bluuebunny/crossref_metadata_2025 huggingface dataset:
What Symptom Improvement Can Be Expected After Operation for Primary Hyperparathyroidism?
Authors: Caron Nadine R. , Pasieka Janice L.
Published: March 2009

Background

The only cure for primary hyperparathyroidism (pHPT) is operative resection of the parathyroid gland(s) responsible for the disease. The 1990 National Institute of Health’s (NIH) consensus development conference on asymptomatic pHPT and its subsequent workshop in 2001 established which clinical criteria warranted parathyroidectomy (PTx) versus observation. While there is no debate that these NIH criteria capture a group of patients likely to benefit from PTx, there is concern that these guidelines miss a significant percentage of pHPT patients who actually are symptomatic. Unfortunately, these additional symptoms are often subtle, nonspecific, not traditionally measured, frequently not assessed or considered in this patient population, and are usually attributed to other diagnoses or simply advanced age.

Methods

An evidence‐based literature review was performed assessing symptoms and clinical conditions associated with bone, neuropsychiatry, cognition, quality of life, and the neuromuscular system. The level of evidence and grade of recommendations were assigned to key studies to help determine recommendations regarding indications and potential benefits of parathyroidectomy (PTx).

Results

Symptoms ranging from decreased bone mineral density, increased fracture risk, neuropsychiatric symptoms and cognitive changes, lower quality of life, and neuromuscular symptoms were found to be associated with pHPT. The effects of PTx on these symptoms was addressed in a variety of studies that varied in quality.

Conclusion

Although there are few Level I randomized clinical trials addressing the benefit of PTx in patients with pHPT, there are supportive data to suggest that most patients with pHPT would benefit from operative cure.
Monitoring Charge Exchange in P3HT-Nanotube Composites Using Optical and Electrical Characterisation
Authors: Alexandrou Ioannis , Lioudakis Emmanouil , Delaportas Dimitrios , Zhao C. Z. , Othonos Andreas
Published: March 2009

Charge exchange at the bulk heterojunctions of composites made by mixing single wall nanotubes (SWNTs) and polymers show potential for use in optoelectronic devices such as solar cells and optical sensors. The density/total area of these heterojunctions is expected to increase with increasing SWNT concentration but the efficiency of solar cell peaks at low SWNT concentrations. Most researchers use current–voltage measurements to determine the evolution of the SWNT percolation network and optical absorption measurements to monitor the spectral response of the composites. However, these methods do not provide a detailed account of carrier transport at the concentrations of interest; i.e., near or below the percolation threshold. In this article, we show that capacitance–voltage (C–V) response of (metal)-(oxide)-(semiconducting composite) devices can be used to fill this gap in studying bulk heterojunctions. In an approach where we combine optical absorption methods withC–V measurements we can acquire a unified optoelectronic response from P3HT-SWNT composites. This methodology can become an important tool for optoelectronic device optimization.
Sol–Gel and Thermally Evaporated Nanostructured Thin ZnO Films for Photocatalytic Degradation of Trichlorophenol
Authors: Abdel Aal A. , Mahmoud Sawsan A. , Aboul-Gheit Ahmed K.
Published: March 2009

In the present work, thermal evaporation and sol–gel coating techniques were applied to fabricate nanostructured thin ZnO films. The phase structure and surface morphology of the obtained films were investigated by X-ray diffractometer (XRD) and scanning electron microscope (SEM), respectively. The topography and 2D profile of the thin ZnO films prepared by both techniques were studied by optical profiler. The results revealed that the thermally evaporated thin film has a comparatively smoother surface of hexagonal wurtzite structure with grain size 12 nm and 51 m2/g. On the other hand, sol–gel films exhibited rough surface with a strong preferred orientation of 25 nm grain size and 27 m2/g surface area. Following deposition process, the obtained films were applied for the photodegradation of 2,4,6-trichlorophenol (TCP) in water in presence of UV irradiation. The concentrations of TCP and its intermediates produced in the solution during the photodegradation were determined by high performance liquid chromatography (HPLC) at defined irradiation times. Complete decay of TCP and its intermediates was observed after 60 min when the thermal evaporated photocatalyst was applied. However, by operating sol–gel catalyst, the concentration of intermediates initially increased and then remained constant with irradiation time. Although the degradation of TCP followed first-order kinetic for both catalysts, higher photocatalytic activity was exhibited by the thermally evaporated ZnO thin film in comparison with sol–gel one.
Erratum to: “Multiple critical points of perturbed symmetric strongly indefinite functionals” [http://dx.doi.org/10.1016/j.anihpc.2008.06.002]
Authors: Bonheure Denis , Ramos Miguel
Published: March 2009

We correct the statement and the proof of Proposition 9 in [D. Bonheure, M. Ramos, Multiple critical points of perturbed symmetric strongly indefinite functionals].
Traveling waves in a one-dimensional heterogeneous medium
Authors: Nolen James , Ryzhik Lenya
Published: March 2009

We consider solutions of a scalar reaction–diffusion equation of the ignition type with a random, stationary and ergodic reaction rate. We show that solutions of the Cauchy problem spread with a deterministic rate in the long time limit. We also establish existence of generalized random traveling waves and of transition fronts in general heterogeneous media.
How can antipsychotics cause diabetes mellitus? Insights based on receptor-binding profiles, humoral factors and transporter proteins
Authors: Starrenburg F.C.J. , Bogers J.P.A.M.
Published: March 2009

The prevalence of Diabetes Mellitus (DM) is becoming a serious public health problem. The use of atypical antipsychotics has been associated with disruption of the glucose metabolism and therefore with causing DM. The underlying mechanisms are unknown, but knowledge of the differences between the pharmacological features of various antipsychotics combined with their diabetogenic profile might help us to understand those mechanisms. This article describes how the binding of various essential receptors or transporters in essential body tissues, adipose tissue, pancreatic tissue and liver and skeletal muscle tissue can cause disruption of the glucose metabolism. With such knowledge in mind one can try to explain the differences between the diabetogenic propensities of various antipsychotics. It is well known that clozapine and olanzapine cause weight gain and DM, whereas aripiprazole and ziprasidone have much less disruptive clinical profiles. The most significant risk factor for adiposity seems to be strong blocking of histaminergic receptors. An agonistic activity on serotonergic-1a receptors, with a very low affinity for muscarinergic-3 receptors, might protect against the development of DM. More data will become available which may help to solve the puzzle.
Interleukin‐1ß is a positive regulator of TIARP/STAMP2 gene and protein expression in adipocytes in vitro
Authors: Kralisch Susan , Sommer Grit , Weise Sebastian , Lipfert Jana , Lossner Ulrike , Kamprad Manja , Schröck Kathleen , Bluher Matthias , Stumvoll Michael , Fasshauer Mathias
Published: March 2009

The impact of interleukin (IL)‐1ß on tumor necrosis factor α‐induced adipose‐related protein (TIARP)/six‐transmembrane protein of prostate 2 (STAMP2) was determined in adipocytes. TIARP/STAMP2 mRNA synthesis was significantly stimulated by IL‐1ß in a dose‐ and time‐dependent fashion in 3T3‐L1 adipocytes. Signaling studies suggested that janus kinase 2, nuclear factor κB, and p44/42 mitogen‐activated protein kinase are involved in IL‐1ß‐induced TIARP/STAMP2 mRNA expression. Furthermore, IL‐1ß, TNFα, and IL‐6 showed synergistic stimulatory effects on TIARP/STAMP2 gene expression. Moreover, both TIARP/STAMP2 mRNA synthesis and protein expression were induced by IL‐1ß in fully differentiated human mesenchymal stem cell‐derived adipocytes (hMSC‐Ad). Taken together, TIARP/STAMP2 is highly upregulated in 3T3‐L1 cells and hMSC‐Ad by IL‐1ß and might, therefore, modulate proinflammatory and insulin resistance‐inducing effects of IL‐1ß.
NMDA receptors interact with flotillin‐1 and ‐2, lipid raft‐associated proteins
Authors: Swanwick Catherine Croft , Shapiro Marietta E. , Yi Zhaohong , Chang Kai , Wenthold Robert J.
Published: March 2009

MINT‐7013162: NR1 (uniprotkb:P35439) physically interacts (MI:0218) with NR2A (uniprotkb:Q00959) by anti bait coimmunoprecipitation (MI:0006)
Minimally invasive video‐assisted thyroidectomy: A retrospective study over two years of experience
Authors: Snissarenko Eugene P. , Kim Grace H. , Simental Alfred A. , Zwart Jon E. , Ransbarger Darron M. , Kim Paul D.
Published: March 2009

Objective

The minimally invasive video‐assisted thyroidectomy technique has slowly gained acceptance. Previous studies have reported advantages of better cosmetic results and faster postoperative recovery. We report preliminary results from our single assistant technique over the initial two years of inception at an academic training center.

Methods

This study consists of a retrospective chart review of 172 cases between May 2005 and September 2007. All cases started as video‐assisted thyroidectomy were included. Demographic, pre‐ and postoperative clinical data, imaging results, and hospital stay were collected.

Results

Acceptable data were available for 24 male and 148 female patients who underwent the video‐assisted procedure. Five cases were converted to the conventional thyroidectomy. Of the 172 cases, 60 total thyroidectomies and 112 hemithyroidectomies were performed, with 37 cases of malignancy. The average hospitalization was 1.43 days with mean incision length was 3.51 cm, mean surgical time of 91.37 minutes, and mean blood loss of 31 cc. Transient voice problems were noted in 10 patients.

Conclusion

We found statistically improved operative times, hospital stay, and blood loss the first 2 years with a low rate of temporary complications. It appears that minimally invasive video‐assisted thyroidectomy is a safe and feasible option to standard thyroidectomy in selected patients.
A double‐blind randomized controlled trial of management of recurrent nosebleeds in children
Authors: Calder Nicholas , Kang Swee , Fraser Lyndsay , Kunanandam Tash , Montgomery Jennifer , Kubba Haytham
Published: March 2009

Background

To establish whether a treatment regimen of silver nitrate cautery and 4 weeks of antiseptic nasal cream is superior to antiseptic cream treatment alone in the management of pediatric epistaxis.

Study Design

Double‐blind randomized controlled trial.

Subjects and Methods

Children with epistaxis and visible anterior septal vessels were invited to participate. Patients were randomized to receive treatment or control. Treatment patients received silver nitrate cautery, followed by antiseptic cream for 4 weeks. Control patients received sham cautery followed by antiseptic cream for 4 weeks.

Results

A total of 109 patients were randomized and results were available for 93 (85%). Of those receiving cautery, 21 (45.7%) of 46 had no bleeding in the 4 weeks before follow‐up. Of those receiving only antiseptic cream 14 (29.8%) of 47 had no bleeding. (χ2 = 2.49; P = 0.114). More children in the active treatment group had an improvement in their symptoms compared with controls (42 of 46; 91.3%) in the treatment group vs 33 of 47 (70.2%) controls (χ2 = 6.626; P = 0.01; relative risk reduction = 71 percent, number needed to treat = 4.7).

Conclusion

When using subjective improvement in symptoms as the outcome measure, silver nitrate cautery with antiseptic cream twice daily for 4 weeks appears to give a small but statistically significant benefit when compared to antiseptic cream alone.
The comparison of histopathological characteristics of polyps in asthmatic and nonasthmatic patients
Authors: Ardehali Mojtaba Mohammadi , Amali Amin , Bakhshaee Mehdi , Madani Ziaodin , Amiri Mandana
Published: March 2009

Introduction

Considering the different clinical aspects of polyps in asthmatic and nonasthmatic patients, we aimed to explore their histopathological characteristics.

Material and Methods

Twenty‐five asthmatic patients and 25 nonasthmatic patients with polypoid chronic rhinosinusitis (29 male, 21 female; mean age 41.3 ± 13.27; range 15‐78 years) were enrolled in the study to be compared on the basis of histopathological characteristics. They were compared according to the following seven light microscopic findings: basement membrane thickness, goblet cell hyperplasia, subepithelial edema, submucous gland formation, eosinophilic infiltration, lymphocytic infiltration, and polymorphonuclear infiltration.

Results

Basement membrane thickening, goblet cell hyperplasia, and eosinophilic and lymphocytic infiltration were more prominent in the asthmatic compared with the nonasthmatic group (P < 0.05), whereas polymorphonuclear infiltration was more prominent in nonasthmatics (P < 0.05). No statistically significant differences were found between the two groups with regard to submucosal gland hyperplasia or subepithelial edema.

Conclusion

Asthmatic patients present histopathological characteristics of a marked chronic inflammatory reaction, which might explain the negative effect on chronic rhinosinusitis outcome and the severity of the disease in this group.
The area centralis in the chicken retina contains efferent target amacrine cells
Authors: WELLER CYNTHIA , LINDSTROM SARAH H. , DE GRIP WILLEM J. , WILSON MARTIN
Published: March 2009

The retinas of birds receive a substantial efferent, or centrifugal, input from a midbrain nucleus. The function of this input is presently unclear, but previous work in the pigeon has shown that efferent input is excluded from the area centralis, suggesting that the functions of the area centralis and the efferent system are incompatible. Using an antibody specific to rods, we have identified the area centralis in another species, the chicken, and mapped the distribution of the unique amacrine cells that are the postsynaptic partners of efferent fibers. Efferent target amacrine cells are found within the chicken area centralis and their density is continuous across the border of the area centralis. In contrast to the pigeon retina then, we conclude that the chicken area centralis receives efferent input. We suggest that the difference between the two species is attributable to the presence of a fovea within the area centralis of the pigeon and its absence from that of the chicken.
Textile trade and trade credit in Spain, 1840–1913
Authors: Prat Marc
Published: March 2009

Trade credit - the credit provided by suppliers to firms - can be seen as the second-best solution when financial development fails to keep pace with economic growth. This article analyses trade credit between Catalan cotton manufacturers and their clients in nineteenth-century Spain. Spanish historiography has suggested that trade credit had a detrimental effect on the profitability of the cotton firms. Based on an analysis of the archives of several firms, as well as judicial and notary sources, we present a more optimistic interpretation of the system. Manufacturers were, in fact, acting as their customers' bankers because they were in the best position to perform this function. They built up a good information structure, managed the credit risk efficiently and got positive returns from this activity.
A Controlled Investigation of a Cognitive Behavioural Pain Management Program for Older Adults
Authors: Green Sheryl M. , Hadjistavropoulos Thomas , Hadjistavropoulos Heather , Martin Ronald , Sharpe Donald
Published: March 2009

Background: Although psychosocial treatments for pain have been found to be effective in reducing self-reported pain, physician visits, and in improving mood, the research has largely focused on younger persons. As such, there is a paucity of related studies involving older adults. Method: We implemented and evaluated a 10-session psychosocial (i.e. cognitive behavioural orientation) pain management program that was specifically designed for older adults. The intervention was delivered either in the participants' homes or in bookable rooms in seniors' residence buildings. Ninety-five community dwelling seniors with at least one chronic pain condition were assigned to either a treatment or a wait-list control condition. An assessment battery was administered to treatment participants immediately before the program started, immediately post-treatment, and 3-months post-treatment. Comparable data were obtained from control group participants, although 3-month follow-up data were not available for the control group. Outcome variables included pain intensity, coping strategy usage, pain beliefs/appraisals, and perceived life stressors. Results: Although decreases in pain intensity were observed in both the treatment and wait-list control groups, the intervention was found to result in fewer maladaptive beliefs about pain and greater use of relaxation, which is considered to be an adaptive coping strategy. Conclusions: Although some treatment benefits were identified (e.g. change in pain-related beliefs), future research should test the effectiveness of a cognitive behavioural treatment program tailored for seniors with participants who are experiencing higher pain intensities than those reported by our sample (i.e. those who experience a higher level of pain at baseline may represent a more suitable sample for assessing the effectiveness of our intervention in reducing pain intensity).
FORMAL EPISTEMOLOGY, CONTEXT AND CONTENT: INTRODUCTION TO SPECIAL ISSUE ON RECENT DEVELOPMENTS IN FORMAL EPISTEMOLOGY
Authors: ARLÓ-COSTA HORACIO
Published: March 2009

This special issue presents a series of articles focusing on recent work in formal epistemology and formal philosophy. The articles in the latter category elaborate on the notion of context and content and their relationships. This work is not unrelated to recent developments in formal epistemology. Logical models of context, when connected with the representation of epistemic context, are clearly relevant for many issues considered by formal epistemologists. For example, the semantic framework Joe Halpern uses in his article for this issue has been applied elsewhere to solve problems in interactive epistemology (which can be seen as an active branch of contemporary formal epistemology).
EXPECTED CONTENT
Authors: HELZNER JEFFREY
Published: March 2009

We propose an approach to assigning propositional content to deliberate acts of arbitrary type, as opposed to just speech acts. This approach, which is based on the idea that the content of an act is the decision maker's expectation concerning the change that would take place if the act were to be performed, is shown to be related to the concept of expected utility that has played a central role in various accounts of rationality.
THE LOGIC OF JUSTIFICATION
Authors: ARTEMOV SERGEI
Published: March 2009

We describe a general logical framework, Justification Logic, for reasoning about epistemic justification. Justification Logic is based on classical propositional logic augmented by justification assertionst:Fthat readt is a justification for F. Justification Logic absorbs basic principles originating from both mainstream epistemology and the mathematical theory of proofs. It contributes to the studies of the well-knownJustified True Belief vs. Knowledgeproblem. We state a general Correspondence Theorem showing that behind each epistemic modal logic, there is a robust system of justifications. This renders a new, evidence-based foundation for epistemic logic. As a case study, we offer a resolution of the Goldman–Kripke ‘Red Barn’ paradox and analyze Russell’s ‘prime minister example’ in Justification Logic. Furthermore, we formalize the well-known Gettier example and reveal hidden assumptions and redundancies in Gettier’s reasoning.
A novel approach for characterizing the mixing zone of a saltwater wedge
Authors: Abarca Elena , Clement T. Prabhakar
Published: March 2009

The mixing zone between freshwater and seawater in a coastal aquifer is an important transition region that controls regional groundwater flow dynamics and reactive transport processes. While experimental procedures have been developed to study the movement of salt wedges in aquifers, so far no one has attempted to exclusively map the mixing zone associated with the wedge in a laboratory‐scale aquifer model. We propose a colorimetric experimental method, which employs the reaction between alkaline freshwater and acidic saltwater, to map the mixing zone. The experiment was completed in a two‐dimensional aquifer model to simulate a steady saltwater wedge. We used the density‐dependent flow model SUTRA to simulate these experimental results and to estimate the mixing parameters, i.e., dispersivity coefficients. The results show that the proposed colorimetric technique is a useful experimental approach to visualize and quantify the level of mixing in a saltwater intrusion experiment.
Relationship between polar cap patches and field‐aligned irregularities as observed with an all‐sky airglow imager at Resolute Bay and the PolarDARN radar at Rankin Inlet
Authors: Hosokawa K. , Shiokawa K. , Otsuka Y. , Ogawa T. , St‐Maurice J.‐P. , Sofko G. J. , Andre D. A.
Published: March 2009

Simultaneous two‐dimensional observations of airglow enhancement and radar backscatter from field‐aligned irregularities (FAIs) associated with polar cap patches were conducted. The spatial structure of 630 nm airglow from polar cap patches was imaged using an all‐sky airglow imager at Resolute Bay, Canada, while backscatter echoes from decameter‐scale FAIs were observed using the newly constructed HF Polar Dual Auroral Radar Network (PolarDARN) radar at Rankin Inlet, Canada. Both the airglow enhancement and the radar backscatter appeared within a structured region with the spatial extent of about 500–1000 km. The decameter‐scale FAIs were found to extend over the entire region of airglow enhancement associated with polar cap patches, indicating that the polar patch plasma became almost fully structured soon after initiation (within approximately 20–25 min). These findings imply that some rapid structuring process of the entire patch area is involved in addition to the primary gradient‐drift instabilities.
Magnetic signatures of medium‐scale traveling ionospheric disturbances as observed by CHAMP
Authors: Park Jaeheung , Lühr Hermann , Stolle Claudia , Rother Martin , Min Kyoung Wook , Chung Jong‐Kyun , Kim Yong Ha , Michaelis Ingo , Noja Max
Published: March 2009

In this work we analyze the global distribution and physical characteristics of nighttime midlatitude magnetic field fluctuations (MMFs) as observed by the CHAMP satellite from 2001 to 2002 (solar maximum) and from 2006 to 2007 (solar minimum). MMFs are defined as medium‐scale magnetic fluctuations perpendicular to the mean field, which are not accompanied by plasma density irregularities at the CHAMP altitude (∼400 km). MMFs occur at 15°–40° invariant latitude in the ionospheric F region. The occurrence is rare above the southern Atlantic ocean, and bears little connection to geomagnetic activity. The global MMF occurrence rate depends on season. The occurrence is generally low in equinox, maximizes around east Asia/Oceania and Europe/northern Atlantic Ocean in June solstice, and peaks above the American continents in December solstice. As the solar cycle declines, the detected MMF occurrence rate also decreases. The MMF occurrence peaks around 2100 LT and slowly decreases toward midnight. In the postmidnight sector, events are practically absent. The MMF occurrence is generally consistent with known features of nighttime medium‐scale traveling ionospheric disturbances (MSTIDs), such as the conjugate climatology, and premidnight occurrence peak in the east Asia/Oceania region. But differences in their distributions also exist, implying that factors other than MSTIDs, e.g., ionospheric conductivity, sporadic E layer or plasma instabilities, may play a nonnegligible role in generating MMFs. MMFs have a preferred direction of polarization, which is consistent with that of MSTIDs and again corroborates the close connection between these two phenomena. We interpret the observed magnetic deflections in terms of field‐aligned currents (FACs). The estimated wavelength range (∼200–500 km) of associated FAC pairs also agrees well with the size of MSTID density structures.
Dayside four‐sheet field‐aligned current system during IMF BY‐dominated periods
Authors: Watanabe Masakazu , Sofko George J.
Published: March 2009

When the dawn‐dusk component of the interplanetary magnetic field (IMF BY) is dominant, in particular, for northward IMF, there often appears a field‐aligned current (FAC) system consisting of four latitudinally separated and longitudinally elongated current sheets in the prenoon or postnoon sector, depending on the polarity of IMF BY. A new explanation is proposed for the four‐sheet FAC system in terms of ionospheric convection which includes an exchange cell. In this configuration, in addition to the usual round and crescent convection cells seen during IMF BY‐dominated periods, a small convection cell called the primary exchange cell and having the same circulation direction as the round cell appears in the Northern Hemisphere prenoon (for BY < 0) or postnoon (for BY > 0) sector, equatorward of the round cell. A case study is presented in which a four‐sheet FAC system is successfully explained using the exchange cell configuration. In the observations, however, it often is the case that the primary exchange cell may lose its identity because it is incorporated into the round cell to form one large round cell. We suggest that this incorporation arises from diffusive processes in the magnetosphere‐ionosphere coupling.
Thermal tides in the Martian middle atmosphere as seen by the Mars Climate Sounder
Authors: Lee C. , Lawson W. G. , Richardson M. I. , Heavens N. G. , Kleinböhl A. , Banfield D. , McCleese D. J. , Zurek R. , Kass D. , Schofield J. T. , Leovy C. B. , Taylor F. W. , Toigo A. D.
Published: March 2009

The first systematic observations of the middle atmosphere of Mars (35–80km) with the Mars Climate Sounder (MCS) show dramatic patterns of diurnal thermal variation, evident in retrievals of temperature and water ice opacity. At the time of writing, the data set of MCS limb retrievals is sufficient for spectral analysis within a limited range of latitudes and seasons. This analysis shows that these thermal variations are almost exclusively associated with a diurnal thermal tide. Using a Martian general circulation model to extend our analysis, we show that the diurnal thermal tide dominates these patterns for all latitudes and all seasons.
Venus Express mission
Authors: Svedhem H. , Titov D. , Taylor F. , Witasse O.
Published: March 2009

Venus Express is well and healthy and has now been providing exciting new data from Venus, our nearby twin planet, for over 2 years. Many of the new results are presented and discussed in the subsequent papers in this special section. The overall scientific objective of Venus Express is to carry out a detailed study of the atmosphere of Venus, including the interaction of the upper atmosphere with the solar wind and the interaction of the lowest part of the atmosphere with the surface of the planet. In addition, the plasma environment and magnetic fields as well as some aspects of the surface of the planet are addressed. For the first time, investigations make systematic use of the transparent infrared spectral windows in order to probe the atmosphere in four dimensions: three spatial dimensions plus time. The spacecraft design is taken from Mars Express with some modifications necessary owing to the specific environment around Venus. The payload is composed of three spectrometers, a camera, a magnetometer, an instrument for detecting energetic particles, and a radio science package. The orbit is polar and highly elliptic, with a pericenter altitude of about 200 km over the northern polar region and an apocenter altitude of 66,000 km. Presently, the coverage of the southern hemisphere is very good, but important gaps still do exist. The coverage of the northern hemisphere is much less dense. Venus Express is a part of the European Space Agency's program for the exploration of the inner solar system, which includes missions to study the Sun, Mercury, Venus, the Moon, Mars, and comets and asteroids.
Influence of stratospheric quasi‐biennial oscillation on tropical cyclone tracks in the western North Pacific
Authors: Ho Chang‐Hoi , Kim Hyeong‐Seog , Jeong Jee‐Hoon , Son Seok‐Woo
Published: March 2009

The possible influence of the stratospheric quasi‐biennial oscillation (QBO) on tropical cyclone (TC) passages in the western North Pacific (WNP) is examined using TC data recorded by the Tokyo Typhoon Center and the QBO index derived from reanalysis data. The influence is observed to be significant. The number of TCs approaching the East China Sea is large during the westerly phase of the QBO; however, during the easterly phase, the number of TCs approaching the eastern offshore of Japan is large. This difference in the TC tracks is found to be related to the background flow change associated with the QBO. However, the total number of TC events over the WNP and the sum of the number of TCs approaching the aforementioned two regions appear to be unrelated to the QBO phases.
Monocyte Subtypes Predict Clinical Course and Prognosis in Human Stroke
Authors: Urra Xabier , Villamor Neus , Amaro Sergio , Gómez-Choco Manuel , Obach Víctor , Oleaga Laura , Planas Anna M , Chamorro Angel
Published: March 2009

The number of circulating monocytes increases after stroke. In this study, we assessed the time course and phenotype of monocyte subsets and their relationship with the clinical course and outcome in 46 consecutive stroke patients and 13 age-matched controls. The proportion of the most abundant ‘classical’ CD14highCD16 monocytes did not change after stroke, whereas that of CD14highCD16+ monocytes increased and CD14dimCD16+ monocytes decreased. CD14highCD16 + monocytes had the highest expression of TLR2, HLA-DR and the angiogenic marker, Tie-2; CD14dimCD16+ monocytes had the highest expression of costimulatory CD86 and adhesion molecule CD49d. Platelet-monocyte interactions were highest in CD14highCD16 monocytes and lowest in CD14dimCD16+ monocytes. In adjusted models, 1/CD14highCD16 monocytes were associated with poor outcome (OR: 1.38), higher mortality (OR: 1.40) and early clinical worsening (OR: 1.29); 2/CD14highCD16+ monocytes were inversely related to mortality (OR: 0.32); and 3/CD14dimCD16+ monocytes were inversely related to poor outcome (OR: 0.74) and infarction size ( r= 0.45; P = 0.02). These results illustrate that the predominant monocyte subtype conveys harmful effects after stroke, which include stronger interaction with platelets. Alternatively, rarer subpopulations of monocytes are beneficial with a phenotype that could promote tissue repair and angiogenesis. Therefore, monitoring of monocyte subtypes may emerge as a useful tool at the bedside for stroke patients.
Structure and magnetic properties of L10 FePt film with Ag heat sink layer
Authors: Chen J. S. , Hu J. F. , Lim B. C. , Phyoe W. L. , Liu B. , Ju G.
Published: March 2009

In this work, the L10 FePt films with a Ag heat sink layer for the application of heating assisted magnetic recording (HAMR) were developed. It was found that the crystalline orientation of the FePt layer depended on the texture of the fcc Ag layer, which was strongly affected by the deposition conditions. The (200) textured Ag layer can induce the L10 FePt (001) texture films due to epitaxial growth with the epitaxial growth relationship of FePt (001) [100]//Ag (001) [100]//CrRu (002) [110] and thus can act as the heat sink layer for HAMR application,. The magnetic properties of the L10 FePt films were maintained with the thickness of the Ag heat sink layer from 30 to 100 nm.
Suppression effect of surface fluorination on charge injection into linear low density polyethylene
Authors: An Zhenlian , Yang Qiang , Xie Chen , Jiang Yue , Zheng Feihu , Zhang Yewen
Published: March 2009

To suppress charge injection from electrodes, direct fluorination using fluorine gas was used for linear low density polyethylene (LLDPE) since it is one of the most effective methods of the polymer surface modification. Surface fluorination of the LLDPE plates was obtained as indicated by attenuated total reflection infrared spectroscopy. Remarkable suppression of charge injection by the surface fluorination was observed by space charge distribution measurements using the pressure wave propagation method. Comparing with the remarkable bipolar charge distribution in bulk of the original LLDPE, there is less space charge in bulk and it mostly exists in the fluorinated surface layers. The possible mechanisms of the charge injection suppression are discussed, one of which, the effect of fluorination on the charge traps in surface layer was investigated by the thermally stimulated discharge technique. The results indicate that fluorination has charge traps in the surface layer remarkably deepened and charges captured in the deep traps can block or shield the further charge injection.
Electron microscopy study of front-side Ag contact in crystalline Si solar cells
Authors: Li Z. G. , Liang L. , Cheng L. K.
Published: March 2009

Efficiency of industrial screen-printed silicon solar cells depends critically on their firing conditions. We investigated the microstructure of the Ag/emitter contact of solar cells fired at temperatures from below to above optimal by electron microscopy. We found that the interfacial microstructure evolved from one richly decorated with nanometer-size Ag colloids into one with many Ag crystallites grown onto the emitter surface. Selective etching revealed a dearth of Ag crystallites in optimally fired cells. Our microstructural observations suggest that a tunneling mechanism (likely assisted by nano-Ag colloids) is responsible for current extraction in these cells fired with optimal conditions.
Potentials in a nonuniform quantum dusty magnetoplasma
Authors: Salimullah M. , Zeba I. , Uzma Ch. , Jamil M.
Published: March 2009

Using the quantum hydrodynamic model for quantum magnetoplasmas, the Shukla–Nambu–Salimullah shielding potential and the far-field dynamical wake potential in a quantum dusty plasma with a nonuniform density and ambient static magnetic field have been investigated in detail. The short-range screening potential different from the symmetric Debye–Hückel potential and the long-range oscillatory wake potential are found to be significantly affected by the nonuniformities in the density and the static magnetic field. The far-field oscillatory wake-field potential can explain attraction among the same polarity charges leading to the possible ordered structures or coagulation in the inhomogeneous quantum dusty magnetoplasma.
Phase-change memory devices based on gallium-doped indium oxide
Authors: Wang S.-L. , Chen C.-Y. , Hsieh M.-K. , Lee W.-C. , Kung A. H. , Peng L.-H.
Published: March 2009

We report repetitive phase-change memory (PCM) activity via the high- to low-resistance state transition in gallium-doped indium oxide (Ga:InO) induced by nanosecond electric pulses. The amorphous-to-crystalline phase transition of Ga:InO is found to occur at a crystallization temperature of ∼250 °C with an activation energy of 1.27±0.07 eV. At the phase transition, we observe a change in two orders of magnitude in the PCM-device resistance, which can be correlated with the formation of (211) and {222} crystallites of bixbyite cubic In2O3. We ascribe the phase-change mechanism to the Joule heating effect in Ga:InO.
Pt metal-CeO2 interaction: Direct observation of redox coupling between Pt/Pt2+/Pt4+ and Ce4+/Ce3+ states in Ce0.98Pt0.02O2−δ catalyst by a combined electrochemical and x-ray photoelectron spectroscopy study
Authors: Sharma Sudhanshu , Hegde M. S.
Published: March 2009

Pt ions-CeO2 interaction in Ce1−xPtxO2−δ (x=0.02) has been studied for the first time by electrochemical method combined with x-ray diffraction and x-ray photoelectron spectroscopy. Working electrodes made of CeO2 and Ce0.98Pt0.02O2−δ mixed with 30% carbon are treated electrochemically between 0.0–1.2 V in potentiostatic (chronoamperometry) and potentiodynamic (cyclic voltametry) mode with reference to saturated calomel electrode. Reversible oxidation of Pt0 to Pt2+ and Pt4+ state due to the applied positive potential is coupled to simultaneous reversible reduction of Ce4+ to Ce3+ state. CeO2 reduces to CeO2−y (y=0.35) after applying 1.2 V, which is not reversible; Ce0.98Pt0.02O2−δ reaches a steady state with Pt2+:Pt4+ in the ratio of 0.60:0.40 and Ce4+:Ce3+ in the ratio of 0.55:0.45 giving a composition Ce0.98Pt0.02O1.74 at 1.2 V, which is reversible. Composition of Pt ion substituted compound is reversible between Ce0.98Pt0.02O1.95 to Ce0.98Pt0.02O1.74 within the potential range of 0.0–1.2 V. Thus, Ce0.98Pt0.02O2−δ forms a stable electrode for oxidation of H2O to O2 unlike CeO2. A linear relation between oxidation of Pt2+ to Pt4+ with simultaneous reduction in Ce4+ to Ce3+ is observed demonstrating Pt–CeO2 metal support interaction is due to reversible Pt0/Pt2+/Pt4+ interaction with Ce4+/Ce3+ redox couple.
Work function engineering in low-temperature metals
Authors: Orf Nicholas D. , Baikie Iain D. , Shapira Ofer , Fink Yoel
Published: March 2009

Semiconductor devices require conducting electrodes with disparate work functions for their operation. Of recent interest are fluidic processing approaches for large-area devices, which present unique challenges in the identification of materials having disparate work functions but similar melting temperatures. Such materials may be engineered by alloying with low-melting temperature metals. As a demonstration, the work function of tin and four binary tin alloys is measured by ultraviolet photoemission spectroscopy and Kelvin probe method. We demonstrate the control of metal work function by 600 meV through alloying while keeping the melting temperature within a 140 °C range.
Electrical transport and mechanical properties of alkylsilane self-assembled monolayers on silicon surfaces probed by atomic force microscopy
Authors: Park Jeong Young , Qi Yabing , Ashby Paul D. , Hendriksen Bas L. M. , Salmeron Miquel
Published: March 2009

The correlation between molecular conductivity and mechanical properties (molecular deformation and frictional responses) of hexadecylsilane self-assembled monolayers was studied with conductive probe atomic force microscopy/friction force microscopy in ultrahigh vacuum. Current and friction were measured as a function of applied pressure, simultaneously, while imaging the topography of self-assembled monolayer molecule islands and silicon surfaces covered with a thin oxide layer. Friction images reveal lower friction over the molecules forming islands than over the bare silicon surface, indicating the lubricating functionality of alkylsilane molecules. By measuring the tunneling current change due to changing of the height of the molecular islands by tilting the molecules under pressure from the tip, we obtained an effective conductance decay constant (β) of 0.52/Å.
A synergetic description of carbon nanofiber growth
Authors: Merkulov I. A. , Klein K. L. , Simpson M. L.
Published: March 2009

A self-consistent mathematical model of the growth of carbon nanofiber in a catalytic chemical vapor deposition process has been developed. This model includes the balance equation for carbon transport through the catalyst and the equation for mechanical and chemical balance in the catalyst-nanofiber system. It is demonstrated that the most important parameter that governs the nanofiber growth behavior is the difference in the carbon chemical potentials in the catalyst and nanofiber. This parameter determines the carbon transport to the nanofiber. It is also responsible for the catalyst shape and topology of the interface between the catalyst and nanofiber. The solutions of the model are in qualitative agreement with numerous experimental results. The model can be used in designing experiments and explaining existing results. It leaves the opportunity for more a precise and complex mathematical calculation of different aspects of the growth process.
Thyristor stack for pulsed inductive plasma generation
Authors: Teske C. , Jacoby J. , Schweizer W. , Wiechula J.
Published: March 2009

A thyristor stack for pulsed inductive plasma generation has been developed and tested. The stack design includes a free wheeling diode assembly for current reversal. Triggering of the device is achieved by a high side biased, self supplied gate driver unit using gating energy derived from a local snubber network. The structure guarantees a hard firing gate pulse for the required high dI/dt application. A single fiber optic command is needed to achieve a simultaneous turn on of the thyristors. The stack assembly is used for switching a series resonant circuit with a ringing frequency of 30 kHz. In the prototype pulsed power system described here an inductive discharge has been generated with a pulse duration of 120 μs and a pulse energy of 50 J. A maximum power transfer efficiency of 84% and a peak power of 480 kW inside the discharge were achieved. System tests were performed with a purely inductive load and an inductively generated plasma acting as a load through transformer action at a voltage level of 4.1 kV, a peak current of 5 kA, and a current switching rate of 1 kA/μs.
Conversion of near-ultraviolet radiation into visible and infrared emissions through energy transfer in Yb2O3 doped SrO–TiO2–SiO2 glasses
Authors: Ye Song , Zhu Bin , Liu Yin , Teng Yu , Lin Geng , Lakshminarayana Gandham , Fan Xianping , Qiu Jianrong
Published: March 2009

We demonstrated the conversion of near-ultraviolet radiation of 250–350 nm into visible emission of 450–600 nm and near-infrared emission of 970–1100 nm in the Yb2O3 doped transparent 40SrO-20TiO2-40SiO2 glasses. The observed broad visible emission band centered at 510 nm is associated with silicon-oxygen-related defects in the glassy matrix, and the near-infrared emission originated from the Yb3+ F25/2→F27/2 transition is due to the energy transfer from silicon-oxygen-related defects to Yb3+. The energy transfer process was studied by both the steady state spectra and the time-resolved spectra of Yb3+ at 15 K. The temperature dependent energy transfer rate was calculated. The Yb2O3 concentration dependent energy transfer efficiency has also been evaluated, and the maximum value is 56% for 12 mol % Yb2O3 doped glass.
High-rate reactive ion etching of barium hexaferrite films using optimal CHF3/SF6 gas mixtures
Authors: Chen Zhaohui , Yang Aria , Xie Changqing , Yang Qinghua , Vittoria C. , Harris V. G.
Published: March 2009

The high-rate reactive ion etching of c-axis oriented quasi-single-crystal barium hexaferrite (BaM) films, deposited on 6-H silicon carbide (0001) substrates, has been demonstrated. Arrays of BaM columns, having diameters of 1–4 μm and sharp vertical walls, were etched from BaM films at rates as high as 75 nm/min using an optimized sulfur hexafluoride and methyl trifluoride (SF6:CHF3, 3:1) gas mixture. Lateral features as small as 43 nm were fabricated and imaged.
Anisotropy of the superconducting transport properties of the LaAlO3/SrTiO3 interface
Authors: Reyren N. , Gariglio S. , Caviglia A. D. , Jaccard D. , Schneider T. , Triscone J.-M.
Published: March 2009

The superconducting transport properties of the conducting LaAlO3/SrTiO3 interface have been investigated in perpendicular and parallel magnetic fields. A large anisotropy in the transport properties is measured and the two-dimensional nature of the superconducting gas is confirmed. Analyses of the resistance versus temperature and magnetic field, as well as of the correlation length as a function of the magnetic field close to the superconducting critical temperature (about 200 mK), yield an estimate of ∼10 nm for the superconducting layer thickness.
Reduction of phonon resonant terahertz wave absorption in photoconductive switches using epitaxial layer transfer
Authors: Kasai S. , Katagiri T. , Takayanagi J. , Kawase K. , Ouchi T.
Published: March 2009

A broadband terahertz time-domain spectroscopy (TDS) system for frequencies of up to 15 THz, including the phonon resonance frequency range, has been developed using a transferred thin-film photoconductive switch (PCS) detector. The thin-film PCSs, based on low-temperature-grown GaAs, were fabricated using epitaxial layer transfer onto high-resistivity Si substrates. We observed a reduction of phonon resonant absorption, including between 7 and 10 THz, in a forward radiation configuration. Numerically calculated absorption spectra show good agreement with our experimental results. This technique will provide compact, broadband TDS systems.
All-chalcogenide glass omnidirectional photonic band gap variable infrared filters
Authors: Kondakci H. Esat , Yaman Mecit , Koylu Ozlem , Dana Aykutlu , Bayindir Mehmet
Published: March 2009

We report on the design, fabrication, and characterization of spatially variable infrared photonic band gap filter that consists of thermally evaporated, high refractive index contrast, amorphous chalcogenide glass multilayers. Due to graded thickness structure, the filter exhibits a position dependent stop band and a cavity mode ranging from 1.8 to 3.4 μm wavelengths. Reflection measurements on the variable filter agree well with theoretical calculations. These results pave the way to low-loss infrared mirrors, filters, spectral imaging, and miniaturized spectrometers at infrared region.
Interplay of α-synuclein binding and conformational switching probed by single-molecule fluorescence
Authors: Ferreon Allan Chris M. , Gambin Yann , Lemke Edward A. , Deniz Ashok A.
Published: March 2009

We studied the coupled binding and folding of α-synuclein, an intrinsically disordered protein linked with Parkinson's disease. Using single-molecule fluorescence resonance energy transfer and correlation methods, we directly probed protein membrane association, structural distributions, and dynamics. Results revealed an intricate energy landscape on which binding of α-synuclein to amphiphilic small molecules or membrane-like partners modulates conformational transitions between a natively unfolded state and multiple α-helical structures. α-Synuclein conformation is not continuously tunable, but instead partitions into 2 main classes of folding landscape structural minima. The switch between a broken and an extended helical structure can be triggered by changing the concentration of binding partners or by varying the curvature of the binding surfaces presented by micelles or bilayers composed of the lipid-mimetic SDS. Single-molecule experiments with lipid vesicles of various composition showed that a low fraction of negatively charged lipids, similar to that found in biological membranes, was sufficient to drive α-synuclein binding and folding, resulting here in the induction of an extended helical structure. Overall, our results imply that the 2 folded structures are preencoded by the α-synuclein amino acid sequence, and are tunable by small-molecule supramolecular states and differing membrane properties, suggesting novel control elements for biological and amyloid regulation of α-synuclein.