bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical Care Nurses’ Role in Implementing the “ABCDE Bundle” Into Practice
Authors: Balas Michele C. , Vasilevskis Eduard E. , Burke William J. , Boehm Leanne , Pun Brenda T. , Olsen Keith M. , Peitz Gregory J. , Ely E. Wesley
Published: April 2012

Imagine working in an environment where all patients undergoing mechanical ventilation are alert, calm, and delirium free. Envision practicing in an environment where nonvocal patients can effectively express their need for better pain control, repositioning, or emotional reassurance. Picture an intensive care unit where a nurse-led, interprofessional team practices evidence-based, patient-centered care focused on preserving and/or restoring their clients’ physical, functional, and neurocognitive abilities. A recently proposed bundle of practices for the intensive care unit could advance the current practice environment toward this idealized environment. The Awakening and Breathing Coordination, Delirium Monitoring and Management, and Early Mobility (ABCDE) bundle incorporates the best available evidence related to delirium, immobility, sedation/analgesia, and ventilator management in the intensive care unit for adoption into everyday clinical practice.
Sleep and Immune Function
Authors: Ganz Freda DeKeyser
Published: April 2012

Scientists are only beginning to fully understand the purpose of sleep and its underlying mechanisms. Lack of sleep is associated with many diseases, including infection, and with increased mortality. Lack of proper sleep is an important problem in the intensive care unit, and interventions have been designed to improve it. Sleep is associated with immune function, and this relationship is partially based on the physiological basis of sleep, sleep architecture, the sleep-wake cycle, cytokines and the hypothalamic-pituitary axis.
Fluid Management Strategies in Heart Failure
Authors: Albert Nancy M.
Published: April 2012

In patients with chronic heart failure, fluid retention (or hypervolemia) is often the stimulus for acute decompensated heart failure that requires hospitalization. The pathophysiology of fluid retention is complex and involves both hemodynamic and clinical congestion. Signs and symptoms of both hemodynamic and clinical congestion should be assessed serially during hospitalization. Core heart failure drug and cardiac device therapies should be provided, and ultrafiltration may be warranted. Critical care, intermediate care, and telemetry nurses have roles in both assessment and management of patients hospitalized with acute decompensated heart failure and fluid retention. Nurse administrators and managers have heightened their attention to fluid retention because the Medicare performance measure known as the risk-standardized 30-day all-cause readmission rate after heart failure hospitalization can be attenuated by fluid management strategies initiated by nurses during a patient’s hospitalization.
So You Want to Change Practice: Recognizing Practice Issues and Channeling Those Ideas
Authors: Lusardi Paula
Published: April 2012

Applying the best evidence to support nursing practice and generating new knowledge for use in practice are the hallmarks of excellence and allow practitioners to meet patient care quality and safety priorities. Although identifying a patient care problem comes easily to staff nurses, the process of clarifying the problem and channeling those ideas through to a practice change can be daunting for bedside nurses. This article provides guidance to staff nurses who want to identify a clinical problem and change practice.
Central Neurogenic Diabetes Insipidus, Syndrome of Inappropriate Secretion of Antidiuretic Hormone, and Cerebral Salt-Wasting Syndrome in Traumatic Brain Injury
Authors: John Cynthia (Cindi) A. , Day Michael W.
Published: April 2012

Central neurogenic diabetes insipidus, syndrome of inappropriate secretion of antidiuretic hormone, and cerebral salt-wasting syndrome are secondary events that affect patients with traumatic brain injury. All 3 syndromes affect both sodium and water balance; however, they have differences in pathophysiology, diagnosis, and treatment. Differentiating between hypernatremia (central neurogenic diabetes insipidus) and the 2 hyponatremia syndromes (syndrome of inappropriate secretion of antidiuretic hormone, and cerebral salt-wasting syndrome) is critical for preventing worsening neurological outcomes in patients with head injuries.
The Journey to Zero Central Catheter–Associated Bloodstream Infections: Culture Change in an Intensive Care Unit
Authors: Southworth Sheri L. , Henman Lita Jo , Kinder Lisa A. , Sell Jennifer L.
Published: April 2012

A process change with the goal of decreasing and ultimately eliminating bloodstream infections associated with central catheters in critical care patients was implemented at Riverside Methodist Hospital. This process of implementation resulted in a culture change in the hospital’s medical surgical intensive care unit. Keys to success included a multidisciplinary team approach, support from persons with a stake in the process, and provision of continuous feedback. The lessons learned in this journey at Riverside Methodist Hospital can help caregivers at other hospitals decrease the occurrence of these life-threatening infections.
Developing Ethical Skills: From Sensitivity to Action
Authors: Robichaux Catherine
Published: April 2012

Acute and critical care nurses routinely encounter ethical “quandaries” such as providing perceived futile care. Other everyday ethically important occurrences may go unrecognized, however, thus diminishing their importance to moral nursing practice. This column presents a framework that may assist in developing specific skills to recognize and engage in both critical and everyday ethical situations with confidence. James Rest’s Four Component Model addresses the role of the moral practitioner from initial recognition that an ethical situation exists to implementation of a justifiable action. Patient/provider scenarios are used to illustrate components of Rest’s model followed by an approach to distinguish ethical from nonethical situations. Practical strategies to enhance ethical skills such as development of nursing ethics groups and providing continuing ethics education also are presented.
Factors affected decarboxylation activity of Enterococcus faecium isolated from rabbit
Authors: Pleva Pavel , Buňková Leona , Lauková Andrea , Lorencová Eva , Kubáň Vlastimil , Buňka František
Published: April 2012

Biogenic amines (BA) are basic nitrogenous compounds formed mainly by decarboxylation of amino acids. There are generated in course of microbial, vegetable and animal metabolisms. The aim of the study was to monitor factors affected production of biogenic amines by Enterococcus faecium, which is found in rabbit meat. Biogenic amines were analyzed by means of UPLC (ultrahigh performance liquid chromatography) equipped with a UV/VIS DAD detector. Decarboxylation activity of E. faecium was mainly influenced by the cultivation temperature and the amount of NaCl in this study. E. faecium produced most of the monitored biogenic amines levels: tyramine ˂2500 mg.l-1; putrescine ˂30 mg.l-1; spermidine ˂10 mg.l-1 and cadaverine ˂5 mg.l-1.
The viscosity of processed cheese sauces depending on addition type and concentration of 1-monoglycerides
Authors: Hanáková Zuzana , Buňka František , Weiserová Eva , Janiš Rahula
Published: April 2012

The aim of this work was to study viscosity of processed cheese sauces with 1-monoglycerides (MAG) addition. Six types of 1-monoglycerides (1-monocaprin, C10:0; 1-monolaurin, C12:0; 1-monomyristin, C14:0; 1-monopalmitin, C16:0; 1-monostearin, C18:0; 1-monoolein, C18:1) in concentration of 0.25 and 0.50% w/w were used. Control samples were prepared without MAG but with lecithin. The lowest values of viscosity were found in control samples. The viscosity increased with extending of chain fatty acid in the molecule of monoglycerides. The highest viscosity was found in samples with 1-monomyristin.
Contamination of propolis used as a dietary supplement
Authors: Roman Adam , Popiela-Pleban Ewa
Published: April 2012

The aim of the study was to determine the extent of chosen toxic elements (zinc, copper, lead, arsenic and cadmium) bioaccumulation in propolis collected in Opole area. The present study demonstrates that propolis can be used as a dietary supplement. The research material were samples of propolis originated from 3 bee colonies in 30 apiaries (n=3x30=90). Quantitative analysis of studied elements were conducted using Varian ICP-AES plasma spectrometer with mass detection controlled, and CETAC-5000 AT ultrasonic nebulizer. The presence of toxic elements was determined in an examined biological materials. The sequence of accumulation level of studied elements in propolis was as follows: Zn>>Cu>Pb>As>Cd. An average concentration of zinc, copper, lead, arsenic and cadmium amounted  to 56.28, 7.12, 6.91, 0.745, 0.218 mg.kg-1, respectively. Only the copper average content in propolis was within acceptable standards, whereas the mean contents of other elements greatly exceed these standards. All portions of propolis should be subjected to toxicological testing before applying these samples for internal use.
Effect of chickpea and pea flour addition on the qualitative and sensory parameters of bakery products
Authors: Magala Michal , Kohajdová Zlatica , Karovičová Jolana , Kuchtová Veronika
Published: April 2012

The purpose of this study was to determine chemical composition and functional properties of legume flours (chickpea, pea) and fine wheat flour. The effect of chickpea and pea flour incorporation at different levels (10, 20, 30 % w/w) on the qualitative parameters and sensory characteristics of bakery product was also investigated. It can be concluded, that incorporation of leguminous flours led to changes of the investigated qualitative and sensory parameters, especially in samples with higher amount of leguminous flour (20 and 30 %). Results showed, that a proper alternative to standard bakery products  are products with 10 % portion of leguminous flour.
Occurrence of some pathogenity factors in coagulase negative Staphylococci isolated from mastitis milk in dairy cows
Authors: Vasiľ Milan , Elečko Juraj , Zigo František , Farkašová Zuzana
Published: April 2012

Experiment we carried out on the herd of 115 Slovak Pied dairy cows. Were realized three collections of individual milk samples for isolation and identification of coagulase-negative staphylococci (CNS). We collected 341 milk samples. Coagulase - negative staphylococci were isolated in 18.8 % (64). Highest number of CNS we isolated from acute, subclinical, subacute and latent forms of mastitis, respectively. S. warneri (2.88 %), S. chromogenes (17.19 %), S. cohnii (15.63 %) and S. xylosus (14.06 %) was isolated in highest percentage. Was detected presence of 7 virulence factors, include production of staphylococcal enterotoxins, and resistance for antibiotics. S. chromogenes, S. warneri and S. xylosus were detected as most virulent species carrying most virulence factors, and were resistant for most species of tested antibiotics (S. xylosus resistant for N, NV, L, P, E; S. chromogenes, S. sciuri for 4 species of antibiotics). There pathogens were isolated from acute forms of mastitis.
Quality and safety of raw cow’s milk in Slovakia in 2011
Authors: Zajác Peter , Tomáška Martin , Murárová Anna , Čapla Jozef , Čurlej Jozef
Published: April 2012

The quality and safety of raw cow’s milk is very important for dairy companies and consumers of milk products. Due to the methods of production, it is impossible to completely eliminate contamination of milk with microorganisms, therefore the microbial content of milk is a major feature in determining its quality. Other important factors to consider include somatic cells count, veterinary drug residues, milk composition and freezing point. Somatic cells represent the udder health and can be used for monitoring of subclinical mastitis. A high level of somatic cells can increase proteolysis in milk which affects technological processes. Veterinary drugs administered to cows may lead to residues in the milk which are harmful to humans. The content of fat, protein and solids-non-fat are the main indicators used by dairies for technological purposes. In this article we discuss the quality and safety of raw cow’s milk in Slovakia during 2011. We found that 73.53% of samples tested for somatic cell count, and 84.54% of samples tested for total bacterial count, met the European Union legislation limits. We found the largest decrease in fat and protein content was during the summer period and the largest increase was in the winter period. We found that 92.14 %, 98.7% and 91.38% of samples met the limit presented in STN 570529:1999 for fat content, protein content and freezing point respectively. The percentage of drug positive samples was 0.087%.
Chemical composition of muscle after pollen application in nutrition of broiler chickens
Authors: Haščí­k Peter , Elimam Ibrahim Omer Elamin , Garlí­k Jozef , Kačániová Miroslava , Bobko Marek , Kňazovická Vladimí­ra , Vavrišinová Klára , Arpášová Henrieta , Bučko Ondřej
Published: April 2012

Principle purpose of this study was to monitor the chemical composition of breast and thigh muscular part of chickens of hybrid combination Ross 308 and to verify the differences due to use of pollen extract in feed mixture at a dose of 400 and 800 mg.kg-1 during the feeding of 42 days. We did not find significant differences (P≥0.05) in followed chemical compounds of thigh muscle with the skin and subcutaneous fat between the groups with and without application of pollen extract: in contents of water (68.49-70.12 g.100g-1), protein (18.82-18.98 g.100g-1), fat (9.96-11.53 g.100g-1) and in energy value (692.20-752.36 kJ.100g-1). Significant differences (P≤0.05) were found only in protein content of breast muscle between the control group (23.96 g.100g-1) and experimental group I (23.28 g.100g-1). Values of water content (73.97-74.32 g.100g-1), fat content (1.07-1.40 g.100g-1) and energy (441.65-446.64 kJ.100g-1) in breast muscle between the evaluated groups were balanced (P≥0.05). The results show that pollen extract at the concentration used in feed mixture did not effect basic chemical composition of the most valuable parts of the chicken Ross 308 carcass and we can apply it in their nutrition. Application at a dose of 800 mg.kg-1 seems to be more positive.
Effect of humic substances and probiotics on growth performance and meat quality of rabbits
Authors: Ondruška Ľubomí­r , Chrastinová Ľubica , Rafay Ján , Pospí­šilová Darina , Parkányi Vladimí­r
Published: April 2012

The aim of this work was determined effect of supplemental humic substances and probiotics on growth performance and meat quality of rabbits.  The growth performances were observed on two hundred and twelve growing rabbits assigned randomly by weight to two treatments. The treatments included: 1) Control group: in this group were rabbits fed with basal diet during all experiment (35th – 77th day), 2) experimental group: the animals were fed with basal diet+3kg/t humic substances – Humac Nature during whole experiment.  In this group was during fattening period (35th – 49th and 63rd – 70th days of age) added to feed the probiotic preparation – Propoul (Lactobacillus fermentum CCM 7158 1x108 CFU) 2 g per ten pieces. Body weight and feed intake were measured weekly in order to determine the average daily gain, average daily feed intake and gain/feed. The characteristics of meat quality were determined on twelve rabbit males at the age of 77 days, when the rabbits achieved average slaughter weight 2500g. Results of the whole experimental period showed that addition humic substances and probiotic preparation to the diet had positive effect (not significantly) on intensity of growth live weight in the last phase of fattening period. The results of this study suggest that humic substances with probiotics might be utilized as a feed additive in the rabbit diet. It could not significantly improve growth performance and meat quality of rabbits.
Changes in the physical properties of bread during storage
Authors: Pająk Paulina , Habryka Celina , Fortuna Teresa
Published: April 2012

The aim of this work was to compare the physical properties of breadcrumb during five days of storage in vacuum containers and polyethylene bags. On the basis of result it was stated, that storage of baguettes in vacuum condition and in polyethylene foil did not prevent the staling of breadcrumb. Hardness of breadcrumb stored in plastic bags on the fifth day was higher than hardness of bread stored in vacuum containers. The others texture values did not differ significantly on the fifth day of storage between packaging methods. The changes in water activity values both in vacuum containers and polyethylene bags were negligible during storage. Increase in lightness and decrease in yellowness were observed over the storage period, regardless of packaging method, while the values of a* remained essentially unchanged.
Analysis of carotenoids and lycopene in tomato (Lycopersicon esculentum Mill.) and their retention in tomato juice
Authors: Mendelová Andrea , Andrejiová Alena , Lí­šková Miriam , Kozelová Dagmar , Mareček Ján
Published: April 2012

In  this  work  we  investigated  the  effect  of  variety  and  processing  on  the  content  of  carotenoids  and  lycopene  in  fruits  and Tomato  juice  from  the  fruit  after  heat  treatment.  The  experiment  included  four  varieties  are edible  tomato  for  industrial processing (Báb, Žiara PK, Šampion and Roti PK). The concentration of total carotenoids and lycopene were determined spectrophotometrically  on  UV-VIS  spectrophotometer  Jenway  at  a  wavelength  of  445  and  472  nm.  The  highest  average content  of  carotenoids  in  fruits  were  recorded  at  a  variety  Roti  PK  (7.0  mg/100 g-1)  and  lowest  in  variety  Báb (4.8 mg/100 g-1). Heat treatment had a statistically significant positive effect on the lycopene content, changes in carotenoid content were not significant. Effect of genotype (variety) for the content of the endpoint was significantly important.
Physicochemical properties of starch-maltodextrin and starch-maltodextrin-glucose systems
Authors: Sobolewska-Zielińska Joanna , Grzelak Magdalena , Fortuna Teresa
Published: April 2012

Starch is a widely used food additive. The addition of other ingredients changes the physical properties of resulting systems. The aim of this study was to investigate the rheological characteristics and susceptibility to retrogradation of starch-maltodextrin and starch-maltodextrin-glucose systems. Flow curves of 5% starch - maltodextrin and starch-maltodextrin-glucose pastes were tested by using rotational rheometer. The susceptibility to retrogradation of 2% pastes starch-maltodextrin and starch-maltodextrin-glucose systems by means of turbidimetric method was evaluated. It was found that all samples (systems) were a non-Newtonian, pseudoplastic fluids, with tend to the yield stress. Moreover addition of low and high DE maltodextrins and glucose to the starch caused a decrease in the values of shear stress throughout whole shear rate range. Starch pastes with greater concentration of the maltodextrins had less tendency to retrogradation. Also addition of glucose to starch-maltodextrin systems reduce the susceptibility to retrogradation.
The effect of reduction concentrations of the broiler chickens per unit area on the final live weight and production economics
Authors: Angelovičová Mária , Kliment Martin , Mrázová Ľubica , Tkáčová Jana , Kráľ Martin , Alfaig Ebrahim , Lopašovský Ľubomí­r
Published: April 2012

The aim of the present study was a mathematical and statistical assessment for the effect of concentration of broiler chickens per unit area to the final live weight and production economics. Cobb 500 chickens were fattening for 42 days in a hall on deep litter. During the two experiments the chickens were divided to two groups according to concentration per unit area and it was about 30 and 25 kg/m2. The experiments had been complied with recommended  nutritional  requirements  for  breeding  and  final fattening type of chickens Cobb500. The average final weight of broiler chickens in the first experiment were 2.14 and 2.17 kg for concentrations of 29.41 and 25.76 kg/m2 respectively, and for the second experiment  were 2.01 and 2.02 kg for concentrations of 29.33 and 23.90 kg/m2 respectively. According to statistical analysis (P≥0.05), the average final live weight of broiler chickens was not affected by concentrations.  The calculated production total live weight of broiler chickens across the halls were 48526.5, 48 394.5, 42504.0 and 39435.0 kg at a concentrations of 29.41, 29.33, 25.76 and 23.90 kg/m2 respectively.  By reducing the concentration of birds in the hall from 29.41 to  29.33 kg/m2 and from 25.76 to 23.9 kg/m2   the total production of broiler chickens was decreased by 6022.5 and  8959.5 kg live weight respectively. The concentration of birds per unit area of ​​25.76 and 23.90 kg/m2 lead to lower the  price of the product of broiler chickens by 4745.73 and 7060.09 € respectively, compared with  the price for the product of the concentrations of 29.41and  29.33 kg/m2 respectively.
Enterococci and their ability to form a biofilm
Authors: Čanigová Margita , Ducková Viera , Kročko Miroslav , Račková Jana , Bezeková Jana
Published: April 2012

Number of enterococci determined in raw milk cistern samples was in range of 2.95 to 4.18 log CFU.ml-1 and raw milk samples obtained from storage tanks contained enterococci count in the range of 3.04 to 4.51 log CFU.ml-1. Results of microbiological quality evaluation showed, that count of enterococci increased during cold storage of raw milk. Portion of enterococci from the total microflora of raw milk taken from cistern samples was 0.44 %, otherwise in raw milk samples taken from storage tanks portion of enterococci decreased to 0.38 %. Among enterococci isolates  E. faecalis was the predominat species in tested samples of raw milk from both cistern – 58.1 % and storage tank – 71.7 %. The following species were identified E. faecium, E. group III., E. mundtii, E. casseliflavus. It was found that 38 % E. faecalis isolates were able to form a biofilm.
Identification of oenological tannins extracted from oak wood
Authors: Návojská Jana , Wendelin Silvia , Eder Reinhard , Frančáková Helena
Published: April 2012

Our study is dealing with the determination of the origin of oenological tannins using the modified OIV procedure. The method is based on HPLC analyses of proanthocyanidol content (catechin, epicatechin, epigallocatechin, epicatechin-3-O-gallate and epigallocatechin-3-O-gallate) after thioacidolysis - thiolytic cleavage of the flavonol intermonomer linkages in proanthocyanidols under heat in an acid medium. The purpose of the study was to differentiate oenological tannins gained from Quebracho cortex and tannins extracted from oak wood. As the results show, both groups of tannins do not produce any flavan-3-ols after thioacidolysis, but they show specific peaks, which enable determination of their origin.
HIV/AIDS Model with Early Detection and Treatment
Authors: Mbitila Augustine S. , Tchuenche Jean M.
Published: April 2012

A classical epidemiological framework is used to qualitatively assess the impact of early detection and treatment on the dynamics of HIV/AIDS. Within this theoretical framework, two classes of infected populations: those infected but unaware of their serological status and those who are aware of their disease status, are considered. In this context, we formulate and analyze a deterministic model for the transmission dynamics of HIV/AIDS and assess the potential population-level impact of early detection in curtailing the epidemic. A critical threshold parameter for which case detection will have a positive impact is derived. Model parameters sensitivity analysis indicates that the number of partners is the most sensitive (in increasing the average number of secondary transmission) parameter. However, the case detection coverage is the main drivers in reducing the initial disease transmission. Numerical simulations of the model are provided to support the analytical results. Early detection and treatment alone are insufficient to eliminate the disease, and other control strategies are to be explored.
Porphyromonas gingivalis Fimbria-Induced Expression of Inflammatory Cytokines and Cyclooxygenase-2 in Mouse Macrophages and Its Inhibition by the Bioactive Compounds Fibronectin and Melatonin
Authors: Murakami Yukio , Machino Mamoru , Fujisawa Seiichiro
Published: April 2012

Porphyromonas gingivalis (Pg) fimbriae, in addition to lipopolysaccharide, are involved in the pathogenesis of periodontal disease. At the same time, bioactive compounds such as fibronectin (FN) and melatonin in saliva and gingival crevicular fluid have been reported to exert a preventive effect against periodontitis. Here, we review current knowledge regarding the potent inhibitory effects of FN and melatonin against Pg fimbria-induced induction of proinflammatory cytokines, cyclooxygenase-2 (COX-2) expression, and NF-kappa B activation in mouse macrophages and discuss their possible clinical application for prevention of periodontal diseases induced by oral bacteria.
POEMS Syndrome: A Report of 14 Cases and Review of the Literature
Authors: Ji Zong Fei , Zhang Dan Ying , Weng Shu Qiang , Shen Xi Zhong , Liu Hou Yu , Dong Ling
Published: April 2012

POEMS syndrome is a rare paraneoplastic disorder associated with an underlying plasma cell dyscrasia presenting polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. This study reviewed the clinical characteristics of 14 POEMS patients in Zhongshan hospital. The ratio of male to female was 9 : 5, and the average age was 47.1 years. The clinical manifestations were various, including motorial symptoms (weakness), sensory symptoms (numbness), lymphadenopathy, edema, abdominal distention, and skin hyperpigmentation. Imaging studies and laboratory tests also exhibited hepatomegaly, splenomegaly, thrombocytosis, endocrinopathy, and positive serum immunofixation in most patients. In addition, increased plasma cells in bone marrow and Castleman Disease were found in bone marrow and lymph nodes biopsies. All the eight follow-up patients were treated with alkylator-based combination chemotherapy or corticosteroids and thalidomide, with or without autologous stem cell transplantation. Unfortunately, two patients died three or four years after diagnosis of POEMS syndrome. The others showed response to therapy to some extent, but not completely remission. Currently, treatments for POEMS include radiation to the plasmacytoma, and systemic therapy is indicated. Low-dose alkylators with or without corticosteroids are effective in some patients. However, high-dose chemotherapy with auto-SCT dramatically improved symptoms and outcomes for POEMS patients.
The lichen family Parmeliaceae in Poland. II. The genus Cetrelia
Authors: Kukwa Martin , Pietnoczko Magdalena , Czyżewska Krystyna
Published: April 2012

In a study of the genus Cetrelia in Poland, four taxa have been identified, two of which, C. chicitae and C. monachorum, are reported for the first time from the country. All taxa differ in chemistry and subtle morphological characters. Cetrelia monachorum is the commonest member of the genus in Poland (237 records), whereas C. chicitae is known only from 6 records. All taxa are endangered, and three, C. cetrarioides, C. chicitae and C. olivetorum, appear to be critically so, thus deserving the category CR; although C. monachorum is the most frequent, it is not common and should be treated as endangered (EN). The distribution of all taxa, their habitat requirements, as well as morphology and secondary chemistry, are discussed.
Single‐Molecule Tracking of Fibrinogen Dynamics on Nanostructured Poly(ethylene) Films
Authors: Kastantin Mark , Keller Thomas F. , Jandt Klaus D. , Schwartz Daniel K.
Published: March 2012

Using fibrinogen (Fg) protein as a probe molecule, mapping using accumulated probe trajectories (MAPT) is performed on nanostructured melt‐drawn high‐density poly(ethylene) (HDPE) films composed of well‐oriented crystalline patches separated by amorphous regions. The spatially grouped molecular trajectories allow for identification of regions with distinct surface properties (i.e., crystalline vs. amorphous) while simultaneously determining the characteristic dynamic protein behavior within those regions. In the presence of solution with a sufficiently high Fg concentration, discrete patches of a dense, ordered protein layer form (presumably on crystalline HDPE regions), leading to a dramatic rise in the surface residence time (by more than two orders of magnitude) of molecules incorporated into the film. Within this ordered Fg layer, individual molecules exhibit slow anisotropic lateral diffusion; the mobility is restricted by the nanostructure boundaries of the underlying HDPE. On HDPE films at low Fg surface coverage, or on films that have been rendered hydrophilic with Ar plasma, short surface residence times and fast, isotropic diffusion are observed. These results demonstrate the ability of spatially resolved single‐molecule tracking to provide mechanistic information about biomolecule‐surface interactions in a highly heterogeneous environment.
High‐Performance Inverted Polymer Solar Cells: Device Characterization, Optical Modeling, and Hole‐Transporting Modifications
Authors: Zou Jingyu , Yip Hin‐Lap , Zhang Yong , Gao Yan , Chien Shang‐Chieh , O'Malley Kevin , Chueh Chu‐Chen , Chen Hongzheng , Jen Alex K.‐Y.
Published: March 2012

Although high power conversion efficiencies (PCE) have already been demonstrated in conventional structure polymer solar cells (PSCs), the development of high performance inverted structure polymer solar cells is still lagging behind despite their demonstrated superior stability and feasibility for roll‐to‐roll processing. To address this challenge, a detailed study of solution‐processed, inverted‐structure PSCs based on the blends of a low bandgap polymer, poly(indacenodithiophene‐co‐phananthrene‐quinoxaline) (PIDT‐PhanQ) and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) as the bulk heterojunction (BHJ) layer is carried out. Comprehensive characterization and optical modeling of the resulting devices is performed to understand the effect of device geometry on photovoltaic performance. Excellent device performance can be achieved by optimizing the optical field distribution and spatial profiles of excitons generation within the active layer in different device configurations. In the inverted structure, because the peak of the excitons generation is located farther away from the electron‐collecting electrode, a higher blending ratio of fullerene is required to provide higher electron mobility in the BHJ for achieving good device performance.
Mitigation of Staphylococcus aureus‐Mediated Surgical Site Infections with IR Photoactivated TiO2 coatings on Ti Implants
Authors: Aboelzahab Asem , Azad Abdul‐Majeed , Dolan Shawn , Goel Vijay
Published: March 2012

Surgical site infections caused by methicillin‐resistant and methicillin‐susceptible Staphylococcus aureus (MRSA, MSSA) lead to patient hospitalization for an extended period coupled with concomitant hospitalization resources and cost. The detrimental effect resulting from the onset of these infections poses great health risks, leading to death in some instances. Titanium dioxide (TiO2) is endowed with the unique capability of photoactivity which has been extensively exploited in antibacterial activities. It has been shown to be very effective in its bactericidal efficacy against infection‐causing bacterial strains, namely, E. coli and S. aureus. In this study, the use of IR‐photoactivated TiO2 nanocoatings on titanium implants to mitigate the onset of surgical site infections is described. TiO2 coatings were created on implantable materials by way of an aqueous plasma electrodeposition technique and were used to mitigate the harmful bacterial growth upon brief activation by an infrared (IR) laser source. The necrosis of S. aureus cells was found to exceed 90% within 30 min. following a 30s exposure of the titania‐coated model implants (Ti mesh and plate). Promising potential of antibacterial coatings in mitigating surgical site infections has been shown.
Epilepsy, suicidality, and psychiatric disorders: A bidirectional association
Authors: Hesdorffer Dale C. , Ishihara Lianna , Mynepalli Lakshmi , Webb David J. , Weil John , Hauser W. Allen
Published: April 2012

Objective:

A study was undertaken to determine whether psychiatric disorders associated with suicide are more common in incident epilepsy than in matched controls without epilepsy, before and after epilepsy diagnosis.

Methods:

A matched, longitudinal cohort study was conducted in the UK General Practice Research Database. A total of 3,773 cases diagnosed with epilepsy between the ages of 10 and 60 years were compared to 14,025 controls matched by year of birth, sex, general practice, and years of medical records before the index date. We examined first diagnosis of psychosis, depression, anxiety, and suicidality in each of the 3 years before and after the index date and annual prevalence of suicide. Referent diagnoses were eczema and acute surgery. The incidence rate ratio (IRR) was calculated for each year in the study period; the prevalence ratio (PR) was calculated for suicidality.

Results:

The IRR of psychosis, depression, and anxiety was significantly increased for all years before epilepsy diagnosis (IRR, 1.5–15.7) and after diagnosis (IRR, 2.2–10.9) and for suicidality before epilepsy diagnosis (IRR, 3.1–4.5) and 1 year after diagnosis (IRR, 5.3). The PR was increased for suicide attempt before epilepsy onset (PR, 2.6–5.2) and after onset (PR, 2.4–5.6). Eczema and acute surgery were both associated with epilepsy in the first and third year after diagnosis.

Interpretation:

Epilepsy is associated with an increased onset of psychiatric disorders and suicide before and after epilepsy diagnosis. These relations suggest common underlying pathophysiological mechanisms that both lower seizure threshold and increase risk for psychiatric disorders and suicide. ANN NEUROL 2012
Synthesis and characterization of heat‐resistant N‐phenylmaleimide–styrene–maleic anhydride copolymers and application in acrylonitrile–butadiene–styrene resin
Authors: Zhao Chenyang , Dong Jianting , Li Suming , Fan Zhongyong
Published: March 2012

The heat‐resistant copolymer of N‐phenylmaleimide (NPMI)–styrene (St)–maleic anhydride (MAH) was synthesized in xylene at 125°C with di‐tert‐butyl diperoxyterephthalate as an initiator. The characteristics of the copolymer were analyzed by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy (1H‐NMR and 13C‐NMR), gel permeation chromatography, and elemental analysis. The 13C‐NMR results show that the copolymer possessed random sequence distribution; this was also supported by the differential scanning calorimetry experiment, in which a single glass‐transition temperature (Tg) of 202.3°C was observed. The thermal stability and degradation mechanism of the copolymer were investigated by thermogravimetric analysis. Using the Kissinger equation and Ozawa equation, we proved a nucleation controlling mechanism with an apparent activation energy of 144 kJ/mol. Blends of acrylonitrile–butadiene–styrene with the NPMI–St–MAH copolymer with various contents were prepared with a twin‐screw extruder processes. The mechanical and thermal properties of the materials, such as the tensile and flexural strength, Tg's, and Vicat softening temperatures, were all enhanced with the addition of the modifier, whereas the melt flow index decreased. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Toughened polystyrene with improved photoresistance: Effects of the compatibilizers
Authors: Libio Illen Canani , Grassi Vinícius Galhard , Dal Pizzol Marcus Fernando , Bohrz Nachtigall Sônia Marlí
Published: March 2012

The dispersion of ethylene–propylene–diene terpolymer (EPDM) rubber in a polystyrene (PS) matrix is an alternative for improving the weathering resistance of high‐impact polystyrene (HIPS), which commonly contains polybutadiene as an impact modifier. However, EPDM and PS are immiscible, and compatibilizers are required to improve the final properties. In this study, EPDM–PS blends were prepared by melt mixing, and the compatibilizing effects of two block copolymers on these blends was studied. The materials were analyzed by scanning electron microscopy, tensile and impact tests, and exposure to UV light for 20 days. The addition of styrene–butadiene–styrene block copolymer (SBS) and styrene–ethylene‐co‐butylene–styrene block copolymer (SEBS) improved the dispersion of EPDM in the PS matrix. The compatibilized blends showed lower tensile properties, but an important increase in the impact strength was observed compared to the noncompatibilized blend. With regard to the impact strength, SBS was more effective than SEBS as a compatibilizer. All of the blends showed higher UV resistances than the commercial HIPS, and the best performance was observed in the blends compatibilized with SEBS. These results are discussed and explained in terms of the blends' morphologies and chemical compositions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Tube extrusion of polymeric materials: Optimization of the processing parameters
Authors: Mamalis A. G. , Vortselas A. K. , Kouzilos G.
Published: March 2012

In the study described in this article, we aimed to apply multiparametric optimization to the processing conditions in a spider die used for the extrusion of polymers, in this case, high‐density polyethylene tubes. Product quality is affected by the homogeneity of the flow speed and the temperature at the die exit. Inhomogeneity causes shape distortions and material weak spots (weld lines), and its major cause in spider dies is the discontinuity and distortion of the flow caused by spider legs, the ties by which the inner mandrel of the die is secured to its external casing. The Nelder–Mead nonlinear optimization technique was applied to the numerical model to pinpoint the processing conditions, namely, the inlet pressure, inlet temperature of the melt, temperature of the die walls, and temperature of the spider legs. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Properties and morphology of supertoughened polyamide 6 hybrid composites
Authors: Ding Yun , Chen Guangxin , Song Jiangxuan , Gou Yunshu , Shi Jianjun , Jin Riguang , Li Qifang
Published: March 2012

In this study, supertoughened polyamide (PA) nanocomposites were prepared by the incorporation of epoxidized polyhedral oligomeric silsesquioxane (POSS) into the polyamide 6 (PA6)/methyl methacrylate–butadiene–styrene copolymer (MBS) blend via a melt‐blending method. The effect of POSS on the rheological properties, mechanical properties, water uptake, and morphology of the hybrid PA6 nanocomposites was studied. The results show that under impact loading, the hybrid PA6 composites exhibited significant improvements in both the crack initiation energy and the crack propagation energy. This hybrid composite showed supertough behavior. Meanwhile, the tensile strength and the water absorption resistance was also improved with the addition of epoxidized POSS. The capillary and torque rheological results indicated that the epoxidized POSS, which acted as nanoscale ball bearings, significantly decreased the melt viscosity of the matrices and facilitated the melting process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed to study the microstructure–property relationships of the hybrid PA6 composites. The TEM results showed that the MBS particles were dispersed homogeneously in the PA6 matrix. The mean diameter of the MBS particles decreased, and the size distribution of the MBS particles narrowed down with the introduction of the epoxidized POSS and compatiblizer. The SEM micrographs indicated that the impact fracture surfaces of the PA composites showed morphological characteristics of supertough polymers because of the synergistic effect of the functionalized POSS and compatibilized MBS particles. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and properties of maleimide‐functionalized hyperbranched polysiloxane and its hybrids based on cyanate ester resin
Authors: Hu Jiang‐tao , Gu Aijuan , Liang Guozheng , Zhuo Dongxian , Yuan Li
Published: March 2012

A new hyperbranched polysiloxane containing maleimide (HPMA) was synthesized through the reaction between N‐(4‐hydroxyphenyl) maleimide and 3‐glycidoxypropyltrimethoxysilane, which was then used to prepare cyanate ester (CE) resin‐based hybrids (coded as HPMAx/CE, where x is the weight fraction of HPMA in the hybrid). The curing behavior of uncured hybrids and the typical properties (impact strength and dielectric properties) of cured hybrids were systemically investigated. Results show that the performance of hybrids is greatly related with the content of HPMA. Hybrids have obviously lower curing temperature than CE, overcoming the poor curing characteristics (higher curing temperature and longer curing time) of neat CE, for example, the curing peak temperature of HPMA20/CE is about 65°C lower than that of CE. In the case of cured resin and hybrids, the hybrids exhibit decreased dielectric constant and loss than CE resin; moreover, the former also exhibits lower water absorption than the latter. Specifically, the dielectric loss of HPMA15/CE hybrid is only about 27% of that of neat CE resin. In addition, the hybrids with suitable contents of HPMA have significantly improved impact strengths. The overall improved properties suggest that HPMAx/CE hybrids have great potential in applications needing harsh requirements of curing feature, dielectric properties, and toughness. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Chiral recognition of tryptophan enantiomers based on a polypyrrole‐flake graphite composite electrode column
Authors: Kong Yong , Li Xueying , Yao Chao , Wei Jingxuan , Chen Zhidong
Published: March 2012

A polypyrrole (PPy)‐flake graphite composite was synthesized by in situ polymerization of pyrrole on flake graphite surface, and the resulting organic–inorganic composite material was developed as the conductive stationary phase in an electrode column for enantioselective recognition of tryptophan (Trp) enantiomers. Compared with the stationary phase made up with conducting PPy, the conductivity of the composite stationary phase was enhanced significantly. As a result, satisfactory enantioselectivity of Trp enantiomers can be achieved easily by modulating the potential applied on the electrode column. Various important parameters influencing the performance of the composite electrode column were investigated to obtain the optimum recognition efficiency. A recognition efficiency of 3.7 could be achieved under the optimum conditions. Enantioselectivity of the composite material for Trp enantiomers is attributed to the reversible doping/de‐doping properties of PPy. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of novel aromatic polyamides via Yamazaki–Higashi phosphorylation method
Authors: Zhao Jing , Xu Hongjie , Fang Jianhua , Yin Jie
Published: March 2012

We synthesized four aromatic diacids: 1,3‐bis(3‐carboxyphenoxy)benzene, 1,4‐bis(4‐carboxyphenoxy)benzene, 1,4‐bis(3‐carboxyphenoxy) benzene, and 1,3‐bis(4‐carboxyphenoxy)benzene, following a procedure of a previously reported synthesis (Ueda and Komatsu, J Polym Sci Part A: Polym Chem 1989, 27, 1017). These diacids were condensed directly with aromatic diamines 4,4′‐oxydianiline (ODA), via the Yamazaki–Higashi phosphorylation method in the presence of triphenylphosphite (TPP), pyridine (Py) and halide salts to give high molecular aromatic polyamides (PAs). The synthesized PAs were obtained in quantitative yields with inherent viscosities between 0.5 and 1.0 dL g−1. The structures and properties of the obtained PAs were characterized by Fourier transform infrared (FTIR) spectra, nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), polarizing optical microscope (POM). Four PAs all showed good solubility in polar solvents, such as dimethylsulfoxide (DMSO), N,N‐dimethylacetamide (DMAc), N‐dimethylformamide (DMF), 1‐methylpyrrolidone (NMP), and so on. The obtained polymers showed high thermal stability with decomposition temperature around 400°C. The polyamide membranes manifest excellent mechanical properties, with Young's modulus of 2.5–5.5 GPa. Interestingly, the film of PA‐1, PA‐2, and PA‐3 is completely transparent in the visible range, while PA‐4 film is opaque. Crystallization was observed in PA‐4 film, although the molecular structure of PA‐4 is not as symmetrical as PA‐2. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Designing polyethylene terephthalate‐based barrier resins
Authors: Gohil Ramesh M.
Published: March 2012

We have studied the efficiencies of commercially available barrier resins used for food packaging and beverage bottle applications and compared them with resins made using copolymer and blending approaches. The effects of various copolymer related parameters that influence oxygen barrier performance and the underlying mechanisms for these effects in PET‐based copolymers and blends were investigated. Using these approaches, it is possible to make highly effective PET‐based copolymers for gas barrier applications. Blending of PET with phenolic and other organic materials shows equivalent barrier performance in PET copolymers having comonomer levels of <8‐mole %. Reduction in oxygen permeation rates results from the reduction or elimination of short range molecular motion of polyethylene terephthalate molecules. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Seed journal citation network maps: A method based on network theory
Authors: Calero Medina C.M. , van Leeuwen T.N.
Published: March 2012

The study presented here shows a method based on network theory to identify the most important journals related to a given journal, the seed journal. In just one simple network map, we get the relevant citation environment of a specific seed journal. It is of interest to librarians, publishers, scientists and science policy makers. These journal citation network maps are useful for these various stakeholders in and around the science system, as they provide information on the level of journal connections, unlike the more traditional structures such as the Journal Subject Categories, the classification system applied in the products of Thomson Reuters (Journal Citation Reports, Web of Science, etc.). These network maps show the closest relations journals can have, based on citation relations, suggesting influence relations between journals in such a way that traditional field boundaries are transcended.
Interactions between journal attributes and authors' willingness to wait for editorial decisions
Authors: Rousseau Sandra , Rousseau Ronald
Published: March 2012

In this article, we report on a discrete choice experiment to determine the willingness‐to‐wait (WTW) in the context of journal submissions. Respondents to our survey are mostly active in the information sciences, including librarians. Besides WTW, other attributes included in the study are the quality of the editorial board, the quality of referee reports, the probability of being accepted, the ISI impact factor, and the standing of the journal among peers. Interaction effects originating from scientists' personal characteristics (age, region of origin, motivations to publish) with the WTW are highlighted. A difference was made between submitting a high quality article and a standard article.

Among the interesting results obtained from our analysis we mention that for a high‐quality article, researchers are willing to wait some 18 months longer for a journal with an ISI impact factor above 2 than for a journal without an impact factor, keeping all other factors constant. For a standard article, the WTW decreases to some 8 months. Gender had no effect on our conclusions.