Study of Electrical and Dielectric Behaviors of Copper-Doped Zinc Oxide Ceramic Prepared by Spark Plasma Sintering for Electronic Device Applications.

In this study, Cu-doped ZnO aerogel nanoparticles with a 4% copper concentration (Cu4ZO) were synthesized using a sol-gel method, followed by supercritical drying and heat treatment. The subsequent fabrication of Cu4ZO ceramics through Spark Plasma Sintering (SPS) was characterized by X-ray diffraction (XRD), field-emission gun scanning electron microscopy (FE-SEM) equipped with EDS, and impedance spectroscopy (IS) across a frequency range of 100 Hz to 1 MHz and temperatures from 270 K to 370 K. The SPS-Cu4ZO sample exhibited a hexagonal wurtzite structure with an average crystallite size of approximately 229 ± 10 nm, showcasing a compact structure with discernible pores. The EDS spectrum indicates the presence of the base elements zinc and oxygen with copper like the dopant element. Remarkably, the material displayed distinct electrical properties, featuring high activation energy values of about 0.269 ± 0.021 eV. Complex impedance spectroscopy revealed the impact of temperature on electrical relaxation phenomena, with the Nyquist plot indicating semicircular arc patterns associated with grain boundaries. As temperature increased, a noticeable reduction in the radius of these arcs occurred, coupled with a shift in their center points toward the axis center, suggesting a non-Debye-type relaxation mechanism. Dielectric analyses revealed a temperature-driven evolution of losses, emphasizing the material's conductivity impact. Non-Debye-type behavior, linked to ion diffusion, sheds light on charge storage dynamics. These insights advance potential applications in electronic devices and energy storage.

Influence of the Addition of Zinc, Strontium, or Magnesium Oxides to the Bioglass 45S5 Network on Electrical Behavior.

45S5 Bioglass has been widely used in regenerative medicine due to its ability to dissolve when inserted into the body. Its typically amorphous structure allows for an ideal dissolution rate for the formation of the hydroxyapatite layer, which is important for the development of new bone. This bioactive capacity can also be controlled by adding other oxides (e.g., SrO, ZnO, and MgO) to the 45S5 Bioglass network or by storing electrical charge. Ions such as zinc, magnesium, and strontium allow for specific biological responses to be added, such as antibacterial action and the ability to increase the rate of osteoblast proliferation. The charge storage capacity allows for a higher rate of bioactivity to be achieved, allowing for faster attachment to the host bone, decreasing the patient's recovery time. Therefore, it is necessary to understand the variation in the structure of the bioglass with regard to the amount of non-bridging oxygens (NBOs), which is important for the bioactivity rate not to be compromised, and also its influence on the electrical behavior relevant to its potential as electrical charge storage. Thus, several bioactive glass compositions were synthesized based on the 45S5 Bioglass formulation with the addition of various concentrations (0.25, 0.5, 1, and 2, mol%) of zinc, strontium, or magnesium oxides. The influence of the insertion of these oxides on the network was evaluated by studying the amount of NBOs using Raman spectroscopy and their implication on the electrical behavior. Electrical characterization was performed in ac (alternating current) and dc (direct current) regimes.

Hemodialysis vascular access coordinator: Three-level model for access management.

Management of vascular access is a challenge for the dialysis team, particularly to keep the arteriovenous access working. The vascular access coordinator can positively contribute to increase the number of arteriovenous fistulas and reduce central venous catheters. In this article, we introduce a new approach to vascular access management centered on (the results of setting up) the role of vascular access coordinator. We described the three-level model (3Level_M) for vascular access management organized in three levels: vascular access nurse manager, vascular access coordinator, and vascular access consultant. We defined the instrumental skills and training required to be developed by each element and clarify the articulation between the model and all members of the dialysis team related to vascular access.

Cobalt Ferrite Synthesized Using a Biogenic Sol-Gel Method for Biomedical Applications.

Cancer is one of the leading causes of death worldwide. Conventional treatments such as surgery, chemotherapy, and radiotherapy have limitations and severe side effects. Magnetic hyperthermia (MH) is an alternative method that can be used alone or in conjunction with chemotherapy or radiotherapy to treat cancer. Cobalt ferrite particles were synthesized using an innovative biogenic sol-gel method with powder of coconut water (PCW). The obtained powders were subjected to heat treatments between 500 °C and 1100 °C. Subsequently, they were characterized by thermal, structural, magnetic, and cytotoxic analyses to assess their suitability for MH applications. Through X-ray diffraction and Raman spectroscopy, it was possible to confirm the presence of the pure phase of CoFe2O4 in the sample treated at 1100 °C, exhibiting a saturation magnetization of 84 emu/g at 300 K and an average grain size of 542 nm. Furthermore, the sample treated at 1100 °C showed a specific absorption rate (SAR) of 3.91 W/g, and at concentrations equal to or below 5 mg/mL, is non-cytotoxic, being the most suitable for biomedical applications.

Exploring bismuth-doped polycrystalline ceramic Ba0.75Bi0.25Ni0.7Mn0.3O3: synthesis, structure, and electrical properties for advanced electronic applications.

This manuscript investigates the structural and electrical properties of a Ba0.75Bi0.25Ni0.7Mn0.3O3 (BNMO) perovskite compound synthesized through the sol-gel method. The orthorhombic crystal structure of the sample is confirmed by X-ray diffraction analysis. The electrical conductivity of BNMO is found to increase with frequency, indicating the presence of local charge carriers. The AC electrical conductivity follows Jonscher's equation, exhibiting a plateau at low frequencies and a power-law behavior at high frequencies. The activation energy for conduction is determined to be 0.654 eV. Impedance spectroscopy reveals the presence of grain and grain boundary contributions, which are modeled using an R-CPE combination circuit. Analysis of the electrical modulus demonstrates non-Debye type relaxation and indicates the presence of charge carrier hopping between Mn2+ and Mn3+ ions. The activation energy obtained from the relaxation peaks of the modulus is found to be 0.674 eV. The dielectric constant exhibits high values that increase with temperature. This observation suggests that the capacitance behavior holds promising potential for energy storage applications, making it a suitable candidate for various technological uses.

Potassium Ferrite for Biomedical Applications.

Ferrites have been widely studied for their use in the biomedical area, mostly due to their magnetic properties, which gives them the potential to be used in diagnostics, drug delivery, and in treatment with magnetic hyperthermia, for example. In this work, KFeO2 particles were synthesized with a proteic sol-gel method using powdered coconut water as a precursor; this method is based on the principles of green chemistry. To improve its properties, the base powder obtained was subjected to multiple heat treatments at temperatures between 350 and 1300 °C. The samples obtained underwent structural, morphological, biocompatibility, and magnetic characterization. The results show that upon raising the heat treatment temperature, not only is the wanted phase detected, but also the secondary phases. To overcome these secondary phases, several different heat treatments were carried out. Using scanning electron microscopy, grains in the micrometric range were observed. Saturation magnetizations between 15.5 and 24.1 emu/g were observed for the samples containing KFeO2 with an applied field of 50 kOe at 300 K. From cellular compatibility (cytotoxicity) assays, for concentrations up to 5 mg/mL, only the samples treated at 350 °C were cytotoxic. However, the samples containing KFeO2, while being biocompatible, had low specific absorption rates (1.55-5.76 W/g).

Molecular Detection of Metronidazole and Tetracycline Resistance Genes in Helicobacter pylori-Like Positive Gastric Samples from Pigs.

Antimicrobial resistance is a major public health concern. The aim of this study was to assess the presence of antibiotic resistance genes, previously reported in Helicobacter pylori, in gastric samples of 36 pigs, in which DNA of H. pylori-like organisms had been detected. Based on PCR and sequencing analysis, two samples were positive for the 16S rRNA mutation gene, conferring tetracycline resistance, and one sample was positive for the frxA gene with a single nucleotide polymorphism, conferring metronidazole resistance. All three amplicons showed the highest homology with H. pylori-associated antibiotic resistance gene sequences. These findings indicate that acquired antimicrobial resistance may occur in H. pylori-like organisms associated with pigs.

How to choose the appropriate cannulation technique for vascular access in hemodialysis patients.

The cannulation technique is important for the survival of the arteriovenous access. Choosing the appropriate technique is a complex decision. Such choice must be customized to patients, considering their characteristics, the type of arteriovenous access and the experience of the hemodialysis team. We describe seven items that can help nurses to identify the appropriate cannulation technique: type of arteriovenous access; drainage vein; hygienic self-care profile; experience of the nursing staff in the cannulation technique and nurse-to-patient ratio; hemodialysis treatment method; patient's condition; and patient's decision. Such items can help nurses in decision-making on the "ideal" cannulation technique for each patient.

The Barretos Cancer Hospital Animal Facility: Implementation and Results of a Dedicated Platform for Preclinical Oncology Models.

The Barretos Cancer Hospital Animal Facility (BCHAF) is a unique facility in Brazil exclusively dedicated to working with animal models for cancer research. In this article, we briefly present our modern facility and the main experiments performed, focusing on mutant strains of mice (PTCH-knockout and ApcMin mice), xenograft models, and patient-derived xenografts (PDXs). Our results show the progress and challenges in establishing these models and the need for having an appropriate representation of our cancer population to better understand tumor biology and to identify cancer biomarkers, which could be putatively targeted, allowing for personalized therapy.

Perception and Knowledge of Portuguese Veterinarians about the Zoonotic Transmission of Helicobacter pylori and Helicobacter suis: The Need for One Health Intervention.

Helicobacter species can colonize the gastrointestinal tract of both humans and animals, and are associated with gastrointestinal and extra-gastrointestinal diseases. Some studies indicate that animals, health professionals, and people in close contact with animals might be at higher risk for infection with gastric Helicobacter spp. Considering that veterinarians are professionals at risk for infection with zoonotic gastric Helicobacters and are also seen by many as health communicators concerning zoonoses, the aim of this study was to evaluate the Portuguese veterinarians' perception and knowledge of Helicobacter spp. infection and its zoonotic risk/potential. Therefore, a structured questionnaire composed of 34 dichotomic, multiple-choice, rating scale, matrix, drop-down, and open-ended questions was developed and given to Portuguese veterinarians via an online platform from May 2021 to July 2021, and statistical analysis was used to obtain results. There was a total of 149 respondents, most of them (73.8%) being females. Evidently, Portuguese veterinarians have a limited perception regarding Helicobacter spp. infections. Of the respondents that "have heard of Helicobacter", 17.6% do not know which animal species can be affected by it. Most of the companion animal veterinarians (76.2%) do not consider Helicobacter spp. infection a differential diagnosis when evaluating animals with gastritis. A significant percentage (37.2%) of the respondents that have "heard of H. suis" do not consider it a zoonotic bacterium. There is a need for education and sensitization of veterinarians regarding the potential zoonotic risk of Helicobacter spp. in order to elucidate these professionals to this One Health issue, as the number of reports of non-Helicobacter pylori Helicobacter in livestock, companion, and wild animals is increasing.

Molecular detection of Helicobacter spp. and Fusobacterium gastrosuis in pigs and wild boars and its association with gastric histopathological alterations.

Besides Helicobacter pylori, a Gram-negative bacterium that may cause gastric disorders in humans, non-Helicobacter pylori helicobacters (NHPH) may also colonize the stomach of humans and animals. In pigs, H. suis can induce gastritis and may play a role in gastric ulcer disease, possibly in association with Fusobacterium gastrosuis. In the present study, gastric samples from 71 slaughtered pigs and 14 hunted free range wild boars were tested for the presence of DNA of F. gastrosuis and gastric Helicobacter species associated with pigs, dogs cats and humans, using species-specific PCR assays, followed by sequencing of the amplicon. These gastric samples were also histopathologically evaluated. Almost all the pigs presented gastritis (95.8%). Helicobacter spp. were detected in 78.9% and F. gastrosuis in 35.2% of the animals. H. suis was the most frequently identified Helicobacter species (57.7% of the animals), followed by a H. pylori-like species (50.7%) and less often H. salomonis and H. felis (each in 2.8% of the animals). H. suis was most often detected in the glandular (distal) part of the stomach (pars oesophagea 9.9%, oxyntic mucosa 35.2%, antral mucosa 40.8%), while the H. pylori-like species was mainly found in the non-glandular (proximal) part of the stomach (pars oesophagea 39.4%, oxyntic mucosa 14.1%, antral mucosa 4.2%). The great majority of wild boars were also affected with gastritis (71.4%) and Helicobacter spp. and F. gastrosuis were detected in 64.3% and 42.9% of the animals, respectively. H. bizzozeronii and H. salomonis were the most frequently detected Helicobacter species, while a H. pylori-like species and H. suis were only occasionally identified. These findings suggest that these microorganisms can colonize the stomach of both porcine species and may be associated with gastric pathology. This should, however, be confirmed through bacterial isolation. This is the first description of the presence of F. gastrosuis DNA in the stomach of wild boars and a H. pylori-like species in the pars oesophagea of the porcine stomach.

Alpha2beta1 Integrin Polymorphism in Diffuse Astrocytoma Patients.

Integrins are heterodimeric transmembrane glycoproteins resulting from the non-covalent association of an α and ß chain. The major integrin receptor for collagen/laminin, α2ß1 is expressed on a wide variety of cell types and plays an essential role in the adhesion of normal and tumor cells to the extracellular matrix. Integrin-triggered signaling pathways promote the invasion and survival of glioma cells by modifying the brain microenvironment. In this study, we investigated the association of a specific genetic polymorphism of integrin α2ß1 with the incidence of diffusely infiltrating astrocytoma and the progression of these tumors. Single-nucleotide polymorphism in intron 7 of the integrin ITGA2 gene was examined in 158 patients and 162 controls using polymerase chain reaction and restriction enzyme analysis. The ITGA2 genotype +/+ (with a BglII restriction site in both alleles) exhibited higher frequency in grade II astrocytoma compared to control (P = 0.02) whereas the genotype -/- (lacking the BglII site) correlated with the poorest survival rate (P = 0.04). In addition, in silico analyses of ITGA2 expression from low-grade gliomas (LGG, n = 515) and glioblastomas (GBM, n = 159) indicated that the higher expression of ITGA2 in LGG was associated with poor overall survival (P < 0.0001). However, the distribution of integrin ITGA2 BglII genotypes (+/+, +/-, -/-) was not significantly different between astrocytoma subgroups III and IV (P = 0.65, 0.24 and 0.33; 0.29, 0.48, 0.25, respectively) compared to control. These results suggest a narrow association between the presence of this SNP and indicate that further studies with larger samples are warranted to analyze the relation between tumor grade and overall survival, highlighting the importance of determining these polymorphisms for prognosis of astrocytomas.

Pathological Findings in African Pygmy Hedgehogs Admitted into a Portuguese Rehabilitation Center.

Most of the pathologies that affect hedgehogs are diagnosed postmortem; thus, it is essential to share knowledge between clinicians and pathologists in order to recognize predispositions to diseases and to establish adequate diagnostic and therapeutic plans. This study aimed to describe the most relevant postmortem pathological conditions in a group of six rescued African pygmy hedgehogs, performed over a period of four months. Hedgehogs were submitted to necropsy examinations and subsequent histopathological analyses. Microscopically, all the studied hedgehogs revealed alterations in one or more organ systems. Although a significant and diverse number of pathological conditions were obtained, this study focused on less common or more relevant pathologies found in African pygmy hedgehogs-namely, wobbly hedgehog syndrome, squamous cell carcinoma and mast cell tumors. Furthermore, this study constitutes the first report of Mycobacterium spp. in hedgehogs in Portugal, the second report of follicular thyroid carcinoma in an African pygmy hedgehog, the description of a lipoid pneumonia for the first time in this species and a lung adenocarcinoma-a pathology rarely reported in African pygmy hedgehogs.

Helicobacter spp. in the Stomach of Cats: Successful Colonization and Absence of Relevant Histopathological Alterations Reveals High Adaptation to the Host Gastric Niche.

In addition to Helicobacter pylori, many non-Helicobacter pylori Helicobacters (NHPH) are able to cause gastric disease in humans. Cats are a natural reservoir for many of these species. Accordingly, living in close and intimate contact with animals has been identified as a risk factor, and an important zoonotic significance has therefore been attributed to NHPH. To determine the prevalence and associated gastric histopathological changes of Helicobacter species, the gastric mucosa of 71 cats were evaluated. Only four presented normal histopathological mucosa with the absence of spiral-shaped organisms. Normal gastric mucosa and the presence of spiral-shaped bacteria were observed in 13 cats. The remaining animals presented histopathological changes representative of gastritis. Helicobacter species were detected in 53 cats (74.6%) by at least one detection method. None of the animals were positive for H. pylori or for H. ailurogastricus. Helicobacter heilmannii organisms were identified in 20 animals, predominantly in the body gastric region. Helicobacter salomonis was the second most prevalent species (57.1%), although it was mainly found in association with other NHPH. Helicobacter felis and H. bizzozeronii were less frequently detected. The great majority of the Helicobacter spp. PCR-positive animals presented normal features regarding fibrosis/mucosal atrophy, neutrophils, eosinophils, or other inflammatory cells and lymphofollicular hyperplasia. Given the controversy and the strong evidence of absence of significant histopathological alterations associated with the presence of Helicobacter spp. in cats, it is possible to hypothesize that these bacteria may be able to adapt to the feline gastric microenvironment or even to comprise part of the gastric microbiome of this animal species. Thus, prudency must be taken when prescribing an antibiotic therapy based solely on the presence of these bacteria in the feline stomach.

Indisulam Reduces Viability and Regulates Apoptotic Gene Expression in Pediatric High-Grade Glioma Cells.

Pediatric high-grade glioma (pHGG) is one of the most aggressive brain tumors. Treatment includes surgery, radiotherapy, chemotherapy, or combination therapy in children older than 3−5 years of age. These devastating tumors are influenced by the hypoxic microenvironment that coordinatively increases the expression of carbonic anhydrases (CA9 and CA12) that are involved in pH regulation, metabolism, cell invasion, and resistance to therapy. The synthetic sulphonamide Indisulam is a potent inhibitor of CAs. The aim of this study was to evaluate the effects of Indisulam on CA9 and CA12 enzymes in pHGG cell lines. Our results indicated that, under hypoxia, the gene and protein expression of CA9 and CA12 are increased in pHGG cells. The functional effects of Indisulam on cell proliferation, clonogenic capacity, and apoptosis were measured in vitro. CA9 and CA12 gene and protein expression were analyzed by RT-PCR and western blot. The treatment with Indisulam significantly reduced cell proliferation (dose-time-dependent) and clonogenic capacity (p < 0.05) and potentiated the effect of apoptosis (p < 0.01). Indisulam promoted an imbalance in the anti-apoptotic BCL2 and pro-apoptotic BAX protein expression. Our results demonstrate that Indisulam contributes to apoptosis via imbalance of apoptotic proteins (BAX/BCL2) and suggests a potential to overcome chemotherapy resistance caused by the regulation these proteins.

Decoding the Roles of Astrocytes and Hedgehog Signaling in Medulloblastoma.

The molecular evolution of medulloblastoma is more complex than previously imagined, as emerging evidence suggests that multiple interactions between the tumor cells and components of the tumor microenvironment (TME) are important for tumor promotion and progression. The identification of several molecular networks within the TME, which interact with tumoral cells, has provided new clues to understand the tumorigenic roles of many TME components as well as potential therapeutic targets. In this review, we discuss the most recent studies regarding the roles of astrocytes in supporting sonic hedgehog (SHH) subgroup medulloblastoma (MB) and provide an overview of MB progression through SHH expression and signal transduction mechanisms into the complex tumor microenvironment. In addition, we highlight the associations between tumor and stromal cells as possible prognostic markers that could be targeted with new therapeutic strategies.

The Carbonic Anhydrase Inhibitor E7070 Sensitizes Glioblastoma Cells to Radio- and Chemotherapy and Reduces Tumor Growth.

Glioblastomas (GBMs), the most common and lethal primary brain tumor, show inherent infiltrative nature and high molecular heterogeneity that make complete surgical resection unfeasible and unresponsive to conventional adjuvant therapy. Due to their fast growth rate even under hypoxic and acidic conditions, GBM cells can conserve the intracellular pH at physiological range by overexpressing membrane-bound carbonic anhydrases (CAs). The synthetic sulfonamide E7070 is a potent inhibitor of CAs that harbors putative anticancer properties; however, this drug has still not been tested in GBMs. The present study aimed to evaluate the effects of E7070 on CA9 and CA12 enzymes in GBM cells as well as in the tumor cell growth, migration, invasion, and resistance to radiotherapy and chemotherapy. We found that E7070 treatment significantly reduced tumor cell growth and increased radio- and chemotherapy efficacy against GBM cells under hypoxia. Our data suggests that E7070 has therapeutic potential as a radio-chemo-sensitizing in drug-resistant GBMs, representing an attractive strategy to improve the adjuvant therapy. We showed that CA9 and CA12 represent potentially valuable therapeutic targets that should be further investigated as useful diagnostic and prognostic biomarkers for GBM tailored therapy.

Tuning Green to Red Color in Erbium Niobate Micro- and Nanoparticles.

Tetragonal Er0.5Nb0.5O2 and monoclinic ErNbO4 micro- and nanoparticles were prepared by the citrate sol-gel method and heat-treated at temperatures between 700 and 1600 °C. ErNbO4 revealed a spherical-shaped crystallite, whose size increased with heat treatment temperatures. To assess their optical properties at room temperature (RT), a thorough spectroscopic study was conducted. RT photoluminescence (PL) spectroscopy revealed that Er3+ optical activation was achieved in all samples. The photoluminescence spectra show the green/yellow 2H11/2, 4S3/2→4I15/2 and red 4F9/2→4I15/2 intraionic transitions as the main visible recombination, with the number of the crystal field splitting Er3+ multiplets reflecting the ion site symmetry in the crystalline phases. PL excitation allows the identification of Er3+ high-energy excited multiplets as the preferential population paths of the emitting levels. Independently of the crystalline structure, the intensity ratio between the green/yellow and red intraionic transitions was found to be strongly sensitive to the excitation energy. After pumping the samples with a resonant excitation into the 4G11/2 excited multiplet, a green/yellow transition stronger than the red one was observed, whereas the reverse occurred for higher excitation photon energies. Thus, a controllable selective excited tunable green to red color was achieved, which endows new opportunities for photonic and optoelectronic applications.

Presence of Helicobacter pylori and H. suis DNA in Free-Range Wild Boars.

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that infects half of the human population worldwide, causing gastric disorders, such as chronic gastritis, gastric or duodenal ulcers, and gastric malignancies. Helicobacter suis (H. suis) is mainly associated with pigs, but can also colonize the stomach of humans, resulting in gastric pathologies. In pigs, H. suis can induce gastritis and seems to play a role in gastric ulcer disease, seriously affecting animal production and welfare. Since close interactions between domestic animals, wildlife, and humans can increase bacterial transmission risk between species, samples of gastric tissue of 14 free range wild boars (Sus scrofa) were evaluated for the presence of H. pylori and H. suis using PCR. Samples from the antral gastric mucosa from two animals were PCR-positive for H. pylori and another one for H. suis. These findings indicate that these microorganisms were able to colonize the stomach of wild boars and raise awareness for their putative intervention in Helicobacter spp. transmission cycle.

Transfusion profile, clinical characteristics, comorbidities and outcomes of 3014 hospitalized patients diagnosed with COVID-19 in Brazil.

BACKGROUND: The novel coronavirus disease-2019 (COVID-19) caused a sudden and unexpected increase in the number of hospital admissions and deaths worldwide. The impact of social distancing on blood stocks was significant. Data on the use of blood products by patients with COVID-19 are scarce. MATERIAL AND METHODS: A retrospective observational study was conducted by analysing the medical records of 3014 hospitalized COVID-19 patients in 16 Brazilian hospitals. Individual data related to clinical, laboratory and transfusion characteristics and outcomes of these patients were collected. Patients characteristics association with mortality and transfusion need were tested independently by logistic regression models. RESULTS: Patients mean age was 57·6 years. In 2298 (76·2%) patients, there was an underlying clinical comorbidity. A total of 1657 (55%) patients required admission to intensive care unit (ICU), and 943 (31%) patients required ventilatory support and orotracheal intubation (OTI). There was a total of 471 (15·6%) deaths among all patients. 325 patients (10·7%) required blood transfusion; 3187 blood products were transfused: 1364 red blood cells in 303 patients, 1092 platelet units in 78 patients, 303 fresh frozen plasma in 49 patients and 423 cryoprecipitates in 21 patients. The mortality among patients who received transfusion was substantially higher than that among the total study population. CONCLUSION: Need for transfusion was low in COVID-19 patients, but significantly higher in patients admitted to ICU and in those who needed OTI. Knowledge of the transfusion profile of these patients allows better strategies for maintaining the blood stocks of hospitals during the pandemic.