Dimerization-Induced Fermi-Surface Reconstruction in IrTe2

We report a de Haas-van Alphen (dHvA) oscillation study on IrTe2 single crystals showing complex dimer formations. By comparing the angle dependence of dHvA oscillations with band structure calculations, we show distinct Fermi surface reconstruction induced by a 1/5-type and a 1/8-type dimerizations. This verifies that an intriguing quasi-two-dimensional conducting plane across the layers is induced by dimerization in both cases. A phase transition to the 1/8 phase with higher dimer density reveals that local instabilities associated with intra-and interdimer couplings are the main driving force for complex dimer formations in IrTe2.X11149sciescopu

Hysteretic melting transition of a soliton lattice in a commensurate charge modulation

We report on the observation of the hysteretic transition of a commensurate charge modulation in IrTe2 from transport and scanning tunneling microscopy (STM) studies. Below the transition (T-C approximate to 275 K on cooling), a q = 1/5 charge modulation was observed, which is consistent with previous studies. Additional modulations [q(n) = (3n + 2)(-1)] appear below a second transition at T-S approximate to 180 K on cooling. The coexistence of various modulations persists up to T-C on warming. The atomic structures of charge modulations and the temperature-dependent STM studies suggest that 1/5 modulation is a periodic soliton lattice that partially melts below T-S on cooling. Our results provide compelling evidence that the ground state of IrTe2 is a commensurate 1/6 charge modulation, which originates from the periodic dimerization of Te atoms visualized by atomically resolved STM images.open141

MnSb2O6: a polar magnet with a chiral crystal structure

Structural and magnetic chiralities are found to coexist in a small group of materials in which they produce intriguing phenomenologies such as the recently discovered Skyrmion phases. Here, we describe a previously unknown manifestation of this interplay in MnSb2O6, a trigonal oxide with a chiral crystal structure. Unlike all other known cases, the MnSb2O6 magnetic structure is based on corotating cycloids rather than helices. The coupling to the structural chirality is provided by a magnetic axial vector, related to the so-called vector chirality. We show that this unique arrangement is the magnetic ground state of the symmetric-exchange Hamiltonian, based on ab initio theoretical calculations of the Heisenberg exchange interactions, and is stabilized by out-of-plane anisotropy. MnSb2O6 is predicted to be multiferroic with a unique ferroelectric switching mechanism.open4

Effects of gestational age at birth on cognitive performance : a function of cognitive workload demands

Objective: Cognitive deficits have been inconsistently described for late or moderately preterm children but are consistently found in very preterm children. This study investigates the association between cognitive workload demands of tasks and cognitive performance in relation to gestational age at birth. Methods: Data were collected as part of a prospective geographically defined whole-population study of neonatal at-risk children in Southern Bavaria. At 8;5 years, n = 1326 children (gestation range: 23–41 weeks) were assessed with the K-ABC and a Mathematics Test. Results: Cognitive scores of preterm children decreased as cognitive workload demands of tasks increased. The relationship between gestation and task workload was curvilinear and more pronounced the higher the cognitive workload: GA2 (quadratic term) on low cognitive workload: R2 = .02, p<0.001; moderate cognitive workload: R2 = .09, p<0.001; and high cognitive workload tasks: R2 = .14, p<0.001. Specifically, disproportionally lower scores were found for very (<32 weeks gestation) and moderately (32–33 weeks gestation) preterm children the higher the cognitive workload of the tasks. Early biological factors such as gestation and neonatal complications explained more of the variance in high (12.5%) compared with moderate (8.1%) and low cognitive workload tasks (1.7%). Conclusions: The cognitive workload model may help to explain variations of findings on the relationship of gestational age with cognitive performance in the literature. The findings have implications for routine cognitive follow-up, educational intervention, and basic research into neuro-plasticity and brain reorganization after preterm birth

Engineered mussel bioglue as a functional osteoinductive binder for grafting of bone substitute particles to accelerate in vivo bone regeneration

Xenograft bone substitutes, such as deproteinized bovine bone mineral (DBBM), have been widely employed as osteoconductive structural materials for bone tissue engineering. However, the loss of xenograft bone substitute particles in defects has been a major limitation, along with a lack of osteoinductive function. Mussel adhesive protein (MAP), a remarkable and powerful adhesive biomaterial in nature, can attach to various substrates, even in wet environments. Its adhesive and water-resistant abilities are considered to be mainly derived from the reduced catechol form, 3,4-dihydroxyphenylalanine (DOPA), of its tyrosine residues. Here, we evaluated the use of DOPA-containing MAP as a functional binder biomaterial to effectively retain DBBM particles at the defect site during in vivo bone regeneration. We observed that DOPA-containing MAP was able to bind DBBM particles easily to make an aggregate, and grafted DBBM particles were not lost in a defect in the rat calvaria during the healing period. Importantly, grafting of a DOPA-containing MAP-bound DBBM aggregate resulted in remarkably accelerated in vivo bone regeneration and even bone remodeling. Interestingly, we found that the DOPA residues in the modified MAP had an osteoinductive ability based on clear observation of the in vivo maturation of new bones with a similar bone density to the normal bone and of the in vitro osteogenic differentiation of osteoblast cells. Collectively, DOPA-containing MAP is a promising functional binder biomaterial for xenograft bone substitute-assisted bone regeneration with enhanced osteoconductivity and acquired osteoinductivity. This mussel glue could also be successfully utilized as a potential biomaterial for general bone tissue engineering.open1145sciescopu

Atomic-scale combination of germanium-zinc nanofibers for structural and electrochemical evolution

Alloys are recently receiving considerable attention in the community of rechargeable batteries as possible alternatives to carbonaceous negative electrodes; however, challenges remain for the practical utilization of these materials. Herein, we report the synthesis of germanium-zinc alloy nanofibers through electrospinning and a subsequent calcination step. Evidenced by in situ transmission electron microscopy and electrochemical impedance spectroscopy characterizations, this one-dimensional design possesses unique structures. Both germanium and zinc atoms are homogenously distributed allowing for outstanding electronic conductivity and high available capacity for lithium storage. The as-prepared materials present high rate capability (capacity of similar to 50% at 20 C compared to that at 0.2 C-rate) and cycle retention (73% at 3.0 C-rate) with a retaining capacity of 546 mAh g(-1) even after 1000 cycles. When assembled in a full cell, high energy density can be maintained during 400 cycles, which indicates that the current material has the potential to be used in a large-scale energy storage system

Accounting Problems Under the Excess Profits Tax

DNA vaccines based on subunits from pathogens have several advantages over other vaccine strategies. DNA vaccines can easily be modified, they show good safety profiles, are stable and inexpensive to produce, and the immune response can be focused to the antigen of interest. However, the immunogenicity of DNA vaccines which is generally quite low needs to be improved. Electroporation and co-delivery of genetically encoded immune adjuvants are two strategies aiming at increasing the efficacy of DNA vaccines. Here, we have examined whether targeting to antigen-presenting cells (APC) could increase the immune response to surface envelope glycoprotein (Env) gp120 from Human Immunodeficiency Virus type 1 (HIV- 1). To target APC, we utilized a homodimeric vaccine format denoted vaccibody, which enables covalent fusion of gp120 to molecules that can target APC. Two molecules were tested for their efficiency as targeting units: the antibody-derived single chain Fragment variable (scFv) specific for the major histocompatilibility complex (MHC) class II I-E molecules, and the CC chemokine ligand 3 (CCL3). The vaccines were delivered as DNA into muscle of mice with or without electroporation. Targeting of gp120 to MHC class II molecules induced antibodies that neutralized HIV-1 and that persisted for more than a year after one single immunization with electroporation. Targeting by CCL3 significantly increased the number of HIV-1 gp120-reactive CD8(+) T cells compared to non-targeted vaccines and gp120 delivered alone in the absence of electroporation. The data suggest that chemokines are promising molecular adjuvants because small amounts can attract immune cells and promote immune responses without advanced equipment such as electroporation.Funding Agencies|Research Council of Norway; Odd Fellow</p

The regulatory mechanism of fungal elicitor-induced secondary metabolite biosynthesis in medical plants.

A wide range of external stress stimuli trigger plant cells to undergo complex network of reactions that ultimately lead to the synthesis and accumulation of secondary metabolites. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Throughout evolution, endophytic fungi, an important constituent in the environment of medicinal plants, have known to form long-term stable and mutually beneficial symbiosis with medicinal plants. The endophytic fungal elicitor can rapidly and specifically induce the expression of specific genes in medicinal plants which can result in the activation of a series of specific secondary metabolic pathways resulting in the significant accumulation of active ingredients. Here we summarize the progress made on the mechanisms of fungal elicitor including elicitor signal recognition, signal transduction, gene expression and activation of the key enzymes and its application. This review provides guidance on studies which may be conducted to promote the efficient synthesis and accumulation of active ingredients by the endogenous fungal elicitor in medicinal plant cells, and provides new ideas and methods of studying the regulation of secondary metabolism in medicinal plants

Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF : the E-Freeze RCT

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