Variables influencing the frictional behaviour of in vivo human skin

In the past decades, skin friction research has focused on determining which variables are important to affect the frictional behaviour of in vivo human skin. Until now, there is still limited knowledge on these variables. This study has used a large dataset to identify the effect of variables on the human skin, subject characteristics and environmental conditions on skin friction. The data are obtained on 50 subjects (34 male, 16 female). Friction measurements represent the friction between in vivo human skin and an aluminium sample, assessed on three anatomical locations. The coefficient of friction increased significantly (p<0.05) with increasing age, increasing ambient temperature and increasing relative air humidity. A significant inversely proportional relationship was found between friction and both the amount of hair present on the skin and the height of the subject. Other outcome variables in this study were the hydration of the skin and the skin temperatur

The pion form factor on the lattice at zero and finite temperature

We calculate the electromagnetic form factor of the pion in quenched lattice QCD. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the consistently O(a) improved current. We calculate the pion form factor for masses down to m_pi = 360 MeV, extract the charge radius, and extrapolate toward the physical pion mass. In the second part, we discuss results for the pion form factor and charge radius at 0.93 T_c and compare with zero temperature results.Comment: Invited talk at the Lightcone 2004 conference, Amsterdam, 16-20 August, 200

Helicity Amplitudes for Single-Top Production

Single top quark production at hadron colliders allows a direct measurement of the top quark charged current coupling. We present the complete tree-level helicity amplitudes for four processes involving the production and semileptonic decay of a single top quark: W-gluon fusion, flavor excitation, s-channel production and W-associated production. For the first three processes we study the quality of the narrow top width approximation. We also examine momentum and angular distributions of some of the final state particles.Comment: 27 pages, 7 figures, final versio

Finite element analysis of artificial hip joint movement during human activities

The range of motion of artificial hip joint during human activities, measured from the postoperative total hip arthroplasty patients, has been reported previously. There were two human activities discussed, i.e. Western-style and Japanese-style. This paper analyzes the hip joint movement during human activities, based on the measured range of motion, using finite element simulation. The Western-style activities consist of picking up, getting up and sitting, while the Japanese-style activities consist of sitting on legs with fully flexed at the knee (seiza), squatting and sitting on legs with fully flexed at the knee (zarei). The aim of this study is to investigate the probability of prosthetic impingement to occur and to calculate the von Mises stress during the activities. A three-dimensional nonlinear finite element (FE) method was used in the simulation. The acetabular liner cup positions were varied. Results show that in the Western-style activities, the picking up activity induces prosthetic impingement in a certain acetabular liner cup position, whereas in the Japanese-style activities there is no prosthetic impingement observed. However, the Japanese's Zarei activity has a critical value in the range of motion. The von Mises stresses during the prosthetic impingement have been shown and the value is higher than the yield stress of the material

Regional Economic growth and accessibility: The case of the Netherlands

Shift-share is a popular, relatively easy to apply, tool in spatial analysis. Upon its initial development and use in the 1970s the literature has shown that serious drawbacks of the shift-share technique should be noted (e.g., lack of theoretical basis, sensitivity to level of aggregation). But several solutions have been proposed, and besides, when a technique is simple and apparently useful, it will be both widely used and heavily criticized. The aim of this paper was to apply a shift- share analysis for the labour volume and value added. This was done for 40 so-called COROP-regions in the Netherlands over several subperiods of the most recent decades (1973-1993). It was shown that the development over time of the three shift-share effects for labour volume and value added were much the same. This was not only shown by means of a Geographic Information System but also statistically proved. Other relationships between the outcomes of the shift-share analysis and a few, more or less, economic variables were investigated as well. And lastly, an interesting aspect was the course of the regional growth of value added and employment over time. This development was illustrated by using a concentration-coefficient.

Awareness of dying: it needs words

Purpose: The purpose of this research is to study to what extent dying patients are aware of the imminence of death, whether such awareness is associated with patient characteristics, symptoms and acceptance of dying, and whether medical records and nurses' and family caregivers' views on patients' awareness of dying agree. Methods: Nurses and family caregivers of 475 deceased patients from three different care settings in the southwest Netherlands were requested to fill out questionnaires. The two groups were asked whether a patient had been aware of the imminence of death. Also, medical records were screened for statements indicating that the patient had been informed of the imminence of death. Results: Nurses completed questionnaires about 472 patients, family caregivers about 280 patients (response 59%). According to the medical records, 51% of patients had been aware of the imminence of death; according to nurses, 58%; according to family caregivers, 62%. Patients who, according to their family caregiver, had been aware of the imminence of death were significantly more often in peace with dying and felt more often that life had been worth living. Inter-rater agreement on patients' awareness of dying was fair (Cohen's kappa = 0.23-0.31). Conclusions: Being aware of dying is associated with acceptance of dying, which supports the idea that open communication in the dying phase can contribute to the quality of the dying process. However, views on whether or not patients are aware of the imminence of death diverge between different caregivers. This suggests that communication in the dying phase of patients is open for improvement

Improving the quality of palliative and terminal care in the hospital by a network of palliative care nurse champions: the study protocol of the PalTeC-H project

BACKGROUND: The quality of care of patients dying in the hospital is often judged as insufficient. This article describes the protocol of a study to assess the quality of care of the dying patient and the contribution of an intervention targeted on staff nurses of inpatient wards of a large university hospital in the Netherlands. METHODS/DESIGN: We designed a controlled before and after study. The intervention is the establishment of a network for palliative care nurse champions, aiming to improve the quality of hospital end-of-life care. Assessments are performed among bereaved relatives, nurses and physicians on seven wards before and after introduction of the intervention and on 11 control wards where the intervention is not applied. We focus on care provided during the last three days of life, covered in global ratings of the quality of life in the last three days of life and the quality of dying, and various secondary endpoints of treatment and care affecting quality of life and dying. DISCUSSION: With this study we aim to improve the understanding of and attention for patients’ needs, and the quality of care in the dying phase in the hospital and measure the impact of a quality improvement intervention targeted at nurses

Electromagnetic vertex function of the pion at T > 0

The matrix element of the electromagnetic current between pion states is calculated in quenched lattice QCD at a temperature of $T = 0.93 T_c$. The nonperturbatively improved Sheikholeslami-Wohlert action is used together with the corresponding ${\cal O}(a)$ improved vector current. The electromagnetic vertex function is extracted for pion masses down to $360 {\rm MeV}$ and momentum transfers $Q^2 \le 2.7 {\rm GeV}^2$.Comment: 17 pages, 8 figure

The tribological behaviour of skin equivalent materials and ex-vivo human skin during sliding contact with artificial turf

The use of synthetic materials for outdoor and indoor sport fields has increased over the last decades. Artificial turfs, commonly used on football fields, are basically infilled with recycled crumb rubber derived from old tires, the main of which are NBR (acrylonitrile butadiene rubber) and SBR (styrene-butadiene rubber) with fibers usually made of Polyethylene (PE) or Nylon. The use of these polymers for artificial turf designing purposes has caused controversy to whether their impact in human health, especially in skin abrasions during players sliding on the artificial turf. We have studied the tribological performance of different artificial human skin and real human skin against NBR, PE and Nylon 6.6 at different environmental conditions: normal conditions (25 ˚C and 50% of relative humidity) and high humidity conditions (37 ˚C and 80% of relative humidity) and forces of 2 and 4 N to achieve the association between friction and skin damage. The applied forces correspond to a range of pressures of 121 to 175 kPa and the experiments were conducted at 50 mm/s. The friction coefficient was obtained for different artificial skin samples: Lorica, Silicone L7350, pure PDMS, Cutinova and ESE (an epidermal skin equivalent developed by us), and these results were compared to those obtained from excised human skin samples obtained from healthy people after a surgery carried out at the Radboud Hospital of Nijmegen. Later on the human skin samples were analyzed with confocal microscopy and histological images to study the case of the surface properties of skin and determine any possible damage on the Stratum Corneum related to the tribological tests