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1.
Phys Rev Lett ; 125(19): 191801, 2020 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-33216576

RESUMEN

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (ν[over ¯]_{e}) disappearance taking place between six 2.8 GW_{th} reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ν[over ¯]_{e} oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on sin^{2}2θ_{14} in the 10^{-4}≲|Δm_{41}^{2}|≲0.5 eV^{2} region, free from reactor ν[over ¯]_{e} flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at |Δm_{41}^{2}|≲0.002 eV^{2} using the ν[over ¯]_{e} disappearance channel.

2.
Ann Oncol ; 30(5): 788-795, 2019 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-30785198

RESUMEN

BACKGROUND: Capecitabine plus oxaliplatin (XELOX) has shown modest activity and tolerable toxicity in a phase II trial for biliary tract cancers (BTCs). Meanwhile, gemcitabine plus oxaliplatin (GEMOX) has been the reference arm in recent phase II and III trials for BTCs. We aimed to investigate the efficacy of XELOX versus GEMOX as first-line therapy for advanced BCTs. PATIENTS AND METHODS: In this open-label, randomized, phase III, noninferiority trial, we randomly selected patients with metastatic BCTs to receive GEMOX (gemcitabine 1000 mg/m2 on days 1 and 8, and oxaliplatin 100 mg/m2 on day 1) or XELOX (capecitabine 1000 mg/m2, twice daily, on days 1-14 and oxaliplatin 130 mg/m2 on day 1) as first-line treatment, given every 3 weeks, totaling eight cycles. The primary end point was to prove the noninferiority of XELOX to GEMOX in terms of 6-month progression-free survival (PFS) rate. RESULTS: In total, 114 patients randomly received GEMOX and 108 randomly received XELOX. The median PFS was 5.3 months for the GEMOX group and 5.8 months for the XELOX group. The 6-month PFS rate was 44.5% for the GEMOX group and 46.7% for the XELOX group. The 95% confidence interval of the 6-month PFS rate difference between both groups was -12% to 16%, meeting the criteria for noninferiority of XELOX to GEMOX. There was no difference in objective response (P=0.171) and median overall survival (P=0.131) between both groups. The most common grade three to four adverse events were neutropenia and thrombocytopenia. No patient died of treatment-related causes. The XELOX group had significantly lower frequencies of hospital visits than the GEMOX group (P<0.001). CONCLUSION: XELOX showed significant noninferiority to GEMOX in terms of 6-month PFS rate. Thus, XELOX could be an alternative first-line treatment of BCTs. TRIAL REGISTRATION: This study was registered in ClinicalTrials.gov (number NCT01470443).


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Sistema Biliar/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias del Sistema Biliar/patología , Capecitabina/administración & dosificación , Capecitabina/efectos adversos , Desoxicitidina/administración & dosificación , Desoxicitidina/efectos adversos , Desoxicitidina/análogos & derivados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Oxaliplatino/administración & dosificación , Oxaliplatino/efectos adversos , Supervivencia sin Progresión , Tasa de Supervivencia , Gemcitabina
3.
Phys Rev Lett ; 122(23): 232501, 2019 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-31298906

RESUMEN

We report a fuel-dependent reactor electron antineutrino (ν[over ¯]_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ν[over ¯]_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43} cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43} cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43} cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.

4.
Phys Rev Lett ; 121(20): 201801, 2018 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-30500262

RESUMEN

The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (ν[over ¯]_{e}) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) ν[over ¯]_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the measured number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=[2.68±0.12(stat)±0.07(syst)]×10^{-3} eV^{2}.

5.
Phys Rev Lett ; 116(21): 211801, 2016 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-27284648

RESUMEN

The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3} eV^{2}.

6.
Phys Rev Lett ; 113(12): 121802, 2014 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-25279622

RESUMEN

We present the results of searches for nucleon decay via n→ν[over ¯]π0 and p→ν[over ¯]π+ using data from a combined 172.8 kt·yr exposure of Super-Kamiokande-I,-II, and-III. We set lower limits on the partial lifetime for each of these modes: τn→ν[over ¯]π0>1.1×10(33) years and τp→ν[over ¯]π+>3.9×10(32) years at a 90% confidence level.

7.
Int J Clin Pract ; 68(12): 1488-95, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25358955

RESUMEN

AIM: The peripheral artery questionnaire (PAQ) is a disease-specific health status measure of patients with peripheral artery disease (PAD). Whether the PAQ scores are associated with a PAD diagnosis among patients with symptoms suspicious for PAD is unknown and could help increase the pretest probability of ankle brachial index (ABI) screening among patients with suspicious symptoms. METHODS: The PAQ was completed by 567 patients evaluated for potential intermittent claudication at six tertiary centres. Demographics, medical history, physical examination findings and the PAQ domain scores were compared with ABI. A diagnostic threshold < 0.90 for a PAD diagnosis was assessed with a ROC of PAQ scores. The correlation between the PAQ Summary Score and ABI was also calculated. RESULTS: The PAQ Summary Score was significantly lower in patients with low ABI as compared with those having a normal ABI (37.6 ± 19.0 vs. 70.1 ± 22.7, p < 0.001). The PAQ Summary Score and ABI were highly correlated (r = 0.56, p < 0.001) and the optimal PAQ Summary Score for predicting low ABI was 50.3 (AUC = 0.86, sensitivity 80.3%, specificity 78.3%). CONCLUSIONS: The PAQ Summary Score was associated with an increased likelihood of PAD in patients with suspected PAD symptoms, and a low summary score (≤ 50.3) was an optimal threshold for predicting PAD among patients referred for ABI.


Asunto(s)
Índice Tobillo Braquial/estadística & datos numéricos , Extremidad Inferior/irrigación sanguínea , Tamizaje Masivo/métodos , Enfermedad Arterial Periférica/diagnóstico , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Claudicación Intermitente , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/complicaciones , Enfermedad Arterial Periférica/mortalidad , Sensibilidad y Especificidad , Encuestas y Cuestionarios
8.
Phys Rev Lett ; 110(18): 181802, 2013 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-23683190

RESUMEN

Super-Kamiokande atmospheric neutrino data were fit with an unbinned maximum likelihood method to search for the appearance of tau leptons resulting from the interactions of oscillation-generated tau neutrinos in the detector. Relative to the expectation of unity, the tau normalization is found to be 1.42 ± 0.35(stat)(-0.12)(+0.14)(syst) excluding the no-tau-appearance hypothesis, for which the normalization would be zero, at the 3.8σ level. We estimate that 180.1 ± 44.3(stat)(-15.2)(+17.8) (syst) tau leptons were produced in the 22.5 kton fiducial volume of the detector by tau neutrinos during the 2806 day running period. In future analyses, this large sample of selected tau events will allow the study of charged current tau neutrino interaction physics with oscillation produced tau neutrinos.

9.
Nutr Metab Cardiovasc Dis ; 23(7): 635-41, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22633791

RESUMEN

BACKGROUND AND AIM: Eating slowly is a crucial concept in behavioural nutrition and is recommended for weight management as it is believed to have an important effect on satiety control. This study aimed to determine whether or not eating rate is associated with cardiometabolic risk factors. METHODS AND RESULTS: This was a cross-sectional study involving 8775 Korean adults, who visited the Center for Health Promotion of Korea University Anam Hospital in Seoul, Korea. In male study participants, weight and body mass index (BMI) were found to depend on eating rate after adjusting for age, alcohol consumption, smoking, exercise and total energy intake. When adjusted for age, alcohol consumption, smoking, exercise and BMI, differences were found between the eating rate groups with respect to high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase (ALT) and alkaline phosphatase (ALP) values, white blood cell (WBC) count and total energy intake. Female participants were found to be different from males in that diastolic blood pressure and low-density lipoprotein (LDL)- and HDL-cholesterol values were significantly different between each eating rate group, while ALT and ALP values, WBC count and total energy intake were not. Compared with the slow eating rate group (>15 min), the fastest eating rate group (<5 min) had significantly increased odds ratios for cardiometabolic risk factors such as high glucose and low HDL-cholesterol levels in males, even after adjusting for BMI. CONCLUSION: Fast eating rates are associated with obesity and other cardiometabolic risk factors, particularly in men. Thus, eating slowly is recommended for weight reduction and to decrease cardiovascular risk factors.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Ingestión de Energía , Conducta Alimentaria , Hipercolesterolemia/etiología , Sobrepeso/etiología , Adulto , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etnología , HDL-Colesterol/sangre , Estudios Transversales , Ingestión de Energía/etnología , Conducta Alimentaria/etnología , Femenino , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/etnología , Hipercolesterolemia/fisiopatología , Masculino , Persona de Mediana Edad , Sobrepeso/sangre , Sobrepeso/etnología , Sobrepeso/fisiopatología , República de Corea/epidemiología , Factores de Riesgo , Caracteres Sexuales , Encuestas y Cuestionarios , Factores de Tiempo , Salud Urbana/etnología , Adulto Joven
10.
Chemosphere ; 318: 137973, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36709844

RESUMEN

The process of photoelectrochemical wastewater detoxification is limited by significant charge recombination, which is difficult to suppress with efficient single-material photoanodes. We demonstrated the effectiveness of hydrogen treatment in evaluating charge separation properties in WO3-x/TiO2-x NT/Ti foil heterojunction photoanodes. The influence of varying hydrogen annealing (200-400 °C) on the structural and photoelectrochemical properties of WO3/TiO2 NS/NT heterojunction is studied systematically. Additionally, after hydrogen treatment of pristine WO3/TiO2 NT/Ti foil photoanodes, substoichiometric H-WO3-x/TiO2-x NT-300 achieved the 1.21 mA/cm2 photocurrent density, which is 8.06 and 3.27 times than TiO2 NT and WO3/TiO2 NT. The hydrogen-treated H-WO3-x/TiO2-x NT-300 electrode exhibits 3 times greater bulk efficiencies than the WO3/TiO2 NT electrode due to the production of oxygen vacancies at the interface. Additionally, optimum H-WO3-x/TiO2-x NS/NT-300 photoanode exhibited 93.8% E. coli and 99.8% BPA decomposition efficiencies. The present work shows the effectiveness of microwave-assisted H-WO3-x/TiO2-x NT heterojunction photoanodes for organic decomposition and antibacterial activity in a neutral environment without surface-loaded co-catalysts.


Asunto(s)
Escherichia coli , Titanio , Aguas Residuales , Antibacterianos/farmacología , Hidrógeno
11.
Phys Rev Lett ; 108(19): 191802, 2012 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-23003027

RESUMEN

The RENO experiment has observed the disappearance of reactor electron antineutrinos, consistent with neutrino oscillations, with a significance of 4.9 standard deviations. Antineutrinos from six 2.8 GW(th) reactors at the Yonggwang Nuclear Power Plant in Korea, are detected by two identical detectors located at 294 and 1383 m, respectively, from the reactor array center. In the 229 d data-taking period between 11 August 2011 and 26 March 2012, the far (near) detector observed 17102 (154088) electron antineutrino candidate events with a background fraction of 5.5% (2.7%). The ratio of observed to expected numbers of antineutrinos in the far detector is 0.920±0.009(stat)±0.014(syst). From this deficit, we determine sin(2)2θ(13)=0.113±0.013(stat)±0.019(syst) based on a rate-only analysis.

12.
J Viral Hepat ; 18(10): e475-81, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21914066

RESUMEN

This study aimed to evaluate the long-term efficacy of entecavir (ETV) in adefovir (ADV)-refractory chronic hepatitis B (CHB) patients with prior lamivudine (LMV) resistance. A total of 55 ADV-refractory CHB patients with prior LMV resistance, who received rescue therapy with ETV 1 mg daily for at least 12 months, were consecutively enrolled and analysed. Forty-four patients were men, and their median age was 47 (25-69). Ten patients had liver cirrhosis and 46 patients were positive for hepatitis B e antigen (HBeAg). Median hepatitis B virus DNA levels were 6.6 (4.3-8.0) log(10) copies/mL, and the median duration of ETV therapy was 24 (12-47) months. Cumulative virologic response rates at 6, 12, 24 and 36 months were 18%, 29%, 58% and 75%, respectively. HBeAg loss occurred in 10 (21.7%) of 46 HBeAg-positive patients. In multivariate analysis, only initial virologic response at 3 months remained as an independent predictor for virologic response (RR 3.143; 95% CI 1.387-7.120; P = 0.006). The patients with a virological response at 3 months had not only a significantly higher probability of achieving a virologic response (P < 0.001) but also lower probability of experiencing a virologic breakthrough (P = 0.043) than the patients without an early response. Viral breakthrough was observed in 29 patients during the follow-up period. Cumulative breakthrough rates at 6, 12, 24 and 36 months were 0%, 15%, 45% and 73%, respectively. ETV monotherapy may be considerably efficacious in cases with an initial virological response but its efficacy is attenuated by frequent emergence of ETV resistance in ADV-refractory CHB patients with prior LMV resistance.


Asunto(s)
Adenina/análogos & derivados , Antivirales/administración & dosificación , Farmacorresistencia Viral , Guanina/análogos & derivados , Virus de la Hepatitis B/efectos de los fármacos , Hepatitis B Crónica/tratamiento farmacológico , Lamivudine/farmacología , Organofosfonatos/administración & dosificación , Adenina/administración & dosificación , Adulto , Anciano , ADN Viral/sangre , Femenino , Guanina/administración & dosificación , Antígenos de Superficie de la Hepatitis B/sangre , Humanos , Masculino , Persona de Mediana Edad , Terapia Recuperativa/métodos , Resultado del Tratamiento
13.
Mater Sci Eng C Mater Biol Appl ; 111: 110783, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32279749

RESUMEN

Mg-based bulk metallic glass (BMG) and its composites have been promising candidates for orthopedic fixation implants because of their biocompatibility, low degradation rate, and osteogenic potential. However, the amorphous state is affected by the cooling rate during the casting process. Solid, unstable structures combined with amorphous and crystalline structures are generated when an insufficient cooling rate is used. Here, we aimed to design and synthesize a novel core-shell structure comprising an amorphous shell and a crystalline core in order to overcome the material size limit imposed by the cooling rate effects. Our results show that the core-shell structure of Mg-based BMG does have a lower degradation rate and can maintain a more amorphous structure after six weeks of degradation. Moreover, the biocompatibility and osteogenic effects were similar between the core-shell and solid structures of Mg-based BMG. In conclusion, the core-shell structure of Mg-based BMG exhibits a lower degradation rate while still enhancing osteogenic potential in vitro. This core-shell structure of Mg-based BMG overcomes the cooling rate effects and provides a new structure for manufacturing Mg-based BMG.


Asunto(s)
Vidrio/química , Magnesio/química , Dispositivos de Fijación Ortopédica , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Fuerza Compresiva , Humanos , Osteogénesis/efectos de los fármacos , Transición de Fase , Propiedades de Superficie , Temperatura , Circonio/química
14.
Br J Anaesth ; 100(3): 380-4, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18238837

RESUMEN

BACKGROUND: N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methylisoxazolone-4-propionic acid (AMPA), and kainate (KA) receptors are members of the ionotropic glutamate receptor (iGluR) family and are increased in inflamed rat skin. These receptors contribute to inflammatory pain. In this study, we have examined whether there is a similar increase in iGluRs in inflamed human skin in the presence of inflammatory pain. METHODS: Normal and inflamed-skin biopsies were obtained from eight patients undergoing elective wound-debridement surgery. Real-time-polymerase chain reaction (PCR) and western blot analysis were used for quantitation of iGluR mRNA and protein in normal and inflamed human skin. RESULTS: A significant increase in mRNA and protein for NMDA, AMPA, and KA receptor subunits was detected in inflamed compared with normal skin. The amounts of NMDA (NR1 subunit), AMPA (GluR2 subunit), and KA (GluR6 subunit) mRNA in inflamed skin were mean 6 (SD 1.6-fold), 2.5 (0.6-fold), and 3.8 (0.9-fold) (P<0.05), respectively, greater than that measured in normal skin. The ratio of NR1, GluR2, and GluR6 protein in inflamed compared with normal skin was 5.7 (1.2), 2.4 (0.5), and 3.6 (0.9) (P<0.05), respectively. CONCLUSIONS: These results, in human tissue, demonstrate that iGluR mRNA and protein expression are increased during persistent inflammation and that this increased activity may be involved in mediating clinical inflammatory pain in human skin.


Asunto(s)
Dermatitis/metabolismo , Receptores de Glutamato/metabolismo , Piel/metabolismo , Adulto , Anciano , Western Blotting/métodos , Femenino , Humanos , Hiperalgesia/metabolismo , Masculino , Persona de Mediana Edad , Dimensión del Dolor/métodos , ARN Mensajero/genética , Receptores AMPA/genética , Receptores AMPA/metabolismo , Receptores de Glutamato/genética , Receptores de Ácido Kaínico/genética , Receptores de Ácido Kaínico/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Regulación hacia Arriba
15.
Eur J Surg Oncol ; 33(4): 444-7, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17174060

RESUMEN

AIM: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. Recently, many investigations have been conducted on various aspects of laparoscopic surgery for gastric GIST. However, no study has provided long-term follow up results of laparoscopic surgery for gastric GIST. The aims of this study were to assess the feasibility and safety of laparoscopic surgery for gastric GIST and to evaluate the oncologic validity of the procedure. MATERIALS AND METHODS: Between January 1998 and August 2005, 51 patients with submucosal tumor of the stomach were treated by laparoscopic surgery at our institution. Of 51 patients, 23 patients were confirmed as gastric GIST by immunohistochemistry (CD 117, c-kit gene product). Patients' clinicopathologic characteristics, operative outcomes, postoperative complications, and follow-up findings were analyzed retrospectively. RESULTS: The mean age of patients was 59.7 years, and 12 patients were women. Twelve patients (47%) presented with epigastric pain. The mean tumor size was 4.2+/-2.1 cm, and most tumors were located in the upper stomach (52.2%). The mean operative time was 104.3 min. No case of open conversion, reoperation and operative mortality occurred in the present study. Most patients had very low and low risk (60.6%), while only two patients had high risk malignancy. During a median follow-up period of 61 months (range, 7-98 months), there have been no recurrences or metastases. CONCLUSION: Laparoscopic wedge resection for gastric GIST is safe, and oncologically and technically feasible in the hands of an experienced laparoscopic gastric surgeon.


Asunto(s)
Tumores del Estroma Gastrointestinal/cirugía , Gastroscopía , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Tumores del Estroma Gastrointestinal/patología , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Retrospectivos , Resultado del Tratamiento
16.
Mater Sci Eng C Mater Biol Appl ; 75: 1-6, 2017 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-28415381

RESUMEN

Safety and reliability are crucial issues for medical instruments and implants. In the past few decays, bulk metallic glasses (BMGs) have drawn attentions due to their superior mechanical properties, good corrosion resistance, antibacterial and good biocompatibility. However, most Zr-based and Ti-based BMGs contain Ni as an important element which is prone to human allergy problem. In this study, the Ni-free Ti-based and Zr-based BMGs, Ti40Zr10Cu36Pd14, and Zr48Cu36Al8Ag8, were selected for systematical evaluation of their biocompatibility. Several biocompatibility tests, co-cultural with L929 murine fibroblast cell line, were carried out on these two BMGs, as well as the comparison samples of Ti6Al4V and pure Cu. The results in terms of cellular adhesion, cytotoxicity, and metallic ion release affection reveal that the Ti40Zr10Cu36Pd14 BMG and Ti6Al4V exhibit the optimum biocompatibility; cells still being attached on the petri dish with good adhesion and exhibiting the spindle shape after direct contact test. Furthermore, the Ti40Zr10Cu36Pd14 BMG showed very low Cu ion release level, in agreement with the MTT results. Based on the current findings, it is believed that Ni-free Ti-based BMG can act as an ideal candidate for medical implant.


Asunto(s)
Fibroblastos/metabolismo , Vidrio/química , Ensayo de Materiales , Titanio/química , Circonio/química , Animales , Adhesión Celular , Línea Celular , Fibroblastos/citología , Ratones , Níquel
17.
Mater Sci Eng C Mater Biol Appl ; 77: 308-317, 2017 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-28532034

RESUMEN

The Ti/Zr-based metallic glasses (MGs) with various Cu contents are prepared, with nominal compositions of Ti45Zr40Si15 (Cu-free), Ti45Zr40Si10Cu5 (low-Cu), and Ti45Zr20Cu35 (high-Cu). The mechanical properties, corrosion resistance, and in-vitro biocompatibility of these MGs are investigated by means of nano-indentation, electrochemical analyses, MTS assays and inductively coupled plasma mass spectrometry, as well as in-vivo biocompatibility in terms of scanning electron microscopy, micro-CT scans and histological observations. The results show that the electrochemical activity and biocompatibility of the MGs are sensitive to the Cu content. Following the electrocorrosion tests, an increase in ion concentration is observed in high-Cu MG. Eight independent in-vitro tests show that the higher ion concentration leads to a lower cell viability. The twelve-week in-vivo tests show that the Cu-free MGs can be a promising material for developing bio-implants. The high-Cu MG would release Ti and Zr ions with insignificant Cu ion following corrosion testing, enhancing an increased local osteoclast activity.


Asunto(s)
Vidrio , Materiales Biocompatibles , Supervivencia Celular , Corrosión , Humanos , Ensayo de Materiales , Titanio , Circonio
18.
Blood Cancer J ; 7(6): e581, 2017 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-28665416

RESUMEN

Extensive interindividual variation in response to chemotherapy is a major stumbling block in achieving desirable efficacy in the treatment of cancers, including multiple myeloma (MM). In this study, our goal was to develop a gene expression signature that predicts response specific to proteasome inhibitor (PI) treatment in MM. Using a well-characterized panel of human myeloma cell lines (HMCLs) representing the biological and genetic heterogeneity of MM, we created an in vitro chemosensitivity profile in response to treatment with the four PIs bortezomib, carfilzomib, ixazomib and oprozomib as single agents. Gene expression profiling was performed using next-generation high-throughput RNA-sequencing. Applying machine learning-based computational approaches including the supervised ensemble learning methods Random forest and Random survival forest, we identified a 42-gene expression signature that could not only distinguish good and poor PI response in the HMCL panel, but could also be successfully applied to four different clinical data sets on MM patients undergoing PI-based chemotherapy to distinguish between extraordinary (good and poor) outcomes. Our results demonstrate the use of in vitro modeling and machine learning-based approaches to establish predictive biomarkers of response and resistance to drugs that may serve to better direct myeloma patient treatment options.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Expresión Génica/genética , Mieloma Múltiple/tratamiento farmacológico , Inhibidores de Proteasoma/uso terapéutico , Humanos , Mieloma Múltiple/patología
19.
Mater Sci Eng C Mater Biol Appl ; 62: 368-76, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26952435

RESUMEN

Systematic characterization of the corrosion response of the Cu-free Ti45Zr40Si15 and Cu-containing Ti40Zr40Si15-Cu5 and Ti45Zr20-Cu35 metallic glasses (MGs) in the Hank's solution is conducted, in terms of the open circuit potential, potentiodynamic polarization, as well as electrochemical impedance measurements. The Cu role in the Ti-based MGs, tentatively to be applied for bio-implants, is established and modeled. The presence of nobler Cu will impose two opposite effects. The minor positive effect of minor shift of Ecorr is not a major issue, but the negative effect on local pitting and ion release would cause a major drawback. The ICP-MS indicates that the release of Cu ions increases with increasing Cu content. For more promising anti-pitting ability, the Cu content in Ti-based MGs should be kept as low as possible, better to be none or less than about 5 at.%.


Asunto(s)
Líquidos Corporales/química , Cobre/química , Vidrio/química , Titanio/química , Circonio/química , Humanos
20.
Leukemia ; 30(5): 1094-102, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26710886

RESUMEN

Multiple myeloma (MM) is characterized by significant genetic diversity at subclonal levels that have a defining role in the heterogeneity of tumor progression, clinical aggressiveness and drug sensitivity. Although genome profiling studies have demonstrated heterogeneity in subclonal architecture that may ultimately lead to relapse, a gene expression-based prediction program that can identify, distinguish and quantify drug response in sub-populations within a bulk population of myeloma cells is lacking. In this study, we performed targeted transcriptome analysis on 528 pre-treatment single cells from 11 myeloma cell lines and 418 single cells from 8 drug-naïve MM patients, followed by intensive bioinformatics and statistical analysis for prediction of proteasome inhibitor sensitivity in individual cells. Using our previously reported drug response gene expression profile signature at the single-cell level, we developed an R Statistical analysis package available at https://github.com/bvnlabSCATTome, SCATTome (single-cell analysis of targeted transcriptome), that restructures the data obtained from Fluidigm single-cell quantitative real-time-PCR analysis run, filters missing data, performs scaling of filtered data, builds classification models and predicts drug response of individual cells based on targeted transcriptome using an assortment of machine learning methods. Application of SCATT should contribute to clinically relevant analysis of intratumor heterogeneity, and better inform drug choices based on subclonal cellular responses.


Asunto(s)
Mieloma Múltiple/genética , Análisis de la Célula Individual/métodos , Transcriptoma/genética , Algoritmos , Línea Celular Tumoral , Biología Computacional , Variación Genética , Humanos , Aprendizaje Automático , Mieloma Múltiple/tratamiento farmacológico , Inhibidores de Proteasoma/farmacología , Estadística como Asunto
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