[en] Cerenkov luminescence imaging (CLI), as an emerging molecular imaging method, has been extensively studied in tumor imaging, therapy monitoring and some other aspects. However, because of the weak penetration of Cerenkov radiation, CLI can not image the deep tissues. This review summarizes the modalities to overcome this problem. (authors)

[en] Objective: To quantitatively compare the diagnostic capability of ⁶⁸Ga-NGR and ¹⁸F-FDG in well-differentiated hepatocellular carcinoma (HCC) bearing mice by microPET/CT imaging. Methods: The in vitro cellular uptake, in vivo microPET/CT imaging and biodistribution studies of ⁶⁸Ga-NGR and ¹⁸F-FDG were quantitatively compared in SMMC-7721-based well-differentiated HCC. The human fibrosarcoma (HT-1080) and human colorectal adenocarcinoma (HT-29) cells/xenografts were respectively used as positive and negative reference groups for CD13. The expression of CD13 was qualitatively verified by immunohistostaining. The levels of CD13 and glucose-6-phosphatase (G6Pase) were semi-quantitatively analyzed by Western blot test for all 3 types of tumors. Two-sample t test was used for data analysis. Results: The in vitro cellular uptake showed that the ⁶⁸Ga-NGR uptake in SMMC-7721 and HT-1080 cells was higher than that in HT-29 cells, and the ⁶⁸Ga-NGR uptake was higher than ¹⁸F-FDG uptake in SMMC-7721 cells. The in vivo microPET/CT imaging results revealed that the uptake of ⁶⁸Ga-NGR in SMMC-7721 tumor was (2.17 ± 0.21) %ID/g, remarkably higher compared to (0.73 ± 0.26) %ID/g of ¹⁸F-FDG uptake (Z = 8.826, P < 0.01). The tumor/liver ratio of ⁶⁸Ga-NGR was 2.05 ± 0.16, which was 2.03-fold higher than that of ¹⁸F-FDG. In the HT-1080 tumors, the uptakes of ⁶⁸Ga-NGR and ¹⁸F-FDG were both high, and the values were (2.46 ± 0.23) %ID/g, (3.47 ± 0.31) %ID/g. The uptake of ⁶⁸Ga-NGR was significantly lower than that of ¹⁸F-FDG in HT-29 tumors: (0.67 ± 0.20) %ID/g vs (3.17 ± 0.29)%ID/g; Z = 4.221, P < 0.01. Western blot and immunohis-tostaining results were as follows: HT-1080(CD13⁺, G6Pase^-), SMMC-7721(CD13⁺, G6Pase⁺), HT-29 (CD13^-, G6Pase^-). Conclusions: The uptake of ⁶⁸Ga-NGR is higher than ¹⁸F-FDG uptake in SMMC-7721 tumor bearing mice, therefore it is worthwhile to consider the feasibility of clinical translation for PET/CT in diagnosis of HCC. Furthermore, because of the difference in ⁶⁸Ga-NGR and ¹⁸F-FDG avidities in tumors with different molecular phenotypes of CD13 and G6Pase, there is an underlying potential for molecular imaging in the determination of molecular phenotypes. (authors)

[en] Objective: To explore the optimal conditions of preparing ⁶⁸Ga-DOTA-iNGR (NGR peptide containing CendR motif), to evaluate its biodistribution in normal mice and to perform microPET imaging in tumor-bearing nude mice. Methods: ⁶⁸Ga fresh eluent (200 μl, 92.5-129.5 MBq) obtaining with ⁶⁸Ge-⁶⁸Ga radionuclide generator was used to label DOTA-iNGR. The optimal conditions of labeling including pH, temperature, reacting time and concentration of DOTA-iNGR were determined. Then, the in vitro and in vivo stability and octanol/water partition coefficient of ⁶⁸Ga-DOTA-iNGR were further analyzed. The biodistribution in normal Kunming mice was examined at 10, 20, 40, 60 and 120 min after injection of ⁶⁸Ga-DOTA-iNGR. Nude mice bearing HT-1080 (CD13-positive) and HT-29 (CD13-negative) tumors were established and underwent microPET imaging at 1 h after the intravenous injection of ⁶⁸Ga-DOTA-iNGR. Data were analyzed using independent-sample t test. Results: The optimal conditions of labeling was mixing 2 μg DOTA-iNGR peptide with 200 μl ⁶⁸Ga (92.5-129.5 MBq) at pH 4.0, temperature 90-100 ℃ for 5-10 min. Under this condition, labeling rate reached (97.5 ± 1.3)%. The radiochemical purity of ⁶⁸Ga-DOTA-iNGR in both saline (room temperature) and mouse serum (37 ℃) were both above 95% after 4 h incubation, and the radiochemical purity in urine was greater than 85% after 1 h metabolism in vivo. The partition coefficient was -2.71 ± 0.18. In normal mice, majority of ⁶⁸Ga-DOTA-iNGR was excreted from kidneys with a rapid clearance from blood. The in vivo microPET imaging showed that ⁶⁸Ga-DOTA-iNGR was remarkably accumulated in the CD13-positive HT-1080 tumor. Conclusions: Labeling DOTA-iNGR with ⁶⁸Ga under our condition is a simple and efficient procedure with high labeling rate and high specificity. The product ⁶⁸Ga-DOTA-iNGR has high stability, ideal biodistribution, and specific binding to CD13-positive tumor, which means that it's a very promising molecular probe for noninvasively detecting CD13-positive tumor. (authors)

[en] Objective: Using Cerenkov radiation energy transfer (CRET) effect of rare earth nanoparticles (RENPs) to enhance and convert Cerenkov luminescence into Cerenkov luminescence excited fluorescence, and to compare the accuracy of Cerenkov luminescence tomography (CLT) and Cerenkov luminescence excited fluorescence tomography (CLFT). Methods: ⁶⁸Ga (0.74 MBq) was used to respectively excite Y_2O3 : Eu³⁺, Er₂O₃ and Eu2_O3 (10 mg/ml). Various radioactivities of ⁶⁸Ga (3.70, 1.85, 0.92, 0.46, 0.23 MBq) were used to respectively excite Y₂O₃ : Eu³⁺ with a fixed concentration (10 mg/ml). A fixed radioactivity of ⁶⁸Ga (3.70 MBq) was used to excite Y₂O₃ : Eu³⁺ with different concentrations (10.0, 5.0, 2.5, 1.2, 0.6 mg/ml) in order to find the relationships between the optical intensity and the radioactivity of ⁶⁸Ga or the concentration of Y₂O₃ : Eu³⁺. Polyethylene tubes containing ⁶⁸Ga (0.74 MBq) and ⁶⁸Ga (0.74 MBq)+Y₂O₃ : Eu³⁺ (1 mg) were respectively implanted into two nude mice, then PET/CT and optical imaging were acquired. Three-dimensional reconstruction was proceeded. One-way analysis of variance, two-sample t test, linear correlation analysis were used for data analysis. Results: Y₂O₃ : Eu³⁺ could significantly and stably enhance the Cerenkov optical signal (F = 53.35, q = 17.03, P < 0.001). The enhanced optical signal intensity had linear relationships with the radioactivity of ⁶⁸Ga or the concentration of Y₂O₃ : Eu³⁺ (r values: 0.99 and 0.93). Three-dimensional reconstruction result showed that CLFT had significantly higher similarity than CLT (0.43 ± 0.14 vs 0.16 ± 0.06, t = 5.090, P < 0.05). Conclusion: CLFT could reflect the distribution of radiopharmaceuticals more precisely than CLT, and therefore might have potential in biologic optical imaging. (authors)

[en] This paper presents a dam health monitoring model using long-term air temperature based on multivariate adaptive regression splines (MARS). MARS is an intelligent machine learning technique that has been successfully applied to deal with nonlinear function approximation and complex regression problems. The proposed long-term air temperature-based dam health monitoring model was verified on a real concrete gravity dam with efficient safety monitoring data. Results show that the proposed approach is promising for concrete dam behavior modeling considering the prediction error is much reduced.

[en] Highlights: ► To focus on the role of miRNAs in chondrogenesis and osteogenesis. ► Involved in the regulation of miRNAs in osteoarthritis. ► To speculate some therapeutic targets for bone diseases. -- Abstract: MicroRNAs (miRNAs) are a class of small molecules and non-coding single strand RNAs that regulate gene expression at the post-transcriptional level by binding to specific sequences within target genes. miRNAs have been recognized as important regulatory factors in organism development and disease expression. Some miRNAs regulate the proliferation and differentiation of osteoblasts, osteoclasts and chondrocytes, eventually influencing metabolism and bone formation. miRNAs are expected to provide potential gene therapy targets for the clinical treatment of metabolic bone diseases and bone injuries. Here, we review the recent research progress on the regulation of miRNAs in bone biology, with a particular focus on the miRNA-mediated control mechanisms of bone and cartilage formation.

[en] Glucose is a key energy substance in diverse biology and closely related to the life activities of the organism. To develop a simple and sensitive method for glucose detection is extremely urgent but still remains a key challenge. Herein, we report a colorimetric glucose sensor in a homogeneous system based on DNA-embedded core–shell Au@Ag nanoparticles. In this assay, a glucose substrate was first catalytically oxidized by glucose oxidase to produce H_2O_2 which would further oxidize and gradually etch the outer silver shell of Au@Ag nanoparticles. Afterwards, the solution color changed from yellow to red and the surface plasmon resonance (SPR) band of Au@Ag nanoparticles declined and red-shifted from 430 to 516 nm. Compared with previous silver-based glucose colorimetric detection strategies, the distinctive SPR band change is superior to the color variation, which is critical to the high sensitivity of this assay. Benefiting from the outstanding optical property, robust stability and well-dispersion of the core–shell Au@AgNPs hybrid, this colorimetric assay obtained a detection limit of glucose as low as 10 nM, which is at least a 10-fold improvement over other AgNPs-based procedures. Moreover, this optical biosensor was successfully employed to the determination of glucose in fetal bovine serum. (paper)

[en] To assess the performance of PET vascular activity score (PETVAS) in comparison with SUVmax, inflammatory biomarkers and ITAS-2010 score in a cohort of TAK patients. Sixty-four PET/CT scans acquired from 54 TAK patients were analyzed. The inflammatory activity was qualitatively determined by physician’s global assessment and quantitatively determined by ITAS-2010 score. SUVmax and PETVAS were acquired by consensus review. Levels of the inflammatory biomarkers C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and pentraxin-3 (PTX-3) were measured. Performance of the qualitative diagnoses and the quantitative correlation were, respectively, compared by receiver operating characteristic (ROC) curve and Spearman correlation coefficient. The biomarkers (CRP, ESR, PTX-3), PET uptake values (SUVmax, PETVAS), and ITAS-2010 scores were all significantly higher in active patients than in non-active ones. The area under the ROC curve and Youden Index of PETVAS and PTX-3 were higher than those of SUVmax, CRP, ESR, and ITAS-2010. PETVAS and PTX-3 resulted in a higher Spearman correlation coefficient with ITAS-2010 than other criteria, either among all patients or within the active group. Alteration trends of PETVAS and PTX-3 during follow-up showed a tighter correlation with clinical progression/remission assessment than other criteria. In TAK evaluation, PETVAS is superior for qualitative and quantitative assessment, compared with the regional SUVmax. Compared to CRP and ESR, inflammatory biomarker PTX-3 shows better qualitative performance and a higher correlation with PETVAS and ITAS-2010. These findings indicate that the use of PETVAS and PTX-3, instead of SUVmax and CRP/ESR, has potential advantages in the clinical evaluation of TAK.

[en] Integrin α_vβ_3 is the therapeutic target of the anti-angiogenic drug cilengitide. The objective of this study was to compare α_vβ_3 levels in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) patients, by using the positron emission tomography (PET) tracer "6"8Ga-labeled dimerized-RGD ("6"8Ga-RGD_2). Thirty-one patients with pathologically confirmed lung cancer were enrolled (21 were NSCLC and 10 were SCLC). PET/CT images were acquired using "6"8Ga-RGD_2."1"8F-FDG PET/CT images were also acquired on the consecutive day as reference. The standard uptake values (SUV) and the tumor/nontarget (T/NT) values were quantitatively compared. Expression of the angiogenesis marker α_vβ_3 in NSCLC and SCLC lesions was analyzed by immunohistochemistry. The "1"8F-FDG SUVmax and the SUVmean were not significantly different between NSCLC and SCLC patients. The "6"8Ga-RGD_2 uptake of SCLC patients was at background levels in both SUV and T/NT measurements and was significantly lower than that of NSCLC patients. The range value of "6"8Ga-RGD_2 SUVmean was 4.5 in the NSCLC group and 2.2 in the SCLC group, while the variation coefficient was 36.2% and 39.3% in NSCLC and SCLC primary lesions, respectively. Heterogeneity between primary lesions and putative distant metastases was also observed in some NSCLC cases. Immunostaining showed that α_vβ_3 integrin was expressed in the cells and neovasculature of NSCLC lesions, while SCLC samples had negative expression. The uptake of "6"8Ga-RGD_2 in SCLC patients is significantly lower than that in NSCLC patients, indicating a lower α_vβ_3 target level for cilengitide in SCLC. Apparent intra-tumor heterogeneities of α_vβ_3 also exist in both NSCLC and SCLC. Such inter- and intra-heterogeneity of α_vβ_3 may potentially improve current applications of α_vβ_3-targeted therapy and diagnostic imaging in lung cancer. (orig.)

[en] Herein, La-doped TiO₂ photocatalyst was synthesized by utilizing the recycled lanthanum from the waste fluorescent powder, and then was firstly immobilized on a commercial ceramic filter with porous structure and high surface area. Immobilized La-doped TiO₂ (La-TiO₂) was applied for photocatalytic degradation of acetone and NO at the ppb level under visible light region. It was found that 0.5 wt% La doping into TiO₂ exhibited an excellent photocatalytic performance. The photocatalytic removal efficiency of acetone and NO under visible light could reach up to 38% and 98% respectively, which were much higher than that of pure TiO₂ (28% and 65%, respectively). Moreover, the results of various physicochemical characterization showed that La-TiO₂ sol-gel could be uniformly immobilized on the ceramic filter by impregnation method and followed by a low-temperature calcination treatment process. The three-dimensional porous structure of ceramic air filter resulted in more adsorption sites and reaction contact between pollution gas and photocatalyst surface, which is superior to the powdered TiO₂ catalyst on substrates or thin film deposited on glasses. In order to the further application, the effect of relative humidity on photocatalytic performance was discussed. This work will provide a new perspective for promoting large-scale environmental application of immobilized photocatalysts.