SEROEPIDEMIOLOGICAL SCREENING OF LEISHMANIA INFECTION IN DOGS AND CATS: THE ROLE OF THE VETERINARIAN IN A HIGHLY ENDEMIC AREA IN SICILY

Western Sicily is an active focus for canine and feline leishmaniosis in the Mediterranean area. The results of the present study indicate a high exposure rate to Leishmania (about 33% dogs and 44% cats result positive or suspected) in a random population, suggesting that they are infected with L. infantum. Moreover, 5 dogs and 1 cat previously classified as apparently healthy were seropositive with a titer ≥1:160. In conclusion, veterinary surveillance of dogs/cats could help to control the increase of L. infantum infections, especially in areas of high endemicity

SEROEPIDEMIOLOGICAL SCREENING OF LEISHMANIA INFECTION IN DOGS AND CATS: THE ROLE OF THE VETERINARIAN IN A HIGHLY ENDEMIC AREA IN SICILY

BACKGROUND Leishmaniosis is a zoonotic disease caused by Leishmania spp. with a wide spectrum of clinical signs, lymphadenomegaly, skinocular lesions, weight loss, signs of renal failure [1,2]. Many subclinical cases of leishmaniasis without illness could play an important role in the maintenance of Leishmania infection in endemic areas. Veterinary surveillance of dogs/cats owners could help to update the seroprevalence status of Leishmania infantum infection in a random court of sick and apparently healthy dogs and cats from western Sicily (Bagheria and neighboring areas) using indirect fluorescent antibody test (IFAT). MATERIAL AND METHODS A total of 268 dogs and 9 cats living in western Sicily were randomly sampled during the 2020 year. Specific antibodies to L. infantum were detected using the IFAT against in-house cultured promastigotes. Leishmania strain was used as an antigen fixed on multispot microscope slides. The feline and canine sera were both prepared by serial 2-fold dilutions (1:40 to 1:5120) in phosphate buffered saline and added to the antigen-coated wells. Fluorescent anti-cat/anti-dog immunoglobulin G antibody was used for detection. CONCLUSION Western Sicily is an active focus for canine and feline leishmaniosis in the Mediterranean area. The results of the present study indicate a high exposure rate to Leishmania (about 33% dogs and 44% cats result positive or suspected) in a random population, suggesting that they are infected with L. infantum. Moreover, 5 dogs and 1 cat previously classified as apparently healthy were seropositive with a titer ≥1:160. In conclusion, veterinary surveillance of dogs/cats could help to control the increase of L. infantum infections, especially in areas of high endemicity. RESULTS 49/268 (18.3%) sampled dogs tested positive to IFAT with a titer ≥1:160 and 40/268 (15%) tested suspected (titers 1:40-1:80), for L.infantum infection (Table 1). An additional 2/9 (22.2%) cats were seropositive with a titer of 1:160 and 2/9 (22.2%) cats were seropositive with a titer of 1:80 (Table 1). Figure 1 shows geographical distribution of L. infantum seroprevalenc in dogs/cats sampled from western Sicily. CONCLUSION Western Sicily is an active focus for canine and feline leishmaniosis in the Mediterranean area. The results of the present study indicate a high exposure rate to Leishmania (about 33% dogs and 44% cats result positive or suspected) in a random population, suggesting that they are infected with L. infantum. Moreover, 5 dogs and 1 cat previously classified as apparently healthy were seropositive with a titer ≥1:160. In conclusion, veterinary surveillance of dogs/cats could help to control the increase of L. infantum infections, especially in areas of high endemicity

Atmospheric pressure plasma jet for surface texturing of C/SiC

C/SiC composites are materials to be used in harsh environments overcoming the limits imposed by the intrinsic brittleness of their ceramic constituents while providing both high mechanical performances at high-temperature temperatures and low weight. In order to manufacture the final component, joining C/SiC, to itself or to other materials, is often necessary, and it is critical to maximize the strength of the joints (similar or dissimilar) in order to meet reliability criteria. In the present work, a pre-joining treatment based on an atmospheric pressure plasma jet (APPJ) was proposed to introduce a brush-like texture on the surface via the selective removal of carbon fibers. The investigation of treated surfaces via electron microscopy and confocal 3D-profilometry confirmed that the treatment was effective in introducing a brush-like texture and in increasing the available contact area. Wettability test and inspection of cross-section of CB4 wetted samples were then carried out. The latter confirmed the formation of anchoring points given by the brush-like texture. Finally, the effectiveness of the treatment in improving the joint strength was assessed by comparing the apparent shear strength of CB4 brazed composites, with and without the APPJ pre-treatment. The joints with plasma pre-treated C/SiC showed a shear strength of about 66 MPa, 44% more than the strength of joints produced with untreated C/SiC

Design of Lu2O3-reinforced Cf/SiC-ZrB2-ZrC ultra-high temperature ceramic matrix composites: Wetting and interfacial reactivity by ZrSi2 based alloys

Abstract The wettability and infiltration of molten ZrSi2 and ZrSi2-Lu2O3 alloys into Cf/SiC and B4C-infiltrated Cf/SiC composites were investigated to understand the interfacial interactions that occur during the development of Cf/SiC-ZrC and Cf/SiC-ZrB2-ZrC-Lu2O3 materials. A significant evaporation of Si from the liquid affected the wetting behaviour of the alloy when tested in a vacuum at 1670 °C. The better wetting and spreading of the alloy over the surface was observed for the composites with lower overall porosity (12 %). On the other hand, the formation of an outer dense layer, followed up by the uniform infiltrated region up to ∼ 1 mm was observed for the Cf/SiC with higher porosity (21 %). The infiltrated alloy reacted with SiC matrix to form ZrC or with B4C-infiltrated SiC matrix to form ZrB2-ZrC-SiC. The Lu2O3 particles were not wetted by the melt, and were pushed away of the reaction zone by the solidification front

EUROMAT 2019 Symposia on Processing

This issue of JMEP contains invited, peer-reviewed papers presented at the European Congress and Exhibition on Advanced Materials and Processes (EUROMAT 2019), held on September 1–5, 2019, in Stockholm, Sweden, in two symposia from the Area C “Processing”: C6 “Joining,” organized by Anna Zervaki (University of Thessaly, Greece), Ivan Kaban (IFW Dresden, Germany), and C. Sommitsch (Technische Universität Graz, Austria) C8 “Interface Design and Modelling, Wetting, and High-Temperature Capillarity,” organized by Pavel Protsenko (M.V. Lomonosov Moscow State University, Russian Federation), Fabrizio Valenza (CNR—ICMATE, Genoa, Italy), and Simeon Agathopoulos (University of Ioannina, Greece) The research works in the field of joining technologies, presented at the C6 symposium, concerned soldering, brazing, diffusion bonding, resistance spot welding, friction stir welding, and riveting techniques. The symposium C8 covered research topics on grain boundary wetting, surface energy of liquid metals and interfacial phenomena, considering fundamental as well as applied issues related to materials joining, and interface design. We wish to thank the authors for the written contributions and acknowledge the reviewers for their careful reading and evaluation of the manuscripts and valuable suggestions to improve the quality of the papers. We are grateful to the editor-in-chief of JMEP, Dr. Rajiv Asthana, and the ASM journal staff, including Mary Anne Fleming, senior content developer; Kate Doman, content developer (journals); and Vincent Katona, production coordinator; for the opportunity to publish the symposia contributions in this issue and for their professional and friendly support during the entire reviewing and publication process. We hope this collection will stimulate fresh thinking and promote further research on joining and interfacial phenomena

FELINE LEISHMANIASIS: SEROLOGICAL AND MOLECULAR DETECTION OF AN EMERGENT DISEASE IN A NON-ENDEMIC AREA OF NORTHERN ITALY

In recent decades feline leishmaniosis (FeL) has become an emerging disease, also in non-endemic areas for the canine infection. This study updates the epidemiological status for FeL in cats in northern Italy and compares results with previous studies of the same feline population. Co-infections with feline retroviruses FIV and Field were also investigated. Stray, shelter and owned cats from different cities in the Lombardy region of northern Italy, were prospectively randomly sampled between January 2020 and May 2021. A total of 255 cats were tested for L. infantum: 240/255 for antibodies by IFAT and 234/255 and 198/255 for Leishmania DNA by PCR on whole blood and lymph nodes, respectively. Rapid ELISA test was used to detect FIV or FeLV infection. Overall, 26/255 (10.2%) cats tested positive for L. infantum: in 8/26 cats Leishmania DNA was found in popliteal lymph nodes (Leishmania/ml range from 15 to 60), 6/26 were PCR positive on whole blood (Leishmania/ml range from 5 to 80) and 15/26 IFAT seropositive at titers ranging from 1:80 to 1:320. Two Leishmania infected cats were also FIV+FeLV coinfected, another was FIV positive and one was FeLV positive. A high prevalence of FeL was found in a non-endemic area of northern Italy, with an increasing trend in infection rates

Understanding the Role of Surface Modification of Randomized Trabecular Titanium Structures in Bone Tissue Regeneration: An Experimental Study

Background and Objectives: Three-dimensional (3D) metallic trabecular structures made by additive manufacturing (AM) technologies promote new bone formation and osteointegration. Surface modifications by chemical treatments can improve the osteoconductive properties of metallic structures. An in vivo study in sheep was conducted to assess the bone response to randomized trabecular titanium structures that underwent a surface modification by chemical treatment compared to the bone response to the untreated specimens. Material and Methods: Sixteen specimens with a randomized trabecular titanium structure were implanted in the spongious bone of the distal femur and proximal tibia and the cortical bone of the tibial diaphysis of two sheep. Of them, eight implants had undergone a chemical treatment (treated) and were compared to eight implants with the same structure but native surfaces (native). The sheep were sacrificed at 6 weeks. Surface features of the lattice structures (native and treated) were analyzed using a 3D non-contact profilometer. Compression tests of 18 lattice cubes were performed to investigate the mechanical properties of the two structures. Excellent biocompatibility for the trabecular structures was demonstrated in vitro using a cell mouse fibroblast culture. Histomorphometric analysis was performed to evaluate bone implant contact and bone ingrowth. Results: A compression test of lattice cubic specimens revealed a comparable maximum compressive strength value between the two tested groups (5099 N for native surfaces; 5558 N for treated surfaces; p > 0.05). Compared to native surfaces, a homogenous formation of micropores was observed on the surface of most trabeculae that increased the surface roughness of the treated specimens (4.3 versus 3.2 µm). The cellular viability of cells seeded on three-dimensional structure surfaces increased over time compared to that on plastic surfaces. The histomorphometric data revealed a similar behavior and response in spongious and cortical bone formation. The percentage of the implant surface in direct contact with the regenerated bone matrix (BIC) was not significantly different between the two groups either in the spongious bone (BIC: 27% for treated specimens versus 30% for native samples) or in the cortical bone (BIC: 75% for treated specimens versus 77% for native samples). Conclusions: The results of this study reveal rapid osseointegration and excellent biocompatibility for the trabecular structure regardless of surface treatment using AM technologies. The application of implant surfaces can be optimized to achieve a strong press-fit and stability, overcoming the demand for additional chemical surface treatments

ZrB 2-SiC/Ti6Al4V joints: Wettability studies using Ag- and Cu-based braze alloys

In this paper, a study is presented on the wettability of ZrB 2 ceramics (pure ZrB 2 and ZrB 2-SiC composite) and of the Ti6Al4V alloy by pure Cu and Ag and their alloys with Ti to be used in subsequent brazing processes. Wettability tests aimed at elucidating the interfacial interactions and the role of active metal additions (i.e. Ti) in the brazing procedure, performed in a temperature range between 950 and 1150 \ub0C, showed that Cu wets pure ZrB 2 quite well (contact angle \u3b8 = 70\ub0), while Ag does not. The composite was wetted in a similar way by Cu, while for Ag a \u3b8 = 97\ub0 was found. The addition of Ti improved the wetting (\u3b8 between \u3030\ub0 and 20\ub0) and segregation at the metal- ceramic interface occurred. As expected, both Cu(Ti) and Ag(Ti) wetted the Ti6Al4V alloy very well. In particular, it was shown that Cu can already produce a liquid phase at 950 \ub0C with partial dissolution of the solid phase. These results are discussed in terms of interfacial reactions and taking into account the sintering aids used for the ceramic body. This study is aimed at defining a brazing process that leads to reliable metal-ceramic joints as a result of chemical interactions of the liquid phase with and diffusion into the adjoining solids. Exploratory joining tests were performed that showed, by means of shear tests coupled with microstructural and microchemical description of the interfaces, the possibility to design sound ZrB 2-SiC/Ti6Al4V joints. \ua9 Springer Science+Business Media, LLC 2012

Ag as brazing metal in Ti6Al4V/Ag/YAG joints: galvanic effects in seawater

The electrochemical behavior of Ag and AgCu, used as brazing material, was compared in Ti6Al4V/YAG (Yttrium-Aluminium garnet) joints. The concern was about galvanic effects in seawater, which can cause possible sources of weakness of the interlayer. Ag and AgCu brazed Ti6Al4V/YAG joints have been already tested in terms of wettability and interfacial reactivity elsewhere. In the present work, Ti6Al4V/Ag/YAG and Ti6Al4V/AgCu/YAG samples were initially immersed for four weeks in a seawater mesocosm. SEM observations showed that the interlayer resulting from AgCu brazing was locally corroded due to Cu depletion. On the other hand, Ag-based interlayer appeared integer. Hence, Ag behavior, as brazing material, was further investigated. Although Ag and Ti6Al4V can be regarded as noble-behaving materials, in case of Ag behaving as an anode, possible worsening effects due to coupling it with Ti6Al4V can be related to the geometry of the system, since Ti6Al4V has a more extensive area than the interlayer, and the environment of application, since Ti6Al4V can enhance cathodic effects due to its ennoblement induced by biofilm growing. Therefore, the study of the Ag interlayer was performed using Ti6Al4V and Ag electrodes, coupled and not coupled, immersed in seawater. Biofilm induced ennoblement was investigated by comparison with 254 SMO/Ag systems. After 4 weeks, the couples were disconnected, open circuit potential was monitored for 1 hour, potentiodynamic polarization curves were performed. Freely corroding electrodes were polarized as well. Results show that Ag behaved initially as a cathode in 254 SMO/Ag and Ti6Al4V/Ag couples; after few days, reversal of polarization was observed, making Ag behaving as an anode. This event was a stable feature only for the 254 SMO/Ag couples, and this trend was consistent with freely corroding electrode behaviors: the corrosion potential of 254 SMO electrodes shifted to potentials larger than that of Ag, with sigmoidal kinetic, typical of biofilm ennoblement; on the other hand, Ti6Al4V potential shifted to potentials comparable to Ag ones, with a saturation kinetic typical of passivation layer strengthening. Important evidences about Ti6Al4V/Ag couples were: a) Ti6Al4V did not undergo biofilm induced ennoblement, b) galvanic current densities on Ag were about 10-6 A cm-2, whatever the sign of the current. Then, Ag, better than AgCu, can be used as brazing metal for Ti6Al4V/interlayer/YAG joints in seawater, since no appreciable galvanic effects occur