Measurement of pulse oximetry,capnography and pH

The measurement of arterial oxygen saturations, end-tidal carbon dioxide and pH are all key to modern anaesthetic practice. They can all be measured in a variety of ways, but the most common are discussed in this article. The understanding of the underlying physical principles and how the anaesthetist monitors function to measure these variables is discussed in this article, including limitations and inaccuracies of each technique.     

The Microstructural Evolution and Mechanical Properties of Zr-Based Metallic Glass under Different Strain Rate Compressions

In this study, the high strain rate deformation behavior and the microstructure evolution of Zr-Cu-Al-Ni metallic glasses under various strain rates were investigated. The influence of strain and strain rate on the mechanical properties and fracture behavior, as well as microstructural properties was also investigated. Before mechanical testing, the structure and thermal stability of the Zr-Cu-Al-Ni metallic glasses were studied with X-ray diffraction (XRD) and differential scanning calorimeter. The mechanical property experiments and microstructural observations of Zr-Cu-Al-Ni metallic glasses under different strain rates ranging from 10⁻³ to 5.1 × 10³ s⁻¹ and at temperatures of 25 °C were investigated using compressive split-Hopkinson bar (SHPB) and an MTS tester. An in situ transmission electron microscope (TEM) nanoindenter was used to carry out compression tests and investigate the deformation behavior arising at nanopillars of the Zr-based metallic glass. The formation and interaction of shear band during the plastic deformation were investigated. Moreover, it was clearly apparent that the mechanical strength and ductility could be enhanced by impeding the penetration of shear bands with reinforced particles.     

家庭群居爆发型新型冠状病毒肺炎的临床与胸部HRCT表现

目的 探讨家庭群居爆发型新型冠状病毒肺炎（简称"新冠肺炎"）（novel coronavirus pneumonia，NCP）的临床与胸部HRCT表现特点。方法 收集2020年2月3所医院经核酸检测阳性确诊的新冠肺炎患者10例（4个家庭），其中男性6例（中位年龄60.5岁），女性4例（中位年龄59岁）。所有患者均接受胸部CT扫描并行薄层HRCT重建，由两名10年以上工作经验放射科医生共同阅片分析新冠肺炎HRCT病变发生部位、形态、分布、密度等特点，以及治疗前后HRCT征象变化。并收集临床和实验室指标进行分析和总结。结果 本组4个家庭中首例确诊病例均有武汉确诊病例或武汉疫区接触史，4例为输入型病例（占40%），平均潜伏期5 d。实验室检查中5例（50%）外周血白细胞总数降低，4例（40%）淋巴细胞明显降低；8例（80%）C-反应蛋白增高，10例（100%）乳酸脱氢酶增高。10例（100%）患者胸部CT均有阳性表现，其中7例（70%）表现为双肺散在分布磨玻璃密度影（ground glass opacity，GGO），病变界限大多清楚。8例（80%）累及多个肺叶，2例（20%）为单肺叶病变。绝大多数病灶位于胸膜下和肺外周处，以双肺下叶为著。5例患者（50%）病变内可见细支气管充气征，9例患者（90%）病变内可见增粗细小血管影。7例患者（70%）治疗后复查胸部CT，3例（30%）原肺内胸膜下病变出现不同程度实变及纤维化，2例（20%）实变影转变为GGO，1例（10%）原肺内GGO消失，又出现新发GGO，1例（10%）病变范围有增大。结论 新冠肺炎具有家庭群居爆发的特点，均可有输入性病例，潜伏期较短，其胸部HRCT表现具有一定特征性，且有助于治疗后患者病变动态观察；结合流行病学和实验室检查有助于对NCP做出临床诊断和提供疫情防控的可靠依据。     

面部玻璃异物1例报道

<正>面部外伤后异物存留的病例并不少见。对于单个的、较大的、位置表浅的异物,手术取出相对较为容易;而对于大量的、细小的、位置较深且较分散的异物,要做到手术彻底清除,对口腔颌面外科医生而言是一个挑战[1]。兹有右侧面部玻璃刺伤后大量异物存留的病例1例,该病例经过手术治疗后,达到彻底清除的效果,现报道如下。1临床资料患者女性,69岁,自诉9 h前不慎摔倒,头部撞碎玻璃门后,右侧面部被下方的玻璃刺入,即感患     

Inhibition of enamel demineralization and bond‐strength properties of bioactive glass containing 4‐META/MMA‐TBB‐based resin adhesive

We investigated the enamel demineralization‐prevention ability and shear bond strength (SBS) properties of 4‐methacryloxyethyl trimellitic anhydride/methyl methacrylate‐tri‐n‐butyl borane (4‐META/MMA‐TBB)‐based resin containing various amounts (0–50%) of bioactive glass (BG). Disk‐shaped specimens were immersed in distilled water and ions released were analysed by inductively coupled plasma atomic‐emission spectroscopy. Samples were also immersed in lactic acid solution (pH 4.6) to estimate acid‐neutralizing ability. Brackets were bonded to human premolars with BG‐containing resins and the bonded teeth were alternately immersed in demineralizing (pH 4.55) and remineralizing (pH 6.8) solutions for 14 d. The enamel hardness was determined by nanoindentation testing at twenty equidistant distances from the external surface. The SBS for each sample was examined. The amounts of ions released [calcium (Ca), sodium (Na), silicon (Si), and boron (B)] and the acid‐neutralizing ability increased with increasing BG content. After alternating immersion, the specimens bonded with the BG‐containing resin with high BG content were harder than those in the other groups in some locations 1–18.5 μm from the enamel surface. Bioactive glass‐containing (10–40%) resin had bond strength equivalent to the control specimen. Thus, the SBS obtained for BG‐containing resin (6.5–9.2 MPa) was clinically acceptable, suggesting that this material has the ability to prevent enamel demineralization.     

Evaluation of the effectiveness of bioactive glass fillers against Candida albicans adhesion to PMMA denture base materials: An in vitro study

BackgroundDentures with antimicrobial properties are desirable for preventing Candida albicans adhesion. This study was to assess the effectiveness of bioactive glass (BAG) on C. albicans adhesion, surface roughness, and hardness of denture base materials.MethodsHeat-polymerized (HP) and autopolymerized (AP) acrylic resins were used to fabricate 240 disk specimens (120/material, 60/C. albicans, 60/surface roughness and hardness). Specimens were divided into five groups (n = 10) based on the BAG concentration: 0.5, 1.5, 3, 5, and 7.5 wt% of the acrylic powder, with a control group comprised of unmodified specimens. Direct culture method was used to assess C. albicans adhesion. A profilometer and Vickers hardness test were used to measure surface roughness and hardness respectively. Analysis of variance (ANOVA) and post hoc Tukey’s test were used for data analysis (α = 0.05).ResultsBAG addition significantly decreased the C. albicans count when compared with the control group (P < 0.001) for both HP and AP. Regarding surface roughness, there was no change in the HP acrylic resins (P > 0.05), while the AP acrylic resins exhibited significantly higher surface roughness with BAG addition (P < 0.001). The hardness of the HP and AP acrylic resins were significantly higher with the addition of BAG (P < 0.001).ConclusionsThe addition of BAG to HP and AP acrylic resins effectively decreases C. albicans adhesion. The roughness of AP acrylic resins increases with the addition of BAG, while the hardness of both HP and AP acrylic resins increase with the addition of BAG.     

Timing of Uterine Artery Embolization for Leiomyoma during the Menstrual Cycle

PurposeTo investigate differences in outcomes of uterine artery embolization (UAE) for leiomyoma when performed during different phases of the menstrual cycle.Materials and MethodsIn this single-institution retrospective analysis, 111 premenopausal patients (median [range] age, 44 [33–52] years) undergoing UAE for symptomatic leiomyoma between June 2014 and February 2020 were included. Twenty-one patients underwent UAE in the menstrual phase (the early follicular phase), 27 in the late follicular phase, and 63 in the luteal phase. Baseline characteristics and technical and peri-procedural outcomes were compared among groups. Leiomyoma infarction on contrast-enhanced magnetic resonance imaging 1 week after UAE and 4-month outcomes, including changes in the Uterine Fibroid Symptom and Quality of Life questionnaire scores, the volume reduction rates of the uterus and largest leiomyoma, follicle stimulating hormone values, adverse events, and amenorrhea, were compared among groups.ResultsA 4-month follow-up was completed for all patients. No significant differences were observed among groups in baseline characteristics or technical and peri-procedural outcomes. There were no significant differences in the multivariate-adjusted 1-week infarction rates of all leiomyoma volumes (P = .161) or multivariate-adjusted 4-month outcomes, including changes in the Uterine Fibroid Symptom and Quality of Life questionnaire symptoms and total scores (P = .864 and P = .798, respectively), the volume reduction rates of the uterus and the largest leiomyoma (P = .865 and P = .965, respectively), and follicle stimulating hormone values (P = .186) among the groups. No significant differences were noted in the 4-month adverse events (P = .260) or amenorrhea (P = .793) among the groups.ConclusionsThe present study demonstrated no significant differences in the outcomes of UAE for leiomyoma when performed during different phases of the menstrual cycle.     

在头戴式放大镜直视下小鼠气管插管方法的建立

目的建立并评价一种新的小鼠气管插管方法。方法30只NIH小鼠分设A、B、C组(n=10),麻醉后特殊体位固定,在头戴式放大镜直视下施行气管插管。A组小鼠经套管注射美蓝,死后解剖判断插管成功与否;B组插管后即拔管,隔天1次,连续2周。C组仅麻醉但不插管,方法同B组。在实验的最后1天,B、C组小鼠的处理同A组。结果所有小鼠死后解剖可见气管下端至肺部均有蓝色物质浸染,插管成功率为100%,B组小鼠经多次插管操作仍能健康存活,与C组比较未发现生长迟缓、体重明显减低等情况。结论我们建立的小鼠气管插管方法操作简单、易学、可重复性强,值得推广。     

Paclitaxel and etoposide-loaded Poly (lactic-co-glycolic acid) microspheres fabricated by coaxial electrospraying for dual drug delivery

Abstract

In this study, we fabricated paclitaxel (PTX) and etoposide (ETP) loaded Poly (lactic-co-glycolic acid) (PLGA) microspheres with core–shell structures and particle sizes ranging from 1 to 4?µm by coaxial electrospraying. The microspheres were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM). The drug loading rate and entrapment efficiency of the microspheres were detected by high performance liquid chromatograph (HPLC). Moreover, the drug release profiles and degradation of drug-loaded PLGA microspheres in vitro were investigated, respectively. The distinct layered structure that existed in the manufactured core–shell microspheres can be observed by TEM. The in vitro release profiles indicated that the PLGA/PTX?+?ETP (PLGA/PE) microspheres exhibited the controlled release of two drugs in a sequential manner. Cell Counting Kit-8 was used to detect the toxic and side effects of the microspheres on bone tumor cells. PTX and ETP for combination drug therapy loaded microspheres had more cytotoxic effect on saos-2 osteosarcoma cells than the individual drugs. In conclusion, core–shell PLGA microspheres by electrospraying for combination drug therapy is promising for medicine applications, the PLGA/PE microspheres have some potential for osteosarcoma treatment.