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There is an increasing appreciation that many innate and adaptive immune cell subsets permanently reside within non-lymphoid organs, playing a critical role in tissue homeostasis and defense. The best characterized are macrophages and tissue-resident T lymphocytes that work in concert with organ structural cells to generate appropriate immune responses and are functionally shaped by organ-specific environmental cues. The interaction of tissue epithelial, endothelial and stromal cells is also required to attract, differentiate, polarize and maintain organ immune cells in their tissue niche. All of these processes require dynamic regulation of cellular transcriptional programmes, with epigenetic mechanisms playing a critical role, including DNA methylation and post-translational histone modifications. A failure to appropriately regulate immune cell transcription inevitably results in inadequate or inappropriate immune responses and organ pathology. Here, with a focus on the mammalian kidney, an organ which generates differing regional environmental cues (including hypersalinity and hypoxia) due to its physiological functions, we will review the basic concepts of tissue immunity, discuss the technologies available to profile epigenetic modifications in tissue immune cells, including those that enable single-cell profiling, and consider how these mechanisms influence the development, phenotype, activation and function of different tissue immune cell subsets, as well as the immunological function of structural cells.

The Fisher-Kolmogorov-Petrovsky-Piskunov (FKPP) equation provides a mean-field theory of out-of-time-ordered commutators in locally interacting quantum chaotic systems at high energy density; in the systems with power-law interactions, the corresponding fractional-derivative FKPP equation provides an analogous mean-field theory. However, the fractional FKPP description is potentially subject to strong quantum fluctuation effects, so it is not clear a priori if it provides a suitable effective description for generic chaotic systems with power-law interactions. Here we study this problem using a model of coupled quantum dots with interactions decaying as $\frac{1}{r^{\alpha}}$, where each dot hosts $N$ degrees of freedom. The large $N$ limit corresponds to the mean-field description, while quantum fluctuations contributing to the OTOC can be modeled by $\frac{1}{N}$ corrections consisting of a cutoff function and noise. Within this framework, we show that the parameters of the effective theory can be chosen to reproduce the butterfly light cone scalings that we previously found for $N=1$ and generic finite $N$. In order to reproduce these scalings, the fractional index $\mu$ in the FKPP equation needs to be shifted from the na\"ive value of $\mu = 2\alpha - 1$ to a renormalized value $\mu = 2\alpha - 2$. We provide supporting analytic evidence for the cutoff model and numerical confirmation for the full fractional FKPP equation with cutoff and noise., Comment: 17+1 pages, 14 figures

We used online customer reviews of smartphones from eight countries to explore the gender effects on the evaluation of electronic word of mouths (eWOMs). We found that male eWOMs valence had a more significant impact on the market shares of smartphones than female and anonymous eWOM valence, but the impact of female eWOM valence increased with the level of gender equality. To minimize gender stereotypes in eWOM evaluation, we recommend online review platforms remove the option of anonymity and replace it with gender-neutral user IDs.

Bladder exstrophy-epispadias complex (BEEC) comprises a spectrum of anterior midline congenital malformations, involving the lower urinary tract. BEEC is usually sporadic, but families with more than one affected member have been reported, and a twin concordance study supported a genetic contribution to pathogenesis. Moreover, diverse chromosomal aberrations have been reported in a small subset of individuals with BEEC. The commonest are 22q11.2 microduplications, identified in approximately 3% of BEEC index cases.We aimed to refine the chromosome 22q11.2 locus, and to determine whether the encompassed genes are expressed in normal developing and mature human urinary bladders.Using DNA from an individual with CBE, the 22q11.2 duplicated locus was refined by identification of a maternally inherited 314 kb duplication (chr22:21,147,293-21,461,017), as depicted in this image. Moreover, the eight protein coding genes within the locus were found to be expressed during normal developing and mature bladders. To determine whether duplications in any of these individual genes were associated with CBE, we undertook copy number analyses in 115 individuals with CBE without duplications of the whole locus. No duplications of individual genes were found.The current study has refined the 22q11.2 locus associated with BEEC and has shown that the eight protein coding genes are expressed in human bladders both during antenatal development and postnatally. Nevertheless, the precise biological explanation as to why duplication of the phenocritical region of 22q11 confers increased susceptibility to BEEC remains to be determined. The fact that individuals with CBE without duplications of the whole locus also lacked duplication of any of the individual genes suggests that in individuals with BEEC and duplication of the 22q11.2 locus altered dosage of more than one gene may be important in BEEC etiology.The study has refined the 22q11.2 locus associated with BEEC and has shown that the eight protein coding genes within this locus are expressed in human bladders.

Bladder infection affects a hundred million people annually, but our understanding of bladder immunity is incomplete. We found type 17 immune response genes among the most up-regulated networks in mouse bladder following uropathogenic Escherichia coli (UPEC) challenge. Intravital imaging revealed submucosal Rorc+ cells responsive to UPEC challenge, and we found increased Il17 and IL22 transcripts in wild-type and Rag2 -/- mice, implicating group 3 innate lymphoid cells (ILC3s) as a source of these cytokines. NCR-positive and negative ILC3 subsets were identified in murine and human bladders, with local proliferation increasing IL17-producing ILC3s post infection. ILC3s made a more limited contribution to bladder IL22, with prominent early induction of IL22 evident in Th17 cells. Single-cell RNA sequencing revealed bladder NCR-negative ILC3s as the source of IL17 and identified putative ILC3-myeloid cell interactions, including via lymphotoxin-β-LTBR. Altogether, our data provide important insights into the orchestration and execution of type 17 immunity in bladder defense.

Nitinol alloys have been widely used in manufacturing of vascular stents due to the outstanding properties such as superelasticity, shape memory, and superior biocompatibility. Laser cutting is the dominant process for manufacturing Nitinol stents. Conventional laser cutting usually produces unsatisfactory surface integrity which has a significant detrimental impact on stent performance. Emerging as a competitive process, fiber laser with high beam quality is expected to produce much less thermal damage such as striation, dross, heat affected zone (HAZ), and recast layer. To understand the process capability of fiber laser cutting of Nitinol alloy, a design-of-experiment based laser cutting experiment was performed. The kerf geometry, roughness, topography, microstructure, and hardness were studied to better understand the nature of the HAZ and recast layer in fiber laser cutting. Moreover, effect size analysis was conducted to investigate the relationship between surface integrity and process parameters.

Epstein-Barr virus (EBV) is a common gammaherpesvirus associated with various human malignancies. Antibodies with T cell receptor-like specificities (TCR-like mAbs) provide a means to target intracellular tumor- or virus-associated antigens by recognising their processed peptides presented on major histocompatibility complex (MHC) class I (pMHC) complexes. These antibodies are however thought to be relevant only for a single HLA allele. Here, we show that HLA-A*02:01-restricted EBV antigenic peptides EBNA1562-570, LMP1125-133 and LMP2A426-434 display binding degeneracy towards HLA-A*02 allelic microvariants, and that these pMHC complexes are recognised by anti-EBV TCR-like mAbs E1, L1 and L2 raised in the context of HLA-A*02:01. These antibodies bound endogenously derived pMHC targets on EBV–transformed human B lymphoblastoid cell lines expressing A*02:01, A*02:03, A*02:06 and A*02:07 alleles. More importantly, these TCR-like mAbs mediated both complement-dependent and antibody-dependent cellular cytotoxicity of these cell lines in vitro. This finding suggests the utility of TCR-like mAbs against target cells of closely related HLA subtypes, and the potential applicability of similar reagents within populations of diverse HLA-A*02 alleles.

BACKGROUND: Vegetable oil-based polyols are a new class of renewable materials. The structure of oil-based polyols is very different from that of petrochemical polyols, and it is closely related to the structure of oils. The objective of this work was to analyze the structural heterogeneity of soy-based polyols and its effect on the properties of polyols and polyurethanes. RESULTS: A series of polyols with a range of hydroxyl numbers were prepared by hydroformylation and partial esterification of hydroxyls with formic acid. Polyols were reacted with diphenylmethane diisocyanate to obtain polyurethanes of different crosslinking density. Gelation was simulated using the Monte Carlo method with a calculated distribution of functionalities for each polyol. CONCLUSIONS: Most polyols are powerful crosslinkers since weight average functionality varied from 5 to 2.5 resulting in gel points from 53 to 83% conversion. Heterogeneity of polyols had a negative effect on mechanical properties of rubbery polyurethanes and this should be taken in account when designing polyols for flexible applications. This effect was not pronounced in glassy polyurethanes. Copyright © 2007 Society of Chemical Industry

Two types of soy polyols have been prepared, one with secondary OH groups resulted from epoxidation of soybean oil followed by methanolysis (polyol type I) and the other with primary OH groups created from hydroformylation of soybean oil followed by hydrogenation (polyol type II). Cast polyurethane resins were prepared from these two types of polyols with Isonate 2143L, and rigid polyurethane foams were prepared from a blend of soy polyol and glycerol with PAPI 2901. Polyol II is much more reactive than polyol I towards polyurethane formation. This is evidenced from studies on polyurethane gel-times, glass transitions and rigid foam mechanical strengths. The reaction for the polyurethane formation is more complete for polyol II resulted from its higher reactivity than polyol I, although a less rigid polyurethane material is resulted from polyol II than from polyol I. Polyol type II also requires lower amounts of catalysts for rigid foam formulation. Both rigid foam systems produce foams having the required mechanical strength. The polyol II foam system behaves much like conventional rigid foam systems where the strength are proportional to system OH content, while the less reactive polyol I system does not.

The formation of oxazolidone from 9,10-epoxyoctadecane and phenylisocyanate was studied. One branch of epoxidized vegetable oil with one epoxy group per chain corresponds to 9,10-epoxyoctadecane. This model could explain the probability of oxazolidone formation from natural oil-derived epoxides. Epoxidized natural oils are TG consisting of glycerin and three FA with or without one to three epoxy groups in the middle of the chain. To study oxazolidone formation from an internal epoxy group without possible interference from the side reactions on the ester group, 9,10-epoxyoctadecane was selected as the most appropriate model compound. Epoxy groups in the middle of allong aliphatic chain are of low reactivity toward isocyanates, and preparation of oxazolidones requires fairly harsh conditions such as high temperatures and catalysts, which also promote side reactions. The dominant side reaction is rearrangement of the epoxy groups. We found that the direction and magnitude of the rearrangement and the yield of any particular product depended on the catalyst used. Lithium chloride, aluminum trichloride, and zinc iodide catalyzed oxazolidone formation, along with the catalysis of side reactions such as ketone and carbonate formation. Aluminum trichloride showed the highest conversion of 9,10-epoxyoctadecane to oxazolidone. Aluminum triisopropoxide, triphenylantimony iodide, and imidazole did not catalyze the formation of oxazolidone. They were effective as catalysts of epoxy group rearrangement and promoted the formation of hydroxyl, ketone, and carbonate compounds. Hydroxyl groups reacted with isocyanate to produce urethane.

The hydroformylation of vegetable oils (soybean, high oleic safflower, safflower, and linseed) and model compounds (methyl linoleate, methyl oleate, triolein, and trilinolein) using Rh(CO)2Acac ((acetylacetonato)dicarbonylrhodium(1)) as the catalyst precursor in the presence of triphenylphosphine (TPP) or (PhO)3P converted the olefins to polyaldehydes in quantitative yield. The reaction rate expressed as either initial rate or maximum turnover frequency (TOF) correlates with the olefin concentration of the substrate independent of the type of dominant triglyceride in vegetable oils. The relative rate constants (ko/kl) between methyl oleate and methyl linoleate at 90 °C and 1000 psig measured separately (2.4) and measured competitively in a mixture (0.90±0.08) indicate the formation of a π-allyl complex of the catalyst with the diolefin, methyl linoleate. The relative rate constants (ko/kl) of triglycerides (triolein and trilinolein) measured separately (1) and measured competitively in a mixture (0.94±0.06) do not indicate any significant effect from π-allyll complex formation on the reaction speeds of vegetable oils. The co-catalyst, (PhO)3P, showed a lesser reactivity compared to TPP in contrast to the rates of bulky phosphite ligands reported in the literature.

This paper compares physical and mechanical properties of polyurethanes derived via the hydroformylation approach and is a part of our study on the structure–property relationships in polyurethanes created from vegetable oils. The double bonds of soybean oil are first converted to aldehydes through hydroformylation using either rhodium or cobalt as the catalyst. The aldehydes are hydrogenated by Raney nickel to alcohols, forming a triglyceride polyol. The latter is reacted with polymeric MDI to yield the polyurethane. Depending on the degree of conversion, the materials can behave as hard rubbers or rigid plastics. The rhodium-catalyzed reaction afforded a polyol with a 95% conversion, giving rise to a rigid polyurethane, while the cobalt-catalyzed reaction gives a polyol with a 67% conversion, leading to a hard rubber having lower mechanical strengths. Addition of glycerine as a cross-linker systematically improves the properties of the polyurethanes. The polyols are characterized by DSC. The measured properties of polyurethanes include glass transition temperatures, tensile strengths, flexural moduli, and impact strengths.

Both HCFC- and pentane-blown rigid polyurethane foams have been prepared from polyols derived from soybean oil. The effect of formulation variables on foam properties was studied by altering the types and amounts of catalyst, surfactant, water, crosslinker, blowing agent, and isocyanate, respectively. While compressive strength of the soy foams is optimal at 2 pph of surfactant B-8404, it increases with increasing the amount of water, glycerin, and isocyanate. It also increases linearly with foam density. These foams were found to have comparable mechanical and thermoinsulating properties to foams of petrochemical origin. A comparison in the thermal and thermo-oxidative behaviors of soy- and PPO-based foams revealed that the former is more stable toward both thermal degradation and thermal oxidation. The lack of ether linkages in the soy-based rather than in PPO-based polyols is thought to be the origin of improved thermal and thermo-oxidative stabilities of soy-based foams. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 467–473, 2000

Four polyols were prepared by a ring opening of epoxidized soybean oil with HCl, HBr, methanol, and by hydrogenation. Two series of polyurethanes were prepared by reacting the polyols with two commercial isocyanates: PAPI and Isonate 2143L. Generally, the properties of the two series were similar. The crosslinking density of the polyurethane networks was analyzed by swelling in toluene. Brominated polyols and their corresponding polyurethanes had the highest densities, followed by the chlorinated, methoxylated, and hydrogenated samples. The polyurethanes with brominated and chlorinated polyols had comparable glass transition and strength, somewhat higher than the polyurethane from methoxy containing polyol, while the polyurethane from the hydrogenated polyol had lower glass-transition and mechanical properties. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4062–4069, 2000

Four polyols intended for application in polyurethanes were synthesized by oxirane ring opening in epoxidized soybean oil with hydrochloric acid, hydrobromic acid, methanol, and hydrogen. The structures of the polyols were characterized by spectroscopic, chemical, and physical methods. The brominated polyol had 4.1 hydroxy groups, whereas the other three polyols had slightly lower functionality. The densities, viscosities, viscous-flow activation energies, and molecular weights of the polyols decreased in the following order: brominated > chlorinated > methoxylated > hydrogenated. All the polyols were crystalline solids below their melting temperature, displaying multiple melting peaks. The methoxylated polyol was liquid at room temperature, whereas the other three were waxes. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3900–3910, 2000

A series of polyurethanes from polyols derived from soybean, corn, safflower, sunflower, peanut, olive, canola, and castor oil were prepared, and their thermal stability in air and nitrogen assessed by thermogravimetric analysis, FTIR, and GC/MS. Oil-based polyurethanes generally had better initial thermal stability (below 10% weight loss) in air than the polypropylene oxide-based polyurethane, while the latter was more stable in nitrogen at the initial stage of degradation. If weight loss at a higher conversion is taken as the criterion of stability, then oil polyurethanes have better thermal stability both in air and in nitrogen. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1723–1734, 2000

Three platinum(II) bis(β-diketonate) complexes are highly active for photocatalytic hydrosilation cross-linking of oligo[(methylsilylene)methylene] with tetravinylsilane. Platinum(II) bis(benzoylacetonate), platinum(II) bis(trifluoroacetylacetonate), and platinum(II) bis(benzoyltrifluoroacetonate) are photoactivated by visible light for catalysis, while platinum(II) bis(hexafluoroacetylacetonate) can be used as a thermal catalyst. Kinetic data from FT-IR and UV−visible spectroscopies characterizing Si−H bond conversion and catalyst photolysis are reported.

The complex bis(acetylacetonato)platinum(II) was activated by UV light in liquid mixtures of oligo[(methylsilylene)methylene](OMSM) leading to rapid solidification and the formation of polycarbosilane with a crosslinked structure. A hydrosilation catalyst is produced by irradiation of this complex which promotes chain extension at OMSM silicon hydride sites with the additive tetravinylsilane. Dihydridosilicon end groups on the oligomer are necessary for rapid photocuring. The crosslinked polymers were pyrolyzed under inert conditions giving 70% yields of β-silicon carbide ceramic char with an overall carbon to silicon ratio of 1.79 to 1. Films of OMSM resin were spin-coated onto silicon wafers, cured, and pyrolyzed. Images on the film surfaces were retained in shape and dimension after pyrolysis.

Engagement of the T cell antigen receptor results in both its phosphorylation and its ubiquitination. T cell antigen receptor ubiquitination was evaluated in Jurkat, a well characterized human T leukemia cell line. Treatment of cells with the tyrosine kinase inhibitor herbimycin A resulted in an inhibition of receptor ubiquitination. Consistent with this, pervanadate, which increases cellular tyrosine phosphorylation, enhanced receptor ubiquitination. A requirement for receptor-mediated tyrosine kinase activity for ubiquitination was confirmed in cells lacking the tyrosine kinase p56lck and also in cells that are defective in expression of CD45, a tyrosine phosphatase that regulates the activity of p56lck. The need for tyrosine kinase activation for ubiquitination was not bypassed by directly activating protein kinase C and stimulating endocytosis of receptors. These observations establish ubiquitination of the T cell antigen receptor as a tyrosine kinase-dependent manifestation of transmembrane signaling and suggest a role for tyrosine phosphorylation in the ligand-dependent ubiquitination of mammalian transmembrane receptors.

Polystyrene-block-poly(2-cinnamoylethyl methacrylate) (PS-b-PCEMA) formed micelles in THF/cyclohexane or chloroform/cyclohexane mixtures with the PCEMA block as the core. Depending on the relative length of the PS and PCEMA block, star and crewcut micelles were prepared. Upon UV irradiation, the PCEMA block selectively cross-linked to form star polymers and nanospheres from the corresponding star and crewcut micelles. The cross-linked micelles were characterized by solution and solid-state NMR, FTIR, GPC, TEM, and dynamic and static light scattering.

Polystyrene-block-poly(2-cinnamoylethyl methacrylate) (PS-b-PCEMA) polymers of different asymmetric ratios, β, and numbers, m, of CEMA units were synthesized and characterized. In cyclopentane/THF mixtures, the polymers were adsorbed by silica mainly via the PCEMA block in the brush conformation. For samples with β values greater than 4, their surface adsorption data could be well explained by the theory of Marques et al. for diblock adsorption from micelle solutions in the van der Waals−buoy regime. This represents the first experimental confirmation of such a scaling relation. On silver surfaces, the PCEMA block was the main adsorbing species for samples with small β and large m, and both the PS and PCEMA blocks adsorbed for samples with large β and small m values. As polymer brushes are not formed from certain polymers, the data of polymer adsorption by silver did not follow the scaling relation of Marques et al.

Polystyrene-block-poly(2-cinnamoylethyl methacrylate) (PS-b-PCEMA) of different block lengths have been synthesized. These polymers were adsorbed via the anchoring of the insoluble PCEMA block on silica, in the brush conformation, from cyclohexane/THF or cyclopentane/THF mixtures when cyclohexane or cyclopentane contents were high. The adsorbed amount could be increased or decreased by increasing or decreasing the cyclohexane or cyclopentane content. In a given solvent mixture, number surface coverages ρ∞ increased as n/m decreased, where n and m are the numbers of repeat units for the PS and PCEMA blocks, respectively. The trend that ρ∞ increased with decreasing n/m is contradictory to previous experimental observations but can be well explained by the scaling relation derived by Marques et al. for block copolymer adsorption from a micellar solution in the buoy-dominated regime.

Molecular weights (M) of organonickel polymers -[Ni(PMePh 2 ) 2 -1,4-C 6 F 4 -Ni(PBu 3 ) 2 ]-1,4-C 6 F 4 ] n - and -(Ni(PMePh 2 ) 2 -4,4'-C 12 F 8 ] n - have been obtained from GPC traces using both a direct calibration (relative to polystyrene standards) and a «universal» calibration (independent of the standards' nature). The universal method, requiring intrinsic viscosity data, produced M values consistent with light scattering measurements, while the direct method produced M values substantially too low. Using [η]= KM α and an iterative data-fitting procedure gave α= 1.5 for both polymers, and dilute-solution viscosity measurements revealed [η] to be independent of the solvent nature; both observations indicate that these polymers possess a rodlike structure. The GPC behavior of 13 related organonickel oligomeric species (X-[Ni(PR 3 ) 2 Ar F ] n -H, where n= 1-4, Z= ArFH or Br, ArF= 1,4-C 6 F 4 or 4,4'-C 12 F 8 , and R= Me, n-Bu, or Ph) was consistent with the polymer performance, in that all oligomers eluted at a given retention time possessed higher MW than did polystyrene eluted at the same time. This is due to the high repeating unit mass which counteracts the expected effect of their rigid-rod shapes. While differences in the fluoroaryl bridging units were found to have no effect on the retention times of the oligomers, separate curves were defined when ancillary PR 3 ligands were uniformly different (i.e., PMePh 2 vs PBu 3 ). Oligomers having fixed PR 3 ligands belonged to one of those two GPC curves which is always the one corresponding to the PR 3 at the terminal nickel atoms

The synthesis and characterization of five novel organonickel-organosilicon alternating copolymers having the repeating unit C6F4Ni‘PBu3’2C6F4SiR2 [where SiR2 = SiMe2, SiMe‘Hex’, SiPh2, SiMe2OSiMe2, and SiMe2‘CH2’6SiMe2] are reported. The model compounds Ni‘PR3’2‘1,4-C6F4SiMe3’2‘PR3 = PMePh2 or PBu3’ were prepared via reactions of Ni‘PR3’2‘1,4-C6F4Li’2 with 2 equiv of SiMe3Cl, and were characterized by conventional analytical and spectroscopic measurements. The Polymers were prepared from the reactions of Ni‘PBu3’2‘1,4-C6F4Li’2 with 1 equivalent of SiMe2Cl2 ‘polymer 1, Mw = 15,800’, SiMe ‘Hex’ Cl2 ‘polymer 2, Mw = 7300’, SiPh2Cl2 ‘polymer 3, Mw = 8600’, O‘SiMe2Cl’2 ‘polymer 4, Mw = 13,900’ and ‘CH2’6‘SiMe2Cl’2 ‘polymer 5, Mw = 19,700’. The molecular weights for each polymer were fully determined by both GPC and VPO. The multinuclear ‘1H-, 19F-, and 31P [1H]’-NMR, FTIR, and UV-Visible spectroscopic data for each polymer unambiguously establishes its repeating unit structure. The observations indicate that introduction of the silyl or siloxane units into the organonickel backbones has remarkably decreased the chain rigidity of the organonickel-organosilicon polymers compared to their rigid rod organonickel analogues ‘i.e., [C6F4Ni‘PR3’2]n’. © 1994 John Wiley & Sons, Inc.

The novel diol monomer, α,α,α′,α′-tetramethyl-1,4-tetrafluorobenzenedimethanol, has been synthesized by a convenient route which involves the addition of acetone to 1,4-dilithiotetrafluorobenzene and can be purified by washing with hexanes. It does not directly undergo condensation polymerizations with diacid chlorides. Its disodium salt, prepared by its reaction with sodium hydride, similarly fails to undergo such polymerizations readily. However, the dilithium salt, prepared in situ by the reaction of the title diol with 2 equiv of n-butyllithium in tetrahydrofuran, is suitable for the preparation of various classes of condensation polymers. Four polyesters and one polycarbonate derived from the reactions of the dilithium salt of the diol with adipoly dichloride, sebacoyl dichloride, isophthaloyl dichloride, terephthaloyl dichloride, and phosgene and two polyurethanes derived from its reactions with tolylene-2,4-diisocyanate and methylene-di-1,4-phenyl diisocyanate were prepared. Each was fully characterized by GPC, NMR, IR, and UV-visible spectroscopies, and the results of these studies are reported herein. © 1993 John Wiley & Sons, Inc.

The development of biodegradable implants has had a beneficial effect on in-vivo treatment of patients with various bone ailments. Currently, biodegradable implants are mainly made of polymers, such as PLA or PMMA. However, these polymer based implants usually have unsatisfactory mechanical strength and are prone to considerable amounts of wear [1]. An alternative to polymers is a biodegradable magnesium-calcium (Mg-Ca) alloy which has the ability to gradually dissolve and absorb into the human body after implantation. The similar properties of Mg to bone indicate it is an ideal implant material to minimize the damaging effects of stress shielding. The critical issue that hinders the application of Mg implants is poor corrosion resistance to human body fluids. Sequential laser shock peening (LSP) of a biodegradable Mg-Ca alloy was initiated to create a superior surface integrity for improving implant performance. LSP is an innovative surface treatment method to impart deep compressive residual stresses across a broad area of an implant. The high compressive residual stress has great potential to slow corrosion rates and improve wear and fatigue performance. Also, LSP produces a unique surface topography. Structural surface modifications are an effective way to alter the implant/tissue interface in order to improve biocompatibility.Copyright © 2010 by ASME

Useful composite matrix materials have been prepared from a series of soybean oils. Their properties are primarily affected by crosslink density. The utility of these resins was demonstrated on two series of laminates prepared from two types of polyols and several types of reinforcements: glass fabric, carbon fiber, polyester, and cotton and jute fabrics. Polyurethane matrix resins are a viable alternative to epoxy and polyester matrix resins and they are already being used commercially in selected farm combine and automotive applications.

Two polyols were prepared from soybean oil, one by epoxidation route and the other via hydroformylation. The polyol obtained by epoxidation has secondary groups and has a gel time of more than one hour when reacted with crude MDI to produce polyurethanes. Hydroformylated polyol has a gel time with MDI of several minutes and is more suitable for reinforced reaction injection molding (RRIM). The first group of polyurethanes had a glass transition close to 80 °C while the hydroformylated gave about 30 degrees lower Tg and comparable strength but higher elongation. Adding glycerin as the crosslinker could increase both Tg and strength. Two series of laminates were prepared using several types of glass fabric, carbon fiber, polyester, cotton and jute fabrics r as reinforcements. Hydroformylated polyol based polyurethane composites were softer, with lower Tg, modulus and strength. Composites with organic fibers were lighter and more flexible than the glass reinforced samples. For comparison glass reinforced epoxy and polyester were prepared and tested. Organic fibers gave lower stiffness and strength than the corresponding glass or carbon fiber. Although the neat polyester and epoxy resins had somewhat higher strengths than the polyurethanes from soybean oil, mainly due to the higher crosslinking density, the composites from the soy oil-based resin displayed comparable or better properties. Glass transition and mechanical properties of the soy-based polyurethanes was varied from about 70 °C to 140 °C with added crosslinkers. Processing time of the soy-polyurethanes resins was shorter than that of the other two resins.