Poly-l-lysine modified MOF nanoparticles with pH/ROS sensitive CIP release and CUR triggered photodynamic therapy against drug-resistant bacterial infection.

The challenge of drug resistance in bacteria caused by the over use of biotics is increasing during the therapy process, which has attracted great attentions of the clinicians and scientists around the world. Recently, photodynamic therapy (PDT) triggered by photosensitizer (PS) has become a promising treatment method because of its high efficacy, easy operation, and low side effect. Herein, the poly-l-lysine (PLL) modified metal-organic framework (MOF) nanoparticles, ZIF/PLL-CIP/CUR, were synthesized to allow both reactive oxygen species (ROS) responsive drug release and photodynamic effect for synergistic therapy against drug resistant bacterial infections. The PLL was modified on the shell of the zeolite imidazole framework (ZIF) by the ROS-responsive thioketal linker for controllable CIP release. CUR were encapsulated in ZIF as the photosensitizer for blue light mediated photodynamic effect to produce singlet oxygen (1O2) and superoxide anion radical (O2-) for efficient inhibition towards methicillin-resistant Staphylococcus aureus (MRSA). The charge conversion from negative charge (-4.6 mV) to positive charge (2.6 mV) was observed at pH 7.4 and pH 5.5, and 70.9 % CIP was found released at pH 5.5 in the presence of H2O2, which suggests the good biosafety at physiological pH and ROS-responsive drug release of the as-prepared nanoparticle in the bacterial microenvironment. The as-prepared nanoparticles could effectively kill MRSA and disrupt bacterial biofilm by combination of chemo- and photodynamic therapy. In mice model, the as-prepared nanoparticles exhibited excellent biosafety and synergistic effect with 98.81 % healing rate in treatment of MRSA infection, which is considered as a promising candidate in combating drug resistant bacterial infection.

Enlightenment Significance of Scientific Research Trainingon Medical Students' Academic Thinking: Taking Shanghai Jiaotong University as Example / 中国医学伦理学

The development of modern medicine requires that doctors trained in medical colleges have the abili -ty to find and solve the problems scientifically .However , many factors affect the enthusiasm of medical students to participant in the scientific research training .Shanghai Jiaotong University summer scientific research training is a project which is carried out for medical students in school , and train their research ability and thinking .It includes basic theory , theoretical study of cell and molecular biology technology , and observation and operation of experi-mental techniques .Establishing perfect organization framework or path , bringing into research groups as research team members according to their interests , maintaining long-term contact to maintain their research continuity and other measures are helpful for the training of research ability of medical students .

Enlightenment Significance of Scientific Research Trainingon Medical Students' Academic Thinking: Taking Shanghai Jiaotong University as Example / 中国医学伦理学

The development of modern medicine requires that doctors trained in medical colleges have the abili -ty to find and solve the problems scientifically .However , many factors affect the enthusiasm of medical students to participant in the scientific research training .Shanghai Jiaotong University summer scientific research training is a project which is carried out for medical students in school , and train their research ability and thinking .It includes basic theory , theoretical study of cell and molecular biology technology , and observation and operation of experi-mental techniques .Establishing perfect organization framework or path , bringing into research groups as research team members according to their interests , maintaining long-term contact to maintain their research continuity and other measures are helpful for the training of research ability of medical students .

1H magnetic resonance spectroscopy in the evaluation of high intensity focused ultrasound ablation for primary liver cancer / 中华肝脏病杂志

To investigate the clinical value of 1H magnetic resonance spectroscopy (1H MRS) in the evaluation of high intensity focused ultrasound (HIFU) ablation for primary liver cancer. Routine magnetic resonance sequences, contrast-enhanced magnetic resonance imaging and respiratory-triggered single voxel point resolved spectroscopy sequence (PRESS) were performed on 24 patients with primary liver cancer before and after HIFU ablation. A respiratory-triggered axial T2 weighted imaging (T2WI) was used as localizer for PRESS. Spectroscopy data was transmitted to a personal computer and was post-processed with a custom software (Saker, provided by Ning Jing, an engineer in GE Healthcare). It would be considered "technical success" if the baselines of spectra were stable and main metabolites were without overlapping and could be identified. Integral areas of choline (Cho) peak at 3.2 parts per million (ppm) and lipid (Lip) peak at 1.3 ppm were measured, and the choline to lipid (Cho/Lip) ratios were calculated. The differences of areas of Cho, Lip peak and Cho/Lip ratios before and after HIFU ablation were compared by using paired samples t test, and a P value of less than 0.05 was considered statistically significant. The technical success rate of 1H-MRS was 87.50% (42/48). Integral areas of Cho peak and Lip peak of 20 patients with satisfied spectra were measured, and the Cho/Lip ratios were calculated. The Integral area of Cho peak decreased from 34 597+/-6 802 before HIFU ablation to 6 372+/-2 466 after HIFU ablation (t = 18.02, P less than 0.01). The Integral area of Lip peak increased from 147 948+/-16 317 before HIFU ablation to 149 069+/-16 345 after HIFU ablation (t = -15.11, P less than 0.01). The Cho/Lip ratio decreased from 0.23+/-0.03 before HIFU ablation to 0.04+/-0.02 after HIFU ablation (t = 25.32, P less than 0.01). 1H-MRS could provide information of metabolites changes of primary liver cancer after HIFU ablation and could be used as a complementary sequence to other magnetic resonance sequences to evaluate all around primary liver cancer after HIFU ablation.

The application of 3D liver acquisition volume acceleration integrated with array spatial sensitivity encoding technique in liver dynamic-enhancement scanning / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the application of 3D liver acquisition volume acceleration (3D-LAVA) integrated with array spatial sensitivity encoding technique (ASSET) in liver dynamic-enhancement scanning.</p><p><b>METHODS</b>One hundred forty-seven patients underwent conventional plain and contrast enhancement liver MR imaging. 3D-LAVA and 2D fast spoiled gradient recalled echo were used for contrast enhancement liver MR scanning in 90 and 57 patients respectively. In the 3D-LAVA group, integrated ASSET was used in 72 out of the 90 patients. Of the 57 patients who underwent examinations using 2D fast spoiled gradient recalled echo, portal vein CE-MRA was performed on 20. The ability of 3D-LAVA to detect the lesions and the advantage to shorten the acquisition time after integrating with ASSET were analyzed. Original images of 60 patients in the 3D-LAVA group were processed using MIP to illustrate the anatomy of the portal vein. They were compared with those shown by CE-MRA to evaluate the illustration abilities of the two approaches.</p><p><b>RESULTS</b>3D-LAVA is more sensitive than 2D-FSPGR in detecting metastatic hepatic carcinomas. In the 3D-LAVA group integrated with ASSET, earlier and peak arterial phase images were acquired in 34 cases; and earlier, peak and late arterial phase images were acquired in 23 cases. The illustrations of the portal vein anatomy by 3D-LAVA were similar to those shown by portal vein CE-MRA.</p><p><b>CONCLUSION</b>3D-LAVA integrated with ASSET can obtain higher quality multi-phase dynamic enhancement images of the liver in a shorter time, and in the meantime also shows the vascular anatomy.</p>