bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying Biomolecular Binding Constants using Video Paper Analytical Devices
Authors: Miller Benjamin S. , Parolo Claudio , Turbé Valérian , Keane Candice E. , Gray Eleanor R. , McKendry Rachel A. 
Published: May 2018

AbstractA novel ultra‐low‐cost biochemical analysis platform to quantify protein dissociation binding constants and kinetics using paper microfluidics is reported. This approach marries video imaging with one of humankind's oldest materials: paper, requiring no large, expensive laboratory equipment, complex microfluidics or external power. Temporal measurements of nanoparticle–antibody conjugates binding on paper is found to follow the Langmuir Adsorption Model. This is exploited to measure a series of antibody–antigen dissociation constants on paper, showing excellent agreement with a gold‐standard benchtop interferometer. The concept is demonstrated with a camera and low‐end smartphone, 500‐fold cheaper than the reference method, and can be multiplexed to measure ten reactions in parallel. These findings will help to widen access to quantitative analytical biochemistry, for diverse applications spanning disease diagnostics, drug discovery, and environmental analysis in resource‐limited settings.
Structural Analysis of Small‐Molecule Binding to the BAZ2A and BAZ2B Bromodomains
Authors: Dalle Vedove Andrea , Spiliotopoulos Dimitrios , D'Agostino Vito G. , Marchand Jean‐Rémy , Unzue Andrea , Nevado Cristina , Lolli Graziano , Caflisch Amedeo 
Published: May 2018

AbstractThe bromodomain‐containing protein BAZ2A is a validated target in prostate cancer research, whereas the function of its paralogue BAZ2B is still undefined. The bromodomains of BAZ2A and BAZ2B have a similar binding site for their natural ligand, the acetylated lysine side chain. Here, we present an analysis of the binding modes of eight compounds belonging to three distinct chemical classes. For all compounds, the moiety mimicking the natural ligand engages in essentially identical interactions in the BAZ2A and BAZ2B bromodomains. In contrast, the rest of the molecule is partially solvent‐exposed and adopts different orientations with different interactions in the two bromodomains. Some of these differences could be exploited for designing inhibitors with selectivity within the BAZ2 bromodomain subfamily.
Dichlorophenylacrylonitriles as AhR Ligands That Display Selective Breast Cancer Cytotoxicity in vitro
Authors: Baker Jennifer R. , Gilbert Jayne , Paula Stefan , Zhu Xiao , Sakoff Jennette A. , McCluskey Adam 
Published: May 2018

AbstractKnoevenagel condensation of 3,4‐dichloro‐ and 2,6‐dichlorophenylacetonitriles gave a library of dichlorophenylacrylonitriles. Our leads (Z)‐2‐(3,4‐dichlorophenyl)‐3‐(1H‐pyrrol‐2‐yl)acrylonitrile (5) and (Z)‐2‐(3,4‐dichlorophenyl)‐3‐(4‐nitrophenyl)acrylonitrile (6) displayed 0.56±0.03 and 0.127±0.04 μm growth inhibition (GI50) and 260‐fold selectivity for the MCF‐7 breast cancer cell line. A 2,6‐dichlorophenyl moiety saw a 10‐fold decrease in potency; additional nitrogen moieties (‐NO2) enhanced activity (Z)‐2‐(2,6‐dichloro‐3‐nitrophenyl)‐3‐(2‐nitrophenyl)acrylonitrile (26) and (Z)‐2‐(2,6‐dichloro‐3‐nitrophenyl)‐3‐(3‐nitrophenyl)acrylonitrile (27), with the corresponding ‐NH2 analogues (Z)‐2‐(3‐amino‐2,6‐dichlorophenyl)‐3‐(2‐aminophenyl)acrylonitrile (29) and (Z)‐2‐(3‐amino‐2,6‐dichlorophenyl)‐3‐(3‐aminophenyl)acrylonitrile (30) being more potent. Despite this, both 29 (2.8±0.03 μm) and 30 (2.8±0.03 μm) were found to be 10‐fold less cytotoxic than 6. A bromine moiety effected a 3‐fold enhancement in solubility with (Z)‐3‐(5‐bromo‐1H‐pyrrol‐2‐yl)‐2‐(3,4‐dichlorophenyl)acrylonitrile 18 relative to 5 at 211 μg mL−1. Modeling‐guided synthesis saw the introduction of 4‐aminophenyl substituents (Z)‐3‐(4‐aminophenyl)‐2‐(3,4‐dichlorophenyl)acrylonitrile (35) and (Z)‐N‐(4‐(2‐cyano‐2‐(3,4‐dichlorophenyl)vinyl)phenyl)acetamide (38), with respective GI50 values of 0.030±0.014 and 0.034±0.01 μm. Other analogues such as 35 and 36 were found to have sub‐micromolar potency against our panel of cancer cell lines (HT29, colon; U87 and SJ‐G2, glioblastoma; A2780, ovarian; H460, lung; A431, skin; Du145, prostate; BE2‐C, neuroblastoma; MIA, pancreas; and SMA, murine glioblastoma), except compound 38 against the U87 cell line. A more extensive evaluation of 38 ((Z)‐N‐(4‐(2‐cyano‐2‐(3,4‐dichlorophenyl)vinyl)phenyl)acetamide) in a panel of drug‐resistant breast carcinoma cell lines showed 10–206 nm potency against MDAMB468, T47D, ZR‐75‐1, SKBR3, and BT474. Molecular Operating Environment docking scores showed a good correlation between predicted binding efficiencies and observed MCF‐7 cytotoxicity. This supports the use of this model in the development of breast‐cancer‐specific drugs.
Cancer Stem Cell Migration in Three‐Dimensional Aligned Collagen Matrices
Authors: Ray Arja , Morford Rachel K. , Provenzano Paolo P. 
Published: May 2018

AbstractCell migration is strongly influenced by the organization of the surrounding 3‐D extracellular matrix. In particular, within fibrous solid tumors, carcinoma cell invasion may be directed by patterns of aligned collagen in the extra‐epithelial space. Thus, studying the interactions of heterogeneous populations of cancer cells that include the stem/progenitor‐like cancer stem cell subpopulation and aligned collagen networks is critical to our understanding of carcinoma dissemination. Here, we describe a robust method to generate aligned collagen matrices in vitro that mimic in vivo fiber organization. Subsequently, a protocol is presented for seeding aligned matrices with distinct carcinoma cell subpopulations and performing live cell imaging and quantitative analysis of cell migration. Together, the engineered constructs and the imaging techniques laid out here provide a platform to study cancer stem cell migration in 3‐D anisotropic collagen with real‐time visualization of cellular interactions with the fibrous matrix. © 2018 by John Wiley & Sons, Inc.
W(OTf)6‐Catalyzed Synthesis of γ‐Lactones by Ring Contraction of Macrolides or Ring Closing of Terminal Hydroxyfatty Acids in Ionic Liquid
Authors: Xie Zhong‐Yu , Deng Jin , Fu Yao 
Published: May 2018

Abstractγ‐Lactones are an important class of fine chemical products and are widely used in perfumes, medicines, pesticides, dyes, and other fields. Herein, a new method for γ‐lactones preparation based on ring contraction was developed. Starting from macrolides, W(OTf)6 was used to catalyze the ring‐opening polymerization then depolymerization. The depolymerization step was not a common ring‐closing process, and the carbon number of the ring was reduced one by one by rearrangement to form the most thermodynamically stable five‐membered ring compounds. γ‐Caprolactone (180 °C for 10 h) was obtained in a yield of 94 % when [EMIM]OTf was used as the solvent, and the yield of isolated product was up to 85 %. The interaction of various components and the reaction mechanism were studied by FTIR spectroscopy and 1H NMR spectroscopy, respectively. Furthermore, γ‐lactones could be produced when the substrate was extended to terminal hydroxyfatty acids. Unexpectedly, the catalyst was poisoned by 1 equivalent of H2O added during the process and thus the yield decreased greatly. The reaction is green and simple, and proceeds in one pot with high atom economy (100 % for macrolides and with water as the only byproduct for terminal hydroxyfatty acid), which provides a promising approach to synthesizing γ‐lactones.
Patterns of RSA and observed distress during the still‐face paradigm predict later attachment, compliance and behavior problems: A person‐centered approach
Authors: Qu Jin , Leerkes Esther M. 
Published: May 2018

AbstractThis study examined profiles of infant observed distress and physiological regulation indexed by respiratory sinus arrhythmia (RSA) levels during the still‐face paradigm at 6 months using a person‐centered approach. Mothers and infants (N = 206) participated in the study when infants were 6 months, 1 year, and 2 years old. Attachment was assessed at 1 year via the Strange Situation. Children's compliance behaviors were assessed at 2 years during a toy clean‐up task. Mothers reported children's behavior problems at 4.5 years. Latent profile analysis yielded four profiles: highly distressed, but regulating; over‐regulated; resilient to distress; and under‐regulated. Infants in the “resilient to distress” profile characterized by high RSA levels and low negative affect exhibited the most adaptive outcomes such as lower attachment avoidance, higher compliance, and lower behavior problems. Therefore, this study highlights the importance of considering patterns of behavioral and physiological indicators of infant emotionality together for understanding adaptive functioning.
Spring migration patterns, habitat use, and stopover site protection status for two declining waterfowl species wintering in China as revealed by satellite tracking
Authors: Si Yali , Xu Yanjie , Xu Fei , Li Xueyan , Zhang Wenyuan , Wielstra Ben , Wei Jie , Liu Guanhua , Luo Hao , Takekawa John , Balachandran Sivananintha , Zhang Tao , de Boer Willem F. , Prins Herbert H. T. , Gong Peng 
Published: May 2018

AbstractEast Asian migratory waterfowl have greatly declined since the 1950s, especially the populations that winter in China. Conservation is severely hampered by the lack of primary information about migration patterns and stopover sites. This study utilizes satellite tracking techniques and advanced spatial analyses to investigate spring migration of the greater white‐fronted goose (Anser albifrons) and tundra bean goose (Anser serrirostris) wintering along the Yangtze River Floodplain. Based on 24 tracks obtained from 21 individuals during the spring of 2015 and 2016, we found that the Northeast China Plain is far‐out the most intensively used stopover site during migration, with geese staying for over 1 month. This region has also been intensely developed for agriculture, suggesting a causal link to the decline in East Asian waterfowl wintering in China. The protection of waterbodies used as roosting area, especially those surrounded by intensive foraging land, is critical for waterfowl survival. Over 90% of the core area used during spring migration is not protected. We suggest that future ground surveys should target these areas to confirm their relevance for migratory waterfowl at the population level, and core roosting area at critical spring‐staging sites should be integrated in the network of protected areas along the flyway. Moreover, the potential bird–human conflict in core stopover area needs to be further studied. Our study illustrates how satellite tracking combined with spatial analyses can provide crucial insights necessary to improve the conservation of declining Migratory species.
Genetic diversity of melon aphids Aphis gossypii associated with landscape features
Authors: Dong Zhaoke , Li Yifan , Zhang Zhiyong 
Published: May 2018

AbstractDespite increasing evidence that landscape features strongly influence the abundance and dispersal of insect populations, landscape composition has seldom been explicitly linked to genetic structure. We conducted a genetic study of the melon aphid, Aphis gossypii, in two counties of Beijing, China during spring migration using samples from watermelon. We performed aphid genetic analysis using restriction site associated DNA sequencing (2b‐RAD) and investigated the relationship between land cover and the genetic diversity. The percentage area of land cover (cropland, vegetable, orchard, grassland, woodland) was quantified in each particular scale (ranging from 0.5 km to 3 km) and was used as a predictor variable in our generalized linear models. We found a moderate level of genetic differentiation among nine sampled populations. Geographic distance and genetic distance were not significantly associated, indicating that geographic location was not a barrier to migration. These nine populations could be clustered depending on their level of genetic diversity (high and low). The genetic diversity (Shannon’s information index) was positively correlated with grassland at the spatial scales of 1 and 2 km and negatively with orchard and vegetable at 0.5 and 1 km. Genetic diversity was best predicted by the grassland + orchard + vegetable model at a spatial scale of 1 km. Based on the method of relative weights, orchard land had the greatest relative importance, followed by grassland and vegetable land, in that order. This study contributes to our understanding of the genetic variation of aphids in agricultural landscapes.
The role of a non‐native tree in riparian vegetation expansion and channel narrowing along a dryland river
Authors: Scott Michael L. , Reynolds Lindsay V. , Shafroth Patrick B. , Spence John R. 
Published: May 2018

AbstractAlong rivers, native and invasive species may establish and persist on active channel bedforms as part of channel narrowing. Using historical aerial photography and dendrochronology, we quantified spatial and temporal patterns of narrowing and vegetation expansion, including native Fremont cottonwood (Populus fremontii) and non‐native Russian olive (Elaeagnus angustifolia), along the largely unregulated Escalante River in south‐western United States. Russian olive establishment was examined with respect to hydrologic and climate variables. Narrowing along the Escalante River was initiated during a mid‐20th century drought. Cottonwood rapidly colonized higher, bar surfaces between the 1950s and 1981. Small numbers of Russian olive established in moist sites during this period as the channel narrowed by nearly 80%. After 1981, there was no obvious cottonwood establishment but low channel bars and banks were rapidly colonized by Russian olive. Hydroclimate predictors were equivocal but exponential growth of this large‐seeded, shade‐tolerant species lagged its introduction by 30 years, apparently because of delayed reproductive maturity, limited seed availability, and widespread availability of favourable establishment sites following initial channel narrowing. Sediment trapping, levee formation, and modification of channel form by dense, channel‐edge bands of Russian olive progressively limited new establishment sites and by 2000, recruitment declined sharply. Our results have implications for management of non‐native tree invasions along arid‐region rivers, including identification of low, moist, active channel bars where the establishment and physical impacts of Russian olive appear to be most pronounced and where focused management efforts are likely to be most effective.
Intraspecific variation in indirect plant–soil feedbacks influences a wetland plant invasion
Authors: Allen Warwick J. , Meyerson Laura A. , Flick Andrew J. , Cronin James T. 
Published: May 2018

AbstractPlant–soil feedbacks (PSFs) influence plant competition via direct interactions with pathogens and mutualists or indirectly via apparent competition/mutualisms (i.e., spillover to co‐occurring plants) and soil legacy effects. It is currently unknown how intraspecific variation inPSFs interacts with the environment (e.g., nutrient availability) to influence competition between native and invasive plants. We conducted a fully crossed multi‐factor greenhouse experiment to determine the effects ofPhragmites australisrhizosphere soil biota, interspecific competition, and nutrient availability on biomass of replicate populations from one native and two invasive lineages of common reed (P. australis) and a single lineage of native smooth cordgrass (Spartina alterniflora). Harmful soil biota consistently dominatedPSFs involving all threeP. australislineages, reducing biomass by 10%. IndirectPSFs (i.e., soil biota spillover) from the two invasiveP. australislineages reducedS. alterniflorabiomass by 7%, whereasPSFs from the nativeP. australislineage increasedS. alterniflorabiomass by 6%. Interestingly, interspecific competition andPSFs interacted to weaken their respective impacts onS. alterniflora, whereas they exerted synergistic negative effects onP. australis.Phragmites australissoil biota decreasedS. alterniflorabiomass when grown alone (i.e., a soil legacy), but increasedS. alterniflorabiomass when grown withP. australis, suggesting thatP. australisrecruits harmful generalist soil biota or facilitatesS. alternifloravia spillover (i.e., apparent mutualism). Soil biota also reduced interspecific competition impacts onS. alterniflora, although it remained competitively inferior toP. australisacross all treatments. Competitive interactions and responses to nutrients did not differ amongP. australislineages, indicating that interspecific competition and nutrient deposition may not be key drivers ofP. australisinvasion in North America. Although soil biota, interspecific competition, and nutrient availability appear to have no direct impact on the success of invasiveP. australislineages in North America, intraspecific lineage variation in indirect spillover and soil legacies fromP. australisoccur and may have important implications for co‐occurring native species and restoration of invaded habitats. Our study integrates multiple factors linked to plant invasions, highlighting that indirect interactions are likely commonplace in influencing plant community dynamics and invasion success and impacts.
Ultrasound Guided Transversus Thoracic Plane block, Parasternal block and fascial planes hydrodissection for internal mammary post thoracotomy pain syndrome
Authors: Piraccini E. , Biondi G. , Byrne H. , Calli M. , Bellantonio D. , Musetti G. , Maitan S. 
Published: May 2018

AbstractIntroductionPectoral Nerves Block (PECS) and Serratus Plane Block (SPB) have been used to treat persistent post‐surgical pain after breast and thoracic surgery; however, they cannot block the internal mammary region, so a residual pain may occur in that region. Parasternal block (PSB) and Thoracic Transversus Plane Block (TTP) anaesthetize the anterior branches of T2‐6 intercostal nerves thus they can provide analgesia to the internal mammary region.MethodsWe describe a 60‐year‐old man suffering from right post‐thoracotomy pain syndrome with residual pain located in the internal mammary region after a successful treatment with PECS and SPB. We performed a PSB and TTP and hydrodissection of fascial planes with triamcinolone and Ropivacaine.ResultsPain disappeared and the result was maintained 3 months later.DiscussionThis report suggests that PSB and TTP with local anaesthetic and corticosteroid with hydrodissection of fascial planes might be useful to treat a post thoracotomy pain syndrome located in the internal mammary region.SignificanceThe use of Transversus Thoracic Plane and Parasternal Blocks and fascial planes hydrodissection as a novel therapeutic approach to treat a residual post thoracotomy pain syndrome even when already treated with Pectoral Nerves Block and Serratus Plane Block.
Hollow mesoporous structured molecularly imprinted polymer as adsorbent in pipette‐tip solid‐phase extraction for the determination of antiretrovirals from plasma of HIV‐infected patients
Authors: Simões Nathália Soares , de Oliveira Hanna Leijoto , da Silva Ricky Cássio Santos , Teixeira Leila Suleimara , Sales Thaís Lorenna Souza , de Castro Whocely Victor , de Paiva Maria José Nunes , Sanches Cristina , Borges Keyller Bastos 
Published: May 2018

AbstractIn this work a hollow mesoporous structured molecularly imprinted polymer was synthetized and used as adsorbent in pipette‐tip solid‐phase extraction for the determination of lamivudine (3TC), zidovudine (AZT) and efavirenz (EFZ) from plasma of human immunodeficiency virus (HIV) infected patients by high‐performance liquid chromatography (HPLC). All parameters that influence the recovery of the pipette tip based on hollow mesoporous molecularly imprinted polymer solid‐phase extraction (PT–HM–MIP–SPE) method were systematically studied and discussed in detail. The adsorbent material was prepared using methacrylic acid and 4‐vinylpyridine as functional monomers, ethylene glycol dimethacrylate as crosslinker, acetonitrile as solvent, 4,4′‐azobis(4‐cyanovaleric acid) as radical initiator, benzalkonium chloride as surfactant, 3TC, and AZT as templates. The simultaneous separation of 3TC, AZT and EFZ by HPLC‐UV was performed using a Gemini C18 Phenomenex® column (250 mm × 4.6 mm, 5 μm) and mobile phase consisting of acetonitrile: water pH 3.2 (68:32, v/v), flow rate of 1.0 mL/min and λ = 260 nm. The method was linear over the concentration range from 0.25 to 10 μg/mL for 3TC and EFZ, and 0.05 to 2.0 μg mL−1 for AZT, with correlation coefficients larger than 0.99 for all analytes. Recovery ± relative standard deviations (RSDs %) were 41.99 ± 2.38%, 82.29 ± 1.63%, and 83.72 ± 7.52% for 3TC, AZT, and EFZ, respectively. The RSDs and relative errors (REs) were lower than 15% for intra and interday assays. The method has been successfully applied for monitoring HIV‐infected patients outside the therapeutic dosage.
Macroeconomic forecasting with mixed data sampling frequencies: Evidence from a small open economy
Authors: Tsui Albert K. , Xu Cheng Yang , Zhang Zhaoyong 
Published: May 2018

AbstractThe aim of this study was to forecast the Singapore gross domestic product (GDP) growth rate by employing the mixed‐data sampling (MIDAS) approach using mixed and high‐frequency financial market data from Singapore, and to examine whether the high‐frequency financial variables could better predict the macroeconomic variables. We adopt different time‐aggregating methods to handle the high‐frequency data in order to match the sampling rate of lower‐frequency data in our regression models. Our results showed that MIDAS regression using high‐frequency stock return data produced a better forecast of GDP growth rate than the other models, and the best forecasting performance was achieved by using weekly stock returns. The forecasting result was further improved by performing intra‐period forecasting.
Evaluating the impact of physicians' provision on primary healthcare: Evidence from Brazil's More Doctors Program
Authors: Fontes Luiz Felipe Campos , Conceição Otavio Canozzi , Jacinto Paulo de Andrade 
Published: May 2018

AbstractThis study aims to evaluate the More Doctors Program (Programa Mais Médicos) in terms of the provision of physicians, presenting estimates of its impact on hospitalization for ambulatory care sensitive conditions. The differences‐in‐differences method was used with propensity score matching (double difference matching), using 3 specifications, a falsification test, and also a dynamic endogeneity test to confirm the robustness of the results. For the application of this methodology, a panel of municipal data was constructed covering several variables related to socioeconomic, demographic, and public health infrastructure characteristics in the cities for the period from 2010 to 2016. The results show a significant reduction in hospital admissions in treated municipalities with an increasing and perceptible effect in the second year of the program.