bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic mechanical and rheological properties of nitrile rubber nanocomposites based on TiO2, Ca3(PO4)2 and layered silicate
Authors: Thomas PC , Jose E Tomlal , George Gejo , Thomas Sabu , Joseph Kuruvilla
Published: August 2013

The viscoelastic properties such as damping behaviour, storage and loss modulus, etc. of polymer composites depend on matrix filler interaction, crystallinity and the extent of crosslinking. It was observed that the storage modulus of the composites increased with the addition of filler due to the enhancement in stiffness of the material. The damping behaviour was found to decrease as a function of filler loading and this was attributed to the restricted movement of the polymer segments. The higher surface area to volume ratio factor of the layered silicate resulted in the better interaction between the polymer matrix and the filler, which resulted in the change in glass transition temperature. The flow properties were studied with special reference to filler loading of different fillers at a specified temperature. It was observed that complex viscosity of filled systems is higher than that of unfilled system. Among the fillers, layered silicate filled systems showed higher viscosity in comparison with calcium phosphate and titanium dioxide fillers.
Evaluation of some approximate estimates for the effective tetragonal elastic moduli of two-phase fiber-reinforced composites
Authors: Mogilevskaya Sofia G , Kushch Volodymyr I , Nikolskiy Dmitry
Published: August 2013

This paper examines three sets of approximate formulae for the overall tetragonal effective elastic properties of two-phase fiber-reinforced unidirectional composites with isotropic phases. The fibers are of circular cross-sections and periodically distributed in a matrix in a square pattern. The formulae by Kantor and Bergman, Luciano and Barbero, and estimates based on non-interacting Maxwell’s type approximations are rewritten in unified notations. The latter approximations coincide with the most of well-known estimates of the effective medium theories (composite cylinder model, generalized self-consistent model and the Mori–Tanaka method), as well as with one of the Hashin–Shtrikman variational bounds. The approximate estimates are compared with the exact periodic solutions to determine the range of their applicability. The simplest and most accurate formulae are identified and suggested as a set of approximate expressions for accurate estimates of the effective elastic properties of composite materials with a square symmetry.
Influences of thickness and stacking sequence on ballistic impact behaviors of GLARE 5 FML plates: Part II – Numerical studies
Authors: Yaghoubi A Seyed , Liaw B
Published: August 2013

This two-part article examines the effects of thickness and stacking sequence of GLARE 5 (2024-T3 aluminum alloy-unidirectional S2-glass/epoxy) fiber–metal laminated (FML) plates subjected to ballistic impact. Part I presented experimental observations of damage development in the specimens, C-scan damage contours, projectile velocity profiles and ballistic limit velocities ( V50). Part II concerns with finite element (FE) modeling of the FML plates. The 3D FE code, LS-DYNA, was used to model and validate the experimental results. Experimentally obtained incident projectile impact velocity versus the residual velocity ( Vi∼ Vr), damage patterns and bullet residual length were used to validate the FE model. Good agreement was achieved between experimental and numerical results. It was found that for a given specimen thickness/stacking-sequence, by increasing the projectile incident velocity up to its V50 value, the maximum contact force increased. By further increasing the projectile velocity above its V50, the maximum contact force was relatively invariant with respect to an increase in the projectile incident velocity.
Micromechanics-based progressive failure analysis prediction for WWFE-III composite coupon test cases
Authors: Chamis Christos C , Abdi Frank , Garg Mohit , Minnetyan Levon , Baid Harsh , Huang Dade , Housner Jerry , Talagani Farid
Published: August 2013

As a part of a world-wide study, a commercial code (General Optimization Analyzer), based on multi-scale (micro–macro) progressive failure analysis (PFA), is used to provide theoretical predictions for damage development for a set of challenging 13 test cases proposed in the Third World-Wide Failure Exercise (WWFE-III). Multiple failure criteria were utilized aimed at tackling issues related to a wide range of damage modes, being addressed by the WWFE-III. The critical damage events/indexes predictions tracked translaminar and interlaminar composite failures, namely matrix cracking/crack density, damage initiation/propagation, delamination initiation/growth, and their interaction with fiber failure. The composite laminates analysed were both with and without a central hole and the predictions were made using constituent fiber properties and matrix properties based on materials data or identification from ply stress–strain curve inputs. Loadings included uniaxial tension or compression, biaxial, bending, thermal, and loading–unloading.
An illustration of the optimization of combined cooling heating and power systems using genetic algorithm
Authors: Wang Jiangjiang , Yang Kun , Zhang Xutao , Shi Guohua , Fu Chao
Published: August 2013

The performances of combined cooling, heating and power (CCHP) system are greatly dependent on its design, operation strategy and thermal and electric demands. This paper illustrates how the use of a genetic algorithm can provide speedy optimization, by applying it to two styles of buildings operated in different operation strategies. The primary energy consumptions of CCHP system following electric demand management (EDM) and thermal demand management (TDM) are firstly analyzed respectively. Then, sixteen hypothetical buildings are constructed to represent various energy demands. Primary energy saving (PES), annual total cost saving (ATCS), and CO2 emission reduction (CO2ER), are weighted to evaluate the integrated performances of CCHP system in comparison to separation production system. Finally, the optimized CCHP system for sixteen scenarios using GA are compared.

Practical application: This paper provides an optimization design method for CCHP system. The performance analysis of CCHP systems running different operation modes for different buildings is believed by the authors to contribute to a significant guide for the fundamental design of CCHP systems. Although sensitivity to a number of other important design considerations such equipment performance, possible future changes in operating conditions, changes to the price or carbon intensity of grid-supplied energy etc are not addressed, the conclusions present a simple and effective direction and the proposed optimization algorithm and the evaluation method for CCHP system can be extended to other buildings.
Accuracy of Asymptotic Standard Errors of the Maximum and Weighted Likelihood Estimators of Proficiency Levels With Short Tests
Authors: Magis David
Published: August 2013

The maximum likelihood (ML) and the weighted likelihood (WL) estimators are commonly used to obtain proficiency level estimates with pre-calibrated item parameters. Both estimators have the same asymptotic standard error (ASE) that can be easily derived from the expected information function of the test. However, the accuracy of this asymptotic formula is unclear with short tests when only a few items are administered. The purpose of this paper is to compare the ASE of these estimators with their exact values, evaluated at the proficiency-level estimates. The exact standard error ( SE) is computed by generating the full exact sample distribution of the estimators, so its practical feasibility is limited to small tests (except under the Rasch model). A simulation study was conducted to compare the ASE and the exact SE of the ML and WL estimators, with the “true” SE (i.e., computed as the exact SE with the true proficiency levels). It is concluded that with small tests, the exact SEs are less biased and return smaller root mean square error values than the asymptotic SEs, while as expected, the two estimators return similar results with longer tests.
Phenotypic Characterization of Transgenic Japanese Medaka (Oryzias latipes) That Express a Red Fluorescent Protein in Hepatocytes
Authors: Van Wettere Arnaud J. , Law J. Mac , Hinton David E. , Kullman Seth W.
Published: August 2013

Transgenic organisms that express fluorescent proteins are used frequently for in vivo visualization of proteins and cells. The phenotype of a transgenic medaka ( Oryzias latipes) strain that expresses a red fluorescent protein (RFP) in hepatocytes was characterized using light and fluorescence microscopy, immunohistochemistry, and transmission electron microscopy (TEM). Expression of RFP was first detected by confocal fluorescence microscopy in the location of the liver bud of live medaka embryos at 60 hr postfertilization (developmental stage 27). Subsequently, RFP signal was observed exclusively in hepatocytes throughout life using fluorescence microscopy in live fish and immunohistochemistry in formalin-fixed, paraffin-embedded liver sections. As the fish aged, prominent intracytoplasmic eosinophilic inclusions immunoreactive for RFP were observed by light microscopy and were correlated with membrane-bound electron dense inclusions on TEM. These results define the onset and location of RFP expression in the Tg(zf.L-fabp:DsRed) medaka and characterize a histologic phenotype that results from RFP expression in hepatocytes.
The Microvascular Volume of the Achilles Tendon Is Increased in Patients With Tendinopathy at Rest and After a 1-Hour Treadmill Run
Authors: Pingel Jessica , Harrison Adrian , Simonsen Lene , Suetta Charlotte , Bülow Jens , Langberg Henning
Published: August 2013

Background:

Achilles tendinopathy (AT) is initiated asymptomatically and is therefore often discovered at a very late stage.

Purpose:

To elucidate whether the microvascular volume (MV) of the Achilles tendon is elevated in patients with AT compared with healthy controls during pre-exercise rest, after acute exercise, and 24 hours after exercise. Additionally, this study investigated the muscle activation pattern of the gastrocnemius muscle and the relative elasticity of the Achilles tendon during a 1-hour treadmill run in healthy patients and in patients with AT.

Study Design:

Controlled laboratory study.

Methods:

Real-time harmonic contrast-enhanced ultrasound (CEU) measurements of the MV of the Achilles tendon were taken in 18 volunteers (9 patients with AT, 9 healthy controls). The CEU analyses were conducted before exercise, immediately after a 1-hour treadmill run, and 24 hours after exercise. Surface electromyography (EMG) signals of the gastrocnemius were recorded continuously during the 1-hour treadmill run.

Results:

In both the controls and the patients with AT, the MV of the Achilles tendon was increased after exercise as compared with before exercise ( P < .005). Additionally, the MV signal was significantly larger in the patients with AT before, immediately after, and 24 hours after the running exercise compared with values in healthy controls ( P < .0001). The muscle activation pattern differed in patients with AT compared with controls in that controls had increased EMG amplitudes at the end of the 1-hour treadmill run in the medial and lateral gastrocnemius ( P < .0001). Moreover, patients with AT had approximately 15% less elastic Achilles tendons at the beginning of the 1-hour treadmill run, a condition that did not change because of exercise.

Conclusion:

Acute exercise increases the MV of the Achilles tendon in healthy patients and patients with AT in a similar manner. However, patients with AT have a significantly larger MV at all time points compared with healthy patients, supporting the hypothesis that microvascular changes may be involved in the pathogenesis of tendinopathy.

Clinical Relevance:

This study underlines that tendon flexibility is altered in patients with AT and that CEU is a promising tool to establish the early diagnosis of this condition.
The Ontogeny of Lexical Networks
Authors: Wojcik Erica H. , Saffran Jenny R.
Published: August 2013

Although the semantic relationships among words have long been acknowledged as a crucial component of adult lexical knowledge, the ontogeny of lexical networks remains largely unstudied. To determine whether learners encode relationships among novel words, we trained 2-year-olds on four novel words that referred to four novel objects, which were grouped into two visually similar pairs. Participants then listened to repetitions of word pairs (in the absence of visual referents) that referred to objects that were either similar or dissimilar to each other. Toddlers listened significantly longer to word pairs referring to similar objects, which suggests that their representations of the novel words included knowledge about the similarity of the referents. A second experiment confirmed that toddlers can learn all four distinct words from the training regime, which suggests that the results from Experiment 1 reflected the successful encoding of referents. Together, these results show that toddlers encode the similarities among referents from their earliest exposures to new words.
The effect of false positive breast screening examinations on subsequent attendance: retrospective cohort study
Authors: Maxwell Anthony J , Beattie Cathryn , Lavelle Janet , Lyburn Iain , Sinnatamby Ruchi , Garnett Shelagh , Herbert Annie
Published: August 2013

Objectives

To investigate the effect of false positive breast screening examination results on subsequent attendance in the UK National Health Service Breast Screening Programme.

Methods

253,017 previously screened women who were invited for rescreening were studied. Attendance rates of women who had received a normal result at the last (index) screen were compared with those of women who had received a false positive result. The effects of age, type of index screening examination (prevalent or incident) and tissue sampling at assessment were investigated.

Results

Women who had a false positive prevalent index screening examination were significantly more likely to reattend than those who had a normal prevalent index screening examination (87.7% vs. 86.0%). There was no significant difference in reattendance rates between women who had a false positive incident index screening examination and those with a normal incident index screening examination. However, women who underwent needle sampling or open biopsy following false positive incident index screening examinations were 12% and 60% less likely to reattend, respectively, than women whose index screening examinations were normal ( p < 0.001), although there was variation between centres. Increasing age significantly reduced the likelihood of reattendance. The overall reattendance of women who had been screened only once was six percentage points lower than that of women who had been screened more than once.

Conclusions

The findings suggest that most women who undergo the breast screening assessment process retain confidence in breast screening. Needle sampling and open biopsy should be used judiciously in the assessment of screen-detected abnormalities in view of the reduced reattendance that results from their use after incident screening examinations.
Development of personal identity among refugee adolescents
Authors: Ndengeyingoma Assumpta , Montigny Francine de , Miron Jean-Marie
Published: August 2013

This qualitative study examines what contributes to the development of personal identity among refugee adolescents of African origin who have immigrated to Québec. For this purpose, 12 adolescents participated in individual interviews and in self-recorded interviews. The research findings show that the development of young people’s personal identity is directly and indirectly influenced by personal characteristics, the environmental, and the interpersonal relationships. We identify both elements that facilitate the development of personal identity and obstacles to such development so as to provide better support for health education among refugee adolescents.
Towards a general theory of thrift
Authors: Podkalicka Aneta , Potts Jason
Published: August 2013

Thrift used to mean necessary scrimping and saving in order to get by. But more recently, with growing prosperity coupled with a heightened sense of global social and environmental fragility, the meaning of thrift has shifted in advanced economies connecting with various practices geared towards reconfigured modes of consumption and lifestyles – ethical, conscientious or collaborative. Many scholars and commentators have noted this shift and at least as many explanations have been proposed. This provides us with an opportunity to develop a more general theory of thrift by proposing that all thrift behaviours and practices can be understood over three basic dimensions that we identify as: (1) ‘causes of thrift’; (2) ‘meaning of thrift’; and (3) ‘thrift capital/capabilities’. We show how existing but disparate definitions and empirical studies of thrift can be organized with respect to this framework and how this enables us to elucidate the nature of the shift that is currently occurring.
Islamic Arab hospitality and multiculturalism
Authors: Sobh Rana , Belk Russell W. , Wilson Jonathan A. J.
Published: August 2013

This ethnographic study in Qatar and United Arab Emirates addresses a particular Islamic consumptionscape as well as a related commodified practice: that of Arab hospitality. This much vaunted Arab virtue is examined in three contexts: home hospitality, commercial hospitality, and hospitality toward foreign guest workers and visitors. We find that home hospitality is largely extended inward and involves sharing in with close same-sex friends and family in a tournament of status, while hospitality toward foreigners is largely either nonexistent or outsourced to other foreigners. These patterns are explained in terms of hyper-ritualization of that which is most in doubt, namely, multiculturalism and patriarchal authority. We argue that this same pattern of hyper-ritualization may apply in other ritual contexts like American Thanksgiving celebrations.
The Sufi ethics and the spirits of consumerism
Authors: Varul Matthias Zick
Published: August 2013

In this speculative comment I will suggest that, in analogy with Colin Campbell's argument regarding the Romantic Ethic and the spirit of modern consumerism, there is prima facie evidence that there is also an elective affinity between Sufi-infused Islamic religiosity and the emergent Muslim consumerisms, particularly in Turkey and among Turkish (and Kurdish) diasporas in Europe. The main relevant features of Sufi spirituality in this context are identified as continuous creation, creative imagination and longing.
Legislatures, Courts, and Statutory Control of the Bureaucracy across the U.S. States
Authors: McGrath Robert J.
Published: August 2013

How do state legislatures use statutory language to control policy implementation by state agencies? In this article, I consider—in a specific policy area and time period—the extent to which this decision is affected by legislative anticipation of the likely actions of state courts. Previous literature has argued that the legislative use of statutory language to control bureaucrats varies with the availability of nonstatutory methods of control, but it does not explicitly consider the potential role of courts. My expectations are derived from a simple formal model of executive–legislative relations and are supported when I test them using data on the number of words added to a state's Medicaid laws from 1995 to 1996. In particular, I find that state legislatures write longer, more constraining, statutes when the likelihood that state courts intervene on their behalf is neither very high nor very low.
Cytokine gene polymorphism among Indigenous Australians
Authors: Cox Amanda J , Moscovis Sophia M , Blackwell C Caroline , Scott Rodney J
Published: August 2013

The health profile of Indigenous Australians is characterised by high rates of classic ‘lifestyle’ diseases. Potential roles of inflammation in pathophysiology of these diseases requires investigation. It is not clear if genetic regulation of inflammation in Indigenous Australians is similar to other populations. This study characterised frequencies of single nucleotide polymorphisms (SNPs) for eight cytokine genes for 100 individuals from a remote Indigenous Australian community and assessed novel genetic variants in four cytokine genes. We used a commercially-available allelic discrimination assay for SNP genotyping; re-sequencing was undertaken by standard Sanger sequencing methodologies for 26 samples. Frequencies of cytokine gene SNPs differed significantly from the Caucasian population ( P < 0.001−0.044). Twenty-five novel variants were identified across four re-sequenced genes; frequencies ranged from <5% to 100%. Genotype frequencies observed in Indigenous Australians did not consistently resemble reported HapMap frequencies in Northern and Western European populations, Yoruba Nigerian or Han Chinese. Our findings indicate Indigenous Australians might have an inherited propensity for strong inflammatory responses. Preliminary evidence of novel genetic variants highlights the need to catalogue the extent of genetic variation in specific population groups. Improved understanding of differences in genetic variation between specific population groups could assist in assessment of risk for lifestyle diseases.
Cardiovascular disease in menopause: Does the obstetric history have any bearing?
Authors: Mahendru Amita A , Morris Edward
Published: August 2013

Cardiovascular disease remains a leading cause of morbidity and mortality in menopausal women in spite of the overall reduction in age-adjusted mortality from the disease in the last few years. It is now clear that mechanisms of cardiovascular disease in menopausal women are similar to men and rather than midlife acceleration of cardiovascular disease in women, the final impact of cardiovascular disease in later life may be a reflection of cardiovascular changes during reproductive years as a result of woman’s obstetric history. A decade after the Women’s Health Initiative trial, there is upcoming evidence to suggest that hormone replacement therapy in young recently menopausal women has a cardioprotective effect. Cardiovascular changes during normal pregnancy or pregnancy complications such as preeclampsia may affect a woman’s long-term cardiovascular health. Therefore, it is plausible that the cardioprotective benefit of hormone replacement therapy depends on occult pre-existing cardiovascular risks in women in relation to their previous obstetric history. In this review, we describe the cardiovascular changes during and after pregnancy in obstetric complications such as recurrent miscarriage, preeclampsia, intrauterine growth restriction, preterm labour and gestational diabetes; existing evidence regarding their association with cardiovascular disease later in life, and hypothesize possible mechanisms. Our aim is to improve the understanding and highlight the importance of including obstetric history in risk assessment in menopausal women and individualizing their risks before prescribing hormone replacement therapy. Future research in risk benefit assessment of hormone replacement therapy should also account for a woman’s background cardiovascular risk in the light of her obstetric history.
Epidemiology of Hip Injuries in the National Basketball Association
Authors: Jackson Timothy J. , Starkey Chad , McElhiney Danielle , Domb Benjamin G.
Published: August 2013

Background:

Professional athletes are subject to various injuries that are often dictated by the nature of their sport. Professional basketball players previously have been shown to sustain injuries throughout the musculoskeletal system, most commonly to the ankle and knee.

Purpose:

The purpose of this study was to report the epidemiology of injuries specific to the pelvis, hip, and thigh and their effect on games missed in professional basketball players.

Study Design:

Descriptive epidemiological.

Methods:

Records were recalled from the National Basketball Association epidemiological database for athletic-related pelvis, hip, or thigh injuries that occurred from the 1988-1989 through the 2011-2012 seasons. The primary information collected included anatomic location where the injury occurred, when in the course of the season injury occurred, specific pathology, date, activity at the time of injury, injury mechanism, number of practices and games missed, and whether surgery was required. The number of practices and games missed were summed to yield the number of days missed per episode.

Results:

There were 2852 cases (14.6% of all athletic-related injuries) involving 967 individual players. In 1746 (61.2%) cases, injuries occurred during game competition. Across the course of this study, clinical incidence of injury to the pelvis, hip, or thigh was 1.50 per 100 players. The mean (±standard deviation) number of days missed per case was 6.3 ± 10.2. The quadriceps group was the most commonly injured structure (contusions and strains) and had a significantly higher game-related injury rate than other structures (0.96 per 100 athletic exposures, 95% confidence interval [CI] = 0.87-1.04). Players had the greatest risk (relative risk = 1.38, 95% CI = 1.26-1.52) of sustaining a strain than any other type of injury, with a game-related injury rate of 1.79 (95% CI = 1.67-1.90). The hamstring muscle group was the most frequently strained. Strains were more likely to occur in the preseason.

Conclusion:

Pelvis, hip, and thigh injuries in professional basketball players are commonly extra-articular strains and contusions and represent a significant burden of injury. The actual amount of intra-articular hip disorders may be underestimated, as the awareness of these disorders has increased only in the past decade. With the awareness of the types of injuries that occur in this region, focused injury prevention strategies may be beneficial to players and teams at all levels of competition, not only professional athletes.
PKIS: computational identification of protein kinases for experimentally discovered protein phosphorylation sites
Authors: Zou Liang , Wang Mang , Shen Yi , Liao Jie , Li Ao , Wang Minghui
Published: August 2013

Background

Dynamic protein phosphorylation is an essential regulatory mechanism in various organisms. In this capacity, it is involved in a multitude of signal transduction pathways. Kinase-specific phosphorylation data lay the foundation for reconstruction of signal transduction networks. For this reason, precise annotation of phosphorylated proteins is the first step toward simulating cell signaling pathways. However, the vast majority of kinase-specific phosphorylation data remain undiscovered and existing experimental methods and computational phosphorylation site (P-site) prediction tools have various limitations with respect to addressing this problem.

Results

To address this issue, a novel protein kinase identification web server, PKIS, is here presented for the identification of the protein kinases responsible for experimentally verified P-sites at high specificity, which incorporates the composition of monomer spectrum (CMS) encoding strategy and support vector machines (SVMs). Compared to widely used P-site prediction tools including KinasePhos 2.0, Musite, and GPS2.1, PKIS largely outperformed these tools in identifying protein kinases associated with known P-sites. In addition, PKIS was used on all the P-sites in Phospho.ELM that currently lack kinase information. It successfully identified 14 potential SYK substrates with 36 known P-sites. Further literature search showed that 5 of them were indeed phosphorylated by SYK. Finally, an enrichment analysis was performed and 6 significant SYK-related signal pathways were identified.

Conclusions

In general, PKIS can identify protein kinases for experimental phosphorylation sites efficiently. It is a valuable bioinformatics tool suitable for the study of protein phosphorylation. The PKIS web server is freely available athttp://bioinformatics.ustc.edu.cn/pkis.
Changes in sub-cellular localisation of trophoblast and inner cell mass specific transcription factors during bovine preimplantation development
Authors: Madeja Zofia E , Sosnowski Jaroslaw , Hryniewicz Kamila , Warzych Ewelina , Pawlak Piotr , Rozwadowska Natalia , Plusa Berenika , Lechniak Dorota
Published: August 2013

Background

Preimplantation bovine development is emerging as an attractive experimental model, yet little is known about the mechanisms underlying trophoblast (TE)/inner cell mass (ICM) segregation in cattle. To gain an insight into these processes we have studied protein and mRNA distribution during the crucial stages of bovine development. Protein distribution of lineage specific markers OCT4, NANOG, CDX2 were analysed in 5-cell, 8–16 cell, morula and blastocyst stage embryos. ICM/TE mRNA levels were compared in hatched blastocysts and included: OCT4, NANOG, FN-1, KLF4, c-MYC, REX1, CDX2, KRT-18 and GATA6.

Results

At the mRNA level the observed distribution patterns agree with the mouse model. CDX2 and OCT4 proteins were first detected in 5-cell stage embryos. NANOG appeared at the morula stage and was located in the cytoplasm forming characteristic rings around the nuclei. Changes in sub-cellular localisation of OCT4, NANOG and CDX2 were noted from the 8–16 cell onwards. CDX2 initially co-localised with OCT4, but at the blastocyst stage a clear lineage segregation could be observed. Interestingly, we have observed in a small proportion of embryos (2%) that CDX2 immunolabelling overlapped with mitotic chromosomes.

Conclusions

Cell fate specification in cattle become evident earlier than presently anticipated – around the time of bovine embryonic genome activation. There is an intriguing possibility that for proper lineage determination certain transcription factors (such as CDX2) may need to occupy specific regions of chromatin prior to its activation in the interphase nucleus. Our observation suggests a possible role of CDX2 in the process of epigenetic regulation of embryonic cell fate.
Feasibility study demonstrating that enzymatic template generation and amplification can be employed as a novel method for molecular antimicrobial susceptibility testing
Authors: Sodowich Bruce I , Zweitzig Daniel R , Riccardello Nichol M , O’Hara S Mark
Published: August 2013

Background

Antimicrobial Susceptibility Testing (AST) is a methodology in which the sensitivity of a microorganism is determined via its inability to proliferate in the presence of an antimicrobial agent. Results are reported as minimum inhibitory concentrations (MICs). The present study demonstrates that measurement of DNA polymerase activity via Enzymatic Template Generation and Amplification (ETGA) can be used as a novel means of determining the MIC of a microbe to an antibiotic agent much sooner than the current standardized method.

Methods

Time course analysis of ETGA is presented from bacterial cultures containing antibiotic agents and compared to the end-point results of standard macrobroth method AST.

Results

MIC determinations from ETGA results at 4, 6, and 22 hours are compared to the MICs from the standard method and the results are shown to be in agreement. Additionally, reliable AST analysis using ETGA can be performed on bacteria harvested directly from spiked blood cultures.

Conclusions

AST analysis with ETGA is shown to be equivalent to AST analysis using gene-specific qPCR assays against the measured microbe. Future development of this novel method for performing AST in a clinical setting is discussed.
“Rescue” ablation of electrical storm in arrhythmogenic right ventricular cardiomyopathy in pregnancy
Authors: Stec Sebastian , Krynski Tomasz , Baran Jakub , Kulakowski Piotr
Published: August 2013

Background

Radiofrequency ablation (RFCA) became a treatment of choice in patients with recurrent ventricular tachycardia, ventricular fibrillation, and appropriate interventions of implanted cardioverter-defibrillator (ICD), however, electrical storm (ES) ablation in a pregnant woman has not yet been reported.

Case presentation

We describe a case of a successful rescue ablation of recurrent ES in a 26-year-old Caucasian woman during her first pregnancy (23rd week). The arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) was diagnosed 3 years earlier and several drugs as well as 2 ablations failed to control recurrences of ventricular tachycardia. RFCA was performed on the day of the third electric storm. The use of electroanatomic mapping allowed very low X-ray exposure, and after applications in the right ventricular outflow tract, arrhythmia disappeared. Three months after ablation, a healthy girl was delivered without any complications. During twelve-month follow-up there was no recurrence of ventricular tachycardia or ICD interventions.

Conclusions

This case documents the first successful RFCA during ES due to recurrent unstable ventricular arrhythmias in a patient with ARVD/C in pregnancy. Current guidelines recommend metoprolol, sotalol and intravenous amiodarone for prevention of recurrent ventricular tachycardia in pregnancy, however, RFCA should be considered as a therapeutic option in selected cases. The use of 3D navigating system and near zero X-ray approach is associated with minimal radiation exposure for mother and fetus as well as low risk of procedural complication.
Comparing human papillomavirus prevalences in women with normal cytology or invasive cervical cancer to rank genotypes according to their oncogenic potential: a meta-analysis of observational studies
Authors: Bernard Erik , Pons-Salort Margarita , Favre Michel , Heard Isabelle , Delarocque-Astagneau Elisabeth , Guillemot Didier , Thiébaut Anne CM
Published: August 2013

Background

Mucosal human papillomavirus (HPV) infection is a necessary cause of cervical cancer. Vaccine and non-vaccine genotype prevalences may change after vaccine introduction. Therefore, it appears essential to rank HPV genotypes according to their oncogenic potential for invasive cervical cancer, independently of their respective prevalences.

Methods

We performed meta-analyses of published observational studies and estimated pooled odds ratios with random-effects models for 32 HPV genotypes, using HPV-16 as the reference.

Results

Twenty-seven studies yielded 9,252 HPV-infected women: 2,902 diagnosed with invasive cervical cancer and 6,350 with normal cytology. Expressed as (odds ratio [95% confidence interval]), HPV-18 (0.63 [0.51, 0.78]) ranked closest to HPV-16, while other genotypes showed continuously decreasing relative oncogenic potentials: HPV-45 (0.35 [0.22, 0.55]), HPV-69 (0.28 [0.09, 0.92]), HPV-58 (0.24 [0.15, 0.38]), HPV-31 (0.22 [0.14, 0.35]), HPV-33 (0.22 [0.12, 0.38]), HPV-34 (0.21 [0.06, 0.80]), HPV-67 (0.21 [0.06, 0.67]), HPV-39 (0.17 [0.09, 0.30]), HPV-59 (0.17 [0.09, 0.31]), HPV-73 (0.16 [0.06, 0.41]), and HPV-52 (0.16 [0.11, 0.23]).

Conclusions

Our results support the markedly higher oncogenic potentials of HPV-16 and -18, followed by HPV-31, -33, -39, -45, -52, -58 and -59, and highlight the need for further investigation of HPV-34, -67, -69 and -73. Overall, these findings could have important implications for the prevention of cervical cancer.
Mindfulness training for stress management: a randomised controlled study of medical and psychology students
Authors: de Vibe Michael , Solhaug Ida , Tyssen Reidar , Friborg Oddgeir , Rosenvinge Jan H , Sørlie Tore , Bjørndal Arild
Published: August 2013

Background

Distress and burnout among medical and psychology professionals are commonly reported and have implications for the quality of patient care delivered. Already in the course of university studies, medicine and psychology students report mental distress and low life satisfaction. There is a need for interventions that promote better coping skills in students in order to prevent distress and future burnout. This study examines the effect of a seven-week Mindfulness-Based Stress Reduction (MBSR) programme on mental distress, study stress, burnout, subjective well-being, and mindfulness of medical and psychology students.

Methods

A total of 288 students (mean age = 23 years, 76% female) from the University of Oslo and the University of Tromsø were randomly allocated to an intervention or control group. The control group continued with their standard university courses and received no intervention. Participants were evaluated using self-reported measures both before and after the intervention. These were: the ‘General Health Questionnaire, Maslach Burnout Inventory Student version, Perceived Medical School Stress, Subjective Well-being, and Five Facet Mindfulness Questionnaire’ and additional indices of compliance.

Results

Following the intervention, a moderate effect on mental distress (Hedges’g 0.65, CI = .41, .88), and a small effect on both subjective well-being (Hedges’g 0.40, CI = .27, .63) and the mindfulness facet ‘non-reacting’ (Hedges’g 0.33, CI = .10, .56) were found in the intervention group compared with the control group. A higher level of programme attendance and reported mindfulness exercises predicted these changes. Significant effects were only found for female students who additionally reported reduced study stress and an increase in the mindfulness facet ‘non-judging’. Gender specific effects of participation in the MBSR programme have not previously been reported, and gender differences in the present study are discussed.

Conclusion

Female medical and psychology students experienced significant positive improvements in mental distress, study stress, subjective well-being and mindfulness after participating in the MBSR programme.

Trial registration

NCT00892138
Dislodgement of port-A catheters in pediatric oncology patients: 11 years of experience
Authors: Wang Su-Chen , Tsai Chia-Hui , Hou Chiu-Ping , Lee Shin-Yi , Ko Sheung-Fat , Hsiao Chih-Chen , Chen Yu-Chieh , Chuang Jiin-Haur , Sheen Jiunn-Ming
Published: August 2013

Background

Port-A catheters are frequently used in pediatric cancer patients. Their dislodgement is potentially seriously risky although the incidence is not high. We analyzed our 11 years of data to address this important problem.

Methods

From January 2001 to December 2011, 330 port-A catheters of different brands were implanted in pediatric cancer patients. In total, eight children suffered a dislodgement of their catheter. Their ages ranged from four to thirteen years, with a median age of ten. Five patients presented with catheter dysfunction, two presented with a cough and one was identified incidentally during surgery to remove his port.

Results

The downstream ends of the dislodged catheters were located in the right atrium (three patients), left pulmonary artery (three) and inferior vena cava (two). Six of the eight catheters were broken at the site of anastomosis to the port and the other two were broken halfway in between. All episodes of dislodgement happened after the chemotherapy regimen was completed. The dislodged catheters were successfully retrieved without complications by transcatheter retrieval using a gooseneck snare.

Conclusions

The dislodgment rate of port-A catheter in our series was 2.4%. Chest X-rays can rapidly detect the problem. Most of the catheters were broken at the site of anastomosis. Earlier explantation of port-A catheters after completing chemotherapy may be considered to avoid the dislodgement of catheters, but this needs to be weighed against the possibility of underlying disease recurrence. However, we should re-examine how long port-A catheters need to be retained after chemotherapy considering the improved cure rate of pediatric cancer.
Different effects of progesterone and estradiol on chimeric and wild type aldosterone synthase in vitro
Authors: Vecchiola Andrea , Lagos Carlos F , Fuentes Cristóbal A , Allende Fidel , Campino Carmen , Valdivia Carolina , Tapia-Castillo Alejandra , Ogishima Tadashi , Mukai Kuniaki , Owen Gareth , Solari Sandra , Carvajal Cristian A , Fardella Carlos E
Published: August 2013

Background

Familial hyperaldosteronism type I (FH-I) is caused by the unequal recombination between the 11beta-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes, resulting in the generation of a CYP11B1/B2 chimeric gene and abnormal adrenal aldosterone production. Affected patients usually show severe hypertension and an elevated frequency of stroke at a young age. Aldosterone levels rise during pregnancy, yet in pregnant women with FH-1, their hypertensive condition either remains unchanged or may even improve. The purpose of this study was to investigate in vitro whether female sex steroids modulate the activity of chimeric (ASCE) or wild type (ASWT) aldosterone synthase enzymes.

Methods

We designed an in vitro assay using HEK-293 cell line transiently transfected with vectors containing the full ASCE or ASWT cDNAs. Progesterone or estradiol effects on AS enzyme activities were evaluated in transfected cells incubated with deoxycorticosterone (DOC) alone or DOC plus increasing doses of these steroids.

Results

In our in vitro model, both enzymes showed similar apparent kinetic parameters (Km = 1.191 microM and Vmax = 27.08 microM/24 h for ASCE and Km = 1.163 microM and Vmax = 36.98 microM/24 h for ASWT; p = ns, Mann–Whitney test). Progesterone inhibited aldosterone production by ASCE- and ASWT-transfected cells, while estradiol demonstrated no effect. Progesterone acted as a competitive inhibitor for both enzymes. Molecular modelling studies and binding affinity estimations indicate that progesterone might bind to the substrate site in both ASCE and ASWT, supporting the idea that this steroid could regulate these enzymatic activities and contribute to the decay of aldosterone synthase activity in chimeric gene-positive patients.

Conclusions

Our results show an inhibitory action of progesterone in the aldosterone synthesis by chimeric or wild type aldosterone synthase enzymes. This is a novel regulatory mechanism of progesterone action, which could be involved in protecting pregnant women with FH-1 against hypertension. In vitro, both enzymes showed comparable kinetic parameters, but ASWT was more strongly inhibited than ASCE. This study implicates a new role for progesterone in the regulation of aldosterone levels that could contribute, along with other factors, to the maintenance of an adequate aldosterone-progesterone balance in pregnancy.
Quantitative analysis of the time-course of viral DNA forms during the HIV-1 life cycle
Authors: Munir Soundasse , Thierry Sylvain , Subra Frédéric , Deprez Eric , Delelis Olivier
Published: August 2013

Background

HIV-1 DNA is found both integrated in the host chromosome and unintegrated in various forms: linear (DNAL) or circular (1-LTRc, 2-LTRc or products of auto-integration). Here, based on pre-established strategies, we extended and characterized in terms of sensitivity two methodologies for quantifying 1-LTRc and DNAL, respectively, the latter being able to discriminate between unprocessed or 3′-processed DNA.

Results

Quantifying different types of viral DNA genome individually provides new information about the dynamics of all viral DNA forms and their interplay. For DNAL, we found that the 3′-processing reaction was efficient during the early stage of the replication cycle. Moreover, strand-transfer inhibitors (Dolutegravir, Elvitegravir, Raltegravir) affected 3′-processing differently. The comparisons of 2-LTRc accumulation mediated by either strand-transfer inhibitors or catalytic mutation of integrase indicate that 3′-processing efficiency did not influence the total 2-LTRc accumulation although the nature of the LTR-LTR junction was qualitatively affected. Finally, a significant proportion of 1-LTRc was generated concomitantly with reverse transcription, although most of the 1-LTRc were produced in the nucleus.

Conclusions

We describe the fate of viral DNA forms during HIV-1 infection. Our study reveals the interplay between various forms of the viral DNA genome, the distribution of which can be affected by mutations and by inhibitors of HIV-1 viral proteins. In the latter case, the quantification of 3′-processed DNA in infected cells can be informative about the mechanisms of future integrase inhibitors directly in the cell context.
Plants used for making recreational tea in Europe: a review based on specific research sites
Authors: Sõukand Renata , Quave Cassandra L , Pieroni Andrea , Pardo-de-Santayana Manuel , Tardío Javier , Kalle Raivo , Łuczaj Łukasz , Svanberg Ingvar , Kolosova Valeria , Aceituno-Mata Laura , Menendez-Baceta Gorka , Kołodziejska-Degórska Iwona , Pirożnikow Ewa , Petkevičius Rolandas , Hajdari Avni , Mustafa Behxhet
Published: August 2013

This paper is a review of local plants used in water infusions as aromatic and refreshing hot beverages (recreational tea) consumed in food-related settings in Europe, and not for specific medicinal purposes. The reviewed 29 areas are located across Europe, covering the post-Soviet countries, eastern and Mediterranean Europe. Altogether, 142 taxa belonging to 99 genera and 40 families were reported. The most important families for making herbal tea in all research areas were Lamiaceae and Asteraceae, while Rosaceae was popular only in eastern and central Europe. With regards to botanical genera, the dominant taxa includedMentha,Tilia, Thymus, Origanum,RubusandMatricaria. The clear favorite wasOriganum vulgareL., mentioned in 61% of the regions. Regionally, other important taxa includedRubus idaeusL. in eastern Europe,Chamaemelum nobile(L.) All. in southern Europe andRosa caninaL. in central Europe. Future research on the pharmacological, nutritional and chemical properties of the plants most frequently used in the tea-making process is essential to ensure their safety and appropriateness for daily consumption. Moreover, regional studies dedicated to the study of local plants used for making recreational tea are important to improve our understanding of their selection criteria, cultural importance and perceived properties in Europe and abroad.
Genetics of amyotrophic lateral sclerosis: an update
Authors: Chen Sheng , Sayana Pavani , Zhang Xiaojie , Le Weidong
Published: August 2013

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder involving both upper motor neurons (UMN) and lower motor neurons (LMN). Enormous research has been done in the past few decades in unveiling the genetics of ALS, successfully identifying at least fifteen candidate genes associated with familial and sporadic ALS. Numerous studies attempting to define the pathogenesis of ALS have identified several plausible determinants and molecular pathways leading to motor neuron degeneration, which include oxidative stress, glutamate excitotoxicity, apoptosis, abnormal neurofilament function, protein misfolding and subsequent aggregation, impairment of RNA processing, defects in axonal transport, changes in endosomal trafficking, increased inflammation, and mitochondrial dysfunction. This review is to update the recent discoveries in genetics of ALS, which may provide insight information to help us better understanding of the disease neuropathogenesis.