Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Anal Bioanal Chem ; 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38459966

RESUMO

The high catalytic activity of Cu-based nanozymes mainly depends on the efficient Fenton-like reaction of Cu+/ H2O2, but Cu+ cannot exist stably. Trying to find a material that can stably support Cu+ while promoting the electron cycle of Cu2+/Cu+ still faces serious challenges. C60 is expected to be an ideal candidate to solve this problem due to its unique structure and rich physicochemical properties. Here, we designed and synthesized a C60-doped Cu+-based nanozyme (termed as C60-Cu-Bpy) by loading high catalytic active site Cu+ onto C60 and coordinating with 2,2'-bipyridine (Bpy). The single crystal diffraction analysis and a series of auxiliary characterization technologies were used to demonstrate the successful preparation of C60-Cu-Bpy. Significantly, the C60-Cu-Bpy exhibited superior peroxidase-like activity during the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). Then, the catalytic mechanism of C60-Cu-Bpy as peroxidase was elucidated in detail, mainly benefiting from the dual function of C60. On the one hand, C60 acted as a carrier to directly support Cu+, which has the ability to efficiently decompose H2O2 to produce reactive oxygen species. The other was that C60 acted as an electron buffer, contributing to promoting the Cu2+/Cu+ cycle to facilitate the reaction. Furthermore, a colorimetric sensor for the quantitative analysis of bleomycin was established based on the principle of bleomycin specific inhibition of C60-Cu-Bpy peroxidase-like activity, with satisfactory results in practical samples. This study provides a new strategy for the direct synthesis of Cu+-based nanozymes with high catalytic performance.

2.
BMC Psychiatry ; 24(1): 452, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890607

RESUMO

BACKGROUND: Getting lost with family members who have dementia is a significant source of stress for family caregivers. In Taiwan, family caregivers develop strategies to deal with dementia persons who may get lost. This study aimed to explore the experiences of family caregivers caring for persons with dementia who have been lost outside the home. METHODS: A descriptive phenomenological method was used. The COREQ checklist was used to ensure the explicit reporting of data. A total of 20 family caregivers caring for persons with dementia who were lost outside their homes were selected from hospital outpatient clinics and a day care center in northern Taiwan using purposive sampling. Data were analyzed using the Giorgi analysis method. RESULTS: Five main themes emerged: (i) surprised persons with dementia lost outside, (ii) using strategies to prevent persons with dementia from getting lost, (iii) using strategies to find lost persons with dementia, (iv) exhaustion in long-term care persons with dementia, and (v) coping with the care load. It was found that family caregivers were surprised, nervous, and worried about persons with dementia being lost outside. They used the first strategy to supervise persons with dementia to prevent external losses. In addition, long-term supervision of persons with dementia led to mental exhaustion in the family caregivers. Finally, the family caregivers learned about loss prevention strategies and obtained family support and care replacement workers to reduce the care burden. CONCLUSIONS: It is essential to teach family caregivers early to prevent persons with dementia from losing external strategies. Nurses also provide long-term care services to reduce the care burden on family caregivers.


Assuntos
Adaptação Psicológica , Cuidadores , Demência , Pesquisa Qualitativa , Humanos , Cuidadores/psicologia , Demência/enfermagem , Demência/psicologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Taiwan , Família/psicologia , Adulto , Estresse Psicológico/psicologia , Idoso de 80 Anos ou mais
3.
Angew Chem Int Ed Engl ; 62(34): e202305357, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37313642

RESUMO

Pristine fullerene C60 is an excellent electron transport material for state-of-the-art inverted structure perovskite solar cells (PSCs), but its low solubility leaves thermal evaporation as the only method for depositing it into a high-quality electron transport layer (ETL). To address this problem, we herein introduce a highly soluble bowl-shaped additive, corannulene, to assist in C60 -assembly into a smooth and compact film through the favorable bowl-ball interaction. Our results show that not only corannulene can dramatically enhance the film formability of C60 , it also plays a critical role in forming C60 -corannulene (CC) supramolecular species and in boosting intermolecular electron transport dynamics in the ETL. This strategy has allowed CC devices to deliver high power conversion efficiencies up to 21.69 %, which is the highest value among the PSCs based on the solution-processed-C60 (SP-C60 ) ETL. Moreover, the stability of the CC device is far superior to that of the C60 -only device because corannulene can retard and curb the spontaneous aggregation of C60 . This work establishes the bowl-assisted ball assembly strategy for developing low-cost and efficient SP-C60 ETLs with high promise for fully-SP PSCs.

4.
Anticancer Drugs ; 33(7): 686-690, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35324515

RESUMO

Thymic lymphoepithelioma-like carcinoma (LELC) is a rare primary malignant neoplasm originating from the thymus. Thymic LELC diagnosis is often terminal when diagnosed, some patients have lost the opportunity for surgery. Platinum- and anthracycline-based systemic chemotherapy are the first-line treatment plan; however, there is no clear consensus on therapy when first-line treatment fails because of the lack of cases of advanced thymic LELC. Here was a rare case of advanced thymic LELC with bone marrow metastasis at relapse, which is reported in a patient who responded well to toripalimab combined with anlotinib therapy. The treatment showed tolerable toxicity with good antitumor activity in the patient. As far as we know, this is the first case that the combination of toripalimab with anlotinib is effective in controlling advanced thymic LELC with bone marrow metastasis. The case reports represent an essential means by which an effective therapy for advanced thymic LELC may not be practical given the low frequency of a thymic LELC with multiple metastases.


Assuntos
Neoplasias da Medula Óssea , Neoplasias Ósseas , Carcinoma de Células Escamosas , Humanos , Imunoterapia , Platina
5.
Acta Pharmacol Sin ; 41(11): 1416-1426, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32973325

RESUMO

Immunotherapies for cancers may cause severe and life-threatening cardiotoxicities. The underlying mechanisms are complex and largely elusive. Currently, there are several ongoing clinical trials based on the use of activated invariant natural killer T (iNKT) cells. The potential cardiotoxicity commonly associated with this particular immunotherapy has yet been carefully evaluated. The present study aims to determine the effect of activated iNKT cells on normal and ß-adrenergic agonist (isoproterenol, ISO)-stimulated hearts. Mice were treated with iNKT stimulants, α-galactosylceramide (αGC) or its analog OCH, respectively, to determine their effect on ISO-induced cardiac injury. We showed that administration of αGC (activating both T helper type 1 (Th1)- and T helper type 2 (Th2)-liked iNKT cells) significantly accelerated the progressive cardiac injury, leading to enhanced cardiac hypertrophy and cardiac fibrosis with prominent increases in collagen deposition and TGF-ß1, IL-6, and alpha smooth muscle actin expression. In contrast to αGC, OCH (mainly activating Th2-liked iNKT cells) significantly attenuated the progression of cardiac injury and cardiac inflammation induced by repeated infusion of ISO. Flow cytometry analysis revealed that αGC promoted inflammatory macrophage infiltration in the heart, while OCH was able to restrain the infiltration. In vitro coculture of αGC- or OCH-pretreated primary peritoneal macrophages with primary cardiac fibroblasts confirmed the profibrotic effect of αGC and the antifibrotic effect of OCH. Our results demonstrate that activating both Th1- and Th2-liked iNKT cells is cardiotoxic, while activating Th2-liked iNKT cells is likely cardiac protective, which has implied key differences among subpopulations of iNKT cells in their response to cardiac pathological stimulation.


Assuntos
Cardiomegalia/etiologia , Cardiotônicos/uso terapêutico , Galactosilceramidas/efeitos adversos , Glicolipídeos/uso terapêutico , Ativação Linfocitária/efeitos dos fármacos , Células T Matadoras Naturais/efeitos dos fármacos , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/tratamento farmacológico , Cardiomegalia/patologia , Citocinas/metabolismo , Fibrose , Inflamação/prevenção & controle , Isoproterenol , Macrófagos/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Células T Matadoras Naturais/classificação
6.
Zhongguo Zhong Yao Za Zhi ; 45(11): 2546-2551, 2020 Jun.
Artigo em Zh | MEDLINE | ID: mdl-32627487

RESUMO

The present study was aimed to investigate the effect of lime and licorice processing of Pinelliae Rhizoma on its toxic lectin protein and clarify the scientific detoxification connotation of lime and licorice processing of Pinelliae Rhizoma. Western blot was used to semi-quantitatively analyze the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum. Raw products and lectin were treated by soaking in licorice juice, lime solution or mixture solution of these two to investigate the different processing time on the content of toxic lectin protein. SDS-PAGE gel electrophoresis was used to analyze the changes of lectin protein bands in the solution and precipitates before and after processing. MALDI-TOF technology was used to qualitatively analyze and compare the protein molecular weight before and after processing. The results showed that the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum were 5.01% and 0.04% respectively, indicating that processing could significantly reduce the content of active lectin in raw products. The results also showed that the content of lectin in raw drugs decreased significantly after soaking in lime solution for one day or in licorice juice for three day, and the effect was greatest in mixture solution. Qualitative analysis showed that after being treated by soaking in lime solution, the lectin protein was decomposed into small peptide segments, while after being treated by soaking in licorice juice, the lectin protein was denatured and precipitated. The structure of lectin protein in Pinelliae Rhizoma was broken after being processed with licorice juice and lime solution, which significantly reduced the content of toxic lectinprotein. This is one of the detoxification mechanisms of Pinelliae Rhizoma processing.


Assuntos
Medicamentos de Ervas Chinesas , Glycyrrhiza , Pinellia , Compostos de Cálcio , Lectinas , Óxidos , Tecnologia Farmacêutica
7.
J Am Chem Soc ; 141(16): 6651-6657, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30879294

RESUMO

The combustion has long been applied for industrial synthesis of carbon materials such as fullerenes as well as carbon particles (known as carbon black), but the components and structures of the carbon soot are far from being clarified. Herein, we retrieve an unprecedented hydrofullerene C66H4 from a soot of a low-pressure combustion of benzene-acetylene-oxygen. Unambiguously characterized by single-crystal X-ray diffraction, the C66H4 renders a nonclassical geometry incorporating two heptagons and two pairs of fused pentagons in a C2 v symmetry. The common vertexes of the fused pentagons are bonded with four hydrogen atoms to convert the hydrogen-linking carbon atoms from sp2 to sp3 hybridization, which together with the adjacent heptagons essentially releases the sp2-bond strains on the abutting-pentagon sites of the diheptagonal fused pentagon C66 (dihept-C66). DFT computations suggest the possibility for an in situ hydrogenation process leading to stabilization of the dihept-C66. In addition, the experiments have been carried out to study heptagon-dependent properties of dihept-C66H4, indicating the key responsibility of the heptagon for changing hydrocarbon activity and electronic properties. The present work with the unprecedented double-heptagon-containing hydrofullerene successfully isolated and identified as one of the low-pressure combustion products shows that the heptagon is a new building block for constructing fullerene products in addition to pentagons and hexagons in low-pressure combustion systems.

8.
J Org Chem ; 84(19): 12259-12267, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31315398

RESUMO

A general one-step synthesis of symmetrical or unsymmetrical 1,4-di(organo)fullerenes from organo(hydro)fullerenes (RC60H) is realized by direct oxidative arylation. The new combination of catalytic trifluoromethanesulfonic acid (TfOH) and stoichiometric o-chloranil is the first to be used to directly generate an R-C60+ intermediate from common RC60H. Unexpectedly, the in situ generated R-C60+ intermediate is shown to be quite stable in whole 13C NMR spectroscopy characterization in the absence of cation quenching reagents. Because the direct oxidation of common RC60H to form the corresponding R-C60+ has never been realized, the present combination of TfOH and o-chloranil solves the challenges associated with the formation of stable RC60+ cations from common RC60H without any coordination of an R group.

9.
Zhongguo Zhong Yao Za Zhi ; 44(24): 5398-5404, 2019 Dec.
Artigo em Zh | MEDLINE | ID: mdl-32237386

RESUMO

The study aimed to investigate the effect of processing on lectin protein in four toxic Chinese medicines tubers of Pinellia ternata,P. pedatisecta,Arisema heterophyllum and Typhonium giganteum. Western blot was used to semi-quantitatively analyze the content of lectin in the four kinds of toxic Chinese medicines and their different processed products. Raw products and lectin were treated by heating or soaking in ginger juice or alum solution. The effects of different excipients and the heating methods on lectin proteins were investigated. The results showed that the content of lectin in raw products of P. pedatisecta,P. ternata,A. heterophyllum,and T. giganteum were 7. 3%,4. 9%,2. 7%,2. 3%,respectively. And the content of lectin in Pinelliae Rhizoma praeparatum cum alumine was 0. 027%. Lectin was not detected in the Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine,Arisaematis Rhizma Praeparatum and Typhonii Rhizoma Praeparatum,which indicated that processing could significantly reduce the content of active lectin in raw products. The results also showed that with the prolongation of soaking and heating time,the content of lectin in raw products decreased gradually,while the content was almost unchanged when soaked in ginger juice alone. The effects of different excipients and heating on lectin were the same as those on raw products. Therefore,the method with alum soaking and heating can reduce the content of active lectin,which is the key to reduce the toxicity of toxic Chinese medicines. In this paper,Western blot was used to study the content of toxic protein in Araceae toxic Chinese medicines as an evaluation method of the processing degree.


Assuntos
Araceae/química , Química Farmacêutica/métodos , Medicamentos de Ervas Chinesas/análise , Lectinas/análise , Tubérculos/química , Rizoma/química
10.
J Org Chem ; 82(17): 9253-9257, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28748692

RESUMO

The C70 δ-adducts with closed [5,6]-ring fusion are an important type of compound in classifying bond delocalization in the equatorial belt of C70. However, the formation of such compounds is severely restricted due to the low reactivity of the carbon atoms in the flat equatorial region. Such a restriction is lifted when reduced anionic C70 species are used, where the inert equatorial carbon atoms are activated.

11.
J Org Chem ; 82(16): 8676-8685, 2017 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-28731698

RESUMO

C60 o-quinodimethane bisadducts [C60(QM)2] are promising electron acceptors for bulk heterojuction (BHJ) organic solar cells (OSCs). However, previous production of C60(QM)2 often resulted in excessive regioisomers, which were difficult to purify and might consequently obscure the structure-performance study of the organofullerene acceptors. Herein, the electrosynthesis of C60(QM)2 is reported. The reaction exhibits a strong regiocontrol with generation of fewer regioisomers. Pure regioisomers of cis-2, trans-3, and e C60(QM)2 are obtained, and the structures are solved with single-crystal X-ray diffraction. Interestingly, the cis-2 and trans-3 regioisomers exhibit better photovoltaic performance than the e regioisomer in the OSCs based on poly(3-hexylthiophene) (P3HT), which can be correlated with their structural difference.

13.
Chemistry ; 22(52): 18709-18713, 2016 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-27735092

RESUMO

Despite being widely used as electron acceptor in polymer solar cells, commercially available PC71 BM (phenyl-C71 -butyric acid methyl ester) usually has a "random" composition of mixed regioisomers or stereoisomers. Here PC71 BM has been isolated into three typical isomers, α-, ß1 - and ß2 -PC71 BM, to establish the isomer-dependent photovoltaic performance on changing the ternary composition of α-, ß1 - and ß2 -PC71 BM. Mixing the isomers in a ratio of α/ß1 /ß2 =8:1:1 resulted in the best power conversion efficiency (PCE) of 7.67 % for the polymer solar cells with PTB7:PC71 BM as photoactive layer (PTB7=poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]]). The three typical PC71 BM isomers, even though sharing similar LUMO energy levels and light absorption, render starkly different photovoltaic performances with average-performing PCE of 1.28-7.44 % due to diverse self-aggregation of individual or mixed PC71 BM isomers in the otherwise same polymer solar cells.

14.
Phys Chem Chem Phys ; 18(28): 18683-6, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27375165

RESUMO

Negative ion photoelectron spectroscopy shows interesting regioisomer-specific electron affinities (EAs) of 2,5- and 7,23-para-adducts of C70 [(ArCH2)2C70] (Ar = Ph, o-, m-, and p-BrC6H4). Their EA values are larger than that of C70 by 5-150 meV with the 2,5-polar adducts' EAs being higher than their corresponding 7,23-equatorial counterparts, exhibiting appreciable EA tunable ranges and regioisomeric specificity. Density functional theory (DFT) calculations reproduce both the experimental EA values and EA trends very well.

15.
Chemistry ; 21(5): 1894-9, 2015 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-25488150

RESUMO

Reactions of 2,5-Bn2 C70 (Bn=CH2 Ph) with hydroxide and ArCN (Ar=Ph, m-ClPh) followed by quenching with I2 and BnBr afforded dibenzylated and tetrabenzylated oxazolino[70]fullerenes, respectively. The latter has a novel structural configuration, in which the addends are positioned from the polar to the transequatorial region. A key structural feature of this compound is that the oxygen atom of the oxazoline ring is bound to the equatorial belt region of C70 , giving structural change in its reduced state. This enables stabilization of the reduced state, suppressing charge recombination dynamics in organic solar cells to give a high open-circuit voltage (0.85, 0.93, and 1.11 V in devices using P3HT, PTB7, and DPP(TBFu)2 , respectively).

16.
J Org Chem ; 80(7): 3566-71, 2015 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-25748639

RESUMO

Upon reduction, singly bonded 1,2,4,15-C60 dimers with an oxazoline or imidazoline heterocycle dissociate into monoanionic 1,2,4-C60 intermediates, which surprisingly leads to the formation of 1,2,3,16-C60 rather than 1,2,4,15-C60 adducts of the original configuration by further benzylation, even though the analogue of dibenzylated C60 oxazoline with a 1,2,4,15-configuration is stable and has been obtained. These results are corroborated by computational calculations, which rationalize the reaction and clarify the structure of the 1,2,3,16-C60 adducts, providing new insights into the intrinsic reactivity of singly bonded C60 dimers.

17.
J Phys Chem A ; 119(36): 9534-40, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26291551

RESUMO

Reduced fullerenes and fullerene derivatives exhibit intense absorptions in the vis-near-IR (vis-NIR) region. The absorptions are sensitive toward the addition pattern, number of addends, and oxidation state of the fullerene species and are used as an important benchmark for identifying anionic fullerene species. Similar absorptions are also shown for the reduced singly bonded C60 species, which are electronically different from reduced fullerene derivatives. However, much less work has been carried out on the vis-NIR spectroscopic study of the anionic singly bonded C60 species, likely due to the difficulty in controlled production of these species. Herein, we report the vis-NIR spectroscopic study of the mono- and dianions of the singly bonded C60 species (RC60(-), R(-)C60(-), and RC60(2-•)), which are selectively generated by controlled-potential bulk electrolysis (CPE) of the singly bonded C60 dimer and C60 oxazolino heterocycles. Time-dependent density functional theory (TD-DFT) calculations were performed to rationalize the experimental results.

18.
J Org Chem ; 79(1): 197-203, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24188469

RESUMO

Oxazoline and imidazoline functionalization of a singly bonded C60 dimer is achieved via a one-pot reaction of C60HBn with OH(-) and aromatic nitriles, where the OH(-) not only functions as a Brønsted base that deprotonates C60HBn but also as a nucleophile that initiates the nucleophilic addition to the fullerene cage. The structures of the obtained oxazolinated and imidazolinated C60 dimeric compounds have been established by HRMS, UV-vis, and (1)H, (13)C, and HMBC NMR characterizations and computational calculations. The reaction mechanism is studied with the in situ vis-near-IR spectra, which shows that the use of I2 is crucial for the functionalization of the C60 dimer, indicating that it is likely the dimeric molecule rather than the fragment of the dimer that is involved in the reaction.

19.
Hepatogastroenterology ; 61(129): 120-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24895806

RESUMO

BACKGROUND/AIMS: To determine whether the use of narrow-band imaging (NBI) system could enhance the detection rate of esophageal squamous cell carcinoma and precancerous lesions during endoscopic examination of the esophagus. METHODOLOGY: 113 patients were randomized to undergo endoscopic examination using high definition television (HDTV) narrow band imaging (NBI) endoscopy or HDTV WL endoscopy. The primary endpoint was the difference in the neoplasm miss rate, and secondary outcome was the neoplasm detection rate. RESULTS: The number of esophageal cancer and high grade intraepithelial neoplasia lesions detected by HD-NBI and HD-WL was 45 and 21, respectively. The neoplasm miss rate per lesion and per patient with HD-NBI showed significant difference compared with that of HD-WL (P <0.05). Characteristics of lesions missed by use of HD-NBI were similar to those missed by use of HD-WL; all missed lesions were high grade intraepithelial neoplasia lesions. Significant difference was observed between NBI and WL in adenoma detection rate (70.2% vs. 35.7%, P < 0.01). CONCLUSIONS: Endoscopy with HD-NBI seems to improve the detection of esophageal cancer and precancerous lesions, high definition may be tested for its effect on detection of esophageal cancer and precancerous lesions in the future. These results indicate that endoscopy routinely using the NBI system for the surveillance of esophageal cancer and precancerous lesions may be recommended.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Erros de Diagnóstico/estatística & dados numéricos , Neoplasias Esofágicas/diagnóstico , Esofagoscopia/métodos , Lesões Pré-Cancerosas/diagnóstico , Diagnóstico Diferencial , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
ChemSusChem ; 17(4): e202301662, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38169145

RESUMO

Perovskite solar cell (PSC) shows a great potential to become the next-generation photovoltaic technology, which has stimulated researchers to engineer materials and to innovate device architectures for promoting device performance and stability. As the power conversion efficiency (PCE) keeps advancing, the importance of exploring multifunctional materials for the PSCs has been increasingly recognized. Considerable attention has been directed to the design and synthesis of novel organic π-conjugated molecules, particularly the emerging curved ones, which can perform various unmatched functions for PSCs. In this review, the characteristics of three representative such curved π-conjugated molecules (fullerene, corannulene and helicene) and the recent progress concerning the application of these molecules in state-of-the-art PSCs are summarized and discussed holistically. With this discussion, we hope to provide a fresh perspective on the structure-property relation of these unique materials toward high-performance and high-stability PSCs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA