Search

A new catalyst: diatomite supported binary transition metal sulfates (Fe2(SO4)3 and Zr(SO4)2) was prepared. It exhibited excellent catalytic activity in the synthesis of biodiesel from waste fatty acids (conversion close to 100%).

The combination of a solar array and a communication antenna can reduce the entire mass, physical size, and cost in space applications. Currently, related studies mainly focus on the combination of the two structures on one flat plate structure (FPS). Compared with the FPS, a paraboloid structure has lower surface density and higher conversion efficiency. Therefore, the novel design of a space large deployable paraboloid structure with power and communication integration (SSPCI) is proposed for spacecraft on a sun synchronous earth orbit. A novel three-extensible-rod (TER) tracker is studied in detail for the SSPCI to track the sun for power in the sunshine region or turn to face the ground station for communication in the earth's shadow region. The proposed TER tracker includes three extensible rods, where one end of each rod is connected to the base platform by a rotary joint, and the other end is connected to the mobile platform by a smart compound joint as a substitute for a spherical joint; this is known in the literature as a 3-RPS parallel mechanism. In contrast to existing serial mechanisms, it provides a simple and lightweight structure, high structural stiffness, low inertia, and more accurate positioning and pointing of the mobile platform. Meanwhile, the linear extensible rods used in the TER tracker help to reduce energy consumption, and do not require the use of large and heavy speed reducers. A kinematic model of the TER tracker is also established. Based on this kinematic model, a dynamic model is then derived by using Newton–Euler formulation. The motion trajectory of the TER tracker is planned for the SSPCI to track the sun or turn to face the ground station. By setting related parameters, the workspace and pointing accuracy of the TER tracker are analyzed and found to be satisfactory for the SSPCI, and the motion process of tracking the sun or turning to face the ground station is simulated to test the theoretical analysis. The driving force and consumed energy of the TER tracker are obtained; the results shows that the TER tracker is able to drive the SSPCI to track the sun or turn to face the ground station with the aforementioned advantages and small energy consumption. By using finite element analysis, the SSPCI supported by the TER tracker is found to have satisfactory structural performance at different orientations in a zero gravity state. Meanwhile, the TER tracker has a satisfactory operation life and can adapt well to the space thermal environment. Finally, preliminary sun tracking experiments on the TER tracker are performed on the ground successfully, indirectly proving its feasibility of the TER tracker from the mechanism principle and control mode in space applications.

The phosphorescence of BODIPY dyes was observed directly in glassy solvent matrix at 78 K. The phosphorescence occurred when Br substituents are present on the BODIPY core and the solvent temperature is lower than the freezing point. The phosphorescence quantum yield (Φp) and lifetime (τp) were measured. The substitution effect of Br atoms on the phosphorescence properties of 8-phenyl-BODIPY dyes is also studied. Upon the increase in the number of Br atoms on the BODIPY core, the phosphorescence emission maximum is varied from 720 to 780 nm, the corresponding excited triplet state energy changes from 1.71 to 1.62 eV, the lifetime τp is shortened from 5.8 to 3.7 ms, while the quantum yield Φp is decreased from 3.0 × 10−3 to 1.4 × 10−3. The mechanism for the effect of Br substitution on the phosphorescence properties is revealed by calculating the rate constants of related photophysical processes. The Br substitution at position 1 or 7 showed a dramatic difference from that at positions 2, 6, 3, and 5. The steric hindrance to the rotation of the phenyl leads to the deformation of BODIPY π-core such that the phosphorescence properties change toward a different direction.

Experiment was conducted at the Gongzhuling Experimental Station of Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Jilin Province, China, during 2009–2010. Six representative varieties of maize (Baihe in the 1950s, Jidan 101 in the 1960s, Zhongdan 2 in the 1970s, Yedan 13 in the 1980s, Zhengdan 958 in the 1990s, and Xianyu 335 in the 2000s) were each planted under two different densities (52 500 and 82 500 plants ha−1) and two different nitrogen application levels (150 and 300 kg ha−1). Root characteristics and distribution among soil layers were studied by the field root digging method. The results showed that root mass increased with the process of the growth and development of the plant, and it peaked at kernel filling stage, and decreased at maturity due to the root senesces. Root mass of different maize varieties from the 1950s to 1980s had a trend of increase, while it decreased for the modern varieties. Root length and root surface areas had the similar changing trend. The study suggested that early maize varieties may have root redundancy, and reducing root redundancy may be a direction for variety improvement for high yield. Root characteristics were affected by nitrogen application level and density; modern varieties were more suitable for higher fertilizer application level and density conditions. Root characteristics distribution among soil layers decreased by an exponent equation, but the regression coefficients of different varieties were different. Though the root length density (RLD) of every soil layer of different varieties also decreased by an exponent equation, there were large variations of RLD in every part of a layer.

Ning-Kui Niu,1–3 Juan-Juan Yin,3 Yin-Xue Yang,4 Zi-Li Wang,1 Zhi-Wei Zhou,3 Zhi-Xu He,5 Xiao-Wu Chen,6 Xueji Zhang,7 Wei Duan,8 Tianxin Yang,9 Shu-Feng Zhou3 1Department of Orthopedics, General Hospital of Tianjin Medical University, Tianjin, 2Department of Spinal Surgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, People’s Republic of China; 3Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; 4Department of Colorectal Surgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, 5Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guizhou Medical University, Guiyang, Guizhou, 6Department of General Surgery, The First People’s Hospital of Shunde Affiliated to Southern Medical University, Shunde, Foshan, Guangdong, 7Research Center for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing, People’s Republic of China; 8School of Medicine, Deakin University, Waurn Ponds, VIC, Australia; 9Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, UT, USA Abstract: Tuberculosis (TB) is still a major public health issue in developing countries, and its chemotherapy is compromised by poor drug compliance and severe side effects. This study aimed to synthesize and characterize new multimodal PEGylated liposomes encapsulated with clinically commonly used anti-TB drugs with linkage to small interfering RNA (siRNA) against transforming growth factor-β1 (TGF-β1). The novel NP-siRNA liposomes could target THP-1-derived human macrophages that were the host cells of mycobacterium infection. The biological effects of the NP-siRNA liposomes were evaluated on cell cycle distribution, apoptosis, autophagy, and the gene silencing efficiency of TGF-β1 siRNA in human macrophages. We also explored the proteomic responses to the newly synthesized NP-siRNA liposomes using the stable isotope labeling with amino acids in cell culture approach. The results showed that the multifunctional PEGylated liposomes were successfully synthesized and chemically characterized with a mean size of 265.1 nm. The novel NP-siRNA liposomes functionalized with the anti-TB drugs and TGF-β1 siRNA were endocytosed efficiently by human macrophages as visualized by transmission electron microscopy and scanning electron microscopy. Furthermore, the liposomes showed a low cytotoxicity toward human macrophages. There was no significant effect on cell cycle distribution and apoptosis in THP-1-derived macrophages after drug exposure at concentrations ranging from 2.5 to 62.5 µg/mL. Notably, there was a 6.4-fold increase in the autophagy of human macrophages when treated with the NP-siRNA liposomes at 62.5 µg/mL. In addition, the TGF-β1 and nuclear factor-κB expression levels were downregulated by the NP-siRNA liposomes in THP-1-derived macrophages. The Ingenuity Pathway Analysis data showed that there were over 40 signaling pathways involved in the proteomic responses to NP-siRNA liposome exposure in human macrophages, with 160 proteins mapped. The top five canonical signaling pathways were eukaryotic initiation factor 2 signaling, actin cytoskeleton signaling, remodeling of epithelial adherens junctions, epithelial adherens junction signaling, and Rho GDP-dissociation inhibitor signaling pathways. Collectively, the novel synthetic targeting liposomes represent a promising delivery system for anti-TB drugs to human macrophages with good selectivity and minimal cytotoxicity. Keywords: tuberculosis, cytokine, liposome, apoptosis, autophagy, cell cycle, proteomics, SILAC, NF-κB, interleukin

Quantifying spatial patterns of species richness and determining the processes that give rise to these patterns are core problems in biodiversity theory. The aim of the present paper was to more accurately detect patterns of vascular species richness at different scales along altitudinal gradients in order to further our understanding of biodiversity patterns and to facilitate studies on relationships between biodiversity and environmental factors. Species richness patterns of total vascular plants species, including trees, shrubs, and herbs, were measured along an altitudinal gradient on one transect on a shady slope in the Dongling Mountains, near Beijing, China. Direct gradient analysis, regression analysis, and geostatistics were applied to describe the spatial patterns of species richness. We found that total vascular species richness did not exhibit a linear pattern of change with altitude, although species groups with different ecological features showed strong elevational patterns different from total species richness. In addition to total vascular plants, analysis of trees, shrubs, and herbs demonstrated remarkable hierarchical structures of species richness with altitude (i.e. patchy structures at small scales and gradients at large scales). Species richness for trees and shrubs had similar spatial characteristics at different scales, but differed from herbs. These results indicated that species groups with similar ecological features exhibit similar biodiversity patterns with altitude, and studies of biodiversity based on species groups with similar ecological properties or life forms would advance our understanding of variations in species diversity. Furthermore, the gradients or trends appeared to be due mainly to local variations in species richness means with altitude. We also found that the range of spatial scale dependencies of species richness for total vascular plants, trees, shrubs, and herbs was relatively large. Thus, to detect the relationships between species richness with environmental factors along altitudinal gradients, it was necessary to quantify the scale dependencies of environmental factors in the sampling design or when establishing non-linear models. (Managing editor: Ya-Qin Han)

In this study, we develop a novel one-step method for synthesis of nickel oxide/silicon dioxide (NiO/SiO(2)) mesoporous composites by using N-hexadecyl ethylenediamine triacetate (HED3A) as structure-directing agent. Besides playing a role in directing the mesophase formation, the anionic surfactant also functions as a chelating agent that binds nickel ions. Ultraviolet-visible (UV-vis) and Fourier transform infrared (FTIR) spectroscopic analyses were undertaken to determine the chelating ability between HED3A and nickel ions. By adjusting the molar ratio of Ni(2+)/HED3A in the template solution, a series of mesoporous composites with various NiO contents were obtained after calcination. These composites were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and nitrogen adsorption/desorption. The results showed that the generated NiO nanoparticles were aggregated into clusters with the size less than 20 nm, and the composites retained mesoporous characteristics even with high NiO contents. HRTEM images also revealed the migration and aggregation for NiO nanoparticles during the sintering process. Moreover, the energy-dispersive X-ray spectrum (EDX) results showed a close linear relationship between Ni/Si in the composites and Ni(2+)/HED3A in the templates. This chelating surfactant-assistant encapsulation route has the potential to synthesize diversiform metal oxide/silica mesoporous composites with designated compositions.

Ning-Kui Niu,1–3 Zi-Li Wang,1 Shu-Ting Pan,2,4 Hui-Qiang Ding,1 Giang HT Au,2 Zhi-Xu He,5 Zhi-Wei Zhou,2,5 Guozhi Xiao,6 Yin-Xue Yang,7 Xueji Zhang,8 Tianxin Yang,9 Xiao-Wu Chen,10Jia-Xuan Qiu,4 Shu-Feng Zhou2 1Department of Spinal Surgery, General Hospital of Ningxia Medical University, Yinchuan, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; 3Department of Orthopedics, General Hospital of Tianjin Medical University, Tianjin, 4Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 5Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guizhou Medical University, Guiyang, Guizhou, People’s Republic of China; 6Department of Biochemistry, Medical Center, Rush University, Chicago, IL, USA; 7Department of Colorectal Surgery, General Hospital of Ningxia Medical University, Yinchuan, 8Research Center for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing, People’s Republic of China; 9Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, UT, USA; 10Department of General Surgery, The First People’s Hospital of Shunde affiliated to Southern Medical University, Foshan, Guangdong, People’s Republic of China Abstract: Osteosarcoma (OS) is the most common malignant bone tumor occurring mostly in children and adolescents between 10 and 20 years of age with poor response to current therapeutics. Alisertib (ALS, MLN8237) is a selective Aurora kinase A inhibitor that displays anticancer effects on several types of cancer. However, the role of ALS in the treatment of OS remains unknown. This study aimed to investigate the effects of ALS on the cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition (EMT) and the underlying mechanisms in two human OS cell lines U-2 OS and MG-63. The results showed that ALS had potent growth inhibitory, pro-apoptotic, pro-autophagic, and EMT inhibitory effects on U-2 OS and MG-63 cells. ALS remarkably induced G2/M arrest and down-regulated the expression levels of cyclin-dependent kinases 1 and 2 and cyclin B1 in both U-2 OS and MG-63 cells. ALS markedly induced mitochondria-mediated apoptosis with a significant increase in the expression of key pro-apoptotic proteins and a decrease in main anti-apoptotic proteins. Furthermore, ALS promoted autophagic cell death via the inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase (p38 MAPK) signaling pathways, and activation of 5'-AMP-dependent kinase (AMPK) signaling pathway. Inducers or inhibitors of apoptosis or autophagy simultaneously altered ALS-induced apoptotic and autophagic death in both U-2 OS and MG-63 cells, suggesting a crosstalk between these two primary modes of programmed cell death. Moreover, ALS suppressed EMT-like phenotypes with a marked increase in the expression of E-cadherin but a decrease in N-cadherin in U-2 OS and MG-63 cells. ALS treatment also induced reactive oxygen species (ROS) generation but inhibited the expression levels of sirtuin 1 and nuclear factor-erythroid-2-related factor 2 (Nrf2) in both cell lines. Taken together, these findings show that ALS promotes apoptosis and autophagy but inhibits EMT via PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways with involvement of ROS- and sirtuin 1-associated pathways in U-2 OS and MG-63 cells. ALS is a promising anticancer agent in OS treatment and further studies are needed to confirm its efficacy and safety in OS chemotherapy. Keywords: ALS, autophagy, apoptosis, osteosarcoma, PI3K/Akt/mTOR pathway, EMT