周铣过程中加工误差预测新模型

研究铣削加工过程中加工误差的预测及控制策略是进行加工质量控制的核心环节,对于实现加工过程的高效化和精密化至关重要。针对刀具柔性较大的铣削加工过程,以周铣加工过程中的刀具变形及刀齿轨迹计算为基础,建立一种新的加工误差预测模型。该模型从铣削力的预测和刀具变形的计算出发,采用圆弧近似方法求解各刀齿的运动轨迹,然后将各刀齿轨迹离散,通过计算各离散点处所有刀齿轨迹的最小值获得加工误差。与现有方法相比,该建模方法的显著优点体现在两点:一方面,建模过程较完整地揭示了铣削加工中加工误差的形成机理;另一方面,由于考虑了刀齿轨迹对加工误差的影响,模型的预测结果能够反映已加工表面的形貌。模型的有效性通过一系列铣削试验得到了验证。     

Further observations and review of numerical simulations of sheet metal punching

Vibratory problems occurring during peripheral milling of thin-walled structures affect the quality of the finished part and, to a lesser extent, the tool life and the spindle life. Therefore, it is necessary to be able to limit these problems with a suitable choice of cutting conditions. The stability lobes theory makes it possible to choose the appropriate cutting conditions according to the dynamical behaviour of the tool or the part. We introduce the dynamical behaviour variation of the part with respect to the tool position in order to determine optimal cutting conditions during the machining process. This generalization of the classical lobes diagram leads us to a 3D lobes diagram construction. These computed results are compared with real experiments of down-milling of thin-walled structures.     

Urban [IM]plants Tactics for Recombining Landscape and Collective Space in Bonheiden,Belgium

Bonheiden, in the province of Antwerp in Belgium, lies in a region known for its exceptional natural beauty. Though the surrounding rural setting has remained protected this has often been to the detriment of urban life, as the built environment has been subject to a process of banal suburbanisation. Els Verbakel and Elie Derman explain how they propose to turn this situation around by creating public spaces that use the town's ‘original landscape as the base material’. Copyright © 2008 John Wiley & Sons, Ltd.     

职业性受照人员的稳定性染色体畸变观察

对日本原爆受照生存者的大量染色体畸变分析结果表明,残存于受照者外周血淋巴细胞中的染色体畸变主要是稳定性畸变(相互易位、倒位及缺失),且畸变率与剂量之间有一定的关系~([1,2])。原爆受照人群所接受的是一次性照射;而对于那些在较长时间中连续或多次受小剂量照射的职业性工作人员,其染色体漪变是否也以稳定性畸变为主?畸变率与累积剂量之间是否有一定关系?这在国内外文献中尚未见报道。最近我们对一核工厂部分长期从事放射性工作的职工进行了稳定性畸变的分析,并对畸变率与累积剂量关系作了初步探讨。     

Differential mRNA expression in peripheral blood is associated with oral squamous cell carcinoma: Recent advances and future challenges

Oral squamous cell carcinoma (OSCC) is a malignant tumor triggered by the accumulation of multiple gene mutations in oral epithelial cells. Different OSCC-related biomarkers have been reported in circulation in the peripheral blood that support the occurrence and development of OSCC. Recent advances in high-throughput and highly sensitive detection methods have overcome the limitation of the low concentration of most peripheral blood biomarkers. Hence, blood biomarker detection has become an efficient screening tool for the early diagnosis of OSCC. The growing data available in public cancer and gene databases have provided new foundations for OSCC research. In particular, the identification of OSCC biomarkers using bioinformatic tools has shed new light on the underlying mechanisms as well as on the genetic landscape of OSCC. More recently, mRNA targeting therapies have emerged as valuable anticancer treatment strategies, as they allow for the regulation of the expression of certain functional proteins to reverse genetic abnormalities or induce tissue repair. Thus, mRNA-targeting therapies can be used to regulate the expression of antigens, antibodies, or cellular receptors by immune cells. Particularly, anti-cancer cellular immunotherapy carrying specific mRNAs has attracted significant attention in OSCC treatment. Here, we review the present knowledge on the role of peripheral blood mRNAs in the diagnosis, treatment, development, and prognosis of OSCC. Moreover, we address future research prospects of mRNAs in the peripheral blood in OSCC and the opportunities and challenges that may arise in future clinical therapeutic applications.     

Strategies to Overcome the Barrier of Ischemic Microenvironment in Cell Therapy of Cardiovascular Disease

The transplantation of various immune cell types are promising approaches for the treatment of ischemic cardiovascular disease including myocardial infarction (MI) and peripheral arterial disease (PAD). Major limitation of these so-called Advanced Therapy Medicinal Products (ATMPs) is the ischemic microenvironment affecting cell homeostasis and limiting the demanded effect of the transplanted cell products. Accordingly, different clinical and experimental strategies have been evolved to overcome these obstacles. Here, we give a short review of the different experimental and clinical strategies to solve these issues due to ischemic cardiovascular disease.     

Ground Beef High in Total Fat and Saturated Fatty Acids Decreases X Receptor Signaling Targets in Peripheral Blood Mononuclear Cells of Men and Women

We hypothesized that consumption of saturated fatty acids in the form of high‐fat ground beef for 5 weeks would depress liver X receptor signaling targets in peripheral blood mononuclear cells (PBMC) and that changes in gene expression would be associated with the corresponding changes in lipoprotein cholesterol (C) concentrations. Older men (n = 5, age 68.0 ± 4.6 years) and postmenopausal women (n = 7, age 60.9 ± 3.1 years) were assigned randomly to consume ground‐beef containing 18% total fat (18F) or 25% total fat (25F), five patties per week for 5 weeks with an intervening 4‐week washout period. The 25F and 18F ground‐beef increased (p < 0.05) the intake of saturated fat, monounsaturated fat, palmitic acid, and stearic acid, but the 25F ground‐beef increased only the intake of oleic acid (p < 0.05). The ground‐beefs 18F and 25F increased the plasma concentration of palmitic acid (p < 0.05) and decreased the plasma concentrations of arachidonic, eicosapentaenoic, and docosahexaenic acids (p < 0.05). The interventions of 18F and 25F ground‐beef decreased very low‐density lipoprotein C concentrations and increased particle diameters and low‐density lipoprotein (LDL)‐I‐C and LDL‐II‐C concentrations (p < 0.05). The ground‐beef 25F decreased PBMC mRNA levels for the adenosine triphosphate (ATP) binding cassette A, ATP binding cassette G1, sterol regulatory element binding protein‐1, and LDL receptor (LDLR) (p < 0.05). The ground‐beef 18F increased mRNA levels for stearoyl‐CoA desaturase‐1 (p < 0.05). We conclude that the increased LDL particle size and LDL‐I‐C and LDL‐II‐C concentrations following the 25F ground‐beef intervention may have been caused by decreased hepatic LDLR gene expression.     

Near peripheral motion detection threshold correlates with self-reported failures of attention in younger and older drivers

Motion contrast thresholds for 0.4 cycle/degree drifting Gabor stimuli were assessed at 15° eccentricity in the right and left visual fields for 16 younger drivers (ages 24-42), and 15 older drivers (ages 65-84), using a temporal two-alternative forced choice staircase procedure. Two self-report questionnaires that assess failures of attention while driving—the Driver Perception Questionnaire (DPQ5), and an abridged Aging Driver Questionnaire (ADQ15)—were administered. The three UFOV^® subtests of attention and processing speed were also administered. Mean peripheral motion contrast threshold (PMCT) of older drivers was significantly higher than that of younger drivers. When controlling for age, PMCT thresholds correlated significantly with both DPQ5 and ADQ15 while the UFOV^® subtests were found not to correlate with PMCT results. The potential value of the PMCT as an assessment of drivers’ hazard detection capacity is discussed.     

Near peripheral motion contrast threshold predicts older drivers’ simulator performance

Our group has previously demonstrated that peripheral motion contrast threshold (PMCT) is significantly associated with self-reported accident risk of older drivers (questionnaire assessment), and with Useful Field of View^® subtest 2 (UFOV2). It has not been shown, however, that PMCT is significantly associated with driving performance. Using the method of descending limits (spatial two-alternative forced choice) we assessed motion contrast thresholds of 28 young participants (25–45), and 21 older drivers (63–86) for 0.4 cycle/degree drifting Gabor stimuli at 15° eccentricity and examined whether it was related to performance on a simulated on-road test and to a measure of visual attention (UFOV^® subtests 2 and 3). Peripheral motion contrast thresholds (PMCT) of younger participants were significantly lower than older participants. PMCT and UFOV2 significantly predicted driving examiners’ scores of older drivers’ simulator performance, as well as number of crashes. Within the older group, PMCT correlated significantly with UFOV2, UFOV3, and age. Within the younger group, PMCT was not significantly related to either UFOV^® scores or age. Partial correlations showed that: substantial association between PMCT and UFOV2 was not age-related (within the older driver group); PMCT and UFOV2 tapped a common visual function; and PMCT assessed a component not captured by UFOV2. PMCT is potentially a useful assessment tool for predicting accident risk of older drivers, and for informing efforts to develop effective countermeasures to remediate this functional deficit as much as possible.     

Transformative innovation policy or how to escape peripheral policy paradox in European research peripheral countries

The research peripheral countries (RPCs) are faced with the need to provide transformative change for long term sustainable development with scarce research and development resources which rests upon strengthening science base and the transformative innovation policy focused on societal and environmental challenges. The European Commission's proposal of a new recovery instrument – the Next Generation EU, incorporating the Recovery and Resilience Facility as a key instrument - is focused on green, sustainable, and digital economies, paving the way for a shift from the standard science, technology, and innovation (STI) policy towards transformative innovation policies which foster innovation focused on systematic change and sustainable socio-technical systems.This research seeks to understand the ways in which STI policy can contribute to the economic resilience and sustainable development of research peripheral countries and how STI policies can respond to new innovation policy paradigms, avoiding Europeanisation of STI policies and, ultimately, a peripheral policy paradox. Overcoming of the periphery paradox in STI policies requires unorthodox policy solutions to avoid inefficient replication of policy measures from advanced countries which pertain to science – industry cooperation to foster high tech industries and frontier research.This research proposes a new STI policy approach, based on interactions and interdependencies between standard STI policies for fostering scientific research and science-industry cooperation through transformative innovation policies. This policy allows for an experimental approach to policy-making, finding a way to best suit the national socio-economic context for the gradual replacement of the established socio-technical regime towards sustainable transitions. The fourth component of the new STI policy approach is the concept of the mission-oriented policy, which draws on frontier knowledge and large investments. Both new policy paradigms are discussed in order to highlight the pros and cons of their application in RPCs with regards to research capacities, socio-economic regimes/landscapes, and societal challenges.