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1.
Phys Rev Lett ; 120(13): 132505, 2018 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-29694189

RESUMEN

We report on the first observation of γ rays emitted from an sd-shell hypernucleus, _{Λ}^{19}F. The energy spacing between the ground state doublet, 1/2^{+} and 3/2^{+} states, of _{Λ}^{19}F is determined to be 315.5±0.4(stat)_{-0.5}^{+0.6}(syst) keV by measuring the γ-ray energy of the M1(3/2^{+}→1/2^{+}) transition. In addition, three γ-ray peaks are observed and assigned as E2(5/2^{+}→1/2^{+}), E1(1/2^{-}→1/2^{+}), and E1(1/2^{-}→3/2^{+}) transitions. The excitation energies of the 5/2^{+} and 1/2^{-} states are determined to be 895.2±0.3(stat)±0.5(syst) and 1265.6±1.2(stat)_{-0.5}^{+0.7}(syst) keV, respectively. It is found that the ground state doublet spacing is well described by theoretical models based on existing s- and p-shell hypernuclear data.

2.
Allergy ; 73(2): 387-394, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28871603

RESUMEN

BACKGROUND: The overproduction of IgE plays a critical role in the pathogenesis of allergy; the mechanism is unclear. Histone-acetyltransferase (HAT) activities are required in gene transcription of a large number of molecules in the immune system of the body. OBJECTIVES: This study tests a hypothesis that HAT Tat-interactive protein 60 (Tip60) plays an important role in the initiation of IgE-mediated allergy. METHODS: The effects of Tip60 on regulating IgE expression were assessed with B cells. An intestinal allergy mouse model was developed to assess the role of Tip60 in the induction of IgE-mediated allergic inflammation. RESULTS: High levels of Tip60 were observed in the peripheral B cells of patients with FA. Tat-interactive protein 60 (Tip60) was required in the expression of IgE and IgG1 in B cells by inducing the chromatin remolding at the gene locus, in which histone acetylation, signal transducer and activator of transcription 6 (STAT6), and nuclear factor-κB at the locus of Iε promoter were markedly increased. Blocking Tip60 significantly attenuated the allergic inflammation in the mouse intestinal mucosa. CONCLUSIONS: Tat-interactive protein 60 (Tip60) plays an important role in the induction of IgE in B cells. Blocking Tip60 inhibits the allergic inflammation in the intestine, suggesting Tip60 inhibitor may be a potential anti-allergy drug.


Asunto(s)
Hipersensibilidad/genética , Hipersensibilidad/inmunología , Enfermedades Intestinales/genética , Enfermedades Intestinales/inmunología , Lisina Acetiltransferasa 5/genética , Lisina Acetiltransferasa 5/inmunología , Adulto , Animales , Modelos Animales de Enfermedad , Femenino , Histona Acetiltransferasas , Humanos , Inmunoglobulina E/genética , Inmunoglobulina E/inmunología , Intestinos/inmunología , Masculino , Ratones
5.
Phys Rev Lett ; 117(1): 011801, 2016 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-27419562

RESUMEN

We report the first observation of the decay Λ_{c}^{+}→pK^{+}π^{-} using a 980 fb^{-1} data sample collected by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. This is the first observation of a doubly Cabibbo-suppressed decay of a charmed baryon. We measure the branching ratio of this decay with respect to its Cabibbo-favored counterpart to be B(Λ_{c}^{+}→pK^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})=(2.35±0.27±0.21)×10^{-3}, where the uncertainties are statistical and systematic, respectively.

6.
Genet Mol Res ; 15(2)2016 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-27420979

RESUMEN

The bovine TRIM28 gene was amplified from ovary tissue by using RT-PCR. The TRIM28 gene was inserted into the eukaryotic expression vector pIRES2-EGFP and transfected into bovine fetal fibroblasts by using Lipofectamine 3000. TRIM28 mRNA and protein were detected by fluorescence microscope and western blotting. The results showed that the full length of TRIM28 was cloned and pIRES2-EGFP-TRIM28 was constructed successfully. EGFP expression was observed, and the pIRES2-EGFP-TRIM28 transfected group expressed more TRIM28 protein than that by the pIRES2-EGFP group. The TIMR28 gene has been successfully transferred into bovine fetal fibroblasts.


Asunto(s)
Proteínas Represoras/genética , Animales , Bovinos , Células Cultivadas , Clonación Molecular , Femenino , Fibroblastos/metabolismo , Vectores Genéticos/genética , Ovario/metabolismo , Proteínas Represoras/metabolismo
7.
Genet Mol Res ; 14(2): 6256-64, 2015 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-26125827

RESUMEN

Several previous studies have investigated whether the FCGR2A gene H131R polymorphism confers an increased risk of Kawasaki disease (KD), but conflicting results have been reported. To further explore the association of this polymorphism with KD susceptibility, we performed an extensive search of relevant studies and conducted a meta-analysis to obtain a more precise estimate of risk. Systematic searches of the electronic databases Embase, PubMed, and Google Scholar were performed to identify relevant studies. Odds ratios (ORs) and their 95% confidence intervals (CIs) were used for statistical analysis. Six studies were included in the meta-analysis, involving 1709 patients with KD and 3207 controls. Significant association was found between the FCGR2A gene H131R polymorphism and KD risk in analysis of the total population (HH vs RR: OR = 1.97, 95%CI = 1.55-2.50; HH vs HR: OR = 1.38, 95%CI = 1.21-1.57; the dominant model: OR = 0.69, 95%CI = 0.60-0.78; and the recessive model: OR = 1.65, 95%CI = 1.32-2.07). In subgroup analysis by ethnicity, significant association was found between the H131R polymorphism and KD risk in Asians, but not in Caucasians. In addition, we found no significant association between the FCGR2A gene H131R polymorphism and risk of KD-associated coronary artery lesions. In conclusion, this meta-analysis suggested that the H131R polymorphism in the FCGR2A gene might be associated with susceptibility to KD in Asians.


Asunto(s)
Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Síndrome Mucocutáneo Linfonodular/genética , Receptores de IgG/genética , Pueblo Asiatico/genética , Humanos , Síndrome Mucocutáneo Linfonodular/patología , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Población Blanca/genética
8.
Genet Mol Res ; 14(2): 2986-93, 2015 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-25966062

RESUMEN

Bisphenol A (BPA) is an industrial contaminant and is reported to be a risk factor associated with the development of tumors. In our previous studies, we have shown that BPA promoted the growth of SK-N-SH human neuroblastoma cells and increased their invasion and metastasis. In this study, we further investigated the effects of BPA and 17ß-estradiol (E2) on the stem cell-like cells from SK-N-SH cells. Detection of stem cell markers, proliferation assay, and clonogenic analysis showed that the side-population (SP) of SK-N-SH cells had properties similar to those of stem cells. BPA or E2 exposure decreased the percentage of SP cells and the expression of stem cell-marker proteins. BPA and E2 promoted the growth of non-SP cells to a greater extent than of SP cells; in addition, they significantly increased the growth of SP cells. Thus, BPA has effects on stem cell-like cells, which induce tumor formation, and thus, BPA is an environmental factor that plays an important role in the development of neuroblastoma.


Asunto(s)
Compuestos de Bencidrilo/toxicidad , Células Madre Neoplásicas/efectos de los fármacos , Neuroblastoma/patología , Fenoles/toxicidad , Procesos de Crecimiento Celular/efectos de los fármacos , Línea Celular Tumoral , Estradiol/toxicidad , Humanos , Células Madre Neoplásicas/patología
9.
Colorectal Dis ; 16(4): 259-64, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24118729

RESUMEN

AIM: High-risk patients with Stage II colon cancer may benefit from adjuvant chemotherapy, but it is difficult to identify such a patient group. A robust and reproducible index would be helpful to select the subset of Stage II colon cancer patients at high risk. This study investigated the potential prognostic significance of tumour budding in Stage II colon cancer. METHOD: In all, 135 Stage II colon cancer patients with known outcome were identified. The degree of tumour budding was assessed by two individual observers and was classified, according to the number of tumour buds in the area with the greatest budding intensity on haematoxylin and eosin slides, as high-grade budding (10 or more tumour buds) and low-grade budding (0-9 buds). Inter-observer agreement for two observers was assessed by using the kappa test. Progression-free and cancer-specific survivals were analysed using the Kaplan-Meier method and Cox regression. RESULTS: The 5-year progression-free survival rates for patients with high-grade tumour budding (n = 36) and those with low-grade budding (n = 99) were 57.6% and 89.0% (P < 0.001). The 5-year cancer-specific survival rates were 66.7% vs 92.0% (P < 0.001). Cox regression analyses demonstrated tumour budding as an independent predictor of disease progression (hazard ratio 4.982, P < 0.001) and cancer-related death (hazard ratio 4.142, P = 0.003). The two observers agreed on the classification of tumour budding in 118 cases (87.4%) and the inter-observer agreement was good (κ = 0.692). CONCLUSION: Tumour budding is a strong and reproducible prognostic factor for adverse outcome in Stage II colon cancer, which may serve as a prognostic marker to identify patients with a high risk of recurrence who may benefit from adjuvant therapy.


Asunto(s)
Carcinoma/patología , Neoplasias del Colon/patología , Recurrencia Local de Neoplasia/patología , Medición de Riesgo , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Adulto Joven
10.
Bull Environ Contam Toxicol ; 92(1): 71-4, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24162647

RESUMEN

The chronic toxic effects of major heavy metals including copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) on the filtration rate (FR), sex ratio, and gonad development of immature blood clams, Tegillarca granosa, were investigated. The FRs were significantly inhibited by Cu, Pb and Cd, with rates generally decreasing with both increasing metal concentrations and exposure time. EC50 values for FR after 28 days of exposure were 12.9, 12.7 and 14.4 µg/L for Cu, Pb and Cd, respectively. Zn exposure had no effect on FR. Sex ratios were significantly altered from controls in favor of an increased proportion of males at metal concentrations of ≥ 14.2, ≥ 86 and ≥ 110 µg/L for Cu, Pb and Cd, respectively; and at ≥ 1.68 mg/L for Zn. The gonado-somatic index was significantly reduced in clams at all metal exposures, except for the lowest concentration of Cu (7.1 µg/L).


Asunto(s)
Bivalvos/metabolismo , Gónadas/crecimiento & desarrollo , Metales Pesados/metabolismo , Razón de Masculinidad , Contaminantes Químicos del Agua/metabolismo , Animales , Disruptores Endocrinos/metabolismo , Disruptores Endocrinos/toxicidad , Femenino , Gónadas/efectos de los fármacos , Masculino , Metales Pesados/toxicidad , Contaminantes Químicos del Agua/toxicidad
12.
Genet Mol Res ; 11(3): 1841-50, 2012 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-22869540

RESUMEN

We examined a possible relationship -420C>G SNP of the resistin gene with plasma resistin and C-reactive protein concentrations in intracerebral hemorrhage. Three hundred and forty-four Chinese Han patients with intracerebral hemorrhage and 344 age- and gender-matched healthy controls were included in our study. Plasma resistin and C-reactive concentrations were measured and SNP -420C>G was genotyped. The genotype frequencies in controls and patients were not significantly different (P = 0.672). Plasma resistin and C-reactive protein levels were significantly different between the SNP -420C>G genotypes, even after adjustment for age, gender and body mass index. The common homozygote (C-C) had the lowest resistin and C-reactive protein plasma concentrations; the plasma resistin and C-reactive protein concentrations in the heterozygote (C-G) and the rare allele homozygote (G-G) did not differ significantly. Plasma resistin levels were significantly associated with plasma C-reactive protein level. We conclude that SNP -420C>G of the resistin gene could be involved in the inflammatory component of intracerebral hemorrhage through enhanced production of resistin.


Asunto(s)
Pueblo Asiatico/genética , Hemorragia de los Ganglios Basales/genética , Proteína C-Reactiva/metabolismo , Etnicidad/genética , Polimorfismo de Nucleótido Simple/genética , Resistina/sangre , Resistina/genética , Anciano , Anciano de 80 o más Años , Hemorragia de los Ganglios Basales/sangre , China , Femenino , Frecuencia de los Genes/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad
13.
Zhonghua Liu Xing Bing Xue Za Zhi ; 42(9): 1615-1620, 2021 Sep 10.
Artículo en Zh | MEDLINE | ID: mdl-34814592

RESUMEN

Objective: To investigate the incidence and determinants of vaccine hesitancy towards national immunization program in China and understand the current status of parents' hesitancy to different vaccines used in national immunization program. Methods: A cross-sectional survey was conducted in Beijing, Sichuan and Gansu. The methods of proportional probability sampling and convenience sampling were used to select the eligible study subjects for questionnaire surveys. Results: A total of 3 592 parents were enrolled in the study, in whom 38.22% fully accepted all the vaccines, 59.35% agreed to let their children to receive all the vaccines but showed slight concern, and 2.42% had hesitancy to the vaccines. The vaccine with the most hesitancy was polio vaccine (0.89%), followed by diphtheria pertussis tetanus vaccine (0.70%) and hepatitis A vaccine (0.64%). The dominant reason for vaccine hesitancy was the risk-benefit perception of vaccination (31.03%), followed by the low awareness of the parents (21.84%) and the inconvenience caused by distance and time (21.84%). Conclusions: The incidence of vaccine hesitancy towards national immunization program was low in parents in China, but over 50% of the parents showed concern to the vaccines. It is essential to improve the service quality of national immunization program and strengthen the health education about the vaccination to reduce the incidence of vaccine hesitancy in parents.


Asunto(s)
Vacunas , Niño , China/epidemiología , Estudios Transversales , Vacuna contra Difteria, Tétanos y Tos Ferina , Conocimientos, Actitudes y Práctica en Salud , Humanos , Programas de Inmunización , Padres , Vacunación
14.
Zhonghua Wei Chang Wai Ke Za Zhi ; 23(5): 451-455, 2020 May 25.
Artículo en Zh | MEDLINE | ID: mdl-32842423

RESUMEN

Presacral recurrence, a special recurrence type in rectal cancer after surgical treatment, refers to recurrent cancer invading the presacral soft tissue or the bony structure of sacrum. It is also a major constituent of recurrent rectal cancer (15.63% to 41.67%). Reports show that presacral recurrence rate is about 2.8% to 4.8%, and it is associated with clinic staging, pathological type, surgical approach, (neo) adjuvant radiochemotherapy, tumor distance from the anus, positive circumferential margin, lymph node metastasis, and unilateral lateral lymph node dissection. CT and MRI are important for the detection of presacral recurrence. Presacral recurrence is always combined with local recurrence in other parts and distant organ metastasis. Therefore, we divide that into the following 3 types: 1) presacral recurrence with distant metastasis; 2) presacral recurrence with pelvic wall or lateral lymph node metastasis, or with recurrence of pelvic organs or anastomosis; and 3) simple presacral relapse. According to MDT evaluation. We adopt corresponding treatment scheme and surgical approach depending on the types mentioned above. When tumor recurred in the sacrum and located lower than S2/3 articular surface, then resection of recurrent tumor combined with sacrococcygeal should be the treatment of choice. For presacral recurrence with anterior invasion, combined total pelvic exenteration were available. For presacral recurrence with lateral pelvic wall invasion, internal iliac arteriovenous resection and lateral lymph node dissection and para-aortic lymph node dissection should be carried out. R0 resection may improve the 5-year overall survival rate of these patients.


Asunto(s)
Recurrencia Local de Neoplasia/epidemiología , Recurrencia Local de Neoplasia/cirugía , Neoplasias del Recto/epidemiología , Neoplasias del Recto/cirugía , Sacro/cirugía , Humanos , Escisión del Ganglio Linfático , Ganglios Linfáticos/patología , Ganglios Linfáticos/cirugía , Metástasis Linfática , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/terapia , Neoplasias del Recto/patología , Neoplasias del Recto/terapia , Sacro/patología
15.
Eur Rev Med Pharmacol Sci ; 21(8): 1828-1836, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28485796

RESUMEN

OBJECTIVE: Epigenetic mechanisms, such as microRNA, histone modification, and DNA methylation, are critical for dysregulated gene expression in heart failure (HF). However, the relationship between DNA methylation and dysregulated gene expression of blood leukocytes during HF remains unclear. PATIENTS AND METHODS: In this study, DNA methylation status and gene expression in blood leukocytes from ischemic end-stage cardiomyopathy patients were compared to normal controls by using reduced representation bisulfite sequencing (RRBS), and the results were validated by quantitative MassARRAY analysis and RT-qPCR. RESULTS: Three differentially methylated genes between two groups were identified. Furthermore, the differential expression of each corresponding gene was found to be correlated with differential DNA methylation. Diverse blood leukocyte DNA methylations existed in HF patients, which were correlated with differential expression of corresponding genes. CONCLUSIONS: Therefore, detecting DNA methylation in blood leukocytes could be an attractive approach for HF study.


Asunto(s)
Metilación de ADN , Epigénesis Genética , Insuficiencia Cardíaca/genética , Leucocitos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad
16.
Cardiovasc Intervent Radiol ; 40(12): 1866-1872, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28779218

RESUMEN

PURPOSE: To evaluate the incidence, management methods and follow-up results of arterial embolism during percutaneous thrombectomy of hemodialysis grafts. MATERIALS AND METHODS: After Institutional Review Board approval, the radiologic database of our department for percutaneous thrombectomy procedure in hemodialysis access was retrospectively reviewed. Between 1998 and June 2014, 2975 percutaneous thrombectomy procedures using thromboaspiration technique were performed in 1524 patients with thrombosed hemodialysis grafts. After thrombectomy, angioplasty was performed for significant stenoses. The incidence of arterial embolism was analyzed according to the location/shape of the arteriovenous graft. Percutaneous management methods of arterial embolism and long-term follow-up results by fistulography were also evaluated. RESULTS: Arterial embolism was documented by angiography in 117 cases (3.9%). Of these, three were symptomatic and subsided after embolectomy. The incidence was significantly correlated with the location/shape of the graft (p = 0.001). Arterial emboli were retrieved using occlusion balloon/Fogarty balloon (n = 58), guiding catheter-assisted aspiration (n = 36), sheath-assisted aspiration (n = 2) and back-bleeding technique (n = 3). Others were observed without intervention (n = 17) or surgically removed (n = 1). Arterial emboli were completely retrieved in 86 cases and partially retrieved in 13 cases. Ulnar artery rupture occurred in one case due to over-inflation of the occlusion balloon. Follow-up fistulography performed in 60 patients among whom 99 percutaneous embolectomies were done revealed arterial stenosis/occlusion in 7 and residual emboli in one patient. In observed patients without intervention, follow-up documented complete resolution of the emboli without arterial stenosis in 9 patients. CONCLUSION: Radiologically perceivable arterial embolism is uncommon during percutaneous thrombectomy of thrombosed dialysis grafts. The majority of the emboli can be retrieved by percutaneous techniques, but may induce arterial damage in some patients. Clinical observation can be another option for patients without ischemic symptoms.


Asunto(s)
Derivación Arteriovenosa Quirúrgica , Complicaciones Posoperatorias/epidemiología , Diálisis Renal , Trombectomía/métodos , Tromboembolia/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Angiografía/métodos , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico por imagen , Estudios Retrospectivos , Tromboembolia/diagnóstico por imagen , Adulto Joven
17.
Zhonghua Liu Xing Bing Xue Za Zhi ; 37(12): 1574-1577, 2016 Dec 10.
Artículo en Zh | MEDLINE | ID: mdl-27998401

RESUMEN

Objective: To understand the prevalence of domestic violence and the correlation between domestic violence and posttraumatic stress disorder (PTSD) so as to improve the mental health status of women in Wuhan city of China. Methods: A cross-sectional study was conducted in the community health service center in Wuhan. Participants were women who came to the center for gynecological examination. Data on general condition, social support, injury, epidemiological characteristics of domestic violence and PTSD were gathered. Chi-square, student-t and Cochran-Armitage trend tests were employed to compare the distribution of each characteristic variable between PTSD and non-PTSD group. Binary logistic regression was used to analyze the correlation between domestic violence and PTSD. Results: A total of 1 015 women were effectively surveyed. The life-time incidence rates of events related to domestic, psychological, physical and sexual violence were 29.36%, 28.28%, 6.60% and 3.55%, respectively. The overall prevalence rate of PTSD was 4.73%. Women who suffered from domestic violence had higher risk of PTSD (OR=2.11, 95%CI: 1.04-4.29) than those who never experiencing domestic violence. Women who suffered from psychological or physical violence were 5.06 times more likely to suffer from PTSD (OR=5.06, 95% CI: 1.91-13.42). Conclusion: A strong correlation between domestic violence and PTSD was seen. Victims who suffered from domestic violence should be provided with psychological counseling to reduce the risk of PTSD.


Asunto(s)
Violencia Doméstica , Trastornos por Estrés Postraumático , China , Estudios Transversales , Femenino , Humanos , Prevalencia , Riesgo , Apoyo Social , Encuestas y Cuestionarios
18.
Mol Cell Endocrinol ; 230(1-2): 51-8, 2005 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-15664451

RESUMEN

In pancreatic beta-cells, inhibition of K(ATP)-channels plays a pivotal role in signal transduction of glucose-induced insulin release. However, the extreme sensitivity of K(ATP)-channels to its ligand ATP as found in inside-out patches is not directly compatible with modulation of these channels at physiological [ATP](i). We studied K(ATP)-channel sensitivity to ATP in beta-cells in dispersed culture and in fresh pancreatic tissue slices. Physiological [ATP](i) blocks more than 99% of K(ATP)-channels in cultured beta-cells, while only 90% in beta-cells in slices, indicating reduced sensitivity to ATP in the fresh slices. Applying cytosolic factors like ADP, phosphatidylinositol-4,5-bisphosphate (PIP(2)) or oleoyl-CoA did not restore the K(ATP)-channel sensitivity in cultured beta-cells. Our data suggest that interaction between SUR1 and Kir6.2 subunit of the K(ATP)-channel could be a factor in sensitivity modulation. Tissue slices are the first beta-cell preparation to study direct K(ATP)-channel modulation by physiological [ATP](i).


Asunto(s)
Adenosina Trifosfato/farmacología , Islotes Pancreáticos/efectos de los fármacos , Canales de Potasio de Rectificación Interna/antagonistas & inhibidores , Animales , Células Cultivadas , Humanos , Masculino , Ratones , Técnicas de Cultivo de Tejidos
19.
IEEE Trans Image Process ; 10(5): 677-85, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-18249658

RESUMEN

Although the side-match vector quantizer (SMVQ) reduces the bit rate, the image coding quality by SMVQ generally degenerates as the gray level transition across the boundaries of the neighboring blocks is increasing or decreasing. This study presents a smooth side-match method to select a state codebook according to the smoothness of the gray levels between neighboring blocks. This method achieves a higher PSNR and better visual perception than SMVQ does for the same bit rate. Moreover, to design codebooks, a genetic clustering algorithm that automatically finds the appropriate number of clusters is proposed. The proposed smooth side-match classified vector quantizer (SSM-CVQ) is thus a combination of three techniques: the classified vector quantization, the variable block size segmentation and the smooth side-match method. Experimental results indicate that SSM-CVQ has a higher PSNR and a lower bit rate than other methods. Furthermore, the Lena image can be coded by SSM-CVQ with 0.172 bpp and 32.49 dB in PSNR.

20.
Zhongguo Zhong Yao Za Zhi ; 26(11): 755-7, 2001 Nov.
Artículo en Zh | MEDLINE | ID: mdl-12776345

RESUMEN

OBJECTIVE: To extract and separate deoxyschisandrin, gamma-schisandrin, etc in fruits of Schisandra sphenanthera by supercritical carbon dioxide fluid extraction technology. METHOD: Optimum extraction conditions were studied by orthogonal tests and deoxyschisandrin, gamma-schisandrin, wuweizi chun A, wuweizi ester A were analyzed by HPLC. RESULT AND CONCLUSION: The optimum extraction conditions are pressure 21 MPa, temperature 37 degrees C and flow rate of CO2 5 L.min-1, according to the rate of extraction.


Asunto(s)
Ciclooctanos/aislamiento & purificación , Lignanos/aislamiento & purificación , Plantas Medicinales/química , Compuestos Policíclicos/aislamiento & purificación , Schisandra/química , Dióxido de Carbono , Cromatografía Líquida de Alta Presión/métodos , Cromatografía con Fluido Supercrítico/métodos , Frutas/química
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