bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient design and hardware implementation of a secure communication scheme for smart grid
Authors: Abbasinezhad‐Mood Dariush , Nikooghadam Morteza
Published: April 2018

In smart grid, bidirectional communications between the smart meters and control center are subject to several security challenges. Since the smart meters have limited storage space and processing capability, the suggested communication scheme not only must consider the security requirements but also should put the least possible burden on the smart meters' resources. In 2014, an interesting communication scheme has been proposed for the secure consumption reports transmission of the smart meters to the neighbor gateways. In this paper, we first show that this scheme is vulnerable to the smart meter's memory modification, pollution, and denial of service attacks; then, we propose an authenticated communication scheme, which not only is secure against the aforementioned attacks, but also is much more efficient in terms of storage space, communication overhead, and computational complexity. Moreover, our scheme also presents the details of control messages transmission from the neighborhood gateways to the smart meters. Our comparative analysis with several recently published schemes indicates that the proposed scheme is more suitable than the previous ones. More significantly, our realistic implementation on ATmega2560, as a suitable candidate to be used for the smart meters, confirms our claim.
Effects of winter food provisioning on the phenotypes of breeding blue tits
Authors: Plummer Kate E. , Bearhop Stuart , Leech David I. , Chamberlain Dan E. , Blount Jonathan D.
Published: April 2018

Throughout the Western World, huge numbers of people regularly supply food for wild birds. However, evidence of negative impacts of winter feeding on future reproduction has highlighted a need to improve understanding of the underlying mechanisms shaping avian responses to supplementary food. Here, we test the possibility that carry‐over effects are mediated via their impact on the phenotypes of breeding birds, either by influencing the phenotypic structure of populations through changes in winter survival and/or by more direct effects on the condition of breeding birds. Using a landscape‐scale 3‐year study of blue tits (Cyanistes caeruleus), we demonstrate the importance of nutritional composition of supplementary food in determining carry‐over effect outcomes. We show that breeding populations which had access to vitamin E‐rich foods during the previous winter were comprised of individuals with reduced feather carotenoid concentrations, indicative of lower pre‐feeding phenotypic condition, compared to fat‐fed and unfed populations. This suggests that supplementary feeding in winter can result in altered population phenotypic structure at the time of breeding, perhaps by enhancing survival and recruitment of lower quality individuals. However, supplementation of a fat‐rich diet during winter was detrimental to the oxidative state of breeding birds, with these phenotypic differences ultimately found to impact upon reproductive success. Our findings demonstrate the complex nature by which supplementary feeding can influence wild bird populations.
Age × stage‐classified demographic analysis: a comprehensive approach
Authors: Caswell Hal , de Vries Charlotte , Hartemink Nienke , Roth Gregory , van Daalen Silke F.
Published: April 2018

This paper presents a comprehensive theory for the demographic analysis of populations in which individuals are classified by both age and stage. The earliest demographic models were age classified. Ecologists adopted methods developed by human demographers and used life tables to quantify survivorship and fertility of cohorts and the growth rates and structures of populations. Later, motivated by studies of plants and insects, matrix population models structured by size or stage were developed. The theory of these models has been extended to cover all the aspects of age‐classified demography and more. It is a natural development to consider populations classified by both age and stage. A steady trickle of results has appeared since the 1960s, analyzing one or another aspect of age × stage‐classified populations, in both ecology and human demography. Here, we use the vec‐permutation formulation of multistate matrix population models to incorporate age‐ and stage‐specific vital rates into demographic analysis. We present cohort results for the life table functions (survivorship, mortality, and fertility), the dynamics of intra‐cohort selection, the statistics of longevity, the joint distribution of age and stage at death, and the statistics of life disparity. Combining transitions and fertility yields a complete set of population dynamic results, including population growth rates and structures, net reproductive rate, the statistics of lifetime reproduction, and measures of generation time. We present a complete analysis of a hypothetical model species, inspired by poecilogonous marine invertebrates that produce two kinds of larval offspring. Given the joint effects of age and stage, many familiar demographic results become multidimensional, so calculations of marginal and mixture distributions are an important tool. From an age‐classified point of view, stage structure is a form of unobserved heterogeneity. From a stage‐classified point of view, age structure is unobserved heterogeneity. In an age × stage‐classified model, variance in demographic outcomes can be partitioned into contributions from both sources. Because these models are formulated as matrices, they are amenable to a complete sensitivity analysis. As more detailed and longer longitudinal studies are developed, age × stage‐classified demography will become more common and more important.
Modeling continuous time series with many zeros and an application to earthquakes
Authors: Wang Y. , Wang T. , Zhuang J.
Published: April 2018

We introduce a way to discretize a point process such as earthquakes into time series and propose a class of two‐part autoregressive (2PAR) models for continuous time series data with excess zeros to analyze the dependence structure in such discretized point processes. In the 2PAR models, we employ a Bernoulli variable to model the excess zeros and use autoregressive processes to describe the serial correlation. Using this class of models, we can model correlations that exist in either zeros or nonzeros in the data. We introduce a class of residual analysis to check the goodness‐of‐fit of the proposed models and a forecasting procedure using simulation to check the performance of the models. A simulation study illustrates that the estimators of the proposed models are consistent. Application to the 2010 Darfield earthquake sequence in New Zealand shows that the 2PAR models with serial correlation in both the presence probability and the earthquake stress release provide higher information gain against a reference model.
Numerical and experimental investigations on inelastic cyclic performance of mid‐span gusset plate connections
Authors: Kumar P. C. Ashwin , Sahoo Dipti Ranjan
Published: April 2018

The design and detailing of gusset plate connections greatly influence the seismic performance of a special concentrically braced frame (SCBF). Recently, a balanced design approach has been proposed in order to develop significant inelastic deformation from multiple yield mechanisms and to delay the failure of connections of SCBF system. Although extensive studies have been conducted on the corner gusset plate connections of SCBFs, research on the detailing of mid‐span beam gusset plates is rather limited. This study aims at investigating the required free length for the detailing of the mid‐span gusset plates with different brace slenderness ratios. A nonlinear finite element analysis has been conducted for a braced frame with 4 different values of linear clearance in the mid‐span gusset plates and 2 values of brace slenderness ratios. In all simulation models, the corner gusset plates have been designed using balanced design approach and detailed using an elliptical clearance of 8 times the gusset plate thickness. An experimental study has also been conducted on 2 gusset plate sub‐assemblages having similar brace slenderness ratio but with 2 different values of linear clearance in the middle gusset plates. The lateral drift capacity corresponding to the brace fracture and the level of damage are found to be dependent on the detailing of the gusset plates. Based on the results of numerical and experimental studies, the required free length has been recommended for the detailing of middle gusset plates of SCBFs of different brace slenderness ratios.
The use of intensity‐based Doppler variance method for single vessel response to functional neurovascular activation
Authors: Kuo Wen‐Chuan , Kuo Yue‐Ming , Syu Jia‐Pu , Wang Han‐Lin , Lai Chi‐Ming , Chen Jia‐Wei , Lo Yu‐Chun , Chen You‐Yin
Published: April 2018

This study presents 1 use of optical coherence tomography (OCT) angiography technique to examine neurovascular coupling effect. Repeated B‐scans OCT recording is performed on the rat somatosensory cortex with cranial window preparation while its contralateral forepaw is electrically stimulated to activate the neurons in rest. We use an intensity‐based Doppler variance (IBDV) algorithm mapped cerebral blood vessels in the cortex, and the temporal alteration in blood perfusion during neurovascular activation is analyzed using the proposed IBDV quantitative parameters. By using principal component analysis‐based Fuzzy C Means clustering method, the stimulus‐evoked vasomotion patterns were classified into 3 categories. We found that the response time of small vessels (resting diameter 14.9 ±6.6 μm), middle vessels (resting diameter 21.1 ±7.9 μm) and large vessels (resting diameter 50.7 ±6.5 μm) to achieve 5% change of vascular dilation after stimulation was 1.5, 2 and 5.5 seconds, respectively. Approximately 5% peak change of relative blood flow (RBF) in both small and middle vessels was observed. The large vessels react slowly and their responses nearly 4 seconds delayed, but no significant change in RBF of the large vessels was seen.
Photobiomodulation of a flowable matrix in a human skin ex vivo model demonstrates energy‐based enhancement of engraftment integration and remodeling
Authors: Neves Lia M. G. , Parizotto Nivaldo A. , Cominetti Marcia R. , Bayat Ardeshir
Published: April 2018

The use of dermal substitutes to treat skin defects such as ulcers has shown promising results, suggesting a potential role for skin substitutes for treating acute and chronic wounds. One of the main drawbacks with the use of dermal substitutes is the length of time from engraftment to graft take, plus the risk of contamination and failure due to this prolonged integration. Therefore, the use of adjuvant energy‐based therapeutic modalities to augment and accelerate the rate of biointegration by dermal substitute engraftments is a desirable outcome. The photobiomodulation (PBM) therapy modulates the repair process, by stimulating cellular proliferation and angiogenesis. Here, we evaluated the effect of PBM on a collagen‐glycosaminoglycan flowable wound matrix (FWM) in an ex vivo human skin wound model. PBM resulted in accelerated rate of re‐epithelialization and organization of matrix as seen by structural arrangement of collagen fibers, and a subsequent increased expression of alpha‐smooth muscle actin (α‐SMA) and vascular endothelial growth factor A (VEGF‐A) leading to an overall improved healing process. The use of PBM promoted a beneficial effect on the rate of integration and healing of FWM. We therefore propose that the adjuvant use of PBM may have utility in enhancing engraftment and tissue repair and be of value in clinical practice.
Nobiletin protects human retinal pigment epithelial cells from hydrogen peroxide–induced oxidative damage
Authors: Liu Libin , Wu Xing wei
Published: April 2018

Nobiletin (3′,4′,5,6,7,8‐hexamethoxyflavone), a dietary polymethoxylated flavonoid found in Citrus fruits, has been reported to have antioxidant effect. However, the effect of nobiletin on human retinal pigment epithelium (RPE) cells induced by hydrogen peroxide (H2O2) is still unclear. Therefore, we investigated the protective effect of nobiletin against H2O2‐induced cell death in RPE cells. Our results demonstrated that nobiletin significantly increased cell viability from oxidative stress. Nobiletin inhibited H2O2‐induced ROS production and caspase‐3/7 activity in ARPE‐19 cells. Furthermore, nobiletin significantly increased Akt phosphorylation in ARPE‐19 cells exposed to H2O2. Meanwhile, LY294002, an inhibitor of PI3K/Akt, abolished the protective effect of nobiletin against H2O2‐induced decreased cell viability and increased caspase‐3/7 activity in ARPE‐19 cells. In summary, these data show that nobiletin protects RPE cells against oxidative stress through activation of the Akt‐signaling pathway. Thus, nobiletin should be an oxidant that attenuates the development of age‐related macular degeneration.
Signal pathways, diseases, and functions associated with the miR‐19a/92a cluster and the use of berberine to modulate the expression of this cluster in multiple myeloma cells
Authors: Yin Zhao , Yang Juhua , Ning Rong , Liu Yanjun , Feng Maoxiao , Gu Chunmin , Fei Jia , Li Yumin
Published: April 2018

Background

Berberine downregulated miR‐19a/92a cluster expression in multiple myeloma (MM) cells.

Methods

The cell viability of MM cells after berberine treatment was measured by CCK8 assay. qRT‐PCR assay validated miR‐19a/92a expression in multiple myeloma cells. TAM database analyzed miR‐19a/92a‐associated disease. miREnvironment database revealed that effects of environmental factors on the miR‐19a/92a cluster. By targeting the seed region in the miRNA, the role of t‐anti‐miR‐19a/92a cluster was evaluated by cell proliferation, migration, and colony formation.

Results

Berberine inhibited the cell viability of MM cells and downregulated the expression of miR‐19a/92a. Seven kinds of hematological malignancies are closely associated with miR‐19a/92a expression. By targeting the seed region of the miRNA, t‐anti‐miR‐19a/92a significantly inhibits multiple myeloma cell proliferation, migration, and colony formation.

Conclusion

Our findings may exhibit that miR‐19a/92a cluster is a therapeutic target for MM and provide new mechanistic insight into the anti‐MM effects of certain compounds in traditional Chinese herbal medicines.
Efficacy and safety of granulocyte adsorption apheresis in elderly patients with ulcerative colitis
Authors: Ito Ayumi , Omori Teppei , Hanafusa Norio , Tsuchiya Ken , Nakamura Shinichi , Tokushige Katsutoshi
Published: April 2018

Background

Elderly ulcerative colitis (UC) is increasing. Elderly UC differ from younger UC with respect to the course of their disease. Granulocyte adsorption apheresis (CAP) is often used to treat elderly UC. We retrospectively analyzed the cases of elderly UC who underwent CAP for remission induction therapy in a comparison with younger UC.

Methods

96 patients with UC underwent CAP. Patients who concurrently received tacrolimus, biological agents, or high‐dose steroid therapy were excluded. The remaining 80 patients were evaluated. We divided them into an elderly group (aged ≥65 years) and a younger group, and then we compared the groups' (1) clinical characteristics, (2) the efficacy and adverse effects of CAP, and (3) the complications of PSL.

Results

The remission rate was 70.8% in the elderly group and 87.5% in the younger group. There were significant differences between the two groups with respect to the age at the onset of UC, the estimated glomerular filtration rate on admission, underlying diseases, and complications of PSL therapy. Adverse effects of CAP included headache, complications of blood reinfusion, heparin allergy, hypotension, and failure of blood removal. There were significant differences between the two groups with respect to the complications of PSL therapy (all P < .05).

Conclusions

Although the elderly group had longer durations of UC, a higher prevalence of underlying diseases, and a higher frequency of adverse events due to PSL therapy. No serious adverse effects of CAP occurred in either group. Thus, CAP was safe and effective in both younger and elderly UC.
Myotendinous junction plasticity in aged ovariectomized rats submitted to aquatic training
Authors: Rissatto Sierra Luan , Fávaro Gabriel , Cerri Bruno Rubin , Rocha Lara Caetano , de Yokomizo de Almeida Sonia Regina , Watanabe Ii‐Sei , Ciena Adriano Polican
Published: April 2018

The study aims to describe the tissue plasticity of MTJ through the morphological analysis of MTJ soleus in ovariectomized aged female Wistar rats submitted to aquatic training. Forty aged Wistar rats, 1 year and 2 months of age, were divided into four groups: sedentary (S), trained (T), ovariectomized (O), and trained/ovariectomized (OT). Employing the transmission electron microscopy, the ultrastructural and morphometric elements were revealed. In the S group, changes in morphological characteristics as a consequence of the aging process were seen, demonstrated by the conical shape of the muscle cell extremity, a large area with collagen deposit, and misalignment of sarcomeres in series. The T group presented ample adjustments when revealed the organization of MTJ, through the increase of the contact area and greater lengths of sarcoplasmatic invaginations and evaginations. The O group revealed extensive tissue disorganization with muscle atrophy, reduction of MTJ contact area, and consequently, changes in sarcoplasmatic invaginations and evaginations. The OT group demonstrated extensive remodeling with restructuring MTJ through the increase of tissue contact area, extensive organization, parallel arrangement, and increased length of sarcoplasmatic invaginations and evaginations. The distal sarcomeres presented higher lengths compared to the proximal sarcomeres in both the groups. We conclude that aquatic training was effective in the organization and structural remodeling of the myotendinous interface of ovariectomized aged rats. There was a greater area of contact, and consequently, greater resistance in the myotendinous interface promoting a lower predisposition to injuries.
Limitations of skipping echoes for exponential T2 fitting
Authors: McPhee Kelly C. , Wilman Alan H.
Published: April 2018

Background

Exponential fitting of multiecho spin echo sequences with skipped echoes is still commonly used for quantification of transverse relaxation (T2).

Purpose

To examine the efficacy of skipped echo methods for T2 quantification against computational modeling of the exact signal decay.

Study Type

Prospective comparison of methods.

Subjects/Phantom

Eight volunteers were imaged at 4.7T, six volunteers at 1.5T, and phantoms ([MnCl2] = 68–270 mM).

Field Strength/Sequence

1.5T and 4.7T; multiple‐echo spin echo.

Assessment

Exponential fitting for T2 using all echoes, skipping the first echo or skipping all odd echoes, compared with Bloch simulations. Resulting T2 values were examined over a range of T2 (10–150 msec), refocusing flip angles (90–270°), and echo train lengths (ETL = 6–32).

Statistical Tests

Shapiro–Wilk tests and Q‐Q plots were used to check for normality of data. Paired sample t‐tests and Wilcoxon rank tests were used to compare fitting models using α = 0.05. Multiple comparisons were accounted for with Bonferroni correction.

Results

In examined regions of interest, typical incorrect estimation of T2 ranged from 23–39% for exponential fitting of all echoes, or 15–32% for skipped echo methods. In vivo, T2 estimation error was reduced to as little as 10% with skipped echo methods using 180° refocusing and ETL = 8, although error varied due to refocusing angle, T2, and ETL. In vivo, skipped echo T2 values were significantly different than all echo exponential fitting (P < 0.004), but also were significantly different from reference values (P < 0.002, except frontal white matter). Simulations showed skipping the first echo was the most effective form of exponential fitting, in particular for T2 <50 msec and ETL = 8, with potential to reduce T2 errors to 10%, depending on refocusing angle and T2.

Data Conclusion

Skipping echoes is insufficient for avoiding stimulated echo contamination. Resulting T2 errors depend on a complicated interplay of T2, refocusing angle, and ETL. Modeling of the multiecho sequence is recommended.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2018;47:1432–1440.
Declining hailstorm frequency in China during 1961–2015 and its potential influential factors
Authors: Zhao Wenhui , Guo Jianping , Yao Zhanyu , Yun Yuxing , Jia Shuo , Wang Weijian , Zhang Pei , Xu Hui , Liu Huan , Gao Liangshu , Lin Yanluan , Li Mingxin , Zhai Panmao
Published: April 2018

Based on 55 years (from 1961 to 2015) of ground‐based hailstorm and atmospheric sounding observations, the climatological characteristics of hailstorms in China, along with potential influencing factors, were analysed. We found that hailstorms exhibit large spatial and temporal variability, with the peak occurring in spring in south China, and in summer in north China. The Tibetan Plateau (TTP) is a region with high hailstorm frequency. Overall, the frequency of hailstorms has decreased over the 55 years, although there was an increase from 1961 to 1985. In terms of diurnal variability, while hailstorm frequency peaks in the afternoon in most of China, it peaks during the night or early morning in southwest China. The magnitude of the peak increased during the 1960s and 1970s, and then decreased afterwards. Hailstorms are negatively correlated with daily mean temperature but are positively correlated with diurnal temperature range, convective available potential energy (CAPE) and totals–totals index. The increase of hailstorms during the period from 1961 to 1985 is mainly correlated with the increase in CAPE over the TTP region, while the decrease of hailstorms afterwards is correlated with all four convective parameters. The finding has significant implications for the potential impact of increasing greenhouse gases on climatological changes in hailstorm.
Changes in oxidative stability and protein profile of flaxseeds resulting from thermal pre‐treatment
Authors: Waszkowiak Katarzyna , Mikołajczak Beata , Kmiecik Dominik
Published: April 2018

BACKGROUND

The oxidative stability of oilseeds is crucial for their technological/nutritional quality and shelf life. This research aimed to evaluate the effect of thermal pre‐treatment (steaming and roasting under various time/temperature conditions) on flaxseed oil and protein stability. The monitoring of changes in oil oxidation in situ and protein profiles (SDS‐PAGE) and analysis of the antiradical activity of ethanolic and aqueous fractions were included in the study.

RESULTS

Flaxseed stability during storage was considerably affected by thermal pre‐treatment conditions. Dynamics of oil oxidation was accelerated at 160 °C and 180 °C but slowed at 200 °C. Influence of pre‐treatment conditions on the antiradical activity of the aqueous fraction was clearly observed and no effect concerning the ethanolic fraction was found. The most significant changes in protein profile of 200 °C‐roasted flaxseed were found with the observed disappearance of 19 kDa protein. A treatment‐dependent decrease in the 13 kDa protein was also detected. Based on the aqueous extract protein profiles, roasting conditions were found to be crucial for protein extractability.

CONCLUSIONS

The study has broadened knowledge of the consequences of flaxseed thermal treatment. The deterioration of flaxseed oil oxidative stability is shown. The changes of 19 and 13 kDa proteins suggest their sensitivity to thermally induced aggregation and/or cross‐link. © 2018 Society of Chemical Industry
Preparation and physicochemistry properties of smart edible films based on gelatin–starch nanoparticles
Authors: Tao Furong , Shi Chengmei , Cui Yuezhi
Published: April 2018

BACKGROUND

Among the natural polymers able to form edible films, starch and gelatin (Gel) are potential sources. Corn starch is a polysaccharide widely produced around the world, and gelatin differs from other hydrocolloids as a fully digestible protein, containing nearly all the essential amino acids, except tryptophan. Based on this, with advantages such as abundance, relatively low cost, biodegradability, and edibility, studies considering alternative systems for food protection that utilize biopolymers have increased significantly in recent years.

RESULTS

A novel macromolecular crosslinker starch–BTCAD–NHS (starch–butanetetracarboxylic acid dianhydride–N‐hydroxysuccinimide, SBN) was successfully prepared to modify gelatin film. Compared with the blank gelatin films, the resulting SBN–Gel films exhibited improved surface hydrophobicity, higher tense strength and elongation‐at‐break, lower Young's modulus values, greater opacity, poorer water vapour uptake properties and better anti‐degradation capacity.

CONCLUSION

The modified gelatin film material with advanced properties obtained in this work was safe, stable eco‐friendly and biorefractory, and was an ideal choice to form packaging in the food industry. Also, the crosslinking SBN–Gel coating was effective in reducing corruption and extending the shelf life of peeled apple substantially. © 2018 Society of Chemical Industry
Physicochemical evaluation of low‐fat yoghurt produced with microbial transglutaminase
Authors: García‐Gómez Belén , Romero‐Rodríguez Ángeles , Vázquez‐Odériz Lourdes , Muñoz‐Ferreiro Nieves , Vázquez Manuel
Published: April 2018

BACKGROUND

Currently consumers demand low‐fat or non‐fat yoghurt but their physical properties are less attractive than those of full‐fat yoghurt. It was reported that microbial transglutaminase (TG) can be used in the production of low‐fat yoghurt. The aim of this work was to evaluate the effect of TG on low‐fat yoghurt to improve their physicochemical and textural properties to approach to those of full‐fat yoghurt. Two TG application methods (addition before fermentation or simultaneous addition with the starter), three dose levels and TG origin were evaluated. Results were compared with commercial low‐fat and full‐fat yoghurts.

RESULTS

No significant differences between application methods were observed. Simultaneous addition of TG was preferred because additional time‐consuming steps are not required. The best dose was 1 U TG g−1 of protein that allowed a firmness higher (4.25 N) than that of commercial low‐fat (3.05 N) and full‐fat (4.43 N) yoghurts to be achieved. This implies that intermediate values of TG will permit the same firmness as commercial yoghurts to be obtained. It was observed some differences by the TG origin may be due to excipients.

CONCLUSION

TG may be used to replace stabilizers in the production of low‐fat yoghurt as it improves texture and avoids initial syneresis. © 2018 Society of Chemical Industry
Effect of LED irradiation on the ripening and nutritional quality of postharvest banana fruit
Authors: Huang Jen‐Yi , Xu Fengying , Zhou Weibiao
Published: April 2018

BACKGROUND

With the ability to tailor wavelengths necessary to the photosynthetically active radiation spectrum of plant pigments, light‐emitting diodes (LEDs) offer vast possibilities in horticultural lighting. The influence of LED light irradiation on major postharvest features of banana was investigated. Mature green bananas were treated daily with selected blue (464–474 nm), green (515–525 nm) and red (617–627 nm) LED lights for 8 days, and compared with non‐illuminated control.

RESULTS

The positive effect of LED lighting on the acceleration of ripening in bananas was greatest for blue, followed by red and green. Under the irradiation of LED lights, faster peel de‐greening and flesh softening, and increased ethylene production and respiration rate in bananas were observed during storage. Furthermore, the accumulations of ascorbic acid, total phenols, and total sugars in banana fruit were enhanced by LED light exposure.

CONCLUSION

LED light treatment can induce the ripening of bananas and improve their quality and nutrition potential. These findings might provide new chemical‐free strategies to shorten the time to ripen banana after harvest by using LED light source. © 2018 Society of Chemical Industry
Quantification of free sugars, fructan, pungency and sweetness indices in onion populations by FT‐MIR spectroscopy
Authors: Clark Christopher J , Shaw Martin L , Wright Kathryn M , McCallum John A
Published: April 2018

Background

To facilitate faster phenotyping of onions (Allium cepa L.), Fourier‐transform mid infrared (FT‐MIR) spectroscopy with partial least squares (PLS) regression modelling was evaluated for the determination of pungency (pyruvate), sweetness (free sugars) and fructan in juice samples (n = 605) expressed from bulbs from breeding populations.

Results

Fourier‐transform infrared (FTIR) spectra (range 1700–900 cm−1) were obtained from droplets (30 μL) of unprocessed juice. Goodness‐of‐fit (r2) and prediction errors (standard error of cross validation) for optimal PLS models were: soluble solids (0.997, 0.1 °Brix), pyruvate [0.825, 0.8 μmol g−1 fresh weight (FW)], fructan (0.98, 1.9 mg g−1 FW), glucose (0.941, 1.1 mg g−1 FW), fructose (0.967, 1.0 mg g−1 FW) and sucrose (0.919, 1.7 mg g−1 FW). FTIR models for industry sweetness indices based on glucose or sucrose equivalents were also developed. Because of its very low concentration (0.8–12 μmol g−1 FW) relative to other compounds, pyruvate was the weakest model developed. Fructan could be determined spectroscopically without the need for enzymatic digestion.

Conclusions

All of the chemometric models developed are acceptable for screening purposes. Those for soluble solids, fructan and fructose are also suitable for routine analysis. FT‐MIR can therefore be utilised for the simultaneous determination of pungency, sweetness and fructan in this crop. © 2018 Society of Chemical Industry
Paclitaxel‐Loaded Polylactide/Polyethylene Glycol Fibers with Long‐Term Antitumor Activity as a Potential Drug Carrier for Local Chemotherapy
Authors: Plch Johana , Venclikova Kristyna , Janouskova Olga , Hrabeta Jan , Eckschlager Tomas , Kopeckova Katerina , Hampejsova Zuzana , Bosakova Zuzana , Sirc Jakub , Hobzova Radka
Published: April 2018

Local application of anticancer agents prolongs the presence time and increases the concentration of drug in the target place and therefore may reduce serious side effects compared to drug systemic administration. The preparation of fibrous materials of polylactide (PLA) and polyethylene glycol (PEG) loaded with paclitaxel (PTX, 1 or 10 wt%) is presented. Scanning electron microscopy proves that PTX is homogeneously incorporated into the fibers. The addition of PEG of various molecular weights (6, 20, or 35 kDa) ensures the release of significantly higher amounts of hydrophobic PTX in a prolonged release time compared to the fibers containing PTX only. Present PLA‐PEG fibrous carriers can serve as a drug depot for PTX since they exhibit significant toxicity for cancer cell lines in several‐day experiment. They are promising for local recurrence therapy, where the initial release is efficient to kill tumor cells and continued release can prevent their subsequent proliferation.
Self‐Assembly and Responsive Behavior of Poly(peptide)‐Based Copolymers
Authors: Kumar Avneesh , Hertel Brigitte , Müllen Klaus
Published: April 2018

Well‐defined copolymers synthesized by combining poly(ethylene glycol) (PEG) and amino acid based building blocks are investigated with regard to their helical rigidity and self‐assembly. Optical active block copolymers reported here are designed to have a pendant amino acid and polymerizable group, that is, isonitrile in order to induce helix formation and reduce the mobility of polymer chains by forming a hydrogen bond network so that a helix with reasonable rigidity can be obtained. Due to the amphiphilicity and a relatively shorter PEG as a coil, these polymers form micelles as observed under transmission electron microscopy in which copolymers PEG108‐b‐PPIC764 and PEG108‐b‐PPIC1020 appear to be evolving into nanoparticles with a size distribution of 100–200 nm. Circular dichroism spectroscopy is employed to study the nature of the helix and its rigidity. The folding and unfolding of polymer helix as a result of the ability of a selective solvent to form/disrupt hydrogen bonds with the peptide linkage is also discussed to highlight the responsive nature of the polymer.
ICAR ATRP in PEG with Low Concentration of Cu(II) Catalyst: A Versatile Method for Synthesis of Block Copolymer Nanoassemblies under Dispersion Polymerization
Authors: Wang Yixin , Han Guang , Duan Wenfeng , Zhang Wangqing
Published: April 2018

A versatile method for synthesis of block copolymer nanoassemblies via initiators for continuous activator regeneration (ICAR) atom transfer radical polymerization (ATRP) dispersion polymerization in a low molecular weight poly(ethylene glycol) (PEG) is discussed. This ICAR ATRP dispersion polymerization uses a low concentration of CuBr2 catalyst, which is stable under atmospheric conditions and is soluble in most polar solvents and employs a polymerization medium of viscous and nonvolatile PEG. Through this ICAR ATRP dispersion polymerization, various block copolymer nanoassemblies, including poly(ethylene glycol)‐block‐polystyrene, poly(ethylene glycol)‐block‐poly(methyl methacrylate), and poly(2‐hydroxypropyl methacrylate)‐block‐poly(methyl methacrylate), have been synthesized. The parameters affecting the size and morphology of the block copolymer nanoassemblies are briefly discussed.
Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2013–2014
Authors: Harvey David J.
Published: April 2018

This review is the eighth update of the original article published in 1999 on the application of Matrix‐assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo‐ and poly‐ saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353–491, 2018.
Quantitative susceptibility mapping of articular cartilage: Ex vivo findings at multiple orientations and following different degradation treatments
Authors: Nykänen Olli , Rieppo Lassi , Töyräs Juha , Kolehmainen Ville , Saarakkala Simo , Shmueli Karin , Nissi Mikko J.
Published: April 2018

Purpose

We investigated the feasibility of quantitative susceptibility mapping (QSM) for assessing degradation of articular cartilage by measuring ex vivo bovine cartilage samples subjected to different degradative treatments. Specimens were scanned at several orientations to study if degradation affects the susceptibility anisotropy. T2*‐mapping, histological stainings, and polarized light microscopy were used as reference methods. Additionally, simulations of susceptibility in layered geometry were performed.

Methods

Samples (n = 9) were harvested from the patellae of skeletally mature bovines. Three specimens served as controls, and the rest were artificially degraded. MRI was performed at 9.4T using a 3D gradient echo sequence. QSM and T2* images and depth profiles through the centers of the samples were compared with each other and the histological findings. A planar isotropic model with depth‐wise susceptibility variation was used in the simulations.

Results

A strong diamagnetic contrast was seen in the deep and calcified layers of cartilage, while T2* maps reflected the typical trilaminar structure of the collagen network. Anisotropy of susceptibility in cartilage was observed and was found to differ from the T2* anisotropy. Slight changes were observed in QSM and T2* following the degradative treatments. In simulations, anisotropy was observed.

Conclusions

The results suggest that QSM is not sensitive to cartilage proteoglycan content, but shows sensitivity to the amount of calcification and to the integrity of the collagen network, providing potential for assessing osteoarthritis. The simulations suggested that the anisotropy of susceptibility might be partially explained by the layered geometry of susceptibility in cartilage.
Radial Basis Function methods—reduced computational expense by exploiting symmetry
Authors: Sarra Scott A.
Published: April 2018

Radial basis function (RBF) methods are popular methods for scattered data interpolation and for solving PDEs in complexly shaped domains. RBF methods are simple to implement as they only require elementary linear algebra operations. In this work, center locations that result in matrices with a centrosymmetric structure are examined. The resulting matrix structure can be exploited to reduce computational expense and improve the accuracy of the methods while avoiding more complicated techniques such as domain decomposition.
Analysis of second order and unconditionally stable BDF2‐AB2 method for the Navier‐Stokes equations with nonlinear time relaxation
Authors: Isik Osman Rasit , Yuksel Gamze , Demir Bulent
Published: April 2018

In this study, we first consider a second order time stepping finite element BDF2‐AB2 method for the Navier‐Stokes equations (NSE). We prove that the method is unconditionally stable and accurate. Second, we consider a nonlinear time relaxation model which consists of adding a term “” to the Navier‐Stokes Equations with the algorithm depends on BDF2‐AB2 method. We prove that this method is unconditionally stable, too. We applied the BDF2‐AB2 method to several numeral experiments including flow around the cylinder. We have also applied BDF2‐AB2 method with nonlinear time relaxation to some problems. It is observed that when the equilibrium errors are high, applying BDF2‐AB2 with nonlinear time relaxation method to the problem yields lower equilibrium errors.
Mitochondrial Respiration is Associated with Lower Energy Expenditure and Lower Aerobic Capacity in African American Women
Authors: Toledo Frederico G.S. , Dubé John J. , Goodpaster Bret H. , Stefanovic‐Racic Maja , Coen Paul M. , DeLany James P.
Published: April 2018

Objective

Reasons for the higher obesity prevalence in African American women (AAW) compared with Caucasian women (CW) are unknown. Energy expenditure and maximal aerobic capacity (VO2max) are lower in AAW. It was hypothesized that these differences are explained by skeletal muscle characteristics, particularly mitochondrial content and function.

Methods

Multivariate regression analyses were used to examine the relationships between energy expenditure (resting and during a hyperinsulinemic‐euglycemic clamp) and VO2max versus body composition, physical activity, and skeletal muscle mitochondrial measurements in AAW and CW.

Results

In AAW, VO2max was lower (P < 0.0001). Body‐composition‐adjusted energy expenditure during the clamp was lower in AAW (P < 0.002). Physical activity was similar in both groups. After adjusting for mitochondrial respiration, racial differences in energy expenditure and VO2max were no longer present. Another novel finding was that a thermogenic response to the clamp was observed in CW (+53 ± 22 kcal/d; P < 0.03) but not in AAW (−19 ± 24 kcal/d; P = 0.43).

Conclusions

AAW and CW show differences in adjusted energy expenditure and aerobic capacity that are largely accounted for by differences in skeletal muscle mitochondrial oxidative characteristics. Further research is needed to determine whether lower mitochondrial respiration and lower thermogenesis are risk factors for obesity in AAW.
Using prescription claims to detect aberrant behaviors with opioids: comparison and validation of 5 algorithms
Authors: Rough Kathryn , Huybrechts Krista F. , Hernandez‐Diaz Sonia , Desai Rishi J. , Patorno Elisabetta , Bateman Brian T.
Published: April 2018

Objective

Compare and validate 5 algorithms to detect aberrant behavior with opioids: Opioid Misuse Score, Controlled Substance‐Patterns of Utilization Requiring Evaluation (CS‐PURE), Overutilization Monitoring System, Katz, and Cepeda algorithms.

Study Design and Setting

We identified new prescription opioid users from 2 insurance databases: Medicaid (2000‐2006) and Clinformatics Data Mart (CDM; 2004‐2013). Patients were followed 1 year, and aberrant opioid behavior was defined according to each algorithm, using Cohen's kappa to assess agreement. Risk differences were calculated comparing risk of opioid‐related adverse events for identified aberrant and nonaberrant users.

Results

About 3.8 million Medicaid and 4.3 million CDM patients initiated prescription opioid use. Algorithms flagged potential aberrant behavior in 0.02% to 12.8% of initiators in Medicaid and 0.01% to 7.9% of initiators in CDM. Cohen's kappa values were poor to moderate (0.00 to 0.50 in Medicaid; 0.00 to 0.30 in CDM). Algorithms varied substantially in their ability to predict opioid‐related adverse events; the Overutilization Monitoring System had the highest risk differences between aberrant and nonaberrant users (14.0% in Medicaid; 13.4% in CDM), and the Katz algorithm had the lowest (0.96% in Medicaid; 0.47% in CDM).

Conclusions

In 2 large databases, algorithms applied to prescription data had varying accuracy in identifying increased risk of adverse opioid‐related events.
Effect of hydroxyl‐terminated poly(fluoroalkyl methacrylate) main‐chain length on the microphase separation of waterborne fluorinated polyurethane
Authors: Yang Wei , Pan Peiting , Wang Haibo , Cheng Xu , Du Zongliang
Published: April 2018

Waterborne fluorinated polyurethanes (WFPUs) based on hydroxyl‐terminated poly(fluoroalkyl methacrylate)s (HTPFMAs) with different main‐chain lengths were synthesized. The structure of HTPFMA was characterized using1H NMR spectroscopy, measurements of hydroxyl values and gel permeation chromatography. The microstructures of WFPUs were investigated using Fourier transform infrared spectroscopy, which indicated that hydrogen bonding interactions in hard segments of WFPUs were enhanced by the introduction of HTPFMA and increased with increasing main‐chain length of HTPFMA. The results of X‐ray diffraction demonstrated that increasing the main‐chain length of HTPFMA resulted in an increase of crystallinity in hard segments. Differential scanning calorimetry revealed that the melting temperature of micro‐crystallites in hard segments and the microphase separation increased with an increase of HTPFMA main‐chain length. Dynamic mechanical analysis and scanning electron microscopy also confirmed that HTPFMA with longer main‐chain length can promote the extent of microphase separation of WFPUs between soft and hard domains. The mechanical properties of WFPUs were improved due to the increase of microphase separation with increasing HTPFMA main‐chain length. © 2018 Society of Chemical Industry
Mass Spectrometry Imaging of 3D Tissue Models
Authors: Russo Cristina , Lewis Emily E. L. , Flint Lucy , Clench Malcolm R.
Published: April 2018

A 3D cell culture is an artificially created environment in which cells are permitted to grow/interact with their surroundings in all three dimensions. Derived from 3D cell culture, organoids are generally small‐scale constructs of cells that are fabricated in the laboratory to serve as 3D representations of in vivo tissues and organs. Due to regulatory, economic and societal issues concerning the use of animals in scientific research, it seems clear that the use of 3D cell culture and organoids in for example early stage studies of drug efficacy and toxicity will increase. The combination of such 3D tissue models with mass spectrometry imaging provides a label‐free methodology for the study of drug absorption/penetration, drug efficacy/toxicity, and drug biotransformation. In this article, some of the successes achieved to date and challenges to be overcome before this methodology is more widely adopted are discussed.
Shape‐Tunable Selective Synthesis of Bismuth Fluoride Nanostructures for Versatile Applications
Authors: Bharat L. Krishna , Nagaraju Goli , Raju G. Seeta Rama , Han Young‐Kyu , Yu Jae Su
Published: April 2018

A facile approach for shape‐tunable synthesis of bismuth fluoride nanoparticles is reported. The approach is based on the homogeneous precipitation of precursor materials in mixed solvents (H2O and ethylene glycol) and only ethylene glycol. The influencing factors on the morphology of the particles, i.e., solvent ratio, F/Bi ratio, and ethylenediaminetetraacetic acid, are studied in detail, and are schematically illustrated. The morphology, crystallinity, structure, and optical properties of the prepared samples are characterized by using a field‐emission scanning electron microscope, transmission electron microscope, X‐ray diffractometer, Fourier transform infrared spectrometer, and spectrofluorometer, respectively. The hollow sphere‐shaped nanoparticle doped with Eu3+ ions exhibit reddish orange emission under ultraviolet illumination due to the symmetric environment around the dopant ions. Subsequently, the effect of dopant concentration on the optical properties is also evaluated. The temperature‐dependent photoluminescence emission spectra reveal good thermal stability. The obtained results provide an efficient strategy for synthesizing the shape‐tunable nanoparticles with excellent optical properties.
Tracheal aspirate VEGF and sphingolipid metabolites in the preterm infant with later development of bronchopulmonary dysplasia
Authors: Hendricks‐Muñoz Karen D. , Xu Jie , Voynow Judith A.
Published: April 2018

Objective

Vascular endothelial growth factor (VEGF) and sphingolipid metabolites, sphingosine 1‐phosphate (S1P), and ceramides are important to lung development and repair. We hypothesized specific sphingolipid and VEGF alterations would be associated with BPD development and aimed to investigate the early tracheal aspirate (TA) VEGF and S1P relationship with later diagnosis of preterm infant bronchopulmonary dysplasia, BPD.

Design

TA VEGF and lipidomics were measured in TA from Infants <32 weeks gestational age at birth with and without later BPD. BPD was defined using the NICHD severity BPD definition. Clinical demographics and medical course were identified with statistical analysis performed with JMP, Statistical Analysis Software.

Results

The analysis included 25 infants (9 NoBPD and 16 BPD) with mean gestational age of 27.8 ± 2.5 SD weeks and 25.1 ± 1.9 SD weeks respectively, P < 0.01. Later development of BPD was associated with elevated mean TA VEGF 604.3 ± 150.2 SE pg/mL versus NoBPD 120 ± 34.3 SE pg/mL, elevated S1P, 11.5 ± 2.3 SE pmol/mL versus NoBPD 4.8 ± 0.6 SE pmol/mL, and elevated selected ceramides during the first week of life.

Conclusions

Airway VEGF and sphingolipid metabolites were distinctly elevated within the first days of postnatal life in preterm infants with later BPD progression. These biomarkers may be useful as indicators of lung injury development or as targets to decrease BPD risk.