bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmentally controlled curvature of single collagen proteins
Authors: Rezaei Naghmeh , Lyons Aaron , Forde Nancy R. 
Published: March 2018

AbstractThe predominant structural protein in vertebrates is collagen, which plays a key role in extracellular matrix and connective tissue mechanics. Despite its prevalence and physical importance in biology, the mechanical properties of molecular collagen are far from established. The flexibility of its triple helix is unresolved, with descriptions from different experimental techniques ranging from flexible to semirigid. Furthermore, it is unknown how collagen type (homo-vs. heterotrimeric) and source (tissue-derived vs. recombinant) influence flexibility. Using SmarTrace, a chain tracing algorithm we devised, we performed statistical analysis of collagen conformations collected with atomic force microscopy (AFM) to determine the protein’s mechanical properties. Our results show that types I, II and III collagens – the key fibrillar varieties – exhibit molecular flexibilities that are very similar. However, collagen conformations are strongly modulated by salt, transitioning from compact to extended as KCl concentration increases, in both neutral and acidic pH. While analysis with a standard worm-like chain model suggests that the persistence length of collagen can attain almost any value within the literature range, closer inspection reveals that this modulation of collagen’s conformational behaviour is not due to changes in flexibility, but rather arises from the induction of curvature (either intrinsic or induced by interactions with the mica surface). By modifying standard polymer theory to include innate curvature, we show that collagen behaves as an equilibrated curved worm-like chain (cWLC) in two dimensions. Analysis within the cWLC model shows that collagen’s curvature depends strongly on pH and salt, while its persistence length does not. Thus, we find that triple-helical collagen is well described as semiflexible, irrespective of source, type, pH and salt environment. These results demonstrate that collagen is more flexible than its conventional description as a rigid rod, which may have implications for its cellular processing and secretion.
Effect of 5-transisomer of arachidonic acid on model liposomal membranes studied by a combined simulation and experimental approach
Authors: Tremi Ioanna , Anagnostopoulos Dimitrios , Spyratou Ellas , Gkeka Paraskevi , Georgakilas Alexandros G. , Chatgilialoglu Chryssostomos , Cournia Zoe 
Published: March 2018

AbstractUnsaturated fatty acids are found in humans predominantly in thecisconfiguration. Fatty acids in thetransconfiguration are primarily the result of human processing (transfats), but can also be formed endogenously by radical stress. Thecis-transisomerization of fatty acids by free radicals could be connected to several pathologies.Transfats have been linked to an increased risk of coronary artery disease; however, the reasons for the resulting pathogenesis remain unclear. Here, we investigate the effect of a monotransisomer of arachidonic acid (C20:4-5trans,8cis,11cis,14cis) produced by free radicals in physiological concentration on a model erythrocyte membrane using a combined experimental and theoretical approach. Molecular Dynamics (MD) simulations of two model lipid bilayers containing arachidonic acid and its 5-transisomer in 3% mol. were carried out for this purpose. The 5-transisomer formation in the phospholipids was catalyzed by HOCH2CH2S• radicals, generated from the corresponding thiol by γ-irradiation, in multilamellar vesicles (MLVs) of SAPC. Large unilamellar vesicles were made by the extrusion method (LUVET) as a biomimetic model forcis-transisomerization. Atomic Force Microscopy and Dynamic Light Scattering were used to measure the average size, morphology, and the z-potential of the liposomes. Both results from MD simulations and experiments are in agreement and indicate that the two model membranes display different physicochemical properties in that the bilayers containing thetransfatty acids were more ordered and more rigid than those containing solely thecisarachidonic acid. Correspondingly, the average size of the liposomes containingtransisomers was smaller than the ones without.
Assessing macrophyte seasonal dynamics using dense time series of medium resolution satellite data
Authors: Villa Paolo , Pinardi Monica , Bolpagni Rossano , Gillier Jean-Marc , Zinke Peggy , Nedelcuţ Florin , Bresciani Mariano 
Published: March 2018

AbstractThanks to the improved spatial and temporal resolution of new generation Earth Observation missions, such as Landsat 8 and Sentinel-2, the potential of remote sensing techniques in mapping land surface phenology of terrestrial biomes can now be tested in inland water systems.We assessed the capabilities of dense time series of medium resolution satellite data to deliver quantitative information about macrophyte phenology metrics, focusing on three temperate European shallow lakes with connected wetlands, located in Italy, France and Romania.Leaf area index (LAI) maps for floating and emergent macrophyte growth forms were derived from semi-empirical regression modelling based on the best performing spectral index, with an error level around 0.11 m2m-2. Phenology metrics were computed from LAI time series using TIMESAT code and used to analyse macrophyte seasonal dynamics in terms of spatial patterns and species-dependent variability. Peculiar patterns of autochthonous and allochthonous species seasonality across the three study areas were related to the environmental characteristics of each area in terms of ecological and hydrological conditions.In addition, the influence of satellite dataset characteristics – i.e. cloud cover thresholding, temporal resolution and missing acquisitions – on phenology timing metrics retrieval was assessed. Results have shown that with full resolution (5-day revisit) time series, cloud cover can bias phenology timing metrics by less than 2 days, and that reducing temporal resolution to 15 days (similar to Landsat revisit) still allows for mapping the start and peak of macrophyte growth with an error level around 2–3 days.
The territory of my body: Testosterone prevents limb cooling in the Rubber Hand Illusion
Authors: van der Westhuizen Donné , Page Teneille , Solms Mark , Honk Jack van 
Published: March 2018

ABSTRACTThe Rubber Hand Illusion (RHI) is an experimental paradigm for assessing changes in body ownership. Recent findings in the field suggest that social-emotional variables can influence such changes. Since body ownership is a mechanism that enables subjects to organise information about the environment and interact efficiently in it, changes in body ownership should have important implications for social power. In the current study, we investigated whether 0.5mg of testosterone, a steroid hormone strongly implicated in the achievement of power and dominance, affected the RHI. Forty-nine females participated in a double-blind, placebo-controlled experiment in which the RHI was induced. Compared to placebo, testosterone had no effects on the usual alteration of subjective ownership over the rubber limb or on subjective sense of proprioceptive drift. However, unlike the placebo group, testosterone-treated participants did not display an objective decline in the temperature of their own (hidden) hand following induction of the illusion. These findings suggest that testosterone strengthens implicit but not explicit bodily self-representations. We propose that effective maintenance of implicit body boundaries can be regarded, conceptually, as a primary defensive state facilitating integrity of the self.
KCC2 overexpression prevents the paradoxical seizure-promoting action of somatic inhibition
Authors: Magloire Vincent , Cornford Jonathan , Lieb Andreas , Kullmann Dimitri M. , Pavlov Ivan 
Published: March 2018

AbstractAlthough cortical interneurons are apparently well-placed to suppress seizures, several recent reports have highlighted a paradoxical role of parvalbumin-positive perisomatic-targeting (PV+) interneurons in ictogenesis. Here, we use an acute in vivo model of focal cortical seizures in awake behaving mice, together with closed-loop optogenetic manipulation of PV+ interneurons, to investigate their function during seizures. We show that photo-depolarization of PV+ interneurons rapidly switches from an anti-ictal to a pro-ictal effect within a few seconds of seizure initiation. The pro-ictal effect of delayed photostimulation of PV+ interneurons was not shared with dendrite-targeting somatostatin-positive (SOM+) interneurons. We also show that this switch can be prevented by overexpression of the neuronal potassium-chloride co-transporter KCC2 in principal cortical neurons. These results suggest that strategies aimed at improving the ability of principal neurons to maintain intracellular chloride levels in the face of excessive network activity can prevent interneurons from contributing to seizure perpetuation.
Analog closed-loop optogenetic modulation of hippocampal pyramidal cells dissociates gamma frequency and amplitude
Authors: Nicholson Elizabeth , Kuzmin Dmitry A , Leite Marco , Akam Thomas E , Kullmann Dimitri M 
Published: March 2018

AbstractGamma-band oscillations are implicated in modulation of attention and integration of sensory information. The finding that cross-regional coherence varies with task and performance suggests a role for gamma oscillations in flexible communication among anatomically connected brain areas. How networks become entrained is incompletely understood. Specifically, it is unclear how the spectral and temporal characteristics of network oscillations can be altered on rapid timescales needed for efficient communication. We use closed-loop optogenetic modulation of principal cell excitability to interrogate the dynamical properties of hippocampal oscillations. Gamma frequency and amplitude can be modulated bi-directionally, and dissociated, by phase-advancing or delaying optogenetic feedback to pyramidal cells. Closed-loop modulation alters the synchrony rather than average frequency of action potentials, in principle avoiding disruption of population rate-coding of information. Modulation of phasic excitatory currents in principal neurons is sufficient to manipulate oscillations, suggesting that feed-forward excitation of pyramidal cells has an important role in determining oscillatory dynamics and the ability of networks to couple with one another.
A Network of Noncoding Regulatory RNAs Acts in the Mammalian Brain
Authors: Kleaveland Benjamin , Shi Charlie Y. , Stefano Joanna , Bartel David P. 
Published: March 2018

SUMMARYNoncoding RNAs (ncRNAs) play increasingly appreciated gene-regulatory roles. Here, we describe a regulatory network centered on four ncRNAs—a long ncRNA, a circular RNA, and two microRNAs—using gene editing in mice to probe the molecular consequences of disrupting key components of this network. The long ncRNA Cyrano uses an extensively paired site to miR-7 to trigger destruction of this microRNA. Cyrano-directed miR-7 degradation is much more efficient than previously described examples of target-directed microRNA degradation, which come from studies of artificial and viral RNAs. By reducing miR-7 levels, Cyrano prevents repression of miR-7–targeted mRNAs and enables the accumulation of Cdr1as, a circular RNA known to regulate neuronal activity. Without Cyrano, excess miR-7 causes cytoplasmic destruction of Cdr1as, in part through enhanced slicing of Cdr1as by a second miRNA, miR-671. Thus, several types of ncRNAs can collaborate to establish a sophisticated regulatory network.HIGHLIGHTSA long noncoding RNA, a circular RNA, and two microRNAs form a regulatory networkThe Cyrano long noncoding RNA directs potent, multiple-turnover destruction of miR-7Unchecked miR-7 prevents accumulation of Cdr1as circular RNA in cytoplasm of neurons miR-7 prevents this accumulation by enhancing the miR-671-directed slicing of Cdr1as
Effects of Hydrogen‐Donating or Metal‐Chelating Antioxidants on the Oxidative Stability of Organogels Made of Beeswax and Grapeseed Oil Exposed to Light Irradiation
Authors: Hong Seungmi , Kim Mi‐Ja , Park Sungkwon , Lee Suyong , Lee Jonggil , Lee JaeHwan 
Published: March 2018

AbstractTo enhance the oxidative stability of organogels made from grapeseed oil, the antioxidant effects of sesamol, α‐tocopherol, β‐carotene, ethylenediaminetetraacetic acid (EDTA), and citric acid were determined in beeswax‐based organogels stored under light or in the dark conditions at 25 °C. Without the addition of antioxidants, the organogels rapidly oxidized under light irradiation but not during storage in the dark. Sesamol showed the highest antioxidant activity at concentrations of 10 to 40 ppm, whereas the other compounds exhibited no antioxidant activity at 10 ppm. α‐Tocopherol and β‐carotene improved the oxidative stability of organogels at concentrations above 40 and 100 ppm, respectively. The addition of sesamol yielded better oxidative stability than the addition of EDTA or a mixture of sesamol and citric acid. Sesamol can improve the oxidative stability of organogels, which could lead to economic benefits for the food industry.Practical ApplicationRecently, interest in organogels has increased due to their properties of maintaining a solid state at room temperature and composition of trans‐free and highly unsaturated fatty acids. However, the addition of antioxidants is necessary due to the high degree of unsaturation in organogels. The results of this study showed that the addition of sesamol significantly enhanced the oxidative stability of organogels under light irradiation. Therefore, the use of sesamol‐supplemented organogels could prolong the shelf‐life of bakery or meat food products.
Efficacy of hypofractionated radiotherapy in patients with non‐melanoma skin cancer: Results of a systematic review
Authors: Gunaratne Dakshika A , Veness Michael J 
Published: March 2018

SummaryRadiation oncologists are increasingly tasked with the management of elderly patients with non‐melanoma skin cancer, unsuitable for surgical intervention due to inoperable lesions and/or poor performance status. In this cohort, hypofractionated radiotherapy, delivered either daily, alternative daily or once weekly is highly effective. A systematic literature search was conducted of PUBMED, MEDLINE and EMBASE databases using the algorithm (‘radiotherapy’ OR ‘radiation therapy’ OR ‘brachytherapy’) AND (‘hypofraction’ OR ‘hypofractionated’ OR ‘hypofractionation’) AND (‘skin neoplasms’ OR ‘carcinoma’ OR ‘malignancy’) AND (‘skin’ OR ‘epidermis’ OR ‘epidermal’ OR ‘cutaneous’). Forty relevant publications (1983–2017) encompassing 12,337 irradiated lesions were retrieved. Studies documented a mean age of 71.73 years and male predilection (54.5%). Both external beam radiotherapy and brachytherapy were utilized. Tumour subtype was squamous cell carcinoma (23.5%), basal cell carcinoma (75.2%) or others (1.3%). Irradiated lesions were primary (or denovo) (92.6%), located on the head and neck (95.7%) and received definitive therapy (96.5%). Analysis demonstrated a mean weighted total radiotherapy dose (38.15 Gy), dose per fraction (7.95 Gy) and treatments per week (2.98). Despite significant heterogeneity in the study population, the radiotherapy delivered and follow‐up, local recurrence rate (crude or Kaplan–Meier analysis) did not exceed 7.9% in all but three of the 36 publications providing these data. Twenty‐nine publications documented local control exceeding 90%. There is a body of evidence documenting the efficacy of hypofractionated radiotherapy as an option that confers no obvious disadvantage in local control when compared to traditional more protracted radiotherapy schedules.
MiR‐577 suppresses epithelial‐mesenchymal transition and metastasis of breast cancer by targeting Rab25
Authors: Yin Chonggao , Mou Qingjie , Pan Xinting , Zhang Guoxin , Li Hongli , Sun Yunbo 
Published: March 2018

BackgroundMicroRNAs can act as both tumor suppressor genes and oncogenes and participate in cell proliferation, metastasis, and apoptosis. Low levels of miR‐577 are found in several cancers, for example, thyroid carcinoma, glioblastoma, and hepatocellular carcinoma. The aim of this study was to investigate the effect of miR‐577 on breast cancer (BC).MethodsThe relative level of miR‐577 in 120 BC tissues and cells was detected by real‐time PCR. MDA‐MB‐231 cells with upregulated miR‐577 and MCF‐7 cells with downregulated miR‐577 were established. Transwell invasion assays were used to examine the invasiveness of cells. Epithelial‐mesenchymal transition (EMT) markers were evaluated by immunofluorescence and Western blot. Targeted combinations of miR‐577 and Rab25 were analyzed by luciferase assays. Xenograft models were used to examine the effect of miR‐577 on BC metastasis.ResultsMiR‐577 expression was significantly suppressed in BC tissues. Tumor size, tumor stage, and lymphatic metastasis were attributed to miR‐577 expression. Moreover, miR‐577 overexpression strongly inhibited the invasiveness and EMT of BC cells in vitro. MiR‐577 directly regulated Rab25 in BC. Rab25 upregulation by miR‐577 decreased the levels of E‐cadherin and increased the levels of Vimentin. Notably, Rab25 knockdown inhibited BC invasion; however, an increase in Rab25 counteracted the invasive effect of miR‐577 in BC.ConclusionResults indicated that miR‐577 suppressed EMT by inhibiting Rab25 expression in BC. MiR‐577 and Rab25 are considered potential targets of BC treatment.
Creation and Implementation of an Outpatient Pathway for Atrial Fibrillation in the Emergency Department Setting: Results of an Expert Panel
Authors: Baugh Christopher W. , Clark Carol L. , Wilson Jason W. , Stiell Ian G. , Kocheril Abraham G. , Luck Krista K. , Myers Troy D. , Pollack Charles V. , Roumpf Steven K. , Tomassoni Gery F. , Williams James M. , Patel Brian B. , Wu Fred , Pines Jesse M. 
Published: March 2018

AbstractAtrial fibrillation and flutter (AF) is a common condition among emergency department (ED) patients in the United States. Traditionally, ED care for primary complaints related to AF focus on rate control, and patients are often admitted to an inpatient setting for further care. Inpatient care may include further telemetry monitoring and diagnostic testing, rhythm control, a search for identification of AF etiology, and stroke prophylaxis. However, many patients are eligible for safe and effective outpatient management pathways. They are widely used in Canada and other countries but less widely adopted in the United States. In this project, we convened an expert panel to create a practical framework for the process of creating, implementing, and maintaining an outpatient AF pathway for emergency physicians to assess and treat AF patients, safely reduce hospitalization rates, ensure appropriate stroke prophylaxis, and effectively transition patients to longitudinal outpatient treatment settings from the ED and/or observation unit. To support local pathway creation, the panel also reached agreement on a protocol development plan, a sample pathway, consensus recommendations for pathway components, sample pathway metrics, and a structured literature review framework using a modified Delphi technique by a technical expert panel of emergency medicine, cardiology, and other stakeholder groups.
Association Between Excessive Alcohol Consumption and Echocardiographic Parameters According to the Presence of Flushing Reaction in Korean Men: A Community‐Based Study
Authors: Ko Hyeonyoung , Song Yun‐Mi , Lee Sang‐Chol , Park Seung Woo , Sung Joohon , Lee Kayoung , Lee Eunae 
Published: March 2018

BackgroundThe objective of this study was to investigate the effect of excessive alcohol consumption on heart reflected by various echocardiographic parameters according to the presence or absence of flushing reaction that might reflect acetaldehyde metabolism.MethodsA total of 854 Korean men without significant cardiovascular diseases who underwent echocardiography and participated in the Korean Healthy Twin Study were used as subjects of this study. These subjects were classified into 3 categories: nondrinker, moderate drinker (≤196 g/wk), and heavy drinker (>196 g/wk) within 2 strata of flushing reaction to alcohol drinking. Association between echocardiographic measurements and categories of the amount of alcohol consumption considering flushing reaction were evaluated using mixed linear regression model.ResultsThe proportion of flushers among drinkers was 39.5% (278 of 703). In stratified analysis by flushing reaction, nonflushers showed significantly higher left ventricular mass index (β: 4.605; 95% CI: 0.966, 8.243) and significantly lower ratio of peak early diastolic velocities (E peak) over peak late diastolic velocities of mitral inflow (β: −0.103; 95% CI: −0.198, −0.008) in heavy drinkers compared to nondrinkers. Flushers showed significantly higher left atrial (LA) volume index (β: 2.712; 95% CI: 0.456, 4.968) in heavy drinkers and significantly lower ratio of E peak over the peak early diastolic mitral annular velocities (β: −0.493; 95% CI: −0.902, −0.085) in moderate drinkers compared to nondrinkers. However, the interaction according to flushing reaction was only statistically significant for the association between alcohol consumption and LA volume index (p for interaction = 0.004).ConclusionsAlcohol consumption is associated with changes in cardiac structure and function. Such association might be influenced by acetaldehyde metabolism.
Microstructure of the eye tunics, eyelids and ocular glands of the Sulawesi bear cuscus (Ailurops ursinusTemminck, 1824) (Phalangeridae: Marsupialia) based on anatomical, histological and histochemical studies
Authors: Klećkowska‐Nawrot Joanna E. , Goździewska‐Harłajczuk Karolina , Darska Marta , Barszcz Karolina , Janeczek Maciej 
Published: March 2018

AbstractThis study described the anatomy, histology and the histochemical analysis of the eye tunics, the upper and lower eyelid, the third eyelid, the lacrimal gland and the superficial gland of the third eyelid in adult Sulawesi bear cuscus. The eyeball and the eyelids with the orbital glands were harvested immediately post‐mortem. The eyeball in the Sulawesi bear cuscus had a sphere‐like shape. The pupil was round, and the lens was a circular biconvex body. There was neither tapetum lucidum nor Harderian gland. Similarly, there were no eyelashes in the lower eyelid. The lymphoid follicles and the high endothelial venules (HEV) were found in the lymphoid region only in the third eyelid and in the connective tissue of the superficial gland of the third eyelid. The third eyelid in the bear cuscus resembled the letter “T.” The lacrimal gland and superficial gland of the third eyelid were multilobar tubuloacinar glands. The histological analysis and histochemical studies showed that the lacrimal gland in the Sulawesi bear cuscus produced a mucoserous secretion with predominantly serous cells. In contrast, the superficial gland of the third eyelid produced a serous secretion with a single acinus mucous in character.