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1.
Phys Rev Lett ; 133(12): 121004, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39373410

RESUMO

We report results from an analysis aimed at detecting the trispectrum of the kinematic Sunyaev-Zel'dovich (kSZ) effect by combining data from the South Pole Telescope (SPT) and Herschel-SPIRE experiments over a 100 deg^{2} field. The SPT observations combine data from the previous and current surveys, namely SPTpol and SPT-3G, to achieve depths of 4.5, 3, and 16 µK-arcmin in bands centered at 95, 150, and 220 GHz. For SPIRE, we include data from the 600 and 857 GHz bands. We reconstruct the velocity-induced large-scale correlation of the small-scale kSZ signal with a quadratic estimator that uses two cosmic microwave background (CMB) temperature maps, constructed by optimally combining data from all the frequency bands. We reject the null hypothesis of a zero trispectrum at 10.3σ level. However, the measured trispectrum contains contributions from both the kSZ and other undesired components, such as CMB lensing and astrophysical foregrounds, with kSZ being sub-dominant. We use the agora simulations to estimate the expected signal from CMB lensing and astrophysical foregrounds. After accounting for the contributions from CMB lensing and foreground signals, we do not detect an excess kSZ-only trispectrum and use this nondetection to set constraints on reionization. By applying a prior based on observations of the Gunn-Peterson trough, we obtain an upper limit on the duration of reionization of Δz_{re,50}<4.5 (95% confidence level). We find these constraints are fairly robust to foregrounds assumptions. This trispectrum measurement is independent of, but consistent with, Planck's optical depth measurement. This result is the first constraint on the epoch of reionization using the non-Gaussian nature of the kSZ signal.

2.
EMBO Rep ; 23(2): e53968, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-34866320

RESUMO

Mammalian development begins in transcriptional silence followed by a period of widespread activation of thousands of genes. DNA methylation reprogramming is integral to embryogenesis and linked to Tet enzymes, but their function in early development is not well understood. Here, we generate combined deficiencies of all three Tet enzymes in mouse oocytes using a morpholino-guided knockdown approach and study the impact of acute Tet enzyme deficiencies on preimplantation development. Tet1-3 deficient embryos arrest at the 2-cell stage with the most severe phenotype linked to Tet2. Individual Tet enzymes display non-redundant roles in the consecutive oxidation of 5-methylcytosine to 5-carboxylcytosine. Gene expression analysis uncovers that Tet enzymes are required for completion of embryonic genome activation (EGA) and fine-tuned expression of transposable elements and chimeric transcripts. Whole-genome bisulfite sequencing reveals minor changes of global DNA methylation in Tet-deficient 2-cell embryos, suggesting an important role of non-catalytic functions of Tet enzymes in early embryogenesis. Our results demonstrate that Tet enzymes are key components of the clock that regulates the timing and extent of EGA in mammalian embryos.


Assuntos
Dioxigenases , 5-Metilcitosina/metabolismo , Animais , Metilação de DNA , Dioxigenases/genética , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário/genética , Camundongos
3.
Artigo em Inglês | MEDLINE | ID: mdl-39186167

RESUMO

There is a long-standing lack of learner satisfaction with quality and quantity of feedback in health professions education (HPE) and training. To address this, university and training programmes are increasingly using technological advancements and data analytic tools to provide feedback. One such educational technology is the Learning Analytic Dashboard (LAD), which holds the promise of a comprehensive view of student performance via partial or fully automated feedback delivered to learners in real time. The possibility of displaying performance data visually, on a single platform, so users can access and process feedback efficiently and constantly, and use this to improve their performance, is very attractive to users, educators and institutions. However, the mainstream literature tends to take an atheoretical and instrumentalist view of LADs, a view that uncritically celebrates the promise of LAD's capacity to provide a 'technical fix' to the 'wicked problem' of feedback in health professions education. This paper seeks to recast the discussion of LADs as something other than a benign material technology using the lenses of Miller and Rose's technologies of government and Barry's theory of Technological Societies, where such technical devices are also inherently agentic and political. An examination of the purpose, design and deployment of LADs from these theoretical perspectives can reveal how these educational devices shape and govern the HPE learner body in different ways, which in turn, may produce a myriad of unintended- and ironic- effects on the feedback process. In this Reflections article we wish to encourage health professions education scholars to examine the practices and consequences thereof of the ever-expanding use of LADs more deeply and with a sense of urgency.

4.
J Eur Acad Dermatol Venereol ; 34(3): 624-632, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31494973

RESUMO

BACKGROUND: Recent evidence suggests melasma to be a photoaging disorder. Triple combination creams (TCC: fluocinolone acetonide 0.01%, hydroquinone 4% and tretinoin 0.05%) remain the gold standard treatment. Picosecond alexandrite laser treatment using a diffractive lens array (DLA) has been identified to be effective for improving photoaging conditions. OBJECTIVE: We aimed to compare the efficacy and tolerance of the picosecond alexandrite laser with those of DLA and TCC in female Asian patients with melasma. METHODS: Twenty-nine patients were randomly assigned to group A1 (3 laser sessions at 4-week intervals), A2 (5 laser sessions at 4-week intervals) or B (TCC daily for at least 8 weeks and then tapered until the final evaluation). The Melasma Area, Severity Index (MASI) score and VISIA were assessed at baseline, week 12 and week 20. By week 20, the follow-up periods for groups A1 and A2 were 3 months and 1 month, respectively. RESULTS: Nine, 11 and 6 participants in groups A1, A2 and B completed the study, respectively. MASI scores were significantly improved in all 3 groups at weeks 12 and 20. In groups A1, A2 and B, the improvement rates at week 20 were 53%, 38% and 50%, respectively. VISIA® analysis additionally revealed a significant improvement in spots, porphyria, pores and brown spots after 3 laser sessions (P < 0.05). Group A2 showed greater improvements than group A1 in terms of spots, wrinkles and pores; however, only red areas were significantly different (P < 0.001). All side-effects in the 3 groups were transient and gradually subsided after 1-3 months. CONCLUSION: Picosecond alexandrite laser treatment using DLA showed comparable efficacy with TCC for the treatment of melasma. Improvements in texture, spots, wrinkles and pores were observed in the laser groups. Patients with melasma lesions that exhibit telangiectasia may benefit from additional laser treatment sessions.


Assuntos
Fluocinolona Acetonida/administração & dosagem , Hidroquinonas/administração & dosagem , Lasers de Estado Sólido/uso terapêutico , Melanose/tratamento farmacológico , Melanose/cirurgia , Tretinoína/administração & dosagem , Adulto , Povo Asiático , Terapia Combinada , Combinação de Medicamentos , Feminino , Humanos , Pessoa de Meia-Idade , Pomadas , Estudos Prospectivos , Método Simples-Cego , Resultado do Tratamento
5.
Phys Rev Lett ; 123(18): 181301, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31763885

RESUMO

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

7.
Neuropathol Appl Neurobiol ; 44(7): 673-686, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29423915

RESUMO

AIMS: Sensory nerve degeneration and consequent abnormal sensations are the earliest and most prevalent manifestations of familial amyloid polyneuropathy (FAP) due to amyloidogenic transthyretin (TTR). FAP is a relentlessly progressive degenerative disease of the peripheral nervous system. However, there is a lack of mouse models to replicate the early neuropathic manifestations of FAP. METHODS: We established human TTR knock-in mice by replacing one allele of the mouse Ttr locus with human wild-type TTR (hTTRwt ) or human TTR with the A97S mutation (hTTRA97S ). Given the late onset of neuropathic manifestations in A97S-FAP, we investigated nerve pathology, physiology, and behavioural tests in these mice at two age points: the adult group (8 - 56 weeks) and the ageing group (> 104 weeks). RESULTS: In the adult group, nerve profiles, neurophysiology and behaviour were similar between hTTRwt and hTTRA97S mice. By contrast, ageing hTTRA97S mice showed small fibre neuropathy with decreased intraepidermal nerve fibre density and behavioural signs of mechanical allodynia. Furthermore, significant reductions in sural nerve myelinated nerve fibre density and sensory nerve action potential amplitudes in these mice indicated degeneration of large sensory fibres. The unaffected motor nerve physiology replicated the early symptoms of FAP patients, that is, sensory nerves were more vulnerable to mutant TTR than motor nerves. CONCLUSIONS: These results demonstrate that the hTTRA97S mouse model develops sensory nerve pathology and corresponding physiology mimicking A97S-FAP and provides a platform to develop new therapies for the early stage of A97S-FAP.


Assuntos
Neuropatias Amiloides Familiares/patologia , Degeneração Neural/patologia , Pré-Albumina/genética , Células Receptoras Sensoriais/patologia , Neuropatias Amiloides Familiares/genética , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Degeneração Neural/genética
8.
Mol Cell ; 38(6): 789-802, 2010 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-20620952

RESUMO

Most metazoan microRNA (miRNA) target sites have perfect pairing to the seed region, located near the miRNA 5' end. Although pairing to the 3' region sometimes supplements seed matches or compensates for mismatches, pairing to the central region has been known to function only at rare sites that impart Argonaute-catalyzed mRNA cleavage. Here, we present "centered sites," a class of miRNA target sites that lack both perfect seed pairing and 3'-compensatory pairing and instead have 11-12 contiguous Watson-Crick pairs to the center of the miRNA. Although centered sites can impart mRNA cleavage in vitro (in elevated Mg(2+)), in cells they repress protein output without consequential Argonaute-catalyzed cleavage. Our study also identified extensively paired sites that are cleavage substrates in cultured cells and human brain. This expanded repertoire of cleavage targets and the identification of the centered site type help explain why central regions of many miRNAs are evolutionarily conserved.


Assuntos
MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Regiões 3' não Traduzidas , Animais , Pareamento de Bases , Sequência de Bases , Encéfalo/metabolismo , Cátions Bivalentes , Sequência Conservada , Perfilação da Expressão Gênica , Células HeLa , Humanos , Magnésio/metabolismo , Camundongos , RNA de Cadeia Dupla/metabolismo
9.
Genes Dev ; 24(10): 992-1009, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20413612

RESUMO

MicroRNAs (miRNAs) are small regulatory RNAs that derive from distinctive hairpin transcripts. To learn more about the miRNAs of mammals, we sequenced 60 million small RNAs from mouse brain, ovary, testes, embryonic stem cells, three embryonic stages, and whole newborns. Analysis of these sequences confirmed 398 annotated miRNA genes and identified 108 novel miRNA genes. More than 150 previously annotated miRNAs and hundreds of candidates failed to yield sequenced RNAs with miRNA-like features. Ectopically expressing these previously proposed miRNA hairpins also did not yield small RNAs, whereas ectopically expressing the confirmed and newly identified hairpins usually did yield small RNAs with the classical miRNA features, including dependence on the Drosha endonuclease for processing. These experiments, which suggest that previous estimates of conserved mammalian miRNAs were inflated, provide a substantially revised list of confidently identified murine miRNAs from which to infer the general features of mammalian miRNAs. Our analyses also revealed new aspects of miRNA biogenesis and modification, including tissue-specific strand preferences, sequential Dicer cleavage of a metazoan precursor miRNA (pre-miRNA), consequential 5' heterogeneity, newly identified instances of miRNA editing, and evidence for widespread pre-miRNA uridylation reminiscent of miRNA regulation by Lin28.


Assuntos
Genes/genética , Genoma/genética , MicroRNAs/genética , Animais , Linhagem Celular , Perfilação da Expressão Gênica , Humanos , Sequências Repetidas Invertidas/genética , Camundongos , MicroRNAs/biossíntese , MicroRNAs/metabolismo , Ribonuclease III/metabolismo
10.
J Oral Rehabil ; 45(3): 240-249, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29314191

RESUMO

Current bibliometric analyses of the evolving trends in research scope category across different time periods using the H-classics method in implantology are considerably limited. The purpose of this study was to identify the classic articles in implantology to analyse bibliometric characteristics and associated factors in implantology for the past four decades. H-Classics in implantology were identified within four time periods between 1977 and 2016, based on the h-index from the Scopus® database. For each article, the principal bibliometric parameters of authorship, geographic origin, country origin, and institute origin, collaboration, centralisation, article type, scope of study and other associated factors were analysed in four time periods. A significant increase in mean numbers of authors per H-Classics was found across time. Both Europe and North America were the most productive region/country and steadily dominated this field in each time period. Collaborations of author, internationally and inter-institutionally had significantly increased across time. A significant decentralisation in authorships, institutes and journals was noted in past four decades. The journal of Clinical Oral Implant Researches has raised its importance for almost 30 years (1987-2016). Research on Complications, peri-implant infection/pathology/therapy had been increasing in production throughout each period. This is the first study to evaluate research trends in implantology in the past 40 years using the H-classics method, which through analysing via principle bibliometric characteristics reflected a historical perspective on evolutionary mainstream in the field. Prominence of research regarding complications may forecast innovative advancements in future.


Assuntos
Pesquisa Biomédica , Implantação Dentária , Periodontia , Editoração/normas , Bibliometria , Bases de Dados Factuais , Implantes Dentários , Humanos
12.
Psychol Med ; 46(6): 1225-38, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26744120

RESUMO

BACKGROUND: The relationship between white-matter tracts and executive functions (EF) in attention deficit hyperactivity disorder (ADHD) has not been well studied and previous studies mainly focused on frontostriatal (FS) tracts. The authors explored the microstructural property of several fibre tracts hypothesized to be involved in EF, to correlate their microstructural property with EF, and to explore whether such associations differ between ADHD and typically developing (TD) youths. METHOD: We assessed 45 youths with ADHD and 45 individually matched TD youths with a computerized test battery for multiple dimensions of EF. From magnetic resonance imaging, FS tract, superior longitudinal fasciculus (SLF), arcuate fasciculus (AF) and cingulum bundle (CB) were reconstructed by diffusion spectrum imaging tractography. The generalized fractional anisotropy (GFA) values of white-matter tracts were computed to present microstructural property of each tract. RESULTS: We found lower GFA in the left FS tract, left SLF, left AF and right CB, and poorer performance in set-shifting, sustained attention, cognitive inhibition and visuospatial planning in ADHD than TD. The ADHD and TD groups demonstrated different association patterns between EF and fibre tract microstructural property. Most of the EF were associated with microstructural integrity of the FS tract and CB in TD youths, while with that of the FS tract, SLF and AF in youths with ADHD. CONCLUSIONS: Our findings support that the SLF, AF and CB also involve in a wide range of EF and that the main fibre tracts involved in EF are different in youths with ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Atenção , Função Executiva , Rede Nervosa/fisiopatologia , Vias Neurais/fisiopatologia , Substância Branca/fisiopatologia , Adolescente , Anisotropia , Estudos de Casos e Controles , Criança , Imagem de Tensor de Difusão , Feminino , Humanos , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Taiwan
13.
J Appl Microbiol ; 121(5): 1242-1253, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27541959

RESUMO

AIMS: This study investigated the influence of two microbial inoculants; Lactobacillus formosensis and Lactobacillus buchneri on fermentation quality, chemical composition, aerobic stability and in vitro ruminal biological activity of condensed tannins in sweet potato vines silage. METHODS AND RESULTS: Sweet potato vines were ensiled for 28 and 60 days; without inoculant (CON), with Lact. buchneri (LB) or with Lact. formosensis (LF), both inoculants applied to achieve 1 × 106  CFU g-1 fresh forage. Lactobacillus formosensis silage had lower pH and higher lactic acid than all treatments. Yeasts and moulds were not detected in LB silage after ensiling. Lactobacillus buchneri silage was more aerobically stable than all treatments, whereas LF was more stable than CON silage. In vitro ruminal biological activity of condensed tannins was lower in microbial-inoculated silages than CON after ensiling. CONCLUSION: Lactobacillus formosensis improved fermentability by reducing silage pH and improved aerobic stability by producing more propionate, which inhibited yeast activity. Lactobacillus buchneri improved aerobic stability of the silage by producing more acetate. Both strains effectively reduced the antinutritional effect of condensed tannins after ensiling. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus formosensis has the potential to be used as a silage inoculant because of its ability to improve fermentability and aerobic stability in sweet potato vines silage.


Assuntos
Fermentação , Ipomoea batatas , Lactobacillus/fisiologia , Proantocianidinas/metabolismo , Silagem/microbiologia , Aerobiose , Ácido Láctico/metabolismo , Silagem/análise , Leveduras/isolamento & purificação
14.
Phys Rev Lett ; 114(10): 101301, 2015 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-25815919

RESUMO

We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 µK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r_{0.05}<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.

15.
Allergy ; 70(5): 568-75, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25727950

RESUMO

BACKGROUND: Sequential human herpes virus (HHV) reactivation is well known in drug reaction with eosinophilia and systemic symptom (DRESS), but such a phenomenon has seldom studied in other types of cutaneous adverse drug reactions (cADRs). Moreover, the association between viral reactivations and cytokine or chemokine changes is largely unknown. We aimed to evaluate the viral reactivation rates of HHV-6, HHV-7, Epstein-Barr virus (EBV), and cytomegalovirus (CMV) in different cADRs and their impacts on clinical prognosis. Cytokine and chemokine changes with viral reactivations were also examined. METHODS: A prospective study was conducted to monitor the viral statuses of patients with different cADRs by polymerase chain reaction and serum-specific antibody titers. Changes in plasma cytokine and chemokine levels were also evaluated by sequential blood samples. RESULTS: Among the various cADRs, HHV-6 reactivation was only observed in DRESS, but EBV and CMV could be detected in other cADRs. Many proinflammatory cytokines and chemokines, including interleukin (IL)-1ß, IL-2, IL-6, interferon-γ, tumor necrosis factor-α, were significantly lower in DRESS patients with HHV-6 reactivation when compared to those without HHV-6 reactivation. In addition, these mediators were significantly lower before and during HHV-6 reactivation, compared to cytokine levels after HHV-6 reactivation in the same patient. CONCLUSION: HHV-6 reactivation was only observed in DRESS patients, not in any other cADR. In DRESS patients, some proinflammatory cytokines were significantly lower before or during HHV-6 reactivation.


Assuntos
Citocinas/sangue , Toxidermias/virologia , Infecções por Herpesviridae/virologia , Ativação Viral/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA Viral/análise , Toxidermias/imunologia , Síndrome de Hipersensibilidade a Medicamentos/imunologia , Síndrome de Hipersensibilidade a Medicamentos/virologia , Feminino , Herpesviridae/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Prospectivos , Adulto Jovem
16.
Mol Hum Reprod ; 20(6): 526-37, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24598112

RESUMO

Hypoxia inducible factor 2α (HIF-2α) is critical for primordial germ cell (PGC) survival as knockout of HIF-2α (HIF-2α(-/-)) decreases both expression of Oct-4 and PGC number in genital ridge. Hypoxia is known to stabilize HIF-2α protein from proteasomal degradation. However, little is known about the hypoxia-associated endocrinal signaling in HIF-2α expression. The current work demonstrates a role for an endocrine insulin-like growth factor-I receptor (IGF-IR)-PI3K/Akt-mTOR-HIF-2α regulatory loop in the proliferation and Oct-4 maintenance of PGC-like alkaline phosphatase positive mouse germline stem cells (AP(+)GSCs). We found that hypoxia greatly increased the cell proliferation and the levels of nuclear Oct-4/HIF-2α protein of AP(+)GSCs. The hypoxic-AP(+)GSCs presented stronger stemness ability for germ cell differentiation than normoxic, with expressions of c-KIT (differentiation germ cell marker), VASA (differentiation germ cell marker) and SCP3 (meiotic marker) using a renal capsule transplantation assay. Meanwhile, hypoxia significantly increased the expression levels of secreted-IGF-I and IGF-IR. The IGF-I dose dependently increased the HIF-2α expression levels in AP(+)GSCs; and, the inhibition of IGF-IR by RNA interference (shIGF-IR) or LY294002 (PI3K inhibitor)/Rapamycin (mTOR inhibitor) effectively suppressed the IGF-I- and/or hypoxia-induced HIF-2α and Oct-4 expression, suggesting that the IGF-IR and its downstream Akt/mTOR signaling are involved in the IGF-I/hypoxia effects. Additionally, knockdown of HIF-2α dramatically suppressed Oct-4 and IGF-IR protein levels in AP(+)GSC cells. In conclusion, the present study demonstrates a regulatory loop of IGF-IR-PI3K/Akt-mTOR-HIF-2α in proliferation and Oct-4 maintenance of PGC-like AP(+)GSCs under hypoxia. This finding provides insights into the niche endocrinology underlying early germ cell development.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Retroalimentação Fisiológica , Células Germinativas/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Receptor IGF Tipo 1/genética , Animais , Animais Recém-Nascidos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipóxia Celular/genética , Proliferação de Células , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento , Células Germinativas/citologia , Masculino , Camundongos , Fator 3 de Transcrição de Octâmero/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Receptor IGF Tipo 1/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Testículo/citologia , Testículo/metabolismo
17.
Nature ; 455(7217): 1193-7, 2008 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-18830242

RESUMO

In bilaterian animals, such as humans, flies and worms, hundreds of microRNAs (miRNAs), some conserved throughout bilaterian evolution, collectively regulate a substantial fraction of the transcriptome. In addition to miRNAs, other bilaterian small RNAs, known as Piwi-interacting RNAs (piRNAs), protect the genome from transposons. Here we identify small RNAs from animal phyla that diverged before the emergence of the Bilateria. The cnidarian Nematostella vectensis (starlet sea anemone), a close relative to the Bilateria, possesses an extensive repertoire of miRNA genes, two classes of piRNAs and a complement of proteins specific to small-RNA biology comparable to that of humans. The poriferan Amphimedon queenslandica (sponge), one of the simplest animals and a distant relative of the Bilateria, also possesses miRNAs, both classes of piRNAs and a full complement of the small-RNA machinery. Animal miRNA evolution seems to have been relatively dynamic, with precursor sizes and mature miRNA sequences differing greatly between poriferans, cnidarians and bilaterians. Nonetheless, miRNAs and piRNAs have been available as classes of riboregulators to shape gene expression throughout the evolution and radiation of animal phyla.


Assuntos
Evolução Molecular , MicroRNAs/genética , RNA Interferente Pequeno/genética , Anêmonas-do-Mar/genética , Animais , Sequência de Bases , Células Eucarióticas/metabolismo , Regulação da Expressão Gênica , Humanos , Filogenia , Análise de Sequência
18.
Hum Brain Mapp ; 34(8): 1946-55, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22451240

RESUMO

Threatening stimuli have been found to modulate visual processes related to perception and attention. The present functional magnetic resonance imaging (fMRI) study investigated whether threat modulates visual object recognition of man-made and naturally occurring categories of stimuli. Compared with nonthreatening pictures, threatening pictures of real items elicited larger fMRI BOLD signal changes in medial visual cortices extending inferiorly into the temporo-occipital (TO) "what" pathways. This region elicited greater signal changes for threatening items compared to nonthreatening from both the natural-occurring and man-made stimulus supraordinate categories, demonstrating a featural component to these visual processing areas. Two additional loci of signal changes within more lateral inferior TO areas (bilateral BA18 and 19 as well as the right ventral temporal lobe) were detected for a category-feature interaction, with stronger responses to man-made (category) threatening (feature) stimuli than to natural threats. The findings are discussed in terms of visual recognition of processing efficiently or rapidly groups of items that confer an advantage for survival.


Assuntos
Mapeamento Encefálico , Medo/fisiologia , Memória/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Medo/psicologia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Reconhecimento Psicológico , Semântica , Adulto Jovem
19.
Osteoarthritis Cartilage ; 21(4): 589-98, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23333470

RESUMO

OBJECTIVE: Matrix-associated autologous chondrocyte implantation has been used to treat cartilage defects. We developed a biphasic cylindrical osteochondral composite construct for such use, and conducted this study to determine its feasibility for treating osteochondral lesions in human knees. METHOD: Ten patients with symptomatic osteochondral lesions at femoral condyles were treated by replacing pathological tissue with the construct of dl-poly-lactide-co-glycolide, whose lower body was impregnated with ß-tricalcium phosphate and served as osseous phase. The construct had a chamber to load double-minced autologous cartilage, serving as source of chondrocytes. Osteochondral lesion was drill-fashioned a pit of identical dimension as the construct. Chondrocyte-laden construct was press-fit to fill the pit. Postoperative outcome was evaluated using Knee Injury and Osteoarthritis Outcome Score (KOOS) scale up to 24 months. Magnetic resonance image was taken, and sample tissue was collected with second-look arthroscopic needle biopsy at 12 months. Outcome parameters were primarily safety of surgery, and secondarily postoperative change in KOOS and regeneration of hyaline cartilage and cancellous bone. RESULTS: No patient experienced serious adverse events. Postoperative mean KOOS in "symptoms" subscale had not changed significantly from pre-operation until 24 months; whereas those in the other four subscales were significantly higher than pre-operation at 12 and 24 months. Second-look arthroscopy showed completely filled grafted sites, with regenerate cartilaginous surfaces flushed with surrounding native joint surface. Microscopically, regenerated cartilage appeared hyaline. CONCLUSION: This novel construct for chondrocyte implantation is safe for surgical application in knee. It repairs osteochondral lesions of femoral condyles by successful regeneration of hyaline cartilage.


Assuntos
Condrócitos/transplante , Traumatismos do Joelho/cirurgia , Articulação do Joelho/cirurgia , Alicerces Teciduais , Adulto , Artroscopia , Regeneração Óssea/fisiologia , Cartilagem Articular/lesões , Cartilagem Articular/patologia , Cartilagem Articular/fisiologia , Estudos de Viabilidade , Feminino , Humanos , Articulação do Joelho/patologia , Articulação do Joelho/fisiologia , Ácido Láctico , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Osteocondrite Dissecante/cirurgia , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Complicações Pós-Operatórias , Regeneração , Índice de Gravidade de Doença , Engenharia Tecidual/métodos , Resultado do Tratamento , Adulto Jovem
20.
Phys Rev Lett ; 111(6): 064501, 2013 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-23971577

RESUMO

We use confocal microscopy to directly visualize the spatial fluctuations in fluid flow through a three-dimensional porous medium. We find that the velocity magnitudes and the velocity components both along and transverse to the imposed flow direction are exponentially distributed, even with residual trapping of a second immiscible fluid. Moreover, we find pore-scale correlations in the flow that are determined by the geometry of the medium. Our results suggest that despite the considerable complexity of the pore space, fluid flow through it is not completely random.

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