Iron phosphide nanostructures produced from a single-source organometallic precursor: nanorods, bundles, crosses, and spherulites

Single-source molecular precursors were found to produce iron phosphide materials. In a surfactant system of trioctylamine and oleic acid, H2Fe3(CO)9PtBu reacted to form Fe4(CO)12(PtBu)2, which decomposed to give Fe2P nanorods and "bundles." Control of the morphology obtained was possible by varying the surfactant system; addition of increasing amounts of oleic acid resulted in crystal splitting, while the addition of microliter amounts of an alkane enhanced the crystal splitting to give sheaflike structures. The different morphologies seen were attributed to imperfect crystal growth mechanisms.     

Alignment of a conjugated polymer onto amyloid-like protein fibrils

The amyloid-like fibril is a biomolecular nanowire template of very high stability. Here we describe the coordination of a conjugated polyelectrolyte, poly(thiophene acetic acid) (PTAA), to bovine insulin fibrils with widths of <10 nm and lengths of up to more than 10 microm. Fibrils complexed with PTAA are aligned on surfaces through molecular combing and transfer printing. Single-molecule spectroscopy techniques are applied to chart spectral variation in the emission of these wires. When these results are combined with analysis of the polarization of the emitted light, we can conclude that the polymer chains are preferentially aligned along the fibrillar axis.     

A patterned anisotropic nanofluidic sieving structure for continuous-flow separation of DNA and proteins

Microfabricated regular sieving structures hold great promise as an alternative to gels to improve the speed and resolution of biomolecule separation. In contrast to disordered porous gel networks, these regular structures also provide well defined environments ideal for the study of molecular dynamics in confining spaces. However, the use of regular sieving structures has, to date, been limited to the separation of long DNA molecules, however separation of smaller, physiologically relevant macromolecules, such as proteins, still remains a challenge. Here we report a microfabricated anisotropic sieving structure consisting of a two-dimensional periodic nanofluidic filter array. The designed structural anisotropy causes different-sized or -charged biomolecules to follow distinct trajectories, leading to efficient separation. Continuous-flow size-based separation of DNA and proteins, as well as electrostatic separation of proteins, was achieved, demonstrating the potential use of this device as a generic molecular sieving structure for an integrated biomolecule sample preparation and analysis system.     

Use of Sacrificial Piles as Pier Scour Countermeasures

Laboratory studies on the use of sacrificial piles as a pier scour countermeasure are reported. Sacrificial piles, which previous studies have shown to result in significant scour depth reductions under clear-water conditions, were found to be rather less effective under live-bed conditions due to the passage of bed forms. Sacrificial piles are not recommended unless the flow remains aligned and the flow intensity is relatively small.     

中国西部主要盆地油气形成特征

中国西部盆地（塔里木、准噶尔、吐哈、柴达木）有古生代海相和中、新生代陆相多种成油体系,克拉通内古隆起及其斜坡和前陆盆地是大中型油气田富集区。侏罗系煤系地层煤、泥岩均能生烃,富油又富气,形成自生自储式油气藏和下生上储的次生气藏。凹陷带强烈沉降,烃源岩厚,油气形成多阶连续。多期构造运动促使西部盆地油气为多次运移、多期成藏及晚期成藏。     

Road to Metastasis: The TWEAK Pathway as a Discriminant between Metastasizing and Non-Metastasizing Thick Melanomas

Cutaneous melanoma (CM) is the most aggressive form of skin cancer, and its worldwide incidence is rapidly increasing. Early stages can be successfully treated by surgery, but once metastasis has occurred, the prognosis is poor. However, some 5–10% of thick (≥2 mm) melanomas do not follow this scenario and run an unpredictable course. Little is known about the factors that contribute to metastasis in some patient with thick melanomas and the lack thereof in thick melanoma patients who never develop metastatic disease. We were therefore interested to study differential gene expression and pathway analysis and compare non-metastatic and metastatic thick melanomas. We found that the TNF-like weak inducer of apoptosis (TWEAK) pathway was upregulated in thick non-metastasizing melanomas. MAP3K14 (NIK1), BIRC2 (cIAP1), RIPK1, CASP7, CASP8, and TNF play an important role in inhibiting proliferation and invasion of tumor cells via the activation of the non-canonical NF-κB signaling pathway. In particular, this pathway sensitizes melanoma cells to TNF-alpha and activates the apoptosis module of the TWEAK pathway in thick non-metastasizing melanomas. Hence, our study suggests a potential role of the TWEAK pathway in inhibiting thick melanoma from metastasis. Exploitation of these genes and the pathway they control may open future therapeutic avenues.     

Pseudomonas Phage MD8: Genetic Mosaicism and Challenges of Taxonomic Classification of Lambdoid Bacteriophages

Pseudomonas phage MD8 is a temperate phage isolated from the freshwater lake Baikal. The organisation of the MD8 genome resembles the genomes of lambdoid bacteriophages. However, MD8 gene and protein sequences have little in common with classified representatives of lambda-like phages. Analysis of phage genomes revealed a group of other Pseudomonas phages related to phage MD8 and the genomic layout of MD8-like phages indicated extensive gene exchange involving even the most conservative proteins and leading to a high degree of genomic mosaicism. Multiple horizontal transfers and mosaicism of the genome of MD8, related phages and other λ-like phages raise questions about the principles of taxonomic classification of the representatives of this voluminous phage group. Comparison and analysis of various bioinformatic approaches applied to λ-like phage genomes demonstrated different efficiency and contradictory results in the estimation of genomic similarity and relatedness. However, we were able to make suggestions for the possible origin of the MD8 genome and the basic principles for the taxonomic classification of lambdoid phages. The group comprising 26 MD8-related phages was proposed to classify as two close genera belonging to a big family of λ-like phages.     

反应挤出合成SIS三嵌段共聚物的研究

研究了以同向紧密啮合双螺杆挤出机为反应器,采用单体顺序加料方式,本体法合成SIS三嵌段共聚物。^1H—NMR谱图表明该共聚物的结构为嵌段结构。异戊二烯的质量分数影响其力学性能。     

梳状聚苯乙烯-聚二甲基硅氧烷共聚物的合成及表征

通过苯乙烯与聚二甲基硅氧烷大单体进行自由基聚合反应,合成了梳状聚苯乙烯-聚二甲基硅氧烷共聚物.结果表明,侧链聚二甲基硅氧烷的相对分子质量越大,梳状聚苯乙烯-聚二甲基硅氧烷共聚物的相分离程度越明显,其热稳定性与聚苯乙烯相比有一定程度的提高.     

Optimization of edible Alyssum homalocarpum seed gum-chitosan coating formulation to improve the postharvest storage potential and quality of apricot (Prunus armeniaca L.)

Edible coating based on Alyssum homalocarpum seed gum (AHSG) and chitosan for coating of fresh apricot was optimized using response surface methodology (RSM). The independent variables included concentrations of AHSG and chitosan in coating solution. The response variables studied were total soluble solid, weight loss, titratably acidity, pH, reducing sugar, moisture content, and firmness. Results indicated that RSM models were significantly (p < .05) qualified for all response variables, except for total soluble solid and titratable acidity. The regression models demonstrated R² ranging from .78 to .99. AHSG concentration influenced the weight loss, pH, and firmness, while chitosan concentration had an effect on pH and moisture content. This study showed that the coating can improve apricot firmness and stability in terms of weight loss, pH, and moisture content. The study suggested that a combination of AHSG 1.02% (w/w) and chitosan 0.33% (w/w) is the best one to achieve the desirable responses.