Simple Insertion Research Articles

Structural and electrochemical studies of a hexaphenylbenzene pyrolysed soft carbon as anode material in lithium batteries

XRD, SEM micrographs, BET analyses and typical electrochemical experiments (cyclic voltammetry, step voltammetry and Li insertion/deinsertion at constant current) have been carried out to characterize a new type of soft carbons obtained by pyrolysis of hexaphenylbenzene (HPB). By means of XRD and cyclic voltammetry at least three different type of sites for lithium storage were found. The first is graphite like type with d 002 graphene layer distance greater than pure graphite; the second is associated to disordered volumes among crystallities and the third is represented by Li sites at the hydrogen-terminated edges of hexagonal carbon fragments, characterized by higher energy in comparison with simple insertion sites. These last two types of sites are able to store some extra lithium, compared to pure graphite. BET analyses and cyclic voltammetries demonstrate the key role of the milling time on the characteristics and properties of this HPB pyrolysed carbon. Specific capacities shown by this pyrolysed material in Li coin-type cell have been also reported.

LORE1, an active low‐copy‐number TY3‐gypsy retrotransposon family in the model legume Lotus japonicus

We have identified a low-copy-number retrotransposon family present in nine to 10 copies in the Lotus japonicus model legume genome, and characterized its activity. LORE1 (Lotus retrotransposon 1) belongs to the Ty3-gypsy group of elements, and is a long terminal repeat (LTR) retrotransposon. Genetic mapping located LORE1 elements in gene-rich regions of Lotus chromosomes, and analysis of native as well as new insertion sites revealed integration outside the highly repetitive sequences of centromeres and telomeres. Sequencing of individual LORE1 family members identified several intact elements, and analysis of new insertions showed that at least one member is active and reinserts into functional genes, creating gene-disruption mutations. Southern blot analysis and SSAP on a selection of symbiotic mutants revealed up to 12 new insertion sites in individual mutant lines and a Mendelian segregation of new inserts. Expression analysis showed that LORE1 elements are transcribed in all organs analysed and, in contrast to other active retrotransposons, LORE1 appears not to be transcriptionally upregulated during in vitro tissue culture. Activity of LORE1 in callus and whole plants suggests that a simple insertion mutagenesis based on endogenous LORE1 elements can be established for Lotus.

Determination of arsenic(III) and total inorganic arsenic in water samples using an on-line sequential insertion system and hydride generation atomic absorption spectrometry

A simple and robust on-line sequential insertion system coupled with hydride generation atomic absorption spectrometry (HG-AAS) was developed, for selective As(III) and total inorganic arsenic determination without pre-reduction step. The proposed manifold, which is employing an integrated reaction chamber/gas–liquid separator (RC-GLS), is characterized by the ability of the successful managing of variable sample volumes (up to 25 ml), in order to achieve high sensitivity. Arsine is able to be selectively generated either from inorganic As(III) or from total arsenic, using different concentrations of HCl and NaBH 4 solutions. For 8 ml sample volume consumption, the sampling frequency is 40 h −1. The detection limit is c L = 0.1 and 0.06 μg l −1 for As(III) and total arsenic, respectively. The precision (relative standard deviation) at 2.0 μg l −1 ( n = 10) level is s r = 2.9 and 3.1% for As(III) and total arsenic, respectively. The performance of the proposed method was evaluated by analyzing the certified reference material NIST CRM 1643d and spiked water samples with various concentration ratios of As(III) to As(V). The method was applied for arsenic speciation in natural waters samples.

Complex gene rearrangements caused by serial replication slippage

The now-classical model of replication slippage can in principle account for both simple deletions and tandem duplications associated with short direct repeats. Invariably, a single replication slippage event is invoked, irrespective of whether simple deletions or tandem duplications are involved. However, we recently identified three complex duplicational insertions that could also be accounted for by a model of serial replication slippage. We postulate that a sizeable proportion of hitherto inexplicable complex gene rearrangements may be explained by such a model. To test this idea, and to assess the generality of our initial findings, a number of complex gene rearrangements were selected from the Human Gene Mutation Database (HGMD). Some 95% (20/21) of these mutations were found to be explicable by twin or multiple rounds of replication slippage, the sole exception being a double deletion in the F9 gene that is associated with DNA sequences that appear capable of adopting non-B conformations. Of the 20 complex gene rearrangements, 19 (seven simple double deletions, one triple deletion, two double mutational events comprising a simple deletion and a simple insertion, six simple indels that may constitute a novel and non-canonical class of gene conversion, and three complex indels) were compatible with the model of serial replication slippage in cis; the remaining indel in the MECP2 gene, however, appears to have arisen via interchromosomal replication slippage in trans. Our postulate that serial replication slippage may account for a variety of complex gene rearrangements has therefore received broad support from the study of the above diverse series of mutations.

Ease of insertion, contraceptive efficacy and safety of new T-shaped levonorgestrel-releasing intrauterine systems

Objective The objective of the study was to evaluate ease of insertion, contraceptive performance and safety, in parous and nulliparous women, of two new T-shaped levonorgestrel (LNG)-releasing intrauterine systems (LNG-IUS), Femilis™ (parous women) and Femilis™ Slim (nulliparous women), releasing 20 μg of LNG per day. An ancillary objective was to evaluate expulsion and user continuation. Design and methods An open, prospective, noncomparative study (interim analysis). Two hundred thirty-five insertions were performed in fertile women seeking contraception. Of these, 143 (60.8%) parous women were fitted with Femilis and 92 (39.2%) nulliparous women were fitted with Femilis Slim. The LNG-IUS was inserted using a simplified push-in technique (without folding the cross-arms in the insertion tube). Results This paper is the first report with the Femilis LNG-IUS. The push-in technique of insertion was considered simple and safe. Insertion was reported “easy” in virtually all women (97.9%). Pain at insertion was absent in 24.7% and “mild” in 67.7% of women. With respect to pain, there were no statistical differences between the parous and nulliparous group. At the time of study analysis, the total number of women-months of use was 1769.7. Seventy-six women had the Femilis IUS in place for periods in excess of 1 year. The study was well followed up with lost to follow-up of only two women. No pregnancies were observed. There was one expulsion in the nulliparous and one in the parous group. Ten removals were performed for medical reasons (mainly bleeding and pain). One pelvic infection occurred in a nulliparous woman caused by Chlamydia trachomatis, which was resolved without removing the IUS. There were no other serious adverse events reported. Both Femilis and Femilis Slim were well tolerated, which resulted in a high continuation rate (94.04%). Conclusion The Femilis LNG-IUS is an effective contraceptive and is easily inserted. The simple and safe insertion procedure could be an advantage for use by nonspecialist providers such as nurses, midwives, general practitioners, and for those not inserting intrauterine devices regularly. Femilis Slim could be an attractive long-term contraceptive option in young and adolescent women.

Modeling and Characterization of a Valved Glaucoma Drainage Device With Implications for Enhanced Therapeutic Efficacy

We report on modeling and bench test results targeted at better understanding of valved glaucoma drainage devices (GDDs), a common current surgical treatment for glaucoma. A simple equivalent circuit is described to model fluid mechanical behavior of the aqueous humor in an eye with glaucoma, both before and after implantation of a valved GDD. Finite element method simulations (FEM), based on the lubrication-von Kármán model, are then performed to analyze the valve's mechanical and fluidic performance. Using nanoporous membranes to mimic the in vivo fibrous capsule, we have developed a microfluidic bench test to simulate the aqueous humor flow and the post-implantation fibrous tissue encapsulation around the GDD back plate. Our numerical and bench test results show that, contrary to the prevailing belief, the valve significantly contributes to the total pressure drop even after fibrous capsule formation. Furthermore, we show that bypassing the valve through a simple polyimide tube insertion will dramatically lower the intraocular pressure (IOP) after fibrous capsule formation. This may offer a new treatment option in some patients with advanced glaucoma.

A cell forin situdynamic X-ray diffraction studies: application to the dehydration of zeolite SrX

A new compact cell forin situsynchrotron X-ray diffraction studies of adsorption or catalysis reactions has been designed to enable high performance whilst minimizing difficulties in use. It includes a system for simple insertion and alignment of capillary samples and an original miniaturized furnace providing excellent temperature homogeneity along the sample (temperature gradient less than 1 K over a 6 mm zone at 530 K). The efficiency of this setup is illustrated byin situcharacterization of a zeolite (SrX) at four hydration levels.

A novel laryngoscope instrument stabilizer for operative microlaryngoscopy

To evaluate and optimize the design of a removable and inexpensive internal stabilization device to reduce the effect of intention tremor during laryngeal microsurgery. In this laboratory investigation, stabilizers were designed and constructed to allow a nonobstructing view of the surgical field, permit simple insertion and removal, and accommodate microsurgical instruments. Prototype stabilizers were tested by using a Dedo laryngoscope, a measurement grid, and video recording equipment, which recorded instrument tremor within the magnified operative field for later analysis. Physicians also rated instrument stability, mobility, visualization, and ease of use on a survey form. Instrument tremor was reduced approximately 90%, with little obstruction of view of the surgical field. Instrument range of motion was reduced but improved rapidly as the stabilizer bar was moved further from the tip of the laryngoscope. Use of a stabilization device in the laryngoscope lumen reduces instrument tremor and has the potential to improve surgical performance during laryngeal microsurgery. B-3.

Anchorage of Synthetic Peptides onto Liposomes via Hydrazone and α-Oxo Hydrazone Bonds. Preliminary Functional Investigations

Synthetic peptidoliposomes have been designed and prepared according to a chemoselective ligation. Two aldehyde-functionalized lipidic anchors were synthesized and incorporated into the lipidic bilayers of unilamellar liposomes during their preparation. Complementary hydrazino acetyl peptides were synthesized on the solid phase using N,N',N'-tri(tert-butyloxycarbonyl)-hydrazino acetic acid and further coupled to the aldehyde groups displayed at the surface of the vesicles. Coupling yields were measured by amino acid hydrolysis following total acid hydrolysis. The ligation methodology proved superior to the simple insertion of lipopeptides, which was performed for comparison in terms of yields, implementation, and reproducibility. To check whether the grafted-peptides were accessible and functional, cytoplasmic sequences of LAMP protein (lysosomal associated membrane protein), which is involved in intracellular membrane trafficking, have been selected. Using this model, we demonstrated in vitro the specific interaction of the synthetic LAMP-peptidoliposomes with the cytoplasmic adaptor protein AP-3, a result that contributes to the understanding of protein sorting in cells. Thus, these results clearly indicate the usefulness of such peptidoliposomes, easily prepared by hydrazone chemoselective ligation, as a tool for biological investigation.

Combinatorial Bid Generation Problem for Transportation Service Procurement

In combinatorial auctions, solving the bid generation problem (BGP) for bidders is critical to achieving efficiency. However, in the recent surge of combinatorial auction research, little attention has been paid to the BGP. In this paper, the BGP faced by transportation service providers is studied. First, the bidder's optimality criterion of a combinatorial bid is clarified, and then the focus is on the bundling method when an OR bid language is used. Through examples, bundles generated by solving the optimal truck routing problem were examined, and it was found that the resulting bid might not be optimal. This heuristic is compared with a simple nearest insertion method. The simulation result shows that whereas the former outperforms the latter in most cases, many times the latter outperforms the former by 5% to 8%.

Combinatorial Bid Generation Problem for Transportation Service Procurement

In combinatorial auctions, solving the bid generation problem (BGP) for bidders is critical to achieving efficiency. However, in the recent surge of combinatorial auction research, little attention has been paid to the BGP. In this paper, the BGP faced by transportation service providers is studied. First, the bidder's optimality criterion of a combinatorial bid is clarified, and then the focus is on the bundling method when an OR bid language is used. Through examples, bundles generated by solving the optimal truck routing problem were examined, and it was found that the resulting bid might not be optimal. This heuristic is compared with a simple nearest insertion method. The simulation result shows that whereas the former outperforms the latter in most cases, many times the latter outperforms the former by 5% to 8%.

Intricate Knots in Proteins: Function and Evolution

A number of recently discovered protein structures incorporate a rather unexpected structural feature: a knot in the polypeptide backbone. These knots are extremely rare, but their occurrence is likely connected to protein function in as yet unexplored fashion. Our analysis of the complete Protein Data Bank reveals several new knots which, along with previously discovered ones, can shed light on such connections. In particular, we identify the most complex knot discovered to date in human ubiquitin hydrolase, and suggest that its entangled topology protects it against unfolding and degradation by the proteasome. Knots in proteins are typically preserved across species and sometimes even across kingdoms. However, we also identify a knot which only appears in some transcarbamylases while being absent in homologous proteins of similar structure. The emergence of the knot is accompanied by a shift in the enzymatic function of the protein. We suggest that the simple insertion of a short DNA fragment into the gene may suffice to turn an unknotted into a knotted structure in this protein.

Axial resolution in two-color excitation fluorescence microscopy by phase-only binary apodization

We study the effect of a kind of binary phase-only filters, the Toraldo filters, in two-color excitation fluorescence microscopy. We show that by simple insertion of a properly designed Toraldo filter in one of the illumination arms the axial resolution of the system is significantly improved. Specifically, the main peak of the point spread function is narrowed by 22% along the axial direction.

X-ray diffuser

Amorphous boron powder was used as an X-ray diffuser, making the beam divergence of synchrotron radiation broader by simple insertion of the diffuser into the beam. The diffuser has been used successfully for the purpose of easy peak finding on a four-circle diffractometer. The diffuser effect is considered to be brought about by small-angle scattering from the boron powder.

A piggyBac transposon gene trap for the analysis of gene expression and function in Drosophila.

P-element-based gene and enhancer trap strategies have provided a wealth of information on the expression and function of genes in Drosophila melanogaster. Here we present a new vector that utilizes the simple insertion requirements of the piggyBac transposon, coupled to a splice acceptor (SA) site fused to the sequence encoding enhanced green fluorescent protein (EGFP) and a transcriptional terminator. Mobilization of the piggyBac splice site gene trap vector (PBss) was accomplished by heat-shock-induced expression of piggyBac transposase (PBase). We show that insertion of PBss into genes leads to fusions between the gene's mRNA and the PBss-encoded EGFP transcripts. As heterozygotes, these fusions report the normal pattern of expression of the trapped gene. As homozygotes, these fusions can inactivate the gene and lead to lethality. Molecular characterization of PBss insertion events shows that they are single copy, that they always occur at TTAA sequences, and that splicing utilizes the engineered splice site in PBss. In those instances where protein-EGFP fusions are predicted to occur, the subcellular localization of the wild-type protein can be inferred from the localization of the EGFP fusion protein. These experiments highlight the utility of the PBss system for expanding the functional genomics tools that are available in Drosophila.

Directed evolution of ligand dependence: small-molecule-activated protein splicing.

Artificial molecular switches that modulate protein activities in response to synthetic small molecules would serve as tools for exerting temporal and dose-dependent control over protein function. Self-splicing protein elements (inteins) are attractive starting points for the creation of such switches, because their insertion into a protein blocks the target protein's function until splicing occurs. Natural inteins, however, are not known to be regulated by small molecules. We evolved an intein-based molecular switch that transduces binding of a small molecule into the activation of an arbitrary protein of interest. Simple insertion of a natural ligand-binding domain into a minimal intein destroys splicing activity. To restore activity in a ligand-dependent manner, we linked protein splicing to cell survival or fluorescence in Saccharomyces cerevisiae. Iterated cycles of mutagenesis and selection yielded inteins with strong splicing activities that highly depend on 4-hydroxytamoxifen. Insertion of an evolved intein into four unrelated proteins in living cells revealed that ligand-dependent activation of protein function is general, fairly rapid, dose-dependent, and posttranslational. Our directed-evolution approach therefore evolved small-molecule dependence in a protein and also created a general tool for modulating the function of arbitrary proteins in living cells with a single cell-permeable, synthetic small molecule.

Luxation intra-prothétique dans la cupule à double mobilité de Bousquet: À propos de 7 cas

Purpose of the study The Bousquet system is a dual mobility head-polyethylene polyethylene-metal cup socket. The polyethylene insert retaining the femoral head moves in the noncemented metal cup, increasing both mobility and stability. Material and method Between 1989 and 1997, seven cases of intra-prosthetic dislocation (six patients) were observed. The femoral head escaped from the polyethylene insert due to wear. On the average, this complication occurred ten years after implantation. Risk of dislocation was high in six of the seven hips. All patients had a large sized stem screwed into the femoral neck. There was a characteristic radiological aspect with loss of the concentric head metal cup configuration. The head was applied against the upper wall of the metal cup. Results Surgical replacement was undertaken early in six patients by simply changing the insert without modifying the other stable components. Outcome remained good at three to eight years. One patient underwent late surgery. The insert and the cup were replaced with a classical implant. Functional outcome was good but recurrent dislocation occurred. Discussion At mid-term, intra-prosthetic dislocation of dual mobility sockets appears to be exceptional. Dislocation results from polyethylene wear leading to failure of the insert to retain the prosthetic head. Wear is favored by direct phenomena (direct contact between neck and insert which can occur early if there is a small difference in the head and neck diameters) or indirect phenomena (factors limiting polyethylene metal-cup mobility). Surgical treatment is necessary. If undertaken early, replacement with a modular head and insert can be sufficient if the prosthesis has not loosened but the metal cup may have to be replaced in the event of metal-metal contact between the head and the cup. Prosthesis loosening, wear of the metal cup, or an identified cause of dislocation imply replacing the failing implants. Implantation of the dual mobility system is particularly interesting for patients with a high risk of dislocation or a chronically unstable hip prosthesis. Careful technique is required to reduce or retard the risk of intra-prosthetic dislocation. Conclusion Intra-prosthetic dislocation of a dual mobility socket is an exceptional complication at mid-term. Surgical treatment is required but may be limited to simple insert replacement. Systematic use of this type of implant in young subjects must be carefully examined, but for us, the risk of dislocation does not outweigh the advantages of this original concept of dual mobility. This type of socket remains an useful preventive technique for high-risk hips or for curative treatment of recurrent dislocation.

Fabrication of low-gate-current triode field emitters with planar carbon nanoparticle cathodes

We modified the structure of triode field emitters with planar carbon nanoparticle cathodes to reduce the gate currents. As it turned out, a simple insertion of an extra metal layer between the gate insulator and the cathode layer was sufficient for the substantial reduction of gate currents; the gate currents of the triode emitter with the modified structure never exceeded 4% of the anode currents up to anode currents of ∼250 nA, corresponding to a gate voltage of 67 V and an anode voltage 900 V. The fabrication of the modified triode structure required only four extra processing steps, compared to that of conventional triode structure, while using only conventional photolithography with a single mask. We were able to account for the gate-current reduction in terms of the modification in the electric field distribution.

Protective role for H-NS protein in IS1 transposition.

The transposase (InsAB') of the insertion element IS1 can create breaks in DNA that lead to induction of the SOS response. We have used the SOS response to InsAB' to screen for host mutations that affect InsAB' function and thus point to host functions that contribute to the IS1 transposition mechanism. Mutations in the hns gene, which codes for a DNA binding protein with wide-ranging effects on gene expression, abolish the InsAB'-induced SOS response. They also reduce transposition, whether by simple insertion or cointegrate formation, at least 100-fold compared with the frequency seen in hns+ cells. Examination of protein profiles revealed that in an hns-null mutant, InsAB' is undetectable under conditions where it constitutes the most abundant protein in hns+ cells. Likewise, brief labeling of the hns cells with [35S]methionine revealed very small amounts of InsAB', and this was undetectable after a short chase. Transcription from the promoters used to express insAB' was essentially unaltered in hns cells, as was the level of insAB' mRNA. A mutation in lon, but not in ftsH or clpP, restored InsAB' synthesis in the hns strain, and a mutation in ssrA partially restored it, implying that the absence of H-NS leads to a problem in completing translation of insAB' mRNA and/or degradation of nascent InsAB' protein.

The left end of IS2: a compromise between transpositional activity and an essential promoter function that regulates the transposition pathway.

Cut-and-paste (simple insertion) and replicative transposition pathways are the two classical paradigms by which transposable elements are mobilized. A novel variation of cut and paste, a two-step transposition cycle, has recently been proposed for insertion sequences of the IS3 family. In IS2 this variation involves the formation of a circular, putative transposition intermediate (the minicircle) in the first step. Two aspects of the minicircle may involve its proposed role in the second step (integration into the target). The first is the presence of a highly reactive junction formed by the two abutted ends of the element. The second is the assembly at the minicircle junction of a strong hybrid promoter which generates higher levels of transposase. In this report we show that IS2 possesses a highly reactive minicircle junction at which a strong promoter is assembled and that the promoter is needed for the efficient completion of the pathway. We show that the sequence diversions which characterize the imperfect inverted repeats or ends of this element have evolved specifically to permit the formation and optimal function of this promoter. While these sequence diversions eliminate catalytic activity of the left end (IRL) in the linear element, sufficient sequence information essential for catalysis is retained by the IRL in the context of the minicircle junction. These data confirm that the minicircle is an essential intermediate in the two-step transposition pathway of IS2.