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1.
Life (Basel) ; 13(11)2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-38004355

RESUMEN

This paper is devoted to the study of the flora of silica-scaled chrysophytes in water bodies of the steppe zone of the Southern Urals (Russia). Twenty-four taxa were identified via scanning and transmission electron microscopy, twenty of which are representatives of the genus Mallomonas Perty, while four are species of the genus Synura Ehrenberg. In the course of the study, a species new to science from the genus Mallomonas, M. baturinae sp. nov., was described. This species belongs to the section Papillosae. The stomatocyst of M. doignonii was described. For the first time in Russia and for the third time since description, M. phasma and M. solea-ferrea var. irregularis were reported in the studied area. Here, their extended description is provided with illustrations of their scales in detail. Some rare taxa for the flora of Russia have been identified: M. doignonii, M. pillula f. exannulata, and M. pillula f. valdiviana. One taxon of the genus Mallomonas has not been identified to a species level and is probably a taxon new to science.

2.
Plants (Basel) ; 11(23)2022 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-36501404

RESUMEN

A new species of green coccoid algae, Mychonastes hindakii sp. nov., was isolated from the River Moscow (Russia, Moscow). The taxon is described using morphological and molecular methods. Mychonastes hindakii sp. nov. belongs to the group of species of the genus Mychonastes with spherical single cells joined with mucilaginous, irregularly shaped stalks. A comparison of ITS2 rDNA sequences and its secondary structures combined with the compensatory base changes approach confirms the separation between Mychonastes hindakii and other species of the genus. Mychonastes hindakii sp. nov. represents a cryptic species that can only be reliably identified using molecular data.

3.
Life (Basel) ; 12(10)2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-36295046

RESUMEN

The present paper focuses on the silica-scaled chrysophytes from two tropical islands: Con Son (Con Dao Archipelago) and Phu Quoc, located in Viet Nam. Electron microscopy revealed fifty-seven taxa, of which forty-one belong to the genus Mallomonas. The others are species of the genera Synura (5), Paraphysomonas (8), Spiniferomonas (1), Chrysosphaerella (1) and Lepidochromonas (1). This is the first report of the genus Lepidochromonas from Viet Nam. In addition, two species from the genus Paraphysomonas are reported for the first time in the country. Six taxa from the genus Mallomonas and five taxa from the genus Paraphysomonas were not identifiable to the lower rank and may represent new species for science. The overall diversity of the silica-scaled chrysophytes of the islands is very high. A number of rare taxa endemic to Southeast Asia were found.

4.
J Phycol ; 58(6): 789-803, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36054495

RESUMEN

A new cyanobacterial species of Aliinostoc, A. vietnamicum sp. nov., is recorded in the tropical forest soil from the Cát Tiên National Park, Vietnam. The analysis is based on morphological characters, 16S rDNA phylogeny, ITS secondary structure, and fatty acid composition analysis. Aliinostoc vietnamicum differed from the other species of the genus by the size and shape of vegetative cells, size of akinetes and heterocytes, and presence of granular polyphosphate inclusions in vegetative cells. The evolutionary distance matrix based on the 16S rRNA gene shared 96.2-98.2% similarities with other Aliinostoc sequences. The phylogeny inferred by maximum likelihood and Bayesian inference placed A. vietnamicum in the Aliinostoc clade, within the Nostocaceae. For the first time, fatty acid composition analysis was obtained for a member of the genus Aliinostoc with cultivation time experiments. α-linolenic (27.54-37.75%), palmitic (13.87-22.65%), and stearic (10.08-20.27%) acids were the dominant fatty acids when cultured during the exponential growth phase, as well as during stationary. This is the first finding of a strain with such a high content of stearic acid among cyanobacteria with Nostoc-like morphology.


Asunto(s)
Nostoc , Suelo , Filogenia , ARN Ribosómico 16S/genética , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Teorema de Bayes , Ácidos Grasos , Vietnam , Análisis de Secuencia de ADN , Nostoc/genética
5.
PhytoKeys ; 183: 95-105, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34744474

RESUMEN

A new cymbelloid diatom species from the genus Cymbopleura (Krammer) Krammer is described on the basis of molecular and morphological investigations. Cymbopleuranatellia Glushchenko, Kulikovskiy & Kociolek, sp. nov. is, on the basis of results with molecular data, close to C.naviculiformis (Auerswald ex Heiberg) Krammer. The two species differ both by molecular distance and morphological features. Morphologically, C.natellia sp. nov. is compared with several other species in the genus. This work is a pioneer investigation of cymbelloid taxa using molecular tool from Transbaikal area.

6.
PhytoKeys ; 187: 129-140, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35068971

RESUMEN

A new monoraphid diatom species Achnanthidiumgladius sp. nov. is described from Indonesia. The description is based on molecular data (18SV4), morphological analysis and comparison with similar species. According to molecular data, Achnanthidiumgladius sp. nov. is closely related to Achnanthidiumminutissimum. Morphologically, the new species differs from similar species by the absence of a fascia on raphe valve, cell size, and striae density and pattern. The new species is only known from the type locality in Indonesia. Comparison with close related species is given.

7.
Heart Rhythm ; 18(2): 221-228, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32911052

RESUMEN

BACKGROUND: Cardiac rhythm and conduction disorders are common in patients with epilepsy and are presumably one of the leading causes of sudden unexpected death. There are only a few published reports on ictal cardiac arrhythmias detected by continuous monitoring, and the majority had a small sample size. OBJECTIVE: The aim of this study was to evaluate the frequency and type of cardiac arrhythmias recorded by an implantable loop recorder in patients with drug-resistant epilepsy. METHODS: We implanted a subcutaneous loop recorder to 193 patients with drug-resistant epilepsy. Automatic triggers to initiate cardiac rhythm recording were cardiac pauses of >3 seconds and any episodes of bradycardia (≤45 beats/min) or tachycardia (≥150 beats/min). Patients/relatives were instructed to begin peri-ictal rhythm recording by using an external activator device. The follow-up duration was 36 months, with scheduled follow-up visits every 3 months. RESULTS: A total of 6494 electrocardiogram traces were recorded during the median follow-up of 36 months (interquartile range 3-36 months). Ictal heart rhythm and rate changes were detected in 143 patients (74%). The most common finding was ictal sinus tachycardia (66.8%). Sinus bradycardia was observed in 13 patients (6.7%). Three patients had clinically relevant cardiac pauses of >6 seconds, requiring permanent pacemaker implantation. Five patients (2.6%) died suddenly. CONCLUSION: Ictal heart rhythm and rate changes occur in most of the patients with drug-resistant epilepsy. Clinically relevant cardiac events, related to ictal and postictal periods, are rare. No potentially malignant arrhythmias were detected in patients who died suddenly during the preceding follow-up period.


Asunto(s)
Arritmias Cardíacas/etiología , Electrocardiografía Ambulatoria/métodos , Electrocardiografía/métodos , Frecuencia Cardíaca/fisiología , Muerte Súbita e Inesperada en la Epilepsia/epidemiología , Adolescente , Adulto , Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Federación de Rusia/epidemiología , Tasa de Supervivencia/tendencias , Factores de Tiempo , Adulto Joven
8.
Harmful Algae ; 98: 101889, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-33129449

RESUMEN

Raphidiopsis raciborskii is a freshwater, potentially toxigenic cyanobacterium, originally described as a tropical species that is spreading to northern regions over several decades. The ability of R. raciborskii to produce cyanotoxins - in particular the alkaloid cylindrospermopsin (CYN), which is toxic to humans and animals - is of serious concern. The first appearance of R. raciborskii in Russia was noted in Lake Nero in the summer of 2010. This is the northernmost (57°N) recorded case of the simultaneous presence of R. raciborskii and detection of CYN. In this study, the data from long-term monitoring of the R. raciborskii population, temperature and light conditions in Lake Nero were explored. CYN and cyr/aoa genes present in environmental samples were examined using HPLC/MS-MS and PCR analysis. A R. raciborskii strain (R104) was isolated and its morphology, toxigenicity and phylogeography were studied. It is supposed that the trigger factor for the strong development of R. raciborskii in Lake Nero in summer 2010 may have been the relatively high water temperature, reaching 29-30 °C. Strain R. raciborskii R104 has straight trichomes and can produce akinetes, making it morphologically similar to European strains. Phylogeographic analysis based on nifH gene and 16S-23S rRNA ITS1 sequences showed that the Russian strain R104 grouped together with R. raciborskii strains isolated from Portugal, France, Germany and Hungary. The Russian strain R104 does not contain cyrA and cyrB genes, meaning that it - like all European strains - cannot produce CYN. Thus, while recent invasion of R. raciborskii into Lake Nero has occurred, morphological, genetic, and toxicological data supported the spreading of this cyanobacterium from other European lakes. Detection of CYN and cyr/aoa genes in environmental samples indicated the cyanobacterium Aphanizomenon gracile as a likely producer of CYN in Lake Nero. The article also discusses data on the global biogeography of R. raciborskii. Genetic similarity between R. raciborskii strains isolated from very remote continents might be related to the ancient origin of the cyanobacterium inhabiting the united continents of Laurasia and Gondwana, rather than comparably recent transoceanic exchange between R. raciborskii populations.


Asunto(s)
Lagos , Animales , Aphanizomenon , Cylindrospermopsis , Francia , Filogeografía , Portugal , Federación de Rusia
9.
J Phycol ; 56(6): 1601-1613, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32871027

RESUMEN

A new diatom genus, Gogorevia, is described on the basis of an integrated molecular and morphological investigation. Two species are described from Vietnam: the generitype, G. rinatii sp. nov., and G. ovalis sp. nov. These species share many morphological features with Achnanthes exigua and allied taxa that were previously transferred to the genera Achnanthidium or Lemnicola. Our current molecular investigation shows that Gogorevia is distinct and phylogenetically removed from the above-mentioned genera. Morphologically, Gogorevia differs from Achnanthidium and Lemnicola by the shape of the valves, possessing uniseriate striae, raphe morphology, and the presence of an evident sternum. The recently described species Lemnicola uniseriata is transferred to Gogorevia on the basis that it possesses the same morphological features and phylogenetic position as other members of the genus.


Asunto(s)
Diatomeas , Filogenia , Vietnam
10.
Brain Sci ; 10(9)2020 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-32947812

RESUMEN

Endothelial dysfunction is recognized as one of the leading factors in the pathogenesis of diseases of the central nervous system of various etiologies. Numerous studies have shown the role of hyperhomocysteinemia in the development of endothelial dysfunction and the prothrombogenic state. The most important condition in the development of multiple sclerosis (MS) is a dysregulation of the blood-brain barrier (BBB) and transendothelial leukocyte migration. It has been proven that homocysteine also contributes to the damage of neurons by the mechanism of excitotoxicity and the induction of the apoptosis of neurons. These processes can be one of the factors of neurodegenerative brain damage, which plays a leading role in the progression of MS. This review describes the pleiotropic effect of homocysteine on these processes and its role in MS pathogenesis.

11.
J Phycol ; 55(1): 173-185, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30379324

RESUMEN

Type material of Navicula kotschyi was studied, and this species was transferred to Dorofeyukea gen. nov. as D. kotschyi comb. nov. Dorofeyukea was described on the basis of DNA sequence and morphological data. Additional species assigned to this genus that were previously included in Navicula include: D. ancisa comb. nov., D. grimmei comb. nov., D. ivatoensis comb. nov., D. orangiana comb. nov., D. rostellata comb. nov. & stat. nov., D. savannahiana comb. nov., D. tenuipunctata comb. nov., and D. texana comb. nov. All Dorofeyukea species share the same morphological features, including having a narrow stauroid fascia surrounded by 1-3 irregularly shortened striae, uniseriate, and weakly radiate striae, circular, or rectangular puncta in the striae that are covered internally by dome-shaped hymenes, presence of a pseudoseptum at each apex and absence of septa. Partial DNA sequences of SSU and rbcL loci show Dorofeuykae belongs to the clade of stauroneioid diatoms together with Stauroneis, Prestauroneis, Craticula, Karayevia, Madinithidium, Fistulifera, Parlibellus, and, possibly, Schizostauron. A new species from the monoraphid genus Madinithidium, M. vietnamica sp. nov., was described based on valve and chloroplast morphology as well as DNA sequence data.


Asunto(s)
Diatomeas , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN
12.
J Eukaryot Microbiol ; 65(1): 38-47, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28508432

RESUMEN

A complex of closely related Mallomonas taxa belonging to the section Papillosae, M. kalinae Rezácová and M. rasilis Dürrschmidt, has been studied in detail by molecular and morphometric methods. Our investigations uncovered the existence of a new species found in water bodies in Vietnam, which we describe here as Mallomonas furtiva sp. nov. This taxon is morphologically very similar to M. kalinae, from which it differs by minute, but statistically significant morphological differences on the structure of silica scales. Indeed, the principal component analysis of morphological traits measured on silica scales significantly separates all three species in the complex. Mallomonas kalinae and M. furtiva differ by number of papillae on the shield and the dome, as well as by the scale sizes. Likewise, Mallomonas rasilis and M. furtiva are primarily differentiated by the absence of submarginal anterior ribs on silica scales of the former species. Phylogenetic analyses showed that Mallomonas furtiva is closely related to M. kalinae, with which it formed a highly supported lineage. Distribution patterns of all three studied taxa are further discussed.


Asunto(s)
Microbiota , Estramenopilos/clasificación , Proteínas Algáceas/análisis , ADN de Algas/análisis , ADN Ribosómico/análisis , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Filogenia , Estramenopilos/genética , Estramenopilos/ultraestructura , Vietnam , Humedales
13.
Sci Rep ; 5: 17115, 2015 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-26596906

RESUMEN

The genus Simonsenia is reviewed and S. aveniformis described as new for science by light and electron microscopy. The new species originated from estuarine environments in southern Iberia (Atlantic coast) and was isolated into culture. In LM, Simonsenia resembles Nitzschia, with bridges (fibulae) beneath the raphe, which is marginal. It is only electron microscope (EM) examination that reveals the true structure of the raphe system, which consists of a raphe canal raised on a keel (wing), supported by rib like braces (fenestral bars) and tube-like portulae; between the portulae the keel is perforated by open windows (fenestrae). Based on the presence of portulae and a fenestrated keel, Simonsenia has been proposed to be intermediate between Bacillariaceae and Surirellaceae. However, an rbcL phylogeny revealed that Simonsenia belongs firmly in the Bacillariaceae, with which it shares a similar chloroplast arrangement, rather than in the Surirellaceae. Lack of homology between the surirelloid and simonsenioid keels is reflected in subtle differences in the morphology and ontogeny of the portulae and fenestrae. The diversity of Simonsenia has probably been underestimated, particularly in the marine environment.


Asunto(s)
Diatomeas/ultraestructura , Diatomeas/genética , Genes del Cloroplasto , Marcadores Genéticos , Filogenia , Análisis de Secuencia de ADN
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