BACKGROUND: The tissue engineered corneal epithelium can be constructed with limbal stem cells of healthy rabbit cornea cultured in vitro, and its transplantation may promote the repair and healing of corneal alkaline burn.OBJECTIVE: To probe the effect and opportunity of treating corneal alkaline bum by tissue-engineered corneal epithelium transplantation.DESIGN, TIME AND SETTING: Controlled observational animal experiment was performed in the Department of Experimental Animal at the First Affiliated Hospital of Chinese PLA General Hospital between July 2007 and June 2008.MATERIALS: Twenty-one New Zealand female white rabbits, weighing 2.0-2.5 kg, were divided into control group (n=8, 16 eyes) and transplantation group (n=13, 26 eyes) at random. The transplantation group was further assigned into early transplantation group at 1 day (n=2, 4 eyes), 3 days (n=3, 6 eyes), 6 days (n=6, 12 eyes), and 9 days (n=9, 18 eyes); and mataphase transplantation group at 14 days (n=3, 6 eyes).METHODS: The tissue-engineered corneal epithelium was prepared on 21 rabbits with limbal stem cells cultured in vitro, and reforming comeel alkaline burn models of double eyes were induced by 1 mollL NaOH. The autotogous or allogenic tissue-engineered comeal epithelium transplantation was conducted on early time points (1, 3, 6, 9 days) or metaphase (14 days) after alkaline burning. In the control group, the burns were observed for 4 consecutive weeks.MAIN OUTCOME MEASURES: The ocular surface integrity and histopathology in the transplantation group and control group were observed on several time points within 4 weeks.RESULTS: At 1 weak after corneal alkaline burning, large corneal epithelial dasquamation occurred, 72% incidence of epithelial desquamation or corneal ulcer at 2 weeks, and continued to 4 weeks, while only 25% were observed at 4 weeks in transplantation group, most gained ocular surface integrity; cell infiltration and vascularization of corneal stroma had not bean suppressed in metaphase transplantation group, while they were suppressed obviously in the deep comeal stroma in early transplantation groups; Within 4 weeks, immunological rejection induced by allogenic transplantation was not greater than that of autologous transplantation.CONCLUSION: Cultivated autologous or allogenic tissue-engineered corneal epithelium transplantation could recover ocular surface integrity as soon as possible, and the effect of early transplantation surpasses that of mstaphase.

Objective: To study the effect of three different doses of propofol, midazolam and etomidate on short latency somatosensory evoked potential(SLSEP). Method:Ninety patients undergoing elective operation were randomly divided into 3 groups with 3 subgroups each,and propofol,midazolam,etomidate were administered by bolus injection at propofol 1.5,2,3mg/kg, midazolam 0.2,0.3,0.4mg/kg, etomidate 0.15,0.3,0.4mg/kg accordingly. SLSEP was recorded before,during and after injection. Result:Propofol did not significantly change the latencies of the subcortical N_(14),cortical N_(20) and central conduction time(CCT)N_(14)-N_(20),decreased the interwave amplitude N_(20)-P_(25)(P

In this study, the virtual simulation tutoring system was applied to the teaching of dental residents in the standardized training stage for the first time, including the curriculum preparation, curriculum design and teaching practice. Through the practice of the preparation of class Ⅱ holes and the tooth preparation of PFM (porcelain fused to metal) by the dental residents in the virtual simulation teaching system, the teaching arrangement of three courses as one term was explored. Each course adopted the matching interactive teaching mode. Finally, the transcripts would be given by the virtual simulation teaching system to comment and summarize. This study has laid a foundation for future promotion of virtual simulation teaching system in the standardized training stage of stomatology residents and found a new direction for improving the proficiency and accuracy of residents' clinical operation skills.

Objective To investigate the manifestations and features of CT for glandular cystitis as well as cystic cystitis.Methods Clinical manifestations and CT imaging features of 39 cases with biopsy-proved glandular cystitis or cystic cystitis were analyzed retrospectively.Results Among 39 cases,33 were glandular cystitis and 6 were cystic cystitis.Two out of the 33 cases with glandular cystitis had a negative CT scan,and 31 had a positive CT scan among which 4 cases with extensive lesions showed diffuse thickening of the bladder wall,and 27 were with localized lesions.Furthermore,19 out of the 27 cases showed localized thickening of the bladder wall with smooth edge,which was a continuation of surrounding normal bladder wall;8 showed nodular lesions.17 of the 33 cases with glandular cystitis underwent contrast-enhanced CT scan which showed mildly enhancement consistent with or slightly stronger than the normal bladder wall in 15 cases and moderate uneven enhancement in 2 cases.The 6 cases with cystic cystitis showed diffuse thickened rough bladder wall.There were cystic shadows of various sizes in the inner wall of the bladder partially protruding into the bladder,which presented as a"beaded shape"manifestation.Conclusion The characteristic manifestations of glandular cystitis as well as cystic cystitis on CT scan are of great significance in diagnosing both of the diseases.

Objective:To investigate the features of chest computed tomography (CT) imaging and dynamic changes of severe corona virus disease 2019 (COVID-19).Methods:The clinical and CT data of 17 patients diagnosed with severe COVID-19 admitted to Chongqing Public Health Medical Center from January 24 to February 6, 2020 were collected. The first chest CT manifestations and the dynamic changes of imaging during treatment were retrospectively analyzed.Results:The first chest CT manifestations of the 17 patients showed that 16 cases presented with peripheral and subpleural distributions, and two cases presented with three lobes involved, one case with four lobes involved and 14 cases with five lobes involved, and 17 cases presented with ground-glass opacities, ten cases with consolidation, seven cases with subpleural line, nine cases with air bronchogram, three cases with thickened lobular septum, two cases with bronchiectasis, two cases with pleural effusion, three cases with lymphadenopathy with the short diameter of 1.0-1.2 cm.Among 16 patients who underwent repeated CT examination, the lesions of eight patients showed continuous improvement, and those of the other eight patients showed fluctuating changes.Conclusions:The CT findings of severe COVID-19 patients are mainly ground-glass opacities and consolidation, with the peripheral distribution. The range of lesions is wide, with five-lobe involvement mostly. Lymphadenopathy or pleural effusion is rare. Pynamic monitoring chest CT is useful for the evaluation for the therapeutic effects.

Background/Aims: The shortage of donor liver hinders the development of liver transplantation. This study aimed to clarify the poor outcomes of functionally marginal liver grafts (FMLs) and provide evidence for the improvement of ischemia-free liver transplantation (IFLT) after FML transplantation. Methods: Propensity score matching was used to control for confounding factors. The outcomes of the control group and FML group were compared to demonstrate the negative impact of FMLs on liver transplantation patients. We compared the clinical improvements of the different surgical types. To elucidate the underlying mechanism, we conducted bioinformatic analysis based on transcriptome and single-cell profiles. Results: FMLs had a significantly greater hazard ratio (HR: 1.969, P=0.018) than did other marginal livers. A worse 90-day survival (Mortality: 12.3% vs. 5.0%, P=0.007) was observed in patients who underwent FML transplantation. Patients who received FMLs had a significant improvement in overall survival after IFLT (Mortality: 10.4% vs 31.3%, P=0.006). Pyroptosis and inflammation were inhibited in patients who underwent IFLT. The infiltration of natural killer cells was lower in liver grafts from these patients. Bulk transcriptome profiles revealed a positive relationship between IL-32 and Caspase 1 (R=0.73, P=0.01) and between IL-32 and Gasdermin D (R=0.84, P=0.0012). Conclusions FML is a more important negative prognostic parameter than other marginal liver parameters. IFLT might ameliorate liver injury in FMLs by inhibiting the infiltration of NK cells, consequently leading to the abortion of IL-32, which drives pyroptosis in monocytes and macrophages.

Objective: To investigate the features of chest CT imaging and dynamic changes of severe coronavirus disease 2019 (COVID-19). Methods: The clinical and computed tomography (CT) data of 17 patients diagnosed with severe COVID-19 admitted to Chongqing Public Health Medical Center from January 24 to February 6, 2020 were collected. The first chest CT manifestations and the dynamic changes of imaging during treatment were retrospectively analyzed. Results: The first chest CT manifestations of the 17 patients showed that 16 cases presented with peripheral and subpleural distributions, and 2 cases presented with 3 lobes involved, one case with 4 lobes involved and 14 cases with 5 lobes involved, and 17 cases presented with ground-glass opacities, ten cases with consolidation, seven cases with subpleural line, nine cases with air bronchogram, 3 cases with thickened lobular septum, two cases with bronchiectasis, two cases with pleural effusion, two cases with lymphadenopathy with the short diameter of 1.0-1.2cm. Among 16 patients who underwent repeated CT examination, the lesions of 8 patients showed continuous improvement, and those of the other 8 patients showed fluctuating changes. Conclusions The CT findings of severe COVID-19 patients are mainly ground-glass opacities and consolidation, with the peripheral distribution. The range of lesions is wide, with 5-lobe involvement mostly. Lymphadenopathy or pleural effusion is rare. Chest CT is useful for the evaluation for the therapeutic effects.

Polyhydroxyalkanoates (PHAs) are polymers obtained by esterification of hydroxy fatty acid monomers. Due to similar mechanical characteristics of traditional petroleum-based plastics, 100% biodegradability and biocompatibility, PHAs are considered to be one of the most potential green materials. However, the application and promotion of PHAs as a green and environmentally friendly material are difficult because of the high production costs. This article focuses on the current methods to reduce production cost of PHAs effectively, such as cell morphology regulation, metabolic pathway construction, economic carbon source utilization and open fermentation technology development. Despite most research results are still limited in laboratory, the research methods and directions provide theoretical guidance for the industrial production of economic PHAs.
Fermentation ; Industry ; Petroleum ; Plastics ; Polyhydroxyalkanoates