bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of Childhood Epilepsy and Distribution of Epileptic Syndromes: A Population‐based Survey in Okayama, Japan
Authors: Oka Eiji , Ohtsuka Yoko , Yoshinaga Harumi , Murakami Nagako , Kobayashi Katsuhiro , Ogino Tatsuya
Published: March 2006

Summary:  Methods: Information on patients younger than 13 years with active epilepsy was collected from medical records. Patients diagnosed with epilepsy according to clinical and EEG findings were put on the list even if those patients had had a single seizure or seizures occurring during febrile episodes.

Results: In total, 2,220 cases were identified from a background population of 250,997. The prevalence rate was 8.8 per 1,000. If we exclude patients who had experienced a single seizure or seizures occurring during febrile episodes to compare our results with previous reports, the prevalence rate was 5.3 per 1,000. Of the 2,220 cases, 2,030 (91.4%) were classified into three major categories by ILAE classification. They consisted of 1,556 (76.7%) with localization‐related epilepsy, 453 (22.3%) with generalized epilepsy, and 21 (1.0%) with undetermined epilepsy. Of the 2,030 cases, 309 (15.2%) were classified into epileptic syndrome categories, and 84.8% of the total were nonspecific types of epilepsy.

Conclusions: The prevalence rate of childhood epilepsy was distributed from 5.3 to 8.8 per 1,000. The appearance rate of various types of epileptic syndromes was low. Most cases could not be classified into the detailed categories of the International Classification (ILAE, 1989).
Hypersalivation in Temporal Lobe Epilepsy
Authors: Shah Jagdish , Zhai Huifang , Fuerst Darren , Watson Craig
Published: March 2006

Summary:  Purpose: We sought to determine whether hypersalivation helps lateralize seizure onset during complex partial seizures of temporal lobe origin. Several clinical signs, which help lateralize seizure onset, have been reported in temporal lobe epilepsy (TLE). Increased salivation only occasionally has been reported as a manifestation of partial epilepsy.

Methods: Of 590 consecutive patients admitted for video‐EEG monitoring, either as a part of a presurgical evaluation of medically intractable epilepsy or for diagnosis and clarification of their paroxysmal symptoms, we identified 10 patients with ictal hypersalivation as a prominent manifestation of complex partial seizures. We reviewed the clinical features, scalp‐sphenoidal video‐EEG monitoring, intracarotid amytal (Wada) testing, hippocampal volumetric magnetic resonance imaging (MRI), and fluorodeoxyglucose–positron emission tomography (FDG‐PET) scans of these patients.

Results: Of the 10 patients with ictal hypersalivation, seven patients had nondominant/right TLE, and three patients had dominant/left TLE. All patients had hippocampal atrophy on volumetric MRI. Eight of the 10 patients underwent standard temporal lobectomy with amygdalohippocampectomy (six right, two left). All of the operated‐on patients had a seizure‐free (Engel class I) outcome, and their increased salivation resolved. Two patients, who did not undergo surgical treatment, continue to have complex partial seizures with increased salivation.

Conclusions: We conclude that increased salivation as a prominent ictal finding in complex partial seizures of temporal lobe origin is more likely to be of nondominant temporal lobe origin. Further studies with larger numbers of patients are needed to replicate this finding.
Functional Analysis of Cav3.2 T‐type Calcium Channel Mutations Linked to Childhood Absence Epilepsy
Authors: Peloquin Jean B. , Khosravani Houman , Barr Wendy , Bladen Chris , Evans Rhian , Mezeyova Janette , Parker David , Snutch Terrance P. , McRory John E. , Zamponi Gerald W.
Published: March 2006

Summary:  Purpose: Childhood absence epilepsy (CAE) is an idiopathic form of seizure disorder that is believed to have a genetic basis.

Methods: We examined the biophysical consequences of seven mutations in the Cav3.2 T‐type calcium channel gene linked to CAE.

Results: Of the channel variants examined, one of the mutants, a replacement of glycine 848 in the domain II‐S2 region with serine, resulted in significant slowing of the time courses of both activation and inactivation across a wide range of membrane potentials. These changes are consistent with increased channel activity in response to prolonged membrane depolarizations.

Conclusions: Taken together, these findings suggest that such little changes in channel gating may contribute to the etiology of CAE.
Depression assessed over 1‐year survival in patients with myocardial infarction
Authors: Sørensen C. , Brandes A. , Hendricks O. , Thrane J. , Friis‐Hasché E. , Haghfelt T. , Bech P.
Published: March 2006

Objective:  To estimate the prevalence of ICD‐10 depression using a self‐reported questionnaire and to examine if depression is associated with increased 1‐year mortality in patients with myocardial infarction (MI).

Method:  In total, 763 MI‐patients completed the Major Depression Inventory at discharge. Information from hospital notes was collected and patients were followed 1 year for re‐admission and mortality through national registries.

Results:  Seventy‐three patients (9.6%) were depressed at discharge. Depression was not a significant independent predictor of mortality; however, there was a significant trend for increasing mortality with increasing severity of the depressive state (P = 0.028). All mortality among depressed patients was in patients with non‐Q‐wave infarction.

Conclusion:  Ten per cent of MI‐patients fulfilled diagnostic criteria for depression at discharge. There was a significant trend for increasing mortality with increasing severity of the depressive episode. All mortality among depressed patients was seen in patients with non‐Q‐wave infarction. These findings indicate future studies in selected subgroups of MI‐patients.
Oculocutaneous albinism with TYRP1 gene mutations in a Caucasian patient
Authors: Rooryck Caroline , Roudaut Christel , Robine Eulalie , Müsebeck Jörg , Arveiler Benoît
Published: March 2006

Non‐syndromic oculocutaneous albinism (OCA) is a clinically and genetically heterogeneous autosomal recessive disorder with mutations identified in several genes: OCA1 (tyrosinase, TYR), OCA2 (OCA2), OCA3 (tyrosinase‐related protein 1, TYRP1), and OCA4 (membrane‐associated transporter protein, MATP). OCA3 was thought to be restricted to black populations, where it was clinically described as rufous or brown albinism, until the recent report of a homozygous TYRP1 mutation in Caucasian patients from a consanguineous Pakistani family. Here, we describe a German patient of Caucasian origin, with a light‐yellow skin, yellow‐gold hair with orange highlights, fair eyelashes, several pigmented naevi, and no tendency to tan, only to burn. Eye‐colour is blue‐green with substance defects of the iris. Molecular analysis did not reveal any mutation in the TYR and OCA2 genes. Two mutations were found in the TYRP1 gene: a missense mutation (c.1066G>A/p.Arg356Glu) that was inherited from the mother, and a de novo single‐base deletion (c.106delT/p.Leu36X). This finding suggests that mutation screening should be extended to the TYRP1 gene in patients from all ethnic origins, at least in cases where no mutations have been identified in the other OCA genes.
A polymorphism in the agouti signalling protein (ASIP) is associated with decreased levels of mRNA
Authors: Voisey J. , Gomez‐Cabrera M. del C. , Smit D. J. , Leonard J. H. , Sturm R. A. , Van Daal A.
Published: March 2006

To date, a role for agouti signalling protein (ASIP) in human pigmentation has not been well characterized. It is known that agouti plays a pivotal role in the pigment switch from the dark eumelanin to the light pheomelanin in the mouse. However, because humans do not have an agouti banded hair pattern, its role in human pigmentation has been questioned. We previously identified a single polymorphism in the 3′‐untranslated region (UTR) of ASIP that was found at a higher frequency in African‐Americans compared with other population groups. To compare allele frequencies between European‐Australians and indigenous Australians, the g.8818A → G polymorphism was genotyped. Significant differences were seen in allele frequencies between these groups (P < 0.0001) with carriage of the G allele highest in Australian Aborigines. In the Caucasian sample set a strong association was observed between the G allele and dark hair colour (P = 0.004) (odds ratio 4.6; 95% CI 1.4–15.27). The functional consequences of this polymorphism are not known but it was postulated that it might result in message instability and premature degradation of the transcript. To test this hypothesis, ASIP mRNA levels were quantified in melanocytes carrying the variant and non‐variant alleles. Using quantitative real‐time polymerase chain reaction the mean ASIP mRNA ratio of the AA genotype to the AG genotype was 12 (P < 0.05). This study suggests that the 3′‐UTR polymorphism results in decreased levels of ASIP and therefore less pheomelanin production.
CHANGES IN QUALITY OF CHICKEN CURRY DURING FROZEN STORAGE
Authors: MODI V.K. , SACHINDRA N.M. , SATHISHA A.D. , MAHENDRAKAR N.S. , NARASIMHA RAO D.
Published: March 2006

Chicken curry, a popular traditional Indian recipe, was prepared by using deboned broiler meat chunks and spices. The product containing both meat chunks and gravy (1.0:2.5) was packed in polyethylene pouches, placed in waxed cartons and frozen and stored at −18 ± 2C for 6 months. During frozen storage, the free fatty acid (FFA) values (as percentage oleic acid) and thiobarbituric acid (TBA) values (mg malonaldehyde/kg sample) increased in both meat and gravy. Meat and gravy pH were in the range of 5.7–6.0. Marginal decreases in shear force values (34.5–30.0 N) for meat and in viscosity values (199.4–141.6 mP) for gravy were also observed. Similarly, the changes in Hunter color (L*, a*, b*) values were also marginal. Standard plate counts (SPC), spore counts and psychrophilic counts (log cfu/g) were 4.5, 2.2 and 2.1, respectively, in freshly prepared product and on storage for 6 months at −18 ± 2C, the corresponding counts were 2.3, 2.4 and 1.6, indicating that the product was microbiologically safe. Sensory scores indicated the ready‐to‐use chicken curry was acceptable after storage at −18 ± 2C for 6 months.
Extremely Alkaline (pH > 12) Ground Water Hosts Diverse Microbial Community
Authors: Roadcap George S. , Sanford Robert A. , Jin Qusheng , Pardinas José R. , Bethke Craig M.
Published: March 2006

Chemically unusual ground water can provide an environment for novel communities of bacteria to develop. Here, we describe a diverse microbial community that inhabits extremely alkaline (pH > 12) ground water from the Lake Calumet area of Chicago, Illinois, where historic dumping of steel slag has filled in a wetland. Using microbial 16S ribosomal ribonucleic acid gene sequencing and microcosm experiments, we confirmed the presence and growth of a variety of alkaliphilic β‐Proteobacteria, Bacillus, and Clostridium species at pH up to 13.2. Many of the bacterial sequences most closely matched those of other alkaliphiles found in more moderately alkaline water around the world. Oxidation of dihydrogen produced by reaction of water with steel slag is likely a primary energy source to the community. The widespread occurrence of iron‐oxidizing bacteria suggests that reduced iron serves as an additional energy source. These results extend upward the known range of pH tolerance for a microbial community by as much as 2 pH units. The community may provide a source of novel microbes and enzymes that can be exploited under alkaline conditions.
Human critical power–oxygen uptake relationship at different pedalling frequencies
Authors: Barker Tyler , Poole David C. , Noble M. Larry , Barstow Thomas J.
Published: March 2006

Critical power (CP) is lower at faster rather than slower pedalling frequencies and traditionally reported in watts (W). Faster pedalling frequencies also engender a greater metabolic rate
at low work rates, but with progressive increases in power output, the initial difference in
between fast and slower pedalling frequencies is reduced. We tested the hypothesis that CP represents a unique metabolic rate for any given individual which would be similar at different pedalling frequencies. Eleven collegiate athletes (five cross‐country runners, END; six sprinters, SPR), aged 18–23 years, performed exhaustive rides at either 60 or 100 r.p.m. on separate days for the determination of the pedal rate‐specific CP. The
at CP (CP‐
) was determined from an 8 min ride at the CP for each pedal frequency. The group mean CP was significantly lower at 100 r.p.m. (189 ± 50 W) compared to 60 r.p.m. (207 ± 53 W, P < 0.05). However, the group mean CP‐
values at 60 (2.53 ± 0.60 l min−1) and 100 r.p.m. (2.58 ± 0.53 l min−1) were not significantly different. Critical power was significantly higher in the END athletes (242 ± 50 W at 60 r.p.m.; 221 ± 56 W at 100 r.p.m.) compared to SPR athletes at both pedal frequencies (177 ± 38 W at 60 r.p.m.; 162 ± 27 W at 100 r.p.m., P < 0.05), but the CP‐
was not (P > 0.05). However, when the CP‐
was scaled to body weight, the END athletes had a significantly greater CP‐
(41.3 ± 4.1 ml min−1 kg−1 at 60 r.p.m.; 40.8 ± 5.5 ml min−1 kg−1 at 100 r.p.m.) compared to the SPR athletes at both pedal frequencies (27.7 ± 4.6 ml min−1 kg−1 at 60 r.p.m.; 29.4 ± 2.8 ml min−1 kg−1 at 100 r.p.m., P < 0.05). We conclude that CP represents a specific metabolic rate
which can be achieved at different combinations of power outputs and pedalling frequencies.
Pharmacological comparison of swelling‐activated excitatory amino acid release and Cl− currents in cultured rat astrocytes
Authors: Abdullaev Iskandar F. , Rudkouskaya Alena , Schools Gary P. , Kimelberg Harold K. , Mongin Alexander A.
Published: March 2006

Ubiquitously expressed volume‐regulated anion channels (VRACs) are chloride channels which are permeable to a variety of small organic anions, including the excitatory amino acids (EAAs) glutamate and aspartate. Broad spectrum anion channel blockers strongly reduce EAA release in cerebral ischaemia and other pathological states associated with prominent astrocytic swelling. However, it is uncertain whether VRAC serves as a major pathway for EAA release from swollen cells. In the present study, we measured swelling‐activated release of EAAs as d‐[3H]aspartate efflux, and VRAC‐mediated Cl− currents by whole‐cell patch clamp in cultured rat astrocytes. We compared the pharmacological profiles of the swelling‐activated EAA release pathway and Cl− currents. The expression of candidate Cl− channels was confirmed by RT‐PCR. The maxi Cl− channel (p‐VDAC) blocker Gd3+, the ClC‐2 inhibitor Cd2+, and the MDR‐1 blocker verapamil did not affect EAA release or VRAC currents. An antagonist of calcium‐sensitive Cl− channels (CaCC), niflumic acid, had little effect on EAA release and only partially inhibited swelling‐activated Cl− currents. The phorbol ester PDBu, which blocks ClC‐3‐mediated Cl− currents, had no effect on VRAC currents and up‐regulated EAA release. In contrast, DCPIB, which selectively inhibits VRACs, potently suppressed both EAA release and VRAC currents. Two other relatively selective VRAC inhibitors, tamoxifen and phloretin, also blocked the VRAC currents and strongly reduced EAA release. Taken together, our data suggest that (i) astrocytic volume‐dependent EAA release is largely mediated by the VRAC, and (ii) the ClC‐2, ClC‐3, ClC‐4, ClC‐5, VDAC, CaCC, MDR‐1 and CFTR gene products do not contribute to EAA permeability.
Interlimb postural coordination in the standing cat
Authors: Deliagina Tatiana G. , Sirota Mikhail G. , Zelenin Pavel V. , Orlovsky Grigori N. , Beloozerova Irina N.
Published: March 2006

The dorsal‐side‐up body posture in standing quadrupeds is maintained by coordinated activity of four limbs. We studied this coordination in the cat standing on the platform periodically tilted in the frontal plane. By suspending different body parts, we unloaded one, two, or three limbs. The activity of selected extensor muscles and the contact forces under the limbs were recorded. With all four limbs on the platform, extensors of the fore‐ and hindlimbs increased their activity in parallel during ipsilateral downward tilt. With two forelimbs on the platform, this muscular pattern persisted in the forelimbs and in the suspended hindlimbs. With two hindlimbs on the platform, the muscular pattern persisted only in the hindlimbs, but not in the suspended forelimbs. These results suggest that coordination between the two girdles is based primarily on the influences of the forelimbs upon the hindlimbs. However, these influences do not necessarily determine the responses to tilt in the hindlimbs. This was demonstrated by antiphase tilting of the fore‐ and hindquarters. Under these conditions, the extensors of the fore‐ and hindlimbs appeared uncoupled and modulated in antiphase, suggesting an independent control of posture in the fore‐ and hindquarters. With only one limb supporting the shoulder or hip girdle, a muscular pattern with normal phasing was observed in both limbs of that girdle. This finding suggests that reflex mechanisms of an individual limb generate only a part of postural corrections; another part is produced on the basis of crossed influences.
Raman spectroscopy study of the influence of processing conditions on the structure of polycrystalline diamond films
Authors: Ramamurti R. , Shanov V. , Singh R. N. , Mamedov S. , Boolchand P.
Published: March 2006

Diamond films are prepared by microwave plasma-enhanced chemical-vapor deposition on Si (100) substrates using the H2–Ar–CH4 gases. Raman scattering data, including the peak position, intensity, area, and width, are analyzed in depth and used to obtain the sp3- and sp2-bonded carbon contents and the nature of internal stresses in the films. Polarization behavior of the Raman peaks is analyzed to assess its role on the quantitative analysis of the diamond films, which suggested that the 1150cm−1 Raman peak in nanocrystalline diamond films could be attributed to sp2-bonded carbon. The role of the H2∕Ar content in the gas mixture and substrate temperature on the characteristics of the diamond film is studied. Thickness and grain size of diamond films are also determined by scanning electron microscopy and related to the deposition conditions and Raman results. Deposition conditions, which led to highest sp3-bonded carbon content and growth rate, are identified.
Phase transformations of sputtered ZrV2 films after annealing and hydrogenation
Authors: Shi L. Q. , Xu S. L.
Published: March 2006

ZrV 2 thin films were prepared using a direct current (dc)-magnetron-sputtering method. The composition and the phase structure after annealing and hydrogenation were investigated by Rutherford backscattering and x-ray-diffraction technologies. The composition of the films deposited at different substrate temperatures are uniformly distributed along the depth of films. The amorphous phase consisting of Zr and V atoms was achieved when the substrate temperature was less than 400°C. But at high temperatures, e.g., 600°C, the multiphase mixture consisted of C14 (MgZn2) and C15 (MgCu2) Laves phases, Zr3V3O,α-Zr, and V forms. The annealing caused the segregation of Zr and V in the film by strain-driven diffusion and leads to nonhomogeneity, which is the main reason why the multiphase coexists there. With increasing annealing temperature, the amount of the stable C15 phase increases, while the amount of the other C14, α-Zr, and V phases decreases. Hydrogenation could spur phase transformation from the multiphase structure to a stable Laves structure at relatively low temperature.
c
-axis inclined ZnO films for shear-wave transducers deposited by reactive sputtering using an additional blind
Authors: Link M. , Schreiter M. , Weber J. , Gabl R. , Pitzer D. , Primig R. , Wersing W. , Assouar M. B. , Elmazria O.
Published: March 2006

This article reports on the growth and characterization of polycrystalline ZnO films having c axis inclined up to 16° with respect to the substrate normal. These films allow the excitation of shear and longitudinal waves with comparable electromechanical coupling constants and are of significant interest for thin film bulk acoustic resonators (FBARs). The films are deposited on silicon substrates covered by Al2O3 and SiO2 buffer layers under low pressure using a modified reactive dc-pulsed magnetron sputtering system. A blind has been positioned between target and substrate, allowing oblique particle incidence without tilting the wafer. The study of structural properties of the deposited ZnO films by x-ray diffraction and scanning electron microscopy has permitted to show the presence of the inclined structure. Electromechanical coupling constants K up to 13% have been extracted for shear-mode excitation using highly overmoded FBARs.
Effects of deposition conditions on gas-barrier performance of SiOxNy thin films formed via ion-beam-assisted vapor deposition
Authors: Kobayashi T. , Nakano Y. , Ogawa M. , Hashimoto R. , Kamikawa S. , Itoh Y.
Published: March 2006

Si O x N y thin films were synthesized via ion-beam-assisted vapor deposition (IVD) where deposition of SiOx was irradiated by nitrogen ions. Firstly, reasonable-cost evaporation materials showing less splashing for the SiOx films were investigated by selecting appropriate sintering condition regimes of Si and SiO2 mixed powders. The SiOxNy thin films on a polyethylene terephtalate film substrate obtained via IVD showed a low oxygen transmission rate (OTR) of less than 1cm3∕m2day. Effective nitrogen ion irradiation energy per atom was 8eV∕at. or greater, which is consistent with regimes where densification of thin films is reported to occur. Higher N2 partial pressure yielded a lower OTR and a higher nitrogen atomic ratio of the films obtained. It is suggested that the improvement in gas-barrier performance resulted from densification and chemical change of the films due to energy addition and nitrification produced by nitrogen ion-beam irradiation.
Speed-controlled particle injection into a low-pressure system
Authors: Kim Jung Hyeun , Fissan Heinz , Asbach Christof , Yook Se-Jin , Pui David Y. H.
Published: March 2006

Protection of extreme ultraviolet lithography (EUVL) masks from any particles (existing inside the manufacturing process or particles generated by equipment motion) is a major concern for the success of deploying the EUVL technology. Under the low-pressure levels (e.g., ⩽50mTorr) in EUVL scanners, thermophoresis is considered as the most promising noncontact method to protect mask surfaces from any possible particle contamination during vacuum exposure. In order to better test the protection capability of thermophoresis we developed a method to supply particles with known speed into a low-pressure chamber (equipped with thermophoresis testing capability) by incorporating a dual stage particle injection system. The particle injection speed could be controlled by the volumetric flow rate through a critical orifice, the cross-sectional area of an injection tube, and the pressure ratio between the two stages. In addition, the length of the particle injection tube into the low-pressure chamber must be long enough to accurately predict the particle speed. The required tube length can be estimated by means of the particle stopping distance and a particle speed adjustment distance. Finally, the use of an axial jet arrangement for the critical orifice delivered particles through the center of the injection tube at known speed.
Investigation of hexagonal microtube ZnO on silicon by capacitance-voltage measurements
Authors: Sun Yongsheng , Liu Nuo , Zhou Xi , Deng Hong , Gao Hui , Wu Haijun , Li Yanrong
Published: March 2006

The model and the intrinsic carrier concentration of hexagonal ZnO single-crystal microtubes are investigated by capacitance-voltage (C-V) measurements. The film fabricated by hydrothermal method on p-type silicon (111) is composed of microtubes with hexagonal tubular structure, which have diameters of 3–4μm and lengths in the range of 10–20μm. In this article, the structure of ZnO∕Si was analyzed and modeled, and the total capacitance model of the sample was deduced by analyzing the C-V characteristics of the ZnO. The small-signal equivalent scheme of the sample capacitance is also obtained. The C-V profiling calculated by the model agreed with the measured C-V curve. As a simple application of the model, the intrinsic carrier-concentration distribution of ZnO was extracted.
Quantitative analysis of CN∕TiCN∕TiN multilayers and their thermal stability by Auger electron spectroscopy and Rutherford backscattering spectrometry depth profiles
Authors: Prieto P. , Morant C. , Climent-Font A. , Muñoz A. , Elizalde E. , Sanz J. M.
Published: March 2006

C N ∕ Ti C N ∕ Ti N multilayers and the respective single layers have been deposited on Si(100) substrates using a dual ion-beam sputtering system. Both the multilayers and the respective single layers have been chemically characterized by Auger electron spectroscopy (AES) depth profiling combined with factor analysis and by Rutherford backscattering spectrometry (RBS). The combination of AES and RBS allows a quantitative chemical characterization of the multilayer and the respective single layers. Whereas RBS has some difficulties to determine the in-depth distribution of the light elements along the multilayer, AES depth profiling enables their quantitative analysis and even their chemical state along the multilayer. On the contrary, RBS shows its advantages to determine the heavy elements, including the contaminants incorporated during the deposition process (e.g., W). Under special experimental conditions it is shown that RBS is able to determine the composition of the single layers (i.e., CN∕Si, TiCN∕Si, and TiN∕Si) in good agreement with AES depth profiling. As a result of this complementary use we obtain a complete quantitative chemical characterization of the single layers and multilayers. In addition, the thermal stability of the multilayers upon heating for 1h in vacuum and ambient atmospheres at 500°C has been studied by AES depth profiling. The results show that whereas the multilayer is stable in vacuum it undergoes significant changes when it is heated in air. In fact, it is shown that annealing in air for 1h causes the disappearance of the CN top layer and the oxidation of the TiCN layer that leads to the formation of TiO2 on its surface.
Structural defects in an epitaxial ZnO∕(011¯2) r-plane sapphire studied by high-resolution electron microscopy and computer simulation
Authors: Lim Sung-Hwan
Published: March 2006

The structure of planar defects in ZnO films on (011¯2) r-plane sapphire was studied by the combination of high-resolution electron microscopy and computer simulations. The dominant defects present in these films were identified as a type I1 intrinsic-stacking fault with a displacement vector of (a∕6)[202¯3] and a density of ∼6×104cm−1, lying in the (0001) basal plane. We found the formation of these stacking faults to be growth related, corresponding to the face-centered-cubic stacking sequence in wurtzite ZnO.
Inert, pulsed, ultrahigh-vacuum-compatible doser for study of hydrazine decomposition on a model Ir∕Al2O3∕NiAl(110) catalyst
Authors: Fan Chaoyang , Wu Tianpin , Anderson Scott L.
Published: March 2006

Design of a chemically inert, ultrahigh-vacuum-compatible, pulsed gas inlet system is described. The inlet design is suitable for any gases compatible with glass, Teflon, and perfluoroalkoxy materials. The performance is illustrated by results for hydrazine decomposition on a planar model Ir∕Al2O3∕NiAl(110) catalyst. The inert, pulsed inlet system makes it possible to measure decomposition products evolving from a small (2mm) Ir-containing spot, despite the high propensity for hydrazine to decompose on the surfaces of the inlet system and vacuum chamber.
High-precision determination of lattice constants and structural characterization of InN thin films
Authors: Wu M. F. , Zhou S. Q. , Vantomme A. , Huang Y. , Wang H. , Yang H.
Published: March 2006

X-ray diffraction and Rutherford backscattering/channeling were used to characterize the crystalline quality of an InN layer grown on Al2O3(0001) using metal-organic chemical-vapor deposition. A full width at half maximum of 0.27° from an InN(0002) ω scan and a minimum yield of 23% from channeling measurements show that this 480-nm-thick InN layer grown at low temperature (450°C) has a relatively good crystalline quality. High-resolution x-ray diffraction indicates that the InN layer contains a small fraction of cubic InN, besides the predominant hexagonal phase. From this InN sample, the lattice constants a=0.35376nm and c=0.57064nm for the hexagonal InN and a=0.4986nm for the cubic InN were determined independently. 2θ∕ω-χ mapping and a pole figure measurement revealed that the crystallographic relationship among the cubic InN, the hexagonal InN, and the substrate is: InN[111]‖InN[0001]‖Al2O3[0001] and InN{110}‖InN{112¯0}‖Al2O3{101¯0}, and that the cubic InN is twinned. Photoluminescence measurements indicate that the band-gap energy of this sample is approximately 0.82eV.
Low-temperature electron cyclotron resonance plasma-enhanced chemical-vapor deposition silicon dioxide as gate insulator for polycrystalline silicon thin-film transistors
Authors: Maiolo L. , Pecora A. , Fortunato G. , Young N. D.
Published: March 2006

Silicon dioxide films have been deposited at temperatures below 270°C in an electron cyclotron resonance (ECR) plasma reactor from O2, SiH4, and He gas mixture. Pinhole density analysis as a function of substrate temperature for different microwave powers was carried out. Films deposited at higher microwave power and at room temperature show defect densities (<7pinhole∕mm2), ensuring low-temperature process integration on large area. From Fourier transform infrared analysis and thermal desorption spectrometry we also evaluated very low hydrogen content if compared to conventional rf-plasma-enhanced chemical-vapor-deposited (PECVD) SiO2 deposited at 350°C. Electrical properties have been measured in metal-oxide-semiconductor (MOS) capacitors, depositing SiO2 at RT as gate dielectric; breakdown electric fields >10MV∕cm and charge trapping at fields >6MV∕cm have been evaluated. From the study of interface quality in MOS capacitors, we found that even for low annealing temperature (200°C), it is possible to considerably reduce the interface state density down to 5×1011cm−2eV−1. To fully validate the ECR-PECVD silicon dioxide we fabricated polycrystalline silicon thin-film transistors using RT-deposited SiO2 as gate insulator. Different postdeposition thermal treatments have been studied and good device characteristics were obtained even for annealing temperature as low as 200°C.
Structure of surface reaction layer of poly-Si etched by fluorocarbon plasma
Authors: Kurihara Kazuaki , Egami Akihiko , Nakamura Moritaka
Published: March 2006

A structure of surface reaction layer of poly-Si substrate during fluorocarbon plasma etching was studied by using a plasma beam irradiation apparatus and a quasi-in situ x-ray photoelectron spectroscopy. A fluorinated silicon (SiF) layer was formed under a fluorocarbon (CF) layer. It was found that the thickness of the SiF layer linearly increased with the etch yield of poly-Si regardless of the change of the CF layer thickness. The average ratio of the number of Si to that of F in the SiF layer did not strongly depend on the etch yield. The carbon-rich region of the CF layer was formed just above the SiF layer due to the consumption of fluorine for the formation of SiF layer.
Plasma enhanced chemical vapor deposition of silicon oxide films with divinyldimethylsilane and tetravinylsilane
Authors: Park Sung-Gyu , Rhee Shi-Woo
Published: March 2006

Carbon-doped silicon oxide (SiCOH) low-k films were deposited with plasma enhanced chemical vapor deposition (PECVD) using divinyldimethylsilane (DVDMS) with two vinyl groups and tetravinylsilane (TVS) with four vinyl groups compared with vinyltrimethylsilane (VTMS) with one vinyl group. With more vinyl groups in the precursor, due to the crosslinking of the vinyl groups, the film contains more of an organic phase and organic phase became less volatile. It was confirmed that the deposition rate, refractive index, and k value increase with more vinyl groups in the precursor molecule. After annealing, the SiCOH films deposited with DVDMS and TVS showed a low dielectric constant of 2.2 and 2.4 at optimum conditions, respectively. In both cases, the annealed film had low leakage current density (J=6.7×10−7A∕cm2 for SiCOH film of DVDMS and J=1.18×10−8A∕cm2 for SiCOH film of TVS at 1MV∕cm) and relatively high breakdown field strength (E>4.0MV∕cm at 1mA∕cm2), which is comparable to those of PECVD SiO2.
Stress-induced wrinkling of sputtered SiO2 films on polymethylmethacrylate
Authors: Serrano Justin R. , Xu Qinqin , Cahill David G.
Published: March 2006

Compressively stressed SiO2 films are deposited by rf magnetron sputtering onto polymethylmethacrylate- (PMMA) coated Si substrates. The oxide film roughens by wrinkling during deposition; wrinkling is enabled by the viscous flow of the PMMA layer. The nanoscale lateral length scale of the wrinkling, ∼120nm, is established during the first few nanometers of film deposition and is controlled by the thickness and stress of the SiO2 film at the onset of the instability. Continued deposition of SiO2 leads to a rapid increase and then saturation of the rms roughness at ∼5nm.
Improved durability of dielectric coatings for large-area applications on glass via ion beam pretreatment of the substrate
Authors: West G. T. , Kelly P. J.
Published: March 2006

Dielectric coatings are commonly deposited onto large-area glass substrates via the magnetron sputtering process. High refractive index materials such as titania and zinc oxide are employed in a wide range of multilayer coating systems, some of which can experience problems with coating durability. A standard magnetron sputtering system has been enhanced via the inclusion of a Hall-current-type ion source, which has been used for the pretreatment of the glass substrate surfaces prior to deposition. Resulting TiO2 and ZnO films exhibited substantial improvements in mechanical durability (up to 80% increase in critical load and 200% increase in wear resistance, as compared with those grown on untreated glass) with no detrimental effect to their optical performance. These improvements to coating performance, along with the suitability of the ion source to inclusion in commercial coaters, demonstrate a potential for significant benefit to the large-area glass coating industry.
Secondary ion mass spectrometry depth profiling of amorphous polymer multilayers using O2+ and Cs+ ion bombardment with a magnetic sector instrument
Authors: Harton S. E. , Stevie F. A. , Ade H.
Published: March 2006

Thin planar polymer films are model systems in a number of fields, including nano- and biotechnology. In contrast to reciprocal space techniques such as reflectivity or diffraction, secondary ion mass spectrometry (SIMS) can provide depth profiles of tracer labeled polymers in real space directly with sufficient depth resolution to characterize many important aspects in these systems. Yet, continued improvements in characterization methods are highly desirable in order to optimize the trade-offs between depth resolution, mass resolution, detection sensitivity, data acquisition time, and artifacts. In this context, the utility of a magnetic sector SIMS instrument for amorphous polymer film analysis was evaluated using model polymer bilayer systems of polystyrene (PS) with poly(methyl methacrylate) (PMMA), PS with poly(2-vinylpyridine), and poly(cyclohexyl methacrylate) (PCHMA) with PMMA. Deuterium-labeled polystyrene embedded in PS or PCHMA at concentrations ranging from 5% to 20%(v∕v) was used as tracer polymer. Analysis conditions for a magnetic sector SIMS instrument (CAMECA IMS-6f) were varied to achieve a depth resolution of ∼10nm, high signal/noise ratios, and high sensitivity, while minimizing matrix effects and sample charging. Use of Cs+ and O2+ primary ions with detection of negative and positive secondary ions, respectively, has been explored. Primary beam impact energy and primary ion species have been shown to affect matrix secondary ion yields. Sputtering rates have been determined for PS and PMMA using both primary ion species and referenced to values for intrinsic (100) silicon (Si) under identical analysis conditions.
Feature scale model of Si etching in SF6∕O2∕HBr plasma and comparison with experiments
Authors: Belen Rodolfo Jun , Gomez Sergi , Kiehlbauch Mark , Aydil Eray S.
Published: March 2006

We have developed a semiempirical feature scale model of Si etching in SF6∕O2∕HBr plasma. Surface kinetics are modeled using parameters that describe F-based Si etching in SF6 and SF6∕O2 plasmas and Br-based Si etching in HBr plasma. The kinetic parameters in the model are constrained by matching simulated feature profiles with those experimentally obtained at various feed gas compositions. Excellent agreement between experiments and simulations is obtained. The combined experimental and profile simulation study reveals that the addition of HBr to SF6∕O2 plasmas results in improved sidewall passivation and elimination of the mask undercut. The vertical etch rate increases as a result of F and Br fluxes focusing toward the bottom of the feature by reflections from passivated sidewalls. Addition of SF6 to HBr discharge increases the etch rate through chemical etching that produces volatile SiBr4−xFx etch products and ion-enhanced chemical sputtering of fluorinated and brominated Si surfaces by F-containing ions.
Late Colonization of Easter Island
Authors: Hunt Terry L. , Lipo Carl P.
Published: March 2006

Easter Island (Rapa Nui) provides a model of human-induced environmental degradation. A reliable chronology is central to understanding the cultural, ecological, and demographic processes involved. Radiocarbon dates for the earliest stratigraphic layers at Anakena, Easter Island, and analysis of previous radiocarbon dates imply that the island was colonized late, about 1200 A.D. Substantial ecological impacts and major cultural investments in monumental architecture and statuary thus began soon after initial settlement.
Vastus lateralis oxygenation during prolonged cycling in healthy males
Authors: Kawaguchi Kotaro , Hayashi Yukiko , Sekikawa Kiyokazu , Tabusadani Mitsuru , Inamizu Tsutomu , Onari Kiyoshi , Bhambhani Yagesh
Published: March 2006

This study examined the relationship between acute cardiorespiratory and muscle oxygenation and blood volume changes during prolonged exercise. Eight healthy male volunteers (mean maximum oxygen uptake ([Formula: see text]O2max) = 41.6 ± 2.4 mL/kg/min) performed 60 min submaximal cycling at 50% [Formula: see text]O2max. Oxygen uptake ([Formula: see text]O2) was measured by indirect spirometry, cardiac output (CO) was estimated using a PortapresTM, and right vastus lateralis oxyhemoglobin/ myoglobin (oxyHb/Mb), deoxyhemoglobin/myoglobin (deoxyHb/Mb), and total hemoglobin/myoglobin (total Hb/Mb) were recorded using near-infrared spectroscopy (NIRS). After 40 min of exercise, there was a significant increase in [Formula: see text]O2 due to a significantly higher arteriovenous oxygen difference ((a - v)O2diff). After 30 min of exercise CO remained unchanged, but there was a significant decrease in stroke volume and a proportionate increase in heart rate, thus indicating the occurrence of cardiovascular drift. During the first few minutes of exercise, there was a decline in oxyHb/Mb and total Hb/Mb, whereas deoxyHb/Mb remained unchanged. Thereafter, oxyHb/Mb and total Hb/Mb increased systematically until the termination of exercise while deoxyHb/Mb declined. After 40 min of exercise, these changes were significantly different from the baseline values. There were no significant correlations between the changes in the NIRS variables and systemic [Formula: see text]O2 or mixed (a - v)O2diff during exercise. These results suggest that factors other than localized changes in muscle oxygenation and blood volume account for the increased [Formula: see text]O2 during prolonged submaximal exercise. Key words: near infrared spectroscopy, cardiovascular drift, systemic oxygen consumption.
Distribution of monocarboxylate transporters MCT1-MCT8 in rat tissues and human skeletal muscle
Authors: Bonen Arend , Heynen Miriam , Hatta Hideo
Published: March 2006

In the past decade, a family of monocarboxylate transporters (MCTs) have been identified that can potentially transport lactate, pyruvate, ketone bodies, and branched-chain ketoacids. Currently, 14 such MCTs are known. However, many orphan transporters exist that have transport capacities that remain to be determined. In addition, the tissue distribution of many of these MCTs is not well defined. Such a cataloging can, at times, begin to suggest the metabolic role of a particular MCT. Recently, a number of antibodies against selected MCTs (MCT1, -2, -4, and -5 to -8) have become commercially available. Therefore, we examined the protein expression of these MCTs in a large number of rat tissues (heart, skeletal muscle, skin, brain, testes, vas deferens, adipose tissue, liver, kidney, spleen, and pancreas), as well as in human skeletal muscle. Unexpectedly, many tissues coexpressed 4-5 MCTs. In particular, in rat skeletal muscle MCT1, MCT2, MCT4, MCT5, and MCT6 were observed. In human muscle, these same MCTs were present. We also observed a pronounced MCT7 signal in human muscle, whereas a very faint signal occurred for MCT8. In rat heart, which is an important metabolic sink for lactate, we confirmed that MCT1 and -2 were expressed. In addition, MCT6 and -8 were also prominently expressed in this tissue, although it is known that MCT8 does not transport aromatic amino acids or lactate. This catalog of MCTs in skeletal muscle and other tissues has revealed an unexpected complexity of coexpression, which makes it difficult to associate changes in monocarboxylate transport with the expression of a particular MCT. The differences in transport kinetics for lactate and pyruvate are only known for MCT1, -2 and -4. Transport kinetics remain to be established for many other MCTs. In conclusion, this study suggests that in skeletal muscle, as well as other tissues, lactate and pyruvate transport rates may not only involve MCT1 and -4, as other monocarboxylate transporters are also expressed in rat (MCT2, -5, -6) and human skeletal muscle (MCT2, -5, -6, -7).Key words: muscle, lactate, pyruvate, human, rat.
Physiological adaptation in early human pregnancy: adaptation to balance maternal-fetal demands
Authors: Weissgerber Tracey L , Wolfe Larry A
Published: March 2006

After conception, the corpus luteum, placenta, and developing embryo release hormones, growth factors, and other substances into the maternal circulation. These substances trigger a cascade of events that transform the functioning of the maternal cardiovascular, respiratory, and renal systems, which in turn alter the physicochemical determinants of [H+]. Following implantation, maternal adaptations fulfill 4 important functions that support fetal growth. Increased availability of substrates and precursors for fetal-placental metabolism and hormone production is mediated by increases in dietary intake, as well as endocrine changes that increase the availability of glucose and low-density lipoprotein (LDL) cholesterol. Transport capacity is enhanced by increases in cardiac output, facilitating the transport of substrates and precursors to the placenta, and fetal waste products to maternal organs for disposal. Maternal-fetal exchange is regulated by the placenta after 10-12 weeks gestation, but it may occur through histiotrophic mechanisms before this time. Disposal of additional waste products (heat, carbon dioxide, and metabolic byproducts) occurs through peripheral vasodilation and increases in skin blood flow, ventilation, and renal filtration. The maternal physiological adaptations described above must meet the combined demands of maternal exercise and fetal growth. More research is needed to formulate evidence-based guidelines for healthy physical activity in early pregnancy.Key words: maternal adaptation, first trimester, exercise, fetal growth and development, hormones.
What can metabolic myopathies teach us about exercise physiology?
Authors: Tarnopolsky Mark A
Published: March 2006

Exercise physiologists are interested in metabolic myopathies because they demonstrate how knocking out a component of a specific biochemical pathway can alter cellular metabolism. McArdle's disease (myophosphorylase deficiency) has often been studied in exercise physiology to demonstrate the influence of removing the major anaerobic energy supply to skeletal muscle. Studies of patients with McArdle's disease have shown the increased reliance on blood-borne fuels, the importance of glycogen to maximal aerobic capacity, and the use of nutritional strategies to bypass metabolic defects. Myoadenylate deaminase deficiency is the most common metabolic enzyme deficiency in human skeletal muscle. It is usually compensated for endogenously and does not have a major influence on high-energy power output. Nutritional interventions such as carbohydrate loading and carbohydrate supplementation during exercise are essential components of therapy for patients with fatty acid oxidation defects. Cases of mitochondrial myopathies illustrate the importance of peripheral oxygen extraction for maximal aerobic capacity and show how both exercise and nutritional interventions can partially compensate for these mutations. In summary, metabolic myopathies provide important insights into regulatory and nutritional aspects of the major biochemical pathways of intermediary metabolism in human skeletal muscle. Key words: myoadenylate deaminase deficiency, MELAS syndrome, McArdle's disease, mitochondrial disease, inborn errors of metabolism.
Introduction to Dietary Reference Intakes
Authors: Barr Susan I
Published: March 2006

Dietary Reference Intakes (DRIs) are nutrient reference standards used for planning and assessing the diets of apparently healthy Canadians and Americans. The development of DRIs reflects a joint initiative by the United States and Canada to update, expand on, and replace the former Recommended Nutrient Intakes for Canadians and Recommended Dietary Allowances for Americans. DRIs include the Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), Adequate Intake (AI), and Tolerable Upper Intake Level (UL). The EAR is the average daily intake level that meets the requirement of 50% of healthy individuals in a life stage and gender group, whereas the RDA is set at a level that will meet the requirements of almost all (97%-98%) individuals in that life stage and gender group. An AI is a recommended intake level that is thought to meet the needs of almost all healthy individuals, and is set when there are insufficient data to establish an EAR (and therefore an RDA). The UL represents a threshold above which adverse effects of excessive intake may increase. In addition to these DRIs, macro nutrients have an Acceptable Macro nutrient Distribution Range (AMDR) and, for energy, an Estimated Energy Requirement (EER) is described.Key words: nutrient reference standards, nutrient requirements, nutrient toxicity.