Catalytic and Physicochemical Evaluation of a TiO2/ZnO/Laccase Biocatalytic System: Application in the Decolorization of Azo and Anthraquinone Dyes

A TiO₂/ZnO oxide system was proposed as a support for the immobilization of laccase from Trametes versicolor (LTV). The obtained TiO₂/ZnO/LTV biocatalytic system was then applied in the decolorization/degradation of C.I. Reactive Black 5 and C.I. Acid Green 25 dyes. The efficiency of immobilization was evaluated based on catalytic properties (Bradford method, oxidation reaction of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and physicochemical (spectroscopic, porous, electrokinetic) analysis. The immobilization process was carried out with high performance (99.4%). Immobilized laccase retained about 40% of its activity in the whole analyzed temperature range and after 10 reaction cycles. Immobilization efficiency was also indirectly confirmed by the presence of characteristic functional groups (–C–H and –C–O), nitrogen and carbon on the TiO₂/ZnO/LTV biocatalytic surface, identified by spectroscopic analyses. The increase in the surface area to 126 m²/g, change of isoelectric point (2.0) and zeta potential ranges (from +12.0 to −20.0 mV) after the immobilization process were also observed. The results show that the designed biocatalytic system enables the removal of acid dyes (C.I. Reactive Black 5 and C.I. Acid Green 25) with high efficiency (99% and 70%, respectively). Mass spectroscopy analysis indicated possible degradation products formed by the cleavage of N=N and C–N bonds.     

Finite Element Analysis and Experimental Investigation of Cut Surface Formation of Magnetic Silicon Steel in Shear Cutting

Shear cutting allows for shaping materials with any length of cutting line with high efficiency and without negative thermal effects, but it causes stresses and deformations in the cutting zone of the material. This has a negative effect on the magnetic properties of the sheet in the areas of the cut edge. The main problem on production lines is to ensure appropriate control of the process so as to obtain the appropriate technological quality of the cut edge, free of not only defects in the form of burrs and shape deviations, but also the minimum deformed zone. This task is difficult due to the large number of control variables, the influence of which on the shaping of the material and the formation of the cut edge is not fully understood. The article attempts to determine the course of the cutting process and to examine the influence of control variables on the formation of the cut edge in the shear-slitting process in which the tools perform a rotary motion. For this purpose, FEM modeling, vision techniques and experimental studies were used. A 3D model of the process was developed, which enables a detailed analysis of the states of stresses, strains, displacements and fracture mechanisms of the material. The simulation results were verified using vision techniques, which were used in the work to observe the flow and cracking mechanisms of the material. Parametric analyses were performed for the process control variables. The research showed a significant influence of the cutting velocity and the clearance between the tools on the formation of the cut edge. The most homogeneous surface of the cut edge with the minimum burr height was obtained for the following parameters: rake angle α = 15–30°, horizontal clearance h_c = 0.03 mm and slitting velocity v₂ = 15 m/min. The developed results can be useful for controlling the cutting process on production lines in terms of maximum process efficiency while maintaining the appropriate technological quality of the cut edge.     

Real-World Experience with CDK4/6 Inhibitors for Metastatic HR+/HER2− Breast Cancer at a Single Cancer Center

BackgroundA study was initiated at Roswell Park Comprehensive Cancer Center to capture the real-world experience related to the use of CDK4/6 inhibitors (Ciclibs) for the treatment of metastatic hormone receptor-positive and HER2-negative breast cancer (HR+/HER2-).Patients and MethodsA total of 222 patients were evaluated who received CDK4/6 inhibitors in the period from 2015 to 2021. Detailed clinical and demographic information was obtained on each patient and used to define clinical and demographic features associated with progression-free survival on CDK4/6 inhibitor-based therapies.ResultsIn this real-world analysis, the majority of patients received palbociclib as the CDK4/6 inhibitor with letrozole or fulvestrant as the predominant endocrine therapies. The median progression-free survival (PFS) in the letrozole (27.6 months) and fulvestrant (17.2 months) groups were comparable to that observed in clinical trials. As expected, age at start of the treatment and menopausal status influenced endocrine therapy utilization but were not associated with PFS. Patients with recurrent disease had shorter PFS (P = .0024) than those presenting with de novo metastasis. The presence of visceral metastasis trended toward shorter PFS (P = .051). Similarly, prior endocrine therapy (P = .003) or chemotherapy (P = .036) was associated with shorter PFS. Body mass index was not associated with PFS or with dose interruption and/or modification. While the number of minorities in this analysis is limited (n = 26), these patients as a group had statistically shorter PFS on treatment (P = .002).ConclusionsThe real-world progression-free survival with CDK4/6 inhibitors mimics that observed in the clinical trial. A number of clinical and demographic features were associated with PFS on CDK4/6 inhibitor-based therapy. Further studies are ongoing to validate these findings incorporating additional cancer centers.

This article reports a real-world experience related to the use of CDK4/6 inhibitors for the treatment of metastatic hormone receptor-positive and HER2-negative breast cancer, focusing on clinical and demographic features associated with progression-free survival.

Implications for PracticeThis study provides the real-world experience with the use of CDK4/6 inhibitors in the treatment of metastatic HR+/HER2− breast cancer. The work defines clinical and demographic features that impact the response to these agents and could offer guidance in preferred strategies for select manifestations of the disease. The study also suggests the need for more study of under-represented minority populations.     

Differences in Expression of Selected Interleukins in HIV-Infected Subjects Undergoing Antiretroviral Therapy

The use of combined antiretroviral therapy (cART) inhibits the replication of the Human Immunodeficiency Virus (HIV) and thus may affect the functioning of the immune system, e.g., induce changes in the expression of certain cytokines. The aim was to examine the effect of cART on the expression of selected cytokines: interleukin -4, -7 and -15 in HIV-infected subjects. The test material was the plasma of HIV-infected men and healthy men (C, control group). The levels of interleukin were measured by immunoenzymatic method before cART and one year after treatment in relation to the C group. HIV-infected men were analyzed in subgroups depending on the HIV-RNA viral load, CD4⁺ and CD8⁺T-cell counts, and the type of therapeutic regimen. A significantly higher level of IL-4 was demonstrated in HIV-infected men before cART compared to those after treatment and in the control group. The use of cART resulted in a significant decrease in the level of IL-7 in HIV-infected men; however, high levels of IL-7 were associated with a low number of CD4⁺ T cells and CD8⁺ T cells. An increase in the level of IL-15 in HIV-infected men was noted after the use of cART. There was no difference in the expression of interleukins depending on the treatment regimen used. The study showed the effect of cART on the expression of interleukins, especially IL-4 and IL-7. Further research in this direction seems promising, confirming the role of these interleukins in the course of the disease.     

Morphology and Properties of Poly(2,6-dimethyl-1,4-phenylene oxide)/Polyamide 11 Hybrid Nanocomposites: Effect of Silica Surface Modification

Poly(2,6-dimethyl-1,4-phenylene oxide)/polyamide 11 (PPO/PA11 80/20) blend filled with neat (SiO₂) or modified silica having amine functional groups (A-SiO₂) was melt mixing in a twin-screw extruder. The silica was prepared by the sol–gel process. SEM shows that, with increasing A-SiO₂ content from 1 to 5 wt.%, the morphology of PPO/PA11blend changed from droplet matrix to co-continuous with phase inversion. The phase inversion was also observed for 5 wt.% of neat silica, but the droplet-matrix structure was retained. The overall rheological and mechanical properties improvement of the A-SiO₂-filled composites in comparison with the unfilled blend and neat silica counterpart was drastic, especially in terms of viscosity and stiffness. A-SiO₂ improved PPO and PA11 miscibility and reduced the crystallinity of PA11, without affecting the T_c, owing to the compatibilization effect. On the other hand, neat silica slightly increased the crystallinity of PA11 and decreased the crystallization temperature of PA11 and the glass transition temperature of PPO as a result of its plasticization.     

Cryoablation of ventricular arrhythmias originating from septal aspects of mitral and tricuspid annulus

Two cases of frequent ventricular ectopy are described. Case one: a 49 year-old woman with post myocarditis extrasytoles (34 000/24 h). The ectopic focus was located on the tricuspid annulus - directly in the area of largest and sharpest His bundle potential and where direct His bundle capture was observed during all pace mapping attempts. Case two: a 15 year- -old men with idiopathic, very frequent premature ventricular beats from septal aspect of the mitral annulus. The area of earliest activation during the spontaneous ectopy with 12/12 pace map match showed obvious His bundle potential, moreover, the radiofrequency ablation catheter was unstable in that position (inferoseptal from retrograde aortic approach). In both cases treatment with cryoablation was successfully and uneventful. In conclusion, cryoablation instead of radiofrequency current ablation should be used for ventricular ectopy from septal part of the tricuspid or mitral annuli especially in cases of parahisian localisation and/or catheter instability.     

In utero myelomeningocele repair reduces intensification of inflammatory changes in the dura mater and the skin

Objective: Chemical and mechanical injury in myelomeningocele (MMC) during the fetal life results in functional disorders of multiple organs. Prenatal MMC repair reduces sequelae of spinal cord injury.Design: Histopathological evaluation of dura mater and skin specimens to assess the severity of inflammatory changes.Setting: Histopathological laboratory and operated patients.Participants: 45 cases (Group I)-intrauterine surgery due to MMC and 42 cases (Group II)-postnatal surgery.Outcome measures: Specimens of the skin and of the dura mater adjacent directly to the uncovered section of the spinal cord were collected for assessment. The specimens were histopathologically evaluated to assess the severity of inflammatory changes.Results: The analysis of the severity of inflammatory changes in the skin and the dura mater showed only small lymphocytic infiltration in 5 fetuses (Group I). Medium and large infiltration in the skin and the dura mater was found in all children who underwent postnatal surgery (Group II). Lymphocytic and granulocytic infiltration in the skin and the dura mater were statistically significantly more prevalent in children who underwent postnatal surgery compared to the group of children who underwent prenatal surgery (P < 0.000003).Conclusions: By reducing the time of exposure to damaging factors, prenatal MMC repair statistically reduces the risk of inflammatory changes in the exposed spinal cord and spinal nerves. Prenatal closure of spina bifida before 24 week of gestation does not reduce the severity of inflammatory changes in the exposed spinal cord.     

Modification of Hydrogenation and Corrosion Properties of Hydrogen Storage Material by Amorphous TiCrFeCoNi HEA Layer

The effect of encapsulation of LaNi_4.5Co_0.5 powdered hydrogen storage material with ≈0.5 µm thick, magnetron-sputtered amorphous film of TiCrFeCoNi high-entropy alloy (HEA) on functional hydrogenation parameters of the hydride electrode is discussed. The multicycle galvanostatic charge/discharge tests carried out in deaerated, 6 M KOH solution allow for determining specific capacity decrease, exchange current density of the H₂O/H₂ system, and high rate discharge ability (HRD) of the hydride electrodes. Concentrations of individual constituents of the HEA in the particle coating determined by EDS analysis were practically the same (≈20 at.%) as in the applied TiCrFeCoNi target material. The XRD phase analysis pointed out the amorphous structure of the HEA coating. The presence of HEA coating decreases capacity by 10–15 per cent, but increases exchange current density for H₂O/H₂ system. The effect of HEA on capacity fade is ambiguous: low for 10–25 cycles (most probably due to effective corrosion inhibition) and distinct at long-term cycling (most probably due to galvanic effects resulting from mechanical degradation of particle surface). The presence of HEA coating considerably improves the HRD of the electrode material: for a discharge rate of 5C, the HRD coefficient becomes 4.6 times greater for HEA modified storage material.     

TiO2-Modified Magnetic Nanoparticles (Fe3O4) with Antibacterial Properties

This paper presents the synthesis and characteristics of Fe₃O₄/C/TiO₂ hybrid magnetic nanomaterials with antibacterial properties. The materials used were obtained using a microwave-assisted two-stage precipitation method. In the first stage, magnetite nanoparticles (Fe₃O₄) were prepared with the precipitation method, during which an additional glucose layer was placed on them. Next, the surface of Fe₃O₄ nanoparticles was covered by TiO₂. It was observed that the addition of carbon and titanium dioxide caused a decrease in the average size of magnetite crystallites from 15.6 to 9.2 nm. Materials with varying contents of anatase phase were obtained. They were characterized in terms of phase composition, crystallite size, specific surface area, surface charge and the kinds of function groups on the surface. The results show a successful method of synthesizing hybrid magnetic nanoparticles, stable in a solution, with antibacterial properties under direct solar light irradiation. Compared to classical materials based on TiO₂ and used for water disinfection, the obtained photocatalytic nanomaterials have magnetic properties. Owing to this fact, they can be easily removed from water once their activity under direct irradiance in a given process has completed.     

Plant-Oil-Based Fibre Composites for Boat Hulls

Plant-oil-based fibre composites for boat hulls are an interesting and growing group of materials. Although many problems are to be tackled at different stages of their preparation, the green composites are already successfully commercialised. Within this paper, the most important chemical and physical characteristics of both natural fibres and sustainable resins are provided in the form of a comprehensive review. Finally, the complex issue of interactions filler–matrix is considered.