基于语篇的小学英语语音教学实践——以PEP《英语》中的Let’s spell板块为例

《义务教育英语课程标准(2022年版)》指出:教学设计与实施要以主题为引领,以语篇为依托。这对Let’s spell板块的教学提出了新的挑战。为了探索基于语篇的语音教学新方式,教师“立足教材内外资源,寻找合适的语篇;依托恰当的语篇,创设层级活动”,帮助学生掌握并运用发音规律,形成语音意识,提升综合素养。

《英语》(人教版)小学三上Unit 4 Pets Let’s Spell教学案例及点评

字母是组成词汇的要素,词汇是构成句子的要素,句子是构成篇章的要素,因而字母和字母组合的发音会直接影响学生词汇和语篇的学习,语音教学的重要性也因此不言而喻。但是由于种种原因,小学英语语音教学研究受到的关注远不如词汇教学、句式教学和阅读教学等。传统的语音教学一般直接告知学生字母或字母组合的发音,之后进行机械操练,很少让学生自主归纳并感知发音。

运用多种策略 落实语音教学——以修订版PEP教材Let’s Spell板块教学为例

《义务教育英语课程标准(2011年版)》(以下简称《2011年版课标》)指出:"语音教学是语言教学的重要内容之一。自然规范的语音、语调将为有效的口语交际打下良好的基础。"新修订的《义务教育教科书·英语(PEP)(三年级起点)》教材(以下简称"教材")每一册都安排了相应的语音教学板块,凸显了语音教学的重要性,也促进了语音教学的实践探索。下面,笔者就本教材语音教学,结合自身课堂实践案例谈几点策略。

DVB-S中即时通信语音流量识别技术研究

为了对DVB-S中即时通信的语音流量进行监控,分析了3种主流即时通信软件MSN,QQ和ICQ的通信协议,重点研究了语音会话连接过程中的消息特征和语音数据包特征,提出了一种基于协议流程与深度包检测的即时通信语音流量识别算法,实现了对上述3种即时通信的语音流量识别。

梦幻叙事之精神探秘——以张鲜明《信使的咒语》等为例

张鲜明《信使的咒语》以99个梦幻场景,打开了一个神秘的潜意识世界。梦中的“我”是作家主体分裂出的另一个不戴社会面具的人,“我”经历的惶然、被追赶的惊悚等一系列戏剧化场景——危险而美妙的游戏,拓展了人的意识边界与语言叙述的向度。张鲜明梦幻叙事背后的文化谱系及文本生成机制源自其独特的文化基因——豫西南豫鄂山区地缘文化的气脉、父母的遗传,以及他的语言的自觉。他的梦幻叙事具有独特的文学原创性。

Norepinephrine transporter (NET) is expressed in cardiac sympathetic ganglia of adult rat

The sympathetic nervous system plays a cardinal role in regulating cardiac function through releasing the neurotransmitter norepinephrine (NE). In comparison with central nervous system, the molecular mechanism of NE uptake in myocardium is not clear. In present study, we proved that in rat the CNS type of NE transporter (NET) was also expressed in middle cervical-stellate ganglion complex (MC-SG complex) which is considered to control the activity of heart, but not expressed in myocardium. The results also showed that NET expression level in right ganglion was significantly higher than in the left, rendering the greater capacity of NE uptake in right ventricle, a fact which may contribute to the maintenance of right ventricular function under pathologic state.

Identification of differentially expressed genes in normal mucosa,adenoma and adenocarcinoma of colon by SSH

AIM: To construct subtracted cDNA libraries and further identify differentially expressed genes that are related to the development of colorectal carcinoma(CRC). METHODS: Suppression subtractive hybridization(SSH) was done on cDNAs of normal mucosa, adenoma and adenocarcinoma tissues from the same patient. Three subtracted cDNA libraries were constructed and then hybridized with forward and backward subtracted probes for differential screening. Positive clones from each subtracted cDNA library were selected for sequencing and BLAST analysis. Finally, virtual Northern Blot confirmed such differential expression. RESULTS: By this way, there were about 3-4 X 10(2) clones identified in each subtracted cDNA library, in which about 85% positive clones were differentially screened. Sequencing and BLAST homology search revealed some clones containing sequences of known gene fragments and several possibly novel genes showing few or no sequence homologies with any known sequences in the database. CONCLUSION: All results confirmed the effectiveness and sensitivity of SSH. The differentially expressed genes during the development of CRC can be used to shed light on the pathogenesis of CRC and be useful genetic markers for early diagnosis and therapy.

Transplantation of human hepatocytes into tolerized genetically immunocompetent rats

AIM: To determine whether normal genetically immunocompetent rodent hosts could be manipulated to accept human hepatocyte transplants with long term survival without immunosuppression. METHODS: Tolerance towards human hepatocytes was established by injection of primary human hepatocytes or Huh7 human hepatoma cells into the peritoneal cavities of fetal rats. Corresponding cells were subsequently transplanted into newborn rats via intrasplenic injection within 24h after birth. RESULTS: Mixed lymphocyte assays showed that spleen cells from non-tolerized rats were stimulated to proliferate when exposed to human hepatocytes, while cells from tolerized rats were not. Injections made between 15 d and 17 d of gestation produced optimal tolerization. Transplanted human hepatocytes in rat livers were visualized by immunohistochemical staining of human albumin. By dot blotting of genomic DNA in livers of tolerized rats 16 weeks after hepatocyte transplantation, it was found that approximately 2.5 X 10(5) human hepatocytes survived per rat liver. Human albumin mRNA was detected in rat livers by RT-PCR for 15 wk, and human albumin protein was also detectable in rat serum. CONCLUSION: Tolerization of an immuno-competent rat can permit transplantation, and survival of functional human hepatocytes.

Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. METHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500mL.L(-1), i.g.) was used to induce gastric mucosa damage. RESULTS: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL.L(-1) ethanol challenge, the ulcer area found in the rats with 7d sleep deprivation (19.15 +/- 4.2)mm(2) was significantly lower (P【0.01) than the corresponding control (53.7 +/- 8.1) mm(2). CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.

Effects of hypoxia,hyperoxia on the regulation of expression and activity of matrix metalloproteinase-2 in hepatic stellate cells

AIM: To study the effects of hypoxia, hyperoxia on the regulation of expression and activity of matrix metalloproteinase-2 (MMP-2) in hepatic stellate cells (HSC). METHODS: The expressions of MMP-2, tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) and membrane type matrix metalloproteinase-1 (MT1-MMP) in cultured rat HSC were detected by immunocytochemistry (ICC) and in situ hybridization (ISH). The contents of MMP-2 and TIMP-2 in culture supernatant were detected with ELISA and the activity of MMP-2 in supernatant was revealed by zymography. RESULTS: In the situation of hypoxia for 12h, the expression of MMP-2 protein was enhanced (hypoxia group positive indexes: 5.7 +/- 2.0, n=10; control: 3.2 +/- 1.0, n = 7; P【0.05), while TIMP-2 protein was decreased in HSC (hypoxia group positive indexes: 2.5 +/- 0.7, n = 10; control: 3.6 +/- 1.0, n = 7; P 【 0.05), and the activity (total A) of MMP-2 in supernatant declined obviously (hypoxia group: 7.334 +/- 1.922, n = 9; control: 17.277 +/- 7.424, n = 11; P 【 0.01). Compared the varied duration of hypoxia, the changes of expressions including mRNA and protein level as well as activity of MMP-2 were most notable in 6h group. The highest value(A(hypoxia)-A(control)) of the protein and the most intense signal of mRNA were in the period of hypoxia for 6h, along with the lowest activity of MMP-2. In the situation of hyperoxia for 12h, the contents (A(450)) of MMP-2 and TIMP-2 in supernatant were both higher than those in the control, especially the TIMP-2 (hyperoxia group: 0.0499 +/- 0.0144, n = 16; control: 0.0219 +/- 0.0098, n = 14; P 【 0.01), and so was the activity of MMP-2 (hyperoxia group: 5.252 +/- 0.771, n = 14; control: 4.304 +/- 1.083, n = 12; P 【 0.05), and the expression of MT1-MMP was increased. CONCLUSION: HSC is sensitive to the oxygen, hypoxia enhances the expression of MMP-2 and the effect is more marked at the early stage; hyperoxia mainly raises the activity of MMP-2.

Screen for stage-specific expression genes between tail bud stage and heartbeat beginning stage in embryogenesis of gynogenetic silver crucian carp

A systemic study was initiated to identify stage-specific expression genes in fish embryogenesis by using suppression subtractive hybridization (SSH) technique. In this study, we presented a preliminary result on screen for stage-specific expression genes between tail bud stage (TBS) and heartbeat beginning stage (HBS) in gynogenetic silver crucian carp (Carassius auratus gibelio). Two SSH plasmid libraries specific for TBS embryos and HBS embryos were constructed, and stage-specific expression genes were screened between the two stages. 1963 TBS positive clones and 2466 HBS positive clones were sampled to PCR amplification, and 1373 TBS and 1809 HBS PCR positive clones were selected to carry out dot blots. 169 TBS dot blot positive clones and 272 HBS dot blot positive clones were sequenced. Searching GenBank by using these nucleotide sequences indicated that most of the TBS dot blot positive clones could not be found homologous sequences in the database, while known genes were mainly detected from HBS dot blot positive clones. Of the 79 known genes, 20 were enzymes or kinases involved in important metabolism of embryonic development. Moreover, specific expressions of partial genes were further confirmed by virtual northern blots. This study is the first step for making a large attempt to study temporal and spatial control of gene expression in the gynogenetic fish embryogenesis.

Inhibiting effect of antisense oligonucleotides phosphorthioate on gene expression of TIMP-1 in rat liver fibrosis

AIM: To observe the inhibition of antisense oligonucleotides (asON) phosphorthioate to the tissue inhibitors metalloproteinase-1 (TIMP-1) gene and protein expression in the liver tissue of immunologically induced hepatic fibrosis rats. The possibility of reversing hepatic fibrosis through gene therapy was observed. METHODS: Human serum albumin (HSA) was used to attack rats, as hepatic fibrosis model, in which asONs were used to block the gene and protein expressing TIMP-1. According to the analysis of modulator, structure protein, coding series of TIMP-1 genome, we designed four different asONs. These asONs were injected into the hepatic fibrosis models through coccygeal vein. The results was observed by RT-PCR for measuring TIMP-1 mRNA expression, immunohistochemistry and in situ hybridization for collagen I, II, special staining of collagen fiber, and electron microscopic examination. RESULTS: Hepatic fibrosis could last within 363 days in our modified model. The expressing level of TIMP-1 was high during hepatic fibrosis process. It has been proved by the immunohistochemical and the electron microscopic examination that the asON phosphorthioate of TIMP-1 could exactly express in vivo. The effect of colchicine was demonstrated to inhibit the expressing level of mRNA and the content of collagen I, III in the liver of experimental hepatic fibrosis rats. However, the electron microscopy research and the pathologic grading of hepatic fibrosis showed that there was no significant difference between the treatment group and the model group (P】 0.05). CONCLUSION: The experimental rat model of hepatic fibrosis is one of the preferable models to estimate the curative effect of anti-hepatic fibrosis drugs. The asON phosphorthioate of TIMP-1 could block the gene and protein expression of TIMP-1 in the liver of experimental hepatic fibrosis rats at the mRNA level. It is possible to reverse hepatic fibrosis, and it is expected to study a new drug of antihepatic fibrosis on the genetic level. Colchicine has very limited therapeutic effect on hepatic fibrosis, furthermore, its toxicity and side effects are obvious.

Expression of lipopolysaccharide binding protein and its receptor CD14 in experimental alcoholic liver disease

AIM: To evaluate the relationship between the expression of lipopolysaccharides (LPS) binding protein (LBP) and CD14 mRNA and the severity of liver injury in alcohol-fed rats. METHODS: Twenty Wistar rats were divided into two groups:ethanol-fed group (group E) and control group (group C). Group E was fed with ethanol(5-12 g x kg(-1) x d(-1)) and group C received dextrose instead of ethanol. Rats of the two groups were sacrificed at 4 weeks and 8 weeks. Levels of endotoxin and alanine transaminase (ALT) in blood were measured, and liver pathology was observed under light and electronic microscopy. Expressions of LBP and CD14 mRNA in liver tissues were determined by RT-PCR analysis. RESULTS: Plasma endotoxin levels were increased more significantly in group E(129+/-21) ng x L(-1) and (187+/-35) ng x L(-1) at 4 and 8 wk than in control rats(48+/-9) ng x L(-1) and (53+/-11) ng x L(-1), respectively (P【0.05). Mean values of plasma ALT levels were (1867+/-250) nkat x L(-1) and (2450+/-367) nkat x L(-1) in Group E. The values were increased more dramatically in ethanol-fed rats than in Group C after 4 and 8 weeks. In liver section from ethanol-fed rats, there were marked pathological changes (steatosis, cell infiltration and necrosis). In ethanol-fed rats, ethanol administration led to a significant increase in LBP and CD14 mRNA levels compared with the control group (P【0.05). CONCLUSION: Ethanol administration led to a significant increase in endotoxin levels in serum and LBP and CD14 mRNA expressions in liver tissues. The increase of LBP and CD14 mRNA expression might wake the liver more sensitive to endotoxin and liver injury.

The role of endotoxin,TNF-α,and IL-6 in inducing the state of growth hormone insensitivity

AIM: Critical illnesses such as sepsis, trauma, and burns cause a growth hormone insensitivity, which leads to an increased negative nitrogen balance. Endotoxin is generously released into blood under these conditions and stimulates the production of proinflammatory cytokines such as TNF-alpha, IL-6, and IL-1, which may play a very important role in inducing the growth hormone insensitivity. The objective of this current study was to investigate the role of endotoxin, TNF-alpha and IL-6 in inducing the growth hormone insensitivity at the receptor and post-receptor levels. METHODS: Spague-Dawley rats were injected with endotoxin, TNF-alpha, and IL-6, respectively and part of rats injected with endotoxin was treated with exogenous somatotropin simultaneously. All rats were killed at different time points. The expression of IGF-I, GHR, SOCS-3 and beta-actin mRNA in the liver was detected by RT-PCR and the GH levels were measured by radioimmunoassay, the levels of TNF-alpha and IL-6 were detected by ELISA. RESULTS: There was no significant difference in serous GH levels between experimental group and control rats after endotoxin injection, however, liver IGF-I mRNA expression had been obviously down-regulated in endotoxemic rats. Liver GHR mRNA expression also had a predominant down-regulation after endotoxin injection. The lowest regulation of liver IGF-I mRNA expression occurred at 12h after LPS injection, being decreased by 53% compared with control rats. For GHR mRNA expression, the lowest expression occurred at 8h and had a 81% decrease. Although SOCS-3 mRNA was weakly expressed in control rats, it was strongly up-regulated after LPS injection and had a 7.84 times increase compared with control rats. Exogenous GH could enhance IGF-I mRNA expression in control rats, but it did fail to prevent the decline in IGF-I mRNA expression in endotoxemic rats. Endotoxin stimulated the production of TNF-alpha and IL-6, and the elevated IL-6 levels was shown a positive correlation with increased SOCS-3 mRNA expression. The liver GHR mRNA expression was obviously down-regulated after TNF-alpha iv injection and had a 40% decrease at 8h, but the liver SOCS-3 mRNA expression was the 4.94 times up-regulation occurred at 40 min after IL-6 injection. CONCLUSION: The growth hormone insensitivity could be induced by LPS injection, which was associated with down-regulated GHR mRNA expression at receptor level and with up-regulated SOCS-3 mRNA expression at post-receptor level. The in vivo biological activities of LPS were mediated by TNF-alpha and IL-6 indirectly, and TNF-alpha and IL-6 may exert their effects on the receptor and post-receptor levels respectively.

Expressions of ICAM-1 and its mRNA in sera and tissues of patients with hepatocellular carcinoma

INTRODUCTIONThe increased expression of ICAM-1 on a widerange of cells and in the sera of patients withmalignancies, chronic liver diseases andinflammation diseases has been described since thelate 1980s[1-22]. Recently rapid progress in studieson expression of ICAM-1 in patients withhepatocellular carcinoma ( HCC ) have beenachieved, including clinical and experimentalresearches[23-31].

Adhesion molecule and proinflammatory cytokine gene expression in hepatic sinusoidal endothelial cells following cecal ligation and puncture

INTRODUCTIONMultiple organ dysfunction syndrome (MODS) isthought to be a frequent consequence of sepsis[1-3].Despite substantial advances in our knowledge and understanding of the basic pathophysiologic mechanisms[4-7], in critically ill patients infections and sepsis are still associated with a high mortality[8,9].

Effect of 5-Aza-2'-deoxycytidine on the P16 tumor suppressor gene in hepatocellular carcinoma cell line HepG2

INTRODUCTIONHepatocellular carcinoma (HCC) is one of the mostcommon human malignancies worldwide[1,2], and isclosely associated with infection of HBV and HCVand contamination of aflatoxin B1[3-6]. Althoughthe molecular mechanisms of hepatocarcinogenesisremain poorly understood, an increasing number ofgenetic abnormalities have been recognized[7-10],for example, the p16 gene[11,12] the p53gene[13-18], the E-cadherin gene[19], and the c-mycgene[20].