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The ability of strontium ion to inhibit the abnormally high bone resorption, which occurs in pathologies characterized by loss of bone substance, has stimulated a number of research on strontium substituted/doped calcium phosphates. However, no information was available up to now on strontium substitution to calcium in the structure of α-CaHPO4, monetite, in spite of the involvement of this phosphate in the composition of biomaterials for hard tissue substitution/repair and although it is isomorphous with α-SrHPO4. Herein, we investigated the substitution of strontium to calcium in the structure of α-CaHPO4, as well as the replacement of calcium for strontium in the structure of a further polymorph of SrHPO4, namely β-SrHPO4. To this purpose, monetite at increasing degree of strontium substitution for calcium was synthesized by means of direct synthesis in aqueous solution, as well as through thermal treatment of strontium-substituted brushite; whereas the synthesis of β-SrHPO4 was carried out at low temperature. The results of structural refinements, spectroscopic analysis and electron microscopy investigation indicate that the method of synthesis has a great influence on the range of strontium incorporation into α-CaHPO4, which can reach 100 at%. The morphology of the synthesized materials is also remarkably dependent on composition. The analysis of the products synthesized at low temperature shows that the upper limit of possible substitution of calcium to strontium in the structure of β-SrHPO4 is much more limited, just up to about 20 at%. Moreover, powder X-ray analysis of β-SrHPO4 states that it crystallizes with a monoclinic cell in the space group P21/c.

A copper-based metal-organic framework (MOF) was prepared using a new linker, a 5-substituted isophthalic acid bearing a propargyl carbamate group, intended to provide a terminal alkyne function protruding from the material surface to generate supported gold species for potential catalytic applications. The novel material was fully characterized by spectroscopic analyses of different kinds: FTIR, Raman, EDX, and XPS, as well as by thermal and surface area measurements. Synchrotron X-ray diffraction data analysis, in particular, revealed that this MOF, labelled [Cu(1,3-YBDC)]xH2O (x ca. 2), where Y stands for the pendant alkYne and BDC for benzene dicarboxylate, contains a complex network of 5-substituted isophthalate anions bound to Cu(II) centers, arranged in pairs within paddlewheel (or "Chinese lantern") fragments of Cu2(mu-COO)4(D)2 formulation (D being a neutral Lewis base), with a short Cu/Cu distance of 2.633(4) Angstrom. Quite unexpectedly, the apical atom in the paddlewheel structure belongs to the carbamate carbonyl oxygen atom. Such extra coordination by the propargyl carbamate groups drastically reduces the MOF porosity, a feature that was also confirmed by BET measurements. However, the MOF functionality is retained at the external crystal surface where 2% of active terminal alkynes is located.

C⁴-substituted fluoroprolines (4R)-fluoroproline ((4R)-Flp) and (4S)-fluoroproline ((4S)-Flp) have been used in protein engineering to enhance the thermodynamic stability of peptides and proteins. The electron-withdrawing effect of fluorine can bias the pucker of the pyrrolidine ring, influence the conformational preference of the preceding peptide bond, and can accelerate the cis/trans prolyl peptide bond isomerisation by diminishing its double bond character. The role of 4,4-difluoroproline (Dfp) in the acceleration of the refolding rate of globular proteins bearing a proline (Pro) residue in the cis conformation in the native state remains elusive. Moreover, the impact of Dfp on the thermodynamic stability and bioactivity of globular proteins has been seldom described. In this study, we show that the incorporation of Dfp caused a redox state dependent and position dependent destabilisation of the thioredoxin (Trx) fold, while the catalytic activities of the modified proteins remained unchanged. The Pro to Dfp substitution at the conserved cisPro76 in the thioredoxin variant Trx1P did not elicited acceleration of the rate-limiting trans-to-cis isomerization of the Ile75-Pro76 peptide bond. Our results show that pucker preferences in the context of a tertiary structure could play a major role in protein folding, thus overtaking the rules determined for cis/trans isomerisation barriers determined in model peptides., ChemBioChem, 22 (23), ISSN:1439-4227, ISSN:1439-7633

Platinum ions and nanoparticles applications in the biomedical field include a number of pathologies. In particular, platinum ions are useful in the preparation of antitumoral drugs, whereas Pt nanoparticles (PtNPs) are known to reduce cellular oxidative stress. Herein, we developed composite materials using poly(ethylenimine) functionalized hydroxyapatite (HAPEI) as support for platinum. The presence of polyelectrolyte promotes interaction with platinum ion, which is loaded in greater amount than on pure hydroxyapatite. The dimensions of PtNPs are very small (about 1 nm), but increase up to about 20–30 nm on heat treatment. Loading Pt(II) ion on the apatitic supports provide a material with cytotoxic properties towards osteosarcoma derived cell lines (SaOS2 and MG63). On the contrary, PtNPs loaded apatitic supports display good anti-oxidant properties, in agreement with their quenching activity towards H2O2. Moreover, they promote differentiation of both primary osteoblast and osteoblast cell line, as shown by the increase of the levels of Alkaline Phosphatase and Collagen type 1, and reduce the level of reactive oxygen species with a consequent decrease of cellular oxidative stress.

Vulvovaginal candidiasis (VVC) is a most common infection caused by Candida species especially, Candida albicans. Herein, we report that phytoprotein based nano scaffolds mitigates the standard antifungal drug (fluconazole) resistant C. albicans. Copper sulfide nanoparticles (CuS NPs) and the phytolectin, jacalin functionalized copper sulfide nanoparticles (JCuS NPs) were evaluated against C. albicans cells. The minimum inhibitory concentration of JCuS NPs (0.1 µM) was tenfold lower than CuS NPs (1 µM). Kill curve assay showed that the NPs exhibit anticandidal activity in a time dependent manner. Standard antifungal drugs like Amphotericin B (AMP B) and Micafungin (MF) were evaluated individually against VVC causing Candida sp. and also combined with NPs to determine their synergistic effect. Interestingly, MF which belongs to echinocandins group of antifungals exhibhited synergistic activity and AMP B which belongs to polyenes group displayed an additive effect. Molecular level studies revealed that JCuS NPs in combination with micafungin inhibits the drug resistant efflux pump of C. albicans by down-regulating the efflux genes. The results revealed that JCuS NPs and its combination with standard drugs have a better anti-candidal effect, suggesting that the lectins has the potential to serve as a drug carrier by targeting the cell surface glycans of Candida.

Organic functionalization of graphene is successfully performed via 1,3-dipolar cycloaddition of azomethine ylide in the liquid phase. The comparison between 1-methyl-2-pyrrolidinone and N,N-dimethylformamide as dispersant solvents, and between sonication and homogenization as dispersion techniques, proves N,N-dimethylformamide and homogenization as the most effective choice. The functionalization of graphene nanosheets and reduced graphene oxide is confirmed using different techniques. Among them, energy-dispersive X-ray spectroscopy allows to map the pyrrolidine ring of the azomethine ylide on the surface of functionalized graphene, while micro-Raman spectroscopy detects new features arising from the functionalization, which are described in agreement with the power spectrum obtained from ab initio molecular dynamics simulation. Moreover, X-ray photoemission spectroscopy of functionalized graphene allows the quantitative elemental analysis and the estimation of the surface coverage, showing a higher degree of functionalization for reduced graphene oxide. This more reactive behavior originates from the localization of partial charges on its surface due to the presence of oxygen defects, as shown by the simulation of the electrostatic features. Functionalization of graphene using 1,3-dipolar cycloaddition is shown to be a significant step towards the controlled synthesis of graphene-based complex structures and devices at the nanoscale., 15 pages, 8 figures, for associated Supporting Information see http://shorturl.at/dCQ07

The study aims to analyze the relationship between English language skills and the students' learning outcomes in chemistry learning that uses English as the medium of instruction (EMI). This qualitative descriptive study was conducted on 40 high school students. Data is collected and analyzed in the form of the test result of the language skills and learning outcomes. The results for students' language skills: 75 % of students are at level A2 (primary user), 15 % are at level B1 (intermediate), 5 % are at level B2 (upper-intermediate), and 5 % are at level C1 (advance/proficient user). The students' chemistry learning results are averagely low, i.e., 70 % of students gained a score under 75 as the minimum criteria of standard learning, only 30 % of students reached the score above the KKM (Criteria of Minimum Competency). The conclusion of this research is that there is a relationship between language skills and chemistry learning outcomes. Learning chemistry in English has not given good results for students' learning outcomes. Therefore, the demands of learning in English need to be supported by good language skills to understand the learning content.

Oral malignant melanoma (OMM) is an aggressive tumour, and shows deep tissue invasion at initial presentation. The prognosis is worse than that for cutaneous melanoma (CM), and the overall 5-year survival rate is 10-25%. A study of the molecular mechanisms involved in the development of OMM is necessary to identify new prognostic markers. In this study, we evaluated the possible role of nicotinamide N-methyltransferase (NNMT) in OMM. We carried out immunohistochemical analyses to evaluate the expression of NNMT in 15 OMM and 15 CM, measuring the percentage of positive cells and the value of NNMT expression intensity. Furthermore, we explored the relationship between NNMT levels and the prognostic parameters of patients with OMM. NNMT was significantly more expressed in CM compared with OMM, whereas higher staining intensity for NNMT was observed in OMM cases (P

Biocontainment is an essential feature when deploying genetically modified organisms (GMOs) in open system applications, as variants escaping their intended operating environments could negatively impact ecosystems and human health. To avoid breaches resulting from metabolic cross-feeding, horizontal gene transfer, and/or genetic mutations, synthetic auxotrophs have been engineered to become dependent on exogenously supplied xenobiotics, such as noncanonical amino acids (ncAAs). The incorporation of these abiological building blocks into essential proteins constitutes a first step toward constructing xenobiological barriers between GMOs and their environments. To transition synthetic auxotrophs further away from familiar biology, we demonstrate how bacterial growth can be confined by transition-metal complexes that catalyze the formation of an essential ncAA through new-to-nature reactions. Specifically, using a homogeneous ruthenium complex enabled us to localize bacterial growth on solid media, while heterogeneous palladium nanoparticles could be recycled and deployed up to five consecutive times to ensure the survival of synthetic auxotrophs in liquid cultures.

Originally, the kwashiorkor is a pathology justified by the low consumption of proteins and high carbohydrates in weaned children. However, today, it can appear due to multifactorial causes, one of the hypotheses being the presence of aflatoxins in foods consumed by the child population and detected in biological fluids. The objective of this work is to scoping review the presence of aflatoxins in kwashiorkor, marasmus and marasmic-kwashiorkor from organs and biological samples in children. Results reflected that the presence of aflatoxins in kwashiorkor is greater compared to marasmic-kwashiorkor and marasmus in the organs and biological samples analyzed. The relationship of this mycotoxin with the pathology shows that it can affect both genders, even up to 12 years, in addition they are detected in eight biological samples and organs, except in the spleen, and in ten African countries and in the Philippines. The appearance of this pathology has been associated in children when after weaning they consume foods with low protein content and rich in carbohydrates, but coincidentally coincides with foods where the growth of aflatoxigenic fungi is more prevalent, and even the presence of other fungi that can generate other mycotoxins, such as ochratoxin A and fumonisin B1.

Ralstonia solanacearum is a soil-borne plant pathogen which causes wilt disease in economically important crops of the Solanaceae family in tropical and temperate regions. As biofilm formation is the major virulence factor in R. solanacearum, research inputs are necessary to identify natural biofilm inhibitors to mitigate virulence of this bacterium. Hence in the present work, the anti-biofilm potential of phytochemical compound gallic acid (GA) isolated from an agricultural byproduct (cashewnut shell) was investigated. Initially the Minimum inhibitory concentration (MIC) of crude extracts of cashewnut shell and coconut shell against R. solanacearum were investigated. The MIC of both the extracts were 400 µg/ml and their sub-MIC (200 µg/ml) inhibited biofilms in the range of 62-70% and 49-57%, respectively. As the cashewnut shell extract have higher biofilm inhibitory effect compared to coconut shell extract, we proceeded our further study by isolating the major compound GA from cashewnut shell by acid hydrolysate method. The sub-MIC of crude cashewnut shell extract inhibited 85% of young biofilms. The MIC of GA were observed at 3 mg/ml and sub-MIC (1.5 mg/ml) was found to eradicate 85% of mature biofilms which was confirmed by standard crystal violet assay and the biofilm reduction was further visualized under light microscopy and scanning electron microscopic images. Toxicity of GA was evaluated against R. solanacearum through XTT cell viability assay and found no antibacterial effect at sub-MIC. Additionally, it is confirmed with growth curve and time kill assays. Swimming and twitching motility were considered as an important virulence factors to invade plants and to block the xylem vessels. Therefore, sub-MIC of GA was found to inhibit both swimming and twitching motility of about 93% and 63% respectively. Anti-biofilm efficacy of GA was also worked well with tomato plant model where remarkable biofilm inhibition was found on treatment with GA before and after 24 h of infection with R. solanacearum. Hence GA will be an alternative, cheap source which is eco-friendly as well as novel source for the treatment of R. solanacearum biofilms and to prevent wilt disease in important crops.

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A concerted effort of synthetic chemistry and synthetic biology promises to expand biological function without the need for extensive genetic manipulation. In such scenarios, man-made catalysts perform new-to-nature transformations on molecules, which are either provided or further diversified by biocatalysts in designer microbes. Here, we highlight the potential of interfacing man-made catalysts with cellular metabolism by discussing the importance of non-enzymatic, metal-catalyzed transformations in nature, means to identify biocompatible transition-metal complexes and their successful integration with cellular metabolism. Lastly, we provide a critical analysis of future prospects and remaining challenges for the applications of biocompatible catalysts in synthetic chemistry, biotechnology, and biomedicine.

In this paper we used curcumin as a functionalizing agent of gelatin films with the aim to get antioxidant materials with modulated physico-chemical properties. To this aim, we prepared gelatin films at different contents of curcumin up to about 1.2 wt%. The as-prepared films, as well as glutaraldehyde crosslinked films, were submitted to several tests: swelling, water solubility, differential scanning calorimetry, X-ray diffraction, mechanical tests and curcumin release. The radical scavenging activity of the as-prepared films is similar to that of free curcumin, indicating remarkable antioxidant properties. All the other tested properties vary as a function of curcumin content and/or the presence of the crosslinking agent. In particular, the films exhibit sustained curcumin release in different solvents. Thanks to its biocompatibility, biodegradability and lack of antigenicity, gelatin uses span from food processing to packaging and biomaterials. It follows that the modulated properties exhibited by the functionalized materials developed in this work can be usefully employed in different application fields.

Organochlorine pesticides constitute the majority of the total environmental pollutants, and a wide range of compounds have been found to be carcinogenic to humans. Among all, growing interest has been focused on β-hexachlorocyclohexane (β-HCH), virtually the most hazardous and, at the same time, the most poorly investigated member of the hexachlorocyclohexane family. Considering the multifaceted biochemical activities of β-HCH, already established in our previous studies, the aim of this work is to assess whether β-HCH could also trigger cellular malignant transformation toward cancer development. For this purpose, experiments were performed on the human normal bronchial epithelium cell line BEAS-2B exposed to 10 µM β-HCH. The obtained results strongly support the carcinogenic potential of β-HCH, which is achieved through both non-genotoxic (activation of oncogenic signaling pathways and proliferative activity) and indirect genotoxic (ROS production and DNA damage) mechanisms that significantly affect cellular macroscopic characteristics and functions such as cell morphology, cell cycle profile, and apoptosis. Taking all these elements into account, the presented study provides important elements to further characterize β-HCH, which appears to be a full-fledged carcinogenic agent.

Interfacing biocompatible, small‐molecule catalysis with cellular metabolism promises a straightforward introduction of new function into organisms without the need for genetic manipulation. However, identifying and optimizing synthetic catalysts that perform new‐to‐nature transformations under conditions that support life is a cumbersome task. To enable the rapid discovery and fine‐tuning of biocompatible catalysts, we describe a 96‐well screening platform that couples the activity of synthetic catalysts to yield non‐canonical amino acids from appropriate precursors with the subsequent incorporation of these nonstandard building blocks into GFP (quantifiable readout). Critically, this strategy does not only provide a common readout (fluorescence) for different reaction/catalyst combinations, but also informs on the organism's fitness, as stop codon suppression relies on all steps of the central dogma of molecular biology. To showcase our approach, we have applied it to the evaluation and optimization of transition‐metal‐catalyzed deprotection reactions., A multi‐well screen that rapidly reports the catalytic activity of transition‐metal catalysts in presence of live cells is reported. The activity of a catalyst to yield a non‐canonical amino acid (ncAA) from an appropriate precursor is coupled to the incorporation of the nonstandard building block into GFP (quantifiable readout; see scheme).

Multi-functionalization of calcium phosphates to get delivery systems of therapeutic agents is gaining increasing relevance for the development of functional biomaterials aimed to solve problems related to disorders of the muscolo-skeletal system. In this regard, we functionalized Strontium substituted hydroxyapatite (SrHA) with some β-lactam integrin agonists to develop materials with enhanced properties in promoting cell adhesion and activation of intracellular signaling as well as in counteracting abnormal bone resorption. For this purpose, we selected two monocyclic β-lactams on the basis of their activities towards specific integrins on promoting cell adhesion and signalling. The amount of β-lactams loaded on SrHA could be modulated on changing the polarity of the loading solution, from 3.5-24 wt% for compound 1 and from 3.2-8.4 wt% for compound 2. Studies on the release of the β-lactams from the functionalized SrHA in aqueous medium showed an initial burst followed by a steady-release that ensures a small but constant amount of the compounds over time. The new composites were fully characterized. Co-culture of human primary mesenchymal stem cells (hMSC) and human primary osteoclast (OC) demonstrated that the presence of β-lactams on SrHA favors hMSC adhesion and viability, as well as differentiation towards osteoblastic lineage. Moreover, the β-lactams were found to enhance the inhibitory role of Strontium on osteoclast viability and differentiation.

The homocysteine pathway in the preconception period should be evaluated to highlight micronutrient deficiencies and warrants optimal multivitamin supplementation, before Assisted Reproduction, as preconception care. We conducted a retrospective study aimed at investigating the role of vitamin B complex (5-methyltetrahydrofolate, vitamin B12, vitamin B6) supplement use compared with the role of only folic acid supplement use, in relation to clinical pregnancy and live birth in infertile women undergoing homologous ART. We investigated 269 Caucasian women referred to the Centre for Assisted Reproductive Technology for homologous ART. In these women, 111 (Group A) were daily supplemented with vitamin B complex and 158 (Group B) with only folic acid. In group A the mean number of Metaphase II oocytes and the 2PN Fertilization Rate were higher in comparison to group A (p = 0.04; p = 0.05, respectively). A higher percentage of women in group A had a clinical pregnancy and live birth in comparison to group B (p = 0.01; p = 0.02, respectively). Vitamin B complex supplementation remained independently associated, after multivariable adjustment, with clinical pregnancy (OR 2.03, p = 0.008) and live birth (OR 1.83, p = 0.03). Women supplemented with 5-MTHF and vitamin B12, have a higher chance of clinical pregnancy and live birth in comparison to those supplemented with only folic acid.

In a previous work, it was shown that punicalagin, an active ingredient of pomegranate, is able to bind to PDIA3 and inhibit its disulfide reductase activity. Here we provide evidence that punicalagin can also bind to PDIA1, the main expressed form of protein disulfide isomerase (PDI). In this comparative study, the affinity and the effect of punicalagin binding on each protein were evaluated, and a computational approach was used to identify putative binding sites. Punicalagin binds to either PDIA1 or PDIA3 with a similar affinity, but the inhibition efficacy on protein reductase activity is higher for PDIA3. Additionally, punicalagin differently affects the thermal denaturation profile of both proteins. Molecular docking and molecular dynamics simulations led to propose a punicalagin binding mode on PDIA1 and PDIA3, identifying the binding sites at the redox domains a’ in two different pockets, suggesting different effects of punicalagin on proteins’ structure. This study provides insights to develop punicalagin-based ligands, to set up a rational design for PDIA3 selective inhibitors, and to dissect the molecular determinant to modulate the protein activity.

The maternal environment during the periconceptional period influences foetal growth and development, in part, via epigenetic mechanisms moderated by one-carbon metabolic pathways. During embryonic development, one-carbon metabolism is involved in brain development and neural programming. Derangements in one-carbon metabolism increase (i) the short-term risk of embryonic neural tube-related defects and (ii) long-term childhood behaviour, cognition, and autism spectrum disorders. Here we investigate the association between maternal one-carbon metabolism and foetal and neonatal brain growth and development. Database searching resulted in 26 articles eligible for inclusion. Maternal vitamin B6, vitamin B12, homocysteine, and choline were not associated with foetal and/or neonatal head growth. First-trimester maternal plasma folate within the normal range (>17 nmol/L) associated with increased foetal head size and head growth, and high erythrocyte folate (1538–1813 nmol/L) with increased cerebellar growth, whereas folate deficiency (

Out-of-plane Ga2Se3 nanowires are grown by molecular beam epitaxy via Au-assisted heterovalent exchange reaction on GaAs substrates in the absence of Ga deposition. It is shown that at a suitable temperature around 560 °C the Au decorated GaAs substrate releases Ga atoms, which react with the incoming Se and feed the nanowire growth. The nanowire composition, crystal structure, and morphology are characterized by Raman spectroscopy and electron microscopy. The growth mechanism is investigated by X-ray photoelectron spectroscopy. We explore the growth parameter window and find an interesting effect of shortening of the nanowires after a certain maximum length. The nanowire growth is described within a diffusion transport model, which explains the nonmonotonic behavior of the nanowire length versus the growth parameters. Nanowire shortening is explained by the blocking of Ga supply from the GaAs substrate by thick, in-plane worm-like Ga2Se3 structures, which grow concomitantly with the nanowires, followed by backward diffusion of Ga atoms from the nanowires down to the substrate surface.

Aims: Progressive chronic kidney disease represents a dreadful complication of type 2 diabetes mellitus (T2DM). We tested the pattern of use and the renal effects of old glucose-lowering drugs in T2DM patients cared for by Italian general practitioners (GPs). Methods: Data of 2606 T2DM patients were extracted from the databases of GPs, who do not have access to the most recent glucose-lowering drugs in Italy. The rate of kidney function decline was calculated by CKD-EPIcr, based on two consecutive creatinine values. Results: Metformin was used in 55% of cases, either alone or with sulfonylureas/repaglinide, across the whole spectrum of CKD (from 66% in stage G1 to only 8% in G4). Sulfonylurea use peaked at 21–22% in stage G2–G3a, whereas repaglinide use significantly increased from 8% in G1 to 22% in G4. The median rate of CKD decline was − 1.64mL/min/1.73m2 per year; it was higher in G1 (− 3.22 per year) and progressively lower with CKD severity. 826 cases (31.7%) were classified as fast progressors (eGFR decline more negative than − 5mL/min/1.73m2 per year). The risk of fast progressing CKD was associated with increasing BMI, albuminuria, and sulfonylurea use, alone (OR, 1.47; 95% confidence interval, 1.16–1.85), or in association with metformin (OR, 1.40; 95% CI 1.04–1.88). No associations were demonstrated for metformin, cardiovascular and lipid lowering drug use. Conclusion: In the setting of Italian family practice, sulfonylurea use is associated with progressive CKD in patients with T2DM. Metformin, at doses progressively reduced according to CKD stages, as recommended by guidelines, is not associated with fast progression.

The precise spatial localization of proteins in situ by super-resolution microscopy (SRM) demands their targeted labeling. Positioning reporter molecules as close as possible to the target remains a challenge in primary cells or tissues from patients that cannot be easily genetically modified. Indirect immunolabeling introduces relatively large linkage errors, whereas site-specific and stoichiometric labeling of primary antibodies relies on elaborate chemistries. In this study, we developed a simple two-step protocol to site-specifically attach reporters such as fluorophores or DNA handles to several immunoglobulin G (IgG) antibodies from different animal species and benchmarked the performance of these conjugates for 3D STORM (stochastic optical reconstruction microscopy) and DNA-PAINT (point accumulation in nanoscale topography). Glutamine labeling was restricted to two sites per IgG and saturable by exploiting microbial transglutaminase after removal of N-linked glycans. Precision measurements of 3D microtubule labeling shell dimensions in cell lines and human platelets showed that linkage errors from primary and secondary antibodies did not add up. Monte Carlo simulations of a geometric microtubule-IgG model were in quantitative agreement with STORM results. The simulations revealed that the flexible hinge between Fab and Fc segments effectively randomized the direction of the secondary antibody, while the restricted binding orientation of the primary antibody’s Fab fragment accounted for most of the systematic offset between the reporter and α-tubulin. DNA-PAINT surprisingly yielded larger linkage errors than STORM, indicating unphysiological conformations of DNA-labeled IgGs. In summary, our cost-effective protocol for generating well-characterized primary IgG conjugates offers an easy route to precise SRM measurements in arbitrary fixed samples. ISSN:1936-0851 ISSN:1936-086X

Decarbonising highly energy-intensive industrial processes is imperative if nations are to comply with anthropogenic greenhouse gas emissions targets by 2050. This is a significant challenge for high-temperature industrial processes, such as hydrocarbon cracking, and there have been limited developments thus far. The novel concept presented in this study aims to replace the radiant section of a hydrocarbon cracking plant with a novel turbo-reactor. This is one of the first major and potentially successful attempts at decarbonising the petrochemical industry. Rather than using heat from the combustion of natural gas, the novel turbo-reactor can be driven by an electric motor powered by renewable electricity. Switching the fundamental energy transfer mechanism from surface heat exchange to mechanical energy transfer significantly increases the exergy efficiency of the process. Theoretical analysis and numerical simulations show that the ultra-high aerodynamic loading rotor is able to impart substantial mechanical energy into the feedstock without excess temperature difference and temperature magnitude. A complex shockwave system then transforms the kinetic energy into internal energy over an extremely short distance. The version of the turbo-reactor developed and presented in this study uses a single rotor row, in which a multi-stage configuration is achieved regeneratively by guiding the flow through a toroidal-shaped vaneless space. This configuration leads to a reduction in reactor volume by more than two orders of magnitude compared with a conventional furnace. A significantly lower wall surface temperature, supersonic gas velocities and a shorter primary gas path enable a controlled reduction in the residence time for chemical reactions, which optimises the yield. For the same reasons, the conditions for coke deposition on the turbo-reactor surfaces are unfavourable, leading to an increase in plant availability. This study demonstrates that the mechanical work input into the feedstock can be dissipated through an intense turbulent mixing process which maintains an ideal and controlled pressure level for cracking. Numerical calculations show that the turbulence intensity increases by nearly an order of magnitude relative to that in a industrial radiant reaction tube, which can be favourable for accelerating the chemical kinetics.

Thioredoxin (Trx) is a conserved, cytosolic reductase in all known organisms. The enzyme receives two electrons from NADPH via thioredoxin reductase (TrxR) and passes them on to multiple cellular reductases via disulfide exchange. Despite the ubiquity of thioredoxins in all taxa, little is known about the functions of resurrected ancestral thioredoxins in the context of a modern mesophilic organism. Here, we report on functional in vitro and in vivo analyses of seven resurrected Precambrian thioredoxins, dating back 1–4 billion years, in the Escherichia coli cytoplasm. Using synthetic gene constructs for recombinant expression of the ancestral enzymes, along with thermodynamic and kinetic assays, we show that all ancestral thioredoxins, as today's thioredoxins, exhibit strongly reducing redox potentials, suggesting that thioredoxins served as catalysts of cellular reduction reactions from the beginning of evolution, even before the oxygen catastrophe. A detailed, quantitative characterization of their interactions with the electron donor TrxR from Escherichia coli and the electron acceptor methionine sulfoxide reductase, also from E. coli, strongly hinted that thioredoxins and thioredoxin reductases co-evolved and that the promiscuity of thioredoxins toward downstream electron acceptors was maintained during evolution. In summary, our findings suggest that thioredoxins evolved high specificity for their sole electron donor TrxR while maintaining promiscuity to their multiple electron acceptors., Journal of Biological Chemistry, 294 (38), ISSN:0021-9258, ISSN:1083-351X

All naturally produced terpenes are derived from two universal C5 diphosphate precursors, dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate (IPP). Various prenyl transferases use DMAPP ...

Linalool is the active constituent of essential oils of several plant species like coriander, rosewood and cinnamon, which is known to have strong antibacterial activity. However, its application in food systems is limited because of low water solubility, high volatility and low stability. The present study was undertaken to overcome such problems by encapsulating the linalool into nanoemulsions using Tween 80 and water using ultrasonic assisted emulsification. The stable nanoemulsions with a mean droplet diameter of 10.9 ± 0.1 nm was obtained at a 1:3 (v/v) ratio of linalool and Tween 80. The antibacterial and antibiofilm activities of the stable nanoemulsions were further investigated. The linalool nanoemulsions showed twofold enhanced antibacterial activity against Salmonella Typhimurium through their increased ability to disrupt cell membrane integrity. Moreover, compared to the pure linalool, the linalool nanoemulsions showed an 11.5% higher antibiofilm activity. Nanoemulsions also effectively reduced the S. Typhimurium biofilm on the surface of cut pineapple. Sensory analysis showed acceptance of fresh cut pineapple with linalool nanoemulsions treatment. Therefore, results of the present study indicated the potential use of linalool nanoemulsions as a natural antibacterial and antibiofilm agent against S. Typhimurium, which could find applications in the food industry.