Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
1.
Ann Surg Oncol ; 31(6): 3803-3812, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38280959

RESUMO

BACKGROUND: Neoadjuvant chemoradiotherapy (NCRT) has shown promise in improving the prognosis of individuals with locally advanced esophageal squamous cell carcinoma (LA-ESCC). However, the factors influencing tumor response and long-term survival in these patients remain unknown. The optimal timing for surgery after the completion of radiotherapy in LA-ESCC remains controversial. Therefore, this study was designed to identify biomarkers and to determine the optimal post-NCRT time-to-surgery (TTS) for patients with LA-ESCC. METHODS: This retrospective study included patients with resectable LA-ESCC who underwent NCRT between May 2017 and June 2021. The tumor shrinkage rate was calculated as the difference between the pre- and post-primary gross tumor volume (GTVp) divided by the pre-GTVp. Univariate and multivariate Cox regression analyses and Kaplan-Meier curves were used to calculate overall survival (OS) and progression-free survival (PFS). RESULTS: We collected data from 248 patients with resectable LA-ESCC who underwent computed tomography (CT) scans before the initiation of treatment. The median follow-up time was 37.7 months. The optimal cutoff of tumor shrinkage was 45%. In the univariate and multivariate analyses, we found a significant association between the tumor shrinkage rate and PFS (p = 0.001). Among the subgroup of patients who responded to treatment, extending the TTS was associated with improved OS (p = 0.037) and PFS (p = 0.028). CONCLUSIONS: For patients with resectable LA-ESCC, the tumor shrinkage rate is an independent prognostic factor for PFS. Thus, for responders, prolonging TTS is recommended to obtain a better OS.


Assuntos
Neoplasias Esofágicas , Esofagectomia , Terapia Neoadjuvante , Tempo para o Tratamento , Carga Tumoral , Humanos , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/terapia , Neoplasias Esofágicas/mortalidade , Masculino , Estudos Retrospectivos , Feminino , Terapia Neoadjuvante/mortalidade , Pessoa de Meia-Idade , Taxa de Sobrevida , Idoso , Seguimentos , Prognóstico , Quimiorradioterapia/mortalidade , Carcinoma de Células Escamosas do Esôfago/terapia , Carcinoma de Células Escamosas do Esôfago/patologia , Adulto , Quimiorradioterapia Adjuvante
2.
Inorg Chem ; 63(23): 10798-10808, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38781309

RESUMO

Cu-SSZ-39 zeolite with 8-membered rings is regarded as a very promising catalyst in the NH3-SCR reaction, but its hydrothermal stability still remains to be improved. One of the solutions to promote hydrothermal stability is the insertion of rare earth elements in the product. Nevertheless, normal ion exchange of rare earth elements limits their contents in the zeolite product due to their large hydrated ionic radius and alkaline environment under hydrothermal conditions. Herein, we for the first time present a new method for the one-pot synthesis of Ce-SSZ-39 zeolite under solvent-free conditions. The key to success is the use of Ce-FAU zeolite as a precursor. The obtained product shows good crystallinity, sheet-like morphology, large BET surface area, and 4-coordinated Al species. Detailed investigations illustrate that Ce species in the Cu/Ce-SSZ-39 zeolite micropore can prevent the dealumination and thus formation of CuAlOx species during hydrothermal aging at 850 °C for 16 h, giving the excellent hydrothermal stability and thus showing the excellent catalytic performance in the NH3-SCR reaction. One-pot synthesis of Ce-SSZ-39 zeolite with excellent catalytic performance might open a new door for developing very efficient selective catalytic reduction (SCR) catalysts in near future.

3.
World J Urol ; 41(11): 2889-2896, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37243718

RESUMO

PURPOSE: To assess the safety and effectiveness of magnetic ureteric stent removal with a special magnet retriever under ultrasound guidance. METHODS: A total of 60 male patients, who underwent ureteroscopy from October 2020 to March 2022, were prospectively enrolled and randomized into two groups. Group A patients underwent conventional double-J (DJ) stent insertion and subsequent stent removal via flexible cystoscopy. Group B patients underwent stent insertion using magnetic ureteric stent [Blackstar, Urotech (Achenmühle, Germany)] and stents were removed using a special magnet retriever under ultrasound guidance. Stents were left in situ for 30 days in both groups. All patients had follow-ups with a ureter stent symptoms questionnaire at 3- and 30-days post stent insertion. Visual analog scale (VAS) was assessed immediately after stent removal. RESULTS: Stent removal time (142.5 s vs 142.5 s, group A vs group B, p < 0.0001) and VAS scores (4 vs 1, group A vs group B, p = 0.0008) were significantly lower in Group B. There were no statistically significant differences between both groups in the "urinary symptoms" (p = 0.3471) and "sexual matters" (p = 0.6126) in the USSQ domains. There was marginal statistical significance favoring Group A in the "body pain" (p = 0.0303), "general health score" (p = 0.0072), "additional problems" (p = 0.0142), and "work performance" (p < 0.0001) domains. CONCLUSIONS: Magnetic ureteric stent can be considered as a safe and efficient alternative to conventional DJ stent. This approach avoids the need for cystoscopy, saving resources while minimizing patient discomfort.


Assuntos
Ureter , Humanos , Masculino , Ureter/cirurgia , Ureteroscopia , Dor/etiologia , Stents , Fenômenos Magnéticos
4.
Clin Transplant ; 37(11): e15069, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37410577

RESUMO

INTRODUCTION: Grafts with multiple renal arteries (MRAs) were historically considered a relative contraindication to transplantation due to the higher risk of vascular and urologic complications. This study aimed to evaluate graft and patient survival between single renal artery (SRA) and MRA living-donor kidney transplants. METHODS: An electronic literature search was conducted on PubMed, EMBASE, and Scopus for prospective or retrospective studies comparing SRA versus MRA in living donor renal transplantation, with the provision of Kaplan-Meier curves for recipient overall survival (OS) or graft survival (GS). A graphical reconstructive algorithm was used to obtain OS and GS of individual patients, which was then pooled under random-effects individual patient data (IPD) meta-analysis using Cox-models to determine hazard ratios (HRs) and 95% confidence intervals (CIs). Meta-regression of baseline covariates versus HRs of OS and GS was performed for variables reported in 10 or more studies. RESULTS: Fourteen studies were retrieved, of which 13 (8400 patients) reported OS and 9 (6912 patients) reported GS. There were no significant differences in OS (shared-frailty HR = .94, 95%CI = .85-1.03, p = .172) or GS (shared-frailty HR = .95, 95%CI = .83-1.08, p = .419) between SRA and MRA. This comparison remained non-significant even when restricted to open- or laparoscopic-only studies. Meta-regression yielded no significant associations of GS with donor age, recipient age, and percentage of double renal arteries within the MRA arm. CONCLUSIONS: The similar rates of GS and OS between MRA and SRA grafts suggest that there is no need for discrimination between the two when evaluating donors for nephrectomy.


Assuntos
Fragilidade , Nefropatias , Transplante de Rim , Doenças Vasculares , Humanos , Transplante de Rim/efeitos adversos , Artéria Renal/cirurgia , Doadores Vivos , Estudos Retrospectivos , Estudos Prospectivos , Resultado do Tratamento , Rim/cirurgia , Sobrevivência de Enxerto
5.
Nano Lett ; 20(7): 5236-5242, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32501705

RESUMO

Epitaxial growth of an inert shell around the optical active lanthanide upconversion nanoparticles (UCNPs) is a general strategy to enhance their brightness. Yet, its potential as a tool in multiplexing emission tailoring has rarely been reported. Here, by developing the atomic vacancies into color selectivity actuators, we present an efficient strategy to achieve inert-shell-modulated multiplexing upconversion in 1540 nm activated UCNPs. Artificially generated fluoride atomic vacancies, owing to the decreased NaOH/NH4F dosage during shell growth, reduce the coordination number of Y-F and lattice densities in the inert shell, leading to the core-engineered shell nanoparticles with distinctive emission profiles. The multicolor tailoring is independent of shell thickness and can be readily applied to Lu3+/Gd3+-based shells. The upconversion emission can be exploited to visualize in security decoding and in vivo multiplexing bioimaging. This method of regulating atomic vacancies based on the inert-shell engineering opens new insights of upconversion modulation in core-shell lanthanide nanostructures.

6.
J Urol ; 201(3): 556-562, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30316894

RESUMO

PURPOSE: Emergency department visits after ureteroscopy are costly and inconvenient. To better understand those at risk we aimed to identify patient demographic, medical and surgical factors associated with 30-day emergency department presentation following ureteroscopy for urolithiasis with particular attention to those with a history of a psychiatric diagnosis. MATERIALS AND METHODS: We retrospectively reviewed 1,576 cases (1,395 adults) who underwent stone related ureteroscopy during 3 years at a total of 2 hospitals. We collected patient demographics, medical history and operative details. The primary outcome was return to the emergency department within 30 days of ureteroscopy. Logistic regression was performed to examine factors associated with emergency department presentation. RESULTS: Of the patients 613 (43.9%) had a history of psychiatric diagnosis. Of those with ureteroscopy encounters 12.6% returned to the emergency department within 30 days of ureteroscopy, including 58.8% with a history of psychiatric diagnosis. On multivariable analysis variables associated with emergency department return included a history of psychiatric diagnosis (OR 1.57, p = 0.012), uninsured status (OR 2.46, p = 0.001) and a stone only in the kidney (OR 1.76, p = 0.022). Patients who returned to the emergency department had had more emergency department visits in the year prior to surgery (OR 1.40, p <0.001). On univariable analysis older patients and those with longer operative time were more frequently admitted from the emergency department (OR 1.03, p = 0.002 and OR 1.96, p = 0.03. respectively) while uninsured patients were admitted less frequently (OR 0.19, p = 0.013). No difference was noted in admissions between those with a psychiatric diagnosis and all others (60.7% vs 55.8%, p = 0.48). CONCLUSIONS: We identified factors associated with emergency department return after ureteroscopy, including a history of psychiatric diagnosis, uninsured status and emergency department visits in the year before surgery. These patients may benefit from targeted interventions to help avoid unnecessary emergency department visits.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Ureteroscopia/estatística & dados numéricos , Urolitíase/epidemiologia , Urolitíase/cirurgia , Assistência Ambulatorial/estatística & dados numéricos , Comorbidade , Feminino , Humanos , Masculino , Pessoas sem Cobertura de Seguro de Saúde/estatística & dados numéricos , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Ureteroscopia/psicologia
9.
Tumour Biol ; 39(4): 1010428317697578, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28381159

RESUMO

The long and short noncoding RNAs have been involved in the molecular diagnosis, targeted therapy, and predicting prognosis of lung cancer. Utilizing noncoding RNAs as biomarkers and systemic RNA interference as an innovative therapeutic strategy has an immense likelihood to generate novel concepts in precision oncology. Targeting of RNA interference payloads such as small interfering RNAs, microRNA mimetic, or anti-microRNA (antagomirs) into specific cell types has achieved initial success. The clinical trials of noncoding RNA-based therapies are on the way with some positive results. Many attempts are done for developing novel noncoding RNA delivery strategies that could overcome systemic or local barriers. Furthermore, it precipitates concerted efforts to define the molecular subtypes of lung cancer, characterize the genomic landscape of lung cancer subtypes, identify novel therapeutic targets, and reveal mechanisms of sensitivity and resistance to targeted therapies. These efforts contribute a visible effect now in lung cancer precision medicine: patients receive molecular testing to determine whether their tumor harbors an actionable come resistance to the first-generation drugs are in clinical trials, and drugs targeting the immune system are showing activity in patients. This extraordinary promise is tempered by the sobering fact that even the newest treatments for metastatic disease are rarely curative and are effective only in a small fraction of all patients. Thus, ongoing and future efforts to find new vulnerabilities of lung cancers unravel the complexity of drug resistance, increase the efficacy of immunotherapies, and perform biomarker-driven clinical trials are necessary to improve the outcome of lung cancer patients.


Assuntos
Neoplasias Pulmonares/tratamento farmacológico , Medicina de Precisão , RNA Longo não Codificante/administração & dosagem , Pequeno RNA não Traduzido/administração & dosagem , Ensaios Clínicos como Assunto , Resistencia a Medicamentos Antineoplásicos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/prevenção & controle , Interferência de RNA , RNA Longo não Codificante/fisiologia , Pequeno RNA não Traduzido/fisiologia
10.
Acta Pharmacol Sin ; 38(12): 1642-1654, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28713155

RESUMO

Hepatocellular carcinoma (HCC) is one of the most refractory cancers. The mechanisms by which hypoxia further aggravates therapeutic responses of advanced HCC to anticancer drugs remain to be clarified. Here, we report that hypoxia (1% O2) caused 2.55-489.7-fold resistance to 6 anticancer drugs (sorafenib, 5-fluorouracil [5-FU], gemcitabine, cisplatin, adriamycin and 6-thioguanine) in 3 HCC cell lines (BEL-7402, HepG2 and SMMC-7721). Among the 6 drugs, sorafenib, the sole one approved for HCC therapy, inhibited proliferation with little influence from hypoxia and displayed the smallest variation among the 3 HCC cell lines tested. By contrast, the inhibition of proliferation by 5-FU, which has been extensively tested in clinical trials but has not been approved for HCC therapy, was severely affected by hypoxia and showed a large variation among these cell lines. In 5-FU-treated HCC cells, hypoxia reduced the levels of basal thymidylate synthase (TS) and functional TS, leading to decreased dTMP synthesis and DNA replication. Hypoxia also affected the accumulation of FdUTP and its misincorporation into DNA. Consequently, both single-strand breaks and double-strand breaks in DNA were reduced, although hypoxia also inhibited DNA repair. In 5-FU-treated HCC cells, hypoxia further abated S-phase arrest, alleviated the loss of mitochondrial membrane potential, diminished the activation of caspases, and finally resulted in reduced induction of apoptosis. Thus, hypoxia induces universal but differential drug resistance. The extensive impacts of hypoxia on the anticancer mechanisms of 5-FU contributes to its hypoxia-induced resistance in HCC cells. We propose that hypoxia-induced drug resistance and interference of hypoxia with anticancer mechanisms could be used as candidate biomarkers in selecting and/or developing anticancer drugs for improving HCC therapy.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Fluoruracila/farmacologia , Hipóxia/metabolismo , Antineoplásicos/química , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Fluoruracila/química , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Relação Estrutura-Atividade , Células Tumorais Cultivadas
11.
Yi Chuan ; 37(8): 756-64, 2015 08.
Artigo em Zh | MEDLINE | ID: mdl-26266779

RESUMO

Recent studies demonstrate that RNA species could regulate each other by competing for shared microRNA response elements (MREs). This regulatory model is called competing endogenous RNA (ceRNA). Currently, the identified ceRNAs cover coding and non-coding RNAs. The latter includes pseudogene transcripts, long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and so on. In this review, we summarize the biological functions of regulatory networks consisting of various types of ceRNAs and their roles in the pathological and physiological processes. Additionally, several factors that may regulate ceRNAs were discussed.


Assuntos
Pseudogenes/fisiologia , RNA Longo não Codificante/fisiologia , RNA/fisiologia , Animais , Redes Reguladoras de Genes , Humanos , MicroRNAs/fisiologia , RNA Circular , RNA Mensageiro/fisiologia
12.
Yi Chuan ; 36(7): 637-45, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25076027

RESUMO

Distant metastasis of tumor cell is a series of continuous, selectable cascades of events regulated by multiple factors and genes. Epithelial-mesenchymal transition (EMT) is a critical step during cancer metastasis. However, the mechanism of EMT in tumor is not yet fully elucidated. MicroRNAs (miRNAs) are a class of non-coding small endogenous RNAs that negatively regulate EMT-related genes at the post-transcriptional level and play critical roles in cancer metastasis. This review mainly focuses on the topics that include the relationship of EMT and tumor metastasis, transcription factors involved in EMT, and the effect of miRNAs on tumor metastasis by targeting the EMT-related transcription factors.


Assuntos
Transição Epitelial-Mesenquimal , MicroRNAs/metabolismo , Neoplasias/metabolismo , Animais , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , Metástase Neoplásica , Neoplasias/genética , Neoplasias/patologia , Neoplasias/fisiopatologia
13.
Eur Urol Focus ; 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39098447

RESUMO

Testicular germ cell tumours (GCTs) account for the majority of testicular malignancies. Seminomas and nonseminomas differ in prognosis and management strategies. While cisplatin-based chemotherapy has significantly improved survival rates, identification of residual masses after chemotherapy is crucial for determining further treatment and survival. For seminomas, spontaneous resolution of residual masses occurs in a significant percentage of cases. Fluorodeoxyglucose positron emission tomography (FDG PET) is recommended for evaluation of residual masses after chemotherapy. Retroperitoneal lymph node dissection (RPLND) offers therapeutic benefits but is challenging because of an increase in desmoplasia after chemotherapy. For nonseminomas, residual masses are common after chemotherapy, with surgical resection necessary for masses larger than 1 cm. FDG PET has limited utility, and timely surgical intervention is crucial for favourable outcomes. Teratoma, if left unresected, can lead to serious complications, including growing teratoma syndrome, malignant transformation, and late relapse. Extraretroperitoneal residual masses, particularly those containing teratoma, are associated with poorer prognosis. Surgical resection remains the mainstay treatment, with significantly higher progression-free and recurrence-free survival rates for fibrosis/necrosis in comparison to teratoma or viable cancer. Understanding the characteristics and management of residual masses after chemotherapy is paramount for optimising treatment strategies and improving patient outcomes in testicular GCT. PATIENT SUMMARY: We reviewed treatment options for patients with testicular cancer who still have tumour tissue in the lower abdomen after chemotherapy. Surgical removal of the tumour is the main option; removal of lymph nodes can also help, but may be difficult because of tissue reactions to chemotherapy. Survival rates differ according to the tumour type and are lower for tumours beyond the lower abdomen.

14.
Radiother Oncol ; 197: 110334, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38801945

RESUMO

BACKGROUND: All known randomized trials of stereotactic radiotherapy (SRT) versus whole brain radiotherapy (WBRT) for brain metastases (BMs) comprise mixed histologies. The phase III HYBRID trial (NCT02882984) attempted to evaluate the non-inferiority of SRT vs. WBRT specifically for EGFR-mutated non-small cell lung cancer (EGFRm NSCLC) BMs. METHODS: Inclusion criteria were ≤ 5 BMs (any size) from treatment-naïve EGFRm NSCLC. All patients started a first-generation tyrosine kinase inhibitor on the first day of WBRT (37.5 Gy/15 fractions) or SRT (25-40 Gy/5 fractions per tumor volume). The primary endpoint was 18-month intracranial progression-free survival (iPFS; intention-to-treat). RESULTS: The trial commenced in June 2015 and was closed in April 2021 after screening 208 patients but enrolling 85 (n = 41 WBRT, n = 44 SRT; median follow-up 31 and 36 months, respectively). Respectively, 9.5 % vs. 10.2 % of patients experienced intracranial progression at 18 months, and the median iPFS was 21.4 vs. 22.3 months (p > 0.05 for all). The SRT arm experienced higher overall survival and cognitive preservation (p < 0.05 for all). The most notable reason for low enrollment was patients not wishing to risk neurocognitive decline from WBRT. CONCLUSIONS: Although this phase III trial was underpowered, there was no evidence that SRT yielded outcome detriments compared to WBRT for EGFRm NSCLC BMs. Lessons from prematurely closed trials are valuable, as they often provide important experiential perspectives for investigators designing/executing future trials. In the current era, randomized trials involving WBRT without cognitive sparing measures may be at high risk of underaccrual; trial investigators are encouraged to carefully consider our experience when attempting to design such trials. However, trials of molecular-/biologically-stratified patients are highly recommended as the notion of "individualized medicine/oncology" continues to expand.


Assuntos
Neoplasias Encefálicas , Carcinoma Pulmonar de Células não Pequenas , Receptores ErbB , Neoplasias Pulmonares , Radiocirurgia , Humanos , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Radiocirurgia/métodos , Receptores ErbB/genética , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Irradiação Craniana/métodos , Mutação , Término Precoce de Ensaios Clínicos , Adulto , Intervalo Livre de Progressão , Idoso de 80 Anos ou mais
15.
J Colloid Interface Sci ; 631(Pt A): 222-230, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36375302

RESUMO

The metal ion etching induced transformation of zeolitic imidazolate frameworks (ZIFs) to layered double hydroxides (LDHs) is closely related to the etching conditions. Here, by tuning the Ni2+ etching conditions (e.g., initial Ni2+ concentration and etching time), Co-ZIF-L templated CoNi-LDH with diverse morphologies and tailorable compositions are obtained and their resultant electrochemical properties are optimized. Mechanism study reveals that the etching conditions significantly affect the disassembling rate of Co-ZIF-L as well as the formation rate of CoNi-LDH, leading to the morphological and compositional variance of etched samples, which further results in their distinct electrochemical activities. The resultant asymmetric supercapacitor assembled with Co-ZIF-L derived CoNi-LDH and activated carbon can achieve a maximum energy density of 77.3 Wh/kg at a power density of 700 W/kg with the capacity retention of 85.7 % after 2000 cycles, superior or comparable to other advanced CoNi-LDH based supercapacitors.

16.
J Colloid Interface Sci ; 629(Pt A): 786-793, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36099846

RESUMO

CoS2/Co-Ni layered double hydroxides (LDHs) with a rational tailored pore structure are developed by partial sulfurization of Co-ZIF-L and subsequent Ni2+ etching for the transformation of zeolitic imidazolate frameworks (ZIFs) to layered double hydroxides. The as-synthesized CoS2/Co-Ni LDHs maintain the leaf-like structure and have rich hierarchical pores. More importantly, CoS2 nanoparticles are uniformly embedded among Co-Ni LDH layers, facilitating mass diffusion and favorably exposing more active sites. Benefiting from these desirable compositional and structural features, a remarkable specific capacitance (capacity) of 1784 F/g (223 mAh/g) at 1 A/g is delivered by CoS2/Co-Ni LDHs. Furthermore, the as-assembled CoS2/Co-Ni LDH//activated carbon as the asymmetric supercapacitor device also exhibits a high energy density of 125 Wh/kg at a power density of 800 W/kg and a superb capacitance retention of 98 % after 5000 cycles, outperforming many Co-Ni LDH based electrode materials reported in the literature.

17.
Talanta ; 254: 124175, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36527911

RESUMO

A novel ratiometric fluorescent tyrosinase assay is developed based on hybrid nano-assembly of gold nanocluster and tyrosine-containing peptides. The AuNCs@YCY nano-probe (AYNP) is fabricated through the hydrophobic interactions and π-π stacking between the tyrosine residues of the Tyr-Cys-Tyr tripeptide (YCY) and the ligands on the surfaces of AuNCs under the near-isoelectric pH value. The resulted AYNP shows distinct fluorescence responses, spontaneous turn-on of the blue emission and turn-off of the near-infrared emission, with a single wavelength excitation. It is demonstrated that the enhancement and quenching are due to the production of pheomelanin and dopaquinone structures, respectively, induced by tyrosinase oxidation. The internal referencing system provides the tyrosinase assay with superior sensitivity and a detection limit as low as 6.3 U L-1 could be achieved. The experimental results also demonstrate the excellent selectivity, good photo-stability, and both in vitro and cellular applications of AYNP. This assay technique is low-cost, easy to prepare, and shows excellent potential as a novel melanoma clinical diagnostic platform and a tyrosinase inhibitor screening tool.


Assuntos
Corantes Fluorescentes , Monofenol Mono-Oxigenase , Corantes Fluorescentes/química , Tirosina , Oxirredução , Ouro/química
18.
J Colloid Interface Sci ; 617: 383-390, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35279573

RESUMO

Metal ion-induced etching can effectively convert zeolitic imidazolate frameworks (ZIFs) to CoNi-layered double hydroxides (LDH). Here, different metal-ion-assisted etching methods are utilized to convert Co-ZIF-L to CoNi-LDH with various morphologies and electrochemical properties. The resultant CoNi-LDH (CoNi-1) with a composition of Co0.7Ni0.3(OH)2 displayed a high electrochemical performance when Co-ZIF-L was treated in N, N-dimethylformamide-ethanol solution containing Co2+ ions followed by Ni2+ ion-induced etching under hydrothermal condition. The improved electrochemical performance of CoNi-1 can be attributed to structural advantages, where the well-dispersed ultrathin CoNi-LDH layers favor the exposure of surface active sites and promote ion diffusion to maximize electrochemical properties.

19.
Int J Biol Macromol ; 217: 428-434, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-35843394

RESUMO

It is still a challenge to find an effective solvent system that can simultaneously dissolve the cellulose and lignin in biomass residues to fabricate lignocellulose hydrogels (LHs). Herein, corncob residues from furfural production were pretreated with alkaline peroxide to regulate the lignin content. The lignin/cellulose composites with various lignin content were then dissolved and regenerated by a green and facile ZnCl2/CaCl2 solvent system. The inorganic salt solvents were served as linkers and flexible LHs were obtained. Substrate material containing 10.75% lignin shows the best compressive stress (76.71 kPa). Inspired by its superior ionic conductivity, the hydrogels were assembled into a solid-state electrolyte for a zinc-ion hybrid supercapacitor. This research develops a feasible, simple, and low-cost route for lignin-containing hydrogel preparation and offers insights into the high-value application of agro-industrial lignocellulosic wastes.


Assuntos
Lignina , Zea mays , Biomassa , Celulose/química , Hidrogéis , Lignina/química , Solventes/química
20.
Stem Cell Rev Rep ; 18(4): 1423-1433, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34855111

RESUMO

BACKGROUND: Human pluripotent stem cells (hPSCs) have started to emerge as a potential tool with application in fields of drug discovery, disease modelling and cell therapy. A variety of protocols for culturing and differentiating pluripotent stem cells into pancreatic ß like cells have been published. However, small-scale dynamic suspension culture systems, which could be applied toward systematically optimizing production strategies for cell replacement therapies to accelerate the pace of their discovery and development toward the clinic, are overlooked. METHODS: Human embryonic stem cell (hESC) line H9 was used to establish the novel 48-well dynamic suspension culture system. The effects of various rotational speeds and culture medium volumes on cell morphology, cell proliferation, cell viability and cell phenotype were evaluated. Effect of cell density on the pancreatic differentiation efficiency from H9 cells in 48-well plates was further investigated. In vitro the function of pancreatic ß like cells was assessed by measuring glucose-stimulated insulin secretion. MAIN RESULTS: A 48-well dynamic suspension culture system for hESC expansion as cell aggregates was developed. With optimized rotational speed and culture medium volume, hESCs maintained normal karyotype, viability and pluripotency. Furthermore, the system can also support the hESC aggregates subsequent differentiation into functional pancreatic ß like cells after optimizing initial cell seeding density. CONCLUSION: A controllable 48-well suspension culture system in microplates for hESCs maintenance, expansion and pancreatic differentiation was developed, which may provide an efficient platform for high-throughput drug screening.


Assuntos
Células-Tronco Embrionárias Humanas , Células-Tronco Pluripotentes , Técnicas de Cultura de Células/métodos , Diferenciação Celular , Células Cultivadas , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA