Characterization of Acoustic Droplet Vaporization for Control of Bubble Generation Under Flow Conditions

This study investigated the manipulation of bubbles generated by acoustic droplet vaporization (ADV) under clinically relevant flow conditions. Optical microscopy and high-frequency ultrasound imaging were used to observe bubbles generated by 2-MHz ultrasound pulses at different time points after the onset of ADV. The dependence of the bubble population on droplet concentration, flow velocity, fluid viscosity and acoustic parameters, including acoustic pressure, pulse duration and pulse repetition frequency, was investigated. The results indicated that post-ADV bubble growth spontaneously driven by air permeation markedly affected the bubble population after insonation. The bubbles can grow to a stable equilibrium diameter as great as twice the original diameter in 0.5–1 s, as predicted by the theoretical calculation. The growth trend is independent of flow velocity, but dependent on fluid viscosity and droplet concentration, which directly influence the rate of gas uptake by bubbles and the rate of gas exchange across the wall of the semipermeable tube containing the bubbles and, hence, the gas content of the host medium. Varying the acoustic pressure does not markedly change the formation of bubbles as long as the ADV thresholds of most droplets are reached. Varying pulse duration and pulse repetition frequency markedly reduces the number of bubbles. Lengthening pulse duration favors the production of large bubbles, but reduces the total number of bubbles. Increasing the PRF interestingly provides superior performance in bubble disruption. These results also suggest that an ADV bubble population cannot be assessed simply on the basis of initial droplet size or enhancement of imaging contrast by the bubbles. Determining the optimal acoustic parameters requires careful consideration of their impact on the bubble population produced for different application scenarios.     

Round window and promontory movements during bone conduction with different middle ear conditions in Thiel embalmed specimens

Background: Thiel conservation is mainly based on a watery solution of salts. We have shown that bone conduction (BC) evokes motion in normal middle ears of Thiel embalmed specimens that is comparable to the motion for other cadaveric models.

Aims/Objectives: We evaluated whether promontory and round window (RW) motion identifies differences in BC transmission for different middle ear conditions.

Methods: We investigated the conditions of mobile ossicle chain, cement-fixed stapes and stapedectomy in seven ears. A retroauricular bone anchored hearing system provided BC stimulation. The motions of the promontory and the RW were measured using single point laser Doppler vibrometer (LDV, HLV1000, Polytec).

Results: The averaged differences between the conditions were small for RW motion and for promontory motion. However, for RW motion we found differences of more than one standard deviation at some frequencies. These differences in RW motion were more apparent when we limited the analysis to three selected specimens.

Conclusions and Significance: Extracochlear measurement of the RW motion with LDV allowed differentiation between BC for different middle ear conditions. These changes could be detected best in a small frequency range in selected specimens. Promontory motion could not be used to differentiate between different conditions of the middle ear.

ABBREVIATIONS: LDV: laser Doppler vibrometry; Prom: cochlear promontory; RW: round window; ST: stapes; TM: tympanic membrane; VProm: velocity of the promontory; VRW: velocity of the round window     

Experimental manipulation of avoidable feelings of uncertainty: Effects on anger and anxiety

Though anger and anxiety are related, putative explanations for this association remain unclear. Beliefs about one’s state of uncertainty may be a pathway—the belief that one’s uncertain state is unavoidable might lead to anxiety, whereas the belief that one’s uncertain state is avoidable might lead to both anxiety and anger. To test this hypothesis, participants experienced an uncertainty induction and were then assigned to the avoidable uncertainty condition (experimental group) or the unavoidable uncertainty condition (control group). State anger and anxiety were assessed at baseline, following the uncertainty induction, and following the “avoidableness” manipulation. The uncertainty induction was successful; participants reported higher levels of anxiety at post-induction compared to baseline. As expected, the experimental group reported increases in anger from post-induction to post-manipulation whereas the control group reported decreases in anger. These findings suggest that when one’s state of uncertainty is avoidable, anger is experienced alongside anxiety.     

Effect of a functional monomer (MDP) on the enamel bond durability of single‐step self‐etch adhesives

The present study aimed to determine the effect of the functional monomer, 10‐methacryloxydecyl dihydrogen phosphate (MDP), on the enamel bond durability of single‐step self‐etch adhesives through integrating fatigue testing and long‐term water storage. An MDP‐containing self‐etch adhesive, Clearfil Bond SE ONE (SE), and an experimental adhesive, MDP‐free (MF), which comprised the same ingredients as SE apart from MDP, were used. Shear bond strength (SBS) and shear fatigue strength (SFS) were measured with or without phosphoric acid pre‐etching. The specimens were stored in distilled water for 24 h, 6 months, or 1 yr. Although similar SBS and SFS values were obtained for SE with pre‐etching and for MF after 24 h of storage in distilled water, SE with pre‐etching showed higher SBS and SFS values than MF after storage in water for 6 months or 1 yr. Regardless of the pre‐etching procedure, SE showed higher SBS and SFS values after 6 months of storage in distilled water than after 24 h or 1 yr. To conclude, MDP might play an important role in enhancing not only bond strength but also bond durability with respect to repeated subcritical loading after long‐term water storage.     

杠杆定位手法治疗腰椎间盘突出症疗效及对Cobb角影响

目的:观察杠杆定位手法治疗腰椎间盘突出症疗效及对Cobb角的影响。方法:2017年12月至2018年11月纳入67例腰椎间盘突出症患者进行研究,将67例患者用随机数字表法分为治疗组和对照组。治疗组34例,其中男20例,女14例,年龄(36.09±8.26)岁,病程(13.79±15.50)个月,采用杠杆定位手法治疗。对照组33例,其中男18例,女15例,年龄(36.48±7.81)岁,病程(12.82±15.68)个月,采用腰椎斜扳法治疗。两组每周均治疗3次,隔1 d治疗1次,6次为1个疗程,治疗2个疗程后,通过影像学资料比较两组患者治疗前后Cobb角的变化;参照临床评定标准对症状体征进行评分;参照国家中医药管理局颁布的腰椎间盘突出症《中医病证诊断疗效标准》对总体疗效进行评价。结果:两组各有1例脱落患者。治疗组和对照组治疗前症状体征评分分别是18.56±4.81,18.61±3.72,治疗后分别为9.41±5.19,13.55±3.68,治疗后治疗组症状体征评分明显低于对照组(P<0.05),总体疗效有效率治疗组和对照组分别为97.06%、75.76%,治疗组优于对照组(P<0.05),治疗后两组患者的Cobb角均有变小(P<0.05)。治疗组和对照组治疗前Cobb角分别为(17.95±4.45)°,(18.14±3.59)°,治疗后分别为(18.14±3.59)°,(15.49±1.75)°,治疗组Cobb角变化优于对照组(P<0.05)。结论:杠杆定位手法与腰椎斜扳法两种方法对腰椎间盘突出症治疗均有疗效,但杠杆定位手法治疗腰椎间盘突出症患者的疗效更为显著,对Cobb角的影响更为明显,值得推广。     

Outcome of manipulation under anesthesia with or without intra-articular steroid injection for treating frozen shoulder: A retrospective cohort study

Manipulation under anesthesia (MUA) combined with intra-articular steroid injection (ISI) is preferred in management of the refractory frozen shoulder (FS). This study aimed to evaluate the effect of MUA with ISI or not on pain severity and function of the shoulder.Data on 141 patients receiving MUA with primary FS refractory to conservative treatments for at least 1 month were retrospectively obtained from medical records. We performed propensity score matching analysis between patients receiving MUA only and those receiving MUA plus ISI, and then conducted logistic regression analysis to identify the risk factors for the need to other treatments during 6-month follow-up.More improvement in terms of the SPADI pain scores and passive ROM at 2 weeks after first intervention remained in patients receiving MUA plus ISI after matching. The need to other treatments during 6-month follow-up occurred in 10.6% patients (n = 141). Logistic regression analysis revealed that a repeat MUA 1 week after first intervention was a protective factor (OR 0.042; 95% CI 0.011–0.162; P = .000) and duration of disease was the only one risk factor (OR 1.080; 95% CI 1.020–1.144; P = .008) for the need to other treatments during follow-up.ISI immediately following MUA provided additional benefits in rapid relief of pain and disability for patients with refractory FS. Pain and disability of the shoulder may be rapidly alleviated by an earlier MUA from the onset of the symptoms and a repeat MUA 1 week after first intervention.     

五步推拿法辅治小儿腹泻经验

运用五步推拿法加减辅助内服中药治疗小儿腹泻，据证之虚实运用相应的补泻手法，有促进药物吸收、增强疗效、缩短疗程的作用，而且无痛苦，无毒副作用，患儿容易接受，更宜于服药困难的小儿，并举验案五则以证之。     

经皮肾一步扩张法在结石所致梗阻性肾功能不全中的应用

目的 探讨超声引导下经皮肾一步扩张法在结石性梗阻性肾功能不全中的临床效果.方法 选择我院2009年7月～2011年7月因结石所致上尿路梗阻,合并梗阻性肾积液、肾功能不全患者68例,随机分为一步扩张法( One-step)组和逐步式(Multi- step)组分别行经皮肾穿刺微造瘘引流术,每组各34例.One-step组在超声引导下一步式经皮肾穿刺微造瘘(PCN)直接穿刺引流,Multi-step组采用传统Seldinger法逐级扩张经皮肾通道实施造瘘引流.对比观察两组患者建立经皮肾通道的手术时间、术中出血量、成功率、术后并发症及肾功能的变化情况.结果 One-step组手术时间、扩张次数、术中出血量均少于Multi-step组,差异有显著性(P＜0.05).One-step组一次穿刺置入造瘘管的成功率明显高于Multi-step组,而术后并发症发生率明显低于multi-step组,差异均有显著性(P＜0.05).两组患者术后肾功能明显改善,术后2周尿素氮(BUN)、血肌酐(Cr)与术前相比,差异有显著性(P＜0.05),但术后2周两组间BUN、Cr比较,差异无显著性(P＞0.05).结论 一步扩张法经皮肾穿刺微造瘘操作简便、创伤小、出血量少和并发症少,有助于改善梗阻性肾功能不全.