bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial patterns of the frog Oophaga pumilio in a plantation system are consistent with conspecific attraction
Authors: Folt Brian , Donnelly Maureen A. , Guyer Craig
Published: February 2018

The conspecific attraction hypothesis predicts that individuals are attracted to conspecifics because conspecifics may be cues to quality habitat and/or colonists may benefit from living in aggregations. Poison frogs (Dendrobatidae) are aposematic, territorial, and visually oriented—three characteristics which make dendrobatids an appropriate model to test for conspecific attraction. In this study, we tested this hypothesis using an extensive mark‐recapture dataset of the strawberry poison frog (Oophaga pumilio) from La Selva Biological Station, Costa Rica. Data were collected from replicate populations in a relatively homogenous Theobroma cacao plantation, which provided a unique opportunity to test how conspecifics influence the spatial ecology of migrants in a controlled habitat with homogenous structure. We predicted that (1) individuals entering a population would aggregate with resident adults, (2) migrants would share sites with residents at a greater frequency than expected by chance, and (3) migrant home ranges would have shorter nearest‐neighbor distances (NND) to residents than expected by chance. The results were consistent with these three predictions: Relative to random simulations, we observed significant aggregation, home‐range overlap, and NND distribution functions in four, five, and six, respectively, of the six migrant–resident groups analyzed. Conspecific attraction may benefit migrant O. pumilio by providing cues to suitable home sites and/or increasing the potential for social interactions with conspecifics; if true, these benefits should outweigh the negative effects of other factors associated with aggregation. The observed aggregation between migrant and resident O. pumilio is consistent with conspecific attraction in dendrobatid frogs, and our study provides rare support from a field setting that conspecific attraction may be a relevant mechanism for models of anuran spatial ecology.
Florivory indirectly decreases the plant reproductive output through changes in pollinator attraction
Authors: Tsuji Kaoru , Ohgushi Takayuki
Published: February 2018

Species often interact indirectly with each other via their traits. There is increasing appreciation of trait‐mediated indirect effects linking multiple interactions. Flowers interact with both pollinators and floral herbivores, and the flower‐pollinator interaction may be modified by indirect effects of floral herbivores (i.e., florivores) on flower traits such as flower size attracting pollinators. To explore whether flower size affects the flower‐pollinator interaction, we usedEurya japonicaflowers. We examined whether artificial florivory decreased fruit and seed production, and also whether flower size affected florivory and the number of floral visitors. The petal removal treatment (i.e., artificial florivory) showed approximately 50% reduction in both fruit and seed set in natural pollination but not in artificial pollination. Furthermore, flower size increased the number of floral visitors, although it did not affect the frequency of florivory. Our results demonstrate that petal removal indirectly decreased 75% of female reproductive output via decreased flower visits by pollinators and that flower size mediated indirect interactions between florivory and floral visitors.
As–N and As–N–P Cage Compounds Generated by [2+2] Addition of Diazenes and Diphosphenes to Diarsadiazanediyls
Authors: Bresien Jonas , Hinz Alexander , Schulz Axel , Villinger Alexander
Published: February 2018

The isolation of binary As–N and ternary As–N–P cage compounds consisting exclusively of group 15 elements was achieved by exploiting the reactivity of diarsadiazanediyl. This arsenic centered biradical is capable of activating and/or quenching small molecules bearing double bonds such as diazenes, Ph–N=N–Ph, or in situ generated labile diphosphenes, e.g. Ph–P=P–Ph, leading to the formation of hexapnicta‐[2.1.1]bicyclohexanes.
Olefination with Sulfonyl Halides and Esters: E‐Selective Synthesis of Alkenes from Semistabilized Carbanion Precursors
Authors: Górski Bartosz , Basiak Dariusz , Talko Alicja , Basak Tymoteusz , Mazurek Tomasz , Barbasiewicz Michał
Published: February 2018

Carbanions of sulfonyl halides and activated sulfonates add to carbonyl compounds, and so‐formed aldol‐type adducts spontaneously fragment into olefins. This transformation mimics the one‐pot Julia olefination with (hetero)aryl sulfones, but the mechanism of fragmentation involves a four‐membered intermediate, typical for reactivity of phosphorus reagents. Moreover, in contrast to the reactions of sulfones, sulfonates of fluorinated alcohols (TFE and HFI) produce byproducts that are easily removed during workup. In our report, we focus on reactions of unstabilized and semistabilized carbanion precursors: alkylsulfonates, and allyl‐ and benzylsulfonates, respectively. In particular for semistabilized systems, olefins were synthesized as predominant E isomers in good yields. The presented studies reveal that optimal reaction conditions, including the type of base and alcohol groups of the sulfonates, are different depending on stabilization of the carbanion precursors and structure of the carbonyl substrates. The practical synthetic guide is supplemented with a discussion of the mechanism, based on reactivity studies of intermediates and identification of side‐products.
Supplement comprising of laccase and citric acid as an alternative for antibiotics: In vitro triggers of melanin production
Authors: Chaali Mona , Lecka Joanna , Suresh Gayatri , Salem Mabrouka , Brar Satinder Kaur , Hernandez‐Galan Leticia , Sévigny Jean , Avalos‐Ramirez Antonio
Published: February 2018

An indiscriminate use of antibiotics in humans and animals has led to the widespread selection of antibiotic‐resistance, thus constricting the use of antibiotics. A possible solution to counter this problem could be to develop alternatives that can boost the host immunity, thus reducing the quantity and frequency of antibiotic use. In this work, for the first time, citric acid and laccase were used as extracellular inducers of melanin production in yeast cells and human cell lines. It is proposed that the formulation of laccase and citric acid together could further promote melatonin‐stimulated, melanocyte‐derived melanin production. Melanization as a probe of immunity described in this study, is an easy and a rapid test compared to other immunity tests and it allows performing statistical analyses. The results showed the synergistic effect of citric acid and laccase on melanin production by yeast cells, with significant statistical differences compared to all other tested conditions (p: 0.0005–0.005). Laccase and citric acid together boosted melanin production after 8 days of incubation. An increase in melanin production by two human colon cells lines (Cacao‐2/15 and HT‐29) was observed on supplementation with both laccase and citric acid in the cell growth medium. Produced melanin showed antimicrobial properties similar to antibiotics. Therefore, a formulation with citric acid and laccase may prove to be an excellent alternative to reduce the antibiotic use in human and animal subjects.
What does the tail of the distribution of current stock prices tell us about future economic activity?
Authors: Vicente José , Araujo Gustavo
Published: February 2018

This paper proposes three leading indicators of economic conditions estimated using current stock returns. The assumption underlying our approach is that current asset prices reflect all the available information about future states of economy. Each of the proposed indicators is related to the tail of the cross‐sectional distribution of stock returns. The results show that the leading indicators have strong correlation with future economic conditions and usually make better out‐of‐sample predictions than two traditional competitors (random walk and the average of previous observations). Furthermore, quantile regressions reveal that the leading indicators have strong connections with low future economic activity.
Activating transcription factor 6α deficiency exacerbates oligodendrocyte death and myelin damage in immune‐mediated demyelinating diseases
Authors: Stone Sarrabeth , Wu Shuangchan , Jamison Stephanie , Durose Wilaiwan , Pallais Jean Pierre , Lin Wensheng
Published: February 2018

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) play a critical role in immune‐mediated demyelinating diseases, including multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE), by regulating the viability of oligodendrocytes. Our previous studies show that activation of the PERK branch of the UPR protects myelinating oligodendrocytes against ER stress in young, developing mice that express IFN‐γ, a key pro‐inflammatory cytokine in MS and EAE, in the CNS. Several studies also demonstrate that PERK activation preserves oligodendrocyte viability and function, protecting mice against EAE. While evidence suggests activation of the ATF6α branch of the UPR in oligodendrocytes under normal and disease conditions, the effects of ATF6α activation on oligodendrocytes in immune‐mediated demyelinating diseases remain unknown. Herein, we showed that ATF6α deficiency had no effect on oligodendrocytes under normal conditions. Interestingly, we showed that ATF6α deficiency exacerbated ER stressed‐induced myelinating oligodendrocyte death and subsequent myelin loss in the developing CNS of IFN‐γ‐expressing mice. Moreover, we found that ATF6α deficiency increased EAE severity and aggravated EAE‐induced oligodendrocyte loss and demyelination, without affecting inflammation. Thus, these data suggest the protective effects of ATF6α activation on oligodendrocytes in immune‐mediated demyelinating diseases.
Sensorimotor network alterations in children and youth with prenatal alcohol exposure
Authors: Long Xiangyu , Little Graham , Beaulieu Christian , Lebel Catherine
Published: February 2018

Children with prenatal alcohol exposure (PAE) often have impaired sensorimotor function. While altered brain structure has been noted in sensorimotor areas, the functional brain alterations remain unclear. This study aims to investigate sensorimotor brain networks in children and youth with PAE using resting‐state functional magnetic resonance imaging (rs‐fMRI). A parcellation‐based network analysis was performed to identify brain networks related to hand/lower limb and face/upper limb function in 59 children and youth with PAE and 50 typically developing controls. Participants with PAE and controls had similar organization of the hand and face areas within the primary sensorimotor cortex, but participants with PAE had altered functional connectivity (FC) between the sensorimotor regions and the rest of the brain. The sensorimotor regions in the PAE group showed less connectivity to certain hubs of the default mode network and more connectivity to areas of the salience network. Overall, our results show that despite similar patterns of organization in the sensorimotor network, subjects with PAE have increased FC between this network and other brain areas, perhaps suggesting overcompensation. These alterations in the sensorimotor network lay the foundation for future studies to evaluate interventions and treatments to improve motor function in children with PAE.
Sarcomas of the sinonasal tract
Authors: Kauke Martin , Safi Ali‐Farid , Grandoch Andrea , Nickenig Hans‐Joachim , Zöller Joachim , Kreppel Matthias
Published: February 2018

Background

Sinonasal sarcomas are rare and heterogeneous in nature. Continuously collecting data influencing the prognosis is fundamental for optimizing therapeutic assessment of this highly destructive neoplasm.

Methods

We conducted a single‐institution retrospective cohort study considering 27 patients with sinonasal sarcoma.

Results

The overall survival (OS) rates for 1 year and 5 years were calculated as 74% and 36%, respectively. Extent of the primary tumor (P = .010), nodal spread (P = .009), and age (P = .004) significantly reduced the OS. Disease‐free survival (DFS) was significantly reduced by age (P = .003), extent of the primary (P = .006), nodal (P = .004), and hematogenous (P = .048) spread. Multimodal therapy including surgery improved the OS and DFS rates (P < .05).

Conclusion

Prognosis is poor due to late disease recognition. However, multimodal therapeutic regimens, including surgery, may improve the outcome.
A balanced approach to falls prevention: Application in the real world
Authors: Jancey Jonine , Wold Catrina , Meade Rachel , Sweeney Roisin , Davison Erica , Leavy Justine
Published: February 2018

Background

Falls place a heavy burden on the health system, impacting on an individual's quality of life, often resulting in a fear of falling, reduction in independence and at times admission to residential care. This study aimed to determine health professionals’ confidence in discussing falls prevention strategies, topics discussed and the barriers and enablers to falls prevention discussions with clients aged 60 years and over.

Method

A cross‐sectional self‐complete online survey was undertaken with a sample of health professionals (n = 191) who had engaged in the services of the Stay On Your Feet® programs delivered by the Injury Matters in Western Australia (WA).

Results

The majority of participants were physiotherapists (25.7%), registered nurses (17.8%) and occupational therapists (11%) located in metropolitan (56%) and regional (44%) WA. Most health professionals (80.2%) were “highly” confident discussing falls prevention strategies. Discussion of falls prevention included the benefits of strength and balance exercises (83%), eating a healthy diet (78.7%), regular eyesight checks (64.5%), reviewing medications (54.8%) and exposure to sunlight (50.3%). The main enablers to falls prevention were knowledge (89.7%), skills to identify (77.7%) and implement (66.3%) falls prevention strategies, and access to printed resources (74.9%), while the main barrier was appointment times (14.6%).

Conclusion

Health professionals’ indicated that they are confident in discussing falls prevention strategies, and although a range of falls prevention strategies were discussed, limited attention was directed at the pharmacists’ review of medications, eyesight checks and increasing vitamin D levels.

So what?

Health professionals are discussing falls prevention strategies with their clients. A more multifaceted approach should be encouraged with an emphasis on all prevention strategies.
Using stable isotopes 18O and 2H of lake water and biogeochemical analysis to identify factors affecting water quality in four estuarine Amazonian shallow lakes
Authors: da Cunha Alan Cavalcanti , Sternberg Leonel da Silveira Lobo
Published: February 2018

Stable isotopes analyses of oxygen and hydrogen of lake water were used to estimate the effect of evaporation (E) on the water quality of four shallow lakes in the Amapá State coast—Amazon/Brazil. These lakes, with different size and hydrologic conditions, were sampled during the course of the 2015/2016 El‐Niño (record‐breaking warming/drought in the Amazon rainforest). Hydrometeorological and water quality parameters were simultaneously performed to the isotopic sampling. The results showed that the evaporation process and the water quality can be explained by climate season and distances from the Atlantic Ocean. Lake evaporation losses ranged from ≈0–22% during the wet season in April/2016 and ≈35.7% during the dry season in November/2015. As expected, the evaporation of lake water was greater during the dry season, but it was higher for lakes farther away from the Atlantic Ocean compared with more coastal lakes due to tidal preponderance and the influence of major river channels. The more inland estuarine lakes showed a lower level of salinity (0.00–0.03 ppt) compared with those closer to the Atlantic Ocean (0.01–0.08 ppt). The El Niño phenomenon, with a lower precipitation in the Amazon basin, may initiate salinization of lakes closer to the Atlantic Ocean. Furthermore, strong mean seasonal variations of evaporation (0.06 ≤ E ≤ 0.22) and other hydrologic parameters were observed (precipitation, water temperature, and water depth), with significant effects on the water quality such as salinity, dissolved oxygen, chlorophyll (p < .05). We conclude that the occurrence of the extreme climatic events can disrupt the biogeochemical and hydrological balance of these aquatic ecosystems and salinization of lakes closer to the Atlantic Ocean.
Comparison of groundwater age models for assessing nitrate loading, transport pathways, and management options in a complex aquifer system
Authors: Koh Eun‐Hee , Lee Eunhee , Kaown Dugin , Green Christopher T. , Koh Dong‐Chan , Lee Kang‐Kun , Lee Seung Hyun
Published: February 2018

In an aquifer system with complex hydrogeology, mixing of groundwater with different ages could occur associated with various flow pathways. In this study, we applied different groundwater age‐estimation techniques (lumped parameter model and numerical model) to characterize groundwater age distributions and the major pathways of nitrate contamination in the Gosan agricultural field, Jeju Island. According to the lumped parameter model, groundwater age in the study area could be explained by the binary mixing of the young groundwater (4–33 years) and the old water component (>60 years). The complex hydrogeologic regimes and local heterogeneity observed in the study area (multilayered aquifer, well leakage hydraulics) were particularly well reflected in the numerical model. The numerical model predicted that the regional aquifer of Gosan responded to the fertilizer applications more rapidly (mean age: 9.7–22.3 years) than as estimated by other models. Our study results demonstrated that application and comparison of multiple age‐estimation methods can be useful to understand better the flow regimes and the mixing characteristics of groundwater with different ages (pathways), and accordingly, to reduce the risk of improper groundwater management plans arising from the aquifer heterogeneity.
Nitrate in drinking water and colorectal cancer risk: A nationwide population‐based cohort study
Authors: Schullehner Jörg , Hansen Birgitte , Thygesen Malene , Pedersen Carsten B. , Sigsgaard Torben
Published: February 2018

Nitrate in drinking water may increase risk of colorectal cancer due to endogenous transformation into carcinogenic N‐nitroso compounds. Epidemiological studies are few and often challenged by their limited ability of estimating long‐term exposure on a detailed individual level. We exploited population‐based health register data, linked in time and space with longitudinal drinking water quality data, on an individual level to study the association between long‐term drinking water nitrate exposure and colorectal cancer (CRC) risk. Individual nitrate exposure was calculated for 2.7 million adults based on drinking water quality analyses at public waterworks and private wells between 1978 and 2011. For the main analyses, 1.7 million individuals with highest exposure assessment quality were included. Follow‐up started at age 35. We identified 5,944 incident CRC cases during 23 million person‐years at risk. We used Cox proportional hazards models to estimate hazard ratios (HRs) of nitrate exposure on the risk of CRC, colon and rectal cancer. Persons exposed to the highest level of drinking water nitrate had an HR of 1.16 (95% CI: 1.08–1.25) for CRC compared with persons exposed to the lowest level. We found statistically significant increased risks at drinking water levels above 3.87 mg/L, well below the current drinking water standard of 50 mg/L. Our results add to the existing evidence suggesting increased CRC risk at drinking water nitrate concentrations below the current drinking water standard. A discussion on the adequacy of the drinking water standard in regards to chronic effects is warranted.
Derivation of a no‐significant‐risk‐level for tetrabromobisphenol A based on a threshold non‐mutagenic cancer mode of action
Authors: Pecquet Alison M. , Martinez Jeanelle M. , Vincent Melissa , Erraguntla Neeraja , Dourson Michael
Published: February 2018

A no‐significant‐risk‐level of 20 mg day–1 was derived for tetrabromobisphenol A (TBBPA). Uterine tumors (adenomas, adenocarcinomas, and malignant mixed Müllerian) observed in female Wistar Han rats from a National Toxicology Program 2‐year cancer bioassay were identified as the critical effect. Studies suggest that TBBPA is acting through a non‐mutagenic mode of action. Thus, the most appropriate approach to derivation of a cancer risk value based on US Environmental Protection Agency guidelines is a threshold approach, akin to a cancer safe dose (RfDcancer). Using the National Toxicology Program data, we utilized Benchmark dose software to derive a benchmark dose lower limit (BMDL10) as the point of departure (POD) of 103 mg kg–1 day–1. The POD was adjusted to a human equivalent dose of 25.6 mg kg–1 day–1 using allometric scaling. We applied a composite adjustment factor of 100 to the POD to derive an RfDcancer of 0.26 mg kg–1 day–1. Based on a human body weight of 70 kg, the RfDcancer was adjusted to a no‐significant‐risk‐level of 20 mg day–1. This was compared to other available non‐cancer and cancer risk values, and aligns well with our understanding of the underlying biology based on the toxicology data. Overall, the weight of evidence from animal studies indicates that TBBPA has low toxicity and suggests that high doses over long exposure durations are needed to induce uterine tumor formation. Future research needs include a thorough and detailed vetting of the proposed adverse outcome pathway, including further support for key events leading to uterine tumor formation and a quantitative weight of evidence analysis.
Ultrastructural description of the spermatogenesis and spermatozoa in Phaenocora unipunctata (Platyhelminthes, Neotyphloplanida)
Authors: Ponce de León Rodrigo , Volonterio Odile
Published: February 2018

Ultrastructural studies of spermiogenesis and sperm morphology have found many characters that are likely to provide clues to the phylogeny of the Platyhelminthes. However, the lack of information on many free‐living groups has been a limiting factor. There is a single description of the spermatogenesis and spermatozoa in a Phaenocora species, namely P. anomalocoela, therefore a similar analysis was made in Phaenocora unipunctata to compare the intrageneric variation of sperm ultrastructure and spermatogenesis in the Neotyphloplanida. The comparison of the two Phaenocora species shows that several characters have the potential to be relevant to hypothesize phylogenetic relationships at different taxonomic levels. The presence of superficially incorporated axonemes outside the ring of cortical microtubules in the mature sperm cell, resulting from the fusion of the axonemes with the median cytoplasmic process during spermiogenesis, as well as the presence of a constant number of microtubules in the different regions of the spermatozoon, seem to constitute apomorphies of the genus Phaenocora. Furthermore, the presence of an axonemal spur, the compression of cortical microtubules by the rotation of the basal bodies during spermiogenesis, and the presence of a connection between the nucleus and the plasma membrane in the mature spermatozoon, support previous proposals that these characters are apomorphies of Dalytyphloplanida. The comparison of spermatogenesis and spermatozoa of P. unipunctata and P. anomalocoela demonstrates that studying intrageneric variation can give valuable insights into the significance of many characters proposed for phylogenetic studies of the Rhabdocoela.
Free‐breathing dynamic contrast‐enhanced MRI for assessment of pulmonary lesions using golden‐angle radial sparse parallel imaging
Authors: Chen Lihua , Liu Daihong , Zhang Jiuquan , Xie Bing , Zhou Xiaoyue , Grimm Robert , Huang Xuequan , Wang Jian , Feng Li
Published: February 2018

Background

Dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) has been shown to be a promising technique for assessing lung lesions. However, DCE‐MRI often suffers from motion artifacts and insufficient imaging speed. Therefore, highly accelerated free‐breathing DCE‐MRI is of clinical interest for lung exams.

Purpose

To test the performance of rapid free‐breathing DCE‐MRI for simultaneous qualitative and quantitative assessment of pulmonary lesions using Golden‐angle RAdial Sparse Parallel (GRASP) imaging.

Study Type

Prospective.

Population

Twenty‐six patients (17 males, mean age = 55.1 ± 14.4) with known pulmonary lesions.

Field Strength/Sequence

3T MR scanner; a prototype fat‐saturated, T1‐weighted stack‐of‐stars golden‐angle radial sequence for data acquisition and a Cartesian breath‐hold volumetric‐interpolated examination (BH‐VIBE) sequence for comparison.

Assessment

After a dual‐mode GRASP reconstruction, one with 3‐second temporal resolution (3s‐GRASP) and the other with 15‐second temporal resolution (15s‐GRASP), all GRASP and BH‐VIBE images were pooled together for blind assessment by two experienced radiologists, who independently scored the overall image quality, lesion delineation, overall artifact level, and diagnostic confidence of each case. Perfusion analysis was performed for the 3s‐GRASP images using a Tofts model to generate the volume transfer coefficient (Ktrans) and interstitial volume (Ve).

Statistical Tests

Nonparametric paired two‐tailed Wilcoxon signed‐rank test; Cohen's kappa; unpaired Student's t‐test.

Results

15s‐GRASP achieved comparable image quality with conventional BH‐VIBE (P > 0.05), except for the higher overall artifact level in the precontrast phase (P = 0.018). The Ktrans and Ve in inflammation were higher than those in malignant lesions (Ktrans: 0.78 ± 0.52 min−1 vs. 0.37 ± 0.22 min−1, P = 0.020; Ve: 0.36 ± 0.16 vs. 0.26 ± 0.1, P = 0.177). Also, the Ktrans and Ve in malignant lesions were also higher than those in benign lesions (Ktrans: 0.37 ± 0.22 min−1 vs. 0.04 ± 0.04 min−1, P = 0.001; Ve: 0.26 ± 0.12 vs. 0.10 ± 0.00, P = 0.063).

Data Conclusion

This feasibility study demonstrated the performance of high spatiotemporal resolution free‐breathing DCE‐MRI of the lung using GRASP for qualitative and quantitative assessment of pulmonary lesions.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. MAGN. RESON. IMAGING 2018;48:459–468.
An artificial neural network‐based approach for the impedance modeling of piezoelectric energy harvesting devices
Authors: Zhao Sheng , Fu Hai‐Peng
Published: February 2018

In this paper, the equivalent series resistance (ESR) and capacitance (ESC) of piezoelectric energy harvesting devices have been modeled accurately over a wide frequency range for the first time. It is shown that the impedance modeling of the ESR and ESC is demonstrated as an important factor for the design of the Bias Flip (or the parallel synchronized switching harvesting on an inductor) interface circuit, which affects the performance of energy harvesting seriously. The conventional Butterworth‐Van Dyke (BVD) model and the modified BVD model are analyzed to state their imprecise modeling performance. To address this problem, an artificial neural network (ANN) technique with prior knowledge input method is employed to improve the model accuracy of the ESR and ESC. Also, a least‐squares curve fitting method is presented to compare with the ANN model. A good matching has been obtained between the measured and ANN‐predicted ESR and ESC in the frequency range of 2600 to 3600 Hz. The excellent performance on the accuracy of the proposed method is further illustrated through the comparison on the average relative error and maximum relative error with the conventional BVD, modified BVD model, and the curve fitting method.
Nanosecond time‐resolved Raman spectroscopy for solving some Raman problems such as luminescence or thermal emission
Authors: Fotso Gueutue E.S. , Canizares A. , Simon P. , Raimboux N. , Hennet L. , Ammar M.‐R.
Published: February 2018

Raman spectroscopy is experimentally widely available and relatively simple to perform at room temperature. Some difficulties nevertheless remain, as for instance separating some various contributions from the Raman spectrum, such as thermal emission for high temperature measurements or luminescence. Here, an optimized time‐resolved Raman spectroscopy system based on a gated detection and a nanosecond pulsed laser excitation (30 ns width, 532 nm wavelength) is described. The system allows contactless Raman measurements, at high temperatures, of some materials such as zirconia and yttria. An example of Raman spectra collected on yttria at very high temperature up to 2100 °C is provided. This optimized system may also be used to discriminate between Raman scattering and luminescence as demonstrated in zirconia material.
The effect of greenhouse covering materials on phytochemical composition and antioxidant capacity of tomato cultivars
Authors: Ahmadi Latifeh , Hao Xiuming , Tsao Rong
Published: February 2018

BACKGROUND

The effect of light transmission (direct and diffuse) on the phenolic compounds of five tomato cultivars was investigated under controlled conditions in greenhouses covered with different covering materials.

RESULTS

The type of covering material and type of diffusion of light simultaneously affected the reducing power of cultivars. Two‐way analysis of variance showed statistically significant differences in total phenolic content for the different cultivars (P < 0.05) but not for the covering materials. Analysis by ultrahigh‐performance liquid chromatography with diode array detection and liquid chromatography/tandem mass spectrometry showed the presence of major phenolic acid compounds such as chlorogenic acid, hydroxycinnamic acid/rutin, caffeic acid, ferulic acid and coumaric acid as well as flavonoid compounds such as myricetin, quercetin and naringenin. Most of the identified compounds showed a significant difference in different treatments due to both cultivar and covering material (P < 0.05). Statistical analysis showed that the type of covering material used influenced the total carotenoid and lycopene content (P < 0.05); however, the amount of lutein was not influenced by the type of covering material (P > 0.05).

CONCLUSION

This study showed that the use of solar energy transmission could positively affect the reducing power of cultivars and alter the biosynthesis of certain phytochemicals that are health‐beneficial. Further study could lead to applications for producing greenhouse vegetables with greater health attributes. © 2018 Society of Chemical Industry
Graphene‐doped electrochemical copolymer coating of 2,2‐bithiophene and 3‐methylthiophene for the highly effective solid‐phase microextraction of volatile benzene homologues
Authors: Guo Xiafei , Zhao Faqiong , Zeng Baizhao
Published: February 2018

We report the electrochemical fabrication of a poly(2,2‐bithiophene‐co‐3‐methylthiophene)‐graphene composite coating and its application in the headspace solid‐phase microextraction and gas chromatography determination of benzenes (i.e., bromobenzene, 4‐bromotoluene, 2‐nitrotoluene, 3‐nitrotoluene and 1,2,4‐trichlorobenzene). The coating was uniform and showed cauliflower‐like microstructure. It had high thermal stability (up to 375°C) and could be used for at least 180 times of solid‐phase microextraction without a decrease in extraction performance. Furthermore, it presented high extraction capacity for the benzenes due to the hydrophobic effect and π–π interaction between the analytes and the coating. Under optimized extraction conditions, good linearity (correlation coefficients higher than 0.9946), wide linear range (0.01–50 μg/L), and low limits of detection (5.25–12.5 ng/L) were achieved for these analytes. The relative standard deviation was lower than 5.7% for five successive measurements with one fiber, and the relative standard deviation for fiber‐to‐fiber was 4.9–6.8% (n = 5). The solid‐phase microextraction and gas chromatography method was successfully applied for the determination of three real samples, and the recoveries for standards added were 89.6–106% for nail polish, 85.8–110% for hair dye, and 90–106.2% for correction fluid, respectively.
Elution–extrusion countercurrent chromatography separation of six pairs of isomeric iridoids from Cornus officinalis Sieb. et Zucc. guided by ion current extraction in mass spectrometry
Authors: Liang Jinru , Sun Wenji
Published: February 2018

A mass spectrometry–guided elution–extrusion countercurrent chromatography protocol was developed to separate chemical components from Cornus officinalis Sieb. et Zucc. In this study, ion current extraction, a mass spectrometry–based data postacquisition method, was utilized to boost the separation power and scope of countercurrent chromatography technique. As a peak repicking and denoising tool, ion current extraction was carried out to process the liquid chromatography with mass spectrometry and the countercurrent chromatography with mass spectrometry data. So the target components were reacquired in the created extracted ion current patterns with enhanced responses and diminished background noise, which facilitated the distribution constant determination (by liquid chromatography with extracted ion current) and the targets fractionation (by countercurrent chromatography with extracted ion current). Under the guidance of the extracted ion currents of the target components and with the support of elution–extrusion mode in the countercurrent chromatography separation, six pairs of minor iridoid isomers were obtained in shortened experimental duration. Besides, a reciprocal shifted symmetry plot was established to represent the elution–extrusion countercurrent chromatography chromatogram. The results demonstrated the capability of the ion current extraction–guided elution–extrusion countercurrent chromatography protocol in discovery, analysis, and fractionation of low‐concentration and structurally similar chemicals from a complicated sample.
Large Area, Highly Transparent, and Mechanically Stable Adhesive Films with Tunable Refractive Indices
Authors: Wang Dan , Zhang Jianfu , He Yuanyuan , Li Wenfei , Li Shitao , Fu Xiuhua , Tian Ming , Zhou Yang , Yao Zhanhai
Published: February 2018

Optical bonding with both excellent mechanical and optical properties is highly desirable for many advanced optical device applications. This paper presents a facile method for fabricating large‐area, highly transparent, and mechanically stable adhesive films with a tunable refractive index (RI) by the layer‐by‐layer (LbL) assembly of cationic branched poly(ethylenimine) (PEI) and an anionic blend of poly(acrylic acid) (PAA) and poly(4‐styrenesulfonic acid) (PSS). Scanning electron microscopy and atomic force microscopy studies indicate that the resulting (PEI/PAA–PSS)*n adhesive films with n PEI/PAA–PSS deposition layers are smooth and homogeneous. A satisfactory bonding strength is demonstrated for both two‐sided and one‐sided bonding methods, which provide a bonding strength greater than 5.71 ± 0.71 MPa. A linearly tunable RI from 1.5410 to 1.5792 is achieved with a transparency greater than 94% in the visible region. Moreover, the preparation and debonding of adhesive films can be conducted in water, which is convenient and environmentally friendly.
Improving Photovoltaic Performance of a Fused‐Ring Azepinedione Copolymer via a D–A–A Design
Authors: Zhang Honghong , Li Ting , Xiao Zuo , Lei Zhongli , Ding Liming
Published: February 2018

Two conjugated copolymer donors, PTTABDT and PBTTABDT, based on a fused‐ring azepinedione acceptor unit, 5‐(2‐octyldodecyl)‐4H‐thieno[2′,3′:4,5]thieno[3,2‐c]thieno[2′,3′:4,5]thieno[2,3‐e]azepine‐4,6(5H)‐dione (TTA), are prepared. PTTABDT possesses a conventional donor–acceptor (D–A) structure with one TTA in the repeat unit, while PBTTABDT has a D–A–A structure with two TTAs in the repeat unit. Compared with PTTABDT, PBTTABDT shows a deeper highest occupied molecular orbital (HOMO) level, a narrower bandgap, and a higher hole mobility, and exhibits better performance in bulk heterojunction solar cells. Power conversion efficiencies of 6.18% and 7.81% are achieved from PTTABDT:PC71BM and PBTTABDT:PC71BM solar cells, respectively. The higher performance of PBTTABDT:PC71BM solar cells results from the enhanced open‐circuit voltage (V
oc) and short‐circuit current density (  J
sc).
HOXA13 contributes to gastric carcinogenesis through DHRS2 interacting with MDM2 and confers 5‐FU resistance by a p53‐dependent pathway
Authors: Han Yang , Song Chenlong , Wang Jianying , Tang Huamei , Peng Zhihai , Lu Su
Published: February 2018

5‐FU‐based chemotherapy is recently most recommended as the first‐line treatment for gastric cancer (GC). However, 5‐FU resistance is common for many postoperative GC patients. Homeobox A13 (HOXA13) is a member of homeobox genes highly expressed in many human tumors. Its potential roles and mechanisms of resistance to 5‐FU in GC are poorly understood. In this study, we discovered that HOXA13 played an oncogenic role in vivo and in vitro. The patients with HOXA13 overexpression were closely related with poor prognosis and more prone to be resistant to 5‐FU. Moreover, dehydrogenase/reductase 2 (DHRS2) was identified as a downstream gene of HOXA13. HOXA13 played a role of carcinogenesis through directly down‐regulating DHRS2 to increase MDM2. Furthermore, HOXA13 conferred 5‐FU resistance through MRP1 by a p53‐dependent pathway. Therefore, HOXA13 might serve as a potential signature that recognized patients who were insensitive to 5‐FU, and timely recommended them to other chemotherapy regimens.
Performance of the Movement Disorders Society criteria for prodromal Parkinson's disease: A population‐based 10‐year study
Authors: Mahlknecht Philipp , Gasperi Arno , Djamshidian Atbin , Kiechl Stefan , Stockner Heike , Willeit Peter , Willeit Johann , Rungger Gregorio , Poewe Werner , Seppi Klaus
Published: February 2018

Objective: We aimed to identify prodromal Parkinson's disease (PD) and its predictive accuracy for incident PD in an unselected elderly population and to estimate the relevance of this approach for future neuroprotection trials.

Methods: We applied the recently published Movement Disorders Society (MDS) research criteria for prodromal PD to participants of the prospective population‐based Bruneck Study of the 2005 assessment (n = 574, ages 55‐94 years). Cases of incident PD were identified at 3‐year, 5‐year, and 10‐year follow‐up visits. We calculated predictive accuracies of baseline prodromal PD status for incident cases, and, based on them, estimated sample sizes for neuroprotection trials with conversion to PD as the primary outcome.

Results: Baseline status of probable prodromal PD (n = 12) had a specificity in predicting incident PD of 98.8% (95% confidence interval, 97.3%‐99.5%), a sensitivity of 66.7% (29.6%‐90.8%), and a positive predictive value of 40.0% (16.7%‐68.8%) over 3 years. Specificity remained stable with increasing follow‐up time, sensitivity decreased to 54.6% (28.0%‐78.8%) over 5 years and to 35.0% (18.0%‐56.8%) over 10 years, whereas positive predictive value rose to 60.0% (31.2%‐83.3%) and 77.8% (44.3%‐94.7%), respectively. Sample size estimates at 80% power in an intention‐to‐treat approach ranged from 108 to 540 patients with probable prodromal PD depending on trial duration (3‐5 years) and effect size of the agent (30%‐50%).

Conclusions: Our findings show that the MDS criteria for prodromal PD yield moderate to high predictive power for incident PD in a community‐based setting and may thus be helpful to define target populations of future neuroprotection trials. © 2018 International Parkinson and Movement Disorder Society
Modelling the potential impact of limited hospital beds on Ebola virus disease dynamics
Authors: Djiomba Njankou Sylvie Diane , Nyabadza Farai
Published: February 2018

During the 2013‐2015 Ebola virus disease outbreak, admission into a health facility depended on the availability of hospital beds and health personnel. The limited number of such important logistics contributed to the escalation of the epidemic. We use a compartmental model to study the dynamics of Ebola virus disease when there is a limited number of beds for patients. We use a non‐linear hospitalisation rate and formulate the rate at which the time‐dependent number of available beds evolves. The model shows a backward bifurcation. Simulation results show that bed supply in Ebola treatment units contribute to the reduction of the number of individuals infected by Ebola virus. The model fitting results suggest that a timely supply of sufficient beds to Ebola treatment units limits the spread of the disease. Despite the fact that bed supplies to Ebola treatment units are not in themselves a control measure, they contribute to the reduction of the disease spread, by keeping the infectious in one place, during their infectious period.These results have important implications to the management and control of the disease.
Placental perfusion imaging using velocity‐selective arterial spin labeling
Authors: Zun Zungho , Limperopoulos Catherine
Published: February 2018

Purpose

The placenta remains the least understood human organ, in large part because of the lack of noninvasive tools currently available to examine placental function in vivo. This study investigates the feasibility of using velocity‐selective arterial spin labeling (VSASL) to assess placental perfusion.

Methods

In placental perfusion imaging, VSASL was compared with pseudocontinuous ASL (PCASL), which is currently the standard technique in brain arterial spin labeling (ASL). Reproducibility of placental VSASL was evaluated using two repeated scans within the same imaging session. Inflow dependence of placental VSASL was investigated by modulating VSASL signal using maternal inhalation of 100% oxygen and variation of cut‐off velocity. All experiments were performed in healthy pregnant volunteers at 1.5 Tesla.

Results

Apparent placental perfusion measured using PCASL with two different labeling locations was only 16% and 9% of that of VSASL (n = 7; P < 0.01 for both). Placental VSASL was highly reproducible based on within‐subject coefficient of variation of 3.5%, repeatability of 19.7 mL/100 g/min, and intraclass correlation coefficient of 0.97 (n = 14). Placental VSASL was also found to be dependent on blood inflow given that the absolute change in apparent placental perfusion with maternal hyperoxia was significantly larger than that of two repeated scans under normoxia (n = 7; P < 0.01), and there was a significant difference in apparent placental perfusion between different cut‐off velocities (n = 6; P < 0.01).

Conclusion

This study demonstrates the feasibility of noninvasive placental perfusion imaging using VSASL and lays the groundwork for acquiring placental perfusion images in pregnancies at high risk where placental function is impaired.
Demonstration of improved tissue integration and angiogenesis with an elastic, estradiol releasing polyurethane material designed for use in pelvic floor repair
Authors: Shafaat Sarah , Mangir Naside , Regureos Sabiniano R. , Chapple Christopher R. , MacNeil Sheila
Published: February 2018

Aims

Pelvic organ prolapse and stress urinary incontinence affect 40‐50% of postmenopausal women worldwide. Polypropylene meshes have been extensively used for the surgical intervention of these disorders; however, these meshes can lead to severe complications in some patients. The need for synthetic materials more suited for use in pelvic floor repair is widely accepted. This study aims to develop an electrospun 17‐β‐estradiol releasing polyurethane (PU) scaffold that not only provides the appropriate mechanical support but can also stimulate new extracellular matrix (ECM) production and angiogenesis.

Methods

PU scaffolds with and without 17‐β‐estradiol (25 and 50 mg/g) were prepared by blend electrospinning. Mechanical properties of scaffolds were assessed by uniaxial cyclic and non‐cyclic testing. The viability and ECM production of human adipose derived mesenchymal stem cells (hADMSCs) cultured on 17‐β‐estradiol releasing PU scaffolds was evaluated. Angiogenic potential of estradiol releasing scaffolds was demonstrated by using an ex ovo chick chorioallantoic membrane (CAM) assay.

Results

The inclusion of estradiol in PU scaffolds did not change the ultrastructure but it significantly increased the ultimate tensile strength of scaffolds. hADMSCs on estradiol‐releasing PU scaffolds showed more ECM production. The CAM assay revealed a significantly higher angiogenic potential of estradiol‐releasing PU scaffolds with an additive effect seen when hADMSCs cultured on estradiol scaffolds. Histological examination of CAM tissue sections showed extensive cellular infiltration and a good tissue integration for all constructed scaffolds.

Conclusions

This study shows the angiogenic potential of estradiol‐releasing PU scaffolds with appropriate strength and elasticity desirable to support the pelvic floor.
Cortical structural involvement and cognitive dysfunction in early Parkinson's disease
Authors: Klein J.C. , Rolinski M. , Griffanti L. , Szewczyk‐Krolikowski K. , Baig F. , Ruffmann C. , Groves A.R. , Menke R.A.L. , Hu M.T. , Mackay C.
Published: February 2018

Magnetic resonance imaging (MRI) studies in early Parkinson's disease (PD) have shown promise in the detection of disease‐related brain changes in the white and deep grey matter. We set out to establish whether intrinsic cortical involvement in early PD can be detected with quantitative MRI. We collected a rich, multi‐modal dataset, including diffusion MRI, T1 relaxometry and cortical morphometry, in 20 patients with early PD (disease duration, 1.9 ± 0.97 years, Hoehn & Yahr 1–2) and in 19 matched controls. The cortex was reconstructed using FreeSurfer. Data analysis employed linked independent component analysis (ICA), a novel data‐driven technique that allows for data fusion and extraction of multi‐modal components before further analysis. For comparison, we performed standard uni‐modal analysis with a general linear model (GLM). Linked ICA detected multi‐modal cortical changes in early PD (p = 0.015). These comprised fractional anisotropy reduction in dorsolateral prefrontal, cingulate and premotor cortex and the superior parietal lobule, mean diffusivity increase in the mesolimbic, somatosensory and superior parietal cortex, sparse diffusivity decrease in lateral parietal and right prefrontal cortex, and sparse changes to the cortex area. In PD, the amount of cortical dysintegrity correlated with diminished cognitive performance. Importantly, uni‐modal analysis detected no significant group difference on any imaging modality. We detected microstructural cortical pathology in early PD using a data‐driven, multi‐modal approach. This pathology is correlated with diminished cognitive performance. Our results indicate that early degenerative processes leave an MRI signature in the cortex of patients with early PD. The cortical imaging findings are behaviourally meaningful and provide a link between cognitive status and microstructural cortical pathology in patients with early PD.