bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemolysis of red blood cells after cell washing with different automated technologies: clinical implications in a neonatal cardiac surgery population
Authors: O'Leary Mandy Flannery , Szklarski Penny , Klein Thomas M. , Young Pampee Paul
Published: November 2010

BACKGROUND: In subsets of pediatric cardiac surgery patients, red blood cells (RBCs) are often washed to reduce extracellular potassium (K) to avoid hyperkalemia, but mechanical manipulation and time delay in issuing washed products may increase hemolysis and K. This study's purpose was to evaluate the quality of washed RBCs with regard to hemolysis and extracellular K using different cell washers as a function of postprocessing time.

STUDY DESIGN AND METHODS: Fresh (<4 days old) RBCs were washed on COBE 2991 blood cell processors (Model 1 and Model 2) or the Fresenius Continuous AutoTransfusion System (CATS), and K and hemolysis index (HI) were analyzed. Academic pediatric hospitals were surveyed to ascertain practice trends regarding indications for washing, washing device, and expiration time for washed RBCs.

RESULTS: K concentration at 24 hours for units washed with the COBE devices met or exceeded prewash values. At 12 hours, there was a significant difference (p < 0.001) in K concentration between all devices, with the CATS maintaining the lowest K concentration. HI increased immediately after wash on all devices and showed a significant difference between the COBE devices and CATS at times of more than 6 hours (p < 0.01). At storage times beyond 4 hours, hemoglobin exceeded 100 mg/dL on the COBE Model 1. Survey of pediatric hospitals indicated that COBE devices are commonly used, and storage time after washing was 12 hours or more in blood banks queried.

CONCLUSIONS: Hemolysis levels vary among different cell washers. Decreasing the expiration time of units after washing may be warranted.
Cryoballoon Ablation of Atrial Fibrillation
Authors: KUCK KARL‐HEINZ , FÜRNKRANZ ALEXANDER
Published: November 2010

Cryoballoon Ablation of Atrial Fibrillation.  Pulmonary vein isolation using a cryoballoon has evolved into a relatively simple alternative for point‐by‐point radiofrequency ablation because this technology theoretically allows for PV isolation with a single application. Recent clinical studies indicate a high efficacy rate of the procedure; however, the incidence of the most common complication—phrenic nerve palsy (PNP)—has been reported in up to 11.2% of cases. Based on the present data, PNP is mainly associated with the use of the smaller 23 mm balloon. Very recently, it became evident that cryoballoon ablation may be associated with PV stenosis. Thus, the use of cryoballoon technology needs to be combined with a strategy aiming for maximal patient safety. The “single big (28 mm) cryoballoon technique” is a straightforward single‐device strategy to deploy cryothermal lesions proximal to the PV ostium at the antrum level, thereby reducing the risk of collateral damage. Using this technique the endpoint of complete PV isolation was achieved in 97% of patients in our laboratory. PNP was observed in 4.4% of patients and resolved within 12 months in the majority of cases. In the future, development of an even bigger (32 mm) cryoballoon may further increase procedural safety by reducing the risk of PNP or PV stenosis. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1427‐1431, December 2010)
Influence of Conductive Nano‐TiC on Microstructural Evolution of Si3N4‐Based Nanocomposites in Spark Plasma Sintering
Authors: Lee Ching‐Huan , Lu Horng‐Hwa , Wang Chang‐An , Nayak Pramoda K. , Huang Jow‐Lay
Published: November 2010

A conductive TiC nanopowder was incorporated into nanosized β‐Si3N4‐based powder and consolidated by a spark plasma sintering (SPS) technique with a rapid heating process. The influence of the conductive phase on the microstructure development of the Si3N4matrix was demonstrated. After sintering, the conductive phase transformed into titanium oxycarbonitride. The Si3N4‐based composite containing 5 wt% nano‐TiCxOyNzshows a larger average grain size and aspect ratio than the monolithic Si3N4‐based ceramic. This is possibly because a leakage current hops across the conductive titanium oxycarbonitride grains and causes Joule heating during sintering. The transmission electron microscopy analysis confirmed that dissolution–reprecipitation and coalescence occur. In addition, although the increasing amount of incorporated nano‐TiCxOyNz(10 and 20 wt%) decreases the electrical resistivity of the composites, the pinning effect of the titanium‐based phase significantly suppresses the grain growth of Si3N4matrix grains. β‐Si3N4‐based nanocomposites containing nanosized titanium oxycarbonitride were thus obtained in the present study.
Divalent Europium in β‐Irradiated Aluminoborosilicate Glass
Authors: Malchukova Eugenia , Boizot Bruno
Published: November 2010

The reduction processes of Eu3+ ions in aluminoborosilicate glasses were studied using both high‐temperature melting in air and β‐irradiation by time‐resolved luminescence and electron paramagnetic resonance spectroscopies. The Eu2+ ions produced during the synthesis are characterized by the UV excited broadband luminescence in the blue region due to the 4f65d1–4f7 transition. This band revealed the presence more than one Eu2+ site participating in the emission with different crystalline fields and with different covalency of surrounding ligands. In irradiated glasses, the observed redshift of the Eu2+ emission band is related to the different relative proportion between Eu2+ sites.
A Novel Configuration for Infiltration and Growth of Single‐Domain Gd–Ba–Cu–O Bulk Superconductor
Authors: Li Guo‐Zheng , Yang Wan‐Min
Published: November 2010

A novel configuration was developed and then used for infiltration and growth (IG) of single‐domain Gd–Ba–Cu–O (GdBCO) bulk superconductor. The morphology, microstructure, and superconducting property of the GdBCO product were investigated. It is found that, the novel configuration can increase the stability of the sample during the IG process at high temperature, and can also contribute to the complete growth of the whole bulk. The results are helpful to increase the stability and repeatability of the experiments.
On the reaction of d‐amino acid oxidase with dioxygen: O2 diffusion pathways and enhancement of reactivity
Authors: Rosini Elena , Molla Gianluca , Ghisla Sandro , Pollegioni Loredano
Published: November 2010

Evidence is accumulating that oxygen access in proteins is guided and controlled. We also have recently described channels that might allow access of oxygen to pockets at the active site of the flavoprotein d‐amino acid oxidase (DAAO) that have a high affinity for dioxygen and are in close proximity to the flavin. With the goal of enhancing the reactivity of DAAO with oxygen, we have performed site‐saturation mutagenesis at three positions that flank the putative oxygen channels and high‐affinity sites. The most interesting variants at positions 50, 201 and 225 were identified by a screening procedure at low oxygen concentration. The biochemical properties of these variants have been studied and compared with those of wild‐type DAAO, with emphasis on the reactivity of the reduced enzyme species with dioxygen. The substitutions at positions 50 and 225 do not enhance this reaction, but mainly affect the protein conformation and stability. However, the T201L variant shows an up to a threefold increase in the rate constant for reaction of O2 with reduced flavin, together with a fivefold decrease in the Km for dioxygen. This effect was not observed when a valine is located at position 201, and is thus attributed to a specific alteration in the micro‐environment of one high‐affinity site for dioxygen (site B) close to the flavin that plays an important role in the storage of oxygen. The increase in O2 reactivity observed for T201L DAAO is of great interest for designing new flavoenzymes for biotechnological applications.
Ultrasound guidance for central venous catheter placement in Australasian emergency departments: Potential barriers to more widespread use
Authors: Matera Jakub T , Egerton‐Warburton Diana , Meek Robert
Published: November 2010

Objectives:  To survey Fellows of the Australasian College for Emergency Medicine (FACEMs) in order to describe current ultrasound (US) usage during central venous catheter (CVC) placement and to compare practice and opinions between FACEMs routinely using US and those not.

Methods:  Descriptive and analytical cross‐sectional electronic survey of all FACEMs. Baseline variables including hospital type, US availability, frequency of CVC insertion, US usage and technique are presented descriptively. US practice and opinions on usage are compared between routine and non‐routine users.

Results:  Responses were obtained from 486 (42.4%) of 1146 FACEMs emailed. Whereas 88.5% of respondents had US available and 70% had done an US course, only 37% routinely used US for CVC placement. Completion of an US course and performance of >11 CVC per year were strongly associated with routine US use (odds ratio 10.0 [5.5–18.4] and 2.6 [1.7–3.9], respectively). Common barriers to more frequent US use were not having completed an US course (20%) and US‐guided CVC placement taking too long (18%). Eighty‐five per cent of FACEMs agreed that there should be ED access to US and US training but only 34% thought its use should be mandatory.

Conclusions:  We found that only 37% of FACEM respondents routinely used US to guide placement of CVCs and a number of barriers to more frequent use are identified. Practices and opinions regarding US use differed significantly between routine and non‐routine users.
Risk scores and decision making: the anatomy of a decision to reduce breast cancer risk
Authors: Holmberg Christine , Daly Mary , McCaskill‐Stevens Worta
Published: November 2010

holmberg c, daly m & mccaskill‐stevens w (2010) Journal of Nursing and Healthcare of Chronic Illness2, 271–280 Risk scores and decision making: the anatomy of a decision to reduce breast cancer risk

Aim. To report the use of a risk score for risk treatment decision‐making in women at risk for breast cancer in order to better understand their decision‐making situation.

Background. Tamoxifen and Raloxifene are medications that have been proven to reduce the risk of breast cancer. However, women who understand their personal net benefit from Tamoxifen use chose not to take the medication. To understand this decision, the paper investigates the use of epidemiological risk information in the decision‐making process for risk‐reducing treatments.

Methods. The narratives of two women are analysed as they recall their risk score and explain their decision‐making process concerning participation in the study of Tamoxifen and Raloxifene. Both in‐depth interviews follow a narrative approach and were recorded in a US cancer center in 2005.

Results. Thinking about risk by analysing the chances of developing a disease is specific to complex decision‐making situations. The associated risk‐benefit analysis has to be conducted qualitatively as epidemiological risk information cannot know all details of a woman’s life. In addition, a woman’s decision is based on the perception of the condition as risk or as disease. Women are willing to treat risk that is perceived as disease, especially when it is based on bodily measurements on which the treatment has an effect. Women are not willing to treat a risk not perceived as disease.

Conclusion. The net benefit of a treatment as calculated based on epidemiological data cannot easily be translated onto an individual’s life. Thus, the complex experience of a woman’s life at risk is highly important in decision‐making situations.

Relevance to clinical practice. The ambiguity of statistical risk estimates should be acknowledged and the women’s evaluation of her risk valued in risk treatment decision‐making.
Migration of Some Elements and Radionuclides across a Granite‐Granite Contact Zone: A Natural Analogue for Safe Disposal of High‐Level Radwastes
Authors: Xingzhang LUO , Maozhong MIN , Guanghui ZHANG , Xianguo LI , Zhe YANG , Liying ZHAI , Deling Zhu
Published: November 2010

Abstract Elements and natural radionuclides in the contact zone of two granites with different ages would migrate from one to the other because of the difference in their chemical contents and later water‐rock interactions. This migration could serve as an analogue for the near‐field process of radwastes in a high‐level radwaste deep geological disposal repository.

In the contact between the Indosinian granite (whole‐rock Rb‐Sr isochron age at 214±3 Ma) and Hercynian granite (zircon U‐Pb isochron age at 296±31 Ma) located in Ziyuan County, Guangxi, the O and Pb isotope characteristics and the activity ratios of 234U/238U, 230Th/238U, 230Th/234U and 226Ra/230Th show that, based on the whole‐rock chemical contents, both of the two granites have maintained a relatively open chemical system in their evolution processes. However, as there is no obvious open fault, the migration of major elements, trace elements and natural U‐series nuclides takes place within only 1–2 m in the contact zone, and water‐rock interactions in the weak contact plane only affect the redistribution of chemical constituents at a distance of 30 cm.

Fractures are the pathways for fluid flow. In term of uranium‐series disequilibrium and the radionuclide data (the abnormally high value of 234U/238U=4.60 in the fracture sample), significant water‐rock interactions could cause the bordering rocks to be altered and leach some radionuclides out. U and Ra migrated selectively at the time scale of 106 a and 104a, respectively, but the redistribution of granite is only within 10 cm from the contact, and Th seems to be immobile. On the other hand, clay‐enriched fillings in the fractures can adsorb most of the leached radionuclides. The adsorption could significantly retard radionuclide migration in the fractures, but its influence in distance is less than 10 cm from the fracture plane. The present data could be viewed as evidence for safety confidence for the high‐level radwaste disposal repositories hosted by granitic rocks in China.
Mineralization and Ore‐controlling Implications of Low‐angle Faults
Authors: Bailin CHEN , Jianmin LIU , Da ZHANG , Jianshe WU
Published: November 2010

Abstract Low‐angle faults include those occurring in thrust‐nappe structures in a compressive setting and the detachment of metamorphic core complexes in an extensional setting. All low‐angle faults have their own particularities. The low‐angle fault plays an important role in controlling over some endogenetic metallic ore deposits. Based on studies of the Xiaoban gold deposit, Xinzhou gold deposit, and Longfengchang polymetallic ore deposit, and comparisons with other mines, the authors conclude the ore‐controlling implications of low‐angle faults as follows. (1) Because of high temperature and high pressure, as well as strong ductile deformation, the internal energy of the elements rises in the large‐scale deep ductile low‐angle faults, which causes the elements to activate and differentiate from the source rocks, forming ore‐bearing hydrothermal solution, and bring mineralization to happen. (2) When rising from depths and flowing along the low‐angle faults, the ore‐bearing hydrothermal solution will alter and replace the tectonites in the fault zone. The rocks of the hanging side and the heading side differ in lithology, texture and structure, which results in changes or dissimilarities of the physical‐chemical conditions. This destroys the balance of the hydrothermal solution system and causes the dissolved ore‐forming elements to precipitate; as a result, a deposit is formed. Therefore, the meso‐shallow ductile‐brittle low‐angle faults play the role of a geochemical interface in the process of mineralization. (3) Low‐angle faults are often one of the important host structures.
Biodegradation of Benzene and Toluene under Enhanced Denitrifying Conditions
Authors: Yucheng WU , Zuoxin ZHONG
Published: November 2010

Abstract The biodegradation of benzene and toluene was studied by aquifer material microcosm experiment in laboratory under enhanced denitrifying conditions. Based on analyses and contrast of the experiment results, the following important conclusions were obtained. Microorganisms can utilize nitrate as the electron acceptor to degrade benzene and toluene under enhanced denitrifying conditions. The denitrifiers come from the aquifer material. The macro‐nutrient that microorganisms need is provided by benzene, toluene and nitrate, and the trace elements come from the aquifer material. Environmental conditions have great effects on the biodegradation of benzene and toluene, and the pH values strongly inhibit the biodegradation when they are too high or too low.
Characteristics of Upper Mantle Activity in the South China Sea Region and the Indochina Mantle Plume
Authors: Nengyou WU , Weijun ZENG , Zhenwu LI , Yizhong CHEN , Xiwen WEN , Deli DU , Guosheng LI
Published: November 2010

Abstract According to computed results of the mantle traction field beneath the lithosphere based on satellite‐modelled gravity anomalies of different degrees, it has been revealed that the three types of mantle convection on different scales existing in the South China Sea region is the key factor controlling the geodynamics. The mantle convection models on large and middle scales have been proved by natural seismic S‐wave tomographic data and interpreted by using the present mantle plume concept. In consideration of other relevant geological and geophysical data, the authors put emphasis on discussing the expression form, origin and age of the Indochina mantle plume and its important effect on the conversion of organic matter and hydrocarbon accumulation in Cenozoic basins.
A New Vetulicolian from the Early Cambrian Chengjiang Fauna in Yunnan of China
Authors: Ailin CHEN , Hongzhen FENG , Maoyan ZHU , Dongsheng MA , Ming LI
Published: November 2010

Abstract  The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain‐formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive “atrial cavity” and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.
Pediculate Brachiopod Diandongia pista from the Lower Cambrian of South China
Authors: Zhifei ZHANG , Jian HAN , Xingliang ZHANG , Jianni LIU , Degan SHU
Published: November 2010

Abstract  The Chengjiang Lagerstätte has been celebrated for prolific soft‐bodied fossils. Based on specimens recently excavated in the Chengjiang Lagerstätte by the Early Life Institute, Northwest University, Diandongia pista Rong, 1974, is directly revealed to be a pediculate brachiopod, assigned to the Family Botsfordiidae, as is further confirmed by the exceptionally preserved vascular system including dorsal and ventral mantle canals. These specimens described herein exhibit some peculiarities, notably the extremely thin and long pedicles, which suggest that Diandongia is epifaunal rather than burrowing brachiopod. A study of this group of animals indicates that they may be vital to understand the relationship between the lingulids and the remaining brachiopods, and the character evolution of the early Cambrian brachiopods.
Pygostyle‐like Structure from Beipiaosaurus (Theropoda, Therizinosauroidea) from the Lower Cretaceous Yixian Formation of Liaoning, China
Authors: Xing XU , Yennien CHENG , Xiaolin WANG , Chunhsiang CHANG
Published: November 2010

Abstract  Pygostyle was previously considered as a unique structure of ornithothoracine birds, used to maneuver tail feathers. A similar structure from an oviraptorosaurian dinosaur was considered functionally associated with the rectrices as in birds. We report a pygostyle‐like structure from a therizinosauroid dinosaur. The presence of filamentous integuments, but absence of rectrices, on the tail of this therizinosauroid, combined with other lines of evidence, suggests that the initial function of the pygostyle was not related to the rectrices.
The Discovery of Diamond from the Zhimafang Pyrope Peridotite of the Sulu UHP Metamorphic Zone, East China, and Its Geological Implications
Authors: Mingbao PAN , Qinglong ZHANG , Huafu LU , Huogen CHEN , Shouju CHEN , Shipeng ZHU
Published: November 2010

Abstract  From Donghai County of Jiangsu Province to Rongcheng County of Shandong Province on the southern border of the Sulu orogen, there exposes an ultramafic belt, accompanied with an ultrahigh‐pressure metamorphic zone. It can be further divided into the Xugou belt (the northern belt), and the Maobei‐Gangshang belt (the southern belt). One grain of diamond has been discovered from the Zhimafang pyrope peridotite in the southern belt using the heavy mineral method. The diamond grain is 2.13 mm × 1.42 mm × 0.83 mm in size and weighs 9.4 mg. The occurrence of the diamond suggests that the Zhimafang pyrope peridotite xenolith is derived from the lithospheric upper mantle. The tectonic emplacement mechanism of the pyrope peridotite xenoliths in granite‐gneisses is obviously different from those in kimberlite. The Sulu orogen was located on the active continental margin of the Sino‐Korean craton in the Neoproterozoic. The relatively cold and water‐bearing oceanic crustal tholeiite slab subducted beneath the lithospheric mantle of the Sino‐Korean craton, and partly melted to produce granitic magma and water‐bearing fluids. The magma and fluids pierced through and fractured the overlying lithospheric mantle, and ascended to the crustal level together with the ultramafic mantle fragments as xenoliths.
Carboniferous Post‐collisional Rift Volcanism of the Tianshan Mountains, Northwestern China
Authors: Linqi XIA , Xueyi XU , Zuchun XIA , Xiangmin LI , Zhongping MA , Lishe WANG
Published: November 2010

Abstract  The Tianshan Carboniferous post‐collisional rift volcanic rocks occur in northwestern China as a large igneous province. Based on petrogeochemical data, the Tianshan Carboniferous post‐collisional rift basic lavas can be classified into two major magma types: (1) the low‐Ti/Y type situated in the eastern‐central Tianshan area, which exhibits low Ti/Y (<500), Ce/Yb (<15) and SiO2 (43–55%), and relatively high Fe2O3T (6.4–11.5%); (2) the high‐Ti/Y type situated in the western Tianshan area, which has high Ti/Y (>500), Ce/Yb (>11) and SiO2 (49–55%), and relatively low Fe2O3T (5.8–7.8%). Elemental data suggest that chemical variations of the low‐Ti/Y and high‐Ti/Y lavas cannot be explained by fractional crystallization from a common parental magma. The Tianshan Carboniferous basic lavas originated most likely from an OIB‐like asthenospheric mantle source (87Sr/86Sr(t) ∼ 0.703–0.705, εNd(t) ∼ +4 to +7). The crustal contamination and continental lithospheric mantle have also contributed significantly to the formation of the basic lavas of the Tianshan Carboniferous post‐collisional rift. The silicic lavas were probably generated by partial melting of the crust. The data of this study show that spatial petrogeochemical variations exist in the Carboniferous post‐collisional rift volcanics province in the Tianshan region. Occurrence of the thickest volcanics dominated by tholeiitic lavas may imply that the center of the mantle‐melting anomaly (mantle plume) was in the eastern Tianshan area at that time. The basic volcanic magmas in the eastern Tianshan area were generated by a relatively high degree of partial melting of the mantle source around the spinel‐garnet transition zone, whereas the alkaline basaltic lavas are of the dominant magma type in the western Tianshan area, which were generated by a low degree of partial melting of the mantle source within the stable garnet region, thus the basic lavas of the western Tianshan area might have resulted from relatively thick lithosphere and low geothermal gradient.
Biogenic Accumulations of Uranium in Recent Seas
Authors: ALİYEV Saday Azadoǧlu , SARI Ali
Published: November 2010

Abstract  The objective of this study is to determine the geochemical role of molluscs in the distribution of uranium in the marine ecosystem. Biogeochemical studies are carried out on recent mollusc shells from the Caspian Sea, Sea of Japan, Sea of Marmara, Aegean Sea, Black Sea, Mediterranean Sea, Baltic Sea, and Indian Ocean, which differ from each other in terms of physical, chemical, geographic, and geochemical characteristics. In this study, nine Gastropoda and fifty‐four Pelecypoda shells of different species are analyzed to document variations of uranium in seasonal layers, which were formed by the seasonal carbonate‐organic phase of molluscs during their entire lives. Shell used in this study principally comprises three layers: upper (outer) prismatic, middle prismatic, and inner (mother‐of‐pearl) layers. In addition, when possible, the head, the middle, and the lower parts of the shells are used for analyses separately. Also, the biological accumulation rate values for each different mollusc species relative to the average uranium value in seawater are calculated. The BAR values of U in mollusc shells range between 11 and 216. Uranium concentrations in recent mollusc shells vary between 0.034 ppm and 0.65 ppm. Organic carbon values vary between 1100 and 9700 ppm in various mollusc species. The uranium and Corg concentrations in living mollusc shells are positively correlated. Both the uranium and Corg contents in mollusc shells are preferably dependent on the taxonomic characteristics of organisms. It has been observed that the uranium concentrations in the mineral‐organic phase of molluscs are in good agreement with those of surrounding sediments. Therefore, the changes in the uranium concentrations in shell and sediment types are derived from the uranium concentrations in water.
Development of Overpressure in the Tertiary Damintun Depression, Liaohe Basin, Northern China
Authors: Jiaren YE , Fang HAO , Jianyu CHEN
Published: November 2010

Abstract  The Damintun depression is one of the four depressions in the Liaohe basin in northern China, and is a rift basin developed in the Paleogene. This paper discusses in detail the characteristics of pressure and fluid potential of the Damintun depression based on a synthesis of the data from boreholes, well tests and seismic surveys. Data from sonic logs, well tests and seismic velocity measurements are used to study the pressure characteristics of the areas. From the sonic log data, shales can be characterized as normally pressured, slightly overpressured or highly overpressured; from the well test data, the pressure‐depth gradient in oil‐producing intervals implies hydrostatic pressure in general. Most seismic profiles in the Damintun depression are of sufficiently high quality for seismic velocities to be measured. The fluid pressures, excess pressures and pressure coefficients in 47 representative seismic profiles are predicted using formula calculation methods, and further transformed to fluid potentials. The resultant pressure profiles show normal pressure, moderate overpressure and intense overpressure increasing with depth. The pressure evolution can be divided into three stages as initial generation, partial dissipation and re‐accumulation. Fluid potential is the principal factor controlling hydrocarbon migration in a reservoir. Its distribution varies with depth; above the T4 interface a gravity‐flow dominates, whereas beneath it a compaction flow dominates. The development of overpressure in the Damintun depression has a crucial influence on the distribution of fluid potentials, which agrees with that of overpressure in general. The results of the fluid potential analysis indicate that the areas of Dongshenpu‐Xinglongpu and the southwestern part of the depression are most favorable for hydrocarbon migration and accumulation.
The use of Shoulder Ultrasound in a One-Stop Clinic: Diagnostic Accuracy for Rotator Cuff Tear and Biceps Tendon Pathology
Authors: Cowling Paul , Gamble Alison , Rangan Amar
Published: November 2010

Background

Ultrasonography is useful in diagnosing rotator cuff tears in one-stop shoulder clinics. The present study aimed to investigate one-stop shoulder clinic ultrasonographic accuracy when diagnosing rotator cuff tears and their size, as well as long head of biceps (LHB) tendon pathology.

Methods

One hundred and twenty-two patients who underwent shoulder arthroscopy following pre-operative ultrasonography in a one-stop shoulder clinic were analyzed retrospectively.

Results

Partial thickness cuff tears were detected with a sensitivity and specificity of 65.0% and 94.0%, respectively, and full thickness tears at 94.8% and 93.8%, respectively. Full thickness tears were further analyzed as small tears, (<1 cm), with a sensitivity and specificity of 50.0% and 96.6%, respectively; moderate (1 cm to 3 cm), at 88.5% and 93.8%, respectively; and large/massive tears (>3 cm) at 73.1% and 99.0%, respectively. LHB pathology diagnosis sensitivity and specificity was 62.5% and 100%. Further analysis revealed a sensitivity and specificity of LHB dislocation of 83.3% and 100%, respectively, and rupture of 61.1% and 99.0%, respectively.

Conclusions

This is the first study to report shoulder ultrasonographic accuracy at a one-stop clinic when investigating cuff tear size and LHB pathology. Ultrasonography at a one-stop clinic is a cost-effective accurate method of managing patients with shoulder pathology.
Phosphodiesterase 4 inhibition attenuates atrial natriuretic peptide‐induced vascular hyperpermeability and loss of plasma volume
Authors: Lin Yueh‐Chen , Samardzic Haris , Adamson Roger H. , Renkin Eugene M. , Clark Joyce F. , Reed Rolf K. , Curry Fitz‐Roy E.
Published: November 2010

Non‐technical summary

Natriuretic peptides (such as atrial natriuretic peptide, ANP) are normally present at very low levels in the blood and are part of physiological systems that control blood volume. During diseases such as heart failure and sepsis, circulating levels of ANP increase, leading to an increase in blood vessel permeability and loss of blood fluid volume to the tissues. Other studies show that some inflammatory responses are strongly blocked by increased intracellular cAMP. Here we tested whether rolipram, an inhibitor of the degradation of cAMP, could counteract the movement of protein and fluid out of the blood that is induced by ANP. We found that rolipram almost completely blocked the ANP‐induced loss of blood volume. Stabilizing the endothelial barrier by controlling cAMP levels to offset ANP‐induced increases in vascular permeability may be part of a strategy to maintain plasma volume in disease states with elevated natriuretic peptides.
Cramer–Rao Bound Development for Linear Time Periodic Systems
Authors: Schulz Chris S. , Kunz Donald L. , Wereley Norman M.
Published: November 2010

System identification techniques are often used to determine the parameters required to define a model of a linear time invariant (LTI) system. The Cramer–Rao bound can be used to validate those parameters in order to ensure that the system model is an accurate representation of the system. Unfortunately, the Cramer–Rao bound is only valid for LTI systems and is not valid for linear time periodic (LTP) systems such as a helicopter rotor in forward flight. This paper describes an extension of the Cramer–Rao bound to LTP systems and demonstrates the methodology for a simple LTP system.
Stall Warning in a Low-Speed Axial Fan by Visualization of Sound Signals
Authors: Sheard Anthony G. , Corsini Alessandro , Bianchi Stefano
Published: November 2010

This study describes the development of a novel stall-detection methodology for low-speed axial-flow fans. Because aerodynamic stall is a major potential cause of mechanical failure in axial fans, effective stall-detection techniques have had wide application for many years. However, aerodynamic stall does not always result in mechanical failure. A subsonic fan can sometimes operate at low speeds in an aerodynamically stalled condition without incurring mechanical failure. To differentiate between aerodynamic stall conditions that constitute a mechanical risk and those that do not, the stall-detection methodology in the present study utilizes a symmetrized dot pattern (SDP) technique that is capable of differentiating between stall conditions. This paper describes a stall-detections criterion based on a SDP visual waveform analysis and develops a stall-warning methodology based on that analysis. This study presents an analysis of measured acoustic and structural data across nine aerodynamic operating conditions represented in a 3×3 matrix. The matrix is a combination of (i) three speeds (full-, half-, and quarter-speed) and (ii) three operational states (stable operation, incipient stall, and rotating stall). The matrix of SDPs and structural data are used to differentiate critical stall conditions (those that will lead to mechanical failure of the fan) from noncritical ones (those that will not result in mechanical failure), thus providing a basis for an intelligent stall-warning methodology.
Stress Relaxation of a Twaron®/Natural Rubber Composite
Authors: David N. V. , Gao X.-L. , Zheng J. Q.
Published: November 2010

The stress relaxation behavior of a Twaron CT709® fabric/natural rubber composite under a uniaxial constant strain is studied using three viscoelasticity models with different levels of complexity and a newly developed para-rheological model. The three viscoelasticity models employed are a one-term generalized Maxwell model (comprising one Maxwell element and an additional spring in parallel), a two-term generalized Maxwell model (including two Maxwell elements and an additional spring in parallel), and a four-parameter Burgers model. The values of the parameters involved in each model are extracted from the experimental data obtained in this study. The stress relaxation tests reveal that the stress starts to decay exponentially for a short duration and then continues to decrease linearly with time. It is found that the initial relaxation response of the composite is predicted fairly well by all of the four models, while the long-time stress relaxation behavior is more accurately predicted by the para-rheological model. The accuracy of each model in describing the stress relaxation behavior of the composite is quantitatively compared.
Virtual Testing for Advanced Aerospace Composites: Advances and Future Needs
Authors: Yang Q. D. , Cox Brian N. , Fang X. J. , Zhou Z. Q.
Published: November 2010

In this paper, the conceptual, experimental, and computational challenges associated with virtual testing have been discussed and recent advances that address these challenges have been summarized. The promising capability of augmented finite element method based numerical platform for carry out structural level, subply scale, and microscopic single-fiber level analyses with explicit consideration of arbitrary cracking has been demonstrated through a hierarchical simulation-based analysis of a double-notched tension test reported in the literature. The simulation can account for the nonlinear coupling among all major damage modes relevant at different scales. Thus, it offers a complete picture of how microdamage processes interact with each other to eventually form a catastrophic major crack responsible for structural failure. In the exercise of virtual testing, such information is key to guide the design of discovery experiments to inform and calibrate models of the evolution processes. Urgent questions derived from this exercise are: How can we assure that damage models address all important mechanisms, how can we calibrate the material properties embedded in the models, and what constitutes sufficient validation of model predictions? The virtual test definition must include real tests that are designed in such a way as to be rich in the information needed to inform models and must also include model-based analyses of the tests that are required to acquire the information. Model-based analysis of tests must be undertaken and information-rich tests must be defined, taking proper account of the limitations of experimental methods and the stochastic nature of sublaminar and microscopic phenomena.
Frequency-Steered Acoustic Arrays: Application to Structural Health Monitoring of Composite Plates
Authors: Xu Buli , Senesi Matteo , Ruzzene Massimo
Published: November 2010

This paper presents the design, characterization, and application of periodic piezoelectric actuator arrays for structural health monitoring. In the proposed array configuration, all elements are activated simultaneously to achieve strong frequency-dependent directional actuation, which allows beam steering through a sweep of the excitation frequency and limited hardware requirements. The array enables in situ monitoring of critical components through strongly focused actuation and directional scanning capabilities. The concept is illustrated for a selected design with quadrilateral topology on an isotropic plate. The application to composite panels is also specifically discussed by illustrating the complexity of the corresponding dispersion properties, which suggest design challenges for mode tuning. A quadrilateral design is tested for excitation of the A0 mode on a selected lay-up sequence to illustrate the generality of the proposed concept and its applicability to composites.
Combustion of Apple Juice Wastes in a Cyclone Combustor for Thermal Energy Generation (ES2009-90152)
Authors: Virmond Elaine , Schacker Robson L. , Albrecht Waldir , Althoff Christine A. , de Souza Maurício , Moreira Regina F. P. M. , José Humberto J.
Published: November 2010

The solid waste generated from the apple juice industry (apple bagasse (AB)) was characterized as a fuel, and the potential for its utilization as an alternative energy source was assessed through its combustion in a pilot scale cyclone combustor. A comparative evaluation of the AB and sawdust (SD) properties, as well as of the emissions during the combustion tests, was performed. The high energy content of AB (lower heating value (LHV) equal to 21.09 MJ kg−1), dry and ash-free (daf) basis, which is 26.9% higher than the LHV of SD (16.62 MJ kg−1, daf), and combined with the high volatile matter content (85.36 wt %, daf) improve the ignition and burning of the solids. The emissions of CO, SO2, and NOx and the total organic carbon (TOC) were compared with guideline limits established by Brazilian and international legislation. AB generated much lower CO than sawdust in spite of almost half of excess air levels (13% compared with 26%) and met even the stringent limit of the German regulation for waste incineration. The unburned carbon percentages found in the ash resulted from SD and AB combustion tests were 0.24% and 0.96% in weight, respectively. The absence of sulfur in AB composition represents an advantage with nondetectable SO2. The average level of NOx emission with SD combustion was 242 mg N m−3 and met all the regulation limits. The average NOx emission with AB combustion though was 642 mg N m−3 and met the U.S. EPA regulation but was marginally higher than the Brazilian norm by 15%. TOC concentrations remained below the limits considered even though the TOC level was higher in the AB combustion test. Polycyclic aromatic hydrocarbons (PAH) were not detected or were under the quantification limit of the equipment used in their analysis. Comparing the properties, the burning profiles of SD and AB, and the emissions from their combustion tests, it can be stated that the waste originating from the apple juice industry is suitable for direct combustion, constituting a renewable energy source for this industrial sector.
Topology and Constraint Analysis of Phase Change in the Metamorphic Chain and Its Evolved Mechanism
Authors: Zhang Ketao , Dai Jian S. , Fang Yuefa
Published: November 2010

This paper presents a metamorphic kinematic pair extracted from origami folds in the context of mechanisms, its evolved metamorphic chain, and the novel metamorphic parallel mechanism. This paper starts from the generic issues of topological representation for metamorphic mechanism, leading to unified elementary matrix operation for presentation of topological variation. Phase matrix and augmented adjacency matrix are developed to present the topological state and geometry of metamorphic mechanism in an evolutionary process. The metamorphic kinematic pair has the ability of changing mobility to generate different motion patterns based on mobility change correlated with the link annex induced topological phase change. This paper then investigates topological variation of the metamorphic chain and the topological subphases are enumerated in accordance with structure evolution. Using the metamorphic chain as chain-legs, a multiloop metamorphic mechanism with ability of performing phase change and orientation switch is constructed. The disposition of constraints and geometric constraints induced bifurcated motion are analyzed based on screw theory. The topological variation of the metamorphic parallel mechanism is addressed and the foldability is verified by physical device.
Series Solution for Finite Displacement of Planar Four-Bar Linkages
Authors: Milenkovic Paul
Published: November 2010

A time-varying instantaneous screw characterizes the motion of a rigid body. The kinematic differential equation expresses the path taken by any point on that rigid body in terms of this screw. Therefore, when a revolute joint is attached to a moving link in a planar kinematic chain, the path taken by the center of that revolute joint is the solution to such an equation. The instantaneous screw of a link in that chain is in turn determined by the action of the joints connecting that link to ground, where the contribution of each joint to that instantaneous screw is determined by its actuation rate and center point. Substituting power series expansions for joint rates into the kinematic differential equations for joint centers, and expressing loop closure as a linear constraint on the instantaneous screws of the links, a recurrence relation is established that solves for the coefficients in those power series. The resulting solution is applied to determine the equilibrium pendulum tilt of the United Aircraft TurboTrain. Comparing that power series approximation with an exact kinematic analysis shows convergence properties of the series.
Optimal Trajectory Generation With Probabilistic System Uncertainty Using Polynomial Chaos
Authors: Fisher James , Bhattacharya Raktim
Published: November 2010

In this paper, we develop a framework for solving optimal trajectory generation problems with probabilistic uncertainty in system parameters. The framework is based on the generalized polynomial chaos theory. We consider both linear and nonlinear dynamics in this paper and demonstrate transformation of stochastic dynamics to equivalent deterministic dynamics in higher dimensional state space. Minimum expectation and variance cost function are shown to be equivalent to standard quadratic cost functions of the expanded state vector. Results are shown on a stochastic Van der Pol oscillator.
Exponential Delay Dependent Stabilization for Time-Varying Delay Systems With Saturating Actuator
Authors: Liu Pin-Lin
Published: November 2010

This paper deals with the stabilization criteria for a class of time-varying delay systems with saturating actuator. Based on the Lyapunov–Krasovskii functional combining with linear matrix inequality techniques and Leibniz–Newton formula, delay-dependent stabilization criteria are derived using a state feedback controller. We also consider efficient convex optimization algorithms to the time-varying delay system with saturating actuator case: the maximal bound on the time delay such that the prescribed level of operation range and imposed exponential stability requirements are still preserved. The value of the time-delay as well as its rate of change are taken into account in the design method presented and further permit us to reduce the conservativeness of the approach. The results have been illustrated by given numerical examples. These results are shown to be less conservative than those reported in the literature.
Experimental Investigation of Chain Link Forces in Continuously Variable Transmissions
Authors: De Novellis L. , Carbone G.
Published: November 2010

This paper deals with the experimental analysis of link tension distribution in a chain type continuously variable transmission. We have developed an ad hoc measuring device constituted by a data-logger that is fixed at the chain and moves with it. The data-logger records the strain data from a strain gauge and stores them in a flash memory card. We have been able to measure the tensile force acting on a single chain link in a wide range of working conditions. Our measurements have shown that an almost perfect linearity (which has a clear theoretical explanation) exists between the clamping force and the link tension distribution. We have also found that the link tension distribution is less sensitive to the torque load, which mainly influences the local slip between the chain and the pulley and hence the time required by the link to cover the entire contact arc. We have also carried out a comparison between theoretical predictions and experimental data. We have found a relatively good agreement that confirms the validity of the theoretical approach.
A Computationally Assisted Methodology for Preference-Guided Conceptual Design
Authors: Barnum Garrett J. , Mattson Christopher A.
Published: November 2010

We present an interactive, computationally assisted, methodology for capturing and incorporating designer preferences into a numerical search for design concepts. An initial pool of manually created designs is parameterized and used in a computational search that recombines features to form new designs in a semi-automated way. Designs are evaluated quantitatively by performance calculations and evaluated qualitatively by human designers. Designer preference is captured when visual representations of designs are presented to the designer for subjective evaluation. The methodology searches for optimally performing designs, guided by quantitative performance models and designer preferences. The methodology couples the speed of computational searches with the ability of human designers to subjectively evaluate unmodeled objectives. The new methodology is demonstrated with a vehicle architecture example, which generates a set of designs that progressively improves in performance and more fully meets designer preference. The proposed method brings the ability to generate numerous, optimally performing solutions across a wide solution space, in an efficient and human-centered way, and does so in the early stages of design.
Innovative Interactive Lecture Demonstrations Using Wireless Force Sensors and Accelerometers for Introductory Physics Courses
Authors: Yoder G. , Cook J.
Published: November 2010

Interactive lecture demonstrations1–6 (ILDs) are a powerful tool designed to help instructors bring state-of-the-art teaching pedagogies into the college-level introductory physics classroom. ILDs have been shown to improve students' conceptual understanding, and many examples have been created and published by Sokoloff and Thornton.6 We have used the new technology of Vernier's Wireless Dynamics Sensor System (WDSS)7 to develop three new ILDs for the first-semester introductory physics (calculus-based or algebra-based) classroom. These three are the Force Board, to demonstrate the vector nature of forces, addition of vectors, and the first condition of equilibrium; the Torque Board, to demonstrate torque and the second condition for equilibrium; and the Circular Motion Board, to discover the nature of the acceleration an object exhibiting uniform circular motion. With the WDSS, all three of these ILDs are easy to set up and use in any classroom or laboratory situation, and allow more instructors to utilize the technique of interactive lecture demonstrations.