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1.
An Acad Bras Cienc ; 96(2): e20231336, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38747801

RESUMO

The disease coronavirus COVID-19 has been the cause of millions of deaths worldwide. Among the proteins of SARS-CoV-2, non-structural protein 12 (NSP12) plays a key role during COVID infection and is part of the RNA-dependent RNA polymerase complex. The monitoring of NSP12 polymorphisms is extremely important for the design of new antiviral drugs and monitoring of viral evolution. This study analyzed the NSP12 mutations detected in circulating SARS-CoV-2 during the years 2020 to 2022 in the population of the city of Manaus, Amazonas, Brazil. The most frequent mutations found were P323L and G671S. Reports in the literature indicate that these mutations are related to transmissibility efficiency, which may have contributed to the extremely high numbers of cases in this location. In addition, two mutations described here (E796D and R914K) are close and have RMSD that is similar to the mutations M794V and N911K, which have been described in the literature as influential on the performance of the NSP12 enzyme. These data demonstrate the need to monitor the emergence of new mutations in NSP12 in order to better understand their consequences for the treatments currently used and in the design of new drugs.


Assuntos
COVID-19 , Mutação , SARS-CoV-2 , Proteínas não Estruturais Virais , SARS-CoV-2/genética , Brasil , Proteínas não Estruturais Virais/genética , COVID-19/virologia , COVID-19/transmissão , Mutação/genética , Humanos , Simulação por Computador
2.
Microb Biotechnol ; 17(1): e14258, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37017414

RESUMO

Complex polymers represent a challenge for remediating environmental pollution and an opportunity for microbial-catalysed conversion to generate valorized chemicals. Members of the genus Streptomyces are of interest because of their potential use in biotechnological applications. Their versatility makes them excellent sources of biocatalysts for environmentally responsible bioconversion, as they have a broad substrate range and are active over a wide range of pH and temperature. Most Streptomyces studies have focused on the isolation of strains, recombinant work and enzyme characterization for evaluating their potential for biotechnological application. This review discusses reports of Streptomyces-based technologies for use in the textile and pulp-milling industry and describes the challenges and recent advances aimed at achieving better biodegradation methods featuring these microbial catalysts. The principal points to be discussed are (1) Streptomyces' enzymes for use in dye decolorization and lignocellulosic biodegradation, (2) biotechnological processes for textile and pulp and paper waste treatment and (3) challenges and advances for textile and pulp and paper effluent treatment.


Assuntos
Streptomyces , Indústria Têxtil , Streptomyces/genética , Biotecnologia , Catálise , Biodegradação Ambiental , Resíduos Industriais/análise
3.
Ecol Evol ; 13(3): e9885, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36937069

RESUMO

The advancement and availability of innovative animal biotelemetry and genomic technologies are improving our understanding of how the movements of individuals influence gene flow within and between populations and ultimately drive evolutionary and ecological processes. There is a growing body of work that is integrating what were once disparate fields of biology, and here, we reviewed the published literature up until January 2023 (139 papers) to better understand the drivers of this research and how it is improving our knowledge of animal biology. The review showed that the predominant drivers for this research were as follows: (1) understanding how individual-based movements affect animal populations, (2) analyzing the relationship between genetic relatedness and social structuring, and (3) studying how the landscape affects the flow of genes, and how this is impacted by environmental change. However, there was a divergence between taxa as to the most prevalent research aim and the methodologies applied. We also found that after 2010 there was an increase in studies that integrated the two data types using innovative statistical techniques instead of analyzing the data independently using traditional statistics from the respective fields. This new approach greatly improved our understanding of the link between the individual, the population, and the environment and is being used to better conserve and manage species. We discuss the challenges and limitations, as well as the potential for growth and diversification of this research approach. The paper provides a guide for researchers who wish to consider applying these disparate disciplines and advance the field.

4.
J Pediatr Intensive Care ; 11(4): 327-334, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36388076

RESUMO

The aim of the current study is to evaluate the use of an enteral clonidine transition for the prevention or management of dexmedetomidine withdrawal symptoms in critically ill children not exposed to other continuous infusion sedative agents. A retrospective, single-center study was conducted in patients ≤ 18 years of age admitted to the pediatric intensive care unit who received a continuous infusion of dexmedetomidine for ≥ 24 hours and who were prescribed enteral clonidine within 72 hours of dexmedetomidine discontinuation. Predefined withdrawal terminology was established to assess for hypertension, tachycardia, agitation, tremors, and decreased sleep. A total of 105 patients were included and received enteral clonidine for prevention or management of dexmedetomidine withdrawal symptoms, with 13 patients (12.4%) requiring a taper modification to manage withdrawal symptoms. The median duration of dexmedetomidine infusion was 120.5 hours (95.5, 143.5) and median peak infusion rate was 1 µg/kg/h (1, 1.2). A higher cumulative dexmedetomidine dose of 119.2 µg/kg (96.6, 154.9) and duration of 142.9 hours (122.6, 158.3) were noted in patients who required a taper modification. Risk factors for dexmedetomidine withdrawal such as dexmedetomidine duration and cumulative dose may help predict patients at the highest risk of withdrawal that would benefit from an enteral clonidine taper to prevent dexmedetomidine withdrawal symptoms. An enteral clonidine taper can be effective in the prevention and management of dexmedetomidine withdrawal symptoms.

5.
J Oral Rehabil ; 49(7): 746-753, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35388515

RESUMO

AIM: This topical review presents common patients' misbeliefs about temporomandibular disorders (TMD) and discusses their possible impact on the diagnosis, treatment and prognosis. We also discussed the possible influence of the beliefs and behaviours of healthcare providers on the beliefs of patients with TMD and suggested possible strategies to overcome the negative impacts of such misbeliefs. METHODS: This topical review was based on a non-systematic search for studies about the beliefs of patients and healthcare professionals about TMD in PubMed and Embase. RESULTS: Patients' beliefs can negatively impact the diagnosis, treatment and prognosis of TMD. These beliefs can be modulated by several factors such as culture, psychosocial aspects, gender, level of knowledge and previous experiences. Moreover, primary healthcare professionals, including dentists, may lack sufficient experience and skills regarding TMD diagnosis and treatment. Misbeliefs of the healthcare professionals can be based on outdated evidence that is not supported by rigorous methodological investigations. Education and dissemination of knowledge to patients and the general population are effective for prevention, promotion of health and disruption of the cycle of misinformation and dissemination of misbeliefs. CONCLUSION: The lack of basic information about TMD and the dissemination of mistaken and outdated concepts may delay the diagnosis, hinder the treatment, and consequently increase the risk of worsening the condition. Education is key to overcome TMD misbeliefs.


Assuntos
Dor Facial , Transtornos da Articulação Temporomandibular , Dor Facial/terapia , Humanos , Transtornos da Articulação Temporomandibular/psicologia
6.
Pain ; 163(5): 936-942, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34433771

RESUMO

ABSTRACT: There is a need to further develop telemedicine approaches because of the immediate and perhaps long-term consequences of the coronavirus disease 2019. Thus, a remote protocol for assessment of patients with temporomandibular disorders (TMD) was developed, and the agreement of this protocol was compared with the guidelines of the Diagnostic Criteria for TMD (DC/TMD). A total of 16 individuals were first assessed by a reference standard examination (RSE) and 3 other examinations applied in a random order by 3 examiners: standard physical examination (standard examination), physical examination keeping 2-m distance (physical distanced examination), and examination conducted with the aid of video communication technology (video communication examination). The primary outcomes were the diagnoses of myalgia of the masseter and temporalis muscles and arthralgia. The diagnoses of intra-articular joint disorders were considered secondary outcomes because of a less impact on psychosocial functioning and quality of life when compared with the pain-related diagnoses. The Fleiss kappa coefficient and its 95% confidence interval were computed to determine the level of agreement in diagnoses between each examination protocol and the RSE. There was substantial to almost perfect agreement between the RSE and all the examination protocols for the diagnoses of myalgia (0.86-1.00) and arthralgia (0.74-0.87) (P < 0.001). On the other hand, there was an overall poor agreement (0.30-0.58) between the RSE and all the protocols for the diagnosis of disk displacement with reduction. Remote assessment of patients with pain-related TMD is feasible and presents a high degree of accuracy.


Assuntos
Exame Físico , Telemedicina , Transtornos da Articulação Temporomandibular , Artralgia , COVID-19 , Humanos , Mialgia , Exame Físico/métodos , Qualidade de Vida , Transtornos da Articulação Temporomandibular/diagnóstico
7.
Zootaxa ; 5067(3): 377-400, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34810737

RESUMO

Although Colombia is perceived as one of the most diverse countries in reptiles, the distribution of many microteiid lizards of the Alopoglossidae and Gymnophthalmidae families is still poorly known. This is particularly true for those species in the cis-Andean regions, in part due to the remoteness or socio-political issues within some of these territories. In order to elucidate the diversity and distribution of the cis-Andean microteiids in Colombia, in this study we present a review based on the examination of specimens deposited in the reptile collection at Instituto de Investigacin Alexander von Humboldt, one of the most important Colombian biological collections, and data from the literature. We reported a total of 29 taxa, in which three are new records for Colombia and three are range extensions. Two species were assigned to species complex because their morphological determination was non-conclusive, and three were identified just to genus, since they may correspond to more than one entity or be currently non-described. We found that nine species are distributed in both the Amazonia and Orinoquia regions, nine are currently only present in the Amazonia and seven are in the Orinoquia. Based on our data, we highlight the importance of using local museums to increase the taxonomic and geographic data coverage, we discuss the taxonomic difficulties for some taxa, as well as the potential for future research and their constraints. Finally, we present a taxonomic key for the identification of the microteiids present in the Orinoquia and Amazonia regions of Colombia.


Assuntos
Lagartos , Animais , Brasil , Colômbia
8.
Sci Total Environ ; 686: 151-157, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31176814

RESUMO

Daphnia populations are present in lakes and ponds. They are known to experience diurnal vertical migrations according to their feeding needs. During the day they migrate downwards to avoid predation in light-receiving layers and at night they migrate upwards, searching for food in the shallow productive layers. The light photoperiod and light intensity vary depending on the latitude and, therefore, the precise location of lakes and ponds will be an additional and crucial parameter in determining the development of Daphnia. Here we will focus on a population of Daphnia magna (a genus of the Cladocera order). The effect of both light intensity and photoperiod on Daphnia filtration was studied in laboratory experiments. An increase in the light intensity resulted in two D. magna responses depending on the exposure time of individuals to light. Short time exposures to a decrease in the light intensity of less than one day produced an increase in the D. magna filtration. However, exposures of longer than one day resulted in a decrease in the D. magna filtration along with a decrease in the light intensity. Photoperiod exposures of 8, 12 and 16 h produced greater D. magna filtrations than photoperiods of 0, 4 and 24 h. In this study, regulation of the light intensity and the period of exposure were used in laboratory experiments to establish D. magna development thresholds by latitudinal variation in the photoperiod.


Assuntos
Daphnia/fisiologia , Fotoperíodo , Animais , Filtração , Luz
9.
Environ Pollut ; 251: 434-441, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31103003

RESUMO

There is consensus on the need to study the potential impact microplastics (MP) have on freshwater planktonic organisms. It is not yet fully understood how MP enter the aquatic food web or the effect they have on all the trophic levels. As a result of the potential for MP to accumulate throughout food webs, there is increasing interest in evaluating their fate in a variety of environmental conditions. This study investigated the variability in the ingestion of MP to food ratios and the exposed time of MP to Daphnia magna in non-sheared and sheared conditions. The sheared environment provided Daphnia magna with the conditions for optimal filtering capacity. Regardless of the ratios of MP concentration to food concentration (MP:Food), the filtration capacity of the Daphnia magna was enhanced in the sheared experiments. In both the sheared and non-sheared experiments, filtration capacity decreased when the ratios of MP to food concentration and the exposure times to MP were increased. Mortality was mainly enhanced in the non-sheared conditions at higher MP concentrations and exposure times to MP. No mortality was found in the sheared conditions for the exposure times studied. Therefore, in aquatic systems that undergo constant low sheared conditions, Daphnia magna can survive longer when exposed to MP than in calm conditions, provided food concentrations do not limit their capacity to filter.


Assuntos
Daphnia/fisiologia , Exposição Dietética/efeitos adversos , Plásticos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Daphnia/metabolismo , Exposição Dietética/análise , Ingestão de Alimentos , Alimentos , Hidrodinâmica , Plásticos/análise , Plásticos/isolamento & purificação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
10.
Sci Rep ; 9(1): 3844, 2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30846810

RESUMO

Daphnia are important to understanding the biogeochemistry of aquatic ecosystems, mainly because of their ability to filter bacteria, algae and inorganic particles as well. Although there are many studies on the general effects that biotic and abiotic stressors, increased temperature and hypoxia, salinity, metals, pharmaceuticals, pesticides, etc., have on Daphnia populations, little is known about the impact elevated turbulence has. Here, we show that turbulence affects Daphnia magna survival, swimming behaviour and filtering capacity. Our data demonstrate that altering their habitat by induced mixing from turbulence, induces an increased filtering capacity of the Daphnia magna individuals, provided the level of background turbulence (defined by the dissipation of turbulent kinetic energy) is lower than ε = 0.04 cm2 s-3. The filtering capacity reduced exponentially with increasing ε, and at ε > 1 cm2 s-3 both mobility and filtration were suppressed and eventually led to the death of all the Daphnia magna individuals.


Assuntos
Daphnia/fisiologia , Animais , Ecossistema , Hidrodinâmica , Natação/fisiologia
11.
PLoS One ; 13(12): e0209705, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30576390

RESUMO

Analysing the effect water temperature has on Daphnia magna is essential in anticipating the impact climate change will have on this freshwater zooplanktonic keystone species. While many authors have followed this line of research, few have covered an extensive temperature range or complex temperature change scenarios. Global warming is mostly associated with increased extreme temperature events, such as heat waves, as well as earlier and more intense thermal stratification. Both of these events may directly influence D. magna fitness, especially in those populations performing diel vertical migration (DVM). We analysed the effect water temperatures, ranging from 11 to 29°C, have on the filtration capacity (FC) of D. magna, to anticipate the effects of acclimation, temperature change rate (TCR) and potential reversibility of responses to such conditions. Results show that sudden temperature changes have an immediate negative impact on the FC of D. magna and is more severe at higher temperatures and higher TCRs. However, D. magna individuals have shown themselves to be capable of quasi-acclimating to temperatures ranging from 11 to 25°C in around a week and achieving much higher FCs; albeit never reaching the optimal FC achieved at 20°C. That said, 29°C is lethal for D. magna individuals within approximately five days. Finally, non-optimal temperature acclimated individuals can recover maximal FC within 2-4 days of the optimal long-term acclimation temperature (20°C) being re-established, thus proving temperature responses to be reversible.


Assuntos
Aclimatação/fisiologia , Mudança Climática , Daphnia/fisiologia , Animais , Água Doce , Temperatura
12.
Angew Chem Int Ed Engl ; 57(17): 4603-4606, 2018 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-29481726

RESUMO

We report here the first purely organometallic fac-[MnI (CO)3 (bis-Me NHC)Br] complex with unprecedented activity for the selective electrocatalytic reduction of CO2 to CO, exceeding 100 turnovers with excellent faradaic yields (ηCO ≈95 %) in anhydrous CH3 CN. Under the same conditions, a maximum turnover frequency (TOFmax ) of 2100 s-1 was measured by cyclic voltammetry, which clearly exceeds the values reported for other manganese-based catalysts. Moreover, the addition of water leads to the highest TOFmax value (ca. 320 000 s-1 ) ever reported for a manganese-based catalyst. A MnI tetracarbonyl intermediate was detected under catalytic conditions for the first time.

13.
Braz J Phys Ther ; 22(3): 215-221, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29258735

RESUMO

BACKGROUND: Advanced lung disease is a chronic non-neoplastic disease that compromises activities of daily living. Treatment includes pulmonary rehabilitation and inspiratory muscle training. Studies have shown the effectiveness of inspiratory muscle training in lung disease patients, but literature is scarce on the patients' perceptions about this topic. OBJECTIVE: To explore the perceptions of patients with advanced lung disease about inspiratory muscle training. METHODS: Qualitative study. Interviews were conducted using a semi-structured questionnaire regarding topics on the participation of patients in inspiratory muscle training and on daily activities performed before and after training. Interviews were transcribed and analyzed according to thematic content analysis. RESULTS: Ten patients (eight women and 2 men, ranging in age from 27 to 89 years) with inspiratory muscle weakness (maximal inspiratory pressure=44±13.9cmH2O) were included. Five patients were diagnosed with Chronic Obstructive Pulmonary Disease, two with bronchiectasis and three with pulmonary fibrosis. All patients completed at least 80% of the total training sessions. The reports were grouped into four thematic categories: (1) impact of inspiratory muscle training on breathlessness (e.g., "I wasn't feeling as tired as I previously felt."); (2) change in daily activities (e.g., "I needed to go to the supermarket, I felt less tired doing it."); (3) improved mobility (e.g., "I could not stand for long periods […] walking, for example […] Now I stand more, I have more capability."); and (4) increased communication (e.g., "More power, right? Even in speaking […] When I could, I felt my voice coming out better."). CONCLUSION: There were improvements in breathlessness, daily activities, mobility, and communication, which positively affected the psychological and social aspects of the patients.


Assuntos
Pulmão/fisiopatologia , Debilidade Muscular/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Atividades Cotidianas , Humanos , Pressões Respiratórias Máximas , Modalidades de Fisioterapia , Terapia Respiratória , Caminhada
14.
Life (Basel) ; 7(4)2017 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-29160840

RESUMO

We report the heterologous expression and molecular characterization of the first extremely halophilic alpha-glucosidase (EC 3.2.1.20) from the archaeon Haloquadratum walsbyi. A 2349 bp region (Hqrw_2071) from the Hqr. walsbyi C23 annotated genome was PCR-amplified and the resulting amplicon ligated into plasmid pET28b(+), expressed in E. coli Rosetta cells, and the resulting protein purified by Ni-NTA affinity chromatography. The recombinant protein showed an estimated molecular mass of 87 kDa, consistent with the expected value of the annotated protein, and an optimal activity for the hydrolysis of α-PNPG was detected at 40 °C, and at pH 6.0. Enzyme activity values were the highest in the presence of 3 M NaCl or 3-4 M KCl. However, specific activity values were two-fold higher in the presence of 3-4 M KCl when compared to NaCl suggesting a cytoplasmic localization. Phylogenetic analyses, with respect to other alpha-glucosidases from members of the class Halobacteria, showed that the Hqr. walsbyi MalH was most similar (up to 41%) to alpha-glucosidases and alpha-xylosidases of Halorubrum. Moreover, computational analyses for the detection of functional domains, active and catalytic sites, as well as 3D structural predictions revealed a close relationship with an E. coli YicI-like alpha-xylosidase of the GH31 family. However, the purified enzyme did not show alpha-xylosidase activity. This narrower substrate range indicates a discrepancy with annotations from different databases and the possibility of specific substrate adaptations of halophilic glucosidases due to high salinity. To our knowledge, this is the first report on the characterization of an alpha-glucosidase from the halophilic Archaea, which could serve as a new model to gain insights into carbon metabolism in this understudied microbial group.

15.
Am J Vet Res ; 77(12): 1318-1324, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27901396

RESUMO

OBJECTIVE To determine the effects of acepromazine maleate premedication on cardiovascular function before and after infusion of dobutamine hydrochloride for 30 minutes in isoflurane-anesthetized horses. ANIMALS 6 healthy adult horses. PROCEDURES Each horse was anesthetized once following premedication with acepromazine (0.02 mg/kg, IV) administered 30 minutes prior to anesthetic induction (ACP+ treatment) and once without premedication (ACP- treatment). Anesthesia was induced with IV administration of xylazine hydrochloride (0.8 mg/kg), ketamine hydrochloride (2.2 mg/kg), and diazepam (0.08 mg/kg). Horses were positioned in right lateral recumbency, and anesthesia was maintained via inhalation of isoflurane delivered in oxygen. End-tidal isoflurane concentration was adjusted to achieve a target mean arterial blood pressure of 60 mm Hg (interquartile range [25th to 75th percentile], 57 to 63 mm Hg) for at least 15 minutes. Cardiac index, oxygen delivery index, and femoral arterial blood flow indices were determined 60 minutes after anesthetic induction (baseline). Dobutamine was then infused to achieve a target mean arterial blood pressure of 80 mm Hg (interquartile range, 76 to 80 mm Hg). Data collection was repeated 30 minutes after the start of dobutamine infusion for comparison with baseline values. RESULTS Complete data sets were available from 5 of the 6 horses. Dobutamine administration resulted in significant increases in oxygen delivery and femoral arterial blood flow indices but no significant change in cardiac index for each treatment. However, at baseline or 30 minutes after the start of dobutamine infusion, findings for the ACP+ and ACP- treatments did not differ. CONCLUSIONS AND CLINICAL RELEVANCE In isoflurane-anesthetized horses, dobutamine administration increased oxygen delivery and femoral arterial blood flow indices, but these changes were unaffected by premedication with acepromazine.


Assuntos
Cardiotônicos/farmacologia , Dobutamina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Cavalos/fisiologia , Acepromazina/administração & dosagem , Anestesia/veterinária , Anestésicos Inalatórios/administração & dosagem , Animais , Antipsicóticos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Cardiotônicos/administração & dosagem , Dobutamina/administração & dosagem , Esquema de Medicação , Hemodinâmica/efeitos dos fármacos , Infusões Intravenosas/veterinária , Isoflurano/administração & dosagem , Masculino , Pré-Medicação/veterinária
16.
Dalton Trans ; 45(34): 13541-6, 2016 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-27506414

RESUMO

Chelating bis-N-heterocyclic carbene (bis-NHC) complexes of iron(ii) containing pyridyl ligands have been prepared by the reaction of [FeCl2L] [L = bipy (1), phen (2)] with [LiN(SiMe3)2] and a bis(imidazolium) salt. The [Fe(bis-NHC)L(I)2] complexes were active pre-catalysts in the oxidation of 1-phenylethanol with tert-butyl hydroperoxide in neat conditions, affording a quantitative yield of acetophenone in 4.5 h. The catalyst could be reused up to six cycles giving a turnover number (TON) of 1500. Various secondary alcohols, both aromatic and aliphatic were selectivity oxidised to the corresponding ketones in excellent yields. Compound 1 is stable in acetonitrile solution for ca. 4 h, although after 16 h, it evolves to a mixture of [Fe(bis-NHC)(bipy)2]I2 (3), [Fe(bipy)3](2+) and bis-imidazolium salt. The molecular structure of 3 has been determined by X-ray diffraction studies.

17.
Genom Data ; 7: 243-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26981418

RESUMO

We report here the draft genome sequence of a novel UV-resistant bacterium isolated from dry soil on the south coast of Puerto Rico. Based on polyphasic taxonomy, strain MC1A represents a new species and the name Solirubrum puertoriconensis is proposed. Assembly was performed using NGEN Assembler into eight contigs (N50 = 1,292,788), the largest of which included 1,549,887 bp. The draft genome consists of 4,810,875 bp and has a GC content of 58.7%. Several genes related to DNA repair and UV resistance were found. The Whole Genome Shotgun project is available at DDBJ/EMBL/GenBank under the accession LNAL00000000.

18.
Ann Bot ; 110(6): 1263-70, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23002270

RESUMO

BACKGROUND: Grasslands are a major part of the global ecosystem, covering 37 % of the earth's terrestrial area. For a variety of reasons, mostly related to overgrazing and the resulting problems of soil erosion and weed encroachment, many of the world's natural grasslands are in poor condition and showing signs of degradation. This review examines their contribution to global food supply and to combating climate change. SCOPE: Grasslands make a significant contribution to food security through providing part of the feed requirements of ruminants used for meat and milk production. Globally, this is more important in food energy terms than pig meat and poultry meat. Grasslands are considered to have the potential to play a key role in greenhouse gas mitigation, particularly in terms of global carbon storage and further carbon sequestration. It is estimated that grazing land management and pasture improvement (e.g. through managing grazing intensity, improved productivity, etc) have a global technical mitigation potential of almost 1·5 Gt CO(2) equivalent in 2030, with additional mitigation possible from restoration of degraded lands. Milk and meat production from grassland systems in temperate regions has similar emissions of carbon dioxide per kilogram of product as mixed farming systems in temperate regions, and, if carbon sinks in grasslands are taken into account, grassland-based production systems can be as efficient as high-input systems from a greenhouse gas perspective. CONCLUSIONS: Grasslands are important for global food supply, contributing to ruminant milk and meat production. Extra food will need to come from the world's existing agricultural land base (including grasslands) as the total area of agricultural land has remained static since 1991. Ruminants are efficient converters of grass into humanly edible energy and protein and grassland-based food production can produce food with a comparable carbon footprint as mixed systems. Grasslands are a very important store of carbon, and they are continuing to sequester carbon with considerable potential to increase this further. Grassland adaptation to climate change will be variable, with possible increases or decreases in productivity and increases or decreases in soil carbon stores.


Assuntos
Sequestro de Carbono , Mudança Climática , Abastecimento de Alimentos , Poaceae , Adaptação Biológica , Agricultura , Animais , Ecossistema , Humanos , Carne , Leite , Ruminantes/crescimento & desenvolvimento , Ruminantes/fisiologia
19.
J Chromatogr B Analyt Technol Biomed Life Sci ; 879(32): 3853-8, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22100550

RESUMO

This work discusses the application of an aqueous two-phase system for the purification of lipases produced by Bacillus sp. ITP-001 using polyethylene glycol (PEG) and potassium phosphate. In the first step, the protein content was precipitated with ammonium sulphate (80% saturation). The enzyme remained in the aqueous solution and was dialyzed against ultra-pure water for 18 h and used to prepare an aqueous two-phase system (PEG/potassium phosphate). The use of different molecular weights of PEG to purify the lipase was investigated; the best purification factor (PF) was obtained using PEG 20,000g/mol, however PEG 8000 was used in the next tests due to lower viscosity. The influence of PEG and potassium phosphate concentrations on the enzyme purification was then studied: the highest FP was obtained with 20% of PEG and 18% of potassium phosphate. NaCl was added to increase the hydrophobicity between the phases, and also increased the purification factor. The pH value and temperature affected the enzyme partitioning, with the best purifying conditions achieved at pH 6.0 and 4°C. The molecular mass of the purified enzyme was determined to be approximately 54 kDa by SDS-PAGE. According to the results the best combination for purifying the enzyme is PEG 8000g/mol and potassium phosphate (20/18%) with 6% of NaCl at pH 6.0 and 4°C (201.53 fold). The partitioning process of lipase is governed by the entropy contribution.


Assuntos
Bacillus/enzimologia , Fracionamento Químico/métodos , Lipase/isolamento & purificação , Bacillus/metabolismo , Eletroforese em Gel de Poliacrilamida , Fermentação , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lipase/biossíntese , Fosfatos/química , Polietilenoglicóis/química , Compostos de Potássio/química , Cloreto de Sódio , Temperatura
20.
Eur J Endocrinol ; 165(2): 233-41, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21646290

RESUMO

BACKGROUND: A limited number of mutations in the GH secretagogue receptor gene (GHSR) have been described in patients with short stature. Objective To analyze GHSR in idiopathic short stature (ISS) children including a subgroup of constitutional delay of growth and puberty (CDGP) patients. SUBJECTS AND METHODS: The GHSR coding region was directly sequenced in 96 independent patients with ISS, 31 of them with CDGP, in 150 adults, and in 197 children with normal stature. The pharmacological consequences of GHSR non-synonymous variations were established using in vitro cell-based assays. RESULTS: Five different heterozygous point variations in GHSR were identified (c.-6 G>C, c.251G>T (p.Ser84Ile), c.505G>A (p.Ala169Thr), c.545 T>C (p.Val182Ala), and c.1072G>A (p.Ala358Thr)), all in patients with CDGP. Neither these allelic variants nor any other mutations were found in 694 alleles from controls. Functional studies revealed that two of these variations (p.Ser84Ile and p.Val182Ala) result in a decrease in basal activity that was in part explained by a reduction in cell surface expression. The p.Ser84Ile mutation was also associated with a defect in ghrelin potency. These mutations were identified in two female patients with CDGP (at the age of 13 years, their height SDS were -2.4 and -2.3). Both patients had normal progression of puberty and reached normal adult height (height SDS of -0.7 and -1.4) without treatment. CONCLUSION: This is the first report of GHSR mutations in patients with CDGP. Our data raise the intriguing possibility that abnormalities in ghrelin receptor function may influence the phenotype of individuals with CDGP.


Assuntos
Transtornos do Crescimento/genética , Mutação de Sentido Incorreto , Puberdade Tardia/genética , Receptores de Grelina/genética , Adolescente , Adulto , Constituição Corporal/genética , Constituição Corporal/fisiologia , Células Cultivadas , Criança , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Grelina/metabolismo , Humanos , Masculino , Modelos Biológicos , Mutação de Sentido Incorreto/fisiologia , Receptores de Grelina/metabolismo , Transfecção
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