Carbon quantum dots-decorated TiO2/g-C3N4 film electrode as a photoanode with improved photoelectrocatalytic performance for 1,4-dioxane degradation.

In this study, carbon quantum dots (CQDs) were used to decorate a TiO2/g-C3N4 (TCN) film electrode. The morphological, optical, and electrochemical properties of the TiO2/g-C3N4/CQDs nanorod arrays (TCNC NRAs) film were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS). The improved optical properties, photoelectrochemical properties and photoelectrocatalytic (PEC) performance of photoanode can be observed by doping CQDs onto the TCN NRAs film. Compared with TiO2 NRAs and TCN NRAs, the narrower band gap of 2.47 eV and longer lifetime of photoinduced electron-hole pairs were observed in the TCNC NRAs. Under visible light irradiation and a bias voltage of 1.2 V, the photocurrent density and 1,4-dioxane (1,4-D) removal rate of PEC process with TCNC NRAs electrode reached 0.16 mA/cm2 and 77.9%, respectively, which was 2.5 times and 1.5 times of that with TCN NRAs electrode. TCNC NRAs electrode could keep >75% of the 1,4-D removal rate during five cycles tests. High PEC performance with TCNC NRAs electrode could be attributed to the enhanced charge separation and the change of electron transfer mechanism from typical heterojunction to Z-scheme, which may increase the active species production and change the dominant reactive species from O2·- to ·OH. Our experimental results should be useful for studying the degradation of 1,4-D and developing efficient PEC materials.

Study of the simulated sunlight photolysis mechanism of ketoprofen: the role of superoxide anion radicals, transformation byproducts, and ecotoxicity assessment.

The aim of this study was to investigate the photolysis mechanism of ketoprofen (KET) under simulated sunlight. The results demonstrated that the photolysis of KET aligned well with pseudo first-order kinetics. Radical scavenging experiments and dissolved oxygen experiments revealed that the superoxide anion radical (O2˙-) played a primary role in the photolytic process in pure water. Bicarbonate slightly increased the photodegradation of KET through generating carbonate radicals, while DOM inhibited the photolysis via both attenuating light and competing radicals. Moreover, Zhujiang river water inhibited KET phototransformation. Potential KET degradation pathways were proposed based on the identification of products using LC/MS/MS and GC/MS techniques. The theoretical prediction of reaction sites was derived from Frontier Electron Densities (FEDs), which primarily involved the KET decarboxylation reaction. The ecotoxicity of the treated solutions was evaluated by employing Daphnia magna and V. fischeri as biological indicators. Ecotoxicity was also hypothetically predicted through the "ecological structure-activity relationship" (ECOSAR) program, which revealed that toxic products might be generated during the photolysis process.

Photocatalytic degradation of clofibric acid by g-C3N4/P25 composites under simulated sunlight irradiation: The significant effects of reactive species.

Pharmaceutically emerging micropollutants have become an environmental concern in recent years. In the present paper, the reactive species (RSs)-induced degradation mechanism of clofibric acid (CA) was investigated using a newly sunlight-driven g-C3N4/P25 photocatalyst. A very low g-C3N4 content of 8.0 weight percent resulted in a 3.36 and a 2.29 times faster reaction rate for CA photodegradation than for pristine g-C3N4 and P25, respectively. Electron spin resonance and quenching experiments demonstrated the participation of HO, h+, e-, 1O2 and O2·- in the photocatalytic system, and the contribution rates were calculated to 73.3%, 15.3%, 5.1%, 6.7% and 33.1%, respectively. According to the pulse radiolysis measurements and the competitive kinetics approaches, the bimolecular reaction rate constants for HO, e-, and 1O2 with CA were (8.47 ± 0.33) × 109 M-1s-1, (6.41 ± 0.48) × 109 M-1s-1 and (6.6 ± 0.37) × 106 M-1s-1, respectively. RSs were found to significantly influence the degradation of CA, and the degradation pathways occurred primarily via e- reduction, HO addition and 1O2 attack reactions on the basis of mass spectrometry and theoretical calculations.

Residual ß-Cell Function Predicts Clinical Response After Autologous Hematopoietic Stem Cell Transplantation.

UNLABELLED: New strategies of autologous hematopoietic stem cell transplantation (auto-HSCT) have gained much interest for the treatment of type 1 diabetes mellitus. However, assessing the clinical response and residual ß-cell function still has limitations. The aim of the study was to select the optimal quantitative index to assess pre-existing ß-cell function and to explore its predictive function for clinical response after auto-HSCT therapy. In this study, all of the patients who had undergone auto-HSCT were clustered into a responder group (Δß-score > 0) and a nonresponder group (Δß-score ≤ 0). We compared their quantitative metabolic indexes at baseline and performed receiver-operating characteristic (ROC) analysis to analyze the correlations between the indexes and clinical response. Kaplan-Meier analysis was conducted to compare the cumulative response durations in each quartile of the selected indexes. In an average of 15.13 ± 6.15 months of follow-up, 44 of 112 patients achieved a clinical response. The responder group had lower levels of fasting plasma glucose and quantitative insulin sensitivity check index (QUICKI) but higher levels of fasting C-peptide, fasting insulin, and homeostasis model assessments for insulin resistance (HOMA-IR). ROC analysis showed that HOMA-IR had the largest area under the curve (0.756), which was similar to that of QUICKI. Kaplan-Meier analysis further confirmed that the third quartile (1.3371-1.7018) of HOMA-IR or the second quartile (0.3523-0.3657) of QUICKI was preferential for a prolonged response. In conclusion, HOMA-IR and QUICKI could be optimal measurements for ß-cell reserves, and they were predictive for the clinical response after auto-HSCT. SIGNIFICANCE: The ß-score was comprehensive and reliable in evaluating clinical response after autologous hematopoietic stem cell transplantation (HSCT). The homeostasis model assessments for insulin resistance and the quantitative insulin sensitivity check index could serve as precise assessments for residual ß-cell function and good predictors of clinical response. They might be used to select optimal clinical trial participants or predict the clinical response after auto-HSCT.

Predictive factors for prolonged remission after autologous hematopoietic stem cell transplantation in young patients with type 1 diabetes mellitus.

BACKGROUND AIMS: Autologous hematopoietic stem cell transplantation (auto-HSCT) followed by immunoablation is a promising therapy for type 1 diabetes mellitus (T1DM) treatment due to the immunosuppression and immunomodulation mechanisms. Indeed, a considerable number of patients have been able to discontinue insulin use with this treatment. However, nonresponse and relapse occur after auto-HSCT. It is important to select the patients who can potentially benefit from this treatment, but the factors that might influence the therapeutic outcome are unclear. The objective of this study was to explore the predictors for prolonged remission after auto-HSCT therapy. METHODS: The data for this study were extracted from an open-label prospective study, which was performed to treat new-onset T1DM patients with auto-HSCT. The 128 patients were categorized into insulin-free (IF) or insulin-dependent (ID) groups according to their response to treatment during the follow-up. We compared the baseline data of the two groups and explored possible prognostic factors and their odd ratios (ORs) with univariate analysis and multivariate logistic regression. Receiver operating characteristic curves (ROC) were performed to test the model discrimination function. RESULTS: During a follow-up of 28.5 ± 8.3 months, 71 of 128 patients in the IF group discontinued insulin use, whereas 57 of 128 patients in the ID group did not decrease their insulin dose or resumed insulin treatment after a transient remission. Multivariate logistic regression analysis demonstrated that prolonged remission was positively correlated with fasting C-peptide level (OR = 2.60, 95% confidence interval [CI]: 1.16-5.85) but negatively correlated with onset age (OR = 0.36, 95% CI: 0.14-0.88) and tumor necrosis factor-α levels (OR = 0.32, 95% CI: 0.14-0.73). ROC analysis confirmed the combined predictive function of these three variables (AUC = 0.739, 95% CI: 0.655-0.824). CONCLUSIONS: Age and fasting C-peptide and tumor necrosis factor-α levels were identified as possible predictors for prolonged remission following auto-HSCT therapy.

BMP-7 improved proliferation and hematopoietic reconstitution potential of ex vivo expanded cord blood-derived CD34(+) cells.

Due to limited availability, ex vivo expansion is essential for clinical applications of hematopoietic stem cells (HSCs). Bone morphogenetic proteins (BMPs) play an important role in regulating hematopoiesis development. In this study, the effects of BMP-2 and BMP-7 at different doses on expansion, clonogenicity and differentiation of cord blood (CB)-derived CD34(+) cells were investigated in serum-free medium supplemented with stem cell factor, thrombopoietin and flt3-ligand (STF). Irradiated non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice were used as an animal model to assess the in vivo hematopoietic reconstitution potential of CB-derived CD34(+) cells treated by BMPs. It was demonstrated that the addition of BMP-7 at 5 ng/mL improved the proliferations of total cells, CD34(+) cells and CD34(+)CD38(-) cells without affecting the colony-forming ability of CD34(+) cells and component of lineage cells, while BMP-2 showed no effect on expanding these cells during the 10-day culture. Moreover, CB-derived CD34(+) cells cultured with STF and 5 ng/mL BMP-7 for 10 days were transplanted into irradiated NOD/SCID mice, and showed better engraftment and multi-lineage reconstitution ability compared with the cells cultured with STF alone. Together, 5 ng/mL BMP-7 was beneficial to ex vivo expansion of CB-derived CD34(+) cells for clinical purposes. The results may help improve the existing culture systems and achieve wider application of HSCs.