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A palladium-catalyzed interannular C–H amination of biaryl amines with O-benzoylhydroxylamines is reported, thus affording structurally diverse 2,2′-diaminobiaryls.

Using Cr(vi) as the imprinted ions and 2-allyl-1,3-diphenyl-1,3-propanedione (ADPD) (a compound synthesized by independent design) as the functional monomer, a series of chromium ion-imprinted composite membranes (Cr(vi)-IICMs) and corresponding non-imprinted composite membranes (NICMs) were synthesized and tested. The results showed that the Cr(vi)-IICM

By analyzing the photovoltaic parameters of organic solar cells based on perylene diimide (PDI) acceptors, we found that the power conversion efficiencies (PCEs) showed an approximately positive linear correlation with the fill factors (FFs), which were mainly determined by the morphology. To tune the morphology impacted by the molecular geometry of the donor and the acceptor, a fully fused PDI derivative F-2PDI-4F, wherein the adjacent bay positions of PDI were substituted by fluorine atoms, was rationally designed and synthesized. The repulsion of F⋯F reduced the coplanarity of PDI and created a dihedral angle of 12.6°, which endowed F-2PDI-4F with relatively weak crystallinity as compared to its analogue F-2PDI without fluorination. These two acceptors were incorporated with two polymer donors, PTB7-Th and PBDB-T, with varied crystallinities to fabricate a solar cell device. The performance showed that the combination of a highly crystalline donor (acceptor) and a weakly crystalline acceptor (donor) was beneficial for the improvement in FF due to the improved microstructure of the blend films. Thus, the device with PBDB-T and F-2PDI-4F achieved a high FF of 66.9% and the best PCE of 9.05%. F-2PDI-4F is one of the few examples among numerous PDI acceptors that can achieve PCEs exceeding 9%. Our study provides a fruitful avenue for applying electrostatic repulsion to modulate molecular geometry, consequently improving the optoelectronic properties of organic semiconductors.

Developing efficient all-polymer solar cells (all-PSCs) has always been a long-standing challenge due to the unfavorable morphology caused by conventional blend casting (BC). Here, we first employ the methodology of sequential processing (SP) with nonorthogonal solvents to fabricate facilely all-PSCs. A highly crystalline polymer donor, PBDB-T, is used to construct a well-organized underlying film, while a new polymer, FPDI-BT1, is selected as the acceptor to be intercalated into the amorphous or semicrystalline regions of PBDB-T during the secondary deposition. By tuning the solvent composition for FPDI-BT1 processing, a bulk heterojunction-like configuration, rather than a traditional bilayer device, is obtained facilely without the need of further processing treatment. The extremely boosted power conversion efficiency of 7.15% from the SP device is achieved, which is more than twice as efficient as the BC analogue (3.57%). The results demonstrate that SP is a promising strategy to fabricate high-performance all-PSCs with tunable configurations of active layers.

Lipid-protein particles originating from the plasma membrane were immunopurified from the cytosol of carnation petal cells (Dianthus caryophyllus L. cv. Improved White Sim) using antibodies raised against the central hydrophilic domain of the H + -ATPase. The immunopurified particles are enriched in lipid metabolites, in particular free fatty acids and steryl/wax esters, by comparison with corresponding microsomal membranes, and the lipids of the particles are more saturated than those of microsomal membranes. Proteolytic catabolites of the H + -ATPase, a protein associated with the plasma membrane, but not the native H + -ATPase protein, are also present in the immunopurified cytosolic particles. Osmiophilic particles were discernible in the cytosol of carnation petal cells by transmission electron microscopy, and the association of H + -ATPase catabolites with a subpopulation of these particles was confirmed by immunogold labelling with H + -ATPase antiserum. Cross-reaction of the H + -ATPase antiserum with elements of the cytosol was also evident by immunofluorescent light microscopy. These observations collectively indicate that lipid-protein particles of plasma membrane origin are present in the cytosol of carnation petal cells and that their formation may serve as a means of removing lipid and protein metabolites from the plasma membrane which would otherwise destabilize its structure.

The lipid bilayers of plant membranes are normally liquid crystalline, reflecting the inherent rotational motion of membrane fatty acids at physiological temperature. With the onset of senescence, the chemical composition of membrane lipids changes resulting in lipid phase separations within the bilayer. These phase changes render the membranes leaky and lead to loss of essential ion gradients and impairment of cell function. The separation of lipid phases appears to be attributable to an accumulation of lipid metabolites in the bilayer that are formed during turnover and metabolism of membrane lipids. These metabolites are normally released from membranes as lipid–protein particles found in the cell cytosol and within organelles. The lipid–protein particles also contain catabolites of membrane proteins and appear to serve as a vehicle for removing lipid and protein metabolites that would otherwise destabilize the bilayer. They bear structural resemblance to oil bodies, which are abundant in oil seeds, and have been found in leaves, cotyledons, and petals as well as in insect and animal tissue. The accumulation of lipid metabolites in senescing membranes and ensuing separation of lipid phases appear to reflect impairment of lipid–protein particle release from membranes as tissues age and to be a seminal cause of membrane dysfunction with advancing senescence. Key words: lipid bilayer, lipid phase separation, lipid–protein particles, membrane, oil body, senescence.

When the broad host range plasmid vector pGSS15 was used to genetically transform the plant growth promoting rhizobacterium Pseudomonas putida GR12-2, the transformants were physiologically debilitated. It was postulated that the expression of the β-lactamase gene of pGSS15 caused a metabolic load resulting in the impaired functioning of the bacterium. To test this hypothesis, derivatives of pGSS15 that either lack the β-lactamase gene (pYH122) or in which a β-glucosidase gene was substituted for the β-lactamase gene (pYH124) were constructed and examined to see whether their presence also impaired the functioning of P. putida GR12-2. On the basis of growth rates, siderophore production, and the ability to stimulate canola root elongation in sterile growth pouches, neither of the newly constructed plasmids debilitated P. putida GR12-2. In addition, P. putida GR12-2 transformed with pYH124 facilitated the proliferation of the bacterium in minimal medium containing cellobiose at low temperature. This latter trait may enable P. putida GR12-2 to persist in the soil in competition with other microorganisms.Key words: plant growth promoting rhizobacteria, PGPR, bacterial fertilizer, soil bacteria, metabolic load, β-glucosidase

Pseudomonas putida GR12-2, a plant growth promoting rhizobacterium, was transformed with the broad host range plasmid pGSS15. The presence of the plasmid caused (i) a decrease in cell generation times, (ii) an altered pattern of cell proteins, (iii) an inhibition of the enhancement of canola root elongation, (iv) impairment of nitrogen fixation, and (v) a decrease in siderophore production. Strains that were cured of pGSS15, on the other hand, re-established growth rates, levels of siderophore production, and canola root elongation capabilities equivalent to nontransformed P. putida GR12-2. Thus, the transforming plasmid imposes a metabolic load on the recipient bacteria that impacts on a number of different energy-dependent processes. Key words: plant growth promoting rhizobacteria, nitrogen fixation, Pseudomonas, transformation, metabolic load.

Inoculation of canola seeds withPseudomonas putida GR12-2 stimulates root elongation under gnotobiotic conditions. Transformation ofP. putida GR12-2 with the broad-host-range plasmid pGSS15 abolishes the enhancement of root elongation. With scanning electron microscopy it was found that both transformed and nontransformedP. putida GR12-2 are capable of binding to canola seed coats. In addition, it was observed that 4 days after the initial inoculation the roots of bothP. putida GR12-2- and GR12-2/pGSS15-treated seedlings were free of adhering bacteria despite the fact that it was subsequently shown that both bacterial strains are capable of binding to roots. Thus, adhesion to roots is not necessary for the initial phase of enhanced root elongation that is induced byP. putida GR12-2 under gnotobiotic conditions.

We report on the use of an electronic microarray to simultaneously type influenza A and B viruses and to distinguish influenza A virus subtypes H1N1 and H3N2 from the potentially pandemic avian virus subtype H5N1. The assay targets seven genes: the H1, H3, H5, N1, and N2 genes of influenza A virus; the matrix protein M1 gene of influenza A virus; and the nonstructural protein (NS) gene of influenza B virus. By combining a two-step reverse transcription-multiplex PCR with typing and subtyping on the electronic microarray, the assay achieved an analytical sensitivity of 10 2 to 10 3 copies of transcripts per reaction for each of the genes. The assay correctly typed and subtyped 15 different influenza virus isolates, including two influenza B virus, five A/H1N1, six A/H3N2, and two A/H5N1 isolates. In addition, the assay correctly identified 8 out of 10 diluted, archived avian influenza virus specimens with complete typing and subtyping information and 2 specimens with partial subtyping information. In a study of 146 human clinical specimens that had previously been shown to be positive for influenza virus or another respiratory virus, the assay showed a clinical sensitivity of 96% and a clinical specificity of 100%. The assay is a rapid, accurate, user-friendly method for simultaneously typing and subtyping influenza viruses.

Both plasmid pPFC4, which contains 10.6 kb, and a derivative of pPFC4—viz., pPFC4-4.6—which contains 4.6 kb ofPseudomonas fluorescens subsp.cellulosa DNA, direct the synthesis of six distinct endoglucanases inEscherichia coli. Two of these enzymes were purified to homogeneity in a single step by means of anion exchange HPLC. One enzyme has a molecular weight of 30.0 ± 1.0 kDa, an isoelectric point of 7.5, and a specific activity of 3470 U of activity/mg of protein, whereas the other has a molecular weight of 38.5 ± 1.0 kDa, an isoelectric point of 6.7, and a specific activity of 18,050 U of activity/mg of protein. On the basis of the amino acid composition, the 38.5 kDa enzyme appears to be a modified version of the 30.0 kDa enzyme. Thus, the multiplicity of endoglucanases produced inE. coli/pPFC4-4.6 cells may be owing to the posttranslational modification of a smaller number of primary translation products.

A subpopulation of plasma membrane vesicles enriched in membrane lipid metabolites has been isolated from petals of carnation flowers and leaves of canola seedlings. This was achieved by immuno-purification from a microsomal membrane preparation using region-specific antibodies raised against a recombinant polypeptide of the plasma membrane H + -ATPase. The properties of this subpopulation of vesicles were compared with those of purified plasma membrane isolated by partitioning in an aqueous dextran-polyethylene glycol two-phase system. The lipid composition of the immunopurified vesicles proved to be clearly distinguishable from that of phase-purified plasma membrane, indicating that they represent a unique subpopulation of plasma membrane vesicles. Specifically, the immunopurified vesicles are highly enriched in lipid metabolites, including free fatty acids, diacylglycerol, triacyl-glycerol and steryl and wax esters, by comparison with the phase-purified plasma membrane. These findings can be interpreted as indicating that lipid metabolites generated within the plasma membrane effectively phase-separate by moving laterally through the plane of the membrane to form discrete domains within the bilayer. It is also apparent that these domains, once formed, are released as vesicles into the cytosol, presumably by micro-vesiculation from the surface of the plasmalemma. Such removal may be part of normal membrane turnover.

A cDNA clone encoding a lipase (lipolytic acyl hydrolase) expressed at the onset of petal senescence has been isolated by screening a cDNA expression library prepared from carnation flowers ( Dianthus caryophyllus ). The cDNA contains the lipase consensus sequence, ITFAGHSLGA, and encodes a 447-amino acid polypeptide with a calculated molecular mass of 50.2 kDa that appears to be a cytosolic protein. Over-expression of the clone in Escherichia coli yielded a protein of the expected molecular weight that proved capable of deesterifying fatty acids from p -nitrophenylpalmitate, tri-linolein, soybean phospholipid, and Tween in both in vitro and in situ assays of enzyme activity. The abundance of the lipase mRNA increases just as carnation flowers begin to senesce, and expression of the gene is also induced by treatment with ethylene. Southern blot analyses of carnation genomic DNA have indicated that the lipase is a single copy gene. The lipase gene is also expressed in carnation leaves and is up-regulated when the leaves are treated with ethylene. Deesterification of membrane lipids and ensuing loss of membrane structural integrity are well established early events of plant senescence, and the expression pattern of this lipase gene together with the lipolytic activity of its cognate protein indicate that it plays a fundamentally central role in mediating the onset of senescence.

S100 is an acidic calcium-binding protein with a molecular weight of 21 000, originally discovered by Moore (1) in the bovine brain. Today, >14 different S100 members are known (2), of which S100A1 and S100B are the most studied (3)(4)(5)(6). Because a high concentration of S100B is present in the brain, S100 has been studied for use as a biochemical marker for central nervous system pathology. Numerous studies in the literature have suggested the clinical usefulness of measuring this protein in cerebrospinal fluid (7)(8)(9)(10)(11), and in recent years, serum S100B has been reported as a useful marker for early detection of metastases of melanoma and cerebral complications from head injury, cardiac surgery, and acute stroke (12)(13)(14)(15)(16)(17)(18)(19)(20)(21). With the advent of therapeutic treatments for stroke that either dissolve the clot or protect the brain, early diagnosis of stroke and the identification of appropriate patients for intervention are increasingly important. Existing assays lack sensitivity and ease of use and usually require ≥3 h to perform. We have, therefore, developed an ELISA that is rapid, highly sensitive, and S100B specific. This ELISA was used to retrospectively assess S100B concentrations in the serum of stroke patients. Human S100B cDNA (Genome System), amplified by PCR, was cloned into vector pET28a (Novagen) and expressed in Escherichia coli BL-21 (DE3)pLysS (Novagen). Recombinant human S100B (rS100B) was isolated from host cells that were induced with 1 mmol/L isopropylthio-β-galactoside for 2 h at 37 °C and were lysed with a native buffer system. S100B was purified with an Ni-NTA affinity column. The ELISA buffers were as follows: plate-coating buffer (100 mmol/L carbonate buffer, pH 9.6); phosphate-buffered …

Pulse-chase radiolabelling experiments have provided clear evidence for turnover of membrane lipids. Membrane lipid catabolites, however, have a propensity to destabilize bilayer structure, and this confounds an otherwise balanced process. Free fatty acids, for example, act as detergents and also phase-separate within bilayers [1]. It would seem likely, therefore, that lipid catabolites are removed from membranes such that they do not accumulate and compromise the structural integrity of the bilayer. Herein, we describe evidence indicating that lipid catabolites are voided from membranes by blebbing of lipid-protein particles that appear to be generically related to oil bodies, and propose that blebbing is an integral feature of membrane turnover.

Summary: A complete isoleucyl-tRNA synthetase gene (ileS) of Campylobacter jejuni was isolated from a C. jejuni TGH9011 genomic DNA library constructed in pBluescript. The complete coding sequence, flanking regions and transcription start point were determined. The deduced isoleucyl-tRNA synthetase (lleRS) had 917 amino acids with a molecular mass of 105399 Da, which was consistent with the observed size of 105 kDa in Escherichia coli maxicells. The ileS gene was mapped onto the physical map of the C. jejuni genome. Alignment of the C. jejuni lleRS sequence with six other bacterial lleRS sequences and two lower eukaryotic lleRS sequences identified seven conserved motifs, including the two signature sequences, HIGH and KMSKS, of class I aminoacyl-tRNA synthetases.