bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase 1 trial of temsirolimus in combination with irinotecan and temozolomide in children, adolescents and young adults with relapsed or refractory solid tumors: A children's oncology group study
Authors: Bagatell Rochelle , Norris Robin , Ingle Ashish M. , Ahern Charlotte , Voss Stephan , Fox Elizabeth , Little Anthony R. , Weigel Brenda J. , Adamson Peter C. , Blaney Susan
Published: November 2013

Background

mTOR inhibitors have activity in pediatric tumor models. A phase I trial of the mTOR inhibitor temsirolimus (TEM) with irinotecan (IRN) and temozolomide (TMZ) was conducted in children with recurrent/refractory solid tumors, including central nervous system (CNS) tumors.

Methods

Escalating doses of intravenous (IV) TEM were administered on days 1 and 8 of 21‐day cycles. IRN (50 mg/m2/dose escalated to a maximum of 90 mg/m2/dose) and TMZ (100 mg/m2/dose escalated to a maximum of 150 mg/m2/dose) were administered orally (PO) on days 1–5. When maximum tolerated doses (MTD) were identified, TEM frequency was increased to weekly.

Results

Seventy‐one eligible pts (median age 10.9 years, range 1.0–21.5) with neuroblastoma (16), osteosarcoma (7), Ewing sarcoma (7), rhabdomyosarcoma (4), CNS (22) or other (15) tumors were enrolled. Dose‐limiting hyperlipidemia occurred in two patients receiving oral corticosteroids. The protocol was subsequently amended to preclude chronic steroid use. The MTD was identified as TEM 35 mg/m2 IV weekly, with IRN 90 mg/m2 and TMZ 125 mg/m2 PO on days 1–5. At higher dose levels, elevated serum alanine aminotransferase and triglycerides, anorexia, and thrombocytopenia were dose limiting. Additional ≥grade 3 regimen‐related toxicities included leukopenia, neutropenia, lymphopenia, anemia, and nausea/vomiting. Six patients had objective responses confirmed by central review; three of these had sustained responses through ≥14 cycles of therapy.

Conclusion

The combination of TEM (35 mg/m2/dose IV weekly), IRN (90 mg/m2/dose days 1–5) and TMZ (125 mg/m2/dose days 1–5) administered PO every 21 days is well tolerated in children. Phase 2 trials of this combination are ongoing. Pediatr Blood Cancer 2014;61:833–839. © 2013 Wiley Periodicals, Inc.
Shear strengthening of reinforced concrete T‐beams with fully or partially bonded fibre‐reinforced polymer composites
Authors: Ozden Sevket , Atalay Hilal M. , Akpinar Erkan , Erdogan Hakan , Vulaş Yılmaz Zafer
Published: November 2013

A series of 10 reinforced concrete T‐beams, designed deficient in shear, were tested in order to investigate the shear performance achieved through externally applied U‐shaped FRP composite strips. Key variables of the study were: type of FRP composite, type of surface bonding and type of end anchorage for the strips. Carbon fibre‐reinforced polymer (CFRP), glass fibre‐reinforced polymer (GFRP) and high modulus of elasticity carbon fibre‐reinforced polymer (Hi‐CFRP) strips were the special composite types with different elastic moduli, full or partial bonding of the strips to the beam surface were the variables for the type of surface bonding. All partially bonded FRP strips were free from surface bonding, whereas epoxy‐bonded FRP anchors were used at their ends close to the slab‐to‐beam connection. Those strips with full surface bonding have either epoxy‐bonded FRP anchors at their ends or the strip ends were without anchorage. The test results revealed that shear‐deficient beams may well be strengthened by the externally applied FRP strips. However, the level of strength enhancement and the failure pattern is closely influenced by the composite's elastic modulus, the type of surface bonding and the type of end anchorage for the FRP strip itself. The enhancement of the Hi‐CFRP strips did not live up to expectations. The use of unbonded FRP for shear strengthening yielded promising results.
Transvaginal sonographic features of perineal masses in the female lower urogenital tract: a retrospective study of 71 patients
Authors: Wang X. , Yang H. , Zhang H. , Shi T. , Ren W.
Published: November 2013

Objectives

To assess the transvaginal ultrasonographic features of perineal masses in the lower urogenital tract in a cohort of 71 women.

Methods

Seventy‐one women with perineal masses were referred consecutively for transvaginal ultrasonography. Two‐dimensional (2D) ultrasound was used to scan the pelvic floor, including the urethra, vagina and rectum, and identify any possible areas of interest. A static three‐dimensional (3D) sonographic reconstruction of the pelvic anatomy was created to further delineate the relation of the lesions with their neighboring structures. Ultrasound results were compared retrospectively with surgical pathology outcome when possible.

Results

Seventy‐nine cystic, cystic‐solid or solid masses were detected on transvaginal 2D ultrasonography in the 71 women: in 44 patients, 47 anechoic cystic masses were identified and diagnosed as vaginal wall cysts; in 19 patients, 23 hyperechoic cystic masses were diagnosed as vaginal epidermoid cysts; in each of two patients, a hypoechoic cystic‐solid mass showing blood‐flow signals on color Doppler imaging was diagnosed as urogenital angiomyofibroblastoma; in each of three patients, a hypoechoic cyst was diagnosed as urethral diverticulum; and in three patients with a known history of gynecological malignancy, solid heterogeneous masses with blood flow signals on color Doppler imaging were diagnosed as metastatic cancer. In all patients, 3D ultrasonography delineated the anatomical relationship of these masses to the vagina, urethra and rectum.

Conclusions

Transvaginal 2D and 3D ultrasonography is an accurate, non‐invasive, cost‐effective diagnostic modality for the delineation of congenital, septic and neoplastic lower urogenital tract perineal masses in women. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Of plasticity and specificity: dialectics of the microenvironment and macroenvironment and the organ phenotype
Authors: Bhat Ramray , Bissell Mina J.
Published: November 2013

The study of biological form and how it arises is the domain of the developmental biologists; but once the form is achieved, the organ poses a fascinating conundrum for all the life scientists: how are form and function maintained in adult organs throughout most of the life of the organism? That they do appears to contradict the inherently plastic nature of organogenesis during development. How do cells with the same genetic information arrive at, and maintain such different architectures and functions, and how do they keep remembering that they are different from each other? It is now clear that narratives based solely on genes and an irreversible regulatory dynamics cannot answer these questions satisfactorily, and the concept of microenvironmental signaling needs to be added to the equation. During development, cells rearrange and differentiate in response to diffusive morphogens, juxtacrine signals, and the extracellular matrix (ECM). These components, which constitute the modular microenvironment, are sensitive to cues from other tissues and organs of the developing embryo as well as from the external macroenvironment. On the other hand, once the organ is formed, these modular constituents integrate and constrain the organ architecture, which ensures structural and functional homeostasis and therefore, organ specificity. We argue here that a corollary of the above is that once the organ architecture is compromised in adults by mutations or by changes in the microenvironment such as aging or inflammation, that organ becomes subjected to the developmental and embryonic circuits in search of a new identity. But since the microenvironment is no longer embryonic, the confusion leads to cancer: hence as we have argued, tumors become new evolutionary organs perhaps in search of an elusive homeostasis. WIREs Dev Biol 2014, 3:147–163. doi: 10.1002/wdev.130

This article is categorized under:

Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells

Gene Expression and Transcriptional Hierarchies > Cellular Differentiation

Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms

Comparative Development and Evolution > Regulation of Organ Diversity
On the supersymmetric completion of R + R
2 gravity and cosmology
Authors: Ferrara Sergio , Kallosh Renata , Van Proeyen Antoine
Published: November 2013

Abstract

We revisit and clarify the supersymmetric versions of R + R
2 gravity, in view of the renewed interest to these models in cosmology. We emphasize that the content of the dual standard supergravity theory in the old minimal formulation necessarily includes two massive chiral multiplets, that we call the inflaton and the goldstino. We point out that the presence of these multiplets is model independent in the old minimal formulation and therefore any theory that contains a single chiral multiplet fails to be a supersymmetric generalization of the R + R
2 gravity. The supergravity interactions of the two chiral multiplets are encoded in a superpotential mass term and an arbitrary Kähler potential for the goldstino multiplet. The implication for cosmology of the supersymmetric R + R
2 gravity is also discussed.
Mimetic dark matter
Authors: Chamseddine Ali H. , Mukhanov Viatcheslav
Published: November 2013

Abstract

We modify Einstein’s theory of gravity, isolating the conformal degree of freedom in a covariant way. This is done by introducing a physical metric defined in terms of an auxiliary metric and a scalar field appearing through its first derivatives. The resulting equations of motion split into a traceless equation obtained through variation with respect to the auxiliary metric and an additional differential equation for the trace part. As a result the conformal degree of freedom becomes dynamical even in the absence of matter. We show that this extra degree of freedom can mimic cold dark matter.
Is Intraoperative Calcitonin Monitoring Useful to Modulate the Extension of Neck Dissection in Patients With Medullary Thyroid Carcinoma?
Authors: De Crea Carmela , Raffaelli Marco , Milano Valentina , Carrozza Cinzia , Zuppi Cecilia , Bellantone Rocco , Lombardi Celestino P.
Published: November 2013

Background

The extension of the compartment‐oriented neck dissection at primary surgery in medullary thyroid carcinoma (MTC) is controversial. Because a <50 % decrease in intraoperative calcitonin levels (IO‐CT) after total thyroidectomy plus central neck dissection (TT‐CND) has been associated with residual disease, IO‐CT monitoring has been proposed to predict the completeness of surgery. The goal of the present prospective study was to verify the accuracy of IO‐CT monitoring.

Methods

All patients scheduled for primary surgery for suspected or proven MTC between November 2010 and January 2013 were included. Calcitonin was measured pre‐incision (basal level), after tumor manipulation, at the time TT‐CND was accomplished (ablation level), 10 and 30 min after ablation. A decrease >50 % with respect to the highest IO‐CT level 30 min after ablation was considered predictive of cure.

Results

Twenty‐six patients were included, and IO‐CT monitoring identified 18 of 23 cured patients (true negative results) and 2 of 3 patients with persistent disease (true positive result). In 5 patients with normal basal and stimulated postoperative calcitonin levels, a decrease <50 % was observed (false positive results). In one of three patients with persistent disease a >50 % decrease in IO‐CT was observed (false negative results). Specificity, sensitivity, and accuracy of IO‐CT were 78.2, 66.6, and 76.9 %, respectively.

Conclusions

Intraoperative calcitonin monitoring is not highly accurate in predicting the completeness of surgical resection. In the present series, relying on IO‐CT would result in limited resection in about one third of the patients with residual neck disease and in unnecessary lateral neck dissection in about 20 % of the cured patients.
Optimal Timing of Surgery for Differentiated Thyroid Cancer in Pregnant Women
Authors: Uruno Takashi , Shibuya Hiroshi , Kitagawa Wataru , Nagahama Mitsuji , Sugino Kiminori , Ito Koichi
Published: November 2013

Background

Differentiated thyroid cancer (DTC) is the second most common cancer diagnosed in pregnant women, but there is no consensus as to whether surgery should be performed during pregnancy or after delivery.

Methods

We retrospectively reviewed the records of 45 patients with DTC operated on during pregnancy or within 1 year after delivery, and we compared the clinicopathological features and outcomes of the patients operated during pregnancy (group A, n = 24) and the patients operated after delivery (group B, n = 21).

Results

All 45 patients were histologically diagnosed with well‐differentiated papillary thyroid cancer. Nineteen (79 %) of the 24 patients in group A underwent thyroidectomy during the second trimester. No complications associated with surgery or general anesthesia were reported in either group. There were no significant differences between the two groups in terms of age, tumor size, incidence of lymph node metastasis, or incidence of extrathyroidal extension. No distant metastases were detected in any of the patients. Two small for date infants (8.3 %) and 2 heavy for date infants (8.3 %) were delivered in group A, but only 1 small for date infant (4.7 %) was delivered in group B. There were no miscarriages, and none of the infants in either group had birth defects. Because 3 patients in group A and 1 patient in group B experienced a local recurrence, salvage surgeries were performed.

Conclusions

Although thyroid surgery was performed safely in the second trimester, surgery after delivery was also acceptable. Surgery after delivery is recommended for most patients with non‐aggressive DTC.
Molecular mapping of a stripe rust resistance gene in wheat cultivar Wuhan 2
Authors: Zhou X. L. , Han D. J. , Gou H. L. , Wang Q. L. , Zeng Q. D. , Yuan F. P. , Zhan G. M. , Huang L. L. , Kang Z. S.
Published: November 2013

Stripe rust (or yellow rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive diseases of wheat worldwide. Growing resistant cultivars is the best approach to control the disease. To identify and map genes for stripe rust resistance in wheat cultivar ‘Wuhan 2', an F2 population was developed from a cross between the cultivar and susceptible cultivar Mingxian 169. The parents, 179 F2 plants and their derived F2:3 lines were evaluated for responses to Chinese races CYR30 and CYR31 of the pathogen in a greenhouse. A recessive gene for resistance was identified. DNA bulked segregant analysis was applied and resistance gene analog polymorphism (RGAP) and simple sequence repeat (SSR) techniques were used to identify molecular markers linked to the resistance gene. A genetic map consisting of five RGAP and six SSR markers was constructed. The recessive gene, designated Yrwh2, was located on the short arm of chromosome 3B and flanked by SSR markers Xwmc540 and Xgwm566 at 5.9 and 10.0 cM, respectively. The chromosomal location of the resistance gene and its close marker suggest that the locus is different from previously reported stripe rust resistance genes Yr30, QYr.ucw-3BS, Yrns-B1, YrRub and QYrex.wgp-3BL previously mapped to chromosome 3B. Yrwh2 and its closely linked markers are potentially useful for developing stripe rust resistance wheat cultivars if used in combination with other genes.
Reassessing the Links between Regime Type and Economic Performance: Why Some Authoritarian Regimes Show Stable Growth and Others Do Not
Authors: Chandra Siddharth , Rudra Nita
Published: November 2013

This analysis challenges claims that regime type determines national economic performance, and hypothesizes that the level of public deliberation, rather than broad categories of regime type, is the driver of national economic performance across political systems; specifically, that negotiations, disagreements, and compromises between decentralized decision-making partisans (e.g., citizens, business representatives, professional associations, labor, and public administrators) are the underlying causal mechanism explaining the non-monotonic relationship between different types of political system and economic performance. Countries with high levels of public deliberation more often experience stable growth outcomes, while other countries can make radical changes in economic policy with uncertain outcome. The variation in public deliberation within regime type is significant, especially amongst authoritarian regimes. One startling implication is that, in certain situations, impressive gains in economic growth can be achieved only at the expense of active negotiation and participation in the policy-making process.
Life history of Bathyraja trachura from the eastern Bering Sea, with evidence of latitudinal variation in a deep-sea skate species
Authors: Winton Megan V. , Natanson Lisa J. , Kneebone Jeff , Cailliet Gregor M. , Ebert David A.
Published: November 2013

Although many skates possess life history characteristics that may make them vulnerable to exploitation, the detailed biological information needed to enact effective management schemes is lacking for most species. The objectives of this study were to provide age, growth, and maturity estimates for the roughtail skate, Bathyraja trachura, from the eastern Bering Sea. Maximum age was estimated at 36 yr based on band pair counts in vertebral centra. Of the four growth models applied, the logistic model provided the best description of growth (asymptotic total length = 911 mm; growth coefficient = 0.131 yr−1). There was no evidence of difference in growth between males and females. Females attained maturity at larger sizes and older ages than males. The median size-at-maturity was estimated at 741 mm total length (TL) for males and 796 mm TL for females; median age-at-maturity was estimated at 21.1 yr and 24.7 yr for males and females, respectively. The results of this study may indicate a latitudinal pattern in size and growth, with individuals from the eastern Bering Sea growing more slowly and reaching higher maximum ages than previously reported for specimens collected off the western coast of the continental United States.
ENTRUSTING WESTERN EUROPE TO THE CHURCH, 400–750
Authors: Wood Ian
Published: November 2013

Although there had been substantial donations to the church in the course of the last two centuries of the Roman Empire, the amount of property transferred to the episcopal church and to monasteries in the following two and a half centuries would seem to have been immense. Probably rather more than 30 per cent of the Frankish kingdom was given to ecclesiastical institutions; although the Anglo-Saxon church was only established after 597, it also acquired huge amounts of land, as did the churches of Spain and Italy, although the extent conveyed in the two peninsulas is harder to estimate. The scale of endowments helps explain the occasional criticisms of the extent of church property, and also the secularisations and reallocation of church land, and indeed suggest that the transfer of property out of the control of the church in Francia and England in the eighth century may have been greater than is often assumed. The transfer of land should probably also be seen as something other than a simple change of ownership. Church property provided the economic basis for cult, for the maintenance of clergy, who were unquestionably numerous, and for the poor. In social and economic, as well as religious terms, this marked a major break with the Classical World.
The effects of a hurricane on seedling dynamics and abiotic interactions in a tropical lower montane wet forest
Authors: Luke Denneko , McLaren Kurt , Wilson Byron
Published: November 2013

We assessed seedling dynamics and understorey light before and after a hurricane in five randomly selected 5 × 5-m subplots, within 30 permanent sample plots covering a total area of 3750 m2 in a lower montane wet tropical forest, Jamaica over a period of 3 y. Understorey light increased (≈ 60%) following the passage of Hurricane Dean in 2007 but decreased in 2009. Overall, seedling density was positively related to light and survivorship was positively related to both light and density. Mortality was significantly lower and most species recorded their highest growth when the canopy was open (2007–2008). However, lower diversity during this period coincided with higher (average) mortality of uncommon species. The hurricane altered the relative importance of interactions between light, seedling density and dynamics. Consequently, interactions were significant before or 2 y after but not 1 y after the hurricane and their significance varied among the years and species. Periodic changes in the importance of these interactions and the effects of the hurricane were used to separate 12 common species along a continuum of responses, which ranged from positive (lower mortality), neutral to negative (lower growth). Our results indicate that hurricanes have positive and negative effects on seedling dynamics; therefore an increase in the intensity and frequency of hurricanes will likely alter seedling composition, and hence forest structure.
Crete (Iron Age to Hellenistic)
Authors: Haysom Matthew
Published: November 2013

This year, the newly-published material bookends nearly a decade of archaeological work on the island with ADelt covering work on Crete from 2001 to 2004 and the second volume of Archaiologiko Ergo Kritis showcasing work in the years immediately before 2010. Several of the more impressive discoveries from the beginning of the decade have been known to the wider archaeological community for some time, but their publication in ADelt allows us to discuss them in greater detail and in their broader context. Overall, this is an opportune time to look at how some of the fieldwork done between 2001 and 2010 might contribute to our view of post-Bronze Age Crete.

The largest single contribution of the 2012–2013 reports to the Iron Age came in the form of the publication of the 2001–2004 seasons at the settlement site on Prophitis Elias hill near Smari (ID3655): an account that rounds out earlier notices for the 1999 and 2000 seasons (AR 53 [2006–2007] 107–08; ID1814). The site of Smari has entered the literature principally thanks to the megara with stone-lined hearths at their centre. The buildings have been interpreted as a ruler's dwelling, with some relationship to Cretan hearth temples, and as a locale for communal dining (Mazarakis-Ainian [1997] 220–21, 296; Prent [2007] 143; Sjogren [2007] 153; Wallace [2010] 112, 119). After a Middle Minoan occupation, the site's main period of use covers the whole of the Iron Age from Late Minoan IIIC through to the Orientalizing period, after which a small cult place remained in use through to the Classical period (fifth-to third-century BC figurines: Hatzi-Vallianou [2000]).
The fungus-growing termite Macrotermes natalensis harbors bacillaene-producing Bacillus sp. that inhibit potentially antagonistic fungi
Authors: Um Soohyun , Fraimout Antoine , Sapountzis Panagiotis , Oh Dong-Chan , Poulsen Michael
Published: November 2013

The ancient fungus-growing termite (Mactrotermitinae) symbiosis involves the obligate association between a lineage of higher termites and basidiomyceteTermitomycescultivar fungi. Our investigation of the fungus-growing termiteMacrotermes natalensisshows thatBacillusstrains fromM. natalensiscolonies produce a single major antibiotic, bacillaene A (1), which selectively inhibits known and putatively antagonistic fungi ofTermitomyces. Comparative analyses of the genomes of symbioticBacillusstrains revealed that they are phylogenetically closely related toBacillus subtilis, their genomes have high homology with more than 90% of ORFs being 100% identical and the sequence identities across the biosynthetic gene cluster for bacillaene are higher between termite-associated strains than to the cluster previously reported inB. subtilis. Our findings suggest that this lineage of antibiotic-producingBacillusmay be a defensive symbiont involved in the protection of the fungus-growing termite cultivar.
Influence of spatial configurations on electromagnetic interference shielding of ordered mesoporous carbon/ordered mesoporous silica/silica composites
Authors: Wang Jiacheng , Zhou Hu , Zhuang Jiandong , Liu Qian
Published: November 2013

Ordered mesoporous carbons (OMCs), obtained by nanocasting using ordered mesoporous silicas (OMSs) as hard templates, exhibit unique arrangements of ordered regular nanopore/nanowire mesostructures. Here, we used nanocasting combined with hot-pressing to prepare 10 wt% OMC/OMS/SiO2 ternary composites possessing various carbon mesostructure configurations of different dimensionalities (1D isolated CS41 carbon nanowires, 2D hexagonal CMK-3 carbon and 3D cubic CMK-1 carbon). The electric/dielectric properties and electromagnetic interference (EMI) shielding efficiency (SE) of the composites were influenced by spatial configurations of carbon networks. The complex permittivity and the EMI SE of the composites in the X-band frequency range decreased for the carbon mesostructures in the following order: CMK-3-filled > CMK-1-filled > CS41-filled. Our study provides technical directions for designing and preparing high-performance EMI shielding materials. Our OMC-based silica composites can be used for EMI shielding, especially in high-temperature or corrosive environments, owing to the high stability of the OMC/OMS fillers and the SiO2 matrix. Related shielding mechanisms are also discussed.
A new synthetic route to hollow Co3O4 octahedra for supercapacitor applications
Authors: Cao Yuebin , Yuan Fangli , Yao Mingshui , Bang Jin Ho , Lee Jung-Ho
Published: November 2013

Hollow Co3O4 octahedra, synthesized through a new solvothermal method, exhibited a charge storage capacity of 192 F g−1 with good long-term cyclability.
Oxalate route for promoting activity of manganese oxide catalysts in total VOCs’ oxidation: effect of calcination temperature and preparation method
Authors: Tang Wenxiang , Wu Xiaofeng , Li Dongyan , Wang Zhen , Liu Gang , Liu Haidi , Chen Yunfa
Published: November 2013

Oxalate route was applied to synthesize mesoporous manganese oxides and their catalytic activity for VOCs’ oxidation was significantly promoted.
Theory and experiment on resonant frequencies of liquid-air interfaces trapped in microfluidic devices
Authors: Chindam Chandraprakash , Nama Nitesh , Ian Lapsley Michael , Costanzo Francesco , Jun Huang Tony
Published: November 2013

Bubble-based microfluidic devices have been proven to be useful for many biological and chemical studies. These bubble-based microdevices are particularly useful when operated at the trapped bubbles' resonance frequencies. In this work, we present an analytical expression that can be used to predict the resonant frequency of a bubble trapped over an arbitrary shape. Also, the effect of viscosity on the dispersion characteristics of trapped bubbles is determined. A good agreement between experimental data and theoretical results is observed for resonant frequency of bubbles trapped over different-sized rectangular-shaped structures, indicating that our expression can be valuable in determining optimized operational parameters for many bubble-based microfluidic devices. Furthermore, we provide a close estimate for the harmonics and a method to determine the dispersion characteristics of a bubble trapped over circular shapes. Finally, we present a new method to predict fluid properties in microfluidic devices and complement the explanation of acoustic microstreaming.
Improving thermoelectric efficiency in organic-metal nanocomposites via extra-low thermal boundary conductance
Authors: Jin Yansha , Nola Sam , Pipe Kevin P. , Shtein Max
Published: November 2013

In organic semiconductors, the Wiedemann-Franz law is often violated, potentially enabling independent control over electrical and thermal conductivities, as observed here with the organic-metal nanocomposites. This effect is attributed to the interface between metal particles and organic matrix materials impeding thermal transport. Thermal conductivity (kth) can be decoupled from electrical conductivity (σe) in the composite of an archetypal organic semiconductor (Copper Phthalocyanine, CuPc) and silver, with thermal boundary conductance as low as 13 MW/m2K at the interface. We show that kth decreases with volume fraction occupied by silver nanoparticles (xAg%) in the dilute limit, reaching a minimum value at a concentration xAg%(min)=18%, while σe exceeds that of the pure organic semiconductor. Further modeling indicates that ZT values of organic-inorganic nanocomposites can be potentially enhanced 10 fold around xf%(min), compared to ZT of the pure compounds. These findings suggest a novel pathway for the future design of organic thermoelectric materials.
Plasmonic nanohelix metamaterials with tailorable giant circular dichroism
Authors: Gibbs J. G. , Mark A. G. , Eslami S. , Fischer P.
Published: November 2013

Plasmonic nanohelix arrays are shown to interact with electromagnetic fields in ways not typically seen with ordinary matter. Chiral metamaterials (CMMs) with feature sizes small with respect to the wavelength of visible light are a promising route to experimentally achieve such phenomena as negative refraction without the need for simultaneously negative ε and μ. Here we not only show that giant circular dichroism in the visible is achievable with hexagonally arranged plasmonic nanohelix arrays, but that we can precisely tune the optical activity via morphology and lattice spacing. The discrete dipole approximation is implemented to support experimental data.
Quantifying the local Seebeck coefficient with scanning thermoelectric microscopy
Authors: Walrath J. C. , Lin Y. H. , Pipe K. P. , Goldman R. S.
Published: November 2013

We quantify the local Seebeck coefficient with scanning thermoelectric microscopy, using a direct approach to convert temperature gradient-induced voltages (V) to Seebeck coefficients (S). We use a quasi-3D conversion matrix that considers both the sample geometry and the temperature profile. For a GaAs p-n junction, the resulting S-profile is consistent with that computed using the free carrier concentration profile. This combined computational-experimental approach is expected to enable nanoscale measurements of S across a wide variety of heterostructure interfaces.
On the exact evaluation of spin networks
Authors: Freidel Laurent , Hnybida Jeff
Published: November 2013

We introduce a fully coherent spin network amplitude whose expansion generates all SU(2) spin networks associated with a given graph. We then give an explicit evaluation of this amplitude for an arbitrary graph. We show how this coherent amplitude can be obtained from the specialization of a generating functional obtained by the contraction of parametrized intertwiners à la Schwinger. We finally give the explicit evaluation of this generating functional for arbitrary graphs.
Kerov's interlacing sequences and random matrices
Authors: Bufetov Alexey
Published: November 2013

To a N × N real symmetric matrix Kerov assigns a piecewise linear function whose local minima are the eigenvalues of this matrix and whose local maxima are the eigenvalues of its (N − 1) × (N − 1) submatrix. We study the scaling limit of Kerov's piecewise linear functions for Wigner and Wishart matrices. For Wigner matrices the scaling limit is given by the Verhik-Kerov-Logan-Shepp curve which is known from asymptotic representation theory. For Wishart matrices the scaling limit is also explicitly found, and we explain its relation to the Marchenko-Pastur limit spectral law.
Laterally extended thin liquid films with inertia under external vibrations
Authors: Bestehorn Michael
Published: November 2013

We consider thin liquid films on a horizontal, solid, and completely wetting substrate. The substrate is subjected to oscillatory accelerations in the normal direction and/or in the horizontal direction. A linear Floquet analysis shows that the planar film surface loses stability if amplitudes and frequencies of the harmonic oscillations meet certain criteria. Based on the long wave lubrication approximation, we present an integral boundary layer model where the z component is integrated out and the spatial dimension is reduced by one. The linear stability analysis of this model shows good agreement with the exact problem and with the linearized long wave equations. Pattern formation in the nonlinear regime is computed numerically from the long wave model in two and three spatial dimensions. Normal oscillations show the traditional Faraday patterns such as squares and hexagons. Lateral oscillations cause a pattern formation scenario similar to spinodal dewetting, namely coarsening and no rupture. For certain amplitude and frequency ranges, combined lateral and normal oscillations can give rise to one or more traveling drops. Finally, we discuss the control of a drop's motion in the horizontal plane.
Synthesis and characterization of Fe-doped SnS thin films by chemical bath deposition technique for solar cells applications
Authors: Reghima Meriem , Akkari Anis , Guasch Cathy , Castagné Michel , Kamoun-Turki Najoua
Published: November 2013

Undoped zinc blend tin sulphide can be used as an absorber material in thin film solar cells. In the present study, SnS thin film has been doped with iron (Fe) at different concentrations (y = [Fe]/[Sn] = 4%, 6%, 8%, 10%). Structural, morphological, chemical, optical, and electrical properties were studied by X-Ray diffraction, scanning electron microscopy associated with energy dispersive spectroscopy, atomic force microscopy, and thermally stimulated current. X-ray diffraction study shows that better crystallinity is obtained for y = 8%. Scanning electron microscopy reveals that the surface morphology of the films strongly depends on the doping concentration. The energy dispersive spectroscopy shows the presence of Fe. The band gap energy is found to be about 1.6 eV. The thermally stimulated current is dominated by the trapping centers. It increases for y = 4% compared to the undoped SnS thin film. The activation energy of trapping centers in undoped and doped SnS thin layers is also calculated.
Investigation of the graphene based planar plasmonic filters
Authors: Li Hong-Ju , Wang Ling-Ling , Liu Jian-Qiang , Huang Zhen-Rong , Sun Bin , Zhai Xiang
Published: November 2013

We investigate numerically the edge modes supported by graphene ribbons and the planar band-stop filter consisting of a graphene ribbon lateral coupled a graphene ring resonator by using the finite-difference time-domain method. Simulation results reveal that the edge modes can enhance the electromagnetic coupling between objects indeed and this structure realizes perfect, tunable filtering effect. Successively, the channel-drop filter is constructed. Especially, the proposed structures can be designed and the size of the ring is changed by creating non-uniform conductivity patterns on monolayer graphene. Our studies will benefit the fabrication of the planar, ultra-compact devices in the mid-infrared region.
Photocurrent extraction efficiency in colloidal quantum dot photovoltaics
Authors: Kemp K. W. , Wong C. T. O. , Hoogland S. H. , Sargent E. H.
Published: November 2013

The efficiency of photocurrent extraction was studied directly inside operating Colloidal Quantum Dot (CQD) photovoltaic devices. A model was derived from first principles for a thin film p-n junction with a linearly spatially dependent electric field. Using this model, we were able to clarify the origins of recent improvement in CQD solar cell performance. From current-voltage diode characteristics under 1 sun conditions, we extracted transport lengths ranging from 39 nm to 86 nm for these materials. Characterization of the intensity dependence of photocurrent extraction revealed that the dominant loss mechanism limiting the transport length is trap-mediated recombination.
Broadband isotropic μ-near-zero metamaterials
Authors: Belov Pavel A. , Slobozhanyuk Alexey P. , Filonov Dmitry S. , Yagupov Ilya V. , Kapitanova Polina V. , Simovski Constantin R. , Lapine Mikhail , Kivshar Yuri S.
Published: November 2013

Natural diamagnetism, while being a common phenomenon, is limited to permeability values close to unity. Artificial diamagnetics, to the contrary, can be engineered to provide much lower values and may even possess an effective permeability close to zero. In this letter, we provide an experimental confirmation of the possibility to obtain extremely low permeability values by manufacturing an isotropic metamaterial composed of conducting cubes. We show that the practical assembly is quite sensitive to fabrication tolerances and demonstrate that permeability of about μ=0.15 is realisable.
Improved visible light driven photoelectrochemical properties of 3C-SiC semiconductor with Pt nanoparticles for hydrogen generation
Authors: Tae Song Jun , Mashiko Hisanori , Kamiya Masayuki , Nakamine Yoshifumi , Ohtomo Akira , Iwasaki Takayuki , Hatano Mutsuko
Published: November 2013

We propose the n-type 3C-SiC with Pt nanoparticles (Pt NPs) as photo-anode for photoelectrochemical hydrogen (H2) generation. We found that band-edge structure of 3C-SiC is suitable for H2 generation, and the property can be optimized by dopant (nitrogen) concentration in 3C-SiC. We also confirmed that Pt NPs enhance photoelectrochemical properties showing 0.2%–0.8% higher Incident Photon-to-Current Efficiency than bare 3C-SiC in visible wavelength despite diminished light absorption. Solar-conversion efficiency increases approximately 6.3 times, and H2 production is improved by 6.5 times with 33% of Faradaic efficiency. Lastly, 3C-SiC surface corrosion is effectively inhibited.
Temperature-dependent terahertz magnetic dipole radiation from antiferromagnetic GdFeO3 ceramics
Authors: Fu Xiaojian , Xi Xiaoqing , Bi Ke , Zhou Ji
Published: November 2013

Temperature-dependent terahertz magnetic dipole radiation in antiferromagnetic GdFeO3 ceramic is investigated both theoretically and experimentally in this work. A two-level quantum transition mechanism is introduced to describe the excitation-radiation process, and radiative lifetime is derived analytically from the change of spin state density during this process. Terahertz spectral measurements demonstrate that the radiative frequency exhibits a red-shift and lifetime shortens as temperature increases, which is in good agreement with theoretical predictions. The temperature-sensitive radiative frequency and excellent terahertz emission mean that the antiferromagnetic ceramics show potential for application in terahertz sensors and frequency-tunable terahertz lasers.
Note: Electrical modeling and characterization of voltage gradient in liquid crystal microlenses
Authors: Urruchi V. , Algorri J. F. , Marcos C. , Sánchez-Pena J. M.
Published: November 2013

In this work, a novel equivalent electric circuit for modeling liquid crystal microlenses is proposed. This model is focused on explaining a lens behavior at the micrometric scale, using its manufacturing parameters. It suggests an approach to predict the solution of the voltage gradient distribution across a microlens. An interesting feature of the model is that it provides an analytical solution for microlenses with modal and hole-patterned electrode schemes, by a simple software tool. The model flexibility allows lens designers to apply complex waveform signals with different harmonics. The voltage distribution has been tested. The simulated and measured voltage profiles are fairly in agreement.
Residual stress dependant anisotropic band gap of various (hkl) oriented BaI2 films
Authors: Kumar Pradeep , Gulia Vikash , Vedeshwar Agnikumar G.
Published: November 2013

The thermally evaporated layer structured BaI2 grows in various completely preferred (hkl) film orientations with different growth parameters like film thickness, deposition rate, substrate temperature, etc. which were characterized by structural, morphological, and optical absorption measurements. Structural analysis reveals the strain in the films and the optical absorption shows a direct type band gap. The varying band gaps of these films were found to scale linearly with their strain. The elastic moduli and other constants were also calculated using Density Functional Theory (DFT) formalism implemented in WIEN2K code for converting the strain into residual stress. Films of different six (hkl) orientations show stress free anisotropic band gaps (2.48–3.43 eV) and both positive and negative pressure coefficients. The negative and positive pressure coefficients of band gap are attributed to the strain in I-I (or Ba-Ba or both) and Ba-I distances along [hkl], respectively. The calculated band gaps are also compared with those experimentally determined. The average pressure coefficient of band gap of all six orientations (−0.071 eV/GPa) found to be significantly higher than that calculated (−0.047 eV/GPa) by volumetric pressure dependence. Various these issues have been discussed with consistent arguments. The electron effective mass me*=0.66m0 and the hole effective mass mh*=0.53m0 have been determined from the calculated band structure.
Lateral spin valves with two-different Heusler-alloy electrodes on the same platform
Authors: Oki S. , Yamada S. , Tanikawa K. , Yamasaki K. , Miyao M. , Hamaya K.
Published: November 2013

Using room-temperature molecular beam epitaxy on Si(111), we demonstrate Heusler-alloy bilayers consisting of L21-Co2FeSi (CFS) and D03-Fe3Si (FS). By fabricating lateral spin valves with L21-CFS and D03-FS electrodes, we can see ideal spin signals even though we use one L21-CFS as a spin injector and another D03-FS as a spin detector. The difference in the spin absorption between L21-CFS and D03-FS can also be examined, and we find that the spin resistance of D03-FS is larger than that of L21-CFS. This work will be useful for understanding spin transport in lateral spin-valve devices with different Heusler-alloy electrodes.
Universal conductance fluctuations in electrolyte-gated SrTiO3 nanostructures
Authors: Stanwyck Sam W. , Gallagher P. , Williams J. R. , Goldhaber-Gordon David
Published: November 2013

We report low-temperature magnetoconductance measurements of a patterned two-dimensional electron system at the surface of strontium titanate, gated by an ionic liquid electrolyte. We observe universal conductance fluctuations, a signature of phase-coherent transport in mesoscopic devices. From the universal conductance fluctuations, we extract an electron dephasing rate linear in temperature, characteristic of electron-electron interaction in a disordered conductor. The dephasing rate has a temperature-independent offset, which could possibly be explained by the presence of unscreened local magnetic moments in the sample.
Acoustic lens with variable focal length for photoacoustic microscopy
Authors: Song Chaolong , Xi Lei , Jiang Huabei
Published: November 2013

A liquid acoustic lens with variable focal length is described for photoacoustic microscopy. This liquid lens takes advantage of the elastic and deformable lens interface to tune its focal length in a pneumatical manner. The curvature of the lens interface as well as the dependant focal length was characterized as a function of the infusion volume of the liquid. Experiments were carried out to demonstrate the zooming ability of this liquid acoustic lens. Targets embedded at different depths were photoacoustically imaged without performing mechanically axial scanning.
Peptide-Based Star Polymers as Potential siRNA Carriers
Authors: Lam Shu Jie , Sulistio Adrian , Ladewig Katharina , Wong Edgar H. H. , Blencowe Anton , Qiao Greg G.
Published: November 2013

16- and 32-arm star polymers were synthesised using poly(amido amine) (PAMAM) dendrimers as multifunctional initiators for the ring-opening polymerisation (ROP) of ϵ-Z-l-lysine N-carboxyanhydride (Lys NCA) via the core-first approach. The resulting star polymers were subsequently post-functionalised with poly(ethylene glycol) (PEG) via carbodiimide coupling, potentially improving the biodistribution of the stars in vivo. De-protection of the carboxybenzyl (Cbz)-protected star arms yielded water-soluble cationic poly(l-lysine) (PLL) star polymers with hydrodynamic radii ranging from 2.0 to 3.3 nm. Successful complexation of the PLL star polymers with double-stranded oligodeoxynucleotides (ODNs)—a mimic for small interfering RNA (siRNA)—was achieved at a nitrogen-to-phosphate (N/P) ratio of 5. Cell viability studies using HEK293T cells indicated the ‘safe’ concentration for these polymers is within a suitable window for the delivery of siRNA therapeutics.
Changes in phosphorus pools in three soils upon addition of legume residues differing in carbon/phosphorus ratio
Authors: Alamgir Md , Marschner Petra
Published: November 2013

Previously we showed that addition of legume residues affected the size of different soil phosphorus (P) pools in an alkaline loamy sand soil. Here, we tested whether the changes in soil P pools induced by residue addition are generally applicable or whether they are dependent on certain soil properties. Three legume residues differing in P concentration, faba bean (Vicia faba L.) (high P), chickpea (Cicer arietinum L.) (medium P), and white lupin (Lupinus albus L.) (low P), were added at a rate of 20 g residue kg–1 soil to three different soils with low Colwell-P concentration: Mt Bold (sandy clay loam, high organic carbon (C) content, pH 5.1), Monarto (loamy sand, low organic C content, pH 7.5), and Langhorne Creek (sandy loam, low organic C content, pH 8.1). Soil P pools were assessed by sequential P fractionation on days 0 and 42. In residue-amended soils from day 0 to day 42, the concentrations of water-soluble and microbial P decreased, whereas the concentrations of NaHCO3-Pi (inorganic P) and NaOH-Po (organic P) increased. The magnitude of these changes differed among soils, being greatest in the Mt Bold soil. Residue addition had little or no effect on the concentrations of NaOH-Pi and residual P, which also did not change significantly over time. Principal component analysis of the data showed that the size of the P pools was related to soil properties; high concentrations of HCl-P were associated with high pH and calcium concentrations, high concentrations of NaOH-P and residual P were correlated with high aluminium, silt, organic C, and total nitrogen and P. In the unamended soil on day 0, the concentration of NaHCO3-Pi was correlated with the clay content, whereas on day 42, the concentrations of the labile P pools were related to amount of P added with the residues. It can be concluded that most effects of residue addition to soils on microbial activity and growth and soil P pools can be generalised across the three soil used in this study, but that the size of the P pools is affected by soil properties such as organic C content, pH, and texture.
RVX-208, an inhibitor of BET transcriptional regulators with selectivity for the second bromodomain
Authors: Picaud Sarah , Wells Christopher , Felletar Ildiko , Brotherton Deborah , Martin Sarah , Savitsky Pavel , Diez-Dacal Beatriz , Philpott Martin , Bountra Chas , Lingard Hannah , Fedorov Oleg , Müller Susanne , Brennan Paul E. , Knapp Stefan , Filippakopoulos Panagis
Published: November 2013

Significance

Bromo and extraterminal (BET) proteins have diverse roles in regulating tissue-specific transcriptional programs, raising safety concerns for their inhibition and suggesting that targeting of specific isoforms or even specific domains within this subfamily is important. We report the discovery and characterization of RVX-208 as a domain-selective inhibitor of BETs and provide a potential mechanism of action of a clinical compound that was identified based on phenotypic screens.