Mesenchymal Stem Cell Transplantation for Liver Cell Failure: A New Direction and Option

Background and Aims. Mesenchymal stem cell transplantation (MSCT) became available with liver failure (LF), while the advantages of MSCs remain controversial. We aimed to assess clinical advantages of MSCT in patients with LF. Methods. Clinical researches reporting MSCT in LF patients were searched and included. Results. Nine articles (n=476) related with LF patients were enrolled. After MSCT, alanine aminotransferase (ALT) baseline decreased largely at half a month (P<0.05); total bilirubin (TBIL) baseline declined to a certain stable level of 78.57 μmol/L at 2 and 3 months (P<0.05). Notably, the decreased value (D value) of Model for End-Stage Liver Disease score (MELD) of acute-on-chronic liver failure (ACLF) group was higher than that of chronic liver failure (CLF) group (14.93 ± 1.24 versus 4.6 ± 5.66, P<0.05). Moreover, MELD baseline of ≥20 group was a higher D value of MELD than MELD baseline of <20 group with a significant statistical difference after MSCT (P=0.003). Conclusion. The early assessment of the efficacy of MSCT could be based on variations of ALT at half a month and TBIL at 2 and 3 months. And it had beneficial effects for patients with LF, especially in ACLF based on the D value of MELD

MRI scanner variability studies using a semi-automated analysis system

Due to the unique design of the Parallel Rod Test Object (PRoTO) and the associated semi-automated analysis program, it was necessary to test it extensively for precision and accuracy, and preliminarily for utility, before its distribution for wider use in MRI system quality control (QC). The test object and analysis program measured the desired quantities reproducibly and they accurately measured predicted changes from intentionally adjusted imaging system parameters, yielding sensitivity of the various test measures to deviation in the system operating parameters. From a single scan of the most recent revision of the test object, multiple quantitative quality control measures were obtained throughout the scanning volume on two MR imaging systems over periods of six and twelve months, respectively. From these and earlier trials, an initial indication was obtained of which performance measures are worth monitoring for QC. This experience suggests that signal-to-noise ratio (SNR) and distortion (including display scale) should be monitored but not necessarily the resolution. The latter was only found to alter at the same time or later than other parameters such as SNR had changed. Slice thickness was found to vary on some units and this measure was also used in normalizing the SNR by voxel volume. SNR, distortion, and resolution measurements using field-echo sequences were less stable than those using spin-echo sequences. Use of this QC program to test a wide variety of image quality measures allowed timely assessment of the long-term variability of the units tested. Long-term variability may become among the most important measures for comparison of system performance and maintenance. Results are still inconclusive on the importance of tracking measures from sequences that are potentially most sensitive to small system misadjustments.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31950/1/0000903.pd

Magnetic resonance T(1) imaging of the breast using fat suppressed single scan technique.

Previous in vitro studies suggest that T\sb1 is significantly elevated in malignant breast tissues compared to normal. As a result, quantitative T\sb1 imaging of the breast in vivo is considered potentially specific for breast cancer diagnosis. For various reasons, however, breast T\sb1 imaging studies to date have produced T\sb1 values with great dispersion including considerable overlap between normal and malignant groups. The T\sb1 measurements from these in vivo studies are, therefore, not specific for diagnostic purposes. In conjunction with other measures, T\sb1 may yet be a valuable indicator. But prior to further studies, the accuracy of in vivo techniques should be improved. In this dissertation, we focus on two major factors hypothesized to contribute to T\sb1 scatter determined from in vivo imaging. The first is the strong contamination from undesirable fat signals in conventional proton T\sb1 images of the breast. The second is the often non-optimal experimental design of the T\sb1 imaging technique employed in previous studies. We first simulate the effects of these two factors on T\sb1 measurements of target breast tissues. We then develop and evaluate a reliable T\sb1 imaging technique combining the features of fat suppression with single scan, multiple acquisition point T\sb1 imaging. We further explore the clinical utility of this technique with a number of in vivo experiments. A special purpose breast coil is constructed for T\sb1 imaging experiments. The B1 homogeneity of the volume enclosed by the coil is assessed. In vitro tests employing chemical samples with T\sb1 values determined using a conventional inversion recovery technique are conducted to evaluate the proposed fat suppressed T\sb1 imaging technique. Twenty normal volunteers are studied using the fat suppressed T\sb1 imaging technique to assess relaxation time dispersion in different breast regions. The T\sb2 values of these breast regions are also measured using conventional multiple echo, spin echo images. The work described here establishes a foundation for further research to estimate the distribution of relaxation times of various malignant breast tissues and thereafter to ultimately determine the diagnostic value of relaxation times in breast cancer detection.Ph.D.Applied SciencesBiomedical engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/129403/2/9501078.pd

Multiscale Study on the Effect of Nano-Organic Montmorillonite on the Performance of Rubber Asphalt

In order to improve the high-temperature performance, antiaging performance, and storage stability of rubber asphalt, nano-organic montmorillonite (NOMMT) was mixed with rubber asphalt. Macroscopic influences of NOMMT on rubber asphalt were measured through penetration, softening point, ductility, rotational viscosity tests, dynamic shear rheology test, and bending beam rheology test at low temperature and were conducted on rubber asphalt with different contents of NOMMT. Then, the microscopic mechanism of NOMMT on the microscopic performance of rubber asphalt was studied through using scanning electron microscopy (SEM), infrared spectroscopy (IR), and differential scanning calorimetry (DSC). The results showed that the rubber particles were smoother, uniform, and dispersed after NOMMT was introduced, and the compatibility between NOMMT and crumbed rubber powder was good. Some stable structures were formed in the composite modified asphalt. The disappearance of alcohol phenol and the increase in related groups such as alkane, benzene, and hydrocarbon indicated that chemical reaction occurred between NOMMT and rubber asphalt, resulting in the changes of the performance of the composite modified system, so that high-temperature stability, antiaging properties, and storage stability were improved but its low-temperature performance was decreased

The Value of Fecal Microbiota Transplantation in the Treatment of Ulcerative Colitis Patients: A Systematic Review and Meta-Analysis

Background and Aims. Fecal microbiota transplantation (FMT) has challenged the traditional management of ulcerative colitis (UC) in recent years, while it remained controversial. We aimed to provide a systematic protocol of FMT treatment on UC. Methods. Studies reporting on FMT treatment in UC patients were performed. A fixed-effect model was used to assess the efficacy of FMT. Results. Eighteen studies were enrolled (n=446). A pooled proportion of patients who received FMT had a significant efficacy compared to the placebo group (odds ratio (OR): 2.73, P=0.002) with a low risk of heterogeneity (P=0.59, I2=0%). The Mayo score decreased to 5 points in a state of mild–moderate activity after FMT treatment, and the optimal range of the Mayo score baseline was 6–9 for FMT administration. Then, the baseline of the Shannon diversity index (SDI) had a negative correlation with the clinical response rate (R=−0.992, P=0.08) or remission rate (R=−0.998, P=0.036), and the optimal diversity of bacteria was at 7 days to one month. Moreover, the colonoscopy delivery and unrelated fecal donor had slight superiorities of FMT treatment. Conclusion. FMT treatment had a higher efficacy and shorter time-point of early assessment of effectiveness on UC patients compared to traditional therapies. And the optimal FMT delivery and donor were colonoscopy delivery and unrelated donor in clinical practice

Comparative Analysis of Human Mesenchymal Stem Cells from Umbilical Cord, Dental Pulp, and Menstrual Blood as Sources for Cell Therapy

Although mesenchymal stem cells (MSCs) based therapy has been considered as a promising tool for tissue repair and regeneration, the optimal cell source remains unknown. Umbilical cord (UC), dental pulp (DP), and menstrual blood (MB) are easily accessible sources, which make them attractive candidates for MSCs. The goal of this study was to compare the biological characteristics, including morphology, proliferation, antiapoptosis, multilineage differentiation capacity, and immunophenotype of UC-, DP-, and MB-MSCs in order to provide a theoretical basis for clinical selection and application of these cells. As a result, all UC-, DP-, and MB-MSCs have self-renewal capacity and multipotentiality. However, the UC-MSCs seemed to have higher cell proliferation ability, while DP-MSCs may have significant advantages for osteogenic differentiation, lower cell apoptosis, and senescence. These differences may be associated with the different expression level of cytokines, including vascular endothelial growth factor, fibroblast growth factor, keratinocyte growth factor, and hepatocyte growth factor in each of the MSCs. Comprehensively, our results suggest DP-MSCs may be a desired source for clinical applications of cell therapy

Multi-Scale DenseNets-Based Aircraft Detection from Remote Sensing Images

Deep learning-based aircraft detection methods have been increasingly implemented in recent years. However, due to the multi-resolution imaging modes, aircrafts in different images show very wide diversity on size, view and other visual features, which brings great challenges to detection. Although standard deep convolution neural networks (DCNN) can extract rich semantic features, they destroy the bottom-level location information. The features of small targets may also be submerged by redundant top-level features, resulting in poor detection. To address these problems, we proposed a compact multi-scale dense convolutional neural network (MS-DenseNet) for aircraft detection in remote sensing images. Herein, DenseNet was utilized for feature extraction, which enhances the propagation and reuse of the bottom-level high-resolution features. Subsequently, we combined feature pyramid network (FPN) with DenseNet to form a MS-DenseNet for learning multi-scale features, especially features of small objects. Finally, by compressing some of the unnecessary convolution layers of each dense block, we designed three new compact architectures: MS-DenseNet-41, MS-DenseNet-65, and MS-DenseNet-77. Comparative experiments showed that the compact MS-DenseNet-65 obtained a noticeable improvement in detecting small aircrafts and achieved state-of-the-art performance with a recall of 94% and an F1-score of 92.7% and cost less computational time. Furthermore, the experimental results on robustness of UCAS-AOD and RSOD datasets also indicate the good transferability of our method

Effect of Warm-Mix Agent EC-120 on Performance of Asphalt Binder and Its Microscopic Mechanism

In order to figure out the influence of the warm-mix agent EC-120 on the performance of the asphalt binder and its micro mechanism in warm-mixing process, a matrix asphalt, A-70, and SBS-modified asphalt, SBS I-D, were modified with different contents of EC-120, respectively. Then, conventional macromechanic performance tests, dynamic shear rheological (DSR) test at high-temperature, and bending beam rheological (BBR) test at low-temperature were carried out on asphalt binder samples. Meanwhile, they were microscopically analyzed through Fourier transform infrared spectrometer (FTIR) and differential scanning calorimeter (DSC). The results indicated that EC-120 can reduce the viscosity of asphalt binder at high temperature. With the increase of EC-120 content, the high-temperature rutting resistance of two kinds of warm-mix asphalt (WMA) increased, but their crack resistance at low-temperature was reduced. FTIR indicated that this is due to the generation of oxides containing carbonyl functional groups after EC-120 was blended with asphalt binder. The DSC endothermic curves of WMA binders are obviously different from those of base binders, and a strong endothermic peak appears in the interval of 102°C–113°C, indicating that EC-120 will endothermically melt at the temperature of 102°C∼113°C, so it can play the role in reducing the viscosity of asphalt binder at the range of construction temperatures

Simulation of Bending Fracture Process of Asphalt Mixture Semicircular Specimen with Extended Finite Element Method

In order to numerically simulate the whole fracture process including the initiation and propagation of crack in asphalt concrete semicircular specimens under external force, the extended finite element method (XFEM) was adopted considering the shortcomings of the conventional finite element method (FEM). The fracture processes of the semicircular specimens under 5 kinds of loading modes, Me, were analyzed, and the simulation results were compared to the actual fracture paths in the actual specimens. The results indicated that the critical effective stress intensity factor will decrease first and then increase with the increase of Me, and the XFEM simulation results are similar to that of the actual specimens in crack initiation angle and propagation path in the 5 different loading modes. It is proved that the XFEM is very effective in simulating the fracture process and has obvious advantages compared with the FEM. According to the stress state at the crack tip, the initiation angle and its propagation paths were analyzed, and it was pointed out that the increase of the shear stress component caused the crack initial angle to increase with the increase of Me