bluuebunny/crossref_metadata_2025 huggingface dataset:
Study protocol of the German "Registry for the Detection of Late Sequelae after Radiotherapy in Childhood and Adolescence" (RiSK)
Authors: Bolling Tobias , Schuck Andreas , Pape Hildegard , Rube Christian , Pollinger Barbara , Timmermann Beate , Kortmann Rolf D , Dieckmann Karin , Willich Normann
Published: April 2008

Background

Late effects after radiotherapy in childhood and adolescence have mainly been characterized retrospectively with small patient numbers. However, these analyses are limited due to little information regarding organ dose levels in many cases. To overcome this limitation, the German Group of Paediatric Radiation Oncology (APRO) established the „Registry for the evaluation of late side effects after radiation in childhood and adolescence” (RiSK). The study protocol and the documentation forms are given in this publication.

Methods/Design

Radiation parameters including detailed organ doses as well as toxicity evaluations are collected prospectively from centres all over Germany. Standardized documentation forms are used. These forms are given in an English and German version as additional files to this publication. Documentation is planned for all children who receive radiotherapy in one of the therapy trials of the "German Society of Paediatric Oncology and Haematology (GPOH)". The study started in a pilot phase in June 2001 in few centres. Since 2004 documentation has been performed all over Germany and is still on-going.

Discussion

To our knowledge, "RiSK" is the only multi-centre study that evaluates radiation associated side effects prospectively with detailed information about organ dose levels. With ongoing recruitment and prolongation of follow-up powerful data will be obtained in a few years. A broad use and international cooperation are welcome.
Fibrin and poly(lactic-co-glycolic acid) hybrid scaffold promotes early chondrogenesis of articular chondrocytes: an in vitro study
Authors: Sha'ban Munirah , Kim Soon Hee , Idrus Ruszymah BH , Khang Gilson
Published: April 2008

Background

Synthetic- and naturally derived- biodegradable polymers have been widely used to construct scaffolds for cartilage tissue engineering. Poly(lactic-co-glycolic acid) (PLGA) are bioresorbable and biocompatible, rendering them as a promising tool for clinical application. To minimize cells lost during the seeding procedure, we used the natural polymer fibrin to immobilize cells and to provide homogenous cells distribution in PLGA scaffolds. We evaluated in vitro chondrogenesis of rabbit articular chondrocytes in PLGA scaffolds using fibrin as cell transplantation matrix.

Methods

PLGA scaffolds were soaked in chondrocytes-fibrin suspension (1 × 106cells/scaffold) and polymerized by dropping thrombin-calcium chloride (CaCl2) solution. PLGA-seeded chondrocytes was used as control. All constructs were cultured for a maximum of 21 days. Cell proliferation activity was measured at 1, 3, 7, 14 and 21 days in vitro using 3-(4,5-dimethylthiazole-2-yl)-2-, 5-diphenyltetrazolium-bromide (MTT) assay. Morphological observation, histology, immunohistochemistry (IHC), gene expression and sulphated-glycosaminoglycan (sGAG) analyses were performed at each time point of 1, 2 and 3 weeks to elucidate in vitro cartilage development and deposition of cartilage-specific extracellular matrix (ECM).

Results

Cell proliferation activity was gradually increased from day-1 until day-14 and declined by day-21. A significant cartilaginous tissue formation was detected as early as 2-week in fibrin/PLGA hybrid construct as confirmed by the presence of cartilage-isolated cells and lacunae embedded within basophilic ECM. Cartilage formation was remarkably evidenced after 3 weeks. Presence of cartilage-specific proteoglycan and glycosaminoglycan (GAG) in fibrin/PLGA hybrid constructs were confirmed by positive Safranin O and Alcian Blue staining. Collagen type II exhibited intense immunopositivity at the pericellular matrix. Chondrogenic properties were further demonstrated by the expression of genes encoded for cartilage-specific markers, collagen type II and aggrecan core protein. Interestingly, suppression of cartilage dedifferentiation marker; collagen type I was observed after 2 and 3 weeks of in vitro culture. The sulphated-glycosaminoglycan (sGAG) production in fibrin/PLGA was significantly higher than in PLGA.

Conclusion

Fibrin/PLGA promotes early in vitro chondrogenesis of rabbit articular chondrocytes. This study suggests that fibrin/PLGA may serve as a potential cell delivery vehicle and a structural basis for in vitro tissue-engineered articular cartilage.
HIP2: An online database of human plasma proteins from healthy individuals
Authors: Saha Sudipto , Harrison Scott H , Shen Changyu , Tang Haixu , Radivojac Predrag , Arnold Randy J , Zhang Xiang , Chen Jake Yue
Published: April 2008

Background

With the introduction of increasingly powerful mass spectrometry (MS) techniques for clinical research, several recent large-scale MS proteomics studies have sought to characterize the entire human plasma proteome with a general objective for identifying thousands of proteins leaked from tissues in the circulating blood. Understanding the basic constituents, diversity, and variability of the human plasma proteome is essential to the development of sensitive molecular diagnosis and treatment monitoring solutions for future biomedical applications. Biomedical researchers today, however, do not have an integrated online resource in which they can search for plasma proteins collected from different mass spectrometry platforms, experimental protocols, and search software for healthy individuals. The lack of such a resource for comparisons has made it difficult to interpret proteomics profile changes in patients' plasma and to design protein biomarker discovery experiments.

Description

To aid future protein biomarker studies of disease and health from human plasma, we developed an online database, HIP2 (Healthy Human Individual's Integrated Plasma Proteome). The current version contains 12,787 protein entries linked to 86,831 peptide entries identified using different MS platforms.

Conclusion

This web-based database will be useful to biomedical researchers involved in biomarker discovery research. This database has been developed to be the comprehensive collection of healthy human plasma proteins, and has protein data captured in a relational database schema built to contain mappings of supporting peptide evidence from several high-quality and high-throughput mass-spectrometry (MS) experimental data sets. Users can search for plasma protein/peptide annotations, peptide/protein alignments, and experimental/sample conditions with options for filter-based retrieval to achieve greater analytical power for discovery and validation.
Introduction of Medical Emergency Teams in Australia and New Zealand: a multi-centre study
Authors: Jones Daryl , George Carol , Hart Graeme K , Bellomo Rinaldo , Martin Jacqueline
Published: April 2008

Introduction

Information about Medical Emergency Teams (METs) in Australia and New Zealand (ANZ) is limited to local studies and a cluster randomised controlled trial (the Medical Emergency Response and Intervention Trial [MERIT]). Thus, we sought to describe the timing of the introduction of METs into ANZ hospitals relative to relevant publications and to assess changes in the incidence and rate of intensive care unit (ICU) admissions due to a ward cardiac arrest (CA) and ICU readmissions.

Methods

We used the Australian and New Zealand Intensive Care Society database to obtain the study data. We related MET introduction to publications about adverse events and MET services. We compared the incidence and rate of readmissions and admitted CAs from wards before and after the introduction of an MET. Finally, we identified hospitals without an MET system which had contributed to the database for at least two years from 2002 to 2005 and measured the incidence of adverse events from the first year of contribution to the second.

Results

The MET status was known for 131 of the 172 (76.2%) hospitals that did not participate in the MERIT study. Among these hospitals, 110 (64.1%) had introduced an MET service by 2005. In the 79 hospitals in which the MET commencement date was known, 75% had introduced an MET by May 2002. Of the 110 hospitals in which an MET service was introduced, 24 (21.8%) contributed continuous data in the year before and after the known commencement date. In these hospitals, the mean incidence of CAs admitted to the ICU from the wards changed from 6.33 per year before to 5.04 per year in the year after the MET service began (difference of 1.29 per year, 95% confidence interval [CI] -0.09 to 2.67; P = 0.0244). The incidence of ICU readmissions and the mortality for both ICU-admitted CAs from wards and ICU readmissions did not change. Data were available to calculate the change in ICU admissions due to ward CAs for 16 of 62 (25.8%) hospitals without an MET system. In these hospitals, admissions to the ICU after a ward CA decreased from 5.0 per year in the first year of data contribution to 4.2 per year in the following year (difference of 0.8 per year, 95% CI -0.81 to 3.49; P = 0.3).

Conclusion

Approximately 60% of hospitals in ANZ with an ICU report having an MET service. Most introduced the MET service early and in association with literature related to adverse events. Although available in only a quarter of hospitals, temporal trends suggest an overall decrease in the incidence of ward CAs admitted to the ICU in MET as well as non-MET hospitals.
Diagnosis of ventilator-associated pneumonia: a systematic review of the literature
Authors: Rea-Neto Alvaro , Youssef Nazah Cherif M , Tuche Fabio , Brunkhorst Frank , Ranieri V Marco , Reinhart Konrad , Sakr Yasser
Published: April 2008

Introduction

Early, accurate diagnosis is fundamental in the management of patients with ventilator-associated pneumonia (VAP). The aim of this qualitative review was to compare various criteria of diagnosing VAP in the intensive care unit (ICU) with a special emphasis on the value of clinical diagnosis, microbiological culture techniques, and biomarkers of host response.

Methods

A MEDLINE search was performed using the keyword 'ventilator associated pneumonia' AND 'diagnosis'. Our search was limited to human studies published between January 1966 and June 2007. Only studies of at least 25 adult patients were included. Predefined variables were collected, including year of publication, study design (prospective/retrospective), number of patients included, and disease group.

Results

Of 572 articles fulfilling the initial search criteria, 159 articles were chosen for detailed review of the full text. A total of 64 articles fulfilled the inclusion criteria and were included in our review. Clinical criteria, used in combination, may be helpful in diagnosing VAP, however, the considerable inter-observer variability and the moderate performance should be taken in account. Bacteriologic data do not increase the accuracy of diagnosis as compared to clinical diagnosis. Quantitative cultures obtained by different methods seem to be rather equivalent in diagnosing VAP. Blood cultures are relatively insensitive to diagnose pneumonia. The rapid availability of cytological data, including inflammatory cells and Gram stains, may be useful in initial therapeutic decisions in patients with suspected VAP. C-reactive protein, procalcitonin, and soluble triggering receptor expressed on myeloid cells are promising biomarkers in diagnosing VAP.

Conclusion

An integrated approach should be followed in diagnosing and treating patients with VAP, including early antibiotic therapy and subsequent rectification according to clinical response and results of bacteriologic cultures.
Systemic 5-fluorouracil treatment causes a syndrome of delayed myelin destruction in the central nervous system
Authors: Han Ruolan , Yang Yin M , Dietrich Joerg , Luebke Anne , Mayer-Pröschel Margot , Noble Mark
Published: April 2008

Background

Cancer treatment with a variety of chemotherapeutic agents often is associated with delayed adverse neurological consequences. Despite their clinical importance, almost nothing is known about the basis for such effects. It is not even known whether the occurrence of delayed adverse effects requires exposure to multiple chemotherapeutic agents, the presence of both chemotherapeutic agents and the body's own response to cancer, prolonged damage to the blood-brain barrier, inflammation or other such changes. Nor are there any animal models that could enable the study of this important problem.

Results

We found that clinically relevant concentrations of 5-fluorouracil (5-FU; a widely used chemotherapeutic agent) were toxic for both central nervous system (CNS) progenitor cells and non-dividing oligodendrocytes in vitro and in vivo. Short-term systemic administration of 5-FU caused both acute CNS damage and a syndrome of progressively worsening delayed damage to myelinated tracts of the CNS associated with altered transcriptional regulation in oligodendrocytes and extensive myelin pathology. Functional analysis also provided the first demonstration of delayed effects of chemotherapy on the latency of impulse conduction in the auditory system, offering the possibility of non-invasive analysis of myelin damage associated with cancer treatment.

Conclusions

Our studies demonstrate that systemic treatment with a single chemotherapeutic agent, 5-FU, is sufficient to cause a syndrome of delayed CNS damage and provide the first animal model of delayed damage to white-matter tracts of individuals treated with systemic chemotherapy. Unlike that caused by local irradiation, the degeneration caused by 5-FU treatment did not correlate with either chronic inflammation or extensive vascular damage and appears to represent a new class of delayed degenerative damage in the CNS.
Differential roles of ICAM-1 and VCAM-1 in leukocyte-endothelial cell interactions in skin and brain of MRL/faslprmice
Authors: Norman M Ursula , James Will G , Hickey Michael J
Published: April 2008

MRL/faslpr mice, which undergo a systemic autoimmune disease with similarities to systemic lupus erythematosus (SLE), display reduced pathology and prolonged survival if rendered deficient in ICAM-1. However, it remains unclear whether this is a result of the ability of ICAM-1 to promote the immune response or mediate leukocyte recruitment. Therefore, the aim of these studies was to compare the role of ICAM-1 in the elevated leukocyte-endothelial interactions, which affect MRL/faslpr mice. Intravital microscopy was used to compare leukocyte rolling and adhesion in postcapillary venules in the dermal and cerebral (pial) microcirculations of wild-type (ICAM+/+) and ICAM-1-deficient (ICAM-1−/−) MRL/faslpr mice. In the dermal microcirculation of 16-week MRL/faslpr mice, leukocyte adhesion was increased relative to nondiseased MRL+/+ mice. However, this increase was abolished in ICAM-1−/− MRL/faslpr mice. ICAM-1 deficiency was also associated with reduced dermal pathology. In contrast, in the pial microcirculation, the elevation in leukocyte adhesion observed in ICAM+/+ MRL/faslpr mice also occurred in ICAM-1−/− MRL/faslpr mice. VCAM-1 expression was detectable in both vascular beds, but higher levels were detected in the pial vasculature. Furthermore, VCAM-1 blockade significantly reduced leukocyte adhesion and rolling in the cerebral microcirculation of ICAM-1−/− MRL/faslpr mice. Therefore, ICAM-1 was critical for leukocyte adhesion in the skin but not the brain, where VCAM-1 assumed the major function. Given the ongoing development of anti-adhesion molecule therapies and their potential in inflammatory diseases such as SLE, these data indicate that implementation of these therapies in SLE should take into account the potential for tissue-specific functions of adhesion molecules.
Higher Doses of Lenalidomide Are Associated With Unacceptable Toxicity Including Life-Threatening Tumor Flare in Patients With Chronic Lymphocytic Leukemia
Authors: Andritsos Leslie A. , Johnson Amy J. , Lozanski Gerard , Blum William , Kefauver Cheryl , Awan Farrukh , Smith Lisa L. , Lapalombella Rosa , May Sarah E. , Raymond Chelsey A. , Wang Da-Sheng , Knight Robert D. , Ruppert Amy S. , Lehman Amy , Jarjoura David , Chen Ching-Shih , Byrd John C.
Published: April 2008

Purpose

Lenalidomide is a novel therapeutic agent with uncertain mechanism of action that is clinically active in myelodysplastic syndrome (MDS) and multiple myeloma (MM). Application of high (MM) and low (MDS) doses of lenalidomide has been reported to have clinical activity in CLL. Herein, we highlight life-threatening tumor flare when higher doses of lenalidomide are administered to patients with CLL and provide a potential mechanism for its occurrence.

Patients and Methods

Four patients with relapsed CLL were treated with lenalidomide (25 mg/d for 21 days of a 28-day cycle). Serious adverse events including tumor flare and tumor lysis are summarized. In vitro studies examining drug-induced apoptosis and activation of CLL cells were also performed.

Results

Four consecutive patients were treated with lenalidomide; all had serious adverse events. Tumor flare was observed in three patients and was characterized by dramatic and painful lymph node enlargement resulting in hospitalization of two patients, with one fatal outcome. Another patient developed sepsis and renal failure. In vitro studies demonstrated lenalidomide-induced B-cell activation (upregulation of CD40 and CD86) corresponding to degree of tumor flare, possibly explaining the tumor flare observation.

Conclusion

Lenalidomide administered at 25 mg/d in relapsed CLL is associated with unacceptable toxicity; the rapid onset and adverse clinical effects of tumor flare represent a significant limitation of lenalidomide use in CLL at this dose. Drug-associated B-cell activation may contribute to this adverse event. Future studies with lenalidomide in CLL should focus on understanding this toxicity, investigating patients at risk, and investigating alternative safer dosing schedules.
Risedronate Prevents Bone Loss in Breast Cancer Survivors: A 2-Year, Randomized, Double-Blind, Placebo-Controlled Clinical Trial
Authors: Greenspan Susan L. , Brufsky Adam , Lembersky Barry C. , Bhattacharya Rajib , Vujevich Karen T. , Perera Subashan , Sereika Susan M. , Vogel Victor G.
Published: April 2008

Purpose

Limited data are available on the efficacy of oral bisphosphonate therapy in breast cancer survivors. Our goal was to examine prevention of breast cancer–related bone loss in this cohort.

Patients and Methods

Eighty-seven postmenopausal women after chemotherapy for breast cancer were randomly assigned to once-weekly risedronate 35 mg or placebo for 24 months. Outcomes included bone mineral density (BMD) and turnover markers.

Results

At study initiation, 13% of patients were on an aromatase inhibitor (AI). After 24 months, there were differences of 1.6 to 2.5% (P < .05) at the spine and hip BMD between the placebo and risedronate groups. At study completion, 44% were on an AI. Adjusting for an AI, women on placebo plus AI had a decrease in BMD of (mean ± SE) 4.8% ± 0.8% at the spine and 2.8% ± 0.5% at the total hip (both P < .001). In women on risedronate + AI, the spine decreased by 2.4% ± 1.1% (P < .05) and was stable at the hip. Women in the placebo group not on an AI, maintained BMD at the spine, and had a 1.2% ± 0.5% loss at the total hip (P < .05). Women who received risedronate but no AI had the greatest improvement in BMD of 2.2% ± 0.9% (P < .05) at the total hip. Bone turnover was reduced with risedronate. There were no differences in adverse events between the groups.

Conclusion

We conclude that in postmenopausal women with breast cancer with or without AI therapy, once-weekly oral risedronate was beneficial for spine and hip BMD, reduced bone turnover, and was well tolerated.
Farnesoid X Receptor Protects Liver Cells from Apoptosis Induced by Serum Deprivation in Vitro and Fasting in Vivo
Authors: Wang Yan-Dong , Yang Fan , Chen Wei-Dong , Huang Xiongfei , Lai Lily , Forman Barry M. , Huang Wendong
Published: April 2008

The farnesoid X receptor (FXR) is a key metabolic regulator in the liver by maintaining the homeostasis of liver metabolites. Recent findings suggest that FXR may have a much broader function in liver physiology and pathology. In the present work, we identify a novel role of FXR in protecting liver cell from apoptosis induced by nutritional withdrawal including serum deprivation in vitro or starvation in vivo. Two FXR ligands, chenodeoxycholic acid (CDCA) and GW4064, rescued HepG2 cells from serum deprivation-induced apoptosis in a dose-dependent manner. This effect of FXR on apoptotic suppression was compromised when FXR was knocked down by short interfering RNA. Similarly, the effects of both CDCA and GW4064 were abolished after inhibition of the MAPK pathway by a specific inhibitor of MAPK kinase 1/2. Immunoblotting results indicated that FXR activation by CDCA and GW4064 induced ERK1/2 phosphorylation, which was attenuated by serum deprivation. In vivo, FXR−/− mice exhibited an exacerbated liver apoptosis and lower levels of phosphorylated-ERK1/2 compared to wild-type mice after starvation. In conclusion, our results suggest a novel role of FXR in modulating liver cell apoptosis.
FGF signalling controls formation of the apical sensory organ in the cnidarianNematostella vectensis
Authors: Rentzsch Fabian , Fritzenwanker Jens H. , Scholz Corinna B. , Technau Ulrich
Published: April 2008

Fibroblast growth factor (FGF) signalling regulates essential developmental processes in vertebrates and invertebrates, but its role during early metazoan evolution remains obscure. Here, we analyse the function of FGF signalling in a non-bilaterian animal, the sea anemone Nematostella vectensis. We identified the complete set of FGF ligands and FGF receptors, of which two paralogous FGFs (NvFGFa1 and NvFGFa2) and one FGF receptor(NvFGFRa) are specifically coexpressed in the developing apical organ, a sensory structure located at the aboral pole of ciliated larvae from various phyla. Morpholino-mediated knockdown experiments reveal that NvFGFa1 and NvFGFRa are required for the formation of the apical organ, whereas NvFGFa2 counteracts NvFGFRa signalling to prevent precocious and ectopic apical organ development. Marker gene expression analysis shows that FGF signalling regulates local patterning in the aboral region. Furthermore,NvFGFa1 activates its own expression and that of the antagonistic NvFGFa2, thereby establishing positive- and negative-feedback loops. Finally, we show that loss of the apical organ upon NvFGFa1 knockdown blocks metamorphosis into polyps. We propose that the control of the development of sensory structures at the apical pole of ciliated larvae is an ancestral function of FGF signalling.
Mesh analysis for toroidal drive with roller teeth
Authors: Xu L , Huang Z
Published: April 2008

In the current paper, for the toroidal drive with roller teeth, its meshing equation, equations of the contact lines, the limit curves, the induced normal curvature, and the angle of the relative velocity vector to the contact line are determined. Using the equations, contact lines, meshing zones, limit curves, induced normal curvatures, and angles of the relative velocity vector to the contact line are calculated for two kinds of the toroidal drives with roller teeth, respectively. The results are compared with those for the toroidal drive with ball teeth. For the roller tooth surface of the drive, the distribution of the mesh parameters has given. The changes of the mesh parameters along with drive parameters have been investigated. The results are compared with those for the toroidal drive with ball teeth. The results are useful for design and manufacture of the toroidal drive.
Mode III crack problem in a functionally graded coating-homogeneous substrate structure
Authors: Ma L , Wu L-Z
Published: April 2008

The current paper describes an anti-plane problem for an internal crack and an edge crack perpendicular to the interface of a functionally graded coating-homogeneous substrate structure for the material whose properties are one-dimensionally dependent. Integral transform and dislocation density functions are employed to reduce the problem to a solution of a system of singular integral equations. Numerical results show the effect of the material gradient parameter and crack configuration on the stress intensity factors of the functionally graded coating-homogeneous substrate structure.
A time-varying stiffness rotor-active magnetic bearings system under parametric excitation
Authors: Hegazy U H , Amer Y A
Published: April 2008

The method of multiple scales is applied to investigate the non-linear oscillations and dynamic behaviour of a rotor-active magnetic bearings (AMBs) system, with time-varying stiffness. The rotor-AMB model is a two-degree-of-freedom non-linear system with quadratic and cubic non-linearities and parametric excitation in the horizontal and vertical directions. The case of principal parametric resonance is considered and examined. The steady-state response and the stability of the system at the principal parametric resonance case for various parameters are studied numerically, applying the frequency response function method. It is shown that the system exhibits many typical non-linear behaviours including multiple-valued solutions, jump phenomenon, hardening and softening non-linearity. Different effects of the system parameters on the non-linear response of the rotor are also reported. Results are compared with available published work.
The method for uncoupling design with the aid of systematic inventive thinking
Authors: Cai C-L , Xiao R-B
Published: April 2008

The independence axiom in axiomatic design (AD) states that the smaller functional dependency, the better system performance. This paper aims to develop an effective and widely applicable method for uncoupling design. First, the relationships, compatibilities, and possibility of integration between AD and systematic inventive thinking (SIT) are analysed. According to the analysis, a new uncoupling method based on SIT is proposed. Next, the detailed uncoupling steps of this method are explained and a strategy to upgrade an old system or develop new systems based on an existing one is proposed in terms of this uncoupling method. Then, an example of solving vibration and noise problem of flushing facility is used to illuminate this method. Finally, a discussion of the proposed uncoupling method and the possible extension of this method with theory of inventive problem solving (TRIZ) are presented. This proposed uncoupling method is different from the conventional approaches, which avoids measuring functional dependency, harmonizing parameters, or searching substitutable technological ideas.
Parallel numerical simulation with domain decomposition for the fluid-filled drum crash
Authors: Li Z , Jin X-L , Chen X-D
Published: April 2008

Fluid—structure interaction (FSI) problems simultaneously bring together some of the critical aspects associated with both fluid dynamics and structural dynamics. In this research, the simulation of the three-dimensional flexible fluid-filled drum in the crash is achieved through multi-material arbitrary Lagrangian-Eulerian (ALE) finite-element method because of its ability to control mesh geometry independently from geometry. The ALE description is adopted for the fluid domain, whereas for the structural domain the Lagrangian formulation is adopted. The computation of the FSI and the crash contact between the drum and the ground is realized by the penalty-based coupling method. Then the dynamic behaviour of the drum in the crash is analysed and the parallelism is discussed because the computation of the FSI and the crash contact is quite time-consuming. Based on domain decomposition, the recursive coordinate bisection (RCB) is improved according to the time-consuming characteristics of the fluid-filled container in the crash. The results indicate, in comparison with RCB method, the improved recursive coordinate bisection method has improved the speedup and the parallel efficiency.
Coordination of two crank angles and two acceleration poles for a slider crank mechanism using parametric equations
Authors: Hwang W-M , Fan Y-S
Published: April 2008

The current article presents the parametric equations for the synthesis of a slider crank mechanism with a coupler point passing through two specified acceleration poles that accord with two specified crank angles. The parametric equations for the coordinates of the acceleration pole for the coupler with respect to the frame are shown to be functions of only the geometric configuration of the slider crank mechanism driven by the crank with a constant rotational speed. Moreover, a necessary condition for the crank angular interval corresponding to the two acceleration poles on a coupler curve generated by a slider crank mechanism is investigated. The desired coupler point of a given mechanism passing through two acceleration poles should be a double point on the locus of the acceleration pole described on the coupler plane. The transformed parametric equations on the fixed plane are then applied to synthesize the desired mechanism with a coupler point passing through two specified acceleration poles that accord with two specified crank angles.
Development and bench-testing of a common rail system for dimethyl ether
Authors: Qian Y , Zuo C , Tan J , Xu H
Published: April 2008

Dimethyl ether (DME) offers great potential benefits in reducing exhaust emissions and improving the fuel economy of automotive engines, but it requires a different fuel system to deal with its physical properties. In the present study, a new electronically controlled common rail injection system was specially designed to resolve this issue. The mechanism and principle of this system was described in detail. Experimental work has been carried out to examine and improve matching of the fuel injection system on a fuel injection pump test bench. The results show that the orifice diameter in the three-way connector of the new fuel system has significant effects on injection performance, and a diameter of 0.3 mm has been proven to be most appropriate for the system. The effect of the pressure in the middle-pressure common rail (MPCR) on the injection characteristics has also been studied. When the pressure in the MPCR is 6.0 MPa, the present system has demonstrated good injection characteristics.
An approach to the selection of mechanism types in computer-aided conceptual design
Authors: Tang L
Published: April 2008

The selection of mechanism type is one of the important aspects in conceptual design of machine products. The paper applies the set theory for representing the attribute items of kinematic function to reflect the kinematic state and the function quality to reflect overall performances of the function unit for some complex design task. It gives a set-theory-based mode for the selection of mechanism types, in which precise reasoning by computer is combined with fuzzy appraisement by human. By precise reasoning at first, the computer selects from mechanisms database those mechanisms that can meet the kinematic requirements of the function unit to be solved. And then the function qualities of the selected mechanisms are appraised by human approving, which is actually a process of fuzzy match. This approach avoided the difficulty that the computer cannot yet effectively process fuzzy information and is suitable for the selection of both single-degree-of-freedom (DOF) and many-DOF mechanisms. The selected mechanisms can thus meet the requirements not only of the kinematic function, but also of the function quality. The approach presented in the current paper has been successfully applied to the software development of computer-aided conceptual design of mechanism systems.
Electromechanical-fluidic coupled dynamics for microbeams
Authors: Xu L , Jia X
Published: April 2008

In the current article an electromechanical-fluidic coupled dynamic model of the microbeam is presented and the electromechanical-fluidic coupled dynamic equations are obtained. Using the KBM method, the non-linear coupled dynamic equations are resolved. The explicit equations of the free vibrating displacements of the microbeam are given. Under free vibration, the equations of the electric field fluctuation and the air pressure fluctuation are also given. Besides this, the forced responses of the electromechanical-fluidic coupled system to voltage excitation are also analysed. Changes in the electromechanical-fluidic coupled vibrations along with mechanical, electric, and fluidic parameters are investigated.
Investigation of the wall friction in the pipe induced by the oscillating flow
Authors: Jia J H , Du J Y , Wang Y , Hua H X
Published: April 2008

The wall friction induced by the oscillating flow of the fractional derivative Maxwell viscoelastic fluid in the pipe is investigated. The velocity and the shear stress solutions of the flow are solved. The friction is derived from the shear stress expression and analysed by numerical simulation. From analysis, it is found that the friction amplitude exhibits resonance-like phenomena. Moreover, the number of the resonance-like peaks, the enhancement magnitude, and the resonance-like frequency of the same order vary with the pipe radius and rheological parameters of fluids. When the radius overtakes the critical value, the friction curve monotonously decreases, and when the radius is big enough, the enhancement disappears.
Effect of squeezing on porosity and wear behaviour of partially remelted A319/20 vol% SiCp metal matrix composites
Authors: Mahmoud T S , Mahmoud F H , Zakaria H M , Khalifa T A
Published: April 2008

This article describes the effect of the squeezing process on the porosity of partially remelted A319/20 vol% SiC particulate (SiCp) reinforced metal matrix composites (MMCs). The composite alloy was originally fabricated by a stir casting technique. The effect of squeezing process parameters such as the squeezing time, compressive stress, and the liquid weight fraction inside the melt on the overall porosity was extensively studied. Moreover, pin-on-disc wear tests were conducted to evaluate the effect of porosity on the wear resistance of the composites. It was found that the squeezed composites have lower overall porosity when compared with the as-cast composites. The lowest overall porosity content was observed when the squeezing process variables were at their peak values. After squeezing, the gas-bubble voids were practically eliminated, whereas the inter-particle voids were significantly reduced but not completely eliminated due to fracture of SiCp and generation of new inter-particle microvoids. Wear test results showed that the wear resistance of the squeezed composites was significantly higher than the as-cast composites due to the lower porosity content of the squeezed composites. The wear resistance of the squeezed composites depends significantly on the overall porosity. It has been found that the wear rate of the squeezed composites increase with increasing overall porosity.
Interval dynamic response analysis of structures with interval parameters
Authors: Gao W , Zhang N , Ma J , Wang X B
Published: April 2008

Dynamic response analysis of truss structures with interval parameters under interval loads are investigated using a new method called the interval factor method (IFM). Using the IFM, the structural physical parameters, geometric dimensions, and loads can be considered as interval variables. The structural stiffness and mass matrices can then, respectively, be described by the product of two parts corresponding to the deterministic matrix and the interval factors of structural parameters. The computational expressions for the midpoint value, lower and upper bounds of the structural dynamic responses are derived by means of the mode superposition method and interval operations. The influences of the uncertainty of the structural parameters and loads on the structural dynamic responses are demonstrated by using truss structures.
Use and husbandry of captive European starlings (Sturnus vulgaris) in scientific research: a review of current practice
Authors: Asher Lucy , Bateson Melissa
Published: April 2008

Summary

We reviewed the use of captive European starlings ( Sturnus vulgaris) in scientific research published between 2000 and 2004. We estimated the numbers of birds used and documented their origin and the range of husbandry regimes employed with the aim of comparing current practice with the new European guidelines for husbandry of laboratory animals. Over the five-year period, 106 primary articles report the use of an estimated total of 2490 captive starlings. The majority of birds were caught from the wild either as adults or fledglings, and only 3% were hand-reared from chicks. There was considerable variation in husbandry. In the majority of cases, standards fell below those currently recommended as best practice in the UK and cited in new European guidelines. The median volume of home cages employed was 0.42 m3 (0.13–5.1 m3, interquartile range), whereas current recommendations suggest a minimum of 1.0 m3 for a singly-housed bird. The median volume of space allowed per bird was 0.13 m3/bird (0.08–1.05 m3/bird, Q1–Q3), whereas current recommendations suggest a minimum of 0.33 m3/bird. Only 27% of the articles mentioned providing any form of environmental enrichment for birds in their home cages. We recommend that more research be conducted into the welfare of starlings to inform legislation and guidelines, and thus maximize the welfare of captive animals.
The effects of buprenorphine on behaviour in the ACI and BN rat inbred strains
Authors: Avsaroglu H , Sommer R , Hellebrekers L J , van Zutphen L F M , van Lith H A
Published: April 2008

Summary

Buprenorphine is a partial μ, κ agonist that has been shown to influence spontaneous behaviour in animals. Previously, we have demonstrated significant differences in the analgesic response to buprenorphine between the August Copenhagen Irish (ACI)/SegHsd and the Brown Norway (BN)/RijHsd inbred rat strains. The purpose of this study was to determine whether these strains also differed in their behavioural response to buprenorphine in order to provide an additional parameter for the genetic analysis and localization of genes involved in this response. Male and female rats of both strains were used ( n = 6/strain/sex) for this study. Each rat was subjected, respectively, to three treatment regimens at 15:00 h: (A) unchallenged; (B) intravenous saline; (C) intravenous buprenorphine (0.05 mg/kg) according to a crossover design. The relative duration (s/h) of locomotion, grooming, drinking and eating behaviour was subsequently determined from 15:30 to 07:00 h using the automatic registration system, Laboratory Animal Behaviour Registration and Analysis System™. Significant strain differences were observed in unchallenged behaviour between the ACI and the BN rats. ACI rats, but not BN rats, responded to buprenorphine treatment with decreased levels of locomotion, drinking and eating behaviour. The same treatment resulted in an increased grooming behaviour in both strains. Slight but significant sex differences were observed for locomotion and eating in the analysis of variance procedure, but did not reach the level of statistical significance in the multiple comparison procedure. The results of this study emphasize the possibility that strain-specific effects must be taken into account when using behavioural parameters for the assessment of the analgesic effects of buprenorphine in rats.
A small-scale, low-cost isolation system for the incubation and rearing of low bacterial load chicks as a model to study microbial–intestinal interactions
Authors: Forder Rebecca E A , Firth Gordon A , Tivey David R , Howarth Gordon S , Hughes Robert J
Published: April 2008

Summary

A small-scale, economical isolator system was adapted to hatch and raise chicks in a bacteria-free environment as a means to observe bacterial interactions with the intestinal mucosa during early development. The design and construction of flexible plastic isolators for incubation and brooding are described along with methodologies for preparation of eggs for entry into the isolators, incubation and hatching. Two trials were conducted, the first in August 2005 and the second in March 2006. Results from both trials showed no differences in body weights of chicks raised in isolation when compared with those raised conventionally. Growth of bacteria was detected from rectal swabs at day 2 post-hatch, with both trials, showing a light growth of Bacillus sp., coagulase-negative staphylococci and haemolytic streptococcus in trial 1, and a light growth of Bacillus cereus only in trial 2. Although not germfree, the growth of bacteria in chicks raised in isolation was decreased or absent when compared with chicks raised conventionally. Feed was negative for contamination and surface swabs of equipment were also negative until day 3 post-hatch, suggesting possible contamination within the eggs themselves. Despite the presence of bacterial species, the isolator system was successful in producing low bacterial load chicks for comparison studies with conventionally raised chicks.
Occurrence of headless sperms in adolescent rat urine
Authors: Shimomura Kazuhiro , Sakurai Ken , Shimada Makoto , Hagiwara Miyoko , Kato Michiyuki , Furuhama Kazuhisa
Published: April 2008

Summary

Increased incidence of headless sperms (HS) was spontaneously observed in the urine of adolescent naïve male SPF/VAF Crl:CD(SD) rats. To clarify the factors contributing to this event, the HS incidence in urine and the epididymis was periodically examined in conjunction with measurements of testis and epididymis weights, motility and morphology of sperms and testosterone, transferrin or follicle-stimulating hormone (FSH) concentrations in serum and/or the testis. The urinary HS incidence was 61%, 69%, 44%, 30%, 14%, 9% and 7% in 100 sperms counted at ages 8, 9, 10, 11, 12, 13 and 14 weeks, respectively; namely, HS peaked at 9 weeks, gradually decreased from 10 weeks and became almost a plateau from 12 weeks onwards. The epididymal HS incidence, which was lower than that in urine, peaked at 8 weeks, decreased from 10 weeks and became almost zero from 12 weeks. By scanning electron microscopy of HS in the epididymis, a narrow gap between the sperm head and neck was clearly seen along with the posterior ring. Concentrations of testicular testosterone and transferrin, a marker for Sertoli cell maturation, reached mature animal levels at 12 weeks. In contrast, no change in serum FSH concentration was seen throughout the study period. These results demonstrate that a marked increase in urinary HS incidence in naïve rats at ages 8–11 weeks would be a physiological phenomenon seen in connection with the process of Sertoli cell maturation.
Nucleoside modifications modulate activation of the protein kinase PKR in an RNA structure-specific manner
Authors: Nallagatla Subba Rao , Bevilacqua Philip C.
Published: April 2008

The human interferon-induced protein kinase PKR is a key component of innate immunity, a process in which it senses pathogenic RNA. PKR consists of an N-terminal dsRNA-binding domain (dsRBD) and a C-terminal kinase domain. Upon binding long (>33 base pairs) stretches of pathogenic dsRNA, PKR undergoes autophosphorylation, which activates it to phosphorylate eIF2α, leading to inhibition of translation initiation. Many cellular and viral transcripts contain nucleoside modifications, and these could affect PKR activation. For example, a 5′-triphosphate confers the ability of relatively unstructured transcripts to activate PKR. Effects of internal RNA modifications on PKR activation have not been reported. Herein, PKR activation by ssRNA and dsRNA containing internal nucleobase, sugar, and phosphodiester modifications is analyzed. We find that for 5′-triphosphate-containing ssRNA, most base and sugar modifications abrogate activation, although 2′-fluoro-modified ssRNA does not, indicative of a critical role for hydrogen bonding at the ribose sugar. In the case of dsRNA, a more limited set of nucleoside modifications affect PKR activation. Watson–Crick base-pairing is required for activation, and some minor groove modifications abrogate activation while major groove modifications have little effect. Surprisingly, GU wobble pairs also largely abrogate dsRNA-mediated activation when present at modest levels. Modifications to dsRNA that abrogate activation have no significant effect on dsRBD binding, allowing such RNAs to act as inhibitors and suggesting a nonequivalence of binding ability and activation. Overall, the findings indicate that nucleoside modifications and wobble pairing may serve to discriminate self-RNA and pathogenic RNA in innate immunity.
miRDB: A microRNA target prediction and functional annotation database with a wiki interface
Authors: Wang Xiaowei
Published: April 2008

MicroRNAs (miRNAs) are short noncoding RNAs that are involved in the regulation of thousands of gene targets. Recent studies indicate that miRNAs are likely to be master regulators of many important biological processes. Due to their functional importance, miRNAs are under intense study at present, and many studies have been published in recent years on miRNA functional characterization. The rapid accumulation of miRNA knowledge makes it challenging to properly organize and present miRNA function data. Although several miRNA functional databases have been developed recently, this remains a major bioinformatics challenge to miRNA research community. Here, we describe a new online database system, miRDB, on miRNA target prediction and functional annotation. Flexible web search interface was developed for the retrieval of target prediction results, which were generated with a new bioinformatics algorithm we developed recently. Unlike most other miRNA databases, miRNA functional annotations in miRDB are presented with a primary focus on mature miRNAs, which are the functional carriers of miRNA-mediated gene expression regulation. In addition, a wiki editing interface was established to allow anyone with Internet access to make contributions on miRNA functional annotation. This is a new attempt to develop an interactive community-annotated miRNA functional catalog. All data stored in miRDB are freely accessible at http://mirdb.org.
Cognitive Ethology for humans: Inconvenient truth or attentional deficit?
Authors: Sebanz Natalie , Knoblich Guenther , Humphreys Glyn W.
Published: April 2008

We discuss Kingstone et al.'s target article in the light of emerging work on cognitive ethology.
Healthy and unhealthy dependence: Implications for major depression
Authors: Schulte Fiona S. , Mongrain Myriam , Flora David B.
Published: April 2008

Objectives

To examine the contribution of varying levels of dependency to Axis I and Axis II disorders, and to the recurrence of major depression in a graduate student sample diagnosed with a history of the disorder.

Methods

At Time 1, participants were interviewed to confirm a current or past episode of major depression along with the presence of Axis II and other current or past Axis I disorders. Various measures of dependency were administered including the Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976), the 3‐Vector Dependency Inventory (3VDI; Pincus & Gurtman, 1995), and the Personal Style Inventory (PSI; Robins et al., 1994). Participants were interviewed 20 months later to determine the recurrence of a depressive episode.

Results

A factor analysis conducted on scale scores for each dependency measure resulted in three factors labelled ‘unhealthy’, ‘intermediate’, and ‘healthy’ dependence. Controlling for history of major depression, structural equation modelling found ‘unhealthy’ dependence to be the only predictor of recurrences of major depression and Axis II disorders, while ‘healthy’ dependence was related to fewer depressive symptoms.

Conclusions

These results have important implications for the conceptualization of the dependency construct.