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Primary stakeholders in the Accreditation Council for Graduate Medical Education (ACGME) Milestones Project are: ACGME, Residency Programs, Residents, Fellowship Programs, Fellows, and Certification Boards. The intent of the Milestones is to describe the educational and professional developmental trajectory of a trainee from the first stages of their postgraduate education through the completion of their clinical training. The Milestones 2.0 project includes changes made based on experience with Milestones 1.0. The ACGME solicited volunteers to participate in the development of subspecialty Milestones 2.0. The workgroup was charged with reviewing/making any additions to the four "Harmonized Milestones", developing subspecialty specific milestones for the Patient Care and Medical Knowledge competencies, and creating a supplemental guide. The Milestones were finalized following review of input from an open comment period. The Cytopathology Milestones 2.0 will go into effect July 2021. They include additional subcompetencies in the 4 harmonized competency areas and cytopathology-specific edits to the patient care and medical knowledge subcompetencies. Although the number of subcompetencies has increased from 18 to 21, within each subcompetency, the number of milestone trajectories has decreased. Additionally, within each subcompetency, the wording has been streamlined. A supplemental guide was created and Milestones 1.0 were compared to 2.0; however, curriculum mapping has been left to programs to develop. The ultimate goal of the Cytopathology Milestones 2.0 is to provide better real-time documentation of the progress of cytopathology fellows. The expected outcome is to produce highly competent cytopathologists, improving the care they provide, regardless of the program at which they trained. • The ultimate goal of the Cytopathology Milestones 2.0 is to provide better real-time documentation of the progress of cytopathology fellows. • The expected outcome is to produce highly competent cytopathologists, improving the care they provide, regardless of the program at which they trained. [ABSTRACT FROM AUTHOR]

This study aimed to assess the consistency and replicability of treatment recommendations provided by ChatGPT 3.5 compared to gastrointestinal tumor cases presented at multidisciplinary tumor boards (MTBs). It also aimed to distinguish between general and case-specific responses and investigated the precision of ChatGPT's recommendations in replicating exact treatment plans, particularly regarding chemotherapy regimens and follow-up protocols. A retrospective study was carried out on 115 cases of gastrointestinal malignancies, selected from 448 patients reviewed in MTB meetings. A senior resident fed patient data into ChatGPT 3.5 to produce treatment recommendations, which were then evaluated against the tumor board's decisions by senior oncology fellows. Among the examined cases, ChatGPT 3.5 provided general information about the malignancy without considering individual patient characteristics in 19% of cases. However, only in 81% of cases, ChatGPT generated responses that were specific to the individual clinical scenarios. In the subset of case-specific responses, 83% of recommendations exhibited overall treatment strategy concordance between ChatGPT and MTB. However, the exact treatment concordance dropped to 65%, notably lower in recommending specific chemotherapy regimens. Cases recommended for surgery showed the highest concordance rates, while those involving chemotherapy recommendations faced challenges in precision. ChatGPT 3.5 demonstrates potential in aligning conceptual approaches to treatment strategies with MTB guidelines. However, it falls short in accurately duplicating specific treatment plans, especially concerning chemotherapy regimens and follow-up procedures. Ethical concerns and challenges in achieving exact replication necessitate prudence when considering ChatGPT 3.5 for direct clinical decision-making in MTBs. • ChatGPT 3.5 shows promise as a valuable tool in clinical decision-making. • ChatGPT 3.5 provides case-specific recommendations when provided with sufficient information. • In 83% of cases, ChatGPT 3.5 generates conceptual treatment recommendations that align with the MTB. • ChatGPT 3.5 struggles to generate case-specific recommendations, achieving a 65% concordance rate. [ABSTRACT FROM AUTHOR]

Surgical resection remains the only potentially curative therapy for hilar cholangiocarcinoma (CCC) patients. This meta-analysis aimed to review the current evidence on perioperative and long-term outcomes of routine caudate lobe resection (CLR) for surgical treatment of hilar CCC. A systematic literature search using MEDLINE, EMBASE and Cochrane databases was performed for studies providing comparative data on perioperative and long-term outcomes of patients undergoing resection for hilar CCC with and without CLR. The MINORS score was used for quality assessment. For time-to-event outcomes hazard ratios (HRs) and associated 95% CI were extracted from identified studies, whereas risk ratios (RRs) were calculated for overall morbidity, mortality, and resection margin status. Meta-analyses were carried out using random-effects models. Eight studies involving 1350 patients met the inclusion criteria. The quality of the included studies was low to moderate. CLR resulted in significantly improved overall survival (HR 0.49; 95%CI 0.32–0.75, P < 0.01). Postoperative morbidity (RR 0.93; 95% CI 0.77–1.13; P = 0.48) and mortality (RR 1.01; 95% CI 0.42–2.41; P = 0.99) rates were comparable between both groups. Patients without concomitant CLR were at higher risk for residual tumor at the resection margin (RR 1.40; 95% CI 1.09–1.80; P = 0.01). CLR is associated with improved long-term survival and negative tumor margins after resection of hilar CCC with no adverse impact on perioperative outcomes. CLR might provide the potential to become a standard-of-care procedure in the surgical management of hilar CCC. [ABSTRACT FROM AUTHOR]

Abstract Whenever P is a topological property, we say that a topological space X is star P if whenever U is an open cover of X , there is a subspace Y ⊂ X with property P such that St (Y , U) = X. We study the relationships of star P properties for P ∈ { DCCC , weakly Lindelöf , CCC } with other chain conditions. By using Erdös–Radó's theorem, we also establish several cardinal inequalities for star CCC spaces. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we make some observations on chain conditions and dually properties. In particular, we show that: (1) A subspace X ⊂ ω 1 ω is dually CCC then e (X) ≤ ω and a normal subspace X ⊂ ω 1 ω is DCCC if and only if e (X) ≤ ω ; (2) There is a Tychonoff pseudocompact subspace X ⊂ (ω 1 + 1) 2 which is not dually CCC; (3) In the class of o-semimetrizable spaces, dually separable is self-dual with respect to neighbourhood assignments. As an application, we obtain an example of a CCC normal Moore space which is not dually separable under MA+¬CH; (4) There exists an example of a large normal CCC semi-stratifiable space, which answers a question of Xuan and Song (2018) [21, Question 4.11] ; (5) Every dually separable and monotonically monolithic space is Lindelöf, which gives a partial answer to a question of Alas, Junqueira, van Mill, Tkachuk and Wilson (2011) [2, Question 2.1] ; (6) A dually separable Hausdorff space with a strong rank 1-diagonal has cardinality at most 2 c. The conclusion is also true for regular spaces if we replace "strong rank 1-diagonal" with " G δ -diagonal"; (7) A dually separable ω -monolithic Hausdorff space with a G δ -diagonal has cardinality at most c. [ABSTRACT FROM AUTHOR]

Highlights • Column efficiency up 50% when changing from circular to rectangular with an aspect ratio of 3:1. • Column length can therefore be halved to give the same result. • This leads to lighter more efficient instruments for the consumer. Abstract Increasing column/tubing aspect ratio has been shown in a feasibility study to improve column efficiency when operating in reversed phase mode. This paper contains a thorough investigation on how increases in mobile phase flow and centrifugal force field affect stationary phase retention and column efficiency (as measured by the resolution between adjacent peaks) for columns wound with rectilinear tubing of different aspect ratio. The study uses a Mini CCC instrument operating from 1500 to 2100 rpm (126–246 g) to compare three columns with the same cross-sectional area but different aspect ratio – rectangular horizontal (force field perpendicular to the flat side – aspect ratio 3.125); square (aspect ratio 1.0) and rectangular vertical (flat side parallel with force field – aspect ratio 0.32). Columns are compared by measuring stationary phase retention, resolution and normalized resolution for 3 different mobile phase flow rates 2, 4 and 8 ml/min in both normal phase and reversed phase modes. The results with rectilinear tubing are compared to conventional circular tubing with the same cross-sectional area. The results show that resolution increases with aspect ratio and that at the highest aspect ratio the highest flow rate can maintain a high efficiency only if the highest g-field of 246 g is used. When comparing the rectangular horizontal tubing which gave the best results with conventional circular tubing with the same cross-sectional area a 45% improvement was found in reversed phase mode and a 51% improvement in normal phase mode over the conventional circular cross-section tubing. In other words, a rectangular horizontally wound bobbin with half the length of tubing can achieve the same result as a circular one. These are very significant results for halving separation times analytically or enabling designers to produce new instruments of the same capacity with a much-reduced size. [ABSTRACT FROM AUTHOR]

Highlights • Rectangular horizontal tubing has a number of benefits. • Column capacity can be doubled by using thinner wall tubing. • Packing efficiency is significantly increased. • Retention is significantly increased. • There is a 50x increase in throughput compared to conventional circular tubing. Abstract This paper builds on the fact that high aspect ratio rectilinear tubing columns of the same length and outside dimensions can double column efficiency. It demonstrates that further improvements in efficiency can be made by using rectilinear tubing columns with half the wall thickness thus replacing heavy PTFE with light solvent systems and producing lighter higher capacity columns. Increases in sample loading/throughput of up to 55x are demonstrated by comparing the separation of Honokiol and Magnolol using a Hexane: Ethyl Acetate: Methanol: Water (5:2:5:2) phase system with the new thin wall rectilinear column (56 mL, 30 mL/min, 2.1 g/h in 6.5 min.) with the original optimization performed using a conventional DE-Mini column (18 mL, 0.8 mm bore circular PTFE tubing, 2.5 mL/min, 0.038 g/h in 45 min.). Honokiol is currently going through first phase clinical trials as an anti-lung cancer therapy where preparative countercurrent chromatography was used for its manufacture. To be competitive in the future it is important for the technology to become more efficient. This is the first big step in that direction. [ABSTRACT FROM AUTHOR]

Precipitation during post-homogenization cooling has been studied. A Particle Size Distribution (PSD) based numerical model has been developed to predict diffusion based nucleation, growth and coarsening of plate-like precipitates. The precipitation of S (Al 2 CuMg), η(MgZn 2 ), T(Al 2 Mg 3 Zn 3 ) and θ(Al 2 Cu) phases is predicted for an Al-6.2Zn-2.3Cu-2.35Mg-0.13Zr alloy. These phases have been experimentally observed in a lab-scale furnace cooled sample. The effect of cooling rates and compositions on the precipitation reactions during cooling are studied. A cooling rate >500 °C/h which lead to precipitates <0.6 μm in size, lower volume fractions of all phases and a composition of 6–8% Zn, 1–1.5% Cu and ∼2% Mg has been suggested for easily extruded microstructures with good mechanical properties. The Continuous Cooling Curves (CCC) and Time Temperature Transformation (TTT) curves have been predicted for AA7050. [ABSTRACT FROM AUTHOR]

The 9th International Countercurrent Chromatography Conference (CCC 2016) was held at Dominican University near Chicago, IL (USA), from August 1st–3rd, 2016. The biennial CCC 20XX conferences provide an opportunity for countercurrent chromatography and centrifugal partition chromatography (CCC/CPC) manufactures, marketers, theorists, and research scientists to gather together socially, learn from each other, and advance countercurrent separation technology. A synopsis of the conference proceedings as well as a series of short reviews of the special edition articles is included in this document. Many productive discussions and collegial conversation at CCC 2016 attested to the liveliness, connectivity, and productivity of the global countercurrent research community and bodes well for the success of the 10th conference at the University of Braunschweig, Germany on August 1–3, 2018. [ABSTRACT FROM AUTHOR]

In this study, a Ti/Zr/V conversion coating (TZVCC) was deposited on the surface of aluminum alloy 6063 (AA6063) as an alternative of the chromate conversion coating (CCC). Both the TZVCC treated AA6063 (TZVCC/AA6063) and CCC treated AA6063 (CCC/AA6063) were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and contact angle measuring device. The anti-corrosion performance of the TZVCC/AA6063 and CCC/AA6063 was evaluated by electrochemical measurements and neutral salt spray tests. It showed that both the surface roughness and surface free energy of the AA6063 were significantly increased after TZVCC treatment. The anti-corrosion performance of TZVCC/AA6063 was superior to that of CCC/AA6063. In addition, the effects of the TZVCC and CCC on the adhesion properties and anti-corrosion performance of epoxy coating applied on samples were examined by pull-off tests and electrochemical impedance spectroscopy (EIS). The dry, wet and recovery adhesive strengths of the epoxy coating on TZVCC treated samples (epoxy coated TZVCC/AA6063) were very close to those of epoxy coating on CCC treated ones (epoxy coated CCC/AA6063). The epoxy coated TZVCC/AA6063 showed better corrosion resistance than the epoxy coated CCC/AA6063 and epoxy coated AA6063. [ABSTRACT FROM AUTHOR]

In this paper, we prove that the cardinality of a space X with a symmetric g -function such that ∩ { g 2 ( n , x ) : n ∈ ω } = { x } is at most c if X satisfies one of the following conditions: (1) X has countable chain condition; (2) X is star countable (even star σ -compact); (3) X is DCCC (defined below) and normal space. We also prove that if X is a DCCC space with a symmetric g -function such that ∩ { g 3 ( n , x ) : n ∈ ω } = { x } then the cardinality of X is at most c . Finally, we make some observations on Moore spaces. [ABSTRACT FROM AUTHOR]

The choice of an appropriate combination of stationary phase and mobile phase is essential in any purification technique. To expedite this task, we use automated method screening, typically with high performance liquid chromatography (HPLC), to reduce the time to develop a scalable purification process. We have extended this approach to countercurrent chromatography (CCC) and describe a custom-configured system using automation to execute the solvent screening process. We also present results from three examples of method transfer from analytical to preparative scale using CCC systems from two different manufacturers. [ABSTRACT FROM AUTHOR]

Chloride (Cl − ) is an essential plant nutrient but under saline conditions it can accumulate to toxic levels in leaves; limiting this accumulation improves the salt tolerance of some crops. The rate-limiting step for this process – the transfer of Cl − from root symplast to xylem apoplast, which can antagonize delivery of the macronutrient nitrate (NO 3 − ) to shoots – is regulated by abscisic acid (ABA) and is multigenic. Until recently the molecular mechanisms underpinning this salt-tolerance trait were poorly defined. We discuss here how recent advances highlight the role of newly identified transport proteins, some that directly transfer Cl − into the xylem, and others that act on endomembranes in ‘gatekeeper’ cell types in the root stele to control root-to-shoot delivery of Cl − . [ABSTRACT FROM AUTHOR]

Counter-current chromatography (CCC) has been widely used as a preparative separation method to purify natural products from plant extracts and fermentation broths. Traditionally, throughput optimization in CCC has focused on sample concentration and sample volume. In this paper sample injection was considered as consisting of three variables: injection flow rate, post-injection flow rate and sample solvent. The effects of these parameters were studied using a honokiol purification from a Magnolia officinalis bark extract as a case study aiming to achieve the highest throughput/yield ratio for greater than 99% purity of this potential anti-cancer drug obtained for submission to the Chinese FDA. An injection method was established that increased the throughput of honokiol by 46.5% (from 3.05 g/h to 4.47 g/h), and decreased the solvent consumption of mobile phase and stationary phase per gram of honokiol by 40.0% (from 0.68 L/g to 0.41 L/g) and 48.4% (from 0.40 L/g to 0.21 L/g) respectively. These results show the importance of understanding the whole injection process when optimizing a given CCC separation. [ABSTRACT FROM AUTHOR]

CCC systems are the state of the art method for an assessment of the achieved compaction success with vibratory rollers. However, CCC systems were not available for oscillatory rollers, which differ from vibratory rollers not only in their construction, but also in their motion behaviour and way of dynamically loading the soil. Experimental field tests were performed to analyse the motion behaviour of an oscillatory drum and a CCC value for oscillating rollers is presented based on empirical observations and a semi-analytical modelling of the drum-soil interaction. Moreover, the algorithm of the CCC value is tested on measurement data of the experimental field tests and the influence of weak spots on the CCC values is investigated. [ABSTRACT FROM AUTHOR]

To improve the separation capability of CCC, a novel solid-liquid two-stationary phases CCC (ASP-CCC) column was prepared employing graphene oxide (GO) conjugated poly-dopamine (PD) coating (GO/PD) as auxiliary stationary phase (ASP). The results of Scanning electron microscopy (SEM), contact angle and X-ray photoelectron spectroscopy (XPS) indicated that nanostructured GO and PD were successfully grafted on the inner wall of the PTFE column. Three alkaloid compounds were selected as the target analytes to evaluate the performance of the novel column. Because of the intermolecular force (hydrogen bond, electrostatic interaction and π–π interaction) between the ASP and model compounds, three analytes were well separated with this novel ASP-CCC column. Additionally, the novel column exhibited higher stationary phase retention ratio, about 8%, than original column without changing the chromatographic condition. Furthermore, the eluotropic sequence of analytes on novel column was in accordance with that in the original column. This suggested that the novel column is a CCC column with auxiliary stationary phase (ASP) in its own right, and the present separation mode is the combination of partition chromatography and adsorption chromatography. [ABSTRACT FROM AUTHOR]

Bench-scale experiments and Aspen Plus™ simulations document full-scale, steady-state performance of the external cooling loop cryogenic carbon capture (CCC-ECL) process for a 550 MW e coal-fired power plant. The baseline CCC-ECL process achieves 90% CO 2 capture, and has the potential to capture 99+ % of CO 2, SO 2, PM, NO 2 , Hg, and most other noxious species. The CCC-ECL process cools power plant flue gas to 175 K, at which point solid CO 2 particles desublimate as the flue gas further cools to 154 K. Desublimating flue gas cools in a staged column in direct contact with a cryogenic liquid and produces a CO 2 -lean flue gas that warms against the incoming flue gas before venting. The CO 2 /contacting liquid slurry separates through a filter to produce a CO 2 stream that warms to 233 K and partially flashes to provide a CO 2 -rich product. The CO 2 –rich product (99.2%) liquefies under pressure to form a product for enhanced oil recovery (EOR) or sequestration. All contacting liquid streams cool and cycle back to the staged column. An internal CF 4 refrigeration cycle transfers heat from melting CO 2 to desublimating CO 2 by cooling contact liquid. An external cooling loop of natural gas or other refrigerant provides the additional heat duty to operate the cryogenic process. The nominal parasitic power loss of operating CCC-ECL is 82.6 MW e or about 15% of the coal-fired power plant’s rated capacity. In different units, the energy penalty of CCC-ECL is 0.74 MJ e /kg CO 2 captured and the resulting net power output is decreased to 467 MW e . Lab- and skid-scale measurements validate the basic operation of the process along with the thermodynamics of CO 2 solids formation. [ABSTRACT FROM AUTHOR]

Rational solvent system selection for countercurrent chromatography and centrifugal partition chromatography technology (collectively known as countercurrent separation) studies continues to be a scientific challenge as the fundamental questions of comparing polarity range and selectivity within a solvent system family and between putative orthogonal solvent systems remain unanswered. The current emphasis on metabolomic investigations and analysis of complex mixtures necessitates the use of successive orthogonal countercurrent separation (CS) steps as part of complex fractionation protocols. Addressing the broad range of metabolite polarities demands development of new CS solvent systems with appropriate composition, polarity ( π ), selectivity ( σ ), and suitability. In this study, a mixture of twenty commercially available natural products, called the GUESSmix, was utilized to evaluate both solvent system polarity and selectively characteristics. Comparisons of GUESSmix analyte partition coefficient ( K ) values give rise to a measure of solvent system polarity range called the GUESSmix polarity index (GUPI). Solvatochromic dye and electrical permittivity measurements were also evaluated in quantitatively assessing solvent system polarity. The relative selectivity of solvent systems were evaluated with the GUESSmix by calculating the pairwise resolution ( α ip ), the number of analytes found in the sweet spot ( N sw ), and the pairwise resolution of those sweet spot analytes ( α sw ). The combination of these parameters allowed for both intra- and inter-family comparison of solvent system selectivity. Finally, 2-dimensional reciprocal shifted symmetry plots (ReSS 2 ) were created to visually compare both the polarities and selectivities of solvent system pairs. This study helps to pave the way to the development of new solvent systems that are amenable to successive orthogonal CS protocols employed in metabolomic studies. [ABSTRACT FROM AUTHOR]

Highlights: [•] Surfactants from four frother families were used to link CCC with HLB. [•] To extend to polyethylene glycol alkyl ethers a revised HLB was introduced. [•] H-ratio, fraction of hydrophilic component derived from 1H NMR spectrum, could substitute for HLB. [•] CCC–H-ratio model permits prediction of bubble size, as illustrated for commercial frothers. [Copyright &y& Elsevier]

Highlights: [•] Impurity separation of honokiol and quercetin by both preparative HPLC and CCC. [•] Several performance parameters of separation were compared. [•] CCC provided larger sample loading, especially for a sample with poor solubility. [•] Six impurities of honokiol including one new compound were isolated. [ABSTRACT FROM AUTHOR]

Abstract: Let be the Pixley–Roy hyperspace of a regular space X, and let . For tightness t and supertightness st, we show the following equalities: [(1)] , [(2)] . The first equality answers a question posed in Sakai (1983) . The inequality is strict, indeed there is a space Z such that . The discrete countable chain condition and weak Lindelöf property of are also investigated. [Copyright &y& Elsevier]

Abstract: Chromatography models, liquid–liquid models and specifically Counter-Current Chromatography (CCC) models are usually either iterative, or provide a final solution for peak elution. This paper describes providing a better model by finding a more elemental solution. A completely new model has been developed based on simulating probabilistic units. This model has been labelled ProMISE (probabilistic model for immiscible phase separations and extractions), and has been realised in the form of a computer application, interactively visualising the behaviour of the units in the CCC process. It does not use compartments or cells like in the Craig based models, nor is it based on diffusion theory. With this new model, all the CCC flow modes can be accurately predicted. The main advantage over the previously developed model, is that it does not require a somewhat arbitrary number of steps or theoretical plates, and instead uses an efficiency factor. Furthermore, since this model is not based on compartments or cells like the Craig model, and is therefore not limited to a compartment or cell nature, it allows for an even greater flexibility. [Copyright &y& Elsevier]

Abstract: The origin of counter-current chromatography is briefly stated, followed by a description of the mechanism of elution of solutes, which illustrates the elegance and simplicity of the technique. The CCC retention equation can be mentally derived from three facts; that a substance with a distribution coefficient of 0 elutes at the mobile phase solvent front (one mobile phase volume); and one with a distribution coefficient of 1 elutes at the column volume of mobile phase; and solutes with higher distribution coefficients elute at additional multiples of the stationary phase volume. The pattern corresponds to the classical solute retention equation for chromatography, V R = V M + K C V S, K C not being limited to integer values. This allows the entire pattern of solute retention to be visualized on the chromatogram. The high volume fraction of stationary phase in CCC greatly enhances resolution. A survey of the names, symbols and definitions of several widely used chromatography and liquid–liquid distribution parameters in the IUPAC Gold Book and in a recent summary in LC–GC by Majors and Carr revealed numerous conflicts in both names and definitions. These will retard accurate dissemination of CCC research unless the discordance is resolved. It is proposed that the chromatography retention parameter, K C, be called the distribution coefficient and that a new biphasic distribution parameter, K Δ(A), be defined for CCC and be called the species partition ratio. The definition of V M should be clarified. V H is suggested to represent the holdup volume and V X is suggested for the extra-column volume. H V and H L are suggested to represent the volume and length of a theoretical plate in CCC. Definitions of the phase ratio, β, conflict and should be clarified. [Copyright &y& Elsevier]

Abstract: This paper explores the bioactive composition of strawberry (Camarosa variety) [Fragaria ×ananassa (Rosaceae Family)] describing its anthocyanin composition and measuring the antioxidant activity (AA) of isolated pigments. Pelargonidin-3-glucoside was the major compound followed by pelargonidin-3-rutinoside and 11 pelargonidin and cyanidin derivatives, determined by LC–DAD–MS. Additionally, delphinidin-3-glucoside, peonidin-3-glucoside, and cyanidin-3-galactoside were tentatively identified for the first time in strawberry. Another original contribution was the identification of 5-carboxypyranopelargonidin-3-glucoside in the Camarosa strawberry variety. We isolated two different fractions with pelargonidin-3-glucoside and pelargonidin-3-rutinoside at 90% and 92% purity, respectively, using CCC. ORAC and FRAP assays showed that pelargonidin-3-glucoside is more active than 3-rutinoside. Thus, the sugar substituent determines AA. Pelargonidin-3-glucoside contributed to 32.61% (ORAC) and 17.58% (FRAP) of the overall AA of the extract. We submitted both the strawberry and the purified anthocyanin fractions to a simulated digestion process. The pelargonidin-3-rutinoside fraction and polymeric compounds maintained their AA. [Copyright &y& Elsevier]

Abstract: Literature lists a number of counter-current chromatography (CCC) models that can predict the retention time and to a certain extent the peak width of a solute eluting from a CCC column. The approach described in this paper distinguishes itself from previous reports by relating all model parameters directly to column dimensions and experimental settings. Most importantly, this model can predict a chromatogram from scratch without resorting to traditional calibration using empirical values. The model validation with experimental results obtained across a range of CCC instruments demonstrated that the solute retention time, peak width, and peak resolution could be predicted within reasonable accuracy. Additionally, the effect of several process parameters, such as mobile phase flow rate, rotational speed of the column or β-value, showed that the model is robust and applicable to a wide range of CCC instruments. Overall, this model proved to be a useful tool for parameter estimation and, most significantly, separation optimisation. [Copyright &y& Elsevier]

Abstract: Vinegars elaborated from white wine can be characterized by their phenolic composition. Indeed, for authenticity purpose, phenolic composition can be used to identify Sherry and Balsamic vinegars. However, the phenolic composition of red wine vinegars has scarcely been studied. Anthocyanin compounds in particular remain largely unknown. This study focuses on the analysis of anthocyanin compounds in red wine vinegar and the effect of acetification with submerged culture on such vinegars. The vinegar used in this study was produced from a young Cabernet Sauvignon wine in a laboratory-scale fermenter. Subsequent analyses of both wine and vinegar included their anthocyanin profile (by LC/MS), and their non-anthocyanin phenolic profile (by LC/DAD). In addition, wine and vinegar anthocyanin extracts were fractionated by CCC to determine the contribution of the fractions to overall antioxidant activity (AA), using ORAC, FRAP and DPPH assays. A total of 20 anthocyanin compounds were identified in the vinegar. As far as we know, this is the first time that anthocyanin-derived pigments (pyranoanthocyanins and ethyl-linked compounds) have been identified in red vinegar in such detail. Moreover, an original contribution of this study is the identification for the first time of catechyl-pyranocyanidin-3-glucoside in vinegar and wine, as well as two anthocyanin compounds not previously reported in vinegar or Cabernet Sauvignon wine: acetyl vitisin B and coumaroyl vitisin B. After the acetification process, vitisin-type and ethyl-linked compounds increased and monomeric anthocyanins, phenolic acids (ferulic acid, caffeic acid and caftaric acid) and flavan-3-ol ((+)-catechin) decreased. Although the proportion by weight of the polymeric compound fraction is similar in wine and vinegar, the AA of these polymers in vinegar is significantly greater (p <0.05). We have also determined for the first time an approximate value of AA for malvidin-3-(6-acetyl)-glucoside isolated from vinegar. [Copyright &y& Elsevier]

Abstract: Predictable scale-up from test tube derived distribution ratios and analytical-scale sample loading optimisation is demonstrated using a model sample system of benzyl alcohol and p-cresol in a heptane:ethyl acetate:methanol:water phase system with the new 18L Maxi counter-current chromatography centrifuge. The versatility of having a liquid stationary phase with its high loading capacity and flexible operating modes is demonstrated at two different scales by separating and concentrating target compounds using a mixture of caffeine, vanillin, naringenin and carvone using a quasi-continuous technique called intermittent counter-current extraction. [Copyright &y& Elsevier]

Abstract: The present study examines the validity of the Dutch Children''s Communication Checklist (CCC) for children in kindergarten in a community sample, in order to assess the feasibility of using it as a screening instrument in the general population. Teachers completed the CCC for a representative sample of 1396 children at kindergarten level, taken from 53 primary schools in The Netherlands. The CCC was also completed for a clinical group consisting of children with SLI in special education. Reliability as measured with internal consistency scores was found to be good for the community sample. With regard to the construct validity, a five-factor second-order factor model was found when the pragmatic subscales were analysed, which provided a reasonable fit. Criterion validity as measured using the concordance between the CCC and teacher opinions was moderate. The children identified by the CCC as having Pragmatic Language Impairment (defined as scoring below the cut off of 132) were often characterized by the teachers as having social–emotional problems, language problems or combined problems. Comparison with a clinical SLI sample showed the pragmatically impaired children in the community sample to have a profile similar to that of the clinical group of children with PLI in special education. The main difference was visible in structural language problems, which were less severe for the PLI group in mainstream education. The results of this study suggest that screening for PLI is indeed possible using the CCC. [Copyright &y& Elsevier]

Abstract: Purpose: To evaluate against Monte-Carlo the performance of various dose calculations algorithms regarding lung tumour coverage in stereotactic body radiotherapy (SBRT) conditions. Materials and methods: Dose distributions in virtual lung phantoms have been calculated using four commercial Treatment Planning System (TPS) algorithms and one Monte Carlo (MC) system (EGSnrc). We compared the performance of the algorithms in calculating the target dose for different degrees of lung inflation. The phantoms had a cubic ‘body’ and ‘lung’ and a central 2-cm diameter spherical ‘tumour’ (the body and tumour have unit density). The lung tissue was assigned five densities (): 0.01, 0.1, 0.2, 0.4 and . Four-field treatment plans were calculated with 6- and 18MV narrow beams for each value of . We considered the Pencil Beam Convolution () and the Analytical Anisotropic Algorithm () from Varian Eclipse and the Pencil Beam Convolution () and the Collapsed Cone Convolution () algorithms from Oncentra MasterPlan. Results: When changing from 0.4 to 0.1 , the MC median target dose decreased from 89.2% to 74.9% for 6MV and from 83.3% to 61.6% for 18MV (of dose maximum in the homogenous case at both energies), while for both PB algorithms the median target dose was virtually independent of lung density. Conclusions: Both PB algorithms overestimated the target dose, the overestimation increasing as decreased. Concerning target dose, the and algorithms appear to be adequate alternatives to MC. [Copyright &y& Elsevier]

Abstract: Rational strategies for the optimization of separations are vital to any chromatographic technique. In counter-current separations (CS), once a suitable solvent system is selected for a given separation, the operator is faced with the task of optimizing the separation through the manipulation of those adjustable operation parameters allowed for by the current CS technology. This study employed a mixture of 21 natural products of varying polarity, molecular mass, and functionality, termed the GUESSmix, as a tool to assess the effectiveness of optimization strategies. The behavior of the GUESSmix was observed in the hexane/ethyl acetate/methanol/water 4:6:4:6 (HEMWat +3) solvent system. The effect of operation parameters on both the elution and extrusion stages of a recently introduced CS methodology, termed elution–extrusion counter-current chromatography (EECCC), was investigated. The resulting chromatograms were plotted with K-based reciprocal symmetry plots (ReS and ReSS), which allow comparison of the K values of significant peaks and assessment of resolution of eluting compounds in the interval 0≤ K ≤ ∞. The operation parameters studied were: (1) the effect of temperature controlled water circulation around the centrifuge; (2) the combination of flow rate and revolution speed; (3) sample loading capacity; (4) the direction of rotation either agreeing with or opposing the direction of coil winding; (5) injection before equilibration, a practice that saves operator time and reduces solvent consumption. The GUESSmix was found to be a highly useful reference mixture to compare and contrast stationary phase retention volume ratios, resolution, K-values, peak shapes, and extrusion characteristics between CS experiments. EECCC is shown to be a robust technique that may be enhanced with appropriate temperature, rpm, flow rate, sample loading, direction of rotation, and injection timing. Plotting ReS[S] chromatograms enables systematic study of CS parameters, which are not reproducibly represented in retention time or volume plots. [Copyright &y& Elsevier]

Abstract: A new Dynamic Extractions Maxi-counter-current chromatography (CCC) centrifuge with a column volume of 18-l has been installed in the Advanced Bioprocessing Centre at Brunel. This instrument has four times the capacity of the 4.6-l Maxi-CCC centrifuge which has been operating robustly for 3 years. Tests using the model sample system benzyl alcohol and p-cresol with a heptane:ethyl acetate:methanol:water (HEMWat) phase system (1.4:0.1:0.5:1.0) show that resolution is almost double with this new high capacity device. Commissioning tests with a mixture of caffeine, K D =0.21; ferulic acid, K D =0.82; umbelliferone, K D =1.2 and vanillin, K D =1.49 using a HEMWat phase system of 1:1.5:1:1.5 on the 9-l column show that resolutions equivalent to analytical instruments will be possible using the full 18-l capacity. They also show that predictable scale-up from simple test tube tests is feasible with knowledge of the stationary phase retention for the planned process scale run. [Copyright &y& Elsevier]

Abstract: There is clearly a need for a model which is versatile enough to take into account the numerous operating modes and pump out procedures that can be used with counter-current chromatography (CCC). This paper will describe a universal model for counter-current chromatography based on counter-current distribution. The model is validated with real separations from the literature and against established CCC partition theory. This universal model is proven to give good results for isocratic flow modes, as well as for co-current CCC and dual flow CCC, and will likely also give good results for other modes such as intermittent CCC. [Copyright &y& Elsevier]

Abstract: Experiments were performed to evaluate whether counter-current chromatography (CCC) could function as an alternative purification method to reversed-phase high-performance liquid chromatography (RP-HPLC) and normal-phase supercritical fluid chromatography (SFC). RP-HPLC and SFC are the routine methods currently used in our high-throughput purification (HTP) facility for the purification of high-throughput organic synthesis (HTOS) libraries and medicinal chemistry reaction mixtures. Pre-equilibration of the solvent mixture layers was not mandatory for effective chromatography when hexanes–ethyl acetate–methanol–water (HEMW) solvent mixtures were used. Key to the use of CCC for high-throughput applications is the ability to effectively select a solvent system appropriate to each library member. Pilot-scale CCC elution time was used to estimate a starting solvent ratio and RP-HPLC retention time was then used to adjust solvent ratios within a particular library. It was also found that dimethyl sulfoxide (DMSO) and DMSO–methanol were suitable as sample injection solvents when using the HEMW solvent systems. [Copyright &y& Elsevier]

Abstract: Maharam algebras are complete Boolean algebras carrying a positive continuous submeasure. They were introduced and studied by Maharam [D. Maharam, An algebraic characterization of measure algebras, Ann. of Math. (2) 48 (1947) 154–167] in relation to Von Neumann’s problem on the characterization of measure algebras. The question whether every Maharam algebra is a measure algebra has been the main open problem in this area for around 60 years. It was finally resolved by Talagrand [M. Talagrand, Maharam’s problem, preprint, 31 pages, 2006] who provided the first example of a Maharam algebra which is not a measure algebra. In this paper we survey some recent work on Maharam algebras in relation to the two conditions proposed by Von Neumann: weak distributivity and the countable chain condition. It turns out that by strengthening either one of these conditions one obtains a ZFC characterization of Maharam algebras. We also present some results on Maharam algebras as forcing notions showing that they share some of the well-known properties of measure algebras. [Copyright &y& Elsevier]

Abstract: The scaling up of the separation of two proteins with an aqueous two-phase system (ATPS) from 176mg with a 500ml laboratory scale centrifugal partition chromatography (CPC) column to 2.2g with a 6.25 litre pilot-scale column is presented. A model sample system of a mixture of lysozyme and myoglobin was chosen for this study using an ATPS system comprising 12.5% (w/w) PEG-1000:12.5% (w/w) K2HPO4. It was found that the maximum sample concentration possible without precipitation was 2.2mg/ml for each constituent. The optimisation of rotor speed, mobile phase flow rate and sample loading was performed on a laboratory-scale device. It was found that a centrifuge speed of 2000rpm (224 ‘g’), 10ml/min mobile phase flow rate with a 43ml (10% of active column volume) sample volume gave optimum operating conditions. This was linearly scaled up to pilot scale by increasing mobile phase flow rate, fraction size and sample loading in the ratio of the system capacities (i.e. 12.5:1). Flow rate was therefore increased from 10ml/min to 125ml/min, fraction size from 10ml to 125ml and sample loading from 43ml to 500ml. Rotor speed however was reduced from 2000rpm on the laboratory device to 1293rpm on the pilot-scale device to maintain the same 224 ‘g’ field in each chamber, as the pilot-scale CPC unit has a larger rotor radius than the laboratory one. Resolution increased from Rs=1.28 on the 500ml rotor to Rs=1.88 on the 6.25 litre rotor, giving potential throughputs in batch mode of over 40g/day. [Copyright &y& Elsevier]

Summary: Elongation of pollen tubes in pistils of Lilium longiflorum cv. Hinomoto after self-incompatible pollination was here found to be promoted by acetylcholine (ACh) and other choline derivatives, such as acetylthiocholine, l-α-phosphatidylcholine and chlorocholinechloride [CCC; (2-chloroethyl) trimethyl ammonium chloride]. Moreover, the elongation was promoted by neostigmine, a potent inhibitor of acetylcholinesterase (AChE; acetylcholine-decomposing enzyme) (EC 3.1.1.7.) and activities of this and choline acetyltransferase (ChAT; acetylcholine-forming enzyme) (EC 2.3.1.6.) in pistils were associated with self-incompatibility. The activity of ChAT was lower after self-incompatible as compared with cross-compatible pollination. Application of cAMP promoted ChAT activities in both cases, whereas activity of AChE in pistils after self-pollination was higher than that after cross-compatible pollination and was suppressed by cAMP in both cases. Furthermore, AChE activity was inhibited by treatment with neostigmine or heating. Our results indicate that the self-incompatibility with self-pollination is due to decrease of ACh and cAMP, causing reduction of ChAT and AC (adenylate cyclase) and concise elevation of AChE and PDE (cAMP phosphodiesterase), and therefore suppressed growth of pollen tubes. [Copyright &y& Elsevier]

Abstract: The crude extract of an Alaskan ethnobotanical plant, Oplopanax horridus, was subjected to counter-current chromatography (CCC), and the selected active regions were evaluated for their synergistic effects with an in vitro model of anti-tubercular efficacy. CCC as a support-free high-resolution separation method was employed to preclude potential irreversible absorption to a solid stationary phase. The microplate Alamar blue assay and the isobole method were used to measure the biological activity and eliminate dose–response dependent errors, respectively. Using the combination of CCC, bioassay and isobole method, significant synergistic effects were observed. Among the entire polarity range, fractions with distribution constant between 0.44 and 0.81 showed the most synergistic enhancement with an increase in potency by 108% for the recombined fractions. [Copyright &y& Elsevier]

Abstract: A multilayer coil of PTFE tubing, which failed after being used each workday for about 3 years in a type J centrifuge, was examined. Two types of defects were found. One, called crazes, occurs throughout the coil and does not leak initially, but may eventually lead to a short, axially oriented slit. Another, called indentations, is seen primarily in the innermost and other nearby layers. They are elongated, about 5mm, indentations, usually on the central side of the tubing. These eventually crack and leak. PTFE tubing is permeable to air and hexane and expands by more than 1% when immersed in hexane, heptane or chloroform for a few days. It is suggested that the crazes result from exposure of the somewhat flexible tubing to the undulating centripetal force field in the coil-planet centrifuge, especially when further softened by solvent absorption. The indentations may result from carriage of the excess tubing length, created by solvent absorption, from the coil periphery to the coil center by the centripetal force field, which continuously travels from the peripheral tail to the central head of the coil. A 1% increase in coil length creates 74cm of excess tubing in the 160-ml coils examined in this study. It is suggested that fluorinated ethylene propylene (FEP) tubing, especially when etched on the outside, may provide more stable CCC coils, since its expansion when exposed to organic solvents is 0.1 or less than that of PTFE. [Copyright &y& Elsevier]

Abstract: In dual-flow counter-current chromatography (DF-CCC), the two immiscible liquids are flowing in opposite directions in the coil. The method allows for the continuous separation of two solutes. In this study a numerical model was developed to allow for the detailed investigation of flow in such columns. The mesh model of the presented DF spiral column was developed in line with an existing experimental model. The paper presents results during the early filling stages for different rotation directions. These clearly illustrate the performance of the developed model by (1) confirming the importance of flowing the lighter phase from tail to head and the heavier phase from head to tail and (2) by visualising mixing waves and the recognised back and forth “swish-swash” motion as present in CCC in that operating mode. [Copyright &y& Elsevier]

Abstract: Application of a mixture of 21 commercially available natural products, termed the GUESSmix, established a standard test that allows for a systematic analysis and comparison of the properties of biphasic solvent systems in counter-current/partition chromatography. Because the GUESSmix is comprised of compounds with varying polarities, functional groups, and structural features, it proves to be a rational method for mapping the optimal resolution polarity range of a particular solvent system. The mapping of optimal resolution polarity ranges of solvent systems provided for the description of the overall optimal resolution polarity range of a solvent system family, comprised of the same solvents in different proportions. By comparing the GUESSmix performance in the individual members of a solvent system family, the solvent system that best functions as the representative of, or portal to, the solvent system families was determined. The GUESSmix also afforded a method to compare the overall optimal resolution polarity ranges of solvent system families. Based on performance of GUESSmix chromatograms, the counter-current chromatography (CCC) properties of a two ternary literature solvent systems, ethyl acetate/n-butanol/water (EBuWat) and t-butylmethylether/acetonitrile/water (terAcWat), were explored in order to contrast and compare their CCC potential. A quaternary solvent system, hexane/t-butylmethylether/acetonitrile/water (HterAcWat), was also formulated and studied. The results indicated that the GUESSmix is fit for the purpose of developing and evaluating CCC solvent system families with desired performance characteristics. [Copyright &y& Elsevier]

Abstract: The pharmaceutical industries are looking for rapid methods of purification and predictable scale-up for their drug development process that will cut their costs and enable them to reduce the time to market. In this paper, recent progress is reviewed in the development and demonstration of two types of industrial scale centrifugal liquid-liquid chromatography: hydrostatic and hydrodynamic. Industrial scale hydrostatic processes by Partus Technologies and Armen Instrument are just emerging. Results demonstrating scalability are presented for hydrodynamic processes by Dynamic Extractions. The review concludes that the time is now right, with this appropriate commercial support, for high performance counter-current chromatography to emerge as a major enabling technology for industry. [Copyright &y& Elsevier]

Abstract: Dual layer coating systems consisting of volatile organic compound (VOC)-based aliphatic polyurethane topcoats and epoxy primers applied to AA2024-T3 substrates pretreated with chromate conversion coating (CCC) are the current mainstay of the U.S. Navy. Government mandates preclude their future use, however, and they are being phased out of service in favor of new VOC-free topcoat and primer high-solids reformulations. The durability of this new formulation to artificial weathering protocol GM9540P was evaluated using transmission-mode and diffuse reflectance Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) imaging, optical and scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) and laser-confocal topography. Extensive blistering of the coating system was observed. Depth-resolved FTIR spectra show a lack of chemical modification of the topcoat layer. Data collected show localized corrosion of the substrate material in the form of pitting, as well as chemical inhomogeneities within the primer layer manifest as regional undercuring of the epoxy matrix. It is hypothesized that barrier failure of the coating/pretreatment system is the result of a cascading series of component-specific failures, notably an apparent shift in the target polydispersity of the prepolymer components of the epoxy primer. [Copyright &y& Elsevier]

Two cDNA isoforms of the NKCC1 secretory cotransporter have been isolated from the European eel. The NKCC1a isoform exhibited mRNA expression in a wide range of tissues in a similar fashion to mammals, whereas NKCC1b was expressed primarily in the brain. The effect of freshwater (FW) to seawater (SW) transfer on NKCC1a expression was dependent on the developmental stage. In non-migratory yellow eels, NKCC1a mRNA expression in the gill was transiently up-regulated 4.3-fold after 2 days but also subsequently by 2.5–6-fold 3 weeks after SW transfer. Gill NKCC1a expression was localised mainly in branchial chloride cells of SW acclimated yellow eels. In contrast to yellow eels, NKCC1a mRNA abundance was not significantly different following SW acclimation in silver eel gill. NKCC1a mRNA abundance decreased in the kidney following SW acclimation and this may correlate with lower tubular ion/fluid secretion and urine flow rates in SW teleosts. Kidney NKCC1a mRNA expression in silver eels was also significantly lower than in yellow eels, suggesting some pre-acclimation of mRNA levels. NKCC1a mRNA was expressed at similar low levels in the middle intestine of FW- and SW-acclimated yellow or silver eels, suggesting the presence of an ion secretory mechanism in this gut segment. [Copyright &y& Elsevier]

: BackgroundBile leakage is one of the frequent and disturbing complications of hepatic resection.: Study designClinical records of the 363 patients who underwent hepatic resections without biliary reconstruction for hepatic cancers between January 1994 and June 2001 were reviewed. Postoperative bile leakage was defined as continuous drainage with a bilirubin concentration of 20 mg/dL or 1,500 mg/d lasting 2 days. Leakage that continued longer than 2 weeks or that required surgical intervention was defined as uncontrollable. Differences in incidence and frequency of uncontrollable leakage for the different types of hepatic resection, tumors, and underlying liver disease were investigated. Outcomes after treatment for uncontrollable bile leakage were also reviewed.: ResultsPostoperative bile leakage occurred in 26 of 363 patients (7.2%). Although the incidence in patients with cholangiocellular carcinoma (3/9 [33%]) was higher (p = 0.03) than in patients with hepatocellular carcinoma, rates of occurrence were similar among the different types of hepatic resection and underlying liver disease. Eight of the 26 patients (31%) had uncontrollable leakage. Two patients required reoperation to control leakage; one of these developed hepatic failure and died 2 months after surgery. Four patients underwent endoscopic nasobiliary drainage 21 to 34 days after hepatectomy, and the leakage resolved within 3 to 21 days. Fibrin glue sealing was effective in two patients whose leaking bile ducts were not connected to the common bile duct.: ConclusionsAlthough meticulous surgical technique can minimize the risk of postoperative bile leakage, some instances of leakage are unavoidable. Nonsurgical treatments, such as nasobiliary drainage or fibrin glue sealing, are preferable to reoperation. [Copyright &y& Elsevier]

The accurate determination of Hamaker constant of humus is the basis for understanding the colloidal behavior of humus in environment. However, the determination of the Hamaker constant of humus is still a challenge because of its low value in Hamaker constant. In this study, a method for determining the Hamaker constant of humus with dynamic light scattering (DLS) technique has been established. Firstly, the Hamaker constants of the mixture colloids of "humic acid (HA) + montmorillonite (Mont, with known high Hamaker constant)" with different HA/Mont ratios were determined by DLS technique. Secondly, the mathematic relationship of the Hamaker constant (A) of the mixture colloid and HA content (y with percentage) was established, and it was A = 13.32 × 10−20 y −0.507 J. From which, finally, the Hamaker constant of HA (when y = 100) was obtained and it was 1.29 × 10−20 J. The validity of the obtained Hamaker constant of HA was confirmed by the comparison of the calculated CCC by adopting the obtained Hamaker constant of HA and the experimentally determined CCC by DLS. The established method in this study can be applied to the Hamaker constant determination of other nano-sized organic materials by DLS. [Display omitted] [ABSTRACT FROM AUTHOR]

We study the star version of selectively ccc spaces. Relations of this class of spaces with some other existing selective properties are discussed. A few examples which make considered spaces different from other spaces are provided. [ABSTRACT FROM AUTHOR]

Bal and Kočinac in [2] introduced and studied the class of selectively star-ccc spaces. A space X is called selectively star-ccc if for every open cover U of X and every sequence (A n : n ∈ ω) of maximal pairwise disjoint open families in X there exists a sequence (A n : n ∈ ω) such that A n ∈ A n for every n ∈ ω and St (⋃ n ∈ ω A n , U) = X. In this paper, we prove that: (1) A selectively star-ccc space is DCCC and a selectively star-ccc perfect space is CCC. (2) There exists a pseudocompact (hence, DCCC) space that is not selectively star-ccc. (3) Every selectively star-ccc subspace of the product of finitely many scattered monotonically normal spaces has countable extent. (4) Every selectively star-ccc subspace of ω 1 ω has countable extent. (5) Under 2 ℵ 0 = 2 ℵ 1 , there exists a selectively star-ccc normal space having a regular closed G δ -subset which is not selectively star-ccc. (6) Every first countable selectively star-ccc space with a G δ -diagonal has cardinality at most c. (7) Every selectively star-ccc space with a rank 2-diagonal has cardinality at most c. [ABSTRACT FROM AUTHOR]

• Mixing zone was located near to the proximal key node and traveled through the column. • Every parts of bobbin went through a mixing-settle process. • Phase distribution hardly changed once hydrodynamic has been established. • The sample diffusion was quite fast after injection which might cause low efficiency. In counter-current chromatography (CCC), the hydrodynamic motion of a two-phase solvent system in the column/coil is very important. There are some previous visualization studies on CCC using stroboscopic photography. As CCC separation is a continuous liquid-liquid extraction process, observing the distribution and movement of the solvent system on-line will be helpful to understand the hydrodynamic behavior during the whole CCC separation process. In the present study, a high-speed imaging camera was employed to take videos of a running CCC bobbin (visualized continuously on-line). The dynamic motion and phase distribution of conventional quaternary solvent system hexane/ethyl acetate/methanol/water (HEMWat) and ternary solvent system dichloromethane/methanol/water were both investigated. Wave-like mixing was observed in the area where the centrifugal force is minimum in different diameter columns. When the coil rotated, the mixing zone was "fixed" at the minimum centrifugal force position. Several photographs of the rotating coiled tube were taken which revealed that the phase dispersion hardly changes once equilibrium is established. Finally, the sample dispersion process was also recorded. These results will help us to understand the separation process in a CCC column/coil and also present some more interesting questions related to separation efficiency which are shown in discussion part of this paper. [ABSTRACT FROM AUTHOR]

Bal and Kočinac in [2] introduced and studied the class of selectively star-ccc spaces. A space X is called selectively star-ccc if for every open cover U of X and for every sequence (A n : n ∈ ω) of maximal pairwise disjoint open families in X there exists a sequence (A n : n ∈ ω) such that A n ∈ A n for every n ∈ ω and St (⋃ n ∈ ω A n , U) = X. In this paper, we first provide some sufficient conditions for ccc spaces to be selectively 2-star-ccc, which partially answer Problem 4.4 of Bal and Kočinac [2]. We give a Tychonoff example of a pseudocompact selectively 2-star-ccc which is not strongly star-Lindelöf, which gives a positive answer to Problem 4.8 from [2] and Question 3.11 from [16]. We also show that a regular closed G δ -subspace of a Tychonoff pseudocompact selectively star-ccc space may not be selectively star-ccc. We finally prove that the product of a selectively star-ccc space and a Lindelöf space may not be selectively star-ccc. [ABSTRACT FROM AUTHOR]