bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of de-escalation therapy on clinical outcomes for intensive care unit-acquired pneumonia
Authors: Joung Kyong Mi , Lee Jeong-a , Moon Soo-youn , Cheong Hae Suk , Joo Eun-Jeong , Ha Young-Eun , Sohn Kyung Mok , Chung Seung Min , Suh Gee Young , Chung Doo Ryeon , Song Jae-Hoon , Peck Kyong Ran
Published: March 2011

Introduction

De-escalation therapy is a strategy currently used for the management of nosocomial pneumonia. In this study, we evaluated clinical outcomes and risk factors related to de-escalation therapy in patients with intensive care unit (ICU)-acquired pneumonia.

Methods

This was a retrospective observational cohort study of ICU patients who developed pneumonia more than 48 hours after admission to the ICU at Samsung Medical Center from September 2004 to December 2007.

Results

The 137 patients comprised 44 (32.1%) who received de-escalation therapy and 93 in the non-de-escalation group. The de-escalation group showed a lower pneumonia-related mortality rate than the non-de-escalation group by day 14 (2.3% vs. 10.8%, respectively; P = 0.08) and by day 30 (2.3% vs. 14%, respectively; P = 0.03) after the diagnosis of pneumonia. The variables independently associated with ICU-acquired pneumonia-related mortality included the Acute Physiology and Chronic Health Evaluation II (APACHE II) score and the modified Clinical Pulmonary Infection Score (CPIS) after 5 days with pneumonia. The non-de-escalation group had significantly higher APACHE II score and modified CPIS after 5 days with ICU-acquired pneumonia compared to the de-escalation group. Among all patients, 20.4% (28 of 137) had negative cultures for pathogens, and 42.9% (12 of 28) received de-escalation therapy. The latter 12 patients received de-escalation therapy and survived 30 days after the diagnosis of pneumonia.

Conclusions

Patients in the de-escalation group showed a significantly lower mortality rate compared to patients in the non-de-escalation group. De-escalation therapy can be safely provided to patients with ICU-acquired pneumonia if they are clinically stable by day 5, even in those whose respiratory specimen cultures yield no specific pathogens.
Calcium/calmodulin-dependent protein kinase (CaMK) Iα mediates the macrophage inflammatory response to sepsis
Authors: Zhang Xianghong , Guo Lanping , Collage Richard D , Stripay Jennifer L , Tsung Allan , Lee Janet S , Rosengart Matthew R
Published: March 2011

Dysregulated Ca2+ handling is prevalent during sepsis and postulated to perpetuate the aberrant inflammation underlying subsequent organ dysfunction and death. The signal transduction cascades mediating these processes are unknown. Here, we identify that CaMKIα mediates the Mφ response to LPS in vitro and the inflammation and organ dysfunction of sepsis in vivo. We show that LPS induced active pThr177-CaMKIα in RAW 264.7 cells and murine peritoneal Mφ, which if inhibited biochemically with STO609 (CaMKK inhibitor) or by RNAi, reduces LPS-induced production of IL-10. Transfection of constitutively active CaMKIα (CaMKI293), but not a kinase-deficient mutant (CaMKI293K49A), induces IL-10 release. This production of IL-10 is mediated by CaMKIα-dependent regulation of p38 MAPK activation. CaMKIα activity also mediates the cellular release of HMGB1 by colocalizing with and regulating the packaging of HMGB1 into secretory lysosomes. During endotoxemia, mice receiving in vivo CaMKIαRNAi display reduced systemic concentrations of IL-10 and HMGB1 in comparison with mice receiving NTRNAi. These data support the biological relevance of CaMKIα-dependent IL-10 production and HMGB1 secretion. In a CLP model of sepsis, CaMKIαRNAi mice display reduced systemic concentrations of IL-10, IL-6, TNF-α, and HMGB1 in comparison with NTRNAi mice, which correlate with reductions in the development of renal dysfunction. These data support that CaMKIα signaling is integral to the Mφ responding to LPS and may also be operant in vivo in regulating the inflammation and organ dysfunction consequent to sepsis.
The 2D coastal effect on marine time domain electromagnetic measurements using broadside dBz/dt of an electrical transmitter dipole
Authors: Goldman Mark , Levi Eldad , Tezkan Buelent , Yogeshwar Pritam
Published: March 2011

Galvanic transmitter-receiver arrays commonly are used in marine controlled-source electromagnetic (CSEM) exploration of electrically resistive targets such as hydrocarbons, gas hydrates, etc. These arrays utilize vertical electric currents and, as a result, are expected to provide better resolving capability for exploring subhorizontal resistive structures than arrays including horizontal coils. If, however, a subseafloor resistive target is located within a transition zone at distances of up to a few kilometers from the shoreline, the 2D sea-coast resistivity contrast significantly affects the resolving capability of the measurements. An extensive multidimensional modeling supported by numerous offshore measurements showed that the inductive array consisting of a horizontal electric dipole transmitter and a broadside vertical magnetic dipole (horizontal coil) receiver exhibits much better resolving power in time domain compared to all other arrays but those with a vertical electric dipole. This effect takes place only if a short offset receiver coil is located between the transmitter dipole and the coast. If the coil is located at the seaside of the transmitter dipole, the signal lacks the resolving capability almost entirely. At large offsets, the resolving capability of the measurements is relatively low at both sides of the transmitter dipole. Although actual field measurements were conducted only to explore a shallow target (fresh subseafloor groundwater body), calculations show that the same phenomenon exists in case of deep targets (e.g., hydrocarbons).
Frequency-domain reverse-time migration with source estimation
Authors: Kim Youngseo , Min Dong-Joo , Shin Changsoo
Published: March 2011

Although artificially generated seismic sources such as dynamite, vibroseis, and air guns are used in seismic exploration, it is not easy to exactly recover the source wavelet in field recording or in data processing. For this reason, seismic data processing often assumes that an explosive-source wavelet can be described by a well-known function (e.g., a Ricker wavelet), a near-offset trace, or a deconvolved wavelet. In frequency-domain waveform inversion, it has been proven that a source wavelet can be estimated by an optimization method, and incorporating the source wavelet estimation into an inversion algorithm yields better inversion results. We have developed source wavelet estimation into 2D two-way frequency-domain reverse-time migration. The source wavelet is first estimated independently of reverse-time migration by an optimization method such as the full Newton method. It is then used in reverse-time migration. This source-wavelet-incorporated reverse-time migration algorithm is applied to three model data sets: a simple anticline model, the Institut Français du Petrole (IFP) Marmousi model, and the BP 2004 EAGE model. Numerical examples were used to show that better migration images can be obtained by using an estimated source wavelet than those obtained by using a designatured wavelet without source estimation. To enhance the migrated images, the Laplacian filter is applied and migrated images are scaled using the diagonal of the pseudo-Hessian matrix. It is expected that the source wavelet estimation method can be directly applied to 2D or 3D time-domain two-way reverse-time migration.
Odd–Even Effect and Unusual Behavior of Dodecyl-Substituted Analogue Observed in the Crystal Structure of Alkyltrimethylammonium–[Ni(dmit)2]− Salts
Authors: Dai Kotaro , Nomoto Kuniharu , Ueno Shinji , Tomono Kazuaki , Miyamura Kazuo
Published: March 2011

A series of [Ni(dmit)2]− (dmit: 1,3-dithiole-2-thione-4,5-dithiolato) salts of alkyltrimethylammonium (Cn: n represents the alkyl chain length; n = 3 and 5–18) have been prepared and analyzed by X-ray structural analysis. All complex salts have been found to be composed of alternate sheets of [Ni(dmit)2]− anions and sheets of cations with a pronounced interdigitation of the alkyl chains. However, molecular arrangement differed between (C3)[Ni(dmit)2] and other (Cn)[Ni(dmit)2] (n = 5–18). Adjacent cations were aligned along the long axis of [Ni(dmit)2]− anion in C3 complex salt, while in others (C5–C18 complex salts), they were aligned toward the short axis. Such a difference in arrangement arose from correlativity between the lengths of the long axis of cation and anion, namely CLCA. Furthermore, relative orientation between the alkyl chain of cation and [Ni(dmit)2]− anion differed between the odd- and even-numbered cations for C10–C18. Whereas the plane of alkyl chain for odd-numbered cation was normal to the plane of [Ni(dmit)2]− anion, that of even-numbered cation was parallel. It was also found that C12 analog behaved like odd-numbered cations. However, in C12 salt, the end methyl group of the dodecyl group adopted unusual end-gauche conformation.
Stacking interactions in PUF–RNA complexes
Authors: Koh Yvonne Yiling , Wang Yeming , Qiu Chen , Opperman Laura , Gross Leah , Tanaka Hall Traci M. , Wickens Marvin
Published: March 2011

Stacking interactions between amino acids and bases are common in RNA–protein interactions. Many proteins that regulate mRNAs interact with single-stranded RNA elements in the 3′ UTR (3′-untranslated region) of their targets. PUF proteins are exemplary. Here we focus on complexes formed between a Caenorhabditis elegans PUF protein, FBF, and its cognate RNAs. Stacking interactions are particularly prominent and involve every RNA base in the recognition element. To assess the contribution of stacking interactions to formation of the RNA–protein complex, we combine in vivo selection experiments with site-directed mutagenesis, biochemistry, and structural analysis. Our results reveal that the identities of stacking amino acids in FBF affect both the affinity and specificity of the RNA–protein interaction. Substitutions in amino acid side chains can restrict or broaden RNA specificity. We conclude that the identities of stacking residues are important in achieving the natural specificities of PUF proteins. Similarly, in PUF proteins engineered to bind new RNA sequences, the identity of stacking residues may contribute to “target” versus “off-target” interactions, and thus be an important consideration in the design of proteins with new specificities.
A Volume of Fluid Phase Change Model on Adaptive Octree Grids
Authors: Akhtar Mohammad W. , Kleis Stanley J.
Published: March 2011

A three-dimensional phase change model using finite volume has been developed. Interface thermal conditions that are consistent with the mixture formulation within the volume tracking framework are introduced. The computational grid is dynamically adapted near the interface using an octree based structure. Up to three levels of adaption are used to provide improved accuracy in regions of steep gradients of flow variables near the liquid-vapor interface at a reduced computational cost. Interface jump conditions are imposed by specifying mass, momentum, and energy sources for the mixture variables in the interface cells. Second order accurate liquid and vapor temperature gradients at cell faces are calculated based on the location and orientation of the interface (sharp interface approach). These estimates are then used to calculate the mass source terms, which are distributed in the interface cells consistent with the mixture formulation. Such an approach maintains the interface at saturation while the mixture temperatures of the liquid and vapor in the interface cells can be superheated. A one-dimensional cavity flow problem is used to test for the proper coupling of vapor generation rate with energy and momentum flux effects. Three-dimensional bubble growth rates at 5°C uniform superheat (Ja=8.6, density ratio ∼140, and conductivity ratio ∼2.3) of refrigerant FC-87 are compared with theory in the diffusion controlled regime. The analytical solution of Mikic et al. for bubble radius as a function of time with a non-zero initial radius is used to validate the numerical solution. The numerical solution is validated against theoretical prediction of bubble radius as a function of time for a more complete validation of the balances of mass, momentum, and energy at the liquid-vapor interface.
Experimental Investigation of Irradiation Creep and Growth of Recrystallized Zircaloy-4 Guide Tubes Pre-Irradiated in PWR
Authors: McGrath Margaret A. , Yagnik Suresh
Published: March 2011

Re-crystallized Zircaloy-4 guide tubes were irradiated in commercial pressurized water reactors (PWRs) at three different temperatures to fluences near 1×1022 n/cm2 E>1 MeV (15 displacements per atom), resulting in moderate corrosion and three different hydrogen contents (approximately 135, 240, and 700 parts per million). Sections of the guide tubes were re-irradiated in the Halden reactor to assess the irradiation creep and growth behaviors. Three conditions were applied: Bellows-loaded axial compression creep; zero stress growth; and zero stress, zero flux (control specimens). The guide tube sections were re-irradiated under simulated PWR conditions by utilizing a pressurized light water loop operating with normal PWR water chemistry at approximately 320°C. Axial length changes were measured in-reactor by linear variable differential transformers (LVDTs), and post-irradiation hot cell measurements were done to confirm the LVDT elongation measurements. After minor corrections were made to account for reactor testing variables, it was shown that the LVDT measurements were accurate, thus creep and growth or free growth rates were established for each guide tube section. Hot cell examinations were also performed to establish the state of corrosion of each specimen, including hydrogen content, both before and after the re-irradiation in the Halden reactor. The results showed that stress free irradiation growth was different for each specimen and correlated qualitatively with the hydrogen content and commercial irradiation temperatures of the guide tubes. The higher hydrogen content, or higher commercial irradiation temperature, gave rise to higher subsequent growth rates. After subtracting the growth strain from the measured creep and growth strain values, the magnitude of creep and creep rates were essentially the same for all specimens: No effect of commercial reactor irradiation temperature or hydrogen content was observed. The results give important new data on irradiation creep and growth and on the correlation between hydrogen content and irradiation temperature on growth rates.
Abstentions in the German Bundesrat and ternary decision rules in weighted voting systems
Authors: Birkmeier Olga , Käufl Andreas , Pukelsheim Friedrich
Published: March 2011

Ternary decision rules allowing for abstentions,besides Yea- and Nay-votes, are analyzed. The German Bundesrat serves as a prime example. We show that the decision-making efficiency of the Bundesrat would increase if abstentions were allowed. A general formula for the mean success margin of a ternary decision rule is derived assuming selfdual and permutationally invariant distributions. The ternary Penrose–Banzhaf model is discussed in detail, and the influence probabilities of voters and a rule´s influence sensitivity are evaluated.
Robust replication in H-self-similar Gaussian market models under uncertainty
Authors: Gapeev Pavel V. , Sottinen Tommi , Valkeila Esko
Published: March 2011

We consider the robust hedging problem in the framework of model uncertainty, where the log-returns of the stock price are Gaussian and H-self-similar with H∈(1/2,1). These assumptions lead to two natural but mutually exclusive hypotheses, both being self-contained to fix the probabilistic model for the stock price. Namely, the investor may assume that either the market is efficient, that is the stock price process is a continuous semimartingale, or that the centred log-returns have stationary distributions. We show that to be able to super-hedge a European contingent claim with a convex payoff robustly, the investor must assume that the markets are efficient. If it turns out that the stationarity hypothesis is true, then the investor can actually super-hedge the option and thereby receive some net profit.
A note on moment convergence of bootstrap M-estimators
Authors: Kato Kengo
Published: March 2011

This paper studies the consistency of bootstrap moment estimators for a general M-estimator. We establish a theorem on the uniform integrability of the bootstrap M-estimator, thereby giving sufficient conditions for the consistency of the bootstrap moment estimators. As an application of our theorem, we provide sufficient conditions for the consistency of the bootstrap variance estimator for the quantile regression estimator, which has been considered as an important unsolved problem in the literature. We also discuss a justification of a bootstrap information criterion.
GLP-1 and exendin-4 can reverse hyperlipidic-related osteopenia
Authors: Nuche-Berenguer Bernardo , Lozano Daniel , Gutiérrez-Rojas Irene , Moreno Paola , Mariñoso María L , Esbrit Pedro , Villanueva-Peñacarrillo María L
Published: March 2011

Increased fat mass contributes to bone deterioration. Glucagon-like peptide 1 (GLP-1) and its related peptide exendin 1–39 amide (Ex-4), two lipid-lowering peptides, exert osteogenic effects in diabetic states. We examined the actions of 3-day administration of GLP-1 or Ex-4 on bone remodeling markers and on bone mass and structure in hyperlipidic (HL) and hypercaloric rats. Wistar rats on a hyperlipidemic diet for 35 days were subcutaneously administered GLP-1 (0.86 nmol/kg per h), Ex-4 (0.1 nmol/kg per h), or saline (control) by continuous infusion for 3 days. After killing, tibiae were removed for total RNA and protein isolation, as well as femurs and L1–L4 vertebrae for bone mass and quality assessment. Body weight and plasma insulin were unaltered in HL rats, which showed osteopenia (by dual-energy X-ray absorptiometry), associated with hyperglycemia, hypertriglyceridemia, and hypercholesterolemia. GLP-1 or Ex-4 administration decreased the levels of glucose, triglycerides, and total cholesterol in plasma but increased osteocalcin (OC) gene expression and the osteoprotegerin (OPG)/receptor activator of NF-κB ligand (RANKL) ratio – at the expense of an augmented OPG – above corresponding control values in the tibia. Each tested peptide similarly reversed the decreased femoral and vertebral bone mass in these rats, whereas the deteriorated trabecular structure in the vertebrae improved associated with normalization of bone remodeling. These findings demonstrate that GLP-1 and Ex-4 are similarly efficient in reversing the bone alterations in this HL rat model, which has proven to be useful for studying the fat–bone relationships.
Juízo e ação moral: desafios teóricos em psicologia
Authors: Souza Leonardo Lemos de , Vasconcelos Mario Sergio
Published: March 2011

O presente artigo apresenta e discute a polêmica, no campo da psicologia moral, sobre as relações entre juízo e ação. Teorias de tradição racionalista e estruturalista, como as de Piaget e Kohlberg, afirmam uma relação de continuidade entre juízo e ação moral e, ao mesmo tempo, lançam pontos de discussão sobre a complexidade envolvida no tema. Por outro lado, novas frentes de trabalho sugerem a integração de outros elementos (a cultura, a afetividade e o self), além das estruturas que podem compor um referencial com o qual se evidenciem as relações entre os aspectos envolvidos nas condutas morais. Por fim, apesar das críticas acenarem com caminhos promissores na pesquisa sobre o juízo e a ação moral, ainda existem limites na construção de referenciais teóricos e metodológicos que articulem diferentes perspectivas de análise psicológica da moralidade.
Surface vortex prevention at power intakes by horizontal plates
Authors: Amiri S. Mahdi , Zarrati Amir Reza , Roshan Reza , Sarkardeh Hamed
Published: March 2011

The efficiency of horizontal perforated and solid plates, installed on top of an intake for prevention of surface vortex formation, was experimentally investigated. The experiments were conducted on a horizontal intake of a reservoir. By changing the angle of the approach flow, submergence of the intake and the discharge, 36 air-core surface vortices with different strengths were generated. The strengths of these vortices were evaluated by measuring tangential velocities using an acoustic Doppler velocimeter. A relationship between the strength of the surface vortex and the necessary percentage of uniform opening of the perforated plate is presented. It was found that a perforated plate of width 1D and 1·5D length normal to the intake (D is the tunnel diameter) with 50% uniform opening and a solid plate of 1·5D width and 2D length eliminated all surface vortices at the intake. Pressure was also measured in a section immediately downstream of the intake by means of four transducers. By using the measured pressure values, the effect of anti-vortex plates on local loss at the intake was determined.
Performance of a novel hybrid algorithm in the design of water networks
Authors: Ghajarnia Navid , Bozorg Haddad Omid , Mariño Miguel A.
Published: March 2011

This paper proposes a novel hybrid evolutionary-based approach, named the modified cellular automaton network design algorithm–honey-bee mating optimisation (Mcanda–HBMO) algorithm, to the optimal design of water distribution systems. HBMO is a meta-heuristic approach for solving discrete and continuous optimisation problems, and Mcanda is a powerful local search algorithm that can help HBMO in better evolution. Two benchmark water distribution networks are considered in which the design variables are pipe diameters. Subsequently, the HBMO algorithm is applied to determine optimal discrete and continuous pipe sizes for the networks. Furthermore, to determine the effects of the roughness coefficient and minimum required nodal pressure on the HBMO algorithm performance, some additional information is presented to demonstrate those influences in the value of the final objective function as well as optimal pipe diameters. Moreover, in order to improve the performance of the search method, a combination of a local search algorithm with HBMO is tested in both examples. The hybrid algorithm consists of the modified Canda algorithm and pure HBMO which has had a better performance in both convergence rate and average objective functions found. The final results yielded by both HBMO and hybrid Mcanda–HBMO show the capability of these algorithms and also present some improvements in previously reported results.
Optimum operation of wells in coastal aquifers
Authors: Haddad Omid Bozorg , Mariño Miguel A.
Published: March 2011

The combination of two powerful analysis techniques, simulation and optimisation, produces an engineering design tool that can aid in the formulation of design criteria and assist decision makers in assessing the impacts of design trade-offs. This paper presents a management model with the economic objective of maximising the net benefit derived from a pumped freshwater volume while eliminating the utility cost in coastal aquifers threatened by saltwater intrusion. Because the search space is both discontinuous and extremely wide, and also contains numerous local minima, evolutionary algorithms can be helpful in the search for near-optimal solutions. In this paper, a simulation model of the sharp saltwater–freshwater interface is considered to be time-independent. Moreover, the honey-bee mating optimisation (HBMO) algorithm is applied to a test case and the results are compared with those of a previously developed genetic algorithm (GA) for the same case. The comparison indicates that the HBMO algorithm can be effectively used to obtain near-global optimal solutions for the problem under consideration. The HBMO algorithm is then applied to the management of the coastal aquifer underlying the city of Miami Beach in northeastern Spain. Compared with the GA, the HBMO algorithm results show a significantly better performance and advantages in terms of both the final objective function value (more benefit) obtained and total pumped discharge from the system. Furthermore, the efficiency of the HBMO algorithm in handling non-linear discontinuous groundwater simulation/optimisation problems much more quickly than the GA is a promising point for further use of the algorithm in the field of groundwater optimisation.
Long-term efficiency of water networks with demand uncertainty
Authors: Seifollahi-Aghmiuni Samaneh , Haddad Omid Bozorg , Omid Mohammad H. , Mariño Miguel A.
Published: March 2011

Water distribution network (WDN) design problems generally consider minimising network costs while meeting minimum allowable pressure under specified demand patterns. However, extension and renovation of networks based on assessment of demand uncertainty causes an increase in efficiency of the system and monetary savings. Attention to uncertain changes in pattern and the value of nodal demands in an operational period can thus show the effect of uncertainties in the network's efficiency. Using Monte Carlo simulation and shuffled frog leaping algorithm optimisation, this paper analyses the efficiency of a designed network based on nodal demand uncertainty during the operational period. Assessment of a network efficiency index according to a probabilistic normal distribution for nodal demand in an operational period shows that a network design that does not consider nodal demand uncertainty decreases network efficiency, especially at the end of the operational period. Moreover, an increase in demand uncertainty decreases network efficiency. The results of the proposed model for a benchmark WDN show that a network designed deterministically for a 30-year operational period is unable to secure nodal demands with suitable pressure after 10 years. In addition, the minimum required pressure considered in network design is met in approximately the first 18 years of the operational period.
Costing improved water supply systems for developing countries
Authors: Carlevaro Fabrizio , Gonzalez Cristian
Published: March 2011

The aim of this paper is to present a practical manual prepared for the World Health Organization (WHO) on how to identify, collect, estimate and compare costs of the available technical options to provide access to safe drinking water in low-income communities. In order to cost – from a social point of view – an improved water supply technology that is likely to secure access to safe drinking water (as defined by the WHO–Unicef joint monitoring programme for water supply and sanitation), an analytical approach is used that disaggregates the technology process according to its essential components, singled out by an engineering description. Questionnaires were developed to identify the main resources invested in a water supply project and to collect, at different disaggregation levels, four types of costs: investment, operation, maintenance and other relevant costs (e.g. administration). Comparability of these different cost elements is achieved by discounting expenditures at different times to the same reference time. Full and unit cost indicators that allow a least-cost analysis can then be derived from this cost picture. To successfully apply the method to actual projects, a spreadsheet was developed using Microsoft Excel to enable user-friendly implementation of all the costing tasks.
Optimal design and operation of pumping stations using NLP-GA
Authors: Rasoulzadeh-Gharibdousti Solmaz , Bozorg Haddad Omid , Mariño Miguel A.
Published: March 2011

This paper addresses the optimal design and operation of an irrigation pumping station system using hybrid non-linear programming and a genetic algorithm (NLP-GA), and evaluates the algorithm in a practical problem. Results of the NLP-GA are compared with existing optimisation approaches to solve the same problem. The analytical approaches considered are the Lagrange multiplier method, a genetic algorithm and the honey-bee mating optimisation algorithm. The Lagrange multiplier method, genetic algorithm, honey-bee mating optimisation and the NLP-GA hybrid are used to simultaneously optimise the minimum annualised investment cost of the pumping station and its annual operating cost. The solution includes selection of pump type, capacity, number of units and scheduling of pump operation. The hybrid algorithm takes advantage of the high speed of NLP as well as the intelligent searching of evolutionary algorithms to overcome the shortcomings of individual NLP and genetic algorithm methods such as trapping of local optima, reporting only local or near-global optimal solutions and the low convergence rate of evolutionary algorithms in this type of problem. The results highlight the advantages in design, effective operation and ease of the NLP-GA method for solving complex problems of the type considered here. Although the NLP-GA converges rapidly, the results are promising and compare well with those of the Lagrange multiplier method, the genetic algorithm and honey-bee mating optimisation.
Low Physical Activity and Risk of Cardiovascular and All-Cause Mortality in Renal Transplant Recipients
Authors: Zelle Dorien M. , Corpeleijn Eva , Stolk Ronald P. , de Greef Mathieu H.G. , Gans Rijk O.B. , van der Heide Jaap J. Homan , Navis Gerjan , Bakker Stephan J.L.
Published: March 2011

Background and objectives

Low physical activity (PA) is a risk factor for mortality in the general population. This is largely unexplored in renal transplant recipients (RTRs). We studied whether PA is associated with cardiovascular and all-cause mortality in a prospective cohort of RTR.

Design, setting, participants, & measurements

Between 2001 and 2003, 540 RTRs were studied (age, 51 ± 12 years; 54% male). PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire). Cardiovascular and all-cause mortality were recorded until August 2007.

Results

Independent of age, PA was inversely associated with metabolic syndrome, history of cardiovascular disease, fasting insulin, and triglyceride concentration, and positively associated with kidney function and 24-hour urinary creatinine excretion (i.e., muscle mass). During follow-up for 5.3 years (range, 4.7 to 5.7 years), 81 RTRs died, with 37 cardiovascular deaths. Cardiovascular mortality was 11.7, 7.2, and 1.7%, respectively, according to gender-stratified tertiles of PA (P = 0.001). All-cause mortality was 24.4, 15.0, and 5.6% according to these tertiles (P < 0.001). In Cox regression analyses, adjustment for potential confounders including history of cardiovascular disease, muscle mass, and traditional risk factors for cardiovascular disease did not materially change these associations.

Conclusions

Low PA is strongly associated with increased risk for cardiovascular and all-cause mortality in RTRs. Intervention studies are necessary to investigate whether PA improves long-term survival after renal transplantation.
Chemical investigation of the essential oil of Laggera crispata (Vahl) Hepper & Wood from India
Authors: Verma Ram , Padalia Rajendra , Chanotiya Chandan , Chauhan Amit , Yadav Anju
Published: March 2011

Hydrodistilled essential oil of the aerial parts of Laggera crispata (Vahl)
Hepper & Wood, collected from the Kumaon region of the western Himalayas was
analysed by gas chromatography and gas chromatography-Mass Spectrometry.
Eighty constituents, accounting for 83.9 % of the total oil composition, were
identified. The oil was mainly dominated by sesquiterpenoids (45.3 %) and
benzenoid compounds (33.9 %). Among them, 2,5-dimethoxy-p-cymene (32.2 %),
10-epi-?-eudesmol (14.7 %), ?-caryophyllene (6.9 %), and caryophyllene oxide
(5.4 %) were major components of the oil.
A Commentary on Declining Maternal Mortality in Nepal
Authors: Thapa Rita
Published: March 2011

DOI: 10.3126/hren.v9i1.4352Health Renaissance, 2011: Vol.9 No.1:1-2
Intestinal infection with multiple parasites including Balantidium coli
Authors: Poudyal N , Baral R , Gyawali N , Gurung R , Amatya R
Published: March 2011

Balantidium coli is only parasitic ciliate and infrequent pathogen for human beings. The infection fundamentally affects the colon and causes variable clinical pictures, from asymptomatic to serious dysenteric forms. We present a case of diarrhea and abdominal discomfort with multiple parasites including B. coli in a patient from Sunsari, Nepal. DOI: 10.3126/hren.v9i1.4362Health Renaissance, 2011: Vol.9 No.1:45-46
A case of colonic gallstone ileus with a spontaneous evacuation
Authors: Bajracharya A , Pathania OP , Adhikary S , Agrawal CS
Published: March 2011

Colonic gallstone is an uncommon entity with a high morbidity and mortality due to various reasons. It remains a diagnostic challenge because of delayed and non-specific presentations, especially in the elderly population, often with multiple co-morbidities. We present a case of colonic gallstone ileus with spontaneous evacuation in a 67 years female who had a threeday history of intermittent bouts of colicky abdominal pain, vomiting , constipation and progressive abdominal distension, features of large bowel obstruction treated non operatively for 72 hours and passage of the stone spontaneously. Keywords: gallstone ileus; large bowel obstruction; colonic gallstone DOI: 10.3126/hren.v9i1.4363Health Renaissance, 2011: Vol.9 No.1:47-49
Template-free hydrothermal synthesis of tubular ZnO clusters and rods
Authors: Shen Xiong , Zhang Gaoke , Yang Yanqing , Yu Shujie
Published: March 2011

Tubular ZnO clusters and rods have been fabricated using a simple template-free hydrothermal method by controlling the reaction temperature, pH value and reaction time. The obtained ZnO products were characterized using scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, photoluminescence spectra and UV-vis diffuse reflectance spectroscopy. The results show that the formation of the tubular ZnO clusters and rods involves both a growth process and a dissolution process. The reaction temperature and reaction time play important roles in the formation of the ZnO clusters and rods with tubular morphologies. The possible formation mechanism of tubular ZnO is discussed.
Re-evaluation of activities of magnesium and zinc components in the magnesium—zinc binary system from very low to high temperature
Authors: Morishita Masao , Yamamoto Hiroaki , Shikada Shinichi , Kusumoto Minoru , Matsumoto Yasutomo
Published: March 2011

The activities of zinc, a
Zn, and magnesium, a
Mg, from very low to high temperatures in the Mg–Zn binary system were evaluated for the first time from the relationship between the Gibbs energies of formation, δf
G¯
o

T
, of Mg48Zn52, Mg2Zn3, MgZn2 and Mg2Zn11 and their phase equilibria. The δf
G¯
o

T
values adopted were determined in our previous calorimetric studies. It was found that the a
Zn and a
Mg values in the compounds steeply changed from the minimum to maximum as a function of the composition in a narrow solubility range. Such a change was more emphasized toward low temperatures (3 K). Since one of the dominant factors for the composition change in a narrow solubility range in Mg48Zn52 and Mg2Zn3 is the formation of vacancies at the Zn site, the relative partial molar Gibbs energies of the vacancy formation, δG
Zn vacancy
Zn, were estimated from the obtained a
Zn values. At 298 K, the δG
Zn vacancy
Zn values of Mg48Zn52 and Mg2Zn3 were 73.5 and 344.3 kJ mol−1, consistent with about the same order of the enthalpy of the vacancy formation in Ni3Al (= 173.7 kJ mol−1) as determined by positron annihilation spectroscopy. When the symmetric atomic configuration at the stoichiometric composition was violated by the formation of vacancies, the change in relative partial molar value of lattice defects was found to be large.
Development of highly cube textured nickel superconductor substrate tapes by Accumulative Roll Bonding (ARB)
Authors: Bhattacharjee Pinaki P. , Tsuji Nobuhiro
Published: March 2011

Development of cube texture ({001}〈100〉) has been investigated in pure Ni (99.97%) deformed to ultrahigh straining (e = 6.4) by accumulative roll bonding and then annealed at different temperatures for use as coated superconductor substrate. The as accumulative roll bonding processed sheets reveal a typical pure metal or copper type homogeneous deformation texture. After annealing at different temperatures, strong cube texture formation is observed and a nearly 100% cube textured tape with almost twin-free microstructure is obtained after annealing at 800°C for 1 h. The development of a sharp cube texture is accompanied by the development of a predominantly low angle boundary network. The very sharp cube texture formation in this material appears to be due to the oriented nucleation of cube grains at early stages of recrystallization and selective growth of these grains with progressing recrystallization. The results obtained indicate that accumulative roll bonding could be a very attractive route for fabricating highly cube textured superconductor substrate tapes from Ni.
Microstructual evolution of AZ80 magnesium alloy during multi-directional compression deformation at elevated temperature
Authors: Yan Hongge , Chen Jihua , Guo Qiang , Su Bin , Wu Yuanzhi
Published: March 2011

Microstructural evolution of AZ80 magnesium alloy during multi-directional compression deformation at elevated temperature was systematically investigated. The effects of deformation variables on the as-compressed microstructures and the deformation behavior were analyzed. Grain splitting that developed in various directions due to the formation of microbands was the main characteristic of microstructural evolution during hot multi-directional compression, which was different from that of the continuous uniaxial compression. Such microbands intersected each other, resulting in continuous subdivision of the coarse grains into misoriented fine domains, thus contributing to grain refinement. Further deformation led to increases in the number and misorientation of these boundaries and finally almost full development of fine equiaxed grains at high strain. A more homogeneous microstructure with fine dynamic recrystallization grains could be attained with the applied strain up to a critical strain, and after that, it was difficult to achieve further grain refinement. However, the higher reduction in each pass and the lower deformation temperature in the certain range aided grain refinement. The second phase Mg17Al12 with large particle size that remained after solution treatment experienced a series of changes with the process of breaking up, dissolving, precipitating and then re-dissolving. Fine precipitates were located at the grain boundaries, suppressing dislocation movement and preventing grain growth.
Hot rolling of binary Ti–Nb alloys Part II: mechanical properties anisotropy
Authors: Banumathy S. , Mandal R. K. , Singh A. K.
Published: March 2011

This work describes the nature of anisotropy in mechanical properties of three alloys, namely Ti-8Nb, Ti-12Nb and Ti-16Nb in the hot rolled condition. The work hardening curves of the alloys Ti-8Nb and Ti-12Nb exhibit a single slope and follow the Ludwik relation. The alloy Ti-16Nb displays two slopes in work hardening curves. This indicates that two different mechanisms are operative during tensile testing. The work hardening curves follow a modified Ludwik equation. The alloy Ti-16Nb exhibits the lowest anisotropy index and percentage in plane anisotropy. The alloy Ti-12Nb exhibits the highest values of both the anisotropy index and percentage in plane anisotropy. The low percentage in plane anisotropy of the alloy Ti-16Nb has been attributed to the presence of fibre textures. The yield loci of the hot rolled alloys have been determined using the Knoop hardness method. The results show that hot rolling induces anisotropy in yield strength and changes the shape and size of yield locus plots.
Study on Melt Spinning of Shaped Hollow Polypropylene Fibers
Authors: Prahsarn C. , Roungpaisan N. , Klinsukhon W. , Srisawat N.
Published: March 2011

Influences of polymer and processing parameters on melt spinning, features, and structures of circular and triangular shaped hollow fibers were investigated. Spinnability of triangular hollow fibers was found to be more sensitive to polymer viscosity and processing conditions than that of circular hollow counterparts such that fiber breakage occurred when polypropylene with high viscosity was employed. Relatively low temperature due to high cooling at tip of triangular shape may cause stress concentration developed in spin-line, and lead to fiber breakage. Increasing temperature enabled continuous spinning in triangular hollow fibers. The obtained triangular hollow fibers possessed slightly larger diameters but smaller percent hole areas, compared to the circular ones. Results showed that diameters and percent hole areas of both circular and triangular hollow fibers tended to decrease with increasing spinning temperature and take up velocity, but tended to increase with increasing throughput rate. From WAXD results, crystalline orientation in hollow fibers was found affected by take up velocity, and slightly by fiber configuration.
Lower Temperature Plasticizing and Extrusion of Polymer in Spherical Screw Extruder under Vibration Force Field
Authors: Zeng G. , Xu C. , Liu Y. , Qu J. , Jiang T.
Published: March 2011

Physical and mathematical model for polymer plasticizing in proposed electromagnetic dynamic spherical screw extruder were developed to explore polymer plasticizing and molding mechanism at lower temperature under vibration force field. Polymer plasticizing mechanism was studied by deriving the mathematical expressions of energy consumed and the polymer flow. The energy consumed in polymer plasticizing was depicted in terms of vibrating dissipation, polymer deformation, shear and friction energy. LDPE was used as an objective material and extruded by the extruder with the electromagnetic excitation and spherical screw. The experimental results show the good agreement with theoretical calculations. Both of them show that: Polymer processing temperature and energy consumption decrease significantly while the plasticizing rate is increased over 60% by introducing the vibration force field. The research offers experimental and theoretical references as well as the evaluation method for optimizing the polymer processing parameters and designing the vibration induced equipment.
Elastomer Nanocomposites Based on NR/EPDM/Organoclay: Morphology and Properties
Authors: Alipour A. , Naderi G. , Bakhshandeh G. R. , Vali H. , Shokoohi S.
Published: March 2011

Natural rubber/Ethylene Propylene Diene Monomer (NR/EPDM) blends of five different compositions (0/100), (25/75), (50/50), (75/25) and (100/0) with 1, 3, 5 and 7 phr organo-modified nanoclay (Cloisite 15A) were prepared by two-roll mill. The effect of organo-modified layered nanosilicates and composition on the cure characteristics, microstructure, mechanical, and rheological properties of the nanocomposites were studied. Results suggested the intercalation of polymer chains into the silicate layers which was evidenced by d-spacing results of X-ray diffraction patterns. TEM micrographs also directly confirmed XRD results. Mechanical properties of the nanocomposites depicted a nearly 40% percents increase respectively in the tensile modulus of 75NR/25EPDM containing 7 wt.% nanoclay.
Rheological Properties of Neat and Calcium Carbonate Particles Filled Polypropylene Blends under Axial Vibration Force Field
Authors: Liu Y. , Jiang T. , Zeng G. , Huang Y. , Li X.
Published: March 2011

Structures, working mechanism, data collecting and processing methods of the self-made multifunctional all-electronic rheometer for polymer composites were introduced in detail. The validity of this equipment was proved by deriving the apparent shear viscosity expression under axial vibration condition and comparing the results obtained from both this self-made rheometer and Rosand Rh7D capillary rheometer at steady state. With this equipment, the effects of calcium carbonate weight fraction, particle size and vibration parameters on apparent shear viscosity of calcium carbonate filled propylene composites were investigated. The results show that: the apparent shear viscosity of the composites increases with the filled particle concentration. However, it is seldom affected by particle size within certain a range of shear rate. While the apparent shear viscosity increases with the decrease of particle size at moderate shear rate. Besides, the apparent shear viscosity declines rapidly with the increasing vibration amplitude. However it exhibits a cosinoidal or sinusoidal trend as vibration frequency increases and peaks at the resonant frequency of the composites.
Feasibility Analysis of an In-mold Multivariate Sensor
Authors: Kazmer D. O. , Johnston S. P. , Gao R. X. , Fan Z.
Published: March 2011

The initial design of a novel multivariate sensor is described for the measurement of melt temperature, melt pressure, melt velocity, melt viscosity, and mold temperature. Melt pressure and temperature are respectively obtained through the incorporation of a piezoceramic element and infrared photodetector within the sensor head. Melt velocity is derived from the initial response of the melt temperature as the polymer melt flows across the sensor's lens. The apparent melt viscosity is then derived from the melt velocity and the time derivative of the increasing melt pressure given the cavity thickness. The feasibility of the envisioned sensor is then analyzed using a production-grade mold that is instrumented with commercial piezoelectric pressure sensors, infrared pyrometer, and thermocouples. Several predictive models of part weight are developed using multiple regression of data obtained from a design of experiments to evaluate the capability of the envisioned multivariate sensor. The results indicate a correlation coefficient, R2, of 0.79 for a model based on the machine settings, 0.80 for a model based on a cavity pressure sensor, 0.90 for a model based on the multivariate sensor, and 0.98 for a non-linear model based on the multivariate sensor. The implication is that multiple orthogonal sensing streams with high fidelity models are necessary to provide automatic quality assurance sufficient for fully automated plastics manufacturing.
Effect of Random and Block Copolypropylenes on Structure and Properties of Uniaxially and Biaxially Oriented PP Films
Authors: Tabatabaei S. H. , Ajji A. , Ghasemi H.
Published: March 2011

Cast films of two linear polypropylenes (PP) having different molecular weights and their blends with 5, 20, and 40 wt.% random and block copolymers were prepared. The produced cast films were uniaxially and biaxially hot drawn at T = 155°C using a biaxial stretcher and the changes in structure and morphology were examined and related to barrier, mechanical, haze, and tear properties. The crystallinity and crystal size distribution of the films were studied using differential scanning calorimetry (DSC). The uniaxial drawing generated a highly oriented fibrillar structure, resulting in an increase in the melting point of the films. A significant effect of the random copolymer on the size of crystallites was found using DSC, which was also confirmed from polarized optical microscopy (POM). Compared to the neat homopolymers, finer and numerous spherulites were observed for the blends. During drawing, the applied loads in the machine and transverse directions (MD and TD, respectively) were recorded and related to breaking up and tilting of the crystal lamellae. Adding the random copolymer appreciably decreased the haze of the films and hence drastically improved the clarity. Tensile properties and tear resistance of the cast films in MD and TD were evaluated. The addition of the random copolymer slightly reduced the Young modulus and tensile strength, but increased the elongation at break. A slight increase in the oxygen transmission rate (OTR) of the biaxially drawn films were observed by adding the copolymer.