Objective To investigate the Rv2346c gene function through constructing Rv2346c gene knockout strains of Mycobacterium tuberculosis (M . tuberculosis) mediated by bacteriophage and observing its virulence after infecting mice lung tissue in vivo .Methods The affinal exchange sites (AES) of the target gene was built ,and then integrated into the phage genomes of M .tuberculosis for harvesting the phagemids .The phagemids was imparted into Mycobacterium smegmatis to get recombinant phages with the same AES .A high titer of the recombinant phages was harvested through amplification in vitro . The M .tuberculosis was transfected and coated on solid medium with hygromycin resistance and cultured for 4 weeks at 37℃ .Single clone was picked out and gene knock-out was confirmed by PCR . Then C57BL/6J mice were infected with either wild type strain (WT ) or knockout strain (KO ) of M . tuberculosis .Mice mortality ,lung tissue inflammation and colony-forming units (CFU ) counts in vitro were observed 6 to 8weeks post infection with different strains . Paired-samples t test was used for comparison between groups ,chi-square test was used for comparison of rates .Results The products of PCR and inserted fragment sizes were consisted with the expectation and confirmed to be the target gene . The target fragment of Rv2346c was removed successfully and the mice were infected for 6-8 weeks .Themice infected with Rv2346c KO strain had reduced mortality (53％ vs 20％ ,χ2 =6 .1112 ,P<0 .05) ,lung tissue inflammation (1040 ± 89 vs 1960 ± 56 ,t=7 .1016 ,P<0 .05) and CFU count in vitro (15 .0 ± 0 .8 vs 90 .0 ± 1 .5 ,t=23 .0361 , P<0 .05) compared with WT strain 6-8 weeks post infection .Conclusion Rv2346c gene knockout strains of M . tuberculosis mediated by bacteriophageis are successfully constructed ,which establishes the foundation for the future gene function study of Rv2346c .

Objective:To analyze the data of critical care related literatures published in Web of Science core set by knowledge map visualizing technology, and summarize the research status and hotspots of critical care.Methods:The core set database of Web of Science from January 2011 to December 2020 was searched, the extracted information was standardized and analyzed by knowledge map visualizing technology.Results:A total of 783 articles in the field of critical care were included, and the number of literatures increased year by year, among which the number of articles published in the American Journal of Critical Care(305) was the most. The United States (437) was the country with the most published literatures, and Australia was the country with the highest centrality (centrality=0.67). The number and centrality of articles published from China were at the lower middle level. There was cooperation among countries, but not close cooperation. The cooperation among authors was in the state of small aggregation and large dispersion. Cluster analysis and keyword emergence analysis showed that many aspects in the field of intensive care had been the research hotspots, among which "post intensive care syndrome" and "children′s intensive care" were the research hotspots in recent years.Conclusions:The research field of intensive care is still in the rising stage of development, and post intensive care syndrome and children's intensive care are the latest hotspots in intensive care research.

Objective:To investigate the clinical effect of W-shaped genioplasty in the correction of broad and short chin deformity.Methods:Thirty-eight patients (5 males, 33 females, aged 20 to 41 years, mean 27.3 years) complained with broad and short chin were admitted to the Affiliated Friendship Plastic Surgery Hospitalof Nanjing Medical University from January 2019 to December 2021. CBCT scan and three-dimensional reconstruction were performed to design osteotomy line and determine the distance of chin lengthening, narrowing and advancing or retrocession preoperatively. Under general anesthesia, the W-shaped osteotomy was performed using an intraoral incision, and the angle between the bilateral free bone fragments, the distance of downward and forward movement were adjusted to change the curvature, width, length and prominence of the lower edge of the chin according to the preoperative designs. The results were evaluated by clinical appearances and image analyses at a follow-up of 3-24 months.Results:The amount of vertical lengthening of the chin in 38 cases were 2 mm to 5 mm, with an average of 3.02 mm. The horizontal narrowing width distances were 3-7 mm, with an average of 5.6 mm. The patients were followed up for 3-24 months, with an average of 10.6 months. There were no complications such as hematoma, wound dehiscence, accidental fracture, surgical area infection and permanent neurosensory disorder. 38 patients had transient sensory loss in the lower lip region of varying degrees, but all recovered spontaneously during routine follow-up period. All patients were satisfied with the improvement of facial contour.Conclusions:W-shaped geinoplasty preserves the central bone of the chin and the attachment of genioglossus muscle, which does not affect the normal anatomy and physiological function of the oral cavity. After osteotomy, the bone is removed and the bilateral bone fragments move flexibly. It can effectively change the radian, width, length and protrusion of the lower edge of the chin in three dimensions, so as to correct the wide and short deformity of the chin.