| 2 | Interplay between microstructural evolution and tribo-chemistry during dry sliding of metals显示文摘Understanding the microstructural and tribo-chemical processes during tribological loading is of utmost importance to further improve the tribological behavior of metals. In this study, the friction, wear and tribo-chemical behavior of Ni with different initial microstructures(nanocrystalline, bi-modal, coarse-grained) is investigated under dry sliding conditions. In particular, the interplay be-tween frictional response, microstructural evolution and tribo-oxidation is considered. Friction tests are carried out using ball-on-disk experiments with alumina balls as counter-bodies, varying the load between 1 and 5 N. The microstructural evolution as well as the chemical reactions beneath the samples’ surface is investigated by means of cross-sections. The samples with finer microstructures show a faster run-in and lower maximum values of the coefficient of friction(COF) which can be attributed to higher oxidation kinetics and a higher hardness. It is observed that with increasing sliding cycles, a stable oxide layer is formed. Furthermore, initially coarse-grained samples show grain refinement, whereas initially finer microstructures undergo grain coarsening converging towards the same superficial grain size after 2,000 sliding cycles. Consequently, the experimental evidence supports that, irrespective of the initial microstructure, after a certain deformation almost identical steady-state COF values for all samples are achieved. | Philipp GGRÜTZMACHER Sebastian RAMMACHER Dominic RATHMANN Christian MOTZ FrankMÜCKLICH Sebastian SUAREZ | 2019 | Friction2019，7，6： | 5 |
| 9 | 瑞格列奈对餐时血糖的调节:其临床效果及对2型糖尿病患者生活方式的影响显示文摘对餐时血糖进行调节将使患者得到良好的代谢调控,并可以降低低血糖的发生,使患者进餐时间更具有性,对照研究表明,餐时血糖调节剂-瑞格列奈与磺脲类降糖药物在治疗效果上至少是相同的,但是,瑞格列奈可以显著减少低血糖的发生,然而,这些实验采用固定的剂量和进餐时间,所以瑞格列奈并没有按照最佳的方式被使用,本前瞻性研究是在日常的临床工作中进行的。目的在于探讨在2型糖尿病患者中,使用瑞格列奈进行灵活的餐时血糖调节后,临床药物疗效以及患者对该药物的耐受性。方法:德国5985名2型糖尿病患者参加了这项前瞻性研究,在治疗前以及用瑞格列奈平均治疗46天之后都接受了调查评估。治疗前,64%的患者接受常规口服抗糖尿病药物治疗,22%的患者仅接受饮食治疗,13%的患者从未接受过任何治疗。结果:总体来说,经过46天治疗后,平均HbA1C值从8.6%降至7.4%;空腹血糖浓度从183.9dl降至134.2mg/dl(10.2mmol/L降到7.4mmol/L);餐前血糖浓度从198.5mg/dl降至141.4mg/dl(11mmol/L降到7.8mmol/L);餐后两小时血糖浓度从219.3mg/dl降至153.2mg/dl(12.2mmol/L降到8.5mmol/L)。分组研究表明,在以前从未接受过治疗的患者中,以及从使用其它口服抗糖尿病药物转为使用瑞格列奈或瑞格列奈与其它药物联合治疗的患者中,瑞格列奈治疗可以使上述每一种血糖指标都有明显的改善(P<0.0001)。在研究中,患者体重有轻度下降(1.2±2.7kg)。研究中仅报道有49次低血糖事件发生,其中38例为轻度低血糖,所有这些低血糖均未留下后遗症。当患者从其它口服降糖药转为瑞格列奈后,患者认为生活方式获得了巨大解放,80%的患者认为由于能够忽略进餐,所以使用瑞格列奈治疗后可以有较大的解脱,那些认为由于固定进餐时间而感到生活方式受到限制的患者从36%减少到7%。在改变用药之前,38%的患者由于害怕发生低血糖,尽管不饿也要进餐,而在改用瑞格列奈之后,患者加餐的情况较为少见,只有10%的患者仍然沿袭这种做法。结论:瑞格列奈进行餐时血糖调节能够改善2型糖尿病患者的代谢调控,而且不会引起体重增加,还可以降低低血糖的发生。不论是以前从未接受过治疗的患者,还是从使用其它口服抗糖尿病药物较为使用瑞格列奈的患者,或者采取瑞格列奈与其他药物联合治疗的患者,均可以有相同的效果,餐时血糖治疗的方法还可以使患者的进餐时间更加灵活,因此受到大多数改用此药患者的欢迎。 | LandgralR FrankM 等 | 2001 | 中华内分泌代谢杂志2001，17，6： | 0 |
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