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1.
Am J Hematol ; 99(1): 28-37, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37851608

RESUMEN

Acquired hemophilia A (AHA) is a rare but serious bleeding disorder. Randomized controlled trial (RCT) comparing the efficacy of immunosuppression therapy for AHA lacks. We conducted the first multicenter RCT aiming to establish whether the single-dose rituximab combination regimen was noninferior to the cyclophosphamide combination regimen. From 2017 to 2022, 63 patients with newly diagnosed AHA from five centers were randomly assigned 1:1 to receive glucocorticoid (methylprednisolone 0.8 mg/kg per day for the first 3 weeks and then tapered) plus single-dose rituximab (375 mg/m2 ; n = 31) or plus cyclophosphamide (2 mg/kg per day until inhibitor becomes negative, for a maximum of 5 weeks; n = 32). The primary outcome was complete remission (CR, defined as FVIII activity ≥50 IU/dL, FVIII inhibitor undetectable, immunosuppression tapered and no bleeding for 24 h without bypassing agents) rate measured within 8 weeks. The noninferiority margin was an absolute difference of 20%. Twenty-four (77.4%) patients in the rituximab group and 22 (68.8%) patients in the cyclophosphamide group achieved CR, which showed the noninferiority of the single-dose rituximab-based regimen (absolute difference = -8.67%, lower limit of the 95% confidence interval = -13.11%; Pnoninferiority = 0.005). No difference was found in the incidence of treatment-related adverse events. Single-dose rituximab plus glucocorticoid regimen showed similar efficacy and safety, without a reported risk of secondary malignancies or reproductive toxicity seen in cyclophosphamide, it might be recommended as a first-line therapy for AHA, especially in China where there is a young age trend in AHA patients. This trial was registered at ClinicalTrials.gov as #NCT03384277.


Asunto(s)
Glucocorticoides , Hemofilia A , Humanos , Ciclofosfamida/uso terapéutico , Glucocorticoides/uso terapéutico , Hemofilia A/tratamiento farmacológico , Metilprednisolona/uso terapéutico , Rituximab/uso terapéutico , Resultado del Tratamiento , Quimioterapia Combinada/efectos adversos
2.
Haemophilia ; 28(6): e219-e227, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35996199

RESUMEN

INTRODUCTION: Current treatment of severe haemophilia A includes prophylaxis with factor VIII (FVIII) replacement. The supply of plasma-derived FVIII is short in China. PURPOSE: To evaluate the efficacy and safety of a new B-domain deleted (BDD) recombinant FVIII (TQG202) produced by human-derived cells for prophylaxis in severe haemophilia A patients and compare the bioequivalence with Xyntha. METHODS: This multicentre, clinical trial consisted of an open-label, randomized, two-period cross-over trial assessing single-dose pharmacokinetics (PK), and a single-arm clinical trial evaluating the efficacy and safety of 24 weeks of TQG202 prophylaxis, and repeated PK were assessed after prophylaxis phase. The single-dose was 50 IU/kg in PK assessment, and the initial dose was 30 ± 5 IU/kg for prophylaxis. The primary endpoints of prophylaxis were the annualized bleeding rate (ABR) and the incremental recovery rate of the first administration. Adverse events (AEs) were recorded. RESULTS: Twenty-six participants were enrolled in the PK assessment and 81 participants in the prophylaxis phase. Mean age was 25.9 ± 10.8 years and all participants were male. The results of PK assessment showed TQG202 is bioequivalent to Xyntha. The total ABR was 2.0 (95% CI: 1.2-2.9) in prophylaxis phase. The mean incremental recovery rate of the first administration was .027 (95% CI: .026-.028) (IU/ml)/(IU/kg). AEs occurred in 42 participants, with an incidence of 51.9%. One severe AE not related to TQG202 occurred. No participants developed FVIII inhibitors. CONCLUSION: TQG202 shows bioequivalence with Xyntha. The promising efficacy and tolerability in the severe haemophilia A prophylaxis support the use of TQG202in clinical practice.


Asunto(s)
Hemofilia A , Hemostáticos , Adolescente , Adulto , Humanos , Masculino , Adulto Joven , Factor VIII/farmacocinética , Hemofilia A/tratamiento farmacológico , Hemorragia/prevención & control , Hemorragia/tratamiento farmacológico , Hemostáticos/uso terapéutico , Equivalencia Terapéutica
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 39(6): 597-601, 2022 Jun 10.
Artículo en Zh | MEDLINE | ID: mdl-35773762

RESUMEN

OBJECTIVE: To investigate the molecular pathogenesis of two coagulation factor Ⅺ (FⅪ) deficiency patients. METHODS: Coagulant assays: activated partial thromboplastin time (APTT), normal pooled-plasma corrected APTT test, PT, PT-INR and one-stage assay of coagulation factors activities were validated to diagnose coagulation factor Ⅺ deficiency. The patients' DNA samples were extracted and all exons and flanking sequences of F11 gene were amplified using PCR. After purified, the products of PCR were sequenced directly, the mutations were detected by comparing with wild sequences and analyzed using some bio-informatics softwares. RESULTS: The two patients were diagnosed with coagulation factor Ⅺ deficiency due to prolonged APTT, corrected APTT and low activities of coagulation factor FⅪ. The results of APTT, FⅪ: C were 88.1s, 1.1% and 107.1s, 3.8%, and the prolonged APTT could be corrected to normal range 32.9 s and 31.5 s, respectively. Through genetic analysis, we discovered compound heterozygous mutations g.1305-1G>A and g.1325delT in patient 1 and the sequencing results of TA plasmid clones showed that the two mutations were located on different strands of chromosomes. Compound heterozygous mutations g.1124A>G and g.1550C>G were detected in patient 2 resulting in Lys357Arg and Cys482Trp. Software analysis indicated the mutations probably brought amino acid sequence changed, protein features affected and splice site changed. CONCLUSION: Compound heterozygous mutations g.1305-1G>A, g.1325delT and g.1124A>G, g.1550C>G had been identified in two coagulation factor Ⅺ deficiency patients which might be responsible for their prolonged APTT and low FⅪ: C. To the best of our knowledge, g.1325delT and g.1550C>G have been reported, while g.1124A>G and g.1305-1G>A are reported for the first time in the literature.


Asunto(s)
Deficiencia del Factor XI , Factor XI , Exones , Factor XI/genética , Deficiencia del Factor XI/genética , Heterocigoto , Humanos , Mutación , Linaje
4.
Inorg Chem ; 60(4): 2219-2227, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33507746

RESUMEN

Materials with near-infrared (NIR) persistent luminescence (PersL) and NIR-to-NIR photostimulated luminescence (PSL) properties are attractive platforms for photonic energy harvesting and release. In this work, we develop Mg2SnO4:Cr as a broadband NIR PersL and NIR-to-NIR PSL material (luminescence maxima at ∼800 nm) and reveal the origin of the PersL and PSL properties. The material has an inverse spinel structure with the Mg2+ and Sn4+ disorder at the Wyckoff 16d site based on the Rietveld refinement. Cr K-edge X-ray absorption near-edge structure (XANES) spectra uncover that the doped Cr ions have a +3 valence state and occupy the disordered (Mg,Sn) site with octahedral coordination. The disorder results in multiple Cr3+ centers, and the broadband luminescence originates from the 4T2(4F) → 4A2 transition of Cr3+ at sites with intermediate crystal field strength. The distribution of trap depths is continuous according to the analysis of thermoluminescence (TL) spectra using the initial rising method, which relates to the random distribution of Mg2+ and Sn4+ at the second coordination sphere of the Cr3+ centers rather than the oxygen-related defects. Stimulating the material with a NIR laser, the NIR PersL gets significantly enhanced due to a PSL process. The broadband PersL and PSL are detectable beyond 100 h and have good tissue penetrability and therefore the developed Mg2SnO4:Cr3+ has potential in applications of optical information storage/reading and autofluorescence-free bioimaging. Finally, three crystal and electronic structure factors are proposed for screening new Cr3+-activated PersL and PSL materials.

5.
Haemophilia ; 26(1): 129-135, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31657079

RESUMEN

INTRODUCTION AND AIMS: Age-related severity and distribution of haemophilic arthropathy (HA) among Chinese patients with haemophilia using the Haemophilia Early Detection with Ultrasound (HEAD-US) system have not been extensively studied. METHODS: In our study, 89 patients with moderate and severe haemophilia were recruited. A total of 534 joints (knees, ankles and elbows on both sides included) were evaluated using musculoskeletal ultrasound (MSKUS) and scored using the HEAD-US system. RESULTS: Prevalence and average number of HA were 39.1% and 0.7, 90.6% and 3.2, 94.1% and 4.5, and 100% and 4.3 for ages ≤10, 11-20, 21-30 and 31-40 years, respectively. Prevalence and mean number of knee, ankle and elbow arthropathies also increased with age, although joint damages progressed in unparallel patterns. A significant difference in synovium subscores was observed between patients aged <10 and >10 years. An increasing tendency was observed in cartilage and subchondral bone subscores along with age before 30 years. No significant difference in mean joint scores was found between patients receiving on-demand therapy and those receiving on-demand to low-dose prophylactic therapy. CONCLUSIONS: Haemophilic arthropathy developed in early childhood and progressed mainly before 30 years of age among Chinese patients with haemophilia, although in different ways among the knee, ankle and elbow.


Asunto(s)
Tobillo/patología , Pueblo Asiatico , Codo/patología , Hemofilia A/complicaciones , Artropatías/complicaciones , Rodilla/patología , Adolescente , Adulto , Distribución por Edad , Factores de Edad , Tobillo/diagnóstico por imagen , Niño , Preescolar , Codo/diagnóstico por imagen , Hemofilia A/tratamiento farmacológico , Humanos , Artropatías/diagnóstico por imagen , Rodilla/diagnóstico por imagen , Prevalencia , Índice de Severidad de la Enfermedad , Membrana Sinovial/diagnóstico por imagen , Membrana Sinovial/patología , Adulto Joven
6.
Inorg Chem ; 59(23): 17421-17429, 2020 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-33183001

RESUMEN

RbBaPO4:Eu2+ phosphors have been prepared by a high-temperature solid-state reaction method, and the structure was determined by Rietveld refinement based on powder X-ray diffraction (P-XRD) data. Their VUV-UV-vis photoluminescence properties are systematically investigated with three objectives: (1) based on low-temperature spectra, we clarify the site occupancies of Eu2+, and demonstrate that the doublet emission bands at ∼406 and ∼431 nm originate from Eu2+ in Ba2+ [Eu2+(I)] and Rb+ [Eu2+(II)] sites, respectively; (2) an electron-vibrational interaction (EVI) analysis is conducted to estimate the Huang-Rhys factors, the zero-phonon lines (ZPLs) and the Stokes shifts of Eu2+ in Rb+ and Ba2+ sites; (3) the studies on luminescence decay of Eu2+(I) reveal that dipole-dipole interaction is mainly responsible for the energy transfer from Eu2+(I) to Eu2+(II), and the energy migration between Eu2+(I) is weak. Finally, the X-ray excited luminescence (XEL) spectrum indicates that the light yield of the sample RbBa0.995Eu0.005PO4 is ∼17 700 ph/MeV, showing its potential application in X-ray detecting.

7.
Phys Chem Chem Phys ; 22(38): 22096-22106, 2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-32990291

RESUMEN

In this work, the coordination polyhedron stabilities and distributions of europium ions in Ca6BaP4O17 (CBPO) luminescent materials are investigated. The density functional theory (DFT)-based first principles calculation results show that the PO4 tetrahedrons can tilt in the structure, which leads to the atomic distortion of O13 and O12 in CBPO and the Eu2+/Eu3+-doped systems. The energy scale of about ∼0.1 eV suggests that stabilities of coordination polyhedrons are easily influenced by dynamic factors. The atomic distortion and vacancy of work as charge compensations in CBPO:Eu3+, and three lattice sites of europium are extracted and summarized. The X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) confirm that Eu3+ can occupy the Ca1, Ca2 and Ba sites of CBPO. The combination of first principles calculation and X-ray absorption fine structure (XAFS) provides more information about microstructures of luminescent materials.

8.
Angew Chem Int Ed Engl ; 59(52): 23810-23816, 2020 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-32914560

RESUMEN

Optical multiplexing based on luminescent materials with tunable color/lifetime has potential applications in information storage and security. However, the available tunable luminescent materials reported so far still suffer from several drawbacks of low efficiency or poor stability, thus restraining their further applications. Herein, we demonstrate a strategy to develop efficient and stable lanthanide coordination polymers (LCPs) with tunable luminescence as a new option for optical multiplexing. Their multicolor emission from green to red and naked-eye-sensitive green emission with tunable lifetime (from ca. 300 to ca. 600 µs) can be controlled by host differential sensitization and energy transfer between lanthanide ions. The quantum efficiencies of developed samples range from around 20 % to 46 % and the luminescence intensity/lifetime appear quite stable in polar solvents up to ten weeks. Furthermore, with the aid of inkjet printing and concepts of luminescence lifetime imaging and time-gated imaging, we illustrate their promising applications of information storage and security in spatial and temporal domains.

10.
Inorg Chem ; 57(12): 7090-7096, 2018 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-29863341

RESUMEN

Knowledge of site occupation of activators in phosphors is of essential importance for understanding and tailoring their luminescence properties by modifying the host composition. Relative site preference of Eu2+ for the two distinct types of alkaline earth (AE) sites in Ba1.9995- xSr xEu0.0005SiO4 ( x = 0-1.9) is investigated based on photoluminescence measurements at low temperature. We found that Eu2+ prefers to be at the 9-coordinated AE2 site at x = 0, 0.5, and 1.0, while at x = 1.5 and 1.9, it also occupies the 10-coordinated AE1 site with comparable preference, which is verified by density functional theory (DFT) calculations. Moreover, by combining low-temperature measurements of the heat capacity, the host band gap, and the Eu2+ 4f7 ground level position, the improved thermal stability of Eu2+ luminescence in the intermediate composition ( x = 1.0) is interpreted as due to an enlarged energy gap between the emitting 5d level and the bottom of the host conduction band (CB), which results in a decreased nonradiative probability of thermal ionization of the 5d electron into the host CB. Radioluminescence properties of the samples under X-ray excitation are finally evaluated, suggesting a great potential scintillator application of the compound in the intermediate composition.

11.
Inorg Chem ; 56(20): 12476-12484, 2017 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-28952724

RESUMEN

A series of Ce3+-doped (Ca,Sr)2Al2SiO7 phosphors with different Ce3+ and Ca2+/Sr2+ concentrations were prepared by a high temperature solid-state reaction technique. To get insight into the structure-luminescence relationship, the impact of incorporation of Sr2+ on structure of (Ca,Sr)2Al2SiO7 was first investigated via Rietveld refinement of high quality X-ray diffraction (XRD) data, and then the VUV-UV excitation and UV-vis emission spectra of (Ca,Sr)2Al2SiO7:Ce3+ were collected at low temperature. The results reveal that the crystal structure evolution of (Ca,Sr)2Al2SiO7:Ce3+ has influences on band gaps and Ce3+ luminescence properties including 4f-5di (i = 1-5) transition energies, radiative lifetime, emission intensity, quantum efficiency, and thermal stability. Moreover, the influence of Sr2+ content on the energy of Eu3+-O2- charge-transfer states (CTS) in (Ca,Sr)2Al2SiO7:Eu3+ was studied in order to construct vacuum referred binding energy (VRBE) schemes with the aim to further understand the luminescence properties of (Ca,Sr)2Al2SiO7:Ce3+. Finally, X-ray excited luminescence (XEL) spectra were measured to evaluate the possibility of (Ca,Sr)2Al2SiO7:Ce3+ as a scintillation material.

12.
J Thromb Thrombolysis ; 44(1): 139-144, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28425010

RESUMEN

To identify the pathogenesis of a Chinese woman diagnosed with dysfibrinogenemia. A patient from Nanjing presented with a low plasma concentration of fibrinogen and a normal level of antigen of fibrinogen. This abnormality was also detected in her son. To detect whether the genetic mutation was responsible for the dysfibrinogenemia, genomic DNA was extracted and amplified by polymerase chain reaction, and DNA sequencing was performed on the purified PCR products. Restriction fragment length polymorphism (RFLP), molecular modeling and homologous sequences alignment were performed. Two heterozygous missense variants, AαArg16His and γAsp185Asn, were discovered in the proband. Only the former was detected in her son. AαArg16His had been reported by other teams, and γAsp185Asn was identified first in our study as a novel variant. RFLP was performed and indicated that the novel failed to be found in normal subjects. Furthermore, it was suggested to be responsible for dysfibrinogenemia depending on the molecular modeling and homologous sequence alignment. The heterozygous AαArg16His and γAsp185Asn identified in the study probably underlie the dysfibrinogenemia in this pedigree, with the latter being identified for the first time.


Asunto(s)
Afibrinogenemia/genética , Fibrinógeno/genética , Fibrinógenos Anormales/genética , Mutación Missense , Linaje , Adulto , Sustitución de Aminoácidos , Femenino , Humanos
14.
Tumour Biol ; 35(7): 6757-62, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24719189

RESUMEN

This study aims to investigate the prognostic significance of the MYC protein expression in diffuse large B cell lymphoma (DLBCL) patients treated with RCHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone). A total of 60 patients with DLBCL from 2008 to 2013 were included. Formalin-fixed, paraffin-embedded DLBCL samples were analyzed for MYC protein expression and divided into high or low MYC group. The MYC protein expression and the international prognostic variables were evaluated. The high MYC protein expression predicted a shorter 3-year estimated overall survival (OS) and progression-free survival (PFS) versus the low MYC protein expression (57 % vs. 96 %, P < 0.001 and 50 % vs. 96 %, P = 0.001, respectively). Multivariate analysis confirmed the prognostic significance of the MYC protein expression for both OS (HR, 11.862; 95 % CI, 1.462-96.218; P = 0.021) and PFS (HR, 6.073; 95 % CI, 1.082-34.085; P = 0.040). MYC protein expression with International Prognostic Index (IPI) score distinguished patients into three risk groups with different 3-year OS rates (χ (2) 23.079; P < 0.001) and distinct 3-year PFS rates (χ (2) 15.862; P < 0.001). This study suggests that the MYC protein expression is an important inferior prognostic factor for survival in patients with DLBCL treated with RCHOP. The combinative model with IPI score and MYC protein expression could stratify DLBCL patients into prognostically relevant subgroups more effectively than either the IPI or the MYC alone.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Proteínas Proto-Oncogénicas c-myc/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales de Origen Murino/administración & dosificación , Ciclofosfamida/administración & dosificación , Supervivencia sin Enfermedad , Doxorrubicina/administración & dosificación , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Linfoma de Células B Grandes Difuso/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Prednisona/administración & dosificación , Pronóstico , Proteínas Proto-Oncogénicas c-myc/biosíntesis , Rituximab , Vincristina/administración & dosificación
15.
Neurol Sci ; 33(4): 881-6, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22160751

RESUMEN

Autologous haematopoietic stem cell transplantation (AHSCT) is a promising treatment for multiple sclerosis (MS) patients who have not adequately responded to conventional therapies. We retrospectively evaluated the safety and long-term clinical outcome of AHSCT in MS patients in China. Twenty-five patients with various types of MS were treated with AHSCT. Peripheral blood stem cells were derived by leukapheresis after mobilized with granulocyte colony-stimulating factor. Then CD34+ cell selection of the graft was performed and anti-thymocyte globulin was given for T-cell depletion, with the conditioning regimen BEAM adopted and early and late toxicities recorded. Long-term responses were evaluated by the expanded disability status scale (EDSS), progression-free survival and gadolinium-enhanced magnetic resonance imaging scans. 10, 7 and 8 patients experienced neurological improvement, stabilization and progression, respectively. The median EDSS scores observed over 1-year follow-up after transplantation (5.5-7.0) were consistently lower than the baseline (8.0). The progression-free survival rate was 74, 65 and 48% at 3, 6 and 9 years post-transplant. 58% cases (7/12) had active lesions at baseline and all turned to inactive status in the years of follow-up. 25% cases (3/12) experienced progression after transplantation but had no active lesions in MRI over the whole follow-up period. 17% cases (2/12) without active lesions at baseline progressed active lesions in MRI. The major early toxicity resulted in fever and late toxicity caused transplantation-related mortality due to severe pneumonia and varicella-zoster virus hepatitis, respectively. AHSCT is a feasible treatment for severe MS and its long-term efficacy is favorable.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Esclerosis Múltiple/cirugía , Adolescente , Adulto , Antígenos CD34/metabolismo , China , Evaluación de la Discapacidad , Supervivencia sin Enfermedad , Femenino , Factor Estimulante de Colonias de Granulocitos/sangre , Humanos , Estimación de Kaplan-Meier , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/sangre , Examen Neurológico , Timocitos/metabolismo , Adulto Joven
16.
Cell Transplant ; 31: 9636897211070238, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35073786

RESUMEN

To explore a more effective conditioning regimen for umbilical cord blood transplantation (UCBT) to treat hematologic malignancies, we conducted a cohort study of a fludarabine/busulfan/cytarabine plus cyclophosphamide 200 mg/kg regimen. Forty-two consecutive patients with leukemia, myelodysplastic syndrome, or lymphoma received the regimen. The median number of infused total nucleated cells per kilogram was 5.5 × 107 (1.81-20.6), the median number of infused CD34+ cells per kilogram was 1.58 × 105 (0.58-6.6), and the median follow-up for surviving patients was 37 months (4.0-79.5 months). The cumulative incidence of neutrophil engraftment at 31 days was 100% [95% confidence interval (CI): 0.9159-1.0], and the median time to neutrophil engraftment was 19 days. The cumulative incidence of nonrelapse mortality was 12.76% (95% CI: 0.0455-0.2356) at 180 days and 3 years. The 3-year overall survival (OS) and disease-free survival (DFS) rates were 71.6% and 59.6%, respectively. Especially in patients who received transplants in the early and intermediate stages, the 3-year OS and DFS rates were 90.3% (95% CI: 0.805-1.0) and 76.2% (95% CI: 0.608-0.956), respectively. The regimen significantly improved engraftment and survival, indicating that the high graft failure of UCBT was caused by rejection.


Asunto(s)
Trasplante de Células Madre de Sangre del Cordón Umbilical , Enfermedad Injerto contra Huésped , Enfermedades Hematológicas , Neoplasias Hematológicas , Estudios de Cohortes , Trasplante de Células Madre de Sangre del Cordón Umbilical/efectos adversos , Enfermedad Injerto contra Huésped/etiología , Enfermedades Hematológicas/complicaciones , Neoplasias Hematológicas/terapia , Humanos , Estudios Retrospectivos , Acondicionamiento Pretrasplante
17.
Dalton Trans ; 51(2): 608-617, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34904979

RESUMEN

Non-equivalent or non-octahedral substitution is a crucial strategy to gain Mn4+-doped fluoride red phosphors with a short fluorescence lifetime, whereas the impact of their structural defects on the photoluminescence (PL) properties remains unrevealed. Here, a non-equivalently doped RbSbF6:Mn4+ (RSFM) with a high quantum efficiency of 88% and a thermal stability of 121% at 425 K is newly reported to probe the defect-related PL behavior. Formation energy calculations imply that an interstitial defect was formed to balance the charge and stabilize the crystal structure. Concentration-dependent decay studies reveal that Mn4+ emission is quenched mainly by energy transfer to a neighboring defect . The large ionic radius of Sb5+ and defect leading to a premature optimal doping (0.11 mol%) is demonstrated by the refined contrast of the crystal structure and substitution mode among various Mn4+-doped prototypes. A couple of medium 4T2 state energies and the energy difference between the Mn4+ level with the valence band maximum enable its superior thermal stability. A higher defect concentration slightly aggravates this thermal quenching. Using the RSFM red phosphor in a white light-emitting diode offers a wide-color-gamut of 121% NTSC for backlight displays. This work would provide a new perspective to understand the defect effect on the PL behavior of special Mn4+ asymmetrically doped fluorides.

18.
Chemosphere ; 301: 134590, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35427661

RESUMEN

A better understanding of different retention mechanisms of potentially toxic elements (PTEs) by biochars during the remediation of contaminated sites is critically needed. In this study, different spectroscopic techniques including synchrotron-based micro-X-ray fluorescence (µ-XRF), X-ray absorption fine structure (XAFS), and near-edge XAFS spectroscopy (NEXAFS), were used to investigate the spatial distributions and retention mechanisms of lead (Pb) and copper (Cu) on phytolith-rich coconut-fiber biochar (CFB), and ammonia, nitric acid and hydrogen peroxide modified CFB (MCFB) (i.e., ACFB, NCFB and HCFB). The µ-XRF analyses indicated that sorption sites on ACFB and NCFB were more efficient compared to those on CFB and HCFB to bind Pb/Cu. XAFS analyses revealed that the percentage of Pb species as Pb(C2H3O2)2 increased from 22.2% (Pb-loaded CFBs) to 47.4% and 41.9% on Pb-loaded NCFBs and HCFBs, while the percentage of Cu(OH)2 and Cu(C2H3O2)2 increased from 5.8% to 32.8% (Cu-loaded CFBs) to 41.5% and 43.4% (Cu-loaded NCFBs), and 27.1% and 35.1% (Cu-loaded HCFBs), respectively. Due to their similar atomic structures of Pb/Cu, Pb(C2H3O2)2/Pb-loaded montmorillonite and Cu(C2H3O2)2/Cu(OH)2 were identified as the predominant Pb/Cu species observed in Pb- and Cu-loaded MCFBs. The NEXAFS analyses of carbon confirmed that increasing amounts of carboxylic groups were formed on HCFB and NCFB by oxidizing carbon-containing functional groups, which could provide additional active binding sites for Pb/Cu retention. Results from the X-ray photoelectron spectroscopy analyses of nitrogen showed that azido-groups of ACFB played major roles in Pb/Cu retention, while amide-groups and pyridine-groups of NCFB primarily participated in Pb/Cu retention. Overall, density functional theory calculations suggested that silicate and the synergistic effect of hydroxyl and carboxylic-groups on MCFBs were highly efficient in Pb retention, while azido-groups and/or carboxylic-groups played major roles in Cu retention. These results provide novel insights into the PTE retention mechanisms of MCFBs.


Asunto(s)
Cobre , Contaminantes del Suelo , Carbono , Carbón Orgánico/química , Cocos/química , Cobre/química , Teoría Funcional de la Densidad , Plomo , Espectroscopía de Fotoelectrones , Contaminantes del Suelo/análisis
19.
Zhonghua Nei Ke Za Zhi ; 50(10): 859-62, 2011 Oct.
Artículo en Zh | MEDLINE | ID: mdl-22321329

RESUMEN

OBJECTIVE: To study the relationship between polymorphism of genes XPA, XPC, XPD, XRCC1 and susceptibility to acute lymphoblastic leukemia (ALL) in a Chinese population. METHODS: Polymorphism were determined by a case-control study through matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry method of Mass-ASSAY platform in 114 confirmed ALL cases and 169 age- and sex-matched controls, so as to compare the relationship between different genotypes and ALL risk. RESULTS: Multivariate logistic regression analysis revealed that individuals carrying at least one 23G variant allele (AG/GG genotypes) had a significantly increased risk for ALL (adjusted OR 2.02; 95%CI 1.08 - 3.78) compared with the wild-type genotype (23AA), and evidence that positive interactions between the polymorphisms in XPC C499T and XPA A23G might occur. Furthermore, individuals with both putative risk genotypes had a significantly higher risk (adjusted OR 5.60; 95%CI 1.57 - 19.90), compared with those with both wild-genotypes. By contrast, no significant association was observed between the XPD T751G, XRCC1 G399A, C194T polymorphism and ALL risk. CONCLUSIONS: XPA A23G and XPC C499T polymorphism may contribute to the risk of developing ALL. There are significant combinations between XPC C499T and XPA A23G.


Asunto(s)
Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Adulto , Anciano , Alelos , Pueblo Asiatico/genética , Estudios de Casos y Controles , Niño , Reparación del ADN , Proteínas de Unión al ADN/genética , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X , Proteína de la Xerodermia Pigmentosa del Grupo A/genética , Proteína de la Xerodermia Pigmentosa del Grupo D/genética , Adulto Joven
20.
Acta Haematol ; 124(2): 61-71, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20616541

RESUMEN

BACKGROUND: For those patients who are not candidates for allogeneic stem cell transplantation (SCT) or who do not have an HLA-matched donor, it is unclear whether consolidation therapy with autologous SCT results in a survival benefit compared with further intensive post-remission non-myeloablative chemotherapy or no further therapy. METHODS: A meta-analysis evaluating autologous SCT versus further chemotherapy or no treatment for acute myeloid leukemia (AML) in first complete remission (CR1) was completed. The search used the following combined search terms in Medline, Embase, the Cochrane Controlled Trials Register, the Cochrane Library, the Web of Science and the China National Knowledge Infrastructure. RESULTS: Overall, 13 studies of 12 randomized controlled trials were identified. Four studies were in pediatric patients and 9 were in adults. For adults, AML in CR1 compared with non-SCT, lower relapse and higher transplantation-related mortality were associated with autologous SCT, a significant disease-free survival benefit of autologous SCT was documented, and there was no difference in overall survival when studies were pooled. For pediatric AML in CR1, there were no differences in relapse, transplantation-related mortality, disease-free survival and overall survival. Significantly less survival from relapse impairment was found for autologous SCT. CONCLUSION: Our results support the conclusion that autologous SCT should not be considered as the first-line post-remission therapy for AML patients in CR1.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/mortalidad , Trasplante de Células Madre Hematopoyéticas/estadística & datos numéricos , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/terapia , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Inducción de Remisión , Factores de Riesgo , Prevención Secundaria , Trasplante Autólogo
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