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1.
J Am Chem Soc ; 145(42): 22890-22895, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37845783

RESUMO

The first deoxygenative Heck reactions are described, as illustrated by formate-mediated cine-substitutions of vinyl triflates with aryl iodides. The collective data corroborate a mechanism in which Pd(OAc)2 and Bu4NI form the dianionic iodide-bridged dimer [Pd2I6][NBu4]2, which, under reducing conditions, serves as a precursor to the palladium(I) complex [Pd2I4][NBu4]2. Dinculear oxidative addition of aryl iodide forms [Pd2I5(Ar)][NBu4]2, which dissociates to the monometallic complex [PdI2(Ar)][NBu4]. Vinyl triflate migratory insertion-sulfonate elimination delivers a palladium(IV) carbene, which upon ß-hydride elimination/C-H reductive elimination gives the product of cine-substitution. These processes are the first efficient formate-mediated cross-electrophile reductive couplings beyond carbonyl addition.

2.
J Am Chem Soc ; 144(19): 8861-8869, 2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35503919

RESUMO

The first enantioselective ruthenium-catalyzed carbonyl vinylations via hydrogen autotransfer are described. Using a ruthenium-JOSIPHOS catalyst, primary alcohols 2a-2m and 2-butyne 1a are converted to chiral allylic alcohols 3a-3m with excellent levels of absolute stereocontrol. Notably, 1°,2°-1,3-diols participate in site-selective C-C coupling, enabling asymmetric carbonyl vinylation beyond premetalated reagents, exogenous reductants, or hydroxyl protecting groups. Using 2-propanol as a reductant, aldehydes dehydro-2a, 2l participate in highly enantioselective 2-butyne-mediated vinylation under otherwise identical reaction conditions. Regio-, stereo-, and site-selective vinylations mediated by 2-pentyne 1b to form adducts 3n, 3o, and epi-3o also are described. The tiglyl alcohol motif obtained upon butyne-mediated vinylation, which is itself found in diverse secondary metabolites, may be converted to commonly encountered polyketide stereodiads, -triads, and -tetrads, as demonstrated by the formation of adducts 4a-4d. The collective mechanistic studies, including deuterium labeling experiments, corroborate a catalytic cycle involving alcohol dehydrogenation to form a transient aldehyde and a ruthenium hydride, which engages in alkyne hydrometalation to form a nucleophilic vinylruthenium species that enacts carbonyl addition. A stereochemical model for carbonyl addition invoking formyl CH···I[Ru] and CH···O≡C[Ru] hydrogen bonds is proposed based on prior calculations and crystallographic data.


Assuntos
Rutênio , Álcoois/química , Aldeídos/química , Catálise , Hidrogênio/química , Rutênio/química , Estereoisomerismo
3.
J Formos Med Assoc ; 121(1 Pt 2): 350-359, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34154895

RESUMO

BACKGROUND: Patients with childhood cancer are at increased risk for the development of second cancers. METHODS: A national multicenter survey of second cancers conducted by the Taiwan Pediatric Oncology Group retrieved retrospective data from the database at the Children Cancer Foundation in Taiwan beginning in 1995. The characteristics of second cancers and associations of patient demographic and clinical characteristics with time to death due to a second cancer were analyzed. RESULTS: We examined the records of 8782 patients with a primary cancer diagnosed between January 1, 1995 and December 31, 2013, and a total of 99 patients with a second cancer were identified. The most common type of second cancer was acute myeloid leukemia (n = 35), followed by acute lymphoblastic leukemia (n = 15), central nervous system (CNS) tumors (n = 15), and sarcomas (n = 10). Secondary hematological malignancies occurred earlier than other secondary cancers. The frequencies of second CNS tumors and second bone cancers and sarcomas were notably increased when prior radiation doses increased from zero, low dose to high dose. The overall 5-year survival of patients with a second cancer was poor (33.7%). Multivariate survival analysis revealed that the year of primary diagnosis ≤2002, secondary hematological malignancies, and age at second cancer diagnosis ≤9.3 years or >26.8 years increased the risk of death following second cancer. CONCLUSION: Children who develop a second cancer have an unfavorable outcome. Early detection and improved treatment for second cancers are needed.


Assuntos
Segunda Neoplasia Primária , Neoplasias , Criança , Humanos , Neoplasias/epidemiologia , Segunda Neoplasia Primária/epidemiologia , Estudos Retrospectivos , Taiwan/epidemiologia
4.
J Am Chem Soc ; 143(40): 16709-16717, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34606271

RESUMO

Crystallographic characterization of RuX(CO)(η3-C3H5)(JOSIPHOS), where X = Cl, Br, or I, reveals a halide-dependent diastereomeric preference that defines metal-centered stereogenicity and, therefrom, the enantioselectivity of C-C coupling in ruthenium-catalyzed anti-diastereo- and enantioselective C-C couplings of primary alcohols with 1-aryl-1-propynes to form products of carbonyl anti-(α-aryl)allylation. Computational studies reveal that a non-classical hydrogen bond between iodide and the aldehyde formyl CH bond stabilizes the favored transition state for carbonyl addition. An improved catalytic system enabling previously unattainable transformations was developed that employs an iodide-containing precatalyst, RuI(CO)3(η3-C3H5), in combination with trifluoroethanol, as illustrated by the first enantioselective ruthenium-catalyzed C-C couplings of ethanol to form higher alcohols.


Assuntos
Álcoois
5.
Cancer ; 124(23): 4538-4547, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30303520

RESUMO

BACKGROUND: To eliminate cranial irradiation (CrRT)-related sequelae and to minimize the adverse impact of traumatic lumbar puncture (TLP) with blasts, the Taiwan Pediatric Oncology Group (TPOG) introduced a modified central nervous system (CNS)-directed regimen characterized by delayed triple intrathecal therapy (TIT) and the omission of CrRT for all children with newly diagnosed acute lymphoblastic leukemia (ALL). METHODS: This study compared the treatment outcomes of patients overall and patients with a non-CNS-1 status (CNS-2, CNS-3, or TLP with blasts) in 2 treatment eras, one before and another after the revision of the TPOG-ALL-2002 protocol by the introduction of the modification (era 1 [2002-2008] with CrRT and era 2 [2009-2012] with delayed first TIT and no CrRT). RESULTS: There were no statistically significant differences in major outcomes between the 903 patients treated in era 1 and the 444 patients treated in era 2: the 5-year event-free survival (EFS) rates were 75.7% ± 1.4% and 72.1% ± 2.4%, respectively (P = .260), and the cumulative risks of isolated CNS relapse were 4.0% ± 0.7% and 4.1% ± 1.0%, respectively (P = .960). There were also no differences between non-CNS-1 patients treated in era 1 (n = 76) and era 2 (n =28): the 5-year EFS rates were 52.3% ± 5.8% and 62.9% ± 9.4%, respectively (P = .199), and the cumulative risks of isolated CNS relapse were 6.3% ± 3.1% and 3.6% ± 3.5%, respectively (P = .639). Notably, TLP with blasts was completely eliminated after the first TIT was delayed in era 2. CONCLUSIONS: The delay of the first TIT until the clearance of circulating blasts and the total omission of CrRT did not compromise survival or CNS control in patients with childhood ALL, including those with a non-CNS-1 status.


Assuntos
Antineoplásicos/administração & dosagem , Irradiação Craniana/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Antineoplásicos/uso terapêutico , Neoplasias do Sistema Nervoso Central , Criança , Pré-Escolar , Irradiação Craniana/efeitos adversos , Feminino , Humanos , Lactente , Recém-Nascido , Injeções Espinhais , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/radioterapia , Análise de Sobrevida , Tempo para o Tratamento , Resultado do Tratamento
6.
Nutr Cancer ; 69(5): 746-751, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28569624

RESUMO

High-dose methotrexate (HDMTX) is important for children with acute lymphoblastic leukemia (ALL). There is no effective treatment for patients with oral mucositis, which is a major side effect associated with HDMTX. Here, we reviewed the medical records of patients younger than 18 yr with newly diagnosed ALL in our hospitals from 2002 to 2013. According to the nationwide protocol (TPOG-ALL-2002), each patient received four courses of HDMTX (2.5 or 5 g/m2) during consolidation therapy. HDMTX courses with glutamine therapy were as the glutamine group, and intravenous glutamine (0.4 g/kg/day) was started within 48 h after the initiation of HDMTX for 3 consecutive days. HDMTX courses without glutamine were as the control group. A total of 347 HDMTX courses were administrated in the 96 children with ALL during the study period. The incidence of oral mucositis was significantly lower in the glutamine group than in the control group (3.8% vs. 17.6%; P = 0.004). In the glutamine group, no patients suffered from severe oral mucositis. No severe adverse effects associated with glutamine administration were noted. Accordingly, parenteral glutamine appears to be feasible and safe to prevent oral mucositis in patients receiving HDMTX.


Assuntos
Glutamina/farmacologia , Metotrexato/efeitos adversos , Nutrição Parenteral/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Estomatite/induzido quimicamente , Adolescente , Antimetabólitos Antineoplásicos/efeitos adversos , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos , Estomatite/prevenção & controle
7.
Pediatr Blood Cancer ; 64(2): 234-241, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27696656

RESUMO

BACKGROUND: Reinduction therapy has improved the outcomes in children with acute lymphoblastic leukemia (ALL). We sought to determine the optimal course(s) of reinduction therapy for standard-risk (SR, or "low-risk" in other groups) patients. Also, we evaluated outcomes using triple intrathecal therapy without cranial radiation (CrRT) for central nervous system (CNS) preventive therapy. PROCEDURE: From 2002 to 2012, all newly diagnosed children with ALL in Taiwan were enrolled in Taiwan Pediatric Oncology Group ALL-2002 protocol. SR patients were randomized to receive single or double reinduction courses. The patients enrolled before 2009 received CrRT, while those enrolled later did not. The Kaplan-Meier method was used to estimate survival rates and the difference between two groups was compared by the two-sided log-rank test. RESULTS: In 1,366 eligible patients, the 5-year overall survival (OS) was 81.6 ± 1.1% (standard error) and 5-year event-free survival (EFS) was 74.3 ± 1.2%. In SR patients, the 5-year OS for one and two reinduction courses was 91.6 ± 2.1% and 93.7 ± 1.8%, respectively, and the 5-year EFS was 85.2 ± 2.7% and 89.8 ± 2.3%, respectively. There were no significant differences in survival between these two groups. Patients with MLL or BCR-ABL1 had the worst outcomes: 5-year EFS was 23.4 and 31.8% and 5-year OS was 28.6 and 44.7%, respectively. There was no significant difference in CNS relapse or survival between the era with or without CrRT. CONCLUSIONS: For SR patients, one-course reinduction was adequate. Triple intrathecal therapy alone successfully prevented CNS relapse.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Sistema Nervoso Central/prevenção & controle , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Criança , Pré-Escolar , Terapia Combinada , Irradiação Craniana , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
8.
Pediatr Blood Cancer ; 64(10)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28436581

RESUMO

BACKGROUND: In childhood acute lymphoblastic leukemia (ALL), t(1;19)(q23;p13.3) with TCF3-PBX1 fusion is one of the most frequent translocations. Historically, it has been associated with poor prognosis. Intensive treatment, however, has improved its outcome. We determined the outcome of children with this genotype treated with contemporary intensive chemotherapy in Taiwan. PROCEDURE: In Taiwan Pediatric Oncology Group 2002 ALL studies, genotypes were determined by cytogenetic analysis and/or reverse transcriptase polymerase chain reaction assay. Based on presenting features, immunophenotype and genotype, patients were assigned to one of the three risk groups: standard risk (SR), high risk (HR), or very high risk (VHR). The patients with t(1;19)/TCF3-PBX1 were treated in the HR arm receiving more intensive chemotherapy. The outcomes of patients with t(1;19)/TCF3-PBX1 were compared to that of patients with other subtypes of B-precursor ALL (B-ALL). RESULTS: Of the 1,129 patients with B-ALL, 64 (5.7%) had t(1;19)/TCF3-PBX1; 51 of whom were treated in the HR arm, but 11 were treated in the VHR and 2 in the SR arm because of physician's preference. As a group, 64 patients with t(1;19)/TCF3-PBX1 had similar 5-year event-free survival (83.3 ± 4.8%) as those with TEL-AML1 (85.2 ± 3.4%, P = 0.984) or those with hyperdiploidy >50 (84.0 ± 3.1%, P = 0.748). The cumulative risk of any (isolated plus combined) central nervous system relapse among patients with t(1;19)/TCF3-PBX1 (8.7 ± 3.8%) tended to be higher than that of patients with TEL-AML1 (5.8 ± 2.3%, P = 0.749) or those with hyperdiploidy (4.1 ± 1.8%, P = 0.135), albeit the differences did not reach statistical significance. CONCLUSIONS: With contemporary intensive chemotherapy, children with t(1;19)/TCF3-PBX1 fared as well as those with favorable genotypes (TEL-AML1 or hyperdiploidy).


Assuntos
Cromossomos Humanos Par 19 , Cromossomos Humanos Par 1 , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Translocação Genética , Adolescente , Criança , Pré-Escolar , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 1/metabolismo , Cromossomos Humanos Par 19/genética , Cromossomos Humanos Par 19/metabolismo , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Taiwan
9.
Pediatr Blood Cancer ; 63(4): 665-70, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26703788

RESUMO

BACKGROUND: Discontinuation of E. coli l-asparaginase in patients with acute lymphoblastic leukemia (ALL) is unavoidable upon severe allergic reaction. We sought to examine outcomes following E. coli l-asparaginase discontinuation due to severe allergic reactions. PROCEDURE: We evaluated the outcome of children enrolled in Taiwan Pediatric Oncology Group-2002-ALL protocol between 2002 and 2012, who had E. coli l-asparaginase discontinued due to severe allergic reactions, and compared the outcomes of those who continued with Erwinia l-asparaginase (Erwinase) with those who did not. RESULTS: Among 700 patients enrolled in this study, 33 patients had E. coli l-asparaginase treatment discontinued due to severe allergic reactions. Five-year overall survival did not differ significantly among the 648 patients without discontinuation (81 ± 1.6%, mean ± SE), compared to 17 patients with allergic reactions and treated with Erwinase (88 ± 7.8%) and 16 patients with allergic reactions but not treated with Erwinase (87 ± 8.6%). Among 16 patients who did not receive Erwinase, all 10 who received ≥50% of the scheduled doses of E. coli l-asparaginase before discontinuation survived without events. CONCLUSIONS: Erwinase treatment may not be needed for some ALL patients with severe allergy to E. coli l-asparaginase if ≥50% of prescribed doses were received and/or therapy is augmented with other agents.


Assuntos
Antineoplásicos/efeitos adversos , Asparaginase/efeitos adversos , Hipersensibilidade a Drogas , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Criança , Pré-Escolar , Intervalo Livre de Doença , Escherichia coli , Feminino , Humanos , Lactente , Estimativa de Kaplan-Meier , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade
10.
Forensic Sci Int ; 361: 112134, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38996540

RESUMO

Synthetic cathinones are some of the most prevalent new psychoactive substances (NPSs) globally, with alpha-pyrrolidinoisohexanophenone (α-PiHP) being particularly noted for its widespread use in the United States, Europe, and Taiwan. However, the analysis of isomeric NPSs such as α-PiHP and alpha-pyrrolidinohexiophenone (α-PHP) is challenging owing to similarities in their retention times and mass spectra. This study proposes a dual strategy based on in vitro metabolic experiments and machine learning-based classification modelling for differentiating α-PHP and α-PiHP in urine samples: (1) in vitro metabolic experiments using pooled human liver microsomes and liquid chromatography tandem quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) were conducted to identify the key metabolites of α-PHP and α-PiHP from the high-resolution MS/MS spectra. After 5 h incubation, 71.4 % of α-PHP and 64.7 % of α-PiHP remained unmetabolised. Nine phase I metabolites were identified for each compound, including primary ß-ketone reduction (M1) metabolites. Comparing the metabolites and retention times confirmed the efficacy of in vitro metabolic experiments for differentiating NPS isomers. Subsequently, analysis of seven real urine samples revealed the presence for various metabolites, including M1, that could be used as suitable detection markers at low concentrations. The aliphatic hydroxylation (M2) metabolite peak counts and metabolite retention times were used to determine α-PiHP use. (2) Classification models for the parent compounds and M1 metabolites were developed using principal component analysis for feature extraction and logistic regression for classification. The training and test sets were devised from the spectra of standard samples or supernatants from in vitro metabolism experiments with different incubation times. Both models had classification accuracies of 100 % and accurately identified α-PiHP and its M1 metabolite in seven real urine samples. The proposed methodology effectively distinguished between such isomers and confirmed their presence at low concentrations. Overall, this study introduces a novel concept that addresses the complexities in analysing isomeric NPSs and suggests a path towards enhancing the accuracy and reliability of NPS detection.


Assuntos
Aprendizado de Máquina , Microssomos Hepáticos , Pirrolidinas , Humanos , Microssomos Hepáticos/metabolismo , Pirrolidinas/urina , Cromatografia Líquida , Psicotrópicos/urina , Psicotrópicos/metabolismo , Espectrometria de Massas em Tandem , Espectrometria de Massas/métodos , Isomerismo , Técnicas In Vitro , Alcaloides/urina , Alcaloides/metabolismo
11.
Aging (Albany NY) ; 16(14): 11409-11433, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39033780

RESUMO

Target antigens are crucial for developing chimeric antigen receptor (CAR)-T cells, but their application to ovarian cancers is limited. This study aimed to identify potential genes as CAR-T-cell antigen candidates for ovarian cancers. A differential gene expression analysis was performed on ovarian cancer samples from four datasets obtained from the GEO datasets. Functional annotation, pathway analysis, protein localization, and gene expression analysis were conducted using various datasets and tools. An oncogenicity analysis and network analysis were also performed. In total, 153 differentially expressed genes were identified in ovarian cancer samples, with 60 differentially expressed genes expressing plasma membrane proteins suitable for CAR-T-cell antigens. Among them, 21 plasma membrane proteins were predicted to be oncogenes in ovarian cancers, with nine proteins playing crucial roles in the network. Key genes identified in the oncogenic pathways of ovarian cancers included MUC1, CXCR4, EPCAM, RACGAP1, UBE2C, PRAME, SORT1, JUP, and CLDN3, suggesting them as recommended antigens for CAR-T-cell therapy for ovarian cancers. This study sheds light on potential targets for immunotherapy in ovarian cancers.


Assuntos
Biologia Computacional , Imunoterapia Adotiva , Neoplasias Ovarianas , Receptores de Antígenos Quiméricos , Feminino , Humanos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/terapia , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/imunologia , Imunoterapia Adotiva/métodos , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/metabolismo , Regulação Neoplásica da Expressão Gênica , Perfilação da Expressão Gênica
12.
Adv Pharm Bull ; 14(2): 314-330, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39206402

RESUMO

Purpose: Lymphoma, the most predominant neoplastic disorder, is divided into Hodgkin and Non-Hodgkin Lymphoma classifications. Immunotherapeutic modalities have emerged as essential methodologies in combating lymphoid malignancies. Chimeric Antigen Receptor (CAR) T cells exhibit promising responses in chemotherapy-resistant B-cell non-Hodgkin lymphoma cases. Methods: This comprehensive review delineates the advancement of CAR-T cell therapy as an immunotherapeutic instrument, the selection of lymphoma antigens for CAR-T cell targeting, and the conceptualization, synthesis, and deployment of CAR-T cells. Furthermore, it encompasses the advantages and disadvantages of CAR-T cell therapy and the prospective horizons of CAR-T cells from a computational research perspective. In order to improve the design and functionality of artificial CARs, there is a need for TCR recognition investigation, followed by the implementation of a quality surveillance methodology. Results: Various lymphoma antigens are amenable to CAR-T cell targeting, such as CD19, CD20, CD22, CD30, the kappa light chain, and ROR1. A notable merit of CAR-T cell therapy is the augmentation of the immune system's capacity to generate tumoricidal activity in patients exhibiting chemotherapy-resistant lymphoma. Nevertheless, it also introduces manufacturing impediments that are laborious, technologically demanding, and financially burdensome. Physical, physicochemical, and physiological limitations further exacerbate the challenge of treating solid neoplasms with CAR-T cells. Conclusion: While the efficacy and safety of CAR-T cell immunotherapy remain subjects of fervent investigation, the promise of this cutting-edge technology offers valuable insights for the future evolution of lymphoma treatment management approaches. Moreover, CAR-T cell therapies potentially benefit patients, motivating regulatory bodies to foster international collaboration.

13.
Biomedicines ; 11(10)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37893141

RESUMO

Osteosarcoma is a common malignant tumor in children and adolescents, known for its aggressive invasion and distant metastasis, leading to a poor prognosis. Matrix metalloproteinases (MMPs) can degrade the extracellular matrix and basement membranes through their proteolytic activity, thereby promoting osteosarcoma metastasis. Chemokine ligand 2 (CCL2) is a well-studied chemokine that plays a significant role in the cell motility of many cancers. However, its specific involvement in osteosarcoma metastasis is not fully understood. The aim of this study is to examine the role of miRNAs in CCL2-mediated MMP expression and cell motility in human osteosarcoma. The analysis of immunohistochemistry data and databases associated a positive correlation between CCL2 or MMP-3 levels with the metastasis of osteosarcoma patients. The in vivo lung metastatic osteosarcoma model also demonstrated similar effects, showing higher levels of CCL2 and MMP-3 in lung metastatic osteosarcoma tissues. The stimulation of osteosarcoma cells with CCL2 enhanced migration and invasion abilities through the upregulation of MMP-3 synthesis. Our results also indicate that CCL2 enhances MMP-3-dependent cell motility by inhibiting miR-3659 synthesis. Therefore, CCL2 represents a promising therapeutic target for treating metastasis in osteosarcoma.

14.
Discov Nano ; 18(1): 29, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36862206

RESUMO

Though light-emitting diodes (LEDs) combined with various color conversion techniques have been widely explored for VLC (visible light communication), E-O (electro-optical) frequency responses of devices with quantum dots (QDs) embedded within the nanoholes have rarely been addressed. Here we propose LEDs with embedded photonic crystal (PhC) nanohole patterns and green light QDs for studying small-signal E-O frequency bandwidths and large signal on-off keying E-O responses. We observe that the E-O modulation quality of PhC LEDs with QDs is better than a conventional LED with QDs when the overall blue mixed with green light output signal is considered. However, the optical response of only QD converted green light shows a contradictory result. The slower E-O conversion response is attributed to multi-path green light generation from both radiative and nonradiative energy transfer processes for QDs coated on the PhC LEDs.

15.
ACS Catal ; 12(14): 8164-8174, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37082110

RESUMO

The use of alkynes as vinylmetal pronucleophiles in intermolecular enantioselective metal-catalyzed carbonyl and imine reductive couplings to form allylic alcohols and amines is surveyed. Related hydrogen auto-transfer processes, wherein alcohols or amines serve dually as reductants and carbonyl or imine proelectrophiles, also are cataloged, as are applications in target-oriented synthesis. These processes represent an emerging alternative to the use of stoichiometric vinylmetal reagents or Nozaki-Hiyama-Kishi (NHK) reactions in carbonyl and imine alkenylation.

16.
ACS Appl Mater Interfaces ; 14(3): 3849-3863, 2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35019259

RESUMO

Nitric oxide (NO) is an endogenous gasotransmitter regulating alternative physiological processes in the cardiovascular system. To achieve translational application of NO, continued efforts are made on the development of orally active NO prodrugs for long-term treatment of chronic cardiovascular diseases. Herein, immobilization of NO-delivery [Fe2(µ-SCH2CH2COOH)2(NO)4] (DNIC-2) onto MIL-88B, a metal-organic framework (MOF) consisting of biocompatible Fe3+ and 1,4-benzenedicarboxylate (BDC), was performed to prepare a DNIC@MOF microrod for enhanced oral delivery of NO. In simulated gastric fluid, protonation of the BDC linker in DNIC@MOF initiates its transformation into a DNIC@tMOF microrod, which consisted of DNIC-2 well dispersed and confined within the BDC-based framework. Moreover, subsequent deprotonation of the BDC-based framework in DNIC@tMOF under simulated intestinal conditions promotes the release of DNIC-2 and NO. Of importance, this discovery of transformer-like DNIC@MOF provides a parallel insight into its stepwise transformation into DNIC@tMOF in the stomach followed by subsequent conversion into molecular DNIC-2 in the small intestine and release of NO in the bloodstream of mice. In comparison with acid-sensitive DNIC-2, oral administration of DNIC@MOF results in a 2.2-fold increase in the oral bioavailability of NO to 65.7% in mice and an effective reduction of systolic blood pressure (SBP) to a ΔSBP of 60.9 ± 4.7 mmHg in spontaneously hypertensive rats for 12 h.


Assuntos
Materiais Biocompatíveis/farmacologia , Estruturas Metalorgânicas/farmacologia , Óxido Nítrico/química , Pró-Fármacos/farmacologia , Administração Oral , Animais , Materiais Biocompatíveis/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Eletrodos , Concentração de Íons de Hidrogênio , Teste de Materiais , Estruturas Metalorgânicas/administração & dosagem , Camundongos , Óxido Nítrico/administração & dosagem , Tamanho da Partícula , Pró-Fármacos/química , Propriedades de Superfície
17.
ACS Appl Mater Interfaces ; 13(40): 47465-47477, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34592812

RESUMO

Regarding dihydrogen as a clean and renewable energy source, ammonia borane (NH3BH3, AB) was considered as a chemical H2-storage and H2-delivery material due to its high storage capacity of dihydrogen (19.6 wt %) and stability at room temperature. To advance the development of efficient and recyclable catalysts for hydrolytic dehydrogenation of AB with parallel insight into the reaction mechanism, herein, ZIF-67-derived fcc-Co@porous carbon nano/microparticles (cZIF-67_nm/cZIF-67_µm) were explored to promote catalytic dehydrogenation of AB and generation of H2(g). According to kinetic and computational studies, zero-order dependence on the concentration of AB, first-order dependence on the concentration of cZIF-67_nm (or cZIF-67_µm), and a kinetic isotope effect value of 2.45 (or 2.64) for H2O/D2O identify the Co-catalyzed cleavage of the H-OH bond, instead of the H-BH2NH3 bond, as the rate-determining step in the hydrolytic dehydrogenation of AB. Despite the absent evolution of H2(g) in the reaction of cZIF-67 and AB in the organic solvents (i.e., THF or CH3OH) or in the reaction of cZIF-67 and water, Co-mediated activation of AB and formation of a Co-H intermediate were evidenced by theoretical calculation, infrared spectroscopy in combination with an isotope-labeling experiment, and reactivity study toward CO2-to-formate/H2O-to-H2 conversion. Moreover, the computational study discovers a synergistic interaction between AB and the water cluster (H2O)9 on fcc-Co, which shifts the splitting of water into an exergonic process and lowers the thermodynamic barrier for the generation and desorption of H2(g) from the Co-H intermediates. With the kinetic and mechanistic study of ZIF-67-derived Co@porous carbon for catalytic hydrolysis of AB, the spatiotemporal control on the generation of H2(g) for the treatment of inflammatory diseases will be further investigated in the near future.

18.
JACS Au ; 1(7): 998-1013, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34467346

RESUMO

Nitric oxide (NO), a pro-neurogenic and antineuroinflammatory gasotransmitter, features the potential to develop a translational medicine against neuropathological conditions. Despite the extensive efforts made on the controlled delivery of therapeutic NO, however, an orally active NO prodrug for a treatment of chronic neuropathy was not reported yet. Inspired by the natural dinitrosyl iron unit (DNIU) [Fe(NO)2], in this study, a reversible and dynamic interaction between the biomimetic [(NO)2Fe(µ-SCH2CH2OH)2Fe(NO)2] (DNIC-1) and serum albumin (or gastrointestinal mucin) was explored to discover endogenous proteins as a vehicle for an oral delivery of NO to the brain after an oral administration of DNIC-1. On the basis of the in vitro and in vivo study, a rapid binding of DNIC-1 toward gastrointestinal mucin yielding the mucin-bound dinitrosyl iron complex (DNIC) discovers the mucoadhesive nature of DNIC-1. A reversible interconversion between mucin-bound DNIC and DNIC-1 facilitates the mucus-penetrating migration of DNIC-1 shielded in the gastrointestinal tract of the stomach and small intestine. Moreover, the NO-release reactivity of DNIC-1 induces the transient opening of the cellular tight junction and enhances its paracellular permeability across the intestinal epithelial barrier. During circulation in the bloodstream, a stoichiometric binding of DNIC-1 to the serum albumin, as another endogenous protein vehicle, stabilizes the DNIU [Fe(NO)2] for a subsequent transfer into the brain. With aging mice under a Western diet as a disease model for metabolic syndrome and cognitive impairment, an oral administration of DNIC-1 in a daily manner for 16 weeks activates the hippocampal neurogenesis and ameliorates the impaired cognitive ability. Taken together, these findings disclose the synergy between biomimetic DNIC-1 and endogenous protein vehicles for an oral delivery of therapeutic NO to the brain against chronic neuropathy.

19.
Sci Rep ; 11(1): 5893, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33723338

RESUMO

Improvement in outcomes of children with acute myeloid leukemia (AML) is attributed to several refinements in clinical management. We evaluated treatment outcomes of Taiwanese pediatric AML patients in the past 20 years. Overall, 860 de novo AML patients aged 0-18 years and registered in the Childhood Cancer Foundation of R.O.C during January 1996-December 2019 were included. Survival analysis was performed to identify factors that improved treatment outcomes. Regardless of treatment modalities used, patients during 2008-2019 had better 5-year event-free survival (EFS) and overall survival (OS) rates than patients during 1996-2007. For patients received the TPOG-AML-97A treatment, only 5-year OS rates were significantly different between patients diagnosed before and after 2008. Patients with RUNX1-RUNX1T1 had similar relapse-free survival rates, but 5-year OS rates were better during 2008-2019. However, the survival of patients who received hematopoietic stem-cell transplantations (HSCT) did not differ significantly before and after 2008. For patients without relapse, the 5-year OS improved during 2008-2019. Non-relapse mortality decreased annually, and cumulative relapse rates were similar. In conclusion, 5-year EFS and OS rates improved during 2008-2019, though intensities of chemotherapy treatments were similar before and after 2008. Non-relapse mortality decreased gradually. Further treatment strategies including more intensive chemotherapy, novel agents' use, identification of high-risk patients using genotyping and minimal residual disease, early intervention of HSCT, and antibiotic prophylaxis can be considered for future clinical protocol designs in Taiwan.


Assuntos
Leucemia Mieloide Aguda/tratamento farmacológico , Adolescente , Antineoplásicos/uso terapêutico , Criança , Pré-Escolar , Análise Citogenética , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Incidência , Lactente , Recém-Nascido , Leucemia Mieloide Aguda/genética , Masculino , Proteínas de Neoplasias/metabolismo , Recidiva Local de Neoplasia/patologia , Intervalo Livre de Progressão , Estudos Retrospectivos , Taiwan , Fatores de Tempo , Resultado do Tratamento
20.
Urol Case Rep ; 33: 101366, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33102065

RESUMO

Testicular epidermoid cyst (TEC) is an uncommon benign testicular lesion that can be successfully cured via lesion enucleation and at the same time preserving patient's fertility. Doppler ultrasound (US), contrast-enhanced MRI and tumor markers are helpful in the diagnosis of TEC if the lesion does not show typical characteristics such as onion skin and target appearance. Herein, we report a case of TEC without typical structural characteristics but heterogeneously mixed echogenic content in US examination, no internal vascularity in the color Doppler study and lack of contrast enhancement in MRI images. These additional findings are helpful for diagnosing TEC.

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