This study aimed to quantitatively assess the effectiveness of the Wuhan lockdown measure on controlling the spread of coronavirus diesase 2019 (COVID-19). : Firstly，estimate the daily new infection rate in Wuhan before January 23，2020 when the city went into lockdown by consulting the data of Wuhan population mobility and the number of cases imported from Wuhan in 217 cities of Mainland China. Then estimate what the daily new infection rate would have been in Wuhan from January 24 to January 30th if the lockdown measure had been delayed for 7 days，assuming that the daily new infection in Wuhan after January 23 increased in a high，moderate and low trend respectively (using exponential, linear and logarithm growth models). Based on that，calculate the number of infection cases imported from Wuhan during this period. Finally，predict the possible impact of 7-day delayed lockdown in Wuhan on the epidemic situation in China using the susceptible-exposed-infectious-removed (SEIR) model. : The daily new infection rate in Wuhan was estimated to be 0.021%，0.026%，0.029%，0.033% and 0.070% respectively from January 19 to January 23. And there were at least 20 066 infection cases in Wuhan by January 23，2020. If Wuhan lockdown measure had been delayed for 7 days，the daily new infection rate on January 30 would have been 0.335% in the exponential growth model，0.129% in the linear growth model，and 0.070% in the logarithm growth model. Correspondingly，there would have been 32 075，24 819 and 20 334 infection cases travelling from Wuhan to other areas of Mainland China，and the number of cumulative confirmed cases as of March 19 in Mainland China would have been 3.3-3.9 times of the officially reported number. Conclusions: Timely taking city-level lockdown measure in Wuhan in the early stage of COVID-19 outbreak is essential in containing the spread of the disease in China.
COVID-19 ; China/epidemiology* ; Cities ; Communicable Disease Control ; Humans ; SARS-CoV-2

This thesis aimed at the Bacillus natto TK-1 screened out from Natto.The lipopeptide was purified using Thin-Layer Chromatography(TLC),and investigated its anti-tumor activity.After acid precipitation and methanol extraction,the lipopeptide was separated on TLC.Then the authors get the monomer surfactin which molecular weight is 1036Da through the High performance liquid chromatography(HPLC),electro spray ionization-mass spectrometry(ESI-MS) and infrared(IR).MTT method was implied to testify the anti-tumor activity of the purified sample from TLC.The results indicated a concentration and time-dependent relationships.After 48h,their IC50 were 40 mg/L.The detection with inverted microscope fluorescence microscope displays that the surfactin will cause a series of Morphological changes to the cells.In TUNEL experiment,the authors noticed that surfactin has the ability to induce apoptosis,besides this inhibition shows an obvious time-dependent relationship.

The study was to develop cis-dichlorodiammineplatinum(DDP)-loaded formulations using a novel type of self-assembled compound composed of block copolymers synthesized by poly(?-glutamic acid)(?-PGA).For the potential of targeting liver cancer cells,D-galactose was conjugated on the prepared ?-PGA.In vitro,DDP can be released from the resulting conjugate in PBS:there was a burst release during the first 8 h,then followed by sustained release.DDP could be easily incorporated into poly(?-glutamic acid)-D-galactose esterifiable derivative through a covalent bond.The yield of DDP incorporation into the esterifiable derivative was 9.4%～10.2%.In vitro experiments conclusively established that the poly(?-glutamic acid)-D-galactose esterifiable derivative-Cisplatin Complex Compound(?-D+-DDP)was much less toxic to normal cell lines than DDP only.The surviving rate of cells treated with ?-D+-DDP compound is higher than those treated with free DDP.Also it has obvious antitumor efficiency on human liver tumor BEL-7402 cells.HE staining indicated that the ?-D+-DDP compound make the BEL-7402 apoptosis.These results indicated that the conjugation of DDP to the esterifiable derivative reduced its cytotoxicity activity,but retains its antitumor activity in vitro.In conclusion,the ?-D+-DDP compound could be used as a potential clinic antitumor drug.The ?-PGA obtained by fermentation can be used as a valuable drug carrier system.

DDP could be easily incorporated into poly (?-glutamic acid)-D-galactose esterifiable derivative through a covalent bond. The yield of DDP incorporation into the ?-PGA was 9.4%～10.2%. The DDP was released in the initial 8h in a burst manner,and thereafter in a sustained manner. The results that the conjugation of DDP to poly (?-glutamic acid)-D-galactose esterifiable derivative not only reduced the toxicity of the DDP but also enhanced antitumor activity and the targeting ability. The vivo experiments conclusively established that the ?-D+-DDP compound was much less toxic to animals than DDP alone. A direct evaluation showed that mice treated with ?-D+-DDP compound at a dose of 7.5 mg/kg displayed significant tumor regression. Furthermore,the implanted solid tumors disappeared completely from 35% of the H22 tumor-bearing mice after ?-D+-DDP compound administration. The aforementioned results of biodistributions of the prepared ?-D+-DDP compound in various organs in normal mice demonstrated that the ?-D+-DDP compound had a specific interaction with liver's parenchymal cells and H22 hepatocellular carcinoma tumor cells via ligand receptor recognition. In conclusion,the results indicated that the ?-D+-DDP compound prepared can effectively target the site of hepatoma tumor via the recognition and significantly reduce its size. The ?-D+-DDP compound was less toxic than the free DDP,and could effectively reduce xenografted H22 hepatocellular carcinoma cells in KM mice and prolong the survival of KM mice grafted with H22 hepatocellular carcinoma tumor cells. Therefore,the prepared ?-D+-DDP compound may be used as a potential drug delivery system for the targeted delivery to liver cancers or other liver diseases.

Objective To assess response of rectal carcinoma to preoperative chemoradiation therapy(CRT)using DWI and tumor ADC values,and to investigate the value of ADC in predicting and monitoring therapeutic effect of CRT.Methods Twenty-six patients with primary rectal carcinoma undergoing preoperative CRT were recruited to the study.DWI was performed on a 1.5 T MR scanner in all patients at the time point of pre-therapy,the end of the 1st,2nd week of therapy and pre-operation,respectively.ADC values of the tumors were calculated on the workstation.Randomized block design was applied to analyze change in ADCs following treatment Results All patients were divided into T-downstaging group(n=12)and T-non-downstaging group(n=14).In T-downstaging group,the mean tumor ADC values were(1.10±0.13)×10~(-3),(1.32±0.19)×10~(-3),(1.35±0.13)×10~(-3),(1.32±1.00)×10~(-3) mm~2/s at the time point of pretreatment,week 1,week 2,pre-operation,respectively(F=16.420,P＜0.01).The mean tumor ADC value in T-non-downstaging had a slight increase from(1.16±0.16)×10~(-3) mm~2/s to(1.23±0.13)×10~(-3) mm~2/s at the time of week 1(P＞0.05).The ADC value in T-non-downstaging group continuously increased to(1.30±0.16)×10~(-3) mm~2/s at the end of the 2nd week of CRT(F=5.023,P＜0.01)and appeared statistical difference.The evolution of tumor ADC values in the two groups was significantly different.Early increases in tumor ADC were observed in T-downstaging group.Regarding the increase percentage of ADC value at 1st week as a diagnostic marker of tumor downstaging,when it was set as 11.6%,the sensitivity,specificity,positive predictive value and negative predictive value is 75.0%,78.6%,75.0% and 78.6% respectively,the area under curve(Az)was 0.774(95% confidence interval:0.583 to 0.964).Conclusions An early significant increase of mean tumor ADC value in rectal carcinoma has a potential to predict therapeutic effect of CRT.One week after beginning CRT is an early time point to monitor therapy efficacy.

Objective To clone and express the alkaline protease AprA , one important virulence factor secreted by Pseudomonas aeruginosa(PAE)in Escherichia coli, to clone and express the inhibitor of AprA (AprI) and its substrate flagellin , and to detect the function of AprA and the inhibitory function of AprI .Methods The genes encoding AprA ,AprI and flagellin gene were amplified respectively by PCR using PAE PAO 1 genome DNA as the template .The expression vec-tors (pET-28a-AprA, pET-28a-AprI and pET-28a-Flagellin) were constructed and transformed into E.coli BL21(DE3) respectively.The recombinant AprA protein was expressed by IPTG induction and purified via denaturing and renaturation. The recombinant AprI and flagellin were expressed and purified by Ni 2+affinity chromatography .The cleavage activities of AprA on flagellin were detected by SDS-PAGE.Results Recombinant AprA , AprI and flagellin protein were expressed and purified .It was demonstrated that AprA cleaved flagellin , which was blocked by AprI .Conclusion Recombinant AprA could cleave its substrates as an alkaline protease , and its inhibitor AprI inhibits the activities of AprA .This study will contribute to further investigations on the role of AprA in the pathogenesis of PAE .

Objective To establish a new processing method for gait data on Matlab to evaluate the hindlimbs behavior of non-human primates. Methods Gait analysis was tested on three rhesus monkeys 6 weeks after spinal cord injury, and kinematics data of hindlimbs were obtained using the VICON system. The raw data of kinematics were filtered and extracted, which were achieved through VICON 3D motion capture system with the Excel link combining Matlab with Microsoft Excel, and calculated in the Matlab environment. Results The kinematic parameters such as step length, step height, knee joint angle, and malleolus joint angle were gained by calculating. The mean values of step length (F=2.869, P=0.088) and step height (F=1.148, P=0.344) showed no significant difference at three speeds, which implied a higher repeatability of the data model. Angle-time curve reflected the joint function and movement. This system initially described the foot gait trajectory which could be used in gait repetitive analysis, and also generated the gait 2D/3D trajectories of hindlimbs. Conclusion The implement of these functions makes the post-processing of data more flexible and open whitout VICON system, and the calculated parameters and space tracing of gait trajectory basically meet the need of hindlimb behavior evaluation for nonhuman primate.

Adult ; Colitis, Ulcerative ; Colon ; Humans

OBJECTIVETo investigate the epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) expression in atrophic gastritis in rats to explore the relationship between EGF and chronic atrophic gastritis(CAG).

METHODSThe serum EGF and gastric mucosal, EGFR level were measured in 20 rats with CAG and 20 normal controls.

RESULTSThe average EGF level (0.149+/-0.020) microg/L and 80% positive rate of EGFR expression observed in CAG group were significantly higher than those in control group[(0.043+/-0.003) microg/L and 0%,P<0.01].

CONCLUSIONThe study demonstrates an association of high levels of EGF and positive EGFR expression in CAG rats. Further studies are necessary to clarify whether EGF/EGFR play a significant role in the pathogenesis of CAG.

Animals ; Epidermal Growth Factor ; blood ; physiology ; Gastric Mucosa ; chemistry ; Gastritis, Atrophic ; drug therapy ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Receptor, Epidermal Growth Factor ; analysis ; physiology

BACKGROUNDNumerous studies from Europe and North America have provided a wealth of information regarding the epidemiological and clinical characteristics of inflammatory bowel disease (IBD) in Caucasians. Previous studies in mainland China have been limited by small patient numbers or by lack of detailed information about clinical subgroups of the disease. This study was carried out to assess the demographic and clinical characteristics of IBD in Chinese patients.

METHODSIn the Sir Run Run Shaw Hospital between 1994 and 2003, 379 patients were diagnosed as IBD. Demographic and clinical data were collected and analysed.

RESULTSOf 379 patients, 317 had ulcerative colitis (UC) (83.6%, 168 male, 149 female, male-female ratio 1.13:1, age range at diagnosis 14-79 years, mean age 44 years) and 62 had Crohn's disease (CD) (16.4%, 39 male and 23 female, male-female ratio 1.70:1, age range at diagnosis 13-70 years, mean age 33 years). In UC, 11.4% of patients had proctitis, 25.2% had proctosigmoiditis, 18.6% were diseased to the splenic flexure and 44.8% had extensive colitis. Nine patients with UC (2.8%) had arthritis, three patients (0.9%) had iritis or conjunctivitis. Of the 62 CD patients, 16 (25.8%) had diseases restricted to the terminal ileum; 15 (24.2%) had colonic diseases; 20 (32.3%) had ileocolonic disease and 11 (17.7%) had disease involving the upper gastrointestinal tract.

CONCLUSIONSThis study shows similar characteristics of IBD to that in the West but there are some differences with respect to severity and extraintestinal manifestations. The ethnic and geographic differences may give important clues to the aetiology of IBD.

Adolescent ; Adult ; Aged ; China ; epidemiology ; Female ; Humans ; Incidence ; Inflammatory Bowel Diseases ; complications ; epidemiology ; genetics ; Male ; Middle Aged ; Retrospective Studies