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Aging could regulate many biological processes in malignancies by regulating cell senescence. Consensus cluster analysis was conducted to differentiate TCGA sarcoma cases. LASSO cox regression analysis was performed to construct an aging-related prognostic signature. We identified two categories of TCGA-sarcoma with significant difference in prognosis, immune infiltration and chemotherapy and targeted therapy. Moreover, an aging-related prognostic signature was constructed for sarcoma, which had a good performance in predicting the 3-year and 5-year overall survival of sarcoma patients. We also identified a lncRNA MALAT1/miR-508-3p/CCNA2 regulatory axis for sarcoma. This stratification could provide more evidence for estimating prognosis and immunotherapy of sarcoma. [ABSTRACT FROM AUTHOR]

A new strategy was applied to elucidate the structure of a polysaccharide from abalone gonad (AGSP). It was hydrolyzed by 0.05 M, 0.2 M, 0.5 M, and 2.0 M TFA at 100 °C for 1 h, sequentially. Every hydrolysate was ultrafiltrated (3000 Da) to collect oligo- and monosaccharides, and the final retentate was further hydrolyzed with 2.0 M TFA at 110 °C and 121 °C for 2 h, respectively. 1-Phenyl-3-methyl-5-pyrazolone (PMP) derivatization followed by HPLC–MS n analysis was applied to detect the sugar residues in these hydrolysates, which allowed proposing their location in the polysaccharide structure. The retentate after 0.5 M TFA hydrolysis was confirmed as the polysaccharide backbone, and it was further analyzed by 1D and 2D NMR spectroscopy. Thus, the structural elucidation of AGSP was accomplished, and it has a backbone of →4)-β-GlcA(1→2)-α-Man(1→ repeating unit with Fuc, Xyl and Gal in the branch. The analytical strategy demonstrated was useful to characterize the structure of polysaccharides. [ABSTRACT FROM AUTHOR]

At low temperature, the reactions of quinoline-2,3-dicarboxylic acid (2,3-H2qldc) with ZnCl2 in three different solvents gave three 0-D mononuclear compounds respectively, namely Zn(2,3-Hqldc)2(H2O)2 (1), Zn(2,3-Hqldc)2(DMSO)2 (2) and Zn(2,3-Hqldc)2(H2O)2·C6H6 (3). At high temperature, the three corresponding reactions always produced 2-D 44 topological layer [Zn(2,3-Hqldc)2]n (4). Interestingly, compound 4 may also be constructed through the temperature-driven irreversible change in solution from 1, 2 and 3. Supramolecular structure analyses reveal that through hydrogen bonding interactions, such as O–H…O/C–H…O)/C–H…π/π…π, the mononuclear units Zn(2,3-Hqldc)2(H2O)2 (1), Zn(2,3-Hqldc)2(DMSO)2 (2) and Zn(2,3-Hqldc)2(H2O)2·C6H6 (3) as well as the 2-D layer [Zn(2,3-Hqldc)2]n (4) were further assembled into 3-D 412·63 (in 1 and 4) and 3-D 424·64 (in 2 and 3) supramolecular networks, respectively. Obviously, these results show that the reaction temperature and solvent play critical roles in directing the molecular structures and supramolecular assemblies of these low-dimensional zinc(ii) compounds. [ABSTRACT FROM AUTHOR]

Bioinspired mineralization is an innovative approach to the fabrication of bone biomaterials mimicking the natural bone. Bone mineral hydroxylapatite (HAP) is preferentially oriented with c-axis parallel to collagen fibers in natural bone. However, such orientation control is not easy to achieve in artificial bone biomaterials. To overcome the lack of such orientation control, we fabricated a phage-HAP composite by genetically engineering M13 phage, a nontoxic bionanofiber, with two HAP-nucleating peptides derived from one of the noncollagenous proteins, Dentin Matrix Protein-1 (DMP1). The phage is a biological nanofiber that can be mass produced by infecting bacteria and is nontoxic to human beings. The resultant HAP-nucleating phages are able to self-assemble into bundles by forming β-structure between the peptides displayed on their side walls. The β-structure further promotes the oriented nucleation and growth of HAP crystals within the nanofibrous phage bundles with their c-axis preferentially parallel to the bundles. We proposed that the preferred orientation resulted from the stereochemical matching between the negatively charged amino acid residues within the β-structure and the positively charged calcium ions on the (001) plane of HAP crystals. The self-assembly and mineralization driven by the β-structure formation represent a new route for fabricating mineralized fibers that can serve as building blocks in forming bone repair biomaterials and mimic the basic structure of natural bones. [ABSTRACT FROM AUTHOR]

A one-pot colloidal reaction strategy was developed to synthesize asymmetric magnetic composite particles (AMCPs) with high anisotropy and magnetic content. The asymmetricity was established by having two portions of the particle composed of both polystyrene and silica, among which the latter was conjugated with magnetite nanoparticles. Phase separation was found to be critical in developing the asymmetric structure between the inorganic and polymer components during miniemulsion polymerization and the sol–gel reaction. Morphological control of the magnetic composite particles was achieved in a straightforward fashion by adjusting the processing parameters. These asymmetric nanomaterials with superparamagnetic and amphiphilic properties will have significant potential in biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract: A novel molybdenum phosphate based on [Mo6P4] inorganic subunits and [Mn(H2O)2]2+ cations, Mn[Mo6O12(OH)3(PO4)(HPO4)2(H2PO4)]2[Mn(H2O)2]2(Hen)4·13H2O (en = ethyl enediamine), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy, EPR spectrum and TGA analysis. The 3-D framework of the compound contains microporous structure with large cavities filled by mono-protonated Hen+ and water molecules. The electrochemical behavior of the compound has been also studied. [Copyright &y& Elsevier]

A synthetic strategy was developed for the preparation of porphyrins containing between one and four stereogenic centers, such that their molecular weights vary only as a result of methyl groups which give the chiral forms. The low-dimensional nanoscale aggregates of these compounds reveal the profound effects of this varying molecular chirality on their supramolecular structure and optical activity. The number of stereogenic centers influences significantly the self-assembly and chiral structure of the aggregates of porphyrin molecules described here. A scanning tunneling microscopy study of monolayers on graphite shows that the degree of structural chirality with respect to the surface increases almost linearly with the number of stereogenic centers, and only one handedness is formed in the monolayers, whereas the achiral compound forms a mixture of mirror-image domains at the surface. In solution, four hydrogen bonds induce the formation of an H-aggregate, and circular dichroism measurements and theoretical studies indicate that the compounds self-assemble into helical structures. Both the chirality and stability of the aggregates depend critically on the number of stereocenters. The chiral porphyrin derivatives gelate methylcyclohexane at concentrations dependent on the number and position of chiral groups at the periphery of the aromatic core, reflecting the different aggregation forces of the molecules in solution. Increasing the number of stereogenic centers requires more material to immobilize the solvent, in all likelihood because of the greater solubility of the porphyrins. The vibrational circular dichroism spectra of the gels show that all compounds have a chiral environment around the amide bonds, confirming the helical model proposed by calculations. The morphologies of the xerogels (studied by scanning electron microscopy and scanning force microscopy) are similar, although more fibrous features are present in the molecules with fewer stereogenic centers. Importantly, the presence of only one stereogenic center, bearing a methyl group as the desymmetrizing ligand, in a molecule of considerable molecular weight is enough to induce singlehanded chirality in both the one and two-dimensional supramolecular self-assembled structures. [ABSTRACT FROM AUTHOR]

Abstract: A novel two-dimensional heterometallic iodoplumbate, [Pb3I10Cu4(phen)2] n (phen=1,10-phenanthroline) constructed from [Pb3I10]4− iodoplumbate chains and [Cu2I4(phen)]2− entities has been hydrothermally synthesized and structurally characterized. The solid compound exhibits an intriguing semiconducting property with E g =2.62eV. The thermochromic behavior of the compound has been also studied. [Copyright &y& Elsevier]

Abstract: A new 2-D inorganic–organic hybrid constructed from mixed-valence Cu(I/II) ions and mixed ligands, (H3sip=5-sulfoisophthalic acid, bipy=4,4′-bipyridine), has been synthesized and characterized by IR, TGA, XPS, EPR and single-crystal X-ray diffraction. Two different kinds of chains in the compound constructed from [CuO4] planar squares and [CuN2O] triangulars, respectively, further interconnect together to give rise to an interesting 2-D layer framework. The compound exhibits strong yellow emission at 445nm excited by 378nm in the solid state at room temperature. [Copyright &y& Elsevier]

Using first-principles calculations, this paper systematically investigates the structural, elastic, and electronic properties of ReN4. The calculated positive eigenvalues of the elastic constant matrix show that the orthorhombic Pbca structure of ReN4 is elastically stable. The calculated band structure indicates that ReN4 is metallic. Compared with the synthesized superhard material WB4, it finds that ReN4 exhibits larger bulk and shear moduli as well as a smaller Poisson's ratio. In addition, the elastic constant c44 of ReN4 is larger than all the known 5d transition metal nitrides and borides. This combination of properties makes it an ideal candidate for a superhard material. [ABSTRACT FROM AUTHOR]

A new fluorescent molecular probe 1 was designed and constructed by combining bovine serum albumin (BSA) and N , N′ -bis(salicylidene)ethylenediamine (salen). Stimulated by Zn 2 + , tris, or EDTAH 2 Na 2 , the distance between BSA and salen was regulated, which was accompanied by an obvious change in the fluorescence intensity at 350 or 445 nm based on Förster resonance energy transfer. Moreover, based on the encoding binary digits in these inputs and outputs applying positive logic conventions, a monomolecular circuit integrating one OR, three NOT, and three YES gates, was successfully achieved. [ABSTRACT FROM AUTHOR]

Abstract: Three new hybrid mercury halides compounds with 1,4-diazabicyclo[2.2.2]octan (DABCO) ligand, namely, Hg2(μ2-I)2I3(H-DABCO) (1), {[Hg5(μ2-I)6I4(μ2-DABCO)2][Hg2I4(μ2-DABCO)]} n (2) and {[Hg2(μ2-Br)2Br2(μ2-DABCO)]·2(HgBr2)} n (3), have been synthesized. Compound 1 crystallizes in a P21 chiral space group and is a discrete dinuclear mercury(II) compound with inorganic Hg2(μ2-I)2I3 unit. Compound 2 consists of 1D neutral [Hg5(μ2-I)6I4(μ2-DABCO)2] n broad polymeric array containing uncommon inorganic decanuclear [Hg10(μ2-I)12I8] n clusters, and neutral guest Hg2(μ2-DABCO)I4 molecules. Compound 3 is composed of a neutral [Hg2(μ2-Br)2Br2(μ2-DABCO)] n polymeric chain and guest inorganic HgBr2 molecules. In all cases, the halide ions participate in the framework connectivity as bridging ligands. A variety of coordination geometries displayed by the metal sites such as linear, trigonal and tetrahedral are observed in these compounds. Of the three compounds, only compound 3 displays photoluminescence with a emission maximum at 528nm upon excitation at 468nm. In addition, these compounds are characterized by IR, elemental analysis, and thermogravimetric analysis. [ABSTRACT FROM AUTHOR]

The structure and stability of a set of (CF)60 isomers have been computed at the B3LYP/6-31G-(d) density functional theory level. The most stable isomer (6, F4@C60F56) has tube-like structure with four endo C-F bonds and fused five-membered rings at the end of the tube, while the reported most stable cage structure (2, F8@C60F52) with eight endo C-F bonds is higher in energy by 22.6 kcal/mol. This is in contrast to the isolated pentagon rule for the stability of fullerenes. The mean bond dissociation energy of 6 is larger than those of the experimental known C60F36, C60F48, and graphite fluoride. The relative energy per CF unit of 6 to graphite fluoride (CF)n is 3.7 kcal/mol, which is smaller than that of C60 fullerene per carbon to graphite (about 9-10 kcal/mol). [ABSTRACT FROM AUTHOR]

We have studied 3s(n-1and -1) Rydberg states and D0(n-1) and D1(-1) cationic states of pyrazine 1,4-diazabenzene by picosecond (2 1) resonance-enhanced multiphoton ionization (REMPI), (2 1) REMPI photoelectron imaging, He(I) ultraviolet photoelectron spectroscopy (UPS), and vacuum ultraviolet pulsed field ionization photoelectron spectroscopy (VUV−PFI-PE). The new He(I) photoelectron spectrum of pyrazine in a supersonic jet revealed a considerably finer vibrational structure than a previous photoelectron spectrum of pyrazine vapor. We performed Franck−Condon analysis on the observed photoelectron and REMPI spectra in combination with ab initio density functional theory and molecular orbital calculations to determine the equilibrium geometries in the D0and 3s(n-1) states. The equilibrium geometries were found to differ slightly between the D0and 3s states, indicating the influence of a Rydberg electron on the molecular structure. The locations of the D1−D0and 3s(-1)−3s(n-1) conical intersections were estimated. From the line width in the D1← S0spectrum, we estimated the lifetime of D1to be 12 fs for pyrazine and 15 fs for fully deuterated pyrazine. A similar lifetime was estimated for the 3s(-1) state of pyrazine by REMPI spectroscopy. The vibrational feature of D1observed in the VUV−PFI-PE measurement differed dramatically from that in the UPS spectrum, which suggests that the high-nRydberg (ZEKE) states converging to the D1vibronic state are short-lived due to electronic autoionization to the D0continuum. [ABSTRACT FROM AUTHOR]

The article presents a research which examines the structure of diarylethene dimers on highly oriented pyrolytic graphite (HOPG). After the application of a drop of solution of phenyloctane on HOPG, a well-ordered monolayer is formed. Results revealed that chiral domains are formed at the liquid/solid interface by a chiral diarylethenes. The molecules on the surface of HOPG with a locked helicity form dimers by shape complementarity.