Insertion Of New Material Research Articles

A potential space-making role in cell wall biogenesis for SltB1and DacB revealed by a beta-lactamase induction phenotype in Pseudomonas aeruginosa.

Inducible beta-lactamases like the ampC system of Pseudomonas aeruginosa are a common determinant of beta-lactam resistance among gram-negative bacteria. The regulation of ampC is elegantly tuned to detect defects in cell wall synthesis caused by beta-lactam drugs. Studies of mutations causing ampC induction in the absence of drug therefore promise to reveal new insights into the process of cell wall biogenesis in addition to aiding our understanding of how resistance to beta-lactam antibiotics arises in the clinic. In this study, the ampC induction phenotype for mutants lacking a glycan-cleaving enzyme or an enzyme that cuts cell wall crosslinks was used to uncover a potential role for these enzymes in making space in the wall matrix for the insertion of new material during cell growth.

Influence of impregnation time on TiO2 films sensitized with N719 and 2-Mercaptobenzothiazole: An electrochemical analysis

Dye sensitized solar cells (DSSC) are low-cost photovoltaic devices with easy production. They operate with a photoanode, a photocathode, and an electrolyte responsible for charge permeation within the cell. Recent research focus in DSSCs has aimed at enhancing their energy conversion properties, such as the insertion of new materials to reduce electronic recombination, utilization of gel electrolytes, dye synthesis, and studying cell assembly parameters. This study examined the effects of various immersion durations (6, 12, and 24 h) on TiO2 semiconductor films immersed in solutions containing charge carriers (N719 and 2-Mercaptobenzothiazole). To characterize the electrochemical properties, analyses such as current density versus potential curves (j-V), Electrochemical Impedance Spectroscopy (EIS), charge extraction, Intensity-Modulated Photovoltage (IMVS), and Photocurrent Spectroscopy (IMPS) were performed. It was found that the cell with 24 h of impregnation, presented a higher current density, consequently increasing efficiency (η = 5.76%). Impedance analyses showed that the 24-h samples facilitated charge transport, reducing cell resistance, consistent with charge extraction measurements. Lastly, IMPS and IMVS tests revealed that 24 h of immersion generated shorter collection times (τc = 0.016 ± 0.01) and longer electronic recombination times (τr = 0.07 ± 0.007), aiding the charge transport process.

Dataset of Specific Total Embodied Energy and Specific Total Weight of 40 Buildings from the Last Four Decades in the Andean Region of Ecuador

This article presents the Specific Total Embodied Energy (STEE) and Specific Total Weight (STW) of 40 Andean residential buildings in Ecuador, from 1980 to 2020. Firstly, the BoM of ten buildings of every decade was obtained through field work carried out in three urban sectors of this city. Secondly, the specific embodied energy and specific weight of every material found in the 40 samples were obtained by bibliography. Finally, the calculation of each building was divided into three components: Structure, Envelope and Finishes. The analyzed data show a detailed collection of different materials and construction typologies used in these four decades, and the impact on their embodied energy and their weight. Moreover, this article gives a Specific Embodied Energy and Specific Weight database of 25 materials that are extensively used in Andean regions. The results show several changes in reference to the insertion of new material, but also regarding the adoption of new architectonic models. The most important changes, in the analyzed period, have been the use of concrete and metal in the structure instead of wood, the increase in the glass surface in the envelope, and the replacement of wood by particleboard on the finishes. In conclusion, the STEE of the entire building has experienced an increase of 2.19 times in the last four decades. The STW value has also increased, but to a lesser extent (1.36 times).

Early midcell localization of Escherichia coli PBP4 supports the function of peptidoglycan amidases.

Insertion of new material into the Escherichia coli peptidoglycan (PG) sacculus between the cytoplasmic membrane and the outer membrane requires a well-organized balance between synthetic and hydrolytic activities to maintain cell shape and avoid lysis. Since most bacteria carry multiple enzymes carrying the same type of PG hydrolytic activity, we know little about the specific function of given enzymes. Here we show that the DD-carboxy/endopeptidase PBP4 localizes in a PBP1A/LpoA and FtsEX dependent fashion at midcell during septal PG synthesis. Midcell localization of PBP4 requires its non-catalytic domain 3 of unknown function, but not the activity of PBP4 or FtsE. Microscale thermophoresis with isolated proteins shows that PBP4 interacts with NlpI and the FtsEX-interacting protein EnvC, an activator of amidases AmiA and AmiB, which are needed to generate denuded glycan strands to recruit the initiator of septal PG synthesis, FtsN. The domain 3 of PBP4 is needed for the interaction with NlpI and EnvC, but not PBP1A or LpoA. In vivo crosslinking experiments confirm the interaction of PBP4 with PBP1A and LpoA. We propose that the interaction of PBP4 with EnvC, whilst not absolutely necessary for mid-cell recruitment of either protein, coordinates the activities of PBP4 and the amidases, which affects the formation of denuded glycan strands that attract FtsN. Consistent with this model, we found that the divisome assembly at midcell was premature in cells lacking PBP4, illustrating how the complexity of interactions affect the timing of cell division initiation.

Newness Touches Conventional History: The Research of the Photovoltaic Technology on a Wooden Church Heritage Building

The case study that determined the present research is the restoration of one Transylvanian wooden church from Cojocna, Cluj county, Romania. The original design (2018, Aqua Prociv Proiect Romanian company’s project) assumed all ICOMOS’s charters and the recommendation from this area in quality design, and it is in the stage of the execution auction. After nowadays standards, the restoration work does not need to achieve any form of energy efficiency, and its primordial target is the preservation of historical values and many other essentials for Humanity. The risk of museification of the heritage buildings with this architectural function, church, can sustain different and relevant points of view about the restoration, as could remark in the Leeuwarden Declaration (23 November 2018). There are some essential theoretical concepts linked or not to this specific domain, as art, history, or philosophy, otherwise that can sustain the potential of this kind of intervention. The insertion of new materials in heritage works is not in the current practice of restoration. However, there is a need to adapt to the in changing world and within his changing needs—evaluation on the evolution of some building parts in the context of the technological revolution. We propose a study for the change of finishing roof material with the maintenance of the roof geometry or structure. The new material is the PV solar roof tiles. The numerical values for electrical energy produced with photovoltaic technology will appear evaluated with a homemade computer program validated by comparison with dedicated software (PHPP_V9.6; PVsyst 6.8.6). Other arguments from theoretical and more subjective points of view will also notice. Conclusion: The research started in the nowadays context from the sustainability area, and one question that appears natural was about how close to regenerative design can be achieved through restoration works.

Bond strength assessment of a universal adhesive system in etch-and-rinse and self-etch modes

Abstract Introduction Modern dentistry is reflected in the insertion of new materials with different adhesion forms in dental structures, such as the Universal adhesive system. Objective To evaluate the bond strength of the universal dentin adhesive system, in the form of self-etching and conventional application, compared with a simplified conventional adhesive system, in two distinct periods: 1 week and 6 months. Material and method 48 bovine incisors separated into 6 groups, stored for 7 days, were selected. Worn out the buccal enamel until dentin exposure. Adper Single Bond 2 (3M Espe) or SingleBond Universal (3M Espe) adhesives were applied, and catheters filled with Opallis Flow (FGM) composite were placed. After photoactivation, the catheters were removed and the specimens (n = 48), stored in distilled water at 37 °C for one week and six months, were exposed. The specimens were fixed to a universal testing machine (EMIC DL 2000) with a speed of 0.5 mm / min. Bond strength (BS) was calculated in MPa, and data were statistically analyzed by Anova and Tukey test at 5% significance level. Result For Adper Single bond, the BS was equivalent in the times tested; for Universal conventional and self-conditioning time influenced the BS, with a decrease in the results. At 1 week, all stickers were different from each other, with higher BS for Universal conventional mode, followed by universal self-etching mode and then Adper Single bond. Conclusion The best results were achieved with universal adhesive in conventional mode for both tested times.

Superresolution microscopy reveals a dynamic picture of cell polarity maintenance during directional growth.

Polar (directional) cell growth, a key cellular mechanism shared among a wide range of species, relies on targeted insertion of new material at specific locations of the plasma membrane. How these cell polarity sites are stably maintained during massive membrane insertion has remained elusive. Conventional live-cell optical microscopy fails to visualize polarity site formation in the crowded cell membrane environment because of its limited resolution. We have used advanced live-cell imaging techniques to directly observe the localization, assembly, and disassembly processes of cell polarity sites with high spatiotemporal resolution in a rapidly growing filamentous fungus, Aspergillus nidulans. We show that the membrane-associated polarity site marker TeaR is transported on microtubules along with secretory vesicles and forms a protein cluster at that point of the apical membrane where the plus end of the microtubule touches. There, a small patch of membrane is added through exocytosis, and the TeaR cluster gets quickly dispersed over the membrane. There is an incessant disassembly and reassembly of polarity sites at the growth zone, and each new polarity site locus is slightly offset from preceding ones. On the basis of our imaging results and computational modeling, we propose a transient polarity model that explains how cell polarity is stably maintained during highly active directional growth.

Regulated proteolysis of a cross-link–specific peptidoglycan hydrolase contributes to bacterial morphogenesis

Bacterial growth and morphogenesis are intimately coupled to expansion of peptidoglycan (PG), an extensively cross-linked macromolecule that forms a protective mesh-like sacculus around the cytoplasmic membrane. Growth of the PG sacculus is a dynamic event requiring the concerted action of hydrolases that cleave the cross-links for insertion of new material and synthases that catalyze cross-link formation; however, the factors that regulate PG expansion during bacterial growth are poorly understood. Here, we show that the PG hydrolase MepS (formerly Spr), which is specific to cleavage of cross-links during PG expansion in Escherichia coli, is modulated by proteolysis. Using combined genetic, molecular, and biochemical approaches, we demonstrate that MepS is rapidly degraded by a proteolytic system comprising an outer membrane lipoprotein of unknown function, NlpI, and a periplasmic protease, Prc (or Tsp). In summary, our results indicate that the NlpI-Prc system contributes to growth and enlargement of the PG sacculus by modulating the cellular levels of the cross-link-cleaving hydrolase MepS. Overall, this study signifies the importance of PG cross-link cleavage and its regulation in bacterial cell wall biogenesis.

STEM-Based Characterization of Dislocations and Stacking Faults in Structural Materials

The national initiative on Integrated Computational Materials Engineering holds great promise for accelerating the insertion of new materials in high performance structural applications. Achieving this aim relies upon the fidelity of materials models and their ability to capture the connectivity between processing, microstructure and performance. Advancements in our ability to characterize deformation mechanisms at finer length-scales are providing new insights into the governing deformation mechanisms in several important structural materials are being developed

Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture

Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan, the target of antibiotics essential in modern healthcare. It consists of glycan strands, cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to turgor pressure and yet remains dynamic to allow insertion of new material, and hence growth. The cellular architecture and insertion pattern of peptidoglycan have remained elusive. Here we determine the peptidoglycan architecture and dynamics during growth in rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented bands of material interspersed with a more porous network. Super-resolution fluorescence microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present a consolidated model of growth via architecture-regulated insertion, where we propose only the more porous regions of the peptidoglycan network that are permissive for synthesis.

Rotate into shape: MreB and bacterial morphogenesis

Rotate into shape: MreB and bacterial morphogenesis

Understanding the Weathering Behaviour of Caen Stone

Microscopic study shows that Caen Stone varies in its petrographic structure between pellet-rich and bioclast-rich forms. The former is much more microporous than the latter, and tends to draw water into its structure if wetted. In historic usage, this has apparently led to more severe decay than is seen in the latter variety, which has generally displayed good durability. Examples of Caen Stone that survive on the exterior of medieval buildings have led to the material acquiring a good reputation, but less evident, poorer-quality medieval Caen Stone may also be found internally in remnant blocks, where surface decay was cut out for the insertion of new material in earlier episodes of repair. Both pellet-rich and bioclast-rich varieties are encountered in new stone available in the market, and are likely to be distinguishable in standard tests. The appended report on Caen Stone usage at the Palace of Westminster by Tim Yates which follows lends weight to this conclusion.

ICME at GE: Accelerating the insertion of new materials and processes

The accelerated insertion of materials (AIM) initiative provides the opportunity to reduce the materials development cycle time by up to 50% and thereby lessen the lead time required for new materials and processes. The program was founded to revolutionize the way designers and materials engineers interact, to achieve a leap forward in the application of computational materials science and integration with design engineering tools, and to create an environment where the design/materials team can learn from and build on previous developments. The centerpiece of the AIM system is the designer knowledge base, which provides a framework for managing experimental data, executing linked models describing processing, microstructure, properties, and producibility, and calculating confidence bounds for system predictions.

Characterization of a β-N-acetylglucosaminidase ofEscherichia coli and Elucidation of Its Role in Muropeptide Recycling and β-Lactamase Induction

Using the known mapping position the gene encoding a beta-1, 4-N-acetylglucosaminidase needed for the degradation of muropeptides could be identified. nagZ encodes a cytosolic enzyme active on N-actylglucosamyl-beta-1,4-(1,6)-anhydromuramic acid containing muropeptides. These degradation products of the peptidoglycan are formed during the enlargement of the murein sacculus as a consequence of a growth mechanism, which couples the controlled degradation of the cell wall polymer with the insertion of new material. NagZ is needed for the formation of monosaccharides from the released disaccharides during the cytosolic steps of the muropeptide-recycling pathway. The formation of intracellular 1, 6-anhydro-N-acetylmuramyl-peptides is important for the expression control of the inducible beta-lactamases of the AmpC type. A mutant lacking active NagZ cannot establish AmpC mediated beta-lactam resistance. The biochemical characterization of the enzyme showed its activity on different muropeptides and inhibitors of enzyme activity could be identified. This observation might be important for designing inhibitors of NagZ that could prevent the establishment of beta-lactam resistance of Enterobacteria possessing inducible beta-lactamases.

Cell surface patterning and morphogenesis: biogenesis of a periodic surface array during Caulobacter development.

Shape changes, extended processes, and other surface elaborations are associated with cellular differentiation, and the cell membranes involved with these developmental changes often are reshaped without a major alteration in biochemical composition. Caulobacter crescentus produces a hexagonally-packed periodic surface layer that covers the entire cell and further, mimics some of the membrane-mediated changes of higher organisms by forming a membranous stalk during its distinctive life cycle. Growth of the surface layer was examined during the cell cycle by treating synchronously growing cells with surface layer antibody, continuing growth, and then labeling for electron microscopy with a protein A-colloidal gold conjugate. Three regions of distinctive surface array biogenesis were resolved. The periodic surface layer on the main cell body was enlarged by insertion of new material at numerous uniformly distributed points. In contrast, the surface layer on the stalk appeared as entirely new synthesis. In examining growth of the stalk in subsequent generations, we noted that growth of stalk surface persisted at the stalk-cell body junction. The region of cell division also showed a pattern of entirely new surface layer production at late stages in division, similar to the stalk. The immunocytological method also facilitated a careful examination of stalk initiation and growth. Although initiation was under precise temporal and spatial regulation, the rate of stalk elongation was variable from cell to cell and apparently no longer under cell cycle control. The similarity of surface layer biogenesis on the stalk and the site of cell division may be a significant reflection of other events occurring at the cell pole. A model suggested by this and other studies that can account for the temporal pattern of polar morphogenesis is discussed, as is the potential relationship between the geometrically ordered surface array and the formation or maintenance of the stalk.

Coronary Heart Disease: Clinical, Angiographic and Pathologic Profiles.

The field of coronary artery disease is sorely in need of greater attention by radiologists. This book could provide much-needed stimulation with its superb cut-film reproductions which are a tribute to the demanding approach by Dr. Amplatz. The precise angiography shown is not often seen in treatises on this condition. Basically, the book is a large-format case atlas containing a profusion of radiographs, electrocardiograms, and pathological sections, and photomicrographs. Although it is primarily devoted to arteriosclerotic occlusive disease, there is also a section on congenital variants and anomalies. Large areas of unused space obviously allow for future insertion of new material in subsequent editions without increasing the size of the book, and I have found them useful for notes on my own cases. Line drawings are extensively used to explain the angiograms for the student who is unfamiliar with the appearance and position of the major vessels and their branches. Inside the front cover is a long list of abbreviations relating to the illustrations, which at first seems cumbersome, but once learned is a handy tool. A list of units for blood tests is also given to clarify clinical information used in the case presentations; however, it lacks the normal ranges for each, which would be helpful. The reproductions of gross and microscopic specimens are excellent, and there is a good correlation with the radiographs. However, some of the radiographs are not projections, such as the lateral view for right coronary injections, and the reader should bear this in mind. Although the RAO views of the right coronary injections tend to be steeper (45°) than those usually encountered clinically, there are nearly as many standard views in use today as there are coronary angiographers. Unfortunately, there are also quite a few mislabeled and reversed radiographs, and the uninitiated are advised to proceed with caution. A list of errata should be issued by the publisher. Also, I would like to have seen a more detailed discussion of the anomalous origin and course of the left coronary system between the pulmonary artery and aorta, as has been described in cases of sudden death in young people, particularly athletes. The electrocardiograms are generally clear and accurate and relate well to the cases presented. Some readers may use a different terminology, but this is a minor point. On the whole, the book is an excellent addition to the field and recommended to the practicing radiologist.

Coronary Heart Disease—Clinical, Angiographic and Pathologic Profiles

The field of coronary artery disease is sorely in need of greater attention by radiologists. This book could provide much-needed stimulation with its superb cut-film reproductions which are a tribute to the demanding approach by Dr. Amplatz. The precise angiography shown is not often seen in treatises on this condition. Basically, the book is a large-format case atlas containing a profusion of radiographs, electrocardiograms, and pathological sections, and photomicrographs. Although it is primarily devoted to arteriosclerotic occlusive disease, there is also a section on congenital variants and anomalies. Large areas of unused space obviously allow for future insertion of new material in subsequent editions without increasing the size of the book, and I have found them useful for notes on my own cases. Line drawings are extensively used to explain the angiograms for the student who is unfamiliar with the appearance and position of the major vessels and their branches. Inside the front cover is a long list of abbreviations relating to the illustrations, which at first seems cumbersome, but once learned is a handy tool. A list of standard units for blood tests is also given to clarify clinical information used in the case presentations; however, it lacks the normal ranges for each, which would be helpful. The reproductions of gross and microscopic specimens are excellent, and there is a good correlation with the radiographs. However, some of the radiographs are not standard projections, such as the lateral view for right coronary injections, and the reader should bear this in mind. Although the RAO views of the right coronary injections tend to be steeper (45°) than those usually encountered clinically, there are nearly as many "standard" views in use today as there are coronary angiographers. Unfortunately, there are also quite a few mislabeled and reversed radiographs, and the uninitiated are advised to proceed with caution. A list of errata should be issued by the publisher. Also, I would like to have seen a more detailed discussion of the anomalous origin and course of the left coronary system between the pulmonary artery and aorta, as has been described in cases of sudden death in young people, particularly athletes. The electrocardiograms are generally clear and accurate and relate well to the cases presented. Some readers may use a different terminology, but this is a minor point. On the whole, the book is an excellent addition to the field and recommended to the practicing radiologist.

Fragmentation in Nocardia corallina

SUMMARY: The growth cycle of Nocardia corallina involves a period of coenocytic hyphal development terminated by fragmentation. Hyphal elongation occurred by insertion of new material at the hyphal tips, not by intercalary growth. Exceptions occurred at points of branch initiation. Development of cross-walls preceded fragmentation and the new tips so produced were also capable of elongation. The fragmentation process appeared to be initiated by agents which accumulated in the medium, since used broth from actively fragmenting cultures stimulated earlier fragmentation in assay inocula. This effect was not shown by media from cultures in the coenocytic hyphal phase, nor by old resting cultures. The population density also affected fragmentation in a manner which suggested that accumulation of threshold concentrations of a diffusible metabolic product was required. A Millipore filter technique for assaying the effects of agents involved in fragmentation is described.

Evolution of Hydrodynamics

THE development of a book through successive editions is very like the evolution of a species. It has to adapt itself to changed circumstances by the insertion of new material; portions cease to be of explicit use, sometimes through the acquirement of new methods that do the work better, sometimes because their applications cease to exist. For economic reasons the book will survive better the more thoroughly the new adaptations are carried out and the superfluous parts eliminated. Nevertheless vestigial traces remain. Hydrodynamics. By Sir Horace Lamb. Sixth edition. Pp. xv + 738. (Cambridge: At the University Press, 1932.) 45s. net.