bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non‐contact high precision alternative to Hg‐probe for dopant profiling in SiC
Authors: Czett Andor , Buday Csaba , Savtchouk Sasha , Marinskiy Dmitriy 
Published: September 2014

AbstractThe silicon carbide industry has been expanding in the recent years, producing a search for SiC non‐contact electrical characterization methods capable of replacing the commonly used Hg‐probe technique. In this work we present doping metrology based on the corona‐Kelvin method, which was originally developed and used for silicon IC dielectric and interface characterization. The method employs corona discharge in air to deposit precise doses of charge on the SiC surface. The corresponding depletion voltage is then measured with a Kelvin probe enabling non‐contact determination of the static charge‐voltage and capacitance‐voltage characteristics. The approach incorporates three novel elements: 1. corona charging of SiC to high depletion voltage with constant surface potential method; 2. the derivative charge‐voltage measurements for d(1/C2)/dV analysis and doping profiling; 3. surface charge neutralization with appropriate SiC illumination for repeated measurements. We demonstrate excellent repeatability and accuracy of the novel approach for n and p‐type SiC doping measurements in a range from 1014cm‐3 to mid 1018cm‐3 and excellent correlation with results obtained with mercury‐probe C‐V. Using multi‐layer epitaxial SiC structures, we further demonstrate the effectiveness of novel non‐contact depth profiling. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oxygen gettering in low‐energy arsenic or antimony ion implanted Cz‐silicon
Authors: Oberemok O. , Kladko V. , Litovchenko V. , Romanyuk B. , Popov V. , Melnik V. , Vanhellemont J. 
Published: September 2014

AbstractLow energy As or Sb ion implantation followed by furnace annealing was used to create ultra shallow junctions. It was found that a significant amount of oxygen was redistributed from the Si bulk to the As implanted layer leading even to an increase of the screening oxide film thickness. Using a marker layer created by implantation of 18O ions, it was confirmed that a large number of interstitial oxygen atoms are transferred from the bulk of the Si wafer to the wafer surface during implanted As activation annealing. Estimation of the O diffusivity in Si during the 950 °C activation anneal, yields a value of about 10–10 cm2 /s which is more than an order of magnitude larger than the literature value which is close to 7 × 10–12 cm2/s. In the case of Sb implantation, the oxygen gettering effect is much reduced. This difference in oxygen behavior can be attributed to the influence of mechanical stress in the near surface highly doped layer. The configuration of the mechanical stress field is different for the cases of As and Sb implantation, with tensile stress dominating for the latter. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The impact of electrical stimulation techniques on behavior
Authors: Antal Andrea , Ambrus Géza Gergely , Chaieb Leila 
Published: September 2014

Low‐intensity transcranial electrical stimulation (tES) methods are a group of noninvasive brain stimulation techniques, whereby currents are applied with intensities typically ranging between 1 and 2 mA, through the human scalp. These techniques have been shown to induce changes in cortical excitability and activity during and after the stimulation in a reversible manner. They include transcranial direct current simulation (tDCS), transcranial alternating current simulation (tACS), and transcranial random noise stimulation (tRNS). Currently, an increasing number of studies have been published regarding the effects of tES on cognitive performance and behavior. Processes of learning and increases in cognitive performance are accompanied by changes in cortical plasticity. tES can impact upon these processes and is able to affect task execution. Many studies have been based on the accepted idea that by increasing cortical excitability (e.g., by applying anodal tDCS) or coherence of oscillatory activity (e.g., by applying tACS) an increase in performance should be detected; however, a number of studies now suggest that the basic knowledge of the mechanisms of action is insufficient to predict the outcome of applied stimulation on the execution of a cognitive or behavioral task, and so far no standard paradigms for increasing cortical plasticity changes during learning or cognitive tasks have been established. The aim of this review is to summarize recent findings with regard to the effects of tES on behavior concentrating on the motor and visual areas. WIREs Cogn Sci 2014, 5:649–659. doi: 10.1002/wcs.1319This article is categorized under:

Psychology > Memory
Psychology > Motor Skill and Performance
Neuroscience > Cognition
Hormonal therapy for non‐obstructive azoospermia: basic and clinical perspectives
Authors: Shiraishi Koji 
Published: September 2014

AbstractMicrodissection testicular sperm extraction (micro‐TESE) combined with intracytoplasmic sperm injection is a standard therapeutic option for patients with non‐obstructive azoospermia (NOA). Hormonal treatment has been believed to be ineffective for NOA because of high gonadotropin levels; however, several studies have stimulated spermatogenesis before or after micro‐TESE by using anti‐estrogens, aromatase inhibitors, and gonadotropins. These results remain controversial; however, it is obvious that some of the patients showed a distinct improvement in sperm retrieval by micro‐TESE, and sperm was observed in the ejaculates of a small number of NOA patients. One potential way to improve spermatogenesis is by optimizing the intratesticular testosterone (ITT) levels. ITT has been shown to be increased after hCG‐based hormonal therapy. The androgen receptor that is located on Sertoli cells plays a major role in spermatogenesis, and other hormonal and non‐hormonal factors may also be involved. Before establishing a new hormonal treatment protocol to stimulate spermatogenesis in NOA patients, further basic investigations regarding the pathophysiology of spermatogenic impairment are needed. Gaining a better understanding of this issue will allow us to tailor a specific treatment for each patient.
Influence of microglial activation on neuronal function in Alzheimer's and Parkinson's disease dementia
Authors: Fan Zhen , Aman Yahyah , Ahmed Imtiaz , Chetelat Gaël , Landeau Brigitte , Ray Chaudhuri K. , Brooks David J. , Edison Paul 
Published: September 2014

AbstractBackgroundAlzheimer's disease (AD) and Parkinson's disease (PD) are the two common neurodegenerative diseases characterized by progressive neuronal dysfunction in the presence of pathological microglial activation.Methods10 AD, 10 mild cognitive impairment (MCI), 11 PD dementia (PDD), and 16 controls underwent magnetic resonance imaging, [11C](R)PK11195 (1‐[2‐chlorophenyl]‐N‐methyl‐N‐[1‐methyl‐propyl]‐3‐isoquinoline carboxamide), [11C]PIB (11C‐Pittsburgh compound B), [18F]FDG‐PET (18F‐2‐fluoro‐2‐deoxyglucose positron emission tomography) scans. Parametric images were interrogated using region of interest (ROI), biological parametric mapping (BPM) and statistical parametric mapping analysis, and neuropsychometric tests.ResultsUsing BPM analysis, AD, MCI, and PDD subjects demonstrated significant correlation between increased microglial activation and reduced glucose metabolism (rCMRGlc). AD and MCI subjects also showed significant positive correlation between amyloid and microglial activation. Levels of cortical microglial activation were negatively correlated with Mini‐Mental State Examination in both AD and PDD.ConclusionThe significant inverse correlations between cortical levels of microglial activation and rCMRGlc in AD and PDD suggest cortical neuroinflammation may drive neuronal dysfunction in these dementias.
Effect of temperature on the phenology ofChilo partellus(Swinhoe) (Lepidoptera, Crambidae); simulation and visualization of the potential future distribution ofC. partellusin Africa under warmer temperatures through the development of life-table parameters
Authors: Khadioli N. , Tonnang Z.E.H. , Muchugu E. , Ong'amo G. , Achia T. , Kipchirchir I. , Kroschel J. , Le Ru B. 
Published: September 2014

AbstractMaize (Zea mays) is a major staple food in Africa. However, maize production is severely reduced by damage caused by feeding lepidopteran pests. In East and Southern Africa,Chilo partellusis one of the most damaging cereal stem borers mainly found in the warmer lowland areas. In this study, it was hypothesized that the future distribution and abundance ofC. partellusmay be affected greatly by the current global warming. The temperature-dependent population growth potential ofC. partelluswas studied on artificial diet under laboratory conditions at six constant temperatures (15, 18, 20, 25, 28, 30, 32 and 35 °C), relative humidity of 75±5% and a photoperiod of L12:L12 h. Several non-linear models were fitted to the data to model development time, mortality and reproduction of the insect species. Cohort updating algorithm and rate summation approach were stochastically used for simulating age and stage structure populations and generate life-table parameters. For spatial analysis of the pest risk, three generic risk indices (index of establishment, generation number and activity index) were visualized in the geographical information system component of the advanced Insect Life Cycle modeling (ILCYM) software. To predict the future distribution ofC. partelluswe used the climate change scenario A1B obtained from WorldClim and CCAFS databases. The maps were compared with available data on the current distribution ofC. partellusin Kenya. The results show that the development times of the different stages decreased with increasing temperatures ranging from 18 to 35 °C; at the extreme temperatures, 15 and 38 °C, no egg could hatch and no larvae completed development. The study concludes thatC. partellusmay potentially expands its range into higher altitude areas, highland tropics and moist transitional regions, with the highest maize potential where the species has not been recorded yet. This has serious implication in terms of food security since these areas produce approximately 80% of the total maize in East Africa.
Does HMGB1 predict occult neck lymph node metastasis in early tongue carcinoma? A case–control study of 26 patients
Authors: Hanakawa H , Orita Y , Sato Y , Takeuchi M , Takao S , Ohno K , Kohno T , Iwaki N , Marunaka H , Tamamura R , Nishibori M , Nagatsuka H , Nishizaki K , Yoshino T 
Published: September 2014

AbstractObjective:This study examined whether the occurrence of late neck metastasis in early tongue squamous cell carcinoma can be predicted by evaluating HMGB1 (high mobility group box 1) expression in the primary lesion.Methods:A case–control study was conducted. The cases comprised 10 patients with late neck metastasis. The controls consisted of 16 patients without recurrence. All were examined immunohistochemically for HMGB1 protein expression. The odds ratio for late neck metastasis in relation to HMGB1 was estimated.Results:Results for HMGB1 were dichotomised into positive staining scores (score, 5–7) and negative scores (0–4). Six cases (60 per cent) and four controls (25 per cent) were HMGB1-positive. Although no significant result was seen, compared with HMGB1-negative patients the odds ratio for late neck metastasis in HMGB1-positive patients was 3.8 (95 per cent confidence interval, 0.6–26.5) after adjusting for other factors.Conclusion:In the present study, immunohistochemical study of HMGB1 in early tongue squamous cell carcinoma did not appear to be very useful for predicting occult neck metastasis. Further study is necessary to clarify the relationship between HMGB1 expression and late neck metastasis in early tongue squamous cell carcinoma.
Computational Study of In-Plane Phonon Transport in Si Thin Films
Authors: Wang Xinjiang , Huang Baoling 
Published: September 2014

AbstractWe have systematically investigated the in-plane thermal transport in Si thin films using an approach based on the first-principles calculations and lattice dynamics. The effects of phonon mode depletion induced by the phonon confinement and the corresponding variation in interphonon scattering, which may be important for the thermal conductivities of ultra-thin films but are often neglected in precedent studies, are considered in this study. The in-plane thermal conductivities of Si thin films with different thicknesses have been predicted over a temperature range from 80 K to 800 K and excellent agreements with experimental results are found. The validities of adopting the bulk phonon properties and gray approximation of surface specularity in thin film studies have been clarified. It is found that in ultra-thin films, while the phonon depletion will reduce the thermal conductivity of Si thin films, its effect is largely offset by the reduction in the interphonon scattering rate. The contributions of different phonon modes to the thermal transport and isotope effects in Si films with different thicknesses under various temperatures are also analyzed.
Hepatic serum- and glucocorticoid-regulated protein kinase 1 (SGK1) regulates insulin sensitivity in mice via extracellular-signal-regulated kinase 1/2 (ERK1/2)
Authors: Liu Hao , Yu Junjie , Xia Tingting , Xiao Yuzhong , Zhang Qian , Liu Bin , Guo Yajie , Deng Jiali , Deng Yalan , Chen Shanghai , Naray-Fejes-Toth Aniko , Fejes-Toth Geza , Guo Feifan 
Published: September 2014

Insulin resistance is a major hallmark of metabolic syndromes, including Type 2 diabetes. Although numerous functions of SGK1 (serum- and glucocorticoid-regulated kinase 1) have been identified, a direct effect of SGK1 on insulin sensitivity has not been previously reported. In the present study, we generated liver-specific SGK1-knockout mice and found that these mice developed glucose intolerance and insulin resistance. We also found that insulin signalling is enhanced or impaired in Hep1-6 cells infected with adenoviruses expressing SGK1 (Ad-SGK1) or shRNA directed against the coding region of SGK1 (Ad-shSGK1) respectively. In addition, we determined that SGK1 inhibits ERK1/2 (extracellular-signal-regulated kinase 1/2) activity in liver and Ad-shERK1/2-mediated inhibition of ERK1/2 reverses the attenuated insulin sensitivity in Ad-shSGK1 mice. Finally, we found that SGK1 functions are compromised under insulin-resistant conditions and overexpression of SGK1 by Ad-SGK1 significantly ameliorates insulin resistance in both glucosamine-treated HepG2 cells and livers of db/db mice, a genetic model of insulin resistance.
Angiotensin-(1–7) decreases skeletal muscle atrophy induced by angiotensin II through a Mas receptor-dependent mechanism
Authors: Cisternas Franco , Morales María Gabriela , Meneses Carla , Simon Felipe , Brandan Enrique , Abrigo Johanna , Vazquez Yaneisi , Cabello-Verrugio Claudio 
Published: September 2014

Skeletal muscle atrophy is a pathological condition characterized by the loss of strength and muscle mass, an increase in myosin heavy chain (MHC) degradation and increase in the expression of two muscle-specific ubiquitin ligases: atrogin-1 and MuRF-1. Angiotensin II (AngII) induces muscle atrophy. Angiotensin-(1–7) [Ang-(1–7)], through its receptor Mas, produces the opposite effects than AngII. We assessed the effects of Ang-(1–7) on the skeletal muscle atrophy induced by AngII. Our results show that Ang-(1–7), through Mas, prevents the effects induced by AngII in muscle gastrocnemius: the decrease in the fibre diameter, muscle strength and MHC levels and the increase in atrogin-1 and MuRF-1. Ang-(1–7) also induces AKT phosphorylation. In addition, our analysis in vitro using C2C12 myotubes shows that Ang-(1–7), through a mechanism dependent on Mas, prevents the decrease in the levels of MHC and the increase in the expression of the atrogin-1 and MuRF-1, both induced by AngII. Ang-(1–7) induces AKT phosphorylation in myotubes; additionally, we demonstrated that the inhibition of AKT with MK-2206 decreases the anti-atrophic effects of Ang-(1–7). Thus, we demonstrate for the first time that Ang-(1–7) counteracts the skeletal muscle atrophy induced by AngII through a mechanism dependent on the Mas receptor, which involves AKT activity. Our study indicates that Ang-(1–7) is novel molecule with a potential therapeutical use to improve muscle wasting associated, at least, with pathologies that present high levels of AngII.
Optimal design of polymer‐based microneedle for improved collection of whole blood from human fingers
Authors: Le Thanh Hoa , Le The Hai , Nguyen Vy , Tran‐Minh Nhut , Wang Kaiying , Karlsen Frank 
Published: September 2014

A highly applicable theoretical model and a simple, inexpensive mould‐based method is introduced to design and fabricate the pyramid‐shaped SU‐8 microneedle. The main purpose is to be able to extract blood at point‐of‐care sites from up to 80% of typical nurse‐home patients with a disorder of blood circulation in fingers and toes (Raynaud's phenomenon). Geometry optimisation was conducted based on the study of fracture force, which can be accurately predicted by the proposed theoretical model. The accuracy of the proposed theoretical model was confirmed by the finite element study and practical measurement. For practical verification, measurement of fracture force was conducted on fabricated SU‐8 microneedles, including a 1470 µm‐tall pyramid‐shaped microneedle and a 1515 µm‐tall traditional‐shaped microneedle. The measurement results confirmed the improved strength of the proposed pyramid‐shaped microneedle, especially of the pyramidal tips, which can exhibit significantly higher applied force with 2.82 N compared with the 0.51 N bevel tip. Practical tests of skin penetrability on human fingers showed that the microneedles fabricated with the proposed geometry may be sharp and strong enough to safely puncture human skin and long enough to reach the blood vessels.
Microresonant accelerometer composed of silicon substrate and quartz double‐ended tuning fork with temperature isolator
Authors: Li Cun , Zhao Yulong , Cheng Rongjun , Yu Zhongliang 
Published: September 2014

A microresonant accelerometer which consists of silicon substrate and a quartz double‐ended tuning fork (DETF) is described. A temperature isolator structure on the silicon substrate is designed to decrease the influence of thermal stress on the DETF's tines. Two stiff ends of the quartz DETF are mounted on the proof mass and temperature isolator, respectively. When acceleration is applied, the proof mass will move, inducing the variation of axial stress on the DETF's tines. The resonance frequency of the DETF's tines will change corresponding to the stress, so acceleration can be measured. The DETF is excited by the inherent piezoelectric property of quartz based on the anti‐phase in‐plane bending model. Both the silicon substrate and the DETF are fabricated by micromachining. The sensor is analysed by finite‐element simulation. According to the simulation, the temperature isolator decreases thermal stress by 30.2%. Experimental results show that the resonance frequency of the sensor is 35.2563 kHz and the sensitivity is 8.55 Hz/g, which is in good agreement with analytical calculation.
Sequential switching of binding partners on PCNA during in vitro Okazaki fragment maturation
Authors: Dovrat Daniel , Stodola Joseph L. , Burgers Peter M. J. , Aharoni Amir 
Published: September 2014

Significance
Proliferating cell nuclear antigen (PCNA) is a homotrimeric DNA sliding clamp that coordinates multiple DNA replication and repair processes by orchestrating the activity of various essential proteins. PCNA can bind up to three partners simultaneously, but despite extensive research, the functional significance of PCNA's trimeric structure remains unclear. We developed a novel approach for the generation of PCNA heterotrimers that contain both wild-type and mutant monomers. Using these heterotrimers, we show that PCNA can efficiently coordinate the activities of the three enzymes involved in Okazaki fragment maturation without binding them simultaneously. In contrast to the previously suggested “toolbelt” model for PCNA function, our results demonstrate sequential binding and release of partners on the PCNA trimer during complex biological processes.
Understanding the frustration arising from the competition between function, misfolding, and aggregation in a globular protein
Authors: Gianni Stefano , Camilloni Carlo , Giri Rajanish , Toto Angelo , Bonetti Daniela , Morrone Angela , Sormanni Pietro , Brunori Maurizio , Vendruscolo Michele 
Published: September 2014

Significance
The amino acid sequence of a protein encodes a wide range of different properties, including function, folding, and avoidance of aggregation. The resulting requirements on the sequence may be in conflict with each other, thus creating the possibility of misfolding and dysfunction. To investigate possible mechanisms whereby such unwanted outcomes can be prevented, we study the folding process of frataxin, a protein whose aberrant folding is associated with Friedreich’s ataxia. Our results indicate that the regions prone to misfolding are highly protected against aggregation along the folding pathway of this protein.
Onecut1 and Onecut2 redundantly regulate early retinal cell fates during development
Authors: Sapkota Darshan , Chintala Hemabindu , Wu Fuguo , Fliesler Steven J. , Hu Zihua , Mu Xiuqian 
Published: September 2014

Significance
We show that the onecut transcription factors, Onecut1 and Onecut2, redundantly regulate the formation of all four early-born retinal cell types, namely horizontal cells, ganglion cells, cones, and amacrine cells, and prevent precocious formation of the late retinal cell type, rods. Expression profiling suggests these two factors regulate a shared set of downstream genes to maintain competence for the early retinal cell types and to regulate generation of various subtypes of retinal ganglion cells. This study lays the foundation for further examination of how onecut factors regulate cell differentiation in the retina, as well as in the central nervous system in general.
Landscape and flux reveal a new global view and physical quantification of mammalian cell cycle
Authors: Li Chunhe , Wang Jin 
Published: September 2014

Significance
Understanding the mechanisms of the cell cycle remains challenging. The cell cycle is regulated by the underlying gene regulatory networks. We uncovered the underlying Mexican hat landscape of a mammalian cell cycle network. Three local basins of attraction along the cell cycle loop emerge, corresponding to three distinct cell cycle states: the G1, S/G2, and M phases. Two barriers along the loop characterize G1 and S/G2 checkpoints, respectively, of the cell cycle, which provide a physical explanation for cell cycle checkpoint mechanisms. The cell cycle is determined by two driving forces: curl flux and potential barriers. We uncovered the key gene regulations determining the progression of cell cycle, which can be used to guide the design of new anticancer tactics.
Selection of the lamprey VLRC antigen receptor repertoire
Authors: Holland Stephen J. , Gao Mingming , Hirano Masayuki , Iyer Lakshminarayan M. , Luo Ming , Schorpp Michael , Cooper Max D. , Aravind L. , Mariuzza Roy A. , Boehm Thomas 
Published: September 2014

Significance
The alternative adaptive immune system of jawless vertebrates is based on three types of variable lymphocyte receptors (VLRs) that are differentially expressed by distinct B- and T-like lymphocyte lineages. Like the antibodies and T-cell receptors of jawed vertebrates, the highly variable VLR antigen receptors are generated by combinatorial assembly. However, it is not known whether VLRs are subjected to selection to mitigate the detrimental effects of self-reactivity. Here, we identify signatures for selection of the VLRC receptors that are expressed by one of the T-cell lineages of lamprey; selection concerns the length of the receptor molecules and their N-terminal sequence diversity. These findings pave the way to identifying the mechanistic basis of selection.