Differential Harnack Estimates for Time-Dependent Heat Equations with Potentials

In this paper, we prove a differential Harnack inequality for positive solutions of time-dependent heat equations with potentials. We also prove a gradient estimate for the positive solution of the time-dependent heat equation.     

低分子量紫色酸性磷酸酶多克隆抗体的制备及应用

将最近从地瓜中提出来的低分子量紫色酸性磷酸酶（smPAP)基因克隆到GST融合蛋白表达载体pGEX－2T中，在大肠杆菌BL21codon plus中进行表达，用表达的融合蛋白免疫兔子产生多克隆抗体，用抗血清在昆虫细胞中表达的smPAP和地瓜提取液中分离纯化的PAP进行检测，产生了良好的交叉反应。     

Identification of one-phonon and two-phonon γ-vibrational bands in odd-ZNb nucleus

Collective bands in the neutron-rich ¹⁰³Nb nucleus have been investigated by measuring prompt γ-rays following spontaneous fission of ²⁵²Cf. Three new bands have been identified. The band based on the 716.8 keV level is proposed as a candidate for the Kπ=9/²⁺$K^{\pi }=9/2^{+}$ one-phonon γ  -vibrational band, and the band built on the 1282.1 keV level is proposed as a candidate for the Kπ=13/²⁺$K^{\pi }=13/2^{+}$ two-phonon γ-vibrational band. The two-phonon γ-vibrational band is the first such band identified in odd-Z nuclei.     

Classes on Compactifications of the Moduli Space of Curves Through Solutions to the Quantum Master Equation

In this paper we describe a construction which produces classes in compactifications of the moduli space of curves. This construction extends a construction of Kontsevich which produces classes in the open moduli space from the initial data of a cyclic A _∞-algebra. The initial data for our construction are what we call a ‘quantum A _∞-algebra’, which arises as a type of deformation of a cyclic A _∞-algebra. The deformation theory for these structures is described explicitly. We construct a family of examples of quantum A _∞-algebras which extend a family of cyclic A _∞-algebras, introduced by Kontsevich, which are known to produce all the kappa classes using his construction.      

Graph cohomology classes in the Batalin–Vilkovisky formalism

This paper gives a conceptual formulation of Kontsevich’s ‘dual construction’ producing graph cohomology classes from a differential graded Frobenius algebra with an odd scalar product. Our construction–whilst equivalent to the original one–is combinatorics-free and is based on the Batalin–Vilkovisky formalism, from which its gauge independence is immediate.     

Pressure study of monoclinic ReO2 up to 1.2 GPa using X‐ray absorption spectroscopy and X‐ray diffraction

The crystal and local atomic structure of monoclinic ReO₂ (α‐ReO₂) under hydrostatic pressure up to 1.2 GPa was investigated for the first time using both X‐ray absorption spectroscopy and high‐resolution synchrotron X‐ray powder diffraction and a home‐built B₄C anvil pressure cell developed for this purpose. Extended X‐ray absorption fine‐structure (EXAFS) data analysis at pressures from ambient up to 1.2 GPa indicates that there are two distinct Re—Re distances and a distorted ReO₆ octahedron in the α‐ReO₂ structure. X‐ray diffraction analysis at ambient pressure revealed an unambiguous solution for the crystal structure of the α‐phase, demonstrating a modulation of the Re—Re distances. The relatively small portion of the diffraction pattern accessed in the pressure‐dependent measurements does not allow for a detailed study of the crystal structure of α‐ReO₂ under pressure. Nonetheless, a shift and reduction in the (011) Bragg peak intensity between 0.4 and 1.2 GPa is observed, with correlation to a decrease in Re—Re distance modulation, as confirmed by EXAFS analysis in the same pressure range. This behavior reveals that α‐ReO₂ is a possible inner pressure gauge for future experiments up to 1.2 GPa.     

Wavelength modulation and cavity enhanced absorption spectroscopy using ～1.9?μm radiation produced by difference frequency generation with a MgO doped PPLN crystal

We have demonstrated the production of ∼1.9 μm near-infrared radiation by using difference frequency generation within a 5% MgO doped PPLN crystal by coupling ∼735 nm radiation from a tunable external cavity diode laser with relatively high powered 532 nm radiation from both Nd:YVO₃ and Nd:YAG lasers. The radiation produced is of low power, ∼15 μW, and was used in conjunction with the sensitivity enhancing techniques of wavelength modulation spectroscopy (WMS) and cavity enhanced absorption spectroscopy (CEAS). Experiments were carried out on rotationally resolved transitions in the combination bands of NH₃ and CO₂ in the 1.9 μm region. An α _min value of 3.6×10⁻⁶ cm⁻¹ Hz^−1/2 was achieved for WMS measurements on CO₂. A comparable α _min value of 2.2×10⁻⁶ cm⁻¹ Hz^−1/2 was achieved for NH₃ using CEAS. The low NIR power indicates that despite the level of MgO doping quoted for the crystal, under prolonged exposure photorefractive damage has occurred.     

Single‐Molecule Force Measurement Guides the Design of Multivalent Ligands with Picomolar Affinity

Interaction of multiple entities and receptors, or multivalency is widely applied to achieve high affinity ligands for diagnostic and therapeutic purposes. However, lack of knowledge on receptor distribution in living subjects remains a challenge for rational structure design. Herein, we develop a force measurement platform to probe the distribution and separation of the cell surface vascular endothelial growth factor receptors (VEGFR) in live cells, and use this to assess the geometry of appropriate linkers for distinct multivalent binding modes. A tetravalent lead ZD‐4, which was developed from an antitumor drug ZD6474 (Vandetanib) with combined hybrid binding effects, yielded a 2000‐fold improvement in the binding affinity to VEGFR with IC₅₀ value of 25 pm . We confirmed the improved affinity by the associated increase of tumor uptake in the VEGFR‐targeting positron emission tomography (PET) imaging using U87 tumor xenograft mouse model.     

Alkylation of inorganic oxo compounds and insights on preventing DNA damage

Metabolism of food- and tobacco-borne procarcinogens results in the exposure of DNA to toxic alkylating agents. These assaults can bring about DNA alkylation damage, mutations, and cancer. Dietary inorganic compounds such as selenium and vanadium are known to prevent cancer, possibly by reacting directly with alkylating agents, thereby preventing DNA damage. To understand potential interactions between oxo species and alkylating toxins, we reacted a series of alkylating agents with varied classes of oxo compounds (i.e., vanadates, selenate, phosphate, sulfate, acetate, nitrate, and nitrite). A new organic-soluble selenate, [(C6H5)4P]3(O3SeOCH2OSeO3)(HSeO4), was synthesized and characterized for these studies. Vanadates were found to convert ethylating agents into ethanol, whereas other anions formed esters upon alkylation. General trends show that oxo anions of the greatest charge density were the most reactive. These studies suggest that the design of new compounds for cancer prevention should incorporate reactive oxo groups with high anionic charge density.