DataSheet1_Stable and reproducible MIP-ECL sensors for ultra-sensitive and accurate quantitative detection of Estrone.doc

Estrone (E1), as an endogenous estrogen, has a variety of physiological functions in human body and is of great significance to human health. On the other hand, it is a widely distributed and highly disturbing environmental endocrine disruptor in water. Therefore, there is an urgent need to develop a sensitive, rapid, and inexpensive method for the on-site determination of E1, which is not only for clinical diagnosis and treatment, but also for the investigation and monitoring of endogenous estrogen pollution in environmental water. In this study, Ru(bpy)32+/MWCNTs/Nafion/gold electrodes were prepared by surface electrostatic adsorption and ion exchange. A molecularly imprinted membrane (MIP) with the capability to recognize E1 molecules was prepared by sol-gel method, and the electrodes were modified with MIP to form an electrochemical luminescence sensor (MIP-ECL). This method simultaneously possesses ECL’s advantage of high sensitivity and MIP’s advantage of high selectivity. Moreover, the addition of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) improved the functionalization of the gold electrode surface and increased the binding sites of MIP. Meanwhile, the good conductivity of MWCNTs promoted electron transfer and further improved the sensitivity of the sensor. The sensor showed a wide linear interval in which the E1 concentrations can range from 0.1 μg/L to 200 μg/L, along with a high linear correlation coefficient (R2 = 0.999). The linear regression equation of the sensor was Y = 243.64x-79.989, and the detection limit (LOD) was 0.0047 μg/L. To validate our sensor, actual samples were also measured by the reference method (LC-MS/MS), and it was found that the relative deviation of quantitative results of the two different methods was less than 4.1%. This indicates that the quantitative results obtained by this sensor are accurate and can be used for rapid in situ determination of E1 in clinical samples and environmental water.</p

Stability Analysis of SIR Model with Distributed Delay on Complex Networks

<div><p>In this paper, by taking full consideration of distributed delay, demographics and contact heterogeneity of the individuals, we present a detailed analytical study of the Susceptible-Infected-Removed (SIR) epidemic model on complex population networks. The basic reproduction number of the model is dominated by the topology of the underlying network, the properties of individuals which include birth rate, death rate, removed rate and infected rate, and continuously distributed time delay. By constructing suitable Lyapunov functional and employing Kirchhoff’s matrix tree theorem, we investigate the globally asymptotical stability of the disease-free and endemic equilibrium points. Specifically, the system shows threshold behaviors: if , then the disease-free equilibrium is globally asymptotically stable, otherwise the endemic equilibrium is globally asymptotically stable. Furthermore, the obtained results show that SIR models with different types of delays have different converge time in the process of contagion: if , then the system with distributed time delay stabilizes fastest; while , the system with distributed time delay converges most slowly. The validness and effectiveness of these results are demonstrated through numerical simulations.</p></div

System, the convergence time and the final density of infected individuals when .

<p>System, the convergence time and the final density of infected individuals when .</p

Probing the Self-Assembly Mechanism of Lanthanide-Containing Sandwich-Type Silicotungstates [{Ln(H₂O)_<i>n</i>}₂{Mn₄(B-α-SiW₉O₃₄)₂­(H₂O)₂}]^6– Using Time-Resolved Mass Spectrometry and X‑ray Crystallography

The reaction of [γ-SiW₁₀O₃₆]^8– with Mn²⁺ and Ln³⁺ in an aqueous solution led to the isolation of a series of new lanthanide-containing sandwich-type polyoxometalates (POMs) [{Ln­(H₂O)_<i>n</i>}₂­{Mn₄(B-α-SiW₉O₃₄)₂­(H₂O)₂}]^6– (<b>1</b>–<b>5a</b>) (Ln = La (<b>1</b>), Nd (<b>2</b>), Gd (<b>3</b>), Dy (<b>4</b>), Er (<b>5</b>); <i>n</i> = 5, 6), which crystallize in the space groups <i>C</i>2/<i>c</i> with <i>a</i> = 33.0900(2)–32.9838(15) Å, <i>b</i> = 12.8044(10)–12.7526(6) Å, <i>c</i> = 22.8273(17)–22.6368(11) Å, <i>V</i> = 9669.2(12)–9519.7(8) ų, <i>Z</i> = 2 (<b>1</b>, <b>2</b>); <i>P</i>1̅ with <i>a</i> = 11.9502(4)–11.8447(6) Å, <i>b</i> = 13.2203(4)–13.1164(5) Å, <i>c</i> = 15.8291(5)–15.8524(7) Å, <i>V</i> = 2221.25(13)–2189.95(18) ų, <i>Z</i> = 1 (<b>3</b>, <b>4</b>, <b>5</b>), respectively. X-ray diffraction analysis reveals that they consist of two-dimensional networks based on a sandwich-type polyanion [Mn₄(B-α-SiW₉O₃₄)₂(H₂O)₂]^12– (<b>6a</b>, {Mn₄(SiW₉)₂}) and lanthanide cations (Ln³⁺), which are further connected into three-dimensional frameworks by potassium cations for <b>3</b>, <b>4</b>, and <b>5</b>. The unprecedented combination of time-resolved electrospray ionization mass spectrometry (ESI-MS) studies and X-ray crystallography allows us not only to directly observe the in-solution rearrangement of divant anion [γ-SiW₁₀O₃₆]^8– into the sandwich-type POM <b>6a</b> via an intermediate species [Mn₃(B-β-SiW₈O₃₀(OH))­(B-β-SiW₉O₃₃(OH))­(H₂O)]^12– (<b>7a</b>, {Mn₃(SiW₈)­(SiW₉)}) from ESI-MS results, but also to gain the solid-state structures of intermediate and final product isolated from reaction solutions from X-ray crystallography results, from which the self-assembly mechanism of the lanthanide-containing sandwich-type POMs <b>1</b>–<b>5a</b> was proposed

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12 décembre 19371937/12/12 (A66)-1937/12/13.Appartient à l’ensemble documentaire : PoitouCh

A Light-Responsive Reversible Molecule-Gated System Using Thymine-Modified Mesoporous Silica Nanoparticles

In this paper, a reversible light-responsive molecule-gated system based on mesoporous silica nanoparticles (MSN) functionalized with thymine derivatives is designed and demonstrated. The closing/opening protocol and release of the entrapped guest molecules is related by a photodimerization–cleavage cycle of thymine upon different irradiation. In the system, thymine derivatives with hydrophilicity and biocompatibility were grafted on the pore outlets of MSN. The irradiation with 365 nm wavelength UV light to thymine-functionalized MSN led to the formation of cyclobutane dimer in the pore outlet, subsequently resulting in blockage of pores and strongly inhibiting the diffusion of guest molecules from pores. With 240 nm wavelength UV light irradiation, the photocleavage of cyclobutane dimer opened the pore and allowed the release of the entrapped guest molecules. As a proof-of-the-concept, Ru­(bipy)₃²⁺ was selected as the guest molecule. Then the light-responsive loading and release of Ru­(bipy)₃²⁺ were investigated. The results indicated that the system had an excellent loading amount (53 μmol g^–1 MSN) and controlled release behavior (82% release after irradiation for 24 h), and the light-responsive loading and release procedure exhibited a good reversibility. Besides, the light-responsive system loaded with Ru­(bipy)₃²⁺ molecule could also be used as a light-switchable oxygen sensor

Effects of CORM-2 on platelet HS1 expression and HS1 tyrosine phosphorylation.

<p>The platelets were stimulated by LPS and co-incubated with CORM-2 for 30 min. The platelets were lysed in RIPA buffer that contained protease and phosphatase inhibitor cocktails. Platelet HS1 expression and HS1 tyrosine phosphorylation were detected by SDS- polyacrylamide gel electrophoresis and Western blotting. Representative experiments are shown in A and B. The average ratio of HS1/beta-actin and p-HS1/t-HS1 are shown in C and D. Results are described as mean ± SE of three experiments, *P<0.01 as compared to control; #P<0.05 as compared to LPS.</p

Effect of CORM-2 preconditioning on platelet HS1 expression and HS1 tyrosine phosphorylation.

<p>The platelets were pretreated with CORM-2 for 30 min followed by LPS stimulation for an additional 30 min. The platelets were lysed in RIPA supplemented with protease and phosphatase inhibitor cocktails. Platelet HS1 expression and HS1 tyrosine phosphorylation status were detected using SDS-polyacrylamide gel electrophoresis and Western immunoblotting. The representative experiments are shown in A and B. The average ratio of HS1/beta-actin and p-HS1/t-HS1 are shown in C and D. Results are described as mean ± SE of three independent experiments, *P<0.01 as compared to control; #P<0.05 as compared to LPS.</p

Correlation coefficients between the longitudinal gravitational center of catch by season (<i>G_s</i>) and the southern oscillation index (SOI).

<p>A: free-swimming catch; B: drifting-floating-object-associated catch. The lag metric for horizontal axis is season; the dash line represents the correlation 95% confidence intervals which are unadjusted for multiple comparisons.</p

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29 décembre 19141914/12/29 (A43).Appartient à l’ensemble documentaire : PoitouCh