Objective The study aims to investigate the immunological functions of the nucleocapsid (N) protein of the novel coronavirus Omicron (BA.1, BA.2) and evaluate the differences among different N proteins of mutant strains in immunogenicity. Methods By aligning sequences, the mutation sites of the Omicron (BA.1, BA.2) N protein relative to prototype strain of the novel coronavirus (Wuhan-Hu-1) were determined. The pET-28a-N-Wuhan-Hu-1 plasmid was used as template to construct pET-28a-BA.1/BA.2-N through single point mutation or homologous recombination. The three kinds of N protein were expressed in prokaryotic system, purified through Ni-NTA affinity chromatography, and then immunized into mice. The titer and reactivity of the polyclonal antibody, as well as the expression level of IL-1β and IFN-γ in mouse spleen cells, were detected using indirect ELISA and Western blot assay. Results The constructed prokaryotic expression plasmids were successfully used to express the Wuhan-Hu-1 N, BA.1 N, and BA.2 N proteins in E.coli BL21(DE3) at 37 DegreesCelsius for 4 hours. The indirect ELISA test showed that the titers of polyclonal antibody prepared by three N proteins were all 1:51 200. All three N proteins can increase the expression of IFN-γ and IL-1β cytokines, but the effect of Omicron N protein in activing two cytokines was more obvious than that of Wuhan-Hu-1 N protein. Conclusion The study obtained three new coronavirus N proteins and polyclonal antibodies, and confirmed that mutations in the amino acid sites of the N protein can affect its immunogenicity. This provides a basis for developing rapid diagnostic methods targeting N protein of different novel coronavirus variants.
Animals ; Mice ; SARS-CoV-2/genetics* ; Coronavirus Nucleocapsid Proteins/immunology* ; Nucleocapsid Proteins/isolation & purification* ; COVID-19/immunology* ; Antibodies, Viral/immunology* ; Mice, Inbred BALB C ; Interferon-gamma/metabolism* ; Interleukin-1beta/metabolism* ; Female ; Escherichia coli/metabolism* ; Mutation ; Humans

Yarrowia lipolytica is a non-conventional yeast with unique physiological and metabolic characteristics. It is suitable for production of various products due to its natural ability to utilize a variety of inexpensive carbon sources, excellent tolerance to low pH, and strong ability to secrete metabolites. Currently, Y. lipolytica has been demonstrated to produce a wide range of carboxylic acids with high efficiency. This article summarized the progress in engineering Y. lipolytica to produce various carboxylic acids by using metabolic engineering and synthetic biology approaches. The current bottlenecks and solutions for high-level production of carboxylic acids by engineered Y. lipolytica were also discussed, with the aim to provide useful information for relevant studies in this field.
Carboxylic Acids/metabolism* ; Metabolic Engineering ; Synthetic Biology ; Yarrowia/metabolism*

Objective : To study root morphology, the incidence of three root canals and the root canal anatomy of maxillary premolars. Methods: The cone-beam computed tomography (CBCT) data of 779 maxillary first premolars and 728 maxillary second premolars were collected from 412 patients in Zhuhai Stomatological Hospital. The root and canal morphology, incidence of three canals, bilateral symmetry and location of root canal bifurcation were analyzed. Results : The incidence of three canals in the maxillary first premolars was 1.8% and that in the maxillary second premolars was 0.3%. The incidence of three canals in the maxillary first premolars was significantly higher than that in the maxillary second premolars (c2=8.304, P=0.004). The symmetrical ratio of the three-canal maxillary first premolar was 27.3%. There was no symmetrical three-canal maxillary second premolar. The anatomical morphology of the maxillary premolar can be single root, double root or trident root. Its internal root canal system is complex and diverse. There are seven kinds of Vertucci morphology: the first maxillary premolar is mainly Vertucci IV type, and the second maxillary premolar is mainly Vertucci I type. Most of the root canal bifurcations of the three-canal maxillary premolars were observed in the midthird or the cervical third of the root. All three-canal maxillary premolars had three independent apical foramens. Conclusion The root canal morphology of maxillary premolars is complex and changeable. CBCT plays an important role in the discovery of variation and extra root canals.

Objective To investigate the effects,difficult points and technical key points of the interventional embolization in brain micro-aneurysms.Methods Retrospectively analyzed the material of the interventional embolization in 38 patients with brain micro-aneurysm.Results Twenty-six cases were treated with simple spring coil embolization technology,4 cases were treated with double micro-catheter embolization technic,2 cases were treated with embolization combining ballon assistive technic and 6 cases were treated with embolization combining stent assistive technic.All the 38 patients successfully embolized.The postoperative immediate cerebral angiogram to determine the degree of embolization:12 cases were 0 level,21 cases were 1 level and 5 cases were 2 level.The Rankin grade results showed that 0-1 score in 24 cases,2 scores in 10 cases,3-4 scores in 2 cases and 5 scores in 2 cases.Thirty-three patients were followed up for 6-12 months.No aneurysms recurred or re-raptured.Conclusions The spring coil embolization of brain micro-aneurysms is a feasible,safe and effective method,though the technics involved is difficulty.Selecting suitable embolization technics according to the characteristic of each micro-aneurysm can reduce the risk of operation,decrease complications and increase the successful rate.

Objective To explore the mechanism of self-awareness in the heavy smokers(HS)by using regional homogeneity(ReHo)combined with resting-state functional MRI(fMRI).Methods Thirty HS and 31 healthy non-smokers(NS)matched for age and sex underwent a 3.0 T resting-state fMRI.The data were post-processed by SPM 5 and then the ReHo values were calculated by REST software.The ReHo values between the two groups were compared by two-sample t-test.The brain map with significant difference of ReHo value was obtained.Results Compared with that in NS group,the regions with decreased ReHo value included the bilateral precuneus,superior frontal gyrus,medial prefrontal cortex,right angular gyrus,inferior frontal gyrus,inferior occipital gyrus,cerebellum,and left middle frontal gyrus in HS group.The regions of increased ReHo value included the bilateral insula,parahippocampal gyrus,white matter of parietal lobe,pons,left inferior parietal lobule,lingual gyrus,thalamus,inferior orbital gyrus,white matter of temporal-frontal lobe,and cerebellum.The difference was more obvious in the left hemisphere.Conclusions In HS,abnormal ReHo on a resting state which reflects network of smoking addiction.This method may be helpful in understanding the mechanism of self-awareness in HS.