Ischemic stroke is the leading cause of disability and mortality worldwide. The blood‒brain barrier (BBB) is the first line of defense after ischemic stroke. Disruption of the BBB induced by brain microvascular endothelial cells (BMECs) dysfunction is a key event that triggers secondary damage to the central nervous system, where blood-borne fluids and immune cells penetrate the brain parenchyma, causing cerebral edema and inflammatory response and further aggravating brain damage. Here, we develop a novel artificial mesenchymal stem cell (MSC) extracellular vesicles by integrating MSC membrane proteins into liposomal bilayers, which encapsulated miR-132-3p with protective effects on BMECs. The artificial extracellular vesicles (MSCo/miR-132-3p) had low immunogenicity to reduce non-specific clearance by the mononuclear phagocytosis system (MPS) and could target ischemia-injured BMECs. After internalization into the damaged BMECs, MSCo/miR-132-3p escaped the lysosomes via the H_II phase transition of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and decreased cellular reactive oxygen species (ROS) and apoptosis levels by regulating the RASA1/RAS/PI3K/AKT signaling pathway. In the transient middle cerebral artery occlusion (tMCAO) models, MSCo/miR-132-3p targeted impaired brain regions (approximately 9 times the accumulation of plain liposomes at 12 h), reduced cerebral vascular disruption, protected BBB integrity, and decreased infarct volume (from 44.95% to 6.99%).

Objective: To understand the current situation and associated factors of myopia among primary school students, and to provide scientific basis for prevention and control of myopia among primary school students. Methods: In Gansu, Guangdong, Guangxi, Guizhou, Liaoning, Shandong, Shanxi and other provinces, 1 prefecture was selected, and a number of primary schools were selected from each region. All the students in the class were selected as the object of this survey. A total of 8 365 middle school students were examined for their eyesight, and the data of general population economic indicators and natural environment indicators were obtained through the statistical yearbook of various provinces and cities. The influencing factors of primary school students myopia were analyzed by chi-square test and multivariate Logistic regression. Results: Univariate analysis showed that different provinces and different sex, different nationalities, different grade, parents average salary, sunshine duration, air temperature, altitude, longitude, latitude, different economic zone(χ2=116.22, 18.08, 26.33, 1 059.04, 14.86, 10.28, 16.95, 10.01, 23.15, 29.43, 88.14, P<0.05). Multivariate analysis results showed that gender, grade, sunshine duration, longitude were risk factor for poor vision(OR=1.31, 1.71, 1.45, 1.54, P<0.05); Economic zone and parents salary were protective factors for poor eyesight of students (OR=0.65, 0.86, P<0.05). Conclusion Myopia of primary school students is affected by a variety of factors, economic and social factors and natural environmental factors have an impact on the screening.

Objective To examine the correlation between serum interleukin-6 (IL-6) levels and sustained attention in patients with major depressive disorder (MDD).Methods 30 patients with MDD and 30 healthy controls were enrolled in the case-control study.Serum IL-6 levels in all subjects were assessed by sandwich enzyme-linked immunosorbent assay (ELISA).Sustained attention in all subjects was measured respectively using rapid visual information processing(RVP) task in the Cambridge neuropsychological tests automated battery (CANTAB).Results Serum IL-6 levels in patients with MDD were significantly higher than those in healthy controls after controlling for gender,age,education,smoking,and BMI ((12.03±0.83) pg/ml,(2.77±0.24) pg/ml) (P＜0.01).RVP total misses and RVP mean latency in patients with MDD were higher than those in healthy controls after controlling for gender,age,education,smoking,and BMI(RVP total misses (10.20±4.44),(5.37±3.67),P=0.008,RVP latency (486.78± 135.47) ms,(370.58±72.42)ms,P=0.014).Serum IL-6 level were positively correlated with RVP mean latency in patients with MDD (r=0.46,P=0.011).But there were no correlation between serum IL-6 level and RVP total hits and RVP total misses in patients with MDD(P＞0.05),and there were also no relationship between serum IL-6 levels and RVP task in healthy controls(P＞0.05).Conclusions Serum IL-6 level may be implicated in the impairment of sustained attention in patients with MDD,and elevated IL-6 level may influence the susceptibility to MDD.

Objective: To optimize delivery of gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA) at the posterior upper point on tympanic medial wall and heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery (hT2W-3D-FLAIR) sequence, and to implement the technique of detecting endolymphatic hydrops using gadolinium-enhancement MRI. Methods: Thirteen patients with periphery vertigo, who visited Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Changhai Hospital during June and December of 2017, were enrolled in the study.0.10-0.20 ml of Gd-DTPA in various dilutions (10, 20, and 40-fold) were delivered at the posterior upper point on tympanic medial wall using a soft-tipped tympanic suction and drug-spraying needle through an artificially perforated tympanic membrane. Inner ear MRI was performed at 8, 24 h after Gd-DTPA administration using a 3T MR machine in combination with a 20-channel Tim 4G head/neck coil and the sequence of hT2W-3D-FLAIR to detect the gadolinium-enhancement signal within the inner ear and possible endolymphatic hydrops. The scanning time was either 8 min 35 s or 15 min 11 s. Results: Efficient inner ear uptake of Gd-DTPA was detected and induced high signal to noise ratio of MRI in patients receiving targeted delivery of 0.15-0.20 ml of 10-fold diluted contrast agent at the posterior upper point on tympanic medial wall. At 8 h after delivery, significant uptake was detected in the scala tympani and vestibuli of hook region and basal turn of the cochlea, and perilymhatic compartment of the vestibule. At 24 h after delivery, the distribution of Gd-DTPA became homogenous in each turn of the cochlea and perilymphatic compartment of the vestibule. However, obvious individual variance existed in the inner ear uptake when 0.10 ml of 40-fold diluted Gd-DTPA was delivered. Efficient inner ear uptake and high quality images that generated in patients receiving 0.10, 0.15, and 0.20 ml of 20-fold Gd-DTPA demonstrated endolymphatic hydrops with minor individual variance. There was insignificant difference in the enhancement signal of inner ear between 0.15 and 0.10 ml groups when Gd-DTPA was diluted at 20-fold except for the signal of semicircular canal of 0.15 ml group (190.00±53.95 vs 165.50±42.13, t=2.61, P<0.05). There was insignificant difference in the image quality between 8 min 35 s and 15 min 11 s canning time. Various degrees of endolymphatic hydrops were detected in 7 cochleae and 11 vestibule, and both simultaneous cochlear and vestibular endolymphatic hydrops were detected in 4 ears. Cochlear endolymphatic hydrops was detected in all the 3 patients with definite Meniere′s disease, and 2 of them had combined cochlear and vestibular endolymphatic hydrops. Endolymphatic hydrops was not detected in patients with possible Meniere′s disease nor with symptoms of superior semicircular canal dehiscence. Conclusion Targeted delivery of 0.10 ml with 20-fold diluted Gd-DTPA (total dosage of 5 μmol) at the posterior upper point on tympanic medial wall in combination with 8 min 35 s scanning time hT2W-3D-FLAIR sequence for inner ear MRI in a 3T MR machine is a clinically practical method to detect endolymphatic hydrops, and reduce the requirement for MRI hardware.

OBJECTIVEWe propose a new iterative reconstruction method based on split-Bregman method with tight frame regularization for effective and accurate reconstruction of the sparse-view cone beam CT image.

METHODSA tight frame was chosen as the regularization term for the objective function, so that the image reconstruction involves only the minimization of an objective function according to the compressed sensing theory. We utilized the split-Bregman method to tackle the task of minimization in three steps: (1) a fast calculation of the forward projection matrix; (2) introducing an intermediate variable to transform the non-differentiated L1 regularization term into the differentiated L2 regularization problem, and solving the target function using conjugate-gradient method; (3) updating the intermediate variable using shrinkage formula from Bregman method.

RESULTSDigital and physical phantom experimental results suggested that our new approach had great advantages in terms of image quality, reconstruction time, and applicability.

CONCLUSIONThe proposed method can accurately reconstruct CBCT image with limited data to lower the X-ray dose and accelerate the calculation speed in comparison with the POCS method.

Objective We propose a new iterative reconstruction method based on split-Bregman method with tight frame regularization for effective and accurate reconstruction of the sparse-view cone beam CT image. Methods A tight frame was chosen as the regularization term for the objective function, so that the image reconstruction involves only the minimization of an objective function according to the compressed sensing theory. We utilized the split-Bregman method to tackle the task of minimization in three steps:(1) a fast calculation of the forward projection matrix;(2) introducing an intermediate variable to transform the non-differentiated L1 regularization term into the differentiated L2 regularization problem, and solving the target function using conjugate-gradient method; (3) updating the intermediate variable using shrinkage formula from Bregman method. Results Digital and physical phantom experimental results suggested that our new approach had great advantages in terms of image quality, reconstruction time, and applicability. Conclusion The proposed method can accurately reconstruct CBCT image with limited data to lower the X-ray dose and accelerate the calculation speed in comparison with the POCS method.

Objective We propose a new iterative reconstruction method based on split-Bregman method with tight frame regularization for effective and accurate reconstruction of the sparse-view cone beam CT image. Methods A tight frame was chosen as the regularization term for the objective function, so that the image reconstruction involves only the minimization of an objective function according to the compressed sensing theory. We utilized the split-Bregman method to tackle the task of minimization in three steps:(1) a fast calculation of the forward projection matrix;(2) introducing an intermediate variable to transform the non-differentiated L1 regularization term into the differentiated L2 regularization problem, and solving the target function using conjugate-gradient method; (3) updating the intermediate variable using shrinkage formula from Bregman method. Results Digital and physical phantom experimental results suggested that our new approach had great advantages in terms of image quality, reconstruction time, and applicability. Conclusion The proposed method can accurately reconstruct CBCT image with limited data to lower the X-ray dose and accelerate the calculation speed in comparison with the POCS method.

An algebraic image reconstruction from few views using bilateral-filtering iterative method was proposed due to the problem of computed tomography insufficient data in the present study. In each iteration reconstruction, we first used algebraic reconstruction technique (ART) algorithm to reconstruct an image, ensuring the non-negativity of the reconstructed image at the same time, and then performed bilateral-filtering to the above-mentioned image. In order to improve reconstructed image quality and accelerate the convergence speed, we developed a modified bilateral-filtering method. Shepp-Logan simulation experiments and real CT projection data reconstructions showed the feasibility of the algorithm. The results showed that, compared with the traditional methods of filtered back projection (FBP), ART and GF-ART,the proposed method has a higher signal-to-noise ratio, and maintains more effectively the image edge information.
Algorithms ; Artifacts ; Humans ; Image Processing, Computer-Assisted ; methods ; Radiographic Image Interpretation, Computer-Assisted ; methods ; Tomography, X-Ray Computed ; methods

OBJECTIVETo propose a new method for effectively and rapidly removing the ring artifacts in CT images based on image post-processing.

METHODSThe CT image with ring artifacts in the Cartesian coordinate was first transformed into an image with line artifacts in the polar coordinate. The image in the polar coordinate was then filtered by designing a one-dimensional filter to calculate the mean and variance of each pixel after filtering, which were compared with the variance threshold value and the pixel threshold value to determine the position of the artifacts for corrections accordingly. Finally, the polar coordinate image was converted into Cartesian coordinate image.

RESULTSSimulated and actual CT data experimental results demonstrated the efficiency of this method for removing artifacts, retaining the image fidelity and reducing the processing time.

CONCLUSIONThe new method can accurately recognize the position of the artifacts and effectively remove them to facilitate the clinical diagnosis.

Objective To investigate the clinical characteristics of sever acute pancreatitis (SAP) with high triglyceride(TG). Methods 82 patients with onset of SAP within 72 hours were involved in this study. These patients were divided into high TG group (n=26) and normal TG group (n=56) according to serum TG lev-els tested (high TG group≥1.7 mmoL/L;normal TG group<1.7 mmol/L on admission). Results 31.71% (26/82) SAP patients were discovered with high TG APACHE-Ⅱ grade of high TG group was higher than that of normal TG group on admission[(14.62±7.58) vs (10.68±5.21),P<0.01]. Within the onset of 72 hours,the incidence of cardiac,pulmonary and kidney dysfunction in high TG group was higher than those of normal TG group (34.62%,34.62% and 19.23% vs 5.36%,3.57% and 1.79%,P<0.01),and the incidence of pancreatic pseudocysts was higher in high TG group than that of normal group(42.31% vs 7.14%,P<0.01). No emergency and early-stage surgical cases in high TG group but 13 cases(23.21%) in normal group. There were 2 cases of high TG group and 4 of normal group averting to operation. Conclusion SAP patients with high TG have high incidence of early-stage organ dysfunction and local complication,in this case nonsurgical intervention is the first choice.