CdSe/ZnS QDs embedded polyethersulfone fluorescence composite membrane for sensitive detection of copper ions in various drinks.

The copper ion was detected rapidly by a novel sensing membrane in this paper for its damage to health and the environment. CdSe/ZnS QDs modified polyethersulfone membrane (QDs@PESM) was made by phase-inversion method using a membrane separation technique and quantum dots (QDs). When the sample passed through the membrane, the copper ions in the sample caused the membrane's fluorescence to be quenched. The fluorescence quenching value of the membrane is used to calculate the concentration of copper ions. With R2= 0.9964, Cu2+could be quantitatively detected over a wide concentration range (10-1000 µg/L). The method's LOD and LOQ were 4.27 and 14.23 µg/L, respectively. When the CdSe/ZnS QDs@PESM was used to analyze Cu2+ in various real drinks, including well water, baijiu, orange juice, beer, and milk, the recovery ranged from 79.1 to 123.9%, indicating that the CdSe/ZnS QDs@PESM can be used as a rapid, simple and reliable method to determine Cu2+ in various matrices.

Dissipation of sixteen pesticide residues from various applications of commercial formulations on strawberry and their risk assessment under greenhouse conditions.

Twelve commercial pesticide formulations containing sixteen active ingredients were applied on greenhouse strawberries at recommended and double doses. The dynamics and dietary risk analysis were investigated. A modified QuEChERS method based on the use of multi-walled carbon nanotubes (MWCNTs) as adsorbent followed by LC-MS/MS and GC-MS/MS detection was utilized for sample analysis. The half-lives of studied pesticides were 4.6-12.6 days and 3.8-15.8 days from two application doses. Dietary levels from the residue concentrations of the individual pesticides at harvest was contrasted with the acceptable daily intake (ADI) and acute reference dose (ARfD). The dietary risk assessment adopt the risk quotient (RQ) for chronic risk and risk probability (RP) for long-term dietary intake risk, respectively. The dietary risk induced by the studied pesticide residues in strawberry was acceptable for consumers except the pesticide fumigants. The pesticide residues at different pre-harvest intervals (PHIs) under greenhouse conditions were compared with the established maximum residue limits (MRLs). To reduce the residue levels and potential safety risk, a longer PHI or reduced application rates should be conducted.

METTL3-mediated m6 A methylation of TRAF5 inhibits lung adenocarcinoma cell metastasis via activation of the PI3K/AKT/NF-κB signaling pathway.

Tumor necrosis factor receptor-associated factor 5 (TRAF5) has been implicated in the pathogenesis of human malignancies. This work aimed to clarify the role of TRAF5 in lung adenocarcinoma (LUAD) progression. Herein, we uncovered that TRAF5 level was reduced in LUAD tissues. Low TRAF5 expression correlated with dismal prognosis in LUAD patients. Moreover, upregulated TRAF5 impeded cell viability, migration, and invasion, induced apoptosis in vitro, as well as impaired tumorigenicity in vivo. However, depletion of TRAF5 revealed opposing results. Moreover, TRAF5 was identified as the downstream target of methyltransferase-like 3 (METTL3)-elicited N6 -methyladenosine (m6 A) modification. METTL3 stabilized TRAF5 mRNA and positively modulated TRAF5 level. Further, TRAF5 depletion relieved the repressive phenotype caused by METTL3 addition. In addition, it was manifested that the METTL3/TRAF5 axis served as an inhibitor in LUAD through the PI3K/AKT/Nuclear Factor-Kappa B (NF-κB) signaling. Collectively, we propose that METTL3-mediated TRAF5 m6 A modification exerted as a vital tumor inhibitory function in LUAD development. The METTL3/TRAF5 axis may be a critical effector of LUAD progression.

Synthesis and Characteristics of a pH-Sensitive Sol-Gel Transition Colloid for Coal Fire Extinguishing.

Coal fires, most of which are triggered by the spontaneous combustion of coal, cause a huge waste of resources and release poisonous and harmful substances into the environment, seriously threatening the safety of industrial production. Gel flame retardant plays a core role in coal fire prevention and extinguishing. Most gel flame retardants used in coal fires possess good sealing and oxygen isolation properties, but it is difficult for them to flow deep into fire areas due to their low fluidity. Some fire extinguishing agents with good fluidity lack leak-blocking performance. In order to simultaneously improve the fluidity, leakage sealing, and oxygen isolation effects of coal fire extinguishing colloids, a novel, pH-sensitive, sol-gel transition colloid was prepared using low methoxyl pectin (LMP), calcium bentonite (Ca-Bt), sodium bentonite (Na-Bt), and water as the main components. When the initial sol-state colloid absorbed acid gas products from coal combustion, the pH value decreased and a large amount of Ca2+ in Ca-Bt precipitated, thus immediately growing calcium bridges with LMP molecules that formed a three-dimensional network structure for gelation. The optimum ratio of the new colloid was determined through X-ray diffraction, tube inversion, shock shear-temperature scanning, and genetic algorithm. By testing the fire extinguishing performance of the colloid, the findings proved that the product had good oxygen isolation performance, strong adhesion ability, high thermal stability, and strong inhibition effects on coal combustion.

Molecular wires in single-molecule junctions: charge transport and vibrational excitations.

We investigate the effect of vibrations on the electronic transport through single-molecule junctions, using the mechanically controlled break junction technique. The molecules under investigation are oligoyne chains with appropriate end groups, which represent both an ideally linear electrical wire and an ideal molecular vibrating string. Vibronic features can be detected as satellites to the electronic transitions, which are assigned to longitudinal modes of the string by comparison with density functional theory data.

Nano adamantane-conjugated BODIPY for lipase affinity and light driven antibacterial.

The increasing number of resistant bacterial strains has raised efforts in developing alternative treatment strategies. Lipase is highly expressed in most bacteria and lipase targeting dyes will be non-sacrificed materials for a sustainable method against microorganism. The combination of chemotherapy and antimicrobial photodynamic inactivation (aPDI) method will be an effective method due to enhanced antibacterial activity. Here we reported the spectroscopic features of five boron dipyrrolylmethene (BODIPY) derivatives with different functional groups for lipase affinity and antibacterial activity. Lipase affinity tests and antibacterial assays were conducted by spectroscopic methods. Adamantane-conjugated BODIPY (BDP-2) was found to be the active compound against E. coli. Next, BDP-2 was brominated, and then assembled with PEG resulting biocompatible BDP2-Br2@mPEG nanoparticles. The MTT assay indicated that BDP2-Br2@mPEG was less toxicity on BGC-823 cancer cells without irradiation. The BDP2-Br2@mPEG can inhibit the proliferation of E. coli and damage the membrane of bacterial cell under green LED light irradiation. The results proved BDP2-Br2@mPEG can be a very promising green LED light driven antibacterial material.

Wire like diplatinum, triplatinum, and tetraplatinum complexes featuring X[PtC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC[triple bond, length as m-dash]C]mPtX segments; iterative syntheses and functionalization for measurements of single molecule properties.

Reaction of (p-tol3P)2PtCl2 and Me3Sn(C[triple bond, length as m-dash]C)2SiMe3 (1 : 1/THF/reflux) gives monosubstituted trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)2SiMe3 (63%), which with wet n-Bu4N+ F- yields trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)2H (2, 96%). Hay oxidative homocoupling (O2/CuCl/TMEDA) gives all-trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2Cl (3, 68%). Reaction of 3 and Me3Sn(C[triple bond, length as m-dash]C)2SiMe3 (1 : 1/rt) affords monosubstituted all-trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2SiMe3 (46%), which is converted by a similar desilylation/homocoupling sequence to all-trans-Cl[(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4]3Pt(Pp-tol3)2Cl (7; 79%). Reaction of (p-tol3P)2PtCl2 and excess H(C[triple bond, length as m-dash]C)2SiMe3 (HNEt2/cat. CuI) gives trans-Me3Si(C[triple bond, length as m-dash]C)2Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2SiMe3 (78%), which with wet n-Bu4N+ F- affords trans-H(C[triple bond, length as m-dash]C)2Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2H (96%). Hay oxidative cross coupling with 2 (1 : 4) gives all-trans-Cl[(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4]2Pt(Pp-tol3)2Cl (10, 36%) along with homocoupling product 3 (33%). Reaction of 3 and Me3Sn(C[triple bond, length as m-dash]C)2SiMe3 (1 : 2/rt) yields all-trans-Me3Si(C[triple bond, length as m-dash]C)2(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2SiMe3 (17, 77%), which with wet n-Bu4N+ F- gives all-trans-H(C[triple bond, length as m-dash]C)2(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2H (96%). Reaction of 3 and excess Me3P gives all-trans-Cl(Me3P)2Pt(C[triple bond, length as m-dash]C)4Pt(PMe3)2Cl (4, 86%). A model reaction of trans-(p-tol)(p-tol3P)2PtCl and KSAc yields trans-(p-tol)(p-tol3P)2PtSAc (12, 75%). Similar reactions of 3, 7, 10, and 4 give all-trans-AcS[(R3P)2Pt(C[triple bond, length as m-dash]C)4]nPt(PR3)2SAc (76-91%). The crystal structures of 3, 17, and 12 are determined. The first exhibits a chlorine-chlorine distance of 17.42 Å; those in 10 and 7 are estimated as 30.3 Å and 43.1 Å.

Cubic nonlinear optical properties of platinum-terminated polyynediyl chains.

The wavelength dependence of the cubic nonlinearity of ligated platinum-terminated polyynes trans, trans-{(p-MeC6H4)3P}2(p-MeC6H4)Pt(C[triple bond]C)n Pt(p-C6H4Me){P(p-C6H4Me)3}2 (n = 3-6, 8, 10, 12) has been examined by femtosecond Z-scan studies in the wavelength range 520-1500 nm and the results rationalized by density functional theory calculations on the model complexes trans, trans-(H3P)2(C6H5)Pt(C[triple bond]C)n Pt(C6H5)(PH3)2 (n = 2-8, 10, 12). Although the final states for one- and two-photon transitions are not the same in these centrosymmetric molecules, the Z-scan studies reveal coincidences in one-photon absorption with features in the frequency dependencies of both real and imaginary parts of the cubic hyperpolarizability, as well as inflections in the frequency dependencies of the real part of gamma that correspond to resonances in the imaginary part of gamma. The theoretical studies suggest that the linear absorption spectra are dominated by X(1)A g --> n(1)B(3u) transitions, with the first state of B(3u) symmetry playing a steadily diminishing role upon oligoyne chain lengthening. The theoretical studies also predict a red-shift of two-photon absorption (TPA) profile with increasing conjugation length, and a significant enhancement on proceeding from the shortest to the longest chromophore, trends that are observed experimentally. The experimental low-energy TPA maxima for these complexes can be approximated by a simple Gaussian profile. The sp-carbon chain-length dependence of linear and nonlinear absorption maxima enable an estimate (neglecting saturation) of 660 and 1000 nm for the infinite carbon chain, carbyne.

Photophysics of diplatinum polyynediyl oligomers: chain length dependence of the triplet state in sp carbon chains.

The series of polyynes with the structure trans, trans-[Ar-Pt(P 2)-(C[triple bond]C) n -Pt(P 2)-Ar], where P = tri( p-tolyl)phosphine, Ar = p-tolyl, and n = 3, 4, 5, 6 (6, 8, 10, 12 sp carbon atoms), has been subjected to a comprehensive photophysical investigation. At low temperature ( T < 140 K) in a 2-methyltetrahydrofuran (MTHF) glass, the complexes exhibit moderately efficient phosphorescence appearing as a series of narrow (fwhm < 200 cm (-1)) vibronic bands separated by ca. 2100 cm (-1). The emission is assigned to a (3)pi,pi* triplet state that is concentrated on the sp carbon chain, and the vibronic progression arises from coupling of the excitation to the -C[triple bond]C- stretch. The 0-0 energy of the phosphorescence decreases with increasing sp carbon chain length, spanning a range of over 6000 cm (-1) across the series. Transient absorption spectroscopy carried out at ambient temperature confirms that the (3)pi,pi* triplet is produced efficiently, and it displays a strongly allowed triplet-triplet absorption. In the MTHF solvent glass ( T < 140 K), the emission lifetimes increase with emission energy. Analysis of the triplet nonradiative decay rates reveals a quantitative energy gap law correlation. The nonradiative decay rates can be calculated by using parameters recovered from a single-mode Franck-Condon fit of the emission spectra.

A synthetic breakthrough into an unanticipated stability regime: a series of isolable complexes in which C6, C8, C10, C12, C16, C20, C24, and C28 polyynediyl chains span two platinum atoms.

The reaction of trans-[PtCl(p-tol){P(p-tol)3}2] (PtCl) and H(C[triple chemical bond]C)2H (cat. CuI, HNEt2) gives PtC4H (82 %), which can be cross-coupled with excess HC[triple chemical bond]CSiEt3 (acetone, O2, CuCl/TMEDA; Hay conditions) to yield PtC6Si (77 %). The addition of nBu4N+F- in wet acetone gives PtC6H (84 %), and further addition of ClSiMe3 (F- scavenger) and excess HC[triple chemical bond]CSiEt3 (Hay conditions) yields PtC(8)Si (23 %). Similar cross-coupling reactions of PtCxH (generated in situ for x>6) and excess H(C[triple chemical bond]C)2SiEt3 give a) x=4, PtC8Si (29 %), PtC12Si (30 %), and PtC16Si (1 %); b) x=6, PtC10Si (59 %) and PtC14Si (7 %); c) x=8, PtC12Si (42 %); and d) x=10, PtC14Si (20 %). Hay homocoupling reactions of PtC4H, PtC6H, PtC8H, and PtC10H give PtC8Pt, PtC12Pt, PtC16Pt, and PtC20Pt (88-70 %), but PtC12H decomposes too rapidly. However, when PtC12Si and PtC14Si are subjected to Hay conditions, protodesilylation occurs in the presence of the oxidizing agent and PtC24Pt (36 %) and PtC28Pt (51 %) are isolated. Reactions of PtC6H and PtC10H with PtCl (CuI, HNEt2) give PtC6Pt (56 %) and PtC10Pt (84 %). The effect of the chain lengths in PtCxPt upon thermal stabilities (>200 degrees C for x< or =20), IR nu(C[triple chemical bond]C) patterns (progressively more bands), colors (yellow to orange to deep red), UV/Vis spectra (progressively red-shifted and more intense bands with epsilon>400,000 M(-1) cm(-1)), redox properties (progressively more difficult oxidations), and NMR spectra (many monotonic trends) are analyzed, including implications for the sp carbon allotrope carbyne. Whereas all other dodecaynes and tetradecaynes rapidly decompose at room temperature, PtC24Pt and PtC28Pt remain stable at >140 degrees C. Crystal structures of PtCxSi (x=6, 8, 10) and PtCxPt (x=6, 8, 10, 12) have been determined.

A synthetic breakthrough into an unanticipated stability regime: readily isolable complexes in which C16-C28 polyynediyl chains span two platinum atoms.

The oxidative cross-coupling of trans-(p-tol)(p-tol3P)2Pt(CC)2H (PtC4H) and excess H(CC)2SiEt3 (O2, cat. CuCl, TMEDA, acetone; Hay conditions) gives PtC8Si (29%), PtC12Si (30%), and PtC16Si (1%; Si = SiEt3). The less stable PtC6H is generated in situ from PtC6Si and n-Bu4N+F-; following the addition of ClSiMe3 (F- scavenger) and excess H(CC)2SiEt3, the Hay conditions afford PtC10Si (59%) and PtC14Si (7%). Analogous sequences can be conducted with PtC8Si and PtC10Si. When PtC6Si, PtC8Si, and PtC10Si are similarly reacted in the absence of H(CC)2SiEt3, homocouplings to PtC12Pt (88%), PtC16Pt (70%), and PtC20Pt (72%) occur. However, analogous reactions of PtC12Si and PtC14Si fail, presumably due to the rapid decomposition of PtC12H and PtC14H. Brønsted acidity trends suggest that (CC)n moieties should become better leaving groups with increasing chain length. Thus, when PtC12Si and PtC14Si are subjected to the Hay conditions alone, PtC24Pt (36%) and PtC28Pt (51%) are isolated, with substantial recovery of starting material from the former reaction. Presumably adventitious water and/or other nucleophiles effect desilylation (as also seen in the cross-couplings), after which homocoupling is rapid due to the simultaneous availability of an oxidizing agent. PtC24Pt and PtC28Pt are thermally stable to >/=140 degrees C, whereas all other known dodecaynes and tetradecaynes rapidly decompose at room temperature. There is every reason to believe that this series can be further extended. UV-visible spectra show progressively red-shifted and more intense bands with epsilon > 400 000 M-1 cm-1.