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The selective catalytic synthesis of limonene‐derived monofunctional cyclic carbonates and their subsequent functionalisation via thiol–ene addition and amine ring‐opening is reported. A phosphotungstate polyoxometalate catalyst used for limonene epoxidation in the 1,2‐position is shown to also be active in cyclic carbonate synthesis, allowing a two‐step, one‐pot synthesis without intermittent epoxide isolation. When used in conjunction with a classical halide catalyst, the polyoxometalate increased the rate of carbonation in a synergistic double‐activation of both substrates. The cis isomer is shown to be responsible for incomplete conversion and by‐product formation in commercial mixtures of 1,2‐limomene oxide. Carbonation of 8,9‐limonene epoxide furnished the 8,9‐limonene carbonate for the first time. Both cyclic carbonates underwent thiol–ene addition reactions to yield linked di‐monocarbonates, which can be used in linear non‐isocyanate polyurethanes synthesis, as shown by their facile ring‐opening with N‐hexylamine. Thus, the selective catalytic route to monofunctional limonene carbonates gives straightforward access to monomers for novel bio‐based polymers., Biopolymers: The selective catalytic synthesis of limonene‐derived monofunctional cyclic carbonates and their subsequent functionalisation via thiol–ene addition and amine ring‐opening is reported. The selective catalytic route to monofunctional limonene carbonates gives straightforward access to monomers for novel bio‐based polymers.

Titanium(IV) complexes of amino-tris(phenolate) ligands (LTiX, X = chloride, isopropoxide) together with bis(triphenylphosphine)iminium chloride (PPNCl) are active catalyst systems for the ring-opening copolymerization of carbon dioxide and cyclohexene oxide. They show moderate activity, with turnover frequency values of ∼60 h–1(0.02 mol % of catalyst, 80 °C, 40 bar of CO2) and high selectivity (carbonate linkages >90%), but their absolute performances are lower than those of the most active Ti(IV) catalyst systems. The reactions proceed with linear evolution of polycarbonate (PCHC) molar mass with epoxide conversion, consistent with controlled polymerizations, and evolve bimodal molar mass distributions of PCHC (up toMn= 42 kg mol–1). The stoichiometric reaction between [LTiOiPr] and tetraphenylphosphonium chloride, PPh4Cl, allows isolation of the putative catalytic intermediate [LTi(OiPr)Cl]−, which is characterized using single-crystal X-ray diffraction techniques. The anionic titanium complex [LTi(OR)Cl]−is proposed as a model for the propagating alkoxide intermediates in the catalytic cycle.

A stereoselective, solvent-free ring-opening polymerisation (ROP) of lactide (LA) in supercritical carbon dioxide (scCO2) is reported for the first time. The key aim is to exploit scCO2 to lower the temperature of traditional melt polymerisations, lowering the energy requirement and leading to cleaner polymeric materials. We have utilised a zirconium amine-trisphenolate initiator-stereoselective catalyst [(iPrO)Zr(OPh(tBu)2-CH2)3N] to yield highly heterotactic poly(lactide) (PLA) homopolymer (Pr = 0.74–0.84) from rac-LA, demonstrating control of the PLA microstructure in scCO2. In addition, high monomer conversion (86–93%) was achieved in short reaction time (1 h), affording poly(lactide) with a very low degree of transesterification and narrow molecular weight distribution. Most importantly, all the reactions were performed at only 80 °C, almost 100 °C lower than the conventional melt process (typically performed at 130–180 °C), representing a very significant potential energy saving.

A tungsten-based polyoxometalate catalyst employing aqueous H2O2 as a benign oxidant has been used for the solvent free catalytic epoxidation of the trisubstituted alkene bonds of a wide range of biorenewable terpene substrates. This epoxidation protocol has been scaled up to produce limonene oxide, 3-carene oxide and α-pinene oxide on a multigram scale, with the catalyst being recycled three times to produce 3-carene oxide. Epoxidation of the less reactive disubstituted alkene bonds of terpene substrates could be achieved by carrying out catalytic epoxidation reactions at 50 °C. Methods have been developed that enable direct epoxidation of untreated crude sulfate turpentine to afford 3-carene oxide, α-pinene oxide and β-pinene oxide. Treatment of crude epoxide products (no work-up) with a heterogeneous acid catalyst (Amberlyst-15) results in clean epoxide hydrolysis to afford their corresponding terpene-anti-diols in good yields.

Cyclic polymers have long been reported in the literature, but their development has often been stunted by synthetic difficulties such as the presence of linear contaminants. Research into the synthesis of these polymers has made great progress in the past decade, and this review covers the synthesis, properties, and applications of cyclic polymers, with an emphasis on bio-based aliphatic polyesters. Synthetic routes to cyclic polymers synthesized from bioderived monomers, alongside mechanistic descriptions for both ring closure and ring expansion polymerization approaches, are reviewed. The review also highlights some of the unique physical properties of cyclic polymers together with potential applications. The findings illustrate the substantial recent developments made in the syntheses of cyclic polymers, as well as the progress which can be made in the commercialization of bio-based polymers through the versatility this topology provides.

An eight-year-old female spayed Boston Terrier presented to the North Carolina Veterinary Hospital with glaucoma in the left eye (OS). Initial ophthalmic examination revealed moderate ocular hypertension, a diffusely and markedly shallow anterior chamber with anteriorly displaced iris and lens, vitreal prolapse, and a normal iridocorneal angle (ICA) morphology. The patient displayed a paradoxical response to topical latanoprost with an increase in intraocular pressure. These examination findings led to a putative diagnosis of spontaneous aqueous humor misdirection syndrome (AHMS). The patient was successfully managed with topical carbonic anhydrase inhibitors (CAIs) and apraclonidine for eight months until progressive ulcerative keratitis necessitated enucleation of the affected globe. Histopathology and high-field magnetic resonance imaging (MRI) of the enucleated globe did not identify an underlying cause for the glaucoma. This case suggests that AHMS should be considered in dogs presenting with a shallow anterior chamber, vitreal prolapse, increased intraocular pressure, and no other causes of glaucoma.

To investigate factors associated with long-term visual outcome in cats with hypertensive chorioretinopathy.Eighty-eight client-owned cats diagnosed with hypertensive chorioretinopathy.Medical records from cats with systemic hypertension and associated retinal lesions were reviewed.Most cats (61%) were blind in both eyes at presentation. Presence of menace response at last follow-up evaluation was positively correlated with presence of menace response at presentation (P = .0025), time to complete retinal reattachment (P.0001), and gender (P = .0137). Seventy-six of 132 eyes (57.6%) that were blind at presentation regained some vision following treatment. At the time of last evaluation, 101/176 eyes (60%) had a positive menace response, while 34/46 (74%) eyes with a follow-up of6 months had a positive menace response. Eyes that had a menace response at presentation were 17 and 37 times more likely to have a menace response at last examination compared to eyes blind for less than 2 weeks and eyes blind greater than 2 weeks, respectively. Female cats were overrepresented (62.5% of cases), and male cats were 4.2 times more likely to be visual at time of last examination compared to female cats.With treatment, the prognosis for long-term vision in cats with hypertensive chorioretinopathy, even following complete retinal detachment, is good.

Presented herein is an operationally simple and reliable approach to the determination of comonomer reactivity ratios using continuous flow. The benefits of continuous-flow chemistry include the precise control of reaction time, heat transfer, and the ability to dynamically alter continuous variables within a single experiment. The flow system produces nine samples reacted to low conversions with systematically varied comonomer compositions in under one hour. The polymer compositions were fit to a model of terminal copolymerization resulting in point estimates for comonomer reactivity ratios. The continuous-flow system was validated by the determination of five comonomer reactivity ratios that provided good agreement with literature values. The method is demonstrated to streamline the determination of especially challenging comonomer systems, such as those with fast kinetics or disparate reactivity. Using sustainably-derived lignin-based methacrylates, our continuous-flow approach enabled the determination of reactivity ratios for three comonomer pairs that have not been previously reported. We envision the continuous-flow method will catalyze the further exploration of statistical copolymers in both batch and continuous flow.

A range of ligands based upon 2-(aminomethyl)piperidine have been successfully complexed to Mg(ii), Zn(ii) and group IV metal centres. These complexes have been characterised both in solution and solid state with different coordination geometries realised dependant on the nature of the ligand. For the Mg(ii) and Zn(ii) complexes, M(1-2)2, were isolated and analysed by DOSY NMR spectroscopy. These ligands also furnished diastereomeric group IV complexes, M(1-2)2(OiPr)2. Group IV salalen and salan complexes, M(4-5)(OR)2 were also found to be diastereomeric in nature, with either β-cis or α-cis geometriesrespectively. The tridentate ligand, 6H2, yielded five coordinate complexes with both Ti(iv) and Zr(iv). All complexes were screened for the ring opening polymerisation of rac-lactide under both solvent and melt conditions. For the Mg(ii) and Zn(ii) complexes, good activity was observed with Zn(1-2)2 demonstrating immortal polymerisation characteristics.

A high-yielding 4-step process for converting a naturally occurring terpene, β-pinene, into a substituted e-caprolactone is herein reported. Investigations into the ring-opening polymerisation and copolymerisation of this monomer are also described.

A new way to combine two different polymerisation reactions, using a single catalyst, results in efficient block polymer synthesis. The selective polymerisation of mixtures of L-lactide-O-carboxyanhydride and cyclohexene oxide, using a di-zinc catalyst in a one-pot procedure, allows the preparation of poly(L-lactide-b-cyclohexene carbonate). The catalysis near quantitatively recycles the carbon dioxide released during polyester formation into the subsequent polycarbonate block, with an atom economy of up to of 91%.

Chronic intestinal inflammation accompanies familial adenomatous polyposis (FAP) and is a major risk factor for colorectal cancer in patients with this disease, but the cause of such inflammation is unknown. Because retinoic acid (RA) plays a critical role in maintaining immune homeostasis in the intestine, we hypothesized that altered RA metabolism contributes to inflammation and tumorigenesis in FAP. To assess this hypothesis, we analyzed RA metabolism in the intestines of patients with FAP as well as APCMin/+ mice, a model that recapitulates FAP in most respects. We also investigated the impact of intestinal RA repletion and depletion on tumorigenesis and inflammation in APCMin/+ mice. Tumors from both FAP patients and APCMin/+ mice displayed striking alterations in RA metabolism that resulted in reduced intestinal RA. APCMin/+ mice placed on a vitamin A–deficient diet exhibited further reductions in intestinal RA with concomitant increases in inflammation and tumor burden. Conversely, restoration of RA by pharmacologic blockade of the RA-catabolizing enzyme CYP26A1 attenuated inflammation and diminished tumor burden. To investigate the effect of RA deficiency on the gut immune system, we studied lamina propria dendritic cells (LPDC) because these cells play a central role in promoting tolerance. APCMin/+ LPDCs preferentially induced Th17 cells, but reverted to inducing Tregs following restoration of intestinal RA in vivo or direct treatment of LPDCs with RA in vitro. These findings demonstrate the importance of intestinal RA deficiency in tumorigenesis and suggest that pharmacologic repletion of RA could reduce tumorigenesis in FAP patients. Cancer Immunol Res; 4(11); 917–26. ©2016 AACR.

A series of N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine (TOEEDH4) ligand precursors and their group 4 metal complexes have been prepared. The complexes have been characterized by single-crystal X-ray diffraction and 1H NMR spectroscopy, highlighting the ability to systematically vary the number of TOEED ligands within the system. Initial catalytic data for the solvent-free, ring-opening polymerization of rac-lactide (rac-LA), a promising degradable polymer produced from renewable resources, is reported. At 135 °C, it has been demonstrated that the activity of the complexes is enhanced by increasing the number of labile isopropoxide groups. When the temperature was further increased to 165 °C, all complexes demonstrated a far higher activity irrespective of the identity of the metal or number of labile initiator groups. Polymerization kinetics were monitored in real time using FT-IR spectroscopy with a diamond composite insertion probe and Ti4(TOEED)(OiPr)12 was demonstrated to convert over 95% of th...

Mycotoxins are naturally occurring environmental contaminants recognized worldwide in a variety of food and feed products. Produced as secondary metabolites by filamentous fungi, mycotoxins can have acute and chronic effects. Differing seasonal weather patterns and harvesting and storage conditions put corn grain at high risk for mycotoxin contamination. The objective of this study was to assess the risk of mycotoxin exposure posed to California livestock from whole corn. Random samples (n=50) of whole corn were collected and analyzed for 6 different mycotoxins, including aflatoxins, fumonisins, ochratoxins, trichothecenes (deoxynivalenol and T-2 toxin), and zearalenone. The samples represented a cross section of the corn entering California from various corn-growing states (n=43) as well as additional samples from California-grown corn (n=7). The experiment was a randomized sampling design. Over the course of a 6-mo period, 16 trains in California (100-110 railcars) and 5 California grain elevators were randomly sampled. Aflatoxins were detected in 14 samples, with 1 sample containing a concentration of 41.3 μg/kg (as-is basis), which was above the action level of 20 μg/kg for corn fed to dairy cattle. The average concentration of aflatoxins for the 13 samples below the regulatory action level was 8.69 μg/kg (range 4.67 to 13.82 μg/kg). Deoxynivalenol was found in 15 samples and averaged 553 μg/kg (range 340 to 1,072 μg/kg), which was below the federal advisory level of 5,000 μg/kg for grain fed to dairy cattle. Fumonisins were found in 38 samples and averaged 1,687 μg/kg (range 435 to 4,843 μg/kg), which was below the federal guidance level of 30,000 μg/kg in corn for dairy cattle. Ochratoxins, T-2 toxins, and zearalenone were not detected in any samples of whole corn. Fumonisins were the most prevalent mycotoxins found.

Tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. The reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. Continuous anaerobic fermentation was optimized resulting in the productivity of 2.4 g L⁻¹ h⁻¹ of 1,3-propanediol. Biphasic esterification of 1,3-propanediol was optimized to achieve ester yield of up to 75%. A hollow fibre membrane contactor with immobilized Rhizomucor miehei lipase was demonstrated for the continuous tandem fermentation-esterification process.

We report the rationalised design of aluminium initiators and their application for ROP of rac-lactide (rac-LA). A very minor change to the ligand backbone (imine reduction) to give secondary amines was found to have a dramatic effect on activity and selectivity with isotactic PLA being realised.

Herein we report the synthesis and characterisation of a series of salalen and salan ligands derived from 2-(aminomethyl)piperidine. Depending on the choice of starting salicylaldehyde, a bicyclic salan type ligand (1-3H2) or imino salalen type ligand (4-6H, 7-9H2) were prepared. The ligands were successfully complexed to group 4 metals and aluminium; with hafnium and zirconium octahedral complexes, M(1-3)2, were realised; whilst with aluminium tetrahedral and trigonal bipyramidal complexes, Al(1-9)Mex (x = 1,2), were isolated. The complexes have been characterised in solution via(1)H and (13)C{(1)H} NMR spectroscopy and in the solid state by X-ray crystallography. The group 4 complexes were observed to have a fac-fac arrangement of ligands and there were two isomers present when 3H2 was ligated. The imino aluminium complexes Al(7-9)Me were isolated as a mixture of diastereoisomers. The resultant complexes were trialed in the ring opening polymerisation of rac-lactide with both heterotactic and isotactic PLA being demonstrated. Tacticity was found to be dependent on the nature of the ligand and metal used; the M(1-3)2 complexes were generally found to have a heterotactic preference (Pr = 0.67-0.76) and the aluminium polymerisation outcome was dictated more by the steric influence of the ligand, particularly for Al(4/6)Me2/Al(7/9)Me.

Treatment of [Ti(OiPr)4] with trimethylsilyl triflate results in the formation of [Ti(OiPr)3(OTf)] (2) in high yield. Subsequent treatment of the triflate derivative 2 with a series of facially coordinating N3-donor ligands results in the production of a series of charge-separated metal alkoxide salts of the general formula [{L}Ti(OiPr) 3][OTf] {L = tris(pyrazolyl)methane (3a), 1,3,5-triethyl-1,3,5- triazacyclohexane (3b), 1,3,5-tribenzyl-1,3,5-triazacyclohexane (3c), 1,3,5-tris(p-fluorobenzyl)-1,3,5-triazacyclohexane (3d), and 1,3,5-tris[(1S)-1-phenylethyl]-1,3,5-triazacyclohexane (3e)}. The products were characterized by 1H and 13C NMR spectroscopy and in the case of 3a-c by single-crystal X-ray diffraction. Reaction of 2 with 1,3,5-triphenyl-1,3,5-triazacyclohexane results in the formation of complex 4 [{L′}2Ti(OiPr)2(OTf)2], which contains two 3,4-dihydroquinazoline ligands (L′), a result of catalytic activation of the triazacyclohexane ligands by [Ti(OiPr)3(OTf)] towards electrophilic aromatic substitution.

Tetraamine Me(6)TREN has been used as a scaffold support to provide coordinative saturation in the complexes PhCH(2)M⋅Me(6)TREN (M=Li, Na, K). The Li derivative displays a Li−−C σ interaction with a pyramidalized CH(2) both in the solid state and in solution, and represents the first example of η(4) coordination of Me(6)TREN to lithium. In the sodium derivative, the metal cation slips slightly towards the delocalized π electrons whilst maintaining a partial σ interaction with the CH(2) group. For the potassium case, coordinative saturation successfully yields the first monomeric benzylpotassium complex, in which the anion binds to the metal cation exclusively through its delocalized π system resulting in a planar CH(2) group.

One-step surfactant-free, water-droplet templating has been developed as a fabrication method for a poly(lactide-co-glycolide) (PLGA) film that can be used as a model to investigate the relationship between solvent, monomer ratio, polymer concentration and humidity on its structure. The resulting material is a honeycomb-structured film. Formation of this structure was highly sensitive to solvent, monomer ratio, polymer concentration and humidity. Surfactant-free, water-droplet templating thus allows investigation of fabrication parameters and that PLGA monomer ratio selection is important for scaffold structure but not for MG63 cell attachment and proliferation.

Treatment of [Ti(OiPr)4] with the sulfonyl-imine systems Tos2NH ([(p-Me-C6H4SO2)2NH]) and Tf2NH ([(CF3SO2)2NH]) results in the formation of the new Lewis acidic titanium sulfonyl-imide complexes [Ti(OiPr)2(O,O′-Tos2N)2] (1) and [Ti(OiPr)2(HOiPr)2(O-Tf2N)2] (2), respectively. The molecular structures of the complexes have been determined by single crystal X-ray diffraction. The reaction of [Ti(OiPr)3(OAr)] (Ar = 2,6-di-tert-butyl-4-methyl phenyl) with Tf2NH results in the formation of the dimeric complex [Ti(OiPr)3(O,O′-Tf2N)]2 (3), which has also been structurally characterised. The ability of the complexes to catalyst the Friedel–Crafts acylation of anisole has also been assessed.

An air and moisture stable C(3)-symmetric titanium(IV) triflate, supported by a tripodal amine-(tris-phenolate) ligand, has been synthesized and characterized by X-ray crystallography and shown to be a good Lewis acid catalyst for a range of aza-Diels-Alder, Diels-Alder, syn aldol, allylation, and alkylation reactions.

Two new group 4 initiators based on N,N′-Bis(2-hydroxybenzyl)ethylenediamine have been prepared and fully characterised via multi-nuclear NMR spectroscopy and single crystal X-ray diffraction studies. The complexes have been tested for the production of polylactide. The phenolate ligand complexes to Ti(IV) to generate the β-cis isomer in the solid-state. Whereas for Zr(IV) the isolated species (regardless of stoichiometery) is a diligated complex.

The bis-guanidino compound H2C{hpp}(2) (I; hppH = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) has been converted to the monocation [I-H](+) and isolated as the chloride and tetraphenylborate salts. Solution-state spectroscopic data do not differentiate the protonated guanidinium from the neutral guanidino group but suggest intramolecular "-N-H center dot center dot center dot N=" hydrogen bonding to form an eight-membered C3N4H heterocycle. Solid-state CPMAS N-15 NMR spectroscopy confirms protonation at one of the imine nitrogens, although line broadening is consistent with solid-state proton transfer between guanidine functionalities. X-ray diffraction data have been recorded over the temperature range 50-273 K. Examination of the carbon-nitrogen bond lengths suggests a degree of "partial protonation" of the neutral guanidino group at higher temperatures, with greater localization of the proton at one nitrogen position as the temperature is lowered. Difference electron density maps generated from high-resolution X-ray diffraction studies at 110 K give the first direct experimental evidence for proton transfer in a poly(guanidino) system. Computational analysis of I and its conjugate acid [I-H](+) indicate strong cationic resonance stabilization of the guanidinium group, with the nonprotonated group also stabilized, albeit to a lesser extent. The maximum barrier to proton transfer calculated using the Boese-Martin for kinetics method was 2.8 kcal mol(-1), with hydrogen-bond compression evident in the transition state; addition of zero-point vibrational energy values leads to the conclusion that the proton transfer is barrierless, implying that the proton shuttles freely between the two nitrogen atoms. Calculations determining the gas-phase proton affinity and the pK(a) in acetonitrile both indicate that compound I should behave as a superbase. This has been confirmed by spectrophotometric titrations in MeCN using polyphosphazene references, which give an average pK(a) of 28.98 +/- 0.05. Triadic analysis indicates that the dominant term causing the high basicity is the relaxation energy.

Although the transesterification reaction of triglycerides with alcohols (using acid or alkaline catalysts) is well known and practiced on a commercial scale, there is plenty of scope to improve this process. The turning of a batch into a continuous process, and the use of a catalyst that is more favourable to fatty acids in the feed, are challenges of particular interest. With these objectives in mind, results are presented of experiments in which a zinc amino acid complex [ZnL 2 ], was used as a catalyst. This was fixed onto a structured monolith support (cordierite), so as to enable the catalysts to be retained in a fixed bed. To advance this work, reaction experiments were performed in a 120 ml batch reactor, using 10 mm × 10 mm × 10 mm sections of catalyst coated monolith (1.1 mm square channels, 62 cells cm −2 ). With a 12:1 molar ratio of methanol and rapeseed oil (triglyceride), at 195 °C and 20 bar, and using 0.3 g of zinc catalyst (coated on a monolith), it was shown that 54% of the triglyceride was converted into biodiesel. This compares very favourably with a conversion of 69% in batch experiments, when 0.3 g of the catalyst was dispersed in the solution in the form of a very fine powder. Interestingly, it was also shown, that the cordierite monolith support on its own exhibited catalytic activity (27% conversion of the triglyceride).

Biodiesel is a renewable fuel derived from vegetable, animal, or waste oils. It is synthesized by the transesterification of triglycerides with either methanol or ethanol. The fatty acid profile of biodiesel differs depending upon the feedstock of the derived fuel and is the major factor in determining the properties of the fuel. Using biodiesel blends decreases hydrocarbon, particulate matter, and CO emissions while increasing fuel consumption and NOx emissions. This effect is dependent upon not only the blend ratio but also the fatty acid profile of the biodiesel. Current techniques to determine the fatty acid profile of biodiesel samples are both time-consuming and expensive; however, by measurement of three simple physical properties (viscosity, density, and the refractive index) and a comparison of the values to known standards, it is possible to create a model that can accurately predict both the average chain length and degree of unsaturation.

Schiff base ligands (L1H–L8H) have been prepared and complexed to ZnII centres. All eight complexes have been characterised by single-crystal X-ray diffraction methods, multinuclear NMR spectroscopy and elemental analysis. It was shown that for L1H and L2H trimetallic complexes of the form Zn3(OAc)4(L1–2)2 were isolated. However, for L3H to L7H monometallic complexes were formed, Zn(L3–7)2. For L8H a trimetallic complex was also isolated with the same stoichiometry as Zn3(OAc)4(L1–2)2 but a different coordination motif was detected. The Schiff base ligand L1H was anchored to silica and treated with Zn(OAc)2·2H2O to form the heterogeneous ZnII system. This was characterised by 13C{1H} CP/MAS NMR spectroscopy. All homogeneous and heterogeneous catalysts were assessed for the ring-opening polymerisation of rac-lactide at 130 °C in the absence of solvent, using unsublimed monomer. All catalysts offered good conversions and a moderate degree of control.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Reaction of 2-formyl-aryl-boronic acids with 1,2-amino alcohols results in dynamic covalent self assembly to quantitatively afford tetracyclic macrocyclic Schiff base boracycles containing bridging boron–oxygen–boron functionality.

Canine leishmaniosis (CL) can present with multiple clinical signs and ocular disease is reported to occur in almost 25% of affected dogs. The purpose of the present study was to characterize the nature of inflammation within the eyes of dogs with leishmaniosis and to determine whether parasites were present in these lesions. Eyes from 60 dogs with confirmed leishmaniosis that died or were humanely destroyed over a 4 year period were included in the study. Sections of formalin-fixed globes were stained with haematoxylin and eosin (HE) and subjected to immunohistochemistry using a Leishmania-specific antibody. Clinically evident ocular signs were present in 15 of 60 dogs (13 bilaterally and 2 unilaterally). Thirty-five of 60 dogs received some form of anti-protozoal treatment. In 36 of 120 eyes (30%) a granulomatous inflammatory infiltrate was found and in 32 of 120 eyes (26.6%) the parasite was identified immunohistochemically within the globe. Ocular tissues affected, in order of frequency, were conjunctiva and limbus, ciliary body, iris, cornea, sclera and iridocorneal angle, choroid and the optic nerve sheath. Different microscopical patterns were defined in each of these structures. Leishmania organisms and associated inflammation can be found in different ocular tissues, accounting for some of the ocular clinical signs described for this disease.

In this paper we investigate the coordination of various oximes (C N–OH) with titanium(IV). We have chosen three ligands (1H2–3H2) with a phenolic moiety and one ligand 4H with a pyridine group. It was shown that ligands 1H2 to 3H2 react with Ti(OiPr)4 to form complexes with a generic formula Ti3(L)2(OiPr)8, where each oxime bridges between the three titanium centres. Interestingly, these complexes are clusters made up of three titanium atoms, with one titanium centre sitting above the other two. This titanium centre can be thought of as a trapped Ti(OiPr)4 molecule, 1H and 13C NMR spectroscopy indicates that the solid-state structures are maintained in solution. Subtle differences between the three X-ray structures are discussed. Ligand 4H readily reacts with Ti(OiPr)4 forming a dimeric species, Ti2(4)4(OiPr)4, where the titanium centres are linked by bridging isopropoxide moieties.

The structure of the first tetrameric α-lithiated N-phenylphosphazene has been determined in the solid state and shown to persist in toluene solution, an observation that gives insight into the variation in stereoselectivity found for reactions of α-lithiated phosphazenes with aldehydes.

The coordination modes of various azines (C=N-N=C) and hydrazones (C=N-NR2) with titanium(IV) are investigated. Five ligands were studied, two hydrazones 1H-2H and three azines 3H(2)-5H(2), and it was found that hydrazones form monomers and azines form dimers in the solid state. The hydrogen-bonded arrays observed for the hydrazones were significantly different for the two ligands, with one forming a ribbon like structure and the other a chain. For the azines the supramolecular structures are also discussed. A pronounced twist is observed in the azine ligand upon complexation to the metal centre, which is rationalised in terms of the favourable interactions observed in the solid-state. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

This paper reports the reaction of Ti(OiPr)(4) with a series of Schiff-base ligands. The Schiff-base proligands 1a-I are synthesised by the condensation of salicylaldehyde with a range of primary alkylamine and aniline derivatives. The treatment of 1a-f with Ti(OiPr)(4) yields the octahedral bis(aryloxyimine)Ti(OiPr)2 complexes 2a-f X-ray crystal structure analysis of 2c, 2d and 2e reveals complexes with a trans-aldiminato oxygen atom and cis-N,cis-alkoxide ligand arrangement about the central metal atom. The reactions of Ti(OiPr)4 with the ligands 1g and 1h result in a sterically induced ligand rearrangement to form the octahedral complexes 2g and 2h, also characterised by X-ray diffraction experiments, in which the nitrogen atoms of the O,N-chelate are now trans-orientated at the titanium centre. H-1 NMR analysis reveals significant deshielding of the isopropoxide methine proton, induced by this coordination mode. In contrast, reactions of 1i and 1j with Ti(OiPr)4 result in the formation and isolation of the complexes 2i and 2j. X-ray crystal structure analysis shows complex 2j to have a previously unobserved ligand orientation, in which both ligands are trans-orientated, with respect to the aldimmato oxygen atoms, about the titanium centre, but steric bulk of the ligand inhibits the bidentate coordination of both O,N-ligands. Further increase in the steric bulk of the imine substituent results in a reduced reactivity for ligands 1k and 11, such that Ti(OiPr)4 reacts with 1k to form the dimeric mono(Schiff-base) complex 2k (characterised by X-ray analysis). No reaction is observed for 11. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).

The synthesis, solid-state and solution structure of a magnesium amine bis(phenolate) complex [Mg{(O-2,4-tBu2C6H2-6-CH2N(Me)CH2}2(C6H5CH3)1.5]2 4-Mg is reported. The complex was prepared by combining MgBu2 with an equimolar amount of the parent bis(aminophenol) at ambient temperature in toluene. In the solid-state, the complex exists as a dimer. Each Mg centre is five-coordinate – bonding to one μ1[sbnd]O, two μ2[sbnd]O and two N moieties. NMR spectroscopy indicates that the solid-state structure is maintained in solution. Complex 4-Mg was investigated as a catalyst for ring opening polymerisation (ROP) of e-caprolactone and L-lactide at both ambient and elevated temperatures, but was shown to be inactive, presumably as a direct result of the high steric bulk of the amine bis(phenolate) ligand.

Reactions between the icosahedral carboranes 1,2-C2B10H12 (1), 1,7-C2B10H12 (2) and 1,12-C2B10H12 (3) and the iminophosphorane HNP(NMe2)3 (4) are described that have afforded a variety of products whose structures have been characterised by X-ray diffraction. They include the adduct between (1) and (4), C2B10H12·HNP(NMe2)3 (5) the 12-atom 14-skeletal pair supra-icosahedral nido structure of which illustrates an early step in the deboronation of ortho-carborane (1) by Lewis Bases, and the C–H⋯N hydrogen-bonded adducts of meta- and para-carborane with the iminophosphorane, [1,7-C2B10H12⋯HNP(NMe2)3] n and 1,12-C2B10H12 $$\cdot$$ 2HNP(NMe2)3. The iminophosphorane (4) readily converts ortho-carborane (1) into the nido anion [7,8-C2B9H12]− and less readily meta-carborane (2) into the nido-anion [7,9-C2B9H12]−, which have been isolated from solution as salts of the cations [H2NP(NMe2)3]+ or [{(Me2N)3PN}2BNHP(NMe2)3]+, the latter evidently incorporating a boron atom removed from the carborane cage. Adventitious presence of water in the attempted recrystallization of [{(Me2N)3PN}2BNHP(NMe2)3]+ [7,8-C2B9H12]− led to a salt of the cation [{(Me2N)3PNBN(H)P(NMe2)3}2O]2+. Other unexpected products isolated from reactions carried out under moist air included the salt [H2NP(NMe2) 3 + ]2[CO 3 2− ]·2B(OH)3 (from the reaction between 2 and 4) and the salt 1,12-C2B10H12·2H2NP(NMe2) 3 + HCO 3 − (from the reaction between 3 and 4).

The reactions of tcc-Ru(IMes)2(AsPh3)(CO)H2 (1, IMes = bis(1,3-(2,4,6-trimethylphenyl)imidazol-2-ylidene)) with HX substrates (X = OH, OEt, SH, SnPr) have been reinvestigated and shown to lead directly to the formation of the 16-electron species Ru(IMes)2(CO)(X)H (4-X). The fluoro analogue Ru(IMes)2(CO)(F)H (4-F) has also been synthesized, and X-ray and neutron diffraction studies show that this exhibits a square-pyramidal geometry with hydride in the axial site. Density functional calculations have been performed on one possible mechanism for the formation of 4-X from 1 with various HX (X = F, Cl, OH, SH, NH2, PH2, CH3, and SiH3), involving initial AsPh3/HX substitution followed by H-transfer to hydride and H2 loss. With X = SH, H-transfer in both tcc-Ru(IMes)2(CO)(H2S)(H)2 and ttt-Ru(IMes)2(CO)(H2S)(H)2 was considered and shown to be kinetically accessible and thermodynamically favored, suggesting that such dihydrides should not be stable with respect to this step. The calculations indicate that the eas...

The first Mukaiyama aldol reaction on mucohalic acid ( 1a / b ) has been achieved. Reaction of 1 with various ketene silyl acetals or silyl enol ethers in the presence of a Lewis acid provides the γ-substituted γ-butenolides in good to excellent yield.

Chiral fluorescent boronic acid 1 was found to be a highly enantioselective, chemoselective, and sensitive sensor for sugar acids, such as tartaric acid. Enantioselectivities (K(R)/K(S)) of up to 550:1, chemoselectivity up to 11,000:1, and sensitivities in the micromolar range with sensor 1 were observed. Single-crystal X-ray analysis was used to confirm the structure of the fluorescent species.

The crystal and toluene solution structure (X-ray, 1H, 7Li, 13C,31P NMR) of a mixed-anion lithium phosphazene-phenolate, 10, is a six-rung ladder consisting of two LiPCN units fused to a central Li2O2 core, which provides insight into the function of phosphazenyl-stabilized carbanions as reagents. The mixed aggregate showed decreased reactivity toward benzaldehyde with respect to the uncomplexed anion.

The structures of five substituted α,α′-trehalose trehalose derivatives have been determined, and these are compared with those of four previously published analogues. In 2,2′,3,3′,4,4′-hexaacetato-6,6′-bis-O-methylsulfonyl-α,α′-trehalose, C26H38O21S2, where the molecules lie across twofold rotation axes in the space group C2, a single C—H...O=S hydrogen bond links the molecules into sheets. 2,2′,3,3′,4,4′-Hexaacetato-6,6′-bis-O-(4-toluenesulfonyl)-α,α′-trehalose, C38H46O21S2, crystallizes with Z′ = 2 in the space group P212121 and a combination of three C—H...O hydrogen bonds, each having a carbonyl O atom as an acceptor, and a C—H...π(arene) hydrogen bond link the molecules into a three-dimensional framework. 2,2′,3,3′,4,4′-Hexaacetato-6,6′-diazido-α,α′-trehalose, C24H32N6O15, crystallizes as a partial ethanol solvate and three C—H...O hydrogen bonds link the substituted trehalose molecules into a three-dimensional framework. In 2,2′,3,3′-tetraacetato-6,6′-bis(N-acetylamino)-α,α′-trehalose dihydrate, C24H36N2O15·2H2O, the substituted trehalose molecules lie across twofold rotation axes in the space group P21212 and a three-dimensional framework is generated by the combination of O—H...O and N—H...O hydrogen bonds. The diaminotrehalose molecules in 6,6′-diamino-α,α′-trehalose dihydrate, C12H24N2O9.2(H2O), lie across twofold rotation axes in the space group P43212: a single O—H...N hydrogen bond links the trehalose molecules into sheets, which are linked into a three-dimensional framework by O—H...O hydrogen bonds.

The addition of LiBun to a toluene solution of Ph2P(O)N(CH2Ph)CH3 1 and 2,6-di-tert-butyl-4-methylphenol 5 leads to the formation of the mixed dimer [(Ph2P(O)N(CH2Ph)CH3) · LiOC6H2-2,6-{C(CH3)3}2-4-CH3) · C7H8]2 6. The single crystal X-ray structure shows that two lithium aryloxide moieties dimerize giving rise to a Li2O2 core in which each lithium atom is additionally coordinated to a phosphinamide 1 ligand. The multinuclear magnetic resonance study (1H, 7Li, 13C, 31P) indicates that the solid-state structure is preserved in toluene solution. Complex 6 may be considered as a model for the pre-complexation step preceding the metalation of phosphinamides by an organolithium base.

Objective To evaluate the ophthalmoscopic, fluorescein angiographic and light microscopic effects of diode laser retinopexy application in the tapetal and nontapetal fundus in the dog, and to ascertain appropriate laser power settings for production of photocoagulative lesions in these two regions. Animals studied Three adult female Beagle dogs. Procedures Laser burns were applied to selected areas in the fundus with an indirect headset delivery system using settings varying from 100 to 200 milliWatts (mW) and from 100 to 600 milliSeconds (mS) with total delivered energy ranging between 15 and 100 milliJoules (mJ). The dogs were then monitored by ophthalmoscopic examination and fluorescein angiography at regular intervals for 7–28 days. Histopathologic studies were performed at 7, 14 and 28 days after laser application. Results The diode laser produced ophthalmoscopically visible lesions in the nontapetal fundus with all laser settings used, and the appearance of these lesions corresponded to the energy levels used, and degree of pigment in the lased region. Gray-white colored lesions with minimal subsensory retinal edema were seen with settings as low as 100 mWatts/150 mSeconds. In the tapetal fundus, laser burns were more difficult to produce, less repeatable, and required higher energy levels. Laser burns appeared as bronze, dark green or black discolorations of the tapetum with varying degrees of subsensory retinal edema. Lesions were more reproducible and were achieved with lower settings in the tapetal area of the tapetal/nontapetal junction. Ophthalmoscopically, depigmentation and repigmentation of the RPE (nontapetal fundus) and degenerative changes in the overlying retina (tapetal fundus) developed in the laser burns over the 28-day study period. Fluorescein angiographic studies showed disruption of the blood–retinal barrier at the level of the RPE and fluorescein leakage into the subsensory retinal space was seen in most lesions at 24 h, was minimal at 3 days, and had resolved by 7 days. Histologically, grayish-white lesions in the nontapetal fundus, and bronze to small black lesions in the tapetal fundus were typically characterized by outer retinal necrosis and RPE migration. Gliosis was considered minimal, was confined to the retina, and no inflammatory cells were seen. Peripheral intense white lesions (nontapetum) and lesions with a black center (tapetal fundus) were characterized by more extensive panretinal and choroidal necrosis. Most of the nontapetal lesions and a few in the tapetal fundus showed the formation of a central retinal detachment. Conclusions The diode laser effectively produces lesions suitable for retinopexy in both the nontapetal, pigmented fundus and the tapetal fundus, although variably so in the latter region. Initial laser settings of 100–150 mW/200 mS for the pigmented fundus, and 150 mW/200–300 mS for the peripheral tapetal fundus are recommended, and the clinician should gradually increase time interval settings to achieve a grayish-white lesion in the nontapetum, and a bronze to slightly black lesion in the tapetal fundus. If possible, retinopexy should be applied to the peripheral tapetal area or tapetal/nontapetal junction.

The efficacy of chlorothalonil in controlling mycosphaerella blight in field pea was evaluated from 1998 to 2000 using 10 cultivars representing different leaf types, market classes, seed sizes, plant heights, and maturities. Significant differences ( P < 0.05) were observed among cultivars in disease severity, yield, 1000-seed weight (TSW), and seed infection each year. Cultivar × fungicide treatment interactions for these parameters were not significant in any of the 3 yr. Under both chlorothalonil treated and untreated conditions, Radley was the most resistant, while Carrera and Keoma were equally the most susceptible cultivars. A higher efficacy of chlorothalonil treatments was observed in 1999 when disease severity was greater than in 1998 or 2000. On average, chlorothalonil treatments reduced disease severity significantly in 1999 and 2000, but not in 1998. Overall, the fungicide increased yield by 6.4%, and TSW by 0.9–5.1%, which were significant in 1998 and 1999, but not in 2000. Based on 2-yr assessments of seed infection by Mycosphaerella pinodes, chlorothalonil reduced seed infection by 19.2%, which was significant in 1999, but not in 2000. Chlorothalonil treatments provide a greater benefit in years when disease pressure and yield potential are high. Key words: Field pea, Pisum sativum, mycosphaerella blight, Mycosphaerella pinodes, chlorothalonil

* BACKGROUND AND OBJECTIVE: For laserinduced chorioretinal venous anastomosis to become a viable treatment option for perfused central retinal vein occlusion, laser parameters must be refined to more reliably create venous anastomoses while minimizing complications. The aim of this study was to determine the lowest argon laser power at which Bruch's membrane and the retinal vein are ruptured in 100% of attempts in the porcine eye. * MATERIALS AND METHODS: Testing was performed on 6 eyes of 3 Yorkshire Cross pigs, using an argon green laser. The spot size was 50 urn and the duration was 0.2 seconds for all applications. Twelve laser powers were tested, from 0.5 to 6 W, increasing by increments of 0.5 W. Light microscopy was used to determine the frequency of rupture of Bruch's membrane and the retinal vein for each power. * RESULTS: The rupture rate of Bruch's membrane was 0% at 0.5 W, 5% at 1.0 W, 20% at 1.5 W, 70% at 2.0 W, and 100% for all powers from 2.5 to 6.0 W. The rupture rate of the retinal vein was 0% at 0.5 W, 5% at 1.0 W, 30% at 1.5 W, 60% at 2.0 W, 80% at 2.5 W, and 100% for all powers from 3.0 to 6.0W. * CONCLUSION: Argon green laser powers of at least 2.5 and 3.0 W were necessary to rupture Bruch's membrane and the retinal vein, respectively, with a 100% success rate in the porcine eye. Because patients with central retinal vein occlusion have secondary retinal edema and may have lenticular opacity, higher laser powers may be required to achieve a 100% rupture rate of these structures. [Ophthalmic Surg Lasers Imaging 2003;34:122-127.]

[reaction: see text] The first direct reductive amination of mucochloric acid (1) has been accomplished. Reaction of 1 with various alkyl, aryl, and benzylamines, followed by reduction in the same pot, provides an efficient method of obtaining N-benzyl-3,4-dichloro-1,5-dihydro-pyrrol-2-one and N-aryl (or alkyl)-3,4-dichloro-1,5-dihydro-pyrrol-2-ones.

Two related phosphonium aryloxides, [Ph3PCH3]+2[CH2(C6H2-3,5-tert-butyl-4-O)2]2-, 1a, and [Ph3PC2H5]+2[CH2(C6H2-3,5-tert-butyl-4-O)2]2-, 1b have been synthesized by protonation of nonstabilized phosphorus ylides with 4,4‘-methylenebis(2,6-di-tert-butylphenol) LH2. The crystal structures of 1a and 1b have been determined by single-crystal X-ray diffraction, and that of 1b has also been determined by low-temperature (20 K) neutron diffraction. Both crystallize as CH3CN solvates, and both exhibit polymeric supramolecular structures via extensive C−H···O hydrogen bonding. The predominant structural motif is chelation of the aryloxide oxygen atom of the anion by phosphonium alkyl and aryl C−H groups, such as has been previously observed for phosphonium monoaryloxide salts. The use of this motif as a supramolecular synthon in crystal engineering is explored. In the case of 1a, in addition to the expected intermolecular C−H···O hydrogen bonding pattern, C−H···π interactions between the anion and this solvent are...

Poly(mandelic acid) (PMA) is an aryl analogue of poly(lactic acid) (PLA) and a biodegradable analogue of polystyrene. The preparation of stereoregular PMA was realized using a pyridine/mandelic acid adduct (Py⋅MA) as an organocatalyst for the ring-opening polymerization (ROP) of the cyclic O-carboxyanhydride (manOCA). Polymers with a narrow polydispersity index and excellent molecular-weight control were prepared at ambient temperature. These highly isotactic chiral polymers exhibit an enhancement of the glass-transition temperature (T(g)) of 15 °C compared to the racemic polymer, suggesting potential future application as high-performance commodity and biomedical materials.