Articles de revues : « P-type chromophores »

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Fave, Claire, Muriel Hissler, Tamás Kárpáti, Joëlle Rault-Berthelot, Valérie Deborde, Loic Toupet, László Nyulászi et Régis Réau. « Connecting π-Chromophores by σ-P−P Bonds : New Type of Assemblies Exhibiting σ−π-Conjugation ». Journal of the American Chemical Society 126, n^o 19 (mai 2004) : 6058–63. http://dx.doi.org/10.1021/ja0317067.

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Scheer, Hugo, et Hartmut Kayser. « Conformational studies of biliproteins from the insects pieris brassicae and cerura vinula ». Zeitschrift für Naturforschung C 43, n^o 1-2 (1 février 1988) : 84–90. http://dx.doi.org/10.1515/znc-1988-1-217.

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Chromophore conformation and protein secondary structure of biliproteins from the butterfly, Pieris brassicae, and the moth, Cerura vinula, have been investigated by absorption, circular dichroism and fluorescence spectroscopy. The chromophore of the P. brassicae protein, biliverdin IXy, has probably a cyclic-helical structure similar to that of free bile pigments of the biliverdin type. Though achiral by structure the chromophore displays strong optical activity in the native protein-bound state, but becomes inactive after urea denaturation of the protein. A minor biliprotein from P. brassicae shows absorption, circular dichroism and fluorescence spectra identical to the main biliprotein. In the biliprotein from Cerura vinula the structure of the pigment is still unknown. It has a semi-open conformation intermediate between that of the Pieris proteins and that of the phycobiliprotein, C-phycocyanin, and it retains optical activity after urea denaturation. The band widths and the size of the Stokes shifts of the fluorescence spectra indicate a high degree of conformational flexibility of the chromophores in the two Pieris pigments, and a decreased flexibility in the one from Cerura. In the biliproteins from both insects the polypeptides are low in a-helix content compared to that of phycobiliproteins. From these and earlier data, insect and algal biliproteins seem to be related only distantly if at all, but there exist also considerable differences among insect biliproteins from different species

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Li, Yiting, C. Ed Whittle, Keith A. Walters, Kevin D. Ley et Kirk S. Schanze. « Photophysics of π-conjugated metalorganic oligomers ». Pure and Applied Chemistry 73, n^o 3 (1 janvier 2001) : 497–501. http://dx.doi.org/10.1351/pac200173030497.

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The optical absorption and photoluminescence properties of PPE-type p-conjugated oligomers that contain a 2,2-bipyridine-5,5¢-diyl metal coordinating unit have been examined. The spectra of the free oligomers are compared with those that contain Re(CO)3Cl and Ru(bpy)22+ chromophores chelated to the bpy-diyl unit.

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Matsumoto, Jin, Tsutomu Shiragami, Kazutaka Hirakawa et Masahide Yasuda. « Water-Solubilization of P(V) and Sb(V) Porphyrins and Their Photobiological Application ». International Journal of Photoenergy 2015 (2015) : 1–12. http://dx.doi.org/10.1155/2015/148964.

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Porphyrins have been widely utilized as biochemical and biological functional chromophores which can operate under visible-light irradiation. Water-soluble porphyrins have been used as the drug for photodynamic therapy (PDT) and photodynamic inactivation (PDI). Although usual water-solubilization of porphyrins has been achieved by an introduction of an ionic group such as ammonium, pyridinium, sulfonate, phosphonium, or carboxyl to porphyrin ring, we proposed the preparation of water-soluble P and Sb porphyrins by modification of axial ligands. Alkyl (type A), ethylenedioxy (type E), pyridinium (type P), and glucosyl groups (type G) were introduced to axial ligands of Sb and P porphyrins to achieve water-solubilization of Sb porphyrin and P porphyrins. Here, we review their water-soluble P and Sb porphyrins from the standpoints of preparation, bioaffinity, and photosensitized inactivation.

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Khalid, Muhammad, Muhammad Usman Khan, Iqra Shafiq, Riaz Hussain, Akbar Ali, Muhammad Imran, Ataualpa A. C. Braga, Muhammad Fayyaz ur Rehman et Muhammad Safwan Akram. « Structural modulation of π-conjugated linkers in D–π–A dyes based on triphenylamine dicyanovinylene framework to explore the NLO properties ». Royal Society Open Science 8, n^o 8 (août 2021) : 210570. http://dx.doi.org/10.1098/rsos.210570.

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A donor–π–acceptor type series of Triphenylamine–dicyanovinylene-based chromophores ( DPMN1–DPMN11 ) was designed theoretically by the structural tailoring of π-linkers of experimentally synthesized molecules DTTh and DTTz to exploit changes in the optical properties and their nonlinear optical materials (NLO) behaviour. Density functional theory (DFT) computations were employed to understand the electronic structures, absorption spectra, charge transfer phenomena and the influence of these structural modifications on NLO properties. Interestingly, all investigated chromophores exhibited lower band gap (2.22–2.60 eV) with broad absorption spectra in the visible region, reflecting the remarkable NLO response. Furthermore, natural bond orbital (NBO) findings revealed a strong push–pull mechanism in DPMN1–DPMN11 as donor and π-conjugates exhibited positive, while all acceptors showed negative values. Examination of electronic transitions from donor to acceptor moieties via π-conjugated linkers revealed greater linear (〈 α 〉 = 526.536–641.756 a.u.) and nonlinear ( β tot = 51 313.8–314 412.661 a.u.) response. It was noted that the chromophores containing imidazole in the second p-linker expressed greater hyperpolarizability when compared with the ones containing pyrrole. This study reveals that by controlling the type of π-spacers, interesting metal-free NLO materials can be designed, which can be valuable for the hi-tech NLO applications.

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Karamshuk, Svitlana, Stefano Caramori, Norberto Manfredi, Matteo Salamone, Riccardo Ruffo, Stefano Carli, Carlo Bignozzi et Alessandro Abbotto. « Molecular Level Factors Affecting the Efficiency of Organic Chromophores for p-Type Dye Sensitized Solar Cells ». Energies 9, n^o 1 (7 janvier 2016) : 33. http://dx.doi.org/10.3390/en9010033.

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Zheng, Qingdong, Sandesh K. Gupta, Guang S. He, Loon-Seng Tan et Paras N. Prasad. « Synthesis, Characterization, Two-Photon Absorption, and Optical Limiting Properties of Ladder-Type Oligo-p-phenylene-Cored Chromophores ». Advanced Functional Materials 18, n^o 18 (23 septembre 2008) : 2770–79. http://dx.doi.org/10.1002/adfm.200800419.

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Espinoza, Eli Misael, John Anthony Clark, Mimi Karen Billones, Gustavo Thalmer de Medeiros Silva, Cassio Pacheco da Silva, Frank Herbert Quina et Valentine Ivanov Vullev. « Photophysics and Electrochemistry of Biomimetic Pyranoflavyliums : What Can Bioinspiration from Red Wines Offer ». Photochem 2, n^o 1 (6 janvier 2022) : 9–31. http://dx.doi.org/10.3390/photochem2010003.

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Natural dyes and pigments offer incomparable diversity of structures and functionalities, making them an excellent source of inspiration for the design and development of synthetic chromophores with a myriad of emerging properties. Formed during maturation of red wines, pyranoanthocyanins are electron-deficient cationic pyranoflavylium dyes with broad absorption in the visible spectral region and pronounced chemical and photostability. Herein, we survey the optical and electrochemical properties of synthetic pyranoflavylium dyes functionalized with different electron-donating and electron-withdrawing groups, which vary their reduction potentials over a range of about 400 mV. Despite their highly electron-deficient cores, the exploration of pyranoflavyliums as photosensitizers has been limited to the “classical” n-type dye-sensitized solar cells (DSSCs) where they act as electron donors. In light of their electrochemical and spectroscopic properties, however, these biomimetic synthetic dyes should prove to be immensely beneficial as chromophores in p-type DSSCs, where their ability to act as photooxidants, along with their pronounced photostability, can benefit key advances in solar-energy science and engineering.

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Gasper, Raphael, Julia Schwach, Jana Hartmann, Andrea Holtkamp, Jessica Wiethaus, Natascha Riedel, Eckhard Hofmann et Nicole Frankenberg-Dinkel. « Distinct Features of Cyanophage-encoded T-type Phycobiliprotein Lyase ΦCpeT ». Journal of Biological Chemistry 292, n^o 8 (10 janvier 2017) : 3089–98. http://dx.doi.org/10.1074/jbc.m116.769703.

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Auxiliary metabolic genes (AMG) are commonly found in the genomes of phages that infect cyanobacteria and increase the fitness of the cyanophage. AMGs are often homologs of host genes, and also typically related to photosynthesis. For example, the ΦcpeT gene in the cyanophage P-HM1 encodes a putative phycobiliprotein lyase related to cyanobacterial T-type lyases, which facilitate attachment of linear tetrapyrrole chromophores to Cys-155 of phycobiliprotein β-subunits, suggesting that ΦCpeT may also help assemble light-harvesting phycobiliproteins during infection. To investigate this possibility, we structurally and biochemically characterized recombinant ΦCpeT. The solved crystal structure of ΦCpeT at 1.8-Å resolution revealed that the protein adopts a similar fold as the cyanobacterial T-type lyase CpcT from Nostoc sp. PCC7120 but overall is more compact and smaller. ΦCpeT specifically binds phycoerythrobilin (PEB) in vitro leading to a tight complex that can also be formed in Escherichia coli when it is co-expressed with genes encoding PEB biosynthesis (i.e. ho1 and pebS). The formed ΦCpeT·PEB complex was very stable as the chromophore was not lost during chromatography and displayed a strong red fluorescence with a fluorescence quantum yield of ΦF = 0.3. This complex was not directly able to transfer PEB to the host phycobiliprotein β-subunit. However, it could assist the host lyase CpeS in its function by providing a pool of readily available PEB, a feature that might be important for fast phycobiliprotein assembly during phage infection.

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Graziosi, G., C. Preti, G. Tosi et P. Zannini. « Osmium(III) Halide Complexes with para-and meta-Substituted Benzeneseleninato Ligands ». Australian Journal of Chemistry 38, n^o 11 (1985) : 1675. http://dx.doi.org/10.1071/ch9851675.

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New complexes of osmium(III) with para - and meta-substituted benzeneseleninic acids of the type XC6H4SeO2H (X = H, p- Cl , m- Cl , p-Br, m-Br, p-Me) are reported. The compounds, of the type Os(XC6H4SeO2)3, Os(XC6H4SeO2)2Y, Os(XC6H4SeO2)Y2 and Os2(XC6H4SeO2)3Y3 (Y = Cl , Br), have been studied through spectroscopic techniques ( i.r ., far- i.r .and electronic spectra), magnetic susceptibility measurements, thermogravimetric studies and conductivity measurements. The wavelengths of the principal electronic absorption peaks have been accounted for quantitatively in terms of the crystal-field theory; the nephelauxetic parameter is indicative of an appreciable metal- ligand covalency. It is worth noting that among the present complexes the highest q values are related to the Os(XC6H4SeO2)3 derivatives in which OsO6 chromophores are present; the Dq values decrease on passing to the 1 : 2, 1 : 1.5 and 1 : 1 metal/ ligand molar ratio complexes according to the presence of chlorine- and bromine-containing chromophores . The i.r . data point to a seleninato -O,O′ coordination for all the complexes; in particular, the presence of three SeO bands with the irreducible representation A2 + 2E in the i.r . spectra of the tris derivatives suggests an octahedral configuration with D3 symmetry. All the halo complexes are polymeric octahedral with bridging halide atoms. The magnetic moment values lie in the expected range for the trisbenzeneseleninato derivatives, and they decrease on passing to the halo complexes.

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Qin, Peng, Joanna Wiberg, Elizabeth A. Gibson, Mats Linder, Lin Li, Tore Brinck, Anders Hagfeldt, Bo Albinsson et Licheng Sun. « Synthesis and Mechanistic Studies of Organic Chromophores with Different Energy Levels for p-Type Dye-Sensitized Solar Cells ». Journal of Physical Chemistry C 114, n^o 10 (18 mars 2010) : 4738–48. http://dx.doi.org/10.1021/jp911091n.

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Qin, Peng, Mats Linder, Tore Brinck, Gerrit Boschloo, Anders Hagfeldt et Licheng Sun. « High Incident Photon-to-Current Conversion Efficiency of p-Type Dye-Sensitized Solar Cells Based on NiO and Organic Chromophores ». Advanced Materials 21, n^o 29 (7 août 2009) : 2993–96. http://dx.doi.org/10.1002/adma.200802461.

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Sillman, A. J., J. K. Carver et E. R. Loew. « The photoreceptors and visual pigments in the retina of a boid snake, the ball python (Python regius) ». Journal of Experimental Biology 202, n^o 14 (15 juillet 1999) : 1931–38. http://dx.doi.org/10.1242/jeb.202.14.1931.

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The photoreceptors and visual pigments of Python regius were studied using microspectrophotometry and scanning electron microscopy. The retina contains rods and cones, with rods constituting at least 90 % of the photoreceptor population. The rods are of a single type with long, narrow outer segments and are tightly packed. The wavelength of maximum absorbance (λ max) of the visual pigment in the rods is in the region of 494 nm. Two distinct types of cone are present. The most common cone, with a stout but stubby outer segment, contains a visual pigment with λ max at approximately 551 nm. A relatively rare cone, with a long, slender outer segment, contains an ultraviolet-sensitive visual pigment with λ max at approximately 360 nm. All the visual pigments have chromophores based on vitamin A1. The results are discussed in relation to the behavior of P. regius.

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Sakuda, Eri. « (Invited) Synthesis and Photophysical Properties of Platinum(II) Complexes Having Electron Donor/Acceptor Moieties ». ECS Meeting Abstracts MA2022-01, n^o 13 (7 juillet 2022) : 886. http://dx.doi.org/10.1149/ma2022-0113886mtgabs.

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Boron containing π-electron chromophores represented by tri(9-anthryl)borane show quite unique spectroscopic and photophysical properties, owing to the presence of the vacant p-orbital on the boron atom. In practice, we demonstrated that the excited states of arylborane derivatives were characterized by charge transfer from the π-orbital of the aryl group to the vacant p-orbital on the boron atom: π(Ar) – p(B) CT. If such π(Ar) – p(B) CT interactions are introduced to the MLCT excited state of a transition metal complex, new and novel aspects into photophysics of the metal complexes could be demonstrated. We have previously reported our experiments on the platinum(II) complexes having arylborane-appended 2,2’:6’,2”-terpyridine (tpy) ligands to demonstrate synergetic metal(M) – ligand and π(Ar) – p(B) CT interactions. In the present study, we focus on donor-acceptor interaction using an arylborane substituent and discussed about the charge separation on the spectroscopic and photophysical properties of their metal complexes. Then, we synthesized a novel cyclometalated-type platinum (II) complex using an NCN tridentate ligand with boron substituents, which is thought to cause intermolecular interactions, and investigated its spectroscopic properties. Figure 1

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Kisel, Kristina S., Vadim A. Baigildin, Anastasia I. Solomatina, Alexey I. Gostev, Eugene V. Sivtsov, Julia R. Shakirova et Sergey P. Tunik. « Rhenium(I) Block Copolymers Based on Polyvinylpyrrolidone : A Successful Strategy to Water-Solubility and Biocompatibility ». Molecules 28, n^o 1 (1 janvier 2023) : 348. http://dx.doi.org/10.3390/molecules28010348.

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A series of diphosphine Re(I) complexes Re1–Re4 have been designed via decoration of the archetypal core {Re(CO)2(N^N)} through the installations of the phosphines P0 and P1 bearing the terminal double bond, where N^N = 2,2′-bipyridine (N^N1), 4,4′-di-tert-butyl-2,2′-bipyridine (N^N2) or 2,9-dimethyl-1,10-phenanthroline (N^N3) and P0 = diphenylvinylphosphine, and P1 = 4-(diphenylphosphino)styrene. These complexes were copolymerized with the corresponding N-vinylpyrrolidone-based Macro-RAFT agents of different polymer chain lengths to give water-soluble copolymers of low-molecular p(VP-l-Re) and high-molecular p(VP-h-Re) block-copolymers containing rhenium complexes. Compounds Re1–Re4, as well as the copolymers p(VP-l-Re) and p(VP-h-Re), demonstrate phosphorescence from a 3MLCT excited state typical for this type of chromophores. The copolymers p(VP-l-Re#) and p(VP-h-Re#) display weak sensitivity to molecular oxygen in aqueous and buffered media, which becomes almost negligible in the model physiological media. In cell experiments with CHO-K1 cell line, p(VP-l-Re2) and p(VP-h-Re2) displayed significantly reduced toxicity compared to the initial Re2 complex and internalized into cells presumably by endocytic pathways, being eventually accumulated in endosomes. The sensitivity of the copolymers to oxygen examined in CHO-K1 cells via phosphorescence lifetime imaging microscopy (PLIM) proved to be inessential.

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Kavanagh, Maeve A., Joshua K. G. Karlsson, Jonathan D. Colburn, Laura M. C. Barter et Ian R. Gould. « A TDDFT investigation of the Photosystem II reaction center : Insights into the precursors to charge separation ». Proceedings of the National Academy of Sciences 117, n^o 33 (3 août 2020) : 19705–12. http://dx.doi.org/10.1073/pnas.1922158117.

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Photosystem II (PS II) captures solar energy and directs charge separation (CS) across the thylakoid membrane during photosynthesis. The highly oxidizing, charge-separated state generated within its reaction center (RC) drives water oxidation. Spectroscopic studies on PS II RCs are difficult to interpret due to large spectral congestion, necessitating modeling to elucidate key spectral features. Herein, we present results from time-dependent density functional theory (TDDFT) calculations on the largest PS II RC model reported to date. This model explicitly includes six RC chromophores and both the chlorin phytol chains and the amino acid residues <6 Å from the pigments’ porphyrin ring centers. Comparing our wild-type model results with calculations on mutant D1-His-198-Ala and D2-His-197-Ala RCs, our simulated absorption-difference spectra reproduce experimentally observed shifts in known chlorophyll absorption bands, demonstrating the predictive capabilities of this model. We find that inclusion of both nearby residues and phytol chains is necessary to reproduce this behavior. Our calculations provide a unique opportunity to observe the molecular orbitals that contribute to the excited states that are precursors to CS. Strikingly, we observe two high oscillator strength, low-lying states, in which molecular orbitals are delocalized over ChlD1and PheD1as well as one weaker oscillator strength state with molecular orbitals delocalized over the P chlorophylls. Both these configurations are a match for previously identified exciton–charge transfer states (ChlD1+PheD1−)* and (PD2+PD1−)*. Our results demonstrate the power of TDDFT as a tool, for studies of natural photosynthesis, or indeed future studies of artificial photosynthetic complexes.

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Geraghty, Paul B., Calvin Lee, Jegadesan Subbiah, Wallace W. H. Wong, James L. Banal, Mohammed A. Jameel, Trevor A. Smith et David J. Jones. « High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension ». Beilstein Journal of Organic Chemistry 12 (2 novembre 2016) : 2298–314. http://dx.doi.org/10.3762/bjoc.12.223.

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The synthesis of key 4-alkyl-substituted 5-(trimethylsilyl)thiophene-2-boronic acid pinacol esters 3 allowed a simplified alkylthiophene catenation process to access bis-, ter-, quater-, and quinquethiophene π-bridges for the synthesis of acceptor–π-bridge-donor– π-bridge-acceptor (A–π-D–π-A) electron donor molecules. Based on the known benzodithiophene-terthiophene-rhodanine (BTR) material, the BXR series of materials, BMR (X = M, monothiophene), BBR (X = B, bithiophene), known BTR (X = T, terthiophene), BQR (X = Q, quaterthiophene), and BPR (X = P(penta), quinquethiophene) were synthesised to examine the influence of chromophore extension on the device performance and stability for OPV applications. The BT x R (x = 4, butyl, and x = 8, octyl) series of materials were synthesised by varying the oligothiophene π-bridge alkyl substituent to examine structure–property relationships in OPV device performance. The devices assembled using electron donors with an extended chromophore (BQR and BPR) are shown to be more thermally stable than the BTR containing devices, with un-optimized efficiencies up to 9.0% PCE. BQR has been incorporated as a secondary donor in ternary blend devices with PTB7-Th resulting in high-performance OPV devices with up to 10.7% PCE.

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Qin, Peng, Hongjun Zhu, Tomas Edvinsson, Gerrit Boschloo, Anders Hagfeldt et Licheng Sun. « Design of an Organic Chromophore for P-Type Dye-Sensitized Solar Cells ». Journal of the American Chemical Society 130, n^o 27 (juillet 2008) : 8570–71. http://dx.doi.org/10.1021/ja8001474.

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Qin, Peng, Hongjun Zhu, Tomas Edvinsson, Gerrit Boschloo, Anders Hagfeldt et Licheng Sun. « Design of an Organic Chromophore for P-Type Dye-Sensitized Solar Cells ». Journal of the American Chemical Society 130, n^o 51 (24 décembre 2008) : 17629. http://dx.doi.org/10.1021/ja8087289.

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Jung, Seung Chai, Jeong Yeon Cho et Seung Hyup Kim. « Subtype differentiation of small renal cell carcinomas on three-phase MDCT : usefulness of the measurement of degree and heterogeneity of enhancement ». Acta Radiologica 53, n^o 1 (février 2012) : 112–18. http://dx.doi.org/10.1258/ar.2011.110221.

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Background Subtype differentiation of small renal cell carcinomas (RCCs) can provide more information to surgeons and patients and get more useful information about imaging features of small renal tumors. Purpose To evaluate the usefulness of the measurement of degree and heterogeneity of enhancement in subtype differentiation of small renal cell carcinomas (RCCs) by three-phase multidetector-row CT (MDCT). Material and Methods We reviewed 149 pathologically confirmed small (<4cm) RCCs in 143 patients: 114 (clear cell), 17 (chromophobe), and 18 papillary (8 papillary type 1 and 10 papillary type 2). Scans in pre-contrast, corticomedullary, and nephrographic phases were obtained. We assessed the mean and standard deviation of the Hounsfield units (HU) in a region of interest (ROI) for the degree of enhancement and the heterogeneity of enhancement, respectively. We compared the attenuation values, and the degree and heterogeneity of enhancement among the subtypes. Results The clear cell type showed the highest enhancement and heterogeneity of enhancement followed by chromophobe and papillary types. There was a significant difference in enhancement between the clear cell and papillary types in the corticomedullary phase ( P < 0.01), and between clear and non-clear cell types in the nephrographic phase ( P < 0.05). Heterogeneity of enhancement showed a significant difference between clear cell and non-clear cell types in the corticomedullary phase ( P < 0.05). Conclusion The measurement of degree and heterogeneity of enhancement on contrast-enhanced MDCT may be a simple and useful method to differentiate between the different types of small RCCs.

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Jung, Cheolsoo, Tetsuya Aoyama, Tatsuo Wada, Hiroyuki Sasabe, Mitsutoshi Jikei et Masa-Aki Kakimoto. « The Photorefractive Effect in Monolithic Structural Polyimides ». High Performance Polymers 12, n^o 1 (mars 2000) : 205–12. http://dx.doi.org/10.1088/0954-0083/12/1/317.

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We report here the photorefractive effect in monolithic structural polyimides containing the triphenylamino-( p-nitrophenyl)-ethylene group as a nonlinear optical (NLO) chromophore and hole transfer. Three types of polyimides were synthesized to control the loading ratio of the NLO chromophore; 50, 30 and 17 mol% for polyimides 1, 2 and 3 respectively. In the two-beam coupling experiment, asymmetric energy transfer was observed in the case of polyimides 1 and 2, providing evidence for a phaseshifted grating after corona-poling treatment, whereas the energy transfer of polyimide 3 was not observed. This result denotes that the NLO chromophore plays an important role in monolithic photorefractive materials, and a greater than 30 mol% concentration of NLO chromophore is required for creating sufficient space charge distribution.

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Zhang, Qian-Qian, Ke-Jian Jiang, Jin-Hua Huang, Chuan-Wu Zhao, Li-Peng Zhang, Xue-Ping Cui, Mei-Ju Su, Lian-Ming Yang, Yan-Lin Song et Xue-Qin Zhou. « A push–pull thienoquinoidal chromophore for highly efficient p-type dye-sensitized solar cells ». Journal of Materials Chemistry A 3, n^o 15 (2015) : 7695–98. http://dx.doi.org/10.1039/c5ta01348h.

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A push–pull thienoquinoidal dye (QT-1), was synthesized as a sensitizer in a p-DSC, giving a high short-circuit photocurrent density of 8.2 mA cm⁻². The result would pave new organic semiconductor sensitizers for use in p-DSCs and other organic optoelectronic devices.

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Sinopoli, Alessandro, Christopher J. Wood, Elizabeth A. Gibson et Paul I. P. Elliott. « New cyclometalated iridium(III) dye chromophore complexes for p-type dye-sensitised solar cells ». Dyes and Pigments 140 (mai 2017) : 269–77. http://dx.doi.org/10.1016/j.dyepig.2017.01.011.

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Summers, Gareth H., et Elizabeth A. Gibson. « Bay Annulated Indigo as a New Chromophore for p-type Dye-Sensitized Solar Cells ». ChemPhotoChem 2, n^o 6 (14 avril 2018) : 498–506. http://dx.doi.org/10.1002/cptc.201700153.

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Fang, Zhi, Bingping Yang, Chunli Hu et Jianggao Mao. « Hybridization-activated new deep ultraviolet transparent nonlinear optical material Ba11[Al(PO4)4](P2O7)(PO4)3 with balanced overall performance and parsimony-forbidden structure ». Journal of Materials Chemistry C 7, n^o 48 (2019) : 15162–65. http://dx.doi.org/10.1039/c9tc05648c.

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Hybridization-enabled approach of a new deep-ultraviolet transparent nonlinear-optical material Ba₁₁[Al(PO₄)₄](P₂O₇)(PO₄)₃ exhibiting balanced overall performance and featuring three types of chromophores.

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TAMER, ÖMER, DAVUT AVCI et YUSUF ATALAY. « SPECTROSCOPIC STUDY, NLO PROPERTIES AND HOMO–LUMO ANALYSIS ON DIFFERENT DONOR AND ACCEPTOR SUBSTITUENTS OF THIAZOLYLAZOPYRIMIDINE CHROMOPHORES ». Journal of Theoretical and Computational Chemistry 12, n^o 05 (août 2013) : 1350039. http://dx.doi.org/10.1142/s0219633613500399.

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The molecular geometry optimization, vibrational frequencies and gauge including atomic orbital (GIAO) 1H and 13C chemical shift values of thiazolylazopyrimidine chromophores have been investigated by using density functional theories (DFT/B3LYP, PBE1PBE and BHand-HLYP) and Hartree–Fock (HF) methods with 6–31++G(d,p) basis set. The computed IR and NMR spectra are used to determine the types of the experimental bands observed. Also, the vibrational frequencies are supported on the basis of the potential energy distribution (PED) analysis calculated by using PBE1PBE method. The UV-vis spectrum has been obtained by TD-DFT and TD-HF methods. Total static dipole moment (μ), the mean polarizability (〈α〉), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (〈β〉), highest occupied molecular orbital (HOMO), and lowest occupied molecular orbital (LUMO) energies of thiazolylazopyrimidine chromophores also have been investigated with quantum chemical calculations. Obtained nonlinear optical (NLO) parameters are compared with experimental ones. Additionally, the molecular hardness (η) and electronegativity (χ) parameters have been obtained by using the frontier molecular orbital energies. Obtained data from thiazolylazopyrimidine chromophores are important for associating the experimental and theoretical spectra with molecular structure and their properties.

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Zhu, Qingqiang, Qing Xu, Weiqiang Dou, Wenrong Zhu, Jingtao Wu, Wenxin Chen et Jing Ye. « Diffusion kurtosis imaging features of renal cell carcinoma : a preliminary study ». British Journal of Radiology 94, n^o 1122 (1 juin 2021) : 20201374. http://dx.doi.org/10.1259/bjr.20201374.

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Objective: To explore the feasibility of diffusion kurtosis imaging (DKI) in differentiating different types of renal cell carcinoma (RCC). Methods: 36 patients with clear cell RCC (CCRCC, low-grade,n = 20 and high-grade, n = 16), 19 with papillary RCC, 11 with chromophobe RCC, and 9 with collecting duct carcinoma (CDC) were examined with DKI technique. b values of 0, 500 and 1000 s/mm2 were adopted. The DKI parameters, i.e., mean diffusivity (MD), mean kurtosis (MK), kurtosis anisotropy (KA), radial kurtosis (RK) and signa-to-noise ration (SNR) of DKI images at different b values were used. Results: The mean SNRs of DKI images at b = 0, 500 and 1000 s/mm2 were 32.8, 14.2 and 9.18, respectively. For MD parameter, a significant higher value was shown in CCRCC than those of papillary RCC, chromophobe RCC and CDC (p < 0.05). In addition, both chromophobe RCC and CDC have larger MD values than papillary RCC (p < 0.05), however, there was no significant differences between chromophobe RCC and CDC (p > 0.05). For MK, KA and RK parameters, a significant higher value was shown in papillary RCC than those of CCRCC, chromophobe RCC and CDC (p < 0.05). Moreover, both chromophobe RCC and CDC have significantly larger values of MK, KA and RK than CCRCC (p < 0.05). Conclusion: Our preliminary study demonstrated significant differences in the DKI parameters between the subtypes of RCCs, given an adequate SNR of DKI images. Advances in knowledge: 1.The MD value is the best parameter to distinguish CCRCC from other RCCs. 2.The MK, KA and RK values are the best parameters to distinguish papillary RCC from other RCCs. 3.DKI is able to provide images with sufficient SNRs in kidney disease.

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Bjazevic, Jennifer, Jasmir G. Nayak, Premal Patel, Anil Kapoor, Simon Tanguay, Antonio Finelli, Ricardo A. Rendon et al. « The impact of renal cell carcinoma histopathological subtype on disease prognosis : A Canadian multi-institutional analysis. » Journal of Clinical Oncology 33, n^o 7_suppl (1 mars 2015) : 480. http://dx.doi.org/10.1200/jco.2015.33.7_suppl.480.

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480 Background: Renal cell carcinoma (RCC) is divided into several histopathological subtypes, each with significantly different clinical features. However, current data regarding the prognostic value of histological subtype is limited and conflicted. We examined the impact of RCC histology on disease prognosis in a large, multi-institutional Canadian analysis. Methods: The Canadian Kidney Cancer Information System (CKCis), a prospective database from 14 Canadian institutions, was utilized for the study. 1284 patients with non-metastatic RCC, who underwent surgical intervention with curative intent, were included in the study. Patients were stratified according to their primary histology and the Chi-squared test was used to determine associations between histopathology and clinical features. The impact of histology of disease-free survival (DFS) was determined with a multivariate analysis adjusted for age, gender, tumor size, tumor grade, and pathological stage. Results: Clear cell RCC was the most prevalent histological subtype found in 80.5% of patients. Histopathology was significantly associated with patient age, tumor grade, and pathological stage. Advanced stage disease (>T3) was associated with clear cell and papillary type II RCC (p<0.05). 90.7%, 86.7%, 78.5%, and 78.8% of patients with chromophobe, papillary type I, papillary type II, and clear cell RCC respectively, were free of disease after a median follow-up of 1.2 years. On multivariate analysis, histological subtype was a significant predictor of disease-free survival (DFS). When compared to clear cell histology, chromophobe RCC had a significantly higher DFS (HR=0.38, 95% CI 0.15-0.95, p<0.05), and papillary type I RCC had a trend towards a lower rate of disease progression (HR=0.31, 95% CI 0.08-1.28, p=0.05). Conclusions: This study demonstrates that histological subtype impacts disease progression. Histological subtype was independently associated with DFS in surgically treated RCC, specifically chromophobe RCC was shown to have the highest DFS. This may be used to help individualize patient treatment and follow-up based on primary tumor histology.

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Sung, Ji-Yong, Hee-Woong Lim, Je-Gun Joung et Woong-Yang Park. « Pan-Cancer Analysis of Alternative Lengthening of Telomere Activity ». Cancers 12, n^o 8 (7 août 2020) : 2207. http://dx.doi.org/10.3390/cancers12082207.

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Alternative lengthening of telomeres (ALT) is a telomerase-independent mechanism that extends telomeres in cancer cells. It influences tumorigenesis and patient survival. Despite the clinical significance of ALT in tumors, the manner in which ALT is activated and influences prognostic outcomes in distinct cancer types is unclear. In this work, we profiled distinct telomere maintenance mechanisms (TMMs) using 8953 transcriptomes of 31 different cancer types from The Cancer Genome Atlas (TCGA). Our results demonstrated that approximately 29% of cancer types display high ALT activity with low telomerase activity in the telomere-lengthening group. Among the distinct ALT mechanisms, homologous recombination was frequently observed in sarcoma, adrenocortical carcinoma, and kidney chromophobe. Five cancer types showed a significant difference in survival in the presence of high ALT activity. Sarcoma patients with elevated ALT had unfavorable risks (p < 0.038) coupled with a high expression of TOP2A, suggesting this as a potential drug target. On the contrary, glioblastoma patients had favorable risks (p < 0.02), and showed low levels of antigen-presenting cells. Together, our analyses highlight cancer type-dependent TMM activities and ALT-associated genes as potential therapeutic targets.

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Zamir, Ahmed, Farhan Akhtar, Samina Waqar et Aminah Hanif. « PAX8 EXPRESSION AND ITS ASSOCIATIONS IN PRIMARY RENAL CELL CARCINOMA : A CROSS SECTIONAL STUDY ». PAFMJ 71, n^o 2 (28 avril 2021) : 414–17. http://dx.doi.org/10.51253/pafmj.v71i2.3462.

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Objective: To determine the frequency of PAX8 expression in cases of primary renal cell carcinoma (RCC) and its association with patient demographics and tumor type. Study Design: Cross sectional study. Place and Duration of Study: Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, from Jun 2016 to Jun 2017. Methodology: After ethics approval, 57 cases were selected by non probability consecutive sampling. Inclusion criteria was diagnosis of primary renal cell carcinoma of all histological types, in both genders, among adults aged >18 years. Exclusion criteria were poorly fixed specimens and metastatic renal cell carcinoma. The main outcome measure was PAX8 frequency in renal cell carcinoma. The secondary outcome measure was correlation of PAX8 expression with age, gender, tumor type and grade. Data was entered and analyzed on Statistical Package for the Social Sciences. Results: Out of 57 cases, majority were males 37, (64.9%). The mean age was 55.35 ± 12.60 years. Clear cell carcinoma was the most frequent histopathologic variant in 47 (81%) cases followed by papillary carcinoma in 6 (10.2%), chromophobe cell carcinoma 2 (3.5%), sarcomatoid renal carcinoma 1 (1.75%) and mucinous tubular and spindle cell carcinoma 1 (1.75%). PAX8 expression was positive in 52 (91.2%). No significant difference was found in the frequency of PAX8 expression across age (p=0.321), gender (p=1.00) and tumor type (p=1.00). There was significant difference seen across tumor grade p=0.03. Conclusion: PAX8 is an important additional diagnostic marker for renal cell carcinoma. It can be recommended for inclusion in immunohistochemical panel for diagnosis..............

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Medina, Vanessa, Guadalupe Aparicio Gallego, Isabel Santamarina, Manuel Valladares Ayerbes et Luis M. Antón Aparicio. « Biomolecular characterization of formalin-fixed paraffin-embedded primary renal tumor specimens. » Journal of Clinical Oncology 30, n^o 5_suppl (10 février 2012) : 421. http://dx.doi.org/10.1200/jco.2012.30.5_suppl.421.

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421 Background: Renal cell carcinoma (RCC) is the most common type of kidney cancer. It is required a better understanding of signalling pathways involved in renal cells. Methods: We assessed using immunohistochemistry (IHC) and quantitative real-time PCR (qPCR) with SYBR Green the profile of predictive markers involved in the cascade of events leading to the formation and progression: invasiveness, angiogenesis and antiapoptotic mechanisms. 80 RCC tissues were detected by IHC. RNA of quality only was obtained in 72 (80% clear RCC, 10% papillary RCC and 10% chromophobe RCC) to carry out the study of gene expression through qPCR. A pool of normal kidney-derived RNA samples (N=5) was used as healthy control. GAPDH and YWHAZ were used as reference genes. GenEx software was used for qPCR data processing and analysis. Nonparametric tests (Pearson’s correlation coefficient test and Spearman’s rho test, Kruskal — Wallis and Mann — Whitney) were applied for statistical data analysis (SPSS 19). Results: p53 showed higher expression in those cases with Furhman grade I (p=0.036). Moreover p53 showed a positive association with VEGF, GLUT1, GLUT4, VEGFR-2 and VHL (r=0.241, sig. level 0.05; r=0.291, sig. level 0.01; r=0.456, sig. level 0.01; r=0.187, sig. level 0.097 and Spearman’s rho=0.269, sig. level 0.05 respectively). Hif1- α, Hif1- β, Notch1 and Notch3 were upregulated in chromophobe RCC (p=0.045, p=0.03, p=0.03 and p=0.02 respectively). Hif1- α and Notch3 were upregulated in clear RCC (p=0.034 and p=0.041 respectively). Spearman’s correlation coefficient showed a strong positive correlation between Nocth1-4 members and their receptors and Hif1-α and β genes. Highlight the correlation found between: Notch1 and Hif1-α (Spearman’s rho = 0.740, significance level 0.01) and Hif1-β and Jagged1 (Spearman’s rho = 0.752, significance level 0.01). Conclusions: The pathway involving the tumor suppressor gene p53 could regulate tumor angiogenesis. Co-expression of Notch receptors, their ligands and Hif-1 α and Hif1- β subunits may play a role in human RCC. Notch cascade may represent a novel and therapeutically accessible pathway in chromophobe and clear RCC. More detailed studies of these crossing pathways are in progress.

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Melnik, Milan, Ondrej Sprusansky, Clive Eduard Holloway et Peter Mikus. « Platinum organometallic compounds : classification and analysis of crystallographic and structural data. Monomeric Pt compounds with PtC2AB, PtA2BC and PtABCD compositions ». Reviews in Inorganic Chemistry 32, n^o 2-4 (1 décembre 2012) : 111–80. http://dx.doi.org/10.1515/revic-2012-0008.

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AbstractThis review covers almost 350 four-coordinated monomeric organoplatinum complexes with PtC2AB, PtA2BC and PtABCD compositions, and there is wide variability of chromophores. The most common ligands in addition to the C donor are PPh3 and chlorine. Platinum(II) is found only in a square-planar environment involving cis- as well as trans-configurations with a different degree of distortion, especially when bi- or terdentate ligands are present. The trans-effect decreases in the order of the atoms in which the effect dominates, H>C>P>Si>S. There are at least two types of isomerism, cis-trans and distortion. The data strongly suggest that distortion isomerism is, for platinum chemistry, more common than cis- and trans-isomerism.

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Abdolahi, Mitra, Mostafa Alam, Arash Ghaffarpasand, Farzad Nouri, Ashkan Badkoobeh, Mohsen Golkar, Kamyar Abassi et Peyman Torbati. « Assessment of the Expression of GLUT1 in Renal Cell Carcinoma and its Various Subtypes ». Open Access Macedonian Journal of Medical Sciences 10, B (7 novembre 2022) : 2581–85. http://dx.doi.org/10.3889/oamjms.2022.10904.

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BACKGROUND: Renal cell carcinoma is one of the most common tumors of the kidney. Glucose transporters, transport glucose, and increased expression of these transporters have been reported in various tumor types. Glucose transporter 1 (GLUT1), the best-known glucose transporter, has an important role at several stages in cancer progression. The overexpression of GLUT1 in the tumor cells indicates an increased proliferation and invasive behavior of the tumor. AIM: This study aims to investigate the expression of GLUT1 in renal cell carcinoma and its subtypes. METHODS: This study is a descriptive cross-sectional study that was performed on patients with renal cell carcinoma. Seventy reports of formalin fixed; paraffin-embedded blocks of renal cell carcinoma were selected from pathology archives. The samples included: clear cell type renal cell carcinoma, RCC clear cell type with sarcomatoid feature, papillary renal cell carcinoma, and chromophobe renal cell carcinoma. RESULTS: In this study, 50 male and 20 female samples (71.4% and 28.6%) with the mean age of 57.9 ± 13.1 years were studied. Forty-three samples (61.4%) were positive for GLUT1 and 27 (38.9%) were negative for it. For the GLUT1 expression being positive or negative between the two groups, was not significantly affected by the age, sex, and the grade of the tumor, </AQ17>while the difference between the two groups was statistically significant in terms of stage and type of tumor (p < 0/001, p = 0.039). CONCLUSION: Renal cell carcinoma of ccRCC type is associated with increased GLUT1 expression. Therefore, the GLUT1 immunohistochemistry marker can be a useful marker for diagnosis of RCC, specifically ccRCC type.

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Rubtsova, N. A., A. B. Golbitc, E. V. Kryaneva, D. O. Kabanov, B. Yа Alekseev et A. D. Kaprin. « The role of ct-perfusion for diagnostic of solid renal tumors ». Diagnostic radiology and radiotherapy 12, n^o 2 (18 octobre 2021) : 70–78. http://dx.doi.org/10.22328/2079-5343-2021-12-2-70-78.

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Introduction. Nowdays, CT and/or MRI do not have sufficient specificity for the differential diagnosis of benign renal masses (oncocytoma and angiomyolipoma with minimal fat) from malignant tumors, and therefore all patients undergo surgical treatment.Purpose and objectives. The aim of the study was to evaluate the diagnostic effectiveness of perfusion computed tomography (PCT) for the differential diagnosis of solid renal masses.Materials and methods. The data of 60 patients (61,28±8,46 years) with primary founded solid renal tumors, who underwent PCT at the preoperative stage, were analyzed. Four perfusion indicators, such as BV, BF, PS and MTT, for the renal masses and normal cortex were evaluated.Results. According to the results of the statistical analysis, the perfusion parameters BV, BF, PS of the renal cortex were significantly higher than in tumors of any histological type (p<0,05). A statistically significant difference was found between clear cell, chromophobe and papillary types of renal cell carcinoma in terms of BV and BF (p<0,05), between benign and malignant tumors — in MTT.Conclusions. PCT has great potential in the assessment of neoangiogenesis and differential diagnosis of solid renal masses.

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Mukhomedyarova, A. A., B. Ya Alekseev et A. S. Kalpinskiy. « Long-term treatment outcomes of patients with non-clear cell renal cell carcinoma ». Cancer Urology 17, n^o 3 (11 novembre 2021) : 39–46. http://dx.doi.org/10.17650/1726-9776-2021-17-3-39-46.

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Objective: to analyze factors affecting relapse-free and overall survival of patients with non-metastatic non-clear cell renal cell carcinoma (nccRCC) after surgical treatment.Materials and methods. This study included 279 (13.62 %) nccRCC patients from the database containing information on 2049 patients with localized and locally advanced renal cell carcinoma (RCC) without distant metastases who underwent surgical treatment in the Department of Urologic Oncology, P.A. Herzen Moscow Oncology Research Institute between 2002 and 2018. Gender ratio was 1.36:1 (161 men (57.7 %) and 118 women (42.3 %)). Median follow-up time was 34.5 months (range: 1-141 months). Patients had undergone either radical nephrectomy (n = 117; 41.9 %) or kidney resection (n = 160; 57.4 %) or radiofrequency thermal ablation (n = 2; 0.7 %). Standard (open) transperitoneal approach was used in 135 patients (48.4 %) patients, whereas 144 (51.6 %) patients were operated on via laparoscopic approach. Postoperative histological examination demonstrated that 110 participants (39.4 %) had chromophobe RCC, while 79 (28.3 %) and 63 (22.6 %) individuals had type 1 and type 2 papillary RCC, respectively. Twenty-seven patients were found to have rare or mixed variants of nccRCC (they were excluded from the analysis due to their relatively small number). Patients were diagnosed with the following stages of cancer: рТ1а (n = 129; 46.2 %), pT1b (n = 72; 25.8 %), рТ2а (n = 18; 6.5 %), pT2b (n = 8; 2.9 %), рТ3а (n = 31; 11.1 %), pT3b (n = 4; 1.4 %), рТ4 (n = 1; 0,4 %), and pN+ (n = 16; 5.7 %).Results and conclusion. 13 patients (4.7 %) were diagnosed progressive disease; 9 patients (3.2 %) died due to nccRCC progression. The highest relapse-free and overall survival rates were registered in the patients with type 1 papillary RCC and chromophobe RCC.Spearman's correlation analysis showed a significant correlation between the risk of disease progression and tumor size (R = 0.23; p <0.0001), pT stage (R = 0.24; p = 0.0001), vascular invasion (R = 0.36; p <0.0001), pN+ stage (R = 0.4; p <0.0001), surgical resection margin (R = 0.5; p <0.0001), histological variant (R = 0.14; p = 0.02), and Furman differentiation grade (R = 0.16; p = 0.02). The following factors were found to have an impact on relapse-free survival according to multivariate Cox regression: presence of necrosis (p = 0.04), pT stage (p = 0.03), and vascular invasion (p = 0.08), although the last variable failed to reach statistical significance. Cancer-specific survival was significantly affected by pT stage (p = 0.01) and Furman differentiation grade (p = 0.04). None of the factors demonstrated significant associations with overall survival. Thus, the most significant prognostic factor affecting relapse-free, overall, and cancer-specific survival in nccRCC patients was the pT stage (p <0.05).

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Lee, Ju-Han, Eun Mee Han, Zhen-Hua Lin, Zheng-Sheng Wu, Eung-Seok Lee et Young-Sik Kim. « Clinicopathologic Significance of Nuclear Grooves and Inclusions in Renal Cell Carcinoma : Image Database Construction and Quantitative Scoring ». Archives of Pathology & ; Laboratory Medicine 132, n^o 6 (1 juin 2008) : 940–46. http://dx.doi.org/10.5858/2008-132-940-csonga.

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Abstract Context.—Nuclear grooves and inclusions are major features of cancer. However, the nuclear irregularities in renal cell carcinoma (RCC) have not yet been well characterized. Objective.—To determine the clinicopathologic significance of nuclear grooves and inclusions in RCC. Design.—The frequencies or scores of nuclear grooves and inclusions were compared with the histologic subtype, nuclear grade, and TNM stage, as well as overall survival of RCC patients. For objective counting of nuclear irregularities, a relational image database was constructed and used for quantitative assessment. Results.—Nuclear grooves and inclusions were seen in 96% and 65% of 110 RCC cases, respectively. The intranuclear inclusions were found more frequently in chromophobe and papillary types than in clear cell carcinoma (P < .001). The nuclear scores, the sum of grooves or inclusions per 5000 tumor cells, were highly related to the histologic subtype (P < .001). Clear cell RCCs with high inclusion scores (2 or more) were correlated with poorer overall survival in comparison to clear cell carcinomas with low inclusion scores (P = .04). The groove scores were highly associated with Fuhrman grade (P = .003) but not with overall survival of clear cell RCC patients (P = .65). In multivariate analysis, higher inclusion scores and advanced tumor stages (III/IV) were correlated with worse outcomes of clear cell RCC. Conclusions.—Nuclear grooves and inclusions are histologic components of RCCs, especially chromophobe and papillary carcinomas. Furthermore, nuclear inclusions might be an independent prognostic factor for clear cell RCC.

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Bergbauer, Matthias, et Claudia Eggert. « Degradability of chlorine-free bleachery effluent lignins by two fungi : effects on lignin subunit type and on polymer molecular weight ». Canadian Journal of Microbiology 40, n^o 3 (1 mars 1994) : 192–97. http://dx.doi.org/10.1139/m94-032.

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A bleachery effluent from a sulfite process pulp mill, which was extracted with alkali and treated with oxygen and hydrogen peroxide (EOP), was treated with two fungi, Trametes versicolor and Stagonospora gigaspora. Trametes versicolor did not cause any depolymerization or degradation of effluent lignins but increased the amount of chromophores, whereas S. gigaspora depolymerized the EOP lignins and caused a substantial reduction in aromatic compounds. For both fungal treatments, CuO oxidation caused a decrease in the yield of the aldehydes within the vanillyl and p-hydroxy phenol families, which was faster than the rates of decrease in the yields of the corresponding acids and ketones. However, only S. gigaspora caused changes in the pattern of the 11 characteristic lignin phenols produced by CuO oxidation, reflecting a preferential metabolism of some phenolic precursors. This fungus decreased the yield of total vanillyl phenols (V), which contributed the bulk of the 11 lignin oxidation products, from 93% initially to 59%. As a consequence, coumaryl (C), syringyl (S), and p-hydroxy phenols (P) became relatively enriched to 1.2, 6.5, and 33%, respectively. The stability of EOP-lignin constituent subunits is S > P > C > V. The two fungi differed significantly in their level of enzyme activities. In effluent-free medium, the ratio of laccase to peroxidase was higher for T. versicolor than for S. gigaspora. The presence of EOP-lignins significantly increased this ratio. No lignin peroxidase was detected but manganese peroxidase and laccase were detected during degradation activities.Key words: lignin phenols, CuO oxidation, laccase, manganese peroxidase, Trametes versicolor, Stagonospora gigaspora

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Droghetti, Federico, Elisabetta Benazzi, Rita Boaretto et Mirco Natali. « Evaluation of Pt Deposition onto Dye-Sensitized NiO Photocathodes for Light-Driven Hydrogen Production ». Applied Sciences 12, n^o 10 (13 mai 2022) : 4955. http://dx.doi.org/10.3390/app12104955.

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The design of photocathodes for the hydrogen evolution reaction (HER), which suitably couple dye-sensitized p-type semiconductors and a hydrogen evolving catalyst (HEC), currently represents an important target in the quest for artificial photosynthesis. In the present manuscript, we report on a systematic evaluation of simple methods for the deposition of Pt metal onto dye-sensitized NiO electrodes. The standard P1 dye was taken as the chromophore of choice and two different NiO substrates were considered. Both potentiostatic and potentiodynamic procedures were evaluated either with or without the inclusion of an additional light bias. Photoelectrochemical characterization of the resulting electrodes in an aqueous solution at pH 4 showed that all the methods tested are effective to attain photocathodes for hydrogen production. The best performances (maximum photocurrent densities of −40 µA·cm−2, IPCE of 0.18%, and ~60% Faradaic yield) were achieved using appreciably fast, light-assisted deposition routes, which are associated with the growth of small Pt islands homogenously distributed on the sensitized NiO.

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Gullian-Klanian, Mariel, Gerardo Gold-Bouchot et María José Sánchez-Solís. « Characteristics of Chromophoric Dissolved Organic Matter (CDOM) Produced by Heterotrophic Bacteria Isolated from Aquaculture Systems ». Journal of Marine Science and Engineering 10, n^o 5 (14 mai 2022) : 672. http://dx.doi.org/10.3390/jmse10050672.

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Heterotrophic bacteria (HB) play an important role in aquatic ecosystems as recyclers of dissolved organic matter (DOM). The objective of this study was to characterize the spectral characteristics of intracellular (IC), and extracellular (EC) compounds produced by 12 HB isolated from two aquaculture systems. Microorganisms belonging to the genera Bacillus, Paenibacillus, and Psychrobacillus were identified by analysis of the 16S ribosomal gene. Aliquots of bacterial culture were centrifugated every hour (1st to 7th) to obtain the EC compounds. The pellet was ultrasound-lysed to obtain the IC compounds. Excitation-emission matrices were used in combination with parallel factor analysis (PARAFAC) to characterize the fluorescent components of DOM (FDOM). PARAFAC indicated two protein-like components and two humic-like components in both cell spaces. At the IC, B. macquariensis showed a high fluorescence index (FI), probably associated with fulvic acid, quinones, or ketones. Psychrobacillus insolitus showed an inverse correlation between spectral slopes S275–295 and S350–400 in the EC and IC fractions, which may indicate differential release of low and high molecular weight molecules in these two fractions. The opposite occurred with B. licheniformis and P. alvei. The origin of FDOM in HB is an important finding of this work. The most significant amount of protein-like substances was produced at the IC level, with the humic- and fulvic-type at the EC. The main finding of this work is the evidence of differential production of humic-type or protein-type FDOM production by HB species from marine and freshwater aquaculture systems in their intracellular and extracellular fractions, as well different relative molecular weight. For aquaculture, these findings suggest that some bacterial species show promise in supplying essential amino acids to growing organisms, and others play a major role in nutrient exchange and the global carbon cycle.

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Grätzel, Michael. « Nanocrystalline Thin-Film PV Cells ». MRS Bulletin 18, n^o 10 (octobre 1993) : 61–66. http://dx.doi.org/10.1557/s0883769400038331.

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In a conventional p-n junction photovoltaic cell, made, for example, from silicon, the semiconductor assumes two roles at the same time: It harvests the incident sunlight and conducts the charge carriers produced under light excitation. In order to function at a good efficiency, the photons have to be absorbed close to the p-n interface. Electron-hole pairs produced away from the junction must diffuse to the p-n contact where the local electrostatic field separates the charges. To avoid charge carrier recombination during the diffusion, the concentration of defects in the solid must be small. This imposes severe requirements on the purity of the semiconductor material, rendering solid-state devices of the conventional type expensive.We have developed a new molecular photovoltaic system for solar light harvesting and conversion to electricity. It is based on the spectral sensitization of a thin ceramic membrane by suitable transition-metal complexes. The film consists of nanometersize colloidal titanium dioxide particles sintered together to allow for charge carrier transport. When derivatized with a suitable chromophore, these membranes yield extraordinary efficiencies for the conversion of incident photons into electric current, exceeding 90% for certain transition metal complexes within the wavelength range of their absorption band. In this article, we discuss the underlying physical principles of these astonishing findings. Exploiting this discovery, we have developed a new type of photovoltaic device whose overall light-to-electric-energy conversion yield is 12–15% in diffuse day-light and 10% under direct (AM1.5) solar irradiation.

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Pecoraro, Adriana, Pasqualino Maddalena, Michele Pavone et Ana B. Muñoz García. « First-Principles Study of Cu-Based Inorganic Hole Transport Materials for Solar Cell Applications ». Materials 15, n^o 16 (18 août 2022) : 5703. http://dx.doi.org/10.3390/ma15165703.

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Perovskite solar cells (PSCs) and dye-sensitized solar cells (DSCs) both represent promising strategies for the sustainable conversion of sunlight into electricity and fuels. However, a few flaws of current devices hinder the large-scale establishment of such technologies. On one hand, PSCs suffer from instabilities and undesired phenomena mostly linked to the perovskite/hole transport layer (HTL) interface. Most of the currently employed organic HTL (e.g., Spiro-OMeTAD) are supposed to contribute to the perovskite decomposition and to be responsible for charge recombination processes and polarization barriers. On the other hand, power conversion efficiencies (PCEs) of DSCs are still too low to compete with other conversion technologies. Tandem cells are built by assembling p-type and n-type DSCs in a cascade architecture and, since each dye absorbs on a different portion of the solar spectrum, the harvesting window is increased and the theoretical efficiency limit for a single chromophore (i.e., the Shockley–Queisser limit) is overcome. However, such a strategy is hindered by the lack of a p-type semiconductor with optimal photocathode features. Nickel oxide has been, by far, the first-choice inorganic p-type semiconductor for both PV technologies, but its toxicity and non-optimal features (e.g., too low open circuit voltage and the presence of trap states) call for alternatives. Herein, we study of three p-type semiconductors as possible alternative to NiO, namely CuI, CuSCN and Cu2O. To this aim, we compare the structural and electronic features of the three materials by means of a unified theoretical approach based on the state-of-the art density functional theory (DFT). We focus on the calculation of their valence band edge energies and compare such values with those of two widely employed photo-absorbers, i.e., methylammonium lead iodide (MAPI) and the triple cation MAFACsPbBrI in PSCs and P1 and Y123 dyes in DSCs, given that the band alignment and the energy offset are crucial for the charge transport at the interfaces and have direct implications on the final efficiency. We dissect the effect a copper vacancy (i.e., intrinsic p-type doping) on the alignment pattern and rationalize it from both a structural and an electronic perspective. Our data show how defects can represent a crucial degree of freedom to control the driving force for hole injection in these devices.

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Zheng, Jing, Toyoshi Inoguchi, Shuji Sasaki, Yasutaka Maeda, Mark F. McCarty, Masakazu Fujii, Noriko Ikeda, Kunihisa Kobayashi, Noriyuki Sonoda et Ryoichi Takayanagi. « Phycocyanin and phycocyanobilin fromSpirulina platensisprotect against diabetic nephropathy by inhibiting oxidative stress ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 304, n^o 2 (15 janvier 2013) : R110—R120. http://dx.doi.org/10.1152/ajpregu.00648.2011.

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We and other investigators have reported that bilirubin and its precursor biliverdin may have beneficial effects on diabetic vascular complications, including nephropathy, via its antioxidant effects. Here, we investigated whether phycocyanin derived from Spirulina platensis, a blue-green algae, and its chromophore phycocyanobilin, which has a chemical structure similar to that of biliverdin, protect against oxidative stress and renal dysfunction in db/db mice, a rodent model for Type 2 diabetes. Oral administration of phycocyanin (300 mg/kg) for 10 wk protected against albuminuria and renal mesangial expansion in db/db mice, and normalized tumor growth factor-β and fibronectin expression. Phycocyanin also normalized urinary and renal oxidative stress markers and the expression of NAD(P)H oxidase components. Similar antioxidant effects were observed following oral administration of phycocyanobilin (15 mg/kg) for 2 wk. Phycocyanobilin, bilirubin, and biliverdin also inhibited NADPH dependent superoxide production in cultured renal mesangial cells. In conclusion, oral administration of phycocyanin and phycocyanobilin may offer a novel and feasible therapeutic approach for preventing diabetic nephropathy.

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Ohta, Kaoru, Mitsuharu Suzuki, Hiroko Yamada et Keisuke Tominaga. « (Invited) Probing Charge Carrier Dynamics in Porphyrin-Based Bulk Heterojunction Thin Films with Time-Resolved Terahertz Spectroscopy ». ECS Meeting Abstracts MA2022-01, n^o 13 (7 juillet 2022) : 909. http://dx.doi.org/10.1149/ma2022-0113909mtgabs.

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Organic photovoltaic (OPV) solar cells have attracted much attention in recent years because of the low production cost and ease of device fabrication. However, the power conversion efficiency is still low compared to the silicon and perovskite solar cells so that further research is necessary to improve their performance. In particular, understanding of the detailed mechanisms of charge carrier generation, recombination and carrier transport process is very important for developing design principles of new compounds for OPVs. Until now, polymer-based compounds have been widely used for p-type semiconductors. However, it is not easy to obtain information on how the microscopic structure of bulk heterojunction (BHJ) blend of donor and acceptor materials affect the charge carrier dynamics because one cannot easily control the molecular weight and conformational distributions of polymer compounds. On the other hand, small molecule-based semiconductors have several unique advantages such well-defined chemical structures, ease of purification and small batch-to-batch variations. Tetrabenzoporphyrin (BP) has been frequently used as a small-molecule organic semiconductor. Recently, Yamada and coworkers synthesized diketopyrrolopyrrole-linked tetrabenzoporphyrin (DPP-BP) conjugates that have linear alkyl groups on the DPP moieties whose chain length is defined as n, namely, Cn-DPP-BP (n=4, 6, 8, or 10). For DPP-BP based solar cells, they demonstrated that alkyl chain length affects the power conversion efficiency. Therefore, it is very interesting to see how the local BHJ structures of DPP-BP based thin films affect the initial step of the charge carrier dynamics because such studies are difficult to perform for polymer-based systems. We can take advantage of small molecule-based systems to study the relationship between the local structure and the charge carrier dynamics. In this work, we used time-resolved terahertz (THz) spectroscopy to investigate the charge carrier dynamics of DPP-BP BHJ thin films blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM). Time-resolved THz spectroscopy is a unique method to quantify charge carrier mobility with very fast time resolution (less than picosecond). This spectroscopy reflects the charge carrier dynamics in the local spatial region because of the high-frequency nature of the THz electric field. We chose C4-DPP-BP:PC61BM and C10-DPP-BP:PC61BM thin films for the THz measurements. In the previous study, it was found that C4-DPP-BP molecule prefers to take a face-on geometry on the substrate. A grain size of the aggregates was around 100 nm or smaller which were measured by atomic force microscopy. In such a structure, one can expect that charge transport takes place very efficiently to the electrode. Actually, power conversion efficiency is 5.2 % which is highest among a series of DPP-BP chromophores. On the other hand, C10-DPP-BP adopts an edge-on geometry on the substrate and forms micrometer-sized aggregates. In this structure, molecular stacking is oriented perpendicular to the electrode so that power conversion efficiency decreases to 0.19%. In contrast to the other measurements, the THz spectroscopy has sensitivity to in-plane motion of the charge carriers with respect to the substrate, we expect to observe higher in-plane mobility of the charge carriers in the C10-DPP-BP:PC61BM BHJ films compared to C4-DPP-BP based films. In contrast to our intuitive expectation, we found that the product of the carrier mobility and the yield of the photo-generated charge carriers is similar to each other. We consider that the similarity of the charge carrier dynamics results from the high-frequency nature of the local mobility of the polarons because most of the polarons are confined in less than a 10-nm length scale. Furthermore, the lowest limit of the carrier mobility obtained from our results is about 1.0 cm2V-1s-1 when the quantum yield of the charge carrier generation is assumed to be unity. This value is much higher than those obtained by space-charge-limited current method. We expect that charge separation occurs very efficiently when the local mobility of the charge carrier is high. In this contribution, we will present importance of the local mobility of the charge carriers and difference of charge transport between short and long length scales in DPP-BP based solar cells.

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Grånäs, Oscar, Grigory Kolesov et Efthimios Kaxiras. « Impact of Vibrations and Electronic Coherence on Electron Transfer in Flat Molecular Wires ». MRS Advances 2, n^o 14 (2017) : 811–16. http://dx.doi.org/10.1557/adv.2017.157.

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ABSTRACTElectron transfer in molecular wires are of fundamental importance for a range of optoelectronic applications. The impact of electronic coherence and ionic vibrations on transmittance are of great importance to determine the mechanisms, and subsequently the type of wires that are most promising for applications. In this work, we use the real-time formulation of time-dependent density functional theory to study electron transfer through oligo-p-phenylenevinylene (OPV) and the recently synthesized carbon bridged counterpart (COPV). A system prototypical of organic photovoltaics is setup by bridging a porphyrin-fullerene dyad, allowing a photo-excited electron to flow between the Zn-porphyrin (ZnP) chromophore and the C60 electron acceptor through the molecular wire. The excited state is described using the fully self-consistent ∆-SCF method. The state is then propagated in time using the real-time TD-DFT scheme, while describing ionic vibrations with classical nuclei. The charge transferred between porphyrin and C60 is calculated and correlated with the velocity autocorrelation functions of the ions. This provides a microscopic insight to vibrational and tunneling contributions to electron transport in linked porphyrin-fullerene dyads. We elaborate on important details in describing the excited state and trajectory sampling.

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Sen, Shiraj, Jason Roszik, Funda Meric-Bernstam et Vivek Subbiah. « Hormone receptor (AR/ER/PR) expression as a prognostic marker and novel candidate for drug development across multiple tumor types. » Journal of Clinical Oncology 35, n^o 15_suppl (20 mai 2017) : 2537. http://dx.doi.org/10.1200/jco.2017.35.15_suppl.2537.

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2537 Background: Hormone receptor (HR) [androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR)] expression is ubiquitous across tumor types and central to breast and prostate cancer treatment. While implicated in tumorigenesis, its role as a prognostic biomarker and therapeutic target in other tumor types has yet to be elucidated. Methods: We performed bioinformatic analyses of HR expression [reported as median transcripts per million (TPM)] using RNAseq from the Cancer Genome Atlas and completed Kaplan-Meier analyses to identify associations between HR expression and median overall survival (OS). Results: 9,743 samples from 9,674 patients across 33 tumor types were analyzed. AR was highly expressed in GBM (2 TPM), low grade glioma (2 TPM), breast (15 TPM), prostate (14 TPM), ovarian (6 TPM), renal clear cell carcinoma (4 TPM) and HCC (2 TPM) . Tumors with the highest quartile of expression had improved OS in renal clear cell [53 months (mo) vs not reached (NR), p = 4x10-11] and adrenocortical carcinoma (45 mo vs NR, p = .03) and worse OS in low grade glioma (119 vs 64 mo, p = 6x10-4). PR was highly expressed in uterine (12 TPM), breast (5 TPM), and renal chromophobe (2 TPM) carcinoma. PR expression was associated with improved OS in sarcoma (49 mo vs NR, p = .03), endometrial (NR, p = .02) and renal clear cell carcinoma (58 mo vs NR, p = .003) and worse OS in low grade glioma (53 vs 97 mo, p = .01), gastric adenocarcinoma (7 vs 17 mo, p = .04), and possibly pancreatic adenocarcinoma (21 vs 44 mo, p = .07). ER was highly expressed in breast (116 TPM), endometrial (87 TPM), ovarian (32 TPM), cervical (4 TPM), thyroid (4 TPM), prostate (3 TPM), and lung adenocarcinoma (2 TPM). ER expression was associated with improved OS in mesothelioma (15 vs 28 mo, p = .03) and endometrial cancer (NR, p = .001) and worse OS in squamous lung cancer (80 vs 48 mo, p = .02). Conclusions: HR expression may represent a novel prognostic marker in multiple tumor types and a candidate for drug development in low grade glioma, gastric adenocarcinomas, squamous cell lung cancer, and pancreatic adenocarcinomas. Protein-based IHC testing and early phase clinical trials targeting HR signaling in these tumor types is warranted.

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Albiges, L., J. Couturier, Y. Allory, P. Camparo, M. Sibony, A. Vieillefond, B. T. Teh, B. J. Escudier et V. Molinie. « Parafibromin as a new immunohistochemistry staining to improve pathologic diagnosis of renal oncocytoma : Analysis of 225 renal tumors. » Journal of Clinical Oncology 29, n^o 7_suppl (1 mars 2011) : 408. http://dx.doi.org/10.1200/jco.2011.29.7_suppl.408.

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408 Background: Chromophobe renal cell carcinoma (chRCC) and renal oncocytoma (Onc) are two distinct but closely related entities with strong morphologic and genetic similarities. While chRCC is a malignant tumor, Onc is usually considered as a benign entity. Recently, gene expression profiling applied on chRCC and Onc identified new potential markers that may effectively discriminate the 2 pathologic entities, including parafibromin. This work aims at evaluating the diagnostic value of Parafibromin (Pf) immuno staining on a large number of renal tumor samples. Methods: Sixty-three renal clear cell carcinoma (ccRCC), 47 papillary (Pap), 40 chRCC, and 75 Onc were immunostained for parafibromin antibody (1/200; Santacruz Biotechnology), on a tissue micro array. Results: Parafibromin was positive in 38.6% of Onc, vs 5% of chRCC (p < 0.001), with a 95% specificity, and the positive predictive value observed for parafibromin was 94%. For other tumor types, a positive staining for parafibromin was observed in 7.9% and 8.5% in ccRCC and Pap respectively. Conclusions: Parafibromin is a recently identified protein which seems to be specific for oncocytoma, and highly discriminant for other histologic renal cell tumor subtypes, especially for chromophobe. IHC may help to optimize therapeutics strategy for small renal mass and avoid surgical resection of benign lesions in some patients.Validation of this staining on renal tumor biopsies is on going.The value of the combination of this new immunostaining associated with the three standard IHC staining (CK7, CD117, E Cad) will be provided at the meeting. [Table: see text] No significant financial relationships to disclose.

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Mandic, Robert, Abbas Agaimy, Daniel Pinto-Quintero, Katrin Roth, Afshin Teymoortash, Hans Schwarzbach, Christine G. Stoehr, Fiona R. Rodepeter, Boris A. Stuck et Michael Bette. « Aberrant Expression of Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) in Warthin Tumors ». Cancers 12, n^o 5 (29 avril 2020) : 1112. http://dx.doi.org/10.3390/cancers12051112.

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The Warthin tumor represents the second most frequent benign tumor of the parotid gland and is characterized by the presence of oncocytes rich in structurally and functionally altered mitochondria. Next to its role in metabolism, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is also implicated in cellular mitophagy. Immunohistochemistry was carried out on Warthin tumor and normal control (parotid gland with striated ducts) tissues, using anti-GAPDH specific antibodies followed by digital image analysis. Laser capture microdissection was used to isolate the oncocytic tumor cell and normal control striated duct compartments for RNA extraction and qPCR. Warthin tumor oncocytes exhibited a markedly spotted GAPDH staining pattern exhibiting cells with cytoplasmic and nuclear, only nuclear or none GAPDH staining. A significantly lower (p < 0.0001) total GAPDH signal was detected in Warthin tumor oncocytes. Similarly, significantly lower (p < 0.005) GAPDH mRNA levels were seen in oncocytes compared with normal ductal cells. To exclude the possibility of this GAPDH staining pattern being a general feature of oncocytic neoplasms of different organs, we tested a cohort of renal oncocytoma and oncocytic chromophobe carcinoma; none showed this type of staining. The observed progressive GAPDH loss in Warthin tumor oncocytes could be implicated in the pathogenesis of Warthin tumors.

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Roy, Roopali, et Michael W. W. Adams. « Characterization of a Fourth Tungsten-Containing Enzyme from the Hyperthermophilic Archaeon Pyrococcus furiosus ». Journal of Bacteriology 184, n^o 24 (15 décembre 2002) : 6952–56. http://dx.doi.org/10.1128/jb.184.24.6952-6956.2002.

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ABSTRACT Pyrococcus furiosus grows optimally near 100°C using peptides and carbohydrates as carbon sources, and it reduces elemental sulfur (S0), if present, to H2S. Tungsten (W), an element rarely used in biology, is required for optimal growth, and three different tungsten-containing enzymes have been previously purified from this organism. They all oxidize aldehydes of various types and are thought to play primary roles in the catabolism of sugars or amino acids. Here, the purification of a fourth tungsten-containing enzyme, termed WOR 4, from cell extracts of P. furiosus grown with S0 is described. This was achieved by monitoring through multiple chromatography steps the W that is not associated with the three characterized tungstoenzymes. The N-terminal sequence of WOR 4 and the approximate molecular weight of its subunit determined electrophoretically (69,000) correspond to the product of an ORF (PF1961, wor4) present in the complete genome sequence of P. furiosus. WOR 4 is a homodimer and contains approximately one W, three Fe, three or four acid-labile sulfide, and one Ca atom per subunit. The visible and electron paramagnetic resonance spectra of the oxidized and reduced enzyme indicate the presence of an unusual iron-sulfur chromophore. WOR 4 does not oxidize aliphatic or aromatic aldehydes or hydroxy acids, nor does it reduce keto acids. Consistent with prior microarray data, the protein could not be purified from P. furiosus cells grown in the absence of S0, suggesting that it may have a role in S0 metabolism.

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Plantade, A., T. Choueiri, B. Escudier, B. Rini, S. Negrier, A. Ravaud, S. Oudard, P. Elson et R. Bukowski. « Treatment outcome for metastatic papillary and chromophobe renal cell carcinoma (RCC) patients treated with tyrosine-kinase inhibitors (TKIs) sunitinib and sorafenib ». Journal of Clinical Oncology 25, n^o 18_suppl (20 juin 2007) : 5037. http://dx.doi.org/10.1200/jco.2007.25.18_suppl.5037.

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5037 Background: Sunitinib (SUNI) and sorafenib (SORAF) are novel TKIs that have shown significant clinical activity in metastatic clear-cell RCC. Papillary (PAP) and chromophobe (CHRM) histologies represent the majority non-clear-cell RCC. The activity of SUNI and SORAF in non-clear cell histologies has not been evaluated. Methods: Clinical features at study entry and treatment outcomes were evaluated in all patients (pts) with metastatic PAP and CHRM RCC who received either SUNI or SORAF as their initial TKI treatment at one of five different cancer centers in France and USA between 2002 and 2006. Descriptive statistics were used to evaluate the collected data. Overall Response rate (ORR) was investigator-assessed per RECIST criteria. Fisher’s exact test was used for categorical variables and the Kaplan-Meier method was used to estimate survival (Overall Survival (OS) and progression-free survival (PFS)). Results: Median age for the 53 patients was 59 years and 64% were male. The number of patients with PAP and CHRM histologies were 41 (77%) and 12 (23%), respectively. Nephrectomy was performed in 87% of patients and 33/53 (62%) of pts were previously treated (26/33, 79%, with cytokines). ORR, PFS and OS for the entire cohort were 10%, 8.9 months (m) and 12.2 m, respectively. Twenty (38%) and 33 (62%) pts were treated with SUNI and SORAF, respectively. 3/12 (25%) of CHRM pts had an ORR vs. 2/41(4.8%) with PAP histology (P=0.07). PFS for CHRM pts was 9.3 m compared to 6.6 m for PAP pts (p=0.07). OS was not different across histologies and type of TKI received. SUNI treated pts had an ORR of 15% and PFS of 11.9 m compared to 6% (p=0.3) and 5.5 m for SORAF pts (p=0.002), respectively. Other factors found to be associated with shorter PFS include ECOG PS >0 (p=0.03) and hemoglobin< normal (p=0.02). Conclusions: TKI may have activity in metastatic CHRM RCC, similar to what is seen in clear-cell histology. Minimal activity however is noted in PAP RCC, justifying continued investigations of novel agents in this histology. No significant financial relationships to disclose.

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Antón Aparicio, Luis M., Vanessa Medina Villaamil, Guadalupe Aparicio Gallego, Isabel Santamarina Cainzos, Maria Quindós Varela et Manuel Valladares Ayerbes. « Molecular expression profiling and pathway analysis of formalin-fixed paraffin-embedded primary renal tumor specimens. » Journal of Clinical Oncology 31, n^o 6_suppl (20 février 2013) : 448. http://dx.doi.org/10.1200/jco.2013.31.6_suppl.448.

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448 Background: Many studies have demonstrated genetic and environmental factors lead to renal cell carcinoma (RCC) occurring during a protracted period of tumorigenesis. It seemed suitable identify and characterize potential molecular markers which might provide rapid and effective possibilities for early detection of RCC. The purpose from this analysis was to derive predictive models which could predict more accurately than any one factor alone. Methods: We assessed using quantitative real-time PCR (qPCR) with SYBR Green the profile of 32 predictive markers involved in the cascade of events leading to the formation and progression of this disease to evaluate their involvement in oncogenesis. RNA of quality was obtained in 90% of samples (N=80, 52/80 clear RCC, 6/80 papillary RCC and 14/80 chromophobe RCC) to carry out the study of gene expression. GenEx software was used for qPCR data processing and analysis. The potential correlation between mRNA expression and the pathological features of the study subjects was assessed by Pearson Chi-squared. Linear rather than logistic regression models were used (SPSS statistics 21.0 software). Additionally, a knowledgebases of biological pathways, Reactome and Snow (Babelomics), were used to superimpose our quantitative expression data. Results: The best gene predictors related to different pathological variables (histological type, tumor size, Fuhrman grade, number of involved nodes, renal pelvis invasion, lymphatic vessels invasion, and rupture of the renal capsule): Hif1-α (p < 0.001), Hif1-β (p = 0.035), DLL1 (p = 0 .012), DLL3 (p< 0.001), c-Kit (p = 0.002), PDGFR-β (p =0.002), PDGFR-α (p = 0.026), Bax-β (p = 0.005), Survivin (p = 0.028), Notch1 (p = 0.006), Notch2 (p = 0.007), Notch3 (p = 0.016), Notch4 (p = 0.005), EGFR (p = 0.029), Glut3 (p = 0.026), Glut5 (p = 0.036), FH (p = 0.018), CA9 (p = 0.030), and VHL-1(p = 0.015). Conclusions: Our data suggested that altered expression of certain members involved in the main pathways which feed RCC and their downstream targets analyzed together could improve the diagnostic accuracy for renal cancer by combining determinations of mRNA markers.

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