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Inspired by the different pH between normal tissue and tumor tissue, pH-responsive drug release materials need to be designed to achieve drug-controlled release. Electrospinning is a simple and efficient method to fabricate drug loading and releasing materials. However, burst release of electrospun smooth fibers was often observed in drug delivery process, which is very harmful to the human body. To develop materials with drug sustained release behaviors in tumor tissue environment, different morphologies of electrospun materials should be designed and fabricated. In this study, silk fibroin smooth fiber materials, bead-on-string fiber materials and coaxial bead-on-string fiber materials were fabricated and their drug release behaviors were compared in different pH. The drug release experiments showed that the electrospun materials showed pH-sensitive releasing behaviors. They released faster and more amount of drugs in acid buffer. Besides, the electrospun coaxial bead-on-string fiber material has a slower release rate compared with the smooth fiber and bead-on-string fiber materials. The coaxial bead-on-string fiber material is an efficient and of potential for being used as sustained drug delivery system to treat cancers.

Background/aims Sheep are important livestock with variant ovulation rate and fertility. Dorset sheep is a typical breed with low prolificacy, whereas Small Tail Han sheep with FecB mutation (HanBB) have hyperprolificacy. Our previous studies have revealed the gene expression difference between the ovaries from Dorset and HanBB sheep contributes to the difference of fecundity, however, what leads to these gene expression difference remains unclear. DNA methylation, an important epigenetic process, plays a crucial role in gene expression regulation. Methods In the present study, we constructed a methylated DNA immunoprecipitation combined with high throughput sequencing (MeDIP-seq) strategy to investigate the differentially methylated genes between the Dorset and HanBB ovaries. Results Our findings suggest the genes involved in immune response, branched-chain amino acid metabolism, cell growth and cell junction were differentially methylated in or around the gene body regions. Conclusions These findings provide prospective insights on the epigenetic basis of sheep fecundity.

To get an insight into the occurrence and the mechanism of flow unsteadiness in the tip region of centrifugal compressor impellers, the flow in Krain’s impeller is investigated by using both steady and unsteady RANS solver techniques. It is found that the flow unsteadiness on the pressure side is much stronger than that on the suction side. The periodical frequency of the unsteady flow is around half of the blade passing frequency. The originating mechanism of the flow unsteadiness is illustrated with the time-dependent tip leakage flow and blade loading at the tip region. Due to the blockage caused by the joint effects of broken-downed tip leakage vortex, separated fluids and tip leakage flow at downstream, a low pressure region is formed on the pressure side, consequently the blade loadings is altered. In turn, the changed blade loadings will alter the intensity of tip leakage flow. Such alternative behavior finally results in the periodic process. By comparing the calculated flow field in the cases of single-passage and four-passage models, it is confirmed that the investigated flow unsteadiness is confined in each single passage, as no phase differences are found in the model of four passages. This is different from the situation in axial compressor when the rotating instability is encountered. The flow unsteadiness only occurs at the working conditions with small mass flow rates, and the oscillation intensity will be enhanced with the decrease of mass flow rate. When the mass flow rate is too small, the flow unsteadiness in a single passage may trigger rotating stall, as the disturbance propagates in the circumferential direction.

A series of Zr/Al/Mg composite oxide catalysts were prepared by the co-precipitation method. The catalytic performances of Zr/Al/Mg composite oxide catalysts in the synthesis of ethylene glycol ethyl ether acetate by the ethoxylation of ethyl acetate with ethylene oxide were investigated. The results indicated that the addition of zirconium to Al/Mg composite oxides led to the increase in the amount of basic sites and the decrease in the amount of acid sites simultaneously. The excellent catalytic performance of Zr/Al/Mg composite oxide catalysts for the ethoxylation of ethyl acetate could be attributed to the co-operativity of the acidic and basic sites on the catalysts.

The interfacial reaction in Cu/Sn/Cu solder joint during liquid–solid eletromigration (EM) was in situ studied using synchrotron radiation real-time imaging technology. The current density distribution in the solder joint was analyzed with the finite element method (FEM). The relationships among solder shape, current density distribution, Cu dissolution, and the formation and dissolution of interfacial intermetallic compound (IMC) were revealed. The current promoted dissolution of the cathode IMC and growth of the anode IMC and suppressed the dissolution of anode Cu. The change of interfacial IMC had little effect on the current density distribution; however, the dissolution of cathode Cu, which changed the solder shape, had a significant effect on the current density distribution. The dissolution of cathode Cu under forward current and cathode IMC under reverse current and the growth of anode IMC under forward current was faster where the current density was higher. The synchrotron radiation real-time imaging technology can not only in situ observe the change of solder shape, the dissolution and growth behavior of interfacial IMC and the dissolution behavior of substrate in a soldering process but also provide data needed for numerical simulation of current density distribution in a solder joint.

This paper reports silicon and oxygen isotopes of 20 kinds of igneous rocks and their major elements from the eastern Manus Basin. Combining silicon and oxygen isotopic data from other studies, we suppose that both delta Si-30 and delta O-18 values increase with the increasing of SiO2 content. It means that the fractionation of silicon and oxygen isotopes are affected by the silica content. The positive correlation between CaO/Al2O3 ratios and MgO and that between Si/Al and SiO2 content indicate that clinopyroxene is the predominant mineral phase in our samples. We suppose that the fractionation of silicon and oxygen isotopes are influenced by mineral fractional crystallization. Probably, it is due to their different silicon and oxygen bridges. In this study, the delta S-30(imean value) = -0.17aEuro degrees +/- 0.17aEuro degrees and delta O-18(mean value) = +6.07aEuro degrees +/- 0.57aEuro degrees are higher than normal delta Si-30 and delta O-18 values of mantle, and we propose that these igneous rocks in the eastern Manus Basin are affected by hydrothermal alteration.

Goat fecundity is important for agriculture and varies depending on the genetic background of the goat. Two excellent domestic breeds in China, the Jining Grey and Laiwu Black goats, have different fecundity and prolificacies. To explore the potential miRNAs that regulate the expression of the genes involved in these prolific differences and to potentially discover new miRNAs, we performed a genome-wide analysis of the miRNAs in the ovaries from these two goats using RNA-Seq technology. Thirty miRNAs were differentially expressed between the Jining Grey and Laiwu Black goats. Gene Ontology and KEGG pathway analyses revealed that the target genes of the differentially expressed miRNAs were significantly enriched in several biological processes and pathways. A protein-protein interaction analysis indicated that the miRNAs and their target genes were related to the reproduction complex regulation network. The differential miRNA expression profiles found in the ovaries between the two distinctive breeds of goats studied here provide a unique resource for addressing fecundity differences in goats.

In this study, 13 groups of silicon and oxygen isotopes and major elements of the basalts near the East Pacific Rise 13 degrees N are used to study the fractionation of silicon and oxygen isotopes. Among these data, delta Si-30 values of basalts vary from -0.4 parts per thousand to 0.2 parts per thousand with a mean value of delta Si-30 of (-0.18 +/- 0.22)parts per thousand. The delta O-18 values range from 4.1 parts per thousand to 6.4 parts per thousand with a mean delta O-18 value of (+5.35 +/- 0.73)parts per thousand. Since the delta Si-30 values increase in the series of basalt-basaltic andesite- andesite, and delta O-18 values display a positive correlation with the SiO2 content, we propose that the fractionation of silicon and oxygen isotopes is influenced by the SiO2 content in igneous rocks. Compared with the igneous rocks from Manus Basin with clinopyroxene as their dominant mineral phase, MORBs in this study containing olivine and plagioclase as primary minerals have lower delta O-18 and delta Si-30 values, indicating that the fractionation of silicon and oxygen isotopes is also affected by different Si-O bridges in silicate minerals. Furthermore, our samples from the EPR are defined as E-MORB based on K/Ti ratios. Probably, the difference in delta Si-30 and delta O-18 between our samples and a normal MORB are cause by the enriched components in E-MORBs.

In 2008–2009, hydrothermal barnacle and sediment samples were collected from the Southwest Indian Ridge during a survey of the China Ocean Mineral Resources R&D Association (COMRA). Samples were analyzed by gas chromatography-mass spectrometer (GC-MS), revealing the main organic constituents of hydrothermal barnacle and sediment to be fatty acids and alkylbenzenes. N-alkanes which possessed obvious even carbon advantage were also detected in hydrothermal sediment. The high concentrations of aromatic compounds might be the result of macromolecular thermal alteration. Microorganism in the submarine hydrothermal ecosystem, especially those related to sulfur metabolism, might be the source of the high concentrations of fatty acids detected in these samples. In high temperature and high pressure hydrothermal environments, n-alkanes which possessed obvious even carbon advantage might originate from thermal alteration of carboxylic acids and other lipid compounds.

The fatigue resistance of twelve tubular textile samples designed for use in prototype endovascular devices was tested by an accelerated fatigue tester. Three time points were selected, namely 0, 26×106, and 100×106 cycles, which are equivalent to 0, 10 months, and 38.5 months implanted in the human body. Changes in tubular diameter, woven fabric count, thickness, mass per unit area, porosity, water permeability, and bursting strength were selected to characterize the performance of these samples before and after fatigue testing. The results showed that all the samples experienced some fatigue during the study, and the evidence of fatigue became more apparent with increasing time. There were clearly observable relationships between the textile parameters and the fatigue performance of the prototype samples. Woven construction, yarn size and yarn type all interacted with each other to influence the fatigue performance. Samples with twill weaves fatigued more readily than those with a 1/1 plain weave. For all three woven constructions, samples with larger yarn size fatigued more easily. However, the fatigue performance of some samples with multifilament weft yarns is severe.

Automatic extraction of roads from digital images has been an active research subject for over a decade because its significant role in many application area, like Intelligent Transportation Systems (ITS) and transportation navigation as well as GIS applications. Especially, road network is one of most important features in GIS layer. Traditionally, surveying and photogrammetry are the only ways to map details in urban areas even though it is well known that they are resource and time consuming. Recently, high-resolution satellite image has become widely available, and moreover, several high-resolution satellite images have become commercially available for civilian applications, due to the development of remote sensors and satellite technologies. This shows an opportunity for so-called urban remote sensing to challenge the topic of urban details mapping. The focus of this paper is on developing an approach for extracting urban and suburban road network from high-resolution satellite image. “Road mask” is defined in this research as a mask of road pixels, which are discriminated from others using commercial remote sensing software. “Road seed” is defined in this research as a directional point, indicating that a road is passing through the point along the direction. Road seeds are extracted from edge pixels. Road line extraction is conducted in a semi-automatic way by fusing both road mask and road seeds. Experiments are conducted using an IKONOS image with a ground resolution of 1 meter, and four bands, i.e. red, green, blue, and near infrared. Experimental results show that the method is valid in extracting main roads in high dense building area and most of the roads in countryside efficiently. Besides the general description of the approach, this paper describes the newly proposed line segment match method in detail.

In this paper, a novel method is presented for generating a textured CAD model of an outdoor urban environment using a vehicle-borne sensor system. In data measurement, three single-row laser range scanners and six line cameras are mounted on a measurement vehicle, which has been equipped with a GPS/INS/Odometer-based navigation system. Laser range and line images are measured as the vehicle moves forward. They are synchronized with the navigation system so they can be geo-referenced to a world coordinate system. Generation of the CAD model is conducted in two steps. A geometric model is first generated using the geo-referenced laser range data, where urban features, such as buildings, ground surfaces, and trees are extracted in a hierarchical way. Different urban features are represented using different geometric primitives, such as a planar face, a triangulated irregular network (TIN), and a triangle. The texture of the urban features is generated by projecting and resampling line images onto the geometric model. An outdoor experiment is conducted, and a textured CAD model of a real urban environment is reconstructed in a full automatic mode.