High-pressure Separation Research Articles

Polysulfone-ionic liquid based membranes for CO2/N2 separation with tunable porous surface features

A surprisingly simple, yet effective blending method for ionic liquids (ILs) and polysulfone (PSf) is presented in this paper. Not only is the IL properly immobilised in the polymer matrix, which is crucial in high-pressure gas separation applications, but this method also produces tunable porous surfaced membranes that can be useful in several other applications. The size and distribution of the pores are dependent on the type and amount of IL incorporated into the PSf. A membrane formation mechanism is proposed to explain the presence of such a regular surface pore structure. Several commercially available ILs were tested to examine their compatibility with the polymer, and the CO2/N2 gas separation performance of the resulting membrane was screened. ATR-FTIR spectroscopy, FTIR microscopy, and SEM imaging were also employed to shed light on the observed membrane structures.

Searching for Radical Solutions against Fouling Communities Inhabiting the Arabian Gulf in Saudi Arabia

Searching for Radical Solutions against Fouling Communities Inhabiting the Arabian Gulf in Saudi Arabia Sea squirts produce pelagic larvae that spend few days in the plankton before settling and metamorphosing into their adult sessile forms. Attachment mechanism developed usually relies on highly viscous or solid adhesive secretions, which all contain specialized proteins and glycogen. Adult sea squirts of Ciona intestinalis, Molgula manhattensis, Ascidella aspersa and Phallusia nigra were sampled for 12 months from three estuarine localities of the Arabian Gulf (Ad-Dammam; Northern Khobar and Southern Khobar). Seasonal variation of some analyzed abiotic factors revealed that the population densities of ascidians and the feasibility of larval dispersal were variable not only according to seasons but also according to the study locality where ascidians predominate Southern Khobar˃Northern Khobar ≈ Ad-Dammam and during spring and summer populations are ˃˃ those of autumn < those of winter. Procurement of gametes has been carried out by potassium chloride injection or/and artificial heterologous fertilization. Larvae were cultured and three larval stages were identified. Immunocytochemical approach has been applied to investigate larval metamorphosis under the influence of applied bioactive inducers which had been claimed to induce metamorphosis or involved in signaling systems or serve as neurotransmitters or control morphogenetic and behavioral reactions or interact with members of several signal transduction proteins pathways. The transformation of the larval stage with long tail to the next larval stage with remarkable tail resorption activity is accelerated by NH4Cl 2.5 mM, C8 1 μM, Acetyl choline 1 mM, NOS 1 mM and cGMP 1 μM. To investigate whether NO and HSP 90 play a role in larval metamorphosis, larvae with long tail, partially metamorphosed larvae with short tail and metamorphosing youngs were treated for whole-mount immunohistochemistry towards the green fluorescent protein (GFP). High-pressure chromatographic separation has been carried out to identify amino acids in the adhesive secretions of the larval stage. Western blotting routine technique (Immune blotting) using Bradford assay has been applied to identify proteins of adhesives. SDS-PAGE revealed that the adhesives contained about 11 different proteins. Their apparent molecular masses were approximately 300, 280, 250, 150, 100, 75, 50, 35, 25, 20, and 10 kDa. Total lipids were extracted using capillary gas chromatography and total carbohydrates of adhesives were analyzed by the Phenolsulphuric acid method. This study concluded that lipids of adhesives is secreted first and represented by C14:0; C18:2 V-32; C20:1 V-9; C18:1 V-7; C16:1 V-6 and C18:1 V-5. A post-translational modification of amino acids mainly Phenylalanine, Methionine Threonine, Valine and Serine with glycogen for adhesive and cohesive function occurs. The carbohydrate moiety of adhesives is a polymerization of monosaccharides. All data obtained were subjected to analysis of variance (ANOVA) means significant difference P>0.05 or P<0.05, column comparison test P<0.0001; Df 51-207 and Tukey post hoc test. Bartlett’s test for equal variances P value 0, 4095 has been applied. This study suggested that a fine powdery copper catalyst or boric acid esters and Didecyl polyoxyethyl ammonium borate (DPAB) have to be added as antifouling agents to the paint materials of ships, boats and steels objects in the Arabian Gulf to minimize or prevent fouling stress.

An adsorption study on STA-16(Co)

Adsorption is considered a promising method for carbon capture. CO2 adsorbents take a variety of forms, but one approach is the use of metal-organic frameworks (MOFs). In this study, the potential of STA-16(Co) to selectively adsorb and separate CO2 is considered. Isotherms for CO2 and N2 were measured from 0 to 25 bar at temperatures between 25 and 105 °C to evaluate the potential application in high pressure separation processes. Low pressure CO2 pseudo-isotherms were measured from 0 to 0.5 bar at temperatures between 25 and 105 °C, together with dry and wet cycling experiments, to determine the applicability of STA-16(Co) in a vacuum swing adsorption (VSA) process. The presence of 1% H2O vapour during ten cycle experiments resulted in a decrease in CO2 working capacity obtained under dry cyclic conditions of ∼66% due to the high H2O uptake. In contrast to the majority of MOFs, STA-16(Co) exhibited a good H2O stability and maintained its CO2 adsorption capacity after adsorption/desorption of H2O vapour at 30 and 60% RH at 25 °C. However the treatment at 90% RH resulted in a small decrease in CO2 adsorption capacity, apparently due to the formation of a different crystal structure.

Abstract 1570: Early Detection Research Network (EDRN) validation of circulating ovarian cancer biomarkers

Abstract Developing non-invasive blood-based tests is extremely appealing for early detection of cancers through screening asymptomatic subjects. This is particularly true for epithelial ovarian cancer in which the majority of women are diagnosed at a late stage when frontline therapy is less effective. To date there are no FDA approved biomarkers for ovarian cancer screening. To address this limitation, 165 proteins and 14 autoantibodies, identified as candidate circulating ovarian cancer biomarkers in previous studies at participating EDRN sites, were evaluated for their ability to discriminate ovarian cancer patient samples from those associated with benign ovarian disease. First, an in silico approach was used to prioritize candidate biomarkers likely to be over-expressed in ovarian cancer and predicted to be secreted. In parallel, high performance quantitative tandem mass spectrometry analyses of pooled plasma from serous ovarian cancer cases and serous benign ovarian disease controls were used to confirm candidate detectability in plasma and triage candidates by differential expression. A total of 61 proteins had sufficient evidence from one or more approaches to warrant further evaluation. 32 of the 61 proteins were evaluated using antibody-free selected reaction monitoring mass spectrometry (SRM-MS) assays. 29 of the 61 proteins could only be detected using high-pressure high-resolution separations with intelligent selection and multiplexing (PRISM)-SRM, due to the required analytical sensitivity. Because of its low prevalence, early detection of ovarian cancer requires very high specificity (≥99.6%), achievable when a blood test at 98% specificity is followed by trans-vaginal ultrasound. Therefore, sensitivity was estimated at 98% specificity for all candidates by quantifying candidates in serum from serous ovarian cancer cases (n = 20) and serous benign ovarian disease controls (n = 20). All 14 autoantibody candidates were similarly evaluated by ELISA using an expanded set of 50 serous ovarian cancer cases and 50 serous benign ovarian disease controls. The use of benign ovarian disease controls ensured similar conditions of blood sample acquisition and avoided selection of candidates that are elevated in the presence of benign disease. Candidates with 5% or greater sensitivity were identified as potential members of a panel of ovarian cancer biomarkers. These included WFDC2, SPON1, CBPA4, IBP2, and A2GL proteins, and autoantibodies CTAG2, p53, CTAG1A, and PTPRA. In summary, a multi-pronged approach identified five circulating proteins and four autoantibodies that warrant further evaluation in longitudinal pre-diagnostic plasma or sera from cases detected in screening studies and matched controls. Candidates successful in this future validation may provide the foundation for a new blood-based biomarker panel for the early detection of ovarian cancer. Citation Format: Steven J. Skates, Karen S. Anderson, Tao Liu, Vathany Kulasingam, Dustin Rabideau, Chaochao Wu, Michael Gillette, Andrew K. Godwin, Nicole Urban, Anna Lokshin, Jeffrey Marks, Eleftherios Diamandis, Zhen Zhang, Sudhir Srivastava, Jacob Kagan, Christos Patriotis, Karin Rodland. Early Detection Research Network (EDRN) validation of circulating ovarian cancer biomarkers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1570. doi:10.1158/1538-7445.AM2015-1570

Abstract 1818: Analytical platform evaluation for quantification of ERG oncoprotein in prostate cancer using protein and mRNA detection methods

Abstract Current molecular tests that aid in the diagnosis of prostate cancer (PCa) are based on the detection of PSA and PSA isoforms (blood), overexpression of PCA3 (urine), and overexpression of AMACR (tissue) as biomarkers. The discovery of cancer specific fusion transcripts, which are detected in over 50% of prostate cancers, revolutionized the field. As such, the cancer specific TMPRSS2-ERG gene fusion drives the overexpression of the ERG oncoprotein. Based on this, we hypothesized that ERG protein may serve as a valuable biomarker and for which quantification methods can be applied for the diagnosis of prostate cancer. An antibody-free assay for ERG protein detection was developed based on PRISM (high-pressure high-resolution separations with intelligent selection and multiplexing)-SRM (selected reaction monitoring) mass spectrometry. We utilized TMPRSS2-ERG positive VCaP and TMPRSS2-ERG negative LNCaP cells to simulate three different sample types (cells, tissue, and post-DRE urine sediment) for evaluation. Recombinant ERG protein spiked into LNCaP cell lysates could be detected at levels as low as 20 pg by PRISM-SRM analysis. The sensitivity of the PRISM-SRM assay was approximately 10,000 VCaP cells in a mixed cell population model of VCaP and LNCaP cells. Interestingly, ERG protein could be detected in as few as 600 VCaP cells spiked into female urine, presumably due to more effective loading of ERG protein and the reduced sample complexity. In comparison the detection limit of the in-house enzyme-linked immunosorbent assay was 30 pg of recombinant ERG protein and 10,000 VCaP cells, while Western blot analysis demonstrated the detection of 195 pg of recombinant ERG protein and 10,000 VCaP cells in these two sample types, respectively. On the other hand, qRT-PCR exhibited a higher sensitivity, as TMPRSS2-ERG transcripts were detected in as few as 250 VCaP cells spiked into female urine, in comparison to NanoString methodologies which detected 10,000 VCaP cells in the same sample. In summary the data presented here suggest that qRT-PCR and PRISM-SRM platforms are highly sensitive in detecting TMPRSS2-ERG transcripts and proteins, respectively. Compared to other RNA (without preamplifcation step) and protein detection technologies, the PRISM-SRM assay has several significant advantages: it is not affected by RNA stability, it does not rely on a specific antibody, and it is ideal for isoform-specific detection with high multiplexing capability. Therefore, PRISM-SRM assays can be adapted to detect ERG protein in cells present in clinical specimens (e.g., tissue and urine), and cell-free ERG protein present in the blood sera, providing an opportunity for their use in the clinical setting for detection of ERG in prostate cancer patients and for defining appropriate treatment strategies. Citation Format: Jintang He, Athena Schepmoes, Anshu Rastogi, Shyh-Han Tan, Wusheng Yan, Wei Huang, Sreedatta Banerjee, Tujin Shi, Chaochao Wu, Thomas Fillmore, Yuqian Gao, Jacob Kagan, Sudhir Srivastava, Richard Smith, Wei-Jun Qian, David McLeod, Gyorgy Petrovics, Albert Dobi, Alagarsamy Srinivasan, Shiv Srivastava, Karin Rodland, Tao Liu, David Camp. Analytical platform evaluation for quantification of ERG oncoprotein in prostate cancer using protein and mRNA detection methods. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1818. doi:10.1158/1538-7445.AM2015-1818

Assessment of ZIF materials for CO2 capture from high pressure natural gas streams

Although a considerable amount of the research is focussed in carbon capture specifically towards flue gas separations, another area that is of interest is CO2/CH4 separation for the natural gas industries. It is believed that 40% of the world’s reserves of natural gas are sour, and these gas reserves are typically left unexploited due to their high CO2 content and the costs associated with separation and transport. One recent class of adsorbents, metal organic frameworks (MOFs) has been advocated as potential candidates for CO2 removal from natural gas at high pressure. This can be attributed to their high CO2 capacities, which could be exploited in high pressure separations. In this work we synthesised ZIFs -8, -14 and -71 and measured CO2 and CH4 isotherms over a range of temperatures and pressures. The CO2 capacity for these materials at 303K and 45bar(a) was in the order of ZIF-8 (9.1molkg−1)>ZIF-71 (8.1molkg−1)>ZIF-14 (5.0molkg−1). The CH4 loading at 303K and 100bar(a) was in the order of ZIF-8 (6.8molkg−1)>ZIF-14 (4.8molkg−1)>ZIF-71 (4.4molkg−1). The ideal selectivity of these materials for a 15%mol CO2, 85%mol CH4 feed mixture at 100bar(a) and 303K was found to be 5.6 for ZIF-8, 4.5 for ZIF-14 and 13 for ZIF-71. This isotherm data was then used to design and simulate a pressure swing adsorption process for CO2/CH4 separation.Feed CO2 concentrations between 15%mol and 35%mol were investigated at a condition of 100bar(a) and 303K. It was found that only ZIFs -8 and -71 could achieve the 98%mol CH4 product purity required. ZIF-8 and ZIF-71 were able to achieve CH4 recoveries of 46%mol and 48%mol respectively. Furthermore, it was also found that ZIFs -8 and -71 behaved very similarly when compared on a volume of adsorbent basis. The CH4 uptake of ZIF-14 was found to be abnormally high, which resulted in a very low CO2/CH4 selectivity. The loading of CH4 was higher than CO2 for both the 15%mol and 25%mol CO2 feed cases, with only the 35%mol CO2 feed resulting in a higher CO2 capacity, 4.6molkg−1 of CO2 in comparison to 4.1molkg−1 of CH4.Although their CO2 capacities at high pressures are high, there is little discrimination between the adsorption of small molecules. Consequently, their CH4 loadings also increase substantially at those increased pressures. This results in a poor separation with the CO2 product becoming diluted with the co-adsorbed CH4 gas.

Facilitated transport membranes containing amino-functionalized multi-walled carbon nanotubes for high-pressure CO2 separations

In the present work, high-performance mixed matrix membranes containing amines have been developed for effective CO2 removal at high pressures (15–28bar) and high temperatures (103–121°C). The membrane was synthesized by compatibly embedding amino-functionalized multi-walled carbon nanotubes (AF-MWNTs) as mechanical reinforcing fillers in the crosslinked polyvinylalcohol–polysiloxane/amine blend. The surface functionalization of MWNTs allows strong coupling with the hydrophilic membrane matrix to form a nano-reinforced facilitated transport membrane, which achieved exceptional CO2 selectivity and permeability via the facilitated transport mechanism as well as attractive membrane stability via the incorporation of MWNTs. The synthesized membranes exhibited an average CO2 permeability of 957 Barrers coupled with high selectivities vs. H2 (56), CH4 (264), and N2 (384) at 107°C and 15bar. The effects of AF-MWNT loading, high molecular weight species content, selective layer thickness, feed pressure, relative humidity, and temperature on membrane performance were thoroughly studied for a fundamental understanding of membrane properties. Furthermore, a mathematical model has been used to describe and explain the thickness-dependent CO2 transport behavior in the membrane. The combination of high CO2 permeability and good selectivities vs. CH4, H2, and N2, along with enhanced mechanical stability, makes the membrane a promising candidate for the gas separation applications at high pressures.

Model-based analysis of polymeric membranes performance in high pressure CO2 removal from natural gas

Penetrant-induced plasticization is known to be one of the main challenges of high-pressure membrane separation of CO2 from natural gas. Therefore, a procedure that integrates experimental and mathematical models was developed to analyze the performance of polymeric membranes for removal of CO2 at high feed pressure. A semi-empirical model for estimating plasticization pressure and permeability parameters at plasticization from permeation test data was proposed and tested on more than 90 polymeric membranes. Three model parameters (α1, α2 , and α3) were obtained and used to evaluate membrane performance in terms of plasticization pressure as well as permeability and productivity loss at plasticization pressure. Results from the analysis revealed that this set of parameters can be simply employed to evaluate membrane performance at high pressure.

A luminescent Zr-based metal–organic framework for sensing/capture of nitrobenzene and high-pressure separation of CH4/C2H6

A novel LMOF based on a new tetracarboxylate ligand is reported with not only high performance of sensing and capture of nitrobenzene but also high-pressure separation of CH4/C2H6.

Abstract 2483: An antibody-independent, complementary SRM strategy for ultrasensitive and multiplexed quantification of cancer biomarker candidates

Abstract Stable-isotope dilution coupled to targeted mass spectrometry (MS), applying selected reaction monitoring (SRM), provides good selectivity, reproducibility, sensitivity, and multiplexing capability rendering it highly suitable for robust, high-throughput and cost-effective verification of cancer biomarker candidates. The ability of SRM-MS to detect and quantify low abundance proteins present in blood plasma/serum at low ng/mL or even lower levels, however, relies on the front-end enrichment through specific affinity reagents (e.g., antibodies). To address this limitation, we have recently developed two antibody-independent, targeted quantification capabilities that enable protein quantification at low or sub ng/mL levels in plasma/serum. The first new capability, PRISM (high-pressure high-resolution separations with intelligent selection and multiplexing)-SRM, uses high resolution basic pH reversed-phase capillary liquid chromatographic (LC) separation with on-line SRM monitoring for the enrichment of target peptides and intelligent selection of target fractions for subsequent LC-SRM analysis that uses very short LC gradient to achieve better sensitivity and improved sample throughput. Application of PRISM-SRM enables highly sensitivity detection of several prostate cancer relevant proteins, e.g., prostate-specific antigen (PSA) and anterior gradient 2 (AGR2) proteins at ∼100 pg/mL level in serum, and distinct TMPRSS2-ERG fusion protein isoforms in cell line and tumor tissue samples. The front-end sample prefractionation often requires a relatively large amount of starting material (e.g., 25 ug in PRISM-SRM analysis) and increased instrument analysis time, and undesired sample losses are often encountered during multistep sample preparation. These can be effectively overcome by the second new capability, long-gradient separations coupled with SRM (LG-SRM). Our results show that LG-SRM enables reliable quantification of plasma proteins at low ng/mL levels in nondepleted human plasma/serum. Comparing to fractionation-based SRM methods, LG-SRM offers better sample throughput, requires minute amounts of starting materials (e.g., ∼4 μg), and provides at least 3-fold greater multiplexing capacity than conventional LC-SRM due to ∼3-fold increase in average peak widths. The complementary SRM strategy encompasses both PRISM-SRM and LG-SRM and is therefore highly attractive for the sensitive and multiplexed quantification of cancer biomarker candidates - PRISM-SRM offers ∼10X higher sensitivity, but LG-SRM requires much less sample and can be readily implemented. It is anticipated that these affinity reagent-free, highly sensitive proteomics measurements made possible by this complementary SRM strategy will bring new biological insights and perspectives to prostate cancer research as well as other cancers. Citation Format: Tujin Shi, Jintang He, Chaochao Wu, Thomas L. Fillmore, Athena A. Schepmoes, Mark Rubin, Javed Siddiqui, John Wei, Arul Chinnaiyan, Alvin Liu, Richard D. Smith, Jacob Kagan, Sudhir Srivastava, Karin D. Rodland, Wei-Jun Qian, Tao Liu, David G. Camp. An antibody-independent, complementary SRM strategy for ultrasensitive and multiplexed quantification of cancer biomarker candidates. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2483. doi:10.1158/1538-7445.AM2014-2483

Assessing the N2O/CO2 high pressure separation using ionic liquids with the soft-SAFT EoS

The capabilities of the soft-SAFT EoS to accurately describe the thermophysical properties of ionic liquids (ILs) and the phase equilibria of their mixtures with greenhouse gases is extended in this work to address the CO2 and the N2O solubilities in [C4mim]+ ILs from different anion families. In addition to the commonly studied [BF4]− and [NTf2]− anions, the solubility of these gases in ILs with the anions [N(CN)2]−, [SCN]− and [Ac]− is also studied and compared among them, searching for the best system for separation purposes.A coarse-grained molecular model is proposed within the soft-SAFT framework for each newly studied IL based on structural information, guidance obtained from quantum calculations and previous work. The most adequate set of molecular parameters are selected from the ILs density description and from the ability to reproduce the N2O/CO2 solubilities in these ILs at the lowest and highest temperatures for which experimental data are available. A discussion about the association molecular parameters values and their relation with the anion nature is also presented.With these molecular models, the description of the high pressure phase equilibria of the binary systems composed of the two gases and the ILs referred above are described with soft-SAFT for the remaining isotherms. For most systems, the equilibria behavior of the mixtures is predicted without using any binary parameter. When good agreement with the experimental data is not achieved, a single temperature independent binary parameter is enough to allow a good description. Finally, Henry's law constants are calculated from soft-SAFT to evaluate the selectivity of those ILs for the CO2/N2O separation.

“Brick-and-mortar” synthesis of free-standing mesoporous carbon nanocomposite membranes as supports of room temperature ionic liquids for CO2−N2 separation

Free-standing mesoporous carbon−graphitic carbon nanocomposite membranes with controllable pore size (7.3−11.3nm) were synthesized by the “brick-and-mortar” method, carbon black (CB) as “bricks” and soft-templated phenolic resin-based mesoporous carbon (MC) as the “mortar”. Immobilization of imidazolium-based room temperature ionic liquids ([Cnmim][Tf2N], n=2, 4, and 6) in the MC−CB membranes produced a series of supported ionic liquid membranes (SILMs) that are permselective for separation of CO2−N2 gas pair. Strong capillary forces resulting from the well-developed mesoporosity of the MC−CB membranes greatly enhanced the stability of the supported ionic liquids. This enabled the SILMs to operate under transmembrane pressures as high as 1000kPa without degrading their separation performance. This makes it possible to apply SILMs to high-pressure CO2 capture and separation processes, where high transmembrane pressure would greatly increase the permeate flux through the membranes.

Polyaniline in situ modified halloysite nanotubes incorporated asymmetric mixed matrix membrane for gas separation

The embodiment of polyaniline in situ modified halloysite nanotubes (PANi–HNTs) on the gas permeation properties of CO2, CH4, O2, and N2 gases in polysulfone (PSf) membrane has been investigated. Halloysite nanotubes (HNTs) were modified by in situ polymerization of aniline. Asymmetric mixed matrix membranes (MMMs) were synthesized by varying the PANi–HNTs concentrations of 0.5–2.5wt.% of polymer in the PSf solutions. The MMMs were characterized by SEM, ATR-IR, DSC and XRD. Membrane characterization reveals the structural change of the filler and interaction of PANi with PSf polymer matrix. The permeance of pure gases and the ideal selectivities were determined using an indigenously built high-pressure gas separation manifold. Increasing the PANi–HNTs incorporation in polymer enhanced the permeance of CO2 from 17.4 to 68.4GPU, CH4 from 0.8 to 4.8GPU, O2 from 3.9 to 18.8GPU and N2 from 0.7 to 3.1GPU, respectively. The use of PANi–HNTs loaded PSf membranes provides a means for separation of CO2/CH4, CO2/N2 and O2/N2.

Mixed matrix membranes of Pebax-1657 loaded with 4A zeolite for gaseous separations

Mixed matrix membranes (MMMs) made from selective inorganic fillers and polymers have received extensive attention in the field of gas separation. In this work, poly(ether-block-amide), (Pebax)/zeolite 4A MMMs were prepared using ethanol/water as solvent mixture. The concentration of zeolite 4A in membrane was varied from 5 to 30wt.% of the polymer. The membranes were characterized by SEM, FTIR and XRD to study the morphologies, the effect of zeolite 4A incorporation on intermolecular interactions and degree of crystallinity, respectively. The pure gas permeabilities were recorded at the ambient temperature, using an indigenously built high-pressure gas separation manifold. The permeabilities of Pebax-1657/zeolite 4A membranes were enhanced from 71.4 to 155.7 Barrers for CO2, 2.2–19.6 Barrers for CH4, 5.8–17.9 Barrers O2 and 1.4–12.0 Barrers for N2. The ideal selectivity of 10wt.% zeolite 4A MMM enhanced from 54.1 to 94.2 for the CO2/N2 gas pair with increase in feed pressure from 5 to 25kg/cm2, whereas the corresponding values for CO2/CH4 and O2/N2 were found to rise from 26.4 to 41.3 and 4.3 to 4.9, respectively. The Pebax/zeolite 4A membranes thus provide a potentially promising means for separation of CO2/N2, CO2/CH4, and enrichment of O2 and N2 from air.

Antibody-independent targeted quantification of TMPRSS2-ERG fusion protein products in prostate cancer

Fusions between the transmembrane protease serine 2 (TMPRSS2) and ETS related gene (ERG) represent one of the most specific biomarkers that define a distinct molecular subtype of prostate cancer. Studies of TMPRSS2-ERG gene fusions have seldom been performed at the protein level, primarily due to the lack of high-quality antibodies suitable for quantitative studies. Herein, we applied a recently developed PRISM (high-pressure high-resolution separations with intelligent selection and multiplexing)-SRM (selected reaction monitoring) strategy for quantifying ERG protein in prostate cancer cell lines and tumors. The highly sensitive PRISM-SRM assays provided confident detection of 6 unique ERG peptides in both TMPRSS2-ERG positive cell lines and tissues, but not in cell lines or tissues lacking the TMPRSS2-ERG rearrangement, clearly indicating that ERG protein expression is significantly increased in the presence of the TMPRSS2-ERG gene fusion. Significantly, our results provide evidence that two distinct ERG protein isoforms are simultaneously expressed in TMPRSS2-ERG positive samples as evidenced by the concomitant detection of two mutually exclusive peptides in two patient tumors and in the VCaP prostate cancer cell line. Three peptides, shared across almost all fusion protein products, were determined to be the most abundant peptides, providing “signature” peptides for detection of ERG over-expression resulting from TMPRSS2-ERG gene fusion. The PRISM-SRM assays provide valuable tools for studying TMPRSS2-ERG gene fusion protein products in prostate cancer.

Separation of Binary Mixtures of Propylene and Propane by Facilitated Transport through Silver Incorporated Poly(Ether-Block-Amide) Membranes

The separation of propylene and propane is a challenging task in petroleum refineries due to the similar molecular sizes and physical properties of two gases. Composite Poly(ether-block-amide) (Pebax-1657) membranes incorporated with silver tetra fluoroborate (AgBF4 ) in concentrations of 0-50% of the polymer weight were prepared by solution casting and solvent evaporation technique. The membranes were characterized by Scanning Electron Microscopy (SEM), Fourier Transform InfraRed (FTIR) and wide-angle X-ray Diffraction (XRD) to study surface and cross-sectional morphologies, effect of incorporation on intermolecular interactions and degree of crystallinity, respectively. Experimental data was measured with an indigenously built high-pressure gas separation manifold having an effective membrane area of 42 cm2 . Permeability and selectivity of membranes were determined for three different binary mixtures of propylene-propane at pressures varying in the range 2-6 bar. Selectivity of C3 H6 /C3 H8 enhanced from 2.92 to 17.22 and 2.11 to 20.38 for 50/50 and 66/34 C3 H6 +C3 H8 feed mixtures, respectively, with increasing loading of AgBF4 . Pebax membranes incorporated with AgBF4 exhibit strong potential for the separation of C3 H6 /C3 H8 mixtures in petroleum refineries.

航空機の空調システム設計（第1報：システム作動における高圧除湿系統の機器能力の影響）

The purpose of this study is to clarify the effect of a component for high-pressure water separation, which is included in the air conditioning system of the general commercial aircrafts, on the air-cycle operation (reverse Brayton cycle); the high-pressure water separation consists of water separator and two heat exchangers called reheater and condenser, respectively. This paper briefly describes the typical system configuration of the air-cycle refrigeration progressed with evolutions in turbofan engine. Since nowadays, 4-Wheel air-cycle has been a trend on the aircraft air conditioning system, this paper theoretically shows its advantage on the basis of the thermodynamic cycle study. In the following chapters, an analysis was conducted on the interaction between a reheater and a condenser when each heat transfer performance changes from the baseline operating point. Also, the comparative study was made on the system performances by the 3-wheel and 4-wheel air-cycle. In addition, this paper describes how the heat transfer performance is designed for the reheater and the condenser under the system requirements for the entire air conditioning system.

A Highly Sensitive Targeted Mass Spectrometric Assay for Quantification of AGR2 Protein in Human Urine and Serum

Anterior gradient 2 (AGR2) is a secreted, cancer-associated protein in many types of epithelial cancer cells. We developed a highly sensitive targeted mass spectrometric assay for quantification of AGR2 in urine and serum. Digested peptides from clinical samples were processed by PRISM (high pressure and high resolution separations coupled with intelligent selection and multiplexing), which incorporates high pH reversed-phase liquid chromatography (LC) separations to fractionate and select target fractions for follow-on LC-selected reaction monitoring (LC-SRM) analyses. The PRISM-SRM assay for AGR2 showed a reproducibility of <10% CV and limit of quantification (LOQ) values of ∼130 pg/mL in serum and ∼10 pg per 100 μg of total protein mass in urine, respectively. A good correlation (R(2) = 0.91) was observed for the measurable AGR2 concentrations in urine between SRM and enzyme-linked immunosorbent assay (ELISA). On the basis of an initial cohort of 37 subjects, urinary AGR2/PSA concentration ratios showed a significant difference (P = 0.026) between noncancer and cancer. Large clinical cohort studies are needed for the validation of AGR2 as a useful diagnostic biomarker for prostate cancer. Our work validated the approach of identifying candidate secreted protein biomarkers through genomics and measurement by targeted proteomics, especially for proteins where no immunoassays are available.

Assessing Anhydrous Tertiary Alkanolamines for High-Pressure Gas Purifications

Anhydrous tertiary alkanolamines chemically react with CO2 and H2S, with greater selectivity for the latter. This is in direct contrast to aqueous amine-based solvent systems, which exhibit higher selectivity for CO2 over H2S. Anhydrous tertiary alkanolamines exhibit pressure-induced chemical fixation of CO2 to form zwitterionic ammonium alkylcarbonate ionic liquids, while the same tertiary alkanolamines react with H2S at atmospheric pressures to form hydrosulfide ionic liquids. This difference in capture pressure implies that certain anhydrous alkanolamines could be chemically selective for H2S over CO2. We present here the first published vapor–liquid–liquid equilibrium (VLLE) data of anhydrous ethyldiethanolamine (EDEA) with CH4, C3H8, H2S, and CO2 at 10–50 °C measured by the TPx and TPxy methods. The data are modeled in Aspen Plus using an NRTL-with-solvation model. Data trends and the underlying phenomena are discussed for each gas. We also present process simulations that compare anhydrous EDEA’s performance for CO2 and H2S high-pressure separations to other solvents such as Fluor Solvent (propylene carbonate), Selexol, and aqueous methyldiethanolamine (MDEA) for a representative gas-purification absorber. This work indicates that a niche for anhydrous EDEA in high-pressure gas purifications may be its stronger absorption for CO2 and H2S (relative to physical solvents) and its selectivity for H2S over CO2 (relative to chemical solvents).

High pressure separation of greenhouse gases from air with 1-ethyl-3-methylimidazolium methyl-phosphonate

Increasing pollutants emissions, along with the limitations present on the existing control methods and stricter legislation to come, demand the development of new methods to reduce them. Ionic liquids (ILs) have been attracting an outstanding attention during the last decade and rose as a promising class of viable solvents to capture pollutants and for gas separation processes. As part of a continuing effort to develop an ionic liquid based process for high pressure capture of greenhouse gases, the phase equilibria of carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and nitrogen (N2) in 1-ethyl-3-methylimidazolium methyl-phosphonate ([C2mim][CH3OHPO2]) were studied in this work.Experimental measurements for the CO2, N2O, CH4 and N2 solubilities in [C2mim][CH3OHPO2] were carried out for gases mole fractions ranging from (0.018 to 0.504), in the temperature range (293.23 to 363.34)K and for pressures from (1.16 to 87.61)MPa.The particular behavior of the selected highly polar ionic liquid is here shown for the first time through the reported experimental data. The low N2, CH4 and CO2 solubilities, with the later system presenting positive deviations to ideality, show the ionic liquid unfavorable interactions with the studied gases and the necessity to find a proper compromise between the solvent polarity and its molar volume in order to achieve high CO2/N2 or CO2/CH4 separation selectivities.The good soft-SAFT EoS performance in describing the thermophysical properties of ionic liquids and the phase equilibria of their mixtures with gases was extended in this work for the description of the experimental data reported. New and reliable molecular schemes for N2O and [C2mim][CH3OHPO2], not yet studied within the soft-SAFT framework, were proposed. Using no more than one binary interaction parameter, the soft-SAFT EoS is able to take into account the particular pressure and temperature behavior of the different gases solubilities in the selected ionic liquid. This empowers the equation to be reliably used for other similar systems, as tool to optimize the given process, searching for the best conditions for capture.