bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic review and meta‐analysis of published trials comparing the effectiveness of transanal endoscopic microsurgery and radical resection in the management of early rectal cancer
Authors: Sajid M. S. , Farag S. , Leung P. , Sains P. , Miles W. F. A. , Baig M. K.
Published: October 2013

Aim

A systematic analysis was conducted of trials comparing the effectiveness of transanal endoscopic microsurgery (TEMS) with radical resection (RR) for T1 and T2 rectal cancer.

Method

An electronic search was carried out of trials reporting the effectiveness of TEMS and RR in the treatment of T1 and T2 rectal cancers.

Results

Ten trials including 942 patients were retrieved. There was a trend toward a higher risk of local recurrence (odds ratio 2.78; 95% confidence interval 1.42, 5.44; z = 2.97; P < 0.003) and overall recurrence (P < 0.01) following TEMS compared with RR. The risk of distant recurrence, overall survival (odds ratio 0.90; 95% confidence interval 0.49, 1.66; z = 0.33; P = 0.74) and mortality was similar. TEMS was associated with a shorter operation time and hospital stay and a reduced risk of postoperative complications (P < 0.0001). The included studies, however, were significantly diverse in stage and grade of rectal cancer and the use of neoadjuvant chemoradiotherapy.

Conclusion

Transanal endoscopic microsurgery appears to have clinically measurable advantages in patients with early rectal cancer. The studies included in this review do not allow firm conclusions as to whether TEMS is superior to RR in the management of early rectal cancer. Larger, better designed and executed prospective studies are needed to answer this question.
One‐Minute Walk and modified Timed Up and Go tests in children with cerebral palsy: performance and minimum clinically important differences
Authors: Hassani Sahar , Krzak Joseph J , Johnson Barbara , Flanagan Ann , Gorton George , Bagley Anita , Õunpuu Sylvia , Romness Mark , Tylkowski Chester , Oeffinger Donna
Published: October 2013

Aim

This prospective multicenter study assessed performance and changes over time, with and without surgical intervention, in the modified Timed Up and Go (mTUG) and One‐Minute Walk tests (1MWT) in children with bilateral cerebral palsy (CP). Minimum clinically important differences (MCIDs) were established for these tools.

Method

Two hundred and nineteen participants with bilateral spastic CP (Gross Motor Function Classification System [GMFCS] levels I–III) were evaluated at baseline and 12 months follow‐up. The non‐surgical group (n=168; 54 females, 114 males; mean age 12y 11mo, [SD 2y 7mo], range 8y 1mo–19y) had no surgical interventions during the study. The surgical group (n=51; 19 females, 32 males; mean age 12y 10mo [SD 2y 8mo] range 8y 2mo–17y 5mo) underwent soft‐tissue and/or bony procedures within 12 months from baseline. The mTUG and 1MWT were collected and MCIDs were established from the change scores of the non‐surgical group.

Results

Dependent walkers (GMFCS level III) required more time to complete the mTUG (p≤0.01) than independent walkers (GMFCS levels I and II). For the 1MWT, distance walked decreased with increasing impairment (p≤0.01). 1MWT and mTUG change scores were not significantly different at any GMFCS level for either the surgical or non‐surgical groups (p≤0.01).

Interpretation

Children with varying levels of function (GMFCS level) perform differently on the 1MWT and mTUG. The data and MCID values can assist clinicians in interpreting changes over time and in assessing interventions.
Age‐dependent decline of β‐cell function in type 1 diabetes after diagnosis: a multi‐centre longitudinal study
Authors: Barker A. , Lauria A. , Schloot N. , Hosszufalusi N. , Ludvigsson J. , Mathieu C. , Mauricio D. , Nordwall M. , Van der Schueren B. , Mandrup‐Poulsen T. , Scherbaum W. A. , Weets I. , Gorus F. K. , Wareham N. , Leslie R. D. , Pozzilli P.
Published: October 2013

Aims

C‐peptide secretion is currently the only available clinical biomarker to measure residual β‐cell function in type 1 diabetes. However, the natural history of C‐peptide decline after diagnosis can vary considerably dependent upon several variables. We investigated the shape of C‐peptide decline over time from type 1 diabetes onset in relation to age at diagnosis, haemoglobin A1c (HbA1c) levels and insulin dose.

Methods

We analysed data from 3929 type 1 diabetes patients recruited from seven European centres representing all age groups at disease onset (childhood, adolescence and adulthood). The influence of the age at onset on β‐cell function was investigated in a longitudinal analysis at diagnosis and up to 5‐years follow‐up.

Results

Fasting C‐peptide (FCP) data at diagnosis were available in 3668 patients stratified according to age at diagnosis in four groups (<5 years, n = 344; >5 years < 10 years, n = 668; >10 years < 18 years, n = 991; >18 years, n = 1655). FCP levels were positively correlated with age (p < 0.001); the subsequent decline in FCP over time was log‐linear with a greater decline rate in younger age groups (p < 0.0001).

Conclusions

This study reveals a positive correlation between age at diagnosis of type 1 diabetes and FCP with a more rapid decline of β‐cell function in the very young patients. These data can inform the design of clinical trials using C‐peptide values as an end‐point for the effect of a given treatment.
Calmodulin‐like skin protein level increases in the differentiated epidermal layers in atopic dermatitis
Authors: Donovan Mark , Ambach Andreas , Thomas‐Collignon Agnés , Prado Cecilia , Bernard Dominique , Jammayrac Odette , Gollnick Harald , de Lacharriere Olivier
Published: October 2013

In atopic dermatitis (AD), the skin barrier is disturbed, and the expression of calcium‐dependent S100 proteins and the calcium gradient is also altered in the epidermis. The calmodulin‐like skin protein (CLSP), which is expressed in the differentiated epidermis, is believed to modulate the function of calcium‐dependent proteins involved in barrier formation and is significantly increased in the epidermis of psoriatic patients. We, therefore, investigated the CLSP level in skin biopsies taken from patients with acute exacerbated and non‐exacerbated AD as well as from healthy control subjects. Immunohistochemical, Western blot and ELISA analyses showed significant increases (P < 0.03) in CLSP level in the epidermis from patients with acute exacerbated AD as compared to that from patients with non‐exacerbated AD and from control subjects. Such increased expression of CLSP may help re‐establish a functional epidermal barrier in acute AD.
Effluent syntaxin3 from dying cells affords protection against apoptosis in epidermal keratinocytes
Authors: Miyazaki Takafumi , Kadono Nanako , Konishi Yoshihiro , Hagiwara Natsumi , Maekubo Kenji , Hirai Yohei
Published: October 2013

Ultra‐violet B (UVB)‐induced oxidative stress crucially perturbs the epidermal homeostasis, and the skin is endowed with protective mechanisms to take action against such damage. Here, we show the possible involvement of t‐SNARE protein syntaxin3, a membrane fusion mediator of cytoplasmic vesicles, and which is released from dying keratinocytes, to play a role in this response. UVB irradiation, which generates reactive oxidative stress in cells, was shown to lead to the keratinocyte cell death accompanied by a release of cytoplasmic syntaxin3. We found that such extracellularly sourced syntaxin3 completely blocked the processing of a crucial effector for apoptotic cell death, caspase‐3, and thus facilitated the survival of keratinocytes damaged by oxidative stress. These results demonstrate the latent prosurvival function of syntaxin3 and underline the importance of intracellular molecular elements for the maintenance of homeostasis in epidermal keratinocytes.
The relative importance of viral lysis and nanoflagellate grazing for prokaryote mortality in temperate lakes
Authors: Ram Angia Sriram Pradeep , Palesse Stephanie , Colombet Jonathan , Thouvenot Antoine , Sime‐Ngando Telesphore
Published: October 2013

We explored the factors that potentially affect viral abundance, viral life strategies (lytic versus lysogenic cycle) and the relative importance of viral lysis and heterotrophic nanoflagellate grazing for prokaryote mortality in the euphotic zone of 19 freshwater lakes in a single geographical region (the French Massif Central).

Flow cytometry indicated that viral abundance ranged from 0.5 to 26.3 × 107 viruses mL−1, exceeding prokaryote abundance by c. 16‐fold on average. Multiple regressions revealed that prokaryotic abundance was the best predictor of viral abundance (r2 = 0.74), suggesting that the prokaryotes were the major hosts for viral proliferation in these lakes.

Viral life strategies varied with month of sampling (June, July, August 2010). Lytic infection was the prominent mode of viral infection in June and August, whereas lysogenic infection was more evident in July in the majority of sampled lakes. This temporal shift in viral strategy was controlled by the availability of phosphate and chlorophyll concentration via host cell growth, with high concentrations favouring lytic infection and low concentrations favouring lysogenic infection. Such antagonistic interactions between viral life strategies support the hypothesis that lysogeny may represent a survival strategy for viruses in harsh nutrient/host conditions.

The dominance of viruses over flagellates, or vice versa, as prokaryotic mortality factors differed between the lakes. By taking into account both forms of mortality, our study indicates that viruses and flagellates are likely to act additively in their effects on prokaryotes by regulating the proportion of the most active members of the prokaryotic community. Such a combined effect of viruses and flagellates may strongly influence the planktonic food web and whole‐ecosystem functioning.
Optimisation of Novozym‐435‐catalysed esterification of fatty acid mixture for the preparation of medium‐ and long‐chain triglycerides (MLCT) in solvent‐free medium
Authors: Yang Kaizhou , Bi Yanlan , Sun Shangde , Yang Guolong , Ma Sumin , Liu Wei
Published: October 2013

Novozym‐435‐catalysed esterification of caprylic acid, capric acid and oleic acid with glycerol for the synthesis of medium‐ and long‐chain triglycerides (MLCT) in vacuum and solvent‐free system was investigated in this study. Response surface methodology with a three‐level, four‐factorial design was applied to optimise the enzymatic esterification for the synthesis of MLCT. The optimum conditions were as follows: reaction temperature 90 °C, 4.80 wt% enzyme load (relative to the weight of total substrates) and substrate molar ratio (fatty acids/glycerol) of 3:1 and 12.37 h. Under above‐mentioned conditions, Triglycerides (TG) yield, MLCT and the residual free fatty acids (FFA) content in the product were 93.54%, 72.19% and 4.21%, respectively. The content of caprylic acid, capric acid and long‐chain fatty acids of TG was 24%, 10% and 66%, respectively. Novozym 435 in the study showed no selectivity for the different fatty acids and also could be used 14 times without obvious loss of enzyme activity.
Interleukin‐17 increases the expression of Toll‐like receptor 3 via the STAT3 pathway in rheumatoid arthritis fibroblast‐like synoviocytes
Authors: Lee Seon‐Yeong , Yoon Bo‐Young , Kim Ju‐In , Heo Yang‐Mi , Woo Yun‐Ju , Park Sung‐Hwan , Kim Ho Youn , Kim Sung‐Il , Cho Mi‐La
Published: October 2013

We examined the effect of interleukin‐17 (IL‐17) on the expression of Toll‐like receptors (TLRs) in fibroblast‐like synoviocytes (FLS) from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). We investigated the region downstream of IL‐17 for TLR expression. We also investigated the downstream signals responsible for the effect of IL‐17 in TLR expression. Levels of IL‐17 protein in the serum and synovial fluid of RA and OA patients were measured by ELISA. The IL‐17 mRNA expression in peripheral blood mononuclear cells and synovial fluid mononuclear cells was measured by RT‐PCR. RA and OA FLS were incubated with IL‐17 and/or IL‐23 for 24 hr. To block the signal transducer and activator of transcription 3 (STAT3) pathway, FLS were treated with S3I‐201 before incubation with IL‐17 and IL‐23. Synovial tissue samples from RA and OA patients were stained with antibodies to IL‐17, TLR2, TLR3, TLR4, STAT3 and phospho‐STAT3. Levels of IL‐17 protein were higher in the serum and synovial fluid from RA patients compared with those from OA patients. The IL‐17 mRNA expression in synovial fluid monocytes was also higher in RA than in OA patients. Immunohistochemical staining showed greater expression of IL‐17, TLR2, TLR3 and TLR4 in synovial samples from RA compared with OA patients. Interleukin‐17 increased the expression of TLR2, TLR3 and TLR4 in RA FLS; IL‐23 augmented the IL‐17‐induced expression of TLR2, TLR3 and TLR4 in RA FLS. Blocking STAT3 with S3I‐201 reduced IL‐17‐induced TLR3 expression in RA FLS. Our results suggest that IL‐17 is a major cytokine in pathogenesis on RA. The IL‐17 influences the innate immune system by increasing the synovial expression of TLR2, TLR3 and TLR4. We may control TLR3 expression via the STAT3 pathway in RA FLS.
Mental health and learning disability nursing students' perceptions of the usefulness of the objective structured clinical examination to assess their competence in medicine administration
Authors: Hemingway Steve , Stephenson John , Roberts Bronwyn , McCann Terence
Published: October 2013

The aim of this study was to evaluate mental health and learning disability nursing students' perceptions of the usefulness of the objective structured clinical examination (OSCE) in assessing their administration of medicine competence. Learning disability (n = 24) and mental health (n = 46) students from a single cohort were invited to evaluate their experience of the OSCE. A 10‐item survey questionnaire was used, comprising open‐ and closed‐response questions. Twelve (50%) learning disability and 32 (69.6%) mental health nursing students participated. The OSCE was rated highly compared to other theoretical assessments; it was also reported as clinically real and as a motivational learning strategy. However, it did not rate as well as clinical practice. Content analysis of written responses identified four themes: (i) benefits of the OSCE; (ii) suggestions to improve the OSCE; (iii) concern about the lack of clinical reality of the OSCE; and (iv) OSCE‐induced stress. The themes, although repeating some of the positive statistical findings, showed that participants were critical of the university setting as a place to conduct clinical assessment, highlighted OSCE‐related stress, and questioned the validity of the OSCE as a real‐world assessment. The OSCE has an important role in the development of student nurses' administration of medicine skills. However, it might hinder their performance as a result of the stress of being assessed in a simulated environment.
Is glycosylated haemoglobin associated with psychosocial stress in non‐diabetic 6‐year‐olds?
Authors: Price Anna MH , Maayan Talia , Wake Melissa A , Hiscock Harriet
Published: October 2013

Aim

Glycosylated haemoglobin (HbA1c), a marker of diabetic glycemic control, is associated with chronic psychosocial stress in non‐diabetic adults. This study aimed to determine whether HbA1c also acts as a biomarker of psychosocial stress in healthy 6‐year‐olds.

Methods

Design and participants: Eligible participants were 326 children recruited from 6 socio‐economically diverse areas in Melbourne, Australia, who took part in an earlier randomised trial for sleep problems at age 7 months. At 6 years, they participated in a follow‐up assessment. Outcome: HbA1c collected by finger‐prick. Exposures (collected simultaneously): proxy measures of child stress including: (i) child mental health; (ii) maternal mental health (depression, anxiety, stress), negative life events in the preceding year, life stresses and coping; and (iii) family socioeconomic status and financial stress. Analyses: linear regressions, adjusted for original randomisation status and clustering.

Results

Sixty percent (134/225) of children retained at 6 years provided HbA1c data, which ranged from 3.9%–5.8% (SD 0.3%). No child or family variable was associated with HbA1c. Of the maternal variables, only anxiety predicted HbA1c (adjusted difference per point increase: −0.01, 95% CI: −0.003 to 0.02, P = 0.01); this association was in the opposite direction to that hypothesised and clinically insignificant.

Conclusion

HbA1c was not associated with psychosocial stress in healthy 6‐year‐olds. This suggests that any link between HbA1c and psychosocial stress emerges after this age, and that HbA1c is unlikely to be a reliable biomarker for stress in early childhood or over the transition to school.
Insomnia as a risk factor for ill health: results from the large population‐based prospective HUNT Study in Norway
Authors: Sivertsen Børge , Lallukka Tea , Salo Paula , Pallesen Ståle , Hysing Mari , Krokstad Steinar , Øverland Simon
Published: October 2013

Insomnia co‐occurs with many health problems, but less is known about the prospective associations. The aim of the current study was to investigate if insomnia predicts cumulative incidence of mental and physical conditions. Prospective population‐based data from the two last Nord‐Trøndelag Health Studies (HUNT2 in 1995–97 and HUNT3 in 2006–08), comprising 24 715 people in the working population, were used to study insomnia as a risk factor for incidence of physical and mental conditions. Insomnia was defined according to the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV). Insomnia at HUNT2 was a significant risk factor for incidence of a range of both mental and physical conditions at HUNT3 11 years later. Most effects were only slightly attenuated when adjusting for confounding factors, and insomnia remained a significant risk factor for the following conditions in the adjusted analyses: depression [odds ratio (OR): 2.38, 95% confidence interval (CI): 1.91–2.98], anxiety (OR: 2.08, 95% CI: 1.63–2.64), fibromyalgia (OR: 2.05, 95% CI: 1.51–2.79), rheumatoid arthritis (OR: 1.87, 95% CI: 1.29–2.52), whiplash (OR: 1.71, 95% CI: 1.21–2.41), arthrosis (OR: 1.68, 95% CI: 1.43–1.98), osteoporosis (OR: 1.52, 95% CI: 1.14–2.01, headache (OR: 1.50, 95% CI: 1.16–1.95, asthma (OR: 1.47, 95% CI: 1.16–1.86 and myocardial infarction (OR: 1.46, 95% CI: 1.06–2.00). Insomnia was also associated significantly with incidence of angina, hypertension, obesity and stroke in the crude analyses, but not after adjusting for confounders. We conclude that insomnia predicts cumulative incidence of several physical and mental conditions. These results may have important clinical implications, and whether or not treatment of insomnia would have a preventive value for both physical and mental conditions should be studied further.
The more the better – polyandry and genetic similarity are positively linked to reproductive success in a natural population of terrestrial salamanders (Salamandra salamandra)
Authors: Caspers Barbara A. , Krause E. Tobias , Hendrix Ralf , Kopp Michael , Rupp Oliver , Rosentreter Katrin , Steinfartz Sebastian
Published: October 2013

Although classically thought to be rare, female polyandry is widespread and may entail significant fitness benefits. If females store sperm over extended periods of time, the consequences of polyandry will depend on the pattern of sperm storage, and some of the potential benefits of polyandry can only be realized if sperm from different males is mixed. Our study aimed to determine patterns and consequences of polyandry in an amphibian species, the fire salamander, under fully natural conditions. Fire salamanders are ideal study objects, because mating, fertilization and larval deposition are temporally decoupled, females store sperm for several months, and larvae are deposited in the order of fertilization. Based on 18 microsatellite loci, we conducted paternity analysis of 24 female‐offspring arrays with, in total, over 600 larvae fertilized under complete natural conditions. More than one‐third of females were polyandrous and up to four males were found as sires. Our data clearly show that sperm from multiple males is mixed in the female's spermatheca. Nevertheless, paternity is biased, and the most successful male sires on average 70% of the larvae, suggesting a ‘topping off’ mechanism with first‐male precedence. Female reproductive success increased with the number of sires, most probably because multiple mating ensured high fertilization success. In contrast, offspring number was unaffected by female condition and genetic characteristics, but surprisingly, it increased with the degree of genetic relatedness between females and their sires. Sires of polyandrous females tended to be genetically similar to each other, indicating a role for active female choice.
The Dynamic Changes of Capillary Permeability and Upregulation of VEGF in Rats Following Radiation‐Induced Brain Injury
Authors: Jin Xuelong , Liang Bin , Chen Zequn , Liu Xingju , Zhang Zhiwen
Published: October 2013

Objective

To explore the dynamic changes of capillary permeability and the expression of VEGF in cerebral cortex after RIBI.

Methods

Male SD rats were randomly divided into the RIBI group and control group, and the RIBI group was randomly subdivided into five groups for analysis on day 1, 3, 7, 14, and 28, respectively. We established an RIBI model, and then evaluated BBB permeability by EB. We also measured the expression of VEGF with IHC stain and western blot.

Results

EB extravasation in injured cortex of RIBI group was increased at five time points compared with the control group. The western blot results and IHC revealed that the levels of VEGF expression in the RIBI groups was significantly increased at day 1 compared with the control group, then rose to a maximum at day 7, and subsequently the levels of expression recovered from day 14 to 28.

Conclusions

The increases in both BBB permeability and VEGF expression in the brain cortex of RIBI groups at same time period confirmed the possibility of brain injury following irradiation of 6 Gy.
The widespread crucifer species Cardamine flexuosa is an allotetraploid with a conserved subgenomic structure
Authors: Mandáková Terezie , Marhold Karol , Lysak Martin A.
Published: October 2013

The origin of Cardamine flexuosa (Wavy Bittercress) has been a conundrum for more than six decades. Here we identify its parental species, analyse its genome structure in comparison to parental genomes and describe intergenomic structural variations in C. flexuosa.

Genomic in situ hybridization (GISH) and comparative chromosome painting (CCP) uncovered the parental genomes and the chromosome composition of C. flexuosa and its presumed diploid progenitors.

Cardamine flexuosa is an allotetraploid (2n = 4x = 32), originating from two diploid species, Cardamine amara and Cardamine hirsuta (2n = 2x = 16). The two parental species display almost perfectly conserved chromosomal collinearity for seven out of the eight chromosomes. A 13 Mb pericentric inversion distinguishes chromosome CA1 from CH1.

A comparative cytomolecular map was established for C. flexuosa by CCP/GISH. Whereas conserved chromosome collinearity between the C. amara and C. hirsuta subgenomes might have promoted intergenomic rearrangements through homeologous recombination, only one reciprocal translocation between two homeologues has occurred since the origin of C. flexuosa. The genome of C. flexuosa demonstrates that allopolyploids can maintain remarkably stable subgenomes over 104–105 yr throughout a wide distribution range. By contrast, the rRNA genes underwent genome‐specific elimination towards a diploid‐like number of loci.
HIV infection and depression
Authors: Arseniou Stylianos , Arvaniti Aikaterini , Samakouri Maria
Published: October 2013

Major depression is highly prevalent among HIV‐positive patients (HIVpp). The prevalence of depression ranges between 18% and 81%, depending on the population studied and the methodology of the study. The etiology of depression in HIVpp is likely determined by: (i) biological factors (alterations in the white matter structure, hypothalamic–pituitary–thyroid dysfunction, Tat‐protein‐induced depressive behavior); (ii) psychosocial factors (HIV stigma, occupational disability, body image changes, isolation and debilitation); (iii) history or comorbidity of psychiatric illness; and (iv) the perinatal period in HIVpp women. Symptomatology of depression differs between HIVpp and HIV‐negative patients (HIVnp). Depression may also alter the function of lymphocytes in HIVpp and decrease natural killer cell activity, contributing to the increased mortality in these patients. Selective serotonin re‐uptake inhibitors are considered the first‐line treatment. Treatment of depression can improve quality of life and lead to a better prognosis of HIV infection.
Transferring Gracilaria irregularis (Gracilariaceae, Rhodophyta) from Thailand to Gracilariopsis based on morphological and molecular analyses
Authors: Muangmai Narongrit , Yamagishi Yukimasa , Zuccarello Giuseppe C. , Chirapart Anong , Lewmanomont Khanjanapaj
Published: October 2013

Gracilaria irregularis, endemic to Thailand, was originally described from Ao Len, Trat peninsula, Thailand, and was characterized by a short, succulent thallus with irregular branching, verrucosa‐type spermatangia (a taxonomic criterion for Gracilaria) and the absence of nutritive filaments (a taxonomic criterion for Gracilariopsis). Due to the combination of characters diagnostic of both the genera Gracilaria and Gracilariopsis, the taxonomic status of this species is unclear. This present study reassesses the identity of G. irregularis based on morphological features and the large subunit of ribulose‐bisphosphate carboxylase/oxygenase gene sequences. Newly collected samples from the type locality and KU collection were investigated. Our morphological re‐examinations were relatively similar to the original type description, except that the male plants showed superficial chorda‐type spermatangia, an important characteristic recognized in Gracilariopsis. Molecular analysis placed G. irregularis in the Gracilariopsis clade, forming a well‐supported clade with Gracilariopsis bailiniae. Detailed morphology and molecular phylogenetic analyses clearly showed that G. irregularis is congruous with the generic concept of Gracilariopsis, and consequently the new combination of Gracilariopsis irregularis is proposed. We believe that in the original description a heterogeneous holotype was used. Our data also shows the problems that can occur when collections are made of multiple plants, of similar external morphology, to describe new species.
Modelling Spatial Variability in Concentrations of Single Pollutants and Composite Air Quality Indicators in Health Effects Studies
Authors: Powell Helen , Lee Duncan
Published: October 2013

The health impact resulting from a few days of elevated air pollution concentrations has been the focus of much recent research, most of which assesses the effects of single pollutants rather than composite air quality indicators. The average concentrations of these pollutants across the study region are typically estimated by averaging the measurements from the available network of monitors, and this simplistic approach has several deficiencies. Firstly, it is unlikely to be the average concentration across the region under study, owing to the likely non-random placement of the monitoring network. Secondly, the true spatial average is an unknown quantity, and hence the uncertainty in any estimate should be allowed for when estimating its health effects. This paper proposes a novel Bayesian hierarchical framework for addressing these problems, which consists of statistical models for estimating spatially representative measures of single pollutants and composite air quality indicators, and the health effects of these pollution measures while correctly allowing for their uncertainty. This methodological development is motivated by an epidemiological study of the effects of air pollution on respiratory mortality in Greater London, England, between 2003 and 2005. The key findings from this study are that traditional approaches are likely to underestimate the uncertainty in the health effects of air pollution compared with the approach proposed here and increased risks of between 1.4% and 3.1% are associated with 1-standard-deviation increases in the concentrations of ozone, particulate matter (PM10) and the composite air quality indicator that is adopted here.
Human capacity for explosive force production: Neural and contractile determinants
Authors: Folland J. P. , Buckthorpe M. W. , Hannah R.
Published: October 2013

This study assessed the integrative neural and contractile determinants of human knee extension explosive force production. Forty untrained participants performed voluntary and involuntary (supramaximally evoked twitches and octets – eight pulses at 300 Hz that elicit the maximum possible rate of force development) explosive isometric contractions of the knee extensors. Explosive force (F0–150 ms) and sequential rate of force development (RFD, 50‐ms epochs) were measured. Surface electromyography (EMG) amplitude was recorded (superficial quadriceps and hamstrings, 50‐ms epochs) and normalized (quadriceps to Mmax, hamstrings to EMGmax). Maximum voluntary force (MVF) was also assessed. Multiple linear regressions assessed the significant neural and contractile determinants of absolute and relative (%MVF) explosive force and sequential RFD. Explosive force production exhibited substantial interindividual variability, particularly during the early phase of contraction [F50, 13‐fold (absolute); 7.5‐fold (relative)]. Multiple regression explained 59–93% (absolute) and 35–60% (relative) of the variance in explosive force production. The primary determinants of explosive force changed during the contraction (F0–50, quadriceps EMG and Twitch F; RFD50–100, Octet RFD0–50; F100–150, MVF). In conclusion, explosive force production was largely explained by predictor neural and contractile variables, but the specific determinants changed during the phase of contraction.
Epidemiology of ocular surface squamous neoplasia in Africa
Authors: Gichuhi Stephen , Sagoo Mandeep S. , Weiss Helen A. , Burton Matthew J.
Published: October 2013

Objectives

To describe the epidemiology and an aetiological model of ocular surface squamous neoplasia (OSSN) in Africa.

Methods

Systematic and non‐systematic review methods were used. Incidence was obtained from the International Agency for Research on Cancer. We searched PubMed, EMBASE, Web of Science and the reference lists of articles retrieved. Meta‐analyses were conducted using a fixed‐effects model for HIV and cigarette smoking and random effects for human papilloma virus (HPV).

Results

The incidence of OSSN is highest in the Southern Hemisphere (16° South), with the highest age‐standardised rate (ASR) reported from Zimbabwe (3.4 and 3.0 cases/year/100 000 population for males and females, respectively). The mean ASR worldwide is 0.18 and 0.08 cases/year/100 000 among males and females, respectively. The risk increases with exposure to direct daylight (2–4 h, OR = 1.7, 95% CI: 1.2–2.4 and ≥5 h OR = 1.8, 95% CI: 1.1–3.1) and outdoor occupations (OR = 1.7, 95% CI: 1.1–2.6). Meta‐analysis also shows a strong association with HIV (6 studies: OR = 6.17, 95% CI: 4.83–7.89) and HPV (7 studies: OR = 2.64, 95% CI: 1.27–5.49) but not cigarette smoking (2 studies: OR = 1.40, 95% CI: 0.94–2.09). The effect of atopy, xeroderma pigmentosa and vitamin A deficiency is unclear.

Conclusions

Africa has the highest incidence of OSSN in the world, where males and females are equally affected, unlike other continents where male disease predominates. African women probably have increased risk due to their higher prevalence of HIV and HPV infections. As the survival of HIV‐infected people increases, and given no evidence that anti‐retroviral therapy (ART) reduces the risk of OSSN, the incidence of OSSN may increase in coming years.
Bacterial safety of cell‐based therapeutic preparations, focusing on haematopoietic progenitor cells
Authors: Störmer M. , Wood E. M. , Schurig U. , Karo O. , Spreitzer I. , McDonald C. P. , Montag T.
Published: October 2013

Bacterial safety of cellular preparations, especially haematopoietic progenitor cells (HPCs), as well as advanced therapy medicinal products (ATMPs) derived from stem cells of various origins, present a challenge for physicians, manufacturers and regulators. The article describes the background and practical issues in this area and illustrates why sterility of these products cannot currently be guaranteed. Advantages and limitations of approaches both for classical sterility testing and for microbiological control using automated culture systems are discussed. The review considers novel approaches for growth‐based rapid microbiological control with high sensitivity and faster availability of results, as well as new methods for rapid bacterial detection in cellular preparations enabling meaningful information about product contamination within one to two hours. Generally, however, these direct rapid methods are less sensitive and have greater sampling error compared with the growth‐based methods. Opportunities for pyrogen testing of cell therapeutics are also discussed. There is an urgent need for development of novel principles and methods applicable to bacterial safety of cellular therapeutics. We also need a major shift in approach from the traditional view of sterility evaluation (identify anything and everything) to a new thinking about how to find what is clinically relevant within the time frame available for the special clinical circumstances in which these products are used. The review concludes with recommendations for optimization of microbiological control of cellular preparations, focusing on HPCs.
Influence of Boron Carbide on Core Degradation During Severe Accidents in LWRs
Authors: Steinbrück Martin
Published: October 2013

Boron carbide (B4C) is widely used as neutron absorbing control rod material in light water reactors (LWRs). It was also applied in all units of the Fukushima Dai-ichi nuclear power plant. Although the melting temperature of B4C is 2450 °C, it initiates local, but significant melt formation in the core at temperatures around 1250 °C due to eutectic interactions with the surrounding steel structures. The B4C containing melt relocates and hence transports material and energy to lower parts of the fuel bundle. It is chemically aggressive and may attack other structure materials. Furthermore, the absorber melt is oxidized by steam very rapidly and thus contributes to the hydrogen source term in the early phase of a severe accident.

After failure of the control rod cladding B4C reacts with the oxidizing atmosphere. This reaction produces CO, CO2, boron oxide and boric acids, as well as significant amount of hydrogen. It is strongly exothermic, thus causing considerable release of energy. No or only insignificant formation of methane was observed in all experiments with boron carbide.

The paper will summarize the current knowledge on boron carbide behavior during severe accidents, and will try, also in the light of the Fukushima accidents, to draw some common conclusions on the behavior of B4C during severe accidents with the main focus on the consequences for core degradation and hydrogen source term.
Kinetic Study of Sodium-Water Reaction Phenomena by Differential Thermal Analysis
Authors: Kikuchi Shin , Seino Hiroshi , Kurihara Akikazu , Ohshima Hiroyuki
Published: October 2013

In a sodium-cooled fast reactor (SFR), if a heat transfer tube in the steam generator (SG) is failed, high pressurized water vapor blows into the liquid sodium and sodium-water reaction (SWR) takes place. SWR may cause damage to the surface of the neighboring heat transfer tubes by thermal and chemical effects. Therefore, it is important to clearly understand the SWR for safety assessment of the SG.

From recent study, sodium (Na)–sodium hydroxide (NaOH) reaction as secondary surface reaction of the SWR phenomena in a SFR was identified by ab initio method [1]. However, kinetics of this reaction is a still open question. It is important to obtain quantitative rate constant of sodium monoxide (Na2O) generation by Na-NaOH reaction because Na2O may accelerate the corrosive and erosive effects.

Differential thermal analysis (DTA) provides us with the valuable information on the kinetic parameters, including activation energy, pre-exponential factor (frequency factor) and reaction rate constant. Thus, kinetic study of Na–NaOH reaction has been carried out by using DTA technique. The parameters, including melting points of Na and NaOH, phase transition temperature of NaOH, Na-NaOH reaction temperature and the decomposition temperature of sodium hydride (NaH) were identified from DTA curves. Na, NaOH, and Na2O as major chemical species were observed from the X-ray diffraction (XRD) analysis of the residues after the DTA experiment. It was inferred that Na2O could be generated as a reaction product. Based on the measured reaction temperature, the first-order rate constant of Na2O generation was obtained by the application of the laws of chemical kinetics. From the estimated rate constant, it was found that Na2O generation should be considered during SWR.

The results can be the basis for developing a chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by the Japan Atomic Energy Agency (JAEA) toward the safety assessment of the SG in a SFR.
On Distribution of Local Thermal and Mass Flow Rate Parameters of Two-Phase Coolant in the Bundle of 7 Rods
Authors: Dalipagich V. A. , Mayevskiy E. M. , Razumovskiy V. G. , Pis’mennyi E. N. , Koloskov A. E. , Pioro I. L.
Published: October 2013

Distribution of thermal and mass flow rate parameters of coolant in the cross-section of 7-rod bundle consisting of the tubes of 6.0-mm outside diameter and 1.0-m heated length for two types of discretization of its cross-section into characteristic cells is experimentally investigated by the method of isokinetic sampling. The range of operation parameters corresponds to the conditions of LOCA accompanied by pressure and flow rate decrease relative to the nominal ones and is as follows: bundle-averaged outlet vapor content varies from −0.6 to 0.2, outlet pressure is 6 and 10 MPa, bundle-averaged mass velocity varies from 300 to 1500 kg/(m2s), inlet temperature varies from deep subcooling to (ts − 20) °C, and heat flux rate reaches 1.0 kJ/kg.

It is confirmed by the experiment that the surface in the gap between the peripheral rods is most probable place of burnout in the bundle. Physical model of two-phase flow in the bundle that considers it as the equivalent annular channel with an eccentricity is proposed. The programs of thermal-hydraulic computation of fuel assembly and their adaptation to the experimental data for the two types of discretization into characteristic cells are performed and comparative assessment of them is made.

The data resulted from the study concerning one-phase coolant could be applicable for a reference estimation of heat transfer in future designs of the fuel bundles.
Assessment of Heat-Transfer Correlations Against Experimental Data Obtained With Supercritical Water in Vertical Annuli
Authors: Yang Zhendong , Bi Qincheng , Wang Han , Wu Gang , Leung Laurence K. H.
Published: October 2013

Eleven correlations proposed for supercritical heat-transfer coefficients were assessed against a set of experimental data obtained recently with supercritical water flow in a vertical annular test section at Xi’an Jiaotong University. The inner heated rod of the test section had an outer diameter of 8 mm, while the outer unheated tube had an inner diameter of 16 mm (resulting in a gap size of 4 mm). The experiment covered pressure range from 23 to 28 MPa, mass-flux range from 350 to 1000 kg/m2s, and heat-flux range from 200 to 1000 kW/m2. The assessment shows relatively good agreement between predicted and experimental heat-transfer coefficients for several correlations. Some discrepancies have been observed at the region where deteriorated heat transfer, and are attributed to the modified Dittus-Boelter formulation that captures mainly the normal heat-transfer region. Overall, the Dittus-Boelter correlation is shown applicable only for the normal heat-transfer region, and significantly overpredicts the heat-transfer coefficient at the deteriorated heat-transfer region. The correlation of Bishop et al. appears valid for the current experimental database, particularly for high mass fluxes.
Simulation of a Reinforced Concrete Slab Punching Impact
Authors: Kähkönen Jukka , Varpasuo Pentti
Published: October 2013

Reinforced concrete wall subjected to an impact by a hard steel missile with a mass of 47 kg and an impact velocity of 135 m/s was one case study in the IRIS 2010 benchmark exercise in OECD/NEA/CSNI/IAGE framework. The wall had dimensions of 2m × 2m × 0.25m and it was simply supported. The perforation of the missile was expected.

Fortum Power and Heat Ltd. participated in the benchmark. In this paper, we present our modeling and blind prediction of the benchmark case. The test results of the benchmark were released after the predictions were made.

Based on the result comparison, we concluded that our model gave conservative results.
Numerical Study of Flow and Heat Transfer in Rectangular Channel With Periodic Longitudinal Vortex Generators Under Pulsating Flow
Authors: Tian Lin , Bai Wei , Xue Shanhu , Huang Zipeng , Wang Qiuwang
Published: October 2013

The unsteady turbulent flow and heat transfer in rectangular channel with periodic longitudinal vortex generators on up and bottom walls are investigated by standardized k-ε two equation turbulent model combined with standardized wall function which has been validated by steady experimental data. Influence of varying frequency and amplitude of inlet velocity varying by sine function on heat transfer and friction factor are discussed. It is found that parameters such as Tout, Tf, Tw, Nusselt number and the friction factor f vary with time periodically, phase difference occurred compared with inlet velocity. Pulsating frequency has little impact on time averaged Nusselt number. However, when amplitude increases from 0.2us to 0.8us, the heat transfer rate is augmented by about 4%. Furthermore, a critical frequency has been captured when amplitude equals to 0.8us for the channel studied. The current study will deepen understanding of unsteady flow in plate fuel assembly, which can be used in small-scale reactors.
Nuclear Fuel Burn-Up Depth in WWER Reactors With Various Burnable Absorbers
Authors: Zaiets Vasyl
Published: October 2013

An overview of relationship between nuclear fuel burn-up depth and absorbers used is made. Gd2O3, PuO2, and mixture of transuranium elements as absorbers for NPP with WWER reactors are considered. The results of comparative design research of fuel burn-up under conditions of open and closed nuclear fuel cycle are represented.
Study on Resistance Characteristics of Single-Phase Pulsating Flow in the Horizontal Rectangular Channel
Authors: Tian Jing-da , Gao Pu-zhen , Zhou Bao
Published: October 2013

The resistance characteristic of single-phase pulsating flow was experimentally investigated. Using de-ionized water, experiments were conducted in the horizontal rectangular channel with 5.647mm inner diameter, considering three factors that were average flow, pulsation amplitude and pulsation period. Experiments focused on the turbulent region, and the atmospheric pressure and temperature conditions were maintained throughout the experiments. It was found that compared with steady flow in the same channel, the friction coefficient λ under the pulsating conditions was not only affected by the Reynolds number Re, but was also related to pulsation period and pulsation amplitude. And under the pulsating conditions, the Re-λ curve became pulsation circle, it resulted from the acceleration acting on the fluid and the phase difference between Re and λ.
Experimental Investigation of Cavitation in the Circulation Pumps With Lead and Lead-Bismuth Coolants
Authors: Lvov A. V. , Bokov P. A. , Shumilkov A. I. , Novozhilova O. O. , Beznosov A. V.
Published: October 2013

The purpose of this paper is optimization of methods for calculating of flow parts of impeller pumps for high-temperature lead coolant, taking into account specific cavitation performance of the lead coolant [1].

The article presents the studies of cavitation performance of the high-temperature coolant.

The studies were conducted in the lead coolant medium at 450–550 °C, flow rate up to 25–30 m/s and lead flow pressure from 0 to 5.0 kgf/cm2 (atm), at oxygen content in lead from 10−5–10−4 up to saturation, as well as in the presence of solid phase of lead oxides in the flow and in the experimental loop with such coolant.

With a view to improving the representativeness of the research results, conditions of occurrence and characteristics of gaseous cavitation in the lead coolant flow were determined using three independent methods [2, 3].

The research showed that gas cavitation can take place in lead flows in the vane-type pumps and other components of circulation loops followed by apertures of lead flow discontinuity (bubbles, caverns, etc.), filled up with diluted gas with subsequent disappearance of these apertures of flow discontinuity. Traditional cavitation with formation and subsequent collapse of lead vapors in reactor loops with lead and lead-bismuth coolant is not possible.

Cavitation performance of lead coolant is identified.
Scaling Evaluation of the Two-Phase Natural Circulation
Authors: Wang Han , Li Yuquan
Published: October 2013

This paper presented the scaling evaluation of the two-phase natural circulation process between an assumed nuclear power plant and three test facilities with full pressure simulation and three different height scales, which were 1:2, 1:3 and 1:4. The Hierarchical Two-Tiered Scaling (H2TS) Methodology was adopted. By top-down scaling analysis, several characteristic time ratios were obtained, and then the calculation method of the scaling distortion were investigated. It has been found that the dominant processes in two-phase natural circulation can be well preserved no matter what the height scale is.
ACME Upper Plenum Entrainment Phenomena Scaling Analysis and Criteria
Authors: Ye Zishen , Li Yuquan , Wang Han , Chen Lian , Li Wei
Published: October 2013

ACME (Advanced Core-cooling Mechanism Experiment) is an integral thermal-hydraulic facility designed to produce data for validating the software that is intended to be used to calculate the behavior of large advanced PWRs in China. Design of ACME is working on now. ACME would simulate the important phenomenon of the reactor cooling system and passive core cooling system of PWR. When the level is lower than the hot leg nozzles, droplets would be carried out by the vapor. This phenomenon is entrainment of upper plenum. Entrainment is a important phenomena in the upper plenum both of prototype and test facility. It would influence the level and inventory of the core. We analyzed entrainment phenomena in the upper plenum through H2TS scaling analysis method [1] based on Ishii’s pool entrainment model [2] in this paper. H2TS scaling analysis method includes two parts: one is the top-down system scaling and the other is the bottom-up process scaling analysis. Ishii’s pool entrainment model define the entrainment as the ratio of the droplet to vapor mass flux and divide three regions by the diameter and velocity of the droplet, including near surface region, momentum controlled region and deposition controlled region. The key scaling criteria and scaling ratios which should be met under ACME design are given for different entrainment regions. Based on these criteria and ratios, ideal upper plenum design of ACME facility will simulate the entrainment phenomena conservatively.