Rose Bengal Research Articles

Electrochemical synthesis of graphene rooted with prepared cerium vanadate liberating GO@CeVO4 composite for super-capacitive energy reservoir, furthered with photocatalytic degradation of Rose Bengal dye

In this discourse, exfoliated graphene is synthesized from graphite foil electrochemically and cerium vanadate was obtained hydrothermally. This research article discusses the fabrication of a series of composites based on exfoliated graphene supplemented with CeVO4 via hydrothermal route by maintaining the amount of CeVO4 as static and varying the proportion of graphene to obtain GO@CeVO4 or CG. The morphological and structural analysis of the synthesized outcomes were executed with relevant and advance characterization techniques. Electrochemical tests were conducted using CV, GCD and EIS. The best optimized composite CG3 exhibited a maximum specific capacitance of 1590 F/g at a scan rate of 5 mV/s in 1 M H2SO4. A remarkable energy density of 217.5 Wh/kg and power density of 252.4 W/kg were manifested by CG3 at a current density of 0.5 A/g. Additionally, magnificent cyclic stability with good retention, 98.04 % over 14,000 cycles were also observed for CG3. DFT is used as a supporting tool to get the band gap. Herein, photodegradation of Rose Bengal was also performed and CG3 manifested appreciable dye degradation of 90.7 % against Rose Bengal.

Ultra-fast photocatalytic degradation and seed germination of band gap tunable nickel doping ceria nanoparticles

Doping transition metal ions into cerium oxide (CeO2) results in interesting modifications to the material, including an increase in surface area, a high isoelectric point, biocompatibility, greater ionic conductivity, and catalytic activity. Herein, various concentrations (1–5%, 10% and 20%) of nickel (Ni) doped CeO2 nanoparticle have been made by a facile chemical process. Using a variety of cutting-edge analytical techniques, the structural, optical, and photocatalytic properties of undoped and varied concentrations (1–5%, 10%, and 20%) of Ni doped CeO2 nanoparticles have been investigated. Pure cubic fluorite structure with average crystallite sizes in the region of 12–15 nm was determined by X-ray diffraction (XRD) investigation. Transmission electron microscopy (TEM), which revealed highly homogeneous hexagonal shape of the particles with average size of 15 nm, was also used to determine microstructural information. According to the optical absorption, the band gaps of Ni doped and undoped CeO2 nanoparticles were found to be 2.96 eV and 1.95 eV, respectively. When exposed to sunlight, the narrow band gap Ni doped CeO2 nanoparticles worked as an active visible light catalyst to remove the dyes Rose Bengal (RB) and Direct Yellow (DY). The best photodegradation efficiencies for RB and DY dyes were found about 93% and 97%, respectively, using the 5% Ni-doped CeO2 catalyst. The apparent rate constant values of 0.039 for RB and 0.040 min−1 were attained for DY. As well, the treated, untreated dye solution and control solutions were utilized to assess the toxicity of commercially accessible Vigna Radiata seeds. In this study exhibits percentages of length and germination increased by 30–35% when compared to dye pollutant solution. The Ni doped CeO2 can provide a substantial alternative for current industrial waste management because of its quick photocatalytic activity and remarkable seed germination results.

Surface conditioning of PEEK post using Nd: YVO4 laser, photodynamic therapy, and sulfuric acid on the pushout bond strength to canal dentin

AimTo assess the push-out bond strength (PBS) of polyetheretherketone (PEEK) post-to-root dentin using post-surface conditioners i.e., Neodymium-doped yttrium orthovanadate (Nd: YVO4) and Riboflavin (RF) and Rose Bengal (RB) mediated photodynamic therapy (PDT) compared to sulfuric acid (SA). Materials and MethodsDecoronation of forty human single-rooted premolar teeth was performed. Followed by chamber opening, working length (WL) was established at 15 mm. Root canal preparation was completed using ProTaper Ni-Ti rotary system till F3 finishing file along with root canal disinfection. The canals were dried with paper cones followed by obturation using gutta-percha (GP) and AH sealer. Post space was prepared by drilling out 11 mm of GP using a Gates Glidden drill #3. PEEK posts were fabricated using the CAD-CAM system and then randomly allocated into 4 groups based on the post-surface conditioning (n = 10). Group 1: SA, group 2: PDT RF, group 3: PDT RB, and group 4: Nd: YVO4 laser. The PEEK post was then cemented in their respective canal. PBS and failure mode assessment were performed using a universal testing machine and stereomicroscope at 40x magnification. The SBS data set was subjected to a one-way analysis of variance (ANOVA) and Tukey's Post Hoc test at a significance level of 0.05. ResultsThe samples in group 4 (Nd: YVO4 laser) coronal third (7.99±0.24 MPa) demonstrated the highest PBS. The apical third of samples in group 1 PEEK post surface conditioned with SA (5.15± 0.52 MPa) exhibited the minimum values of PBS. Intergroup comparison analysis showed that samples in group 1 (SA), group 2 (RF activated by PDT), group 3 (RB activated by PDT), and group 4 (Nd: YVO4 laser) demonstrated comparable outcomes of bond scores (p>0.05) ConclusionNeodymium-doped yttrium orthovanadate (Nd: YVO4) and riboflavin and Rose bengal activated by photodynamic therapy (PDT) have been investigated as potential alternatives for the surface conditioning of PEEK (polyetheretherketone) posts.

UV-Blocking and Light-Responsive Poly (ϵ-Caprolactone)/ZIF-8 Multifunctional Composite Films for Efficient Antibacterial Activities.

Antibacterial photodynamic therapy (APDT) has received considerable attention owing to its superiority. ZIF-8 was used to address the poor stability of the photosensitizer Rose Bengal (RB) encapsulation to synthesize RB@ZIF-8 NPs, which were doped into a composite film with poly (ϵ-caprolactone) (PCL) and polyvinyl alcohol-quaternary ammonium chitosan (PVA-QCS) as substrates to form composite films (PQZ). The composite films exhibited excellent photodynamic sterilization and good resistance to bacterial adhesion. The tensile strength of the film increased to 43.4 MPa, which was approximately 1.8 times that of the PCL film. With the addition of SiO2 and RB@ZIF-8 NPs, the film exhibited water repellency and UV-blocking properties. RAW264.7 cells were selected using the MTT method to confirm that the composite films had excellent biocompatibility and had no significant inhibitory effect on cell growth and reproduction. PQZ multifunctional composite films show potential as novel APDT antimicrobial materials for food packaging.

Visible light-induced metal-free synthesis of quinoxalines
 using Rose Bengal as a photocatalyst

Visible light-induced metal-free synthesis of quinoxalines
 using Rose Bengal as a photocatalyst

Staphylococcus aureus from Atopic Dermatitis Patients: Its Genetic Structure and Susceptibility to Phototreatment.

We characterized the population of Staphylococcus aureus from patients with atopic dermatitis (AD) in terms of (i) genetic diversity, (ii) presence and functionality of genes encoding important virulence factors: staphylococcal enterotoxins (sea, seb, sec, sed), toxic shock syndrome 1 toxin (tsst-1), and Panton-Valentine leukocidin (lukS/lukF-PV) by spa typing, PCR, drug resistance profile determination, and Western blot. We then subjected the studied population of S. aureus to photoinactivation based on a light-activated compound called rose bengal (RB) to verify photoinactivation as an approach to effectively kill toxin-producing S. aureus. We have obtained 43 different spa types that can be grouped into 12 clusters, indicating for the first-time clonal complex (CC) 7 as the most widespread. A total of 65% of the tested isolates had at least one gene encoding the tested virulence factor, but their distribution differed between the group of children and adults, and between patients with AD and the control group without atopy. We detected a 3.5% frequency of methicillin-resistant strains (MRSA) and no other multidrug resistance. Despite genetic diversity and production of various toxins, all isolates tested were effectively photoinactivated (bacterial cell viability reduction ≥ 3 log10 units) under safe conditions for the human keratinocyte cell line, which indicates that photoinactivation can be a good option in skin decolonization. IMPORTANCE Staphylococcus aureus massively colonizes the skin of patients with atopic dermatitis (AD). It is worth noting that the frequency of detection of multidrug-resistant S. aureus (MRSA) in AD patients is higher than the healthy population, which makes treatment much more difficult. Information about the specific genetic background of S. aureus accompanying and/or causing exacerbations of AD is of great importance from the point of view of epidemiological investigations and the development of possible treatment options.

In vitro study of Nigella sativa and thymoquinone activity on endothelial activation and monocyte adhesion.

Thymoquinone (TQ) is one of the bioactive compounds in Nigella sativa (NS). Also known as black seeds/cumin, it has been postulated to possess anti-atherogenic properties. However, research on the effects of NS oil (NSO) and TQ on atherogenesis remain scarce. The aim of this study is to determine gene and protein expression of Intercellular Adhesion Molecule-1 (ICAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1), and Endothelial-eukocyte adhesion molecule (E-selectin) in Human Coronary Artery Endothelial Cells (HCAECs). HCAECs were stimulated for 24 hours (h) with 200 µg/ml of Lipopolysaccharides (LPS) and different concentrations of NSO (55, 110, 220, 440 µg/ml) or TQ (4.5, 9.0, 18.0, 36.0 µm). The effects of NSO and TQ on gene and protein expressions were measured using multiplex gene assay and ELISA assay, respectively. Rose Bengal assay was used to analyse monocyte binding activity. NSO and TQ significantly reduced ICAM-1 and VCAM-1 gene and protein expressions. TQ showed significant reduction activity of the biomarkers in dose dependent manner. HCAECs pre-treated with NSO and TQ for 24 h significantly lowered monocytes adherence compared to non-treated HCAECs. NSO and TQ supplementation have anti-atherogenic properties and inhibit monocytes' adherence to HCAECs via down-regulation of ICAM-1 expression. NSO could potentially be incorporated in standard treatment regimens to prevent atherosclerosis and its related complications.

Cytotoxicity Evaluation of Photosensitizer-Conjugated Hexagonal Upconverting Nanoparticles.

In this report, we synthesized hexagonal NaYF4:Yb,Er upconverting nanoparticles (UCNPs) of 171 nm in size with a narrow particle size distribution. To address their colloidal stabi-lity in aqueous media and to incorporate a photosensitizer that can produce reactive singlet oxygen (1O2) to kill tumor cells, UCNPs were conjugated with 6-bromohexanoic acid-functionalized Rose Bengal (RB) and coated with PEG-alendronate (PEG-Ale). The particles were thoroughly characterized by transmission electron microscopy, dynamic light scattering, ATR FTIR, X-ray photoelectron spectroscopy, thermogravimetric analysis, and spectrofluorometry, and 1O2 formation was detected using a 9,10-diphenylanthracene spectrophotometric probe. Cytotoxicity determination on rat mesenchymal stem cells by using the MTT assay showed that neutralization of the large positive surface charge of neat UCNPs with PEG-Ale and the bound RB sensitizer significantly reduced the concentration-dependent cytotoxicity. The presented strategy shows great potential for the use of these particles as a novel agent for the photodynamic therapy of tumors.

Comparison of the Polymerase Chain Reaction Method with Serological Tests in the Diagnosis of Human Brucellosis

Background: Brucellosis is a zoonotic disease with different clinical symptoms. Its early diagnosis is essential to prevent severe complications. Due to the limitations of serological diagnostic methods, the polymerase chain reaction (PCR) method has become important in the diagnosis of the disease. Objectives: Our study aimed to evaluate the PCR method in patients with suspected brucellosis and compare it with serological tests. Methods: This cross-sectional study was performed on 90 febrile patients with clinical features of brucellosis who were examined by an infectious disease specialist. A total of 90 serum samples were collected from the suspected brucellosis patients admitted to the hospital and were analyzed by serological (Rose Bengal) and PCR tests. Then, each method's results were recorded and compared with each other. Results: According to serological test results, 45 samples were negative, and 45 were positive. Then, among the serology-positive patients, all had positive PCR results. However, 40 out of 45 patients had a positive PCR test in serology-negative patients. According to this study, the sensitivity of PCR in diagnosing human brucellosis with the serology-positive test is 100%, and with the negative serology test is 88.9%. Therefore, the sensitivity of PCR is higher than that of serology tests in patients, which was 50% in this study. Conclusions: The PCR test can be a valuable diagnostic method for patients with negative serologic test results.

Management of bovine brucellosis in organized dairy herds through the identification of risk factors: A cross-sectional study from Karnataka, India.

Brucellosis is an infectious disease caused by Brucella species. This study aimed to identify the risk factors associated with bovine brucellosis seropositivity in organized dairy farms to control the disease in unvaccinated adult bovine herds in Karnataka, India. In total, 3610 samples (3221 cattle and 389 buffaloes) were subjected to parallel testing using the Rose Bengal plate test and protein G-based enzyme-linked immunosorbent assay, followed by analyses of animal- and farm-level epidemiological datasets to identify the risk factors. The apparent brucellosis prevalence at the animal level was higher in buffaloes (8.2%, 95% confidence interval [CI] = 5.9-11.4) than in cattle (6.1%, 95% CI = 5.3-7.0). In a multivariable logistic model, animals calved 3-5 times (odds ratio [OR] = 2.22, 95% CI = 1.50-3.1, reference [ref]: animals calved <2 times); animals with a history of abortion (OR = 54.73, 95% CI = 33.66-89.02), repeat breeding (OR = 19.46, 95% CI = 11.72-32.25), and placental retention (OR = 13.94, 95% CI = 4.92-39.42, ref: no clinical signs); and dogs on farms (OR = 2.55, 95% CI = 1.48-4.40, ref: absence of dogs); disposal of aborted fetus in open fields (OR = 4.97, 95% CI = 1.93-12.84) and water bodies (OR = 2.22, 95% CI = 1.50-3.1, ref: buried); purchase of animals from other farms (OR = 6.46, 95% CI = 1.01-41.67, ref: government farms); hand milking (OR = 1.98, 95% CI = 1.02-10.0, ref: machine milking); and use of monthly veterinary services (OR = 3.45, 95% CI = 1.28-9.29, ref: weekly services) were considered significant risk factors for brucellosis in organized bovine herds (p < 0.01). The study identified that the animals calved 3-5 times or with a history of abortion/repeat breeding/placental retention, and disposal of aborted fetus in open fields/water bodies as the potential risk factors for bovine brucellosis. These risk factors should be controlled through the implementation of best practices to reduce the brucellosis burden in bovine farms.

Seroprevalence and Associated Risk Factors of Brucellosis Among Human Population in Duhok City, Iraq.

Brucellosis is a zoonotic disease that contributes to severe global health and economic issues. In this study, the Rose Bengal Test (RBT), a crucial diagnostic tool for brucellosis in Duhok city, was evaluated in order to offer updated epidemiological data on this disease. A total of 339 patients suffered from fever and seeking medical attention in the private medical health center in Duhok city, Iraq, were enrolled after taking ethical approval from committee at Faculty of Sciences, University of Zakho and a verbal consent from each enrolled patient for using his/her blood and data. The blood specimens were tested for Brucella spp. Antibodies using the RBT and blood cultures, followed by spp. determination. A questionnaire form was designed to detect the associated risk factors. Prevalence of brucellosis was 12.6% among participants with a probable diagnosis and 10.3% among those with a confirmed diagnosis (positive blood culture). Most of the positive cases were between the ages of 20 to 40 years. A highly significant (P < 0.0001) association was found between brucellosis with both consuming raw milk and having contact with cattle. The most common species identified were Brucella melitensis (57.1%) and Brucella abortus (42.7%). Brucellosis is a significant cause of fever in the current study and can be detected using the RBT. Human brucellosis can be reduced by minimizing the chances of contact with cattle and consuming boiled or pasteurized milk.

Seroprevalence and risk factors for brucellosis and leptospirosis in swine from rural communities of Argentina

Objectives. To determine the seroprevalence of brucellosis and leptospirosis in pigs reared on small-scale farms in rural areas of the district of Tandil, Buenos Aires Province, Argentina; to analyse the associated risk factors; to describe the prevalent Leptospira spp. serogroups; and to determine the spatial distribution of both diseases. Materials and methods. A total of 340 serum samples were obtained. Buffer Plate Agglutination Test, Rose Bengal Test, and Fluorescence Polarisation Assay were used to detect antibodies against Brucella spp. Microscopic Agglutination Test was applied for serological diagnosis of leptospirosis. Statistical methods were used to evaluate the factors associated with the infections. Results. Seroprevalence of 0% and 22.6% was observed for brucellosis and leptospirosis, respectively. The most prevalent Leptospira serogroups identified were Canicola, Ballum, Icterohaemorrhagiae and Pomona. The main risk factors associated with leptospirosis infection were farms with a higher number of pigs and the presence of horses and wild boars near or within the farms. The use of milling by-products of cereal grains as animal feed and the presence of weaning cages were also associated. A relevant spatial cluster of seropositivity to Leptospira spp. was identified in a low-altitude area. Conclusions. Our results suggest that brucellosis is probably controlled, but Leptospira spp. are present in the farming systems under study. Knowledge of brucellosis and leptospirosis seroprevalence, spatial distribution and associated risk factors can be useful for the prevention and control of endemic zoonotic diseases in the region.

Prevalence of hemorrhagic septicemia in dromedary camel (Camelus dromedarius) of some selected farms at Benadir region, Somalia

Pasteurellosis (Hemorrhagic septicemia) is a common respiratory Disease of camel that is an acutely fatal disease caused by Pasteurella multocida type A or several serotypes of Mannheimia hemolytic, which also affect other animals. The disease had shown to spread between animals, across herds, and to humans. Meaning that the disease is Zoonosis. The study aimed at the establishment of seroprevalence of Pasteurellosis in some selected Districts of camel rearing in the Benadir Region. It was a cross-sectional study, where the study population was purposively chosen to consist of animals taken within three sub-Districts of Benadir Region, namely Sub-District (Daynile Township), Sub-District (Yaaqshid) Sub-District (kaxda). This was because they normally handle many camels in a day, thus making it easy for the investigator to access the required number conveniently; it was also assumed that data collected from these for-slaughter camels was representative of the situation in the sub-District/county. A total of one hundred and sixty camels were tested using four serological tests: Rose Bengal Plate Test (RBPT),) and Complex Fixation Test (CFT). The serological tests were purposively chosen to increase the chances of picking positive cases and also to compare their sensitivities, with respect to camel serum, since they were originally meant for use on bovine serum. Blood samples (15 ml) were collected for serum harvesting from the jugular veins of the animals as they were waiting to be examined. Rose Bengal plate test and CFT were run at a laboratory within the department of Veterinary Medicine, University of Horsed, 21 October campus; serum samples having been transported in a cool box. On average, out of an overall total of 300 serum samples tested, 180 samples were selected as sample procedures and were given eleven (11) positive results, amounting to a prevalence of 6.67%. For the three Districts, respective prevalence (averaged from the two (2) serological tests run) were: 7% (3/50) for Yaqshiid; 8% (3/60) for Deyniile, and 10% (3/70) for Kaxda. When sensitivities of the two (2) serological tests were compared, there was no significant difference between them, with respect to the picking of positive cases (p=0.05), The study has demonstrated presence of Pasterolosis in camels in the Benadir Region and the authors are, recommending the usage of RBPT and CFT as a screening test since they are cheap, quick, and easy to carry-out. Any of the other three involving tests can then be used if one wants to establish respective titers. Therefore, further detailed investigation needs to be conducted so as to understand specific etiological agents causing pasteurellosis in camels and can be instituted to optimize the benefit obtained from the camel sector.

COMPARISON OF CLINICAL, LABORATORY FINDINGS AND COMPLICATIONS IN BACTERIEMIC AND NONBACTERIEMIC BRUCELLOSIS: A SINGLE CENTER EXPERIENCE

Objective: Brucellosis is a systemic zoonosis that affects various organs or body systems and can mimic many diseases. Symptoms can range from acute febrile illness to chronic clinical manifestations with severe complications. In our study, we investigated the relationship between bacteremia and clinical and laboratory findings, and complications in patients with brucellosis.&#x0D; Material and Methods: Two hundred and twenty-three patients diagnosed with brucellosis between 2005 and 2020 in the department of infectious diseases and clinical microbiology of a tertiary care university hospital were included in the study. Rose Bengal test, Brucella standard tube agglutination test and culture (blood and/or bone marrow culture) were used for the diagnosis of brucellosis. The patients were divided into two groups according to their bacteremia status. Patients with positive culture were identified as bacteremia, and patients with negative culture were identified as non-bacteriemic.&#x0D; &#x0D; Results: A total of 223 patients were included in the study, of which 142 (63.7%) were male. While weight loss, fever and hematological complications were higher in bacteremia cases (p=0.001, p

Neutral BODIPY derivatives as photosensitizers

A series of 2,6-dibromo-, 2,6-diiodo-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene, together with the 4,4-dicyano analogs were synthesized. The photostability of these BODIPY derivatives and their efficiencies in generating singlet oxygen species were determined. Among these, 2,6-dibromo-4,4-dicyano-4-bora-3a,4a-diaza-s-indacene (BODIPY 6) was found to be similarly photostable as Rose Bengal, while 2,6-diiodo-8-iodomethyl-1,3,5,7-tetramethyl-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY 10) and 1,3,5,7,8-pentamethyl-2,6-diiodo-4,4-dicyano-4-bora-3a,4a-diaza-s-indacene (BODIPY 5) were found to be the least stable. For the ability to generate singlet oxygen species, 2,6-dibromo- (BODIPY 3) and 2,6-diiodo-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY 2) were found to be more efficient than Rose Bengal, while BODIPY 10 and 1,3,5,7,8-pentamethyl-2,6-diiodo-4,4-dicyano-4-bora-3a,4a-diaza-s-indacene (BODIPY 5) were quite poor photosensitizers. When Bacillus subtilus cultures were supplemented with the photosensitizers and exposed to light, it was found that the presence of a positive charge in the photosensitizers was essential in order for them to be effective bacterialcidal agents.

Visible-Light-Reactive Single-Chain Nanoparticles.

We introduce a single-chain nanoparticle (SCNP) system capable of catalyzing the photooxidation of nonpolar alkenes up to three times more efficiently than an equivalent small-molecule photosensitizer at an identical concentration. Specifically, we construct a polymer chain constituted of poly(ethylene glycol) methyl ether methacrylate and glycidyl methacrylate which we compact via multifunctional thiol-epoxide ligation and functionalize with Rose Bengal (RB) in a one pot reaction, affording SCNPs with a hydrophilic shell and hydrophobic photocatalytic regions. Photooxidation of the internal alkene in oleic acid proceeds under green light. RB confined within the SCNP is three times more effective for nonpolar alkenes than free RB in solution, which we hypothesize is due to the spatial proximity of the photosensitizing units to the substrate in the hydrophobic region. Our approach demonstrates that SCNP based catalysts can afford enhanced photocatalysis via confinement effects in a homogeneous reaction environment.

Einzelkettennanopartikel mit Reaktivität im sichtbaren Lichtspektrum

AbstractWir stellen ein Einzelkettennanopartikel (SCNP)‐System vor, welches bei identischer Konzentration die Photooxidation unpolarer Alkene bis zu dreimal effizienter katalysieren kann als ein äquivalenter niedermolekularer Photosensibilisator. Konkret haben wir SCNPs basierend auf Poly(ethylenglykol)methylethermethacrylat und Glycidylmethacrylat entwickelt, welches wir über multifunktionelle Thiol‐Epoxid‐Verknüpfungen in Kombination mit der Funktionalisierung mit Bengalrosa (RB) in einer Eintopfreaktion falten. Die SCNPs weisen sowohl eine hydrophile Hülle als auch hydrophobe photokatalytische Regionen auf. Die Photooxidation des innenliegenden Alkens der Ölsäure verläuft unter Einstrahlung von grünem Licht. Kovalent an die SCNPs gebundenes RB ist dreimal sensitiver gegenüber unpolaren Alkene als freies RB in Lösung. Dies ist unserer Hypothese nach auf die räumliche Nähe der photosensibilisierenden Gruppen zum Substrat in der hydrophoben Region zurückzuführen. Unser Ansatz zeigt, dass SCNP‐basierte Katalysatoren eine verbesserte Photokatalyse durch Einschränkungseffekte (confinement effects) in einer homogenen Reaktionsumgebung ermöglichen können.

Photochemically induced thalamus infarction impairs cognition in a mouse model

BackgroundSmall subcortical infarcts account for up to 25% of ischaemic strokes. Thalamus is one of the subcortical structures that commonly manifest with lacunar infarcts on MRI of the brain. Studies...

Tandem photo-crosslinking/sol–gel reaction for the green synthesis of morphology-alterable, redox-responsive silica particles

Silica-based nanoparticles have been employed in versatile biomedical applications during the past decades and one of the important research focuses has been the synthesis of biothiol-degradable redox responsive silica to resolve the toxicity concerns of bioaccumulation. In the conventional sol-gel approach, the use of acidic or basic catalyst was always necessary. Solvent, heating, and templates were often applied. Besides, multi-step synthetic procedures were also frequently required to obtain the desired silane with disulfide-linkage for the following synthesis. We developed a facile and green photo-crosslinking coupled sol–gel reaction to produce disulfide-linked redox-responsive silica particles in water at room temperature. The reaction was template-free and initiated by visible light irradiation of photosensitizer (rose bengal). The particle size was tunable by adjusting the concentration of silica precursors, photosensitizer, and irradiation time of LED. The morphologies of the silica nanoparticles can be dramatically altered by simply changing the thiolated silica precursors. The kinetics of the silica precursors during the hydrolysis and photocrosslinking reactions played a critical role. Rose bengal served as a photosensitizer for silica nanoparticle formation and a photodynamic drug. The encapsulated rose bengal remained effective to generate singlet oxygen with superior performance than that of free ones. The disulfide bonds created in the silica matrix responded to reducing reagents, resulting in controllable self-disassembly. Additionally, we found that the presence of magnesium salts affected the rate of the photocrosslinking reaction, forming rod-shaped particles. The current results provide insights for future stimuli-responsive silica-based material development.

Serological survey of Brucella infection in horses in Kano Metropolis, Kano State, Nigeria

Brucellosis is a zoonotic bacterial disease with worldwide distribution. A cross-sectional study was conducted to determine the serological prevalence of brucellosis in horses within Kano Metropolis. A total of 328 serum samples were collected for the study. Modified Rose Bengal Plate Test (mRBPT) was conducted on all the samples while the Serum Agglutination Test with EDTA (SAT-EDTA) was conducted on the mRBPT-positive samples. The prevalence of brucellosis in horses within the Kano metropolis was found to be 24.09 % (79/328) and 11.89 % (39/328) with mRBPT and SAT-EDTA respectively. There was no statistically significant difference in the seropositivity by the tests used. From the study, 37 (23.27%) out of the 159 mares were seropositive for Brucella antibodies using mRBPT while 16 (43.24 %) were positive using SAT-EDTA. Similarly, of the 169 stallions, 38 (22.4 %) were positive using mRBPT and of these 22(57.89 %) were further positive by using SAT-EDTA. Unlike the age and use of the horses; location, sex, and breed were not significantly associated with the seroprevalence rate obtained in the study using mRBPT P&lt;0.05. This study showed that Brucella antibodies were circulating in the horses in the study area. Further study is recommended to determine the Brucella species circulating in these horses, particularly that brucellosis is zoonotic with serious public health significance. There is also the need to examine the horse owners and grooms for possible Brucella antibodies because equine brucellosis has serious public health significance.