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The aim of this study was to evaluate the effects of immunising farm animals with the Histophilus somni recombinant heat shock protein 60kDa (H. somni rHsp60) in field conditions. Fifty piglets, 10 calves and 30 hens were immunised twice, and the same number of each species was used as the control. The humoral immune response was evaluated using ELISA in piglets (IgG, IgA and IgM) and calves (IgG1, IgG2 and IgM) sera and in hen egg yolks (IgY). Cell-mediated immune responses were evaluated using the skin test. Concentrations of serum haptoglobin in calves and piglets and plasma fibrinogen in calves, daily weight gain in piglets, as well as the inner body temperature and clinical signs in calves were measured to evaluate the clinical effects of vaccination. In animals immunised twice with H. somni rHsp60, a statistically significant increase in IgY antibodies in egg yolk as well as serum IgG1 and IgG2 antibodies in calves (P < 0.05) was found. In piglets, the antibody reaction against H. somni rHsp60 was higher in the experimental than in the control group, but the difference was significant only for the IgG class (P < 0.05). A moderate cell-mediated immune response to H. somni rHsp60 measured using the skin test was observed in piglets after 24 h (P < 0.05), but not in calves and hens. The daily weight gain was significantly higher in the experimental than in the control piglets (P < 0.05). The fibrinogen and haptoglobin levels in calves, as well as the inner body temperature, indicated a reduced risk of pathology in the experimental group of calves. The preliminary results confirmed the immunogenicity of H. somni rHsp60. A beneficial effect on piglet weight gain was observed. The obtained results warrant further studies of the protective effects of H. somni rHsp60 as an ingredient of subunit vaccines in farm animals.

This work describes the application of laser ion source (LIS) for fabrication of semiconductor nanostructures, as well as relevant equipment completed and tested in the IPPLM for the EU STREP “SEMINANO” project and the obtained experimental results. A repetitive pulse laser system of parameters: energy of ∼0.8 J in a 3.5 ns-pulse, wavelength of 1.06 μm, repetition rate of up to 10 Hz and intensity on the target of up to 1011 W/cm2, has been employed to produce Ge ions intended for ion implantation into SiO2 substrate. Simultaneously, laser-ablated material (atoms clusters debris) was deposited on the substrate surface. The parameters of the Ge ion streams (energy and angular distributions, charge states, and ion current densities) were measured with the use of several ion collectors and an electrostatic ion energy analyzer. The SiO2 films of thickness from 20–400 nm prepared on substrates of a single Si crystal were deposited and implanted with the use of laser-produced germanium of different properties. The modified SiO2 layers and sample surface properties were characterized with the use of different methods: X-ray photoelectron and Auger electron spectroscopy (XPS+AES), Raman scattering spectroscopy (RSS) and scanning electron microscopy (SEM). The production of the Ge nano-crystallites has been demonstrated for annealed samples prepared in different experimental conditions. [ABSTRACT FROM AUTHOR]

Bovine respiratory disease (BRD) causes significant economic losses in dairy calves. Induction of an early immune response via parenteral vaccination is complicated by the interference of colostral immunity. In this study, we investigated early immunization against selected conserved bacterial antigens. Calves were vaccinated twice intranasally and then subcutaneously with Histophilus somni recombinant proteins (rOMP40 or rHsp60) mixed with one of two adjuvants: CpG ODN2007 or MPLA. The control group (Con) was treated with PBS. The first immunization was done between 24 and 48 h of life and then twice in two weeks intervals. Blood, nasal, and saliva secretion samples were collected directly before vaccination (S1-S3) and then on 42-44 (S4) and 59-61 (S5) day of life. Antibodies (IgG 1 /IgG 2 /IgM/IgA in serum; IgG 1 /IgA in secretions) against both vaccine antigens were quantified in all samples. Intranasal and subcutaneous vaccinations using the described formulas did not increase antibody reactivity against the tested proteins. The reactivity of serum IgG 1 , IgM, and IgA anti-rOMP40 antibodies was significantly higher in S1 in all groups than that in the other samplings (p˂0.01). Significant differences in the reactivity of serum anti-rOMP40 antibodies between groups were identified in S1 (IgA reactivity was higher in the CpG vs. MPLA group; p < 0.05), S4 (IgM reactivity was higher in Con vs. CpG group; p < 0.05), and S5 (IgG1 reactivity was higher in MPLA vs. Con group; p < 0.05). The lack of consistent changes in antibodies after immunization (S4 and S5) hinders the drawing of conclusions regarding the effect of immunization on antibody reactivity. In the future, establishing a proper immunization window and adjuvants for nasal vaccines against bacterial pathogens causing BRD in calves remains to be determined., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethics approval and consent to participate All experiments were performed in accordance with the recommendations set forth in the Act on Animal Protection (Journal of Laws of 1997, No. 111, Item 724) and approved by the Local Ethics Committee for Animal Experiments in Wroclaw (Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences), permission no. 030/2019/P1. The study was conducted in compliance with the ARRIVE 2.0 Essential 10 list. Permission of the owner was obtained to carry out this study in the herd., (© 2024. The Author(s).)

ZnFe 2 O 4 is an n-type semiconductor spinel oxide with promising applications in various fields, including photocatalysis. This study reports the successful synthesis of a novel ZnFe 2 O 4 derivative based on Prussian Blue Analogues (PBAs) through an electrosynthesis method. To enhance photocatalytic performance, the synthesized ZnFe 2 O 4 was employed as a cocatalyst in p-n junction materials, specifically CuO/ZnFe 2 O 4 . Our findings reveal that introducing ZnFe 2 O 4 could significantly improve the photocatalytic activity and hydrogen (H 2 ) production rate of the CuO/ZnFe 2 O 4 system compared to bare CuO. This enhancement was sustained over an extended operational period, indicating the material's potential for long-term use in photocatalytic applications. The superior performance of the ZnFe 2 O 4 cocatalyst is attributed to its efficient charge separation and improved light absorption properties, which collectively contribute to higher photocatalytic efficiency. This study highlights the potential of PBA-based derivative ZnFe 2 O 4 as an effective cocatalyst in developing advanced photocatalytic systems for sustainable hydrogen production., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

One-dimensional (1D) ordered TiO 2 nanotubes exhibit exceptional charge transfer capabilities, making them suitable candidates for constructing visible-light-active photoanodes in selective PEC oxidation reactions. Herein, we employed a facile and easily scalable electrochemical method to fabricate Au-CoO x -deposited ordered TiO 2 nanotubular array photoanodes. The improved visible light absorption capacity of TiO 2 -Au-CoO x , with unhampered 1D channels and the controlled integration of Au between TiO 2 and CoO x , along with their synergistic interaction, have been identified as the most promising strategy for enhanced PEC performance, as evidenced by an IPCE of 3.7% at 450 nm. Furthermore, the robust interfacial charge transfer pathway from CoO x to the TiO 2 surface via the Au mediator promotes the migration of photogenerated electrons and enables the accumulation of holes on the surface of CoO x . These holes are then efficiently utilized by oxidants such as methanol or lignin to generate value-added products, highlighting the potential of this system for advanced PEC applications.

This study presents a novel approach to fabricating anodic Co-F-WO 3 layers via a single-step electrochemical synthesis, utilizing cobalt fluoride as a dopant source in the electrolyte. The proposed in situ doping technique capitalizes on the high electronegativity of fluorine, ensuring the stability of CoF 2 throughout the synthesis process. The nanoporous layer formation, resulting from anodic oxide dissolution in the presence of fluoride ions, is expected to facilitate the effective incorporation of cobalt compounds into the film. The research explores the impact of dopant concentration in the electrolyte, conducting a comprehensive characterization of the resulting materials, including morphology, composition, optical, electrochemical, and photoelectrochemical properties. The successful doping of WO 3 was confirmed by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, photoluminescence measurements, X-ray photoelectron spectroscopy (XPS), and Mott-Schottky analysis. Optical studies reveal lower absorption in Co-doped materials, with a slight shift in band gap energies. Photoelectrochemical (PEC) analysis demonstrates improved PEC activity for Co-doped layers, with the observed shift in photocurrent onset potential attributed to both cobalt and fluoride ions catalytic effects. The study includes an in-depth discussion of the observed phenomena and their implications for applications in solar water splitting, emphasizing the potential of the anodic Co-F-WO 3 layers as efficient photoelectrodes. In addition, the research presents a comprehensive exploration of the electrochemical synthesis and characterization of anodic Co-F-WO 3 , emphasizing their photocatalytic properties for the oxygen evolution reaction (OER). It was found that Co-doped WO 3 materials exhibited higher PEC activity, with a maximum 5-fold enhancement compared to pristine materials. Furthermore, the studies demonstrated that these photoanodes can be effectively reused for PEC water-splitting experiments.

Introduction: The aim of the study was to monitor the occurrence of selected vector-borne diseases in anaemic dogs arriving in or returning to Poland from areas endemic for these diseases., Material and Methods: The study involved 497 dogs, of which 184 came to Poland from Ukraine with their owners fleeing the war. Other animals returned to the country from holidays spent in Croatia (n = 96), Turkey (n = 79), Italy (n = 48), Bulgaria (n = 42), Albania (n = 36) and Romania (n = 12). Molecular biology methods were used for detection of pathogens transmitted by the vectors., Results: Molecular tests revealed the presence of vector-borne pathogens in 79 dogs. The most commonly diagnosed infection was caused by Babesia canis (27 dogs), followed by infections with Anaplasma phagocytophilum (in 20 dogs), Mycoplasma haemocanis (15 dogs), Bartonella henselae (7 dogs), Ehrlichia canis (4 dogs), Hepatozoon canis (3 dogs), Babesia gibsoni (2 dogs) and Leishmania infantum (1 dog). Most of the sick dogs (n = 39) came from Ukraine. In dogs spending holidays with their owners outside Poland, vector-borne diseases were most often detected after their return from Turkey (n = 16), and next in descending order from Croatia (n = 7), Italy (n = 6), Albania (n = 4), Bulgaria (n = 4) and Romania (n = 3)., Conclusion: The wider migration crisis and increasingly frequent trips of owners with their dogs to areas of endemic infectious and parasitic diseases observed in recent years are the main risk factors for the occurrence of these diseases in Poland. Therefore, constant monitoring of vector-borne diseases, especially in dogs returning from holidays and arriving in Poland from abroad, seems to be crucial for their early detection and introduction of appropriate therapy., Competing Interests: Conflict of Interests Statement: The authors declare that there is no conflict of interests regarding the publication of this article., (© 2024 Łukasz Adaszek et al., published by Sciendo.)

Canine hepatozoonosis is a tick-borne protozoal disease. Two species of Hepatozoon may infect dogs: Hepatozoon americanum and H. canis. The aim of the paper was to attempt to detect the genetic material of H. canis in blood samples collected from dogs suspected to suffer from tick-borne diseases. 107 samples were tested with the use of the real-time PCR technique (Vcheck M Bionote analyser), of which 99 were collected from dogs which never left Polish territory (group 1) and 8 from dogs which spent the holidays with their owners in Turkey (group 2). DNA of H. canis was detected in 1 dog in group 1 (with Ixodes ricinus infestation), and in 2 dogs in group 2 (with Ripicephalus sanguineus infestation). The results obtained indicate that infections with H. canis should be taken into account and included in the differential diagnosis of vector-borne diseases in dogs in Poland, and the accurate identification of the infection agent is crucial for developing the correct treatment regimen and prognosis., (© 2024 The Authors. This is an open access article under the CC BY-NC-ND 4.0 license (https://creativecommons.org/licenses/by-nc-nd/4.0/deed.en), which allows re-users to copy and distribute the material in any medium or format in unadapted form and for noncommercial purposes, and only so long as attribution is given to the creator.)

Literature data has shown that reactive oxygen species (ROS), generated by immune cells during post-operative inflammation, could induce corrosion of standard Ti-based biomaterials. For Ti6Al4V alloy, this process can be further accelerated by the presence of albumin. However, this phenomenon remains unexplored for Ti β-phase materials, such as TiNb alloys. These alloys are attractive due to their relatively low elastic modulus value. This study aims to address the question of how albumin influences the corrosion resistance of TiNb alloy under simulated inflammation. Electrochemical and ion release tests have revealed that albumin significantly enhances corrosion resistance over both short (2 and 24 h) and long (2 weeks) exposure periods. Furthermore, post-immersion XPS and cross-section TEM analysis have demonstrated that prolonged exposure to an albumin-rich inflammatory solution results in the complete coverage of the TiNb surface by a protein layer. Moreover, TEM studies revealed that H 2 O 2 -induced oxidation and further formation of a defective oxide film were suppressed in the solution enriched with albumin. Overall results indicate that contrary to Ti6Al4V, the addition of albumin to the PBS + H 2 O 2 solution is not necessary to simulate the harsh inflammatory conditions as could possibly be found in the vicinity of a TiNb implant., (© 2024 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals LLC.)

The aim of the study was to compare the serum protein profile of Bernese Mountain Dogs (BMDs) reacting positive for Bb in snap testing with the serum protein profile of dogs of other breeds (healthy and with clinical borreliosis) using the MALDI time-of-flight (MALDI-TOF) technique. The observations included five groups of dogs. BMDs reacting positively to Bb in snap serological testing and showing symptoms of borreliosis (group 1), BMDs for which no borreliosis symptoms were determined but with seropositivity for Bb determined with snap serological tests (group 2), clinically healthy BMDs with no antibodies for Bb found in the serum (group 3), five dogs of different breeds, reacting positively in serological testing, in which borreliosis symptoms were observed (group 4), clinically healthy dogs of different breeds with negative reaction in tests towards Bb (group 5). A proteomic analysis demonstrated the presence of five identical protein fractions among all five groups. An additional two protein fractions of approximately 7.630 and 15.260 kDa were found in all the serum samples obtained from the dogs positive for borrelia in a snap test, both in those exhibiting symptoms of borreliosis, and seropositive BMDs not presenting symptoms of the disease. These two additional protein fractions may be used to differentiate between seropositive and seronegative B. burgdorferi dogs and may be considered a seropositivity marker, however, it cannot be used to differentiate between animals with the clinical form of the disease and those that are only seropositive., (Copyright© by the Polish Academy of Sciences.)

Dental implants have become a routine, affordable, and highly reliable technology to replace tooth loss. In this regard, titanium and its alloys are the metals of choice for the manufacture of dental implants because they are chemically inert and biocompatible. However, for special cohorts of patients, there is still a need for improvements, specifically to increase the ability of implants to integrate into the bone and gum tissues and to prevent bacterial infections that can subsequently lead to peri-implantitis and implant failures. Therefore, titanium implants require sophisticated approaches to improve their postoperative healing and long-term stability. Such treatments range from sandblasting to calcium phosphate coating, fluoride application, ultraviolet irradiation, and anodization to increase the bioactivity of the surface. Plasma electrolytic oxidation (PEO) has gained popularity as a method for modifying metal surfaces and delivering the desired mechanical and chemical properties. The outcome of PEO treatment depends on the electrochemical parameters and composition of the bath electrolyte. In this study, we investigated how complexing agents affect the PEO surfaces and found that nitrilotriacetic acid (NTA) can be used to develop efficient PEO protocols. The PEO surfaces generated with NTA in combination with sources of calcium and phosphorus were shown to increase the corrosion resistance of the titanium substrate. They also support cell proliferation and reduce bacterial colonization and, hence, lead to a reduction in failed implants and repeated surgeries. Moreover, NTA is an ecologically favorable chelating agent. These features are necessary for the biomedical industry to be able to contribute to the sustainability of the public healthcare system. Therefore, NTA is proposed to be used as a component of the PEO bath electrolyte to obtain bioactive surface layers with properties desired for next-generation dental implants.

The rapidly growing production and usage of lithium-ion batteries (LIBs) dramatically raises the number of harmful wastes. Consequently, the LIBs waste management processes, taking into account reliability, efficiency, and sustainability criteria, became a hot issue in the context of environmental protection as well as the scarcity of metal resources. In this paper, we propose for the first time a functional material-a magnetorheological fluid (MRF) from the LIBs-based liquid waste containing heavy metal ions. At first, the spent battery waste powder was treated with acid-leaching, where the post-treatment acid-leaching solution (ALS) contained heavy metal ions including cobalt. Then, ALS was used during wet co-precipitation to obtain cobalt-doped superparamagnetic iron oxide nanoparticles (SPIONs) and as an effect, the harmful liquid waste was purified from cobalt. The obtained nanoparticles were characterized with SEM, TEM, XPS, and magnetometry. Subsequently, superparamagnetic nanoparticles sized 15 nm average in diameter and magnetization saturation of about 91 emu g -1 doped with Co were used to prepare the MRF that increases the viscosity by about 300% in the presence of the 100 mT magnetic fields. We propose a facile and cost-effective way to utilize harmful ALS waste and use them in the preparation of superparamagnetic particles to be used in the magnetorheological fluid. This work describes for the first time the second life of the battery waste in the MRF and a facile way to remove the harmful ingredients from the solutions obtained after the acid leaching of LIBs as an effective end-of-life option for hydrometallurgical waste utilization.

Exfoliated g-C 3 N 4 is a well-known semiconductor utilized in heterogenous photocatalysis and water splitting. An improvement in light harvesting and separation of photogenerated charge carriers may be obtained by polymer doping with sulfur. In this work, we incorporate sulfur into the polymer chain by chemical polymerization of trithiocyanuric acid (C 3 N 3 S 3 H 3 ) to obtain C 3 N 3 S 3 . The XRD measurements and TEM images indicated that C 3 N 3 S 3 , in contrast to g-C 3 N 4 , does not exist in the form of a graphitic structure and is not exfoliated into thin lamellas. However, both polymers have similar optical properties and positions of the conduction and valence bands. The comparative studies of electrochemical oxygen reduction and hydrogen evolution indicated that the overpotentials for the two processes were smaller for C 3 N 3 S 3 than for g-C 3 N 4 . The RDE experiments in the oxygen-saturated solutions of 0.1 M NaOH have shown that O 2 is electrochemically reduced via the serial pathway with two electrons involved in the first step. The spectroscopic experiments using NBT demonstrated that both polymers reveal high activity in the photocatalytic reduction of oxygen to superoxide anion radical by the photogenerated electrons.

Borreliosis is the most frequently diagnosed tick-borne disease caused by spirochete bacteria belonging to the genus Borreliae - Borrelia burgdorferi sensu stricto (s.s.), Borrelia afzelii and Borrelia garinii. Clinical manifestations in dogs include fever, lameness, polyarthritis and glomerulonephritis. Diagnosis is mainly serological and is based on an immunoenzymatic test followed by a Western blot confirmatory test. Early treatment with antibiotics such as doxycycline or amoxicillin, for four weeks, usually reduces the risk of chronic disease. Tick control, including tick repellents, is highly reliable in preventing transmission. Vaccines are available to reduce transmission and the clinical manifestations of infection in dogs. Bernese Mountain Dogs are a breed that often test positive for antibodies against B. burgdorferi without showing any clinical symptoms of the disease. Quantitative determination of the immunoglobulin level for spirochetes has indicated that Bernese Mountain Dogs may have an increased susceptibility to Borrelia spp. infections of a hereditary nature., (Copyright© by the Polish Academy of Sciences.)

Background: Gram-negative bacterial infections are a serious problem in beef and dairy cattle. Bacterial outer membrane proteins (OMPs) play a pivotal role in cellular survival and the host-bacterium interaction. Histophilus somni OMP40 was identified as a porin with homology between its N-terminal amino acid sequence and the sequences of porins of other gram-negative bacteria The aim of this study was to produce recombinant H. somni OMP40 (rOMP40), optimize its production and evaluate its immunogenic properties in calves. The cross-reactivity of anti-rOMP40 antibodies were also checked., Results: The highest overexpression of rOMP40 was demonstrated by Escherichia coli C41 using the autoinduction process. Double immunization of calves (20 μg rOMP40 per animal) induced a significant increase of anti-rOMP40 antibodies in the IgG 1 (P ≤ 0.01) and IgG 2 (P ≤ 0.01, after first immunization only) subclasses, but not IgM. ELISA revealed increased reactivity of the IgG against surface antigens of E. coli and Pasteurella multocida after the second immunization (P < 0.01). Cross reactivity of anti-rOMP40 antibodies with ~ 40 kDa antigens of most common gram-negative pathogens was shown by Western blotting., Conclusion: Immunization with H. somni rOMP40 induced a humoral response in cattle with broad cross-reactivity with similar antigens of other species of Pasteurellaceae and Enterobacteriaceae families and the delayed-type hypersensitivity reaction. The obtained results encourage further study to evaluate the protective effect of the produced protein as a subunit vaccine in cattle., (© 2022. The Author(s).)

Electrochemically generated nanoporous tin oxide films have already been studied as photoanodes in photoelectrochemical water splitting systems. However, up to now, the most significant drawback of such materials was their relatively wide band gap (ca. 3.0 eV), which limits their effective performance in the UV light range. Therefore, here, we present for the first time an effective strategy for sensitization of porous anodic SnO x films with another narrow band gap semiconductor. Nanoporous tin oxide layers were obtained by simple one-step anodic oxidation of metallic Sn in 1 M NaOH followed by further surface decoration with CdS by the successive ionic layer adsorption and reaction (SILAR) method. It was found that the nanoporous morphology of as-anodized SnO x is still preserved after CdS deposition. Such SnO x /CdS photoanodes exhibited enhanced photoelectrochemical activity in the visible range compared to unmodified SnO x . However, the thermal treatment at 200 °C before the SILAR process was found to be a key factor responsible for the optimal photoresponse of the material.

Powder bed fusion using a laser beam (PBF-LB) is a commonly used additive manufacturing (3D printing) process for the fabrication of various parts from pure metals and their alloys. This work shows for the first time the possibility of using PBF-LB technology for the production of 3D titanium substrates (Ti 3D) for surface-enhanced Raman scattering (SERS) measurements. Thanks to the specific development of the 3D titanium surface and its nanoscale modification by the formation of TiO 2 nanotubes with a diameter of ~80 nm by the anodic oxidation process, very efficient SERS substrates were obtained after deposition of silver nanoparticles (0.02 mg/cm 2 , magnetron sputtering). The average SERS enhancement factor equal to 1.26 × 10 6 was determined for pyridine (0.05 M + 0.1 M KCl), as a model adsorbate. The estimated enhancement factor is comparable with the data in the literature, and the substrate produced in this way is characterized by the high stability and repeatability of SERS measurements. The combination of the use of a printed metal substrate with nanofunctionalization opens a new path in the design of SERS substrates for applications in analytical chemistry. Methods such as SEM scanning microscopy, photoelectron spectroscopy (XPS) and X-ray diffraction analysis (XRD) were used to determine the morphology, structure and chemical composition of the fabricated materials.

The CuO@CuFe 2 O 4 core-shell structure represents a new family of photocatalysts that can be used as photoelectrodes that are able to produce hydrogen under a broad spectrum of visible light. Herein, we report a novel approach for the production of this active film by the thermal conversion of CuFe Prussian Blue Analogues. The outstanding photoelectrochemical properties of the photocathodes of CuO@CuFe 2 O 4 were studied with the use of combinatory photo-electrochemical instrumental techniques which proved that the electrodes were stable over the whole water photolysis run under relatively positive potentials. Their outstanding performance was explained by the coupling of two charge transfer mechanisms occurring in core-shell architectures.

The structural and chemical modification of TiO 2 nanotubes (NTs) by the deposition of a well-controlled Au deposit was investigated using a combination of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), Raman measurements, UV-Vis spectroscopy and photoelectrochemical investigations. The fabrication of the materials focused on two important factors: the deposition of Au nanoparticles (NPs) in UHV (ultra high vacuum) conditions (1-2 × 10 -8 mbar) on TiO 2 nanotubes (NTs) having a diameter of ∼110 nm, and modifying the electronic interaction between the TiO 2 NTs and Au nanoparticles (NPs) with an average diameter of about 5 nm through the synergistic effects of SMSI (Strong Metal Support Interaction) and LSPR (Local Surface Plasmon Resonance). Due to the formation of unique places in the form of "hot spots", the proposed nanostructures proved to be photoactive in the UV-Vis range, where a characteristic gold plasmonic peak was observed at a wavelength of 580 nm. The photocurrent density of Au deposited TiO 2 NTs annealed at 650 °C was found to be much greater (14.7 μA cm -2 ) than the corresponding value (∼0.2 μA cm -2 ) for nanotubes in the as-received state. The IPCE (incident photon current efficiency) spectral evidence also indicates an enhancement of the photoconversion of TiO 2 NTs due to Au NP deposition without any significant change in the band gap energy of the titanium dioxide ( E g ∼3.0 eV). This suggests that a plasmon-induced resonant energy transfer (PRET) was the dominant effect responsible for the photoactivity of the obtained materials., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Coating magnesium alloys with nitride surface layers is a prospective way of improving their intrinsically poor surface properties; in particular, their tribological and corrosion resistance. These layers are usually produced using PVD methods using magnetron sputtering or arc evaporation. Even though the thus-produced layers significantly increase the wear resistance of the alloys, their effects on corrosion resistance are unsatisfactory because of the poor tightness, characteristic of PVD-produced products. Tightness acquires crucial significance when the substrate is a highly-active magnesium alloy, hence our idea to tighten the layers by subjecting them to a post-deposition chemical-hydrothermal-type treatment. This paper presents the results of our experiments with a new hybrid surface engineering method, using a final tightening pressure hydrothermal gas treatment in overheated steam of the composite titanium nitride layers PVD, produced on AZ91D magnesium alloy. The proposed method resulted in an outstanding improvement of the performance properties, in particular resistance to corrosion and wear, yielding values that exceed those exhibited by commercially anodized alloys and austenitic stainless 316L steel. The developed hybrid method produces new, high-performance corrosion and wear resistant, lightweight magnesium base materials, suitable for heavy duty applications.

Curdlan hydrogel obtained after thermal gelling exhibits elasticity and high water-absorbing capacity. However, its modifications leading to the increase of biofunctionality usually alter its solubility and reduce mechanical parameters. Therefore, curdlan hydrogel was modified by deposition of polydopamine to improve its capacity to bind biologically active molecules with free amino groups. It exhibited the unchanged structure, mechanical properties and increased soaking capacity. Aminoglycoside antibiotic (gentamicin) as a model molecule was effectively immobilized to such modified curdlan via quinone moiety (but not amino groups) of polydopamine. Approximately 50 % of the immobilized drug was released following Fickian diffusion and inhibited the bacterial growth in matrix-surrounding medium in prolonged manner. The remaining drug amount was stably attached and prevented the hydrogel against bacterial adhesion even when all the mobile drug has been released. Therefore, polydopamine-modified curdlan hydrogel shows the potential for fabrication of functional materials for different purposes, including drug-loaded biomaterials., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Multilayers consisting of graphene oxide (GO) and α-Fe 2 O 3 thin layers were deposited on the ceramic substrates by the spray LbL (layer by layer) coating technique. Graphene oxide was prepared from graphite using the modified Hummers method. Obtained GO flakes reached up to 6 nanometers in thickness and 10 micrometers in lateral size. Iron oxide Fe 2 O 3 was obtained by the wet chemical method from FeCl 3 and NH 4 OH solution. Manufactured samples were deposited as 3 LbL (GO and Fe 2 O 3 layers deposited sequentially) and 6 LbL structures with GO as a bottom layer. Electrical measurements show the decrease of multilayer resistance after the introduction of the oxidizing NO 2 gas to the ambient air atmosphere. The concentration of NO 2 was changed from 1 ppm to 20 ppm. The samples changed their resistance even at temperatures close to room temperature, however, the sensitivity increased with temperature. Fe 2 O 3 is known as an n-type semiconductor, but the rGO/Fe 2 O 3 hybrid structure behaved similarly to rGO, which is p-type. Both chemisorbed O 2 and NO 2 act as electron traps decreasing the concentration of electrons and increasing the effective multilayer conductivity. An explanation of the observed variations of multilayer structure resistance also the possibility of heterojunctions formation was taken into account.

Plasma Electrolytic Oxidation (PEO) is as a promising technique to modify metal surfaces by application of oxide ceramic coatings with appropriate physical, chemical and biological characteristics. Therefore, objective of this research was to find the simplest settings, yet able to produce relevant bioactive implant surfaces layers on Ti implants by means of PEO. We show that an electrolyte containing potassium dihydrogen phosphate as a source of P and either calcium hydroxide or calcium formate as a source of Ca in combination with a chelating agent, ethylenediamine tetraacetic acid (EDTA), is suitable for PEO to deliver coatings with desired properties. We determined surface morphology, roughness, wettability, chemical and phase composition of titanium after the PEO process. To investigate biocompatibility and bacterial properties of the PEO oxide coatings we used microbial and cell culture tests. The electrolyte based on Ca(OH) 2 and EDTA promotes active crystallization of apatites after PEO processing of the Ti implants. The PEO layers can increase electrochemical corrosion resistance. The PEO can be potentially used for development of bioactive surfaces with increased support of eukaryotic cells while inhibiting attachment and growth of bacteria without use of antibacterial agents., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The paper is dedicated to the lifetime prolongation of the tools designed for deep-hole drilling. Among available methods, an ion implantation process was used to improve the durability of tungsten carbide (WC)-Co guide pads. Nitrogen fluencies of 3 × 10 17 cm -2 , 4 × 10 17 cm -2 and 5 × 10 17 cm -2 were applied, and scanning electron microscope (SEM) observations, energy dispersive spectroscopy (EDS) analyses, X-ray photoelectron spectroscopy (XPS) and Secondary Ion Mass Spectrometry (SIMS) measurements were performed for both nonimplanted and implanted tools. The durability tests of nonimplanted and the modified tools were performed in industrial conditions. The durability of implanted guide pads was above 2.5 times more than nonimplanted ones in the best case, presumably due to the presence of a carbon-rich layer and extremely hard tungsten nitrides. The achieved effect may be attributed to the dissociation of tungsten carbide phase and to the lubrication effect. The latter was due to the presence of pure carbon layer with a thickness of a few dozen nanometers. Notably, this layer was formed at a temperature of 200 °C, much smaller than in previously reported research, which makes the findings even more valuable from economic and environmental perspectives.

The main focus of this work was to establish a correlation between surface topography and chemistry and surface colonization by lactic acid bacteria. For this reason, we chose gold substrates with different surface architectures (i.e., smooth and nanorough) that were characterized by atomic force microscopy (AFM), electron scanning microscopy (SEM), and X-ray diffractometry (XRD). Moreover, to enhance biocompatibility, we modified gold substrates with polymeric monolayers, namely cationic dextran derivatives with different molar masses. The presence of those layers was confirmed by AFM, infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS). In order to determine the adhesion abilities of non-modified and modified gold surfaces, we tested three lactic acid bacteria (LAB) strains (i.e., Lactobacillus rhamnosus GG, Lactobacillus acidophilus, and Lactobacillus plantarum 299v). We have shown that surface roughness influences the surface colonization of bacteria, and the most significant impact on the growth was observed for the Lactobacillus rhamnosus GG strain. What is more, covering the gold surface with a molecular polymeric film by using the layer-by-layer (LbL) method allows additional changes in the bacterial growth, independently on the used strain. The well-being of the bacteria cells on tested surfaces was confirmed by using selective staining and fluorescence microscopy. Finally, we have determined the bacterial metabolic activity by measuring the amount of produced lactic acid regarding the growth conditions. The obtained results proved that the adhesion of bacteria to the metallic surface depends on the chemistry and topography of the surface, as well as the specific bacteria strain.

In a present paper, we demonstrate novel approach to form ceramic coatings with incorporated ZnO nanoparticles (NPs) on low modulus TiZrNb alloy with enhanced biocompatibility and antibacterial parameters. Plasma Electrolytic Oxidation (PEO) was used to integrate ZnO nanoparticles (average size 12-27 nm), mixed with Ca(H 2 PO 2 ) 2 aqueous solution into low modulus TiZrNb alloy surface. The TiZrNb alloys with integrated ZnO NPs successfully showed higher surface porosity and contact angle. XPS investigations showed presence of Ca ions and absence of phosphate ions in the PEO modified layer, what explains higher values of contact angle. Cell culture experiment (U2OS type) confirmed that the surface of as formed oxide-ZnO NPs demonstrated hydrophobic properties, what can affect primary cell attachment. Further investigations showed that Ca ions in the PEO coating stimulated proliferative activity of attached cells, resulting in competitive adhesion between cells and bacteria in clinical situation. Thus, high contact angle and integrated ZnO NPs prevent bacterial adhesion and considerably enhance the antibacterial property of TiZrNb alloys. A new anodic oxide coating with ZnO NPs could be successfully used for modification of low modulus alloys to decrease post-implantation complications.

High strength, excellent corrosion resistance, high biocompatibility, osseointegration ability, and low bacteria adhesion are critical properties of metal implants. Additionally, the implant surface plays a critical role as the cell and bacteria host, and the development of a simultaneously antibacterial and biocompatible implant is still a crucial challenge. Copper nanoparticles (CuNPs) could be a promising alternative to silver in antibacterial surface engineering due to low cell toxicity. In our study, we assessed the biocompatibility and antibacterial properties of a PEO (plasma electrolytic oxidation) coating incorporated with CuNPs (Cu nanoparticles). The structural and chemical parameters of the CuNP and PEO coating were studied with TEM/SEM (Transmission Electron Microscopy/Scanning Electron Microscopy), EDX (Energy-Dispersive X-ray Dpectroscopy), and XRD (X-ray Diffraction) methods. Cell toxicity and bacteria adhesion tests were used to prove the surface safety and antibacterial properties. We can conclude that PEO on a ZrNb alloy in Ca-P solution with CuNPs formed a stable ceramic layer incorporated with Cu nanoparticles. The new surface provided better osteoblast adhesion in all time-points compared with the nontreated metal and showed medium grade antibacterial activities. PEO at 450 V provided better antibacterial properties that are recommended for further investigation.

In order to determine the effect of different gelation temperatures (80 °C and 90 °C) on the structural arrangements in 1,3-β-d-glucan (curdlan) matrices, spectroscopic and microscopic approaches were chosen. Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) and Raman spectroscopy are well-established techniques that enable the identification of functional groups in organic molecules based on their vibration modes. X-ray photoelectron spectroscopy (XPS) is a quantitative analytical method utilized in the surface study, which provided information about the elemental and chemical composition with high surface sensitivity. Contact angle goniometer was applied to evaluate surface wettability and surface free energy of the matrices. In turn, the surface topography characterization was obtained with the use of atomic force microscopy (AFM) and scanning electron microscopy (SEM). Described techniques may facilitate the optimization, modification, and design of manufacturing processes (such as the temperature of gelation in the case of the studied 1,3-β-d-glucan) of the organic polysaccharide matrices so as to obtain biomaterials with desired characteristics and wide range of biomedical applications, e.g., entrapment of drugs or production of biomaterials for tissue regeneration. This study shows that the 1,3-β-d-glucan polymer sample gelled at 80 °C has a distinctly different structure than the matrix gelled at 90 °C.

Mo disulfide overlayers with the thickness exceeding 1.77 nm were obtained on Si substrates through mechanical exfoliation. The resulting Mo disulfide flakes were then analyzed ex situ using combination of Auger electron spectroscopy (AES), elastic-peak electron spectroscopy (EPES) and scanning electron microscopy (SEM) in order to characterize their surface chemical composition, electron transport phenomena and surface morphology. Prior to EPES measurements, the Mo disulfide surface was sputter-cleaned and amorphized by 3 kV argon ions, and the resulting S/Mo atomic ratio varied in the range 1.80-1.88, as found from AES measurements. The SEM images revealed single crystalline small-area (up to 15 μm in lateral size) Mo disulfide flakes having polygonal or near-triangular shapes. Such irregular-edged flakes exhibited high crystal quality and thickness uniformity. The inelastic mean free path (IMFP), characterizing electron transport, was evaluated from the relative EPES using Au reference material for electron energies E = 0.5-2 keV. Experimental IMFPs, λ , determined for the AES-measured surface compositions were approximated by the simple function λ = kE p , where k = 0.0289 and p = 0.946 were fitted parameters. Additionally, these IMFPs were compared with IMFPs resulting from the two methods: (i) present calculations based on the formalism of the Oswald et al. model; (ii) the predictive equation of Tanuma et al. (TPP-2M) for the measured Mo 0.293 S 0.551 C 0.156 surface composition (S/Mo = 1.88), and also for stoichiometric MoS 2 composition. The fitted function was found to be reasonably consistent with the measured, calculated and predicted IMFPs. We concluded that the measured IMFP value at 0.5 keV was only slightly affected by residual carbon contamination at the Mo disulfide surface.

Surface-enhanced Raman spectroscopy (SERS) substrates prepared by immobilizing silver cubic nanoparticles (Ag CNPs) on titanium dioxide nanotubes (TiO 2 NTs) were used for investigations of the "coffee ring" (CR) effect and its impact on spatial reproducibility of measured Raman signals in comparison with flat surfaces (Ti and Si) where the CR effect is usually significant. The immobilization of nanoparticles from drops, which is a very simple technique, usually does not permit a homogeneous distribution of deposited NPs because there is significant accumulation of the material at the boundary of the drying area. Our proposed SERS substrates effectively reduced the CR effect through the use of well-ordered nanostructures where a smaller number of Ag CNPs were transferred to the boundary region. It was not only the surface morphology that was important but also the physicochemical properties of TiO 2 NTs, such as wettability. The wettability of the prepared samples was determined by measuring the static water contact angle (WCA), and the chemical composition near the boundary of the drying area was studied using Auger electron spectroscopy. The morphology of the substrates obtained was characterized using scanning electron microscopy. Our studies showed that reducing the coffee ring effect increased the spatial reproducibility of the measured SERS signal in the area of the deposited CNPs. Therefore, the platforms obtained may be very useful in commercial SERS applications., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

The nitrogen doping of titanium dioxide nanotubes (TiO 2 NTs) was investigated as a result of well-controlled plasma nitriding of TiO 2 NTs at a low temperature. This way of nitrogen doping is proposed as an alternative to chemical/electrochemical methods. The plasma nitriding process was performed in a preparation chamber connected to an X-ray photoelectron spectroscopy (XPS) spectrometer, and the nitrogen-doped TiO 2 NTs were next investigated in situ by XPS in the same ultrahigh vacuum (UHV) system. The collected high-resolution (HR) XPS spectra of N 1s, Ti 2p, O 1s, C 1s, and valence band (VB) revealed the formation of chemical bonds between titanium, nitrogen, and oxygen atoms as substitutional or interstitial species. Moreover, the results provided a characterization of the electronic states of N-TiO 2 NTs generated by various plasma nitriding and annealing treatments. The VB XPS spectrum showed a reduction in the TiO 2 band gap of about 0.6 eV for optimal nitriding and heat-treated conditions. The TiO 2 NTs annealed at 450 or 650 °C in air (ex situ) and nitrided under UHV conditions were used as reference materials to check the formation of Ti-N bonds in the TiO 2 lattice with a well-defined structure (anatase or a mixture of anatase and rutile). Scanning electron microscopy microscopic observations of the received materials were used to evaluate the morphology of the TiO 2 NTs after each step of the nitriding and annealing treatments., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

In the present work, the magnetron sputtering technique was used to prepare new catalysts of formic acid electrooxidation based on TiO 2 nanotubes decorated with Pt (platinum), Pd (palladium) or Pd + Pt nanoparticles. TiO 2 nanotubes (TiO 2 NTs) with strictly defined geometry were produced by anodization of Ti foil and Ti mesh in a mixture of glycerol and water with ammonium fluoride electrolyte. The above mentioned catalytically active metal nanoparticles (NPs) were located mainly on the top of the TiO 2 NTs, forming 'rings' and agglomerates. A part of metal nanoparticles decorated also TiO 2 NTs walls, thus providing sufficient electronic conductivity for electron transportation between the metal nanoparticle rings and Ti current collector. The electrocatalytic activity of the TiO 2 NTs/Ti foil, decorated by Pt, Pd and/or Pd + Pt NPs was investigated by cyclic voltammetry (CV) and new Pd/TiO 2 NTs/Ti mesh catalyst was additionally tested in a direct formic acid fuel cell (DFAFC). The results so obtained were compared with commercial catalyst-Pd/Vulcan. CV tests have shown for carbon supported catalysts, that the activity of TiO 2 NTs decorated with Pd was considerably higher than that one decorated with Pt. Moreover, for TiO 2 NTs supported Pd catalyst specific activity (per mg of metal) was higher than that for well dispersed carbon supported commercial catalyst. The tests at DFAFC have revealed also that the maximum of specific power for 0.2 Pd/TiO 2 catalyst was 70% higher than that of the commercial one, Pd/Vulcan. Morphological features, and/or peculiarities, as well as surface composition of the resulting catalysts have been studied by scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and chemical surface analytical methods (X-ray photoelectron spectroscopy-XPS; Auger electron spectroscopy-AES)., Competing Interests: The authors declare no conflict of interest.

Plasma electrolytic oxidation (PEO) can provide an ideal surface for osteogenic cell attachment and proliferation with further successful osteointegration. However, the same surface is attractive for bacteria due to similar mechanisms of adhesion in prokaryotic and eukaryotic cells. This issue requires the application of additional surface treatments for effective prevention of postoperative infectious complications. In the present work, ZrNb alloy was treated in a Ca-P solution with Ag nanoparticles (AgNPs) for the development of a new oxide layer that hosted osteogenic cells and prevented bacterial adhesion. For the PEO, 0.5 M Ca(H 2 PO 2 ) 2 solution with 264 mg L -1 of round-shaped AgNPs was used. Scanning electron microscopy with energy-dispersive x-ray and x-ray photoelectron spectroscopy were used for morphology and chemical analysis of the obtained samples; the SBF immersion test, bacteria adhesion test, and osteoblast cell culture were used for biological investigation. PEO in a Ca-P bath with AgNPs provides the formation of a mesoporous oxide layer that supports osteoblast cell adhesion and proliferation. Additionally, the obtained surface with incorporated Ag prevents bacterial adhesion in the first 6 h after immersion in a pathogen suspension, which can be an effective approach to prevent infectious complications after implantation.

In this work we show that ordered freestanding titanium oxide nanotubes (TiO 2 NT) may be used as substrates for the simple and efficient immobilization of anisotropic plasmonic nanoparticles. This is important because anisotropic plasmonic nanostructures usually give greater spectral enhancement than spherical nanoparticles. The size of the pores in a layer of titanium oxide nanotubes can be easily fitted to the size of many silver plasmonic nanoparticles highly active in SERS (surface-enhanced Raman scattering) spectroscopy (for example, silver nanocubes with an edge length of ca. 45 nm), and hence, the plasmonic nanoparticles deposited can be strongly anchored in such a titanium oxide substrate. The tubular morphology of the TiO 2 substrate used allows a specific arrangement of the silver plasmonic nanoparticles that may create many so-called SERS hot spots. The SERS activity of a layer of cubic Ag nanoparticles (AgCNPs) deposited on a tubular TiO 2 substrate (AgCNPs@TiO 2 NT) is about eight times higher than that of the standard electrochemically nanostructured surface of a silver electrode (produced by oxidation reduction cycling). Furthermore, a super hydrophilic character of the TiO 2 nanotubes surface allows for a uniform distribution of AgCNPs, which are deposited from an aqueous suspension. The new AgCNPs@TiO 2 NT hybrid layer ensures a good reproducibility of SERS measurements and exhibits a higher temporal stability of the achievable total SERS enhancement factor-one that is far better than standard SERS silver substrates. To characterize the morphology and chemical composition of such evidently improved SERS platforms thus received, we applied microscopic techniques (SEM, and scanning transmission electron microscopy (STEM)) and surface analytical techniques (Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS)).