bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design a Biologically Inspired Nanostructured Coating for Better Osseointegration
Authors: Wang Mian , Li Jian , Keidar Michael , Zhang Lijie Grace 
Published: March 2012

ABSTRACTTo date, there are a strikingly growing number of patients who need various orthopedic implants. However, traditional orthopedic implants face many complications such as infection and implant loosening which may lead to implant failures. Conventional metal implants such as titanium were chosen for orthopedic applications mainly based on their excellent mechanical properties and biological inertness. Since natural bone matrix is nanometer in dimension, it is desirable to design a biologically inspired nanostructured coating that can turn conventional inert titanium surfaces into biomimetic active interfaces, thus enhance bone cell adhesion and osseointegration. For this purpose, we designed a biomimetic nanostructured coating based on nanocrystalline hydroxyapatites (nHA) and single wall carbon nanotubes (SWCNTs). Specifically, nHA with good crystallinity and biomimetic dimensions were prepared via a wet chemistry method and hydrothermal treatment; and the SWCNTs were synthesized via an arc plasma method with or without magnetic fields. TEM images showed that the hydrothermally treated nHA possessed regular rod-like nanocrystals and biomimetic nanostructure. In addition, the length of SWCNTs can be significantly increased under external magnetic fields when compared to nanotubes produced without magnetic fields. More importantly, our results showed that the above nHA and SWCNTs nanomaterials can greatly promote osteoblast (bone-forming cell) adhesion on titaniumin vitro, thus holding great promise to improve osseointegration and lengthen the lifetime of current orthopedic implants.
Failure of bone at the sub-lamellar level usingin situAFM-SEM investigations
Authors: Jimenez-Palomar Ines , Barber Asa H. 
Published: March 2012

ABSTRACTIn this paper we examine the mechanical properties of individual lamellae from bone material using novel atomic force microscopy (AFM)-scanning electron microscopy (SEM) techniques. Individual lamellar beams were selected from bone using focussed ion beam (FIB) microscopy and mechanically deformed with the AFM while observing failure modes using SEM. Both the elastic and fracture behavior of the bone lamellae were determined using these techniques.
Activation Energy and Blistering Rate in Hydrogen-implanted Semiconductors
Authors: Pyke Daniel J. , Elliman Robert G. , McCallum Jeffrey C. 
Published: March 2012

ABSTRACTHydrogen blister rates in Si (100), Si (111) and Ge (100) substrates are compared as a function of annealing temperature and time, for a range of implant energies and fluences. For each material, the rate of blister formation was found to exhibit Arrhenius behavior and to be characterised by a single activation energy over the temperature range examined. The extracted activation energies were 2.28±0.03 eV, 2.17±0.06 eV and 1.4±0.03 eV for (100) Si; (111) Si and (100) Ge, respectively. These results are compared with reported measurements and discussed in relation to proposed models of hydrogen blistering.
Dielectric Gradient Force Actuation with on-chip electrode and Free-Space Optical Measurement of SiNx Nanomechanical Resonator
Authors: Cho Sungwan , Cho Myung Rae , Shim Seung-Bo , Park Yun Daniel 
Published: March 2012

ABSTRACTNanomechanical resonators made from silicon nitride with residual stress is actuated using dielectric field gradient force. Doubly clamped nanomechanical resonators are made from SiNx-SiO2-Si tri-layer substrate and DC electric field induces a temporary dipole moment while a small AC electric field drives beam resonator by dielectric force. Realized nanomechanical resonators show resonant motion of high resonant frequency (up to ~31 Mhz) and mechanical quality factor up to over 48,000 at room temperature and moderate vacuum condition. From the FEA (Finite Element Analysis) of resonant motion, doubly clamped resonator shows torsional motion and in-plane motion which can be assigned to additional multiple modes in resonant response measurement
Water Concentration Influence on Catalytic Growth of Carbon Nanotubes in a Suspended Bed Reactor
Authors: Mordkovich V.Z. , Karaeva A.R. , Khaskov M.A. , Solomonik I.G. , Mitberg E.B. , Kulnitskiy B.A. , Perezhogin I.A. 
Published: March 2012

ABSTRACTOne of the most important problems in the synthesis of carbon nanotubes is the problem of controlling their morphology, namely: length, aspect ratio, alignment, etc. Catalytic synthesis of carbon nanotubes in a suspended bed reactor allowed to study the possibilities of controlling the growth of nanotubes by introducing a certain amount of water vapor and carbon-containing materials in the reaction zone. The synthesized long carbon nanotubes were studied by Raman spectroscopy, transmission and scanning electron microscopy. We found that water concentration influences both yield and the structure of nanotubes. It is shown that the yield of centimeter-long nanotubes can be maximized at an optimum H2O/C ratio, while deviations dramatically change morphology and thickness of the nanotubes.
Environmental and biological controls on the diversity and ecology of Late Cretaceous through early Paleogene marine ecosystems in the U.S. Gulf Coastal Plain
Authors: Sessa Jocelyn A. , Bralower Timothy J. , Patzkowsky Mark E. , Handley John C. , Ivany Linda C. 
Published: March 2012

The late Mesozoic through early Cenozoic is an interval of significant biologic turnover and ecologic reorganization within marine assemblages, but the timing and causes of these changes remain poorly understood. Here, we quantify the pattern and timing of shifts in the diversity (richness and evenness) and ecology of local (i.e., sample level) mollusk-dominated assemblages during this critical interval using field-collected and published data sets from the U.S. Gulf Coastal Plain. We test whether the biologic and ecologic patterns observed primarily at the global level during this time are also expressed at the local level, and whether the end-Cretaceous (K/Pg) mass extinction and recovery moderated these trends. To explore whether environment had any effect on these patterns, we examine data from shallow subtidal and offshore settings.Assemblages from both settings recovered to pre-extinction diversity levels rapidly, in less than 7 million years. Following initial recovery, diversity remained unchanged in both settings. The trajectory of ecological restructuring was distinct for each setting in the wake of the K/Pg extinction. In offshore assemblages, the abundance and number of predatory carnivorous taxa dramatically increased, and surficial sessile suspension feeders were replaced by more active suspension feeders. In contrast, shallow subtidal assemblages did not experience ecological reorganization following the K/Pg extinction. The distinct ecological patterns displayed in each environment follow onshore-offshore patterns of innovation, whereby evolutionary novelties first appear in onshore settings relative to offshore habitats. Increased predation pressure may explain the significant ecological restructuring of offshore assemblages, whereby the explosive radiation of predators drove changes in their prey. Habitat-specific ecological restructuring, and its occurrence solely during the recovery interval, implies that disturbance and incumbency were also key in mediating these ecological changes.
Advance Care Planning in CKD/ESRD
Authors: Holley Jean L. 
Published: March 2012

Summary
Advance care planning was historically considered to be simply the completion of a proxy (health care surrogate designation) or instruction (living will) directive that resulted from a conversation between a patient and his or her physician. We now know that advance care planning is a much more comprehensive and dynamic patient-centered process used by patients and families to strengthen relationships, achieve control over medical care, prepare for death, and clarify goals of care. Some advance directives, notably designated health care proxy documents, remain appropriate expressions of advance care planning. Moreover, although physician orders, such as do-not-resuscitate orders and Physician Orders for Life-Sustaining Treatment, may not be strictly defined as advance directives, their completion, when appropriate, is an integral component of advance care planning. The changing health circumstances and illness trajectory characteristic of ESRD mandate that advance care planning discussions adapt to a patient’s situation and therefore must be readdressed at appropriate times and intervals. The options of withholding and withdrawing dialysis add ESRD-specific issues to advance care planning in this population and are events each nephrologist will at some time confront. Advance care planning is important throughout the spectrum of ESRD and is a part of nephrology practice that can be rewarding to nephrologists and beneficial to patients and their families.
Association of Statin Use with Risk and Outcome of Acute Kidney Injury in Community-Acquired Pneumonia
Authors: Murugan Raghavan , Weissfeld Lisa , Yende Sachin , Singbartl Kai , Angus Derek C. , Kellum John A. 
Published: March 2012

Summary

Background and objectives
Sepsis is a leading cause of AKI. Animal studies suggest that the pleiotropic effect of statins attenuates the risk for AKI and decreases mortality. This study examined whether statin use was associated with a lower risk for pneumonia-induced AKI and 1-year and cause-specific mortality in patients with AKI.

Design, setting, participants, & measurements
Multicenter, prospective cohort study of 1836 patients hospitalized with community-acquired pneumonia.

Results
Baseline characteristics differed among statin users and nonusers. Of the 413 patients (22.5%) who received a statin before hospitalization, statin treatment, when adjusted for differences in age, severity of pneumonia, admission from nursing home, health insurance, and propensity for statin use, did not reduce the risk for AKI (odds ratio [OR], 1.32 [95% confidence interval (CI), 1.02–1.69]; P=0.05). Of patients with AKI (n=631), statin use was associated with a lower risk for death at 1 year (27.8% versus 38.8%; P=0.01), which was not significant when adjusted for differences in age, severity of pneumonia and AKI, use of mechanical ventilation, and propensity score (OR, 0.72 [95% CI, 0.50–1.06]; P=0.09). Among patients with AKI, cardiovascular disease accounted for one third of all deaths.

Conclusions
In a large cohort of patients hospitalized with pneumonia, statins did not reduce the risk for AKI. Among patients with AKI, statin use was not associated with lower risk for death at 1 year. The higher risk for AKI observed among statin users may be due to indication bias.
Electrocardiogram Abnormalities and Cardiovascular Mortality in Elderly Patients with CKD
Authors: Dobre Mirela , Brateanu Andrei , Rashidi Arash , Rahman Mahboob 
Published: March 2012

Summary

Background and objectives
Cardiovascular disease is the most common cause of death in CKD. This study evaluated whether electrocardiogram (ECG) abnormalities are predictors of cardiovascular death in CKD.

Design, setting, participants, & measurements
The Cardiovascular Health Study limited database (1989–2005) was used to identify a cohort with CKD at baseline (estimated GFR < 60 mL/min per 1.73 m2). The patients were categorized as having major, minor, or no ECG abnormalities. Rates of adjudicated cardiovascular events and mortality were compared among the groups using proportional hazards regression models.

Results
A total of 1192 participants had CKD at baseline; mean age ± SD was 74.7±6.2 years. Of these patients, 452 (38.8%) had major, 346 (29.7%) had minor, and 367 (31.5%) had no ECG abnormalities. Participants with estimated GFR < 60 mL/min per 1.73 m2 were more likely to have ECG abnormalities at baseline (adjusted prevalence odds ratio, 1.23 [95% confidence interval (CI), 1.06–1.43]) than those with GFR ≥ 60 mL/min per 1.73 m2. During mean follow-up of 10.3±3.8 years, 814 (68.3%) participants died. Compared with participants without ECG abnormalities, participants with major abnormalities had the highest risk for cardiovascular events and death; adjusted hazard ratios were 2.15 (95% CI, 1.56–2.98) and 2.27 (95% CI, 1.56–3.30), respectively. For minor ECG abnormalities, hazard ratios were 1.24 (95% CI, 0.91–1.70) and 1.48 (95% CI, 1.00–2.18), respectively.

Conclusions
In patients with CKD, major ECG abnormalities are frequently present and predict a significantly higher risk for death and adverse cardiovascular outcomes.
Bilateral Changes in Forearm Oxygen Consumption at Rest and After Exercise in Patients With Unilateral Repetitive Strain Injury: A Case-Control Study
Authors: Brunnekreef Jaap J.J. , Thijssen Dick H.J. , Oosterhof Jan , Hopman Maria T.E. 
Published: March 2012

Study Design Case-control study. Objectives To investigate whether oxygen consumption and blood flow at rest and after exercise are lower in the affected arm of patients with repetitive strain injury (RSI) compared to controls, and lower in the healthy nonaffected forearm within patients with unilateral RSI. Background RSI is considered an upper extremity overuse injury. Despite the local presentation of complaints, RSI may be represented by systemic adaptations. Insight into the pathophysiology of RSI is important to better understand the development of RSI complaints and to develop effective treatment and prevention strategies. Methods Twenty patients with unilateral RSI and 20 gender-matched control subjects participated in this study. Forearm muscle blood flow and oxygen consumption were measured using near-infrared spectroscopy at baseline and immediately after isometric handgrip exercises at 10%, 20%, and 40% of the individual maximal voluntary contraction. Results Unilateral RSI resulted in a lower oxygen consumption and blood flow in the affected forearm at baseline and lower oxygen consumption after incremental handgrip exercises compared to controls (P<.05). In addition, exercise-induced blood flow and oxygen consumption in the nonaffected forearm in patients with RSI were similarly reduced. Conclusion Blood flow and oxygen consumption after exercise are similarly attenuated in the affected and nonaffected arms of patients with unilateral RSI. Our findings suggest that, despite the unilateral character in clinical symptoms, RSI demonstrates systemic adaptations in forearm blood flow and oxygen consumption at rest and after exercise.
Suggestions From the Field for Return-to-Sport Rehabilitation Following Anterior Cruciate Ligament Reconstruction: Alpine Skiing
Authors: Kokmeyer Dirk , Wahoff Michael , Mymern Matt 
Published: March 2012

Synopsis Alpine skiing is a high-risk sport for injuries to the anterior cruciate ligament (ACL). While descending a hill, a skier must resist large centrifugal forces at a high velocity, while the knees are positioned in postures that place the ACL at risk of injury. Skiers who undergo ACL reconstructive surgery are prone to a high rate of reinjury to the same knee and even ACL injury in the uninjured knee. A rehabilitation program that integrates the best current evidence of ACL rehabilitation and the science of skiing is essential to a successful return to alpine skiing. Unlike rehabilitation programs developed for court or field athletes, a skiing program must place a large emphasis on slow eccentric-loading and weight-bearing (closed-chain) power and endurance. The purpose of this clinical commentary is to provide the rehabilitation specialist such a program directed toward safely returning the athlete to alpine skiing. Level of Evidence Therapy, level 5.
Keeping bats cool in the winter: hibernating bats and their exposure to ‘hot’ incandescent lamplight
Authors: Haarsma Anne‐Jifke , de Hullu Eva 
Published: March 2012

In order to monitor bat population trends, an annual census is performed of all known underground hibernacula in Europe. During these censuses, bats are sometimes found to show signs of arousal, presumably from non‐tactile stimuli caused by the observer, e.g. air currents, sound, light or an increase in temperature. We assume that heat and/or light from a torch can play a role in awaking hibernating bats. Observers use different light sources, which produce different amounts of heat. We experimentally tested the heat produced by three commonly used torches: two incandescent torches (krypton and halogen) and one LED torch. We performed the experiment on 28 January 2007 in an old brick kiln in Windesheim (Overijssel Province, the Netherlands), which is used by hibernating bats. The results show that temperatures in a crevice significantly increased when using the ‘hot’ incandescent torch types. The effect of these torches on both air and surface temperature was significant after both 10 and 30 seconds. Under the assumption that an increase of the ambient temperature by 5°C or more can cause a bat to arouse from torpor, we conclude that using ‘hot’ torches such as incandescent (halogen) lights poses a risk to the animals under study. To minimise heat disturbance from light sources, we recommend LED torches as the best available alternative.
Effect of Ti addition on the wettability of Al–B4C metal matrix composites
Authors: Kocaefe Duygu , Sarkar Arunima , Chen X-Grant 
Published: March 2012

Abstract
In this study, the wettability of B4C by molten Al, as well as Al–Ti alloys, with different Ti contents has been studied using the sessile-drop method. In general, the contact angle decreases with increasing temperature and time. The results show that an appropriate amount of Ti addition improves the wettability of B4C by Al. Analyses of the interfaces of solidified drops revealed that Al3BC and AlB2 particles form around the B4C particles when they are in contact with pure Al. However, when Ti is added to Al, AlB2 particles disappear and a new Ti-rich layer composed of TiB2 particles forms around B4C surfaces. In addition, the effect of Ti addition on the surface tension of aluminum has also been examined.
Microstructure characterization in the weld joint of a high nickel austenitic alloy and Cr18-Ni8 stainless steel
Authors: Wu Na , Li Yajiang , Wang Juan 
Published: March 2012

Abstract
High nickel austenitic alloy, 6 mm thick, and Cr18-Ni8 stainless steel with a thickness of 0.6 mm were joined by pulsed current tungsten inert gas arc welding without filler metal in this work. Metallographic examination, micro-hardness measurement and electron microprobe analysis were used to reveal microstructural characteristics in the joint. The results indicated that the weld metal consisted of γ-austenite, δ-ferrite and carbides without the appearance of martensite. There were dendrite crystals at the edge of the weld metal near the high nickel austenitic alloy and isometric crystals in the center of the weld metal. The micro-hardness of the weld metal was the highest due to the existence of carbides and its finer structure. Graphite flakes were still embedded in the austenite matrix of the heat-affected zone without the formation of martensite.
Microstructure evolution in a 2618 aluminium alloy during creep-fatigue tests
Authors: Nový František , Janeček Miloš , Král Robert , Hadzima Branislav 
Published: March 2012

Abstract
Microstructure changes in the 2618 aluminium alloy during creep-fatigue tests were studied. These tests simulate the conditions of the application of this alloy in devices for the exhaustion of hot gasses generated during fire in closed or difficultly accessible areas. Creep-fatigue tests result in high dislocation density in subgrains and narrow subgrain boundaries, in contrast to creep tests reported in our previous work where large subgrains were observed with relatively wide subgrain boundaries and relatively low dislocation density in grains. Extensive precipitation occurred with denuded (precipitate-free) zones along grain boundaries. The coherent S-phase (Al2CuMg) transformed into partially coherent needle-shaped S′ precipitates. Superior stress amplitude caused reduced lifetime and wider denuded zones. A model of the formation of denuded zones along (sub)grain boundaries was proposed.
Melting temperature of metallic nanoparticles embedded in a rigid matrix
Authors: Vollath Dieter 
Published: March 2012

Abstract
Phase transformations of freestanding nanoparticles are well analyzed. The situation is different for particles embedded in a second matrix. The special case of melting and crystallizing of nanoparticles in a rigid matrix is the topic of this study based on the energy balance, resulting in a size dependency of these phase transformations primarily on variation of the materials properties with the particle size. Therefore, an important outcome of this study is the result that thermodynamic data of bulk materials are insufficient to describe phenomena connected to nanoparticles. The differences may be significant.
Non-covalent assembly of hybrid nanostructures of gold and palladium nanoparticles with carbon nanotubes
Authors: del Río Rodrigo Segura 
Published: March 2012

Abstract
Hybrid nanostructures were prepared by mixing gold and palladium nanoparticles with multi- and single-walled carbon nanotubes. The approach to prepare these nanohybrid implies the interaction of long hydrocarbon chains chemisorbed at the nanoparticles surface and the graphitic walls of nanotubes. Transmission electron microscopy results show the efficiency of this simple method to assemble these nanostructures. The electron microscopy images show that nanoparticles are effectively absorbed on the nanotube surfaces homogeneously but without any particular order. These nanostructures have proven to be stable after a moderate ultrasonic treatment.
Adsorption of bovine serum albumin onto titanium dioxide nanotube arrays
Authors: Shi Jie , Feng Bo , Lu Xiong , Weng Jie 
Published: March 2012

Abstract
Titanium dioxide nanotube arrays on titanium were fabricated via anodic oxidation and heat treatment. The diameters of nanotubes ranged from 20 to 200 nm, and the lengths were 500 and 1000 nm. The adsorption behavior of bovine serum albumin onto the nanotube arrays was investigated. Surface characterization for samples was carried out using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Adsorbance of bovine serum albumin was detected with an ultraviolet spectrophotometer. The results showed that the nanotube arrays on titanium surfaces significantly enhanced bovine serum albumin adsorption. The nanotube arrays with larger diameter could adsorb more bovine serum albumin, but longer nanotubes showed less adsorbance than shorter nanotubes. In the present work, the nanotube arrays with 160–200 nm diameter, the largest diameter, showed the highest adsorption ability, and the maximum adsorption capacity q
m was 31.40 mg · cm−2. In addition, the adsorbance of bovine serum albumin increased with increase of initial bovine serum albumin concentrations, and a saturation value was achieved at the initial bovine serum albumin concentration of 2.0 mg · ml−1.