bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomechanical Evaluation of a Novel Subcuticular Skin Stapling Device for Use in Equine Abdominal Surgeries
Authors: Biedrzycki Adam , Markel Mark D. , Brounts Sabrina H.
Published: July 2014

Objective

To compare thein vitrobiomechanical properties of a novel subcuticular stapling device to current methods of abdominal skin closure for equine abdominal surgery.

Study Design

In vitrorandomized, matched design.

Sample Population

Equine ventral median abdominal skin specimens (n = 24 horses).

Methods

Subcuticular absorbable staples (SAS), metallic staples (MS), polyglyconate suture (PG), and nylon monofilament (NYL) were applied to longitudinally transected portions of equine ventral midline skin. Loads that resulted in an initial failure point and the ultimate failure load and mechanism were recorded.

Results

Mean ± SD loads at initial failure for PG (86 N ± 64 N), NYL (81 N ± 142 N), and SAS (70 N ± 20 N) were not significantly different from each other. PG and SAS were significantly higher than MS (43 N ± 17 N;P < .05). Ultimate failure load for PG (563 N ± 157 N) and NYL (558 N ± 162 N) were significantly higher than either MS (175 N ± 44 N) or SAS (96 N ± 20N;P < .001). For the suture groups, nearly all failures occurred because of skin pull through whereas all SAS staples failed because of staple fracture. Failure patterns were mixed for MS.

Conclusions

SAS had the lowest ultimate failure load; however, other measured variables identified characteristics of SAS that may be clinically beneficial.
Intracardiac Thrombosis in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy
Authors: WU LINGMIN , YAO YAN , CHEN GANG , FAN XIAOHAN , ZHENG LIHUI , DING LIGANG , ZHANG SHU
Published: July 2014

Intracardiac Thrombosis in ARVC

Background

Intracardiac thrombus has been reported in anecdotal cases of arrhythmogenic right ventricular cardiomyopathy (ARVC). This prospective study aimed to determine the prevalence, risk factors, and prognosis of intracardiac thrombosis in patients with ARVC.

Methods

From February 2004 to August 2013, transthoracic echocardiograms and magnetic resonance imagings were performed in 193 patients with ARVC. The prevalence, risk factors, and prognosis of intracardiac thrombosis were investigated.

Results

Ten intracardiac thrombi were identified in 8 patients (4.1%), the majority (7/10) of which were found in the right ventricular apex. Multivariate analysis showed that female gender and left ventricular dysfunction were independently associated with increased risk for thrombosis in ARVC. All thrombi were eliminated in 3 weeks after anticoagulation therapy without any complication. During a median follow‐up time of 38 months (range 2 to 128), no thromboembolism event or sudden death was observed in patients under anticoagulation therapy; however, in patients without anticoagulation therapy, definite pulmonary thromboembolism occurred in 1 and sudden death due to suspected pulmonary thromboembolism was observed in another.

Conclusion

Intracardiac thrombosis may occur in certain patients with ARVC. Female gender and left ventricular dysfunction appeared to be associated with increased risk for thrombosis. Early screening and effective anticoagulation therapy may improve the prognosis.
Diet specialization in an extreme omnivore: nutritional regulation in glucose‐averse German cockroaches
Authors: Shik J. Z. , Schal C. , Silverman J.
Published: July 2014

Organisms have diverse adaptations for balancing dietary nutrients, but often face trade‐offs between ingesting nutrients and toxins in food. While extremely omnivorous cockroaches would seem excluded from such dietary trade‐offs, German cockroaches (Blattella germanica) in multiple populations have rapidly evolved a unique dietary specialization – an aversion to glucose, the phagostimulant in toxic baits used for pest control. We used factorial feeding experiments within the geometric framework to test whether glucose‐averse (GA) cockroaches with limited access to this critical metabolic fuel have compensatory behavioural and physiological strategies for meeting nutritional requirements. GA cockroaches had severely constrained intake, fat and N mass, and performance on glucose‐based diets relative to wild‐type (WT) cockroaches and did not appear to exhibit digestive strategies for retaining undereaten nutrients. However, a GA × WT ‘hybrid’ had lower glucose aversion than GA and greater access to macronutrients within glucose‐based diets – while still having lower intake and survival than WT. Given these intermediate foraging constraints, hybrids may be a reservoir for this maladaptive trait in the absence of positive selection and may account for the rapid evolution of this trait following bait application.
Smolting in coastal cutthroat trout Onchorhynchus clarkii clarkii
Authors: Zydlewski J. , Zydlewski G. , Kennedy B. , Gale W.
Published: July 2014

Gill Na+, K+‐ATPase activity, condition factor and seawater (SW) challenges were used to assess the development of smolt characteristics in a cohort of hatchery coastal cutthroat trout Oncorhynchus clarkii clarkii from the Cowlitz River in Washington State, U.S.A. Gill Na+, K+‐ATPase activity increased slightly in the spring, coinciding with an increase in hypo‐osmoregulatory ability. These changes were of lesser magnitude than are observed in other salmonine species. Even at the peak of tolerance, these fish exhibited notable osmotic perturbations in full strength SW. Condition factor in these hatchery fish declined steadily through the spring. Wild captured migrants from four tributaries of the Columbia River had moderately elevated gill Na+, K+‐ATPase activity, consistent with smolt development and with greater enzyme activity than autumn captured juveniles from one of the tributaries, Abernathy Creek. Migrant fish also had reduced condition factor. General linear models of 7 years of data from Abernathy Creek suggest that yearly variation, advancing photoperiod (as ordinal date) and fish size (fork length) were significant factors for predicting gill Na+, K+‐ATPase activity in these wild fish. Both yearly variation and temperature were significant factors for predicting condition factor. These results suggest that coastal O. c. clarkii exhibit weakly developed characteristics of smolting. These changes are influenced by environmental conditions with great individual variation. The data suggest great physiological plasticity consistent with the variable life‐history tactics observed in this species.
Home range and social analyses in a mouth brooding frog: testing the coexistence of paternal care and male territoriality
Authors: Valenzuela‐Sánchez A. , Harding G. , Cunningham A. A. , Chirgwin C. , Soto‐Azat C.
Published: July 2014

A link between paternal care and territoriality has been described in several anuran species. The southern Darwin's frog (Rhinoderma darwinii) has developed a highly specialized form of paternal care known as neomelia, in which males ingest developing embryos and transport them in their vocal sacs until metamorphosis is completed. Based on the main components of territoriality described in amphibians: site fidelity, resource limitation and defence (e.g. of oviposition sites and egg clutches), we hypothesized that R. darwinii males exhibit territoriality. To investigate this, we used a multi‐method approach that involved estimating home range and movements, performing social network analyses and monitoring potential egg attendance. Forty‐five individual frogs and three egg clutches were monitored in a population from southern Chile between December 2010 and February 2011. Site fidelity was found across all groups (juveniles, females, non‐brooding males and brooding males) based on small movements between captures (mean ±1 se; 0.96 ± 0.11 m) and small net displacement (2.95 ± 0.55 m). Home ranges were small (1.82 ± 0.54 m; range: 0.1–16 m2) and did not differ significantly among groups. We did not find evidence of male territoriality, instead male frogs exhibited high home range overlapping and intra‐group association. No frogs of either sex were ever seen attending eggs. This evidence supports Wells' suggestion; territoriality in anuran species with parental care should be expected only if males defend oviposition sites. Conversely, females did not exhibit home range overlapping and showed evidence of very low intra‐group association. This study has thrown up a range of additional questions with regard to temporal segregation between non‐brooding males, the roles of male and female calls during reproduction, potential female territoriality and what kind of signals triggers egg ingestion by males.
Are fern stomatal responses to different stimuli coordinated? Testing responses to light, vapor pressure deficit, and CO2 for diverse species grown under contrasting irradiances
Authors: Creese Chris , Oberbauer Steve , Rundel Phil , Sack Lawren
Published: July 2014

The stomatal behavior of ferns provides an excellent system for disentangling responses to different environmental signals, which balance carbon gain against water loss.

Here, we measured responses of stomatal conductance (gs) to irradiance, CO2, and vapor pressure deficit (VPD) for 13 phylogenetically diverse species native to open and shaded habitats, grown under high‐ and low‐irradiance treatments. We tested two main hypotheses: that plants adapted and grown in high‐irradiance environments would have greater responsiveness to all stimuli given higher flux rates; and that species' responsiveness to different factors would be correlated because of the relative simplicity of fern stomatal control.

We found that species with higher light‐saturated gs had larger responses, and that plants grown under high irradiance were more responsive to all stimuli. Open habitat species showed greater responsiveness to irradiance and CO2, but lower responsiveness to VPD; a case of plasticity and adaptation tending in different directions. Responses of gs to irradiance and VPD were positively correlated across species, but CO2 responses were independent and highly variable.

The novel finding of correlations among stomatal responses to different stimuli suggests coordination of hydraulic and photosynthetic signaling networks modulating fern stomatal responses, which show distinct optimization at growth and evolutionary time‐scales.
Mesophyll photosynthesis and guard cell metabolism impacts on stomatal behaviour
Authors: Lawson Tracy , Simkin Andrew J. , Kelly Gilor , Granot David
Published: July 2014

Stomata control gaseous fluxes between the internal leaf air spaces and the external atmosphere. Guard cells determine stomatal aperture and must operate to ensure an appropriate balance betweenCO2uptake for photosynthesis (A) and water loss, and ultimately plant water use efficiency (WUE). A strong correlation betweenAand stomatal conductance (gs) is well documented and often observed, but the underlying mechanisms, possible signals and metabolites that promote this relationship are currently unknown. In this review we evaluate the current literature on mesophyll‐driven signals that may coordinate stomatal behaviour with mesophyll carbon assimilation. We explore a possible role of various metabolites including sucrose and malate (from several potential sources; including guard cell photosynthesis) and new evidence that improvements inWUEhave been made by manipulating sucrose metabolism within the guard cells. Finally we discuss the new tools and techniques available for potentially manipulating cell‐specific metabolism, including guard and mesophyll cells, in order to elucidate mesophyll‐derived signals that coordinate mesophyllCO2demands with stomatal behaviour, in order to provide a mechanistic understanding of these processes as this may identify potential targets for manipulations in order to improve plantWUEand crop yield.

ContentsSummary1064I.Introduction1064II.Coordination between mesophyll and stomata1066III.The mesophyll signal1066IV.Arguments against a mesophyll‐driven signal other thanCi1068V.Guard cell osmoregulation and evidence for a role of sucrose1069VI.Degradation of starch1070VII.Guard cell photosynthetic production of Suc1070VIII.Guard cell Suc imported from the mesophyll1070IX.Sugar sensing and metabolism1071X.The importance of malate as a mesophyll‐driven signal1072XI.Role of aquaporins1074XII.Guard cell manipulation and possible future directions1074Acknowledgements1076References1076
Herbivore‐mediated material fluxes in a northern deciduous forest under elevated carbon dioxide and ozone concentrations
Authors: Meehan Timothy D. , Couture John J. , Bennett Alison E. , Lindroth Richard L.
Published: July 2014

Anthropogenic changes in atmospheric carbon dioxide (CO2) and ozone (O3) are known to alter tree physiology and growth, but the cascading effects on herbivore communities and herbivore‐mediated nutrient cycling are poorly understood.

We sampled herbivore frass, herbivore‐mediated greenfall, and leaf‐litter deposition in temperate forest stands under elevated CO2 (c. 560 ppm) and O3 (c. 1.5× ambient), analyzed substrate chemical composition, and compared the quality and quantity of fluxes under multiple atmospheric treatments.

Leaf‐chewing herbivores fluxed 6.2 g m−2 yr−1 of frass and greenfall from the canopy to the forest floor, with a carbon : nitrogen (C : N) ratio 32% lower than that of leaf litter. Herbivore fluxes of dry matter, C, condensed tannins, and N increased under elevated CO2 (35, 32, 63 and 39%, respectively), while fluxes of N decreased (18%) under elevated O3. Herbivore‐mediated dry matter inputs scaled across atmospheric treatments as a constant proportion of leaf‐litter inputs.

Increased fluxes under elevated CO2 were consistent with increased herbivore consumption and abundance, and with increased plant growth and soil respiration, previously reported for this experimental site. Results suggest that insect herbivory will reinforce other factors, such as photosynthetic rate and fine‐root production, impacting C sequestration by forests in future environments.
Drought effect on plant nitrogen and phosphorus: a meta‐analysis
Authors: He Mingzhu , Dijkstra Feike A.
Published: July 2014

Climate change scenarios forecast increased aridity in large areas worldwide with potentially important effects on nutrient availability and plant growth. Plant nitrogen and phosphorus concentrations (plant [N] and [P]) have been used to assess nutrient limitation, but a comprehensive understanding of drought stress on plant [N] and [P] remains elusive.

We conducted a meta‐analysis to examine responses of plant [N] and [P] to drought manipulation treatments and duration of drought stress.

Drought stress showed negative effects on plant [N] (−3.73%) and plant [P] (−9.18%), and a positive effect on plant N : P (+ 6.98%). Drought stress had stronger negative effects on plant [N] and [P] in the short term (< 90 d) than in the long term (> 90 d). Drought treatments that included drying–rewetting cycles showed no effect on plant [N] and [P], while constant, prolonged, or intermittent drought stress had a negative effect on plant [P].

Our results suggest that negative effects on plant [N] and [P] are alleviated with extended duration of drought treatments and with drying–rewetting cycles. Availability of water, rather than of N and P, may be the main driver for reduced plant growth with increased long‐term drought stress.
FgKin1 kinase localizes to the septal pore and plays a role in hyphal growth, ascospore germination, pathogenesis, and localization of Tub1 beta‐tubulins in Fusarium graminearum
Authors: Luo Yongping , Zhang Hongchang , Qi Linlu , Zhang Shijie , Zhou Xiaoying , Zhang Yimei , Xu Jin‐Rong
Published: July 2014

The Kin1/Par‐1/MARK kinases regulate various cellular processes in eukaryotic organisms. Kin1 orthologs are well conserved in fungal pathogens but none of them have been functionally characterized. Here, we show that KIN1 is important for pathogenesis and growth in two phytopathogenic fungi and that FgKin1 regulates ascospore germination and the localization of Tub1 β‐tubulins in Fusarium graminearum.

The Fgkin1 mutant and putative FgKIN1S172A kinase dead (nonactivatable) transformants were characterized for defects in plant infection, sexual and asexual reproduction, and stress responses. The localization of FgKin1 and two β‐tubulins were examined in the wild‐type and mutant backgrounds.

Deletion of FgKIN1 resulted in reduced virulence and defects in ascospore germination and release. FgKin1 localized to the center of septal pores. FgKIN1 deletion had no effect on Tub2 microtubules but disrupted Tub1 localization. In the mutant, Tub1 appeared to be enriched in the nucleolus. In Magnaporthe oryzae, MoKin1 has similar functions in growth and infection and it also localizes to septal pores. The S172A mutation had no effect on the localization and function of FgKIN1 during sexual reproduction.

These results indicate that FgKIN1 has kinase‐dependent and independent functions and it specifically regulates Tub1 β‐tubulins. FgKin1 plays a critical role in ascospore discharge, germination, and plant infection.
Emergence of apospory and bypass of meiosis via apomixis after sexual hybridisation and polyploidisation
Authors: Hojsgaard Diego , Greilhuber Johann , Pellino Marco , Paun Ovidiu , Sharbel Timothy F. , Hörandl Elvira
Published: July 2014

Hybridisation and polyploidy are major forces contributing to plant speciation. Homoploid (2x) and heteroploid (3x) hybrids, however, represent critical stages for evolution due to disturbed meiosis and reduced fertility. Apomixis – asexual reproduction via seeds – can overcome hybrid sterility, but requires several concerted alterations of developmental pathways to result in functional seed formation.

Here, we analyse the reproductive behaviours of homo‐ and heteroploid synthetic hybrids from crosses between sexual diploid and tetraploidRanunculus auricomusspecies to test the hypothesis that developmental asynchrony in hybrids triggers the shift to apomictic reproduction.

Evaluation of male and female gametophyte development, viability and functionality of gametes shows developmental asynchrony, whereas seed set and germinability indicate reduced fitness in synthetic hybrids compared to sexual parents. We present the first experimental evidence for spontaneous apospory in most hybrids as an alternative pathway to meiosis, and the appearance of functional apomictic seeds in triploids. Bypassing meiosis permits these triploid genotypes to form viable seed and new polyploid progeny.

Asynchronous development causes reduced sexual seed set and emergence of apospory in syntheticRanunculushybrids. Apomixis is functional in triploids and associated with drastic meiotic abnormalities. Selection acts to stabilise developmental patterns and to tolerate endosperm dosage balance shifts which facilitates successful seed set and establishment of apomictic lineages.
Implications of 21st century science for nursing care: interpretations and issues
Authors: Yeo Michael T.
Published: July 2014

The organizing theme for this special volume raises a momentous question: What are the implications of 21st century science for nursing care? The two terms the question relates – 21st century science and nursing care – are each of central importance for nursing and in philosophical enquiry about nursing as a practice, profession, or institution. These key terms are also highly charged and open to interpretation, as is the relationship of implication between them. Different interpretations or assumptions will steer the search for an answer in quite different directions.

Putting the expectation of an answer in abeyance, this paper probes the question precisely in its openness to interpretation and contestation. In elaborating different ways in which the main terms of the question can be taken, and analysing how different interpretations of or assumptions about them lead to different responses, the paper delineates crucial issues and divisions in nursing and commentary about nursing today.
Activities and Health Status of Dispatched Public Health Nurses after the Great East Japan Earthquake
Authors: Yokoyama Yoshie , Hirano Kayoko , Sato Mari , Abe Akiko , Uebayashi Mihoko , Kishi Emiko , Sato Mutsuko , Kuroda Yuuko , Nakaita Ikumi , Fukushima Fujio
Published: July 2014

Objective

This study aimed to elucidate the actual activities conducted by public health nurses during their dispatch and their health status during and after dispatch to the three prefectures most severely affected by the Great East Japan Earthquake.

Sample

A survey request was sent to a total of 2,237 facilities. Of these, 778 facilities returned questionnaires from dispatched public health nurses.

Results

The participants of this study were 1,570 dispatched health nurses who participated in activities mostly at evacuation centers, followed by evacuees’ homes. After dispatch, an earlier postdisaster phase at the start of dispatch was independently associated with poor subjective well‐being, low mood, worsened sleep state, and intense fatigue. Work hours per day were associated with poor subjective well‐being and intense fatigue after dispatch.

Conclusion

Results suggest that the factor that most strongly affected the postdispatch health of the nurses was the phase that they began their dispatch.
Measurement of the uniaxial mechanical properties of rat skin using different stress–strain definitions
Authors: Karimi A. , Navidbakhsh M.
Published: July 2014

Background/Purpose

The mechanical properties of skin tissue may vary according to the anatomical locations of a body. There are different stress–strain definitions to measure the mechanical properties of skin tissue. However, there is no agreement as to which stress–strain definition should be implemented to measure the mechanical properties of skin at different anatomical locations. Three stress definitions (second Piola–Kichhoff stress, engineering stress, and true stress) and four strain definitions (Almansi–Hamel strain, Green‐St. Venant strain, engineering strain, and true strain) are employed to determine the mechanical properties of skin tissue at back and abdomen locations of a rat body.

Methods

The back and abdomen skins of eight rats are excised and subjected to a series of tensile tests. The elastic modulus, maximum stress, and strain of skin tissues are measured using three stress definitions and four strain definitions.

Results

The results show that the effect of varying the stress definition on the maximum stress measurements of the back skin is significant but not when calculating the elastic modulus and maximum strain. No significant effects are observed on the elastic modulus, maximum stress, and strain measurements of abdomen skin by varying the stress definition. In the true stress–strain diagram, the maximum stress (20%), and elastic modulus (35%) of back skin are significantly higher than that of abdomen skin.

Conclusion

The true stress–strain definition is favored to measure the mechanical properties of skin tissue since it gives more accurate measurements of the skin's response using the instantaneous values.
Follow‐up of solar lentigo depigmentation with a retinaldehyde‐based cream by clinical evaluation and calibrated colour imaging
Authors: Questel E. , Durbise E. , Bardy A.‐L. , Schmitt A.‐M. , Josse G.
Published: July 2014

Background and Objective

To assess an objective method evaluating the effects of a retinaldehyde‐based cream (RA‐cream) on solar lentigines; 29 women randomly applied RA‐cream on lentigines of one hand and a control cream on the other, once daily for 3 months.

Methods

A specific method enabling a reliable visualisation of the lesions was proposed, using high‐magnification colour‐calibrated camera imaging. Assessment was performed using clinical evaluation by Physician Global Assessment score and image analysis. Luminance determination on the numeric images was performed either on the basis of 5 independent expert's consensus borders or probability map analysis via an algorithm automatically detecting the pigmented area.

Results

Both image analysis methods showed a similar lightening of ΔL* = 2 after a 3‐month treatment by RA‐cream, in agreement with single‐blind clinical evaluation.

Conclusion

High‐magnification colour‐calibrated camera imaging combined with probability map analysis is a fast and precise method to follow lentigo depigmentation.
The RAB5‐GEF Function of RIN1 Regulates Multiple Steps During Listeria monocytogenes Infection
Authors: Balaji Kavitha , French Christopher T. , Miller Jeff F. , Colicelli John
Published: July 2014

Listeria monocytogenes is a food‐borne pathogenic bacterium that invades intestinal epithelial cells through a phagocytic pathway that relies on the activation of host cell RAB5 GTPases. Listeria monocytogenes must subsequently inhibit RAB5, however, in order to escape lysosome‐mediated destruction. Relatively little is known about upstream RAB5 regulators during L. monocytogenes entry and phagosome escape processes in epithelial cells. Here we identify RIN1, a RAS effector and RAB5‐directed guanine nucleotide exchange factor (GEF), as a host cell factor in L. monocytogenes infection. RIN1 is rapidly engaged following L. monocytogenes infection and is required for efficient invasion of intestinal epithelial cells. RIN1‐mediated RAB5 activation later facilitates the fusion of phagosomes with lysosomes, promoting clearance of bacteria from the host cell. These results suggest that RIN1 is a host cell regulator that performs counterbalancing functions during early and late stages of L. monocytogenes infection, ultimately favoring pathogen clearance.
Cost‐effectiveness of red blood cell transfusion vs. non‐intervention in women with acute anaemia after postpartum haemorrhage
Authors: Prick B. W. , Duvekot J. J. , van der Moer P. E. , van Gemund N. , van der Salm P. C. M. , Jansen A. J. G. , van Rhenen D. J. , Mol B. W. , Uyl‐de Groot C. A.
Published: July 2014

Background

Red blood cell (RBC) transfusion is frequently used to treat women with acute anaemia after postpartum haemorrhage. We aimed to assess the economic consequences of red blood cell transfusion compared to non‐intervention in these women.

Methods

A trial‐based cost‐effectiveness analysis was performed alongside the Well‐Being of Obstetric patients on Minimal Blood transfusions (WOMB) trial. Women with acute anaemia [Hb 4·8–7·9 g/dl (3·0–4·9 mm)] after postpartum haemorrhage, without severe anaemic symptoms, were randomly allocated to RBC transfusion or non‐intervention. Primary outcome of the trial was physical fatigue (Multidimensional Fatigue Inventory, scale 4–20; 20 represents maximal fatigue). Total costs per arm were calculated using a hospital perspective with a 6 weeks time horizon.

Results

Per woman, mean costs in the RBC transfusion arm (n = 258) were €1957 compared to €1708 in the non‐intervention arm (n = 261; P = 0·024). The 13% difference in costs between study arms predominantly originated from costs of RBC units, as costs of RBC units were six times higher in the RBC transfusion arm. RBC transfusion led to a small improvement in physical fatigue of 0·58 points per day; thus, the costs to improve the physical fatigue score with one point would be €431.

Conclusion

In women with acute anaemia after postpartum haemorrhage (PPH), RBC transfusion is on average €249 more expensive per woman than non‐intervention, with only a small gain in HRQoL after RBC transfusion. Taking both clinical and economic consequences into account, implementation of a non‐intervention policy seems justified.
Incidence and risk factors of poor mobilization in adult autologous peripheral blood stem cell transplantation: a single‐centre experience
Authors: Lee K. H. , Jung S. K. , Kim S. J. , Jang J. H. , Kim K. , Kim W. S. , Jung C. W. , Kim D. W. , Kang E. S.
Published: July 2014

Background and Objectives

Collection of sufficient CD34+ cells for autologous peripheral blood stem cell (PBSC) transplantation is frequently failed in patients with lymphoma or multiple myeloma (MM). We investigated the incidence and the predictive factors for poor mobilization.

Materials and Methods

A total of 205 adult patients (101 lymphoma and 104 MM) were retrospectively included for identifying the incidence of mobilization failure and the predictive factors for poor mobilization in conventional G‐CSF‐based mobilization regimen. Another 17 patients who used plerixafor for mobilization were included.

Results

Overall, 14·1% of patients (21·8% of patients with lymphoma, 6·7% of patients with MM) were poor mobilizers. Univariate analysis and multivariate analysis revealed an interval from G‐CSF administration to PBSC collection exceeding 10 days and peripheral blood mononuclear cells count on the first day of collection were predictive factors for poor mobilization in lymphoma, but not in MM. Among plerixafor‐treated patient group, 9 of 11 poor mobilizers who received second‐cycle plerixafor mobilization were able to collect higher number of CD34+ cells than that of CD34+ cells during the G‐CSF‐based first mobilization. All patients who had received initial plerixafor mobilization reached 2·0 × 106 CD34+ cells/kg during the four leukaphereses.

Conclusion

In conventional G‐CSF‐based mobilization, early PBSC collection after G‐CSF administration might enhance CD34+ cell yield. A combination of a new mobilizing agent, plerixafor, would be helpful to harvest sufficient number of CD34+ cells for successful transplantation outcome while reducing the effort of collection procedures in poor mobilizers.
Flammability Limits of Low BTU Gases: Computations in a Perfectly Stirred Reactor and Experiments
Authors: Hermann Fredrik , Ruck Thomas , Klingmann Jens , Mauss Fabian
Published: July 2014

The demand for gas turbines suitable for Low Btu gases is increasing worldwide. This paper presents a theoretical and experimental investigation of the flammability limits of Low Btu gases for gas turbine applications. Most modern gas turbines utilize premixed combustion, making it important to know at which fuel-air ratio the flame extinguishes. The flammability limit for a gaseous fuel is a property, which is coupled to both thermodynamic quantities and the shape of the combustion chamber. Consequently, this property is characteristic for each combustor and for each fuel.

The experiments were made in an atmospheric pressure premixed combustor at Alstom Power Technology Ltd. Switzerland, adapted for Low Btu gaseous fuels. Five different residual gases from chemical factories were investigated. The gases consisted of methane, carbon monoxide, hydrogen and nitrogen, with lower heating values about 2-3.5 MJ/kg for all examined gases (Table 1).

A steady state Perfectly Stirred Reactor (PSR) was used as a model for the primary combustion zone. The reactions were modeled by a detailed mechanism for methane with 61 species and 667 reactions, developed by Warnatz [1]. The PSR calculations were done by decreasing the residence time until the combustion in the PSR extinguished. These calculations were repeated for different equivalence ratios to obtain the relation between the residence time and the limit of flammability.

The calculations showed a relationship between the residence time in the PSR and the extinction point. It was found that the computed values of the flammability limits, or more correctly called stability limits, qualitatively follow the experimental results. However, since the computational results are strongly dependent on the residence time, a comparison with the experiments must include the residence time of the real burner, which is difficult to define.
Influence of Ambient Air Pressure on Pressure-Swirl Atomizer Spray Characteristics
Authors: Jasuja Arvind K. , Lefebvre Arthur H.
Published: July 2014

A single-component PDPA is used to evaluate the spray characteristics of a simplex pressure-swirl atomizer when operating at high liquid flow rates and elevated ambient air pressures. Attention is focused on the effects of air pressure on mean drop size, drop-size distribution, mean velocity, volume flux, and number density. Using a constant flow rate of 75 g/s, measurements are carried out along the spray radii at a fixed distance downstream from the atomizer face of 50 mm. The air pressures of 1, 8, and 12 bars chosen for these tests correspond to air densities of 1.2, 9.6, and 14.4 kg/m3. The purpose of the investigation is to supplement the existing body of information on pressure-swirl spray characteristics, most of which were obtained at normal atmospheric ambient pressures, with new data that correspond more closely to the conditions prevailing in the primary combustion zones of modern gas turbines. The results obtained are explained mainly in terms of the influence of air pressure on spray structure, in particular spray cone angle and Weber number.
Flashback in Lean Prevaporized Premixed Combustion: Non-Swirling Turbulent Pipe Flow Study
Authors: Schäfer Olaf , Koch R. , Wittig S.
Published: July 2014

A fundamental study has been performed on the upstream flame propagation of a turbulent kerosene flame, stabilized in a confined stagnation flow at atmospheric pressure. Besides temperature and equivalence ratio, mixture properties and fluid dynamic parameters have been varied. The flashback phenomenon is discussed in terms of critical mean velocities and additionally based on detailed LDV data at the outlet of the premixing duct.

The largest critical velocities uc for flashback are found for the “perfectly” premixed case and equivalence ratios close to stoichiometric, which is in accordance with the theory on laminar flame propagation. In the case of a homogeneous mixture, flashback is determined by the velocity distribution at the outlet of the premixing section. In the undisturbed pipe flow the flame propagates through the wall boundary layer. The data for this case are compared with the theory of side-wall quenching in terms of a critical Peclet number and critical velocity gradients at the wall. Both are deduced from the experimental data. Reducing the velocity on the axis forces the flame to propagate through the center at a velocity predicted by correlations on turbulent flame velocity.
Characterization of Confined Swirl Flows Using Large Eddy Simulations
Authors: Schlüter Jörg , Schönfeld Thilo , Poinsot Thierry , Krebs Werner , Hoffmann Stefan
Published: July 2014

Since the flame of high intense low NOx gas turbine combustion systems is stabilized by swirl, the analysis of the swirl flow is very crucial to the design and optimization of such combustion systems. Although a huge amount of publications have been provided on this field just a few have used Large Eddy Simulation due to limits in computer resources. Using Large Eddy Simulation the large vortical structure of the flow is resolved leading to a much better insight of the flow features. Hence, in this paper the Large Eddy Simulation has been applied to investigate the non reacting confined swirling flow downstream of a gas turbine burner. A high accuracy of the prediction of the full three dimensional simulation could be pointed out by comparison of the computational results to measurements. Further the large vortical structure and the dynamic behavior of the flow has been analyzed. The formation of a precessing vortex core is visualized. Due to the precessing motion of the central recirculation zone an alternate vortex shedding at the edges of the burner nozzle is induced. From LES Strouhal numbers for the vortex shedding process are calculated which are confirmed by hot wire measurements.
Combined Back-Side Cooled Combustor Liner and Variable Geometry Injector Technology
Authors: Arellano L. , Smith K. , Fahme A.
Published: July 2014

The need to evolve next-generation ultra-lean premixed systems with advanced air management and improved liner cooling strategies have led Solar to develop a pre-production combustion system for its C50 class engine. The system uses an Augmented Backside Cooled/Thermal Barrier Coated (ABC/TBC) combustor and Variable Geometry injectors. The technology reduces both NOx and CO emissions, while improving part-load cycle efficiency.

The ABC/TBC combustor technology eliminates quenching of the reaction at the walls typically found in combustors using film-cooling techniques. Eliminating this quenching effect is not only conducive to reducing CO emissions, but it also enables the operation of the combustor primary zone at low temperatures to produce minimum thermal NOx. Coupled with a set of variable geometry injectors, the system manages air more effectively to extend the combustor operating range under which emissions and stability limits are maintained. The injectors enable the control of air entering the combustor as a function of engine load and ambient temperature. Such ability reduces the need to bleed high-pressure compressor air at part-load, thus enhancing the engine cycle efficiency.

The pre-production combustion system is currently undergoing field evaluation to assess long-term durability, characterize system performance, and develop optimum control algorithms. The development methodology and experience for this system is discussed in this paper.
CO2 Capture Using a Hydrogen Decomposed From Natural Gas Turbine
Authors: Moritsuka Hideto
Published: July 2014

The present writer proposes a new concept of power generation system for CO2 recovery named Hydrogen Decomposed from Natural Gas Turbine (HYDET) in this paper. This concept is natural gas reforming and hydrogen separation. The natural gas is reformed with steam simultaneously the hydrogen is separated from the reformed gas through the hydrogen separation membrane. After the residual gas is combusted by the after burner with pure oxygen, CO2 steam mixture is exhausted.

An inorganic hydrogen separation membrane will be assumed to use such as ceramic multi-layer porous membranes. The performance of the proposed system will be over 50% HHV at the sending-end. Though the CO2 recovery ratio will depend upon Hydrogen and CO2 separation ratio of the membrane, theoretically it will be over 90%. And using CO2 liquefaction equipment of LNG cold heat exchanger, liquefied CO2 will be recovered with extra high efficiency. In order to apply this system, the development of the membrane reformer is the key technology.
Augmentation of Gas Turbine Power Output by Steam Injection
Authors: Fischer August C. , Frutschi Hans Ulrich , Haselbacher Hermann
Published: July 2014

Steam injection into the combustion chambers of gas turbines (GT) increases their power output. Additionally, the thermal efficiency can be raised, if steam is generated by exhaust heat.

The types of steam injected gas turbines (STIG) are distinguished according to the kind of limit to the amount of steam that can be injected. A gas turbine is called partial STIG, if it cannot utilize the total amount of steam that could be generated by the gas turbine exhaust heat. The limit is given by the flow capacity of the turbine. If, on the other hand, the gas turbine is sized such that the entire amount of steam producible can be utilized, it is called full STIG.

Three different partial STIG cooling models were selected to analyze the power output, the efficiency and the impact on two important components. Since the differences in the results for the three cycles are marginal, the following conclusion can be briefly summarized: Compressor surge turned out to be the strongest limit for overloading the gas turbine. At the point of maximum overload — where safe operation is still guaranteed — the steam mass flow amounts to one tenth of the nominal compressor air mass flow. At this operating point, the power output can be raised by more than 30% with a simultaneous increase in efficiency.

Based on the gas turbine configurations used for the partial STIGs, the preliminary designs of two full STIG cycles have been developed. However, for full STIG operation by injection of the total amount of steam producible, either the compressor or the turbines of the original gas turbine have to be modified. In this case, the steam flow exceeding that required for cooling has to be injected into the compressed air in front of the combustor. Depending on whether the compressor is scaled down or the turbines are scaled up, the power output of full STIGs is 30 to 135% higher than that of the original gas turbine. The gross thermal efficiency is about 50.5.%.
Qassim Central Power Plant Inlet Air Cooling System
Authors: Al Bassam A. , Al Said Y. M.
Published: July 2014

This paper summarizes the experiences with the first gas turbine inlet air cooling project in Saudi Arabia. It will cover the feasibility study, cooling system options, overview, system equipment description, process flow diagram, construction, commissioning, start-up and performance of the project which is currently under commissioning and initial start up at Qassim Central Power Plant (QCPP) owned by Saudi Electric Company (S.E.C.) Central Region Branch.
Predicted Effects of Bearing Sump and Injection Pressures on Oil Labyrinth Leakage
Authors: Park Sung-Young , Rhode David L.
Published: July 2014

New information and an enhanced understanding concerning the oil vapor contaminant leaking through non-flooded oil labyrinth seals are provided. The results were obtained using a finite-volume Navier-Stokes computer code that was extended to include the concentration transport equation. The minimum (i.e. critical) pressure and flow rate at which un-contaminated buffer gas must be injected to prevent oil vapor from leaking to the process gas was determined for a range of seal geometries and operating conditions. It was found that the variation of the critical buffer-gas injection pressure with bearing gas and process gas pressures, for example, was surprisingly small for the cases considered. In addition, the bearing gas and oil vapor flow rates for a wide range of bearing and injection (where present) pressures and geometries were determined for both buffered as well as non-buffered seals.
Study of Losses in a Leakage Flow Through the Passage of Shrouded Turbine Blades With Swirl Velocity
Authors: Xiao Yumin , Amano R. S.
Published: July 2014

In this paper the study of the flows over shrouded turbine blades with staggered-seals is presented by computing the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations along with a compressible non-linear k-ε turbulence model. The swirl of the blade is coupled into the calculation. A multi-zone technique is used to generate the grids in the complex flow channel. The calculation results show that the leakage flow rate in the seal-channel is dominated by the pressure difference. It was also observed that the circumferential momentum transfer in the channel is very slow in the region in front of the seal tooth. The major effect of the rotating blade is the increase of local pressure distribution along the shrouded tip clearance path. However, the swirl motion of the blade tip does not significantly change the flow pattern in the axial-radial plane.
Effects of Bulk Flow Pulsations on Film Cooling With Compound Angle Holes: Heat Transfer Coefficient Ratio and Heat Flux Ratio
Authors: Jung In Sung , Lee Joon Sik , Ligrani P. M.
Published: July 2014

Experiments are conducted to investigate the effects of bulk flow pulsations on film cooling from compound angle holes. A row of five film cooling holes is employed with orientation angles of 0°, 30°, 60°, and 90° at a fixed inclination angle of 35°. Static pressure pulsations are generated using an array of six rotating shutter blades, which extend across the span of the exit of the wind tunnel test section. Pulsation frequencies of 0 Hz, 8 Hz, and 36 Hz, and time-averaged blowing ratios of 0.5, 1.0, and 2.0 are employed. Corresponding coolant Strouhal numbers based on these values then range from 0.20 to 3.6. Spatially-resolved surface heat transfer coefficient distributions are measured (with the film and freestream at the same temperature) using thermochromic liquid crystals. Presented are ratios of surface heat transfer coefficients with and without film cooling, as well as ratios of surface heat flux with and without film cooling. These results, for compound angle injection, indicate that the pulsations cause the film to be spread more uniformly over the test surface than when no pulsations are employed. This is because the pulsations cause the film from compound angle holes to oscillate in both the normal and spanwise directions after it leaves the holes. As a result, the pulsations produce important changes to spatially-resolved distributions of surface heat flux ratios, and surface heat transfer coefficient ratios. In spite of these alterations, only small changes to spatially-averaged heat transfer coefficient ratios are produced by the pulsations. Spatially-averaged surface heat flux ratios, on the other hand, increase considerably at coolant Strouhal numbers larger than unity, with higher rates of increase at larger orientation angles.
Boundary Layer and Loss Analysis in a Film Cooled Vane
Authors: Barigozzi Giovanna , Benzoni Giuseppe , Perdichizzi Antonio
Published: July 2014

The paper reports on boundary layer and wake flow analysis in a fully covered, film cooled vane without trailing edge ejection. The investigation, carried out in a low speed wind tunnel for linear cascades, has been mainly focused on the loss generation process due to coolant injection. The investigated region includes the rear part of pressure and suction side boundary layers and the wake region, up to a chord length downstream of the trailing edge. All measurements have been performed at mid-span, air being used as coolant flow. The same measurements have been also performed on a solid blade cascade, i.e. without cooling holes. Boundary layer profiles, integral parameters together with mean and turbulent quantities are presented. It results that the showerhead promotes transition on the suction side, giving rise to a thicker boundary layer all over the surface. On the pressure side, the boundary layer remains laminar up to the trailing edge, as high acceleration prevents transition. The wake region seems not to be strongly altered by the coolant injection. Boundary layer profiles and downstream 5-hole probe traverses have been used to compute loss coefficient distributions all over the blade surface and in the downstream region. Coolant injection strongly increases the profile losses along the suction side, while a much smaller contribution from the pressure side has been found. These increases are mainly due to coolant injection in the vane front part.
Heat Transfer Characteristics of an Integrated Cooling Configuration for Ultra-High Temperature Turbine Blades: Experimental and Numerical Investigations
Authors: Funazaki K. , Tarukawa Y. , Kudo T. , Matsuno S. , Imai R. , Yamawaki S.
Published: July 2014

This paper deals with fundamental research on heat transfer characteristics inside a cooling configuration designed for an ultra-high temperature turbine nozzle. The cooling configuration adopted in this study integrates impingement cooling and pin cooling devices into one body, aiming at the enhancement of the effective area for the impingement cooling. A large-scaled test model of this cooling system is constructed to measure its internal heat transfer distribution, where a number of pins are sandwiched between an impingement plate and a target plate. The target plate are provided with several air discharging holes. A focus of this study is on how the heat transfer characteristics depend on the effect of stand-off distance: a distance between these two plates. Ratios of the stand-off distance to the impingement hole diameter varies from 0.75 to 2.00. A transient measurement technique using narrow-banded thermochromatic liquid crystal (TLC) is employed to determine the heat transfer characteristics of the model. Numerical investigations using a commercial CFD code are also executed and those results are compared with the experimental data. It is accordingly found that the numerical results almost match the measurements. It is also shown that the addition of pins to the conventional impingement cooling system can produce about 50% increase in the effective cooling area.