bluuebunny/crossref_metadata_2025 huggingface dataset:
18F-FDG-PET and MRI in patients with malignancies of the liver and pancreas
Authors: Reiner C. S. , Hany T. F. , Fornaro J. , von Schulthess G. K. , Marincek B. , Weishaupt D. , Donati O. F.
Published: April 2010

Purpose: To evaluate the accuracy of retrospective rigid image registration and fusion between F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI) of the upper abdomen. Patients, material, methods: Image fusion of PET and MRI was performed in 30 patients with suspected malignancy of the liver or pancreas. Using a commercially available image fusion tool capable of rigid manual point-based registration, PET-Images were retrospectively registered and fused by matching eight homologous points in the 3D spoiled gradient echo (GRE) MRI sequences acquired in portal venous phase and in the CT-component of PET/CT. Two separate observers (R1, R2) assessed accuracy of image registration by determining the distances in the x-, y- and z-axis as well as the absolute distance between anatomical landmarks which differed from the landmarks chosen for registration. Quality of fusion was graded using a three point grading scale (1 poorly fused; 2 satisfactory fused; 3 correctly fused) and compared to hybrid PET/CT fusion. Results: Mean time of registration per patient was less than 2 minutes. Objective registration assessment showed errors between 2.4–6.3 mm in x-axis: mean 3.6 mm (R1); 4.6 mm (R2), 2.3–9.3 mm in y-axis (mean 5.1 mm; 5.5 mm) and 3.3–12.0 mm in z-axis (mean 5.9 mm; 5.9 mm.) The mean error in absolute distance between points was 6.0–16.8 mm (mean 9.9 mm; 10.6 mm). In visual assessment, most fusions were graded to be satisfactory or correctly fused: R1, R2: grade 3, 11/30 (36.7%), 22/30 (73.3%); grade 2, 13/30 (43.3%), 8/30 (26.7%); grade 1, 6/30 (20%), 0/30 (0%). Fusions were mostly comparable to hybrid PET/ CT fusions. All of the fusions were defined as diagnostically relevant by both observers. Conclusion: Retrospective rigid image fusion of FDGPET and MRI of the upper abdomen using the CT-component of PET/CT for registration is feasible without adaptation in image acquisition protocols and shows sub-centimeter registration errors in most cases.
Analysis of 18F-FDG uptake pattern in PET for diagnosis of aseptic loosening versus prosthesis infection after total knee arthroplasty
Authors: Gebhard M. , Ackermann D. , Büll U. , Hermanns-Sachweh B. , Mumme T. , Gravius S.
Published: April 2010

The aim of this prospective study was to identify a typical pattern for fluorodeoxyglucose (18F-FDG) uptake in positron emission tomography (PET) to differentiate aseptic loosening (tibial and / or femoral component) from prosthesis infection in painful knee prosthesis. Patients, methods: 20 patients with painful knee prosthesis underwent PET imaging to evaluate aseptic loosening / prosthesis infection of their knee prosthesis. The interface between bone and surrounding soft tissue or bone was divided into 3 segments each for both the femur and the tibia and in addition for 4 segments reflecting the surrounding periprosthetic soft tissue. FDG uptake in each of the segments was scored (0–3) by two independent observers. The final diagnosis was based on operative findings with subsequent microbiological culture and histological examination. Results: After surgical revision 6 femoral components and 5 tibial components were found to be loose and prosthetic infection was present in 9 prostheses. In 8 of 9 infected prostheses loosening of the femoral und tibial component occurred. There was no statistically significant correlation between the standardised uptake within each of the segments and the diagnosis of aseptic loosening or prosthesis infection. A differentiated qualitative and quantitative FDG-PET result interpretation divided into five categories was developed. Specificity / sensitivity / positive predictive value / negative predictive value were 93% / 83% / 83% / 93% for aseptic loosening of the femoral component, 87% / 80% / 67% / 93% for aseptic loosening of the tibial component and 82% / 89% / 80% / 90% for infection. Conclusion: This pilot study shows that FDG-PET is a promising diagnostic tool for patients with painful knee prostheses. There is a good correlation between PET images and the intraoperative and pathology findings. Its clinical value, however, warrants further evaluation in a larger patient population.
INVESTIGATION INTO MARINE TRAFFIC AND A RISKY AREA IN THE TURKISH STRAITS SYSTEM: CANAKKALE STRAIT
Authors: Basar Ersan
Published: April 2010

The Turkish Straits comprising the Strait of Canakkale, the Strait of Istanbul and the Sea of Marmara are unique in many respects. All dangers and obstacles characteristic of narrow waterways are present and acute in this critical sea lane. This research reveals the simulation of Canakkale (Dardanelle) Strait under different traffic conditions and identifies risky areas. The results of this simulation show that an increase of 25% in the existing traffic grows 43 times in the number of waiting ships (from 1.663 to 73.73), whereas waiting time increases 29 times (from 24.267 to 737.07). As a result of simulations and risk analysis, it is found that Nara turning point is the bottleneck point of the strait due to its topographic structure and the current system.
CHOOSING RAILWAY VEHICLES FOR CARRYING PASSENGERS
Authors: Dailydka Stasys
Published: April 2010

To carry passengers, diesel and electrical trains, railcars, passenger carriages and hauled locomotives are used in AB ‘Lietuvos geležinkeliai’ (Lithuanian Railways). In certain sections, the number of passengers is very low (e.g. several or up to twenty passengers per 24 hours), and therefore rolling stock is used inefficiently. For this reason, it is necessary to optimize the choice of vehicles on different routes taking into account the possibilities of their application and fluctuations in the number of passengers. To this end, a mathematical model has to be developed which would allow selecting an efficient means for carrying passengers in each case and, if required, to choose rational routes by applying the above introduced model.
THE STEEPNESS OF THE RISING BRANCH OF ADHESIVE CHARACTERISTICS BETWEEN WHEEL AND RAIL
Authors: Lata Michael , Čáp Jaroslav
Published: April 2010

The article describes the limiting parameters of the rising branch of adhesive characteristics. Attention is paid to the actual results of experimental research conducted by the authors. A summary of the obtained knowledge is made. In addition, a test stand of tram wheels driven by the synchronous motor and the carried out experiments are described. A comparison of the achieved results is drawn.
A FUZZY MODEL FOR AN INCREASE IN LOCOMOTIVE TRACTION FORCE
Authors: Djukić Marko , Rusov Srdjan , Mitrović Zoran
Published: April 2010

This paper deals with the process of traction force realization described by a suitable mechanical model and is pointed to the adhesion phenomenon as a physical one, i.e. is a suitable factor that the value of traction force depends on. The model for the process of optimizing locomotive traction force based on using the fuzzy set theory is explained. The projecting process of a fuzzy controller regulating the value of skidding and the value of traction torque by increasing the value of traction force that can be realized according to adhesion conditions is described. Finally, testing the optimization model in several numerical examples under specific conditions of wheel-rail adhesion is done.
INVESTIGATION ON TRANSPORT RELATED BIOGAS UTILIZATION
Authors: Kovács Viktória Barbara , Török Ádám
Published: April 2010

Due to an increase in demand for energy and the mobility of the human population as well as in order to keep sustainable development, there is a major need to utilize alternative energy sources. The use of biogases as a source of renewable energy could provide an effective and alternative way to fulfil a remarkable part of this demand for energy. As biogases have high inert content, their heating value is low. The energetic utilization of these low heating value renewable gaseous fuels is not fully worked out yet because their combustion characteristics significantly differ from the liquid fuels that are used nowadays in transportation, and in this way, they are not usable or their utilization is limited in devices with conventional equipment. Thus, theoretical and experimental analysis was made to investigate the usability of biogases.
COMPARABLE ANALYSIS OF INFORMATION AND COMMUNICATION TECHNOLOGIES IN LITHUANIA AND FINLAND
Authors: Bazaras Darius , Ledauskaitė Kristina , Palšaitis Ramūnas
Published: April 2010

Information exchange and making business transactions via the Internet and E-mail are very common nowadays. Thus, it is very important to investigate the use of applied Information and Communication Technologies (ICT) in activities undertaken by business and transport companies examining the levels the companies are making investments and to assess needs for a wider use of ICT in the logistics and transport companies. A number of authors in the Baltic States are analyzing ICT in separate business areas, for example transportation, warehousing, marketing, management etc. but none of those analyzes the use and development of ICT inside the company. The article describes the situation of using and developing ICT in the Baltic Sea Region and makes a comparison of Lithuanian and Finnish companies. Finland was chosen for benchmarking because research on ICT in the Baltic Sea Region (BSR) showed that the situation of using ICT in Lithuania and its neighborhood countries was similar.
Temporizing External Fixation of the Lower Extremity: A Survey of the Orthopaedic Trauma Association Membership
Authors: Collinge Cory , Kennedy Jason , Schmidt Andrew
Published: April 2010

This study examined the opinions of practicing traumatologists to aid in the initial treatment of complicated lower extremity fractures in accordance with current staged protocols. A 40-question online survey of the Orthopaedic Trauma Association (OTA) membership was administered from November 2008 to February 2009. The survey investigated surgeons' preferences regarding general principles and routine management of joint-spanning lower extremity external fixators, as well as favored knee- and ankle-spanning constructs and conditions of definitive surgical reconstruction. Data were collected using a 5-point Likert scale ranging from strongly agree (5) to strongly disagree (1). Responses were given numerical weight in descending order (scoring 5-1) and were reported as straight percentages and with a weighted mean called the rating average.

Responses were received from half of the OTA membership. Among the strongest preferences (rating average >4) were for obtaining a computed tomography (CT) scan as part of prereconstruction planning (4.8) and obtaining that CT scan after joint-spanning external fixation was applied (4.6). Restoration of length as the most important part of limb realignment at the time of temporizing external fixator application (4.3), the use of soft tissue protection during pin application (4.4), and avoiding overlap of pin sites with a plate at the time of reconstruction (4.3) were highly favored. Survey respondents treated a sizable volume of periarticular lower extremity injuries with temporizing external fixation and staged reconstruction. This consolidation of trends and preferences for constructing and using temporizing external fixation for complex lower extremity injuries hopefully will aid in the treatment of these difficult fractures.
First North American records forHeterarthrus vagans(Hymenoptera: Tenthredinidae), a Palaearctic leafmining sawfly of alder
Authors: Humble Leland M.
Published: April 2010

The discovery in southwestern British Columbia of widespread established populations of the Palaearctic leafminerHeterarthrus vagans(Fallén) feeding on native red alder,Alnus rubraBong. (Betulaceae), is reported. A preliminary survey suggests that it is currently confined to the Fraser Valley west of Hope, its distribution extending north along Howe Sound almost to Squamish. It was not found in the greater Victoria area. No other regions of the province have been surveyed. This introduced sawfly completes at least two generations a year. Diagnostic characters to aid the recognition of adults and feeding larvae ofH. vagansand a modified key to adult Heterarthrinae on Betulaceae are provided.
IgM, FcμRs, and Malarial Immune Evasion
Authors: Czajkowsky Daniel M. , Salanti Ali , Ditlev Sisse B. , Shao Zhifeng , Ghumra Ashfaq , Rowe J. Alexandra , Pleass Richard J.
Published: April 2010

IgM is an ancestral Ab class found in all jawed vertebrates, from sharks to mammals. This ancient ancestry is shared by malaria parasites (genus Plasmodium) that infect all classes of terrestrial vertebrates with whom they coevolved. IgM, the least studied and most enigmatic of the vertebrate Igs, was recently shown to form an intimate relationship with the malaria parasite Plasmodium falciparum. In this article, we discuss how this association might have come about, building on the recently determined structure of the human IgM pentamer, and how this interaction could affect parasite survival, particularly in light of the just-discovered FcμR localized to B and T cell surfaces. Because this parasite may exploit an interaction with IgM to limit immune detection, as well as to manipulate the immune response when detected, a better understanding of this association may prove critical for the development of improved vaccines or vaccination strategies.
Paradigm Shift or Annoying Distraction
Authors: O’Donnell J. , Clayton M. , Anderson P. , Krueger A. , Spallek H.
Published: April 2010

Web 2.0 technologies, known as social media, social technologies or Web 2.0, have emerged into the mainstream. As they grow, these new technologies have the opportunity to influence the methods and procedures of many fields. This paper focuses on the clinical implications of the growing Web 2.0 technologies. Five developing trends are explored: information channels, augmented reality, location-based mobile social computing, virtual worlds and serious gaming, and collaborative research networks. Each trend is discussed based on their utilization and pattern of use by healthcare providers or healthcare organizations. In addition to explorative research for each trend, a vignette is presented which provides a future example of adoption. Lastly each trend lists several research challenge questions for applied clinical informatics.

Citation: Spallek H, O’Donnell J, Clayton M, Anderson P, Krueger A. Paradigm shift or annoying distraction – emerging implications of Web 2.0 for clinical practice. Appl Clin Inf 2010; 1: 96–115 http://dx.doi.org/10.4338/ACI-2010-01-CR-0003
Antibiotic‐Loaded PLGA Nanofibers for Wound Healing Applications
Authors: Soscia David A. , Raof Nurazhani Abdul , Xie Yubing , Cady Nathaniel C. , Gadre Anand P.
Published: April 2010

Incorporating antibiotics into biocompatible nanoscale non‐woven fibrous mats could provide utility for wound healing applications and for incorporation into wound dressing materials. In this study, the antibiotic chloramphenicol (Cm) was incorporated into electrospun poly(lactic‐co‐glycolic acid) (PLGA) nanofibers, which were then tested for inhibition of bacterial growth for multiple bacterial species (Escherichia coli, Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium, and Pseudomonas aeruginosa). In addition, the cytotoxicity of Cm‐PLGA nanofibers was examined for two types of mammalian cells including mouse embryonic stem cells and fibroblasts. Electrospun PLGA nanofibers containing Cm were able to reduce bacterial growth on solid agar plates for all species except for P. aeruginosa. In liquid culture, Cm‐loaded nanofibers inhibited growth for E. coli, B. cereus and S. typhimurium by 93% or greater, while P. aeruginosa and S. aureus growth was inhibited by 42% and 56%, respectively. Cm‐loaded nanofibers showed limited cytoxicity on fibroblasts and embryonic stem cells, with viability greater than 96% for all conditions tested. These results suggest that Cm can be successfully incorporated into electrospun nanofibers and that these fibers could be used for wound healing applications with minimal cytotoxicity to the surrounding tissue.
Synthesis of Highly Fluorescent and Soluble 1,2,4‐Linking Hyperbranched Poly(arylenevinylene) Featuring Intramolecular Energy Funneling
Authors: Xie Zengqi , Yoon Seong‐Jun , Park Soo Young
Published: April 2010

The synthesis and optical properties of a highly soluble (>200 mg mL−1) and highly fluorescent (ΦF in film = 0.64) 1,2,4‐linking hyperbranched poly(arylenevinylene) (1,2,4‐hb‐PAV) prepared via Wittig reaction of A3 (biphenyl‐tricarbaldehyde) and B2 (phosphonium salt) monomers is reported. The molecular weight of 1,2,4‐hb‐PAV can be precisely controlled by the amount of the base (NaOCH3) used in the polymerization. The absorption and photoluminescence (PL) spectra of 1,2,4‐hb‐PAV shows distinct red‐shifts compared to conventional 1,3,5‐linking hyperbranched poly(arylenevinylene) (1,3,5‐hb‐PAV), attributed to the extended π‐conjugation along ortho‐ (1,2‐) and para‐ (1,4‐) links. The inherent energy gradient from the shorter branches to the longer conjugated stem in 1,2,4‐hb‐PAV enabled a characteristic energy funneling effect, which is absent in conventional hyperbranched polymer of 1,3,5‐hb‐PAV.
Chemistry of Ferroelectric Surfaces
Authors: Garrity K. , Kolpak A. M. , Ismail‐Beigi S. , Altman E. I.
Published: April 2010

It has been recognized since the 1950s that the polar and switchable nature of ferroelectric surfaces can potentially lead to polarization direction‐dependent surface chemistry. Recent theoretical studies and advances in growing high quality epitaxial ferroelectric thin films have motivated a flurry of experimental studies aimed at creating surfaces with switchable adsorption and catalytic properties, as well as films whose polarization direction switches depending on the gas phase environment. This research news article briefly reviews the key findings of these studies. These include observations that the adsorption strengths, and in certain cases the activation energies for reactions, of polar molecules on the surfaces of ferroelectric materials are sensitive to the polarization direction. For bare ferroelectric surfaces, the magnitudes of these differences are not large, but are still comparable to the energy barrier required to switch the polarization of ∼10 nm thick films. Highlights of a recent study where chemical switching of a thin film ferroelectric was demonstrated are presented. Attempts to use the ferroelectric polarization to influence the behavior of supported catalytic metals will also be described. It will be shown that the tendency of the metals to cluster into particles makes it difficult to alter the chemical properties of the metal surface, since it is separated from the ferroelectric by several layers of metal atoms. An alternate approach to increasing the reactivity of ferroelectric surfaces is suggested that involves modifying the surface with atoms that bind strongly to the surface and thus remain atomically dispersed.
Copper‐Catalyzed Three‐Component Synthesis of 2‐Iminodihydrocoumarins and 2‐Iminocoumarins
Authors: Shen Yang , Cui Sunliang , Wang Jing , Chen Xiaopeng , Lu Ping , Wang Yanguang
Published: April 2010

An efficient synthesis of N‐sulfonyl‐substituted 2‐imino‐3,4‐dihydrocoumarins and 2‐iminocoumarins via a copper‐catalyzed multicomponent reaction of sulfonyl azides with terminal alkynes and β‐(ortho‐hydroxyphenyl)‐α,β‐unsaturated ketones or ortho‐hydroxyphenylpropiolates has been developed. The cascade process involves trapping the keteimine by a nucleophilic addition and an intramolecular Michael addition. This methodology could well be extended to the concise synthesis of the polysubstituted piperidine scaffold.
Auditory function and hearing loss in children and adults with Williams syndrome: Cochlear impairment in individuals with otherwise normal hearing
Authors: Marler Jeffrey A. , Sitcovsky Jessica L. , Mervis Carolyn B. , Kistler Doris J. , Wightman Frederic L.
Published: April 2010

Hearing loss is common in school‐age individuals with Williams syndrome (WS) and extensive in adults. Prior studies with relatively small sample sizes suggest that hearing loss in WS has an early onset and may be progressive, yet the auditory phenotype and the scope of the hearing loss have not been adequately characterized. We used standard audiometric tools: Otoscopy, tympanometry, air‐conduction (bone conduction when available) behavioral testing, and distortion product otoacoustic emissions (DPOAEs) to measure hearing sensitivity and outer hair cell function. We tested 81 individuals with WS aged 5.33–59.50 years. Sixty‐three percent of the school‐age and 92% of the adult participants had mild to moderately‐severe hearing loss. The hearing loss in at least 50% was sensorineural. DPOAE testing corroborated behavioral results. Strikingly, 12 of 14 participants with hearing within normal limits bilaterally had 4,000‐Hz DPOAE input/output (DPOAE IO) functions indicative of outer hair cell damage and impaired cochlear compression. Our results indicate that hearing loss is very common in WS. Furthermore, individuals with WS who have “normal” hearing as defined by behavioral thresholds may actually have sub‐clinical impairments or undetected cochlear pathology. Our findings suggest outer hair cell dysfunction in otherwise normal hearing individuals. The DPOAE IO in this same group revealed growth functions typically seen in groups with noise‐induced damage. Given this pattern of findings, individuals with WS may be at increased risk of noise‐induced hearing loss. Recommendations regarding audiological testing for individuals with WS and accommodations for these individuals in both academic and nonacademic settings are provided. © 2010 Wiley‐Liss, Inc.
Feste Lösungen bei der Dissoziation von Iridiumoxyden
Authors: Wöhler Lothar , Wltzmann W.
Published: April 2010

Zusammenfassung.

1 . Die Spannungskurve des Dioxydes wurde aufgenommen und die bei der Zersetzung desselben erhaltenen niedrigeren Drucke als Erscheinung fester Lösung erkannt. Die Abhängigkeit der Drucke von der Konzentration der letzteren der Substanzbeschaffenheit wurde dargetan.

2. In Uebereinstimmung mit der Druckkurve wurde 1070 ° als die geeignetste ‘Temperatur zur schnellen Oxydation metallischen Iridiums Sauerstoff’ zu Dioxyd erkannt.

3. Die Unbeständigkeit des Iridiumsesquioxyds und des Oxyduls bei der Zersetzungstemperatur und dem Druck zerfallenden Dioxyds wurde gezeigt und damit der Zerfall Dioxyds in Metall und Sauerstoff nachgewiesen. Es wurde thermodynamisch die Wärmetönung dieser Reaktion in grober Annäherung berechnet zu rund 50 Kal.

4. Bei fortschreitender Zersetzung des Dioxyds wurde die Bildung zweier gesättigter Lösungen konstanten Druckes festgestellt und damit die von Deville und Debray beobachtete Unabhängigkeit der Zersetzungsspannung von dem Zersetzungsgrad aufgeklärt. Interessante Ueberschreitungserscheinungen wurden hierbei beobachtet.

5. Die Flüchtigkeit des Iridiums in Sauerstoff bei Temperaturen von 750 bis 1000 ° wurde quantitativ bestimmt, die Verflüchtigung mit Bildung eines endothermen Oxydes zu deuten versucht.
Polytomous logistic regression as a tool for exploring heterogeneity across birth defect subtypes: An example using anencephaly and spina bifida
Authors: Lupo Philip J. , Symanski Elaine , Waller D. Kim , Chan Wenyaw , Canfield Mark A. , Langlois Peter H. , Mitchell Laura E.
Published: April 2010

BACKGROUND

In birth defect epidemiology, phenotypic subgroups are often combined into a composite phenotype in an effort to increase statistical power. Although the validity of using composite phenotypes has been questioned, formal evaluations of the underlying assumption of effect homogeneity across component phenotypes have not been conducted.

METHODS

Polytomous logistic regression was used to assess effect heterogeneity of several generally accepted neural tube defect (NTD) risk factors across the component phenotypes of anencephaly and spina bifida. Data for these analyses were obtained from the National Birth Defects Prevention Study.

RESULTS

The use of a composite phenotype has the potential to mask associations specific to a component phenotype and in some cases the effect of a variable may be misattributed to the composite phenotype. For example, an association between infant sex and anencephaly (adjusted odds ratio [AOR], 1.5; 95% CI, 1.1–1.9) was masked when data from all NTDs were analyzed (AOR, 1.1; 95% CI, 0.9–1.3), whereas an association with maternal body mass index that was specific to spina bifida (AOR, 1.9; 95% CI, 1.6–2.4) was attributed to all NTDs (AOR, 1.6; 95% CI, 1.4–2.0). Furthermore, conclusions regarding effect heterogeneity based on ad hoc comparisons, rather than some formal assessment, may be vulnerable to considerable subjectivity, as was the case for the association of maternal Hispanic ethnicity with spina bifida (AOR, 1.4; 95% CI, 1.2–1.8) and anencephaly (AOR, 2.0; 95% CI, 1.5–2.8).

CONCLUSIONS

Polytomous logistic regression provides a useful tool for evaluating putative risk factors for which there is no a priori basis for assuming effect homogeneity across component phenotypes. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Evaluation of 60Co‐gamma radiosterilization on Chinese medicines with HPLC/FTIR
Authors: Huang Chiung‐Hua , Lee Shih‐Chang , Chen Yueh‐Sheng , Yao Chun‐Hsu
Published: April 2010

The aim of this study was to evaluate the effect of radiosterilization on 30 Chinese medicines using γ‐rays from the isotope 60Co. Two groups of Chinese medicines, non‐treated and dry samples, were treated using a 60Co irradiation source at the doses 0, 3, 6 and 9 kGy. After storage for 3 months, characterizations of chemical compounds and functional groups were performed by high‐performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy. The results of radiosterlization showed that nearly all of the medicines were decontaminated under the dose of 9 kGy. In most samples, chemical compounds and functional groups were not altered by the irradiation treatment. However, minor changes were found in the molecular structures of 14 medicines under the reported ‘safety dose’ (10 kGy). The drying process before irradiation could decrease the chemical changes caused by γ‐rays to 50%. The HPLC analysis of nine medicines revealed minor changes at a dose of 3 kGy. The findings in this study provide important information that may suggest the need for a re‐evaluation of the reported safety dose. Therefore, further investigation may be warranted to insure the safety of γ‐radiosterlization of Chinese medicines. Copyright © 2010 John Wiley & Sons, Ltd.
Improvement in the Collision Intensity of Grinding Media in High Energy Impact Mills
Authors: Prasad D. V. N. , Theuerkauf J.
Published: April 2010

The effect of the grinding chamber length and the grinding media diameter in a Spex 8000M mixer mill was reported earlier [1]. Now a modification of the grinding chamber shape was investigated. The results presented are based on DEM (discrete element method) simulations performed for the same mass of grinding media in all cases. It was found that the rounded end caps of the grinding chamber gave higher collisional intensities of the grinding media compared to the flat end caps. The collision intensity can be maximized by adjusting the roundness of the end caps. For end cap curvatures of R/3 and R/4 (R is the radius of the grinding chamber), along the horizontal axis results in the highest intensity collisions compared to other cases studied. The maximum increase in the grinding media collision intensity in modified end caps was observed to be about 75 % for one particular grinding media diameter.
Retarding Effect of Contaminants on the Performance of a Two‐Impinging‐Jets Liquid‐Liquid Extraction Contactor
Authors: Saien J. , Doghahe S. A. O. , Dehkordi A. M.
Published: April 2010

In industrial liquid‐liquid extraction processes, the feed is not clean liquid but there are various kinds of contaminants in the feed entering the extractors. In this regard, a two‐impinging‐jets contacting device (TIJCD) was tested through the standard test system recommended by the European Federation of Chemical Engineering (EFCE), namely toluene‐acetone‐water, in the presence and absence of various types of surface‐active agents (SAAs). The influences of anionic, cationic, and nonionic SAAs such as sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium chloride (DTMAC), and octylphenol decaethylene glycol ether (Triton X‐100), respectively, on the extraction efficiency and overall volumetric mass transfer coefficient of a TIJCD were investigated. It was found that the presence of a little amount of the above named contaminants greatly decreases the performance capability of the TIJCD. On the basis of the experimental results obtained for various types of surfactants, the overall volumetric mass transfer coefficients obtained have satisfactorily been correlated in terms of Weber (We) and Eötvös (Eö) numbers.
Role of Different Parameters in the Optimization of Hydrodynamic Cavitation
Authors: Braeutigam P. , Franke M. , Wu Z.‐L. , Ondruschka B.
Published: April 2010

Low pressure setups (up to 150 psi) for creating hydrodynamic cavitation are investigated in this study. The decomposition of chloroform in water is used as a model reaction. The effects of upstream pressure, fluid velocity, Cavitation number, Cv, and β0 on the conversion are compared with regard to the effectiveness (conversion per pass) with changing flow conditions and scale‐up terms within three different setups. The values of Cv and β0 are seen to be significant parameters in optimizing the hydrodynamic cavitation. Moreover, the optimal values of these parameters shift to smaller values with increasing pipe diameter. The influence of a new orifice plate specific parameter, δ, on the collapse conditions, is also described.
Assessing the influence of heart rate in local hemodynamics through coupled 3D‐1D‐0D models
Authors: Blanco P. J. , Urquiza S. A. , Feijóo R. A.
Published: April 2010

In this study, a coupled dimensionally‐heterogeneous model of the systemic circulation is applied in order to study computationally the influence of the heart rate in the local hemodynamics. This is achieved by using a 3D‐1D‐0D model of the whole arterial tree accounting for: details of the local blood flow in the vessel of interest through 3D models, the wave propagation phenomena in the larger arteries by means of 1D models and, the peripheral microvascular beds via 0D models. Two applications are presented which aim at assessing the influence of the global setting of the vascular network on the local hemodynamics. In the first example, the hemodynamics in a patient‐specific model of the abdominal aorta is studied for two different systemic scenarios corresponding to different resting heart rates. In the second example, the blood flow in a standardized model of the carotid artery is analyzed for different heart rates including the resting state and several other exercise regimes. Copyright © 2010 John Wiley & Sons, Ltd.
Extreme scalability challenges in micro‐finite element simulations of human bone
Authors: Bekas C. , Curioni A. , Arbenz P. , Flaig C. , Van Lenthe G. H. , Müller R. , Wirth A. J.
Published: April 2010

Coupling recent imaging capabilities with microstructural finite element (µFE) analysis offers a powerful tool to determine bone stiffness and strength. It shows high potential to improve the individual fracture risk prediction, a tool much needed in the diagnosis and treatment of osteoporosis, that is, according to the World Health Organization (WHO), second only to cardiovascular disease as a leading health‐care problem. We adapted a multilevel preconditioned conjugate gradient method to solve the very large voxel models that arise in the µFE bone structure analysis. The intricate microstructure properties of bone lead to sparse matrices with billions of rows, thus rendering this application to be an ideal candidate for massively parallel architectures such as the BG/L Supercomputer. In this work we present our progress as well as the challenges we were able to identify in our quest to achieve scalability to thousands of BG/L cores. Copyright © 2010 John Wiley & Sons, Ltd.
JEL: unified resource tracking for parallel and distributed applications
Authors: Drost Niels , van Nieuwpoort Rob V. , Maassen Jason , Seinstra Frank , Bal Henri E.
Published: April 2010

When parallel applications are run in large‐scale distributed environments, such as grids, peer‐to‐peer (P2P) systems, and clouds, the set of resources used can change dynamically as machines crash, reservations end, and new resources become available. It is vital for applications to respond to these changes. Therefore, it is necessary to keep track of the available resources—a problem which is known to be notoriously difficult. In this article we argue that resource tracking must be provided as the standard functionality in the lower parts of the software stack. We propose a general solution to resource tracking: the Join–Elect–Leave (JEL) model. JEL provides unified resource tracking for parallel and distributed applications across environments. JEL is a simple yet powerful model based on notifying when resources have Joined or Left the computation. We demonstrate that JEL is suitable for resource tracking in a wide variety of programming models, ranging from the fixed resource sets traditionally used in MPI‐1 to flexible grid‐oriented programming models. We compare several JEL implementations, and show these to perform and scale well in several real‐world scenarios involving grids, clouds and P2P systems applied concurrently, and wide‐area systems with failing resources. Using JEL, we have won the first prize in a number of international distributed computing competitions. Copyright © 2010 John Wiley & Sons, Ltd.
Microemulsion synthesis and characterization of aluminum doped ZnO nanorods
Authors: Lim S. K. , Hwang S. H. , Kim S.
Published: April 2010

Aluminium doped ZnO (AZO) nanorods were synthesized by microemulsion method with different types of surfactants. Scanning electron microscopy observations show that the ZnO nanorods have diameters around about 80 nm and lengths up to several micrometers. The room temperature photoluminescence (PL) spectrum of AZO nanorods exhibited a sharp and strong ultraviolet bandgap at 383 nm and a relatively weaker emission associated with the defect level. AZO nanorods synthesized with sodium benzene sulfonate (SBS) surfactant showed lower resistivity than aluminum doped ZnO nanorods synthesized with dodecyl benzene sulfonic acid sodium salt (DBS) surfactant. Resistivity of AZO nanorods synthesized with SBS surfactant showed 2.8×103 Ωcm. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dehydration behaviour of hydrates
Authors: Dette S. S. , Stelzer T. , Jones M. J. , Ulrich J.
Published: April 2010

Immersing a crystalline solvate in a suitable anti‐solvent can induce phase transformation to solvent‐free solid phase. In certain cases the solvent‐mediated phase transition results in the generation of hollow, tubular structures. Both the tube dimensions of sodium‐2‐keto‐L‐gulonate anhydrate (skga) and the dehydration kinetics of sodium‐2‐keto‐L‐gulonate monohydrate (skgm) can be modified by the antisolvent employed. An explanation for the variable dehydration behaviour of skgm in the antisolvents is presented here. Furthermore, other crystalline hydrates were dehydrated in dry methanol. Providing an operational window can be found, any hydrate material could possibly find use in the production of tubes (micro‐ or nanotubes for different applications). The experimental conditions selected (dry methanol as antisolvent, dehydration temperature at 25 °C) for the dehydration did not lead to the anhydrate tube growth for all hydrates investigated. Based upon the results presented here a first hypothesis is presented to explain this effect. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transcription factor 7‐like 2 (TCF7L2) polymorphism and context‐specific risk of impaired fasting glucose in African American and Caucasian adults: the atherosclerosis risk in communities (ARIC) study
Authors: Yan Yu , North Kari E. , Heiss Gerardo , Klein Ronald , Girman Cynthia J. , Lange Ethan M. , Pankow James S. , Brancati Frederick L. , Boerwinkle Eric
Published: April 2010

Background

Although variants in the transcription factor 7‐like 2 (TCF7L2) gene are consistently associated with impaired fasting glucose (IFG) in Caucasians, data from large population‐based studies of African Americans are lacking. Moreover, few studies have investigated the effects of TCF7L2 on IFG in the context of metabolic risk factors for diabetes.

Methods

We investigated the association between the TCF7L2 rs7903146 polymorphism and incident IFG defined as fasting serum glucose levels of 100–125 mg/dL (5.6–6.9 mmol/L) in 1377 African American and 5152 Caucasian participants without diabetes and IFG at intake who participated in the Atherosclerosis Risk in Communities (ARIC) Study from 1987 to1989 and were followed for 9 years.

Results

Incident IFG was identified in 810 (58.8%) African American and 2652 (51.5%) Caucasian participants. Compared to homozygous CC Caucasian individuals, heterozygous CT [hazard ratio (HR) = 1.09 (95% CI = 1.03–1.15)] and homozygous TT [1.18 (1.05–1.33)] individuals had significantly higher risk of developing IFG over 9‐year follow‐up. The association between rs7903146 and IFG risk was stronger in Caucasians with obesity [HRCTvs.CC = 1.28 (1.12, 1.47); HRTTvs.CC = 1.65 (1.25, 2.17)] or high triglycerides [HRCTvs.CC = 1.31(1.10, 1.56); HRTTvs.CC = 1.72 (1.21, 2.43)]. No association of the TCF7L2 rs7903146 polymorphism and incident IFG was noted in African Americans.

Conclusions

Our study replicates the association between rs7903146 and IFG risk in a population‐based, longitudinal cohort of Caucasians but not in African Americans. For the first time, our study provides evidence for interactions between TCF7L2 and metabolic risk factors on the occurrence of IFG in Caucasians. Copyright © 2010 John Wiley & Sons, Ltd.
Prrxl1 is required for the generation of a subset of nociceptive glutamatergic superficial spinal dorsal horn neurons
Authors: Rebelo Sandra , Reguenga Carlos , Lopes Claúdia , Lima Deolinda
Published: April 2010

Perception of noxious events relies on activation of complex central neuronal circuits. The spinal cord dorsal horn plays a pivotal role in the process relaying to the brain various types of somatosensory input. These functions are accomplished by distinct sensory neurons specifically organized in different laminae. They differentiate during development in a spatial‐temporal order due to the expression of combinatorial sets of homeodomain transcription factors. Here we demonstrate that the differential expression of the homeodomain transcription factors Prrxl1 (DRG11), Tlx3, and Lmx1b defines various subpopulations of spinal cord dorsal horn glutamatergic early born and late born neurons. Accordingly, in the superficial dorsal horn of Prrxl1−/− mice, the number of glutamatergic neurons is reduced by 70%, while the number of Golgi‐impregnated and noxious‐induced Fos immunoreactive neurons is reduced by 85%. These results suggest a crucial role for Prrxl1 in the generation of various subpopulations of nociceptive glutamatergic superficial dorsal horn neurons. Developmental Dynamics 239:1684–1694, 2010. © 2010 Wiley‐Liss, Inc.
Rare‐Earth Metal Phenyl(trimethylsilyl)amide Complexes
Authors: Schädle Christoph , Meermann Christian , Törnroos Karl W. , Anwander Reiner
Published: April 2010

The reactions of common rare‐earth metal chloride, borohydride, and triflate precursors – LnCl3(thf)x, Ln(BH4)3(thf)3, and La(OTf)3 – with alkali metal amide complexes M[N(SiMe3)(C6H3iPr2‐2,6)] (M[NRR′]; M = Li, K) were investigated in thf or hexane as a solvent. A diverse range of products was obtained comprising alkali metal‐free mono(rare‐earth metal) complexes Y[NRR′]Cl2(thf)3 and Ln[NRR′]2(BH4)(thf) (Ln = Nd, La), as well as the mononeodymium ate complex {Nd[NRR′]2(BH4)2}{Li(thf)4} and polymeric ate complexes {La[NRR′]2(thf)(μ‐Cl)K(thf)2(μ‐Cl)}n and {Nd[NRR′]2(μ‐BH4)Li(thf)2(μ‐BH4)}n. All compounds were characterized by NMR (1H and 13C) and FTIR spectroscopy, elemental and X‐ray structure analyses. The lithium salts Li[NRR′](thf)3 and Li4(OTf)4(thf)6 were isolated as side products and structurally characterized. The homoleptic complex La[NRR′]3 was prepared following two synthesis protocols in hexane, either by reacting Ln[NRR′]2(BH4)(thf) with 1 equiv. of K[NRR′] or treatment of LaCl3(thf)1.25 with 3 equiv. of K[NRR′].
Microfluidic preparative free‐flow isoelectric focusing in a triangular channel: System development and characterization
Authors: Wen Jian , Albrecht Jacob W. , Jensen Klavs F.
Published: April 2010

A preparative scale free‐flow IEF device is developed and characterized with the aim of addressing needs of molecular biologists working with protein samples on the milligrams and milliliters scale. A triangular‐shape separation channel facilitates the establishment of the pH gradient with a corresponding increase in separation efficiency and decrease in focusing time compared with that in a regular rectangular channel. Functionalized, ion‐permeable poly(acrylamide) gel membranes are sandwiched between PDMS and glass layers to both isolate the electrode buffers from the central separation channel and also to selectively adjust the voltage efficiency across the separation channel to achieve high electric field separation. The 50×70 mm device is fabricated by soft lithography and has 24 outlets evenly spaced across a pH gradient between pH 4 and 10. This preparative free‐flow IEF system is investigated and optimized for both aqueous and denaturing conditions with respect to the electric field and potential efficiency and with consideration of Joule‐heating removal. Energy distribution across the functionalized polyacrylamide gel is investigated and controlled to adjust the potential efficiency between 15 and 80% across the triangular separation channel. The device is able to achieve constant electric fields high as 370±20 V/cm through the entire triangular channel given the separation voltage of 1800 V, enabling separation of five fluorescent pI markers as a demonstration example.
SERS decoding of micro gold shells moving in microfluidic systems
Authors: Lee Saram , Joo Segyeong , Park Sejin , Kim Soyoun , Kim Hee Chan , Chung Taek Dong
Published: April 2010

In this study, in situ surface‐enhanced Raman scattering (SERS) decoding was demonstrated in microfluidic chips using novel thin micro gold shells modified with Raman tags. The micro gold shells were fabricated using electroless gold plating on PMMA beads with diameter of 15 μm. These shells were sophisticatedly optimized to produce the maximum SERS intensity, which minimized the exposure time for quick and safe decoding. The shell surfaces produced well‐defined SERS spectra even at an extremely short exposure time, 1 ms, for a single micro gold shell combined with Raman tags such as 2‐naphthalenethiol and benzenethiol. The consecutive SERS spectra from a variety of combinations of Raman tags were successfully acquired from the micro gold shells moving in 25 μm deep and 75 μm wide channels on a glass microfluidic chip. The proposed functionalized micro gold shells exhibited the potential of an on‐chip microfluidic SERS decoding strategy for micro suspension array.
Separation and recovery of nucleic acids with improved biological activity by acid‐degradable polyacrylamide gel electrophoresis
Authors: Kim Yoon Kyung , Kwon Young Jik
Published: April 2010

One of the fundamental challenges in studying biomacromolecules (e.g. nucleic acids and proteins) and their complexes in a biological system is isolating them in their structurally and functionally intact forms. Electrophoresis offers convenient and efficient separation and analysis of biomacromolecules but recovery of separated biomacromolecules is a significant challenge. In this study, DNAs of various sizes were separated by electrophoresis in an acid‐degradable polyacrylamide gel. Almost 100% of the nucleic acids were recovered after the identified gel bands were hydrolyzed under a mildly acidic condition and purified using anion exchange resin. Further concentration by centrifugal filtration and a second purification using ion exchange column chromatography yielded 44–84% of DNA. The second conventional (non‐degradable) gel electrophoresis confirmed that the nucleic acids recovered from acid‐degradable gel bands preserved their electrophoretic properties through acidic gel hydrolysis, purification, and concentration processes. The plasmid DNA recovered from acid‐degradable gel transfected cells significantly more efficiently than the starting plasmid DNA (i.e. improved biological activity via acid‐degradable PAGE). Separation of other types of nucleic acids such as small interfering RNA using this convenient and efficient technique was also demonstrated.
Removal of reactive textile dyes (Remazol Brillant Blue R and Remazol Yellow) by surfactant‐modified natural zeolite
Authors: Kuleyin Ayşe , Aydin Fulya
Published: April 2010

In this study, surfactant‐modified zeolite (SMZ) was used to remove Remazol Brillant Blue R and Remazol Yellow reactive dyes from aqueous solutions. The influences of suspension pH, temperature, agitation rate, and the SMZ dosage on reactive dyes removal and adsorption capacity were investigated by conducting a series of batch adsorption experiments. The adsorption kinetics was tested for pseudo‐first‐order, pseudo‐second order, intraparticle diffusion model, Elovich, and Bangham models, and rate constants of the kinetic models were calculated. Equilibrium isotherms for the adsorption of reactive dyes were analyzed by the Freundlich, Langmuir, Dubinin–Radushkevich, and Tempkin isotherm models. The Langmuir monolayer adsorption capacities of Remazol Brillant Blue R and Remazol Yellow were estimated as 13.9 and 38.31 mg/g, respectively. The adsorption rate was rapid; more than half of the adsorbed Remazol Brillant Blue R was removed in the first 60 min and of Remazol Yellow in the first 30 min. Thermodynamic parameters such as ΔH0, ΔS0, and ΔG0, at 20°C, were found to be 5.2126 kJ/mol, 0.0273 kJ/mol K, and −2.7969 kJ/mol (Remazol Brillant Blue R), and 29.9747 kJ/mol, 0.10875 kJ/mol K, and −1.8900 kJ/mol (Remazol Yellow), respectively. © 2010 American Institute of Chemical Engineers Environ Prog, 2011