数字化的另一面

你的客户看见的是一双帮助的手,还是漠然转身后冷冷的背影?谁没有过噩梦般客户体验?记得Lily Tomlin的接线员Ernestine曾经不可一世地说:“我们是电话公司,我们不需要客户关怀。”这样的态度应该打上封条,陈列在客户服务发展历史博物馆里,但是很多时候,它还存在着,投射出滥用信息技术带来的更加恶劣的后果。     

Dynamic crack growth across an interface

The growth of a crack first in an elastic solid, then across an interface and into an elastic-viscoplastic solid is analyzed numerically. The analyses are carried out within a framework where the continuum is characterized by two constitutive relations; one that relates stress and strain in the bulk material, the other relates the traction and separation across a specified set of cohesive surfaces. Crack initiation, crack growth and crack arrest emerge naturally as outcomes of the imposed loading, without any ad hoc assumptions concerning crack growth or crack path selection criteria. Full transient analyses are carried out using two characterizations of strain rate hardening for the viscoplastic solid; power law strain rate hardening and a combined power law-exponential relation that gives rise to enhanced strain rate hardening at high strain rates. Results are presented for two values of interface strength. For the higher strength interface the crack grows straight through the interface into the elastic–viscoplastic solid, while for the lower strength interface the crack deflects into the interface. This revised version was published online in July 2006 with corrections to the Cover Date.     

On information and communication technology and production cost in construction industry: evidence from the Netherlands

The interplay between information and communication technology (ICT) and the competitiveness of construction firms is considered. More specifically, the question is whether firms that invest in information and communication technology have a production cost advantage. The economics literature hypothesizes that ICT brings about a production cost advantage, as ICT brings flexibility and improves the planning, organization and control of work. To test this proposition for the construction industry, a production cost function allowing for the inclusion of ICT is formulated. Using statistical nearest-neighbour matching methods it is possible to identify the effect of ICT on production costs thereby controlling for economic moderators. Data from a sample of Dutch construction firms reveal that those firms that installed ICT capital do have a production cost advantage. The results indicate further that firms need a minimum level of ICT capital to fully benefit from its production cost advantage.     

Comparison of intracellular accumulation and cytotoxicity of free mTHPC and mTHPC-loaded PLGA nanoparticles in human colon carcinoma cells

The second generation photosensitizer mTHPC was approved by the European Medicines Agency (EMA) for the palliative treatment of advanced head and neck cancer in October 2001. It is known that mTHPC possesses a significant phototoxicity against a variety of human cancer cells in vitro but also exhibits dark toxicity and can cause adverse effects (especially skin photosensitization). Due to its poor water solubility, the administration of hydrophobic photosensitizer still presents several difficulties. To overcome the administration problems, the use of nanoparticles as drug carrier systems is much investigated. Nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) have been extensively studied as delivery systems into tumours due to their biocompatibility and biodegradability. The goal of this study was the comparison of free mTHPC and mTHPC-loaded PLGA nanoparticles concerning cytotoxicity and intracellular accumulation in human colon carcinoma cells (HT29). The nanoparticles delivered the photosensitizer to the colon carcinoma cells and enabled drug release without losing its activity. The cytotoxicity assays showed a time- and concentration-dependent decrease in cell proliferation and viability after illumination. However, first and foremost mTHPC lost its dark toxic effects using the PLGA nanoparticles as a drug carrier system. Therefore, PLGA nanoparticles are a promising drug carrier system for the hydrophobic photosensitizer mTHPC.     

Self-perceived unmet health care needs of persons enrolled in HIV care

This study investigated the actual growth rate of 30 low stage operable non-small cell lung carcinomas, including disease-free surviving and deceased patients. The actual growth rate was defined as the cell production rate and was calculated from the growth fraction and the cell cycle time of each tumor at the time of surgical resection. The growth fraction was assessed by the Ki67 index while the cell cycle time was assumed to be reflected by the AgNORs content in the cells positive for Ki67. AgNORs content was evaluated by means of image analysis of double-stained AgNOR-Ki67 tissue section. The actual growth rate did not discriminate between the disease-free surviving and deceased patients but the AgNORs content in Ki67 cells correlated with the survival time of those patients who died of the tumor. Patients expressing a small AgNORs content, which might indicate a long cell cycle, may die but later; patients with a high AgNORs content, which might indicate a short cell cycle, die early or will survive. A twilight curve was derived from this data and might provide new prognostic indicators.     

The machining of sintered bronze

Orthogonal machining experiments have been conducted on specimens of sintered bronze. At low porosities and low depths of cut, a continuous chip is formed as a result of compaction and shear local to the tip of the tool. At higher porosities, and larger depths of cut, discontinuous chips form due to alternate compaction of the chip and brittle fracture. The transition occurs when the depth of cut is about 0.6 times the size of the plastic zone size associated with brittle fracture.     

Environmental assessment in early process development

A short‐cut method for environmental assessment during process development is presented. The method can deal with data uncertainties in early phases, includes all relevant environmental impacts, and is simple and easy to apply. Therefore, it can be used in early phases of process development. The environmental relevance of each substance is represented by the Environmental Factors. These factors are derived from 14 impact categories, where each compound is classified using an ABC methodology. The impact categories are then grouped into six impact groups: Resources, Grey Input, Component Risk, Organisms, Air and Water/Soil. From these, input and output environmental factors are deduced. This factor is combined with mass balance data to yield a number of indices that can be used to optimize the environmental performance of a process in an integrated manner. The method is applied to three case studies: a comparison of chemical and biotechnological production of 6‐aminopenicillanic acid, a comparison of two process alternatives in the enzymatic production of α‐cyclodextrin and the development of a new process for the fermentative production of pyruvate. Copyright © 2004 Society of Chemical Industry