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1.
Opt Lett ; 48(21): 5455-5458, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37910676

RESUMEN

In this manuscript, we propose a digital coherent detection method to surpass the limitation of a coherent length on the detection range of a coherent lidar. This method rapidly reconstructs the laser phase noise utilizing the multi-channel delay self-homodyne and the generalized inverse of the system observation matrix. Subsequently, the reconstructed phase noise is utilized to expunge its perturbation onto the target information in the digital domain, thereby effectively surmounting the coherence length limitation. Through experimentation, the proposed method is verified to produce stable and high-quality interference even when the optical path difference between two beams exceeds 1000 times the coherence length. Additionally, the equivalent laser linewidth is compressed by 105 times.

2.
Nat Med ; 26(6): 845-848, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32350462

RESUMEN

We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.


Asunto(s)
Anticuerpos Antivirales/sangre , Formación de Anticuerpos/efectos de los fármacos , Betacoronavirus/patogenicidad , Infecciones por Coronavirus/tratamiento farmacológico , Neumonía Viral/tratamiento farmacológico , Adulto , Anciano , Formación de Anticuerpos/inmunología , Antivirales/uso terapéutico , Betacoronavirus/genética , COVID-19 , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Persona de Mediana Edad , Pandemias/prevención & control , Neumonía Viral/sangre , Neumonía Viral/inmunología , Neumonía Viral/virología , SARS-CoV-2
3.
FASEB J ; 16(8): 902-4, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12039874

RESUMEN

The wood frog Rana sylvatica survives for weeks during winter hibernation with up to 65% body water frozen as ice. Natural freeze tolerance includes both seasonal and freeze-induced molecular adaptations that control ice formation, deal with long-term ischemia, regulate cell volume changes, and protect macromolecules. This report identifies and characterizes a novel freeze-inducible gene, li16, that codes for a protein of 115 amino acids. Northern blot analysis showed that li16 transcript levels rose quickly during freezing to reach levels 3.7-fold higher than control values after 24 h; immunoblotting showed a parallel 2.4-fold rise in Li16 protein. Regulatory influences on gene expression were assessed. Nuclear runoff assays confirmed that freezing initiated an increase in the rate of li16 transcription, and analysis of signal transduction pathways via in vitro incubation of liver slices implicated a cGMP-mediated pathway in li16 expression. Gene and protein expression in liver was also strongly stimulated by anoxia exposure, whereas the gene was less responsive to dehydration stress. The strong response of li16 to both freezing and anoxia, and the rapid down-regulation of the gene when oxygen was reintroduced, suggest that the Li16 protein may play a role in ischemia resistance during freezing.


Asunto(s)
Proteínas Anfibias/genética , Ranidae/genética , Proteínas Anfibias/metabolismo , Animales , Northern Blotting , Western Blotting , GMP Dibutiril Cíclico/farmacología , Relación Dosis-Respuesta a Droga , Congelación , Regulación de la Expresión Génica/efectos de los fármacos , Hipoxia/fisiopatología , Mucosa Intestinal/metabolismo , Hígado/metabolismo , Miocardio/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Temperatura , Factores de Tiempo , Transcripción Genética , Regulación hacia Arriba/efectos de los fármacos , Privación de Agua/fisiología
4.
Zhonghua Zhong Liu Za Zhi ; 26(3): 139-42, 2004 Mar.
Artículo en Zh | MEDLINE | ID: mdl-15196431

RESUMEN

OBJECTIVE: To study the mechanism of topotecan (TPT) resistance in ovarian cancer cell line. METHODS: A TPT-resistant ovarian cancer cell line A2780/TPT established in this laboratory was used in this study. Intracellular rhodamine fluorescence intensity of the TPT-resistant cells and parental cells were measured by flow cytometry. The gene expression of membrane protein transporter such as transporter P-glycoprotein (P-gp), multidrug resistance associated protein (MRP), breast cancer resistance protein (BCRP) was evaluated by RT-PCR. The antisense-phosphorothioate oligonucleotide (ASODN) including a translation initiation site of BCRP mRNA was transferred into resistant cells by liposome. RESULTS: Intracellular rhodamine fluorescence intensity of the resistant cells was 31.19% of that in the parental cells (P < 0.01). No expression of P-gp was demonstrated, and that of MRP was very weak in the TPT-resistant cells (relative expression value = 0.057). BCRP was overexpressed in the TPT-resistant cells (relative expression = 0.66), but not in the parental cells. Transfer of ASODN into resistant cells resulted in a 59.42% reduction of BCRP gene expression (P < 0.05) and an obviously increased intracellular rhodamine fluorescence intensity from 5.42 to 16.63 (P < 0.05). CONCLUSION: The overexpression of BCRP which mediated drug efflux may play an important role in the induction of TPT-resistance in ovarian cancer.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias Ováricas/tratamiento farmacológico , Topotecan/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/genética , Línea Celular Tumoral , Resistencia a Antineoplásicos , Femenino , Humanos , Proteínas de Neoplasias/genética , Neoplasias Ováricas/patología , ARN Mensajero/análisis
5.
Acta Pharmacol Sin ; 25(9): 1105-11, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15339383

RESUMEN

AIM: To investigate whether cyclin-dependent kinase 5 and its regulatory protein p35 was involved in staurosporine-induced apoptosis of cortical neuronal cultures. METHODS: Primary cerebral cortical neurons were exposed to 300 nmol/L staurosporine. After incubation for different time, morphological alterations were observed with phase-contrast microscopy, fluorescence microscopy, and transmission electron microscopy. DNA fragmentation was detected by agarose gel electrophoresis. The protein levels of Cdk4, p53, Cdk5, and its regulatory protein p35 following staurosporine treatment were measured by Western blotting. The Cdk5 activity was assayed for histone H1 kinase activity by autoradiography. RESULTS: The typical morphological changes of apoptosis were observed and the nuclear DNA fragmentation showed the characteristic "ladder" pattern after the cells were treated by staurosporine. The Cdk5 protein level increased markedly at 3 h and continued to 24 h. The p35 level increased at 3 h after being exposed to staurosporine, and decreased at 12 h. The cleavage of p35 to p25 was also detected at 12 h and increased at 24 h. There was no increase in Cdk5 kinase activity despite the increased cleavage of p35. The protein level of Cdk4 protein increased at 3 h and then decreased gradually from 6 h, but it was still higher than that in the vehicle cultures at 12 h. The p53 level decreased obviously at 3 h after staurosporine treatment and then seemed to increase at 12 h, but remained lower than that of vehicle cultures. CONCLUSION: Staurosporine-induced increase in Cdk5 protein levels and the cleavage of p35 to p25 may contribute to neuronal apoptosis.


Asunto(s)
Apoptosis/efectos de los fármacos , Corteza Cerebral/citología , Quinasas Ciclina-Dependientes/metabolismo , Fosfotransferasas/metabolismo , Estaurosporina/farmacología , Animales , Células Cultivadas , Corteza Cerebral/metabolismo , Quinasa 4 Dependiente de la Ciclina , Quinasa 5 Dependiente de la Ciclina , Fragmentación del ADN , Embrión de Mamíferos , Ratones , Proteínas del Tejido Nervioso/metabolismo , Neuronas/citología , Neuronas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo
6.
Ai Zheng ; 22(12): 1296-300, 2003 Dec.
Artículo en Zh | MEDLINE | ID: mdl-14693055

RESUMEN

BACKGROUND & OBJECTIVE: Breast cancer resistance protein (BCRP) was overexpressed in topotecan (TPT)-selected human ovarian cancer cell line A2780/TPT, strongly suggesting BCRP to be responsible for the drug-resistance of ovarian cancer. The current study was designed to investigate the reversal effect of BCRP antisense oligonucleotide (ASODN) on topotecan- resistant A2780/TPT cells. METHODS: The antisense-phosphorothioate oligonucleotide including the translation initiation site of BCRP mRNA was artificially synthesized, and the sense oligonucleotide (SODN) corresponding to the ASODN was also synthesized as control. Lipofect-2000 (LF) was used for the transfer of either ASODN or SODN into A2780/TPT cells. The changes of BCRP mRNA expression, intracellular fluorescence intensity of rhodamine and resistance index to topotecan of in vitro transfected A2780/TPT cells were detected respectively by reverse transcription-polymerase chain reaction (RT-PCR),flow cytometry (FCM),and methyl thiazolyl tetrazolium (MTT) assay. RESULTS: The transfer of ASODN/LF into A2780/TPT cells resulted in:(1)a 59.42% reduction of BCRP mRNA level (P< 0.05); (2)an obviously increased intracellular rhodamine fluorescence intensity from 5.42 to 16.63(P< 0.05); (3)a decreased resistance index to topotecan from 25 to 5 indicating sensitivity to topotecan in A2780/TPT cells recovered, as compared with non-transfected cell. But after transfecting SODN, no significant change could be measured. CONCLUSION: ASODN transfection may partly reverse BCRP-mediated drug- resistance of ovarian cancer cells.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/antagonistas & inhibidores , Antineoplásicos/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Proteínas de Neoplasias/antagonistas & inhibidores , Oligonucleótidos Antisentido/farmacología , Topotecan/farmacología , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/genética , Interacciones Farmacológicas , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Proteínas de Neoplasias/genética , Neoplasias Ováricas/patología , ARN Mensajero/biosíntesis , ARN Mensajero/efectos de los fármacos , Transfección , Células Tumorales Cultivadas
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