Effect of simple interventions on the performance of a miniature MFC fed with fresh urine

The aim of the present study is to enhance the performance of a microbial fuel cell (MFC) design by making simple interventions. Specifically, terracotta “t” and mullite “m” ceramics are tested as membranes while carbon veil and carbon cloth are used as electrodes. In the case of “m” cylinders different dimensions are examined (m: ID 30 mm x height 11.5 mm; sm: ID 18 mm x height 18 mm). The units operated continuously with urine as the feedstock. The best performing is the sm type (60–100 μW), followed by the t type (40–80 μW) and the m type (20–40 μW). Polarisation experiments indicated that activated carbon on the anode enhances the power output (t: 423 μW, sm: 288 μW). Similarly, the increase of the surface area and the addition of stainless steel mesh on the cathode improves the power performance for the “sm” and the “t” units. Furthermore, it is shown that the design with the smaller internal diameter, performs better and is more stable through time.     

液液萃取-气相色谱法测定尿液中的可卡因

目的:建立人体尿液中可卡因的快速提取及气相色谱-氢火焰离子化(GC-FID)检测方法。方法:用0.05 mol/L碳酸钠-碳酸氢钠缓冲溶液调节尿液pH9.5,提取溶剂:氯仿∶异丙醇=9∶1(体积比),液-液萃取10 min,气相色谱分析。结果:方法的平均回收率为84%,检出限50ng/mL,线性范围0.1～15μg/mL,精密度小于5.47%。结论:该方法可快速、准确进行可卡因滥用者的尿液分析。     

套管结晶器定期除垢强化介质传热效率

105HI型套管结晶器是针对络合反应条件吸收反应热量等特点为尿素脱蜡装置设计的专用反应器。在大温差的换热过程中极易结垢,长时间使用后严重影响换热效果,降低换热效率,同时因热量不均匀而影响产品质量。在相同的生产负荷下,采用定期除垢方法可大幅提高换热效率,增加低温水在结晶器中的停留时间,有利于提高产品质量和收率,大幅降低能耗。     

Urinary phthalate monoesters and endometriosis in infertile Japanese women

Phthalates may act as an estrogen and are a potential risk factor for estrogen-related diseases such as endometriosis. We assessed the association between phthalate exposure and endometriosis in 166 consecutive women who presented at a university hospital for consultation regarding infertility. The subjects were interviewed and provided a urine specimen prior to a laparoscopic diagnosis of endometriosis. They were then categorized by the severity of endometriosis as controls (stages 0-I) and cases (stages II-IV). Urinary concentrations of the phthalate metabolites monoethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate, and mono(2-ethyl-5-hydroxyhexyl) phthalate were measured in 57 cases and 80 controls using high-performance liquid chromatography isotope-dilution tandem mass spectrometry. Adjusted odds ratios for endometriosis in relation to dichotomized individual phthalate metabolites (standardized for creatinine) were calculated. No significant association between endometriosis and any urinary creatinine-adjusted phthalate monoester was seen. Adjusted odds ratio (95% confidence interval) for higher dichotomized MEHP by endometriosis was 1.57 (0.74-3.30). No monotonic trend was seen in urinary creatinine-adjusted concentration of phthalate metabolites by endometriosis stage (p = 0.23-0.90). Our results do not support the hypothesis that higher urinary concentrations of phthalate metabolites are associated with the risk of endometriosis in infertile Japanese women.     

1H-NMR metabolic profiling of human neonatal urine

Object: The measurement of different urine components and their changes over time may provide comprehensive and early information about perinatal metabolic processes and physiological changes. We hypothesized that ¹ H−NMR-spectroscopy generating a complex spectral profile without pre-selection of urinary metabolites could identify metabolites determining the neonatal physiological status and discriminating between different metabolic states. Materials and Methods: We studied spot urine of three groups of neonates (healthy term-born, term-born with non-specific bacterial infections, and preterm neonates) for the first 6 days of life using ¹ H−NMR-spectroscopy. In the group of healthy neonates metabolites changing were identified and their excretion patterns compared between groups. Results: Six metabolites indicating physiological changes were identified: N-methylnicotinamide (NAD ⁺-pathway), formate, hippurate, betaine (kidney development), taurine (neuronal development), and bile acids (hepatic clearance). While the dynamic changes over the first 6 days were the same for all metabolites in both groups of term-born neonates, the excretion of N-methylnicotinamide and taurine was significantly higher in preterm neonates compared to healthy term neonates and neonates with bacterial infections from the third day after birth (P < 0.05). Conclusion: Urine analysis using ¹ H−NMR-spectroscopy could identify markers for perinatal metabolic changes. Further studies have to clarify if the proposed physiological interpretation will correlate with long-term physiological development.     

Non-targeted metabolomic approach reveals urinary metabolites linked to steroid biosynthesis pathway after ingestion of citrus juice

Citrus juice intake has been highlighted because of its health-promoting effects. LC–MS based metabolomics approaches are applied to obtain a better knowledge on changes in the concentration of metabolites due to its dietary intake and allow a better understanding of involved metabolic pathways. Eight volunteers daily consumed 400 mL of juice for four consecutive days and urine samples were collected before intake and 24 h after each citrus juice intake. Urine samples were analysed by nanoHPLC-q-TOF, followed by principal component analysis (PCA) and Student’s t-test (p < 0.05). PCA showed a separation between two groups (before and after citrus juice consumption). This approach allowed the identification of four endocrine compounds (tetrahydroaldosterone-3-glucuronide, cortolone-3-glucuronide, testosterone-glucuronide and 17-hydroxyprogesterone), which belonged to the steroid biosynthesis pathway as significant metabolites upregulated by citrus juice intake. Additionally, these results confirmed the importance of using the non-targeted metabolomics technique to identify new endogenous metabolites, up- or down-regulated as a consequence of food intake.     

Peptidomic analysis of rat urine using capillary electrophoresis coupled to mass spectrometry

We have established and validated a protocol for the peptidomic analysis of rat urine using CE coupled to MS (CE-MS). In the first experiments, the reproducibility of the CE-MS set-up and of the established preparation procedure were assessed. To establish a first rat urinary peptidome map, samples were also analyzed using CE-FT-ICR. The subsequent analysis of independent samples from two different strains (WISTAR and CD) indicated strain-specific differences, which were validated in a blinded assessment. MS/MS revealed the presence of specific fragments from well-known urinary rat peptides, such as collagens, alpha-1-antitrypsin, and serum albumin. The CE-MS-based peptidomics platform may provide novel insights into body fluids of animal models, such as rat or mice. Together with peptide identification, the technology appears to be an excellent, complimentary, and non-invasive tool to analyze toxicological or other (patho)physiological effects of pharmaceutical compounds in animal models.     

Urine collected from diapers can be used for 2-D PAGE in infants and young children

Urinary proteomic profiling has potential to identify candidate biomarkers of renal injury in infants provided an adequate urine sample can be obtained. Although diapers are used to obtain urine for clinical evaluation, their use for proteomic analysis has not been investigated. We therefore performed feasibility studies on the use of diaper-extracted urine for 2-D PAGE. Pediatric waste urine (2–20 mL) was applied to gel-containing, non-gel and cotton-gauze diapers and then mechanically expressed. Urine volume and total protein were measured pre- and post-extraction. Proteins were separated via 2-D PAGE following application of urine (20–40 mL) to each matrix. 2-D PAGE was also performed on clinical specimens collected using each diaper type. Differences in the adsorption and retention of urine volume and protein were noted between matrices. Non-gel and cotton-gauze diapers provided the best protein/volume recovery and the lowest interference with the Bradford assay. 2-D PAGE was also successfully completed using urine samples from both cotton fiber matrices. Conversely, samples from low-gel diapers demonstrated poor protein separation and reproducibility. Diapers containing cotton–fiber matrices appear adequate for 2-D PAGE. Qualitative and quantitative analyses of resolved proteins using replicate, high-resolution gels will be required, however, before diaper-extracted urine can be applied in proteomic profiling.     

Changes in the urinary proteome post-operatively in renal cancer patients – a reflection of tumour or kidney removal?

During the initial phases of a study focussed on discovering new urinary biomarkers for renal cell carcinoma, a number of challenges and limitations were identified, which we subsequently investigated. The purpose of this report is to provide insight into experimental design for such investigations and potential confounding factors that can impact on such studies. Sixty urine samples from 20 patients with clear cell renal cell carcinoma and ten live renal transplant donor patients, pre- and post-nephrectomy, were profiled using SELDI-TOF-MS incorporating stringent quality control and in-house data processing/analysis. There were 65 significantly differentially expressed peaks (five solitary peaks and four peak clusters that increased post nephrectomy and four peak clusters that decreased). Peak 3934 Da m/z and peaks within 11731–11961 Da m/z, which increased post nephrectomy were identified as the 36 amino acid isoform of β-defensin-1 and β₂-microglobulin, respectively. However, changes in these two protein forms were also seen in healthy donors following nephrectomy implying a relationship with kidney removal per se rather than tumour removal. This study indicates the difficulties in identifying SELDI peaks for subsequent validation and illustrates the need for appropriate controls in biomarker studies to determine whether changes are indirect consequences of treatment.