Objective To investigate the value of transoral carotid ultrasonography (TOCU) in detecting the change of distal extracranial internal carotid artery(ICA) with stenosis and occlusion in its initial segmen.Methods One hundred and ten patients with stenosis at least 50％ or occlusion in the initial segment of ICA diagnosed by high-frequency linear probe were enrolled as case group,while thirty two with healthy carotid arteries as control group.Both of the case and control groups were undergone high-frequency linear probe to examine CCA and the initial segment of ICA,and TOCU to observe their lumen transparency,color Doppler flow display and change of Doppler flow spectrum,even measuring the internal diameter,peak systolic velocity (PSV),end-diastolic velocity(EDV) and PSVICA/PSVCCA ratio,respectively.Digital subtraction angiography (DSA)were performed within two weeks,then compared with ultrasonography.Results 92.7％ patients were performed TOCU examination in case group and 93.8％ in control group.The internal diameter and PSV of the distal extracranial ICA became gradually smaller from control group to near occlusion group,and there were statistical significance between groups ( P ＜0.05),however,near occlusion group had no statistical significance compared with occlusion group( P ＞0.05).There were 80％ arteries having thrombus echo in occlusion group,and the others in this group having no thrombus had gloomy colour flow,even got low-velocity artery spectrum.Doppler flow spectrum of distal extracranial ICA showed characteristics of slow wave or single peak in near occlusion group,and spike shape or slow wave in 76.7 ％ arteries of 70％ ～near-occlusion stenosis group,but spike shape in 30.8％ arteries of 50％～69％ stenosis group,and the others were normal.Conclusions TOCU is useful for detecting the changing regularity of distal extracranial ICA with stenosis or occlusion in its initial segment and has the value of clinical application in association with high-frequency linear probe.

Objective To investigate the effects of ultrasound radiation force(USRF) on adhering of targeted microbubbles in vivo.Methods A rat model of cremaster muscle Inflammation was developed,and microbubble(MB) or targeted microbubble of intercellular adhesion molecule-1 (MBICAM) was injected through the caudal vein.Immediately after intravenous MB or MBICAM injection,the cremaster was insonated for 5 minutes and the control group was in sham ultrasound exposure.All mice were divided into four groups randomly:① MB + false USRF; ② MB + USRF; ③ MBICAM + false USRF; ④ MBICAM + USRF.Fluorescence microscope was performed in twenty mice to evaluate microbubbles adhesion and video recordings were made with a high-resolution camera.Results The adhesion number of MBICAM was significantly greater in USRF group than that of MBICAM in false USRF group [(43.4 ± 2.1)/view vs (14.8± 1.8)/view,P =0.000].The adhesion number of MB in USRF group was greater than in false USRF group [(6.2 ± 1.3)/view vs (4.6 ± 0.9)/view].But there is no statistical significance (P =0.129).The adhesion number of MBICAM in both USRF group and false USRF group was significantly greater than the adhesion number of MB.Conclusions The ultrasound radiation force can significantly improve the adhesion of targeted microbubbles in vivo.

ObjectiveTo assess the feasibility of evaluation of renal allograft acute rejection in rat withcontrast-enhancedultrasound( CEUS )andtargetedmicrobubbles.MethodsPhospholipid microbubbles targeted to intercellular adhesion molecule -1 (ICAM-1)(MBI) and control microbubbles (MB) were created by conjugating monoclonal antibody against ICAM-1 or isotype control antibody to the lipid capsule via “avidin-biotin” bridging.Ten SD rats with acute renal allograft rejection were injected intravenous of MBI and MB in random order with a 30-min interval.After 3 min of intravenous injection of microbubbles,targeted CEUS imaging was performed in all rats.And then the video intensity (VI) was determined.ResultsIn MBI group,a significant ultrasonic enhancement was observed,but it was not very obvious in MB group.Increment in VI value of transplant kidney in MBI group was great and it amounted to (27.0 ± 7.4)U,however,increment in VI value of in MB group was minor and it was merely (10.2 ± 2.4) U,Difference was evident in transplant kidney between of the two groups (P ＜ 0.05).Conclusions Molecular imaging of ICAM-1 with targeted CEUS can evaluate renal allograft acute rejection effectively.

Objective To identify the miR-122 which regulateing GATA4 expression during the induction of rat bone marrow mesenchymal stem cells (bMSCs) differentiating into cardiomyocyte-like cells. Methods BMSCs were isolat-ed from bone marrow and induced to differentiate into cardiomyocyte-like cells using 5-azacytidine. The miR-122 which may regulate expression of GATA4 were predicted using miRanda and TargetScan softwares and identified by dual luciferase report system. The expressions of miR-122 and GATA4 were determined using q-PCR during the differentiation of bMSCs into cardiomyocyte-like cells. Results The induced cells were completely in contacted with adjoining cells and uniform in shape and aligned parallelly. Cardiac troponin I (cTnI) expression was detected by immunofluorescence cytochemistry. Using dual luciferase reporter system in vitro, miR-122 were proved to be able to effectively inhibit GATA4 expression by binding the 3′UTR of GATA4 mRNA. q-PCR results showed that the expression of miR-122 is negatively correlated with that of GATA4 mRNA transcription. Conclusion These results indicated that miR-122 regulate the expression of GATA4 during the induction of cardiomyocyte-like cells.

Objective To evaluate the effect of continuous adenosine infusion on mesentery microcirculation during cardiopulmonary resuscitation in rats with asphyxia. Methods Rat model of asphyxia was established in 22 healthy Wistar rats. The animals were then randomly divided into normal saline group (group A, n=10), epinephrine group (group B, n=6) and epinephrine plus adenosine group (group C, n=6). After a 3-min asphyxia without intervention, cardiopulmonary resuscitation (CPR) was started. The cardiac compression was carried out with an electric cardio-pulmonary resuscitation machine (200 times/min). Respiration was restored and maintained with a ventilator with tidal volume of 4ml, breathing rate 50times/min and FiO2 100%. After a 4-min CPR, rats in group A and group B were given normal saline and epinephrine (bolus of 90?g/kg) respectively, and in group C epinephrine (bolus of 90?g/kg) plus 70?g/kg adenosine were given. Electric defibrillation would be initiated if there was ventricular fibrillation. The reperfusion rate of mesentery arterioles and venules, diameter of blood vessels and relative blood velocity were observed. Results The reperfusion rate of mesentery arterioles and venules was significantly higher in group C than in group B (P

Recently, drug delivery materials have become the hotspot of medical study. Suitable delivery material plays an important role in constructing an excellent drug delivery system. Silk fibroin is a naturally occurring protein polymer with excellent biocompatibility, remarkable mechanical properties, biodegradability and outstanding processability. Due to its unique properties, silk fibroin has become a favorable carrier material for the incorporation and delivery of a range of therapeutic agents. Based on the structure and characteristics of silk fibroin, this article provides an overview of the recent research progress of silk fibroin used as drug delivery materials.
Biocompatible Materials ; Drug Delivery Systems ; Fibroins ; chemistry

Objective To construct targeted ultrasound contrast agent carried goat anti-mouse IgG antibody (UCA-IgG) and evaluate the effectiveness of its targeted adhesion using parallel plate flow chamber. Methods The ultrasound contrast agent targeted to mouse IgG was designed by conjugating monoclonal antibodies against mouse lgG to the lipid monolayer shell of the agent using biotin-streptavidin. The binding of IgG antibodies to the ultrasound contrast agent were identified by fluorescence in vitro. The attachment and detachment of UCA-IgG to mouse IgG immobilized on a culture dish were assessed in a parallel-plate flow chamber. While the plate lacked mouse IgG,or blocked with large number of goat anti-mouse IgG were served as two control groups. Results UCA-IgG issued a bright green fluorescence, while the contral lipid ultrasound contrast agent didn't show fluorescence. The number of UCA-IgG bound to mouse IgG of experimental group was greater than two control groups,increased with increasing coverslips surface antibody concentrations (P<0. 05),and there was significant positive correlation between the number of UCA-IgG bound to mouse IgG and time of combination (P<0.05). The adhesion rate of experimental group increased with shear stress before 0. 5×10-5 N/cm2 (P<0.05) and then decreased (P<0. 05). There was limited adherence of control groups to the UCA-IgG. The stess of half-maximal detachment was increased with increasing coverslips surface antibody concentrations (P<0.05). Conclusions UCA-IgG could adhere to mouse IgG in the physical conditions. It may provide strong supports for studying other targeted ultrasound contrast agent preliminary and fatherly in vitro.

Objective: To explore the prevalence and associated factors of non learning-based screen time of 4-6 grade school students in Beijing, and to provide a basic data for further research on hazard control measures such as myopia, overweight and obesity among children and adolescents in Beijing. Methods: Multistage stratified random cluster sampling method was adopted. A total of 2 515 primary school students were randomly selected in from schools in Beijing, self-developed questionnaire was used to investigate on the time for each electronic products usage for non-learning purpose, the total of electronic products usage every day and other information. Results: The rates of screen time >15 minutes each time and ≥1 h daily were 48.43%, 22.90%, respectively. Multiple Logistic regression analysis showed that ordinary school, 6 th grade, male, single-parent family and other types of family, and lack of moderate-to-vigorous physical activity at weekend were associated with the students’ non learning-based screen time (OR=1.66, 2.28, 1.27, 1.44, 1.87, 2.20, P<0.05). Conclusion The situation of excessive screen time of primary school students was improved in Beijing, but still be prevelent, male students of grade 4 should be given more attention, and more importance should be attached to the offect of family in children.

Objective: To analyze the duration and influencing factors of moderate and vigorous physical activity(MVPA) on weekends for primary school students in grades 4 to 6 in Beijing, and to provide a reference for formulating health education and promotion measures. Methods: Multi stage stratified cluster sampling method was used to randomly select 2 515 students from grades 4-6 in 14 primary schools in Beijing, and a self administered questionnaire was used to record MVPA on weekend, social demographic characteristics, other related health behaviors and knowledge. Multivariate Logistic regression analysis was used to explore the influencing factors of MVPA on weekends. Results: The prevalence of insufficient MVPA on weekends in Beijing was 63.54 %, and the prevalence was higher among girls (69.92%) than boys (57.81%) ( χ 2=39.65, P <0.01). Multiple Logistic regression analysis revealed that girls ( OR =1.74), living in rural areas ( OR =1.41), participants attending general schools ( OR = 1.34 ), from divorced family ( OR =1.46), and short sleep duration ( OR =1.50) were more likely to fail to meet the MVPA recommendations( P <0.05). Conclusion It is quite common that no sufficient weekend MVPA among senior primary school students, among them, the outer suburbs and schools with relatively weak teaching resources are the key places that need attention, and girls are the key groups that need attention.

Objective: To investigate the epidemiology and related clinical features of hemorrhagic fever with renal syndrome (HFRS) in Qingdao, and provide relevant evidence for clinical diagnosis and treatment. Methods: The retrospective analysis method was used to collect the epidemiological and clinical data of 104 patients with HFRS diagnosed in the Affiliated Hospital of Qingdao University from January 2014 to December 2018, and the general condition, clinical symptoms, laboratory examination and exposure history of the patients were analyzed. Results: One hundred and four patients with HFRS were aged from 10 to 87 years old, including 78 males and 26 females; mainly living in rural areas, accounting for 90.38% (94/104); and 54 cases from the Department of Nephrology, accounting for 51.92%. October to January of the following year was the main onset time, accounting for 68.27% (71/104). The clinical manifestations were 98 cases of fever, accounting for 94.23%; 66 cases of nausea and vomiting, accounting for 63.46%; and 57 cases of dizziness and headache, accounting for 54.81%. Laboratory examination showed more thrombocytopenia, urinary protein and occult blood positive, D-dimer elevation, C-reactive protein and procalcitonin elevation. Only 8 cases had a history of direct, indirect or suspicious contact. Conclusions The clinical features of HFRS are atypical. The main symptoms are fever, nausea and vomiting, dizziness and headache. Men are higher than women. The place of residence is mainly in rural areas. The exposure history is mostly unclear. Diagnosis should be combined with laboratory findings and early treatment to improve clinical outcomes.