OBJECTIVES: Myocardial ischemia reperfusion injury (IRI) occurs occasionally in the process of ischemic heart disease. Sevoflurane preconditioning has an effect on attenuating IRI. Preserving the structural and functional integrity of mitochondria is the key to reduce myocardial IRI. Silent information regulator 3 (SIRT3), a class of nicotinamide adenine dinucleotide (NAD⁺) dependent deacetylases, is an important signal-regulating molecule in mitochondria. This study aims to explore the role of mitochondrial NAD⁺-SIRT3 pathway in attenuating myocardial IRI in rats by sevoflurane preconditioning. METHODS: A total of 60 male Sprague Dawley (SD) rats were randomly divided into 5 groups (n=12): A sham group (Sham group), an ischemia reperfusion group (IR group), a sevoflurane preconditioning group (Sev group, inhaled 2.5% sevoflurane for 30 min), a sevoflurane preconditioning+SIRT3 inhibitor 3-TYP group (Sev+3-TYP group, inhaled 2.5% sevoflurane for 30 min and received 5 mg/kg 3-TYP), and a 3-TYP group (5 mg/kg 3-TYP). Except for the Sham group, the IR model in the other 4 groups was established by ligating the left anterior descending coronary artery. The size of myocardial infarction was determined by double staining. Serum cardiac troponin I (cTnI) level was measured. The contents of NAD⁺ and ATP, the activities of mitochondrial complexes I, II, and IV, the content of MDA, the activity of SOD, and the changes of mitochondrial permeability were measured. The protein expression levels of SIRT3, SOD2, catalase (CAT), and voltage dependent anion channel 1 (VDAC1) were detected by Western blotting. The ultrastructure of myocardium was observed under transmission electron microscope. MAP and HR were recorded immediately before ischemia (T0), 30 min after ischemia (T1), 30 min after reperfusion (T2), 60 min after reperfusion (T3), and 120 min after reperfusion (T4). RESULTS: After ischemia reperfusion, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased (both P<0.01), and an obvious myocardial injury occurred, including the increase of myocardial infarction size and serum cTnI level (both P<0.01). Correspondingly, the mitochondria also showed obvious damage on energy metabolism, antioxidant function, and structural integrity, which was manifested as: the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level and mitochondrial permeability were increased (all P<0.01). Compared with the IR group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were increased in the Sev group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were decreased in the Sev group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were increased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were decreased in the Sev group (all P<0.01). Compared with the Sev group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased in the Sev+3-TYP group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were increased in the Sev+3-TYP group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were increased in the Sev+3-TYP group (all P<0.01). CONCLUSIONS Sevoflurane preconditioning attenuates myocardial IRI through activating the mitochondrial NAD⁺-SIRT3 pathway to preserve the mitochondrial function.
Adenosine Triphosphate/metabolism* ; Animals ; Male ; Mitochondria/metabolism* ; Myocardial Infarction/metabolism* ; Myocardial Reperfusion Injury/metabolism* ; NAD/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sevoflurane/metabolism* ; Sirtuin 3/metabolism* ; Voltage-Dependent Anion Channel 1/metabolism*

In view of the lack of teaching methods in the cultivation of medical professionalism, this paper puts forward some important strategies for improving medical students' professionalism through discussion-based film and television appreciation. High-quality discussion-based film and television appreciation can be designed according to the four links of film selection, concentrated viewing, independent discussion and summary feedback. At the same time, in practice, attention should be paid to three key issues: selecting appropriate films, ensuring the quality and depth of discussion, and paying attention to feedback and evaluation. Practice has proved that discussion-based film and television appreciation makes the cultivation of professionalism more attractive, and can promote the professional knowledge and professional spirit, enhance students' professional enthusiasm, promote the understanding of the connotation of professionalism and reflection on related issues. Medical colleges should continue to improve the design of film viewing in practice, so as to help students better absorb humanistic nutrients from the discussion and enhance the teaching effect of professionalism.

【Objective】 To compare the platelet apheresis donation rate via telephone and WeChat appointment in Shijiazhuang area during the COVID-19 epidemic, so as to give suggestions for optimizing blood donation appointment in major public events. 【Methods】 The number and appointment type of apheresis donors from January to March 2019(the control) vs January to March 2020(study group 1) vs January to March 2021(study group2) in Shijiazhuang area were collected. A total of 1 204 and 1 305 questionnaires were distributed to two study groups to analyze their acceptance of telephone and WeChat appointment. 【Results】 More turnout donors preferred WeChat appointment, relative to telephone calls, during January to March 2020 and 2021. But some inactive donors preferred appointment given by telephone calls. 【Conclusion】 Different appointment methods should be adopted to recruit blood donors according to the targets of blood centers, in the event of national or local COVID-19 epidemic.

This study aims to analyze the current construction of massive open online course (MOOC) of medical humanities in China, promote the sharing of high-quality curriculum resources, and provide information reference for curriculum design and planning. Mathematical statistics and mind map analysis were used to analyze 42 medical humanities MOOCs on 17 online course platforms during the epidemic, and the results showed that: ①the scale and quantity of medical humanities MOOCs need to be expanded; ②there is regional imbalance in MOOCs construction, with the largest number in East China; ③most of the courses are taught by teachers in a team, teachers with senior professional titles are the main force of the team, and some teams have multidisciplinary backgrounds; ④there are rich teaching contents related to humanistic knowledge and ability, but the content related to medical humanistic spirit cognition needs to be added appropriately. According to the above analysis, it's suggested that the construction of MOOC should focus on systematism and standardization, equip a team of teachers with multidisciplinary backgrounds, value curriculum design and planning, and pay full attention to the feedback and evaluation of learners to find out deficiencies.

SWOT theory can be used to analyze the internal and external competitive environment and conditions of online teaching in teaching hospitals during the epidemic prevention and control. Conducting online education of clinical medicine courses in a hospital affiliated toa hospital affiliated to a comprehensive university has advantages in resources, administrations and platforms. However, disadvantages of online medical education lie in the professionalism, specificity of doctors as teacher and request of special teaching tools, all of which may not be available online. Online education meets the need of constructing top level courses national wide, carrying out the dominant role of ideological work in medical education field, and promoting the autonomous learning. Meanwhile, online education also challenges the future reform of teaching mode, management, and space. Based on this, it's proposed to promote the informatization construction of hospital medical education, improve IT literacy of all teachers, build an educational informatization platform matching the hospital management, construct a multiple evaluation system based on intelligent teaching space, build an online and offline mixed curriculum system based on multi-disciplinary, and take it as a breakthrough to promote the construction of "new medicine".

Objective:To investigate the scientific research willingness of nursing undergraduates with senior grades in Beijing and to understand the attitudes of them with scientific research and difficulty in scientific research.Methods:From April to May 2019, this study selected totals of 319 nursing undergraduates with Grade three or four from four medical schools in Beijing as subjects by convenience sampling. The self-designed questionnaire was used to investigate the scientific research willingness, attitude and difficulty among nursing undergraduates.Results:Among 319 nursing undergraduates, 275 (86.21%) nursing undergraduates would like to participate in research projects during the undergraduate level; 270 (84.64%) nursing undergraduates thought it was necessary to carry out nursing research during the undergraduate level. In carrying out or taking part in scientific research, the objective difficulties included lack of guide and help, time and energy as well as academic atmosphere; the subjective difficulties involved the lack of scientific knowledge, difficulties in selecting projects and statistical analysis.Conclusions:Nursing undergraduates have positive attitudes with scientific research, but them meet with many difficulties when carrying out or taking part in scientific research. Research training for nursing undergraduates may help to improve scientific literacy of them and increase their scientific interest.

Objective: To describe the MICM (morphology, immunology, cytogenetics and molecular biology) characteristics of a case of acute myelomonocytic leukemia M 4C . Methods: The medical history data of the case of M 4C admitted to our hospital was reviewed. The results of bone marrow cell morphology, cytochemical stains, bone marrow biopsy, immunophenotype, cytogenetics, molecular test and NGS (next-generation sequencing) of the case were analyzed. Results: The bone marrow smear showed markedly active proliferation of bone marrow cells in which the myelomonocytic cells accounted for 85.6%. Cytochemical stains showed peroxidase (POX) stain partially and weakly positive; specific esterase AS-DCE partially positive; non-specific esterase α-NBE partially positive and smothered by sodium fluoride; non-specific esterase AS-DAE partially positive and smothered by sodium fluoride. Bone marrow biopsy showed hyperproliferative cells and diffused hyperplasia of blasts. Immunophenotype analysis showed that the abnormal cell population was positive for CD11B, CD64, CD56, cMPO, CD33, CD41, CD61, CD38 and CD58, but negative for CD13, CD34, CD117, CD7, CD123, HLA-DR, CD10, CD19, CD20, CD2, CD14, CD235, CD15, CD303, CD304, CD25, cCD79a, cCD3, cCD22, CD1a and TDT. Cytogenetic analysis showed 47, XY, t(9;11) (p22;q23),+mar. The molecular test for leukemia showed MLLT3/KMT2A gene rearrangement. NGS showed NRAS and TET2 mutation. The case was finally diagnosed as AML (acute myelomonocytic leukemia) M 4C with t(9;11)(p22;q23), MLLT3-KMT2A. Conclusion Leukemia M 4C may show the characteristics of both granulocytes and monocytes with complex morphological features. The combined examination of MICM should be necessary for the diagnosis of M 4C with great significance.

As a sensor of the olfactory system, olfactory epithelium plays an important role in the olfactory system. In addition, olfactory epithelium is the only neuroepithelial epithelium in mammals that can maintain its self-renewal all along. There are of great significance in researching regenerating and repairing neural tissues, transplanting and treatment neural stem cells as well as the occurrence of olfactory disorders and intervention. This review will describe the characteristics of olfactory epithelial stem cells, and mainly summerize the function and significance of each transcription factor in the process of olfactory epithelial stem cell development and differentiation, in order to provide new ideas for the study of olfactory epithelial stem cells.

Background and purpose:Metabolism change is one of the main characteristics of the tumor de-velopment. Many studies have conifrmed that cytosolic acetyl-CoA synthetase 2 (ACSS2) plays a critical role in hydro-carbon metabolism of cancer cells. This study aimed to explore the effect of ACSS2 on cellular proliferation, apoptosis and migration of A549 cells by RNA interference.Methods:The ACSS2 interference fragment ACSS2-siRNA and neg-ative control were designed and synthesized for RNA interference followed by the transient transfection in non-small cell lung cancer (NSCLC) cell line A549. Real-time lfuorescence quantitative polymerase chain reaction (RTFQ-PCR) was used to detect ACSS2 mRNA expression. Methyl thiazolyl tetrazolium (MTT), lfow cytometry and wound healing assay were used to detect cell proliferation, apoptosis rate and migration.Results:The expression of ACSS2 mRNA was signiifcantly decreased after transfection with the interference fragment ACSS2-siRNA in NSCLC cell line A549. The proliferation and migration activity of ACSS2-siRNA treated cells were decreased significantly compared with the control group. The apoptosis rate, especially the early apoptosis, was increased..Conclusion:Knockdown of the ACSS2 expression in NSCLC cell line A549 can signiifcantly inhibit the cell proliferation, migration ability and pro-mote the apoptosis rate, especially early apoptosis. This study indicates that ACSS2 may contribute to the progression of human lung adenocarcinoma and may have the potential to serve as a novel therapeutic target.

BACKGROUND:There are currently various surgical methods of patel a fracture, and they have advantages and disadvantages, thus cannot wel meet the requirements of patients.
OBJECTIVE:To evaluate biomechanical properties of internal fixation plate to treat patel ar fracture and to provide theoretical evidence for clinical application.
METHODS:According to the statistics of patel a in the Chinese population, a titanium al oy spider internal fixation plate was designed and manufactured for the treatment of patel ar fractures. Knee joint specimens in six fresh cadavers were randomly divided into two groups and the comminuted fracture model of patel a were established. The models were fixed with internal fixation plate of patel a and NiTi patel ar concentrator. Biomechanical tests were carried out to compare the biomechanical properties.
RESULTS AND CONCLUSION:Both the two fixation methods could meet the 1-kN quadriceps femoris contraction. The internal fixation plate of patel a was superior to NiTi patel ar concentrator in the patel ar isolation shift, muscle strength and joint strength, as wel as mechanical properties of patel a-point surface. There were significant differences between the two groups (P<0.05). The internal fixation plate of patel a is designed in accordance with the anatomical and biomechanical properties of the patel a, the fixation strength can completely meet clinical requirement and deserve further application.