Biomechanical response of postural kyphosis under the action of bending moments / 中国组织工程研究

BACKGROUND:Most of the biomechanical studies on kyphosis have focused on trunk muscle strength and sagittal plane balance,and little has been reported on the biomechanical response within the spine during kyphosis. OBJECTIVE:To investigate the biomechanical response of the spine during postural kyphosis by simulating the process of postural kyphosis. METHODS:A three-dimensional finite element model of the normal thoracolumbar segment(T1-S1 segment)was established by using the finite element method.10 groups of pure bending loads from 1.15-11.52 N·m were applied using a three-point force system on T1,T6,and T12 vertebrae to simulate the process of postural kyphosis in normal humans.The relationship between the loads and Cobb angle and the biomechanical responses of vertebrae,ribs,and intervertebral discs were analyzed. RESULTS AND CONCLUSION:(1)During postural kyphosis,the Cobb angle size of T1-T12 segments was linearly related to the load size.(2)The maximum stresses on the vertebrae,ribs,and intervertebral discs increased with increasing load.(3)Under the action of 11.52 N·m moment,the maximum stresses on the vertebral body,ribs,and intervertebral disc were found in the front of the T6 vertebral body,the rib head of the 10th pair of ribs,and the right posterior side of the intervertebral disc of the T5-T6 segments.(4)The results of this study suggest that postural kyphosis leads to increased stress on the vertebrae,ribs,and discs,with the most significant increase in stress on the anterior side of the T6 vertebrae,at the rib head of the 10th pair of ribs,and on the anterior side of the disc at the T5-T6 segment,as well as on the posterior side,which may increase the risk of injury to the vertebrae,ribs,and discs,which provides a biomechanical basis for the design of kyphosis orthoses.

Bionic optic nerve based on perovskite (CsPbBr 3) quantum-dots / 生物医学工程学杂志

The bionic optic nerve can mimic human visual physiology and is a future treatment for visual disorders. Photosynaptic devices could respond to light stimuli and mimic normal optic nerve function. By modifying (Poly(3,4-ethylenedioxythio-phene):poly (styrenesulfonate)) active layers with all-inorganic perovskite quantum dots, with an aqueous solution as the dielectric layer in this paper, we developed a photosynaptic device based on an organic electrochemical transistor (OECT). The optical switching response time of OECT was 3.7 s. To improve the optical response of the device, a 365 nm, 300 mW·cm -2 UV light source was used. Basic synaptic behaviors such as postsynaptic currents (0.225 mA) at a light pulse duration of 4 s and double pulse facilitation at a light pulse duration of 1 s and pulse interval of 1 s were simulated. By changing the way light stimulates, for example, by adjusting the intensity of the light pulses from 180 to 540 mW·cm -2, the duration from 1 to 20 s, and the number of light pulses from 1 to 20, the postsynaptic currents were increased by 0.350 mA, 0.420 mA, and 0.466 mA, respectively. As such, we realized the effective shift from short-term synaptic plasticity (100 s recovery of initial value) to long-term synaptic plasticity (84.3% of 250 s decay maximum). This optical synapse has a high potential for simulating the human optic nerve.

Four Properties of Chinese Herbal Medicine： A Review / 中国实验方剂学杂志

The four properties of Chinese herbal medicine have a history of several thousand years and are one of the important theoretical guides for the clinical application of Chinese herbal medicine. However， there have been few reviews of research methods and techniques for the four properties of Chinese herbal medicine in recent years. Therefore， this article summarized the advances and techniques for the four properties of Chinese herbal medicine by screening relevant literature on the four properties of Chinese herbal medicine and clarifying the characteristics， advantages， and applicable objects of each technique， in order to provide references for in-depth research on the four properties in the future. Chinese databases such as China national knowledge infrastructure （CNKI）， Wanfang data， and VIP， as well as international databases including PubMed， Cochrane Library， and EMbase were searched for relevant literature on the four properties of Chinese herbal medicine. The advances， research objects， and research techniques involved in the literature were extracted， classified， and summarized. Currently， the research techniques for the four properties of Chinese herbal medicine mainly include six categories， i.e.， literature data research， network pharmacology， biothermodynamics， cell biology， proteomics， and metabolomics. The research hierarchy can be divided into micro-level， small-level， medium-level， and macro-level. The research objects used in each experimental study are different， mainly single Chinese herbal medicine， Chinese herbal monomers， targets， microbial communities， cells， mice， and rats. Different research techniques explain the four properties of Chinese herbal medicine from different dimensions， which overall indicate the material basis of the four properties of Chinese herbal medicine. In future research， the interpretation of the four properties of Chinese herbal medicine can be first located at the research hierarchy， then corresponding research techniques can be selected according to the research hierarchy， and research indicators can be determined to obtain research conclusions. This can help researchers of traditional Chinese medicine effectively carry out research design and perform related experiments on the four properties of Chinese herbal medicine.

A Study on the Correlation between Preeclampsia and Carbon Metabolism in Dichorionic Diamniotic Twin Pregnancy / 实用妇产科杂志

Objective:To explore the correlation between choline,betaine,dimethylglycine,methionine and tri-methylamine oxide,metabolites related to the methionine cycle in carbon metabolism,and preeclampsia(PE)in di-chorionic diamniotic(DCDA)twin pregnancy.Methods:175 pregnant women with twin pregnancies who under-went regular prenatal examinations were registered in Peking University Third Hospital from July 2017 to April 2019 were included as the study subjects.According to whether PE had occurred,they were divided into non-PE group(138 cases)and PE group(37 cases).The fasting peripheral blood of pregnant women during the second trimester of pregnancy was collected,and the metabolites were quantitatively analyzed by ultra-high performance liquid chromatogrey-triple quadrupole tandem mass spectrometry(UHPLC-QqQ MS).The basic characteristics and plasma metabolite concentrations were compared between PE group and non-PE group.Poisson regression was used for plasma metabolite-related PE relative risk(RR)analysis,and receiver operating characteristic(ROC)curve was used to evaluate the accuracy of PE model prediction.Results:①Compared with the non-PE group,the rate of elderly pregnant women was higher,the concentration of betaine was lower,and the concentra-tion of choline was higher in PE group.The differences were statistically significant(P＜0.05).②Poisson regres-sion analysis showed that in the model adjusted for all confounding factors,there was a positive correlation be-tween maternal choline levels and PE risk(RR＞1,P＜0.05).The risk of PE occurrence increased as the in-crease of choline levels(Ptrend＜0.05).Betaine levels were negatively associated with PE risk(RR＜1,P＜0.05).The risk of PE occurrence decreased as the increase of betaine level(Ptrend＜0.05).There was no corre-lation between plasma levels of dimethylglycine,methionine and trimethylamine oxide and the risk of PE.③Pois-son regression analysis showed that the relative risk of PE was lowest when the plasma betaine/choline ratio was highest(RR0.32,95％Cl 0.14-0.75).When the dimethylglycine/betaine ratio was in the thirdpercentile,the risk of PE was increased in pregnant women(RR 2.53,95％Cl 1.01-6.32).(4)ln terms of PE prediction,the AUC combined with general risk factors and methionine metabolites was 0.80.Conclusions:Maternal choline and be-taine levels in the second trimester are related to the occurrence of PE in DCDA twin pregnancy,and provide a new idea for early prediction and intervention of PE.It is still necessary to expand the sample size to further verify and explore the mechanism.

Quantitative analysis on the policy text for free training of rural order-oriented medical students of China / 中华医院管理杂志

Objective:To analysis the policy tools and targets of the policies of free training for order-oriented medical students in rural areas of China, for reference for further improving the free medical student training policy.Methods:The research team searched the official websites of the State Council, National Health Commission, Ministry of Education, and other ministries, as well as the Peking University Treasure Database, for national level policy documents related to free training of order-oriented medical students released from June 2010 to May 2023. Policy tool-policy target analysis framework was used to quantitative analysis the policy documents.Results:A total of 16 policy documents were included and 213 policy provisions were extracted. From the perspective of policy tools, the proportion of policy provisions using imperative policy tools was the highest, accounting for 63.38% (135 articles), followed by advisory policy tools(18.78%, 40 articles)and reward based policy tools(13.61%, 29 articles), while functional expansion tools(2.82%, 6 articles) and authoritative restructuring tools(1.41%, 3 articles) accounted for a relatively low proportion. The institutional education stage is the main policy target, with provisions accounting for 76.06% (162 articles), followed by the continuing education stage and the post graduation education stage, accounting for 17.84% (38 articles) and 7.51% (16 articles), respectively. It was uneven distribution of various policy tools and their sub tools within the same policy target.Conclusions:The distribution of policy tools for the free training policy of rural order oriented medical students in China needed to be further balanced. The policy targets were mainly concentrated in the education stage of universities.

Stevens-Johnson syndrome secondary to massive inflammatory hyperplasia of bilateral lingual margins: a case report and literature review / 华西口腔医学杂志

Stevens-Johnson syndrome (SJS), also known as the multifactorial erythematous drug eruption, is a class of adverse reactions of the skin and mucous membranes primarily caused by drug allergy often involving the oral cavity, eyes, and external genital mucosa, generally accompanied by fever, and can be life-threatening in severe cases. In February 2022, the Department of Stomatology, the First Affiliated Hospital of Zhengzhou University admitted a patient with huge inflammatory hyperplasia of bilateral lingual margins secondary to SJS. Upon admission, no other obvious symptoms were observed except for tongue hyperplasia. The patient suffered from a severe adverse drug reaction caused by acetaminophen 2 months ago and was complicated by liver dysfunction and pulmonary infection. After 1 month of treatment and rehabilitation, he developed a secondary tongue mass and was subsequently admitted to Dept. of Oral and Maxillofacial Surgery Ward 2, the First Affiliated Hospital of Zhengzhou University. After completing the examination, the tongue mass was surgically removed. After a follow-up of 11 months, the patient's condition was satisfactory and no temporary discomfort was observed. The case of tongue mass secondary to SJS is extremely rare. If a stomatologist encounters a similar case, we should carefully inquire about the drug allergy history and recent medication history, and be alert to whether or not they had adverse drug reactions recently.

Effects of lifestyle changes on body weight and metabolic parameters during the early stage of COVID-19 epidemic and regular epidemic prevention period in physical examination population / 中华健康管理学杂志

Objective:To analyze the influence of lifestyle changes on body weight and metabolic parameters during the early stage of corona virus disease 2019 (COVID-19) epidemic and regular epidemic prevention period in physical examination population.Methods:A total of 801 subjects from Nanjing enterprises and institutions who underwent physical examination in the Department of Health Promotion Center, the First Affiliated Hospital of Nanjing Medical University in May of 2019 to 2021 were included in this study. The basic information and data of body mass index, fasting blood glucose, total cholesterol, low density lipoprotein cholesterol (LDL-C), triglyceride and uric acid were collected. Information about dietary and exercise habits was obtained through pre-examination questionnaires. The data of 2019 was set as baseline data, data of 2020 represented information during the early stage of COVID-19 epidemic and data of 2021 represented information in regular epidemic prevention period. The subjects were divided into underweight group, normal weight group, overweight group, and obese group according to the body mass index at baseline. The Friedman test was applied to compare changes in body mass index and metabolic parameters across the population. Chi-square test was used to compare changes in dietary and exercise habits. Multivariate logistic regression analysis was adopted to explore the influencing factors of body mass index changes.Results:During the early stage of COVID-19 epidemic, the proportion of weight gain was the highest in the underweight group (42.9%), the proportion of weight loss was the highest in the overweight group (24.2%), and the obese group has the most stable body weight (70.6%) ( P=0.004). Men ( OR=0.56, 95% CI: 0.36-0.87) were less likely to gain weight than women ( P=0.010). There was no significant differences in weight change among all groups in the regular epidemic prevention period ( P=0.380). During the early stage of COVID-19 epidemic, the levels of fasting blood glucose, total cholesterol and LDL-C were significantly lower than those of baseline [4.98 (4.66, 5.42) vs 5.23 (4.91, 5.66) mmol/L, 4.98 (4.36, 5.67) vs 5.11 (4.54, 5.77) mmol/L, 2.90 (2.45, 3.33) vs 3.23 (2.77, 3.74) mmol/L], and the uric acid level was higher [333.0 (275.5, 397.0) vs 311.0 (257.5, 368.0) μmol/L] (all P<0.001). In regular epidemic prevention period, the levels of body mass index, fasting blood glucose, total cholesterol and LDL-C were significantly higher than those in the early stage of the epidemic [24.0 (21.9, 26.3) vs 23.8 (21.7, 26.1) kg/m 2, 5.18 (4.85, 5.62) vs 4.98 (4.66, 5.42) mmol/L, 5.12 (4.42, 5.76) vs 4.98 (4.36, 5.67) mmol/L, 3.06 (2.59, 3.57) vs 2.90 (2.45, 3.33) mmol/L], while the uric acid was significantly lower [319.0 (265.0, 377.0) vs 333.0 (275.5, 397.0) μmol/L] (all P<0.001). During the early stage of the epidemic, the reduction proportion of unhealthy diet in the home group was significantly higher than that in the outing group (19.5% vs 11.4%), and the increment proportion of exercise in the outing group was significantly higher than that in the home group (5.1% vs 1.6%) (both P<0.05). In regular epidemic prevention period, the increase rate of unhealthy diet in the home group was significantly higher than that in the outing group (26.8% vs 13.0%) ( P<0.001), and there was no significant difference in exercise between the two groups ( P=0.325). During the early stage of COVID-19 epidemic and in the regular epidemic prevention period, unhealthy diet>3 times per week ( OR=3.85, 3.01, 95% CI: 1.74-8.51, 1.41-6.39) was positively correlated with weight gain, and regular exercise ( OR=4.35, 2.61, 95% CI: 2.05-9.23, 1.15-5.91) was positively correlated with weight loss (all P<0.05). Conclusions:During the early stage of COVID-19 epidemic and in the regular epidemic prevention period, the lifestyle in the physical examination population has an impact on body weight and metabolic indicators. In the early stage of the epidemic, unhealthy diet and exercise decreased, and metabolic indicators such as blood glucose and lipids decreased. People with low body weight tend to gain weight. In the regular epidemic prevention period, the subjects′ exercise increased but unhealthy diet also increased, and blood glucose, lipid and body weight elevated significantly.

Application effect of intelligent education model in the health management of the smokers with high-risk of chronic obstructive pulmonary disease / 中华健康管理学杂志

Objective:To explore the application effect of the intelligent interactive health education model in the health management of the smokers with high-risk of chronic obstructive pulmonary disease (COPD).Methods:From September 2019 to January 2020, 72 smokers with high-risk of COPD were recruited from Health Management Center, the First Affiliated Hospital of Nanjing Medical Universit y. The subjects were randomly divided into traditional group (35 cases) and intelligent group (37 cases) according to the intervention model. The traditional group used the method of mailing health education materials, while the intelligent group sent health education materials with the help of mobile intelligent platform for interactive feedback and intervention. After 12 weeks of intervention, the subjects′ nicotine dependence, international physical activity, population satisfaction, time consumption for follow-up and other indicators were compared. Results:After the intervention, the score of nicotine dependence in the intelligent group was lower than that in the traditional group [(1.86±1.48) vs (3.77±1.66), P<0.05], the number of smoking cessation cases was more than that in the traditional group (11 vs 1, P<0.05), the number of cases with significant improvement in the score of international physical strength scale was significantly improved than that in the traditional group (15 vs 0, P<0.01), and the satisfaction was higher than that in the traditional group (97.30% vs 42.85%, P<0.01), and the time consumption was less than that in the traditional group [(18.03±2.96) vs (25.14±2.64) min, P<0.01]. Conclusion:The intelligent interactive health education model can improve the health education effect of the smokers with high risk of developing COPD, and improve the health behavior of the population.

Inhibition of gasdermin D-dependent pyroptosis attenuates the progression of silica-induced pulmonary inflammation and fibrosis

Silicosis is a leading cause of occupational disease-related morbidity and mortality worldwide, but the molecular basis underlying its development remains unclear. An accumulating body of evidence supports gasdermin D (GSDMD)-mediated pyroptosis as a key component in the development of various pulmonary diseases. However, there is little experimental evidence connecting silicosis and GSDMD-driven pyroptosis. In this work, we investigated the role of GSDMD-mediated pyroptosis in silicosis. Single-cell RNA sequencing of healthy and silicosis human and murine lung tissues indicated that GSDMD-induced pyroptosis in macrophages was relevant to silicosis progression. Through microscopy we then observed morphological alterations of pyroptosis in macrophages treated with silica. Measurement of interleukin-1β release, lactic dehydrogenase activity, and real-time propidium iodide staining further revealed that silica induced pyroptosis of macrophages. Additionally, we verified that both canonical (caspase-1-mediated) and non-canonical (caspase-4/5/11-mediated) signaling pathways mediated silica-induced pyroptosis activation, in vivo and in vitro. Notably, Gsdmd knockout mice exhibited dramatically alleviated silicosis phenotypes, which highlighted the pivotal role of pyroptosis in this disease. Taken together, our results demonstrated that macrophages underwent GSDMD-dependent pyroptosis in silicosis and inhibition of this process could serve as a viable clinical strategy for mitigating silicosis.

β-lactam antibiotics detection using microcolumn gel technology / 中国输血杂志

【Objective】 To develop an assay to determine β-lactam antibiotics using microcolumn gels and to study the β-lactam antibiotics present in the blood of patients and their clinical significances. 【Methods】 446 patients with a history of taking β-lactam antibiotics from January 2019 to June 2019 were randomly selected from Trauma Emergency Center, Department of Arthrosis, Department of Spine and Department of Bone Oncology of our hospital, and 4 mL(per capita) venous blood was collected. Irregular antibody screening, anti-globulin detection and drug antibody determination were performed by microcolumn gel method. The data of gender, age, disease, blood transfusion history and medication were collected. The test results and clinical data were retrospective analyzed. 【Results】 The yielding rate of antibody was 0.45%(2/446) in patients with a history of taking β -lactam antibiotics. 16.38%(73/446) of the samples were positive in direct antiglobulin test, and 64.38%(47/73) of them did not agglutinate with RBCs treated with drugs. The yielding rate of specific antibodies against drug was 4.93%(22/446), and the titer ranged from 2 to 128(8). 1 case of auto-IgM antibody, 1 case of blood group related antibody and 2 cases of non-specific protein adsorption were detected. The yielding rate of drug antibody in patients with blood transfusion history reached to 12.10 %(22/124), so it was also high in patients with bone tumor. 【Conclusion】 Direct antiglobulin assay is helpful for the detection of β-lactam antibodies. The negative results of antibody screening cannot completely exclude the presence of drug antibodies. The yielding rate of drug antibody can be greatly improved by specific drug antibody detection, and it was higher in transfused patients relative to non-transfused one.

The effect of parasitic ions on riboflavin permeability and cross-linking effectiveness in iontophoresis-assisted scleral cross-linking / 生物医学工程学杂志

The effect of parasitic ions on the results of ultraviolet A (UVA) cross-linking in iontophoresis was still not clear. In this work, the porcine sclera was cross-linked by riboflavin lactate Ringer's solution (group A) and riboflavin normal saline (group B)

Finite element analysis of the effect of local posterior sclera collagen cross-linking on eyeball shape / 生物医学工程学杂志

China is the country with high incidence of high myopia in the world. High myopia can cause severe vision impairment. So far, there is no effective treatment for high myopia in clinic. Scleral collagen cross-linking surgery has been proven to be effective in preventing animal eye axial elongation

Down-regulation of lncRNA SNHG6 inhibits breast cancer progression by targeting miR-30-5p/FKBP3 axis / 中华内分泌外科杂志

Objective:To investigate the relationship between lncRNA SNHG6 and breast cancer and its possible mechanism.Methods:Fluorescence quantitative PCR was used to detect the expression of SNHG6, miR-30-5p, and FKBP3 in human normal breast epithelial cell line MCF-10A and human breast cancer cell line MCF-7. According to the experiment content, MCF-7 cells were divided into the following groups:① si-NC group, si-SNHG6 group, si-NC+miR-30-5p inhibitor group and si-SNHG6+miR-30-5p inhibitor group;②miR-NC group, miR-30-5p inhibitor group, miR-30-5p inhibitor+sh-NC group and miR-30-5p inhibitor+sh-FKBP3 group. The expression of SNHG6 was inhibited by siRNA technology, and the miR-30-5p mimic (mimic) , inhibitor (inhibitor) and negative control (miR-NC) were transfected into MCF-7 cells by liposome-mediated method. A short hairpin RNA (shRNA) lentiviral expression vector targeting FKBP3 gene was constructed to inhibit FKBP3 expression. CCK-8, cell colony formation experiment, cell wound healing experiment and Transwell experiment were used to observe the proliferation, migration and invasion of MCF-7 cells in each group. Bioinformatics software, dual luciferase reporter gene experiment and Western blotting were used to analyze the targeting relationship between SNHG6 and miR-30-5p, miR-30-5p and FKBP3.Results:Compared with MCF-10A cells, the expression levels of SNHG6 and FKBP3 in MCF-7 cells increased significantly, while the expression levels of miR-30-5p decreased significantly ( t=21.097, P=0.000; t=17.812, P=0.000; t=33.671, P=0.000) . Compared with si-NC group, the proliferation activity of MCF-7 cells in the si-SNHG6 group was significantly inhibited ( t=19.569, P=0.000; t=25.077, P=0.000) , and the number of cell colonies formed significantly decreased ( t=34.071, P=0.000) . Migration and invasion of cells were also inhibited ( t=33.419, P=0.000; t=29.372, P=0.000) . There were complementary binding sites between miR-30-5p and SNHG6. The luciferase activity of miR-30-5p mimic and SNHG6-WT co-transfected group was significantly lower than that of miR-NC and SNHG6-WT co-transfected group ( t=31.596, P=0.000) . The proliferation, migration and invasion of MCF-7 cells in each group were significantly different ( F=268.014, F=398.483, F=244.962) . Compared with si-SNHG6 group, the proliferation, migration and invasion ability of MCF-7 cell in si-SNHG6+miR-30-5p inhibitor group increased significantly ( P=0.000) ; Compared with si-NC+miR-30-5p inhibitor group, the proliferation, migration and invasion ability of MCF-7 cells in si-SNHG6+miR-30-5p inhibitor group decreased significantly ( P=0.000) . There were complementary binding sites between miR-30-5p and 3’UTR of FKBP3. The luciferase activity of miR-30-5p mimic and FKBP3-WT co-transfected group was significantly lower than that of miR-NC and FKBP3-WT co-transfected group ( t=28.557, P=0.000) . After transfection, the FKBP3 protein expression of MCF-7 cells in each group was significantly different ( F=102.523) . Compared with miR-NC group, FKBP3 protein expression of miR-30-5p mimic group was significantly reduced, while FKBP3 protein expression of miR-30-5p inhibitor group was significantly increased ( P=0.000) . The proliferation, migration and invasion of MCF-7 cells in each group were significantly different ( F=177.036, F=285.530, F=217.992) . Compared with miR-30-5p inhibitor group and miR-30-5p inhibitor+sh-NC group, the proliferation, migration and invasion ability of MCF-7 cells in miR-30-5p inhibitor+sh-FKBP3 group was significantly decreased ( P=0.000 ) . Conclusion:Inhibiting the expression of miR-30-5p can reverse the inhibitory effect of down-regulation of SNHG6 on the proliferation, migration and invasion of MCF-7 cells.

Finite element analysis of determining corneal biomechanical properties in vivo based on Corvis ST / 生物医学工程学杂志

The decrease of corneal stiffness is the key factor leading to keratoconus, and the corneal collagen fiber stiffness and fiber dispersion are closely related to the corneal biomechanical properties. In this paper, a finite element model of human cornea based on corneal microstructure, namely collagen fiber, was established before and after laser assisted in situ keratomileusis (LASIK). By simulating the Corvis ST process and comparing with the actual clinical results, the hyperelastic constitutive parameters and corneal collagen fiber stiffness modulus of the corneal material were determined before and after refractive surgery. After LASIK, the corneal collagen fiber stiffness modulus increased significantly, and was highly correlated with central corneal thickness (CCT). The predictive relationship between the corneal collagen fiber stiffness modulus and the corresponding CCT before and after surgery was: = exp(9.14 - 0.009CCT ), = exp(8.82 - 0.008CCT ). According to the results of this study, the central corneal thickness of the patient can be used to estimate the preoperative and postoperative collagen fiber stiffness modulus, and then a personalized corneal model that is more consistent with the actual situation of the patient can be established, providing a theoretical reference for more accurately predicting the safe surgical cutting amount of the cornea.

A comparative study of viscoelasticity between normal cornea and keratoconus / 生物医学工程学杂志

Study of the mechanical properties of in vivo corneal materials is an important basis for further study of corneal physiological and pathological phenomena by means of finite element method. In this paper, the elastic coefficient ( ) and viscous coefficient ( ) of normal cornea and keratoconus under pulse pressure are calculated by using standard linear solid model with the data provided by corneal visualization scheimpflug technology. The results showed that there was a significant difference of and between normal cornea and keratoconus cornea ( < 0.05). Receiver operating characteristic curve analysis showed that the area under curve (AUC) for , and their combined indicators were 0.776, 0.895 and 0.948, respectively, which indicated that keratoconus could be predicted by and . The results of this study may provide a reference for the early diagnosis of keratoconus and avoid the occurrence of keratoconus after operation, so it has a certain clinical value.

Experimental study on mechanical properties of the ventral and the dorsal tissues of porcine descending aorta / 生物医学工程学杂志

The mechanical properties of the aorta tissue is not only important for maintaining the cardiovascular health, but also is closely related to the development of cardiovascular diseases. There are obvious differences between the ventral and dorsal tissues of the descending aorta. However, the cause of the difference is still unclear. In this study, a biaxial tensile approach was used to determine the parameters of porcine descending aorta by analyzing the stress-strain curves. The strain energy functions Gasser-Ogden-Holzapfel was adopted to characterize the orthotropic parameters of mechanical properties. Elastic Van Gieson (EVG) and Sirius red stain were used to observe the microarchitecture of elastic and collagen fibers, respectively. Our results showed that the tissue of descending aorta had more orthotropic and higher elastic modulus in the dorsal region compared to the ventral region in the circumferential direction. No significant difference was found in hyperelastic constitutive parameters between the dorsal and ventral regions, but the angle of collagen fiber was smaller than 0.785 rad (45°) in both dorsal and ventral regions. The arrangement of fiber was inclined to be circumferential. EVG and Sirius red stain showed that in outer-middle membrane of the descending aorta, the density of elastic fibrous layer of the ventral region was higher than that of the dorsal region; the amount of collagen fibers in dorsal region was more than that of the ventral region. The results suggested that the difference of mechanical properties between the dorsal and ventral tissues in the descending aorta was related to the microstructure of the outer membrane of the aorta. In the relatively small strain range, the difference in mechanical properties between the ventral and dorsal tissues of the descending aorta can be ignored; when the strain is higher, it needs to be treated differently. The results of this study provide data for the etiology of arterial disease (such as arterial dissection) and the design of artificial blood vessel.

Training effect of case-based learning on post competency of medical students in the teaching of medical chemistry / 中华医学教育探索杂志

Objective To investigate the training effect of the case-based learning (CBL) teaching method on post competency of medical students. Methods Four classes of students majoring in nursing in China Medical University were enrolled and divided into experimental group and control group, with two classes in each group. In the teaching of medical chemistry, the CBL teaching method was adopted for the experimental group and the traditional teaching method was adopted for the control group, with the same teacher and teaching materials. Questionnaire survey and final examination were performed to assess the effect of the CBL teaching method on post competency of medical students, and SPSS 20.0 software was used for data analysis. Results The results of the questionnaire survey showed that the experimental group had better assessment indices of post competency. The results of the final examination showed that the experimental group had a significantly higher mean score of medical chemistry than the control group [(73.5 ±10.3) vs. (68.1 ±9.1)]. Conclusion The application of the CBL teaching method in medical chemistry can effectively improve the learning outcomes of medical students and train their post competency, and therefore, it holds promise for application in the teaching of basic medicine.

To explore the preventive and therapeutic effects of Xuebijing injection on acute lung injury induced by cardiopulmonary bypass in rats by regulating the expression of microRNA-17-5p and its mechanism / 中华危重病急救医学

Objective To investigate the preventive effect of Xuebijing injection on acute lung injury induced by cardiopulmonary bypass (CPB) and the underlying mechanism. Methods ① In vivo experiment: 30 Sprague-Dawley (SD) rats were randomly divided into sham group, CPB group, Xuebijing pretreatment group (XBJ+CPB group) with 10 rats in each group. CPB model was reproduced in rats; and CPB was not performed in sham group, but only through arteriovenous puncture. In the XBJ+CPB group, 4 mL/kg Xuebijing injection was injected intraperitoneally 2 hours before CPB, sham group and CPB group were injected with equal volume of normal saline at the same time. The blood from femoral artery was analyzed 4 hours after operation, and the oxygenation index (PaO2/FiO2) was calculated. Then the rats were sacrificed to collect bronchoalveolar lavage fluid (BALF), and the lung permeability index (PPI) was calculated. The lung tissues were harvested, and the wet/dry weight ratio (W/D) of lung tissue was measured. The index of quantitative evaluation of alveolar injury (IQA) was measured. The levels of interleukins (IL-1, IL-6) and tumor necrosis factor-α(TNF-α) in lung tissue and BALF were measured by enzyme-linked immunosorbent assay (ELISA). The content of malondialdehyde (MDA) and the activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) in lung tissue were detected by biochemical method. The microRNA-17-5p (miR-17-5p) expression in lung tissue was determined by quantitative reverse transcription-polymerase chain reaction (RT-qPCR).② In vitro experiments: type Ⅱ alveolar epithelial cells (AECⅡ) were cultured in vitro, and they were randomly divided into control group (the cells were treated by preoperative serum of CPB in patients with ventricular septal defect), CPB group (the cells were treated by serum after CPB in patients), and XBJ+CPB group (Xuebijing injection 10 g/L+serum after CPB in patients). After 12 hours of culture in each group, the expression of miR-17-5p was detected by RT-qPCR. AECⅡ cells were transfected with miR-17-5p mimic, inhibitor or corresponding control oligonucleotide (negative control), respectively, to observe the effect of miR-17-5p on Xuebijing regulating CPB-induced apoptosis rate and caspase-3 activity. Results ① In vivo experiment: compared with the sham group, the PPI, lung W/D ratio, IQA, and IL-1, IL-6, TNF-α in lung tissue and BALF, as well as MDA content and MPO activity in lung tissue were significantly increased, PaO2/FiO2 and SOD activity in lung tissue were significantly decreased. The parameters of the XBJ+CPB group were significantly improved, suggesting that Xuebijing pretreatment could improve CPB-induced ALI in rats. The expression of miR-17-5p in lung tissue of the CPB group was significantly down-regulated as compared with sham group (2-ΔΔCt: 0.48±0.13 vs. 1.00±0.11, P < 0.05);while the expression of miR-17-5p in the XBJ group was significantly up-regulated as compared with the CPB group (2-ΔΔCt: 1.37±0.09 vs. 0.48±0.13, P < 0.05), indicating that the improvement of Xuebijing injection on lung injury after CPB might be related to miR-17-5p. ② In vitro experiment: the changes in miR-17-5p expression in each group of AECⅡ cells confirmed in vivo results. After transfection of miR-17-5p mimic, the apoptotic rate and caspase-3 activity of each group were significantly lower than those transfected with negative control, and the decrease was more significant in the XBJ+CPB group [apoptotic rate: (7.37±0.95)% vs. (12.60±1.90)%, caspase-3 (A value): 0.82±0.09 vs. 1.37±0.08, both P < 0.05]. After transfection of miR-17-5p inhibitor, the apoptotic rate and caspase-3 activity of each group were significantly more than those transfected with negative control [in the XBJ+CPB group: apoptotic rate was (16.30±1.86)% vs. (12.60±1.90)%, caspase-3 (A value) was 1.78±0.13 vs. 1.37±0.08, both P < 0.05]. This indicated that the apoptosis of AECⅡ cells cultured in serum after CPB was significantly reduced by miR-17-5p, and further reduced by the pretreatment with Xuebijing. Conclusions Xuebiing injection can reduce the inflammatory reaction and oxidative stress of lung tissue in rats with ALI induced by CPB, and improve oxygenation. The mechanism may be related to up-regulation of miR-17-5p expression in AECⅡ cells and inhibition of apoptosis of AECⅡ cells.

Microcalcification and vulnerability of atherosclerotic plaques / 国际脑血管病杂志

It has been previously thought that calcification is a feature of the stability of atherosclerotic plaques. However, recent studies have shown that microcalcification in atherosclerotic plaques is significantly associated with plaque vulnerability. The relationship between atherosclerotic plaques and calcification is unclear, and the specific role of calcification in atherosclerotic plaques remains controversial.

Radiographic classification of tarsometatarsal joint dislocation and postoperative imaging evaluation / 实用放射学杂志

Objective To study radiographic classification of tarsometatarsal joint dislocation and postoperative imaging evaluation.Methods 74 patients with tarsometatarsal joint dislocation were included in this study.Tarsometatarsal joint dislocations were classified by the Myerson fracture displacements classification.All patients were evaluated according to the American Orthopedics Foot & Ankle Society (AOFAS)clinical rating systems.Results There were 19 patients with Myerson A,46 patients with Myerson B and 9 patients with Myerson C tarsometatarsal joint dislocation.39 distal tarsal bone fractures and 156 metatarsal fractures,with simultaneous scaphoid fractures in 10 patients were showed.All patients who were followed up and no infection.The AOFAS scale was categorized as excellent,good,fair or poor,and 22 patients were considered as excellent,29 patients as good,17 patients as fair and 6 patients as poor.Postoperative imaging evaluation required anatomical reduction of tarsometatarsal joint.On the anteroanterior radiogragh,the base medial edge of the second metatarsal bone and the medial edge of intermediate cuneiform were combined to form a straight line.The shortest distance between the base of the first metatarsal bone and the second metatarsal bone should be less than 2 mm.On the medial oblique radiogragh,a smooth line connecting the medial edge of the fourth metatarsal bone with the medial edge of cuboid bone always appeared.On the lateral radiogragh,the dorsal edge of the second metatarsal bone and intermediate cuneiform formed a smooth line.The height of metatarsus should not exceed the dorsal edge of corresponding cuneiform.The longitudinal arch angle was restored within normal limits.Conclusion The type-B tarsometatarsal joint dislocation is the most common type and frequently accompanies by multiple fractures.Intraoperative and postoperative multidirectional observation of anatomical reduction of tarsometatarsal joint dislocation can reduce incidence of posttraumatic arthritis.