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731.
Dariusz L. Szlachetko 《Nordic Journal of Botany》1995,15(2):173-175
Szlachetko, D. L. 1995. Two new species of the genus Pelexia (Orchidaceae, Spiranthinae) from South America. - Nord. J. Bot. 15: 173–175. Copenhagen. ISSN 0107–055X.
Pelexia sheviakii and Pelexia collocaliae are described as new species from Ecuador and Paraguay respectively. Pelexia sheviakii differs from Pelexia bonariensis and any other species related by its lip form, which is rhomboid, has no constriction, and with basal lip thickenings produced on upper surface of claw. The most characteristic features of Pelexia collocaliae are U-shaped callus at apices of petals, erect flowers, straight lateral sepals and narrow lip with two small calli near isthmus. 相似文献
Pelexia sheviakii and Pelexia collocaliae are described as new species from Ecuador and Paraguay respectively. Pelexia sheviakii differs from Pelexia bonariensis and any other species related by its lip form, which is rhomboid, has no constriction, and with basal lip thickenings produced on upper surface of claw. The most characteristic features of Pelexia collocaliae are U-shaped callus at apices of petals, erect flowers, straight lateral sepals and narrow lip with two small calli near isthmus. 相似文献
732.
Cryopreservation is widely applied to many economically important species excluding chimera plants which are problematic for long-term conservation. Their storage problems can be circumvented only by cryopreserving meristems. This study looked at the morphogenetic response of shoot tips of periclinal chimera chrysanthemum ‘Lady Orange’ and ‘Lady Salmon’, as well as the solid mutant ‘Richmond’, that were cryopreserved by encapsulation-dehydration technique. By applying 10 µM ABA in the preculture medium followed by 4-day-long dehydration treatment, the explant survival reached up to 67%. Besides the stimulation of typical single shoot recovery, cryopreservation led to direct or indirect multiple shoot formation, shoot malformation, as well as inhibited their spontaneous rooting. Microscopic analysis revealed three types of structural damages of shoot tips which can correspond with their morphogenetic response in recovery culture. No influence of cryostorage on the acclimatisation efficiency of the recovered chrysanthemums was observed. 相似文献
733.
The arterial circle of the brain,its branches and connections in selected representatives of the Antilopinae 下载免费PDF全文
Hieronim Frąckowiak Dariusz Dębiński Marcin Komosa Maciej Zdun 《Journal of morphology》2015,276(7):766-771
The arterial circle of the brain, that is, the circle of Willis, and its branches in ruminants have been chiefly described in farm animals and only in selected wild species. In view of the deficit of information about this vascular region in numerous other species of the Ruminantia, the arteries of the encephalic base were analyzed in five antelope species representing different genera of the Bovidae, Antilopinae. Specimens of the following species were examined: springbuck (Antidorcas marsupialis), blackbuck (Antilope cervicapra), dik‐dik (Madoqua kirkii), saiga (Saiga tatarica), and oribi (Ourebia ourebi). Post‐autopsy material received from domestic zoological gardens was used to inject the bilateral common carotid arteries with a stained acetone solution of vinyl superchloride. When the material was polymerized, the specimens were macerated enzymatically. The process resulted in casts of arteries of the head and encephalic base on a skeletal scaffold. The investigations revealed that the bilateral components of the arterial circle of the brain, that is, the rostral cerebral artery and caudal communicating artery, arose from the division of the intracranial segment of the internal carotid artery, which emerges from the rostral epidural rete mirabile. The extracranial segment of the internal carotid artery was obliterated. In consequence of this process, the blood reaches the brain chiefly from the maxillary artery. The research proved that the arteries of the encephalic base in the Antilopinae are most similar to the vessels described in antelopes of Tragelaphus, Taurotragus, and Boselaphus genera and small domestic ruminants. However, they are different from the arterial pattern of the encephalic base in bovines and other species classified as the Bovini. J. Morphol. 276:766–771, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
734.
Grażyna Bystrzejewska-Piotrowska Dariusz Pianka Michał A. Bazała Romuald Stęborowski José L. Manjón Pawel L. Urban 《International journal of phytoremediation》2008,10(6):503-514
This pilot study presents preliminary results on interrelations between alkali and alkaline earth elements during their transfer to mycelium and fruitbodies of saprophytic fungi. The accumulation and distribution of four elements (cesium, potassium, sodium, and calcium) was evaluated in king oyster mushroom (Pleurotus eryngii) cultivated under controlled conditions. Elemental composition of caps, stipes, and the substrate was analyzed by atomic absorption/emission spectroscopy to evaluate discrimination, concentration, and transfer factors. The transfer factors determined for all the investigated elements were different and can be put in the following order: Cs > K > Na > Ca. There has been a higher accumulation of cesium in caps than in stipes. Distribution of cesium in fruitbodies depended on the presence of other ions in the substrate. The addition of Ca2+ limited the transport of cesium and potassium from stipes to caps. Sodium and calcium were mainly accumulated in the stipes. In a control experiment, without supplementation with K+, Na+, and Ca2+, ~ 62% of the cesium present in the substrate was extracted by mycelium and transported to the fruitbodies. Possible applications of fruiting saprophytic fungi in bioremediation are discussed. 相似文献
735.
Shira Bar-Zvi Avital Lahav Dvir Harris Dariusz M. Niedzwiedzki Robert E. Blankenship Noam Adir 《BBA》2018,1859(7):544-553
The major light harvesting antenna in all cyanobacterial species is the phycobilisome (PBS). The smallest PBS identified to date is that of Acaryochloris marina (A. marina), composed of a single four-hexamer rod. We have determined the crystal structure of phycocyanin (AmPC), the major component of the A. marina PBS (AmPBS) to 2.1?Å. The basic unit of the AmPC is a heterodimer of two related subunits (α and β), and we show that the asymmetric unit contains a superposition of two α and two β isoforms, the products of the simultaneous expression of different genes. This is the first time to our knowledge that isolated proteins crystallized with such identifiable heterogeneity. We believe that the presence of the different isoforms allows the AmPBS to have a significant bathochromic shift in its fluorescence emission spectrum, allowing, in the total absence of allophycocyanin, a better overlap with absorption of the chlorophyll d-containing reaction centers. We show that this bathochromic shift exists in intact AmPBS as well as in its disassembled components, thus suggesting that AmPC can efficiently serve as the AmPBS terminal emitter. 相似文献
736.
Dariusz Suchy Krzysztof Łabuzek Grzegorz Machnik Michał Kozłowski Bogusław Okopień 《Cell biochemistry and function》2013,31(3):181-195
Diabetes mellitus is one of the most emerging diseases threatening the present world. Thus, intensive investigations are carried out to better understand the mechanisms occurring in type 1 (T1D) and 2 (T2D) diabetes, and to elaborate more potent methods to fight the disease. In this aspect, the suppressors of cytokine signalling (SOCS) are one of the most studied factors of recent years. SOCS proteins have been discovered as cytokine pathway inhibitors; however, presently, their influence seems wider. Most of the known SOCS proteins are involved in the modulation of the development of insulin resistance, β‐cell failure and eventually T1D and T2D. They are also involved in complications related with diabetes, such as retinopathy, nephropathy and cardiomyopathy. In T1D, SOCS proteins regulate β‐cell mass, mediate resistance to damaging factors and improve pancreatic islet graft survival. Regarding insulin resistance and T2D, SOCS proteins take part in mediating signals produced by diabetogenic substances and regulate insulin receptor functioning, affecting insulin sensitivity. However, not all of the present data are consistent, and thus, further studies are required. Finally, for several pharmacologically active substances of importance regarding the treatment of diabetes, SOCS‐modulating properties have already been described. Here, we review the findings of SOCS–diabetes relations of the last decade. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
737.
Lucyna Michalska Dariusz Wawrzyniak Agnieszka Szymańska-Michalak Jan Barciszewski Jerzy Boryski 《Nucleosides, nucleotides & nucleic acids》2019,38(3):218-235
We describe a simple method for the synthesis of modified dinucleosides containing pyrimidine nucleoside analogues (2’-deoxyuridine, thymidine and 5-fluoro-2’-deoxyuridine). Six different dimers with a 1,2,3-triazole linkage were obtained by azide–alkyne 1,3-dipolar cycloaddition (click reaction), starting from propargylated 2’-deoxyuridine and 5’-azido-nucleoside derivatives. Their cytotoxic activity was tested in five human cancer cell lines: cervical (HeLa), high grade gliomas (U-118?MG, U-87?MG, T98G), liver (HepG2), and normal human fibroblast cell line (MRC-5) using the sulforhodamine B (SRB) assay. The experiment showed that the obtained dimers with a 1,2,3-triazole moiety were very stable compounds, also in the physiological-like media, and had no anticancer activity. 相似文献
738.
739.
A new species of Rhetinantha from Colombian department of Antioquia is described, illustrated and placed within the key for the determination of national Rhetinantha species. The taxonomic affinity of the new entity is briefly discussed and the information about its distribution and ecology is provided. 相似文献
740.
Janina Baraniak Dariusz Korczyński Renata Kaczmarek Ewa Wasilewska 《Nucleosides, nucleotides & nucleic acids》2013,32(8):1347-1353
Abstract LCA-CPG-nucleoside 5′-O-(O-β-cyanoethyl-H-phosphonates) react with 3′-amino-2′,3′-dideoxynucleoside in the presence of iodine giving in a high yield N3′→P5′ phosphoramidate oligonucleotides. 相似文献