Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; 20(25): e2311101, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38234132

RESUMO

Developing novel substances to synergize with nanozymes is a challenging yet indispensable task to enable the nanozyme-based therapeutics to tackle individual variations in tumor physicochemical properties. The advancement of machine learning (ML) has provided a useful tool to enhance the accuracy and efficiency in developing synergistic substances. In this study, ML models to mine low-cytotoxicity oncolytic peptides are applied. The filtering Pipeline is constructed using a traversal design and the Autogluon framework. Through the Pipeline, 37 novel peptides with high oncolytic activity against cancer cells and low cytotoxicity to normal cells are identified from a library of 25,740 sequences. Combining dataset testing with cytotoxicity experiments, an 80% accuracy rate is achieved, verifying the reliability of ML predictions. Peptide C2 is proven to possess membranolytic functions specifically for tumor cells as targeted by Pipeline. Then Peptide C2 with CoFe hollow hydroxide nanozyme (H-CF) to form the peptide/H-CF composite is integrated. The new composite exhibited acid-triggered membranolytic function and potent peroxidase-like (POD-like) activity, which induce ferroptosis to tumor cells and inhibits tumor growth. The study suggests that this novel ML-assisted design approach can offer an accurate and efficient paradigm for developing both oncolytic peptides and synergistic peptides for catalytic materials.


Assuntos
Aprendizado de Máquina , Peptídeos , Peptídeos/química , Humanos , Linhagem Celular Tumoral , Animais , Neoplasias/terapia , Antineoplásicos/farmacologia , Antineoplásicos/química , Cobalto/química , Camundongos , Nanoestruturas/química
2.
Mar Drugs ; 22(6)2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38921550

RESUMO

Although lipophilic shellfish toxins (LSTs) pose a significant threat to the health of seafood consumers, their systematic investigation and risk assessment remain scarce. The goals of this study were as follows: (1) analyze LST levels in commercially available shellfish in Zhejiang province, China, and determine factors influencing LST distribution; (2) assess the acute dietary risk of exposure to LSTs for local consumers during the red tide period; (3) explore potential health risks of LSTs in humans; and (4) study the acute risks of simultaneous dietary exposure to LSTs and paralytic shellfish toxins (PSTs). A total of 546 shellfish samples were collected. LSTs were detected in 89 samples (16.3%) at concentrations below the regulatory limits. Mussels were the main shellfish species contaminated with LSTs. Spatial variations were observed in the yessotoxin group. Acute exposure to LSTs based on multiple scenarios was low. The minimum tolerable exposure durations for LSTs calculated using the mean and the 95th percentile of consumption data were 19.7 and 4.9 years, respectively. Our findings showed that Zhejiang province residents are at a low risk of combined exposure to LSTs and PSTs; however, the risk may be higher for children under 6 years of age in the extreme scenario.


Assuntos
Exposição Dietética , Toxinas Marinhas , Frutos do Mar , China , Humanos , Frutos do Mar/análise , Toxinas Marinhas/análise , Toxinas Marinhas/toxicidade , Animais , Medição de Risco , Exposição Dietética/análise , Intoxicação por Frutos do Mar/prevenção & controle , Intoxicação por Frutos do Mar/etiologia , Contaminação de Alimentos/análise , Adulto , Criança , Pessoa de Meia-Idade , Alimentos Marinhos/análise , Pré-Escolar , Bivalves/química , Feminino , Adulto Jovem
3.
Opt Express ; 29(13): 19240-19246, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34266037

RESUMO

In this paper, we propose and experimentally demonstrate a photonic scheme based on frequency doubling and photo-mixing to generate dual-chirp signals in the terahertz (THz) band. A broadband dual-chirp THz signal with 28 GHz bandwidth, ranging from 364 GHz to 392 GHz, is successfully generated in the proof-of-concept experiment, resulting in a chirp rate of 0.028 GHz/ns for both up chirp and down chirp signals. THz dual-chirp signals featuring a large bandwidth are beneficial to enable high resolution and high accuracy by mitigating the range measurement error induced by the range-Doppler coupling effect. Therefore, the proposed system is expected to have a great potential for future THz radar applications.

4.
Opt Lett ; 45(18): 5045-5048, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32932449

RESUMO

The terahertz band has been recognized as a promising candidate to support future rate-greedy applications such as 6G communications. Optoelectronic terahertz communications are beneficial for the realization of high-speed transmission. In this Letter, we propose and experimentally demonstrate an optoelectronic terahertz transmission system with intensity modulation and direct detection, where a discrete multitone (DMT) waveform with high-order quadrature amplitude modulation (QAM) is used. A zero-bias diode (ZBD) is used in the system as a simple, cost-effective direct detection terahertz receiver. A nonlinearity-aware digital signal reception routine is proposed to mitigate the nonlinear impairments induced by subcarrier-to-subcarrier beating interference from the ZBD. In this experiment, up to a 60 Gbit/s line rate 16QAM-DMT signal is successfully transmitted over a 3 m wireless link in the 310 GHz band, and the mean signal-to-noise ratio is improved by 3 dB with nonlinearity-aware signal processing routine. The advantageous features of such a scheme make it a promising solution for terahertz wireless communications.

5.
Urol Int ; 104(1-2): 22-27, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31163442

RESUMO

INTRODUCTION: Laparoendoscopic single-site (LESS) technique is a less invasive approach for radical cystectomy (RC), which is promising in reducing the incisional morbidity and improving the cosmesis of laparoscopic surgery. This study aimed to investigate the clinical and oncological outcomes for patients with malignant urinary bladder tumors that underwent the transurethral-assisted transumbilical LESS-RC. METHODS: From December 2014 to June 2017, 47 patients underwent LESS-RC combined with unilateral or bilateral cutaneous ureterostomy were enrolled in this study. The urethra was used as a potential approach without additional incision, which could allow for trocar insertion through natural orifices. Assessments were also conducted on preoperative, perioperative, postoperative, pathologic, and functional outcome data. RESULTS: Mean patient age was 73 years. Mean body mass index was 24.0 kg/m2. Median operating time and estimated blood loss measure 217 min and 178 mL, respectively. Four patients were diagnosed with positive lymph nodes. Two patients had positive surgical margins. No major perioperative complications occurred. Median postoperative follow-up time was 20.1 months. Two patients died due to their progressive disease. CONCLUSION: LESS can serve as a feasible and effective surgical procedure for RC to treat bladder cancer. With increasing experience and improvements, LESS-RC is promising to be a relatively acceptable alternative for minimally invasive surgery in some specific patients (with generally poor conditions that cannot be tolerated for a long time surgery, short life expectancy, advanced cancer, or associated with intestinal disease).


Assuntos
Cistectomia/métodos , Laparoscopia/métodos , Neoplasias da Bexiga Urinária/cirurgia , Bexiga Urinária/cirurgia , Procedimentos Cirúrgicos Urológicos/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Período Perioperatório , Período Pós-Operatório , Estudos Retrospectivos , Resultado do Tratamento , Uretra/cirurgia , Derivação Urinária/métodos
6.
Zhonghua Nan Ke Xue ; 23(10): 922-927, 2017 Oct.
Artigo em Zh | MEDLINE | ID: mdl-29727544

RESUMO

OBJECTIVE: To investigate the clinical effects of integrated traditional Chinese and Western medicine in the treatment of castration-resistant prostate cancer (CRPC). METHODS: A total of 54 CRPC patients were randomly divided into a control and a trial group, all treated by endocrine therapy (oral Bicalutamide at 50 mg per d plus subcutaneous injection of Goserelin at 3.6 mg once every 4 wk) and chemotherapy (intravenous injection of Docetaxel at 75 mg/m2 once every 3 wk plus oral Prednisone at 5 mg bid), while the latter group by Fuyang Huayu Prescription (a Traditional Chinese Medicine ï¼»TCMï¼½ prescription for tonifying yang and dispersing blood stasis) in addition, for a course of 24 weeks. Comparisons were made between the two groups of patients in the level of serum prostate-specific antigen (PSA), Karnofsky physical condition scores, function assessment of cancer therapy-prostate (FACT-P) scores, and TCM symptoms scores before and after 12 or 24 weeks of treatment. RESULTS: Compared with the baseline, the serum PSA level was significantly decreased after 12 weeks of treatment both in the control (ï¼»25.9 ± 39.3ï¼½ vs ï¼»20.0 ± 21.1ï¼½ µg/L, P <0.05) and in the trial group (ï¼»22.1 ± 33.9ï¼½ vs ï¼»17.9 ± 19.1ï¼½ µg/L, P <0.05), with no statistically significant differences between the two groups (P >0.05). At 24 weeks, however, the PSA levels in the control and trial groups were slightly increased to (23.1 ± 28.4) and (19.6 ± 23.5) µg/L, respectively, with no statistically significant differences in between (P >0.05). Karnofsky, FACT-P and TCM symptoms scores were all markedly improved in the trial group after 12 weeks of treatment (P <0.05) and remained stable at 24 weeks, but not in the control group either at 12 or at 24 weeks (P >0.05). CONCLUSIONS: TCM Fuyang Huayu Prescription combined with endocrine therapy and chemotherapy is effective for CRPC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Anilidas/administração & dosagem , Antineoplásicos Hormonais/uso terapêutico , Docetaxel , Esquema de Medicação , Gosserrelina/administração & dosagem , Humanos , Masculino , Nitrilas/administração & dosagem , Prednisona/administração & dosagem , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue , Taxoides/administração & dosagem , Compostos de Tosil/administração & dosagem , Resultado do Tratamento
7.
Zhonghua Nan Ke Xue ; 23(9): 828-837, 2017 Sep.
Artigo em Zh | MEDLINE | ID: mdl-29726666

RESUMO

OBJECTIVE: To explore the apoptosis-inducing effect of the Chinese medicinal compound CFF-1 on prostate cancer cells and its related molecular mechanisms. METHODS: Normal prostate WPMY-1 cells and prostate cancer LNCaP, CWR22Rv1, PC3 and DU145 cells were treated in dehydrated alcohol with CFF-1 at 0, 2, 5, or 10 mg/ml for 24 hours. Then the viability of the prostate cells was detected by morphological observation, MTT and CCK-8 assay, nuclear condensation and disruption measured by DAPI staining, the cell cycle and apoptosis calculated by flow cytometry, the activity of the PI3K/AKT/FOXO1 signaling pathway and the expressions of its downstream apoptosis- and cycle-related proteins determined by Western blot. RESULTS: CFF-1 significantly arrested the cell cycle in the G1 phase, decreased the cell viability and increased the nuclear condensation and disruption in a dose-dependent manner, and elevated the apoptosis rate of prostate cancer cells. At the molecular level, CFF-1 dose-dependently reduced the activity of the PI3K/AKT signaling pathway and phosphorylation of the FOXO1 protein, increased the transcription activity of FOXO1, and eventually regulated the expressions of cell apoptosis- and cycle-related genes. CONCLUSIONS: The Chinese medicinal compound CFF-1 can significantly inhibit the growth, arrest the cycle, and induce the apoptosis of prostate cancer cells by decreasing the activity of the PI3K/AKT/FOXO1 signaling pathway, which suggests its potential clinical application value in the treatment of prostate cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Proteína Forkhead Box O1/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Divisão Celular , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Humanos , Masculino , Proteínas de Neoplasias/metabolismo , Fosforilação , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Transdução de Sinais/efeitos dos fármacos
8.
Virol J ; 12: 44, 2015 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-25889104

RESUMO

BACKGROUND: Since late 2011, cases of suspected canine pseudorabies have increased in north China with the outbreak of swine pseudorabies in the same area, but the pathogenesis of canine Pseudorabies virus (PRV) infections in China is poorly understood. In this study, we investigated the pathogenesis of canine pseudorabies. METHODS: The pathological changes in 13 dogs that died of natural PRV infections (confirmed by pathogen detection) during 2011-2013 in Beijing were evaluated. An experimental study was also conducted in which healthy adult beagle dogs were administered PRV isolate BJ-YT by subcutaneous injection. The dog tissues were subjected to gross and microscopic examinations and immunohistochemical analysis and the dogs' serum cardiac troponin-I (cTn-I) was measured. RESULTS: Systemic hemorrhage and/or congestion were the most marked pathological changes in both the naturally and experimentally PRV-infected dogs. Macroscopically, the major lesions consisted of petechiae and ecchymoses in both the endocardium and epicardium, thrombi in the mitral valves, hemorrhage in the lungs and thymus, and incomplete contraction of the spleen. Microscopically, the major histopathological findings were systemic hemorrhage and congestion, nonsuppurative ganglioneuritis (in the experimentally infected dogs, unexamined in the naturally PRV-infected dogs), brainstem encephalitis (in the naturally infected dogs), necrosis or exudation in the myocardium, and lymphoid depletion in many lymphoid organs and tissues. Viral antigens were only detected in the brainstems and peripheral ganglia of the infected dogs. Serum cTn-I was significantly higher in the experimentally PRV-infected dogs with myocardial lesions than in the dogs without myocardial lesions. CONCLUSIONS: Based on these results, we conclude that virally induced systemic hemorrhage, peripheral nervous system pathology, and/or cardiac injury can individually or collectively cause death in PRV-infected dogs. The respiratory signs of the disease are attributed to cardiogenic lesions.


Assuntos
Doenças do Cão/virologia , Herpesvirus Suídeo 1/fisiologia , Pseudorraiva/virologia , Animais , China , Doenças do Cão/patologia , Cães , Feminino , Herpesvirus Suídeo 1/genética , Herpesvirus Suídeo 1/isolamento & purificação , Fígado/patologia , Fígado/virologia , Pulmão/patologia , Pulmão/virologia , Masculino , Pseudorraiva/patologia , Timo/patologia , Timo/virologia
9.
Zhonghua Nan Ke Xue ; 21(9): 788-91, 2015 Sep.
Artigo em Zh | MEDLINE | ID: mdl-26552210

RESUMO

OBJECTIVE: To explore the antitumoral effect of indirubin on androgen-independent prostate cancer PC-3 cells and its possible mechanisms. METHODS: We measured the inhibitory effect of indirubin on the proliferation of prostate cancer PC-3 cells using MTT assay, detected their cell cycles by flow cytometry, and determined the expressions of the cell cycle regulatory protein cyclin D1 and its related downstream gene c-myc by Western blot. RESULTS: The viability of the PC-3 cells was significantly decreased by indirubin in a concentration-dependent manner, reduced to 52. 2% and 13. 6% at 5 and 10 µmol/L, respectively. The cell cycle of the PC-3 cells was markedly inhibited by indirubin at 5 µmol/L, with the cells remarkably increased in the G0 and G1 phases and decreased in the S and G2/M phases. Meanwhile, indirubin also inhibited the expressions of cyclin D1 and c-myc in the Wnt signaling pathway. CONCLUSION: Indirubin can suppress the proliferation of androgen-independent prostate cancer PC-3 cells, which may be associated with its inhibitory effect on the cell cycle and Wnt signaling pathway.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Ciclina D1/metabolismo , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Antibióticos Antineoplásicos/administração & dosagem , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Corantes , Relação Dose-Resposta a Droga , Genes myc , Humanos , Indóis/administração & dosagem , Indóis/farmacologia , Masculino , Neoplasias de Próstata Resistentes à Castração/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Sais de Tetrazólio , Tiazóis
10.
J Hazard Mater ; 474: 134842, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38852246

RESUMO

Heterogeneous catalytic ozonation (HCO) enables the destruction of organic pollutants in wastewater via oxidation by powerful hydroxyl radicals (·OH). However, the availability of short-lived ·OH in aqueous bulk is low in practical treatment scenarios due to mass transfer limitations and quenching of water constituents. Herein, we overcome these challenges by loading MgO catalysts inside the pores of a tubular ceramic membrane (denoted as CCM) to confine ·OH within the nanopores and achieve efficient pollutant removal. When the pore size of the membrane was reduced from 1000 to 50 nm, the removal of ibuprofen (IBU) by CCM was increased from 49.6 % to 90.2 % due to the enhancement of ·OH enrichment in the nanospace. In addition, the CCM exhibited high catalytic activity in the presence of co-existing ions and over a wide pH range, as well as good self-cleaning ability in treating secondary wastewater. The experimental results revealed that ·OH were the dominant reactive oxygen species (ROS) in pollutant degradation, while surface hydroxyl groups were active sites for the generation of ·OH via ozone decomposition. This work provides a promising strategy to enhance the utilization of ·OH in HCO for the efficient degradation of organic pollutants in wastewater under spatial confinement.

11.
Anal Sci ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38814563

RESUMO

Detecting the concentration of reactive dyes and their hydrolyzed products is essential for controlling the dyeing process and is an important guide for upgrading and improving textile dyeing technology. In this study, capillary electrophoresis (CE) with UV detection was for the first time applied in a real trichromatic dyeing process to provide qualitative and quantitative determination of reactive dyes and their hydrolyzed forms. Here, three original reactive dyes (SES-Cl-red-195, SES-Cl-yellow-145, and SES-Cl-blue-194), their vinyl sulfone forms (VS-Cl-red-195, VS-Cl-yellow-145, and VS-Cl-blue-194), and complete hydrolyzed forms (HES-OH-red-195, HES-OH-yellow-145, and HES-OH-blue-194) could be baseline separated in our developed BGE comprised of 10.0 mol/L Na2B4O7, 15% (V/V) ACN at pH 8.50 that adjusted by 0.50 mol/L H3BO3. The LODs (S/N = 3) of nine analytes ranged from 0.3 to 1.3 mg/L, and high sensitivities were achieved with UV detection. The RSDs of peak area and migration time were in the ranges of 1.4-3.8% and 0.39-1.29%, which indicated the CE methods were reliable for studying different dye forms in complex dye baths, and for evaluating dyeing process quality. Thus, the percentage of dye-uptake in single and trichromatic combination dyes was calculated based on the concentration of the original and their vinyl sulfone and hydrolyzed forms, and the result was consistent with the traditional UV-Vis method.

12.
J Mater Chem B ; 12(19): 4642-4654, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38592460

RESUMO

The therapeutic efficacy of Fenton or Fenton-like nanocatalysts is usually restricted by the inappropriate pH value and limited concentration of hydrogen peroxide (H2O2) at the tumor site. Herein, calcium carbonate (CaCO3)-mineralized cobalt silicate hydroxide hollow nanocatalysts (CSO@CaCO3, CC) were synthesized and loaded with curcumin (CCC). This hybrid system can simultaneously realize nanocatalytic therapy, chemotherapy and calcium overload. With the stabilization of liposomes, CCC is able to reach the tumor site smoothly. The CaCO3 shell first degrades in an acidic tumor environment, releasing Cur and Ca2+, and the pH value of the tumor is increased simultaneously. Then the exposed CSO catalyzes the Fenton-like reaction to convert H2O2 into ˙OH and enhances the cytotoxicity of curcumin (Cur) by catalytically oxidizing it to a ˙Cur radical. Curcumin not only induces the chemotherapy effect but also serves as a nucleophilic ligand and an electron donor in the catalytic system, enhancing the Fenton-like activity of CCC by electron transfer. In addition, calcium overload also amplifies the efficacy of ROS-based therapy. In vitro and in vivo results show that CCC exhibited an excellent synergistic tumor inhibition effect without any clear side effect. This work proposes a novel concept of nanocatalytic therapy/chemotherapy synergistic mechanism by the ligand-induced enhancement of Fenton-like catalytic activity, and inspires the construction of combined therapeutic nanoplatforms and multifunctional nanocarriers for drug and ion delivery in the future.


Assuntos
Antineoplásicos , Cálcio , Cobalto , Curcumina , Nanopartículas , Curcumina/química , Curcumina/farmacologia , Cobalto/química , Cobalto/farmacologia , Humanos , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Camundongos , Cálcio/química , Cálcio/metabolismo , Nanopartículas/química , Catálise , Carbonato de Cálcio/química , Ligantes , Tamanho da Partícula , Camundongos Endogâmicos BALB C , Portadores de Fármacos/química , Ensaios de Seleção de Medicamentos Antitumorais , Proliferação de Células/efeitos dos fármacos , Feminino , Sobrevivência Celular/efeitos dos fármacos , Linhagem Celular Tumoral
13.
Adv Mater ; : e2404901, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38723206

RESUMO

Intrinsic characteristics of microorganisms, including non-specific metabolism sites, toxic byproducts, and uncontrolled proliferation constrain their exploitation in medical applications such as tumor therapy. Here, the authors report an engineered biohybrid that can efficiently target cancerous sites through a pre-determined metabolic pathway to enable precise tumor ablation. In this system, DH5α Escherichia coli is engineered by the introduction of hypoxia-inducible promoters and lactate oxidase genes, and further surface-armored with iron-doped ZIF-8 nanoparticles. This bioengineered E. coli can produce and secrete lactate oxidase to reduce lactate concentration in response to hypoxic tumor microenvironment, as well as triggering immune activation. The peroxidase-like functionality of the nanoparticles extends the end product of the lactate metabolism, enabling the conversion of hydrogen peroxide (H2O2) into highly cytotoxic hydroxyl radicals. This, coupled with the transformation of tirapazamine loaded on nanoparticles to toxic benzotriazinyl, culminates in severe tumor cell ferroptosis. Intravenous injection of this biohybrid significantly inhibits tumor growth and metastasis.

14.
J Colloid Interface Sci ; 637: 207-215, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36701866

RESUMO

HYPOTHESIS: The key to prepare a mesostructured porous material by a soft-template route coupled to a colloidal sol-gel process is to control the surfactant-colloid interface. In the case of tetravalent actinide ions, their high reactivity in aqueous media always leads to uncontrolled and irreversible condensation. The addition of a complexing agent to the sol may moderate these reactions and enhances the interaction between the colloids and the surfactant to in fine prepare a mesostructured nanoporous actinide oxide material. EXPERIMENTS: Several colloidal sols were prepared without and with formic acid as complexing agent by varying the molar ratios between thorium, carboxylic surfactant and pH. Small and Wide Angle X-ray Scattering were used to characterize the nature of the colloids, their interaction with the surfactant and the final ThO2 materials. FINDINGS: Depending on the colloid nature, hexagonal or worm-like hybrid mesophase is formed. The thermal treatment of the worm-like mesophase with a sufficient amount of Th-formic acid hexameric species coated at the surface of surfactant micelles generates micrometric ThO2 nanofibers. This material having an accessible porosity opens new perspectives to be impregnated with minor actinide solutions offering a promising safety method for the fabrication of mixed oxide nuclear fuel and the minor actinide transmutation.

15.
Adv Sci (Weinh) ; 10(23): e2207194, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37314157

RESUMO

A biohybrid therapeutic system, consisting of responsive materials and living microorganisms with inter-cooperative effects, is designed and investigated for tumor treatment. In this biohybrid system, S2 O3 2- -intercalated CoFe layered double hydroxides (LDH) are integrated at the surface of Baker's yeasts. Under the tumor microenvironment, functional interactions between yeast and LDH are effectively triggered, resulting in S2 O3 2- release, H2 S production, and in-situ generation of highly catalytic agents. Meanwhile, the degradation of LDH in the tumor microenvironment induces the exposure of the surface antigen of yeast, leading to effective immune activation at the tumor site. By virtue of the inter-cooperative phenomena, this biohybrid system exhibits significant efficacy in tumor ablation and strong inhibition of recurrence. This study has potentially offered an alternative concept by utilizing the metabolism of living microorganisms and materials in exploring effective tumor therapeutics.


Assuntos
Hidróxidos , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Hidróxidos/metabolismo
16.
Anal Chim Acta ; 1252: 341046, 2023 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-36935150

RESUMO

Whole-cell biosensors are an important class of analytical tools that offer the advantages of low cost, facile operation, and unique reproduction/regeneration ability. However, it has always been quite challenging to expand the sensing spectrum of the host. Here, a new approach to extend the cell sensing spectrum with biomineralized nanoparticles is developed. The nano-biohybrid design comprise biomineralized FeS nanoparticles firmly anchored onto the bacterium, Shewanella oneidensis MR-1, wherein the nanoparticles are wired to the cellular electron transfer machinery (MtrCAB/OmcA) of the bacterium, forming an artificial cyborgian redox machinery consisting of FeS-MtrCAB/OmcA-FccA. Strikingly, with this cyborgian redox machinery, the sensing spectrum of FeS hybridized S. oneidensis MR-1 cell is successfully expanded to enable whole-cell electrochemical detection of Vitamin B12, while an unhybridized native cell is incapable of sensing. This proof-of-concept nano-biohybrid design offers a new perspective on manipulating the microbial toolkit for an expanded sensing spectrum in whole-cell biosensors.


Assuntos
Nanopartículas , Shewanella , Oxirredução , Transporte de Elétrons
17.
J Appl Crystallogr ; 55(Pt 5): 1154-1163, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36249511

RESUMO

The characterization of nanoporous powders of highly absorbing compounds by small-angle X-ray scattering (SAXS) involves overcoming several difficulties before quantitative information related to the porous texture, such as the specific surface and the porous volume, can be derived. In this article, first, the contribution of the grain facet reflectivity and scattering from the bulk of a grain with the density of ThO2, a highly absorbing material, were calculated. Microporous ThO2 powder having micrometric grain size was characterized, in which the scattering signal is predominant. A high-resolution synchrotron instrument was used in order to cover a wider q range and minimize the absorption effect, and the results were compared with those obtained using a laboratory X-ray source. Concerning the absorption problem existing with a laboratory X-ray source, a new and robust experimental method was proposed to correctly determine the scattering intensity of the highly absorbing granular samples on an absolute scale. This method allows one to calculate accurately the porous volume and the specific surface via Porod's law and the invariant using a laboratory SAXS instrument. This last result opens new perspectives for the characterization of the volume and the specific surface of highly absorbing actinide oxide powders.

18.
J Mater Chem B ; 10(23): 4501-4508, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35615958

RESUMO

Peroxynitrite anion (ONOO-), a product derived from reaction between reactive oxygen species (ROS) and nitric oxide (NO), is considered to be a more toxic reactive species than most ROS for cancer photodynamic therapy (PDT). To promote the PDT effect, a viable method is to develop rational strategies for efficient ONOO- generation at targeted tumor sites. Herein, a heterostructure nanocomposite containing ZnO-coated lanthanide nanoparticles (LnNPs) is reported for ONOO--based PDT. In this nanocomposite, Nd3+-doped LnNPs are employed to realize efficient NIR-light-triggered ROS generation by activating the triplet state of chlorin-e6 (Ce6) photosensitizers via a direct lanthanide-to-triplet sensitization mechanism. Meanwhile, ZnO in the composite catalyzes the decomposition of S-nitrosoglutathione (GSNO) to generate NO in the tumor microenvironment. The coupled system allows the combination of photo-induced ROS and NO to produce ONOO-, leading to drastically promoted cancer cell apoptosis and tumor growth inhibition. This study establishes a new apoptosis-inducing PDT agent, which is potentially active in drug resistant malignancies.


Assuntos
Elementos da Série dos Lantanídeos , Nanopartículas Metálicas , Neoplasias , Fotoquimioterapia , Óxido de Zinco , Ânions/uso terapêutico , Humanos , Elementos da Série dos Lantanídeos/farmacologia , Elementos da Série dos Lantanídeos/uso terapêutico , Neoplasias/tratamento farmacológico , Ácido Peroxinitroso , Fotoquimioterapia/métodos , Espécies Reativas de Oxigênio , Microambiente Tumoral
19.
Micromachines (Basel) ; 13(2)2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35208436

RESUMO

Convergence of communication and sensing is highly desirable for future wireless systems. This paper presents a converged millimeter-wave system using a single orthogonal frequency division multiplexing (OFDM) waveform and proposes a novel method, based on the zero-delay shift for the received echoes, to extend the sensing range beyond the cyclic prefix interval (CPI). Both simulation and proof-of-concept experiments evaluate the performance of the proposed system at 97 GHz. The experiment uses a W-band heterodyne structure to transmit/receive an OFDM waveform featuring 3.9 GHz bandwidth with quadrature amplitude modulation (16-QAM). The proposed approach successfully achieves a range resolution of 0.042 m and a speed resolution of 0.79 m/s with an extended range, which agree well with the simulation. Meanwhile, based on the same OFDM waveform, it also achieves a bit-error-rate (BER) 10-2, below the forward error-correction threshold. Our proposed system is expected to be a significant step forward for future wireless convergence applications.

20.
ACS Appl Mater Interfaces ; 14(47): 53165-53173, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36383750

RESUMO

The identification of new colloidal sol-gel routes for the preparation of actinide oxides, which have a homogeneous and accessible porosity that can easily be impregnated by any concentrated actinide solution, opens new perspectives for the preparation of homogeneous nuclear fuel for minor actinide transmutation. This homogeneity allows us to avoid "hot spot" formation due to the local accumulation of more fissile elements. Here, we report the preparation of macro-microporous ThO2 materials by a colloidal sol-gel route. Using a thorium salt with 6-aminocaproic acid as a complexing agent at a controlled pH, we were able to pilot the condensation of thorium hydroxo species forming colloids of tuned nanometric size and thus the sol stability. After a freeze-drying process to concentrate colloids and a thermal treatment allowing complexing agent removal and macroporosity formation by a brutal gas release during combustion, a loose packing of ThO2 nanoparticles with an ordered distribution of interparticular porosity and a fraction of nanometric crystallites, whose size depends on the initial colloidal size, were obtained. The sols, pastes, and final materials were characterized by small- and wide-angle X-ray scattering to determine the colloidal size and the final structure of the materials, which was also confirmed by transmission electron microscopy. The most promising material was finally successfully impregnated by a simulating minor actinide solution and thermally treated to prepare a mixed actinide oxide material. This safe technology, relying on the colloidal sol-gel process and the formulation of complex fluids forming tunable precursors, opens new perspectives for the reuse of nuclear waste solutions as new fuel.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA