Articles de revues : « Porphir »

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Kruk, Mikalai M., Aleksander S. Starukhin et Rafal Czerwieniec. « Temperature-dependent phosphorescence spectra of Pd- and Pt-porphins and their applications ». Journal of Porphyrins and Phthalocyanines 12, n^o 11 (novembre 2008) : 1201–10. http://dx.doi.org/10.1142/s1088424608000583.

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In this paper the temperature dependence of radiative deactivation of Pd - and Pt -porphin triplet states in Shpol'skii matrices has been studied in the temperature range of 4.2-210 K. Dramatic changes in the phosphorescence spectra, with increasing temperature, were observed. It has been proposed that this is due to the inclusion of thermally activated states of the studied molecules in the processes of radiative deactivation of triplet states. For Pd -porphin the T 1 → S 0 emission is merely observed at liquid helium temperature. An increase in temperature leads to the activation of several radiative T i → S 0 transitions, so additional bands appear in the phosphorescence spectrum. In the case of Pt -porphin, temperature activation takes place as early as at liquid helium temperature. The degeneracy lifting of lowest T 1,2 states due to crystal field splitting was observed for both Pd - and Pt -porphins. The splitting value δ = ΔE( T 2 − T 1) has been measured in different matrices and the dependencies on both the metal ion in the given matrix and the matrix type for the given metal ion, have been revealed. The possibility of designing the luminescent molecular thermometers for cryogenic temperatures based on the high temperature sensitivity of the Pd - and Pt -porphin phosphorescence in n-alkane matrices, has been discussed. The workability of the dependence of Pd - and Pt -porphin phosphorescent properties on temperature in the design of the molecular thermometer family for the temperature range from a few K up to temperatures close to the melting point of n-alkane matrix (150-200 K) is demonstrated.

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Lafleur, Claude, et Joanne Carrier. « Ockham : logique et universaux isagogiques ». Dossier 76, n^o 2 (25 mai 2021) : 197–223. http://dx.doi.org/10.7202/1077445ar.

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En tant qu’introduction générale aux commentaires d’Ockham sur la logique, celle de Porphyre et d’Aristote, l’Expositionis in libros artis logice Prohemium traite la nature de cette discipline, de son sujet, de son utilité, de sa spécificité et de son statut épistémologique. La nouvelle traduction française ici offerte est accompagnée d’une édition annotée qui restitue l’orthographe médiévale du latin d’Ockham. Il en va de même pour la nouvelle traduction du début du premier commentaire logique d’Ockham, l’Expositio in librum Porphirii De predicabilibus, dont le moment fort est l’interprétation des questions de Porphyre sur les universaux (genres et espèces).

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Redwood, Stewart D. « The Origin of the Porphyry Deposit Name : From Shellfish, Tyrian Purple Dye, and Imperial Rome to the World’s Largest Copper Deposits ». SEG Discovery, n^o 118 (1 juillet 2019) : 1–15. http://dx.doi.org/10.5382/segnews.2019-118.fea.

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Abstract The porphyry deposit name has a long and fascinating etymological history of over 3,000 years. “Porphyry” is derived from the ancient Greek word porphyra (πoρϕύρα), or purple. It was originally applied to a rare purple dye, Tyrian purple, extracted by the Phoenicians from murex shells. It was later applied to a prized purple porphyritic rock, Imperial Porphyry or Porfido rosso attico, quarried by the Romans from Mons Porphyrites in the Eastern Red Sea hills of Egypt from the first to fifth centuries A.D., and used as a monumental stone in Imperial Rome and Byzantium (Istanbul). The name evolved in the field of igneous petrology to include all rocks with a porphyritic texture, regardless of their color. Mining of the first porphyry copper deposits, which were originally called disseminated or low-grade copper deposits, started in 1905. As a result of the close spatial and genetic relationship to porphyry stocks, they became known as porphyry copper deposits. The term was first used by W. H. Emmons in his 1918 textbook The Principles of Economic Geology, but it was originally used more as an engineering and economic description, as in Parsons’ 1933 book The Porphyry Coppers. It was slow to catch on in the geological literature. It was first used in the title of a paper in Economic Geology in 1947 but did not gain widespread use until the 1970s, following the publication of seminal papers on porphyry models and genesis by Lowell and Guilbert (1970) and Sillitoe (1972, 1973).

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Mastrocinque, Attilio. « The Mithraic praesepia as Dining Beds ». Acta Antiqua Academiae Scientiarum Hungaricae 58, n^o 1-4 (décembre 2018) : 421–26. http://dx.doi.org/10.1556/068.2018.58.1-4.25.

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Summary A mithraeum always has long benches, which were called praesepiae, “places where cattle are fed in a stall” (CIMRM 233). The name is inappropriate for a dining room, which was usually called, instead, triclinium. Mithraeum is the current modern name, whereas the ancients called it spelaeum, antrum, templum. Another important name was Leonteum, which was not a separate cultic place for Leones only, because Porphyry states that the members of a Mithraic community were the Leones and the servants were called Korakes, the Ravens (Porphyr. de abst. 4. 16). The Mithraic menu apparently consisted of meat rather than of vegetables, even though one should take into account the fact that bones are better preserved than vegetables in an archaeological site, and therefore they are often published, whereas vegetal remains had never been investigated by means of chemical analyses. Lions are notoriously carnivorous and the praesepiae had to be filled with meat for the Leones. The initiation of Leones was supposed to be dry and fiery (Tert. Adv. Marcionem I 13), and we are also told that the Mithraic Leones avoided water for their purifications and washed their hands with honey (Porph. De antro 15–16). Moreover, a lion and a snake are often depicted on Mithraic reliefs as going to drink from a crater. It is possible to get some information from those facts about what Leones were used to drinking during their symposia: they were thirsty but their drink could not be water, but eventually, wine was permitted. Iustin. Apol. I 66 speaks of a cup of water, but only to mention some ritual acts during initiations and not during symposia.

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Lim, Richard. « The auditor Thaumasius in the Vita Plotini ». Journal of Hellenic Studies 113 (novembre 1993) : 157–60. http://dx.doi.org/10.2307/632405.

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In his Vita Plotini, Porphyry recounts a colourful episode which, for a brief moment, brings to life the dynamics within the lecture room of Plotinus in Rome. The author explains how he was in the habit of posing questions to Plotinus frequently and persistently while his teacher was conducting his philosophical discourse before a mixed body of listeners. On one occasion, such an exchange between the two over the issue of the connexion between the soul and the body continued intermittently over a period of some three days, with the following outcome (Porph. V. Plot. xiii 12-15):

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Broom, J. E., W. A. Nelson, W. A. Jones, C. Yarish, R. Aguilar Rosas et L. E. Aguilar Rosas. « PORPHYRA SUBORBICULATA, PORPHYRA CAROLINENSIS AND PORPHYRA LILLIPUTIANA ‐ THREE NAMES FOR ONE SMALL PORPHYRA ». Journal of Phycology 36, s3 (décembre 2000) : 7–8. http://dx.doi.org/10.1046/j.1529-8817.1999.00001-21.x.

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Kim, Su Yeon, Won Kyong Cho, Hye-In Kim, Seung Hye Paek, Sung Joo Jang, Yeonhwa Jo, Hoseong Choi, Jeong Hun Lee et Sang Hyun Moh. « Transcriptome Profiling of Human Follicle Dermal Papilla Cells in response to Porphyra-334 Treatment by RNA-Seq ». Evidence-Based Complementary and Alternative Medicine 2021 (13 janvier 2021) : 1–15. http://dx.doi.org/10.1155/2021/6637513.

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Porphyra-334 is a kind of mycosporine-like amino acid absorbing ultraviolet-A. Here, we characterized porphyra-334 as a potential antiaging agent. An in vitro assay revealed that porphyra-334 dramatically promoted collagen synthesis in fibroblast cells. The effect of porphyra-334 on cell proliferation was dependent on the cell type, and the increase of cell viability by porphyra-334 was the highest in keratinocyte cells among the three tested cell types. An in vivo clinical test with 22 participants demonstrated the possible role of porphyra-334 in the improvement of periorbital wrinkles. RNA-sequencing using human follicle dermal papilla (HFDP) cells upon porphyra-334 treatment identified the upregulation of metallothionein- (MT-) associated genes, confirming the antioxidant role of porphyra-334 with MT. Moreover, the expression of genes involved in nuclear chromosome segregation and the encoding of components of kinetochores was upregulated by porphyra-334 treatment. Furthermore, we found that several genes associated with the hair follicle cycle, the hair follicle structure, the epidermal structure, and stem cells were upregulated by porphyra-334 treatment, suggesting the potential role of porphyra-334 in hair follicle growth and maintenance. In summary, we provided several new pieces of evidence of porphyra-334 as a potential antiaging cosmetic agent and elucidated the expression network in HFDP cells upon porphyra-334.

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MIGACHEV, Igor, Vadim ZVEZDOV et Olga MININA. « Formational types of porphyry copper deposits and their ore-magmatic systems ». Domestic geology, n^o 1 (21 mars 2022) : 26–48. http://dx.doi.org/10.47765/0869-7175-2022-10002.

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Two individual ore-formational types have been identified within the porphyry copper family: the gold-copper-porphyry and molybdenum-copper-porphyry ones. The fundamental difference between them lies in their geotectonic position that determines the origin and composition of fertile magmatic source, as well as other features the composition of ore-bearing porphyry intrusions, the mineralogical and geochemical features of ores, and the pattern of metasomatic and ore zonation. In this study, we investigated porphyry copper ore-magmatic systems with complex metallogeny, or complex porphyry copper systems (CPCS), where porphyry copper deposits constitute the core elements spatially associated with mineralization of other ore-formational types. Based on a set of conjugated and combined types of ore mineralization we established the differences between diorite-related gold-copper-porphyry CPCS, formed in basaltic volcano-plutonic belts, and granodiorite-monzonite-related molybdenum-copper-porphyry CPCS, formed in andesite belts. These differences confirm the validity of the distinction of the two ore-formational types of deposits of the porphyry-copper family.

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Sheinin, Vladimir B., Sergey A. Shabunin, Elena V. Bobritskaya, Tatiana A. Ageeva et Oscar I. Koifman. « Protonation Equilibriums of Porphin, 5,10,15,20-Tetraphenylporphin, 5,10,15,20-Tetrakis(4’-sulfonatophenyl)porphin in Methanol ». Macroheterocycles 5, n^o 3 (2012) : 252–59. http://dx.doi.org/10.6060/mhc2012.120989s.

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Li, Weidong, Zhihong Wei, Boyang Wang, Yuan Liu, Haoqiang Song, Zhiyong Tang, Bai Yang et Siyu Lu. « Carbon quantum dots enhanced the activity for the hydrogen evolution reaction in ruthenium-based electrocatalysts ». Materials Chemistry Frontiers 4, n^o 1 (2020) : 277–84. http://dx.doi.org/10.1039/c9qm00618d.

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The Ru supported on Porphyra-CQDs exhibited better dispersibility and the highest activity compared with biomass Porphyra and Porphyra activated carbon owing to the strong coordination interactions between Ru and CQDs.

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BUCHKO, INNA VLADIMIROVNA, et IVAN ALEXANDROVICH YATSENKO. « FORECASTING GEOCHEMICAL PREREQUISITES FOR DETECTING THE PORPHYROUS SYSTEM IN THE KOMSOMOLSK REGION OF KHABAROVSK REGION ». Messenger AmSU, n^o 93 (2021) : 126–30. http://dx.doi.org/10.22250/jasu.93.26.

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The information on the results of geological exploration work to identify the porphyry system in the Komsomolsk region of the Khabarovsk Territory is given. It is shown that copper-molybdenum-porphyry mineralization is associated with the type of porphyry deposits by a porphyry stock surrounded by fields of hydrothermal-metasomatic alteration. The possibilities of the object of the gold-rare metal type are substantiated.

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Vogel, Emanuel, Matthias Köcher, Hans Schmickler et Johann Lex. « Porphycen – ein neuartiges Porphin-Isomer ». Angewandte Chemie 98, n^o 3 (mars 1986) : 262–64. http://dx.doi.org/10.1002/ange.19860980314.

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Vogel, Emanuel, Matthias Köcher, Hans Schmickler et Johann Lex. « Porphycene-a Novel Porphin Isomer ». Angewandte Chemie International Edition in English 25, n^o 3 (mars 1986) : 257–59. http://dx.doi.org/10.1002/anie.198602571.

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Murad, Fida, Abdul Ghaffar, Innayat Ullah, Abdul Shakoor Mastoi et Muhammad Tariq Zaman. « The Alteration and Mineralization Characteristics of Miocene Porphyry Cu-Au Deposits of Chagai Magmatic Belt, District Chagai, Balochistan, Pakistan ». International Journal of Economic and Environmental Geology 12, n^o 1 (8 juin 2021) : 1–8. http://dx.doi.org/10.46660/ijeeg.vol12.iss1.2021.550.

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Subduction related Miocene porphyry type deposits are found in the east-west trending Chagai magmatic belt (CMB) in Pakistan's western margin, Balochistan. This arc exists on the west segment of the Tethyan metallogenic belt in the south-west of Pakistan. Tethyan metallogenic belt is widely spread over 12,000 km from east to west direction from Indochina, Tibet, Pakistan, Iran, Turkey and Alpine mountain range in Europe. During the last thirty to forty years several porphyry deposits have been reported in the Chagai magmatic arc, including the very large Reko Diq H14-H15, large Saindak, Tanjeel, H35, H8 and medium Dasht-e-Kain porphyry deposits and many small porphyry copper deposits. These porphyry deposits were developed within the phase of calc-alkaline type magmatism in the Chagai arc. Tonalite, quartz diorite, and monzonite host the porphyry deposits within the adjacent sedimentary wall rock units of Sinjrani Volcanic Group, Juzzak, Saindak, and Amalaf Formations. The concentric zonal pattern of hydrothermal alteration in these porphyry deposits of the Chagai magmatic arc follows the world's major porphyry deposits' alteration pattern. Zones of hydrothermal alteration from distal to proximal part includesa potassic alteration, sericitic-clay-chlorite alteration, sericitic alteration, argillic alteration and propylitic alteration. Major ore mineralization in these deposits is of copper, gold, silver, molybdenum, and minor constituents of other base metals that have been reported to occur within hydrothermal alteration zones in the Miocene porphyry Chagai magmatic arc

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Lindstrom, Sandra C., et Kathleen M. Cole. « A revision of the species of Porphyra (Rhodophyta : Bangiales) occurring in British Columbia and adjacent waters ». Canadian Journal of Botany 70, n^o 10 (1 octobre 1992) : 2066–75. http://dx.doi.org/10.1139/b92-256.

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Starch gel electrophoresis of proteins of Porphyra species occurring in British Columbia and nearby areas has provided new data on species identities. One new species is described, Porphyra kurogii (formerly identified as North Pacific P. purpurea), and its eastern Pacific distribution limit is extended from northern to southern British Columbia. Porphyra maculosa is recognized to be a taxonomic synonym of P. fucicola; new distribution records are provided. Porphyra cuneiformis is the correct name for specimens formerly identified as P. miniata in the area, and P. occidentalis is the correct name for most local specimens of P. "variegata." A key to the 21 species and 2 subspecies of Porphyra currently recognized in Oregon, Washington, British Columbia, and southeast Alaska is provided. The key includes the recently described P. mumfordii, P. fallax ssp. fallax, and P. fallax ssp. conwayae. Key words: isozymes, key, Porphyra, taxonomy.

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Wang, Xiao, Li Li, Kun Zhang, Zhen Han, Zhijian Ding, Mingwei Lv, Pan Wang, Quanhong Liu et Xiaobing Wang. « Synthesis and evolution of S-Porphin sodium as a potential antitumor agent for photodynamic therapy against breast cancer ». Organic Chemistry Frontiers 6, n^o 3 (2019) : 362–72. http://dx.doi.org/10.1039/c8qo00959g.

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Zheng, Yulin, Changqing Zhang, Fudong Jia, Huan Liu et Qinggao Yan. « Apatite and Zircon Geochemistry in Yao’an Alkali-Rich Porphyry Gold Deposit, Southwest China : Implications for Petrogenesis and Mineralization ». Minerals 11, n^o 11 (20 novembre 2021) : 1293. http://dx.doi.org/10.3390/min11111293.

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The Yao’an gold deposit is located in the middle of the Jinshajiang-Ailaoshan alkali-rich metallogenic belt, and this belt hosts many porphyry-type Cu-Au-Mo deposits formed at 46–33 Ma. Yao’an porphyry gold-mineralization is intimately associated with biotite syenite porphyry, whereas the contemporaneous quartz syenite porphyry is barren. In this study, we compared the major and trace elements of apatite and zircon and isotopic compositions of zircon from the biotite syenite porphyry and quartz syenite porphyry, to explore their geochemical differences that may affect their mineralization potential. The results show that both porphyries were derived from the partial melting of the thickened lower crust, which has been modified by slab-derived fluids, but has different mineral crystallization sequences, magma fluid activities, and magma oxidation states, respectively. REE contents in apatite and zircon can be used to reveal the crystallization sequence of minerals. A rapid decrease of (La/Yb)N ratio in apatite from both porphyries may be caused by the crystallization of allanite. Large variation of Cl contents and negative correlation between F/Cl and (La/Yb)N in apatite from fertile porphyry indicate that it has experienced the exsolution of Cl-bearing hydrothermal fluid. Higher Y/Ho and lower Zr/Hf in zircon from fertile porphyry indicate a stronger fluid activity than barren porphyry. The high S, V, As contents, δEu, low δCe in apatite, as well as high Ce4+/Ce3+ and log(fO2) estimated from zircon geochemistry from fertile porphyry, indicate high a oxidation state of fertile porphyry, similar to other fertile porphyries in this metallogenic belt. High fluid activity and fluid exsolution are conducive to the migration and enrichment of metal elements, which are very important for mineralization. High oxygen fugacity inhibits the precipitation of metal in the form of sulfide, thereby enhancing the mineralization potential of rock. Therefore, the exsolution of Cl-bearing hydrothermal fluid and high oxygen fugacity are the key factors promoting mineralization in Yao’an area.

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Yamasaki, Takashi, Yuka Miyazaki et Yuto Kamei. « Isolation of bacteria that decompose major polysaccharides in the cell wall of the marine red alga Porphyra yezoensis and their application for protoplast production ». Canadian Journal of Microbiology 44, n^o 8 (1 août 1998) : 789–94. http://dx.doi.org/10.1139/w98-070.

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We attempted to screen for bacteria that could decompose major polysaccharides in the cell wall of the marine red alga Porphyra yezoensis from Porphyra-culturing farms to enable simple and high-yield preparation of protoplasts with the crude enzyme from a single bacterial origin. A total of 275 positive bacterial strains were isolated by enrichment culture supplemented with Porphyra powder or xylan. Nine strains were capable of producing protoplasts from Porphyra thalli in a 10-fold concentrated culture broth. These strains were identified as two Flavobacterium spp., one Alteromonas sp., four Acinetobacter spp., and two Vibrio spp. The crude enzymes of these bacteria could release 106 protoplast cells from 0.1 g of Porphyra thalli. The crude enzyme from Alteromonas sp. strain ND137 produced the most protoplasts among the nine strains tested. Moreover, an assay of the crude enzymes from the nine bacterial strains for glycosidase activity against four major polysaccharides (xylan, mannan, porphyran, and cellulose) of P. yezoensis revealed strong decomposing activity against these polysaccharides. Xylanase activity was highest in these glycosidases, suggesting that xylanase might be a very important factor in producing protoplasts from Porphyra thalli.Key words: Porphyra, cell wall, bacteria, decomposing polysaccharide.

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Ibbeken, Hillert, et Christian G. Hirschberg. « The porphyry gravels of the Werra and Weser rivers, a sedimentological enigma ». Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 214, n^o 1-2 (10 novembre 1999) : 25–43. http://dx.doi.org/10.1127/njgpa/214/1999/25.

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An, Weicai, Chunji Xue, Yun Zhao et Chao Li. « Two Periods of Porphyry Cu Mineralization and Metallogenic Implications in the Tuwu–Yandong Belt (NW China), Based on Re–Os Systematics of Molybdenite ». Minerals 12, n^o 9 (5 septembre 2022) : 1127. http://dx.doi.org/10.3390/min12091127.

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The Tuwu–Yandong belt contains five porphyry Cu deposits (Fuxing, Yandong, Tuwu, Linglong, and Chihu), constituting the largest Cu metallogenic belt in Northwest China. However, the metallogenic framework for porphyry Cu deposits in the belt remains controversial. Rhenium-osmium dating of molybdenite from the Tuwu, Linglong, and Chihu deposits and comparisons with previous geochronological data of five deposits suggest that two episodes (335–330 Ma and 323–315 Ma) of porphyry Cu–Mo mineralization occurred in the Tuwu–Yandong belt, and the metals were mainly sourced from the mantle. Moreover, combined with the geodynamic framework of this belt, the compressional environment may be more favorable for porphyry Cu mineralization, and further exploration into the Early Carboniferous porphyry Cu deposits in this belt is expected.

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Choi, Seoyoung, Jeong Hun Lee, Sae Woong Oh, Eunbi Yu, Kitae Kwon, Sung Joo Jang, Dong Sun Shin, Sang Hyun Moh et Jongsung Lee. « Anti-Pollutant Activity of Porphyra yezoensis Water Extract and Its Active Compound, Porphyra 334, against Urban Particulate Matter-Induced Keratinocyte Cell Damage ». Marine Drugs 21, n^o 2 (13 février 2023) : 121. http://dx.doi.org/10.3390/md21020121.

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Urban particulate matter (UPM) causes skin aging and inflammatory reactions by influencing skin cells through the aryl hydrocarbon receptor (AhR) signaling pathway. Porphyra yezoensis (also known as Pyropia yezoensis), a red alga belonging to the Bangiaceae family, is an edible red seaweed. Here, we examined the anti-pollutant effect of P. yezoensis water extract. While UPM treatment induced xenobiotic response element (XRE) promoter luciferase activity, P. yezoensis water extract reduced UPM-induced XRE activity. Next, we isolated an active compound from P. yezoensis and identified it as porphyra 334. Similar to the P. yezoensis water extract, porphyra 334 attenuated UPM-induced XRE activity. Moreover, although UPM augmented AhR nuclear translocation, which led to an increase in cytochrome P450 1A1 (CYP1A1) mRNA levels, these effects were reduced by porphyra 334. Moreover, UPM induced the production of reactive oxygen species (ROS) and reduced cell proliferation. These effects were attenuated in response to porphyra 334 treatment. Furthermore, our results revealed that the increased ROS levels induced by UPM treatment induced transient receptor potential vanilloid 1 (TRPV1) activity, which is related to skin aging and inflammatory responses. However, porphyra 334 treatment reduced this reaction by inhibiting ROS production induced by CYP1A1 activation. This indicates that porphyra 334, an active compound of P. yezoensis, attenuates UP-induced cell damage by inhibiting AhR-induced ROS production, which results in a reduction in TRPV1 activation, leading to cell proliferation. This also suggests that porphyra 334 could protect the epidermis from harmful pollutants.

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Galanopoulos, Evangelos, Panagiotis Voudouris, Constantinos Mavrogonatos, Paul Spry, Craig Hart, Vasilios Melfos, Federica Zaccarini et Dimitrios Alfieris. « A New Porphyry Mo Mineralization at Aisymi-Leptokarya, South-Eastern Rhodope, North-East Greece : Geological and Mineralogical Constraints ». Geosciences 8, n^o 12 (24 novembre 2018) : 435. http://dx.doi.org/10.3390/geosciences8120435.

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A new porphyry Mo prospect has been discovered in the Aisymi-Leptokarya area, along the southern margin of the Byala Reka–Kechros metamorphic dome, south-eastern (SE) Rhodope metallogenic zone. The study area is dominated by an Oligocene felsic dike complex, which hosts the porphyry Mo mineralization and intrudes into upper Eocene sandstones-marls and the Leptokarya monzodiorite pluton. The Aisymi-Leptokarya felsic dike complex displays a rhyodacitic to dacitic composition with post-collisional affinities. The porphyry Mo mineralization occurs in the form of porphyry-style quartz stockworks in the felsic dike complex associated with potassic alteration characterized by hydrothermal K-feldspar. The ore minerals consist mainly of pyrite, molybdenite, kesterite, bismuthinite and galena within both the stockwork and the rock matrix. Bulk ore analyses indicate enrichment in Mo (up to 215 ppm), Se (up to 29 ppm), Bi (up to 8 ppm) and Sn (up to 14 ppm) in the porphyry quartz veins. Late-stage, north-east (NE-) and north-west (NW-)trending milky quartz intermediate-sulfidation epithermal veins with base metals, crosscut previous vein generations and are characterized by Ag, Sn and Te anomalies. The Aisymi-Leptokarya porphyry Mo prospect is set in a back-arc geotectonic regime and shares similarities to other post-subduction porphyry molybdenum deposits elsewhere.

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Sapunov, V. V., et G. D. Egorova. « Association of octamethyltetra(p-sulfophenyl)porphin and tetra(4-N-methylpyridyl)porphin in aqueous solutions ». Journal of Applied Spectroscopy 55, n^o 3 (septembre 1991) : 900–904. http://dx.doi.org/10.1007/bf00662418.

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Tang, Yuyu, Hua Kong, Biao Liu, Qi Zong, Qianhong Wu, Hua Jiang et Fucheng Tan. « Geochronology, Whole-Rock Geochemistry, and Sr–Nd–Hf Isotopes of Granitoids in the Tongshanling Ore Field, South China : Insights into Cu and W Metallogenic Specificity ». Minerals 12, n^o 7 (15 juillet 2022) : 892. http://dx.doi.org/10.3390/min12070892.

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The Qin-Hang Metallogenic Belt (QHMB), an important metallogenic belt in South China, hosts Cu and W–Sn polymetallic deposits. The Tongshanling ore field in the QHMB is characterized by the coexistence of Cu- and W-bearing polymetallic deposits, which are related to granodiorite and granite porphyry. This study examined whole-rock geochemistry, geochronology, and Sr–Nd–Hf isotopes to determine the genetic relationship between diverse ore-related granitoids (i.e., granodiorite and granite porphyry) and Cu–W metallogeny in the Tongshanling ore field. Zircon LA-ICP-MS U–Pb dating shows that the granodiorite and granite porphyry in the Tongshanling ore field were emplaced at 163.7 ± 0.4 Ma to 154.7 ± 0.6 Ma and 161.1 ± 0.3 Ma, respectively. Geochemically, the granodiorites are classified as oxidized I-type, while the highly evolved granite porphyry is reduced A-type. The Lu–Hf isotopic composition of the granodiorites is characterized by εHf(t) values ranging from –10.49 to –4.99 (average = –7.17), with corresponding TDMC ages ranging from 1524 to 1877 Ma (average = 1682 Ma). In contrast, the granite porphyry has higher εHf(t) values (–3.60 to –1.58, average = –2.78) and younger TDMC (1310–1438 Ma, average = 1387 Ma). The εNd(t) values of granodiorite are −8.06 to −7.37 and the two-stage model ages (TDM2) are 1543–1598 Ma, while the granite porphyry has higher εNd(t) values (−3.0 to −3.4) and younger TDM2 ages (1195–1223 Ma). The results show that the granodiorite and granite porphyry were formed from partial melting of different Mesoproterozoic basement rocks under varying degrees of crust–mantle interaction. Granite porphyry underwent well-recorded fractional crystallization. Compared to the Cu-forming granodiorite, the W-forming granite porphyry has a higher differentiation index, higher crystallization temperatures of zircon (average = 708 °C versus 631 °C), and lower oxygen fugacity (median ΔFMQ = –2.21 versus –1.77).

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Prokofiev, Vsevolod Yu, et Vladimir B. Naumov. « Ranges of Physical Parameters and Geochemical Features of Mineralizing Fluids at Porphyry Deposits of Various Types of the Cu−Mo−Au System : Evidence from Fluid Inclusions Data ». Minerals 12, n^o 5 (24 avril 2022) : 529. http://dx.doi.org/10.3390/min12050529.

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The paper reviews and summarizes data on the physicochemical parameters and chemical features of mineralizing fluids at porphyry deposits of the Cu–Mo–Au system. The calculated average values and ranges of parameters of the fluids in mineral-hosted fluid inclusions at porphyry deposits are as follows: temperature 90–957 °C, average 388 °C; salinity 0.1–88.0 wt % equiv. NaCl, average 29.4 wt % equiv. NaCl; and density 0.38–1.85 g/cm3, average 0.93 g/cm3. The highest average temperature and the highest maximum homogenization temperatures of the fluids were detected at deposits of the Cu (Au) type, with both values systematically decreasing with the transition to the Cu, Mo (Au), and then to Mo and Au types of porphyry deposits. The situations with the average and maximum salinity values of the fluids and their density are analogous. The data in the literature on the concentrations of some elements are still insufficient to reliably characterize variations in these concentrations at all of the discussed types of porphyry deposits. The highest Cu and Fe concentrations were found in the highest temperature fluids at deposits of the Cu (Au) type. The maximum Mo concentrations were detected in fluids at porphyry Mo deposits, and the highest Ag concentrations occurred at porphyry Au deposits. The chemical composition of the mineralizing fluids is, thus, strongly correlated with the types of the porphyry deposits. The hypothesis is discussed: the geochemical specifics of mineralizing fluids at various types of porphyry deposits of the Cu–Mo–Au system are related to the depths at which fluid separated from the magmatic melt. A scenario is proposed for the separation of mineralizing fluids from granite melt at various depths for fluids that form different types of porphyry deposits.

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Li, Ying Chang, Ya Li Wang et Zuo Wei Li. « Optimization of Extraction Process of Water-Soluble Polysaccharides from Porphyra by Response Surface Methodology ». Advanced Materials Research 864-867 (décembre 2013) : 526–30. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.526.

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Polysaccharide from Porphyra is a kind of important biological active substance. Therefore，it is significant to effectively develop and utilize the polysaccharide from porphyra and improve the economic and social benefits of porphyra. In this paper, polysaccharide was extracted by the method of hot water immersed extraction and ethanol precipitation. Extraction process of water-soluble polysaccharides from Porphyra was optimized by response surface methodology. The content of polysaccharide was determined by sulfuric acid to phenol method. The results show that the extraction time is 4.4 h, extraction temperature is 88°Cand the ratio of material to liquid is1:42(g/mL). Polysaccharide is precipitated with 5 folds volume of ethanol for 6 h. The proportion of the extraction of the porphyra polysaccharide under this industrial process conditions is 10.012%.

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Allou, Gnanzou, Boya Kakeu Tokpa Dimitri Lionel, Coulibaly Inza, Bamba Ibrahim Eric et Coulibaly Yacouba. « Etude Metallogenique du Prospect Aurifere de Woulo-Woulo (Zone d’Afema, Sud-est de la Cote d’Ivore) ». European Scientific Journal, ESJ 18, n^o 33 (31 octobre 2022) : 121. http://dx.doi.org/10.19044/esj.2022.v18n33p121.

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Le prospect de Woulo-Woulo est situé au sud-est de la Côte d’Ivoire, précisément dans la zone de Maféré, à environ 8 km à l’ouest du couloir de cisaillement d’Aféma. Les activités de terrain et de forage ont montré que certaines formations observées sur le prospect de Woulo-Woulo contiennent de la minéralisation aurifère. L’objectif général de cette étude est de déterminer les caractéristiques pétrographiques et structurales de ces roches et la minéralisation aurifère associée. Ainsi, l’acquisition des données a consisté au prélèvement d’échantillons de roches de terrain et de forage carotté, suivi de leur caractérisation macroscopique et microscopique. Le prospect de Woulo-Woulo est constitué de métasédiments (métagrauwackes et métaargilites), de métavolcanites (laves andésitiques et brèches), de filons acides (métarhyolite à porphyre de quartz) et d’intrusions de métagabbros, tousp affectées par une importante activité hydrothermale, filonienne, qui a induit une altération pervasive des encaissants. La minéralisation aurifère du prospect de Woulo-Woulo est de type filonien et hydrothermal épigénétique liée aux veines et veinules de quartz et carbonates, encaissée préférentiellement dans la métarhyolite porphyrique déformée et hydrothermalisée. Elle présente donc un contrôle structural. La paragenèse de cette minéralisation est constituée de pyrite (sulfure principal), sphalérite et or natif. The Woulo-Woulo prospect is located in south-eastern Côte d'Ivoire, precisely in the Maféré zone, approximately 8 km west from the Aféma shear zone. Field and drilling activities have shown that certain formations observed at the Woulo-Woulo prospect contain gold mineralization. The overall objective of this study is to determine the petrographic and structural characteristics of these rocks and the associated gold mineralization. Thus, data acquisition consisted of field and core sampling followed by macroscopic and microscopic characterization. The Woulo-Woulo prospect consists of metasediments (metagrauwackes and metaargilites), metavolcanites (andesitic lavas and breccias), felsic veins (quartz porphyry metarhyolite) and metagabbro intrusions, all affected by significant hydrothermal and vein activity, which induced pervasive alteration of host rocks. The gold mineralization at the Woulo-Woulo prospect is vein-type and epigenetic hydrothermal type related to quartz and carbonate veins and veinlets, hosted preferentially in the deformed and hydrothermalized porphyry metarhyolite. It is therefore structurally controlled. The paragenesis of this mineralization consists of pyrite (main sulfide), sphalerite and native gold.

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Xu, Zhi-Tao, Jing-Gui Sun, Feng-Zhi Lei, Ji-Long Han et Ke-Yao Zhang. « Geochronology, geochemistry, and Pb–Hf isotopes of mineralization-related magmatism in the Dongyang gold deposit, Fujian Province, southeastern China ». Canadian Journal of Earth Sciences 57, n^o 5 (mai 2020) : 553–74. http://dx.doi.org/10.1139/cjes-2019-0006.

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The recently discovered Dongyang low-sulphidation epithermal Au deposit is located in Fujian Province. The Au mineralization hosted in rhyolite porphyry and the Lower Jurassic Nayuan Formation continental volcanic rocks is considered to be related to intermediate–acidic intrusions (rhyolite porphyry, quartz diorite porphyry, and dacite porphyry). The zircon U–Pb ages of these samples are 160.3 ± 0.8, 156.6 ± 0.8, and 154.1 ± 0.6 Ma, respectively, and the sulphide Rb–Sr isotope isochron age is 152.4 ± 1.7 Ma, indicating a temporal link between porphyry emplacement and Au mineralization. Porphyries are enriched in large-ion lithophile elements and light rare earth elements and slightly depleted in heavy rare earth elements and high field strength elements, belong to the high-potassium calc-alkaline or shoshonitic series, and show characteristics of volcanic arcs or active continental margins. Moreover, the εHf(t) values of the porphyries range from −11.6 to −7.6, −11.2 to −5.4, and −9.8 to −4.6, respectively. The 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb values of the ore minerals are from 38.417 to 38.406, 15.603, and from 18.179 to 18.175, respectively. Pb and Hf isotopes indicate that the intermediate–acidic magma related to mineralization originated from Mesoproterozoic lower crust. Consequently, these data favour an intermediate–acidic magma origin for Au mineralization in the Dongyang deposit. Integrating new and published data on the tectonic evolution, we suggest that the rhyolite porphyry, quartz diorite porphyry, dacite porphyry, and associated Au mineralization in the Dongyang deposit formed at 160–152 Ma in an extensional environment related to subduction of the Palaeo-Pacific Plate beneath the South China block.

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Klochkova, T. A., et G. H. Kim. « Diseases of the red seaweed Pyropia (= Porphyra) in Korean sea farms ». Bulletin оf Kamchatka State Technical University, n^o 32 (2015) : 48–52. http://dx.doi.org/10.17217/2079-0333-2015-32-48-52.

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Han, Chang-Cheng, Xue-Bing Zhang, Shi-Shan Wu et Ying-Ting Liu. « The Magmatic-Hydrothermal Ore-Forming Processes of the Tonggou Cu-Zn Deposit, NW China : Constraints from Magnetite Chemistry and Fluid Inclusions ». Minerals 12, n^o 4 (15 avril 2022) : 485. http://dx.doi.org/10.3390/min12040485.

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The Tonggou deposit is a porphyry Cu and vein-type Cu-Zn mineralization system located in the Bogda Orogenic Belt, north of Eastern Tianshan. Systematic fluid inclusion analyses were performed on granular quartz from the magnetite–quartz stage and pyrite–chalcopyrite–quartz stage from the porphyry Cu mineralization. During the early stage of porphyry Cu mineralization, the ore-forming fluids were at high temperatures (450–501 °C) and high salinity (51.2–55.2 wt.% NaCl equiv.) H2O-NaCl hydrothermal fluids with fluid boiling. These fluids evolved to high temperature (412–450 °C) and intermediate to low salinity (8.3–14.2 wt.% NaCl equiv.) H2O-NaCl hydrothermal fluids during the pyrite–chalcopyrite–quartz stage. In addition, magnetite from the Tonggou deposit was studied as a marker for the ore-forming process evolution of porphyry and vein-type mineralization. Sampled magnetite can be divided into MagI (allotriomorphic magnetite from altered granodiorite), MagII (magnetite from altered granodiorite found in veinlets or as granular aggregates), MagIII (from the magnetite–quartz stage of porphyry mineralization), and MagIV (from the polymetallic sulfide–epidote–quartz stage of vein-type mineralization). Magnetite LA-ICP-MS data indicate a hydrothermal origin. The contents of Ti, Si, Al, and Ta are controlled by temperature, and these elements gradually decrease from MagI to MagIV. Moreover, fO2 has considerable influence on the substitution of Sn, V, and Mn in magnetite, and the contents of these elements generally decrease from MagI to MagIII—increasing only in MagIV. Indeed, high fO2 in the polymetallic sulfide–epidote–quartz stage (MagIV) of vein-type mineralization is shown by the presence of a replacement texture in ilmenite grains within hydrothermal magnetite. On the other hand, magnetite samples from the Tonggou deposit have relatively low Ti + V contents compared to other porphyry Cu deposits—plotting in the skarn field of the (Ti + V) vs. (Ca + Al + Mn) diagram—and shows negative correlations in the (Ti + V) vs. Sn diagram. These data indicate that the porphyry Cu mineralization at Tonggou formed at relatively lower fO2 conditions than the Tonggou vein-type mineralization and other typical porphyry Cu deposits. Finally, porphyry and vein-type mineralization at Tonggou are both sourced from the porphyry system, as a result of ore-forming fluid transfer to a different location.

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Cong, Pang, Wang, Tian, Ying et Huang. « Zircon LA-ICP-MS U-Pb Ages and the Hf Isotopic Composition of the Ore-Bearing Porphyry from the Yanghuidongzi Copper Deposit, Heilongjiang, China, and Its Geological Significance ». Minerals 9, n^o 11 (2 novembre 2019) : 676. http://dx.doi.org/10.3390/min9110676.

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The Yanghuidongzi copper deposit is a typical porphyry copper deposit located at the eastern margin of the Xing’anling-Mongolian Orogenic Belt (XMOB). While much attention have been paid to the ore-forming age of the deposit and the magma source of the ore-bearing porphyry, this paper approaches this issue with the methods of the LA-ICP-MS zircon U-Pb dating and Lu-Hf isotopic composition of the Yanghuidongzi porphyry copper deposit. The results reveal that the Yanghuidongzi porphyry copper deposit was formed in the Early Jurassic (189.6 ± 1.0 Ma), which corresponds to the time of magmatic activity in this region. The background studies of ore-forming dynamics indicate that the formation of the Yanghuidongzi copper deposit is related to the subduction of the Paleo-Pacific plate. The Yanghuidongzi ore-bearing porphyry zircons have a positive εHf(t) value (4.4–7.0), a high 176Hf/177Hf ratio (0.282786–0.282854), and a two-stage Hf model ages (TDM2) ranging from 783 Ma to 943 Ma, all of which suggest that the Early Jurassic granodiorite porphyry of the Yanghuidongzi deposit was formed by the partial melting of newly grown crustal material from the depleted mantle in the Neoproterozoic.

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Eliopoulos, D. G., et M. Economou-Eliopoulos. « Palladium and platinum in hydrothermal systems : The case of porphyry-Cu systems and sulfides associated with ophiolite complexes. » Bulletin of the Geological Society of Greece 47, n^o 4 (21 décembre 2016) : 1618. http://dx.doi.org/10.12681/bgsg.11002.

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Data on the Pt and Pd contents in sea-floor massive sulfides related to ophiolite complexes indicated elevated Pt contents, up to 1 wt % Pt in sulfides from East Pacific Rise, up to 1000 ppb Pd or Pt in sulfides from mid-Atlantic Ridge and the Pindos ophiolite complex (Greece). Recently, elevated levels of Pd and Pt, have been reported from mineralization associated with alkaline porphyry deposits, such as the Skouries porphyry deposit (Greece), Cordillera of British Columbia, Elatsite (Bulgaria), Santo Tomas II in the Philippines and elsewhere. Current state of knowledge on the solubility of platinum-group elements was applied on hydrothermal systems related to the mineralization in ophiolite complexes and porphyry Cu-Mo-Au±Pd±Pt deposits toward a better understanding of the PGE mineralization in hydrothermal systems and the unknown Pd and Pt potential in porphyry-Cu systems. Ore reserves, mineralogical and geochemical ore data for porphyry-Cu systems are considered to be an encouraging factor for the presence of precious metals. In particular, the occurrence of merenskyite (palladium telluride) associated with chalcopyrite, coupled with the experimental data indicate that porphyry systems are capable to transport significant amounts of Pd and Pt.

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Zhou, Xiong, Yu Zhou et Yi Zhang. « Further Studies of Ore-Forming Fluid Sources of Bangpu Molybdenum-Copper Polymetallic Deposit, Tibet ». Advanced Materials Research 746 (août 2013) : 473–77. http://dx.doi.org/10.4028/www.scientific.net/amr.746.473.

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Bangpu molybdenum-copper polymetallic deposit is located in the eastern section of the Gangdese Porphyry Copper Belt of Tibet. It is a typical large porphyry molybdenum copper polymetallic deposit. The isotope study of fluid inclusions H and O in the quartz (calcite) of various mineralization stages shows that, the ore-forming fluid comes mainly from meteoric hydrothermal caused by atmospheric precipitation, which has consistency with ore-forming fluid sources of Gangdese Porphyry Copper Belt. The Mo-Cu phase with low δD value (-140.5 ~ -104.0 ) suggests a large-scale magmatic degassing. The alteration and mineralization have been caused precisely by the degassing, and the obvious O isotope drift occurred being accompanied by alteration-mineralization, so that the fluid has a low δ18O (vary from 5.50 to 9.0 ). The statistical research indicates that, the massive magmatic degassing occurred in Gangdese Porphyry Copper Belt, and was gradually increased from east to west, suggesting the direct impact of the magmatic degassing on the formation of the porphyry copper-gold deposit and molybdenum copper deposit: the stronger the magmatic degassing, the more easily to form the molybdenum-based porphyry deposit, otherwise it will be formed the deposits dominated by Cu and Au.

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Viltanioti, Irini-Fotini. « Cult Statues in Porphyry of Tyre and Macarius Magnes : Porph. Chr. fr. 76 and fr. 77 (von Harnack) ». Journal of Late Antiquity 10, n^o 1 (2017) : 187–220. http://dx.doi.org/10.1353/jla.2017.0006.

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Li, Ying Chang, Xiao Zhang et Jian Rong Li. « Extraction of Polyphenols from Porphyra and Scavenging Activity of Oxygen Free Radicals ». Advanced Materials Research 864-867 (décembre 2013) : 531–35. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.531.

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Polyphenols from Porphyra are important biological active substances. The effects of temperature, times, ethanol concentration and liquid to solid ratio were studied for the extraction yield of polyphenols from Porphyra through a single-factor exploration.Then, through an orthogonal experiment, it was investigated to get the best extraction conditions. The content of polyphenols was determined by Folin-Ciocalteu method. Scavenging ability to oxygen free radicals was also assessed. The results show that extraction temperature is 75°C, the extraction time is 2.5 h, ethanol concentration is 70% and the ratio of liquid to solid is 25:1(mL/g).The proportion of the extraction of the polyphenols from Porphyra under these industrial process conditions is 6.263mg/g. Polyphenols from Porphyra have strong scavenging hydroxyl radical and superoxide anion radical. IC50 of polyphenols from Porphyra on hydroxyl radical and superoxide anion radical is 0.405 mg/mL, 0.539mg/mL, respectively.

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Senge, Mathias O., et Mia Davis. « Porphyrin (porphine) — A neglected parent compound with potential ». Journal of Porphyrins and Phthalocyanines 14, n^o 07 (juillet 2010) : 557–67. http://dx.doi.org/10.1142/s1088424610002495.

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Porphine is the parent compound of a family of biologically and chemically relevant compounds called porphyrins. The potential of these compounds is enormous and it would be advantageous to use the porphine (porphyrin) unit as a building block for the synthesis of diverse porphyrin complexes with a wide range of applications. However, despite first being synthesized over 70 years ago, porphine has not been utilized to its full extent due to low yield syntheses and poor solubility. Recent advances have now overcome many of these problems. The purpose of this review is to illustrate the advances made in porphine chemistry to illustrate the inherent potential of this simple compound.

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An, Weicai, Chunji Xue, Yun Zhao, Chao Li, Dengfeng Xu et Bo Chen. « Petrogenesis and Tectonic Implications of Late Carboniferous Intrusions in the Tuwu-Yandong Porphyry Cu Belt (NW China) : Constraints from Geochronology, Geochemistry and Sr–Nd–Hf Isotopes ». Minerals 12, n^o 12 (7 décembre 2022) : 1573. http://dx.doi.org/10.3390/min12121573.

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The Tuwu-Yandong porphyry Cu belt is located on the southern margin of the Dananhu island arc in eastern Tianshan, constituting the largest Cu metallogenic belt in Northwest China. Two episodes (~334 Ma and ~317 Ma) of porphyry Cu-Mo mineralization in the belt have been recognized, associated with Early and Late Carboniferous felsic intrusions, respectively. The Carboniferous intrusions, therefore, provide a unique opportunity to investigate tectono-magmatic-metallogenic evolution of the belt. New LA–ICP–MS zircon U–Pb dating indicates that the mineralization-related and post-mineralization intrusions (granodiorite porphyry, gabbro, and granite porphyry) were formed at 321.8 ± 3.1 Ma, 313.5 ± 1.2 Ma, and 309.8 ± 2.5 Ma, respectively. The zircon trace element shows that the granodiorite porphyry (Ce4+/Ce3+ ratios, avg. 129, median = 112, n = 15) was likely derived from a more oxidized (and hydrous) magma source than that of the gabbro (Ce4+/Ce3+ ratios, avg. 74, median = 40, n = 15) and granite porphyry (Ce4+/Ce3+ ratios, avg. 100, median = 91, n = 15), being favorable for porphyry copper mineralization. The granodiorite porphyry shows an adakitic affinity (e.g., high Sr/Y ratios and low Y contents) and has high εNd(t) (6.4–6.7), εHf(t) (11.4–14.3), and Mg# values (47.4–58.1) and low (87Sr/86Sr)i (0.703804–0.703953), suggesting that the melt was derived from partial melting of a subducted oceanic slab followed by mantle peridotite interaction. The gabbro exhibits higher Al2O3 (16.5–17.4 wt.%), Cr (107–172 ppm), and Ni (37–77 ppm) contents and εNd(t) (6.6–7.2), εHf(t) (11.6–15.9), and Mg # (53.3–59.9) values, while it has lower (87Sr/86Sr)i values (0.703681–0.703882) than the granodiorite porphyry, indicating a depleted mantle source. The granite porphyry exhibits an affinity with non-fractionated I-type granites and possesses higher SiO2 (71.1–72.0 wt.%) contents, lower but positive εNd(t) (4.8–5.2), εHf(t) (10.3–13.0), and Mg # (38.7–41.0) values, and higher (87Sr/86Sr)i (0.704544–0.704998) than the granodiorite porphyry and gabbro, together with young Nd and Hf model ages, suggesting that the parental magmas originated from the partial melting of a juvenile lower crust. The enrichment in LREEs and LILEs (e.g., Ba, U, K and Sr) and depletion in HFSEs (e.g., Nb, Ta, and Ti) indicate that these intrusive rocks formed in the subduction zone. With the integration of previous studies, it can be inferred that the northward flat subduction of the Kangguer ocean slab at ca. 335–315 Ma caused the formation of the adakites and associated porphyry Cu mineralization in the Tuwu-Yandong belt. After the prolonged flat subduction, slab rollback may have occurred at ca. 314–310 Ma, followed by a “quiet period” before the final closure of the ancient Tianshan Ocean along the Kangguer Fault in this belt.

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Jimin, Yan, et Zhao Jianguo. « ELECTRONIC STRUCTURE OF THE PORPHIN DIMER ». Acta Physico-Chimica Sinica 2, n^o 06 (1986) : 541–48. http://dx.doi.org/10.3866/pku.whxb19860610.

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Kerwin, James L., Lisa M. Johnson, Howard C. Whisler et Amy R. Tuininga. « Infection and morphogenesis of Pythium marinum in species of Porphyra and other red algae ». Canadian Journal of Botany 70, n^o 5 (1 mai 1992) : 1017–24. http://dx.doi.org/10.1139/b92-126.

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A strain of Pythium marinum (Peronosporales: Pythiaceae) from Puget Sound, Washington, was isolated from lesions of Porphyra nereocystis. The fungus grew on a modified Vishniac medium, from temperatures of 4 to 25 °C, although growth was slow at the lowest temperature. Sexual and asexual reproduction also occurred within this temperature range. Mycelium diluted in seawater initiated zoospore release within 16 h and continued to release zoospores for over 200 h at temperatures from 4 to 20 °C. Zoospore encystment on several species of marine red, brown, and green algae was readily monitored following staining with lactophenol – cotton blue. Pythium marinum zoospore encystment occurred on rhodophyceaen species, including Porphyra (gametophytes), Gigartina exasperata (tetrasporophyte), Mastocarpus papillatus (gametophyte), Prionitis lanceolata (nonfertile), and Iridaea heterocarpa (gametophyte and tetrasporophyte), but not on Nereocystis leutkeana or Ulva lactuca. Over 50% of zoospores held in half-strength seawater at 4 and 20 °C encysted within 24 h, whereas those held at 12 °C reached 50% encystment only after 32 h. For 4-mm diameter discs of Porphyra nereocystis and Porphyra perforata (formerly Porphyra sanjuanensis) blades, there was only a transient relationship between cell damage and number of encysted zoospores. Zoospores did not attach to the conchocelis phase of two species of Porphyra. Sequential extraction of carbohydrates from the blades of Porphyra perforata implicated separate chemical signals for zoospore encystment and appressorium formation prior to the initiation of blade invasion. Addition of diverse monosaccharides and polysaccharides to zoospore suspensions suggested that these chemical signals are specific, with the attachment–encystment signal chemically related to polysaccharides consisting of sulfated or nonsulfated galactose and 3,6-anhydrogalactose found in commercial agars and carrageenans. There was no consistent relationship between zoospore encystment and the amount of 3,6-anhydrogalactose present in the blade phase of several species of red algae. Key words: Pythium, Porphyra, zoospore, encystment, sulfated galactans, 3,6-anhydrogalactose.

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Shaw, Gregory. « Iamblichus and the Talisman of Gnosis ». Gnosis : Journal of Gnostic Studies 2, n^o 2 (17 juillet 2017) : 235–45. http://dx.doi.org/10.1163/2451859x-12340038.

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For Neoplatonic philosophers, the Delphic oracle had authoritatively characterized their two great teachers, Iamblichus and Porphyry. Later Platonists cited the Pythia’s oracular pronouncement, “The Syrian is full of god; the Phoenican a polymath” as revealed wisdom. The Syrian Iamblichus, “full of god,” was more highly regarded in Platonic circles than the learned Porphyry, but because Iamblichus’ theurgical Platonism vanished after the sixth century, we are left with only “learned” reports about theurgic divination. Contemporary scholars are polymaths; we are the children of Porphyry. So, when Porphyry asks for a precise definition of theurgic divination, it seems entirely reasonable, and it is hard for us to appreciate Iamblichus’ barbed response. He chastises Porphyry for presuming that divination can be discursively explained and says he needs a talisman (ἀλεξιοφάρµακον) to protect him from his discursive addiction. Divination, he says, can only be known through experiences that awaken the soul to an innate gnosis that precedes dualist thinking. This paper will explore that talismanic gnosis.

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Sapunov, V. V., et G. D. Egorova. « Association of Pd-tetra(p-sulfophenyl)porphin and tetra(4-N-methylpyridyl)porphin in aqueous solutions ». Journal of Applied Spectroscopy 54, n^o 5 (mai 1991) : 427–32. http://dx.doi.org/10.1007/bf00660016.

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Gladkov, L. L., et K. N. Solovyov. « The normal coordinate analysis of porphin and its derivatives based on the solution of the inverse spectral problem for porphin and Cu porphin—I. A valence force field for in-plane vibrations of the porphin molecule ». Spectrochimica Acta Part A : Molecular Spectroscopy 41, n^o 12 (janvier 1985) : 1437–42. http://dx.doi.org/10.1016/0584-8539(85)80200-2.

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Khosravi, Vahid, Aref Shirazi, Adel Shirazy, Ardeshir Hezarkhani et Amin Beiranvand Pour. « Hybrid Fuzzy-Analytic Hierarchy Process (AHP) Model for Porphyry Copper Prospecting in Simorgh Area, Eastern Lut Block of Iran ». Mining 2, n^o 1 (21 décembre 2021) : 1–12. http://dx.doi.org/10.3390/mining2010001.

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The eastern Lut block of Iran has a high potential for porphyry copper mineralization due to the subduction tectonic regime. It is located in an inaccessible region and has harsh arid conditions for traditional mineral exploration campaigns. The objective of this study is to use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) remote sensing data for porphyry copper exploration in Simorgh Area, eastern Lut block of Iran. Hydrothermal alteration zones such as argillic, phyllic and propylitic zones associated with porphyry copper systems in the study were identified using false color composition (FCC), band ratio (BR), principal component analysis (PCA) and minimal noise fraction (MNF). The thematic alteration layers extracted from FCC, BR, PCA and MNF were integrated using hybrid Fuzzy-AHP model to generate a porphyry copper potential map for the study area. Four high potential zones were identified in the central, western, eastern and northeastern of the study area. Fieldwork was used to validate the approach used in this study. This investigation exhibits that the use of hybrid Fuzzy-AHP model for the identification of hydrothermal alteration zones associated with porphyry copper systems that is typically applicable to ASTER data and can be used for porphyry copper potential mapping in many analogous metallogenic provinces.

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Chniti, Meherzia, Christophe Cassagne, Hongzhen Wang et Georges Boudebs. « Nonlinear properties of unfilled d shell metal porphyrins of 5,10,15,20-tetraphenyl-21H, 23H-porphine cobalt(II) et 5,10,15,20-tetrakis(4-methoxyphenyl)-21H, 23H-porphine cobalt(II) using D4 σ-Z-scan ». Journal of Nonlinear Optical Physics & ; Materials 25, n^o 04 (décembre 2016) : 1650050. http://dx.doi.org/10.1142/s0218863516500508.

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We study the nonlinear (NL) absorption and refraction of 5,10,15,20-tetraphenyl-21H, 23H-porphin cobalt(II) (CoTPP) and 5,10,15,20-tetrakis(4-methoxyphenyl)-21H, 23H-porphin cobalt(II) (MCoTPP). The measurements were carried out in solutions prepared with chlorobenzene applying the D4[Formula: see text]-Z-scan technique with a laser delivering single pulses in the picosecond regime at 532[Formula: see text]nm. For each compounds, the NL coefficients were measured for three concentrations. The results show that these materials with unfilled [Formula: see text] shell exhibit a saturable absorption (SA), where they have been compared to the basic structure tetraphenylporphyrin (TPP) and zinc tetraphenylporphyrin (ZnTPP) with filled [Formula: see text] shell metal in order to see the influence of the central metal ion on the NL absorption (NLA) behavior.

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Suh, Sung-Suk, Se Kyung Oh, Sung Gu Lee, Il-Chan Kim et Sanghee Kim. « Porphyra-334, a mycosporine-like amino acid, attenuates UV-induced apoptosis in HaCaT cells ». Acta Pharmaceutica 67, n^o 2 (27 juin 2017) : 257–64. http://dx.doi.org/10.1515/acph-2017-0015.

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Abstract The main aim of the current research was to study the effect of porphyra-334, one of mycosporine-like amino acids (MAAs), well known as UV-absorbing compounds, on UVinduced apoptosis in human immortalized keratinocyte (HaCaT) cells. Due to their UV-screening capacity and ability to prevent UV-induced DNA damage, MAAs have recently attracted considerable attention in both industry and research in pharmacology. Herein, human HaCaT cells were used to determine the biological activities of porphyra- 334 by various in vitro assays, including proliferation, apoptosis and Western blot assays. The proliferation rate of UV-irradiated HaCaT cells was significantly decreased compared to the control group. Pretreatment with porphyra- 334 markedly attenuated the inhibitory effect of UV and induced a dramatic decrease in the apoptotic rate. Expression of active caspase-3 protein was increased in response to UV irradiation, while caspase-3 levels were similar between cells treated with porphyra-334 and the non-irradiated control group. Taken together, our data suggest that porphyra-334 inhibits UV-induced apoptosis in HaCaT cells through attenuation of the caspase pathway.

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Gladkov, L. L., et K. N. Solovyov. « The normal coordinate analysis of porphin and its derivatives based on the solution of the inverse spectral problem for porphin and Cu porphin—II. A valence force field for in-plane vibrations of the Cu porphin molecule ». Spectrochimica Acta Part A : Molecular Spectroscopy 41, n^o 12 (janvier 1985) : 1443–48. http://dx.doi.org/10.1016/0584-8539(85)80201-4.

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Schöpa, Anne, Catherine Annen, John H. Dilles, R. Stephen J. Sparks et Jon D. Blundy. « Magma Emplacement Rates and Porphyry Copper Deposits : Thermal Modeling of the Yerington Batholith, Nevada ». Economic Geology 112, n^o 7 (1 novembre 2017) : 1653–72. http://dx.doi.org/10.5382/econgeo.2017.4525.

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Abstract Many porphyry copper deposits are associated with granitoid plutons. Porphyry copper deposit genesis is commonly attributed to degassing of pluton-forming intermediate to silicic magma chambers during slow cooling and crystallization. We use numerical simulations of thermal evolution during pluton growth to investigate the links between pluton construction, magma accumulation and solidification, volatile release, and porphyry copper deposit formation. The Jurassic Yerington batholith, Nevada, serves as a case study because of its exceptional exposure, revealing the geometry of three main intrusions. The last intrusion, the Luhr Hill granite, is associated with economic porphyry copper deposits localized over cupolas where dikes and fluid flow were focused. Our simulations for the conceptual model linking porphyry copper deposits with the presence of large, highly molten magma chambers show that the Luhr Hill granite must have been emplaced at a vertical thickening rate of several cm/yr or more. This magma emplacement rate is much higher than the time-averaged formation rates of other batholiths reported in the literature. Such low rates, although common, do not lead to magma accumulation and might be one of the reasons why many granitoid plutons are barren. Based on our results, we formulate the new testable hypothesis of a link between porphyry copper deposit formation and the emplacement time scale of the associated magma intrusion.

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He, Jun, Xiaochun Xu, Zhongyang Fu, Yuhua An, Tianhu Chen, Qiaoqin Xie et Fukun Chen. « Decoupling of Sr-Nd Isotopic Composition Induced by Potassic Alteration in the Shapinggou Porphyry Mo Deposit of the Qinling–Dabie Orogenic Belt, China ». Minerals 11, n^o 8 (23 août 2021) : 910. http://dx.doi.org/10.3390/min11080910.

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In our previous study on petrogenesis of quartz syenite and granite porphyry, the host rocks of the Late Mesozoic Shapinggou Mo deposit in the Qinling–Dabie orogenic belt, we found that the initial Sr isotopic composition of the host rocks is strongly affected by the degree of K-alteration. Here, we provide further isotopic evidence of the host rocks and their minerals to investigate the geochemical behaviour of trace elements and isotopes during the alteration and to explain the phenomenon of decoupling of Sr–Nd isotopic composition. The quartz syenite and granite porphyry are altered by K-alteration in varying degrees and have high K2O and Rb contents and low Na2O, CaO, Sr, and Ba contents. Rock samples of both quartz syenite and granite porphyry have variable Rb/Sr ratios and initial 87Sr/86Sr values (even < 0.70) but contain quite homogeneous εNd(t) values (−12.8 to −14.8). Minerals from the rocks of moderate to intense K-alteration have very low initial 87Sr/86Sr values (even < −17), while those from the weakly altered rocks have 87Sr/86Sr(t) values of 0.7044 to 0.7084. The same phenomenon of the decoupling in Sr–Nd isotopic composition can be observed from several Mo deposits within the eastern Qinling–Dabie orogenic belt. This fact suggests similar hydrothermal features and a comparable origin for both the magmatic rocks and hydrothermal fluids in this belt. A comparison between porphyry Mo and porphyry Cu deposits shows that elements and the Rb–Sr isotope system have different behaviours during the K-alteration, implying distinct material sources and igneous rocks for porphyry Mo and porphyry Cu deposits, respectively.

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McClenaghan, M. B., C. E. Beckett-Brown, M. W. McCurdy et S. Casselman. « Stream Sediment Indicator Mineral Signatures of the Casino Porphyry Cu-Au-Mo Deposit, Yukon, Canada ». Economic Geology 118, n^o 2 (1 mars 2023) : 411–31. http://dx.doi.org/10.5382/econgeo.4970.

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Abstract Case studies around porphyry Cu deposits in the glaciated regions of the Canadian Cordillera have identified the indicator mineral signatures of these deposits in till samples and demonstrated that these are useful methods for porphyry Cu exploration. This study applies the same indicator methods to stream sediment samples around the Casino calc-alkaline porphyry Cu-Au-Mo deposit in the unglaciated terrain of west-central Yukon, Canada. It is one of the largest porphyry Cu-Au-Mo deposits in Canada and is hosted in Late Cretaceous quartz monzonite and associated breccias. Bulk (8–16 kg) coarse-grained stream sediment samples were collected in creeks around the deposit, nearby porphyry Cu occurrences and background areas. The Casino deposit has an obvious indicator mineral signature in the <2-mm heavy (>3.2-specific gravity [SG]) and mid-density (2.8- to 3.2-SG) fractions of stream sediments that is detectable at least 18 km downstream and includes gold, chalcopyrite, tourmaline, molybdenite, sphalerite, jarosite, goethite, and pyrite. In contrast, not all of these mineralogically anomalous samples have corresponding anomalous geochemical signatures in the fine fraction. The porphyry indicator minerals identified in this study are similar to those reported for glaciated terrain with the addition of molybdenite and secondary minerals. Indicator mineral methods provide physical evidence of nearby mineralization and can be chemically analyzed to provide insights about the nature of the mineralizing system. Government and exploration surveys could benefit from the addition of indicator mineral methods to routine stream sediment sampling protocols in unglaciated regions of the Yukon and elsewhere globally where porphyry Cu exploration is conducted.

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Tai, Baoqiang, Wentian Mi, Genhou Wang, Yingjie Li et Xu Kong. « Petrogenesis and Tectonic Setting of Early Cretaceous Intrusive Rocks in the Northern Ulanhot Area, Central and Southern Great Xing’an Range, NE China ». Minerals 11, n^o 12 (14 décembre 2021) : 1414. http://dx.doi.org/10.3390/min11121414.

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Abundant Early Cretaceous magmatism is conserved in the central and southern Great Xing’an Range (GXR) and has significant geodynamic implications for the study of the Late Mesozoic tectonic framework of northeast China. In this study, we provide new high-precision U–Pb zircon geochronology, whole-rock geochemistry, and zircon Hf isotopic data for representative intrusive rocks from the northern part of the Ulanhot area to illustrate the petrogenesis types and magma source of these rocks and evaluate the tectonic setting of the central-southern GXR. Laser ablation inductively coupled plasma–mass spectrometry (LA-ICP-MS) zircon U–Pb dating showed that magmatism in the Ulanhot area (monzonite porphyry: 128.07 ± 0.62 Ma, quartz monzonite porphyry: 127.47 ± 0.36, quartz porphyry: 124.85 ± 0.34, and granite porphyry: 124.15 ± 0.31 Ma) occurred during the Early Cretaceous. Geochemically, monzonite porphyry belongs to the metaluminous and alkaline series rocks and is characterized by high Al2O3 (average 17.74 wt.%) and TiO2 (average 0.88 wt.%) and low Ni (average 4.63 ppm), Cr (average 6.69 ppm), Mg# (average 31.11), Y (average 15.16 ppm), and Yb (average 1.62 ppm) content with enrichment in Ba, K, Pb, Sr, Zr, and Hf and depletion in Ti, Nb, and Ta. The granitic rocks (e.g., quartz monzonite porphyry, quartz porphyry, and granite porphyry) pertain to the category of high-K calc-alkaline rocks and are characterized by high SiO2 content (>66 wt.%) and low MgO (average 0.69 wt.%), Mg# (average 31.49 ppm), Ni (average 2.78 ppm), and Cr (average 8.10 ppm) content, showing an affinity to I-type granite accompanied by Nb, Ta, P, and Ti depletion and negative Eu anomalies (δEu = 0.57–0.96; average 0.82). The Hf isotopic data suggest that these rocks were the product of the partial melting of juvenile crustal rocks. Notably, fractionation crystallization plays a crucial role in the process of magma emplacement. Combining our study with published ones, we proposed that the Early Cretaceous intrusive rocks in the Ulanhot area were formed in an extensional tectonic background and compactly related to the subduction of the Paleo-Pacific Ocean plate.

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