bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral Perfusion is Associated With White Matter Hyperintensities in Older Adults With Heart Failure
Authors: Alosco Michael L. , Brickman Adam M. , Spitznagel Mary Beth , Garcia Sarah L. , Narkhede Atul , Griffith Erica Y , Raz Naftali , Cohen Ronald , Sweet Lawrence H. , Colbert Lisa H. , Josephson Richard , Hughes Joel , Rosneck Jim , Gunstad John
Published: March 2013

Cognitive impairment is common in heart failure (HF) and believed to be the result of cerebral hypoperfusion and subsequent brain changes including white matter hyperintensities (WMHs). The current study examined the association between cerebral blood flow and WMHs in patients with HF and the relationship between WMHs and cognitive impairment. Sixty‐nine patients with HF completed the Mini‐Mental State Examination (MMSE) and underwent echocardiography, transcranial Doppler sonography for cerebral blood flow velocity of the middle cerebral artery, and brain magnetic resonance imaging. Multivariable hierarchical regression analyses controlling for medical and demographic characteristics as well as intracranial volume showed reduced cerebral blood flow velocity of the middle cerebral artery was associated with greater WMHs (β=−0.34, P=.02). Follow‐up regression analyses adjusting for the same medical and demographic factors in addition to cerebral perfusion also revealed marginal significance between increased WMHs and poorer performance on the MMSE (β=−0.26, P=.05). This study suggests that reduced cerebral perfusion is associated with greater WMHs in older adults with HF. These findings support the widely proposed mechanism of cognitive impairment in HF patients and prospective studies are needed to confirm these results.
COMPARISON AND SELECTION OF OBJECTIVE FUNCTIONS IN MULTIOBJECTIVE COMMUNITY DETECTION
Authors: Shi Chuan , Yu Philip S. , Yan Zhenyu , Huang Yue , Wang Bai
Published: March 2013

Detecting communities of complex networks has been an effective way to identify substructures that could correspond to important functions. Conventional approaches usually consider community detection as a single‐objective optimization problem, which may confine the solution to a particular community structure property. Recently, a new community detection paradigm is emerging: multiobjective optimization for community detection, which means simultaneously optimizing multiple criteria and obtaining a set of community partitions. The new paradigm has shown its advantages. However, an important issue is still open: what type of objectives should be optimized to improve the performance of multiobjective community detection? To exploit this issue, we first proposed a general multiobjective community detection solution (called NSGA‐Net) and then analyzed the structural characteristics of communities identified by a variety of objective functions that have been used or can potentially be used for community detection. After that, we exploited correlation relations (i.e., positively correlated, independent, or negatively correlated) between any two objective functions. Extensive experiments on both artificial and real networks demonstrate that NSGA‐Net optimizing over a pair of negatively correlated objectives usually leads to better performances compared with the single‐objective algorithm optimizing over either of the original objectives, or even to other well‐established community detection approaches.
Analysis of transfer lesions in patients who underwent surgery for diabetic foot ulcers located on the plantar aspect of the metatarsal heads
Authors: Molines‐Barroso R. J. , Lázaro‐Martínez J. L. , Aragón‐Sánchez J. , García‐Morales E. , Beneit‐Montesinos J. V. , Álvaro‐Afonso F. J.
Published: March 2013

Aims

To analyse the risk of reulceration caused by the transfer of lesions in patients with diabetes, undergoing resection of at least one metatarsal head.

Methods

A total of 119 patients with diabetes from the Diabetic Foot Unit (Complutense University, Madrid, Spain), who underwent resection of at least one metatarsal head were analysed prospectively from November 2006 to December 2011 to assess reulceration in the other metatarsal head.

Results

Seven patients were excluded for being subjected to a pan‐metatarsal head resection and 11 patients dropped out. During a median follow‐up period of 13.1 months (interquartile range 6.1–22.8 months), 41% of patients suffered from reulcerations. Reulceration frequency in patients operated on the 1st, 2nd, 3rd, 4th, 5th and several metatarsal heads was 9 (69%), 8 (44%), 12 (52%), 2 (25%), 6 (19%) and 4 (50%) events, respectively. The Cox regression model showed hazard ratios that were significant for the location of the metatarsal resection. The first metatarsal showed the highest risk for reulceration (hazard ratio 3.307; 1.472–7.430) and the fifth metatarsal showed the lowest risk (hazard ratio 0.339; 0.138–0.832).

Conclusions

Reulceration is a frequent event following resection of a metatarsal head and should be regarded as an implicit complication of the intervention. The location of the resection determines the risk of reulceration, which is highest for patients operated on the first metatarsal head and lowest for patients operated on the fifth metatarsal head.
Surfing the (endo)cannabinoids wave
Authors: Finazzi Agrò Alessandro , Maccarrone Mauro
Published: March 2013

Accompanied by a podcast, listen now. Or listen in iTunes
Role and interpretation of fluorodeoxyglucose‐positron emission tomography/computed tomography in HIV‐infected patients with fever of unknown origin: a prospective study
Authors: Martin C , Castaigne C , Tondeur M , Flamen P , De Wit S
Published: March 2013

Objectives

The aim of the study was to evaluate prospectively the usefulness of fluorodeoxyglucose‐positron emission tomography/computed tomography (FDG‐PET/CT) in investigation of fever of unknown origin (FUO) in HIV‐positive patients and to determine whether HIV viraemia impacts on FDG‐PET/CT performance.

Methods

The FDG‐PET/CT results of 20 HIV‐infected patients with FUO were analysed and compared with the FDG‐PET/CT results of 10 HIV‐infected viraemic patients without FUO. The performance of FDG‐PET/CT for identifying the aetiology of FUO was assessed. Final diagnosis for FUO was based on histopathology, microbiological assays, or clinical and imaging follow‐up.

Results

FDG‐PET/CT contributed to the diagnosis or exclusion of a focal aetiology of the febrile state in 80% of patients with FUO. The presence of increased FDG uptake in the central lymph node has 100% specificity for focal aetiology of fever, even in viraemic patients. The absence of hypermetabolic central lymph nodes in FUO patients has 100% negative predictive value for focal disease. Lymph node biopsy in central hypermetabolic areas allowed, in 100% of cases, identification of underlying disease in patients with FUO. Biopsy of peripheral lymph nodes should be performed in lymph nodes with maximum standardized uptake value (SUVmax) ≥ 6–8 (sensitivity 62.5%; specificity 75%) and avoided in lymph nodes with SUVmax = 0–4 (specificity 0%). High HIV viraemia does not prevent correct interpretation of FDG‐PET/CT.

Conclusions

As in HIV‐negative patients, we confirm the usefulness of FDG‐PET/CT in investigation of FUO in HIV‐positive patients even if they are viraemic.
Some Reflections on the Possible Introduction of Electronic Monitoring as an Alternative to Pre‐trial Detention in Belgium
Authors: Maes Eric , Mine Benjamin
Published: March 2013

Prison overcrowding is a major problem in the Belgian criminal justice system, with 40% of the current population consisting of prisoners remanded in custody. Driven by a goal of prison overcrowding prevention, electronic monitoring has been implemented nationally since 2000, but only as an alternative to the execution of the entire, or a part of the prison sentence imposed. This article aims to report some final results of recent research on the possible application of electronic monitoring as an alternative to remand custody in Belgium, more particularly with regard to some important legal, practical and organisational questions.
Applicability of second‐generation colon capsule endoscope to ulcerative colitis: A clinical feasibility study
Authors: Hosoe Naoki , Matsuoka Katsuyoshi , Naganuma Makoto , Ida Yosuke , Ishibashi Yuka , Kimura Kayoko , Yoneno Kazuaki , Usui Shingo , Kashiwagi Kazuhiro , Hisamatsu Tadakazu , Inoue Nagamu , Kanai Takanori , Imaeda Hiroyuki , Ogata Haruhiko , Hibi Toshifumi
Published: March 2013

Background and Aim

Colon capsule endoscopy has already been used for colon visualization and detection of polyps but its applicability to inflammatory bowel disease is still unconfirmed. The aim of this study was to assess the feasibility of evaluating the severity of mucosal inflammation in patients with ulcerative colitis (UC) using a second‐generation colon capsule endoscope (CCE‐2).

Methods

Forty patients with histological confirmed diagnosis of UC were enrolled. Low‐volume (2 L) polyethylene glycol solution with prokinetics (mosapride citrate and metoclopramide) regimen was used for the bowel preparation. In Phase 1, consisting of 10 patients, to confirm appropriate CCE‐2 bowel preparation for UC. In Phase 2, consisting of 30 patients, CCE‐2 was performed with a fixed bowel preparation regimen. CCE‐2 findings were recorded for 8 h starting from capsule ingestion and conventional colonoscopy was subsequently performed on the same day. CCE‐2 procedure completion rate and the colon cleansing level with a 4‐point grading scale (poor, fair, good, and excellent) were evaluated in Phase 2. Correlations between Matts endoscopic scores as judged by CCE‐2 and conventional colonoscopy were calculated.

Results

CCE‐2 procedure was completed within 8 h in 69% of the patients. The proportion of patients with good or excellent cleansing level was below 50%. However, Matts endoscopic scores determined by CCE‐2 showed a strong correlation with scores obtained by conventional colonoscopy (average ρ = 0.797).

Conclusions

Although modifications in bowel preparation are needed, CCE‐2 might be feasible for assessing the severity of mucosal inflammation in patients with UC.
Are Environmental Influences on Physical Activity Distinct for Urban, Suburban, and Rural Schools? A Multilevel Study Among Secondary School Students in Ontario, Canada
Authors: Hobin Erin P. , Leatherdale Scott , Manske Steve , Dubin Joel A. , Elliott Susan , Veugelers Paul
Published: March 2013

BACKGROUND

This study examined differences in students' time spent in physical activity (PA) across secondary schools in rural, suburban, and urban environments and identified the environment‐level factors associated with these between school differences in students' PA.

METHODS

Multilevel linear regression analyses were used to examine the environment‐ and student‐level characteristics associated with time spent in PA among grades 9 to 12 students attending 76 secondary schools in Ontario, Canada, as part of the SHAPES‐Ontario study. This approach was first conducted with the full data set testing for interactions between environment‐level factors and school location. Then, school‐location specific regression models were run separately.

RESULTS

Statistically significant between‐school variation was identified among students attending urban (σ2μ0 = 8959.63 [372.46]), suburban (σ2μ0 = 8918.75 [186.20]), and rural (σ2μ0 = 9403.17 [203.69]) schools, where school‐level differences accounted for 4.0%, 2.0%, and 2.1% of the variability in students' time spent in PA, respectively. Students attending an urban or suburban school that provided another room for PA or was located within close proximity to a shopping mall or fast food outlet spent more time in PA.

CONCLUSION

Students' time spent in PA varies by school location and some features of the school environment have a different impact on students' time spent in PA by school location. Developing a better understanding of the environment‐level characteristics associated with students' time spent in PA by school location may help public health and planning experts to tailor school programs and policies to the needs of students in different locations.
Mixed Infection of Two Groups (16SrI & V) of Phytoplasmas in a Single Jujube Tree in China
Authors: Sun Xian‐Chao , Mou Hai‐Qing , Li Ting‐Ting , Tian Qian , Zhao Wen‐Jun
Published: March 2013

Symptoms similar to Jujube witches' broom disease were observed on jujube (Zizyphus jujuba) plants in an orchard in Xuchang City, Henan Province, China. Phytoplasmas were detected in one sample from symptomatic plants by nested PCR assay employing 16S rRNA gene primers P1/P7 followed by R16F2n/R16R2. Virtual RFLP analysis of the resulting products (F2nR2 region) shown that total of two different groups (16SrI and 16SrV) phytoplasmas associated with the infected jujube. This is the first report of phytoplasmas mixed infection of jujube in China.
Vegetation change and homogenization of species composition in temperate nutrient deficient Scots pine forests after 45 yr
Authors: Reinecke Jennifer , Klemm Gunther , Heinken Thilo
Published: March 2013

Question

Does eutrophication drive vegetation change in pine forests on nutrient deficient sites and thus lead to the homogenization of understorey species composition?

Location

Forest area (1600 ha) in the Lower Spreewald, Brandenburg, Germany.

Methods

Resurvey of 77 semi‐permanent plots after 45 yr, including vascular plants, bryophytes and ground lichens. We applied multidimensional ordination of species composition, dissimilarity indices, mean Ellenberg indicator values and the concept of winner/loser species to identify vegetation change between years. Differential responses along a gradient of nutrient availability were analysed on the basis of initial vegetation type, reflecting topsoil N availability of plots.

Results

Species composition changed strongly and overall shifted towards higher N and slightly lower light availability. Differences in vegetation change were related to initial vegetation type, with strongest compositional changes in the oligotrophic forest type, but strongest increase of nitrophilous species in the mesotrophic forest type. Despite an overall increase in species number, species composition was homogenized between study years due to the loss of species (mainly ground lichens) on the most oligotrophic sites.

Conclusions

The response to N enrichment is confounded by canopy closure on the N‐richest sites and probably by water limitation on N‐poorest sites. The relative importance of atmospheric N deposition in the eutrophication effect is difficult to disentangle from natural humus accumulation after historical litter raking. However, the profound differences in species composition between study years across all forest types suggest that atmospheric N deposition contributes to the eutrophication, which drives understorey vegetation change and biotic homogenization in Central European Scots pine forests on nutrient deficient sites.
Petrography, mineral chemistry, and crystallization history of olivine‐phyric shergottite NWA 6234: A new melt composition
Authors: Gross Juliane , Filiberto Justin , Herd Christopher D. K. , Daswani Mohit Melwani , Schwenzer Susanne P. , Treiman Allan H.
Published: March 2013

Knowledge of Martian igneous and mantle compositions is crucial for understanding Mars' mantle evolution, including early differentiation, mantle convection, and the chemical alteration at the surface. Primitive magmas provide the most direct information about their mantle source regions, but most Martian meteorites either contain cumulate olivine or crystallized from fractionated melts. The new Martian meteorite Northwest Africa (NWA) 6234 is an olivine‐phyric shergottite. Its most magnesian olivine cores (Fo78) are in Mg‐Fe equilibrium with a magma of the bulk rock composition, suggesting that it represents a melt composition. Thermochemical calculations show that NWA 6234 not only represents a melt composition but is a primitive melt derived from an approximately Fo80 mantle. Thus, NWA 6234 is similar to NWA 5789 and Y 980459 in the sense that all three are olivine‐phyric shergottites and represent primitive magma compositions. However, NWA 6234 is of special significance because it represents the first olivine‐phyric shergottite from a primitive ferroan magma. On the basis of Al/Ti ratio of pyroxenes in NWA 6234, the minor components in olivine and merrillite, and phosphorus zoning of olivine, we infer that the rock crystallized completely at pressures consistent with conditions in Mars' upper crust. The textural intergrowths of the two phosphates (merrillite and apatite) indicate that at a very last stage of crystallization, merrillite reacted with an OH‐Cl‐F‐rich melt to form apatite. As this meteorite crystallized completely at depth and never erupted, it is likely that its apatite compositions represent snapshots of the volatile ratios of the source region without being affected by degassing processes, which contain high OH‐F content.
Fungal encephalitis in human autopsy cases is associated with extensive neuronal damage but only minimal repair
Authors: Tauber Simone C. , Eiffert Helmut , Kellner Silvia , Lugert Raimond , Bunkowski Stephanie , Schütze Sandra , Perske Christina , Brück Wolfgang , Nau Roland
Published: March 2013

Aims

The present study aimed at examining neuronal injury and repair in post mortem brain sections of humans who died from fungal central nervous system infections.

Methods

Histological and immunohistochemical abnormalities in 15 autopsy cases with fungal central nervous system infections from 1990 to 2008 were compared with findings in 10 age‐ und sex‐matched control cases that died from acute non‐neurological causes. The fungal pathogens were identified by culture or polymerase chain reaction and morphology in post mortem tissue. Seven patients with fungal encephalitis had either an organ transplantation or a malignant haematological disorder; five out of 15 did not have a classical predisposing illness but suffered from severe septic infections as the principal cause of immunosuppression, and three from alcoholism.

Results

Fungal organisms detected were Aspergillus spp. and other moulds, Candida spp. and black yeast‐like fungi including Cladosporium spp. Histological analyses identified microglial activation, astrocytosis and axonal injury in the white matter without additional demyelination as characteristic features of this infectious disease. An increased rate of hippocampal neuronal apoptosis was detected in fungal encephalitis, while the number of recently generated TUC‐4 and calretinin‐expressing neurones in the dentate gyrus did not differ between patients and controls.

Conclusions

Unlike in other infectious diseases of the nervous system where a coexistence of damage and repair was observed, fungal encephalitis is characterized by strong damage and minimal neuronal regeneration.
The politics of knowledge: implications for understanding and addressing mental health and illness
Authors: Jenkins Emily K
Published: March 2013

While knowledge represents a valuable commodity, not all forms of knowledge are afforded equal status. The politics of knowledge, which entails the privileging of particular ways of knowing through linkages between the producers of knowledge and other bearers of authority or influence, represents a powerful force driving knowledge development. Within the health research and practice community, biomedical knowledge (i.e. knowledge pertaining to the biological factors influencing health) has been afforded a privileged position, shaping the health research and practice community's view of health, illness and appropriate intervention. The aim of this study is to spark critical reflection and dialogue surrounding the ways in which the politics of knowledge have constrained progress in addressing mental health and illness, one of today's leading public health issues. I argue that the hegemony of biological knowledge represents an ethical issue as it limits the breadth of knowledge available to support practitioners to ‘do good’ in terms of addressing mental illness. Given the power and influence inherent within the nursing community, I propose that nurses ought to engage in critical reflection and action in an effort to better situate the health research and practice community to effectively address the mental health of populations.
Gender differences in cardiac autonomic modulation during medical internship
Authors: Lin Yu‐Hsuan , Chen Ching‐Yen , Lin Sheng‐Hsuan , Liu Chun‐Hao , Weng Wei‐Hung , Kuo Terry B. J. , Yang Cheryl C. H.
Published: March 2013

Medical internship is known to be a time of high stress and long working hours, which increases the risk of depression and cardiovascular disease. Gender differences in medical interns' cardiovascular risk have not been reported previously. Thirty‐eight medical interns (29 males) were repeatedly tested for depressive symptoms using the Hospital Anxiety and Depression Scale and 5‐min spectral analysis of heart rate variability (HRV) at 3‐month intervals during their internship. Among the male interns, the variance of the heart rate decreased at 6, 9, 12 months, and a reduced high frequency, which suggests reduced cardiac parasympathetic modulation, was found at 9 and 12 months into their internship. Increased depressive symptoms were also identified at 12 months in the male group. No significant differences in depression or any of the HRV indices were identified among the female interns during their internship.
Blood Loss and the Need for Transfusion after Shoulder Surface Replacement
Authors: Singh Vinay Kumar , Trehan Ravi , Banerjee Samik , Bardakos Nikolaos V. , Patel Vipul R.
Published: March 2013

Background

Studies on stemmed primary shoulder arthroplasty have shown transfusion rates of up to 38%. The present study aimed to evaluate blood loss and the need for blood transfusion after primary humeral and total shoulder surface replacement.

Materials and methods

Patients undergoing both primary humeral head ( n = 20) and total shoulder ( n = 63) resurfacing were included. The mean drop in haemoglobin levels on the first postoperative day and the need for transfusion were recorded and analyzed against the patient's age, sex, body mass index, American Society of Anesthesiologists grade, type of surgery performed, pre-operative haemoglobin and the use of tranexamic acid.

Results

Only one patient in the entire series (1.2%) required blood transfusion postoperatively, following total shoulder resurfacing. There were statistically significant differences between the two groups with respect to estimated blood loss ( p = 0.005), duration of surgery ( p < 0.0005) and haemoglobin drop ( p < 0.0005), all in favour of the humeral head resurfacing group. The type of surgery was the only independent factor significantly affecting the reduction of haemoglobin levels postoperatively ( p < 0.0005).

Conclusions

Surface replacement of the shoulder appears to be associated with reduced blood loss, leading to a very low need for blood transfusion.
Herbal Extract Decolourization Device Using Activated Carbon
Authors: Liam Chee Teh , Abdul Gaffar Rozilawati , Abdul Majid Fadzilah Adibah , Sarmidi Mohammad Roji
Published: March 2013

Herbal extracts are known for their antioxidant, antimicrobial, and anti–inflammatory properties. However, the intense colour caused by their phenolic content and dark–coloured compounds may spoil the final product’s appearance. To remedy that, this study was undertaken to design a decolourization device to eliminate the intense colour of herbal extracts while retaining their beneficial properties. Batch experiments have been conducted to study decolourization and its effect on extract quality. From there, a decolourization device has been devised using activated carbon. Operating at optimum conditions, the device was able reduce 81 % of the total phenolic content of cashew leaf extracts while retaining 88 % of its radical scavenging capacity. Furthermore, the device is able to re–design the extract’s colour to fulfill the end–user’s needs by manipulating the contact period. The design of this device best fits Langmuir isotherm which demonstrates monolayer coverage of adsorbate at the outer surface of activated carbon.
sbRIO Lab–On–Chip Gas Sensing and Monitoring for Multisensory Array
Authors: Mohamad Tukijan Siti Noradhlia , Abdul Razak Mohd Azhar , Che Harun Fauzan Khairi
Published: March 2013

It is utmost to create a system at which can monitor and indicate the gas level exist in certain area, especially for hazardous gas, as early preparation and protection before something worst happen. The gas sensing and monitoring system composes of hardware and software elements. A spiral chamber which is simplified on chip, known as Lab–On–Chip (LOC), plays an important role in this system. The examined gases will be analysed by 16 sensors during the flow through the spiral chamber. The responses of these sensors are obtained via analogue input channels from single board RIO (sbRIO) and are displayed on a computer using LabVIEW virtual instrument software. The system offers portable, real–time monitoring and fast response time even in room temperature.
Investigation of Combustion and Thermal-Flow Inside a Petroleum Coke Rotary Calcining Kiln With Potential Energy Saving Considerations
Authors: Zhang Zexuan , Wang Ting
Published: March 2013

Calcined coke is a competitive material for making carbon anodes for smelting of alumina to aluminum. Calcining is an energy intensive industry and a significant amount of heat is exhausted in the calcining process. Efficiently managing this energy resource is tied to the profit margin and survivability of a calcining plant. To help improve the energy efficiency and reduce natural gas consumption of the calcining process, a 3D computational model is developed to gain insight of the thermal-flow and combustion behavior in the calciner. Comprehensive models are employed to simulate the moving petcoke bed with a uniform distribution of moisture evaporation, devolatilization, and coke fines entrainment rate with a conjugate radiation-convection-conduction calculation. The following parametric studies are conducted: rotation angles, tertiary air injection angles, devolatilization zone length, discharge end gas extractions without injecting natural gas, variations of coke bed properties (thermal conductivity and heat capacity), and coke bed sliding speed. A total of 19 cases have been simulated. The results of studying the effect of tertiary air injection angles show that employing 15 deg tertiary air injection angle provides the best calcining condition than using 30 deg and 45 deg injection angles by achieving a higher coke bed temperature and less coke fines entrainment and attrition rate. In an attempt to reduce natural gas consumption, employing gas extraction at the discharge end successfully draws the hot combustion gas from the tertiary air zone towards the discharge end without burning natural gas. The coke bed temperature between 6 and 21 m from the discharge end is successfully raised 10–100 K higher, but discharge end temperature is reduced 150 K without burning natural gas. The extracted gas at 1000 K is too low to be returned to the kiln, but it could be used to preheat the tertiary air.
Optimization Design and Analysis of Multilayer Lightweight Thermal Protection Structures Under Aerodynamic Heating Conditions
Authors: Xie Gongnan , Qi Wang , Zhang Weihong , Sunden Bengt , Lorenzini Giulio
Published: March 2013

The purpose of thermal protection system (TPS) is to maintain the structural temperature of the hypersonic aircraft within acceptable limits due to intense aerodynamic heating during reentering earth's atmosphere. In the context of hypersonic aircraft design, a major issue is to obtain the optimal thickness of the insulation layers for TPS. In this study, an idea combining a transient heat transfer model and an efficient optimization model is introduced for multilayer insulation of TPS. The TPS geometric dimensions in the thickness direction are particularly considered as the design variables and the objective function is the total mass of the thermal protection structure with the limitation of the extreme temperatures of the hypersonic aircraft structure. In order to decrease the computational complexity, the globally convergent method of moving asymptotes method is specially used to search the optimal solution. The temperature profiles at various surfaces along the thickness direction are presented and analyzed. It is shown that the usage of multilayer insulation materials for the TPS can save more than 17% weight compared with a single-layer TPS. The detailed analysis and comparison indicate the advantages of the presented optimization model.
Evaluating Risk and Safety Integrity Levels for Pressure Relief Valves Through Probabilistic Modeling
Authors: Mitchell Emily M. , Gross Robert E. , Harris Stephen P.
Published: March 2013

The probability of failure on demand (PFD) for spring-operated pressure relief valves (SORVs) is estimated by applying the Fréchet and Weibull probability distributions using proof test data from the United States Department of Energy's Savannah River Site (SRS) in Aiken, South Carolina. The data can be accessed through the Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD). The probability distributions enable the evaluation of risk, estimation of ANSI/ISA-84.00.01 Safety Integrity Levels (SILs), and the impact of potential modifications of the maintenance plan. Current SRS practices are reviewed, and recommendations are made for risk-based adjustments to the maintenance plan. Subsets of valves are identified in which maintenance times can be extended and in which increased safety margins may be needed.
Life Assessment of Turbine Components Through Experimental and Numerical Investigations
Authors: Hu Dianyin , Wang Rongqiao , Hou Guicang
Published: March 2013

A new lifetime criterion for withdrawal of turbine components from service is developed in this paper based on finite element (FE) analysis and experimental results. Finite element analysis is used to determine stresses in the turbine component during the imposed cyclic loads and analytically predict a fatigue life. Based on the finite element analysis, the critical section is then subjected to a creep-fatigue test, using three groups of full scale turbine components, attached to an actual turbine disc conducted at 750 °C. The experimental data and life prediction results were in good agreement. The creep-fatigue life of this type of turbine component at a 99.87% survival rate is 30 h.
Preliminary Design of a Centrifugal Turbine for Organic Rankine Cycle Applications
Authors: Pini Matteo , Persico Giacomo , Casati Emiliano , Dossena Vincenzo
Published: March 2013

Organic rankine cycles (ORC) are renowned to be attractive energy conversion systems for the thermal energy sources in the small-to-medium power range. A critical component in the ORC technology is the turbo-expander; the difficulties involved in the accurate thermodynamic modeling of organic fluids and, especially, the complex gasdynamic phenomena that are commonly found in ORC turbines may result in relatively low efficiency and in performance reduction at partial loads. In this perspective, a relevant path of development can be outlined in the evaluation of nonconventional turbine architectures, such as the radial-outward or centrifugal turbine. In the present work, a critical evaluation of the feasibility of multistage transonic centrifugal turbines for ORC systems is presented. To support this study, a two-step design procedure, specifically oriented to ORC turbines, was developed. The methodology includes a 1D mean-line code coupled to an external optimizer to perform a preliminary design of the machine. The selected configurations are then verified with a CFD (computational fluid dynamics)-based throughflow solver, able to deal with any flow regime and to treat fluids described by arbitrary equations of state. The overall procedure is applied to the design of two different turbines of the same target power of about 1 MW, the former representing a transonic six-stage turbine and the latter a supersonic three-stage turbine. The two machines are characterized by very different shape and comparable performances. The results are extensively discussed in terms of both overall data and detailed flow fields.
Nonlinear Electrokinetic Transport Under Combined ac and dc Fields in Micro/Nanofluidic Interface Devices
Authors: Nandigana Vishal V. R. , Aluru N. R.
Published: March 2013

The integration of micro/nanofluidic devices led to many interesting phenomena and one of the most important and complex phenomenon among them is concentration polarization. In this paper, we report new physical insights in micro/nanofluidic interface devices on the application of ac and dc electric fields. By performing detailed numerical simulations based on the coupled Poisson, Nernst–Planck, and incompressible Navier–Stokes equations, we discuss electrokinetic transport and other hydrodynamic effects under the application of combined ac and dc electric fields for different nondimensional electrical double layer (EDL) thicknesses and nanochannel wall surface charge densities. We show that for a highly ion-selective nanochannel, the application of the combined ac/dc electric field, at amplitudes greater than the dc voltage and at a low Strouhal number, results in large dual concentration polarization regions (with unequal lengths) at both the micro/nanofluidic interfaces due to large and unequal voltage drops at these junctions. The highly nonlinear potential distribution gives rise to an electric field and body force that changes the electrokinetic fluid velocity from that obtained on the application of only a dc source.
Evaluation of Protective La0.67Sr0.33MnO3–δ Coatings on Various Stainless Steels Used for Solid Oxide Fuel Cell Interconnects
Authors: Huang Jian-Jia , Chu Chun-Lin , Yang Peng , Chang Tien-Chan , Lee Shyong , Yang Jung-Yen
Published: March 2013

Four metallic alloys, namely 2205 duplex stainless steel (2205DSS), ZMG232, and stainless steels SS430 and SS304 are investigated for use as interconnects in solid oxide fuel cells (SOFCs). A La0.67Sr0.33MnO3–δ (LSMO) film is deposited on these metallic-alloy substrates using a pulsed-DC magnetron sputtering system in the reactive mode, leading to the formation of a cubic perovskite structure. The coated alloys are then subjected to oxidizing heat treatments in air at 600 °C, 700 °C, 800 °C, and 900 °C, and their microstructures as well as electrical resistances are evaluated. The electrical resistance measurements are performed at 800 °C, and the area-specific resistance (ASR) of the film-coated 2205DSS alloy is found to be less than that of the uncoated alloy. This is because a thick layer of Cr2O3 and a (Mn, Fe)Cr2O4 spinel phase layer are formed, and some divalent metallic ions migrate into the Cr2O3 layer. It is found that alloys coated with a thin film of LSMO are more suitable for use as metallic interconnects in SOFCs with intermediate-temperature operating ranges.
Segmentation of lung lesions on CT scans using watershed, active contours, and Markov random field
Authors: Tan Yongqiang , Schwartz Lawrence H. , Zhao Binsheng
Published: March 2013

Purpose:

Lung lesions vary considerably in size, density, and shape, and can attach to surrounding anatomic structures such as chest wall or mediastinum. Automatic segmentation of the lesions poses a challenge. This work communicates a new three‐dimensional algorithm for the segmentation of a wide variety of lesions, ranging from tumors found in patients with advanced lung cancer to small nodules detected in lung cancer screening programs.

Methods:

The authors’ algorithm uniquely combines the image processing techniques of marker‐controlled watershed, geometric active contours as well as Markov random field (MRF). The user of the algorithm manually selects a region of interest encompassing the lesion on a single slice and then the watershed method generates an initial surface of the lesion in three dimensions, which is refined by the active geometric contours. MRF improves the segmentation of ground glass opacity portions of part‐solid lesions. The algorithm was tested on an anthropomorphic thorax phantom dataset and two publicly accessible clinical lung datasets. These clinical studies included a same‐day repeat CT (prewalk and postwalk scans were performed within 15 min) dataset containing 32 lung lesions with one radiologist's delineated contours, and the first release of the Lung Image Database Consortium (LIDC) dataset containing 23 lung nodules with 6 radiologists’ delineated contours. The phantom dataset contained 22 phantom nodules of known volumes that were inserted in a phantom thorax.

Results:

For the prewalk scans of the same‐day repeat CT dataset and the LIDC dataset, the mean overlap ratios of lesion volumes generated by the computer algorithm and the radiologist(s) were 69% and 65%, respectively. For the two repeat CT scans, the intra‐class correlation coefficient (ICC) was 0.998, indicating high reliability of the algorithm. The mean relative difference was −3% for the phantom dataset.

Conclusions:

The performance of this new segmentation algorithm in delineating tumor contour and measuring tumor size illustrates its potential clinical value for assisting in noninvasive diagnosis of pulmonary nodules, therapy response assessment, and radiation treatment planning.
Photonic Spin Hall Effect at Metasurfaces
Authors: Yin Xiaobo , Ye Ziliang , Rho Junsuk , Wang Yuan , Zhang Xiang
Published: March 2013

Photonic Spin Hall Effect

When charged carriers move in a magnetic field, they are deflected—an effect known as the Hall effect. Electrons possess charge and spin, a property related to magnetism. The symmetry of electromagnetism then allows for a spin Hall effect whereby the spin is deflected by an electric field. In optics, photons, too, have electric and magnetic components and should thus also exhibit a corresponding photonic spin Hall effect. Using designer metamaterial surfaces,

Yin
et al.

(p.
1405
) show that the spin-orbit coupling for photons can be amplified, giving rise to an observable photonic spin Hall effect.
Zircon U-Pb Geochronology Links the End-Triassic Extinction with the Central Atlantic Magmatic Province
Authors: Blackburn Terrence J. , Olsen Paul E. , Bowring Samuel A. , McLean Noah M. , Kent Dennis V. , Puffer John , McHone Greg , Rasbury E. Troy , Et-Touhami Mohammed
Published: March 2013

Life Versus the Volcanoes

Correlating a specific triggering event, such as an asteroid impact or massive volcanism, to mass extinction events is clouded by the difficulty in precisely timing their occurrence in the geologic record. Based on rock samples collected in North America and Morocco,

Blackburn
et al.

(p.
941
, published online 21 March) acquired accurate ages for events surrounding the mass extinction that occurred ∼201 million years ago, between the Triassic and Jurassic Periods. The timing of the disappearance of marine and land fossils and geochemical evidence of the sequential eruption of the Central Atlantic Magmatic Province imply a strong causal relationship.
The Lost Phone
Taken for Grantedness
The Embedding of Mobile Communication into Society

by Rich Ling

MIT Press, Cambridge, MA, 2012. 255 pp. $34, £23.95. ISBN 9780262018135.
Authors: Bayer Joseph B.
Published: March 2013

Ling considers how the mobile phone has affected our social interactions and how we have come to take it for granted.
Fully Assembled Genome Sequence for Salmonella enterica subsp.
enterica
Serovar Javiana CFSAN001992
Authors: Allard Marc W. , Muruvanda Tim , Strain Errol , Timme Ruth , Luo Yan , Wang Charles , Keys Christine E. , Payne Justin , Cooper Tony , Luong Khai , Song Yi , Chin Chen-Shan , Korlach Jonas , Roberts Rich J. , Evans Peter , Musser Steven M. , Brown Eric W.
Published: March 2013

We report a closed genome of
Salmonella enterica
subsp.
enterica
serovar Javiana (
S
. Javiana). This serotype is a common food-borne pathogen and is often associated with fresh-cut produce. Complete (finished) genome assemblies will support pilot studies testing the utility of next-generation sequencing (NGS) technologies in public health laboratories.
Genome of the Haloarchaeon Natronomonas moolapensis, a Neutrophilic Member of a Previously Haloalkaliphilic Genus
Authors: Dyall-Smith Mike L. , Pfeiffer Friedhelm , Oberwinkler Tanja , Klee Kathrin , Rampp Markus , Palm Peter , Gross Karin , Schuster Stephan C. , Oesterhelt Dieter
Published: March 2013

The genus
Natronomonas
contains two species, one haloalkaliphile (
N. pharaonis
) and one neutrophile (
N. moolapensis
). Here, we report the genome sequence of
N. moolapensis
strain 8.8.11. The overall genome properties are similar for the two species. Only the neutrophile contains bacteriorhodopsin and a membrane glycolipid.
Evaluation of a Modular Multiplex-PCR Methicillin-Resistant Staphylococcus aureus Detection Assay Adapted formecCDetection
Authors: Becker Karsten , Larsen Anders R. , Skov Robert L. , Paterson Gavin K. , Holmes Mark A. , Sabat Artur J. , Friedrich Alexander W. , Köck Robin , Peters Georg , Kriegeskorte André
Published: March 2013

AmecC(mecALGA251)-adapted multiplex PCR-based methicillin-resistantStaphylococcus aureus(MRSA) detection assay was evaluated using an international,spa-typedStaphylococcus aureuscollection comprising 51mecC-positive MRSA, 240mecA-positive MRSA, and 50mecA- andmecC-negative methicillin-susceptibleS. aureus(MSSA) isolates. The assay showed 100% sensitivity and specificity forS. aureusspecies identification as well as formecAandmecCdetection.
Cache Valley Virus in a Patient Diagnosed with Aseptic Meningitis
Authors: Nguyen Nang L. , Zhao Guoyan , Hull Rene , Shelly Mark A. , Wong Susan J. , Wu Guang , St. George Kirsten , Wang David , Menegus Marilyn A.
Published: March 2013

Cache Valley virus was initially isolated from mosquitoes and had been linked to central nervous system-associated diseases. A case of Cache Valley virus infection is described. The virus was cultured from a patient's cerebrospinal fluid and identified with real-time reverse transcription-PCR and sequencing, which also yielded the complete viral coding sequences.
Molecular Characterization of Extraintestinal Escherichia coli Isolates in Japan: Relationship between Sequence Types and Mutation Patterns of Quinolone Resistance-Determining Regions Analyzed by Pyrosequencing
Authors: Aoike Nozomi , Saga Tomoo , Sakata Ryuji , Yoshizumi Ayumi , Kimura Soichiro , Iwata Morihiro , Yoshizawa Sadako , Sugasawa Yasuyuki , Ishii Yoshikazu , Yamaguchi Keizo , Tateda Kazuhiro
Published: March 2013

Infection from fluoroquinolone-resistant
Enterobacteriaceae
is an increasing health problem worldwide. In the present study, we developed a pyrosequencing-based high-throughput method for analyzing the nucleotide sequence of the quinolone resistance-determining regions (QRDRs) of
gyrA
and
parC
. By using this method, we successfully determined the QRDR sequences of 139 out of 140 clinical
Escherichia coli
isolates, 28% of which were nonsusceptible to ciprofloxacin. Sequence results obtained by the pyrosequencing method were in complete agreement with those obtained by the Sanger method. All fluoroquinolone-resistant isolates (
n
= 35; 25%) contained mutations leading to three or four amino acid substitutions in the QRDRs. In contrast, all isolates lacking a mutation in the QRDR (
n
= 81; 57%) were susceptible to ciprofloxacin, levofloxacin, and nalidixic acid. The
qnr
determinants, namely, the
qnrA
,
qnrB
, and
qnrS
genes, were not detected in the isolates, and the
aac(6
′
)-Ib-cr
gene was detected in 2 (1.4%) of the isolates. Multilocus sequence typing of 34 randomly selected isolates revealed that sequence type 131 (ST131) (
n
= 7; 20%) is the most prevalent lineage and is significantly resistant to quinolones (
P
< 0.01). The genetic background of quinolone-susceptible isolates seemed more diverse, and interestingly, neighboring STs of ST131 in the phylogenetic tree were all susceptible to ciprofloxacin. In conclusion, our investigation reveals the relationship between fluoroquinolone resistance caused by mutations of QRDRs and the population structure of clinical extraintestinal
E. coli
isolates. This high-throughput method for analyzing QRDR mutations by pyrosequencing is a powerful tool for epidemiological studies of fluoroquinolone resistance in bacteria.
Broad-Range Direct Detection and Identification of Fungi by Use of the PLEX-ID PCR-Electrospray Ionization Mass Spectrometry (ESI-MS) System
Authors: Simner Patricia J. , Uhl James R. , Hall Leslie , Weber Michelle M. , Walchak Robert C. , Buckwalter Seanne , Wengenack Nancy L.
Published: March 2013

The PLEX-ID system is a novel technology that couples PCR amplification and electrospray ionization-mass spectrometry to identify pathogens directly in clinical specimens. The analytical performance of the PLEX-ID Broad Fungal assay was compared with that of traditional culture identification by using 91 characterized fungal culture isolates (64 manufacturer-claimed and 27 nonclaimed organisms) and directly by using 395 respiratory specimens. Discordant results were resolved by D2 large-subunit ribosomal DNA fungal sequencing. Environmental studies were performed to monitor for potential contamination. The PLEX-ID Broad Fungal assay correctly identified 95.6% (87/91) and 81.3% (74/91) of the culture isolates to the genus and species levels, respectively. Of the manufacturer-claimed organisms, 100% (64/64) and 92.2% (59/64) were correctly identified to the genus and species levels, respectively. Direct analysis of respiratory specimens resulted in 67.6% (267/395) and 66.6% (263/395) agreement with culture results to the genus and species levels, respectively, with 16.2% (64/395) of the results discordant with culture and 16.2% (64/395) not detected by the system. The majority (>95%) of the isolates not detected directly by the PLEX-ID system ultimately grew in low quantities in culture (≤20 colonies). In 20.3% (35/172) of the respiratory specimens where no growth was observed in culture, the PLEX-ID system identified a fungus, suggesting a potential increase in sensitivity over culture in some instances. The PLEX-ID system provides a rapid method for the detection of a broad array of fungi directly in respiratory specimens and has the potential of impacting turnaround times and patient care by reducing the need to wait for the growth of an organism in culture.
The use of biomarkers in neuroendocrine tumours
Authors: Khan Mohid Shakil , Caplin Martyn E
Published: March 2013

The incidence and prevalence of neuroendocrine tumours (NETs) arising from the gastrointestinal tract are increasing. At the time of diagnosis, histological grade, based on Ki-67 proliferation index on a tumour biopsy or specimen, offers prognostication but with often lengthy survival, this may not reflect current tumour biology later in the disease course. Biomarkers, including plasma chromogranin A, urinary 5-hydroxyindole acetic acid and pancreatic specific hormones (insulin, gastrin, vasoactive intestinal peptide), have a role in diagnosis but despite being incorporated into routine clinical practice, there is a lack of robust prospectively collected data investigating their prognostic and predictive value. Given the increasing number of treatment options available for NETs and prolonged survival, there is no agreement on the order of treatment for individual NET patients but the emergence of novel biomarkers and validation of existing ones, in addition to better understanding of the molecular biology, may help solve this clinical problem.