1,2;5,6-Di-O-isopropyl­idene-3-C-nitro­methyl-α-d-allofuran­ose

The mol­ecule of the title compound, C13H21NO8, consists of two methyl­enedi­oxy rings and one tetra­hydro­furan ring. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into helical chains running along the 61 screw axis. Weak inter­molecular C—H⋯O hydrogen bonds help to stabilize the crystal packing. Voids of 245 Å3 per unit cell occur

HIV-1 Tat protein alter the tight junction integrity and function of retinal pigment epithelium: an in vitro study

<p>Abstract</p> <p>Background</p> <p>How HIV-1 enter into the eyes remains obscure. We postulated that HIV-1 Tat protein can alter the expression of specific tight-junction proteins and disturb the blood retinal barrier, and contributes to HIV trafficking into the eyes. This study is to determine the effects of HIV-1 Tat proteins on the barrier function and tight-junction protein expression of retinal pigment epithelial cell (RPE).</p> <p>Methods</p> <p>A human RPE cell line (D407) cultured on microporous filter-supports was used. After treating with HIV-1 Tat protein, transepithelial electrical resistance (TER) of confluent RPE cells was measured by epithelial voltmeter. The permeability of the RPE cells to sodium fluorescein was measured. The expressions of the occludin and claudins were determined by real-time polymerase chain reaction, immunofluorescence, and Western blot analysis. Activation of ERK1/2 was detected by Western blot analysis with specific antiphospho protein antibodies. NF-κB DNA binding activity was determined by transcription factor assay. Specific pharmacologic inhibitors directed against the MAPKs were used to analyze the signaling involved in barrier destruction of RPE cells exposed to HIV-1 Tat.</p> <p>Results</p> <p>Treating cultured human retinal pigment epithelial cells with 100 nM Tat for 24 hours increased the permeability and decreased the TER of the epithelial monolayer. HIV-1 Tat also disrupted and downregulated the tight-junction proteins claudin-1, claudin-3, and claudin-4 in these cells, whereas claudin-2 was upregulated, and the expression of occludin was unaffected. HIV-1 Tat protein also induced activation of ERK1/2 and NF-κB. HIV-1 Tat protein induced barrier destruction, changes in expression of TJs, and activation of ERK1/2 and NF-κB were abrogated by inhibitor of ERK1/2 and NF-κB.</p> <p>Conclusion</p> <p>HIV-1 Tat protein causes increases in the paracellular permeability of RPE cells in vitro concomitant with changes in expression of certain transmembrane proteins associated with the tight junction. The effects of HIV-1 Tat on barrier function of the RPE may be mediated by ERK MAPK and NF-κB activation, which may represent potential targets for novel therapeutic approaches for the retinopathy induced by HIV infection.</p

Retromer Is Essential for Autophagy-Dependent Plant Infection by the Rice Blast Fungus

We thank Dr. Yizhen Deng at the Temasek Life sciences Laboratory (TLL) for providing the RFP-MoAtg8 plasmid. We would like to thank Drs. Zhenbiao Yang (University of California, Riverside) and Xianying Dou (Fujian Agriculture and Forestry University) for helpful discussions.Author Summary The rice blast fungus Magnaporthe oryzae utilizes key infection structures, called appressoria, elaborated at the tips of the conidial germ tubes to gain entry into the host tissue. Development of the appressorium is accompanied with autophagy in the conidium leading to programmed cell death. This work highlights the significance of the Vps35/retromer membrane-trafficking machinery in the regulation of autophagy during appressorium-mediated host penetration, and thus sheds light on a novel molecular mechanism underlying autophagy-based membrane trafficking events during pathogen-host interaction in rice blast disease. Our findings provide the first genetic evidence that the retromer controls the initiation of autophagy in filamentous fungi.Yeshttp://www.plosgenetics.org/static/editorial#pee

4-Cyclopropyl-1-(6&#8242;-deoxy-1&#8242;,2&#8242;-O-isopropylidene-&#945;-d-glucofuranosyl)-1H-1,2,3-triazole

In the title compound, C14H21N3O5, the tetrahydrofuran ring adopts an envelope conformation with the C atom bearing the substituent as the flap. The pentafuranose ring adopts a twisted conformation about the C&#8212;C bond fusing the rings. The dihedral angle between these rings (all atoms), which are cis fused, is 72.89&#8197;(14)&#176;. The cyclopropane ring is disordered over two orientations in a 0.576&#8197;(5):0.424&#8197;(5) ratio; the dihedral angles subtended to the triazole ring are 53.3&#8197;(11) and 46.6&#8197;(9)&#176;, respectively. In the crystal, the molecules are linked by O&#8212;H...N and O&#8212;H...O hydrogen bonds, generating (001) sheets. A weak C&#8212;H...O interaction also occurs

Frequency Scanning Dual-Mode Asymmetric Dual-OAM-Wave Generation Base on Broadband PB Metasurface

Increasing information capacity is significant for high-speed communication systems in a congested radio frequency sequence. Vortex waves carrying mode orthogonal orbital angular momentum (OAM) have gained considerable attention in recent years, owing to their multiplexing quality. In this study, a broadband Pancharatnam–Berry (PB) metasurface element with a simple structure is proposed, which exhibits an efficient reflection of the co-polarized component and a full 2π phase variation in 10.5–21.5 GHz under circularly polarized wave incidence. By convolution and addition operations, the elaborate phase distribution is arranged and the corresponding metasurface-reflecting dual-mode asymmetric dual-OAM waves is constructed. Under continuous control of the working frequency, the OAM vortex beams with the topological charges 1 and −1 are steered to scan within the angle range of 11.9°–24.9° and 17.9°–39.1° at φ = 315° and 135° planes, respectively. The simulation and measurement results verified the feasibility of generating frequency-controlled asymmetric dual beams and the validity of dual-mode OAM characteristics, both in the near and far fields. This design approach has considerable potential in OAM wave multiplexing and wireless communication system transmission