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1.
Zhonghua Fu Chan Ke Za Zhi ; 56(5): 341-348, 2021 May 25.
Artículo en Zh | MEDLINE | ID: mdl-34034421

RESUMEN

Objective: To investigate the occurrence and influencing factors of perioperative complications after robotic gynecologic surgery. Methods: The clinical data and occurrence of perioperative complications in 1 000 cases robotic surgery completed in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. Results: (1) Clinical data: the average age of the patients was (50.2±10.4) years old, and the average body mass index (BMI) was (24.4±3.6) kg/m2. Among 1 000 cases, 811 cases of them were malignant tumors, including 405 cases of cervical cancer, 279 cases of endometrial carcinoma, 112 cases of epithelial ovarian cancer (EOC), 15 cases of vulvar cancer; 189 cases of them were benign diseases, including 43 cases of uterine prolapse, 57 cases hysterectomy of uterine leiomyoma and adenomyosis of the uterus ≥12 weeks, 84 cases myomectomy of uterine leiomyoma, and 5 cases of fallopian tubal ligation requiring anastomosis. Surgical methods: in patients with malignant tumors, cervical cancer, hysterectomy plus salpingectomy or salpingo-oophorectomy for stage Ⅰa1, and radical hysterectomy plus pelvic lymphatic dissection plus salpingectomy or salpingo-oophorectomy for stage Ⅰa2-Ⅱb. Endometrial carcinoma, performed by staging surgery. Staging surgery for EOC with early stage and cytoreductive surgery with advanced EOC. Vulvar cancer, extensive vulvar resection plus inguinal lymphadenectomy. In patients with benign diseases, uterine prolapse, hysterectomy plus salpingectomy or salpingo-oophorectomy plus sacrocolpopexy. Uterine leiomyoma or adenomyosis with uterus ≥ 12 weeks, hysterectomy plus salpingectomy or salpingo-oophorectomy. Myomectomy for patients requiring uterine preservation with uterine leiomyoma. Tubal anastomosis for patients with fallopian tubal ligation. (2) Surgical complications: intraoperative complications occurred in 25 patients (2.5%, 25/1 000), including 11 patients with vascular laceration, 11 patients with ureteral injury, 2 patients with bladder injury, and 1 patient with intestinal injury. Postoperative complications occurred in 130 patients (13.0%, 130/1 000), including 66 cases of lower limb venous thrombosis, 20 cases of lymphatic cyst, 8 cases of hydronephrosis, 9 cases of ileus, 16 cases with infection, 6 cases with genital fistula, 4 cases with trocar site herniation and 1 case with subcutaneous emphysema. The incidence of intraoperative complications was 3.1% (25/811) in malignant tumors and no case in benign diseases, the incidence rate in malignant tumors was significantly higher than that in benign diseases (χ²=4.778, P=0.029). The incidence rate in cervical cancer (4.2%, 17/405) and EOC (3.6%, 4/112) were significantly higher than those in endometrial carcinoma (1.4%, 4/279) and vulvar cancer (0/15; P<0.05). The incidence of postoperative complications was 15.2% (123/811) in malignant tumors and 3.7% (7/189) in benign diseases. The incidence rate in malignant tumors was significantly higher than that in benign diseases (χ²=17.807, P<0.01), but there were no significant difference among different malignant tumors (χ²=4.318, P=0.229). (3) The correlative factors affecting the occurrence of surgical complications: patient's age, BMI, previous pelvic or abdominal surgery history, the nature of disease (malignant or benign), operation time, and comorbidities had a significant impact on the incidence of postoperative complications (P<0.05). Multivariate logistic regression analysis showed that the patient's age ≥40 years old, BMI ≥25 kg/m2, previous pelvic or abdominal surgery history, malignant tumors and comorbidities were independent influential factors of the postoperative complications (P<0.05). Conclusions: Perioperative complications vary according to the type of the surgery. The age, BMI, previous pelvic or abdominal surgery history, malignant tumors, and comorbidities are influential factors of postoperative complications.


Asunto(s)
Laparoscopía , Procedimientos Quirúrgicos Robotizados , Adulto , Femenino , Procedimientos Quirúrgicos Ginecológicos/efectos adversos , Humanos , Histerectomía/efectos adversos , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Procedimientos Quirúrgicos Robotizados/efectos adversos
2.
Phys Rev Lett ; 121(24): 241805, 2018 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-30608728

RESUMEN

We report a measurement of electron antineutrino oscillation from the Daya Bay Reactor Neutrino Experiment with nearly 4 million reactor ν[over ¯]_{e} inverse ß decay candidates observed over 1958 days of data collection. The installation of a flash analog-to-digital converter readout system and a special calibration campaign using different source enclosures reduce uncertainties in the absolute energy calibration to less than 0.5% for visible energies larger than 2 MeV. The uncertainty in the cosmogenic ^{9}Li and ^{8}He background is reduced from 45% to 30% in the near detectors. A detailed investigation of the spent nuclear fuel history improves its uncertainty from 100% to 30%. Analysis of the relative ν[over ¯]_{e} rates and energy spectra among detectors yields sin^{2}2θ_{13}=0.0856±0.0029 and Δm_{32}^{2}=(2.471_{-0.070}^{+0.068})×10^{-3} eV^{2} assuming the normal hierarchy, and Δm_{32}^{2}=-(2.575_{-0.070}^{+0.068})×10^{-3} eV^{2} assuming the inverted hierarchy.

3.
Br J Cancer ; 117(4): 525-534, 2017 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-28632723

RESUMEN

BACKGROUND: MiR-646 has been reported to be aberrantly expressed in human cancers. However, the underlying molecular mechanisms of action of miR-646 in gastric cancer (GC) have not yet been investigated. METHODS: In vitro function of miR-646 in GC was evaluated using EdU assay, plate colony formation assay, and matrigel invasion assay. Real-time PCR or western blotting was performed to detect miR-646 and FOXK1 expressions. In vivo tumour growth and metastasis were conducted in nude mice. RESULTS: MiR-646 expression was downregulated in GC tissues compared with adjacent normal tissues. Low miR-646 expression is associated with malignant progression. Transient transfection of GC cells with miR-646 inhibited their growth and migration. Moreover, miR-646 influenced the expression of epithelial-mesenchymal transition (EMT)-associated proteins. TGF-ß1 treatment significantly suppressed the expression of miR-646 and overexpression of this microRNA counteracted the influence of the TGF-ß1-induced EMT phenotype. In terms of the underlying mechanism, miR-646 directly targeted FOXK1. In vivo, it inhibited the FOXK1-mediated proliferation and EMT-induced metastasis. Consistently, inverse correlations were also observed between the expression of miR-646 and FOXK1 in human GC tissue samples. Furthermore, miR-646 regulated Akt/mTOR signalling after FOXK1. CONCLUSIONS: miR-646 inhibited GC cell proliferation and the EMT progression in GC cells by targeting FOXK1.


Asunto(s)
Transición Epitelial-Mesenquimal , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias Gástricas/metabolismo , Animales , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Regulación hacia Abajo , Transición Epitelial-Mesenquimal/efectos de los fármacos , Femenino , Humanos , Metástasis Linfática , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , MicroARNs/antagonistas & inhibidores , MicroARNs/farmacología , Invasividad Neoplásica , Estadificación de Neoplasias , Trasplante de Neoplasias , Fenotipo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Serina-Treonina Quinasas TOR/metabolismo , Factor de Crecimiento Transformador beta1/farmacología , Carga Tumoral , Ensayo de Tumor de Célula Madre
4.
Phys Rev Lett ; 118(25): 251801, 2017 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-28696753

RESUMEN

The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43} cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43} cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43} cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

5.
Genet Mol Res ; 14(3): 10692-704, 2015 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-26400299

RESUMEN

Argopecten purpuratus and Argopecten irradians irradians hybridization was successfully performed and the hybrid offspring displayed apparent heterosis in growth traits. To better understand the genetic basis of heterosis, the genomic composition and genetic variation of the hybrids were analyzed with amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Seven of eight universal SSR primers displayed polymorphism in the hybrids and their parental groups, and hybrids inherited both parental geno-types at each locus. Using five primer combinations in AFLP analysis, 433 loci were amplified in the hybrids and their parental groups. The frequency of polymorphisms was 88.22%. F1 hybrids inherited 88.11 and 92.88% of AFLP bands from their parents. Some loci did not follow Mendelian Law, including 48 loci in parents that were lost, and 11 new loci that were amplified in the hybrids. The parameters of Nei's gene diversity, Shannon's Information index, genetic distance, and molecular variance between groups were calculated. The genetic differentiation between two hybrid groups (0.253) was smaller than that between hybrids and their parents (0.554 to 0.645), and was especially smaller than that between two parental groups (0.769). The high genetic similarity (0.9347) and low genetic differentiation (0.2531) between two hybrid groups suggests that these hybrid groups were genetically very close. Heterozygosities of hybrid groups were higher than those of parental groups, indicating that the hybrids had increased genetic diversity.


Asunto(s)
Sitios Genéticos , Genoma , Vigor Híbrido , Hibridación Genética , Pectinidae/genética , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Animales , Cruzamientos Genéticos , Cartilla de ADN , Femenino , Marcadores Genéticos , Heterocigoto , Patrón de Herencia , Masculino , Repeticiones de Microsatélite , Pectinidae/clasificación , Filogenia , Polimorfismo Genético
6.
Folia Biol (Praha) ; 59(3): 105-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23890477

RESUMEN

Serine 7 of centromere protein A (CENP-A) is a very important mitosis-specific phosphorylation site. In this study, we demonstrate the subcellular distribution of Ser7 phosphorylated CENP-A during mitosis in MCF-7 cells. The Ser7 phosphorylation of CENP-A was observed beginning at prophase at centromeres. Upon progression of mitosis, the fluorescence signals emerged in the central region of the metaphase plate and were maintained until anaphase at centromeres. At late anaphase, the fluorescence signals moved to the midzone gradually and transferred from the centromere to the midbody completely at telophase. They were compacted into the centre of the midbody in a thin cylinder consisting of a sandglass-like "mitotic machine" with microtubules and condensed chromosome. We also found that Ser10 phosphorylated H3 and Thr11 phosphorylated H3 were co-localized at the midbody in two bell-like symmetrical bodies with Ser7 phosphorylated CENP-A during the terminal stage of cytokinesis. Midbody isolation and immunoblotting experiments also indicated that Ser7 phosphorylated CENP-A are components of the midbody. These findings suggest that Ser7 phosphorylated CENP-A acts as a chromosomal passenger protein and may play an important role in cytokinesis.


Asunto(s)
Autoantígenos/fisiología , Centrómero/metabolismo , Proteínas Cromosómicas no Histona/fisiología , Células MCF-7/metabolismo , Mitosis/fisiología , Proteínas de Neoplasias/fisiología , Huso Acromático/metabolismo , Adenocarcinoma/patología , Autoantígenos/química , Transporte Biológico , Neoplasias de la Mama/patología , Proteína A Centromérica , Proteínas Cromosómicas no Histona/química , Citocinesis/fisiología , Femenino , Histonas/metabolismo , Humanos , Células MCF-7/citología , Microscopía Confocal , Microscopía Fluorescente , Proteínas de Neoplasias/química , Fosforilación , Fosfoserina/metabolismo , Fosfotreonina/metabolismo , Embarazo , Procesamiento Proteico-Postraduccional , Huso Acromático/ultraestructura
7.
Conscious Cogn ; 21(4): 1662-72, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23073147

RESUMEN

This study investigated the differences between past and future temporal discounting in terms of neural activity in relation to temporal distance. Results show that brain regions are engaged differently in past and future temporal discounting. This is likely because past temporal discounting requires memory reconstruction, whereas future temporal discounting requires the processing of uncertainty about the future. In past temporal discounting, neural activity differed only when preferences were made between rewards received one hour prior and rewards received further in the past. The peak amplitudes of P2 and P3 varied as the temporal distance increased from 2 weeks to 50 years. In future temporal discounting, neural activity differed only when preferences were evaluated between two delayed rewards. The delay conditions (6 months:5 years) and (6 months:50 years) had a significant influence on P2 and N2. Findings indicate the existence of different decision-making systems operating in past and future temporal discounting.


Asunto(s)
Encéfalo/fisiología , Toma de Decisiones/fisiología , Potenciales Evocados/fisiología , Recompensa , Mapeo Encefálico , Electroencefalografía , Potenciales Relacionados con Evento P300/fisiología , Femenino , Humanos , Masculino , Factores de Tiempo , Incertidumbre , Adulto Joven
8.
Eur Rev Med Pharmacol Sci ; 24(12): 6674-6681, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32633357

RESUMEN

OBJECTIVE: To explore the biological functions of circ_0032627 in the progression of gastric cancer (GC). MATERIALS AND METHODS: The expression level of circ_0032627 in GC cell lines and gastric mucosal cell lines was measured via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Methyl thiazolyl tetrazolium (MTT) assay, colony formation assay, and FACS were performed to examine the influences of circ_0032627 on the proliferation and apoptosis of GC cells. The relationship between circ_0032627 and micro ribonucleic acids (miRNAs) was predicted on-line using StarBase software, and whether circ_0032627 can act as the sponge of the selected miRNAs was verified via Dual-Luciferase reporter assay and qRT-PCR. Finally, MTT assay was conducted to detect the influences of the co-knockdown of circ_0032627 and the selected miRNAs on the proliferation of GC cells. RESULTS: Compared with that in gastric mucosal cell lines, the expression level of circ_0032627 was upregulated in the selected four GC cell lines, and circ_0032627 knockdown substantially inhibited the proliferation of GC cells, but promoted their apoptosis. Circ_0032627 could act as a sponge of miR-502-5p, and miR-502-3p knockdown reversed the inhibitory effect of circ_0032627 on the proliferation of GC cells. CONCLUSIONS: The expression level of circ_0032627 is raised in GC cells, and circ_0032627 affects the proliferation and apoptosis of GC cells by sponging miR-502-5p.


Asunto(s)
Proliferación Celular/fisiología , Regulación Neoplásica de la Expresión Génica , MicroARNs/biosíntesis , ARN Circular/biosíntesis , Neoplasias Gástricas/metabolismo , Línea Celular Tumoral , Humanos , MicroARNs/genética , ARN Circular/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología
9.
Artículo en Zh | MEDLINE | ID: mdl-28219168

RESUMEN

Objective: To explore the clinical characteristics of case of thyroid adenoma in the piriform fossa, and review the literatures of the congentital thyroid gland abnormality. Methods: A 44-year-old male had foreign body feeling in his pharynx for 3 years. A mass in his left piriform fossa was detected by the clinical and imaging examination. Biopsy report that the mass was thyroid papillary carcinoma. The resection of tumor with partial back thyroid cartilage through lateral neck and pharyngeal approach was performed. Results: The surgical wound healed in first-stage and no any surgical complication occurred. With postoperative pathological and immunohistochemical examination, the mass was finally diagnosed as thyroid gland adenoma. Staining for cytokerantin19 was negative. Conclusion: The symptomatic and neoplastic abnormal thyroid gland should be excised, but asymptomtic, non-neoplastic and functional abnormal thyroid gland should be retained with regular follow up.


Asunto(s)
Adenoma/patología , Seno Piriforme , Neoplasias de la Tiroides/patología , Adenoma/cirugía , Adulto , Carcinoma/patología , Carcinoma Papilar , Diagnóstico Diferencial , Humanos , Masculino , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/cirugía
10.
Folia Biol (Praha) ; 52(5): 156-60, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17116287

RESUMEN

The phosphorylation of histone H3 at Ser10, Ser28, Thr11 and Thr3 of the amino terminal has been proved related to mitosis of the mammalian cells. However, the function of the Thr3 phosphorylation of H3 remains unclear. In this study, indirect immunofluorescence labelling and laser confocal microscopy were used to examine the cellular dynamic distribution of Thr3-phosphorylated H3 at mitosis in CHO cells. The results showed that the Thr3 phosphorylation began at early prophase and spread throughout the chromosomes at late prophase. At metaphase, most of the Thr3-phosphorylated H3 was distributed along the entire chromosomal arms and maintained until early anaphase. During late anaphase and telophase, the fluorescent signal of Thr3-phosphorylated H3 disappeared from chromosomes. There was a precise spatial and temporal correlation between H3 phosphorylation of Thr3 and stages of chromatin condensation. The timing of Thr3 phosphorylation and dephosphorylation in mitosis were similar to that reported for Thr11 phosphorylation of H3. The Thr3-phosphorylated H3 localized along the arms of chromosomes during metaphase and early anaphase. It was different from the Ser10-phosphorylated H3, which localized at telomere regions, and Thr11-phosphorylated H3, which localized at centromeres. The results suggest that the Thr3 phosphorylation of histone H3 may play a specific role, which is different from Ser10 phosphorylation and Thr11 phosphorylation in mitosis.


Asunto(s)
Histonas/metabolismo , Mitosis , Animales , Células CHO , Cricetinae , Cricetulus , Técnica del Anticuerpo Fluorescente , Microscopía Confocal , Fosforilación , Treonina/metabolismo
11.
J Mol Biol ; 216(2): 195-9, 1990 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-2174973

RESUMEN

An unusual structural component, supercondensed pBR322 DNA, has been found in plasmid pBR322 DNA samples isolated from a DNA topoisomerase II mutant of Escherichia coli, SD108 (topA+, gyrB225). The supercondensed pBR322 DNA moved faster than supercoiled pBR322 DNA as a homogeneous band in agrose gels when the DNA samples were analysed by electrophoresis. The mobility of the supercondensed DNA was not substantially affected by chloroquine intercalation. The supercondensed pBR322 DNA migrated as a high density "third DNA band" when the samples were subjected to caesium chloride/ethidium bromide gradient equilibrium centrifugation. The unusual pBR322 DNA visualized by electron microscopy was a globoid-shaped particle. These observations suggest that the pBR322 plasmid can assume a tertiary structure other than a supercoiled or relaxed structure. DNA topoisomerases may be involved in the supercondensation of plasmid DNA and chromosomal DNA.


Asunto(s)
ADN-Topoisomerasas de Tipo II/genética , ADN Bacteriano/genética , Escherichia coli/genética , Mutación , Plásmidos , ADN Bacteriano/aislamiento & purificación , ADN Bacteriano/ultraestructura , Electroforesis en Gel de Agar , Escherichia coli/enzimología , Microscopía Electrónica
12.
Neuroscience ; 290: 389-97, 2015 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-25637487

RESUMEN

Working memory (WM) is a core element of temporal information processing, but little is known about the internal representation and neuronal underpinnings of the duration maintenance in WM. The neural oscillations during maintenance of duration in WM were examined using electroencephalogram (EEG) recordings. The EEG results showed that theta amplitude was not modulated by the length of duration retained in WM, while alpha amplitude decreased in a 4-s duration condition compared with 1-s, 2-s, and 3-s duration conditions. The amplitude of alpha power positively correlated with accuracy for the 3-s duration condition. The results suggest that alpha activity is involved in duration maintenance in WM. Our study provides electrophysiological evidence that different internal representations are retained in WM for durations below and above about 3s.


Asunto(s)
Ritmo alfa/fisiología , Encéfalo/fisiología , Memoria a Corto Plazo/fisiología , Ritmo Teta/fisiología , Electroencefalografía , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Estimulación Luminosa , Factores de Tiempo , Percepción Visual/fisiología , Adulto Joven
13.
Indian J Med Microbiol ; 33(3): 413-5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26068346

RESUMEN

In recent years, Candida infections have been increasing significantly. This study was to investigate the distribution and fluconazole susceptibility of such infections. Totally, 3,056 clinical isolates were analysed, C. albicans was the most prevalent species from respiratory and vaginal specimens. However, non-albicans species constituted the majority of isolates from blood, urine, intensive care unit (ICU), organ transplant and burned patients. Similarly, Candida spp. from different specimens and clinical services had different degrees of susceptibility to fluconazole. Isolates from vagina and burned patients had the highest resistance rate, while all of the isolates from ascites and dermatological services were susceptible to fluconazole.


Asunto(s)
Antifúngicos/farmacología , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Candidiasis/microbiología , Farmacorresistencia Fúngica , Fluconazol/farmacología , Candidiasis/epidemiología , Humanos , Pruebas de Sensibilidad Microbiana , Prevalencia , Centros de Atención Terciaria
14.
J Nanosci Nanotechnol ; 4(8): 1071-5, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15656205

RESUMEN

Comparative study on the diameter distribution of MgO nanowires has been carried out. MgO nanowires could be synthesized by the direct reaction between metallic magnesium and silica, and the obtained nanowires have diameters ranging from 50 to 200 nm and lengths of several hundreds nanometers, exhibiting a straight wire. The diameter can be downscaled to smaller than 50 nm, and the nanowire exhibits a curved and twisted one-dimensional structure with lengths up to several micrometers, when a fine support catalyst was used as the reactant. The diameter-controlled growth mechanism was also explained in this work.


Asunto(s)
Cristalización/métodos , Óxido de Magnesio/química , Magnesio/química , Nanotecnología/métodos , Nanotubos/química , Nanotubos/ultraestructura , Dióxido de Silicio/química , Ensayo de Materiales , Conformación Molecular , Nanotubos/análisis , Tamaño de la Partícula , Propiedades de Superficie
15.
Yao Xue Xue Bao ; 25(9): 641-5, 1990.
Artículo en Zh | MEDLINE | ID: mdl-1965481

RESUMEN

DNA topoisomerase I has been isolated from the nuclei of calf thymus by PEG fractionation and chromatography on P11 and on Bio-Rex 70. Either a positive or negative supercoiled pBR322 DNA can be relaxed by the enzyme. The activity of Topo I is Mg2+ and ATP independent. Some of nonintercalative antitumor drugs such as camptothecine, hydroxycamptothecine, cyclophosphamide, methotrexate and mitomycin C were found to inhibit the activity of Topo I. The results suggest that DNA Topo I can be used to screen new nonintercalative antitumor drugs as a target protein.


Asunto(s)
Antineoplásicos/farmacología , ADN-Topoisomerasas de Tipo I/metabolismo , Animales , Bovinos , Ciclofosfamida/farmacología , ADN-Topoisomerasas de Tipo I/efectos de los fármacos , ADN-Topoisomerasas de Tipo I/aislamiento & purificación , Metotrexato/farmacología , Mitomicina , Mitomicinas/farmacología , Timo/enzimología
18.
Phys Rev Lett ; 101(10): 102004, 2008 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-18851209

RESUMEN

We observe an obvious anomalous line shape of the e;{+}e;{-}--> hadrons total cross sections in the energy region between 3.700 and 3.872 GeV. It is inconsistent with the explanation for only one simple psi(3770) resonance with a statistical significance of 7sigma. The anomalous line shape may be explained by two possible enhancements of the inclusive hadron production near the center-of-mass energies of 3.764 and 3.779 GeV, indicating that either there is likely a new structure in addition to the psi(3770) resonance around 3.773 GeV, or there are some physics effects reflecting the DD[over ] production dynamics.

19.
Phys Rev Lett ; 100(10): 102003, 2008 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-18352176

RESUMEN

The decays of J/psi --> etaphif(0)(980)[eta --> gammagamma, phi --> K(+) K(-), f(0)(980) --> pi(+)pi(-)] are analyzed using a sample of 5.8 x 10(7) J/psi events collected with the BESII detector at the Beijing Electron-Positron Collider. A structure at around 2.18 GeV/c(2) with about 5 sigma significance is observed in the phif(0)(980) invariant mass spectrum. A fit with a Breit-Wigner function gives the peak mass and width of m = 2.186+/-0.010(stat)+/-0.006(syst) GeV/c(2) and Gamma = 0.065+/-0.023(stat)+/-0.017(syst) GeV/c(2), respectively, which are consistent with those of Y(2175), observed by the BABAR Collaboration in the initial-state radiation process e(+)e(-) --> gamma(ISR) phif(0)(980). The production branching ratio is determined to be Br(J/psi --> etaY(2175))Br(Y(2175)- -> phif(0)(980))Br(f(0)(980) --> pi(+)pi(-)) = [3.23+/-0.75(stat)+/-0.73(syst)] x 10(-4), assuming that the Y(2175) is a 1(--) state.

20.
Phys Rev Lett ; 100(19): 192001, 2008 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-18518438

RESUMEN

Using psi(2S) --> pi(+)pi(-) J/psi events in a sample of 14.0 x 10(6) psi(2S) decays collected with the BES-II detector, a search for the decay of the J/psi to invisible final states is performed. No signal is found, and an upper limit at the 90% confidence level is determined to be 1.2 x 10(-2) for the ratio B(J/psi --> invisible)/B(J/psi-->mu(+)mu(-)). This is the first search for J/psi decays to invisible final states.

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