Jun Lu

Bio: Jun Lu is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Medicine & Materials science. The author has an hindex of 135, co-authored 1526 publications receiving 99767 citations. Previous affiliations of Jun Lu include Drexel University & Argonne National Laboratory.

Anti-Proliferation Potential and Content of Fucoidan Extracted from Sporophyll of New Zealand Undaria pinnatifida

Abstract: Undaria pinnatifida is a species of brown seaweed known to contain rich amounts of fucoidan, a sulphated polysaccharide known to possess various biological activities. We isolated crude fucoidan (F0) from the sporophylls of U. pinnatifida grown in the Marlborough Sounds, New Zealand. Sulphate content, uronic acid content and molecular weight of F0 were 15.02%, 1.24% and >150 kDa, respectively. F0 was fractionated to yield three further fractions: F1, F2 and F3. Cytotoxicity of two major fractions was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The algal fucoidans specifically suppressed the proliferation of three cancer cell lines with less cytotoxicity against the normal cells. Selective cytotoxicity could relate to the distinctive structures of each fucoidan fraction. Results from this study provide evidence that fucoidan, especially from U. pinnatifida grown in New Zealand, possesses great potential to be used as a functional food to reduce cancer risk or supplement cancer treatment.

The importance of anode protection towards lithium oxygen batteries

Abstract: Developing lithium oxygen (Li–O2) batteries is critical to achieve high energy density in energy storage devices. Benefiting from the low weight of the cathode reagent, oxygen, Li–O2 batteries possess a high theoretical energy density of 3500 W h kg−1 based on the formation of Li2O2. However, they face several challenges from the metal anode, the air electrode, and the unstable electrolyte. Although most studies have focused on the air electrode, the importance of the anode protection should not be neglected. In this review, we aim to understand the challenges on the lithium anode in Li–O2 batteries, which include Li dendrite growth, parasitic reactions between Li and active species in the electrolyte, and the oxygen crossover effect. Also, recent advances on the Li protection in Li–O2 batteries will be introduced. This review emphasizes the importance of anode protection especially in an oxygen rich environment and could provide guidance for future development of Li–O2 batteries.

NMR analysis of the closed conformation of syntaxin-1.

Abstract: The Sec1/Munc18 (SM) protein Munc18-1 and the SNAREs syntaxin-1, SNAP-25 and synaptobrevin form the core of the membrane fusion machinery that triggers neurotransmitter release. Munc18-1 binds to syntaxin-1 folded into a closed conformation and to the SNARE complex formed by the three SNAREs, which involves an open syntaxin-1 conformation. The former interaction is likely specialized for neurotransmitter release, whereas SM protein/SNARE complex interactions are likely key for all types of intracellular membrane fusion. It is currently unclear whether the closed conformation is highly or only marginally populated in isolated syntaxin-1, and whether Munc18-1 stabilizes the close conformation or helps to open it to facilitate SNARE complex formation. A detailed NMR analysis now suggests that the closed conformation is almost quantitatively populated in isolated syntaxin-1 in the absence of oligomerization, and indicates that its structure is very similar to that observed previously in the crystal structure of the Munc18-1/syntaxin-1 complex. Moreover, we demonstrate that Munc18-1 binding prevents opening of the syntaxin-1 closed conformation. These results support a model whereby the closed conformation constitutes a key intrinsic property of isolated syntaxin-1 and Munc18-1 binding stabilizes this conformation; in this model, Munc18-1 plays in addition an active role in downstream events after another factor(s) helps to open the syntaxin-1 conformation.

Nanoporous Ca3Co4O9 Thin Films for Transferable Thermoelectrics

Abstract: The development of high-performance and transferable thin-film thermoelectric materials is important for low-power applications, e.g., to power wearable electronics, and for on-chip cooling. Nanoporous films offer an opportunity to improve thermoelectric performance by selectively scattering phonons without affecting electronic transport. Here, we report the growth of nanoporous Ca3Co4O9 thin films by a sequential sputtering-annealing method. Ca3Co4O9 is promising for its high Seebeck coefficient and good electrical conductivity and important for its nontoxicity, low cost, and abundance of its constituent raw materials. To grow nanoporous films, multilayered CaO/CoO films were deposited on sapphire and mica substrates by rf-magnetron reactive sputtering from elemental Ca and Co targets, followed by annealing at 700 °C to form the final phase of Ca3Co4O9. This phase transformation is accompanied by a volume contraction causing formation of nanopores in the film. The thermoelectric propoperties of the nanop...

Increased miR-155-5p and reduced miR-148a-3p contribute to the suppression of osteosarcoma cell death

Abstract: Osteosarcoma (OS) is the most common cancer of bone and the 5th leading cause of cancer-related death in young adults. Currently, 5-year survival rates have plateaued at ~70% for patients with localized disease. Those with disseminated disease have an ~20% 5-year survival. An improved understanding of the molecular genetics of OS may yield new approaches to improve outcomes for OS patients. To this end, we applied murine models that replicate human OS to identify and understand dysregulated microRNAs (miRNAs) in OS. miRNA expression patterns were profiled in murine primary osteoblasts, osteoblast cultures and primary OS cell cultures (from primary and paired metastatic locations) isolated from two genetically engineered murine models of OS. The differentially expressed miRNA were further assessed by a cross-species comparison with human osteoblasts and OS cultures. We identified miR-155-5p and miR-148a-3p as deregulated in OS. miR-155-5p suppression or miR-148a-3p overexpression potently reduced proliferation and induced apoptosis in OS cells, yet strikingly, did not impact normal osteoblasts. To define how these miRNAs regulated OS cell fate, we used an integrated computational approach to identify putative candidate targets and then correlated these with the cell biological impact. Although we could not resolve the mechanism through which miR-148a-3p impacts OS, we identified that miR-155-5p overexpression suppressed its target Ripk1 (receptor (TNFRSF)-interacting serine-threonine kinase 1) expression, and miR-155-5p inhibition elevated Ripk1 levels. Ripk1 is directly involved in apoptosis/necroptosis. In OS cells, small interfering RNA against Ripk1 prevented cell death induced by the sequestration of miR-155-5p. Collectively, we show that miR-148a-3p and miR-155-5p are species-conserved deregulated miRNA in OS. Modulation of these miRNAs was specifically toxic to tumor cells but not normal osteoblasts, raising the possibility that these may be tractable targets for miRNA-based therapies for OS.

Gene set enrichment analysis: A knowledge-based approach for interpreting genome-wide expression profiles

Abstract: Although genomewide RNA expression analysis has become a routine tool in biomedical research, extracting biological insight from such information remains a major challenge. Here, we describe a powerful analytical method called Gene Set Enrichment Analysis (GSEA) for interpreting gene expression data. The method derives its power by focusing on gene sets, that is, groups of genes that share common biological function, chromosomal location, or regulation. We demonstrate how GSEA yields insights into several cancer-related data sets, including leukemia and lung cancer. Notably, where single-gene analysis finds little similarity between two independent studies of patient survival in lung cancer, GSEA reveals many biological pathways in common. The GSEA method is embodied in a freely available software package, together with an initial database of 1,325 biologically defined gene sets.

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.