Optimal Water Backwashing Condition in Combined Water Treatment of Alumina Microfiltration and PP Beads

Membrane fouling is a dominant limit of the membrane separation process. In this research, the optimal water backwashing to solve the membrane fouling problem was investigated in the combined water treatment process of alumina MF and pure polypropylene (PP) beads. Additionally, the influence of membrane shape (tubular or seven channel) was examined, depending on the water backwashing period. The optimal backwashing time (BT) could be 20 s in the combined water treatment process, because of the highest total treated volume (VT) in our BT 6–30 s conditions. The optimal backwashing period (BP) could be 6 min, because of the minimum membrane fouling and the maximum VT in the combined process of tubular alumina MF and PP beads. The resistance of reversible membrane fouling (Rrf) showed a major resistance of total membrane fouling, and that of irreversible membrane fouling (Rif) was a minor one, in the combined process using tubular or seven channel MF. The Rif showed a decreasing trend obviously, as decreasing BT from NBW to 2 min for seven channel MF. It means that the more frequent water backwashing could be more effective to control the membrane fouling, especially irreversible fouling, for seven channel membranes than tubular membranes.

Synuclein Regulates Synaptic Vesicle Clustering and Docking at a Vertebrate Synapse

Neurotransmission relies critically on the exocytotic release of neurotransmitters from small synaptic vesicles (SVs) at the active zone. Therefore, it is essential for neurons to maintain an adequate pool of SVs clustered at synapses in order to sustain efficient neurotransmission. It is well established that the phosphoprotein synapsin 1 regulates SV clustering at synapses. Here, we demonstrate that synuclein, another SV-associated protein and synapsin binding partner, also modulates SV clustering at a vertebrate synapse. When acutely introduced to unstimulated lamprey reticulospinal synapses, a pan-synuclein antibody raised against the N-terminal domain of α-synuclein induced a significant loss of SVs at the synapse. Both docked SVs and the distal reserve pool of SVs were depleted, resulting in a loss of total membrane at synapses. In contrast, antibodies against two other abundant SV-associated proteins, synaptic vesicle glycoprotein 2 (SV2) and vesicle-associated membrane protein (VAMP/synaptobrevin), had no effect on the size or distribution of SV clusters. Synuclein perturbation caused a dose-dependent reduction in the number of SVs at synapses. Interestingly, the large SV clusters appeared to disperse into smaller SV clusters, as well as individual SVs. Thus, synuclein regulates clustering of SVs at resting synapses, as well as docking of SVs at the active zone. These findings reveal new roles for synuclein at the synapse and provide critical insights into diseases associated with α-synuclein dysfunction, such as Parkinson’s disease.

Activation of regulatory T cells triggers specific changes in glycosylation associated with Siglec-1-dependent inflammatory responses

Background: Siglec-1 is a macrophage lectin-like receptor that mediates sialic acid-dependent cellular interactions. Its upregulation on macrophages in autoimmune disease was shown previously to promote inflammation through suppressing the expansion of regulatory T cells (Tregs). Here we investigate the molecular basis for Siglec-1 binding to Tregs using in vitro-induced cells as a model system. Methods: Glycosylation changes that affect Siglec‑1 binding were studied by comparing activated and resting Tregs using RNA-Seq, glycomics, proteomics and binding of selected antibodies and lectins. A proximity labelling and proteomics strategy was used to identify Siglec-1 counter-receptors expressed on activated Tregs. Results: Siglec-1 binding was strongly upregulated on activated Tregs, but lost under resting conditions. Glycomics revealed changes in N-glycans and glycolipids following Treg activation and we observed changes in expression of multiple ‘glycogenes’ that could lead to the observed increase in Siglec-1 binding. Proximity labelling of intact, living cells identified 49 glycoproteins expressed by activated Tregs that may function as Siglec-1 counter-receptors. These represent ~5% of the total membrane protein pool and were mainly related to T cell activation and proliferation. We demonstrate that several of these counter-receptors were upregulated following activation of Tregs and provide initial evidence that their altered glycosylation may also be important for Siglec-1 binding. Conclusions: We provide the first comprehensive analysis of glycan changes that occur in activated Tregs, leading to recognition by the macrophage lectin, Siglec-1 and suppression of Treg expansion. We furthermore provide insights into glycoprotein counter-receptors for Siglec-1 expressed by activated Tregs that are likely to be important for suppressing Treg expansion.

A novel roadmap connecting the 1H-MRS total choline resonance to all hallmarks of cancer following targeted therapy

This review describes a cellular adaptive stress signalling roadmap connecting the 1H magnetic resonance spectroscopy (MRS) total choline peak at 3.2 ppm (tCho) to cancer response after targeted therapy (TT). Recent research on cell signalling, tCho metabolism, and TT of cancer has been retrospectively re-examined. Signalling research describes how the unfolded protein response (UPR), a major stress signalling network, transduces, regulates, and rewires the total membrane turnover in different cancer hallmarks after a TT stress. In particular, the UPR signalling maintains or increases total membrane turnover in all pro-survival hallmarks, whilst dramatically decreases turnover during apoptosis, a pro-death hallmark. Recent research depicts the TT-induced stress as a crucial event responsible for interrupting UPR pro-survival pathways, leading to an UPR-mediated cell death. The 1H-MRS tCho resonance represents the total mobile precursors and products during the enzymatic modification of phosphatidylcholine membrane abundance. The tCho profile represents a biomarker that noninvasively monitors TT-induced enzymatic changes in total membrane turnover in a wide variety of existing and new anticancer treatments targeting specific layers of the UPR signalling network. Our overview strongly suggests further evaluating and validating the 1H-MRS tCho peak as a powerful noninvasive imaging biomarker of cancer response in TT clinical trials.

A Bidirectional Knudsen Pump with a 3D-Printed Thermal Management Platform

This paper reports on a bidirectional Knudsen pump (KP) with a 3D-printed thermal management platform; the pump is intended principally for microscale gas chromatography applications. Knudsen pumps utilize thermal transpiration, where non-viscous flow is created against a temperature gradient; no moving parts are necessary. Here, a specialized design leverages 3D direct metal laser sintering and provides thermal management that minimizes loss from a joule heater located on the outlet side of KP, while maintaining convective cooling on the inlet side. The 3D-KP design is integrative and compact, and is specifically intended to simplify assembly. The 3D-KP pumping area is ≈1.1 cm2; with the integrated heat sink, the structure has a footprint of 64.2 × 64.2 mm2. Using mixed cellulose ester (MCE) membranes with a 25 nm average pore diameter and 525 μm total membrane thickness as the pumping media, the 3D-KP achieves a maximum flow rate of 0.39 sccm and blocking pressure of 818.2 Pa at 2 W input power. The operating temperature is 72.2 °C at ambient room temperature. In addition to MCE membranes, anodic aluminum oxide (AAO) membranes are evaluated as the pumping media; these AAO membranes can accommodate higher operating temperatures than MCE membranes. The 3D-KP with AAO membranes with 0.2 μm average pore diameter and 531 μm total membrane thickness achieves a maximum flow rate of 0.75 sccm and blocking pressure of 496.1 Pa at 9.8 W at an operating temperature of 191.2 °C.

Performance analysis of two-stage pressure retarded osmosis

The performance of a two-stage pressure retarded osmosis (PRO) for power generation with a total membrane length of 1 meter was investigated and analyzed in this work. Two feed configurations of freshwater and seawater were studied: one with the freshwater entering at the first stage only and the other with freshwater entering at both stages. The effect of membrane length and flow ratio between freshwater and seawater on the PRO performance were also examined. The results revealed that the performances of both feed configurations were quite similar. The membrane with a shorter length offered a higher average power density than that of a longer length. It was also revealed that the flow ratio had a strong influence on the average power density produced. The maximum average power density of 10.15 W/m2 was obtained at the applied hydraulic pressure of 12 bar, the flow ratio of 5, and the membrane length of both stages of 0.5 meter. The best water utilization was achieved at 65%.

Scale-Up of Membrane-Based Zinc Recovery from Spent Pickling Acids of Hot-Dip Galvanizing

Zinc recovery from spent pickling acids (SPAs) can play an important role in achieving a circular economy in the galvanizing industry. This work evaluates the scale-up of membrane-based solvent extraction technology aimed at the selective separation of zinc from industrial SPAs as a purification step prior to zinc electrowinning (EW). The experiments were carried out at a pilot scale treating SPAs batches of 57 to 91 L in a non-dispersive solvent extraction (NDSX) configuration that simultaneously performed the extraction and backextraction steps. The pilot plant was equipped with four hollow fiber contactors and 80 m2 of total membrane area, which was approximately 30 times higher than previous bench-scale studies. Tributylphosphate diluted in Shellsol D70 and tap water were used as organic and stripping agents, respectively. Starting with SPAs with high Zn (71.7 ± 4.3 g·L−1) and Fe (82.9 ± 5.0 g·L−1) content, the NDSX process achieved a stripping phase with 55.7 g Zn·L−1 and only 3.2 g Fe·L−1. Other minor metals were not transferred, providing the purified zinc stripping with better quality for the next EW step. A series of five consecutive pilot-scale experiments showed the reproducibility of results, which is an indicator of the stability of the organic extractant and its adequate regeneration in the NDSX operation. Zinc mass transfer fluxes were successfully correlated to zinc concentration in the feed SPA phase, together with data extracted from previous laboratory-scale experiments, allowing us to obtain the design parameter that will enable the leap to the industrial scale. Therefore, the results herein presented demonstrate the NDSX technology in an industrially relevant environment equivalent to TRL 6, which is an essential progress to increase zinc metal resources in the galvanizing sector.

Regulatory T cell activation triggers specific changes in glycosylation associated with Siglec-1-dependent inflammatory responses

Siglec-1 is a macrophage lectin-like receptor that mediates sialic acid-dependent cellular interactions. It was shown previously to promote inflammation in autoimmune disease through suppressing the expansion of regulatory T cells (Tregs). We have investigated the molecular basis for Siglec-1 binding to these cells using in vitro-induced Tregs. Siglec-1 binding was strongly upregulated on activated cells, but lost under resting conditions. Glycosylation changes that affect Siglec-1 binding were studied by comparing activated and resting Tregs using RNA-Seq, glycomics, proteomics and binding of selected antibodies and lectins. A proximity labelling and proteomics strategy identified 49 glycoproteins expressed by activated Tregs that may function as Siglec-1 counter-receptors. These represent ∼5% of the total membrane protein pool and were mainly related to T cell activation and proliferation. We demonstrate that several of these counter-receptors are upregulated following activation of Tregs and provide initial evidence that their altered glycosylation may also be important for Siglec-1 binding.

M10. SERUM AND CLINICAL MARKERS ASSOCIATED WITH MEMBRANE PUFA CONTENT IN A POPULATION OF STABILISED AND TREATED SCHIZOPHRENIA OUTPATIENTS

Background Various candidate biomarkers have been proposed in schizophrenia to better characterise the several forms of the disorder. Among these candidates, peripheral (e.g. immunological, inflammatory, microbial) and brain (structural and functional) factors have been suggested and could help subtyping schizophrenia. One other potential biomarker, the membrane polyunsaturated fatty acid (PUFA) content, has been described both in peripheral cells and brain membranes of patients. Increased symptom severity along with more severe cognitive impairment were shown to be associated with decrease in the red blood cell (RBC) membrane sphingomyelin and PUFA content. However, little is known regarding the association between this membrane biomarker and serum related ones. The results presented here are preliminary and come from a study examining clinical and cognitive symptoms, RBC total membrane fatty-acid (FA) content, and serum biomarkers in a population of schizophrenia patients. We hypothesised that the sub-group of patients with decreased membrane PUFA content will also exhibit a higher incidence of abnormalities in some other serum biomarkers in comparison with patients with normal membrane PUFA content. Methods A population of 33 chronic, medicated, and clinically stable patients with schizophrenia gave their informed consent for a study examining in particular their medical, psychiatric, and treatment history. The other measures assessed psychopathology (PANSS, CGI, Calgary scale), functioning and quality of life (GAF, SF36), and cognition (MOCA, MCST). Various biological biomarkers - in particular those related to inflammation, immunity, energy and hormone metabolism - were also examined. The total RBC membrane FA content was also measured using GC-FID (Gas Chromatography–Flame-Ionization Detection). Results Based on the standard values of the docosohexaenoic acid (DHA) (expressed as percentage of total fatty acids) in the RBC lipid membrane, a subgroup of 18 patients exhibited an abnormal decrease in DHA content (DHA-), while the remaining 15 individuals had DHA value within the normal range (DHAn). DHA- and DHAn groups were compared using univariate analysis in terms of other clinical and biological associated characteristics. We could also demonstrate a decrease in total membrane PUFAs in the DHA- group (p=0.004). Of interest, serum IL-6 was significantly (p=0.02) increased in the DHA- population. There was also a trend in favour of an increase in serum TNF-alpha in DHA- (mean value 30.5 vs 21 in DHA- and DHAn, respectively). In addition, the DHA- group have had significantly (p=0.03) more hospitalisations since the beginning of the disorder. The duration of untreated psychosis was 4 years vs 1 year in the DHA- vs DHAn groups, respectively. The same applied for the mean duration of hospitalisations (45 vs 34 days in DHA- vs DHAn). These values could not be explained by a longer duration in disease treatment in the 2 subpopulations. Discussion The presented data are in accordance with repeated findings showing decreased RBC membrane DHA and total PUFA content in a subgroup of individuals meeting criteria for schizophrenia. The splitting of the studied population into 2 groups numerically comparable as a function of their RBC membrane DHA content was thus justified. Interestingly, patients with lower membrane DHA content also exhibited abnormalities in other known biomarkers described in schizophrenia such as increased inflammation and disease severity. The presented data also show for the first time a biomarker associated with the duration of untreated psychosis. Altogether, these results, despite preliminary, are paving the way towards the identification of schizophrenia subtypes.

Modification of the Bacterial Cell Wall—Is the Bioavailability Important in Creosote Biodegradation?

Creosote oil, widely used as a wood preservative, is a complex mixture of different polycyclic aromatic compounds. The soil contamination result in the presence of a specific microcosm. The presented study focuses on the most active strains involved in bioremediation of long-term creosote-contaminated soil. In three soil samples from different boreholes, two Sphingomonas maltophilia (S. maltophilia) and one Paenibacillus ulginis (P. ulginis) strain were isolated. The conducted experiments showed the differences and similarities between the bacteria strains capable of degrading creosote from the same contaminated area. Both S. maltophilia strains exhibit higher biodegradation efficiency (over 50% after 28 days) and greater increase in glutathione S-transferase activity than P. ulginis ODW 5.9. However, S. maltophilia ODW 3.7 and P. ulginis ODW 5.9 were different from the third of the tested strains. The growth of the former two on creosote resulted in an increase in cell adhesion to Congo red and in the total membrane permeability. Nevertheless, all three strains have shown a decrease in the permeability of the inner cell membrane. That suggests the complex relationship between the cell surface modifications and bioavailability of the creosote to microorganisms. The conducted research allowed us to broaden the current knowledge about the creosote bioremediation and the properties of microorganisms involved in the process.