8 resultados para Solid separation problems
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
We performed 124 measurements of particulate matter (PM(2.5)) in 95 hospitality venues such as restaurants, bars, cafés, and a disco, which had differing smoking regulations. We evaluated the impact of spatial separation between smoking and non-smoking areas on mean PM(2.5) concentration, taking relevant characteristics of the venue, such as the type of ventilation or the presence of additional PM(2.5) sources, into account. We differentiated five smoking environments: (i) completely smoke-free location, (ii) non-smoking room spatially separated from a smoking room, (iii) non-smoking area with a smoking area located in the same room, (iv) smoking area with a non-smoking area located in the same room, and (v) smoking location which could be either a room where smoking was allowed that was spatially separated from non-smoking room or a hospitality venue without smoking restriction. In these five groups, the geometric mean PM(2.5) levels were (i) 20.4, (ii) 43.9, (iii) 71.9, (iv) 110.4, and (v) 110.3 microg/m(3), respectively. This study showed that even if non-smoking and smoking areas were spatially separated into two rooms, geometric mean PM(2.5) levels in non-smoking rooms were considerably higher than in completely smoke-free hospitality venues. PRACTICAL IMPLICATIONS: PM(2.5) levels are considerably increased in the non-smoking area if smoking is allowed anywhere in the same location. Even locating the smoking area in another room resulted in a more than doubling of the PM(2.5) levels in the non-smoking room compared with venues where smoking was not allowed at all. In practice, spatial separation of rooms where smoking is allowed does not prevent exposure to environmental tobacco smoke in nearby non-smoking areas.
Resumo:
Solid organ transplant recipients (SOTR) have an increased risk of skin cancer due to their long-term immunosuppressive state. As the number of these patients is increasing, as well as their life expectancy, it is important to discuss the screening and management of skin cancer in this group of patients. The role of the dermatologist, in collaboration with the transplant team, is important both before transplantation, where patients are screened for skin lesions and the individual risk for skin cancer development is assessed, and after transplantation. Posttransplant management consists of regular dermatological consultations (the frequency depends on different factors discussed below), where early skin cancer screening and management, as well as patient education on sun protective behavior is taught and enforced. Indeed, SOTR are very sensitive to sun damage due to their immunosuppressive state, leading to cumulative sun damage which results in field cancerization with numerous lesions such as in situ squamous cell carcinoma, actinic keratosis and Bowen's disease. These lesions should be recognized and treated as early as possible. Therapeutic options discussed will involve topical therapy, surgical management, adjustment of the patient's immunosuppressive therapy (i.e. reduction of immunosuppression and/or switch to mammalian target of rapamycin inhibitors) and chemoprevention with the retinoid acitretin, which reduces the recurrence rate of squamous cell carcinoma. The dermatological follow-up of SOTR should be integrated into the comprehensive posttransplant care.
Resumo:
Carnitine is an amino acid derivative that plays a key role in energy metabolism. Endogenous carnitine is found in its free form or esterified with acyl groups of several chain lengths. Quantification of carnitine and acylcarnitines is of particular interest for screening for research and metabolic disorders. We developed a method with online solid-phase extraction coupled to high-performance liquid chromatography and tandem mass spectrometry to quantify carnitine and three acylcarnitines with different polarity (acetylcarnitine, octanoylcarnitine, and palmitoylcarnitine). Plasma samples were deproteinized with methanol, loaded on a cation exchange trapping column and separated on a reversed-phase C8 column using heptafluorobutyric acid as an ion-pairing reagent. Considering the endogenous nature of the analytes, we quantified with the standard addition method and with external deuterated standards. Solid-phase extraction and separation were achieved within 8 min. Recoveries of carnitine and acylcarnitines were between 98 and 105 %. Both quantification methods were equally accurate (all values within 84 to 116 % of target concentrations) and precise (day-to-day variation of less than 18 %) for all carnitine species and concentrations analyzed. The method was used successfully for determination of carnitine and acylcarnitines in different human samples. In conclusion, we present a method for simultaneous quantification of carnitine and acylcarnitines with a rapid sample work-up. This approach requires small sample volumes and a short analysis time, and it can be applied for the determination of other acylcarnitines than the acylcarnitines tested. The method is useful for applications in research and clinical routine.
Resumo:
BACKGROUND: Many studies confirm that noncompliance or poor compliance is one of the great problems in health care as it results in waste of resources and funds. METHODS: This overview includes literature on heart, liver, and kidney transplants with emphasis on heart transplantation in adult and pediatric transplant patients and addresses the following variables as potential predictors of postoperative compliance problems: demographic variables (age, marital status, gender) psychological variables (anxiety, denial) psychiatric disorders (major depression, anxiety, and personality disorders), poor social support, pretransplant noncompliance, obesity, substance abuse, and health-related variables (distance from transplant center, indication for transplantation, required pretransplant assist device). Relevant studies on these topics that were conducted up to 1999 are included and discussed in this overview. The most important results are presented in tables. RESULTS: Unfortunately, there has not been any systematic and comprehensive review of the literature on predictors of noncompliance in organ transplant patients so far. With organ transplantation noncompliance impairs both life quality and life span as it is a major risk factor for graft rejection episodes and is responsible for up to 25% of deaths after the initial recovery period. Therefore, it might be assumed that well-informed transplant patients are a highly motivated group whose compliance is just as high. This is not the case. However, even when graft loss means loss of life as in heart or liver transplantation, noncompliance occurs. To best select potential organ recipients, it would be ideal if patients who are very likely to show noncompliant behavior could be identified already before being transplanted. CONCLUSION: The literature overview shows the necessity of preoperative psychosocial screening regarding predictors for posttransplant noncompliance.
Resumo:
BACKGROUND Infectious diseases after solid organ transplantation (SOT) are one of the major complications in transplantation medicine. Vaccination-based prevention is desirable, but data on the response to active vaccination after SOT are conflicting. METHODS In this systematic review, we identify the serologic response rate of SOT recipients to post-transplantation vaccination against tetanus, diphtheria, polio, hepatitis A and B, influenza, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitides, tick-borne encephalitis, rabies, varicella, mumps, measles, and rubella. RESULTS Of the 2478 papers initially identified, 72 were included in the final review. The most important findings are that (1) most clinical trials conducted and published over more than 30 years have all been small and highly heterogeneous regarding trial design, patient cohorts selected, patient inclusion criteria, dosing and vaccination schemes, follow up periods and outcomes assessed, (2) the individual vaccines investigated have been studied predominately only in one group of SOT recipients, i.e. tetanus, diphtheria and polio in RTX recipients, hepatitis A exclusively in adult LTX recipients and mumps, measles and rubella in paediatric LTX recipients, (3) SOT recipients mount an immune response which is for most vaccines lower than in healthy controls. The degree to which this response is impaired varies with the type of vaccine, age and organ transplanted and (4) for some vaccines antibodies decline rapidly. CONCLUSION Vaccine-based prevention of infectious diseases is far from satisfactory in SOT recipients. Despite the large number of vaccination studies preformed over the past decades, knowledge on vaccination response is still limited. Even though the protection, which can be achieved in SOT recipients through vaccination, appears encouraging on the basis of available data, current vaccination guidelines and recommendations for post-SOT recipients remain poorly supported by evidence. There is an urgent need to conduct appropriately powered vaccination trials in well-defined SOT recipient cohorts.
Resumo:
Liver transplantation recipients, like other solid organ transplantation recipients, have an increased risk of dermatologic problems due to their long-term immunosuppression and benefit from pre-and post-transplantation screenings, and management by a dermatologist and dermatologic care should be integrated into the comprehensive, multidisciplinary care of liver transplantation recipients [1,2]. Cutaneous findings include aesthetic alterations, infections, precancerous lesions, and malignancies. The severity of skin alterations ranges from benign, unpleasant changes to life-threatening conditions [3-5]. In addition to skin cancer diagnosis and management, visits with a dermatologist serve to educate and improve the patient's sun-protection behavior. Among all solid organ transplantations, liver transplantation requires the least amount of immunosuppression, sometimes even permitting its complete cessation [6]. As a result, patients who have undergone liver transplantation tend to have fewer dermatologic complications compared with other solid organ transplantation recipients [7]. However, due to the large volume of the liver, patients undergoing liver transplantation receive more donor lymphocytes than kidney, heart, or lung transplantation recipients. Because of the immunosuppression, the transplanted lymphocytes proliferate and rarely trigger graft-versus-host-disease [8,9]. This topic will provide an overview of dermatologic disorders that may be seen following liver transplantation. A detailed discussion of skin cancer following solid organ transplantation and the general management of patients following liver transplantation are discussed separately. (See "Development of malignancy following solid organ transplantation" and "Management of skin cancer in solid organ transplant recipients" and "Long-term management of adult liver transplant recipients".)
Resumo:
On the orbiter of the Rosetta spacecraft, the Cometary Secondary Ion Mass Analyser (COSIMA) will provide new in situ insights about the chemical composition of cometary grains all along 67P/Churyumov–Gerasimenko (67P/CG) journey until the end of December 2015 nominally. The aim of this paper is to present the pre-calibration which has already been performed as well as the different methods which have been developed in order to facilitate the interpretation of the COSIMA mass spectra and more especially of their organic content. The first step was to establish a mass spectra library in positive and negative ion mode of targeted molecules and to determine the specific features of each compound and chemical family analyzed. As the exact nature of the refractory cometary organic matter is nowadays unknown, this library is obviously not exhaustive. Therefore this library has also been the starting point for the research of indicators, which enable to highlight the presence of compounds containing specific atom or structure. These indicators correspond to the intensity ratio of specific peaks in the mass spectrum. They have allowed us to identify sample containing nitrogen atom, aliphatic chains or those containing polyaromatic hydrocarbons. From these indicators, a preliminary calibration line, from which the N/C ratio could be derived, has also been established. The research of specific mass difference could also be helpful to identify peaks related to quasi-molecular ions in an unknown mass spectrum. The Bayesian Positive Source Separation (BPSS) technique will also be very helpful for data analysis. This work is the starting point for the analysis of the cometary refractory organic matter. Nevertheless, calibration work will continue in order to reach the best possible interpretation of the COSIMA observations.