bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal induced crystallized poly-Si Thin Films and Thin Film Transistors
Authors: Wu Chunya , Meng Zhiguo , Zhao Shuyun , Li Xuedong , Liu Zhaojun , Li Juan , Wang Man , Kwok Hoi Sing , Xiong Shaozhen
Published: July 2009

Metal induced crystallization of a-Si was implemented by using nickel salt solution, nickel silicon oxide mixture, and a nano-layer of SiO2 mask. By using salt solution to form nickel media, the crystallization of a-Si started from many isolated sites and proceeded along radial directions at the isotropical crystallization rate under the optimized soaking conditions. By using nickel silicon oxide mixture, the crystallization of a-Si behaved an effect of self-controlled release of nickel, the poly-Si had low nickel residua under the induce holes and at the domain boundaries. By using a nano-layer of SiO2 mask to pre-define nucleation lines, the poly-Si composing of continuous zonal domain in exactly same width was obtained, the crystallization of a-Si started from some isolated sites inside the inducing windows, then proceeded along radial/lateral direction outside the windows. The characteristics of poly-Si TFTs made with these three different schemes were analyzed.
Stability Study of ZnO TFT using a Simple and Effective Model
Authors: Dong Chengyuan , Li Junfeng , Jin Bo , Bub Dongsheng , Su Yikai
Published: July 2009

ZnO TFT is one of the promising candidates as next-generation active addressing devices for FPD. However, its stability has rarely been investigated. Since the microscopic mechanism in the degradation process of ZnO TFT is not clear, a phenomenological model to describe the degradation effect is needed. In this paper, we build a simple yet effective model to investigate the degradation effect of ZnO TFT, where we assume that only charge trapping contributes to the instability. The increasing rate of the trapped charge is assumed to be proportional to the difference between the gate voltage and the initial threshold voltage, and inversely proportional to the number of the electrons already trapped. The simulation results agree well with the experimental data for different stressing conditions, proving that our model is effective to investigate the degradation effect in ZnO TFTs. The significations of some key parameters in our model are also discussed.
Model and Key Fabrication Technologies for FeRAM
Authors: Ren TianLing , Zhang Ming-Ming , Jia Ze , Wang Lin-Kai , Wei Chao-Gang , Xue Kan-Hao , Zhang Ying-Jie , Hu Hong , Xie Dan , Liu Li-Tian
Published: July 2009

Ferroelectric random access memory (FeRAM) is believed to be one of the most promising candidates for the next generation non-volatile memory due to its fast access time and low power consumption. Circuit design and fabrication are the main two parts of FeRAM technologies. And models to describe hysteresis Q-V characteristic of ferroelectric capacitor are the key for the design of FeRAM. The arc tangent function is used to describe hysteresis loop. And compact equivalent circuits are introduced to integrate this model into HSPICE for circuit simulation. Some key fabrication technologies are presented. Iridium (Ir) is studied as electrodes to improve the fatigue property of PZT based capacitors. A metal organic chemical vapor deposition (MOCVD) process is developed to fabricate high quality Pb(Zr1-xTix)O3 (PZT) films.
Down-scaling of Thin-Film Transistors: Opportunities and Design Challenges
Authors: Guo Xiaojun , Sporea Radu , Shannon John , Silva S. R.
Published: July 2009

With the ever-increasing demands for integration of advanced electronic functions into large-area electronics, down-scaling of thin-film transistors (TFTs) becomes very necessary. The key device operational issues associated with TFT scaling, including short-channel effects (SCEs) and self-heating, are considered in this paper. Device structure engineering approaches are introduced to suppress the SCEs for designing short-channel TFTs with excellent digital and analog performance. And electro-thermal simulation results show that the self-heating in TFTs will be much more significant than that in silicon metal-oxide-semiconductor field-effect transistors (MOSFETs) due to the substrate of poor thermal conductivity. Enhancing the heat dissipation by placement of metal heat pipe in the cap dielectric layers is proved to be an effective way to deal with the heating issues.
Bipolar Device and Circuit Technologies for Future Wireless Communications
Authors: Washio Katsuyoshi , Shiramizu Nobuhiro , Miura Makoto , Nakamura Takahiro , Oda Katsuya , Masuda Toru
Published: July 2009

SiGe HBTs and their circuit technologies are suitable for future wireless communications. To achieve low 1/f-noise characteristics in RF applications, a SiGe HBT with a raised-emitter structure, fabricated by epitaxial growth of phosphorous-doped Si layers, was developed. Aimed at ultra-low power consumption in a wide range of microwave applications, a SiGe HBT fabricated by well-controlled SiGe/Si continuous epitaxial growth was developed. To improve the design process for Si-based RF-ICs, equivalent circuits for transmission lines under the slow-wave effect and for inductors under the peripheral ground effect were also demonstrated. Moreover, MMICs operating in the quasi-millimeter-wave region, namely, a 24-GHz LNA, a 27-GHz VCO, and a 24-GHz mixer were developed. In regards to these MMICs, new circuit technologies, namely, inductive biasing, merged transformer matching, and pseudo-stacked configuration, were developed.
Novel Asymmetric Tunneling Devices for Low Power ULSI
Authors: Venkatagirish Nagavarapu , Tura Ahmet , Jhaveri Ritesh , Chang Hsu-Yu , Woo J. C.
Published: July 2009

A novel device concept, the Tunnel Source (PNPN) n-MOSFET, based on the principle of band-to-band tunneling is presented in this paper. A narrow fully depleted n+ pocket at the source reduces the tunneling width as well as the potential drop at the source. As a result, this device can achieve steep sub-threshold swing (~5mv/dec) with low IOFF and improved ION over p-i-n tunneling FETs and can thus be a potential solution for low power ULSI applications.
SOI CMOS Platform for Gas Sensing Applications
Authors: Milne William I. , Santra Sumita , Udrea Florin , Ali Syed , Guha Prasanta , Vieira Sara , Maeng Sunglyul , Gardner Julian
Published: July 2009

In this paper, we review the work carried out at Cambridge University, in the UK, to develop a CMOS gas sensor. Special emphasis is put on the design of low power CMOS micro-hotplates and local growth of nanomaterials: carbon nanotubes (CNTs), CNT polymer composites and zinc oxide (ZnO) nanowires (NWs) on fully processed CMOS substrates. Finally some gas test results are also included.
Vertical Channel Thin Film Transistor Technology: Similar Approach with 3D-ULSI Monolithic Technology
Authors: Bonnaud Olivier
Published: July 2009

The previous thin film transistor studies involved planar process that means channel parallel to the substrate surface. Another way passes by a modification of the spatial geometry, more especially by the creation of vertical channels. This allows an increase of the equivalent current density flowing in the circuit thanks to two major modifications, the channel length that can be much shorter and the channel width that can be much higher, for the same design rules and for the same substrate area. The approach is thus similar to the recent evolution of the monolithic silicon technology. After the presentation of the interest of such vertical channel ways on both ULSI and thin film technologies, results on vertical TFTs are presented and discussed. We finally give comments on the common approaches between nano- and giga-electronics involving three dimensional geometry, in order to show that their basic scientific principles are roughly the same.
Fabrication and Transport Behavior Investigation of Gate-All-Around Silicon Nanowire Transistor from Top-Down Approach
Authors: Huang Ru , Wang Runsheng , Tian Yu , Zhuge Jing , Zhang Liangliang , Liu Changze , Wang Yiqun , Ai Yujie , Wang Yangyuan
Published: July 2009

Gate-all-around silicon nanowire transistor (SNWT) can be considered as the potential candidate for highly scaled devices. This paper mainly discusses a new process integration scheme, which features bulk substrate based, epi-free integration, self-aligned structure and large source/drain fan-out. The characteristics of the fabricated device with 10nm diameter nanowire were investigated. The transport behavior of the SNWTs is experimentally estimated, with a modified experimental extraction methodology for SNWTs given, which takes into account the impact of temperature dependence of parasitic resistance. The sub-40nm SNWTs exhibit high ballistic efficiency at room temperature. Self-heating effect is also experimentally characterized and due to the 1-D nature of nanowire and increased phonon-boundary scattering in GAA structure, the self-heating effect in SNWTs based on bulk substrate is comparable or even a little bit worse than SOI devices, which may limit the ultimate performance of SNWT-based circuits and thus special design consideration is expected.
Breakdown of Small Diameter Si Nanowires under External Electric Field: First-principle Calculation
Authors: Zhang Renqin , Gao Nan , Wen Zi , Jiang Qing
Published: July 2009

The electronic and structural properties of [111] SiNWs with a diameter range of D = 0.66-1.89 nm under the external electric field along axial direction are calculated using first-principle calculation. With the external electric field applied, energy band gap Eg(D,F) decreases and finally closes, as F increases. The closure strength of external electric field Fclosure decreases with increasing D. HOMO, LUMO and Mulliken charge analysis are shown to interpret the effect of external electric field on the electronic properties of SiNWs. The bond length and angle of Si atoms vary with increasing F. Further increasing of F results in breakdown of the geometry structure, which is size-dependent.
Adventures in Cardiovascular Research
Authors: Braunwald Eugene
Published: July 2009

This article, derived from an invited Distinguished Scientist lecture presented at the American Heart Association Scientific Sessions in 2007, reviews 4 themes (adventures) in clinical cardiovascular research carried out over a period of 58 years. It begins with the author’s introduction to cardiovascular hemodynamics during a medical school elective in 1951. The 4 adventures include valvular heart disease, hypertrophic cardiomyopathy, heart failure (HF), and myocardial ischemia. In each of these adventures, the author describes briefly what was known when he entered each field, followed by the author’s contribution to the field (the adventure), and ends with comments about the current status of the field. Of particular interest are the changes in the technologies used in clinical cardiovascular research over the past half century, commencing with pressure tracings in left heart chambers with the use of needle puncture in the operating room to genetic technologies designed to understand differences between drugs that inhibit platelet activation. The article ends with some general comments on conducting research and the rewards that can come with this activity.
Estimation of Tropical Cyclone Wind Hazard for Darwin: Comparison with Two Other Locations and the Australian Wind-Loading Code
Authors: Cook Garry D. , Nicholls Michael J.
Published: July 2009

The passage of three Australian Category 5 cyclones within 350 km of Darwin (Northern Territory), Australia, during the last decade indicates that that city should have a high wind hazard. In this paper, the wind hazard for Darwin was compared with that for Port Hedland (Western Australia) and Townsville (Queensland) using data from a coupled ocean–atmosphere simulation model and from historical and satellite-era records of tropical cyclones. According to the authoritative statement on wind hazard in Australia, Darwin’s wind hazard is the same as Townsville’s but both locations’ hazards are much less than that of Port Hedland. However, three different estimates in this study indicate that Darwin’s wind hazard at the long return periods relevant to engineering requirements is higher than for both Port Hedland and Townsville. The discrepancy with previous studies may result from the inadequate cyclone records in the low-latitude north of Australia, from accumulated errors from estimates of wind speeds from wind fields and wind–pressure relationships, and from inappropriate extrapolations of short-period records based on assumed probability distributions. It is concluded that the current wind-hazard zoning of northern Australia seriously underestimates the hazard near Darwin and that coupled ocean–atmosphere simulation models could contribute to its revision.
A Method to Detect Inhomogeneities in Historical Dewpoint Temperature Series
Authors: Brown Paula J. , DeGaetano Arthur T.
Published: July 2009

Hourly dewpoint temperature data for the 1951–2006 period at 10 stations in the contiguous United States were investigated to determine if inhomogeneities in their records could be detected. At least three instrument changes are known to have occurred during this time period. The relatively sparse network of stations with dewpoint temperature data in the United States necessitated a nonconventional method to create a reference series. Utilizing nighttime occurrences of fog, clear/calm conditions, and precipitation as meteorological situations during which dewpoint temperatures and minimum temperatures are similar, three potential reference series based on daily minimum temperature were developed to test for inhomogeneities. Four stations with independent network neighbors recording hourly dewpoint data provided a direct validation of the effect of inhomogeneities on dewpoint temperatures. It was determined that fog conditions and the combined results from all three meteorologically based tests performed best when detecting documented inhomogeneities. However, a larger number of undocumented inhomogeneities, a feature common in most traditional inhomogeneity tests, were also detected that may or may not be valid.
Simulation of Snow Water Equivalent (SWE) Using Thermodynamic Snow Models in Québec, Canada
Authors: Langlois A. , Kohn J. , Royer A. , Cliche P. , Brucker L. , Picard G. , Fily M. , Derksen C. , Willemet J. M.
Published: July 2009

Snow cover plays a key role in the climate system by influencing the transfer of energy and mass between the soil and the atmosphere. In particular, snow water equivalent (SWE) is of primary importance for climatological and hydrological processes and is a good indicator of climate variability and change. Efforts to quantify SWE over land from spaceborne passive microwave measurements have been conducted since the 1980s, but a more suitable method has yet to be developed for hemispheric-scale studies. Tools such as snow thermodynamic models allow for a better understanding of the snow cover and can potentially significantly improve existing snow products at the regional scale.

In this study, the use of three snow models [SNOWPACK, CROCUS, and Snow Thermal Model (SNTHERM)] driven by local and reanalysis meteorological data for the simulation of SWE is investigated temporally through three winter seasons and spatially over intensively sampled sites across northern Québec. Results show that the SWE simulations are in agreement with ground measurements through three complete winter seasons (2004/05, 2005/06, and 2007/08) in southern Québec, with higher error for 2007/08. The correlation coefficients between measured and predicted SWE values ranged between 0.72 and 0.99 for the three models and three seasons evaluated in southern Québec. In subarctic regions, predicted SWE driven with the North American Regional Reanalysis (NARR) data fall within the range of measured regional variability. NARR data allow snow models to be used regionally, and this paper represents a first step for the regionalization of thermodynamic multilayered snow models driven by reanalysis data for improved global SWE evolution retrievals.
Anisotropic Material Transport by Eddies and Eddy-Driven Currents in a Model of the North Atlantic
Authors: Kamenkovich Igor , Berloff Pavel , Pedlosky Joseph
Published: July 2009

This study analyzes anisotropic properties of the material transport by eddies and eddy-driven zonal jets in a general circulation model of the North Atlantic through the analysis of Lagrangian particle trajectories. Spreading rates—defined here as half the rate of change in the particle dispersion—in the zonal direction systematically exceed the meridional rates by an order of magnitude. Area-averaged values for the upper-ocean zonal and meridional spreading rates are approximately 8100 and 1400 m2 s−1, respectively, and in the deep ocean they are 2400 and 200 m2 s−1. The results demonstrate that this anisotropy is mainly due to the action of the transient eddies and not to the shear dispersion associated with the time-mean jets. This property is consistent with the fact that eddies in this study have zonally elongated shapes. With the exception of the upper-ocean subpolar gyre, eddies also cause the superdiffusive zonal spreading, significant variations in the spreading rate in the vertical and meridional directions, and the difference between the westward and eastward spreading.
Accuracy of the IMET Sensor Package in the Subtropics
Authors: Colbo Keir , Weller Robert A.
Published: July 2009

The accuracies of the meteorological sensors (air temperature, relative humidity, barometric pressure, near-surface temperature, longwave and shortwave radiation, and wind speed and direction) that compose the Improved Meteorological (IMET) system used on buoys at long-term ocean time series sites known as ocean reference stations (ORS) are analyzed to determine their absolute error characteristics. The predicted errors are compared to in situ measurement discrepancies and other observations (direct flux shipboard sensors) to confirm the predictions. The meteorological errors are then propagated through bulk flux formulas and the Coupled Ocean–Atmosphere Response Experiment (COARE) algorithm to give predicted errors for the heat flux components, the freshwater flux, and the momentum flux. Absolute errors are presented for three frequency bands [instantaneous (1-min sampling), diurnal, and annual]. The absolute uncertainty in the annually averaged net heat flux is found to be 8 W m−2 for conditions similar to the current ORS deployments in the subtropics.
Prediction of Dry-Season Precipitation in Tropical West Africa and Its Relation to Forcing from the Extratropics
Authors: Knippertz Peter , Fink Andreas H.
Published: July 2009

Precipitation during the boreal winter dry season in tropical West Africa is rare but occasionally results in significant impacts on the local population. The dynamics and predictability of this phenomenon have been studied very little. Here, a statistical evaluation of the climatology, dynamics, and predictions of dry-season wet events is presented for the region 7.5°–15°N, 10°W–10°E. The analysis is based upon Global Precipitation Climatology Project (GPCP) merged satellite–gauge pentad rainfall estimates and 5-day 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) precipitation forecasts, and covers the 23 dry seasons (November–February) during 1979/80–2001/02. Wet events are defined as pentads with an area-averaged precipitation anomaly of more than +200% with respect to the mean seasonal cycle. Composites of the 43 identified events indicate an association with a trough over northwestern Africa, a tropical plume on its eastern side, unusual precipitation at the northern and western fringes of the Sahara, and reduced surface pressure over the Sahara, which allows an inflow of moist southerlies from the Gulf of Guinea to feed the unusual dry-season rainfalls. The results give evidence for a preconditioning by another disturbance about 1 week prior to the precipitation event. The ERA-40 forecasts show a high temporal correlation with observations, a general wet bias, but a somewhat too low number of wet events. With 53% of all identified events correctly forecasted and only 32% of forecasted events not verified, the model shows moderate skill in contrast to the prediction of many other tropical precipitation systems. A separate consideration of hits, misses, and false alarms corroborates the previously proposed hypothesis that a strong extratropical influence enhances the quality of predictions in this region. The results should encourage weather services in West Africa to take advantage of available dry-season precipitation forecasts in terms of the dissemination of early warnings.
Three Spatial Verification Techniques: Cluster Analysis, Variogram, and Optical Flow
Authors: Marzban Caren , Sandgathe Scott , Lyons Hilary , Lederer Nicholas
Published: July 2009

Three spatial verification techniques are applied to three datasets. The datasets consist of a mixture of real and artificial forecasts, and corresponding observations, designed to aid in better understanding the effects of global (i.e., across the entire field) displacement and intensity errors. The three verification techniques, each based on well-known statistical methods, have little in common and, so, present different facets of forecast quality. It is shown that a verification method based on cluster analysis can identify “objects” in a forecast and an observation field, thereby allowing for object-oriented verification in the sense that it considers displacement, missed forecasts, and false alarms. A second method compares the observed and forecast fields, not in terms of the objects within them, but in terms of the covariance structure of the fields, as summarized by their variogram. The last method addresses the agreement between the two fields by inferring the function that maps one to the other. The map—generally called optical flow—provides a (visual) summary of the “difference” between the two fields. A further summary measure of that map is found to yield useful information on the distortion error in the forecasts.
Did St Jerome Have a Near-death Experience?
Authors: Fuller Michael
Published: July 2009

This article is concerned with a remarkable experience recounted by St Jerome, which has a number of features associated with reports of `near-death experiences' (NDEs). Curiously, commentators who have explored patristic and mediaeval accounts of NDEs have hitherto neglected this account. The aetiology and significance of NDEs is disputed; however, it is likely that the negative aspects of St Jerome's vision were influential on subsequent Christian reflections on judgement and the afterlife.
Five-year-olds' book talk and story retelling: Contributions of mother—child joint bookreading
Authors: Kang Jennifer Yusun , Kim Young-Suk , Pan Barbara Alexander
Published: July 2009

This study examined the participation of preschool children (mean age 5;1) in two literacy-related activities — talking about a book with their mothers and subsequent independent retelling of the story. Sixty-two mother—child dyads from low-income families participated. Analysis of bookreading and story retelling transcripts revealed wide variability in extratextual talk during bookreading by both children and mothers. Children's responsive, but not spontaneous, extratextual book talk was closely associated with maternal types of talk. Children's story retelling skills were not related to the types of talk they produced during bookreading, but were predicted by the extent to which mothers encouraged their active participation during joint bookreading. Implications for bookreading intervention programs are discussed.
An investigation into Malay numeral classifier acquisition through an elicited production task
Authors: Salehuddin Khazriyati , Winskel Heather
Published: July 2009

The act of categorization and labeling is fundamental in human cognition and language development. By studying numeral classifier acquisition, researchers are able to examine how children learn to categorize and label objects in their environment using a constrained framework. The current study investigated the acquisition of eight shape-based numeral classifiers in Malay through an elicited production task in 140 6- to 9-year-old children. The aim was to examine the developmental patterns observed in the production of Malay shape-based numeral classifiers. Results indicated that the ability to produce the correct numeral classifiers is a relatively prolonged process that involves an interaction of a variety factors, including semantic complexity, input frequency, and the formal teaching of numeral classifiers in school.
Evaluation Use
Authors: Fleischer Dreolin N. , Christie Christina A.
Published: July 2009

This paper presents the results of a cross-sectional survey on evaluation use completed by 1,140 U.S. American Evaluation Association members. This study had three foci: evaluators' current attitudes, perceptions, and experiences related to evaluation use theory and practice, how these data are similar to those reported in a previous study conducted by Preskill and Caracelli (1997), and to identify characteristics that distinguish high endorsers of use items from others in the sample. Findings suggest a fair level of agreement on several dimensions of use including stakeholder involvement, factors that influence use, and the varied roles of the evaluator. Logistic regression results indicated that external evaluators were less likely to be high item endorsers while those who reported being members of the Evaluation Use Topical Interest Group of the American Evaluation Association were more likely to be high item endorsers.
Emphasizing Cultural Competence in Evaluation
Authors: Botcheva Luba , Shih Johanna , Huffman Lynne C.
Published: July 2009

This paper describes a process-oriented approach to culturally competent evaluation, focusing on a case study of an evaluation of an HIV/AIDS educational program in Bulawayo, Zimbabwe. We suggest that cultural competency in evaluation is not a function of a static set of prescribed steps but is achieved via ongoing reflection, correction, and adaptation. The aim of these processes is to attain the ``best fit'' possible between evaluation goals, methods, and cultural context. Three main ingredients in a process-oriented approach to culturally competent evaluation are discussed: collaboration, reflective adaptation, and contextual analysis. In addition, since evaluators face constraints set by funders and other stakeholders, we suggest that cultural competence is best viewed as a continuum. An evaluator's goal should be to ``move across the continuum'' in order to achieve the highest level of cultural competency possible given the unique parameters of every evaluation.
The Strength of the Methodological Warrants for the Findings of Research on Program Evaluation Use
Authors: Brandon Paul R. , Singh J. Malkeet
Published: July 2009

Considerable research has been conducted on the use of the findings of program evaluation, but little, if any, attention has been paid to the soundness of the methods of this research. If the methods are not sound or not well described in the research, the strength of the conclusions of the research is unknown. The authors examine the empirical studies reported in five widely cited reviews of the literature on program evaluation use and summarize the types of methods used, the professions for which they were conducted, and the extent to which they met two basic criteria for soundness. It was concluded that, by and large, the body of studies does not adequately address the criteria. With care, the findings of the research literature on the use of evaluations might provide guidance for evaluators, but they lack sufficient scientific credibility for other uses.
A Reliability Analysis of Goal Attainment Scaling (GAS) Weights
Authors: Marson Stephen M. , Guo Wei  , Wasserman Deborah
Published: July 2009

Goal attainment scaling (GAS) has been considered to be one of the most versatile and appealing evaluation protocols available for human services. Aspects of the protocol that make the method so appealing to practitioners—that is, collaboratively working with individual clients to identify and assign weights to goals they will work to achieve—have produced critical psychometric challenges that have threatened the method's acceptance by funders and researchers. This interrater reliability study of weighted goals contributes to their psychometric validation and therefore to the continued use of a methodology so attractive to practitioners. The subjective clinical impressions of 43 students trained in using GAS has statistically significant scorer reliability. These findings suggest that use of GAS composite scores (weight times the problem level) is a reliable tool and therefore not a reason to discourage the use of GAS as a means for monitoring a client's progress over time.
Lymphomas with concurrent BCL2 and MYC translocations: the critical factors associated with survival
Authors: Johnson Nathalie A. , Savage Kerry J. , Ludkovski Olga , Ben-Neriah Susana , Woods Ryan , Steidl Christian , Dyer Martin J. S. , Siebert Reiner , Kuruvilla John , Klasa Richard , Connors Joseph M. , Gascoyne Randy D. , Horsman Douglas E.
Published: July 2009

BCL2 and MYC are oncogenes commonly deregulated in lymphomas. Concurrent BCL2 and MYC translocations (BCL2+/MYC+) were identified in 54 samples by karyotype and/or fluorescence in situ hybridization with the aim of correlating clinical and cytogenetic characteristics to overall survival. BCL2+/MYC+ lymphomas were diagnosed as B-cell lymphoma unclassifiable (BCLU; n = 36) with features intermediate between Burkitt lymphoma and diffuse large B-cell lymphoma (DLBCL); DLBCL (n = 17), or follicular lymphoma (n = 1). Despite the presence of a t(14;18), 5 cases were BCL2 protein–negative. Nonimmunoglobulin gene/MYC (non-IG/MYC) translocations occurred in 24 of 54 cases (44%) and were highly associated with DLBCL morphology (P < .001). Over a median follow-up of 5.3 years, 6 patients remained in remission and 32 died within 6 months of the MYC+ rearrangement, irrespective of whether MYC+ occurred at diagnosis (31 of 54) or transformation (23 of 54; P = .53). A non-IG/MYC translocation partner, absent BCL2 protein expression and treatment with rituximab-based chemotherapy, were associated with a more favorable outcome, but a low International Prognostic Index score and DLBCL morphology were independent predictors of overall survival. A comprehensive cytogenetic analysis of BCL2 and MYC status on all aggressive lymphomas may identify a group of high-risk patients who may benefit from chemotherapeutic regimens that include rituximab and/or BCL2-targeted therapy.
Alignment of Polysaccharide–SWNT Composites by Metal–Ligand Interactions
Authors: Tsuchiya Youichi , Haraguchi Shuichi , Sugikawa Kouta , Shiraki Tomohiro , Kaneko Kenji , Shinkai Seiji
Published: July 2009

The composite of terpyridine-modified polysaccharide (TPySPG) and single-walled carbon nanotube (SWNT) afforded sheet-like morphologies in the presence of ferric ion. On the basis of TEM images, it was proposed that the sheet-like morphologies are created by the metal–ligand interaction cross-linking TPySPG/SWNT components.
Selective Detection of Uric Acid in the Presence of Ascorbic Acid and Acetaminophen at a Glassy Carbon Paste Electrode in an Alkaline Solution
Authors: Inada Kazufumi , Nishiyama Katsuhiko , Taniguchi Isao
Published: July 2009

Selective determination of uric acid (UA) was conducted in the presence of ascorbic acid (AA) and acetaminophen (APAP) as interference species at an unmodified glassy carbon paste electrode (GCPE). Using the GCPE prepared in our lab, we succeeded in detecting UA in the presence of AA in acidic and alkaline media. In addition, the oxidation peak potential of APAP is very close to that of UA in neutral media, but in alkaline media, a peak separation of ca. 140 mV was obtained between UA and APAP on the differential pulse voltammogram (DPV).
Fabrication of Hollow Carbon Spheres with Porous Shells by Interfacial Sol–Gel Polymerization
Authors: Huang Miaofeng , Ju Xin , Wang Chaoyan , Tang Yongjian , Jiang Xiaoping
Published: July 2009

Hollow resorcinol–formaldehyde (RF) aerogel spheres were synthesized by interfacial polymerization of resorcinol and formaldehyde monomers with NaOH as a catalyst. Commercial hollow polystyrene spheres were used as catalyst storage materials and templates in the synthesis. Hollow carbon aerogel spheres were prepared by carbonization of the RF aerogel spheres at a high temperature under a nitrogen atmosphere. The processing procedures and the conditions of the structures of hollow carbon spheres were studied.
The Direct Synthesis of Hydrogen Peroxide (ca. 5 wt %) from Hydrogen and Oxygen by Microreactor Technology
Authors: Inoue Tomoya , Ohtaki Kenichiro , Kikutani Yoshikuni , Sato Koichi , Nishioka Masateru , Hamakawa Satoshi , Mawatari Kazuma , Mizukami Fujio , Kitamori Takehiko
Published: July 2009

5 wt % hydrogen peroxide was achieved by direct synthesis from hydrogen and oxygen at room temperature and 1.0 MPa, in a glass-fabricated microreactor designated for gas–liquid–solid reaction with ideal gas–liquid distribution to the catalyst packed bed.
Committed osteoclast precursors colonize the bone and improve the phenotype of a mouse model of autosomal recessive osteopetrosis
Authors: Cappariello Alfredo , Berardi Anna Concetta , Peruzzi Barbara , Del Fattore Andrea , Ugazio Alberto , Bottazzo Gian Franco , Teti Anna
Published: July 2009

Osteopetrosis is a genetic disease characterized by defective osteoclasts. Autosomal recessive osteopetrosis is fatal within the first years of life. Hematopoietic stem cell transplantation (HSCT) cures fewer than 50% of cases but often leaves severe neurologic damages and other dysfunctions. Osteoclast appearance after HSCT is a slow process, during which disease progression continues. We hypothesize that a support osteoclast precursor therapy may contribute to improve the osteopetrotic phenotype. To this end, we established a procedure to obtain the best yield of osteoclast precursors from human peripheral blood or mouse bone marrow mononuclear cells. These cells were injected in vivo in animal models, testing different cell injection protocols, as well as in association with CD117+ stem cells. Injected cells showed the ability to form multinucleated osteoclasts and to improve the phenotype of oc/oc osteopetrotic mice. In the best working protocol, animals presented with longer survival, improved weight and longitudinal growth, increased tibial length, tooth eruption, decreased bone volume, reduced bone marrow fibrosis, and improved hematopoiesis compared with sham-treated mice. These results provide first-hand information on the feasibility of a support osteoclast precursor therapy in osteopetrosis. © 2010 American Society for Bone and Mineral Research
Overexpression of secreted frizzled-related protein 1 inhibits bone formation and attenuates parathyroid hormone bone anabolic effects
Authors: Yao Wei , Cheng Zhiqiang , Shahnazari Mohammad , Dai Wewei , Johnson Mark L , Lane Nancy E
Published: July 2009

Secreted frizzled-related protein 1 (sFRP1) is an antagonist of Wnt signaling, an important pathway in maintaining bone homeostasis. In this study we evaluated the skeletal phenotype of mice overexpressing sFRP1 (sFRP1 Tg) and the interaction of parathyroid hormone (PTH) treatment and sFRP1 (over)expression. Bone mass and microarchitecture were measured by micro-computed tomography (µCT). Osteoblastic and osteoclastic cell maturation and function were assessed in primary bone marrow cell cultures. Bone turnover was assessed by biochemical markers and dynamic bone histomorphometry. Real-time PCR was used to monitor the expression of several genes that regulate osteoblast maturation and function in whole bone. We found that trabecular bone mass measurements in distal femurs and lumbar vertebral bodies were 22% and 51% lower in female and 9% and 33% lower in male sFRP1 Tg mice, respectively, compared with wild-type (WT) controls at 3 months of age. Genes associated with osteoblast maturation and function, serum bone formation markers, and surface based bone formation were significantly decreased in sFRP1 Tg mice of both sexes. Bone resorption was similar between sFRP1 Tg and WT females and was higher in sFRP1 Tg male mice. Treatment with hPTH(1-34) (40 µg/kg/d) for 2 weeks increased trabecular bone volume in WT mice (females: +30% to 50%; males: +35% to 150%) compared with sFRP1 Tg mice (females: +5%; males: +18% to 54%). Percentage increases in bone formation also were lower in PTH-treated sFRP1 Tg mice compared with PTH-treated WT mice. In conclusion, overexpression of sFRP1 inhibited bone formation as well as attenuated PTH anabolic action on bone. The gender differences in the bone phenotype of the sFRP1 Tg animal warrants further investigation. © 2010 American Society for Bone and Mineral Research
Variable bone fragility associated with an Amish COL1A2 variant and a knock-in mouse model
Authors: Daley Ethan , Streeten Elizabeth A , Sorkin John D , Kuznetsova Natalia , Shapses Sue A , Carleton Stephanie M , Shuldiner Alan R , Marini Joan C , Phillips Charlotte L , Goldstein Steven A , Leikin Sergey , McBride Daniel J
Published: July 2009

Osteogenesis imperfecta (OI) is a heritable form of bone fragility typically associated with a dominant COL1A1 or COL1A2 mutation. Variable phenotype for OI patients with identical collagen mutations is well established, but phenotype variability is described using the qualitative Sillence classification. Patterning a new OI mouse model on a specific collagen mutation therefore has been hindered by the absence of an appropriate kindred with extensive quantitative phenotype data. We benefited from the large sibships of the Old Order Amish (OOA) to define a wide range of OI phenotypes in 64 individuals with the identical COL1A2 mutation. Stratification of carrier spine (L1–4) areal bone mineral density (aBMD) Z-scores demonstrated that 73% had moderate to severe disease (less than −2), 23% had mild disease (−1 to −2), and 4% were in the unaffected range (greater than −1). A line of knock-in mice was patterned on the OOA mutation. Bone phenotype was evaluated in four F1 lines of knock-in mice that each shared approximately 50% of their genetic background. Consistent with the human pedigree, these mice had reduced body mass, aBMD, and bone strength. Whole-bone fracture susceptibility was influenced by individual genomic factors that were reflected in size, shape, and possibly bone metabolic regulation. The results indicate that the G610C OI (Amish) knock-in mouse is a novel translational model to identify modifying genes that influence phenotype and for testing potential therapies for OI. © 2010 American Society for Bone and Mineral Research
Relation of serum serotonin levels to bone density and structural parameters in women
Authors: Mödder Ulrike I , Achenbach Sara J , Amin Shreyasee , Riggs B Lawrence , Melton L Joseph , Khosla Sundeep
Published: July 2009

Recent studies have demonstrated an important role for circulating serotonin in regulating bone mass in rodents. In addition, patients treated with selective serotonin reuptake inhibitors (SSRIs) have reduced areal bone mineral density (aBMD). However, the potential physiologic role of serotonin in regulating bone mass in humans remains unclear. Thus we measured serum serotonin levels in a population-based sample of 275 women and related these to total-body and spine aBMD assessed by dual-energy X-ray absorptiometry, femur neck total and trabecular volumetric BMD (vBMD) and vertebral trabecular vBMD assessed by quantitative computed tomography (QCT), and bone microstructural parameters at the distal radius assessed by high-resolution peripheral QCT (HRpQCT). Serotonin levels were inversely associated with body and spine aBMD (age-adjusted R = −0.17 and −0.16, P < .01, respectively) and with femur neck total and trabecular vBMD (age-adjusted R = −0.17 and −0.25, P < .01 and < .001, respectively) but not lumbar spine vBMD. Bone volume/tissue volume, trabecular number, and trabecular thickness at the radius were inversely associated with serotonin levels (age-adjusted R = −0.16, −0.16, and −0.14, P < .05, respectively). Serotonin levels also were inversely associated with body mass index (BMI; age-adjusted R = −0.23, P < .001). Multivariable models showed that serotonin levels remained significant negative predictors of femur neck total and trabecular vBMD, as well as trabecular thickness at the radius, after adjusting for age and BMI. Collectively, our data provide support for a physiologic role for circulating serotonin in regulating bone mass in humans. © 2010 American Society for Bone and Mineral Research
Bone mass and strength in older men with type 2 diabetes: The Osteoporotic Fractures in Men Study
Authors: Petit Moira A , Paudel Misti L , Taylor Brent C , Hughes Julie M , Strotmeyer Elsa S , Schwartz Ann V , Cauley Jane A , Zmuda Joseph M , Hoffman Andrew R , Ensrud Kristine E
Published: July 2009

The effects of type 2 diabetes mellitus (T2DM) on bone volumetric density, bone geometry, and estimates of bone strength are not well established. We used peripheral quantitative computed tomography (pQCT) to compare tibial and radial bone volumetric density (vBMD, mg/cm3), total (ToA, mm2) and cortical (CoA, mm2) bone area and estimates of bone compressive and bending strength in a subset (n = 1171) of men (≥65 years of age) who participated in the multisite Osteoporotic Fractures in Men (MrOS) study. Analysis of covariance–adjusted bone data for clinic site, age, and limb length (model 1) and further adjusted for body weight (model 2) were used to compare data between participants with (n = 190) and without (n = 981) T2DM. At both the distal tibia and radius, patients with T2DM had greater bone vBMD (+2% to +4%, model 1, p < .05) and a smaller bone area (ToA −1% to −4%, model 2, p < .05). The higher vBMD compensated for lower bone area, resulting in no differences in estimated compressive bone strength at the distal trabecular bone regions. At the mostly cortical bone midshaft sites of the radius and tibia, men with T2DM had lower ToA (−1% to −3%, p < .05), resulting in lower bone bending strength at both sites after adjusting for body weight (−2% to −5%, p < .05) despite the lack of difference in cortical vBMD at these sites. These data demonstrate that older men with T2DM have bone strength that is low relative to body weight at the cortical-rich midshaft of the radius despite no difference in cortical vBMD. © 2010 American Society for Bone and Mineral Research
Bone mineralization defects and vitamin D deficiency: Histomorphometric analysis of iliac crest bone biopsies and circulating 25-hydroxyvitamin D in 675 patients
Authors: Priemel Matthias , von Domarus Christoph , Klatte Till Orla , Kessler Steffen , Schlie Julia , Meier Simon , Proksch Nils , Pastor Frederic , Netter Clemens , Streichert Thomas , Püschel Klaus , Amling Michael
Published: July 2009

Parathyroid hormone (PTH) is only one measurable index of skeletal health, and we reasoned that a histomorphometric analysis of iliac crest biopsies would be another and even more direct approach to assess bone health and address the required minimum 25-Hydroxyvitamin D [25(OH)D] level. A cohort from the northern European population with its known high prevalence of vitamin D deficiency therefore would be ideal to answer the latter question. We examined 675 iliac crest biopsies from male and female individuals, excluding all patients who showed any signs of secondary bone diseases at autopsy. Structural histomorphometric parameters, including osteoid indices, were quantified using the Osteomeasure System according to ASBMR standards, and serum 25(OH)D levels were measured for all patients. Statistical analysis was performed by Student's t test. The histologic results demonstrate an unexpected high prevalence of mineralization defects, that is, a pathologic increase in osteoid. Indeed, 36.15% of the analyzed patients presented with an osteoid surface per bone surface (OS/BS) of more than 20%. Based on the most conservative threshold that defines osteomalacia at the histomorphometric level with a pathologic increase in osteoid volume per bone volume (OV/BV) greater than 2% manifest mineralization defects were present in 25.63% of the patients. The latter were found independent of bone volume per trabecular volume (BV/TV) throughout all ages and affected both sexes equally. While we could not establish a minimum 25(OH)D level that was inevitably associated with mineralization defects, we did not find pathologic accumulation of osteoid in any patient with circulating 25(OH)D above 75 nmol/L. Our data demonstrate that pathologic mineralization defects of bone occur in patients with a serum 25(OH)D below 75 nmol/L and strongly argue that in conjunction with a sufficient calcium intake, the dose of vitamin D supplementation should ensure that circulating levels of 25(OH)D reach this minimum threshold (75 nmol/L or 30 ng/mL) to maintain skeletal health. © 2010 American Society for Bone and Mineral Research
Parathyroid hormone (PTH)–induced bone gain is blunted in SOST overexpressing and deficient mice
Authors: Kramer Ina , Loots Gabriela G , Studer Anne , Keller Hansjoerg , Kneissel Michaela
Published: July 2009

Intermittent parathyroid hormone (PTH) treatment is a potent bone anabolic principle that suppresses expression of the bone formation inhibitor Sost. We addressed the relevance of Sost suppression for PTH-induced bone anabolism in vivo using mice with altered Sost gene dosage. Six-month-old Sost overexpressing and 2-month-old Sost deficient male mice and their wild-type littermates were subjected to daily injections of 100 µg/kg PTH(1–34) or vehicle for a 2-month period. A follow-up study was performed in Sost deficient mice using 40 and 80 µg/kg PTH(1–34). Animals were sacrificed 4 hours after the final PTH administration and Sost expression in long bone diaphyses was determined by qPCR. Bone changes were analyzed in vivo in the distal femur metaphysis by pQCT and ex vivo in the tibia and lumbar spine by DXA. Detailed ex vivo analyses of the femur were performed by pQCT, µCT, and histomorphometry. Overexpression of Sost resulted in osteopenia and Sost deletion in high bone mass. As shown before, PTH suppressed Sost in wild-type mice. PTH treatment induced substantial increases in bone mineral density, content, and cortical thickness and in aging wild-type mice also led to cancellous bone gain owing to amplified bone formation rates. PTH-induced bone gain was blunted at all doses and skeletal sites in Sost overexpressing and deficient mice owing to attenuated bone formation rates, whereas bone resorption was not different from that in PTH-treated wild-type controls. These data suggest that suppression of the bone formation inhibitor Sost by intermittent PTH treatment contributes to PTH bone anabolism. © 2010 American Society for Bone and Mineral Research