桥本甲状腺炎合并甲状腺癌的危险因素回归分析

目的 探讨桥本甲状腺炎（HT）合并甲状腺癌的危险因素。方法 采用回顾性病例对照研究,选取59 例HT 合并甲状腺癌患者为病例组,按照1∶2比例选取118 例HT 合并甲状腺良性结节或单纯HT 患者为对照组,对相关因素进行单因素和多因素logistic 回归分析。结果 单因素分析显示甲状腺疾病家族史、碘摄入情况、辐射接触史、甲状腺自身抗体和合并单发结节为HT 合并甲状腺癌的影响因素。经多因素分析家族史、高碘摄入、辐射接触史为HT 合并甲状腺癌的危险因素,其OR 值（95%CI）分别为2.141（1.664~2.755）、2.479（1.895~2.936）和4.596（3.693~4.997）。结论 HT 合并甲状腺癌发病机制有待于进一步研究,应针对危险因素(家族史、碘摄入情况、辐射接触史)采取措施进行早防早治。     

分段连续函数为黎曼可积的证法

利用定积分存在的充要条件及其相关性质,给出分段连续函数可积性的两种证明方法.     

Flanking Sequence Determination and Event Specific Detection of Transgenic Wheat B72-8-11b Strain

Exogenous fragment sequence and flanking sequence between exogenous fragment and recombinant chromosome of transgenic wheat B72-8-11b were successfully acquired through PCR amplification with cross-matched primers from exogenous genes. Newly acquired exogenous fragment covered the full-length sequence of transformed genes such as transformed plasmid and corresponding functional genes including marker uidA, promoter ubiquitin, lacZ, 1Dx5, and part of sequence of the wheat genome. A specific PCR detection method for transgenic wheat B72-8-11b strain was established on the basis of primers designed according to flanking sequence. The designed primers revealed specific amplification of 132 bp product of transgenic wheat B72-8-11b strain. This method is characteristics of high specificity, high reproducibility, rapid identification, and excellent accuracy for the identification of transgenic wheat B72-8-11b strain.     

Novel Dual-Grafted Copolymer Bearing Glassy Polystyrene and Crystalline Poly(Ethylene Oxide) as Side Chains

A novel grafted copolymer with two different types of side chains was synthesized via a combination of grafting-onto and grafting-from strategy. Graft copolymer with one side chains polybutadiene-graft-polystyrene (PB-g-PS) was first synthesized though the grafting-onto method. Following the subsequent grafting-from method, the second kind of side chain was introduced to the copolymer with anionic ring open polymerization of ethylene oxide, obtaining dual-grafted copolymer polybutadiene-graft-(polystyrene; poly(ethylene oxide)) (PB-g-(PS;PEO)). By this combined strategy, linear and star-shaped dual-grafted copolymer were synthesized. The resulting dual-grafted copolymers had controlled molecular weights and narrow molecular weight distributions (Mw/Mn < 1.20). The thermal behavior of this dual-grafted copolymer bearing glassy and crystalline side chains was determined by differential scanning calorimetry (DSC), revealing that poly(ethylene oxide) grafts underwent confined crystallization, and the star-shaped copolymer had more confinement effects than did the linear ones.     

When the Sum is a Minimal Sufficient Statistics for the Parameter of a Discrete Distribution with Finite Values?

We prove three theorems for iid discrete randomvariables taking two values, three values, and k (3\leq k<\infty) valuesby using the technique of indicator function. Under some specifications of the probabilities, we prove that the sum is a minimal sufficient statistics for the unknown parameter of interest of the discrete random variable taking two values, three values, and k (3\leq k<\infty) values. For the dice example, a figure shows that the specifications of the six probabilities are between 0 and 1 and sum to 1, and a fair dice is possible.     

Photoelectrochemical Detection of L‐Cysteine with a Covalently Grafted ZnTAPc‐Gr‐based Probe

L‐cysteine plays a vital role in organisms, and is an important biomarker for many pathological diseases that seriously affect human health. In the study, a photoelectrochemical (PEC) probe with zinc‐tetramine phthalocyanine covalently grafted to graphene oxide (ZnTAPc‐Gr) was developed for L‐cysteine detection. Graphene oxide (GO) with carboxyl was used to immobilize zinc‐tetramine phthalocyanine (ZnTAPc) with amidogen (a graft structure formed by an amide covalent bond), which could firmly immobilize ZnTAPc, thereby improving the photoelectrochemical performance and stability. L‐cysteine molecule, an electron acceptor, was specifically recognized by the PEC probe, exhibiting a decrease in the photocurrent signal. Under the optimal experimental conditions, the fabricated PEC probe exhibited excellent performance in L‐cysteine analysis within a linear range of 0.25–113 μM and a detection limit of 11.4 nM. The PEC probe showed high sensitivity, selectivity, and stability. The method described herein provides an effective strategy for PEC probe construction for L‐cysteine detection, and can also serve as a promising PEC platform for the analyses of other small molecules.     

Multicomponent Reductive Cross‐Coupling of an Inorganic Sulfur Dioxide Surrogate: Straightforward Construction of Diversely Functionalized Sulfones

Conventionally, sulfones are prepared by oxidation of sulfides with strong oxidants. Now, a multicomponent reductive cross‐coupling involving an inorganic salt (sodium metabisulfite) for the straightforward construction of sulfones is disclosed. Both intramolecular and intermolecular reductive cross‐couplings were comprehensively explored, and diverse sulfones were accessible from the corresponding alkyl and aryl halides. Intramolecular cyclic sulfones were systematically obtained from five‐ to twelve‐membered rings. Naturally occurring aliphatic systems, such as steroids, saccharides, and amino acids, were highly compatible with the SO₂‐insertion reductive cross‐coupling. Four clinically applied drug molecules, which include multiple heteroatoms and functional groups with active hydrogens, were successfully prepared via a late‐stage SO₂ insertion. Mechanistic studies show that alkyl radicals and sulfonyl radicals were both involved as intermediates in this transformation.     

All-Metallic Zn=Zn Double-π Bonded Octahedral Zn2M4 (M=Li,Na) Clusters with Negative Oxidation State of Zinc

Zn=Zn double bonded-especially double-π bonded-systems are scarce due to strong Coulomb repulsion caused by the Zn atom's internally crowded d electrons and very high energy of the virtual π orbitals in Zn₂ fragments. It is also rare for Zn atoms to exhibit negative oxidation states within reported Zn−Zn bonded complexes. Herein, we report Zn=Zn double-π bonded octahedral clusters Zn₂M₄ (M=Li, Na) bridged by four alkali metal ligands, in which the central Zn atom is in a negative oxidation state. Especially in D_4h−Zn₂Na₄, the natural population analysis shows that the charge of the Zn atom reaches up to −0.89 |e| (−1.11 |e| for AIM charge). Although this cooperation inevitably increases the repulsion between two Zn atoms, the introduction of the s¹-type ligands results in occupation of degenerated π orbitals and the electrons being delocalized over the whole octahedral framework as well, in turn stabilizing the octahedral molecular structure. This study demonstrates that maintaining the degeneracy of the π orbitals and introducing electrons from equatorial plane are effective means to construct double-π bonds between transitional metals.     

Valtrate from Valeriana jatamansi Jones induces apoptosis and inhibits migration of human breast cancer cells in vitro

Abstract

Valtrate is a principle compound isolated from Valeriana jatamansi Jones, a traditional Chinese folk medicine originally used to treat various nervous disorders. Here, we found that valtrate exhibited significant anti-cancer activity in vitro, especially in human breast cancer cells, while displayed relatively low cytotoxicity to normal human breast epithelial cells (MCF 10A). Valtrate induced cell cycle arrest at G2/M stage and apoptosis in MDA-MB-231 and MCF-7 cells, with reduced expression of p-Akt (Ser 473), cyclin B1 and caspase 8, and increased expression of p21, p-cdc2, cleaved-caspase 3, cleaved-caspase 7 and poly (ADP-ribose) polymerase (PARP). In addition, valtrate inhibited cell migration through down-regulation of MMP-9 and MMP-2 expression. These results demonstrate that valtrate possesses anti-breast cancer activities via cell cycle arrest, apoptosis, and inhibition of cell migration, thus supporting valtrate as a potential antitumor agent.     

Fabrication of Heterostructured Fe2TiO5–TiO2 Nanocages with Enhanced Photoelectrochemical Performance for Solar Energy Conversion

Photocatalysts with well-designed compositions and structures are desirable for achieving highly efficient solar-to-chemical energy conversion. Heterostructured semiconductor photocatalysts with advanced hollow structures possess beneficial features for promoting the activity towards photocatalytic reactions. Here we develop a facile synthetic strategy for the fabrication of Fe₂TiO₅–TiO₂ nanocages (NCs) as anode materials in photoelectrochemical (PEC) water splitting cells. A hydrothermal reaction is performed to transform MIL-125(Ti) nanodisks (NDs) to Ti–Fe–O NCs, which are further converted to Fe₂TiO₅–TiO₂ NCs through a post annealing process. Owing to the compositional and structural advantages, the heterostructured Fe₂TiO₅–TiO₂ NCs show enhanced performance for PEC water oxidation compared with TiO₂ NDs, Fe₂TiO₅ nanoparticles (NPs) and Fe₂TiO₅–TiO₂ NPs.