分类： 生物学 >> 发育生物学 提交时间： 2016-10-27
摘要： 摘 要：目的 初步探索母亲是主要喂养人和母亲不是主要喂养人在儿童体型认知和喂养行为上的比较研究，为今后在家庭喂养环境中干预儿童肥胖提供借鉴。方法 在北京、西安、江苏和深圳等四个城市进行方便抽样选取8所幼儿园对儿童母亲进行随机抽样，共收回有效问卷456份。整个问卷采用母亲自我报告的调查方法。调查内容包括人口社会学特征、体型图表认知和儿童喂养问卷。结果 体重正常儿童的母亲能够正确认知子女的体重水平是前者（83.83%）大于后者（76.67%），超重儿童的母亲低估了子女的体重水平是前者（91.89%）大于后者（65.22%），肥胖儿童的母亲低估了子女的体重水平是前者（68.75%）大于后者（62.86%）。前者在填鸭式喂养行为上表现出了显著的差异性（F=6.096，P＜0.001），多重比较发现，低体重和正常体重儿童（t=3.247,P=0.001）、正常体重和肥胖儿童（t=-3.292,P＜0.001）之间存在显著性差异。在填鸭式喂养行为上前者在正确认知和低估（t=-2.779,P＜0.01）、正确认知和高估（t=-2.780,P＜0.01）中分别存在显著性差异。后者的认知偏差在母亲每月税后收入高水平和低水平之间存在显著性差异（t=2.772,P＜0.01）。结论 二者均存在认知偏差现象，而母亲不是主要喂养人时更容易在母亲每月税后收入低水平时出现认知偏差现象。但在超重和肥胖儿童母亲中二者均更存在体型认知低估现象。母亲是主要喂养人时更倾向于在低体重和肥胖儿童中采取填鸭式喂养行为，而其体型认知可能会影响其喂养行为。
分类： 物理学 >> 电磁学、光学、声学、传热、经典力学和流体动力学 提交时间： 2016-10-17
摘要： The fluctuations of the current and voltage of the quantized unit cell equivalent circuit in loss-less mesoscopic left-handed transmission lines (LH TL)are deduced by thermal field dynamics (TFD) theory. And the fluctuations dependent of negative refractive index (NRI) of mesoscopic LH TL is discussed further in thermal Fock state. The results indicate that the quantum fluctuations show linear increasing dependent of NRI, while the frequency within the microwave frequency band and thermal photons show destructive dependent of NRI at some temperature. When the unit cell equivalent circuit operates at the rising temperature, the NRI is decreasing. The results demonstrates that the lower frequency and temperature, little thermal photons are more conducive to NRI of the mesoscopic LH TL, which is significant for the miniaturizing applications of LH TL.
分类： 生物学 >> 分子生物学 分类： 生物学 >> 动物学 提交时间： 2016-10-06
摘要： In this study, we introduced a general framework to use PacBio full-length transcriptome sequencing for the investigation of the fundamental problems in mitochondrial biology, e.g. genome arrangement, heteroplasmy, RNA processing and the regulation of transcription or replication. As a result, we produced the first full-length human mitochondrial transcriptome from the MCF7 cell line based on the PacBio platform and characterized the human mitochondrial transcriptome with more comprehensive and accurate information. The most important finding is two novel genes hsa-MDL1 and hsa-MDL1AS, which are encoded by the mitochondrial D-loop regions. We propose hsa-MDL1 and hsa-MDL1AS, as the precursors of transcription initiation RNAs (tiRNAs), belong to a novel class of long non-coding RNAs (lnRNAs), which is named as long tiRNAs (ltiRNAs). Based on the mitochondrial RNA processing model, the primary tiRNAs, precursors and mature tiRNAs could be discovered to completely reveal tiRNAs from their origins to functions. The ltiRNA/tiRNA system and their regulation mechanisms could exist ubiquitously in eukaryotes and prokaryotes. These findings will enrich the basic concepts in the field of mitochondrial biology, lnRNA functions and regulation of gene expression.
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