Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 469
Filtrar
1.
Mol Ecol ; 33(2): e17218, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38038696

RESUMO

Host-microbe interactions are increasingly recognized as important drivers of organismal health, growth, longevity and community-scale ecological processes. However, less is known about how genetic variation affects hosts' associated microbiomes and downstream phenotypes. We demonstrate that sunflower (Helianthus annuus) harbours substantial, heritable variation in microbial communities under field conditions. We show that microbial communities co-vary with heritable variation in resistance to root infection caused by the necrotrophic pathogen Sclerotinia sclerotiorum and that plants grown in autoclaved soil showed almost complete elimination of pathogen resistance. Association mapping suggests at least 59 genetic locations with effects on both microbial relative abundance and Sclerotinia resistance. Although the genetic architecture appears quantitative, we have elucidated previously unexplained genetic variation for resistance to this pathogen. We identify new targets for plant breeding and demonstrate the potential for heritable microbial associations to play important roles in defence in natural and human-altered environments.


Assuntos
Melhoramento Vegetal , Rizosfera , Humanos , Fenótipo , Plantas , Microbiologia do Solo , Raízes de Plantas/genética , Raízes de Plantas/microbiologia
2.
Pituitary ; 24(6): 943-953, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34173129

RESUMO

PURPOSE: Results are presented from 2 to 3 trials investigating oral octreotide capsules (OOC) as an alternative to injectable somatostatin receptor ligands (iSRLs) in the treatment of acromegaly. METHODS: CH-ACM-01 was an open-label trial (N = 155) and CHIASMA OPTIMAL was a double-blind placebo-controlled (DPC) trial (N = 56), both investigating OOC as maintenance therapy for patients with acromegaly who were biochemical responders receiving iSRLs. RESULTS: Baseline characteristics in both trials reflected those expected of patients with acromegaly responding to treatment and were similar between trials, despite differences in inclusion criteria. OOC demonstrated a consistent degree of biochemical response across trials, with 65% of patients in CH-ACM-01 maintaining response during the core period and 64% of patients in CHIASMA OPTIMAL at the end of the DPC. Mean insulin-like growth factor I (IGF-I) levels remained within inclusion criteria at the end of treatment in both trials. Of 110 patients entering the fixed-dose phase in CH-ACM-01, 80% maintained or improved acromegaly symptoms from baseline to the end of treatment. Over 85% of patients in both trials elected to continue into the extension phases. OOC were found to be well tolerated across both trials, and no dose-related adverse events were observed. CONCLUSIONS: OOC demonstrated remarkably consistent results for biochemical response, durability of response, and preference to continue with oral treatment across these 2 complementary landmark phase 3 trials, despite differences in the design of each. Trial registration NCT03252353 (August 2017), NCT01412424 (August 2011).


Assuntos
Acromegalia , Hormônio do Crescimento Humano , Acromegalia/tratamento farmacológico , Cápsulas , Humanos , Fator de Crescimento Insulin-Like I , Octreotida/uso terapêutico , Somatostatina
3.
J Nanosci Nanotechnol ; 19(5): 2963-2970, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30501806

RESUMO

Pure ZnO and dZnO (doped ZnO) systems of type Zn1-xMxO (M = Co, Cu, Fe and Mn) synthesised by co-precipitation method were evaluated for DSSC studies. Tween-80, a non-ionic surfactant which was used during preparation process also acted as binder for coating the nanoparticles on the FTO glass plate. In order to reduce the band gap, transition metal dopants have been incorporated into ZnO so that it changes the photo electrochemical properties. The conduction band edge minimum (CBM) potentials and valence band edge maximum (VBM) potentials were calculated. The CBM and VBM potentials varied with different dopants. The band gap were engineered such that it shifts the conduction band minimum (CBM) to less negative potential than LUMO (Lower Unoccupied Molecular Orbital) of the dye (Rhodamine B). Pure ZnO showed highest open circuit voltage (Voc) of 631.7 mV and short-circuit current density (Jsc) of 3.5031 µA/cm². In case of dZnO, 5% doping showed highest short-circuit current density and highest power conversion efficiency for all dopants (Co, Cu, Fe and Mn). Nanoparticles with remarkable morphologies influence the efficiency of dye sensitized solar cell (DSSC). The DSSC parameters such as open circuit voltage (Voc), short-circuit current density (Jsc), Fill factor (FF) and photovoltaic efficiency (η) was calculated. The effect and variation of CBM and VBM in DSSC parameter are discussed.

4.
J Nanosci Nanotechnol ; 19(2): 826-832, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30360159

RESUMO

La2CuO4 (LCO) perovskite nanoparticle was synthesized by microwave assisted combustion method and characterized using X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Fourier transformed infrared spectroscopy (FT-IR), high resolution scanning electron microscopy (HR-SEM) and energy dispersive X-ray analysis (EDX), respectively. The XRD confirmed the formation of a single orthorhombic phase. The average crystallite size of LCO samples were 39.6 nm and 46.4 nm. This LCO perovskite nanoparticle was evaluated for the conversion of methanol to formaldehyde in liquid phase batch reactor at atmospheric conditions. The conversions were studied by using different solvents like dimethyl sulfoxide (DMSO), acetonitrile, n-hexane, and temperature varying from 60 °C to 90 °C and reaction time from 1 to 4 h duration. 50 mg of catalyst, 50 mmol of DMSO, 50 mmol of methanol, temperature at 70 °C and 4 h duration was the optimized condition to achieve 100% methanol conversion and 98% selectivity of formaldehyde. The reaction pathway of methanol to formaldehyde conversion is discussed.

5.
J Nanosci Nanotechnol ; 19(6): 3388-3397, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30744766

RESUMO

Supercapacitors are perfect energy storage devices; they can be charged almost instantly and release energy over a long period. Another advantage of using supercapacitors is their multipletimes chargeable behavior with minimum degradation in performance. Herein, we report the nanoporous activated carbon based modified electrodes prepared by using phosphoric acid (PA) activation method at different temperatures (600, 700, 800, and 900 °C) using bio-waste precursor, Tamarindus indica (T. indica) fruit shell. Because of their excellent energy storage capacity, in the present work, supercapacitive behavior of the nanoporous activated carbon based modified electrode has been demonstrated and hence the electrochemical properties of the developed supercapacitor electrodes are analyzed using cyclic voltammetry, galvanostatic charge-discharge measurements, electrochemical impedance spectroscopy and cycling studies using 1 M KOH as the electrolyte. The developed supercapacitor nanoporous activated carbon materials are characterized by X-ray diffraction, functional group analysis, surface area and morphological studies.

6.
J Nanosci Nanotechnol ; 19(5): 2590-2598, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30501755

RESUMO

Cobalt oxide nanorods were successfully synthesized by a hot plate combustion method using the plant extract of Vitis vinifera. The plant extract as an alternative to toxic chemicals can be used generally as reducing and capping agents. The obtained nanorods were characterized by XRD, FT-IR, Raman, TEM, SAED, EDX, DRS, PL and VSM techniques for the structural, morphological, optical and magnetic properties. The XRD, FT-IR, Raman, EDX analysis confirmed the high purity of the sample. The TEM and SAED results showed the rod shape morphology of the sample. DRS and PL showed the band gap energy and emission at visible region. VSM showed the antiferromagnetic nature of the sample. The photocatalytic activities of the as-prepared cobalt oxide nanorods were investigated for the degradation of textile dying waste water. As per the standards of Indian pollution control board for industrial waste water let out into river bodies, the degradation reactions of waste water was found to be 250 mg/L at 150 min. Also, the same catalyst is used for the reduction of 4-nitrophenol and 4-nitroaniline using sodium borohydride as a reducing agent and it exhibits excellent reduction reaction, because of the high active surface sites. The time taken for the reduction reaction was 300 sec and 210 sec for 4-nitrophenol and 4-nitroaniline respectively. Also, the antibacterial activities towards the bacterial strains were studied and reported.


Assuntos
Antibacterianos , Nanotubos , Antibacterianos/farmacologia , Catálise , Cobalto , Óxidos , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Dis Aquat Organ ; 134(3): 175-187, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31120035

RESUMO

Farmed New Zealand Chinook salmon Oncorhynchus tshawytscha Walbaum have been found to be infected by rickettsia-like organisms (NZ-RLO). While these Gram-negative intra-cellular bacteria are closely related to Piscirickettsia salmonis, a significant pathogen for farmed salmon globally, the pathogenicity of NZ-RLO is unknown. The aim of the present study was to determine if one strain, NZ-RLO2, causes disease in Chinook salmon. Post-smolt salmon were inoculated with NZ-RLO2 by intraperitoneal injection at high, medium and low doses and observed for 30 d. All fish in the high and medium dosed groups died by the end of the study and 63% of the low dose group died within 30 d of inoculation. Necropsy revealed the fish inoculated with NZ-RLO2 had internal multifocal haemorrhages. The most consistent histological finding in fish inoculated with NZ-RLO2 was neutrophilic and necrotizing pancreatitis and steatitis with intra-cytoplasmic organisms often visible within areas of inflammation. Other histological lesions included multifocal hepatic necrosis, haematopoietic cell necrosis and splenic and renal lymphoid depletion. The presence of NZ-RLO2 within the inoculated fish was confirmed by replication in cell culture and qPCR. The results suggest NZ-RLO2 can cause disease in Chinook salmon and therefore could be a significant pathogen in farmed Chinook salmon.


Assuntos
Doenças dos Peixes , Infecções por Rickettsia/veterinária , Rickettsia , Animais , Nova Zelândia , Rickettsiales , Salmão , Virulência
8.
J Nanosci Nanotechnol ; 18(7): 4953-4962, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442679

RESUMO

Nanostructured PbZr0.52Ti0.48O3 (PZT) powder was synthesized at 500 °C-800 °C using sol-gel route. X-ray diffraction and Rietveld analysis confirmed the formation of perovskite structure. The sample heat treated at 800 °C alone showed the formation of morphotropic phase boundary with coexistence of tetragonal and rhombohedral phase. The PZT powder and PVDF were used in 0-3 connectivity to form the PZT/PVDF composite film using solvent casting method. The composite films containing 10%, 50%, 70% and 80% volume fraction of PZT in PVDF were fabricated. The XRD spectra validated that the PZT structure remains unaltered in the composites and was not affected by the presence of PVDF. The scanning electron microscopy images show good degree of dispersion of PZT in PVDF matrix and the formation of pores at higher PZT loading. The quantitative analysis of elements and their composition were confirmed from energy dispersive X-ray analysis. The optical band gap of the PVDF film is 3.3 eV and the band gap decreased with increase in volume fraction of PZT fillers. The FTIR spectra showed the bands corresponding to different phases of PVDF (α, ß, γ) and perovskite phase of PZT. The thermogravimetric analysis showed that PZT/PVDF composite films showed better thermal stability than the pure PVDF film and hydrophobicity. The dielectric constant was measured at frequency ranging from 1 Hz to 6 MHz and for temperature ranging from room temperature to 150 °C. The composite with 50% PZT filler loading shows the maximum dielectric constant at the studied frequency and temperature range with flexibility.

9.
J Nanosci Nanotechnol ; 18(8): 5367-5379, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29458588

RESUMO

Hierarchical ordered ZSM-5 zeolites were successfully synthesized by a template-free hydrothermal treatment using rice joints ash as the source of silica. The formation of hierarchical ordered ZSM-5 zeolites and its physicochemical properties were investigated systematically. The mineralogical phases, morphology, surface area and porosity, acidity and thermal stability of the synthesized hierarchical materials were investigated using XRD, FT-IR, HR-SEM, N2 adsorption-desorption (BET) analysis, NH3-TPD and TGA/DTA analysis. The excellent catalytic activity of hierarchical ordered ZSM-5 zeolites (150 °C) was revealed in the selective oxidation of toluene to the corresponding benzaldehyde with 82% conversion and 94% selectivity. The material was evaluated for the oxidation of toluene in the presence of H2O2 as the oxidizing agent and 1,4-dioxane solvent. The obtained results noted that the material was highly active, stable and can be recycled at least four times without a loss of catalytic efficiency. The crystallization was carried out in an autoclave for 5 days maintained at a temperature of 150 °C for the transformation of RJA into hierarchical ZSM-5 zeolite structure as well as to achieve high crystallinity.

10.
Ir Med J ; 116(9): 854, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37874313

Assuntos
Tensoativos , Humanos
11.
Photochem Photobiol Sci ; 16(5): 766-778, 2017 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-28349142

RESUMO

Tricobalt tetraoxide (Co3O4), a spinel-structured nanoparticle which possesses mixed oxidation states, has been synthesized via a Punica granatum (P. granatum, pomegranate) seed extract-mediated green reaction and has been investigated for its superior catalytic activity in three applications, which include (i) photodegradation of textile dye effluents (TDE) collected from the dyeing industry, Tiruppur, Tamil Nadu, India, (ii) catalytic hydrogenation of nitro-aromatic pollutants such as 4-nitrophenol and 4-nitroaniline, and (iii) antibacterial potential in biomedical applications. Prior to the application studies, the synthesized Co3O4 spinel nanoparticles (Co3O4-NPs) were characterized by well-known established techniques such as X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and Raman and FT-IR spectroscopies. We have also discussed the probable mechanism and kinetic studies of the catalytic activity of the Co3O4-NPs. Finally, we concluded that the design and development of novel, economic and green synthesis-mediated catalysts such as Co3O4-NPs can exhibit efficient catalytic activity in diverse fields, which is necessary for environmental remediation.

12.
Ecotoxicol Environ Saf ; 146: 11-18, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28781207

RESUMO

Scoping studies were designed to determine if double-crested cormorants (Phalacocorax auritus), laughing gulls (Leucophaues atricilla), homing pigeons (Columba livia) and western sandpipers (Calidris mauri) that were gavaged with a mixture of artificially weathered MC252 oil and food for either a single day or 4-5 consecutive days showed signs of oil toxicity. Where volume allowed, samples were collected for hematology, plasma protein electrophoresis, clinical chemistry and electrolytes, oxidative stress and organ weigh changes. Double-crested cormorants, laughing gulls and western sandpipers all excreted oil within 30min of dose, while pigeons regurgitated within less than one hour of dosing. There were species differences in the effectiveness of the dosing technique, with double-crested cormorants having the greatest number of responsive endpoints at the completion of the trial. Statistically significant changes in packed cell volume, white cell counts, alkaline phosphatase, alanine aminotransferase, creatine phosphokinase, gamma glutamyl transferase, uric acid, chloride, sodium, potassium, calcium, total glutathione, glutathione disulfide, reduced glutathione, spleen and liver weights were measured in double-crested cormorants. Homing pigeons had statistically significant changes in creatine phosphokinase, total glutathione, glutathione disulfide, reduced glutathione and Trolox equivalents. Laughing gulls exhibited statistically significant decreases in spleen and kidney weight, and no changes were observed in any measurement endpoints tested in western sandpipers.


Assuntos
Administração Oral , Aves/metabolismo , Fígado/metabolismo , Petróleo/toxicidade , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/análise , Aves/sangue , Contagem de Células Sanguíneas , Proteínas Sanguíneas/metabolismo , Feminino , Glutationa/metabolismo , Masculino , Taxa de Depuração Metabólica , Tamanho do Órgão/efeitos dos fármacos , Especificidade de Órgãos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/química , Tempo (Meteorologia)
13.
Ecotoxicol Environ Saf ; 142: 1-7, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28376347

RESUMO

The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and implementation of a plan for the restoration, rehabilitation, replacement or acquisition of natural resources to compensate for those injuries is accomplished through the Natural Resource Damage Assessment (NRDA) process. The NRDA process began within a week of the Deepwater Horizon oil spill, which occurred on April 20, 2010. During the spill, more than 8500 dead and impaired birds representing at least 93 avian species were collected. In addition, there were more than 3500 birds observed to be visibly oiled. While information in the literature at the time helped to identify some of the effects of oil on birds, it was not sufficient to fully characterize the nature and extent of the injuries to the thousands of live oiled birds, or to quantify those injuries in terms of effects on bird viability. As a result, the US Fish and Wildlife Service proposed various assessment activities to inform NRDA injury determination and quantification analyses associated with the Deepwater Horizon oil spill, including avian toxicity studies. The goal of these studies was to evaluate the effects of oral exposure to 1-20ml of artificially weathered Mississippi Canyon 252 oil kg bw-1 day-1 from one to 28 days or one to five applications of oil to 20% of the bird's surface area. It was thought that these exposure levels would not result in immediate or short-term mortality but might result in physiological effects that ultimately could affect avian survival, reproduction and health. These studies included oral dosing studies, an external dosing study, metabolic and flight performance studies and field-based flight studies. Results of these studies indicated changes in hematologic endpoints including formation of Heinz bodies and changes in cell counts. There were also effects on multiple organ systems, cardiac function and oxidative status. External oiling affected flight patterns and time spent during flight tasks indicating that migration may be affected by short-term repeated exposure to oil. Feather damage also resulted in increased heat loss and energetic demands. The papers in this special issue indicate that the combined effects of oil toxicity and feather effects in avian species, even in the case of relatively light oiling, can significantly affect the overall health of birds.

14.
Ecotoxicol Environ Saf ; 146: 4-10, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28559122

RESUMO

The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and implementation of a plan for the restoration, rehabilitation, replacement or acquisition of natural resources to compensate for those injuries is accomplished through the Natural Resource Damage Assessment (NRDA) process. The NRDA process began within a week of the Deepwater Horizon oil spill, which occurred on April 20, 2010. During the spill, more than 8500 dead and impaired birds representing at least 93 avian species were collected. In addition, there were more than 3500 birds observed to be visibly oiled. While information in the literature at the time helped to identify some of the effects of oil on birds, it was not sufficient to fully characterize the nature and extent of the injuries to the thousands of live oiled birds, or to quantify those injuries in terms of effects on bird viability. As a result, the US Fish and Wildlife Service proposed various assessment activities to inform NRDA injury determination and quantification analyses associated with the Deepwater Horizon oil spill, including avian toxicity studies. The goal of these studies was to evaluate the effects of oral exposure to 1-20ml of artificially weathered Mississippi Canyon 252 oil kg bw-1 day-1 from one to 28 days or one to five applications of oil to 20% of the bird's surface area. It was thought that these exposure levels would not result in immediate or short-term mortality but might result in physiological effects that ultimately could affect avian survival, reproduction and health. These studies included oral dosing studies, an external dosing study, metabolic and flight performance studies and field-based flight studies. Results of these studies indicated changes in hematologic endpoints including formation of Heinz bodies and changes in cell counts. There were also effects on multiple organ systems, cardiac function and oxidative status. External oiling affected flight patterns and time spent during flight tasks indicating that migration may be affected by short-term repeated exposure to oil. Feather damage also resulted in increased heat loss and energetic demands. The papers in this special issue indicate that the combined effects of oil toxicity and feather effects in avian species, even in the case of relatively light oiling, can significantly affect the overall health of birds.

17.
J Nanosci Nanotechnol ; 16(2): 1567-77, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27433623

RESUMO

Pure and Fe-doped ZnO nanostructures with different weight ratios (0.5, 1.0, 1.5, and 2.0 at wt% of Fe) were successfully synthesized by a facile microwave combustion method using urea as a fuel. The detailed structural characterization was performed by means of X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM). XRD patterns refined by the Rietveld method indicated that Fe-doped ZnO have a single pure phase with wurtzite structure, suggesting that Fe ions are successfully incorporated into ZnO crystal lattice by occupying Zn ionic sites. Interestingly, the morphology was found to change substantially from grains to nanoflakes and then into nanorods with the variation of Fe-content. The optical band gap estimated using DRS was found to be red-shifted from 3.220 eV for the pure ZnO nanostructures, then decreases up to 3.200 eV with increasing Fe-content. Magnetic studies showed that Fe-doped ZnO nanostructures exhibit room temperature ferromagnetism (RTFM) and the saturation magnetization attained a maximum value of 8.154 x 10(-3) emu/g for the highest Fe-content. The antibacterial activity of pure and Fe-doped ZnO nanostructures against a Gram-positive bacteria and Gram-negative bacteria was investigated. Pure ZnO and Fe-doped ZnO exhibited antibacterial activity, but it was considerably more effective in the 1.5 wt% Fe-doped ZnO nanostructures.


Assuntos
Antibacterianos , Bactérias/crescimento & desenvolvimento , Ferro , Luminescência , Nanoestruturas/química , Óxido de Zinco , Antibacterianos/química , Antibacterianos/farmacologia , Ferro/química , Ferro/farmacologia , Óxido de Zinco/química , Óxido de Zinco/farmacologia
18.
Tissue Antigens ; 84(3): 271-6, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24851745

RESUMO

Non-suppurative meningoencephalitis is a breed-restricted canine neuroinflammatory disorder affecting young greyhounds in Ireland. A genetic risk factor is suspected because of the development of disease in multiple siblings and an inability to identify a causative infectious agent. The aim of this study was to examine potential associations between dog leucocyte antigen (DLA) class II haplotype and the presence of the disease. DLA three locus haplotypes were determined in 31 dogs with non-suppurative meningoencephalitis and in 115 healthy control dogs using sequence-based typing (SBT) methods. All dogs were unrelated at the parental level. Two haplotypes (DRB1*01802/DQA1*00101/DQB1*00802 and DRB1*01501/DQA1*00601/DQB1*02201) were significantly (P = 0.0099 and 0.037) associated with the presence of meningoencephalitis, with odds ratios (95% confidence interval) of 5.531 (1.168-26.19) and 3.736 (1.446-9.652), respectively. These results confirm that there is an association between DLA class II haplotype and greyhound meningoencephalitis, suggesting an immunogenetic risk factor for the development of the disease. Greyhound meningoencephalitis may be a suitable model for human neuroinflammatory diseases with an immunogenetic component.


Assuntos
Doenças do Cão/genética , Predisposição Genética para Doença , Antígenos de Histocompatibilidade Classe II/genética , Meningoencefalite/veterinária , Alelos , Animais , Cruzamento , Cães , Haplótipos , Meningoencefalite/genética , Polimorfismo Genético , Fatores de Risco , Especificidade da Espécie
19.
Mol Ecol ; 23(4): 875-89, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24382313

RESUMO

Maintaining effective immune response is an essential factor in the survival of small populations. One of the most important immune gene regions is the highly polymorphic major histocompatibility complex (MHC). We investigated how a population bottleneck and recovery have influenced the diversity and selection in three MHC class II loci, DLA-DRB1, DLA-DQA1 and DLA-DQB1, in the Finnish wolf population. We studied the larger Russian Karelian wolf population for comparison and used 17 microsatellite markers as reference loci. The Finnish and Karelian wolf populations did not differ substantially in their MHC diversities (GST″ = 0.047, P = 0.377), but differed in neutral microsatellite diversities (GST″ = 0.148, P = 0.008). MHC allele frequency distributions in the Finnish population were more even than expected under neutrality, implying balancing selection. In addition, an excess of nonsynonymous compared to synonymous polymorphisms indicated historical balancing selection. We also studied association between helminth (Trichinella spp. and Echinococcus canadensis) prevalence and MHC diversity at allele and SNP level. MHC-heterozygous wolves were less often infected by Trichinella spp. and carriers of specific MHC alleles, SNP haplotypes and SNP alleles had less helminth infections. The associated SNP haplotypes and alleles were shared by different MHC alleles, which emphasizes the necessity of single-nucleotide-level association studies also in MHC. Here, we show that strong balancing selection has had similar effect on MHC diversities in the Finnish and Russian Karelian wolf populations despite significant genetic differentiation at neutral markers and small population size in the Finnish population.


Assuntos
Genética Populacional , Complexo Principal de Histocompatibilidade/genética , Seleção Genética , Lobos/genética , Alelos , Animais , Finlândia , Haplótipos , Helmintos/isolamento & purificação , Heterozigoto , Repetições de Microssatélites , Dados de Sequência Molecular , Polimorfismo Genético , Densidade Demográfica , Lobos/parasitologia
20.
J Nanosci Nanotechnol ; 14(3): 2317-24, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24745227

RESUMO

A novel self-assembled pure and Ce doped ZnO nano-particles (NPs) were successfully synthesized by a simple low temperature co-precipitation method. The prepared photocatalysts were characterized by X-ray diffraction (XRD), High resolution scanning electron microscopy (HR-SEM), High resolution transmission electron microscopy (HR-TEM), diffuse reflectance spectroscopy (DRS) and Photoluminescence (PL) spectroscopy. The results indicated that the prepared photocatalysts shows a novel morphology, high crystallinity, uniform size distribution, and more defects. Photocatalytic degradation (PCD) of nonylphenol, a potent endocrine disrupting chemical in aqueous medium was investigated. Higher amount of oxygen defects exhibits enhanced PCD of nonylphenol. In addition, the influence of the Ce contents on the structure, morphology, absorption, emission and photocatalytic activity of ZnO nanoparticles (NPs) were investigated systematically. The relative PCD efficiency of pure ZnO, Ce-doped ZnO NPs and commercial TiO2 (Degussa P-25) have also been discussed.


Assuntos
Césio/química , Nanoestruturas/química , Óxido de Zinco/química , Catálise , Cristalização , Luminescência , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Óptica e Fotônica , Oxigênio/química , Tamanho da Partícula , Fenóis/química , Fotoquímica , Titânio/química , Raios Ultravioleta , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA