bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective coatings for enhanced performance in biomedical applications
Authors: Leonard R L , Hasan S A , Terekhov A Y , Thompson C , Erck R A , Dickerson J H , Johnson J A
Published: June 2012

Biomedical implants such as prosthetic hips and heart stents and instruments used in vivo all have negative performance issues. A common solution, which can also be appropriate for other devices, is to apply a diamond-like carbon thin film in order to enhance the performance of the devices. The films were produced by pulsed laser deposition and characterised by Raman spectroscopy, atomic force microscopy, ball on flat tribometry, contact angle measurements and spectrophotometry. The stability of the films was checked by soaking in simulated body fluid (SBF). The root mean square surface roughness was found to be <1 nm, and a coefficient of friction of 0·08 was produced in a lubricated environment. Contact angles ranged from 65 to 88°. The coatings produced on fused silica had high transparency and showed no delamination after 43 weeks of immersion in SBF. These films have potential to enhance the performance of biomedical implants and instruments.
MicroRNA-143 down-regulates Hexokinase 2 in colon cancer cells
Authors: Gregersen Lea H , Jacobsen Anders , Frankel Lisa B , Wen Jiayu , Krogh Anders , Lund Anders H
Published: June 2012

Background

MicroRNAs (miRNAs) are well recognized as gene regulators and have been implicated in the regulation of development as well as human diseases. miR-143 is located at a fragile site on chromosome 5 frequently deleted in cancer, and has been reported to be down-regulated in several cancers including colon cancer.

Methods

To gain insight into the role of miR-143 in colon cancer, we used a microarray-based approach in combination with seed site enrichment analysis to identify miR-143 targets.

Results

As expected, transcripts down-regulated upon miR-143 overexpression had a significant enrichment of miR-143 seed sites in their 3'UTRs. Here we report the identification of Hexokinase 2 (HK2) as a direct target of miR-143. We show that re-introduction of miR-143 in the colon cancer cell line DLD-1 results in a decreased lactate secretion.

Conclusion

We have identified and validated HK2 as a miR-143 target. Furthermore, our results indicate that miR-143 mediated down-regulation of HK2 affects glucose metabolism in colon cancer cells. We hypothesize that loss of miR-143-mediated repression of HK2 can promote glucose metabolism in cancer cells, contributing to the shift towards aerobic glycolysis observed in many tumors.
MicroRNAs and hepatitis C virus: Toward the end of miR-122 supremacy
Authors: Hoffmann Thomas Walter , Gilles Duverlie , Abderrahmane Bengrine
Published: June 2012

The most common etiologic agents causing chronic hepatitis are hepatitis C and B viruses (HCV and HBV, respectively). Chronic infection caused by HCV is considered one of the major causative agents of liver cirrhosis and hepatocellular carcinoma worldwide. In combination with the increasing rate of new HCV infections, the lack of a current vaccine and/or an effective treatment for this virus continues to be a major public health challenge. The development of new treatments requires a better understanding of the virus and its interaction with the different components of the host cell. MicroRNAs (miRNAs) are small non-coding RNAs functioning as negative regulators of gene expression and represent an interesting lead to study HCV infection and to identify new therapeutic targets. Until now, microRNA-122 (miR-122) and its implication in HCV infection have been the focus of different published studies and reviews. Here we will review recent advances in the relationship between HCV infection and miRNAs, showing that some of them emerge in publications as challengers against the supremacy of miR-122.
A benign teratoma presenting as an obstruction of the nasal cavity: a case report
Authors: Cukurova Ibrahim , Gumussoy Murat , Yaz Aytekin , Bayol Umit , Yigitbasi Orhan Gazi
Published: June 2012

Introduction

Teratoma refers to a neoplasm that recapitulates all three germ layers. Teratomas may be histologically mature and oncologically benign. Teratomas may also be histologically immature while being oncologically benign, or they may harbor malignant components and have the potential to exhibit an aggressive biological behavior. Teratomas of the head and neck are extremely rare and usually present in the neonatal period. As a general rule, pediatric teratomas of the head and neck tend to be oncologically benign, whereas adult teratomas tend to be histologically and oncologically malignant. Most of these teratomas are found in the cervical region and nasopharynx. Calcification within the mass is often evident.

Case presentation

A 27-year-old Caucasian man complaining of a nasal obstruction was admitted to our clinic in January 2006. A transnasal endoscopic examination revealed a mass arising from the nasal septum which was completely removed using an endoscopic approach. Histologically, it was determined to be a benign teratoma.

Conclusion

Herein, we present a rare case, along with a review of the related literature, in order to emphasize that a benign teratoma of the nasal septum should not be ignored.
A case of patellar fractures in monozygotic twin gymnasts
Authors: Beamish Andrew J , Roberts Gareth L , Cnudde Peter
Published: June 2012

We present a case of near identical patellar fractures in adolescent monozygotic twins who are both high-level competitive gymnasts. These patients presented 14 months apart with almost identical history and clinical findings. Both had an intense training regime involving over 30 hours per week of load-bearing exercise. Clinical and radiological examinations suggested avulsion or sleeve fracture of the inferior pole of the patella with minimal displacement. Diagnoses of patellar stress fracture with avulsion of the distal pole and symptomatic bipartite patella could not be reliably excluded. Both fractures were treated conservatively with immobilisation of the knee in extension. An excellent functional result was observed in both patients with return to full activity at 8 weeks.

This is the first published case of identical injury to the patella in monozygotic twins. A significant genetic influence on bone mineral density (BMD) has been reported and low BMD is associated with increased susceptibility to fracture. These injuries corroborate a genetic influence on susceptibility to fracture. There is a requirement for further work to investigate genetic factors influencing susceptibility to fracture.
Self-potential signals from an analog biogeobattery model
Authors: Fachin Sergio J. S. , Abreu Eduardo L. , Mendonça Carlos A. , Revil André , Novaes Guilherme C. , Vasconcelos Suzan S.
Published: June 2012

A tank experiment was conducted to check if self-potential (SP) signals can be generated when buried organic matter is wire-connected to a near-surface, oxygen-rich, sediment layer. This experiment demonstrated that once wired, there was a flux of electrons (hence an electric current) between the lower and upper layers of the sandbox with the system responding as a large-scale microbial fuel cell (a type of bioelectrochemical system). An electric current was generated by this process in the wire and the SP method was used to monitor the associated electric potential distribution at the top of the tank. The electric field was controlled by the flux of electrons through the wire, the oxidation of the organic matter, the reduction of oxygen used as a terminal electron acceptor, and the distribution of the DC resistivity in the tank. The current density through the wire was limited by the availability of oxygen and not by the oxidation of the organic matter. This laboratory experiment incorporated key elements of the biogeobattery observed in some organic-rich contaminant plumes. This analogy includes the generation of SP signals associated with a flux of electrons, the capacity of buried organic matter in sustaining anodic reactions, network resistance connecting terminal redox reactions spatially separated in space, and the existence of anodic secondary coupled reactions. A resistivity tomogram of the tank, after almost a year in operation, suggests that oxidative processes triggered by this geobattery can be imaged with this method to determine the radius of influence of the bioelectrochemical system.
Efficient 3D frequency response modeling with spectral accuracy by the rapid expansion method
Authors: Chu Chunlei , Stoffa Paul L.
Published: June 2012

Frequency responses of seismic wave propagation can be obtained either by directly solving the frequency domain wave equations or by transforming the time domain wavefields using the Fourier transform. The former approach requires solving systems of linear equations, which becomes progressively difficult to tackle for larger scale models and for higher frequency components. On the contrary, the latter approach can be efficiently implemented using explicit time integration methods in conjunction with running summations as the computation progresses. Commonly used explicit time integration methods correspond to the truncated Taylor series approximations that can cause significant errors for large time steps. The rapid expansion method (REM) uses the Chebyshev expansion and offers an optimal solution to the second-order-in-time wave equations. When applying the Fourier transform to the time domain wavefield solution computed by the REM, we can derive a frequency response modeling formula that has the same form as the original time domain REM equation but with different summation coefficients. In particular, the summation coefficients for the frequency response modeling formula corresponds to the Fourier transform of those for the time domain modeling equation. As a result, we can directly compute frequency responses from the Chebyshev expansion polynomials rather than the time domain wavefield snapshots as do other time domain frequency response modeling methods. When combined with the pseudospectral method in space, this new frequency response modeling method can produce spectrally accurate results with high efficiency.
The Provision Ground in New York: Claude McKay and the Form of Memory
Authors: Posmentier Sonya
Published: June 2012

Reading Claude McKay’s “The Tropics in New York” as a twentieth-century aesthetic equivalent of a slave provision ground, Posmentier argues that the poem asserts cultural autonomy even in the face of the dislocation it describes. In doing so, she suggests that formal lyric poetry can share the burdens and possibilities of these agricultural spaces, insofar as it takes shape in relationship to an oppressive colonial tradition while defining a black expressive form that resists its own utility within the postplantation aesthetic economy. Posmentier reads McKay’s American sonnet in the context of “Quashie to Buccra,” his earlier meditation on agricultural labor and the cultivation of poetic taste, to highlight the narrative of work omitted from the later poem. In fragmenting that narrative, “Tropics” generates an alternative temporality and spatiality of freedom.
Unsettling Ecocriticism: Rethinking Agrarianism, Place, and Citizenship
Authors: Fiskio Janet
Published: June 2012

In light of Ursula Heise’s recent critiques of the concept of a “sense of place” in ecocriticism as well as the vibrant social movement for food justice emerging in the United States, Fiskio asks whether the concept of place can be reformulated in ways that are inclusive of communities on the borders of the food system and compelling to contemporary ecocriticism. Ecocriticism has relied until now on traditional agrarian ideals that privilege long-term inhabitation of place as a basis for responsible citizenship. Through close readings of Wendell Berry’s stories and essays, Helena María Viramontes’s novel Under the Feet of Jesus, and the documentary film The Garden, Fiskio argues for an agrarianism of the margins that unsettles these fundamental assumptions, illuminating the ethical agency of migrant and transnational laborers in situations of transience, and opening a space for multiple ways of producing food, community, and place.
Preparation of Lipophilic Anionic Polymer Networks Based on Tetraphenylborates
Authors: Furukawa Yuki , Kokado Kenta , Sada Kazuki
Published: June 2012

Novel anionic and lipophilic polymer networks have been successfully synthesized by imine formation between tetraphenylborates and 1,4-phenylenediamine. The obtained polymer networks showed various morphologies depending on the dielectric constant of media used in the synthesis. Moreover, the addition of water led to polymer networks with spherical structure presumably due to suppression of imine formation.
Liquid-phase Deposition of Titanium Oxide Film on Silicon Substrate Mediated by Polydopamine
Authors: Ou Junfei , Wang Fajun , Xue Mingshan , Wang Ying , Yao Junping , Li Wen
Published: June 2012

Polydopamine (PDA) bearing surface catechol groups on a silicon wafer was used to induce the deposition of thin TiO2 films from aqueous solution. Different deposition conditions, such as the concentration and pH of precursor solution as well as the deposition temperature, were adopted. It was found that the growth rate and crystalline phase can be controlled by these deposition parameters; moreover, the crystal growth and adhesion strength to the substrate of TiO2 film can be promoted by PDA layer.
Theoretical Studies of Solvation Effects on 2-(2-Hydroxyphenyl)benzimidazole
Authors: Kuroki Ayaka , Ushiyama Hiroshi , Yamashita Koichi
Published: June 2012

Stabilization energies at enol, keto, and transition state structures of 2-(2-hydroxyphenyl)benzimidazole in several types of solvents are systematically examined by quantum chemistry calculations. The solvent effects on the stability of keto are discussed and it has been shown that the keto form on the ground state does not have a local minimum in any type of solvents.
Effects of Alkoxy Substitution on the Optical Properties of 9,10-Anthraquinone and Anthracene: 2,3,6,7-Tetrapropoxy-substituted vs. 2,6-Dipropoxy-substituted Derivatives
Authors: Ohta Akira , Hattori Kazuki , Kusumoto Yui , Kawase Takeshi , Kobayashi Takashi , Naito Hiroyoshi , Kitamura Chitoshi
Published: June 2012

2,3,6,7-Tetrapropoxy- and 2,6-dipropoxy-substituted 9,10-anthraquinone (AQ) and anthracene (ANT) derivatives were synthesized, and their optical properties in solution and in the solid state were investigated. In AQs, the tetrapropoxy derivative exhibited a red shift of absorption in comparison with the dipropoxy derivative and ANT. In contrast, in ANTs, the dipropoxy derivative exhibited a red shift of absorption and fluorescence in comparison with the tetrapropoxy derivative and ANT. The electronic effects of alkoxy substitution could be explained by TD-DFT calculations.
Biology of metabolic syndrome in a vascular patient
Authors: Vykoukal Daynene , Davies Mark G
Published: June 2012

Metabolic syndrome is highly prevalent in vascular patients and has a significant impact on the outcomes of vascular interventions. It comprises of a set of metabolically driven risk factors, including truncal obesity, dyslipidemia, elevated blood pressure and elevated fasting blood glucose. Increased insulin resistance within the context of obesity and hypertension contributes to atherogenic dyslipidemia, hyperglycemia, and prothrombotic and proinflammatory states which lead to the adverse impact of metabolic syndrome on the response to injury and on atherosclerotic disease progression. This review focuses on the complex biology of metabolic syndrome and its relevance to management of vascular patients, including outcomes and implications for the coronary, cerebrovascular and lower-extremity vascular beds.
An uncommon clinical presentation of acute limb ischemia: underscoring the role of perigenicular collaterals
Authors: Georgakarakos Efstratios , Kapoulas Konstantinos , Koukoumtzis Dimitris , Mantatzis Michalis , Lazarides Miltos K
Published: June 2012

We present a case of atypical acute limb ischemia in a non-diabetic patient, with ankle–brachial pressure index of 0.6 and rest pain localized exclusively over the gastrocnemius muscle, sparing the foot. This uncommon presentation was attributed to an impaired perigenicular collateral network. Thrombolysis restored adequate perfusion only temporarily and was followed by thromboembolectomy. The ischemia presentation in our case underscores the importance of the adequacy of the perigeniculate collateral network for the perfusion of the tibial muscles and, especially, the gastrocnemius muscle.
Preoperative risk factors for in-hospital mortality and validity of the Glasgow aneurysm score and Hardman index in patients with ruptured abdominal aortic aneurysm
Authors: Kurc Erol , Sanioglu Soner , Ozgen Ayca , Aka Serap Aykut , Yekeler Ibrahim
Published: June 2012

The aim of this study is to evaluate the validity of the Glasgow aneurysm score (GAS) and Hardman index in patients operated on because of ruptured abdominal aortic aneurysm (rAAA), and determining preoperative risk factors that affect in-hospital mortality. One hundred one patients operated on to repair a rAAA within the last 10 years were included. The GAS and Hardman index were calculated for each patient separately. The relation between in-hospital mortality and the Hardman index and GAS was analyzed by means of the receiver-operator characteristic (ROC) curve. Univariate and multivariate methods of analyses were used to determine preoperative risk factors. Average age was 69 ± 8, and in-hospital mortality rate was 51.5%. Analysis of the ROC curve showed that the Hardman index had an area under the curve (AUC) = 0.71 (95% confidence interval [CI], 0.593–0.800, P = 0.0002) for predicting in-hospital mortality. The GAS had an AUC = 0.77 (95% CI, 0.680–0.851, P < 0.0001). The results of multivariate analysis revealed the presence of the following preoperative risk factors: age more than 63 years (odds ratio [OR], 4.4; 95% CI, 1.17–16.49, P = 0.028); loss of consciousness (OR, 9.33; 95% CI, 1.94–44.86, P = 0.005); creatinine higher than 1.7 mg/dL (OR, 5.52; 95% CI, 1.92–15.85, P = 0.001); and pH lower than 7.31 (OR, 3.77; 95% CI, 1.18–11.99, P = 0.024). In conclusion, the Hardman index and GAS have a significant correlation with in-hospital mortality rates. Nevertheless, a high score does not necessarily correspond with a definite mortality. This is why scoring systems could not be considered as the sole criterion for choosing patients for this study. Clinical experience was still the leading factor in deciding against or in favor of surgery.
Size matters! A reliable endovascular method to avoid infolding and endoleaks when reconstructing aortic bifurcations using stent grafts
Authors: Matteo Jerry , Cunningham James
Published: June 2012

Conventional revascularization of the lower extremities secondary to aortoiliac atherosclerotic vascular disease (ASVD) involves major intra-abdominal surgery with aortobifemoral bypass grafting. Complication rates are as high as 10% and perioperative mortality can be as high as 5%; therefore, careful patient selection is paramount. Endovascular aortobifemoral bypass repair with aortic bifurcation reconstruction is an emerging option in patients deemed unsuitable for conventional surgical management. Emerging techniques such as snorkel/chimney method are expanding the number of patients who can undergo endovascular repair of abdominal aortic aneurysms and/or revascularization of the lower extremities. However, until now, objective criteria for stent size selection used in these hybrid techniques have not been described.
Duplex ultrasound interpretation criteria for inferior mesenteric arteries
Authors: AbuRahma Ali F , Scott Dean L
Published: June 2012

There is no specific duplex ultrasound (DUS) criteria for the diagnosis of inferior mesenteric artery (IMA) stenosis. This study will define the optimal duplex velocity values with the best overall accuracy (OA) in detecting ≥50% stenosis of the IMAs. Eighty-five IMAs with both DUS and mesenteric arteriography were analyzed. Eighty-five IMAs were examined: 45 were normal, 12 with <50% stenosis, eight with ≥50–69% stenosis and 15 with ≥70% stenosis (including occlusion) based on angiography. The mean peak systolic velocities (PSVs) for a normal IMA, <50% and ≥50% stenosis was 105, 215 and 392 cm/second, respectively ( P < 0.0001). The most accurate PSV in detecting ≥50% stenosis was ≥250 cm/second with a sensitivity of 90%, a specificity of 96% and an OA of 95%. The most accurate end-diastolic velocity (EDV) in detecting ≥50% stenosis was ≥80% or ≥90 cm/second, with an OA of 86%, a sensitivity of 60% and a specificity of 100%. The most accurate ratio in detecting ≥50% stenosis was ≥4 or ≥4.5 with an OA of 93%.Receiver operator curves analysis showed that the PSV was not better than EDV and PSV ratio in detecting ≥50% stenosis ( P = 0.1661 and 0.4568, respectively). In conclusion, specific IMA PSVs, EDVs and IMA/aortic systolic ratios can be used in detecting significant IMA stenosis with reasonable accuracy.
Pharmacological Evaluation of Fruits of Terminalia belerica Roxb. for Antiulcer Activity
Authors: Jawanjal Hitesh , Rajput Mithun S. , Agrawal Purti , Dange Vikramsingh
Published: June 2012

The antiulcer activity of 70% methanolic extract of fruits of Terminalia belerica Roxb. (Combretaceae) was evaluated using ethanol induced, aspirin induced, cold stress restraint and pylorus ligated ulcer in rats. The methanolic extract (100, 250, 500, 1000 mg/kg, p.o.) significantly suppressed the peptic ulcer induced by ethanol. Methanolic extract at a dose of 500 mg/kg showed, promising antiulcer activity hence, this dose was selected for further evaluation of antiulcer studies. The methanolic extract (500 mg/kg) showed significant (p<0.05) reduction in gastric volume, free acidity, total acidity, ulcer index, protein and pepsin content and increase in mucus content in pylorus ligated rats as compared to control. Treatment with Terminalia belerica methanolic extract further provided significant antiulcer protection against aspirin induced ulcers but not in cold stress restraint model. These results suggested that the 70% methanolic extract of Terminalia belerica increased resistance to necrotizing agents, providing a direct protective effect on the gastric mucosa and exhibited antiulcer effect.
Recent Trends in Earnings Volatility: Evidence from Survey and Administrative Data
Authors: Celik Sule , Juhn Chinhui , McCue Kristin , Thompson Jesse
Published: June 2012

Recent papers find that earnings volatility is again on the rise (Dynan et al. 2008, and Shin and Solon 2011). Using household survey data—the matched Current Population Surveys and Survey of Income and Program Participation—and the newly available Longitudinal Employment and Household Dynamics administrative dataset, we find that earnings volatility was remarkably stable in the 1990s and through the mid 2000s. This evidence is in contrast to that from the Panel Study of Income Dynamics (PSID) which registers a sharp increase in the early 2000s. We investigate whether adjusting measures based on our sources to more closely match the characteristics of the PSID can reconcile this divergence in trends, but do not find a clear explanation for the divergence. We also find little evidence of a rise over this period in the components of volatility: volatility among job leavers, volatility among job stayers, and the fraction of workers who are job leavers.
Asset Risk Management of Participating Contracts
Authors: Bernard Carole , Le Courtois Olivier
Published: June 2012

In this paper we study the asset-liability management of an insurance company selling “participating contracts”. Participating contracts are typical insurance policies sold in Europe, in Japan or in North America. The payoff of a participating policy is linked to the portfolio and the surplus of the insurance company. We examine the impact of the choice of the assets' investment strategy on the company value, its solvency and how well the company may meet the commitments associated with its liabilities. Our goal is to exhibit an investment strategy matching as much as possible assets and liabilities at their market value and complying with existing regulation constraints. It is then shown that a dynamic CPPI strategy can significantly reduce the default probability of the company, and increase the policyholders contracts' market values. Consequently our study also shows that the valuation of participating policies and the determination of fair contracts should not be done neglecting the impact of the choice of the assets' allocation strategy.
Editor's Note
Authors: Young Dennis R.
Published: June 2012

This first issue of 2012 comes at a time when the economy of Europe is still in turmoil and the presidential election contest is heating up in the United States. Both venues raise critical policy issues and concerns in which nonprofit organizations play a central part.
The kinesin superfamily protein KIF17: one protein with many functions
Authors: Wong-Riley Margaret T.T. , Besharse Joseph C.
Published: June 2012

Kinesins are ATP-dependent molecular motors that carry cargos along microtubules, generally in an anterograde direction. They are classified into 14 distinct families with varying structural and functional characteristics. KIF17 is a member of the kinesin-2 family that is plus end-directed. It is a homodimer with a pair of head motor domains that bind microtubules, a coiled-coil stalk, and a tail domain that binds cargos. In neurons, KIF17 transports N-methyl-D-aspartate receptor NR2B subunit, kainate receptor GluR5, and potassium Kv4.2 channels from cell bodies exclusively to dendrites. These cargos are necessary for synaptic transmission, learning, memory and other functions. KIF17’s interaction with nuclear RNS export factor 2 (NXF2) enables the transport of mRNA bidirectionally in dendrites. KIF17 or its homolog osmotic avoidance abnormal protein 3 (OSM-3) also mediates intraflagellar transport of cargos to the distal tips of flagella or cilia, thereby aiding in ciliogenesis. In many invertebrate and vertebrate sensory cells, KIF17 delivers cargos that contribute to chemosensory perception and signal transduction. In vertebrate photoreceptors, KIF17 is necessary for outer segment development and disc morphogenesis. In the testis, KIF17 (KIF17b) mediates microtubule-independent delivery of an activator of cAMP-responsive element modulator (ACT) from the nucleus to the cytoplasm and microtubule-dependent transport of Spatial-ε, both are presumably involved in spermatogenesis. KIF17 is also implicated in epithelial polarity and morphogenesis, placental transport and development, and the development of specific brain regions. The transcriptional regulation of Kif17 has recently been found to be mediated by nuclear respiratory factor 1 (NRF-1), which also regulates NR2B as well as energy metabolism in neurons. Dysfunctions of KIF17 are linked to a number of pathologies.
Peptide-nucleic acid nanostructures for transfection
Authors: Bechinger Burkhard
Published: June 2012

To use nucleic acids in biomedical research and medical applications, these highly hydrophilic macromolecules have to be transported through the organism, targeted to specific cell surfaces, and have to cross cellular barriers. To this end, nanosized transfection complexes have been designed and several of them have been successfully tested. Here, the different steps of the transfection process and the particular optimization protocols are reviewed, including the physicochemical properties of such vectors (size, charge, composition), protection in serum, cellular uptake, endosomal escape, and intracellular targeting. The transfection process has been subdivided into separate steps and here special emphasis is given to peptides that have been designed to optimize these steps individually. Finally, complex devices encompassing a multitude of beneficial functionalities for transfection have been developed.
Extending Service Area of IEEE 802.11 Ad Hoc Networks
Authors: Choi Woo-Yong
Published: June 2012

According to the current IEEE 802.11 wireless LAN standards, IEEE 802.11 ad hoc networks have the limitation that all STAs (Stations) are in the one-hop transmission range of each other. In this paper, to alleviate the limitation of IEEE 802.11 ad hoc networks we propose the efficient method for selecting the most appropriate pseudo AP (Access Point) from among the set of ad hoc STAs and extending the service area of IEEE 802.11 ad hoc networks by the pseudo AP’s relaying the internal traffic of IEEE 802.11 ad hoc networks. Numerical examples show that the proposed method significantly extends the service area of IEEE 802.11 ad hoc networks.
Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 2. Action in soda pulping conditions on softwood and phenolic β-O-4 lignin models
Authors: Cazeils Emmanuel , Megiatto Jackson D. , Gardrat Christian , Pichavant Frédérique , Grelier Stéphane , Castellan Alain
Published: June 2012

Two hydrophobic and one hydrophilic anthraquinone (AQ) polystyrene catalysts were tested under soda pulping conditions on thermomechanical fibers, and the results were evaluated based on commercial AQ. Hydrophobic and hydrophilic polymers had efficiency gains of 23%–28% and 57%, respectively, compared to AQ (100% efficiency). Hydrosolubility of AQ polymers played a major role in delignification efficiency, a property that allows a better contact with lignocellulosic fibers. Hydrophobic copolymers were stable under pulping conditions and preserved their catalytic effect entirely by contrast to the hydrophilic AQ, as demonstrated by recovery yields after pulping and catalytic action of the recovered copolymers. Studies on lignin models confirmed that the hydrophilic AQ polystyrene is a better catalyst under soda pulping conditions than the hydrophobic ones. It was demonstrated that AQ polystyrene polymers react with lignin models by electron transfer mechanisms.
Association of high-sensitivity C-reactive protein serum levels in early pregnancy with the severity of preeclampsia and fetal birth weight
Authors: Behboudi-Gandevani Samira , Moghadam Narges Alian , Mogadam-banaem Lida , Mohamadi Bita , Asghari Mohamad
Published: June 2012

Objective: The aim of this study was to investigate the association between high-sensitivity C-reactive protein (hs-CRP) serum levels in early pregnancy with the severity of preeclampsia (PE) and birth weight.

Study design: A prospective cohort study was conducted in Noor City (in the north of Iran) from February 2008 to March 2009. The maternal serum hs-CRP levels were measured in 778 healthy pregnant women between 14 and 20 weeks of gestation. They were followed up to delivery. The women were divided into three groups according to ACOG criteria: mild and severe PE and normal group.

Results: In total, 63 (8.1%) of the subjects developed PE: 30 (3.9%) mild and 33 (4.2%) severe PE. Mean±SD hs-CRP levels in mild (7.2±2.2 mg/L) and severe (9.4±3.9 mg/L) PE were significantly higher than the normal group (2.5±2.7 mg/L). Mean±SD birth weights in severe (3100±590 g) and mild (3150±742 g) PE were significantly lower than uncomplicated pregnancies (3340±590 g). Multiple and linear logistic regression analysis showed that there were significant relationships between hs-CRP levels in mild (odds ratio, 1.66; 95% confidence interval, 1.43–1.93) and severe PE (odds ratio, 2.35, 95% confidence interval, 1.90–2.92) and with birth weight (P<0.001). The receiver operator characteristic curve showed that hs-CRP >4.5 and >5 mg/dL could predict mild and severe PE, respectively. At this level, sensitivity and specificity for mild PE were 100% and 80.7%, and for severe PE were 93.9% and 75.7%, respectively.

Conclusion: hs-CRP can be useful in identifying pregnant women at risk for PE and low-birth weight infants.
Nanowire-based plasmonic waveguides and devices for integrated nanophotonic circuits
Authors: Wei Hong , Xu Hongxing
Published: June 2012

The fast development of plasmonics have greatly advanced our understanding to the abundant phenomena related to surface plamon polaritons (SPPs) and improved our ability to manipulate light at the nanometer scale. With tightly confined local field, SPPs can be transmitted in waveguides of subwavelength dimensions. Nanophotonic circuits built with plasmonic elements can be scaled down to dimensions compatible with semiconductor-based nanoelectronic circuits, which provides a potential solution for the next-generation information technology. Different structures have been explored as plasmonic waveguides for potential integration applications. This review is focused on metallic nanowire waveguides and functional components in nanowire networks. We reviewed recent progress in research about plasmon generation, emission direction and polarization, group velocity, loss and propagation length, and the near-field distribution revealed by quantum dot fluorescence imaging. Electrical generation and detection of SPPs moves towards the building of plasmonic circuits, where bulky external light sources and detectors may be omitted. The coupling between metal nanowires and emitters is important for tailoring light-matter interactions, and for various potential applications. In multi-nanowire structures, plasmon signal control and processing are introduced. The working principles of these nanowire-based devices, which are based on the control to the near field distributions, will become the design rule for nanophotonic circuits with higher complexity for optical signal processing. The recent developments in hybrid photonic-plasmonic waveguides and devices are promising for making devices with unprecedented performance.
Nanofabricated plasmonic nano-bio hybrid structures in biomedical detection
Authors: Zheng Wenwei , Chiamori Heather C. , Liu Gang Logan , Lin Liwei , Chen Fanqing Frank
Published: June 2012

Our study of biological systems increasingly depends on our ability to dynamically and quantitatively measure the molecular processes with high sensitivity, speed, flexibility, multiplexity, throughput, and reproducibility, usually within the context of a complex biological and chemical mixture of tiny amount. To address these major challenges, plasmon-resonant nanostructure biomolecule hybrids (nano-bio hybrids), so-called plasmonic nanobiosensors, are being developed and viewed as one key breakthrough area for real-time and parallelized biomedical analysis with high sensitivity and selectivity. Hereby, we present a solution of integrated plasmonic system by synergizing three core techniques: (i) nanoplasmonics that manipulates electromagnetic radiation (light) at dielectric-metal interfaces by tuning properties of nanomaterials, (ii) nanofabrication and controlled synthesis of nanomaterials containing noble metals (e.g., Au, Ag, Pt, and Cu), and (iii) bioconjugates techniques that modify surface of nanomaterials with various bioprobes (e.g., antibodies, enzymes, aptamers, and molecular imprint polymers). Applications of these plasmonic nano-bio hybrid structures are also discussed.
f-Element-metal bond chemistry
Authors: Patel Dipti , Liddle Stephen T.
Published: June 2012

Compared to the overwhelming prevalence of f-element-carbon, -nitrogen, -oxygen or -halide ligand linkages, the use of metal-based fragments as ligands is underdeveloped. This contrasts directly to the extensively developed fields of d- and p-block metal-metal complexes, which are still burgeoning. This review outlines the development of compounds that possess polarised covalent f-element-metal bonds. For this review, the f-element is defined as (i) a group 3 metal; (ii) a lanthanide metal; (iii) the actinide metals thorium or uranium. The metal is defined as: (i) a d-block transition metal; (ii) a group 13 metal (aluminium or gallium); (iii) a group 14 metal (silicon, germanium or tin); (iv) a group 15 metal (antimony or bismuth) metal. Although silicon, germanium and antimony are traditionally classified as metalloids, they are included for completeness. We focus on complexes that have been structurally authenticated by single crystal X-ray diffraction, and we highlight novel aspects of their syntheses, properties and reactivities.
New Surface Samplers for Use in Forensic Sampling after a Chemical Incident
Authors: Ehntholt Daniel J. , Beltis Kevin J. , Jakubowski Michael J. , Martin John F. , McComish Madeline F.
Published: June 2012

After an event involving the deliberate release of toxic chemicals, there is a need to collect samples at the affected site for preservation, recovery, and analysis of the chemical species of interest. These would likely include the active or toxic species as well as chemicals that could serve as chemical attribution signatures that would be important in assigning responsibility for the release. In this preliminary study, a standard gauze pad surface sampling material and technique was compared with the use of silicone rubber samplers placed on glass and coated steel solid surfaces. A range of commercially available silicone rubbers was examined for possible use and one was selected for more extensive evaluation due to its relative ease of handling and minimal interferences with the analytical process. The experiments were conducted with organic chemical species that covered a range of volatilities; two contaminant challenge concentrations were used. The silicone rubber samplers, as applied, were found to consistently collect higher quantities of organic chemicals from the solid surfaces than did the gauze pads. Results of these initial experiments are discussed and ongoing efforts are briefly described.
Evaluation of Chlorella Minutissima Oil for Biodiesel Production
Authors: Kaul Savita , Jain Rahul , Konathala Sivakumar , Bangwal Dinesh , Atray Neeraj , Kumar Basant
Published: June 2012

Present work is an attempt to focus on screening of microalgae chlorella minutissima, extraction of oil, and conversion of oil into biodiesel. The experimental results are supported by scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDX), high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS) analytical techniques. The SEM/EDX results indicate microalgae contain several elements that are required for lipid metabolism, e.g., calcium, magnesium, iron, potassium, and nitrogen. HPLC analysis of hexane extracted oil shows the presence of 74.27 % of free fatty acids, 10.65 % of fatty acid esters, and 13.74 % triglycerides, besides unidentified component 1.34 %. These results are in close agreement with the high acid value of the oil. The presence of fatty acid esters in the oil were also confirmed by GC-MS analysis. Under optimized conditions, of acid catalyzed transesterification >97 % conversion of microalgae oil into FAME is observed. The studies indicate that lower reaction time is favorable for conversion to FAMEs. However, for the purpose of biodiesel feedstock, any increase in the lipid content of the algae will improve the efficiency of the process.
Optimum CNT Concentration and Bath Temperature for Maximum Heat Transfer Rate during Quenching in CNT Nanofluids
Authors: Babu K. , Prasanna Kumar T. S.
Published: June 2012

This paper utilizes the experimental and numerical results obtained during quenching of stainless steel (SS) probes in carbon nanotube (CNT) nanofluids to arrive at an optimum CNT concentration and bath temperature for maximum quenching heat transfer rate. The individual effect of CNT concentration and bath temperature on the quenching heat transfer rate has recently been published by the authors. The objective of this work is to study the combined effect of CNT concentration and bath temperature on the heat transfer rate during quenching. For this purpose, CNT nanofluids were prepared by suspending chemically treated CNTs in de-ionized (DI) water without any surfactant at 0.50 and 0.75 wt. % of CNTs. Cylindrical quench probes made of SS 304L with a diameter of 20 mm and an aspect ratio of 2.5 were quenched in the CNT nanofluids by maintaining at 30, 40, and 50°C using an external water bath. The recorded time-temperature data during quenching were used as input and the heat flux and temperature at the quenched surface were estimated based on the inverse heat conduction (IHC) method. The computed boiling curves during quenching were used in conjunction with the boiling curves published in literature to arrive at an optimum CNT concentration and bath temperature for maximum heat transfer rates. The computational results showed that the peak heat flux during quenching of SS probes in CNT nanofluids increased when the CNT nanofluid was maintained at 40 than at 30°C and it started decreasing with further increase in the bath temperature irrespective of the CNT concentration. The enhanced heat transfer performance of CNT nanofluid at a slightly higher temperature during quenching is attributed to the enhanced Brownian motion of CNTs in nanofluid.
A longer interval without GH replacement and female gender are associated with lower bone mineral density in adults with childhood-onset GH deficiency: a KIMS database analysis
Authors: Tritos Nicholas A , Hamrahian Amir H , King Donna , Greenspan Susan L , Cook David M , Jönsson Peter J , Wajnrajch Michael P , Koltowska-Häggstrom Maria , Biller Beverly M K
Published: June 2012

Objective

Childhood-onset GH deficiency (COGHD) is associated with low bone mineral density (BMD). Adults with persistent COGHD may be at risk for insufficient bone accrual or bone loss during adulthood. The purpose of this study was to identify BMD predictors and to characterize the effects of GH replacement on BMD in COGHD adults with persistent GHD.

Design

Retrospective analysis of the KIMS database.

Methods

Variables predicting standardized BMD (sBMD) were identified. The effect of GH replacement (3 years) on BMD was examined.

Results

Three hundred and fourteen COGHD adults (148 women, 166 men; 62 non-naïve, 178 semi-naïve, and 74 true naïve, depending on length and timing of previous GH replacement), who had BMD measured in lumbar spine (LS) and femoral neck (FN) at study entry.

In semi-naïve subjects, a longer gap in GH replacement between childhood and adulthood was predictive of lower sBMD in the FN (r=−0.18, P=0.038). TSH deficiency predicted lower sBMD in the LS (r=−0.16, P=0.052). In true naïve patients, a longer gap between onset of pituitary disease and study entry (r=−0.35, P=0.012), and female gender (r=−0.27, P=0.043) independently predicted lower sBMD in the FN. There were no differences in BMD increases between non-naïve, semi-naïve, and true naïve subjects on GH replacement.

Conclusions

In semi-naïve subjects a longer interval off GH replacement was associated with lower sBMD in the FN. Among true naïve patients, a longer gap between the onset of pituitary disease and GH replacement, and female gender predicted lower sBMD in the FN.
Trends of Outpatient Prescription Drug Utilization in US Children, 2002–2010
Authors: Chai Grace , Governale Laura , McMahon Ann W. , Trinidad James Phillip , Staffa Judy , Murphy Dianne
Published: June 2012

OBJECTIVE:

To describe trends in outpatient prescription drug utilization in US children and the changes in major areas of pediatric therapeutic use for the years 2002 through 2010.

METHODS:

Large prescription databases (the IMS Vector One: National and Total Patient Tracker) were used to examine national drug utilization patterns for the US pediatric population (ages 0–17 years) from 2002 through 2010.

RESULTS:

In 2010, a total of 263.6 million prescriptions were dispensed to the US pediatric population, 7% lower than in 2002, while prescriptions dispensed to the adult population increased 22% during the same time. Analysis of pediatric drug utilization trends for the top 12 therapeutic areas in 2010 compared with 2002 showed decreases in systemic antibiotics (–14%), allergies (–61%), pain (–14%), depression (–5%), and cough/cold without expectorant (–42%) prescriptions, whereas asthma (14%), attention-deficit/hyperactivity disorder (46%), and contraceptive (93%) prescriptions increased. In 2010, amoxicillin was the most frequently dispensed prescription in infants (aged 0–23 months) and children (aged 2–11 years). Methylphenidate was the top prescription dispensed to adolescents (aged 12–17 years). Off-label use was identified, particularly for lansoprazole; ∼358 000 prescriptions were dispensed in 2010 for infants <1 year old.

CONCLUSIONS:

Changes in the patterns of pediatric drug utilization were observed from 2002 to 2010. Changes include a decrease in antibiotic use and an increase in attention-deficit/hyperactivity disorder medication use during the examined time. This article provides an overview of pediatric outpatient drug utilization, which could set the stage for further in-depth analyses.
Frequency of Alternative Immunization Schedule Use in a Metropolitan Area
Authors: Robison Steve G. , Groom Holly , Young Collette
Published: June 2012

OBJECTIVES:

Recent studies have described an increase in parental hesitancy regarding vaccines as well as increases in parental adoption of vaccine schedules that delay or limit receipt of recommended vaccines. This study quantifies potential prevalence and trends in alternative schedule compliance by measuring consistent shot-limiting in a metropolitan area of Oregon.

METHODS:

Retrospective cohort analysis using the Oregon ALERT Immunization Information System to track children born between 2003 and 2009 in the Portland metropolitan area. Joinpoint regression was used to analyze prevalence trends in consistent shot-limiting during that time period. The 2007–2009 Haemophilus influenzae type b vaccine shortage and increased availability of combination vaccines were also examined for their effects on shot-limiting rates.

RESULTS:

A total of 4502 of 97 711 (4.6%) children met the definition of consistent shot-limiters. The proportion of consistent shot-limiters in the population increased from 2.5% to 9.5% between 2006 and 2009. Compared with those with no or episodic limiting, consistent shot-limiters by 9 months of age had fewer injections (6.4 vs 10.4) but more visits when immunizations were administered (4.2 vs 3.3). However, only a small minority of shot-limiters closely adhered to published alternative schedules.

CONCLUSIONS:

The percentage of children consistently receiving 2 or fewer vaccine injections per visit between birth and age 9 months increased threefold within a 2-year period, suggesting an increase in acceptance of non–Advisory Committee on Immunization Practices vaccine schedules in this geographic area.
Preferred pH of silver catfish Rhamdia quelen acclimated to different pH levels
Authors: Riffel Ana Paula Konzen , Jardim Sinara , Pires Marcela Ciprandi , Bertagnolli Bruna , Corrêa Bruna Renata Silva , Ré Francine Cenzi de , Zambra Francis Maria Bao , Lubini Greice , Garcia Luciano Oliveira , Baldisserotto Bernardo
Published: June 2012

The aim of this study was to investigate the preferred pH in silver catfish Rhamdia quelen acclimated to different pH. Fish were acclimated for one week at pH 4.2±0.1, 5.2±0.1, 6.3±0.1, 7.2±0.1, 8.0±0.1, and 9.0±0.1 and after this period, transferred to a polyethylene tube with a pH gradient from 3.5 to 10.0. The position of the fish in the pH gradient was observed 1, 6 and 12 hours after transference. Results indicated that acclimation to different pH did not change pH preference of silver catfish (pH 7.0-7.6), occurring only a transitory variation around 6 hours after transference. This pH preference coincides with the best pH indicated in the literature for growth of this species.