Tunable Approach to Induce the Formation of Flexible Nanofilms from Small (3 nm) Gold Nanoparticles at Oil-Water Interfaces.

The self-assembly of gold nanoparticles (AuNPs) into thin films at the liquid-liquid interface has promising applications in industries such as catalysis, optics, and sensors. However, precise control over their formation is complex, influenced by several factors which scale differently with core size. Due to their small free energy of adsorption, there are few examples of AuNPs with core diameters <10 nm. The present research evaluates the adsorption of ∼3 nm AuNPs from either side of the oil-aqueous interface with variations in ligand shell composition, the oil phase composition, and the structure of alcohol additives to best drive thin-film formation. Film formation and quality are evaluated, and a recent thermodynamic model is used to gain insight into the primary forces promoting this adsorption. Results demonstrate that longer-chain alcohol additives (namely, n-butanol and n-hexanol) induced adsorption more efficiently than shorter-chain alcohols (ethanol). The volume of alcohol additive needed to induce adsorption was dependent upon the ligand composition, suggesting that the mechanism for induced interfacial adsorption is via interaction with the AuNP ligand shell. Comparison with the thermodynamic model indicates that the driving force for this induced adsorption is the alteration of the three-phase contact angle. Additionally, the use of various oils demonstrates that as oil-water interfacial tension increases, more AuNPs adsorb to the interface. This relationship is also supported by the model. Insight gained for favorable conditions of adsorption for AuNPs < 10 nm as well as the underlying thermodynamic mechanism is important in working toward the ability to fine-tune such films for industrial applications.

Multiparametric cytotoxicity assessment: the effect of gold nanoparticle ligand functionalization on SKOV3 ovarian carcinoma cell death.

Gold nanoparticles (AuNP) are promising anti-cancer agents because of their modifiable properties and high biocompatibility. This study used multiple parallel analyses to investigate the cytotoxic properties of 5 nm AuNP conjugated to four different ligands with distinct surface chemistry: polyethylene glycol (PEG), trimethylammonium bromide (TMAB), 4-dimethylaminopyridine (DMAP), and carboxyl (COOH). We used a range of biochemical and high-content microscopy methods to evaluate the metabolic function, oxidative stress, cell health, cell viability, and cell morphology in SKOV3 ovarian cancer cells. Each AuNP displayed a distinct cytotoxicity profile. All AuNP species assessed exhibited signs of dose-dependent cytotoxicity when morphology, clonogenic survival, lysosomal uptake, or cell number were measured as the marker of toxicity. All particles except for AuNP-COOH increased SKOV3 apoptosis. In contrast, AuNP-TMAB was the only particle that did not alter the metabolic function or induce significant signs of oxidative stress. These results demonstrate that AuNP surface chemistry impacts the magnitude and mechanism of SKOV3 cell death. Together, these findings reinforce the important role for multiparametric cytotoxicity characterization when considering the utility of novel particles and surface chemistries.

Examination of Oil Structural Motifs and Temperature in Promoting Reversible Self-Assembly of Gold Nanoparticle Langmuir Films.

The interaction between gold nanoparticles (AuNPs) with other components and phases has important consequences on their use in materials and devices as well as their fate in the environment or at biological interfaces. Previously we determined that long oil chain lengths and lower temperatures optimized the mixing of n-alkanes with alkanethiol-capped AuNPs which improved nanoparticle self-assembly into superlattices at aqueous interfaces. In this study, a variety of liquid phase hydrocarbon oils with structural and functional variations were surveyed for their mixing efficacy and propensity to enable reversible self-assembly of nanoparticle domains. Transmission electron microscopy (TEM) images and pressure vs area isotherms across this series reveal isotherm features that distinguish between the mixing and inclusion of the oil at the interface and that which enables reversible self-assembly. Structural and functional characteristics of the oil for promoting reversible self-assembly are identified which surpass the importance of chain length previously described. Temperatures below the ligand order-disorder transition were found to improve the reversibility of AuNP domains and are understood by application of a reparametrized x-DLVO model.

[SARS-CoV-2 infections in cats, dogs, and other animal species: Findings on infection and data from Switzerland]. / SARS-CoV-2 Infektionen bei Katzen, Hunden und anderen Tieren: Erkenntnisse zur Infektion und Daten aus der Schweiz.

INTRODUCTION: The pandemic with the novel coronavirus (SARS-CoV-2) has led to infections and deaths worldwide. Apart from humans, certain animal species are susceptible to the viral infection. Spillover between humans and animals is favored by close contact; thus, surveillance of animals is an important component to fight the pandemic from a One Health perspective. The Clinical Laboratory of the Vetsuisse Faculty Zurich has been investigating SARS-CoV-2 infections in animals since the beginning of the pandemic. In November 2020, the first SARS-CoV-2 positive Swiss cat was reported to the World Organisation for Animal Health (OIE-WAHIS). The cat showed respiratory signs and lived in a COVID-19 affected household. By now, over 500 natural SARS-CoV-2 infections have been recorded in animals worldwide. A prevalence study on SARS-CoV-2 infections in dogs and cats was carried out together with clinics from Germany and Italy during the first wave of the pandemic (March-July 2020). Among the tested 1137 animals, only one cat and one dog were positive. The prevalence of infection in dogs and cats presented to veterinary clinics was low, even in pandemic hotspot regions. However, recent studies that focused on animals in COVID-19 households found a higher prevalence of infection. A study is currently underway that specifically collects samples from pets from Swiss COVID-19 affected household and collects data on human-animal interaction.

INTRODUCTION: La pandémie à nouveau coronavirus (SARS-CoV-2) a entraîné des infections et des décès dans le monde entier. En dehors de l'homme, certaines espèces animales sont sensibles à cette infection virale. Le passage entre les humains et les animaux est favorisé par un contact étroit, la surveillance des animaux est donc un élément important pour lutter contre la pandémie dans une perspective One Health. Depuis le début de la pandémie, le laboratoire clinique de la faculté Vetsuisse de Zurich étudie les infections par le SRAS-CoV-2 chez les animaux. En novembre 2020, le premier chat suisse positif au SARS-CoV-2 a été signalé à l'Organisation mondiale de la santé animale (OIE-WAHIS). Le chat a montré des signes respiratoires et vivait dans un ménage touché par le COVID-19. À l'heure actuelle, plus de 500 infections naturelles au SRAS-CoV-2 ont été enregistrées chez des animaux dans le monde. Une étude de prévalence sur les infections par le SRAS-CoV-2 chez les chiens et les chats a été réalisée avec des cliniques d'Allemagne et d'Italie pendant la première vague de la pandémie (mars-juillet 2020). Parmi les 1137 animaux testés, seuls un chat et un chien étaient positifs. La prévalence de l'infection chez les chiens et les chats présentés aux cliniques vétérinaires était faible, même dans les régions fortement touchées par la pandémie. Cependant des études récentes, qui se sont concentrées sur les animaux dans les ménages COVID-19, ont révélé une prévalence d'infection plus élevée. Une étude est actuellement en cours qui collecte spécifiquement des échantillons d'animaux de compagnie des ménages suisses touchés par le COVID-19 et enregistre des données sur l'interaction homme-animal.

Emergency department reorganisation to cope with COVID-19 outbreak in Milan university hospital: a time-sensitive challenge.

BACKGROUND: In March 2020 we faced a huge spread of the epidemic of SARS-CoV2 in northern Italy; the Emergency Departments (ED) and the Emergency Medical Services (EMS) were overwhelmed by patients requiring care. The hospitals were forced to reorganize their services, and the ED was the focal point of this challenge. As Emergency Department in a metropolitan area of the region most affected, we saw an increasing number of patients with COVID-19, and we made some structural and staff implementations according to the evolution of the epidemic. METHODS: We analysed in a narrative way the weaknesses and the point of strength of our response to COVID-19 first outbreak, focusing point by point on main challenges and minor details involved in our ED response to the pandemics. RESULTS: The main stems for our response to the pandemic were: use of clear and shared contingency plans, as long as preparedness to implement them; stockage of as much as useful material can be stocked; training of the personnel to be prepared for a fast response, trying to maintain divided pathway for COVID-19 and non-COVID-19 patients, well-done isolation is a key factor; preparedness to de-escalate as soon as needed. CONCLUSIONS: We evaluated our experience and analysed the weakness and strength of our first response to share it with the rest of the scientific community and colleagues worldwide, hoping to facilitate others who will face the same challenge or similar challenges in the future. Shared experience is the best way to learn and to avoid making the same mistakes.

Commentary: Revisiting nanoparticle-assay interference: There's plenty of room at the bottom for misinterpretation.

Engineered nanomaterials (ENMs) are a diverse class of materials whose distinct properties make them desirable in a multitude of applications. The proliferation of nanotoxicology research has improved our understanding of ENM toxicity, but an under appreciation for their potential to interfere with biochemical assays has hampered progress in the field. The physicochemical properties of ENMs can promote their interaction with membranes or biomacromolecules (e.g. proteins, genomic material). This can influence the activity of enzymes used as biomarkers or as reagents in biochemical assay protocols, bind indicator dyes in cytotoxicity tests, and/or interfere with the cellular mechanisms controlling the uptake of such dyes. The spectral characteristics of some ENMs can cause interference with common assay chromophores, fluorophores, and radioisotope scintillation cocktails. Finally, the inherent chemical reactivity of some ENMs can short circuit assay mechanisms by directly oxidizing or reducing indicator dyes. These processes affect data quality and may lead to significant misinterpretations regarding ENM safety. We provide an overview of some ENM properties that facilitate assay interference, examples of interference and the erroneous conclusions that may result from it, and a number of general and specific recommendations for validating cellular and biochemical assay protocols in nanotoxicology studies.

Tuning the magnetism of gold nanoparticles by changing the thiol coating.

Room-temperature ferromagnetic behaviour has been reported in nanoscale materials expected to be diamagnetic, including gold. However, it is yet unclear which factors (size, shape, surface coating) predominantly influence the magnitude of the magnetic response. In this work, we study the magnetic and electronic properties of similarly-sized gold nanoparticles (Au NPs) coated with four different n-alkanethiols, as well as hydroxyl- and carboxyl-functionalized alkanethiols using superconducting quantum interference device (SQUID) magnetometry and ultraviolet photoelectron spectroscopy (UPS). We find room-temperature behaviour (hysteresis in magnetization vs. field strength loops) in all samples, as well as large effective magnetic anisotropy. Importantly, we find the nanoparticles coated with polar chain end-groups (-OH and -COOH) show markedly higher magnetization; this increased magnetization correlates with a higher work function. This work establishes chemical handles to enhance magnetism in nanoscale gold particles.

Inflammatory Mediators in the Mesenteric Lymph Nodes, Site of a Possible Intermediate Phase in the Immune Response to Feline Coronavirus and the Pathogenesis of Feline Infectious Peritonitis?

Feline infectious peritonitis (FIP) is an almost invariably fatal feline coronavirus (FCoV)-induced disease thought to arise from a combination of viral mutations and an overexuberant immune response. Natural initial enteric FCoV infection may remain subclinical, or result in mild enteric signs or the development of FIP; cats may also carry the virus systemically with no adverse effect. This study screened mesenteric lymph nodes (MLNs), the presumed first site of FCoV spread from the intestine regardless of viraemia, for changes in the transcription of a panel of innate immune response mediators in response to systemic FCoV infection and with FIP, aiming to identify key pathways triggered by FCoV. Cats with and without FIP, the latter with and without FCoV infection in the MLN, were compared. Higher expression levels in FIP were found for toll-like receptors (TLRs) 2, 4 and 8. These are part of the first line of defence and suggest a response to both viral structural proteins and viral nucleic acid. Expression of genes encoding inflammatory cytokines and chemokines, including interleukin (IL)-1ß, IL-6, IL-15, tumour necrosis factor (TNF)-α, CXCL10, CCL8, interferon (IFN)-α, IFN-ß and IFN-γ, was higher in cats with FIP, consistent with inflammatory pathway activation. Expression of genes encoding transcription factors STAT1 and 2, regulating signalling pathways, particularly of the interferons, was also higher. Among cats without FIP, there were few differences between virus-positive and virus-negative MLNs; however, TLR9 and STAT2 expression were higher with infection, suggesting a direct viral effect. The study provides evidence for TLR involvement in the response to FCoV. This could open up new avenues for therapeutic approaches.

Molecular investigations of cat fleas (Ctenocephalides felis) provide the first evidence of Rickettsia felis in Malta and Candidatus Rickettsia senegalensis in Israel.

Rickettsia felis, the causative agent of flea-borne spotted fever, occurs on all continents except Antarctica, owing to the cosmopolitan distribution of its cat flea vector. In this study, cat fleas were collected in two countries where the occurrence of R. felis was either unknown (Malta) or where accurate prevalence data were lacking (Israel). Altogether 129 fleas were molecularly analysed for the presence of rickettsial DNA. On the basis of three genetic markers, R. felis was identified in 39.5% (15/38) of the cat fleas from Malta. Sequences showed 100% identity to each other and to relevant sequences in GenBank. Among the 91 cat fleas from Israel, two (2.2%) contained the DNA of Candidatus Rickettsia senegalensis. Phylogenetically, the R. felis and Candidatus R. senegalensis identified here clustered separately (with high support) but within one clade, which was a sister group to that formed by the typhus group and spotted fever group rickettsiae. This is the first record of R. felis in Malta and of Candidatus R. senegalensis outside its formerly reported geographical range including Africa, Asia and North America.

[Feline leukemia virus infection: importance and current situation in Switzerland]. / Die feline Leukämievirus-Infektion: Bedeutung und aktuelle Situation in der Schweiz.

INTRODUCTION: Feline leukemia virus (FeLV) leads to fatal disease in cats with progressive infection. The aim of this study was to determine the importance of FeLV infection in Switzerland and make a comparison with previous studies. Of 881 blood samples taken from cats living in Switzerland (minimum of 20 samples per Canton), 47 samples were provirus-positive (5.3%; 95% confidence interval (CI) 3.9-7.0%) and 18 samples were antigen-positive (2%; 95% CI 1.2-3.2%). Together with data previously collected in similar studies, these findings demonstrated a decrease in prevalence between 1997 and 2003 followed by a relative constant low prevalence thereafter. Young cats (=2 years) were more frequently infected than older cats, but FeLV-positive cats were up to 15 (antigen-positive) and 19 (provirus-positive) years old. Sexually intact cats were more frequently viremic than neutered cats; purebred cats were somewhat less frequently FeLV-positive than non-purebred cats. In a second study, in which 300 saliva samples were analyzed, samples from 5 cats were FeLV-RNA positive (1.7%; 95% CI, 0.5-3.8%), although one young feral cat had been falsely assumed to be FeLV-negative based on a point-of-care test. Of the 300 cats, only 50% were FeLV tested or vaccinated, although 90% of the cats were at risk of exposure to FeLV. Testing and vaccination of all cats with exposure risk may help further decrease the prevalence of FeLV infection. Moreover, characteristics of FeLV tests should be considered, such as the risk of false negative results in the early phase of infection when performing antigen testing.

INTRODUCTION: Le virus leucémogène félin (FeLV) conduit la plupart du temps à une maladie mortelle chez le chat avec une infection progressive. Le but du présent travail est de mettre en évidence l'importance de l'infection à FeLV en Suisse sur la base de recherches actuelles et de la comparer avec les résultats de recherches antérieures. Afin de répondre à la question de savoir combien de chats présentés à la consultation étaient porteurs du FeLV (positifs au provirus) respectivement excréteurs de FeLV (positifs à l'antigène), on a analysé 881 échantillons sanguins provenant de toute la Suisse (au minimum 20 par canton) : 47 échantillons étaient positifs au provirus (5.3%; 95% intervalle de confiance (CI) 3.9­7.0%) et 18 positifs à l'antigène (2%; 95% CI 1.2­3.2%). Une comparaison avec des recherches semblables faites antérieurement montre que la prévalence du FeLV a diminué entre 1997 et 2003 mais qu'elle stagne depuis lors. Actuellement ce sont plutôt les jeunes chats (=2 ans) qui sont touchés plutôt que les vieux; des chats ont toutefois été trouvés positifs jusqu'à l'âge de 15 ans (positifs à l'antigène) respectivement de 19 ans (positifs au provirus). Les chats non castrés étaient plus souvent virémiques que les castrés et les chats de races étaient aussi, mais un peu moins fréquemment FeLV-positifs. Dans une autre étude suisse, dans laquelle 300 échantillons de salive de chats ont été testés quant à la présence d'ARN-FeLV, 5 chats étaient excréteurs (1.7%; 95% CI 0.5­3.8%). Un jeune chat trouvé, qui avait été testé négatif au test rapide, a été trouvé infecté par le FeLV au moyen de la mise en évidence d'ARN. Sur ces 300 chats, seuls environ 50% avaient été testés quant au FeLV respectivement vaccinés, bien qu'environ 90% aient présenté un risque d'exposition au FeLV. Pour diminuer encore la prévalence du FeLV, il conviendrait de tester et de vacciner tous les chats avec un risque d'exposition au virus. Dans ce contexte, il faut tenir compte des différentes caractéristiques des tests comme la non reconnaissance de la phase d'infection très précoce au moyen du test FeLV rapide.

Elemental and radiological characterization of commercial Cetraria islandica (L.) Acharius pharmaceutical and food supplementation products.

An elemental and radiological characterization was performed on Cetraria islandica (L.) Ach. pharmaceutical and food supplementation products purchased in local specialty shops in Italy. Essential elements (K, Ca, P, S, Cl, Mn, Fe, Cu, Zn, Ni, Br, I) and nonessential or toxic elements (Al, Ti, Si, Rb, Sr, As, Cd, Sn, and Pb) were determined by Energy Dispersive Polarized X-Ray Fluorescence Spectrometry; natural radionuclides (238U, 234U, 230Th, 210Po, 232Th, and 228Th) were determined by alpha spectrometry. The results show that C. islandica, whose nutritional value was assessed referring to recommended nutrient intakes, could serve as an important source of essential elements. Moreover, as expected, lichens concentrate airborne 210Po, whose activity ranged from 132 to 489Bqkg-1dw. This value was much higher than those reported by UNSCEAR for leafy vegetables in the world. In addition, total As and Cd were <1mgkg-1dw and Pb mean concentration was 9.25mgkg-1dw. Health risks associated with the toxic elements contained in C. islandica (L.) products were calculated using risk estimators. Their contribution to total elemental intake does not appear to pose a threat, but the concentrations of these elements should be continuously monitored to protect consumers against potential adverse health effects.

The association between sleep quality, low back pain and disability: A prospective study in routine practice.

BACKGROUND: The objective of this study was to estimate the association between sleep quality (SQ) and improvements in low back pain (LBP) and disability, among patients treated for LBP in routine practice. METHODS: This prospective cohort study included 461 subacute and chronic LBP patients treated in 11 specialized centres, 14 primary care centres and eight physical therapy practices across 12 Spanish regions. LBP, leg pain, disability, catastrophizing, depression and SQ were assessed through validated questionnaires upon recruitment and 3 months later. Logistic regression models were developed to assess: (1) the association between the baseline score for SQ and improvements in LBP and disability at 3 months, and (2) the association between improvement in SQ and improvements in LBP and disability during the follow-up period. RESULTS: Seventy-three per cent of patients were subacute. Median scores at baseline were four points for both pain and disability, as assessed with a visual analog scale and the Roland-Morris Questionnaire, respectively. Regression models showed (OR [95% CI]) that baseline SQ was not associated with improvements in LBP (0.99 [0.94; 1.06]) or in disability (0.99 [0.93; 1.05]), although associations existed between 'improvement in SQ' and 'improvement in LBP' (4.34 [2.21; 8.51]), and 'improvement in SQ' and 'improvement in disability' (4.60 [2.29; 9.27]). CONCLUSIONS: Improvement in SQ is associated with improvements in LBP and in disability at 3-month follow-up, suggesting that they may reflect or be influenced by common factors. However, baseline SQ does not predict improvements in pain or disability. SIGNIFICANCE: In clinical practice, sleep quality, low back pain and disability are associated. However, sleep quality at baseline does not predict improvement in pain and disability.

Tunable Mechanical Properties of Nanoparticle Monolayer Membranes via Ligand Phase Control and Defect Distribution.

In this study, the effects of ligand phase, morphology, and temperature on the elastic modulus of free-standing alkanethiol-capped gold nanoparticle membranes are reported. Langmuir films of 2.5 nm gold nanoparticles capped with tetradecanethiol were prepared at temperatures above and below the phase transition temperature (T m) of the ligand shell and transferred to holey carbon grids (containing 1.2 µm holes) to form free-standing membranes. Force-indentation measurements are used to measure the elastic modulus of the membranes using an atomic force microscope in the temperature range 10-40 °C. These films are compared with membranes of dodecanethiol-capped gold nanoparticles, which do not undergo a ligand order-disorder transition in the temperature range investigated. The ligand phase effect is observed in the tetradecanethiol-capped gold nanoparticle films, where an abrupt change in the elastic modulus is seen near T m. The temperature (relative to T m) during the fabrication of the films is determined to play an important role in tuning the mechanical strength of these films in this temperature range by both changing the nature of the interparticle interactions and by affecting microscale film morphology.

Detection of 'Candidatus Neoehrlichia mikurensis' and other Anaplasmataceae and Rickettsiaceae in Canidae in Switzerland and Mediterranean countries.

INTRODUCTION: 'Candidatus Neoehrlichia mikurensis' is an emerging tick-borne zoonotic agent that primarily affects immunocompromised human patients. Dogs and foxes are frequently exposed to ticks, and both species are in close proximity to humans. This is the first study to systematically investigate the occurrence of 'Candidatus Neoehrlichia mikurensis' in Canidae in Europa. We analyzed 1'739 blood samples from dogs in Switzerland, Italy, Spain and Portugal and 162 blood samples from free-ranging red foxes (Vulpes vulpes) in Switzerland. All samples were tested using a previously described multiplex real-time PCR for the Anaplasmataceae family, the 'Candidatus Neoehrlichia' genus and the 'Candidatus Neoehrlichia mikurensis' species. All Anaplasmataceae positive samples were subsequently tested using specific real-time PCRs for Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis and Rickettsia helvetica. Among the tested animals, one dog from Zurich tested positive for 'Candidatus Neoehrlichia mikurensis'. The 12-year old West Highland white terrier had been splenectomized 3 months prior to the blood collection and presented with polyuria/polydipsia. Fanconi syndrome was diagnosed based on glucosuria with normoglycemia and hyperaminoaciduria. A. platys and E. canis were detected in 14/249 dogs from Sicily and Portugal; two of the dogs were coinfected with both agents. Four Swiss foxes tested positive for A. phagocytophilium. R. helvetica was detected for the first time in a red fox. In conclusion, 'Candidatus Neoehrlichia mikurensis' infection should be considered in sick dogs, particularly when immunocompromised. The pathogen seems not to be widespread in Canidae in the investigated countries. Conversely, other Anaplasmataceae were more readily detected in dogs and foxes.

INTRODUCTION: 'Candidatus Neoehrlichia mikurensis' est un agent de zoonose transmis par les tiques qui gagne en importance et concerne principalement les patients immunosupprimés. Les chiens comme les renards sont souvent concernés par des morsures de tiques et vivent en contact étroit avec les êtres humains. Dans le présent travail, nous étudions pour la première fois systématiquement la présence de 'Candidatus Neoehrlichia mikurensis' chez les canidés en Europe. Les échantillons sanguins analysés provenaient de 1'739 chiens de Suisse, d'Italie, d'Espagne et du Portugal ainsi que de 162 renards (Vulpes vulpes) de Suisse. Tous les échantillons ont été examinés avec un test de PCR multiplex en temps réel déjà publié quant à la présence d'agents de la famille des Anaplasmataceae, du genre 'Candidatus Neoehrlichia' et de l'espèce 'Candidatus Neoehrlichia mikurensis'. Les échantillons positifs aux Anaplasmataceae ont ensuite été testés avec un test PCR en temps réel spécifique quant à Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis und Rickettsia helvetica. Parmi les échantillons examinés se trouvait celui d'un chien de Zürich qui était infecté par 'Candidatus Neoehrlichia mikurensis'. Ce West Highland White Terrier de 12 ans avait été présenté pour polyurie/polydipsie; il avait été splénectomisé trois mois avant la prise de l'échantillon. Au vu d'une glycosurie et d'une hyperaminoacidurie accompagnées d'une glycémie normale, on a posé le diagnostic de syndrome de Fanconi. A. platys et E. canis ont été mis en évidence chez 14/249 chiens provenant de Sicile et du Portugal; deux chiens étaient infectés par les deux agents pathogènes. Quatre renards suisses étaient positifs à A. phagocytophilium et R. helvetica a été trouvé pour la première fois chez un renard. En résumé, on peut dire qu'une infection à 'Candidatus Neoehrlichia mikurensis' chez un chien malade doit être prise en considération comme diagnostic différentiel, particulièrement chez les anomaux immunosupprimés. Toutefois cet agent n'est pas très répandu chez les canidés des pays examinés, contrairement aux autres Anaplasmataceae spp. qui ont été trouvées plus souvent chez les chiens et les renards.

Ligand Shell Composition-Dependent Effects on the Apparent Hydrophobicity and Film Behavior of Gold Nanoparticles at the Air-Water Interface.

Nanoparticles with well-defined interfacial energy and wetting properties are needed for a broad range of applications involving nanoparticle self-assembly including the formation of superlattices, stability of Pickering emulsions, and for the control of nanoparticle interactions with biological membranes. Theoretical, simulated, and recent experimental studies have found nanometer-scale chemical heterogeneity to have important effects on hydrophobic interactions. Here we report the study of 4 nm gold nanoparticles with compositionally well-defined mixed ligand shells of hydroxyl-(OH) and methyl-(CH3) terminated alkylthiols as Langmuir films. Compositions ranging from 0-25% hydroxyl were examined and reveal nonmonotonic changes in particle hydrophobicity at the air-water interface. Unlike nanoparticles capped exclusively with a methyl-terminated alkylthiol, extensive particle aggregation is found for ligand shells containing <2% hydroxyl-terminated chains. This aggregation was lessened upon increasing the quantity of OH-terminated chains. Nanoparticles capped with 25% OH yield films of well-separated nanoparticles exhibiting a fluid-phase regime in the surface pressure vs area isotherm. Compression-expansion hysteresis, monolayer collapse, and mean nanoparticle area measurements support the TEM-observed changes in film morphology. Such clear changes in the hydrophobicity of nanoparticles based on very small changes in the ligand shell composition are shown to impact the process of interfacial nanoparticle self-assembly and are an important demonstration of nanoscale wetting with consequences in both materials and biological applications of nanoparticles that require tunable hydrophobicity.

Essential and toxic elements in seaweeds for human consumption.

Essential elements (K, Ca, P, S, Cl, Mn, Fe, Cu, Zn, Ni, Br, and I) and nonessential or toxic elements (Al, Ti, Si, Rb, Sr, As, Cd, Sn, and Pb) were determined by energy-dispersive polarized x-ray fluorescence spectrometry in 14 seaweeds purchased in local specialty stores in Italy and consumed by humans. The differences in elements between the algae species reached up to 2-4 orders of magnitude. Lithothamnium calcareum showed the highest levels of Ca, Al, Si, Fe, and Ti. Palmaria palmata showed the highest concentrations of K, Rb, and Cl. The highest content of S was in Chondrus crispus. Laminaria digitata contained the highest concentrations of total As, Cd, Sn, Br, and I. The highest concentration of Zn was in Chlorella pyrenoidosa. Ulva lactuca displayed the highest levels of Cu, Ni, Mn, and Pb. Iodine levels ranged from 3.4 in Chlorella pyrenoidosa to 7316 mg/kg(dry) in Laminaria digitata. The nutrimental importance of essential elements was assessed using nutritional requirements. The results showed that the consumption of algae might serve as an important source of the essential elements. Health risk due to the toxic elements present in seaweed was estimated using risk estimators. Total As, Cd, and Pb concentrations ranged from <1 to 67.6, to 7.2 and to 6.7 mg/kg(dry) respectively; therefore, their contribution to total elemental intake does not appear to pose any threat to the consumers, but the concentrations of these elements should be controlled to protect the consumer against potential adverse health risks.

Essential and toxic elements in honeys from a region of central Italy.

Levels of iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), zinc (Zn), mercury (Hg), cadmium (Cd), and lead (Pb) in several types of honey produced in a region of Central Italy were determined by atomic absorption spectroscopy (AAS). The degree of humidity, sugar content, pH, free acidity, combined acidity (lactones), and total acidity were also measured. These elements were found to be present in honey in various proportions depending upon (1) the area foraged by bees, (2) flower type visited for collection of nectar, and (3) quality of water in the vicinity of the hive. Strong positive correlations occurred between Pb and Hg, Pb and Cd, Pb and Fe, Pb and Cr, Hg and Cd, and Hg and Fe. The honey products synthesized in Central Italy were of good quality, but not completely free of heavy metal contamination. Compared with established recommended daily intakes, heavy metals or trace element intoxication following honey consumption in Italy was found not to be a concern for human health.

Rapid isolation of extracellular vesicles from cell culture and biological fluids using a synthetic peptide with specific affinity for heat shock proteins.

Recent studies indicate that extracellular vesicles are an important source material for many clinical applications, including minimally-invasive disease diagnosis. However, challenges for rapid and simple extracellular vesicle collection have hindered their application. We have developed and validated a novel class of peptides (which we named venceremin, or Vn) that exhibit nucleotide-independent specific affinity for canonical heat shock proteins. The Vn peptides were validated to specifically and efficiently capture HSP-containing extracellular vesicles from cell culture growth media, plasma, and urine by electron microscopy, atomic force microscopy, sequencing of nucleic acid cargo, proteomic profiling, immunoblotting, and nanoparticle tracking analysis. All of these analyses confirmed the material captured by the Vn peptides was comparable to those purified by the standard ultracentrifugation method. We show that the Vn peptides are a useful tool for the rapid isolation of extracellular vesicles using standard laboratory equipment. Moreover, the Vn peptides are adaptable to diverse platforms and therefore represent an excellent solution to the challenge of extracellular vesicle isolation for research and clinical applications.

Feline infectious peritonitis: still an enigma?

Feline infectious peritonitis (FIP) is one of the most important fatal infectious diseases of cats, the pathogenesis of which has not yet been fully revealed. The present review focuses on the biology of feline coronavirus (FCoV) infection and the pathogenesis and pathological features of FIP. Recent studies have revealed functions of many viral proteins, differing receptor specificity for type I and type II FCoV, and genomic differences between feline enteric coronaviruses (FECVs) and FIP viruses (FIPVs). FECV and FIP also exhibit functional differences, since FECVs replicate mainly in intestinal epithelium and are shed in feces, and FIPVs replicate efficiently in monocytes and induce systemic disease. Thus, key events in the pathogenesis of FIP are systemic infection with FIPV, effective and sustainable viral replication in monocytes, and activation of infected monocytes. The host's genetics and immune system also play important roles. It is the activation of monocytes and macrophages that directly leads to the pathologic features of FIP, including vasculitis, body cavity effusions, and fibrinous and granulomatous inflammatory lesions. Advances have been made in the clinical diagnosis of FIP, based on the clinical pathologic findings, serologic testing, and detection of virus using molecular (polymerase chain reaction) or antibody-based methods. Nevertheless, the clinical diagnosis remains challenging in particular in the dry form of FIP, which is partly due to the incomplete understanding of infection biology and pathogenesis in FIP. So, while much progress has been made, many aspects of FIP pathogenesis still remain an enigma.