Refinar búsqueda
Resultados 1-10 de 14
Alterations in juvenile diploid and triploid African catfish skin gelatin yield and amino acid composition: Effects of chlorpyrifos and butachlor exposures
2016
Karamī, ʻAlī | Karbalaei, Samaneh | Zad Bagher, Fariba | Ismail, Amin | Simpson, Stuart L. | Courtenay, Simon C.
Skin is a major by-product of the fisheries and aquaculture industries and is a valuable source of gelatin. This study examined the effect of triploidization on gelatin yield and proximate composition of the skin of African catfish (Clarias gariepinus). We further investigated the effects of two commonly used pesticides, chlorpyrifos (CPF) and butachlor (BUC), on the skin gelatin yield and amino acid composition in juvenile full-sibling diploid and triploid African catfish. In two separate experiments, diploid and triploid C. gariepinus were exposed for 21 days to graded CPF [mean measured: 10, 16, or 31 μg/L] or BUC concentrations [Mean measured: 22, 44, or 60 μg/L]. No differences in skin gelatin yield, amino acid or proximate compositions were observed between diploid and triploid control groups. None of the pesticide treatments affected the measured parameters in diploid fish. In triploids, however, gelatin yield was affected by CPF treatments while amino acid composition remained unchanged. Butachlor treatments did not alter any of the measured variables in triploid fish. To our knowledge, this study is the first to investigate changes in the skin gelatin yield and amino acid composition in any animal as a response to polyploidization and/or contaminant exposure.
Mostrar más [+] Menos [-]Dissolution of metal and metal oxide nanoparticles in aqueous media
2014
Odzak, Niksa | Kistler, David | Behra, Renata | Sigg, Laura
The dissolution of Ag (citrate, gelatin, polyvinylpyrrolidone and chitosan coated), ZnO, CuO and carbon coated Cu nanoparticles (with two nominal sizes each) has been studied in artificial aqueous media, similar in chemistry to environmental waters, for up to 19 days. The dissolved fraction was determined using DGT (Diffusion Gradients in Thin films), dialysis membrane (DM) and ultrafiltration (UF). Relatively small fractions of Ag nanoparticles dissolved, whereas ZnO dissolved nearly completely within few hours. Cu and CuO dissolved as a function of pH. Using DGT, less dissolved Ag was measured compared to UF and DM, likely due to differences in diffusion of organic complexes. Similar dissolved metal concentrations of ZnO, Cu and CuO nanoparticles were determined using DGT and UF, but lower using DM. The results indicate that there is a need to apply complementary techniques to precisely determine dissolution of nanoparticles in aqueous media.
Mostrar más [+] Menos [-]Indoor and outdoor microbial aerosols at the holy mosque: A case study
2015
Mashat, Bassam
The aim of this study was to evaluate bacterial and fungal aerosol concentrations at the holy mosque (Al-Masjid Al-Haram). Air samples were collected from different locations inside and outside the holy mosque, during the month of Ramadan-2011 (the fasting month), using a portable Air-port MD8 gelatin filter sampler. Trypticase soya agar and Capek's dox agar media were used to count bacteria and fungi, respectively. The mean concentrations of airborne bacteria and fungi ranged between 105–106 colony forming unit per cubic meter of air (CFU/m3) outside, and ∼102–105 CFU/m3 inside locations. The highest outside bacterial concentrations 106 CFU/m3 were found at the Al Umra, Al Fatah and eastern plazas, and the highest inside fungal concentrations ∼105 CFU/m3 were found at the courtyard, expansion of 1st floor, and roof. Significant differences (P < 0.05) were found between bacterial and fungal concentrations inside and outside sampling locations, higher concentrations shifted towards to outside locations. Significant differences were also found between the bacterial and fungal concentrations inside–unclosed and semi-closed (P < 0.05) with inside-closed locations. Gram-positive bacteria, Bacillus and Micrococcus, and fungi, Aspergillus niger were the dominant microbial aerosol genera. The obtained data is considered a step to make up the gap about airborne microbial contamination inside the holy mosque, and microbial air quality should be studied along over the year at the holy mosque in the future.
Mostrar más [+] Menos [-]Fusarium sp. L-asparaginases: purification, characterization, and potential assessment as an antileukemic chemotherapeutic agent
2022
Al Yousef, Sulaiman A.
Asparaginases important role in the treatment of leukemia. It is part of chemotherapy in the treatment of leukemia in the last three decades. L-Asparaginase is isolated from Fusarium sp. isolated from soil and purified using ammonium sulfate precipitation and Sephadex G 100. Characterization of the crude enzyme revealed it is a metalloprotease inhibited by EDTA. Hg²⁺, Cd²⁺, and Pb²⁺ also inhibited the enzyme. Mg²⁺, Zn²⁺, and Ca²⁺ activated L-asparaginase. Furthermore, kinetic studies of purified enzyme were carried out. Vₘₐₓ and Kₘ were 0.031 M and 454 U/mL, respectively. The optimum temperature was 30 °C and the optimum pH was 7. Concerning substrate specificity, gelatin and casein in addition to L-asparagine were tested. The enzyme was found to be nonspecific that could hydrolyze all tested substrates at different rates. The maximum enzyme activity was recorded in the case of L-asparagine, followed by casein and gelatin, respectively. The molecular weight of L-asparaginase was 22.5 kDa. The antileukemic cytotoxicity assay of the enzyme against RAW2674 leukemic cell lines by MTT viability test was estimated. The enzyme exhibited antileukemic activity with IC₅₀ of 50.1 UmL⁻¹. The current work presents additional information regarding the purification and characterization of the enzyme produced by Fusarium sp. and its evaluation as a potential antileukemic chemotherapeutic agent.
Mostrar más [+] Menos [-]Grafted PVDF Particles for Efficient Removal of Trace Lead (II) Ions in Aqueous Solution
2021
Lei, Yihao | Jin, Kaihao | Lin, Xing | He, Liyin | Wu, Yinqiu | Zhang, Jianfeng
To improve the water quality, a new type of grafted poly(vinylidene fluoride) (PVDF) particles was designed and synthesized to adsorb trace Pb²⁺ in water. Through the surface hydroxylation of PVDF particles, followed by the sequential coupling of gelatin, β-cyclodextrin (β-CD) and acrylic acid (AA) provide grafted PVDF particles (PAGCA) with multi-functionalized groups. The newly prepared PAGCA particles were characterized by FT-IR, XPS, and SEM. The results show that the PAGCA particles have excellent adsorption performance for Pb(II) in water and can remove Pb(II) rapidly and thoroughly with a removal rate of 100%. The adsorption capacity of PAGCA particles increased with the increase of solid–liquid ratio or pH value. The good adsorption performance of PAGCA particles was also demonstrated by completely removing 2.37 μg/L of Pb(II) from a river water sample. XPS and SEM analysis further confirmed the formation and adsorption of Pb(II) on the surface of PAGCA particles. The synthesized PAGCA particles also show good adsorption ability to cadmium(II) with a removal rate of 93.6% in single ionic water and 87.9% in river water, respectively. It is concluded that the combination of hydroxyl group, carboxyl group, and amino group on the surface of the new grafted PVDF particles greatly improves the adsorption capacity of PVDF particles for Pb²⁺, and it has a good application prospect in the removal of trace Pb(II) in water.
Mostrar más [+] Menos [-]Preparation of Photo/Electro-Sensitive Hydrogel and Its Adsorption/Desorption Behavior to Acid Fuchsine
2020
Xing, Jianyu | Yang, Bin | Dang, Wenwen | Li, Jingchang | Bai, Bo
Macroscopic utilization of nanomaterial provides a new idea for the research and development of novel adsorbent, which can enhance efficiency in the adsorption and elution process. In this paper, nano-polypyrrole (PPy) was dispersed into two inexpensive and renewable biomass materials, gelatin (Gel) and chitosan (CS), to fabricate a novel photo/electric-sensitive hydrogel, Gel/CS/PPy. The micro-network of Gel/CS/PPy shows a high adsorption rate of 94.2% for acid fuchsine (AF). Furthermore, with the addition of polypyrrole, Gel/CS/PPy has the characteristic of photo/electric response, which can improve the elution efficiency of AF from the adsorbent. The results showed that the elution efficiency could be increased by 4 times with photo-assistance, and about 2 times with electro-assistance. Predictably, using the methods described in this article, high-quality adsorbents can be designed for more organic pollutants. Graphical abstract
Mostrar más [+] Menos [-]A natural post-emergence herbicide based on essential oil encapsulation by cross-linked biopolymers: characterization and herbicidal activity
2020
Taban, Azin | Saharkhiz, Mohammad Jamal | Naderi, Ruhollah
This work describes efforts to encapsulate savory (Satureja hortensis L.) essential oil (EO) with different natural polymers (i.e., Arabic gum/gelatin (AGG), apple pectin (AP), gelatin (G)) and, as a separate set of experiments, with bio cross-linkers (i.e., citric acid and transglutaminase enzyme). The phytotoxic activity of encapsulated savory EO on tomato (Lycopersicon esculentum Mill.) and amaranth weed (Amaranthus retroflexus L.) was investigated. The micro-capsules were evaluated in terms of size, polydispersity, stability, encapsulation efficiency, morphology, and release properties. The Korsmeyer–Peppas model operated when EO was being released from the micro-capsules. Carvacrol (52.5%) and γ-terpinene (30.2%) comprised the main constituents of the savory EO. Based on the results, encapsulating the EO with cross-linked biopolymers increased the stability and herbicidal activity of EO, as compared to simple EO emulsions. Maximum toxicity injuries (MTI) were caused by encapsulations of apple pectin, cross-linked with APe enzyme (15 ml/L) on both plant species. MTI were observed 2 days after using the micro-encapsulated herbicides (MCHs). However, the injury caused by MCHs on tomato was not significant. The lowest values of fresh weight (2.80 g), chlorophyll a (0.194 mg/g Fw), and total chlorophyll content (0.219 mg/g Fw) of amaranth occurred in response to APe (15 ml/L). Moreover, using AP(e) (10 ml/L) caused the lowest values of starch (0.444 mg/g Fw) and flavonoid contents (4.18 mg Cat/g Fw) in amaranth which measured as 59% and 90% reductions, respectively, in comparison with the control. The highest values of MDA (0.0109 nmol/g Fw) and H₂O₂ (0.0432 μmol/g Fw) were observed in amaranth plants treated with AP(e) (10 ml/L). In summary, cross-linked apple pectin can perform well in slow release delivery systems of agrochemicals. It can be recommended for use in the production of commercial, EO-based natural herbicides.
Mostrar más [+] Menos [-]Gelatin-Grafted Granular Composite Hydrogel for Selective Removal of Malachite Green
2015
Zheng, Yian | Zhu, Yongfeng | Wang, Feng | Wang, Aiqin
Featured with biodegradability and biocompatibility properties, gelatin (GE) was selected as the backbone to graft poly(acrylic acid) (PAA) to fabricate a granular hydrogel at room temperature in air. Using attapulgite (APT) as an inorganic component, the resulting GE-g-PAA/APT hydrogel was characterized by means of Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and zeta potential analysis and then used as the adsorbent to be applied in a mixed dye solution containing malachite green and orange G. The addition of APT can significantly reduce the swelling degree during the adsorption process, though its influences on the adsorption capacity are not so expectable. The as-prepared hydrogel shows a wide pH-independent adsorption from 3.0 to 10.0, with the maximum adsorption capacity of 1370 mg/g for GE-g-PAA and 1190 mg/g for GE-g-PAA/APT (5 wt%). More importantly, the as-prepared hydrogel shows high adsorption selectivity for cationic dyes and the dye-loaded hydrogel can be easily regenerated and recovered for successive adsorption cycles. Graphical Abstract Gelatin-based granular hydrogel for selective removal of MG in a mixed dyes containing MG and OG-G.
Mostrar más [+] Menos [-]The recycling of the expired donkey-hide gelatin pulp for N/S co-doped hollow carbon nano-spheres anode in sodium ion battery
2020
Liu, Xianxi | Yu, Chengyi | Hou, Hongying | Xu, Zhiyu | Meng, Kun | Zhu, Jing | Wang, Lei
How to reasonably manage and reutilize the waste expired liquid medicines has always been a puzzling public concern. For this reason, the waste expired medicine of donkey-hide gelatin pulp was recycled by hydrothermal carbonization and hard template for N/S co-doped hard carbon material, and its electrochemical Na-storage performances were also evaluated. The results showed that the resultant N/S co-doped hard carbon material manifested the morphology of hollow nano-spheres with the mean diameter of about 242.3 nm and the shell thickness of about 15 nm; N and S elements evenly distributed in carbon structure by in situ co-doping. Furthermore, N/S co-doped hard carbon also delivered the satisfactory electrochemical Na-storage capacities due to the synergistic effect of the unique hollow nano-spheres with thin shell and N/S co-doping. No doubt, the results would promote the circular economy mode of waste expired medicines.
Mostrar más [+] Menos [-]The influence of processing and clarifier agents on the concentrations of potentially toxic elements (PTEs) in pekmez (a grape molasses-like syrup)
2020
Heshmati, Ali | Ghadimi, Sabah | Ranjbar, Akram | Mousavi Khaneghah, Amin
The changes in some potentially toxic elements (PTEs) including lead (Pb), cadmium (Cd), arsenic (As), iron (Fe), zinc (Zn), and copper (Cu) during pekmez (grape molasses-like syrup) processing and the utilization of various types of clarifiers (white soil, bentonite, and gelatin) in two levels (1.5 and 3% w/w) were analyzed. The average concentrations of Pb, Cd, As, Fe, Zn, and Cu in grape samples were measured as 0.055 ± 0.005, 0.030 ± 0.002, 0.044 ± 0.002, 2.882 ± 0.013, 2.372 ± 0.088, and 1.194 ± 0.01 μg g⁻¹. During pekmez production, the range of changes in Pb, Cd, As, Fe, Zn, and Cu was −43.38% to 40.25%, −55.49% to 0.23%, −76.15% to 1.80%, −74.15% to 58.47%, −40.55% to −18.12%, and −83.16% to −21.39%, respectively. The effect of the clarification process on the PTEs depended on the type and concentration of both PTE and clarifier agent used while the incorporation of gelatin resulted in a significant reduction in all of PT. Graphical abstract
Mostrar más [+] Menos [-]