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.

This study is to screen 23 blank O/W type microemulsion (ME) samples, that is 15 samples from our laboratory, and 8 samples from literature; compare the conductivity-water content curve (CWCC) method and visual method in determining the critical water content during O/W type MEs' formation, to analyze the deficiency and the feasibility of visual method and to exploxe scientific meanings of CWCC method in judging the critical water content of O/W type MEs during formation. The results show that there is a significant difference between the theoretical feasible CWCC method and visual method in determining the critical water content (P<0.001), and the results judged by conductivity is higher than that by eye-based water content. Therefore, this article firmly confirmed the shortcomings of visual method and suggested that the eye-base "critical water content" may falls into continuous ME stage during O/W MEs' formation. Further more, the CWCC method has theoretical feasibility and scientific meanings in determining the critical water content of O/W type MEs during formation.

Objective To study the factors affecting the synthesis of 18F-MyoZone,and to evaluate its potential as a myocardial perfusion imaging (MPI) agent in normal Chinese mini-swine.Methods 18F-MyoZone was prepared by substituting the leaving group toluenesulfonyloxy (OTs) from the precursor compound with 18F-fluoride (18F-F-).The conditions affecting the labeling yield were studied by varying the amount of K2CO3 and precursor compound,18F-fluorination reaction time and temperature.PET was performed at 5,30,60 and 120 min post-injection on normal Chinese mini-swine.Results The doses of K2CO3 and precursor,the reaction time and the reaction temperature could affect the labeling yield of 18F-MyoZone,especially K2CO3.The optimized synthetic condition was 1.0 mg K2CO3,2.0 mg mpp2-OTs,20 min reaction time at 90 ℃.The total radio-synthesis time in this condition was 60 min.The uncorrected radiochemical yield was (24.0±5.1) ％.The radiochemical purity was ＞98％.PET imaging showed that 18F-MyoZone had high initial uptake (SUV=8.17± 1.83 at 5 min post-injection) and good retention (SUV =5.78±0.99 at 120 min post-injection) in the heart.The clearance of 18F-MyoZone from liver was very fast.The heart/liver ratios were 3.32,5.31,6.09 and 5.76 at 5,30,60 and 120 min post-injection,respectively.From 5 to 120 min post-injection,the outline of heart was clear and intact.There was almost no interference from the adjacent organs.The quality of PET images was highly satisfactory.Conelusions 18 F-MyoZone has the potential to be a good myocardial perfusion agent.The amount of K2CO3 used could significantly affect the labeling yield of 18F-MyoZone.

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.

Objective:To establish the quality control method for compound Jieyu granules. Methods:Liquorice was identified by TLC. saikosaponin a, Saikosaponin d and rutin were determined by HPLC. Results:The spots on TLC plates were clear without any in-terference. The linearity was achieved within the range of 0. 508-16. 200 μg (r=0. 999 8) for saikosaponin a, 0. 503-16. 100 μg(r=0.999 7) for saikosaponin d, and 0.130-4.250 μg(r =0.999 9) for rutin. The average recovery was 99.7%(RSD =2.03%), 99. 8%(RSD=1. 44%) and 102. 6%(RSD=1. 40%), respectively. Conclusion:The method is simple, reliable and accurate, and can be applied as the quality control method for compound Jieyu granules.

According to different epochs and development needs, a series of practices on environmental health and sanitary engineering were carried out, which played significant roles in promoting national economic and social developments and protecting the public health. This paper reviewed the main achievements in the past 70 years infields of patriotic health campaign, water sanitation and toilet improvement in rural areas, surveillance and investigation, health standard system, sanitary engineering equipment, stove improvement etc., and then proposed several prospects in the future.

According to different epochs and development needs, a series of practices on environmental health and sanitary engineering were carried out, which played significant roles in promoting national economic and social developments and protecting the public health. This paper reviewed the main achievements in the past 70 years infields of patriotic health campaign, water sanitation and toilet improvement in rural areas, surveillance and investigation, health standard system, sanitary engineering equipment, stove improvement etc., and then proposed several prospects in the future.

Objective:Employ Lasso regression to develop a nomogram model for predicting the risk of liver cirrhosis in patients with chronic hepatitis B (CHB).Methods:A retrospective analysis was conducted on age, gender, laboratory test results, and liver ultrasound results of 1218 patients diagnosed with CHB at the First Affiliated Hospital of Harbin Medical University between 1 January 2023 and 30 November 2023. Based on the R caret package, patients were divided into a training set ( n=853) and an internal validation set ( n=365) at a ration of 7∶3, and an additional 185 patients with CHB treated at the First Affiliated Hospital of Harbin Medical University Qunli campus during the same period was included as an external validation set. Lasso regression and multiple logistic regression were employed for variable selection and nomogram model construction. The discriminative ability, calibration, and clinical utility of the prediction model were evaluated using Receiver Operating Characteristic (ROC) curves, calibration curves, Decision Curve Analysis (DCA), respectively. Results:Age, platelet, gamma-glutamine transpeptidase, prealbumin, portal vein diameter, and spleen thickness were selected as predictive variables for the occurrence of liver cirrhosis in CHB patients ( P<0.05), and a nomogram model was constructed based on the aforementioned variables. The AUC values for the ROC curves in the internal validation set and external validation set were 0.934 (95% CI 0.910-0.959) and 0.881 (95% CI 0.820-0.942), respectively. The fitting degree of calibration curve was observed in both sets (Internal validation set P=0.881; External validation set P=0.478). DCA curves demonstrated the high clinical utility of the model. Conclusion:Age, platelet, gammaglutamine transpeptidase, prealbumin, portal vein diameter, and spleen thickness were risk factors for the occurrence of liver cirrhosis in CHB patients. The constructed nomogram model exhibits good predictive value and clinical utility.

Objective: To investigate the effect of O-Z flap for the reconstruction of round-or elliptical-shaped defects following the scalp tumor removal. Methods: The resection of the scalp tumor resulted in a round or elliptical-shaped defect. Intraoperative frozen section identified pathological diagnosis, while also ensured margin being tumor-free. Based on the size and location of the defect, the mobility of the surrounding scalp and hair distribution, two local flaps were designed in opposite directions on each side of the defect. The two flaps were rotated to close the defect in an O-Z fashion. Results: From April 2016 to November 2017, 6 patients underwent defect reconstruction using the scalp O-Z flap. The etiologies included basal cell carcinoma (n=2), squamous cell carcinoma (n=2), and trichilemoma and epidermoid cyst (n=2). The defect size ranged from 3.0cm×3.5cm to 5.0cm×6.0cm. Necrosis on the distal of the flap had occurred in 1 patient. It was taken approximately 6% of the flap size, and healed after conservative management. Other flaps survived without any complications. After 3 to 12 months follow-up, the appearance of the sclap was satisfactory and tumor recurrence was not noticed. Conclusions The O-Z flap technique can be considered as an alternative for the medium-sized defect reconstruction of the scalp. The postoperative outcome of scalp was satisfactory, without disrupted hair orientation.

Objective:To investigate the in vitro inhibitory effect of methylene blue mediated photodynamic therapy (PDT) combined with berberine on Porphyromonas gingivalis (P.g). Methods:P.g was cultured until the middle to late log phase, and methylene blue was added to P.g suspension at different mass concentrations for 5 min, and a laser (wavelength 660 nm, power 140 mW/cm 2) was irradiated for 2 min to find the optimal concentration of methylene blue combined with the laser for in vitro inhibition of P.g. The effect of methylene blue mediated PDT on the in vitro inhibition of P.g and the effect of berberine on the growth curve of P.g were observed. The inhibitory effect of methylene blue mediated PDT and berberine on P.g was investigated by successive combined applications. The effect of methylene blue mediated PDT on P.g morphology was observed by scanning electron microscopy. The absorption peaks of each component were measured by ultraviolet spectrophotometer. Results:The best inhibition was achieved at a methylene blue mass concentration of 24.414 1 μg/ml under 660 nm laser excitation. The differences were statistically significant in both the methylene blue and PDT groups compared with the control group (all P<0.001). 0.05 mg/ml berberine had an inhibitory effect on the planktonic bacteria of P.g. After P.g was treated with methylene blue mediated PDT, the bacterial cell walls were crumpled into clusters. Compared with the control group, the number of colonies was reduced in the 0.05 mg/ml berberine group, and the difference was statistically significant ( P<0.01). The difference between the 0.05 mg/ml berberine + light group and the control group was not statistically significant ( P>0.05). When PDT was combined with berberine, there was a synergistic inhibitory effect on P.g. PDT followed by berberine shows a better inhibitory effect on bacteria, and the differences were statistically significant (all P<0.01). After the berberine treatment, the bacterial surface became smooth, and the length of the bacterial body increased compared with the control group. Conclusions:Methylene blue mediated PDT has an inhibitory effect on P.g. When combined with berberine, it has a synergistic inhibitory effect on P.g., and the inhibition effect is better when PDT is applied first and then berberine is applied in combination.