bluuebunny/crossref_metadata_2025 huggingface dataset:
Homocysteine–NMDA receptor‐mediated activation of extracellular signal‐regulated kinase leads to neuronal cell death
Authors: Poddar Ranjana , Paul Surojit
Published: June 2009

Hyperhomocysteinemia is an independent risk factor for stroke and neurological abnormalities. However, the underlying cellular mechanisms by which elevated homocysteine can promote neuronal death is not clear. In the present study we have examined the role of NMDA receptor‐mediated activation of the extracellular signal‐regulated kinase‐mitogen‐activated protein (ERK‐MAP) kinase pathway in homocysteine‐dependent neurotoxicity. The study demonstrates that in neurons l‐homocysteine‐induced cell death was mediated through activation of NMDA receptors. The study also shows that homocysteine‐dependent NMDA receptor stimulation and resultant Ca2+ influx leads to rapid and sustained phosphorylation of ERK‐MAP kinase. Inhibition of ERK phosphorylation attenuates homocysteine‐mediated neuronal cell death thereby demonstrating that activation of ERK‐MAP kinase signaling pathway is an intermediate step that couples homocysteine‐mediated NMDA receptor stimulation to neuronal death. The findings also show that cAMP response‐element binding protein (CREB), a pro‐survival transcription factor and a downstream target of ERK, is only transiently activated following homocysteine exposure. The sustained activation of ERK but a transient activation of CREB together suggest that exposure to homocysteine initiates a feedback loop that shuts off CREB signaling without affecting ERK phosphorylation and thereby facilitates homocysteine‐mediated neurotoxicity.
MEASURING PRO‐POORNESS: A UNIFYING APPROACH WITH NEW RESULTS
Authors: Essama‐Nssah B. , Lambert Peter J.
Published: June 2009

Recent economic literature on pro‐poor growth measurement is drawn together, using a common analytical framework which lends itself to some significant extensions. First, a new class of pro‐poorness measures is defined, to complement existing classes, with similarities and differences which are fully discussed. Second, all of these measures of pro‐poorness can be decomposed across income sources or components of consumption expenditure (depending on the application). This permits the analyst to “unbundle” a pattern of growth, revealing the contributions to overall pro‐poorness of constituent parts. Third, all of these pro‐poorness measures can be modified to measure pro‐poorness at percentiles. An application to consumption expenditures in Indonesia in the 1990s reveals that the poverty reduction achieved remains far below what would have been achieved under distributional neutrality. This can be tracked back to changes in expenditure components.
Phylogenetic analysis of hepatitis A virus in sera from patients with hepatitis A of various severities
Authors: Fujiwara Keiichi , Kojima Hiroshige , Yonemitsu Yutaka , Yasui Shin , Imazeki Fumio , Miki Makoto , Suzuki Kazuyuki , Sakaida Isao , Okita Kiwamu , Tanaka Eiji , Omata Masao , Yokosuka Osamu
Published: June 2009

Background: We analysed the association of the 5′ nontranslated region (5′NTR), nonstructural proteins 2B and 2C of the hepatitis A virus (HAV) genome, whose mutations have previously been shown to be important for enhanced replication in cell culture systems, in order to align all our data and examine whether genomic differences in HAV are responsible for the range of clinical severities.

Methods: Our accumulated HAV strains of 5′NTR [nucleotide(nt) 200 and 500], entire 2B and 2C from 25 Japanese patients with sporadic hepatitis A, consisting of seven patients with fulminant hepatitis (FH), five with severe acute hepatitis (AHs) and 13 with self‐limited acute hepatitis (AH), in whom the sequences of all three regions were available, were subjected to phylogenetic analysis.

Results: Fulminant hepatitis patients had fewer nucleotide substitutions in 5′NTR, had a tendency to have more amino acid (aa) substitutions in 2B and had fewer aa substitutions in 2C than AH patients. Four FH and two AHs with a higher viral replication were located in the near parts of the phylogenetic trees, indicating the association between the severity of hepatitis A and genomic variations in 5′NTR, 2B and 2C of HAV.

Conclusions: Our study suggests that genetic variations in HAV not in one specific region but in 5′NTR, 2B and 2C might cooperatively influence replication of the virus, and thereby affect virulence. Viral factors should be considered and examined when discussing the mechanisms responsible for the severity of hepatitis A.
Mycoplasma antigens as a possible trigger for the induction of antimitochondrial antibodies in primary biliary cirrhosis
Authors: Berg Christoph P. , Kannan Thirumalai R. , Klein Reinhild , Gregor Michael , Baseman Joel B. , Wesselborg Sebastian , Lauber Kirsten , Stein Gerburg M.
Published: June 2009

Background: In primary biliary cirrhosis (PBC), autoreactivity mainly targets members of the pyruvate dehydrogenase complex (PDC). Because PDC subunits are expressed on the surface of mycoplasma and molecular mimicry may be one aetiological factor, we analysed the presence of mammalian and mycoplasma PDC‐specific antibodies in PBC patients.

Methods: Antibodies to porcine PDC and Mycoplasma pneumoniae (mp) antigens mpPDH‐C (to be designated mpPDC‐E2 chain), mpPDH‐B (to be designated mpPDC‐E1β chain), mpCARDS TX and mpP1 were investigated in sera from 43 PBC patients, 19 patients with autoimmune hepatitis and 11 healthy controls by an enzyme‐linked immunosorbent assay and Western blotting. To study the rate of acute mycoplasma infection, an adhesin P1‐specific polymerase chain reaction (PCR) was performed.

Results: Immune reactivity to the mpPDC‐E2 antigen was significantly enhanced in PBC patients (83.7%) as compared with controls (overall frequency of 36.7%), while antibodies to the porcine PDC‐E2 chain were found only in PBC patients (88%) excluding a simple cross‐reactivity of PDC‐related antibodies. This observation was confirmed by inhibition studies demonstrating that porcine PDC did not inhibit mycoplasma PDC‐specific antibodies and vice versa. The occurrence of antibodies to mpPDC seems to precede the occurrence of antibodies to porcine PDC. Infection with mycoplasma was equally distributed in the groups as evidenced by an antibody frequency comparable to CARDS TX and P1 and PCR reactivity.

Conclusion: Because PBC patients show a significantly enhanced frequency of mpPDC‐E2‐related antibodies, besides other factors, molecular mimicry between surface molecules of mycoplasma and epitopes of the autoantigen may play a central role in the aetiopathology of PBC.
Albumin‐Coated Amberlite XAD‐7 Resin for Hemoperfusion in Acute Liver Failure: Part II: In Vivo Evaluation
Authors: Hughes Robin , Ton Hsueh Yen , Langley Peter , Davies Michael , Hanid M. Anwar , Mellon Peter , Silk David B. A. , Williams Roger
Published: June 2009

Albumin‐coated Amberlite XAD‐7 has been previously shown to be blood compatible in in vitro hemoperfusion experiments with human blood. In this study, the preliminary results are Reported on single hemoperfusions with albumin‐coated XAD‐7 resin in four patients with acute liver failure. The mean platelet count was 116 ± SE 16.3% of the initial arterial value and the mean white cell count was 96 ± SE 6.5% of initial at the end of four hours of hemoperfusion. Removal of bilirubin, phenols and substances in the middle molecular weight range by the resin was demonstrated.

These preliminary results suggest albumin‐coated Amberlite XAD‐7 resin to be blood compatible and capable of removing protein‐bound and middle molecular weight substances from patients with acute liver failure. Further clinical evaluation of repeated resin hemoperfusion is required to determine whether this treatment will be beneficial to patient survival.
Update on strabismus and amblyopia
Authors: Campos Emilio C.
Published: May 2009

Abstract. This review analyzes progress in the field of infantile strabismus and amblyopia. Only works which are of clinical interest have been reveiwed. A brief survey is provided also of subjects matter of international debate, as surgery for accommodative esotropia, the prism adaptation test and the use of sectors for amblyopia treatment. Mention is made of new developments in the field which are not yet applicable to clinical practice. Finally, progress in the approach towards ocular nystagmus is considered as well.
Cranio‐orbital teratoma
Authors: Prause J. U. , Børgesen S. E. , Carstensen H. , Fledelius H. C. , Jensen O. A. , Kirkegaard J. , Lauersen H. , Naeser P. , Nehen J. H.
Published: May 2009

ABSTRACT A new‐born baby presented with a large, rapidly growing tumour. The tumour involved the right orbit, the anterior half of the right intracranial space and extended through the skull of the temporal region. The proptotic eye ruptured due to exposure. The tumour was extirpated when the patient was 12 days old. A large recurrence was extirpated two months later. The tumour was firmly bound to the medial aspect of the superior orbital fissure which probably was the location of origin of the tumour. Based on the size of the intracranial‐ and the orbital part of the tumour, it was classified as a secondary orbital teratoma. The tumour was macroscopically composed of cystic and solid areas. Microscopically it was seen to be a benign teratoma with tissue from all three germinal layers.
The role of class I and class II HLA antigens in primary open angle glaucoma (POAG)
Authors: Ferreri G. , D'Andrea A. , Castagna I. , Rechichi C. , Pettinato G. , D'Andrea D.
Published: May 2009

Several clinical and epidemiological studies have shown the role of genetic factors in the pathogenesis of primary open angle glaucoma (POAG). In this study, 30 patients affected by this disease were tissue‐typed for HLA Class I and Class II antigens. The results pointed up an increased incidence of some antigens and, particularly, a statistically significant association with DQ1 and DR11 alleles.
SIMULTANEOUS DIRECT DETECTION OF SALMONELLA SPP., LISTERIA MONOCYTOGENES AND ESCHERICHIA COLI O157 IN MILK SAMPLES BY MAGNETIC EXTRACTION AND MULTIPLEX PCR
Authors: OMICCIOLI ENRICA , AMAGLIANI GIULIA , BRANDI GIORGIO , BRUCE IAN J. , MAGNANI MAURO
Published: June 2009

The aim of our work was to develop a new molecular method for the simultaneous detection of Salmonella spp., Listeria monocytogenes and Escherichia coli O157 directly in milk samples.

Three specific target sequences were chosen for a multiplex polymerase chain reaction (PCR) assay: a 155‐bp region of the Salmonella spp. tetrathionate reductase (ttr) locus; a 173‐bp region of the L. monocytogenes listeriolysin O gene (hlyA); a 217‐bp region of the E. coli O157 lipopolysaccharide gene (rfbE). An internal amplification control was also included to detect PCR inhibition. In addition, a magnetic‐based extraction method was also developed to isolate PCR‐ready DNA from milk. The assay was able to detect, whether alone or mixed, also with a difference of 2 log units, as few as 102 cells of each pathogen per 10 mL of spiked milk.

PRACTICAL APPLICATIONS

Escherichia coli O157, Salmonella spp. and Listeria monocytogenes are among the most dangerous foodborne bacterial pathogens in terms of human health and disease, and their detection through current microbiological culture methods involves considerable spending of time and effort. Therefore, the development of rapid and sensitive diagnostic methods is needed. The magnetic DNA extraction proposed in this study concentrates the target organism DNA, removes the inhibitors and presents the additional advantages of being safe and suitable for automation systems. Moreover, the developed multiplex polymerase chain reaction (mPCR) enables the simultaneous detection of more than one target sequence in the same reaction, producing considerable cost and reagent savings. The assay, combining magnetic extraction and mPCR, has proven to be a valuable and cost‐effective tool for monitoring the presence of these pathogens directly in milk samples. Therefore, it could provide a major contribution to efficiency and logistics of molecular diagnostics.
LARGE‐VOLUME FILTRATION FOR RECOVERY AND CONCENTRATION OF ESCHERICHIA COLI O157:H7 FROM GROUND BEEF*
Authors: BREWSTER J.D.
Published: June 2009

Rapid assays for foodborne pathogens currently require an enrichment step to bridge the gap between the detection limit of interest (1 cfu/g or less) and the detection limits of available assay systems (100–100,000 cfu/mL). Although filtration can potentially separate and concentrate bacterial pathogens to detectable levels if large (100–1,000 mL) sample volumes are processed, prior filtration methods failed to approach these volumes because of the high solids content and viscosity of typical food samples. This report describes a novel three‐stage filtration system based on a leukocyte removal filter, a glass fiber prefilter, and a membrane capture filter. Data are presented on factors (e.g., particle size, bacteria binding, pH) affecting filtration performance and protocol design. Escherichia coli O157:H7 at less than 1 cfu/g were quantitatively recovered from 10 g of stomached ground beef in 15 min, and detected on selective media within 24 h.

PRACTICAL APPLICATIONS

The methodology presented in this study allows the rapid concentration of Escherichia coli O157:H7 from the large volumes of stomached ground beef. The primary application is in rapid biosensor detection and quantitation of low levels of pathogens in foods without enrichment. The isolated bacteria can be recovered in a volume of ∼20 µL and are virtually free from interfering sample constituents, allowing facile detection by polymerase chain reaction and other approaches. This filtration methodology may also be useful for studies on attachment and partitioning of bacteria on food surfaces, as free and bound bacteria can be rapidly separated at low concentrations reflecting actual contamination situations.
Demographic Change and Asian Dynamics: Social and Political Implications
Authors: INOGUCHI Takashi
Published: May 2009

This article describes the demographic change and its social and political implications in East and South‐East Asia with a trajectory up to 2050. It selectively touches on inequalities, migration, social policy, and international security. In the course of this exercise, I present two hypotheses: one relating to the formation of the new middle class, and the other relating to the geriatric peace argument. The first hypothesis posits that when the growing inequalities in terms of per capita income aggravate the sense of happiness among the low‐ and middle‐income strata as contrasted to high‐income strata, the formation of a new middle class becomes more difficult. The second hypothesis posits that when the aging population carries a large demographic weight, it tends to be transformed into strong political voice, which is, in turn, translated into larger government spending on social policy items often accompanied by a likely decline in the defense expenditure budget. These hypotheses paint a provocative picture of East and South‐East Asia in the next four decades, especially in the wake of the deepening economic difficulties prevailing over the entire globe. I present these hypotheses for further conceptual elaboration and empirical analysis.
Radiography, computed tomography and virtual bronchoscopy in four dogs and two cats with lung lobe torsion
Authors: Schultz R. M. , Peters J. , Zwingenberger A.
Published: June 2009

This report describes the imaging features of radiography, computed tomography and virtual bronchoscopy in dogs and cats with lung lobe torsions. The medical records, thoracic radiographs and computed tomography images of four dogs and two cats with confirmed lung lobe torsions were retrospectively reviewed. Computed tomography with virtual bronchoscopy showed bronchial narrowing, collapse or occlusion in all six animals, while this was only appreciated on one radiographic examination. A tapering terminating angle of the air‐filled bronchus proximal or distal to the collapsed region was seen only on computed tomography and virtual bronchoscopy in all six animals. The vesicular emphysema pattern typical of lung lobe torsion was seen on three computed tomographies but only on one radiographic examination. The lung lobe torsion‐specific findings of vesicular emphysema and a proximally narrowed or occluded bronchus were more easily recognised on computed tomography and virtual bronchoscopy than with radiographs. Computed tomography slices acquired through the bronchus and lung lobe of interest in a cat or dog with possible lung lobe torsion can be reformatted into virtual bronchoscopic images that can be utilised along with computed tomography to help make a more definitive preoperative diagnosis.
Conserving the zoological resources of Bangladesh under a changing climate
Authors: DAS Bidhan C.
Published: May 2009

It is now well recognized that Bangladesh is one of the world's most vulnerable countries to climate change and sea level rise. Low levels of natural resources and a high occurrence of natural disasters further add to the challenges faced by the country. The impacts of climate change are anticipated to exacerbate these existing stresses and constitute a serious impediment to poverty reduction and economic development. Ecosystems and biodiversity are important key sectors of the economy and natural resources of the country are selected as the most vulnerable to climate change. It is for these reasons that Bangladesh should prepare to conserve its natural resources under changed climatic conditions. Unfortunately, the development of specific strategies and policies to address the effects of climate change on the ecosystem and on biodiversity has not commenced in Bangladesh. Here, I present a detailed review of animal resources of Bangladesh, an outline of the major areas in zoological research to be integrated to adapt to climate change, and identified few components for each of the aforesaid areas in relation to the natural resource conservation and management in the country.
Seasonal and habitat dependence of fleas parasitic on small mammals in Tanzania
Authors: LAUDISOIT Anne , LEIRS Herwig , MAKUNDI Rhodes , KRASNOV Boris Ronald
Published: May 2009

We investigated host and flea species composition across different habitats during dry and rainy seasons in the Western Usambara Mountains in Tanzania. During both seasons, similarity in flea species composition increased with an increase in the similarity in host species composition. Nevertheless, between‐season within‐habitat as well as within‐season between‐habitat similarity in host species composition was higher than similarity in flea species composition. Ordination of habitats according to their host and flea species composition demonstrated that the pattern of between‐habitat similarity in both host and flea species composition varied seasonally. Despite the relatively rich mammal and flea fauna of the study region, the major contribution to variation in species composition between seasons and among habitats was due to a few species only. Flea assemblages on Lophuromys kilonzoi Verheyen et al., 2007 and Praomys delectorum Thomas, 1910 in different habitats were equally similar in either season. In contrast, flea assemblages on Mastomys natalensis (Smith, 1834) occurring in different habitats were more similar in the dry than in the rainy season, whereas the opposite was the case for fleas on Grammomys sp. In different hosts, the main differences in species composition of flea assemblages between seasons as well as among habitats were due to different flea species. Although our results support the earlier idea that parasite species composition is determined by both host species composition and habitat properties, the former appears to explain variance in flea species composition between localities in the tropics better than between localities in temperate and arid zones.
Some like it hot: microclimatic variation affects the abundance and movements of a critically endangered dung beetle
Authors: ROSLIN TOMAS , AVOMAA TIINA , LEONARD MINTTU , LUOTO MISKA , OVASKAINEN OTSO
Published: June 2009

Abstract. 1. Habitat loss and fragmentation is a leading cause of species extinction. This not only concerns loss of major habitats, but also loss of microclimatic heterogeneity within such habitats.

2. In this study, we examine the effects of microclimate on the abundance and movements ofOnthophagus gibbulus, a dung beetle associated with pastoral habitats. While formerly widespread in Southern Finland, the species is now critically endangered at a national level, persisting within an area of 6 km2.

3. We divided the Finnish distribution ofO. gibbulusinto 50 × 50‐m grid cells, characterised local microclimate by incident solar radiation, and surveyed the distribution ofO. gibbuluswithin a subset of cells. To investigate the impact of microclimatic conditions on dung beetle movements, we conducted a mark–release–recapture study.

4. Our approach allowed us to estimate the national population size ofO. gibbulus– a figure rarely available for endangered insect species. The Finnish population ofO. gibbuluscomprises between 2000 and 6000 individuals.

5. The abundance of beetles per dung pat increases with incident solar radiation, and beetles are more likely to move towards warmer than colder spots in the landscape.

6. Overall, our study depictsO. gibbulusas a thermophile confined to the warmest part of the landscape, and offers loss of microclimatic variation as the cause for its large‐scale decline. To conserveO. gibbulusand similar species, we need to consider not only the amount of macrohabitats, but also the amount and distribution of microclimatic variation within them. Future predictions are complicated by ongoing climate change.
On the Teaching of Performance Evaluation and Assessment of a Combined Cycle Cogeneration System
Authors: Arnas A. Özer , Boettner Daisie D. , Norberg Seth A. , Tamm Gunnar , Whipple Jason R.
Published: May 2009

Performance evaluation and assessment of combined cycle cogeneration systems are not taught well in academia. One reason is these parameters are scattered in the literature with each publication starting and ending at different stages. In many institutions professors do not discuss or even mention these topics, particularly from a second law perspective. When teaching combined cycle cogeneration systems to undergraduates, the professor should introduce pertinent parameters in a systematic fashion and discuss the usefulness and limitations of each parameter. Ultimately for a given situation, the student should be able to determine which parameters form the most appropriate basis for comparison when considering alternative designs. This paper provides two approaches, one based on energy (the first law of thermodynamics) and the other based on exergy (the second law of thermodynamics). These approaches are discussed with emphasis on the “precise” teaching of the subject matter to undergraduates. The intent is to make coverage of the combined cycle cogeneration systems manageable so that professors can appropriately incorporate the topic into the curricula with relative ease.
Thermal Design of Microchannel Heat Sinks for Low-Orbit Micro-Satellites
Authors: Heresztyn Amaury J. H. , DeJong Okamoto Nicole C.
Published: May 2009

As reduction in the size of electronics creates demand for smaller, less expensive and faster-to-produce spacecraft, the use of high heat flux electronics or advanced nuclear propulsion systems will increase the stress on the thermal subsystem. This work presents a thermal management solution to this problem using liquid-cooled microchannel heat sinks. First, a simple computer model is used to illustrate the need for an atypical cooling method when high-heat flux electronics are used. Second, a thermal/fluid model of microchannel heat sinks is developed and applied to address the satellite thermal need. The total thermal resistances and pressure drops show excellent comparison with published experimental and analytical results. Finally, the model of the microchannel heat sink is optimized to remove 25 W/cm2 over a footprint of 3.7cm2. The mass flow rate needed was significantly lower (almost 5–10 times lower) when compared to other published results, which means that micro-pumps available on the market will be sufficient. The integration of the microchannel system with the satellite is also discussed.
Experimental Study of Capillary Pumping During Vaporization in a Square Cross Section Microchannel
Authors: Serin Vale´rie , Lavieille Pascal , Miscevic Marc
Published: May 2009

An experimental study is undertaken to investigate microcapillary pumped loop (micro-CPL) evaporator behaviours. The experimental set-up is made of a horizontal square cross section glass microchannel which is locally heated up in order to analyze vaporization. A specific procedure allowed us to investigate the capillary pumping due to vaporization: the mass flow rate according to heat flux applied is determined. A laser-induced fluorescence technique has been used to observe phases distribution in the microchannel during vaporization, especially the liquid raising in the corners. The extended meniscus zone length has been determined as a function of the heat flux using image processing.
A-Posteriori Finite Element Bound and Adaptive Discretization Methods for the Electro-Osmotic Flows in Heterogeneous Microchannels
Authors: Choi Hae-Won , Paraschivoiu Marius
Published: May 2009

Numerical simulation based a design tool devised by an aposteriori error estimation technique termed the ‘bound method’ is applied in this paper to examine and analyze fluidic flow and species transport phenomena of the electro-osmotic flow in a heterogeneously charged T-shaped micro-mixer. This novel technique provides fast, inexpensive and reliable bounds to the ‘output’ for the slip velocity model of the electro-osmotic flow. The bound method presented here-in is extended to use of an adaptive refinement to generate the ‘ideal’ mesh for computations, the direct equilibration to evaluate the ‘hybrid-flux’ very efficiently, and a parallel calculation to accelerate the error estimates of the output of interest.
Single-Phase Liquid Heat Transfer in Microchannels
Authors: Steinke Mark E. , Kandlikar Satish G.
Published: May 2009

The development of advanced microchannel heat exchangers and microfluidic devices is dependent upon the understanding of the fundamental heat transfer processes that occur in these systems. Several researchers have reported significant deviation from the classical theory used in macroscale applications, while others have reported general agreement, especially in the laminar region. This fundamental question needs to be addressed in order to generate a set of design equations to predict the heat transfer performance of microchannel flow devices. A database is generated from the available literature to critically evaluate the reported experimental data. An in-depth comparison of previous experimental data is performed to identify the discrepancies in the reported literature. It is concluded that the classical theory is applicable to microchannel and minichannel flows. The literature reporting discrepancies do not account for developing flows, fin efficiency, erros in channel geometry measurements and experimental uncertainties. It is further concluded that if all these factors are accounted for, the available data have good general agreement with macroscale theories. A similar approach is presented for pressure drop in microchannels in an accompanying conference paper, Steinke and Kandlikar (2005).
Self-Breakup of Microdroplets by Molecular Self-Assembly
Authors: Mo Gary C. H. , Kwok Daniel Y.
Published: May 2009

We report a method of producing minute micro-droplets through nanoscale molecular self-assembly from a given liquid volume without external input. By the branching of hydrophobic restrictions, the drop is forced to separate while translating on a flat surface. Symmetry in the drop front wetted perimeter conduces to equal division of the drop. We show that at least 3 divisions can be performed sequentially on a 1.5 microliter drop to give minute droplets of approximately equal volumes. A division of carrier liquid volume by 1/23 enables multiple analyses on many separate stations in one microfluidic application.
Fabrication of Polymeric Microfluidic Device for On-Chip Isolation of Nucleic Acids
Authors: Bhattacharyya Arpita , Klapperich Catherine
Published: May 2009

A microfluidic chip-based solid phase extraction method for isolation of nucleic acids is demonstrated. The chip was fabricated in a cyclic polyolefin by hot embossing with a master. The solid phase was made by in-situ UV polymerization of a monolithic column impregnated with silica particles, and separation was achieved due to irreversible binding of the nucleic acids to the silica particles in the monolith. The porous monolithic column was formed within the channels of the device by photoinitiated polymerization of a mixture of methacrylate and dimethacrylate monomers, UV sensitive free radical initiator and porogenic solvent. The channel surface was photografted with a thin interlayer polymer prior to preparation of the monolith in the channel. The grafted layer covalently attached the monolith and prevented the formation of voids between the monolith and the channel surface. The solid-phase prepared by this method allowed for successful extraction and elution of nucleic acids.
Microbubble Emission Boiling in a Rectangular Channel Flow
Authors: Tange Manabu , Watanabe Makoto , Takagi Shu , Takemura Fumio , Shoji Masahiro
Published: May 2009

Highly subcooled flow boiling at high heat flux in a rectangular minichannel of 2 mm × 2 mm in dimension was experimentally investigated. The channel was heated only from the bottom wall of the channel and it is regarded as a model of cooling components on electric devices in mobile gears. Under the condition of high subcooling and high heat flux in the stagnant pool and conventional scale channel flow, many fine vapor bubbles are emitted from primary vapor bubbles on heated surfaces. This boiling regime is called microbubble emission boiling (MEB). If we realize MEB in a minichannel, high heat flux due to vaporization will be obtained and large pressure loss due to confinement of bubble will be avoided. This paper first reports the results of our early experimental investigations on MEB in a pool boiling system to introduce the appearance of MEB. In flow boiling experiment, we reports heat transfer characteristics and photographic observation.
An approach to using conventional brachytherapy software for clinical treatment planning of complex, Monte Carlo‐based brachytherapy dose distributionsa)
Authors: Rivard Mark J. , Melhus Christopher S. , Granero Domingo , Perez‐Calatayud Jose , Ballester Facundo
Published: May 2009

Certain brachytherapy dose distributions, such as those for LDR prostate implants, are readily modeled by treatment planning systems (TPS) that use the superposition principle of individual seed dose distributions to calculate the total dose distribution. However, dose distributions for brachytherapy treatments using high‐ shields or having significant material heterogeneities are not currently well modeled using conventional TPS. The purpose of this study is to establish a new treatment planning technique (Tufts technique) that could be applied in some clinical situations where the conventional approach is not acceptable and dose distributions present cylindrical symmetry. Dose distributions from complex brachytherapy source configurations determined with Monte Carlo methods were used as input data. These source distributions included the 2 and 3 cm diameter Valencia skin applicators from Nucletron, 4–8 cm diameter AccuBoost peripheral breast brachytherapy applicators from Advanced Radiation Therapy, and a 16 mm COMS‐based eye plaque using , , and seeds. Radial dose functions and 2D anisotropy functions were obtained by positioning the coordinate system origin along the dose distribution cylindrical axis of symmetry. Origin:tissue distance and active length were chosen to minimize TPS interpolation errors. Dosimetry parameters were entered into the PINNACLE TPS, and dose distributions were subsequently calculated and compared to the original Monte Carlo‐derived dose distributions. The new planning technique was able to reproduce brachytherapy dose distributions for all three applicator types, producing dosimetric agreement typically within 2% when compared with Monte Carlo‐derived dose distributions. Agreement between Monte Carlo‐derived and planned dose distributions improved as the spatial resolution of the fitted dosimetry parameters improved. For agreement within 5% throughout the clinical volume, spatial resolution of dosimetry parameter data was required, and the virtual brachytherapy source data set included over 5000 data points. On the other hand, the lack of consideration for applicator heterogeneity effect caused conventional dose overestimates exceeding an order of magnitude in regions of clinical interest. This approach is rationalized by the improved dose estimates. In conclusion, a new technique was developed to incorporate complex Monte Carlo‐based brachytherapy dose distributions into conventional TPS. These results are generalizable to other brachytherapy source types and other TPS.
Photon beam dosimetry in the superficial buildup region using radiochromic EBT film stack
Authors: Chiu‐Tsao Sou‐Tung , Chan Maria F.
Published: May 2009

It has been a challenge to perform accurate 2D or 3D dosimetry in the surface region with steep dose gradient for megavoltage photon beams. We developed a dosimetry method in the superficial buildup region for the 6 and 15 MV photon beams using a radiochromic EBT film stack. Eight radiochromic EBT film strips stacked together formed a 3D dosimeter. The film stack was positioned above a polystyrene phantom and surrounded by Solid Water slabs (0.2 cm) with the top film layer at 100 cm SSD. A open field was used to irradiate the film stack with 1000 MU. All films were scanned using Epson 4870 flatbed scanner with transmission mode, 48 bit color, and 150 dpi (0.017 cm pixel resolution). The pixel values were converted to doses using an established calibration curve. This method allowed dose measurement for depths from 0.012 to 0.18 cm with fine spatial resolution (0.017 cm horizontally and 0.024 cm vertically). For each energy modality, we obtained both the central axis percent depth doses and the beam profiles along the central line covering the primary field and peripheral region at each depth. The primary field doses varied steeply with depth, while those in the peripheral region were weakly dependent on depth. For the 6 MV and 15 MV photon beams, (1) the central axis percent depth doses in the eight film layers ranged from 22% to 66% and from 15% to 44%, respectively; (2) the extrapolated percent depth doses at were 15% and 14%, respectively. Agreement with the previously reported central axis percent depth doses in this region using parallel plate thin window ion chamber and ultrathin TLD was observed. The percent depth doses and beam profiles data can be incorporated in the treatment planning system for more accurate assessment of the doses to skin and shallow tumors to accomplish more accurate calculation results in the clinical usage.
The evolution of brachytherapy treatment planning
Authors: Rivard Mark J. , Venselaar Jack L. M. , Beaulieu Luc
Published: May 2009

Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer‐based dose‐calculation algorithms. The current approach is based on the AAPM TG‐43 formalism with recent advances in acquiring single‐source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose‐calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose‐calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.
Angular dependence of dose sensitivity of surface diodes
Authors: Jursinic Paul A.
Published: May 2009

Commercially available surface diodes are found to have as great as ±12% change in sensitivity with the angle of incidence of radiation. This work is a study of the cause of angular dependence in diode sensitivity and how it can be decreased. A number of different surface diodes were used in these measurements: A commercially available diode and four prototype diodes. A number of the diodes were constructed with the silicon chip, the die, mounted on a circuit board that had a plane of copper on its back side. These diodes had angular dependence of sensitivity as great as ±10%. It was hypothesized that the copper plane on the circuit board was the cause of the anisotropy in sensitivity of the diodes. To test this hypothesis, diodes with a new design [Patent No. 61/035,257 (pending)], without a copper back plane, were fabricated and characterized in this work. These diodes were found to have the following characteristics: A dependence on incident angle of radiation of ±3.6%; after 10 kGy of pre‐irradiation, a 1.6% change in sensitivity for a 260‐fold change in dose per pulse; an areal density of .
Dosimetric characterization and application of an imaging beam line with a carbon electron target for megavoltage cone beam computed tomography
Authors: Flynn Ryan T. , Hartmann Julia , Bani‐Hashemi Ali , Nixon Earl , Alfredo R. , Siochi C. , Pennington Edward C. , Bayouth John E.
Published: May 2009

Imaging dose from megavoltage cone beam computed tomography (MVCBCT) can be significantly reduced without loss of image quality by using an imaging beam line (IBL), with no flattening filter and a carbon, rather than tungsten, electron target. The IBL produces a greater keV‐range x‐ray fluence than the treatment beam line (TBL), which results in a more optimal detector response. The IBL imaging dose is not necessarily negligible, however. In this work an IBL was dosimetrically modeled with the Philips treatment planning system (TPS), verified experimentally, and applied to clinical cases. The IBL acquisition dose for a 200° gantry rotation was verified in a customized acrylic cylindrical phantom at multiple imaging field sizes with 196 ion chamber measurements. Agreement between the measured and calculated IBL dose was quantified with the 3D index. Representative IBL and TBL imaging dose distributions were calculated for head and neck and prostate patients and included in treatment plans using the imaging dose incorporation (IDI) method. Surface dose was measured for the TBL and IBL for four head and neck cancer patients with MOSFETs. The IBL model, when compared to the percentage depth dose and profile measurements, had 97% passing indices for dosimetric and distance acceptance criteria of 3%, , and 100% passed for 5.2%, . For the ion chamber measurements of phantom image acquisition dose, the IBL model had 93% passing indices for acceptance criteria of 3%, , and 100% passed for 4%, . Differences between the IBL‐ and TBL‐based IMRT treatment plans created with the IDI method were dosimetrically insignificant for both the prostate and head and neck cases. For IBL and TBL beams with monitor unit values that would result in the delivery of the same dose to the depth of maximum dose under standard calibration conditions, the IBL imaging surface dose was higher than the TBL imaging surface dose by an average of 18%, with a standard deviation of 8% . The IBL can be modeled with acceptable accuracy using a standard TPS, and accounting for IBL dose in treatment plans with the IDI method is straightforward. The resulting composite dose distributions, assuming similar imaging doses, are negligibly different from those of the TBL. The increased IBL surface dose relative to the TBL is likely clinically insignificant.
Structure and Mechanism of an Amino Acid Antiporter
Authors: Gao Xiang , Lu Feiran , Zhou Lijun , Dang Shangyu , Sun Linfeng , Li Xiaochun , Wang Jiawei , Shi Yigong
Published: May 2009

Antiporter Antics

Bacteria that survive in the acidic environment of the stomach have mechanisms to maintain a high intracellular pH. In
Escherichia coli
, glutamate (Glu) and arginine (Arg) are decarboxylated intracellularly and the reaction products are exchanged with extracellular Glu and Arg.

Gao
et al.

(p.
1565
, published online 28 May) now report a crystal structure of AdiC, an arginine:agmatine antiporter from
E. coli
. AdiC exhibits the same fold as that of the Na
+
-coupled symporters, including LeuT. It contains 12 transmembrane segments, forms a homodimer, and exists in an outward-facing, open conformation in the crystals. The structure, together with biochemical data, suggests how the antiporter senses the pH and responds to transport the reaction product agmatine out of the cell and Arg into the cell.
Neuroanatomical Basis of Acupuncture Treatment for Some Common Illnesses
Authors: Cheng Kwokming James
Published: June 2009

The acupuncture treatment formulae for some common conditions are reviewed. These conditions include low back pain, sciatica, trigeminal neuralgia, facial nerve palsy, asthma, nausea and vomiting, gastritis and dysmenorrhoea. It is found that in many cases, the acupuncture points traditionally used for the treatment have a neuroanatomical significance from the viewpoint of Western medicine. And from that one can hypothesise a plausible mechanism of action as to how acupuncture achieves its therapeutic effects in terms of contemporary Western medicine. These mechanisms of action include intramuscular stimulation for treating muscular pain and nerve stimulation for treating neuropathies. The sympathetic ganglion may be involved in the acupuncture treatment of asthma. Somato-autonomic reflex may be responsible for the acupuncture effect on gastritis.
Medical students’ attitudes to abortion: a comparison between Queen’s University Belfast and the University of Oslo
Authors: Steele R
Published: May 2009

Background:

Abortion policy varies significantly between Northern Ireland and Norway. This is the first study to compare medical students’ attitudes towards abortion in two different countries.

Objective:

To assess medical students’ attitudes to abortion at the University of Oslo (UiO) and Queen’s University Belfast (QUB).

Design:

An anonymous questionnaire completed by 59 medical students at UiO and 86 medical students at QUB.

Participants:

Students who had completed their obstetrics and gynaecology placements during 2006/2007.

Results:

The students’ responses (UiO versus QUB) were as follows: response rate, 95.2% vs 92.5%; stated no religious affiliation, 48.0% vs 4.7%; pro-abortion, 78.2% vs 14.3% (χ2 = 58.160, p<0.001); had seen an abortion while studying medicine, 74.6% vs 9.4% (χ2 = 73.183, p<0.001); in favour of abortion when there was a threat to the mother’s life, 100% vs 93.3% (χ2 = 6.143, p = 0.150); in favour of providing abortion on the mother’s request, 86.4% vs 9.3% (χ2 = 42.067, p<0.001); in agreement that women should have access to free abortion services (mean value on a 5-point Likert scale 1.69 out of 5), versus in disagreement (mean 3.76, p<0.001).

Conclusion:

There were significant differences in students’ attitudes to abortion, reflecting differences in religious, legal and educational experiences.
Overlap of premature birth and permissible abortion
Authors: Collyns O , Gillett G , Darlow B
Published: May 2009

Abortion is permitted in many jurisdictions after the age at which an infant is viable on the basis of intensive neonatal care techniques. Does this cause special concerns for those involved in perinatal care and termination of pregnancy services or is the overlap mainly an abstract issue fretted over by ethicists and academics? In order to explore this question, a group of clinicians involved in this area of care were interviewed and their interviews analysed using qualitative measures. The clinicians concerned were exercised by the ethical issues and had various ways of resolving them which tended to reflect a gradualist, multifaceted and, to some extent, particularist approach to ethical decision-making in relation to the edges of human life. The ways in which those strands of ethical thought are instanced in the interview material are reported and discussed.
Selection for low erucic acid and genetic mapping of loci affecting the accumulation of very long-chain fatty acids in meadowfoam seed storage lipids
Authors: Gandhi S. D. , Kishore V. K. , Crane J. M. , Slabaugh M. B. , Knapp S. J.
Published: May 2009

Erucic acid (22:113) has been identified as an anti-nutritional compound in meadowfoam ( Limnanthes alba ) and other oilseeds in the Brassicales, a classification which has necessitated the development of low erucic acid cultivars for human consumption. The erucic acid concentrations of meadowfoam wild types (8%–24%) surpass industry standards for human consumption (≤3%). The goals of the present study were to develop low erucic acid lines and identify loci affecting the accumulation of 22:113and other very long-chain fatty acids (VLCFAs) in meadowfoam seed storage lipids. LE76, a low erucic acid line, was developed by 3 cycles of selection in an ethyl methanesulfonate–treated wildtype population. LE76 produced 3% 22:113, threefold less than the M0population. Wildtype × LE76 F2populations produced continuous, approximately normal erucic and dienoic acid distributions. Loss-of-function mutations apparently did not segregate and individuals with low 22:113concentrations (≤3%) were observed only in F2populations from hybrids with L. alba subsp. alba wild types. The meadowfoam genome was mapped and scanned for quantitative trait loci (QTL) affecting VLCFA profiles in seed storage lipids by genotyping and phenotyping wildtype × low erucic acid F2progeny. Composite interval mapping identified 3 moderately large-effect erucic acid QTL. The low erucic acid parent transmitted favorable alleles for 2 of 3 QTL, suggesting low erucic acid cultivars can be developed by combining favorable alleles transmitted by wildtype and low erucic acid parents.
Rapid development of PCR-based genome-specific repetitive DNA junction markers in wheat
Authors: Wanjugi Humphrey , Coleman-Derr Devin , Huo Naxin , Kianian Shahryar F. , Luo Ming-Cheng , Wu Jiajie , Anderson Olin , Gu Yong Qiang
Published: May 2009

In hexaploid wheat ( Triticum aestivum L.) (AABBDD, C = 17 000 Mb), repeat DNA accounts for ∼90% of the genome, of which transposable elements (TEs) constitute 60%–80%. Despite the dynamic evolution of TEs, our previous study indicated that the majority of TEs are conserved and collinear between the homologous wheat genomes, based on identical insertion patterns. In this study, we exploited the unique and abundant TE insertion junction regions identified from diploid Aegilops tauschii to develop genome-specific repeat DNA junction markers (RJM) for use in hexaploid wheat. In this study, both BAC end and random shotgun sequences were used to search for RJM. Of the 300 RJM primer pairs tested, 269 (90%) amplified single bands from diploid Ae. tauschii. Of these 269 primer pairs, 260 (97%) amplified hexaploid wheat and 9 (3%) amplified Ae. tauschii only. Among the RJM primers that amplified hexaploid wheat, 88% were successfully assigned to individual chromosomes of the hexaploid D genome. Among the 38 RJM primers mapped on chromosome 6D, 31 (82%) were unambiguously mapped to delineated bins of the chromosome using various wheat deletion lines. Our results suggest that the unique RJM derived from the diploid D genome could facilitate genetic, physical, and radiation mapping of the hexaploid wheat D genome.