bluuebunny/crossref_metadata_2025 huggingface dataset:
Cluster Analysis, Variables
Authors: D'Agostino Ralph B. , Russell Heidy K. , Lee Taiyeong
Published: February 2017

Cluster analysis involves grouping objects, subjects or variables, with similar characteristics into groups. Similarity or dissimilarity of objects is measured by a particular index of association. The focus here is on clustering of variables instead of subjects. Types of methods that cluster variables based on correlation structure of variables or factorial structure of variables are considered, where factorial structure refers to a structure obtained from principal component analysis or factor analysis. The approaches described for cluster analysis use various indices of association such as factor loadings, correlation matrix, and cosine matrix. Examples of these are shown and the advantages and disadvantages of each approach are discussed.
Population‐based analysis of pathological correlates of dementia in the oldest old
Authors: Tanskanen Maarit , Mäkelä Mira , Notkola Irma‐Leena , Myllykangas Liisa , Rastas Sari , Oinas Minna , Lindsberg Perttu J. , Polvikoski Tuomo , Tienari Pentti J. , Paetau Anders
Published: February 2017

Objective

The aim of this study was to analyze brain pathologies which cause dementia in the oldest old population.

Methods

All 601 persons aged ≥85 years living in the city of Vantaa (Finland), on April 1st, 1991 formed the study population of the Vantaa85 +  study, 300 of whom were autopsied during follow‐up (79.5% females, mean age‐at‐death 92 ± 3.7 years). Alzheimer's disease (AD) pathology (tau and beta‐amyloid [Aβ]), cerebral amyloid angiopathy (CAA) and Lewy‐related pathologies were analyzed. Brain infarcts were categorized by size (<2 mm, 2–15 mm, >15 mm) and by location. Brain hemorrhages were classified as microscopic (<2 mm) and macroscopic.

Results

195/300 (65%) were demented. 194/195 (99%) of the demented had at least one neuropathology. Three independent contributors to dementia were identified: AD‐type tau‐pathology (Braak stage V‐VI), neocortical Lewy‐related pathology, and cortical anterior 2–15 mm infarcts. These were found in 34%, 21%, and 21% of the demented, respectively, with the multivariate odds ratios (OR) for dementia 5.5, 4.5, and 3.4. Factor analysis investigating the relationships between different pathologies identified three separate factors: (1) AD‐spectrum, which included neurofibrillary tau, Aβ plaque, and neocortical Lewy‐related pathologies and CAA (2) >2 mm cortical and subcortical infarcts, and (3) <2 mm cortical microinfarcts and microhemorrhages. Multipathology was common and increased the risk of dementia significantly.

Interpretation

These results indicate that AD‐type neurodegenerative processes play the most prominent role in twilight cognitive decline. The high prevalence of both neurodegenerative and vascular pathologies indicates that multiple preventive and therapeutic approaches are needed to protect the brains of the oldest old.
Hematite‐Based Photoelectrode Materials for Photoelectrocatalytic Inhibition of Alzheimer's β‐Amyloid Self‐Assembly
Authors: Kim Kayoung , Lee Byung Il , Chung You Jung , Choi Woo Seok , Park Chan Beum
Published: February 2017

A visible light‐active, hematite‐based photoelectrode platform for suppressing β‐amyloid (Aβ) self‐assembly in vitro is reported. Upon illumination of a light‐emitting diode with an anodic bias, the hematite photoanode generates reactive radical species, such as superoxide ions and hydroxyl radicals, via photoelectrocatalytic process. According to our analyses, the hematite photoanode exhibited a strong inhibitory effect on Aβ aggregation under visible light illumination and anodic bias. We found that hole‐derived radicals played a significant role of oxidizing Aβ peptides, which effectively blocked further aggregation. The efficacy of photoelectrocatalytic inhibition on Aβ aggregation was enhanced by introducing cobalt phosphate (Co‐Pi) as a co‐catalyst on the hematite photoanode, which facilitated the separation of electron‐hole pairs. We verified that both bare and Co‐Pi@hematite photoanodes are biocompatible and effective in reducing Aβ aggregation‐induced cytotoxicity.
Functionalized Polymeric Membrane with Enhanced Mechanical and Biological Properties to Control the Degradation of Magnesium Alloy
Authors: Wong Hoi Man , Zhao Ying , Leung Frankie K. L. , Xi Tingfei , Zhang Zhixiong , Zheng Yufeng , Wu Shuilin , Luk Keith D. K. , Cheung Kenneth M. C. , Chu Paul K. , Yeung Kelvin W. K.
Published: February 2017

To achieve enhanced biological response and controlled degradation of magnesium alloy, a modified biodegradable polymer coating called polycaprolactone (PCL) is fabricated by a thermal approach in which the heat treatment neither alters the chemical composition of the PCL membrane nor the rate of magnesium ion release, pH value, or weight loss, compared with the untreated sample. The changes in the crystallinity, hydrophilicity, and oxygen content of heat‐treated PCL coating not only improve the mechanical adhesion strength between the coating and magnesium substrate but also enhance the biological properties. Moreover, the thermally modified sample can lead to higher spreading and elongation of osteoblasts, due to the enhanced hydrophilicity and CO to CO functional group ratio. In the analyses of microcomputed tomography from one to four weeks postoperation, the total volume of new bone formation on the heat‐treated sample is 10%–35% and 70%–90% higher than that of the untreated and uncoated controls, respectively. Surprisingly, the indentation modulus of the newly formed bone adjacent to the heat‐treated sample is ≈20% higher than that of both controls. These promising results reveal the clinical potential of the modified PCL coating on magnesium alloy in orthopedic applications.
Observation of Metal Nanoparticles for Acoustic Manipulation
Authors: Chen Mian , Cai Feiyan , Wang Chen , Wang Zhiyong , Meng Long , Li Fei , Zhang Pengfei , Liu Xin , Zheng Hairong
Published: February 2017

Use of acoustic trapping for the manipulation of objects is invaluable to many applications from cellular subdivision to biological assays. Despite remarkable progress in a wide size range, the precise acoustic manipulation of 0D nanoparticles where all the structural dimensions are much smaller than the acoustic wavelength is still present challenges. This study reports on the observation of metal nanoparticles with different nanostructures for acoustic manipulation. Results for the first time exhibit that the hollow nanostructures play more important factor than size in the nanoscale acoustic manipulation. The acoustic levitation and swarm aggregations of the metal nanoparticles can be easily realized at low energy and clinically acceptable acoustic frequency by hollowing their nanostructures. In addition, the behaviors of swarm aggregations can be flexibly regulated by the applied voltage and frequency. This study anticipates that the strategy based on the unique properties of the metal hollow nanostructures and the manipulation method will be highly desirable for many applications.
Prognostic significance of cytogenetic abnormalities in T‐cell prolymphocytic leukemia
Authors: Hu Zhihong , Medeiros L. Jeffrey , Fang Lianghua , Sun Yi , Tang Zhenya , Tang Guilin , Sun Tsieh , Quesada Andres E. , Hu Shimin , Wang Sa A. , Pei Lin , Lu Xinyan
Published: February 2017

T‐cell prolymphocytic leukemia (T‐PLL) is an aggressive mature T‐cell neoplasm. The most common cytogenetic abnormality associated with T‐PLL is inv(14)(q11.2q32) involving TCL1, but other abnormalities also have been reported. In this study, we correlated cytogenetic abnormalities with clinical outcome in 97 T‐PLL patients, including 66 men and 31 women with a median age of 63 years (range, 34‐81). Twenty‐seven patients had a normal karyotype (NK), one had two chromosomal aberrations, and 69 had a complex karyotype (CK). Patients with a CK had poorer overall survival (OS) than patients with a NK (P = .0016). In the CK group, the most common aberrations involved 14q (n = 45) and 8q (n = 38). Additional deletions of chromosomes 17p, 11q, 6q, 12p, 13q were observed frequently. No individual cytogenetic abnormality impacted OS. Patients with ≥5 aberrations had an OS of 11 months versus 22 months in patients with <5 aberrations (P = 0.0132). Fluorescence in situ hybridization for TCL1 successfully performed in 27 cases showed rearrangement in 8/10 (80%) NK versus 16/17 (94%) CK cases. OS of patients with TCL1 rearrangement and/or 14q aberrations was not significantly different from patients without TCL1 rearrangement and 14q aberrations (P = .3467). Patients with refractory disease showed worse OS in both the NK and CK groups (P = .0014 and P < .0001, respectively), compared with patients who achieved remission but then relapsed. Stem cell transplantation did not appear to improve OS regardless of karyotype complexity. In conclusion, patients with T‐PLL often have a CK which is a poor prognostic factor, particularly in patients with ≥5 cytogenetic aberrations.
(E)‐Alkene Synthesis via Nano‐Copper/Homogeneous Palladium Co‐Catalysis and Selectivity Amplification
Authors: Liu Shiwen , Zeng Xiaojun , Xu Bo
Published: February 2017

A practical regio‐ and stereoselective synthesis of multisubstituted (E)‐alkenes via a nano‐copper/Pd(PPh3)4 co‐catalyzed tandem hydroborylation/Suzuki coupling sequence has been developed. This catalytic system circumvented the common problem of isolation and purification of organoboron intermediates and gave only (E)‐alkenes in good to excellent yields and excellent functional group tolerance. The key for the very high regioselectivity is the selectivity amplification of two tandem steps.
(Ge4Bi14)4−: Ein Fall von “Element‐Entmischung” auf molekularer Skala
Authors: Wilson Robert J. , Dehnen Stefanie
Published: February 2017

Die Extraktion eines Feststoffs der nominalen Zusammensetzung “K2GeBi” mit 1,2‐Diaminoethan (en) in Gegenwart von 4,7,13,16,21,24‐Hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacosan (crypt‐222) führte zur Bildung des Salzes [K(crypt‐222)]4(Ge4Bi14). Das 18‐atomige Zintl‐Anion (Ge4Bi14)4− darin hat eine bislang unbekannte Topologie, die sich als formales Kondensationsprodukt zweier E113−‐Käfige entlang einer gemeinsamen Ge4‐“Taille” verstehen lässt. (Ge4Bi14)4− stellt somit das größte und strukturell komplexeste Polyanion mit Bismutatomen dar. Wir beschreiben seine schrittweise Bildung, die geometrische und elektronische Struktur und diskutieren relative Stabilitäten der Isomere mit unterschiedlicher Verteilung der vier Germaniumatome auf den 18 Atompositionen, die wir mittels DFT‐Rechnungen untersucht haben.
Zur Gold‐katalysierten Erzeugung von Vinylkationen aus 1,5‐Diinen
Authors: Wurm Thomas , Bucher Janina , Duckworth Sarah B. , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: February 2017

Konjugierte 1,5‐Diin‐Systeme mit zwei aromatischen Resten an den terminalen Positionen der Alkine wurden in Anwesenheit eines Gold‐Katalysators umgesetzt. Unter milden Bedingungen werden arylsubstituierte Dibenzopentalene erzeugt. Berechnungen sagen aurierte Vinylkationen als Schlüsselintermediate der Reaktion voraus. Eine bidirektionale Reaktion lieferte selektiv das angular anellierte Produkt in hoher Ausbeute, was über Berechnungen erklärt werden kann.
Unexpected Ge–Ge Contacts in the Two‐Dimensional Ge4Se3Te Phase and Analysis of Their Chemical Cause with the Density of Energy (DOE) Function
Authors: Küpers Michael , Konze Philipp M. , Maintz Stefan , Steinberg Simon , Mio Antonio M. , Cojocaru‐Mirédin Oana , Zhu Min , Müller Merlin , Luysberg Martina , Mayer Joachim , Wuttig Matthias , Dronskowski Richard
Published: February 2017

A hexagonal phase in the ternary Ge–Se–Te system with an approximate composition of GeSe0.75Te0.25 has been known since the 1960s but its structure has remained unknown. We have succeeded in growing single crystals by chemical transport as a prerequisite to solve and refine the Ge4Se3Te structure. It consists of layers that are held together by van der Waals type weak chalcogenide–chalcogenide interactions but also display unexpected Ge–Ge contacts, as confirmed by electron microscopy analysis. The nature of the electronic structure of Ge4Se3Te was characterized by chemical bonding analysis, in particular by the newly introduced density of energy (DOE) function. The Ge–Ge bonding interactions serve to hold electrons that would otherwise go into antibonding Ge–Te contacts.
On the Gold‐Catalyzed Generation of Vinyl Cations from 1,5‐Diynes
Authors: Wurm Thomas , Bucher Janina , Duckworth Sarah B. , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: February 2017

Conjugated 1,5‐diynes bearing two aromatic units at the alkyne termini were converted in the presence of a gold catalyst. Under mild conditions, aryl‐substituted dibenzopentalenes were generated. Calculations predict that aurated vinyl cations are key intermediates of the reaction. A bidirectional approach provided selective access to the angular annulated product in high yield, which was explained by calculations.
Surface molecularly imprinted polymer microspheres based on nano‐TiO2 for selective recognition of kaempferol
Authors: Huang Zejun , Zhang Zhimiao , Xia Qiang , Li Chunli , Yun Yanbin
Published: February 2017

The molecular imprinting technique is a new method for preparing molecularly imprinted polymers (MIPs) with specific molecular recognition sites for certain target molecules. In this study, a novel, facile preparation method was presented, called “seed precipitation polymerization,” for the synthesis of MIPs via surface imprinting and a support matrix. In the polymerization process, kaempferol was used as the template molecule, methacrylic acid as the functional monomer, nano‐TiO2 as the support, azodiisobutyronitrile as the initiator, and ethylene glycol dimethacrylate as the crosslinker in acetonitrile solvent. The synthesized T‐MIP and MIP were analyzed by infrared spectroscopy and scanning electron microscopy. In addition, the obtained polymers were evaluated by adsorption isotherms and dynamic curves for their selective recognition properties for kaempferol. The results show that T‐MIP shows regular spherical particles; the adsorption dynamic curves of T‐MIP show that the adsorption capacity increases with time and reaches a maximum value and then finally reaches equilibrium, and the T‐MIP exhibits a higher affinity for kaempferol than does the MIP. The adsorption follows pseudo‐second‐order kinetics, the Freundlich adsorption equation fits the experimental data well, and there is strong evidence for multiple‐layer adsorption. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44888.
A reinvestigation of a colorimetric method aimed at quantifying minute amounts of carboxylic acids present in polystyrene and poly(n‐alkyl methacrylate)s
Authors: Kerloc'h Brendan , Brissault Blandine , Penelle Jacques , Atvars Teresa Dib Zambon
Published: February 2017

A reinvestigation of a method (Christoff, M.; Yamaki, S. B.; de Oliveira, M. G.; Atvars, T. D. Z. J. Appl. Polym. Sci. 2004, 92, 830–838) aimed at quantitatively determining trace amounts of residual carboxylic acid functional groups in polymethacrylates and polystyrene has been carried out. The original technique was based on the monitoring of an absorption band in the UV–visible region (610 nm) that appears after known amounts of polymer are added to a benzene solution containing the basic form of the Nile Blue A dye. It is shown here that the assumption upon which the methodology is based, that is, the occurrence of a 1:1 stoichiometric and complete proton transfer of the carboxylic acid to the dye, is invalid and yields greatly underestimated values for the COOH contents, possibly by 2–3 orders of magnitude. In addition, temperature strongly influences the equilibrium constant for the acid‐base reaction. Lastly, preparation and storage of the analytical solution was found to be problematic, supporting earlier claims that hydrolysis of Nile Blue A base does occur when preparing the benzene solution and/or over storage, yielding Nile Red dye whose absorption in the visible part of the spectrum significantly overlaps. Based on the above results, further use of this technique, at least in its quantitative version, should be discouraged. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44931.
Morphologic Patterns Formed by the Anomalous Fibers Occurring Along the Anterior Capsule of the Crystalline Lens in People With the Long Anterior Zonule Trait
Authors: Roberts Daniel K. , Yang Yongyi , Morettin Christina E. , Newman Tricia L. , Roberts Mary F. , Wilensky Jacob T.
Published: February 2017

People with the long anterior zonule (LAZ) trait, which may have prevalence near 2%, have zonular fibers that extend more central than usual along the anterior capsule of the crystalline lens. The anomalous fibers can be observed in vivo with clinical slit lamp biomicroscopy after pharmacologic pupil dilation, and although minimally studied, the LAZ trait may have importance to glaucoma, retinal degeneration, and cataract surgery. To further characterize LAZ morphology, a custom computer program was used to trace LAZ fibers seen on retro‐illumination photos acquired during previous study at an academic, urban eye care facility in Chicago, IL. There were 59 African‐Americans (54 female; median age = 70 years, 53–91 years) included in the analysis. After initial review of the zonule tracings, we identified three basic LAZ patterns. We called one pattern (47% of right eyes) a “non‐segmental LAZ pattern,” which was predominated by fibers that could be visually traced to the dilated pupil border where they became obscured by the iris. Another pattern (35% of right eyes), the “segmental LAZ pattern,” was predominated by fibers that appeared to terminate abruptly without detectable extension to the pupil border. The third pattern (18% of right eyes), the “mixed LAZ pattern,” had a more equivalent mixture of the other two fiber morphologies. Compared to the “non‐segmental” group, the “segmental” LAZ eyes had smaller central zonule‐free zones (P < 0.0001), and they tended to exhibit fewer LAZ fibers (P = 0.07). These data improve understanding of LAZ clinical anatomy and may be helpful to future investigation. Anat Rec, 300:1336–1347, 2017. © 2017 Wiley Periodicals, Inc.
Lanthanide(III)‐Based Multicolor Luminescent Hybrid Gel for Amine Sensing
Authors: Liu Caixia , Wang Tianren , Yang Daqing , Li Zhiqiang , Li Huanrong
Published: February 2017

Bridged polysilsesquioxanes (BPs) show great potential in the development of lanthanide‐based luminescent materials, owing to their capacity to loading lanthanide complexes with high concentration and their flexible processability. A novel BP precursor, consisting of a C3‐symmetrical benzene central core moiety, capable of sensitizing the luminescence of Eu3+ and Tb3+ is reported. Tunable, full‐color luminescent gels were facilely prepared by mixing the as‐synthesized precursor and Ln3+ ions in appropriate solvents. By either changing the Eu3+/Tb3+ molar ratio or altering the excitation wavelength, the emission colors of the final gels can be finely tuned. Additionally, the yellow‐colored emissive gel with a molar ratio of Eu3+ to Tb3+ of 0.5 can be used as an effective ratiometric luminescent sensor for distinguishing amines with lower pKa (<5) from those with higher pKa (>9).
Mixing Adaptive Fault Tolerant Control of Quadrotor UAV
Authors: Büyükkabasakal Kemal , Fi̇dan Barış , Savran Aydoğan
Published: February 2017

In this paper, a multiple model adaptive fault tolerant control scheme is proposed based on mixing of the control signals generated by a set of linear quadratic state feedback controllers. Each of these controllers are designed considering closed loop system performance for a particular range of fault. Stability analysis of the proposed scheme is provided. The paper further presents specific design and implementation for motion control of quadrotor unmanned aerial vehicles (UAVs). The designed mixing adaptive controller is tested via real‐time experiments on Quanser Qball‐X4 UAVs. The experimental results verify the efficiency of the proposed scheme.
Examination of variables that affect the efficacy of instructive feedback
Authors: Haq Shaji S. , Zemantic Patricia K. , Kodak Tiffany , LeBlanc Brittany , Ruppert Traci E.
Published: February 2017

Instructive feedback is a procedure in which additional, nontarget stimuli are presented during instructional trials for students with a wide array of disabilities. This preliminary investigation examined whether participant behavior during instructive feedback, including attending and echoic behavior, altered the efficacy of instructive feedback for 2 children with autism. Results showed that participant behavior during instructive feedback related to training outcomes for both participants and treatment modifications based on participant behavior influenced acquisition. Future directions of research and implications for practice are discussed.
Association between psychological health and wound complications after surgery
Authors: Britteon P , Cullum N , Sutton M
Published: February 2017

Background

Surgical wound complications remain a major cause of morbidity, leading to higher costs and reduced quality of life. Although psychological health is widely considered to affect wound healing, the evidence on wound outcomes after surgery is mixed. Studies generally focus on small samples of patients undergoing a specific procedure and have limited statistical power.

Methods

This study investigated the relationship between three different measures of anxiety and/or depression and seven adverse surgical outcomes using observational data collected before and after surgery between 2009 and 2011. A wide range of confounding factors was adjusted for, including patient demographics, physical co-morbidities, health-related behaviours, month of operation, procedure complexity and treating hospital.

Results

The estimation sample included 176 827 patients undergoing 59 410 hip replacements, 64 145 knee replacements, 38 328 hernia repairs and 14 944 varicose vein operations. Patients with moderate anxiety or depression had an increased probability of wound complications after a hip replacement (odds ratio (OR) 1·17, 95 per cent c.i. 1·11 to 1·24). They were more likely to be readmitted for a wound complication (OR 1·20, 1·02 to 1·41) and had an increased duration of hospital stay by 0·19 (95 per cent c.i. 0·15 to 0·24) days. Estimated associations were consistent across all four types of operation and for each measure of anxiety and/or depression.

Conclusion

Preoperative psychological health is a significant risk factor for adverse wound outcomes after surgery for four of the procedures most commonly performed in England.
Relationship of the recurrent laryngeal nerve to the inferior thyroid artery: A comparison of findings from two systematic reviews
Authors: Polednak Anthony P.
Published: February 2017

Systematic reviews (SRs) of anatomical studies may include a meta‐analysis (MA) that provides weighted averages as pooled estimates of prevalence. The relationship of the recurrent laryngeal nerve (RLN) to the inferior thyroid artery (ITA) or its branches has been assessed in two published SRs, one without MA of 32 studies (SR1) and the other with MA of 79 studies (SR2). Both SRs reported differences in RLN–ITA patterns (in three categories) by side of the body, but the anterior pattern was less frequent in SR1 vs. SR2. The aim of this review was to explain the differences. The unweighted data from SR1 were found to be more affected (vs. SR2) by a single study with the largest number of RLNs and a low proportion anterior. In a MA using data from SR1, the pooled prevalence estimate for the anterior pattern was substantial (35%) on the right side (vs. 15% on the left) and close to the findings published in SR2. These consistent findings should be relevant to surgeons in attempting to avoid iatrogenic injury to RLNs. Comparison of methods and results from two or more SRs on the same anatomical relationships may be useful in evidence‐based anatomy. Clin. Anat. 30:318–321, 2017. © 2017 Wiley Periodicals, Inc.
Chemical Characteristics, Antimicrobial, and Cytotoxic Activities of the Essential Oil of Egyptian Cinnamomum glanduliferum Bark
Authors: Taha AlShaimaa M. , Eldahshan Omayma A.
Published: February 2017

The essential oil isolated from the bark of Cinnamomum glanduliferum (Wall) Meissn grown in Egypt was screened for its composition as well as its biological activity for the first time. The chemical composition was analyzed by GC and GC/MS. The antimicrobial activity of the oil was assessed using agar‐well diffusion method toward representatives for each of Gram‐positive bacteria, Gram‐negative bacteria, and fungi. The cytotoxic activity was checked using three human cancer cell lines. Twenty seven compounds were identified, representing 99.07% of the total detected components. The major constituents were eucalyptol (65.87%), terpinen‐4‐ol (7.57%), α‐terpineol (7.39%). The essential oil possessed strong antimicrobial activities against Escherichia coli, with an activity index of one and minimum inhibitory concentration (MIC) equaling to 0.49 μg/ml. The essential oil possessed good antimicrobial activities against methicillin‐resistant Staphylococcus aureus, Geotrichum candidum, Pseudomonas aeruginosa, Bacillus subtilis, Helicobacter pylori, Aspergillus fumigatus (MIC: 7.81, 1.95, 7.81, 0.98, 31.25, and 32.5 μg/ml, respectively). A considerable activity was reported against S. aureus and Mycobacterium tuberculosis (MIC; 32.5 and 31.25 μg/ml, respectively). The extracted oil was cytotoxic to colon (HCT‐116), liver (HepG2), and breast (MCF‐7) carcinoma cell lines with IC50 of 9.1, 42.4, and 57.3 μg/ml, respectively. These results revealed that Egyptian Cinnamomum glanduliferum bark oil exerts antimicrobial and cytotoxic activities mainly due to eucalyptol and other major compounds.
Construction of Acid–Base Synergetic Sites on Mg‐bearing BEA Zeolites Triggers the Unexpected Low‐Temperature Alkylation of Phenol
Authors: Xie Jingyan , Zhuang Wenxia , Zhang Wei , Yan Ning , Zhou Yu , Wang Jun
Published: February 2017

Novel Mg‐bearing BEA zeolites are synthesized to simultaneously endow significantly enhanced basicity without compromising acidity over the zeolite framework. Serving as efficient solid acid–base bifunctional catalysts, they achieve the liquid‐phase selective methylation of phenol with methanol to produce o‐ and p‐cresol (o/p=2) under mild conditions. The method is readily extendable to the alkylation of phenols with various alcohols. Stereo‐ and regioselectivity (>95 % for p‐product) was attained on the alkylation of phenol with bulky tert‐butyl alcohol, rendering the first acid–base cooperative shape‐selective catalysis relying on the basicity of zeolites. A preliminary mechanistic analysis reveals that the remarkable activity and shape‐selectivity come from the superior special acidic–basic synergetic catalytic sites on the uniform microporous channels of the BEA zeolite.
Application of chemometric methods for multi‐elemental characterization of fruit juices and nectars analysed in the Portuguese Total Diet Studies pilot study
Authors: Coelho Inês , Rego Andreia , Gueifão Sandra , Nascimento Ana Claudia , Castanheira Isabel
Published: February 2017

Multivariate analysis was applied to test the adequacy of pooling samples versus single units as a sampling strategy to estimate dietary intake and risk assessment of chemical elements in nonalcoholic beverages. The contents of 18 minerals and trace elements (Cr, Mn, Cu, Zn, As, Se, Mo, Sr, Co, Cd, Sn, Pb Fe, Mg, Ca, P, Na, and K) in fruit juices and nectars were determined by inductively coupled plasma–optical emission spectrometry and inductively coupled plasma–mass spectrometry. Arsenic speciation was done with high‐performance liquid chromatographer‐inductively coupled plasma–mass spectrometry. The data obtained in pooled samples and single units were then studied by analysis of variance and least significant difference tests, Spearman's correlation, principal component analysis, and cluster analysis. Analysis of variance and least significant difference tests were used to evaluate analytical data from pooled samples and single units. Values of individual units and pooled samples were statistically different with the exception of Se (P < .05), illustrating pooling as an inadequate strategy. Spearman's correlation displayed significant correlations between the following pairs: P‐K (0.924), Mo‐K (0.888), Mo‐P (0.876), and Ca‐Mg (0.846), indicating that chemical elements could be from the same source, having a natural occurrence, or the same exposure sources. By applying principal component analysis and cluster analysis, it was possible to classify juices and nectars by fruit type and geographical origin. It was observed that 2 principal components accounted for 59% of the total variance in the data. Cluster analysis classified samples into 5 clusters. Combined chemometric tools are suited to select appropriate laboratory sampling strategies for risk assessment. Application of chemometric methods to analytical data may be useful to group samples by similar characteristics for the purpose of Total Diet Studies.
Towards Monodisperse Star‐Shaped Ladder‐Type Conjugated Systems: Design, Synthesis, Stabilized Blue Electroluminescence, and Amplified Spontaneous Emission
Authors: Jiang Yi , Fang Mei , Chang Si‐Ju , Huang Jin‐Jin , Chu Shuang‐Quan , Hu Shan‐Ming , Liu Cheng‐Fang , Lai Wen‐Yong , Huang Wei
Published: February 2017

A novel series of monodisperse star‐shaped ladder‐type oligo(p‐phenylene)s, named as TrL‐n (n=1–3), have been explored. Their thermal and electrochemical properties, fluorescence transients, photoluminescence quantum yields, density functional theory calculations, electroluminescence (EL) and amplified spontaneous emission (ASE) properties have been systematically investigated to unravel the molecular design on optoelectronic properties. The resulting materials showed excellent structural perfection, free of chemical defects, and exhibited great thermal stability (Td: 404–418 °C and Tg: 147–184 °C) and amorphous glassy morphologies. Compared with their corresponding linear counterparts FL‐m (m=1–3), TrL‐n showed only little bathochromic shifts (5–12 nm) for the absorption maxima λmax in both solution and films. The star‐shaped ladder‐type compounds exhibited enhanced optical stability and suppressed low‐energy emission. Their EL spectra exhibited excellent stability with increasing the driving voltage from 6 to 12 V. Moreover, superior low ASE thresholds were recorded for TrL‐n compared with FL‐m. Rather low ASE threshold (29 nJ per pulse or 1.60 μJ cm−2) was recorded for TrL‐3, demonstrating their promising potential as excellent gain media. This study provides a novel design concept to develop monodisperse star‐shaped ladder‐type materials with excellent structural perfection, which are vital for shedding light on exploring robust organic emitters for optoelectronic applications.
Design of Na+‐Selective Fluorescent Probes: A Systematic Study of the Na+‐Complex Stability and the Na+/K+ Selectivity in Acetonitrile and Water
Authors: Schwarze Thomas , Müller Holger , Schmidt Darya , Riemer Janine , Holdt Hans‐Jürgen
Published: February 2017

There is a tremendous demand for highly Na+‐selective fluoroionophores to monitor the top analyte Na+ in life science. Here, we report a systematic route to develop highly Na+/K+ selective fluorescent probes. Thus, we synthesized a set of fluoroionophores 1, 3, 4, 5, 8 and 9 (see Scheme ) to investigate the Na+/K+ selectivity and Na+‐ complex stability in CH3CN and H2O. These Na+‐probes bear different 15‐crown‐5 moieties to bind Na+ stronger than K+. In the set of the diethylaminocoumarin‐substituted fluoroionophores 1–5, the following trend of fluorescence quenching 1>3>2>4>5 in CH3CN was observed. Therefore, the flexibility of the aza‐15‐crown‐5 moieties in 1–4 determines the conjugation of the nitrogen lone pair with the aromatic ring. As a consequence, 1 showed in CH3CN the highest Na+‐induced fluorescence enhancement (FE) by a factor of 46.5 and a weaker K+ induced FE of 3.7. The Na+‐complex stability of 1–4 in CH3CN is enhanced in the following order of 2>4>3>1, assuming that the O‐atom of the methoxy group in the ortho‐position, as shown in 2, strengthened the Na+‐complex formation. Furthermore, we found for the N‐(o‐methoxyphenyl)aza‐15‐crown‐5 substituted fluoroionophores 2, 8 and 9 in H2O, an enhanced Na+‐complex stability in the following order 8>2>9 and an increased Na+/K+ selectivity in the reverse order 9>2>8. Notably, the Na+‐induced FE of 8 (FEF=10.9), 2 (FEF=5.0) and 9 (FEF=2.0) showed a similar trend associated with a decreased K+‐induced FE [8 (FEF=2.7)>2 (FEF=1.5)>9 (FEF=1.1)]. Here, the Na+‐complex stability and Na+/K+ selectivity is also influenced by the fluorophore moiety. Thus, fluorescent probe 8 (Kd=48 mm) allows high‐contrast, sensitive, and selective Na+ measurements over extracellular K+ levels. A higher Na+/K+ selectivity showed fluorescent probe 9, but also a higher Kd value of 223 mm. Therefore, 9 is a suitable tool to measure Na+ concentrations up to 300 mm at a fluorescence emission of 614 nm.
Photoswitching of Dihydroazulene Derivatives in Liquid‐Crystalline Host Systems
Authors: Petersen Anne Ugleholdt , Jevric Martyn , Mandle Richard J. , Sims Mark T. , Moore John N. , Cowling Stephen J. , Goodby John W. , Nielsen Mogens Brøndsted
Published: February 2017

Photoswitches and dyes in the liquid‐crystalline nematic phase have the potential for use in a wide range of applications. A large order parameter is desirable to maximize the change in properties induced by an external stimulus. A set of photochromic and nonphotochromic dyes were investigated for these applications. It was found that a bent‐shaped 7‐substituted dihydroazulene (DHA) photoswitch exhibited liquid‐crystalline properties. Further investigation demonstrated that this material actually followed two distinct reaction pathways on heating, to a deactivated form by a 1,5‐sigmatropic shift and to a linear 6‐substituted DHA. In addition, elimination of hydrogen cyanide from the photoactive DHA gave both bent and linear azulene dyes. In a nematic host that has no absorbance around 350 nm, it was found that only the linear DHA derivative has nematic properties; however, both 6‐ and 7‐substituted DHAs were found to have large order parameters. In the nematic host, ring opening of either DHA to the corresponding vinylheptafulvene resulted in a decrease in dichroic order parameter and an unusually fast back‐reaction to a mixture of both DHAs. Likewise, only the linear azulene derivative showed mesomorphic properties. In the same nematic host, large order parameters were also observed for these dyes.
Synthesis, Biological Evaluation, and Molecular Docking Studies on the DNA Binding Interactions of Platinum(II) Rollover Complexes Containing Phosphorus Donor Ligands
Authors: Fereidoonnezhad Masood , Niazi Maryam , Shahmohammadi Beni Mahnaz , Mohammadi Shima , Faghih Zeinab , Faghih Zahra , Shahsavari Hamid R.
Published: February 2017

Cyclometalated rollover complexes of the type [PtMe(κ2N,C‐bipyO‐H)(L)] [bipyO‐H=cyclometalated 2,2′‐bipyridine N‐oxide; L=tricyclohexylphosphine (PCy3, 2 a), 2‐(diphenylphosphino)pyridine (PPh2py, 2 b), P(OPh)3 (2 c)] were synthesized by treating [PtMe(κ2N,C‐bipyO‐H)(SMe2)] (1) with various monodentate phosphine and phosphite ligands. These complexes were characterized by NMR spectroscopy, and the structure of 2 a was confirmed by single‐crystal X‐ray diffraction. Complex 1 was treated with bis(diphenylphosphino)methane (dppm) at a 1:1 ratio to give the corresponding [PtMe(κ2N,C‐bipyO‐H)(κ1P‐dppm)] (3 b) complex, in which the dppm ligand acts as a monodentate pendant ligand. The biological activities of these complexes were evaluated against a panel of four standard cancer cell lines: lung carcinoma (A549), ovarian carcinoma (OV‐90 and SKOV3), and breast carcinoma (MCF‐7). Complexes 2 c and especially 3 b indicated effective potent cytotoxic activity regarding the cell lines. Electrophoresis mobility shift assays and molecular‐modeling investigations were performed to determine the specific binding mode and the binding orientation of these alkylating agents to DNA. Detection of cellular reactive oxygen species was also determined.
Engineering of Optically Encoded Microbeads with FRET‐Free Spatially Separated Quantum‐Dot Layers for Multiplexed Assays
Authors: Bilan Regina S. , Krivenkov Victor A. , Berestovoy Mikhail A. , Efimov Anton E. , Agapov Igor I. , Samokhvalov Pavel S. , Nabiev Igor , Sukhanova Alyona
Published: February 2017

Quantum dot (QD) encoded microbeads are emerging for multiplexed analysis of biological markers. The quantitative encoding of microbeads prepared with different concentrations of QDs of different colors suffers from resonance energy transfer from the QDs fluorescing at shorter wavelengths to the QDs fluorescing at longer wavelengths. Here, we used the layer‐by‐layer deposition technique to spatially separate QDs of different colors with several polymer layers so that the distance between them would be larger than the Förster energy transfer radius. We performed fluorescence lifetime measurements to investigate and determine the conditions excluding significant resonance energy transfer between QDs within QD‐encoded microbeads. Additionally, the number of QDs adsorbed onto microbeads was systematically established and multilayer structures of the QD‐encoded microbead shells were characterized by scanning probe nanotomography. Finally, we prepared eight populations of FRET‐free microbeads encoded with QDs of three colors at two intensity levels and demonstrated that all the optical codes are excitable at a single wavelength and may be clearly identified in three channels of a flow cytometer. The developed approach for engineering QD‐encoded microbeads that are free from optical artefacts related to inter‐QD resonance energy transfer paves the way to quantitative QD‐based multiplexed assays.
Mobile payments in global markets using biometrics and cloud
Authors: Pal Doyel , Khethavath Praveenkumar , Chen Tingting , Zhang Yuan
Published: February 2017

Payment methods using mobile devices instead of using traditional methods (cash, credit card, etc) has been gaining popularity all over the world. The ubiquitous nature of smartphones and tablets has widened the ambit for using these devices for payments and other daily life activities. Recent advancements in mobile technology along with the convenience of mobile devices made these applications possible. Despite the worldwide user adoption of mobile applications, security is the key challenge in mobile banking and payments system. Mobile payments systems need to be very efficient and provide utmost security endlessly. State‐of‐the‐art mobile payment systems need the physical presence of a merchant agent to make a payment. In this article, we had described in detail about the design and implementation of a mobile payments application, used to make in‐store purchases and make secure payments without any physical presence of a cashier or a merchant agent. We proposed a novel privacy‐preserving and secure authentication algorithm to make mobile payments using biometrics. The analysis and experimental results show the reliability and efficiency of our proposed solution.
Case against Harvard and MIT over web access moves forward; DOJ stalls on regulations
Authors: Charmatz Marc
Published: February 2017

Colleges and universities have received mixed signals on when and whether they need to provide equal access for deaf and hard‐of‐hearing individuals to the audio and audiovisual content that they make available online to the general public by providing captioning.
Invite a range of participants for an effective advisory board
Authors: Carey Trudy
Published: February 2017

When I was asked to start an advisory board for our office, I immediately put the project on the bottom of my “to do” list. I am not a procrastinator unless I find myself trying to do something that I don't know how to do, and I had no idea how to create an advisory board. I didn't know who to invite to be on the board, and I didn't know what to do with a board once I created it. As I reached out for advice, I was told to contact the dean of each college to ask for a recommendation for a faculty member from their college.
A p57 conditional mutant allele that allows tracking of p57‐expressing cells
Authors: Mademtzoglou Despoina , Alonso‐Martin Sonia , Chang Ted Hung‐Tse , Bismuth Keren , Drayton‐Libotte Bernadette , Aurade Frédéric , Relaix Frédéric
Published: February 2017

p57Kip2 (p57) is a maternally expressed imprinted gene regulating growth arrest which belongs to the CIP/KIP family of cyclin‐dependent kinase inhibitors. While initially identified as a cell cycle arrest protein through inhibition of cyclin and cyclin‐dependent kinase complexes, p57 activity has also been linked to differentiation, apoptosis, and senescence. In addition, p57 has recently been shown to be involved in tumorigenesis and cell fate decisions in stem cells. Yet, p57 function in adult tissues remains poorly characterized due to the perinatal lethality of p57 knock‐out mice. To analyze p57 tissue‐specific activity, we generated a conditional mouse line (p57FL‐ILZ/+) by flanking the coding exons 2–3 by LoxP sites. To track p57‐expressing or mutant cells, the p57FL‐ILZ allele also contains an IRES‐linked β‐galactosidase reporter inserted in the 3′ UTR of the gene. Here, we show that the β‐galactosidase reporter expression pattern recapitulates p57 tissue specificity during development and in postnatal mice. Furthermore, we crossed the p57FL‐ILZ/+ mice with PGK‐Cre mice to generate p57cKO‐ILZ/+ animals with ubiquitous loss of p57. p57cKO‐ILZ/+ mice display developmental phenotypes analogous to previously described p57 knock‐outs. Thus, p57FL‐ILZ/+ is a new genetic tool allowing expression and functional conditional analyses of p57.
Oxidative Addition of Aryl Halides to Cationic Bis(phosphane)rhodium Complexes: Application in C–C Bond Formation
Authors: König Anja , Fischer Christian , Alberico Elisabetta , Selle Carmen , Drexler Hans‐Joachim , Baumann Wolfgang , Heller Detlef
Published: February 2017

The oxidative addition of chloro‐, bromo‐ and iodobenzene to the cationic bis(phosphane)rhodium complex [Rh(DIPAMP)(MeOH)2]BF4 was investigated. The resulting complexes were characterized by X‐ray analysis and NMR spectroscopy and applied as catalysts in classical cross‐coupling reactions. Product inhibition was observed and quantified by UV/Vis and NMR spectroscopy.
A continuous single organic phase process for the lipase catalyzed synthesis of peroxy acids increases productivity
Authors: Meyer Janine , Horst Angelika E. W. , Steinhagen Max , Holtmann Dirk , Ansorge‐Schumacher Marion B. , Kraume Matthias , Drews Anja
Published: February 2017

The design of an optimal process is particularly crucial when the reactants deactivate the biocatalyst. The reaction cascades of the chemo‐enzymatic epoxidation where the intermediate peroxy acid is produced by an enzyme are still limited by enzyme inhibition and deactivation by hydrogen peroxide.

To avoid additional effects caused by interfaces (aq/org) and to reduce the process limiting deactivation by the substrate hydrogen peroxide, a single‐phase concept was applied in a fed‐batch and a continuous process (stirred tank), without the commonly applied addition of a carrier solvent. The synthesis of peroxyoctanoic acid catalyzed by Candida antarctica lipase B was chosen as the model reaction.

Here, the feasibility of this biocatalytic reaction in a single‐phase system was shown for the first time. The work shows the economic superiority of the continuous process compared to the fed‐batch process. Employing the fed‐batch process reaction rates up to 36 mmol h−1 per gramcat, and a maximum yield of 96 % was achieved, but activity dropped quickly. In contrast, continuous operation can maintain long‐term enzyme activity. For the first time, the continuous enzymatic reaction could be performed for 55 h without any loss of activity and with a space‐time yield of 154 mmol L−1 h−1, which is three times higher than in the fed‐batch process. The higher catalytic productivity compared to the fed‐batch process (34 vs. 18 gProd g−1cat) shows the increased enzyme stability in the continuous process.
Contribution of ATM and ATR kinase pathways to p53‐mediated response in etoposide and methyl methanesulfonate induced DNA damage
Authors: Sun Bin , Ross Susan M. , Rowley Sean , Adeleye Yeyejide , Clewell Rebecca A.
Published: February 2017

p53 is a key integrator of cellular response to DNA damage, supporting post‐translational repair and driving transcription‐mediated responses including cell cycle arrest, apoptosis, and repair. DNA damage sensing kinases recognize different types of DNA damage and initiate specific responses through various post‐translational modifications of p53. This study evaluated chemical specificity of the p53 pathway response by manipulating p53 or its upstream kinases and assessing the effect on DNA damage and cellular responses to prototype chemicals: etoposide (ETP, topoisomerase II inhibitor) and methyl methane sulfonate (MMS, alkylating agent). p53‐deficient cells demonstrated reduced accumulation of the p53 target proteins MDM2, p21, and Wip1; reduced apoptotic response; and increased DNA damage (p‐H2AX and micronuclei) with both chemicals. However, p53 was not essential for cell cycle arrest in HT1080 or HCT116 cells. The two chemicals induced different patterns of kinase activation, particularly in terms of Chk 1, Chk 2, p38, and ERK 1/2. However, inhibition of the ATM pathway showed a greater effect on p53 activtation, apoptosis, and accumulation of DNA damage than ATR‐Chk 1 or the MAP kinases regardless of the chemical used. These results indicate that ATM is the predominant upstream kinase responsible for activation of the p53‐mediated DNA damage response for both MMS and ETP, though the downstream kinase response is markedly different. Environ. Mol. Mutagen. 58:72–83, 2017. © 2017 Wiley Periodicals, Inc.
Comprehensive genomic and phenotypic characterization of germline FH deletion in hereditary leiomyomatosis and renal cell carcinoma
Authors: Vocke Cathy D. , Ricketts Christopher J. , Merino Maria J. , Srinivasan Ramaprasad , Metwalli Adam R. , Middelton Lindsay A. , Peterson James , Yang Youfeng , Linehan W. Marston
Published: February 2017

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a familial cancer syndrome associated with the development of cutaneous and uterine leiomyomas, and an aggressive form of type 2 papillary kidney cancer. HLRCC is characterized by germline mutation of the FH gene. This study evaluated the prevalence and clinical phenotype of FH deletions in HLRCC patients. Patients with phenotypic manifestations consistent with HLRCC who lacked detectable germline FH intragenic mutations were investigated for FH deletion. A series of 28 patients from 13 families were evaluated using a combination of a comparative genomic hybridization (CGH) array and/or CLIA‐approved FH deletion/duplication analyses. Thirteen distinct germline deletions were identified in the 13 UOB families, including 11 complete FH gene deletions and 2 partial FH gene deletions. The size of eight evaluated complete FH deletions varied from ∼4.74 Mb to 249 kb, with all deletions resulting in additional gene losses. Two partial FH gene deletions were identified, with one resulting in loss of exon 1 and the upstream region of the FH gene only. Kidney cancer was diagnosed in 9 (32%) of 28 patients and 7 (54%) of 13 families possessing either complete or partial FH deletions. Cutaneous and uterine leiomyomas were observed at similar rates to those in FH point mutation families. Complete or partial FH gene alterations in HLRCC families are associated with all of the canonical HLRCC manifestations, including type 2 papillary kidney cancer and should be screened for in any patient at‐risk for this disorder.