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OBJECTIVE: To study the extraction system of hirudin emulsion liquid membrane with the Poecilobdella manillensis as raw material, di-(2-ethylhexyl) phosphate (D2EHPA) as carrier, Span 80 as emulsifier, octane and D2EHPA mixed to constitute membrane solution, diluted HCl solutions as internal aqueous phase. METHOD: Using the orthogonal experiment to optimize the extraction conditions of hirudin reference substance such as membrane phase, internal aqueous phase volume ratio (MIPVR), external aqueous phase pH, internal aqueous phase pH, mobile carrier concentration and so on, and then using hirudin crude extracts to do purifying experiment, and gaining experimental samples. RESULT: The optimal conditions of hirudin extraction were as follows: MIPVR 10: 3, internal aqueous phase pH 2.6, external aqueous phase pH 3.4, the mass fraction of carrier D2EHPA 2%. In the optimal extraction conditions, when the initial concentration of hirudin was one anti-thrombin activity units (ATU) x mL(-1), ATU recovery rate of the reference substance was 83.06%. In the purifying experiment of crude extracts, ATU recovery rate was 82.99%, and the specific activity of sample was 3 289.48 the ATU x mg(-1). Discontinuous polyacrylamide gel electrophoresis and spectral scanning, the results showed that the purity and reference substance were considerable. CONCLUSION: The method of preparation hirudin was relatively simple, the purity of the experimental samples and ATU recovery were both high.
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Hirudinas/aislamiento & purificación , Sanguijuelas/química , Extracción en Fase Sólida/métodos , Animales , Emulsiones/química , Hirudinas/análisis , Membranas Artificiales , Extracción en Fase Sólida/instrumentaciónRESUMEN
The transmittance of one-dimensional photonic crystals consisting of superconductor and lossless dielectric has been systematically studied through the transfer-matrix method. Obviously, the shift of the photonic bandgap (PBG) becomes more noticeable by adjusting the thicknesses of the dielectric layers than that of superconductor layers. Furthermore, the number of PBGs can be controlled by varying the thicknesses of dielectric layers. Compared to the thicknesses of the dielectric layers, the width of the PBGs is more sensitive to the thicknesses of the superconductor layers. However, the width of the first PBG promptly varies when the thicknesses of the dielectric layers increase from 0 to 40 nm. If the contribution of the normal conducting electrons of the superconductor is nonnegligible, the temperature of the superconductor has no influence on the width of the PBGs. Moreover, the damp coefficient does not affect the PBGs under low-temperature conditions.
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BACKGROUND: Zeaxanthin, a carotenoid commonly found in plants, has a variety of biological functions including anti-cancer activity. PURPOSE: This study aimed to investigate the potential mechanisms of zeaxanthin in human gastric cancer cells. METHODS: CCK-8 assay was used to examine the cytotoxic effect of zeaxanthin on human gastric cancer cells. Flow cytometry was used to analyse AGS cell cycle distribution and apoptosis status. Western blot analysis was used to detect the expression levels of cycle-related proteins (Cyclin A, Cyclin B1, CDK1/2, p21, and p27), apoptosis-related proteins (Bcl-2, Bad, caspase-3, PARP), MAPK, AKT, STAT3, and NF-κB. RESULTS: CCK-8 assay showed that zeaxanthin has obvious cytotoxic effects on 12 types of human gastric cancer cells, but no obvious toxic effect on normal cells. In addition, flow cytometry and Western blotting results showed that zeaxanthin induces apoptosis by reducing mitochondrial membrane potential; increasing Cytochrome C, Bax, cleaved-caspase-3 (cle-cas-3), and cleaved-PARP (cle-PARP) expression levels; and decreasing Bcl-2, pro-caspase-3 (pro-cas-3), and pro-PARP expression levels. Additionally, zeaxanthin caused cell cycle arrest at the G2/M phase by increasing the levels of p21 and p27 and reduced the levels of AKT, Cyclin A, Cyclin B1, and Cyclin-dependent kinase 1/2 (CDK1/2). Furthermore, after zeaxanthin treatment, the expression levels of reactive oxygen species (ROS), p-JNK, p-p38, and I-κB increased, and the expression levels of p-ERK, p-AKT, STAT3, and NF-κB decreased. However, the ROS scavenger N-acetylcysteine (NAC) and MAPK inhibitors inhibited zeaxanthin-induced apoptosis, and under the action of zeaxanthin, MAPK regulated NF-κB and STAT3, and reduced their protein expression levels. CONCLUSION: Zeaxanthin has a potential effect against gastric cancer cells through the ROS-mediated MAPK, AKT, NF-κB, and STAT3 signaling pathways, and it is expected to become a new drug for the treatment of human gastric cancer.
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10-Hydroxy-2-decenoic acid (10-HDA), also known as royal jelly acid, has a variety of physiological functions, and recent studies have shown that it also has anticancer effects. However, its anticancer mechanisms have not been clearly defined. In this study, we investigated the underlying mechanisms of 10-HDA in A549 human lung cancer cells. We used Cell Counting Kit-8 assay, scratch wound healing assay, flow cytometry, and western blot analysis to investigate its apoptotic effects and underlying mechanism. Our results showed that 10-HDA inhibited the proliferation of three types of human lung cancer cells and had no significant toxic effects on normal cells. Accompanying reactive oxygen species (ROS), 10-HDA induced A549 cell apoptosis by regulating mitochondrial-associated apoptosis, and caused cell cycle arrest at the G0/G1 phase in a time-dependent manner. Meanwhile, 10-HDA also regulated mitogen-activated protein kinase (MAPK), signal transducer and activator of transcription 3 (STAT3), and nuclear factor kappa B (NF-κB) signaling pathways by increasing the expression levels of phosphorylated c-Jun N-terminal kinase, p-p38, and I-κB, and additionally, by decreasing the expression levels of phosphorylated extracellular signal-regulated kinase, p-STAT3, and NF-κB. These effects were blocked by MAPK inhibitors and N-acetyl-L-cysteine. Furthermore, 10-HDA inhibited cell migration by regulating transforming growth factor beta 1 (TGF-ß1), SNAI1, GSK-3ß, E-cadherin, N-cadherin, and vimentin. Taken together, the results of this study showed that 10-HDA induced cell cycle arrest and apoptosis in A549 human lung cancer cells through ROS-mediated MAPK, STAT3, NF-κB, and TGF-ß1 signaling pathways. Therefore, 10-HDA may be a potential therapy for human lung cancer.
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Ácidos Grasos Monoinsaturados/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Subunidad p50 de NF-kappa B/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Factor de Crecimiento Transformador beta1/metabolismo , Células A549 , Apoptosis/efectos de los fármacos , Ciclo Celular , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Regulación Enzimológica de la Expresión Génica , Humanos , Sistema de Señalización de MAP Quinasas , Potenciales de la Membrana , Mitocondrias/metabolismo , Fosforilación , Especies Reactivas de Oxígeno/metabolismoRESUMEN
OBJECTIVE: To investigate the early diagnosis on iatrogenic injuries in distal part of common bile duct and the prevention of severe retroperitoneal infection. METHODS: From 1990 to 2004, 17 patients with bile duct injures in the distal part of common biliary tract were admitted. And the clinical data of the 17 cases were retrospectively analyzed. RESULTS: Of the 17 cases, the injuries of 15 cases were caused by the operation, and the injuries of the other 2 cases were caused in the process of removing the stone by endoscopic retrograde cholangiopancreatography (ERCP). The injuries of 14 cases were found during the operation, but the other one was not found in time. Before the operation, 16 cases were examined by B-type ultrasonography, 2 by MRCP and 6 by intraoperative choledocho-endoscope after the biliary tract exploration. Ten cases underwent perforating suture repair and T-tube drainage; 2 with Odd's sphincter incision and shaping; 2 with choledochojejunostomy; 1 with duodenum wall and bile duct repair and drainage. When the bile duct injured, the major findings during operation were bile duct explorer located out of the duodenum wall and bile duct, two or more than cleft in the distal part of common biliary tract found by choledocho-endoscopic examination, retroperitoneal edema and liquid accumulation found by irrigating water through T-tube, and/or retroperitoneal tissues stained blue by irrigating methylthioninium chloride through T-tube. The clinical manifestations after injuries were abdominal distention, abdominal pain, pain in the waist and back, fever and shock, et al. Thirteen cases were cured. And the syndromes included 1 case with intestinal fistula, 1 with incisional infection, 4 dead (3 died from infectious shock; 1 from bleeding in gastrectomy). CONCLUSIONS: The postoperative clinical manifestations for iatrogenic injuries in the distal part of common biliary tract lack specificity, CT examinations are necessary to doubtful patients. Early diagnosis and timely management can obtain better results, and can effectively lower severe retroperitoneal infection. The perfect preoperative imaging examinations and intraoperative choledocho-endoscopic examinations before the biliary tract exploration maybe reduce iatrogenic injuries in the distal part of common biliary tract.
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Conducto Colédoco/lesiones , Conducto Colédoco/cirugía , Enfermedad Iatrogénica , Complicaciones Intraoperatorias , Adulto , Anciano , Femenino , Humanos , Enfermedad Iatrogénica/prevención & control , Complicaciones Intraoperatorias/diagnóstico por imagen , Complicaciones Intraoperatorias/cirugía , Masculino , Persona de Mediana Edad , Peritonitis/prevención & control , Radiografía , Estudios RetrospectivosRESUMEN
Tailoring electromagnetically induced transparency with two different coupling mechanisms has been numerically demonstrated. The results show that EIT based on simultaneous electric resonance and magnetic resonance has relatively larger coupling distance compared with that based on electric resonance near field coupling to magnetic resonance. The relatively large coupling distance is due to the relatively small susceptibility change. For EIT based on simultaneous electric resonance and magnetic resonance, not only incident electric field but also the incident magnetic field pays a role on the susceptibility of system. The influence of the incident magnetic field leads to relatively smaller susceptibility change compared with that based on electric resonance near field coupling to magnetic resonance.
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The well-known Kerr effect in isotropic fluids consists in the appearance of uniaxial orientational order and birefringence that grows as the square of the applied electric field. We predict and observe that at a high electric field, the Kerr effect displays features caused by the nonlinear dependence of dielectric permittivity on the field-induced orientational order parameter. Namely, the field-induced birefringence grows faster than the square of the electric field and the dynamics of birefringence growth slows down as the field increases. As a function of temperature, the field-induced birefringence is inversely proportional to the departure from an asymptotic critical temperature, but this temperature is no longer a constant (corresponding to the lower limit of the supercooled isotropic phase) and increases proportionally to the square of the electric field.