Virtual reality (VR) medical education resources are widely used in theoretical teaching and clinical skill training, but they are still in the primary stage. VR medical education resources have higher requirements for the compatibility of resource management platforms, greater difficulties and costs in resource construction, and stronger demand for copyright protection, but there is still a lack of effective VR medical resource management platforms and operating mechanisms to mobilize the enthusiasm of all participants in resource construction and application. For the key problems in VR medical education resource management, this article proposes a cloud VR medical education resource management framework based on blockchain and cloud VR technology, specifically designs the function of each module, elaborates on its operation and management mechanisms, and analyzes the effect of such framework, so as to improve the efficiency of cloud VR medical education resource management and promote the construction and shared application of cloud VR medical education resources.

Sweet potato is an important food crop that can also be used as an industrial raw material. Sucrose is the main form of long-distance carbohydrate transport in plants, and sucrose transporter (SUT) regulates the transmembrane transport and distribution of sucrose during plant growth and metabolism. Moreover, SUT plays a key role in phloem mediated source-to-sink sucrose transport and physiological activities, supplying sucrose for the sink tissues. In this study, the full-length cDNA sequences of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were obtained by rapid amplification of cDNA ends (RACE) cloning according to the transcripts of the two SUT coding genes which were differentially expressed in sweet potato storage roots with different starch properties. Phylogenetic analysis was performed to clarify the classification of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆. The subcellular localization of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ was determined by transient expression in Nicotiana benthamiana. The function of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sucrose and hexose absorption and transport was identified using yeast functional complementarity system. The expression pattern of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sweet potato organs were analyzed by real-time fluorescence quantitative PCR (RT-qPCR). Arabidopsis plants heterologous expressing IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ genes were obtained using floral dip method. The differences in starch and sugar contents between transgenic and wild-type Arabidopsis were compared. The results showed IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ encoded SUT proteins with a length of 505 and 521 amino acids, respectively, and both proteins belonged to the SUT1 subfamily. IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were located in the cell membrane and were able to transport sucrose, glucose and fructose in the yeast system. In addition, IbSUT₆₂₇₈₈ was also able to transport mannose. The expression of IbSUT₆₂₇₈₈ was higher in leaves, lateral branches and main stems, and the expression of IbSUT₈₁₆₁₆ was higher in lateral branches, stems and storage roots. After IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were heterologously expressed in Arabidopsis, the plants grew normally, but the biomass increased. The heterologous expression of IbSUT₆₂₇₈₈ increased the soluble sugar content, leaf size and 1 000-seed weight of Arabidopsis plants. Heterologous expression of IbSUT₈₁₆₁₆ increased starch accumulation in leaves and root tips and 1 000-seed weight of seeds, but decreased soluble sugar content. The results obtained in this study showed that IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ might be important genes regulating sucrose and sugar content traits in sweet potato. They might carry out physiological functions on cell membrane, such as transmembrane transport of sucrose, sucrose into and out of sink tissue, as well as transport and unloading of sucrose into phloem. The changes in traits result from their heterologous expression in Arabidopsis indicates their potential in improving the yield of other plants or crops. The results obtained in this study provide important information for revealing the functions of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in starch and glucose metabolism and formation mechanism of important quality traits in sweet potato.
Ipomoea batatas/metabolism* ; Arabidopsis/metabolism* ; Sucrose/metabolism* ; Saccharomyces cerevisiae/metabolism* ; DNA, Complementary ; Phylogeny ; Plants, Genetically Modified/genetics* ; Membrane Transport Proteins/metabolism* ; Starch/metabolism* ; Plant Proteins/metabolism* ; Gene Expression Regulation, Plant

Objective:To investigate the clinical effect of free fibula flap transplantation in repairing the defect of mandibular osteoradionecrosis (ORN).Methods:A total of 151 mandibular ORN patients undergoing free fibular flap transplantation were selected from August 2005 to September 2020 in the Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University. Among them, 109 patients were males and 42 patients were females, aged (54.1±10.1) (ranged 31-85) years old. The clinical data of the patients was collected and the survival rate of the flaps and postoperative function were calculated to evaluate the surgical efficacy. The χ 2 test was used for difference analysis. Results:Among the 151 patients, mandibular ORN caused by radiotherapy for nasopharyngeal carcinoma accounted for 79.5% (120/151). The average time for mandibular ORN appeared was 5(6) years after radiotherapy. Facial artery [57.2%(87/152)] and superior thyroid artery [32.9%(50/152)] were the main anastomotic arteries in the recipient area. There was no significant difference in the necrosis rates of the two flaps [10.3%(9/87) and 12.5% (5/50), respectively, P=0.949]. The main anastomotic veins in the recipient area were the external jugular vein [48.4%(135/279)] and the common facial vein [26.5%(74/279)]. Twenty-five cases (16.6%) had one vein anastomosed, and 126 cases (83.44%) had two veins anastomosed. There was no significant difference in the flap necrosis rate between the two conditions [20.0%(5/25) and 7.1%(9/126), respectively, P=0.100]. Ninety-seven cases (64.2%) used the peroneal musculocutaneous-fascia composite flap to repair the maxillofacial soft and hard tissue defects. Thirteen cases (8.6%) underwent the restorations with digital virtual surgery design, of which 5 cases were repaired with dental implants at the same time. After the operations, lower respiratory tract infection occurred in 17 patients (11.3%), and upper respiratory tract obstruction occurred in 3 cases (2.0%). The survival rate of the flap after operation was 90.7% (136/151), and 21 patients (13.9%) had flap vascular crisis. Delayed healing of maxillofacial wounds occurred in 33 cases (21.9%). After 3 to 24 months of follow-ups, 110 patients (76.9%) had no fistula inside/outside the oral cavity, 118 patients (82.5%) had an improvement in opening mouth of increasing (≥0.5 cm) after surgery, 135 patients (94.4%) had pain relief, 97 cases (67.8%) could eat normal diet, semi-liquid or soft food, and 137 cases (95.8%) were satisfied or basically satisfied with the treatment effects. Conclusions:The free fibular flap transplantation is an effective method to repair mandibular ORN defects. Preoperative vascular assessment is helpful for the selection of recipient vessels. Facial artery, superior thyroid artery, external jugular vein and common facial vein can be used as the main recipient vessels. The repair of the peroneal musculocutaneous-fascia composite flap facilitates the closure of internal and external fistulas. Digital technology can help to restore the maxillofacial shape more accurately, improve the patient′s occlusal and chewing function and enhance the quality of life of mandibular ORN patients.

2019-novel coronavirus (2019-nCoV) is a highly pathogenic human CoV that first emerged in Wuhan in 2019.2019-nCoV has a zoonotic origin and poses a major threat to public health.However, little is known about the viral factors contributing to the high virulence of 2019-nCoV.Many animal viruses, including CoVs, encode proteins that interfere with host gene expression, including those involved in antiviral immune responses, and these viral proteins are often major virulence factors.Human coronaviruses (HCoVs) are known respiratory pathogens associated with a range of respiratory infection.In the past 17 years, the onset of 2019-nCoV, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) have thrust HCoVs into spotlight of the research community due to their high pathogenicity in humans.The recent study of HCoVs-host interactions has contributed extensively to our understanding of infection pathogenesis of 2019-nCoV.This review discuss various host physiopathologic mechanism, such as apoptosis, innate immunity, endoplasmic reticulum (ER) stress response, mitogen-activated protein kinase (MAPK) pathway and nuclear factor kappa B (NF-κB) pathway that may be modulated by HCoVs and provides evidence for the intensive investigate of 2019-nCoV infection.

Objective:To improve the Rapid Arterial Occlusion Evaluation (RACE) scale and to investigate its value in identifying large vessel occlusion (LVO) in patients with acute anterior circulation ischemic stroke (AIS).Methods:Consecutive patients with AIS treated in Liangxiang Hospital of Fangshan District, Beijing through stroke easy access from January 1, 2016 to December 31, 2018 were enrolled prospectively. The clinical data and multimodal CT examinations required to determine LVO were collected. The existing problems in the RACE score were modified. The patients were evaluated by the modified RACE score, RACE score, and National Institute of Health Stroke Scale (NIHSS). The receiver operator characteristic (ROC) curve was used to evaluate the predictive ability of the modified RACE score for LVO, and it was compared with the RACE score and NIHSS score. The ROC curves of LVO predicted by modified RACE score and NIHSS score in patients with left and right hemispheric lesions were compared.Results:A total of 184 patients were included, of which 66 (35.9%) had LVO. The age (64.8±11.7 vs. 60.5±10.8 years; t=2.483, P=0.014), baseline NIHSS score (13 [6.75-17] vs. 5 [2-9]; Z=-6.361, P<0.001) and the proportion of patients with gaze (37.9% vs. 17.4%; χ2=4.696, P=0.030) in the LVO group were significantly higher than those in the non-LVO group. ROC curve showed that the modified RACE score was more effective in identifying LVO than RACE score (area under the curve: 0.812 vs. 0.770; Z=4.654, P<0.001). The best cutoff value of the modified RACE score in predicting LVO was 5, and its predictive sensitivity and specificity were 75.8% and 75.4%, respectively, and the positive and negative predictive values were 63.3% and 84.8%, respectively. A comparison of patients with left hemispheric lesion and those with right hemispheric lesion showed that the ability of the modified RACE score in predicting LVO was more balanced (area under the curve: 0.826 vs. 0.796; Z=0.454, P=0.650), while there was a significant difference in NIHSS score (area under the curve: 0.856 vs. 0.703; Z=2.149, P=0.031). Conclusions:The modified RACE score is better than the original RACE score in the predictive value of LVO in patients with AIS, and its predictive power of LVO in patients with left and right hemisphere stroke is more balanced than the NIHSS score, which may help clinical discrimination and screening for patients suitable endovascular treatment.

Objective To investigate maternal zinc metabolism and the changes of zinc-related factors as metallothionein-1 (MT1) and zinc transporter-1 (ZnT1) in certain types of congenital heart diseases (CHD).Methods Fifteen infants with interventricular septal defect,12 infants with atrial septal defect and 7 infants with tetralogy of Fallot,together with their mothers were enrolled,and normal infants and their mothers were enrolled by a ratio of 1 ∶ 1 with the above three types of CHD diseases.General conditions of the mothers,along with their diets and zinc-containing drug supplementation during the pregnancy,were surveyed.Maternal blood zinc levels and serum alkaline phosphatase activities at gestation week 32 and delivery or induced abortion,and the protein and mRNA expressions of MT1 and ZnT1 in maternal serum and placental tissue at delivery or induced abortion were assayed.Results The general conditions were comparable between the CHD group and control group.The ratio of the mothers taking more zinc-rich food was significantly lower in the CHD group than in the control group.Circulating zinc levels in interventricular septal defect (73.55±5.79 μmol/L),atrial septal defect (72.66±5.82 μmol/L) and tetralogy of Fallot (68.72±6.72 μmol/L) groups were significantly lower than those in the control groups (82.77± 7.88,84.58 ± 7.55 and 85.66 ± 7.30 μmol/L) at delivery (P all ＜ 0.05).Similar change patterns were seen for serum alkaline phosphatase activities.The relative quantities of serum MT1 and ZnT1 proteins in interventricular septal defect (73.22±36.54 and 68.55± 27.82),atrial septal defect (64.29± 38.26 and 74.55 ± 29.67) and tetralogy of Fallot (67.88± 30.50 and 70.13±29.65) groups were significantly lower than those in their corresponding control groups (166.31±67.43and 97.67±30.22,182.56±71.40 and 111.65±32.70,and 173.81±62.36 and 108.27±28.52,P＜0.01 or P＜0.05).The relative quantities of placental MT1 and ZnT1 proteins and mRNA expressions in interventricular septal defect (protein quantities 0.438±0.096 and 0.384±0.061,mRNA expressions 1.23±0.82 and 0.96±0.39),atrial septal defect (0.427±0.093 and 0.377±0.059,1.17±0.70 and 0.85±0.40) and tetralogy of Fallot (0.414±0.111 and 0.336±0.066,1.31±0.97 and 0.90±0.38) groups were significantly lower than those in their corresponding control groups (protein quantities 0.565±0.083 and 0.541±0.090,mRNA expressions 2.78± 1.06 and 1.67±0.33;protein quantities 0.622±0.136 and 0.493±0.079,mRNA expressions 2.85±0.89 and 1.72±0.38;protein quantities 0.637±0.125 and 0.521±0.089,mRNA expressions 3.21 ± 0.99 and 1.61±0.29;P＜0.01 or P＜0.05).Conclusion Mothers with their fetus of certain types of CHD are found zinc deficiency,and down-regulation of MT1 and ZnT1 expressions in the serum and placenta may involve in the pathogenesis of CHD when maternal zinc deficiency.

BACKGROUND: Traditional open surgery will do great damage to the patients with thoracolumbar fractures, and easily induces local degeneration. In contrast, the novel method is minimally invasive, which contributes to the functional recovery of the spine.OBJECTIVE: To discuss the essential procedures and precautions in the treatment of thoracolumbar fractures with percutaneous pedicle screw fixation.METHODS: Twenty-seven cases of single-level thoracolumbar fractures without spinal neurological deficits treated with percutaneous pedicle screw fixation were selected. The operation time and intraoperative blood loss were observed. The Visual Analogue Scale scores during axial turning at baseline and 3 days postoperatively, and the Visual Analogue Scale scores of the operation region at 1 and 3 days postoperatively were detected, respectively.RESULTS AND CONCLUSION: (1) Twenty-seven patients with 108 vertebrae underwent percutaneous pedicle screw fixation under the guidance of the needle, the puncture was smooth, 98 vertebrae was punctured successfully once, and 10 vertebrae were punctured successfully twice. (2) The Visual Analogue Scale scores during axial turning at 3 days postoperatively were significantly lower than those at baseline, and the scores of the operation region at 3 days postoperatively were significantly lower than those at 1 day postoperatively (P < 0.001). (3) The mean operation time was (109±18) minutes, and the mean intraoperative blood loss was (60±16) mL. (4) There were no nerve root injury and other complications. (5) Our results indicate that percutaneou pedicle screw fixation is a minimally invasive and safe method to treat the patients suffering single-level thoracolumbar fractures without spinal neurological deficits.

Objective To investigate the relationship between maternal exposure to airborne inhalable particulate matters (PM10) in the first trimester of pregnancy and the risk of fetal congenital deformity.Methods Relationship between exposure to airborne PM10 during the 1st,2nd,3rd and 1-3 months of gestation and the risk of fetal anomalies in 203 pregnant women with deformed fetuses,which paralleled to normal pregnant women with discrepancy of conception date ＜30 days (control),were retrospectively analyzed by a case-control study from May 14,2007 to April 30,2012 in Fujian Medical University and Fuzhou General Hospital.Multivariate Logistic regression adjusted for potential confounders including maternal age,gravidity and parity was performed for data analysis.Results According to the inclusion and exclusion criteria,178 pregnant women with deformed fetuses and 356 controlled cases were enrolled.The average levels of PM10 exposed in pregnant women Withfetal cardiovascular anomalies during 1-3 months of gestation were significantly higher than in the controls [(73.80±11.55) μg/m3 vs (70.49±10.83) μg/m3] (t=2.066,P=0.040),but PM10 exposure in the 1st,2nd and the 3rd month of pregnancy were comparable between the observed and control groups [(74.00±17.34) μg/m3 vs (71.70±15.39) μg/m3,t=0.992,P=0.322;(75.15±16.80) μg/m3 vs (71.38±15.66) μg/m3,t=1.625,P=0.106; (70.28±15.84) μg/m3 vs (69.41± 15.84) μg/m3,t=0.383,P=0.702].There were no significant differences of PM10 exposure levels when compared between facial-cervical anomalies,neurologic anomalies and total anomalies and their corresponding controls (P＞0.05).Each increased quartile of the PM10 exposure levels was associated with an elevated risk of fetal cardiovascular anomalies by 1.218 folds (OR =2.218,95 ％ CI:1.232-3.994,P=0.008).Paired multivariate Logistic regression analysis revealed,a positive correlation between PM10 levels at 1-3 months of gestation and fetal cardiovascular anomalies (OR =1.106,95％CI:1.035-1.183,P =0.003).Conclusions Maternal exposure to PM10 in the first trimester of pregnancy possibly exerts negative effects on fetal cardiovascular anomalies.

Objective To investigate subacute exposure of airborne particulate matter (PM) on pregnancy and fetal development in female mice. Methods Forty female and forty male ICR adult mice group (A), small (B) , middle (C) , large (D) or overdose (E) PM challenge groups (n = 8 - 11), and were administered with 30 μl of phosphate buffered solution (A) or resuspended standard PM SRM 1649a at 0.09 (B), 0.52 (C), 1.85 (D) or 69.2 (E) μg/μl, once per trid from d 0 till d 19 of pregnancy via instillation onto the base of the tongue. Fetal mice were harvested by cesarean section at the time when spontaneous delivery occurred. Body weight of the pregnant mice, gestational days, intrauterine survival and growth, hepatic and pneumonic histopathological changes of the fetal mice were investigated. Lung/body and liver/body weight ratios were calculated. Expressions of mRNA and protein of CYP1A1 in the fetal lung and CYP1 A2 in the fetal liver were assayed. Results (1) All of the pregnant mice survived pregnancy throughout the entire experiment. Body weight of the pregnant mice was not significantly different among all the groups at gestational d 1 and 7 (P ＞ 0.05), but significantly lower in group E [(41.8 ± 5.8) and (48.9 ± 8.9) g] than in group A [(45.9 ± 1.8) and (56.2 ± 4.9) g] at gestational d 14 and 18 (P ＜0.05). The gestational days were significantly decreased in group E [(19.3 ± 1.3) d] when compared with group A [(20.5 ± 0.7) d; P ＜ 0.05] and were not significantly different among groups A, B, C and D (P ＞ 0.05). Lung/body and liver/body weight ratios of the fetal mice were significantly increased in group E [(1.21 ±0.18) and (4.68 ±0.21)%] as compared with groups A, B, C and D (P＜0.05). (2)Mortality rates of the fetuses were significantly higher in group E (23.0%) than in groups A (0.8%), B (0.9%), C (1.7%) and D (3.7%) (P ＜ 0.05), but were not significantly different among groups A,B, C and D (P ＞ 0.05) despite of an increasing tendency. (3) Pathological changes in the liver and lung of the fetuses were conspicuous in group E. The fetal liver injury was histopathologically evidenced by deranged tissue structure, degenerated parenchyma of hepatic cells, and mildly stained cytoplasm. Adipose degeneration was represented by clear-boundary intracytoplasmic vacuoles in most of the liver cells, and cell pyknosis with heavily stained cytoplasm was observed in some of the liver cells. Inflammatory cell infiltration and focal necrosis were occasionally found in the hepatic tissue. The fetal lung exhibited bronchiole with narrow lumina, vascular engorgement in the submucosal layer, interstitial and alveolar edema, thickened alveolar septum, granulocyte and lymphocyte infiltrations within the pulmonary alveoli and around the bronchioles. The above pathological changes were lesser in groups C and D, and were not or least found in groups A and B. (4) Protein expressions of CYP1A1 in the fetal lung and CYP1A2 in the fetal liver were significantly increased in group E (1.20 ± 0.40 and 2.55 ± 0.89) when compared with group A (0.77 ±0.36 and 2.08 ±0.31) (P ＜ 0.05). mRNA expressions of CYP1A1 in the fetal lung were significantly increased in groups C (0.36 ±0.12), D (0.41 ±0.08) and E (0.43 ±0.11) compared with group A (0.21 ±0.10), and significantly increased in groups D and E compared with group B (0.28 ±0.10,P＜0.05). mRNA expressions of CYP1 A2 in the fetal liver were significantly increased in groups C (0.37 ±0.13), D (0.36 ±0.14) and E (0.43 ±0.16) compared with group A (0.21 ±0.03), and significantly increased in group E compared with group B (0.24± 0.11, P ＜ 0.05). Conclusions PM elicited embryotoxigenicity and resulted in adverse pregnancy outcomes in mice by intrauterine exposure of overdose PM. The expressions of cancer-related genes CYP1A1 and CYP1A2 were up-regulated in organs after the middle- and large-dose subacute exposure of PM, which may have a potential role on the future development.

Objective To investigate the efficacy of pancreaticoduodenectomy (PD) combined with vascular resection and reconstruction.Methods The clinical data of 56 patients who received PD combined with vascular resection and reconstruction at the Southwest Hospital of Third Military Medical University from January 2007 to May 2011 were retrospectively analyzed.The incidence of perioperative complications,mortality and postoperative conditions were also analyzed.Results The mean operation time and intraoperative blood transfusion were 473 minutes (range,234-853 minutes) and 781 ml (range,0-900 ml),respectively.Seven patients did not receive blood transfusion.The median period of hospital stay was 25.9 days (range,17-100 days).A total of 43 patients underwent PD combined with vascular reconstruction.The incidence of perioperative complications and mortality rate were 34％ (19/56) and 7％ (4/56),respectively.There were 42 patients with pancreatic ductal adenocarcinoma,5 with ampullary carcinoma,3 with distal bile duct carcinoma,4 with papillary carcinoma of duodenum,1 with pancreatic neuroendocrine carcinoma and 1 with pancreatic serous cystadenoma.All patients were followed up till August 2011,and the 1-year survival rate was 57％ (32/56).The mean survival time was 13.5 months.The weight of 32 surviving patients increased and no abdominal pain occurred.Within 3 months after the operation,5 patients had slight diarrhea and were administered antidiarrheal; thrombosis in the artificial blood vessels and peritoneal effusion were found in 1 patient,while 6 months later,collateral circulation was formed and the peritoneal effusion was diminished.Conclusion PD combined with vascular resection and reconstruction can improve the quality of life for patients with pancreatic cancer and with blood vessels involvement.