Daryoosh Vashaee

Bio: Daryoosh Vashaee is an academic researcher from North Carolina State University. The author has contributed to research in topics: Thermoelectric effect & Thermoelectric materials. The author has an hindex of 48, co-authored 225 publications receiving 15724 citations. Previous affiliations of Daryoosh Vashaee include University of California, Santa Cruz & Oklahoma State University–Tulsa.

Growth factors for oral and maxillofacial regeneration applications

Abstract: A literature survey was conducted to examine the available information on the potential of growth factors (GFs) for maxillofacial regeneration applications. The goal of this chapter is to evaluate the biological nature of the GFs, their molecular level of activity and their osteogenic potential in maxillofacial regeneration. All the GFs examined in this study have a crucial role in human growth and development. Insulin-like growth factors (IGFs) have a vital role in general growth and maintenance of the body keleton. In postnatal skeletal regeneration, platelet-derived growth factor (PDGF) plays a fundamental role in the inducing proliferation of the undifferentiated mesenchymal cells. It is also an effective mediator for bone healing and regeneration during trauma and infection. The cooperation of IGF-I with PDGF has been beneficial in encouraging bone regeneration in maxillofacial defects. Transforming growth factor beta (TGF-β) in maxillofacial reconstruction, however, seems to be associated with uncertain results. The presence of committed cells is needed for stimulating bone creation by TGF-β. It has a biphasic influence, which represses proliferation and osteoblastic differentiation at high concentrations. Bone morphogenic proteins (BMPs) seem to be the most impactful GFs with regard to maxillofacial defect repair. The effectiveness of BMPs for maxillofacial defect repair is greatly dependent on the type of carrier, and because of this, has been subjected to unknown factors in the clinical possibility trials, leading to unclear results.

Nanobiomaterials in periodontal tissue engineering

Abstract: Periodontitis is an inflammatory disease of the gums which spreads and affects the supporting tooth structures possibly leading to the loosening and loss of the tooth. Periodontal tissue engineering is considered a relatively new technique for the stimulation of the periodontal tissue formation using the basics of regenerative medicine. In this method, biodegradable porous scaffolds are employed as a temporary substitution of the injured or lost tissues to facilitate the regeneration process. Scaffolds are usually made of natural or synthetic polymers and ceramics doped with various nanobiomaterials for an intended functionalization. The addition of nanoparticles into the scaffold structure not only enhances the biomineralization potential of the composite scaffolds, but also improves their mechanical properties. Nanosized ceramic particles are of special importance as they mimic the mineral crystal structure of the natural tissues. They have been demonstrated to induce a considerable enhancement in the protein absorption and the cell adhesion compared to their micro-sized counterparts. This chapter reviews different nanobiomaterials employed in periodontal tissue engineering for the effective regeneration of lost tissues and discuss their benefits and drawbacks.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Complex thermoelectric materials.

Abstract: Thermoelectric materials, which can generate electricity from waste heat or be used as solid-state Peltier coolers, could play an important role in a global sustainable energy solution. Such a development is contingent on identifying materials with higher thermoelectric efficiency than available at present, which is a challenge owing to the conflicting combination of material traits that are required. Nevertheless, because of modern synthesis and characterization techniques, particularly for nanoscale materials, a new era of complex thermoelectric materials is approaching. We review recent advances in the field, highlighting the strategies used to improve the thermopower and reduce the thermal conductivity.