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Pig domestication and management strategy has been increasingly discussed in recent years, focusing on the temporal-spatial differences of pig management strategies. The East Liao River Basin with diverse ecosystems, cultural exchanges, and collisions plays an important role in the cultural development, exchange, and integration processes between Northeast China and the Central Plains. Multiple studies have revealed that various forms of subsistence economy, such as nomadism, fishing and hunting, and farming, existed in this region. However, no report or discussion has been presented concerning the status of domestic animal management strategies over a long-term in the East Liao River Basin. Carbon and nitrogen stable isotopes analysis were performed on the fauna bones at the Changshan site in Siping, Jilin, China, from the Bronze Age (c. 2000–256 BC) to the Liaojin Dynasties (907–1234 AD), to reconstruct their dietary pattern and reveal the status of domestic animal management strategies, especially the diachronic changes in pig feeding strategies. The results showed that pigs (–19.3 ± 1.6%, 5.3 ± 0.9%, n = 27), horses (–18.4 ± 1.7%, 4.8 ± 1.4%, n = 7), and sheep (–19.8 ± 1.5%, 5.7 ± 0.5%, n = 6) primarily received their subsistence through C3-based food. Nevertheless, cattle (–16.4 ± 3.5%, 6.0 ± 2.1%, n = 2) and the past human (–13.9%, 10.3%, n = 1) lived on mixed C3/C4-based food. Notably, the stable isotope data for pigs from the Bronze Age (–19.1 ± 2.0%, 5.4 ± 1.0%, n = 9) to the Liaojin Dynasties (–19.8 ± 0.6%, 5.1 ± 0.7%, n = 15) were similar, indicating that the management and/or feeding strategy of domestic pigs were relatively stable with a free range in a wild ecosystem over a long period. Related studies have shown that pigs in captivity were mainly fed by millet-based food in the West Liao River Basin and the middle reaches of the Yellow River valley, where millet agriculture were adequately developed. Abundant natural resources, including plants, wild animals, and fishes, could provide sufficient food to the past population in the East Liao River Basin. Thus, the millet-based agriculture was just an auxiliary subsistence strategy in the Changshan site, leading to a gap in the driving force for long-term intensive management of pig.

We have investigated the linear and third-order nonlinear optical properties in a charge-transfer (CT) type conjugated copolymer, PThQx, which is composed of an electron-donating molecule, thiophene (Th), and electron-accepting one, quinoxaline (Qx), by using the linear absorption, two-photon absorption (TPA), and third-harmonic generation (THG) spectroscopies. In comparison with a homopolymer, polythiophene, the absorption coefficient α of PThQx is significantly reduced, while its third-order nonlinear susceptibility (χ (3) ) is unchanged. This indicates that the figure of merit for the nonlinear optical materials, defined as χ (3) /α, is enhanced in PThQx. This enhancement comes from the CT character of the excited states in PThQx, in which a hole and an electron are created on different molecules.

Anatase TiO2 nanoparticles with average particle size ranging between 12 and 23 nm were synthesized by metalorganic chemical vapor deposition. The structure and particle size were determined by x-ray diffraction and transmission electron microscopy. The specific surface areas were measured by Brunauer-Emmett-Teller and ranged from 65 to 125m2∕g. The size effects on the stability of TiO2 in the air were studied by x-ray diffraction and transmission electron diffraction for isochronally annealed samples in the temperature range of 700–800 °C. Only anatase to rutile phase transformation occurred. With the decrease of initial particle size the onset transition temperature was decreased. An increased lattice compression of anatase with the raising of temperature was observed by the x-ray peak shifts. Larger distortions existed in samples with smaller particle size. The calculated activation energy for phase transformation decreased from 299 to 180 kJ∕mol with the decrease of initial anatase particle size from ...

A new π-conjugated charge-transfer-type copolymer of electron-donating thiophene and electron-accepting quinoxaline was prepared by organometallic polycondensation. The polymer was soluble in organic solvents such as tetrahydrofuran, and showed a UV-vis peak at long wavelengths of 598 nm in chloroform and 629 nm in the film. Its film exhibited a χ (3) peak in the resonance region with a χ (3) value comparable to that of regioregular head-to-tail poly(3-hexylthiophene-2,3-diyl).

PURPOSE To report an in-progress experiment in a canine model in which two types of small-diameter stent-grafts— one constructed of polytetrafluoroethylene (PTFE) and the other of a new, type 1 collagen material—were compared regarding vessel patency, intimal hyperplasia formation, and tissue reaction. MATERIALS AND METHODS Six mongrel dogs weighing 30–35 kg were used. Stent-grafts of 4-mm diameter and 20-mm length were constructed with use of balloon-expandable stainless-steel stents wrapped with either PTFE or a new type 1 collagen graft. Stent-grafts were placed in deep femoral arteries bilaterally (PTFE on one side, collagen on the other). Animals were followed for 2 weeks ( n = 2), 6 weeks ( n = 2), or 12 weeks ( n = 2). Percent stenosis based on angiographic findings as well as thickness and area of neointimal hyperplasia were compared at each time point and compared with use of the Student t test. RESULTS All devices were patent in the immediate postimplantation period. Five of six collagen stent-grafts and five of six PTFE implants were patent at follow-up. In-stent stenosis was undetectable angiographically in all five patent collagen stent-grafts. All five patent PTFE stent-grafts showed demonstrable in-stent stenosis (10%–60%), indicating a trend toward improved patency in collagen stent-grafts versus PTFE stent-grafts ( P = .07). Neointimal hyperplasia was absent at 2 weeks in the collagen stent-grafts. Neointimal thickness increased to a maximum of 360 μm at 12 weeks in the collagen stent-grafts. For PTFE stent-grafts, neointimal hyperplasia was present in all samples and reached a maximum of 770 μm at 12 weeks ( P = .03). CONCLUSIONS Even in small-diameter vessels, type 1 collagen stent-grafts demonstrate excellent patency rates and favorable histologic findings. The type 1 collagen stent-graft technology merits further developmental efforts in preclinical models.

KOR-3, also known as ORL-1, is a member of the opioid receptor family, encoding the murine receptor for orphanin FQ/nociceptin. In the current studies we have identified five different splice variants of KOR-3 in mouse brain, three of which have not been previously reported. In addition to variants with a 15 bp deletion at the 3′-end of the first coding exon (KOR-3d) and an 81 bp insertion between the second and third coding exons (KOR-3e), three new variants with insertions of 34 (KOR-3a), 98 (KOR-3b), and 139 bp (KOR-3c) between the first and second coding exons have been obtained. The expression of the three variants in mouse brain varies markedly among brain regions with a distribution which is quite distinct from KOR-3 itself. Of greatest interest was the presence of high levels of KOR-3a in the striatum, a region with no demonstrable KOR-3, and in the cortex. KOR-3c was seen in the periaqueductal gray and hypothalamus, regions where KOR-3 predominated. The brainstem had similar levels of KOR-3, KOR-3a, and KOR-3d. In contrast, KOR-3d was most prominent in the cerebellum. KOR-3b levels were very low throughout.

Self-assembled monolayers of alkylsiloxanes supported on polydimethyl siloxane (PDMS) rubber were used as model systems to study the relation between blood compatibility and surface chemistry. The inner lumen of PDMS tubes was first treated with an oxygen plasma. The resultant oxidized surfaces were postderivatized by reacting them with alkyltrichlorosilanes to form the monolayer films. The chemical properties of the monolayers were controlled by varying the head-group chemical compositions. Surface derivatization was verified using variable-angle X-ray photoelectron spectroscopy (XPS or ESCA). Blood compatibility was evaluated using a canine ex vivo arteriovenous series shunt model. Surfaces grafted with hydrophobic head-groups as -CH3 and -CF3 had significantly lower platelet and fibrinogen deposition than the surfaces composed of hydrophilic groups such as -CO2CH3, -(CH2CH2O)3COCH3, and -(OCH2CH2)3OH. © 1995 John Wiley & Sons, Inc.

The acute blood-contacting properties of five silicone-containing elastomers and a poly(vinyl alcohol) coated silicone elastomer were assessed using a canine ex vivo shunt model. The silicone-containing elastomers studied included two thermoset amorphous silica reinforced dimethyl methylvinyl siloxane-based polymers which were extruded as Silastic® RX-50 Medical Grade Tubing (RX-50) and Silastic® Medical Grade Tubing H.P. (HP). They also included three experimental thermoplastic silicone-urea urethane copolymers received as X7-4074 (SP-1), X7-4037 (SP-2), and X7-4943 (SP-3). The RX-50 tubing material showed less thrombus deposition compared to the silicone-urea urethane copolymers. This suggests that the blood-contacting response of a silicone elastomer is strongly affected by the incorporation of the urea urethane segments. Among the silicone-urea urethane copolymers, the SP-3 material showed higher levels of platelet and fibrinogen deposition than the SP-1 and SP-2 materials, whereas the SP-1 and SP-2 samples had similar levels of deposition. These results indicate that the blood-contacting properties of the silicone-urea urethane copolymers were influenced more by the molecular weight of the polydimethylsiloxane than by the type of diol used in the urea urethane segments. The maximal platelet deposition on the poly vinyl alcohol-coated silicone was approximately an order of magnitude greater than those on the silicone-containing elastomers indicating that the PVA coating was more thrombogenic.

In an attempt to improve endothelial cell adhesion and growth on a polyurethane copolymer, cell adhesive RGD-containing peptides were grafted to the polymer backbone. Two peptide grafting reaction schemes, including one-step and two-step approaches, were developed. Amino acid analysis confirmed that the two-step approach had a higher peptide coupling efficiency. The two-step reaction scheme was utilized to prepare GRGDSY, GRGDVY and GRGESY (inactive control) peptide grafted polyurethanes with two different peptide densities (100 and 250 μmol/g polymer). In-vitro endothelial cell adhesion experiments showed that, without the presence of serum in culture medium, the GRGDSY- and GRGDVY-grafted polyurethanes dramatically enhanced cell attachment and spreading. Increasing the peptide density from 100 to 250 jimol/g polymer for the GRGDSY-and GRGDVY-grafted polyurethanes resulted in an increase in cell attachment. Similar trends were observed in endothelial cell growth studies using culture medium containing serum and growth supplement.

Peptides based on cell-adhesive regions of fibronectin, Arg-Gly-Asp-Ser (RGDS), and vitronectin, Arg-Gly-Asp-Val (RGDV), were covalently bound to a polyurethane backbone via amide bonds. Nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectroscopies were used to monitor the reactions. The amount of grafted peptide was determined by amino acid analysis. X-ray photoelectron spectroscopy (XPS) suggested the presence of the grafted peptide at the polymer-air interface in vacuo. Dynamic contact angle analysis showed that, in water, the peptide-grafted polyurethane surfaces were more polar than the underivatized polyurethane indicating enrichment of peptide groups at the surface. The attachment and spreading of human umbilical vein endothelial cells (HUVECs) on the underivatized and peptide-grafted polyurethanes was investigated. The GRGDSY- and GRGDVY-grafted substrates supported cell adhesion and spreading even without serum in the culture medium. The GRGDVY-grafted substrate supported a larger number of adherent cells and a higher extent of cell spreading than the GRGDSY-grafted substrate. These RGD-containing peptide-grafted polyurethane copolymers may be useful in providing an easily prepared celladhesive substrate for various biomaterial applications.

PURPOSE To compare patency rates and degrees of neointimal hyperplasia between bovine type 1 collagen stent-grafts and uncovered control stents in small-diameter vessels ( MATERIALS AND METHODS Uncovered stainless-steel, balloon-expandable stents ( n = 5) and type 1 collagen stent-grafts ( n = 6) were implanted via the femoral arteries with use of 4-mm balloon catheters into the abdominal aorta of New Zealand White rabbits. Ten animals were available for follow-up. Subjects were followed for 1 month (three uncovered stents; three collagen stent-grafts) or 4 months (two uncovered stents; two collagen stent-grafts). Angiography was performed before animal sacrifice and luminal compromise was compared between groups. Histologic and immunohistochemical analysis was performed to determine presence of neointima and neointimal thickness and area; these parameters were also compared between groups. RESULTS All stents and stent-grafts remained patent at both time points. Luminal compromise was not detectable angiographically in any subject. Maximum neointimal thickness was less than 5 μm for all subjects. Neointimal thickness and area were not statistically significantly different between groups. CONCLUSIONS Type 1 collagen stent-grafts demonstrate excellent hemocompatibility and biocompatibility in small-diameter vessels in rabbits.

WC nanoparticles where synthesized using various Physical Vapor Deposition (PVD) methods such as reactive sputtering and Pulsed Laser Deposition (PLD). In both the methods the metal flux obtained is condensed in the presence of He gas. The structural properties of the samples where investigated using X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). The feasibility of using nano-WC as an alternative catalyst for Pt is determined. A comparative study on two sample of WC, as-prepared and carburized W, was done. The samples were used to check for the reduction of NOx in a simple reactor. The carburized W shows activity at temperatures around 400°C whereas the as-prepared WC shows activity towards NOx reduction at a slightly higher temperature. The stability of both the sample was studied by performing the same experiment at a fixed temperature for an extended period of time. XPS and XRD confirm the formation of oxide phase after de-NOx experiments.

Purpose To evaluate in a swine model the hemostatic properties of a new, expansile type I collagen plug for use in high-risk renal biopsies. Materials and Methods Highly purified bovine type I collagen was formed into porous cylindrical plugs and compressed radially to fit into a 5-F delivery system. On hydration these collagen plugs demonstrated radial expansion with approximately 1,600% volumetric expansion ratio. Direct exposure of both kidneys was performed in a 25-kg swine, and a bolus of 3,000 U of heparin was administered to create a coagulopathic state. A 14-gauge Temno coaxial biopsy gun was utilized in performing nine pairs of renal biopsies. The first biopsy of each biopsy pair represented the control biopsy (without collagen plug placement), whereas the second biopsy of each pair represented the plugged biopsy. The presence and duration of hemorrhage from each biopsy site was monitored visually. Results The biopsy sites without collagen plug showed immediate hemorrhage in nine of nine cases (100%), and in two of nine cases (22%) pulsatile bleeding was noted. With the use of the collagen plug, seven of nine (78%) sites showed immediate hemorrhage, but in no case was pulsatile bleeding noted. Mean bleeding duration was 156 seconds for the control biopsies versus 73 seconds for the biopsy sites plugged with collagen ( P = .03, Mann-Whitney rank sum test). Bleeding duration was less than 1 minute in only one of nine (11%) control biopsies compared to six of nine (67%) collagen plug biopsies. Conclusions A recently developed, expansile collagen hemostatic plug significantly decreases the duration of hemorrhage at renal biopsy sites in an anticoagulated swine model.

A cDNA clone (S2-1a) isolated from a mouse brain cDNA library, using a guinea pig sigma1 cDNA as probe, has high homology to the predicted protein sequence of the guinea pig (88%) and human (90%) sigma1 receptors. Northern analysis revealed a major mRNA of approximately 1.8 kb in a wide range of mouse tissues, with highest levels in brain, liver, kidney, and thymus. Southern analysis and chromosomal mapping in the mouse suggested a single-copy gene in region A5-B2 of chromosome 4. Expression of the clone in MCF-7 and CHO cells led to a pronounced increase in (+)-[3H]pentazocine binding with a selectivity profile consistent with sigma1 receptors. In vitro translation yielded a protein of approximately 28 kDa, as did transfection of a probe containing the hemagglutinin (HA) epitope (S2-1a.HA) into CHO cells, as determined by western analysis using an antibody directed against HA. (+)-[3H]-Pentazocine binding to immunopurified HA-tagged receptor demonstrated conclusively that S2-1a.HA encodes a high-affinity (+)-[3H]pentazocine binding site with characteristics of a murine sigma1 receptor. An antisense oligodeoxynucleotide designed from S2-1a potentiated opioid analgesia in vivo.

Polyurethanes which are grafted with propyl sulphonate functionality have excellent blood-contacting properties. In a canine ex vivo series shunt experiment, very low platelet deposition was observed on these materials and those platelets which were adherent remained unspread. In contrast to this, large amounts of fibrinogen, of the order of a monolayer or greater, were deposited on these surfaces in this ex vivo experiment. This led to the hypothesis that perhaps the deposited fibrinogen did not retain its platelet-adhesive activity. In this paper, we investigate the possibility that these materials exert their antithrombotic effects through the adsorbed protein layer. Protein adsorption kinetics and isotherms on these sulphonated polyurethanes are determined. Multilayer protein adsorption or absorption into the hydrogel-like materials is found for each of the proteins studied, and the greatest amounts of protein are seen on the most highly sulphonated polyurethanes. Further, the blood-contacting response of these materials is investigated after pre-conditioning with either fibrinogen, fibronectin or albumin. When these materials are pre-adsorbed with either fibrinogen or fibronectin, a very thrombogenic response was observed, which suggests that the platelet-adhesive activity of these proteins is not being reduced. Pre-adsorption of albumin did not improve the thromboresistance of these surfaces.

Variable take-off angle and cold-stage ESCA measurements were utilized to analyze the surface composition of five polyurethane block copolymers. The polymers studied included a PTMO-polyurethane control, a carboxylated version of the control polyurethane, and three different peptide grafted (GRGESY, GRGDSY, and GRGDVY) polyurethanes. On dry samples the nitrogen signal detected using ESCA decreased with increasing take-off angle (i.e. as the specimen was probed closer to the surface) for all five polymers. This was believed to be due to the depletion of nitrogen-containing urethane hard segments at the surface. For all five polymers, the surface nitrogen concentration, associated with the hard segment, increased upon hydration. A greater increase of nitrogen concentration was observed for the peptide grafted polymers which suggests that grafting of the hydrophilic peptides to the polyurethane augments the hard segment enrichment at the surface upon hydration. Upon dehydration, the nitrogen concentration decreased for all five polymers suggesting migration of the more hydrophobic PTMO soft segment to the surface. In vitro endothelial cell adhesion showed an increase of cell attachment on prehydrated RGD-containing peptide grafted polyurethanes, but not on the other polymers. This result suggests an enhancement of peptide density at the aqueous interface, in good agreement with the ESCA studies.

In an attempt to improve endothelial cell adhesion and growth on a polyurethane copolymer, cell adhesive RGD-containing peptides were grafted to the polymer backbone. Two peptide grafting reaction schemes, including one-step and two-step approaches, were developed. Amino acid analysis confirmed that the two-step approach had a higher peptide coupling efficiency. The two-step reaction scheme was utilized to prepare GRGDSY, GRGDVY and GRGESY (inactive control) peptide grafted polyurethanes with two different peptide densities (100 and 250 μmol/g polymer). Dynamic contact angle measurements indicated that the surfaces of the peptide grafted polyurethanes were more hydrophilic than the starting and carboxylated versions of the precursor polyurethane. In-vitro endothelial cell adhesion experiments showed that, without the presence of serum in culture medium, the GRGDSY- and GRGDVY-grafted polyurethanes dramatically enhanced cell attachment and spreading. Increasing the peptide density from 100 to 250 μmol/g polymer for the GRGDSYand GRGDVY-grafted polyurethanes resulted in an increase in cell attachment. With approximately the same peptide density (100 or 250 μmol/g polymer), the GRGDVY-grafted polymers supported more adherent cells than the GRGDSY-grafted polymers. Similar trends were observed in the in-vitro endothelial cell growth studies using culture medium containing serum and endothelial cell growth supplement. These RGD-peptide grafted polyurethanes may be useful in providing an easily prepared cell-adhesive substrate for various implantable devices and hybrid organs.

Hydrogen is among several energy sources that will be needed to replace the quickly diminishing fossil fuels. Free hydrogen is not available naturally on earth and the current processes require a fossil fuel, methane, to generate hydrogen. Electrochemical splitting of water on titania proposed by Fujishima suffers from low efficiency. The efficiency could be enhanced if full sun spectrum can be utilized. Using pulsed laser deposition technique we synthesized nitrogen doped titanium dioxide (TiO2−xNx) thin films with improved visible light sensitivity. The photoactivity was found to be N concentration dependent. Hydrogen evolution was observed under visible light irradiation (wavelength>390 nm) without the presence of any organic electron donor.

The synthesis of a novel polyurethane block co-polymer containing a covalently attached, well-oriented RGD (Arg-Gly-Asp) peptide was explored. A poly(tetramethylene oxide) (PTMO)-based polyurethane was synthesized, and a bimolecular nucleophilic substitution reaction was then employed to incorporate ethyl carboxylate groups onto the polymer backbone (i.e. carboxylated polyurethane). Elemental analysis was used to determine the extent of carboxylation. The hexapeptide H-Gly-Arg-Gly-Asp-Ser-Tyr-OH was coupled to the carboxylated polyurethane via the formation of an amide bond. The attachment of the peptide was controlled by a protection-deprotection scheme. Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopies were used to monitor the reactions. Sakaguchi assay and amino acid analysis confirmed that the RGD-containing peptide was successfully grafted onto the carboxylated polyurethane. This reaction scheme provides a new route for grafting end-linked, bioactive peptides onto polyurethanes.

We have determined the electronic and atomic structure of N doped TiO2 using a combination of hard x-ray photoelectron spectroscopy and first-principles density functional theory calculations. Our results reveal that N doping of TiO2 leads to the formation of oxygen vacancies and the combination of both N impurity and oxygen vacancies accounts for the observed visible light catalytic behavior of N doped TiO2.

Synthesis of novel polyurethane copolymers containing covalently attached, well-oriented Arg-Gly-Asp (RGD) peptides was explored. A poly(tetramethylene oxide) based polyurethane was synthesized, and a bimolecular nucleophilic substitution reaction was then employed to incorporate ethyl carboxylate groups onto the polymer backbone. Cell-adhesive peptides Gly-Arg-Gly-Asp-Ser-Tyr (GRGDSY) and Gly-Arg-Gly-Asp-Val-Tyr (GRGDVY) were covalently bound to the polyurethane backbone via the formation of amide bonds. Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopies were used to monitor the reactions. The amount of grafted peptide was determined by amino acid analysis. Electron spectroscopy for Chemical Analysis (ESCA) suggested the presence of the grafted peptide at the polymer-air interface in vacuo. Dynamic contact angle analysis showed that, in water, the peptide-grafted polyurethane surfaces were more polar than the underivatized polyurethane. The attachment and spreading of human umbilical vein endothelial cells (HUVECs) on the underivatized and peptide-grafted polyurethanes was investigated. The GRGDSY-and GRGDVY-grafted substrates supported cell adhesion and spreading even without serum in culture medium. The GRGDVYgrafted substrate supported a larger number of adherent cells and a higher extent of cell spreading than the GRGDSY-grafted substrate. These RGD-containing peptide grafted polyurethane copolymers may be useful in providing an easily prepared cell-adhesive substrate for various biomaterial applications.

WC nanoparticles were synthesized using a variation of pulsed laser deposition (PLD) process. In this modified PLD the ablated plume is carried away by a circulating carrier gas from the evaporation region. It is then allowed to condense heterogeneously and the condensed particles are collected on a filter. Using this technique we synthesized two different types of particles, as-prepared WC and pure W nanoparticles. Pure W nanoparticles were subsequently carburized to form WC. These nanoparticles were used to study the feasibility for the use in NOx reduction. The structural and chemical properties of these samples were analyzed using x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). Catalytic activity was measured using a tube reactor. A combination of 1% NO and 99% He gas was used. Both the pure WC and carburized WC samples were found to be catalytically active with an activation temperature of about 400°C. The stability of the catalysts was studied by performing de-NOx experiments for...

Nitrogen-doped TiO2 nanoparticles were synthesized via plasma assisted metal organic chemical vapor deposition. Nitrogen dopant concentration was varied from 0to1.61at.%. The effect of nitrogen ion doping on visible light photocatalysis has been investigated. Samples were analyzed by various analytical techniques such as x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy, and near-edge x-ray absorption fine structure. Titanium tetraisopropoxide was used as the titanium precursor, while rf-plasma-decomposed ammonia was used as the source for nitrogen doping. The N-doped TiO2 nanoparticles were deposited on stainless steel mesh under a flow of Ar and O2 gases at 600°C in a tube reactor. The photocatalytic activity of the prepared N-doped TiO2 samples was tested by the degradation of 2-chlorophenol (2-CP) in an aqueous solution using a visible lamp equipped with an UV filter. The efficiency of photocatalytic oxidation of 2-CP was measured using high performance liquid chrom...