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关键词： cancer therapy   cell death pathways   intracellular mechanisms   nanomaterial characteristics   nanomedicine  

摘要： Cancer nanomedicine has evolved in recent years and is only expected to increase due to the ease with which nanomaterials (NMs) may be manipulated to the advantage of the cancer patient. The success of nanomedicine is dependent on the cell death mechanism, which in turn is dependent on the organelle initially targeted. The success of cancer nanomedicine is also dependent on other cellular mechanisms such as the induction of autophagy dysfunction, manipulation of the tumor microenvironment (TME) and secretome or induction of host immune responses. Current cancer phototherapies for example, photothermal- or photodynamic therapies as well as radio enhancement also form a major part of cancer nanomedicine. In general, cancer nanomedicine may be grouped into those NMs exhibiting inherent anti-cancer properties that is, self-therapeutic NMs (Group 1), NMs leading to localization of phototherapies or radio-enhancement (Group 2), and NMs as nanocarriers in the absence or presence of external radiation (Group 3). The recent advances of these three groups, together with their advantages and disadvantages as well as their cellular mechanisms and ultimate outcomes are summarized in this review. By exploiting these different intracellular mechanisms involved in initiating cell death pathways, it is possible to synthesize NMs that may have the desirable characteristics to maximize their efficacy in cancer therapy. Therefore, a summary of these important physicochemical characteristics is also presented that need to be considered for optimal cancer cell targeting and initiation of mechanisms that will lead to cancerous cell death. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine

关键词： collision processes   filamentary dielectric barrier discharge   nitrogen fixation   NOx synthesis   plasma diagnostics   plasma–   liquid interactions  

摘要： In this study, an atmospheric-pressure filamentary dielectric barrier discharge plasma is produced over a deionized (DI) water surface to study the physicochemical mechanisms of plasma-liquid surface interactions for NOx synthesis. The gas-phase plasma diagnostics are performed using optical emission spectroscopy, Fourier-transform infrared spectroscopy, and by recording voltage-current curves, and liquid-phase species are analyzed using ion chromatography and UV-visible spectrophotometer. The investigations indicate that the reaction pathways for reactive oxygen and nitrogen species (H2O2, NO 2 -, N O 3 -) formation in DI water depend on different experimental conditions. It is observed that the conversion of nitrites into nitrates is significantly influenced by reactive oxygen species. The energy yield for the total amount of NOx synthesized ranges from 1.3 x 10(-4) to 3.4 x 10(-3) mol/MJ.

关键词： Enhanced oil recovery   Graphene   Physicochemical interaction   Viscosity   Diffusion coefficient   Molecular dynamic simulation  

摘要： Enhanced oil recovery (EOR) is the recovery of oil trapped in the reservoir after primary and secondary recovery processes through novel techniques. Viscosity is primarily a major cause of the high proportion of hydrocarbon fluid entrapped. Recently, emergence of nanotechnology has gained attention in oil industry. The major factor hindering the efficiency of nanoparticles is poor transport inside the reservoir due to high adsorption energy to grains surfaces, leading to their retention. Some studies have reported the effectiveness of nanoparticles on oil viscosity. However, report on the use of pristine graphene has been missing along with requisite transportation behaviour on sandstone surface. This work investigates the applicability of graphene in EOR. The effects of graphene concentrations (0.01, 0.05 & 0.1 wt%) on flowability of oil (50 cP and 0.85 cP), and its adsorption energy are reported. Experimentally, viscosity of the more viscous crude oil was reduced by 43-65%. Using molecular simulation, diffusion coefficient estimation indicate improvement in diffusivity of light decane by 112%. Furthermore, the adsorption energy of graphene is surprisingly found to be low (-9.11 kcal/mol). This study concluded that graphene is applicable, the oil sample is Newtonian and viscosity well reduced.

关键词： Biogenic hydroxyapatite   Calcite formation mechanism   In-vitro behavior   Carbonate substitutions   Thermal treatment  

摘要： This study compares and analyzes the biogenic hydroxyapatite (BHAp) powders obtained from bovine and porcine bones using two methodologies to determine the influence of the obtention process on BHAp properties. Despite the differences between the processing methods, the results obtained suggest that the thermal-treatment has a meaningful influence on physicochemical properties. Since the thermal-treatments performed (1100 degrees C for 2 h and 800 degrees C for 24 h for A-and B-methods, respectively) resulted in a hydroxyapatite crystalline phase formation as the main phase with the presence of magnesium oxide (MgO) as a secondary phase in both methods and calcium oxide (CaO) in samples obtained by A-method. The B-method samples also present higher carbonate group content (CO32-) and A-and B-type substitutions compared to the A-method. We found that the carbonate groups degrees changes can be mainly attributed to the thermal-treatment temperature. Subsequently, the BHAp samples were immersed in Hank Solution for 3, 7, 14, 21, and 28 days to study the bioactive response. We found a bone-like apatite layer formation on the surface as a function of the soaking time in all sets of samples, as was expected. However, we also found a calcite layer grown on the surface of the samples prepared by the B-method, which is associated with the carbonate ions release from these samples to the solution. Finally, a formation mechanism of calcite in samples obtained through the B-method during the exposure to Hank's solution is also proposed."

关键词： Biochar fractions   Soil carbon dynamics   High-throughput sequencing   r-strategists   K-strategists   Microbial community composition  

摘要： Biochars generally result in short-term positive priming of native soil organic carbon (SOC), but longer-term carbon (C) stabilization, and these effects can be altered by global warming. However, uncertainty remains about the mechanisms associated with these priming effects, temperature sensitivity of native SOC, and microbial responses to biochars of differing properties. To address these knowledge gaps, rice straw biochars (produced at 300 and 800 degrees C at 2% w/w application rate), and their labile (water extracted) fraction and recalcitrant (chemically oxidized) fraction (obtained from the equivalent weight of biochar) were incubated in a C4 dominated soil at 15, 25, and 35 degrees C. Our results showed that 300 degrees C biochar and its recalcitrant fraction resulted in an increased SOC mineralization due to positive priming across the incubation thermosequence. This was likely linked to an observed increase in the abundance of K-strategists (fungi and Actinobacteria). The biochar produced at 800 degrees C and its recalcitrant fraction resulted in the stabilization of native SOC (i.e., negative priming) at all temperatures, likely due to the adsorptive protection of native SOC by the large surface area. The water extractable C from both biochars generally induced SOC stabilization across the thermosequence, which could be attributed to microbial shifts to r-strategists preferentially utilizing labile C components in biochar. Both biochars increased SOC stabilization with warming from 15 to 25 degrees C, supporting the role of biochar application in soil C sequestration in cooler regions. The lower SOC stabilization by biochars with temperature increases from 25 to 35 degrees C was correlated with the biochar-induced increases in fungal growth (K-strategist) under warming. The low-temperature biochar increased the abundance of aromatic C decomposers and concomitantly lowered the Q(10) and activation energy (E-a) of native SOC. The findings from this study hi

关键词： Vesicles   Elastic compliance   Fluid/solid interface   Charge density   Adsorption  

摘要： Lipid bilayer mechanics is crucial to membrane dynamics and in design of liposomes for delivery applications. In this work, vesicles of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) (size from 50 nm to 1 mu m) and its mixtures with anionic 1,2-dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) sodium salt (DOPG) and cationic dimethyldioctadecylammonium bromide (DODAB), have been studied under shear stress at fluid/solid interface and their elastic compliance evaluated. Results show that the rate of spreading of the smaller vesicles (similar to 70 nm) is about 1.4 times slower than those of larger ones (similar to 1 mu) and that DOPC has the highest elastic compliance compared with DOPC + DOPG and DOPC + DODAB vesicles. A direct correlation between the elastic compliance and the size of the vesicles shows larger vesicles are more structurally labile during adsorption and subsequent adhesion to solid surfaces than the smaller ones. Specific role of bound water in DODAB is reflected in the lowest elastic compliance of DODAB compared to other lipids. Results show that during the process of adhesion at the fluid/air interface, the vesicles undergo contraction, thereby transmitting mechanical stresses to their microenvironment, which matches the SAXS electron density profiles that indicates larger vesicles have thicker bilayer membranes with larger volume of water compared to the smaller sized ones.

关键词： Clausenidin   Hydroxypropyl-p-cyclodextrin   Drug release   Physicochemical characterization   Cell cycle   Reactive oxygen species  

摘要： The long-term objective of the present study was to prepare, physicochemically characterize and determine the anticancer of clausenidin/hydroxypropyl-p-cyclodextrin (Clu/HPpCD) inclusion complex. We used differential scanning calorimetry, X-ray diffractometer, fourier transform infrared spectroscopy, ultraviolet?visible spectrophotometer and 13C and 1H nuclear magnetic resonance followed by in vitro anticancer assays. The orientation and intermolecular interactions of Clausenidin within cyclodextrin cavity were also ascertained by molecular docking simulation accomplished by AutoDock Vina. The guest molecule was welcomed by the hydrophobic cavity of the host molecule and sustained by hydrogen bond between host/guest molecules. The constant drug release with time, and increased solubility were found after successful complexation with HPpCD as confirmed by physicochemical characterizations. Clausenidin had greater cytotoxic effect on colon cancer HT29 cells when incorporated into HPpCD cavity than dissolved in DMSO. Also, from a comparison of cell viability between normal and cancer cells, a reduced side effect was observed. The Clu/HPpCD inclusion complex triggered reactive oxygen speciesmediated cytotoxicity in HT29 cells. The inclusion complex-treated HT29 cells showed cell cycle arrest and death by apoptosis associated with caspases activation. The presence of HPpCD seems to aid the anticancer activity of clausenidin. ? 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Chicken   High pressure   Microwave   Soluble gas stabilization   Modified atmosphere packaging   Vacuum packaging  

摘要： The study aimed at extending shelf life without compromising quality of precooked chicken breast slices by various packaging and processing technologies. The slices were packaged in modified atmosphere packaging (MAP, 40% CO2, 60% N-2), vacuum packaging (VAC, 93% vacuum), processed with high pressure (HPP, 600 MPa, 2 min), microwave volumetric heating (MVH, 1 kW, 3 x 15 s), soluble gas stabilization (SGS, 100% CO2, 18 h, 1 degrees C) followed by MAP (SGS-MAP), SGS followed by VAC (SGS-VAC), SGS followed by HPP (SGS-HPP), and SGS followed by MVH (SGS-MVH). The eight treatments were studied for their microbial and physicochemical quality during 4 degrees C storage for maximum 119 d. The results showed that MAP, the most common commercial packaging of ready-to-eat chicken, was slightly superior to VAC but much inferior to HPP, MVH, and SGS in microbial control. HPP, with/without SGS, was the most efficient method extending the shelf life of precooked chicken to more than three months. SGS improved microbial inhibition compared to non-SGS, but synergetic effects with HPP or MVH on microbial and physicochemical quality were insignificant. All treated chickens shared relatively comparable color, texture, pH and drip loss. These quality attributes changed marginally during storage while lipid oxidation increased markedly. HPP and MVH reduced lipid oxidation right after treatment and during storage. SGS suppressed the lipid oxidation but this effect did not last longer than two weeks of storage.

关键词： Biostimulation   Bioaugmentation   Phytoremediation   Vermiremediation   nZVI   Ecotoxicity  

摘要： Soils contaminated by organic and inorganic pollutants like Cr(VI) and lindane, is currently a main environmental challenge. Biological strategies, such as biostimulation, bioaugmentation, phytoremediation and vermiremediation, and nanoremediation with nanoscale zero-valent iron (nZVI) are promising approaches for polluted soil health recovery. The combination of different remediation strategies might be key to address this problem. For this reason, a greenhouse experiment was performed using soil without or with an organic amendment. Both soils were contaminated with lindane (15 mg kg(-1)) and Cr(VI) (100 or 300 mg kg(-1)). After one month of aging, the following treatments were applied: (i) combination of bioaugmentation (actinobacteria), phytoremediation (Brassica napus), and vermiremediation (Eisenia fetida), or (ii) nanoremediation with nZVI, or (iii) combination of biological treatments and nanoremediation. After 60 days, the wellness of plants and earthworms was assessed, also, soil health was evaluated through physico-chemical parameters and biological indicators. Cr(VI) was more toxic and decreased soil health, however, it was reduced to Cr(III) by the amendment and nZVI and, to a lesser extent, by the biological treatment. Lindane was more effectively degraded through bioremediation. In non-polluted soils, nZVI had strong deleterious effects on soil biota when combined with the organic matter, but this effect was reverted in soils with a high concentration of Cr(VI). Therefore, under our experimental conditions bioremediation might be the best for soils with a moderate concentration of Cr(VI) and organic matter. The application of nZVI in soils with a high content of organic matter should be avoided except for soils with very high concentrations of Cr(VI). According to our study, among the treatments tested, the combination of an organic amendment, biological treatment, and nZVI was shown to be the strategy of choice in soils with high concentrations of Cr

关键词： granular Y zeolite   decationation   dealumination   crystalline order   porous structure   acidity  

摘要： This study investigates, for the first time, the effects of steam heating of hierarchical porous-structured granular Y zeolite samples and of their subsequent treatment with aqueous nitric and citric acid solutions on the acid properties and porous structure characteristics of the samples. It was demonstrated that acid treatment of a sample not subjected to preliminary steam heating stabilization leads to its decationation, dealumination, and partial amorphization of its crystal lattice. In contrast, acid treatment of a steam-stabilized sample was found to mitigate the lattice destruction.