Laser-engineered heavy hydrocarbons: Old materials with new opportunities.

Polycyclic heavy hydrocarbons (HHs) such as coal, tar, and pitch are a family of materials with extremely rich and complex chemistry, representing a massive opportunity for their use in a range of potential applications. The present work shows that optimal selection of initial HHs based on molecular constituents is essential in tuning the material for a particular and targeted electronic application. Combining the selection of feedstock chemistry (H:C and aromatic content) and controlling variable laser treatment parameters (laser power, speed, and focus) lead to full control over the H:C ratio, sp2 concentration, and degree of graphitic stacking order of the products. The broad intertunability of these factors results from a wide distribution of carbon material crystallinity from amorphous to highly graphitic and a broad distribution of electrical conductivity up to 103 S/m.

The u-series: A separable decomposition for electrostatics computation with improved accuracy.

The evaluation of electrostatic energy for a set of point charges in a periodic lattice is a computationally expensive part of molecular dynamics simulations (and other applications) because of the long-range nature of the Coulomb interaction. A standard approach is to decompose the Coulomb potential into a near part, typically evaluated by direct summation up to a cutoff radius, and a far part, typically evaluated in Fourier space. In practice, all decomposition approaches involve approximations-such as cutting off the near-part direct sum-but it may be possible to find new decompositions with improved trade-offs between accuracy and performance. Here, we present the u-series, a new decomposition of the Coulomb potential that is more accurate than the standard (Ewald) decomposition for a given amount of computational effort and achieves the same accuracy as the Ewald decomposition with approximately half the computational effort. These improvements, which we demonstrate numerically using a lipid membrane system, arise because the u-series is smooth on the entire real axis and exact up to the cutoff radius. Additional performance improvements over the Ewald decomposition may be possible in certain situations because the far part of the u-series is a sum of Gaussians and can thus be evaluated using algorithms that require a separable convolution kernel; we describe one such algorithm that reduces communication latency at the expense of communication bandwidth and computation, a trade-off that may be advantageous on modern massively parallel supercomputers.

Tailoring the optical properties of MoS2 and WS2 single layers via organic functionalization.

Tailoring the structural and electronic properties of 2D materials is fundamental to boost their use in a wide range of technological applications. In this paper, by means of first principles simulations, we show how methyl functionalization of MoS2 and WS2 monolayers can be employed to change their energy gap, tune their optoelectronic properties and modify the relative stability of their structural phases (or polytypes). In particular for both compound monolayers, we find that the most stable semiconducting H phase becomes metallic upon methyl functionalization, while in the metastable T' phase the band gap increases as a function of the -CH3 coverage; correspondingly the phase stability is reversed and the on-set of the optical absorption is blue-shifted.

Comparison of Surface Water Quality and Yields from Organically and Conventionally Produced Sweet Corn Plots with Conservation and Conventional Tillage.

Organic agricultural systems are often assumed to be more sustainable than conventional farming, yet there has been little work comparing surface water quality from organic and conventional production, especially under the same cropping sequence. Our objective was to compare nutrient and sediment losses, as well as sweet corn ( L. var. ) yield, from organic and conventional production with conventional and conservation tillage. The experiment was located in the Appalachian Mountains of North Carolina. Four treatments, replicated four times, had been in place for over 18 yr and consisted of conventional tillage (chisel plow and disk) with conventional production (CT/Conven), conservation no-till with conventional production (NT/Conven), conventional tillage with organic production (CT/Org), and conservation no-till with organic production (NT/Org). Water quality (surface flow volume; nitrogen, phosphorus, and sediment concentrations) and sweet corn yield data were collected in 2011 and 2012. Sediment and sediment-attached nutrient losses were influenced by tillage and cropping system in 2011, due to higher rainfall, and tillage in 2012. Soluble nutrients were affected by the nutrient source and rate, which are a function of the cropping system. Sweet corn marketable yields were greater in conventional systems due to high weed competition and reduced total nitrogen availability in organic treatments. When comparing treatment efficiency (yield kg ha /nutrient loss kg ha ), the NT/Conven treatment had the greatest sweet corn yield per unit of nutrient and sediment loss. Other treatment ratios were similar to each other; thus, it appears the most sustainably productive treatment was NT/Conven.

Mutations in PIK3CD can cause hyper IgM syndrome (HIGM) associated with increased cancer susceptibility.

Autosomal dominant gain of function mutations in the gene encoding PI3K p110δ were recently associated with a novel combined immune deficiency characterized by recurrent sinopulmonary infections, CD4 lymphopenia, reduced class-switched memory B cells, lymphadenopathy, CMV and/or EBV viremia and EBV-related lymphoma. A subset of affected patients also had elevated serum IgM. Here we describe three patients in two families who were diagnosed with HIGM at a young age and were recently found to carry heterozygous mutations in PIK3CD. These patients had an abnormal circulating B cell distribution featuring a preponderance of early transitional (T1) B cells and plasmablasts. When stimulated in vitro, PIK3CD mutated B cells were able to secrete class-switched immunoglobulins. This finding implies that the patients' elevated serum IgM levels were unlikely a product of an intrinsic B cell functional inability to class switch. All three patients developed malignant lymphoproliferative syndromes that were not associated with EBV. Thus, we identified a novel subset of patients with PIK3CD mutations associated with HIGM, despite indications of preserved in vitro B cell class switch recombination, as well as susceptibility to non-EBV-associated malignancies.

Biomolecular simulation: a computational microscope for molecular biology.

Molecular dynamics simulations capture the behavior of biological macromolecules in full atomic detail, but their computational demands, combined with the challenge of appropriately modeling the relevant physics, have historically restricted their length and accuracy. Dramatic recent improvements in achievable simulation speed and the underlying physical models have enabled atomic-level simulations on timescales as long as milliseconds that capture key biochemical processes such as protein folding, drug binding, membrane transport, and the conformational changes critical to protein function. Such simulation may serve as a computational microscope, revealing biomolecular mechanisms at spatial and temporal scales that are difficult to observe experimentally. We describe the rapidly evolving state of the art for atomic-level biomolecular simulation, illustrate the types of biological discoveries that can now be made through simulation, and discuss challenges motivating continued innovation in this field.

Use of a preputial circumferential mucosal flap for hypospadias management in a Boston terrier.

An eight-week-old male Boston terrier presented for penile desiccation and urine pooling in the prepuce due to congenital hypospadias. An advancement flap was created from the dorsal mucosa of the incompletely formed prepuce and sutured circumferentially to construct a longer distal preputial mucosa. V- to Y-plasty of the ventral abdominal skin was utilised to create the preputial skin overlying the mucosal flap. Urethrostomy and partial penile amputation were also performed. Following surgery, the clinical signs of penile desiccation and preputial urine pooling resolved and acceptable cosmetic appearance was achieved. This technique may be considered for glandular or penile hypospadias or following resection of the ventral aspect of the distal prepuce when inadequate tissue is present for a simple two-layer closure of the preputial mucosa and skin.

International consensus for a definition of disease flare in lupus.

The Lupus Foundation of America (LFA) convened an international working group to obtain a consensus definition of disease flare in lupus. With help from the Paediatric Rheumatology International Trials Organization (PRINTO), two web-based Delphi surveys of physicians were conducted. Subsequently, the LFA held a second consensus conference followed by a third Delphi survey to reach a community-wide agreement for flare definition. Sixty-nine of the 120 (57.5%) polled physicians responded to the first survey. Fifty-nine of the responses were available to draft 12 preliminary statements, which were circulated in the second survey. Eighty-seven of 118 (74%) physicians completed the second survey, with an agreement of 70% for 9/12 (75%) statements. During the second conference, three alternative flare definitions were consolidated and sent back to the international community. One hundred and sixteen of 146 (79.5%) responded, with agreement by 71/116 (61%) for the following definition: "A flare is a measurable increase in disease activity in one or more organ systems involving new or worse clinical signs and symptoms and/or laboratory measurements. It must be considered clinically significant by the assessor and usually there would be at least consideration of a change or an increase in treatment." The LFA proposes this definition for lupus flare on the basis of its high face validity.

Strain engineering and one-dimensional organization of metal-insulator domains in single-crystal vanadium dioxide beams.

Correlated electron materials can undergo a variety of phase transitions, including superconductivity, the metal-insulator transition and colossal magnetoresistance. Moreover, multiple physical phases or domains with dimensions of nanometres to micrometres can coexist in these materials at temperatures where a pure phase is expected. Making use of the properties of correlated electron materials in device applications will require the ability to control domain structures and phase transitions in these materials. Lattice strain has been shown to cause the coexistence of metallic and insulating phases in the Mott insulator VO(2). Here, we show that we can nucleate and manipulate ordered arrays of metallic and insulating domains along single-crystal beams of VO(2) by continuously tuning the strain over a wide range of values. The Mott transition between a low-temperature insulating phase and a high-temperature metallic phase usually occurs at 341 K in VO(2), but the active control of strain allows us to reduce this transition temperature to room temperature. In addition to device applications, the ability to control the phase structure of VO(2) with strain could lead to a deeper understanding of the correlated electron materials in general.

Bacterial community composition in Brazilian Anthrosols and adjacent soils characterized using culturing and molecular identification.

Microbial community composition was examined in two soil types, Anthrosols and adjacent soils, sampled from three locations in the Brazilian Amazon. The Anthrosols, also known as Amazonian dark earths, are highly fertile soils that are a legacy of pre-Columbian settlement. Both Anthrosols and adjacent soils are derived from the same parent material and subject to the same environmental conditions, including rainfall and temperature; however, the Anthrosols contain high levels of charcoal-like black carbon from which they derive their dark color. The Anthrosols typically have higher cation exchange capacity, higher pH, and higher phosphorus and calcium contents. We used culture media prepared from soil extracts to isolate bacteria unique to the two soil types and then sequenced their 16S rRNA genes to determine their phylogenetic placement. Higher numbers of culturable bacteria, by over two orders of magnitude at the deepest sampling depths, were counted in the Anthrosols. Sequences of bacteria isolated on soil extract media yielded five possible new bacterial families. Also, a higher number of families in the bacteria were represented by isolates from the deeper soil depths in the Anthrosols. Higher bacterial populations and a greater diversity of isolates were found in all of the Anthrosols, to a depth of up to 1 m, compared to adjacent soils located within 50-500 m of their associated Anthrosols. Compared to standard culture media, soil extract media revealed diverse soil microbial populations adapted to the unique biochemistry and physiological ecology of these Anthrosols.

Some antiphospholipid antibodies bind to hemostasis and fibrinolysis proteases and promote thrombosis.

It is generally accepted that the major autoantigen for antiphospholipid antibodies (aPL) is beta(2)glycoprotein I (beta(2)GPI). Interestingly, some aPL bind to beta(2)GPI and the homologous enzymatic domains of several proteases involved in hemostasis and fibrinolysis, and correspondingly hinder anticoagulant regulation and resolution of clots. These findings are consistent with several early findings of aPL and provide a new perspective about some aPL in terms of their binding specificities and related functional properties in promoting thrombosis. In addition, homologous enzymatic domains of the involved proteases share conformation epitope(s) with beta(2)GPI, thus providing a possible structural basis for some non-mutually exclusive mechanisms of aPL-mediated thrombosis.

The formation conditions of chondrules and chondrites.

Chondrules, which are roughly millimeter-sized silicate-rich spherules, dominate the most primitive meteorites, the chondrites. They formed as molten droplets and, judging from their abundances in chondrites, are the products of one of the most energetic processes that operated in the early inner solar system. The conditions and mechanism of chondrule formation remain poorly understood. Here we show that the abundance of the volatile element sodium remained relatively constant during chondrule formation. Prevention of the evaporation of sodium requires that chondrules formed in regions with much higher solid densities than predicted by known nebular concentration mechanisms. These regions would probably have been self-gravitating. Our model explains many other chemical characteristics of chondrules and also implies that chondrule and planetesimal formation were linked.

Botulinum toxin type A as an adjunct to the surgical treatment of the medial rotation deformity of the shoulder in birth injuries of the brachial plexus.

We retrospectively reviewed 26 patients who underwent reconstruction of the shoulder for a medial rotation contracture after birth injury of the brachial plexus. Of these, 13 patients with a mean age of 5.8 years (2.8 to 12.9) received an injection of botulinum toxin type A into the pectoralis major as a surgical adjunct. They were matched with 13 patients with a mean age of 4.0 years (1.9 to 7.2) who underwent an identical operation before the introduction of botulinum toxin therapy to our unit. Pre-operatively, there was no significant difference (p = 0.093) in the modified Gilbert shoulder scores for the two groups. Post-operatively, the patients who received the botulinum toxin had significantly better Gilbert shoulder scores (p = 0.012) at a mean follow-up of three years (1.5 to 9.8). It appears that botulinum toxin type A produces benefits which are sustained beyond the period for which the toxin is recognised to be active. We suggest that by temporarily weakening some of the power of medial rotation, afferent signals to the brain are reduced and cortical recruitment for the injured nerves is improved.

High-order quantum resonances observed in a periodically kicked Bose-Einstein condensate.

We have observed high-order quantum resonances in a realization of the quantum delta-kicked rotor, using Bose-condensed Na atoms subjected to a pulsed standing wave of laser light. These resonances occur for pulse intervals that are rational fractions of the Talbot time, and are characterized by ballistic momentum transfer to the atoms. The condensate's narrow momentum distribution not only permits the observation of the quantum resonances at 3/4 and 1/3 of the Talbot time, but also allows us to study scaling laws for the resonance width in quasimomentum and pulse interval.

Peptides from antibodies to DNA elicit cytokine release from peripheral blood mononuclear cells of patients with systemic lupus erythematosus: relation of cytokine pattern to disease duration.

Peptides from VH regions of antibodies to DNA drive immune responses in systemic lupus erythematosus (SLE). We studied peptide-induced cytokine release by peripheral blood mononuclear cells (PBMC) of patients, the influence of peptide concentration, disease characteristics and HLA-D haplotypes. Cells secreting cytokines (IFNgamma, IL-2, IL-4 and IL-10) were measured by ELISPOT in PBMC from 31 patients with SLE and 20 matched healthy controls in response to seven peptides (A-G) from the CDR1/FR2 to CDR2/FR3 VH regions of human anti-DNA MAbs. Disease activity was assessed by SELENA-SLEDAI. HLA-DR and -DQ alleles were determined by molecular typing techniques. PBMC from significantly higher proportions of SLE patients than controls responded to VH peptides by generating IFNgamma and IL-10. Type of cytokines released in response to at least one peptide (D) depended on antigen concentration. Cytokine release was not associated with clinical features of SLE except for disease duration. A shift occurred from IFNgamma, IL-4 and IL-10 production in early disease to IL-4 and IL-10 in late disease (suggesting increasing TH2-like responses over time). Three peptides (B, D, G) were more stimulatory in the SLE patients than controls. Although none of the peptides was restricted by any particular MHC class II allele, among responders there was increased prevalence of HLA- DQB1*0201 and/or DRB1*0301, alleles known to predispose to SLE. Thus, responses to some VH peptides are more frequent in SLE and vary with disease duration. Increased responses in individuals with HLA class II genotypes that predispose to SLE suggest that peptide presentation by those molecules permits brisker peripheral blood cell responses to autoantibody peptides, thus increasing risk for disease.

Outcome after later combined brachial plexus and shoulder surgery after birth trauma.

Of 22 infants aged between 11 and 29 months who underwent a combined reconstruction of the upper brachial plexus and shoulder for the sequelae of a birth injury, 19 were followed up for two or more years. The results were evaluated using a modified Gilbert scale. Three patients required a secondary procedure before follow-up. Three patients had a persistent minor internal rotation contracture. All improved by at least two grades on a modified Gilbert scale.

Perioperative complications associated with brachial plexus repair in infants.

This report details the complications experienced during 100 consecutive cases of brachial plexus surgery in infants. There were eight perioperative complications. There was no mortality or permanent sequelae from any complication.

Polymorphisms of human CD19 gene: possible association with susceptibility to systemic lupus erythematosus in Japanese.

CD19 regulates the signaling for B lymphocyte development, activation and proliferation. In mice, CD19 deficiency and overexpression were shown to result in hypogammaglobulinemia and autoantibody production, respectively. In the present study, we screened for the polymorphisms of CD19, and examined the detected polymorphisms for the association with rheumatoid arthritis (RA), Crohn's disease and systemic lupus erythematosus (SLE). Two SNPs, c.705G>T (P235P and IVS14-30C>T, were decreased (P = 0.0096 and P = 0.028, respectively), in SLE. A GT repeat polymorphism, c.*132(GT)(12-18), was detected within the 3'-untranslated region, and individuals with > or =15 times repeat was significantly increased in the independent two groups of Japanese SLE patients (P = 0.011 and P = 0.035, respectively); the overall difference between total SLE and controls was striking (P = 0.0061). No association was observed for RA and Crohn's disease. In addition, no variations other than the common polymorphisms were detected in four patients with common variable immunodeficiency, the phenotype of which resembles CD19 deficient mice. In Caucasian SLE families, this GT repeat polymorphism was rare. CD19 mRNA level in the isolated peripheral blood B lymphocytes was lower in individuals possessing (GT)(15-18) alleles compared with those without these alleles, both in controls and in SLE patients; however, the difference did not reach statistical significance. These results suggested that either the slight reduction in the CD19 mRNA level associated with the elongation of GT repeat, or an allele of another locus in linkage disequilibrium with CD19 (GT)(15-18), may be associated with susceptibility to SLE in Japanese.