A study on the job preferences and heterogeneity of medical students from different birthplaces:A discrete choice experiment based on six hospitals in Beijing / 中国卫生政策研究

Objective:To analysis the job preference and heterogeneity of medical students by distinguishing their birthplaces,and to provide reference for optimizing the management of primary health care resources.Methods:Using a cluster sampling method,an online survey of discrete choice experiment was conducted with 925 medical students from six teaching hospitals in Beijing,741 valid questionnaires were obtained,the effective recovery rate was 80.1%.The mixed logit model was used to perform regression analysis on six job attributes and estimate the willingness to pay.Results:There were significant differences in the choice of work location among medical students from different birthplaces.The subgroup results showed that compared to medical students from city,undergraduates from rural and county district preferred a work with sufficient career development opportunities.The results of undergraduate subgroup showed that undergraduates from rural district preferred a work with good environment than those from other birthplaces.Conclusion:There is heterogeneity in job preferences of medical students from different birthplaces.Policy makers should pay attention to the medical students'birthplace,also take the educational level into account to optimize the diversified job attributes,formulating targeted intervention to attract primary health care talents.

Heat-sensitive moxibustion for migraine without aura: a randomized controlled trial / 中国针灸

OBJECTIVE@#To compare the clinical effect between heat-sensitive moxibustion and mild moxibustion for migraine without aura.@*METHODS@#A total of 54 patients with migraine without aura were randomized into an observation group (27 cases, 2 cases dropped off) and a control group (27 cases, 2 cases dropped off). The basic western medication treatment was adopted in the two groups. In the control group, mild moxibustion was applied at Shuaigu (GB 8), Fengchi (GB 20) and Yanglingquan (GB 34) on the affected side. In the observation group, the frequent acupoint areas of the affected side i.e. Shuaigu (GB 8), Fengchi (GB 20), Taiyang (EX-HN 5), Taichong (LR 3), Yanglingquan (GB 34) were determined, 3 acupoints with strong heat-sensitive sensation were selected each time and mild moxibustion was adopted. The treatment was given once a day, 5 times of treatment was as one course and 2 courses were required in the two groups. Before and after treatment, the scores of migraine symptom, visual analogue scale (VAS), migraine specific quality of life questionnaire (MSQ) were observed, and the clinical efficacy was evaluated after treatment in the two groups.@*RESULTS@#After treatment, the scores of migraine symptom and VAS were decreased compared with those before treatment (P<0.01), while the MSQ scores were increased compared with those before treatment (P<0.01) in the two groups. After treatment, the scores of migraine symptom and VAS in the observation group were lower than those in the control group (P<0.05), while the MSQ score in the observation group was higher than that in the control group (P<0.01). The total effective rate was 92.0% (23/25) in the observation group, which was superior to 72.0% (18/25) in the control group (P<0.05).@*CONCLUSION@#Both heat-sensitive moxibustion and mild moxibustion can effectively alleviate the clinical symptoms, improve the headache degree and life quality in patients with migraine without aura, the clinical efficacy of heat-sensitive moxibustion is superior to that of mild moxibustion.

Influence of antimicrobial peptide biofunctionalized TiO2 nanotubes on the biological behavior of human keratinocytes and its antibacterial effect / 中华口腔医学杂志

Objective: To fabricate TiO2 nanotube material functionalized by antimicrobial peptide LL-37, and to explore its effects on biological behaviors such as adhesion and migration of human keratinocytes (HaCaT) and its antibacterial properties. Methods: The TiO2 nanotube array (NT) was constructed on the surface of polished titanium (PT) by anodization, and the antimicrobial peptide LL-37 was loaded on the surface of TiO2 nanotube (LL-37/NT) by physical adsorption. Three samples were selected by simple random sampling in each group. Surface morphology, roughness, hydrophilicity and release characteristics of LL-37 of the samples were analyzed with a field emission scanning electron microscope, an atomic force microscope, a contact angle measuring device and a microplate absorbance reader. HaCaT cells were respectively cultured on the surface of three groups of titanium samples. Each group had 3 replicates. The morphology of cell was observed by field emission scanning electron microscope. The number of cell adhesion was observed by cellular immunofluorescence staining. Cell counting kit-8 (CCK-8) assay was used to detect cell proliferation. Wound scratch assay was used to observe the migration of HaCaT. The above experiments were used to evaluate the effect of each group on the biological behavior of HaCaT cells. To evaluate their antibacterial effects, Porphyromonas gingivalis (Pg) was respectively inoculated on the surface of three groups of titanium samples. Each group had 3 replicates. The morphology of bacteria was observed by field emission scanning electron microscope. Bacterial viability was determined by live/dead bacterial staining. Results: A uniform array of nanotubes could be seen on the surface of titanium samples in LL-37/NT group, and the top of the tube was covered with granular LL-37. Compared with PT group [the roughness was (2.30±0.18) nm, the contact angle was 71.8°±1.7°], the roughness [(20.40±3.10) and (19.10±4.11) nm] and hydrophilicity (the contact angles were 22.4°±3.1° and 25.3°±2.2°, respectively) of titanium samples increased in NT and LL-37/NT group (P<0.001). The results of in vitro release test showed that the release of antimicrobial peptide LL-37 was characterized by early sudden release (1-4 h) and long-term (1-7 d) slow release. With the immunofluorescence, more cell attachment was found on NT and LL-37/NT than that on PT at the first 0.5 and 2.0 h of culture (P<0.05). The results of CCK-8 showed that there was no significant difference in the proliferation of cells among groups at 1, 3 and 5 days after culture. Wound scratch assay showed that compared with PT and NT group, the cell moved fastest on the surface of titanium samples in LL-37/NT group at 24 h of culture [(96.4±4.9)%] (F=35.55, P<0.001). A monolayer cells could be formed and filled with the scratch in 24 h at LL-37/NT group. The results of bacterial test in vitro showed that compared with the PT group, the bacterial morphology in the NT and LL-37/NT groups was significantly wrinkled, and obvious bacterial rupture could be seen on the surface of titanium samples in LL-37/NT group. The results of bacteria staining showed that the green fluorescence intensity of titanium samples in LL-37/NT group was the lowest in all groups (F=66.54,P<0.001). Conclusions: LL-37/NT is beneficial to the adhesion and migration of HaCaT cells and has excellent antibacterial properties, this provides a new strategy for the optimal design of implant neck materials.

Neuregulin-1 preconditioning protects the heart against ischemia/reperfusion injury through a PI3K/Akt-dependent mechanism / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Neuregulin-1 (NRG-1), the ligand of the myocardial ErbB receptor, is a protein mediator with regulatory actions in the heart. This study investigated whether NRG-1 preconditioning has protective effects on myocardial ischemia/reperfusion (I/R) injury and its potential mechanism.</p><p><b>METHODS</b>We worked with an in vivo rat model with induced myocardial ischemia (45 minutes) followed by reperfusion (3 hours). NRG-1 message was detected in the heart using RT-PCR and the protein levels of NRG-1 and ErbB4 were detected by Western blotting analysis. Infarct size was assessed using the staining agent triphenyltetrazolium chloride and cardiac function was continuously monitored. The levels of creatine kinase and lactate dehydrogenase in plasma were analyzed to assess the degree of cardiac injury. The extent of cardiac apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and by Western blotting analysis of cleaved caspase-3. We examined the phosphorylation of Akt in the myocardium and the effect of PI3K/Akt inhibition on NRG-1-induced cardioprotection.</p><p><b>RESULTS</b>Transcription and expression of NRG-1 and phosphorylation of its ErbB4 receptor were significantly upregulated in the I/R hearts. NRG-1 pretreatment reduced the infarct size following cardiac I/R in a concentration-dependent manner with an optimal concentration of 4 µg/kg in vivo. NRG-1 pretreatment with 4 µg/kg, i.v. markedly reduced the plasma creatine kinase and lactate dehydrogenase levels. Pretreatment with NRG-1 also significantly reduced the percentage of TUNEL positive myocytes and the level of cleaved caspase-3 in the I/R hearts. Pretreatment with NRG-1 significantly increased phosphorylation of Akt following I/R. Furthermore, the cardioprotective effect limiting the infarct size that was induced by NRG-1 was abolished by co-administration of the PI3K inhibitor LY294002.</p><p><b>CONCLUSIONS</b>The concentration of NRG-1, a new autacoid, was rapidly upregulated after myocardial I/R. NRG-1 preconditioning has cardioprotective effects against I/R injury through a PI3K/Akt-dependent mechanism in vivo.</p>