When can it be not optimal to adopt a new technology? A viability theory solution to a two‐stage optimal control problem of new technology adoption

Politicians often deplore economic agents’ behaviour when they do not accept new technologies. For a new technology to be adopted, the new technology value function needs to dominate the old technology value function. If this is the case, a technology switch will occur. We characterise the value functions, without computing them, using the fact that their hypographs are viability kernels of some auxiliary control problems and study whether the graphs intersect. If they do not, the corresponding value functions do not dominate each other, and the switch cannot occur at a positive time. Using this characterisation, we analyse a technology adoption problem and show how to recognise the models, for which the switch will occur at time zero or never, without solving an optimal control problem. We conclude that the current control regime may not change if the economic agents’ preferences are modelled as an integral of discounted differences between a reward from the flow variable (control) and a penalty from the stock variable (state).Copyright © 2011 John Wiley & Sons, Ltd.     

No Difference in Revision Rate Between Low Viscosity and High Viscosity Cement Used in Primary Total Knee Arthroplasty

BackgroundLoosening remains one of the most common reasons for revision total knee arthroplasty (TKA). Cement viscosity has a potential role in reducing revision rates for loosening. The aim of this study was to assess the outcome for loosening of the 5 most used cemented knee prostheses by constraint type, based on the cement viscosity type used.MethodsThere were 214,708 TKA procedures performed between 1999 and 2020 for a diagnosis of osteoarthritis using the 5 most commonly used minimally stabilized, posterior stabilized, and medial pivot design cemented tibial components. Only procedures with a cemented tibial component were included. Outcomes for two different cement viscosities, 140,060 high viscosity and 74,648 low viscosity cement, were compared for each fixation type within each of the three stability groups.ResultsThere was no difference in a risk of all-cause revision when high viscosity cement was used compared to low viscosity cement for minimally stabilized prostheses (hazards ratio [HR] 1.07 [95% CI 0.99-1.15], P = .09), posterior stabilized prostheses (HR 1.03 [95% CI 0.95-1.11], P = .53), and medial pivot design prostheses (HR 1.06 [95% CI 0.80-1.41], P = .67). No difference was observed between cement viscosity types for any of the prosthesis constraint types when aseptic loosening was assessed.ConclusionsWe found no difference in the risk of revision for any reason, or for loosening, with cement viscosity for the most commonly used minimally stabilized, posterior stabilized, and medial pivot TKA. The role of cement viscosity in the risk of TKA revision remains unclear and further research is required.Level of EvidenceLevel III Retrospective comparative study.     

The optimization of technological processes,stability and microbiological evaluation of innovative natural ingredients-based multiple emulsion

Abstract

For the last couple of decades, multiple emulsions were prepared either by the re-emulsification of primary emulsion or they were produced by an emulsion inversion and their technological peculiarities were widely investigated. The aim of our study was to investigate and determine the optimal technological parameters of innovative multiple emulsion, prepared directly—by addition of ethanolic rosemary extract in the presence of polymeric emulsifier—and evaluate its stability by experimental surface response design approach. The results revealed that simplified W/O/W emulsification process is stirring time and stirring speed sensitive: the change of stirring time from 5 to 15?min at 600?rpm resulted in increased viscosity (from 1705.6?±?62.2 to 3364.1?±?112.5?mPA/s) and smaller oil droplet size (from 33.09?±?1.51 to 17.81?±?0.78?μm), though the conductivity increased from 800?±?2 to 882?±?2 μS/cm (p?<?.05). The second mixing stage (1000?rpm) had a negative effect on the conductivity of W/O/W emulsion because of the inner aqueous phase encapsulation efficiency. Ethanolic rosemary extract was used as multifunctional agent: not only to form multiple emulsion but also to preserve it; microbiological assay confirmed its effectiveness. A stable W/O/W type drug delivery system was successfully created without additional technological stages, phase inversion or surfactants.     

淀粉类黏合剂黏度曲线的测定

目的 测定不同类型淀粉类黏合剂的黏度曲线,确定其使用的最佳浓度范围。方法 探索不同类型淀粉的配制方法,采用数字旋转黏度计测定不同种类淀粉黏合剂在不同温度下的黏度并绘制黏度曲线图。结果 不同种类的淀粉制成淀粉浆的黏度差异较大;所考察的5种淀粉浆的黏度拐点温度范围为40~50℃;预胶化淀粉和部分预胶化淀粉适合采用煮桨法配制淀粉浆,其他3种淀粉适合采用冲浆法配制淀粉浆。结论 作为淀粉浆使用的最佳浓度范围分别是：玉米淀粉5%~8%,可溶性淀粉6%~8%,预胶化淀粉5%~8%,部分预胶化淀粉5%~8%,SWELSTARTMWB-1 1%~5%。     

Impact of Superdisintegrants and Film Thickness on Disintegration Time of Strip Films Loaded With Poorly Water-Soluble Drug Microparticles

Although strip films are a promising platform for delivery of poorly water-soluble drug particles via slurry casting, the effect of critical material attributes, for example, superdisintegrants (SDIs) on critical quality attributes, including film disintegration time (DT), remains underexplored. A 2-level factorial design is considered to examine the impact of the SDI type (sodium starch glycolate and croscarmellose sodium), their amount, and film thickness. SDIs were used with hydroxypropyl methylcellulose (E15LV) and glycerin solutions along with viscosity matching. Fenofibrate, a model poorly water-soluble drug, was micronized and surface modified via fluid energy milling. Significant decreases in film DT, measured using 3 different methods, were observed due to the addition of SDIs. Percentage reduction in DT was a strong function of SDI amount, and thinner films disintegrated faster. Films with either higher SDI concentrations (>9%) or films under 80 μm, exhibited fast DT (<180 s, European Pharmacopeia). All thin films (50-60 μm) exhibited immediate release (>80% in 10 min). All films achieved good content uniformity, except for those with the lowest amount of SDI, attributed to insufficient viscosity and thickness nonuniformity due to the SDI. Finally, all films achieved adequate mechanical properties, notwithstanding minor negative impact of SDIs.     

复方丹参注射液联合硝苯地平治疗妊娠期高血压疾病的临床疗效观察

目的探讨复方丹参注射液联合硝苯地平治疗妊娠期高血压疾病的临床疗效,为临床治疗提供参考依据。方法选取2016年2-12月经唐山市中医医院诊治的70例妊娠期高血压疾病患者作为研究对象,应用随机数字表法进行分组,将患者均分为观察组及对照组,对照组患者单独应用硝苯地平治疗,观察组患者联合应用复方丹参注射液、硝苯地平治疗,比较两组临床治疗疗效。结果治疗前,两组患者的血压、血液黏度情况比较,差异均无统计学意义(均P>0.05);治疗后,两组患者的血压、血液黏度均有所降低,其中观察组患者的血压、血液黏度明显低于对照组,差异有统计学意义(均P<0.05)。观察组患者的并发症发生率(5.71%)明显低于对照组患者的并发症发生率(31.43%),差异有统计学意义(P<0.05);观察组治疗总有效率为94.29%,明显高于对照组的77.14%,差异有统计学意义(P<0.05)。治疗后,观察组患者血浆内皮素-1(ET-1)、血清一氧化氮(NO)、D-二聚体(D-D)及尿蛋白含量改善程度均显著优于对照组,差异均有统计学意义(均P<0.05)。结论妊娠期高血压疾病治疗中应用复方丹参注射液联合硝苯地平取得良好的效果,患者的血压得到了有效的控制,同时具有降低并发症的作用。     

肾小球疾病患者的血液流变学与临床生化关系分析

在肾小球疾病的发生及发展过程中，患者血液流变性可出现异常．我们对４０例肾小球疾病患者的血液流变学及临床生化指标检测结果表明，血液流变学指标的改变与血生化指标明显相关，现将结果报告如下．     

Influence of D- and L-glucose on erythrocytes and blood viscosity

BACKGROUND: Elevated blood glucose levels are associated with substantial morbidity and mortality. The pathomechanism behind it is not well understood. The aim of the present study was to investigate the effect of glucose on blood rheology. MATERIALS AND METHODS: Blood from healthy volunteers was incubated with various concentrations of D- and L-glucose for 1 h at 37 degrees C. Whole blood viscosity at haematocrit 45% was measured at high and low shear rate (94.5 and 0.1 s(-1)). Erythrocyte shape and volume were assessed. Haemoglobin solutions were incubated with D-glucose for up to 96 h and the viscosity was measured. RESULTS: D-glucose dissolved in H2O and diluted with isotonic NaCl, added to whole blood (additional D-glucose concentrations 0-80 mM), led to a red cell swelling and an increase in blood viscosity at low shear rate (0.1 s(-1)). This process was reversible upon removal of D-glucose. L-glucose, which is not transported into the red cell by the D-glucose-specific transport protein GLUT-1, had no effect. When D-glucose was dissolved and diluted in autologous plasma, haematocrit and viscosity remained unaffected, but L-glucose decreased both values. Incubation of a haemoglobin solution with D-glucose at 37 degrees C led to a time-dependent increase in glycosylated haemoglobin (HbA1C) up to 8%, but left the viscosity unchanged. CONCLUSION: Blood glucose tested in a wide range of concentrations did not affect blood viscosity and morphological or biophysical properties of erythrocytes.     

黄连素对子宫肌瘤大鼠模型血液黏度、子宫系数、平滑肌厚度和炎性细胞浸润的影响

目的分析黄连素对子宫肌瘤大鼠模型血液黏度、子宫系数、平滑肌厚度和炎性细胞浸润的影响。方法取32只成年SPF级SD大鼠,随机分为对照组、模型组、低剂量黄连素组、高剂量黄连素组,每组各8只。除对照组外,其余三组均给予苯甲酸雌二醇注射液+黄体酮注射液肌内注射建立子宫肌瘤模型。对照组和模型组均给予等量生理盐水,低剂量黄连素组采用黄连素10 mg/kg进行灌胃,高剂量黄连素组采用黄连素20 mg/kg进行灌胃。比较各组大鼠血液黏度、血清肿瘤坏死因子α(TNF-α)、白介素6(IL-6)、α干扰素(INF-α)、子宫重量、子宫系数和平滑肌厚度,经病理学染色观察各组大鼠子宫形态学状况。结果模型组大鼠红细胞聚集指数、血浆黏度、全血黏度均明显高于对照组,低剂量黄连素组、高剂量黄连素组大鼠红细胞聚集指数、血浆黏度、全血黏度均明显低于模型组(P<0.05)。相比对照组,模型组大鼠血清TNF-α和IL-6水平显著增高,INF-α水平显著降低(P<0.01);低剂量黄连素组和高剂量黄连素组血清TNF-α和IL-6水平均明显低于模型组,INF-α水平均明显高于模型组(P<0.01)。模型组大鼠子宫重量、子宫系数和平滑肌厚度较对照组均明显增加,低剂量黄连素组和高剂量黄连素组大鼠子宫重量、子宫系数和平滑肌厚度较模型组均明显下降(P<0.05)。相比对照组,模型组、低剂量黄连素组和高剂量黄连素组出现不同程度的炎性细胞浸润,其中高剂量黄连素组的炎症程度较轻。结论黄连素对子宫肌瘤模型大鼠具有良好的治疗效果,能降低其血液黏度、子宫系数、平滑肌厚度和炎性细胞浸润程度,作用机制可能在于黄连素具有改善大鼠体内炎性因子水平的效果。     

旋转磁场治疗激素性股骨头坏死

目的观察旋转磁场对激素性股骨头坏死相关致病环节的抑制作用，探讨其治疗股骨头坏死的机理。方法制备新西兰兔股骨头坏死动物模型，予旋转磁场（由铋铁硼永磁体为磁源的恒定磁场以8Hz频率旋转、在其上方20cm形成直径60cm的半球形磁场、表面强度在0．32～0．60T之间）处理4周（处理1个月组）和8周（处理2个月组），通过X线片和组织切片观察股骨头内部结构变化，检测其血液黏稠度、胆固醇、甘油三脂以及髋关节腔压力等指标的变化，和相应的假处理1个月组、假处理2个月组和空白对照组进行统计学分析比较。结果经旋转磁场处理后，动物模型的股骨头X线片和组织切片均显示其骨小梁形态结构显著改善，同时血液黏稠度、胆固醇、甘油三脂和髋关节腔压力下降均具显著统计学意义（P〈0．01）。结论旋转磁场可以针对股骨头坏死的主要环节，如高脂血症、血液黏稠度增加、关节腔压力增高等多方面发挥调节作用，有效治疗激素性股骨头坏死。