Continuous Flow Centrifugation Research Articles

Efficiency of five samplers to trap suspended particulate matter and microplastic particles of different sizes

Suspended particulate matter (SPM) plays a major role in nutrient cycles and for the transport of pollutants within local and transboundary water catchments. Obtaining representative SPM samples from rivers, lakes, inland and coastal waters is crucial for quantitative and qualitative chemical analyses to correctly describe the chemical status of a water body. However, a representative sampling of SPM over time is challenging due to the heterogeneity of SPM particles sizes, their non-uniform distribution in rivers, and a variety of sampling devices being in use. Therefore, we investigated the efficiencies of five different sampling devices commonly used in national and international monitoring programs to collect representative SPM samples. We tested three passive sedimentation-based samplers (SBSs: sedimentation box, SB; sedimentation tank, ST; Raetz Sampler, RS), and two active separation techniques (continuous flow centrifuge, CFC; vacuum filtration, VF) in an experimental laboratory setup using in-house SPM standard suspensions (mineral, organic, and microplastic particles) with defined particle sizes. The mass-based efficiencies of the three examined SBSs were 0–66% for the mineral and organic particles <75 μm, where the mean particle sizes of collected samples were always shifted to bigger sizes compared to the initial suspensions. The efficiencies of the three SBSs to collect microplastic particles <80 μm were <20% due to the lower densities of microplastic compared to organic and mineral particles. In contrast to the SBSs, VF and CFC units showed excellent efficiencies >86% for all tested materials, with similar particle size distributions of the sampled material compared to those of the inlet suspensions. In conclusion, SPM sampling efficiencies of sampling units have to be carefully considered and compared to the respective aims of the monitoring approaches, especially when statements are derived from quantitative results on SPM.

The effects of large-volume leukapheresis on hemoglobin, platelet and coagulation in patients with hyperleukocytic leukemia.

This study retrospectively analyzed a total of 86 leukapheresis treatments in 55 patients with hyperleukocytic leukemia (HLL). In the leukapheresis treatments, the monitoring collection (MNC) program in COBE spectra continuous flow centrifuge (CFC) for blood component separator was used. In this study, the white blood cell (WBC) suspension volume collected in leukapheresis treatment were 870.72±208.40 mL, and significantly larger than that reported in previous study. Compared with before leukapheresis, there were no difference in patient with HLL on the peripheral blood platelet (PLT) count and hemoglobin (HGB) levels. The index plasma fibrinogen (FIB) concentration was slightly reduced by leukapheresis, however, it did not affect a lot the maintenance of normal hemostatic function in patients with HLL. Our data provided evidences that large-volume leukapheresis had no obvious effects on HGB level and coagulation functions in patient with HLL. So large-volume leukapheresis by CFC could be widely used in clinic.

Large-scale isolation and purification of yolk immunoglobulin with different purity levels via a combination technique based on high-speed-shear crossflow membrane separation

Yolk immunoglobulin (IgY) is an excellent complement or substitute for mammalian immune globulin G, whose development is severely limited for its difficult isolation and purification. This work provides a combination technique for the large-scale isolation of IgY products with different purity levels to meet the market demand. Four levels (IgY-I to IgY-IV) of IgY products were sequentially separated and purified using water dilution, high-speed-shear crossflow membrane separation, and two-step salting out methods, during which the key limiting factors were optimized through the single factor tests. The IgY-I, with purity and yield of 30.69% and 25.06 mg/mL yolk, met the general demand for immune-fortified food for pets. IgY-II and IgY-III achieved purity of 35.84% and 66.09%, yielding 21.76 and 13.92 mg/mL yolk, respectively. Notably, the purity (96.9%) and yield (6.06 mg/mL yolk) of IgY-IV approximated or even exceeded the level of IgY isolated by IgY purification kits, and its purity was higher than that of the commercially available IgY standards. During the isolation, traditional centrifugation and filtration were replaced by continuous flow centrifugation and high-speed-shear crossflow membrane separation for continuous sample loading and sample concentration (a concentration factor of 85.37%). This is of great significance to shortening processing time, saving costs, and meeting needs of large-scale production. This technique has the advantages of high efficiency, low energy consumption, low cost, environmentally friendly, and friendly to human health by supplying IgY products with different purity levels to meet the market demands and promote the development of IgY-related industries.

Remediation plan of nano/microplastic toxicity in food.

Microplastic pollution is causing a stir globally due to its persistent and ubiquitous nature. The scientific collaboration is diligently working on improved, effective, sustainable, and cleaner measures to control the nano/microplastic load in the environment especially wrecking the aquatic habitat. This chapter discusses the challenges encountered in nano/microplastic control and improved technologies like density separation, continuous flow centrifugation, oil extraction protocol, electrostatic separation to extract and quantify the same. Although it is still in the early stages of research, biobased control measures, like meal worms and microbes to degrade microplastics in the environment have been proven effective. Besides the control measures, practical alternatives to microplastics can be developed like core-shell powder, mineral powder, and biobased food packaging systems like edible films and coatings developed using various nanotechnological tools. Lastly, the existing and ideal stage of global regulations is compared, and key research areas are pinpointed. This holistic coverage would enable manufacturers and consumers to reconsider their production and purchase decisions for sustainable development goals.

Annual pulses of copper-enriched sediment in a North American river downstream of a large lake following the catastrophic failure of a mine tailings storage facility

Failures of mine tailings storage facilities (TSF) can have profound and long-lasting effects on the downstream receiving environment. Virtually all spills to date have been into river systems without large lakes that may buffer downstream impacts. In August 2014, the failure of the Mount Polley copper (Cu)-gold mine TSF in British Columbia, Canada, released ~25 × 106 m3 of water and solids; globally, this is the second largest TSF spill in history. Over 18 × 106 m3 was delivered to Quesnel Lake, which is ~9 km from the TSF and is the third deepest lake in North America, and a crucial habitat for Pacific salmon and trout populations. We determined the sediment-associated Cu concentrations and fluxes in Quesnel River, downstream of the lake, from August 2014 to February 2021 based on the analysis of >400 samples of sediment, mainly collected using a continuous-flow centrifuge. During each winter since the spill, Cu concentrations in the fluvial sediment in the upper reaches of the river (~35 km from the TSF) were elevated relative to regional background concentrations and samples collected before the spill. Maximum Cu concentrations were ~410 mg kg−1 which exceeds Canadian sediment quality guidelines for the protection of aquatic organisms (197 mg kg−1). Monitoring of Quesnel Lake since the spill shows that these annual pulses in the winter are due to resuspension of unconsolidated tailings and sediments at the bottom of Quesnel Lake, during autumnal lake turnover, which become mixed throughout the water column and subsequently flow into Quesnel River. Results show that while large lakes may buffer downstream aquatic systems from contaminated sediment, they may prolong the environmental impact. These findings are crucial in understanding how lake processes may modify the effects of TSF spills on downstream aquatic systems.

Stem-like memory T cells are generated during hollow fiber perfusion-based expansion and enriched after cryopreservation in an automated modular cell therapy manufacturing process

Background aimsModular automation is a flexible and reliable option to build the foundation of a new or evolving process or to introduce automation to a process that is already established. Herein the authors demonstrate that modular automation provides both high-quality and high-yield T-cell products. MethodsCells from three individual donors collected on an automated continuous flow centrifugation system were successfully expanded in a functionally closed, automated, perfusion-based hollow fiber bioreactor. These cells were then prepared for cryopreservation in an automated closed-system device that maintains temperature and aliquots a mixed cell product and cryoprotectant into product bags. Cell product bags were thawed and expanded in flasks. Samples taken throughout this manufacturing process were analyzed for cell phenotype, exhaustion markers and functionality. The proportion of CD4+ and CD8+ T cells was maintained through each step, from pre-expansion and post-expansion to immediately after thaw and 24 h after thaw. ResultsInterestingly, phenotypic markers such as CD45RO, CD45RA and CCR7 evolved throughout the process and stem-like memory T cells emerged as the predominant phenotype in the clinically relevant 24-h post-thaw sample. ConclusionsModular automation supported the generation of stem-like memory T cells that were not terminally exhausted and were able to produce effector cytokines upon restimulation.

Concentrations and fluxes of suspended particulate matter and associated contaminants in the Rhône River from Lake Geneva to the Mediterranean Sea

Abstract. The Rhône River is among the main rivers of western Europe and the biggest by freshwater discharge and sediment delivery to the Mediterranean Sea. Its catchment is characterized by distinct hydrological regimes that may produce annual sediment deliveries ranging from 1.4 to 18.0 Mt yr−1. Its course meets numerous dams, hydro and nuclear power plants as well as agricultural, urban and industrial areas. Moreover, with the climatic crisis we are currently facing, it is proven that the occurrence and the intensity of extreme events (floods or droughts) will increase. Therefore, it is crucial to monitor the concentrations and fluxes of suspended particulate matter (SPM) and associated contaminants to study the current trends and their evolution. In the Rhône River (from Lake Geneva to the Mediterranean Sea), a monitoring network of 15 stations (3 on the Rhône River and 12 on tributaries) has been set up in the past decade by the Rhône Sediment Observatory (OSR) to investigate the concentrations and the fluxes of SPM and associated contaminants as well as their sources. The main purpose of the OSR is to assess the long-term trend of the main contaminant concentrations and fluxes, and to understand their behavior during extreme events, such as floods or dam flushing operations. The dataset presented in this paper contains the concentrations and fluxes of SPM as well as the concentrations and fluxes of several particle-bound contaminants of concern, e.g., polychlorinated biphenyl (PCB), trace metal elements (TME) and radionuclides, the particle size distribution and the particulate organic carbon of SPM. Sediment traps or continuous flow centrifuges were used to collect sufficient amount of SPM in order to conduct the measurements, and data completion was applied to reconstruct missing values. This observatory is on-going since 2011 and the database is regularly updated. All the data are made publicly available in French and English through the BDOH OSR database at https://doi.org/10.15454/RJCQZ7 (Lepage et al., 2021).

Lake snow as a mercury methylation micro-environment in the oxic water column of a deep peri-alpine lake

Hg methylation in the oxic water column of marine environments has been linked to the presence of suspended and settling particles known as marine snow, which acts as a micro-niche for MeHg production. While marine snow has been thoroughly studied, its freshwater counterpart, lake snow, received less attention, even though few works have highlighted its ability to be a micro environment for Hg methylation in freshwater systems. Here we present new data of MeHg and THg concentrations in the lake snow of a deep peri-alpine lake (Lake Geneva, Switzerland-France). Particles were sampled from the lake and from its main tributaries using continuous flow filtration and continuous flow centrifugation, respectively. MeHg concentrations ranged from 0.48 ± 0.09 ng/g to 9.61 ± 0.67 ng/g in the lake particles, and from 0.30 ± 0.08 ng/g to 2.41 ± 0.14 ng/g in tributary particles. Our results suggest that lake snow is a likely micro-niche for Hg methylation, like marine snow, and that this methylation takes place inside the particles with a subsequent diffusion to the water column. Moreover, we propose a conceptual model to explain the MeHg behavior related to the lake snow along Lake Geneva water column and a mass balance model to estimate the time required to reach the steady state of MeHg in the water column. Our calculation indicates that the steady-state is reached after 37 days. This result is compatible with particles residence times from the literature on Lake Geneva. These particles forming the lake snow are probably a major entry point into the lake's food chain.

Serial monitoring of ionised calcium levels in plateletpheresis donors: A study from tertiary care oncology centre in India

BackgroundPlateletpheresis is a safe procedure, and the most common reaction is hypocalcemia which is transient and self-limiting, but it can have an impact on donor experience and donor return rate. AimTo serially monitor the ionized calcium levels of the plateletpheresis donors and to correlate with symptoms of hypocalcemia if any. MethodsIt was a prospective observational study in 126 healthy voluntary donors eligible for plateletpheresis as per the Departmental SOP and after taking written informed consent. Procedures were conducted on continuous flow centrifugation (CFC) and intermittent flow centrifugation (IFC) cell separators. Donor blood samples were collected in pre-heparinized syringes at different intervals to measure ionized calcium levels (iCa++) by venous blood gas analysis (Cobas 221). ResultsThere was a continuous and gradual decrease in iCa++ from start to 30–45 minutes during the procedure; while the levels showed a gradual increase at end of the procedure and reached near the baseline values after 15−30 min of completion of the procedure. The change in iCa++ was statistically significant at 30 min and 45 min (p < 0.05), which was correlated with symptoms of hypocalcemia observed in 32.5 % (41/126) of the donors. Females experienced more symptoms of hypocalcemia as compared to males (p < 0.01). Donors who underwent plateletpheresis on the IFC machine experienced more symptoms of hypocalcemia as compared to the CFC machine (p < 0.05). ConclusionFor donors with persistent symptoms of hypocalcemia which are unrelieved by procedural modifications (reducing blood return rate, citrate infusion rate, etc.) measurement of iCa++ and administration of oral calcium tablets may be considered.

A scalable and highly immunogenic virus-like particle-based vaccine against SARS-CoV-2.

BackgroundSARS‐CoV‐2 caused one of the most devastating pandemics in the recent history of mankind. Due to various countermeasures, including lock‐downs, wearing masks, and increased hygiene, the virus has been controlled in some parts of the world. More recently, the availability of vaccines, based on RNA or adenoviruses, has greatly added to our ability to keep the virus at bay; again, however, in some parts of the world only. While available vaccines are effective, it would be desirable to also have more classical vaccines at hand for the future. Key feature of vaccines for long‐term control of SARS‐CoV‐2 would be inexpensive production at large scale, ability to make multiple booster injections, and long‐term stability at 4℃.MethodsHere, we describe such a vaccine candidate, consisting of the SARS‐CoV‐2 receptor‐binding motif (RBM) grafted genetically onto the surface of the immunologically optimized cucumber mosaic virus, called CuMVTT‐RBM.ResultsUsing bacterial fermentation and continuous flow centrifugation for purification, the yield of the production process is estimated to be >2.5 million doses per 1000‐litre fermenter run. We demonstrate that the candidate vaccine is highly immunogenic in mice and rabbits and induces more high avidity antibodies compared to convalescent human sera. The induced antibodies are more cross‐reactive to mutant RBDs of variants of concern (VoC). Furthermore, antibody responses are neutralizing and long‐lived. In addition, the vaccine candidate was stable for at least 14 months at 4℃.ConclusionThus, the here presented VLP‐based vaccine may be a good candidate for use as conventional vaccine in the long term.

Comparison and uncertainty evaluation of two centrifugal separators for microplastic sampling

For commonly applied microplastic sampling approaches based on filtration, high throughput and no size-discrimination are conflicting goals. Therefore, we propose two efficient centrifugal separators for small microplastic sampling, namely the utilization of a hydrocyclone as well as a continuous flow centrifuge. Thorough method optimization was followed by application in an extensive sampling study to investigate the separators’ retention behavior for particulate plastics from estuarine waters. Microplastic concentrations ranged from 193 to 2072 particles m-3. The most dominant identified polymer types were polypropylene, acrylates, polyvinyl chloride and polyethylene. More than 95% of particles were < 100 µm.For the first time in microplastic research, an expanded uncertainty was calculated according to the “Guide to the expression of Uncertainty in Measurement” (JCGM 100:2008). Bottom-up uncertainty evaluation revealed the different sampling methods (~ 44%), sample replicates (~ 26%) and the different detection techniques (~ 16%) as the major sources of uncertainty. Depending on the number of particles detected in the samples, the relative expanded uncertainty (Urel (k = 2)) ranged from 24% up to > 200% underpinning tremendous importance of sound uncertainty evaluation. Our results indicate that scientist should rethink many “observed patterns” in the literature due to being insignificant and herewith not real.

Detection of Cyclospora cayetanensis in produce irrigation and wash water using large-volume sampling techniques

The recent increase of reported cyclosporiasis outbreaks associated with fresh produce has highlighted the need for understanding environmental transmission of Cyclospora cayetanensis in agricultural settings and facilities. Conducting such environmental investigations necessitates robust sample collection and analytical methods to detect C. cayetanensis in water samples. This study evaluated three sample collection methods for recovery of C. cayetanensis oocysts from water samples during seeded recovery experiments. Two filtration-based methods, dead-end ultrafiltration (DEUF) and USEPA Method 1623.1, were evaluated for oocyst recovery from irrigation water. A non-filter-based method, continuous flow centrifugation (CFC), was evaluated separately for recovery from creek water and spent produce wash water. Median C. cayetanensis recovery efficiencies were 17% for DEUF and 16–22% for Method 1623.1. The DEUF method proved to be more robust than Method 1623.1, as the recovery efficiencies were less variable and the DEUF ultrafilters were capable of filtering larger volumes of high-turbidity water without clogging. Median C. cayetanensis recovery efficiencies for CFC were 28% for wash water and 63% for creek water, making it a viable option for processing water with high turbidity or organic matter. The data from this study demonstrate the capability of DEUF and CFC as filter-based and non-filter-based options, respectively, for the recovery of C. cayetanensis oocysts from environmental and agricultural waters.

Carbon Isotope Composition and Its Variation of Particulate Organic Matter in River Waters from the Kuzuryu River System

Radioactive and stable carbon isotopes (14C and 13C) can serve as powerful tools for studying the dynamics of organic matter in aquatic systems. This study considered the transport of particulate organic matter in a river system, a main river and its tributary with different watershed conditions, using carbon isotopic signatures. The Kuzuryu River system is located at Fukui and Gifu Prefecture in the central part of Japan, and consists of a main river, Kuzuryu River, and its main tributary, the Hino River. River research was conducted at a fixed station in the lower reaches of both rivers during June to October in 2010. Suspended solid samples were collected from 85 L to 141 L of river water using a continuous-flow centrifugation. δ13C of organic matter in riverine suspended solids had –26.3‰ to –24.0‰ for the Kuzuryu River and –27.0‰ to –26.1‰ for the Hino River. The Δ14C values of the Kuzuryu and Hino samples were –168‰ to –87‰ and –209‰ to –143‰, respectively. The Δ14C values of Hino River were depleted in 14C rather than the Kuzuryu River. However, the carbon isotopes have correlations with the water level for both rivers. The differences in the particulate organic matter characteristics are explained by the distribution of paddy fields and forests in each watershed, and the differences in the supply of suspended solids from their watershed due to rainfall.

Evaluation of high‐flow rate continuous‐flow centrifugation and filtration devices for sampling and concentrating fine‐grained suspended sediment

AbstractFine‐grained (&lt;63 μm) suspended sediment is an important vector for transporting contaminants in aquatic systems. Characterization of physical and biogeochemical properties of suspended sediment usually requires bulk samples to assess its quality and to determine its source. Low‐flow rate (~2 to 4 L min−1) continuous‐flow centrifugation (CFC) systems may need a time period from several hours to one day to collect such samples, and thus, due to their low inflow rate, limits application of these devices. A field study was conducted in three different freshwater systems in Manitoba, Canada to examine and compare the performance of two high‐flow rate systems as alternative approaches: the M512 continuous‐flow centrifuge (M512); and continuous filtration using PENTEK 1 μm filtration bags (filtration system). It was determined that the mass collection efficiency (MCE) for the M512 (in absolute terms) was similar to low‐flow rate CFC systems. As with low‐flow rate CFC systems, the M512 preferentially collected particles of a certain size range (i.e., in the case of M512, particles ≥ 0.83 μm) and accordingly this may affect the collection of a truly geochemically and physically representative sample in waters containing a high proportion of finer particles (≤1 μm). Several filtration systems in series improved its MCE performance and, in terms of total collected mass, this configuration appears to be as efficient as the low‐flow rate CFC systems in an equivalent sampling time. The results of this study confirmed that, in nearly all cases, the filtration system collected a representative sample of ambient suspended sediment, in terms of particle size composition, and geochemical and colour properties. In practice, it is suggested that the filtration systems in series have advantages over M512 as the filtration system is more portable and cost‐effective with a lower power demand.

Detection of pathogenic bacteria in large volume food samples using an enzyme-linked immunoelectrochemical biosensor

Increased speed and sensitivity of testing are always desired for the detection of pathogens in foods. Presented a test sample with low microbial analyte concentration, it is an advantage to analyze as much volume as possible of the sample to attain the best limit of detection (LOD). Therefore, a rapid screening method using a novel flow-through immunoelectrochemical biosensor was developed for the detection of pathogenic bacteria (E. coli O157:H7 and Salmonella) in food (ground beef). As the working electrode employed was comprised of a porous, antibody-coated graphite felt electrode that served as both a biorecognition-element coated solid support for capture of targeted pathogens as well as a signal transducer, high volumes of aqueous sample could be rapidly exposed to the solid support via gravity flow. Flow rates as high as 16.7 mL/min and 12.3 mL/min could be achieved for bacterial samples in buffer and 1:4 ground meat (beef) homogenate, respectively, with no significant effect on LOD. Fastest flow rates for beef homogenate, without clogging of the porous electrode as well as reduction in apparent electrochemical interference, was realized with a tandem combination of sample pretreatment strategies that included filtration with glass wool and graphite felt as well as continuous flow centrifugation. The LOD for 10,000 E. coli O157 cells in 5, 60, and 1000 mL of buffer was 2000, 170, and 10 cells/mL, respectively in a total assay time of 3 h whereas the LOD for E. coli O157 was 400 cells/mL in 1:4 beef homogenate.

A Nanoplastic Sampling and Enrichment Approach by Continuous Flow Centrifugation

Substantial efforts have been undertaken to isolate and characterize plastic contaminants in different sample matrices in the last years as the ubiquitous presence of particulate plastic in the environment has become evident. In comparison, plastic particles 90%. In a proof-of-principle setup, it was demonstrated that operating two continuous flow centrifuges sequentially at different rotational speeds bears the potential to enable size- and density-selective sampling of the colloidal fraction. A significant fraction of the spiked nanoplastic particles (76% ± 5% (uc)) could be separated from a model mixture of natural particles with a well-defined mean size of approximately 3 µm. While the certified reference plankton material used here was quantitatively retained in the first centrifuge rotor together with 23.0% ± 2.2% of the effective dose of the spiked nanoplastic, the remaining fraction of the nanoplastic could be recovered in the second rotor (53% ± 5%) and the effluent (24.4% ± 2.4% (uc)). Based on the good retention

Comparative evaluation of four suspended particulate matter (SPM) sampling devices and their use for monitoring SPM quality.

Representative sampling of suspended particulate matter is fundamental for assessing river sediment quality, including the distribution and physicochemical characterisation of particles at different hydrological events. This study compares time-integrated samplers and discrete sampling methods, focusing on (a) the representativeness of the different methods and (b) the comparability between the various sampling techniques. The study investigates whether different sampling devices used under the same conditions can reproduce the annual mean. Two time-integrated sampling techniques (Binnensammler floating collector (BS); self-constructed Phillips sampler (PS)) and two discrete sampling systems (continuous-flow centrifuge (CFC); hydrocyclone (HC)) were compared. The monitoring program (August 2013 to August 2014) was conducted using a 4-week sampling frequency at two different monitoring stations in the Rhine river basin. The analysis of physicochemical parameters included total organic carbon (TOC), particulate phosphorus (PP), grain size distribution (GSD), metals, and organic pollutants (PCBs, HCB, PAH). A nested analysis of variance (ANOVA) was used to evaluate the dependence of suspended matter quality parameters on the sampling method, the sampling device, and the sampling station. According to ANOVA, physical and chemical parameters as well as persistent organic pollutants are homogenous for the time-integrated samplers PS and BS. Comparing PS and the reference technique CFC, only the mean annual concentration of TOC is significantly higher for CFC (5.91%; PS, 4.53%) due to degradation processes. With the exception of TOC, Ni, and GSD, data of BS was comparable with that of CFC. Comparing CFC and HC, there are significant differences for GSD, Zn, and Ni. An analysis of the time series of GSD < 63 μm and sum of PAHs confirms the findings of the nested ANOVA, showing that HC time series display significant differences compared with the other samplers.

Impacts of Clarification Techniques on Sample Constituents and Pathogen Retention.

Determination of the microbial content in foods is important, not only for safe consumption, but also for food quality, value, and yield. A variety of molecular techniques are currently available for both identification and quantification of microbial content within samples; however, their success is often contingent upon proper sample preparation when the subject of investigation is a complex mixture of components such as foods. Because of the importance of sample preparation, the present study employs a systematic approach to compare the effects of four different separation techniques (glass wool, 50 μm polypropylene filters, graphite felt, and continuous flow centrifugation (CFC)) on sample preparation. To define the physical effects associated with the use of these separation methods, a multifactorial analysis was performed where particle size and composition, both pre- and post- processing, were analyzed for four different food matrices including lean ground beef, ground pork, ground turkey and spinach. Retention of three important foodborne bacterial pathogens (Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes) was also examined to evaluate the feasibility of the aforementioned methods to be utilized within the context of foodborne pathogen detection. Data from the multifactorial analysis not only delineated the particle size ranges but also defined the unique compositional profiles and quantified the bacterial retention. The three filtration membranes allowed for the passage of bacteria with minimal loss while CFC concentrated the inoculated bacteria. In addition, the deposition and therefore concentration of food matrix observed with CFC was considerably higher for meat samples relative to spinach. However, filtration with glass wool prior to CFC helped clarify meat samples, which led to considerably lower amounts of solids in the CFC vessel post processing and an increase in the recovery of the bacteria. Overall, by laying a framework for the deductive selection of sample preparation techniques, the results of the study can be applied to a range of applications where it would be beneficial to scientifically guide the pairing of the criteria associated with a downstream detection method with the most advantageous sample preparation techniques for complex matrices such as foods.

Effect of Highvolume Platelet Reduction Therapy on White Blood Cell Count and Hemoglobin Level in Patients with Thrombocytosis

To explore the effect of high volume platelet reduction therapy on the white blood cell (WBC) count and hemoglobin (Hb) level in patients with thrombocytosis. Thirty-two plateletphoreses were performed for patients with thromocytosis by using ELP or MNC program of blood component isolator of COBE spectra continuous flow concentrifugation and the ACD-A preservation solution for blood as blood anticoagulant. In each treatment of patients, 2.5-3.0 tines total blood volume (TBV) were circulated, then the platelet suspension of 1/5-1/4 time TBV was prepared and collected. A single plateletpheresis took (212.53±41.54) minutes in which (8 812.63±2087.15) ml blood were treated, and (798.84±190.77) ml platelet suspension was collected. In the suspension, the platelet count was 4 486.50 (3 058.50-5 279.50)×109/L, containing 3 455.50 (2 288.68-4 226.71)×109. WBC count was 13.79 (10.21-20.72)×109/L, containing 11.90(7.81-14.40)×109. Hemoglobin concentration was (3.28±1.25) g/L，containing (2.62 ± 1.17) g. Before and after plateletpheresis, the patients' platelet count was 1 263.00 (1 052.50-1 807.50)×109/L and (778.83±247.25)×109/L（Z=4.94, P＜0.01), WBC count was 9.96(6.44-14.01)×109/L and 8.59(5.37, 13.12)×109/L (Z=13.31, P＜0.05), Hemoglobin concentration was (112.63 ± 24.56)g/L and (109.55 ± 24.46)g/L (t=1.68，P＞0.05). Using continuous flow centrifugation and blood component separating in plateletpheresis for the patients with thrombocytosis can obviously decrease the high ratio of platelets, and improve the effect of plateletpheresis. The high volume platelet reduction therapy can lead to decrease of WBC count to some alent, degree but WBC count still in the normal range, moreover not affect the hemoglobin level significantly.

Evaluation of continuous flow centrifugation as an alternative technique to sample microplastic from water bodies

The scientific and public interest regarding environmental pollution with microplastic has considerably increased within the last 15 years. Nevertheless, up to now there is no widely applied standard operation procedure for microplastic sampling, resulting in a lack of inter-study comparability. In addition, many studies on microplastic occurrences do not indicate a sound methodological validation of the applied methods and procedures. This study presents an alternative volume-reduced sampling technique to sample the entire load of suspended particulate matter including microplastic particles in natural waters, based on continuous flow centrifugation. For the lab-scale validation of the proposed instrumental setup, six different microplastic types (PE, PET, PS, PVDC, EPS and PP) were used. The particles covered a size range from 1 μm to 1 mm and a density range from 0.94 g mL-1 to 1.63 g mL-1. Recoveries ranged from 95.0% ± 2.3% - 99.1% ± 0.3% for virgin powders and from 96.1% ± 0.6% - 99.4% ± 0.2% (1 SD, n = 2 - 3) for microplastic suspended in river water for 40 days. Gravimetric and microscopic analysis of the effluent indicates efficient removal of microplastic from the suspensions. Static light scattering analysis of the microplastic suspensions prior to and after centrifugation confirmed that no change of the particle size distribution has occurred – neither through aggregation nor through size-discrimination during centrifugation. Moreover, the system was tested in the field and used twice to sample suspended particulate matter from the Elbe estuary directly on site. Based on these first lab-scale experiments, continuous flow centrifugation proves a promising technique bearing potential to alleviate drawbacks such as contamination, filter clogging and particle size-discrimination of commonly used volume-reduced microplastic sampling approaches.