bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional up‐regulation of endopeptidase neurolysin during post‐acute and early recovery phases of experimental stroke in mouse brain
Authors: Rashid Mamoon , Wangler Naomi J. , Yang Li , Shah Kaushik , Arumugam Thiruma V. , Abbruscato Thomas J. , Karamyan Vardan T.
Published: October 2013

In this study, we provide evidence for the first time that membrane‐bound endopeptidase neurolysin is up‐regulated in different parts of mouse brain affected by focal ischemia‐reperfusion in a middle cerebral artery occlusion model of stroke. Radioligand binding, enzymatic and immunoblotting experiments in membrane preparations of frontoparietal cortex, striatum, and hippocampus isolated from the ischemic hemisphere of mouse brain 24 h after reperfusion revealed statistically significant increase (≥ twofold) in quantity and activity of neurolysin compared with sham‐operated controls. Cerebellar membranes isolated from the ischemic hemisphere served as negative control supporting the observations that up‐regulation of neurolysin occurs in post‐ischemic brain regions. This study also documents sustained functional up‐regulation of neurolysin in frontoparietal cortical membranes for at least 7 days after stroke, which appears not to be transcriptionally or translationally regulated, but rather depends on translocation of cytosolic neurolysin to the membranes and mitochondria. Considering diversity of endogenous neurolysin substrates (neurotensin, bradykinin, angiotensins I/II, substance P, hemopressin, dynorphin A(1‐8), metorphamide, somatostatin) and the well‐documented role of these peptidergic systems in pathogenesis of stroke, resistance to ischemic injury and/or post‐stroke brain recovery, our findings suggest that neurolysin may play a role in processes modulating the brain's response to stroke and its recovery after stroke.

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We provide evidence that peptidase neurolysin is up‐regulated in the mouse brain membranes after stroke. Neurolysin metabolizes several neuropeptides in the brain (neurotensin, bradykinin, angiotensins I and II, substance P, hemopressin, dynorphin A(1‐8), metorphamide, somatostatin), which have various functions in stroke pathophysiology. We hypothesize that neurolysin plays a key role in processes modulating the brain's response to stroke and its recovery after stroke.
The Relationship between Retirement Wealth and Householders' Lifetime Personal Financial and Investing Behaviors
Authors: ECCLES DAVID W. , WARD PAUL , GOLDSMITH ELIZABETH , ARSAL GULER
Published: October 2013

While previous research indicates wide wealth dispersion at retirement within households with similar lifetime incomes, there have been few attempts to identify personal financial behaviors associated with retirement wealth in households matched for lifetime income. Householders with similar demographics and lifetime income but differing markedly in net worth near retirement were surveyed in terms of personal financial behaviors undertaken during their lifetime. Results revealed key differences between householders with low and high retirement wealth in their financial behaviors and how these were acquired.
Does spirituality really matter?: A study on the potential of spirituality for older adult's adjustment to aging
Authors: von Humboldt Sofia , Leal Isabel , Pimenta Filipa
Published: October 2013

This study intended to analyze the indicators of adjustment to aging (AtA) and to investigate the latent constructs that can work as major determinants in spirituality for a cross‐national older community‐dwelling population. Questionnaires were completed to assess the participants' background information. Interviews were performed, addressing one core area: indicators of AtA. Complete data were available for 154 older adults from two nationalities (German and Portuguese), aged between 75 and 103 years (M = 86.6; SD = 6.98). The data were subjected to content analysis. Representations of the associations and latent constructs were analyzed using a multiple correspondence analysis (MCA). The most prevalent response of the interviewed participants for indicators of AtA was spirituality (43.2%). Spiritual activities was the most reported response regarding spirituality (20.0%). A significant moderate association was found between spiritual activities and nationality (V = .365; p < .001). Spirituality for older adults was explained by a three‐dimensional overall model: spiritual and existential meaning, limit‐related awareness and community embeddedness. The findings presented in this paper emphasized the need to explore the potential of spirituality for AtA and the need for improving the spiritual dimension of health care for the older cross‐national population.
Intraoperative identification of canine hepatocellular carcinoma with indocyanine green fluorescent imaging
Authors: Iida G. , Asano K. , Seki M. , Ishigaki K. , Teshima K. , Yoshida O. , Edamura K. , Kagawa Y.
Published: October 2013

Objectives

To evaluate the feasibility of high‐sensitivity near‐infrared fluorescence imaging with indocyanine green for intraoperative identification of hepatocellular carcinoma in dogs.

Methods

Twelve hepatic nodules were surgically resected from six dogs. In each dog, 0 · 5 mg/kg indocyanine green was intravenously injected for 12 to 18 hours preoperatively. The hepatic nodules were investigated under laparotomy using a near‐infrared fluorescence imaging light camera system prior to resection. Resected nodules were histopathologically diagnosed and their fluorescence images were evaluated.

Results

Of the 12 hepatic nodules, 6 were diagnosed as hepatocellular carcinoma and 6 as nodular hyperplasia. Indocyanine green‐fluorescence was observed in four large hepatocellular carcinoma nodules and one case of nodular hyperplasia, whereas it was absent in the remaining nodules. The sensitivity and positive predictive values of indocyanine green fluorescent imaging for hepatocellular carcinoma was 71 · 4 and 80 · 0%, respectively. Complete resection of the hepatic masses was achieved in all dogs.

Clinical Significance

Near‐infrared fluorescence imaging may be feasible for intraoperative mapping of hepatocellular carcinomas in hepatic lobes and may help increase the chance of complete resection of hepatocellular carcinoma in dogs.
Physiological hypoxia prevents bile salt‐induced apoptosis in human and rat hepatocytes
Authors: Hohenester Simon , Vennegeerts Timo , Wagner Michaela , Wimmer Ralf , Drolle Heidrun , Rieger Christina , Denk Gerald U. , Rust Christian , Fiegl Michael
Published: October 2013

Background & Aims

Hydrophobic bile salts such as glycochenodeoxycholate (GCDC) accumulate in cholestatic liver disease and induce hepatocellular apoptosis, promoting profibrotic signalling. The tissue microenvironment is an integral player in cellular pathophysiology, but it is not routinely incorporated into laboratory studies. Tissue oxygen partial pressure (pO2) may be an underestimated component of the microenvironment: in the liver, a pO2 of 30–45 mmHg (approximately 6% O2) is physiological, because of predominant portal blood supply. It was the aim of this project to investigate the impact of physiological hypoxia (i.e. 6% O2) on hepatocellular function, namely, bile salt‐induced apoptosis.

Methods

Human hepatoma cells (HepG2‐Ntcp) and primary rat hepatocytes were cultured at standard laboratory (hyperoxic) conditions (21% O2) and at physiological hypoxia (6% O2) in parallel for 1–8 days to study hepatocellular apoptosis and activation of signalling pathways. Standard laboratory analyses were applied for bile salt uptake, caspase‐3/‐7 activity, western blotting and gene‐array analysis.

Results

Culturing at physiological hypoxia protected both human and rat hepatocytes against GCDC‐induced apoptosis: caspase‐3/‐7 activation was diminished by 3.1 ± 0.5‐fold in human HepG2‐Ntcp and completely abolished in primary rat hepatocytes. Bile salt uptake was unaffected. Induction of hypoxia‐inducible factor‐1α indicated adaption to physiological hypoxia. The MEK/ERK cascade was activated and anti‐apoptotic mediators were induced: N‐Myc down‐regulated gene, gelsolin and carbonic anhydrase IX were upregulated 12.4‐, 6.5‐ and 5.2‐fold respectively.

Conclusions

We conclude from these data that (i) physiological hypoxia protects hepatocytes from bile salt‐induced apoptosis, (ii) tissue pO2 is a crucial, underestimated component of the microenvironment and should (iii) be considered when studying hepatocellular physiology in vitro.
Evidence of rebalanced coagulation in acute liver injury and acute liver failure as measured by thrombin generation
Authors: Habib Mohamed , Roberts Lara N. , Patel Raj K. , Wendon Julia , Bernal William , Arya Roopen
Published: October 2013

Background & Aims

Patients with liver disease often show profound abnormalities in their haemostatic system. Studies using thrombin generation demonstrate rebalanced coagulation in patients with chronic liver disease. Our aim was to evaluate the haemostatic profile in patients with acute liver injury/failure (ALI/ALF) compared with healthy controls.

Methods

Thrombin generation was measured in the presence and absence of thrombomodulin (TM) to activate protein C (PC) with endogenous thrombin potential (ETP; the area under the thrombin generation curve) a key parameter. Routine coagulation assays were also performed.

Results

Thirty two patients with ALI/ALF and 40 controls were recruited. Patients had grossly abnormal coagulation profiles with decreased pro‐ and anticoagulant factors compared with controls (P < 0.001 for all comparisons), except for median Factor VIII which was increased 247 U/dl [interquartile range: 214–347] in patients compared with 120 U/dl [97–139; P < 0.001] in controls. Mean ETP was significantly lower in patients 886 nM.min (± 436) compared with controls 1596 nM.min (± 259; P < 0.001). However, when the assay was repeated with TM to activate PC, there was no significant difference in mean ETP + TM between patients and controls (632 ± 418 vs 709 ± 301 nM.min respectively; P = 0.666). Furthermore, the ETP ratio (ETP + TM/ETP) was significantly higher in patients 0.89 (0.60–0.97) compared with controls 0.48 (0.3–0.6; P = 0.002) and negatively correlated with PC (R = −0.487, P = 0.003) and Factor V (R = −0.431, P = 0.01).

Conclusion

ALI/ALF patients have normal ETP in the presence of TM. This supports rebalanced coagulation mediated by acquired PC resistance because of the reduction in PC, Factor V and concomitant increase in Factor VIII.
Continued low uptake of treatment for hepatitis C virus infection in a large community‐based cohort of inner city residents
Authors: Alavi Maryam , Raffa Jesse D. , Deans Gregory D. , Lai Calvin , Krajden Mel , Dore Gregory J. , Tyndall Mark W. , Grebely Jason
Published: October 2013

Background & Aims

Despite advances in HCV treatment, recent data on treatment uptake is sparse. HCV treatment uptake and associated factors were evaluated in a community‐based cohort in Vancouver, Canada.

Methods

The CHASE study is a cohort of inner city residents recruited from January 2003–June 2004. HCV status and treatment were retrospectively and prospectively determined through data linkages with provincial virology and pharmacy databases. Logistic regression analyses were used to identify factors associated with HCV treatment uptake.

Results

Among 2913, HCV antibody testing was performed in 2405, 64% were HCV antibody‐positive (n = 1533). Individuals with spontaneous clearance (18%, n = 276) were excluded. Among the remaining 1257 HCV antibody‐positive participants (mean age 42, 71% male), 29% were Aboriginal. At enrolment, the majority reported recent injecting (60%) and non‐injecting drug use (87%). Between January 1998 and March 2010, 6% (77 of 1257) initiated HCV treatment. In adjusted analyses, Aboriginal ethnicity [adjusted odds ratio (AOR) 0.23; 95% CI 0.10, 0.51] and crack cocaine use (AOR 0.61; 95% CI 0.37, 0.99) were associated with a decreased odds of receiving HCV treatment, while methamphetamine injecting (AOR 0.16; 95% CI 0.02, 1.18) trended towards a lower odds of receiving treatment. HCV treatment uptake ranged from 0.2 (95% CI 0.0, 0.7) per 100 person‐years (PYs) in 2003 to 1.6 (95% CI 0.9, 2.6) per 100 PYs in 2009.

Conclusion

HCV treatment uptake remains low in this large community‐based cohort of inner city residents with a high HCV prevalence and access to universal healthcare.
Biodiversity, ecological structure, and change in the sponge community of different geomorphological zones of the barrier fore reef at Carrie Bow Cay, Belize
Authors: Villamizar Estrella , Díaz María C. , Rützler Klaus , De Nóbrega Renato
Published: October 2013

Changes in the relative abundance of benthic groups on the barrier fore reef at Carrie Bow Cay, Belize, point to a significant reduction of corals and an expansion of the sponge community in 1995–2009. Fifty‐one species are now present in the four geomorphological zones of this reef: the low‐relief spur‐and‐groove zone, the inner reef slope, the outer ridge, and the fore‐reef slope (to a depth of 30 m). Five species are new additions to the sponge fauna reported for Belize, and six species account for 42.6% of the total assemblage: Niphates erecta (9.60%), Aiolochroia crassa (8.8%), Niphates digitalis (6.9%), Callyspongia plicifera (6.63%), Aplysina archeri (5.37%) and Xestospongia muta (5.37%). Species richness, average density, diversity and evenness indexes are statistically similar in these four zones but some species appear to be more dominant in certain areas. In the same 30 years, coral cover has decreased by more than 90%, while the octocoral cover has greatly increased (by as much as 10‐fold in the low‐relief spur‐and‐groove zone). Thus the Carrie Bow fore reef appears to be undergoing a transition from coral dominance in the late 1970s to algae dominance today, with other benthic groups such as sponges and octocorals showing signs of gradual recovery.
TNFα contributes for attenuating both Y397FAK and Y416Src phosphorylations in osteoblasts
Authors: Cavagis ADM , Takamori ER , Granjeiro JM , Oliveira RC , Ferreira CV , Peppelenbosch MP , Zambuzzi WF
Published: October 2013

Objective

Our poor understanding of how inflammatory mediators can affect osteoblast behavior led us to investigate the tumor necrosis factor (TNF)α‐induced focal adhesion kinase (FAK) and Src phosphorylation.

Material and Methods

MC3T3‐E1 pre‐osteoblast cells were harvested at specific time points after either TNFα treatment or RAW267 stimulated conditioned medium, and thereafter cell extracts were prepared for Immunoblotting assay. ELISA detected TNFα content at conditioned medium. Tumor necrosis factor‐α‐neutralizing antibodies also were used.

Results

It was possible to show that TNFα provokes attenuation at Y‐phosphorylation of both FAK (at Y397) and Src (at Y416) proteins (P < 0.05), suggesting a decrease in their activities. The very similar profile was observed when osteoblasts were incubated with conditioned medium from lipopolysaccharide (LPS)‐stimulated macrophages, it being significantly different than control (FAK and Src, P < 0.05). Nevertheless, in order to validate these findings, we decided to pre‐incubate osteoblasts with anti‐TNFα neutralizing antibody (2 μg ml−1) prior exposing to conditioned medium. Importantly, our results revealed that there was a diminution on those conditioned medium effects when the same biological parameters were evaluated (P < 0.05). Moreover, we also showed that TNFα impairs osteoblast adhesion, suggesting an interesting role on osteoblast performance.

Conclusions

Altogether, these results suggest that LPS‐stimulated macrophage mediators attenuate both FAK and Src activations in osteoblast, suggesting a novel role for TNFα on osteoblast performance.
Antimicrobial Photodynamic Efficiency of Novel Cationic Porphyrins towards Periodontal Gram‐positive and Gram‐negative Pathogenic Bacteria
Authors: Prasanth Chandra Sekhar , Karunakaran Suneesh C. , Paul Albish K. , Kussovski Vesselin , Mantareva Vanya , Ramaiah Danaboyina , Selvaraj Leslie , Angelov Ivan , Avramov Latchezar , Nandakumar Krishnankutty , Subhash Narayanan
Published: October 2013

The Gram‐negative Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum are major causative agents of aggressive periodontal disease. Due to increase in the number of antibiotic‐resistant bacteria, antimicrobial Photodynamic therapy (aPDT) seems to be a plausible alternative. In this work, photosensitization was performed on Gram‐positive and Gram‐negative bacteria in pure culture using new‐age cationic porphyrins, namely mesoimidazolium‐substituted porphyrin derivative (ImP) and pyridinium‐substituted porphyrin derivative (PyP). The photophysical properties of both the sensitizers including absorption, fluorescence emission, quantum yields of the triplet excited states and singlet oxygen generation efficiencies were evaluated in the context of aPDT application. The studied porphyrins exhibited high ability to accumulate into bacterial cells with complete penetration into early stage biofilms. As compared with ImP, PyP was found to be more effective for photoinactivation of bacterial strains associated with periodontitis, without any signs of dark toxicity, owing to its high photocytotoxicity.
Daytime sleepiness: a risk factor for poor social engagement among the elderly
Authors: Lee Yao‐Tung , Tsai Chia‐Fen , Ouyang Wen‐Chen , Yang Albert C. , Yang Cheng‐Hung , Hwang Jen‐Ping
Published: October 2013

Background

The aim of this study was to investigate the relationship between social engagement and daytime sleepiness among aged residents of a veterans' housing facility in Taiwan.

Methods

A total of 597 men were enrolled in this cross‐sectional study. Each subject was assessed with the Resident Assessment Instrument‐Minimum Data Set, Geriatric Depression Scale, Pittsburgh Sleep Quality Index, and Mini‐Mental State Examination. Social engagement was measured with the Index of Social Engagement (ISE), and daytime sleepiness was defined according to the relevant Pittsburgh Sleep Quality Index subcomponent. Subjects were divided into two groups according to their ISE levels. A multivariate logistic regression model was used to examine the association between ISE and other variables.

Results

The sample's mean age was 80.8 ± 5.0 years (range: 65–99 years). Mean ISE score was 1.5 ± 1.3 (range 0–5), with 52% of participants reporting poor social engagement (ISE = 0–1). Mean Pittsburgh Sleep Quality Index global score was 5.6 ± 3.6 (range: 0–18), and 31% of participants reported daytime sleepiness. The analysis was adjusted for level of depression, cognitive impairment, dependence in activities of daily life, unsettled relationships, and illiteracy. After adjustment, daytime sleepiness was found to be independently associated with subjects' level of social engagement (odds ratio: 2.5; 95% confidence interval: 1.7–3.8; P < 0.001).

Conclusions

Daytime sleepiness and poor social engagement are common among aged residents of a veterans' housing facility. Subjects experiencing daytime sleepiness but not poor general sleep quality were at increased risk of poor social engagement. The clinical care of older residents must focus on improving daytime sleepiness to enhance their social engagement.
Levodopa treatment and mood fluctuation in dementia with Lewy bodies: a case report
Authors: Fujishiro Hiroshige , Kasanuki Koji , Nakamura Shinichiro
Published: October 2013

L‐3,4‐dihydroxyphenylalanine (L‐dopa) has been the gold standard for pharmacotherapy for parkinsonism in patients with dementia with Lewy bodies (DLB). While L‐dopa treatment is related to visual hallucinations, its relationship to mood fluctuation in DLB is poorly understood. Herein, we report the improvement of behavioural and psychological symptoms of dementia through the adjustment of L‐dopa treatment in a 78‐year‐old woman with probable DLB. Her marked mood swings were improved by changing L‐dopa administration from three to five times per day while maintaining the same total daily dosage. This observation suggests that there may be an association between plasmatic L‐dopa levels and mood fluctuation in patients with DLB. This pharmacological approach may be useful in the management of behavioural and psychological symptoms of dementia without the use of antipsychotic agents to avoid severe neuroleptic sensitivity, which is one of the suggestive clinical features in the Third Consortium on DLB clinical criteria.
Exacerbation phenotyping in chronic obstructive pulmonary disease
Authors: MacDonald Martin , Korman Tony , King Paul , Hamza Kais , Bardin Philip
Published: October 2013

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are crucial events but causes remain poorly defined. A method to clinically ‘phenotype’ AECOPD have been proposed, and 52 hospitalized chronic obstructive pulmonary disease exacerbations according to underlying aetiology have now been prospectively phenotyped. Multiple exacerbation phenotypes were identified. A subpopulation coinfected with virus and bacteria had a significantly longer length of hospital stay, and this pilot study indicates that exacerbation phenotyping may be advantageous.
Earthquake‐affected development of a travertine ridge
Authors: Gradziński Michał , Wróblewski Wojciech , Duliński Marek , Hercman Helena
Published: October 2013

Although the relation between travertine and tectonics is commonly accepted, the influence of seismic activity on the internal structures and facies development of travertine has not been examined extensively. The aim of this paper was to unravel the impact of seismic shocks on the anatomy of a travertine mound. Dreveník travertine in the Central Western Carpathians of Slovakia was studied using detailed facies analysis, based on fieldwork coupled with microscope and stable isotope studies. The travertine formed a ridge fed by ascending water of deep circulation, charged with CO2 of geogenic origin. The location of the ridge over an impermeable Palaeogene flysch complex and the stable isotope composition of the travertine support the above interpretation. The ridge is composed of crystalline crust travertine, lithoclast travertine, fine‐grained lithoclast travertine, paper‐thin raft travertine and coated bubble travertine. The travertine underwent brittle deformations resulting in formation of fissures and intraclast breccia. Several lines of evidence prove that the deformations occurred during travertine deposition: (i) breccias are covered by undisturbed layers of travertine; (ii) ground fissures are filled with younger travertine; and (iii) calcite filling fissures and cementing breccia crystallized from water with the same isotopic composition as the travertine. The deformations resulted from seismic shocks which also triggered rockfall avalanches that led to the destruction of the upper part of the travertine slope and deposition of lithoclast travertine on its lower parts. Local hydrological conditions changed after the shocks, favouring ponding of water which, in turn, led to formation of paper‐thin raft travertine over lithoclast travertine. Thus, earthquakes exerted an important control on the development of the studied travertine mound. It is plausible that earthquakes have impacted other travertine mounds and influenced their facies development.
Transcription factor HAT1 is phosphorylated by BIN2 kinase and mediates brassinosteroid repressed gene expression in Arabidopsis
Authors: Zhang Dawei , Ye Huaxun , Guo Hongqing , Johnson Abbagail , Zhang Meishan , Lin Honghui , Yin Yanhai
Published: October 2013

Plant steroid hormones, brassinosteroids (BRs), play essential roles in modulating cell elongation, vascular differentiation, senescence and stress responses. BRs signal through plasma membrane‐localized receptor and other components to modulate the BES1/BZR1 (BRI1‐EMS SUPPRESSOR 1/BRASSINAZOLE RESISTANT 1) family of transcription factors that modulate thousands of target genes. Arabodopsis thaliana homeodomain‐leucine zipper protein 1 (HAT1), which encodes a homeodomain‐leucine zipper (HD‐Zip) class II transcription factor, was identified through chromatin immunoprecipitation (ChIP) experiments as a direct target gene of BES1. Loss‐of‐function and gain‐of‐function mutants of HAT1 display altered BR responses. HAT1 and its close homolog HAT3 act redundantly, as the double mutant hat1 hat3 displayed a reduced BR response that is stronger than the single mutants alone. Moreover, hat1 hat3 enhanced the phenotype of a weak allele of the BR receptor mutant bri1 and suppressed the phenotype of constitutive BR response mutant bes1‐D. These results suggest that HAT1 and HAT3 function to activate BR‐mediated growth. Expression levels of several BR‐repressed genes are increased in hat1 hat3 and reduced in HAT1OX, suggesting that HAT1 functions to repress the expression of a subset of BR target genes. HAT1 and BES1 bind to a conserved homeodomain binding (HB) site and BR response element (BRRE) respectively, in the promoters of some BR‐repressed genes. BES1 and HAT1 interact with each other and cooperate to inhibit BR‐repressed gene expression. Furthermore, HAT1 can be phosphorylated and stabilized by GSK3 (GLYCOGEN SYNTHASE KINASE 3)‐like kinase BIN2 (BRASSINOSTEROID‐INSENSITIVE 2), a well established negative regulator of the BR pathway. Our results thus revealed a previously unknown mechanism by which BR signaling modulates BR‐repressed gene expression and coordinates plant growth.
The p.R168Q mutation is associated with the Bw phenotype and a predicted decrease in the stability of the resulting ABO glycosyltransferase
Authors: Lee Seung Yeob , Ihm Chunhwa , Shin Dong‐Jun , Lee Ho‐Jin , Yazer Mark Harris , Kim Seung Yeon , Shin Myung Geun , Shin Jong Hee , Suh Soon Pal , Ryang Dong Wook , Cho Duck
Published: October 2013

Background

Mutation of ABO glycosyltransferase (GT) can cause protein stability changes that can result in a weak ABO phenotype. To explain the Bw phenotype of a novel ABO*Bw allele, a protein stability of the mutant GT, which enhances the information of the three‐dimensional (3D) structural analysis, was calculated.

Study Design and Methods

ABO serology and genotyping were performed on a neonate and her five family members. A 3D structural analysis of the wild‐type GTB and enzymes with a variety of mutations at Residue 168, along with predicted protein stability changes (ΔΔG) and flow cytometric analysis of ABO antigen expression on HeLa cells transfected with plasmids containing R168Q, R168L, and R168P mutants was also performed.

Results

A novel ABO*Bw allele (c.503G>A, p.R168Q) was discovered. The structural analysis of 3D homology modeling predicted reduced protein stability of the mutant GTB, and the ΔΔG values, which inversely correlated with the mean relative fluorescence intensity of ABO antigen expression, quantitatively explained the reduced ABO antigen expression.

Conclusions

The predicted protein stability change of a mutant GT enzyme might be a useful and convenient approach to objectively and quantitatively explain the reduced ABO antigen expression.
Reduced use of allogeneic platelets through high‐yield perioperative autologous plateletpheresis and reinfusion
Authors: Alberts Melissa , Bandarenko Nicholas , Gaca Jeffrey , Lockhart Evelyn , Milano Carmelo , Alexander Stanlin , Linder Dean , Lombard Frederick W. , Welsby Ian J.
Published: October 2013

Background

Intraoperative autologous platelet (PLT) collection as part of a multimodal blood conservation program carries a Class IIa recommendation from the Societies of Thoracic Surgeons and Cardiovascular Anesthesiologists, but achieving a suitable PLT yield limits its application. A novel, autologous, intraoperative, high‐yield plateletpheresis collection program was established and retrospectively analyzed to identify potential improvements over previously reported plateletpheresis protocols.

Study Design and M‐ethods

Targeting complex cardiothoracic surgery patients without recent anti‐PLT agents, thrombocytopenia, or severe anemia, the program aimed to achieve a PLT yield of at least one standard apheresis unit (3.0 × 1011) within 60 to 90 minutes and using an automated plateletpheresis device (Trima, Terumo BCT). Anesthetized and invasively monitored patients underwent plateletpheresis via a large‐bore, indwelling central line placed for the surgery. Collection‐related data for quality control purposes and subsequent PLT transfusion requirements were analyzed and reported.

Results

Forty‐two patients donated autologous PLTs between 2011 and 2012. PLT yield was 4.5 (3.9‐5.0) × 1011, which significantly exceeds previously reported yields, and procedure duration was 53.2 (48.4‐57.9) minutes. As anticipated, postcollection PLT count decreased from 268 (242‐293) × 109 to 182 (163‐201) × 109/L; hypocalcemia was minimized by infusion of 1 g of CaCl2. Autologous PLT yield was inversely correlated with allogeneic PLT use, and avoidance of allogeneic PLT transfusion was increased when the autologous yield was the equivalent of 2 or more apheresis units.

Conclusion

High‐yield, intraoperative autologous PLT collection is achievable using an automated plateletpheresis device. Initial experience shows a reduction in reliance on allogeneic PLTs for complex cardiothoracic surgery.
Wnt5a expression in canine osteosarcoma
Authors: Szigetvari N. , Imai D. M. , Piskun C. M. , Rodrigues L. C. S. , Chon E. , Stein T. J.
Published: October 2013

Osteosarcoma is the most common primary malignancy of bone in dogs and is associated with poor long‐term outcomes due to its highly metastatic nature. A better understanding of the signalling pathways and proteins involved with osteosarcoma pathogenesis may aid in improved outcomes through the use of targeted therapies. The Wnt5a protein, a ligand for the non‐canonical Wnt signalling pathway, is implicated in mediating the aggressiveness of cancer cell lines, including those of human osteosarcoma origin. Given the close relationship between human and canine osteosarcoma, the primary goal of this study was to characterize Wnt5a expression in canine osteosarcoma. Second, if Wnt5a expression was present in canine osteosarcoma, the study aimed to determine any potential association with clinical outcome and clinical variables in similarly treated osteosarcoma‐bearing dogs. Wnt5a expression was present in 26 of the 48 (54%) cases of canine osteosarcoma. Wnt5a expression was not associated with progression‐free survival (P = 0.4) or overall survival (P = 0.1).
Design and Experimental Validation of Compact, Quick-Response Shape Memory Alloy Separation Device
Authors: Zhang Xiaoyong , Yan Xiaojun , Yang Qiaolong
Published: October 2013

The shape memory alloy (SMA)-actuated separation devices that are currently used in small satellites were usually designed to handle large separation loads. As a result, they have complex structures, large footprints, and high power consumptions. In this paper, we report a simpler and more compact separation device. A design methodology for the load-shifting SMA actuator (LSSA) used in a device was developed. Four prototypes were fabricated and tested to demonstrate the design concept and the LSSA design methodology. Experiments showed that this separation device has the merits of a quick response time, compact size, and simple structure, which give it potential for small-satellite applications.
Effective Method to Predict Installation of Plunger in a Gas Well
Authors: Luo Shu , Kelkar Mohan
Published: October 2013

Liquid loading is a common problem for most of the mature gas wells. Over years, many methods have been developed to solve this problem. One of the widely used methods is plunger lift, which requires shut-in of the gas well for a period of time. Then, the well is reopened, and it is expected that the natural energy of the well will push the plunger to the surface carrying the liquid with it. Optimization of the plunger lift requires that the well be shut-in for a period of time as short as possible, followed by production of gas for as long as possible. This note examines the requirement for a successful shut-in of a well so that the well can sustain the production for a longer time. The note also discusses the condition under which the well will not sustain the production and the plunger lift will not be effective. The analysis is confirmed with several field examples, which will be shown in this note.
Use of Image-Based Direct Normal Irradiance Forecasts in the Model Predictive Control of a Solar-Thermal Reactor
Authors: Saade Elizabeth , Clough David E. , Weimer Alan W.
Published: October 2013

A model predictive control (MPC) system for a solar-thermal reactor was developed and applied to the solar-thermal steam-gasification of carbon. The controller aims at rejecting the disturbances in solar irradiance, caused by the presence of clouds. Changes in solar irradiance are anticipated using direct normal irradiance (DNI) forecasts generated using images acquired through a Total Sky Imager (TSI). The DNI predictor provides an estimation of the disturbances for the control algorithm, for a time horizon of 1 min. The proposed predictor utilizes information obtained through the analysis of sky images, in combination with current atmospheric measurements, to produce the DNI forecast. The predictions of the disturbances are used, in combination with a dynamic model of the process, to determine the required control moves at every time step. The performance of the proposed DNI predictor-controller scheme was compared to the performance of an equivalent MPC that does not use DNI forecasts in the calculation of the control signals. In addition, the performance of a controller fed with perfect DNI predictions was also evaluated.
Estimation of Global Solar Radiation Using Artificial Neural Networks in Abu Dhabi City, United Arab Emirates
Authors: Al-Shamisi Maitha , Assi Ali , Hejase Hassan
Published: October 2013

The geographical location (Latitude: 24 deg 28′ N and Longitude: 54 deg 22′ E) of Abu Dhabi city in the United Arab Emirates (UAE) favors the development and utilization of solar energy. This paper presents an artificial neural network (ANN) approach for the estimation of monthly mean global solar radiation (GSR) on a horizontal surface in Abu Dhabi. The ANN models are presented and implemented on a 16-yr measured meteorological data set for Abu Dhabi comprising the maximum daily temperature, mean daily wind speed, mean daily sunshine hours, and mean daily relative humidity between 1993 and 2008. The meteorological data between 1993 and 2003 are used for training the ANN and data between 2004 and 2008 are used for testing the estimated values. Multilayer perceptron (MLP) and radial basis function (RBF) are used as ANN learning algorithms. The results attest to the capability of ANN techniques and their ability to produce accurate estimation models.
Integrated Process of Laser-Assisted Machining and Laser Surface Heat Treatment
Authors: Shi Bin , Attia Helmi
Published: October 2013

A process is proposed for integrating the laser-assisted machining (LAM) and laser surface heat treatment (LSHT) in a single operation. Experimental and numerical investigations were carried out. LSHT tests were performed to investigate the effect of the process parameters on the microstructure evolution and hardenability. A methodology and an empirical model for prediction of hardened depth were proposed. A two-dimensional finite element (2D-FE) model was developed to predict the phase transformation during the LAM and LSHT processes. The optimization of the LAM process was also investigated using the developed finite element model.
Experimental Validation of Fretting Fatigue Strength and Fretting Wear Rate at Contact Surface of Turbine-Blade-Shroud Cover
Authors: Asai Kunio , Kudo Takeshi , Yoda Hideo
Published: October 2013

In continuously coupled blade structures, fretting fatigue and wear have to be considered as supposed failure modes at the contact surface of the shroud cover, which is subject to steady contact pressure from centrifugal force and the vibratory load of the blade. We did unique fretting tests that modeled the structure of the shroud cover, where the vibratory load is only carried by the contact friction force, i.e., a type of friction. What was investigated in this study are fretting fatigue strength, wear rate, and friction characteristics, such as friction coefficient and slip-range of 12%-Cr steel blade material. The friction-type tests showed that fretting fatigue strength decreases with the contact pressure and a critical normal contact force exists under which fretting fatigue failure does not occur at any vibratory load. This differs from knowledge obtained through pad-type load carry tests that fretting fatigue strength decreases with the increase of contact pressure and that it almost saturates under a certain contact pressure. Our detailed observation in the friction-type tests clarified that this mechanism was the low contact pressure narrowing the contact area and a resulting high stress concentration at a local area. The fretting wear rate was explained by the dissipated energy rate per cycle obtained from the measured hysteresis loop between the relative slip range and the tangential contact force. It was found that the fretting wear rate is smaller than the wear rate obtained by one-way sliding tests, and the former is much smaller than the latter as the dissipated energy decreases. Finally, to prevent fretting fatigue and wear, we propose an evaluation design chart of the contact surface of the shroud cover based on our friction-type fretting tests.
Structural Integrity Evaluation of Spent Fuel Storage Racks and Support Frame for a Research Reactor
Authors: Oh Jinho , Ryu Jeong-Soo , Kim Young-Ki
Published: October 2013

The objective of this study is to design the spent fuel storage rack (SFSR) and their support frame as well as to evaluate the structural integrity of those during and after the seismic events. The main function of these racks is to store and protect the irradiated fuel assemblies generated during the operation of the research reactor. Their support frame is used for maintaining the structural stability of these racks. The SFSRs and their support frame are classified into safety class NNS and seismic category I according with ANSI 51.1 [1] and Regulatory Guide 1.29 [2]. The design of those has been performed according to the guideline of Regulatory Guide 1.13 [3] and IAEA safety standards DS 350 [4]. Specially, the pitch among storage cells should be decided from the criticality calculation with all postulated assumptions according to the NUREG 1537 [5] (Effective Neutron Multiplication Factor, keff < 0.9), conservatively.

These racks are installed in their support frame having free standing type boundary conditions in the pool. Since the dynamic behavior of structures can be significantly affected by the water, the hydrodynamic effect is considered by using added mass. All materials of submerged racks and their support frame are made of austenitic stainless steel to prevent the corrosion. To evaluate the structural integrity of these racks and their support frame, the response spectrum analysis (RSA) and response time history analysis have been performed under the seismic loads of OBE (Operating Basis Earthquake) and SSE (Safe Shutdown Earthquake) by using ANSYS software. In addition, the possibility of impact between the side wall of the pool and the support frame is investigated by using a nonlinear time history analysis considering the structural nonlinearity such as the contact and the friction problem.

The analysis results show that the maximum stress values of these racks and their support frame under the seismic loads are within the specified code limits. Since the sliding distance calculated from the nonlinear time history analysis is less than the gap, the impact does not occur. It is confirmed that those cannot be overturned but slide under an SSE event. Therefore, any damage on the structural integrity is not expected when those are installed and utilized in the pool.
Thermal-Hydraulic Character Effect Factors Analysis for Passive Residual Heat Removal System of Sodium-Cooled Fast Reactor
Authors: Sun Xiaolong , Peng Minjun , Xia Genglei
Published: October 2013

A theoretical investigation was performed on the passive residual heat removal system (PRHRs) of China Experimental Fast Reactor (CEFR). The system contained two air heat exchangers, two independent heat exchangers and several pipes. By means of JTOPMERET code developed by GSE, the thermodynamic model of the system had been built. Based on the model, transient characteristics of the PRHRs have been discussed in detail. Through the calculation analysis, it is then indicated that the capacity of removing residual heat was affected by some factors. The faster speed of air in the air heat exchanger, the higher temperature and the larger heat transfer area of the air heat exchanger are favorable to the PRHRs. At the same time, the calculated parameters variation trends are reasonable according to the Experimental data from CEFR.
Corium and Debris Coolability Studies Performed in the Severe Accident Research Network of Excellence (SARNET2)
Authors: Miassoedov Alexei , Tromm Th. Walter , Birchley Jonathan , Fichot Florian , Ma Weimin , Pohlner Georg , Matejovic Peter
Published: October 2013

The motivation of the work performed within the work package “Corium and Debris Coolability” of the Severe Accident Research Network of Excellence (SARNET) is to reduce or possibly solve the remaining uncertainties on the efficiency of cooling reactor core structures and materials during severe accidents, either in the core, in the vessel lower head or in the reactor cavity, so as to limit the progression of the accident. This can be achieved either by ensuring corium retention within the reactor pressure vessel or at least by limiting the corium progression and the rate of corium release into the cavity. These issues are to be covered within the scope of accident management for existing reactors and within the scope of design and safety evaluation of future reactors. The specific objectives are to create and enhance the database on debris formation, debris coolability and corium behavior in the lower head, to develop and validate the models and computer codes for simulation of in-vessel debris bed and melt pool behavior, to perform reactor scale analysis for in-vessel corium coolability and to assess the influence of severe accident management measures on in-vessel coolability. The work being performed within this work package comprises experimental and modeling activities with strong cross coupling between the tasks. Substantial knowledge and understanding of governing phenomena concerning coolability of intact rod-like reactor core geometry was obtained in previous projects. Hence the main thrust of experimental and modeling efforts concentrates mainly on the study of formation and cooling of debris beds in order to demonstrate effective cooling modes, cooling rates and coolability limits. Modeling efforts have been aimed at assessing and validating the models in system-level and detailed codes for core degradation, oxidation and debris behavior. The paper describes the work performed up to now and summarizes the main results achieved so far.
Investigations on Slug Flow in a Horizontal Pipe Using Stereoscopic Particle Image Velocimetry and CFD Simulation With Volume of Fluid Method
Authors: Czapp Marek , Utschick Matthias , Rutzmoser Johannes , Sattelmayer Thomas
Published: October 2013

Investigations on gas-liquid flows in horizontal pipes are of immanent importance for Reactor Safety Research. In case of a breakage of the main cooling circuit of a Pressurized Water Reactor (PWR), the pressure losses of the gas-liquid flow significantly govern the loss of coolant rate. The flow regime is largely determined by liquid and gas superficial velocities and contains slug flow that causes high-pressure pulsations to the infrastructure of the main cooling circuit.

Experimental and numerical investigations on adiabatic slug flow of a water-air system were carried out in a horizontal pipe of about 10 m length and 54 mm diameter at atmospheric pressure and room temperature. Stereoscopic high-speed Particle Image Velocimetry in combination with Laser Induced Fluorescence was successfully applied on round pipe geometry to determine instantaneous three-dimensional water velocity fields of slug flows.

After grid independence studies, numerical simulations were run with the open-source CFD program OpenFOAM. The solver uses the VOF method (Volume of Fluid) with phase-fraction interface capturing approach based on interface compression. It provides mesh refinement at the interfacial area to improve resolution of the interface between the two phases. Furthermore, standard k-ε turbulence model was applied in an unsteady Reynolds averaged Navier Stokes (URANS) model to resolve self-induced slug formation.

The aim of this work is to present the feasibility of both relatively novel possibilities of determining two-phase slug flows in pipes. Experimental and numerical results allow the comparison of the slug initiation and expansion process with respect to their axial velocities and cross-sectional void fractions.
Developing Heat-Transfer Correlations for Supercritical CO2 Flowing in Vertical Bare Tubes
Authors: Gupta Sahil , McGillivray Donald , Surendran Prabu , Trevani Liliana , Pioro Igor
Published: October 2013

This paper presents an analysis of three new heat-transfer correlations developed for supercritical carbon dioxide (CO2) flowing in vertical bare tubes. A large set of experimental data was obtained at Chalk River Laboratories (CRL) AECL. Heat-transfer tests were performed in upward flow of CO2 inside 8-mm ID vertical Inconel-600 tube with a 2.208-m heated length. Data points were collected at outlet pressures ranging from 7.4 to 8.8 MPa, mass fluxes from 900 to 3000 kg/m2s, inlet fluid temperatures from 20 to 40°C, and heat fluxes from 15 to 615 kW/m2; and for several combinations of wall and bulk-fluid temperatures that were below, at, or above the pseudocritical temperature.

The objective of the present experimental research is to obtain reference dataset on heat transfer in supercritical CO2 and improve our fundamental knowledge of the heat-transfer processes and handling of supercritical fluids. In general, heat-transfer process to a supercritical fluid is difficult to model, especially, when a fluid passes through the pseudocritical region, as there are very rapid variations in thermophysical properties of the fluid. Thus, it is important to investigate supercritical-fluid behaviour within these conditions.

In general, supercritical carbon dioxide was and is used as a modelling fluid instead of supercritical water due to its lower critical parameters compared to those of water. Also, supercritical carbon dioxide is proposed to be used as a working fluid in the Brayton gas-turbine cycle as a secondary power cycle for some of the Generation-IV nuclear-reactor concepts such as a Sodium-cooled Fast Reactor (SFR), Lead-cooled Fast Reactor (LFR) and Molten-Salt-cooled Reactor (MSR). In addition, supercritical carbon dioxide was proposed to be used in advanced air-conditioning and geothermal systems.

Previous studies have shown that existing correlations deviate significantly from experimental Heat Transfer Coefficient (HTC) values, especially, within the pseudocritical range. Moreover, the majority of correlations were mainly developed for supercritical water, and our latest results indicate that they cannot be directly applied to supercritical CO2 with the same accuracy as for water.

Therefore, new empirical correlations to predict HTC values were developed based on the supercritical CO2 dataset. These correlations calculate HTC values with an accuracy of ±30% (wall temperatures with accuracy of ±20%) for the analyzed dataset.