bluuebunny/crossref_metadata_2025 huggingface dataset:
β‐Endorphin expression in the mouse retina
Authors: Gallagher Shannon K. , Witkovsky Paul , Roux Michel J. , Low Malcolm J. , Otero‐Corchon Veronica , Hentges Shane T. , Vigh Jozsef
Published: March 2010

Evidence showing expression of endogenous opioids in the mammalian retina is sparse. In the present study we examined a transgenic mouse line expressing an obligate dimerized form of Discosoma red fluorescent protein (DsRed) under the control of the pro‐opiomelanocortin promoter and distal upstream regulatory elements to assess whether pro‐opiomelanocortin peptide (POMC), and its opioid cleavage product, β‐endorphin, are expressed in the mouse retina. Using double label immunohistochemistry we found that DsRed fluorescence was restricted to a subset of GAD‐67‐positive cholinergic amacrine cells of both orthotopic and displaced subtypes. About 50% of cholinergic amacrine cells colocalized DsRed and a large fraction of DsRed‐expressing amacrine cells was positive for β‐endorphin immunostaining, whereas β‐endorphin‐immunoreactive neurons were absent in retinas of POMC null mice. Our findings contribute to a growing body of evidence demonstrating that opioid peptides are an integral component of vertebrate retinas, including those of mammals. J. Comp. Neurol. 518:3130–3148, 2010. © 2010 Wiley‐Liss, Inc.
Listeria monocytogenes is sensed by the NLRP3 and AIM2 inflammasome
Authors: Kim Sarah , Bauernfeind Franz , Ablasser Andrea , Hartmann Gunther , Fitzgerald Katherine A. , Latz Eicke , Hornung Veit
Published: March 2010

The inflammasome pathway functions to regulate caspase‐1 activation in response to a broad range of stimuli. Caspase‐1 activation is required for the maturation of the pivotal pro‐inflammatory cytokines of the pro‐IL‐1β family. In addition, caspase‐1 activation leads to a certain type of cell death known as pyroptosis. Activation of the inflammasome has been shown to play a critical role in the recognition and containment of various microbial pathogens, including the intracellularly replicating Listeria monocytogenes; however, the inflammasome pathways activated during L. monocytogenes infection are only poorly defined. Here, we demonstrate that L. monocytogenes activates both the NLRP3 and the AIM2 inflammasome, with a predominant involvement of the AIM2 inflammasome. In addition, L. monocytogenes‐triggered cell death was diminished in the absence of both AIM2 and NLRP3, and is concomitant with increased intracellular replication of L. monocytogenes. Altogether, these data establish a role for DNA sensing through the AIM2 inflammasome in the detection of intracellularly replicating bacteria.
Calix[6]arene‐Picolinamide Extractants for Radioactive Waste Treatment: Effect of Additional Carboxy Binding Sites in the Pyridine 6‐Positions on Complexation, Extraction Efficiency and An/Ln Separation
Authors: Macerata Elena , Sansone Francesco , Baldini Laura , Ugozzoli Franco , Brisach Frederic , Haddaoui Jaouad , Hubscher‐Bruder Véronique , Arnaud‐Neu Françoise , Mariani Mario , Ungaro Rocco , Casnati Alessandro
Published: March 2010

The effect of the presence of an additional ester or amide carboxy group in the 6‐position of the pyridine nuclei of calixarene‐based picolinamide ligands on the extraction and complexation properties of lanthanide(III) and actinide(III) metal ions was studied. For this purpose, six new ligands 1–6 were synthesized; their conformational properties were studied both in solution and in the solid state, and their binding properties towards lanthanide (LnIII) and actinide (AnIII) metal ions were determined under extracting conditions simulating those present in radioactive waste. In the presence of BrCosan as synergizer, a rather high efficiency in the extraction of trivalent metal ions by these ligands was observed even at [HNO3] > 2–3 M. Complexation of LnIII metal ions was also studied under homogeneous conditions (methanol solution), both in chloride and nitrate media, by using spectrophotometry and calorimetry. A comparison with the data obtained with ligands L1–L3, lacking the additional binding sites in the 6‐position of the pyridine nuclei, is reported and the effects of the structure of the ligands on the stoichiometry of the complexes, coordination of the metal ions, basicity of the pyridine binding groups and efficiency and selectivity in the extractions are also discussed.
Phosphiranes as Ligands: Tungsten(0) and Palladium(0) Complexes of Phosphirano[1,2‐c][1,2,3]diazaphospholes
Authors: Maurer Stefan , Burkhart Christian , Maas Gerhard
Published: March 2010

Phosphirano[1,2‐c][1,2,3]diazaphospholes 5, which feature a strongly pyramidalized phosphorus atom at a ring fusion position, were identified as a new type of phosphane ligands for transition metals. The derivatives 5a–c smoothly form W(CO)5 complexes, which are thermally quite stable – in contrast to the known lability of various carbonylmetal complexes of simple phosphiranes. In the temperature range 120–150 °C, they undergo a clean decomplexation in toluene solution. Bicyclic phosphiranes 5a and 5b, but not the acceptor‐substituted derivative 5c, readily react with the [(E,E)‐dibenzylideneacetone]palladium(0) complex Pd2(dba)3·CHCl3 to form the corresponding isolable complexes [(5a)2(dba)Pd] and [(5b)2(dba)Pd]. In agreement with the formation of these complexes, it was found that 5a,b as ligands effectively promote the Suzuki cross‐coupling of 4‐bromotoluene with benzeneboronic acid. The solid‐state structure of bicyclic phosphirane 5b and of the complexes [(5a)(CO)5W], [(5b)2(dba)Pd] (pentane solvate) and [(5b)2(dba)Pd] (benzene solvate) were determined by X‐ray diffraction analysis.
Microfluidic cell arrays for metabolic monitoring of stimulated cardiomyocytes
Authors: Cheng Wei , Klauke Norbert , Smith Godfrey , Cooper Jonathan M.
Published: March 2010

An array of PDMS microchambers was aligned to an array of sensor electrodes and stimulating microelectrodes, which was used for the electrochemical monitoring of the metabolic activity of single isolated adult ventricular myocytes inside the chamber array, stimulated within a transient electric field. The effect of the accumulation of metabolic byproducts in the limited extracellular volume of the picolitre chambers was demonstrated by measuring single muscle cell contraction optically, while concomitant changes in intracellular calcium transients and pH were recorded independently using fluorescent indicator dyes. Both the amplitude of the cell shortening and the magnitude of the intracellular calcium transients decreased over time and both nearly ceased after 20 min of continuous stimulation in the limited extracellullar volume. The intracellular pH decreased gradually during 20 min of continuous stimulation after which a dramatic pH drop was observed, indicating the breakdown of the intracellular buffering capacity. After continuous stimulation, intracellular lactate was released into the microchamber through cell electroporation and was detected electrochemically at a lactate microbiosensor, within the chamber. A mitochondrial uncoupler was used to mimic ischaemia and thus to enhance the cellular content of lactate. Under these circumstances, intracellular lactate concentrations were found to have risen to ∼15 mM. This array system has the potential of simultaneous electrochemical and optical monitoring of extracellular and intracellular metabolites from single beating heart cells at a controlled metabolic state.
The potential of methane‐oxidizing bacteria for applications in environmental biotechnology
Authors: Wendlandt Karin‐Dagmar , Stottmeister Ulrich , Helm Jana , Soltmann Bettina , Jechorek Mirko , Beck Matthias
Published: March 2010

Methanotrophic bacteria possess a unique set of enzymes enabling them to oxidize, degrade and transform organic molecules and synthesize new compounds. Therefore, they have great potential in environmental biotechnology. The application of these unique properties was demonstrated in three case studies: (i) Methane escaping from leaky gas pipes may lead to massive mortality of trees in urban areas. Lack of oxygen within the soil surrounding tree roots caused by methanotrophic activity was identified as one of the reasons for this phenomenon. The similarity between metabolic reactions performed by the key enzymes of methanotrophs (methane monooxygenase) and ammonium oxidizers (ammonium monooxygenase) might offer a solution to this problem by applying commercially available nitrification and urease inhibitors. (ii) Methanotrophs are able to co‐metabolically degrade contaminants such as low‐molecular‐weight‐chlorinated hydrocarbons in soil and water in the presence of methane. Batch and continuous trichloroethylene degradation experiments in laboratory‐scale reactors using Methylocystis sp. GB 14 were performed, partly with cells entrapped in a polymer matrix. (iii) Using a short, two‐stage pilot‐scale process, the intracellular polymer accumulation of poly‐β‐hydroxybutyrate (PHB) in methanotrophs reached a maximum of 52%. Interestingly, an ultra‐high‐molecular‐weight PHB of 3.1 MDa was accumulated under potassium deficiency. Under strictly controlled conditions (temperature, pH and methane supply) this process can be nonsterile because of the establishment of a stable microbial community (dominant species Methylocystis sp. GB 25 ≥86% by biomass). The possibility to substitute methane with biogas from renewable sources facilitates the development of a methane‐based PHB production process that yields a high‐quality biopolymer at competitive costs.
Analytical approach to Boussinesq equation with space‐ and time‐fractional derivatives
Authors: Yıldırım Ahmet , Sezer Sefa Anıl , Kaplan Yasemin
Published: March 2010

In this paper, the homotopy perturbation method (HPM) is developed to obtain approximate analytical solutions of a fractional Boussinesq equation with initial condition. The fractional derivatives are described in the Caputo sense. Some examples are given and comparisons are made, the comparisons show that the HPM is very effective and convenient and overcomes the difficulty of traditional methods. The numerical results show that the approaches are easy to implement and accurate when applied to space‐ and time‐fractional equations. Copyright © 2010 John Wiley & Sons, Ltd.
Deafferentation enhances neurogenesis in the young and middle aged hippocampus but not in the aged hippocampus
Authors: Shetty Ashok K. , Hattiangady Bharathi , Rao Muddanna S. , Shuai Bing
Published: March 2010

Increased neurogenesis in the dentate gyrus (DG) after brain insults such as excitotoxic lesions, seizures, or stroke is a well known phenomenon in the young hippocampus. This plasticity reflects an innate compensatory response of neural stem cells (NSCs) in the young hippocampus to preserve function or minimize damage after injury. However, injuries to the middle‐aged and aged hippocampi elicit either no or dampened neurogenesis response, which could be due to an altered plasticity of NSCs and/or the hippocampus with age. We examined whether the plasticity of NSCs to increase neurogenesis in response to a milder injury such as partial deafferentation is preserved during aging. We quantified DG neurogenesis in the hippocampus of young, middle‐aged, and aged F344 rats after partial deafferentation. A partial deafferentation of the left hippocampus without any apparent cell loss was induced via administration of Kainic acid (0.5 μg in 1.0 μl) into the right lateral ventricle of the brain. In this model, degeneration of CA3 pyramidal neurons and dentate hilar neurons in the right hippocampus results in loss of commissural axons which leads to partial deafferentation of the dendrites of dentate granule cells and CA1‐CA3 pyramidal neurons in the left hippocampus. Quantification of newly born cells that are added to the dentate granule cell layer at postdeafferentation days 4–15 using 5′‐bromodeoxyuridine (BrdU) labeling revealed greatly increased addition of newly born cells (∼three fold increase) in the deafferented young and middle‐aged hippocampi but not in the deafferented aged hippocampus. Measurement of newly born neurons using doublecortin (DCX) immunostaining also revealed similar findings. Analyses using BrdU‐DCX dual immunofluorescence demonstrated no changes in neuronal fate‐choice decision of newly born cells after deafferentation, in comparison to the age‐matched naive hippocampus in all age groups. Thus, the plasticity of hippocampal NSCs to increase DG neurogenesis in response to a milder injury such as partial hippocampal deafferentation is preserved until middle age but lost at old age. © 2010 Wiley‐Liss, Inc.
Overexpression of LSD1 contributes to human carcinogenesis through chromatin regulation in various cancers
Authors: Hayami Shinya , Kelly John D. , Cho Hyun‐Soo , Yoshimatsu Masanori , Unoki Motoko , Tsunoda Tatsuhiko , Field Helen I. , Neal David E. , Yamaue Hiroki , Ponder Bruce A.J. , Nakamura Yusuke , Hamamoto Ryuji
Published: March 2010

A number of histone demethylases have been identified and biochemically characterized, but the pathological roles of their dysfunction in human disease like cancer have not been well understood. Here, we demonstrate important roles of lysine‐specific demethylase 1 (LSD1) in human carcinogenesis. Expression levels of LSD1 are significantly elevated in human bladder carcinomas compared with nonneoplastic bladder tissues (p < 0.0001). cDNA microarray analysis also revealed its transactivation in lung and colorectal carcinomas. LSD1‐specific small interfering RNAs significantly knocked down its expression and resulted in suppression of proliferation of various bladder and lung cancer cell lines. Concordantly, introduction of exogenous LSD1 expression promoted cell cycle progression of human embryonic kidney fibroblast cells. Expression profile analysis showed that LSD1 could affect the expression of genes involved in various chromatin‐modifying pathways such as chromatin remodeling at centromere, centromeric heterochromatin formation and chromatin assembly, indicating its essential roles in carcinogenesis through chromatin modification.
Gauging the effect of compositional and curricular diversity on freshman success
Authors: Herzog Serge
Published: March 2010

Findings connect cognitive growth and enrollment persistence to racial diversity in the classroom using objective measures.
Half metallic properties of LaSrVMoO6
Authors: Song Weiyu , Wang Jing , Meng Jian , Wu Zhijian
Published: March 2010

The recent synthesized LaSrVMoO6 was speculated to be compensated half metal, i.e., half metal with zero magnetic moment. Based on the experimental structure, our first principles study indicates that it is ferrimagnetic and half metallic with the magnetic moment 2.0 μB when the electron correlation of Mo 4d electrons is larger than 2.72 eV. This indicates the strong electron correlation effect of Mo 4d electrons. Nonetheless, the obtained large magnetic moment (2.0 μB) contradicts with the experimental observed nearly zero magnetic moment. Although the large antisite defects of the experimental sample might be the reason to reduce the saturated magnetic moment, further physical insights need to be investigated. The spin‐orbit coupling effect has minor effect on the studied properties. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
High‐throughput single‐base mismatch detection for genotyping of UDP‐glucuronosyltransferase (UGT1A1) with probe capture assay coupled with modified allele‐specific primer extension reaction (MASPER)
Authors: Kisaki Osamu , Kato Seiji , Shinohara Kohei , Hiura Hisahide , Samori Tomohiro , Sato Hiroshi
Published: March 2010

We have developed a new method based on specific primer extension reactions coupled with plate hybridization for high‐throughput genotyping of single‐base mutations. To improve the switching characteristics of the primer extension reaction, we introduced an artificial mismatch two bases upstream of the 3′‐terminal base in the detection primers. A set of primers that correspond to wild‐type and mutant DNA segments can be used to accurately analyze single‐base mutations. The termini of these primers are at the mutation positions. The primer extension products produced by polymerase chain reaction (PCR) were captured by an oligonucleotide probe immobilized on the surface of microtiter wells and were detected by a colorimetric assay using the streptavidin‐conjugated horseradish peroxidase. We used the new method to genotype 96 individuals for 211G>A (G71R) and 119 for 1456T>G (Y486D) in the UDP‐glucuronosyltransferase1A1 gene; the results were completely concordant with those found by direct sequencing. The proposed method includes ordinary PCR and a microplate assay format, and may be used in routine laboratory tests. J. Clin. Lab. Anal. 24:85–91, 2010. © 2010 Wiley‐Liss, Inc.
Physical inactivity and cardiovascular risk: baseline observations from men and premenopausal women
Authors: Garelnabi Mahdi , Veledar Emir , Abramson Jerome , White‐Welkley Jill , Santanam Nalini , Weintraub William , Parthasarathy Sampath
Published: March 2010

Introduction: Physical activity or exercise is a proven deterrent of cardiovascular (CV) diseases. Purpose: In this study, we examined the relationships between baseline values of parameters related to physical activity and known markers of CV disease, including markers of oxidative stress. Methods: A total of 455 healthy men and women between the ages of 18 and 50 were recruited to participate in the study. Levels of lipids/lipoproteins and markers of oxidative stress and inflammation were measured along with the VO2 and duration time spent on treadmill. Results: Women, in general, had a significantly (P<0.0001) higher plasma high density lipoprotein (1.51±0.30 mmol/l), decreased (P<0.0001) low density lipoprotein (LDL) (2.75±0.66 mmol/l), and decreased (P<0.0001) triglycerides levels (2.09±0.85 mmol/l), compared with males (1.21±0.23 mmol/l, 2.92±0.81 mmol/l, and 3.02±1.34 mmol/l, respectively). There was a direct correlation between the levels of plasma LDL and the levels oxidized LDL levels (P<0.0001) in both men and women. Despite a better antiatherogenic lipid profile, the levels of C‐reactive protein in women were significantly (P<0.0001) elevated (3.78±3.66 ng/ml) as compared with those in men (1.82±2.37 ng/ml). Conclusion: These results suggest intrinsic sex differences between men and women in relation to atherogenic risk. J. Clin. Lab. Anal. 24:100–105, 2010. © 2010 Wiley‐Liss, Inc.
A glycine site‐specific NMDA receptor antagonist protects retina ganglion cells from ischemic injury by modulating apoptotic cascades
Authors: Qiu Weiqiang , Wei Ruoxin , Zhang Chi , Zhang Chun , Leng Wen , Wang Wei
Published: March 2010

Glutamate neurotoxicity is one of the causative factors leading to neural degeneration including retina. Inhibition of NMDA receptors has been shown neuroprotective effects. However, specifically inhibition of glycine subunit in NMDA receptors and its effects on retina neural protection has not been tested. In this study, using a glycine site‐specific NMDA receptor antagonist, we investigated its neuroprotective effects on rat retinal ganglion cells (RGCs) from a transient ischemic injury and its possible underlying mechanisms. Following an ischemia/reperfusion injury the structural damages of rat retinas were assessed by an immunofluorescence method and the apoptosis of retinal neural cells was evaluated by using a terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) method. The survived RGCs were labeled by retrograde manner and counted on whole‐mounted retinas. In the presence of glycine site‐specific NMDA receptor antagonist, the thickness of retina was sustained, especially in the inner nuclear layers compared with mock controls. While a significantly higher numbers of TUNEL‐positive apoptotic cells and fewer of RGCs were observed in the retina without the glycine antagonist, indicating its strong protective roles. Some apoptotic factors such as Bax, Bcl‐2, CAMK II, COX1, COX4, Caspase‐3, and GRIN1 gene have been tested from retinal samples with or without the glycine antagonist. A significantly lower of expressions of Bax, CAMK II, COX1, COX4, Caspase‐3, and GRIN1 have been shown in the retinas with the antagonist. Bcl‐2/Bax ratio was significantly higher with the antagonist, suggested that the glycine site‐specific NMDA receptor antagonist protecting RGC death might through inhibition of apoptotic signaling. J. Cell. Physiol. 223:819–826, 2010. © 2010 Wiley‐Liss, Inc.
Proprotein convertase subtilisin/kexin type 9 (PCSK9) affects gene expression pathways beyond cholesterol metabolism in liver cells
Authors: Lan Hong , Pang Ling , Smith Marsha M. , Levitan Diane , Ding Wei , Liu Li , Shan Lixin , Shah Vidhi V. , Laverty Maureen , Arreaza Gladys , Zhang Qing , Murgolo Nicholas J. , Hernandez Marco , Greene Jonathan R. , Gustafson Eric L. , Bayne Marvin L. , Davis Harry R. , Hedrick Joseph A.
Published: March 2010

Proprotein convertase subtilisin/kexin type 9 (PCSK9) induces degradation of low‐density lipoprotein receptor (LDLR) in the liver. It is being pursued as a therapeutic target for LDL‐cholesterol reduction. Earlier genome‐wide gene expression studies showed that PCSK9 over‐expression in HepG2 cells resulted in up‐regulation of genes in cholesterol biosynthesis and down‐regulation of genes in stress response pathways; however, it was not known whether these changes were directly regulated by PCSK9 or were secondary to PCSK9‐induced changes to the intracellular environment. In order to further understand the biological function of PCSK9 we treated HepG2 cells with purified recombinant wild type (WT) and D374Y gain‐of‐function PCSK9 proteins for 8, 24, and 48 h, and used microarray analysis to identify genome‐wide expression changes and pathways. These results were compared to the changes induced by culturing HepG2 cells in cholesterol‐free medium, mimicking the intracellular environment of cholesterol starvation. We determined that PCSK9‐induced up‐regulation of cholesterol biosynthesis genes resulted from intracellular cholesterol starvation. In addition, we identified novel pathways that are presumably regulated by PCSK9 and are independent of its effects on cholesterol uptake. These pathways included “protein ubiquitination,” “xenobiotic metabolism,” “cell cycle,” and “inflammation and stress response.” Our results indicate that PCSK9 affects metabolic pathways beyond cholesterol metabolism in HepG2 cells. J. Cell. Physiol. 224:273–281, 2010 © 2010 Wiley‐Liss, Inc.
EV71 induces COX‐2 expression via c‐Src/PDGFR/PI3K/Akt/p42/p44 MAPK/AP‐1 and NF‐κB in rat brain astrocytes
Authors: Tung Wei‐Hsuan , Lee I‐Ta , Hsieh Hsi‐Lung , Yang Chuen‐Mao
Published: March 2010

Enterovirus 71 (EV71) induces the expression of cyclooxgenase (COX)‐2 served as a major neurotoxic factor in CNS injury. However, the mechanisms underlying EV71‐initiated intracellular signaling pathways leading to COX‐2 expression remain unknown. Therefore, we investigated the mechanisms underlying EV71‐induced COX‐2 expression and prostaglandin E2 (PGE2) production in rat brain astrocytes (RBA)‐1, determined by Western blotting, RT‐PCR, and promoter assay. Here, we reported that EV71‐indued COX‐2 expression and PGE2 production were attenuated by pretreatment with the inhibitors of c‐Src (PP1), PDGFR (AG1296), PI3K (Wortmannin), MEK1/2 (PD98059), NF‐κB (helenalin), and AP‐1 (Tanshinone) and transfection with shRNA or siRNA of c‐Src, PDGFR, p85, c‐Jun, c‐Fos, ERK1, or ERK2. We further observed that EV71‐induced activation of Akt and p42/p44 MAPK were mediated via c‐Src and PDGFR. Pretreatment with PP1 attenuated EV71‐stimulated phosphorylation of Src, PDGFR, Akt, and p42/p44 MAPK. Inhibition of PI3K by Wortmannin attenuated EV71‐induced Akt and p42/p44 MAPK phosphorylation, but had no effect on PDGFR phosphorylation, suggesting that PDGFR is an upstream and p42/p44 MAPK is a downstream component of PI3K/Akt in these responses. EV71‐stimulated NF‐κB translocation from the cytoplasm to the nucleus, IκBα degradation and NF‐κB promoter activity were attenuated by pretreatment with helenalin, but not AG1296, Wortmannin, and PD98059. EV71‐induced c‐Jun mRNA expression was attenuated by pretreatment with PD98059, AG1296, or Wortmannin. These results demonstrate that in RBA‐1 cells, EV71‐induced COX‐2 expression associated with PGE2 production is mediated through activation of c‐Src/PDGFR/PI3K/Akt/p42/p44 MAPK to initiate the expression of AP‐1. J. Cell. Physiol. 224: 376–386, 2010. © 2010 Wiley‐Liss, Inc.
Use of sweet sorghum juice for lactic acid fermentation: preliminary steps in a process optimization
Authors: Hetényi Kata , Gál Kinga , Németh Áron , Sevella Béla
Published: March 2010

BACKGROUND: Lactic acid has many applications in the chemical industries and it can be produced economically by microorganisms using biomass raw materials of different origins. Sweet sorghum juice is a high sugar content raw material with potential for lactic acid production because after hydrolysis of its sucrose content the remaining glucose and fructose can supply the carbon demand of most lactic acid bacteria. However, satisfying the nitrogen and B‐vitamin needs of the bacteria by supplementation with yeast extract and/or other alternative nitrogen‐containing supplements can make the process too expensive.

RESULTS: Using a statistical optimization process much of the yeast extract can be replaced by a cheaper alternative nitrogen source, namely wheat gluten. This resulted in a fermentation with 99% lactic acid yield and 3.04 g L−1 h−1 volumetric productivity.

CONCLUSION: Using response surface methodology (RSM) media optimization was performed for lactic acid fermentation with an industrially acceptable result, reducing the costs of raw materials by half, replacing yeast extract by an alternative nitrogen source and applying yeast extract only as a source of micro‐elements (vitamins, salts, etc.) Copyright © 2010 Society of Chemical Industry
Study of the optimisation of puffing characteristics of potato cubes by spouted bed drying enhanced with microwave
Authors: Yan Wei‐qiang , Zhang Min , Huang Lue‐lue , Tang Juming , Mujumdar Arun S , Sun Jin‐cai
Published: March 2010

BACKGROUND: In commercial deep‐fat frying of potato chips, the oil content of the final products ranges from 35 to 45 g 100 g−1 (wet basis). High‐temperature frying may cause the formation of acrylamide, making the products unhealthy to the consumer. The aim of this research was to explore a new method, spouted bed microwave drying, to produce healthier puffed snack potato cubes as possible alternatives to oil‐fried potato chips. The influence of drying conditions of the spouted bed microwave drying on puffing characteristics of potato cubes were studied and compared with the direct microwave and hot air drying method.

RESULTS: Tandem combination drying of microwave‐enhanced spouted bed drying (MWSB) could achieve a good expansion ratio, breaking force and rehydration ratio. The puffing characteristics of potato cubes were significantly affected (P < 0.05) by moisture content before starting microwave power in spouted bed microwave drying, by microwave (MW) power, and by the original size of potato cubes.

CONCLUSION: The optimum processing parameters were the moisture content at the start of microwave power (60%), the size of potato cubes (10–12 mm), and microwave power (2–2.5 W g−1) Copyright © 2010 Society of Chemical Industry
In vitro investigation of wavelength‐dependent tissue ablation: Laser prostatectomy between 532 nm and 2.01 µm
Authors: Kang Hyun Wook , Kim Jihoon , Peng Yihlih Steven
Published: March 2010

Background and Objective

Over a decade, laser prostatectomy has been performed to effectively treat benign prostate hyperplasia (BPH) with low post‐operative complications. In this study, two laser wavelengths conventionally used for BPH treatment were compared to characterize the outcomes of in vitro tissue ablation.

Study Design/Materials and Methods

Two lasers with wavelengths including 532 nm (Q‐switched) and 2.01 µm (continuous wave) were employed to ablate porcine kidney tissue in vitro. Ablation performance was evaluated by varying applied power, treatment speed, and fiber working distance. Optical transmission was measured as a function of working distance and compared with the corresponding ablation volume. Coagulation depth was quantified from gross tissue examination, and histology analysis confirmed coagulation features for both wavelengths.

Results

Five hundred thirty‐two nanometers yielded up to 30% (P<0.005) higher ablation efficiency than 2.01 µm. Regardless of wavelength, ablation rate increased with power and was maximized at treatment speed of 4 mm/seconds. A comparable ablation depth was found between the two wavelengths, but 532 nm generated relatively wider (up to 30%; P<0.005) craters. Both optical transmission and ablation volume revealed that energy loss by strong water absorption compromised ablation efficiency generated by 2.01 µm. Gross tissue and histology examination demonstrated that 532 nm created a thin coagulation zone whereas 2.01 µm induced ∼20% (P<0.005) more thermal injury in association with carbonized tissue surface.

Conclusions

Due to more light scattering and effective thermal confinement, 532 nm induced more efficient tissue ablation with a smaller coagulative necrotic zone. Comparable ablation depth may enable a potential tissue incision technique with 532 nm, possibly allowing both tissue removal and biopsy intraoperatively. Lasers Surg. Med. 42:237–244, 2010. © 2010 Wiley‐Liss, Inc.
Cellular and molecular effects of pulsed dye laser and local narrow‐band UVB therapy in psoriasis
Authors: Rácz Emőke , de Leeuw Jaap , Baerveldt Ewout M. , Kant Marius , Neumann H.A. Martino , van der Fits Leslie , Prens Errol P.
Published: March 2010

Background and Objectives

Pulsed dye laser (PDL) therapy is effective in clearing psoriasis plaques, but the mechanism of action is only partially understood. Local narrow‐band ultraviolet B (NB‐UVB), which has a better‐defined mode of action, is an effective standard treatment for psoriasis. Our aim was to evaluate the cellular and molecular effects of PDL and to compare them with those of local NB‐UVB in order to gain further insight into their mechanisms of action in psoriasis.

Study Design/Patients and Methods

Nineteen patients with stable plaque‐type psoriasis were treated either with PDL or NB‐UVB. Lesional punch biopsies were obtained from all patients before treatment. Additional biopsies were obtained at 3 and 24 hours after PDL treatment in five of these patients. In 14 patients additional biopsies were taken after 7 and 13 weeks of treatment. Samples were histopathologically examined for the level of dermal T cell infiltrate, and the expression of epidermal β‐defensin 2, immune cell‐derived tumor necrosis factor (TNF)‐α, endothelial E‐selectin, vascular endothelial growth factor receptor (VEGFR) 2 and 3, and the expression of interleukin (IL)‐23 before and after treatment.

Results

The expression of VEGFR2, VEGFR3, and E‐selectin was decreased in clinically high responders within 24 hours after PDL treatment. The expression of IL‐23, TNF‐α mRNA, and E‐selectin protein were significantly reduced after two PDL treatments, whereas the expression of all epidermal markers and dermal T cell infiltrates had normalized after four treatments. The expression of epidermal activation markers and E‐selectin were significantly reduced after 13 weeks of NB‐UVB treatment.

Conclusions

The expression of epidermal activation markers and the dermal T cell infiltrates were decreased after both treatments. The decreased expression of VEGFR2 and VEGFR3 followed by the down‐regulation of TNF‐α and IL‐23p19 may be contributory factors in the efficacy of PDL in stable plaque‐type psoriasis. Lasers Surg. Med. 42:201–210, 2010. © 2010 Wiley‐Liss, Inc.
Triggering of dendritic cell apoptosis by xanthohumol
Authors: Xuan Nguyen Thi , Shumilina Ekaterina , Gulbins Erich , Gu Shuchen , Götz Friedrich , Lang Florian
Published: March 2010

Xanthohumol, a flavonoid from beer with anticancer activity is known to trigger apoptosis in a variety of tumor cells. Xanthohumol further has anti‐inflammatory activity. However, little is known about the effect of xanthohumol on survival and function of immune cells. The present study thus addressed the effect of xanthohumol on dendritic cells (DCs), key players in the regulation of innate and adaptive immunity. To this end, mouse bone marrow‐derived DCs were treated with xanthohumol with subsequent assessment of enzymatic activity of acid sphingomyelinase (Asm), ceramide formation determined with anti‐ceramide antibodies in FACS and immunohistochemical analysis, caspase activity utilizing FITC conjugated anti‐active caspase 8 or caspase 3 antibodies in FACS and by Western blotting, DNA fragmentation by determining the percentage of cells in the sub‐G1 phase and cell membrane scrambling by annexin V binding in FACS analysis. As a result, xanthohumol stimulated Asm, enhanced ceramide formation, activated caspases 8 and 3, triggered DNA fragmentation and led to cell membrane scrambling, all effects virtually absent in DCs from gene targeted mice lacking functional Asm or in wild‐type cells treated with sphingomyelinase inhibitor amitriptyline. In conclusion, xanthohumol stimulated Asm leading to caspase activation and apoptosis of bone marrow‐derived DCs.
Broadband electrically small antenna using two electromagnetically coupled radiators
Authors: Cho Chihyun , Park Ikmo , Choo Hosung
Published: March 2010

We propose an electrically small antenna that achieves broad bandwidth with small antenna size. This antenna is composed of a hemispherical disk‐loaded monopole and a hemispherically wound helix to maximize the disk loading effect and the electromagnetic coupling between the two radiating elements in a given space. The fabricated antenna is 10.7 cm in size (kr = 0.449) and exhibits a measured −3 dB bandwidth of about 30% for a center frequency of 200 MHz. The antenna also achieves a radiation efficiency of over 85% and a transmission loss similar to that of a conventional λ/4 monopole, despite the fact that size of the antenna is about 30% that of the λ/4 monopole. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1369–1372, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25164
Design of dual‐band annular slot antenna with strip‐loaded approach
Authors: Chiang Meng‐Ju , Tseng Ching‐Hung , Sze Jia‐Yi , Bor Sheau‐Shong
Published: March 2010

This article investigation develops and experimentally explores the dual‐band design for a compact coplanar waveguide (CPW)‐fed annular slot antenna loaded with conducting strips.In the proposed strip‐loaded design, the arc‐like metal strips excite the first resonant mode at the operating frequency, which is lower than that of the annular slot antenna, to achieve miniaturization. The prototype is implemented on a 0.8 mm FR‐4 substrate with εr = 4.4; the outer and inner radii of the compact annular slot are 9.0 mm and 6.5 mm, respectively. The return loss of the proposed design reveals two operating bands with a VSWR of 2.5: 1 over bandwidths of 3.5% and 9.8%, respectively. Two resonant bands exhibit the broadside radiation patterns with the peak antenna gains of 1.3 dBi and 4.9 dBi, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1398–1402, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25165
Efficient generation of RF using a biased soliton generating nonlinear transmission line with a bipolar input
Authors: Marksteiner Quinn R. , Carlsten Bruce , Russell Steve
Published: March 2010

A method of generating more efficient RF from a soliton generating nonlinear lumped element, transmission line (NLETL) is presented.A bipolar input is coupled into an NLETL, which is DC, biased to the amplitude of the input pulse. The input evolves into a soliton containing pulse that would take twice as much power to produce from a unipolar input. Simulations demonstrate that, this method increases the maximum RF generating efficiency of an NLETL from 1/3 for a unipolar input pulse to 2/3 for a bipolar input pulse to a biased line, in agreement with simple analytical arguments. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1411–1413, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25170
Miniaturized band‐pass filter for broadband applications
Authors: Karim M. F. , Liu A.Q. , Ong L. C. , Guo Yong‐Xin
Published: March 2010

This article reports a new compact design of band‐pass filter for broadband applications. It has a compact design with two bended short stubs of quarter‐wavelength and a connecting stub of half‐wavelength, which result in the design of a broadband filter. The filter is fabricated on silicon substrate using surface micromachining process. The fractional bandwidth of band‐pass filter reported is around 0.9–4 GHz. The rejection at upper and lower pass band edge is greater than 35 dB, and the insertion loss is 2.4 dB. The area of the novel filter is (λg/4)2 at the centre frequency of the bandpass, whereas the area of the filter realized using the nonbending stubs and connecting lines is 2(λg/4)2 for the same band pass characteristics. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1372–1375, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25177
Refractive‐index sensor based on tilted fiber Bragg grating interacting with multimode fiber
Authors: Jin Yongxing , Dong Xinyong , Gong Huaping , Shen Changyu
Published: March 2010

A simple refractive‐index fiber sensor based on a tilted Bragg fiber grating (TFBG) interacting with multimode fiber (MMF) is described. The sensor structure is formed by insertion of a small section of MMF between the single‐mode fiber and the TFBG. The average reflective power in the cladding modes of the TFBG reflected a different power as the surrounding refractive index changes, while the power of the reflected Bragg mode keeps unchanged. Therefore, the power of the reflected Bragg mode can be used as a reference to compensate any possible fluctuation of the light source power. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1375–1377, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25178
Design of stepped‐impedance hairpins band‐pass filter with wide stopband performance
Authors: Ho Min‐Hua , Lin Wei‐Chen
Published: March 2010

In this article, the band‐pass filter (BPF) of stepped‐impedance hairpin (SIH) design having a very wide stopband performance was proposed.The filter composed of two SIHs connected by a narrow bended microstrip with the latter's middle point shorting to the ground through a via hole. A long narrow coupled microstrip was used to couple I/O signal to/from the SIH resonators. The filter operated at a quarter‐wavelength resonance condition was built for WLAN IEEE 802.11b/g (2.4/2.45 GHz) applications. The filter's upper stopband had its frequency range measured from 2.76 to 23.08 GHz with the criterion of the signal rejection levels greater than 20 dB. The stopband's upper‐end is over 9.5 f0 (with central frequency, f0 = 2.44 GHz). Experiment was conducted for the circuit validation and a good agreement was observed between the measurement and simulation. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1405–1408, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25179
A reconfigurable design for bandwidth enhancement of circularly polarized slot antennas
Authors: Hsieh Tsung‐Hsun , Row Jeen‐Sheen
Published: March 2010

A reconfigurable design is proposed to improve the circular polarization (CP) operating bandwidth of an annular‐ring slot antenna fed with an L‐shaped coupling strip.The design involves four voltage‐controlled varactor diodes, which are placed below the slot and symmetrically distributed along the circumference of the slot. When all antenna dimensions remain constant, the CP operating frequency of the slot antenna can be decreased by varying dc voltage values. In addition, theses CP operating frequencies, which are corresponding to different dc voltage values can form a successive frequency band, and the available CP bandwidth is thus improved. Experimental results indicate that with the reconfigurable design, the 3‐dB axial‐ratio CP bandwidth can be increased by a factor of 4 for the annular‐ring slot antenna with a reflector. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1377–1380, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25192
Half‐cut disc UWB antenna with tapered CPW structure for USB application
Authors: Liu Wen‐Jian , Chu Qing‐Xin
Published: March 2010

A novel half disc for ultra wide band (UWB) application is proposed with the beveled ground and tapered coplanar waveguide‐fed structure. Its impedance bandwidth ranges from 2.42 to 13.62 GHz, which covers the entire UWB band. Its dimension is as small as 11 mm × 29.3 mm. As a result, it can be easily integrated into the wireless USB equipments. The simulated and measured results have a relative good agreement. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1380–1384, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25193
A miniaturized low‐profile antenna for WLAN communications
Authors: Wu Weijun , Yin Yingzeng , Zhao Yulong , Zuo Shaoli
Published: March 2010

The design of a miniaturized low‐profile monopole patch antenna is investigated.The printed configuration consists of a shorted center‐fed circular patch and a shorted concentric parasitic annular ring. Compared with the center‐fed circular patch antennas, this ensemble is a lower profile of 0.08λ0 (at 2.442 GHz) and a smaller annular ring radius of 0.13λ0 with 13.7% impedance bandwidth VSWR ≤ 2. Also, it has an average gain 3.5 dBi and omnidirectional radiation and is suitable for indoor wireless local area networks. The measured results are in good agreement with the simulated ones. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1384–1386, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25203
Novel quantum‐molecular transporter and networking via a wavelength router
Authors: Threepak T. , Louangvilay X. , Mitatha S. , Yupapin P. P.
Published: March 2010

We propose a new system of a molecular‐quantum networking using the optical tweezers, where the transportation of molecules via wavelength router and network can be performed. In addition, the molecule transportation states can be identified by using the quantum states of the transporters, which can be formed in the network. The proposed fabricated material used is InGaAsP/InP, which can provide the required output signals. The design system consists of a nonlinear microring/nanoring resonator system incorporating an add/drop filter and a wavelength router. The transporter can be formed by the dark soliton, and the optical transporter is tuned and amplified by the bright soliton and transmitted into the network. In applications, the use of the proposed system incorporating a nanoscale communication and networking via wavelength router is available for long‐distance link. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1353–1357, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25204
Multiple Brillouin Stokes generation with bismuth‐based erbium‐doped fiber
Authors: Shahi S. , Harun S. W. , Dimyati K. , Tamjis M.R. , Ahmad H.
Published: March 2010

A multiple Brillouin Stokes generation is demonstrated at extended L‐band region using the bismuth‐based erbium‐doped fiber (Bi‐EDF) in the linear cavity. A 2.15‐m long Bi‐EDF is used to provide both nonlinear and linear gains to generate a stimulated Brillouin scattering (SBS) and to amplify the generated SBS, respectively. The Brillouin erbium fiber laser operates at 1615 nm region with more than 40 Stokes and anti‐Stokes lines, and the line spacing is measured to be ∼0.09 nm. Based on the four‐wave mixing signals spacing, the dispersion coefficient of the Bi‐EDF is estimated to be ∼95 ps/nm/km. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1416–1418, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25207
High impedance wire composite right/left‐handed transmission lines
Authors: Safwat Amr M. E.
Published: March 2010

This article presents a balanced composite right/left‐handed (CRLH) transmission line using high impedance wire.No vias are required in the proposed implementation. However, processing of double surfaces is needed. The proposed structure provides multiple CRLH bands. The concept was validated in microstrip configuration, and equivalent circuit model was proposed and theoretical expectations were confirmed by EM simulations and measurements. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1390–1393, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25215
Membrane technology for band‐pass filter in W‐band
Authors: Vu Thanh Mai , Prigent Gaetan , Plana Robert
Published: March 2010

This article deals with the design of coplanar waveguide band‐pass filters in W‐band implemented on silicon membrane technology. Several topologies of filters are developed at 94 GHz: broadband filters with stubs, narrow band filters with coupled‐lines, and a pseudo‐elliptical ring. Different concepts are validated by electromagnetic simulations HFSS and by experimental results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1393–1397, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25216
A 90 nm CMOS dual‐band divide‐by‐2 and ‐4 injection‐locked frequency divider
Authors: Jang Sheng‐Lyang , Wu Yuan‐Kai , Chang Chia‐Wei , Huang Jhin‐Fang , Liu Cheng‐Chen
Published: March 2010

A fourth‐order resonator has been implemented to design a 65 GHz injection‐locked frequency divider (ILFD) implemented in a 90 nm CMOS process.The ILFD is realized with a cross‐coupled nMOS LC‐tank oscillator with an inductor switch for frequency band selection. The LC tank can be a second‐or fourth‐order resonator depending upon the on/off state of a switch across a series‐tuned inductor. Measurement results show that at the supply voltage of 0.5 V, the free‐running frequency is from 8.68 (16.147) to 9.928 (17.89) GHz for the low‐ (high‐) frequency band. The divide‐by‐2 operational locking range is from 14.9 (30.64) to 22.2 (37.74) GHz for the low‐(high)‐frequency band. The divide‐by‐4 operational locking range is from 34.4 (64.6) to 40.35 (67) GHz for the low‐(high)‐frequency band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1421–1425, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25217
Compact and ultra‐low‐loss planar photonic crystal taper
Authors: Wahsheh Rami A. , Abushagur Mustafa A. G.
Published: March 2010

We propose a novel method to enhance the coupling efficiency between a dielectric waveguide and a planar photonic crystal (PC). The proposed method is based on introducing structural imperfections to change the mode size and shape inside the taper to match that of the PC line‐defect waveguide. This method involves changing both the size and position of the inner taper rods. We found that the transmission efficiency is above 88% for the size change method, while it is above 94% for the position change method. The order of which method to apply first is important. Our results show that applying the size change method, followed by the position change method increases the coupling to about 96% without affecting the transmission spectrum of the structure. We also found that the input and output taper geometries are different because light faces different scattering mechanisms when entering or exiting the line defect waveguide. (2009 Wiley Periodicals, Inc). © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1454–1459, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25222