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1.
Mol Cell ; 69(6): 938-952.e6, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29547722

RESUMO

We report an unanticipated system of joint regulation by cyclin-dependent kinase (CDK) and mitogen-activated protein kinase (MAPK), involving collaborative multi-site phosphorylation of a single substrate. In budding yeast, the protein Ste5 controls signaling through a G1 arrest pathway. Upon cell-cycle entry, CDK inhibits Ste5 via multiple phosphorylation sites, disrupting its membrane association. Using quantitative time-lapse microscopy, we examined Ste5 membrane recruitment dynamics at different cell-cycle stages. Surprisingly, in S phase, where Ste5 recruitment should be blocked, we observed an initial recruitment followed by a steep drop-off. This delayed inhibition revealed a requirement for both CDK activity and negative feedback from the pathway MAPK Fus3. Mutagenesis, mass spectrometry, and electrophoretic analyses suggest that the CDK and MAPK modify shared sites, which are most extensively phosphorylated when both kinases are active and able to bind their docking sites on Ste5. Such collaborative phosphorylation can broaden regulatory inputs and diversify output dynamics of signaling pathways.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/genética , Sítios de Ligação , Pontos de Checagem do Ciclo Celular , Membrana Celular/enzimologia , Quinases Ciclina-Dependentes/genética , Ciclinas/genética , Ciclinas/metabolismo , Cinética , Proteínas Quinases Ativadas por Mitógeno/genética , Fosforilação , Ligação Proteica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética , Especificidade por Substrato
2.
EMBO Rep ; 22(11): e52476, 2021 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-34558777

RESUMO

Changing environmental cues lead to the adjustment of cellular physiology by phosphorylation signaling networks that typically center around kinases as active effectors and phosphatases as antagonistic elements. Here, we report a signaling mechanism that reverses this principle. Using the hyperosmotic stress response in Saccharomyces cerevisiae as a model system, we find that a phosphatase-driven mechanism causes induction of phosphorylation. The key activating step that triggers this phospho-proteomic response is the Endosulfine-mediated inhibition of protein phosphatase 2A-Cdc55 (PP2ACdc55 ), while we do not observe concurrent kinase activation. In fact, many of the stress-induced phosphorylation sites appear to be direct substrates of the phosphatase, rendering PP2ACdc55 the main downstream effector of a signaling response that operates in parallel and independent of the well-established kinase-centric stress signaling pathways. This response affects multiple cellular processes and is required for stress survival. Our results demonstrate how a phosphatase can assume the role of active downstream effectors during signaling and allow re-evaluating the impact of phosphatases on shaping the phosphorylome.


Assuntos
Proteínas de Saccharomyces cerevisiae , Proteínas de Ciclo Celular/metabolismo , Fosforilação , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Proteômica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
3.
Plant Dis ; 107(7): 2061-2069, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36510429

RESUMO

Sweet potato virus disease (SPVD) is a global constraint to sweetpotato (Ipomoea batatas) production, especially under intensive cultivation in the humid tropics such as East Africa. The objectives of this study were to develop a precision SPVD phenotyping protocol, to find new SPVD-resistant genotypes, and to standardize the first stages of screening for SPVD resistance. The first part of the protocol was based on enzyme-linked immunosorbent assay results for sweet potato chlorotic stunt virus (SPCSV) and sweet potato virus C (SPVC) with adjustments to a negative control (uninfected clone Tanzania) and was performed on a prebreeding population (VZ08) comprising 455 clones and 27 check clones graft inoculated under screenhouse conditions. The second part included field studies with 52 selected clones for SPCSV resistance from VZ08 and 8 checks. In screenhouse conditions, the resistant and susceptible check clones performed as expected; 63 clones from VZ08 exhibited lower relative absorbance values for SPCSV and SPVC than inoculated check Tanzania. Field experiments confirmed SPVD resistance of several clones selected by relative absorbance values (nine resistant clones in two locations; that is, 17.3% of the screenhouse selection), supporting the reliability of our method for SPVD-resistance selection. Two clones were promising, exhibiting high storage root yields of 28.7 to 34.9 t ha-1 and SPVD resistance, based on the proposed selection procedure. This modified serological analysis for SPVD-resistance phenotyping might lead to more efficient development of resistant varieties by reducing costs and time at early stages, and provide solid data for marker-assisted selection with a quantitative tool for classifying resistance.[Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.


Assuntos
Ipomoea batatas , Potyvirus , Viroses , Viroses/classificação , Ipomoea batatas/virologia , Potyvirus/classificação , Potyvirus/genética , Tanzânia , Resistência à Doença
4.
J Cell Mol Med ; 26(17): 4666-4677, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35916437

RESUMO

Heroin, a semisynthetic opioid drug synthesized from morphine, is the 3,6-diacetyl ester of morphine (diacetylmorphine). The post-mortem diagnosis of heroin-related death could be an issue and usually rely on a combination of investigations, including the autopsy, histological and toxicological analysis. We conducted the present study to evaluate the correlation between the heroin concentration in biological fluids (peripheral blood, bile and urine) and the post-mortem anti-6-MAM antibody expression in various tissues (brain, heart, lung, liver and kidney) using immunohistochemical staining. A quantitative analysis of the immunohistochemical reaction was carried out. 45 cases of heroin-related death investigated at the Forensic Pathology Institutes of the University of Rome, Foggia and Pisa were included. The control group was composed of 15 cases of death due to other causes, without brain lesions and negative toxicological analysis for drugs. We found a positive immunohistochemical reaction in different organs and it was related to the timing of heroin metabolization. No reaction was found in the control group. Our findings show that immunohistochemistry can be a valuable tool for the post-mortem diagnosis of acute heroin abuse. A better understanding of the timing of heroin's metabolism can be useful in the forensic field and for future therapeutic applications.


Assuntos
Dependência de Heroína , Heroína , Anticorpos , Heroína/análise , Heroína/metabolismo , Dependência de Heroína/diagnóstico , Humanos , Derivados da Morfina/análise , Derivados da Morfina/metabolismo
5.
Int J Mol Sci ; 23(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36077384

RESUMO

The newly developed prediction models, having the aim to classify Romanian honey samples by associating ATR-FTIR spectral data and the statistical method, PLS-DA, led to reliable differentiations among the samples, in terms of botanical and geographical origin and harvesting year. Based on this approach, 105 out of 109 honey samples were correctly attributed, leading to true positive rates of 95% and 97% accuracy for the harvesting differentiation model. For the botanical origin classification, 83% of the investigated samples were correctly predicted, when four honey varieties were simultaneously discriminated. The geographical assessment was achieved in a percentage of 91% for the Transylvanian samples and 85% of those produced in other regions, with overall accuracy of 88% in the cross-validation procedure. The signals, based on which the best classification models were achieved, allowed the identification of the most significant compounds for each performed discrimination.


Assuntos
Mel , Análise Discriminante , Geografia , Mel/análise , Análise Espectral
6.
Theor Appl Genet ; 133(1): 23-36, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31595335

RESUMO

KEY MESSAGE: ß-Carotene content in sweetpotato is associated with the Orange and phytoene synthase genes; due to physical linkage of phytoene synthase with sucrose synthase, ß-carotene and starch content are negatively correlated. In populations depending on sweetpotato for food security, starch is an important source of calories, while ß-carotene is an important source of provitamin A. The negative association between the two traits contributes to the low nutritional quality of sweetpotato consumed, especially in sub-Saharan Africa. Using a biparental mapping population of 315 F1 progeny generated from a cross between an orange-fleshed and a non-orange-fleshed sweetpotato variety, we identified two major quantitative trait loci (QTL) on linkage group (LG) three (LG3) and twelve (LG12) affecting starch, ß-carotene, and their correlated traits, dry matter and flesh color. Analysis of parental haplotypes indicated that these two regions acted pleiotropically to reduce starch content and increase ß-carotene in genotypes carrying the orange-fleshed parental haplotype at the LG3 locus. Phytoene synthase and sucrose synthase, the rate-limiting and linked genes located within the QTL on LG3 involved in the carotenoid and starch biosynthesis, respectively, were differentially expressed in Beauregard versus Tanzania storage roots. The Orange gene, the molecular switch for chromoplast biogenesis, located within the QTL on LG12 while not differentially expressed was expressed in developing roots of the parental genotypes. We conclude that these two QTL regions act together in a cis and trans manner to inhibit starch biosynthesis in amyloplasts and enhance chromoplast biogenesis, carotenoid biosynthesis, and accumulation in orange-fleshed sweetpotato. Understanding the genetic basis of this negative association between starch and ß-carotene will inform future sweetpotato breeding strategies targeting sweetpotato for food and nutritional security.


Assuntos
Regulação da Expressão Gênica de Plantas , Ipomoea batatas/genética , Poliploidia , Locos de Características Quantitativas/genética , Amido/metabolismo , beta Caroteno/metabolismo , Alelos , Meio Ambiente , Estudos de Associação Genética , Fenótipo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Característica Quantitativa Herdável
7.
Cell Commun Signal ; 17(1): 66, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208443

RESUMO

Modern quantitative mass spectrometry (MS)-based proteomics enables researchers to unravel signaling networks by monitoring proteome-wide cellular responses to different stimuli. MS-based analysis of signaling systems usually requires an integration of multiple quantitative MS experiments, which remains challenging, given that the overlap between these datasets is not necessarily comprehensive. In a previous study we analyzed the impact of the yeast mitogen-activated protein kinase (MAPK) Hog1 on the hyperosmotic stress-affected phosphorylome. Using a combination of a series of hyperosmotic stress and kinase inhibition experiments, we identified a broad range of direct and indirect substrates of the MAPK. Here we re-evaluate this extensive MS dataset and demonstrate that a combined analysis based on two software packages, MaxQuant and Proteome Discoverer, increases the coverage of Hog1-target proteins by 30%. Using protein-protein proximity assays we show that the majority of new targets gained by this analysis are indeed Hog1-interactors. Additionally, kinetic profiles indicate differential trends of Hog1-dependent versus Hog1-independent phosphorylation sites. Our findings highlight a previously unrecognized interconnection between Hog1 signaling and the RAM signaling network, as well as sphingolipid homeostasis.


Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteômica/métodos , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais , Software , Células HeLa , Humanos , Fosforilação , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismo
9.
J Proteome Res ; 14(12): 5048-62, 2015 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-26535604

RESUMO

The HOP2-MND1 heterodimer is essential for meiotic homologous recombination in plants and other eukaryotes and promotes the repair of DNA double-strand breaks. We investigated the conformational flexibility of HOP2-MND1, important for understanding the mechanistic details of the heterodimer, with chemical cross-linking in combination with mass spectrometry (XL-MS). The final XL-MS workflow encompassed the use of complementary cross-linkers, quenching, digestion, size exclusion enrichment, and HCD-based LC-MS/MS detection prior to data evaluation. We applied two different homobifunctional amine-reactive cross-linkers (DSS and BS(2)G) and one zero-length heterobifunctional cross-linker (EDC). Cross-linked peptides of four biological replicates were analyzed prior to 3D structure prediction by protein threading and protein-protein docking for cross-link-guided molecular modeling. Miniaturization of the size-exclusion enrichment step reduced the required starting material, led to a high amount of cross-linked peptides, and allowed the analysis of replicates. The major interaction site of HOP2-MND1 was identified in the central coiled-coil domains, and an open colinear parallel arrangement of HOP2 and MND1 within the complex was predicted. Moreover, flexibility of the C-terminal capping helices of both complex partners was observed, suggesting the coexistence of a closed complex conformation in solution.


Assuntos
Proteínas de Arabidopsis/química , Fosfotransferases/química , Proteínas de Arabidopsis/metabolismo , Carbodi-Imidas/química , Cromatografia em Gel , Reagentes de Ligações Cruzadas/química , Modelos Moleculares , Complexos Multiproteicos/química , Fosfotransferases/metabolismo , Conformação Proteica , Multimerização Proteica , Succinimidas/química , Espectrometria de Massas em Tandem , Fluxo de Trabalho
10.
Food Chem ; 458: 140245, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38954957

RESUMO

The present study proposes the development of new wine recognition models based on Artificial Intelligence (AI) applied to the mid-level data fusion of 1H NMR and Raman data. In this regard, a supervised machine learning method, namely Support Vector Machines (SVMs), was applied for classifying wine samples with respect to the cultivar, vintage, and geographical origin. Because the association between the two data sources generated an input space with a high dimensionality, a feature selection algorithm was employed to identify the most relevant discriminant markers for each wine classification criterion, before SVM modeling. The proposed data processing strategy allowed the classification of the wine sample set with accuracies up to 100% in both cross-validation and on an independent test set and highlighted the efficiency of 1H NMR and Raman data fusion as opposed to the use of a single-source data for differentiating wine concerning the cultivar and vintage.

11.
Foods ; 13(4)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38397509

RESUMO

Nowadays, in people's perceptions, the return to roots in all aspects of life is an increasing temptation. This tendency has also been observed in the medical field, despite the availability of high-level medical services with many years of research, expertise, and trials. Equilibrium is found in the combination of the two tendencies through the inclusion of the scientific experience with the advantages and benefits provided by nature. It is well accepted that the nutritional and medicinal properties of honey are closely related to the botanical origin of the plants at the base of honey production. Despite this, people perceive honey as a natural and subsequently a simple product from a chemical point of view. In reality, honey is a very complex matrix containing more than 200 compounds having a high degree of compositional variability as function of its origin. Therefore, when discussing the nutritional and medicinal properties of honey, the importance of the geographical origin and its link to the honey's composition, due to potential emerging contaminants such as Rare Earth Elements (REEs), should also be considered. This work offers a critical view on the use of honey as a natural superfood, in a direct relationship with its botanical and geographical origin.

12.
J Forensic Leg Med ; 103: 102662, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38484484

RESUMO

Volatile Solvents Abuse (VSA) poses major health risks, especially for young people and those living in precarious socio-economic conditions. Such substances can in fact bring about psychoactive effects such as euphoria, and even lead to sudden death from cardiac arrhythmias, respiratory depression, myocardial infarction, laryngospasm, encephalopathy, and rhabdomyolysis. The present case report is centered around a 23-year-old man who died in prison due to inhalation of a cooker gas mixture (n-butane, propane, and isobutane) inside a plastic bag. External examination and autopsy showed non-specific signs of asphyxia associated with edema and brain swelling. Histological signs of early myocardial damage and hypoxic-ischemic injury (HII) were highlighted in the brain and cerebellum, as well as activated macrophages and anthracotic-like material in the lungs. Toxicological investigations revealed the presence of propane, isobutane and n-butane in liquids and biological samples. Besides the cardiotoxic effect, there was an asphyctic component due to the plastic bag that may have facilitated death. The assessment of cerebral HII and cardiopulmonary damage in acute cases is very important to prove death by butane inhalation. In the forensic field, it may be useful to shed more light on intoxications, deaths, and butane encephalopathies, as the latter can be mistaken for a hypoxic-ischemic encephalopathy.


Assuntos
Butanos , Morte Súbita , Humanos , Masculino , Adulto Jovem , Asfixia/etiologia , Asfixia/patologia , Encéfalo/patologia , Edema Encefálico/patologia , Butanos/intoxicação , Butanos/efeitos adversos , Morte Súbita/etiologia , Hipóxia-Isquemia Encefálica/etiologia , Hipóxia-Isquemia Encefálica/patologia , Abuso de Inalantes/complicações , Pulmão/patologia , Miocárdio/patologia , Propano/intoxicação , Propano/efeitos adversos
13.
Virus Res ; 339: 199276, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38006786

RESUMO

Breeders have made important efforts to develop genotypes able to resist virus attacks in sweetpotato, a major crop providing food security and poverty alleviation to smallholder farmers in many regions of Sub-Saharan Africa, Asia and Latin America. However, a lack of accurate objective quantitative methods for this selection target in sweetpotato prevents a consistent and extensive assessment of large breeding populations. In this study, an approach to characterize and classify resistance in sweetpotato was established by assessing total yield loss and virus load after the infection of the three most common viruses (SPFMV, SPCSV, SPLCV). Twelve sweetpotato genotypes with contrasting reactions to virus infection were grown in the field under three different treatments: pre-infected by the three viruses, un-infected and protected from re-infection, and un-infected but exposed to natural infection. Virus loads were assessed using ELISA, (RT-)qPCR, and loop-mediated isothermal amplification (LAMP) methods, and also through multispectral reflectance and canopy temperature collected using an unmanned aerial vehicle. Total yield reduction compared to control and the arithmetic sum of (RT-)qPCR relative expression ratios were used to classify genotypes into four categories: resistant, tolerant, susceptible, and sensitives. Using 14 remote sensing predictors, machine learning algorithms were trained to classify all plots under the said categories. The study found that remotely sensed predictors were effective in discriminating the different virus response categories. The results suggest that using machine learning and remotely sensed data, further complemented by fast and sensitive LAMP assays to confirm results of predicted classifications could be used as a high throughput approach to support virus resistance phenotyping in sweetpotato breeding.


Assuntos
Ipomoea batatas , Potyvirus , Viroses , Ipomoea batatas/genética , Doenças das Plantas/genética , Melhoramento Vegetal , Potyvirus/genética
14.
Cleft Palate Craniofac J ; 50(6): e105-10, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22906393

RESUMO

Objectives : Dermatoglyphic patterns make good material for genetic studies because they remain stable throughout life. Given that the primary palate, lip, and dermal ridges develop during the same period of intrauterine life, the genetic message contained in the genome can be deciphered during this period and is reflected by dermatoglyphics. This study was undertaken to compare the dermatoglyphic patterns in subjects with clefts and controls and both their parents to study the genetic etiology. Methods : A total of 294 subjects (48 cleft subjects and 50 healthy controls with both their parents) were selected. Finger and palm prints of all were recorded using the ink method. Results : Increased frequency of loops and arches and low mean total ridge count was observed in cleft subjects. Increased frequency of loops and arches with decreased frequency of whorls, mean total ridge count, and atd angle of right hand was found in parents of cleft group as compared with the parents of the controls. Conclusion : Dermatoglyphic patterns have considerable variances. They can be used to study genetic etiology and as an educational tool for genetic counseling.


Assuntos
Fenda Labial , Fissura Palatina , Fenda Labial/genética , Fissura Palatina/genética , Dermatoglifia , Dedos , Humanos , Pais
15.
Med Leg J ; 91(3): 128-135, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37293768

RESUMO

Cannabis is the most widely used illicit psychoactive substance in the world. In recent years, in many European Union countries, there has been a decriminalisation of the use and personal possession of cannabis for recreational purposes. There has been a spread of medical cannabis, as well as marketing of cannabis products at low concentrations of delta-9-tetrahydrocannabinol (Delta-9-THC), the major chemical to which cannabis owes its psychotropic effect. The percentage limit of this substance, only recently set by the European Court of Justice, must be distinguished from the "doping dose" of Delta-9-THC, namely, the dose which causes psychotropic effect in the consumer. Our study analyses and summarises the regulations in the countries of the European Union on the penalisation of recreational cannabis, the legalisation of medical cannabis and limits on percentage of THC imposed locally. Based on the analysis of a recent judgment of the Italian Supreme Court of Cassation, we discuss the importance of the role of the forensic toxicologist in the scientific definition of "doping dose". The distinction between the doping dose of THC and the percentage of THC contained in the marketed cannabis product is vital when establishing fair punishment in the event of a crime.


Assuntos
Cannabis , Maconha Medicinal , Humanos , Cannabis/química , Dronabinol/análise , União Europeia
16.
Food Chem X ; 20: 100902, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38144738

RESUMO

The present work aimed to test the efficiency of FT-Raman spectroscopy for fruit spirits discrimination by developing differentiation models based on two approaches, namely a supervised statistical method (Partial Least Squares Discriminant Analysis), and a Machine Learning technique (Support Vector Machines). For this purpose, a data set comprising 86 Romanian distillate samples was used, which aimed to be differentiated in terms of the raw material used for production (plum, apple, pear and grape) and county of origin (Cluj, Satu Mare and Salaj). Eight distinct preprocessing methods (autoscale, mean center, variance scaling, smoothing, 1st derivative, 2nd derivative, standard normal variate and Pareto) followed by a feature selection step were applied to identify the meaningful input data based on which the most efficient classification models can be constructed. Both types of models led to accuracy scores greater than 90% in differentiating the distillate samples in terms of geographical and botanical origin.

17.
Dalton Trans ; 52(4): 902-908, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36504121

RESUMO

In this research work, we present a study on time-sequenced plasma-enhanced atomic layer deposition (PE-ALD) processes towards the achievement of high-quality α-MoO3 thin films which are suitable for exfoliation. In particular, a conventional precursor injection method along with a boosted precursor delivery approach are discussed and analysed. In the latter, the proposed gas supply mechanism ensures a large number of deposited Mo atoms per unit of time, which, along with a proper thermal energy, leads to high-quality and oriented orthorhombic α-MoO3 films. The proposed boosted approach is also compared with post growth annealing steps, resulting in more effective achievement of a highly oriented orthorhombic α-MoO3 phase and less time consumption.


Assuntos
Temperatura Alta , Molibdênio
18.
Artigo em Inglês | MEDLINE | ID: mdl-36767179

RESUMO

The COVID-19 pandemic gives us the largest telework experiment ever conducted globally, that will most likely leave visible and lasting marks on the organization of the labor market in the future. The purpose of this approach is to investigate the wellbeing from the social and emotional perspective of the individual, considering relevant relational communication, emotional dimension, work intensity, organization, autonomy and work-life balance, customized in the context of teleworking. The information was collected using a semi-structured questionnaire. The wellbeing assessment was performed based on the correlation analysis and the regression analysis. The results of the studies reveal that the existence of adequate communication and work-life balance ensure the wellbeing of telework employees, while the increase in work intensity degrades it. Furthermore, good communication moderates the relationship between organizational skills and wellbeing. The comparative analysis of wellbeing in relation to the explanatory variables considered by including the gender and age perspective reveals the existence of different configurations, with specific signs and statistical meanings.


Assuntos
COVID-19 , Teletrabalho , Humanos , COVID-19/epidemiologia , Pandemias , Comunicação , Emoções
19.
Nanomaterials (Basel) ; 14(1)2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38202552

RESUMO

MoS2 is a two-dimensional layered transition metal dichalcogenide with unique electronic and optical properties. The fabrication of ultrathin MoS2 is vitally important, since interlayer interactions in its ultrathin varieties will become thickness-dependent, providing thickness-governed tunability and diverse applications of those properties. Unlike with a number of studies that have reported detailed information on direct bandgap emission from MoS2 monolayers, reliable experimental evidence for thickness-induced evolution or transformation of the indirect bandgap remains scarce. Here, the sulfurization of MoO3 thin films with nominal thicknesses of 30 nm, 5 nm and 3 nm was performed. All sulfurized samples were examined at room temperature with spectroscopic ellipsometry and photoluminescence spectroscopy to obtain information about their dielectric function and edge emission spectra. This investigation unveiled an indirect-to-indirect crossover between the transitions, associated with two different Λ and K valleys of the MoS2 conduction band, by thinning its thickness down to a few layers.

20.
J Contemp Dent Pract ; 13(5): 618-22, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23250163

RESUMO

BACKGROUND AND OBJECTIVE: The elongated styloid process may produce characteristic head and neck pain syndromes, commonly known as Eagle's syndrome. An awareness of this syndrome is important to all health practitioners involved in the diagnosis and treatment of neck and head pain. It has been estimated that 2 to 28% of the general adult population has radiographic appearance of elongated styloid process. The objective of the study was to assess the elongation of styloid process on digital panoramic radiographs and to evaluate the prevalence of elongation according to age, sex and types. RESULTS: Elongated styloid process was seen in 107 subjects out of 300 patients who were aged between 10 and 70 years old. Our study revealed that as age increased elongation of styloid process increased with female predominance. Type 1 elongation was most common than the other types of elongation. We also found that left styloids were elongated than the right with bilateral elongation. CONCLUSION: Panoramic radiographs can show a correct picture of elongated styloid process which can confirm the diagnosis and can thus help avoid misinterpretation of the symptoms as tonsillar pain or pain of dental, pharyngeal or muscular origin and hence panoramic radiography is economical and the best imaging modality to view the elongation of styloid process.


Assuntos
Ossificação Heterotópica/diagnóstico por imagem , Radiografia Dentária Digital/métodos , Radiografia Panorâmica/métodos , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Diagnóstico Diferencial , Dor Facial/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cervicalgia/diagnóstico , Ossificação Heterotópica/classificação , Ossificação Heterotópica/patologia , Doenças Faríngeas/diagnóstico , Fatores Sexuais , Osso Temporal/anormalidades , Osso Temporal/diagnóstico por imagem , Osso Temporal/patologia , Tonsilite/diagnóstico , Adulto Jovem
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