bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of obesity on patient survival in liver transplant recipients: a meta‐analysis
Authors: Saab Sammy , Lalezari David , Pruthi Paridhima , Alper Theodore , Tong Myron J.
Published: December 2013

Background & Aims

It is controversial if obesity has an impact on overall survival after liver transplantation (LT). The goal of this study was to determine if obesity impacts liver transplant recipient survival. Through subgroup analysis, we also evaluated different body mass index (BMI) thresholds and the confounding effect of ascites on survival.

Methods

A systematic literature search from 1990 until July 2013. The main outcome was to evaluate the impact of obesity on survival in adult LT recipients. Dochotomous outcomes were reported as relative risk (RR) with 95% confidence intervals (CI).

Results

Thirteen studies with a total 2275 obese and 72 212 non obese patients were included in the analysis. The combined analysis showed no difference in mortality between control and increased weight patients (RR = 0.97, 95% CI [0.82, 1.13], P = 0.66) at last follow‐up. Moreover, no differences in mortality were noted in subgroup analysis comparing different BMI thresholds. There was also no differences in survival when BMI was adjusted for ascites or in studies where the liver disease severity was similar. Obese patients had worse survival than nonobese patients in pooled analysis of studies which had similar causes of liver disease (RR = 0.69, 95% CI [0.52, 0.92], P = 0.01).

Conclusion

The results of our pools analysis suggest that BMI does not specifically impact patient survival. However, obese patients have worse survival when analysis was performed in studies whose cohorts of obese and nonobese patients had similar causes of liver disease.
The role of glucosinolates and the jasmonic acid pathway in resistance of Arabidopsis thaliana against molluscan herbivores
Authors: Falk Kimberly L. , Kästner Julia , Bodenhausen Natacha , Schramm Katharina , Paetz Christian , Vassão Daniel G. , Reichelt Michael , von Knorre Dietrich , Bergelson Joy , Erb Matthias , Gershenzon Jonathan , Meldau Stefan
Published: December 2013

Although slugs and snails play important roles in terrestrial ecosystems and cause considerable damage on a variety of crop plants, knowledge about the mechanisms of plant immunity to molluscs is limited. We found slugs to be natural herbivores of Arabidopsis thaliana and therefore investigated possible resistance mechanisms of this species against several molluscan herbivores. Treating wounded leaves with the mucus residue (‘slime trail’) of the Spanish slug Arion lusitanicus increased wound‐induced jasmonate levels, suggesting the presence of defence elicitors in the mucus. Plants deficient in jasmonate biosynthesis and signalling suffered more damage by molluscan herbivores in the laboratory and in the field, demonstrating that JA‐mediated defences protect A. thaliana against slugs and snails. Furthermore, experiments using A. thaliana mutants with altered levels of specific glucosinolate classes revealed the importance of aliphatic glucosinolates in defending leaves and reproductive structures against molluscs. The presence in mollusc faeces of known and novel metabolites arising from glutathione conjugation with glucosinolate hydrolysis products suggests that molluscan herbivores actively detoxify glucosinolates. Higher levels of aliphatic glucosinolates were found in plants during the night compared to the day, which correlated well with the nocturnal activity rhythms of slugs and snails. Our data highlight the function of well‐known antiherbivore defence pathways in resistance against slugs and snails and suggest an important role for the diurnal regulation of defence metabolites against nocturnal molluscan herbivores.
Pyramidal tract abnormalities in the human fetus and infant with trisomy 18 syndrome
Authors: Miyata Hajime , Miyata Mio , Ohama Eisaku
Published: December 2013

Trisomy 18 or Edwards syndrome is known to exhibit various developmental abnormalities in the central nervous system. We report dominant uncrossed pyramidal tract in trisomy 18 syndrome, based on the postmortem neuropathologic study of eight consecutive autopsied fetuses and infants with trisomy 18 ranging in age from 16 to 39 weeks of gestation, including six males and two females, along with autopsy cases of a stillborn triploid infant with 69XXX and two stillborn infants without chromosomal or neurodevelopmental abnormalities. Five out of eight cases with trisomy 18 showed a larger proportion of uncrossed than crossed pyramidal tract. All of these cases were male, and the anterior corticospinal tract on one side was constantly larger than the contralateral lateral corticospinal tract in the spinal cord on both sides, while the pyramidal tract was hypoplastic in female cases with trisomy 18 and a case with 69XXX. Abnormal pyramidal decussation has been found in cases with posterior fossa malformations such as occipital encephaloceles, Dandy‐Walker malformation, Joubert syndrome and Möbius syndrome, but has not been described in cases with trisomy 18. Our data, together with the previous reports describing uncrossed aberrant ipsilateral pyramidal tract in patients with congenital mirror movements caused by DCC gene mutation in chromosome 18, and hypolasia and hyperplasia of the pyramidal tract in X‐linked recessive disorders caused by L1CAM and Kal1 gene mutations, respectively, suggest a role of trisomy 18 in association with X‐chromosome in the abnormal development of the pyramidal tract.
What Implications for Chinese Soft Power: Charm Offensive or New Hegemony?
Authors: Courmont Barthélémy
Published: December 2013

Officially adopted at the 17th Communist Party Congress in 2007, China's soft‐power strategy combines an intense and extremely active promotion of China, in both diplomatic and cultural aspects, and marks the affirmation of China's global power. Beijing uses Joseph Nye's concept as a tool to serve its international ambitions. But considering the Chinese power, what are the objectives of this charm offensive in the longer term, and what are the limits of the Chinese soft‐power strategy, if any? This article analyzes the different interpretations of the soft power in China, the various strategies followed by the authorities and their implications for the emergence of this country at the international level.
Pediatric hereditary angioedema
Authors: MacGinnitie Andrew J.
Published: December 2013

Hereditary angioedema (HAE) is a lifelong illness characterized by recurrent swelling of the skin, intestinal tract, and, ominously, the upper airway. It is caused by inadequate activity of the protein C1‐inhibitor, with dysfunction in the kallikrein/bradykinin pathway underlying the clinical symptoms. In addition to the physical symptoms, patients experience significant decrements in vocational and school achievement as well as in overall quality of life. Symptoms often begin in childhood and occur by age 20 in most patients, but life‐threatening attacks are uncommon in the pediatric population. The availability of new therapies has transformed the management of HAE.
Invasive Techniques for Pain Management in Palliative Care: A Single Center Experience
Authors: Canser Enrique , Martínez‐Serrano Blanca , Sancho Azahara , Alonso‐Babarro Alberto , Vilches Yolanda , Alonso‐Yanci Eduardo , Gredilla Elena , Gilsanz Fernando
Published: December 2013

To achieve a successful pain control, interventional techniques are required in approximately 15% of the patients admitted to the Palliative Care Service (PCS).

Objectives

To evaluate the frequency and effectiveness of the invasive procedures performed in the PCS of our health area. Other matters studied included complications associated with these procedures, the effects on morphine consumption, and functional status, survival rate, as well as the type and location of pain.

Methods

A descriptive, observational, retrospective study was performed between January 2009 and December 2011. Patients included were considered difficult to manage and required the assistance of the PCS of the University Hospital La Paz (Madrid).

Results

Patients were divided into 3 groups according to the technique used: sympathetic blocks (group S), epidural catheters (group C), and series of plexus, peripheral nerve, or epidural infiltrations (group I). Ninety‐four procedures in 45 patients were performed (3.6% of patients admitted by the PCS). The average mean value of pain intensity before and after procedures decreased significantly (8.6 vs. 3.1, respectively, P < 0.01). The need for strong opioids was reduced (275.5 mg/day previously and 212.8 mg/day after the technique, P < 0.01). The overall complication rate was 16%.

Conclusion

The analgesic efficacy of these techniques has been adequate in all groups. Patients who required epidural catheters had a higher rate of complications.
Relationship between blood levels of propofol and recovery of memory in electroconvulsive therapy
Authors: Imashuku Yasuhiko , Kanemoto Kousuke , Senda Masanori , Matsubara Momoyo
Published: December 2013

Aim

Memory impairment is a potential major adverse effect of electroconvulsive therapy (ECT). Some reports have suggested that propofol, an intravenous anesthetic widely used for general anesthesia in ECT, can minimize adverse effects on memory and cognitive function following ECT. The relation between propofol blood level during ECT and memory impairment after the procedure is unknown. We aimed to determine the relation between predicted blood level of propofol administered by target‐controlled infusion during ECT and memory impairment after the procedure.

Methods

Thirty‐six patients who underwent a total of 260 series of ECT were enrolled as subjects. Anesthesia was induced with intravenous injection of propofol with a target‐controlled infusion pump for predicting blood levels. Orientation and memory testing were performed after completion of ECT. In a subsequent analysis, subjects were divided into early memory recovery (n = 195) and late memory recovery (n = 65) groups. Likewise, for orientation testing,subjects were divided into early recovery (n = 193) and late recovery (n = 67) groups. In both groups, predicted blood propofol levels, total propofol dose, and other variables, such as number of ECT treatments, stimulus energy volume, and spike and slow wave time, were determined for comparison.

Results

Predicted blood propofol levels and propofol total dose were significantly higher in the early memory recovery group, while no significant differences were observed for the other variables. As for orientation, there were no significant differences between the early and late orientation recovery groups.

Conclusions

Our data shows that the predicted blood propofol levels and the total dose influences memory impairment after the ECT.
Internet abusers associate with a depressive state but not a depressive trait
Authors: Huang Andrew Chih Wei , Chen Huai‐En , Wang Ying‐Chou , Wang Le‐Min
Published: December 2013

Aim

The present study investigated three issues: (i) whether Internet abusers display a depressive state without a depressive trait; (ii) which symptoms are shared between Internet abuse and depression; and (iii) which personality characteristics were shown in Internet abusers.

Methods

Ninety‐nine male and 58 female participants aged 18–24 years were screened with the Chen Internet Addiction Scale. After screening, subjects were separated into the high‐ (n = 73) and low‐risk (n = 84) Internet abuser groups. Participants were respectively administered the Chinese version of the Beck Depression Inventory‐II to assess a depressive state and the Minnesota Multiphasic Personality Inventory‐2 to assess a depressive trait.

Results

The present results showed that high‐risk Internet abusers exhibited a stronger depressive state than low‐risk Internet abusers in the Beck Depression Inventory‐II. However, high‐risk Internet abusers didnot show a depressive trait in the Minnesota Multiphasic Personality Inventory‐2 compared to low‐risk Internet abusers. Therefore, high‐risk Internet abuse participants exhibited a depressive state without a depressive trait.

Conclusions

In a comparison of the symptoms of depression and Internet abuse, it was found that high‐risk Internet abuse participants shared some common behavioral mechanisms with depression, including the psychiatric symptoms of loss of interest, aggressive behavior, depressive mood, and guilty feelings. High‐risk Internet abuse participants may be more susceptible to a temporal depressive state but not a permanent depressive trait. The present findings have clinical implications for the prevention and treatment of Internet abuse.
Increased subsequent risk of acute coronary syndrome for patients with depressive disorder: A nationwide population‐based retrospective cohort study
Authors: Lin Yen‐Nien , Lin Cheng‐Li , Chang Yen‐Jung , Peng Chiao‐Ling , Sung Fung‐Chang , Chang Kuan‐Cheng , Kao Chia‐Hung
Published: December 2013

Aim

The purpose of this study was to explore the possible association between subsequent acute coronary syndrome (ACS) risk and depressive disorder.

Methods

We used data from the National Health Insurance system of Taiwan to address the research topic. The exposure cohort contained 10 871 patients with new diagnoses of depressive disorders. Each patient was randomly frequency‐matched for sex and age with four participants from the general population who did not have any ACS history before the index date (control group). Cox's proportion hazard regression analyses were conducted to estimate the relation between depressive disorders and subsequent ACS risk.

Results

Among patients with depressive disorders, the overall risk for developing subsequent ACS was significantly higher than that of the control group (adjusted hazard ratio: 1.88, 95% confidence interval: 1.63–2.17). Further analysis revealed that the higher risk was observed in patients who were male, were of older age, or whose diagnosis was combined with other comorbidities.

Conclusions

The findings from this population‐based retrospective cohort study suggest that depressive disorder is associated with an increased subsequent ACS risk.
Photoprotection and vitamin D: a review
Authors: Kannan Swati , Lim Henry W.
Published: December 2013

The topic of vitamin D is at the forefront of discussions due to evidence suggesting its role in extra‐skeletal health. It is already established that vitamin D plays a key role in skeletal health in young and elderly adults. This vitamin is obtained mainly through sunlight; various factors such as skin pigmentation and seasons affect cutaneous synthesis. Debates about the effects of sunscreen use on cutaneous synthesis of vitamin D have arisen in recent years. An updated review of the literature emphasizes that adequate levels of vitamin D are needed to prevent osteoporosis, falls and fractures in the elderly population. Emerging data also point to its role in cardiovascular disease, auto‐immune conditions and cancers. Normal usage of sunscreen by adults has not shown to decrease cutaneous synthesis of vitamin D. Recommended Daily Allowance for vitamin D, released in 2010, was based on studies examining skeletal effects of this vitamin. Oral intake with vitamin d‐enriched foods or vitamin D supplements is recommended over prolonged ultraviolet exposure to maintain proper serum levels. Patients should not be discouraged from normal usage of sunscreens due to their well‐established photoprotective effects.
Estimates and Standard Errors for Ratios Of Normalizing Constants from Multiple Markov Chains Via Regeneration
Authors: Doss Hani , Tan Aixin
Published: December 2013

In the classical biased sampling problem, we have k densities π1(·), …,πk(·), each known up to a normalizing constant, i.e., for l = 1, …,k, πl(·)=νl(·)/ml, where νl(·) is a known function and ml is an unknown constant. For each l, we have an independent and identically distributed sample from πl, and the problem is to estimate the ratios ml/ms for all l and all s. This problem arises frequently in several situations in both frequentist and Bayesian inference. An estimate of the ratios was developed and studied by Vardi and his co-workers over two decades ago, and there has been much subsequent work on this problem from many perspectives. In spite of this, there are no rigorous results in the literature on how to estimate the standard error of the estimate. We present a class of estimates of the ratios of normalizing constants that are appropriate for the case where the samples from the πls are not necessarily independent and identically distributed sequences but are Markov chains. We also develop an approach based on regenerative simulation for obtaining standard errors for the estimates of ratios of normalizing constants. These standard error estimates are valid for both the independent and identically distributed samples case and the Markov chain case.
Relevant Statistics for Bayesian Model Choice
Authors: Marin Jean-Michel , Pillai Natesh S. , Robert Christian P. , Rousseau Judith
Published: December 2013

The choice of the summary statistics that are used in Bayesian inference and in particular in approximate Bayesian computation algorithms has bearings on the validation of the resulting inference. Those statistics are nonetheless customarily used in approximate Bayesian computation algorithms without consistency checks. We derive necessary and sufficient conditions on summary statistics for the corresponding Bayes factor to be convergent, namely to select the true model asymptotically. Those conditions, which amount to the expectations of the summary statistics differing asymptotically under the two models, are quite natural and can be exploited in approximate Bayesian computation settings to infer whether or not a choice of summary statistics is appropriate, via a Monte Carlo validation.
How do patients with exacerbated chronic obstructive pulmonary disease experience care in the intensive care unit?
Authors: Torheim Henny , Kvangarsnes Marit
Published: December 2013

The aim was to gain insight into how patients with advanced chronic obstructive pulmonary disease (COPD) experience care in the acute phase. The study has a qualitative design with a phenomenological approach. The empirics consist of qualitative in‐depth interviews with ten patients admitted to the intensive care units in two Norwegian hospitals. The interviews were carried out from November 2009 to June 2011. The data have been analysed through meaning condensation, in accordance with Amadeo Giorgi's four‐step method. Kari Martinsen's phenomenological philosophy of nursing has inspired the study. An essential structure of the patients' experiences of care in the intensive care unit by acute COPD‐exacerbation may be described as: Feelings of being trapped in a life‐threatening situation in which the care system assumes control over their lives. This experience is conditioned not only by the medical treatment, but also by the entire interaction with the caregivers. The essence of the phenomenon is presented through three themes which describe the patient's lived experience: preserving the breath of life, vulnerable interactions and opportunities for better health. Acute COPD‐exacerbation is a traumatic experience and the patients become particularly vulnerable when they depend on others for breathing support. The phenomenological analysis shows that the patients experience good care during breath of life preservation when the care is performed in a way that gives patients more insight into their illness and gives new opportunities for the future.
Decreased Plasma IL‐22 Levels and Correlations with IL‐22‐Producing T Helper Cells in Patients with New‐Onset Systemic Lupus Erythematosus
Authors: Lin J. , Yue L. H. , Chen W. Q.
Published: December 2013

Interleukin‐22 (IL‐22) and IL‐22‐producing T helper (Th) cells are involved in the pathogenesis of autoimmune diseases. However, the roles of IL‐22 and IL‐22‐producing T helper cells in systemic lupus erythematosus (SLE) remain unclear. Plasma levels of IL‐22 were measured in 41 patients with SLE (19 new‐onset and 22 relapsing patients) and 20 healthy controls by enzyme‐linked immunosorbent assay (ELISA). Meanwhile, the percentages of CD4+IFN‐γ+ (Th1), CD4+IL‐17+ (Th17) and CD4+IFN‐γ−IL‐17− IL‐22+ (Th22) cells in peripheral lymphocytes were determined by flow cytometry, and plasma IL‐22 autoantibodies were detected by ELISA in 19 new‐onset SLE patients and 20 healthy controls. Plasma IL‐22 levels in new‐onset SLE patients were significantly decreased compared with relapsing SLE patients and healthy controls. After treatment with prednisone and hydroxychloroquine, the levels of plasma IL‐22 in new‐onset SLE patients were obviously increased but still lower than healthy controls. There was a positive correlation between plasma IL‐22 levels and the percentages of Th22 cells, but not Th1 and Th17 cells. Moreover, plasma IL‐22 levels as well as peripheral Th17 and Th22 cells correlated with SLE disease activity index (SLEDAI) scores and erythrocyte sedimentation rate (ESR). High frequencies of plasma IL‐22 autoantibodies were detected in new‐onset SLE patients. However, IL‐22 levels did not correlate with IL‐22 autoantibody. Decreased plasma IL‐22 levels and correlation with Th22 cells may be distinct features in new‐onset SLE. Moreover, IL‐22 and Th22 cell correlated with SLE disease activity.
Association of Cytokine Gene Polymorphisms in Patients with Tuberculosis and Their Household Contacts
Authors: Sivangala R. , Ponnana M. , Thada S. , Joshi L. , Ansari S. , Hussain H. , Valluri V. , Gaddam S.
Published: December 2013

Cytokine gene polymorphisms are known to be associated with functional differences in cytokine regulation and may affect host susceptibility to tuberculosis (TB). Contacts are important group in developing tuberculosis infection and are 10–60 times more likely to develop TB than general population. The present study was carried out in patients with TB (N = 176), their household contacts (HHC; N = 155) from Free Chest TB Clinic PPM DOTS (1TU) covering 500,000 population at Mahavir Hospital and Research Centre, Hyderabad, and healthy controls (HC; N = 170) also included. The association of single‐nucleotide polymorphisms (SNPs) in the promoter region of TNF‐α (−308G/A), IL‐2 (−330T/G), IL‐4 (−589C/T) and in exon region of TGF‐β1 (+869T/C) genes was assessed by ARMS & PCR‐RFLP using specific primers in the above‐mentioned subjects. The differences in allelic or genotypic frequencies of TNF‐α (−308G/A) between patients, their HHC and HC were not statistically significant (P > 0.05). IL‐2 (−330T/G) TG genotype was significantly different between patients, HHC compared to HC (P < 0.002, OR‐1.997, 95%CI‐1.260‐3.168, P < 0.03, OR‐1.602, 955CI‐1.003‐2.561).IL‐4 (−589C/T) CC genotype was significantly different between patients and HC (P < 0.03, OR‐1.791, 95%CI‐1.009‐3.189) as well as between HHC and HC at P < 0.0001, OR‐2.56, 95%CI‐1.448‐4.545. In addition, the TGF‐β 1 (+869T/C) TC genotype was significantly associated with susceptibility to tuberculosis in patients when compared against HC(P < 0.0001, OR‐3.416, 95%CI‐2.063‐5.670) and HHC (P < 0.0001, OR‐2.357, 95%CI‐1.439‐3.868), respectively.MDR analysis indicated that TT genotype of TGF‐β1 with TT and CT genotypes of IL‐4 showed high risk with GA, TT genotypes of TNF‐α, IL‐2, respectively. Our results suggest that IL‐2 (‐330T/G), IL‐4 (‐589 C/T) and TGF‐β1 (+869T/C) gene polymorphisms may be associated with TB susceptibility.
The Good Cause Account of the Meaning of Life
Authors: Smuts Aaron
Published: December 2013

I defend the theory that one's life is meaningful to the extent that one promotes the good. Call this the good cause account (GCA) of the meaning of life. It holds that the good effects that count towards the meaning of one's life need not be intentional. Nor must one be aware of the effects. Nor does it matter whether the same good would have resulted if one had not existed. What matters is that one is causally responsible for the good. I argue that the best theory of the meaning of life should clearly distinguish between subjective fulfillment and objective meaningfulness. The GCA respects the distinction. And it is superior to its leading rivals in the recent literature, most notably those of Erik Wielenberg and Susan Wolf.
Estimating the costs of implementing the rotavirus vaccine in the national immunisation programme: the case of Malawi
Authors: Madsen Lizell B. , Ustrup Marte , Hansen Kristian S. , Nyasulu Peter S. , Bygbjerg Ib C. , Konradsen Flemming
Published: December 2013

Objectives

Worldwide, rotavirus infections cause approximately 453 000 child deaths annually. Two licensed vaccines could be life‐ and cost‐saving in low‐income countries where the disease burden is highest. The aim of our study was to estimate the total cost of implementing the rotavirus vaccine in the national immunisation programme of a low‐income country. Furthermore, the aim was to examine the relative contribution of different components to the total cost.

Methods

Following the World Health Organization guidelines, we estimated the resource use and costs associated with rotavirus vaccine implementation, using Malawi as a case. The cost analysis was undertaken from a governmental perspective. All costs were calculated for a 5‐years period (2012–2016) and discounted at 5%. The value of key input parameters was varied in a sensitivity analysis.

Results

The total cost of rotavirus vaccine implementation in Malawi amounted toUS$ 18.5 million over a 5‐years period. This translated intoUS$ 5.8 per child in the birth cohort. WithGAVIAlliance financial support, the total cost was reduced toUS$ 1.4 per child in the birth cohort. Approximately 83% of the total cost was attributed to vaccine purchase, while 17% was attributed to system costs, with personnel, transportation and cold chain as the main cost components.

Conclusion

The total cost of rotavirus vaccine implementation in Malawi is high compared with the governmental health budget ofUS$ 26 per capita per year. This highlights the need for new financing opportunities for low‐income countries to facilitate vaccine implementation and ensure sustainable financing.
In Vivo Neuron‐Wide Analysis of Synaptic Vesicle Precursor Trafficking
Authors: Maeder Celine I. , San‐Miguel Adriana , Wu Emily Ye , Lu Hang , Shen Kang
Published: December 2013

During synapse development, synaptic proteins must be targeted to sites of presynaptic release. Directed transport as well as local sequestration of synaptic vesicle precursors (SVPs), membranous organelles containing many synaptic proteins, might contribute to this process. Using neuron‐wide time‐lapse microscopy, we studied SVP dynamics in the DA9 motor neuron in Caenorhabditis elegans. SVP transport was highly dynamic and bi‐directional throughout the entire neuron, including the dendrite. While SVP trafficking was anterogradely biased in axonal segments prior to the synaptic domain, directionality of SVP movement was stochastic in the dendrite and distal axon. Furthermore, frequency of movement and speed were variable between different compartments. These data provide evidence that SVP transport is differentially regulated in distinct neuronal domains. It also suggests that polarized SVP transport in concert with local vesicle capturing is necessary for accurate presynapse formation and maintenance. SVP trafficking analysis of two hypomorphs for UNC‐104/KIF1A in combination with mathematical modeling identified directionality of movement, entry of SVPs into the axon as well as axonal speeds as the important determinants of steady‐state SVP distributions. Furthermore, detailed dissection of speed distributions for wild‐type and unc‐104/kif1a mutant animals revealed an unexpected role for UNC‐104/KIF1A in dendritic SVP trafficking.
A mycobacterial coinfection in a dog suspected on blood smear
Authors: Etienne Claire‐Lise , Granat Fanny , Trumel Catherine , Raymond‐Letron Isabelle , Lucas Marie‐Noëlle , Boucraut‐Baralon Corine , Pingret Jean‐Luc , Magne Laurent , Delverdier Maxence
Published: December 2013

A 4‐year‐old neutered female crossbred Shepherd was referred for a history of 10 days of anorexia, polyuria, polydipsia, polyadenomegaly, and diarrhea. On physical examination, the dog appeared quiet, responsive, and apyretic, with generalized and severe lymphadenomegaly. Hematologic abnormalities included neutrophilic leukocytosis with left shift, and lymphopenia. Blood smears revealed intracytoplasmic bacilli negatively stained with May–Grünwald–Giemsa in neutrophils and monocytes. Lymph node smears revealed pyogranulomatous adenitis with calcified deposits and many negative‐staining rod structures, both within the cytoplasm of neutrophils and macrophages, and free in the background. An acid‐fast stain (Ziehl–Neelsen) confirmed the diagnosis of mycobacterial infection. The dog was euthanized for public health and ethical reasons, and the postmortem examination revealed severe and generalized granulomatous and necrotizing lymphadenitis, panniculitis, and hepatitis, and infiltration of epithelioid macrophages in the lungs, colon, and spleen. Numerous acid‐fast bacilli, consistent with mycobacterial infection, were observed both in the cytoplasm of epithelioid macrophages and giant cells, and free in the background.Mycobacterium boviswas first confirmed by conventionalPCRof organ extracts.Mycobacterium aviumwas detected in a culture of the same organs. FurtherPCRamplifications and sequencing revealed a coinfection with 2 different species of mycobacterium, one belonging to theMycobacterium aviumcomplex and the other to theMycobacterium tuberculosiscomplex.
Comparison of plasma free metanephrines between healthy dogs and 3 dogs with pheochromocytoma
Authors: Green Bradley A. , Frank Elizabeth L.
Published: December 2013

Background

Adrenomegaly and hypertension are common clinical entities in canine medicine for which testing for pheochromocytoma is recommended. Yet, a validated biochemical test for the diagnosis of pheochromocytoma in dogs does not exist. In human medicine, plasma free metanephrine testing is the diagnostic standard for the biochemical diagnosis of pheochromocytoma.

Objectives

The purpose of this study was to investigate the utility of measurement of plasma free metanephrines in dogs for the diagnosis of pheochromocytoma.

Methods

Plasma free metanephrines were measured in 11 healthy dogs and in 3 dogs confirmed to have a pheochromocytoma. The metanephrine assays were performed at a reference laboratory using high‐performance liquid chromatography with electrochemical detection.

Results

The plasma free metanephrine and normetanephrine concentrations in 11 healthy dogs were normally distributed and were used to create tentative reference intervals. All 3 dogs with histologically confirmed pheochromocytoma clearly had higher concentrations of plasma free metanephrines.

Conclusions

This pilot study demonstrates the potential utility of plasma free metanephrines levels for the biochemical diagnosis of pheochromocytoma in dogs.
Discussion of “Mechanics of Confined Thin-Walled Cylinders Subjected to External Pressure,” (Vasilikis, D., and Karamanos, S., 2014, Appl. Mech. Rev., 66(1), p. 010801)
Authors: Gresnigt Arnold M.
Published: December 2013

The collapse pressure of confined cylinders depends on many factors. In addition to the thorough investigations of Vasilikis and Karamanos, more factors can be candidates for further investigation, such as the effect of variations in the material mechanical properties of the liner pipe in compression and the effect of residual stresses. The mechanical response of the materials in compression depends on the type of steel and the stress-strain history, which depends on the fabrication method of the cylinder. This is illustrated with theoretical and experimental results on pipes under external pressure, as used in offshore applications. There is a need for more experimental test results for validation. More applications of confined cylinders are mentioned that are worth investigation.
Reduced-Order Modeling of Low Mach Number Unsteady Microchannel Flows
Authors: Issa Leila , Lakkis Issam
Published: December 2013

We present reduced-order models of unsteady low-Mach-number ideal gas flows in two-dimensional rectangular microchannels subject to first-order slip-boundary conditions. The pressure and density are related by a polytropic process, allowing for isothermal or isentropic flow assumptions. The Navier–Stokes equations are simplified using low-Mach-number expansions of the pressure and velocity fields. Up to first order, this approximation results in a system that is subject to no-slip condition at the solid boundary. The second-order system satisfies the slip-boundary conditions. The resulting equations and the subsequent pressure-flow-rate relationships enable modeling the flow using analog circuit components. The accuracy of the proposed models is investigated for steady and unsteady flows in a two-dimensional channel for different values of Mach and Knudsen numbers.
Thermal Optimization of a Solar Thermal Cooling Cogeneration Plant at Low Temperature Heat Recovery
Authors: Srinivas T. , Reddy B. V.
Published: December 2013

A simple cooling cogeneration has been developed by coupling a Kalina cycle system (KCS) with a vapor absorption refrigeration (VAR) system. The working fluid used in this theoretical thermodynamic evaluation is ammonia water mixture. A low temperature heat recovery (150 °C–200 °C) from engine exhaust gas, solar collectors, or similar can be used to operate the plant. A controlling facility is provided to set the required amount of power or cooling to meet the variable demand. In this proposed plant, the liquid refrigerant absorbs more amount of heat from evaporator surroundings with a flow control located in between power and cooling cycles. The extra included components are condenser, heat exchanger and throttling device over KCS plant. Due to possibility of more cooling, it offers high energy utilization factor (EUF). The coupled plant characteristics are studied with changes in mass split ratio, separator vapor fraction, separator temperature, and turbine concentration to develop efficient working conditions. The power mass split ratio is varied from 80% to 100% to run the coupled plant at nearly full load conditions. The separator vapor fraction and temperature are optimized at 45% and 150 °C, respectively. It is recommended to maintain the turbine concentration above 0.85 for optimum power and cooling. The maximum cycle EUF and plant EUF are 0.15 and 0.06, respectively, at 80% power mass split ratio. The specific power and specific cooling at these conditions are 62 kW/kg and 72 kW/kg, respectively.
Determination of Transmission Loss in Slightly Distorted Circular Mufflers Using a Regular Perturbation Method
Authors: Banerjee Subhabrata , Jacobi Anthony M.
Published: December 2013

A perturbation-based approach is implemented to study the sound attenuation in distorted cylindrical mufflers with various inlet/outlet orientations. Study of the transmission loss (TL) in mufflers requires solution of the Helmholtz equation. Exact solutions are available only for a limited class of problems where the method of separation of variables can be applied across the cross section of the muffler (e.g., circular, rectangular, elliptic sections). In many practical situations, departures from the regular geometry occur. The present work is aimed at formulating a general procedure for determining the TL in mufflers with small perturbations on the boundary. Distortions in the geometry have been approximated by Fourier series expansion, thereby, allowing for asymmetric perturbations. Using the method of strained parameters, eigensolutions for a distorted muffler are expressed as a series summation of eigensolutions of the unperturbed cylinder having similar dimensions. The resulting eigenvectors, being orthogonal up to the order of truncation, are used to define a Green's function for the Helmholtz equation in the perturbed domain. Assuming that inlet and outlet ports of the muffler are uniform-velocity piston sources, the Green's function is implemented to obtain the velocity potential inside the muffler cavity. The pressure field inside the muffler is obtained from the velocity potential by using conservation of linear momentum. Transmission loss in the muffler is derived from the averaged pressure field. In order to illustrate the method, TL of an elliptical muffler with different inlet/outlet orientations is considered. Comparisons between the perturbation results and the exact solutions show excellent agreement for moderate (0.4∼0.6) eccentricities.
The Impact of Rotor Inlet Cavity Volume and Length Scale on Efficiency
Authors: Barmpalias Konstantinos G. , Abhari Reza S. , Kalfas Anestis I. , Shibukawa Naoki , Sasaki Takashi
Published: December 2013

The interaction between the cavity and the main flows accounts for a considerable amount of the overall aerodynamic losses in axial turbomachinery. Experimental work supplemented by a computational analysis is presented in this paper on the impact of rotor inlet cavity volume and length scale on turbine stage efficiency. Inlet cavity volume and geometry have been systematically varied. The flow interactions occurring at the cavity inlet between the cavity and main flows and their subsequent impact on efficiency were studied. Five different configurations have been examined within this study. The radial cavity wall has been shortened by 13% and 25% compared to the initial cavity length. Cavity volume has been reduced by 14% and 28% respectively. An additional rounding introduced at the upper right corner of the cavity generated two more variations. Efficiency was increased by 1.1% and 1.6% for the 14% and 28% cavity volume reductions, respectively. The rounding introduced led only to efficiency deficits as the strengthening of the cavity vortex caused increased interaction at the cavity inlet area.
Evolution of Thermal Barrier Coating Strain Tolerance During Engine Operation and its Application to Lifing Models
Authors: Schaudinn Markus , Witz Grégoire , Bossmann Hans-Peter
Published: December 2013

Models for thermal barrier coating lifetime prediction are often based on bondcoat oxidation models leading to an end of life criterion either based on bondcoat full consumption or a critical thermally grown oxide thickness. Such models can be satisfactory on turbine parts where the most common coating delamination modes are black or grey failure which are linked to the bondcoat behaviour. Such models are not reliable for combustor parts with thick thermal barrier coating systems where the most common life limiting factor is the formation of cracks appearing in the ceramic layer few tens of microns above the bondcoat interface. This behaviour is linked to the TBC layer mechanical properties and should be described by a model taking into account the evolution of the TBC mechanical properties during engine operation, the mechanical loads in the ceramic layer and a crack propagation model in the TBC. A study of the strain tolerance of TBC from combustor parts after engine operation was performed by taking samples from combustor liners at various locations having different TBC surface temperature. The strain tolerance of TBC samples was measured by four-point bending and correlated with the TBC microstructure and various engine operation parameters. It was shown that the TBC microstructure has an influence on TBC strain tolerance, and that the evolution of the TBC strain tolerance during engine operation is linked to the TBC temperature as well as the operating hours. The data have been used to develop a predictive model of the evolution of the TBC strain tolerance during engine operation. This model allows optimization of parts reconditioning interval, and provides tools for determining the residual life of coated components.
CTOD Application to Elastic-Plastic Fracture Mechanics Using Cyclic Ramberg-Osgood Law and HRR Solution
Authors: Bednarz Piotr , Fedorov Ilya , Szwedowicz Jaroslaw
Published: December 2013

Very often in the open literature the crack propagation simulation is based on the linear elastic fracture mechanics. This article describes a novel application of the cyclic crack tip opening displacement (ΔCTOD) method for evaluation of the cyclic nonlinear energy release rate under large plasticity and cyclic loading conditions. In order to consider the cyclic loading in the Hutchinson-Rice-Rosengren (HRR) solution, the monotonic plastic deformation of the material behaviour needs to be replaced by its cyclic counterpart. During cyclic loading conditions, a reverse plasticity occurs and leads to a crack closure effect via blunting of the crack tip. As a result, crack flanks are in contact during compression. This effect is determined from the effective difference between the maximum and minimum crack deformation. Then, the cyclic crack tip opening displacement is evaluated by applying the Shih rule. The proposed extension of the HRR solution in application to cyclic loading conditions via stress and strain transformation as well as accounting for the crack closure effect is validated in a good agreement with Dowling and Begley Compact Tension (CT) experiment. Potential crack closure due to crack surface roughness is neglected in current modeling. The proposed methodology extends the existing HRR solution for the reliable lifetime prediction.
Numerical Simulation of Tool/Abradable Material Interaction Experiments
Authors: Batailly Alain , Cuny Marion , Legrand Mathias
Published: December 2013

Applying abradable coating on the casing of turbomachines has been widely recognized as a robust solution advantageously combining the adjustment of operating clearances with the reduction of potential non-repairable damages. Thus, the modeling of this material is a growing field of investigation. Based on the numerical strategy proposed and detailed in previous publication by the same authors, the present study aims at capturing the mechanical behavior of abradable coating in the context of high speed interaction with a rigid tool. The plastic law given is first enriched in order to take into account strain rate dependence. The sensitivity of the model regarding its main numerical parameters is assessed and highlights the role of each of these parameters. The calibration of numerical results with respect to experimental results lead to very satisfying results that confirm that the proposed strategy is well-suited for the modeling of abradable coating. Finally, the newly developped viscoplastic law is applied to a 3D rotor/stator interaction case to determine the criticity of strain rate dependence in the case of blade/casing contact.
Aeroelasticity at Reversed Flow Conditions: Part 3—Reduction of Surge Loads by Means of Intentional Mistuning
Authors: Schoenenborn Harald , de Vries Mirja
Published: December 2013

Compressor surge consists of four phases: (i) pressure rise, (ii) flow breakdown, (iii) blow-down and (iv) flow recovery. During the blow-down phase reversed flow conditions exist, where a blade may accumulate hundreds of vibration cycles, depending on the surge volume and the vibration frequency. High vibration amplitudes and blade damages were observed in the past.

In part 1 (GT2011-45034) a compressor cascade was analyzed experimentally and analytically at steady reversed flow conditions. It has been shown that (i) the steady flow field can be predicted well by CFD analysis, (ii) the overall damping coefficient calculated by unsteady CFD compares reasonably well with measurements and (iii) a blade may become unstable at certain reversed flow conditions.

In part 2 (GT2011-45035) the analytical procedures used in part 1 were applied to the front part of a multi-stage HPC for reversed flow conditions. It was found that surge loads consist in reality of two physically different phenomena: (i) the pressure wave during the flow breakdown leading to rather low blade stresses and (ii) flutter during the blow-down phase which may lead to very high blade stresses and damages during surge for some stages.

As it is well known that intentional mistuning is a way to mitigate flutter, intentional mistuning is investigated in part 3 of the paper at reversed flow conditions. At first, a CFD study of a single airfoil is presented showing the dependency of aerodynamic damping upon flow angle and pressure ratio over the airfoil at reversed flow conditions, including intentional mistuning studies.

Secondly, an investigation is presented which shows experimentally and analytically that surge stresses can be reduced significantly by the use of intentional mistuning. In a multi-stage compressor test rig, one rotor stage, which experienced very high stresses during surge, was subjected to a cutback on every second blade, leading to significantly reduced surge stresses. Analytically, an aeroelastic eigenvalue analysis showed the same behavior.
Flexible and Economical Operation of Power Plants: 25 Years of Expertise
Authors: Greis Jan , Gobrecht Edwin , Wendt Steffen
Published: December 2013

Within the last years the idea of running a conventional power plant has changed. Fluctuating power generation by solar power and wind parks creates a need for highly flexible backup power plants. This need quickly arose within the last 5 years and the market is still searching for a solution.

Single steam turbine manufacturers can provide features to react more flexibly, quickly and to prolong component life time. Thus, considerable operating experience has already been in existence for many years.

New highly efficient steam turbines are already equipped with solutions to serve an ambitious market. But also, for existing units, different modernization packages can be provided along with hardware and software modifications which allow power plants to supply power at a moment’s notice.

This paper presents the overall approach and the possible field of application for the well-established features of Siemens steam turbines.

Starting a power plant within a short time to fill the gap of fluctuating power generation is an important capability in order to participate in today’s and tomorrow’s energy market. A fully automated start-up procedure to avoid any delays contributes in fulfilling this requirement. Optimized component geometries guarantee the shortest start-up times. Furthermore, a parallel start-up of gas and steam turbines (Hot Start on the Fly) has already been proven for many years.

Regarding flexibility, the improvement of start-up time is only one major aspect. Another important task is to provide the opportunity to influence scheduled maintenance outages. Therefore, steam turbines can be equipped with software which allows the customer to plan the power plant’s outages in accordance with single components requirements, e.g. GT outages. The lifecycle counter enables customers to evaluate the optimum between start-up time and life time consumption based on dynamic equivalent operating hours.

In addition, fast cooling procedures help to keep outage times to a minimum.