太阳能热水系统在医院洗浴热水供应中的应用

文章通过太阳能热水系统与热媒换热系统、空气源热泵热水机组系统联合应用于山东省某医院洗浴热水系统中的实例,论述了系统的组成和工作原理,并分析其经济性。     

药品生产车间空调系统运行形式的选择

新版GMP规范对药品生产车间洁净级别、微生物指标等多项控制方面均有要求上的提高,由此带来了空调系统能耗加大的客观情况。为了解决这个问题,提出药品生产车间应当广泛采用新风预处理一次回风系统来代替再热式一次回风系统的方法,主要通过减少空调再热负荷来取得空调系统总体节能的效果,并通过一系列模型、数据和论证说明该方法具有适用性和经济性。     

Dentinal tubule penetration and root canal cleanliness following ultrasonic activation of intracanal‐heated sodium hypochlorite

This study investigated the effect of ultrasonic activation of intracanal‐heated sodium hypochlorite (NaOCl) on its dentinal tubular penetration and root canal cleanliness in vitro. In experiment 1, mandibular premolars were randomly allocated to three groups (n = 8): group A, ultrasonic activation; group B, ultrasonic activation of intracanal‐heated NaOCl and group C, syringe‐and‐needle irrigation. Penetration of the fluorescent‐labelled NaOCl was investigated using light microscopy. In experiment 2, mandibular premolars were randomly allocated to group B or C (n = 10), for histological analysis of the remaining pulp tissue and debris. Data were statistically analysed using Kruskal–Wallis and Mann–Whitney tests (P = 0.05). The highest penetration of NaOCl was observed in group B, followed by group A (P < 0.05). Group B showed significantly less amount of debris than group C (P < 0.05). Dentinal tubule penetration of NaOCl and root canal cleanliness were significantly improved by ultrasonic activation of intracanal‐heated NaOCl.     

Reduction of implant RF heating through modification of transmit coil electric field

In this work, we demonstrate the possibility to modify the electric‐field distribution of a radio frequency (RF) coil to generate electric field‐free zones in the body without significantly altering the transmit sensitivity. Because implant heating is directly related to the electric‐field distribution, implant‐friendly RF transmit coils can be obtained by this approach. We propose a linear birdcage transmit coil with a zero electric‐field plane as an example of such implant‐friendly coils. When the zero electric‐field plane coincides with the implant position, implant heating is reduced, as we demonstrated by the phantom experiments. By feeding RF pulses with identical phases and shapes but different amplitudes to the two orthogonal ports of the coil, the position of the zero electric‐field plane can also be adjusted. Although implant heating is reduced with this method, a linear birdcage coil results in a whole‐volume average specific absorption rate that is twice that of a quadrature birdcage coil. To solve this issue, we propose alternative methods to design implant‐friendly RF coils with optimized electromagnetic fields and reduced whole‐volume average specific absorption rate. With these methods, the transmit field was modified to reduce RF heating of implants and obtain uniform transmit sensitivity . Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.     

充气式加温毯的不同使用方式在婴幼儿颅面重建术中保温效果的比较

【】 目的 探讨充气式加温毯不同使用方式应用于婴幼儿颅面重建术的保温效果。 方法 选择择期全身麻醉下行颅面重建术患儿50例,随机分为两组,铺垫式组(A组)和覆盖式组(B组),每组25例。记录围手术期患儿的肛温(T)、MAP、HR,术中的出血量,手术结束时PT、 APTT、TT,术后的自主呼吸恢复时间、拔管时间、完全清醒时间、苏醒期的不良反应。 结果 与T0时比较：A组患儿在T2和T3时的MAP、HR和T均明显降低(P<0．05);与A组相比,B组患儿在T2和T3时的MAP、HR和T均明显升高(P<0．05);与A组相比,B组患儿的术中出血量明显减少(P<0．05);B组患儿的PT、APTT、TT均明显低于A组(P<0．05);与A组相比,B组患儿手术结束后到呼吸恢复时间、手术结束后到拔管时间、手术结束后到送回病房的时间均明显减少 (P<0．05);与A组相比,B组患儿术后寒颤和苏醒延迟发生率明显降低(P<0．05)。 结论 覆盖式使用充气式加温毯更能有效地预防婴幼儿颅面重建术中低体温的发生。     

Experimental Investigation of the Performance of a Hybrid Self-Healing System in Porous Asphalt under Fatigue Loadings

Self-healing asphalt, which is designed to achieve autonomic damage repair in asphalt pavement, offers a great life-extension prospect and therefore not only reduces pavement maintenance costs but also saves energy and reduces CO₂ emissions. The combined asphalt self-healing system, incorporating both encapsulated rejuvenator and induction heating, can heal cracks with melted binder and aged binder rejuvenation, and the synergistic effect of the two technologies shows significant advantages in healing efficiency over the single self-healing method. This study explores the fatigue life extension prospect of the combined healing system in porous asphalt. To this aim, porous asphalt (PA) test specimens with various healing systems were prepared, including: (i) the capsule healing system, (ii) the induction healing system, (iii) the combined healing system and (iv) a reference system (without extrinsic healing). The fatigue properties of the PA samples were characterized by an indirect tensile fatigue test and a four-point bending fatigue test. Additionally, a 24-h rest period was designed to activate the built-in self-healing system(s) in the PA. Finally, a damaging and healing programme was employed to evaluate the fatigue damage healing efficiency of these systems. The results indicate that all these self-healing systems can extend the fatigue life of porous asphalt, while in the combined healing system, the gradual healing effect of the released rejuvenator from the capsules may contribute to a better induction healing effect in the damaging and healing cycles.     

Localized heating characteristics of hyperthermia using a reentrant cavity

An applicator based on a reentrant cavity with excellent localized heating characteristics is proposed in order to treat deep tumours localized in the head and neck. Numerical and experimental analyses of the applicator, which produces an electromagnetic field distribution required for this type of localized heating, are performed. A simple and clear procedure for achieving localized heating requires applicator miniaturization. However, miniaturization causes an increase in the resonant frequency and leads to the degradation of the characteristics for heating deep tissue. Therefore, it is proposed that dielectrics be inserted into the applicator and the resonant frequency be reduced. From the results of the numerical analysis and experimental examination, it is shown that a deep region of 100–120 mm around the centre of a phantom can be heated.     

A detailed microscopic study of the changes in the aorta of experimental model of postmenopausal rats fed with repeatedly heated palm oil

Hypercholesterolaemia, increase in lipid peroxidation and hyperhomocysteinaemia may contribute to the pathogenesis of atherosclerosis. This study was performed to examine the effects of repeatedly heated palm oil mixed with 2% cholesterol diet on atherosclerosis in oestrogen-deficient postmenopausal rats. Ovariectomy causes disruption of tunica intima layer of the rat aorta simulating a postmenopausal condition in females. Twenty-four ovariectomized female Sprague–Dawley rats were divided into four groups. The control group received 2% cholesterol diet without palm oil. A diet with 2% cholesterol content fortified with fresh, once-heated and five-times-heated palm oil was given to the other treatment groups. The rats were sacrificed at the end of 4 months of study and the aortic arch tissue was processed for histomorphometry and electron microscopy. On observation, there was disruption of the intimal layer of the ovariectomized rat aorta. There was no obvious ultrastructural change in the aorta of the rats fed with fresh palm oil. The ultrastructural changes were minimal with once-heated palm oil, in which there was a focal disruption of the endothelial layer. The focal disruption was more pronounced with five-times-heated palm oil. The results of this study show that the ingestion of fresh palm oil may have a protective effect on the aorta but such a protective action may be lost when the palm oil is repeatedly heated. The study may be clinically important for all postmenopausal women who are susceptible to atherosclerosis.