布朗单增量的Strassen重对数律

利用布朗单与布朗单增量的大偏差,得到了布朗单与布朗单增量的泛函重对数律.     

Hydrothermal synthesis and structure of an unprecedented layered Cd-citrate complex containing helical chains

An exploration of the cadmium-citrate system under hydrothermal conditions, has led to the isolation of a novel framework [Cd₃(H₂O)₂(C₆H₅O₇)₂]_n1. This compound features a novel 2D undulated sheet containing infinite double-stranded helical chains, which is unique among metal-citrate system identified so far. Crystal data for compound 1: Monoclinic, Space group P2₁/c, a=6.0974(12)  Å, b=15.271(3) Å, c=9.781(2) Å, β=102.74(3)°, V=888.3(3) Å³, Z=2. Other characterizations by elemental analysis, IR and TG are also described.     

Integral representation of velocity in a flow with separation simulated by a vortex sheet

The goal of this paper is to present a new integral operator that defines the velocity of a streamline flow in terms of the intensity of a free vortex sheet. This operator is important for numerical simulation of flows.     

Self-assembling diblock copolymers of poly[N-(2-hydroxypropyl)methacrylamide] and a beta-sheet peptide

The self-assembly of hybrid diblock copolymers composed of poly(HPMA) and beta-sheet peptide P11 (CH(3)CO-QQRFQWQFEQQ-NH(2)) blocks was investigated. Copolymers were synthesized via thiol-maleimide coupling reaction, by conjugation of semitelechelic poly(HPMA)-SH with maleimide-modified beta-sheet peptide. As expected, CD and CR binding studies showed that the peptide block imposed its beta-sheet structural arrangement on the structure of diblock copolymers. TEM and AFM proved that peptide and these copolymers had the ability to self-assemble into fibrils.     

A new proof of Wu’s theorem on vortex sheets

We give a new proof of Wu’s theorem on vortex sheets by using W 1,p estimate for the elliptic equation of divergence form with partially BMO cofficients and Lp boundedness of commutators of Calderón-Zygmund operators.     

四苯硼钠-季铵盐容量法快速测定造纸法再造烟叶中的钾含量

采用四苯硼钠-季铵盐容量法对造纸法再造烟叶中的钾含量进行了检测.通过精密度试验和加标回收试验对方法的重复性和回收率进行了考察,结果表明:该检测方法具有较好的重复性,相对标准偏差为1.7%(n=6),回收率达到99.14%.该法和流动分析仪(AA3)的检测结果对比表明两种方法的检测结果具有较好的一致性.该研究对造纸法再造...     

3,4,9,10-Perylenetetracarboxylic dianhydride functionalized graphene sheet as labels for ultrasensitive electrochemiluminescent detection of thrombin

A novel tracer, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) functionalized graphene sheet (GS) composite (GS–TCDA), is employed to label the secondary anti-thrombin aptamer (TBA) to construct an ultrasensitive electrochemiluminescent sandwich-type aptasensor. The GS provided large surface area for loading abundant PTCDA and TBA with good stability and biocompatibility. Because of the excellent electroconductivity of GS and the desirable optical properties of PTCDA, the as-formed Apt II bioconjugate considerably amplified the electrochmiluminescence (ECL) signal of peroxydisulfate (S₂O₈²⁻) and worked as the desirable label for Apt II. On the basis of the considerably amplified ECL signal and sandwich format, an extremely wide range from 1 fM to 1 nM with an ultralow detection limit of 0.33 fM for thrombin was obtained. Additionally, the selectivity and stability of the proposed aptasensor were also excellent. Thus, this procedure has great promise for detection of thrombin present at ultra-trace levels during early stage of diseases.     

A colloidal suspension of nanostructured poly(N-butyl benzimidazole)-graphene sheets with high oxidase yield for analytical glucose and choline detections

A colloidal suspension of nanostructured poly(N-butyl benzimidazole)-graphene sheets (PBBIns-Gs) was used to modify a gold electrode to form a three-dimensional PBBIns-Gs/Au electrode that was sensitive to hydrogen peroxide (H₂O₂) in the presence of acetic acid (AcOH). The positively charged nanostructured poly(N-butyl benzimidazole) (PBBIns) separated the graphene sheets (Gs) and kept them suspended in an aqueous solution. Additionally, graphene sheets (Gs) formed “diaphragms” that intercalated Gs, which separated PBBIns to prevent tight packing and enhanced the surface area. The PBBIns-Gs/Au electrode exhibited superior sensitivity toward H₂O₂ relative to the PBBIns-modified Au (PBBIns/Au) electrode. Furthermore, a high yield of glucose oxidase (GOD) on the PBBIns-Gs of 52.3 mg GOD per 1 mg PBBIns-Gs was obtained from the electrostatic attraction between the positively charged PBBIns-Gs and negatively charged GOD. The non-destructive immobilization of GOD on the surface of the PBBIns-Gs (GOD-PBBIns-Gs) retained 91.5% and 39.2% of bioactivity, respectively, relative to free GOD for the colloidal suspension of the GOD-PBBIns-Gs and its modified Au (GOD-PBBIns-Gs/Au) electrode. Based on advantages including a negative working potential, high sensitivity toward H₂O₂, and non-destructive immobilization, the proposed glucose biosensor based on an GOD-PBBIns-Gs/Au electrode exhibited a fast response time (5.6 s), broad detection range (10 μM to 10 mM), high sensitivity (143.5 μA mM⁻¹ cm⁻²) and selectivity, and excellent stability. Finally, a choline biosensor was developed by dipping a PBBIns-Gs/Au electrode into a choline oxidase (ChOx) solution for enzyme loading. The choline biosensor had a linear range of 0.1 μM to 0.83 mM, sensitivity of 494.9 μA mM⁻¹ cm⁻², and detection limit of 0.02 μM. The results of glucose and choline measurement indicate that the PBBIns-Gs/Au electrode provides a useful platform for the development of oxidase-based biosensors.     

Photocatalysis of TiO2 Sheets Prepared by Templating Filter Paper

Titanium dioxide sheet photocatalysts composed of interwoven microstrips were successfully synthesized using filter paper as templates. The synthesized samples were characterized by means of Fourier transform infrared spectroscopy, surface area analyzer, thermogravimetric analysis, powder X-ray diffraction, and scanning electron microscopy. The photocatalytic activities of the samples were evaluated by the degradation of methyl orange in an aqueous solution under UV-illumination. The results demonstrated that the paper-like TiO₂ sheets with the optimum proportion of anatase/rutile (10/1) had the highest photoactivity. And the presence of the filter paper fiber can improve the crystallinity, raise the anatase-rutile transformation temperature and contribute to the formation of being paper-like. A detailed formation mechanism for TiO₂ sheets is proposed.     

A Simple Method for Cell Sheet Fabrication Using Mica Surfaces Grafted with Peptide Detergent A6K

Cell sheet technology is a very important strategy for scaffold‐free tissue engineering. In order to fabricate cell sheets by a simple method, peptide detergent A₆K was grafted on mica surfaces by dropping its aqueous solution at different concentrations on the surface. As revealed by surface topographical observation and water contact angle measurement, the most hydrophobic surface was obtained using peptide solution at the concentration of 0.2 mg · mL^?1. The peptide‐grafted mica surface was used to culture mouse preosteoblast cell MC3T3‐E1. After the cells reached confluence and the peptide was biodegraded, an intact cell sheet was peeled from the mica. This simple method does not need any non‐biological reagents or complicated procedures, and may have great potential in tissue engineering based on cell sheet technology.