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Advances in the Applications of Clinoptilolite-Rich Tuffs
No full textAdsorptive, catalytic, and antibacterial properties of clinoptilolite-rich tuffs (ZT) are presented here. ZT transformed into Fe-containing ZT (Fe-ZT) removes various organic and inorganic anions from water. Fe-ZT, which contains selenium, is beneficial for growing Pleurotus ostreatus mushrooms. The fungi convert inorganic Se from Fe-ZT into a more useful organically bonded form. ZT and Fe-ZT as supplements retain nitrogen and potassium in sandy, silty loam and silty clay soils. ZT shows an affinity toward toxic metal cations, which are essential for cleaning contaminated water. The adsorption of atenolol, acetylsalicylic, and salicylic acid onto M-ZT (M–Cu2+, Mn2+, Ni2+, or Zn2+) from water solutions suggests that both the natures of M and pharmaceuticals have a significant impact on the adsorption mechanism and determine the adsorption capability of the ZT. ZT is an excellent carrier for ultrafine (2–5 nm) nano oxide particles, which have been shown to have catalytic activity in different chemical processes and photodegradation reactions of organic pollutants. ZT can also be transformed into SO4-SnO2-ZT, which is catalytically active as a solid acid. M-ZT is an effective carrier of valuable bacteria. Ag-ZT possesses beneficial bactericidal activity in disinfecting water and soil remediation
The Realm of Smart Biomass Degrading Enzymes in Low-Carbon Fuels and Chemicals Production
No full textDue to the depletion of fossil fuel sources and the issues posed by climate change, there is an increasing demand for renewable and sustainable fuel alternatives. Biofuels are a viable replacement for fossil fuels since they are made from renewable biomass. Degradation and valorization of renewable biomass start in the biorefinery with the main goal of producing biofuels and biochemicals in a more sustainable way. Lignocellulosic biomass (LB) presents one of the most abundant feedstocks for low-carbon fuel production. Enzymes belonging to cellulase, xylanase, pectinase, laccase, amylase, and lipase are utilized for biomass degradation and for the biofuels production. The emphasis of this chapter will be on the smart degrading enzymes designed to produce the two low-carbon biofuels, bioethanol and biodiesel, which are mostly used in the industrial sector. The technological development of commercial enzymes involved in biofuel and chemical production is also discussed.Part of the book series: Green Energy and Technology ((GREEN)
Green biocatalyst for decolorization of azo dyes from industrial wastewater: Coriolopsis trogii 2SMKN laccase immobilized on recycled brewerʼs spent grain
No full textThis study presents an innovative approach for the reuse and recycling of waste material, brewer’s spent grain (BSG) for
creating a novel green biocatalyst. The same BSG was utilized in several consecutive steps: initially, it served as a substrate
for the cultivation and production of laccase by a novel isolated fungal strain, Coriolopsis trogii 2SMKN, then, it was reused
as a carrier for laccase immobilization, aiding in the process of azo dye decolorization and fnally, reused as recycled BSG
for the second successful laccase immobilization for six guaiacol oxidation, contributing to a zero-waste strategy. The novel
fungal strain produced laccase with a maximum activity of 171.4 U/g after 6 days of solid-state fermentation using BSG
as a substrate. The obtained laccase exhibited excellent performance in the decolorization of azo dyes, both as a free and
immobilized, at high temperatures, without addition of harmful mediators, achieving maximum decolorization efciencies
of 99.0%, 71.2%, and 61.0% for Orange G (OG), Congo Red, and Eriochrome Black T (EBT), respectively. The immobilized
laccase on BSG was successfully reused across fve cycles of azo dye decolorization process. Notably, new green biocatalyst
outperformed commercial laccase from Aspergillus spp. in the decolorization of OG and EBT. GC-MS and LC-MS revealed
azo-dye degradation products and decomposition pathway. This analysis was complemented by antimicrobial and phytotoxicity tests, which confrmed the non-toxic nature of the degradation products, indicating the potential for safe environmental
disposal
Novel triphenyltin(iv) compounds with carboxylato N-functionalized 2-quinolones as promising potential anticancer drug candidates: in vitro and in vivo evaluation
No full textThree newly synthesized triphenyltin(iv) compounds, Ph3SnL1 (L1− = 3-(4-methyl-2-oxoquinolin-1(2H)-yl)propanoato), Ph3SnL2 (L2− = 2-(4-methyl-2-oxoquinolin-1(2H)-yl)ethanoato), and Ph3SnL3 (L3− = 2-(4-hydroxy-2-oxoquinolin-1(2H)-yl)ethanoato), were characterized by elemental microanalysis, FT-IR spectroscopy and multinuclear (1H, 13C and 119Sn) NMR spectroscopy. A single X-ray diffraction study indicates that compounds Ph3SnL1 and Ph3SnL2 exhibit a 1D zig-zag chain polymeric structure, which in the case of Ph3SnL2 is additionally stabilized by π-interactions. In addition, the synthesized compounds were further examined using density functional theory and natural bond orbital analysis. The compounds have been evaluated for their in vitro anticancer activity against three human cell lines: MCF-7 (breast adenocarcinoma), A375 (melanoma), HCT116 (colorectal carcinoma), and three murine cell lines: 4T1 (breast carcinoma), B16 (melanoma), CT26 (colon carcinoma) using MTT and CV assays. The IC50 values fall in the nanomolar range, indicating that these compounds possess better anticancer activity than cisplatin. The study of the effect of the newly developed drug Ph3SnL1 showed its plasticity in achieving an antitumor effect in vitro, which depends on the specificity of the phenotype and the redox status of the malignant cell line and ranges from the initiation of apoptotic cell death to the induction of differentiation to a more mature cell form. In the syngeneic model of murine melanoma, Ph3SnL1 showed the potential to reduce the tumor volume similar to cisplatin, but in a well-tolerated form and with low systemic toxicity, representing a significant advantage over the conventional drug
Use of sodium oxalate and calcium formate for chemical activation of high volume fly ash (HVFA) binders
No full textThis study investigates hydration mechanism of a high volume fly ash (HVFA) binder, comprising 70 wt% of fly ash (FA), chemically activated by using sodium oxalate (Na2C2O4) and calcium formate (Ca(HCOO)2). Prior to the binder synthesis, mechanical activation of FA was employed. Effects of the activators on the properties of the HVFA binders were determined by measuring setting times and compressive strength of the binders. Heat of hydration, pore solution composition, bound water and portlandite content, mineral composition, and microstructure of HVFA binder pastes were analyzed in order to compare the hydration mechanisms of the HVFA binders activated with the selected activators. The obtained results indicated that using of the two different activators led to the enhancement of the properties of the HVFA binders, but it was achieved in two distinct ways. It was found that the use of Ca(HCOO)2 mitigated adverse effects of the high alkalinity of the pore solution of chemically activated HVFA binder on hydration process and strength development in the later period. Therefore, it was concluded that Ca(HCOO)2 was more suitable for chemical activation of HVFA binders, compared to Na2C2O4
SSI of PLA-based surgical sutures with thymol
No full textDue to the high use and misuse of antibiotics over the years, microbes have developed resistance to a significant
number of drugs (so-called antimicrobial resistance - AMR) [1]. Therefore, the necessity for the development
of natural antimicrobial agents to overcome growing bacterial resistance against synthetic antibiotics has been
recognized. Thymol is a natural monoterpenoid, with proven anti-inflammatory, antioxidant, and antimicrobial
properties and it has been recognized as safe by the FDA (it has GRAS status).
With the aim to fabricate material with antibacterial activity, supercritical solvent impregnation (SSI) was
applied for loading of commercial PLA-based absorbable surgical sutures with thymol in a green medium,
supercritical CO2. Operating temperature and pressure were set to 35 °C and 10 MPa, while contact time was
varied between 1 and 6 h. The SSI process was performed under mild processing parameters to obtain an
effective amount of loaded thymol against tested bacteria keeping in mind the recommended safe content of
thymol for human blood cells (in terms of cytotoxicity and mutagen effect) [2]. Selected process conditions
enabled thymol loadings of 3.9–5.6% (Fig. 1) [3]. SEM analyses was used to monitor sutures' morphological
change from swelling to agglutination induced by the increased amount of thymol in the material. ..
Interference effect in surface modified ZnS nanoparticles / Poly (methylmethacrylate) nanocomposites
No full textSurface modified ZnS nanoparticles / poly (methylmethacrylate) - (PMMA) nanocomposites were prepared by the solution casting method. The ZnS nanoparticles, as starting materials in the present study, were synthesized mechanochemically and their crystallite size was estimated as 2.3 nm. Surface modification of obtained nanoparticles was performed by 3-Mercaptopropyltrimethoxysilane. We investigate thin samples of the nanocomposite material and pure PMMA (about 290 μm) with a strong interference effect, and corresponding thick samples, as reference. The optical properties of this material were studied by far-infrared spectroscopy. The analysis of the far-infrared reflectivity spectra was made by the fitting procedure, according to the model for a thin plate of nanocomposites in the air. The dielectric function of the nanocomposites was modeled as a mixture of homogenous surface modified ZnS spherical inclusions in PMMA, by the Maxwell-Garnet formula. In the case of a PMMA thin sample, intense, well-defined interference was registered in the range of 90 to 200 cm− 1, while significantly weaker and less well-defined interference was registered in the range around 450 cm− 1. In the thin composite sample, in addition to the interference induced by sample thickness, interference induced by the existence of ZnS nanoparticles was also observed, located between the TO and LO phonons of ZnS. This opens the possibility of applying nanocomposites in interferometry
PROCENA ZDRAVSTVENOG RIZIKA OD ELEMENATA RETKIH ZEMALJA U PODZEMNOJ VODI U BLIZINI TERMOELEKTRANE
No full textGroundwater serves as the primary source of drinking and agricultural water. Therefore, it is vital to ensure clean water supply to people. However, recently, anthropogenic activities led to groundwater degradation worldwide [1,2]. Activities related to thermal power plants, including coal fly ash and wastewater disposal, are one of them. Coal fly ash is known to contain significant amounts of contaminants, such as rare earth elements (REEs). Inadequate management of coal fly ash landfills may lead to the leaching of REEs from ash into groundwater, which can have a harmful effect on human health [3,4].
This study investigated both non-carcinogenic and carcinogenic health risk posed by REEs in groundwater near the larges thermal power plant in Serbia, namely Nikola Tesla power plant. A total number of sixteen samples were collected and analysed for sixteen REEs, including lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). The study encompassed both adults and children as population groups, examining ingestion and dermal pathways as primary exposure routes.
Non-carcinogenic risk for adults (HIa) was in the range of 1.1 × 10−4 – 1.4 × 10−4, averaging 5.2 × 10−4. Moreover, non-carcinogenic risk for children (HIc) ranged from 1.6 × 10−4 to 2.0 × 10−3, with an average value of 7.6 × 10−4. Children were more susceptible to non-carcinogenic risk compared to adults. Such results can be explained by the lower body weight of the children. None of the samples exceeded the threshold of 1 regarding both groups, suggesting negligible non-carcinogenic risk. Carcinogenic risks for adults (ILCRa) and children (ILCRc) were in the range of 2.0 × 10−18 – 2.7 × 10−17 and 8.1 × 10−18 – 1.0 × 10−17, with average values of 9.8 × 10−18 and 3.9 × 10−18, respectively. Adults were more prone to carcinogenic risk, as evidenced by the results. Both population groups had ILCR values within the threshold of 1.0 × 10−6, implying insignificant carcinogenic risk. In addition, ingestion through drinking water was identified as the main exposure route for both risk, while Sc showed the greatest contribution to both risk assessments.
Although REEs in groundwater do not pose a risk to human health, ongoing ash disposal may lead to an increase in health risk, therefore continuous monitoring of the area under study is advised
Corrosion Characterisation of Brazing Ag59Cu31Pd10 Alloy for Potential Dental Applications
No full textThis research addresses the corrosion behaviour of the Ag-based alloy with Pd as the component in three different corrosion environments: standard physiological saline solution (SS; 0.9% NaCl), Ringer’s solution (RS), and Fusayama's artificial saliva (AS) at 37 °C. The examination has a primary goal to evaluate the suitability of the alloy as dental material and is used following the electrochemical methods: open circuit potential (OCP), linear polarisation resistance (LRP), and Tafel extrapolation from the potentiodynamic measurement, which is a broad interval of anodic potential. Chemical analysis of the RS after recording a polarisation curve was also a significant part of the study. The results showed OCP values from 35 mV to 65 mV and polarisation resistance values (Rp) in the interval from 8.5 up to 19.3 kΩ×cm2. The most corrosive solution was RS, and the least was AS. The corrosion current density in AS was close to 1 μA×cm-2. Although the alloy, in AS particularly, has a relatively high Rp value and OCP close to the Ag alloys with a higher content of noble metals, it has low breakdown potential, which directly led to its classification as an unstable dental material for permanent use. The concentrations of the metals in RS were at ppb levels for Ag, tens of ppb for Pd, and 0.64 mg×dm-3 for Cu. Regardless of the unsatisfactory corrosion characteristics for the application, the paper showed good potential for the Ag-Cu-Pd system as a brazing filler for dental use and as an adequate control for similar studies
KORELACIJA STRUKTURE I POTENCIJALNE FARMAKOLOŠKE AKTIVNOSTI SPIROHIDANTOINA DOBIJENIH IZ α-TETRALONA
No full textHydantoin is a nonaromatic five-membered heterocycle, which is considered a valuable, privileged
scaffold in medicinal chemistry. The importance of the hydantoin scaffold in drug discovery
has been reinforced by several medicines in clinical use, such as anticonvulsants (phenytoin), antibiotics(nitrofurantoin), anticancer drugs (enzalutamide) and keratolytics (allantoin). To design new
potentially pharmacologically active compounds, six spirohydantoin derivatives were synthetized and fully characterized by determination of the melting points, elemental analysis, FT-IR, 1H and 13C NMR spectroscopic methods. Effects of the substituents on the shift of the absorption maxima of synthetized compounds were analyzed using the linear solvatation energy relationship, while the influence of the chemical structure on the pharmacokinetically relevant properties of the investigated spirohydantoin derivatives was evaluated using the Lipinski’s rule of five, Veber, Egan and Ghose’s empirical criteria, as well as different in silico methods. In order of detailed analysis of the potential pharmacological activity of the synthesized spirohydantoins, their potential pharmacological properties were correlated with the corresponding solvent effects.Hidantoin je nearomatičan petočlani ciklični ureid koji predstavlja važan strukturni fragment
velikog broja farmakološki aktivnih jedinjenja. Derivati ovog petočlanog cikličnog ureida primenjuju
se kao antikonvulzivi (fenitoin), antibiotici (nitrofurantoin), antikancerogeni lekovi (enzalutamid) i
keratolitici (alantoin). U cilju dizajniranja novih potencijalno farmakološki aktivnih jedinjenja, u
ovom radu, sintetisano je šest derivata spirohidantoina koji su u potpunosti strukturno okarakterisani
određivanjem temperature topljenja, elementarnom analizom, FT-IR, 1H i 13C NMR spektroskopskim
metodama. Efekat supstituenata na pomeranje maksimuma apsorpcije analiziran je primenom linearne korelacije energije solvatacije, dok je uticaj hemijske strukture na farmakološka svojstva derivata spirohidantoina procenjen primenom “pravila broja pet”, Veberovog, Eganovog i Gozovog
kriterijuma, kao i primenom različitih in silico metoda. U cilju opsežnije analize potencijalne farmakološke aktivnosti sintetisanih spirohidantoina, korelisana su njihova potencijalna farmakološka
svojstva sa odgovarajućim efektima rastvarača