Research on Necessary and Sufficient Condition for Hamilton Graph

AbstractAn important concept, “closed domain” is proposed in this paper. In the same time, necessary and sufficient lemma for closed domain, R, is proved on which necessary and sufficient theorem for judging whether a general graph G is a Hamilton graph is proposed and proved. All instances in this paper are judged by comparatively using the theorem proposed herein and the original necessary condition theorem and sufficient condition theorem to prove the correctness of the method proposed in this paper

Bis(1,10-phenanthroline-κ2 N,N′)(sulfato-κ2 O,O′)nickel(II) propane-1,3-diol solvate

In the structure of the title compound, [Ni(SO4)(C12H8N2)2]·C3H8O2, the NiII ion (site symmetry 2) is six-coordinated in a distorted octa­hedral manner by four N atoms from two chelating 1,10-phenanthroline (phen) ligands and two O atoms from a bidentate sulfate ligand (2 symmetry). The dihedral angle between the two chelating NCCN groups is 80.9 (1)°. The central C atom of the propane-1,3-diol solvent mol­ecule is likewise located on a twofold rotation axis. In the crystal structure, the [Ni(SO4)(C12H8N2)2] and C3H8O2 entities are connected through inter­molecular O—H⋯O hydrogen bonding

The epitope of the VP1 protein of porcine parvovirus

Porcine parvovirus (PPV) is the major causative agent in a syndrome of reproductive failure in swine. Much has been learned about the structure and function of PPV in recent years, but nothing is known about the epitopes of the structural protein VP1, which is an important antigen of PPV. In this study, the monoclonal antibody C4 against VP1 of PPV was prepared and was used to biopan a 12-mer phage peptide library three times. The selected phage clones were identified by ELISA and then sequencing. The amino acid sequences detected by phage display were analyzed, and a mimic immuno-dominant epitope was identified. The epitope of VP1 is located in the N-terminal and contains the role amino acid sequence R-K-R. Immunization of mice indicated that the phage-displayed peptide induces antibodies against PPV. This study shows that peptide mimotopes have potential as alternatives to the complex antigens currently used for diagnosis of PPV infection or for development of vaccines

In vitro evaluation of a novel pH neutral calcium phosphosilicate bioactive glass that does not require preconditioning prior to use

It is well known that bioactive glasses can cause a significant increase in pH due to the rapid release of calcium and/or sodium ions. Consequently, preconditioning of the glass is usually required prior to surgery to negate the effect of this sudden release of ions. However, preconditioning for several days is far from ideal and also preconditioning is not practical for novel organic/inorganic sol-gel hybrids currently being developed since the organic phase will start to hydrolyze and dissolve. This study describes a bioactive glass that dissolves without causing a significant change in pH from physiologically optimal values and requires no preconditioning prior to use. The bioactivity of the pH neutral glass, hydroxyapatite formation, and cellular responses, are measured and compared directly with results from archetypal 45S5 and S70C30 bioactive glasses. A hydroxyapatite layer was found to rapidly form (within 1 day) on the surface of the pH neutral glass upon reacting with simulated body fluid. In addition, improved cell compatibility was observed compared with 45S5 and S70C30 glasses. Therefore, this pH neutral glass has significant potential for bone repair applications

A one-dimensional cadmium(II) complex supported by a sulfur–nitro­gen mixed-donor ligand

In the title compound, catena-poly[cadmium(II)-bis­(μ-5-am­ino-1,3,4-thia­diazole-2-thiol­ato)-κ2 N 3:S 2;κ2 S 2:N 3], [Cd(C2H2N3S2)2]n, the CdII ion is coordinated by two N atoms of the 1,3,4-thia­diazole rings from two ligands and two S atoms of sulfhydryl from two other ligands in a slightly distorted tetra­hedral geometry. The ligands bridge CdII ions, forming one-dimensional chains along [001], which are connected by N—H⋯N and N—H⋯S hydrogen bonds into a three-dimensional network

Ancient mitochondrial genomes reveal extensive genetic influence of the steppe pastoralists in Western Xinjiang

The population prehistory of Xinjiang has been a hot topic among geneticists, linguists, and archaeologists. Current ancient DNA studies in Xinjiang exclusively suggest an admixture model for the populations in Xinjiang since the early Bronze Age. However, almost all of these studies focused on the northern and eastern parts of Xinjiang; the prehistoric demographic processes that occurred in western Xinjiang have been seldomly reported. By analyzing complete mitochondrial sequences from the Xiabandi (XBD) cemetery (3,500–3,300 BP), the up-to-date earliest cemetery excavated in western Xinjiang, we show that all the XBD mitochondrial sequences fall within two different West Eurasian mitochondrial DNA (mtDNA) pools, indicating that the migrants into western Xinjiang from west Eurasians were a consequence of the early expansion of the middle and late Bronze Age steppe pastoralists (Steppe_MLBA), admixed with the indigenous populations from Central Asia. Our study provides genetic links for an early existence of the Indo-Iranian language in southwestern Xinjiang and suggests that the existence of Andronovo culture in western Xinjiang involved not only the dispersal of ideas but also population movement.Introduction Materials and methods - Archaeological Background, Sampling, and Sequencing - Sequence Mapping and Mitochondrial DNA Haplogroup Determination - Analysis of Xiabandi Mitochondrial DNA Genomes Results - Mitochondrial DNA Authentication and Contamination Assessment - Major Bronze Age Steppe Pastoralist Origin of the Xiabandi Mitochondrial Haplogroups - Expansion of the Bronze Age Steppe Pastoralists as a Dynamic Process to Form the Genetic Landscape of Xiabandi Individuals Discussion Conclusion

Survey and Visual Detection of Zaire ebolavirus in Clinical Samples Targeting the Nucleoprotein Gene in Sierra Leone

Ebola virus (EBOV) can lead to severe hemorrhagic fever with a high risk of death in humans and other primates. To guide treatment and prevent spread of the viral infection, a rapid and sensitive detection method is required for clinical samples. Here, we described and evaluated a reverse transcription loop-mediated isothermal amplification (RT-LAMP) method to detect Zaire ebolavirus using the nucleoprotein gene (NP) as a target sequence. Two different techniques were used, a calcein/Mn2+ complex chromogenic method and real-time turbidity monitoring. The RT-LAMP assay detected the NP target sequence with a limit of 4.56 copies/μL within 45 min under 61°C, a similar even or increase in sensitivity than that of real-time reverse transcription-polymerase chain reaction (RT-PCR). Additionally, all pseudoviral particles or non- Zaire EBOV genomes were negative for LAMP detection, indicating that the assay was highly specific for EBOV. To appraise the availability of the RT-LAMP method for use in clinical diagnosis of EBOV, of 417 blood or swab samples collected from patients with clinically suspected infections in Sierra Leone, 307 were identified for RT-LAMP-based surveillance of EBOV. Therefore, the highly specific and sensitive RT-LAMP method allows the rapid detection of EBOV, and is a suitable tool for clinical screening, diagnosis, and primary quarantine purposes