The purpose of the present study was to investigate teacher-dominant action and focus on learning-oriented group.Medical teachers should pay more attention to three important aspects,such as optimizing teaching pattern,dealing with the relationship carefully among pre-class,inter-class and post-class.It is important to attach importance to pre-class,giving prominence to inter-class and also giving attention to post-class,which can form a harmonious,interactive and collaborate class.In addition,it stimulates deep processing interactions between teachers and students by increasing students learning interests,which is very helpful in improving teaching effects of medical image.

Carbon-nitrogen lyases (E.C.4.3) are a group of enzymes that release ammonia, amidine or amino group etc, and also show ability to form double bond or ring structure. Specifically, enzymes forming amino group are called amine-lyases (E.C.4.3.3), which are critical in the industrial production of many medicine intermediates. In this review is a summary of four major amine-lyases in terms of their source, enzymatic characteristics and their applications in preparation of pharmaceutical intermediates.

Tautomycin is one of well-known specific protein phosphatase inhibitors and exhibiting potent antifungal ability, especially to Sclerotinia sclerotiolum. This article reviews the recent research progress of tautomycin, focusing on its inhibition region and biosynthesis.

Phaffia rhodozyma is a good strain for astaxanthin production. An over-producing mutant YB-20-29 was obtained by means of Cs137-?ray and N-methy1-N'-nitro-N-nitrosoguanidin (NTG) treatment. The biomass for this strain by shake culture was 36.32 g/L, the pigment content was 1216.0 ?g/g, an increase of 308% compare to o-riginal strain. The astaxanthin content in broth was 30.9?g /mL. It was a potential strain for astaxanthin over-production.

OBJECTIVETo investigate the effects of using guided bone regeneration (GBR) technique with an bioresorbable collagen membrane for repairing bone defects around dental implants.

METHODSIn 12 mongrel dogs, pure titanium implants were immediately implanted in mandibles after extraction of the mandibular third and fourth premolars of both sides, in which standard bone defects of 3 mm x 3 mm x 5 mm were created at mesial side of the implants. The defects on right side were covered with Co membrane, the left side was uncovered as control. The dogs were sacrificed 1, 2, 4, 6 months postoperatively. The specimens were removed and studied by gross observation, X-ray radiograph, histological examination, scanning electron microscope (SEM) and pull-out test.

RESULTSThe quantity and quality of new bone formation in experimental side which bone defects covered with Co membrane were much better than that in the control side.

CONCLUSIONWith the biodegradable property and excellent biocompatibility, Co membrane can be used for guided bone regeneration to promote the bone repair progress, and the promotion acts mainly at early stage of bone healing.

Animals ; Bone Regeneration ; Collagen ; Dental Implantation, Endosseous ; Dental Implants ; Dogs ; Guided Tissue Regeneration, Periodontal ; Mandible ; Membranes, Artificial ; Titanium

Volatile organic compounds (VOCs) in ambient air can participate in photochemical reactions, which lead to the generation of secondary pollutants such as ozone and aerosol. So real-time and accurate monitoring of atmospheric VOCs plays an important role in the study of the causes of air pollution. On the basis of proton transfer reaction mass spectrometry (PTR-MS) research, a novel dipolar proton transfer reaction mass spectrometer (DP-PTR-MS) for real-time and on-line monitoring atmospheric VOCs was developed. Compared with the conventional PTR-MS with one kind of reagent ion H3O+, DP-PTR-MS had three kinds of reagent ions H3O+, OH-, (CH)2COH+, which could be switched according to the actual detection need. So DP-PTR-MS can improve the qualitative ability and expand the detection range effectively. The reagent ion H3O+can be used for detecting VOCs whose proton affinities are greater than that of H2O. The reagent ion OH-can be used to identify VOCs cooperating with the reagent ion H3O+,and can also be used for detecting some inorganic substances such as CO2. The reagent ion (CH3)2COH+can be used for accurately detecting NH3under interference elimination circumstances. The limit of detection (LOD) and sensitivity of DP-PTR-MS were measured by using six kinds of standard gases. The results showed that the LOD for detecting toluene was 7×10-12(V/V) and the sensitivity for detecting ammonia has reached 126 cps/10-9 (V/V). The ambient air in Hefei city was on-line and real-time monitored for continuous 78 hours with DP-PTR-MS. The results showed that the newly developed DP-PTR-MS could be used for long-term and real-time monitoring atmospheric VOCs with the concentration of 10-12(V/V) level. DP-PTR-MS is an important tool for the study of the causes of atmospheric pollution and the monitoring of trace VOCs emissions.

Objective:To assess the value of cerebral small vessel disease (CSVD) burden in predicting prognosis in acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (LVO) after endovascular therapy (EVT).Methods:The study was a cross-sectional study. A total of 242 patients with AIS due to anterior circulation LVO received EVT in the First Affiliated Hospital of Nanjing Medical University from February 2018 to September 2022. The clinical and imaging data of all patients were analyzed retrospectively. On follow-up MRI within 7 days after EVT, CSVD features [white matter hyperintensity (WMH), lacune, perivascular space, cerebral microbleed, cerebral atrophy] and CSVD burden score (0-5) was evaluated. Modified Rankin scale (mRS) score at 90 days after EVT was assessed. Patients were categorized into a mild burden group (0-1 points) and a moderate-severe burden group (2-5 points) based on CSVD burden score. Meanwhile, patients were categorized into a good prognosis group (0-2 points) and a bad prognosis group (3-6 points) based on mRS score at 90 days after EVT. Mann-Whitney U test and χ2 test were used to compare the difference of clinical and imaging indexes between the 2 groups, and variables with P<0.1 in the univariate analysis were included in the multifactorial logistic regression to screen for independent factors to predict the prognosis. Results:There were 169 patients in the good prognosis group and 73 patients in the bad prognosis group out of 242 patients. Compared with the good prognosis group, age, incidence of hyperlipidemia, baseline National Institutes of Health Stroke Scale (NIHSS) scores, incidence of hemorrhagic conversion, CSVD burden scores, incidence of periventricular WMH scores of 3 and/or deep WMH scores≥2, and incidence of moderate-severe cerebral atrophy of patients in the bad prognosis group were higher, and the incidence of complete recanalization was lower (all P<0.05). Multivariate analysis showed hyperlipemia ( OR=8.438, 95% CI 1.691-42.119, P=0.009), baseline NIHSS score ( OR=1.103, 95% CI 1.047-1.162, P<0.001), complete recanalization ( OR=0.131, 95% CI 0.038-0.454, P=0.001) and hemorrhage transformation ( OR=1.952, 95% CI 1.031-3.697, P=0.040) were independent factors for the prognosis of EVT in patients with LVO AIS. There were 157 cases in the mild burden group and 85 cases in the moderate-severe burden group. The 90-day mRS score was higher in the moderate-severe burden group compared with the mild burden group ( Z=-2.24, P=0.025). Conclusion:CSVD burden has some clinical implications in predicting the prognosis of EVT in patients with anterior circulation LVO AIS.

Objective: To compare and analyze the epidemiological characteristics of hospitalized elderly, young and middle-aged patients with severe burn in recent years, so as to provide reference for the prevention and treatment of elderly patients with severe burn. Methods: Relying on the entry system of epidemiological case data and biological sample of severe burn from multicenter in clinic, medical records of patients with severe burn, aged above 18, hospitalized in 8 burn wards from January 2012 to December 2015 were collected. Six hundred and fifteen patients who were more than 18 years old and less than or equal to 65 years old were included in young and middle-aged group (YM). Eighty-two patients aged more than 65 years old were included in elderly group (E). Data of age, gender, residence, education level, cause of injury, location of injury, season of injury, total burn area, occurrence and area of full-thickness burn injury, wound site, inhalation injury incidence and severity, post burn admission time, proportion of delayed resuscitation, proportion of escharectomy or tangential excision and skin grafting, preinjury systemic disease, system complication during hospitalization, length of hospital stay, outcome of treatment, and reason of abandoning treatment of patients were analyzed. Data were processed with chi-square test and Mann-Whitney U test. The odds ratios of preinjury systemic disease, system complication during hospitalization, and adverse outcome of patients in group YM were compared with those in group E. Results: (1) The majority of patients in the two groups were male, but the proportion of male patients in group YM was higher. There was statistically significant difference in gender distribution of patients between the two groups (χ²=18.727, P<0.001). The majority of patients in the two groups were from rural areas, but the proportion of rural patients in group E was higher. There was statistically significant difference in residence distribution of patients between the two groups (χ²=9.306, P=0.002). Patients in group YM mainly had secondary education, while patients in group E mainly had primary education. There was statistically significant difference in distribution of education level of patients between the two groups (χ²=146.797, P<0.001). (2) The most common causes of injury of patients in the two groups were both flame, but the proportion of patients with flame burn injury in group E was higher. There was statistically significant difference in distribution of cause of injury of patients between the two groups (χ²=25.063, P<0.001). The main locations of injury of patients in groups YM and E were respectively public place and private residence. There was statistically significant difference in location distribution of injury of patients between the two groups (χ²=46.313, P<0.001). The main seasons of injury of patients in groups YM and E were respectively summer and winter. There was statistically significant difference in season distribution of patients between the two groups (χ²=23.143, P<0.001). There was statistically significant difference in distribution of total burn area of patients between the two groups (χ²=25.799, P=0.002). The occurrences of full-thickness burn injury of patients in the two groups were similar (χ²=2.685, P=0.101), while there was statistically significant difference in area of full-thickness burn injury of patients between the two groups (χ²=26.702, P=0.002). There was no statistically significant difference in distribution of wound site of patients between the two groups (χ²=3.954, P=0.785). There were no statistically significant differences in incidence and severity distribution of inhalation injury of patients between the two groups (with χ² values respectively 0.425 and 0.672, P values above 0.05). (3) There was statistically significant difference in distribution of admission time of patients between the two groups (χ²=6.632, P=0.036), but there was no statistically significant difference in proportion of delayed resuscitation of patients between the two groups (χ²=1.261, P=0.261). The proportion of escharectomy or tangential excision and skin grafting of patients in group YM was 72.0% (443/615), which was significantly higher than 35.4% (29/82) of group E (χ²=44.498, P<0.001). The incidence of preinjury systemic disease of patients in group YM was 13.2% (81/615), which was significantly lower than 61.0% (50/82) of group E (χ²=108.337, P<0.001). The risk of preinjury systemic disease of patients in group E was 10.30 times of that of patients in group YM [with 95% confidence interval (CI) of 6.24-17.01, P<0.001]. During hospitalization, 59.8% (49/82) of patients in group E suffered from system complications, which was significantly higher than 36.6% (225/615) of group YM (χ²=16.282, P<0.001). The risk of system complication of patients in group E was 2.57 times of patients in group YM (with 95% CI of 1.61-4.12, P<0.001). The length of hospital stay of patients in group E was significantly shorter than that of group YM (U=36 735, P<0.001). There was statistically significant difference in treatment outcome of patients between the two groups (χ²=106.251, P<0.001). The risk of adverse outcome of patients in group E was 7.52 times of group YM (with 95% CI of 4.40-12.88, χ²=67.709, P<0.001). The proportion of abandoning treatment of patients in group E was significantly higher than that of group YM (χ²=150.670, P<0.001). The risk of abandoning treatment of patients in group E was 15.86 times of that of group YM (with 95% CI of 9.36-26.88, P<0.001). There was no statistically significant difference in distribution of reason of abandoning treatment of patients between the two groups (χ²=4.178, P=0.243). Conclusions There were significant differences in the epidemiological characteristics of patients in groups E and YM. In elderly burn patients, the proportion of rural population was higher and the education level was lower. Flame burn was common and burns mostly occurred in private residences and in winter. The total burn area was slightly lower but the area of full-thickness burn injury was larger. The length of hospital stay was shorter and the proportion of surgical treatment was lower. The incidences of preinjury systemic disease and system complication during hospitalization were higher, and therefore the risks of adverse outcome and abandoning treatment were higher.

Objective This study aimed to investigate the potential relationship between urinary metals copper (Cu), arsenic (As), strontium (Sr), barium (Ba), iron (Fe), lead (Pb) and manganese (Mn) and grip strength. Methods We used linear regression models, quantile g-computation and Bayesian kernel machine regression (BKMR) to assess the relationship between metals and grip strength.Results In the multimetal linear regression, Cu (β=-2.119), As (β=-1.318), Sr (β=-2.480), Ba (β=0.781), Fe (β= 1.130) and Mn (β=-0.404) were significantly correlated with grip strength (P < 0.05). The results of the quantile g-computation showed that the risk of occurrence of grip strength reduction was -1.007 (95％ confidence interval:-1.362, -0.652; P < 0.001) when each quartile of the mixture of the seven metals was increased. Bayesian kernel function regression model analysis showed that mixtures of the seven metals had a negative overall effect on grip strength, with Cu, As and Sr being negatively associated with grip strength levels. In the total population, potential interactions were observed between As and Mn and between Cu and Mn (Pinteractions of 0.003 and 0.018, respectively).Conclusion In summary, this study suggests that combined exposure to metal mixtures is negatively associated with grip strength. Cu, Sr and As were negatively correlated with grip strength levels, and there were potential interactions between As and Mn and between Cu and Mn.

Objective:To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis.Methods:This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924 th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results:Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m 2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions:The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.