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.

Theoretical and matrix-isolation experimental study on 2(1H)-pyridinethione/2-pyridinethiol

Oxo−hydroxy tautomerism and phototautomerism of 2-quinolinone, 1-isoquinolinone, 3-hydroxyisoquinoline, 2-quinoxalinone, and 4-quinazolinone were studied using the matrix-isolation technique. These compounds contain a benzene ring fused with a heterocyclic ring of 2-pyridinone, 2-pyrazinone, or 4-pyrimidinone. It turned out that direct attachment of a benzene ring to a heterocycle leads to a very pronounced increase of the relative stability of oxo tautomers (in comparison with the tautomerism of the parent compounds 2-pyridinone, 2-pyrazinone, and 4-pyrimidinone). The only exception concerns 3-hydroxyisoquinoline, where fusion with a benzene ring enforces rearrangement of the double- and single-bond system in the oxo tautomer. This destabilizes substantially the oxo form with respect to the hydroxy tautomer. The ratios of population of the oxo and hydroxy tautomers observed in Ar matrixes correspond to the tautomeric equilibria of the compounds in the gas phase. These equilibria were well reproduced by t...

Systematic effect of benzo-annelation on Oxo-hydroxy tautomerism of heterocyclic compounds. Experimental matrix-isolation and theoretical study

Potential energy (PE) surfaces of the lowest excited states of the 4(3H)-pyrimidinone/4-hydroxypyrimidine system were investigated with the aid of the CC2 and CASSCF methods of the electronic struc...

A Computational Study on the Mechanism of Intramolecular Oxo−Hydroxy Phototautomerism Driven by Repulsive πσ* State

Photoisomerization processes involving five isomers of cytosine were induced by narrowband tunable UV irradiation of matrix-isolated monomers of the compound. Irradiation of an argon matrix containing cytosine monomers with UV λ = 313 nm laser light resulted in syn ↔ anti photoisomerizations between the two imino–oxo forms, whereas the substantially more populated amino–hydroxy and amino–oxo forms stayed intact. Subsequent irradiation with shorter-wavelength UV λ = 311 nm laser light led to two concomitant phototautomeric processes consuming the amino–oxo isomer: (i) an oxo → hydroxy hydrogen-atom transfer photoprocess converting the amino–oxo form into the amino–hydroxy tautomer; (ii) amino → imino hydrogen-atom transfer converting the amino–oxo form into the imino–oxo isomers. The UV-induced phototransformations, together with mutual conversions of the two amino–hydroxy conformers induced by irradiation with narrowband NIR light, allowed positive detection and identification of the five isomeric forms of monomeric cytosine. This is the first experimental observation of all five low-energy isomers of cytosine.

/pdf/five-isomers-of-monomeric-cytosine-and-their-4b3vu1blpl.pdf

Five isomers of monomeric cytosine and their interconversions induced by tunable UV laser light.

Infrared spectra of glutarimide isolated in low-temperature Ar and N2 matrixes are reported. The molecular structure, vibrational frequencies, and infrared intensities of glutarimide are calculated with ab initio Hartree−Fock and second-order Moller−Plesset perturbation (MP2) methods as well as with density functional theory (DFT) using the nonlocal gradient corrected functional (BP86). The best overall agreement between the calculated and experimental spectra has been obtained at the MP2/D95V** level. Unequivocal assignment of the experimental infrared bands is performed on the basis of the potential energy distribution (PED). A striking similarity is noted for frequencies of the corresponding CO and NH vibrations in glutarimide and in uracil, thymine, and their methyl derivatives. Furthermore, the significant flattening of the glutarimide ring, predicted by calculations, indicates its structural resemblance to pyrimidine bases. It is suggested that some glutarimide drugs are able to intercalate between ...

Maciej J. Nowak

Papers

Theoretical and matrix-isolation experimental study on 2(1H)-pyridinethione/2-pyridinethiol

Systematic effect of benzo-annelation on Oxo-hydroxy tautomerism of heterocyclic compounds. Experimental matrix-isolation and theoretical study

A Computational Study on the Mechanism of Intramolecular Oxo−Hydroxy Phototautomerism Driven by Repulsive πσ* State

Five isomers of monomeric cytosine and their interconversions induced by tunable UV laser light.

Infrared matrix isolation and theoretical studies on glutarimide