UV-Vis Spectrophotometry Research Articles

A novel nanovoltammetric sensor design for the sensitive determination of caffeic acid in Turkish coffee

Caffeic acid has anti-inflammatory, antibacterial, anticarcinogenic and immunomodulatory properties as well as antioxidant properties. Therefore, precise determination of the quantity of this acid is important for analytical and therapeutic interests as well as for the safety and quality of food samples. This study aims to determine the amount of caffeic acid in Turkish coffee by using the square wave voltammetry technique. This method has been successfully applied for the precise determination of caffeic acid with a platform in which the glassy carbon electrode is constructed with a modifier obtained based on the synergistic effect of functionalized multi-walled carbon nanotubes with boron oxide nanoparticles. The proposed platform and method gave a quantification limit of 0.04 nM in a dynamic range of 1.0 nM ˗ 40 μM for caffeic acid and was successfully used in the Turkish coffee sample to determine caffeic acid. In addition, the results are found in line with the results obtained by UV-Vis spectrophotometry method, and the good recovery values also imply the feasibility of the platform for practical application.

Application of validated UV-Vis spectrophotometry-colorimetric methods for specific quantification of deferiprone in the development of iron-responsive nanoparticle loaded into dissolvingmicroneedle.

Deferiprone (DFP) is one of the iron-chelating agents used in iron overload therapy for patients with ß-thalassemia major (ß-TM). However, the use of DFP is limited as it experiences a first-pass effect and can potentially cause iron deficiency due to uncontrolled release. Therefore, iron-responsive (NP-IR) DFP nanoparticle innovation was developed to control DFP release. A dissolving microneedle system (NP-IR-DMNs) was used to maximize DFP release. However, in support of this development, validation of analytical methods using spectrophotometry and colorimetrics was carried out. UV-Vis spectrophotometry is an approach that is easy to use, practical, and more cost-effective than others. The DFP levels were determined in normal and iron-overloaded medium solutions with 1%, 2%, and 4% concentrations. In addition, DFP levels were also measured in rat plasma using the colorimetric method with the addition of FeCl3 reagent to increase sensitivity for the detection of the analyte. The procedures used as guidelines in the validation procedure are The International Council for Harmonization (ICH). As a result, all linear correlation values of medium and plasma ≥ 0.999 were obtained. The LOQ levels obtained were 0.55µg/mL, 0.44µg/mL, 0.42µg/mL, 0.52µg/mL, and 1.01µg/mL in plasma, 1% FeSO4, 2% FeSO4, 4% FeSO4, and normal media, respectively. The accuracy and precision were confirmed valid, as all values were within the requirements and did not change during dilution. Then, this approach was successfully applied to determine the levels of DFP in NP-IR integrated into DMNs.

Superior photocatalytic degradation of pharmaceuticals and antimicrobial Features of iron-doped zinc oxide sub-microparticles synthesized via laser-assisted chemical bath technique

Addressing the dual challenges of antimicrobial resistance and pharmaceutical contamination in wastewater is crucial for global health and environmental preservation. Predictions estimate up to 10 million annual deaths by 2050 due to antimicrobial resistance, underscoring the urgent need for innovative solutions. This study explores the potential of zinc oxide Sub-Microparticles (ZnO SMPs) doped with iron (Fe) to enhance the photocatalytic degradation of pharmaceutical compounds in water and improve antimicrobial efficacy. A green laser-assisted chemical bath synthesis method created ZnO SMPs with varying Fe dopant concentrations (1 %, 1.5 %, and 3 %). The synthesized Sub-Microparticles underwent rigorous structural analysis using X-ray diffractometry, SEM, EDX, FTIR, and UV–visible spectrophotometry techniques. Their photocatalytic performance was evaluated in the degradation of paracetamol under blue laser light, and their antimicrobial properties were assessed following CLSI guidelines. Structural analyses confirmed the hexagonal wurtzite structure of ZnO SMPs, with noticeable changes due to Fe doping, including a transition from sub-microrods to sub-microsheets and a redshift in the optical band gap. Photocatalytic tests revealed a significant enhancement in paracetamol degradation efficiency, increasing from 53.41 % with pure ZnO to 98.99 % with 3 % Fe-doped ZnO in 50 min. Antimicrobial assays demonstrated an increased inhibitory effect against pathogens, with Fe-doped ZnO outperforming control discs. This study substantiates the potential of Fe-doped ZnO SMPs in wastewater treatment and antimicrobial applications, showcasing significant improvements in photocatalytic degradation of pharmaceutical compounds and antimicrobial efficacy. The findings underscore the importance of continuing research in this domain for environmental and public health benefits.

Effect of Iron Nanoparticles Prepared from Onion Extract on Cucumber Plant Growth and Production

In recent years, it has been shown that the use of chemical fertilizers negatively affects the environment and public health. Nano fertilizer have been discovered and used, and one of their many advantages is the speed and ease of obtaining them from various plant sources, which are cheap and currently available it's friendly for environment. The field experiment was carried out in the spring season of 2021 in a mixture of salty clay (cohesive soil) for the purpose of studying the effect of spraying synthetic nanoparticles used from iron oxide particles with onion plant extract at concentrations of 100, 200 and 300 parts per million on the growth and yield of cucumber (Cucumis melo var. flexuosus). The prepared nanoparticles were identified by the following assays: UV-visible spectrophotometry, XRD, FTIR, TEM, SEM and AFM. The results showed a significant effect of using Nano pesticides, especially with high concentration, in increasing average plant height, plant dry weight, leaf area and total plant yield. It was concluded from this study that the positive effect of Nano-fertilizer prepared with onion extract on plant growth, which led to an increase in cucumber productivity and the quality of its fruits, from that there is the possibility of using it as an alternative to conditional mineral fertilizers, after conducting several studies on the safety of using these plants treated with Nano-fertilizers for humans.

Synthesis and Characterization of MnO2 nanoparticles mediated by Raphia hookeri seed

In this study, managanese dioxide nanoparticles (MnO2-NP) was synthesized. Raphia hookeri seed was used as a bioreductant for the synthesis of MnO2-NPs. The biosynthesized MnO2-NPs was investigated for their reaction, structure and morphology. The MnO2-NPs was characterized using the UV-Visible spectrophotometry, Fourier Transform Infrared Spectrophotometry (FTIR), Energy Dispersive Spectrometry (EDX), Powdered X-ray Diffractometry (PXRD), Scanning electron microscpopy (SEM) and Transmission Electron Microscopy (TEM). UV-Visible spectra revealed that MnO2-NPs showed maximum 421nm respectively. FTIR results showed prominent reactive functional groups for hydroxyl (-OH) and carbonyl (-C=O). The EDX results revealed the elemental composition in percentages of the elements in the nanoparticles. PXRD revealled that the manganese dioxide nanoparticle is in a crystaline state. The morphology of the synthesized nanoparticle was found irregular and with porous surface for SEM. The average particle size of the nanoparticles as characterized by TEM was found to be 3.92 nm.

Clove mediated synthesis of Ag-ZnO doped fucoidan nanocomposites and their evaluation of antibacterial, antioxidant and cytotoxicity efficacy study

The Ag-ZnO/Fu nanocomposites were successfully synthesized in an environmentally friendly manner using an aqueous Clove buds extract from the Syzygium aromaticum plant. They were then examined for antibacterial activity against bacterium strains of Escherichia coli, Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Enterococcus faecalis. The UV–Visible spectrophotometry analysis confirmed the presence of zinc oxide (ZnO) nanoparticles at 334 nm, silver oxide (Ag) nanoparticles at 416 nm, and fucoidan at 589 nm in the synthesized nanocomposites. The FT-IR analysis confirmed the presence of five different functional linkages in the synthesized nanocomposites. The positions of diffraction peaks in pure Ag-ZnO/Fu nanocomposite patterns were identified using XRD analysis. The Ag-ZnO/Fu nanocomposites synthesized are more crystalline (77 %), and less amorphous (22.2 %). Silver, O, and Zn signals were detected in the SEM and EDX spectra of the Ag-ZnO/Fu nanocomposite. Different strains of Ag-ZnO/Fu nanocomposites showed stronger antibacterial properties. The DPPH technique was used to perform the antioxidant assay. Cytotoxicity testing was carried out on zebrafish embryos treated with several groups of Clove Ag ZnO/Fucoidan. The combination Ag-ZnO/Fucoidan (300 mg/mL) showed a marginally significant difference in survival (94 %).

Effectiveness of activated carbon from rubber seed shell as adsorbent of liquid waste of heavy metal

Iron or Fe is classified as a metal that has low toxicity, but if the concentration exceeds the quality standard, it can potentially cause pollution to the environment. This study aims to make activated carbon from rubber seed coat shells as an adsorbent for artificial Fe liquid waste using Fe2(SO4)3. 05 grams of activated carbon was activated using a ratio of 2:1, 3:1, 4:1 (NaOH: charcoal), and then an FTIR test was carried out to see the characteristics of the activated carbon. Measurement of Fe concentration using UV-VIS spectrophotometry, with various concentrations of 1, 1.5, 2, 2.5, 3, 4, 6, and 10 mg/L. After that, an analysis of the effect of contact time with the addition of activated carbon as an adsorbent for heavy metal Fe liquid waste was carried out, using variations of 05, 10, 15, 20, 30, 45, 90, and 120 minutes. An analysis of the effect of Fe concentration, with various concentrations of 10, 20, 30, 40, and 50 mg/L. Obtained from the linear equation of the calibration curve y = 0.0679x - 0.0013 with a correlation coefficient of 0.9996. The results of the third FTIR test showed that the ratio of NaOH and carbon activators did not change significantly. The functional groups that appeared were O-H, C=O carboxylate, C-C-C, aromatic C-H, aromatic C=C, C-O, and Si-O. Activated carbon 2:1, 3:1, and 4:1 have an absorption percentage of 86.72%, 89.45% and 96.37%. The greatest absorption efficiency is at a ratio of 4:1, optimum at 90 minutes. Sample 2:1 has an adsorption capacity of 0.163 mg/g, sample 3:1 of 0.259 mg/g, and 4:1 of 1.340 mg/g. The greatest adsorption capacity of activated carbon is at a ratio of 4:1, adsorption occurs physically (Freundlich) with a multilayer layer.

Green synthesis of reduced graphene oxide using Persea americana mill. extract: Characterization, oxygen reduction reaction and antibacterial application

Reduced graphene oxide (rGO) has garnered tremendous attention due to its salient properties that make it applicable in various electrochemical and environmental remediation fields. However, the commonly used chemical method to obtain rGO from graphene oxide (GO) involves toxic chemicals making both the process and product toxic and expensive. In the present work, the suitability of Avocado (Persea americana Mill) seed extract to reduce as-synthesized GO to rGO was investigated fully by optimising the reducing parameters such as the pH, temperature, amount of extract and reduction time. The formation of rGO from GO was confirmed with UV–Vis spectrophotometry (UV–Vis), Fourier Transform Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and the thermogravimetric analysis (TGA). The optimal conditions for reducing GO with avocado seed extract are pH 8, 100 °C, and 12 h. The average thickness and width for the rGO was 5.55 nm and 11.39 nm accordingly. While GO exhibited a ζ of −29.9.3 mV, the reduced GO possessed a − 38.2 mV. Calculations from the Kotouckey-Levich's equation demonstrated that the obtained rGO can potentially be applied as an oxygen reduction reaction (ORR) catalyst for the generation of hydrogen peroxide since it follows a 2e− pathway mechanism where hydrogen peroxide is generated as an intermediate. Additionally, the avocado seed extract reduced GO demonstrated a slight growth inhibition of methicillin resistant S. aureus (MRSA).

Biogenic PAG-FeNPs from Prunus armeniaca (Gum) as robust colorimetric sensors for methyl orange detection

Biogenic synthesis of nanoparticles is an emerging research area of the scientific community holding versatile and potential applications. The nanoscaled iron nanoparticles (FeNPs) have unique chemical and physical properties. Beside the available physical and chemical methods, the aqueous extract of the Prunus armeniaca Gum (PAG) was employed to promote a green and sustainable approach for the synthesis of FeNPs. The structure and morphology of the FeNPs were characterized by SEM, FTIR, and XRD techniques. And UV–Vis spectrophotometry is employed to study optical properties, time, temperature, and pH dependent stability. Herein PAG-FeNPs has been employed as efficient and cost-effective colorimetric probe for the sensing of methyl orange (MO) for the first time displaying a color change from light orange to dark voilet on exposure to MO. The selectivity of the detection method for MO against various interferences including heavy metals, and organic dyes was examined and sensor’s signal remained unaffected by common interferences. Under ideal detection conditions, the proposed method demonstrates an excellent linear correlation (R2 = 0.992) in the concentration range of 10–350 µM methyl orange. The limits of detection and limit of quantification are 13 µM and 40 µM, respectively. Moreover, the technique has been successfully employed for detecting methyl orange in self-contaminated tape water samples.

Removal of cadmium and zinc by calcium polysulfide in acidic groundwater: Injection ratio and precipitation mechanism

In this study, we conducted lab-scale experiments to assess the applicability of calcium polysulfide (CPS) for the removal of cadmium (Cd2+) and zinc (Zn2+) from acidic groundwater, with an emphasis on the injection ratio and removal mechanism. For the experiments, CPS was used to treat Cd2⁺ and Zn2⁺ contaminated solution. Solutions were purged with nitrogen gas, and CPS was injected in an anaerobic chamber. After 18 h, solutions were filtered, and heavy metal concentrations were measured using ICP-MS and ICP-OES. Total polysulfide (Sx2⁻) concentration in CPS was determined by converting it to bisulfide (HS⁻) at pH 8.20 and quantifying via UV–Vis spectrophotometry. Precipitates were analyzed using XRD and SEM-EDS after centrifugation. The findings revealed that more than 99.5% of the heavy metals were removed when CPS/Cd2+ (w/w) = 1.45 and CPS/Zn2+ (w/w) = 2.50, determined as the injection ratios for maximum efficiency. These ratios were applicable when Cd2+ and Zn2+ coexisted. From the XRD and SEM-EDS analyses, it was clarified that Cd2+ and Zn2+ precipitated in sulfide forms, consistently showing the preferential precipitation of Cd2+ because of the lower solubility of cadmium sulfide compared to zinc sulfide. In addition, the concentration of Sx2− in the 29% CPS solution was determined to be approximately 2.442 M. Finally, by comparing the injected Sx2− concentration with the concentration of heavy metals removed accordingly, it was concluded that CPS and heavy metals react with a 1:1 M ratio. Based on the above results and precise quantification method, our study suggests that CPS can be effectively utilized to address heavy metal contamination issues and may serve as a valuable tool for the remediation and management of contaminated groundwater globally.

Development and Optimization of a Bromothymol Blue-Based PLA2 Assay Involving POPC-Based Self-Assemblies.

Phospholipase A2 (PLA2) is a superfamily of phospholipase enzymes that dock at the water/oil interface of phospholipid assemblies, hydrolyzing the ester bond at the sn-2 position. The enzymatic activity of these enzymes differs based on the nature of the substrate, its supramolecular assemblies (micelle, liposomes), and their composition, reflecting the interfacial nature of the PLA2s and requiring assays able to directly quantify this interaction of the enzyme(s) with these supramolecular assemblies. We developed and optimized a simple, universal assay method employing the pH-sensitive indicator dye bromothymol blue (BTB), in which different POPC (3-palmitoyl-2-oleoyl-sn-glycero-1-phosphocholine) self-assemblies (liposomes or mixed micelles with Triton X-100 at different molar ratios) were used to assess the enzymatic activity. We used this assay to perform a comparative analysis of PLA2 kinetics on these supramolecular assemblies and to determine the kinetic parameters of PLA2 isozymes IB and IIA for each supramolecular POPC assembly. This assay is suitable for assessing the inhibition of PLA2s with great accuracy using UV-VIS spectrophotometry, being thus amenable for screening of PLA2 enzymes and their substrates and inhibitors in conditions very similar to physiologic ones.

β-Cyclodextrin-Modified Cotton Fabric for Medical and Hospital Applications with Photodynamic Antibacterial Activity Using Methylene Blue

The use of cyclodextrins in textiles for the development of biofunctional fabrics represents an interesting alternative for the advancement of dental, medical, and hospital materials. Cyclodextrins can interact with the chemical groups present in cotton fibers, leading to the formation of a nanostructured surface with specific functional properties, including antibacterial activity. Although there are numerous antibacterial textile finishes, the use of methylene blue as a cyclodextrin host molecule for photodynamic applications in textile materials remains to be investigated. This is because methylene blue is a photosensitive dye capable of generating singlet oxygen (1O2) when illuminated, which inactivates the pathogenic microorganisms that may be present in wounds. The objective of this study was to develop a biofunctionalized and photoactivatable cotton fabric with antimicrobial properties for use in the cosmetic or medical industries. The materials obtained were characterized via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), the determination of cotton fabric functionalization dyeing variables, colorimetry, UV-VIS spectrophotometry, degradation of 9,10-anthracenediyl-bis(methylene)dimalonic acid (ABDA), photodegradation tests, and microbiological analysis. The results showed that the textile was functionalized with β-cyclodextrin, mainly evidenced by the appearance of the band at 1730 cm−1, indicating the formation of the ester group. Thus, when exposed to light, the non-functionalized material showed greater photobleaching, about 60%, compared to the material treated with cyclodextrin. This result was also reflected in the ABDA degradation kinetics, with the treated material showing 592.00% (first phase) and 966.20% (second phase) higher degradation than the untreated sample. Finally, the photodynamic activity was determined based on the antimicrobial properties of the textile, showing a reduction of more than 99% without exposure to light and 100% when exposed to light. It is believed that this study could open avenues for future research and the development of antimicrobial fabrics, as well as demonstrate the efficiency of the treatment with cyclodextrin in relation to photobleaching.

Study on the Synthesis of BTA@MSNs Nanocarriers

Abstract Mesoporous silica, characterized by its adjustable pore size, uniform distribution, stable structure, and non-toxicity, is widely used as an encapsulating material for corrosion inhibitors. This study initially established that, compared to the high-temperature calcination method, the removal of surfactants via the solvent extraction method yields mesoporous silica with uniform size and better dispersibility. Results from N2 adsorption-desorption tests indicated that the mesoporous silica prepared by the solvent extraction method had an average pore diameter of 2.41 nm, a volume of 0.42 cc/g, and a specific surface area of 69.73 m2/g. SEM and TEM analyses showed that the BTA@MSNs nanoparticles synthesized via a one-step method were approximately 100 nm in size, whereas those prepared by the vacuum loading method were about 50 nm, both exhibiting ordered mesoporous structures. UV-vis spectrophotometry results revealed that the loading capacity of BTA in the nanoparticles produced by the one-step synthesis method was significantly lower than that in the BTA@MSNs nanoparticles prepared via the vacuum impregnation method.

Investigate the utilization of novel natural photosensitizers for the performance of dye-sensitized solar cells (DSSCs)

Dye-sensitized solar cells (DSSCs) offer a promising route for sustainable energy conversion, with natural photosensitizers emerging as attractive alternatives to conventional synthetic dyes due to their abundant resources, cost-effectiveness, and eco-friendly materials. However, the efficiency of DSSC utilizing natural photosensitizer remains low. In this study, we investigate the utilization of novel natural photosensitizers extracted from gambier leaves, gambier branches, cinnamon, and petiole of tectona leaves, which contain flavonoids/tannins, chlorophyll, and anthocyanins, aiming to achieve high-performance DSSCs. Five different solvents—ethanol, isopropanol, distilled water, methanol, and Zamzam water—are explored to optimize the extraction process of the natural dyes. The doctor blade technique is employed to coat TiO2 nanomaterials onto ITO glass substrates. UV–Vis spectrophotometry and FTIR spectroscopy are used to characterize the optical properties and structural composition of the dyes, revealing that flavonoid/tannin groups are the primary compounds responsible for light harvesting. The DSSC performance is evaluated under a 30 W lamp, adjusted to light intensity of 10 mW/cm2. As a result, the DSSCs using gambier leaf extract as photosensitizer demonstrate the highest recorded efficiency of 4.71 %, with a Jsc of 2.95 mAcm−2 and a Voc of 0.64 V. These findings contribute to advancing DSSC technology by leveraging the potential of natural photosensitizers for sustainable energy conversion applications.

Insights into the Structural and Thermal Properties of Pepsin-Soluble Collagen from Daggertooth pike conger (Muraenesox cinereus)

Pepsin soluble collagen (PSC) is a type-1 collagen which is abundant in skin. The pepsin soluble collagen was successfully extracted from the skin of Daggertooth pike conger (Muraenesox cinereus) by using the conventional method of salt precipitation followed by dialysis. Pepsin-soluble collagen showed a yield of 10.12% on wet matter basis and 25.5% on dry matter basis. The triple helical structure of collagen was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) and UV-Visible spectrophotometry. Isolated PSC was confirmed as type 1 collagen by Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). FTIR spectra of PSC suggested that the secondary structure of the triple helical collagen was intact even after pepsin digestion. Pepsin-soluble collagen was soluble in acidic pH with maximum solubility at pH 4. The solubility was found to be decreased with an increase in the concentration of sodium chloride with a minimum solubility at 4%. The present PSC isolate from eel fish exhibited comparatively high thermal stability of 36 ͦ C. Morphological analysis by Scanning electron microscopy (SEM) revealed a porous structure and comparatively high thermal stability makes it a promising biomaterial.

In Vitro Evaluation of Prebiotic Potential of Red Ginger (Zingiber officinale var. rubrum) Rhizome Ethanol Extract on Lactobacillus acidophilus and Escherichia coli

Prebiotics, including carbohydrates and phenols, promote beneficial gut bacteria (probiotics). Red ginger (Zingiber officinale var. rubrum) rhizomes, rich in these compounds, have been traditionally used in medicine but their prebiotic potential remains unexplored. This study investigated the in vitro prebiotic effects of Z. officinale var. rubrum rhizomes on Lactobacillus acidophilus (beneficial) and Escherichia coli (opportunistic) bacteria. Prebiotic activity was assessed using a turbidimetric method, measuring bacterial growth via UV-Vis spectrophotometry at 600 nm. The prebiotic index and percentage inhibition were calculated to evaluate the impact on bacterial growth. Additionally, total phenol content was determined using the Folin-Ciocalteu method. Results indicate that Z. officinale var. rubrum rhizomes exhibit prebiotic properties, stimulating L. acidophilus growth (prebiotic index of 156.035 and percentage inhibition value of -153.128%) while inhibiting E. coli growth (54.343% inhibition). The rhizomes contained 31.15 mg GAE/g extract of total phenols and 23.55% carbohydrates. These findings suggest that Z. officinale var. rubrum rhizomes possess prebiotic potential, warranting further investigation for potential applications in gut health management.

Detecting dissolved mercury(ii) ions using chitosan-AgNP strips integrated with smartphones.

A simple preparation of a paper strip test with a smartphone-based instrument for detecting dissolved mercury is still in development. This study aims to develop a smartphone-based colorimetric paper strip test using chitosan-stabilized silver nanoparticles for detecting dissolved mercury. The method demonstrated high sensitivity and selectivity for Hg2+ ions, with detection limits comparable to UV-vis spectrophotometry. Silver ions embedded in the chitosan matrix were reduced by either sodium NaBH4 or N2H4. Both chi-AgNP colloidal and chi-AgNP paper strips were tested for sensitivity of mercury(ii) solution detection with and without ion interference. The accuracy of colour change responding to the mercury concentration was recorded with several smartphones in a handmade cubical and a T-shape micro-studio. Only NaBH4 gives colloidal chi-AgNPs relatively dispersed, and the colloidal chi-AgNPs become aggregated when AgNP interacts with mercury(ii) ions. The colour change of chi-AgNP paper strips responding to the concentration of mercury(ii) and quantified using a smartphone is consistent when confirmed with UV-vis spectrophotometric determination with a comparable limit of detection (0.76 μM). The inferring ions do not significantly affect mercury(ii) analyses. Therefore, the paper strip integrated with the smartphone is effectively used for mercury(ii) detection in water as long as the mercury concentration is >1 μM. This finding might inspire advanced technology with a larger number of data references, and machine learning involvement to develop more compatible and simple mercury detection.

Potential and Activities of the Sunscreen Lotion Preparation of Bawang Dayak (Eleutherine americana (Aubl.) Merr. by Ethanol Extract Fraction from East Boneo

Has conducted research Potential and Activities of the Sunscreen Lotion of Bawang Dayak (Eleutherine americana (Aubl.) Merr. by ethanol extract fraction from East Borneo. The purpose of the study was to determine the potency ann activity of the sunscreen ethanol extracts fraction of Bawang Dayak in the preparation of a lotion with the parameter measuring the percent transmission erythema (% Te) and pigmentation (% Tp) in vitro in the room temperature 27oC storage and accelerated temperature 40oC. Lotion dosage formulations using ethanol extracts fraction bawang Dayak with a concentration of 0.1% and 0.2%, and positive control is a trademark preparation Bless Sunscreen Lotion SPF 15®. Stages of research include the formulation and measurement of absorbance and value %Te) and %Tp at various storage temperatures with UV-Vis spectrophotometry at λ 292.5 to 372.5 nm. The analysis of research data using a program SPSS. The results showed that ethanol extract fraction concentration in lotion preparations of bawang Dayak 0.1% and 0.2% active as a sunscreen included in the category of sunblock. The extract fraction is active as a sunscreen and in the Sunbloc category, with the best concentration as a sunscreen being 0.2%, with its sunscreen potential not being significantly different from the control Sunscreen SPF 15® at the 5% level.

A detailed methodology for estimating health-related hazards of workplace exposure to indoor formaldehyde vapours

A comprehensive risk assessment method was applied to examine the risks associated with airborne formaldehyde occupational exposure among hospital laboratory staff. The method assessed exposure levels and health impacts by integrating area and personal air sampling, biological monitoring, and self-reported health data. Samples were collected from 74 workplaces across various departments using NIOSH method 3500 and were analyzed via UV-vis spectrophotometry. The data showed significant differences in exposure levels between departments (p≤0.05) and confirmed the efficacy of the method in identifying risk differences. Despite average personal exposure levels being measured lower than occupational limits, individual assessments indicated that some participants surpassed these limits, emphasizing the necessity of personal monitoring for workers with higher risks. The high prevalence of respiratory symptoms, such as cough and wheezing among staff, indicated the need for further investigation and targeted interventions. Although estimated cancer and non-cancer risks were within safe thresholds, the study emphasized the importance of continuous exposure monitoring and the implementation of effective control measures in hospital laboratory departments with formaldehyde emission. This integrated method improved the reliability and generalizability of formaldehyde exposure risk assessments and aided in the development of safe occupational health practices.•The method integrated personal and area sampling with advanced calibration for precise occupational exposure evaluation in laboratories.•The method used of biomarkers to assess formaldehyde absorption in the body estimating both cancerous and non-cancerous health risks associated with occupational exposure.•Addressed traditional method limitations and integrated risk components to improve data reliability for workplace safety and health risk management.

Arabidopsis Dph4 is an Hsp70 Cochaperone with Iron-Binding Properties.

J-domain proteins (JDPs) are obligate cochaperones of Hsp70s with a wide range of functions in protein homeostasis. Although the J-domain is required for the stimulation of Hsp70s ATPase activity, the functional specificity of JDPs is governed by domains or regions other than the J-domain. Jjj3/Dph4, a class III JDP, is required for diphthamide (DPH) biosynthesis in eukaryotes, including yeast and mammals. Dph4 has a conserved N-terminal J-domain and an uncharacterized C-terminal domain containing a signature CSL zinc finger motif. Previously, we showed that the Dph4 ortholog in Arabidopsis thaliana (atDjC13/AtJjj3/AtDph4) could restore DPH biosynthesis in yeast jjj3Δ mutant in a J-domain-dependent manner. Here, we characterize the C-terminal CSL motif of AtDph4 using yeast genetic and biochemical approaches. The CSL motif of AtDph4 is essential for DPH biosynthesis, and like human Dph4, AtDph4 showed distinct iron-binding activity, which is not present in its yeast counterpart. ScDph4 and AtDph4 proteins exhibit distinct iron-binding capabilities, as evidenced by UV-vis spectrophotometry, SEM-EDS (energy-dispersive spectroscopy function on the scanning electron microscope) and electron paramagnetic resonance (EPR) spectra analyses. Collectively, our data suggests that beyond their role as an Hsp70 cochaperone, Dph4 homologues in complex eukaryotes may have iron-binding abilities, indicating a potential role in iron-sulfur cluster assembly and iron homeostasis.