Humidification devices

Humidification is concerned with the addition of water vapour to a gas and can be measured as either absolute or relative. Adequate humidification is a vital consideration in anaesthesia given that the anatomical source of natural gas humidification (the nasopharynx) is generally bypassed, which can lead to complications including hypothermia, thickening of respiratory secretions, mucus plugging and airway keratinization. Humidification may be passive or active. Equipment involved in passive humidification includes HME filters, soda lime and cold water baths, with these devices able to achieve varying efficiencies without extrinsic energy input. Active humidification devices (including hot water baths) are capable of delivering a higher relative humidity but are associated with higher cost and potential hazards. While not strictly classed as true humidification devices, nebulizers are considered in this article as they add water droplets into a gas flow using a Venturi system, spinning discs or ultrasound vibration technology.     

Mould-specific immunoglobulin G antibodies in students from moisture- and mould-damaged schools: A 3-year follow-up study

Immunoglobulin G (IgG) antibodies to moulds have been used as biomarkers of mould exposure, though their role reflecting exposure is not confirmed. The purpose of the present study was to evaluate the changes in mould-specific IgG antibodies in children during a 3-year follow-up in relation to changes in exposure, and to allergic and respiratory morbidity. In 1996, 212 primary school students with asthma, wheezing or prolonged cough participated in a clinical study, including clinical examination, skin-prick tests to 12 moulds and mould-specific IgG determinations to 24 moulds. In 1999, 144 students of the same cohort participated in an identical follow-up study; among them, mould-specific IgG was measured in 121 students. No association was found between IgG antibodies to moulds and exposure to moisture or moulds in schools. Likewise, changes in mould-specific antibodies were only weakly associated with changes in exposure. Mould-specific IgG antibodies had no significant association with asthma, wheezing or cough episodes. IgG antibodies to moulds seem to be poor markers of exposure among children exposed to moisture or moulds at school.     

Laboratory evaluation of heat-and-moisture exchangers

We conducted a laboratory study on six commercially available heat and moisture exchangers in order to determine and compare their water retaining efficiency and their contribution to airway resistance.The Gambro-Engström Edith Flex device was the most desirable of the six devices we evaluated in terms of its water retaining efficiency. The NMI Pneumoist 1 and the Siemens Servo Humidifier 153 units had good water retaining capacity but their higher airflow resistance need close monitoring, especially after prolonged clinical use. The Pall HME 15–22 and the Portex Humid-Vent 1 devices were also efficient in water retaining capacity. The Pall also demonstrated low airflow resistance and the minimum increase in airflow resistance after water immersion. The pathogen filtering capacity of the Pall should also be considered an additional advantage, especially in infected patients. The Terumo Breathaid device performed worst of all six devices, but it was still better than no HME at all.(Kugimiya T, Phuc TG, Numata K: Laboratory evaluation of heat-and-moisture exchangers. J Anesth 3: 80–85, 1989)     

Improvement of the radial forearm donor site by compression with hydrocolloid dressing and adhesive sponge

Conclusions. With our method, general improvement is obtained as compared with traditional split-thickness skin grafting of the radial forearm flap donor site. As our method is simple and easy, the same results can be obtained wherever and by whomever it is performed. Objective. The radial forearm flap is associated with complications of graft take and a poor aesthetic appearance despite its usefulness in reconstructing the oral cavity and oropharynx. We describe a simple technique for improvement of the radial forearm donor site. Patients and methods. We studied 12 patients who underwent reconstruction with radial forearm free flaps following resection of oral or oropharyngeal tumors. We covered the donor site defect using traditional split-thickness skin grafts and performed aftercare with a hydrocolloid dressing and an adhesive sponge to retain moisture and apply compression. After the treatment series, color matching, texture matching, depressive deformity, and hypertrophic scar were evaluated. Results. The results of comprehensive evaluation of the two patients with premature discontinuation of compression were good. One patient was assigned only 1 point for hypertrophic scar, and another only 1 point for color match. The evaluation of the other 10 patients was excellent.     

The role of dentin moisture in the degradation of resin-dentin interfaces under clinical and laboratory conditions

BackgroundThe authors conducted a study to evaluate the influence of dentin moisture on the degradation of the resin-dentin interface in primary teeth under clinical and laboratory conditions.MethodsThe authors prepared 40 Class I restorations (five teeth per group) by using a cylindrical diamond bur, leaving a flat dentin surface on the pulpal floor. They vigorously rubbed two coats of a simplified etch-and-rinse adhesive on either dry or wet demineralized dentin under clinical or laboratory conditions. After performing restorative procedures, the authors extracted teeth prepared under clinical conditions after 20 minutes (immediately) or the teeth exfoliated after six months. The authors also tested the teeth prepared under laboratory conditions immediately or after six months of being stored in water. They sectioned the teeth to obtain resin-dentin bonded specimens for microtensile testing and for silver nitrate uptake (SNU) under scanning electron microscopy. They performed a three-way analysis of variance and Tukey test (α = .05) on the SNU bond strength data.ResultsStatistically higher bond strength values (megapascals [standard deviation]) were observed when bonding was performed under laboratory conditions (clinical = 25.2 [3.6] MPa versus laboratory = 28.5 [4.4] MPa; P < .05). Degradation occurred only in the wet dentin groups under both experimental conditions (immediately = 31.3 [4.5] MPa versus after six months = 21.3 [2.1] MPa; P < .05). SNU occurred in all groups and was statistically higher after six months of clinical function or water storage (immediately = 13.9 [4.9 SD] percent versus after six months = 34.1 [4.5 SD] percent; P < .05).ConclusionsThe bonding of adhesives to dry demineralized dentin produces adhesive interfaces that are more resistant to degradation regardless of the bonding condition.Clinical ImplicationsResin-dentin bond strengths produced under laboratory conditions in primary teeth may be higher than those obtained under clinical circumstances, although both conditions (clinical and laboratory) seemed to yield similar results. Bonding to dry demineralized primary tooth dentin produced resin-dentin interfaces that were more resistant to degradation.     

新型复合生物抗菌敷料的抗菌强度、吸湿能力及细胞毒性

背景：细菌感染是影响伤口愈合的主要因素之一,伤口渗出液里含有的大量炎症因子、蛋白酶和自由基都会减缓伤口的愈合速度。新型复合生物抗菌敷料的研发对治疗外科感染伤口有重要的意义,是创伤敷料发展的必然趋势。 目的：观察添加纳米银的海藻酸钙敷料的抗菌活性、吸湿能力及细胞毒性。 方法：将纳米银材料添加到海藻酸钙中制备新型复合生物抗菌敷料,并通过使用平板计数法、MTT法、电子显微镜观察法观察敷料的抗菌活性、吸湿能力及细胞毒性,再与银离子海藻酸钙敷料和海藻酸钙敷料进行对比,以期显示出新型复合生物抗菌敷料的具有强抗菌性及低细胞毒性的优势。 结果与结论：与银离子海藻酸钙敷料和海藻酸钙敷料相比,添加纳米银的新型复合生物抗菌敷料对金黄色葡萄球菌、铜绿假单胞菌均有更强的抑菌作用(P < 0.01),细胞毒性较低(P < 0.01);3种敷料的吸湿能力差异无显著性意义。证实此添加纳米银的海藻酸钙敷料的具有强抗菌性及低细胞毒性。      

Skin-prick test findings in students from moisture- and mould-damaged schools:A 3-year follow-up study

Dampness and moisture problems in a building may cause growth of moulds, leading to sensitization and symptoms in the inhabitants. The mechanism by which sensitization to moulds takes place has remained obscure; in particular, the role of atopy is not clear. In 1996, 622 pupils (7–13 years of age) attending a school with a moisture problem (index school; 414 pupils) and a control school (208 pupils) were screened using a questionnaire. Two-hundred and twelve children had doctor-diagnosed asthma, parental-reported wheezing or prolonged cough, and they participated in a clinical study, which included skin prick tests (SPT) to 12 moulds. An identical, follow-up study was performed 3 years later in 1999. In the follow-up study, 144 of the original 212 students participated. They were now attending four different schools: the index primary school had been renovated and the control school remained unchanged, but the two secondary schools had moisture and mould problems. The purpose of the study was to evaluate the occurence of mould allergy in children of school age and to compare sensitization to moulds in relation to age, exposure, asthma, and atopy. In 1999, SPT responses to moulds were demonstrated in 17 (12%) of the 144 children. Six children had SPT reactions ≥ 3 mm and all but one were older than 14 years. During the 3-year follow-up period, mould allergy developed in five children and disappeared in two children. Five of the six children with reactions ≥ 3 mm to moulds had positive responses to other allergens, five had clinical atopy but only two had asthma. Likewise, all six children had been exposed to moisture and dampness in the school buildings. In conclusion, mould allergy diagnosed by SPTs was rare in students. Most reactions to moulds were in students older than 14 years with multiple SPT reactions to common allergens, and there was no significant association with asthma.     

东北不同产地人参及其加工品外观性状及非皂苷类成分比较分析

目的:考察东北不同产地人参及其加工品的外观性状以及水分、灰分、浸出物、挥发油含量,为其质量标准的制定和适宜种植的区域提供可供参考的依据。方法:参考药典和相关文献,分别测定10个不同产地生晒参以及红参的外观性状、水分、灰分、浸出物、挥发油含量,并对各检测指标进行DTOPSIS分析。结果:长白、集安、抚松3个产地的生晒参和红参在各项检测指标中均达到了药典标准和国标要求,并且在DTOPSIS分析中得到的综合评价值较高。结论:不同产地的生晒参以及红参的药材质量差异较大,部分产地生晒参和人参尚未达到药典标准和国标要求。本研究所测定各项指标较优的3个产地人参都来自人参GAP规范化种植基地,由此反应了GAP规范化种植对于保证人参质量的重要性。     

基于支持向量机的黄连饮片产地识别研究

目的建立基于支持向量机的黄连饮片产地区分识别模型。方法采集4个产地多批黄连样本,量化外部特征值(包括形状、气味、味道等),并按《中国药典》2010年版方法测定内部特征值(包括水分、总灰分、醇浸出物,指标成分表小檗碱、黄连碱、巴马汀、小檗碱质量分数),在Matlab 7.0平台进行数据降维和融合,建立黄连产地区分模型。结果单独分析各项数据不能较好区分各产地黄连饮片,而采用支持向量机建模后所有特征叠加识别率达到97.1%,能准确区分各黄连饮片产地,内外特征的高识别率说明各特征子集间具有一定的互补性,可综合辨识不同产地黄连饮片的差异性。结论建立的基于支持向量机的识别模型,实现产地的区分,为黄连产地区分提供研究思路和基础。