bluuebunny/crossref_metadata_2025 huggingface dataset:
Fingerprints of changes in the terrestrial carbon cycle in response to large reorganizations in ocean circulation
Authors: Bozbiyik A. , Steinacher M. , Joos F. , Stocker T. F. , Menviel L.
Published: March 2011

Abstract. CO2 and carbon cycle changes in the land, ocean and atmosphere are investigated using the comprehensive carbon cycle-climate model NCAR CSM1.4-carbon. Ensemble simulations are forced with freshwater perturbations applied at the North Atlantic and Southern Ocean deep water formation sites under pre-industrial climate conditions. As a result, the Atlantic Meridional Overturning Circulation reduces in each experiment to varying degrees. The physical climate fields show changes qualitatively in agreement with results documented in the literature, but there is a clear distinction between northern and southern perturbations. Changes in the physical variables, in turn, affect the land and ocean biogeochemical cycles and cause a reduction, or an increase, in the atmospheric CO2 concentration by up to 20 ppmv, depending on the location of the perturbation. In the case of a North Atlantic perturbation, the land biosphere reacts with a strong reduction in carbon stocks in some tropical locations and in high northern latitudes. In contrast, land carbon stocks tend to increase in response to a southern perturbation. The ocean is generally a sink of carbon although large reorganizations occur throughout various basins. The response of the land biosphere is strongest in the tropical regions due to a shift of the Intertropical Convergence Zone. The carbon fingerprints of this shift, either to the south or to the north depending on where the freshwater is applied, can be found most clearly in South America. For this reason, a compilation of various paleoclimate proxy records of Younger Dryas precipitation changes are compared with our model results. The proxy records, in general, show good agreement with the model's response to a North Atlantic freshwater perturbation.
Yolk‐like Micro/Nanoparticles with Superparamagnetic Iron Oxide Cores and Hierarchical Nickel Silicate Shells
Authors: Fang Qunling , Xuan Shouhu , Jiang Wanquan , Gong Xinglong
Published: March 2011

Yolk‐like nano/microparticles with superparamagnetic iron oxide (SPIO) cores and hierarchical nickel silicate (NS) shells, designated yolk SPIO@NS, are fabricated by combining the versatile sol–gel process and the hydrothermal reaction, involving the coating of SPIO particles with SiO2 and transformation of the SiO2 shells into NS hollow spheres with hierarchical nanostructures. Various yolk/shell nanostructures with tunable NS shell thicknesses and SPIO core sizes are successfully prepared by controlling the experimental para­meters. Au nanoparticles can be impregnated into the yolk‐like microspheres in situ to form SPIO@NS/Au composite particles and the as‐prepared magnetic nanocatalysts show good catalytic activity, using the catalytic reduction of RhB as a model reaction. This facile method can be extended to the synthesis of other encapsulated particles with yolk‐like nanostructure.
Low‐Power and High‐Contrast Nanoscale All‐Optical Diodes Via Nanocomposite Photonic Crystal Microcavities
Authors: Hu Xiaoyong , Li Zhiqiang , Zhang Jiaxiang , Yang Hong , Gong Qihuang , Zhang Xinping
Published: March 2011

A novel nanoscale integrated all‐optical diode is reported, realized by combining the strong plasmonic responses of gold nanoparticles with the all‐optical tunable properties of polymeric photonic crystal microcavities. Non‐reciprocal transmission properties are achieved based on the effect of surface‐plasmon resonance enhancing the optical non‐linearity and dynamic coupling of asymmetrical microcavity modes. An ultralow‐threshold photon intensity of 2.1 MW cm−2 and an ultrahigh transmission contrast over 104 are realized simultaneously. Compared with previously reported all‐optical diodes, the operating power is reduced by five orders of magnitude, while the transmission contrast is enlarged by three orders of magnitude.
Physical activity patterns in French youth—From childhood to adolescence—Monitored with high‐frequency accelerometry
Authors: Blaes AuréLie , Baquet Georges , Van Praagh Emmanuel , Berthoin Serge
Published: March 2011

Objectives:

To investigate changes in time spent in light (LPA), moderate (MPA), vigorous (VPA), very high physical activity (VHPA) from childhood to adolescence, according to age and sex, when measured with high frequency accelerometry.

Methods:

Three hundred and sixty‐one children, 94 preschoolers (Ps), 156 from primary schools (PS) and 111 from junior high schools (JHS)) were involved in this study. The children's physical activity was assessed with a uniaxial accelerometer over a seven‐day period. The epoch duration was set at 5 s and data collected between 7 am and 9 pm. The times spent below and above different PA thresholds, corresponding from LPA (<3 METs) to VHPA (>9 METs), were calculated.

Results:

During the week, the boys spent significantly more time in MPA to VHPA than the girls (p < 0.001). From Ps to PS, LPA remained stable, while VPA and VHPA decreased significantly (p < 0.05). From PS to JHS, time spent in LPA, VPA, and VHPA increased significantly (p < 0.05). On the contrary, MPA increased significantly (p < 0.05) between Ps and PS and decreased significantly (p < 0.05) from PS to JHS. From PS to JHS, time spent in LPA increased significantly more during free days than during school days (p < 0.05) while VPA and VHPA increased significantly (p < 0.05) more during school days than during free days.

Conclusions:

Moderate to very high PA decreased from childhood to adolescence. Changes in PA patterns were associated with an increase of LPA and a concomitant decrease of MPA, while changes were more pronounced during free days than during school days. Am. J. Hum. Biol. 2011. © 2011 Wiley‐Liss, Inc.
Right hand digit ratio (2D:4D) is associated with oral cancer
Authors: NicolÁs Hopp Renato , Jorge Jacks
Published: March 2011

Finger length ratio has been proposed as a putative marker for prenatal hormone exposure, as well as the action of HOX, AR, and a variant of the LIN28b genes. These genes have been recently connected to carcinogenesis and digit ratio could help to identify patients with this predisposition.

Objectives:

The purpose of this study was to investigate the possible correlations between digit ratio, oral squamous cell carcinoma (OSCC)—the most common oral cancer—and oral premalignant lesions (OPLs) in tobacco‐consuming males, the main risk group for this disease.

Methods:

Digital images of the right hands of patients diagnosed with OSCC (n = 25), OPLs (n = 25), and age‐matched controls (n = 25) were obtained. Fingers were measured using Adobe Photoshop® and the mean ratios between the 2nd and 4th digits were compared. Data were analyzed by ANOVA (α = 0.05).

Results:

Risk factors (alcohol and tobacco consumption, familial history) were similar between the three study groups. Males in the OSCC group presented significantly higher digit ratio (P = 0.03) in comparison with males with OPLs and individuals without oral lesions.

Conclusions:

According to the results, males with the higher digit ratio seem to be more prone to undergo malignization of lesions in the oral cavity. Similar deleterious habits for the three groups allows us to infer that digit ratio could add to the research of etiological factors and be a putative marker for the screening of patients' susceptibility to develop oral squamous cell carcinoma. Am. J. Hum. Biol. 2011. © 2011 Wiley‐Liss, Inc.
White matter changes in basis pontis in small expansion FMR1 allele carriers with parkinsonism
Authors: Loesch D.Z. , Kotschet K. , Trost N. , Greco C.M. , Kinsella G. , Slater H.R. , Venn A. , Horne M.
Published: March 2011

Examples of white matter hyperintensities (wmh) on magnetic resonance images in a basis pontis are presented in two male carriers, each of whom carry a small CGG expansion fragile X mental retardation (FMR1) allele. One carried a premutation (PM) allele of 85 CGG repeats and the other, a gray zone (GZ) allele of 47 repeats. Both were originally diagnosed with idiopathic Parkinson's disease (iPD). Similar changes are also shown in one PM carrier of 99 repeats affected with mild tremor and imbalance, who was ascertained through a fragile X syndrome family. These examples draw attention to the occurrence of wmh in a basis pontis in the carriers of small CGG expansions presenting with tremor and ataxia. Moreover, the presence of this change in GZ, as well as PM, allele carriers originally diagnosed with iPD supports our earlier suggestion that both these alleles may contribute to the neurodegenerative changes in this disorder which, in the examples presented, have been reflected by wmh, most prominent in the cerebellar peduncles and/or pontine area. © 2011 Wiley‐Liss, Inc.
Direct adaptive fuzzy control with membership function tuning
Authors: Moradi Morteza , Kazemi Mohammad Hosein , Ershadi Elnaz
Published: March 2011

In this paper, a direct self‐structured adaptive fuzzy control is introduced for the class of nonlinear systems with unknown dynamic models. Control is accomplished by an adaptive fuzzy system with a fixed number of rules and adaptive membership functions. The reference signal and state errors are used to tune the membership functions and update them instantaneously. The Lyapunov synthesis method is also used to guarantee the stability of the closed loop system. The proposed control scheme is applied to an inverted pendulum and a magnetic levitation system, and its effectiveness is shown via simulation.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Fluorescence‐PCR assays and isolation of luminescent bacterial clones using an automated plate reader
Authors: Crowley Thomas E.
Published: March 2011

The genes responsible for luminescence in various species of the marine microorganism Photobacterium, have been used for many years as a tool by researchers and instructors. In particular, the lux operon of Photobacterium fischeri has been used by many instructors to teach recombinant DNA techniques. Two methods using an automated plate reader and multiwell plates were applied to a set of previously‐published exercises. In these exercises that involve transfer of lux genes to Escherichia coli to create a luminescent phenotype, this technology was used to screen for Lux+ colonies. It was found to be more convenient and more sensitive than the previously used method; that is, assaying bacterial plates by direct observation. Eight students synthesized four genomic libraries and isolated six Lux+ clones. The fluorescent‐detection feature of the plate reader was used to verify amplification of target sequence in polymerase chain reaction (PCR) reactions. Lux+ E. coli colony lysates were examined. An exonuclease‐activated, fluorescent DNA probe generated a signal on hybridization to an amplified portion of the luxA gene in each lysate tested. This method is suggested as a means of demonstrating the concept of real‐time PCR without the expense of the specialized device typically used for this technique. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 126–132, 2011
Analysis of a SNP linked to lactase persistence: An exercise for teaching molecular biology techniques to undergraduates
Authors: Schultheis Patrick J. , Bowling Bethany V.
Published: March 2011

Recent experimental evidence indicates that the ability of adults to tolerate milk, cheese, and other lactose‐containing dairy products is an autosomal dominant trait that co‐evolved with dairy farming in Central Europe about 7,500 years ago. Among persons of European descent, this trait is strongly associated with a C to T substitution at a polymorphic site 13,910 bp upstream of the lactase gene. This mutation results in the persistent expression of lactase into adulthood enabling individuals carrying a T−13,910 allele to digest lactose as adults. In this report, we describe a laboratory exercise for an undergraduate molecular biology course in which students determine their own genotype at the −13,910 polymorphic site and correlate this with their ability to tolerate dairy products. The exercise is used as a tool to teach basic molecular biology procedures such as agarose gel electrophoresis, PCR1, and DNA sequencing. Students are actively engaged in the learning process, not only by analyzing their own DNA but also by applying their knowledge and skills to answer an authentic question. The exercise is also integrated with lecture material on the control of gene expression at the transcriptional level, in particular, how transcription factors can influence the activity of a promoter by binding to cis‐acting DNA regulatory elements located within the proximal promoter of a gene or distant enhancer regions. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 133–140, 2011
Purification and analysis of colorful hypothetical open reading frames: An inexpensive gateway laboratory
Authors: DeSantis Kara A. , Reinking Jeffrey L.
Published: March 2011

This laboratory exercise is an inquiry‐based investigation developed around the core experiment where students, working alone or in groups, each purify and analyze their own prescreened colored proteins using immobilized metal affinity chromatography (IMAC). Here, we present reagents and protocols that allow 12 different proteins to be purified in parallel without specialized equipment and within a 2.5‐ to 3‐hour undergraduate teaching laboratory. The visual feedback of purifying a colored biomolecule provides real‐time emphasis of the power and simplicity of recombinant DNA technology and IMAC. As presented here in its simplest form, this laboratory occupies two laboratory periods: purification followed by SDS‐PAGE analysis. As such, it can be easily inserted into the existing curriculum of a Biochemistry, Molecular Biology, Biotechnology, or even Genetics course to illustrate core concepts of central dogma and protein purification. Furthermore, the proteins in hand at the end of this 2‐week module can also be used for follow‐up experiments tailored to the needs, timeframe, and facilities available. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 141–144, 2011
An approach to teaching general chemistry II that highlights the interdisciplinary nature of science
Authors: Sumter Takita Felder , Owens Patrick M.
Published: March 2011

The need for a revised curriculum within the life sciences has been well‐established. One strategy to improve student preparation in the life sciences is to redesign introductory courses like biology, chemistry, and physics so that they better reflect their disciplinary interdependence. We describe a medically relevant, context‐based approach to teaching second semester general chemistry that demonstrates the interdisciplinary nature of biology and chemistry. Our innovative method provides a model in which disciplinary barriers are diminished early in the undergraduate science curriculum. The course is divided into three principle educational modules: 1) Fundamentals of General Chemistry, 2) Medical Approaches to Inflammation, and 3) Neuroscience as a connector of chemistry, biology, and psychology. We accurately anticipated that this modified approach to teaching general chemistry would enhance student interest in chemistry and bridge the perceived gaps between biology and chemistry. The course serves as a template for context‐based, interdisciplinary teaching that lays the foundation needed to train 21st century scientists. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 110–116, 2011
Case study: Using microbe molecular biology for Gulf oil spill clean up
Authors: Jones Daniel R.
Published: March 2011

This case has the student actively investigate the regulation of expression of a novel bacterial gene in the context of attempts to solve a real world problem, clean up of the April 2010 Deep Water Horizon oil spill in the Gulf of Mexico. Although the case is fictitious, it is based on factual gene regulatory characteristics of oil‐degrading microbes. The case is written for a sophomore Cell Biology lecture course at Indiana Wesleyan University that is taught to Biology/Pre‐Med majors. This study is also appropriate for use in undergraduate microbiology, biochemistry, molecular biology, and molecular genetics courses. The case is intended to enhance coverage of transcription, translation, control of gene expression, and selected molecular biology techniques. Opportunities to practice critical thinking skills and to a lesser extent an introduction to the paradigm of life science research at the industry level are provided. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 157–164, 2011
Hypothetical biotechnology companies: A role‐playing student centered activity for undergraduate science students
Authors: Chuck Jo‐Anne
Published: March 2011

Science students leaving undergraduate programs are entering the biotechnology industry where they are presented with issues which require integration of science content. Students find this difficult as through‐out their studies, most content is limited to a single subdiscipline (e.g., biochemistry, immunology). In addition, students need knowledge of the ethical, economic, and legal frame work in which the industry operates. This article presents an approach to deliver these outcomes in a collaborative and active learning modality which promotes deep learning. In the model, groups of final year undergraduate students form hypothetical biotechnology companies and identify real issues of interest to industry, make integrative team decisions, use professional level technology, and develop appropriate communication skills. The final successful teaching paradigm was based on self reflection, observation, and student feedback to ensure appropriate attainment of content, group work skills and increased confidence in professional decision‐making. It is these outcomes which will facilitate life long learning skills, a major outcome applicable for all tertiary education. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 173–179, 2011
Analysis of chromatin organisation
Authors: Szeberényi József
Published: March 2011

Terms to be familiar with before you start to solve the test: chromatin, nucleases, sucrose density gradient centrifugation, melting point, gel electrophoresis, ethidium bromide, autoradiography, Southern blotting, Northern blotting, Sanger sequencing, restriction endonucleases, exonucleases, linker DNA, chloroform extraction, nucleosomes, nucleosomal histones, histone H1, nonhistone proteins, laminin, lamin, solenoid, DNA methylation, CpG islands, histone acetylation, centromere, histone octamers, “beads‐on‐a‐string”, euchromatin, heterochromatin. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 165–167, 2011
Vision and change in biology undergraduate education: Vision and change from the funding front
Authors: Holm Bethany , Carter Virginia Celeste , Woodin Terry
Published: March 2011

The purpose of this short article is to (a) briefly summarize the findings of two important recent resources concerning the future of biology in the 21st century; one, Vision and Change, A Call to Action [AAAS, 2009. AAAS, Washington, DC], concerned with undergraduate education in biology, the other, A New Biology for the 21st Century [National Research Council, 2009. National Academies Press, Washington, DC], concerned with advances within the discipline itself; (b) urge you, the reader of BAMBED, to review the material on the Vision and Change website [AAAS, 2009. AAAS: Washington, DC] and then to think how you might change things at your own institution and within your courses, and; (c) make readers aware of the programs at the National Science Foundation (NSF) that might support change efforts, as well as refer you to efforts other funding agencies are making to help biology undergraduate education respond to the challenges and opportunities chronicled in these two reports. Although NSF funding opportunities are specifically available to US investigators, the recommendations of the two reports should be of interest to a wide spectrum of international researchers. Biochemistry and Molecular Biology Education Vol. 39, No. 2, pp. 87–90, 2011
Integration of computational fluid dynamics into a fluid mechanics curriculum
Authors: Adair D. , Jaeger M.
Published: March 2011

The development, implementation and evaluation of a suitable curriculum for students to use computational fluid dynamics as part of a fluid mechanics course at intermediate undergraduate level are described. Evaluation of successful learning outcomes is made to confirm the effectiveness of the interface as a suitable educational tool for students at intermediate undergraduate level. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22: 131–141, 2014
Preference stability belief as a determinant of response to personalized recommendations
Authors: Shen Anyuan , Ball A. Dwayne
Published: March 2011

Preference stability refers to the objectively measured choice consistency among options with different attribute values in the same product category. We suggest that a consumer's subjectively held belief of preference stability may be an important determinant of response to personalized recommendations. Experimental results confirm that preference stability belief moderates the effect of customization on the evaluation of recommendation accuracy and receptiveness to the learning relationship. Customization will produce stronger effects on accuracy evaluation and receptiveness for subjects with high preference stability belief than for subjects with low preference stability belief. Customers who believe their preferences are stable appreciate customized recommendations more, notice more acutely whether recommendations are customized or not, and are more receptive to the learning relationship when recommendations are customized than when not. Customers who believe their own preferences are less stable do not appreciate customized recommendations as much, are less sensitive to whether recommendations are customized or not, and are not more receptive to the learning relationship even when recommendations are customized. Theoretical and managerial implications of our findings are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Selective Adsorption of Co(II) by Mesoporous Silica SBA‐15‐Supported Surface Ion Imprinted Polymer: Kinetics, Isotherms, and Thermodynamics Studies
Authors: Liu Yan , Liu Zhanchao , Dai Jiangdong , Gao Jie , Xie Jimin , Yan Yongsheng
Published: March 2011

A novel surface ion imprinted adsorbent [Co(II)‐IIP] using polyethyleneimine (PEI) as function monomer and ordered mesoporous silica SBA‐15 as support matrix was prepared for Co(II) analysis with high selectivity. The prepared polymer was characterized by Fourier transmission infrared spectrometry, scanning electron microscopy, X‐ray diffraction and nitrogen adsorption‐desorption isotherm. Bath experiments of Co(II) adsorption onto Co(II)‐IIP were performed under the optimum conditions. The experimental data were analyzed by pseudo‐first‐order and pseudo‐second‐order kinetic models. It was found that the pseudo‐second‐order model best correlated the kinetic data. The intraparticle diffusion and liquid film diffusion were applied to discuss the adsorption mechanism. The results showed that Co(II) adsorption onto IIP was controlled by the intraparticle diffusion mechanism, along with a considerable film diffusion contribution. Langmuir, Freundlich and Dubinin‐Radushke‐ vich adsorption models were applied to determine the isotherm parameters. Langmuir model fitted the experiment data well and the maximum calculated capacity of Co(II) reached 39.26 mg/g under room temperature. The thermodynamic data were indicative of the spontaneousness of the endothermic sorption process of Co(II) onto Co(II)‐IIP. Co(II)‐IIP showed high affinity and selectivity for template ion compared with non imprinted polymer (NIP).
A New Organic‐Inorganic Hybrid Copper Pentaborate with Free Boric Acid Group
Authors: Lin Dan , You Xiaoyan , Zhu Lixia
Published: March 2011

The hydrothermal reaction of Cu(CH3COO)2·H2O, H3BO3, ethylenediamine and H2O in a molar ratio of 3:20:9:222 at 140°C for 5 d yields the deep blue crystals of a new copper polyborate [Cu(en)2B(OH)3]· [B5O5(OH)7] (enH2NCH2CH2NH2) in 70% yield. It crystallizes in monoclinic system, space group P21/c, with unit cell dimensions, a=1.2779(2) nm, b=1.0167(15) nm, c=1.5019(2) nm, β=90.30(2)°, Z=4. The crystal structure of this compound consists of [Cu(en)2B(OH)3]2+ cation and [B5O5(OH)7]2− anion, which are linked together through hydrogen bonding interactions and electrostatic forces, forming an interesting three‐dimensional framework. The [B5O5(OH)7]2− anion is constituted of [B4O5(OH)4]2− anion and discrete B(OH)3 group which attaches to the side of [B4O5(OH)4]2− through intramolecular hydrogen bonds. Fundamental vibrational modes of this compound were identified and band assignments were made. The middle bands observed at 882 and 575 cm−1 in Raman spectrum are the characteristic peak of B(OH)3 group and [B4O5(OH)4]2− anion, respectively. Additionally the thermal behavior of title compound was recorded and its decomposition mechanism was discussed.
Synthesis, Antiproliferative Activity and DNA‐Binding Properties of Nitrogen and Sulfur Heterocyclic Norcantharidin Acylamide Acid
Authors: Wang Na , Wang Yunyun , Wang Xiaoxia , Zheng Xiaoliang , Yan Dongmeic , Lin Qiuyue
Published: March 2011

Three novel norcantharidin acylamide acids (L1N‐thiadiazole norcantharidin acylamide acid, C10H11N3O4S; L2N‐thiazole norcantharidin acylamide acid, C11H12N2O4S and L3N‐benzothiazole norcantharidin acylamide acid, C15H14N2O4S) were synthesized by the reactions of norcantharidin (NCTD7‐oxabicyclo[2,2,1]heptane‐2,3‐dicarboxylic acid anhydride, C8H8O4) with 2‐amino‐1,3,4‐thiadiazole (C2H3N3S), 2‐aminothiazole (C3H4N2S) and 2‐aminobenzothiazole (C7H6N2S), respectively. Their structures were characterized by elemental analysis, IR, and NMR. The inhibition rates of L3 was much higher than those of L1 and L2 against human hepatoma cells SMMC7721 cell lines in vitro. The interaction between the compounds and DNA was studied by means of fluorescence quenching studies and viscosity measurements. The emission intensities decreased obviously with increasing concentration of the compounds in the fluorescence quenching experiments. The linear Stern‐Volmer quenching constant Ksq values were 0.62 (L1), 0.55 (L2) and 1.08 (L3), respectively. The binding abilities followed the trend from high to low were L3, L1 and L2, respectively. The results of viscosity measurements showed that L1 and L2 might bind to DNA via partial intercalation, while L3 bound mainly in intercalation.
Synthesis and Spectral Properties of Novel Water‐soluble Indocyanine Dyes as Fluorescent Dyes for Proteins Detection
Authors: Fu Yile , Wang Lanying , Zhang Xianghan , Lu Tianqin , Xie Qianjie , Shi Zhen
Published: March 2011

Two novel water‐soluble indocyanine dyes were synthesized. Their chemical structures were confirmed by 1H NMR, IR, MS and UV‐vis techniques. The absorptions of the prepared dyes in different solvents were measured. Two dyes exhibited negative solvatochromism, with a blue shift of the absorption and an emission maximum in (bovine serum albumin) protonic solvent relative to non protonic solvent. The fluorescence properties of the dyes in both free state and BSA were investigated. Significant enhancement of the fluorescence intensity for the Dye2 was observed in the presence of BSA. Dye2 could be proposed as fluorescent dyes for BSA detection in aqueous solution.
An Efficient, Three‐component One‐pot Preparation of 1,4‐Dihydropyridines Containing Novel Substituted Pyrazole under Sulfamic Acid Catalysis
Authors: Li Jianping , Qiu Jikuan , Li Huijuan , Zhang Guisheng
Published: March 2011

An efficient approach to 1,4‐dihydropyridines containing novel substituted pyrazole is achieved via three‐component reaction of pyrazolyl aldehyde, β‐ketoester, and ammonium acetate in one‐pot under sulfamic acid catalysis.
Resonance Scattering Effect of Dopamine Product Particle and Its Application to Polyphenoloxidase Activity Assay
Authors: Jiang Caina , Ling Shaoming , Liang Aihui , Ouyang Xiahui , Wang Pengfei , Jiang Zhiliang
Published: March 2011

In pH 7.2 Na2HPO4‐NaH2PO4 buffer solution, polyphenoloxidase (PPO) could catalyze the oxidization of dopamine (DA) to form polymer particles in dark‐red color, which exhibited a strong resonance scattering (RS) peak at 780 nm. In the chosen conditions, as the PPO activity increased, the RS intensity at 780 nm increased linearly. The increased RS intensity (ΔI780 nm) was linear to the PPO activity in the range of 0.10–6.0 U·mL−1, with a regression equation of ΔI780 nm96.6C+15.1, a relative coefficient of 0.9987 and a detection limit of 0.06 U·mL−1 PPO. The proposed method was applied to detecting PPO activity in potato sample with satisfactory results.
Spectroscopic Studies on the Interaction of Asiatic Acid with Bovine Serum Albumin
Authors: Yao Di , Ni Shouhai , Wen Maogui , Bian Hedong , Yu Qing , Liang Hong , Chen Zhenfeng
Published: March 2011

Fluorescence spectroscopy, Fourier transform infrared (FT‐IR) spectroscopy, circular dichroism (CD) and FT‐Raman spectroscopy were employed to analyze the binding of the asiatic acid (AA) to bovine serum albumin (BSA) under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by AA was the result of the formation of BSA‐AA complex. The fluorescence quenching mechanism of BSA by AA was a static quenching procedure. According to the Van′t Hoff equation, the thermodynamic parameters enthalpy change (ΔH0) and entropy change (ΔS0) for the reaction were evaluated to be −12.55 kJ·mol−1 and 67.08 kJ·mol−1, respectively, indicating that hydrophobic and electrostatic interactions played a major role in stabilizing the complex. The influence of AA on the conformation of BSA has also been analyzed on the basis of FT‐IR, CD and FT‐Raman spectra.
A Novel Fluorescence Quenching Method for the Determination of Aloe Polysaccharide
Authors: Gu Wenxiu , Song Hongyan , Wen Xiaonan , Lu Cunfeng , Xia Wenshui
Published: March 2011

Alizarin red (AR) can bind with aloe polysaccharide (APS) in doubly de‐ionized water to form a red complex resulting in fluorescence quenching of it. The maximum fluorescence quenching wavelength is 572 nm. The chromogenic reaction is rapid and the fluorescence intensity remains stable for at least 2 h at room temperature. The quenched fluorescence intensity (ΔF) is directly proportional to APS concentration. Based on this interaction, a sensitive and selective fluorophotometric method is proposed for the determination of APS. The optimal experiment conditions were established. The corresponding linear equation is (F=0.8807C+1.8132, R2=0.9999. The quantification and detection limits are 0.4752 and 0.1425 µg·mL−1, respectively. The linear range is 0.444–16.65 µg·mL−1 for APS and the mean recovery (100.2±2)%, RSD⩽3%. The effect of various substances on the determination of APS was also investigated in detail, and the results show that most of the studied coexistent substances can be tolerated in considerable amounts. The proposed method is sensitive, simple, fast and suitable for routine assay.
Peroxyoxalate Chemiluminescence Based on Fluorescent Conjugated Polymer for the Determination of Triton X‐100
Authors: Jin Yingqiong , Sun Lilin , Hao Dan , She Rui , Qian Zhangsheng , Zhu Changqing , Xiao Qin
Published: March 2011

A novel peroxyoxalate chemiluminescence system has been designed for the determination of Triton X‐100 (TX‐100), in which a hydrophobic fluorescent conjugated polymer, poly[2,5‐bisnonyloxy‐1,4‐phenylene‐ethynylene‐9,10‐anthrylene] (PPEA) was employed as a fluorophor. A strong enhanced intensity of chemiluminescence (CL) was observed in the presence of TX‐100, due to the improved emission efficiency of PPEA in the presence of TX‐100. Under optimum conditions, the detection range of Triton X‐100 is between 1.0×10−7 and 1.0× 10−4 mol·L−1, with a detection limit at 6.0×10−8 mol·L−1. The relative standard deviation is 2.4% (n=6) for 1.0×10−6 mol·L−1 Triton X‐100. This method provides satisfying results in the detection of TX‐100 in nature water and biological samples with high sensitivity and wide linear range.
Determination of Hydrocortisone in Cosmetics by CdSe/CdS Quantum Dots‐Based Fluoroimmunoassay Using Magnetic Fe3O4/Au Nanoparticles as Solid Carriers
Authors: Wang Xiuling , Wei Lu , Tao Guanhong , Dai Long
Published: March 2011

This work demonstrated the feasibility of detecting hydrocortisone in cosmetics using a novel CdSe/CdS quantum dots‐based competitive fluoroimmunoassay with magnetic core/shell Fe3O4/Au nanoparticles (MCFN) as solid carriers. Hydrocortisone antigen was labeled with the synthesized core/shell CdSe/CdS quantum dots (QDs) to form the antigen‐QDs conjugate. Meanwhile, hydrocortisone antibody was incubated with MCFN and the immobilized antibody was obtained. The immobilized antibody was then mixed sequentially with hydrocortisone and a slightly excess amount of the QDs‐labeled hydrocortisone antigen, allowing their competition for binding with the antibody immobilized on MCFN. The bound hydrocortisone and the antigen‐QDs conjugates on MCFN were removed subsequently after the mixture was applied to a magnetic force. The analyte concentration was obtained by measuring the fluorescence intensity of the unbound hydrocortisone antigen‐QDs conjugates. The proposed method was characterized by simplicity, rapidity, and high sensitivity with a wide linear working range of 0.5 to 15000 pg·mL−1 and a low detection limit of 0.5 pg·mL−1. The proposed method was successfully applied to the determination of hydrocortisone in cosmetics with satisfactory results.
Unexpected Adsorption Capacity of Ca‐deficient Hydroxyapatite in Oil/water System
Authors: Le Yingyi , Yin Anyuan , Dai Weilin , Fan Kangnian
Published: March 2011

Herein, for the first time, we report the unexpected and interesting adsorption capacity of hydroxyapatites to a variety of organics in the presence of water, whose sorption amount could be up to 6 g·g−1.
Correlates of worry about recurrence in a multiethnic population‐based sample of women with breast cancer
Authors: Janz Nancy K. , Hawley Sarah T. , Mujahid Mahasin S. , Griggs Jennifer J. , Alderman Amy , Hamilton Ann S. , Graff John J. , Jagsi Reshma , Katz Steven J.
Published: March 2011

BACKGROUND:

Worry about recurrence (worry) is a persistent concern of breast cancer survivors. Little is known about whether race/ethnicity or healthcare experiences are associated with worry.

METHODS:

Women with nonmetastatic breast cancer diagnosed from June 2005 to February 2007 and reported to Detroit or Los Angeles Surveillance, Epidemiology, and End Results registries were surveyed (mean 9 months postdiagnosis); 2290 responded (73%). Latinas and African Americans were oversampled. A worry scale was constructed as the mean score of 3 items (on 5‐point Likert, higher = more worry): worry about cancer returning to the same breast, occurring in the other breast, or spreading to other parts of the body. Race/ethnicity categories were white, African American, and Latina (categorized into low vs high acculturation). The worry scale was regressed on sociodemographics, clinical/treatment, and healthcare experience factors (eg, care coordination collapsed into low, medium, high).

RESULTS:

Low acculturated Latinas reported more worry and African Americans less worry than whites (P < .001). Other factors independently associated with more worry were younger age, being employed, more pain and fatigue, and radiation (Ps < .05). With all factors in the model, less worry was associated (all Ps < .05) with greater ease of understanding information (2.89, 2.99, 2.81 for low, medium, high), better symptom management (3.19, 2.89, 2.87 for low, medium, high), and more coordinated care (3.36, 2.94, 2.82 for low, medium, high). Race/ethnicity remained significant controlling for all factors (P < .001).

CONCLUSIONS:

Less acculturated Latina breast cancer patients are vulnerable to high levels of worry. Interventions that improve information exchange, symptom management, and coordinating care hold promise in reducing worry. Cancer 2011. © 2011 American Cancer Society.
Pulmonary metastases in patients with recurrent, treatment‐resistant meningioma
Authors: Alexandru Daniela , Glantz Michael J. , Kim Lyndon , Chamberlain Marc C. , Bota Daniela A.
Published: March 2011

BACKGROUND:

Meningioma is the most common extra‐axial primary intracranial tumor in adults that rarely metastasizes outside of the central nervous system (CNS). Among recognized sites of metastases, the lung is the most common, but the importance of lung metastases relative to prognosis is unknown. 111Indium (111In)‐octreotide scintigraphy (octreotide scanning) is a valuable imaging modality with which to evaluate intracranial meningiomas and their response to treatment with somatostatin analogues and has the potential to identify extracranial metastatic disease.

METHODS:

In this retrospective multicenter study, adult patients treated for recurrent meningioma were identified. These patients underwent 111In‐octreotide positron emission tomography/computed tomography imaging (octreotide scintigraphy) and were found to have positive octreotide uptake in their lungs.

RESULTS:

Six cases were identified with recurrent meningioma (after surgery, radiotherapy, and at least 1 chemotherapy agent) and pulmonary lesions by octreotide scintigraphy. Biopsy of a pulmonary lesion in 1 patient confirmed the diagnosis of metastatic meningioma. Patients with metastatic pulmonary involvement identified by 111In‐octreotide scintigraphy in this case series had an overall survival of 6 months, which is less than that reported from previously published series of patients with unknown systemic disease status.

CONCLUSIONS:

111In‐octreotide scintigraphy is useful for assessing both CNS disease and extracranial metastases. The presence of pulmonary metastases appears to negatively affect survival in patients with recurrent meningioma. The usefulness of 111In‐octreotide scintigraphy should be considered in staging patients with recurrent meningioma who are considered for further treatment. A prospective study to confirm this finding is warranted. Cancer 2011;. Published 2011 by the American Cancer Society.
A galectin‐3 sequence polymorphism confers TRAIL sensitivity to human breast cancer cells
Authors: Mazurek Nachman , Byrd James C. , Sun Yunjie , Ueno Suguru , Bresalier Robert S.
Published: March 2011

BACKGROUND:

A common polymorphism, rs4644, coding for Pro64 or His64 of the carbohydrate‐binding protein galectin‐3, influences the susceptibility of galectin‐3 to cleavage by matrix metalloproteinases and is associated with breast cancer incidence. Because forced expression of galectin‐3 in a galectin‐3 null breast cancer cell line confers sensitivity to tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL), the authors sought to determine whether the His64/Pro64 polymorphism of galectin‐3 affects the sensitivity to TRAIL.

METHODS:

Genomic DNA of breast cell lines was analyzed for the single nucleotide polymorphism rs4644, and cytotoxicity was determined with the MTT assay.

RESULTS:

When a collection of 9 breast cancer cell lines that express galectin‐3 was examined for lectin, galactoside‐binding, soluble, 3 (LGALS3) genotype and sensitivity to doxorubicin and TRAIL, doxorubicin sensitivity was not found to be related to LGALS3 genotype. In contrast, none of the 5 cell lines that were homozygous for Pro64 galectin‐3 were found to be sensitive to TRAIL, but 2 of 2 homozygous His64 cell lines and 1 of 2 heterozygous His64 cell lines were sensitive to TRAIL. Forced expression of galectin‐3 of defined genotype in galectin‐3 null cells was used to more directly test the effect of the Pro64His mutation on TRAIL sensitivity. High levels of expression of His64 galectin‐3 rendered BT549 cells sensitive to TRAIL and resistant to doxorubicin, but cells expressing Pro64 galectin‐3 remained resistant to TRAIL and sensitive to doxorubicin.

CONCLUSIONS:

The results of the current study indicate that the naturally occurring Pro64His mutation in galectin‐3 increases sensitivity to death receptor‐mediated apoptosis. This finding could be relevant to disparities in breast cancer outcomes across population groups, and could guide the design of future clinical trials of TRAIL‐based therapies. Cancer 2011;. © 2011 American Cancer Society.
The Rotational Spectrum of Diethyl Ketone
Authors: Nguyen Ha Vinh Lam , Stahl Wolfgang
Published: March 2011

We report on the rotational spectrum of diethyl ketone, C2H5‐C(O)‐C2H5, as observed by Fourier transform microwave spectroscopy under pulsed molecular beam conditions. Almost all lines were split into narrow quartets in a range from 10 kHz up to 2 MHz, arising from the hindered rotation of the two equivalent terminal methyl groups. In a global analysis using the xiam code, which is based on the rho axis method, three rotational constants, five quartic centrifugal distortion constants, the torsional barrier of the terminal methyl groups, and the angles between the principal inertial axes and the internal rotor axes were determined. The methyl torsional barrier was found to be 771.93(27) cm−1. In total, 199 lines were fitted to a standard deviation of 3.5 kHz. The experimental work was supplemented by quantum chemical calculations. Two‐dimensional potential energy surfaces describing the rotation of both ethyl groups against the CO frame were calculated with the MP2 method as well as the DFT method using the 6‐311++G(d,p) basis set and the B3LYP functional, respectively. Combining the experimental and theoretical results, an effective structure with C2v symmetry was deduced for the diethyl ketone molecule. Moreover, the torsional barrier of the methyl groups was determined by ab initio methods.
Understanding the Influence of Guest–Host Interactions on the Conformation of Short Peptides in a Hydrophobic Cavity: A Computational Study
Authors: Hua Weijie , Xu Lina , Luo Yi , Li Shuhua
Published: March 2011

We performed a computational investigation to understand the conformational preferences of four short peptides in a self‐assembled cage based on the experimental work by Y. Hatakeyama et al. (Angew. Chem. Int. Ed. 2009, 48, 8695). For this purpose, we combined molecular dynamics simulations, Monte Carlo simulations, and quantum mechanical calculations to obtain energies and structures for several low‐lying conformers of four peptides and the corresponding peptide‐cage inclusion complexes. Our calculations at both B3LYP and MP2 levels show that for each peptide, the corresponding conformation within the host (as revealed by the crystal structure) does not represent the lowest‐energy conformation of this peptide in vacuum. By comparing some low‐lying conformers in vacuum and in the cavity (for the same peptide), we found that the cage has a significant influence on the conformational propensities of peptides. First, one carbonyl oxygen of each peptide tends to bind to one Zn (II) atom of the cage, forming a ZnO bond. The formation of this bond leads to significant charge transfer from the cage to the peptide. Second, this ZnO bond causes the peptide to go through some local conformational changes. For larger peptides, such as penta‐ and hexapeptides, our calculations also show that some of their conformers must undergo significant structural changes, due to the confinement of the host. This computational study reveals the noticeable influence of the guest–host interaction on the conformational preferences of short peptides.
The spatio‐temporal expression of ProSAP/shank family members and their interaction partner LAPSER1 during Xenopus laevis development
Authors: Gessert Susanne , Schmeisser Michael J. , Tao Si , Boeckers Tobias M. , Kühl Michael
Published: March 2011

Members of the ProSAP/Shank family are important scaffolding proteins of the postsynaptic density (PSD). We investigated for the first time the expression of the three family members named Shank1, ProSAP1/Shank2, and ProSAP2/Shank3 during Xenopus laevis development. Shank1 is expressed in the neural tube, the retina, and the cranial ganglions. In contrast, ProSAP1/Shank2 transcripts could be visualized in the otic vesicle, the pronephros, the liver, the neural tube, and the retina. ProSAP2/Shank3 could be detected in the cardiovascular network, the neural tube, the pronephros, and the retina. Furthermore, we showed that LAPSER1 interacts with all three ProSAP/Shank family members in Xenopus embryos and co‐localizes with ProSAP/Shank in a cell‐based assay. In Xenopus, LAPSER1 is expressed in somites, brain, proctodeum, pronephros, and in some cranial ganglions. Thus, we suggest that members of the ProSAP/Shank family and LAPSER1 not only play a role in PSD formation and plasticity, but also during embryonic development. Developmental Dynamics 240:1528–1536, 2011. © 2011 Wiley‐Liss, Inc.
Hydrogeomorphic processes and vegetation: disturbance, process histories, dependencies and interactions
Authors: Stoffel Markus , Wilford David J.
Published: March 2011

Riparian vegetation and hydrogeomorphic processes are intimately connected parts of upland catchment and fan environments. Trees, shrubs and grasses and hydrogeomorphic processes interact and depend on each other in complex ways on the hillslopes, channels and cone‐shaped fans of torrential watersheds. While the presence and density of vegetation have a profound influence on hydrogeomorphic processes, the occurrence of the latter will also exert control on the presence, vitality, species, and age distribution of vegetation. This contribution aims at providing a review of foundational and more recent work on the dependencies and interactions between hydrogeomorphic processes and vegetation. In particular, we address the role of vegetation in the initiation of hydrogeomorphic processes and its impact on stream morphology as well as immediate and long‐term effects of hydrogeomorphic disturbance on vegetation. Copyright © 2011 John Wiley & Sons, Ltd.
Olig1 is expressed in human oligodendrocytes during maturation and regeneration
Authors: Othman Ahmad , Frim David M. , Polak Paul , Vujicic Snezana , Arnason Barry G. W. , Boullerne Anne I.
Published: March 2011

Myelin repair is inhibited in multiple sclerosis (MS), ultimately leading to axonal damage and disability. We aimed to understand the transcriptional mechanisms of regeneration in primary human oligodendrocyte cultures isolated from white matter of medically intractable epilepsy patients. Cultures at isolation contained 84% mature oligodendrocytes and 16% oligodendrocyte progenitor cells (OPC). The two populations showed a protracted regeneration of membranes expressing myelin proteins after 2–3 weeks in culture, and were kept long‐term to study membranes maintenance. We profiled by quantitative PCR (qPCR) the sequential mRNA expression of transcription factors Olig1, Olig2, Nkx2.2, Sox10, PPARδ, PPARγ, cyclic nucleotide phosphodiesterase (CNP), myelin basic protein (MBP), myelin‐associated glycoprotein (MAG) and myelin oligodendrocyte glycoprotein (MOG). In summary, Olig1 was not expressed in freshly isolated oligodendrocytes, but was expressed from the beginning of process extension until membranes maintenance. In contrast, Olig2 expression was restricted to isolation and during membranes production. We show for the first time PPARδ expression and absence of PPARγ in human oligodendrocytes. Nkx2.2, Sox10, PPARδ, CNP, MBP and MOG messengers were expressed at any time, while MAG messenger was expressed at mature stage only. Myelin proteins CNP, MBP, MAG, and MOG were confirmed by immunocytochemistry. Our findings point to different roles of Olig1 and Olig2 in regeneration of cultured adult human oligodendrocytes. Noticeably, the transcriptional profiles found in cultured neonatal rodent OPC are different. More studies are necessary to elucidate myelin repair in the adult human brain. © 2011 Wiley‐Liss, Inc.