Academic literature on the topic 'DltX'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'DltX.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "DltX"

1

Poyart, Claire, Marie Cécile Lamy, Claire Boumaila, Franz Fiedler, and Patrick Trieu-Cuot. "Regulation of d-Alanyl-Lipoteichoic Acid Biosynthesis in Streptococcus agalactiae Involves a Novel Two-Component Regulatory System." Journal of Bacteriology 183, no. 21 (November 1, 2001): 6324–34. http://dx.doi.org/10.1128/jb.183.21.6324-6334.2001.

Full text
Abstract:
ABSTRACT The dlt operon of gram-positive bacteria comprises four genes (dltA, dltB, dltC, and dltD) that catalyze the incorporation of d-alanine residues into the lipoteichoic acids (LTAs). In this work, we characterized thedlt operon of Streptococcus agalactiae, which, in addition to the dltA to dltD genes, included two regulatory genes, designated dltR and dltS, located upstream of dltA. The dltR gene encodes a 224-amino-acid putative response regulator belonging to the OmpR family of regulatory proteins. The dltS gene codes for a 395-amino-acid putative histidine kinase thought to be involved in the sensing of environmental signals. The dlt operon ofS. agalactiae is mainly transcribed from the P dltR promoter, which directs synthesis of a 6.5-kb transcript encompassing dltR, dltS, dltA, dltB, dltC, and dltD, and from a weaker promoter, P dltA , which is located in the 3′ extremity ofdltS. We demonstrate that P dltR , but not P dlA , is activated by DltR in the presence of DltS in d-Ala-deficient LTA mutants resulting from insertional inactivation of the dltA gene, which encodes the cytoplasmic d-alanine-d-alanyl carrier ligase DltA. Expression of the dlt operon does not require DltR and DltS, since the basal activity of P dltR is high, being 20-fold that of the constitutive promoter P aphA-3 which directs synthesis of the kanamycin resistance gene aphA-3 in various gram-positive bacteria. We hypothesize that the role of DltR and DltS in the control of expression of the dlt operon is to maintain the level of d-Ala esters in LTAs at a constant and appropriate value whatever the environmental conditions. The DltA− mutant displayed the ability to form clumps in standing culture and exhibited an increased susceptibility to the cationic antimicrobial polypeptide colistin.
APA, Harvard, Vancouver, ISO, and other styles
2

Debabov, Dmitri V., Michael Y. Kiriukhin, and Francis C. Neuhaus. "Biosynthesis of Lipoteichoic Acid inLactobacillus rhamnosus: Role of DltD ind-Alanylation." Journal of Bacteriology 182, no. 10 (May 15, 2000): 2855–64. http://dx.doi.org/10.1128/jb.182.10.2855-2864.2000.

Full text
Abstract:
ABSTRACT The dlt operon (dltA to dltD) of Lactobacillus rhamnosus 7469 encodes four proteins responsible for the esterification of lipoteichoic acid (LTA) byd-alanine. These esters play an important role in controlling the net anionic charge of the poly (GroP) moiety of LTA.dltA and dltC encode thed-alanine–d-alanyl carrier protein ligase (Dcl) and d-alanyl carrier protein (Dcp), respectively. Whereas the functions of DltA and DltC are defined, the functions of DltB and DltD are unknown. To define the role of DltD, the gene was cloned and sequenced and a mutant was constructed by insertional mutagenesis of dltD from Lactobacillus casei102S. Permeabilized cells of a dltD::erm mutant lacked the ability to incorporate d-alanine into LTA. This defect was complemented by the expression of DltD from pNZ123/dlt. In in vitro assays, DltD bound Dcp for ligation with d-alanine by Dcl in the presence of ATP. In contrast, the homologue of Dcp, the Escherichia coli acyl carrier protein (ACP), involved in fatty acid biosynthesis, was not bound to DltD and thus was not ligated with d-alanine. DltD also catalyzed the hydrolysis of the mischarged d-alanyl–ACP. The hydrophobic N-terminal sequence of DltD was required for anchoring the protein in the membrane. It is hypothesized that this membrane-associated DltD facilitates the binding of Dcp and Dcl for ligation of Dcp with d-alanine and that the resultingd-alanyl–Dcp is translocated to the primary site ofd-alanylation.
APA, Harvard, Vancouver, ISO, and other styles
3

Beeh, K. M., O. Kornmann, J. Lill, and R. Buhl. "Induced sputum cell profiles in lung transplant recipients with or without chronic rejection: correlation with lung function." Thorax 56, no. 7 (July 1, 2001): 557–60. http://dx.doi.org/10.1136/thx.56.7.557.

Full text
Abstract:
BACKGROUNDSputum induction is a non-invasive procedure for measuring inflammatory processes of the lower respiratory tract. The aim of this study was to establish sputum cell counts and differentials in patients after lung transplantation (LTx), with or without chronic transplant rejection.METHODSSputum induction was performed in 41 LTx patients (25 single LTx (sLTx), 16 double LTx (dLTx) and 15 healthy non-smoking volunteers. Sputum was processed according to standard protocols. Total cell count was calculated as mean (SE) cells × 106/ml sputum and cell differential (%) was evaluated after staining. Cellular profiles were correlated with lung function.RESULTSTotal sputum cell counts were increased in sLTx (9 (1.9) cells × 106/ml, p=0.01) and dLTx patients (7.2 (1.5) × 106/ml, p=0.01) compared with healthy controls (2.6 (0.6) × 106/ml). There was also a marked sputum neutrophilia in both patient groups (59 (6)% and 62 (6)%, respectively, p<0.001v controls). Moreover, in both sLTx and dLTx patients with chronic transplant rejection there was an increased number of sputum neutrophils compared with patients with normal graft function (p<0.05 both comparisons), and neutrophils were inversely correlated with lung function (forced expiratory volume in one second (FEV1) % predicted): sLTx,r=–0.61, p=0.001; dLTx,r=–0.75, p=0.001, respectively). Sputum lymphocytes and eosinophils were similar in both groups. No relevant side effects occurred during sputum induction.CONCLUSIONSSputum induction is a safe and non-invasive tool for monitoring lower respiratory tract inflammation in LTx patients. Both sLTx and dLTx patients with chronic rejection had increased sputum neutrophils compared with patients with normal transplant function. These data support findings of other authors highlighting a possible role for neutrophils in the pathogenesis of chronic transplant rejection.
APA, Harvard, Vancouver, ISO, and other styles
4

Wood, B. McKay, John P. Santa Maria, Leigh M. Matano, Christopher R. Vickery, and Suzanne Walker. "A partial reconstitution implicates DltD in catalyzing lipoteichoic acid d-alanylation." Journal of Biological Chemistry 293, no. 46 (September 20, 2018): 17985–96. http://dx.doi.org/10.1074/jbc.ra118.004561.

Full text
Abstract:
Modifications to the Gram-positive bacterial cell wall play important roles in antibiotic resistance and pathogenesis, but the pathway for the d-alanylation of teichoic acids (DLT pathway), a ubiquitous modification, is poorly understood. The d-alanylation machinery includes two membrane proteins of unclear function, DltB and DltD, which are somehow involved in transfer of d-alanine from a carrier protein inside the cell to teichoic acids on the cell surface. Here, we probed the role of DltD in the human pathogen Staphylococcus aureus using both cell-based and biochemical assays. We first exploited a known synthetic lethal interaction to establish the essentiality of each gene in the DLT pathway for d-alanylation of lipoteichoic acid (LTA) and confirmed this by directly detecting radiolabeled d-Ala-LTA both in cells and in vesicles prepared from mutant strains of S. aureus. We developed a partial reconstitution of the pathway by using cell-derived vesicles containing DltB, but no other components of the d-alanylation pathway, and showed that d-alanylation of previously formed lipoteichoic acid in the DltB vesicles requires the presence of purified and reconstituted DltA, DltC, and DltD, but not of the LTA synthase LtaS. Finally, based on the activity of DltD mutants in cells and in our reconstituted system, we determined that Ser-70 and His-361 are essential for d-alanylation activity, and we propose that DltD uses a catalytic dyad to transfer d-alanine to LTA. In summary, we have developed a suite of assays for investigating the bacterial DLT pathway and uncovered a role for DltD in LTA d-alanylation.
APA, Harvard, Vancouver, ISO, and other styles
5

Du, Liqin, and Yu Luo. "Thiolation-enhanced substrate recognition by D-alanyl carrier protein ligase DltA from Bacillus cereus." F1000Research 3 (May 13, 2014): 106. http://dx.doi.org/10.12688/f1000research.4097.1.

Full text
Abstract:
D-alanylation of the lipoteichoic acid on Gram-positive cell wall is dependent on dlt gene-encoded proteins DltA, DltB, DltC and DltD. The D-alanyl carrier protein ligase DltA, as a remote homolog of acyl-(coenzyme A) (CoA) synthetase, cycles through two active conformations for the catalysis of adenylation and subsequent thiolation of D-alanine (D-Ala). The crystal structure of DltA in the absence of any substrate was observed to have a noticeably more disordered pocket for ATP which would explain why DltA has relatively low affinity for ATP in the absence of any D-alanyl carrier. We have previously enabled the thiolation of D-alanine in the presence of CoA as the mimic of D-alanyl carrier protein DltC which carries a 4’-phosphopantetheine group on a serine residue. Here we show that the resulting Michaelis constants in the presence of saturating CoA for both ATP and D-alanine were reduced more than 10 fold as compared to the values obtained in the absence of CoA. The presence of CoA also made DltA ~100-fold more selective on D-alanine over L-alanine. The CoA-enhanced substrate recognition further implies that the ATP and D-alanine substrates of the adenylation reaction are incorporated when the DltA enzyme cycles through its thiolation conformation.
APA, Harvard, Vancouver, ISO, and other styles
6

Davidsen, Jesper Rømhild, Hans Henrik Lawaetz Schultz, Daniel Pilsgaard Henriksen, Martin Iversen, Anna Kalhauge, Jørn Carlsen, Michael Perch, Ole Graumann, and Christian B. Laursen. "Lung Ultrasound in the Assessment of Pulmonary Complications After Lung Transplantation." Ultraschall in der Medizin - European Journal of Ultrasound 41, no. 02 (November 9, 2018): 148–56. http://dx.doi.org/10.1055/a-0783-2466.

Full text
Abstract:
Abstract Introduction Lung ultrasound (LUS) has a high diagnostic accuracy for identifying frequent conditions in the post-operative phase after lung transplantation (LTx). This study aimed to investigate the feasibility and clinical ability of LUS to identify pulmonary complications such as pleural effusions and pneumonias in the early postoperative phase after LTx. Methods A prospective cohort study of lung transplant recipients who consecutively underwent single LTx (SLTx) or double LTx (DLTx) at the National Lung Transplantation Center in Denmark from May 1 to October 31, 2015 was conducted. LUS was performed at four time points corresponding to post-transplant day 3, and weeks 2, 6, and 12 (LUS #1–4) to detect and monitor variation in pathological LUS findings over time. Concurrent with LUS #4, a high-resolution computed tomography examination of the thorax (HRCT) was also performed. Results 14 patients (1 SLTx/13 DLTx, 7 (50 %) women, mean age: 50.4 years) who had undergone the four prespecified LUS examinations were included. Pleural effusion was the most common condition and most pronounced at post-LTx week 2. Findings consistent with pneumonia increased during week 2 and subsequently decreased. Corresponding to LUS #1, 2, 3, and 4, pleural effusion occurred in 85.7 %, 92.9 %, 85.7 %, and 78.6 %, and pneumonia in 21.4 %, 28.6 %, 14.3 %, and 14.3 %, respectively. HRCT findings at post-LTx week 12 were predominantly presented by unspecific ground glass opacities. Conclusion In a post-LTx setting, LUS represents a clinical novelty as a feasible diagnostic and monitoring tool to identify pathological pulmonary complications in the early post-operative phase.
APA, Harvard, Vancouver, ISO, and other styles
7

Lee, In-Gyun, Chiman Song, Seoyeong Yang, Hanul Jeon, Jingyeong Park, Hye-Jin Yoon, Hookang Im, Sung-Min Kang, Hyun-Jong Eun, and Bong-Jin Lee. "Structural and functional analysis of the D-alanyl carrier protein ligase DltA from Staphylococcus aureus Mu50." Acta Crystallographica Section D Structural Biology 78, no. 4 (March 16, 2022): 424–34. http://dx.doi.org/10.1107/s2059798322000547.

Full text
Abstract:
D-Alanylation of the teichoic acids of the Gram-positive bacterial cell wall plays crucial roles in bacterial physiology and virulence. Deprivation of D-alanine from the teichoic acids of Staphylococcus aureus impairs biofilm and colony formation, induces autolysis and ultimately renders methicillin-resistant S. aureus highly susceptible to antimicrobial agents and host defense peptides. Hence, the D-alanylation pathway has emerged as a promising antibacterial target against drug-resistant S. aureus. D-Alanylation of teichoic acids is mediated via the action of four proteins encoded by the dlt operon, DltABCD, all four of which are essential for the process. In order to develop novel antimicrobial agents against S. aureus, the D-alanyl carrier protein ligase DltA, which is the first protein in the D-alanylation pathway, was focused on. Here, the crystal structure of DltA from the methicillin-resistant S. aureus strain Mu50 is presented, which reveals the unique molecular details of the catalytic center and the role of the P-loop. Kinetic analysis shows that the enantioselectivity of S. aureus DltA is much higher than that of DltA from other species. In the presence of DltC, the enzymatic activity of DltA is increased by an order of magnitude, suggesting a new exploitable binding pocket. This discovery may pave the way for a new generation of treatments for drug-resistant S. aureus.
APA, Harvard, Vancouver, ISO, and other styles
8

Koprivnjak, Tomaz, Vid Mlakar, Lindsey Swanson, Benedicte Fournier, Andreas Peschel, and Jerrold P. Weiss. "Cation-Induced Transcriptional Regulation of the dlt Operon of Staphylococcus aureus." Journal of Bacteriology 188, no. 10 (May 15, 2006): 3622–30. http://dx.doi.org/10.1128/jb.188.10.3622-3630.2006.

Full text
Abstract:
ABSTRACT Lipoteichoic and wall teichoic acids (TA) are highly anionic cell envelope-associated polymers containing repeating polyglycerol/ribitol phosphate moieties. Substitution of TA with d-alanine is important for modulation of many cell envelope-dependent processes, such as activity of autolytic enzymes, binding of divalent cations, and susceptibility to innate host defenses. d-Alanylation of TA is diminished when bacteria are grown in medium containing increased NaCl concentrations, but the effects of increased salt concentration on expression of the dlt operon encoding proteins mediating d-alanylation of TA are unknown. We demonstrate that Staphylococcus aureus transcriptionally represses dlt expression in response to high concentrations of Na+ and moderate concentrations of Mg2+ and Ca2+ but not sucrose. Changes in dlt mRNA are induced within 15 min and sustained for several generations of growth. Mg2+-induced dlt repression depends on the ArlSR two-component system. Northern blotting, reverse transcription-PCR, and SMART-RACE analyses suggest that the dlt transcript begins 250 bp upstream of the dltA start codon and includes an open reading frame immediately upstream of dltA. Chloramphenicol transacetylase transcriptional fusions indicate that a region encompassing the 171 to 325 bp upstream of dltA is required for expression and Mg2+-induced repression of the dlt operon in S. aureus.
APA, Harvard, Vancouver, ISO, and other styles
9

Klein, Uwe, Waheedullah Karzai, Frank Bloos, Mathias Wohlfarth, Reiner Gottschall, Harald Fritz, Michael Gugel, and Albrecht Seifert. "Role of Fiberoptic Bronchoscopy in Conjunction with the Use of Double-lumen Tubes for Thoracic Anesthesia." Anesthesiology 88, no. 2 (February 1, 1998): 346–50. http://dx.doi.org/10.1097/00000542-199802000-00012.

Full text
Abstract:
Background Fiberoptic bronchoscopy has been recommended to verify the position of double-lumen tubes (DLT), but this remains controversial. The authors studied the role of bronchoscopy for placing and monitoring right- and left-sided DLTs after blind intubation and after positioning the patient. Methods Two hundred patients having thoracic surgery requiring DLT insertion were prospectively studied. "Blind" tracheal intubations were done with 163 left-sided and 37 right-sided disposable polyvinyl chloride Robertshaw tubes. Bronchoscopy was performed by a different anesthesiologist after intubation and conventional clinical verification of correct placement and after patient positioning for thoracotomy. A DLT was considered malpositioned when it had to be moved &gt;0.5 cm to correct its position. Critical malpositions were those that might have affected patient safety or influenced the surgical procedure if left uncorrected. Results After "blind" DLT intubation, clinical evidence of malpositioning was found in 28 patients. This was confirmed by fiberoptic assessment. In 172 patients in whom placement was judged correct by clinical assessment, malpositioning was detected by bronchoscopy in 79 cases, 25 of which were critical. After patient positioning, DLTs were found to be displaced in 93 patients, 48 of which were critical. Right-sided DLTs were significantly more likely to be malpositioned than were left-sided DLTs. Two complications were related to unsatisfactory lung separation in the 200 patients studied. Conclusions After blind intubation and patient positioning, more than one third of DLTs required repositioning. Routine bronchoscopy is therefore recommended after intubation and after patient positioning.
APA, Harvard, Vancouver, ISO, and other styles
10

Zhong, Wei, Roberto Bugarini, Ling Wang, Cynthia Basu, and Darrin M. Beaupre. "Rethinking about the dose limiting toxicities (DLTs): They can be equivocal!" Journal of Clinical Oncology 37, no. 15_suppl (May 20, 2019): 3064. http://dx.doi.org/10.1200/jco.2019.37.15_suppl.3064.

Full text
Abstract:
3064 Background: The primary goal of oncology phase I trials is to determine the maximum tolerated dose (MTD) in a small number of patients. Within the standard design methodology currently employed there remains many challenges and one pertains to the variability around defining dose limiting toxicities (DLTs). The pre-specified DLT criteria may not well reflect the clinician’s practical experience with some adverse events, while others may actually be related to the disease status more than the investigational drug and could be misclassified. DLT misclassification seen in testing a small sample size from each dose group could generate a large bias on dose finding and the MTD estimation. Methods: To mitigate the risk of dichotomizing and misclassifying DLTs, we proposed a strategy that introduced the new concept of “equivocal” DLT or AE. A novel dose escalation approach is applied to increase the variability associated with less interpretable AEs so that the model recommendations are more weighted towards the unequivocal AEs/DLTs. To evaluate this novel approach, we established a framework incorporating two types of systematic measurement errors on DLT misclassification, one for the misclassified DLT that is not related to the drug treatment while the other for the non-DLT AE that should be considered severe and relevant to dose finding. In our simulation studies, the Bayesian logistic regression model (BLRM) was used to guide dose escalation in simulated trials to compare the novel weighting approach with the traditional approach. A few numerical examples were also included for method illustration. Results: For different types of measurement errors, simulation studies showed that the weighting approach could successfully improve the trial performance, with higher chance of finding the correct MTD and treating more patients at the MTD level. Conclusions: The DLT weighting strategy provides a flexible but powerful tool that may incorporate the clinician’s valuable experience on some specific DLTs/AEs and improve MTD estimation in oncology phase I dose-escalation trials.
APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic "DltX"

1

Kamar, Rita. "Mécanismes de résistance aux peptides antimicrobiens chez Bacillus thuringiensis : rôle de dltX dans la D-alanylation des acides téichoïques." Electronic Thesis or Diss., Paris, AgroParisTech, 2014. http://www.theses.fr/2014AGPT0029.

Full text
Abstract:
Le groupe Bacillus cereus est très hétérogène du point de vue toxicité et il est difficile de prédire le potentiel pathogène d'une souche. Dans ce travail, nous avons étudié les différents phénotypes de colonisation/adaptation à l'hôte, et analysé la corrélation entre ces phénotypes et les maladies humaines, pour une collection de souches représentatives de la diversité pathologique de B. cereus chez l'homme. L'analyse statistique a révélé des corrélations entre plusieurs phénotypes, et une analyse en composante principale a permis de regrouper les souches en deux sous-populations distinctes. Notre étude a ainsi permis de montrer qu'un ensemble de caractères phénotypiques liés au pouvoir pathogène permet de discriminer les souches présentant un historique en maladies infectieuses des souches sans historique. Nous pensons que ces résultats faciliteront l'identification d'un phénotype ou d’une combinaison de phénotypes qui pourraient être utilisés dans le développement de stratégies de prévention des infections par B. cereus. Le résultat de cette étude suggère que B. cereus n'est pas exclusivement un pathogène opportuniste et pourrait plutôt être considéré comme un véritable agent pathogène en soi.Cependant, la virulence est un phénomène multifactoriel impliquant de nombreux facteurs du côté de l'hôte ainsi que de celui de l'agent pathogène envahisseur. Les peptides antimicrobiens (PAMs) cationiques constituent les principales molécules effectrices de l’immunité innée. La résistance des microorganismes vis à vis de ces composés est donc nécessaire pour qu’ils puissent se développer dans l’hôte et exercer leur pouvoir pathogène. Par conséquent, de nombreuses bactéries pathogènes ont développé des stratégies de résistance impliquant la réduction des charges négatives de l’enveloppe bactérienne, réduisant ainsi l'interaction et la fixation de ces PAMs. L'incorporation de résidus D-alanine aux acides téichoïques (ATs) représente l'un des mécanismes les plus courants de résistance bactérienne qui dépendent de telles modifications. Ce processus de D-alanylation est accompli par les produits des gènes de l’opéron dlt. Celui-ci contient cinq gènes dltXABCD dont les séquences sont très conservées dans la quasi-totalité des bactéries à Gram-positif. La première ORF, dltX, code pour une protéine dont la fonction est inconnue. Le but de la seconde partie de ce travail était donc de déterminer si cette protéine est impliquée dans le processus de D-alanylation chez Bacillus thuringiensis. Pour cela, nous avons procédé à une délétion en phase du gène dltX, qui n’affecte pas l’expression des autres gènes de l'opéron. Les caractéristiques de croissance du mutant dltX et celles de la souche de type sauvage se sont avérées similaires in vitro. Cependant la délétion de dltX affecte considérablement la résistance de B. thuringiensis aux PAMs et atténue significativement sa virulence chez deux espèces d’insectes: Galleria mellonella et Drosophila melanogaster. En outre, une analyse HPLC montre que la paroie du mutant dltX est dépourvue de D-alanine, et la mesure de la mobilité électrophorétique indique que cette absence de D-alanylation est associée à un changement de la charge globale à la surface bactérienne. Des expériences de microscopie électronique à balayage montrent aussi des modifications morphologiques du mutant dltX, ce qui suggère que l'absence de D-alanine affecte également la structure de la paroi cellulaire. Nos résultats montrent que DltX est essentiel pour l'incorporation de la D-alanine aux acides téichoïques. Par ailleurs nous avons également démontré que dltX n’affecte pas l’expression de l’opéron dlt. Par conséquent nos résultats indiquent clairement que DltX joue un rôle direct dans la résistance aux PAMs, contribuant ainsi à la survie et la virulence de B. thuringiensis chez les insectes. Ce travail est le premier qui étudie la participation de dltX dans la D-alanylation des ATs
The Bacillus cereus pathogenic spectrum ranges from strains used as probiotics to human-lethal strains (causing gastrointestinal disorders or local and severe systemic infections). However, prediction of the pathogenic potential of a strain remains difficult. In this work, we studied different phenotypes of colonization/adaptation to the host (adhesion, cytotoxicity, motility, biofilm formation, resistance to antimicrobial peptides and virulence), analyzing the correlation between these phenotypes and human disease in a collection of strains representative of the pathological diversity of B. cereus in humans. Statistical analysis revealed correlations between several phenotypes, and principal component analysis grouped the strains into two distinct subpopulations. We found that strains differed in pathogenic potential and that virulent strains could be differentiated from non-pathogenic strains. We believe that these findings will facilitate the identification of a phenotype or a combination of phenotypes of potential use in the development of effective prevention strategies and/or diagnostic tools for distinguishing between pathogenic and non-pathogenic B. cereus strains. Our result suggests that B. cereus is not an exclusively opportunistic pathogen and could instead be considered a real pathogen per se. However, virulence is a multifactorial phenomenon involving numerous factors from both the host and the invading pathogen. As cationic antimicrobial peptides (CAMPs) are the primary defense mechanism against invading organisms, virulence of pathogens like B. cereus requires bacterial resistance to such compounds. Consequently, many pathogens have developed resistance strategies involving the reduction of the cell envelope negative charge, thereby influencing the binding and interaction of these CAMPs. The incorporation of Dalanine esters into teichoic acids (TAs) represents one of the most common bacterial resistance mechanisms that depend on such charge modifications. That D-alanylation process is accomplished by the gene products of an operon containing five genes, dltXABCD, that is highly conserved among nearly all gram-positive bacteria. The small first ORF, dltX, encodes a protein of unknown function. The aim of the other part of this work was then to establish whether this protein is involved in the D-alanylation process in Bacillus thuringiensis. We therefore constructed an in frame deletion mutant of dltX, without affecting the expression of the other genes of the operon. The growth characteristics of the dltX mutant and those of the wild type strain were similar under standard in vitro conditions. However disruption of dltX drastically impaired the resistance of B. thuringiensis to CAMPs and significantly attenuated its virulence in two insect species: Galleria mellonella and Drosophila melanogaster. Moreover, HPLC studies showed the dltX mutant was devoid of D-alanine, and electrophoretic mobility measurements indicated that the cells carried a higher negative surface charge. Scanning electron microscopy experiments showed morphological alterations of these mutant bacteria, suggesting that depletion of D-alanine from TAs affects cell wall structure. Our findings suggest that DltX is essential for the incorporation of D-alanyl esters into teichoic acids. Moreover, we found that DltX does not affect the expression of the operon. We therefore conclude that dltX is translated into a functional protein that plays a direct biosynthetic, transport or addresser role. Altogether, our results clearly indicate that DltX plays a direct role in the resistance to CAMPs, thus contributing to the survival and virulence of B. thuringiensis in insects. The exact function of that protein remains to be elucidated. This work is the first report examining the involvement of dltX in the Dalanylation of TAs
APA, Harvard, Vancouver, ISO, and other styles
2

Pfennig, Sabrina [Verfasser], Milton T. [Akademischer Betreuer] Stubbs, Ralph P. [Akademischer Betreuer] Golbik, and Norbert [Akademischer Betreuer] Sträter. "Strukturelle und thermodynamische Charakterisierung der DltA-DltC-Interaktion und kinetische Analyse der DltA katalysierten D-Alanylierung des DltC / Sabrina Pfennig. Betreuer: Milton T. Stubbs ; Ralph P. Golbik ; Norbert Sträter." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2015. http://d-nb.info/1073150704/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Allen, Darin. "Transcriptional regulation of the dlt operon in Enterococcus faecalis and further characterization of a dlta mutant." Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/783.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Zimmermann, Stephan [Verfasser], Milton T. [Akademischer Betreuer] Stubbs, J. [Akademischer Betreuer] Balbach, and H. D. [Akademischer Betreuer] Mootz. "Strukturelle Untersuchungen der Wechselwirkungen zwischen DltA und DltC / Stephan Zimmermann. Betreuer: Milton T. Stubbs ; J. Balbach ; H. D. Mootz." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2011. http://d-nb.info/1025231376/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Gurimskaya, Yana. "Comportement de quelques impuretés métalliques dans le germanium : une étude par les techniques capacitives DLTS-MCTS-LAPLACE DLTS." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00734375.

Full text
Abstract:
Ce travail consiste en une tentative de ré-examiner les propriétés électroniques du Fe, Cr et Au au sein de Ge, qui ont déjà été étudiées classiquement par DLTS (Deep Level Transient Spectroscopy). L'image générale qui en découle est que les métaux de transition dans Ge forment de manière prépondérante des centres accepteurs multiples, introduisant plusieurs niveaux profonds dans la bande de gap. A partir d'un modèle de liaison de valence simple, cette conclusion est en accord avec une survenue des impuretés sur des sites de substitution. Cependant, plusieurs questions demeurent ouvertes, comme le rôle de l'hydrogène en tant que contaminant dans l'élargissement des spectres DLTS. Notre contribution se base sur l'utilisation d'une approche plus performante nommée Laplace DLTS, en ce sens qu'elle autorise une meilleure résolution du signal. Nous présentons une analyse extensive par DLTS, MCTS et Laplace DLTS, afin d'étudier les propriétés électroniques des états accepteurs multiples, induits par les 4 métaux de transition sus-nommés. On distingue, parmis les paramètres étudiés, les barrières de capture des porteurs, les vraies sections efficaces de capture de sporteurs majoritaires (déterminées directement par la méthode de variation du pulse de remplissage), L'effet Pool-Frenkel (en lien avec la détermination de l'état de charge du niveau concerné). Ceci permet d'indiquer avec précision la position exacte des niveaux dans la bande interdite. Nous confirmons la plupart des résultats mis en évidence précédemment, tout en ajoutant quelques précisions sir le rôle de l'hydrogène dans la formation de nouveaux complexes. Une mise en parallèle avec le silicium. Dans le cas de Au, de nouveaux niveaux attribués aux complexes Au-Hn et Au-Sb sont observés. De manière générale, l'analyse des porteurs majoritaires et minoritaires par MCYS est toujours sujette à étude. En ce qui concerne le cas du Fe, la faible différence d'énergie entre ses deux niveaux soulève la possibilité d'un caractère de type U-négatif. L'ensemble de ses points devraient faire l'objet d'un travail approfondis dans un avenir proche.
APA, Harvard, Vancouver, ISO, and other styles
6

Djebbar, El-hocine. "A DLTS study of copper indium diselenide." Thesis, University of Salford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391312.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Marklund, Daniel. "Control of a high temperature DLTS setup." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-328710.

Full text
Abstract:
This thesis deals with a DLTS-setup and how this can be controlled. The controlling program is constructed in LABVIEW, where a previous built program measuring transients at varying pulses been handled and tried to be implemented for this setup. Parts of the program was implemented successfully, other part needs more work. The heater in the setup has further been connected directly to the sample. This one has been tested to see that the setup can handle the heat and that the difference between the temperature at the sample and the setup did not differ too much. The result showed that the difference was not so big. Finally, DLTS tests was performed at samples of silicon carbide as well as on diamond, where transients could be measured up to 723 °C on the silicon carbide sample, while the tests of diamond only gave noise.
APA, Harvard, Vancouver, ISO, and other styles
8

Jin, Gongjiu. "DLTS studies of surface state effects in GaAsFETs." Thesis, Lancaster University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316292.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Tabata, Americo Sheitiro. "Estudo de níveis profundos em GaAs usando DLTS." [s.n.], 1988. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278298.

Full text
Abstract:
Orientador: Marcio A.A. Pudensi
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
Made available in DSpace on 2018-07-17T14:01:56Z (GMT). No. of bitstreams: 1 Tabata_AmericoSheitiro_M.pdf: 727451 bytes, checksum: 6f553ad446b36fbefaabb37c21ce3d4a (MD5) Previous issue date: 1988
Resumo: Não informado
Abstract: Not informed.
Mestrado
Física
Mestre em Física
APA, Harvard, Vancouver, ISO, and other styles
10

Hellig, Kay. "Untersuchung tiefer Störstellen in Zinkselenid." [S.l. : s.n.], 1997. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10324521.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "DltX"

1

Mak, Ming Him. Construction of DLTS; gold in silicon. [s.l: The Author], 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sailer, Philip M. The DLX instruction set architecture handbook. San Francisco, Calif: Morgan Kaufmann Publishers, 1996.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Aschkenasy, David. An optimizing DLX assembly code scheduler. Corvallis, OR: Oregon State University, Dept. of Computer Science, 1998.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Catholic Fund for Overseas Development, ed. Out of the Ashes: CAFOD/DLT Lent book 2005. London: Darton Longman & Todd, 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Great Britain. Medical Devices Directorate., ed. An assessment of the imaging performance of the Elscint Gyrex V-DLX 0.5T MR imaging system. London: Department of Health, Medical Devices Directorate, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Masami, Ito, and Toyama Masafumi, eds. Developments in language theory: 12th international conference, DLT 2008, Kyoto, Japan, September 16-19, 2008 ; proceedings. Berlin: Springer, 2008.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

T, Harju, Karhumäki Juhani, and Lepistö Arto, eds. Developments in language theory: 11th International Conference, DLT 2007, Turku, Finland, July 3-6, 2007 : proceedings. Berlin: Springer, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Mauri, Giancarlo. Developments in Language Theory: 15th International Conference, DLT 2011, Milan, Italy, July 19-22, 2011. Proceedings. Berlin, Heidelberg: Springer-Verlag GmbH Berlin Heidelberg, 2011.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Dlta-P2 Complete Kit. The Psychological Corporation USA, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Lersmethasakul, Thanakrit. Dltm: Describe Less, Think More. Independently Published, 2019.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "DltX"

1

Gray, Gerald R. "DLT Standards." In Blockchain Technology for Managers, 165–72. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-85716-5_19.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Gray, Gerald R. "Global DLT Activity." In Blockchain Technology for Managers, 99–105. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-85716-5_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Pfister, Michelle, Niclas Kannengießer, and Ali Sunyaev. "Finding the Right Balance: Technical and Political Decentralization in the Token Economy." In Blockchains and the Token Economy, 53–86. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-95108-5_3.

Full text
Abstract:
AbstractToken economy instances can be built on a variety of protocols, such as distributed ledger technology (DLT) protocols. DLT protocols are used to operate DLT systems that perform, in a decentralized way, several tasks (e.g., the prevention of double-spending) that are usually handled by central actors, such as banks. Using DLT can be subject to challenges in terms of interoperability between DLT systems (e.g., due to incompatible interfaces), limiting the dynamics in token economy instances, for example, regarding collaboration between organizations operating on separate distributed ledgers. Cross-ledger interoperability (CLI) systems can connect DLT systems. However, it is unclear how the degree of decentralization (i.e., technical and political) of CLI systems affects token economy instances that comprise multiple DLT systems. To better understand such effects, we describe patterns for the implementation of CLI systems and present our notion of political decentralization in token economy instances using CLI. We describe potential implications of CLI patterns and governance mechanisms on token economy instances. Drawing from those implications, we discuss balancing centralization and decentralization in token economy instances that comprise multiple DLT and CLI systems.
APA, Harvard, Vancouver, ISO, and other styles
4

McLarty, Peter. "Deep Level Transient Spectroscopy (DLTS)." In The Kluwer International Series in Engineering and Computer Science, 109–26. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4613-1355-7_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Mueller, Silvia Melitta, and Wolfgang J. Paul. "A Sequential DLX Design." In Computer Architecture, 63–104. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04267-0_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Schmück, Kilian, and Oliver Gassmann. "DLT/Blockchain-basierte Geschäftsmodelle." In Digitale Transformation gestalten, 161–78. München: Carl Hanser Verlag GmbH & Co. KG, 2019. http://dx.doi.org/10.3139/9783446459632.012.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Bröring, Andre, Lukasz Wisniewski, and Alexander Belyaev. "Cross-Company Data Exchange with Asset Administration Shells and Distributed Ledger Technology." In Technologien für die intelligente Automation, 51–62. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-662-64283-2_4.

Full text
Abstract:
AbstractTo overcome boundaries in the cross-company data exchange, a new solution to use Distributed Ledger Technology (DLT) for the transfer of data between asset supplier and the Asset Administration Shell (AAS) in a remote repository is proposed in this paper. A short introduction to the AAS and an analysis of DLT in industrial context is given and showing useful properties for industrial usage as well as challenges to solve. The status of the exchange of AASs and possibilities to use DLT in supply chain tracking are described. The new solution combines both concepts by sending data through the distributed ledger from the supplier to the AAS. This is also shown in a proof-of-concept implementation of the solution using IOTA as a DLT and BaSyx as a framework for the AAS. The evaluation and discussion shows challenges and advantages from using the presented approach.
APA, Harvard, Vancouver, ISO, and other styles
8

Gray, Gerald R. "Matching DLT to Business Problems." In Blockchain Technology for Managers, 175–79. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-85716-5_20.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Mourouzis, Theodosis, and Nikolas Markou. "Blockchains, DLTs and the Future of Payments." In Future of Business and Finance, 21–28. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-78184-2_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Bogdanov, Alexander, Alexander Degtyarev, Alexey Uteshev, Nadezhda Shchegoleva, Valery Khvatov, and Mikhail Zvyagintsev. "A DLT Based Innovative Investment Platform." In Computational Science and Its Applications – ICCSA 2020, 72–86. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-58808-3_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "DltX"

1

Kenn, KK, BS Sczeapanski, BW Weber-Lange, MB Boensch, and DH Holle. "Comparing Effects of Early and Delayed Pulmonary Rehabilitation Following Single (SLTx) or Double (DLTx) Lung Transplantion." In American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a5379.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Nati, Michele. "IOTA ledger and IoT: A Secure Sustainable Infrastructure for the Construction Industry." In Construction Blockchain Conference 2021. Design Computation, 2021. http://dx.doi.org/10.47330/cbc.2021.zrvf8881.

Full text
Abstract:
The modern construction industry is all about connecting supply chains, workers and buildings. Internet of Things is one of the enabling technologies to provide more automation in this highly connected environment. However, more connectivity brings new opportunities but also more cyber-physical threats. In particular in relation to constrained IoT devices. Blockchain and decentralized identities can help to re-establish trust, improve security and develop new business models. Not all blockchains are equal and to guarantee the sustainability of the construction industry, any additional blockchain infrastructure needs to maintain a low carbon footprint. This talk will discuss the role of distributed ledgers (aka DLTs, aka blockchain) and in particular of the IOTA DLT in securing the connected construction industry and present some of the solutions and use cases currently being developed.
APA, Harvard, Vancouver, ISO, and other styles
3

Johnson, Matthew, Spencer Sevilla, Esther Jang, and Kurtis Heimerl. "dLTE." In HotNets '18: The 17th ACM workshop on Hot Topics in Networks. New York, NY, USA: ACM, 2018. http://dx.doi.org/10.1145/3286062.3286064.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Witkam, Toon. "DLT." In the 12th conference. Morristown, NJ, USA: Association for Computational Linguistics, 1988. http://dx.doi.org/10.3115/991719.991790.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Chinone, N., Y. Cho, R. Kosugi, Y. Tanaka, S. Harada, and H. Okumura. "Two-Dimensional Local Deep-Level Transient Spectroscopy Imaging Using Super-Higher-Order Scanning Nonlinear Dielectric Microscopy." In ISTFA 2016. ASM International, 2016. http://dx.doi.org/10.31399/asm.cp.istfa2016p0441.

Full text
Abstract:
Abstract A new technique for local deep level transient spectroscopy (DLTS) imaging using super-higher-order scanning nonlinear dielectric microscopy is proposed. Using this technique. SiCVSiC structure samples with different post oxidation annealing conditions were measured. We observed that the local DLTS signal decreases with post oxidation annealing (POA), which agrees with the well-known phenomena that POA reduces trap density. Furthermore, obtained local DLTS images had dark and bright areas, which is considered to show the trap distribution at/near SiCVSiC interface.
APA, Harvard, Vancouver, ISO, and other styles
6

Mitina, Nataliya, and Vladimir Krylov. "EXPERIMENTAL VERIFICATION OF DLTS MODELS." In CAD/EDA/SIMULATION IN MODERN ELECTRONICS 2019. Bryansk State Technical University, 2019. http://dx.doi.org/10.30987/conferencearticle_5e028210b72ba9.48046910.

Full text
Abstract:
The results of an experiment to determine the activation energy of a deep level in a gallium arsenide mesastructure, obtained by the method of capacitive deep levels transient spectroscopy with data processing according to the Oreshkin model and Lang model, are considered.
APA, Harvard, Vancouver, ISO, and other styles
7

Ashraf, William, Wayne Barry, and Sam McFarlane. "Towards Consistency: Digital Learning Thresholds." In HEAd'16 - International Conference on Higher Education Advances. Valencia: Universitat Politècnica València, 2016. http://dx.doi.org/10.4995/head16.2016.2724.

Full text
Abstract:
We report on the development of CCCU Digital Learning Thresholds (DLT). The principle aim of DLT is that all CCCU students have access to digital learning, and that all staff and students will have clear expectations about how, why and when to use digital learning. In addition DLT also align with and supports the VLE consistency agenda. In addition we have developed an innovative evaluation framework to assess the success of our DLT as well proposing their integrating into a blended learned model which emcompasses a quality assurance and enhancement pathway.
APA, Harvard, Vancouver, ISO, and other styles
8

Su, Xianrong, Ruisheng Zhang, Tongming Wei, Ruipeng Wei, and Lian Li. "Translating Gaussian03 AST into DLTK AST." In 2009 Eighth International Conference on Grid and Cooperative Computing (GCC). IEEE, 2009. http://dx.doi.org/10.1109/gcc.2009.50.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Sasongko, Danarto Tri, and Setiadi Yazid. "Integrated DLT and non-DLT system design for central bank digital currency." In SIET '20: 5th International Conference on Sustainable Information Engineering and Technology. New York, NY, USA: ACM, 2020. http://dx.doi.org/10.1145/3427423.3427447.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Yu, John P., Chengwei Lei, Duncan Wong, Jason Choi, and Jason Cotton. "Blockchain Applications in Oilfield Underground Injection Operations." In International Petroleum Technology Conference. IPTC, 2021. http://dx.doi.org/10.2523/iptc-21786-ms.

Full text
Abstract:
Abstract This research project has successfully built a Distributed Ledger Technology (DLT) based prototype using R3 Corda open source. Its purpose applies in the oil & gas underground injection control (UIC) operations for the underground aquifer protection. This DLT prototype is a permissioned network that allows oil & gas companies to create, disseminate, and trace immutable records. The network enables oil and gas companies, government regulatory agency, and all other participants to share secure records such as well information while maintaining data integrity, traceability, and security. The purpose is to create a network of trust among all the stakeholders in the UIC processes for underground aquifer protection. In this DLT network, a company submits well information, which will be digitally signed and notarized. Unauthorized changes to the information, ownership, or history will become infeasible, thanks to the underlying cryptographic technologies of DLT. The network designs so that information stored and communicated will have a high level of trustworthiness. Every participant in the network can get simultaneous access to a common view of the data. Corda platform also provides multiple functionalities, e.g., Smart contract, Vault, Identity Management, Scheduler, Notary Services, etc. Many of the functionalities automate the data processing within the DLT databases. This project's results expect to enhance public safety and improve the aquifer protection review and operational processes. Kern County uniquely poises for a project to develop more streamlined, effective, and entirely digitized DLT-based workflows that will secure regional environmental data integrity. Water contamination is a primary concern in a region where water and petroleum play vital roles in the economy. Both industries and regulatory agencies pay close attention to environmental quality. Data integrity is a primary issue concern for those that monitor and analyze environmental data. Monitoring and forecasting based on available immutable data are imperative to mitigate complications. We have changed the manual workflow into DLT applications which takes advantage of built-in functionalities. The new review process can avoid repetitive reviews among all participants and shorten the approval time. The embedded smart contracts on the DLT network will also help automate the workflows, and therefore, will be able to help eliminate human errors and improve the turnaround time. The prototype model proves the concept of using DLT. Our research work demonstrates DLT successfully implement into energy technology. The prototype model will further expand to all the UIC processes, such as thermal, wastewater disposal, waterflood, gas injection & disposal, etc. It is a substantial cost and time savings for all the oil and gas companies. The results of this analysis could provide the government with valuable information for significant policy and regulation decisions to further benefit the community and society.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "DltX"

1

Ioannou, Dimitris E. DLTS and Dynamic Transconductance Analysis of Deep-Submicron Fully- Depleted SOI MOSFET's. Fort Belvoir, VA: Defense Technical Information Center, June 1993. http://dx.doi.org/10.21236/ada267291.

Full text
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography