Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 152
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Nature ; 583(7815): 282-285, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32218527

RESUMEN

The ongoing outbreak of viral pneumonia in China and across the world is associated with a new coronavirus, SARS-CoV-21. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection2. Although bats are probable reservoir hosts for SARS-CoV-2, the identity of any intermediate host that may have facilitated transfer to humans is unknown. Here we report the identification of SARS-CoV-2-related coronaviruses in Malayan pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin-associated coronaviruses that belong to two sub-lineages of SARS-CoV-2-related coronaviruses, including one that exhibits strong similarity in the receptor-binding domain to SARS-CoV-2. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 suggests that pangolins should be considered as possible hosts in the emergence of new coronaviruses and should be removed from wet markets to prevent zoonotic transmission.


Asunto(s)
Betacoronavirus/genética , Betacoronavirus/aislamiento & purificación , Euterios/virología , Evolución Molecular , Genoma Viral/genética , Homología de Secuencia de Ácido Nucleico , Secuencia de Aminoácidos , Animales , Betacoronavirus/química , Betacoronavirus/clasificación , COVID-19 , China/epidemiología , Quirópteros/virología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/virología , Reservorios de Enfermedades/virología , Genómica , Humanos , Malasia , Pandemias , Filogenia , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Neumonía Viral/virología , Recombinación Genética , SARS-CoV-2 , Alineación de Secuencia , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Zoonosis/virología
2.
Mol Cell ; 70(2): 340-357.e8, 2018 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-29628309

RESUMEN

Whereas the actions of enhancers in gene transcriptional regulation are well established, roles of JmjC-domain-containing proteins in mediating enhancer activation remain poorly understood. Here, we report that recruitment of the JmjC-domain-containing protein 6 (JMJD6) to estrogen receptor alpha (ERα)-bound active enhancers is required for RNA polymerase II recruitment and enhancer RNA production on enhancers, resulting in transcriptional pause release of cognate estrogen target genes. JMJD6 is found to interact with MED12 in the mediator complex to regulate its recruitment. Unexpectedly, JMJD6 is necessary for MED12 to interact with CARM1, which methylates MED12 at multiple arginine sites and regulates its chromatin binding. Consistent with its role in transcriptional activation, JMJD6 is required for estrogen/ERα-induced breast cancer cell growth and tumorigenesis. Our data have uncovered a critical regulator of estrogen/ERα-induced enhancer coding gene activation and breast cancer cell potency, providing a potential therapeutic target of ER-positive breast cancers.


Asunto(s)
Neoplasias de la Mama/enzimología , Proliferación Celular , Receptor alfa de Estrógeno/metabolismo , Histona Demetilasas con Dominio de Jumonji/metabolismo , Complejo Mediador/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Activación Transcripcional , Animales , Sitios de Unión , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Estradiol/farmacología , Receptor alfa de Estrógeno/agonistas , Receptor alfa de Estrógeno/genética , Femenino , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Células MCF-7 , Complejo Mediador/genética , Ratones Endogámicos BALB C , Ratones Desnudos , Unión Proteica , Transporte de Proteínas , Proteína-Arginina N-Metiltransferasas/genética , Transducción de Señal , Activación Transcripcional/efectos de los fármacos
3.
Proc Natl Acad Sci U S A ; 120(13): e2218819120, 2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-36943875

RESUMEN

Certain ciliary transmembrane and membrane-tethered signaling proteins migrate from the ciliary tip to base via retrograde intraflagellar transport (IFT), essential for maintaining their ciliary dynamics to enable cells to sense and transduce extracellular stimuli inside the cell. During this process, the BBSome functions as an adaptor between retrograde IFT trains and these signaling protein cargoes. The Arf-like 13 (ARL13) small GTPase resembles ARL6/BBS3 in facilitating these signaling cargoes to couple with the BBSome at the ciliary tip prior to loading onto retrograde IFT trains for transporting towards the ciliary base, while the molecular basis for how this intricate coupling event happens remains elusive. Here, we report that Chlamydomonas ARL13 only in a GTP-bound form (ARL13GTP) anchors to the membrane for diffusing into cilia. Upon entering cilia, ARL13 undergoes GTPase cycle for shuttling between the ciliary membrane (ARL13GTP) and matrix (ARL13GDP). To achieve this goal, the ciliary membrane-anchored BBS3GTP binds the ciliary matrix-residing ARL13GDP to activate the latter as an ARL13 guanine nucleotide exchange factor. At the ciliary tip, ARL13GTP recruits the ciliary matrix-residing and post-remodeled BBSome as an ARL13 effector to anchor to the ciliary membrane. This makes the BBSome spatiotemporally become available for the ciliary membrane-tethered phospholipase D (PLD) to couple with. Afterward, ARL13GTP hydrolyzes GTP for releasing the PLD-laden BBSome to load onto retrograde IFT trains. According to this model, hedgehog signaling defects associated with ARL13b and BBS3 mutations in humans could be satisfactorily explained, providing us a mechanistic understanding behind BBSome-cargo coupling required for proper ciliary signaling.


Asunto(s)
Síndrome de Bardet-Biedl , Cilios , Humanos , Cilios/metabolismo , Transporte de Proteínas/genética , Síndrome de Bardet-Biedl/genética , Proteínas Hedgehog/metabolismo , Proteínas de la Membrana/metabolismo , Guanosina Trifosfato/metabolismo , Flagelos/metabolismo
4.
Cell Mol Life Sci ; 81(1): 121, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38457049

RESUMEN

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent gastrointestinal malignancies with high mortality worldwide. Emerging evidence indicates that long noncoding RNAs (lncRNAs) are involved in human cancers, including ESCC. However, the detailed mechanisms of lncRNAs in the regulation of ESCC progression remain incompletely understood. LUESCC was upregulated in ESCC tissues compared with adjacent normal tissues, which was associated with gender, deep invasion, lymph node metastasis, and poor prognosis of ESCC patients. LUESCC was mainly localized in the cytoplasm of ESCC cells. Knockdown of LUESCC inhibited cell proliferation, colony formation, migration, and invasion in vitro and suppressed tumor growth in vivo. Mechanistic investigation indicated that LUESCC functions as a ceRNA by sponging miR-6785-5p to enhance NRSN2 expression, which is critical for the malignant behaviors of ESCC. Furthermore, ASO targeting LUESCC substantially suppressed ESCC both in vitro and in vivo. Collectively, these data demonstrate that LUESCC may exerts its oncogenic role by sponging miR-6785-5p to promote NRSN2 expression in ESCC, providing a potential diagnostic marker and therapeutic target for ESCC patients.


Asunto(s)
Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , MicroARNs , ARN Largo no Codificante , Humanos , Línea Celular Tumoral , Progresión de la Enfermedad , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , MicroARNs/metabolismo , Invasividad Neoplásica/genética , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo
5.
Pediatr Res ; 95(1): 227-232, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37580551

RESUMEN

BACKGROUND: children who undergo CPB operations are at an elevated risk of infection due to immunosuppression. This study aims to investigate the association between lymphopenia following CPB and early postoperative infection in children. METHODS: A retrospective analysis including 41 children under 2 years old underwent CPB. Among them, 9 subjects had an early postoperative infection, and 32 subjects were period-matched without infection. Inflammatory cytokines, serum CRP and PCT values were measured in plasma, additionally, circulating total leucocyte and lymphocyte subpopulations were counted. RESULTS: Infected subjects exhibited significantly higher levels of inflammatory cytokines, including IL-6, IL-8, IL-10, IL-1ß and TNF-α, than non-infected subjects after CPB. Additionally, lower absolute number of lymphocyte and their subpopulations CD3+ T cells, CD4+ T-helper cells and CD8+cytotoxic T-cells, were observed in infected subjects. The impairment of T-cells Immune was found to be associated with higher levels of inflammatory cytokines IL-10. The ROC demonstrated that the absolute number of CD3+ T-cells <1934/ul, CD4+ T helper cells <1203/ul and CD8+cytotoxic T-cells <327/ul were associated with early postoperative infection. CONCLUSION: Higher levels of inflammatory cytokines resulted in T-cells lymphopenia after CPB, which significantly increasing the risk of postoperative infection in infants and young children. IMPACT: Infection complications after cardiopulmonary bypass (CPB) in pediatric CHD patients are serious issues, identifing the infection from after CPB remains a challenging. CPB can release numerous inflammatory cytokines associated with T cells lymphopenia, which increases the risk of postoperative infection after surgery. Monitoring T cells lymphopenia maybe more beneficial to predict early postoperative infection than C-reactive protein and procalcitonin.


Asunto(s)
Puente Cardiopulmonar , Linfopenia , Lactante , Humanos , Niño , Preescolar , Puente Cardiopulmonar/efectos adversos , Interleucina-10 , Estudios Retrospectivos , Citocinas , Linfocitos T , Linfopenia/etiología
6.
Chem Biodivers ; : e202401033, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38945823

RESUMEN

Four new clerodane diterpenoids, namely tinocapills A-D (1-4), and one known analogue (5) were isolated from the roots of Tinospora capillipes in the present study. The structures of these new compounds, including their absolute configurations, were determined through a combination of detailed spectroscopic analysis and theoretical statistical approaches, including electronic circular dichroism (ECD) analyses and quantum mechanical (QM)-NMR methods. Additionally, the stereostructure of 5 was confirmed via X-ray diffraction analysis. Furthermore, all these isolates were evaluated for their antibacterial and anti-inflammatory activities. Compounds 1, 2 and 5 demonstrated antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) with MICs ranging from 4 to 64 µg/mL, and compounds 3 and 4 exhibited potential anti-inflammatory effects by suppressing LPS-induced TNF-α and NO releases in RAW264.7 cells.

7.
Phys Rev Lett ; 128(18): 180501, 2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35594095

RESUMEN

Photonic polarization qubits are widely used in quantum computation and quantum communication due to the robustness in transmission and the easy qubit manipulation. An integrated quantum memory for polarization qubits is a useful building block for large-scale integrated quantum networks. However, on-demand storing polarization qubits in an integrated quantum memory is a long-standing challenge due to the anisotropic absorption of solids and the polarization-dependent features of microstructures. Here we demonstrate a reliable on-demand quantum memory for polarization qubits, using a depressed-cladding waveguide fabricated in a ^{151}Eu^{3+}:Y_{2}SiO_{5} crystal. The site-2 ^{151}Eu^{3+} ions in Y_{2}SiO_{5} crystal provides a near-uniform absorption for arbitrary polarization states and a new pump sequence is developed to prepare a wideband and enhanced absorption profile. A fidelity of 99.4±0.6% is obtained for the qubit storage process with an input of 0.32 photons per pulse, together with a storage bandwidth of 10 MHz. This reliable integrated quantum memory for polarization qubits reveals the potential for use in the construction of integrated quantum networks.

8.
J Org Chem ; 87(18): 12460-12469, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36067376

RESUMEN

A high efficiency protocol was developed for the synthesis of 2,5-disubstituted oxazoles via iodine-promoted oxidative domino cyclization. These reactions were performed with readily available methyl azaarenes and α-amino ketones under metal-free conditions. This protocol is a simple method with high functional group compatibility, a wide range of substrates, and excellent yield, providing a new way to synthesize azaarene-attached oxazoles.


Asunto(s)
Yodo , Cetonas , Catálisis , Yoduros , Estructura Molecular , Oxazoles , Estrés Oxidativo
9.
Clin Lab ; 68(5)2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35536068

RESUMEN

BACKGROUND: The combination of EBV associated myositis and hemophagocytic syndrome is very rare and is lacking sufficient clinical study. The authors describe a novel case of myositis and hemophagocytic syndrome in a 17-year-old boy with chronic EBV infection. METHODS: Hematological and immunological blood investigation, bone marrow aspirate, labial and muscle pathological test and immunohistochemistry staining of Epstein-Barr virus-encoded small RNA (EBER) were performed. RESULTS: The patient was started on prednisolone and methotrexate for treatment of the myositis and his symptoms decrease for 2 months and rapidly progressed with worsening cytopenia, liver function tests, and coagulation profile. The patient was treated empirically with intravenous antibiotics and human immunoglobulin G. He developed fulminant hemophagocytic syndrome and passed away due to multiorgan failure 14 months after the onset of the disease. CONCLUSIONS: Performing a limited IHC with EBER will be helpful to diagnose EBV infection involving muscle. EBV infection as a prognostic factor of myositis needs further studies.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Linfohistiocitosis Hemofagocítica , Miositis , Polimiositis , Adolescente , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/diagnóstico , Herpesvirus Humano 4/fisiología , Humanos , Linfohistiocitosis Hemofagocítica/diagnóstico , Masculino , Miositis/diagnóstico , Polimiositis/diagnóstico
10.
Neurochem Res ; 45(9): 2091-2099, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32591985

RESUMEN

Ischemic stroke (IS) is a common disease that seriously endangers human health. Patients with IS present with increased death of brain microvascular endothelial cells (BMECs). MALAT1 is found to be upregulated in IS patients. However, the function of MALAT1 in IS pathogenesis still remains unclear. This study aimed to investigate the role of MALAT1 in IS in vitro model and the related molecular mechanisms. The expressions of MALAT1 and miR-126 were detected by qPCR. The in vitro IS model was established by treating BMECs with oxygen-glucose deprivation (OGD). Cell viability and cell apoptosis were assessed by MTT assay and flow cytometry, respectively. Luciferase assay was conducted to examine the interplay between MALAT1 and miR-126. Western blotting was used to determine the protein levels of apoptosis-associated proteins (e.g. caspase 3, Bax and Bcl-2) and PI3K/Akt pathway-related proteins (e.g. PI3K, Akt, p-PI3K, p-Akt). OGD induced upregulation of MALAT1 and downregulation of miR-126 in HBMECs. MALAT1 knockdown promoted the proliferation of HBMECs and reduced the proportion of apoptotic HBMECs by regulating the expression of apoptosis-related proteins. MALAT1 targeted and negatively regulated miR-126 expression. Overexpression of miR-126 activated the PI3K/Akt pathway, which in turn affected the proliferation and apoptosis of HBMECs. MALAT1 negatively regulated PI3K/Akt pathway. MALAT1 inhibited the proliferation and induced the apoptosis of OGD-induced HBMECs through suppressing PI3K/AKT pathway by sponging miR-126, providing a potential therapeutic target for IS.


Asunto(s)
Apoptosis/fisiología , Células Endoteliales/metabolismo , MicroARNs/metabolismo , ARN Largo no Codificante/metabolismo , Transducción de Señal/fisiología , Encéfalo/citología , Hipoxia de la Célula/fisiología , Línea Celular , Proliferación Celular/fisiología , Regulación hacia Abajo/fisiología , Glucosa/deficiencia , Humanos , Oxígeno/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Regulación hacia Arriba/fisiología
11.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 42(2): 242-246, 2020 Apr 28.
Artículo en Zh | MEDLINE | ID: mdl-32385032

RESUMEN

Artificial intelligence (AI) represents the latest wave of computer revolution and is considered revolutionary technology in many industries including healthcare. AI has been applied in medical imaging mainly due to the improvement of computational learning,big data mining,and innovations of neural network architecture. AI can improve the efficiency and accuracy of imaging diagnosis and reduce medical cost;also,it can be used to predict the disease risk. In this article we summarize and analyze the application of AI in musculoskeletal imaging.


Asunto(s)
Inteligencia Artificial , Sistema Musculoesquelético/diagnóstico por imagen , Humanos , Redes Neurales de la Computación
12.
Zhongguo Zhong Yao Za Zhi ; 45(13): 3104-3111, 2020 Jul.
Artículo en Zh | MEDLINE | ID: mdl-32726018

RESUMEN

To further study and fully exploit the medicinal plant Sophora alopecuroides, the molecular markers related with the phenotypic traits of alkaloid content in S. alopecuroides should be detected. In this study, SSR molecular markers were used to analyze the genetic diversity and genetic structure of 23 S. alopecuroides populations, in combination with the association analysis between molecular markers and the alkaloid contents. The results showed that P, H, I, G_(st) and N_m values were 40.10%, 0.335 3, 0.504 5, 0.433 7 and 0.625 9 respectively, in 23 S. alopecuroides populations. This indicated that there was less gene exchange and higher genetic differentiation among different S. alopecuroides populations. The results of SSR unweighted pair-group method with arithmetic means(UPGMA) cluster showed that the S. alopecuroides populations relationship from Xinjiang was far from the populations of other regions, but the populations of S. alopecuroides from Gansu, Inner Mongolia and Qinghai were closely relevant to those from Ningxia. The 23 populations were further divided into 2 genetic subpopulations by the population structure analysis. Through association analysis, a total of 26 loci in 13 SSR markers were found to be significantly associated(P<0.005)with the content of MA, OMA, SC and OSC, and the rate of explanation on the phenotype variance of related markers ranged from 36.45% to 77.93%. Among the locus, 1 each were related with MA and OSC content at interpretation rate reached as high as 50% with high threshold(P<0.000 1). These results could provide support for the discovery of important genes in the alkaloid biosynthetic and metabolic pathway of S. alopecuroides.


Asunto(s)
Alcaloides , Plantas Medicinales , Sophora/genética , China , Variación Genética , Repeticiones de Microsatélite , Fenotipo
13.
Protein Expr Purif ; 160: 19-27, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30904445

RESUMEN

Hispidalin is a novel antimicrobial peptide isolated from the seeds of Benincasa hispida and is reported to have broad antimicrobial activity against various bacterial and fungal pathogens. To produce significant amounts of Hispidalin, a recombinant Hispidalin with an N-terminal 6 × His tag and an enterokinase sequence, for the first time, was successfully expressed in Escherichia coli or Pichia pastoris cell factory. Results showed that the E. coli-derived recombinant Hispidalin did not show any antimicrobial activity against all the tested strains, whereas the P. pastoris-derived recombinant Hispidalin (rHispidalin) showed a broad antibacterial spectrum against five pathogenic bacteria of both Gram-negative and Gram-positive. rHispidalin also has bactericidal activity and completely killed all of the Staphylococcus aureus within 40 min. Additionally, rHispidalin showed a broad range of thermostability and pH stability, and a hemolytic activity of less than 2% even at a concentration of 300 µg/ml; it was resistant to trypsin and proteinase K, but was moderately sensitive to pepsin and papain. Moreover, rHispidalin effectively permeabilized the cytoplasmic membrane and disrupted the morphology of targeted bacterial cells. After an initial optimization was performed, the amount of rHispidalin accumulation could reach as high as 98.6 µg/ml. These results indicate that Hispidalin could be produced on a large scale by P. pastoris and has a great potential to be utilized as a new antibacterial agent for further development.


Asunto(s)
Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/farmacología , Pichia/genética , Antibacterianos/química , Antibacterianos/metabolismo , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/metabolismo , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Cucurbitaceae/química , Cucurbitaceae/genética , Cucurbitaceae/metabolismo , Estabilidad de Medicamentos , Expresión Génica , Concentración de Iones de Hidrógeno , Pruebas de Sensibilidad Microbiana , Pichia/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacología
14.
Analyst ; 144(6): 1916-1922, 2019 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-30681671

RESUMEN

Antibiotics have been noted as an important class of emerging contaminants in the environment. Metal-organic frameworks (MOFs), which have been intensely investigated as a novel kind of sensing material, have been tentatively applied to the detection of antibiotics in recent years. In this work, a nanoscale MOF (In-sbdc) with a strong (quantum yield = 13%) and stable emission in water was synthesized. With its effective spectral overlap with tetracyclines, adsorption preconcentration and the usage of a masking agent, In-sbdc gave sensitive responses to a series of tetracycline antibiotics (tetracycline, chlorotetracycline and oxytetracycline) with detection limits of 0.28-0.30 µM, but another eight tested kinds of antibiotics did not cause a remarkable change in its emission (<10% of the response caused by an equal amount of tetracyclines). This MOF-based sensing system was successfully applied to tetracyclines detection in a series of actual water and food samples.


Asunto(s)
Antibacterianos/análisis , Técnicas Biosensibles , Monitoreo del Ambiente/métodos , Análisis de los Alimentos/métodos , Estructuras Metalorgánicas/química , Tetraciclinas/análisis , Contaminantes Químicos del Agua/análisis , Fluorescencia , Límite de Detección
15.
Int J Med Sci ; 15(2): 129-141, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29333097

RESUMEN

Purpose: To establish small-sized superparamagnetic polymeric micelles for magnetic resonance and fluorescent dual-modal imaging, we investigated the feasibility of MR imaging (MRI) and macrophage-targeted in vitro. Methods: A new class of superparamagnetic iron oxide nanoparticles (SPIONs) and Nile red-co-loaded mPEG-Lys3-CA4-NR/SPION polymeric micelles was synthesized to label Raw264.7 cells. The physical characteristics of the polymeric micelles were assessed, the T2 relaxation rate was calculated, and the effect of labeling on the cell viability and cytotoxicity was also determined in vitro. In addition, further evaluation of the application potential of the micelles was conducted via in vitro MRI. Results: The diameter of the mPEG-Lys3-CA4-NR/SPION polymeric micelles was 33.8 ± 5.8 nm on average. Compared with the hydrophilic SPIO, mPEG-Lys3-CA4-NR/SPION micelles increased transversely (r2), leading to a notably high r2 from 1.908 µg/mL-1S-1 up to 5.032 µg/mL-1S-1, making the mPEG-Lys3-CA4-NR/SPION micelles a highly sensitive MRI T2 contrast agent, as further demonstrated by in vitro MRI. The results of Confocal Laser Scanning Microscopy (CLSM) and Prussian blue staining of Raw264.7 after incubation with micelle-containing medium indicated that the cellular uptake efficiency is high. Conclusion: We successfully synthesized dual-modal MR and fluorescence imaging mPEG-Lys3-CA4-NR/SPION polymeric micelles with an ultra-small size and high MRI sensitivity, which were effectively and quickly uptaken into Raw 264.7 cells. mPEG-Lys3-CA4-NR/SPION polymeric micelles might become a new MR lymphography contrast agent, with high effectiveness and high MRI sensitivity.


Asunto(s)
Medios de Contraste/química , Macrófagos/efectos de los fármacos , Imagen por Resonancia Magnética/métodos , Micelas , Polímeros/química , Animales , Supervivencia Celular/efectos de los fármacos , Medios de Contraste/farmacología , Compuestos Férricos/química , Colorantes Fluorescentes/química , Espectroscopía de Resonancia Magnética , Nanopartículas de Magnetita/química , Ratones , Oxazinas/química , Tamaño de la Partícula , Polímeros/síntesis química , Células RAW 264.7
16.
Chemistry ; 23(27): 6562-6569, 2017 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-28133823

RESUMEN

Metal-organic frameworks (MOFs) are emerging in recent years as a kind of versatile fluorescent sensing materials, but their application to enzyme assays has rarely been studied. Here, the first example of a MOF-based label-free enzyme assay system is reported. A luminescent MOF was synthesized and applied to the activity analysis of polyphenol oxidase (PPO). With its distinct responses to the phenolic substrate and o-quinone product, this MOF could transduce the extent of PPO-catalyzed oxidation to fluorescence signal and enable the real-time monitoring of this reaction. Wide substrate adaptability and high sensitivity (detection limit=0.00012 U mL-1 ) were exhibited by this method, which meets the requirement of common bioanalysis. Interestingly, by the comparison with molecular capturing reagents, the heterogeneous nature of this MOF-based assay effectively preventing the interaction with the enzyme was proven, thus ensuring the authenticity of results.


Asunto(s)
Catecol Oxidasa/metabolismo , Estructuras Metalorgánicas/química , Agaricales/enzimología , Biocatálisis , Pruebas de Enzimas , Ligandos , Límite de Detección , Oxidación-Reducción , Quinonas/química , Quinonas/metabolismo , Solanum tuberosum/enzimología , Espectrometría de Fluorescencia , Especificidad por Sustrato
17.
Chemistry ; 23(61): 15498-15504, 2017 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-28836296

RESUMEN

As novel fluorescent-sensing materials, metal-organic frameworks (MOFs) have shown great potential in environmental monitoring. However, most of the researches are limited to traditional pollutants, whereas the application of MOFs to the detection of the pollutants with more complicated structures, such as endocrine disrupting chemicals (EDCs), has rarely been explored. The difficulties faced in the sensing of EDCs include their electronic stability and the structural similarity among homologues, which could be overcome by the incorporation of enzymatic reaction. In this work, the first example of enzyme-assisted MOF-fluorescent-sensing was developed for the analysis of diethylstilbestrol (DES, a synthetic estrogen). In this system, DES is first oxidized by HRP/H2 O2 quantitatively to its quinone form, and then the quinone product is selectively captured by a stilbene based luminescent MOF to induce fluorescence response. By the tandem sensitization and filtration of enzymatic reaction and MOF adsorption, this method shows high sensitivity (DL=89 nm) and can distinguish DES from other similar-structured EDCs.

18.
Korean J Parasitol ; 55(5): 555-559, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29103271

RESUMEN

Chigger mites are parasites of rodents and other vertebrates, invertebrates, and other arthropods, and are the only vectors of scrub typhus, in addition to other zoonoses. Therefore, investigating their distribution, diversity, and seasonal abundance is important for public health. Rodent surveillance was conducted at 6 districts in Shandong Province, northern China (114-112°E, 34-38°N), from January to December 2011. Overall, 225/286 (78.7%) rodents captured were infested with chigger mites. A total of 451 chigger mites were identified as belonging to 5 most commonly collected species and 3 genera in 1 family. Leptotrombidium scutellare and Leptotrombidium intermedia were the most commonly collected chigger mites. L. scutellare (66.2%, 36.7%, and 49.0%) was the most frequently collected chigger mite from Apodemus agrarius, Rattus norvegicus, and Microtus fortis, respectively, whereas L. intermedia (61.5% and 63.2%) was the most frequently collected chigger mite from Cricetulus triton and Mus musculus, respectively. This study demonstrated a relatively high prevalence of chigger mites that varied seasonally in Shandong Province, China.


Asunto(s)
Roedores/parasitología , Trombiculidae , Animales , Arvicolinae , China , Cricetulus , Ratones , Murinae , Ratas , Estaciones del Año , Trombiculidae/clasificación
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 37(3): 984-9, 2017 Mar.
Artículo en Zh, Inglés | MEDLINE | ID: mdl-30160844

RESUMEN

For the determination of molybdenum in molybdenum concentrate,lead molybdate gravimetric method was considered as standard method. In order to ensure the lead ions to be washed thoroughly from the entrained precipitate, lead molybdate precipitate was washed, filtered repeatedly, then ashed and burned. This method cannot satisfy the rapid measurement demand of mineral processing and metallurgy scientific research due to its time consuming. In the present work, molybdenum was determined by atomic absorption spectrometry indirectly and a rapid analysis method for molybdenum in molybdenum concentrate was proposed. The sample was dissolved by nitric acid, potassium chlorate and sulfuric acid, pH was adjusted by acetic acid and ammonium acetate buffer solution to pH 5~7, then a certain amount and excess of lead standard was added. Based on lead molybdate was considered as undissolved electrolyte on room temperature, the solubility of lead molybdate was 1.16×10-5g, far less than 0.01 g, was considered as the undissolved electrolyte, the electrolyte insoluble at a certain temperature can complete precipitation, usually compared with the solubility production product Qc and the relative size of constant Ksp, when Qc>Ksp, solution was supersaturated, precipitation was precipitate completely, the content of molybdenum in molybdenum concentrate was 40%~60%, the amount of lead was 0.125 0~0.150 0 g, took the minimum calculated solution lead molybdate ion product, Qc=[Pb2+][MoO2-4]=2.51×10-5,Ksp=1.0×10-13,QcKsp,Therefore lead molybdate precipitate can be precipitated completely, after dry filtered, the excess of lead ions were determined by atomic absorption spectrometry, the content of molybdenum was calculated by subtraction method. In this paper, the amount of acetic acid-ammonium acetate buffer solution, the amount of lead standard, time of lead molybdate precipitation, heating time and maximum amount of coexisting ions such as W6+, Sn4+, Cu2+, etc were investigated. Compared with lead molybdate gravimetric method, repeatedly washing, ashing and burning with lead molybdate were eliminated by proposed method, which was simple, easy to master and was able to cut the analysis time in half. The control experiments were conducted by lead molybdate gravimetric method and proposed method. After the results were implemented by mathematical statistics, it can be concluded that it had good accuracy and precision for the proposed method, which can be applied to rapid analysis of molybdenum in molybdenum concentrate for mineral processing and metallurgy.

20.
Zhonghua Nan Ke Xue ; 23(6): 540-549, 2017 Jun.
Artículo en Zh | MEDLINE | ID: mdl-29722948

RESUMEN

OBJECTIVE: To compare the clinical effects of transperitoneal (Tp) versus extraperitoneal (Ep) robot-assisted radical prostatectomy (RARP) in the treatment of localized prostate cancer. METHODS: We searched PubMed, EMBASE, Web of Science, EBSCO, Cochrane Library, Wanfang, CNKI, and CBM for the articles comparing the clinical effect Tp-RARP with that of Ep-RARP in the treatment of localized prostate cancer published from January 2000 to November 2016. All the articles must meet the inclusion criteria, that is, dealing with at least one of the following aspects: operation time, intraoperative blood loss, postoperative catheterization time, length of bed confinement, perioperative complications, positive surgical margins, bowel-related complications, postoperative anastomotic leakage, and postoperative urinary continence. We subjected the data obtained to statistical analysis using the RevMan5.3 software. RESULTS: Two randomized controlled trials and six case-control studies were included in this meta-analysis, involving 451 cases of Tp-RARP and 676 cases of Ep-RARP. Compared with Tp-RARP, Ep-RARP showed significantly shorter operation time (WMD = 21.39, 95% CI: 7.54-35.24, P = 0.002), shorter length of bed confinement (WMD = 0.85, 95% CI: 0.61-1.09, P <0.001), and lower rate of bowel-related complications (RR = 9.74, 95% CI: 3.26-29.07, P <0.001). However, no statistically significant differences were found between the two strategies in intraoperative blood loss (WMD = -8.12, 95% CI: -27.86-11.63, P = 0.42), postoperative catheterization time (WMD = 0.17, 95% CI: -0.55-0.21, P = 0.38), or the rates of perioperative complications (RR = 1.34, 95% CI: -0.97-1.87, P = 0.08), positive surgical margins (RR = 1.24, 95% CI: 0.95-1.61, P = 0.12), anastomotic leakage (RR = 0.98, 95% CI: 0.46-2.10, P = 0.95), urinary continence at 3 months (RR = 0.96, 95% CI: 0.91-1.00, P = 0.05) and urinary continence at 6 months (RR = 1.00, 95% CI: 0.97-1.02, P = 0.82). CONCLUSIONS: Ep-RARP has the advantages of shorter operation time, shorter length of bed confinement and lower rate of bowel-related complications over Tp-RARP, and therefore may be a better option for the treatment of localized prostate cancer. However, more multi-centered randomized controlled clinical trials are needed for further evaluation of these two approaches.


Asunto(s)
Prostatectomía/métodos , Neoplasias de la Próstata/cirugía , Procedimientos Quirúrgicos Robotizados/métodos , Pérdida de Sangre Quirúrgica , Estudios de Casos y Controles , Humanos , Masculino , Márgenes de Escisión , Tempo Operativo , Complicaciones Posoperatorias , Prostatectomía/efectos adversos , Neoplasias de la Próstata/patología , Ensayos Clínicos Controlados Aleatorios como Asunto , Procedimientos Quirúrgicos Robotizados/efectos adversos , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA