Development of High-speed Rectangle Burner Used in Baked Aluminum Reduction Cells

Bake out of Aluminum reduction cells will affect the normal production and the ultimate life of reduction cell directly. The method of thermal bake out is a key of novel technology which possesses such advantages as well distributed temperature, easy control for the speed of heating up, fully baking for the joint and ramming paste of the edge. The design of the burner is a key technology of thermal bake out. A new high speed rectangle burner has been developed based on the experiment, and the structure of this burner has also been optimized. The new burner an fire easily, burn stably and fully, and has high ratio of load adjustment, and low noise, etc.. It can meet the needs of thermal bake out reduction cells. Its development can provide the technological guarantee for the use of thermal bake out Aluminum reduction cells.     

Bactericidal activity of cecropin B and cecropin P1 expressed in fish cells (CHSE-214): application in controlling fish bacterial pathogens

Cecropins are a group of antimicrobial peptides which have bactericidal activity against a broad range of bacteria. To date, the cecropins used in a variety of studies were either purified from their natural source or obtained by chemical synthesis. The present study was conducted to test whether bactericidally active cecropins could be expressed in a fish cell line. For this purpose, Chinook salmon embryo cells (CHSE-214) were transfected with cecropin transgene constructs: Hyalophora cecropia preprocecropin B, procecropin B, cecropin B, and porcine P₁ cecropin. From the transfected cells, single cell clones were selected and screened for the presence of cecropin gene constructs by PCR amplification. The expression of the cecropin transgene in the PCR positive clones was determined by RT-PCR reaction. Southern blot hybridization results showed that the cecropin gene constructs were integrated into the genome in a multiple integration pattern. Bactericidal activity of the cecropins, synthesized from transgene constructs, was detected using inhibition zone assay for fish pathogenic bacteria: Aeromonas hydrophila, Pseudomonas fluorescens, and Vibrio anguillarum. Cecropin antimicrobial peptides produced in CHSE-214 cells possess bactericidal activity against these three fish pathogenic bacteria.     

胡杨悬浮细胞的生长及液泡膜微囊的制备

改进了胡杨细胞悬浮培养体系，细胞得率提高了3倍多。做出了胡杨悬浮细胞：的生长曲线，以培养12～15d为宜。摸索了胡杨细胞破壁技术，使用了研磨、超声、捣碎、French Press法。从蛋白产率、v．H^ ATPaSe活力、反应潜势三个方面考虑选用捣碎法，结合差速离心和蔗糖密度梯度分离纯化液泡膜微囊，完善了从胡杨细胞分离纯化液泡膜微囊的试验流程，从而使液泡膜H^ ATPase的研究成为可能。     

番茄花粉母细胞减数分裂的初步观察

通过对番茄花粉母细胞减数分裂全过程的观察,指出了花粉发育的各阶段与花蕾外部形态的相关性以及减数分裂昼夜连续的规律性,比较了小孢子发育的步调.同时,还摸到了减数分裂染色制片的一般方法,并摄制了一套显微照片.     

兔瘟快速诊断的试验研究

使用醛化人“O”型红细胞和白瓷板进行血凝(HA)和血凝抑制(HI)试验诊断兔瘟,1～2分钟即可判定结果,反应时间比常规法缩短60倍。具有快速定性、定量检测的特点。同时该法特异、快速、简易、经济,是一种易于在基层推广应用的新方法。     

Advanced glycation end products induce apoptosis of human ovarian granulosa COV434 cells and up-regulate pro-inflammatory cytokine HMGB1 autocrine

AIM:To study whether advanced glycation end products (AGEs) induce the apoptosis of human ovarian granulosa COV434 cells, and to explore the possible mechanism. METHODS:Human ovarian granulosa COV434 cells were treated with AGEs at different concentrations. Flow cytometry was used to observe the apoptotic rate. The protein levels of caspase-3 and cleaved caspase-3 were determined by Western blot. The release of high mobility group box 1 protein (HMGB1) in the culture supernatant was measured by ELISA. RESULTS:Compared with control group, early apoptotic rate and late apoptotic rate in 100 mg/L AGEs group and 200 mg/L AGEs group were significantly increased (P<0.05). No obvious difference of caspase-3 protein level in each group was observed, while the protein levels of cleaved caspase-3 in 100 mg/L AGEs group and 200 mg/L AGEs group were significantly increased compared with control group (P<0.05). In addition, compared with control group, pro-inflammatory factor HMGB1 in the culture medium in 100 mg/L AGEs group and 200 mg/L AGEs group was significantly increased. CONCLUSION:The apoptosis of human ovarian granulosa COV434 cells induced by AGEs may be related to pro-inflammatory reaction.     

Protective effect of paeoniflorin on nerve cells in APP/PS1 mice and its mechanism

AIM: To investigate the therapeutic and preventive effects of paeoniflorin (PF) on APP/PS1 mice, and to explore the possible mechanism. METHODS: Fifteen male 5-month-old APP/PS1 non-dominant mice were chosen as normal control group, 15 male 5-month-old APP/PS1 double transgenic mice were used as model group, and 15 male 5-month-old APP/PS1 double transgenic mice treated with 5 mg/kg PF by intraperitoneal injection were allocated in administation group. The learning and memory ability of the mice in each group was detected by Morris water maze. The apoptosis was assessed by TUNEL fluorescence staining. The protein expression of PI3K, Akt, p-PI3K, p-Akt, caspase-3, caspase-9, Bcl-2 and Bax in cerebral cortex and hippocampus was detected by Western Blot. The protein expression levels and distribution of caspase-3 and caspase-9 were detected by immunohistochemistry. RESULTS: (1) Compared with normal control group, the learning and memory ability declined in APP/PS1 model group. Compared with APP/PS1 model group, PF obviously improve the ability of learning and memory in mice. (2) Compared with normal control group, the apoptosis of nerve cells in APP/PS1 model group significantly increased and distributed in wider areas, while that in PF group was reduced (P<0.05). (3) Compared with APP/PS1 model group, PF could significantly lower pro-apoptotic factors, caspase-3, caspase-9 and Bax (P<0.05), and increase the expression of anti-apoptotic factors, p-PI3K, p-Akt and Bcl-2 (P<0.05). CONCLUSION: PF can up-regulate the expression of Bcl-2 and down-regulate the expression levels of caspase-9, caspase-3 and Bax via the activation of PI3K/Akt pathway, thereby inhibiting the nerve cell apoptosis and protecting the nerve cells, so as to treat neurodegenerative diseases.     

Effect of miR-21 over-expression on proliferation,migration and diffe-rentiation of c-Kit+ cardiac stem cells

AIM: To explore the effect of microRNA (miR)-21 on proliferation, migration and differentiation abilities of c-Kit⁺ cardiac stem cells (CSCs). METHODS: c-Kit⁺ CSCs were cultured and selected by the methods of enzyme digestion and magnetic bead separation. miR-21 mimics (50 nmol/L) and mimics negative control (MNC) were transfected into c-Kit⁺ CSCs with Lipofectamine^® 2000. The cells was divided into 3 groups:control group:c-Kit⁺ CSCs without any pretreatment; MNC group:the cells were transfected with MNC for 48 h; mimics group:the cells were transfected with miR-21 mimics for 48 h. qPCR was used to assess the expression of miR-21 in each group. CCK-8 and EdU assays were used to determine the cell proliferation. qPCR and immunofluorescence were used to detect the differentiation in each group. Scratch assay was adopted to explore the migration ability of the cells. RESULTS: The expression of c-Kit in the c-Kit⁺ CSCs were 90.8%, with 0.6% of CD45 and 0.5% of CD34. A significant increase in miR-21 expression was observed when the cells were transfected with miR-21 mimics for 48 h (P<0.05). CCK-8 and EdU assays showed that miR-21 significantly increased cell proliferation as compared with MNC group and control group (P<0.05). No difference in the expression of Nkx2.5, CD31 and α-SMA at mRNA and protein levels was observed, and no difference of the migration ability in 3 groups of the c-Kit⁺ CSCs was found. CONCLUSION: Over-expression of miR-21 significantly promotes the proliferation of c-Kit⁺ CSCs, without any effect on the cell migration and differentiation.     

Effect of adoptive transfer of CD4+ T cells with miR-7 knockdown on acute liver injury in mice

AIM:To study the effect of adoptive transfer of CD4⁺ T cells with microRNA-7 (miR-7) knockdown (KD) on mouse acute liver injury model and to investigate its significance. METHODS:CD4⁺ CD62L⁺ T cells were purified from the spleen of normal wild-type (WT) mice and miR-7KD mice by magnetic bead sorting, and were stained with CFSE. These 2×10⁶ CFSE-labeling cells were injected into normal mice via tail vein, and then the mouse acute liver injury model was induced by intraperitoneal injection of 30 mg/kg concanavalin A. After 72 h, the appearance, weight and weight index of the liver were investigated. The pathological change of the liver tissues was observed by HE staining. Real-time PCR was used to examine the mRNA expression of Bax and P53. The expression levels of CD62L, interleukin-4 (IL-4) and interferon-γ (IFN-γ) in the CD4⁺ T cells were analyzed by flow cytometry. RESULTS:We found that the liver tissue became lighter, and the weight (P<0.01) and weight index (P<0.05) were changed significantly in miR-7KD mice compared with control group. Moreover, HE staining showed that the liver cell damage was increased in the liver of miR-7KD mice. Meanwhile, the expression levels of Bax and P53 were significantly increased in miR-7KD group (P<0.05). The percentage of CD62L in CD4⁺ T cells was significantly decreased (P<0.01) in miR-7KD mice, with high expression of IFN-γ (P<0.05) and low expression of IL-4 (P<0.01) in CD4⁺T cells. CONCLUSION:These findings suggest that miR-7 knockdown significantly promotes the pathology of CD4⁺ T cell-mediated acute liver injury, which provides a preliminary experimental basis for further exploration on the mechanism of acute liver injury occurrence.     

Effect of VDUP-1 on apoptosis of renal tubular epithelial cells induced by high glucose

AIM: To investigate the effect of vitamin D3 up-regulated protein 1 (VDUP-1) on apoptosis of renal tubular epithelial cells induced by high glucose and its mechanism. METHODS: Human renal proximal tubular epithelial cell line HK-2 was treated with high glucose. The mRNA and protein levels of VDUP-1 in HK-2 cells were detected by real-time PCR and Western blot. HK-2 cells were transfected with VDUP-1 small interfering RNA (siRNA). Real-time PCR and Western blot were used to detect the inhibitory effect. The HK-2 cells were treated with high glucose, and the change of VDUP-1 expression was detected. The apoptosis was analyzed by flow cytometry. The activities of caspase-3 and caspase-9 in the cells were measured. The tumor necrosis factor-α (TNF-α) content in the culture supernatant was examined by ELISA. The key proteins of Sonic hedgehog (Shh) signaling pathway, Patched 1 (Ptch1), Smoothened (Smo), zinc finger protein Gli2 and Shh, were determined by Western blot. The HK-2 cells were treated with exogenous Shh, and the levels of Ptch1, Smo and Gli2 were detected by Western blot. After the HK-2 cells with VDUP-1 silencing were treated with exogenous Shh and high glucose, the apoptosis was analyzed by flow cytometry, the activities of caspase-3 and caspase-9 in the cells were examined, and the TNF-α content in culture supernatant was measured by ELISA. RESULTS: High levels of VDUP-1 mRNA and protein were observed in the HK-2 cells treated with high glucose. The mRNA and protein levels of VDUP-1 were decreased in the HK-2 cells transfected with VDUP-1 siRNA(P<0.05). Compared with the normally cultured cells, the apoptotic rate of HK-2 cells was increased after high glucose treatment, and the activities of caspase-3 and caspase-9 and the content of TNF-α were also significantly increased (P<0.05). After down-regulation of VDUP-1 expression by siRNA transfection, the apoptotic rate of HK-2 cells decreased after high glucose treatment, and the activities of caspase-3 and caspase-9, and the content of TNF-α were also significantly decreased (P<0.05). The protein levels of Ptch1, Smo, Gli2 and Shh were decreased after high glucose culture, while down-regulation of VDUP-1 partly antagonized the effect of high glucose on the expression of Ptch1, Smo, Gli2 and Shh in the HK-2 cells. Exogenous Shh promoted the expression of Ptch1, Smo and Gli2, and inhibited the apoptosis of the HK-2 cells induced by high glucose. Exogenous Shh and down-regulation of VDUP-1 synergistically inhibited high glucose-induced apoptosis of the HK-2 cells. CONCLUSION: Down-regulation of VDUP-1 expression inhibits high glucose-induced apoptosis and release of TNF-α in renal tubular epithelial cells by activating Shh signaling pathway.