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1.
Front Plant Sci ; 14: 1204899, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37860260

RESUMO

Members of the genus Populus L. play an important role in the formation of forests in the northern hemisphere and are used in urban landscaping and timber production. Populus species of closely related sections show extensive hybridization. Therefore, the systematics of the genus is rather complicated, especially for poplars of hybrid origin. We aimed to assess the efficiency of application of the sex-determining region (SDR) in addition to the nuclear and chloroplast genome loci traditionally used in phylogenetic studies of poplars to investigate relationships in sections Aigeiros Duby and Tacamahaca Spach. Targeted deep sequencing of NTS 5S rDNA, ITS, DSH 2, DSH 5, DSH 8, DSH 12, DSH 29, 6, 15, 16, X18, trnG-psbK-psbI, rps2-rpoC2, rpoC2-rpoC1, as well as SDR and ARR17 gene was performed for 379 poplars. The SDR and ARR17 gene together with traditionally used multicopy and single-copy loci of nuclear and chloroplast DNA allowed us to obtain a clustering that is most consistent with poplar systematics based on morphological data and to shed light on several controversial hypotheses about the origin of the studied taxa (for example, the inexpediency of separating P. koreana, P. maximowiczii, and P. suaveolens into different species). We present a scheme of relationships between species and hybrids of sections Aigeiros and Tacamahaca based on molecular genetic, morphological, and geographical data. The geographical proximity of species and, therefore, the possibility of hybridization between them appear to be more important than the affiliation of species to the same section. We speculate that sections Aigeiros and Tacamahaca are distinguished primarily on an ecological principle (plain and mountain poplars) rather than on a genetic basis. Joint analysis of sequencing data for the SDR and chloroplast genome loci allowed us to determine the ancestors of P. × petrovskoe - P. laurifolia (female tree) × P. × canadensis (male tree), and P. × rasumovskoe - P. nigra (female tree) × P. suaveolens (male tree). Thus, the efficiency of using the SDR for the study of poplars of sections Aigeiros and Tacamahaca and the prospects of its use for the investigation of species of the genus Populus were shown.

2.
Sci Total Environ ; 706: 135999, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31841852

RESUMO

Laser ablation is an accepted cleaning technology for cultural heritage stonework. Optimized laser ablation may, however, have different side effects depending on the mineralogical composition of the stone. In the case of granitic rocks, observed side effects - colour changes, fracturing or/and mineral melting - have been attributed to laser parameter interactions with the patina to be cleaned from this complex rock with a grained texture and polymineral composition. We describe the influence of the weathering degree of a granite on its response to laser irradiation, confirming that the existence of secondary minerals in the rock influences the intensity and typology of side effects. Knowledge of this influence is of special relevance to the conservation of heritage built with Western European Variscan granites, which are already slightly weathered in quarry. Two specimens of the same Variscan granite taken from the same quarry but with different colours (suggesting different weathering rates) were subjected to nanosecond (ns) Nd:YVO4 laser irradiation, working at 355 nm (UV irradiation) under different fluences. The specimens responded very differently to laser irradiation in terms of colour changes and resistance of the main minerals to laser radiation. The existence on one of the specimens of kaolinite deposits covering feldspar grains and Fe oxyhydroxides filling fissures seemed to be the reason for the different response to laser radiation. Our findings would suggest the need, during laser interventions, to take into account - in addition to texture and porosity - the degree of weathering of this particular kind of granite, widely used in the architectural and archaeological heritage of Western Europe.

3.
Sci Total Environ ; 571: 1017-28, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27443454

RESUMO

Most of the Cultural Heritage built in NW Iberian Peninsula is made of granite which exposition to the environment leads to the formation of deposits and coatings, mainly two types: biological colonization and sulphated black crusts. Nowadays, another form of alteration derives from graffiti paints when these are applied as an act of vandalism. A deep revision needs to be addressed considering the severity of these deterioration forms on granite and the different cleaning effectiveness achieved by cleaning procedures used to remove them. The scientific literature about these topics on granite is scarcer than on sedimentary carbonate stones and marbles, but the importance of the granite in NW Iberian Peninsula Cultural Heritage claims this review centred on biological colonization, sulphated black crusts and graffiti on granite and their effectiveness of the common cleaning procedures. Furthermore, this paper carried out a review of the knowledge about those three alteration forms on granite, as well as bringing together all the major studies in the field of the granite cleaning with traditional procedures (chemical and mechanical) and with the recent developed technique based on the laser ablation. Findings concerning the effectiveness evaluation of these cleaning procedures, considering the coating extraction ability and the damage induced on the granite surface, are described. Finally, some futures research lines are pointed out.

4.
Appl Opt ; 55(17): 4706-12, 2016 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-27409029

RESUMO

In this work we implemented dynamic speckle and holographic interferometry techniques to characterize the drying process of solvent-based paint coatings. We propose a simple way to estimate drying time by measuring speckle activity and incrementally fitting experimental data through standard regression algorithms. This allowed us to predict drying time after about 20-30 min of paint application, which is fast compared to usual times required to reach the so-called tack-free state (≈2 h). In turn, we used holographic interferometry to map small thickness variations in the coating surface during drying. We also demonstrate that results obtained from both techniques correlate with each other, which allows us to improve the accuracy of the drying time estimation.

6.
Nepal J Ophthalmol ; 5(1): 69-74, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23584650

RESUMO

OBJECTIVE: To determine the prevalence of retinopathy in type 2 diabetic patients with micoalbuminuria and to evaluate the association of risk factors with prevalence of retinopathy in these patients. MATERIAL AND METHODS: A fundus examination of 137 patients suffering from type 2 diabetes mellitus with microalbuminuria was done, with direct ophthalmoscope/ binocular indirect ophthalmoscope after dilating the pupils with 1 % tropicamide eye drops. Retinal changes were graded as no retinopathy, non-proliferative retinopathy, proliferative retinopathy and maculopathy. The association of the duration of diabetes, control of diabetes, hypertension, hyperlipidemia, smoking, obesity and peripheral neuropathy was assessed with the prevalence of retinopathy in these patents. RESULTS: The mean age of the patients was 58 years (range 35 - 79 years); 62 % were females, and 49.6 % were Chinese. Diabetic retinopathy was seen in 36.5 % of the patients - non proliferative in 29.2 %, proliferative in 7.3 % and maculopathy in 5.1 % of patients. A longer duration of diabetes (p = 0.002), poor control of diabetes (p = 0.002), presence of hypertension (p = 0.03), and presence of peripheral neuropathy (p = 0.001) were significantly associated with the prevalence of retinopathy; while hyperlipidemia (p = 0.29), smoking (p = 0.43) and obesity (p = 0.43) were not associated with retinopathy. CONCLUSION: Retinopathy was seen in 36.5 % of type 2 diabetic patients with microalbuminuria; 7.3 % had proliferative retinopathy and 5.1 % maculopathy (both sight threatening changes). All diabetic patients with microalbuminuria should be screened for retinopathy so that treatment can be instituted in the required patients to prevent ocular morbidity/ blindness.


Assuntos
Albuminúria/complicações , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/epidemiologia , Adulto , Idoso , Albuminúria/epidemiologia , Estudos Transversais , Retinopatia Diabética/complicações , Retinopatia Diabética/diagnóstico , Feminino , Seguimentos , Humanos , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Oftalmoscopia , Prevalência , Estudos Retrospectivos , Fatores de Risco
7.
J Vis Exp ; (43)2010 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-20972387

RESUMO

Creation of transgenic animals is a standard approach in studying functions of a gene of interest in vivo. However, many knockout or transgenic animals are not viable in those cases where the modified gene is expressed or deleted in the whole organism. Moreover, a variety of compensatory mechanisms often make it difficult to interpret the results. The compensatory effects can be alleviated by either timing the gene expression or limiting the amount of transfected cells. The method of postnatal non-ventricular microinjection and in vivo electroporation allows targeted delivery of genes, siRNA or dye molecules directly to a small region of interest in the newborn rodent brain. In contrast to conventional ventricular injection technique, this method allows transfection of non-migratory cell types. Animals transfected by means of the method described here can be used, for example, for two-photon in vivo imaging or in electrophysiological experiments on acute brain slices.


Assuntos
Encéfalo/fisiologia , Eletroporação/métodos , Técnicas de Transferência de Genes , Microinjeções/métodos , Plasmídeos/administração & dosagem , Animais , Plasmídeos/genética , Ratos , Ratos Transgênicos
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