Objective:To establish a novel in vivo and in vitro model of type 2 endoleaks (T2EL) after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA).Methods:In vitro model: Using 3Dmax (2022) software, models of AAA and T2EL were created. These models were fabricated using 3D printing technology, with quartz as the material. Fresh pig blood was injected into the models, and a circulation system was established using a peristaltic pump. The direction of blood flow was observed to confirm the establishment of the in vitro T2EL model. In vivo model: Six Bama miniature pigs were selected, each 10 months old and weighing 40-50 kg. After determining whether unilateral iliac artery occlusion could be permanent through experiments, an AAA animal model from the end of the abdominal aorta to the left common iliac artery was created using the patch formation method. EVAR was performed through the right femoral artery, completely occluding the left iliac artery. The T2EL model was established by using the retrograde blood flow from the left iliac artery. The formation of AAA and T2EL models in vivo was confirmed by color Doppler ultrasound, digital subtraction angiography (DSA), and other methods. The measurement data with normal distribution were expressed as mean±standard deviation( ± s), and comparisons between groups were performed using the independent-samples t-test. The comparison between groups of count data was conducted using the chi-square test. Results:The successful establishment of the T2EL model was confirmed by observing the blood flow in the circulating drip flask. The weight of the Bama miniature pigs in the in vivo model was (41.33±2.21) kg, the diameter of the abdominal aorta was (7.45±0.15) mm, and the maximum diameter of the aneurysm was (16.67±0.61) mm. Through experiments, it was determined that the left iliac artery and umbilical artery of the experimental pigs could be isolated. Therefore, after the aneurysm from the end of the abdominal aorta to the left common iliac artery was established, a covered stent was implanted from the abdominal aorta to the right common iliac artery for EVAR treatment. The successful establishment of the AAA model and the T2EL model with the left iliac artery as the main "culprit vessel" was confirmed by color Doppler ultrasound and DSA.Conclusion:The in vitro models established through 3D printing technology and the T2EL animal model with the left iliac artery as the main "culprit vessel" have a high success rate and can serve as a model basis for the mechanism and treatment research of T2EL after EVAR for AAA.

Enterotoxigenic Escherichia coli（ETEC）infection can induce watery diarrhea，leading to dehydration，electrolyte disturbance，and even death in severe cases. Recombinant B subunit/inactivated whole-cell cholera（rBS/WC）vaccine is effective in preventing ETEC infectious diarrhea. On the basis of the latest evidence on etiology and epidemiology of ETEC，as well as the effectiveness，safety，and health economics of rBS/WC vaccine，National Clinical Research Center for Child Health（The Children’s Hospital，Zhejiang University School of Medicine）and Zhejiang Provincial Center for Disease Control and Prevention invited experts to develop expert consensus on rBS/WC vaccine in prevention of ETEC infectious diarrhea. It aims to provide the clinicians and vaccination professionals with guidelines on using rBS/WC vaccine to reduce the incidence of ETEC infectious diarrhea.

The irreversibility of nerve cell injury is the main pathological basis of disability in stroke patients. In recent years, it has been found that neural stem cells (NSCs) with multi-directional differentiation potential and self-renewal capacity can proliferate under stress in the adult central nervous system, migrate to the injured area and differentiate into neural cells, thus participating in the repair of nerve injury. However, due to the limited number of homing stem cells, it is difficult to make up for the vacancy caused by the massive necrosis of neurons. This paper reviews the molecular mechanism of NSCs homing under ischemia and hypoxia, and explains the application prospect of NSCs in ischemic stroke.

Since an epidemic occur of Corona Virus Disease 2019(COVID-19) in December, 2019, all the dental healthcare service providers in our country have been greatly impacted. The strategy of managing the dental clinics is quite different from that of the medical healthcare clinics, and the key point of the administration of those dental healthcare providers is to focus on the management of outpatient care because they only supply just a little bit of inpatient care service but quite an large amount of outpatient care service. So we think the next step is to make plausible and effective scenarios to protect our dental healthcare staff and patients against corona virus infection during the treatments procedures after the reopening all of our dental clinics. To overcome this harsh condition, the infection prevention and control strategies adopted by the Stomatological Hospital, Southern Medical University were designed to be flexible and could be adjusted promptly according to the national and local governmental orders and latest guidelines released by the Centers for Disease Control and Prevention. All these prevention procedures and protocols were customized to fit our own situation and have been updated for several times based on the latest global pandemic reports. After going through the hardest time in the past four months, it’s considered that our COVID-19 prevention rules have been proved to be efficient and work well. Further more, it has made massive progress for the hospital in improving the capability of dealing with this state of emergency, especially by previewing and triaging patients strictly to cut off the possible coronavirus spreading from the original step, enhancing the standard precautions and those specific protocols made for minimizing the droplets, aerosol and contact transmission of COVID-19 indoors. Besides, a daily supervision system was set up as a routine job and a team of qualified infection prevention specialists were assigned to check and report every incorrect details during the whole procedure of dental practice. Meanwhile, the safety and well-being of the public and our medical workers could be also guaranteed through following those detailed prevention scenarios.