基于素养导向的生物科技微课的研发与实践——以“吃货玩转生物小实验”系列微课为例

为了优化校外生物科技教育活动的形式和内容,满足学生发展需求,我们研发了“吃货玩转生物小实验”系列微课,以期为校外教育生物科技活动的创新发展提供有益的启示。

利用生物化学趣味小实验激发学习的兴趣

作为一门实践性很强的基础科目, 化学也是我们高中生应当重视的一门科目, 特别是在学习过程中, 不仅仅需要注重学习的效率与方法, 同时还需要通过各类方法不断加强自身对科目学习的兴趣, 从而保证今后学习的持续性与长期性.而实验学习以直观性与引导性影响着我们对于生物化学学习的热情与兴趣, 对于我们高中生深入了解化学具有重要的意义, 因而在生物化学学习过程中注重实验学习也是十分必要的.

初中生物家庭小实验的组织与实施——减负下生物学教学的设想

从生物家庭小实验课题的选择、常见家庭小实验、实验材料和准备、实验的组织和实施、总结和评价等多角度进行了分析和总结，认为进行家庭小实验具有一定的可行性和价值。

开发生物家庭小实验 辅助高考专题复习——温州农村酿酒调查

体现新课程理念，开展和开发生物课外家庭小实验，探索高三复习课新模式，同时为开发具有本地特色的生物研究性课程提供素材。

Overexpression of NK2 inhibits liver regeneration after partial hepatectomy in mice

AIM： To investigate the in vivo effects of NK2 on liver regeneration after partial hepatectomy （PH）. METHODS： Survival after PH was observed with 21 NK2 transgenic mice and 23 wild-type （WT） mice over 10 d. Liver regeneration was analyzed using histology and immunohistochemistry. Expressions of genes were analyzed using Northern blot analysis, immunoprecipitation and immunoblotting, and reverse transcriptase polymerase chain reaction assay. Kaplan Meier method and the log-rank test were used for analyzing the survival after PH. Differences in the results of immunohistochemistry and percentage of liver regeneration was determined by the Student＇s t-test. RESULTS： More than half of NK2 transgenic mice died within 48 h after PH. After PH, increased deposition of small lipid droplets in hepatocytes was evident and hepatic proliferation was inhibited in NK2 transgenic mice. The hepatic expression and kinase activity of HGF receptor, c-Met, were unchanged among WT mice and NK2 transgenic mice after PH. The expression of tumor necrosis factor-co （TNF-c0 and interleukin-6 （IL-6） in liver tissues were prolonged in NK2 transgenic mice that died after PH. CONCLUSION： Our findings indicate that overexpression of NK2 inhibits liver regeneration after PH.

Treatment of metastatic colorectal carcinomas by systemic inhibition of vascular endothelial growth factor signaling in mice

AIM： Tumor angiogenesis has been shown to be promoted by vascular endothelial growth factor （VEGF） via stimulating endothelial cell proliferation, migration, and survival. Blockade of VEGF signaling by different means has been demonstrated to result in reduced tumor growth and suppression of tumor angiogenesis in distinct tumor entities. Here, we tested a recombinant adenovirus, AdsFItl-3, that encodes an antagonistically acting fragment of the VEGF receptor 1 （Fit-l）, for systemic antitumor effects in pre-established subcutaneous CRC tumors in mice.METHODS： Murine colorectal carcinoma cells （CT26） were inoculated subcutaneously into Balb/c mice for in vivo studies. Tumor size and survival were determined. 293 cell line was used for propagation of the adenoviral vectors. Human lung cancer line A549 and human umbilical vein endothelial cells were transfected for in vitro experiments.RESULTS： Infection of tumor cells with AdsFlt1-3 resulted in protein secretion into cell supernatant, demonstrating correct vector function. As expected, the secreted sFlt1-3 protein had no direct effect on CT26 tumor cell proliferation in vitro, but endothelial cell function was inhibited by about 46% as compared to the AdLacZ control in a tube formation assay. When AdsFlt1-3 （5×10^9 PFU/animal） was applied to tumor bearing mice, we found a tumor inhibition by 72% at d 12 after treatment initiation, in spite of these antitumoral effects, the survival time was not improved. According to reduced intratumoral microvessel density in AdsFlt1-3-treated mice, the antitumor mechanism can be attributed to angiostatic vector effects. We did not detect increased systemic VEGF levels after AdsFlt1-3 treatment and liver toxicity was low as judged by serum alanine aminotransferase determination.CONCLUSION： In this study we confirmed the value of a systemic administration of AdsFItl-3 to block VEGF signaling as antitumor therapy in an experimental metastatic colorectal carcinoma model in mice.

Effects of social isolation stress on immune response and survival time of mouse with liver cancer

AIM： To investigate the effects of isolation stress on mouse with liver cancer and possible associated mechanisms. METHODS： Transplantable murine hepatoma22 （H22） model was used to evaluate the effects of social isolation stress on murine liver cancer. Mice were immunized with sheep red blood cell （SRBC） and intraperitoneally inoculated with H22 cell, then divided into two groups, one reared individually as group （I） and the other reared in groups as group （G）. Titer of antibody to SRBC and interleukin 2 （IL-2） in serum was monitored. The survival time of mouse with liver cancer was observed. RESULTS： The titer of antibody to SRBC in group （G） was 1：24.5 and that in group （I） was 1：11.2. There was a significant difference between these two groups （t = 2.60, P = 0.02）. A significant difference in IL-2 concentration was observed between group （G） （39.6 ng/L） and group （I） （47.1 ng/L, t = 2.14, P = 0.046）. The survival time in group （G） （16.5 d） was markedly longer than that in group （I） （13.2 d, t = 3.46, P = 0.002）. CONCLUSION： Our study suggests that survival time of the mouse bearing H22 tumor is affected by the social isolation stress and the associated mechanism may be the immunological changes under the social isolation stress.

A critical role of gastric mucosal ascorbic acid in the progression of acute gastric mucosal lesions induced by compound 48/80 in rats

AIM: To study the role of gastric mucosal ascorbic acid(AA) in the progression of acute gastric mucosal lesions induced by compound 48/80 (C48/80), a mast cell degranulator, in rats.METHODS: C48/80 (0.75 mg/kg) was intraperitoneally injected to fasted Wistar rats. Oral administration of AA (10, 50 or 100 mg/kg) was performed 0.5 h after C48/80treatment. Determinations for gastric mucosal lesion severity and blood flow, and assays for gastric mucosal total AA, reduced AA, oxidized AA, vitamin E, thiobarbituric acid reactive substances (TBARS), adherent mucus, nitrite/nitrate (NOx), non-protein SH (NPSH), and myeloperoxidase(MPO), and serum total AA, reduced AA, oxidized AA,and NOx were conducted 0.5 and 3 h after C48/80treatment.RESULTS: Gastric mucosal lesions occurred 0.5 h after C48/80 treatment and progressed at 3 h. Gastric mucosal blood flow decreased 0.5 h after C48/80 treatment but the decrease was recovered at 3 h. Gastric mucosal total AA, reduced AA, vitamin E, and adherent mucus concentrations decreased 3 h after C48/80 treatment.Gastric mucosal oxidized AA concentration remained unchanged after C48/80 treatment. Gastric mucosal NPSH concentration decreased 0.5 h after C48/80 treatment,but the decrease was recovered at 3 h. Gastric mucosal TBARS concentration and MPO activity increased 0.5 h after C48/80 treatment and further increased at 3 h.Serum total AA and reduced AA concentrations increased 0.5 h after C48/80 treatment and further increased at 3 h, while serum oxidized AA concentration increased at 0.5 h. Serum and gastric mucosal NOx concentrations increased 3 h after C48/80 treatment. AA administration to C48/80-treated rats at 0.5 h after the treatment prevented the gastric mucosal lesion progression and the changes in gastric mucosal total AA, reduced AA, vitamin E, adherent mucus, NOx, and TBARS concentrations and MPO activity and serum NOx concentration found at 3 h after the treatment dose-dependently. The AA administration to C48/80-treated rats caused further increases in serum total AA and reduced AA concentrations at 3 h after the treatment dose-dependently.CONCLUSION: Gastric mucosal AA plays a critical role in the progression of C48/80-induced acute gastric mucosal lesions in rats.

Effect of synbiotics on intestinal microflora and digestive enzyme activities in rats

AIM: To investigate the effect of synbiotics, i.e. probiotics and prebiotics mixture, on the gut microbial ecology and digestive enzyme activities in rats. METHODS: Forty-eight SD rats weighing about 280 g were used in this study. Rats were divided into three groups according to the contents of probiotics and prebiotics mixture in the feed as control, low and high dose groups. The duration of the experiment was 8 wk. RESULTS: Compared with the control group, thefecal Lactobacillus and Bifidobacterium counts were significantly increased and the fecal Coliform organism counts were markedly reduced in the low and high dose groups. Concerning the digestive enzyme activity of jejunum, only lactase activity increased in low dose group. However, significant increase of lipase, lactase, sucrase, and isomaltase activities were observed in high dose group.CONCLUSION: Intake of low and high dosages of probiotics and prebiotics mixture significantly improved the ecosystem of the intestinal tract by increasing the probiotics population and digestive enzyme activities in rats.

Vascular endothelial growth factor and angiopoietins regulate sinusoidal regeneration and remodeling after partial hepatectomy in rats

AIM： To study the regulatory mechanisms of sinusoida regeneration after partial hepatectomy. METHODS： We invesldgated the expression of angiopoietin （Ang）-1, Ang-2, Tie-2, and vascular endothelial growth factor （VEGF） in regenerating liver tissue by quantitative reverse-transcription polymerase chain reaction （RT- PCR） using a LightCycler （Roche Diagnostics） and also immunohistochemical staining after 70% hepatectomy in rats. In the next step, we isolated liver cells （hepatocytes, sinusoidal endothelial cell （SEC）, Kupffer cell, and hepatic stellate cells （HSC）） from regenerating liver tissue by in situ collagenase perfusion and counterflow elutriation, to determine potential cellular sources of these angiogenic factors after hepatectomy. Proliferation and apoptosis of SECs were also evaluated by proliferating cell nuclear antigen （PCNA） staining and the terminal deoxynucleotidyl transferase d-uridine triphosphate nick end labeling （TUNEL） assay, respectively. RESULTS： VEGF mRNA expression increased with a peak at 72 h after hepatectomy, decreasing thereafter. The expression of Ang-1 mRNA was present at detectable levels before hepatectomy and increased slowly with a peak at 96 h. Meanwhile, Ang-2 mRNA was hardly detected before hepatectomy, but was remarkably induced at 120 and 144 h. In isolated cells, VEGF mRNA expression was found mainly in the hepatocyte fraction. Meanwhile, mRNA for Ang-1 and Ang-2 was found in the SEC and HSC fractions, but was more prominent in the latter. The PCNA labeling index of SECs increased slowly, reaching a peak at 72 h, whereas apoptotic SECs were detected between 120 h and 144 h. CONCLUSION： Ang-Tie system, together with VEGF, plays a critical role in regulating balance between SEC proliferation and apoptosis during sinusoidal regeneration after hepatectomy. However, the VEGF system plays a more important role in the early phase of sinusoidal regeneration than angiopoietin/Tie system.

Preventative effects of a probiotic, Lactobacillus salivarius ssp. salivarius, in the TNBS model of rat colitis

AIM： To investigate the intestinal anti-inflammatory effect and mechanism of a probiotic Lactobacillus salivarius ssp. salivariusCECT5713 in the TNBS model of rat colitis. METHODS： Female Wistar rats （180-200 g） were used in this study. A group of rats were administered orally the probiotic L. salivarius ssp. salivarius （5 × 10^8 CFU suspended in 0.5 mL of skimmed milk） daily for 3 wk. Two additional groups were used for reference, a non-colitic and a control colitic without probiotic treatment, which received orally the vehicle used to administer the probiotic. Two weeks after starting the experiment, the rats were rendered colitic by intracolonic administration of 10 mg of TNBS dissolved in 0.25 mL of 500 mL/L ethanol. One week after colitis induction, all animals were killed and colonic damage was evaluated both histologically and biochemically. The biochemical studies performed in colonic homogenates include determination of myeloperoxidase （MPO） activity, glutathione （GSH） content, leukotriene B4 （LTB4） and tumor necrosis factor α （TNF-α） levels, as well as inducible nitric oxide synthase （iNOS） expression. In addition, the luminal contents obtained from colonic samples were used for microbiological studies, in order to determine Lactobacilli and Bifidobacteria counts. RESULTS： Treatment of colitic rats with L. salivarius ssp. salivarius resulted in amelioration of the inflammatory response in colitic rats, when compared with the corresponding control group without probiotic treatment. This antiinflammatory effect was evidenced macroscopically by a significant reduction in the extent of colonic necrosis and/or inflammation induced by the administration of TNBS/ethanol （2.3±0.4 cm vs3.4±0.3 cm in control group, P〈0.01） and histologically by improvement of the colonic architecture associated with a reduction in the neutrophil infiltrate in comparison with non-treated colitic rats. The latter was confirmed biochemically by a significant reduction of colonic MPO activity （105.3±26.0 U/g vs 180.6±21.9 U/g, P〈0.05）, a marker of neutrophil infiltration. The beneficial effect was associated with an increase of the colonic GSH content （1 252±42 nmol/g vs i 087±51 nmol/g, P〈0.05）, which is depleted in colitic rats, as a consequence of the oxidative stress induced by the inflammatory process. In addition, the treatment of colitic rats with L. salivarius resulted in a significant reduction of colonic TNF-（~ levels （509.4±68.2 pg/g vs782.9±60.1 pg/g, P〈0.01） and in a lower colonic iNOS expression, when compared to TNBS control animals without probiotic administration. Finally, treated colitic rats showed higher counts of Lactobacilli species in colonic contents than control colitic rats, whereas no differences were observed in Bifidobacteria counts. CONCLUSION： Administration of the probiotic L. salivarius ssp. salivarius CECT5713 facilitates the recovery of the inflamed tissue in the TNBS model of rat colitis, an effect associated with amelioration of the production of some of the mediators involved in the inflammatory response in the intestine, such as cytokines, including TNF-α and NO. This beneficial effect could be ascribed to its effect on the altered immune response that occurs in this inflammatory condition.

Thiazolidinedione treatment inhibits bile duct proliferation and fibrosis in a rat model of chronic cholestasis

AIM： To investigate the effects of troglitazone （TGZ）, an anti-diabetic drug which activates peroxisome proliferatoractivated receptor-y （PPAR-y）, for liver tissue repair, and the development of ductular reaction, following common bile duct ligation （BDL） in rats. METHODS： Rats were supplemented with TGZ （0.2% w/w in the pelleted food） for i wk before BDL or sham operation. Animals were killed at 1, 2, or 4 wk after surgery. RESULTS： The development of liver fibrosis was reduced in rats receiving TGZ, as indicated by significant decreases of procollagen type I gene expression and liver hydroxyproline levels. Accumulation of a-smooth-muscle actin （SMA）-expressing cells surrounding newly formed bile ducts following BDL, as well as total hepatic levels of SMA were partially inhibited by TGZ treatment, indicating the presence of a reduced number and/or activation of hepatic stellate cells （HSC） and myofibroblasts. Development of the ductular reaction was inhibited by TGZ, as indicated by histochemical evaluation and hepatic activity of γ-glutamyltransferase （GGT）. CONCLUSION： Treatment with thiazolidinedione reduces ductular proliferation and fibrosis in a model of chronic cholestasis, and suggests that limiting cholangiocyte proliferation may contribute to the lower development of scarring in this system.

Effects of dietary supplementation with vitamin E and selenium on rat hepatic stellate cell apoptosis

AIM： To evaluate the effects of dietary supplementation with vitamin E and selenium on proliferation and apoptosis of hepatic stellate cells （HSCs）, in acute liver injury induced by CCI4, and to explore their role in the recovery from hepatic fibrosis phase. METHODS： An acute liver damage model of rats was established by intraperitoneal injection of carbon tetrachloride （0.3 ml/100 g body weight） twice a week, then the rats were killed at 6, 24, 48, and 72 h after the first and third injection, respectively. A liver fibrosis model was established by the same injection for 8 wk. Then three rats were killed at 3, 7, 14, and 28 d after the last injection, respectively. The rats from the intervention group were fed with chow supplemented with vitamin E （250 mg/kg） and selenium （0.2 mg/kg）, and the rats in the normal control group and pathological group were given standard chow. Livers were harvested and stained with hematoxylin and eosin, Sirius red. Activated HSCs were determined by s-smooth muscle actin immunohistochemistry staining. Apoptotic HSCs were determined by dual staining with the terminal deoxynucleotidyl transferase UTP nick end labeling （TUNEL） and α-smooth muscle actin immunohistochemistry. Serum alanine aminotransferase and aspartate aminotransferase were also analyzed. RESULTS： In the acute liver damage model, the degree of liver injury was more serious in the pathological group than in the intervention group. At each time point, the number of activated HSCs was less in the intervention group than in the pathological group, while the number of apoptotic HSCs was more in the intervention group than in the pathological group. In the liver fibrosis model, the degree of liver fibrosis was more serious in the pathological group than in the intervention group. At each time point, the number of activated HSCs was less in the intervention group than in the pathological group, and the number of apoptotic HSCs was more in the intervention group than in the pathological group. CONCLUSION： Vitamin E and selenium supplementation at the given level can inhibit CCI4-induced activation and proliferation of HSCs and promote the apoptosis of activated HSCs in acute damage phase. Vitamin E and selenium can also effectively decrease the degree of hepatic fibrosis and promote the recovery process.

Effect of early administration of exogenous basic fibroblast growth factor on acute edematous pancreatitis in rats

AIM： To observe the therapeutic effect of early administration of exogenous Basic fibroblast growth factor （bFGF） on acute edematous pancreatitis （AEP） in rats. METHODS： Thirty male Sprague-Dawley rats were randomly divided into three （n = 10）： normal control group （group Ⅰ）, AEP group （group Ⅱ） and AEP with bFGF treatment group （group Ⅲ）. AEP was induced by subcutaneous injection of cerulein （5.5 μg/kg and 7.5 μg/kg） at 1 h interval into rats of groups Ⅱ and Ⅲ. Three hours after induction of AEP, 100 μg/kg bFGF was administrated intraperitoneally for 1h to group Ⅲ rats. For test of DNA synthesis in acinar cells, 5-bromo-2＇-deoxyuridine （BrdU） labeling solution was intraperitoneally injected into the rats of groups Ⅱ and Ⅲ 24 h after bFGF treatment. The changes in serum amylase, lipase, pancreatic tissue wet/dry ratio were detected. RESULTS： In bFGF treatment group, there was a significant decrease in the volume of serum amylase, lipase and the pancreatic wet/dry weight ratio（1383.0 ± 94.6 U/L, 194.0 ± 43.6 U/L, 4.32 ± 0.32） compared to AEP group （3464 ± 223,7 U/L, 456 ±68,7 U/L, 6.89 ± 0,47） （P 〈 0.01）, and no significant difference was found between bFGF treatment and control group （1289 ± 94.0 U/L, 171 ± 23.4 U/L, 4.12 ± 0.26, P 〉 0.05）. The inflammatory changes such as interstitial edema, polymorphonuclear neutrophUs （PMNs） and vacuolization were significantly ameliorated compared to AEP group （P 〈 0.01）. A small number of BrdU-labeled nuclei were observed in acinar cells of AEP rats （1.8 ± 0.3 nuclei/microscopic field, n = 10） while diffuse BrdU-labeled nuclei were found in bFGF-treated rats （18.9 ± 1.4 nuclei/microscopic field, n = 10） （P 〈 0.01）. Immunohistochemical study showed increased DNA synthesis in pancreatic acinar cells. CONCLUSION： Early administration of exogenous bFGF has significant therapeutic effect on cerulein-induced acute edematous pancreatitis in rats. Its mechanism is related to the amelioration of inflammation and facilitation of pancreatic regeneration.

浅议“微信公众号+生物学小实验开发”的实践与应用

推进数字化教学、全面提升学生认知水平和学业成绩已成为初中生物学教师的广泛共识。借助微信公众号设计生物学小实验,既紧贴时代背景,又能实现培育学生综合素养的目标,具有极强的适用性和广阔的应用前景。

Effect of water restrictions on the physiological parameters,psychological behavior and brain c-Fos expression in rat

Objective In order to characterize the feature of stress response induced by stressor with both physical and psychological natures, the effect of water restriction performed in different experimental modes on the physiological parameters, psychological behavioral manifestations and brain c-Fos expressions were observed and compared. Methods 58 male Wistar rats were used and randomly divided into three experimental groups （n=18 for each） and a control group （n=4）. In control group, the rats were allowed to access drinking water freely at all experimental period. In the experimental groups the water supply to the rats was restricted. In timed water supply （TW） group, the water was supplied twice a day, 10 min for each in fixed hours every day. In empty bottle-served （EB） and water-restricted （WR） groups, the water was served only once a day for 10 min, either in the early morning or evening, and in the other time point scheduled for water supply only an empty bottle without water was provided in the EB group and nothing was given in the WR group. The quantities of drank water and eaten food, weight-gaining, and behavior score were observed every day. The serum level of corticosterone was assayed and the rats were sacrificed with fixative perfusion of 3 d, 7 d or 14 d respectively, following water restriction （n=6 for each time point in each group）. The brain c-Fos expressions were examined with immunohistochemistry. Results The slowing down of weight-gaining, rise of serum corticosterone level, occurrence of psychological behavioral manifestations of unpeaceful restlessness such as exploring and attacking, enhance of c-Fos expression in the subfomical organ （SFO）, median preoptic nucleus （MnPO）, area postrema （AP）, hypothalamic paraventricular nucleus （PVN）, supraoptic nucleus （SON）, medial （MeA） and central （CeA） amygdaloid nucleus and ventrolateral septum （LSV） were noticed in both EB and WR groups, except the nucleus of solitary tract （NTS） in which the Fos expression was decreased. The changes of Fos expression in most of nuclei in EB group began at day 3, at least persisted till day 7, and backed down at day 14. While in WR group, similar changes started at day 7 and reached its peak at day 14. In TW group, only the concentration of corticosterone at day 7 was slightly increased and the rest indexes observed were unchanged. Conclusion The results indicate that water restriction induces physical as well as psychological stress responses. And the water restrictions experimentally executed in different modes result in different manifestations of behavioral response and brain immediately early gene expression in discrete brain nuclei/regions.

To Complete Mourning by Becoming Specters＂ The Mutualized Coming-to-Be in The Red Violin

This essay enacts a dialogue between Francois Girard＇s film The Red Violin （1998） and Jacques Derrida＇s contemplations on ＂memory,＂ ＂spectrality＂ and ＂the work of mourning＂ to envision the possibility of opening a hopeful condition of being for those who suffer from loss. In The Red Violin, Girard＇s cinematic experiments apply techniques of montage and of repetitive musical theme, practicing intertextuality of non-chronological stories by paralleling various memories of each individual character, blurring the biological and metaphorical boundaries between the living and non-living, and highlighting the fateful interrelations among time, space and different characters＇ life experiences. In this vein, the memories and beings of both the living and the dead are tightly woven together while reproduced--or further, relived--in temporal, spatial and trans-individual dynamics. Reversing the negative imaginaries of loss and death, both Derrida and The Red Violin agree with a messianic work of mourning by exploring the powerful potentiality of spectrality that manifests a way to mutualize the subject/ other, the living/non-living, into a promised being, thus gesturing towards an infinite future.

Biomass Vapogasification in Fluidized Bed： Modelling of Char Population Balance and Experimental Validation

The article presents a population balance model by mass developed for studying char gasification by steam occuring in a fluidized bed. The model has been validated by comparison with existing theoretical and experimental cases. Its main goal is to have a better understanding on particles size distribution behaviour during operation of the fluidized bed, and in particular to be applied on the case of Fast Internally Circulating Fluidized Beds for char gasification. Results have shown that the initial properties of the fluidized bed particles （bed and size distribution） are almost not involved in the steady state obtained in continous operation, which is excusively dependent on the properties of the fed particles flow rate and size distribution, the withdrawal flow rate and the reaction properties. Morevoer, it has been proven that the steady state fluidized bed mass and size distribution may be theroretically controlled by an adequate choice of feeding and withdrawal flow rates.