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1.
Inorg Chem ; 62(31): 12573-12581, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37498117

RESUMEN

In the present study, we fabricated hollow cubic CuxO nanoparticles (∼23 nm) incorporated with CNF (HC-CuxO/CNF) through controlled thermal oxidation of solid cubic Cu2O nanoparticles (∼21 nm) supported on carbon nanofibers (SC-Cu2O/CNF) under airflow, exploiting the nanoscale Kirkendall effect. These hollow CuxO nanocubes with increased surface areas exhibited outstanding catalytic activity for unsymmetrical chalcogenide synthesis under ligand-free conditions.

3.
Oncologist ; 23(10): 1230-1235, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29895629

RESUMEN

BACKGROUND: There is significant variation in access to palliative care. We examined the pattern of outpatient palliative care referral among thoracic medical oncologists and identified oncologist characteristics associated with greater referral. MATERIALS AND METHODS: We retrieved data on all patients who died of advanced thoracic malignancies at our institution between January 1, 2007, and December 31, 2012. Using median as a cutoff, we defined two groups (high-referring and low-referring oncologists) based on their frequency of referral. We examined various oncologist- and patient-related characteristics associated with outpatient referral. RESULTS: Of 1,642 decedents, 444 (27%) had an outpatient palliative care referral. The median proportion of referral among 26 thoracic oncologists was 30% (range 9%-45%; median proportion of high-referring 37% vs. low-referring 24% when divided into two groups at median). High-referring oncologists were significantly younger (age 45 vs. 56) than low-referring oncologists; they were also significantly more likely to refer patients earlier (median interval between oncology consultation and palliative care consultation 90 days vs. 170 days) and to refer those without metastatic disease (7% vs. 2%). In multivariable mixed-effect logistic regression, younger oncologists (odds ratio [OR] = 0.97 per year increase, 95% confidence interval [CI] 0.95-0.995), younger patients (OR = 0.98 per year increase, 95% CI 0.97-0.99), and nonmetastatic disease status (OR = 0.48, 95% CI 0.29-0.78) were significantly associated with outpatient palliative care referral. CONCLUSION: The pattern of referral to outpatient palliative care varied widely among thoracic oncologists. Younger oncologists were not only referring a higher proportion of patients, but also referring patients earlier in the disease trajectory. IMPLICATIONS FOR PRACTICE: This retrospective cohort study found that younger thoracic medical oncologists were significantly more likely to refer patients to outpatient palliative care and to do so earlier in the disease trajectory compared with older oncologists, even after adjusting for other known predictors such as patient demographics. The findings highlight the role of education to standardize palliative care access and imply that outpatient palliative care referral is likely to continue to increase with a shifting oncology workforce.


Asunto(s)
Oncólogos/normas , Cuidados Paliativos/métodos , Pautas de la Práctica en Medicina/normas , Neoplasias Torácicas/terapia , Atención Ambulatoria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Derivación y Consulta
4.
Qual Life Res ; 27(6): 1571-1581, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29478132

RESUMEN

PURPOSE: The objective of this study was to investigate the impact of caregivers' role preference in decision making on conflicts and psychiatric distresses. METHODS: The responses of 406 caregivers of terminal cancer patients enrolled in a trial determining the efficacy of a decision aid focused on the disclosure of terminal disease status were included in this secondary analysis. The outcomes include the change scores of the Decision Conflict Scale (DCS) and depression and anxiety subscales of the Hospital Anxiety and Depression Scale (HADS) at the 1 and 3 months from baseline. The linear mixed model was employed to discover the impact of caregivers' decisional role preference on the outcomes. FINDINGS: Of the 406, 137 (33.7%) showed an active role preference and 269 (66.3%) showed a passive role preference. In the post hoc analysis of the adjusted differences of change scores between passive caregivers who received decision aid (passive-decision aid) and active caregivers with decision aid (active-decision aid), non-significant differences were observed in the DCS. However, at the 3-month, the change scores of the HADS depression subscale increased by 4.43 (effect size, 0.71) and those of the HADS anxiety subscale increased by 4.14 (effect size, 0.61) in the passive-decision aid group than in active-decision aid group, showing moderate to large difference. CONCLUSIONS: These findings suggest that information might be ethically recommended in a format that is interactive and tailored to how much an individual wishes to be involved in the decision-making process.


Asunto(s)
Cuidadores/psicología , Toma de Decisiones/ética , Técnicas de Apoyo para la Decisión , Revelación/tendencias , Calidad de Vida/psicología , Cuidado Terminal/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad
5.
J Nanosci Nanotechnol ; 18(2): 1356-1360, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29448591

RESUMEN

Hollow nanomaterials have attracted great interest because of their many applications in catalysis, nanoreactors, drug delivery systems, for lubrication and in gas sensors. Here, carbon sphere templates were prepared from glucose under hydrothermal conditions to facilitate the synthesis of hollow Fe2O3 nanospheres. Thermal decomposition of an iron precursor in benzylalcohol with the carbon spheres resulted in the deposition of Fe3O4 nanoparticles on the carbon sphere templates. The nanoparticles on the carbon surface naturally agglomerate and form a dense oxide shell during the calcination step, which produces typical Fe2O3 hollow structures. The gas sensing performance of the hollow Fe2O3 nanospheres was investigated at an operating temperature of 300 °C. The hollow Fe2O3 nanospheres showed high sensitivity (R = 10.766 at 1 ppm formaldehyde) with a linear response to formaldehyde gas concentration in the range of 0.8~2.4 ppm, and good selectivity to formaldehyde gas in volatile organic compounds, compared to commercial Fe2O3 nanoparticles.

6.
Palliat Support Care ; 15(1): 110-124, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27021206

RESUMEN

OBJECTIVE: Caregivers of cancer patients face intense demands throughout the course of the disease, survivorship, and bereavement. Caregiver burden, needs, satisfaction, quality of life, and other significant areas of caregiving are not monitored regularly in the clinic setting, resulting in a need to address the availability and clinical effectiveness of cancer caregiver distress tools. This review aimed to determine the availability of cancer caregiver instruments, the variation of instruments between different domains of distress, and that between adult and pediatric cancer patient populations. METHOD: A literature search was conducted using various databases from 1937 to 2013. Original articles on instruments were extracted separately if not included in the original literature search. The instruments were divided into different areas of caregiver distress and into adult versus pediatric populations. Psychometric data were also evaluated. RESULTS: A total of 5,541 articles were reviewed, and 135 articles (2.4%) were accepted based on our inclusion criteria. Some 59 instruments were identified, which fell into the following categories: burden (n = 26, 44%); satisfaction with healthcare delivery (n = 5, 8.5%); needs (n = 14, 23.7%); quality of life (n = 9, 15.3%); and other issues (n = 5, 8.5%). The median number of items was 29 (4-125): 20/59 instruments (33.9%) had ≤20 items; 13 (22%) had ≤20 items and were psychometrically sound, with 12 of these 13 (92.3%) being self-report questionnaires. There were 44 instruments (74.6%) that measured caregiver distress for adult cancer patients and 15 (25.4%) for caregivers of pediatric patients. SIGNIFICANCE OF RESULTS: There is a significant number of cancer caregiver instruments that are self-reported, concise, and psychometrically sound, which makes them attractive for further research into their clinical use, outcomes, and effectiveness.


Asunto(s)
Cuidadores/psicología , Psicometría/instrumentación , Estrés Psicológico/psicología , Adulto , Aflicción , Femenino , Humanos , Masculino , Neoplasias/complicaciones , Neoplasias/psicología , Pacientes/psicología , Estrés Psicológico/complicaciones , Encuestas y Cuestionarios
7.
J Nanosci Nanotechnol ; 16(2): 1793-7, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27433672

RESUMEN

Fischer-Tropsch synthesis (FTS) was carried out over nanocrystalline ferrihydrite-based (Fe9O2(OH)23) catalysts activated by different reducing agents: syngas (H2+CO), CO, and H2. The syngas activation successfully changed the ferrihydrite-based catalysts into an active and stable catalytic structure with chi-carbide (Fe2.5 C) and epsilon'-carbide (Fe2.2 C). The crystal structure of the catalysts obtained by syngas activation was similar to the structure obtained by CO activation; this similarity was probably due to the peculiar reduction behavior of the ferrihydrite-based catalysts, which exhibit much greater reducibility in CO atmosphere than in H2 atmosphere. The performance of the catalysts activated by syngas was much higher than the performance of the catalysts activated by H2 and was comparable to the performance of the catalysts activated by CO. This strongly demonstrates that the ferrihydrite-based catalysts are advantageous for industrial FTS processes because syngas can be commonly used for both activation pre-treatment and subsequent reaction.


Asunto(s)
Monóxido de Carbono/química , Compuestos Férricos/química , Hidrógeno/química , Nanopartículas/química , Catálisis
8.
Oncologist ; 20(6): 692-7, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25933929

RESUMEN

BACKGROUND: In this prospective study, we determined the frequency of opioid-related chemical coping among advanced cancer patients, as diagnosed by palliative medicine specialists. We also determined predictors for chemical coping and the concordance between the physician's diagnosis and documentation in the medical records. PATIENTS AND METHODS: Palliative medicine specialists evaluated and diagnosed consecutive patients seen for chemical coping. The proportion of patients identified as chemically coping was compared with the proportion documented in the medical records. Demographic data; cancer diagnosis; history of smoking; substance abuse; psychiatric disease; morphine equivalent daily dosage; Cut-down, Annoyed, Guilty, and Eye-opener (CAGE) questionnaire scores; and Edmonton Symptom Assessment System scores were also collected. RESULTS: A total of 432 patients were evaluated. Overall, 76 patients (18%; 95% confidence interval [CI]: 14%-21%) were diagnosed as chemically coping. Documentation of chemical coping in the medical records was reported for only 15 patients (4%; 95% CI: 2%-6%). CAGE positivity (odds ratio [OR]: 2.89), younger age (OR: 0.97 per year), better performance status (OR: 0.68 per point), pain (OR: 1.20 per point), and well-being (OR: 1.28 per point) were found to be significant predictors of chemical coping by protocol definition. After recursive partitioning, 21 of 50 patients (42%) who were CAGE positive and had an Eastern Cooperative Oncology Group performance status ≤2 were diagnosed as chemically coping. CONCLUSION: Approximately 18% of palliative care patients seen were diagnosed as chemically coping by palliative medicine specialists. The frequency of documentation in the medical records was significantly lower. Better and safer ways for physicians to assess and report chemical coping are needed. IMPLICATIONS FOR PRACTICE: Cancer pain is a multidimensional symptom for which opioids are the mainstay of treatment. However, opioids can have a double effect resulting in drug-seeking behaviors. Chemical coping occurs when a patient uses opioids in a nonprescribed way to cope with various stressful events. This can lead to misuse of opioids and complications including neurotoxicities, respiratory depression, and death. Proper diagnosis and documentation is needed to ensure proper management of pain and to avoid unnecessary harm. The findings of this study suggest that ∼18% of advanced cancer patients seen by a palliative care service were diagnosed as chemical coping, but only 4% were documented in the medical records.


Asunto(s)
Morfina/efectos adversos , Dolor/fisiopatología , Medicina Paliativa , Anciano , Femenino , Humanos , Masculino , Registros Médicos , Persona de Mediana Edad , Morfina/administración & dosificación , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Neoplasias/fisiopatología , Dolor/tratamiento farmacológico , Dolor/etiología , Encuestas y Cuestionarios
9.
Oncologist ; 20(1): 77-83, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25480826

RESUMEN

BACKGROUND: Both the American Society of Clinical Oncology and the European Society for Medical Oncology strongly endorse integrating oncology and palliative care (PC); however, a global consensus on what constitutes integration is currently lacking. To better understand what integration entails, we conducted a systematic review to identify articles addressing the clinical, educational, research, and administrative indicators of integration. MATERIALS AND METHODS: We searched Ovid MEDLINE and Ovid EMBase between 1948 and 2013. Two researchers independently reviewed each citation for inclusion and extracted the indicators related to integration. The inter-rater agreement was high (κ = 0.96, p < .001). RESULTS: Of the 431 publications in our initial search, 101 were included. A majority were review articles (58%) published in oncology journals (59%) and in or after 2010 (64%, p < .001). A total of 55 articles (54%), 33 articles (32%), 24 articles (24%), and 14 articles (14%) discussed the role of outpatient clinics, community-based care, PC units, and inpatient consultation teams in integration, respectively. Process indicators of integration include interdisciplinary PC teams (n = 72), simultaneous care approach (n = 71), routine symptom screening (n = 25), PC guidelines (n = 33), care pathways (n = 11), and combined tumor boards (n = 10). A total of 66 articles (65%) mentioned early involvement of PC, 18 (18%) provided a specific timing, and 28 (28%) discussed referral criteria. A total of 45 articles (45%), 20 articles (20%), and 66 articles (65%) discussed 8, 4, and 9 indicators related to the educational, research, and administrative aspects of integration, respectively. CONCLUSION: Integration was a heterogeneously defined concept. Our systematic review highlighted 38 clinical, educational, research, and administrative indicators. With further refinement, these indicators may facilitate assessment of the level of integration of oncology and PC.


Asunto(s)
Oncología Médica , Neoplasias/epidemiología , Cuidados Paliativos , Humanos , Neoplasias/patología , Neoplasias/terapia
10.
Oncologist ; 20(12): 1432-9, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26463869

RESUMEN

BACKGROUND: In a previous pilot study, adrenal suppression was found to be common after antiemetic dexamethasone therapy in cancer patients. The objective of this large prospective multicenter study was to confirm the incidence and factors associated with secondary adrenal suppression related to antiemetic dexamethasone therapy in cancer patients receiving chemotherapy. METHODS: Chemotherapy-naïve patients who were scheduled to receive at least three cycles of highly or moderately emetogenic chemotherapy with dexamethasone as an antiemetic were enrolled. Patients with a suppressed adrenal response before chemotherapy or those administered corticosteroids within 6 months of enrollment in the study were excluded. RESULTS: Between October 2010 and August 2014, 481 patients receiving chemotherapy underwent the rapid adrenocorticotropic hormone (ACTH) stimulation test to assess eligibility; 350 of these patients were included in the final analysis. Fifty-six patients (16.0%) showed a suppressed adrenal response in the rapid ACTH stimulation test at 3 or 6 months after the start of the first chemotherapy. The incidence of adrenal suppression was affected by age, performance status, stage, and use of megestrol acetate in univariate analysis. Multivariate analysis revealed that secondary adrenal suppression associated with antiemetic dexamethasone therapy was significantly associated with megestrol acetate treatment (odds ratio: 3.06; 95% confidence interval: 1.60 to 5.86; p < .001). CONCLUSION: This large prospective study indicates that approximately 15% of cancer patients receiving chemotherapy with a normal adrenal response show suppressed adrenal responses after antiemetic dexamethasone therapy. This result was particularly significant for patients cotreated with megestrol acetate.


Asunto(s)
Insuficiencia Suprarrenal/inducido químicamente , Antieméticos/efectos adversos , Dexametasona/efectos adversos , Neoplasias/tratamiento farmacológico , Insuficiencia Suprarrenal/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Dexametasona/administración & dosificación , Femenino , Humanos , Hidrocortisona/sangre , Masculino , Acetato de Megestrol/administración & dosificación , Persona de Mediana Edad , Prednisolona/uso terapéutico , Estudios Prospectivos , Resultado del Tratamiento , Adulto Joven
11.
Gynecol Oncol ; 139(3): 553-8, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26432043

RESUMEN

OBJECTIVE: The objective of this study was to delineate and measure the symptom distress experienced by patients with advanced cervical cancer at the time of palliative care (PC) referral. METHODS: A total of 156 patients with advanced cervical cancer were referred to PC from 2010 to 2012. Of these, 88 patients had completed the Edmonton Symptom Assessment System (ESAS) and were included in the analysis. RESULTS: The mean age was 45years (25-76), 47% were white, 18% were African American, and 33% were Hispanic. Fifty-one percent were married, 64% had no advance directives, and 75% had recurrent disease. Clinically significant symptoms recorded by patient reported outcome measurement (defined as ESAS scores ≥4) were pain (81%), anorexia (72%), a poor feeling of well-being (70%), fatigue (69%), and insomnia (54%). The chief complaint recorded for the visit was pain in 94% of patients. According to the PC specialists' assessment, pain (96%), emotional distress (77%), and constipation (50%) were predominant symptoms. Various PC interventions including opioids, laxatives, and expressive supportive counseling were provided. Clinically significant symptoms including nausea, depression, anxiety, and feeling of well-being were significantly improved at follow-up visits. CONCLUSION: More than half of patients with advanced cervical cancer were significantly burdened with pain, anorexia, a poor feeling of well-being, fatigue, insomnia, and constipation at the time of PC referral. This research is an integral step towards developing a standardized tool for assessing symptoms in women diagnosed with cervical cancer and thus maximizing effectiveness of patient centered care.


Asunto(s)
Cuidados Paliativos , Evaluación de Síntomas/métodos , Neoplasias del Cuello Uterino/complicaciones , Neoplasias del Cuello Uterino/terapia , Adulto , Anciano , Anorexia/etiología , Anorexia/terapia , Ansiedad/tratamiento farmacológico , Ansiedad/etiología , Estreñimiento/tratamiento farmacológico , Estreñimiento/etiología , Depresión/etiología , Depresión/terapia , Fatiga/etiología , Fatiga/terapia , Femenino , Humanos , Persona de Mediana Edad , Náusea/tratamiento farmacológico , Náusea/etiología , Dolor/tratamiento farmacológico , Dolor/etiología , Estudios Retrospectivos , Trastornos del Inicio y del Mantenimiento del Sueño/tratamiento farmacológico , Trastornos del Inicio y del Mantenimiento del Sueño/etiología , Estrés Psicológico/etiología , Estrés Psicológico/terapia , Neoplasias del Cuello Uterino/psicología
12.
Gastric Cancer ; 18(3): 644-52, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25098925

RESUMEN

BACKGROUND: Palliative chemotherapy is used to prolong survival among elderly patients with inoperable gastric cancer (GC). We analyzed differences between single and combination first-line palliative chemotherapy among these patients. METHODS: Included patients were >70 years old and were treated for GC at four clinical centers of the Catholic University of Korea. Baseline characteristics, the first-line chemotherapy regimen, treatment responses, toxicities, progression-free survival (PFS), and overall survival (OS) were evaluated. RESULTS: Between 2005 and 2012, 178 > 70-year-old patients with GC received palliative chemotherapy using single or combination regimens. Median ages were 77 years (range 71-89) in the single regimen group (SG, 70 patients) and 73 years (range 71-81) in the combination group (CG, 108 patients). Patients in the SG received S-1 or capecitabine. The most common regimen in the CG was platinum combined with fluorouracil. The most common response in both groups was stable disease (SG, 45.7 %; CG, 48.1 %). In the SG and CG, median PFS times were 4.4 months (95 % confidence interval [CI] 2.85-5.95) and 4.1 months (95 % CI 2.62-5.57; P = 0.295), respectively; median OS times were 6.6 months (95 % CI 4.17-9.08) and 7.6 months (95 % CI 5.50-9.69; P = 0.782), respectively. Hematologic (P < 0.001) and non-hematologic toxicities (P < 0.001) were more frequent in the CG. The most common causes of chemotherapy cessation were disease progression in the SG and decreased performance status in the CG. CONCLUSIONS: Single-agent treatment should be considered a first-line palliative chemotherapy option for elderly patients with GC.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/patología , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Capecitabina/administración & dosificación , Capecitabina/efectos adversos , Combinación de Medicamentos , Femenino , Fluorouracilo/administración & dosificación , Humanos , Estimación de Kaplan-Meier , Leucovorina , Masculino , Compuestos Organoplatinos , Ácido Oxónico/uso terapéutico , Cuidados Paliativos , Pronóstico , Estudios Retrospectivos , Neoplasias Gástricas/mortalidad , Tegafur/uso terapéutico , Resultado del Tratamiento
13.
J Nanosci Nanotechnol ; 14(2): 1872-83, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24749462

RESUMEN

This paper reviews recent developments in the field of hybrid Pd nanoparticles and their catalytic activity in the Suzuki coupling reaction, which is used extensively in the fabrication of both simple and complex biaryl compounds. We developed three types of Pd-silica hybrid nanoparticles. Pd/SiO2 nanobeads containing tiny Pd clusters, Pd@nickel phyllosilicate yolk-shell nanoparticles, Pd@porous SiO2 yolk-shell nanoparticles were synthesized, and they displayed highly efficient catalytic activity and excellent reusability. The hybrid nanoparticles also catalyzed the Suzuki coupling reaction with various substrates, including bromobenzene and chlorobenzene. This review also briefly discusses the synthesis procedure, structural characterization, and catalytic activity of hybrid Pd nanoparticles.


Asunto(s)
Ácidos Borónicos/química , Halógenos/química , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Paladio/química , Catálisis , Tamaño de la Partícula
14.
Nanomaterials (Basel) ; 13(4)2023 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-36839027

RESUMEN

Highly dispersed Pt-incorporated mesoporous Fe2O3 (Pt/m-Fe2O3) of 4 µm size is prepared through a simple hydrothermal reaction and thermal decomposition procedures. Furthermore, the formaldehyde gas-sensing properties of Pt/m-Fe2O3 are investigated. Compared with our previous mesoporous Fe2O3-based gas sensors, a gas sensor based on 0.2% Pt/m-Fe2O3 shows improved gas response by over 90% in detecting low-level formaldehyde gas at 50 ppb concentration, an enhanced selectivity of formaldehyde gas, and a lower degradation of sensing performance in high-humidity environments. Additionally, the gas sensor exhibits similar properties as the previous sensor, such as operating temperature (275 °C) and long-term stability. The enhancement in formaldehyde gas-sensing performance is attributed to the attractive catalytic chemical sensitization of highly dispersed Pt nanoparticles in the mesoporous Fe2O3 microcube architecture.

15.
J Gastric Cancer ; 23(2): 315-327, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37129155

RESUMEN

PURPOSE: Oxaliplatin, a component of the capecitabine plus oxaliplatin (XELOX) regimen, has a more favorable toxicity profile than cisplatin in patients with advanced gastric cancer (GC). However, oxaliplatin can induce sensory neuropathy and cumulative, dose-related toxicities. Thus, the capecitabine maintenance regimen may achieve the maximum treatment effect while reducing the cumulative neurotoxicity of oxaliplatin. This study aimed to compare the survival of patients with advanced GC between capecitabine maintenance and observation after 1st line XELOX chemotherapy. MATERIALS AND METHODS: Sixty-three patients treated with six cycles of XELOX for advanced GC in six hospitals of the Catholic University of Korea were randomized 1:1 to receive capecitabine maintenance or observation. The primary endpoint was progression-free survival (PFS), analyzed using a two-sided log-rank test stratified at a 5% significance level. RESULTS: Between 2015 and 2020, 32 and 31 patients were randomized into the maintenance and observation groups, respectively. After randomization, the median number of capecitabine maintenance cycles was 6. The PFS was significantly higher in the maintenance group than the observation group (6.3 vs. 4.1 months, P=0.010). Overall survival was not significantly different between the 2 groups (18.2 vs. 16.5 months, P=0.624). Toxicities, such as hand-foot syndrome, were reported in some maintenance group patients. Maintenance treatment was a significant factor associated with PFS in multivariate analysis (hazard ratio, 0.472; 95% confidence interval, 0.250-0.890; P=0.020). CONCLUSIONS: After 6 cycles of XELOX chemotherapy, capecitabine maintenance significantly prolonged PFS compared with observation, and toxicity was manageable. Maintenance treatment was a significant prognostic factor associated with PFS. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02289547.

16.
Langmuir ; 28(15): 6441-7, 2012 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-22443964

RESUMEN

The surface of Pd@SiO(2) core-shell nanoparticles (1) was simply modified by the formation of nickel phyllosilicate. The addition of nickel salts formed branched nickel phyllosilicates and generated pores in the silica shells, yielding Pd@SiO(2)-Niphy nanoparticles (Niphy = nickel phyllosilicate; 2, 3). By removal of the silica residue, Pd@Niphy yolk-shell nanoparticles (4) was uniformly obtained. The four distinct nanostructures (1-4) were employed as catalysts for Suzuki coupling reactions with aryl bromide and phenylboronic acid, and the conversion yields were in the order of 1 < 2 < 3 < 4 as the pore volume and surface area of the catalysts increased. The reaction rates were strongly correlated with shell porosity and surface exposure of the metal cores. The chemical inertness of nickel phyllosilicate under the basic conditions rendered the catalysts reusable for more than five times without loss of activity.

17.
Molecules ; 17(11): 13235-53, 2012 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-23132140

RESUMEN

Recent developments in the synthesis of CuO nanoparticles (NPs) and their application to the [3+2] cycloaddition of azides with terminal alkynes are reviewed. With respect to the importance of click chemistry, CuO hollow NPs, CuO hollow NPs on acetylene black, water-soluble double-hydrophilic block copolymer (DHBC) nanoreactors and ZnO–CuO hybrid NPs were synthesized. Non-conventional energy sources such as microwaves and ultrasound were also applied to these click reactions, and good catalytic activity with high regioselectivity was observed. CuO hollow NPs on acetylene black can be recycled nine times without any loss of activity, and water-soluble DHBC nanoreactors have been developed for an environmentally friendly process.


Asunto(s)
Alquinos/química , Azidas/química , Cobre/química , Nanopartículas/química , Acetileno/química , Catálisis , Química Clic , Reacción de Cicloadición , Tecnología Química Verde , Compuestos Heterocíclicos/síntesis química , Nanopartículas/ultraestructura , Povidona/química , Hollín/química , Termodinámica , Óxido de Zinc/química
18.
J Nanosci Nanotechnol ; 11(2): 1037-41, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21456135

RESUMEN

A various size of Sn-Cu nanoparticles were synthesized by using a modified polyol process for low temperature electronic devices. Monodispersive Sn-Cu nanoparticles with diameters of 21 nm, 18 nm and 14 nm were synthesized. In addition, the eutectic composition shift was also observed in nano-sized particles as compared with bulk alloys. By controlling the size and eutectic composition, a significant melting temperature depression of 30.3 degrees C was achieved. These melting temperature depression approaches will reduce adverse thermal effects in electronic devices and provide the synthesis guidelines for bimetallic nanoparticles with a low melting temperature.

19.
Langmuir ; 26(21): 16469-73, 2010 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-20481526

RESUMEN

We have synthesized Pt@silica/nickel phyllosilicate and Pt@silica yolk-shell nanostructures from NiPt@silica core-shell particles by simple chemical treatments. Silica coating of the NiPt alloy nanoparticles via the microemulsion method yielded spherical NiPt@silica core-shell nanoparticles with an average core diameter of 6.5 nm. Under a reflux condition in water, the core-shell structure transformed into Pt@silica yolk-shell nanoparticles with branched nickel phyllosilicate, which exhibited high surface area and large pore volume. The addition of hydrochloric acid selectively etched the nickel component from the NiPt cores and yielded Pt@silica yolk-shell nanoparticles with single-crystalline platinum cores. The average diameter of the metal cores was reduced to 4.5 nm. In both cases, the nickel components behaved as sacrificial spacers and successfully formed a vacancy between the metal cores and the silica hollow shells.

20.
J Nanosci Nanotechnol ; 10(10): 6504-9, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21137753

RESUMEN

An approach for gram-scale synthesis of uniform Cu2O nanocubes by a one-pot polyol process was used. The CuO hollow nanostructures were prepared by adding aqueous ammonia solutions with Cu2O nanocube colloidal solutions. CuO hollow nanospheres on acetylene black (CuO/AB), were synthesized and used for the catalytic [3+2] cycloaddition of azides with terminal alkynes to provide products in good yields with high regioselectivity. The CuO/AB was readily separated by centrifugation and could be reused ten times under the present reaction conditions without any loss of catalytic activity. Transition metals loaded onto acetylene black are useful reagents for a wide variety of organic transformations. Moreover, these heterogeneous systems are promising industrial catalysts.

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