BACKGROUND:Some studies have indicated that different genes in tooth germ tissue play a role at different time, contributing to tooth germ development.
OBJECTIVE:To observe the expressions of dentin matrix protein 1, enamel protein, col agen I and homeobox gene 1 at different stage of in vitro culture of tooth germ cells.
METHODS:RNA from tooth germ cells was extracted at days 1, 3, 6 of in vitro culture. After reverse transcription, real-time quantitative PCR detection was adopted to measure relative expression of dentin matrix protein 1, enamel protein, col agen I and homeobox gene 1 mRNA.
RESULTS AND CONCLUSION:Dentin matrix protein 1, enamel protein, and col agen I mRNA expressions increased with culture time, and reached the peak at day 3 (P<0.05), whereas homeobox gene 1 mRNA decreased with culture time (P<0.05).

With population aging and socio?economic development, the sedentary time and behavior of the elderly are increasing, resulting in an increase in health risks as well. This review aimed to investigate the effects of sedentary behavior on the health of the elderly, factors contributing to sedentary behavior in the elderly, and sedentary behavior interventions for the elderly, as well as provide reference for sedentary behavior investigation and intervention study, to eventually achieve health promotion for the sedentary elderly.

Objective To investigate the applicability of zebra fish thrombosis model in antithrombotic activity screening of Chinese materia medica.Methods The living zebra fish thrombosis model was induced by adrenaline hydrochloride. Zebra fish were randomly divided into blank control group, model group, positive medicine group and medication group. Each group was given the corresponding medicine or embryo culture water. O-anisidine staining solution was used to stain and calculate the staining intensity of erythrocytes in zebra fish heart, and quantitative analysis was carried out. The platelet aggregation of transgenic zebra fish was observed and under qualitative analysis. Results Compared with the model group, 100μg/mL salvianolic acid B, 300, 900μg/mL aqueous extract of Salvia miltiorrhiza, 45μg/mL 95% ethanol extract and 400, 1200μg/mL hypothalamus could significantly inhibited the formation of zebra fish thrombosis (P<0.01).ConclusionZebra fish thrombosis model has good applicability in antithrombotic activity screening of Chinese materia medica.

Objective To analyze the current situation and influence factors of ordinary medical college undergraduates' contact with scientific research at early stage in order to provide references for scientific research.Methods Totally 1940 students majoring in clinical medicine,imaging,traditional Chinese medicine and nursing (2008 -2010 grade) in China Three Gorges University were enrolled to do questionnaine and SPSS 17.0 was used to do statistical analysis.Results Totally 1653copies of questionnaires were collected from 1940 students,the recovery rate was 85.21％.Two hundred and nineteen students ( 13.25％ ) participated in scientific research,65.28％ students thought college propaganda to be ordinary,95.43％ students got benefits from scientific research.The main influence factors of scientific research were lack of time (23.73％),insufficient knowledge reserves (22.03％) and researchers' own problems (39.73％).Conclusions Medical school should expand the range of scientific research and strengthen propaganda.Medical students should arrange research time and constantly improve their comprehensive ability so as to achieve good results.

AIM: To investigate the effects of sodium hydrosulfide ( NaHS ) , a donor of hydrogen sulfide ( H2 S) , on the membrane permeability , intracellular Ca 2+concentration ( [ Ca2+] i ) and the release of IL-1βinduced by a-denosine triphosphate (ATP) in rat microglia, and to explore the effect of H2S on ATP-P2X purinergic signaling pathway and the molecular mechanism of its neuroprotective effect .METHODS: Rat microglia in logarithmic growth phase were used in the study.The [Ca2+]i was detected by Fura-2/AM staining.Fluorescent dye YO-PRO-1 was used to observe the membrane permeability.Interleukin-1β(IL-1β) was measured by rat IL-1βELISA kits.RESULTS:The YO-PRO-1 flu-orescence intensity was obviously elevated by ATP induction in a dose -dependent manner in the rat microglia , but this effect was counteracted by NaHS pretreatment (P<0.05).[Ca2+]i rapidly increased and then decreased slowly , forming a sta-ble platform for a long time when rat microglia were treated with ATP .Ca2+spike activity induced by ATP had no change , but the platform disappeared (P<0.05) after NaHS pretreatment.The ATP and LPS together facilitated the release of IL-1β, but the phenomenon was inhibited by NaHS (P<0.05).CONCLUSION:Hydrogen sulfide may decrease the mem-brane permeability , calcium inflow and IL-1βrelease in rat microglia activated by high dose of ATP .The cytoprotection of hydrogen sulfide may be mediated by purinergic signaling pathway .

Objective To extract principal components from valuable indicators on conventional ultrasoundand contrast-enhanced ultrasound (CEUS) in the differential diagnosis of thyroid benign and malignant lesions and to discuss the diagnostic value of each indicator.Methods One hundred and three patients with 125 thyroid lesions (65 malignant lesions and 60 benign lesions) underwent preoperative grayscale ultrasound (GSUS),color Doppler ultrasound (CDUS) and CEUS examinations.Eighteen indicators were chosen to evaluate every lesion and principal components were extracted by principal component and valuable indicators were ordered by importance.Results There were significant differences on GSUS and CEUS indicators between benign and malignant lesions.The first principal component was the representation of contrast enhanced ultrasound and was valuable in the differential diagnosis of thyroid benign and malignant lesions.The rank of valuable CEUS indicators were homogeneity of enhancement,filling defect,relative arrival time of periphery,peak interior echogenicity,relative arrival time of interior,peak peripheral echogenicity and ring enhancement.Conclusions GSUS and CEUS are valuable in the differential diagnosis of thyroid benign and malignant lesions.

Objective To preliminarily evaluate the feasibility of elastography point quantification (ElastPQ) technology in the determination of liver stiffness as well as its impact factors.Methods Amount to 235 patients with liver neoplasms underwent liver stiffness measurement in the right lobe of liver using an ultrasound scanner (iU Elite,Philips).ElastPQ values were obtained and compared with the liver fibrosis stage (S),the grade of necroinflammatory activity (G) and steatosis assessed histologically as well as gender and age.The factors related to ElastPQ values were explored by stepwise regression in multiple linear regression analysis and the regression equation was established.Results In the multiple linear regression model of ElastPQ values,liver fibrosis and necroinflammatory activity were associated with ElastPQ (P ＜ 0.05) while other factors including age,gender and hepatic steatosis had no effect on ElastPQ statistically (P ＞0.05).The equation of linear regression was ElastPQ =1.205S + 1.075G + 4.537.Conclusions ElastPQ technique is a reliably noninvasive tool in the liver stiffness measurement.Liver fibrosis and necroinflammatory activity are the main factors affecting liver stiffness measured by ElastPQ.

Objective To investigate the discriminant analysis model of gray-scale ultrasound (GSUS),contrast-enhanced ultrasound (CEUS) and the combination of them in the differential diagnosis of benign and malignant thyroid lesions and the diagnostic values.Methods Ultrasound images of 211 thyroid lesions confirmed by pathology were synthetically reviewed by scoring 5 GSUS indicators including shape (X1),orientation (X2),interior echogenicity (X3),halo sign (X4),and microcalcification (X5),as well as 6 CEUS indicators including relative arrival time of microbubhles in the periphery (X6) and interior (X7),peak periphery (X8) and interior (X9)echogenicity,peripheral ring-enhancement (X10),homogeneity of enhancement (X11).The diagnostic models with their values of GSUS,CEUS and the combination of them were explored by discriminant analysis.Results The discriminant analysis function of GSUS in the diagnosis of thyroid benign and malignant lesions was g1 (X) =0.715 X1+0.276X2 + 1.028X3 +1.197X4 +0.923X5-2.202 with the diagnostic value 86.3％,the discriminant analysis function of CEUS was g2(X) =-0.392X6 +0.541X7-0.117X8 +0.562X9 + 1.173X10 +2.200X11-1.956 with the diagnostic value 89.1％,and the discriminant analysis function of the combination of GSUS and CEUS was g3 (X) =0.418X1 + 0.173X2 + 0.626X3 + 0.558X4 + 0.183X5-0.476X6 + 0.474X7-0.071X8 + 0.399X9 + 0.985X10 +1.639X11-2.530 with the diagnostic value 91.0％.Conclusions GSUS and CEUS were valuable in the differential diagnosis of benign and malignant thyroid lesions,and the combination of GSUS and CEUS was most valuable.

Purpose: To investigate the effectiveness of a structured death education program for older adults with chronic illness and their family caregivers. Methods: This study adopted two-group, nonrandomized quasi-experimental design. Patient–caregiver dyads in the intervention group (N = 40 dyads) engaged in the death education program at the bedside once a week for 5 weeks, and were compared with participants (N = 40 dyads) in the control group who received usual health education. The program consisted of five sessions based on the Interaction Model of Client Health Behavior. Death attitude, death competence, well-being, family function, and satisfaction were measured at baseline (T0), immediately after the intervention (T1), and 1 month later (T2). Data collection was conducted from July 30, 2019, to December 30, 2019. Results: The intention-to-treat analysis The intention-to-treat analysis of between groups at 1-month follow-up revealed that the intervention group had greater decreases in the fear of death (p=.002, 95% CI -2.53, -0.47; p<.001, 95% CI -3.61, -1.65) and death avoidance (p<.001, 95% CI -3.46, -1.84; p<.001, 95% CI -3.89, -2.43), had greater increases in the neutral acceptance (p=.032, 95% CI 0.05, 1.38;p<.001, 95% CI 0.99, 2.56) and death competence (p<.001, 95% CI 4.10, 8.01; p<.001, 95% CI 7.80, 12.11) in patients and caregivers, respectively. There were significant intergroup differences over time for patient well-being of (p<.001, 95% CI 3.06, 9.74) and satisfaction of (p<.001, 95% CI 2.01, 4.59). Results were consistent with the results from the sensitivity analysis. Conclusion This study demonstrated the feasibility and benefits of death education in hospitals and provided an implementation plan for nursing professionals. Nurses should consider providing death education for older adults with chronic diseases and their families to promote the development of palliative care and the quality of end-of-life.

Purpose: To investigate the effectiveness of a structured death education program for older adults with chronic illness and their family caregivers. Methods: This study adopted two-group, nonrandomized quasi-experimental design. Patient–caregiver dyads in the intervention group (N = 40 dyads) engaged in the death education program at the bedside once a week for 5 weeks, and were compared with participants (N = 40 dyads) in the control group who received usual health education. The program consisted of five sessions based on the Interaction Model of Client Health Behavior. Death attitude, death competence, well-being, family function, and satisfaction were measured at baseline (T0), immediately after the intervention (T1), and 1 month later (T2). Data collection was conducted from July 30, 2019, to December 30, 2019. Results: The intention-to-treat analysis The intention-to-treat analysis of between groups at 1-month follow-up revealed that the intervention group had greater decreases in the fear of death (p=.002, 95% CI -2.53, -0.47; p<.001, 95% CI -3.61, -1.65) and death avoidance (p<.001, 95% CI -3.46, -1.84; p<.001, 95% CI -3.89, -2.43), had greater increases in the neutral acceptance (p=.032, 95% CI 0.05, 1.38;p<.001, 95% CI 0.99, 2.56) and death competence (p<.001, 95% CI 4.10, 8.01; p<.001, 95% CI 7.80, 12.11) in patients and caregivers, respectively. There were significant intergroup differences over time for patient well-being of (p<.001, 95% CI 3.06, 9.74) and satisfaction of (p<.001, 95% CI 2.01, 4.59). Results were consistent with the results from the sensitivity analysis. Conclusion This study demonstrated the feasibility and benefits of death education in hospitals and provided an implementation plan for nursing professionals. Nurses should consider providing death education for older adults with chronic diseases and their families to promote the development of palliative care and the quality of end-of-life.