bluuebunny/crossref_metadata_2025 huggingface dataset:
Detrital zircon geochronology of pre-Cretaceous strata: tectonic implications for the Jiangnan Orogen, South China
Authors: SU JINBAO , DONG SHUWEN , ZHANG YUEQIAO , LI YONG , CHEN XUANHUA , CUI JIANJUN
Published: February 2014

Fifteen sandstone samples taken from pre-Cretaceous strata of the Yangtze Block are analysed to constrain the evolution of the South China Block, especially the assembly between the Yangtze and Cathaysia blocks. The results show that the maximum depositional age of the Neoproterozoic Lengjiaxi Group adjacent to the Cathaysia Block isc. 830 Ma, differing from that of the Kunyang and Dahongshan groups (> 960 Ma) on the southwestern margin of the Yangtze Block. The detrital zircons from Palaeozoic samples from the Yangtze Block have similar age populations to those in the Cathaysia Block, and they may originate from the Cathaysia Block according to palaeogeographic, palaeocurrent and former research data. The detrital zircons of Middle–Upper Jurassic sandstones in the southwestern and central Yangtze Block yield dominant age populations at 2.0–1.7 Ga and subordinate groups of 2.6–2.4 Ga, 0.8–0.7 Ga and 0.6–0.4 Ga. The Upper Triassic strata may be derived from the southern Yangtze and North China blocks due to the collisions between the Indosina, South China and North China blocks, whereas the Jurassic sediments may be partly derived from uplift and erosion of the Jiangnan Orogen due to an intracontinental orogeny induced by Pacific subduction towards the Eurasia Plate. The detrital age spectra and provenance data for basement in the South China Block are analysed and compared with each other. The South China Block has affinity with Australia not only in the Columbia supercontinent but also in the Rodinia supercontinent. We infer the existence of an ancient orogen under the western Jiangnan Orogen, which may have occurred during the Columbia age, earlier than the Sibao orogeny. This is supported by seismic profile proof from the SinoProbe.
Hyperpneumatisation of the craniocervical bones: an emerging aetiological pattern
Authors: Fussey J M , El-Maghraby H , Rejali D
Published: February 2014

Background:

Hyperpneumatisation of the skull base and upper cervical vertebrae is a very rare condition of uncertain aetiology and pathophysiology.

Case report:

A case of extensive hyperpneumatisation of the craniocervical junction and upper three cervical vertebrae is described, in a patient who habitually performed the Valsalva manoeuvre to relieve the symptoms of a patulous eustachian tube. Reported symptoms of ear, neck and shoulder pain deteriorated after minor head trauma. There was a drastic radiological and clinical improvement after ceasing to perform the Valsalva manoeuvre.

Discussion:

All reported cases of craniocervical bone hyperpneumatisation have in common a history of raised middle-ear pressure, minor trauma or both. We therefore suggest that chronically raised middle-ear pressure leads to destruction of bony tissue and pneumatisation, and that this process is able to cross joints into the cervical spine, either via micro-fractures following trauma, or as a result of congenital assimilation of the craniocervical junction.
How much do we know about schizophrenia and how well do we know it? Evidence from the Schizophrenia Library
Authors: Matheson S. L. , Shepherd A. M. , Carr V. J.
Published: February 2014

Background.

True findings about schizophrenia remain elusive; many findings are not replicated and conflicting results are common. Well-conducted systematic reviews have the ability to make robust, generalizable conclusions, with good meta-analyses potentially providing the closest estimate of the true effect size. In this paper, we undertake a systematic approach to synthesising the available evidence from well-conducted systematic reviews on schizophrenia.

Method.

Reviews were identified by searching Medline, EMBASE, CINAHL, Current Contents and PsycINFO. The decision to include or exclude reviews, data extraction and quality assessments were conducted in duplicate. Evidence was graded as high quality if reviews contained large samples and robust results; and as moderate quality if reviews contained imprecision, inconsistency, smaller samples or study designs that may be prone to bias.

Results.

High- and moderate-quality evidence shows that numerous psychosocial and biomedical treatments are effective. Patients have relatively poor cognitive functioning, and subtle, but diverse, structural brain alterations, altered electrophysiological functioning and sleep patterns, minor physical anomalies, neurological soft signs, and sensory alterations. There are markers of infection, inflammation or altered immunological parameters; and there is increased mortality from a range of causes. Risk for schizophrenia is increased with cannabis use, pregnancy and birth complications, prenatal exposure to Toxoplasma gondii, childhood central nervous system viral infections, childhood adversities, urbanicity and immigration (first and second generation), particularly in certain ethnic groups. Developmental motor delays and lower intelligence quotient in childhood and adolescence are apparent.

Conclusions.

We conclude that while our knowledge of schizophrenia is very substantial, our understanding of it remains limited.
Cortisol awakening response in patients with anorexia nervosa or bulimia nervosa: relationships to sensitivity to reward and sensitivity to punishment
Authors: Monteleone P. , Scognamiglio P. , Monteleone A. M. , Perillo D. , Maj M.
Published: February 2014

Background

Sensitivity to punishment (SP) and sensitivity to reward (SR) are personality characteristics that may have relevance for the pathophysiology of eating disorders (EDs). Moreover, personality characteristics are known to modulate the activity of the hypothalamus–pituitary–adrenal (HPA) axis, which is the main component of the endogenous stress response system. As stress has been implicated in the aetiology and the maintenance of EDs, we aimed to study the HPA axis activity in relation to SP and SR, as conceptualized by Gray's reinforcement sensitivity theory (RST), in patients with anorexia nervosa (AN) or bulimia nervosa (BN).

Method

Twenty-five women with AN, 23 women with BN and 19 healthy women volunteered for the study. HPA axis activity was assessed by measurement of the salivary cortisol awakening response (CAR). The subjects’ SP and SR were measured by the behavioural inhibition system (BIS)/behavioural approach system (BAS) scales.

Results

The CAR was significantly enhanced in AN patients, but not in BN patients, compared to healthy women. The CAR correlated significantly with BAS measures, negatively in healthy controls and positively in binge-purging AN patients and BN women. SP, measured by the BIS scale, was higher in patients than in controls.

Conclusions

These findings confirm the occurrence of an enhanced activity of the HPA axis in symptomatic AN, but not in symptomatic BN, and show for the first time that the CAR is associated with SR, as conceptualized by the RST, negatively in healthy subjects but positively in binge-purging ED patients.
A Safety Assessment of Diaspirin Cross-Linked Hemoglobin (DCLHb) in the Treatment of Hemorrhagic, Hypovolemic Shock
Authors: Przybelski Robert J. , Daily Elaine K. , Micheels Jean , Sloan Edward , Mols Pierre , Corne Luc , Koenigsberg Max D. , Bickell William H. , Thompson Dan R. , Harviel Jay D. , Cohn Stephen M.
Published: February 2014

Objective:

To determine the safety and possible efficacy of diaspirin cross-linked hemoglobin (DCLHb) in the treatment of patients in Class II–IV hemorrhagic, hypovolemic shock.

Design:

Multicenter, randomized, normal saline-controlled, dose-escalation study.

Setting:

Eleven hospitals in the U.S. and Belgium.

Subjects:

One hundred and thirty-nine (139) hospitalized patients with Class II–IV hemorrhagic, hypovolemic shock within the previous 4 hours who still were requiring therapy for shock.

Interventions:

Beginning with the lowest dose, patients were randomized to receive 50,100, or 200 mL of either 10% DCLHb or normal saline infused intravenously over 15 minutes. Following infusion of either treatment, further fluid resuscitation could be given, as necessary, to maintain perfusion. Vital signs, laboratory assessments, blood and fluid administration, complications, and adverse events were recorded at various times from the end of infusion through 72 hours after infusion.

Results:

A total of 29 (13 DCLHb- and 16 saline-treated) patients died during the study period. Adverse events were experienced by 61% of patients in the DCLHb group and 53% of patients in the saline group; serious adverse events occurred in 28% of DCLHb-treated patients and 30% of saline-treated patients. The incidence of prospectively defined, clinical complications, including renal insufficiency and renal failure, was similar between the treatment groups except for the occurrence of dysrhythmias/conduction disorders, which occurred significantly more frequently in the saline-treated patients than the DCLHb-treated patients (p = 0.041). At the highest dose level (200 mL), statistically significant between-group differences were observed with greater increases in serum amylase, LDH, the isoenzymes LD1,2,4 and 5, and CK-MB in the DCLHb group compared to the control group; none were of clinical significance. The volume of blood administered did not differ between the groups. Overall 24- and 72-hour survival rates were similar between treatment groups, although the hospital discharge rate was slightly higher in the DCLHb-treated patients (80%) compared with the saline-treated patients (74%).

Conclusion:

Administration of 50 to 200 mL of DCLHb to patients in hemorrhagic, hypovolemic shock was not associated with evidence of end organ toxuity or significant adverse events. Further studies involving larger doses and, perhaps, earlier administration of DCLHb are warranted.
Magnitude of Cognitive Dysfunction in Adults with Type 2 Diabetes: A Meta-analysis of Six Cognitive Domains and the Most Frequently Reported Neuropsychological Tests Within Domains
Authors: Palta Priya , Schneider Andrea L.C. , Biessels Geert Jan , Touradji Pegah , Hill-Briggs Felicia
Published: February 2014

The objectives were to conduct a meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards to determine effect sizes (Cohen's d) for cognitive dysfunction in adults with type 2 diabetes, relative to nondiabetic controls, and to obtain effect sizes for the most commonly reported neuropsychological tests within domains. Twenty-four studies, totaling 26,137 patients (n = 3351 with diabetes), met study inclusion criteria. Small to moderate effect sizes were obtained for five of six domains: motor function (3 studies, n = 2374; d = −0.36), executive function (12 studies, n = 1784; d = −0.33), processing speed (16 studies, n = 3076; d = −0.33), verbal memory (15 studies, n = 4,608; d = −0.28), and visual memory (6 studies, n = 1754; d = −0.26). Effect size was smallest for attention/concentration (14 studies, n = 23,143; d = −0.19). The following tests demonstrated the most notable performance decrements in diabetes samples: Grooved Pegboard (dominant hand) (d = −0.60), Rey Auditory Verbal Learning Test (immediate) (d = −0.40), Trails B (d = −0.39), Rey-Osterreith Complex Figure (delayed) (d = −0.38), Trails A (d = −0.34), and Stroop Part I (d = −0.28). This study provides effect sizes to power future epidemiological and clinical diabetes research studies examining cognitive function and to help inform the selection of neuropsychological tests. (JINS, 2014, 20, 1–14)
Serial Block-Face Imaging and its Potential for Reconstructing Diminutive Cell Systems: A Case Study from Arthropods
Authors: Lipke Elisabeth , Hörnschemeyer Thomas , Pakzad Anahita , Booth Christopher R. , Michalik Peter
Published: February 2014

Until recently, three-dimensional reconstruction on an ultrastructural level was only possible using serial section transmission electron microscopy (ssTEM). However, ssTEM is highly challenging and prone to artifacts as, e.g., section loss and image distortions. New methods, such as serial block-face scanning electron microscopy (SBFSEM) overcome these limitations and promise a high lateral resolution. However, little is known about the usability of SBFSEM in diminutive, but highly complex cellular systems. We used spider sperm (~3 µm in diameter), which fulfills these conditions, to analyze the potential of SBFSEM compared with ssTEM. Our data suggest that the resolution obtained by SBFSEM allows depicting structures on a cellular level and is sufficient to discriminate subcellular components, but is highly dependent on previous staining procedures and electron density of the target structures.
Primary mucosa-associated lymphoid tissue lymphoma of the thyroid with concomitant papillary carcinoma
Authors: Hasan Shaakir , Turaka Aruna
Published: February 2014

Objective

Papillary thyroid carcinoma combined with thyroid mucosa-associated lymphoid tissue (MALT) lymphoma is exceedingly rare and there is no standard management.

Case report

We report a rare association of MALT lymphoma of thyroid in a 60-year-old woman with Hashimoto's thyroiditis along with an incidental focus of papillary carcinoma.

Conclusion

Patients with Hashimoto's thyroiditis are prone to develop other thyroid pathology, including rare tumours such as MALT lymphoma. The differential diagnosis for a neoplasm in such patients should be wide.
Next-generation genebanking: plant genetic resources management and utilization in the sequencing era
Authors: van Treuren Rob , van Hintum Theo J. L.
Published: February 2014

Advances in sequencing technologies have made it possible to analyse large amounts of germplasm against low production costs, which has opened the door to screen genebank collections more efficiently for DNA sequence variation. The present study explores how these developments may affect the operations of genebanks and, consequently, how genebank agendas may change. It is argued that the new developments are more likely to have an impact on the user-oriented activities than the housekeeping operations of genebanks. To better facilitate the user community, genebanks may have to strengthen their core business, in particular, by improving quality management procedures and by providing access to a wider diversity of a crop's gene pool. In addition, genebanks may have to provide novel services, such as the introduction of specific user-oriented collection types, including research populations and genetically purified lines, and the development of novel information services, including plant genetic resources portals that should guide users to the information and materials of specific interest. To improve their user-oriented services, genebanks need to increase their communication and collaboration with the user community and to develop strategic alliances with this sector.
Perspectives on the policy ‘black box’: a comparative case study of orthopaedics services in England
Authors: McLeod Hugh , Millar Ross , Goodwin Nick , Powell Martin
Published: February 2014

There has been much recent debate on the impact of competition on the English National Health Service (NHS). However, studies have tended to view competition in isolation and are controversial. This study examines the impact of programme theories associated with the health system reforms, which sought to move from a dominant target-led ‘central control’ programme theory, to one based on ‘market forces’, on orthopaedics across six case-study local health economies. It draws on a realistic evaluation approach to open up the policy ‘black box’ across different contexts using a mixed methods approach: analysis of 152 interviews with key informants and analysis of waiting times and admissions. We find that the urban health economies were more successful in reaching the access targets than the rural health economies, although the gap in performance closed over time. Most interviewees were aware of the policies to increase choice and competition, but their role appeared comparatively weak. Local commissioners’ ability to influence demand appeared limited with providers’ incentives dominating service delivery. Looking forward, it is clear that the role of competition in the NHS has to be considered alongside, rather than in isolation from, other policy mechanisms.
Early Maladaptive Schemas and Personality Disorder Traits in Perpetrators of Intimate Partner Violence
Authors: Corral Carmen , Calvete Esther
Published: February 2014

Personality disorders (PDs) are highly prevalent among perpetrators of intimate partner violence (IPV). Schema Therapy proposes a number of early maladaptive schemas (EMSs) that are involved in the development of PDs. This study examined the prevalence of PD traits in a sample of men who committed violence against their partners and the relationship between EMSs domains and PD traits. With this aim,a sample of 119 convicted men completed the Young Schema Questionnaire-Short Form (YSQ-SF; Young & Brown, 1994) and the Millon Clinical Multiaxial Inventory (MCMI-III; Millon, Millon, & Davis, 1994). The results showed that the most prevalent PD traits were narcissistic (24.6%), obsessive-compulsive (21.9%), and paranoid (17.5%). These PD traits were linked to several EMSs in ways consistent with the Schema Therapy model. Namely, narcissistic PD traits were positively associated with schemas of the impaired limits domain and were negatively associated with the other-directedness domain. The paranoid PD traits were associated with the disconnection and rejection domain and the impaired autonomy and performance domain. Finally, both borderline and antisocial PD traits were associated with the disconnection and rejection domain and the impaired limits domain. These findings suggest that the assessment and modification of EMSs should be a factor to consider for inclusion in the treatment programs for perpetrators of IPV in order to provide comprehensive intervention of this population.
Differential contributions of archaeal ammonia oxidizer ecotypes to nitrification in coastal surface waters
Authors: Smith Jason M , Casciotti Karen L , Chavez Francisco P , Francis Christopher A
Published: February 2014

The occurrence of nitrification in the oceanic water column has implications extending from local effects on the structure and activity of phytoplankton communities to broader impacts on the speciation of nitrogenous nutrients and production of nitrous oxide. The ammonia-oxidizing archaea, responsible for carrying out the majority of nitrification in the sea, are present in the marine water column as two taxonomically distinct groups. Water column group A (WCA) organisms are detected at all depths, whereas Water column group B (WCB) are present primarily below the photic zone. An open question in marine biogeochemistry is whether the taxonomic definition of WCA and WCB organisms and their observed distributions correspond to distinct ecological and biogeochemical niches. We used the natural gradients in physicochemical and biological properties that upwelling establishes in surface waters to study their roles in nitrification, and how their activity—ascertained from quantification of ecotype-specific ammonia monooxygenase (amoA) genes and transcripts—varies in response to environmental fluctuations. Our results indicate a role for both ecotypes in nitrification in Monterey Bay surface waters. However, their respective contributions vary, due to their different sensitivities to surface water conditions. WCA organisms exhibited a remarkably consistent level of activity and their contribution to nitrification appears to be related to community size. WCB activity was less consistent and primarily constrained to colder, high nutrient and low chlorophyll waters. Overall, the results of our characterization yielded a strong, potentially predictive, relationship between archaeal amoA gene abundance and the rate of nitrification.
Microbial ecology of an Antarctic hypersaline lake: genomic assessment of ecophysiology among dominant haloarchaea
Authors: Williams Timothy J , Allen Michelle A , DeMaere Matthew Z , Kyrpides Nikos C , Tringe Susannah G , Woyke Tanja , Cavicchioli Ricardo
Published: February 2014

Deep Lake in Antarctica is a cold, hypersaline system where four types of haloarchaea representing distinct genera comprise >70% of the lake community: strain tADL ∼44%, strain DL31 ∼18%, Halorubrum lacusprofundi ∼10% and strain DL1 ∼0.3%. By performing comparative genomics, growth substrate assays, and analyses of distribution by lake depth, size partitioning and lake nutrient composition, we were able to infer important metabolic traits and ecophysiological characteristics of the four Antarctic haloarchaea that contribute to their hierarchical persistence and coexistence in Deep Lake. tADL is characterized by a capacity for motility via flagella (archaella) and gas vesicles, a highly saccharolytic metabolism, a preference for glycerol, and photoheterotrophic growth. In contrast, DL31 has a metabolism specialized in processing proteins and peptides, and appears to prefer an association with particulate organic matter, while lacking the genomic potential for motility. H. lacusprofundi is the least specialized, displaying a genomic potential for the utilization of diverse organic substrates. The least abundant species, DL1, is characterized by a preference for catabolism of amino acids, and is the only one species that lacks genes needed for glycerol degradation. Despite the four haloarchaea being distributed throughout the water column, our analyses describe a range of distinctive features, including preferences for substrates that are indicative of ecological niche partitioning. The individual characteristics could be responsible for shaping the composition of the haloarchaeal community throughout the lake by enabling selection of ecotypes and maintaining sympatric speciation.
Hexahapto-lanthanide interconnects between the conjugated surfaces of single-walled carbon nanotubes
Authors: Moser Matthew L. , Tian Xiaojuan , Pekker Aron , Sarkar Santanu , Bekyarova Elena , Itkis Mikhail E. , Haddon Robert C.
Published: February 2014

Organometallic bonding of lanthanide metals to the graphene sidewalls in single-walled carbon nanotube networks enhances the electrical conductivity, particularly in the case of Sm and Eu.
Fe3O4–CNTs nanocomposites: a novel and excellent catalyst in the synthesis of diarylpyrimidinones using grindstone chemistry
Authors: Safari Javad , Gandomi-Ravandi Soheila
Published: February 2014

The Fe3O4–CNTs in conjunction with grindstone chemistry have been used in this report to synthesize 5-unsubstituted pyrimidinones.
Supramolecular hydrogen-bonding assembly of silanediols with bifunctional heterocycles
Authors: Tran Ngon T. , Wilson Sean O. , Franz Annaliese K.
Published: February 2014

Silanediols are presented as supramolecular synthons with predictable hydrogen-bonding patterns based on co-crystallization and DOSY experiments.
Nickel-catalyzed chelation-assisted direct arylation of unactivated C(sp3)–H bonds with aryl halides
Authors: Li Mingliang , Dong Jiaxing , Huang Xiaolei , Li Kaizhi , Wu Qian , Song Feijie , You Jingsong
Published: February 2014

The nickel-catalyzed chelation-assisted unactivated β-C(sp3)–H bond arylation of aliphatic acid derivatives with aryl iodides/bromides has been achieved.
Heat treatment effect on the electronic and magnetic structures of nanographene sheets investigated through electron spectroscopy and conductance measurements
Authors: Takashiro Jun-ichi , Kudo Yasuhiko , Kaneko Satoshi , Takai Kazuyuki , Ishii Takafumi , Kyotani Takashi , Enoki Toshiaki , Kiguchi Manabu
Published: February 2014

Verification of edge chemistry of nanographene sheets and development of antiferromagnetic interaction between the sheets depending upon heat treatment temperature (HTT).
Rapid analysis of polyester and polyethylene blends by ion mobility-mass spectrometry
Authors: Barrère Caroline , Selmi Wahiba , Hubert-Roux Marie , Coupin Thierry , Assumani Budagwa , Afonso Carlos , Giusti Pierre
Published: February 2014

In this work ion mobility-mass spectrometry (IM-MS) coupled to an atmospheric solid analysis probe (ASAP) was used for the characterization of polymer blends involving biodegradable polymers (poly(lactic acid) (PLA), poly(butylene succinate) (PBS)) and poly(ethylene) (PE).
Using diamond layout style to boost MOSFET frequency response of analogue IC
Authors: Gimenez S.P. , Leoni R.D. , Renaux C. , Flandre D.
Published: February 2014

A way to improve the metal–oxide–semiconductor field effect transistor (MOSFET) analogue electrical performance, still little explored, is to modify their aspect form or ratio (AR) by the use of innovative layout styles. The diamond MOSFET (DM) is an example of this approach. It presents hexagonal gate geometry. This new layout structure for MOSFET induces two additional effects in comparison with the conventional (i.e. rectangular gate geometry) MOSFET (CM) counterpart, which improves the device's electrical performance: the longitudinal corner effect (LCE) and parallel association of MOSFET with different channel length effect (PAMDLE). How the diamond layout style (DLS) can significantly enhance the device's frequency response (FR) by using two different integrated circuits’ (IC) complementary metal–oxide–semiconductor (CMOS) manufacturing process technologies (bulk and silicon‐on‐insulator (SOI)) is demonstrated.
Adaptive differential amplitude pulse‐position modulation technique for optical wireless communication channels based on fuzzy logic
Authors: Abdullah Mohammad Faiz Liew , Bong Siaw Wee
Published: February 2014

Optical wireless communication has the potential for extremely high data rates of up to tens of Gb/s. In this study, a hybrid modulation technique named adaptive differential amplitude pulse‐position modulation (DAPPM) is proposed to improve channel immunity by utilising optimised modulation to channel. The unit transmission rate, channel capacity, peak‐to‐average power ratio, bandwidth requirement and power requirement of the DAPPM were determined and compared with other modulation schemes such as on–off key, pulse‐amplitude modulation, pulse‐position modulation (PPM), differential PPM and multilevel digital pulse interval modulation. The simulation results show that DAPPM gives better bandwidth and power efficiency depending on the number of amplitude level (A) and the maximum length (L) of a symbol. In addition, the fuzzy logic module is developed to assist the adaptation process of DAPPM. Mamdani fuzzy logic method is used in which the decisions made by the system will be approaching to what would be decided by the user in the real world.
Two‐dimensional location of moving targets within local areas using WiFi‐based multistatic passive radar
Authors: Falcone Paolo , Colone Fabiola , Macera Antonio , Lombardo Pierfrancesco
Published: February 2014

In this study the authors investigate the two‐dimensional target localisation capabilities of a passive radar system based on WiFi transmissions. It is well known that the most straightforward way to achieve the target position estimation in the horizontal plane with a passive radar exploits the measurements either of a single bistatic range plus a direction of arrival (DoA) or of two bistatic ranges collected by two separate receivers. However, for a practical application it is interesting to clearly define which one of the two approaches provides the passive radar target localisation with a higher accuracy and whether combining both multiple bistatic range plus DoA measurements provides a further advantage. A multistatic configuration is considered which allows to collect a set of range/Doppler/angle measurements for a given target. Different target localisation strategies are devised and compared, based on subsets of the available measurements with the aim of understanding the localisation accuracies achievable using the different combinations of measurements. Experimental results are shown based on a passive radar prototype developed and fielded at the DIET Department – Sapienza University of Rome. This will contribute to demonstrate the fruitful application of the passive radar concept for short range surveillance.
Electrostatic force between a charged sphere and a planar surface: A general solution for dielectric materials
Authors: Khachatourian Armik , Chan Ho-Kei , Stace Anthony J. , Bichoutskaia Elena
Published: February 2014

Using the bispherical coordinate system, an analytical solution describing the electrostatic force between a charged dielectric sphere and a planar dielectric surface is presented. This new solution exhibits excellent numerical convergence, and is sufficiently general as to allow for the presence of charge on both the sphere and the surface. The solution has been applied to two examples of sphere-plane interactions chosen from the literature, namely, (i) a charged lactose sphere interacting with a neutral glass surface and (ii) a charged polystyrene sphere interacting with a neutral graphite surface. Theory suggests that in both cases the electrostatic force makes a major contribution to the experimentally observed attraction at short sphere-plane separations, and that the force is much longer ranged than previously suggested.
Magnetic tunnel junction based eddy current testing probe for detection of surface defects
Authors: Cardoso F. A. , Rosado L. , Ferreira R. , Paz E. , Cardoso S. , Ramos P. M. , Piedade M. , Freitas P. P.
Published: February 2014

In recent years, magnetoresistive sensors have been applied to a large spectrum of applications from biomedical devices to industrial devices. Their high sensitivity and high spatial resolution are of special interest for eddy current based non-destructive testing. In this particular application, giant magnetoresistive sensors have been recently used for detecting surface and buried defects. Nevertheless, although very promising, magnetic tunnel junctions (MTJs) are still barely used in this application. In this work, two sensors with 6 and 10 MTJs in series were successfully fabricated, characterized, and tested on an aluminum mock-up including defects 100 μm wide and with a depth ranging from 0.2 to 1 mm. The sensors including 6 MTJ in series showed sensitivities of 50.8 mV/mT, while the sensor with 10 MTJ in series showed a sensitivity of 84.5 mV/mT. Due to its high sensitivity the latter was able to detect the smallest defect with a signal to noise ratio of 50, which seems promising for more challenging applications.
Using microfluidic chip to form brain-derived neurotrophic factor concentration gradient for studying neuron axon guidance
Authors: Huang Hui , Jiang Lili , Li Shu , Deng Jun , Li Yan , Yao Jie , Li Biyuan , Zheng Junsong
Published: February 2014

Molecular gradients play a significant role in regulating biological and pathological processes. Although conventional gradient-generators have been used for studying chemotaxis and axon guidance, there are still many limitations, including the inability to maintain stable tempo-spatial gradients and the lack of the cell monitoring in a real-time manner. To overcome these shortcomings, microfluidic devices have been developed. In this study, we developed a microfluidic gradient device for regulating neuron axon guidance. A microfluidic device enables the generation of Brain-derived neurotrophic factor (BDNF) gradient profiles in a temporal and spatial manner. We test the effect of the gradient profiles on axon guidance, in the BDNF concentration gradient axon towards the high concentration gradient. This microfluidic gradient device could be used as a powerful tool for cell biology research.
Magnetic properties and magnetocaloric effect of NdMn2−xCuxSi2 compounds
Authors: Md Din M. F. , Wang J. L. , Avdeev M. , Gu Q. F. , Zeng R. , Campbell S. J. , Kennedy S. J. , Dou S. X.
Published: February 2014

Structural and magnetic properties of NdMn2−xCuxSi2 compounds (x = 0–1.0) have been investigated by high intensity x-ray and resolution neutron diffraction (3–450 K), specific heat, dc magnetization, and differential scanning calorimetry measurements. Substitution of Cu for Mn leads to an increase in the lattice parameter a but a decrease in c at room temperature. Two magnetic phase transitions have been found for NdMn2−xCuxSi2 compounds with TN for the antiferromagnetic ordering of Mn-sublatttice and TC for the Nd-sublattice ferromagnetic ordering, respectively. TC increases significantly with increasing Cu content from 36 K at x = 0 to 100 K at x = 1.0. Moreover, it is found that the order of magnetic phase transition around TC also changes from first order at x < 0.6 to second order transition for x ≥ 0.6. The spontaneous magnetization found to decrease with the increase in Cu concentration which can be understood in the term of the dilution effect of Cu for Mn. The values of −ΔSM around TC decrease with increasing x from 27 J kg−1 K−1 for x = 0 to 0.5 J kg−1 K−1 for x = 1.0 under 0–5 T field. Refinement of neutron diffraction patterns for x = 0.2 confirms the magnetic states detected by magnetic study and also indicates that the lattice constants a and c show a distinct variation around TC.
Long-range correlation energy calculated from coupled atomic response functions
Authors: Ambrosetti Alberto , Reilly Anthony M. , DiStasio Robert A. , Tkatchenko Alexandre
Published: February 2014

An accurate determination of the electron correlation energy is an essential prerequisite for describing the structure, stability, and function in a wide variety of systems. Therefore, the development of efficient approaches for the calculation of the correlation energy (and hence the dispersion energy as well) is essential and such methods can be coupled with many density-functional approximations, local methods for the electron correlation energy, and even interatomic force fields. In this work, we build upon the previously developed many-body dispersion (MBD) framework, which is intimately linked to the random-phase approximation for the correlation energy. We separate the correlation energy into short-range contributions that are modeled by semi-local functionals and long-range contributions that are calculated by mapping the complex all-electron problem onto a set of atomic response functions coupled in the dipole approximation. We propose an effective range-separation of the coupling between the atomic response functions that extends the already broad applicability of the MBD method to non-metallic materials with highly anisotropic responses, such as layered nanostructures. Application to a variety of high-quality benchmark datasets illustrates the accuracy and applicability of the improved MBD approach, which offers the prospect of first-principles modeling of large structurally complex systems with an accurate description of the long-range correlation energy.
Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary
Authors: Kávási Norbert , Vigh Tamás , Németh Csaba , Ishikawa Tetsuo , Omori Yasutaka , Janik Miroslaw , Yonehara Hidenori
Published: February 2014

During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C–21°C), low or high wind speed (max. 2.4 m s−1) and low or elevated aerosol concentration (130–60 000 particles m−3). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m−3 and 550(497) Bq m−3 in the bauxite mine; 887(604) Bq m−3 and 1258(788) Bq m−3 in the manganese ore mine; 2510(2341) Bq m−3 and 3403(3075) Bq m−3 in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m−3 and 8512(1955) Bq m−3 in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m−3 and 161(148) Bq m−3 in the bauxite mine; 187(191) Bq m−3 and 117(147) Bq m−3 in the manganese-ore mine; 360(524) Bq m−3 and 371(789) Bq m−3 in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m−3 and 1462(3655) Bq m−3 in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves. Consequently, correction is required on previously obtained radon data acquired by CF monitors at subsurface workplaces to gain comparable data for SF monitors. In the case of thoron, the data were unreliable and no significant tendency was seen during the comparison therefore comparison of previously obtained thoron data acquired by either CF or SF is doubtful. There was probable influence by relative humidity on the detection response; however, the effects of the high wind speed and elevated aerosol concentration could not be excluded. The results of this study call attention to the importance of calibration under extreme environmental conditions and the need for using reliable radon-thoron monitors for subsurface workplaces.
Restricted diffusion of methyl groups in proteins revealed by deuteron NMR: Manifestation of intra-well dynamics
Authors: Vugmeyster Liliya , Ostrovsky Dmitry
Published: February 2014

The three-site hops of methyl groups are usually used as an approximation of the mechanistic description of motions responsible for the longitudinal NMR relaxation. Distinguishing between three-site hops and a more realistic mechanism of diffusion in a potential requires extended experimental and computational analysis. In order to achieve this goal, in this work the restricted diffusion is decomposed into two independent modes, namely, the jumps between potential wells and intra-well fluctuations, assuming time scale separation between these modes. This approach allows us to explain the rise in the theoretical value of T1 minimum for the restricted diffusion mechanism compared with the three-site hops mechanism via rescaling the three-site hops correlation function by the order parameter of intra-well motions. The main result of the paper is that, in general, intra-well dynamics can be visible in NMR even in the limit of large barrier heights in contrast to the common view that this limit converges to the three-site hops mechanism. Based on a previously collected detailed set of deuteron NMR relaxation and spectral data in the villin headpiece subdomain protein over a wide temperature range of 300–31 K, we are then able to conclude that the mechanism of diffusion in the threefold potential is likely to be the main source of the dynamics in this system.
Electronic properties of graphene nano-flakes: Energy gap, permanent dipole, termination effect, and Raman spectroscopy
Authors: Singh Sandeep Kumar , Neek-Amal M. , Peeters F. M.
Published: February 2014

The electronic properties of graphene nano-flakes (GNFs) with different edge passivation are investigated by using density functional theory. Passivation with F and H atoms is considered: \documentclass[12pt]{minimal}\begin{document}${\rm C}_{N_c}\ {\rm X}_{N_x}$\end{document}CNcXNx (X = F or H). We studied GNFs with 10 < Nc < 56 and limit ourselves to the lowest energy configurations. We found that: (i) the energy difference Δ between the highest occupied molecular orbital and the lowest unoccupied molecular orbital decreases with Nc, (ii) topological defects (pentagon and heptagon) break the symmetry of the GNFs and enhance the electric polarization, (iii) the mutual interaction of bilayer GNFs can be understood by dipole-dipole interaction which were found sensitive to the relative orientation of the GNFs, (iv) the permanent dipoles depend on the edge terminated atom, while the energy gap is independent of it, and (v) the presence of heptagon and pentagon defects in the GNFs results in the largest difference between the energy of the spin-up and spin-down electrons which is larger for the H-passivated GNFs as compared to F-passivated GNFs. Our study shows clearly the effect of geometry, size, termination, and bilayer on the electronic properties of small GNFs. This study reveals important features of graphene nano-flakes which can be detected using Raman spectroscopy.
Development of fast heating electron beam annealing setup for ultra high vacuum chamber
Authors: Das Sadhan Chandra , Majumdar Abhijit , Katiyal Sumant , Shripathi T. , Hippler R.
Published: February 2014

We report the design and development of a simple, electrically low powered and fast heating versatile electron beam annealing setup (up to 1000 °C) working with ultra high vacuum (UHV) chamber for annealing thin films and multilayer structures. The important features of the system are constant temperature control in UHV conditions for the temperature range from room temperature to 1000 ºC with sufficient power of 330 W, at constant vacuum during annealing treatment. It takes approximately 6 min to reach 1000 °C from room temperature (∼10−6 mbar) and 45 min to cool down without any extra cooling. The annealing setup consists of a UHV chamber, sample holder, heating arrangement mounted on suitable UHV electrical feed-through and electronic control and feedback systems to control the temperature within ±1 ºC of set value. The outside of the vacuum chamber is cooled by cold air of 20 °C of air conditioning machine used for the laboratory, so that chamber temperature does not go beyond 50 °C when target temperature is maximum. The probability of surface oxidation or surface contamination during annealing is examined by means of x-ray photoelectron spectroscopy of virgin Cu sample annealed at 1000 °C.
Combined current-modulation annealing induced enhancement of giant magnetoimpedance effect of Co-rich amorphous microwires
Authors: Liu Jingshun , Qin Faxiang , Chen Dongming , Shen Hongxian , Wang Huan , Xing Dawei , Phan Manh-Huong , Sun Jianfei
Published: February 2014

We report on a combined current-modulation annealing (CCMA) method, which integrates the optimized pulsed current (PC) and DC annealing techniques, for improving the giant magnetoimpedance (GMI) effect and its field sensitivity of Co-rich amorphous microwires. Relative to an as-prepared Co68.2Fe4.3B15Si12.5 wire, CCMA is shown to remarkably improve the GMI response of the wire. At 10 MHz, the maximum GMI ratio and its field sensitivity of the as-prepared wire were, respectively, increased by 3.5 and 2.28 times when subjected to CCMA. CCMA increased atomic order orientation and circumferential permeability of the wire by the co-action of high-density pulsed magnetic field energy and thermal activation energy at a PC annealing stage, as well as the formation of uniform circular magnetic domains by a stable DC magnetic field at a DC annealing stage. The magnetic moment can overcome eddy-current damping or nail-sticked action in rotational magnetization, giving rise to a double-peak feature and wider working field range (up to ±2 Oe) at relatively higher frequency (f ≥ 1 MHz).
Enhancement of the magnetic interfacial exchange energy at a specific interface in NiFe/CoO/Co trilayer thin films via ion-beam modification
Authors: Cortie D. L. , Ting Y.-W. , Chen P.-S. , Tan X. , Lin K.-W. , Klose F.
Published: February 2014

A series of ferromagnetic Ni80Fe20(55 nm)/antiferromagnetic CoO (25 to 200 nm)/ferromagnetic Co (55 nm)/SiO2(substrate) trilayer thin films were fabricated by ion-beam assisted deposition in order to understand the role of ion beam modification on the interfacial and interlayer coupling. The microstructural study using transmission electron microscopy, X-ray reflectometry, and polarised neutron reflectometry showed that ion-beam modification during the deposition process led to an oxygen-rich Co/CoO nanocomposite interface region at the bottom layer. This interface caused a high exchange bias field for the ferromagnetic cobalt. However, the exchange bias for top permalloy ferromagnet remained low, in line with expectations from the literature for the typical interfacial energy. This suggest that the ion-beam enhancement of the magnetic exchange bias is localized to the Co/CoO interface where local microstructural effects provide the dominant mechanism.
Effect of lattice deformation on exchange coupling constants in Cr2O3
Authors: Kota Yohei , Imamura Hiroshi , Sasaki Munetaka
Published: February 2014

We studied lattice deformation effect on exchange interaction in the corundum-type Cr2O3 theoretically. First-principles electronic structure calculations were performed to evaluate the total energy and exchange coupling constants of Cr2O3 under lattice deformation. We found that a few percent elastic deformation is expected via misfit strain and that the first- and second-nearest neighbor exchange coupling constants of Cr2O3 strongly depend on the lattice deformation. These results imply a possibility for improving the thermal stability of Cr2O3 based magnetoelectric devices by lattice deformation.
Contactless determination of the carrier mobility sum in silicon wafers using combined photoluminescence and photoconductance measurements
Authors: Hameiri Ziv , Rougieux Fiacre , Sinton Ron , Trupke Thorsten
Published: February 2014

A contactless method to determine the carrier mobility sum in silicon wafers, based on a comparison between photoluminescence and photoconductance measurements is presented. The method is applied to monocrystalline silicon wafers and the results are found to be in good agreement with well-established mobility models and another measurement method. The potential of the proposed method to determine the carrier mobility sum of multicrystalline and compensated silicon wafers is then demonstrated.
Enhanced quantum efficiency of amorphous silicon thin film solar cells with the inclusion of a rear-reflector thin film
Authors: Park Seungil , Yong Ji Hyung , Jun Kim Myeong , Hyeon Peck Jong , Kim Keunjoo
Published: February 2014

We investigated the growth mechanism of amorphous silicon thin films by implementing hot-wire chemical vapor deposition and fabricated thin film solar cell devices. The fabricated cells showed efficiencies of 7.5 and 8.6% for the samples without and with the rear-reflector decomposed by sputtering, respectively. The rear-reflector enhances the quantum efficiency in the infrared spectral region from 550 to 750 nm. The more stable quantum efficiency of the sample with the inclusion of a rear-reflector than the sample without the rear-reflector due to the bias effect is related to the enhancement of the short circuit current.
Deformation and fracture behavior of composite structured Ti-Nb-Al-Co(-Ni) alloys
Authors: Okulov I. V. , Kühn U. , Marr T. , Freudenberger J. , Schultz L. , Oertel C.-G. , Skrotzki W. , Eckert J.
Published: February 2014

Tensile ductility of the Ti-based composites, which consist of a β-Ti phase surrounded by ultrafine structured intermetallics, is tunable through the control of intermetallics. The two Ti-based alloys studied exhibit similar compressive yield strength (about 1000 MPa) and strain (about 35%–40%) but show a distinct difference in their tensile plasticity. The alloy Ti71.8Nb14.1Ni7.4Al6.7 fractures at the yield stress while the alloy Ti71.8Nb14.1Co7.4Al6.7 exhibits about 4.5% of tensile plastic deformation. To clarify the effect of microstructure on the deformation behavior of these alloys, tensile tests were carried out in the scanning electron microscope. It is shown that the distribution as well as the type of intermetallics affects the tensile ductility of the alloys.