Preparation and immunogenicity evaluation of mRNA vaccine against porcine epidemic diarrhea / 生物工程学报

Porcine epidemic diarrhea (PED) is a highly contagious disease that causes high mortality in suckling piglets. Although several licensed inactivated and live attenuated vaccines were widely used, the infection rate remains high due to unsatisfactory protective efficacy. In this study, mRNA vaccine candidates against PED were prepared, and their immunogenicity was evaluated in mice and pregnant sows. The mRNA PED vaccine based on heterodimer of viral receptor binding region (RBD) showed good immunogenicity. It elicited robust humoral and cellular immune responses in mice, and the neutralizing antibody titer reached 1:300 after a single vaccination. Furthermore, it induced neutralizing antibody level similar to that of the inactivated vaccine in pregnant sows. This study developed a new design of PED vaccine based on the mRNA-RBD strategy and demonstrated the potential for clinical application.

Quantifying carotid stiffness in a pre-hypertensive population with ultrafast ultrasound imaging

Purpose@#The aim of this study was to assess carotid stiffening in a pre-hypertensive (PHT) population using ultrafast pulse wave velocity (ufPWV). @*Methods@#This study retrospectively enrolled 626 individuals who underwent clinical interviews, serum tests, and assessments of the systolic blood pressure (SBP), diastolic blood pressure (DBP), carotid intima-media thickness (cIMT), pulse wave velocity-beginning of systole (PWV-BS), and pulse wave velocity-end of systole (PWV-ES) between January 2017 and December 2021. The patients were divided into three groups according to their blood pressure (BP)—normal BP (NBP): SBP 0.05). However, the NBP group had a notably lower PWV-ES than the PHT (P0.05). @*Conclusion@#Carotid morphological and biomechanical properties in the PHT group differed from those in the NBP group. ufPWV could be used for an early evaluation of carotid stiffening linked to pre-hypertension.

Comparison of invasive and non-invasive blood pressure in perioperative elderly hypertensive patients with atherosclerosis of the extremities / 中华老年医学杂志

Objective:To compare the correlation and differences between invasive blood pressure(IBP)and noninvasive blood pressure(NBP)monitoring at three different levels of systolic blood pressure(SBP), diastolic blood pressure(DBP)and mean arterial pressure(MAP)in elderly hypertensive patients with atherosclerosis of the extremities during perioperative anesthesia.Methods:156 elderly patients were prospectively admitted to the Department of Vascular Surgery, Beijing Anzhen Hospital, Capital Medical University, for peripheral vascular stenosis interventions between December 2018 and December 2021.Their IBP and NBP were measured simultaneously during the perioperative anesthesia period.Then the correlation and consistency between IBP and NBP were analyzed via the Pearson correlation coefficient, Bland-Altman plots, and the receiver operating characteristic curve(ROC curve).Results:A total of 156 elderly patients were enrolled, including 108 men(69.2%)and 48 women(30.8%), with a mean age of 72.2±7.6.Pearson correlation analysis revealed that there was a significant positive correlation between IBP and NBP.The correlation coefficient was 0.993 for invasive systolic blood pressure(ISBP)and non-invasive systolic blood pressure(NSBP), 0.808 for invasive diastolic blood pressure(IDBP)and non-invasive diastolic blood pressure(NDBP), and 0.853 for invasive mean arterial pressure(IMAP)and non-invasive mean arterial pressure(NMAP)( P<0.001 for all). Bland-Altman analysis showed that the mean deviation of ISBP and NSBP was(20.3±6.5)mmHg(95% CI: 19.18-21.38)(1 mmHg=0.133 kPa), the mean deviation of IDBP and NDBP was(3.8±9.7)mmHg(95% CI: 2.13-5.41), and the mean deviation of IMAP and NMAP was(12.7±11.0)mmHg(95% CI: 10.83-14.55). The correlation coefficient of ISBP-NSBP deviation with ISBP was 0.856, the correlation coefficient of IDBP-NDBP deviation with IDBP was 0.206, and the correlation coefficient of IMAP-NMAP deviation with IMAP was 0.583( P<0.05 for all). When ISBP≥137 mmHg, the sensitivity of an ISBP-NSBP deviation ≥20 mmHg was 96.3%, the specificity was 96.4%, and the area under the ROC curve was 0.970(95% CI: 0.934-1.000). When ISBP≥158 mmHg, the sensitivity and specificity of a predicted ISBP-NSBP deviation≥25 mmHg were 97.4% and 78.8%, respectively, and the area under the ROC curve was 0.876(95% CI: 0.820-0.933); When ISBP≥208 mmHg, the sensitivity and specificity of a predicted ISBP-NSBP deviation≥30 mmHg were 100% and 98.5%, respectively, and the area under the ROC curve was 0.985(95% CI: 0.964-1.000). Conclusions:There is a good agreement between IBP and NBP in elderly hypertensive patients with peripheral atherosclerosis during perioperative anesthesia.The magnitude of the deviation between the two is significantly and positively correlated with the level of blood pressure, suggesting that we should appropriately choose the method of blood pressure measurement in the perioperative period to correctly evaluate the blood pressure of these elderly patients.

Berberine targets the electron transport chain complex I and reveals the landscape of OXPHOS dependency in acute myeloid leukemia with IDH1 mutation / 中国天然药物

Metabolic reprogramming, a newly recognized trait of tumor biology, is an intensively studied prospect for oncology medicines. For numerous tumors and cancer cell subpopulations, oxidative phosphorylation (OXPHOS) is essential for their biosynthetic and bioenergetic functions. Cancer cells with mutations in isocitrate dehydrogenase 1 (IDH1) exhibit differentiation arrest, epigenetic and transcriptional reprogramming, and sensitivity to mitochondrial OXPHOS inhibitors. In this study, we report that berberine, which is widely used in China to treat intestinal infections, acted solely at the mitochondrial electron transport chain (ETC) complex I, and that its association with IDH1 mutant inhibitor (IDH1mi) AG-120 decreased mitochondrial activity and enhanced antileukemic effect in vitro andin vivo. Our study gives a scientific rationale for the therapy of IDH1 mutant acute myeloid leukemia (AML) patients using combinatory mitochondrial targeted medicines, particularly those who are resistant to or relapsing from IDH1mi.

Adult dental epithelial stem cell-derived organoids deposit hydroxylapatite biomineral / 国际口腔科学杂志·英文版

Ameloblasts are specialized cells derived from the dental epithelium that produce enamel, a hierarchically structured tissue comprised of highly elongated hydroxylapatite (OHAp) crystallites. The unique function of the epithelial cells synthesizing crystallites and assembling them in a mechanically robust structure is not fully elucidated yet, partly due to limitations with in vitro experimental models. Herein, we demonstrate the ability to generate mineralizing dental epithelial organoids (DEOs) from adult dental epithelial stem cells (aDESCs) isolated from mouse incisor tissues. DEOs expressed ameloblast markers, could be maintained for more than five months (11 passages) in vitro in media containing modulators of Wnt, Egf, Bmp, Fgf and Notch signaling pathways, and were amenable to cryostorage. When transplanted underneath murine kidney capsules, organoids produced OHAp crystallites similar in composition, size, and shape to mineralized dental tissues, including some enamel-like elongated crystals. DEOs are thus a powerful in vitro model to study mineralization process by dental epithelium, which can pave the way to understanding amelogenesis and developing regenerative therapy of enamel.

Eukaryotic expression of GP5 and M protein of porcine reproductive and respiratory syndrome virus and immunogenicity evaluation / 生物工程学报

In order to understand the prevalence and evolution of porcine reproductive and respiratory syndrome virus (PRRSV) in China and to develop subunit vaccine against the epidemic lineage, the genetic evolution analysis of PRRSV strains isolated in China from 2001 to 2021 was performed. The representative strains of the dominant epidemic lineage were selected to optimize the membrane protein GP5 and M nucleotide sequences, which were used, with the interferon and the Fc region of immunoglobulin, to construct the eukaryotic expression plasmids pCDNA3.4-IFNα-GP5-Fc and pCDNA3.4-IFNα-M-Fc. Subsequently, the recombinant proteins IFNα-GP5-Fc and IFNα-M-Fc were expressed by HEK293T eukaryotic expression system. The two recombinant proteins were mixed with ISA206VG adjuvant to immunize weaned piglets. The humoral immunity level was evaluated by ELISA and neutralization test, and the cellular immunity level was detected by ELISPOT test. The results showed that the NADC30-like lineage was the main epidemic lineage in China in recent years, and the combination of IFNα-GP5-Fc and IFNα-M-Fc could induce high levels of antibody and cellular immunity in piglets. This study may facilitate the preparation of a safer and more effective new PRRSV subunit vaccine.

The I226R protein of African swine fever virus inhibits the cGAS-STING-mediated innate immune response / 生物工程学报

This study aimed to explore the mechanism of how African swine fever virus (ASFV) I226R protein inhibits the cGAS-STING signaling pathway. We observed that I226R protein (pI226R) significantly inhibited the cGAS-STING-mediated type Ⅰ interferons and the interferon-stimulated genes production by dual-luciferase reporter assay system and real-time quantitative PCR. The results of co-immunoprecipitation assay and confocal microscopy showed that pI226R interacted with cGAS. Furthermore, pI226R promoted cGAS degradation through autophagy-lysosome pathway. Moreover, we found that pI226R decreased the binding of cGAS to E3 ligase tripartite motif protein 56 (TRIM56), resulting in the weakened monoubiquitination of cGAS, thus inhibiting the activation of cGAS and cGAS-STING signaling. In conclusion, ASFV pI226R suppresses the antiviral innate immune response by antagonizing cGAS, which contributes to an in-depth understanding of the immune escape mechanism of ASFV and provides a theoretical basis for the development of vaccines.

Effect of C-KIT gene mutation on the prognosis of acute myeloid leukemia associated with core-binding factor in children: a Meta-analysis / 白血病·淋巴瘤

Objective:To systematically evaluate the relationship between C-KIT gene mutation and the prognosis of childhood core-binding factor-related acute myeloid leukemia (CBF-AML).Methods:The PubMed database was searched with "KIT" "Acute Myeloid Leukemia" and "Children"; the Chinese Journal Full-text Database (CNKI), Chinese Biomedical Literature Database (CBM), VIP database and Wanfang database were also searched with "KIT" "Acute Myeloid Leukemia" and "Children", and the search time was from the establishment of the database to October 1, 2020. After strict screening, the literature was included in the analysis; according to the presence or absence of genetic changes, the included cases was divided into C-KIT mutation group and wild group, and the complete remission (CR) rate, event-free survival (EFS) rate, and overall survival (OS) rate of the two groups were analyzed.Results:Six articles were collected, including 4 articles in English and 2 articles in Chinese, with a total of 667 patients. There was a statistically significant difference in the EFS rate between the C-KIT mutation group and wild group in children with CBF-AML ( HR = 2.40, 95% CI 1.47-3.89, P = 0.001); there was no significant difference in the CR rate and OS rate ( OR = 0.93, 95% CI 0.48-1.80, P = 0.830; HR = 1.92, 95% CI 0.96-3.83, P = 0.065) between the two groups. Conclusions:C-KIT gene mutation may be a risk factor for poor prognosis in children with CBF-AML.

Analysis of gene mutation type and frequency in children with thalassemia aged 0-18 years in Chengdu, Sichuan / 中华检验医学杂志

Objective:To analyze the type and frequency of thalassemia gene mutation in children aged 0 to 18 years in Chengdu.Methods:A total of 568 children from Chengdu, who were initially positive for thalassemia during screening from September 2018 to July 2021, were recruited. Among them, there were 308 males and 260 females. The type of mutation and distribution of α and β types of thalassemia in this cohort was analyzed utilizing PCR reverse dot blot.Results:Among the 568 children, 356 were genetically diagnosed as thalassemia, with a total positive rate of 62.68%. Among them, there were 140 cases of α-thalassemia with a positive rate of 24.65%, and 202 cases of β-thalassemia with a positive rate of 35.56%. There were 14 carriers of α-complex β-thalassemia gene, and the positive rate was 2.46%. Among these cases, the types of α-thalassemia gene mutation were mainly αα/--sea (79.29%), αα/-α3.7 (7.86%), and-α3.7/--sea (7.14%) genotypes, accounting for 94.29% of all types. In the 202 β-thalassemia patients, 199 heterozygous mutations were identified, mainly including cd17(A?T) (36.13%), cd41-42(-TCTT) (32.68%), IVS-2-654(C?T) (20.79%), and accounting for 88.61% of all types of gene mutation, and 3 compound heterozygous mutations were detected. α-complex β-thalassemia was detected in 14 patients, including cd41-42(-TCTT)/-α3.7, VS-2-654(C?T)/--sea, cd17(A?T)/-α3.7 and cd41-42(-TCTT)/--sea, which accounting for 57.14% of all types of gene mutation. Our results showed that there is no sex difference between α and β thalassemia in Chengdu area, whereas the prevalence of α combined with β thalassemia is higher in males ( P=0.003). Conclusions:The type of α-thalassemia mutation in Chengdu is mainly αα/--sea, whereas β-thalassemia with cd17 (A?T) mutations and α-complex β-thalassemia are more frequent in males. This study provides a reference for the formulation of prevention and control strategies for thalassemia in Chengdu.

Effect of overexpressed zinc finger protein 580 on apoptosis of oxygen-glucose deprivation SH-SY5Y cells and its possible mechanism / 中华围产医学杂志

Objective:To investigate the expression of zinc finger protein 580 (ZNF580) in oxygen-glucose deprivation (OGD) model of SH-SY5Y cell line and its overexpression on the apoptosis of hypoxic-ischemic neurons and the possible mechanism.Methods:The study was divided into two parts: (1) Human neuroblastoma SH-SY5Y cell line was cultured and divided into the model group and control group. The model group was incubated at 37 ℃ for 6 h in a three-gas incubator of 95% N 2, 5% CO 2, and 0.1% O 2 to establish OGD model, and proteins were extracted at 6, 12, and 24 h after OGD. The expression of ZNF580 was quantified by Western blot. (2) Effects of ZNF580 overexpressed with lentivirus transfection on the apoptosis and cleaved caspase-3 expression: Cells were collected from the control group and model group 24 h after OGD. Overexpressed ZNF580 cells were constructed by lentivirus transfection as the overexpression group and then treated with OGD. Flow cytometry was used to detect the apoptosis rate in the three groups and Western blot was used to detect the expression of cleaved caspase-3. Two independent sample t-test, one-way variance analysis, and LSD- t for pairwise comparison were used for statistical analysis. Results:(1) ZNF580 expression was significantly increased at 6, 12, and 24 h after OGD compared with the control group (1.36±0.05, 2.12±0.07, 1.69±0.05 vs 1.00, LSD- t=9.20, 28.26, and 19.21, all P<0.001). (2) Apoptosis rates of the control, model, and overexpression groups were (1.07±0.56)%, (21.51±1.65)%, and (3.42±0.93)%, respectively, and relative expression levels of cleaved caspase-3 were 1.00, 2.47±0.59, and 1.70±0.25, respectively. Compared with the control group, apoptosis rate and cleaved caspase-3 relative expression level were significantly increased in the model group (LSD- t=21.98 and 8.17, both P=0.001), while the two figures were significantly decreased in the overexpression group when compared with the model group (LSD- t=19.45, P=0.001; LSD- t=4.28, P=0.005). Conclusion:Hypoxia and ischemia could lead to the overexpression of ZNF580, which may reduce the apoptosis of hypoxic-ischemic neurons by inhibiting the expression of cleaved caspase-3 and affecting its enzymatic activation.

Effects of low-dose Esketamine on respiration, circulation and pain in elderly patients undergoing surgical treatment for iliac artery stenosis / 中华老年医学杂志

Objective:To examine the effects of low-dose Esketamine on circulatory function, respiratory function and pain in elderly patients undergoing peripheral vascular interventions, and to provide evidence for appropriate and safe use of Esketamine in elderly patients under anesthesia.Methods:Forty elderly patients with iliac artery stenosis at Beijing Anzhen Hospital affiliated to the Capital Medical University were enrolled and treated with balloon percutaneous transluminal angioplasty(PTA)and stent implantation on a selective basis.Among them, 33 were male and 7 were female with American Society of Anesthesiologists(ASA)physical classification of Ⅱ-Ⅲ.The patients were randomly divided into two groups(20 in each group)using the randomized number method, with the control group(Group C)given 2 ml normal saline intravenously and the Esketamine group(Group L)given Esketamine 0.25 mg/kg intravenously(slow intravenous administration within 1 min). Values of arterial blood pressure and heart rate in stabilized condition in the operating room were collected as the baseline(T0). Five minutes before the surgeon dilated the stenosed iliac artery, intravenous anesthetics were given in both groups as required for the trial.The first 5 minutes before dilatation of the stenosed iliac artery was used as T1, the first 4 minutes as T2, and the first 3 minutes as T3.The recording continued until the 25th minute after anesthetic administration as T30, with a collection of 25-minute blood pressure and heart rate values for analysis.Blood gas analysis was made for arterial blood samples drawn at the time patients entered the operating room(M1), 5 minutes after drug administration(M2), and 10 minutes after drug administration(M3). For all patients, the pain level was recorded using a self-reported scale while the iliac artery was dilated.The doses of vasoactive drugs were recorded from the beginning of the dilatation of the iliac artery to the end of the procedure in patients.Results:In Group C, PaO 2 at M2 was elevated compared with at M1( P=0.003); In Group L, PaCO 2 at M2 was elevated compared with at M1( P=0.011). At T4, systolic blood pressure and diastolic blood pressure were elevated in Group L compared with Group C, and the differences were statistically significant( t=2.403, 2.119, all P<0.05); At T3, heart rate was elevated in Group L compared with Group C, with a statistically significant difference( t=0.789, P=0.007); Compared with Group C, systolic blood pressure was lower in Group L from T6 to T15, with statistically significant differences( t=3.143, 2.403, 2.272, 3.460, 2.610, 2.568, 2.453, 2.367, 2.282, and 2.187, all P<0.05). Diastolic blood pressure was lower in Group L from T8 to T16, with statistically significant differences( t=3.880, 6.602, 2.967, 3.243, 2.641, 3.253, 3.114, 4.521, and 2.659, all P<0.05), and from T7 to T13, the heart rate was lower in Group L, and the differences were statistically significant( t=2.246, 3.285, 3.207, 2.752, 2.725, 2.713, and 2.473, all P<0.05). Compared with Group C, the incidence of dilatation pain in patients with iliac artery stenosis in Group L was lower, and the difference was statistically significant( χ2=6.140, P=0.030). Doses of vasoactive drugs in both groups, including raceanisodamine hydrochloride, norepinephrine, esmolol, and nicardipine, were lower in Group L, and the differences were statistically significant( t=3.573, 7.883, 3.889, and 6.665, P=0.039, 0.001, 0.046, and 0.006). Conclusions:Low-dose Esketamine causes mild respiratory depression and low circulatory excitation in elderly patients with iliac artery stenosis undergoing PTA, and also reduces painful irritation during blood vessel dilatation in elderly patients.

Carotid stiffening predicts cardiovascular risk stratification in mid-life: non-invasive quantification with ultrafast ultrasound imaging

Purpose@#The present study investigated the association between Systematic COronary Risk Evaluation (SCORE)-estimated cardiovascular risk and carotid stiffening in a middle-aged population using ultrafast pulse wave velocity (ufPWV). @*Methods@#This study enrolled 683 participants without known cardiovascular disease or diabetes mellitus who underwent ufPWV measurements. Clinical interviews, physical examinations, laboratory findings, carotid intima-media thickness (cIMT), pulse wave velocity (PWV) at the beginning of systole (PWV-BS), and PWV at the end of systole (PWV-ES) were assessed. Each participant underwent an assessment of SCORE risk based on major cardiovascular risk factors (CVRFs), including age, sex, smoking, systolic blood pressure (SBP), and total cholesterol (TC). Crude and adjusted odds ratios (ORs) with 95% confidence intervals and ordinal logistic regression were used. Overall CVRFs were adjusted to assess ORs. @*Results@#cIMT and carotid stiffening in PWV-BS and PWV-ES were significantly different between sex subgroups (all P0.05). @*Conclusion@#Carotid stiffening quantified by ufPWV is linked to SCORE categories, and elevated PWV-ES may aid in cardiovascular risk stratification.

The quality of life and its influencing factors in high risk population of stroke in district / 中华行为医学与脑科学杂志

Objective:To understand the quality of life of high risk population of stroke in community and analyze the influencing factors.Methods:Four community health service centers in Huangpu District were randomly selected, and the subjects were included by using convenient sampling method among the high risk groups of stroke found in the community stroke screening and prevention and control project in Shanghai.The World Health Organization quality of life scale-brief form questionnaire(WHOQOL-BREF), self-rating depression scale (SDS) and self-rating anxiety scale (SAS) were used as the survey tools to study 1200 high-risk stroke subjects.Single sample t-test was used to compare the differences between the scores and the data of 24 centers in the world, and multiple linear stepwise regression were used to analyze the influencing factors. Results:The scores of physical field, psychological field and social relationship field ((13.60±1.86), (14.58±1.97), (13.72±2.10)respectively) of high-risk population of stroke were lower than the scores of general population of 24 centers in the world ( P<0.01), and the scores of environmental field (14.08±1.95) were higher than it ( P<0.01), of which the differences were all statistically significant.The results of multiple linear stepwise regression analysis showed that old age, anxiety and depression were the risk factors influencing the scores of physical field( β=-0.027, -0.056, -0.051), psychological field( β=-0.019, -0.055, -0.050) and environmental field( β=-0.017, -0.040, -0.054); old age and depression were the risk factors influencing the scores of social relationship field( β=-0.026, -0.067); anxiety and depression were the risk factors influencing the self-assessment of quality of life and health ( β=-0.012, -0.014 for quality of life; -0.012, -0.014 for health, all P<0.01). Conclusion:The quality of life of high-risk population of stroke may be related to age, depression, anxiety and other psychological factors.The prevention and treatment of stroke should take both physical and mental measures, take timely intervention for poor psychological status, and gradually improve the quality of life.

Bone marrow microenvironment and differentiation of leukemia cells / 国际肿瘤学杂志

Bone marrow microenvironment (BMM) is the environment on which leukemia cells depend. It contains stem cells, bone marrow stromal cells, and abundant cytokines, which can regulate the differentiation and proliferation of leukemia cells. The regulation of BMM on the differentiation of leukemia cells is a complex process that can act on different targets and signaling pathways. It mainly includes hypoxia-inducible factor, integrins, Notch, and Wnt/β-catenin signal pathways. The study of relationship between BMM and leukemia cell differentiation can help to find pathways and targets that induce leukemia differentiation which will find new directions for the treatment of leukemia.

Application of stereotactic body radiotherapy in small hepatocellular carcinoma / 临床肝胆病杂志

At present, hepatic resection (HR) and radiofrequency ablation of (RFA) are the main radical treatment methods for small hepatocellular carcinoma (sHCC), while stereotactic body radiotherapy (SBRT) is developing rapidly and there is an increasing number of reports on the effective treatment of sHCC with SBRT. This article introduces the technical advantages, therapeutic dose, and fractionation scheme of SBRT in the treatment of sHCC, as well as the limit of normal liver tissue and the protection of surrounding organs at risk. This article also compares the efficacy of SBRT versus HR and RFA in the treatment of sHCC and briefly describes the adverse reactions of SBRT in the treatment of sHCC. Previous studies have shown that for some sHCC cases, SBRT has an equal or even better clinical effect than HR and RFA, with controllable toxicity. Therefore, SBRT is expected to become another radical treatment method for sHCC.

Methodological study on eliminating nucleic acid contamination in molecular diagnostic laboratory / 生物工程学报

Nucleic acid detection technique has good sensitivity and specificity and is widely used in in vitro diagnosis, animal and plant commodity quarantine, forensic identification, and other fields. However, it is susceptible to carryover contamination during the operation and leads to false-positive results, which seriously affects the detection accuracy. Therefore, finding an effective solution to prevent and eliminate nucleic acid carryover contamination has become particularly urgent. This study compared several different methods for removing nucleic acid contamination and confirmed that sodium hypochlorite solution and PCRguard reagent could effectively eliminate nucleic acid carryover in the liquid and on surfaces of different materials. Besides, the combination of sodium hypochlorite solution and PCRguard can solve the nucleic acid aerosol contamination. This study proposes solutions for the routine prevention of carryover contamination and removal of aerosol that has occurred in molecular diagnostic laboratories.

Numerical study on the effect of the geometry size of multi-chamber infusion bag on its bursting force / 生物医学工程学杂志

This study explored the variation of bursting force of multi-chamber infusion bag with different geometry size, providing guidance for its optimal design. Models of single-chamber infusion bag with different size were established. The finite element based on fluid cavity method was adopted to calculate the fluid-solid coupling deformation process of infusion bag to obtain corresponding critical bursting force. As a result, we proposed an empirical formula predicting the critical bursting force of one chamber infusion bag with specified geometry size. Besides, a theoretical analysis, which determines the force condition of three chamber infusion bag when falling from high altitude, was conducted. The proportion of force loaded on different chamber was gained. The results indicated that critical bursting force is positively related to the length and width of the chamber, and negatively related to the height of the chamber. While the infusion bag falling, the impact force loaded on each chamber is proportional to the total liquid within it. To raise the critical bursting force of in fusion bag, a greater length and width corresponding to reduced height are recommended considering the volume of liquid needed to be filled in.

Finite element method simulating bursting process of multi-chamber flexible package infusion bag / 生物医学工程学杂志

This study aims to overcome the shortcomings such as low efficiency, high cost and difficult to carry out multi-parameter research, which limited the optimization of infusion bag configuration and manufacture technique by experiment method. We put forward a fluid cavity based finite element method, and it could be used to simulate the stress distribution and deformation process of infusion bag under external load. In this paper, numerical models of infusion bag with different sizes was built, and the fluid-solid coupling deformation process was calculated using the fluid cavity method in software ABAQUS subject to the same boundary conditions with the burst test. The peeling strength which was obtained from the peeling adhesion test was used as failure criterion. The calculated resultant force which makes the computed peeling stress reach the peeling strength was compared with experiment data, and the stress distribution was analyzed compared with the rupture process of burst test. The results showed that considering the errors caused by the difference of weak welding and eccentric load, the flow cavity based finite element method can accurately model the stress distribution and deformation process of infusion bag. It could be useful for the optimization of multi chamber infusion bag configuration and manufacture technique, leading to cost reduction and study efficiency improvement.

Strategies for vaccine development of COVID-19 / 生物工程学报

An epidemic of acute respiratory syndrome in humans, which appeared in Wuhan, China in December 2019, was caused by a novel coronavirus (SARS-CoV-2). This disease was named as "Coronavirus Disease 2019" (COVID-19). SARS-CoV-2 was first identified as an etiological pathogen of COVID-19, belonging to the species of severe acute respiratory syndrome-related coronaviruses (SARSr-CoV). The speed of both the geographical transmission and the sudden increase in numbers of cases is much faster than SARS and Middle East respiratory syndrome (MERS). COVID-19 is the first global pandemic caused by a coronavirus, which outbreaks in 211 countries/territories/areas. The vaccine against COVID-19, regarded as an effective prophylactic strategy for control and prevention, is being developed in about 90 institutions worldwide. The experiences and lessons encountered in the previous SARS and MERS vaccine research can be used for reference in the development of COVID-19 vaccine. The present paper hopes to provide some insights for COVID-19 vaccines researchers.

Role of cyclophilin A during coronavirus replication and the antiviral activities of its inhibitors / 生物工程学报

Cyclophilin A (CypA) is a widely distributed and highly conserved protein in organisms. It has peptidyl-prolyl cis/trans isomerase activity and is a receptor for cyclosporin A (CsA). Coronaviruses are enveloped, single-stranded, positive-sense RNA viruses. Seven types of coronaviruses are currently known to infect humans, among which SARS-CoV, MERS-CoV, and SARS-CoV-2 are fatal for humans. It is well established that CypA is essential for the replication of various coronaviruses such as SARS-CoV, CoV-229E, CoV-NL63, and FCoV. Additionally, CsA and its derivatives (ALV, NIM811, etc.) have obvious inhibitory effects on a variety of coronaviruses. These results suggest that CypA is a potential antiviral target and the existing drug CsA might be used as an anti-coronavirus drug. At the end of 2019, SARS-CoV-2 raged in China, which seriously theatern human health and causes huge economic lases. In view of this, we describe the effects of CypA on the replication of coronaviruses and the antiviral activities of its inhibitors, which will provide the scientific basis and ideas for the development of antiviral drugs for SARS-CoV-2.