High Cell Concentrations Research Articles

The effect of prednisolone on endometrial uterine NK cell concentrations and pregnancy outcome in women with reproductive failure. A retrospective cohort study

This retrospective study of prospectively collected data examines the effect of prednisolone therapy on raised uterine Natural Killer cell (uNK) concentrations and pregnancy outcomes in women with recurrent miscarriage (RM) and recurrent implantation failure (RIF) after IVF/ICSI treatment. 136 women diagnosed with RRF who had a timed midluteal endometrial biopsy taken for uNK cell analysis were included. Women with high uNK cell concentrations (n = 45) were treated with prednisolone (10 mg/day) for one month, after which a second biopsy was taken for repeat uNK cell analysis. Women for whom prednisolone caused a decrease in uNK cell concentrations continued on prednisolone until 12 weeks of pregnancy. Pregnancy outcomes (live birth, miscarriage and implantation rates) and pregnancy complications were compared for women who received prednisolone and those who did not. Results showed that the prevalence of high uNK cells was 33.1%. Prednisolone significantly decreased the uNK cell concentration (P < 0.001), however reduction to normal limits was achieved in only 48.3% of patients. There was no difference in any of the pregnancy outcomes or complications between women who had received prednisolone and those who had not. In conclusion, this study showed a relatively high prevalence of raised uNK cells in women with recurrent reproductive failure and confirmed the effect of prednisolone on reducing uNK cell concentrations. We found however no evidence for a significant beneficial effect for prednisolone therapy on pregnancy outcomes. Until the results of an adequately powered RCT become available however, these findings should be considered preliminary.

Adipose Stromal Vascular Fraction Gel Grafting: A New Method for Tissue Volumization and Rejuvenation.

The clinical outcomes of fat grafting vary and are technique-dependent. Stromal vascular fraction (SVF) gel is a novel, mechanically processed fat product with high concentrations of adipose tissue-derived stem cells and other SVF cells. This study evaluated the volumization and rejuvenation effects of SVF-gel. This study evaluated the volumization and rejuvenation effects of SVF-gel. This retrospective, single-center study included 126 patients who underwent SVF-gel grafting and 78 who underwent conventional lipoinjection for various indications from March 2015 to February 2017. Patient satisfaction and secondary surgery rates were evaluated. Samples of transferred SVF-gel were harvested and examined histologically. All patients showed improvements in facial augmentation and contour. Patients in the SVF-gel group experienced mild postoperative swelling and a low secondary surgery rate (10.9%). Assessment of patient-rated satisfaction on a 5-point Likert scale found that 77.3% of patients in the SVF-gel group were satisfied (54.5%) or very satisfied (22.8%) with their outcomes. By comparison, 53.8% of patients who underwent conventional lipoinjection were satisfied (48.7%) or very satisfied (5.1%). Moreover, SVF-gel showed effective antiwrinkle and skin rejuvenation effects. Hematoxylin-eosin staining showed a normal adipose tissue structure in transferred SVF-gel. Stromal vascular fraction gel is effective for both volumization and rejuvenation, and may be superior to conventional lipoinjection for facial recontouring.

A Novel Naphthyridine Derivative, 3u, Induces Necroptosis at Low Concentrations and Apoptosis at High Concentrations in Human Melanoma A375 Cells.

Naphthyridine derivatives are a widely-used class of heterocycles due to their pharmacological activities. A novel compound (10-Methoxy-1,2,3,4-tetrahydrobenzo(g)(1,3) diazepino(1,2-a)-(1,8)naphthyridin-6-yl)(phenyl) methanone (named 3u), showed good anticancer activity in the human malignant melanoma cell line A375 via Thiazolyl Blue Tetrazolium Bromide (MTT) assay. After Western blotting confirmed, we found that 3u induces necroptosis at low concentrations and apoptosis at high concentrations via the upregulation of death receptors and scaffold protein in A375 cells. Furthermore, by combining 3u with the caspase inhibitor zVAD-fmk or Receptor Interacting Serine/Threonine Kinase 1 (RIP1) kinase inhibitor Necrostatin-1 (Nec-1), we found that the activity of caspase-8 was the crucial factor that determined whether either apoptosis or necroptosis occurred. The results indicate that 3u should be considered as a potential chemical substance for melanoma treatment.

Geophysical constraints on microbial biomass in subseafloor sediments and coal seams down to 2.5\xa0km off Shimokita Peninsula, Japan

To understand the ability of microbial life to inhabit a deep subseafloor coalbed sedimentary basin, the correlation between fluid transport properties and the abundance of microbial cells was investigated based on core samples collected down to about 2.5 km below the seafloor during the Integrated Ocean Drilling Program Expedition 337 off the Shimokita Peninsula, Japan. The overall depth profiles for porosity and permeability exhibited a decreasing trend with increasing depth. However, at depths greater than 1.2 km beneath the seafloor, the transport characteristics of the sediments were highly variable, with the permeability ranging from 10−16 to 10−22 m2 and the pore size ranging from < 0.01 to 100 μm. This is mainly attributed to the diversity of the lithology, which exhibits a range of pore sizes and pore geometries. Fracture channels in coal seams had the highest permeability, while shale deposits had the smallest pore size and lowest permeability. A positive correlation between permeability and pore size was confirmed by the Kozeny-Carman equation. Cell abundance at shallower depths was positively correlated with porosity and permeability, and was less strongly correlated with pore size. These findings suggest that one of the factors affecting the decrease in microbial cell abundance with increasing depth was a reduction in nutrient and water supply to indigenous microbial communities as a result of a decrease in porosity and permeability due to sediment compaction. Anomalous regions with relatively high cell concentrations in coal-bearing units could be explained by the higher permeability and larger pore size for these units compared to the surrounding sediments. Nutrient transport through permeable cleats in coal layers might occur upwards toward the upper permeable sandstone layers, which are well suited for sustaining sizable microbial populations. Conversely, impermeable shale and siltstone with small pores (< 0.2 μm, which is smaller than microbial cell size) may act as barriers to water and energy-yielding substrates for deep microbial life. We propose that the pore size and permeability govern the threshold for microbial habitability in the deep subseafloor sedimentary biosphere.

Increasing cell concentration does not affect specific ferrous iron oxidation rate in a continuously stirred tank bioreactor

Microbial oxidation of ferrous to ferric iron allows efficient oxidative processing of sulfide minerals under ambient conditions. This study determined the effect of cell concentration of a mixed mesophilic microbial culture on iron oxidation rate, and evaluated if there was a cell concentration threshold that dictates a maximal volumetric iron oxidation rate. A bioreactor with feedback-loading of ferrous media was operated at 30 °C to maintain a redox potential of +480 mV vs. Ag/AgCl at pH of 1.3. A positive and linear correlation (R2 = 0.955) between the cell concentration (6.8 × 107–7.1 × 109 cells mL−1) and volumetric biological iron oxidation (up to 6.9 g L−1 h−1) was observed. The specific iron oxidation was not affected by cell concentration, and no biocatalytic threshold was observed. This indicated that a high cell concentration can be used to achieve a high volumetric iron oxidation rate, enabling the use of a compact reactor size.

Adhesion of Rhodococcus ruber IEGM 342 to polystyrene studied using contact and non-contact temperature measurement techniques

Adhesion of industrially important bacteria to solid carriers through the example of actinobacterium Rhodococcus ruber IEGM 342 adhered to polystyrene was studied using real-time methods, such as infrared (IR) thermography and thermometry with platinum resistance (PR) detectors. Dynamics of heat rate and heat production was determined at early (within first 80min) stages of rhodococcal cell adhesion. Heat rate was maximal (1.8 × 10-3-2.7 × 10-3W) at the moment of cell loading. Heat production was detected for the entire length of adhesion, and its dynamics depended on concentration of rhodococcal cells. At high (1 × 1010CFU/ml) cell concentration, a stimulative (in 1.7 and 1.4 times consequently) effect of polystyrene treatment with Rhodococcus-biosurfactant on the number of adhered rhodococcal cells and cumulative heat production at rhodococcal cell adhesion was revealed. The values of heat flows (heat rate 0.3 × 10-3-2.7 × 10-3W, heat production up to 8.2 × 10-3J, and cumulative heat production 0.20-0.53J) were 5-30 times higher than those published elsewhere that indicated high adhesive activity of R. ruber IEGM 342 towards polystyrene. To analyze experimental results and predict effects of boundary conditions on the temperature distribution, a mathematical model for heating a polystyrene microplate with distributed heat sources has been developed. Two independent experimental methods and the numerical modeling make it possible to verify the experimental results and to propose both contact and non-contact techniques for analyzing kinetics of bacterial adhesion.

Toxic dinoflagellates produce true grazer deterrents.

Many phytoplankton species produce toxic substances, but their functional role is unclear. Specifically, it remains uncertain whether these compounds have a toxic or deterrent effect on grazers; only, the latter is consistent with toxins as defensive tools. Here, we show that 10 of 12 species or strains of toxic dinoflagellates were consumed at lower rates than a similarly sized nontoxic dinoflagellate by a copepod. Through video observations of individual prey-grazer interactions, we further demonstrate that the dominating mechanism is through capture, examination, and subsequent rejection of vital cells, that is, a true deterrent effect that offers a straightforward explanation to its evolution. We argue that the diversity of grazer responses to toxic phytoplankton reported in the literature, including toxic effects, and the high diversity of toxin profiles between strains of the same phytoplankton species reflect different stages of an ever-ongoing evolutionary arms race, facilitated by rapid adaptation of grazers to toxic substances. We further argue that defensive toxicity requires a chemical signal exterior to the cell that informs the grazer about the toxicity of the cell. The signal can be the toxin itself or just an aposematic signal of toxicity. In the former case, allelochemical effects may emerge at high cell concentrations as a nonadaptive side effect of a predator defenses.

Semi-Continuous Reverse Membrane Bioreactor in Two-Stage Anaerobic Digestion of Citrus Waste.

The presence of an antimicrobial compound called D-Limonene in citrus waste inhibits methane production from such waste in anaerobic digestion. In this work, a two-stage anaerobic digestion method is developed using reverse membrane bioreactors (rMBRs) containing cells encased in hydrophilic membranes. The purpose of encasement is to retain a high cell concentration inside the bioreactor. The effectiveness of rMBRs in reducing cell washout is evaluated. Three different system configurations, comprising rMBRs, freely suspended cells (FCs), and a combination of both (abbreviated to rMBR–FCs), are incubated at three different organic loading rates (OLRs) each, namely 0.6, 1.2, and 3.6 g COD/(L cycle). Incubation lasts for eight feeding cycles at 55 °C. Methane yield and biogas composition results show that rMBRs perform better than rMBR–FCs and FCs at all three OLRs. Volatile fatty acid profiles and H2 production show that the reactors are working properly and no upset occurs. Additionally, a short digestion time of 4 days can be achieved using the rMBR configuration in this study.

Photo-crosslinked and esterase-sensitive polymersome for improved antitumor effect of water-soluble chemotherapeutics.

To meet the requirements on both delivery stability during blood circulation and fast intracellular release for water-soluble chemotherapeutics encapsulated in polymersomes. A shell photo-crosslinked and esterase-sensitive polymersome (C-PEAMP-D) was constructed based on amphiphilic polyphosphazene PEAMP containing 2-aminoethyl methacrylate. The leakage of doxorubicin hydrochloride (DOX·HCl) was significantly inhibited from 42.27 to 26.64% in 10h and the accelerated intracellular DOX·HCl release occurred responsively to the esterase at high concentration in cancer cells. Consequently, C-PEAMP-D achieved better antitumor efficiency when compared with free DOX·HCl and uncrosslinked PEAMP vesicle. We provided a strategy to conquer drug leakage in systemic circulation and trigger enzyme-sensitive drug release inside cancer cells for improving oncotherapy outcome of water-soluble chemotherapeutics.

Glutathione-responsive self-delivery nanoparticles assembled by curcumin dimer for enhanced intracellular drug delivery

Poor water solubility, short half-life, and low drug efficacy posed a challenge for clinical application of curcumin (CUR). In this work, a kind of CUR prodrug was synthesized by coupling two CUR molecules with a mono-thioether linker for glutathione (GSH)-responsive drug delivery. The synthesized CUR prodrug (CUR-S-CUR dimer) could self-assemble into the homogeneous spherical nanoparticles (NPs) in aqueous solution followed by surface functionalization of trace amounts of DSPE-PEG. These CUR-S-CUR@PEG NPs exhibited a small particle size of ∼100 nm, high CUR-loading content of ∼78 wt%, and good colloid stability. Moreover, the CUR-S-CUR@PEG NPs demonstrated much more efficient cellular uptake and intracellular/nuclear drug delivery compared with free CUR, indicating the advantages of small molecular prodrug assembly. In addition, the GSH with high concentration in tumor cells could trigger the disassembly of CUR-S-CUR@PEG NPs. Furthermore, the cytotoxicity assays indicated that the CUR-S-CUR@PEG NPs exhibited the comparable inhibition effect of tumor cell proliferation with free CUR due to sustained drug release. Therefore, these stimuli-responsive CUR-S-CUR@PEG NPs might have promising potential for highly efficient intracellular drug delivery and controlled drug release in cancer therapy.

Circumcision status at HIV infection is not associated with plasma viral load in men: analysis of specimens from a randomized controlled trial

BackgroundMale circumcision provides men with approximately 60% protection from acquiring HIV infection via heterosexual sex, and has become a key component of HIV prevention efforts in sub-Saharan Africa. Possible mechanisms for this protection include removal of the inflammatory anaerobic sub-preputial environment and the high concentration of Langerhans cells on the inside of the foreskin, both believed to promote local vulnerability to HIV infection. In people who do acquire HIV, viral load is partially determined by infecting partner viral load, potentially mediated by size of infecting inoculum. By removing a portal for virion entry, prior male circumcision could decrease infecting inoculum and thus viral load in men who become HIV-infected, conferring the known associated benefits of slower progression to disease and decreased infectiousness.MethodsWe performed an as-treated analysis of plasma samples collected under a randomized controlled trial of male circumcision for HIV prevention, comparing men based on their circumcision status at the time of HIV acquisition, to determine whether circumcision is associated with lower viral load. Eligible men were seroconverters who had at least one plasma sample available drawn at least 6 months after infection, reported no potential exposures other than vaginal sex and, for those who were circumcised, were infected more than 6 weeks after circumcision, to eliminate the open wound as a confounder. Initial viral load testing indicated that quality of pre-2007 samples might have been compromised during storage and they were excluded, as were those with undetectable or unquantifiable results. Log viral loads were compared between groups using univariable and multivariable linear regression, adjusting for sample age and sexually transmitted infection diagnosis with 3.5 months of seroconversion, with a random effect for intra-individual clustering for samples from the same man. A per-protocol analysis was also performed.ResultsThere were no viral load differences between men who were circumcised and uncircumcised at the time of HIV infection (means 4.00 and 4.03 log10 copies/mL respectively, p = .88) in any analysis.ConclusionCircumcision status at the time of HIV infection does not affect viral load in men.Trial registrationThe original RCT which provided the samples was ClinicalTrials.gov trial NCT00059371.

Response of Microcystis aeruginosa FACHB-905 to different nutrient ratios and changes in phosphorus chemistry

Cyanobacterial blooms are a global problem, with their occurrence tightly tied to nutrient loading. We cultured Microcystis aeruginosa FACHB-905 in growth medium with either inorganic (orthophosphate) or organic (β-glycerophosphate or polyphosphate) phosphorus and at different N:P ratios with 50:1, 30:1, 16:1, 4:1 and 1:4, serving as the phosphorus source. Fluorescence parameters were measured to determine the response of cellular responses to nutrient stress. Scanning electron microscopy (SEM) and estimates of antioxidant activity were employed to examine potential mechanisms of physical change. The results demonstrate that inorganic phosphorus was more bioavailable to M. aeruginosa relative to organic phosphorus in culture. The highest cell concentration (2.21×106 cells/mL), chlorophyll-a (0.39 pg/cell) and phycocyanin (1.57 pg/cell) quotas and high levels of chlorophyll fluorescence parameters (rETR, Ek, α, φPS II and Fv / Fm) were obtained when phosphorus was supplied as K2HPO4 at a N:P ratio of 16–30. Organic sources of phosphorus (β-glycerophosphate and polyphosphate) were bioavailable to M. aeruginosa. In addition, too concentrated orthophosphate (N:P=1:4) resulted in the oxidative stress and lipid peroxidation of cell membrane (identified by the antioxidant system activity), and the photosynthetic activity declined consequently. This study has demonstrated the effects of different phosphorus chemistries and N:P ratios on the cyanobacterial growth, photosynthetic activity and cell physiology, which could be an effective tool for predicting cyanobacterial dominance or N-deficiency in natural lakes (due to the superior ability of cyanobacteria for dissolved N and fix atmospheric N in some cases).

Abstract 4198: 2-Hydroxymelatonin shows antitumor activity against human colorectal cancer cells

Abstract 2-Hydroxymelatonin is a predominant hydroxylated melatonin metabolite in plants. To investigate whether it has potent cytotoxic effects on colorectal cancer cells, four colorectal cancer cell lines, Caco2, HCT116, DLD1, and CT26, were treated with 2-hydroxymelatonin and melatonin. 2-Hydroxymelatonin had a much lower IC50 value than melatonin in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cytotoxic effect of 2-hydroxymelatonin was much stronger than that of melatonin at high concentrations (1000 or 2000 μM) in HCT116, DLD1, and CT26 cells, but only at intermediate concentrations (250 or 500 μM) in Caco2 cells. The cytotoxicity of 2-hydroxymelatonin was induced through activation of the apoptotic signaling pathway, as confirmed by Hoechst staining and Annexin V-FITC/propidium iodide double labeling of cells treated with a lethal dose (1 mM). However, sub-lethal doses of 2-hydroxymelatonin inhibited the invasive ability of Caco2 cells. Epithelial-mesenchymal transition (EMT) markers were significantly regulated by 2-hydroxymelatonin. Overall, the anti-cancer activity of 2-hydroxymelatonin is more potent than that of melatonin. Taken together, 2-hydroxymelatonin exhibits potent anti-cancer activity against human colorectal cancer cells via induction of apoptosis and inhibition of EMT. Citation Format: Yi Yang, Rui Zhou, So-Yeon Park, Kyung Keun Kim, Hangun Kim. 2-Hydroxymelatonin shows antitumor activity against human colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4198.

Construction of glucose and H2O2 dual stimuli-responsive polymeric vesicles and their application in controlled drug delivery

Herein, glucose and H2O2 stimuli-responsive vesicles are constructed based on host–guest interaction between a diblock copolymer, poly(ethylene glycol)-b-poly[3-acrylamidophenylboronic acid-co-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl acrylate], (PEG-b-P(PBA-co-PBEM), BCP for short) and α-cyclodextrin. In the presence of glucose, the vesicles are transformed to giant swollen spherical micelles because of the formation of a negatively charged tetravalent form between phenylboronic acid and glucose. On the other hand, the vesicles are totally disassembled when they are exposed to H2O2, which is due to the H2O2-mediated degradation of the pendant phenylboronic acid pinacol ester. The glucose and H2O2 stimuli-responsive vesicles are then applied in the controlled release of water-soluble anticancer drug, doxorubicin hydrochloride (DOX). Upon external stimuli, the DOX displays a faster release rate than that without stimuli. Moreover, the polymeric vesicles show an excellent cytocompatibility toward MCF-7 cells, and the drug-loaded vesicles exhibit a lower cytotoxicity than free drug toward cancer cells. The drug-loaded vesicles can be taken up by MCF-7 cells and further release the DOX in cancer cells due to the high glucose and H2O2 concentration in tumor cells, while they have negligible effect on normal cells, which may be important for applications in the therapy of cancers as a controlled-release drug carrier.

Imeglimin Protects INS-1 Cells and Human Islets against High Glucose– and High Fructose–Induced Cell Death by Inhibiting the Mitochondrial PTP Opening

Imeglimin (IME) is a novel glucose-lowering agent improving insulin secretion in response to glucose and insulin sensitivity by targeting mitochondrial bioenergetics. IME is currently in phase 3 in Japan. The toxicity of high glucose or fructose concentrations in INS-1 cells was linked to the opening of the permeability transition pore (PTP), a mitochondrial channel involved in cell death. IME has been shown to prevent PTP opening in human endothelial cells under oxidative stress. This study investigated whether IME could also prevent PTP opening and cell death induced by high glucose or fructose concentrations in INS-1 cells and human pancreatic islets. PTP status in intact cells was assessed by confocal microscopy by measuring mitochondrial membrane potential (TMRM) and NAD(P)H (autofluorescence). Cell viability was measured by flow cytometry. In INS-1 cells and human islets, 30 mM Glucose or 2.5 mM Fructose for 24h led to PTP opening (increase in the NAD(P)H/TMRM ratio), this phenomenon being prevented by 100µM IME. Compared to normal glucose concentration (100%), cell viability significantly decreased (p&amp;lt;0.05) in cells exposed to 30 mM Glucose (76±5% and 47±18% in INS-1 cells and human islets, respectively) and to 2.5 mM Fructose for 72h (78±3% and 35±11% in INS-1 cells and human islets, respectively) but remained unchanged when these cells were preincubated with 100µM IME (in 30mM glucose: 94±3% and 98±3% / in 2.5mM fructose: 96±4% and 79±6% in INS-1 cells and human islets, respectively). We conclude that (i) IME is able to prevent high glucose and fructose-triggered cell death through an inhibition of PTP opening and (ii) a PTP-targeted strategy can prevent beta cell death. In addition to its beneficial effect on beta cell function, IME may have the potential to preserve beta cell mass in a dysmetabolic environment via its inhibitory effect on PTP opening. Disclosure S. Lablanche: Other Relationship; Self; Poxel SA. E. Tubbs: None. C. Cottet-Rousselle: None. F. Lamarche: None. A. Moisan: None. V. Persoons: None. P.Y. Benhamou: Consultant; Self; Abbott, Sanofi, Novo Nordisk Inc.. Other Relationship; Self; Eli Lilly and Company, Roche Diabetes Care Health and Digital Solutions. Advisory Panel; Self; Diabeloop S.A.. S. Hallakou-Bozec: None. E. Fontaine: Other Relationship; Self; Poxel SA.

Genetic Analyses of the rbcL and psaA Genes From Single Cells Demonstrate a Rhodophyte Origin of the Prey in the Toxic Benthic Dinoflagellate Ostreopsis

Phagotrophy of the harmful benthic dinoflagellates of the genus Ostreopsis has long been inferred based on observations of food particles present inside the cell, but the prey was not identified yet. This study aimed to investigate seasonal dynamics of the benthic dinoflagellates Ostreopsis spp.in temperate Korean coastal sites, with special emphasis on their phagotrophy. To further identify the prey, the ingested food particles were extracted from single Ostreopsis cells and their rbcL and psaA genes sequences were determined. High concentration of Ostreopsis cells was observed between June and October at all sites, when water temperatures were higher than 19oC, exhibiting a marked temporal seasonality. The percentage of Ostreopsis cells containing the ingested food particles exhibited the large spatial and temporal variations among sampling sites, ranging from undetectable level to 29.5%, and was not always associated with Ostreopsis cell abundance. Phylogenetic analyses using both plastid-encoded rbcL and psaA genes revealed that all sequences obtained from the ingested food particles of Ostreopsis cells grouped within the class Florideophyceae, Rhodophyta. Our result clearly demonstrates that Ostreopsis species consume various macroalgae from the rhodophyta, not protists which have long been thought to be potential prey. The result from this study provides a basis for better understanding mixotrophic behavior and nutritional ecology of the benthic harmful dinoflagellate Ostreopsis species.

Acoustic impedance matched buffers enable separation of bacteria from blood cells at high cell concentrations

Sepsis is a common and often deadly systemic response to an infection, usually caused by bacteria. The gold standard for finding the causing pathogen in a blood sample is blood culture, which may take hours to days. Shortening the time to diagnosis would significantly reduce mortality. To replace the time-consuming blood culture we are developing a method to directly separate bacteria from red and white blood cells to enable faster bacteria identification. The blood cells are moved from the sample flow into a parallel stream using acoustophoresis. Due to their smaller size, the bacteria are not affected by the acoustic field and therefore remain in the blood plasma flow and can be directed to a separate outlet. When optimizing for sample throughput, 1 ml of undiluted whole blood equivalent can be processed within 12.5 min, while maintaining the bacteria recovery at 90% and the blood cell removal above 99%. That makes this the fastest label-free microfluidic continuous flow method per channel to separate bacteria from blood with high bacteria recovery (>80%). The high throughput was achieved by matching the acoustic impedance of the parallel stream to that of the blood sample, to avoid that acoustic forces relocate the fluid streams.

Quantification of cyanobacterial cells via a novel imaging-driven technique with an integrated fluorescence signature

A novel imaging-driven technique with an integrated fluorescence signature to enable automated enumeration of two species of cyanobacteria and an alga of somewhat similar morphology to one of the cyanobacteria is presented to demonstrate proof-of-concept that high accuracy, imaging-based, rapid water quality analysis can be with conventional equipment available in typical water quality laboratories-this is not currently available. The results presented herein demonstrate that the developed method identifies and enumerates cyanobacterial cells at a level equivalent to or better than that achieved using standard manual microscopic enumeration techniques, but in less time, and requiring significantly fewer resources. When compared with indirect measurement methods, the proposed method provides better accuracy at both low and high cell concentrations. It extends the detection range for cell enumeration while maintaining accuracy and increasing enumeration speed. The developed method not only accurately estimates cell concentrations, but it also reliably distinguishes between cells of Anabaena flos-aquae, Microcystis aeruginosa, and Ankistrodesmus in mixed cultures by taking advantage of additional contrast between the target cell and complex background gained under fluorescent light. Thus, the proposed image-driven approach offers promise as a robust and cost-effective tool for identifying and enumerating microscopic cells based on their unique morphological features.

Label-free Neutrophil Enrichment from Patient-derived Airway Secretion Using Closed-loop Inertial Microfluidics.

Airway secretions contain a large number of immune-related cells, e.g., neutrophils, macrophages, and lymphocytes, which can be used as a major resource to evaluate a variety of pulmonary diseases, both for research and clinical purposes. However, due to the heterogeneous and viscous nature of patient mucus, there is currently no reliable dissociation method that does not damage the host immune cells in the patient airway secretion. In this research, we introduce a sample preparation method that uses inertial microfluidics for the patient's immune assessment. Regardless of the heterogeneous fluidic properties of the clinical samples, the proposed method recovers more than 95% of neutrophils from airway secretion samples that are diluted 1,000-fold with milliliters of clean saline. By recirculating the concentrated output stream to the initial sample reservoir, a high concentration, recovery, and purity of the immune cells are provided; recirculation is considered a trade-off to the single-run syringe-based operation of inertial microfluidics. The closed-loop operation of spiral microfluidics provides leukocytes without physical or chemical disturbance, as demonstrated by the phorbol 12-myristate 13-acetate (PMA)-induced elastase release of sorted neutrophils.

Cultivation, characterization, and properties of Chlorella vulgaris microalgae with different lipid contents and effect on fast pyrolysis oil composition.

A systematic study of the effect of nitrogen levels in the cultivation medium of Chlorella vulgaris microalgae grown in photobioreactor (PBR) on biomass productivity, biochemical and elemental composition, fatty acid profile, heating value (HHV), and composition of the algae-derived fast pyrolysis (bio-oil) is presented in this work. A relatively high biomass productivity and cell concentration (1.5g of dry biomass per liter of cultivation medium and 120 × 106 cells/ml, respectively) were achieved after 30h of cultivation under N-rich medium. On the other hand, the highest lipid content (ca. 36wt.% on dry biomass) was obtained under N-depletion cultivation conditions. The medium and low N levels favored also the increased concentration of the saturated and mono-unsaturated C16:0 and C18:1(n-9) fatty acids (FA) in the lipid/oil fraction, thus providing a raw lipid feedstock that can be more efficiently converted to high-quality biodiesel or green diesel (via hydrotreatment). In terms of overall lipid productivity, taking in consideration both the biomass concentration in the medium and the content of lipids on dry biomass, the most effective system was the N-rich one. The thermal (non-catalytic) pyrolysis of Chlorella vulgaris microalgae produced a highly complex bio-oil composition, including fatty acids, phenolics, ethers, ketones, etc., as well as aromatics, alkanes, and nitrogen compounds (pyrroles and amides), originating from the lipid, protein, and carbohydrate fractions of the microalgae. However, the catalytic fast pyrolysis using a highly acidic ZSM-5 zeolite, afforded a bio-oil enriched in mono-aromatics (BTX), reducing at the same time significantly oxygenated compounds such as phenolics, acids, ethers, and ketones. These effects were even more pronounced in the catalytic fast pyrolysis of Chlorella vulgaris residual biomass (after extraction of lipids), thus showing for the first time the potential of transforming this low value by-product towards high added value platform chemicals.