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Multiplex detection of microRNAs is highly desirable in trace analysis of clinical samples for early-stage disease diagnosis. In the present study, we report a new liquid suspension nano-chip technology for multiplex detection of microRNAs by detecting side scatter and fluorescence signals of molecular beacon-modified polystyrene nanoparticles, simultaneously. Polystyrene nanoparticles were encoded by distinguished intensity of scattered light with tunable sizes (120 nm, 200 nm and 280 nm). In the proposed detection system, the fluorescence of 5-carboxyfluorescein was recovered due to the structure change of molecular beacons from hairpin to rod-like shape caused by the hybridization of target microRNAs. The well-designed liquid suspension nano-chip system enabled quantitative detection of three colorectal cancer-related microRNAs with low limits of detection and high sensitivity. More importantly, for simulated clinical samples, three random mixed microRNAs were simultaneously detected by accurately decoding the scattering intensity of polystyrene nanoparticles of different sizes and quantitatively analyzed by fluorescence intensity. This technology provides a washing-free, sensitive, convenient and small loading volume strategy for detecting clinical multiplex nucleic acid samples.

A combined CFD–VOF–DPM method has been used to simulate bubble rising and coalescence phenomenon in low hold-upparticle–liquid suspension systems. The liquid is considered as the primary phase, while particles are considered as the discrete phase. Bubbles or bubble parcels are regarded as the gas phase modeled using the VOF method. On the basis of the independence analysis of grid and time-step sizes, the combined method predicts fluid dynamics accurately with slight discrepancy according to the validation with experimental results. Subsequently, three-phase hydrodynamics are systematically investigated and thoroughly discussed.

The existence of Marangoni flow in an evaporating pure water drop has remained an open question. In this study, we report the occurrence of Marangoni convection within a water drop resting on a copper rod as it evaporates into the air. Through careful preparation of the test liquid suspension, we have observed convective structures inside the water drop. We also developed a mathematical model representing the evaporation system and solved it numerically to further strengthen support for the experimental data. Our study is different from previous studies on droplet evaporation in the sense that we allowed the droplet to evaporate spontaneously in the normal laboratory condition without heating the substrate. The substrate was neither externally heated nor did radiation from the illumination light stimulate a Marangoni flow. The velocities in the midsection of the droplet were measured using particle tracking velocimetry in both the sessile and pendant configurations. The typical velocities in the center of the droplet were found to be 10 mm/s experimentally and even higher velocities (about double that) were predicted by the mathematical model. This high value stands out among the thermocapillary-driven flows observed in an autonomously evaporated drop of water under ambient conditions.

As a new kind of solid/liquid suspension, nanofluid needs to be further explored since its measured thermal conductivity is significantly greater than the classic prediction when containing specially shaped particles, for instance nanorods. Various thermal conductivity models for spherical or tubular nanoparticles based nanofluid have been proposed, but none is specifically responsible for nanorod-based nanofluids. In this paper, a physical model of a nanorod with an interfacial layer in a fluid medium is split apart in axial and radial direction respectively to build various differential equations. And a new thermal conductivity model for nanorod based nanofluids is developed based on the combination of the analytic solutions of those differential equations. The allocation proportion of heat conduction in axial and radial directions in the present model is depended upon the ratio of the flanking and ends (top and bottom) surface area of the nanorod. Finally, the present model and some classic models are compared with the available experimental data retrieved for thermal conductivity of nanorod based nanofluids. And the comparison results show the present model achieves better precision.

Carbon nanotubes (CNT) fibres were printed from liquid suspension. The resulting fibres are highly conductive, with conductivity close to the one of standard CNT fibres, flexible and very versatile. The printed fibres are comparable to fibres that can be gained from direct spinning, carpet spinning and spinning from superacids, but offer broader range of composition and are simpler and safer to produce as no high-temperature equipment and dangerous chemicals need to be used. Any CNT material can be implemented, allowing the use of a variety of CNT structures, different densities of the fibres and various shapes for the final product. Keywords: Carbon nanotubes, Electrical conductivity, Macroassemblies, Fibre, Tape

Microalgae can be used as a raw material for biodiesel production. Monitoring the lipid accumulation process of microalgae is crucial for optimizing the microalgae culture environment and the breeding of microalgae species with a high yield of lipid. Current methods for the detection of the lipid accumulation of microalgae are tedious and require trained professionals. Thus, a fast visual and intuitive approach for the detection of the lipid concentration of microalgae with a living status is desirable for microalgae culture and bioprocess control. In this study, a fast and nondestructive method based on hyperspectral imaging (HSI) was proposed to obtain the concentration and distribution of microalgae lipids from liquid suspension culture. Several data preprocessing, regression and model development methods were tested. Savitzky-Golay data smoothing followed by a competitive adaptive reweighted sampling in a multiple linear regression model performed the best. Finally, a chemical map was provided to visualize the lipid distribution of microalgae in a suspension. The distribution map of microalgae lipids showed a dynamic process of lipid accumulation, which could be useful for the investigation of the mechanism of lipid accumulation in microalgae. Hyperspectral imaging is a promising approach to inspect the lipid concentration of microalgae in an intuitive way, which can be widely used for the screening of strains and monitoring the lipid production in microalgae industries.

A material comprised of chitosan-stabilized silver nanoparticles (nAg-chitosan) was prepared and characterized by UV–vis and TEM. The average diameter of the nAg obtained was 3.4 nm and the particles were well dispersed in the chitosan matrix. The liquid suspension of nAg-chitosan was deposited by the drop-coating method onto a glassy carbon electrode (GCE) surface to build a voltammetric sensor (nAg-chitosan/GCE sensor). The voltammetric sensor was successfully used for the detection of nitrocompounds. Under optimized experimental conditions, a reduction peak current was observed which increased with increasing concentrations of 4-nitrophenol (4-NP) in the range of 0.07 to 2.0 μmol L −1 ( R 2 = 0.994). The visual detection limit was 70 nmol L −1 . At this level of concentration, the sensor was not sensitive to other nitrophenols. For concentrations higher than 0.05 mmol L −1 the sensor was sensitive to the three isomers, namely 2-NP, 3-NP and 4-NP. These findings indicate that the material comprised of chitosan-stabilized silver nanoparticles is a very promising candidate to assemble voltammetric sensors for practical applications in the field of analytical chemistry.

Fungal melanin staining is a problem on many cultural objects, ranging from the French Palaeolithic cave at Lascaux to books and papers in museum collections. Melanin, because it is insoluble and resistant to bleaching, may leave behind undesirable stains long after the fungal infestation has been controlled. Research into removal of melanin stains from paper and other sensitive substrates using industrial biomimetic oxidizing systems has shown considerable success. We studied relative concentration of the bleaching reagents and the reaction kinetics both in liquid suspensions of melanin and on melanized paper samples. Liquid suspension samples were tested for changes in their chemical composition (appearance and relative representation of functional groups and chemical bonds) with FTIR spectrometry. Changes in color of melanized paper samples were investigated with a CIE L*a*b system, where the effectiveness of the treatment (bleaching) was determined as a change in lightness (ΔL). Melanin was oxidized in the liquid suspensions, and the intensity of modification depended on the procedure employed. Bleaching of melanin with the biomimetic copper–pyridine complex proved to be far superior to the effect of white-rot fungal oxidizing enzymes, previously reported on by this group.

We address the clinical application of the suspension type cultured epithelial autografts (CEAs), Keraheal™ (MCTT, Seoul, Korea), along with the effects, application method, merits and demerits thereof. From February 2007 to June 2010, 29 burn patients with extensive burns, participated in the suspension type of CEA clinical test. A widely meshed autograft (1:4-6 ratio) was applied to the wound bed and the suspension type CEA was sprayed with a Tissomat cell sprayer, followed by a Tissucol spray, a fibrin sealant. The patients' (men/women=26/3) median (interquartile ranges) age was 42 (30-49) years old, the burned TBSA was 55 (44-60) %, and the full thickness burn area was 40 (30-46.5) %. The area of Keraheal™ applied was 800 (400-1200) cm(2). The take rate was 96 (90.5-99) % and 100 (98.5-100) % at 2 and 4 weeks after treatment with Keraheal™, respectively. The Vancouver burn scar scale was 5 (4-6.5), 4 (3-6), and 3 (2-4) at 8, 12 and 24 weeks after the Keraheal™ application. Widely meshed autograft must be applied in massive burns but it's take rate is greatly reduced. The CEAs enhance the take rate of a wide meshed autograft in massive burns and allow for grafting wide meshed autograft together with acellular dermal matrix in some cases.

Summary In New Zealand, possums ( Trichosurus vulpecula ) are the main wildlife reservoir for bovine tuberculosis (Tb), which they transmit to livestock. This study investigated oral vaccination with lipid-formulated Mycobacterium bovis BCG and subsequent protection against virulent M. bovis challenge in wild-caught possums. Possums were trapped from the field and either hand-vaccinated and released back into the wild, or acclimatised to captive conditions prior to voluntary uptake of flavoured vaccine. Possums were subsequently exposed to pulmonary challenge with virulent M. bovis , administered either by instillation of a liquid suspension as an intra-tracheal challenge (field animals) or in micro-droplets as an aerosol (captive animals). Field studies indicated that the relative risk of death in wild possums due to Tb was 2.4 times greater in control compared with orally-vaccinated possums, with the vaccine conferring protection to possums in both good and poor body condition. Laboratory studies indicated that oral vaccination conferred protection in cage-acclimatised possums, with >3 log 10 reduction in lung bacterial burdens among vaccinated animals. This study provides evidence that lipid-formulated BCG oral vaccine can provide significant protection to possums in field as well as laboratory conditions, which may favour the use of this formulation as a delivery method for controlling wildlife Tb.

A new giant magneto-impedance (GMI) biosensor prototype based on a glass-coated microwires array is reported. The optimal measurement conditions and the influence of a liquid suspension of commercially available polymer-based magnetic microparticles on the magneto-impedance (MI) response of the array were studied. The relative change in MI response enlarges as the number of the active microwires increases. The highest variation of 35% was found for 10 active microwires, for a current intensity of 10 mA. Some possible applications of the biosensor prototype are outlined.

The fatty acid profile of Nostoc flagelliforme (strains FACHB838 and CCAP1453/33), an edible terrestrial cyanobacterium, at different temperatures (i.e., 15, 20, 25 and 30 °C) and developmental stages (hormogonia, filaments, seriate and aseriate) in liquid suspension culture was investigated. The cyanobacterial species could be classified as Type IIB according to the existing taxonomic system based on fatty acid profiling, due to the presence of C18:3 and the absence of C16:2 and C16:3 fatty acids. Within the temperature range investigated, the content of C18:3n3 increased at the expense of C18:2n3 as temperature decreased, while the fatty acid suites remained unchanged. The degree of fatty acid unsaturation also increased with decreasing temperature, with the highest being 1.28 and 1.37 at 15 °C for the strains FACHB838 and CCAP1453/33, respectively. With respect to the effect of developmental stages, there was a slight variation in fatty acids composition and contents in the two strains without changing the fatty acid suite. At the aseriate stage at 25 °C, the highest C18 fatty acid proportion amounted to 63.17 and 65.08% and the degree of fatty acid unsaturation peaked at 1.32 and 1.31 in the strains FACHB838 and CCAP1453/33, respectively, indicating more long chain unsaturated fatty acids were accumulated at this stage.

Spherical agglomeration is an industrial process traditionally used to separate or recover fine solids dispersed in a liquid suspension through the addition of a second immiscible liquid (binder) which presents an affinity for the solids and is capable of forming small liquid bridges that hold the particles together. Under appropriate physico-chemical conditions, the desired particles can be selectively agglomerated and removed from the slurry. More recently, the spherical agglomeration technique has been used for the manufacture of high value products, such as crystalline pharmaceutical drugs, and is attracting increasing attention in the bioprocessing area. However, spherical agglomeration has yet to reach widespread commercialisation beyond the minerals industry. This is despite the simplicity of the process, the low cost of installation required and the possibility of agglomerating particles down to a few microns in size and is probably due to the lack in understanding of the controlling mechanisms involved. In this paper, a microscale approach to investigate the mechanisms that lead to spherical agglomeration is presented. The geometry and the strength of liquid bridges formed between pairs of particles with diameters in the range 80–130 μm, submerged in a second liquid, are analysed and compared with values predicted by theory.

The evolution and structure of pressure waves of moderate intensity in a liquid suspension with solid particles and gas bubbles were investigated experimentally. The experimental data was generalized on the basis of theoretical relations. It was shown that dispersive and non-linear effects significantly affect wave dynamics.

Adult house flies (Musca domestica) were susceptible (94-100% mortality) to Beauveria bassiana when conidia of the Hf88 isolate were applied to plywood boards at 107 conidia/cm2; a starch dust formulation was more effective than a liquid suspension. Adult flies were also susceptible (90-99% mortality) to this isolate when they were con fined with treated water (108 conidia/ml) or food (108 conidia/100 mg). House fly larvae were not affected by treatments with up to 108 conidia/cm3 of rearing medium. A 2-year survey of house flies cm from New York dairies indicated that most natural infections of house flies occurred in September and October, although prevalence rates never exceeded 1%. Thirteen single-fly isolates obtained during this survey were compared with the Hf88 isolate for virulence against flies; the 2 most virulent isolates were slightly more virulent for flies than for the fly parasitoid Muscidifurax raptor. Incorporation of conidia into a sucrose bait (108 conidia/100 mg) in cages gave high levels of house fly control (78-100% mortality) 5 days after exposure.

The main objective of this work is to review methods for the assessment of bioaerosols and consider some of the problems which arise. This paper investigates the main techniques currently available for sampling and detecting airborne microorganisms, examines a number of factors which can affect their survival, and discusses problems associated with the production of test bioaerosols. Ultimately it is hoped that a better understanding of these will provide a basis for the development of standard assessment protocols for bioaerosols and also help in the establishment of bioaerosol standards. The need for aerobiological monitoring in occupational hygiene, containment of bioprocessing equipment, deliberate release of microorganisms, contamination of food and pharmaceutical products and general scientific research, has been identified. Despite the fact that aerobiological monitoring has wide application and may be carried out to comply with guidelines or regulations there are, at present, no standard protocols for sampling airborne microorganisms. Six criteria, which need to be considered when carrying out any aerobiological monitoring, have been identified and defined. Samplers used to collect bioaerosols are described and areas of their application highlighted. Few have been fully characterised in terms of their inlet or bioefficiencies. Samplers not currently used but which have potential use in bioaerosol monitoring have also been identified and described. A series of microbial assay methods are described in terms of their sensitivity, speed, and their relationship with the choice of sampler. The interdependence of sampling and assay methods is discussed. Methods for the production of bioaerosols, from both liquid suspension and dry powder, are described. Techniques for the controlled production of poly and monodisperse aerosols are discussed. The survival characteristics of microorganisms are considered because they can greatly influence the effectiveness of sampling and assay methods. A number of recommendations and a programme of research work are outlined in order to further the understanding of the characteristics, behaviour, and assessment of bioaerosols prior to consideration of the possible establishment of bioaerosol standards for test purposes.

A new aurone, 4,5-methylenedioxy-6-hydoxyaurone, isolated from chitin-treated liquid suspension cultures of Cephalocereus senilis showed antibacterial activity. The structure of the aurone, cephalocerone, was elucidated by chemical and spectroscopic methods.

Extensive effort has been given to identifying and quantitating the organic genotoxins associated with air-borne particles; however, little is known about the mutagenicity of vapors and gases, especially those associated with ambient air samples. This overview of the literature and recent U.S. Environmental Protection efforts examines some of the critical aspects associated with the bacterial mutagenicity testing of gases and vapors. For example, the sensitivity of the test system depends upon the method of exposure (preincubation, gases over plates, liquid suspension, etc.); and the method of choice appears to depend upon vapor pressure and the solubility of the compound under investigation. Also, the selection of test chamber and other materials is important, since plastic petri dishes have been shown to absorb up to 85% of any haloalkane vapors within an exposure chamber. Investigationshave also shown the importance of exposure rates, method of gas mixing, role of metabolic activation systems, and the occurrence of photo-activation. In ambient studies, the identification and quantitation of volatile organic mutagens is quite difficult; however, due to their abundance these efforts are important.

A theoretical study of laser-induced optical inhomogeneity in suspensions of nonlinear (linear) particles in a linear (nonlinear) liquid is presented. Multiple scattering theory is used to determine the transmission loss and the external self-action arising from the nonlinear scattering process.

Vigorous development of callus was achieved only when the nutrient medium was supplemented with picloram and solidified with gelrite. Gelrite also eliminated tissue and medium discoloration. The callus resulted from intensified activity of the primary thickening meristem of shoot-tip explants. After continous culture for 1.5 years, only a small proportion of the callus cells displayed the normal chromosome number, 3 N = 33, the majority being variable aneuploids. Liquid suspension cultures were established by transfering the relatively friable callus to a constantly shaken liquid medium.

This article summarizes the procedures used at the National Bureau of Standards (NBS) in the certification of SRM 1691, a new submicrometer particle-sizing Standard Reference Material. The mean diameter of the SRM 1691 polystyrene microspheres was accurately measured using two independent micrometrology techniques. One technique, transmission electron microscopy, measured the particles dried and in a vacuum and gave a result of 0.269 ± 0.007 μm for the certified mean diameter. The supporting method, quasi-elastic light scattering, yielded a value of 0.276 ± 0.007 μm for the diameter of the microspheres in liquid suspension. Descriptions of the experimental techniques, data analyses, and sources of error are discussed in the paper. The calibrated microspheres are now available from NBS for use as a primary length standard in the submicrometer size range. Applications include microcontamination measurement in semiconductor processing, atmospheric sampling, and electron-microscope calibration.

15 Cyclohexane epoxide derivatives were synthesized and compared for direct mutagenicity an bacterial toxicity using Salmonella typhimurium strain TA100 in the liquid suspension and spot-test version of the Ames procedure. While no general correlations could be established for position and stereochemistry of the hydroxylated derivatives, an increase in mutagenicity was noted for the presence of electron-withdrawing groups and unsaturation in conjugation with the oxirane groups.

Factors were studied which modify the enzymatic capacity of mouse liver microsomal mixed-function oxidase to convert vinylidene chloride (1.1-dichloroethylene) (VDC) into mutagens in the Salmonella /microsome mutagenicity test. A microsomal fraction incorporated in soft agar layer converted VDC into mutagens during 7 h at a constant rate; these were detected with S. typhimurium TA100. In absence of VDC the enzymatic activity declined gradually to nil after 14 h of incubation at 37°C. The presence of EDTA greatly enhanced the microsome-mediated mutagenicity of VDC and led to prolonged enzymatic viability, but only when liver fractions from phenobarbitone (PB) pretreated mice were used. The efficiency of the plate incorporation assay for the detection of mutagens is discussed in comparison with assays in liquid suspension.

An high sensitivity anemograph, with liquid suspension to make the friction of moving parts as low as possible when winds are light, is described in this paper. The anemograph may operate both as wind-speed and wind-direction recorder; particular attention is payed here to the wind-direction recorder description, particularly the method of avoiding difficulties at the 0–360° discontinuity.

A new technique is devised for the preparation of solution-derived titania gel spheres. The gel sphere preparation process involves the dispersal of the polymerized titanium ethoxide solution into a two-phase liquid suspension in kerosene followed by heating in a microwave oven. This is a simple and fast method for the preparation of xerogel spheres with diameter in the range of tens of micrometers which may be useful in coating technology by plasma-spraying.