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1.
Braz. j. biol ; 83: e249229, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339374

RESUMO

Abstract Birds are very valuable indicators of species richness and endemic patterns in a specified ecosystem, which eventually help the scientist to measure the environmental degradation. The aim of present study was to know human knowledge and attitude toward urban birds in Faisalabad city, Pakistan. The study conducted in four consecutive months: November 2019 to February 2020. Population of birds was noted from eight residential towns of Faisalabad city, data were collected through questionnaire. Faisalabad has a reasonably large population of birds and present data show that, there is a significant difference between favorite bird of residential areas and institutions. The pigeon received the most likeness in bird population among residential area residents, while the myna received the least. The most popular bird in Faisalabad institutions was the sparrow, while the least popular bird was the common myna. Bird adaptation percentage of residential areas and institutional areas of Faisalabad was the highest for parrot and sparrow respectively. People in residential areas and institutions, on the other hand, adapted least to common myna. It is concluded that people of the study area like birds and offered food and high population of birds are present in study area.


Resumo Os pássaros são indicadores muito valiosos da riqueza de espécies e padrões endêmicos em um determinado ecossistema, o que acaba ajudando o cientista a medir a degradação ambiental. O objetivo do presente estudo foi conhecer o conhecimento humano e a atitude em relação às aves urbanas na cidade de Faisalabad, Paquistão. O estudo foi conduzido em quatro meses consecutivos: novembro de 2019 a fevereiro de 2020. A população de pássaros foi observada em oito cidades residenciais da cidade de Faisalabad, os dados foram coletados por meio de questionário. Faisalabad tem uma população razoavelmente grande de pássaros, e os dados atuais mostram que há uma diferença significativa entre as aves favoritas de áreas residenciais e instituições. O pombo recebeu mais semelhanças na população de pássaros entre os residentes de áreas residenciais, enquanto o myna recebeu menos. A ave mais popular nas instituições de Faisalabad era o pardal, enquanto a ave menos popular era o myna comum. A porcentagem de adaptação de pássaros em áreas residenciais e institucionais de Faisalabad foi a mais alta para papagaios e pardais, respectivamente. As pessoas em áreas residenciais e instituições, por outro lado, se adaptaram menos ao myna comum. Conclui-se que pessoas da área de estudo como pássaros e alimentos oferecidos e alta população de pássaros estão presentes na área de estudo.


Assuntos
Humanos , Animais , Aves , Ecossistema , Paquistão , Cidades , Biodiversidade
2.
J Mech Behav Biomed Mater ; 134: 105410, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35969930

RESUMO

Yttria-stabilized zirconia (Y-SZ) has become a reliable material option to restore severely compromised teeth. Y-SZ materials are prone to low-temperature degradation (LTD), which generates a tetragonal-to-monoclinic (t-m) transformed, porous layer. We suggest that room-temperature atomic layer deposition (RT-ALD) could be used for the infiltration and deposition of nanoscale SiO2 film over this layer, creating a protective hybrid surface against further degradation by LTD. This study investigated the potential of developing a Y-SZ transformed layer under controlled conditions for the infiltration of silica using RT-ALD, aiming to develop a hybrid zirconia-silica interface, and to investigate the effect of silica deposition/infiltration via RT-ALD on the surface roughness and wettability of zirconia-based materials. Sintered specimens (14 mm × 4 mm x 2 mm) were prepared from four different Y-SZ materials (n = 40): low translucency 3 mol % Y-SZ (3Y-LT; Ceramill ZI, Amann Girrbach); high translucency 4 mol % Y-SZ (4Y-HT; Ceramill Zolid); and two high translucency 5 mol % Y-SZ (5Y-HT - Lava Esthetic, 3M; 5Y-SHT - Ceramill Zolid, FX white). Specimens were exposed to hydrothermal treatment (HTT) to develop similar depths of crystalline changes. RT-ALD was used to deposit a thin film of silica (SiO2). Surface roughness and wettability analyses were performed to investigate the effect of treatment (HTT and RT-ALD) and material on Y-SZ surface properties, and data was analyzed by two-way ANOVA and Tukey HSD (p < 0.05). RT-ALD and HTT-RT-ALD treated specimens of 3Y-LT and 5Y-HT materials were exposed to further hydrothermal aging (HA) and the surface was characterized by time-of-flight secondary ion mass spectrometry (ToF-SIMS). There was a significant interaction effect of material and treatment (HTT and RT-ALD) on roughness (p = 0.02), and surface wettability (p < 0.001). Silica deposition via RT-ALD resulted in a significant increase in surface roughness of all materials tested, while surface wettability was either improved or not changed based on the material type and HTT exposure. Nanofilms of SiO2 were successfully deposited on Y-SZ materials and infiltrated 3Y-LT zirconia.


Assuntos
Dióxido de Silício , Ítrio , Cerâmica/química , Materiais Dentários , Teste de Materiais , Dióxido de Silício/química , Propriedades de Superfície , Temperatura , Molhabilidade , Ítrio/química , Zircônio/química
3.
Chemistry ; 28(51): e202200953, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-35749651

RESUMO

An enzymatic biosensor has been developed for the determination of selenate (SeO4 2- ), in which selenate reductase (SeR) is chemically attached to a gold disk electrode by lipoic acid N-hydroxysuccinimide ester as linker, allowing the catalytic reduction of the SeO4 2- to SeO3 2- . Modification of the gold electrode was characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectroscopy (ToF-SIMS), and electrochemistry. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements were performed in different buffers for selenate determination. Under optimum conditions, the calibration curve was linear over the range 7.0-3900.0 µg L-1 with limits of detection and quantification of 4.97 and 15.56 µg L-1 , respectively. The possible interference of the relevant oxyanions SO4 2- , NO3 - , NO2 - , PO4 3- and AsO4 3- in the determination of SeO4 2- was studied. Finally, the proposed biosensor was used to determine SeO4 2- with recovery between 95.2 and 102.4 % in different real water samples.


Assuntos
Técnicas Biossensoriais , Bactérias , Técnicas Biossensoriais/métodos , Eletroquímica/métodos , Eletrodos , Ouro/química , Ácido Selênico
4.
Semin Cell Dev Biol ; 2022 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35623984

RESUMO

The generation of neuronal diversity involves temporal patterning mechanisms by which a given progenitor sequentially produces multiple cell types. Several parallels are evident between the brain development programs of Drosophila and vertebrates, such as the successive emergence of specific cell types and the use of combinations of transcription factors to specify cell fates. Furthermore, cell-extrinsic cues such as hormones and signaling pathways have also been shown to be regulatory modules of temporal patterning. Recently, transcriptomic and epigenomic studies using large single-cell sequencing datasets have provided insights into the transcriptional dynamics of neurogenesis in the Drosophila and mammalian central nervous systems. We review these commonalities in the specification of neuronal identity and highlight the conserved or convergent strategies of brain development by discussing temporal patterning mechanisms found in flies and vertebrates.

5.
Braz J Biol ; 83: e249229, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34669801

RESUMO

Birds are very valuable indicators of species richness and endemic patterns in a specified ecosystem, which eventually help the scientist to measure the environmental degradation. The aim of present study was to know human knowledge and attitude toward urban birds in Faisalabad city, Pakistan. The study conducted in four consecutive months: November 2019 to February 2020. Population of birds was noted from eight residential towns of Faisalabad city, data were collected through questionnaire. Faisalabad has a reasonably large population of birds and present data show that, there is a significant difference between favorite bird of residential areas and institutions. The pigeon received the most likeness in bird population among residential area residents, while the myna received the least. The most popular bird in Faisalabad institutions was the sparrow, while the least popular bird was the common myna. Bird adaptation percentage of residential areas and institutional areas of Faisalabad was the highest for parrot and sparrow respectively. People in residential areas and institutions, on the other hand, adapted least to common myna. It is concluded that people of the study area like birds and offered food and high population of birds are present in study area.


Assuntos
Aves , Ecossistema , Animais , Biodiversidade , Cidades , Humanos , Paquistão
6.
Faraday Discuss ; 230(0): 172-186, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-33876167

RESUMO

A proof-of-concept for the carbonation-assisted processing of ultramafic nickel ores is presented. Carbonation converts serpentine, the primary gangue or undesirable mineral, to magnesite. It prevents slime coating of fine gangue minerals on pentlandite, the main nickel-bearing mineral, during froth flotation, and improves nickel recovery and concentrate grade. Additionally, CO2 is captured and stored in the form of solid carbonates, thus removing it from the atmosphere. Microflotation experiments demonstrated improved nickel recovery (61.2 to 87.4 wt%) and concentrate grade (20.6 to 24.7 wt%) in carbonated vs. uncarbonated systems. The mechanism behind the improved nickel flotation was investigated by zeta potential measurements, optical imaging microscopy, X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. These analyses confirmed the absence of slime coating in the carbonated system under the flotation conditions tested. Finally, a preliminary techno-economic analysis was performed to evaluate the cost metrics of incorporating carbonation into nickel mineral processing.

7.
J Laryngol Otol ; 135(3): 229-233, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33641683

RESUMO

OBJECTIVE: To determine the incidence of nasolacrimal duct injury after functional endoscopic sinus surgery radiologically, using computed tomography. METHODS: Fifty patients of either sex who underwent functional endoscopic sinus surgery were evaluated for nasolacrimal duct injury by computed tomography. Computed tomography was conducted pre-operatively, and post-operatively at the end of four weeks, and nasolacrimal duct injury was analysed. RESULTS: The prevalence of nasolacrimal duct injury dehiscence was 1.16 per cent, with a similar incidence of 1.16 per cent for nasolacrimal duct injury post-operatively. However, no cases of symptomatic nasolacrimal duct injury were recorded. CONCLUSION: Computed tomography scan is an effective, non-invasive method to evaluate nasolacrimal duct injury following functional endoscopic sinus surgery, in accordance with evidence-based medicine.


Assuntos
Endoscopia/efeitos adversos , Aparelho Lacrimal/lesões , Seios Paranasais/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Doença Crônica , Feminino , Humanos , Incidência , Aparelho Lacrimal/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Prevalência , Estudos Prospectivos , Rinite/cirurgia , Sinusite/cirurgia , Adulto Jovem
8.
Cureus ; 13(11): e20038, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34993024

RESUMO

Introduction  One of the leading causes of blindness throughout the world is uveitis, which predominantly results in the feared complication of macular edema. We report the safety and efficacy of suprachoroidal injection of triamcinolone acetonide in the treatment of macular edema secondary to noninfectious uveitis.  Methodology  This prospective, nonrandomized interventional study was conducted at Layton Rahmatullah Benevolent Trust (LRBT) Eye Hospital, Lahore, from August 2019 till July 2020. All individuals older than 18 years, nonpregnant females with a central macular thickness of >320 µm were included. Those patients with uncontrolled diabetes, immunodeficiency, or any other disease mandating systemic corticosteroid use were excluded. All patients had a detailed ocular exam one week before the treatment, and 0.1 ml of triamcinolone acetonide 40 mg/ml was injected using a 30-G hollow needle into the suprachoroidal space. After the injection, an eye patch was applied and the patient was observed for three hours. All data were documented in a preformed proforma.  Results A total of 30 patients were included in the study with a mean age of 38.1 ± 9.48 years. Statistically significant differences were found between central macular thickness at presentation and at one and three months of the procedure, i.e., 569.60 ± 170.396, 266.77 ± 73.127, and 208.27 ± 37.292 µm, respectively. A similar difference was observed when comparing visual acuity at baseline to visual acuity at one and three months of the procedure (p < 0.001).  Conclusion  The current study indicates that a single dose of suprachoroidal injection of triamcinolone acetonide for the treatment of macular edema secondary to uveitis is safe and efficacious. No rise in intraocular pressure (IOP) was observed during the study period. Significant improvements in central macular thickness and visual acuity as well as tolerability and safety of the treatment were seen in our study. Further larger-scale studies are needed to ascertain the long-term benefits of the suprachoroidal triamcinolone acetonide.

9.
Cell Rep ; 31(12): 107776, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32579912

RESUMO

Glaucoma is a neurodegenerative disease that features the death of retinal ganglion cells (RGCs) in the retina, often as a result of prolonged increases in intraocular pressure. We show that preventing the formation of neuroinflammatory reactive astrocytes prevents the death of RGCs normally seen in a mouse model of glaucoma. Furthermore, we show that these spared RGCs are electrophysiologically functional and thus still have potential value for the function and regeneration of the retina. Finally, we demonstrate that the death of RGCs depends on a combination of both an injury to the neurons and the presence of reactive astrocytes, suggesting a model that may explain why reactive astrocytes are toxic only in some circumstances. Altogether, these findings highlight reactive astrocytes as drivers of RGC death in a chronic neurodegenerative disease of the eye.


Assuntos
Astrócitos/patologia , Neurônios/patologia , Neurotoxinas/toxicidade , Retina/lesões , Retina/patologia , Animais , Axônios/efeitos dos fármacos , Axônios/patologia , Morte Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Complemento C1q/metabolismo , Dendritos/efeitos dos fármacos , Dendritos/metabolismo , Modelos Animais de Doenças , Glaucoma/complicações , Glaucoma/patologia , Glaucoma/fisiopatologia , Gliose/complicações , Gliose/patologia , Gliose/fisiopatologia , Interleucina-1/metabolismo , Pressão Intraocular , Camundongos Knockout , Microesferas , Neurônios/efeitos dos fármacos , Retina/efeitos dos fármacos , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/patologia , Fator de Necrose Tumoral alfa/metabolismo
10.
Curr Microbiol ; 77(7): 1233-1244, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32123985

RESUMO

Persisters of infectious agents are capable of surviving antibiotic treatment so the emergence of these subpopulations need to be overcome. In this study, we aimed to isolate, characterize and inhibit persister subpopulation in two clinical isolates Klebsiella pneumoniae and Proteus mirabilis. Different behavior profiles between the two isolates could be observed. The results of dose-dependent killing curve revealed that 2.3% (Klebsiella pneumoniae) versus 1.3% (Proteus mirabilis) persister cells could be recovered using 500 and 30 ug/ml ciprofloxacin, respectively. Upon resuscitation, persister cells exhibited only 65% versus 30% percentage growth and 5 versus 7 times cell elongation relative to Klebsiella pneumoniae and Proteus mirabilis, respectively. The levels of persister cells to ciprofloxacin of Klebsiella pneumoniae were dramatically decreased by about 79, 92, 97 and 83% in average by pre-exposure to hyperosmotic stress, temperature, different pHs, and hydrogen peroxide, respectively, while those of Proteus mirabilis were minimally decreased with corresponding reduction percentages of about 12%, 24 & 25%, and 0%. Regarding combating persisters, Klebsiella pneumoniae showed different response as compared to Proteus mirabilis. Among the tested sugars, the highest reduction of Klebsiella pneumoniae persister cells was obtained with pre-priming with sucrose while for Proteus mirabilis persister cells, the highest reduction was obtained with pre-priming with glucose. Using sodium salicylate with ciprofloxacin could eradicate persisters of Klebsiella pneumoniae at any tested concentration while for Proteus mirabilis it caused some reduction in persister cells at certain concentrations. Complete eradication of persisters was obtained by combining silver nitrate with ciprofloxacin for each test isolate.


Assuntos
Antibacterianos/farmacologia , Klebsiella pneumoniae , Proteus mirabilis , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana/fisiologia , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/fisiologia , Testes de Sensibilidade Microbiana , Infecções por Proteus/microbiologia , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/fisiologia , Estresse Fisiológico/fisiologia
11.
J Family Med Prim Care ; 9(1): 141-146, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32110580

RESUMO

BACKGROUND: Before choosing/visiting any dental facility for their treatment, patients consider several factors. These factors may be related to the patient or service provider. The health-seeking behavior of a society defines how health services are used. AIMS: To assess the health seeking behavior of patients with premalignant lesions. MATERIAL AND METHOD: A cross sectional study using questionnaire was done among the patients who consulted in the Department of Oral Medicine and Radiology, of age 18 and above suffering from precancerous lesions. The questionnaire included 25 close-ended questions which collected information about the demographic details, oral hygiene habits, oral health issues, deleterious habits. The responses were either on dichotomous scale (yes and no) or on the frequency habits. A total of 218 subjects were included in the study. The data were analyzed using the Chi-square test. The acceptable level of significance was reduced to P < 0.05. RESULT: Slightly over 50% of study participants visited the dentist for their dental problems. Most of the participants visited dental clinic whenever needed. Maximum positive health seeking behavior is seen in fourth and fifth decade and minimum seen in second and third decade. CONCLUSION: The oral premalignant lesions have high chances of transformation into malignancies. The progression of these lesions can be prevented by stopping the progression at an early stage and thus instilling positive health seeking behavior serves as an important key to it.

12.
Kathmandu Univ Med J (KUMJ) ; 18(72): 329-332, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34165086

RESUMO

Background The global health community has emphasized the importance of reporting epidemiological data by age and sex groups in the COVID-19 pandemic. However, age and sex disaggregated data of COVID-19 cases and deaths are rarely reported. Such data are very crucial for public to make truly informed choices about their own diseases risk and also for governments for public policy response. Objective To assess age and gender difference among COVID-19 cases and deaths in Nepal. Method This is a retrospective study which uses public data on COVID-19 cases and deaths released by Ministry of Health and Population, Government of Nepal from January to November, 2020. The data analysis was carried out using SPPS software version 26. Result Nepal reported 233,452 confirmed cases and 1,566 deaths of COVID-19 from 23 January 2020 to 30 November 2020. We found statistically significant differences on COVID-19 cases by age and gender in Nepal with higher number of cases among males of economically active age groups (20-60 years). Similarly, we found significant difference in COVID-19 mortality with more death occurred among male group compared to female group and with highest number of deaths among the people of above 60 years. Furthermore, we found differences in cases and deaths among provinces. Conclusion The age and gender differences in COVID cases and deaths in Nepal indicates needs of considering age and sex groups seriously while planning for testing, case management and vaccination against COVID-19 infections in Nepal.


Assuntos
COVID-19 , Caracteres Sexuais , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Nepal/epidemiologia , Pandemias , Estudos Retrospectivos , SARS-CoV-2 , Adulto Jovem
13.
J Family Med Prim Care ; 8(9): 2983-2989, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31681679

RESUMO

Context: The people around the world are concerned about the aesthetic oral-facial structures as it is more important in interpersonal interactions and dictates vocal, physical, and emotional communication. Aims: The present study was conducted to assess the severity of malocclusion and orthodontic treatment need among 12-15-year-old school children of Patna, Eastern India. Settings and Design: A cross-sectional study design was used to assess the severity of malocclusion using Dental Aesthetic Index (DAI) index among 12-15-year-old school-going children. Methods and Material: A specially prepared and pretested format, exclusively designed for recording all the required and relevant general information and other clinical findings was used in the study. The sample size consisted of 902 children from middle schools (Government and Private) in Patna. Statistical Analysis Used: Chi-square test was done for the categorical data to compare differences between two independent groups. Data were presented as Mean ± SD and "P" value of less than 0.05 was accepted as indicating significance. Results: Around 5.3% had a DAI score of ≤25 which signifies that there is "no abnormality or may have minor malocclusion"; 15.3% had a DAI score of 26-30 which signifies that there is "definite malocclusion"; 6% had a DAI score of 31-35 which signifies that there is "severe malocclusion" and 4% had a DAI score of ≥36 which signifies that there is "very severe or handicapping malocclusion". The finding was more commonly seen among 14 years age group. Conclusions: It can be concluded from the present study that the prevalence of malocclusion is reasonable high in this part of the region, and it is very important to bring in more awareness at the school level as primary prevention can be the most effective tool in control this menace.

14.
J Endod ; 45(12): 1513-1521, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31594670

RESUMO

INTRODUCTION: The purpose of this study was to evaluate the effect of chitosan-hydroxyapatite precursor (C-HA) nanocomplex conditioning on the chemical modifications at the tricalcium silicate sealer-dentin interface using time-of-flight secondary ion mass spectrometry. METHODS: Dentin slabs from human premolar root dentin were prepared, demineralized, and randomly distributed between control and C-HA nanocomplex conditioned groups. Tricalcium silicate sealer was applied, and the slabs were allowed to set in 100% humidity for 10 days. The cross-sectional area was exposed, and the sealer-dentin interface was characterized for chemical/ultrastructural evaluation with time-of-flight secondary ion mass spectrometry and transmission electron microscopy, respectively. RESULTS: Chemical analysis revealed the presence of an ion-rich layer constituted of abundant phosphates (PO2-, PO3-, and PO4-), hydroxide (OH-), and chitosan fragments (C2H4NO-, C3H4NO2-, C2H5O2+, C2H6NO+, C4H6NO2+, C5H6NO+, and C5H5O2+) on the dentin surface at the sealer-dentin interface and subsurface dentin after conditioning with C-HA nanocomplexes. In contrast, a decreased interfacial presence of calcium (Ca+) and calcium phosphates (CaPO2+, CaPO3+, CaPO4+, and Ca2PO3+) and the absence of phosphate fragments in the control were noted. Ultrastructural evaluation showed an interfacial layer (<1 µm) with interrupted mineral aggregates in the controls as opposed to a continuous (5 µm) mineral layer formation on the conditioned dentin. CONCLUSIONS: C-HA nanocomplex conditioning of dentin before tricalcium silicate sealer application resulted in a chemically modified dentin substrate with an ion-rich layer consisting of phosphate, calcium, calcium phosphates, and chitosan that chemically modified the dentin surface/subsurface.


Assuntos
Quitosana , Dentina , Durapatita , Materiais Restauradores do Canal Radicular , Compostos de Cálcio , Quitosana/farmacologia , Dentina/efeitos dos fármacos , Durapatita/farmacologia , Humanos , Teste de Materiais , Silicatos , Espectrometria de Massa de Íon Secundário
15.
Proc Natl Acad Sci U S A ; 116(23): 11508-11517, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31097585

RESUMO

Opsins form a family of light-activated, retinal-dependent, G protein-coupled receptors (GPCRs) that serve a multitude of visual and nonvisual functions. Opsin 3 (OPN3 or encephalopsin), initially identified in the brain, remains one of the few members of the mammalian opsin family with unknown function and ambiguous light absorption properties. We recently discovered that OPN3 is highly expressed in human epidermal melanocytes (HEMs)-the skin cells that produce melanin. The melanin pigment is a critical defense against ultraviolet radiation (UVR), and its production is mediated by the Gαs-coupled melanocortin 1 receptor (MC1R). The physiological function and light sensitivity of OPN3 in melanocytes are yet to be determined. Here, we show that in HEMs, OPN3 acts as a negative regulator of melanin production by modulating the signaling of MC1R. OPN3 negatively regulates the cyclic adenosine monophosphate (cAMP) response evoked by MC1R via activation of the Gαi subunit of G proteins, thus decreasing cellular melanin levels. In addition to their functional relationship, OPN3 and MC1R colocalize at both the plasma membrane and in intracellular structures, and can form a physical complex. Remarkably, OPN3 can bind retinal, but does not mediate light-induced signaling in melanocytes. Our results identify a function for OPN3 in the regulation of the melanogenic pathway in epidermal melanocytes; we have revealed a light-independent function for the poorly characterized OPN3 and a pathway that greatly expands our understanding of melanocyte and skin physiology.


Assuntos
Epiderme/metabolismo , Melanócitos/metabolismo , Pigmentação/fisiologia , Receptor Tipo 1 de Melanocortina/metabolismo , Opsinas de Bastonetes/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/metabolismo , AMP Cíclico/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Células HeLa , Humanos , Melaninas/metabolismo , Transdução de Sinais/fisiologia , Pele/metabolismo
16.
J Comp Neurol ; 527(1): 259-269, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29675855

RESUMO

In many species, neurons are unevenly distributed across the retina, leading to nonuniform analysis of specific visual features at certain locations in visual space. In recent years, the mouse has emerged as a premiere model for probing visual system function, development, and disease. Thus, achieving a detailed understanding of mouse visual circuit architecture is of paramount importance. The general belief is that mice possess a relatively even topographic distribution of retinal ganglion cells (RGCs)-the output neurons of the eye. However, mouse RGCs include ∼30 subtypes; each responds best to a specific feature in the visual scene and conveys that information to central targets. Given the crucial role of RGCs and the prominence of the mouse as a model, we asked how different RGC subtypes are distributed across the retina. We targeted and filled individual fluorescently tagged RGC subtypes from across the retinal surface and evaluated the dendritic arbor extent and soma size of each cell according to its specific retinotopic position. Three prominent RGC subtypes: On-Off direction selective RGCs, object-motion-sensitive RGCs, and a specialized subclass of nonimage-forming RGCs each had marked topographic variations in their dendritic arbor sizes. Moreover, the pattern of variation was distinct for each RGC subtype. Thus, there is increasing evidence that the mouse retina encodes visual space in a region-specific manner. As a consequence, some visual features are sampled far more densely at certain retinal locations than others. These findings have implications for central visual processing, perception, and behavior in this prominent model species.


Assuntos
Células Ganglionares da Retina/citologia , Animais , Feminino , Masculino , Camundongos , Retina/citologia
17.
Cell Rep ; 25(8): 2017-2026.e3, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30463000

RESUMO

Sensory processing can be tuned by a neuron's integration area, the types of inputs, and the proportion and number of connections with those inputs. Integration areas often vary topographically to sample space differentially across regions. Here, we highlight two visual circuits in which topographic changes in the postsynaptic retinal ganglion cell (RGC) dendritic territories and their presynaptic bipolar cell (BC) axonal territories are either matched or unmatched. Despite this difference, in both circuits, the proportion of inputs from each BC type, i.e., synaptic convergence between specific BCs and RGCs, remained constant across varying dendritic territory sizes. Furthermore, synapse density between BCs and RGCs was invariant across topography. Our results demonstrate a wiring design, likely engaging homotypic axonal tiling of BCs, that ensures consistency in synaptic convergence between specific BC types onto their target RGCs while enabling independent regulation of pre- and postsynaptic territory sizes and synapse number between cell pairs.


Assuntos
Células Ganglionares da Retina/metabolismo , Sinapses/metabolismo , Animais , Axônios/metabolismo , Dendritos/metabolismo , Glutamatos/metabolismo , Camundongos , Células Bipolares da Retina/metabolismo , Peixe-Zebra/metabolismo
18.
J Endod ; 44(11): 1714-1719, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30266468

RESUMO

INTRODUCTION: SmearOFF (Vista Dental Products, Racine, WI) is an irrigation solution containing chlorhexidine (CHX), EDTA, and a surfactant. This study examined the chemical interaction of SmearOFF with sodium hypochlorite (NaOCl) on the dentin surface, specifically the formation of precipitate and/or parachloroanaline (PCA). METHODS: Dentin blocks prepared from human maxillary molars were mounted in resin. Dentinal tubules were exposed in a perpendicular orientation using an ultracryomicrotome. The blocks were divided into 2 groups: the CHX group, irrigation with 6% NaOCl, 17% EDTA, 6% NaOCl, and 2% CHX, and the SmearOFF group, irrigation with 6% NaOCl and SmearOFF. The dentin surface was analyzed with time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy to determine the formation of precipitate or/and PCA on the surface of dentin. RESULTS: Precipitation with PCA and occlusion of the dentinal tubules were noted on the dentin surface in the CHX group. No precipitate and no PCA were detected on the surface of dentin in the SmearOFF group. CONCLUSIONS: Interaction of SmearOFF with NaOCl on the dentin surface did not result in the formation of precipitate or PCA.


Assuntos
Clorexidina/química , Dentina/metabolismo , Dentina/patologia , Irrigantes do Canal Radicular/química , Hipoclorito de Sódio/química , Compostos de Anilina/metabolismo , Precipitação Química , Clorexidina/efeitos adversos , Interações Medicamentosas , Ácido Edético , Humanos , Microscopia Eletrônica de Varredura , Irrigantes do Canal Radicular/efeitos adversos , Hipoclorito de Sódio/efeitos adversos , Espectrometria de Massa de Íon Secundário , Propriedades de Superfície , Tensoativos
19.
Sci Rep ; 7(1): 14515, 2017 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-29109454

RESUMO

We provide the first continuous Indian Summer Monsoon (ISM) climate record for the higher Himalayas (Kedarnath, India) by analyzing a 14C-dated peat sequence covering the last ~8000 years, with ~50 years temporal resolution. The ISM variability inferred using various proxies reveal striking similarity with the Greenland ice core (GISP2) temperature record and rapid denitrification changes recorded in the sediments off Peru. The Kedarnath record provides compelling evidence for a reorganization of the global climate system taking place at ~5.5 ka BP possibly after sea level stabilization and the advent of inter-annual climate variability governed by the modern ENSO phenomenon. The ISM record also captures warm-wet and cold-dry conditions during the Medieval Climate Anomaly and Little Ice Age, respectively.

20.
J Sci Food Agric ; 97(14): 4780-4789, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28369913

RESUMO

BACKGROUND: Accumulation of lead (Pb) in agricultural soils has become a major factor for reduced crop yields and poses serious threats to humans consuming agricultural products. The present study investigated the effects of KNO3 seed priming (0 and 0.5% KNO3 ) on growth of maize (Zea mays L.) seedlings exposed to Pb toxicity (0, 1300 and 2550 mg kg-1 Pb). RESULTS: Pb exposure markedly reduced the growth of maize seedlings and resulted in higher Pb accumulation in roots than shoots. Pretreatment of seeds with KNO3 significantly improved the germination percentage and increased physiological indices. A stimulating effect of KNO3 seed priming was also observed on pigments (chlorophyll a, b, total chlorophyll and carotenoid contents) of Pb-stressed plants. Low translocation of Pb from roots to shoots caused an increased accumulation of total free amino acids and higher activities of catalase, peroxidase, superoxide dismutase and ascorbate peroxidase in roots as compared to shoot, which were further enhanced by exogenous KNO3 supply to prevent Pb toxicity. CONCLUSION: Maize accumulates more Pb in roots than shoot at early growth stages. Priming of seeds with KNO3 prevents Pb toxicity, which may be exploited to improve seedling establishment in crop species grown under Pb contaminated soils. © 2017 Society of Chemical Industry.


Assuntos
Chumbo/toxicidade , Nitratos/farmacologia , Compostos de Potássio/farmacologia , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Zea mays/efeitos dos fármacos , Antioxidantes/análise , Antioxidantes/metabolismo , Carotenoides/análise , Clorofila/análise , Contaminação de Alimentos/prevenção & controle , Germinação/efeitos dos fármacos , Chumbo/análise , Raízes de Plantas/química , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Poluentes do Solo/análise , Zea mays/crescimento & desenvolvimento
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