389 research outputs found

    Alkyl substituted cucurbit[6]uril assisted competitive fluorescence recognition of lysine and methionine in aqueous solution

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    The use of competitive ratiometric fluorescence indicator displacement chemosensors derived from two alkyl substituted cucurbit[6]uril-based host-guest complexes is reported. In particular, the differing binding abilities of two cucurbit[6]uril derivatives towards the target analytes led to a useful ratiometric detection signal output for the discrimination of lysine and methionine versus the other tested α-amino acids in aqueous solution

    Carbon Sequestration in Relation to Shrub Size in the Desert Ecosystem

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    Desert ecosystems have been reported as the location of the long-sought ‘missing sink’ for atmospheric carbon dioxide and as a potentially important area for carbon sequestering from fossil fuel combustion in the future (Stone 2008). Researchers have found that net uptake of carbon in the Mojave Desert ranged from 102 to 127 g C m2/yr during a 3-year period, which is equivalent to the net ecosystem production of many forest ecosystems with a much higher biomass (Luyssaert et al. 2007; Wohlfahrt et al. 2008). Shrub is the dominant plant of desert ecosystems (Gratani et al. 2011); hence, it is important to understand the dynamics of carbon sequestration by shrubs as well as their role in desert ecosystem carbon balance. Information on the carbon sequestration associated with shrub size is limited. Our objective was, therefore, to find out the relationship between carbon sequestration potential and size of shrubs

    Megasphaera elsdenii Lactate Degradation Pattern Shifts in Rumen Acidosis Models

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    Background: Megasphaera elsdenii is an ecologically important rumen bacterium that metabolizes lactate and relieves rumen acidosis (RA) induced by a high-grain-diet. Understanding the regulatory mechanisms of the lactate metabolism of this species in RA conditions might contribute to developing dietary strategies to alleviate RA. Methods: Megasphaera elsdenii was co-cultured with four lactate producers (Streptococcus bovis, Lactobacilli fermentum, Butyrivibrio fibrisolvens, and Selenomonas ruminantium) and a series of substrate starch doses (1, 3, and 9 g/L) were used to induce one normal and two RA models (subacute rumen acidosis, SARA and acute rumen acidosis, ARA) under batch conditions. The associations between bacterial competition and the shift of organic acids' (OA) accumulation patterns in both statics and dynamics manners were investigated in RA models. Furthermore, we examined the effects of substrate lactate concentration and pH on Megasphaera elsdenii's lactate degradation pattern and genes related to the lactate utilizing pathways in the continuous culture. Results and Conclusion: The positive growth of M. elsdenii and B. fibrisolvens caused OA accumulation in the SARA model to shift from lactate to butyrate and resulted in pH recovery. Furthermore, both the quantities of substrate lactate and pH had remarkable effects on M. elsdenii lactate utilization due to the transcriptional regulation of metabolic genes, and the lactate utilization in M. elsdenii was more sensitive to pH changes than to the substrate lactate level. In addition, compared with associations based on statics data, associations discovered from dynamics data showed greater significance and gave additional explanations regarding the relationships between bacterial competition and OA accumulation

    Megasphaera elsdenii Lactate Degradation Pattern Shifts in Rumen Acidosis Models

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    Background:Megasphaera elsdenii is an ecologically important rumen bacterium that metabolizes lactate and relieves rumen acidosis (RA) induced by a high-grain-diet. Understanding the regulatory mechanisms of the lactate metabolism of this species in RA conditions might contribute to developing dietary strategies to alleviate RA.Methods:Megasphaera elsdenii was co-cultured with four lactate producers (Streptococcus bovis, Lactobacilli fermentum, Butyrivibrio fibrisolvens, and Selenomonas ruminantium) and a series of substrate starch doses (1, 3, and 9 g/L) were used to induce one normal and two RA models (subacute rumen acidosis, SARA and acute rumen acidosis, ARA) under batch conditions. The associations between bacterial competition and the shift of organic acids’ (OA) accumulation patterns in both statics and dynamics manners were investigated in RA models. Furthermore, we examined the effects of substrate lactate concentration and pH on Megasphaera elsdenii’s lactate degradation pattern and genes related to the lactate utilizing pathways in the continuous culture.Results and Conclusion: The positive growth of M. elsdenii and B. fibrisolvens caused OA accumulation in the SARA model to shift from lactate to butyrate and resulted in pH recovery. Furthermore, both the quantities of substrate lactate and pH had remarkable effects on M. elsdenii lactate utilization due to the transcriptional regulation of metabolic genes, and the lactate utilization in M. elsdenii was more sensitive to pH changes than to the substrate lactate level. In addition, compared with associations based on statics data, associations discovered from dynamics data showed greater significance and gave additional explanations regarding the relationships between bacterial competition and OA accumulation

    Identification of renal cyst cells of type I Nephronophthisis by single-nucleus RNA sequencing

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    Background: Nephronophthisis (NPH) is the most common genetic cause of end-stage renal disease (ESRD) in childhood, and NPHP1 is the major pathogenic gene. Cyst formation at the corticomedullary junction is a pathological feature of NPH, but the mechanism underlying cystogenesis is not well understood. The isolation and identification of cystic cell subpopulation could help to identify their origins and provide vital clues to the mechanisms underlying cystogenesis in NPH.Methods: Single-nucleus RNA sequencing (snRNA-seq) was performed to produce an atlas of NPHP1 renal cells. Kidney samples were collected from WT (Nphp1+/+) mice and NPHP1 (Nphp1del2-20/del2-20) model mice.Results: A comprehensive atlas of the renal cellular landscape in NPHP1 was generated, consisting of 14 basic renal cell types as well as a subpopulation of DCT cells that was overrepresented in NPHP1 kidneys compared to WT kidneys. GO analysis revealed significant downregulation of genes associated with tubular development and kidney morphogenesis in this subpopulation. Furthermore, the reconstruction of differentiation trajectories of individual cells within this subpopulation confirmed that a specific group of cells in NPHP1 mice become arrested at an early stage of differentiation and proliferate to form cysts. We demonstrate that Niban1 is a specific molecular marker of cystic cells in both mice and human NPHP1.Conclusion: In summary, we report a novel subpopulation of DCT cells, marked by Niban1, that are classified as cystic cells in the NPHP1 mice kidney. These results offer fresh insights into the cellular and molecular basis of cystogenesis in NPH

    Padronização da pesquisa de linfonodos sentinelas em estômago por métodos combinados

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    Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Pós-Graduação em Ciências da Cirurgia, Campinas, 2012.Introdução - Com os estudos de Gould et al. (1960), Cabanas (1977) e Morton et al. (1992), estabeleceu-se o conceito da pesquisa do linfonodo sentinela. Esse se baseia na teoria de que ao identificar a presença ou ausência de metástase no primeiro linfonodo que recebe a drenagem linfática a partir do tumor (sentinela), poderia representar o estado de acometimento dos outros linfonodos. Isto evitaria a realização desnecessária de linfadenectomias. Com o passar dos anos, foi consagrada para ser aplicada em casos de melanoma e câncer de mama. Nesta última década, tenta-se estender os princípios da utilização da pesquisa de linfonodo sentinela para os cânceres do aparelho digestivo. Entretanto, no caso do estômago, existem algumas dificuldades, como: presença de sistema de drenagem linfática multidirecional, ocorrência de metástases saltatórias e identificação de mais de um linfonodo sentinela por indivíduo. Objetivo - Criar e padronizar um modelo animal para o treinamento de pesquisa de linfonodos sentinelas em estômago. Método - Trinta e dois coelhos, saudáveis, foram submetidos à anestesia exclusivamente intramuscular. Por meio de laparotomia, foi injetado na subserosa da parede anterior do corpo gástrico, 0,1 ml de fitato marcado com tecnécio-99m (0,2 mCi), em seguida pelo mesmo orifício, de 0,2 ml de Azul Patente V® 2,5%. A cavidade abdominal foi avaliada, in vivo , para pesquisa de suspeitas de linfonodos azuis (corados em azul) e com detector manual de radiação gamma aos 5, 10 e 20 minutos para detecção de suspeitas de linfonodos radioativos (radioatividade identificada superior a 10X o valor apresentado pelo fundo). Após 20 minutos, realizou-se ressecção e exérese total do estômago, baço e suspeitas de linfonodos, para posterior avaliação da radioatividade ex vivo . A seguir, encaminharam-se as suspeitas de linfonodos para estudo histológico para identificação de tecido linfóide. Resultados - Foram identificados linfonodos em 30 coelhos (93,75%) com média de 2,2 por animal. Das 90 suspeitas de linfonodos detectadas, em 70 casos (77,77%) obteve-se confirmação histológica para tecido linfóide. Dessas, a maioria foi identificada e localizada na região entre o esôfago e o fundo gástrico durante a avaliação in vivo aos 5 minutos. Dois coelhos faleceram durante os experimentos (Taxa de mortalidade = 6,25%). Conclusão - O modelo experimental em coelhos para pesquisa de linfonodos sentinelas em estômago por métodos combinados foi factível, de fácil execução e baixa mortalidade, podendo ser usado para treinamento.Abstract : Introduction - The concept of sentinel lymph node was established by the studies of Gould et al. (1960), Cabanas (1977) and Morton et al. (1992). It is based on the theory that, whenever the presence or absence of metastasis is identified in the first lymph node that receives the lymphatic drainage from the tumor (sentinel) the status of involvement of other lymph nodes might be infered. This could avoid the performance of unnecessary lymphadenectomies. Over the years, its use was consecrated by its application in melanoma and breast cancer. In the last decade, attempts have been made to extend the principles of sentinel lymph node investigation to cancers of the digestive tract. In the case of stomach cancer, additional difficulties were found, such as multiple and aberrant lymphatic routes, the occurrence of skip metastasis and the possible identification of more than one sentinel lymph node in the same patient. Aim - To develop and evaluate an animal model for training sentinel lymph node navigation in the stomach. Methods - Thirtytwo healthy rabbits, were prepped and given intramuscular anesthesia. Through a formal laparotomy, they received a subserosal injection of 0.1 ml of phytate labeled with technetium-99m (0.2 mCi) in the anterior wall of the gastric corpus, followed by 0.2 ml of Blue Patent ® V 2.5%, through the same puncture site. Suspicious lymph nodes were searched in-vivo at 5, 10 and 20 minutes, both visually (Blue Patent stained lymph nodes) and with a manual gamma radiation detector (to detect suspected radioactive lymph nodes, displaying radioactivity levels over 10X the value displayed by the background). En-block resection of the stomach, spleen, visible limph nodes and local fat tissue was then performed and the specimen was assessed "ex vivo" for radioactivity. Suspected lymph nodes were sent for histological study to evaluate the presence of lymphoid tissue. Results Radiolabeled or stained lymph nodes were identified in 30 rabbits (93.75%) with an average of 2.2 specimens per animal; of the 90 suspicious lymph nodes detected, histology confirmed lymphoid tissue in 70 cases (77.77%). Most lymph nodes were identified at the 5-minute in-vivo evaluation and their most common location was found to be in the region between the esophagus and the gastric fundus. Two rabbits died during the procedure resulting in a 6.25% mortality. Conclusion - The rabbit model proved adequate for training in sentinel node navigation in the stomach by combined methods (dye and radiocolloid) being easy to execute and associated with low mortality

    A large genome-wide association study of age-related macular degeneration highlights contributions of rare and common variants.

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    This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ng.3448Advanced age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, with limited therapeutic options. Here we report on a study of >12 million variants, including 163,714 directly genotyped, mostly rare, protein-altering variants. Analyzing 16,144 patients and 17,832 controls, we identify 52 independently associated common and rare variants (P < 5 × 10(-8)) distributed across 34 loci. Although wet and dry AMD subtypes exhibit predominantly shared genetics, we identify the first genetic association signal specific to wet AMD, near MMP9 (difference P value = 4.1 × 10(-10)). Very rare coding variants (frequency <0.1%) in CFH, CFI and TIMP3 suggest causal roles for these genes, as does a splice variant in SLC16A8. Our results support the hypothesis that rare coding variants can pinpoint causal genes within known genetic loci and illustrate that applying the approach systematically to detect new loci requires extremely large sample sizes.We thank all participants of all the studies included for enabling this research by their participation in these studies. Computer resources for this project have been provided by the high-performance computing centers of the University of Michigan and the University of Regensburg. Group-specific acknowledgments can be found in the Supplementary Note. The Center for Inherited Diseases Research (CIDR) Program contract number is HHSN268201200008I. This and the main consortium work were predominantly funded by 1X01HG006934-01 to G.R.A. and R01 EY022310 to J.L.H

    Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

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    Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a ZZ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 <pT<100< p_{\textrm{T}} < 100 GeV and in the pseudorapidity range 2.5<η<42.5 < \eta < 4. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb1^{-1}. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages
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