A new chitosan derivative is prepared using chitosan.Ethyl chlorocarbonate was first introduced to the hydroxyl group of phthaloylchitosan through a nucleophilic reaction.Hydrazine was then added to recover the amino groups of chitosan and promote cross-linking.The structure of this new chitosan derivative was characterized by Fourier transform infrared（FT-IR）and proton nuclear magnetic resonance（1H NMR）spectroscopy,and its physical properties were determined by X-ray diffraction（XRD）,differential scanning calorimetry（DSC）,and thermogravimetric analysis（TGA）.The thermal and chemical stabilities of the new derivative were improved compared with those of native chitosan.Assay of Escherichia coli adhesion on a film based on this chitosan derivative showed good adsorption and biofilm formation.

A new chitosan derivative is prepared using chitosan.Ethyl chlorocarbonate was first introduced to the hydroxyl group of phthaloylchitosan through a nucleophilic reaction.Hydrazine was then added to recover the amino groups of chitosan and promote cross-linking.The structure of this new chitosan derivative was characterized by Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy,and its physical properties were determined by X-ray diffraction (XRD),differential scanning calorimetry (DSC),and thermogravimetric analysis (TGA).The thermal and chemical stabilities of the new derivative were improved compared with those of native chitosan.Assay of Escherichia coli adhesion on a film based on this chitosan derivative showed good adsorption and biofilm formation.

Abstract A new microfluidic system with four different microchambers （a circle and three equilateral concave polygons） was designed and fabricated using poly（dimethylsiloxane） （PDMS） and the soft lithography method. Using this microfluidic device at six flow rates （5, 10, 20, 30, 40, and 50 μL/h）, the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors were investigated. Escherichia coli HB101 pGLO, which could produce a green fluorescent protein induced by L-arabinose, was utilized as the model bacteria. The results demonstrated that bacterial adhesion was significantly related to culture time, microenvironment geometry, and aqueous flow rates. Adhered bacterial density increased with the culture time. Initially, the adhesion occurred at the microchamber sides, and then the entire chamber was gradually covered with increased culture time. Adhesion densities in the side zones were larger than those in the center zones because of the lower shearing force in the side zone. Also, the adhesion densities in the complex chambers were larger than those in the simple chambers. At low flow rates, the orientation of adhered bacteria was random and disorderly. At high flow rates, bacterial orientation became close to the streamline and oriented toward the flow direction; All these results implied that bacterial adhesion tended to occur in complicated aqueous flow areas.The present study provided an on-chip flow system for physiological behavior of biological cells, as well as provided a strategic cue for the prevention of bacterial infection and biofilm formation.

A new microfluidic system with four different microchambers (a circle and three equilateral concave polygons) was designed and fabricated using poly(dimethylsiloxane) (PDMS) and the soft lithography method.Using this microfluidic device at six flow rates (5,10,20,30,40,and 50 μL/h),the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors were investigated.Escherichia coli HB101 pGLO,which could produce a green fluorescent protein induced by L-arabinose,was utilized as the model bacteria.The results demonstrated that bacterial adhesion was significantly related to culture time,microenvironment geometry,and aqueous flow rates.Adhered bacterial density increased with the culture time.Initially,the adhesion occurred at the microchamber sides,and then the entire chamber was gradually covered with increased culture time.Adhesion densities in the side zones were larger than those in the center zones because of the lower shearing force in the side zone.Also,the adhesion densities in the complex chambers were larger than those in the simple chambers.At low flow rates,the orientation of adhered bacteria was random and disorderly.At high flow rates,bacterial orientation became close to the streamline and oriented toward the flow direction.All these results implied that bacterial adhesion tended to occur in complicated aqueous flow areas.The present study provided an on-chip flow system for physiological behavior of biological cells,as well as provided a strategic cue for the prevention of bacterial infection and biofilm formation.

Objective:To construct an unaccompanied patient ward management system based on the harmony theory and explore its effects in the Department of Breast and Plastic Surgery.Methods:Patients from the Department of Breast and Plastic Surgery, the University of Hong Kong-Shenzhen Hospital from January to July 2021 were selected as the control group ( n=1 213) , who received conventional accompanied care. Those admitted from January to July 2022 were the observation group ( n=1 057) , who received harmonious unaccompanied care. The occurrence rate of adverse events, patient satisfaction, and medical staff's job satisfaction between the two groups were compared. Results:The occurrence rate of adverse events in the observation group (0/1 057) was lower than that in the control group (1/1 213) , with no statistically significant difference ( P>0.05) . Both patients' satisfaction and medical staff's job satisfaction in the observation group were higher than those in the control group, with statistically significant differences ( P<0.05) . Conclusions:The construction of the unaccompanied patient ward management system based on the harmony theory contributes to standardizing high-quality nursing comprehensively. It improves both patients' satisfaction and medical staff's job satisfaction, promoting harmonious doctor-patient relationships.

Objective:To investigate the expression of long non-coding RNA 00665 (LINC00665) in hepatocellular carcinoma (HCC) and its regulatory effect on angiogenesis of hepatocellular carcinoma cells and its potential molecular mechanism.Methods:HCC tissues and corresponding paracancerous tissues of 100 patients with HCC in the First Affiliated Hospital of Nanjing Medical University from May 2016 to April 2017 were collected, and the survival prognosis was compared. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of LINC00665 in HCC tissues and cells. The effect of LINC00665 overexpressed Hep-3B cells on the angiogenesis of human umbilical vein endothelial cells (HUVEC) was examined by tube formation assay and chick chorioallantoic membrane assay. Bioinformatics database predicted the downstream microRNA (miRNA) and target genes of LINC00665, and the relationship between LINC00665, miR-126-5p and vascular endothelial growth factor A (VEGFA) was verified by RT-qPCR, Western blot and dual-luciferase reporter gene assay.Results:The expression level of LINC00665 in HCC (6.5±2.8) was significantly higher than that in paracancer tissues (4.8±3.1), the difference was statistically significant ( t=4.12, P<0.001). According to the median LINC00665 expression level of 100 patients with HCC, the cumulative survival rate of LINC00665 high expression group ( n=50) was lower than that of LINC00665 low expression group ( n=50), and the difference was statistically significant (χ 2=3.79, P=0.008). After co-culture with LINC00665 group (Hep-3B cells overexpressing LINC00665), the length of HUVEC cell tubule formation was (596.0±22.3) μm, and the number of HUVEC cell tubules was (36.3±4.5), which were both higher than NC group with the tubule formation length (127.0±13.5) μm and the number (9.3±1.5) of HUVEC cells co-cultured with Hep-3B cells of control group, and the differences were statistically significant ( t=31.15, 9.82, P<0.001, P=0.001). The chick chorioallantoic membrane assay results were similar to tube formation assay. Western blot detected that the relative expression of VEGFA in LINC00665 group was higher than that in NC group, the difference was statistically significant ( t=7.15, P<0.001). StarBase and DIANA database were used to predict and screen LINC00665 downstream miR-126-5p. StarBase database was used to predict the binding sites of LINC00665/miR-126-5p/VEGFA axis. In dual-luciferase reporter gene assay, the fluorescence intensity of LINC00665 and VEGFA vector co-transfected with miR-126-5p mimics decreased. Conclusion:LINC00665 is highly expressed in HCC and is associated with poor prognosis in patients with HCC. LINC00665 promotes angiogenesis of HCC by regulating the miR-126-5p/VEGFA axis.