抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

We present an all atom potential energy function for the simulation of proteins and nucleic acids. This work is an extension of the CH united atom function recently presented by S.J. Weiner et al. J. Amer. Chem. Soc., 106, 765 (1984). The parameters of our function are based on calculations on ethane, propane, n−butane, dimethyl ether, methyl ethyl ether, tetrahydrofuran, imidazole, indole, deoxyadenosine, base paired dinucleoside phosphates, adenine, guanine, uracil, cytosine, thymine, insulin, and myoglobin. We have also used these parameters to carry out the first general vibrational analysis of all five nucleic acid bases with a molecular mechanics potential approach.

An all atom force field for simulations of proteins and nucleic acids.

We report the high capacity and rate capability of mesoporous Co3O4 nanowire (NW) arrays as anodes in Li ion batteries. At a current of 1C, the NW arrays maintain a capacity of 700 mAh/g after 20 discharge/charge cycles. When the current is increased to 50C, 50% of the capacity can be retained. With their ease of large area synthesis and superior electrochemical properties, these Co3O4 NW arrays will be interesting for practical Li ion batteries.

Mesoporous Co3O4 nanowire arrays for lithium ion batteries with high capacity and rate capability.

Structure, energetics, and dynamics of the nucleic Acid base pairs: nonempirical ab initio calculations.

Molecular structure and infrared spectra of 2-hydroxy-1,4- naphthoquinone; Experimental matrix isolation and theoretical Hartree–Fock and post Hartree–Fock study

The occurrence of photoinduced hydrogen atom transfer between two remote spots of a molecule is experimentally demonstrated. This photoprocess involves the intermediacy of an intramolecular “crane”. In an experimental case study, 7-hydroxy-4-methylquinoline-8-carbaldehyde monomers isolated in low-temperature Ar matrices are investigated. On UV (λ>295 nm) irradiation, a hydrogen atom is transferred from the O7H group to the N1 atom of the quinoline ring. Subsequent irradiation with UV (λ>360 nm) light reveals that the phototransformation is partially photoreversible. In the studied hydrogen-atom-transfer process, the exocyclic carbaldehyde group plays the role of an intramolecular crane. The possible application of systems analogous to 7-hydroxy-4-methylquinoline-8-carbaldehyde as optically driven molecular switches is discussed.

A bistable molecular switch driven by photoinduced hydrogen-atom transfer.

Infrared spectra of 5-methylcytosine in an argon matrix are reported. The results indicate that three tautomeric forms, amino-hydroxy, amino-oxo, and imino-oxo, exist simultaneously in the matrix. A UV-induced transformation of the amino-oxo form to the amino-hydroxy form was observed and utilized to separate the spectra of the tautomers. Ab initio quantum chemical calculations of the normal modes performed at the SCF/3-21G level of the theory for the three tautomers enable positive assignment of most of the observed bands

Matrix isolation and ab initio theoretical studies of the IR spectrum of 5-methylcytosine

Aggregation of nicotinamide (3-pyridine-carboxamide; NA) and picolinamide (2-pyridine-carboxamide; PA) has been investigated by matrix-isolation, supersonic jet and neat solid state infrared spectroscopy, complemented by DFT(B3LYP)/6-311++G(d,p) calculations For both compounds, the most stable dimeric structure was shown to be the centrosymmetric dimer where two monomers in their most stable forms establish two NH⋯OC hydrogen bonds The most stable structures of monomers of NA and PA were characterized in detail experimentally by matrix-isolation spectroscopy and theoretically (at both the DFT(B3LYP)/6-311++G(d,p) and MP2/6-311++G(d,p) levels) For nicotinamide, two conformers were found in the matrices, with ca 80% of the total population adopting the E form The monomers and dimers of PA and NA were also investigated by infrared spectroscopy of the studied compounds seeded in supersonic jet expansions These studies revealed that the constraints on the vibrational dynamics in the PA dimer are different from those in the NA dimer In the PA dimer, the vibrational energy flow out of the N–H stretching mode was shown to be accelerated substantially by the presence of a secondary intramolecular hydrogen bond In the glassy state of both compounds, the centrosymmetric dimer seems to be the prevalent structure In the neat crystalline state (KBr pellet), picolinamide keeps this type of dimeric structure as the constituting unit, whereas nicotinamide molecules assume a different arrangement where one of the NH⋯OC bonds is replaced by an NH⋯N(ring) bond The different crystallograpic structures which were formed by the compounds are reflected in the vibrational spectra of the solids These observations are correlated with the molecular properties of NA and PA, in particular with the greater conformational mobility of NA compared with PA This is ascribable to the absence in the NA molecule of the intramolecular NH⋯N(ring) interaction, which exists in PA

/pdf/dimer-formation-in-nicotinamide-and-picolinamide-in-the-gas-3q5jl5mh0f.pdf

Dimer formation in nicotinamide and picolinamide in the gas and condensed phases probed by infrared spectroscopy

Structural transformations were induced in conformers of glycolic acid by selective excitation with monochromatic tunable near-infrared laser light. For the compound isolated in Ar matrixes, near-IR excitation led to generation of two higher-energy conformers (GAC; AAT) differing from the most stable SSC form by 180° rotation around the C–C bond. A detailed investigation of this transformation revealed that one conformer (GAC) is produced directly from the near-IR-excited most stable conformer. The other higher-energy conformer (AAT) was effectively generated only upon excitation of the primary photoproduct (GAC) with another near-IR photon. Once these higher-energy conformers of glycolic acid were generated in an Ar matrix, they could be subsequently transformed into one another upon selective near-IR excitations. Interestingly, no repopulation of the initial most stable SSC conformer occurred upon near-IR excitation of the higher-energy forms of the compound isolated in solid Ar. A dramatically differen...

Maciej J. Nowak

Papers

Molecular structure and infrared spectra of 2-hydroxy-1,4- naphthoquinone; Experimental matrix isolation and theoretical Hartree–Fock and post Hartree–Fock study

A bistable molecular switch driven by photoinduced hydrogen-atom transfer.

Matrix isolation and ab initio theoretical studies of the IR spectrum of 5-methylcytosine

Dimer formation in nicotinamide and picolinamide in the gas and condensed phases probed by infrared spectroscopy

Near-infrared laser-induced generation of three rare conformers of glycolic acid.