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In this study, we aim to explore the effects of short hairpin RNAs (shRNAs) targeting human telomerase reverse transcriptase (hTERT) on the proliferation and apoptosis of osteosarcoma cells. After the synthesis of shRNA that target hTERT, osteosarcoma cells were assigned into three experimental groups—shRNA group, scramble group and blank group. The transcription and expressions of the hTERT gene in transfected cells were measured with quantitative real-time polymerase chain reaction and western blotting. Cell proliferation in each group was detected by Cell Counting Kit-8 assay. Cell cycle and rates of apoptosis were measured by flow cytometry. Expressions of apoptosis-related proteins, caspase-9 and caspase-3, were detected by western blotting. Telomerase activity was measured by PCR enzyme-linked immunosorbent assay. Results show that both the mRNA and protein expressions of hTERT were significantly lowered after the transfection of hTERT-shRNA. The proliferation capacity of transfected osteosarcoma MG-63, SaOS2 and U2OS cells in the shRNA group was lower than that in the blank group. We also found changes and differences in the amount of cells throughout the cell cycle. All cells in the G0/G1 phase increased in numbers, whereas the number of cells in the S phase were reduced, with elevated apoptosis rates. Expressions of apoptosis-related proteins, caspase-9 and caspase-3, were increased and telomerase activity was decreased in the transfected shRNA group (all P<0.05). Our results showed that shRNA targeting of the hTERT gene was able to inhibit cell proliferation and promote apoptosis of osteosarcoma cells by reducing the telomerase activity.

PurposeTo develop a hyaluronan hydrogel scaffold-based xeno-free culture system for ex vivo cultivation of human corneal epithelial stem cells (CESCs).Patients and MethodsCESCs were cultivated from donor limbal explants on the HyStem-C Hydrogel bio-scaffold in 12-well plates for 3 weeks. Group A used the traditional supplemented hormonal epidermal medium (SHEM) and group B used the defined SHEM (without fetal bovine serum and toxin A, adding 20% serum replacement). The growth and morphology of the cultured cells were assessed by phase contrast microscope. The expressions of specific cell markers were assessed by immunofluorescence staining and quantitative real-time PCR (qRT-PCR).ResultsSuccessful cultures of CESCs were obtained in both groups, resulting in multilayered stratified epithelia. Comparing to group A, the cells in group B was grown slightly slower and formed less cellular layers at the end of culture. The corneal specific cytokeratin (K) 12 and differentiation markers, involucrin, and connexin 43, were mainly expressed in the superficial cellular layers in both groups. Interestingly, certain basal cells were immune-positive to proposed stem cell markers such as K19, ABCG2, and integrin β1 in both groups. There was no significant difference between the two groups with regard to the gene expression levels of all these selected corneal markers (all P>0.05).ConclusionsThe hyaluronan hydrogel scaffold-based xeno-free culture system may support the expansion of regenerative CESCs without the risk of xeno component contamination. The regenerated epithelium maintains similar characteristics of native corneal epithelium.

A new dieless forming method is proposed to produce metal bellows induced by local thermal buckling. The thermal buckling forming process is realized according to the local deformation behavior of metal tubes under the action of high temperature softening and axial pressure. In this paper, a forming device is designed and it is capable to produce metal bellows in two forming modes of a discontinuous bellow forming process and a continuous bellow forming process. FEM simulations are used to analyze this thermal buckling forming process and its product performance. The results show that the presented process can increase wall thickness and improve the energy absorption performance of metal bellows. Meanwhile, some thermal buckling forming cases of metal bellows of different materials and different sizes are presented.

Disruption of the intricate gene expression program represents one of major driving factors for the development, progression and maintenance of human cancer, and is often associated with acquired therapeutic resistance. At the molecular level, cancerous phenotypes are the outcome of cellular functions of critical genes, regulatory interactions of histones and chromatin remodeling complexes in response to dynamic and persistent upstream signals. A large body of genetic and biochemical evidence suggests that the chromatin remodelers integrate the extracellular and cytoplasmic signals to control gene activity. Consequently, widespread dysregulation of chromatin remodelers and the resulting inappropriate expression of regulatory genes, together, lead to oncogenesis. We summarize the recent developments and current state of the dysregulation of the chromatin remodeling components as the driving mechanism underlying the growth and progression of human tumors. Because chromatin remodelers, modifying enzymes and protein–protein interactions participate in interpreting the epigenetic code, selective chromatin remodelers and bromodomains have emerged as new frontiers for pharmacological intervention to develop future anti-cancer strategies to be used either as single-agent or in combination therapies with chemotherapeutics or radiotherapy.

ABSTRACTIris germanicaL. is a popular perennial flower worldwide, but its use is limited in China due to an inadequate availability of propagules. To accelerate rhizome growth and lateral bud production using plant growth retardants (PGRs), chlorocholine chloride (CCC; at 1,500 or 3,000 mg l−1) or prohexadione-Ca (at 700 or 1,500 mg l−1) were applied to uniform plants of I. germanica. Time-course measurements of changes in morphogenesis, carbohydrate metabolism, total soluble protein (TSP) concentrations, and endogenous phytohormone concentrations in rhizomes were conducted to test the efficacy of CCC or prohexadione-Ca for increasing rhizome growth and lateral bud production. The results showed that both PGRs increased the fresh weights of rhizomes at 2, 4, and 6 weeks after treatment (WAT). Overall, 700 mg l−1prohexadione-Ca was most effective at promoting the formation of lateral buds which increased by 183.5% at 12 WAT relative to untreated control plants. Concentrations of sucrose and starch in PGR-treated rhizomes increased at 2, 4, and 6 WAT, while a decline was observed by 12 WAT. TSP concentrations increased during rhizome enlargement, then decreased during lateral bud germination after prohexadione-Ca treatment. In general, concentrations of endogenous phytohormones, such as gibberellins, indole-3-acetic acid, jasmonic acid, and zeatin riboside, decreased significantly in rhizomes at 4 WAT, then increased at 12 WAT. Our study indicated that prohexadione-Ca promoted rhizome growth and the accumulation of sucrose and starch before summer dormancy, then significantly accelerated the production of lateral buds.

Flower-like hierarchical Au/NiAl-LDH catalysts were synthesized for selective oxidation of alcohols. The abundant hydrogen vacancies at the edge of the flowers as nucleation centers contributed to the uniform dispersion of Au NPs. The confinement effect of the hierarchical pores promoted 60% higher activity than the common Au/NiAl-LDH nanoparticle catalyst in the oxidation of benzyl alcohol by heightening the effective collisions between substrates and active sites. The evolution process of the hierarchical pores in the support was further proposed. Moreover, the reaction mechanism of the cooperation among Brønsted base sites, NiIIIcoordinatively unsaturated metal sites and isolated gold cations was concretely proved. In the oxidation of other typical alcoholic substrates, the flower-like catalyst showed higher activity than the common nanoparticle one except for linear alcohols, which could be attributed to the shape selectivity of straight macropores.

NiTi-layered double hydroxide (NiTi-LDH) with rich defective sites was synthesized and used as the support for the preparation of a novel supported PdAg nanoalloy catalyst for the partial hydrogenation of acetylene. The obtained PdAg/NiTi-LDH catalyst exhibited a remarkable catalytic performance. When the conversion of acetylene reached 90%, the selectivity towards ethene maintained 82%. Superior hydrogenation activity was ascribed to two key factors. Small particle size and high dispersion of PdAg nanoparticles were responsible for boosting the catalytic activity. In addition, Ti3+defective sites in the support also played an important role in the enhancement of activity. The interface at the Ti3+species and active metals acting as new active sites enhanced the activation and dissociation of hydrogen and therefore further improved the catalytic activity. Preferable selectivity was assigned to the electronic effect between the NiTi-LDH support and the PdAg nanoalloys. The electron transfer from the Ti3+species to the Pd resulted in the increase of electron density and the linearly coordinated sites of Pd and therefore facilitated the desorption of ethene. Moreover, due to the reducibility of NiTi-LDH, the selectivity and stability over the reduced PdAg/NiTi-LDH catalyst were further enhanced on account of the strong metal–support interaction.

High strength and toughness are of importance for composite plastics used as mechanical structure parts. How to provide general and engineering plastics with high performances is one of the critical challenges in advanced manufacturing. In the past decade, the phase dispersion, interfacial interaction, injection molding simulation and fracture behaviors of composite plastics were investigated systematically in our research group in order to simultaneously reinforce and toughen polymer matrix. Here, we review the progress and advances which have been made in the above items.

A total of 260 surface soil samples were collected to investigate the spatial distribution of trace metals in Guangdong province, one of the fast developing regions in China. The results show that the upper baseline concentrations of Cu, Pb, Zn, Cd, Ni, Cr, and Hg were 28.7, 57.6, 77.8, 0.13, 23.5, 87.0, and 0.15 mg kg−1, respectively. Regional parent materials and pedogenesis are the primary factors influencing the concentrations of trace metals, and various anthropogenic activities are the second most important factors. The spatial distribution of trace metals is correlated to the geological characters with high concentrations of trace metals always located in regional fault areas, basins, and the Pearl River Delta alluvial plain and to the low concentrations associated with the other areas in Guangdong province.

Using the layer-by-layer self-assembly technique, we have deposited multilayer thin films on conductive indium tin oxide (ITO) surfaces by alternatively dipping ITO substrates in a polymer PDDA or poly(diallydimethylammonium) chloride solution and a macrocyle NiPc or nickel phthalocyanine solution. In addition to characterizing PDDA-NiPc systems with X-ray reflectometry and cyclic voltammetry, we monitored the growth of PDDA/NiPc multilayers on conductive oxides with Fourier transform infrared (IR) spectroscopy at an external grazing-angle reflection configuration. IR spectra with polarization perpendicular to the conductive ITO surfaces revealed vibration bands at 1227 and 1200 cm^-1 corresponding to salt bridges of −SO3^-··· Me2N⁺&dbd; binding between PDDA and NiPc. An oscillation of the surface electronic potential was observed with a Kelvin Probe as the surface layer alternated between PDDA and NiPc. The average gap of the surface potential difference between NiPc and PDDA monolayers is about 400 mV. Oscillation of surface potential or work function is caused by the modulation in electron affinity of ITO due to the dipolar effect generated by the highly charged layers of PDDA or NiPc.

Nonlinear second harmonic generation (SHG), second harmonic microscopy (SHM), and infrared spectroscopy are used to determine the structural and optical properties of the Langmuir−Blodgett (LB) monolayer assemblies of NLO-active, 4-eicosyloxo-(E)-stilbazolium iodide (4-EOSI) on a glass substrate. The packing characteristics of the pretransferred interfacial films are determined using π−A isotherm measurements. The molecular coverage of the transferred films is determined by ellipsometry. The films formed on both sides of the glass substrate show substantial second harmonic (SH) conversion from p-polarized 1064 nm fundamental excitation. The SHG and FTIR measurements imply that the single LB layer on glass is composed of oriented clusters of 4-EOSI molecules that are laterally discontinuous. Ordered clusters up to 40 μm in diameter are directly observed using SHM. Subsequent LB transfers using the same 4-EOSI molecule or an amphiphile of comparable chain-length (eicosanoic acid) fill in the unoccupied vacancies in the first layer. The magnitude of the dominant element of the nonlinear susceptibility and the average molecular orientation angle of the chromophore are determined by modeling the characteristic SHG Maker fringes.

ABSTRACTHigh Performance Centrifugal Partition Chromatography (HPCPC) is a practical and suitable method, particularly on the preparative scale, for the separation of biomolecules such as proteins, enzymes, etc. Aqueous two-phase system is also very attractive for the isolation of biomolecules. Aqueous polymer phase system composed of polyethylene glycol 6000-potassium phosphate has been used for the countercurrent chromatographic separation of bovine serum albumin (BSA) and lysozyme using HPCPC. The separation of BSA and lysozyme under various conditions such as various flow rates, rotational speeds, pH of the solvent, and the retention of stationary phase has been studied in the present investigation. The baseline separation of BSA and lysozyme has been also observed. The results of this study demonstrate that HPCPC is useful for separation of proteins with aqueous two-phase systems.

We have labelled precursor cells in the embryonic rat cerebral cortex using BAG, a retroviral vector that expresses beta-galactosidase. We had previously reported that labelled precursor cells generate clusters of labelled cells that could be classified into four types by their morphological appearance and anatomical distribution (Price and Thurlow, 1988). In this study, we have used immunohistochemistry and intracellular dye labelling to identify the cell types that make up these clusters. We discovered that clusters are almost always composed of a single cell type. In addition to clusters composed entirely of neurones, we found four different types of glial cell clusters. In the grey matter, glial clusters are composed either of protoplasmic astrocytes, or of cells that have an astrocyte morphology, but no glial filaments. In the white matter, clusters are composed of either fibrous astrocytes or oligodendocytes. Our results indicate that each of these different cortical cell types is generated from a separate population of precursor cells.

Electrical resistivity of soil has become one of the most important indicators of compactness and compressive resistance. In previous studies, the temperature of soil tested was always above 0 °C. However, due to the phase change of pore water, the resistivity of freezing soils is different from that of unfrozen soils. Therefore, it is necessary to clarify the influence of temperature on electrical resistivity. To achieve this goal, according to the bundle of the cylindrical capillary model, pores in soil were treated as conducting tubes, and two simple lognormal functions were introduced to describe the distribution of the conducting tubes. Based on the conductivity theory, a new model considering the temperature and the pore size distribution was presented. Results show that only a part of the conducting tubes can be treated as the effective conducting tubes, which are determined by the soil temperature. Furthermore, a small portion of the pores with the smaller size controlled the electrical resistivity of the freezing clay. In other words, the change in the electrical resistivity of freezing clay was caused mainly by the change of unfrozen water content through the decrease in temperature. Based on the experimental results conducted on clay from Northeast China, the validity of the presented model was verified. The comparison results indicate that there was a good agreement between the calculated results and the experimental results. To expand the scope of the model, more laboratory tests are suggested to conduct to verify the applicability of the model to other clays. The resistivity of freezing soil depends on the unfrozen water content which controlled by temperatureSmall portion of pore water with smaller size controls the electrical resistivity of freezing clayA resistivity model with the consideration of pore size distribution and temperature is presented

Using a laser monitoring observation technique, solid−liquid equilibria in the systems benzoic acid + p-toluic acid + chloroform at 303.15 K, benzoic acid + p-toluic acid + acetic acid at 343.15 K, and terephthalic acid + isophthalic acid + N,N-dimethylformamide at 343.15 K have been investigated. The solid−liquid equilibrium phase diagrams for the three systems are plotted on the basis of the experimental data obtained.

The paper develops a position synchronization controller for a new active/active dual redundant electro-mechanical actuation system and designs a test platform to validate the performance of the controller. The mathematic models of the position synchronization system are firstly built based on the schematic of the active/active dual redundant electro-mechanical actuation system. The position controller for DEMA and GEMA of is developed based on the velocity and acceleration feed forward and traditional PID theory. A series of motion experiments are carried out to verify the effectiveness of the controller design for active/active dual redundant electro-mechanical actuation system. The experiments results show that the position controllers designed for either DEMA or GEMA are satisfied, the biggest following error is not more than 0.1mm. And the synchronous motion tests show that the PI plus Output Saturation feedback position synchronization control can reduce more than 30 percent synchronous position errors. Furthermore, the tests of position synchronization show that EMA stiffness has a big influence on the synchronous precision. The new position synchronization controller designed based on the accurate system model and actual system parameters can better achieve the position synchronization requirements of the dual redundant EMA system, which makes good sense for redundant systems.

Solubilities of terephthalaldehydic acid in water, acetic acid, chloroform, N, N-dimethylformamide, and N-methyl-2-pyrrolidone were determined by a static analytical method at temperatures ranging from 293.15 K to 371.15 K at atmospheric pressure. The Buchowski equation was used to correlate the solubility data with standard deviations in the range 0.006−3.438 g of terephthalaldehydic acid/100 g of solvent.