基于提升小波变换和SPIHT的医学图像编码算法

目的:探讨一种基于提升小波变换和多级树集合分裂算法(set partitioning in hierarchical trees,SPIHT)的医学图像编码算法。方法:针对传统小波浮点数运算,计算量大的缺点,采用提升格式小波,结合多级树集合分裂算法和算术编码,实现对医学图像的编码。结果:在获得较高压缩比的情况下,能保证医学图像的重建质量,满足医学图像数据的存储和传输的需要。结论:仿真结果表明在相同压缩比的情况下,重建图像的峰值信噪比有明显提高,获得了较好的压缩效果。     

应用数字编号法提供合格灭菌手术包

目的　用数字编号法能更简单、完善地为医患双方提供合格的无菌手术包。方法　用数字编号法比较无菌手术包内压力蒸气灭菌化学指示卡粘贴法的优缺点 ,将数字编号和灭菌手术包内压力蒸气灭菌化学指示卡合格记录于手术护理记录单上 ,与无菌手术包内压力蒸气灭菌化学指示卡粘贴于手术护理记录单背面作比较。结果　数字编号法弥补了灭菌手术包内压力蒸气灭菌化学指示卡粘贴法的不足 ,使其更方便、适用。结论　无菌手术包数字编号法可为有关护理同仁提供参考     

Distorted Tonotopy Severely Degrades Neural Representations of Connected Speech in Noise following Acoustic Trauma

Listeners with sensorineural hearing loss (SNHL) struggle to understand speech, especially in noise, despite audibility compensation. These real-world suprathreshold deficits are hypothesized to arise from degraded frequency tuning and reduced temporal-coding precision; however, peripheral neurophysiological studies testing these hypotheses have been largely limited to in-quiet artificial vowels. Here, we measured single auditory-nerve-fiber responses to a connected speech sentence in noise from anesthetized male chinchillas with normal hearing (NH) or noise-induced hearing loss (NIHL). Our results demonstrated that temporal precision was not degraded following acoustic trauma, and furthermore that sharpness of cochlear frequency tuning was not the major factor affecting impaired peripheral coding of connected speech in noise. Rather, the loss of cochlear tonotopy, a hallmark of NH, contributed the most to both consonant-coding and vowel-coding degradations. Because distorted tonotopy varies in degree across etiologies (e.g., noise exposure, age), these results have important implications for understanding and treating individual differences in speech perception for people suffering from SNHL.SIGNIFICANCE STATEMENT Difficulty understanding speech in noise is the primary complaint in audiology clinics and can leave people with sensorineural hearing loss (SNHL) suffering from communication difficulties that affect their professional, social, and family lives, as well as their mental health. We measured single-neuron responses from a preclinical SNHL animal model to characterize salient neural-coding deficits for naturally spoken speech in noise. We found the major mechanism affecting neural coding was not a commonly assumed factor, but rather a disruption of tonotopicity, the systematic mapping of acoustic frequency to cochlear place that is a hallmark of normal hearing. Because the degree of distorted tonotopy varies across hearing-loss etiologies, these results have important implications for precision audiology approaches to diagnosis and treatment of SNHL.     

人乳头瘤病毒16型早基因E6/E7编码区序列变异研究

目的获取人乳头瘤病毒16型早基因E6/E7的编码区序列并进行变异分析,为新型分子诊断方法的研发提供目标序列。方法通过导流杂交基因芯片技术获取人乳头瘤病毒16型感染宫颈脱落细胞。设计特异性引物,扩增人乳头瘤病毒16型早基因E6/E7的编码区序列,克隆后测序并对序列进行变异分析。结果通过导流杂交基因芯片技术进行宫颈脱落细胞的分型检测,获得了人乳头瘤病毒16型感染阳性标本;选择其中3份阳性标本核酸为模板,通过特异性引物均成功扩增出大小介于750 bp和1 000 bp之间的目的序列;分别克隆到T载体上并测序,得到3条人乳头瘤病毒16型早表达基因E6/E7的编码区序列,克隆并测序后向GenBank核酸数据库提交获收录,登录号分别为EU869316、EU869317和EU869318;经BLAST分析,3条序列与GenBank序列PPH16（Accession：K02718）的E6/E7编码区序列一致性均为99%,且存在8种碱基置换,其中4种为同义突变,另4种则可引起所编码的相应氨基酸残基改变。结论本研究得到了与HPV高危型16型PPH16高度相似的E6/E7编码序列,为HPV致病机制和新型分子检测方法研究奠定了基础。     

Envelope Coding in Auditory Nerve Fibers Following Noise-Induced Hearing Loss

Recent perceptual studies suggest that listeners with sensorineural hearing loss (SNHL) have a reduced ability to use temporal fine-structure cues, whereas the effects of SNHL on temporal envelope cues are generally thought to be minimal. Several perceptual studies suggest that envelope coding may actually be enhanced following SNHL and that this effect may actually degrade listening in modulated maskers (e.g., competing talkers). The present study examined physiological effects of SNHL on envelope coding in auditory nerve (AN) fibers in relation to fine-structure coding. Responses were compared between anesthetized chinchillas with normal hearing and those with a mild–moderate noise-induced hearing loss. Temporal envelope coding of narrowband-modulated stimuli (sinusoidally amplitude-modulated tones and single-formant stimuli) was quantified with several neural metrics. The relative strength of envelope and fine-structure coding was compared using shuffled correlogram analyses. On average, the strength of envelope coding was enhanced in noise-exposed AN fibers. A high degree of enhanced envelope coding was observed in AN fibers with high thresholds and very steep rate-level functions, which were likely associated with severe outer and inner hair cell damage. Degradation in fine-structure coding was observed in that the transition between AN fibers coding primarily fine structure or envelope occurred at lower characteristic frequencies following SNHL. This relative fine-structure degradation occurred despite no degradation in the fundamental ability of AN fibers to encode fine structure and did not depend on reduced frequency selectivity. Overall, these data suggest the need to consider the relative effects of SNHL on envelope and fine-structure coding in evaluating perceptual deficits in temporal processing of complex stimuli.     

Qualitative research in nutrition and dietetics: data analysis issues

Although much of the analysis conducted in qualitative research falls within the broad church of thematic analysis, the wide scope of qualitative enquiry presents the researcher with a number of choices regarding data analysis techniques. This review, the third in the series, provides an overview of a number of techniques and practical steps that can be taken to provide some structure and focus to the intellectual work of thematic analysis in nutrition and dietetics. Because appropriate research methods are crucial to ensure high‐quality research, it also describes a process for choosing appropriate analytical methods that considers the extent to which they help answer the research question(s) and are compatible with the philosophical assumptions about ontology, epistemology and methodology that underpin the overall design of a study. Other reviews in this series provide a model for embarking on a qualitative research project in nutrition and dietetics, an overview of the principal techniques of data collection, sampling and quality assessment of this kind of research and some practical advice relevant to nutrition and dietetics, along with glossaries of key terms.     

Radiographic detection of artificial intra-bony defects in the edentulous area

Background: Since intra-bony pathologies might jeopardize implant outcome, their preoperative detection is crucial.
Material and methods: In sixteen human cadaver bloc sections from upper and lower jaws, artificial defects with progressively increasing size ( n =7) have been created. From each respective defect, analogue and digital intra-oral radiographs were taken, the latter processed via a periodontal filter and afterwards presented in black-white as well as in colour, resulting in three sets of 7 images per bloc section. Eight observers were asked to diagnosis an eventual defect on randomly presented radiographs, and at another occasion to rank each set based on the defect size.
Results: The clinicians were only able to identify a defect, when the junctional area was involved, except for bony pieces with a very homogeneous structure.
Conclusion: For longitudinal evaluation of healing bone (e.g. after tooth extraction), colour digital images can be recommended. These observations indicate that intra-oral radiographs are not always reliable for the detection of any intra-bony defect.