bluuebunny/crossref_metadata_2025 huggingface dataset:
Similarity and stability analysis of the two partitioning type clustering algorithms
Authors: Can Fazli , Ozkarahan Esen A.
Published: May 2013

The similarity and stability analysis of the two partitioning type clustering algorithms, which appeared in this journal recently, are presented with respect to two different metrics. This article also includes other aspects of the algorithms, such as the number and size of the clusters generated, the similarity between the members of a cluster and the corresponding centroid, and other relevant details. In the experiments, a document collection consisting of the titles, abstracts, and keywords of 167 ACM TODS publications was used.
Homocysteine causes disruptions in spinal cord morphology and changes the expression of Pax 1/9 and Sox 9 gene products in the axial mesenchyme
Authors: Kobus Karoline , Ammar Dib , Nazari Evelise Maria , Rauh Müller Yara Maria
Published: May 2013

BACKROUND

Neural tube defects (NTD) involve disruptions in the axial mesenchyme, and are related to an imbalance between folic acid (FA) and homocysteine (Hcy). This study evaluated the effects of FA/Hcy imbalance on cell proliferation and expression of the Pax 1/9 and Sox 9 gene products in the axial mesenchyme of chickens.

METHODS

Embryos were incubated (38°C) and pretreated at 24 h and treated at 46 h of incubation. The experimental groups were: FA‐pretreated with saline and treated with 0.5 μg FA/saline; Hcy‐pretreated with 50 μl saline and treated with 20 μmol D,L‐Hcy/50 μl saline; FA+Hcy‐pretreated with 0.5 μg FA/50 μl saline and treated with 20 μmol D,L‐Hcy/50 μl saline; and the control embryos were pretreated and treated with saline. Embryos were analyzed at E4 and E6. Immunohistochemistry was performed to identify proliferating cells and the expression of the gene products of Pax 1/9 and Sox 9. Total RNA of the E4 embryos was extracted and a RT‐qPCR assay was performed to quantify Pax 1/9 mRNA expression.

RESULTS

Hcy treatment caused spinal NTD and abnormalities in axial mesenchyme development, affecting the distribution of sclerotomal cells and chondrification. Hcy also reduced cell proliferation and changed the expression of Pax 1/9 and Sox 9 in the mesenchyme.

CONCLUSIONS

Our data clarified the relationship between spinal NTD genesis and disruptions of Pax 1/9 and Sox 9 gene products in the axial mesenchyme caused by the FA/Hcy imbalance. Birth Defects Research (Part A) 97:386–397, 2013. © 2013 Wiley Periodicals, Inc.
Prenatal exposure to nitrosatable drugs, vitamin C, and risk of selected birth defects
Authors: Shinde Mayura U. , Vuong Ann M. , Brender Jean D. , Werler Martha M. , Kelley Katherine E. , Huber John C. , Sharkey Joseph R. , Zheng Qi , Suarez Lucina , Langlois Peter H. , Canfield Mark A. , Romitti Paul A. , Malik Sadia ,   The National Birth Defects Prevention Study
Published: May 2013

BACKGROUND

Nitrosatable drugs, such as secondary or tertiary amines and amides react with nitrite in an acidic environment to form N‐nitroso compounds, teratogens in animal models. Vitamin C is a known nitrosation inhibitor.

METHODS

Using data from the National Birth Defects Prevention Study, we assessed nitrosatable drug exposure and vitamin C intake during the first trimester among 11,606 case‐mothers of infants with oral clefts, limb deficiencies (LDs), or congenital heart defects and 6807 control‐mothers of infants without major birth defects during 1997–2005. Daily intake of vitamin C was estimated from maternal interviews that elicited information about supplement use and dietary intake.

RESULTS

With no reported use of nitrosatable drugs as the referent group, a lower odds ratio (OR) was observed for transverse LDs among births to mothers exposed to secondary amine drugs and daily vitamin C supplementation (adjusted odds ratio [aOR] 1.2, 95% confidence interval [CI] 0.83–1.8) compared with women taking these drugs and no supplementation (aOR 2.7, 95% CI 1.5–4.6). The OR for longitudinal LDs associated with secondary amine exposure was lower with daily dietary vitamin C intake ≥85 mg (aOR 1.2, 95% CI 0.68–2.0) compared with <85 mg (aOR 1.9, 95% CI 1.2–3.1). Daily vitamin C supplementation in combination with higher dietary vitamin C intake reduced associations between nitrosatable drug exposures and limb deficiencies and atrial septal defects not otherwise specified.

CONCLUSION

Prenatal dietary and vitamin C supplement intake may diminish the association between nitrosatable drug exposure during pregnancy and selected birth defects. Birth Defects Research (Part A) 97:515‐531, 2013. © 2013 Wiley Periodicals, Inc.
Toward a universal treatment for cancer: cell inflation assisted chemotherapy
Authors: Corcos Daniel
Published: May 2013

Cancers show considerable genetic and functional heterogeneity, preventing the development of a universal anticancer drug. Here, I argue that it is nevertheless possible to elaborate a therapeutic strategy that can be used in almost every cancer, exploiting the negative feedback effect of normal cells on the proliferation of their precursors. This method, termed cell inflation assisted chemotherapy, is aimed at blocking normal cell division prior to high‐dose antimitotic chemotherapy. Evidence for a negative feedback effect on granulocyte production suggests that it is possible to prevent neutropenia by transfusion of autologous granulocytes. In a first step, this protocol will be devised to protect neutrophils and to prevent granulopenia in patients treated with intensive chemotherapy. In its simplest form, it will consist of a leukapheresis–storage–reinjection sequence just prior to drug administration. Then, if the proof of concept is established, a more systematic use of intensive cell cycle‐specific chemotherapy, together with protection of other lineages through temporary mitotic blockade might be a treatment applicable for most cancers.
Reduction in serum clusterin is a potential therapeutic biomarker in patients with castration‐resistant prostate cancer treated with custirsen
Authors: Blumenstein Brent , Saad Fred , Hotte Sebastien , Chi Kim N. , Eigl Bernhard , Gleave Martin , Jacobs Cindy
Published: May 2013

Elevated levels of clusterin (CLU), a stress‐induced and secreted cytoprotective chaperone, are associated with advanced tumor stage, metastasis, treatment resistance, and adverse outcome in several cancers. Custirsen, a second‐generation antisense oligonucleotide, inhibits CLU production in tumor cells and reduces serum CLU levels. A Phase 2 study evaluated custirsen in combination with second‐line chemotherapy in men with metastatic castration‐resistant prostate cancer (mCRPC) who had progressed while on or within 6 months of first‐line docetaxel‐based chemotherapy. Exploratory analyses evaluated serum CLU levels during custirsen treatment and correlative clinical effects on prostate‐specific antigen (PSA) response, overall survival, and any relationship between serum CLU and PSA. Men with mCRPC were treated with mitoxantrone/prednisone/custirsen (MPC, n = 22) or docetaxel retreatment/prednisone/custirsen (DPC plus DPC‐Assigned, n = 45) in an open‐label, multicenter study. Subject‐specific profiles of PSA and serum CLU levels during treatment were characterized using statistical modeling to compute subject‐specific summary measures; these measures were analyzed for relationship to survival using proportional hazard regression. Estimated individual serum CLU response profiles were scored as below or at/above the median level for the population through 100 days postrandomization. Median survival was longer for subjects scoring below the median serum CLU level compared with subjects at/above the median level, respectively (MPC: 15.1 months vs. 6.2 months; DPC‐Pooled: 17.0 months vs. 12.1 months). Lowered serum CLU levels during custirsen treatment when in combination with either chemotherapy regimen were predictive of longer survival in mCRPC. These results support further evaluation of serum CLU as a therapeutic biomarker.
Racial differences in time from prostate cancer diagnosis to treatment initiation
Authors: Stokes William A. , Hendrix Laura H. , Royce Trevor J. , Allen Ian M. , Godley Paul A. , Wang Andrew Z. , Chen Ronald C.
Published: May 2013

BACKGROUND

Timely delivery of care has been identified by the Institute of Medicine as an indicator for quality health care, and treatment delay is a potentially modifiable obstacle that can contribute to the disparities among African American (AA) and Caucasian patients in prostate cancer recurrence and mortality. Using the Surveillance, Epidemiologic and End Results (SEER)‐Medicare linked database, we compared time from diagnosis to treatment in AA and Caucasian prostate cancer patients.

METHODS

A total of 2506 AA and 21,454 Caucasian patients diagnosed with localized prostate cancer from 2004 through 2007 and treated within 12 months were included. Linear regression was used to assess potential differences in time to treatment between AA and Caucasian patients, after adjusting for sociodemographic and clinical covariates.

RESULTS

Time from diagnosis to definitive (prostatectomy and radiation) treatment was longer for AA patients in all risk groups, and most pronounced in high‐risk cancer (96 versus 105 days, P < .001). On multivariate analysis, racial differences to any and definitive treatment persisted (β = 7.3 and 7.6, respectively, for AA patients). Delay to definitive treatment was longer in high‐risk (versus low‐risk) disease and in more recent years.

CONCLUSIONS

AA patients with prostate cancer experienced longer time from diagnosis to treatment than Caucasian patients with prostate cancer. AA patients appear to experience disparities across all aspects of this disease process, and together these factors in receipt of care plausibly contribute to the observed differences in rates of recurrence and mortality among AA and Caucasian patients with prostate cancer. Cancer 2013;119:2486‐2493. © 2013 American Cancer Society.
Gene regulatory evolution and the origin of macroevolutionary novelties: Insights from the neural crest
Authors: Van Otterloo Eric , Cornell Robert A. , Medeiros Daniel Meulemans , Garnett Aaron T.
Published: May 2013

The appearance of novel anatomic structures during evolution is driven by changes to the networks of transcription factors, signaling pathways, and downstream effector genes controlling development. The nature of the changes to these developmental gene regulatory networks (GRNs) is poorly understood. A striking test case is the evolution of the GRN controlling development of the neural crest (NC). NC cells emerge from the neural plate border (NPB) and contribute to multiple adult structures. While all chordates have a NPB, only in vertebrates do NPB cells express all the genes constituting the neural crest GRN (NC‐GRN). Interestingly, invertebrate chordates express orthologs of NC‐GRN components in other tissues, revealing that during vertebrate evolution new regulatory connections emerged between transcription factors primitively expressed in the NPB and genes primitively expressed in other tissues. Such interactions could have evolved by two mechanisms. First, transcription factors primitively expressed in the NPB may have evolved new DNA and/or cofactor binding properties (protein neofunctionalization). Alternately, cis‐regulatory elements driving NPB expression may have evolved near genes primitively expressed in other tissues (cis‐regulatory neofunctionalization). Here we discuss how gene duplication can, in principle, promote either form of neofunctionalization. We review recent published examples of interspecies gene‐swap, or regulatory‐element‐swap, experiments that test both models. Such experiments have yielded little evidence to support the importance of protein neofunctionalization in the emergence of the NC‐GRN, but do support the importance of novel cis‐regulatory elements in this process. The NC‐GRN is an excellent model for the study of gene regulatory and macroevolutionary innovation. genesis 51:457–470. © 2013 Wiley Periodicals, Inc.
A more sustainable Wohl–Ziegler bromination: Versatile derivatization of unsaturated FAMEs and synthesis of renewable polyamides
Authors: Winkler Matthias , Steinbiß Michael , Meier Michael A. R.
Published: May 2013

Within this contribution, a more sustainable procedure for the Wohl–Ziegler bromination of unsaturated fatty acid methyl esters (FAME) was investigated. The resulting allylic bromide functional FAMEs were used for elimination reactions to prepare conjugated fatty acids. Moreover, the fatty acid derived allylic bromides were used as initiators for atom transfer radical polymerization (ATRP). Furthermore, the synthesis of AB‐type polyamide monomers was accomplished by a complementary hydrobromination of FAME and subsequent modification. The obtained polyamides were characterized by GPC, NMR, and DSC analysis.
Chip electrophoresis of gelatin‐based nanoparticles
Authors: Weiss Victor U. , Lehner Angela , Grombe Ringo , Marchetti‐Deschmann Martina , Allmaier Günter
Published: May 2013

Recently, biodegradable nanoparticles received increasing attention for pharmaceutical applications as well as applications in the food industry. With the current investigation we demonstrate chip electrophoresis of fluorescently (FL) labeled gelatin nanoparticles (gelatin NPs) on a commercially available instrument. FL labeling included a step for the removal of low molecular mass material (especially excess dye molecules). Nevertheless, for the investigated gelatin NP preparation two analyte peaks, one very homogeneous with an electrophoretic net mobility of μ = −24.6 ± 0.3 × 10−9 m2/Vs at the peak apex (n = 17) and another more heterogeneous peak with μ between approximately −27.2 ± 0.2 × 10−9 m2/Vs and −36.6 ± 0.2 × 10−9 m2/Vs at the peak beginning and end point (n = 11, respectively) were recorded. Filtration allowed enrichment of particles in the size range of approximately 35 nm (pore size employed for concentration of gelatin NPs) to 200 nm (pore size employed during FL labeling). This corresponded to the very homogeneous peak linking it to gelatin NPs, whereas the more heterogeneous peak probably corresponds to gelatin not cross‐linked to such a high degree (NP building blocks). Several further gelatin NP preparations were analyzed according to the same protocol yielding peaks with electrophoretic net mobilities between −23.3 ± 0.3 × 10−9 m2/Vs and −28.9 ± 0.2 × 10−9 m2/Vs at peak apexes (n = 15 and 6). Chip electrophoresis allows analyte separation in less than two minutes (including electrophoretic sample injection). Together with the high sensitivity of the FL detection – the LOD as derived for the first main peak of the applied dye from the threefold standard deviation of the background noise values 80 pM for determined separation conditions – this leads to a very promising high throughput separation technique especially for the analysis of bionanoparticles. For gelatin NP preparations, chip electrophoresis allows for example the comparison of preparation batches concerning the amount of NPs and gelatin building blocks as well as the indirect assessment of the degree of gelatin cross‐linking (from obtained FL signals).
Evaluation of the slip length in the slipping friction between background electrolytes and peptides through the modeling of their capillary zone electrophoretic mobilities
Authors: Deiber Julio A. , Piaggio Maria V. , Peirotti Marta B.
Published: May 2013

This work analyzes and discusses several physicochemical peptide chain properties that may generate partial or total BGE slip boundary conditions on the surface of peptides migrating as spherical and aspherical particles in CZE. A definition of the BGE slip length is presented that is able to account the effect of particle curvature through the associated metrical coefficients. This definition allows the distinction between partial and total BGE slip lengths. It is also shown that the BGE slip length must be variable on orthotropic aspherical particles surfaces.
A new approach to the studies of submicron particle suspensions based on the effect of pressure in capillary zone electrophoresis
Authors: Vanifatova Nataliya , Rudnev Alexander , Spivakov Boris
Published: May 2013

A new approach based on the effect of pressure in CZE is suggested for acceleration of particle migration in electrophoretic runs resulting in reduction of the analysis time. It provides conditions for studying fast processes in suspensions. The effect of pressure on the migration of silica spheres with average diameters of 100, 150, and 390 nm was studied by CZE at an applied voltage of 25 kV. The particle hydrodynamic behavior was also investigated under the same capillary dimensions and BGE composition. The total particle mobility (excluding the average flow rate) was found to increase with increasing the pressure applied and particle size. The particle migration mechanism explaining the effect of pressure on particle velocity was shown to be almost the same as in wide‐bore hydrodynamic chromatography. It is based on changing radial distribution of particle concentration along the capillary cross section depending on particle diffusivity. On the basis of this mechanism appearance of a zone of negatively charged particles in electropherograms ahead of the marker peak can be explained.
A fast and low‐cost spray method for prototyping and depositing surface‐enhanced Raman scattering arrays on microfluidic paper based device
Authors: Li Bowei , Zhang Wei , Chen Lingxin , Lin Bingcheng
Published: May 2013

In this study, a fast, low‐cost, and facile spray method was proposed. This method deposits highly sensitive surface‐enhanced Raman scattering (SERS) silver nanoparticles (AgNPs) on the paper‐microfluidic scheme. The procedures for substrate preparation were studied including different strategies to synthesize AgNPs and the optimization of spray cycles. In addition, the morphologies of the different kinds of paper substrates were characterized by SEM and investigated by their SERS signals. The established method was found to be favorable for obtaining good sensitivity and reproducible results. The RSDs of Raman intensity of randomly analyzing 20 spots on the same paper or different filter papers depositing AgNPs are both below 15%. The SERS enhancement factor is approximately 2 × 107. The whole fabrication is very rapid, robust, and does not require specific instruments. Furthermore, the total cost for 1000 pieces of chip is less than $20. These advantages demonstrated the potential for growing SERS applications in the area of environmental monitoring, food safety, and bioanalysis in the future.
Micro reaction technology for valorization of biomolecules using enzymes and metal catalysts
Authors: Denčić Ivana , Noël Timothy , Meuldijk Jan , de Croon Mart , Hessel Volker
Published: May 2013

The methodology of processing biomass for the production of fuels and chemicals has been well established; however, these processes are often not economical due to the high cost of materials and low selectivity. In order to more efficiently use the raw materials, and to decrease processing (and developing) time, it is necessary to consider novel synthesis routes and/or novel process technologies for biomass valorization. The use of micro‐/millireactor technology for this purpose is still under investigation. This review introduces relevant processes for the conversion of biomolecules into the industrially valuable products developed (or under development) in a microreactor. The processes with the enzyme‐ and metal‐based catalysts are considered and carbohydrates, amino acids, and their derivatives as starting materials for processing in microreactors are reviewed as well. Also, we discuss main motivations, achievements, and current challenges when using microreactor technology, and the status of a holistic process design approach in relevant fields. We suggest that although there are individual examples reported on sustainable process design including microreactor technology, the systematic approach is still missing.
Investigation of color removal from methylene blue containing solutions by electrocoagulation/flotation in a batch‐agitated electrochemical reactor
Authors: Mohammed Ghadir R. , Zewail Taghreed M. , El‐Tawail Yahia A.
Published: May 2013

The performance of a batch‐agitated cell for the electrocoagulation/flotation (ECF) of methylene blue (MB) has been investigated. The batch‐agitated cell consisted of 45° pitched iron paddle anode and a horizontal iron disc cathode which was fixed at the bottom of the vessel. The performance of the present batch‐agitated cell was optimized with respect to percentage color removal and power consumption. Optimum operational parameters were electrolysis time = 12 min, current density = 17.36 mA/cm2, NaCl conc = 4 g/L, pH = 7, and rpm = 74. A 92.5% color removal of the dye was achieved at the optimum conditions and 10.9 kW.hr were consumed for 1 kg dye removed. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 369–377, 2014
The costimulatory molecule CD70 is regulated by distinct molecular mechanisms and is associated with overall survival in diffuse large B‐cell lymphoma
Authors: Bertrand P. , Maingonnat C. , Penther D. , Guney S. , Ruminy P. , Picquenot J. M. , Mareschal S. , Alcantara M. , Bouzelfen A. , Dubois S. , Figeac M. , Bastard C. , Tilly H. , Jardin F.
Published: May 2013

In diffuse large B‐cell lymphomas (DLBCL), a recurrent deletion of the 19p13 region has recently been described.CD70andTNFSF9genes are suspected tumor suppressor genes, but previous studies suggest an oncogenic role forCD70. Therefore, we studied the consequences of variation inCD70copy number and epigenetic modifications onCD70expression. Copy‐number variation was investigated in 144de novoDLBCL tissues by comparative genomic hybridization array and quantitative multiplex PCR. Gene expression was assessed by quantitative RT‐PCR, andCD70promoter methylation was determined by pyrosequencing. The 19p13.3.2 region was deleted in 21 (14.6%) cases, which allowed the minimal commonly deleted region of 57 Kb that exclusively includes theCD70gene to be defined. Homozygous deletions were observed in four (2.7%) cases, and acquired single‐nucleotide variations ofCD70were detected in nine (6.3%) cases.CD70was highly expressed in both germinal centre B‐cell‐like (GCB) and activated B‐cell‐like (ABC) DLBCL compared to normal tissue, with distinct molecular mechanisms of mRNA expression regulation. A gene dosage effect was observed in the GCB subtype, whereas promoter methylation was the predominant mechanism of down regulation in the ABC subtype. However, highCD70expression levels correlated to shorter overall survival in both the GCB (P= 0.0021) and the ABC (P=0.0158) subtypes. In conclusion,CD70is targeted by recurrent deletions, somatic mutations and promoter hypermethylation, but its high level of expression is related to an unfavorable outcome, indicating that this molecule may constitute a potential therapeutic target in selected DLBCL. © 2013 Wiley Periodicals, Inc.
Genome‐wide identification of genes with amplification and/or fusion in small cell lung cancer
Authors: Iwakawa Reika , Takenaka Masataka , Kohno Takashi , Shimada Yoko , Totoki Yasushi , Shibata Tatsuhiro , Tsuta Koji , Nishikawa Ryo , Noguchi Masayuki , Sato‐Otsubo Aiko , Ogawa Seishi , Yokota Jun
Published: May 2013

To obtain a landscape of gross genetic alterations in small cell lung cancer (SCLC), genome‐wide copy number analysis and whole‐transcriptome sequencing were performed in 58 and 42 SCLCs, respectively. Focal amplification of known oncogene loci, MYCL1 (1p34.2), MYCN (2p24.3), and MYC (8q24.21), was frequently and mutually exclusively detected. MYCL1 and MYC were co‐amplified with other regions on either the same or the different chromosome in several cases. In addition, the 9p24.1 region was identified as being amplified in SCLCs without amplification of MYC family oncogenes. Notably, expression of the KIAA1432 gene in this region was significantly higher in KIAA1432 amplified cells than in non‐amplified cells, and its mRNA expression showed strong correlations with the copy numbers. Thus, KIAA1432 is a novel gene activated by amplification in SCLCs. By whole‐transcriptome sequencing, a total of 60 fusion transcripts, transcribed from 95 different genes, were identified as being expressed in SCLC cells. However, no in‐frame fusion transcripts were recurrently detected in ≥2 SCLCs, and genes in the amplified regions, such as PVT1 neighboring MYC and RLF in MYCL1 amplicons, were recurrently fused with genes in the same amplicons or with those in different amplicons on either the same or different chromosome. Thus, it was indicated that amplification and fusion of several genes on chromosomes 1 and 8 occur simultaneously but not sequentially through chromothripsis in the development of SCLC, and amplification rather than fusion of genes plays an important role in its development. © 2013 The Authors Genes, Chromosomes & Cancer Published by Wiley Periodicals, Inc.
Extreme densities in Titan's ionosphere during the T85 magnetosheath encounter
Authors: T. Edberg N. J. , Andrews D. J. , Shebanits O. , Ågren K. , Wahlund J.‐E. , Opgenoorth H. J. , Roussos E. , Garnier P. , Cravens T. E. , Badman S. V. , Modolo R. , Bertucci C. , Dougherty M. K.
Published: May 2013

We present Cassini Langmuir probe measurements of the highest electron number densities ever reported from the ionosphere of Titan. The measured density reached 4310 cm−3 during the T85 Titan flyby. This is at least 500 cm−3 higher than ever observed before and at least 50% above the average density for similar solar zenith angles. The peak of the ionospheric density is not reached on this flyby, making the maximum measured density a lower limit. During this flyby, we also report that an impacting coronal mass ejection (CME) leaves Titan in the magnetosheath of Saturn, where it is exposed to shocked solar wind plasma for at least 2 h 45 min. We suggest that the solar wind plasma in the magnetosheath during the CME conditions significantly modifies Titan's ionosphere by an addition of particle impact ionization by precipitating protons.
Potential seasonal predictability: Comparison between empirical and dynamical model estimates
Authors: DelSole Timothy , Kumar Arun , Jha Bhaskar
Published: May 2013

Methods for estimating potential seasonal predictability from a single realization of daily data are validated against an ensemble of simulations from an atmospheric model driven by observed sea surface temperature, sea ice extent, and greenhouse gas concentration. The methods give surprisingly good estimates of potential predictability of seasonal precipitation despite the fact that the methods assume Gaussian distributions. For temperature, the methods systematically underestimate weather noise variance over land, often by a factor of 2 or more. This bias can be reduced by taking account of precipitation‐induced variability. These conclusions may be model dependent, and hence, confirmation in other models would be of interest. Nevertheless, for the state‐of‐the‐art atmospheric model used in this study, the results strongly support the validity of the single time series approach to estimating potential predictability and enhances our confidence in previous estimates of potential predictability based on observations alone.
Field measurements and scaling of ocean surface wave‐breaking statistics
Authors: Sutherland Peter , Melville W. Kendall
Published: May 2013

Deep‐water breaking waves provide a mechanism for mass, momentum, and energy transfer between the atmosphere and ocean. Microscale breaking is particularly important, but notoriously difficult to measure in the field. In this paper, measurements from a new technique, using a stereo pair of long‐wave infrared cameras to reconstruct the sea surface shape and velocity field, are presented. Breakers are detected using an image texture‐based algorithm and then tracked on the reconstructed surface. These waves range from large air‐entraining breakers to microbreakers that are undetectable by traditional visible video‐based techniques. This allows measurements of breaker length distributions, Λ(c), that extend to velocities near the gravity‐capillary transition. These distributions are compared with measurements from the literature and from visible video imagery. A nondimensional scaling is proposed which collapses Λ(c). Finally, estimates of energy dissipation and stress based on Λ(c) are found to agree well with wave energy dissipation and wind stress models.
The response of the large‐scale ocean circulation to 20th century Asian and non‐Asian aerosols
Authors: Cowan T. , Cai W.
Published: May 2013

Multidecadal trends in the large‐scale ocean circulation are influenced by changes in radiative forcings such as long‐lived greenhouse gases, volcanic aerosols, and solar irradiance. Model simulations suggest that anthropogenic aerosols can also force circulation changes, including delaying the weakening of the North Atlantic thermohaline circulation, altering the interhemispheric sea surface temperature gradient, and inducing a pan‐oceanic heat redistribution. The extent to which aerosols from different regions contribute to these oceanic changes is currently unknown. Using specifically designed 20th century coupled climate model experiments that separate Asian and non‐Asian aerosol impacts, it is shown that the non‐Asian aerosol component, predominantly sulfate aerosols, accounts for much of the simulated aerosol‐induced oceanic changes. These include delaying the weakening of the global meridional circulation, increasing the northward heat transport across the equatorial Atlantic, and inducing a subsurface cooling in the subtropical southern Indian Ocean. As global sulfate aerosol levels peaked in the 1980s, these trends may be starting to reverse. This study highlights the importance of Northern Hemisphere non‐Asian anthropogenic aerosols in driving remote changes in Southern Hemisphere subtropical and extratropical oceans.
Mechanistic insights into the nongenomic regulation of phospholipid synthesizing enzymes
Authors: Cardozo Gizzi Andrés M. , Caputto Beatriz L.
Published: May 2013

Lipid synthesis is a complex process regulated at multiple levels. Here, we will discuss nongenomic regulatory mechanisms, particularly the activation and/or recruitment of key enzymes to membranes. The phospholipid synthesis enzymes Lipin and CTP:phosphocholine cytidylyltransferase are taken as examples of these mechanisms that are mediated by posttranslational modifications or by an intrinsic property of the enzyme that senses lipid composition. In addition, special emphasis will be put on another relevant non genomic lipid synthesis regulation mechanism that is dependent on c‐Fos, a protein that has deserved less attention so far. This latter regulatory mechanism is emerging as an important determinant for processes that require high rates of lipid synthesis such as those of growth and proliferation. © 2013 IUBMB Life, 65(7):584–592, 2013.
Hemodynamic assessment of indomethacin‐induced fetal heart failure in high‐output state
Authors: Tongsong Theera , Luewan Suchaya , Srisupundit Kasemsri , Jatavan Thanate
Published: May 2013

Hemodynamic study was performed on a 32‐year‐old woman presenting at 27 weeks' gestation. Ultrasound revealed a single normal fetus with mild cardiomegaly, polyhydramnios, and placental chorioangioma. Doppler study showed increased middle cerebral artery peak systolic velocity, normal Tei index, and forward flow of “a” wave with normal preload in the ductus venosus. Twelve hours after initiation of indomethacin for tocolysis, frank hydrops fetalis developed rapidly. The right ventricle showed poor contractility and performance. Markedly increased preload in ductus venosus with reversed “a” wave and pulsations in the umbilical vein were demonstrated. This study suggests that indomepacin treatment in fetal high‐cardiac output state should be used with extreme caution. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 41:438–440, 2013
A statistical study on ELF‐whistlers/emissions and M ≥ 5.0 earthquakes in Taiwan
Authors: Liu J. Y. , Wang K. , Chen C. H. , Yang W. H. , Yen Y. H. , Chen Y. I. , Hatorri K. , Su H. T. , Hsu R. R. , Chang C. H.
Published: May 2013

In this paper, we conduct statistical approaches to study the potential relation between ELF‐whistlers/emissions below 100 Hz and 20 M ≥ 5.0 earthquakes occurred in Taiwan in the period from 26 August 2003 to 13 July 2004. Occurrence ratios of the ELF‐whistler and ELF‐emission of the entire study period are computed as the reference backgrounds. Our study shows that the ELF‐whistlers and ELF‐emissions during the earthquake period appear less and more frequently than their associated backgrounds, respectively. For the ELF‐emission, the larger earthquakes generally yield the higher occurrence ratios. The statistical analyses confirm that the occurrence ratios of the ELF‐emission significantly enhance 5–7 days before the earthquakes and are proportional to the earthquake magnitude but inversely to the distance from the observatory to the epicenter.
Evaluation of stationary phases based on silica hydride for the analysis of drugs of abuse
Authors: Pesek Joseph J. , Matyska Maria T. , Kim Amy M.
Published: May 2013

Several stationary phases based on silica hydride were evaluated as possible separation media for drugs of abuse. In the RP mode both a C18 and a phenyl column were tested using ACN/water and methanol/water mobile phases with formic acid or ammonium formate as modifiers. Detection was performed using MS, so separation of isobaric species was a factor in selecting the column, mobile phase composition, and gradient. A number of sample preparation procedures were also included as part of determining the most appropriate experimental protocol on these types of stationary phases. Morphine was used as a model for developing a protocol that would be suitable for the analysis of hydrophilic drugs.
Chiral pH‐Responsive Amphiphilic Polymer Co‐networks: Preparation, Chiral Recognition, and Release Abilities
Authors: Shi Lu , Xie Peng , Li Zhimin , Wu Youping , Deng Jianping
Published: May 2013

Novel amphiphilic polymer co‐networks (APCNs), poly(N‐acryloyl‐L‐alanine)‐l‐polydimethylsiloxane (denoted as PNAA‐l‐PDMS), are prepared, and exhibit remarkable pH‐responsiveness, chiral‐recognition, and enantioselective‐release abilities. The APCNs are prepared by free‐radical copolymerization starting from N‐acryloyl‐L‐alanine (NAA) and methacrylate‐terminated poly(dimethylsiloxane) (M‐PDMS) as co‐(macro)monomers. The APCNs show pronounced pH‐sensitivity, evidenced by a reversible swelling–deswelling transition upon a cyclicly altering pH. The chiral co‐networks are applied for enantioselective recognition and release. A maximum adsorption is achieved towards D‐proline (61%), whereas for L‐proline, it is only 10%. More interestingly, the release for the L‐proline is 90%, whereas for the D‐proline, only 70% is released.

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A New Method for the Analysis of the Substitution Pattern of Hydroxyethyl(methyl)‐Celluloses Along the Polysaccharide Chain
Authors: Mischnick Petra , Unterieser Inga , Voiges Kristin , Cuers Julia , Rinken Marian , Adden Roland
Published: May 2013

Hydroxyethylmethyl celluloses (MSHE 0.15–0.26, DSMe 1.49–1.82) and hydroxyethyl celluloses (MSHE 1.89–3.03) are analyzed with respect to their substituent distribution in the polymer chains. The cellulose ethers are peralkylated and partially hydrolyzed, and are analyzed by electrospray ionization‐ion trap‐mass spectrometry (ESI‐IT‐MS). The randomness of the partial hydrolysis is proven. Quantitative evaluation of their mass spectra becomes possible after labeling the oligosaccharides at the reducing end. Reductive amination with o‐aminobenzoic acid gives better results than hydrazone formation with cationic Girard's T reagent. Syringe pump infusion gives more‐accurate results compared with liquid chromatography (LC)‐ESI‐MS. Profiles of the substituent distribution in the oligosaccharide fractions of DP 2–DP 7 are compared with the theoretical random distribution of glucosyl units in the chain.

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Tsirelson like operator spaces
Authors: Lee Hun Hee
Published: May 2013

We construct nontrivial examples of weak‐ operator spaces with the local operator space structure very close to . These examples are non‐homogeneous Hilbertian operator spaces, and their constructions are similar to that of 2‐convexified Tsirelson's space by W. B. Johnson.
A Compact Broadband Balun on Multilayer Organic Substrate
Authors: Ta Hai Hoang , Pham Anh Vu
Published: May 2013

We present the design and development of a compact, broadband balun based on a quasi‐lumped LC transformer. The balun is constructed on a multilayer liquid crystal polymer substrate. The balun has a wide range of operating frequency from 0.9 to 3.6 GHz. Within this operating band, the balun achieves a measured insertion loss of less than 1 dB, a measured return loss of better than 10 dB, a measured amplitude imbalance of less than 1 dB and a measured phase imbalance less than 7°. This balun has an extremely compact size of 2 × 2.5 mm2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1957–1959, 2013
Locally Implicit Discontinuous Galerkin Finite Element Method for Transient Analysis of 3D Layered Structures with Electrically Small Details
Authors: Chen, Jiefu , Tobon, Luis , Huo Liu Qing
Published: May 2013

An efficient locally implicit discontinuous Galerkin finite element method is proposed for time domain analysis of 3D layered problems. The vector mixed finite elements with discontinuous Galerkin method are employed for spatial discretization, and the singly diagonally implicit Runge–Kutta scheme is used for time stepping. The block Thomas algorithm is utilized during time integration to eliminate the subdomain‐based iteration. Numerical examples demonstrate the proposed method is efficient in simulating 3D layered structures containing electrically small components. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1912–1916, 2013
Changing the Electromagnetic Bandgap and Stopbands in a Multistate Periodic Circuit
Authors: Thalakotuna, Dushmantha N. P. , Esselle Karu P. , Matekovits, Ladislau , Heimlich Michael , Hay Stuart G.
Published: May 2013

Changing the electromagnetic bandgaps (EBGs) and hence the stopbands in a multistate periodic microwave circuit is investigated experimentally. The state of the prototype circuit, consisting of 24 unit cells, is changed by closing or opening gaps in selected unit cells. This varies the periodic loading along the circuit and hence the EBG. In most states, the circuit behaves as a bandstop filter, and its stopband width and location are determined by the circuit state. Experimental results confirm that the first stopband width can be as large as 63% (at 4.92 GHz) or can be absent. The EBG leads to excellent isolation around 40 dB in the stopbands. Sharp roll‐off between passbands and stopbands (upto 120 dB/octave) and small length compared to microstrip filters with similar cut‐off and roll‐off characteristics are other advantages of the proposed platform. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1871–1874, 2013
A Low Cost 8 × 8 W‐Band Substrate Integrated Waveguide Antenna Array Detector on LCP
Authors: Samuel Chieh, Jia‐Chi , Pham Anh‐Vu , Pidwerbetsky, Alex , Kannell George
Published: May 2013

The design and fabrication of a W‐band 64 element slot antenna array based on the substrate integrated waveguide structure is presented in this communication. The prototype antenna array is fabricated on a liquid crystal polymer substrate using standard printed circuit board (PCB) manufacturing processes. Characterization of the unbalanced antenna is accomplished through the use of a millimeter‐wave diode detector circuit, which is integrated onto the antenna array. Measurements show a beamwidth of approximately 13.2°. The maximum sensitivity of the antenna array with the diode detector is 121 mV/mW at 96 GHz. The total size of the antenna array with detector circuit is 4 × 3 cm2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1825–1830, 2013
Frequency‐Tunable Monopole Antenna for Wimax Applications
Authors: Sun X. L. , Cheung S. W. , Yuk T. I.
Published: May 2013

This article presents a planar dual‐band monopole antenna with a frequency‐tunable band for use in wireless devices of the 2.4 and 3.4 GHz worldwide interoperability for microwave access (WiMAX) system. The antenna has two radiating branches acting as monopoles and resonating at around 2.4 GHz (lower band) and 3.4 GHz (higher band). A varactor is placed on the radiating branch responsible for the lower band. A very simple DC biasing circuit is designed for reverse‐biasing the varactor. By varying the DC‐bias voltages from 0 to 12 V for the varactor, the lower band of the antenna can be continuously tuned from 2.3 to 2.83 GHz, covering the frequency bands from 2.3 to 2.4 GHz and 2.5 to 2.7 GHz for the WiMAX system. The antenna has a small overall size of 40 × 35 × 0.8 mm3 with a compact radiator of only 14.5 × 8.2 mm2. The antenna performance in terms of reflection coefficient, radiation pattern, peak gain, and efficiency is studied using computer simulation. For verification of simulation results, the antenna is fabricated and measured. The feeding cable used in measurement causes substantial discrepancies between the simulated and measured simulation results. To study the cable effects, a computer simulation model is included for studies. With the cable model, the simulated and measured results agree very well. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1902–1907, 2013
Wide‐Beam UWB Antenna with A Couch‐Like Reflector for use in an Indoor Home Security Service
Authors: Moon Junyoung , Ha Jaegeun , Choi Jaehoon
Published: May 2013

An impulse radar‐UWB antenna for home security service application is proposed. The antenna consists of a partially elliptical monopole and a couch‐like reflector. The couch‐like reflector creates an antenna beam wide enough to be used for home security service applications. In addition, the antenna can be inconspicuously installed in the upper corner of a room. The dimension of the proposed antenna is 21 × 38 × 20 mm3. The measured H‐plane beam width is wider than 130° over the 10 dB return loss bandwidth of the antenna (6.7–10.33 GHz). The peak gain is greater than 4 dBi in the frequency band of interest. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1721–1724, 2013
A Miniaturized Branch‐Line Coupler Using Triangular Patch Type Artificial Transmission Line
Authors: Oh Song‐Yi , Hwang Hee‐Yong
Published: May 2013

A branch‐line coupler using microstrip artificial transmission lines (ATLs) with slotted triangular patches is proposed. For the ATL, a five‐section stepped‐impedance line (SIL) is compactly folded into a right angle isosceles triangle, and the effect of the slot width between folded lines is analyzed. The designed branch‐line coupler is composed of four ATLs, so that it has a maximally compact rectangular geometry. A further miniaturization by changing patch shape and the performance analysis according to the slot widths between the four ATLs are carried out. The fabricated 3‐dB branch‐line coupler has comparable electrical performance and only 10.9% area compared to the conventional branch‐line coupler at 0.717 GHz, which is one of the smallest couplers among similar studies that have been reported. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1718–1721, 2013
A CPW‐FED Rectangular Slot Antenna for S and C Band Applications
Authors: Ung Johnny , Karacolak Tutku
Published: May 2013

The main objective of this study is to present a compact coplanar waveguide (CPW)‐fed rectangular slot patch antenna for operation in the S (2–4 GHz) and C bands (4–8 GHz). The proposed antenna has dimensions 20 × 36 × 0.5 mm3. The antenna is fabricated on a thin low loss Rogers RO3203 substrate and tested. Results are then compared with simulations. The simulated and measured −10 dB bandwidths are found to be 104% (2.48–7.86 GHz) and 103% (3.03–9.41 GHz), respectively. The antenna shows an omnidirectional radiation pattern with reasonable gain values over the same frequency band. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1714–1717, 2013
A Dual‐Band Bandpass Filter Using Capacitively I/O Coupling
Authors: Lee Jahyeon , Lim Yeongseog
Published: May 2013

A compact microstrip dual‐band bandpass filter with good frequency selectivity was proposed. The proposed dual‐band bandpass filter is configured with two dual‐mode resonator and skew‐symmetrically coupled capacitively input/output coupling. By using these input/output coupling structure, extra transmission zeros can be generated. The dual‐band bandpass filter is designed for 2.4/5.2 GHz WLAN. Experimental measurements are also presented for the validation of the theory. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1823–1825, 2013
Design of a Compact Hexa‐Band Coupling Antenna for 4g Mobile Handset Using a Small Element With Two Slots
Authors: Choi, Sunho , Jeong, Gye‐Taek , Kim Woosu
Published: May 2013

This article describes the design, fabrication, and measurement of a compact hexa‐band coupling antenna for 4G mobile handset using a small element with two slots. In order to obtain sufficient bandwidth (LTE700, GSM850, GSM900, GSM1800, GSM1900, UMTS) when Voltage Standing Wave Ratio (VSWR) ≤ 3:1, two slots are inserted in the small element, and coupling patch is used. The measured result of the fabricated antenna provides 410 MHz bandwidth from 0.688 to 1.098 GHz and 643 MHz bandwidth from 1.607 to 2.250 GHz (VSWR ≤ 3:1) with the gain ranging from −0.52 to 6.63 dBi. Also, a good radiation pattern is achieved within the hexa‐band (0.698–0.960 GHz and 1.710–2.170 GHz) range. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1708–1711, 2013
An Nmos Cross‐Coupled Quadrature Vco using Coupling Common‐Gate Pmosfets
Authors: Jang Sheng‐Lyang , Lin Hsi‐Han , Hsue Ching‐Wen
Published: May 2013

This letter presents a fully integrated cross‐coupled quadrature voltage‐controlled oscillator (QVCO) using common‐gate transistor instead of common‐source transistor as a coupling device. The prototype wide‐tuning X‐band QVCO in 0.18‐μm CMOS process is proposed to generate four output phases and consists of two n‐core cross‐coupled VCOs and four pMOS coupling devices. The proposed QVCO oscillates from 8.52 to 10.56 GHz and the power consumption is 9.76 mW at 0.8 V supply voltage. The measured phase noise is −118.88 dBc/Hz at 1‐MHz offset frequency from the carrier frequency 9.86 GHz. The QVCO occupies a chip area of 0.623 × 1.197 mm2 and provides a figure of merit of −188.86 dBc/Hz. The figure of merit including tuning range, FOMT, of this QVCO is −195.30 dBc/Hz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1705–1708, 2013
Analysis of Blockage Effects in a Center‐Fed Reflectarray
Authors: Pan Yu , Zhang Yan
Published: May 2013

Three quick methods that account for the blockage effects in a center‐fed reflectarray antenna design are presented. The first method simply adds the radiation pattern of the reflectarray on the passive feed horn antenna. For the second approach, the blockage is incorporated more accurately by introducing shadows on the reflectarray surface according to the location of the obstacles. The third approach places a physical metal sheet at the blocking obstacle on the main reflectarray surface. The radiation pattern of the complete antenna structure is also calculated using a full‐wave solver that also serves as a reference for accuracy comparison. To further validate the results, prototype reflectarray antennas based on two types of radiation elements are fabricated and the measured patterns are compared with predictions. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1921–1926, 2013