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1.
Phys Rev Lett ; 133(7): 071501, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39213544

RESUMO

On 9 October 2022, the Large High Altitude Air Shower Observatory (LHAASO) reported the observation of the very early TeV afterglow of the brightest-of-all-time gamma-ray burst 221009A, recording the highest photon statistics in the TeV band ever obtained from a gamma-ray burst. We use this unique observation to place stringent constraints on the energy dependence of the speed of light in vacuum, a manifestation of Lorentz invariance violation (LIV) predicted by some quantum gravity (QG) theories. Our results show that the 95% confidence level lower limits on the QG energy scales are E_{QG,1}>10 times the Planck energy E_{Pl} for the linear LIV effect, and E_{QG,2}>6×10^{-8}E_{Pl} for the quadratic LIV effect. Our limits on the quadratic LIV case improve previous best bounds by factors of 5-7.

2.
Phys Rev Lett ; 132(13): 131002, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38613275

RESUMO

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15 PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

5.
Phys Rev Lett ; 127(3): 031102, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34328784

RESUMO

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

6.
Phys Rev Lett ; 126(14): 141101, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33891464

RESUMO

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of π^{0}'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk.

7.
Zhonghua Gan Zang Bing Za Zhi ; 27(9): 698-703, 2019 Sep 20.
Artigo em Chinês | MEDLINE | ID: mdl-31594095

RESUMO

Objective: To preliminary, explore the effect of small intestinal epithelial dendritic cells on the occurrence and development of nonalcoholic fatty liver disease in mice. Methods: Thirty-two (half male and half female) 4-week-old C57BL/6 mice were randomly divided into two groups. The mice were fed with normal diet (SD group) and high-fat diet (HFD group). Eight mice (half male and half female) were randomly killed from each group over the 14 and 20-weeks feeding period to observe their body weight, liver and small-intestine wet weight. Alanine aminotransferase, aspartate aminotransferase, blood glucose, high-density lipoprotein, low-density lipoprotein, total cholesterol and triglyceride were determined by eyeball blood samples. Pathological diagnosis and alcoholic fatty liver disease activity score were collected. The number of mice small intestinal dendritic cells was observed under a microscope. Statistical analysis was performed to compare two groups of independent samples with homogeneity test of variance, t test, and covariance analysis. Results: The body weight, liver wet weight, serum alanine aminotransferase and aspartate aminotransferase of mice in HFD group were significantly higher than those of control group at 20 weeks (P < 0.05), and the serum high density lipoprotein of mice in HFD group was significantly higher than that of SD group at 14 weeks (P < 0.05). At 14th weeks, the liver tissue of mice in HFD group had early pathological manifestations of hepatitis (fatty degeneration, punctate necrosis and balloon-like degeneration). Of which 87.5% (7/8) of them were diagnosed as non-alcoholic steatohepatitis or non-alcoholic fatty liver disease, while only a few mice in SD group had early pathological manifestations of hepatitis. At 20th weeks, all mice in HFD group were diagnosed with non-alcoholic steatohepatitis or non-alcoholic fatty liver disease, while none of the mice in SD group was diagnosed with non-alcoholic fatty liver disease. At both time points, the percentage of small intestinal dendritic cells in HFD group was significantly higher than that in SD group (14 weeks: 4.181 ± 4.314 vs. 15.099 ± 10.349; 20 weeks: 9.615 ± 8.267 vs. 32.839 ± 24.475, both P < 0.05). Statistical analysis combined with the alcoholic fatty liver disease activity score showed that there was no linear correlation between the two groups (regression coefficient was 20.196%). Conclusion: The number and different staging of small intestinal dendritic cells in mice is associated with the occurrence and development of NAFLD.


Assuntos
Células Dendríticas/citologia , Intestino Delgado/citologia , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Dieta Hiperlipídica , Feminino , Fígado , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Distribuição Aleatória
8.
Phys Rev Lett ; 123(5): 051101, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31491288

RESUMO

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100 TeV. As a result, we observed 24 photonlike events with E>100 TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100 TeV from an astrophysical source.

9.
Zhonghua Yi Xue Za Zhi ; 97(13): 1011-1014, 2017 Apr 04.
Artigo em Chinês | MEDLINE | ID: mdl-28395420

RESUMO

Objective: To assess the clinical results of the method of anatomic coracoclavicular ligament reconstruction for distal clavicle fractures. Methods: From August 2013 to January 2015, the super image system was used to measure the CT data of 16 patients suffering distal clavicle fractures before operation in Department of Orthopaedics , the First Affiliated Hospital of Nanjing Medical Univerisity. The fractures' morphological features and acromioclavicular dislocation degree were assessed. By referring to the data collected by the my research group on Chinese people's coracoclavicular ligament, the injuries of the coracoclavicular ligament were estimated, which was then to verify the actual injuries detected during operation. Coracoclavicular ligament reconstruction was performed on patients and screws or suture anchors fixing small bone blocks was used as an adjuvant therapy. Clinical and radiological follow-up was at 1, 3, 6 and 12 months after the procedure. The clinical outcomes were assessed pre- and postoperatively with Constant Scores. Anteroposterior radiographs for the bilateral acromioclavicular joints were obtained immediately after surgery and every follow-up.To compare the reduction maintenance, coracoclavicular distances of the injured shoulders were measured in preoperative and postoperative standard radiographs. Results: All patients received satisfactory fracture and acromioclavicular joint reduction. The average follow-up period was (12.6±3.9) months (ranging from 6 to 22 months). Fractures healed six months after the operation. The coracoclavicular distances increased from (7.8±1.4)mm at one month follow-up to (7.9±1.2)mm at the final follow-up (P>0.05), which could be considered as no difference statistically. The constant score significantly increased from (49.1±4.4) at one month follow-up to (93.8±2.1) at the final evaluation (P<0.001). Obvious loss of acromioclavicular joint reduction was not observed after the operation. Coracoid process and calvicle fractures did not appear. Fractures healed well and shoulder joints also functioned well. Patients' lives and work went back to normal. Conclusion: Accompanied by ligament injuries, distal clavicle fractures is different from middle fractures. Coracoclavicular ligament injury is a major cause of the acromioclavicular joint instability, and the focus of the surgery. Therefore, the application of the double-bundle coracoclavicular ligament reconstruction is a feasible method to treat distal clavicle fractures, displaying satisfying clinical results.


Assuntos
Clavícula/lesões , Fraturas Ósseas/cirurgia , Ligamentos Articulares/cirurgia , Articulação Acromioclavicular , Humanos , Luxações Articulares , Âncoras de Sutura , Resultado do Tratamento
10.
Zhonghua Fu Chan Ke Za Zhi ; 51(8): 576-80, 2016 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-27561935

RESUMO

OBJECTIVE: To investigate the factors affecting the vaginal birth after cesarean (VBAC). METHODS: Totaly 298 women who underwent trial of labor after cesarean section (TOLAC) from Jan 2015 to Dec 2015 were recruited from Beijing Obstetrics and Gynecology Hospital, FuXing Hospital, Tongzhou Maternal and Child Health Hospital of Beijing, the Second Affiliated Hospital of Chongqing Medical University and the People's Hospital of Chengyang District of Qingdao. The maternal age, the interval from the last cesarean section, the body mass index (BMI) before pregnancy, the weight gain during pregnancy, the way into labor, the Bishop score before labor, the gestational age and the birth weight of the neonate were recorded in a self-made form. The factors affecting VBAC were analyzed by univariate analysis and multivariable logistic regression. RESULTS: (1)The incidence of VBAC, uterine rupture, postpartum hemorrhage and neonatal asphyxia were 70.5% (210/298), 2.7% (8/298), 9.4% (28/298) and 1.3% (4/298), respectively. No maternal death and perinatal death occurred. (2)The univariate analysis suggested that the maternal age, the BMI before pregnancy, the Bishop score before labor, the labor induction, the gestational age at delivery and the neonatal weight were factors affecting VBAC. The maternal age and the Bishop score before labor were significantly higher in the VBAC group than in the unsuccessful TOLAC group(P<0.05). While the BMI before pregnancy, the induction rate, the gestational weeks at delivery and the birth weight of the neonate were significantly lower in the VBAC group than in the unsuccessful TOLAC group (P<0.05). Multivariable logistic regression analysis showed that successful VBAC was affected by the maternal age, the BMI before pregnancy, the Bishop score before labor and the birth weight of the neonates(P<0.05). CONCLUSION: The maternal age, the BMI before pregnancy, the Bishop score before labor and the birth weight of neonate are the main factors affecting VBAC.


Assuntos
Índice de Massa Corporal , Cesárea/estatística & dados numéricos , Idade Materna , Prova de Trabalho de Parto , Nascimento Vaginal Após Cesárea/estatística & dados numéricos , Peso ao Nascer , China/epidemiologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Trabalho de Parto Induzido , Modelos Logísticos , Obesidade/complicações , Hemorragia Pós-Parto , Gravidez , Resultado da Gravidez , Estudos Retrospectivos , Ruptura Uterina , Nascimento Vaginal Após Cesárea/efeitos adversos , Aumento de Peso , Adulto Jovem
11.
Sci Rep ; 6: 25809, 2016 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-27174224

RESUMO

A rechargeable hybrid aqueous battery (ReHAB) containing NASICON-type M3V2(PO4)3 (M = Li, Na) as the cathodes and Zinc metal as the anode, working in Li2SO4-ZnSO4 aqueous electrolyte, has been studied. Both of Li3V2(PO4)3 and Na3V2(PO4)3 cathodes can be reversibly charge/discharge with the initial discharge capacity of 128 mAh g(-1) and 96 mAh g(-1) at 0.2C, respectively, with high up to 84% of capacity retention ratio after 200 cycles. The electrochemical assisted ex-XRD confirm that Li3V2(PO4)3 and Na3V2(PO4)3 are relative stable in aqueous electrolyte, and Na3V2(PO4)3 showed more complicated electrochemical mechanism due to the co-insertion of Li(+) and Na(+). The effect of pH of aqueous electrolyte and the dendrite of Zn on the cycling performance of as designed MVP/Zn ReHABs were investigated, and weak acidic aqueous electrolyte with pH around 4.0-4.5 was optimized. The float current test confirmed that the designed batteries are stable in aqueous electrolytes. The MVP//Zn ReHABs could be a potential candidate for future rechargeable aqueous battery due to their high safety, fast dynamic speed and adaptable electrochemical window. Moreover, this hybrid battery broadens the scope of battery material research from single-ion-involving to double-ions -involving rechargeable batteries.

12.
Oncogene ; 33(31): 4069-76, 2014 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-24013226

RESUMO

Metastasis is responsible for the rapid recurrence and poor survival of malignancies. Epithelial-mesenchymal transition (EMT) has a critical role in metastasis. Increasing evidence indicates that EMT can be regulated by microRNAs (miRNAs). miR-148a is a liver-abundant miRNA. However, the role of miR-148a in the development of liver cancer remains largely unknown. In this study, we found that, compared with normal livers, miR-148a was significantly decreased in hepatocellular carcinoma (HCC) tissues, especially in those with the portal vein tumor thrombus. An in vitro transwell assay and an in vivo orthotopic liver xenograft model showed that the restoration of miR-148a expression significantly repressed the migration and pulmonary metastasis of hepatoma cells. Linear regression analysis revealed a positive correlation between the expression of miR-148a and the mRNA level of E-cadherin gene in human HCC tissues. Both gain- and loss-of-function studies disclosed that miR-148a promoted the expression of epithelial marker (E-cadherin) and reduced the levels of mesenchymal markers (N-cadherin, fibronectin or vimentin) in hepatoma cells. These data suggest that miR-148a may suppress EMT and cancer metastasis. Further mechanistic investigations showed that miR-148a directly inhibited Met expression by binding to its 3'-UTR. Moreover, the reintroduction of miR-148a attenuated the downstream signaling of Met, like activated phosphorylation of AKT-Ser473 and inhibitory phosphorylation of GSK-3ß-Ser9, and consequently reduced the nuclear accumulation of Snail, a transcription factor that promotes EMT. Taken together, miR-148a may negatively regulate Met/Snail signaling and therefore inhibit the EMT and metastasis of hepatoma cells. These findings highlight the significance of miR-148a downregulation in tumor progression and implicate miR-148a as an attractive candidate for cancer therapy.


Assuntos
Carcinoma Hepatocelular/metabolismo , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , Metástase Neoplásica/patologia , Transdução de Sinais , Animais , Caderinas/metabolismo , Carcinoma Hepatocelular/patologia , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas Experimentais , Metástase Neoplásica/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Fatores de Transcrição da Família Snail , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas
13.
Amino Acids ; 26(3): 267-71, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15221507

RESUMO

Taurine has beneficial effects on lipid metabolism in experimental animals fed with high-cholesterol or high fat diets. Whether taurine benefits lipid metabolism in humans has rarely been investigated. The aim of this study was to evaluate the effects of taurine on serum lipids in overweight or obese young adults. Thirty college students (age: 20.3+/-1.7 years) with a body mass index (BMI) >/=25.0 kg/m(2), and with no evidence of diabetes mellitus were selected and assigned to either the taurine group (n=15) or the placebo group (n=15) by double-blind randomization. Taurine 3 g/day or placebo was taken orally for 7 weeks. Triacylglycerol (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and plasma glucose were measured before and after supplementation. The atherogenic index (AI) was calculated as (TC-HDL-C)/HDL-C. There were no differences in any baseline parameter between the two groups. Taurine supplementation decreased TG and AI significantly. Body weight also reduced significantly in the taurine group. These results suggest that taurine produces a beneficial effect on lipid metabolism and may have an important role in cardiovascular disease prevention in overweight or obese subjects.


Assuntos
Peso Corporal , Lipídeos/sangue , Obesidade/sangue , Taurina/farmacologia , Adulto , Índice de Massa Corporal , Colesterol/sangue , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Lipoproteínas/sangue , Masculino , Taurina/administração & dosagem , Taurina/metabolismo , Triglicerídeos/sangue
14.
Am J Trop Med Hyg ; 55(1): 12-6, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8702015

RESUMO

Immunoglobulin M (IgM) antibody to dengue virus was examined from a total of 3,099 serum samples collected in southern Taiwan. Of 1,232 sera collected from a junior high school and four elementary schools in Liu-Chiu, 35 were IgM-positive, demonstrating that the dengue virus has been circulating on the island, despite the fact that no epidemic has been reported in the past 10 years. Sixteen of 925 sera collected from three elementary schools in Tung-Kang in 1991 were found to be IgM-positive and two of 192 sera from adults in the local community were positive. The IgM-positive subjects tended to be aggregated around a port. Fishing boats that had stopped in neighboring endemic countries were presumed to have introduced the virus periodically, causing a low level of inapparent infections. In the Kaohsiung area, two of 108 suspected clinical cases and four of 642 community-based sera were IgM-positive. Rapid urbanization has provided appropriate circumstances for vector breeding in this area and the high population density has also increased contact frequency between humans and mosquito vectors. This has, in turn, increased the possibility of silent transmission of the dengue virus via either intermittent reintroduction of the virus or continuation of inapparent infections or both. Establishment of a early warning system using the IgM antibody capture-enzyme-linked immunosorbent assay is suggested for effective monitoring of the disease.


Assuntos
Dengue/transmissão , Adolescente , Adulto , Anticorpos Antivirais/sangue , Criança , Dengue/sangue , Dengue/epidemiologia , Dengue/imunologia , Vírus da Dengue/imunologia , Humanos , Imunoglobulina M/sangue , Prevalência , Taiwan/epidemiologia
15.
HPB Surg ; 9(1): 43-6, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8857453

RESUMO

To determine whether definitive surgery such as cholecysectomy or extraction of bile duct stones is appropriate in cirrhotic patients the results of definitive surgery have been reviewed retrospectively in a group of 112 cirrhotic patients with cholelithiasis. Eighty-seven of these patients underwent definitive surgery for gallstones and the remaining 25 were treated conservatively. Child's criteria were applied to each patient. Patients with Child's grade A disease had fewer emergency procedures, operative blood loss and transfusion were less and they had a shorter hospital stay compared with patients with grades B and C. There were 4 deaths after definitive surgery for emergency conditions and these were all in Child's grade C. Of the 83 survivors after definitive procedures 78 patients (93.9%) were still alive 52.8 months later without any biliary tract symptoms. Of the 25 patients undergoing conservative treatment 2 were Child's B and 23 were Child's C grade. We suggest that definitive surgery can be carried out safely, in Child's A and B cirrhotic patients, either electively or as an emergency. However, a more conservative approach is advisable in Child C patients with acute conditions and definitive surgery is recommended as an elective procedure after the liver function has improved.


Assuntos
Colelitíase/cirurgia , Cirrose Hepática/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Colelitíase/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/cirurgia , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
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