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1.
Angew Chem Int Ed Engl ; 63(13): e202318887, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38237082

RESUMEN

Trifluoromethyl cationic carbyne (CF3 C+ :) possessing dual carbene-carbocation behavior emulated as trifluoromethyl metal-carbynoid (CF3 C+ =M) has not been explored yet, and its reaction characteristics are unknown. Herein, a novel α-diazotrifluoroethyl sulfonium salt was prepared and used in Rh-catalyzed three-component [2+1+2] cycloadditions for the first time with commercially available N-fused heteroarenes and nitriles, yielding a series of imidazo[1,5-a] N-heterocycles that are of interest in medicinal chemistry, in which the insertion of trifluoromethyl Rh-carbynoid (CF3 C+ =Rh) into C=N bonds of N-fused heteroarenes was involved. This strategy demonstrates synthetic applications in late-stage modification of pharmaceuticals, construction of CD3 -containing N-heterocycles, gram-scale experiments, and synthesis of phosphodiesterase 10A inhibitor analog. These highly valuable and modifiable imidazo[1,5-a] N-heterocycles exhibit good antitumor activity in vitro, thus demonstrating their potential applications in medicinal chemistry.

2.
Nature ; 549(7670): 43-47, 2017 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-28825707

RESUMEN

Quantum key distribution (QKD) uses individual light quanta in quantum superposition states to guarantee unconditional communication security between distant parties. However, the distance over which QKD is achievable has been limited to a few hundred kilometres, owing to the channel loss that occurs when using optical fibres or terrestrial free space that exponentially reduces the photon transmission rate. Satellite-based QKD has the potential to help to establish a global-scale quantum network, owing to the negligible photon loss and decoherence experienced in empty space. Here we report the development and launch of a low-Earth-orbit satellite for implementing decoy-state QKD-a form of QKD that uses weak coherent pulses at high channel loss and is secure because photon-number-splitting eavesdropping can be detected. We achieve a kilohertz key rate from the satellite to the ground over a distance of up to 1,200 kilometres. This key rate is around 20 orders of magnitudes greater than that expected using an optical fibre of the same length. The establishment of a reliable and efficient space-to-ground link for quantum-state transmission paves the way to global-scale quantum networks.

3.
Science ; 356(6343): 1140-1144, 2017 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-28619937

RESUMEN

Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers.

4.
J Proteomics ; 114: 234-46, 2015 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-25486498

RESUMEN

TNF-α, one of the most potent pro-inflammatory cytokines, plays a critical role in inhibition of osteoblast differentiation and bone regeneration in persistent inflammatory microenvironment. To explore the mechanism, quantitative proteomics based on iTRAQ and MRM was employed. The results showed 6 proteins involved in BMP-2 induced osteoblast differentiation inhibition by TNF-α: Periostin, Protein S100-A4, ATPase inhibitor, Cytochrome b5, SERCA3, and ELP2. The altered proteins were involved in molecular transport, tissue development, energy metabolism, and inflammation. One specific protein, ELP2 (STAT3-interacting protein 1, StIP1) up-regulated in the inhibition of osteoblast differentiation by TNF-α was verified to play a critical role in STAT3 pathway. Overexpression or knockdown of ELP2 in C2C12 and MC3T3-E1 cells affected osteoblast differentiation inhibition induced by TNF-α. These results highlight the function of ELP2 in inflammatory microenvironment, ELP2 up-regulation and STAT3 pathway activation may down-regulate BMPR2, then BMP-2 was blocked and osteoblast differentiation inhibited. The protein-expression profile revealed here should offer at least partly new clues to understand the mechanism of osteoblast differentiation inhibition by inflammation. BIOLOGICAL SIGNIFICANCE: Persistent inflammation is always associated with osteogenesis and affects this balance to reduce bone mass including traumatic open bone fracture, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), but the cellular mechanisms are not fully elucidated. Tumor necrosis factor-α (TNF-α) is one of the most potent pro-inflammatory cytokines and is known to be a catabolic factor in these inflammatory reaction of diseases. We show for the first time using proteomics methods that in inflammatory microenvironment, osteoblast differentiation will be inhibited by TNF-α induced ELP2 up-regulation and STAT3 pathway activation. Our results are significant since they point to targeting ELP2 activity as a novel therapeutic option to limit the inhibition of osteoblast differentiation by inflammatory microenvironment.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular/fisiología , Osteoblastos/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología , Secuencia de Aminoácidos , Animales , Células Cultivadas , Microambiente Celular , Regulación hacia Abajo/efectos de los fármacos , Inflamación/metabolismo , Inflamación/patología , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Datos de Secuencia Molecular , Osteoblastos/fisiología , Mapeo de Interacción de Proteínas , Proteómica/métodos
5.
Dongwuxue Yanjiu ; 35(1): 42-50, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24470453

RESUMEN

Anurans often have species-specific vocalizations. To quantify and compare the characteristics of anuran calls in Gutianshan National Nature Reserve, Zhejiang Province, we recorded the advertisement calls of eight species belonging to four families (Ranidae, Microhylidae, Megophryidae and Bufonidae) from June to September 2012 using Sony ICD-FX8 IC recorders. All recordings were analyzed using the "Praat" software. Five acoustics parameters were measured, including temporal traits (call duration, number of notes or pulse number/call) and spectral traits (fundamental frequency, the first three formants and dominant frequency). The characteristic parameters of Microhyla ornate and Fejervarya limnocharis calls were different as were the calls of some populations of the same species recorded in different regions. The advertisement calls of the eight species were specific. Our study has provided a useful reference for identifying the calls of some common Chinese anurans.


Asunto(s)
Anuros/fisiología , Reproducción/fisiología , Estaciones del Año , Vocalización Animal/fisiología , Animales , China , Masculino
6.
Ann Vasc Surg ; 28(2): 301-5, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24183454

RESUMEN

BACKGROUND: The aim of this study was to determine the effectiveness and short-term outcomes of endovenous laser therapy (EVLT) combined with pinhole high ligation (PHL) in the treatment of great saphenous varicose veins. METHODS: From February 2011 to May 2012, 200 patients with great saphenous varicose veins were treated using combined EVLT and PHL. Sixty-eight of them had concurrent TriVex suction. There were 118 men and 82 women with a median age of 61 (range 28-82) years. All patients had more than one of the following presentations, including lower extremity heaviness, pain, edema, varicose vein, skin changes, or ulceration. Based on the CEAP clinical classification, 20 patients had C2, 85 had C3, 48 had C4, 23 had C5, and 24 had C6 chronic venous disease. Ninety patients had VV involving the left lower extremity, 56 involving the right lower extremity, and 54 involving the bilateral lower extremities. Duplex ultrasound (US) was performed for all the 200 patients, and showed great saphenous valve dysfunction and reflux in 148 patients. Fifty-two of the 200 patients had concurrent mild femoral vein reflux. Deep venous thrombosis (DVT) was ruled out in all the patients. RESULTS: Technical success rate of PHL and laser ablation was 100%. Median follow-up was 9 months, ranging from 3 to 20 months. Symptoms were resolved or significantly improved in all patients after surgery. The ulcers healed in 23 of the 24 patients (96%) within 3 months. Ten patients developed subcutaneous hematoma, and 8 had slightly worsening edema. Ten patients with complications of numbness due to saphenous nerve burning injury were treated with mecobalamin, and the numbness sensation improved within 1 month and disappeared within 3 months. Nine patients sustained saphenous vein thrombophlebitis postoperatively and were treated with ibuprofen and a heating pad. There was no recanalization of the great saphenous vein, deep venous thrombosis (DVT), or deaths in this group of patients. CONCLUSIONS: Combined EVLT and PHL are less invasive and are effective in the treatment of symptomatic great saphenous varicose veins. PHL prevents DVT, and significantly decreases recanalization of the great saphenous vein after endovenous laser ablation. Short-term outcomes have been satisfactory, but long-term follow-up is needed.


Asunto(s)
Procedimientos Endovasculares/métodos , Terapia por Láser , Vena Safena/cirugía , Várices/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Procedimientos Endovasculares/efectos adversos , Femenino , Humanos , Terapia por Láser/efectos adversos , Ligadura , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Vena Safena/diagnóstico por imagen , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía Doppler Dúplex , Várices/diagnóstico , Cicatrización de Heridas
7.
Artículo en Chino | MEDLINE | ID: mdl-22096855

RESUMEN

OBJECTIVE: To evaluate three alternative methods for LD50 test-Fixed Dose Procedure (FDP), the Acute Toxic Class Method (ATC) and Up and Down Procedure (UDP). METHODS: Female SD rats (8-12 weeks of age, 160-200 g) were used. Three alternative methods from OECD were applied to assess 22 chemicals (10 cosmetic raw materials and 12 raw materials of personal and home care products). The toxicity ranking for tested chemicals was established according to Globally Harmonized System (GSH). The results LD50 test were compared for the consistency and correlation between alternative methods and traditional test. RESULTS: For cosmetic raw materials, the concordance rate of the three alternative methods was 80% (8/10); for raw material of personal and home care products, the concordance rates of FDP, ATC and UDP was 91.7% (11/12), 75.0% (9/12) and 83.0% (10/12), respectively. The number of animals required in three alternative methods was significantly lower than that in traditional test (P < 0.05), but the time required in three alternative methods was significantly higher than that in traditional test (P < 0.05). CONCLUSIONS: High consistency and correlation were found between each alternative method and LD50 test. FDP may be more potential when applied to assess acute oral toxicity of cosmetic raw materials.


Asunto(s)
Cosméticos/toxicidad , Sustancias Peligrosas/toxicidad , Pruebas de Toxicidad Aguda/métodos , Administración Oral , Animales , Relación Dosis-Respuesta a Droga , Femenino , Dosificación Letal Mediana , Ratas , Ratas Sprague-Dawley
8.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 39(6): 610-7, 2010 11.
Artículo en Chino | MEDLINE | ID: mdl-21166055

RESUMEN

OBJECTIVE: To study the effects of combination of angiopoietin-1 (ANG-1) and vascular endothelial growth factor165 (VEGF165) gene transfer mediated by recombinant adeno-associated viral vector on the neovascularization in chronic ischemic porcine myocardium. METHODS: An ameroid constrictor was implanted around the left circumflex coronary artery (LCX) via endoscopy. Six weeks later, coronary angiography revealed that the myocardial ischemia was established by gradual occlusion of the left circumflex coronary artery (LCX). Sixteen swine with the total occlusion or partial stenosis (> 85 %) of the LCX were divided into 4 groups (4 in each group): group I, group II and group IV (control) received direct myocardium injection of rAAV2 VEGF165, rAAV2 ANG-1 or PBS alone, respectively; group III received rAAV2 VEGF165 and rAAV2 ANG-1. Selective coronary angiography and ultrasonography were performed perioperatively to evaluate the cardiac function and the formation of collateral circulation. The expression of VEGF165 and ANG-1 proteins were assessed using ELISA or Western blot. The degree of angiogenesis was assessed by use of immunohistochemical analysis. RESULT: Angiography showed that the occlusion of all LCX was completed or exceeded 95% 6 weeks after ameroid constrictor implantation, indicating the successful establishment of animal model. The expression levels of VEGF165 in group I and III and ANG-1 in groups II and III began to increase at d7 after transfection and reached the peak at d14; then decreased gradually to the normal level after 3 months. The expression levels of VEGF165 in group II and group IV or that of ANG-1 protein in group I and group IV had no markedly changes at different time after transfection. There were significant increase in capillary density and arteriole density and more side branch vessels formed in group III compared with other groups. Echocardiographic measurements showed that the left ventricular systolic function of animals in groups I, II and III increased significantly after gene transfection, especially in group III; but there was no changes in group IV. CONCLUSION: Myocardial perfusion and the left ventricular systolic function are improved after rAAV2 VEGF165 or rAAV2 ANG-1 transfection, which is associated with the angiogenesis in porcine model of chronic myocardial ischemia.


Asunto(s)
Angiopoyetina 1/genética , Isquemia Miocárdica/fisiopatología , Neovascularización Fisiológica , Factor A de Crecimiento Endotelial Vascular/genética , Adenoviridae/genética , Animales , Circulación Colateral , Vasos Coronarios/fisiopatología , Modelos Animales de Enfermedad , Terapia Genética , Vectores Genéticos , Masculino , Isquemia Miocárdica/terapia , Porcinos , Porcinos Enanos , Transfección
9.
Artículo en Inglés | MEDLINE | ID: mdl-12237707

RESUMEN

Studies on the peroxidation of polyunsaturated fatty acid from yolk lipoprotein induced by iron was curried out. A comparison of the experimental conditions for the model system of peroxidation was made. The system was successfully applied to determine the activity of the anti-oxidative activity of some effective ingredients of Chinese traditional medicine.

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