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Charge transporting nanostructured polymers for electrochemical systems – a themed collection
No full textGuest editors Shrayesh N. Patel and Nitash P. Balsara introduce this themed collection on charge transporting nanostructured polymers for electrochemical systems
Investigations of Streptomyces coelicolor A3(2) siderophore binding proteins
No full textSiderophores are small, high-affinity ferric iron chelators released by many microorganisms and some plants to solubilize iron. They are of great interest due to their clinical use to treat iron overload in humans, and also in relation to the development of novel antibiotics that target the biosynthetic and uptake pathways for iron in pathogens. Pathogens such as Bacillus anthracis excrete more than one type of siderophore. This is linked to increased pathogenicity. The Gram-positive soil bacterium Streptomyces coelicolor A3(2) excretes three siderophores: desferrioxamine B, desferrioxamine E and coelichelin. These displace iron from insoluble ferric hydroxides, and the resulting ferric complexes are transported into the cell via siderophore-binding proteins (lipoprotein receptors) associated with ATP-binding cassette (ABC) transporters. Previous studies showed that some of the genes in the biosynthetic clusters of the desferrioxamines (des) and coelichelin (cch) were required for efficient uptake of ferrioxamine E and ferri-coelichelin respectively and a third ABC transporter gene cluster (cdt), not associated with siderophore biosynthesis genes, was implicated in the import of ferrioxamine B. In this study, the lipoprotein receptors encoded within the des, cch and cdt clusters - DesE, CchF and CdtB – were recombinantly overproduced in E. coli and purified by immobilized metal affinity chromatography. Also, ferri-coelichelin was purified from cultures of S. coelicolor. The binding of the ferric complexes of the three cognate siderophores, as well as the xenosiderophores ferrichrome and ferrialbomycin, to the lipoprotein receptors was monitored by intrinsic fluorescence quenching. Dissociation constants of receptor-siderophore complexes were found to be in the nanomolar range, and a revised model of cognate siderophore transport in S. coelicolor was proposed. In collaboration with researchers at St. Andrews University, an X-ray crystal structure was solved for apo-DesE and DesE bound to ferrioxamine B, which demonstrated the similarity of DesE to other bacterial siderophore-binding proteins and the negligible conformational change on substrate binding. Ferrioxamine B also exhibited an unusual configuration not observed before in X-ray crystals of this ferri-siderophore. Also, a forcefield was constructed to model the structure and distortions ferric-tris-hydroxamate complexes, which could be used in the future to investigate the molecular basis of the tight and specific binding of ferri-siderophores to siderophore-binding proteins
Figure 2. A–C. Habits. —A. Phegopteris excelsior N. R. Patel & A. V in Phegopteris excelsior (Thelypteridaceae): A New Species of North American Tetraploid Beech Fern
No full textFigure 2. A–C. Habits. —A. Phegopteris excelsior N. R. Patel & A. V. Gilman (Gilman 98067 & Lambert, VT). —B. Phegopteris connectilis (Michx.) Watt. (Gilman 2K123, VT). —C. Phegopteris hexagonoptera (Michx.) Fée (Gilman 2K082, VT). D–F. Close-ups of basal pinnae. —D. Phegopteris connectilis (Gilman 2K123, VT). —E. Phegopteris excelsior (Gilman 98067 & Lambert, VT). —F. Phegopteris hexagonoptera (House 289434, UC). The approximate basal pinnae length:width ratio for P. hexagonoptera is 3:1, for P. connectilis 4:1, and for P. excelsior 5:1. The basal pinnae of P. connectilis and P. excelsior are usually widest below the middle, and those of P. connectilis are usually widest above the middle.Published as part of Patel, Nikisha R., Fawcett, Susan & Gilman, Arthur V., 2019, Phegopteris excelsior (Thelypteridaceae): A New Species of North American Tetraploid Beech Fern, pp. 211-218 in Novon, A Journal for Botanical Nomenclature 27 (4) on page 215, DOI: 10.3417/2019409, http://zenodo.org/record/456191
Deaminating Enzymes of the Purine Cycle as Biocatalysts for Chemo-enzymatic Synthesis and Transformation of Antiviral Agents Structurally Related to Purine Nucleosides
No full textPurine nucleosides that are modified in the base or the furanose moiety and carbocyclonucleosides or acyclonucleosides often present antiviral activity. Their preparation can involve biocatalytic procedures, including use of deaminating enzymes of the purine cycle such as adenosine deaminase (ADA) and adenylic acid deaminase (AMPDA). These enzymes, that are able to catalyze the hydrolytic deamination of various purine nucleosides and analogues, can be actually considered as valuable biocatalysts in nucleoside chemistry. Applications to the chemo-enzymatic preparation and transformation of compounds endowed with antiviral activity will be reviewed and discussed
Synthesis, electrical transport mechanisms and photovoltaic characteristics of p-ZnIn2Se4/n-CdTe thin film heterojunction
No full textThe synthesis and electrical transport features of vacuum-deposited p-ZnIn2Se4/n-CdTe (p-ZIS/n-CT) heterojunction diode (HJD) are discussed. Transmission electron microscopy (TEM) was used to characterize the microstructures of p-ZIS and n-CT thin films. The Hall measurement system determined the conductivity and carrier concentration of the ZIS and CT films; the acceptor concentration (Na) for ZIS film and donor concentration (Nd) for CT film observed are 4.12×1013cm-3 and 2.80×1014cm-3, respectively. The DC electrical resistance (R) variation with temperature (T) determines thermal activation (impurity-based conduction) and bandgap energies of p-ZIS and n-CT thin films. Scanning electron microscopy (SEM) was used to look at the surface morphology of p-ZIS / n-CT HJD. The semiconductor characterization system (SCS-4200) was used to characterize the current–voltage (I- V) and capacitance–voltage (C–V) of the p-ZIS / n-CT HJD at different T (303-340K). The p-ZIS / n-CT HJD ’s dark I- V finding shows conventional diode nature with a decent rectification ratio (RR) (≃4.34×105at±2.0V). At a given bias, the RR value drops as T increases. The systematic assessment of I- V data suggests the thermionic emission (TE) mechanism at lower bias and the space charge-limited conduction (SCLC) mechanism at higher bias. The quantitative analysis estimates the barrier height (φb) as ≃0.79eV (from I- V measurements) and ≃0.88eV (from C–V measurements). Cheung’s function was utilized to derive the φb, ideality factor (n) and the series resistance (Rs) of the p-ZIS/n-CT HJD. With a rise in T, HJD’s saturation current (Is), n and φb rise, whilst, Rs falls. To gain insight into depletion behaviour, a study examined space charge and electric field distributions for abrupt p-ZIS/n-CT HJD. The experimental findings of Anderson’s model corroborate a theoretical energy band diagram for the p-ZIS/n-CT HJD. The p-ZIS/n-CT HJD’s photovoltaic (PV) characterization resulted in a 0.51 fill factor and 1.04% efficiency. The implications are discussed
DS_10.1177_2380084418812886 – Supplemental material for Unconscious Racial Bias May Affect Dentists’ Clinical Decisions on Tooth Restorability: A Randomized Clinical Trial
No full textSupplemental material, DS_10.1177_2380084418812886 for Unconscious Racial Bias May Affect Dentists’ Clinical Decisions on Tooth Restorability: A Randomized Clinical Trial by N. Patel, S. Patel, E. Cotti, G. Bardini and F. Mannocci in JDR Clinical & Translational Research</p
P-Doped Porous Carbon as Metal Free Catalysts for Selective Aerobic Oxidation with an Unexpected Mechanism
No full textAn extremely simple and rapid (seconds) approach is reported to directly synthesize gram quantities of P-doped graphitic porous carbon materials with controlled P bond configuration. For the first time, it is demonstrated that the P-doped carbon materials can be used as a selective metal free catalyst for aerobic oxidation reactions. The work function of P-doped carbon materials, its connectivity to the P bond configuration, and the correlation with its catalytic efficiency are studied and established. In direct contrast to N-doped graphene, the P-doped carbon materials with higher work function show high activity in catalytic aerobic oxidation. The selectivity trend for the electron donating and withdrawing properties of the functional groups attached to the aromatic ring of benzylic alcohols is also different from other metal free carbon based catalysts. A unique catalytic mechanism is demonstrated, which differs from both GO and N-doped graphene obtained by high temperature nitrification. The unique and unexpected catalytic pathway endows the P-doped materials with not only good catalytic efficiency but also recyclability. This, combined with a rapid, energy saving approach that permits fabrication on a large scale, suggests that the P-doped porous materials are promising materials for “green catalysis” due to their higher theoretical surface area, sustainability, environmental friendliness and low cost.This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acsnano.5b07054.Peer reviewe
Unconscious Racial Bias May Affect Dentists’ Clinical Decisions on Tooth Restorability:A Randomized Clinical Trial
No full textMethods: In this single-center cross-sectional survey, 57 dentists were given a clinical scenario in combination with a patient’s relevant clinical photographs and radiographs depicting either a Black or White patient presenting with a decayed tooth and associated symptoms of irreversible pulpitis. Explicit bias was measured through a questionnaire, which evaluated participants’ course of treatment, strength of recommendation, and their perception of patients’ dental cooperativeness. Implicit bias was evaluated through brief implicit associate tests. Results: Recommendation for root canal treatment (RCT) in the White patient condition was significantly higher than in the Black patient condition (χ2 = 4.77, P < 0.05). Overall, participants were significantly more likely to recommend root canal treatment to White patients (t = 2.46, P = 0.0172) and significantly more likely to recommend extraction for Black patients (t = 3.03, P = 0.0034). In total, 91.23% and 78.95% of all participants displayed high Brief Implicit Association Test race and cooperation scores, respectively, showing a pro-White bias in both categories. This trend was shown to be irrespective of the patient condition. Conclusions: Dentists’ decision making was affected by the race of the patient, resulting in a greater likelihood of extractions (less RCT) for Black patients presenting with a broken-down tooth and symptoms of irreversible pulpitis. Knowledge Transfer Statement: The results of this study can be used by clinicians to understand the impact that unconscious racial bias may have on their treatment planning decisions. This information can create awareness, thereby reducing the impact that potential biases can have on the treatment patients receive.</p
Natalie Coural : Les Patel. Pierre Patel (1605-1676) et ses fils. Le paysage de ruines à Paris au 17e siècle. Préface de Jacques Thuillier, 2001
No full textMoureau François. Natalie Coural : Les Patel. Pierre Patel (1605-1676) et ses fils. Le paysage de ruines à Paris au 17e siècle. Préface de Jacques Thuillier, 2001. In: Dix-huitième Siècle, n°34, 2002. Christianisme et Lumières, sous la direction de Sylviane Albertan-Coppola et Antony McKenna. p. 701
Tirmilyra concinnus Patel & Naderloo & Trivedi & Mitra 2023, n. comb.
No full text<i>Tirmilyra concinnus</i> (Ghani & Tirmizi, 1995) n. comb. <p>(Figs. 1E, F, 2C, D, 3C, D, 4E, F)</p> <p> <i>Philyra concinnus</i> Ghani & Tirmizi, 1995: 144–147, fig 1a–h (material from Karachi).— Apel, 2001: 56; Ng <i>et al</i>. 2008: 92 (in list); Galil 2009: 281, tab 1; Naderloo & Türkay 2012: 32; Naderloo 2017: 109, figs 14.35c, 14.37, 14.38.</p> <p> <i>Philyra sexangula —</i> Stephensen, 1946: 89.</p> <p> <i>Ebalia sagittifera —</i> Cooper, 1997: 173, 174 (partly), fig 7.</p> <p> <b>Material examined.</b> ZUTC 6925, 1 male (CL 8.4 mm, CW 7.6 mm), 2 females (CL 9.3 mm, CW 8.2 mm; CL 9.4 mm, CW 8.4 mm), Hormoz Island, Persian Gulf, unknown collector and date; ZUTC 1341, 1 male, 1 female, coast of Bushehr, Persian Gulf, 28°58′N, 50°49′E, sandy/rocky, 10.2006, coll. R. Naderloo; ZUTC 1342, 2 males, 1 female, Qeshm I., Persian Gulf, coll. M. Asgari; ZUTC 1343, 1 male, 1 female, Badnar Kolahi, Strait of Hormoz, 27°02′N, 56°51′E, muddy-sand flat, 22.04.2008, coll. R. Naderloo; ZUTC 1344, 1 juvenile, East of city, Bandar-Abbas, Persian Gulf, 27°11′N, 56°21′E, muddy-sand flat with shells, 23.04.2008, coll. R. Naderloo, A. Kazemi, A. Keykhosravi; ZUTC 1345, 1 male, Jofreh, Bushehr, Persian Gulf, 28°58′N, 50°49′E, sandy/rocky, dead coral with algae, 24.05.2008, coll. R. Naderloo, A. Kazemi, H. Salehi.</p> <p> <b>Description.</b> Carapace hexagonal (Fig. 1E), slightly longer than broad. Dorsal surface smooth except three narrow minutely granular ridges uniting to form "broad-arrow" pointing forwards, middle ridge extendingfrom progastric to intestinal region; lateral ridges extending backwards laterally to branchial region, running parallel to anterolateral margins, with ends projecting beyond posterolateral margins, forming larger denticles (Fig. 1E); regions relatively distinct, with elevated gastric, cardiac, branchial, intestinal regions; hepatic region excavated forming depression, upper and lower margins beaded, originating from middle of anterolateral margin, not merging anteriorly, broadly triangular tooth projecting on anterior half of lower margin of anterolateral border; anterolateral margin convex, shorter than posterolateral margin, merging with posterolateral margin to form broad triangular tooth; anterolateral, posterolateral, posterior margins beaded; epibranchial angle obtuse; posterolateral margin slightly sinuous; front smooth, almost straight, epistome visible beyond frontal margin from dorsal view; posterior margin almost straight, slightly convex, lateral sides with strong, pointed, outwardly directed spines, spines or small obtuse projections (Fig. 1E). Anterior margin of endostome reaching slightly beyond anterior margin of inhalent channels.</p> <p>Maxilliped 3 (Fig. 3C) smooth, entirely covering endostome; merus with notch, two-thirds as long as ischium along inner margin; ischium two times longer than wide; carpus not visible in external view when reposed; propodus and dactylus visible in external view, articulating subdistally on inner surface of merus; exopod (Fig. 3C) outer margin convex, setose, much longer than wide, almost twice the length of merus.</p> <p>Chelipeds (Fig. 1E, F) equal, as long as carapace length, granulated. Merus triquetral in cross-section with edges raised and granular; both inner and outer margins with tuberculated ridge. Carpus and propodus have raised row of granules along inner edge of their upper surface. Fingers slender, about two-thirds length of propodus, cutting edge of fingers toothed with scattered setae, median shallow canal extending to distal length of both fingers.</p> <p>P2–P5 (Fig. 1E) subcylindrical; total length of all pairs almost similar, merus and carpus glabrous, merus longest as compared to carpus, propodus and dactylus. Carpus and propodus almost equal in length, dactylus large with tapering distal end.</p> <p>Thoracic sternum (Fig. 1F) smooth, tuberculated on margins, slightly concave. Sternites 1–3 completely fused without any trace of sutures, sternite 3 separated from sternite 4 by shallow groove; sternite 4–6 almost similar in width, sternite 7 slightly tuberculated.</p> <p>Male pleon (Fig. 1F, 3D) smooth with three articulating parts: somite 1 free, narrow; somite 2–6 fused, immovable, posterolateral angles with small bulge, somite 6 without any denticle; telson triangular, longer than broad with curved apex.</p> <p>Female pleon ovate; somite 1 free; somites 2–6 fused, suture clearly visible between somites 2 and 3, partial suture visible between somites 3–4 and 5–6, forming domed plate almost completely covering thoracic sternum. Telson triangular, longer than broad, with curved apex (Fig. 2D).</p> <p>G1 (Fig. 4E, F) shaft long, slender, straight, apical process long, about 0.2 times as long as whole length, more sinuous-shape, with spade-shape (spatulate) ending, apical lobe bearing setae almost length of the tip. Female gonopore (Fig. 5D) on inner anterior edge of sternite 5, oval in shape with broad opening.</p> <p> <b>Variation</b>. The carapace of female resembles with that of male, except for lateral sides of posterior margin having sharp dorsoventrally flattened teeth (Fig. 2C).</p> <p> <b>Distribution.</b> Pakistan (Ghani & Tirmizi 1995), Persian Gulf [Stephensen (1946) as <i>Philyra sexangula</i>; Apel 2001; Naderloo & Türkay 2012; Naderloo 2017] and Gulf of Oman (Naderloo <i>et al</i>. 2015).</p> <p> <b>Remarks.</b> Ghani & Tirmizi (1995) described <i>T. concinnus</i> <b>n. comb.</b> on the basis of specimens collected from Karachi (Pakistan) and Persian Gulf. As mentioned earlier, the Persian Gulf material examined by these authors is referable to <i>T. sagittifera</i> <b>n. comb.</b> (Apel 2001; Naderloo & Türkay 2012; Naderloo 2017). Here we also confirm that the drawing of a Persian Gulf specimen by Ghani & Tirmizi (1995: fig. 2) agrees with type specimen of <i>P. sagittifera</i> in the following features: carapace hexagonal, smooth except three broad tuberculated ridges unite to form a "broad-arrow" point; epibranchial angle forming right angle, posterior margin convex, lateral sides with knob-like teeth having rounded tips, small median tooth present on the posterior margin in males; and G1 shaft straight, slender, with apical process slightly sinuous-shape, with tapering end.</p> <p> The holotype and some of the paratypes of <i>T. concinnus</i> <b>n. comb.</b> deposited in the Marine Reference Collection and Resource Centre, University of Karachi, Karachi, Pakistan are not traceable despite many searches in the museum (Noor Saher, personal communication). The second author has examined the paratype specimens (1 male and 1 female) deposited in Naturalis Biodiversity Center, Leiden, but these are in very poor condition and of little use for identification. The fresh specimens from the Persian Gulf examined here are in agreement with the description and illustrations of holotype provided by Ghani & Tirmizi (1995).</p> <p> <i>Tirmilyra concinnus</i> <b>n. comb.</b> closely resembles <i>T. sagittifera</i> <b>n. comb.</b> but can be differentiated from the latter species on the basis of several morphological characteristics that are discussed above in the remarks section of the latter species.</p>Published as part of <i>Patel, Krupal, Naderloo, Reza, Trivedi, Jigneshkumar & Mitra, Santanu, 2023, On the taxonomy of Philyra sagittifera (Alcock, 1896) and P. concinnus Ghani & Tirmizi, 1995 (Decapoda, Brachyura, Leucosiidae), with description of a new genus from the Indian Ocean, pp. 430-440 in Zootaxa 5330 (3)</i> on pages 436-439, DOI: 10.11646/zootaxa.5330.3.6, <a href="http://zenodo.org/record/8254906">http://zenodo.org/record/8254906</a>
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