Toward Engineering Chiral Rodlike Metal-Organic Frameworks with Rare Topologies

The establishment of novel design strategies to target chiral rodlike MOFs, elusively faced until now, is one of the most straightforward manners to widen the scope of MOFs. Here we describe our last advances on the application of the metalloligand design strategy toward the development of efficient routes to obtain chiral rodlike MOFs. To this end, we have used as precursor an enantiopure homochiral hexanuclear wheel (1), derived from the amino acid d-valine, which, after a supramolecular reorganization into a one-dimensional homochiral chain-with the same configuration as 1-led to the formation of a homochiral rodlike MOF (2) exhibiting rare etd topology

Diorganotin(IV) complexes with 2-furancarboxylic acid hydrazone derivative of benzoylacetone : synthesis, X-ray structure, antibacterial activity, DNA cleavage and molecular docking

Two new diorganotin(IV) complexes, Me2SnL and Ph2SnL, have been synthesized from the reaction of Me2SnCl2 and Ph2SnCl2 with the hydrazone H2L [H2L \ubc (Furan-2-yl) (5-hydroxy-3-methyl-5-phenyl-4,5- dihydro-1H-pyrazol-1-yl)-methanone] derived from furan-2-carbohydrazide and benzoylacetone. The new compounds have been characterized by elemental and spectroscopic analyses. The crystal structures of the monohydrate form of the ligand and of the Me2SnL derivative have been also determined by X-ray crystallography. Experimental evidences confirm the existence of the hydrazone ligand exclusively in cyclic form in both solution and solid state. On coordination to tin the hydrazone undergoes a ring opening reaction and a doubly deprotonation to act as a tridentate ligand via imine nitrogen and enolic oxygens. The tin atom in the complexes is five coordinate with geometry between square-pyramidal and trigonal-bipyramidal. The in vitro antibacterial activity of ligand and its complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The interaction between compounds with bacterial DNA was also studied by molecular docking. Our findings indicate that diphenyltin(IV) complex, by binding to DNA via minor groove to TATA sequence in genes upstream, has good activities along with the standard antibacterial drugs. Our agarose-gel electrophoresis experiments show that the ligand exert DNA cleavage, while Me2SnL and Ph2SnL did not

Sensory perception and food neophobia drive liking of functional plant-based food enriched with winemaking by-products

The use of phenol compounds obtained from unripe grapes as antioxidant sustainable food ingredients is challenging due to their specific sensory attributes, such as sourness and astringency. The aim was to evaluate sensory attributes perception and consumers' liking for beetroot purees added with phenols from unripe grapes. According to hedonic responses, consumer clusters were identified and characterized for eating behavioral attitudes. Three hundred two subjects (56% women, 18–60 years old) evaluated sweet, sour, astringency, and overall flavor intensity of and liking for four beetroot puree samples added with increasing phenols concentrations (0–1.93 g/kg). Results showed that liking decreased with increasing phenols. Interestingly, samples with highest phenols concentration, characterized by sourness, and astringency, were preferred by a segment of consumers (39% of the group). This group was characterized by a low food neophobia and tended to have high emotional eating scores compared to consumers preferring samples without or with the lowest amount of extract. These results suggest that the development of functional phenol-enriched products using winemaking by-products is challenging due to their sensory properties that negatively influence consumers' acceptance. However, with appropriate segmentation strategies it is possible to identify specific consumer targets who could appreciate these new functional foods. Practical Applications: Unripe grapes can be used as a sustainable phenol source for the development of new highly antioxidant foods. Indeed, an addition till 1.9 g/kg, besides improving both the nutritional content of the food matrices, as well as promoting the reuse of winemaking by-products, could be considered feasible from a sensory point of view. Specifically, new sustainable plant-based food product, characterized by specific sensory attributes, could be target for specific groups of consumers to foster the transition to the consumption of food products developed using value-added and sustainable ingredients

Capture of volatile iodine by newly prepared and characterized non-porous [CuI]n-based coordination polymers

Four new non-porous CuI-coordination polymers [Cu-2(mu(3)-I)(2)(mu-bpb)](n) (1a), [Cu(mu(2)-I)(mu-bpb)](n) (1b), [Cu-4(mu(2)-I)(4)(mu-bpmb)(4)](n) (2), and [CuI(mu-bdb)](n) (3) (bpb = 1,4-bis(pyrazolyl) butane; bpmb = 1,4-bis[(pyrazolyl)methyl]benzene; bdb = 1,4-bis[(3,5-dimethylpyrazolyl)methyl] benzene) have been successfully prepared and their structures fully characterized by single-crystal X-ray diffraction, FT-IR spectroscopy, PXRD and elemental analysis. Crystallographic investigation revealed that 1a, 1b, and 2 exhibit two-dimensional (2D) structures; in 1a parallel [Cu2I2](n) staircase motifs are cross-linked into two-dimensional sheets by bpb linkers with a fully extended conformation, while in the structures of 1b and 2 Cu2I2 rhomboid dimers are linked by bpb and pbmb ligands, respectively, into two-dimensional sheets with a 4(4)-sql net. Differently, compound 3 shows a one-dimensional (1D) zigzag chain structure with monomeric CuI units. All the four non-porous coordination polymers show the ability to capture volatile iodine in the gas phase. The solid-state photoluminescence properties of 1a, 1b, and 2 have also been investigated. The iodine-adsorbed samples 1a-I-2, 1b-I-2, and 2-I-2 show no fluorescence behavior

Predicting crystal growth via a unified kinetic three-dimensional partition model

Understanding and predicting crystal growth is fundamental to the control of functionality in modern materials. Despite investigations for more than one hundred years1, 2, 3, 4, 5, it is only recently that the molecular intricacies of these processes have been revealed by scanning probe microscopy6, 7, 8. To organize and understand this large amount of new information, new rules for crystal growth need to be developed and tested. However, because of the complexity and variety of different crystal systems, attempts to understand crystal growth in detail have so far relied on developing models that are usually applicable to only one system9, 10, 11. Such models cannot be used to achieve the wide scope of understanding that is required to create a unified model across crystal types and crystal structures. Here we describe a general approach to understanding and, in theory, predicting the growth of a wide range of crystal types, including the incorporation of defect structures, by simultaneous molecular-scale simulation of crystal habit and surface topology using a unified kinetic three-dimensional partition model. This entails dividing the structure into ‘natural tiles’ or Voronoi polyhedra that are metastable and, consequently, temporally persistent. As such, these units are then suitable for re-construction of the crystal via a Monte Carlo algorithm. We demonstrate our approach by predicting the crystal growth of a diverse set of crystal types, including zeolites, metal–organic frameworks, calcite, urea and L-cystine

Highly interpenetrated diamondoid nets of Zn(ii) and Cd(ii) coordination networks from mixed ligands

The syntheses, structures and thermal properties of three coordination networks [Zn(L1)(1,4-BDC)].H2O (L1 = N,N'-di(4-pyridyl)adipoamide; 1,4-H2BDC = 1,4-benzenedicarboxylic acid), 1, [Cd(L1)(1,4-BDC)].2H2O, 2, and [Zn2(L2)(1,4-BDC)2].2CH3OH (L2 = N,N'-di(4-pyridyl)dodecanamide), 3, are reported. Complexes 1 and 2 show the dia topology with the rare 8- and 9-fold interpenetrating modes, respectively, while 3 exhibits an interpenetrating 3-fold framework with the pcu Zn2(COO)2 dimer decorated topology. Complex 2 shows the maximum number of interpenetration presently known for interpenetrating diamondoid networks of coordination networks containing mixed spacer ligands

Single-cell analysis of CD4+ T-cell differentiation reveals three major cell states and progressive acceleration of proliferation

Background: Differentiation of lymphocytes is frequently accompanied by cell cycle changes, interplay that is of central importance for immunity but is still incompletely understood. Here, we interrogate and quantitatively model how proliferation is linked to differentiation in CD4+ T cells. Results: We perform ex vivo single-cell RNA-sequencing of CD4+ T cells during a mouse model of infection that elicits a type 2 immune response and infer that the differentiated, cytokine-producing cells cycle faster than early activated precursor cells. To dissect this phenomenon quantitatively, we determine expression profiles across consecutive generations of differentiated and undifferentiated cells during Th2 polarization in vitro. We predict three discrete cell states, which we verify by single-cell quantitative PCR. Based on these three states, we extract rates of death, division and differentiation with a branching state Markov model to describe the cell population dynamics. From this multi-scale modelling, we infer a significant acceleration in proliferation from the intermediate activated cell state to the mature cytokine-secreting effector state. We confirm this acceleration both by live imaging of single Th2 cells and in an ex vivo Th1 malaria model by single-cell RNA-sequencing. Conclusion: The link between cytokine secretion and proliferation rate holds both in Th1 and Th2 cells in vivo and in vitro, indicating that this is likely a general phenomenon in adaptive immunity

<i>CrystalGrower</i>: a generic computer program for Monte Carlo modelling of crystal growth.

From Europe PMC via Jisc Publications RouterHistory: ppub 2020-11-01, epub 2020-11-18Publication status: PublishedA Monte Carlo crystal growth simulation tool, CrystalGrower, is described which is able to simultaneously model both the crystal habit and nanoscopic surface topography of any crystal structure under conditions of variable supersaturation or at equilibrium. This tool has been developed in order to permit the rapid simulation of crystal surface maps generated by scanning probe microscopies in combination with overall crystal habit. As the simulation is based upon a coarse graining at the nanoscopic level features such as crystal rounding at low supersaturation or undersaturation conditions are also faithfully reproduced. CrystalGrower permits the incorporation of screw dislocations with arbitrary Burgers vectors and also the investigation of internal point defects in crystals. The effect of growth modifiers can be addressed by selective poisoning of specific growth sites. The tool is designed for those interested in understanding and controlling the outcome of crystal growth through a deeper comprehension of the key controlling experimental parameters