Real Conditions Of Use Research Articles

Study of the Cytotoxicity of a Composite of Carboxymethylcellulose (CMC) and a BioCeramic (Biphasic Calcium Phosphate-BCP) Injection for Use in Articular Cartilage Repair

The failure of organs and tissues caused by trauma and other injuries is one of the most costly of human health problems. It is estimated that 1.6 million people experience work limitations caused by osteoarthritis and related disorders, representing 8.3% of all main conditions. Joint injuries frequently lead to progressive joint degeneration and post-traumatic osteoarthritis. Articular cartilage has only a limited capacity for self-healing, mainly due to the fact that it is avascular; and once seriously damaged, articular cartilage lesions will not regenerate. There is strong evidence that cartilage lesions may lead to osteoarthritis when left untreated. Numerous animal experiments and clinical studies have shown that early biological reconstruction of circumscribed cartilage defects in the knee is superior to conservative or delayed surgical treatment. Tissue engineering has shown promising therapeutic strategies for repair or regeneration of damaged tissues. Currently, ceramic based and polymeric scaffolds have been developed to bring about the restoration of tissue functions. The bioceramics associated with water-soluble polymers have been developed as substitutes for various orthopedic applications. The objectives of this work are the processing and characterization of a composite of carboxymethylcellulose (CMC) and biphasic calcium phosphate (Biphasic Calcium Phosphate - BCP) in the form of a hydrogel, and a study of its cytotoxicity (in vitro), aimed at its application as an injectable biomaterial in order to repair the extracellular matrix of articular cartilage. The CMC and BCP were characterized by Fourier Transform Infrared Spectrometry (FTIR) and X-Ray Diffraction (XRD), X-ray fluorescence (XRF), respectively, and scanning electron microscopy (SEM) of powders and the composite. To evaluate the biological effect of the composite hydrogel, tests of cytotoxicity (MTT) and rheological tests under real conditions of use were performed. The composite of carboxymethylcellulose (CMC) and bioceramics (biphasic calcium phosphate-BCP) in the form of hydrogel showed an adequate injectability in the conditions studied, and a non-toxic response, presenting potential for use as fillers or to stimulate the healing of cartilage defects in the extracellular matrix of articular cartilage.

A linear 60 GHz 65 nm-CMOS power amplifier realization and characterization for OFDM signal

A millimeter-wave Power Amplifier (PA) based on a 65nm CMOS technology from STMicroelectronics has been designed. The targeted feature is the unlicensed band around 60 GHz suitable for wireless personal area network application (WPAN). To optimize the linearity, the PA is designed under class A biasing to have an output compression point (OCP1) close to its saturated Power (P sat). S-parameters and large signal measurement results are demonstrated and compared with electromagnetic simulations. The PA offers a P sat of 8.3 dBm, an OCP1 of 6 dBm and a gain of 6.7 dB. The die area is 0.29 mm2 with pads. Considering those results, one-tone simulations are not sufficient to characterize the linearity performances of the PA in its real conditions of use. Consequently, two-tone simulations are firstly performed. After, linearity figures of merit (FoM) are discussed applying an orthogonal frequency-division multiplexing (OFDM) modulated signal. The PA offers an adjacent channel power ratio (ACPR) of 15 dB and an error vector magnitude (EVM) of 20% at PA compression operating mode.

Analysis of Belt Weigher Accuracy Limiting Factors

In practical experience, the accuracy of coal mass flow measurement by the use of belt weigher is considerably lower than the theoretical, as the result of a number of limiting factors. The analyses that have been designed and the practical experience point to the problems occurring in the installation, maintenance, and testing of belt weighers. The weigher measurement accuracy, however, is mostly determined by the real conditions of use. This article presents a model of all the disturbing effects on the belt weigher measurement system, as the result of a systematic analysis of their influence. A few of adaptive methods for the compensation of these influences are listed together with the directions for further development.

Photodegradation of (−)-epigallocatechin-3-gallate in topical cream formulations and its photostabilization

The aim of the study was to examine the photostability of the major catechin of green tea, (−)-epigallocatechin-3-gallate (EGCG), which possesses important antioxidant and skin photoprotective properties. In order to simulate realistic conditions of use of topical preparations, the photolysis studies were performed in model creams (oil-in-water emulsions) containing 1% (w/w) EGCG and exposed to a solar simulator at an irradiance corresponding to natural sunlight. The extent of photodegradation was measured by HPLC–UV and HPLC–ESI-MS. EGCG was found to decompose by 68.9 ± 2.3%, after 1 h irradiation. Addition of the coantioxidants, vitamin E or butylated hydroxytoluene to the emulsion formulation, significantly enhanced the photolability of the catechin, the EGCG loss reached 85.7 ± 1.3% and 80.5 ± 1.4%, respectively. On the other hand, inclusion of the UVB (290–320 nm) filter, ethylhexyl methoxycinnamate in the cream produced a small but significant reduction of EGCG photodegradation to 61.0 ± 2.9%, while the UVA (320–400 nm) filter, butyl methoxydibenzoylmethane was ineffective (EGCG degradation, 67.8 ± 1.5%). A more marked decrease in the light-induced decomposition of EGCG to 51.6 ± 2.7% was achieved, under the same conditions, using the water-soluble UVB filter, benzophenone-4 (BP-4). This effect was concentration dependent, maximal EGCG photostabilization (catechin loss, 29.4 ± 2.2%) was attained in the presence of 2.1% (w/w) BP-4. Therefore, BP-4 represents a useful additive to improve the light stability of EGCG in topical formulations for skin photoprotection.

Fator de proteção solar: significado e controvérsias

The Sun Protection Factor (SPF) is the most important data to quantify the effectiveness of a sunscreen, being universally accepted. The method is based on determining the minimum erythematous dose (MED), defined as the smallest amount of energy required for triggering the erythema, in areas of protected and unprotected skin. The SPF value is then calculated as the ratio between the MED of protected and unprotected skin. The first publication of a method for determining the SPF was presented in 1978 by the U.S. FDA agency, followed by other publications of FDA and other international regulatory agencies. Although considered the reference method for quantification of sunscreen efficacy of topical products, there are controversies in literature about the method for determining the SPF and the implications of the real conditions of use in the protection achieved in practice by users.

시판 발열조끼의 주관적 착용평가

This study evaluated the convenience and heating performance of 4 heated vests on the market through a trial of the vests. Participants were four healthy men who wore the garments outside in cold temperatures typical of the garments' real conditions of use. As the results, all the participants preferred the product, having an easily operable controller in ergonomic aspects and the good insulation for keeping the body temperature. The heating performance of vests was the most important factor in selecting the best product in this test. Indeed, the vests themselves found not to be sufficiently warm in the experimental condition. Thus, heated vests with the enhanced heating performance should be developed so that temperatures in the allowed range can be safely accessed.

Multicentric, observational, transversal study to describe the clinical profile of patients with metastatic breast cancer (MBC) treated with first-line bevacizumab (TRANSBREAST): Preliminary results.

1143 Background: Following the approval of bevacizumab for the treatment of MBC, this study was devised to identify the profile of patients (pt) treated under real conditions of use, their relationship with the regime used and the MBC subtypes by their genetic signature and tolerability of treatment. Methods: Multicentric observational transversal study in 40 centers. We present the results from the first 108 pts who received at least one dose of bevacizumab. Results: Of the women treated, 98.1% were Caucasian, with a mean age of 50.7 years (30-82) and ECOG 0-1 in 88%. In terms of prior history, 3.7% suffered from cardiopathies, 11.1% vascular disorders and 4.8% had kidney pathology. Neoadjuvant or adjuvant chemotherapy (CT) was given to 88% of them. The predominant histology was infiltrating ductal (82%) and histological grade 3 (49%). Positive results for hormone receptors were found in 68.5%, of which 65% were luminal A and 3.5% luminal B; 3.5% were HER2 positive, while 28% were triple negative. The disease-free interval for patients who received adjuvant or neoadjuvant CT was greater than 12 months in 86.3%. The most frequent metastatic locations were liver (38%), bone (59%), and lung (29%). The drugs most commonly used with bevacizumab were taxanes (87%). Of the 71 pt evaluated so far, 59.2% have shown a response (95% CI: 47-71%), 8.5% complete, and 22% stable disease, with 81.7% (95% CI: 73-91) obtaining a benefit from the treatment, without differences being found between subtypes. The main grade 1-2 toxicities were arterial hypertension (17%) and bleeding (18.5%). One case of grade 3-4 toxicity (proteinuria) was detected although only 30% of patients had a urine analysis. Conclusions: Bevacizumab combined with chemotherapy is well-tolerated, safe, and effective as first-line treatment of MBC, with a clinical benefit being obtained in 81.7% of patients. The results are consistent with the data from the three phase III studies in 1L and MO19391 from the clinical practice. No significant financial relationships to disclose.

Evidence of a bacterial carbonate coating on plaster samples subjected to the Calcite Bioconcept biomineralization technique

Degradation of historical buildings is mainly due to the intrusion of water which is the main vector of pollutants. Different types of surface treatment have been proposed to avoid or limit this effect. One alternative to chemical treatments is the use of the carbonatogenesis property of some bacteria. This bacterial production has been evidenced on concrete and on limestone samples in an aqueous environment. However, the carbonate production was measured indirectly and the experimental protocol was far from real conditions of use. In this paper, with the same protocol as an industrial one, and using a surface selective investigation method, grazing incidence X-ray diffraction, we show the structural and morphological evolution of the carbonate coating produced on model plaster samples. This substrate was chosen in order to unambiguously detect the bacterial carbonate production.

Environmental assessment of ester-based lubricants after application

Goal, Scope and Background Lubricants based on renewable resources are an environmentally friendly alternative to petrochemical products due to their better ecotoxicological performance and their excellent biodegradability. To improve the technical performance of lubricants, and to reduce friction and wear, the use of additives is nowadays obligatory. The collaborative research center SFB 442 aims at developing environmentally acceptable lubricants that facilitate the avoidance of these additives by transferring their function to suitable coatings. For a complete assessment of the ecological performance of these newly developed lubricants, the whole life cycle including production, application as well as disposal and fate in the environment is studied. In the following study the focus was on the application and its influence on the environmental behavior of the lubricant. The application of lubricants leads, among other things, to the intake of metals due to abrasion from tools, work pieces or mechanical components. Previous examinations indicated a possible influence of metals on the toxicity of eluates prepared from used lubricants (Erlenkaemper et al. 2005). To clarify if the apparent toxicity of used lubricants solely results from the intake of metals, the extractability of these metals from the oil matrix is determined. By combining chemical analyses with bioassays, the bioavailability of metals that are present in the extract is estimated. To further investigate the relevance of metals on toxicity, toxic units (TU) were calculated and related to the results of the bioassays. Interactions between the metals were investigated with aqueous mixtures of metal chlorides and calculations based on the concept of concentration addition and independent action.

Acceptance and cognitive load in a clinical setting of a novel device allowing natural real-time data acquisition

Introduction This paper reports the findings of an evaluation study in the field of human–computer interaction about the use of a new data acquisition device, the digital pen. It focuses on specific aspects of the interaction between the users and the technology: the cognitive burden induced by the design of the tool in real conditions of use and its impact on user acceptance. Methodology Human cognition is embedded in a complex sociocultural world. Therefore, we opted for ethnographically informed investigations reinforced by a satisfaction survey. The work context chosen for these investigations was the emergency room triage process. Results The technology meets a high acceptance (median 3 on a [−5,5] scale) shaded by unexpected additional cognitive burdens. These burdens originate in several technological and ergonomic flaws that have been discovered during the observations. These results have been used to improve the technology. Conclusion We demonstrate the importance of this kind of field study to uncover unexpected possible sources of failure of acceptance of a new technology. Such kind of study should be held prior to the introduction of a new technology to lower the common failure rate encountered in the field of medical informatics.

Performance of lipid‐based moisture barriers in food products with intermediate water activity

AbstractNine lipid‐based barrier films (three chocolates, acetomonopalmitine, white beeswax, and four commercial blends: two acetoglycerides/beeswax blends, two hydrogenated and fractionated vegetable oils) were characterised using classical water‐related and physical properties of edible barriers, such as water vapour permeability, moisture adsorption isotherm, moisture effective diffusivity, surface hydrophobicity, firmness and solid fat content (20 °C). Classifications based on these properties were established and compared to the barrier efficiency under real conditions of use, i.e. in a model food product (cereal‐based component – intermediary aw gel). Moisture migrations were performed using self‐supported barriers (300 µm) and fitted with a predictive model based on Fick's Second Law. White beeswax and acetoglycerides enabled the best extensions of the dry‐component shelf life from 2 h to between 100 and 330 h. Moisture effective diffusivity and calculated water vapour permeability combined to a mechanical property evaluation of the barrier were more discriminating to assess the barrier efficiency in the model food than the moisture sorption and experimental water vapour permeability. The importance of combining both water‐related and physical characteristics of the barrier and the advantages of an integrated approach through the simulation of the material behaviour under its real conditions of use with the model are highlighted.

Bacterial and Fungal Counts in Hospital Air: Comparative Yields for 4 Sieve Impactor Air Samplers With 2 Culture Media

We compared the yields of 4 recently developed sieve impactor air samplers that meet international standard ISO 14698-1, using 2 growth media (tryptic soy agar and malt extract agar) in real conditions of use. Several hospital sites expected to have different densities of airborne microflora were selected in 2 hospitals. The Samplair MK2, Air Ideal, and Mas-100 samplers yielded higher bacterial counts than did the SAS Super-100 device (P<.05). No significant differences in fungal counts were noted between the 4 devices. The use of malt extract agar in addition to tryptic soy agar significantly improved the fungal yield.

A statistical monitoring approach for automotive on‐board diagnostic systems

AbstractThe current generation of vehicle models are increasingly being equipped with on‐board diagnostic (OBD) systems aimed at assessing the ‘state of health’ of important anti‐pollution subsystems and components. In order to promptly diagnose and fix quality and reliability problems that may potentially affect such complex diagnostic systems, even during advanced development prior to mass production, some vehicle prototypes undergo a testing phase under realistic conditions of use (a mileage accumulation campaign). The aim of this work is to set up a statistical tool for improving the reliability of the OBD system by monitoring its operation during the mileage accumulation campaign of a new vehicle model. A dedicated software program was developed by the authors to filter the large experimental database recorded during the mileage accumulation campaign and to extract the time series of the diagnostic indices to be analysed. A model‐based monitoring approach, using continuous time autoregressive (CAR) models for the time‐series structure and traditional control charts for the estimated residuals, is adopted. A Kalman recursion procedure for the estimation of the unknown CAR model parameters is described. An application of the proposed approach is presented for a diagnostic index related to the state of health of the oxygen sensor. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Design of a suspension of a training sulky

A design study based on a modelling approach was used to optimise the characteristics of a new concept of suspension for training sulkies. The numerical model of sulky including the suspension and, in a second stage, a mechanical model of driver, allowed the definition of technical specifications. They were used to manufacture a prototype of suspension mounted on a current production model of sulky. The prototype of suspension was then tested in the lab and in a racecourse in real conditions of use. The resulting vibration exposure was assessed from vibration measurements. It was slightly lower than the limit value enacted in the European Vibration directive (1.15 m s 2), but drastically reduced in comparison with the exposure measured on the original sulky (2.56 m s 2). The prototype and moreover the design procedure is currently in a transfer process towards sulky manufacturers.

Traitement des surinfections bronchiques: stabilité des antibiotiques dans les diffuseurs portatifs

AbstractTreatment of Bronchial Superinfections: Data Related to Stability of Antibiotics in Portable Pumps. Introduction.Given many data about the stability of antibiotics in portable pump (elastomer) are lacking, this study was designed to make a point about available data and to evaluate the stability of antibiotics when exposed to temperature within 35°C (average temperature measured in real conditions of use). Material and methodsFirst, to collect information about the stability of antibiotics in portable pump and to confront them with the local antibiotics protocols dedicated to the treatment of bronchial superinfection in patients with cystic fibrosis; second, to evaluate the stability of piperacillin associated with tazobactam at 35°C. ResultsWhile measured concentrations in tazobactam did not show significant variation during the study, piperacillin measurements showed a major reduction of concentration (up to 33%), both time and concentration related to. DiscussionSuch information must be pointed out to prescribers and patients to ensure a cold accumulator is placed in the pump can’ying-bag and to limit the duration of infusion to 24h with a single pump. ConclusionThis experimental program will keep on going with the stability study of both ticarcillin and cefsulodin in portable pump.

Energy-efficient housing for low-income students in a highly variable environment of central Argentina

Socio-economic, educational and environmental reasons have driven the building of energy-efficient dwellings for low-income students in University of La Pampa. The buildings are located in the central region of Argentina (35° 70′ of South latitude), an area of warm temperate climate. Energy conservation devices, passive solar heating, natural ventilation and solar protection were the main strategies of design. The resulting design comprised three blocks of housing with a useful floor area of 900 m 2. Two bedrooms, a dining room and essential services make up each house. Solar gains through transparent areas to the North are provided for all main spaces. Northern shading devices and metallic pergolas protect all windows in summer. In spite of high external temperature variability, the simulated performance during the design stage showed a remarkable internal thermal stability. The thermal and energy monitoring started in September 1999 and had two phases: (a) under real conditions of use and (b) during student's summer holidays (when the buildings were not inhabited). The results from the monitoring process suggest that interpretations about the building behaviour cannot be restricted to constructive issues. Useful inferences cannot be done from design and building technology only. The thermal behaviour was the result of construction, non-construction factors like dwellers habits, and their interaction. Energy saving in heating during the winter season was around 50%.

Upper gastrointestinal adverse drug reactions and cyclo-oxygenase-2 inhibitors (celecoxib and rofecoxib): a case/non-case study from the French Pharmacovigilance Database

To evaluate the gastrointestinal safety of cyclo-oxygenase-2 inhibitors under their real conditions of use. DESIGN. Case/non-case study. Adverse drug reactions (ADRs) in adults recorded in the French Pharmacovigilance Database between 25 May 2000 and 31 December 2002. Cases were all reports of "serious" oeso-gastro-duodenal ADRs (oeso-gastro-duodenal ulcers, oesophagitis, gastritis, duodenitis). Five non-cases were randomly selected for one case from all other non oeso-gastro-duodenal reports in the database after matching them for age, gender and period of occurrence. Coxib exposure was compared among cases and non-cases, with adjustment for matching factors: French Regional Pharmacovigilance Centres that collected ADRs, reporter health professional's characteristics and exposures to non-selective non-steroidal anti-inflammatory, aspirin, anticoagulant, antiplatelet and gastroprotective drugs. Included in the study were 505 cases and 2,525 non-cases. A positive association was found between occurrence of oeso-gastro-duodenal ADRs and coxib (adjusted odds ratio 14.9 [95% CI 9.3-23.7]), diclofenac (9.2 [3.8-22.2]), ibuprofen (7.3 [3.2-16.6]) or oxicam (25.3 [11.9-53.6]) use. Despite the compulsory limits of the case/non-case methodology, the present study shows that coxibs did induce "serious" gastrointestinal ADRs in real clinical practice. These results underline the need for pharmacoepidemiological studies under real conditions of use in order to verify (or not) the conclusions of clinical trials.

An investigation of rail bearing reliability under real conditions of use

The objective of the present work is to carry out a performance analysis of roller bearings used in railway ore transportation wagons. Data from 47,000 failed bearings divided in seven groups, were used to determine the failure distribution. Six groups corresponded to operation in the years 1985–1988, 1990, 1991 and one group included all the others. The failure distribution in bearings was described by the three parameter Weibull distribution. To conduct the statistical analysis it was necessary to estimate these parameters by the nonlinear regression method, because it does not require the whole group of failed bearings, and direct inference on the sample. A Monte Carlo technique was used to validate the procedure. Analytically two estimate methodologies were considered. Methodology I is a well established technique while Methodology II is an alternative approach proposed by the authors, which was inspired by a procedure used to design rail shafts. Studying the bearing failure behavior led to the following observations: based on sample inference techniques, an excessive variation was observed in the parameters that characterize the failure distribution. A dispersion of the order of 40 or 25% was found in the minimum and nominal lives when evaluated by the direct inference method or by the nonlinear regression method, respectively, and a dispersion of 17% calculated by nonlinear regression was observed for the shape parameter, β ̂ . In spite of this dispersion, it was found that the minimum lives estimated by direct inference were conservative by a factor of four, when compared to analytical methods, while estimates of the nominal life were shown to be similar to its smallest value observed in the sample groups.

Shifting the Design Philosophy of Spoken Natural Language Dialogue: From Invisible to Transparent Systems

Spoken natural language interfaces are characterized by a high degree of opacity. This characteristic leads many new users to converse with the machine on the basis of an inaccurate image of the system, which results in numerous dysfunctions and failures in the human-machine spoken dialogue. The application of the principle of transparency aims to correct this problem by enabling the system to make it “visible” (it can, so to speak, be seen “from the inside”). This report presents a study that compares two versions of the same spoken dialogue system that differ only by some of their dialogue strategies. In particular, one version of this system starts the dialogue with a recall of the main system's function followed by an open-ended prompt, while the other version only produces an open-ended prompt (What can I do for you?). Moreover, one version of this system makes explicit some possible actions in specific dialogue contexts, while the other version leaves these possible actions implicit. These strategies were compared by having a group of 28 users test them in real conditions of use. The results highlight that transparency strategies can help users in formulating simple and acceptable requests, satisfying their goals more easily while provoking less recognition and comprehension errors.

Adapting verbal protocol methods to investigate speech systems use

This paper presents a method to gather data from user interactions with a speech system. This method is based on existing verbal protocol methods usually used in Cognitive Psychology. The main aim of this method is to elicit the users’ expectations and interpretations that are formed when interacting with the system, and can impede the dialogue success when they are erroneous. This article also provides an illustration of the application of this method based on an actual study with a conversational speech system under realistic conditions of use.