bluuebunny/crossref_metadata_2025 huggingface dataset:
Hematopoietic stem cells exhibit a specific ABC transporter gene expression profile clearly distinct from other stem cells
Authors: Tang Leilei , Bergevoet Saskia M , Gilissen Christian , de Witte Theo , Jansen Joop H , van der Reijden Bert A , Raymakers Reinier AP
Published: September 2010

Background

ATP-binding cassette (ABC) transporters protect cells against unrelated (toxic) substances by pumping them across cell membranes. Earlier we showed that many ABC transporters are highly expressed in hematopoietic stem cells (HSCs) compared to more committed progenitor cells. The ABC transporter expression signature may guarantee lifelong protection of HSCs but may also preserve stem cell integrity by extrusion of agents that trigger their differentiation. Here we have studied whether non-hematopoietic stem cells (non-HSCs) exhibit a similar ABC transporter expression signature as HSCs.

Results

ABC transporter expression profiles were determined in non-hematopoietic stem cells (non-HSCs) from embryonic, neonatal and adult origin as well as in various mature blood cell types. Over 11,000 individual ABC transporter expression values were generated by Taqman Low Density Arrays (TLDA) to obtain a sensitivity comparable with quantitative real-time polymerase chain reactions. We found that the vast majority of transporters are significantly higher expressed in HSCs compared to non-HSCs. Furthermore, regardless their origin, non-HSCs exhibited strikingly similar ABC transporter expression profiles that were distinct from those in HSCs. Yet, sets of transporters characteristic for different stem cell types could be identified, suggesting restricted functions in stem cell physiology. Remarkably, in HSCs we could not pinpoint any single transporter expressed at an evidently elevated level when compared to all the mature blood cell types studied.

Conclusions

These findings challenge the concept that individual ABC transporters are implicated in maintaining stem cell integrity. Instead, a distinct ABC transporter expression signature may be essential for stem cell function. The high expression of specific transporters in non-HSCs and mature blood cells suggests a specialized, cell type dependent function and warrants further functional experiments to determine their exact roles in cellular (patho)physiology.
Genome-scale identification of Soybean BURP domain-containing genes and their expression under stress treatments
Authors: Xu Hongliang , Li Yaxuan , Yan Yueming , Wang Ke , Gao Ya , Hu Yingkao
Published: September 2010

Background

Multiple proteins containing BURP domain have been identified in many different plant species, but not in any other organisms. To date, the molecular function of the BURP domain is still unknown, and no systematic analysis and expression profiling of the gene family in soybean (Glycine max) has been reported.

Results

In this study, multiple bioinformatics approaches were employed to identify all the members of BURP family genes in soybean. A total of 23 BURP gene types were identified. These genes had diverse structures and were distributed on chromosome 1, 2, 4, 6, 7, 8, 11, 12, 13, 14, and 18. Phylogenetic analysis suggested that these BURP family genes could be classified into 5 subfamilies, and one of which defines a new subfamily, BURPV. Quantitative real-time PCR (qRT-PCR) analysis of transcript levels showed that 15 of the 23 genes had no expression specificity; 7 of them were specifically expressed in some of the tissues; and one of them was not expressed in any of the tissues or organs studied. The results of stress treatments showed that 17 of the 23 identified BURP family genes responded to at least one of the three stress treatments; 6 of them were not influenced by stress treatments even though a stress related cis-element was identified in the promoter region. No stress related cis-elements were found in promoter region of any BURPV member. However, qRT-PCR results indicated that all members from BURPV responded to at least one of the three stress treatments. More significantly, the members from the RD22-like subfamily showed no tissue-specific expression and they all responded to each of the three stress treatments.

Conclusions

We have identified and classified all the BURP domain-containing genes in soybean. Their expression patterns in different tissues and under different stress treatments were detected using qRT-PCR. 15 out of 23 BURP genes in soybean had no tissue-specific expression, while 17 out of them were stress-responsive. The data provided an insight into the evolution of the gene family and suggested that many BURP family genes may be important for plants responding to stress conditions.
Analysis of human synovial and bone marrow mesenchymal stem cells in relation to heat-inactivation of autologous and fetal bovine serums
Authors: Nimura Akimoto , Muneta Takeshi , Otabe Koji , Koga Hideyuki , Ju Young-Jin , Mochizuki Tomoyuki , Suzuki Koji , Sekiya Ichiro
Published: September 2010

Background

Though sera are essential for Mesenchymal stem cells (MSCs), the effect of heat-inactivation remains unknown. Autologous human serum is recommended for clinical use; however, it is unclear whether differentiation potentials are maintained. To examine whether heat-inactivation of serum affected the proliferation and whether autologous human serum influenced their multipotentiality.

Methods

After whole blood collection, human synovium and bone marrow were harvested. Nucleated cells were expanded with autologous human serum and FBS.

Results

Heat-inactivation of autologous human serum enhanced proliferation of synovial MSCs. Heat-inactivation of each types of serum didn't affect calcification of synovial MSCs. The induction of calcification increased ALP activity, with the exception of bone marrow MSCs with autologous human serum. For adipogenesis of synovial MSCs, the Oil Red-O positive colony forming efficiency with autologous human serum was similar to or less than that with FBS.

Conclusion

These clarified the processing of human autologous serum and the influence of different sera for differentiation of synovial and bone marrow MSCs.
Studies of Anopheles gambiae s.l (Diptera: Culicidae) exhibiting different vectorial capacities in lymphatic filariasis transmission in the Gomoa district, Ghana
Authors: Amuzu Hilaria , Wilson Michael D , Boakye Daniel A
Published: September 2010

Background

Two lymphatic filariasis endemic communities Mampong and Hwida in Ghana have been regularly monitored for impact on transmission after annual mass drug administration (MDA) with albendazole and ivermectin. After six MDAs even though the ABR for Mampong was 55883/person/year and that of Hwida was 2494/person/year, they both had ATPs of 15.21 infective larvae/person/year. Interestingly the human microfilaraemia levels had reduced significantly from 14% to 0% at Mampong and 12% to 3% at Hwida. In an attempt to understand this anomaly, we collected mosquitoes over a 5-month period using human landing catches to determine the species composition, the number of cibarial teeth, the lengths and widths of the cibarium and the cibarial dome of the vector populations.

Results

Out of 2553 mosquitoes caught at Mampong, 42.6% were An. gambiae s.l. All 280 identified further by PCR were An. gambiae s.s (275 M and 5 S molecular forms). At Hwida, 112 mosquitoes were obtained; 67 (59.8%) were An. gambiae s.l, comprised of 40 (59.7%) An. melas, 24 (35.8%) An. gambiae s.s (17 and 5 M and S molecular forms respectively) and 3 (4.5%) unidentified. The mean number of teeth for An. melas was 14.1 (median = 14, range = 12-15), An. gambiae s.s., 15.7 (median = 15, range = 13-19) M form 15.5 (median = 15 range = 13-19) and S form 16 (median = 16, range 15-17). The observed differences in teeth numbers were significantly different between An. melas and An. gambiae s.s (p = 0.004), and the M form (p = 0.032) and the S form (p = 0.002).

Conclusions

In this study, An. gambiae s.s was the main vector at Mampong and was found to possess significantly more cibarial teeth than An. melas, the principal vector at Hwida. We postulate that the different impact observed after 6 MDAs may be due to An. gambiae s.s exhibiting 'facilitation' at Mampong and at Hwida An. melas the main vector exhibits 'limitation'. Thus it may be necessary to compliment MDA with vector control to achieve interruption of transmission in areas where An. melas may exhibit limitation.
Emerging role of radiation induced bystander effects: Cell communications and carcinogenesis
Authors: Baskar Rajamanickam
Published: September 2010

Ionizing radiation is an invaluable diagnostic and treatment tool used in various clinical applications. On the other hand, radiation is a known cytotoxic with a potential DNA damaging and carcinogenic effects. However, the biological effects of low and high linear energy transfer (LET) radiations are considerably more complex than previously thought. In the past decade, evidence has mounted for a novel biological phenomenon termed as "bystander effect" (BE), wherein directly irradiated cells transmit damaging signals to non-irradiated cells thereby inducing a response similar to that of irradiated cells. BE can also be induced in various cells irrespective of the type of radiation, and the BE may be more damaging in the longer term than direct radiation exposure. BE is mediated either through gap-junctions or via soluble factors released by irradiated cells. DNA damage response mechanisms represent a vital line of defense against exogenous and endogenous damage caused by radiation and promote two distinct outcomes: survival and the maintenance of genomic stability. The latter is critical for cancer avoidance. Therefore, efforts to understand and modulate the bystander responses will provide new approaches to cancer therapy and prevention. This review overviews the emerging role of BE of low and high LET radiations on the genomic instability of bystander cells and its possible implications for carcinogenesis.
Assessment of myocardial abnormalities in rheumatoid arthritis using a comprehensive cardiac magnetic resonance approach: a pilot study
Authors: Kobayashi Yasuyuki , Giles Jon T , Hirano Masaharu , Yokoe Isamu , Nakajima Yasuo , Bathon Joan M , Lima Joao AC , Kobayashi Hitomi
Published: September 2010

Introduction

Rheumatoid arthritis (RA) is a multi-organ inflammatory disorder associated with high cardiovascular morbidity and mortality. We sought to assess cardiac involvement using a comprehensive cardiac magnetic resonance imaging (cMRI) approach and to determine its association with disease characteristics in RA patients without symptomatic cardiac disease.

Methods

RA patients with no history and/or clinical findings of systemic or pulmonary hypertension, coronary artery disease, severe valvular heart disease, atrial fibrillation, diabetes mellitus, or echocardiographic abnormalities underwent contrast-enhanced cMRI on a 1.5T scanner. Adenosine triphosphate was used to assess perfusion defects due to microvascular impairment or ischemia, and delayed enhanced imaging was obtained for the assessment of myocardial inflammation/fibrosis. We explored the associations of cMRI abnormalities with RA disease activity and severity measures.

Results

Eighteen patients (78% female) with a mean age of 57 ± 10 years were studied. Eight patients (45%) demonstrated a myocardial abnormality. Perfusion defects under pharmacologic stress were seen in two patients (11%), one of whom had a circumferential subendocardial perfusion defect and one had a non-segmental subendocardial perfusion defect. Seven patients (39%) were found to have delayed enhancement, only one of whom also demonstrated a perfusion defect. Mean disease activity score (DAS)28 was significantly higher in the group with delayed enhancement compared to the group without by an average of 1.32 DAS28 units (4.77 vs. 3.44 units, respectively; P = 0.011). Corresponding trends to statistical significance were noted in systemic inflammatory markers, with both C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) quantitatively higher in the group with delayed enhancement. Other RA characteristics, such as disease duration, autoantibody status, and current treatments were not significantly associated with cardiac involvement.

Conclusions

Myocardial abnormalities, as detected by cMRI, were frequent in RA patients without known cardiac disease. Abnormal cMRI findings were associated with higher RA disease activity, suggesting a role for inflammation in the pathogenesis of myocardial involvement in RA.
The pregnancy hormones human chorionic gonadotropin and progesterone induce human embryonic stem cell proliferation and differentiation into neuroectodermal rosettes
Authors: Gallego Miguel J , Porayette Prashob , Kaltcheva Maria M , Bowen Richard L , Vadakkadath Meethal Sivan , Atwood Craig S
Published: September 2010

Introduction

The physiological signals that direct the division and differentiation of the zygote to form a blastocyst, and subsequent embryonic stem cell division and differentiation during early embryogenesis, are unknown. Although a number of growth factors, including the pregnancy-associated hormone human chorionic gonadotropin (hCG) are secreted by trophoblasts that lie adjacent to the embryoblast in the blastocyst, it is not known whether these growth factors directly signal human embryonic stem cells (hESCs).

Methods

Here we used hESCs as a model of inner cell mass differentiation to examine the hormonal requirements for the formation of embryoid bodies (EB's; akin to blastulation) and neuroectodermal rosettes (akin to neurulation).

Results

We found that hCG promotes the division of hESCs and their differentiation into EB's and neuroectodermal rosettes. Inhibition of luteinizing hormone/chorionic gonadotropin receptor (LHCGR) signaling suppresses hESC proliferation, an effect that is reversed by treatment with hCG. hCG treatment rapidly upregulates steroidogenic acute regulatory protein (StAR)-mediated cholesterol transport and the synthesis of progesterone (P4). hESCs express P4 receptor A, and treatment of hESC colonies with P4 induces neurulation, as demonstrated by the expression of nestin and the formation of columnar neuroectodermal cells that organize into neural tubelike rosettes. Suppression of P4 signaling by withdrawing P4 or treating with the P4-receptor antagonist RU-486 inhibits the differentiation of hESC colonies into EB's and rosettes.

Conclusions

Our findings indicate that hCG signaling via LHCGR on hESC promotes proliferation and differentiation during blastulation and neurulation. These findings suggest that trophoblastic hCG secretion and signaling to the adjacent embryoblast could be the commencement of trophic support by placental tissues in the growth and development of the human embryo.
Place of Death: Correlations With Quality of Life of Patients With Cancer and Predictors of Bereaved Caregivers' Mental Health
Authors: Wright Alexi A. , Keating Nancy L. , Balboni Tracy A. , Matulonis Ursula A. , Block Susan D. , Prigerson Holly G.
Published: September 2010

Purpose

To determine whether the place of death for patients with cancer is associated with patients' quality of life (QoL) at the end of life (EOL) and psychiatric disorders in bereaved caregivers.

Patients and Methods

Prospective, longitudinal, multisite study of patients with advanced cancer and their caregivers (n = 342 dyads). Patients were followed from enrollment to death, a median of 4.5 months later. Patients' QoL at the EOL was assessed by caregiver report within 2 weeks of death. Bereaved caregivers' mental health was assessed at baseline and 6 months after loss with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and the Prolonged Grief Disorder interview.

Results

In adjusted analyses, patients with cancer who died in an intensive care unit (ICU) or hospital experienced more physical and emotional distress and worse QoL at the EOL (all P ≤ .03), compared with patients who died at home with hospice. ICU deaths were associated with a heightened risk for posttraumatic stress disorder, compared with home hospice deaths (21.1% [four of 19] v 4.4% [six of 137]; adjusted odds ratio [AOR], 5.00; 95% CI, 1.26 to 19.91; P = .02), after adjustment for caregivers' preexisting psychiatric illnesses. Similarly, hospital deaths were associated with a heightened risk for prolonged grief disorder (21.6% [eight of 37] v 5.2% [four of 77], AOR, 8.83; 95% CI, 1.51 to 51.77; P = .02), compared with home hospice deaths.

Conclusion

Patients with cancer who die in a hospital or ICU have worse QoL compared with those who die at home, and their bereaved caregivers are at increased risk for developing psychiatric illness. Interventions aimed at decreasing terminal hospitalizations or increasing hospice utilization may enhance patients' QoL at the EOL and minimize bereavement-related distress.
Inventory Control with Generalized Expediting
Authors: Huggins Eric Logan , Olsen Tava Lennon
Published: September 2010

We consider a single-item, periodic-review inventory control problem in which discrete stochastic demand must be satisfied. When shortages occur, the unmet demand must be filled by some form of expediting; we allow a very general form for the cost structure of expediting. We explicitly consider the case where expedited production is allowed to produce up to a positive inventory level. We also consider the case where expedited production beyond the deficit is not permitted; an alternate application for this model is an inventory system with general lost sales costs. For the infinite-horizon discounted problem, we characterize the structure of the optimal stationary expediting policy and show that an (s, S) policy is optimal for regular production. For the special cases where the expediting cost function is concave or consists of a fixed and linear per-unit cost, we show that the optimal stationary expediting policy is generalized (s, S) or order-up-to, respectively. A numerical study allows us to gain insight into when expediting above and beyond the deficit is cost-effective.
A Computable Plug-In Estimator of Minimum Volume Sets for Novelty Detection
Authors: Park Chiwoo , Huang Jianhua Z. , Ding Yu
Published: September 2010

A minimum volume set of a probability density is a region of minimum size among the regions covering a given probability mass of the density. Effective methods for finding the minimum volume sets are very useful for detecting failures or anomalies in commercial and security applications—a problem known as novelty detection. One theoretical approach of estimating the minimum volume set is to use a density level set where a kernel density estimator is plugged into the optimization problem that yields the appropriate level. Such a plug-in estimator is not of practical use because solving the corresponding minimization problem is usually intractable. A modified plug-in estimator was proposed by Hyndman in 1996 to overcome the computation difficulty of the theoretical approach but is not well studied in the literature. In this paper, we provide theoretical support to this estimator by showing its asymptotic consistency. We also show that this estimator is very competitive to other existing novelty detection methods through an extensive empirical study.
Fast Algorithms for Specially Structured Minimum Cost Flow Problems with Applications
Authors: Vaidyanathan Balachandran , Ahuja Ravindra K.
Published: September 2010

The objective of the classical minimum cost flow problem is to send units of a good that reside at one or more points in a network (sources or supply nodes) with arc capacities to one or more other points in the network (sinks or demand nodes), incurring minimum cost. We develop fast algorithms for previously unstudied specially structured minimum cost flow problems that have applications in many areas, such as locomotive and airline scheduling, repositioning of empty rail freight cars, highway and river transportation, congestion pricing, shop loading, and production planning. First, we consider the case where the n1 supply and n2 demand nodes lie on a circle (or line) (n = n1 + n2) and flow is allowed only in one direction; our algorithm solves this problem in O(n) time. Next, we consider a constrained version of this problem and show that it can be solved in O(n log n2) time. Finally, we consider the version where the nodes lie on a circle (or line), flow is allowed in both directions, and the costs of flow between two nodes in the clockwise and the counterclockwise direction are different; our algorithm solves this problem in O(n log n) time. Our algorithms are based on the successive shortest-path algorithm for the minimum cost flow problem. We exploit the special structure of the problem and use advanced data structures, when required, to achieve short run times.
Differential expression of angiotensin II type 1 and type 2 receptors at the maternal–fetal interface: potential roles in early placental development
Authors: Tower C L , Lui S , Charlesworth N R , Smith S D , Aplin J D , Jones R L
Published: September 2010

Angiotensin II (Ang II) is locally generated in the placenta and regulates syncytial transport, vascular contractility and trophoblast invasion. It acts through two receptor subtypes, AGTR1 and AGTR2 (AT1 and AT2), which typically mediate antagonising actions. The objectives of this study are to characterise the cellular distribution of AGTR1 and AGTR2 at the maternal–fetal interface and explore the effects on cytotrophoblast turnover. Low levels ofAGTR2mRNA were detected in first trimester placental homogenates using real-time PCR. Immunohistochemistry using polyclonal antibodies against AGTR1 and AGTR2 detected the receptors in first trimester placenta, decidua basalis and villous tip outgrowths in culture. Serial staining with cytokeratin-7 was used to identify extravillous trophoblasts (EVTs). AGTR1 was found in the syncytiotrophoblast microvillous membrane, in a subpopulation of villous cytotrophoblasts, and in Hofbauer cells. AGTR1 was strongly upregulated in cytotrophoblasts in cell columns and villous tip outgrowths, but was absent in interstitial and endovascular EVTs within the decidua. AGTR2 immunostaining was present in Hofbauer cells and villous cytotrophoblasts, but was absent from syncytiotrophoblast. Faint staining was detected in cell column cytotrophoblasts and villous outgrowths, but not in EVTs within the decidua. Both receptors were detected in placental homogenates by western blotting. Ang II significantly increased proliferation of cytotrophoblasts in both villous explants and villous tip outgrowths, but did not affect apoptosis. Blockade of AGTR1 and AGTR2 together abrogated this effect. This study shows specific expression patterns for AGTR1 and AGTR2 in distinct trophoblast populations at the maternal–fetal interface and suggests that Ang II plays a role in placental development and generation of EVTs.
An upper-bound solution for the undrained bearing capacity of strip footings at the top of a slope
Authors: GEORGIADIS K.
Published: September 2010

An analytical upper-bound plasticity solution is presented for the calculation of the undrained bearing capacity of strip footings on or near slopes. Typical results, presented in terms of the undrained bearing capacity factor, are shown to be in excellent agreement with finite-element analysis results and generally more conservative than those obtained from other available solutions. The proposed upper-bound solution is used to investigate the influence of the slope angle, the distance of the footing from the slope, the footing width and the soil properties on the undrained bearing capacity.
Modelling time-dependent behaviour of Murro test embankment
Authors: KARSTUNEN M. , YIN Z.-Y.
Published: September 2010

This paper investigates the time-dependent behaviour of Murro test embankment in Finland. The embankment was built in 1993 on a soft natural clay deposit, which exhibits large strain anisotropy, destructuration and viscosity. The study is based on extensive experimental data from triaxial and oedometer tests on intact and reconstituted soil samples which shed light on the influence of time on mechanical properties, including testing designed for studying soil anisotropy and destructuration. The interpretation of the results is done in the framework of a recently developed elasto-viscoplastic model EVP-SCLAY1S, which is used to simulate the soft soil deposit coupled with Biot's consolidation theory. The determination of model parameters from the test results demonstrates that the model can be relatively easily used for practical applications. Using these parameters, two-dimensional finite-element analyses have been made as large deformation analysis. The comparisons between calculations and measurements demonstrate that the proposed model can be satisfactorily used to describe the time-dependent behaviour of the embankment on structured clay.
Evaluation of the viscous behaviour of clay using generalised overstress viscoplastic theory
Authors: QU G. , HINCHBERGER S.D. , LO K.Y.
Published: September 2010

In this paper, generalised elastic-viscoplastic (EVP) theory combined with a power law is used to derive simplified equations relating undrained shear strength and preconsolidation pressure to strain rate. An additional equation is derived relating the strain-rate parameter in EVP theory to the secondary compression index. The derived equations are used to evaluate the rate-sensitive and drained creep response of 20 clays reported in the literature. The evaluation shows strong evidence that the rate-sensitivity and time-dependency of clay in compression can be described simultaneously using the generalised EVP theory and power law. In addition, the constitutive parameter governing rate-sensitivity in EVP theory appears to be unique for constant rate-of-strain tests such as undrained triaxial compression and drained oedometer compression as well as stress controlled tests such as drained oedometer creep. To conclude, an approach to select the viscous parameters for clay is provided.
A dynamical systems-based approach to soil shear
Authors: JOSEPH P.G.
Published: September 2010

This note models monotonic soil shear as a dynamical system. It provides additional information to support the hypothesis that for monotonic soil shear, the rates of change of the shear stress, effective normal stress and void ratio are proportional to the applied shear and effective normal stresses with the proportionality values decaying with strain to become zero at the steady-state condition. This hypothesis provides close fits to stress–strain–void ratio curves from undrained shear tests of uncemented, resedimented clays and drained shear tests of uncemented sands and silts, using triaxial and true-triaxial equipment, and various stress paths. For undrained shear, model parameters vary smoothly with over-consolidation ratio; for drained shear, they vary in an orderly way with relative density. The model's value lies in that a well-formed hypothesis, derived from the steady-state condition, provides a simple, alternative approach to current complex elastoplastic models based on critical state theory.
Mechanics of SFRC under tension, part II: experimental validation
Authors: Ghosh S. , Bhattacharjya S. , Chakraborty S.
Published: September 2010

This is the second of a two-part paper involving a fundamental study of the tensile stress–strain relationship of short-fibre-reinforced concrete under tension. The validation of the analytical model developed in the first part is presented here. The tensile stress–strain results obtained from the theoretical model are compared with the results obtained from the experimental investigations for a wide range of fibre lengths, diameters and volume fractions. The results of the present model are also compared with the tensile stress–strain results obtained from the existing literature. The tensile stress–strain results obtained from the proposed theoretical predictions are found to be in good agreement with the experimental results. The predictability of the analytical approach is also scrutinised for peak load, load at ultimate deformation, ductility and so on. The analytical results show a good conformity, with respect to peak load, toughness and the natures of the ascending as well as descending branches.
Yield curvature for seismic design of circular reinforced concrete columns
Authors: Sheikh M.Neaz , Tsang H.H. , McCarthy T.J. , Lam N.T.K.
Published: September 2010

Significant research efforts have been devoted in recent years to the development of displacement-based seismic assessment and design methodology, recognising the shortcomings of traditional, code-specified force-based procedures. Recent advances in direct displacement-based seismic design of columns rely on the estimates of yield curvature for determining seismic design forces to satisfy the specified seismic performance levels. This paper presents simple expressions for estimating the effective yield curvature for normal- and high-strength circular reinforced concrete columns based on moment–curvature analyses of a large number of column sections. Such expressions can be programmed into spreadsheet format and can be used for the direct displacement-based design of circular reinforced concrete columns. Influences of different parameters on the effective yield curvature have been quantified. Effective yield curvature is presented in terms of the gross diameter of the section and the yield strain of longitudinal reinforcement together with three modification factors that take into account the effects of the strength of concrete, axial load ratio and the amount of longitudinal reinforcement. An example illustrating the preliminary design of bridge columns based on the developed expressions is presented.
Evaluation of powdered glass cullet as a means of controlling harmful alkali–silica reaction
Authors: Dyer T.D. , Dhir R.K.
Published: September 2010

It has been proposed that glass derived from container glass recovery can act to control harmful alkali–silica reaction in concrete when included in powdered form. However, the high sodium content of the material raises concerns about whether the release of this element could ultimately exacerbate the reaction. This paper reports on a study carried out on concrete mixes containing aggregate combinations known to undergo harmful alkali–silica reaction in combination with powdered glass, to establish its efficacy at controlling alkali–silica reaction. Glass suppressed expansion for a finite period of time, before expansion reached levels similar to or greater than the controls. It is therefore concluded that the use of powdered container glass is not suitable for controlling alkali–silica reaction. However, it is proposed that the sodium contribution from container glass is, in many cases, irrelevant, since the alkali contributions from the reactive aggregate combinations themselves appear to outweigh those from the glass.
Visual vs. quantitative electroencephalographic analysis in patients with and without posttraumatic epilepsy
Authors: Ljesevic Biljana , Martinovic Zarko , Popovic Mirjana , Jovic Stevan
Published: September 2010

Introduction. We investigated traces of EEG records from two groups of patients with brain trauma: with and without posttraumatic epilepsy (PTE) with respect to the control group by means of two methods: visual and quantitative EEG (QEEG) analysis. The aim of this study was to compare these methods in their sensibility for traumatic and epileptic alterations of the brain tissue in the two experimental conditions: after hyperventilation (HV) and after photo stimulation (FS), and in regard to the basic condition. Material and methods. 36 patients with PTE and 33 without PTE, and the control group of 34 healthy subjects participated in this study. EEG was registered in three 1-min epochs: before activation, after HV, and after FS on digital 32-channel EEG apparatus XLTEK. Mean amplitudes were calculated in 10 frequency ranges from 0 to 30 Hz on projections F7-C3, T5-O1, F8-C4 and T6-O2 from 16-s segments without artefacts. Data evaluation was performed using program package PERSYST Insight II (Persyst Development Co). Statistical package GRAPH-PAD was used for ANOVA test and Bonferroni post-test. Results. Visual analysis used to distinguish between normal EEG, with pathological alterations, non-epileptiforni and epileptiform transients showed that there was no statistically significant difference between patients with and without post-traumatic epilepsy. On the contrary, QEEG of registered epochs before activation, after HV and after PS showed statistically significant differences between the control group and the patients without PTE and with PTE. Conclusion. These results indicate that quantitative, analysis provides more subtle data about electrophysiological alterations after traumatic brain injury, which leads to better classification of patients.
Takotsubo cardiomyopathy: Report of the first case series in Serbia and review of the literature
Authors: Putnikovic Biljana , Cvorovic Vojkan , Panic Milos , Milicevic Predrag , Vojinovic-Maglic Gordana , Neskovic Aleksandar
Published: September 2010

Introduction. Takotsubo cardiomyopathy is a relatively novel cardiac syndrome that is characterized by transient left ventricular asynergy involving apical and mid-ventricular segments. Epidemiology and pathophisiology. It occurs predominantly in elderly women in the absence of obstructive coronary artery disease and is usually associated with severe emotional or physical stress. This syndrome is manifested with chest pain, electrocardiographic changes that mimic acute myocardial infarction, and minimal myocardial enzy?matic release. Several different mechanisms have been proposed: coronary artery spasm, dynamic left ventricular outflow/intracavitary obstruction, coronary microvascular dysfunction and direct catecholamine-mediated cardiomyocite injury. Therapy and prognosis. Complete recovery usually occurs after dramatic presentation, frequently complicated with acute heart failure. Therapy is empiric and directed towards supportive measures against cardiogenic shock, acute heart failure, dysrhythmias. In-hospital mortality rate is less than 1%, but long-term prognosis is still unknown. In addition to the review of the literature on takotsubo cardiomyopathy, we present the first series of patients with this syndrome detected in Clinical Hospital Center Zemun.
Novel benzopyranopyridine derivatives of 2-amino-3-formylchromone
Authors: Siddiqui Zeba , Praveen Shagufta , Farooq Farheen
Published: September 2010

Enol lactones such as 4-hydroxy-6-methyl-2H-pyran-2-one (triacetic acid lactone, TAL) and 4-hydroxycoumarin when treated with 2-amino-3-formylchromone under basic conditions afforded 3-acetoacetyl benzopyranopyridones and benzopyranopyridines, respectively. A series of pyrazole derivatives was prepared by the reaction of 3-acetoacetyl benzopyranopyridones with different hydrazines. All compounds were characterised on the basis of spectral data and their antibacterial activity evaluated.
Thermo-physical properties of silver/carbon fibre composites
Authors: Edtmaier Christian , Hula Robert Christian
Published: September 2010

Silver matrix composites with short and long carbon fibres of high intrinsic thermal conductivity were fabricated either by liquid metal infiltration or electroless deposition of the Ag matrix and subsequent hot pressing. Active elements enhancing the bonding between inclusions and matrix were introduced by pre-conditioning the fibres thus to influence and improve the overall thermo-physical properties of the composites. The evolution of the composite thermal conductivity (κc) and the coefficient of thermal expansion (αc) as a function of the fibre volume fraction, fibre type, fibre length (fibre orientation) and the presence of active elements such as cobalt, molybdenum, nickel, tungsten and boron are presented in detail and compared with different analytical models.
Influence of reinforcement contiguity on the thermal expansion of alumina particle reinforced aluminium composites
Authors: Roudini Ghodratollah , Tavangar Reza , Weber Ludger , Mortensen Andreas
Published: September 2010

Pore-free composites combining alumina particles within a matrix of pure aluminium are produced by pressure infiltration, varying systematically the degree of the contiguity, β, of the ceramic phase by sintering prior to infiltration. The thermal expansion of these composites is characterized using repeated cycling in a dilatometer from 303 to 543 K. The initial composite thermal expansion measured immediately after changing the sign of the temperature–time function conforms with predictions from thermoelasticity. Upon further temperature excursion, upward deviations from thermoelastic predictions are found; these are attributed to the influence of matrix plasticity, the influence of which decreases as β increases. The composite thermal expansion travels across 80 % of the theoretical range of initial thermoelastic values as β increases from 0 to 0.123, leading to the conclusion that even a small level of connectivity of the ceramic phase causes significant changes in the thermal expansion of isotropic metal/ceramic composites.
Experimental investigation of thermal fatigue behaviour of header tube to stub welded joint in power plants
Authors: Jinu G. R. , Sathiya P. , Ravichandran G. , Rathinam A.
Published: September 2010

Super heater tubes and outlet headers are subjected to thermal fatigue from alternating heating and cooling during start up and shut down, causing cracks and eventually failure. Super heater tubes are subjected to a temperature of 600 °C and steam at a temperature of 540 °C and a pressure of 160 bar. In this paper, a laboratory simulation for reproducing thermal fatigue phenomena was developed to determine the number of cycles before failure occurs in a header tube to stub welded joint. For this purpose a carbon steel tube (stub) welded to a carbon steel plate which resembles a header pipe to stub welded joint was subjected to thermal cycles from 800 °C (accelerated test) to room temperature. A tungsten inert gas arc was used as a heating source and a water bath was utilized for quenching. After 300 thermal cycles, the cross-section of the header was subjected to optical microscopy. Micro fissures were observed in the header tube. This study reveals that subsequent localized heating and cooling will cause thermal fatigue, which will initiate and propagate cracks in the tubes.
Giant Cell Tumor of the Distal Femur Associated with Complete Tumor Necrosis
Authors: Adams Sheila Conway , Potter Benjamin K. , Robinson Philip G. , Temple H. Thomas
Published: September 2010

Giant cell tumor is a benign tumor of bone with a predilection for juxta-articular locations. Although not malignant, giant cell tumor often exhibits unpredictable and locally aggressive behavior, and in rare cases can metastasize in the absence of histologic malignancy. Partial tumor necrosis has been infrequently reported within typical giant cell tumor. A 17-year-old girl presented with a right distal femur giant cell tumor associated with complete tumor necrosis on histopathologic analysis. The etiology, prevalence, and implications of complete necrosis in previously untreated giant cell tumor of bone remain unclear, as there are no previously published reports. Despite the complete necrosis evident in our patient, she nonetheless presented with pain. There were no radiographic signs of the necrotic tumor space remodeling with new bone. The patient was treated with standard extended intralesional curetting through a generous cortical window permitting visualization of the entire lesion, and systematic high speed burring and thermal electrocautery ablation of the periphery, followed by micro particulate allogenic bone grafting. At short-term follow-up, she had healed well with no evidence of tumor recurrence. This article presents the first case, to our knowledge, of complete spontaneous tumor necrosis in a previously untreated bone giant cell tumor. Increased understanding of spontaneous tumor necrosis associated with giant cell tumor may help guided future targeted medical and surgical treatment modalities.
Patient Satisfaction Following TKA: Bless Them All!
Authors: Beverland David
Published: September 2010

Survivorship following modern total knee arthroplasty (TKA) is good with revision rates generally lower than for total hip arthroplasty (THA). Our experience in Belfast supports that fact with original component survivorship of 99% for the low contact stress rotating platform TKA, which is better than our THA survivorship. It is important to discriminate between survivorship and patient satisfaction. In Belfast, as well as the more familiar outcome scores, we also use a very simple 4-point satisfaction questionnaire: “How would you best describe your satisfaction with your new joint” where 1=very happy, 2=happy, 3=OK but not perfect, and 4=I have never been happy. We applied this questionnaire to our 10-year THA and TKA patients. When we looked specifically at the numbers of patients who were either “very happy” or “never happy,” the results were very different. The very happy percentage for hips was much higher than for knees (54% vs 4%) and conversely, the number of never happy knees was much higher than for hips (7% vs 1%). These results are not unique to Belfast. As surgeons, we often think that the knee implant that we use is the best but at present, the implant is no longer the most critical factor. We need to increase the number of very happy patients and decrease the number of never happy ones. In my opinion the two key factors that we should focus on are patient expectation and surgeon education.
Uncemented Total Hip Arthroplasty with a Tapered Femoral Component: A 22- to 26-Year Follow-Up Study
Authors: McLaughlin Jeffrey R. , Lee Kyla R.
Published: September 2010

The goal of this study was to evaluate the outcome at a mean follow-up of 24.5 years (range, 22–26 years) of a consecutive series of 138 patients (145 hips) treated with total hip arthroplasty (THA) with the use of the Taperloc femoral component (Biomet, Warsaw, Indiana). This was an FDA-approved prospective study. All surgeries were performed by a single surgeon. Each of the 138 patients (145 hips) was followed annually until death, femoral component revision, or a minimum of 22 years. Complete clinical and radiographic follow-up was obtained on 95% of living patients at 5 years, and 100% at 10, 15, 20, and 24.5 years. Of the original series of 145 hips, only 1 femoral component (0.7%) had undergone revision for aseptic loosening, and 1 was loose by radiographic criteria (0.7%). Femoral osteolysis was identified in 8 hips (5.5%).

A subset of 63 THAs in 56 patients was followed for a mean of 24.5 years. In this group, no femoral component required revision for aseptic loosening, and 1 was loose by radiographic criteria. Femoral osteolysis was present in 4 hips. Survivorship analysis of the femoral component with revision for aseptic loosening as the endpoint was 99% (95% confidence interval, 0.97–100) at 26 years.

This stem demonstrates excellent fixation at a follow-up of 24.5 years with no apparent deterioration of the results with time.
Limit the Bleeding, Limit the Pain in Total Hip and Knee Arthroplasty
Authors: Friedman Richard J.
Published: September 2010

Patients undergoing total hip or knee arthroplasty often sustain significant decreases in hemoglobin and hematocrit, despite modern techniques and shorter operating times. Reasons for the blood loss include raw bony surfaces, vascular inflammatory tissue, and fragile vessels in elderly patients. Acute postoperative anemia has numerous deleterious effects on patients, including delayed rehabilitation, exposure to allogeneic blood transfusions, higher complication rates, and increased pain. The ability to limit the amount of postoperative bleeding may reduce the amount of postoperative pain that patients experience, ultimately resulting in greater patient satisfaction and smoother postoperative rehabilitation. This article focuses on intraoperative techniques available to limit bleeding, thereby minimizing pain and the need for postoperative transfusion.
Optimal Amount of Anisometropia for Pseudophakic Monovision
Authors: Hayashi Ken , Yoshida Motoaki , Manabe Shin-ichi , Hayashi Hideyuki
Published: September 2010

Purpose:

To determine the optimal target anisometropia for pseudophakic monovision.

Methods:

Thirty-five bilaterally pseudophakic patients who received monofocal intraocular lenses were included in the study. Binocular corrected distance visual acuity (CDVA) and binocular distance-corrected near visual acuity (DCNVA) and stereoacuity were measured after simulating 1.00, 1.50, and 2.00 diopters (D) of monovision by adding the appropriate spherical lens to the nondominant eye. We presumed that mean binocular DCNVA of 20/40, binocular CDVA of 20/25, and stereoacuity <100 seconds of arc (arc sec) were necessary for successful monovision.

Results:

With no anisometropia, mean binocular DCNVA was 20/97, binocular CDVA was 20/20, and mean stereoacuity was 71 arc sec. With 1.00 D of monovision, mean binocular DCNVA was only 20/60, although binocular CDVA and mean stereoacuity were sufficient. With 1.50 D of monovision, binocular DCNVA was 20/38, binocular CDVA at other distances exceeded 20/21, and stereoacuity was 100 arc sec, which was a 29-arc sec reduction. With 2.00 D of monovision, binocular DCNVA reached 20/31, but stereoacuity was 158 arc sec, which was an 87-arc sec reduction. The number of patients who met the criteria for successful monovision was significantly greater with 1.50 D of monovision than with 1.00 or 2.00 D of monovision (
P
=.0134).

Conclusions:

Pseudophakic monovision with anisometropia of 1.50 or 2.00 D provides useful binocular visual acuity from far to near. However, because stereopsis with 2.00 D of monovision is substantially impaired, approximately 1.50 D of anisometropia is thought to be optimal for successful monovision.
Retinal Layer Thickness Changes in Eyes with Preserved Visual Acuity and Diffuse Diabetic Macular Edema on Optical Coherence Tomography
Authors: Somfai Gábor Márk , Tátrai Erika , Ferencz Mária , Puliafito Carmen A. , DeBuc Delia Cabrera
Published: September 2010

Background and Objective:

Diabetic macular edema has several patterns on optical coherence tomography. This retrospective study aimed to assess which retinal layers show thickness changes in type 1 diffuse diabetic macular edema with preserved vision.

Patients and Methods:

Eleven eyes with diffuse diabetic macular edema on optical coherence tomography and eight control eyes with 20/20 best-corrected visual acuity were enrolled. Optical coherence tomography images were segmented using an algorithm of the authors’ design (OCTRIMA): regional thickness data in the central area, pericentral rings, and peripheral rings were obtained for the retinal cellular layers.

Results:

The retinal nerve fiber layer showed no changes, the ganglion cell and inner plexiform composite layer and the ganglion cell complex were thicker only in the pericentral regions, and all other layers were thicker in all regions in diffuse diabetic macular edema. Macular thickness was normal in the peripheral region.

Conclusion:

The results show that the outer retina in the foveal area is the most affected in diffuse diabetic macular edema.
Inside Scanlation
Authors: Leavitt Alex
Published: September 2010

Inside Scanlation [Web site review].
romanticization of abstinence: Fan response to sexual restraint in the Twilight series
Authors: Aubrey Jennifer Stevens , Behm-Morawitz Elizabeth , Click Melissa A.
Published: September 2010

Meyer's Twilight series has been criticized for its regressive gender representations. To understand its continuing appeal, we problematize the messages of abstinence and romance in the series, and contextualize fans' response with a discussion of postfeminist culture.
Exploring the body
Authors: Editor TWC
Published: September 2010

This unthemed issue centers on the preoccupation with the embodied fan. Essays discuss such topics as the concerns of the aging and the pregnant fan, the relationship of virginity and popular media texts among teen girl fans, and representations of disability in shows and fandoms.