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1.
Small ; : e2402474, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38822710

ABSTRACT

Although WO3 exhibits both electrochromic and photoelectrochemical (PEC) properties, there is no research conducted to investigate the correlation between them. The study herein reports the electrochromic enhancement of PEC activity on WO3. The electrochromic WO3 (e-WO3) exhibits a significantly enhanced activity for PEC water oxidation compared to raw WO3 (r-WO3), with a limiting photocurrent density three times that of r-WO3. The electrochromic enhancement of PEC activity is universal and independent of the type of cations inserted during electrochromism. Decoloring reduces the PEC activity but a simple re-coloring restores the activity to its maximum value. Electrochromism induces large amounts of oxygen vacancies and surface states, the former improving the electron density of WO3 and the latter facilitating the hole transfer across e-WO3/electrolyte interface. It is proved that the electrochromic enhancement effect is due to the significantly improved electron-hole separation efficiency and the charge transfer efficiency across the WO3/electrolyte interface.

2.
BMC Med Imaging ; 22(1): 44, 2022 03 14.
Article in English | MEDLINE | ID: mdl-35287607

ABSTRACT

PURPOSE: This study aims to further enhance a validated radiomics-based model for predicting pathologic complete response (pCR) after chemo­radiotherapy in locally advanced rectal cancer (LARC) for use in clinical practice. METHODS: A generalized linear model (GLM) to predict pCR in LARC patients previously trained in Europe and validated with an external inter-continental cohort (59 patients), was first examined with further 88 intercontinental patient datasets to assess its reproducibility; then new radiomics and clinical features, and validation methods were investigated to build a new model for enhancing the pCR prediction for patients admitted to our department. The patients were divided into training group (75%) and validation group (25%) according to their demographic. The least absolute shrinkage and selection operator (LASSO) logistic regression was used to reduce the dimensionality of the extracted features of the training group and select the optimal ones; the performance of the reference GLM and enhanced models was compared through the area under curve (AUC) of the receiver operating characteristics. RESULTS: The value of AUC of the reference model was 0.831 (95% CI, 0.701-0.961), and 0.828 (95% CI, 0.700-0.956) in the original and new validation cohorts, respectively, showing a reproducibility in the applicability of the GLM model. Eight features were found to be significant with LASSO and used to establish an enhanced model. The AUC of the enhanced model of 0.926 (95% CI, 0.859-0.993) for training, and 0.926 (95% CI, 0.767-1.00) for the validation group shows better performance than the reference model. CONCLUSIONS: The GLM model shows good reproducibility in predicting pCR in LARC; the enhanced model has the potential to improve prediction accuracy and may be a candidate in clinical practice.


Subject(s)
Neoplasms, Second Primary , Rectal Neoplasms , Chemoradiotherapy/methods , Humans , Magnetic Resonance Imaging/methods , Neoadjuvant Therapy/methods , Rectal Neoplasms/diagnostic imaging , Rectal Neoplasms/pathology , Rectal Neoplasms/therapy , Reproducibility of Results , Retrospective Studies
3.
J Transl Med ; 19(1): 372, 2021 08 30.
Article in English | MEDLINE | ID: mdl-34461927

ABSTRACT

BACKGROUND: Epidermal growth factor receptor (EGFR) and lanthionine synthetase C-like 2 (LanCL2) genes locate in the same amplicon, and co-amplification of EGFR and LANCL2 is frequent in glioblastoma. However, the prognostic value of LANCL2 and EGFR co-amplification, and their mRNA and protein expression in glioblastoma remain unclear yet. METHODS: This study analyzed the prognostic values of the copy number variations (CNVs), mRNA and protein expression of LANCL2 and EGFR in 575 glioblastoma patients in TCGA database and 100 glioblastoma patients in tumor banks of the Shenzhen Second People's Hospital and the Sun Yat-sen University Cancer Center. RESULTS: The amplification of LANCL2 or EGFR, and their co-amplification were frequent in glioblastoma of TCGA database and our tumor banks. A significant correlation was found between the CNVs of LANCL2 and EGFR (p < 0.001). CNVs of LANCL2 or EGFR were significantly correlated with IDH1/2 mutation but not MGMT promoter methylation. Multivariate analysis showed that LANCL2 amplification was significantly correlated with reduced overall survival (OS) in younger (< 60 years) glioblastoma patients of TCGA database (p = 0.043, HR = 1.657) and our tumor banks (p = 0.018, HR = 2.199). However, LANCL2 or EGFR amplification, and their co-amplification had no significant impact on OS in older (≥ 60 years) or IDH1/2-wild-type glioblastoma patients. mRNA and protein overexpression of LANCL2 and EGFR was also frequently found in glioblastoma. The mRNA expression rather than the protein expression of LANCL2 and EGFR was positively correlated (p < 0.001). However, mRNA or protein expression of EGFR and LANCL2 was not significantly correlated with OS of glioblastoma patients. The protein expression level of LANCL2, rather than EGFR, was elevated in relapsing glioblastoma, compared with newly diagnosed glioblastoma. In addition, the intracellular localization of LanCL2, not EGFR, was associated with the grade of gliomas. CONCLUSIONS: Taken together, amplification and mRNA overexpression of LANCL2 and EGFR, and their co-amplification and co-expression were frequent in glioblastoma patients. Our findings suggest that amplification of LANCL2 and EGFR were the independent diagnostic biomarkers for glioblastoma patients, and LANCL2 amplification was a significant prognostic factor for OS in younger glioblastoma patients.


Subject(s)
Brain Neoplasms , ErbB Receptors/genetics , Glioblastoma , Membrane Proteins/genetics , Phosphate-Binding Proteins/genetics , Aged , Biomarkers, Tumor/genetics , Brain Neoplasms/genetics , DNA Copy Number Variations/genetics , ErbB Receptors/metabolism , Glioblastoma/genetics , Humans , Mutation , Neoplasm Recurrence, Local , Prognosis , RNA, Messenger/genetics
4.
Cancer Cell Int ; 21(1): 24, 2021 Jan 06.
Article in English | MEDLINE | ID: mdl-33407478

ABSTRACT

BACKGROUND: Glioblastoma multiforme, the most aggressive and malignant primary brain tumor, is characterized by rapid growth and extensive infiltration to neighboring normal brain parenchyma. Our previous studies delineated a crosstalk between PI3K/Akt and JNK signaling pathways, and a moderate anti-glioblastoma synergism caused by the combined inhibition of PI3K p110ß (PI3Kß) isoform and JNK. However, this combination strategy is not potent enough. MLK3, an upstream regulator of ERK and JNK, may replace JNK to exert stronger synergism with PI3Kß. METHODS: To develop a new combination strategy with stronger synergism, the expression pattern and roles of MLK3 in glioblastoma patient's specimens and cell lines were firstly investigated. Then glioblastoma cells and xenografts in nude mice were treated with the PI3Kß inhibitor AZD6482 and the MLK3 inhibitor URMC-099 alone or in combination to evaluate their combination effects on tumor cell growth and motility. The combination effects on cytoskeletal structures such as lamellipodia and focal adhesions were also evaluated. RESULTS: MLK3 protein was overexpressed in both newly diagnosed and relapsing glioblastoma patients' specimens. Silencing of MLK3 using siRNA duplexes significantly suppressed migration and invasion, but promoted attachment of glioblastoma cells. Combined inhibition of PI3Kß and MLK3 exhibited synergistic inhibitory effects on glioblastoma cell proliferation, migration and invasion, as well as the formation of lamellipodia and focal adhesions. Furthermore, combination of AZD6482 and URMC-099 effectively decreased glioblastoma xenograft growth in nude mice. Glioblastoma cells treated with this drug combination showed reduced phosphorylation of Akt and ERK, and decreased protein expression of ROCK2 and Zyxin. CONCLUSION: Taken together, combination of AZD6482 and URMC-099 showed strong synergistic anti-tumor effects on glioblastoma in vitro and in vivo. Our findings suggest that combined inhibition of PI3Kß and MLK3 may serve as an attractive therapeutic approach for glioblastoma multiforme.

5.
Bioorg Med Chem Lett ; 30(2): 126816, 2020 01 15.
Article in English | MEDLINE | ID: mdl-31753698

ABSTRACT

A series of novel indole-based oxalamide and aminoacetamide derivatives were designed, synthesized, and evaluated for antiproliferative activities. Preliminary results revealed that compound 8g exhibited significant antiproliferative effect against PC-3, HeLa and HCT-116 cell lines. Flow cytometric analysis of the cell cycle demonstrated the compound 8g induced the cell cycle arrest at G2/M phase in HeLa cell lines. Immunocytochemistry revealed loss of intact microtubule structure in cells treated with 8g andinhibition of tubulinpolymerization. Additionally, molecular docking analysis suggested that 8g formed stable interactions in the colchicine-binding site of tubulin. These preliminary results demonstrated that a new class of novel indole-based oxalamide and aminoacetamide derivatives described in the investigation could be developed as potential scaffolds to new anticancer agents.


Subject(s)
Indoles/chemical synthesis , Tubulin Modulators/antagonists & inhibitors , Humans , Indoles/chemistry , Molecular Structure , Structure-Activity Relationship
6.
Bioorg Med Chem Lett ; 29(1): 22-27, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30448234

ABSTRACT

Based on our previous research, three series of new triazolylthioacetamides possessing 3,4,5-trimethoxyphenyl moiety were synthesized, and evaluated for antiproliferative activities and inhibition of tubulin polymerization. The most promising compounds 8b and 8j demonstrated more significant antiproliferative activities against MCF-7, HeLa, and HT-29 cell lines than our lead compound 6. Moreover, analogues 8f, 8j, and 8o manifested more potent antiproliferative activities against HeLa cell line with IC50 values of 0.04, 0.05 and 0.16 µM, respectively, representing 100-, 82-, and 25-fold improvements of the activity compared to compound 6. Furthermore, the representative compound, 8j, was found to induce significant cell cycle arrest at the G2/M phase in HeLa cell lines via a concentration-dependent manner. Meanwhile, compound 8b exhibited the most potent tubulin polymerization inhibitory activity with an IC50 value of 5.9 µM, which was almost as active as that of CA-4 (IC50 = 4.2 µM). Additionally, molecular docking analysis suggested that 8b formed stable interactions in the colchicine-binding site of tubulin.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Discovery , Thioacetamide/pharmacology , Tubulin Modulators/pharmacology , Tubulin/metabolism , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , HEK293 Cells , Humans , Molecular Docking Simulation , Molecular Structure , Polymerization/drug effects , Structure-Activity Relationship , Thioacetamide/chemical synthesis , Thioacetamide/chemistry , Tubulin Modulators/chemical synthesis , Tubulin Modulators/chemistry
7.
Bioorg Chem ; 88: 102914, 2019 07.
Article in English | MEDLINE | ID: mdl-30991193

ABSTRACT

A highly efficient method has been developed for the one-pot synthesis of substituted 3-amino-1H-indole and 3-amino-1H-7-azaindole derivatives starting from ethyl 2-cyanophenylcarbamate/ethyl 3-cyanopyridin-2-ylcarbamate, and α-bromoketones in good to excellent yields. All newly synthesized analogues were screened for their antiproliferative activities against four cancer cell lines. The most promising compound 8v demonstrated 13-, 5-, and 1.4-fold improvement compared to fluorouracil in inhibiting HeLa, HepG2, and MCF-7 cell proliferation with IC50 values of 3.7, 8.0, and 19.9 µM, respectively. Furthermore, 8v induced significant cell cycle arrest at the G2/M phase in HeLa cell lines via a concentration-dependent manner. These encouraging findings indicate that the common 3-amino-1H-7-azaindole is a very favorable scaffold for the design of novel anticancer small-molecule drugs.


Subject(s)
Antineoplastic Agents/pharmacology , Aza Compounds/pharmacology , Indoles/pharmacology , Antineoplastic Agents/chemical synthesis , Apoptosis/drug effects , Aza Compounds/chemical synthesis , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , G2 Phase Cell Cycle Checkpoints/drug effects , Humans , Indoles/chemical synthesis , Molecular Structure , Structure-Activity Relationship
8.
Bioorg Chem ; 92: 103260, 2019 11.
Article in English | MEDLINE | ID: mdl-31525523

ABSTRACT

As restricted CA-4 analogues, a novel series of [1,2,4]triazolo[1,5-a]pyrimidines possessing 3,4,5-trimethoxylphenyl groups has been achieved successfully via an efficient one-pot three-component reaction of 3-(3,4,5-trimethoxyphenyl)-1H-1,2,4-triazol-5-amine, 1,3-dicarbonyl compounds and aldehydes. Initial biological evaluation demonstrated some of target compounds displayed potent antitumor activity in vitro against three cancer cell lines. Among them, the most highly active analogue 26 inhibited the growth of HeLa, and A549 cell lines with IC50 values at 0.75, and 1.02 µM, respectively, indicating excellent selectivity over non-tumoural cell line HEK-293 (IC50 = 29.94 µM) which suggested that the target compounds might possess a high safety index. Moreover, cell cycle analysis illustrated that the analogue 26 significantly induced HeLa cells arrest in G2/M phase, meanwhile the compound could dramatically affect cell morphology and microtubule networks. In addition, compound 28 exhibited potent anti-tubulin activity with IC50 values of 9.90 µM, and molecular docking studies revealed the analogue occupied the colchicine-binding site of tubulin. These observations suggest that [1,2,4]triazolo[1,5-a]pyrimidines represent a new class of tubulin polymerization inhibitors and well worth further investigation aiming to generate potential anticancer agents.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Pyrimidines/pharmacology , Triazoles/pharmacology , Tubulin Modulators/pharmacology , Tubulin/metabolism , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , HEK293 Cells , Humans , Molecular Structure , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Structure-Activity Relationship , Triazoles/chemical synthesis , Triazoles/chemistry , Tubulin Modulators/chemical synthesis , Tubulin Modulators/chemistry , Tumor Cells, Cultured
9.
Med Sci Monit ; 24: 5820-5825, 2018 Aug 21.
Article in English | MEDLINE | ID: mdl-30127336

ABSTRACT

BACKGROUND The aim of this study was to compare early and long-term results of eversion carotid endarterectomy (e-CEA) and patch carotid endarterectomy (p-CEA). MATERIAL AND METHODS In a retrospective study, we collected data on 441 patients who underwent CEA (e-CEA=211 vs. p-CEA=230) between October 2009 and October 2015 at our institute. Economic costs, postoperative hospital days, use of shunts and antibiotics, early (30-day) complications, long-term restenosis, and mortality rates were compared between groups during 4 to 76 months of follow-up. RESULTS Patients in the p-CEA group had a significantly higher percentage of antibiotic use (58.3% vs. 27%, respectively; P0.05). Long-term complication, including stroke or heart attack, recurrent stenosis rate, and mortality rate, showed no difference between the 2 groups (all P>0.05). Kaplan-Meier analysis shows that the recurrent stenosis-free and survival rates were not significantly different between the 2 groups (P=0.867, P=0.177, respectively). CONCLUSIONS The adverse event rates of perioperative and long-term follow-up showed no significant difference between the e-CEA and p-CEA groups. Both e-CEA and p-CEA are effective for carotid artery stenosis.


Subject(s)
Carotid Stenosis/surgery , Endarterectomy, Carotid/methods , Aged , Carotid Stenosis/complications , Cost-Benefit Analysis , Endarterectomy, Carotid/adverse effects , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Myocardial Infarction/complications , Postoperative Complications/etiology , Retrospective Studies , Risk Factors , Stroke/etiology , Treatment Outcome
11.
Anticancer Drugs ; 27(5): 427-32, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27045782

ABSTRACT

Molecular targeted therapies (TT) are the cornerstone of metastatic renal cell carcinoma (RCC) treatment. There is a paucity of data on the safety of the radiotherapy (RT)-TT association in a sequential or a concomitant setting. The aim of the present study is to retrospectively assess the safety of the RT-TT association. From 2006 to 2014, data from 84 consecutive patients treated with RT and TT for metastatic RCC were retrospectively collected. RT-TT sequential and concomitant associations were, respectively, defined by a time interval of more than five TT half-lives and less than or equal to five TT half-lives between the last TT administration and RT initiation. Toxicities in the fields of RT were assessed systematically. As many patients received several TT and RT courses, 136 RT-TT associations were analyzed, with 66 sequential and 70 concomitant schemes. RT was mainly delivered on bone (75%) and brain metastases (14.7%). TT were tyrosine kinase inhibitors (73.5%), mTOR inhibitors (19.8%), and monoclonal antibodies (6.7%). With a median follow-up of 9.5 months, whatever the sequence, no grade≥4 toxicity was reported. Two grade 3 toxicities were reported with sequential (3%) and concomitant (2.9%) RT-TT, respectively. Sequential or concomitant RT-TT associations in metastatic RCC do not seem to cause major toxicity.


Subject(s)
Antineoplastic Agents/adverse effects , Carcinoma, Renal Cell/therapy , Kidney Neoplasms/therapy , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/adverse effects , Carcinoma, Renal Cell/secondary , Chemoradiotherapy/adverse effects , Female , Humans , Kidney Neoplasms/pathology , Male , Middle Aged , Molecular Targeted Therapy , Protein-Tyrosine Kinases/antagonists & inhibitors , Retrospective Studies , TOR Serine-Threonine Kinases/antagonists & inhibitors
12.
Bioorg Med Chem Lett ; 26(15): 3679-83, 2016 08 01.
Article in English | MEDLINE | ID: mdl-27287368

ABSTRACT

Based on our previous work, a series of novel 3-alkylsulfanyl-4-amino-1,2,4-triazole derivatives were designed, synthesized and evaluated for their antiproliferative activities. The results indicated that some compounds possessed significant antiproliferative activities against four cancer cell lines, HepG2, HCT116, PC-3, and Hela. Particularly, the most promising compound 8d displayed 184-, 18-, and 17-fold improvement compared to fluorouracil in inhibiting HCT116, Hela and PC-3 cell proliferation with IC50 values of 0.37, 2.94, and 31.31µM, respectively. Most interestingly, the compound did not affect the normal human embryonic kidney cells, HEK-293. Moreover, mechanistic investigation showed that the representative compound 8d induced apoptosis and blocked cell cycle in G2/M phase in Hela cells in a dose-dependent manner. These findings suggest that compound 8d may have potential to be developed as a promising lead for the design of novel anticancer small-molecule drugs.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Triazoles/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , HEK293 Cells , Humans , Molecular Structure , Structure-Activity Relationship , Triazoles/chemical synthesis , Triazoles/chemistry
13.
Phys Chem Chem Phys ; 19(1): 145-154, 2016 Dec 21.
Article in English | MEDLINE | ID: mdl-27918021

ABSTRACT

We previously reported that the hydrolysis of Ir3+ in homogeneous solution could be triggered by irradiation with light whose energy was larger than a threshold value. In this work, we demonstrated that, by introducing Fe2O3 particles into solution, the incident light energy-restriction for the photo-catalyzed hydrolysis could be broken and the hydrolysis occurred at the Fe2O3/solution interface. The photo-generated holes on the Fe2O3 surface played a key role in oxidizing Ir(iii) to Ir(iv) species and triggered the deposition of IrOx. We showed that this photo-catalyzed surface hydrolysis is a universal phenomenon that takes place on the surface of many n-type semiconductors such as Fe2O3, TiO2, and Ag3PO4. As IrOx is an efficient catalyst for oxygen evolution reaction, surface hydrolysis is a general, facile and efficient strategy to prepare semiconductor/IrOx composites, which can be used as anodic materials for photoelectrochemical water splitting.

14.
Oncology ; 89(5): 262-8, 2015.
Article in English | MEDLINE | ID: mdl-26303109

ABSTRACT

OBJECTIVE: Several studies have demonstrated that daily physical activity (PA) prevents the development of breast cancer. Our objective was to examine the relationship between PA and clinical and biological tumor characteristics in breast cancer patients in order to determine the impact of energy expenditure (EE) on tumor prognosis. METHODS: We pooled data from two prospective studies, including a total of 121 breast cancer patients. The measure of PA was done using the self-completion Population Physical Activity Questionnaire, which was answered by each patient. RESULTS: Ten patients harbored triple negative (TN) tumors. The mean body mass index (BMI) in the general population and in patients with TN tumors was 24.3 and 25.6, respectively. The mean daily EE (DEE) was 10,266 kJ×24 h(-1) in the general population and 11,212 kJ×24 h(-1) in patients with TN tumors. In the whole population, there was an inverse statistical correlation between BMI and DEE, rest, low PA, and high PA (p=0.0002, p=0.003, p<0001, and p=0.03, respectively). There was a positive correlation between negative estrogen receptor status and intensive PA (p=0.041) and DEE (p=0.007). For TN tumors, there was no significant correlation between BMI and categories of EE. CONCLUSIONS: Lifestyle (weight regulation, PA) should be adapted and personalized according to biological, clinical, and epidemiological characteristics of the tumors.


Subject(s)
Motor Activity/physiology , Triple Negative Breast Neoplasms/pathology , Body Mass Index , Female , Humans , Middle Aged , Prognosis , Prospective Studies , Receptors, Estrogen/metabolism , Triple Negative Breast Neoplasms/metabolism
15.
J Colloid Interface Sci ; 638: 54-62, 2023 May 15.
Article in English | MEDLINE | ID: mdl-36731218

ABSTRACT

Utilization of the infrared (IR) solar energy remains a challenging task for traditional photo(electro)catalysis. Taking advantage of the IR-thermal effect to facilitate sluggish electrocatalytic reactions emerges as a promising way to utilize the IR band of the solar spectrum. In this work, nickel foam (NF) supported NiCo2O4 nanoneedles (NF/NiCo2O4 NNs) were prepared to promote the oxygen evolution reaction (OER) via the IR-thermal effect, with the NF/NiCo2O4 NNs acting as both the IR absorbing antennae and the OER active anode. The potential required to deliver a current density of 200 mA cm-2 is negatively shifted from 1.618 V in the dark to 1.578 V under IR irradiation, and the Tafel slope is also decreased from 106 to 89 mV dec-1. We demonstrate that the enhancement of OER activity is due to the localized temperature rise under IR irradiation. We measured the electrochemical activation energy of OER on NF/NiCo2O4 with and without IR irradiation, and the results reveal that IR irradiation reduces the kinetic energy barrier of the OER by IR-thermal effect and then facilitates OER kinetics. This work highlights a new approach to utilizing the IR portion of the sunlight to produce renewable hydrogen energy via water splitting.


Subject(s)
Solar Energy , Sunlight , Water , Infrared Rays , Nickel , Oxygen
16.
ChemSusChem ; 16(2): e202201985, 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36394154

ABSTRACT

Exploiting highly active and low-cost materials as pH-universal electrocatalysts for the hydrogen evolution reaction (HER) and achieving high-purity hydrogen fuel is highly desirable but remains challenging. Herein, a novel type of coupled heterostructure was designed by simple electrodeposition followed by a sulfurization treatment. This hierarchical structure was composed of nickel sulfides (NiS, NiS2 , denoted as NiSx ) and oxygen-deficient tungsten oxide (WO2.9 ), which was directly grown on nickel foam (NF) as self-supporting electrodes (NiSx -WO2.9 /NF) for HER over a wide pH range. The systematic experimental characterizations confirmed that the material had abundant catalytic active sites, fast interfacial electron transfer ability, and strong electronic interaction, resulting in the optimized reaction kinetics for HER. Consequently, the NiSx -WO2.9 /NF catalyst required low overpotentials of 96 and 117 mV to reach current densities of 50 and 100 mA cm-2 in an alkaline medium, outperforming most of the reported non-noble metal-based materials. Moreover, this self-supported electrode exhibited impressive performance over a wide pH range, only requiring 220 and 304 mV overpotential at 100 mA cm-2 in 0.5 m H2 SO4 and 1 m phosphate-buffered saline electrolytes. This work may offer a new approach to the development of advanced pH-universal electrodes for hydrogen production.

17.
J Am Chem Soc ; 134(38): 15849-57, 2012 Sep 26.
Article in English | MEDLINE | ID: mdl-22957510

ABSTRACT

Electrocatalyst for oxygen reduction reaction (ORR) is crucial for a variety of renewable energy applications and energy-intensive industries. The design and synthesis of highly active ORR catalysts with strong durability at low cost is extremely desirable but remains challenging. Here, we used a simple two-step method to synthesize cobalt oxide/carbon nanotube (CNT) strongly coupled hybrid as efficient ORR catalyst by directly growing nanocrystals on oxidized multiwalled CNTs. The mildly oxidized CNTs provided functional groups on the outer walls to nucleate and anchor nanocrystals, while retaining intact inner walls for highly conducting network. Cobalt oxide was in the form of CoO due to a gas-phase annealing step in NH(3). The resulting CoO/nitrogen-doped CNT (NCNT) hybrid showed high ORR current density that outperformed Co(3)O(4)/graphene hybrid and commercial Pt/C catalyst at medium overpotential, mainly through a 4e reduction pathway. The metal oxide/carbon nanotube hybrid was found to be advantageous over the graphene counterpart in terms of active sites and charge transport. Last, the CoO/NCNT hybrid showed high ORR activity and stability under a highly corrosive condition of 10 M NaOH at 80 °C, demonstrating the potential of strongly coupled inorganic/nanocarbon hybrid as a novel catalyst system in oxygen depolarized cathode for chlor-alkali electrolysis.


Subject(s)
Cobalt/chemistry , Nanoparticles , Nanotubes, Carbon , Oxides/chemistry , Oxygen/chemistry , Catalysis , Electrochemical Techniques , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission
18.
Analyst ; 137(1): 145-52, 2012 Jan 07.
Article in English | MEDLINE | ID: mdl-22064849

ABSTRACT

A dual-region modified electrode was designed and fabricated by means of partitioned electrodeposition of gold and platinum nanoparticles on an indium tin oxide (ITO) conductive glass for dual-component electrochemical detection. The two differently modified regions were assigned to detect two analytes, separately and simultaneously. The gold nanoparticle modified ITO region (AuNPs/ITO) was used for glucose detection while the platinum nanoparticle modified ITO region (PtNPs/ITO) for nitrite detection. The glucose oxidation peak current at 0.10 V on AuNPs/ITO exhibited a linear dependence on the concentration of glucose and was used to determine the concentration of glucose in dual-detection. The nitrite reduction peak current at PtNPs/ITO showed a nonlinear dependence on the concentration of nitrite. A theoretical model combining the adsorption-controlled and the mass-transfer-controlled kinetics was proposed to quantitatively describe the nonlinear behavior. Though the presence of glucose interfered with the electrochemical detection of nitrite, it was demonstrated that the influence of glucose on nitrite detection can be corrected. On the basis of the proposed theoretical model, the simultaneous dual-detection of glucose and nitrite was accomplished at ITO electrodes partitionally modified with AuNPs and PtNPs.

19.
Front Oncol ; 12: 920443, 2022.
Article in English | MEDLINE | ID: mdl-36106119

ABSTRACT

Adaptive radiotherapy performed on the daily magnetic resonance imaging (MRI) is an option to improve the treatment quality. In the adapt-to-shape workflow of 1.5-T MR-Linac, the contours of structures are adjusted on the basis of patient daily MRI, and the adapted plan is recalculated on the MRI-based synthetic computed tomography (syCT) generated by bulk density assignment. Because dosimetric accuracy of this strategy is a priority and requires evaluation, this study aims to explore the usefulness of adding an assessment of dosimetric errors associated with recalculation on syCT to the clinical workflow. Sixty-one patients, with various tumor sites, treated using a 1.5-T MR-Linac were included in this study. In Monaco V5.4, the target and organs at risk (OARs) were contoured, and a reference CT plan that contains information about the outlined contours, their average electron density (ED), and the priority of ED assignment was generated. To evaluate the dosimetric error of syCT caused by the inherent approximation within bulk density assignment, the reference CT plan was recalculated on the syCT obtained from the reference CT by forcing all contoured structures to their mean ED defined on the reference plan. The dose-volume histogram (DVH) and dose distribution of the CT and syCT plan were compared. The causes of dosimetric discrepancies were investigated, and the reference plan was reworked to minimize errors if needed. For 54 patients, gamma analysis of the dose distribution on syCT and CT show a median pass rate of 99.7% and 98.5% with the criteria of 3%/3 mm and 2%/2 mm, respectively. DVH difference of targets and OARs remained less than 1.5% or 1 Gy. For the remaining patients, factors (i.e., inappropriate ED assignments) influenced the dosimetric agreement of the syCT vs. CT reference DVH by up to 21%. The causes of the errors were promptly identified, and the DVH dosimetry was realigned except for two lung treatments for which a significant discrepancy remained. The recalculation on the syCT obtained from the planning CT is a powerful tool to assess and decrease the minimal error committed during the adaptive plan on the MRI-based syCT.

20.
Swiss Med Wkly ; 151: w30034, 2021 12 06.
Article in English | MEDLINE | ID: mdl-34964579

ABSTRACT

BACKGROUND: This retrospective study was conducted to: (1) provide more modern data on real-life local management of metastatic rectal cancer; (2) compare therapeutic strategies; and (3) identify prognostic factors of local failure, overall survival and progression-free survival. METHODS: Data about efficacy and acute toxicity were collected. Patients were diagnosed with metastatic rectal cancer between 2004 and 2015, and were treated at least with radiotherapy. Local failure, overall survival and progression-free survival were correlated with patient, tumour and treatment characteristics using univariate and multivariate analyses. RESULTS: Data of 148 consecutive patients with metastatic rectal cancer were analysed. Median follow-up was 19 months. Median overall survival was 16 months. All patients received local radiotherapy, with a median equivalent 2 Gy per fraction dose of 47.7 Gy. Rectal surgery was performed in 97 patients (65.6%). The majority of patients (86/97, 88.7%) received pre-operative chemoradiation. In multivariate analysis, rectal surgery was found to be the only independent predictor of increased overall survival (24.6 vs 7.1 months, p <0.001). Of the patients undergoing surgical treatment, 22.8% presented with significant complications that required a delay of systemic treatment. Grade 3-4 acute radiation therapy-related toxicities were observed in 6.1% of patients, mainly gastrointestinal toxicities (5.4%). CONCLUSION: Rectal surgery was a key predictive factor of increased progression-free survival and overall survival in patients receiving at least local radiotherapy. In our series of real-life patients, local surgery and radiation seemed as well tolerated as reported in selected phase III non-metastatic rectal cancer patients. These data suggested that local management could be beneficial for metastatic rectal cancer patients.


Subject(s)
Digestive System Surgical Procedures , Rectal Neoplasms , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Humans , Neoplasm Recurrence, Local/drug therapy , Neoplasm Staging , Prognosis , Rectal Neoplasms/therapy , Retrospective Studies
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