bluuebunny/crossref_metadata_2025 huggingface dataset:
Qualitative Application of COBAS AMPLICOR HCV Test Version 2.0 Assays in Patients with Chronic Hepatitis C Virus Infection and Comparison of Clinical Performance with Version 1.0
Authors: Hsieh Ming‐Yen , Lee Li‐Po , Hou Nai‐Jen , Yang Jeng‐Fu , Huang Jee‐Fu , Dai Chia‐Yen , Chuang Wan‐Long , Lin Zu‐Yau , Chen Shinn‐Cherng , Hsieh Ming‐Yuh , Wang Liang‐Yen , Chang Wen‐Yu , Yu Ming‐Lung
Published: July 2009

The objective of this research was to investigate the clinical performance of COBAS AMPLICOR hepatitis C virus (HCV) test version 2.0 Assays (CA V2.0). Eight serial samples with standard HCV ribonucleic acid (RNA) concentration and 10 times serial dilution of the 500 IU/mL samples were tested in triplicate by CA V2.0 (the limit of detection was 50 IU/mL). HCV RNA was investigated with CA V2.0 in 220 specimens from 100 chronic hepatitis C (CHC) patients, 60 chronic hepatitis B patients, and 60 healthy blood donors. The sensitivity was 99% and the specificity was 98.3%. Sera of 84 naïve CHC patients receiving standard interferon plus ribavirin for 24 weeks were tested by CA V2.0 and CA V1.0 at weeks 2, 4 and 8. The positive detection rates of CA V2.0 were significantly higher than CA V1.0 at week 2 (60.7% vs. 51.2%; p < 0.01) and week 8 (27.4% vs. 21.4%; p < 0.05). At weeks 2, 4 and 8, the positive predictive values were 90.91%, 83.02% and 78.69% with CA V2.0, and 90.24%, 82.14% and 72.73% with CA V1.0. The negative predictive values were 58.82%, 77.42% and 86.96% with CA V2.0, and 67.44%, 82.14% and 83.33% with CA V1.0. However, there was no significant difference between CA V2.0 and CA V1.0 for predicting sustained virologic response.
Continuous Arteriovenous Hemodialysis and Continuous Venovenous Hemofiltration in Burn Patients with Acute Renal Failure
Authors: Sun I‐Feng , Lee Su‐Shin , Lin Sin‐Daw , Lai Chung‐Sheng
Published: July 2009

Acute renal failure (ARF) is a very common condition that may occur in patients with major burn injuries. The majority of burn patients with ARF have a high mortality rate, ranging from 73% to 100%. There are several ways to treat ARF in burn patients, including peritoneal dialysis (PD), intermittent hemodialysis, and continuous renal replacement therapy (CRRT). CRRT is generally used in patients in whom intermittent hemodialysis has failed to control hypovolemia, as well as in patients who cannot tolerate intermittent hemodialysis. Additionally, PD is not suitable for patients with burns within the abdominal area. For these reasons, most patients with unstable hemodynamic conditions receive CRRT. In this study (conducted in our burn unit between 1997 and 2004), six burn patients received CRRT: three received continuous arteriovenous hemodialysis (CAVHD) and the other three received continuous venovenous hemofiltration (CVVH). The patients were all males, with a mean age of 49.8 years (range, 27–80 years), and a mean burnt surface area of 65.1% (range, 30–95%). Four patients died due to multiple organ failure, and two patients recovered from severe ARF. CRRT has been proven safe and useful for burn patients with ARF. According to this study, we conclude that CVVH is an appropriate tool for treating ARF, with a lower incidence of vascular complications than CAVHD.
Artificial Dermis Graft on the Mandible Lacking Periosteum After Excision of an Ossifying Fibroma: A Case Report
Authors: Chen Chun‐Ming , Shen Yee‐Shyong , Yang Chia‐Fu , Shieh Tien‐Yu , Chen Chung‐Ho , Huang I‐Yueh
Published: July 2009

Collagen‐based grafts have often been used as artificial tissue substitutes for the repair of tissue and organ defects. It is common surgical knowledge that autogenous or artificial skin grafts take well on the intact periosteum of bone. However, many experienced surgeons indicate that auto‐genous or artificial skin grafts subsist poorly on the bone surface without periosteum. Therefore, primary closure is usually recommended in the wound healing of exposed bone. Vestibuloplasty might be needed to create enough depth of vestibule in the future. In this case report, we describe a peripheral ossifying fibroma surgically excised leaving a bony defect, which was covered by a piece of artificial dermis. Satisfactory result of the repaired surgical defect showed no need of vestibuloplasty after 6 years of follow‐up.
Carbon isotope fluctuations of terrestrial organic matter for the Upper Cretaceous (Cenomanian–Santonian) in the Obira area of Hokkaido, Japan
Authors: URAMOTO GO-ICHIRO , ABE YOSHIHIRO , HIRANO HIROMICHI
Published: July 2009

Stratigraphic fluctuations of carbon isotope values of terrestrial organic matter within the Upper Cretaceous (Cenomanian–Santonian) sequence in the Obira area of Hokkaido, Japan, record distinctive δ13C fluctuations for the Cenomanian–Turonian boundary, the Middle Turonian, the upper Turonian–lower Coniacian, and the Santonian. A biostratigraphic framework of the age-diagnostic taxa (ammonoids, bivalves and planktic foraminifers) indicates that these δ13C fluctuation events are comparable with those recorded in δ13C data of terrestrial organic matter in Japan and marine carbonates in Europe. These correlations reinforce the utility of these δ13C events in terms of global chemostratigraphy. In particular, the δ13C patterns within the overall positive interval of the Cenomanian–Turonian boundary event are highly conformable between marine and terrestrial records. The consistent nature of these different records of δ13C fluctuation patterns demonstrates that the terrestrial organic δ13C data mirror the global-scale δ13C patterns in the carbon reservoir of ocean–atmosphere–terrestrial biosphere during the Cenomanian–Turonian boundary event. In addition, global correlation of short-term marine and terrestrial organic δ13C fluctuations of the Upper Cretaceous sequence indicate that the magnitude of several terrestrial organic δ13C events appears more amplified than that of coeval marine carbonate δ13C events. This correlation is interpreted to mean that the effects of local CO2 emission into the atmosphere by release of terrestrial methane hydrate or biomass burning of terrestrial vegetation in the hinterland of the NE Asian region have been superimposed on the global δ13C trend and resulted in the terrestrial organic δ13C records of the Yezo Group.
A fistful of shells: amplifying sclerochronological and palaeoclimate signals from molluscan death assemblages
Authors: HELAMA S. , NIELSEN J. K. , MACIAS FAURIA M. , VALOVIRTA I.
Published: July 2009

A growing body of literature is using sclerochronological information to infer past climates. Sclerochronologies are based on series of skeletal growth records of molluscs that have been correctly aligned in time. Incremental series are obtained from a number of shells to assess the temporal control and improve the climate signal in the final chronology. Much of the sclerochronological theory has been adopted from tree-ring science, due to the longer tradition and more firmly established concepts of chronology construction in dendrochronology. Compared to tree-ring studies, however, sclerochronological datasets are often characterized by relatively small sample size. Here we evaluate how effectively palaeoclimatic signal can be extracted from such a suite of samples. In so doing, the influences of the very basic methods that are applied in nearly every sclerochronological study to remove the non-climatic growth variability prior to palaeoclimatic interpretations, are ranked by their capability to amplify the desired signal. The study is performed in the context of six shells that constitute a bicentennial growth record from annual shell increments of freshwater pearl mussel. It was shown that when the individual series were detrended using the models set by the mean or the median summary curves for ageing (that is, applying Regional Curve Standardization, RCS), instead of fitting the ageing mode statistically to each series, the resulting sclerochronology displayed more low-frequency variability. Consistently, the added low-frequency variability evoked higher proxy–climate correlations. These results show the particular benefit of using the RCS method to develop sclerochronologies and preserve their low-frequency variations. Moreover, calculating the ageing curve and the final chronology by median, instead of mean, resulted in an amplified low-frequency climate signal. The results help to answer a growing need to better understand the behaviour of the sclerochronological data. In addition, we discuss the pitfalls that may potentially disrupt palaeoclimate signal detection in similar sclerochronological studies. Pitfalls may arise from shell taphonomy, water chemistry, time-variant characters of biological growth trends and small sample size.
Fluids in coesite-bearing rocks of the Tso Morari Complex, NW Himalaya: evidence for entrapment during peak metamorphism and subsequent uplift
Authors: MUKHERJEE BARUN K. , SACHAN HIMANSHU K.
Published: July 2009

Fluid inclusions trapped in coesite-bearing rocks provide important information on the fluid phases present during ultrahigh-pressure metamorphism. The subduction-related coesite-bearing eclogites of the Tso Morari Complex, Himalaya, contain five major types of fluids identified by microthermometry and Raman spectroscopy. These are: (1) high-salinity brine, (2) N2, (3) CH4, (4) CO2and (5) low-salinity aqueous fluids. These fluids were trapped during both deep subduction and exhumation processes. The coesite-bearing rocks are inferred to have been buried to a depth of >120 km, where they experienced ultrahigh-pressure metamorphism. The fluid–rock interaction provides direct evidence for fluid derivation during a deep subduction process as demonstrated by silica–carbonate assemblages in eclogite. High salinity brine, N2and CH4inclusions are remnants of prograde and peak metamorphic fluids, whereas CO2and low-salinity aqueous fluids appear to have been trapped late, during uplift. The high-salinity brine was possibly derived from subducted ancient metasedimentary rocks, whereas the N2and CH4fluids were likely generated through chemical breakdown of NH3-bearing K minerals and graphite. Alternatively, CH4might have been formed by a mixed fluid that was released from calcareous sediments during subduction or supplied through subducted oceanic metabasic rocks. High density CO2is associated with matrix minerals formed during granulite-facies overprinting of the ultrahigh-pressure eclogite. During retrogression to amphibolite-facies conditions, low-salinity fluids were introduced from external sources, probably the enclosing gneisses. This source enhances salinity differences as compared to primary saline inclusions. The subducting Indian lithosphere produced brines prior to achieving maximal depths of >120 km, where fluids were instead dominated by gaseous phases. Subsequently, the Indian lithosphere released CO2-rich fluids during fast exhumation and was then infiltrated by the low-salinity aqueous fluids near the surface through external sources. Elemental modelling may improve quantitative understanding of the complexity of fluids and their reactions.
The Diffusion of Revolution: ‘1848’ in Europe and Latin America
Authors: Weyland Kurt
Published: July 2009

What accounts for the spread of political protest and contention across countries? Analyzing the wildfire of attempted revolutions in 1848, the present article assesses four causal mechanisms for explaining diffusion, namely external pressure from a great power (such as revolutionary France after 1789); the promotion of new norms and values—such as liberalism and democracy—by more advanced countries; rational learning from successful contention in other nations; or boundedly rational, potentially distorted inferences from select foreign experiences. The patterns in which revolutionary contention spread and eyewitness reports from all sides of the ensuing conflicts suggest that bounded rationality played a crucial role: cognitive heuristics that deviate from fully rational procedures drew attention to some experiences but not others and induced both challengers and defenders of the established order to draw rash conclusions from these experiences, particularly the French monarchy's fall in February 1848. My study also shows, however, that other factors made important contributions, for instance by preparing the ground for the wave of regime contention.
Network Analysis for International Relations
Authors: Hafner-Burton Emilie M. , Kahler Miles , Montgomery Alexander H.
Published: July 2009

International relations research has regarded networks as a particular mode of organization, distinguished from markets or state hierarchies. In contrast, network analysis permits the investigation and measurement of network structures—emergent properties of persistent patterns of relations among agents that can define, enable, and constrain those agents. Network analysis offers both a toolkit for identifying and measuring the structural properties of networks and a set of theories, typically drawn from contexts outside international relations, that relate structures to outcomes. Network analysis challenges conventional views of power in international relations by defining network power in three different ways: access, brokerage, and exit options. Two issues are particularly important to international relations: the ability of actors to increase their power by enhancing and exploiting their network positions, and the fungibility of network power. The value of network analysis in international relations has been demonstrated in precise description of international networks, investigation of network effects on key international outcomes, testing of existing network theory in the context of international relations, and development of new sources of data. Partial or faulty incorporation of network analysis, however, risks trivial conclusions, unproven assertions, and measures without meaning. A three-part agenda is proposed for future application of network analysis to international relations: import the toolkit to deepen research on international networks; test existing network theories in the domain of international relations; and test international relations theories using the tools of network analysis.
Dynamics and waves near multiple magnetic null points in reconnection diffusion region
Authors: Deng X. H. , Zhou M. , Li S. Y. , Baumjohann W. , Andre M. , Cornilleau N. , Santolík O. , Pontin D. I. , Reme H. , Lucek E. , Fazakerley A. N. , Decreau P. , Daly P. , Nakamura R. , Tang R. X. , Hu Y. H. , Pang Y. , Büchner J. , Zhao H. , Vaivads A. , Pickett J. S. , Ng C. S. , Lin X. , Fu S. , Yuan Z. G. , Su Z. W. , Wang J. F.
Published: July 2009

Identifying the magnetic structure in the region where the magnetic field lines break and how reconnection happens is crucial to improving our understanding of three‐dimensional reconnection. Here we show the in situ observation of magnetic null structures in the diffusion region, the dynamics, and the associated waves. Possible spiral null pair has been identified near the diffusion region. There is a close relation among the null points, the bipolar signature of the Z component of the magnetic field, and enhancement of the flux of energetic electrons up to 100 keV. Near the null structures, whistler‐mode waves were identified by both the polarity and the power law of the spectrum of electric and magnetic fields. It is found that the angle between the fans of the nulls is quite close to the theoretically estimated maximum value of the group‐velocity cone angle for the whistler wave regime of reconnection.
Profiles of ocean surface heating (POSH): A new model of upper ocean diurnal warming
Authors: Gentemann Chelle L. , Minnett Peter J. , Ward Brian
Published: July 2009

Shipboard radiometric measurements of diurnal warming at the ocean surface and profiles through the diurnal thermocline were utilized to assess the temporal and vertical variability and to develop a new physics‐based model of near‐surface warming. The measurements and modeled diurnal warming were compared, with the goal of comprehensively evaluating differences between the data and model results. On the basis of these results, the diurnal model was refined while attempting to maintain agreement with the measurements. Simplified bulk models commonly do not provide information on the vertical structure within the warm layer, but this new model predicts the vertical temperature profile within the diurnal thermocline using an empirically derived function dependent on wind speed. The vertical profile of temperature provides both a straightforward methodology for modeling differences due to diurnal warming between measurements made at different depths (e.g., in situ measurements at various depths and measurements of the surface temperatures by satellite radiometers) and information on upper ocean thermal structure. Additionally, the model estimates of diurnal warming at the ocean surface are important for air‐sea heat and gas flux calculations, blending satellite sea surface temperature fields, and air‐sea interaction studies.
Does the Columbia River plume influence phytoplankton community structure along the Washington and Oregon coasts?
Authors: Frame Elizabeth R. , Lessard Evelyn J.
Published: July 2009

As part of the River Influences on Shelf Ecosystems (RISE) program, we examined the influence of the Columbia River plume on the composition and biomass of phytoplankton communities on the Washington and Oregon coasts. We determined the taxonomic composition, size structure, and biomass of phytoplankton assemblages in near‐surface shelf waters during four 3‐week cruises in spring and/or summer of 2004–2006. As the Columbia plume is very dynamic, the influence of the plume was examined in three ways. Two comparisons of the entire data set were made: (1) a geographical comparison of the Washington, Oregon, and Columbia River mouth regions based on latitude and (2) a “plume” versus “nonplume” comparison based on salinity. A third comparison focused on samples taken in and outside of three specific plumes under different upwelling/downwelling conditions. In whole data set comparisons, there were no significant differences in chlorophyll, carbon biomass, or diatom community structure between regions or between plume and nonplume samples. However, within some cruises there were regional and plume differences in chlorophyll and biomass. Diatom community composition differed between cruises, but within a cruise it was similar across regions and in plume/nonplume samples, indicating there was no unique plume community. On finer time and space scales, differences in community structure as well as biomass were evident between samples in and outside of specific plumes. Over broader scales, the Columbia plume acts to make coastal phytoplankton communities more homogeneous. Specific impacts will depend on the history of upwelling and nutrient status of the coastal waters which the plume encounters.
A remote effect of geothermal heat on the global thermohaline circulation
Authors: Urakawa L. Shogo , Hasumi Hiroyasu
Published: July 2009

The effect of the geothermal heat on the global thermohaline circulation (THC) is numerically investigated with an ocean general circulation model (OGCM) under a realistic configuration. It is known that the geothermal heat strongly intensifies meridional overturning circulations (MOCs). Although earlier studies show that the geothermal heat can produce a significant amount of gravitational potential energy (GPE), it is left to be clarified how the geothermal heat affects the intensity of MOCs in terms of energetics. This study shows that the geothermal heat in the Indo‐Pacific has a remote effect on the Atlantic MOC while that in the Atlantic does not contribute to the intensity of MOC in the Indo‐Pacific. This remote effect can be accounted for as a result of an interbasin transport of GPE and its energy conversion to kinetic energy (KE) that compensates additional viscous dissipation associated with the MOC enhancement. The asymmetric response of MOCs to the geothermal heat can be explained by the circulation pattern.
Numerical simulations of Asian dust storms using a coupled climate‐aerosol microphysical model
Authors: Su Lin , Toon Owen B.
Published: July 2009

We have developed a three‐dimensional coupled microphysical/climate model based on the National Center for Atmospheric Research Community Atmospheres Model and the University of Colorado/NASA Community Aerosol and Radiation Model for Atmospheres. We have used the model to investigate the sources, removal processes, transport, and optical properties of Asian dust aerosol and its impact on downwind regions. The model simulations are conducted primarily during the time frame of the Aerosol Characterization Experiment–Asia field experiment (March–May 2001) since considerable in situ data are available at that time. Our dust source function follows Ginoux et al. (2001). We modified the dust source function by using the friction velocity instead of the 10‐m wind based on wind erosion theory, by adding a size‐dependent threshold friction velocity following Marticorena and Bergametti (1995) and by adding a soil moisture correction. A Weibull distribution is implemented to estimate the subgrid‐scale wind speed variability. We use eight size bins for mineral dust ranging from 0.1 to 10 μm radius. Generally, the model reproduced the aerosol optical depth retrieved by the ground‐based Aerosol Robotic Network (AERONET) Sun photometers at six study sites ranging in location from near the Asian dust sources to the Eastern Pacific region. By constraining the dust complex refractive index from AERONET retrievals near the dust source, we also find the single‐scattering albedo to be consistent with AERONET retrievals. However, large regional variations are observed due to local pollution. The timing of dust events is comparable to the National Institute for Environmental Studies (NIES) lidar data in Beijing and Nagasaki. However, the simulated dust aerosols are at higher altitudes than those observed by the NIES lidar.
Observations of speciated atmospheric mercury at three sites in Nevada: Evidence for a free tropospheric source of reactive gaseous mercury
Authors: Weiss‐Penzias Peter , Gustin Mae Sexauer , Lyman Seth N.
Published: July 2009

Air mercury (Hg) speciation was measured for 11 weeks (June–August 2007) at three sites simultaneously in Nevada, USA. Mean reactive gaseous Hg (RGM) concentrations were elevated at all sites relative to those reported for locations not directly influenced by known point sources. RGM concentrations at all sites displayed a regular diel pattern and were positively correlated with ozone (O3) and negatively correlated with elemental Hg (Hg0) and dew point temperature (Tdp). Superimposed on the diel changes were 2‐ to 7‐day periods when RGM concentrations increased across all three sites, producing significant intersite correlations of RGM daily means (r = 0.53–0.76, p < 0.0001). During these periods, enhanced O3 concentrations and lower Tdp were also observed. Back trajectories were applied to develop gridded frequency distribution (GFD) plots and determine trajectory residence times (TRT) in specific source boxes. The GFD for the upper‐quartile RGM daily means at one site showed a contributing airflow regime from the high‐altitude subtropics with little precipitation, while that developed for the lower‐quartile RGM concentrations indicated predominantly lower‐altitude westerly flow and precipitation. Daily mean TRT in a subtropical high‐altitude source box (>2 km and <35°N) explained a component of the daily mean RGM at two sites (r2 = 0.37 and 0.27, p < 0.05). These observations indicate that long‐range transport of RGM from the free troposphere is a potentially important component of Hg input to rural areas of the western United States.
Influence of lower stratospheric ozone variation on tropospheric temperature and mean meridional circulation in the Northern Hemisphere summer
Authors: Nakamura Tetsu , Akiyoshi Hideharu , Yamashita Yousuke
Published: July 2009

Through statistical analyses of observational data, the study examined the influence of the lower stratospheric ozone variation on the troposphere in the Northern Hemisphere mid‐latitude summer. It was found that an increase in the lower stratospheric ozone strengthens static stability at the tropopause. Thus, the vertical wave propagation is trapped there more efficiently. The zonal flow deceleration due to the wave forcing induces anomalous residual mean circulation. This causes anomalous cooling in the troposphere through anomalous upward motion to the south of 60°N and less latent heating to the north. As a result, the tropospheric temperature decreases vis‐à‐vis the increase in stratospheric ozone. A sensitivity experiment was carried out using an AGCM to examine the tropospheric responses to the increase in stratospheric ozone. The result shows responses similar to the observations. The consistence between the observation and AGCM suggests a climate change in the troposphere induced by stratospheric ozone variation.
Positive identification of lake strandlines in Shalbatana Vallis, Mars
Authors: Di Achille Gaetano , Hynek Brian M. , Searls Mindi L.
Published: July 2009

Remote sensing studies of possible Martian paleolakes have hinted at the presence of paleoshorelines on Mars, although have never been unequivocally identified. Recently‐acquired sub‐meter scale High Resolution Imaging Science Experiment (HiRISE) images of Shalbatana Vallis reveal the first direct evidence of strandlines along a delta formed within an intravalley lake during the Hesperian epoch (3.4 Ga). HiRISE images show where water from a 57‐km‐long valley built a delta, flowed over its subaerial plain, and finally debouched into a more than 450‐m‐deep lake, forming chutes in the subaqueous part of the deposit. At present, the studied system contains some of the most pristine, distinctive, and recent lacustrine evidence among all the candidate Martian paleolakes. The associated sedimentary deposits provide a valuable target for future in‐situ analyses aimed at the characterization of the hydrology, climate, and biological potential of ancient Mars.
Long‐range southeastward transport of Asian biosmoke pollution: Signature detected by aerosol potassium in Northern Taiwan
Authors: Hsu Shih‐Chieh , Liu Shaw Chen , Huang Yi‐Tang , Chou Charles C. K. , Lung S. C. Candice , Liu Tsun‐Hsien , Tu Jien‐Yi , Tsai Fujung
Published: July 2009

Total potassium was determined in aerosol particles between 2002 and early 2007 in northern Taiwan (25°02′N, 121°31′E). Biosmoke potassium (non‐sea‐salt/noncrustal) was assessed and used as a tracer of biosmoke pollution, which essentially represents the combination of coal and biofuel combustion and biomass burning. PM10‐associated potassium displays a typical seasonality, peaking during the winter and waning during the summer. The size distribution showed a bimodal pattern, peaking at a supermicron size (2.5–5.6 μm) and at around 1 μm, demonstrating multiple sources. Size distribution patterns revealed an evident seasonality, indicative of the different domination of natural and biosmoke sources in the two main periods of the northeasterly and summer monsoons, respectively. The relative contributions of biosmoke and natural sources to the total potassium were estimated to be 50–75% and 25–50%, respectively; the seasonality of biosmoke potassium is similar to that of total potassium. Substantial correlations existed between biosmoke potassium and selected trace metals (As, Se, Pb, and Mn), suggesting that the latter are essentially associated with biosmoke pollution. Another significant finding is that the seasonal mean concentrations of aerosol potassium between 2002 and early 2007 tend to increase. This could primarily be attributed to the increased consumption of coal in China, posing an urgent issue relevant to pollution mitigation in China. The southward inflow flux of biosmoke potassium to the south of 25°N during the northeasterly monsoon months has been estimated to be 56–79 mg m−2 d−1, which could be applied to the assessment of other biosmoke‐related species.
Increased Cerebral Blood Volume and Oxygen Consumption in Neonatal Brain Injury
Authors: Grant P Ellen , Roche-Labarbe Nadege , Surova Andrea , Themelis George , Selb Juliette , Warren Elizabeth K , Krishnamoorthy Kalpathy S , Boas David A , Franceschini Maria Angela
Published: July 2009

With the increasing interest in treatments for neonatal brain injury, bedside methods for detecting and assessing injury status and evolution are needed. We aimed to determine whether cerebral tissue oxygenation (StO2), cerebral blood volume (CBV), and estimates of relative cerebral oxygen consumption (rCMRO2) determined by bedside frequency-domain near-infrared spectroscopy (FD-NIRS) have the potential to distinguish neonates with brain injury from those with non-brain issues and healthy controls. We recruited 43 neonates ≤15 days old and >33 weeks gestational age (GA): 14 with imaging evidence of brain injury, 29 without suspicion of brain injury (4 unstable, 6 stable, and 19 healthy). A multivariate analysis of variance with Newman–Keuls post hoc comparisons confirmed group similarity for GA and age at measurement. StO2 was significantly higher in brain injured compared with unstable neonates, but not statistically different from stable or healthy neonates. Brain-injured neonates were distinguished from all others by significant increases in CBV and rCMRO2. In conclusion, although NIRS measures of StO2 alone may be insensitive to evolving brain injury, increased CBV and rCMRO2 seem to be useful for detecting neonatal brain injury and suggest increased neuronal activity and metabolism occurs acutely in evolving brain injury.
Total Cerebral Blood Flow and Hippocampal Volume in Patients with Arterial Disease. the SMART-MR Study
Authors: Knoops Arnoud Jan Gilbert , van der Graaf Yolanda , Appelman Auke Peter Adriaan , Mali Willem Petrus Theodorus Maria , Geerlings Mirjam Irene
Published: July 2009

It has been suggested that compared with other brain tissues, the hippocampus in particular is vulnerable to chronic hypoperfusion. We investigated whether total parenchymal cerebral blood flow (pCBF) was associated with hippocampal atrophy, and also whether this relationship was modified by white matter lesions (WMLs). In a cross-sectional analysis within the SMART-MR (Second Manifestations of ARTerial disease-magnetic resonance) study, which is a cohort study among patients with arterial disease, total CBF (tCBF) and hippocampal volume were assessed in 392 patients (mean age: 62±9 years, 84% men). Total CBF was expressed in per 100 mL brain volume for obtaining pCBF. Manual volumetric measurements of the hippocampus were carried out on a three-dimensional fast field-echo T1-weighted magnetic resonance imaging scan with isotropic voxels. Automated brain segmentation was used to quantify volumes of the WML and the total brain. A linear regression analysis showed that reduced pCBF was not associated with smaller hippocampal volume after adjustments were made for age and sex. The association attenuated further after additional adjustments were made for vascular risk factors, lacunar infarcts, and WMLs ( β=0.01 mL per s.d. decrease in pCBF; 95% confidence interval: −0.06 to 0.08). The association was not modified by WML ( P-value for interaction term pCBF∗WML=0.84). We found no evidence of the fact that lower parenchymal blood flow contributes to the neurodegeneration of the hippocampus in a population of patients with arterial disease.
Phosphatidylserine-Containing Liposomes Promote Maximal Survival of Retinal Neurons after Ischemic Injury
Authors: Dvoriantchikova Galina , Agudelo Christian , Hernandez Eleut , Shestopalov Valery I , Ivanov Dmitry
Published: July 2009

We investigated the systemic effect of liposomes bearing apoptotic signals on the level of inflammation and neuronal death induced by ischemia–reperfusion (IR). Using a model of retinal ischemia, we showed that treatment with phosphatidylserine (PS) and phosphatidylcholine (PC) liposomes significantly reduced the expression of proinflammatory genes, including that of Il1b, Il6, Ccl2, Ccl5, Cxcl10, and Icam1, 24 h after reperfusion. Phosphatidylserine liposome treatment was the most efficient and correlated with significantly reduced neuronal death in the retina 7 days after reperfusion. The results of our study indicate that therapeutic strategy based on mimicking a systemic increase in apoptotic signaling can significantly reduce central nervous system damage induced by IR and improve neurologic outcome.
Neuroprotective Role of Lactate after Cerebral Ischemia
Authors: Berthet Carole , Lei Hongxia , Thevenet Jonathan , Gruetter Rolf , Magistretti Pierre J , Hirt Lorenz
Published: July 2009

It is well established that lactate can be used as an energy substrate by the brain by conversion to pyruvate and a subsequent oxidation in the mitochondria. Knowing the need for readily metabolizable substrates directly after ischemia and the protective effect of lactate after excitotoxicity, the aim of this study was to investigate whether lactate administration directly after ischemia could be neuroprotective. In vitro, the addition of 4 mmol/L l-lactate to the medium of rat organotypic hippocampal slices, directly after oxygen and glucose deprivation (OGD), protected against neuronal death, whereas a higher dose of 20 mmol/L was toxic. In vivo, after middle cerebral artery occlusion in the mouse, an intracerebroventricular injection of 2 μL of 100 mmol/L l-lactate, immediately after reperfusion, led to a significant decrease in lesion size, which was more pronounced in the striatum, and an improvement in neurologic outcome. A later injection 1 h after reperfusion did not reduce lesion size, but significantly improved neurologic outcome, which is an important point in the context of a potential clinical application. Therefore, a moderate increase in lactate after ischemia may be a therapeutic tool.
Effects of Environmental Props on Communication in Aphasia Group Therapy
Authors: Pimentel Jane , Algeo Dana
Published: July 2009

Group treatment is a viable intervention for adults with a variety of acquired neuropathologies. Using groups for intervention has been best established with persons with aphasia and allows for a focus on activity limitations and participation restrictions (World Health Organization [WHO], 2001). Wertz et al. (1981) showed that group therapy was at least as good as individual treatment and Elman and Bernstein-Ellis some years later demonstrated the efficacy of aphasia group therapy (1999a). This group therapy has been described as a communication halfway house, providing a safe place to produce less than perfect speech and practice compensatory strategies to communicate in a meaningful way (Helm-Estabrooks & Albert, 2004). Meaningful language goes beyond expressing wants and needs and addresses the social component to language (Light, 1988). The National Aphasia Association aptly describes this social focus of language saying that “the reach of aphasia seldom ends within the domain of language, as our ability to communicate shapes our perception of self and our ability to interact with friends and loved ones” (NAA, 2002). Elman and Bernstein-Ellis also demonstrated this psychosocial benefit of aphasia group therapy (1999b).
Intervention Strategies for the Staged Individual With Dementia
Authors: Voyzey George A.
Published: July 2009

There are 24 million individuals living with some form of dementia in the world today. In our lifetime, this number will continue to rise as health care and medicine permit the population to live longer. More nursing facilities will be needed to accommodate the increase in the geriatric population and with this surge will come an increase in the number of patients with some form of dementia. Speech-language pathologists must be prepared to assess and treat these patients demonstrating behaviors across the full spectrum of dementia. This article will familiarize clinicians with the Global Deterioration Scale developed by Barry Reisburg et al. for use in staging those individuals identified with Alzheimer's Disease; behaviors observed within the seven stages, treatment and intervention strategies to use within each stage to target and improve expressive, receptive and cognitive deficits.
Clinical Decision-Making for Stroke and Aphasia in the Older Adult
Authors: Hinckley Jacqueline
Published: July 2009

A patient with aphasia that is uncomplicated by other cognitive abilities will usually show a primary impairment of language. The frequency of additional cognitive impairments associated with cerebrovascular disease, multiple (silent or diagnosed) infarcts, or dementia increases with age and can complicate a single focal lesion that produces aphasia. The typical cognitive profiles of vascular dementia or dementia due to cerebrovascular disease may differ from the cognitive profile of patients with Alzheimer's dementia. In order to complete effective treatment selection, clinicians must know the cognitive profile of the patient and choose treatments accordingly. When attention, memory, and executive function are relatively preserved, strategy-based and conversation-based interventions provide the best choices to target personally relevant communication abilities. Examples of treatments in this category include PACE and Response Elaboration Training. When patients with aphasia have co-occurring episodic memory or executive function impairments, treatments that rely less on these abilities should be selected. Examples of treatments that fit these selection criteria include spaced retrieval and errorless learning. Finally, training caregivers in the use of supportive communication strategies is helpful to patients with aphasia, with or without additional cognitive complications.
Radial thermal expansion of pure and Xe-saturated bundles of single-walled carbon nanotubes at low temperatures
Authors: Dolbin A. V. , Esel’son V. B. , Gavrilko V. G. , Manzhelii V. G. , Popov S. N. , Vinnikov N. A. , Danilenko N. I. , Sundqvist B.
Published: July 2009

The radial thermal expansion coefficient αr of pure and Xe-saturated bundles of single-walled carbon nanotubes (CNTs) is measured in the interval 2.2–120K. The coefficient is positive above T=5.5K and negative at lower temperatures. The experiment was done using a low-temperature capacitance dilatometer with a sensitivity of 2×10−9cm, and the sample was prepared by compacting a CNT powder in such a way that the pressure applied oriented the nanotube axes perpendicular to the axis of the cylindrical sample. The data show that individual nanotubes have a negative thermal expansion, while the solid compacted material has a positive expansion coefficient due to expansion of the intertube volume in the bundles. Doping the nanotubes with Xe caused a sharp increase in the magnitude of αr in the whole range of temperatures used and gave rise to a peak in the dependence αr(T) in the interval 50–65K. A subsequent decrease in the Xe concentration lowered the peak considerably but had little effect on the thermal expansion coefficient of the sample outside the region of the peak. The features revealed are explained qualitatively.
IR Spectroscopy and ab initio calculations of imidazophenazine and its derivatives in a low-temperature argon matrix
Authors: Zarudnev E. S. , Karachevtsev V. A. , Plokhotnichenko A. M. , Stepan’yan S. G. , Adamovich L.
Published: July 2009

IR Spectroscopy is used for the first time to study the absorption spectra (400–1700cm−1 range) of imidazo-[4,5-d]-phenazine (F1) and its derivatives 2-methylamidazo-[4,5-d]-phenazine (F2), 2-fluorodimethylimidazo-[4,5-d]-phenazine (F3), and 1,2,3-triazolo-[4,5-d]-phenazine (F4) in a low-temperature argon matrix (10K). The spectra of these compounds are analyzed using computed frequencies and intensities of harmonic vibrations obtained by the quantum-mechanical DFT method (B3LYP∕6-31++G** and M05-2X∕6-31++G**). The low-temperature IR spectra of the compounds F1–F4 are in good agreement with the computed spectra. The spectra obtained contain bands which are common to all compounds F1–F4 as well as bands which are characteristic to each individual compound. The strongest transformations in the IR spectra of the F2–F4 compounds relative to the F1 spectrum are observed for the compound F4 where they are due to the substitution of a nitrogen atom for a carbon atom in the imidazole ring. A comparative analysis of the spectra of the isolated molecules with the spectra of polycrystalline samples in KBr pellets is performed. The structures, interaction energies, and the harmonic frequencies and their intensities are calculated for hydrogen-bonded and stack dimers of these compounds. The computed dimer spectra describe well the IR spectra of the compounds F1–F4 in KBr pellets.
Assessing the electric-field approximation to IR and Raman spectra of dilute HOD in D2O
Authors: Ljungberg Mathias P. , Lyubartsev A. P. , Nilsson Anders , Pettersson Lars G. M.
Published: July 2009

We analyze the validity of the commonly used electric-field (E-field) approximation to vibrational OH stretch Raman spectra of dilute HOD in D2O by computing the OH stretch frequency of all molecules in several different structure models, each containing around 2000 molecules. The calculations are done at the B3LYP level using clusters containing 32 molecules centered around the molecule for which the frequencies are calculated; the large cluster size is required due to significant nonlocal contributions influencing the computed frequencies. The vibrational frequencies are determined using a six-point potential optimized discrete variable representation. Raman and infrared intensities are furthermore computed to generate the spectra. We find that a quadratic fit of E-field versus frequency gives a reasonable representation of the calculated distribution of frequencies. However, the mapping depends significantly on the structural model and is thus not universal. Anharmonic couplings are calculated for several optimized clusters showing a general trend to compress the computed frequency distributions, which is in agreement with dynamical simulations (motional narrowing).
Broadband sensitive pump-probe setup for ultrafast optical switching of photonic nanostructures and semiconductors
Authors: Euser Tijmen G. , Harding Philip J. , Vos Willem L.
Published: July 2009

We describe an ultrafast time resolved pump-probe spectroscopy setup aimed at studying the switching of nanophotonic structures. Both femtosecond pump and probe pulses can be independently tuned over broad frequency range between 3850 and 21 050 cm−1. A broad pump scan range allows a large optical penetration depth, while a broad probe scan range is crucial to study strongly photonic crystals. A new data acquisition method allows for sensitive pump-probe measurements, and corrects for fluctuations in probe intensity and pump stray light. We observe a tenfold improvement of the precision of the setup compared to laser fluctuations, allowing a measurement accuracy of better than ΔR=0.07% in a 1 s measurement time. Demonstrations of the improved technique are presented for a bulk Si wafer, a three-dimensional Si inverse opal photonic bandgap crystal, and z-scan measurements of the two-photon absorption coefficient of Si, GaAs, and the three-photon absorption coefficient of GaP in the infrared wavelength range.
Nanometer-scale measurements of electronic states in InAs∕GaAs quantum dots
Authors: Dasika V. D. , Goldman R. S. , Song J. D. , Choi W. J. , Cho N. K. , Lee J. I.
Published: July 2009

We have investigated the origins of electronic states in individual (uncoupled) quantum dots (QDs) and the surrounding wetting layers (WLs) using a combination of cross-sectional scanning tunneling microscopy (XSTM) and scanning tunneling spectroscopy (STS). XSTM images reveal uncoupled ellipse-shaped QDs with 18±5nm (9±3nm) major (minor) axes. Room temperature STS spectra reveal a gradient in the effective bandgap within the QDs with smallest values near the QD core and top surfaces. The variations in effective bandgap are apparently dominated by indium composition gradients, with minimal effects due to the QD shape and strain. Indium composition gradients also dominate the effective bandgap variations in the WL.
Strain relaxation in short-period polar GaN/AlN superlattices
Authors: Kandaswamy P. K. , Bougerol C. , Jalabert D. , Ruterana P. , Monroy E.
Published: July 2009

We have investigated the strain relaxation mechanisms in short-period polar GaN/AlN superlattices deposited by plasma-assisted molecular-beam epitaxy, and designed to display intersubband transitions at 1.55 μm. In a first stage, we have identified the growth conditions to minimize strain relaxation, using a Ga excess to reduce the (0001) surface free energy of both GaN and AlN. Under these growth conditions, crack propagation is not observed, even for the tensile-strained superlattices grown on GaN templates. The initial misfit relaxation in the vicinity of the buffer occurs by the formation of a-type dislocations. The final strain state of the superlattice, reached after 10–20 periods, is independent of the substrate (either GaN or AlN templates). Once the steady-state conditions are reached, we observe a periodic partial relaxation of quantum wells and barriers. High-resolution transmission electron microscopy indicates that the periodic relaxation can be related to the presence of basal and prismatic stacking faults creating clusters with an in-plane length of tens of nanometers. The effect of these defects on the optical performance of the superlattices is discussed by simulation of electronic structure using an 8×8 k⋅p Schrödinger–Poisson solver. In the presence of basal stacking faults at the quantum well interfaces, the deviation of the e1-e2 intersubband transition with respect to the nominal value is expected to be smaller than the measured absorption line width.
Segregation and formation of MnP particles during rapid thermal annealing of Mn-implanted InP and GaP
Authors: Bucsa I. G. , Cochrane R. W. , Roorda S.
Published: July 2009

We have studied the structural and magnetic properties of Mn implanted (1–5×1016 cm−2, 200 keV) into InP and GaP substrates, before and after rapid thermal annealing. As revealed by Rutherford backscattering spectrometry, secondary ion mass spectrometry, and transmission electron microscopy measurements, implantation results in an amorphous surface layer 300 nm deep, and subsequent annealing gives rise to epitaxial recrystallization of this layer accompanied by a segregation of most of the Mn into clusters about 60 nm in diameter at the surface. Magnetic measurements indicate ferromagnetic behavior only for the annealed samples with TC close to 290 K, characteristic of bulk MnP, whose presence is confirmed by diffraction data. In addition, there is no evident dependence of the magnetic and structural properties on the doping type or level of the substrates.
A planar-type surface-wave plasma source with a subwavelength diffraction grating inclusion for large-area plasma applications
Authors: Chen Zhaoquan , Liu Minghai , Tang Liang , Hu Peng , Hu Xiwei
Published: July 2009

The electromagnetic wave through the subwavelength diffraction grating can be largely absorbed by surface-wave plasmas (SWPs). A SWP source is built with two slot-array antennas element. Due to the dissipation of surface waves in overdense plasmas, this source can provide remarkable discharge efficiency of 4.4 cm2/W experimentally and 96% of incident power numerically. When the applied power as low as 200 W is supplied to the SWP source, a homogeneous plasma with the uniform area up to 14×36 cm2 and the plasma density up to 1.04×1018 m−3 is generated under the quartz slab. By varying the incident power and gas pressure, the parameter of plasmas can be easily controlled without density jumping. Moreover, the characters of bi-Maxwellian electron energy distribution prove that our SWP source yield plasmas by surface heating actually. These excellent performances make the proposed source meet the requirements in large-area plasma processing and also give its advices for plasmas heating in next meter-size SWP sources.