PurposeTo develop a novel RGD microbubbles (RGD-MBs) and to evaluate the targeted binding effect with endothelial cells in vitro.Materials and MethodsThe RGD peptide was coated onto the microbubbles through biotin-avidin linkage including 10 μg/ml and 30 μg/ml groups. The microbubbles not carrying RGD peptide were obtained as negative control. Blocking studies were performed with pre-incubation of the cells with RGD peptide for 2 hours. The microbubbleswere characterized by Accusizer 780 and optical microscope. The binding specificity of RGD-MBs withανβ3-expressing mouse endothelial cells was determined with competitive inhibition experiments in vitro. The attachment study was performed using parallel plate flow chamber to investigate the dynamic adhesion on endothelial cells at various shear stresses.ResultsThe RGD-MBs had an average diameter of (4.09±0.07) μm. The binding RGD-MBs per cell were 2.98±0.35 for 10 μg/ml RGD and 1.78±0.23 for 30 μg/ml RGD. RGD-MBs binding to mouse endothelial cells decreased 54.64% and 67.00% in the presence of RGD peptide at a concentration of 10 μg/ml and 30 μg/ml respectively. When the shear stress was under 1.5 dyne/cm2, the accumulation rate was increased with the increase of shear stress (P<0.05). Accumulation rate reached the maximum (48.72±4.26) RGD-MBs/min at wall share stress of 1.5 dyne/cm2, and decreased as sheer stress >1.5 dyne/cm2 (P<0.05). Conclusion The RGD-MBs can specifically bind to endothelial cells, indicating its usefulness as ultrasonic molecular probe in monitoring integrinανβ3 expression during tumor angiogenesis, and is potentially valuable for in tumor early-staging and prognosis.

The ompA gene of Chlamyia psittaci in cows was amplified by PCR with primers designed based on those reported in GenBank.The amplified ompA gene was inserted into the bacterial plasmid vector pGEX-4T-1 and then transformed into E.coli BL21(DE3) with IPTG induction. The gene was derived from plasmid pMD18-T vector and then sequenced.It was demonstrated that this recombinant fusion protein of approximately 68kD in molecular mass was highly expressed in inclusion body and more pure proteins would be produced after purification.The fusion protein specifically reacted with positive sera of bovine Chlamydia as demonstrated by Western blotting. These results indicate that this recombinant fusion protein shows good reactivity and could be used to develop the diagnostic kit for bovine Chlamydia and genetic engineering vaccine.

Objective:To investigate the value of three-dimensional (3D) T 1WI structural images using different acceleration methods including parallel acquisition technique, joint compressed sensing (uCS) technique, and artificial intelligence-assisted compressed sensing (ACS) technique for brain region segmentation. Methods:In this cross-sectional study, fifty patients (female: n=25, age range: 13 to 87 years old) at Corning Hospital of Ningbo University from July to September 2023 were prospectively and consecutively collected. All the subjects underwent brain MRI. Six groups of 3D T 1WI structural images were obtained using different acceleration technique and parameters, including 3D T 1WI without acceleration factor (3D-T 1WI group), 3D T 1WI with parallel acquisition technique with acceleration factor 3 (3D-T 1WI-PI-3 group), 3D T 1WI with uCS technique with acceleration factor 4.5 and 6.9 (3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group), 3D T 1WI by ACS technique with acceleration factors of 3 and 5 (3D-T 1WI-ACS-3 group, 3D-T 1WI-ACS-5 group). T 2WI fluid-attenuated inversion recovery (FLAIR) images were also acquired. Subjective scores (cerebral grey matter and white matter clarity scores, clarity scores of cerebral white matter degeneration lesions in relation to the surrounding white matter, and Gibbs artifact scores) and objective metrics [signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), cerebrospinal fluid signal homogeneity, peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), and natural image quality evaluator (NIQE)] were used to evaluate image quality in different groups. Totally 109 brain regions were segmented and volumes were measured using the uAI Research Portal image analysis tool. Kappa or intraclass correlation coefficient ( ICC) was used to evaluate the agreement of subjective and objective evaluation indexes between the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, 3D-T 1WI-ACS-5 group, and 3D-T 1WI group. Kappa or ICC value>0.70 was considered as good agreement. Results:The acquisition time for the 3D-T 1WI group, 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, and 3D-T 1WI-ACS-5 group were 527, 204, 169, 95, 133, 90 s, respectively. Subjective evaluation showed that the 3D-T 1WI-uCS-4.5, 3D-T 1WI-ACS-3, and 3D-T 1WI-ACS-5 groups had excellent agreement with the 3D-T 1WI group in terms of the distribution of cases of cerebral grey matter and white matter clarity scores, respectively (all Kappa value=1.000); The distribution of cases of clarity score of cerebral white matter lesions and surrounding white matter in the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, and 3D-T 1WI-ACS-3 group were in good agreement with that of the 3D-T 1WI group ( Kappa values of 0.775, 0.701, and 0.777, respectively); the distribution of the number of cases of the Gibbs artifact score of the 3D-T 1WI-uCS-4.5, 3D-T 1WI-ACS-3, and 3D-T 1WI-ACS-5 groups was in good agreement with the 3D-T 1WI group (all Kappa value=1.000). Objective evaluation showed the CNR of the images in the 3D-T 1WI-PI-3, 3D-T 1WI-uCS-4.5, and 3D-T 1WI-uCS-6.9 groups were in good agreement with those of the 3D-T 1WI group ( ICC of 0.720, 0.759, and 0.752, respectively); PSNR and SSIM were in good agreement among the 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, 3D-T 1WI-uCS-6.9 group, 3D-T 1WI-ACS-3 group, and 3D-T 1WI-ACS-5 group (PSNR: ICC=0.854; SSIM: ICC=0.851). NIQE of 3D-T 1WI-PI-3 group, 3D-T 1WI-uCS-4.5 group, and 3D-T 1WI-ACS-3 group images were in good agreement with the 3D-T 1WI group ( ICC value of 0.866, 0.727, 0.753, respectively). The ICC values of the volume of each segmented brain region among the 3D-T 1WI-PI-3, 3D-T 1WI-uCS-4.5, 3D-T 1WI-uCS-6.9, 3D-T 1WI-ACS-3, 3D-T 1WI-ACS-5 group and the 3D-T 1WI group images showed decreased in order (all ICC≥0.62). Conclusions:The uCS and ACS techniques used in 3D-T 1WI show high agreement with 3D-T 1WI in terms of brain segmentation. The application of these accelerating techniques can significantly shorten the acquisition time with obtaining images with good image quality, displaying great value.