First Experimental Demonstration of Gate-all-around III-V MOSFET by Top-down Approach

The first inversion-mode gate-all-around (GAA) III-V MOSFETs are experimentally demonstrated with a high mobility In0.53Ga0.47As channel and atomic-layer-deposited (ALD) Al2O3/WN gate stacks by a top-down approach. A well-controlled InGaAs nanowire release process and a novel ALD high-k/metal gate process has been developed to enable the fabrication of III-V GAA MOSFETs. Well-behaved on-state and off-state performance has been achieved with channel length (Lch) down to 50nm. A detailed scaling metrics study (S.S., DIBL, VT) with Lch of 50nm - 110nm and fin width (WFin) of 30nm - 50nm are carried out, showing the immunity to short channel effects with the advanced 3D structure. The GAA structure has provided a viable path towards ultimate scaling of III-V MOSFETs.Comment: IEEE IEDM 2011 pp. 769-772; Structures are valuable for low-dimensional physics stud

Seismic Response Calculation of Saturated Soft Soil

In this paper, Shanghai saturated soft soil is modeled as a two-phase porous media system consisting of solid and fluid phases. On the basis of resonant column test and dynamic triaxial test data of Shanghai saturated soft soil, the dynamic calculation model including a set of relationships of stress, strain, and pore water pressure and earthquake subsidence is developed to compute the seismic response of soil. The procedure to identify soil constants for the dynamic calculation model is also reported in detail. Subsequently, a dynamic effective stress analysis with the finite element method has been recommended to predict the seismic response of soil. Finally, the developed dynamic calculation model together with the dynamic effective stress analysis is utilized to predict the seismic response of Shanghai soil strata through the finite element method and some valuable conclusions are obtained from the results

Meta-evaluation of online and offline web search evaluation metrics

As in most information retrieval (IR) studies, evaluation plays an essential part in Web search research. Both offline and online evaluation metrics are adopted in measuring the performance of search engines. Offline metrics are usually based on relevance judgments of query-document pairs from assessors while online metrics exploit the user behavior data, such as clicks, collected from search engines to compare search algorithms. Although both types of IR evaluation metrics have achieved success, to what extent can they predict user satisfaction still remains under-investigated. To shed light on this research question, we meta-evaluate a series of existing online and offline metrics to study how well they infer actual search user satisfaction in different search scenarios. We find that both types of evaluation metrics significantly correlate with user satisfaction while they reflect satisfaction from different perspectives for different search tasks. Offline metrics better align with user satisfaction in homogeneous search (i.e. ten blue links) whereas online metrics outperform when vertical results are federated. Finally, we also propose to incorporate mouse hover information into existing online evaluation metrics, and empirically show that they better align with search user satisfaction than click-based online metrics

Learning Harmonic Molecular Representations on Riemannian Manifold

Molecular representation learning plays a crucial role in AI-assisted drug discovery research. Encoding 3D molecular structures through Euclidean neural networks has become the prevailing method in the geometric deep learning community. However, the equivariance constraints and message passing in Euclidean space may limit the network expressive power. In this work, we propose a Harmonic Molecular Representation learning (HMR) framework, which represents a molecule using the Laplace-Beltrami eigenfunctions of its molecular surface. HMR offers a multi-resolution representation of molecular geometric and chemical features on 2D Riemannian manifold. We also introduce a harmonic message passing method to realize efficient spectral message passing over the surface manifold for better molecular encoding. Our proposed method shows comparable predictive power to current models in small molecule property prediction, and outperforms the state-of-the-art deep learning models for ligand-binding protein pocket classification and the rigid protein docking challenge, demonstrating its versatility in molecular representation learning.Comment: 25 pages including Appendi

Atomic layer epitaxy of rare earth oxide films on GaAs(111)A and their device properties

The aggressive scaling of MOSFETs has created interest in using high-mobility III-V channel materials to replace traditional strained Si. However, it has been challenging to form high- $\kappa$ dielectrics that can passivate III-V surfaces with a low interface state density (Dit). We deposited $LaLuO_3$ high- dielectric layer by ALD on sulfur-passivated GaAs substrates. The precursors lanthanum tris(N,N'-diisopropylformamidinate), and lutetium tris(N,N'-diethylformamidinate) reacted with water vapor at $350^oC$. The compositional ratio of La:Lu was about 1:1 by using one cycle of $La_2O_3$ followed by one cycle of $Lu_2O_3$ in one complete cycle of $LaLuO_3$. Both high-resolution XRD analysis and TEM showed that ALD $LaLuO_3$ formed epitaxially on GaAs(111)A substrates, as shown in Figures 1 and 2, respectively. The epitaxial layer exhibited a cubic structure with a lattice constant smaller than GaAs by 3.8%. The $LaLuO_3$ film had a high degree of crystalline perfection and was relaxed and not strained. Electrical characterizations showed the measured dielectric constant of around 30, which is close to its bulk crystalline value. The interface had a low interface state density $(D_{it})$ of $\sim 7×10^{11} cm^{-2}eV^{-1}$. The amount of lattice mismatch can be engineered by choosing various rare-earth oxides. ALD La2O3 formed cube-on-cube epitaxy on GaAs(111)A with a lattice constant just +0.9% larger than that of the substrate. The mismatch can be reduced to zero by adding some $Y_2O_3$ to the $La_2O_3$, using yttrium tris(N,N'-diisopropylactamidinate)/$H_2O$ cycles. Perfect zero-mismatched epitaxy was achieved on GaAs(111)A by depositing $La_{1.7}Y_{0.3}O_3$, as shown in Figure 3. The effects of mismatch on the electrical properties of eip-$LaYO_3$ on GaAs(111)A were studied. These results suggest that atomic layer epitaxy of rare-earth oxides/GaAs(111)A is a promising structure for future generations of high-power/high-frequency analog devices or high-speed logic devices.Chemistry and Chemical Biolog

Światowa produktywność badań w dziedzinie endokrynologii i metabolizmu — analiza bibliometryczna

  Introduction: Recently, significant contributions to the study of endocrinology and metabolism have been made. The national contribution, however, has not been reported. The aim of this study was to assess national efforts in the field of endocrinology and metabolism. Material and methods: A Web of Science search was performed using subject categories “endocrinology & metabolism” to identify articles published from 2010 to 2014. The total and per capita numbers of articles and citations were analysed for different countries. Results: A total of 79,394 articles were published on endocrinology and metabolism from 2010 to 2014. Most were published in North America, East Asia, and Europe. The majority (82.28%) were reported by authors in high-income countries, 17.64% were published in middle-income countries, and only 0.08% were published in low-income countries. Authors in the United States published the most articles (27.38%), followed by China (7.22%), Italy (5.70%), the United Kingdom (5.6%), and Japan (5.54%). Articles published by authors in the United States had the most citations (260,934). A positive correlation was found between the number of publications and population/gross domestic product (GDP; p < 0.01). When normalised to population size, the ranking for the most publications was Denmark, Sweden, and the Netherlands; when normalised to GDP, the ranking was Denmark, Greece, and the Netherlands. Conclusions: The majority of endocrinology and metabolism articles were published by authors from high-income countries with few from low-income countries. The United States was the most productive country. However, when population size and GDP were considered, some European countries were ranked higher. (Endokrynol Pol 2015; 66 (5): 434–442)    Wstęp: Ostatnio pojawiło się wiele znaczących publikacji na temat badań z dziedziny endokrynologii i metabolizmu. Narodowy wkład na tym polu został jednak pominięty. Celem niniejszego badania była ocena krajowych badań w dziedzinie endokrynologii i metabolizmu. Materiał i metody: Wyszukiwanie za pomocą Web of Science przeprowadzono z wykorzystaniem kategorii podmiotowych „endokrynologia i metabolizm”, aby zidentyfikować artykuły opublikowane w latach 2010–2014. Analizie poddano łączną liczbę artykułów i cytowań, a także ich liczbę przypadającą na osobę w odniesieniu do różnych krajów. Wyniki: W latach 2010–2014 opublikowano łącznie 79 394 artykułów na temat endokrynologii i metabolizmu. Większość artykułów pochodziła z Ameryki Północnej, Azji Wschodniej i Europy. Większość artykułów (82,28%) napisali autorzy z krajów o wysokich dochodach, 17,64% opublikowano w krajach średnio zamożnych, a jedynie 0,08% artykułów opublikowano w krajach o niskich dochodach. Najwięcej artykułów publikowali autorzy ze Stanów Zjednoczonych (27,38%), następnie z Chin (7,22%), Włoch (5,70%), Wielkiej Brytanii (5,6%) i Japonii (5,54%). Prace publikowane przez amerykańskich autorów zawierały największą liczbę cytowań (260 934). Stwierdzono pozytywny związek między liczbą publikacji i populacją/produktem krajowym brutto (PKB; p < 0,01). Po unormalizowaniu do liczebności populacji, w rankingu krajów o najwyższej liczbie publikacji znalazły się Dania, Szwecja oraz Holandia. Gdy znormalizowano wyniki pod względem PKB, w rankingu znalazły się Dania, Grecja oraz Holandia. Wnioski: Większość artykułów z dziedziny endokrynologii i metabolizmu została opublikowana przez autorów z krajów o wysokich dochodach; w krajach o niskich dochodach ukazało się niewiele artykułów. Stany Zjednoczone wykazały największą produktywność, jednak kiedy brano pod uwagę liczebność populacji i PKB, niektóre kraje europejskie zajmowały wyższą pozycję. (Endokrynol Pol 2015; 66 (5): 434–442)

Sp1, Instead of AhR, Regulates the Basal Transcription of Porcine CYP1A1 at the Proximal Promoter

Pigs are commonly used as an animal model to evaluate the toxic effects of exogenous compounds. Cytochrome P450 1A1 (CYP1A1) metabolizes numerous exogenous compounds and is abundantly expressed in the liver, kidneys, and intestines. The high amino acid similarity between human and porcine CYP1A1 indicates that they probably have the same metabolic characteristics. Therefore, understanding the regulatory mechanism of CYP1A1 expression in pigs is particularly important for predicting the toxicology and metabolic kinetics of exogenous chemicals. Currently, the transcriptional regulation of porcine CYP1A1 has rarely been studied, especially regarding basal transcription. In this study, we first confirmed that the key regulatory elements of porcine CYP1A1 basal transactivation are in the proximal promoter region using promoter truncation analysis via a dual luciferase assay in a porcine kidney cell line LLC-PK1. Two overlapping cis-elements, the xenobiotic response element (XRE) and GC box, in this proximal region potentially play key roles in the basal transactivation of porcine CYP1A1. Furthermore, using electrophoretic mobility shift assay and chromatin immunoprecipitation, the GC box binding protein Sp1 was confirmed to bind to the proximal promoter of porcine CYP1A1, instead of AhR, the XRE binding protein. In LLC-PK1 cells, by knocking down either Sp1 or AhR, the expression of porcine CYP1A1 at the mRNA level and protein level was significantly downregulated, suggesting both proteins are important for porcine CYP1A1 expression. However, promoter activity analysis in LLC-PK1 cells treated with an AhR agonist and antagonist confirmed that AhR does not participate in the basal regulation of porcine CYP1A1 at the proximal promoter. In conclusion, our study revealed that the proximal promoter is the key regulatory region for porcine CYP1A1 basal expression. Although AhR plays an important role in the transactivation of porcine CYP1A1 expression, the key determinant transcription factor for its basal transactivation is Sp1 at the proximal promoter of porcine CYP1A1

The chemical profiling of Salvia plebeia during different growth periods and the biosynthesis of its main flavonoids ingredients

Salvia plebeia (Lamiaceae) is a valuable medicinal plant widely distributed across Asia and Oceania. However, the composition and accumulation patterns of its active ingredients in different organs during the growth and their biosynthetic mechanism remain unknown. Therefore, we conducted metabolite profiling, transcriptomic analysis, and biological functional verification to explore the distribution, accumulation, and biosynthesis mechanisms of flavonoids in S. plebeia. We identified 70 metabolites including 46 flavonoids, 16 phenolic acids, seven terpenoids, and one organic acid, of which 21 were previously unreported in S. plebeia. Combining metabolomic-transcriptomic analysis and biological functional verification, we identified the key genes involved in biosynthesis of its main active ingredients, hispidulin and homoplantaginin, including SpPAL, SpC4H, Sp4CL2, Sp4CL5, SpCHS1, SpCHI, SpFNS, SpF6H1, SpF6OMT1, SpF6OMT2, SpUGT1, SpUGT2, and SpUGT3. Using the identified genes, we reconstructed the hispidulin and homoplantaginin biosynthesis pathways in Escherichia coli, and obtained a yield of 5.33 and 3.86 mg/L for hispidulin and homoplantaginin, respectively. Our findings provide valuable insights into the changes in chemical components in different organs of S. plebeia during different growth and harvest stages and establishes a foundation for identifying and synthesizing its active components

Plexin-B1 silencing inhibits ovarian cancer cell migration and invasion

BACKGROUND: Elevated Plexin-B1 expression has been found in diverse human cancers and in non-neoplastic tissues, and it mediates diverse biological and pathological activities. However, whether or not Plexin-B1 expression is involved in human ovarian tumors remains unclear. In the present study, Plexin-B1 expression was explored in benign and malignant human ovarian tumor tissues. In addition, the impact of Plexin-B1 expression on ovarian cancer cell proliferation, migration and invasion were investigated in vitro. METHODS: Plexin-B1 expression was analyzed in normal and benign ovarian tissues and serous ovarian tumors (both borderline and malignant) by immunohistochemical staining, as well as in four human ovarian cancer cell lines (A2780, C13*, SKOV3, and OV2008) by RT-PCR and western blot analyses. Furthermore, endogenous Plexin-B1 expression was suppressed by Plexin-B1 siRNA in SKOV3 cells, which overexpress Plexin-B1. Protein levels of Plexin-B1, AKT and AKT(Ser473 )were examined by western blot analysis. Cell proliferation, migration and invasion were measured with MTT, wound healing and boyden chamber assays, respectively, and the cytoskeleton was monitored via F-actin staining. RESULTS: Expression levels of Plexin-B1 protein were significantly higher in serous ovarian carcinomas than in normal ovaries or benign ovarian neoplasms, and in the former, Plexin-B1 expression was positively correlated with lymphatic metastasis, and the membrane and cytoplasm of cancer cells stained positively. SKOV3 cells displayed the highest Plexin-B1 expression at both the mRNA and protein levels among the four tested human ovarian cancer cell lines and was selected as a cell model for further in vitro experiments. Plexin-B1 siRNA significantly suppressed phosphorylation of AKT at Ser473 in SKOV3 cells, but it did not alter total AKT expression. In addition, silencing of Plexin-B1 in SKOV3 cells inhibited cell migration and invasion and reorganized the cytoskeleton, whereas cell proliferation was not affected. CONCLUSION: Plexin-B1 expression correlates with malignant phenotypes of serous ovarian tumors, probably via phosphorylation of AKT at Ser473, suggesting that Plexin-B1 might be a useful biomarker and/or a novel therapeutic target