Variations of mitochondrial D-loop region plus downstream gene 1 2S rRNA-tRNA^(phe) and gastric carcinomas

AIM: To explore the instabilities, polymorphisms and other variations of mitochondrial D-loop region and downstream gene 12S rRNA-tRNAPhe in gastric cancers, and to study their relationship with gastric cancer.METHODS: Three adjacent regions (D-loop, tRNAphe and 12S rRNA) were detected for instabilities, polymorphisms and other variations via PCR amplification followed by direct DNA sequencing in 22 matched gastric cancerous tissues and para-cancerous normal tissues.RESULTS: PolyC or (CA)n instabilities were detected in 13/22(59.1％) gastric cancers and 9/22(40.9 ％) in the control (P＞0.05). There existed 2/12(16.7％) and 6/10(60％)alterations of 12S rR NA-tRNAphe in well differentiated gastric cancers and poorly differentiated ones, respectively(P0.05).Some new variations were found, among which np 318 and np 321 C-T transitions in D-loop region were two of the five bases for H-strand replication primer. Np 523 AC-deletion and np 527 C-T transition occurred at mtTF1 binding site (mtTFBS), which were associated with the transcription of downstream mitochondrial genome. Seven samples showed the np 16 182 polyC instabilities, five of which simultaneously showed np 16 189 T-C transitions.CONCLUSION: There is no statistic significance of instabilities and polymorphisms in mitochondrial D-loop region between gastric cancerous and para-cancerous normal tissues, which suggests that the instability might relate to heredity or be dependent on aging. There is asignificant correlation between differentiation degree of gastric cancer and variant frequencies of 12S rRNA-tRNAphe. The poorly differentiated gastric cancers are more prone to 12S rRNAtRNAphe variations, or gastric cancers with 12S rRNA-tRNAphe variations are more likely to be poorly differentiated, np 16189 T-C transition may be one of the important reasons for polyC instability in gastric cancer.

Martensitic Transformation of TiNi Shape Memory Alloy Fiber Reinforced Ni Matrix Composites

In this paper, a TiNi shape memory alloy fiber Ni matrix composite was fabricated by an electroplating method using TiNi alloy as the cathode and Ni as the anode. The constrained martensitic transformation behaviors of the TiNi alloy were studied by differential scanning calorimeter (DSC), and the results showed that two endothermic peaks appear on the DSC heating curves and the reverse transformation temperatures increase with increasing prestrain levels. Moreover, comparing to the free transformation, the temperature window of the constrained reverse transformation is widely expanded due to the influence of recovery stress.

The Syntax, Semantics and Pragmatics of 'lian…dou'

This article treats the chunk‘lian…dou’an a complex conjunction on the ground that the sentence that follows the sentence in which the chunk ‘lian…dou’occurs is often incomplete.The interpretation of the incomplete sentence,or the sentence fragment,calls for the restoration of the elided constituents by reconstruction.Moreover,the proposition expressed by the sentence fragment is entailed by the proposition expressed by the sentence in which the chunk‘lian…dou’occurs.Following Montague’s rule-to-rule hypothesis,we can take the entailment inherent in the whole construction as the syntactic reflex in its semantics.Since the entailment is obviously induced by the chunk‘lian…dou’,we treat it as a complex conjunction.Section 1 demonstrates that the sentence that follows the sentence in which the chunk‘lian…dou’occurs is not independent and in many ways is similar to the ‘ruguo…(name)’construction.Section 2 develops a scalar model based on Fillmore et al (1988)for the semantic interpretation of the construction,and gives an account of a variety of ‘lian…dou’sentences.Section 3 addresses the pragmatic aspect of the construction.It also argues that the first proposition conjoined by ‘lian…dou’itself has the function of simultaneously meeting the Gricean Maxims of Relevance,Quality and Quantity,thus making the verbalization of the second proposition unnecessary.

Decreased mtDNA Copy Number of Gastric Cancer： a New Tumor Marker？

OBJECTIVE To explore the relationship between mtDNA (mitochondrial DNA) and gastric cancer by comparing the difference of mtDNA copy number in gastric cancers and paracancerous tissues.METHODS The HV1 (hypervariable region) and HV2 of the mitochondrial Dloop region from 20 cases of gastric cancer and 20 paracancerous tissues were amplified by PCR with 13-actin serving as a quantitative standard marker. The products were separated by polyacrylamide gel electrophoresis (PAGE) and silver stained in order to compare the difference in mtDNA copy number between gastric cancers and paracancerous tissues. The mtDNA copy number was determined for gastric cancer shaving various pathological characteristics and the results compared with previous immunohistochemical staininq of the tumors,RESULTS There was a significantly quantitative difference in HV1, HV2 (standardized with β-actin) between gastric cancers and paracancerous tissues (P<0.01). The mtDNA copy number was associated with important enzymes in the nucleus such as AKP, cAMP-PDE and cGMP-PDE (P<0.05), but not associated with tumor histological type and invasive depth (P>0.05).CONCLUSION The occurrence of gastric cancer was closely associated with decreased mtDNA copy number, which may be a new tumor marker.

关于完善国家自然科学基金督办工作机制的思考

督办作为国家自然科学基金委员会办公室的一项重要工作职能,是保证习近平总书记重要指示批示精神,党中央、国务院重大决策部署,委领导指示批示,重要会议决定事项和新时代科学基金深化改革任务落实落地的重要举措。通过回顾2019年国家自然科学基金委员会督办工作,总结取得的具体成效,分析目前存在的主要问题,对进一步加强国家自然科学基金督办工作,完善督办工作机制提出工作建议。