Evaluation of clinically relevant operating conditions for left ventricular assist device investigations.

Standardized boundary conditions for flow rate and pressure difference are currently not available for the development and certification process of ventricular assist devices. Thus, interdisciplinary studies lack comparability and quantitative assessment. Universally valid boundary conditions could be used for the application of numerical and experimental investigations and the approval procedure of ventricular assist devices. In order to define such boundaries, physiological data from INCOR® patients were evaluated. A total of 599 out of possible 627 ventricular assist device patients were analyzed regarding their cardiac demands of flow rate and pressure head. An analysis of long-term data was performed, in order to provide respective, static mean values for benchmark testing. Furthermore, the short-term data of 188 patients delivered field data-based dynamic flow and pressure curves. The results of the study revealed physiologically reasonable boundary conditions, which can be applied in numerical or experimental investigations of ventricular assist devices. For steady flow analysis, single values for flow rate (4.46 L/min) and pressure head (62 mmHg) are suggested. For the support of pulsatile and unsteady flow studies, seven typical patients and one representative dynamic curve for flow rate and pressure head are proposed.The standardized results provided in this article, can be used in favor of interdisciplinary comparability of future numerical computations or in vitro ventricular assist device tests in research, development, and approval.

Endoplasmic reticulum aminopeptidase 1 polymorphism Ile276Met is associated with atopic dermatitis and affects the generation of an HLA-C associated antigenic epitope in vitro.

BACKGROUND: Atopic dermatitis (AD) is a common inflammatory skin disease of complex aetiology, with interactions between susceptibility genes and environmental factors. We have previously described a protective effect of the KIR2DS1 gene encoding the natural killer cell receptor, whose ligands are HLA-C molecules. Here, we found an association of HLA-C*05:01 allele with AD. KIR-HLA-C interactions are affected by peptides presented by HLA-C. The generation of these peptides is strongly influenced by endoplasmic reticulum aminopeptidases 1 and 2 (ERAP1 and ERAP2). Expression and activity of ERAP molecules depend on the polymorphisms of their genes. OBJECTIVE: Possible associations of several single nucleotide polymorphisms (SNPs) in the ERAP1 and ERAP2 genes with susceptibility to AD. METHODS: Peripheral blood DNA isolation from 318 patients and 549 controls. PCR-SSO or PCR-SSP for HLA-C typing; TaqMan Genotyping Assay for ERAP typing. RESULTS: Only one SNP in the ERAP1 gene, rs26618T>C, causing the amino acid change Ile276Met, had an association with AD. To gain insight on the functional role of this SNP, we produced recombinant variants differing only at position 276 (Ile or Met) and tested their aminopeptidase activity against a N-terminally extended precursor LIVDRPVTLV of the HLA-C*05:01 epitope IVDRPVTLV. Both ERAP1 variants were able to efficiently generate the epitope, although the 276Ile allotype was able to do this about 50% faster. Furthermore, both variants were quite inefficient in further degradation of the mature epitope. Finally, we found that the effect of 276Met on susceptibility to AD was seen only in KIR2DS1-negative individuals, not protected by this KIR. CONCLUSION: Associations of HLA-C*05:01 allele and rs26618T>C (Ile276Met) ERAP1 polymorphism with AD, and a significant difference between these two ERAP1 variants in their ability to generate an epitope for the HLA-C*05:01 molecule was found.

Preliminary report: Surgical outcomes following genitoplasty in children with moderate to severe genital atypia.

INTRODUCTION: Prior studies of outcomes following genitoplasty have reported high rates of surgical complications among children with atypical genitalia. Few studies have prospectively assessed outcomes after contemporary surgical approaches. OBJECTIVE: The current study reported the occurrence of early postoperative complications and of cosmetic outcomes (as rated by surgeons and parents) at 12 months following contemporary genitoplasty procedures in children born with atypical genitalia. STUDY DESIGN: This 11-site, prospective study included children aged ≤2 years, with Prader 3-5 or Quigley 3-6 external genitalia, with no prior genitoplasty and non-urogenital malformations at the time of enrollment. Genital appearance was rated on a 4-point Likert scale. Paired t-tests evaluated differences in cosmesis ratings. RESULTS: Out of 27 children, 10 were 46,XY patients with the following diagnoses: gonadal dysgenesis, PAIS or testosterone biosynthetic defect, severe hypospadias and microphallus, who were reared male. Sixteen 46,XX congenital adrenal hyperplasia patients were reared female and one child with sex chromosome mosaicism was reared male. Eleven children had masculinizing genitoplasty for penoscrotal or perineal hypospadias (one-stage, three; two-stage, eight). Among one-stage surgeries, one child had meatal stenosis (minor) and one developed both urinary retention (minor) and urethrocutaneous fistula (major) (Summary Figure). Among two-stage surgeries, three children developed a major complication: penoscrotal fistula, glans dehiscence or urethral dehiscence. Among 16 children who had feminizing genitoplasty, vaginoplasty was performed in all, clitoroplasty in nine, external genitoplasty in 13, urethroplasty in four, perineoplasty in five, and total urogenital sinus mobilization in two. Two children had minor complications: one had a UTI, and one had both a mucosal skin tag and vaginal mucosal polyp. Two additional children developed a major complication: vaginal stenosis. Cosmesis scores revealed sustained improvements from 6 months post-genitoplasty, as previously reported, with all scores reported as good or satisfied. DISCUSSION: In these preliminary data from a multi-site, observational study, parents and surgeons were equally satisfied with the cosmetic outcomes 12 months after genitoplasty. A small number of patients had major complications in both feminizing and masculinizing surgeries; two-stage hypospadias repair had the most major complications. Long-term follow-up of patients at post-puberty will provide a better assessment of outcomes in this population. CONCLUSION: In this cohort of children with moderate to severe atypical genitalia, preliminary data on both surgical and cosmetic outcomes were presented. Findings from this study, and from following these children in long-term studies, will help guide practitioners in their discussions with families about surgical management.

Local microscopic properties and annealing effect of Rb0.85Fe1.9Se2 single crystals.

Investigation of mesoscopically phase-separated Rb0.85Fe1.9Se2 single crystals has been performed and two iron sites: nonmagnetic and magnetic ones, were observed by Mössbauer spectroscopy. The softening of the nonmagnetic one, having clearly more soft dynamics, was found to be gained further by the annealing of the single crystals at phase separation temperature, T p, leading to the reduction of size of initially separated domains and their more homogenous distribution in the tetragonal matrix of the studied sample. The magnetic Fe sites of Rb0.85Fe1.9Se2 show strong magnetic texture, indicating the perpendicular to the ab-plane orientation of the iron magnetic moments. It was found that the annealing at T p causes a systematic decrease of the isomer shift of the doublet by 0.02(1) mm s-1.

Prospective assessment of cosmesis before and after genital surgery.

INTRODUCTION: Little data exist about the surgical interventions taking place for children with disorders of sex development (DSD). Most studies that have evaluated cosmetic outcomes after genitoplasty have included retrospective ratings by a physician at a single center. OBJECTIVE: The present study aimed to: 1) describe frequency of sex assignment, and types of surgery performed in a cohort of patients with moderate-to-severe genital ambiguity; and 2) prospectively determine cosmesis ratings by parents and surgeons before and after genital surgery. STUDY DESIGN: This prospective, observational study included children aged <2 years of age, with no prior genitoplasty at the time of enrollment, moderate-to-severe genital atypia, and being treated at one of 11 children's hospitals in the United States of America (USA). Clinical information was collected, including type of surgery performed. Parents and the local pediatric urologist rated the cosmetic appearance of the child's genitalia prior to and 6 months after genitoplasty. RESULTS: Of the 37 children meeting eligibility criteria, 20 (54%) had a 46,XX karyotype, 15 (40%) had a 46,XY karyotype, and two (5%) had sex chromosome mosaicism. The most common diagnosis overall was congenital adrenal hyperplasia (54%). Thirty-five children had surgery; 21 received feminizing genitoplasty, and 14 had masculinizing genitoplasty. Two families decided against surgery. At baseline, 22 mothers (63%), 14 fathers (48%), and 35 surgeons (100%) stated that they were dissatisfied or very dissatisfied with the appearance of the child's genitalia. Surgeons rated the appearance of the genitalia significantly worse than mothers (P < 0.001) and fathers (P ≤ 0.001) at baseline. At the 6-month postoperative visit, cosmesis ratings improved significantly for all groups (P < 0.001 for all groups). Thirty-two mothers (94%), 26 fathers (92%), and 31 surgeons (88%) reported either a good outcome, or they were satisfied (see Summary Figure); there were no significant between-group differences in ratings. DISCUSSION: This multicenter, observational study showed surgical interventions being performed at DSD centers in the USA. While parent and surgeon ratings were discordant pre-operatively, they were generally concordant postoperatively. Satisfaction with postoperative cosmesis does not necessarily equate with satisfaction with the functional outcome later in life. CONCLUSION: In this cohort of children with genital atypia, the majority had surgery. Parents and surgeons all rated the appearance of the genitalia unfavorably before surgery, with surgeons giving worse ratings than parents. Cosmesis ratings improved significantly after surgery, with no between-group differences.

Adalimumab or infliximab as monotherapy, or in combination with an immunomodulator, in the treatment of Crohn's disease.

BACKGROUND: The comparative efficacy of adalimumab (ADA) and infliximab (IFX) in Crohn's disease, and the benefit of initial combotherapy with an immunomodulator, are debated. AIM: To assess the best anti-TNF treatment regimens in Crohn's disease. METHODS: We included 906 biologic-naïve Crohn's disease patients [median age, 31 years (24-41)] and performed a retrospective analysis of 1284 therapeutic exposures to ADA (n = 521) or IFX (n = 763) between 2006 and 2015. An immunomodulator was associated during the first 4-6 months (initial combotherapy) during 706 therapeutic exposures (55%). Median duration of anti-TNF therapy was 39 months (IQR 17-67). Primary outcomes were 6-month and 2-year response rates and drug survival. Logistic regression with propensity scoring and Cox proportional hazard analysis determined variables associated with outcomes. RESULTS: The response rates at 6 months and 2 years were 64% and 44% on ADA mono, 86% and 70% on ADA combo, 72% and 45% on IFX mono, and 84% and 68% on IFX combotherapy, respectively. Differences between ADA and IFX were not significant, whereas combotherapy was superior to monotherapy (P < 0.001). Drug survival was longer with combotherapy vs. monotherapy [adjusted hazard ratio 2.17 (1.72-2.70)] and not significantly different between ADA and IFX. During subsequent anti-TNF exposures, IFX combotherapy fared better than other groups regarding response rates, drug survival, disease activity, hospitalisations and abdominal surgery. CONCLUSION: In this retrospective analysis of a large tertiary centre cohort of Crohn's disease patients, ADA and IFX had similar efficacy as first line treatment, while initial combotherapy with an immunomodulator improved all outcome measures.

Assessment of colon and bladder crosstalk in an experimental colitis model using contrast-enhanced magnetic resonance imaging.

BACKGROUND: Inflammatory bowel disease (IBD) consists of two chronic remitting-relapsing inflammatory disorders in the colon referred to as ulcerative colitis and Crohn's disease (CD). Inflammatory bowel disease affects about 1.4 million Americans. 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis is a widely used model of experimental intestinal inflammation with characteristic transmural and segmental lesions that are similar to CD. METHODS: Here, we report on the use of contrast-enhanced magnetic resonance imaging (CE-MRI) to monitor in vivo bladder permeability changes resulting from bladder crosstalk following colon TNBS exposure, and TNBS-induced colitis. Changes in MRI signal intensities and histology were evaluated for both colon and bladder regions. KEY RESULTS: Uptake of contrast agent in the colon demonstrated a significant increase in signal intensity (SI) for TNBS-exposed rats (p < 0.01) compared to controls. In addition, a significant increase in bladder SI for colon TNBS-exposed rats (p < 0.001) was observed compared to saline controls. Histological damage within the colon was observed, however, bladder histology indicated a normal urothelium in rats with TNBS-induced colitis, despite increased permeability seen by CE-MRI. CONCLUSIONS & INFERENCES: Contrast-enhanced MRI was able to quantitatively measure inflammation associated with TNBS-induced colitis, and assess bladder crosstalk measured as an increase in urothelial permeability. Although CE-MRI is routinely used to assess inflammation with IBD, currently there is no diagnostic test to assess bladder crosstalk with this disease, and our developed method may be useful in providing crosstalk information between organ and tissue systems in IBD patients, in addition to colitis.

Disorders of Sex Development (DSD): Networking and Standardization Considerations.

Syndromes resulting in Disorders of Sex Development (DSD) are individually rare. Historically, this fact has hindered both clinical research and the delivery of evidence-based care. Recognizing the need for advancement, members of European and North American medical societies produced policy statements, notably the Consensus Statement on Management of Intersex Disorders, which recognize that optimal healthcare in DSD requires multidisciplinary teams in conjunction with networking of treatment centers and continued development of patient registries. This paper summarizes efforts in Europe and the U.S. toward creating networks focused on expanding discovery and improving healthcare and quality of life outcomes in DSD. The objectives and function of registry-based networks (EuroDSD/I-DSD), learning collaboratives (DSD-net), clinical outcomes research (DSD-Life), and networking hybrids (DSD-TRN) are reviewed. Opportunities for, and barriers to standardization in research and care are highlighted in light of practical considerations, for example, limitations in reliably classifying anatomic phenotypes and gaps in behavioral health staffing resources. The role of patient-reported outcomes is considered, with emphasis on integrating patient perspectives, given findings of limited agreement in outcome ratings by healthcare providers and patients. Finally, the characteristics of clinical centers likely to deliver the highest quality outcomes are discussed.

Genetic polymorphisms and expression of HLA-G and its receptors, KIR2DL4 and LILRB1, in non-small cell lung cancer.

Human leukocyte antigen-G (HLA-G) is a nonclassical HLA class I molecule absent from most normal tissues but detected in many malignant tumors. It is recognized by cells of the immune system using LILRB1, KIR2DL4 and LILRB2 receptors. We attempted to find out whether some polymorphisms of HLA-G, LILRB1 and KIR2DL4 genes are associated with susceptibility to nonsmall cell lung cancer (NSCLC). Four polymorphisms in HLA-G, i.e. -964A>G (rs1632947), -725C>G>T (rs1233334), -716T>G (rs2249863) in the promoter, and a 14 base pair insertion/deletion (14 bp indel) in the 3'-untranslated region (3'UTR), and five in LILRB1 - 5651G>A (rs41308748) in intron 14, 5717C>T L622L (rs1061684), 5724G>A E625K (rs16985478), 5774 C>A P641P (rs41548213) in exon 15, and 5806C>T (rs8101240) in 3'UTR - as well as 9620 9A/10A (rs11410751) polymorphism in exon 7 of KIR2DL4 were typed using different laboratory techniques. Only one single nucleotide polymorphism (SNP) in HLA-G (-964A>G) and one in LILRB1 (5724G>A) were found to influence the risk of NSCLC. In addition, 5724G>A was associated with protection from tumor cell infiltration of regional lymph nodes. Most importantly, we detected HLA-G and LILRB1 expression in tumor specimens, but no correlation with genetic polymorphisms was observed. HLA-G and LILRB1 protein expression levels in tumor tissue were significantly correlated with tumor stage.

Parenting Children with Disorders of Sex Development (DSD): A Developmental Perspective Beyond Gender.

Advances in therapeutics for specific conditions have contributed to a categorical psychological approach to chronic diseases that affect children. Consensus statements and clinical guidelines recognize stress associated with disorders of sex development (DSD) for patients and their caregivers - yet much remains to be learned concerning the social adjustment, mental health, and quality of life of affected children and their families. We present preliminary data on the psychosocial comorbidities of caregivers of children with DSD, including stigma, isolation, stress, anxiety, and depressive symptomatology. Evidence is offered in support of individualized psychological approaches for families according to such variables as: 1) gender of the caregiver, 2) gender of the affected child and 3) presence of genital ambiguity at birth. Development of feasible, targeted interventions to ameliorate psychosocial comorbidities among caregivers is needed to optimize social adjustment, mental health, and health-related quality of life (HRQoL) for children with DSD.

Investigation of gene-gene interactions between CD40 and CD40L in Polish multiple sclerosis patients.

CD40-CD40L interaction is necessary for the activation of both humoral and cellular immune response and has been suggested to play a role in the pathogenesis of multiple sclerosis (MS). Therefore, we analyzed the combined influence of the CD40 and CD40L variants on MS susceptibility and progression on well-defined Polish population. Our investigation revealed that CT individuals in rs1883832 locus of CD40 possessed almost 1.5-fold higher risk for MS than CC individuals (OR = 1.44; 95%CI = 1.03-2.1; p = 0.032), while this risk for TT individuals was almost 2.5-fold higher (OR = 2.36; 95%CI = 1.19-4.78; p = 0.014). Moreover, for the first time, we observed the association of CD40 gene with MS development and progression. We observed that for the rs1883832CC individuals the age at diagnosis was on average 2 years lower than for the rs1883832CT and rs1883832TT individuals (CI95% = -3.69-(-0.29); p = 0.023). Additionally, we detected that individuals with TT and CT genotypes showed lower risk of developing secondary progressive course in comparison to those with CC genotype. For rs1883832TT individuals this risk was 4-fold lower (HR = 0.24; CI95% = 0.10-0.53; p = 0.00062). Despite the fact that CD40-CD40L pathway plays a key role in development of autoimmune diseases, we were not able to detect gene-gene interactions between CD40 and CD40L polymorphisms associated with multiple sclerosis.

Application of termite nest for adsorption of Cr(VI).

This work proposes the use of tree termite nest as an adsorbent for the reduction/removal of Cr(VI) present in aqueous solution. In laboratory experiments, adsorption of Cr(VI) was sensitive to pH in the range investigated (2-5), with maximum adsorption capacity achieved at pH 2 (3.70 ± 0.04 mg g(-1), representing 93.2% removal of Cr). The termite nest was characterized by off-line pyrolysis GC/MS (py-GC/MS), infrared spectroscopy (FTIR), and electron paramagnetic resonance spectroscopy (EPR). Pyrolysis of the adsorbent produced a complex mixture of aromatic compounds, including the guaiacyl and syringilic derivatives that are characteristic of lignocellulosic materials. Infrared spectroscopy revealed deprotonation of the carboxylic acid group of the biomass with increasing pH, which was associated with a decrease in the capacity for adsorption of Cr(VI). The EPR g-factor for the termite nest samples varied between 2.0037 and 2.0038, indicating the presence of organic free radicals that were responsible for the redox reaction. A second line with g-factor values of 1.9790, only observed for the samples after contact with Cr(VI) solutions at different pH values, was assigned to Cr(III)-Cr(III) exchange coupled pairs, which explained the capacity of the adsorbent to retain a large portion of the Cr(III) ions produced after reduction of Cr(VI) to Cr(III). Fixed-bed column experiments showed that the termite nest had a maximum adsorption capacity of 18.60 mg Cr g(-1), an adsorption efficiency varying between 60.8 and 97.4%, and a desorption efficiency varying between 54.5 and 91.4%, for three successive cycles. The adsorbent presented excellent performance in the removal of chromium under acidic conditions, with the advantage that it could be regenerated and reused.

The weight of communication: The Canadian Medical Association Journal's discourse on obesity.

In this exploratory analysis, I use a Burkean dramatist approach to investigate the relatively under-examined dynamics of how medical knowledge on obesity has changed outside of the American context. I examine how, over the past forty years, Canadian medical professionals have used the Canadian Medical Association Journal to generate a field of knowledge which organizes the ways in which obesity can be described, studied and treated. I argue that since the 1970s medical professionals have been increasingly interested in the relationship between obesity and a broadly defined social environment, and that this merger is rhetorically realized in the concept of the "obesogenic environment." I suggest that the process of engaging obesity has generated rhetoric that has often been resonant with the political ideologies expressed in health policy, but that can also create opportunities for the expression of alternative social goals.

Magnetic dynamic properties of electron-doped La(0.23)Ca(0.77)MnO3 nanoparticles.

Magnetic properties of basically antiferromagnetic La(0.23)Ca(0.77)MnO(3) particles with average sizes of 12 and 60 nm have been investigated in a wide range of magnetic fields and temperature. Particular attention has been paid to magnetization dynamics through measurements of the temperature dependence of ac-susceptibility at various frequencies, the temperature and field dependence of thermoremanent and isothermoremanent magnetization originating from nanoparticles shells, and the time decay of the remanent magnetization. Experimental results and their analysis reveal the major role in magnetic behaviour of investigated antiferromagnetic nanoparticles played by the glassy component, associated mainly with the formation of the collective state formed by ferromagnetic clusters in frustrated coordination at the surfaces of interacting antiferromagnetic nanoparticles. Magnetic behaviour of nanoparticles has been ascribed to a core-shell scenario. Magnetic transitions have been found to play an important role in determining the dynamic properties of the phase separated state of coexisting different magnetic phases.

Pressure-induced enhancement of the superconducting properties of single-crystalline FeTe0.5Se0.5.

The pressure dependence, up to 11.3 kbar, of basic parameters of the superconducting state, such as the critical temperature (T(c)), the lower and the upper critical fields, the coherence length, the penetration depth, and their anisotropy, was determined from magnetic measurements performed for two single-crystalline samples of FeTe(0.5)Se(0.5). We have found pressure-induced enhancement of all of the superconducting state properties, which entails a growth of the density of superconducting carriers. However, we noticed a more pronounced increase in the superconducting carrier density under pressure than that in the critical temperature which may indicate an appearance of a mechanism limiting the increase of T(c) with pressure. We have observed that the critical current density increases under pressure by at least one order of magnitude.

Magnetic behaviour of interacting antiferromagnetic nanoparticles.

Magnetic properties of interacting La(0.2)Ca(0.8)MnO(3) nanoparticles have been investigated. The field-induced transition from antiferromagnetic (AFM) to ferromagnetic (FM) state in the La(0.2)Ca(0.8)MnO(3) bulk has been observed at exceptionally high magnetic fields. For large particles, the field-induced transition widens while magnetization progressively decreases. In small particles the transition is almost fully suppressed. The thermoremanence and isothermoremanence curves constitute fingerprints of irreversible magnetization originating from nanoparticle shells. We have ascribed the magnetic behaviour of nanoparticles to a core-shell scenario with two main magnetic contributions; one attributed to the formation of a collective state formed by FM clusters in frustrated coordination at the surfaces of interacting AFM nanoparticles and the other associated with inner core behaviour as a two-dimensional diluted antiferromagnet.

Nanometer size effect on structural and magnetic properties of La0.2Ca0.8MnO3.

Structural and magnetic properties of La0.2Ca0.8MnO3 nanoparticles with average size of 15-37 nm, prepared by the glycine-nitrate method, have been studied. Synchrotron experiments performed in the temperature range of 80-300 K have shown that a structural transition from room temperature orthorhombic Pnma to monoclinic P2(1)/m space group, associated with orbital ordering, occurs below 200 K in the studied particles. This transition observed for the largest particles of 37 nm is very close to that of bulk, as seen by similar temperature variation of lattice parameters and orthorhombic strain. The transition is highly suppressed for smaller 15 nm particles. Horizontal and vertical shifts of magnetic hysteresis loops (M(Shift) and H(EB)), displayed in a field cooled process, indicate size dependent exchange bias effect. It is also shown that M(shift) and H(EB), as well as the remanent magnetization M(r) and coercive field H(c) at low temperatures, exhibit a non-monotonic size dependence for particles around 23 nm. These effects may be attributed to the changes in uncompensated spins at the surface, anisotropy or alternatively to a transition from a multi-domain to the single domain state.

Anomalous magnetic behavior of Sm0.8Ca0.2MnO3 nanoparticles.

Magnetic properties of compacted Sm0.8Ca0.2MnO3 (SCMO) particles with average particle size of 23-100 nm, prepared by the glycine-nitrate method, have been investigated. It was found that the relative volume of the ferromagnetic phase decreases with decreasing particle size. Curves of field cooled and zero filed cooled magnetization (M(ZFC)) exhibit a bifurcation just below the Curie temperature (T(c) approximately 55-64 K) for all particles studied. The field dependence of M(ZFC) peak follows de Almeida-Thouless line. Both features are characteristic of spin-glasses (SG). Measurements of ac-susceptibility in the temperature range 5-300 K and the frequency range f = 10 Hz-10 kHz show a sharp peak for both real and imaginary components in the vicinity of T(c), apparently attributed to the Hopkinson effect. A second small peak is seemingly associated with antiferromagnetic or ferrimagnetic ordering. Though, for smaller particles both peaks depend on frequency, no shift to higher temperatures with increasing f, characteristic for SG systems, was observed. The dissimilarity in magnetic properties and dynamic characteristics observed for SCMO and for La0.8Ca0.2MnO3 nanoparticles is discussed, taking into account a difference in the width of the band and the strength of double exchange and interparticle interactions.

Environmental strategies to remove volatile aromatic fractions (BTEX) from petroleum industry wastewater using biomass.

This work investigates the potentials of peat and angico hardwood sawdust to remove BTEX (benzene, toluene, ethylbenzene, and isomers of xylene) from the produced water discharged into aquatic systems during petroleum extraction. Peat and angico sawdust samples were pyrolyzed at 500°C, and found to contain n-alkenes, n-alkanes and pentacyclic triterpenes (peat), and 4-methoxyphenol, 1,4-dimethoxyphenol and 1,3,4-trimethoxyphenol (angico sawdust). In batch experiments, the removal capacities using peat were 32.4%, 50.0%, 63.0%, 67.8%, and 61.8% for benzene, toluene, ethylbenzene, m,p-xylenes and o-xylene, respectively. This compared with removal capacities using angico sawdust of 20.2%, 36.4%, 52.8%, 57.8%, and 53.7% for these compounds respectively, demonstrating the superior performance of the peat.