1,447 research outputs found
Quebra de dormência de sementes de Mimosa furfuracea Bentham.
Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso
Fluorescence in nanostructured fulleride films
Applied Physics Letters, 89Nanostructuring of fullerene C60 beam deposited films is achieved by electrochemical reduction in a potassium hydroxide aqueous solution. Alkali fulleride clusters are formed at the electrode, as it
is illustrated by cyclic voltammetry, x-ray diffraction, and scanning tunneling microscopy.
Fluorescence emission from fluorophore doped fullerene reduced films was investigated by
fluorescence spectroscopy and scanning near-field optical microscopy. These techniques lead to results which also fit such nanometer-sized fulleride cluster interpretation. In particular, the fluorophore fluorescence lifetime decreases as long as aggregation in the film is more effective,which occurs with the increase of film thickness
Oceanic Island forests buried by Holocene (Meghalayan) explosive eruptions: palaeobiodiversity in pre-anthropic volcanic charcoal from Faial Island (Azores, Portugal) and its palaeoecological implications
In Faial Island (Azores Archipelago, North Atlantic Ocean), charcoalified and mummified wood fossils have been
reported within late Holocene (Meghalayan) pyroclastic deposits from the Caldeira Formation. Due to their re cent age, a detailed study conveys a snapshot into Azorean palaeophytodiversity and palaeovegetation, ca. 7–5
centuries before the arrival of Portuguese settlers to the Azores Islands. Here we provide the first detailed ana tomical and taxonomical study of these wood fossils. In total, 41 samples were collected from seven localities,
mainly from a ~1200 yr BP ignimbrite. Field work revealed autochthonous and paraautochthonous assemblages,
with tree trunks in upright position. The anatomical study of the fossil woods resulted in the identification of
Juniperus brevifolia, Laurus azorica, Myrsine retusa, Morella faya, Picconia azorica, Prunus lusitanica subsp. azorica,
and Vaccinium cylindraceum. Two fossil assemblages are comparable to the proposed potential natural vegetation
(PNV) for the Azores. Surprisingly, P. lusitanica subsp. azorica was the second most abundant fossil wood suggest ing that this tree was more abundant in a recent past in Faial Island and probably in the archipelago. This is cor roborated by historical accounts, and its modern scarcity was certainly anthropically driven. Identifying Holocene
plant macrofossils is essential to properly reconstruct oceanic islands terrestrial palaeoecosystems, especially
where forests with high percentage of entomophilous taxa are underrepresented in palaeopalynological limnic
record. Further work is necessary to reconstruct Faial Island and Azores archipelago palaeovegetation which is
essential to provide an ecosystem base-line for restoration and management.info:eu-repo/semantics/publishedVersio
Hyperprolinemia as a clue in the diagnosis of a patient with psychiatric manifestations
Lately, microdeletions of the 22q region, responsible for DiGeorge syndrome or velocardiofacial syndrome, have been increasingly related to neuropsychiatric disorders including schizophrenia and bipolar disorder. These manifestations seem to be related to certain genes located in the hemideleted region such as the proline dehydrogenase (PRODH) and the catechol-o-methyltransferase (COMT) genes. We describe a teenager who started his adolescent psychiatric care presenting cognitive impairment, irritable mood and aggressive behaviour with schizophrenia-like symptoms that scored 153 in the Positive and Negative Symptoms Scale (PANSS) assessment. Worsening of symptoms when the patient was treated with valproic acid, and plasma aminoacids showing an increase in alanine and proline, suggested a mitochondrial involvement of the proline metabolic pathway. Mild dysmorphic features also suggested a possible 22q11 deletion syndrome that was confirmed. A mutation for Hyperprolinemia type I was also detected. Knowledge of the correct diagnosis was crucial for an adequate treatment.info:eu-repo/semantics/publishedVersio
Bank vole prion protein extends the use of RT-QuIC assays to detect prions in a range of inherited prion diseases
The cerebrospinal fluid (CSF) real-time quaking-induced conversion assay (RT-QuIC) is an ultrasensitive prion amyloid seeding assay for diagnosis of sporadic Creutzfeldt-Jakob disease (CJD) but several prion strains remain unexplored or resistant to conversion with commonly used recombinant prion protein (rPrP) substrates. Here, bank vole (BV) rPrP was used to study seeding by a wide range of archived post-mortem human CSF samples from cases of sporadic, acquired and various inherited prion diseases in high throughput 384-well format. BV rPrP substrate yielded positive reactions in 70/79 cases of sporadic CJD [Sensitivity 88.6% (95% CI 79.5-94.7%)], 1/2 variant CJD samples, and 9/20 samples from various inherited prion diseases; 5/57 non-prion disease control CSFs had positive reactions, yielding an overall specificity of 91.2% (95% CI 80.1-97.1%). Despite limitations of using post-mortem samples and our results' discrepancy with other studies, we demonstrated for the first time that BV rPrP is susceptible to conversion by human CSF samples containing certain prion strains not previously responsive in conventional rPrPs, thus justifying further optimisation for wider diagnostic and prognostic use
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