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Abstract Background When developing new lower limb prostheses, prototypes are tested to obtain insights into the performance. However, large variations between research protocols may complicate establishing the potential added value of newly developed prototypes over other prostheses. Objective This review aims at identifying participant characteristics, research protocols, reference values, aims, and corresponding outcome measures used during prosthesis prototype testing on people with a transfemoral amputation. Methods A systematic search was done on PubMed and Scopus from 2000 to December 2020. Articles were included if testing was done on adults with transfemoral or knee disarticulation amputation; testing involved walking with a non-commercially available prototype leg prosthesis consisting of at least a knee component; and included evaluations of the participants’ functioning with the prosthesis prototype. Results From the initial search of 2027 articles, 48 articles were included in this review. 20 studies were single-subject studies and 4 studies included a cohort of 10 or more persons with a transfemoral amputation. Only 5 articles reported all the pre-defined participant characteristics that were deemed relevant. The familiarization time with the prosthesis prototype prior to testing ranged from 5 to 10 min to 3 months; in 25% of the articles did not mention the extent of the familiarization period. Mobility was most often mentioned as the development or testing aim. A total of 270 outcome measures were identified, kinetic/kinematic gait parameters were most often reported. The majority of outcome measures corresponded to the mobility aim. For 48% of the stated development aims and 4% of the testing aims, no corresponding outcome measure could be assigned. Results indicated large inconsistencies in research protocols and outcome measures used to validate pre-determined aims. Conclusions The large variation in prosthesis prototype testing and reporting calls for the development of a core set of reported participant characteristics, testing protocols, and specific and well-founded outcome measures, tailored to the various aims and development phases. The use of such a core set can give greater insights into progress of developments and determine which developments have additional benefits over the state-of-the-art. This review may contribute as initial input towards the development of such a core set.

Tailoring interventions to the individual has been hypothesized to improve treatment efficacy. Personalization of target-specific underlying mechanisms might improve treatment effects as well as adherence. Data-driven personalization of treatment, however, is still in its infancy, especially concerning the integration of multiple sources of data-driven advice with shared decision-making. This study describes an innovative type of data-driven personalization in the context of StayFine, a guided app-based relapse prevention intervention for 13- to 21-year-olds in remission of anxiety or depressive disorders (n = 74). Participants receive six modules, of which three are chosen from five optional modules. Optional modules are Enhancing Positive Affect, Behavioral Activation, Exposure, Sleep, and Wellness. All participants receive Psycho-Education, Cognitive Restructuring, and a Relapse Prevention Plan. The personalization approach is based on four sources: (1) prior diagnoses (diagnostic interview), (2) transdiagnostic psychological factors (online self-report questionnaires), (3) individual symptom networks (ecological momentary assessment, based on a two-week diary with six time points per day), and subsequently, (4) patient preference based on shared decision-making with a trained expert by experience. This study details and evaluates this innovative type of personalization approach, comparing the congruency of advised modules between the data-driven sources (1–3) with one another and with the chosen modules during the shared decision-making process (4). The results show that sources of data-driven personalization provide complementary advice rather than a confirmatory one. The indications of the modules Exposure and Behavioral Activation were mostly based on the diagnostic interview, Sleep on the questionnaires, and Enhancing Positive Affect on the network model. Shared decision-making showed a preference for modules improving positive concepts rather than combating negative ones, as an addition to the data-driven advice. Future studies need to test whether treatment outcomes and dropout rates are improved through personalization.

This study presents a generic OpenSim musculoskeletal model of people with an osseointegrated unilateral transfemoral amputation wearing a generic prosthesis. The model, which consists of seventy-six musculotendon units and two ideal actuators at the knee and ankle joints of the prosthesis, is tested by designing an optimal control strategy that guarantees the tracking of experimental amputee data during level-ground walking while finding the actuators' torques and minimizing the muscle forces. The model can be made subject-specific and, as such, is able to reproduce the kinematics and dynamics of both healthy and amputee subjects. The model provides a tool to analyze the biomechanics of level-ground walking and to understand the contribution of the muscles and of the prosthesis' actuators. The proposed OpenSim musculoskeletal model is released as support material to this study.

BackgroundThe European Society of Cardiology (ESC) guidelines for the management of adult congenital heart disease (ACHD) recommend screening in patients at risk for arrhythmic events. However, the optimal mode of detection is unknown.MethodsBaseline and follow-up data of symptomatic ACHD patients who received an implantable loop recorder (ILR) or who participated in a smartphone based single-lead electrocardiogram study were collected. The primary endpoint was time to first detected arrhythmia.ResultsIn total 116 ACHD patients (mean age 42 years, 44% male) were studied. The ILR group (n = 23) differed from the smartphone based single-lead electrocardiogram group (n = 93) in having a greater part of males and had more severe CHD and (near) syncope as qualifying diagnosis. In the smartphone based single-lead electrocardiogram group history of arrhythmia and palpitations were more frequent (all p < 0.05). Monitoring was performed for 40 and 79 patient-years for the ILR- and smartphone based single-lead electrocardiogram group, respectively. Arrhythmias occurred in 33 patients with an equal median time for both groups to first arrhythmia of 3 months (HR of 0.7, p = 0.81). Furthermore, atrial fibrillation occurred most often (n = 16) and common therapy changes included medication changes (n = 7) and implantation of pacemaker or Implantable Cardioverter Defibrillator (ICD) (N = 4). Symptoms or mode of detection were not a determinant of the first event.ConclusionNon-invasive smartphone based single-lead electrocardiogram monitoring could be an acceptable alternative for ILR implantation in detecting arrhythmia in symptomatic ACHD patients in respect to diagnostic yield, safety and management decisions, especially in those without syncope.

Introduction Youth in remission of depression or anxiety have high risks of relapse. Relapse prevention interventions may prevent chronicity. Aim of the study is therefore to (1) examine efficacy of the personalised StayFine app for remitted youth and (2) identify high-risk groups for relapse and resilience.Method and analysis In this Dutch single-blind parallel-group randomised controlled trial, efficacy of app-based monitoring combined with guided app-based personalised StayFine intervention modules is assessed compared with monitoring only. In both conditions, care as usual is allowed. StayFine modules plus monitoring is hypothesised to be superior to monitoring only in preventing relapse over 36 months. Participants (N=254) are 13–21 years and in remission of depression or anxiety for >2 months. Randomisation (1:1) is stratified by previous treatment (no treatment vs treatment) and previous episodes (1, 2 or >3 episodes). Assessments include diagnostic interviews, online questionnaires and monitoring (ecological momentary assessment with optional wearable) after 0, 4, 12, 24 and 36 months. The StayFine modules are guided by certified experts by experience and based on preventive cognitive therapy and ingredients of cognitive behavioural therapy. Personalisation is based on shared decision-making informed by baseline assessments and individual symptom networks. Time to relapse (primary outcome) is assessed by the Kiddie Schedule for Affective Disorders and Schizophrenia-lifetime version diagnostic interview. Intention-to-treat survival analyses will be used to examine the data. Secondary outcomes are symptoms of depression and anxiety, number and duration of relapses, global functioning, and quality of life. Mediators and moderators will be explored. Exploratory endpoints are monitoring and wearable outcomes.Ethics, funding and dissemination The study was approved by METC Utrecht and is funded by the Netherlands Organisation for Health Research and Development (636310007). Results will be submitted to peer-reviewed scientific journals and presented at (inter)national conferences.Trial registration number NCT05551468; NL8237.

Abstract Background After transfemoral amputation, many hours of practice are needed to re-learn walking with a prosthesis. The long adaptation process that consolidates a novel gait pattern seems to depend on cerebellar function for reinforcement of specific gait modifications, but the precise, step-by-step gait modifications (e.g., foot placement) most likely rely on top-down commands from the brainstem and cerebral cortex. The aim of this study was to identify, in able-bodied individuals, the specific modulations of cortical rhythms that accompany short-term gait modifications during first-time use of a dummy prosthesis. Methods Fourteen naïve participants walked on a treadmill without (one block, 4 min) and with a dummy prosthesis (three blocks, 3 × 4 min), while ground reaction forces and 32-channel EEG were recorded. Gait cycle duration, stance phase duration, step width, maximal ground reaction force and, ground reaction force trace over time were measured to identify gait modifications. Independent component analysis of EEG data isolated brain-related activity from distinct anatomical sources. The source-level data were segmented into gait cycles and analyzed in the time–frequency domain to reveal relative enhancement or suppression of intrinsic cortical oscillations. Differences between walking conditions were evaluated with one-way ANOVA and post-hoc testing (α = 0.05). Results Immediate modifications occurred in the gait parameters when participants were introduced to the dummy prosthesis. Except for gait cycle duration, these modifications remained throughout the duration of the experimental session. Power modulations of the theta, mu, beta, and gamma rhythms, of sources presumably from the fronto-central and the parietal cortices, were found across the experimental session. Significant power modulations of the theta, beta, and gamma rhythms within the gait cycle were predominately found around the heel strike of both feet and the swing phase of the right (prosthetic) leg. Conclusions The modulations of cortical activity could be related to whole-body coordination, including the swing phase and placing of the prosthesis, and the bodyweight transfer between legs and arms. Reduced power modulation of the gamma rhythm within the experimental session may indicate initial motor memories being formed. Better understanding of the sensorimotor processes behind gait modifications may inform the development of neurofeedback strategies to assist gait rehabilitation.

Photolyases are flavoenzymes responsible for light-driven repair of carcinogenic crosslinks formed in DNA by UV exposure. They possess two non-covalently bound chromophores: flavin adenine dinucleotide (FAD) as a catalytic center and an auxiliary antenna chromophore that harvests photons and transfers solar energy to the catalytic center. Although the energy transfer reaction has been characterized by time-resolved spectroscopy, it is strikingly important to understand how well natural biological systems organize the chromophores for the efficient energy transfer. Here, we comprehensively characterized the binding of 8-hydroxy-7,8-didemethyl-5-deazariboflavin (8-HDF) to Xenopus (6–4) photolyase. In silico simulations indicated that a hydrophobic amino acid residue located at the entrance of the binding site dominates translocation of a loop upon binding of 8-HDF, and a mutation of this residue caused dysfunction of the efficient energy transfer in the DNA repair reaction. Mutational analyses of the protein combined with modification of the chromophore suggested that Coulombic interactions between positively charged residues in the protein and the phenoxide moiety in 8-HDF play a key role in accommodation of 8-HDF in the proper direction. This study provides a clear evidence that Xenopus (6–4) photolyase can utilize 8-HDF as the light-harvesting chromophore. The obtained new insights into binding of the natural antenna molecule will be helpful for the development of artificial light-harvesting chromophores and future characterization of the energy transfer in (6–4) photolyase by spectroscopic studies. [ABSTRACT FROM AUTHOR]

Environmental chamber studies are widely employed to investigate atmospheric chemistry and aerosol formation. However, the large surface area-to-volume ratio of a chamber leads to effects that need to be accounted for in order to apply the results of chamber studies to the ambient atmosphere. These include, but are not limited to, gas-wall partitioning and particle deposition to walls, both of which can impact quantification of reaction products. Here, a low-cost vaporizer was developed to provide a means to rapidly create well-characterized organic vapors and aerosol particles inside the chamber. This in situ approach eliminates the losses to surfaces that can occur when organic gases or particles are created in a device outside the chamber and then transported inside through tubing, thus providing a simple means for achieving quantitative addition. Thermally stable volatile organic compounds can be added to the chamber within ∼1 min, which allows for accurate measurements of gas-wall partitioning timescales and equilibrium using gas chromatography. The vaporizer can also be used to create low-volatility organic aerosol particles with a mean diameter of ∼150 nm and selectable mass concentration as low as 5 µg m−3 via homogeneous nucleation within a few minutes. Such an aerosol can be used to calibrate or evaluate the performance of instruments such as the scanning mobility particle sizer in laboratory and field studies. Copyright © 2020 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

A systematic study was conducted on the effect of a nitrate functional group on secondary organic aerosol (SOA) products and yields from reactions of C10 alkyl nitrate isomers with OH radicals in the presence of NOx. The 1- through 5-decyl nitrate isomers were synthesized from their corresponding alcohols, reacted in an environmental chamber, and the precursors and SOA were analyzed using online and offline techniques. SOA products were analogous to those formed from similar reactions of the C10n-alkane (decane), but with an additional nitrate group. The SOA yield was highest when the nitrate group was on the terminal carbon and decreased monotonically from 0.51 to 0.50, 0.44, 0.28, and 0.15 as it moved toward the center of the molecule, at which point it was similar to that from decane. The explanation for this trend, which is supported by results of calculations performed using a kinetics model, involves a combination of the effects of the nitrate group on product vapor pressures and reaction branching ratios. In general, although the nitrate group lowers the vapor pressures of products relative to the corresponding products of the decane reaction, thus enhancing gas-to-particle partitioning and SOA formation, as it moves toward the center of the molecule it also alters the branching ratios for reaction pathways so as to enhance the formation of more volatile products. The results are compared with those from similar studies on ketone and alcohol isomers to gain a more comprehensive understanding of the effects of functional groups on SOA composition and yields. Copyright © 2020 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Thermal desorption methods are widely used in the aerosol community to obtain information on particle volatility, and are often coupled with mass spectrometry to separate chemical components prior to analysis. One of the challenges of using these methods is that it is not yet clear how different components respond to temperature, in particular whether they desorb intact or decompose by reversible or irreversible reactions prior to desorption. In this study, we analyzed the thermal desorption behavior of four major classes of oligomers: hemiacetals, acetals, ethers, and esters, which are potentially present in secondary organic aerosol (SOA) and are primarily formed through particle-phase accretion reactions. The results show that when all four of these oligomers are desorbed in our thermal desorption particle beam mass spectrometer at ∼160 °C on millisecond timescales (real-time analysis) they reach the ionization region as the intact oligomer. This is also true for acetal, ether, and ester oligomers desorbed at much lower temperatures on timescales of tens of minutes, whereas hemiacetal oligomers decompose reversibly to the original alcohol and aldehyde monomers. A key factor that influences the desorption behavior of oligomers appears to be whether reversible decomposition occurs by unimolecular rearrangement or whether it involves hydrolysis, and thus requires water that may be lost from particles during heating and thus not available for reversible decomposition prior to desorption. The results should aid others in interpreting thermal desorption analyses, and in extracting information about the linkages that bind oligomers and the types of accretion reactions by which they were formed. Copyright © 2019 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Thermal desorption aerosol mass spectrometers (TDAMSs) with electron ionization are widely used for quantitative analysis of aerosol chemical composition, and the ionization efficiency of evolved gas molecules from aerosol particles is an important parameter for such analysis. We performed laboratory experiments using a custom-made TDAMS to investigate the key factors affecting ionization efficiency. Ammonium chloride (NH4Cl) and ammonium iodide (NH4I) were used as test compounds because their thermal decomposition products are expected to be simple (dominated by ammonia (NH3) and hydrogen halide (HX)). The ion signals originating from NH3 and HX were measured by altering the position of the ionizer relative to the vaporization point. The ratio of ion signal from NH3 to that from HX increased with increasing divergence angle of evolved gas plumes, which suggests that the angular distribution of gas molecules could be an important factor affecting the ionization efficiency. Copyright © 2018 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Black carbon (BC)-containing particles are the most strongly light absorbing aerosols in the atmosphere. Measurements of BC are challenging because of its semi-empirical definition based on physical properties and not chemical structure, the complex and continuously changing morphology of the corresponding particles, and the effects of other particulate components on its absorption. In this study, we compare six available commercial continuous instruments measuring BC using biomass burning aerosol. The comparison involves a Soot Particle Aerosol Mass Spectrometer (SP-AMS), a Single-Particle Soot Photometer (SP2), an aethalometer, a Multiangle Absorption Photometer (MAAP), and a blue and a green photoacoustic extinctiometer (PAX). An SP-AMS collection efficiency equal to 0.35 was measured for this aerosol system. The corrected SP-AMS BC mass measurements agreed within 6% with the SP2 refractory BC mass values. Two regimes of behavior were identified for the optical instruments corresponding to high and low organic/BC ratio. The mass absorption cross-sections (MAC) measured varied from 26% to two times the instrument default values depending on the instrument and the regime. The presence of high organic aerosol concentration in this system can lead to overestimation of the BC mass by the optical instruments by as much as a factor of 2.7. In general, the discrepancy among the BC measurements increased as the organic carbon content of the BC-containing particles increased. © 2018 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Highly oxidized multifunctional compounds (HOMs) formed through gas-phase reactions are thought to account for a significant fraction of the secondary organic aerosol (SOA) formed in low-nitric oxide (NO) environments. HOMs are known to be peroxide-rich and unstable in SOA, however, and their fate once they partition into particles is not well understood. In the study reported here, we identified particle-phase reactions and decomposition products for an α-alkoxy hydroperoxyaldehyde that served as a convenient model for HOMs, and also quantified rate and equilibrium constants for cyclic peroxyhemiacetal formation and the effects of particle acidity and relative humidity on reaction products and timescales for decomposition of peroxide-containing compounds. Sulfuric acid increased the rate of acetal formation and subsequent peroxide decomposition, but the effect was eliminated when aqueous seed particles were used in humid air, indicating that organic/aqueous phase separation can affect the ability of strong acids to catalyze these and other reactions in SOA. The results will be useful for understanding and predicting the atmospheric fate of organic peroxides and the effects of their particle-phase reactions on SOA composition. Copyright © 2018 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Primary immune thrombocytopenia (ITP) is an autoimmune disorder that is characterized by low platelet count. Glucocorticoids (GCs) resistance is a great challenge in the treatment of ITP. P-glycoprotein (P-gp) is a widely studied protein, which is associated with drug resistance. However, in ITP, the functional activity and immune regulation mechanism of P-gp remain uncertain. In this study, we evaluated the expression and functional activity of P-gp in different lymphocyte subsets, explored the correlation between P-gp function and GCs resistance and investigated the role of P-gp in ITP pathogenesis. Results indicated that the functional activity and mRNA level of P-gp were significantly higher in GCs-nonresponsive patients than in GCs-responsive patients with ITP. However, these differences in P-gp were only significant in CD8+ T cells. P-gp function was related to disease activity rather than GCs therapy. P-gp was involved in secreting granzyme B and perforin, maintaining autoreactive lymphocytes survival and enhancing autologous platelets lysis in ITP. In conclusion, over-functional P-gp might play an important role in the pathogenesis of ITP and induce GCs resistance in nonresponsive ITP patients. The blockage of P-gp could be a promising therapeutic approach for GCs-resistant patients with ITP. [ABSTRACT FROM AUTHOR]

Modern animal breeding programs are largely based on biotechnological procedures, including AI and embryo transfer technology. Recent breakthroughs in reproductive technologies, such as somatic cell nuclear transfer and in vitro embryo production, and their combination with the emerging molecular genetic tools, will further advance progress and provide new opportunities for livestock breeding. This is urgently needed in light of the global challenges such as the ever-increasing human population, the limited resources of arable land, and the urgent environmental problems associated with farm animal production. Here, we focus on genomic breeding strategies and transgenic approaches for making farm animals more feed efficient. Based on studies in the mouse and rat model, we have identified a panel of genes that are critically involved in the regulation of feed uptake and that could contribute toward future breeding of farm animals with reduced environmental impact. We anticipate that genetically modified animals will play a significant role in shaping the future of feed-efficient and thus sustainable animal production, but will develop more slowly than the biomedical applications because of the complexity of the regulation of feed intake and metabolism. [ABSTRACT FROM AUTHOR]

Aerosol particles have significant effects on a number of important atmospheric processes and phenomena including atmospheric chemistry, visibility, cloud formation, precipitation, climate and human health. A large fraction of this particulate matter is secondary organic aerosol (SOA), which is formed by gas-to-particle conversion of volatile organic compounds (VOC) emitted to the atmosphere from biogenic and anthropogenic sources. The physical and chemical processes by which SOA is formed are complex and are not sufficiently well-understood to provide adequate understanding and predictions regarding the role of this material in the atmospheric system. This review describes and illustrates the fundamental components of the SOA formation process using results from systematic experimental and modelling studies of the reactions of two major classes of VOC emissions, alkanes and alkenes, with the dominant atmospheric oxidant, OH radicals, under conditions representative of a polluted atmosphere. In particular, the presentation draws from studies aimed at elucidating the effects of molecular structure including carbon number, chain branching and C=C double bonds on the reaction kinetics, products and mechanisms and their subsequent impact on SOA formation. The simple concepts drawn from the presented results provide a useful framework for understanding the chemistry of SOA formation from more complex reactions and for identifying critical areas for future research. [ABSTRACT FROM AUTHOR]

There is growing awareness that heterogeneous reactions may be important in the atmospheric formation of secondary organic aerosols (SOA). Here, we report on the investigation of a series of recently identified heterogeneous reactions that convert 1,4-hydroxycarbonyls, a major product of alkane oxidation, to cyclic hemiacetals and then dihydrofurans in the particle-phase. Through these reactions, saturated 1,4-hydroxycarbonyls are converted to more reactive, unsaturated dihydrofurans, which can evaporate and react rapidly with atmospheric oxidants such as OH radicals, NO3radicals, or O3. In order to investigate the conversion process quantitatively, a model was developed based on a proposed mechanism that includes gas-phase and heterogeneous reactions, as well as gas–particle partitioning. This model was used to simulate the time profiles of products formed from OH radical-initiated reactions of C11–C17n-alkanes in the presence of NOx, for comparison with profiles of particle-phase cyclic hemiacetals measured during environmental chamber reactions of the same alkanes using a thermal desorption particle beam mass spectrometer. Results showed that the particle-phase isomerization of 1,4-hydroxycarbonyls to cyclic hemiacetals was fast in dry air, with a reactive uptake coefficient of at least 0.5. The lifetime for the subsequent particle-phase dehydration of cyclic hemiacetals to dihydrofurans was ∼15 min. The addition of water vapor (relative humidity ∼50%) slowed the conversion process, apparently by neutralizing adsorbed HNO3that is thought to catalyze the reactions. Simulations performed with model parameters obtained from the experiments indicate that for typical atmospheric aerosol mass and oxidant concentrations and sufficiently acidic particles, 1,4-hydroxycarbonyls will be almost entirely converted to dihydrofurans in less than a day in both clean and polluted areas, whereas in the presence of neutralized particles the conversion may be minor. The outcome that occurs could have a significant impact on reaction products and SOA formation. [ABSTRACT FROM AUTHOR]

Continual advances in the ability to produce transgenic animals make it likely that such animals will become important components of animal agriculture. The full benefit of the technology, and justification of its initial cost outlay, will be dependent on the establishment within these animals of new traits not easily achievable by other means. Potential applications include enhanced nutrient digestibility with reduced fecal losses, significantly altered milk composition with superior nutritional properties, and enhanced disease resistance. Our goal is to enhance mastitis resistance of dairy cows by enabling the cells of the mammary gland to secrete additional antibacterial proteins. Proof of concept has been obtained through experimentation with a transgenic mouse model. Three lines of mice were developed that produce varying levels of lysostaphin in their milk. This protein has potent antistaphylococcal activity and its secretion into milk confers substantial resistance to infection caused by intramammary challenge with Staphylococcus aureus, a major mastitis pathogen. Additional antibacterial proteins are being sought that will complement lysostaphin. A potential benefit of transgenic application of antibacterial proteins is the concomitant sparing in the agricultural use of antibiotics currently used as human therapeutics. Antibacterial proteins, such as lysostaphin, are not typically used as injectable or oral therapeutics because of immune-mediated or digestive destruction of their activity. In contrast, the immune system of transgenic animals will not consider the transgenic protein as being foreign. In addition we are exploring the potential of involution or mastitis responsive promoter elements for use in subsequent transgenic experiments designed to restrict lysostaphin production to these important time points. It is anticipated that genomics will play a role in unveiling candidate genes whose promoter elements will enable desired temporal expression patterns. The transgenic approach to insertion of new genetic material into agriculturally important animals is feasible but requires extensive prior evaluation of the transgene and transgene product in model systems. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined the efficacy of using somatic cells from goat milk for dynamic studies of gene expression in the mammary gland. Materials and methods used in the study; Results and discussion.

Investigates the molecular aspects of hepatobiliary transport. Generation of bile flow; Basolateral transport systems; Canalicular transport systems; Mechanisms of regulation.

Presents information on a study which identified nonylphenol ethoxylate (NPE) as a major urinary multidrug resistant substrate that indicates renal P-glycoprotein may be responsible for eliminating a variety of xenobiotics. Experimental procedures of the study; Purification of urinary NPE; Chemical identification of urinary NPE.