Switching of magnetic properties by topotactic reaction in a 1D CN-bridged Ni(II)-Nb(IV) system.

Two 1D CN-bridged assemblies: the nearly straight Li2[Ni(cyclam)][Nb(CN)8]·7.5H2O (1) chains and the zigzag-shaped Li2[Ni(cyclam)][Nb(CN)8]·2H2O (2) chains, are obtained in the reaction between [Ni(cyclam)]2+ and [Nb(CN)8]4- in warm concentrated LiCl water solution. Both compounds are composed of alternating bimetallic Ni(II)-Nb(IV) chains and contain incorporated lithium cations, which compensate the negative charge of the coordination skeleton. The straight chain 1 (Ni-Nb-Ni angle = 153.2°) can be reversibly dehydrated under dry nitrogen flow at room temperature to an intermediate dihydrate phase 1d and further transformed to the zigzag-shaped chain 2 (Ni-Nb-Ni angle = 86.6°) by annealing at 150 °C. The process can be reversed by exposure to high humidity at room temperature, upon which 2 is converted back to 1. This water sorption-induced breathing effect is accompanied by changes in magnetic properties, most notably reflected in different values of saturation magnetization and critical field of metamagnetic transition, which indicate that both intra- and inter-chain interactions are affected by the structure reorganization.

The characterization of collagen-based scaffolds modified with phenolic acids for tissue engineering application.

The aim of the experiment was to study the morphology of collagen-based scaffolds modified by caffeic acid, ferulic acid, and gallic acid, their swelling, and degradation rate, as well as the biological properties of scaffolds, such as antioxidant activity, hemo- and cytocompatibility, histological observation, and antibacterial properties. Scaffolds based on collagen with phenolic acid showed higher swelling rate and enzymatic stability compared to scaffolds based on pure collagen, and the radical scavenging activity was in the range 85-91%. All scaffolds were non-hemolytic and compatible with surrounding tissues. Collagen modified by ferulic acid showed potentially negative effects on hFOB cells as a significantly increased LDH release was found, but all of the studied materials had antimicrobial activity against Staphylococcus aureus and Escherichia coli. It may be assumed that phenolic acids, such as caffeic, ferulic, and gallic acid, are modifiers and provide novel biological properties of collagen-based scaffolds. This paper provides the summarization and comparison of the biological properties of scaffolds based on collagen modified with three different phenolic acids.

Molecular Microbiological Characteristics of Gingival Pockets in the Periodontal Diseases of Dogs.

Introduction: Canine periodontitis results among other factors from a disturbed balance of dental plaque microflora and an inadequate host inflammatory response to a stimulus. This investigation sought to identify microorganisms associated with canine periodontitis. Material and Methods: Microbiological analysis was undertaken of gingival pockets in an experimental group of 36 dogs with periodontal diseases. Swabs were collected with the use of Pet Test (MIP Pharma, Berlin, Germany) from patients with gingival pockets deeper than 5 mm. Samples were aggregated and placed in separate shipping containers with the Pet Test kit. Results: Identification was made of the most common microorganisms, e.g. Porphyromonas gingivalis, Treponema denticola and Prevotella intermedia. The red complex constituted the largest proportion of all analysed organisms (84.26%). Capnocytophaga gingivalis was isolated from 33 dogs, Peptostreptococcus micros from 32 dogs, Fusobacterium nucleatum from 29 animals and P. intermedia from 20. Conclusion: The highest percentage of pathogens was supplied by P. gingivalis (61%). It is thought that dogs acquire them by means of cross-species transmission. The inter-study variability of results may depend not only on the method of periopathogen detection, but also on environmental factors, host immune status or genetic background. Depending on the state of periodontal disease, patients show varied microbiological profiles of the gingival pockets.

Chitosan/Phenolic Compounds Scaffolds for Connective Tissue Regeneration.

Chitosan-based scaffolds modified by gallic acid, ferulic acid, and tannic acid were fabricated. The aim of the experiment was to compare the compatibility of scaffolds based on chitosan with gallic acid, ferulic acid, or tannic acid using the in vivo method. For this purpose, materials were implanted into rabbits in the middle of the latissimus dorsi muscle length. A scaffold based on unmodified chitosan was implanted by the same method as a control. Moreover, the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) spectra and scanning electron microscope (SEM) observations were made to study the interactions between chitosan and phenolic acids. Additionally, antioxidant properties and blood compatibility were investigated. The results showed that all studied materials were safe and non-toxic. However, chitosan scaffolds modified by gallic acid and tannic acid were resorbed faster and, as a result, tissues were organized faster than those modified by ferulic acid or unmodified.

Concentrations of Selected Adipocytokines in the Blood Plasma in Proximal Suspensory Desmopathy of Horses, with a Focus on Their Physical Activity-A Pilot Study.

Chronic tendon and ligament diseases are commonly encountered in both athletic humans and animals, especially horses. Distal limb diseases, including suspensory ligament (SL) pathology due to anatomical, histological, and biomechanical properties, can be considered a model for tendon and ligament pathologies in humans. The appropriate selection of therapy is often crucial in optimising the healing process. One decisive factor influencing the possibility of returning to pre-disease training levels appears to be the utilisation of physical activity, including controlled movement, during the rehabilitation process. In the pathogenesis of musculoskeletal diseases and rehabilitation, adipocytokines play diverse roles. However, it is unclear what significance they hold in horses and in specific disease entities as well as the consequences of their mutual interactions. Recent studies indicate that in the pathogenesis of diseases with varied aetiologies in humans, their value varies at different stages, resulting in a diverse response to treatment. The results of this study demonstrate lower resistin concentrations in the venous blood plasma of horses with proximal suspensory desmopathy (PSD), while higher levels were observed in regularly trained and paddocked animals. The horses investigated in this study showed higher concentrations of resistin and IL-8, particularly in paddocked horses as well as in the working group of horses. The results suggest that these concentrations, including resistin in blood plasma, may be clinically significant. This attempt to explore the aetiopathogenesis of the processes occurring in the area of the proximal attachment of the suspensory ligament may optimise the procedures for the treatment and rehabilitation of horses.

Crystal Engineering and Photomagnetic Studies of CN-Bridged Coordination Polymers Based on Octacyanidometallates(IV) and [Ni(cyclam)]2.

A series of new CN-bridged coordination networks of different dimensionality and topology was obtained through the modification of reaction conditions between [Ni(cyclam)]2+ (cyclam = 1,4,8,11-tetraazacyclotetradecane) and [W(CN)8]4-. The factors determining the reaction pathway are temperature and addition of the LiCl electrolyte. The products include three negatively charged frameworks incorporating Li+ guests: the 1D Li2[Ni(cyclam)][W(CN)8]·6H2O (1) straight chain, the 1D Li2[Ni(cyclam)][W(CN)8]·2H2O (2) zigzag chain, and the 2D Li2[Ni(cyclam)]3[W(CN)8]2·24H2O (3) honeycomb-like network, as well as the 3D two-fold interpenetrating [Ni(cyclam)]5[Ni(CN)4][W(CN)8]2·11H2O (4) network and the 1D [Ni(cyclam)][Ni(CN)4]·2H2O (5) chain, which result from partial decomposition of the starting complexes. Together with the previously characterized 3D [Ni(cyclam)]2[W(CN)8]·16H2O (6) network, they constitute the largest family of CN-bridged coordination polymers obtained from the same pair of building blocks. All compounds exhibit paramagnetic behavior because of the separation of paramagnetic nickel(II) centers through the diamagnetic polycyanidometallates. However, the presence of the photomagnetically active octacyanidotungstate(IV) ions allowed observation of the magnetic superexchange after the violet light excitation (405 nm) for compound 3, which constitutes the first example of the photomagnetic effect in a NiII-[WIV(CN)8] system. The photomagnetic investigations for fully hydrated and dehydrated sample of 3, as well as for the isostructural octacyanidomolybdate(IV)-based network are discussed.

Hepta-coordinated Ni(II) assemblies - structure and magnetic studies.

Two mononuclear complexes [Ni(dapsc)(H2O)2]Cl(NO3)·H2O (1) and [Ni(dapsc)(NCS)2] (2), and a bimetallic CN-bridged trinuclear molecule [NiII(dapsc)(H2O)]2[WIV(CN)8]·11H2O (3) (dapsc = 2,6-diacetylpyridine-bis(semicarbazone)) were synthesised and characterised in terms of structure and magnetic properties. All three compounds contain Ni(ii) ions in a pentagonal bipyramid coordination geometry afforded by the equatorial pentadentate ligand (dapsc) and two O- or N-donating axial ligands. The compounds differ in the relative arrangement of the complexes, intermolecular interactions and distortion from the ideal coordination geometry. The high-field EPR and magnetometric studies show large anisotropy of the Ni(ii) centres with the D parameters in the range of -10.5 to -21.2 cm-1 and negligible antiferromagnetic interactions. The easy-axis magnetic anisotropies of 1-3 were reproduced by ab initio CASSCF/NEVPT2 calculations. The ground states consist mainly of the |MS = |±1 states, which is consistent with the fact that no out-of-phase signal can be detected in the AC magnetic susceptibility measurements.

Tuning of magnetic properties of the 2D CN-bridged NiII-NbIV framework by incorporation of guest cations of alkali and alkaline earth metals.

The reaction between [Ni(cyclam)]2+ (cyclam = 1,4,8,11-tetraazacyclotetradecane) and [Nb(CN)8]4- in concentrated water solutions of different s-block metal salts leads to the formation of 2-dimensional honeycomb-like coordination networks of the formula Mx[Ni(cyclam)]3[Nb(CN)8]2·nH2O (x = 2: M = Li+, Na+; x = 1: M = Mg2+, Ca2+, Sr2+, Ba2+). The CN-bridged Ni-Nb coordination layers are intersected by channels filled with crystallisation water molecules and guest mono- or di-valent metal cations, which compensate the negative charge of the framework. The structural details and crystal symmetry vary between the networks, depending on the arrangement of the water molecules and the intermolecular interactions enforced by the guest cations. All compounds show long range magnetic order arising from superexchange interactions between paramagnetic NiII (s = 1) and NbIV (s = 1/2) centres through CN-bridges within the layers and weaker inter-layer interactions mediated by H-bonds. The ordering temperature as well as the coercive field of the magnetic hysteresis can be tuned by the type of guest cation, with the highest values achieved for Mg2+ and the lowest for Na+.

Unusual Penile Prolapse with an Infectious Background Caused by the Burkholderia cepacia Complex in a Stallion.

Penile prolapse is a disease manifested by an inability to retract the penis into the preputial sheath. It is reported in a variety of animal species, especially in young and intact males. However, penile prolapse in horses is commonly caused by trauma, sexual activity, pseudohermaphroditism, or neurological deficits, and less often by an infectious background. The present case report aimed to determine the etiological factor of penis infection associated with penile prolapse in a stallion in Poland. Our report indicates that the infectious background of penile prolapse was related to the Burkholderia cepacia complex. Based on antibiotic susceptibility results, the stallion was administered effective streptomycin and enrofloxacin treatment and recovered without complications. The following options are likely to be the infection source: contamination of hay or animal hygiene products. Finally, given its ability to grow in antiseptic solutions, difficulties in culturing, and innate multidrug resistance, this microorganism is currently a challenge to both detection and treatment in veterinary medicine cases.

Room-Temperature Bistability in a Ni-Fe Chain: Electron Transfer Controlled by Temperature, Pressure, Light, and Humidity.

Bistable and stimuli-responsive molecule-based materials are promising candidates for the development of molecular switches and sensors for future technologies. The CN-bridged {NH4 [Ni(cyclam)][Fe(CN)6 ]⋅5 H2 O}n chain exists in two valence states: NiII -FeIII (1HT ) and NiIII -FeII (1LT ) and shows unique multiresponsivity under ambient conditions to various stimuli, including temperature, pressure, light, and humidity, which generate measurable response in the form of significant changes in magnetic susceptibility and color. The electron-transfer phase transition 1LT ↔1HT shows room-temperature thermal hysteresis, can be induced by irradiation, and shows high sensitivity to small applied pressure, which shifts it to higher temperatures. Additionally, it can be reversibly turned off by dehydration to the {NH4 [NiII (cyclam)][FeIII (CN)6 ]}n (1 d) phase, which features the NiII -FeIII valence state over the whole temperature range, but responds to pressure by yielding NiIII -FeII above 1.06 GPa.

Octacyanidometallates for multifunctional molecule-based materials.

Octacyanidometallates have been successfully employed in the design of heterometallic coordination systems offering a spectacular range of desired physical properties with great potential for technological applications. The [M(CN)8]n- ions comprise a series of complexes of heavy transition metals in high oxidation states, including NbIV, MoIV/V, WIV/V, and ReV. Since the discovery of the pioneering bimetallic {MnII4[MIV(CN)8]2} and {MnII9[MV(CN)8]6} (M = Mo, W) molecules in 2000, octacyanidometallates were fruitfully explored as precursors for the construction of diverse d-d or d-f coordination clusters and frameworks which could be obtained in the crystalline form under mild synthetic conditions. The primary interest in [M(CN)8]n--based networks was focused on their application as molecule-based magnets exhibiting long-range magnetic ordering resulting from the efficient intermetallic exchange coupling mediated by cyanido bridges. However, in the last few years, octacyanidometallate-based materials proved to offer varied and remarkable functionalities, becoming efficient building blocks for the construction of molecular nanomagnets, magnetic coolers, spin transition materials, photomagnets, solvato-magnetic materials, including molecular magnetic sponges, luminescent magnets, chiral magnets and photomagnets, SHG-active magnetic materials, pyro- and ferroelectrics, ionic conductors as well as electrochemical containers. Some of these materials can be processed into the nanoscale opening the route towards the development of magnetic, optical and electronic devices. In this review, we summarise all important achievements in the field of octacyanidometallate-based functional materials, with the particular attention to the most recent advances, and present a thorough discussion on non-trivial structural and electronic features of [M(CN)8]n- ions, which are purposefully explored to introduce desired physical properties and their combinations towards advanced multifunctional materials.

Relationship Between Neutrophil Activity, Oxidative Stress, Acute Phase Response, and Lameness Grade in Naturally Occurring Acute and Chronic Joint Disorders in Horses.

We hypothesized that in horses with naturally occurring joint disorders, the neutrophil response, acute phase response (APR), and oxidative stress parameters elevated significantly and are markers of increased inflammatory response in these conditions. Therefore, the first aim of the study was to evaluate neutrophil response, oxidative status, and APR. The neutrophil activity was assessed on the basis of elastase, myeloperoxidase (MPO), and alkaline phosphatase release, whereas free radical generation was assessed on the basis of nitric oxide and superoxide production. Acute phase response was estimated on the basis of fibrinogen or haptoglobin plasma concentration and oxidative stress on the basis of malondialdehyde plasma concentration. Then, these parameters were compared with lameness grade, and correlation coefficients between them were calculated. The study was conducted on 43 horses divided on control group of healthy horses (n = 17), acute lameness (AL) group (11 horses), and chronic lameness (CL) group (15 horses). The neutrophil activity from horses of both groups of joint disorders (AL and CL) was significantly (P < .01) higher in comparison with healthy horses. Elastase release was 67.28 ± 1.89% of maximal activity in AL group in comparison with 51.72 ± 1.75% in healthy horses and 62.61 ± 1.54% in CL group. The highest values of other enzymes were also noted in AL group. Moreover, in AL group release of elastase and MPO positively correlated (P < .01) with grades of lameness. These findings revealed the mutual relation between studied parameters and obtained results may be useful in the development of new therapeutic strategies in the treatment of acute and chronic joint disorders in horses.

Proton-Conducting Humidity-Sensitive NiII-NbIV Magnetic Coordination Network.

The 2D coordination network (NH4)2[NiII(cyclam)]3[NbIV(CN)8]2·21H2O (1·21H2O) was obtained on a cation-assisted synthetic pathway. The reaction between [Ni(cyclam)]2+ and [Nb(CN)8]4- in the presence of excess of NH4Cl resulted in the formation of negatively charged coordination layers with the simultaneous incorporation of the NH4+ cations into the microporous channels of the structure. 1·21H2O network can be partly dehydrated in a single-crystal-to-single-crystal structural transformation to give (NH4)2[NiII(cyclam)]3[NbIV(CN)8]2·14H2O (1·14H2O). The dehydration-induced structural changes, in particular the deformation of CN--bridges and the disruption of interlayer interactions, give rise to the solvatomagnetic effect. Fully hydrated 1·21H2O phase is a ferrimagnet with a critical temperature of magnetic ordering of 7.6 K and a narrow magnetization hysteresis loop, while 1·14H2O hydrate is an antiferromagnet with Tc = 7.2 K and metamagnetic transition at 6.3 kOe. Thanks to the presence of the NH4+ ions in the structure, the proton conductivity of ∼4 × 10-5 S cm-1 (295 K, 100% relative humidity, RH) is observed with the activation energy of 0.80 eV.

The Use of Allogenic Stromal Vascular Fraction (SVF) Cells in Degenerative Joint Disease of the Spine in Dogs.

BACKGROUND/AIM: Stem cells are widely used in regenerative medicine and in clinical practice for the treatment of damaged nerve tissue, myocytes, tendons, and ligaments. The aim of the study was to monitor VEGF levels after the administration of allogenic cellular material (SVF) in the course of treatment of dogs suffering from degenerative joint disease in the spinal region. MATERIALS AND METHODS: The study was conducted on 10 dogs of both genders, aged between 6 and 13 years in which allogenic stromal vascular fraction of stem cells (SVF) was administered intravenously. The control group was composed of 10 clinically healthy dogs. Before treatment and after 2- and 8-week intervals blood samples were obtained from the study group dogs in order to determine VEGF levels via immunoenzymatic test. RESULTS: in a few days after the therapy, alleviation of pain symptoms and reduction of lameness were noticed. The VEGF level in 2 weeks after the therapy was significantly elevated (median: 38.77 pg/ml), while in 8 weeks a decrease was observed (median: 18.37 pg/ml). Conlusion: Administration of allogenic stem cells has a positive influence on elevation of the VEGF levels in the blood serum of affected animals as well as their regeneration capacity.

Dehydration-Triggered Charge Transfer and High Proton Conductivity in (H3O)[NiIII(cyclam)][MII(CN)6] (M = Ru, Os) Cyanide-Bridged Chains.

The coexistence of dehydration-driven charge transfer, magnetic interactions, and high proton conductivity was found in two bimetallic alternating CN-bridged chains {(H3O)[NiIII(cyclam)][MII(CN)6]·5H2O} n (M = Ru (1), Os (2); cyclam = 1,4,8,11-tetraazacyclotetradecane). Dehydration of these materials causes structural transformation and triggers charge transfer between the metal centers: NiIII-NC-MII → NiII-NC-MIII. The CT process, whose extent is tuned by the change of the anionic building block, causes significant increase of magnetic moment, appearance of antiferromagnetic interactions, and noticeable changes in color. The high conductivity values of σ = 1.09 × 10-3 (1) and 1.12 × 10-3 S cm-1 (2) at 295 K and 100% relative humidity allow the classification of the materials as superionic conductors. The proton conduction occurs according to the Grotthuss mechanism as a hopping of protons between H-bonded water molecules due to the presence of the H3O+ ions, which compensate negative charge of the coordination chains.

Dehydration of Octacyanido-Bridged NiII-WIV Framework toward Negative Thermal Expansion and Magneto-Colorimetric Switching.

An inorganic three-dimensional [NiII(H2O)2]2[WIV(CN)8]·4H2O (1) framework undergoes a single-crystal-to-single-crystal transformation upon thermal dehydration, producing a fully anhydrous phase NiII2[WIV(CN)8] (1d). The dehydration process induces changes in optical, magnetic, and thermal expansion properties. While 1 reveals typical positive thermal expansion of the crystal lattice, greenish-yellow color, and paramagnetic behavior, 1d is the first ever reported octacyanido-based solid revealing negative thermal expansion, also exhibiting a deep red color and diamagnetism. Such drastic shift in the physical properties is explained by the removal of water molecules, leaving the exclusively cyanido-bridged bimetallic network, which is accompanied by the transformation of the octahedral paramagnetic [NiII(H2O)2(NC)4]2- to the square-planar diamagnetic [NiII(NC)4]2- moieties.

Ligand dependent topology and spontaneous resolution in high-spin cyano-bridged Ni3W2 clusters.

Two high-spin pentanuclear NiW clusters with diimine blocking ligands have been obtained: {[Ni(4,4'-MeObpy)2]3[W(CN)8]2}·12H2O (1) and {[Ni(phen)2(H2O)][Ni(phen)2]2[W(CN)8]2}·7H2O (2) (4,4'-MeObpy = 4,4'-dimethoxy-2,2'-bipyridine, phen = 1,10-phenanthroline). Despite the similarity of the building blocks and synthetic conditions the compounds show different topologies of the cluster core: 1 is a trigonal bipyramid while 2 is a decorated square. Both cluster structures are chiral with either ΔΔΔ or ΛΛΛ configuration around all three Ni centres. In 1 spontaneous resolution occurs and it crystallises in the P212121 space group forming a conglomerate containing both types of enantiomorphic crystals. 1Δ and 1Λ are the first pair of enantiomorphic structures of cyano-bridged clusters of trigonal bipyramidal topology obtained with achiral bidentate blocking ligands. 2 crystallises as a racemic compound in a centrosymmetric space group P1[combining macron] with both enantiomers present in the structure. 2 is an exceptional square-motif containing structure with an identical stereoconfiguration of all complex cations within one cluster. Ferromagnetic interactions are present in both clusters resulting in the ground spin state S = 4.

Hydration-switchable charge transfer in the first bimetallic assembly based on the [Ni(cyclam)](3+)--magnetic CN-bridged chain {(H3O)[Ni(III)(cyclam)][Fe(II)(CN)6]·5H2O}n.

An alternating bimetallic {(H3O)[Ni(III)(cyclam)][Fe(II)(CN)6]·5H2O}n chain undergoes reversible dehydration at 40 °C accompanied by electron transfer which leads to Ni(II)-Fe(III) in about 50% of metal centres. The hydrated dark blue form is a paramagnet while the dehydrated yellowish-green form shows ferromagnetic coupling between neighbouring Ni(II) and Fe(III).

New topology of CN-bridged clusters: dodecanuclear face-sharing defective cubes based on octacyanometallates(iv) and nickel(ii) with diimine ligands.

New dodecanuclear bimetallic Ni8M4 clusters were obtained in the reaction between octacyanometallates(IV), nickel(II) cations and diimine ligands. {[Ni(LL)(H2O)]2[Ni(LL)(H2O)2]6[M(CN)8]4} assemblies, where LL = 1,10-phenanthroline M = Mo, (1) or LL = 2,2'-bipyridine M = W (2) or Mo (3), are among the largest octacyanometallate-based clusters. They show the same compact topology of the cluster core, which can be described as defective face-sharing cubes with corners defined by alternating metal centres. The structures are stabilised by π­π interactions between aromatic rings of diimine ligands and hydrogen bonds connecting terminal CN groups and coordinated H2O molecules through a crystallisation solvent. Different decorating ligands cause different arrangements of clusters in the crystal structure. 1 crystallises in the triclinic system space group P, while 2 and 3 crystallise in the monoclinic system space group P21/n. The clusters show paramagnetic behaviour with weak antiferromagnetic interactions between the NiII centres through diamagnetic NC-MIV-CN linkages.

A water sensitive ferromagnetic [Ni(cyclam)]2[Nb(CN)8] network.

Reaction between [Ni(cyclam)](2+) and [W(CN)(8)](4-) leads to the formation of a 3D diamond-like network [Ni(cyclam)](2)[W(CN)(8)]·3.5H(2)O (1). The structure is characterised by a network of intersecting channels of 3-4 Å in diameter, filled with crystallisation water, most of which is released upon drying in air, causing the crystals to collapse. Analogous compound [Ni(cyclam)](2)[Nb(CN)(8)]·3.5H(2)O (2), based on paramagnetic Nb(IV), could only be obtained as a powder, due to the decomposition of the [Nb(CN)(8)](4-) complex under slow diffusion conditions. It shows long-range magnetic ordering with T(C) = 11.8 K and magnetic hysteresis at 2 K. These properties are lost upon drying in air. After rehydration differently shaped hysteresis appears, which together with AC susceptibility measurements suggests the formation of a multiphase system. Subsequent dehydration-rehydration experiments show partial reversibility.