bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic force microscopy study of red blood cell membrane nanostructure during oxidation‐reduction processes
Authors: Kozlova E. , Chernysh A. , Sergunova V. , Gudkova O. , Manchenko E. , Kozlov A. 
Published: May 2018

AbstractThe morphology and functional state of red blood cells (RBCs) mainly depends on the configuration of the spectrin network, which can be broken under the influence of intoxication because of oxidation processes in the cells. Measurement of these processes is a complex problem. The most suitable and prospective method that resolves this problem is atomic force microscopy (AFM). We used AFM to study the changes in the spectrin matrix and RBC morphology during oxidation processes caused by ultraviolet (UV) irradiation in RBC suspension. The number of discocytes decreased from 98% (in control) to 12%. We obtained AFM images of the spectrin matrix in RBC ghosts. Atomic force microscopy allows for the direct observation and quantitative measurement of the disturbances in the structure of the spectrin matrix during oxidation processes in RBCs. The typical section size of the spectrin network changed from approximately 80 to 200 nm (in control) to 600 nm and even to 1000 nm after UV irradiation. An AFM study showed that incubation of RBCs with Cytoflavin® after UV irradiation preserved the forms of RBCs almost at control levels; 89% of the cells remained as discocytes. To quantify the intensity of the oxidation‐reduction processes, the percentage of haemoglobin derivatives was measured. The content of methaemoglobin varied in the range of 1% to 70% during the experiments. These evidence‐based studies are important for the fundamental research of interactions during redox processes in RBCs at the molecular level.
Discovery of potent polyphosphate kinase 1 (PPK1) inhibitors using structure‐based exploration of PPK1Pharmacophoric space coupled with docking analyses
Authors: Bashatwah Rasha M. , Khanfar Mohammad A. , Bardaweel Sanaa K. 
Published: May 2018

AbstractInorganic polyphosphate (polyP) is present in all living forms of life. Studied mainly in prokaryotes, polyP and its associated enzymes are vital in diverse metabolic activities, in some structural functions, and most importantly in stress responses. Bacterial species, including many pathogens, encode a homolog of a major polyP synthesis enzyme, Poly Phosphate Kinase (PPK) with 2 different genes coding for PPK1 and PPK2. Genetic deletion of the ppk1 gene leads to reduced polyP levels and the consequent loss of virulence and stress adaptation responses. This far, no PPK1 homolog has been identified in higher‐order eukaryotes, and, therefore, PPK1 represents a novel target for chemotherapy. The aim of the current study is to investigate PPK1 from Escherichia coli with comprehensive understanding of the enzyme's structure and binding sites, which were used to design pharmacophores and screen a library of compounds for potential discovery of selective PPK1 inhibitors. Verification of the resultant inhibitors activities was conducted using a combination of mutagenic and chemical biological approaches. The metabolic phenotypic maps of the wild type E. coli (WT) and ppk1 knockout mutant were generated and compared with the metabolic map of the chemically inhibited WT. In addition, biofilm formation ability was measured in WT, ppk1 knockout mutant, and the chemically inhibited WT. The results demonstrated that chemical inhibition of PPK1, with the designed inhibitors, was equivalent to gene deletion in altering specific metabolic pathways, changing the metabolic fingerprint, and suppressing the ability of E. coli to form a biofilm.
Corporate social responsibility and employee engagement: The moderating role of CSR‐specific relative autonomy and individualism
Authors: Rupp Deborah E. , Shao Ruodan , Skarlicki Daniel P. , Paddock Elizabeth Layne , Kim Tae‐Yeol , Nadisic Thierry 
Published: May 2018

SummaryGrowing evidence suggests that employees' perceptions of their employer's corporate social responsibility (CSR) relate positively to employee work engagement. This is an important connection given the impact of work engagement on both employee health and organizational productivity, as well as the importance of CSR for society. In this paper, however, we argue that the CSR perceptions–work engagement relationship cannot be assumed to be universal and that both individual and contextual factors will place meaningful boundary conditions on this effect. Integrating motivation and cross‐cultural theories, we propose that the relationship between employees' CSR perceptions and their work engagement will be stronger among employees who perceive higher CSR‐specific relative autonomy (i.e., employees' contextualized motivation for complying with, advocating for, and/or participating in CSR activities) and that this amplification effect will be stronger among employees who are higher on individualism (studied at the individual‐level of analysis). These predictions were mostly supported among a sample of 673 working adults from five different regions (Canada, China [mainland], France, Hong Kong, and Singapore) and while controlling for first‐party justice perceptions, moral identity, employee demographics, and employer/nation characteristics. Theoretical and practical implications are discussed.
The effect of toothbrushing and flossing sequence on interdental plaque reduction and fluoride retention: A randomized controlled clinical trial
Authors: Mazhari Fatemeh , Boskabady Marzie , Moeintaghavi Amir , Habibi Atieh 
Published: May 2018

AbstractBackgroundMechanical plaque control methods such as brushing and flossing are highly recommended to remove dental plaque. The aim of this study is to evaluate the efficacy of the sequence of brushing and flossing on reducing interdental plaque and increasing fluoride retention in that area.MethodsThis randomized controlled crossover trial was conducted on 25 dental students. After prophylaxis, they were asked to discontinue all forms of oral hygiene for 48 hours. The study was performed in two phases with two‐week washout intervals. In one phase, they first brushed, then flossed (sequence 1: brush‐floss group). In the other phase they initially used dental floss then brushed (sequence 2: floss‐brush group). At each phase, dental plaque (using the Rustogi Modified Navy Plaque Index) and fluoride concentrations (using a fluoride ion specific electrode) were measured before and after flossing and brushing, and the dental plaque reduction and fluoride increase were compared between the two groups using the mixed model test. A significance level of 5% was selected.ResultsIn the floss‐brush group interdental and whole plaque was reduced significantly more than the brush‐floss group (p = 0.001, p = 0.009 respectively). However, marginal plaque did not show any statistically significant difference between the two groups (p = 0.2). Fluoride concentrations in interdental plaque were significantly higher in the floss‐brush group than the other group (p = 0.027).ConclusionThe results showed that flossing followed by brushing is preferred to brushing then flossing in order to reduce interdental plaque and increase fluoride concentration in interdental plaque.
Capillary electrophoresis, a method for the determination of nucleic acid ligands covalently attached to quantum dots representing a donor of Förster resonance energy transfer
Authors: Datinská Vladimíra , Klepárník Karel , Belšánová Barbora , Minárik Marek , Foret František 
Published: May 2018

AbstractThe synthesis and determination of the structure of a Förster resonance energy transfer probe intended for the detection of specific nucleic acid sequences are described here. The probe is based on the hybridization of oligonucleotide modified quantum dots with a fluorescently labeled nucleic acid sample resulting in changes of the fluorescence emission due to the energy transfer effect. The stoichiometry distribution of oligonucleotides conjugated to quantum dots was determined by capillary electrophoresis separation. The results indicate that one to four molecules of oligonucleotide are conjugated to the surface of a single nanoparticle. This conclusion is confirmed by the course of the dependence of Förster resonance energy transfer efficiency on the concentration of fluorescently labeled complementary single‐stranded nucleic acid, showing saturation. While the energy transfer efficiency of the probe hybridized with complementary nucleic acid strands was 30%, negligible efficiency was observed with a noncomplementary strand.
Alpha‐Linolenic Acid, but Not Palmitic Acid, Negatively Impacts Survival, Asexual Reproductive Rate, and Clonal Offspring Size in Hydra oligactis
Authors: Kaliszewicz Anita , Jarząbek Karolina , Szymańska Justyna , Karaban Kamil , Sierakowski Maciej 
Published: May 2018

AbstractHydra, as sit‐and‐wait predators with limited food selectivity, could serve as model organisms for the analysis of the effect of a particular dietary component on growth and reproduction. We investigated the effect of food quality and of diets enriched with palmitic (PAM) or α‐linolenic acid (ALA) on the life history traits of two hydra species: Hydra oligactis and Hydra vulgaris. We tested the hypothesis that a diet enriched with polyunsaturated fatty acids (PUFA) can stimulate growth and reproduction in simple metazoans with a sit‐and‐wait type of predatory strategy. Our results revealed that a diet based on Artemia nauplii, which are not a natural food for freshwater hydra, stimulated growth, asexual reproduction, and survival in hydra. Artemia nauplii were characterized by the highest lipid content of all used food sources. The analysis of the fatty acid content of hydra indicated the domination the n‐6 fatty acids over n‐3 (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], and ALA). Arachidonic acid appeared to be the dominant PUFA in Hydra, irrespective of diet supplementation with palmitic acid or ALA. The dietary supplementation of ALA negatively affected the survival, asexual reproductive rate, and size of clonal offspring of H. oligactis and had no effect on the life history traits of H. vulgaris. Our results also suggest that the hydras are not able to efficiently convert ALA into other essential fatty acids, such as EPA and DHA. To our knowledge, this is the first report about the adverse effects of n‐3 fatty acid supplementation in primitive metazoans such as hydra.
Development of Electrospun Composite Fibers in Multiscale Structure and Investigating the Performance on Proliferation and Osteogenic Differentiation of ADSCs
Authors: Xuan Liuyang , Shi Ming , Ma Shuangshuang , Ye Feng , Shi Xuetao , Yan Ling , Li Yan 
Published: May 2018

AbstractElectrospun composite membranes in multiscale structures are developed for bone tissue engineering. Aligned polycaprolactone (PCL) fibers entrapping CA‐HAp microparticles (containing CaCO3, hydroxyapatite, and casein in a hierarchical organization) are electrospun to find whether synergistic effects of fiber alignment and CA‐HAp microparticles on improving osteogenic differentiation can be obtained. CA‐HAp microparticles are in a spherical morphology of 1.42 ± 0.26 µm. Their presence increases fiber diameter and does not significantly affect fiber alignment. On all membranes, adipose derived stem cells (ADSCs) from humans spread very well. On a random group, cells distribute randomly and the presence of CA‐HAp microparticles facilitates cell proliferation, especially for the one at CA‐HAp/PCL 50 wt%; the one at CA‐HAp/PCL 20 wt% shows significantly much higher alkaline phosphatase (ALP) activity (112.0% higher) than the pure PCL membrane. On aligned samples, cells align along fibers and expression of ALP is enhanced. However, at the same composition (CA‐HAp/PCL 20 wt%), the random sample has much higher ALP activity than the aligned sample. The expressions of osteogenic marker genes are also evaluated. Combining the results and the applicability of membranes together, the random membrane at CA‐HAp/PCL 20 wt% is the best candidate for bone tissue engineering.
Neurologic impairments from pediatric low‐grade glioma by tumor location and timing of diagnosis
Authors: Sadighi Zsila S. , Curtis Elizabeth , Zabrowksi Jennifer , Billups Catherine , Gajjar Amar , Khan Raja , Qaddoumi Ibrahim 
Published: May 2018

AbstractBackgroundThe neurologic outcomes of low‐grade gliomas (LGGs) according to tumor location and duration of presenting symptoms remain poorly characterized in children.ProcedureWe retrospectively reviewed neurologic impairments in 246 pediatric patients with LGGs (88 with optic pathway and midline tumors, 56 with posterior fossa tumors, 52 with cerebral hemisphere tumors, 35 with brainstem tumors, and 15 with spinal cord tumors) who were treated at St. Jude Children's Research Hospital between 1995 and 2005. We compared neurologic impairments (defined by Common Terminology Criteria for Adverse Events, version 4.03) by tumor location and prediagnosis symptom interval (PSI) (≥ 3 months or < 3 months) at first and last patient visits.ResultsThe median age of diagnosis was 7.1 years; median PSI was 2.1 months; and median time to last follow‐up was 11.6 years. LGGs in the cerebral hemispheres resulted in significantly fewer neurologic impairments, compared with that of other locations at baseline (P < 0.001) and at last follow‐up (P < 0.001). In all patients, PSIs greater than 3 months resulted in a significantly higher incidence of ataxia and dysmetria at last follow‐up (42%, P = 0.003). Greater PSI was also significantly associated with worsening lower extremity motor weakness from cerebral hemisphere tumors; dysmetria from optic pathway and midline tumors; eye and visual dysfunction from posterior fossa tumors; and ear and vestibular disturbances from brainstem tumors (P ≤ 0.05).ConclusionNeurologic impairment in pediatric LGGs varies by tumor location, and PSIs greater than 3 months affect some functionally important neurologic outcomes.
Perinatal outcomes of single fetal survivor after fetal intervention for complicated monochorionic twins
Authors: Hoffman Mallory , Habli Mounira , Donepudi Roopali , Boring Noemi , Johnson Anthony , Moise Kenneth J. , Papanna Ramesha 
Published: May 2018

AbstractObjectiveTo compare perinatal outcomes between acute single fetal demise following fetoscopic laser photocoagulation to planned selective reduction (SR) in complicated monochorionic twin pregnancies.MethodsThis was a secondary analysis of prospectively collected data in complicated monochorionic twin pregnancies from 2 fetal centers from 2011 to 2016. Group 1 included women undergoing fetoscopic laser photocoagulation for twin‐twin transfusion syndrome (TTTS) who experienced a single fetal demise within 24 hours of the procedure. Group 2 consisted of women undergoing planned selective reduction (SR) with TTTS, and Group 3 SR for indications other than TTTS.ResultsSurvival of the remaining co‐twin at birth was highest in Group 1 (n = 77 patients; 95%) compared with that in Group 2 (n = 15; 80%) and Group 3 (n = 32; 78%; P = .047). The preterm premature rupture of membrane rate was higher in Group 1 (47%) compared with that in Group 2 (33%) and Group 3 (7%; P < .001). Group 1 had a lower gestational age at delivery and shorter procedure‐to‐delivery interval compared with the other 2 groups (P < .01).ConclusionWhen single fetal demise occurs following fetoscopic laser photocoagulation, the surviving co‐twin is more likely to survive to delivery but has higher PPROM rates and a shorter latency period compared with planned selective reduction for TTTS or other indications.
Factors associated to early intrauterine fetal demise after laser for TTTS by preoperative fetal heart and Doppler ultrasound
Authors: Delabaere Amélie , Leduc France , Reboul Quentin , Fuchs Florent , Wavrant Sandrine , Dubé Johanne , Fouron Jean‐Claude , Audibert François 
Published: May 2018

AbstractObjectiveTo determine the prognostic value of fetal Doppler and echocardiographic parameters for intrauterine fetal demise (IUFD) within 24 hours and within 1 week after laser coagulation in monochorionic pregnancies complicated by twin‐twin transfusion syndrome.MethodThis retrospective study correlated the preoperative hemodynamic and echocardiography parameters to the outcome in fetuses with twin‐twin transfusion syndrome undergoing laser therapy.ResultsOne hundred and twelve laser coagulations were performed between February 2006 and June 2015. The total (single and double) IUFD rate was 27.7%. Further, 59% of IUFD occurred within 24 hours and 74.4% occurred within 1 week after laser. The following were associated to IUFD within 24 hours: the middle cerebral arterial pulsatility index in the donor, abnormal umbilical artery (UA) end diastolic flow, increased middle cerebral artery peak systolic velocity, and right ventricular myocardial performance index (RV‐MPI) z‐score in the recipient. For IUFD within 1 week were the pulsatility index in the donor UA and the recipient abnormalities in UA, ductus venosus, middle cerebral artery‐peak systolic velocity, and RV‐MPI z‐score.ConclusionFollowing laser was early IUFD that was associated with Doppler findings suggesting donor cerebroplacental redistribution, and recipient overload cardiomyopathy, such as abnormal ductus venosus and UA Dopplers as well as an increase of RV‐MPI.
GOLD assessment of COPD severity in the Clinical Practice Research Datalink (CPRD)
Authors: Rebordosa Cristina , Plana Estel , Aguado Jaume , Thomas Steven , García-Gil Esther , Perez‐Gutthann Susana , Castellsague Jordi 
Published: May 2018

AbstractPurposeTo evaluate availability of spirometry and symptom data in the Clinical Practice Research Datalink (United Kingdom) to assess COPD severity using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2016 definition and comparing it with an algorithm used in other studies.MethodsThis was a descriptive, noninterventional, secondary database cohort study of patients with COPD aged 40 years or older, who initiated treatment with specific COPD medications. Patients were classified according to COPD severity (1) in GOLD 2016 “ABCD” categories based on symptoms (Medical Research Council dyspnea grade, COPD Assessment Test, breathlessness), percent predicted FEV1, and exacerbation history and (2) as mild, moderate, severe, or very severe based on treatment and exacerbation history.ResultsThe study included 63 900 patients with COPD aged 40 years or older that were new users of 1 or more COPD medication of interest. Percent predicted FEV1 was available for 80.9% of patients; symptoms for 75.6% of patients. Classification into GOLD 2016 ABCD categories was possible for 75.6% of the patients. The GOLD 2016 ABCD definition classified more patients under the high‐risk categories (22.1%, A; 18.8%, B; 21.3%, C; 37.9%, D) than did the adapted algorithm (7.9%, mild; 48.6%, moderate; 42.1%, severe; 1.4%, very severe).ConclusionUsing our adaptation of the GOLD 2016 COPD severity classification, the information in the Clinical Practice Research Datalink allowed us to ascertain COPD severity in approximately 75% of patients with COPD. Algorithms that include medication use tend to misclassify patients with the extreme COPD severity categories.
Selective Enrichment of Polydopamine in Mesoporous Nanocarriers for Nuclear‐Targeted Drug Delivery
Authors: Guan Haidi , Wang Liucan , Zhang Jixi , Xing Yuxin , Cai Kaiyong 
Published: May 2018

AbstractSmall particle size and strong host–guest interactions are prerequisites in the field of nuclear‐targeting nanocarriers for overcoming the multidrug resistance of cancer cells. A novel scheme of synthesizing hybrid organic–inorganic nanocarriers with mesopores is introduced to enhance the delivery efficiency of therapeutic drugs. Specifically, inorganic silica and organic polydopamine (PDA) are integrated inside the pore framework by the assistance of organic silanes terminated by amino/thiol groups. Silica‐etching by hydrothermal treatment leads to the selective enrichment of bioadhesive PDA and size reductions for the hybrids (to ≈30 nm). Interestingly, a high drug loading capacity (523 µg mg−1 for doxorubicin hydrochloride), as well as pH/ glutathione dual‐responsive drug release properties, are realized by the nanocarriers, owing to their high surface area (825 m2 g−1) and the π‐stacking and/or hydrophobic–hydrophobic interactions stemming from PDA. More importantly, the conjugation of TAT peptide facilitates the intranuclear localization of the nanocarriers and the release of the encapsulated drugs directly within the nucleoplasm of the multidrug resistant MCF‐7/ADR cancer cells. Therefore, these results provide a controllable method of engineering high‐surface‐area nanocarriers with bioadhesive polymers on the pore surface for advanced drug delivery applications.
Robust Fabrication of Quantum Dots on Few‐Layer MoS2 by Soft Hydrogen Plasma and Post‐Annealing
Authors: Cai Di , Xiao Shaoqing , Nan Haiyan , Gu Xiaofeng , Ostrikov Kostya (Ken) 
Published: May 2018

AbstractApart from unique properties of layered transition‐metal dichalcogenide nanosheets like MoS2, quantum dots (QDs) from these layered materials promise novel science and applications due to their quantum confinement effect. However, the reported fabrication techniques for such QDs all involve the use of liquid organic solvents and the final material extraction from such liquid dispersions. Here a novel and convenient dry method for the synthesis of MoS2 quantum dots interspersed on few‐layer MoS2 using soft hydrogen plasma treatment followed by post‐annealing is demonstrated. The size of MoS2 nanodots can be well controlled by adjusting the working pressure of hydrogen plasma and post‐thermal annealing. This method relies on the cumulative hydrogen ion bombardment effect which can destroy the hexagonal structure of the top MoS2 layer and disintegrate the top layer into MoS2 nanodots and even QDs. Post‐thermal annealing can further reduce the size. Such MoS2 quantum dots interspersed on few‐layer MoS2 exhibit two new photoluminescence peaks at around 575 nm because of the quantum confinement effect. This dry method is versatile, scalable, and compatible with the semiconductor manufacturing processes, and can be extended to other layered materials for applications in hydrogen evolution reaction, catalysis, and energy devices.
Prediction of the in vitro developmental competence of early‐cleavage‐stage human embryos with time‐lapse imaging and oxygen consumption rate measurement
Authors: Goto Kaori , Kumasako Yoko , Koike Megumi , Kanda Akiko , Kido Kyoko , Nagaki Miyuki , Otsu Eiko , Kawabe Fumiko , Kai Yufuko , Utsunomiya Takafumi 
Published: May 2018

AbstractPurposeTo assess an embryo's ability to develop into a good‐quality blastocyst during the early‐cleavage stage using time‐lapse imaging and the oxygen consumption rate.MethodsIn total, 942 zygotes had their oxygen consumption rates measured. In total, 282 zygotes were assessed by using time‐lapse imaging. In total, 121 zygotes were examined by using both their oxygen consumption rate and time‐lapse imaging.ResultsThe embryos with moderate respiration rates of between 0.41 and 0.61 (×1014/mol s−1) on day 3 had a 22.1% chance of becoming good‐quality blastocysts; those outside that range had a 14.3% chance. With the time‐lapse system, when the first division was within 24 hours, 22.3% of the embryos grew to good blastocysts. After 24 hours, the rate dropped to 8.6%. The intervals between two consecutive cleavages were calculated and the duration of the second cell cycle was defined. When the time was between nine hours and 13 hours, there was a higher rate of good blastocysts. Regarding both criteria, when the embryos had progressed in the optimal range, a high percentage of them had become good blastocysts; it was 8.0% outside of that range.ConclusionIndividual embryos with the potential to develop into good‐quality blastocysts could be selected at day 3 of culture using these systems.