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1.
Phys Rev Lett ; 129(26): 261103, 2022 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-36608208

RESUMEN

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9} GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

2.
Zhonghua Yi Xue Za Zhi ; 98(44): 3607-3612, 2018 Nov 27.
Artículo en Zh | MEDLINE | ID: mdl-30486579

RESUMEN

Objective: To evaluate the performance of MALDI Biotyper system in identification of clinically isolated pathogens so as to provide a new rapid identification method. Methods: Total 21 270 pathogens strains, isolated from the First Affiliated Hospital of Fujian Medical Universityduring Nov. 2015 to Dec. 2016, were identified by VITEK-Ⅱ, API and MALDI Biotyper system, respectively.The isolated strains were confirmed by DNA sequencing. Results: The identification of common bacteria with MALDI Biotyper and phenotypic system is highly consistent (>95% and >90%). Among 43 strains of anaerobic bacteria, MALDI Biotyper could identify 90.7% bacteria to species level and 97.7% bacteria to genus level with the statistical significance(χ(2)=6.76, P<0.01), while phenotypic system only identified 65.1% bacteria to species and 69.8% bacteria to genus. Also, no statistical significance was shown for Trichosporon and Candida(P>0.05). MALDI Biotyper could identify 76% filamentous fungi and all of Actinomycetes, Nocardia, Mycobacterium and Legionella to genus level. Conclusions: MALDI Biotyper is an easy-performed, sensitive method for the identification of clinically isolated pathogens. Additionally, the pretreatment and reference database has the effect on identification.


Asunto(s)
Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Hongos , Legionella , Mycobacterium , Análisis de Secuencia de ADN
3.
Cytopathology ; 27(1): 59-69, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25496004

RESUMEN

BACKGROUND: Fine needle aspiration cytology (FNAC) of axillary lymphadenopathy is a helpful tool in the pre-operative diagnosis of breast cancer patients with axillary lymphadenopathy. To date, no published meta-analysis or systematic review has been performed to assess its overall value. We therefore conducted a meta-analysis to establish the overall diagnostic value of FNAC for axillary lymph node metastasis. METHODS: After a review and quality assessment of 31 studies, published either in Chinese or English, the sensitivity, specificity and other measurements of accuracy of FNAC of axillary lymphadenopathy were pooled using random-effects models. A summary of the receiver-operating characteristic curves was used to summarize overall accuracy. RESULTS: We provided the following estimated values for FNAC in the diagnosis of axillary lymph node metastasis: sensitivity, 0.63 [95% confidence interval (CI), 0.61-0.65]; specificity, 0.99 (95% CI, 0.99-0.99); positive likelihood ratio, 26.52 (95% CI, 18.42-38.18); negative likelihood ratio, 0.34 (95% CI, 0.29-0.40); diagnostic odds ratio, 76.73 (95% CI, 51.98-113.28). CONCLUSIONS: FNAC has adequate sensitivity and high specificity in the diagnosis of axillary lymph node metastasis. A positive axillary FNA result could potentially alter disease management.


Asunto(s)
Biopsia con Aguja Fina , Neoplasias de la Mama/patología , Ganglios Linfáticos/patología , Adulto , Anciano , Anciano de 80 o más Años , Axila , Femenino , Humanos , Metástasis Linfática , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Sensibilidad y Especificidad
4.
Zhonghua Er Ke Za Zhi ; 61(8): 695-699, 2023 Aug 02.
Artículo en Zh | MEDLINE | ID: mdl-37528009

RESUMEN

Objective: To investigate the relationship between amino acid variations of respiratory syncytial virus (RSV) nonstructural protein (NS) 1 and the clinical characteristics. Method: A retrospective case review was conducted. From December 2018 to January 2020, a total of 81 cases of hospitalized children who were tested only positive for RSV by RT-PCR or PCR at the Department of Respiratory Medicine, Children's Hospital of Chongqing Medical University were included in the study. The NS1 genes of RSV subtype A and subtype B were amplified by PCR and sequenced. The amino acid sequences were analyzed. The Chi-square test and Mann-Whitney rank sum test were used to compare the clinical characteristics and type Ⅰ interferon levels of children with or without NS1 variation in the variation and non-variation groups. Results: Among 81 cases, there were 58 males and 23 females. There were 11 cases in the variation group, the age of onset was 2.0 (1.0, 11.0) months, included 4 cases of subtype A (variant sites were: 2 cases for Lys33Gln, one case for Gly2Asp, Pro67Ser, Leu137Phe, respectively) and 7 cases of subtype B (variant sites were: two cases for Val121Ile, one case for Tyr30Cys, Val65Met, Asn85Ser, Ser118Asn, Asp124Asn, respectively). These variant sites all appeared at a very low frequency 0.08 (0.04, 0.29) % in the NCBI PROTEIN database. There were 70 cases in non-variation group, the onset age was 3.5 (1.0, 7.0) months. The proportion of dyspnea in the variation group was higher than that in the non-variation group (10/11 vs. 47% (33/70), χ2=7.31, P<0.01). Conclusions: There are some variant sites in nonstructural protein NS1 of RSV. Children may be prone to have dyspnea with NS1 variations.


Asunto(s)
Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Niño , Masculino , Femenino , Humanos , Lactante , Aminoácidos , Estudios Retrospectivos , Virus Sincitial Respiratorio Humano/genética , Reacción en Cadena de la Polimerasa
5.
Science ; 380(6652): 1390-1396, 2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37289911

RESUMEN

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory (LHAASO) of the bright GRB 221009A, which serendipitously occurred within the instrument's field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger and then rose to a peak ~10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle of ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

6.
Math Biosci ; 128(1-2): 157-84, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7606133

RESUMEN

Periodic solutions have been found for some infectious disease models of the SI and SEI types. Here four SEI models with either disease-reduced or uniform reproduction are examined to determine the model features that do and do not lead to periodic solutions. The two SEI models with the simple mass action incidence beta XY can have periodic solutions for some parameter values, but the two SEI models with the standard mass action incidence lambda XY/N do not have periodic solutions. For some intermediate values of lambda in the SEI model with incidence lambda XY/N and uniform reproduction, the interior equilibrium is a saddle whose stable manifold separates the attractive regions for the disease-free equilibrium and the susceptible-free equilibrium.


Asunto(s)
Enfermedades Transmisibles/epidemiología , Métodos Epidemiológicos , Modelos Teóricos , Periodicidad , Demografía , Humanos , Incidencia
7.
J Math Biol ; 30(7): 717-31, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1522393

RESUMEN

The models considered for the spread of an infectious disease in a population are of SIRS or SIS type with a standard incidence expression. The varying population size is described by a modification of the logistic differential equation which includes a term for disease-related deaths. The models have density-dependent restricted growth due to a decreasing birth rate and an increasing death rate as the population size increases towards its carrying capacity. Thresholds, equilibria and stability are determined for the systems of ordinary differential equations for each model. The persistence of the infectious disease and disease-related deaths can lead to a new equilibrium population size below the carrying capacity and can even cause the population to become extinct.


Asunto(s)
Enfermedades Transmisibles/epidemiología , Modelos Biológicos , Densidad de Población , Animales , Humanos , Matemática
8.
Clin Exp Immunol ; 70(1): 217-21, 1987 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3500814

RESUMEN

The regional lymph nodes of mice show increased IL-2 activated killer (LAK) activity following immunization with the contact sensitizing agents, 'oxazolone' and picryl chloride. This is best elicited with 500 mu/ml human recombinant IL-2 and can be demonstrated with both YAC-1 and K562 targets. There is also a lesser increase in NK activity.


Asunto(s)
Citotoxicidad Inmunológica , Inmunización , Interleucina-2/farmacología , Células Asesinas Naturales/inmunología , Ganglios Linfáticos/inmunología , Animales , Relación Dosis-Respuesta Inmunológica , Ratones , Ratones Endogámicos CBA , Oxazolona/inmunología , Cloruro de Picrilo/inmunología , Factores de Tiempo
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