2,223 research outputs found
Poly[tetrakis(2,2′-bipyridine)undeca-μ-oxido-hexaoxidodicopper(II)hexavanadium(V)]
In the title organic–inorganic hybrid vanadate complex, [Cu2V6O17(C10H8N2)4]n, the CuII atom is six-coordinated by two chelating 2,2′-bipyridine (bipy) ligands and two vanadate O atoms in a distorted octahedral geometry. Two [Cu(bipy)2V3O8] units are linked by a bridging O atom, which lies on an inversion center, forming a dimeric unit. The dimeric units are further connected by bridging vanadate O atoms into a two-dimensional layer parallel to (100). The layers are connected by weak C—H⋯O hydrogen bonds
Gene expression profile analysis of tobacco leaf trichomes
<p>Abstract</p> <p>Background</p> <p>Leaf trichomes of <it>Nicotiana tabacum </it>are distinguished by their large size, high density, and superior secretion ability. They contribute to plant defense response against biotic and abiotic stress, and also influence leaf aroma and smoke flavor. However, there is limited genomic information about trichomes of this non-model plant species.</p> <p>Results</p> <p>We have characterized <it>Nicotiana tabacum </it>leaf trichome gene expression using two approaches. In the first, a trichome cDNA library was randomly sequenced, and 2831 unique genes were obtained. The most highly abundant transcript was ribulose bisphosphate carboxylase (RuBisCO). Among the related sequences, most encoded enzymes involved in primary metabolism. Secondary metabolism related genes, such as isoprenoid and flavonoid biosynthesis-related, were also identified. In the second approach, a cDNA microarray prepared from these 2831 clones was used to compare gene expression levels in trichome and leaf. There were 438 differentially expressed genes between trichome and leaves-minus-trichomes. Of these, 207 highly expressed genes in tobacco trichomes were enriched in second metabolic processes, defense responses, and the metabolism regulation categories. The expression of selected unigenes was confirmed by semi-quantitative RT-PCR analysis, some of which were specifically expressed in trichomes.</p> <p>Conclusion</p> <p>The expression feature of leaf trichomes in <it>Nicotiana tabacum </it>indicates their metabolic activity and potential importance in stress resistance. Sequences predominantly expressed in trichomes will facilitate gene-mining and metabolism control of plant trichome.</p
DIGAP - a Database of Improved Gene Annotation for Phytopathogens
<p>Abstract</p> <p>Background</p> <p>Bacterial plant pathogens are very harmful to their host plants, which can cause devastating agricultural losses in the world. With the development of microbial genome sequencing, many strains of phytopathogens have been sequenced. However, some misannotations exist in these phytopathogen genomes. Our objective is to improve these annotations and store them in a central database DIGAP.</p> <p>Description</p> <p>DIGAP includes the following improved information on phytopathogen genomes. (i) All the 'hypothetical proteins' were checked, and non-coding ORFs recognized by the Z curve method were removed. (ii) The translation initiation sites (TISs) of 20% ~ 25% of all the protein-coding genes have been corrected based on the NCBI RefSeq, ProTISA database and an <it>ab initio </it>program, GS-Finder. (iii) Potential functions of about 10% 'hypothetical proteins' have been predicted using sequence alignment tools. (iv) Two theoretical gene expression indices, the codon adaptation index (CAI) and the <it>E</it>(<it>g</it>) index, were calculated to predict the gene expression levels. (v) Potential agricultural bactericide targets and their homology-modeled 3D structures are provided in the database, which is of significance for agricultural antibiotic discovery.</p> <p>Conclusion</p> <p>The results in DIGAP provide useful information for understanding the pathogenetic mechanisms of phytopathogens and for finding agricultural bactericides. DIGAP is freely available at <url>http://ibi.hzau.edu.cn/digap/</url>.</p
(2E,5E)-2,5-Bis(3,4,5-trimethoxybenzylidene)cyclopentanone
The title compound, C25H28O7, was prepared by the base-catalysed reaction of 3,4,5-trimethoxybenzaldehyde with cyclopentanone. The molecule has crystallographic twofold rotation symmetry and adopts an E-configuration about the central olefinic bonds. The two benzene rings and the central cyclopentanone ring are almost coplanar [dihedral angle = 4.7 (2)°]
Ketamine Inhibits Lung Fluid Clearance through Reducing Alveolar Sodium Transport
Ketamine is a broadly used anaesthetic for analgosedation. Accumulating clinical evidence shows that ketamine causes pulmonary edema with unknown mechanisms. We measured the effects of ketamine on alveolar fluid clearance in human lung lobes ex vivo. Our results showed that intratracheal instillation of ketamine markedly decreased the reabsorption of 5% bovine serum albumin instillate. In the presence of amiloride (a specific ENaC blocker), fluid resolution was not further decreased, suggesting that ketamine could decrease amiloride-sensitive fraction of AFC associated with ENaC. Moreover, we measured the regulation of amiloride-sensitive currents by ketamine in A549 cells using whole-cell patch clamp mode. Our results suggested that ketamine decreased amiloride-sensitive Na+ currents (ENaC activity) in a dose-dependent fashion. These data demonstrate that reduction in lung ENaC activity and lung fluid clearance following administration of ketamine may be the crucial step of the pathogenesis of resultant pulmonary edema
Colorectal cancer screening with fecal occult blood test: A 22-year cohort study.
The aim of the present study was to investigate the efficacy of colorectal cancer (CRC) screening with a three-tier fecal occult blood test (FOBT) in the Chinese population. The study was performed between 1987 and 2008 at the Beijing Military General Hospital, in a cohort of army service males and females aged >50 years. Between 1987 and 2005, a three-tier screening program, comprising guaiac-based FOBTs (gFOBTs), followed by immunochemical FOBTs for positive guaiac test samples and then colonoscopy for positive immunochemical test subjects, was performed annually. The cohort was followed up until 2008. The cohort included 5,104 subjects, of which, 3,863 subjects participated in screening (screening group) and 1,241 did not (non-screening group). The two groups did not differ in age, gender or other major risk factors for colon cancer. Overall, 36 CRCs occurred in the screening group and 21 in the non-screening group. Compared with the non-screening group, the relative risk for the incidence and mortality of CRC was 0.51 [95% confidence interval (CI), 0.30-0.87] and 0.36 (95% CI, 0.18-0.71), respectively, in the screening group. The general sensitivity of this three-tier FOBT was 80.6% (95% CI, 65.3-91.1). Thus, annual screening using the three-tier FOBT program may reduce the CRC incidence and mortality rate
Visualizing the dynamic behavior of poliovirus plus-strand RNA in living host cells
Dynamic analysis of viral nucleic acids in host cells is important for understanding virus–host interaction. By labeling endogenous RNA with molecular beacon, we have realized the direct visualization of viral nucleic acids in living host cells and have studied the dynamic behavior of poliovirus plus-strand RNA. Poliovirus plus-strand RNA was observed to display different distribution patterns in living Vero cells at different post-infection time points. Real-time imaging suggested that the translocation of poliovirus plus-strand RNA is a characteristic rearrangement process requiring intact microtubule network of host cells. Confocal-FRAP measurements showed that 49.4 ± 3.2% of the poliovirus plus-strand RNA molecules diffused freely (with a D-value of 9.6 ± 1.6 × 10(−10) cm(2)/s) within their distribution region, while the remaining (50.5 ± 2.9%) were almost immobile and moved very slowly only with change of the RNA distribution region. Under the electron microscope, it was found that virus-induced membrane rearrangement is microtubule-associated in poliovirus-infected Vero cells. These results reveal an entrapment and diffusion mechanism for the movement of poliovirus plus-strand RNA in living mammalian cells, and demonstrate that the mechanism is mainly associated with microtubules and virus-induced membrane structures
EFFECTS OF LONG-TERM TAI CHI EXERCISE ON BALANCE CONTROL IN OLDER ADULTS
This study assessed the static and dynamic balance control of older adults who have 10 years of Tai Chi exercise experience and compared their characteristics with their sedentary counterparts. The abilities were measured using methods: single-leg stance times with eyes open and closed; sway of center of pressure (COP) during static standing with eyes open/closed, and leaning the body in three specific directions. Compared with control group, 1) Tai Chi Group showed longer single-leg stance times with eyes open and closed, 2) slower sway velocity of COP in mediolateral and anterioposterior directions and shorter sway distance in both directions, and 3) shorter total, anterioposterior, and mediolateral routes and shorter time spent during the dynamic balance test. Long-term Tai Chi exercise improves the balance ability, especially the dynamic balance, of older adults
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