and nanomedicine
Authors: Steele John F. C. , Peyret Hadrien , Saunders Keith , Castells‐Graells Roger , Marsian Johanna , Meshcheriakova Yulia , Lomonossoff George P.
Published: April 2017

Nanotechnology is a rapidly expanding field seeking to utilize nano‐scale structures for a wide range of applications. Biologically derived nanostructures, such as viruses and virus‐like particles (VLPs), provide excellent platforms for functionalization due to their physical and chemical properties. Plant viruses, and VLPs derived from them, have been used extensively in biotechnology. They have been characterized in detail over several decades and have desirable properties including high yields, robustness, and ease of purification. Through modifications to viral surfaces, either interior or exterior, plant‐virus‐derived nanoparticles have been shown to support a range of functions of potential interest to medicine and nano‐technology. In this review we highlight recent and influential achievements in the use of plant virus particles as vehicles for diverse functions: from delivery of anticancer compounds, to targeted bioimaging, vaccine production to nanowire formation. WIREs Nanomed Nanobiotechnol 2017, 9:e1447. doi: 10.1002/wnan.1447

This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging

Biology-Inspired Nanomaterials > Protein and Virus-Based Structures
The Paris Commune
Authors: Shafer David A.
Published: April 2017

Photographs are used as documents, evidence, and records every day in courtrooms, hospitals, and police work, on passports, permits, and licenses. But how did such usages come to be established and accepted, and when? What kinds of photographs were seen seen as purely instrumental and able to function in this way? What sorts of agencies and institutions had the power to give them this status? And more generally, what conception of photographic representation did this involve, and what were its consequences?
Cues to individual identity in songs of songbirds: testing general song characteristics in Chiffchaffs Phylloscopus collybita
Authors: Průchová Alexandra , Jaška Pavel , Linhart Pavel
Published: April 2017

Individual variation in vocalizations has been widely studied among different animal taxa, and it is commonly reported that vocalizations could be potentially used to monitor individuals in many species. Songbirds represent a challenging group of animals for the study of signalling of individual identity. They are highly vocal, but their songs are complex and can change over time. In this study, we tested whether general song characteristics, which are independent of song type, can be used to discriminate and consistently identify Chiffchaff males within and between days and between years. There was individual variation in songs of recorded Chiffchaffs, and it was possible to easily discriminate between males at any one point in time. However, the level of re-identification of males across days and years was low. For effective identification it was necessary to compare songs of a single song type. However, Chiffchaffs haphazardly switch among song types, sometimes singing the same song type for a long time, making it difficult to collect equivalent song types or to sample the birds’ full repertoires. For example, 5-min recordings of males taken in different years did not contain equivalent song types, leading to low identification success. Although we were not successful in the re-identification of males based on general song characteristics, we discuss methods of acoustic identification which are not dependent on song repertoire content and are potentially valuable tools for the study of species such as the Chiffchaff.
A novel conditional Sgsh knockout mouse model recapitulates phenotypic and neuropathic deficits of Sanfilippo syndrome
Authors: Lau Adeline A. , King Barbara M. , Thorsen Carly L. , Hassiotis Sofia , Beard Helen , Trim Paul J. , Whyte Lauren S. , Tamang Sarah J. , Duplock Stephen K. , Snel Marten F. , Hopwood John J. , Hemsley Kim M.
Published: April 2017

Mucopolysaccharidosis (MPS) type IIIA, or Sanfilippo syndrome, is a neurodegenerative lysosomal storage disorder caused by a deficiency of the lysosomal enzyme N‐sulfoglucosamine sulfohydrolase (SGSH), involved in the catabolism of heparan sulfate. The clinical spectrum is broad and the age of symptom onset and the degree of preservation of cognitive and motor functions appears greatly influenced by genotype. To explore this further, we generated a conditional knockout (SgshKO) mouse model with ubiquitous Sgsh deletion, and compared the clinical and pathological phenotype with that of the spontaneous SgshD31N MPS‐IIIA mouse model. Phenotypic deficits were noted in SgshKO mice prior to SgshD31N mice, however these outcomes did not correlate with any shift in the time of appearance nor rate of accumulation of primary (heparan sulfate) or secondary substrates (GM2/GM3 gangliosides). Other disease lesions (elevations in lysosomal integral membrane protein‐II expression, reactive astrocytosis and appearance of ubiquitin‐positive inclusions) were also comparable between affected mouse strains. This suggests that gross substrate storage and these neuropathological markers are neither primary determinants, nor good biomarkers/indicators of symptom generation, confirming similar observations made recently in MPS‐IIIA patients. The SgshKO mouse will be a useful tool for elucidation of the neurological basis of disease and assessment of the clinical efficacy of new treatments for Sanfilippo syndrome.
Risk factors for poor bone health in primary mitochondrial disease
Authors: Gandhi Shifa S. , Muraresku Colleen , McCormick Elizabeth M. , Falk Marni J. , McCormack Shana E.
Published: April 2017

Introduction

Primary mitochondrial disease is caused by either mitochondrial or nuclear DNA mutations that impact the function of the mitochondrial respiratory chain. Individuals with mitochondrial disorders have comorbid conditions that may increase their risk for poor bone health. The objective of this retrospective electronic medical record (EMR) review was to examine risk factors for poor bone health in children and adults with primary mitochondrial disease.

Methods

Eighty individuals with confirmed clinical and genetic diagnoses of primary mitochondrial disease at the Children's Hospital of Philadelphia (CHOP) were included in this study. Risk factors and bone health outcomes were collected systematically, including: anthropometrics (low BMI), risk‐conferring co‐morbidities and medications, vitamin D status, nutrition, immobility, fracture history, and, where available, dual energy x‐ray absorptiometry (DXA) bone mineral density (BMD) results.

Results

Of patients 73% (n = 58) had at least one risk factor and 30% (n = 24) had four or more risk factors for poor bone health. The median number of risk factors per participant was 2, with an interquartile interval (IQI 0–4). In the subset of the cohort who were known to have sustained any lifetime fracture (n = 11), a total of 16 fractures were reported, six of which were fragility fractures, indicative of a clinically significant decrease in bone strength.

Conclusions

The prevalence of risk factors for poor bone health in primary mitochondrial disease is high. As part of supportive care, practitioners should address modifiable risk factors to optimize bone health, and have a low threshold to evaluate clinical symptoms that could suggest occult fragility fracture.
The effect of selective opioid receptor agonists and antagonists on epileptiform activity in morphine‐dependent infant mice hippocampal slices
Authors: Panahi Yousef , Saboory Ehsan , Rassouli Ali , Sadeghi‐Hashjin Goudarz , Roshan‐Milani Shiva , Derafshpour Leila , Rasmi Yousef
Published: April 2017

Hippocampal slices of mouse brain were used to estimate how selective agonist and antagonist of opioid receptors alter Low‐Mg+2 artificial cerebrospinal fluid (LM‐ACSF)‐induced epileptiform activities in normal and morphine‐dependent mice. Brain slices were obtained from control and morphine‐dependent mice. The morphine‐dependent group received morphine once a day for 5 consecutive days, and the control group received saline. All injections were administered subcutaneously (s.c) in a volume of 0.1 mL on postnatal days 14–18. Brain slices were perfused with LM‐ACSF along with selective agonist and antagonist of μ, κ and δ opioid receptors. Changes in spike count per unit of time were used as indices to quantify the effects of LM‐ACSF exposure in the slices. In both groups, DAMGO (selective μ opioid receptor agonist) and DPDPE (selective δ opioid receptor agonist) suppressed while Dyn‐A (selective κ opioid receptor agonist) potentiated the epileptiform activity. Meanwhile, BFN‐A (selective μ opioid receptor antagonist) recovered epileptiform activity in normal brain slices but not in morphine‐dependent ones. NTI (selective δ opioid receptor antagonist) and nor‐BNI (selective κ opioid receptor antagonist) decreased epileptiform activity. It seems that the excitatory effect of morphine on epileptiform activity was mediated through kappa receptors and its inhibitory effect was mediated via the mu receptor and, to a lesser degree, through the delta receptor. The pattern of effect was similar in normal and morphine‐dependent slices, but the intensity of the effect was significantly stronger in normal mice. Finding of this study might be considered for further research and attention in epilepsy treatment.
MRI from Picture to Proton
Authors: McRobbie Donald W. , Moore Elizabeth A. , Graves Martin J. , Prince Martin R.
Published: April 2017

MR is a powerful modality. At its most advanced, it can be used not just to image anatomy and pathology, but to investigate organ function, to probe in vivo chemistry, and even to visualise the brain thinking. However, clinicians, technologists and scientists struggle with the study of the subject. The result is sometimes an obscurity of understanding, or a dilution of scientific truth, resulting in misconceptions. This is why MRI from Picture to Proton has achieved its reputation for practical clarity. MR is introduced as a tool, with coverage starting from the images, equipment and scanning protocols and traced back towards the underlying physics theory. With new content on quantitative MRI, MR safety, multi-band excitation, Dixon imaging, MR elastography and advanced pulse sequences, and with additional supportive materials available on the book's website, this new edition is completely revised and updated to reflect the best use of modern MR technology.
Invasion Shadows: The Accumulation and Loss of Ecological Impacts from an Invasive Plant
Authors: Tekiela Daniel R. , Barney Jacob N.
Published: April 2017

Ecological impacts from invasive plants that have been identified include reductions in biodiversity, changes in resource cycling, and disruptions of ecosystem function. To mitigate these negative ecological impacts, managers work to remove invasive plants. However, removal does not necessarily immediately lead to a return to the uninvaded ecological state. Similarly, the accumulation rate of ecological impacts following invader establishment is almost entirely unknown for most species, hindering identification of optimal management times. The accumulation and loss (so-called legacy effects) of impacts following invader establishment and removal represent an “invasion shadow.” To begin to understand invasion shadows, we measured the changes in biotic and abiotic ecological impacts during establishment and following removal of the forest understory invader Japanese stiltgrass. We found that when the abiotic metrics were considered, seeded areas became more functionally similar to the invaded landscape and removed areas became more similar to the uninvaded landscape. However, while the plant community did not change in a 3-yr period during a new invasion, following invader removal, it became less similar to both the invaded and uninvaded landscape altogether, suggesting legacies. Surprisingly, all changes occurred almost immediately and persisted following invader establishment and removal. Our results show, at least in a 3-yr period, that ecosystems can respond to changes in invader abundance, and in some cases simply removing the invader could result in long-term changes to the resident plant community.
Swirling flow states in finite-length diverging or contracting circular pipes
Authors: Rusak Zvi , Zhang Yuxin , Lee Harry , Wang Shixiao
Published: April 2017

The dynamics of inviscid-limit, incompressible and axisymmetric swirling flows in finite-length, diverging or contracting, long circular pipes is studied through global analysis techniques and numerical simulations. The inlet flow is described by the profiles of the circumferential and axial velocity together with a fixed azimuthal vorticity while the outlet flow is characterized by a state with zero radial velocity. A mathematical model that is based on the Squire–Long equation (SLE) is formulated to identify steady-state solutions of the problem with special conditions to describe states with separation zones. The problem is then reduced to the columnar (axially-independent) SLE, with centreline and wall conditions for the solution of the outlet flow streamfunction. The solution of the columnar SLE problem gives rise to the existence of four types of solutions. The SLE problem is then solved numerically using a special procedure to capture states with vortex-breakdown or wall-separation zones. Numerical simulations based on the unsteady vorticity circulation equations are also conducted and show correlation between time-asymptotic states and steady states according to the SLE and the columnar SLE problems. The simulations also shed light on the stability of the various steady states. The uniqueness of steady-state solutions in a certain range of swirl is proven analytically and demonstrated numerically. The computed results provide the bifurcation diagrams of steady states in terms of the incoming swirl ratio and size of pipe divergence or contraction. Critical swirls for the first appearance of the various types of states are identified. The results show that pipe divergence promotes the appearance of vortex-breakdown states at lower levels of the incoming swirl while pipe contraction delays the appearance of vortex breakdown to higher levels of swirl and promotes the formation of wall-separation states.
Theory and application of reverberated direct and indirect noise
Authors: Rolland E. O. , De Domenico F. , Hochgreb S.
Published: April 2017

The generation of a temperature disturbance in a flow is accompanied by the production of acoustic waves (direct noise) and of an entropy perturbation. If this entropy perturbation is accelerated or decelerated (as is the case through a nozzle or flow restriction), additional acoustic waves are generated (indirect noise). Several studies have demonstrated this mechanism in controlled conditions by using entropy wave generators, in which entropy waves are generated and convected through a nozzle, leading to direct and indirect noise. An analytical analysis of the direct and indirect noise produced by the generation and acceleration of entropy waves in a reflective environment is presented. The effect of reverberation (repeated acoustic reflections) on low-frequency perturbations (characteristic of entropy wave generators) is determined analytically. These results are then implemented in a set of limit cases, showing the limit behaviours of such systems. The analytical model is applied to the case of the Cambridge entropy wave generator experiment, in which entropy waves are generated by an electric heater and accelerated through a subsonic orifice plate. Due to the clear time separation of direct and indirect noise in the experimental results, direct and indirect noise transfer functions can be extracted from the experimental data for the first time and compared directly with existing theoretical models. The backward-propagating indirect noise generated at an orifice plate is shown to be significantly higher than predicted by existing theoretical models for isentropic nozzles.
Pulsed jets driven by two interacting cavitation bubbles produced at different times
Authors: Tomita Y. , Sato K.
Published: April 2017

An experiment is performed using high-speed photography to elucidate the behaviours of jets formed by the interactions of two laser-induced tandem bubbles produced axisymmetrically for a range of dimensionless interaction parameters such as the bubble size ratio, $\unicode[STIX]{x1D709}$, the distance between the two cavitation bubbles, $l_{0}^{\ast }$, and the time difference in bubble generation, $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }$. A strong interaction occurs for $l_{0}^{\ast }<1$. The first bubble produced (bubble A) deforms because of the rapid growth of the second bubble (bubble B) to create a pulsed conical jet, sometimes with spray formation at the tip, formed by the small amount of water confined between the two bubbles. This phenomenon is followed by bubble penetration, toroidal bubble collapse, and the subsequent fast contraction of bubble B accompanied by a fine jet. The formation mechanism of the conical jet is similar to that of a water spike developed in air from a deformed free surface of a single growing bubble; however, the pressures of the gases surrounding each type of jet differ. The jet behaviours can be controlled by manipulating the interaction parameters; the jet velocity is significantly affected by $\unicode[STIX]{x1D709}$ and $l_{0}^{\ast }$, but less so by $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }$ for $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }>\unicode[STIX]{x0394}\unicode[STIX]{x1D703}_{c}^{\ast }$ ($\unicode[STIX]{x0394}\unicode[STIX]{x1D703}_{c}^{\ast }$ being the critical birth-time difference). The optimum time of jet impact, at which bubble A reaches its maximum volume, depends on $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }$. It is generally later for larger values of $\unicode[STIX]{x1D709}$. A pulsed jet could be used to create small pores in a cell membrane; therefore, the reported method may be useful for application in tandem-bubble sonoporation.