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1.
Epilepsy Behav ; 153: 109716, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38508103

RESUMO

OBJECTIVE: This study investigates the prevalence of pathogenic variants in the mechanistic target of rapamycin (mTOR) pathway in surgical specimens of malformations of cortical development (MCDs) and cases with negative histology. The study also aims to evaluate the predictive value of genotype-histotype findings on the surgical outcome. METHODS: The study included patients with drug-resistant focal epilepsy who underwent epilepsy surgery. Cases were selected based on histopathological diagnosis, focusing on MCDs and negative findings. We included brain tissues both as formalin-fixed, paraffin-embedded (FFPE) or fresh frozen (FF) samples. Single-molecule molecular inversion probes (smMIPs) analysis was conducted, targeting the MTOR gene in FFPE samples and 10 genes within the mTOR pathway in FF samples. Correlations between genotype-histotype and surgical outcome were examined. RESULTS: We included 78 patients for whom we obtained 28 FFPE samples and 50 FF tissues. Seventeen pathogenic variants (22 %) were identified and validated, with 13 being somatic within the MTOR gene and 4 germlines (2 DEPDC5, 1 TSC1, 1 TSC2). Pathogenic variants in mTOR pathway genes were exclusively found in FCDII and TSC cases, with a significant association between FCD type IIb and MTOR genotype (P = 0.003). Patients carrying mutations had a slightly better surgical outcome than the overall cohort, however it results not significant. The FCDII diagnosed cases more frequently had normal neuropsychological test, a higher incidence of auras, fewer multiple seizure types, lower occurrence of seizures with awareness impairment, less ictal automatisms, fewer Stereo-EEG investigations, and a longer period long-life of seizure freedom before surgery. SIGNIFICANCE: This study confirms that somatic MTOR variants represent the primary genetic alteration detected in brain specimens from FCDII/TSC cases, while germline DEPDC5, TSC1/TSC2 variants are relatively rare. Systematic screening for these mutations in surgically treated patients' brain specimens can aid histopathological diagnoses and serve as a biomarker for positive surgical outcomes. Certain clinical features associated with pathogenic variants in mTOR pathway genes may suggest a genetic etiology in FCDII patients.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Epilepsia , Malformações do Desenvolvimento Cortical do Grupo I , Malformações do Desenvolvimento Cortical , Adulto , Humanos , Epilepsia Resistente a Medicamentos/genética , Epilepsia Resistente a Medicamentos/cirurgia , Serina-Treonina Quinases TOR , Epilepsias Parciais/genética , Epilepsias Parciais/diagnóstico , Convulsões , Células Germinativas/patologia , Malformações do Desenvolvimento Cortical/patologia
2.
Int J Pharm X ; 6: 100221, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38146324

RESUMO

Synchrotron radiation offers a host of advanced properties, surpassing conventional laboratory sources with its high brightness, tunable phonon energy, photon beam coherence for advanced X-ray imaging, and a structured time profile, ideal for capturing dynamic atomic and molecular processes. However, these benefits come at the cost of operational complexity and expenses. Three decades ago, synchrotron radiation facilities, while technically open to all scientists, primarily served a limited community. Despite substantial accessibility improvements over the past two decades, synchrotron measurements still do not qualify as routine analyses. The intrinsic complexity of synchrotron science means experiments are pursued only when no alternatives suffice. In recent years, strides have been made in technology transfer offices, intermediate synchrotron-based analytical service companies, and the development of high-throughput synchrotron systems at various facilities, reshaping the perception of synchrotron science. This article investigates the practical application of synchrotron X-Ray Powder Diffraction (s-XRPD) techniques in pharmaceutical analysis. By utilizing concrete examples, we demonstrate how high-throughput systems have the potential to revolutionize s-XRPD applications in the pharmaceutical industry, rapidly generating XRPD patterns of comparable or superior quality to those obtained in state-of-the-art laboratory XRPD, all in less than 5 s. Additional cases featuring well-established pharmaceutical active ingredients (API) and excipients substantiate the concept of high throughput in pharmaceuticals, affirming data quality through structural refinements aligned with literature-derived unit cell parameters. Synchrotron data need not always be state-of-the-art to compete with lab-XRPD data. The key lies in ensuring user-friendliness, reproducibility, accessibility, cost-effectiveness, and the streamlined efforts associated with synchrotron instrumentation to remain highly competitive with their laboratory counterparts.

3.
J Pharm Sci ; 111(3): 818-824, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34890631

RESUMO

Amorphous pharmaceuticals often possess a wide range of molecular conformations and bonding arrangements. The x-ray pair distribution function (PDF) method is a powerful technique for the characterization of variations in both intra-molecular and inter-molecular packing arrangements. Here, the x-ray PDF of amorphous Indomethacin is shown to be particularly sensitive to the preferred orientations of the chlorobenzyl ring found in isomers in the crystalline state. In some cases, the chlorobenzyl ring has no preferred torsional angle in the amorphous form, while in others evidence of distinct isomer orientations are observed. Amorphous samples with no preferred torsion angles of the chlorobenzyl ring are found to favor enhanced inter-molecular hydrogen bonding, and this is reflected in the intensity of the first sharp diffraction peak. These significant variations in structure rule out amorphous Indomethacin as a possible standard for x-ray PDF measurements. At high humidity, time resolved PDF's for >40 h reveal water molecules forming hydrogen bonds with Indomethacin molecules. A simple linear hydrogen bond model indicates that water molecules in the wet amorphous form have similar hydrogen bond strengths to those found between Indomethacin dimers or chains in the dry amorphous form.


Assuntos
Indometacina , Polímeros , Ligação de Hidrogênio , Indometacina/química , Água , Difração de Raios X
4.
J Proteomics ; 224: 103818, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32434038

RESUMO

Human L-asparaginase-like protein 1 (ASRGL1) has hydrolytic activity against L-asparagine and isoaspartyl dipeptides. As an N-terminal nucleophile hydrolase family member, its activation depends on an intramolecular autoprocessing step between G167 and T168. In vitro, autoprocessing reaches only 50% completion, which restrains the activity and hampers the full understanding of the activation process. The ASRGL1 dimer interface plays a critical role in intramolecular processing, and the interactions within oligomers can offer relevant information about autoprocessing. In this work, a fully processed trimeric conformation of ASRGL1 was observed for the first time, and we combined biophysical and structural proteomics assays to characterize trimeric ASRGL1. Our analyses show that oligomerization is critical for autoprocessing, hydrolytic activity and thermal stability. The newest trimeric ASRGL1 conformation enhances protein activity and presents a melting temperature deviation of 4.33 °C in comparison to the monomeric conformation. The interaction of the third monomer in the trimeric conformation is driven by an α-helix comprising residues KVNLARLTLF (227-236).


Assuntos
Asparaginase , Autoantígenos , Humanos , Hidrólise
5.
Neuropsychologia ; 89: 364-370, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27401930

RESUMO

Laughter and smile are typical expressions of mirth and fundamental means of social communication. Despite their general interest, the current knowledge about the brain regions involved in the production of these expressions is still very limited, and the principal insights come from electrical stimulation (ES) studies in patients, in which, nevertheless, laughter or smile have been elicited very rarely. Previous studies showed that laughter is evoked by the stimulation of nodes of an emotional network encompassing the anterior cingulate, the superior frontal and basal temporal cortex. A common feature of these stimulation studies is that the facial expression was always accompanied by motor awareness and often by mirth, in line with the affective functions attributed to these regions. Little is known, in contrast, on the neural basis of the voluntary motor control of this expression. The objective of this study was to investigate the effect of ES of the frontal operculum (FO), which is considered a crucial node for the linkage of the voluntary motor system for emotional expression and limbic emotional network. We report the case of ES applied to the frontal operculum (FO) in four patients with drug-resistant focal epilepsy undergoing stereo-electroencephalographic (SEEG) implantation of intracerebral electrodes. In all patients, ES applied to the FO produced laughter or smile. Interestingly, in one patient, the production of a smiling expression was also clearly accompanied by the lack of motor awareness. Since the lack of motor awareness has been previously observed only after the stimulation of the voluntary motor network, we speculate that FO is involved in the voluntary control of facial expressions, and is placed at the interface with the emotional network, gating limbic information to the motor system.


Assuntos
Transtornos da Comunicação/terapia , Estimulação Elétrica/métodos , Potenciais Evocados/fisiologia , Lobo Frontal/fisiologia , Riso , Sorriso , Adulto , Mapeamento Encefálico , Pré-Escolar , Transtornos da Comunicação/diagnóstico por imagem , Transtornos da Comunicação/fisiopatologia , Eletroencefalografia , Feminino , Lobo Frontal/diagnóstico por imagem , Lateralidade Funcional , Humanos , Masculino , Tomógrafos Computadorizados , Adulto Jovem
6.
Nanoscale Res. Lett ; 11: p. 313, 2016.
Artigo | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib13665

RESUMO

Silver nanoparticles (AgNPs) have been broadly used as antibacterial and antiviral agents. Further, interests for green AgNP synthesis have increased in recent years and several results for AgNP biological synthesis have been reported using bacteria, fungi and plant extracts. The understanding of the role and nature of fungal proteins, their interaction with AgNPs and the subsequent stabilization of nanosilver is yet to be deeply investigated. Therefore, in an attempt to better understand biogenic AgNP stabilization with the extracellular fungal proteins and to describe these supramolecular interactions between proteins and silver nanoparticles, AgNPs, produced extracellularly by Aspergillus tubingensis-isolated as an endophytic fungus from Rizophora mangle-were characterized in order to study their physical characteristics, identify the involved proteins, and shed light into the interactions among protein-NPs by several techniques. AgNPs of around 35 nm in diameter as measured by TEM and a positive zeta potential of +8.48 mV were obtained. These AgNPs exhibited a surface plasmon resonance (SPR) band at 440 nm, indicating the nanoparticles formation, and another band at 280 nm, attributed to the electronic excitations in tryptophan, tyrosine, and/or phenylalanine residues in fungal proteins. Fungal proteins were covalently bounded to the AgNPs, mainly through S-Ag bonds due to cysteine residues (HS-) and with few N-Ag bonds from H2N-groups, as verified by Raman spectroscopy. Observed supramolecular interactions also occur by electrostatic and other protein-protein interactions. Furthermore, proteins that remain free on AgNP surface may perform hydrogen bonds with other proteins or water increasing thus the capping layer around the AgNPs and consequently expanding the hydrodynamic diameter of the particles (similar to 264 nm, measured by DLS). FTIR results enabled us to state that proteins adsorbed to the AgNPs did not suffer relevant secondary structure alteration upon their physical interaction with the AgNPs or when covalently bonded to them. Eight proteins in the AgNP dispersion were identified by mass spectrometry analyses. All these proteins are involved in metabolic pathways of the fungus and are important for carbon, phosphorous and nitrogen uptake, and for the fungal growth. Thereby, important proteins for fungi are also involved in the formation and stabilization of the biogenic AgNPs


Assuntos
Nanomedicina , Microbiologia , Bioquímica
7.
IUCrJ ; 2(Pt 5): 534-44, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26306195

RESUMO

This study focuses on the effects of the organic ligand 4-ethylresorcinol on the crystal structure of human insulin using powder X-ray crystallography. For this purpose, systematic crystallization experiments have been conducted in the presence of the organic ligand and zinc ions within the pH range 4.50-8.20, while observing crystallization behaviour around the isoelectric point of insulin. High-throughput crystal screening was performed using a laboratory X-ray diffraction system. The most representative samples were selected for synchrotron X-ray diffraction measurements, which took place at the European Synchrotron Radiation Facility (ESRF) and the Swiss Light Source (SLS). Four different crystalline polymorphs have been identified. Among these, two new phases with monoclinic symmetry have been found, which are targets for the future development of microcrystalline insulin drugs.

8.
J Neurosurg Sci ; 59(3): 237-53, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25968926

RESUMO

Cerebral cavernous malformations (CCMs) are frequently associated with a seizure disorder, and the risk of developing drug-resistant epilepsy (DRE) is substantial, especially for temporal lobe lesions. This article includes a review of the literature on the surgical treatment of epilepsy associated to CCMs in the magnetic resonance imaging (MRI) era, as well as an analysis of the Authors' experience in this field. It is concluded that microsurgery is a valuable treatment option, which may provide excellent results on seizures, with 76% of patients on average being seizure-free after surgery. Nevertheless, the optimal surgical strategy to achieve seizure control has not been clearly identified, and several attitudes have been reported in the literature. The choice of lesionectomy, associated or not to removal of surrounding hemosiderin, versus resections extended to epileptogenic cortex depends on the accurate scrutiny of several factors, which should be investigated through an adequate epileptological presurgical workup. This should include an epilepsy-oriented brain MRI study, integrated by an appropriate neurophysiological and clinical assessment, and if needed by other functional evaluations. Besides representing the optimal option in CCM-related DRE cases, microsurgery should be considered also at seizure presentation or in cases with recent-onset sporadic seizures, to protect the patient from both the possible development of drug resistance and the risk of haemorrhage.


Assuntos
Neoplasias do Sistema Nervoso Central/complicações , Neoplasias do Sistema Nervoso Central/cirurgia , Epilepsia/etiologia , Epilepsia/cirurgia , Hemangioma Cavernoso do Sistema Nervoso Central/complicações , Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Humanos , Procedimentos Neurocirúrgicos/métodos
9.
Acta Crystallogr D Biol Crystallogr ; 71(Pt 4): 819-28, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25849393

RESUMO

The primary focus of the present work is the study of the effects that two ligands and the crystallization pH have on the crystalline forms of human insulin. For this purpose, human insulin (HI) was co-crystallized with two distinct phenolic derivatives: the organic ligands meta-cresol (m-cresol) and 4-nitrophenol. The formation of polycrystalline precipitates was then followed by means of structural characterization of the individual specimens in terms of unit-cell symmetry and parameters. In both cases, two different polymorphs were identified via X-ray powder diffraction measurements, the first of hexagonal symmetry (R3 space group) at higher pH values and the second of monoclinic symmetry (space group P21) with unit-cell parameters a = 87.4282 (5), b = 70.5020 (3), c = 48.3180 (4) Å, ß = 106.8958 (4)°, the latter of which to our knowledge has never been observed before.


Assuntos
Cresóis/química , Insulinas/química , Nitrofenóis/química , Transição de Fase , Cristalização , Cristalografia por Raios X , Humanos , Modelos Moleculares , Difração de Pó , Difração de Raios X
10.
Int J Comput Assist Radiol Surg ; 9(6): 1087-97, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24748210

RESUMO

PURPOSE: StereoElectroEncephaloGraphy (SEEG) is done to identify the epileptogenic zone of the brain using several multi-lead electrodes whose positions in the brain are pre-operatively defined. Intracranial hemorrhages due to disruption of blood vessels can cause major complications of this procedure ([Formula: see text]1%). In order to increase the intervention safety, we developed and tested planning tools to assist neurosurgeons in choosing the best trajectory configuration. METHODS: An automated planning method was developed that maximizes the distance of the electrode from the vessels and avoids the sulci as entry points. The angle of the guiding screws is optimized to reduce positioning error. The planner was quantitatively and qualitatively compared with manually computed trajectories on 26 electrodes planned for three patients undergoing SEEG by four neurosurgeons. Quantitative comparison was performed computing for each trajectory using (a) the Euclidean distance from the closest vessel and (b) the incidence angle. RESULTS: Quantitative evaluation shows that automatic planned trajectories are safer in terms of distance from the closest vessel with respect to manually planned trajectories. Qualitative evaluation performed by four neurosurgeons showed that the automatically computed trajectories would have been preferred to manually computed ones in 30% of the cases and were judged good or acceptable in about 86% of the cases. A significant reduction in time required for planning was observed with the automated system (approximately 1/10). CONCLUSION: The automatic SEEG electrode planner satisfied the essential clinical requirements, by providing safe trajectories in an efficient timeframe.


Assuntos
Eletrodos Implantados , Eletroencefalografia/métodos , Epilepsia/cirurgia , Adulto , Feminino , Lobo Frontal/cirurgia , Humanos , Hemorragias Intracranianas/prevenção & controle , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos , Técnicas Estereotáxicas , Lobo Temporal/cirurgia
11.
Reprod Domest Anim ; 49(3): 409-19, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24716618

RESUMO

This study describes the reproductive parameters of Morada Nova rams, a breed of hair sheep from Brazil and with unique adaption to tropical environments. At 42 weeks of age, 15 rams were subjected to semen collection and, 1 week later, animals were slaughtered for collection of testes, epididymis and accessory sex glands. We conducted 2-D electrophoresis of seminal plasma proteins and major spots of stained gels were identified by LC-MS/MS. Total RNA was isolated from testis, epididymis and vesicular glands and subjected to qPCR. At slaughter, scrotal circumference and testicular weight were 27.5 ± 0.5 cm and 109.5 ± 6.0 g, respectively. Seminiferous tubule (ST) diameter was 188.3 ± 4.0 µm and each testis contained 1.9 ± 0.1 Sertoli cells (×10(9) ). Each Sertoli cell supported 0.1 ± 0.01 A spermatogonia, 3.0 ± 0.2 pachytene spermatocytes and 7.7 ± 0.5 round spermatids/tubule cross section. Daily sperm production reached 5.6 × 10(6)  cells/g of testis parenchyma. Testis size appeared as indicative of ST diameter and associated with epididymal measurements, as well as with the population of round spermatids and Sertoli cells/testis. Rams with heavier testes had greater daily sperm production and more Sertoli cells/testis. We detected 90.9 ± 9.6 spots per 2-D gel of seminal plasma. Major seminal proteins were identified as ram seminal vesicle proteins at 14 and 22 kDa, representing 16.2% and 12.8% of the total intensity of valid spots in the gels, respectively. Expression of both genes was greater in the vesicular glands as compared to testis and epididymis. Pixel intensity for those proteins in the 2-D gels was significantly correlated with seminal vesicle weight. This is the first description of the basic reproductive aspects of Morada Nova rams, including protein profiles of their seminal plasma. These findings will allow a better understanding of their reproductive physiology.


Assuntos
Reprodução , Proteínas de Plasma Seminal/análise , Ovinos , Espermatogênese , Testículo/anatomia & histologia , Clima Tropical , Adaptação Fisiológica/genética , Animais , Brasil , Cruzamento , Epididimo/anatomia & histologia , Expressão Gênica , Masculino , Tamanho do Órgão , Escroto/anatomia & histologia , Análise do Sêmen/veterinária , Proteínas de Plasma Seminal/genética , Contagem de Espermatozoides/veterinária
12.
Redox Biol ; 2: p.44-51, 2014.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib12581
13.
J Synchrotron Radiat ; 20(Pt 5): 667-82, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23955029

RESUMO

The Materials Science beamline at the Swiss Light Source has been operational since 2001. In late 2010, the original wiggler source was replaced with a novel insertion device, which allows unprecedented access to high photon energies from an undulator installed in a medium-energy storage ring. In order to best exploit the increased brilliance of this new source, the entire front-end and optics had to be redesigned. In this work, the upgrade of the beamline is described in detail. The tone is didactic, from which it is hoped the reader can adapt the concepts and ideas to his or her needs.

14.
Reprod Domest Anim ; 47 Suppl 6: 113-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23279478

RESUMO

The aim of the present study was to investigate the level of information on the chemical structures and relative abundances of lipids present in cat and dog oocytes by matrix-assisted laser desorption mass spectrometry (MALDI-MS). The MALDI-MS approach requires a simple analysis workflow (no lipid extraction) and few samples (two or three oocytes per analysis in this work) providing concomitant profiles of both intact phospholipids such as sphingomyelins (SM) and phosphatidylcholines (PC) as well as triacylglycerols (TAG). The lipids were detected in oocytes by MALDI using dihydroxybenzoic acid (DHB) as the matrix. The most abundant lipid present in the MS profiles of bitch and queen oocytes was a PC containing 34 carbons and one unsaturation [PC (34:1)]. Oocytes of these two species are characterized by differences in PC and TAG profiles detected qualitatively as well as by means of principal component analysis (PCA). Cat oocytes were mainly discriminated by more intense C52 and C54 TAG species and a higher number of unsaturations, indicating predominantly linoleic and oleic fatty acyl residues. Comparison of the lipid profile of bitch and queen oocytes with that of bovine oocytes revealed some similarities and also some species specificity: TAG species present in bovine oocytes were also present in bitches and queens; however, a more pronounced contribution of palmitic, stearic and oleic fatty acid residues was noticed in the lipid profile of bovine oocytes. MALDI-MS provides novel information on chemical lipid composition in canine and feline oocytes, offering a suitable tool to concomitantly monitor, in a nearly direct and simple fashion the composition of phospholipids and TAG. This detailed information is highly needed to the development of improved protocols for in vitro culture and cryopreservation of cat and dog oocytes.


Assuntos
Gatos/fisiologia , Lipídeos/química , Oócitos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/veterinária , Animais , Cães/fisiologia , Feminino , Lipídeos/fisiologia , Oócitos/fisiologia
15.
Sleep Med ; 12 Suppl 2: S33-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22136897

RESUMO

BACKGROUND: Sleep-related complex motor seizures have long been considered pathognomonic features of Nocturnal Frontal Lobe Epilepsy (NFLE). In recent years, these manifestations have also been reported to have a temporal or insular origin. METHOD: We describe 40 drug-resistant epileptic patients with complex motor seizures during sleep, submitted to presurgical stereo-EEG (SEEG) evaluation and seizure-free after surgical resection of the epileptogenic zone. RESULTS: In a significant proportion (30%) of these patients, seizures arose from extra-frontal regions, including mainly the temporal lobe and the insular cortex, but also the parietal and occipital lobes. In patients with extra-frontal epilepsy, when complex motor behaviors appeared, SEEG revealed that the ictal discharge involved the cingulate and the frontal regions. Finally, at histology, Taylor's focal cortical dysplasia (TFCD) was the most common finding (90% of patients), independent of the site of seizure onset. CONCLUSION: As previously reported by other studies, this histologic substrate may be a major determinant of sleep-related seizures in drug-resistant epileptic patients.


Assuntos
Epilepsia/fisiopatologia , Transtornos do Sono-Vigília/fisiopatologia , Adolescente , Encéfalo/patologia , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Criança , Pré-Escolar , Eletroencefalografia , Epilepsia/complicações , Epilepsia/patologia , Epilepsia/cirurgia , Feminino , Humanos , Lactente , Masculino , Polissonografia , Sono/fisiologia , Transtornos do Sono-Vigília/etiologia , Transtornos do Sono-Vigília/patologia , Transtornos do Sono-Vigília/cirurgia , Resultado do Tratamento , Adulto Jovem
16.
J Appl Microbiol ; 110(5): 1177-86, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21385290

RESUMO

AIMS: To establish the modes of action of the antagonistic fungal strain Clonostachys rosea BAFC3874 isolated from suppressive soils against Sclerotinia sclerotiorum and to determine its potential as a biocontrol agent. METHODS AND RESULTS: The antagonistic activity of C. rosea BAFC3874 was determined in vitro by dual cultures. The strain effectively antagonized S. sclerotiorum in pot-grown lettuce and soybean plants. Antifungal activity assays of C. rosea BAFC3874 grown in culture established that the strain produced antifungal compounds against S. sclerotiorum associated with secondary metabolism. High mycelial growth inhibition coincided with sclerotia production inhibition. The C. rosea strain produced a microheterogeneous mixture of peptides belonging to the peptaibiotic family. Moreover, mycoparasitism activity was observed in the dual culture. CONCLUSIONS: Clonostachys rosea strain BAFC3874 was proved to be an effective antagonist against the aggressive soil-borne pathogen S. sclerotiorum in greenhouse experiments. The main mechanisms involve peptaibiotic metabolite production and mycoparasitism activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Clonostachys rosea BAFC3874 may be a good fungal biological control agent against S. sclerotiorum. In addition, we were also able to isolate and identify peptaibols, an unusual family of compounds in this genus of fungi.


Assuntos
Antibiose , Ascomicetos/crescimento & desenvolvimento , Hypocreales/fisiologia , Microbiologia do Solo , Hypocreales/metabolismo , Lactuca/microbiologia , Micélio/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Glycine max/microbiologia
17.
J Synchrotron Radiat ; 17(6): 786-90, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20975225

RESUMO

The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both ambient and inert atmospheres. Diffraction gratings fabricated by three different techniques are considered: electroplated Au gratings both with and without the polymer mold, and Ir-coated Si gratings. The beam-induced damage is monitored by X-ray diffraction and evaluated using scanning electron microscopy.

18.
J Pharm Sci ; 98(3): 1064-74, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18729201

RESUMO

Five crystal forms of the amide-type local anesthetic S-bupivacaine hydrochloride (levobupivacaine) were prepared and characterized by means of thermal analytical methods, FTIR- and Raman-spectroscopy, powder X-ray diffractometry, and moisture sorption analysis. Commercial lots of the substance may consist of form A degrees , the thermodynamically stable form at 20 degrees C, and/or the metastable form C. Form A degrees shows a highly reversible transformation into form B (T(trs): 85.3 degrees C) with a transition enthalpy of 4.6 kJ mol(-1). The hysteresis between the experimental transition temperatures is 3.5 K, indicating a very weak kinetic control. The hydrate shows a variable water content (0.71-1.14 mol/mol) between 10% and 90% relative humidity (RH) and dehydrates to form C under dry conditions or at elevated temperatures. All anhydrous forms transform to the hydrate at and above 90% RH (25 degrees C). Form C slowly converts to form A degrees on storage and is the polymorph with the highest hygroscopicity. At higher temperatures all forms transform into form D, which is kinetically stable at 20 degrees C. It is concluded that the forms A degrees , B, and D are enantiotropically related, whereas form C shows a monotropic relationship to these forms and is metastable in the entire temperature range.


Assuntos
Anestésicos Locais/química , Bupivacaína/química , Varredura Diferencial de Calorimetria , Cristalização , Estabilidade de Medicamentos , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Termodinâmica , Termogravimetria , Água/química , Difração de Raios X
19.
Nature ; 451(7180): 805-8, 2008 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-18273014

RESUMO

The motion of atoms in a solid always responds to cooling or heating in a way that is consistent with the symmetry of the given space group of the solid to which they belong. When the atoms move, the electronic structure of the solid changes, leading to different physical properties. Therefore, the determination of where atoms are and what atoms do is a cornerstone of modern solid-state physics. However, experimental observations of atomic displacements measured as a function of temperature are very rare, because those displacements are, in almost all cases, exceedingly small. Here we show, using a combination of diffraction techniques, that the hexagonal manganites RMnO3 (where R is a rare-earth element) undergo an isostructural transition with exceptionally large atomic displacements: two orders of magnitude larger than those seen in any other magnetic material, resulting in an unusually strong magneto-elastic coupling. We follow the exact atomic displacements of all the atoms in the unit cell as a function of temperature and find consistency with theoretical predictions based on group theories. We argue that this gigantic magneto-elastic coupling in RMnO3 holds the key to the recently observed magneto-electric phenomenon in this intriguing class of materials.

20.
Micron ; 38(3): 286-90, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16797183

RESUMO

In this investigation healthy rabbit crystalline lenses were characterized by atomic force microscopy (AFM). The lenses were cut in slices with thickness with 1mm and thus, put after cortex distinct regions of nucleus and cortex for AFM examination. AFM analysis were carried out using a PicoSPM I operating in Mac Mode. We obtained topographic images of rabbit lenses and a quantitative analysis of the width and height of fibers for nucleus and cortex regions. The longitudinal section analysis of fibers in the nucleus region indicated structures with an average width of 200nm and average height of 200nm. The intershells distance was determined as 4microm. Fiber cell cross-section dimensions, longitudinal and transverse widths, could be estimated in these regions from the AFM images. Structures with average widths as small as 1.0microm are observed in the nucleus; the intershell distance is 4.0microm. In cortical regions, hexagonal structures with average longitudinal and transverse widths of 5.0mum and 3.0mum, respectively, were identified. Three-dimensional images of tissue sections with resolution on a nanometer scale were obtained. The potential of AFM analysis for characterizing healthy and pathologic lens tissues is discussed.


Assuntos
Córtex do Cristalino/ultraestrutura , Núcleo do Cristalino/ultraestrutura , Microscopia de Força Atômica , Animais , Tecido Elástico/ultraestrutura , Coelhos
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