关于2005年版《中国药典》(一部)附录灰分测定法中操作方法的探讨

目的:对2005年版《中国药典》(一部)中的灰分测定法、炽灼残渣检查法的操作进行改进。方法:采用2种方法,一种为2005年版《中国药典》(一部)收载方法;另一种为改进方法,分别对所选样品进行总灰分、酸不溶性灰分的检查。结果:与2005年版《中国药典》(一部)收载方法比较,改进后方法节省了时间,降低了能耗,提高了效率。结论:改进后的测定方法优于2005年版《中国药典》(一部)方法。     

The effectiveness of respiratory protection worn by communities to protect from volcanic ash inhalation. Part I: Filtration efficiency tests

During volcanic eruptions and their aftermath, communities may be concerned about the impacts of inhaling volcanic ash. Access to effective respiratory protection (RP) is therefore important for many people in volcanic areas all over the world. However, evidence to support the use of effective RP during such crises is currently lacking. The aim of this study was to build the first evidence base on the effectiveness of common materials used to protect communities from ash inhalation in volcanic crises.We obtained 17 forms of RP, covering various types of cloth through to disposable masks (typically used in occupational settings), which communities are known to wear during volcanic crises. The RP materials were characterised and subjected to filtration efficiency (FE) tests, which were performed with three challenge dusts: ashes from Sakurajima (Japan) and Soufrière Hills (Montserrat) volcanoes and aluminium oxide (Aloxite), chosen as a low-toxicity surrogate dust of similar particle size distribution. FE tests were conducted at two concentrations (1.5?mg/m³ and 2.5?mg/m³) and two flow rates (equivalent to 40 and 80?l/min through 15.9?cm² sections of each RP type). Each material was held in a sample holder and PM_2.5 dust concentrations were measured both outside the mask material and inside the sample holder to determine FE. A limited number of tests were undertaken to assess the effect on FE of wetting a bandana and a surgical mask, as well as folding a bandana to provide multiple filter layers.Overall, four RP materials performed very well against volcanic ash, with median FEs in excess of 98% (N95-equiv., N99-equiv., PM_2.5 surgical (Japan), and Basic flat-fold (Indonesia)). The two standard surgical masks tested had median FEs of 89–91%. All other materials had median FEs ranging from 23 to 76% with no cloth materials achieving >44%. Folding a bandana resulted in better FE (40%; 3× folded) than single-layered material (29%). Wetting the bandana and surgical mask material did not improve FE overall.This first evidence base on the FE of common materials used to protect communities in volcanic crises from ash inhalation has been extended in a companion study (Steinle et al., 2018) on the total inward leakage of the best-performing masks when worn by human volunteers. This will provide a complete assessment of the effectiveness of these RP types.     

洁牙后牙面抛光最佳实施条件的筛选及安全性报告

目的:通过观察使用不同抛光方法在不同抛光条件下对牙体硬组织表面结构的影响以及临床治疗后的效果,筛选出安全有效的抛光方法和最佳抛光条件,以降低菌斑、色素的再附着速度,达到最佳临床治疗效果。方法:选用牙周病患牙需拔除的前牙96颗,先分别做喷砂抛光(APP)与橡皮环抛光(RCP)法最佳抛光处理条件筛选实验;再进一步对APP与RCP法筛选出的最佳抛光处理条件进行安全性评价。结果:APP电镜下观察的效果与操作者对牙面施加的压力有关,而与选用的不同喷砂机型无关;RCP电镜下效果评分与操作者对牙面施加的压力、抛光时间有关,而与选用的不同洁牙机型、抛光膏类型无关。结论:APP控制喷砂剂量在0.4g(0.40.5g)、抛光时间2s、操作者对牙面施加的压力为0.3N最佳抛光条件时,对洁牙是安全有效的。RCP抛光时间为6s以内、操作者对牙面施加的压力0.5N以内视为安全有效。     

Spontaneous Dislodgement of Tunneled Dialysis Catheters after De Novo versus Over-The-Wire-Exchange Placement

PurposeTo evaluate dislodgement of tunneled dialysis catheters (TDCs) in de novo (DN) placement with ultrasound versus over-the-wire exchange (OTWE).Materials and MethodsData were collected retrospectively on all TDC placements at this institution from 2001 to 2019 and were excluded if no removal date was recorded or if dwell time was more than 365 days. Information on TDC brand, placement, insertion/removal, and removal reason were collected. Multiple logistic regression evaluated factors associated with TDC dislodgement. DN placement and OTWE were compared for rate of dislodgement (generalized estimating equations method) and TDC dwell time (survival analysis).ResultsIn total, 5328 TDCs were included with 66% (3522) placed DN and 32% (1727) via OTWE. Mean dwell time was 65 ± 72 days, and dislodgement occurred in 4% (224). TDC dislodgement rates in the DN and OTWE groups were 0.48 and 0.93 per 1000 catheter days, respectively. Brand (Ash Split vs. VectorFlow), placement technique (OTWE vs. DN), laterality (left vs. right), and site (left vs. right internal jugular vein) were significant predictors of dislodgement. OTWE placement exhibited 1.7 times the odds of dislodgement (95% confidence interval, 1.2–2.6; P = .004) compared to DN and had significantly higher probability of dislodgement across time (hazard ratio = 2.0; P < .001) compared to DN. Dislodgement rates for OTWE vs. DN were 8% vs. 3% (3 months), 13% vs. 6% (6 months), and 38% vs. 17% (1 year).ConclusionsTDC spontaneous dislodgement rates were significantly and consistently higher after OTWE compared to DN placement. These data support more careful attention to catheter fixation after OTWE placement.     

洁治术后抛光处理在吸烟患者牙周基础治疗中的疗效评价

目的观察吸烟患者超声洁牙及喷砂后橡皮杯抛光对菌斑指数和出血指数的影响。方法选择40例要求沽牙的吸烟患者,进行超声洁治、喷砂抛光后,采用自身对照设计,随机把同一受试者左右侧牙齿分为实验组（洁治喷砂加橡皮杯抛光）和对照组（洁治喷砂）,观察菌斑指数和出血指数的变化。结果在治疗后3个月、6个月的菌斑指数检查显示,实验组均明显低于对照组（P〈0．05）,治疗后6个月,实验组的出血指数明显低于对照组（P〈0．05）。结论洁治喷砂后用橡皮杯抛光处理更能有效提高牙面的清洁度、光滑度,不利于牙菌斑、色素的再附着。     

Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula

Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO₂) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40×70 m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (p<0.001), water-soluble Ca, Mg, Na, SiO₂ and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p<0.001 and p<0.01, respectively, and a non-significant impact in the third, at p<0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe (p<0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed fire will improve soil nutrient status without causing soil degradation and thus is considered to be a good management strategy.     

Compressive behaviour of child and adult cortical bone

In this study, cortical bone tissue from children was investigated. It is extremely difficult to obtain human child tissue. Therefore, the only possibility was to use bone tissue, free from any lesion, collected from young bone cancer patients.The compressive mechanical behaviour of child bone tissue was compared to the behaviour of adult tissue. Moreover, two hypotheses were tested: 1) that the mechanical behaviour of both groups is correlated to ash density; 2) that yield strain is an invariant.Small parts of the diaphysis of femora or tibiae from 12 children (4–15 years) and 12 adults (22–61 years) were collected. Cylindrical specimens were extracted from the cortical wall along the longitudinal axis of the diaphysis. A total of 107 specimens underwent compressive testing (strain rate: 0.1 s^{− 1}). Only the specimens showing a regular load–displacement curve (94) were considered valid and thereafter reduced to ash.It was found that the child bone tissue had significant lower compressive Young's modulus (− 34%), yield stress (− 38%), ultimate stress (− 33%) and ash density (− 17%) than the adult tissue. Conversely, higher compressive ultimate strain was found in the child group (+ 24%). Despite specimens extracted from both children and adults, ash density largely described the variation in tissue strength and stiffness (R² = in the range of 0.86–0.91). Furthermore, yield strain seemed to be roughly an invariant to subject age and tissue density.These results confirm that the mechanical properties of child cortical bone tissue are different from that of adult tissue. However, such differences are correlated to differences in tissue ash density. In fact, ash density was found to be a good predictor of strength and stiffness, also for cortical bone collected from children. Finally, the present findings support the hypothesis that compressive yield strain is an invariant.     

鸡骨香药材水分、灰分及浸出物含量测定

目的：建立鸡骨香的水分、灰分及浸出物的限度检查,为鸡骨香药材的质量标准提供依据.方法：采用2010年版《中国药典》方法对鸡骨香中的水分、灰分及浸出物进行测定,并对浸出物的提取条件进行优化.结果：测得鸡骨香药材中水分不得超过11.4％,总灰分不得超过7.0％,浸出物测定用稀乙醇做溶剂,以热浸法进行测定,所得浸出物不得低于14.0％.结论：鸡骨香的浸出物、水分、灰分含量可作为鸡骨香药材质量标准的重要指标之一.     

鼠疫坟茔尸骨检验结果分析

目的 检测死于50年前的鼠疫病人尸骨及尸骨周围土壤是否存在鼠疫菌。方法 利用鼠疫细菌学和血清学方法对尸骨和土壤进行检验。结果 尸骨及土壤中没有分离到鼠疫菌。结论 在尸体腐烂过程中其条件不利于鼠疫菌存活，加之50～60年风干的环境亦可导致鼠疫菌的死亡。