Objective To establish an HPLC method for evaluating deoxyschizandrin in rat plasma; To explore deoxyschizandrin metabolic processes in blood.Methods The blood microdialysis probe was implanted into the right atrial enlargement through right jugular vein to detect the concentration of deoxyschizandrin in blood. Chromatographic conditions for detecting of dialysis fluid were as follows: mobile phase was methanol-acetonitrile- water (40:35:25); flow rate was 1 mL/min; column temperature was 30℃; UV detection wavelength was 254 nm. The data obtained after being calculated by the recovery rate of the probe in vivo were dealt with DAS 2.0 software. Pharmacokinetic parameters were calculated, and the concentration-time related curves were plotted.Results The deoxyschizandrin curve was linear (r=0.999 5) within the range of 2–500μg/mL. The RSD of intra-day pecision and inter-day pecision were both <3%. The stability of the solution was good in 12 hours at roomtemperature. ke was (0.364±0.047)/h; t1/2 was (1.637±0.302)h; Tmax was (0.612±0.194)h; Cmax was (165.92±28.830)μg/mL; AUC0-t was (240.793±25.540)μg?h/mL; AUC0-∞ was (282.710±30.727)μg?h/mL.Conclusion The method is convenient to perform, and the retention time of HPLC is short. This method is suitable for detecting the content of deoxyschizandrin in dialysis fluid, which can also be used to investigate the metabolic processes of deoxyschizandrin in the rat blood.

BACKGROUND:Neural stem cel s with self-proliferation and differentiation potential are the ideal seed cel s for central nervous tissue engineering. Although col agen and silk fibroin as biological scaffold materials have been widely used, both of them used alone have certain shortcomings. Is it possible to combine the two materials to build a novel neural tissue-engineered scaffold? What is the effect of this novel scaffold on the growth and differentiation of neural stem cel s? OBJECTIVE:To observe the growth and differentiation of neural stem cel s seeded onto the novel composite scaffold. METHODS:The rat embryonic neural stem cells were inoculated onto new composite scaffolds, and then, their growth and differentiation were observed by light microscopy and scanning electron microscopy. Neural stem cells were cultured in conventional suspension culture as control group. Cell counting kit-8 assay was used to detect viability of neural stem cells in the two groups. Three-dimensional composite scaffolds carrying neural stem cells were slic ed into paraffin sections to observe the growth and differentiation of neural stem cells by hematoxylin-eosin staining and immunofluorescence staining. RESULTS AND CONCLUSION:Neural stem cel s cultured on the new composite scaffold grew and differentiated wel , and interconnected synapses were observed. Cel counting kit-8 assay showed that neural stem cel s on the scaffold grew wel , and the cel viability was significantly higher in the composite scaffold group than that in the control group (P<0.05). Hematoxylin-eosin staining and immunofluorescence staining of paraffin sections further provided evidence for good growth and differentiation of neural stem cel s on the scaffold. These results indicate that the novel composite scaffold with good biocompatibility benefits the growth and differentiation of neural stem cel s, promising a favorable application prospect.

BACKGROUND:Peripheral nerve defect due to limb dysfunction has always been the difficulty faced by the medical profession. Ideal materials and processing technology for constructing a tissue engineering scaffold targeting peripheral nerve repair are stil in research stage. OBJECTIVE:To review the research progress in peripheral nerve repair using col agen/silk fibroin nerve conduits. METHODS:In this paper, the first author retrieved the PubMed and CNKI from 2003 to 2016 to search articles regarding methods of constructing artificial nerve scaffolds and selection of raw materials. Data from these articles were col ected, summarized and analyzed. RESULTS AND CONCLUSION:Forty-six articles were included for final analysis. Col agen and its degradation products trigger no inflammatory response in the host because of high biocompatibility and biodegradability. However, its use is largely limited by its rapid degradation and poor physical performance. Silk fibroin has a high flexibility and biocompatibility, and exhibits a slow degradation in vivo. As a rapid prototyping technique, three-dimensional printing can print various forms of scaffolds within a short time, characterized as high-quality pore structure and large-scale production. Given these, the col agen/silk fibroin nerve conduit prepared using the three-dimensional printing technology can maintain the biocompatibility and even improve the mechanical properties of the raw materials. Until now, more investigations on nerve repair using col agen or silk fibroin have been done, and we have never stopped improving the production process of these scaffolds. Therefore, the col agen/silk fibroin scaffold prepared using the three-dimensional printing technology is expected to become the main candidate for the repair of peripheral nerve defects.

BACKGROUND:The traditional method of preparing tissue-engineered conduit has the defects of complex shape manufacturing and uncontrolable inner space structure, which cannot meet the requirements of some micro-catheters.
OBJECTIVE:To prepare a bionic spinal catheter and analyze its performance.
METHODS:The data model of the conduit was established using Solid Works software, and platform scan path was generated onthree-dimensionalprinter to produce the bionic spinal catheter with fibroin and colagen as raw materials. Then the water absorption, porosity, mechanical properties and celular compatibility of the conduits were detected. Next, the conduits were implanted into the subcutaneous tissue of rats and taken out at 1, 2, 3 and 4 weeks after surgery, respectively, to observe the degradation.
RESULTS AND CONCLUSION:The porosity of the conduit was (53.6±1.0)%, the water absorption was (1347±19.4)%, and the compression modulus was (0.60±0.12) MPa. The micropores distributed uniformly with different size ranging from 10 to 240 μm. Spherical or fusiform stem cels survived in the pores and densely adhered to the conduit with pseudopodia. The degradation rate ofthe conduit was 20%, 59%, 74%and 100% at 1, 2, 3 and 4 weeks after surgery, respectively. These findings indicate that the artificial bionic spinal catheter has good biocompatibility and degradability.

Stromal interaction molecule 1 (STIM1) is a key component mediating store-operated calcium entry (SOCE), which controls the opening and closing of plasma membrane Ca 2+ channels by sensing the Ca 2+ content of endoplasmic reticulum luminal stores, and thus affects the processes of cell adhesion, migration, gene expression and proliferation. Studies have shown that STIM1 is abnormally expressed in a variety of cells such as neurons, endothelial cells and platelets during ischemic stroke (IS) development; it plays an important role in the pathological processes regulating hypertension, promoting thrombosis, activating cellular autophagy, mediating apoptosis and promoting neuroinflammation. This review summarizes the research progress of STIM1 in the development and prognostic assessment of IS, and seeks to provide theoretical references for potential therapeutic targets for IS.

Objective:To explore the effect of online and offline blended scenario simulation teaching in the practice of nursing undergraduates.Methods:From August 2020 to May 2021, convenience sampling was used to select 76 nursing undergraduates in the class of 2017 who practiced in the Cardiology Department of the Second Affiliated Hospital of Harbin Medical University as the research object. The undergraduates were randomly divided into the experimental group and the control group, 38 in each group. The control group received the traditional graduation practice training, and the experimental group received online and offline blended scenario simulation teaching on this basis. After the practice, the clinical thinking ability of the two groups of students was evaluated by the Clinical Thinking Ability Evaluation Scale, the clinical practice ability of the two groups of students was evaluated by the Objective Structured Clinical Examination (OSCE) , and a teaching satisfaction survey was conducted.Results:The total score of clinical thinking ability, critical thinking ability, systematic thinking ability, evidence-based thinking ability, OSCE total score of the students in the experimental group were higher than those in the control group, and the differences were statistically significant ( P<0.05) . The students in the experimental group thought that the teaching method was helpful for in-depth understanding and application of theoretical knowledge, improving nursing assessment skills, clinical coping skills and communication skills, and at the same time helping to cultivate critical thinking and teamwork awareness, and arouse learning enthusiasm, and the differences were statistically significant (all P<0.05) . Conclusions:The online and offline blended scenario simulation teaching can effectively improve the clinical thinking ability, clinical practice ability and teaching satisfaction of nursing undergraduates, and it has good effect in the graduation practice of undergraduate nursing students.

Objective To observe the value of anatomical characteristics of femoral intercondylar notch of knee joint for predicting non-contact anterior cruciate ligament tear(NC-ACLT).Methods MRI data of knee joint of 55 patients with NC-ACLT(NC-ACLT group)and 55 controls(control group)were retrospectively analyzed.The parameters of intercondylar notch,including depth,width,depth/width ratio,opening width,opening width index,area and width of the femoral condyle's outer edge at the same level were measured between groups,and the types of intercondylar notch(type A,U and W)were recorded.Univariate and multivariate logistic regression analysis were used to screen the independent impact factors of NC-ACLT.Receiver operating characteristic curves were drawn,and the area under the curves(AUC)were calculated to evaluate the efficacy of each intercondylar notch parameter for predicting NC-ACLT.Results The depth and depth/width ratio of intercondylar notch in NC-ACLT group were both higher,while the opening width and opening width index of intercondylar notch in NC-ACLT group were both lower than those in control group(all P＜0.05).Multivariate logistic regression analysis revealed that the depth of intercondylar notch was an independent impact factors of NC-ACLT(P＜0.05).Taken 29.55 mm in depth of intercondylar notch,1.45 in depth/width ratio of intercondylar notch,21.15 mm in opening width of intercondylar notch and 0.29 in opening width index as the optimal cut-off value,respectively,the sensitivity of the above parameters for predicting NC-ACLT was 74.55％,58.18％,67.27％and 67.27％,the specificity was 69.09％,80.00％,61.82％and 78.18％,and the AUC was 0.720,0.713,0.652 and 0.710,respectively.Conclusion The anatomical characteristics of femoral intercondylar notch of knee joint could be used to predict NC-ACLT.The depth,depth/width ratio,opening width and opening width index of intercondylar notch could be used as predictive indicators.

Objective:To investigate the status and the influencing factors of influenza vaccination during the COVID-19 pandemic among community-dwelling elderly in Shanghai.Methods:A questionnaire survey on influenza vaccination among community-dwelling elderly was conducted in Shanghai Taikang elderly community in November 2020. The information on demographic characteristics, reasons for refusal of vaccination, and measures for increasing vaccination rates were collected. Multiple logistic regression was used to analyze the correlation between influenza vaccination and sociodemographic and health-related characteristics.Results:Among 520 respondents, the vaccination rate was 30.58% (159/520). Compared with unvaccinated group, elderly in vaccinated group was older ( t=16.04, P=0.003)and more educated(χ2=8.16, P=0.043). The elderly with comorbid heart disease, chronic obstructive pulmonary disease, tumor, asthma, Parkinson′s disease were likely to have vaccination ( OR=1.45, 2.16, 1.23, 1.64, 5.83; all P<0.05).The reasons for the elderly not to be vaccinated were concerns of side effects (46.26%, 167/361), lack of doctors′ recommendations (24.10%, 87/361), and unnecessary for people with good health conditions (19.39%, 70/361). The independent factors of influenza vaccine awareness rate were healthcare providers′ recommendations ( OR=9.18, 95% CI:5.47-16.32), vaccination at home( OR=11.79, 95% CI:6.87-21.66),vaccination available in community( OR=8.08, 95% CI:8.08-15.45),the mandatory requirement ( OR=4.61,95% CI:4.61-10.11),free of charge( OR=7.48, 95% CI:4.08-15.12). Conclusion:Influenza vaccination coverage among the elderly in Shanghai is still low even during the COVID-19 pandemic. Policy interventions, awareness education and strengthening the primary healthcare resources may contribute to achieving a high influenza vaccine coverage rate in the community-dwelling elderly

Objective:To investigate the preoperative ascending aorta diameter in patients with acute type A aortic dissection in the Chinese population, compares and analyze the differences in preoperative blood biomarkers, and evaluate the impact of the preoperative ascending aorta diameter in this part of patients on the short-term prognosis of patients.Methods:A collection of 641 patients with acute type A aortic dissection who were enrolled in the " Acute Aortic Syndrome High-Risk Early Warning and Intervention Study" project from January 2018 to January 2020 were collected. Divide the patients into two groups (group Ⅰ<55 mm, group Ⅱ≥55 mm) according to the preventive intervention value of ascending aorta diameter recommended by the guideline for studying preoperative ascending aorta diameter difference in blood biomarkers and the influence of ascending aorta diameter on the short-term prognosis of patients. All patients had CT scans to assess the diameter of the ascending aorta before operation.Results:In this study, all patients with acute type A aortic dissection had a mean preoperative ascending aorta diameter of (46.9±9.7)mm. The preoperative ascending aorta diameter of all patients was less than 55 mm, accounted for 84.1%. Male patients were more likely to have aortic dissection than females; most patients' age was less than 60 years old. The preoperative blood inflammatory index counts were higher in the ascending aorta diameter ≥55 mm group. However, the long-term prognosis of patients with different ascending aorta diameters before surgery was not apparent in this study. The preoperative survival rate and short-term survival rate of patients with ascending aorta diameter <55 mm were higher than those of other groups, but the difference was not statistically significant.Conclusion:In patients with acute type A aortic dissection, the diameter of the ascending aorta is usually less than 55 mm. Moreover, the blood inflammatory index counts are high in the preoperative ascending aorta diameter ≥55 mm group. Meanwhile, patients with smaller ascending aorta diameter have better survival rate and short-term prognosis.

The development of new proton-pump inhibitors (PPIs) with less adverse effects by lowering the pKa values of nitrogen atoms in pyrimidine rings has been previously suggested by our group. In this work, we proposed that new PPIs should have the following features: (1) number of ring II = number of ring I + 1; (2) preferably five, six, or seven-membered heteroatomic ring for stability; and (3) 1 < pKa1 < 4. Six molecular scaffolds based on the aforementioned criteria were constructed, and R groups were extracted from compounds in extensive data sources. A virtual molecule dataset was established, and the pKa values of specific atoms on the molecules in the dataset were calculated to select the molecules with required pKa values. Drug-likeness screening was further conducted to obtain the candidates that significantly reduced the adverse effects of long-term PPI use. This study provided insights and tools for designing targeted molecules in silico that are suitable for practical applications.
Computer Simulation ; Drug Design ; Humans ; Proton Pump Inhibitors ; toxicity ; Toxicological Phenomena