Internct has provided abundant resources for teaching,but it also brings two challenges,information overload and knowledge fragmentation.Under the environment of Internct,only by efficient course designs,can teachers deal with these two new challenges,and attract students' attentions and motivate their learning interests.Among teaching designs,the design of teaching ‘opening speech’ is quite important.During the course construction of Epidemiology in China Medical University,design strategies on opening speech were explored;the principles of opening speech design were determined.And the opening speeches were designed and cumulated for the teaching modules of Epidemiology.Furthermore,the skills of opening speech design were summarized.

Objective To evaluate the changes of function of right ventricular using echocardiography after transcatheter closure of atrial septal defect(ASD)and to study the feasibility and superiority of echocardiographic evaluation of right ventricular function. Methods In 70 patients with transcatheter closure of ASD,echocardio?graphic examinations were made different time intervals after the closure to calculate right cardiac morpnology and function. Results After closure ASD in different time intervals, the size of RAEDd1, RAEDd2, RVEDd1, RVEDd2, RVEDd3, Inferior Vena Cava and RIMP, RVEF, TAPSE and FAC were obviously decreased(P<0.01)between two groups. All events were obviously decreased compared precious function(P < 0.01)and the interaction of the time (P < 0.01). Conclusion The construction of right ventricular narrows gradually and the function recovers after transcatheter closure of ASD in a year and those who did not become worse.

Objective To investigate the effects of levodopa/benserazide-loaded poly-lactide-coglycolide (PLGA) microspheres on motor deficits and levodopa-induced dyskinesia in a rat model of Parkinson' s disease (PD) and to explore the mechanisms underlying this effects.Methods The content of levodopa/benserazide released from the microspheres was determined by high-performance liquid chromatography.The rat model of PD was induced by 6-OHDA injections.Then the valid PD rats were treated with levodopa ( 12 mg/kg,s.c.)/benserazide ( 15 mg/kg,s.c.) or microspheres.Forepaw adjusting steps were measured on 1,4,7,10 and 14 days after treatment.After 2 weeks of treatment,the abnormal involuntary movements (AIM) were measured.Phosphorylated dopamine,cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) at threonine 34 levels were determined by immunohistochemistry and Western blot respectively.In addition,the levels of △FosB were measured by Western blot.Results In vivo release test showed that 76.2％ of levodopa and 83.6％ benserazide were released from the microspheres on day 7.Forepaw adjusting steps showed that the scores of forepaw adjusting steps in microspheres-treated PD rats were ( 5.8 ± 1.6 ) and ( 5.2 ± 1.5 ) respectively on 10 and 14 days of treatment,which were increased compared to levodopa-treaded PD rats (2.4 ± 1.1 and 1.2 ± 0.5 ; t =4.12,5.43,all P ＜0.01 ).The AIM scores of microspheres-treated rats ( 16.0 ±2.1 ) were decreased significantly compared to levodopa-treated rats ( 26.0 ± 3.2 ) on day 14 ( t =6.59,P ＜ 0.01 ).Immunohistochemistry indicated that the phosphorylated levels of DARPP-32 in microspheres-treated rats ( (3.7 ± 1.3 ) × 104 )were decreased significantly compared to levodopa-treated rats ( (7.9 ± 2.2) × 104 ; t =2.95,P ＜ 0.05 ).In addition,Western blot showed that the levels of phosphorylated DARPP-32 and △FosB were 119.4％ ± 11.3％ and 149.3％ ± 12.3％ respectively,which were decreased significantly compared to levodopatreated rats ( 184.8％ ± 13.7％ and 300.4％ ± 14.2％ ; t =4.12,2.91,all P ＜ 0.05 ).Conclusions Microspheres can be used to improve the motor deficits and reduce the expression of dyskinesia in PD rats.This may be due to the continuous release of levodopa/beserazide from the microspheres,which leads to continuous stimulation of PD rats and reduces the levels of phosphorylated DARPP-32 and △FosB in the striata of these rats.

Objective To investigate the clinical characteristics and treatments of endometrioid carcinoma patients with preoperative diagnosis of endometrial hyperplasia.Methods From 2005 to 2010, 404 patients were diagnosed with endometrioid carcinoma after hysterectomy.Among these patients,44 of them were diagnosed atypical endometrial hyperplasia(AEH) preoperatively.Retrospectively analysis the characteristics of these patients with SPSS13.0.Results Among the 44 cases, all of them were grade G1 disease, and 39 of them received comprehensive staging surgery.14(32%)young cases preserved bilateral ovaries.9 cases(20%) were given adjuvant radiology.No recurrence was detected during the median follow up of 52 months.Compared to the premenstrual group, although no statistical difference was detected, more patients with risk factors of deep myometrium invasion(4/22 vs 1/22) and lymph-vascular space invasion(LVSI, 3/22 vs 0/22) in the postmenstrual group.Compared to the patients who diagnosed with endometrioid cancer(EC) preoperatively, there are more patients with grade G1(P=0.000), fewer patients received adjuvant chemotherapy(P=0.003) and fewer recurrence(P=0.019) in AEH group.Conclusions The endomtrioid cancer patients who diagnosed with atypical hyperplasia preoperatively have better prognosis.Hysterectomy with bilateral ovaries preserved is acceptable in young patients.Post menopause patients have more risk factors of deep myometrium invasion and LVSI.

Objective: To explore the effects of subchronic aluminum exposure on the level of N6-methyladenosine (m6A) methylation and the expression of N6-methyladenosine RNA binding protein 1 (YTHDF1) in the hippocampus of rats. Methods: Twenty-four healthy male SD rats were randomly divided into the control group (normal saline), the low dose group [10 μmol/kg Al(mal)3], the medium dose group [20 μmol/kg Al(mal)3] and the high dose group [40 μmol/kg Al(mal)3], with 6 rats in each group. The Al(mal)3 solution was administered via intraperitoneal injection on alternate days for 90 days. Escape latency, target quadrant dwell time and platform crossing times were tested to evaluate the learning and memory ability of the rats by the Morris water maze test after exposure. The brain tissue was weighted and the brain-to-body weight ratio was calculated after euthanasia. The level of m6A methylation and the expression of YTHDF1 were determined by enzyme-linked immunosorbent assay and western blot assay, respectively. Results: All rats survived during aluminum exposure period. The brain-to-body weight ratios of the control group and the low, medium and high dose groups were (0.46±0.06)%, (0.44±0.04)%, (0.49±0.06)% and (0.51±0.07)%, respectively, with no statistically significant differences (P>0.05). The escape latency of rats in the high dose group was longer than that in control and low group during the third to fifth day (both P>0.05). The escape latency of rats in all groups was shortened with the increase of training days (P<0.05). The target quadrant dwell time of rats in low, medium and high dose groups were lower than that in control group, and the platform crossing times of rats in high dose group were lower than that in control group (all P<0.05). The methylation level of m6A and expression level of YTHDF1 in hippocampus of rats in medium and high dose groups was higher than that in control group (both P<0.05). Conclusion The learning and memory impairment caused by subchronic aluminum exposure may be related to the increase of m6A methylation level and the decrease of YTHDF1 expression.

Objective:To illustrate a relatively complete knowledge system (e.g., research outputs, current hotspots, and future trends) in the sepsis field and to help scholars grasp the scientific research direction or clinical focus of treatment.Methods:The relevant literatures of sepsis during the time from 1985 to 2019 in Web of Science database were collected. Sepsis-related research contents were generated using softwares (CiteSpace 5.6.R2 and VOSviewer 1.6.13), which using data mining, information processing and knowledge map methods, to analyze the historical evolution and predict the development trend.Results:A total of 8 189 papers on sepsis were published. The volume of publications were increasing yearly from 1985 to 2019, and reached the top list of 1 276 in 2019. For research contents of sepsis, it has formed the basic characteristics of sepsis which focusing on epidemiological studies and animal experiments. Through cluster analysis, the researches mainly focused on six aspects: septic rat, necrotizingenterocolitis, sepsis-associated encephalopathy, acute kidney injury (AKI), gut-derived sepsis, and inflammatory mediator. And it presented the literature characteristics that related to the injury or dysfunction of intestines, brain, liver, kidney or other organs, but the heart and lung researches were more marginal. Additionally, based on the top key words with the strongest citation bursts, it reflected that the development trend of the continuous attention hotspots with "endotoxin" or "endotoxin shock", the significant attention hotspots with "inflammation", "immunity" and "multiple organ dysfunction syndrome" (MODS), and the novel burst attention hotspots with sepsis management including "diagnosis" and "chemotherapy".Conclusions:Through the hotspots and trends visualization of sepsis, the current researches are prefer to animal experiments, epidemiology, or other basic scientific aspects. Meanwhile, the researches are mostly focusing on inflammatory reaction, immune function or organ dysfunctions. Integrating the knowledge maps of hotspots and trends, based on researches of epidemiology, diagnosis, risk factors, pathogenesis, or treatment, we predict that the future scientific topics will concentrating on childhood sepsis, organ injury mechanism or intervention relating to MODS, and integrated management of sepsis by combining traditional Chinese medicine and Western medicine.

Background Quartz dust cannot be degraded in the lungs, and inhalation of a large amount of quartz dust in the occupational production process will lead to the occurrence of pulmonary fibrosis, and then develop into silicosis. In recent years, studies have found that exosomes may be involved in the pathogenesis of fibrotic diseases by carrying microribonucleic acid (miRNA), but the mechanism of their actions in silicosis still needs to be studied. Objective To investigate the role of exosome-derived miRNA-21-5p/mothers against decapentaplegic homolog 7 (Smad7) in quartz dust-induced pulmonary fibrosis in rats. Methods Twenty-four healthy male SD rats were randomly divided into four groups (six rats in each group): control 4-week group, control 16-week group, quartz 4-week group, and quartz 16-week group. At the beginning of the experiment, 1 mL of quartz suspension (50 mg·mL⁻¹) and 1 mL of normal saline were injected into the trachea of rats in the quartz group and the control group, respectively, by means of one-time non-exposure intratracheal dust staining. Alveolar lavage was performed at the 4th and 16th weeks after dust staining, the exosomes in lavage solution were extracted by polyethylene glycol (PEG) precipitation, morphological identification was conducted by transmission electron microscopy (TEM), particle size of exosomes was detected by nano-tracking analysis (NTA), and the marker proteins CD9 and CD63 of exosomes were detected by Western blotting (WB). The expression of miRNA-21-5p in exosomes was determined by reverse transcription polymerase chain reaction (RT-PCR). The degree of lung tissue injury and fibrosis was observed by hematoxylin-eosin staining (HE) and Masson staining. The collagen content of lung tissue was detected by hydroxyproline (HYP) method. The expression of Smad7 protein in lung tissue was detected by WB. Results The results of pathological staining showed that compared with the control group, lung inflammatory cell infiltration, alveolar wall thickening, and collagen increase were observed after 4 weeks of dusting, and collagen deposition and silicon nodules appeared after 16 weeks of dusting. Compared with the control group, the expression level of HYP in the lung tissue of the quartz group was increased after 4 weeks and 16 weeks of dust staining (P<0.05). Transmission electron microscopy showed that exosomes were saucer-shaped, and the average particle size of exosomes was 95.8 nm by NTA. Positive expression of exosome marker proteins CD9 and CD81 was found by WB. Compared with the control group, the expression of exosome-derived miRNA-21-5p in alveolar lavage fluid in the quartz group increased in the 4th week and the 16th week (P<0.05), and the expression of Smad7 protein in lung tissue decreased (P<0.05). Conclusion Exosome-derived miRNA-21-5p and Smad7 may be involved in the mechanism of quartz dust-induced pulmonary fibrosis in rats.

Objective To determine the prognostic significance of positive peritoneal cytology (PPC) among patients with endometrial cancer and to find out potential risk factors for PPC in endometrial cancer.Methods Data were extracted from Peking Union Medical College Hospital between Jan 1 2005 and Dec 31 2010.Only those patients who had undergone a staging procedure were included.A total of 486 patients were identified.Statistical analyses were performed using Fisher`s exact test, Kaplan-Meier log rank, and Cox proportional hazards models.ResultsRate of PPC was 4.8% in endometrial cancer.Non-endometrioid endometrial cancer(P=0.000), stage Ⅲ/Ⅳ(P=0.000), deep myometrial invasion(P=0.001), and cervical stromal involvement(P=0.018) appeared to be risk factors for PPC in endometrial cancer.Univariate analysis revealed statistically difference in 5-year PFS (70.9% vs 90.0%) and 5-year OS (72.2% vs 96.0%).Progression-free survival and overall survival showedstatistically difference(P=0.005,P=0.000)between PPC and NPC endometrial cancer.On multivariate analysis, PPC remained no statistically difference in progression-free survival or overall survival(RR=3.812,95% CI 0.897-16.200,P=0.070;RR=3.426,95% CI 0.800-14.673,P=0.097).Conclusions PPC is not an independent risk factor in patients with endometrial cancer.Aggressive histology, FIGO stage, deep myometrial invasion and cervical stromal involvement are presumed to be associated with PPC in endometrial cancer.

Objective To investigate the high-risk factors of retroperitoneal lymph nodes metastasis (LNM) and the effect of lymph nodes metastasis on prognosis in patients with endometrial carcinoma (EC).Methods Retrospec-tive research was carried out from January 2005 to December 2010 to identify 289 endometrial carcinoma patients treated with retroperitoneal lymphadenectomy at Peking Union Medical College Hospital.The high-risk factors of retroperitoneal LNM and prognostic factors of this disease were studied.Results 1) The median age at diagnosis was 55 years old.Patients of stage Ⅰ, Ⅱ, Ⅲ and Ⅳ were 224 (77.5%), 13 (4.5%), 45 (15.6%) and 7 (2.4%), respectively.Two hundred and eighty-nine patients received pelvic lymphadenectomy, of that 30 (10.4%) patients were found the pelvic LNM.Ninety-six patients received periaortic lymphadenectomy, of that 11 (11.5%) patients were found the periaortic LNM.Twenty-one (7.3%) patients developed recurrent disease and 11 (3.8 %) dead.The median follow-up was 37 months and the median disease-free survival (DFS) was 34 months.2) In univariate analysis, the incidence of LNM significantly increased in patients with CA125 ≥ 35 U/mL preoperatively, non-endometrioid adenocarcinoma, low grade, deep myometrium invasion, diameter of tumor ≥ 2 cm, cervical stroma involvement, positive peritoneal cytology and vagina or parametrial involvement (P<0.05).In multivariate analysis, CA125 ≥ 35 U/mL preoperatively, low grade, deep myometrium invasion were the independent high-risk factors of LNM (P<0.05).3)The Kaplan-Meier analysis showed a significant difference between positive peritoneal cytology, vagina or parametrial involvement, appendix involvement, LNM and DFS (P<0.05).We also found a significant difference in the impact of non-endometrioid adenocarcinoma, low grade, deep myometrium invasion, positive peritoneal cytology, appendix involvement and LNM on overall survival (OS) (P<0.05).Cox regression analysis revealed retroperitoneal LNM is the independent prognostic factor of 5-year DFS (patients without LNM 92.1% vs patients with LNM 65.3%, P=0.002, 95% CI 0.078-0.552).We also found the trend that the 5-year OS was higher in patients without LNM than them with LNM, even though there was no significant difference(patients without LNM 96.1% vs patients with LNM 70.0%, P=0.086, 95% CI 0.039-1.238).Conclusions 1) there is a predictive value of low grade and deep myometrium invasion for EC patients with LNM.2)Patients with LNM have poorer prognosis than them without LNM.Therefore, patients with LNM should receive adjuvant therapy to reduce the risk of recurrence.

Microvascular manual suture technique is invented by doctor Carrel in 1912, it had become a core technique in microsurgery. This vascular anastomosis technique is effective. However, it also has some disadvantages such as time-consuming and labor- consuming. And as a residual foreign body, suture can also cause inflammation. In recent years, vascular couplers have been widely applied in clinic, this method ensuring the quality of anastomosis with faster speed. The four principles on ideal vascular anastomosis, which put forward by Carrel, is the target of improvement on vascular anastomosis tools. In recent years, Ring-coupling using negative pressure, vascular stents, hook stapling anastomat, fibrin glue, P407 and other new technologies have been reported, this paper will focus on the advantages and disadvantages of these technologies.