夸克有效质量和重子磁矩

将文[7]的工作推广到m_u≠m_d的情形,用x~2—法同时拟合重子质量和重子磁矩,得到了较好的结果.     

Analysis of components of conserved “backbone sequences”among genomes of Shigella spp. strains

Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the evolution also have conserved “backbone sequences”, which reveal the marks of their origin and evolution, and these “backbone sequences”are just the basis of their elementary living abilities and common biological properties. Shigella is very closely related to E. coli in the origin and evolution, and may turn out to belong to the same genus. In this study, a microarray containing E. coli K-12 whole genome and Sf301 specific ORFs is used to investigate the genomic components of four Shigella strains. The results indicate that 16%-22% K-12 ORFs sequences are not detected in the genome of Shigella strains while the genome of Shigella contains at least 2800 conserved ORFs, which compose the common “backbone sequences”.Advanced analysis indicated that the “backbone sequences”are the essential components in maintaining the normal physiological activities of intestinal bacteria. Furthermore,only 20% Sf301-specific ORFs exist in other strains simultaneously, which demonstrate the great genome heterogeneity and the genetic diversity among the strains.     

中国竹类真菌资源和多样性(英文)

本文作者对中国竹类真菌的研究历史、多样性、生活史、地理分布、寄主选择性、组织选择性和竹类真菌的演替作了文献综述。至今中国大陆已经报道了 189种包括 75属竹类真菌 ;此外在香港还报道了 79种包括 58属的竹类真菌。这些竹类真菌大多数是子囊菌 ,其次为担子菌和半知菌。柄锈科 (Pucciniaceae)种类多样性最丰富 ,有 2 0种 ;次之为黑痣菌科 (Phyllachoraceae)有 15种 ,炭角菌科 (Xylariaceae)有 9种 ,煤炱科 (Capnodiaceae)有 8种。     

Connexins and pannexins in the skeleton: gap junctions,hemichannels and more

Regulation of bone homeostasis depends on the concerted actions of bone-forming osteoblasts and bone-resorbing osteoclasts, controlled by osteocytes, cells derived from osteoblasts surrounded by bone matrix. The control of differentiation, viability and function of bone cells relies on the presence of connexins. Connexin43 regulates the expression of genes required for osteoblast and osteoclast differentiation directly or by changing the levels of osteocytic genes, and connexin45 may oppose connexin43 actions in osteoblastic cells. Connexin37 is required for osteoclast differentiation and its deletion results in increased bone mass. Less is known on the role of connexins in cartilage, ligaments and tendons. Connexin43, connexin45, connexin32, connexin46 and connexin29 are expressed in chondrocytes, while connexin43 and connexin32 are expressed in ligaments and tendons. Similarly, although the expression of pannexin1, pannexin2 and pannexin3 has been demonstrated in bone and cartilage cells, their function in these tissues is not fully understood.     

Root tip contact with low-phosphate media reprograms plant root architecture

Plant roots are able to sense soil nutrient availability. In order to acquire heterogeneously distributed water and minerals, they optimize their root architecture. One poorly understood plant response to soil phosphate (P(i)) deficiency is a reduction in primary root growth with an increase in the number and length of lateral roots. Here we show that physical contact of the Arabidopsis thaliana primary root tip with low-P(i) medium is necessary and sufficient to arrest root growth. We further show that loss-of-function mutations in Low Phosphate Root1 (LPR1) and its close paralog LPR2 strongly reduce this inhibition. LPR1 was previously mapped as a major quantitative trait locus (QTL); the molecular origin of this QTL is explained by the differential allelic expression of LPR1 in the root cap. These results provide strong evidence for the involvement of the root cap in sensing nutrient deficiency, responding to it, or both. LPR1 and LPR2 encode multicopper oxidases (MCOs), highlighting the essential role of MCOs for plant development.     

超声-微波协同提取野马追中抗氧化活性成分

为了提高野马追提取物中抗氧化活性物质提取率,采用单因素和正交试验法,对超声-微波协同萃取野马追中抗氧化活性成分提取工艺条件进行了优化。结果表明:其最佳工艺参数为超声开启时,以体积分数20%的乙醇为溶剂,提取时间30 min,料液比(g/mL)为1∶30,微波功率为50 W。在优化条件下提取获得的野马追提取物对1,1-二苯基-2-三硝基苯肼(DPPH.)清除作用IC50值为73.9 mg/mL,其总酚含量与抗氧化活性之间存在很强的相关性(R2=0.952 3)。与其他方法相比,超声-微波协同萃取法具有节省时间、节约能量、抗氧化活性成分收率高等优点。     

High-fidelity projective read-out of a solid-state spin quantum register

Initialization and read-out of coupled quantum systems are essential ingredients for the implementation of quantum algorithms. Single-shot read-out of the state of a multi-quantum-bit (multi-qubit) register would allow direct investigation of quantum correlations (entanglement), and would give access to further key resources such as quantum error correction and deterministic quantum teleportation. Although spins in solids are attractive candidates for scalable quantum information processing, their single-shot detection has been achieved only for isolated qubits. Here we demonstrate the preparation and measurement of a multi-spin quantum register in a low-temperature solid-state system by implementing resonant optical excitation techniques originally developed in atomic physics. We achieve high-fidelity read-out of the electronic spin associated with a single nitrogen-vacancy centre in diamond, and use this read-out to project up to three nearby nuclear spin qubits onto a well-defined state. Conversely, we can distinguish the state of the nuclear spins in a single shot by mapping it onto, and subsequently measuring, the electronic spin. Finally, we show compatibility with qubit control: we demonstrate initialization, coherent manipulation and single-shot read-out in a single experiment on a two-qubit register, using techniques suitable for extension to larger registers. These results pave the way for a test of Bell's inequalities on solid-state spins and the implementation of measurement-based quantum information protocols.     

Complete genome analysis of Ketogulonigenium sp. WB0104

Ketogulonigenium sp. is a new genus defined by Urbance and Bratina[1] in 2001. It belongs to Proteo- bacteria, Alpha proteobacteria, Rhodobacterales, Rhodobacteraceae, Ketogulonigenium. Ketoguloni- genium sp. is a Gram-negative, facultatively anaerobic, e…