Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Phys Rev Lett ; 131(5): 053602, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595227

RESUMO

The chiral surface states of Weyl semimetals have an open Fermi surface called a Fermi arc. At the interface between two Weyl semimetals, these Fermi arcs are predicted to hybridize and alter their connectivity. In this Letter, we numerically study a one-dimensional (1D) dielectric trilayer grating where the relative displacements between adjacent layers play the role of two synthetic momenta. The lattice emulates 3D crystals without time-reversal symmetry, including Weyl semimetal, nodal line semimetal, and Chern insulator. Besides showing the phase transition between Weyl semimetal and Chern insulator at telecom wavelength, this system allows us to observe the Fermi arc reconstruction between two Weyl semimetals, confirming the theoretical predictions.

2.
Br Poult Sci ; 63(4): 535-540, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35068254

RESUMO

1. The objective of the study was to demonstrate that Bacillus subtilis strain VL28 (BS-VL28), a novel strain isolated from faeces of healthy chicken, has potential as a probiotic.2. The study evaluated the probiotic properties of BS-VL28 and the effects of dietary supplementation of this strain on growth performance and mortality in chickens challenged with Salmonella enterica CT01.3. BS-VL28 exhibited a specific inhibitory activity against Escherichia coli CT11, Salmonella enterica CT01, Staphylococcus spp. CT21 and Streptococcus spp. CT31.4. BS-VL28 also showed an auto-aggregation percentage of 82%, co-aggregation activity greater than 60%, high tolerance to low pH (<2.0) under the presence of 0.05% bile salts. However, the results from the antibiotic susceptibility tests demonstrated that this strain was sensitive to erythromycin, gentamycin, doxycycline, norfloxacin, oxytetracycline, trimethoprim-sulfamethoxazole, enrofloxacin but was intermediate to neomycin.5. Inclusion of probiotic (5 g BS-VL28 (107 CFU/g) per kg of feed to diet of challenged chickens showed better performance and feed conversion rates (FCR). There was a significant decrease (p < 0.05) in mortality in the probiotic-treated group compared to the control and antibiotic-treated groups.6. From these results, BS-VL28 could potentially function as a probiotic for broilers.


Assuntos
Galinhas , Probióticos , Ração Animal/análise , Animais , Antibacterianos/farmacologia , Bacillus subtilis/fisiologia , Galinhas/fisiologia , Dieta/veterinária , Escherichia coli , Fezes , Probióticos/farmacologia
3.
Balkan J Med Genet ; 24(1): 57-66, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34447660

RESUMO

The phenome of E-cadherin gene methylation and the expression of latent membrane protein 1 (LMP-1) gene are associated with nasopharyngeal carcinoma (NPC). In order to determine whether cooperative LMP-1 expression or methylation of E-cadherin could serve as the potential molecule biomarker target for diagnosis and therapy of NPC, a case-control study including 93 NPC biopsy samples and 100 non cancerous nasopharyngeal swab samples were examined, as well as the strength of association among them by the quantitative polymerase chain reaction (qPCR) and nested-methylation-specific PCR methods. The significantly higher frequency of LMP-1 expression and E-cadherin methylation in NPC biopsy samples, accounting for 76.34 and 73.12%, respectively, compared to non cancerous samples, accounting for 0.00 and 30.00%, respectively, were observed. The significant correlation between the LMP-1 expression and E-cadherin methylation in NPC samples was reported. In detail, in the stage IV of NPC, in case of LMP-1-positive samples, 35 of 37 samples (accounting for 94.60%) were positive for methylation of E-cadherin. It was demonstrated that cooperative LMP-1 expression and E-cadherin gene methylation could serve as a molecular biomarker in NPC.

4.
J Eur Acad Dermatol Venereol ; 28(6): 689-99, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24033440

RESUMO

BACKGROUND: Keloids are an overgrowth of fibrotic tissue outside the original boundaries of an injury and occur secondary to defective wound healing. Keloids often have a functional, aesthetic, or psychosocial impact on patients as highlighted by quality-of-life studies. OBJECTIVES: Our goal is to provide clinicians and scientists an overview of the data available on laser and light-based therapies for treatment of keloids, and highlight emerging light-based therapeutic technologies and the evidence available to support their use. METHODS: We employed the following search strategy to identify the clinical evidence reported in the biomedical literature: in November 2012, we searched PubMed.gov, Ovid MEDLINE, Embase and Cochrane Reviews (1980-present) for published randomized clinical trials, clinical studies, case series and case reports related to the treatment of keloids. The search terms we utilized were 'keloid(s)' AND 'laser' OR 'light-emitting diode' (LED) OR 'photodynamic therapy' (PDT) OR 'intense pulsed light' OR 'low level light' OR 'phototherapy.' RESULTS: Our search yielded 347 unique articles. Of these, 33 articles met our inclusion and exclusion criteria. CONCLUSION: We qualitatively conclude that laser and light-based treatment modalities may achieve favourable patient outcomes. Clinical studies using CO2 laser are more prevalent in current literature and a combination regimen may be an adequate ablative approach. Adding light-based treatments, such as LED phototherapy or PDT, to laser treatment regimens may enhance patient outcomes. Lasers and other light-based technology have introduced new ways to manage keloids that may result in improved aesthetic and symptomatic outcomes and decreased keloid recurrence.


Assuntos
Queloide/terapia , Terapia a Laser , Fototerapia , Humanos , Terapia a Laser/métodos
5.
Perfusion ; 29(2): 153-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23899441

RESUMO

Sickle cell anemia and thalassemia are hemoglobinopathies rarely encountered in the United States. Compounded with congenital heart disease, patients with sickle cell disease (SCD) requiring cardiopulmonary bypass and open-heart surgery represent the proverbial "needle in the haystack". As such, there is some trepidation on the part of clinicians when these patients present for complex cardiac surgery. SCD is an autosomal, recessive condition that results from a single nucleotide polymorphism in the ß-globin gene. Hemoglobin SS molecules (HgbSS) with this point mutation can polymerize under the right conditions, stiffening the erythrocyte membrane and distorting the cellular structure to the characteristic sickle shape. This shape change alters cellular transit through the microvasculature. As a result, circumstances such as hypoxia, hypothermia, acidosis or diminished blood flow can lead to aggregation, vascular occlusion and thrombosis. Chronically, SCD can give rise to multiorgan damage secondary to hemolysis and vascular obstruction. This review and case study details an 11-year-old African-American male with known SCD who presented to the cardiothoracic surgical service with congenital heart disease consisting of an anomalous, intramural right coronary artery arising from the left coronary sinus for surgical consultation and subsequent surgical correction. This case report will include a review of the pathophysiology and current literature regarding preoperative, intraoperative and postoperative management of SCD patients.


Assuntos
Anemia Falciforme , Procedimentos Cirúrgicos Cardíacos/métodos , Cardiopatias Congênitas , Assistência Perioperatória/métodos , Anemia Falciforme/complicações , Anemia Falciforme/fisiopatologia , Anemia Falciforme/cirurgia , Criança , Vasos Coronários/fisiopatologia , Vasos Coronários/cirurgia , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/fisiopatologia , Cardiopatias Congênitas/cirurgia , Humanos , Masculino
6.
Eur Rev Med Pharmacol Sci ; 27(19): 9091-9100, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37843323

RESUMO

OBJECTIVE: Spondylolisthesis is one of the common causes of spinal pain. There is currently a lack of studies on the correlation between magnetic resonance imaging (MRI) and clinical symptoms of patients with spondylolisthesis. This study is aimed to find the correlation between clinical symptoms of L4/L5, L5/S1 lumbar spondylolisthesis, and imaging parameters on MRI. PATIENTS AND METHODS: A retrospective study on 100 patients who were diagnosed with lumbar spondylolisthesis at the L4/L5, L5/S1 levels from August 2022 to February 2023. Parameters on MRI are measured the cross-sectional area of the dural sac (DSA), the cross-sectional area of the spinal canal (SCA), the ligamentum flavum cross-sectional area (LFA), and ligamentum flavum thickness (LFT), anterior-posterior diameter (APD), sliding distance (SD) at the spondylolisthesis level. Clinical symptoms were investigated according to the Visual Analogue Scale (VAS) for grading of pain and the subjective disability was assessed by the Oswestry Disability Index (ODI). RESULTS: There was no statistically significant difference between SD, APD, SCA, DSA, LFA, and LFT between the mild and moderate pain VAS and severe pain VAS groups. No correlation was found between VAS and SD, APD, SCA, DSA, LFA, and LFT. There is a negative correlation between ODI and APD, SCA, and DSA. The statistically significant difference in APD, SCA, and DSA indexes in the two groups with mild/moderate disability (ODI ≤40%) and the group with severe disability (ODI >40%). CONCLUSIONS: A higher DSA and SCA, APD are associated with lower ODI. Decreased APD, SCA, and DSA are all suggestive of decreased spinal function. However, the MRI findings did not correlate with the patient's clinical pain level.


Assuntos
Dor Lombar , Fusão Vertebral , Espondilolistese , Humanos , Espondilolistese/diagnóstico por imagem , Estudos Retrospectivos , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Fusão Vertebral/métodos , Resultado do Tratamento
7.
Eur Rev Med Pharmacol Sci ; 27(10): 4428-4435, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37259723

RESUMO

OBJECTIVE: This study aims to evaluate the value of multidetector computed tomography (MDCT) in detecting the location of gastroduodenal perforation. PATIENTS AND METHODS: This cross-sectional descriptive study was conducted with 47 patients who underwent contrast-enhancing MDCT and were diagnosed with gastroduodenal perforation during surgery between July 2021 and June 2022. Radiologic findings included pneumoperitoneum (distribution and quantity) and analyzed the image findings for localizing the site of gastroduodenal perforation. RESULTS: Pneumoperitoneum was the most common finding [95.74% (45 out of 47 patients)]. Regarding air distribution, the sensitivity (Se) and negative predictive value (NPV) of abdominal free air and supramesocolic free air were the highest (100% for both). The accuracy (Acc) of supramesocolic free air was the highest (93.6%), followed by abdominal free air (89.4%). Subphrenic free air also had a high Acc value (89.4%), with Se, specificity (Sp), and positive predictive value (PPV) being 90%, 85,7%, and 97.3%, respectively. The Sp PPV of falciform ligament/ligamentum teres sign, and periportal free air were also high (100% for both). In contrast, retroperitoneal free air was valuable in determining retroperitoneal duodenal perforation with an Sp, Se of 100%, and Acc of 89.4%. The thickness of abdominal free air was ≥5.5 mm, suggesting gastroduodenal perforation with a Se, Sp, PPV, NPV, and Acc of 82.5%, 100%, 100%, 50%, and 85.1%, respectively. CONCLUSIONS: Subphrenic free air, periportal free air, falciform ligament sign, and the air above transverse mesocolon were correlated to gastric and duodenal bulb perforation. Retroperitoneal air indicates the perforation at the retroperitoneal duodenum. The thickness of abdominal free air ≥5.5 mm indicates gastric and duodenal bulb perforation.


Assuntos
Úlcera Duodenal , Úlcera Péptica Perfurada , Pneumoperitônio , Úlcera Gástrica , Humanos , Tomografia Computadorizada Multidetectores , Pneumoperitônio/diagnóstico por imagem , Estudos Transversais , Úlcera Péptica Perfurada/cirurgia , Sensibilidade e Especificidade , Estudos Retrospectivos
8.
Eur Rev Med Pharmacol Sci ; 27(8): 3489-3499, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37140298

RESUMO

OBJECTIVE: This retrospective study evaluated the diagnostic efficacy of magnetic resonance imaging (MRI) for identifying acute appendicitis during pregnancy. PATIENTS AND METHODS: This retrospective study enrolled a total of 46 pregnant patients with clinically suspected acute appendicitis who underwent 1.5 T MRI and received a final pathological diagnosis. We evaluated the imaging characteristics associated with patients diagnosed with acute appendicitis, including the appendix diameter, the appendix wall thickness, intra-appendiceal fluid collection, and peri-appendiceal fat infiltration. A bright appendix on T1-weighted 3-dimensional imaging was identified as a negative sign for appendicitis. RESULTS: Peri-appendiceal fat infiltration had the highest specificity of 97.1% for diagnosing acute appendicitis, whereas increasing appendiceal diameter had the highest sensitivity of 91.7%. The cut-off values for increasing appendiceal diameter and appendiceal wall thickness were 6.55 mm and 2.7 mm, respectively. Using these cut-off values, appendiceal diameter had a sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of 91.7%, 91.2%, 78.4%, and 96.9%, respectively, whereas these values for appendiceal wall thickness were 75.0%, 91.2%, 75.0%, and 91.2%. The combination of increasing appendiceal diameter and appendiceal wall thickness resulted in an area under the receiver operating characteristic curve value of 0.958 with Se, Sp, PPV, and NPV values of 75.0%, 100.0%, 100.0%, and 91.9%, respectively. CONCLUSIONS: All five MRI signs examined in this study had significant diagnostic value for detecting acute appendicitis during pregnancy, with p-values <0.01. The combined use of increasing appendiceal diameter and appendiceal wall thickness displayed the excellent ability to diagnose acute appendicitis in pregnant women.


Assuntos
Apendicite , Humanos , Feminino , Gravidez , Apendicite/diagnóstico por imagem , Apendicite/patologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Diagnóstico Diferencial , Imageamento por Ressonância Magnética/métodos , Doença Aguda
9.
Biomed Phys Eng Express ; 8(5)2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35835081

RESUMO

Microwave imaging (MWI) systems are being investigated for breast cancer diagnostics as an alternative to conventional x-ray mammography and breast ultrasound. This work aims at a next generation of tissue-mimicking phantoms modelling the temperature-dependent dielectric properties of breast tissue over a large frequency bandwidth. Such phantoms can be used to develop a novel kind of MWI systems that exploit the temperature-dependent permittivity of tissue as a natural contrast agent. Due to the higher water content in tumor tissue, a temperature increase leads to a different change in the complex permittivity compared to surrounding tissue. This will generate a tumor dominated scattering response when the overall tissue temperature increases by a few degrees, e.g. through the use of microwave hyperthermia systems. In that case a differential diagnostic image can be calculated between microwave measurements at reference (around 37 °C) and elevated temperature conditions. This work proposes the design and characterization of agar-oil-glycerin phantoms for fatty, glandular, skin and tumor tissue. The characterization includes measurements with an open-ended coaxial probe and a network analyzer for the frequency range from 50 MHz to 20 GHz in a temperature-controlled environment covering the temperature range from 25 °C to 46 °C. The phantoms show an unique temperature response over the considered frequency bandwidth leading to significant changes in the real and imaginary part of the complex permittivity. Comparative studies with porcine skin and fat tissue show a qualitative agreement.


Assuntos
Micro-Ondas , Pele , Animais , Imagens de Fantasmas , Compostos Radiofarmacêuticos , Suínos , Temperatura , Água
10.
Eur Rev Med Pharmacol Sci ; 26(23): 8823-8831, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36524501

RESUMO

OBJECTIVE: This study determined the diagnostic value of diffusion tensor imaging (DTI) sequences using fractional anisotropy (FA) and mean diffusivity (MD) for discriminating glioblastoma (GBM) from solitary brain metastases (SBM) using 3 Tesla magnetic resonance imaging (MRI). PATIENTS AND METHODS: A retrospective study was conducted, including 40 patients who underwent biopsy or surgery and received a histological diagnosis of GBM or SBM between August 2020 and December 2021. All preoperative examinations were performed on 3 Tesla MRI using conventional and DTI sequences. Three regions of interest (ROIs) were placed to measure a solid tumor component, peritumoral edema, and the opposite normal white matter to evaluate FA and MD values. Parametric and nonparametric statistical tests were used to determine differences between GBM and SBM. The diagnostic value of significantly different parameters between the two tumor entities was analyzed using the receiver operating characteristic (ROC) curve. RESULTS: The FA value for peritumoral edema (eFA) in GBM cases was significantly larger than that in SBM cases (p < 0.05), with no significant difference in MD values. The FA and MD values for the solid tumor component (sFA and sMD, respectively) and the ratio of the sFA value to the FA value of the opposite normal white matter (rFAs/n) in GBM cases were significantly larger than those in SBM cases (p < 0.05). Combining the sFA and sMD values provided the highest area under the ROC curve (AUC) value of 0.96, with a sensitivity, specificity, positive predictive value, and negative predictive value of 85.2%, 100%, 85.2%, and 87.1%, respectively, for distinguishing GBM from SBM. CONCLUSIONS: MRI parameters, including sFA, sMD, eFA, and rFAs/n, are useful for differentiating between GBM and SBM. The combination of sFA and sMD may increase the diagnostic performance of MRI for these two tumor entities.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/patologia , Anisotropia , Imagem de Tensor de Difusão/métodos , Estudos Retrospectivos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética
11.
Eur Rev Med Pharmacol Sci ; 26(10): 3577-3584, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35647839

RESUMO

OBJECTIVE: This study determined the diagnostic performance of fluid-attenuated inversion recovery (FLAIR) signal intensity (SI) in discriminating between glioblastoma (GBM) and solitary brain metastasis (SBM). PATIENTS AND METHODS: We recruited 40 patients with a histologically confirmed diagnosis of GBM or SBM who underwent conventional 3 Tesla magnetic resonance imaging before surgery or biopsy between August 2020 and January 2022. Three regions of interest were placed to assess FLAIR SI: the enhancing region (eFLAIR), the peritumoral region (pFLAIR), and the contralateral normal white matter (nFLAIR). The diagnostic performance of significantly different parameters between the two tumor entities was analyzed by receiver operating characteristic (ROC) curve analysis. RESULTS: The pFLAIR SI was significantly lower in GBM than in SBM (p < 0.05). The eFLAIR SI and the SI ratio eFLAIR and nFLAIR (e/nFLAIR) were significantly higher in GBM than in SBM (p < 0.05). On ROC curve analysis, the e/nFLAIR ratio provided the highest area under the curve value of 81%, with a sensitivity of 80.8% and a specificity of 85.7%, for distinguishing between the two tumor types. CONCLUSIONS: The eFLAIR, pFLAIR, and e/nFLAIR parameters are useful for differentiating between GBM and SBM.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Substância Branca , Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Curva ROC , Substância Branca/patologia
12.
Eur Rev Med Pharmacol Sci ; 26(19): 7115-7124, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36263559

RESUMO

OBJECTIVE: Our study investigated magnetic resonance imaging measurements for differentiating cerebellopontine angle (CPA) meningioma from vestibular schwannoma (VS). PATIENTS AND METHODS: This retrospective study compared 36 meningioma and 36 VS patients. The tumor volume (Vtumor) and peritumor edema index (EI) relationship was analyzed. T2-weighted three-dimensional gradient-echo image signal intensity (T23D) and apparent diffusion coefficient (ADC) differentiation cutoff values were defined. Mann-Whitney U test, independent-samples t-test, receiver operating characteristic curve, and Spearman's correlation analyses were applied. RESULTS: Meningioma had higher Vtumor (p=0.009) and EI (p=0.031) values than VS. Meningioma had significantly (p<0.001) lower values than VS for mean ADC (ADCmean: 0.841±0.083×10-3 vs.1.173±0.190×10-3 mm2/s), minimum ADC (ADCmin: 0.716±0.078×10-3 vs.1.045±0.178×10-3 mm2/s), tumor:white matter ADC ratio (rADC: 1.198±0.19 vs. 1.59±0.30), mean T23D (T23Dmean: 142.91±19.9 vs. 218.72±84.73), and tumor:adipose T23D ratio (rT23d: 0.19±0.06 vs. 0.30±0.28) Cutoff, sensitivity (Se), and specificity (Sp) values were ADCmin, 0.856×10-3 mm2/s (Se: 96.6%, Sp: 100%); ADCmean, 0.963×10-3 mm2/s (Se: 96.6%, Sp: 95.5%); rADC, 1.3189 (Se: 93.1%, Sp: 81.8%), T23Dmean (Se: 96.6%, Sp: 100%); rT23D, 0.1951 (Se: 89.7%, Sp: 100%), Vtumor, 14828.65 mm3 (Se: 75.0%, Sp: 66.7%), and EI, 1.1025 (Se: 47.2%, Sp: 100%). CONCLUSIONS: ADCmin, ADCmean, rADC, T23Dmean, rT23D, Vtumor, and EI, effectively discriminated meningioma from VS.


Assuntos
Neoplasias Cerebelares , Ângulo Cerebelopontino , Imageamento por Ressonância Magnética , Neoplasias Meníngeas , Meningioma , Neuroma Acústico , Humanos , Ângulo Cerebelopontino/diagnóstico por imagem , Ângulo Cerebelopontino/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Meníngeas/diagnóstico por imagem , Meningioma/diagnóstico por imagem , Meningioma/patologia , Neuroma Acústico/diagnóstico por imagem , Estudos Retrospectivos
13.
Eur Rev Med Pharmacol Sci ; 26(21): 7938-7948, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36394742

RESUMO

OBJECTIVE: This study investigated the roles of dynamic susceptibility contrast (DSC) perfusion and multivoxel magnetic resonance spectroscopy (MRS) in grading brainstem glioma (BSG). PATIENTS AND METHODS: Our retrospective study comprised 12 patients, including 6 with pathology verified low-grade BSGs and 6 with high-grade BSGs. We examined differences in age, relative cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and the metabolite ratios of choline (Cho)/N-acetyl aspartate (NAA) and Cho/creatine (Cr) between these two groups using the Mann-Whitney U test and Chi-square test. Receiver operating characteristic (ROC) curve analysis was used to establish cutoff values and assess their usefulness in grading BSG. RESULTS: The Cho/NAA metabolite ratio had the strongest preoperative predictive performance for identifying the correct histological grade among BSGs, with an area under the ROC curve (AUC) value of 0.944 (cutoff: 3.88, sensitivity [Se]: 83.3%; specificity [Sp]: 100%), followed by the Cho/Cr ratio (cutoff: 3.08; AUC: 0.917; Se: 83.3%; Sp: 100%), rCBF (cutoff: 3.56, AUC: 0.917; Se: 83.3%; Sp: 100%), rCBV (cutoff: 3.16, AUC: 0.889; Se: 100%; Sp: 66.7%), and age (cutoff: 9.5 years, AUC: 0.889; Se: 100%; Sp: 83.3%). CONCLUSIONS: rCBF and rCBV values comparing solid tumors with the normal brain parenchyma and the metabolite ratios for Cho/NAA and Cho/Cre may serve as useful indices for establishing BSG grading and provide important information when determining treatment planning and prognosis in patients with BSG.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Criança , Neoplasias Encefálicas/metabolismo , Estudos Retrospectivos , Glioma/diagnóstico por imagem , Glioma/metabolismo , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Creatina , Ácido Aspártico , Colina/metabolismo , Perfusão , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/metabolismo
14.
Nat Commun ; 12(1): 4341, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34290244

RESUMO

Some of the highest-transition-temperature superconductors across various materials classes exhibit linear-in-temperature 'strange metal' or 'Planckian' electrical resistivities in their normal state. It is thus believed by many that this behavior holds the key to unlock the secrets of high-temperature superconductivity. However, these materials typically display complex phase diagrams governed by various competing energy scales, making an unambiguous identification of the physics at play difficult. Here we use electrical resistivity measurements into the micro-Kelvin regime to discover superconductivity condensing out of an extreme strange metal state-with linear resistivity over 3.5 orders of magnitude in temperature. We propose that the Cooper pairing is mediated by the modes associated with a recently evidenced dynamical charge localization-delocalization transition, a mechanism that may well be pertinent also in other strange metal superconductors.

15.
Sci Adv ; 7(15)2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33827806

RESUMO

Meiosis is critical to generating oocytes and ensuring female fertility; however, the mechanisms regulating the switch from mitotic primordial germ cells to meiotic germ cells are poorly understood. Here, we implicate intercellular bridges (ICBs) in this state transition. We used three-dimensional in toto imaging to map meiotic initiation in the mouse fetal ovary and revealed a radial geometry of this transition that precedes the established anterior-posterior wave. Our studies reveal that appropriate timing of meiotic entry across the ovary and coordination of mitotic-meiotic transition within a cyst depend on the ICB component Tex14, which we show is required for functional cytoplasmic sharing. We find that Tex14 mutants more rapidly attenuate the pluripotency transcript Dppa3 upon meiotic initiation, and Dppa3 mutants undergo premature meiosis similar to Tex14 Together, these results lead to a model that ICBs coordinate and buffer the transition from pluripotency to meiosis through dilution of regulatory factors.


Assuntos
Meiose , Oócitos , Animais , Proteínas Cromossômicas não Histona , Feminino , Feto , Células Germinativas , Camundongos , Ovário , Fatores de Transcrição/genética
16.
J Nanosci Nanotechnol ; 21(4): 2576-2581, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33500078

RESUMO

Magnetic magnetite (Fe3O4) nanoparticles with average sizes of 5.11, 10.53, and 14.76 nm were synthesized by the chemical co-precipitation method. The surface area of Fe3O4 nanoparticles (average size of 5.11 nm) had the largest value of 167 m²/g. The adsorption capacity for removing arsenic (As(V)) from water at 3 ppm concentration was investigated by atomic absorption spectroscopy. Results showed that the As(V) adsorption capacity of Fe3O4 was dependent on particle size. The maximum absorption efficiency (Hmax) reached 99.02%, the equilibrium time was 30 min; the maximum Langmuir isotherm adsorption capacity was 14.46 mg/g with Fe3O4 nanoparticle an average size of 5 nm. The results indicate that reducing the size of Fe3O4 nanoparticles is a promised way for As(V) ion removal from water and wastewater treatment.

17.
J Cell Biol ; 146(1): 149-64, 1999 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-10402467

RESUMO

Urokinase-type plasminogen activator (uPA) activates the mitogen activated protein (MAP) kinases, extracellular signal-regulated kinase (ERK) 1 and 2, in diverse cell types. In this study, we demonstrate that uPA stimulates migration of MCF-7 breast cancer cells, HT 1080 fibrosarcoma cells, and uPAR-overexpressing MCF-7 cells by a mechanism that depends on uPA receptor (uPAR)-ligation and ERK activation. Ras and MAP kinase kinase (MEK) were necessary and sufficient for uPA-induced ERK activation and stimulation of cellular migration, as demonstrated in experiments with dominant-negative and constitutively active mutants of these signaling proteins. Myosin light chain kinase (MLCK) was also required for uPA-stimulated cellular migration, as determined in experiments with three separate MLCK inhibitors. When MCF-7 cells were treated with uPA, MLCK was phosphorylated by a MEK-dependent pathway and apparently activated, since serine-phosphorylation of myosin II regulatory light chain (RLC) was also increased. Despite the transient nature of ERK phosphorylation, MLCK remained phosphorylated for at least 6 h. The uPA-induced increase in MCF-7 cell migration was observed selectively on vitronectin-coated surfaces and was mediated by a beta1-integrin (probably alphaVbeta1) and alphaVbeta5. When MCF-7 cells were transfected to express alphaVbeta3 and treated with uPA, ERK was still phosphorylated; however, the cells did not demonstrate increased migration. Neutralizing the function of alphaVbeta3, with blocking antibody, restored the ability of uPA to promote cellular migration. Thus, we have demonstrated that uPA promotes cellular migration, in an integrin-selective manner, by initiating a uPAR-dependent signaling cascade in which Ras, MEK, ERK, and MLCK serve as essential downstream effectors.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Movimento Celular/efeitos dos fármacos , Integrinas/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno , Quinase de Cadeia Leve de Miosina/metabolismo , Ativadores de Plasminogênio/farmacologia , Ativador de Plasminogênio Tipo Uroquinase/farmacologia , Proteínas ras/metabolismo , Anticorpos/farmacologia , Adesão Celular/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Flavonoides/farmacologia , Humanos , MAP Quinase Quinase 1 , Mutação , Quinase de Cadeia Leve de Miosina/antagonistas & inibidores , Fosforilação/efeitos dos fármacos , Biossíntese de Proteínas , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptores de Superfície Celular/fisiologia , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/genética , Células Tumorais Cultivadas , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Vitronectina/metabolismo , Proteínas ras/genética
18.
Int Nurs Rev ; 55(1): 73-80, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18275539

RESUMO

BACKGROUND: Low levels of Papanicolaou (Pap) screening participation in Vietnamese-American women remain a significant public health problem. The transtheoretical model (TTM) suggests that individuals adopting Pap smear behaviour move through a series of stages of readiness to change. Determining a woman's level of readiness for regular Pap testing and identifying the screening behaviour that an individual already performs is important in the development of successful intervention programmes that address the specific needs of Vietnamese-American women in different stages. AIMS: To describe Pap smear screening behaviours of Vietnamese-American women, and to examine whether constructs (stages of change, self-efficacy and perceived benefits/barriers) from the TTM are applicable to Vietnamese-American women relative to Pap testing. METHODS: A descriptive, cross-sectional design with snowball sampling was used to recruit participants. A total of 80 Vietnamese-American women completed the self-administered questionnaire. RESULTS: Most respondents (62.5%) reported previous Pap testing and only 46.3% receiving regular Pap testing. Compared with those in the pre-contemplation stage of the TTM, participants in maintenance reported significantly less self-efficacy (F (3, 73) = 4.85, P = 0.00), a lower level of perceived barriers (F (3, 75) = 5.99, P = 0.00) and a higher level of perceived benefits (F (3, 76) = 3.91, P = 0.01) relative to Pap smear. CONCLUSIONS: The results support some of the assumptions of the TTM but raise questions about the predicted relationships between stages of change and self-efficacy. Continued research is needed to identify the most effective theory-based interventions for evidence-based nursing practice in this population.


Assuntos
Asiático/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Teste de Papanicolaou , Aceitação pelo Paciente de Cuidados de Saúde/etnologia , Neoplasias do Colo do Útero/diagnóstico , Esfregaço Vaginal , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Modelos Psicológicos , Teoria da Construção Pessoal , Autoimagem , Estados Unidos , Neoplasias do Colo do Útero/etnologia , Vietnã/etnologia
19.
Poult Sci ; 97(12): 4351-4358, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30165535

RESUMO

This study was conducted to evaluate the effects of the blend of organic acids (OAs) and medium-chain fatty acids (MCFAs) in broiler chickens. A total of 816 1-d-old male Ross 308 broiler chickens (35 ± 0.44 g) were randomly allocated into 1 of the following 6 dietary treatments (17 broilers per pen with 8 pens per treatment): dietary treatments consisted of corn-soybean meal-based basal diet and the basal diet supplemented with 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs. The study lasted 5 wk during which growth performance was determined. In the current study, the inclusion of 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs in the basal diet linearly increased (P < 0.05) body weight gain and improved feed conversion ratio (P < 0.0001) on day 7 to 14, day 14 to 35, as well as overall. Increasing inclusion of the blend of OAs and MCFAs levels in the diets also linearly increased (P = 0.001) the digestibility of dry matter on day 35. Broilers fed with different levels of the blend of OAs and MCFAs showed a linear increment (P = 0.042) in Lactobacillus concentration and decrease (P = 0.002) in Escherichia coli concentration. With regard to relative organ weight, a trend of linear reduction (P = 0.052) in bursa of Fabricius weight of broilers fed the blend of OAs and MCFAs was observed. There was a significant linear improvement (P = 0.011) in the IgG concentration associated with the inclusion of the blend of OAs and MCFAs levels in the diets. In conclusion, the blend of OAs and MCFAs supplementation positively influenced growth performance, nutrient digestibility, and excreta microflora in broiler chickens.


Assuntos
Ácidos/farmacologia , Galinhas/fisiologia , Digestão/efeitos dos fármacos , Ácidos Graxos/farmacologia , Fezes/microbiologia , Carne/análise , Nutrientes/fisiologia , Ácidos/administração & dosagem , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Análise Química do Sangue/veterinária , Galinhas/sangue , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Ácidos Graxos/administração & dosagem , Masculino , Compostos Orgânicos/administração & dosagem , Compostos Orgânicos/farmacologia , Distribuição Aleatória
20.
Meat Sci ; 145: 399-406, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30053746

RESUMO

The objective of the current study was to determine the effects of market type (super market - SM, indoor market - IM, open market - OM) and sampling time (at the opening - T0 and 4 h after the opening - T4) on antioxidant capacity, lipid oxidation, and descriptive sensory attributes of beef in Vietnam. Values of FC and TEAC were greater in OM beef than IM and SM (P < 0.001) and FC value was also greater at T4 than T0 (P = 0.038). The beef from SM had 7% greater TBARS than IM and OM (P = 0.003). Livery odor was less intense in raw beef from OM when compared to SM and IM (P ≤ 0.047). Sour odor in raw beef, and livery flavor in cooked beef was increased from T0 to T4 (P ≤ 0.035). Principal component analysis of descriptive sensory attributes indicated that FC and TEAC could predict partial livery flavor in cooked beef, but not off-odors in raw beef.


Assuntos
Comércio , Preferências Alimentares , Peroxidação de Lipídeos , Odorantes , Carne Vermelha/análise , Paladar , Animais , Antioxidantes , Bovinos , Culinária , Feminino , Abastecimento de Alimentos , Humanos , Masculino , Oxirredução , Análise de Componente Principal , Substâncias Reativas com Ácido Tiobarbitúrico , Fatores de Tempo , Vietnã
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA