bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of herbicides in environmental water samples by simultaneous in‐syringe magnetic stirring‐assisted dispersive liquid–liquid microextraction and silylation followed by GC–MS
Authors: Suárez Ruth , Clavijo Sabrina , González Alba , Cerdà Víctor
Published: December 2017

An on‐line, fast, simple, selective, and sensitive method has been developed for the determination of three herbicides belonging to the following families: triazines (atrazine), chloroacetamide (alachlor), and phenoxy (2,4‐dichlorophenoxyacetic acid) in water samples. The method involves an in‐syringe magnetic stirring‐assisted dispersive liquid–liquid microextraction along with simultaneous silylation prior to their determination by gas chromatography with mass spectrometry. Extraction, derivatization, and preconcentration have been simultaneously performed using acetone as dispersive solvent, N‐methyl‐N‐tert‐butyldimethylsilyltrifluoroacetamide as derivatization agent and trichloroethylene as extraction solvent. After stirring for 180 s, the sedimented phase was transferred to a rotary micro‐volume injection valve (3 μL) and introduced by an air stream into gas chromatograph with mass spectrometry detector. Recovery and enrichment factors were 87.2–111.2% and 7.4–10.4, respectively. Relative standard deviations were in the ranges of 6.6–7.4 for intraday and 9.2–9.6 for interday precision. The detection limits were in the range of 0.045–0.03 μg/L, and good linearity was observed up to 200 μg/L, with R2 ranging between 0.9905 and 0.9964. The developed method was satisfactorily applied to assess the occurrence of the studied herbicides in groundwater samples. The recovery test was also performed with values between 77 and 117%.
An optimization of pretreatment for the phosphate conversion film on WE43 magnesium alloy
Authors: Dong Kaihui , Song Yingwei , Shan Dayong , Han En‐Hou
Published: December 2017

A two‐step method pretreatment was used to optimize the phosphate conversion film on WE43 magnesium alloy. The surface status of the pretreatment layers and their effect on the formation processes of phosphate conversion films were investigated using scanning electron microscopy (SEM), X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS) analyses. It was found that the second phases on the grain boundaries of WE43 were dissolved completely by two‐step method pretreatment. The thin pretreatment film first flaked off in the phosphate process, resulting in a more uniform surface status. Then, the phosphate particles were deposited more homogeneously. Combined with the electrochemical impedance spectroscopy (EIS) and immersion test results, the optimized pretreatment greatly improved the compactness of the conversion films, further to enhance its protective ability to Mg substrate.
Vibrational Spectra of Poly(ethylene terephthalate) Chains in the Mesomorphic Form
Authors: Rizzo Paola , Trotta Diletta , Musto Pellegrino , Guerra Gaetano
Published: December 2017

Vibrational (infrared and Raman) spectra of poly(ethylene terephthalate) (PET) chains included in the mesomorphic phase, as established by X‐ray diffraction patterns, are compared with spectra of corresponding amorphous and crystalline (triclinic) phases. The study indicates the presence of similar amounts of amorphous phase in semicrystalline and mesomorphic films. For the mesomorphic phase, occurrence of extended linear chains with disordered conformation, which was suggested by combination of X‐ray diffraction data and conformational analysis, is confirmed. In particular, a detailed analysis of conformationally sensitive spectral regions confirms the presence of sequences with trans OCCO dihedral angles and trans or gauche COCC dihedral angles. The reported analysis also allows discriminating between crystalline peaks corresponding to vibrational modes of long or short trans‐planar PET stretches.
Conjugated Polymer‐Based Nanoparticles for Cancer Cell‐Targeted and Image‐Guided Photodynamic Therapy
Authors: Peng Fei , Qiu Liang , Chai Ran , Meng Fanfan , Yan Chunmei , Chen Yulan , Qi Junjie , Zhan Yong , Xing Chengfen
Published: December 2017

Multifunctional materials with cell imaging and therapeutic functions are anticipated to provide promising agents in cancer treatment. Herein, folic acid modified conjugated polymer nanoparticles (FA‐CPNs) are exploited to target cancer cells and destroy the neighboring cancer cells. Folic acid in FA‐CPNs enables the strong binding with high affinity to folate receptor, a cancer‐cell‐associated protein, to target cancer cells. FA‐CPNs are able to produce cytotoxic reactive oxygen species upon irradiation 600 nm light, and therefore cause the cell death of folate receptor‐overexpressed cancer cells effectively. Therefore, the conjugated polymer‐based nanoparticles provide a multifunctional system for targeting cancer cells and photodynamic therapy.
Viscoelasticity and Dynamics of Confined Polyelectrolyte/Layered Silicate Nanocomposites: The Influence of Intercalation and Exfoliation
Authors: Romo‐Uribe Angel , Cardoso Judith
Published: December 2017

The influence of different confinement regimes on the linear viscoelastic properties of a polyelectrolyte, the protonated poly‐[(dimethylamino) ethyl methacrylate] (PDMAEMAH), is investigated. PDMAEMAH is reinforced with the layered silicate montmorillonite (MMT). Neat MMT and MMT treated with sulfobetaine and ammonia‐based surfactants (MMT/SB and MMT/NH, respectively) are utilized. Transmission electron microscopy and X‐ray scattering show that MMT and MMT/NH produce intercalated morphology, whereas MMT/SB produces an exfoliated morphology. Thus, the polyelectrolyte is under different confinement regimes. The confinement produces the increase of glass transition temperatureTg; however, the increase is larger for the (highly confined) intercalated morphology. Master curves are constructed applying time–temperature superposition. Strikingly, the viscoelastic spectra evidence that the intercalated morphology produces twofoldincreaseof rubber‐like modulus, whereas the exfoliated morphology produces over fourfoldreductionof rubber‐like modulus, both at 3 wt% clay concentration. The reduction of rubber‐like modulus suggests that an exfoliated morphology produces disruption of the entanglement density. Analysis in the segmental relaxation regime shows that the intercalated morphology induces longer relaxation times, that is, more dynamics retardation, in correlation with the increase of glass transition temperature. This research paves the road for better understanding of viscoelastic behavior and dynamics of molten polyelectrolytes under confinement.
On the Size‐Determining Role of the Comonomer in the Nucleation and Growth of Cationic Polystyrene Latex via Emulsion Polymerization
Authors: Meincke Thomas , Jordan Maximilian , Vogel Nicolas , Klupp Taylor Robin N.
Published: December 2017

The formation of positively charged polystyrene latex particles via the surfactant‐free emulsion polymerization of styrene with cationic initiator is investigated. Using the comonomer (vinylbenzyl)trimethyl‐ammonium chloride (VBTMAC) it is shown that the particle size can be tuned rather precisely between above 350 nm and below 70 nm. The simple functional dependence of the particle size on the inverse cube root of the comonomer concentration leads to propose, with reasonable assumptions, that VBTMAC comonomer addition allows the separation of nucleation and growth for this reaction. Thereby the comonomer concentration determines the nucleation rate and number of particles produced, while the styrene amount determines by how much the nucleated particles grow. Support for this model is obtained through zeta potential measurements at different pH values. The latter confirmed that the surface density of cationic groups resulting from the comonomer relative to that of groups resulting from the initiator decreases with decreasing comonomer concentration.
Hierarchical Polymer Blend Fibers of High Structural Regularity Prepared by Facile Solvent Vapor Annealing Treatment
Authors: Bauer Adam Joseph‐Podufaly , Grim Zachary Buchanan , Li Bingbing
Published: December 2017

In this study, a facile solvent vapor annealing (SVA) method is utilized to inscribe hierarchical secondary nanostructures onto electrospun poly(ε‐caprolactone)(PCL)/poly(ethylene oxide) (PEO) blend fibers. By carefully understanding the phase separation and crystallization behavior of PCL/PEO blends during the electrospinning process, one can tune the spatial distribution of the PCL phase, the growth of the PCL crystalline regions, and therefore the amount and even the sensitivity of free amorphous PCL chains in response to acetone vapor. Here, the PEO domains serve as mini‐dividers to restrict the growth of the semicrystalline PCL phase. During acetone vapor annealing, the PEO phase remains largely unchanged while swollen‐free amorphous PCL chains are deposited on pre‐existing PCL or even PEO crystalline lamellae, giving rise to hierarchical structures of high regularity. The morphologies of PCL/PEO hierarchical structures reported in this study are of striking uniformity, further demonstrating the reliability of the facile SVA method, not only for a few layers of thin fiber mats but also for thicker fiber mats.
Drop‐On‐Drop Multimaterial 3D Bioprinting Realized by Peroxidase‐Mediated Cross‐Linking
Authors: Sakai Shinji , Ueda Kohei , Gantumur Enkhtuul , Taya Masahito , Nakamura Makoto
Published: December 2017

A cytocompatible inkjet bioprinting approach that enables the use of a variety of bioinks to produce hydrogels with a wide range of characteristics is developed. Stabilization of bioinks is caused by horseradish peroxidase (HRP)‐catalyzed cross‐linking consuming hydrogen peroxide (H2O2). 3D cell‐laden hydrogels are fabricated by the sequential dropping of a bioink containing polymer(s) cross‐linkable through the enzymatic reaction and H2O2 onto droplets of another bioink containing the polymer, HRP, and cells. The ≈95% viability of enclosed mouse fibroblasts and subsequent elongation of the cells in a bioprinted hydrogel consisting of gelatin and hyaluronic acid derivatives suggest the high cytocompatibility of the developed printing approach. The existence of numerous polymers, including derivatives of polysaccharides, proteins, and synthetic polymers, cross‐linkable through the HRP‐catalyzed reaction, means the current approach shows great promise for biofabrication of functional and structurally complex tissues.
Influence of moisture source and sink regions on northeast monsoon rainfall
Authors: Suneetha P. , Latha P. , Ramalingeswara Rao S. , Bhanu Kumar O. S. R. U.
Published: December 2017

The northeast monsoon (NEM) over south India plays a vital role in producing light and moderate rainfall events during October through December. Excess NEM rainfall is mainly due to the intensified tropical cyclones and easterly waves from the Pacific east–west troughs over the Bay of Bengal. The main heat source and sink regions of this monsoon season are the western Pacific high and the Siberian high, respectively. Relative variations in the areal extent and intensity of these source and sink regions influence the NEM season by excess or deficient rainfall. Hence, the aim of the present study was to observe the impact of the Siberian high and the western Pacific high on the NEM rainfall in excess and deficient years. For this purpose, dynamic and thermodynamic parameters, the zonal and meridional winds, the velocity potential, the sea surface temperature and the relative humidity of the National Centers for Environmental Prediction and the National Center for Atmospheric Research (NCEP/NCAR) reanalysis data were used for the period 1951–2014. Analysis of these variables revealed the importance of the source and sink regions for the enhancement/reduction of NEM rainfall during excess/deficient years.
Downscaling the contribution to uncertainty in climate‐change assessments: representative concentration pathway (RCP) scenarios for the South Alborz Range, Iran
Authors: Mirdashtvan M. , Najafinejad A. , Malekian A. , Sa'doddin A.
Published: December 2017

One of the most important stages in climate‐change‐impact studies is uncertainty analysis, due to its great effect on both predictions and decision‐making. This study presents a procedure that characterizes the changes of climatic variables for the period 2011–2040 under representative concentration pathway (RCP) scenarios and then quantifies the uncertainty linked with the downscaling process using a bootstrapping method at 95% confidence intervals in one of the most vulnerable basins, the “Karaj‐Jajrud” located in the South Alborz Range, Iran. The results show that there is a consistent warming in mean air temperature time‐series with different magnitudes for all the RCP scenarios in the region for 2011–2040, whereas the results indicate decreasing precipitation compared with the baseline period for all RCP scenarios in the study area. Analysing the impacts of the downscaling process uncertainty on the prediction results shows that the contribution of this uncertainty source to the prediction uncertainty is relatively high, as about 30% of the downscaled temperature and precipitation data fall inside the 95% simulation confidence intervals. Furthermore, precipitation‐series uncertainty is more than the air temperature series. Climate change assessments and their uncertainty analysis can help managers to enhance preparedness and adaptation strategies in order to mitigate the consequences of natural hazards. More investigations can be done by adopting more general circulation models and other downscaling methods to compare the uncertainty that arises from each uncertainty source.
Lysophosphatidic acid accelerates development of porcine embryos by activating formation of the blastocoel
Authors: Shin Min‐Young , Lee Seung‐Eun , Son Yeo‐Jin , Park Yun‐Gwi , Jeong Sang‐Gi , Kim Eun‐Young , Park Se‐Pill
Published: December 2017

Culture media modifications, including the addition of various factors, are important for the in vitro production of oocytes and embryos. In this study, we investigated the effects of lysophosphatidic acid (LPA) on porcine embryo development. Porcine parthenogenetic embryos were cultured with 0, 0.1, 1, and 10 μM LPA for 7 days, or cultured in basic medium until Day 4 and then treated with LPA from Days 4 to 7. No difference in the in vitro development of embryos cultured with LPA for 7 days was observed. Conversely, rates of blastocyst and over‐expanded blastocyst formation were higher in the 0.1 and 1 µM LPA‐treated versus the other groups of embryos treated from Days 4 to 7. Moreover, formation of early blastocysts occurred earlier and embryo size was larger in LPA‐treated compared to control embryos. Expression of Connexin 43 and gap junction and cell adhesion‐related genes (GJC1 and CDH1, respectively) was also higher in LPA‐treated compared to control embryos. Despite no difference in the blastocyst total cell number between groups, the apoptotic index was lower in the LPA‐treated group than in the control group; indeed, BCL2L1 (B‐cell lymphoma 2‐like protein 1) expression increased while BAK (Bcl‐2 homologous antagonist killer) decreased in the LPA‐treated group. Thus, addition of LPA to the medium from Days 4 to 7 of culture improves blastocyst formation and aids the development of preimplantation embryos.
A fast algorithm for the spectral radii of weakly reducible nonnegative tensors
Authors: Zhou Guanglu , Wang Gang , Qi Liqun , Alqahtani Mohammed
Published: December 2017

In this paper, we propose a fast algorithm for computing the spectral radii of symmetric nonnegative tensors. In particular, by this proposed algorithm, we are able to obtain the spectral radii of weakly reducible symmetric nonnegative tensors without requiring the partition of the tensors. As we know, it is very costly to determine the partition for large‐sized weakly reducible tensors. Numerical results are reported to show that the proposed algorithm is efficient and also able to compute the spectral radii of large‐sized tensors. As an application, we present an algorithm for testing the positive definiteness of Z‐tensors. By this algorithm, it is guaranteed to determine the positive definiteness for any Z‐tensor.
Hydrogenolysis of C−O Chemical Bonds of Broad Scope Mediated by a New Spherical Sol–Gel Catalyst
Authors: Pandarus Valerica , Ciriminna Rosaria , Gingras Geneviève , Béland François , Pagliaro Mario , Kaliaguine Serge
Published: December 2017

The new spherical sol–gel hybrid material SiliaCat Pd0 selectively mediates the hydrogenolysis of aromatic alcohols, aldehydes, and ketones by using an ultralow catalytic amount (0.1 mol % Pd) under mild reaction conditions. The broad reaction scope as well as the catalyst's superior activity and pronounced stability open the route to green and convenient reductive deoxygenation processes of primary synthetic relevance in chemical research as well as in the fine chemical and petrochemical industries.
Choosing the Right Lens – When Round Must Become Square
Authors: Simon Stephanie
Published: December 2017

With image processing algorithms and in particular with deep learning being so powerful, it is tempting to concentrate on this processing side and less on the actual hardware taking the images. Lens selection is very often left to last in both R&D and product manufacturing cycles. Putting effort into selecting the right lens, will not only allow an engineer to leverage the full potential of a camera's image sensor but it is also one of the first tools of data reduction and system simplification, key points to building any solution. Familiarity with the following five key criteria will help select the best lens for any application.
Photonics Packaging Made Visible
Authors: Geuzebroek Douwe , Dekker Ronald , van Dijk Paul
Published: December 2017

Photonic integrated circuit technology for visible light enables new applications which are not possible to realize with existing discrete components [1]. As PIC technology has a more mature status in the infrared wavelength range around 1550 nm for telecom applications, certain assembly and packaging standards have already been implemented. However, the broad application scope, ranging, for instance, from confocal microscopy to biosensors and display applications, requires a different set of packaging technologies in creating the PIC into a robust and usable product. In this article, we describe – via a set of application examples different options – on how interfaces can be made to PICs for visible light which meets the requirements for these emerging applications.
Cover Image, Volume 67, Issue 1
Authors: Jeong Jae‐Hoon , Choi Myeon‐Cheon , Nagappan Saravanan , Lee Won‐Ki , Ha Chang‐Sik
Published: December 2017

The cover image, by Jae‐Hoon Jeong et al., is based on the Research Article Preparation and properties of poly(lactic acid)/lipophilized graphene oxide nanohybrids, DOI: 10.1002/pi.5478.

image
The protective role of teacher–student relationships against peer victimization and psychosocial distress
Authors: Sulkowski Michael L. , Simmons Jessica
Published: December 2017

This study examined whether teacher–student relationships protect against peer victimization and its negative psychosocial effects (i.e., depression, anxiety, and stress). Additionally, the influence of teacher–student relationships, peer relationships, and students’ perceptions of school order and discipline was investigated as these variables were expected to be negatively related to the former. Data were collected from high school‐aged adolescents (N = 539; 51% female) in the U.S. Southwest. Study results indicate that teacher–student relationships buffered against experiencing psychosocial distress associated with peer victimization. Although positive teacher–student relationships, peer relationships, and students’ perceptions of school order and discipline all were negatively associated with peer victimization and psychosocial distress, teacher–student relationships were robustly related to peer victimization and psychosocial distress over the influence of the previous variables. In other words, as a key study finding, teacher–student relationships may reduce the impact of peer victimization by mitigating its negative psychosocial effects in a robust yet relatively unexplored way. Therefore, although more research is needed, fostering positive teacher–student relationships might be an effective way to reduce peer victimization as well as its negative effects.
Promoting sisterhood: The impact of a culturally focused program to address verbally aggressive behaviors in Black girls
Authors: Aston Candice , Graves Scott L. , McGoey Kara , Lovelace Temple , Townsend Tiffany
Published: December 2017

New estimates report that Black girls are facing an educational crisis with regard to disproportionate disciplinary practices and academics. To date, there has been very limited research with regard to school‐based interventions that have been designed to help Black girls explore both their cultural and gender identity. This is problematic because Black girls are constantly faced with the task of disproving negative characterizations (i.e., angry, loud, and aggressive) and advocating for equitable treatment from teachers and school administrators. These negative characteristics often translate to lower academic expectations, harsher punishments, and juvenile justice involvement. To address this problem, a single‐subject study was conducted to investigate the effectiveness of implementing an 8‐week cultural‐empowerment program based on the Sisters of Nia curriculum. Results based on visual analysis, percentage of nonoverlapping data, and Tau‐U all show that the Sisters of Nia intervention led to a significant reduction in verbally aggressive behavior for all four participants. These findings serve as further support to incorporate culturally based interventions at the school level.
Training in strength‐based intervention and assessment methodologies in APA‐accredited psychology programs
Authors: Nichols Kayla , Graves Scott L.
Published: December 2017

The importance of identifying and building on individual strengths has been a key component of many psychoeducational theories and modalities focused on developing interventions. However, program training in this growing area is not well known. As such, this is the first study designed to ascertain the American Psychological Association–accredited psychology programs strength‐based training practices. Results show that a majority of faculty (83.9% of school psychology, 48.4% of counseling psychology, and 50.0% clinical psychology) thinks that strength‐based practices are very beneficial; however, training in these methodologies has not kept pace with faculty beliefs, with over 60% of faculty not being familiar with strength‐based manualized interventions. Implications are discussed in terms of improving the research base to alleviate trainers’ concerns and challenges that impede their implementation of dual models of mental health in their psychology programs.
Nonvolatile resistive memory devices based on ferrocene‐terminated hyperbranched polyimide derived from different dianhydrides
Authors: Tan Haiwei , Yu Huaxuan , Song Ying , Zhu Shiyang , Zhang Bo , Yao Hongyan , Guan Shaowei
Published: December 2017

A series of ferrocene‐terminated hyperbranched polyimides (HBPI‐Fcs) were synthesized from a tetra‐amine, bis(4‐(3,5‐bis (4‐amino‐2‐(trifluoromethyl) phenoxy) phenoxy) phenyl) methanon, and various dianhydrides, followed by termination with (4‐amino) phenyl ferrocene. All the HBPI‐Fcs possessed good organo‐solubility and high thermal stability. The devices based on HBPI‐Fcs exhibited bipolar and nonvolatile write‐once‐read‐many times (WORM) memory performance with various threshold voltages and the same ON/OFF current ratio of 104. Moreover, the devices possessed excellent bistability under a constant bias of −1.00 V during a test period of 104 s. The different charge trapping ability of the electron‐accepting moiety endowed the devices with different the threshold voltages. Mechanism analysis showed that the switching behavior was dominated by the charge trapping effect and the charge transfer was well fitted with the space‐current‐limited‐current (SCLC) and ohmic model. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 505–513
Careful investigation of the hydrosilylation of olefins at poly(ethylene glycol) chain ends and development of a new silyl hydride to avoid side reactions
Authors: Shin Hyunseo , Moon Bongjin
Published: December 2017

Hydrosilylation of olefin groups at poly(ethylene glycol) chain ends catalyzed by Karstedt catalyst often results in undesired side reactions such as olefin isomerization, hydrogenation, and dehydrosilylation. Since unwanted polymers obtained by side reactions deteriorate the quality of end‐functional polymers, maximizing the hydrosilylation efficiency at polymer chain ends becomes crucial. After careful investigation of the factors that govern side reactions under various conditions, it was related that the short lifetime of the unstable Pt catalyst intermediate led to the formation of more side products under the inherently dilute conditions for polymers. Based on these results, two new chelating hydrosilylation reagents, tris(2‐methoxyethoxy)silane (5) and 2,10‐dimethyl‐3,6,9‐trioxa‐2,10‐disilaundecane (6), have been developed. It was demonstrated that the hydrosilylation efficiency at polymer chain ends was significantly increased by employing the internally coordinating hydrosilane 5. In addition, employment of the internally coordinating disilane species 6 in an addition polymerization with 1,5‐hexadiene by hydrosilylation reaction yielded a polymer with high molecular weight (Mn = 9300 g/mol), which was significantly higher than that (Mn = 2600 g/mol) of the corresponding polymer obtained with non‐chelating dihydrosilane, 1,1,3,3‐tetramethyldisiloxane. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2018,56, 527–536
Participation and interest in support services among family caregivers of older adults with cancer
Authors: Dionne‐Odom J. Nicholas , Applebaum Allison J. , Ornstein Katherine A. , Azuero Andres , Warren Paula P. , Taylor Richard A. , Rocque Gabrielle B. , Kvale Elizabeth A. , Demark‐Wahnefried Wendy , Pisu Maria , Partridge Edward E. , Martin Michelle Y. , Bakitas Marie A.
Published: December 2017

Objective

The purpose of this study was to describe distressed and underprepared family caregiver's use of and interest in formal support services (eg, professional counseling, education, organizational assistance).

Method

Cross‐sectional mail survey conducted in communities of 8 cancer centers in Tennessee, Alabama, and Florida (response rate: 42%). Family caregivers of Medicare beneficiaries with pancreatic, lung, brain, ovarian, head and neck, hematologic, and stage IV cancers reported support service use and completed validated measures of depression, anxiety, burden, preparedness, and health.

Results

Caregivers (n = 294) were on average age 65 years and mostly female (73%), White (91%), and care recipients' spouse/partner (60%); patients averaged 75 years were majority male (54%) with lung cancer (39%). Thirty‐two percent of caregivers reported accessing services while 28% were “mostly” or “extremely” interested. Thirty‐five percent of caregivers with high depressive symptoms (n = 122), 33% with high anxiety symptoms (n = 100), and 25% of those in the lowest quartile of preparedness (n = 77) accessed services. Thirty‐eight percent of those with high depressive symptoms, 47% with high anxiety symptoms, and 36% in the lowest quartile of preparedness were “mostly” or “extremely” interested in receiving services. Being interested in support services was significantly associated with being a minority, shorter durations of caregiving, and with higher stress burden.

Conclusions

A large proportion of family caregivers, including those experiencing depression and anxiety symptoms and who were underprepared, are not using formal support services but have a strong interest in services. Strategies to increase service use may include targeting distressed caregivers early in their caregiving experience.
Demographic and clinical correlates of accelerometer assessed physical activity and sedentary time in lung cancer survivors
Authors: D'Silva Adrijana , Bebb Gwyn , Boyle Terry , Johnson Steven T. , Vallance Jeff K.
Published: December 2017

Objective

To determine demographic and clinical correlates of accelerometer assessed physical activity and sedentary time among a population‐based sample of lung cancer survivors.

Methods

Lung cancer survivors in Southern Alberta, Canada (N = 527) were invited to complete a mailed survey assessing socio‐demographics and wear an Actigraph® GT3X+ accelerometer for 7 days. Average daily minutes of physical activity and sedentary time were derived from the accelerometer data. Accelerometer data were processed using standard Freedson cutpoints, and correlates of physical activity and sedentary time were determined with linear regression.

Results

A total of 127 lung cancer survivors participated (mean age = 71 years), for a 24% response rate. Moderate‐to‐vigorous physical activity was negatively associated with being >60 years of age (β = −7.4, CI: −14.7, −0.10). Moderate‐to‐vigorous physical activity accumulated in 10‐minute bouts was associated with receiving surgery and adjuvant chemotherapy (β = 9.1, CI: 2.1, 16.1). Sedentary time was associated with being >60 years of age (β = 32.4, CI: 3.1, 61.7), smoking (β = 63.9, CI: 22.5, 105.4), and being overweight/obese (β = 28.6, CI: 6.4, 50.1).

Conclusion

Age, smoking history, and body mass index emerged as correlates of accelerometer assessed light, moderate, and vigorous physical activity, and sedentary time among lung cancer survivors.

Implications for Cancer Survivors

Identifying correlates of physical activity and sedentary time may aid in the development of targeted behavioral interventions for this population.
Microwave‐Assisted Synthesis of Biocompatible Silk Fibroin‐Based Carbon Quantum Dots
Authors: Ko Na Re , Nafiujjaman Md , Cherukula Kondareddy , Lee Sang Ju , Hong Seoung‐Jin , Lim Ho‐Nam , Park Chan Hum , Park In‐Kyu , Lee Yong‐Kyu , Kwon Il Keun
Published: December 2017

A biocompatible silk fibroin‐based carbon quantum dot (SF‐CQD) is first synthesized under microwave irradiation for a short time. This fast and environmentally safe technique produce well‐defined nanosized SF‐CQDs. The SF‐CQDs have good crystallinity, a strong emission peak in the blue‐color region, high quantum yield, and the potential for modification with various functional groups on the surface. These SF‐CQDs demonstrate stable emission, good water dispersity, low toxicity, and good biocompatibility. These properties show the great potential of these SF‐CQDs for use in biomedical applications including bioimaging, biosensing, and drug delivery systems.
In Vivo Targeted Cancer Theranostics by Core/Shell‐Structured Multifunctional Prussian Blue/PLGA “Nanococktails”
Authors: Shang Tingting , Liu Jianxin , Chen Yu , Hu Zicheng , Deng Liming , Ran Haitao , Li Pan , Zheng Yuanyi , Wang Dong , Wang Zhigang , Sun Yang
Published: December 2017

The construction of high‐performance nanotheranostic agent with Food and Drug Administration (FDA)‐approved materials for efficient treatment of breast cancer is still of great challenge. This work reports, for the first time, on the elaborate integration of two FDA‐approved materials together to construct a multifunctional core/shell‐structured “nanococktail” for cancer theranostics. The biocompatible Prussian blue nanoparticles with high photothermal‐conversion performance are coated by poly(lactic‐co‐glycolic acid) followed by further surface targeting engineering (folic acid conjugation). The anticancer drug paclitaxel is concurrently encapsulated into the nanocarrier with high efficiency and capacity. Especially, these “nanococktails” act as the desirable contrast agents for photoacoustic/magnetic resonance imaging dual‐mode diagnostic imaging, providing the potential for guidance and monitoring during the therapeutic process, which has been systematically demonstrated both in vitro and in vivo. Importantly, these “nanococktails” have demonstrated their high performance in synergistic in vivo photothermal therapy and chemotherapy against breast cancer tumor xenograft. This work not only provides a high‐performance theranostic “nanococktail” platform for efficient theranostic treatment of cancer but also paves a new way for the integration of various functional moieties together for realizing the specific diagnostic imaging‐guided and synergistic cancer therapy.
Robust Microencapsulated Silicone Oil with a Hybrid Shell for Reducing Propellant Erosion
Authors: Sun Na , Xiao Zhenggang
Published: December 2017

A morphologically stable silicon oil microcapsule base polystyrene as shell modified with TiO2 and Si3N4 nanoparticles was synthesized, characterized and applied as an inhibitor for high energy propellant to reduce erosion of gun barrel. The composite microcapsules were obtained by an eco‐friendly method. Embedding heat‐resistant TiO2 and Si3N4 nanoparticles in polystyrene shell enhances the reliability of polymeric shell. The anti‐erosion effect of composite microcapsules for high energy propellant was investigated by using an erosion tester. Results showed that the erosion property of high energy propellant with composite microcapsule was significantly decreased when compared to control sample (without microcapsules). It showed a decrease of 20.6 % in erosion mass when 7 wt.% of composite microcapsules were added to the high energy propellant. Moreover, the anti‐erosion efficiency of composite additives exhibited an increasing trend with the increase of their contents. The pressure and time history confirmed that the composite microcapsules also have ability to adjust the combustion performance of high energy propellants. The developed silicon oil microcapsule shows a potential application for propellant erosion additive.
Synergistic Effect of Single‐Walled Carbon Nanotubes and PEDOT:PSS in Thin Film Amorphous Silicon Hybrid Solar Cell
Authors: Alekseeva Alena A. , Rajanna Pramod Mulbagal , Anisimov Anton S. , Sergeev Oleg , Bereznev Sergei , Nasibulin Albert G.
Published: December 2017

We propose a simple fabrication method of thin film hybrid solar cells by combining single‐walled carbon nanotubes (SWCNTs) and poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with hydrogenated amorphous silicon (a‐Si:H). Electrically conductive polymer PEDOT:PSS introduced in a randomly oriented network of SWCNTs forms a coupled continuous heterojunction between PEDOT:PSS–SWCNT and a‐Si:H. We fabricated and compared the performance of SWCNT/a‐Si:H, PEDOT:PSS/a‐Si:H and PEDOT:PSS–SWCNT/a‐Si:H solar cells. The PEDOT:PSS–SWCNT/a‐Si:H solar cells resulted to have an efficiency of 1.6% with state‐of‐the‐art fill factor and open circuit voltage of 54% and 0.803 V, respectively.
Protective effect of gentiopicroside from Gentiana macrophylla Pall. in ethanol‐induced gastric mucosal injury in mice
Authors: Yang Yang , Wang Ziye , Zhang Li , Yin Bing , Lv Le , He Jiao , Chen Ziyang , Wen Xin , Qiao Boling , Sun Wenji , Fang Minfeng , Zhang Yongmin
Published: December 2017

Gentiopicroside isolated from gentiana macrophylla Pall. belongs to iridoid glycosides. This study aimed to evaluate the protective effect of gentiopicroside against ethanol‐induced gastric mucosal injury in mice. Mice were proactively administrated with gentiopicroside by intragastric administration once a day for 3 consecutive days. On the 3rd day, gastric ulcer in mice was induced with 70% ethanol after the last intragastric administration. The stomach tissues were submitted for evaluation of the severity of gastric mucosal alterations. Gentiopicroside administrated orally ameliorated the severity of gastric mucosal alterations. Oral administration of gentiopicroside significantly increased heat shock protein‐70 and glutathione levels and superoxide dismutase activity, normalized epidermal growth factor and vascular endothelial growth factor levels, and decreased the levels of tumour necrosis factor‐α, interleukin‐6 and malondialdehyde, and myeloperoxidase activity in gastric tissue. These findings demonstrated that gentiopicroside has protective effect against ethanol‐induced gastric mucosal injury in mice through the improvements of antioxidative and anti‐inflammatory effects, as well as up‐regulation of heat shock protein‐70 level and normalization of epidermal growth factor and vascular endothelial growth factor levels. The results presented in this study provide some evidence for the development of a novel antigastric ulcer agent.
Inhibitory effect of sulphated polysaccharide porphyran (isolated from Porphyra yezoensis) on RANKL‐induced differentiation of RAW264.7 cells into osteoclasts
Authors: Ueno Mikinori , Cho Kichul , Isaka Shogo , Nishiguchi Tomoki , Yamaguchi Kenichi , Kim Daekyung , Oda Tatsuya
Published: December 2017

Safe and efficient therapeutic agents for bone diseases are required in natural sources. We previously found that edible seaweed‐derived polysaccharide porphyran exhibited anti‐inflammatory effects through the down regulation of nuclear factor‐κB. The aim of this study was to investigate the availability of porphyran as a therapeutic agent for bone diseases. The effects of porphyran on receptor activator of nuclear factor κB ligand (RANKL)‐induced osteoclastogenesis in RAW264.7 cells were examined. Porphyran suppressed RANKL‐induced osteoclast formation in a concentration‐dependent manner (6.25–50 μg/ml) without any cytotoxic effects. Furthermore, real‐time polymerase chain reaction analyses indicated that porphyran at 50 μg/ml significantly attenuated the RANKL‐induced increase in the mRNA levels of osteoclastogenesis‐related marker genes such as nuclear factor of activated T cells, tartrate‐resistant acid phosphatase, cathepsin K, and matrix metalloproteinase‐9 in RAW264.7 cells. To our knowledge, this is the first report showing that edible‐seaweed‐derived polysaccharide porphyran can suppress RANKL‐induced osteoclastogenesis. Our results suggest that porphyran can be used as a safe therapeutic agent to improve osteoclast‐related pathological conditions.
A novel mechanism for the isomerization of N2O4 and its implication for the reaction with H2O and acid rain formation
Authors: Putikam Raghunath , Lin Ming‐Chang
Published: December 2017

We have discovered, by high‐level quantum‐chemical calculations, a new and predominant isomerization mechanism for N2O4 → ONONO2 via a roaming‐like transition state occurring unimolecularly or bimolecularly during collision with H2O. The new mechanism allows N2O4 to react with H2O with a significantly lower barrier (< 13.1 kcal/mol) than the commonly known tight transition state (∼30‐45 kcal/mol) by concurrent stretching of the NN bond and rotation of one of the NO2 groups to form trans‐ONONO2, which then undergoes a rapid metathetical reaction with H2O in the gas phase and in aqueous solution. The results have a significant implication for the hydrolysis of N2O4 in water to produce HONO and HNO3. Rate constants for the isomerization and hydrolysis reactions have been predicted for atmospheric modeling applications.
Protein identification in imaging mass spectrometry through spatially targeted liquid micro‐extractions
Authors: Ryan Daniel J. , Nei David , Prentice Boone M. , Rose Kristie L. , Caprioli Richard M. , Spraggins Jeffrey M.
Published: December 2017

Rationale

Liquid extraction surface analysis (LESA) can be used to generate spatially directed protein identifications in an imaging mass spectrometry (IMS) workflow. This approach involves the use of robotic micro‐extractions coupled to online liquid chromatography (LC). We have characterized the extraction efficiency of this method as well as its ability to identify proteins from a matrix assisted laser/desorption ionization (MALDI) IMS experiment.

Methods

Proteins and peptides were extracted from transverse sections of a rat brain and sagittal sections of a mouse pup using liquid surface extractions. Extracts were either analyzed by online LC coupled to a high mass resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer or collected offline and analyzed by traditional LC/MS methods. Identifications were made using both top‐down and bottom‐up methodologies. MALDI images were acquired on a 15T FTICR mass spectrometer at 125 μm spatial resolution.

Results

Robotic liquid surface extractions are reproducible across various tissue types, providing significantly improved spatial resolution, with respect to extractions, while still allowing for a robust number of protein identifications. A single 2‐μL extract can provide identification of over 14,000 peptides with little sample preparation, increasing throughput for spatially targeted workflows. Surface extractions from tissue were coupled directly to LC to gather spatially relevant proteomics data.

Conclusions

Robotic liquid surface extractions can be used to interrogate discrete regions of tissue to provide protein identifications with high throughput, accuracy, and robustness. The direct coupling of tissue surface extractions and LC offers a new and effective approach to provide spatial proteomics data in an imaging experiment.
Differentiation of isomeric methylanilines by imidization and gas chromatography/mass spectrometry analysis
Authors: Chen Mengmeng , Zhu Guohua , Xu Jiaxiang , Zhang Huarong , Liu Jinsong , Jiang Kezhi
Published: December 2017

Rationale

Carcinogenic o‐methylaniline is one of the banned aromatic amines in azo dyes, but it is very difficult to distinguish it from its noncarcinogenic isomers due to their identical retention time on chromatography and similar mass spectra.

Methods

Imidization of the isomeric methylanilines was carried out by treatment with benzaldehyde under mild conditions. The formed derivatives were analyzed by gas chromatography/mass spectrometry (GC/MS). Theoretical calculations were carried out on the Gaussian 03 program by using the density functional theory method at the B3LYP/6‐311+G(d,p) level.

Results

Imidization of methylanilines occurred easily and gave rise to the corresponding N‐methylbenzylidene benzenamines. The isomeric derivatives were completely separated by GC, and thus the three isomeric methylanilines could be determined simultaneously. Due to the ortho effect, the derivative from o‐methylaniline has a characteristic fragment ion at m/z 118 with a stable bicyclic structure, and it could be easily differentiated from the meta‐ and para‐isomers in electron ionization mass spectrometry.

Conclusions

These results provided a promising solution for simultaneous determination of isomeric methylanilines.
Secure estimation for cyber‐physical systems with adversarial attacks and unknown inputs: An L2‐gain method
Authors: Xie Chun‐Hua , Yang Guang‐Hong
Published: December 2017

This paper investigates the attack‐resilient state estimation problem for linear systems with adversarial attacks and unknown inputs, where the upper bound of the unknown inputs is unknown. It is assumed that the attacker has limited resources and can only manipulate a certain number of sensors. In most of the existing observer design approaches for the systems with unknown inputs even in the absence of attacks, the observer matching condition should be satisfied. To overcome this restriction, a novel switched observer is proposed, where the matched unknown inputs will be completely compensated by means of the outputs and the mismatched part will be suppressed in terms of L2‐gain rejection property. Meanwhile, the observer can provide an attack‐resilient state estimation. Compared with the existing results, the proposed observer can guarantee that the resulting observer error system is stable with unknown input attenuation level γ that can be optimized. Finally, a simulation example of an unmanned ground vehicle is provided to show the effectiveness of the proposed approach.
The conundrum of social class: Disparities in publishing among STEM students in undergraduate research programs at a Hispanic majority institution
Authors: Grineski Sara , Daniels Heather , Collins Timothy , Morales Danielle X. , Frederick Angela , Garcia Marilyn
Published: December 2017

Research on the science, technology, engineering, and math (STEM) student development pipeline has largely ignored social class and instead examined inequalities based on gender and race. We investigate the role of social class in undergraduate student research publications. Data come from a sample of 213 undergraduate research participants majoring in STEM at a Hispanic‐majority institution. Based on generalized estimating equations that adjust for student demographics, research confidence, mentoring experiences, duration/number of research experiences, and clustering by major, we find that higher income students and continuing‐generation students (vs. first‐generation students) were significantly more likely to publish. Continuing‐generation students had an even greater likelihood of publishing than first‐generation students as students accrued more research confidence, spent more hours/week with faculty mentors, and conducted research for more months. Results suggest that undergraduate research programs designed to enhance diversity may help close some gaps (e.g., gender) but inadvertently reproduce class inequalities.
Superbase‐Added Choline Chloride‐Based Deep Eutectic Solvents for CO2 Capture and Sequestration
Authors: Bhawna  , Pandey Ashish , Pandey Siddharth
Published: December 2017

Deep eutectic solvents (DESs) have emerged as inexpensive and environmentally‐benign liquid media for potential usage in chemical sciences. CO2 capture and sequestration by various substances is an active area of research in green chemistry. CO2 capture ability of DES‐based systems composed of salt choline chloride mixed with hydrogen bond donors urea (named reline), ethylene glycol (named ethaline), and monoethanolamine (named MEACC), are assessed in the absence and presence of three superbases: 1,5‐diazabicyclo[4.3.0]‐non‐5‐ene (DBN), 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU), and 1,5,7‐triazabicyclo[4.4.0]‐dec‐5‐ene (TBD), respectively. Addition of superbase is found to significantly increase the CO2 capture ability of the DESs reline and ethaline; for the DES MEACC, the CO2 capture ability is not changed much as monoethanolamine and MEACC on their own exhibit appreciable CO2 capture efficiency. It is found that the overall efficiency of CO2 capture is the best with superbase DBN as compared to DBU or TBD due to the lower steric hindrance around the imine structure. Presence of glycerol in the superbase‐added DESs results in decrease in CO2 capture ability due to significantly lower solubility of CO2 in glycerol. 13C NMR, FTIR and Raman spectroscopic measurements reveal that major part of the captured CO2 binds covalently to the electron‐rich functionalities present on the components of the DES with superbase assisting this association. The reversibility of the captured CO2 is assessed by introducing N2 gas into the CO2 captured superbase‐added DES system; it is found that only 21–25% CO2 by weight could be removed from the system through five cycles. Heating the CO2 captured superbase‐added DES system to 60 °C and 100 °C results in loss of only 23% and 35% CO2 by weight, respectively. Intramolecular excimer intensity of 1,10‐bis(1‐pyrenyl)decane and steady‐state fluorescence anisotropy of rhodamine 6G fluorescence probes effectively monitor the CO2 capture process as viscosity of the superbase‐added DES increases as more‐and‐more CO2 is captured. Efficiency, effectiveness, and robustness of superbase‐added DES‐based systems towards CO2 capture and sequestration is amply highlighted.