Longer Exposure Times Research Articles

Mortality and Repellency Effect of Some Essential Oils against Tribolium castaneum (Coleoptera: Tenebrionidae)

The red flour beetle (Tribolium castaneum) is a major pest of stored grains, causing significant economic losses. In recent years, essential oils have gained attention as eco-friendly alternatives to synthetic pesticides. This study evaluated the insecticidal and repellent properties of three essential oils—lavender (Lavandula spica), mogra (Jasminum sambac), and rose (Rosa damascena)—against T. castaneum. Toxicity was assessed using direct contact and fumigation methods, targeting adult T. castaneum, respectively. Repellency was tested on larvae using filter paper assays and bioassays were conducted at varying doses and exposure durations. In direct contact assays, adult mortality increased with higher doses and longer exposure times. Lavender oil showed the highest toxicity (LD50 = 0.366–0.143 µl/cm²), followed by Mogra oil (LD50 = 1.037–0.147 µl/cm² at 3–48 h) and rose oil (LD50 = 0.651–0.188 µl/cm²). In fumigation assays, rose oil was the most effective against the target insect (LD50 = 4.031–2.252 µl/cm² at 24–48 h), followed by lavender oil (LD50 = 4.980–3.180 µl/cm²) and mogra oil (LD50 = 7.339–5.463 µl/cm²). Overall, the direct contact method was more effective than fumigation. Repellency assays showed mogra oil exhibiting significant effects (F = 25.25, P < 0.001) and achieving 100% repellency at 0.0785 µl/cm² within 3–4 hours, whereas lavender and rose oils showed lower and statistically insignificant effects. This study highlights the potential of essential oils as biopesticides for managing T. castaneum. Mogra oil demonstrated superior efficacy in direct contact assays, while rose oil excelled in fumigation tests. These findings support the use of essential oils as eco-friendly alternatives for pest management in stored grains.

Enhancement of antioxidative potential of mung bean by oxygen plasma irradiation of seeds

The present study aimed to assess the effect of oxygen plasma treatment on the germination rate, growth, and antioxidative activity of mung beans at different pressures and irradiation exposure times. Oxygen plasma was capable of shortening the germination time as well as improving the germination rate at each gas pressure and exposure time compared to control. The germination rate of plasma-treated seeds exceeded 90% within 18 h of seeding compared to 30 h for the control (without plasma treatment). Stem length increased by 25.42 to 52.88% depending on the pressure and exposure time compared to control. Vitamin C content in the stem and root increased from 1.49 to 1.97 and 1.27 to 2.04-fold higher, respectively, depending on the pressure and exposure time compared to control; while in the case of thiol content, it was 1.16 to 2.76 and 1.09 to 2.49-fold higher in the stem and root, respectively. Plasma treatment increased antioxidant potency compared to control. Maximum antioxidant potency was found at 30-min exposure time, although the alterations in pressure did not elicit prominent changes. Plant growth, vitamin C and thiol contents, and antioxidant potency were increased with increasing pressure up to 60 Pa, which then declined with higher pressure. On the other hand, these parameters decreased with a longer exposure time, except for the antioxidants. Thiol and vitamin C contents were associated with plant growth.

Bacterial air contamination and the protective effect of coverage for sterile surgical goods: A randomized controlled trial.

There is limited knowledge regarding how long prepared sterile goods can wait before becoming contaminated. We investigated whether surgical goods could be prepared the day before surgery and kept sterile overnight in the operating room, if protected by sterile covers. Sterile surgical goods for open-heart surgeries (n=70) were randomized to preparation on the morning of the operation or on the previous evening. Exposure time was the total time between preparation and use. Primary outcome was bacterial growth reported as colony forming units (cfu), isolated on 840 agar plates. The protocol was registered with ClinicalTrials.gov (NCT05597072). When the agar plates were protected with sterile covers, exposure time had no impact (intervention group: 7 cfu, control group: 17 cfu). Without protection, longer exposure time was associated with more cfu (p=0.016). A total of 499 cfu were isolated, displaying 59 different types of bacteria including 13 resistant Staphylococcus epidermidis, 6 (46%) of which were multidrug resistant. Sterile goods could wait in the operating room for at least 15 hours before use without increased risk of bacterial air contamination, if protected with sterile covers. However, if the goods were not covered, bacterial air contamination occurred over time.

Surface modification of 3D-printed polycaprolactone- human decellularized bone matrix composite scaffold by plasma for bone tissue engineering

BackgroundBone tissue engineering is a revolutionary field focused on creating viable bone substitutes using advanced materials and techniques. Utilizing 3D printing, precise and customizable bone scaffolds can be produced. A notable composite material in this domain is a composite of polycaprolactone (PCL) and human decellularized bone matrix (hDBM), which combines synthetic and natural elements for enhanced functionality. To further improve cell attachment and growth, cold plasma surface modification is employed, optimizing scaffold surfaces. These innovations collectively hold great potential for improving bone repair and regeneration outcomes. MethodsScaffold architecture was designed through CAD software, and the composite of PCL and hDBM was printed using FDM technology. Surface modification was achieved by exposing the scaffolds to Argon-Oxygen (Ar-O₂) plasma radiation for 1 and 3 minutes. Both treated and untreated scaffolds were characterized, including measurements of surface roughness, hydrophilicity, and cellular activity. ResultsAlmost all groups showed non-toxic effect on cellular behavior during cell culture. Plasma-treated scaffolds showed a significant increase in surface roughness, with roughness values (Ra) increasing from 10.45 nm (untreated) to 62.75 nm after 3 minutes of plasma exposure. Contact angle measurements decreased from approximately 66.5° in untreated scaffolds to 31.4° in those treated for 3 minutes, indicating enhanced hydrophilicity. Plasma-treated scaffolds demonstrated excellent cytocompatibility, significantly enhancing cell proliferation, osteogenic differentiation, and mineralization compared to untreated scaffolds. After 7 days, scaffolds treated for 1 and 3 minutes showed 35% and 60% increases in cell proliferation, respectively, highlighting the role of plasma treatment in creating a bioactive surface conducive to cell adhesion, growth, and improved osteogenic properties, with longer exposure times further amplifying these effects. ConclusionsThe current study demonstrates the efficacy of Ar+O₂ plasma treatment in enhancing the surface properties of PCL-hDBM scaffolds, making them more conducive to osteogenesis. This study suggests that plasma-treated PCL-hDBM scaffolds are a promising option for bone tissue engineering applications.

Toxicological Effects of Sewage Sludge on Biochemical Biomarkers of Earthworms (Eisenia andrei)

ABSTRACTSewage sludge, or biosolids, produced in wastewater treatment plants (WWTP) can be used as an alternative to organic fertilizer in the agricultural field. However, it holds a large amount of anthropogenic chemicals, such as drugs and metals. The aim of the present study is to evaluate biochemical biomarker responses in earthworms (Eisenia andrei) exposed to soil presenting different sludge concentrations deriving from the largest WWTP in Southern Brazil. Treatments comprised 3%, 6%, 12%, 24%, 50%, and 75% of sludge incorporated to native forest soil, 100% of sludge and the control group (0%). Concentrations of different drugs, mainly of antibiotics, as well as high sulfur, magnesium, potassium, zinc, and phosphorus were identified in analyzed sewage sludge. Exposed earthworms were collected on the 7th, 14th, and 28th day of the experiment and subjected to analysis of lipid peroxidation levels (TBARS), acetylcholinesterase (AChE), catalase (CAT), and glutathione S‐transferase (GST) activity. Treatments with 50%, 75%, and 100% of sludge were lethal to earthworms after 7 days. Based on biochemical tests performed in treatments with 3%, 6%, 12%, and 24% of sludge, the highest sludge concentrations (12% and 24%) and the longest exposure time (28 days) led to significant changes in biomarkers. Therefore, sewage sludge must be incorporated into the soil at concentrations lower than 3%, mainly due to changes in CAT, AChE, GST, and the resulting lipid damage observed at concentrations of 6%, 12%, and 24%.

A mineralogical and geological study for tungsten extraction from alkaline granite in Abu Kharif area, North Egyptian Nubian Shield

ABSTRACT Wolframite-quartz vein-type represents a significant global tungsten resource essential to tungsten production. In the northern Arabian-Nubian Shield (Egypt), such mineralisation is associated with the Abu Kharif alkaline granite (614.6 ± 3.6 Ma). Mineralised quartz veins, containing mixed wolframite ore (603.7 ± 7.4 Ma), occur along the contact between these granites and metavolcanic rocks, accompanied by extensive alkali alteration. Wolframite is the foremost valuable mineral in this ore, along with scheelite and hübnerite. Despite extensive research on Abu Kharif alkaline granites and associated ore, tungsten extraction from the mineralised quartz remains understudied. This study presents an efficient method for tungsten extraction involving two stages: physical beneficiation and chemical processing techniques. An optimal tungsten recovery was achieved using a Na2CO3 fusion leaching technique, yielding a high tungsten trioxide concentration in the tungsten concentrate after chemical scrutiny. Key variables, including temperature, time, and concentrate-to-Na2CO3 ratio, were analysed for their impact on leaching efficiency. Experimental results indicate that the fusion leaching method achieves optimal efficiency with a concentrate-to-Na2CO3 ratio of 1/2.5, a fusion time of 3 h, and a fusion temperature of 600 °C. The fusion leaching tests showed that more reagents, higher temperatures, and longer exposure time did not significantly improve the leaching process.

Influence of neodymium-doped yttrium aluminum garnet laser exposure time on cytokine secretion in lipopolysaccharide-challenged rat peripheral blood mononuclear cells

Multiple investigators have suggested that infrared laser energy facilitates hard and soft tissue wound healing through various mechanisms, including the suppression of inflammation. This study investigated the influence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser exposure time on pro-inflammatory cytokine/chemokine concentrations in lipopolysaccharide (LPS)-stimulated rat peripheral blood mononuclear cells (PBMCs). Cultured rat PBMCs were stimulated with various LPS concentrations (0, 10, 100, or 1000 ng/mL) and treated with Nd:YAG laser irradiation for 0 (control), 30, 45, or 60 s. For these experiments, the average power, pulse duration, and repetition rate remained constant at 5 W, 100 μs, and 20 Hz, respectively. Luminex magnetic microsphere immunoassays were used to compare the secretion of 27 inflammatory mediators from LPS-stimulated PBMCs in laser-irradiated versus control groups. Two-way analysis of variance was used to compare the main effects of laser exposure time and LPS concentration on cytokine/chemokine concentrations and evaluate the potential interaction between these factors. Four pro-inflammatory cytokines – tumor necrosis factor-α, macrophage inflammatory protein (MIP)-1α, MIP-2, and interferon gamma-induced protein-10 – exhibited a trend of reduced secretion in laser-irradiated cultures. The effect appeared more pronounced at longer exposure times (45 and 60 s). However, none of the 27 inflammatory mediators exhibited statistically significant reductions in concentrations in laser-irradiated cultures versus control cultures. These observations do not support a robust anti-inflammatory effect of Nd:YAG laser irradiation. Further studies should explore the potential impact of Nd:YAG laser irradiation on cytotoxicity and cellular growth kinetics and extend across a range of irradiation parameters and cell types.

The Effects of Intensity, Exposure Time, and Distance of Polymerization Light on Vickers Microhardness and Temperature Rise of Conventional Resin-Based Composite.

(1) Background: This study investigates the effects of curing light intensity, exposure time, and distance on the Vickers microhardness (VMH), hardness bottom-to-top ratio (HR), and temperature rise (TR) of conventional dental resin-based composite (RBC). (2) Materials and Methods: Specimens of one conventional RBC (Tetric EvoCeram, Ivoclar Vivadent) were cured with 12 different curing protocols (CPs), created with three different light intensities (Quartz Tungsten Halogen 300 mW/cm2, LED 650 mW/cm2, LED 1100 mW/cm2), two exposure times (20 and 40 s), and two distances of curing tip (0 and 8 mm). The VMH of top (VMH-T) and bottom (VMH-B) surfaces was measured. The hardness bottom-to-top ratio (HR) was calculated from VMH-B and VMH-T. The HR below 80% was rated as inadequate polymerization. The TR at the depth of 2 mm within the RBC was measured using a K-type thermocouple. Data were analyzed using Levene's test and the multivariate analysis of variance (MANOVA). The level of significance was set at p < 0.05. (3) Results: Exposure time and distance significantly influenced VMH-B and HR. Increased distance significantly reduced VMH-B, HR, and TR. CPs 300 mW/cm2/8 mm/20 s and 650 mW/cm2/8 mm/20 s produced inadequate polymerization (HR < 80%). Prolonged exposure time produced higher values of VMH-B and HR. The TR was significantly influenced by light intensity and distance. (4) Conclusions: Suboptimal light intensity (<800 mW/cm2) can produce inadequate polymerization at the lower side of the composite layer when used from a distance. Prolonged irradiation can improve the polymerization to a certain extent. Clinicians are advised to monitor the intensity of the LCUs in order to optimize the photopolymerization process. Caution is required when polymerizing with high-intensity curing light in direct contact with the RBC with longer exposure times than recommended.

In vitro Antileishmanial Effect of Scrophulariabavanatia Extract on Leishmania (L) tropica [MHOM/NADIM3

Background: Cutaneous Leishmaniasis (CL) is a widespread parasitic disease that causes skin lesions and ulcers. Although the World Health Organization recommends Glucantime as a treatment for CL, this remedy presents unexpected side effects and high costs. This study investigates the in vitro antileishmanial effect of Scrophulariabavanatia hydroalcoholic extract on Leishmaniatropica promastigotes. Objectives: This study aims to evaluate the in vitro antileishmanial effects of a local Scrophulariabavanatia hydroalcoholic extract on Leishmania (L.) tropica [MHOM/NADIM3] promastigotes. Methods: Various concentrations (0.2, 1, 5, 25, and 125 mg/mL) of Scrophulariabavanatia methanol extract were prepared and added to cultures containing the parasite. The amastigote form of the L. tropica strain [MHOM/IR/NADIM3] was isolated from mouse spleens and transformed into promastigotes in Novy-Nicolle-Mac Neal medium. The antileishmanial activity of Scrophulariabavanatia extract was then compared to Glucantime using cell proliferation ELISA. Results: The LC50 values in the stationary stage for both Scrophulariabavanatia extract and Glucantime (mg/mL) were greater than in the dynamic stage. The extract at concentrations of 0.2, 1, 5, 25, and 125 mg/mL did not show significant differences after 24 and 48 hours (P &gt; 0.05) compared to negative controls but did show a significant effect after 72 hours (P = 0.000). The extract demonstrated increased effectiveness with higher concentrations and longer exposure times. Conclusions: Scrophulariabavanatia extract inhibits the survival and growth of Leishmania promastigotes. Future studies should further explore its effects on in vivo survival of the parasite.

Mechanical Properties and Microstructural Characteristics of Steel Pipes after Long-Time Hydrogen Exposure

There are three possibilities to transport hydrogen by high pressure pipeline (i) blending hydrogen into the existing natural gas pipeline system, (ii) after checking the integrity, using the natural gas transporting pipeline system to transport hydrogen, (iii) building a new pipeline system to transport pure hydrogen. In all three cases should be known the behaviour of the pipe material and its welded joints influenced under high pressure hydrogen. For this aim pipeline sections made of P355NH base material were investigated without and with hydrogen exposure, where the exposure time was 41 days. Gas metal arc welding and hybrid tungsten arc welding / gas metal arc welding were applied for preparation of the girth weld joints. Tensile, three point bending and hardness tests, furthermore microstructural investigations were performed both on base materials and girth welds of the pipeline sections. The testing results were analysed and compared with each other (base material vs. welded joints, without exposure vs. with exposure) and with limit values can be found in the literature. Conclusions were drawn on the behaviour of the investigated pipe material and its welded joints.

Quantifying motion blur by imaging shock front propagation with broadband and narrowband X-ray sources

Time-integrated radiography using MeV Bremsstrahlung X-ray sources is the norm for imaging during system-level testing of components and structures under dynamic condition. One source of error in the analysis of the time-integrated radiography data sets stems from motion blur which smears out sharp interfaces to a greater degree with longer exposure times, which become necessary to provide sufficient signal-to-noise with low X-ray penetration of objects of interest. To quantify motion blur, a 1D shock wave through PMMA was investigated experimentally at The Dynamic Compression Sector at The Advanced Photon Source (DCS@APS) with tapered broadband and 25.46 ± 1.06 keV narrowband X-rays. Four cameras with different exposure times were used for each experiment to compare the effect that exposure time has on motion blur. In addition, our methodology to accurately simulate motion blur in terms of transmission and shape is presented and compared to our experimental results and quantified. There is a high level of agreement between the experimental and simulation results across the range of data sets investigated in this study with a percent difference range of 0.29–1.31% for the four shots. The methodology of this work serves as a steppingstone towards a physically validated model that could be used in conjunction with experimental results to deconvolve physical parameters, densities, and interfaces of interest in a way that would not be possible with experimental results alone.

The Harmful Effects of Welding Fumes on Human Dental Enamel-A Microhardness Analysis.

Introduction: Over the years, welding fumes' harmful effects have been demonstrated countless times in the scientific literature. Recently, studies in the field have shown an increasing interest in the negative consequences that these fumes may have on the tissues of the oral cavity. Materials & method: The current study aimed to investigate the impact that welding fumes have on the structure of human dental enamel by analyzing the microhardness of the dental enamel in 15 extracted human teeth, after various exposure times, using the Vickers method. Results: The results obtained after 48, 96, 168, and 336 h of direct exposure of the extracted specimens to the welding fumes show a statistically significant increase in the depreciation of the dental enamel's microhardness, related to the duration of exposure (p < 0.05). An average of 305 Vickers units was observed at the longest exposure time, 336 h, in the present study, whereas in the control group, the microhardness analysis showed an average of 327 Vickers units.

Exposure effects of synthetic glucocorticoid drugs on skeletal developmental and immune cell function in zebrafish

Synthetic glucocorticoids (GCs) are used to treat a wide range of human health conditions and as such are frequently detected in the aquatic environment. This, together with the highly conserved nature of the glucocorticoid system across vertebrates means that the potential for biological effects of GCs in fish is relatively high. Here, we found that exposure of zebrafish (Danio rerio) to environmentally relevant concentrations of 4 of the most widely used synthetic GCs (beclomethasone dipropionate, budesonide, fluticasone propionate, and prednisolone), from 0 to 4 days post fertilisation (dpf), resulted in no effects on embryo-larval development or bone and cartilage formation. However, after exposure to equivalents of human therapeutic plasma levels, developmental abnormalities were observed that included pericardial oedema, blood pooling and alterations in jaw cartilage. Furthermore, using a double transgenic zebrafish osteoblast and chondrocyte reporter line, exposure up to 10 dpf resulted in alterations to lower jaw cartilage and bone development for all compounds at, and above, human therapeutic plasma concentrations. In the case of beclomethasone dipropionate, a reduction in lower jaw intercranial distance was observed at the environmentally relevant concentration of 0.1 μg/L. Using further transgenic reporter lines with fluorescently tagged neutrophils and macrophages, we also show exposure of embryo-larvae (0–4 dpf) to the GCs tested resulted in altered immune cell migration, but only at relatively high exposure concentrations. Collectively, our findings show GC exposure impacts embryo-larval zebrafish development, immune function, and skeletal formation, but predominantly at concentrations greater than those currently reported for the aquatic environment. Despite this, however, it is suggested that studies with longer exposure times, and to mixtures of multiple GCs (many GCs act via the same mechanism of action) are warranted before we can confidently assert that these commonly detected contaminants do not pose a risk to fish in the wild.

Cytotoxicity and genotoxic impacts of LAPONITE® on murine adipose stem cells

This study comprehensively characterized LAPONITE® and evaluated its cytotoxic and genotoxic effects on rat adipose-derived stem cells (ADSCs). Chemical analyses included Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. Cytotoxic screening using the Artemia salina lethality test indicated low toxicity. ADSCs exhibited mesenchymal stem cell chracteristics. LAPONITE® demonstrated osteogenic induction capability. MTT assays revealed increased cell viability across concentrations and exposure times. The comet assay for genotoxicity showed no significant differences in damage index between experimental groups, except for a distinction in the frequency of damage between LAPONITE® concentrations at the longest exposure time. This comprehensive assessment provides valuable insights into the safety and potential applications of LAPONITE® in regenerative medicine.

Effect of irradiation on the corrosion of 304 stainless steel in pressurized water reactor (PWR) simulated water chemistry

In this study, the corrosion behavior of pre-ion-irradiated 304 SS is compared to that of un-irradiated 304 SS in simulated Pressurized Water Reactor (PWR) conditions for both early stages of corrosion and longer exposure times. Transmission electron microscopy is used to characterize the oxide scale. The study shows that although the pre-irradiated microstructure does not change the nature of the oxide and its dual-layer structure (i.e. inner/outer oxide layers) formed on 304 SS, the path of growth of the inner oxide layer is affected by the irradiated microstructure resulting in oxide protrusions into the matrix; a mechanism is proposed.

Obtaining Phenolic-Enriched Liquid Fractions and Compostable Pomace for Agriculture from Alperujo Using Standard Two-Phase Olive Oil Mill Equipment

Olive oil extraction by two-phase systems generates a by-product called “alperujo” which presents several difficulties for its valorization. The present work evaluated an industrial approach, based on the application of thermal treatments to alperujo followed by solid/liquid separation using standard two-phase olive oil mill equipment. Treatments consisted of the thermo-malaxation of alperujo at 70 °C for 45 or 90 min, with or without acid addition, followed by solid/liquid separation in an industrial decanter. The solid was characterized concerning subsequent use for composting, while total and hydrophilic phenolics were analyzed in liquid for their recovery. Additionally, a laboratory-scale trial to compare phenolic purification by ethylic acetate extraction with chromatographic procedures was also included. The static respiration index showed that solid fractions presented higher susceptibility to biodegradation processes than raw alperujo. The phenolic content of treated liquid fractions was higher than in raw alperujo. Total phenolics were maximum at the longest exposure time without acid addition, while hydrophilic phenolics were highest at the shortest exposure time in acidified samples. The use of non-ionic resins seemed attractive for obtaining highly concentrated phenolic fractions. The proposed thermal treatments can be applied in olive oil industries, allowing in situ pomace valorization and the recovery of phenolic-enriched liquid fractions.

Electrosynthesis-Induced Pt Skin Effect in Mesoporous Ni-Rich Ni-Pt Thin Films for Hydrogen Evolution Reaction.

A Pt skin effect, i.e., an enrichment of Pt within the first 1-2 nm from the surface, is observed in as-prepared electrodeposited Ni-rich Ni-Pt thin films. This effect, revealed by Rutherford backscattering (RBS), is present for both dense thin films and mesoporous thin films synthesized by micelle-assisted electrodeposition from a chloride-based electrolyte. Due to the Pt skin effect, the Ni-rich thin films show excellent stability at the hydrogen evolution reaction (HER) in acidic media, during which a gradient in the Pt/Ni ratio is established along the thickness of the thin films, while the activity at the HER remains unaffected by this structural change. Further characterization by elastic recoil detection with He ions analysis shows that hydrogen profiles are similar to those of Pt: a surface hydrogen peak coincides with the Pt skin, and a gradient in hydrogen concentration is established during HER in acidic media, together with a considerable uptake in hydrogen. A comparative study shows that in alkaline media, hydrogen evolution has little to no effect on the structural properties of the thin films, even for much longer times of exposure. The mesoporous thin films, in addition to their higher efficiency at HER compared to dense thin films, also show lower internal stress, as determined by Rietveld refinement of grazing incidence X-ray diffraction patterns. The latter also reveal a fully single-phase and nanocrystalline structure for all thin films with varying Ni contents.

High Q factor of photonic cavity with SU-8 photoresist micro-disk for electromagnetic wave control

How to control electromagnetic wave effectively is the key to the realization of applicable filters in many optics technologies. In our work, a SU-8 photoresist micro-disk is written onto a photonic crystal waveguide to control electromagnetic wave. Corresponding simulation and experiment shows that, the quality Q increases as the thickness of SU-8 smaller. When the thickness exceeds 400 nm, the change of thickness has little influence on electromagnetic waves. Besides, the increase of the radius of disc-shaped SU-8 can also increase the Q value. By optimizing the simulation and experimental data, we can successfully create a SU-8 photoresist micro-disk cavity with the thickness of 5 µm and height of 20 nm, the quality factor of Q can reach 8200. However, longer exposure time and more stable experimental equipment is needed if we want to get a larger radius. The method in our work by using SU-8 photoresist micro-disk on photonic crystals to control electromagnetic wave is more practical and flexible, which can provide new significance for research into optical filter.

Evaluation of Single and Combined Temozolomide and Doxorubicin Treatment Responses in Low- and High-Grade Glioma In Vitro.

Astrocytoma, the most common type of glioma, can histologically be low or high grade. Treatment recommendations for astrocytic tumors are based on the histopathological and molecular phenotype. For grade 2 astrocytoma, the combination of radiotherapy and adjuvant chemotherapy with procarbazine, lomustine, and vincristine (PCV) is better than radiotherapy alone. Temozolomide (TMZ) is being increasingly recognized as a replacement for PCV in brain tumor therapy, due to the lower myelotoxicity. TMZ is currently a well-established first-line treatment for grade 3 astrocytoma, grade 4 astrocytoma, and glioblastoma and it is also sporadically used for grade 2 astrocytoma. However, TMZ faces multiple challenges such as adverse effects and drug resistance. In this study, we compared the cytotoxic effect induced by TMZ and doxorubicin (DOXO), alone and in combination, on a low-grade astrocytoma cell line (AC1B) and a high-grade glioma cell line (GB1B). We found that TMZ and DOXO, each produced a cytotoxic effect in monotherapy. GB1B cell line was more sensitive to the treatment than AC1B cells, at a 7- and 10-day exposure to the DOXO. However, when the duration of the treatment was extended to 14 days, GB1B cells became more resistant to DOXO treatment, compared to AC1B cells. Regarding the treatment with TMZ, GB1B exhibited greater resistance to TMZ compared to AC1B, across all studied intervals and the resistance to treatment of GB1B increased with longer exposure time. However, in combined therapy, the drugs did not exert a synergistic effect on any astrocytic cell line. The current data suggest that both TMZ and DOXO exhibit efficient therapeutic effects on low- and high-grade glioma cells. However, no synergistic effect was observed for combined therapy.

Enhancing corrosion resistance of 316L stainless steel through electrochemical deposition of polyaniline coatings in acidic environments

Stainless steel is widely used because of its excellent corrosion resistance in typical environments. However, it is susceptible to corrosion in acidic media, therefore, to address this issue, the electrochemical deposition of polyaniline coatings on 316L stainless steel was investigated using cyclic voltammetry at different potential windows and scan rates. The successful polymerization and surface morphology were analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Moreover, thermal stability of the PANI coating was assessed through thermo gravimetric analysis while the corrosion behavior of bare and coated steels immersed in 1M H2SO4 was studied using electrochemical impedance spectroscopy (EIS). Based on the Nyquist plots obtained from the EIS revealed that the corrosion resistance of the PANI coating improved significantly with a decrease in scan rate and by limiting the upper potential, especially during longer exposure times up to 72 h. Results suggest that controlling the deposition parameters and optimizing the electrochemical conditions can lead to even greater improvements in the corrosion resistance of the stainless steel. These findings offer valuable insights for researchers and engineers in the field of materials science and corrosion protection, enabling them to develop more precise and efficient strategies for enhancing the durability and performance of stainless steel in acidic environments.