Small Amount Of Liquid Research Articles

Robotic Fabrication of Microchannels for Microfluidic Analysis by Hydrogel Molding

Microchannels used for high-precision handling of small amounts of liquids are employed in various fields. However, technical limitations with respect to complex channel structure fabrication exist...

Subphrenic abscess secondary to cervical abscess and fasciitis from dental focus: case report

BackgroundCervical fasciitis is a group of severe infections with high morbimortality. Reports in the literature of patients with cases evolving with mediastinal dissemination of deep cervical abscess are common. However, cases of abdominal dissemination by contiguity are much rarer.Case presentationA 34-year-old Caucasian man presented to the emergency department with a 15-day history of left neck edema, local pain, and fever. Seventeen days prior to presentation, he had undergone odontogenic surgical treatment in a dental clinic. Laboratory examinations did not show meaningful changes. He underwent computed tomography of the neck, thorax, and abdomen, which showed evidence of left collection affecting the retromandibular, submandibular, parapharyngeal, vascular, and mediastinal spaces, bilateral pleural effusion, right subphrenic collection and a small amount of liquids between intestinal loops. A cervical, thoracic, and abdominal surgical approach at the same surgery was indicated for odontogenic cervical abscess, descending necrotizing mediastinitis, and subphrenic abscess. The patient remained in the intensive care unit for three days, and he was discharged on the 22nd day after surgery with no drains and no tracheostomy. His outpatient discharge occurred after 6 months with no sequelae.ConclusionsAggressive surgical treatment associated with antibiotic therapy has been shown to be effective for improving the clinical course of cervical fasciitis. Despite the extension of the infection in our patient, a surgical approach of all infectious focus associated with a broad-spectrum antibiotic therapy led to a good clinical evolution and has significant implications for aggressive treatment.

New Measurement Method of Broadband Permittivity and Permeability of Non-Solid Materials in Small Quantity

Evaluation of permittivity (e) and permeability (μ) of magnetic/dielectric material in microwave band becomes more important with the rapid expansion of microwave technologies. Transmission/reflection line method is well known as a simultaneous measurement method of e and μ in the band. However in this method material under test (MUT) is limited to solid state. On the other hand, for measuring liquid material open ended coaxial probe method was proposed. The method is disadvantageous in terms of requiring deciliter volumes of MUT for approximating a semi-space filled by MUT. We propose a new measurement method with the aim of simultaneous measuring both of permittivity and permeability of not only solid material but also a small amount of liquid, powder, and gel state material. A plastic toroidal case was utilized to encapsulate non-solid state MUT and whole the case was evaluated by coaxial line method. In this study the cases were modeled using Acrylic 3-D printer (Stratasys, Objet 260 Connex). An example of the plastic case with a cap fabricated is shown in Fig. 1. Outer and inner diameter (7.00 and 3.00 mm) of the case was designed to fit to a coaxial sample holder (KEAD Inc., CSH2-APC7). The length of the case including a cap thickness measured by digital vernier caliper was 5.00 mm. In the same way, thickness of wall, bottom, and cap was 0.45, 0.50, and 0.50 mm, respectively. Accordingly the volume of MUT required for the case was about 70 microliters. The specimen which MUT was encapsulated was inserted to the coaxial sample holder and complex scattering (S) parameters from 1–10 GHz were taken using a vector network analyzer (Hewlett-Packard, HP 8720D). S-parameters whose reference planes were both upper and lower surface of the specimen were obtained by shifting reference planes of the measured S-parameters. After that we obtained S-parameters of MUT in numerical calculations mentioned below in order to take away unwanted plastic case portions. The specimen can be divided into three coaxial portions: Inner cylindrical wall, outer cylindrical wall, and middle core including MUT between their walls. From the viewpoint of electric circuit it corresponds to a series connection of the three two-port networks. Impedance (Z) parameters of the middle core were obtained using the relationship: Z-matrix of the specimen equals to the sum of their three Z-matrices. Z-matrix of the specimen was obtained by converting S-matrix of it by a reference impedance. Z-matrix of outer and inner wall was obtained from e and μ measured in advance using solid specimens of the plastic material and outer and inner diameters of their cylindrical walls. Z-matrix of the middle core was converted S-matrix again. The middle slender core can be divided into three coaxial portions: a part of cap, a part of bottom, and MUT. The core corresponds to a cascaded connection of the three two-port networks. Transfer (T) parameters of MUT were obtained using the relationship: T-matrix of the core equals to the product of their three T-matrices. T-matrix of the core was obtained by converting S-matrix of it. T-matrix of a part of bottom and cap was obtained from e and μ of the plastic material used and bottom and cap thickness. Finally e and μ of MUT were calculated from S-parameters of it using Nicolson-Ross-Wier algorithm [1, 2]. In this study, the air at the volume was measured as MUT in order to confirm a validity of the proposed method. The dependences of real and imaginary part of relative permittivity of air obtained by this method on frequency were shown in Fig. 2(a) and Fig. 2(b). Although the both values had a margin of error of plus or minus 10% a constant and nearly ideal relative permittivity of air was confirmed in the band measured from these figures. This result indicates that the proposed method is effective for measuring non-solid materials.

Spreading and drying impact on printed pattern accuracy due to phase separation of a colloidal ink

Drop-on-demand inkjet printing relies on the dispensing and precise positioning of very small amount of liquid on substrate before its transformation to a solid. Consequently, many steps are involved during inkjet printing process that must be understood to fabricate accurate patterns. In this work, multicomponent colloidal mixture spreading and drying is investigated. A systematic study has been performed to explain the impact of the jetting frequency, the drop spacing, and the substrate exposure to UV ozone on a colloidal silver ink behavior. It is demonstrated that phase separation between stabilizing agent and colloids can occur during the spreading step. This phenomenon is described and appears to be related to the colloidal nature of the ink. It is shown that it can have a negative impact on pattern accuracy and several routes are given to overcome these issues.

Autonomous self-pollination in the South African orchid Satyrium rupestre Schltr.

Autonomous self-pollination is widespread in orchids, but has not yet been reported for Satyrium, a genus in which floral variation is generally associated with attraction of and specialized pollination by a wide range of animals. Here I add evidence for autonomous self-pollination in the diminutive flowers of S. rupestre from the Cape Floristic Region. In recently opened flowers, pollinia of S. rupestre flowers have moved out of the anther sacs and, accompanied by reconfiguration of the caudicles, moved upwards to contact and rest on the stigma. Movement of the pollinia is associated with a narrowed central region of the rostellum, which results from tissue disintegration in flower buds; a process which does not occur in the animal-pollinated sister species S. ligulatum. Evidence of autonomous self-pollination in S. rupestre was observed both in fresh flowers in situ in two populations and in several herbarium specimens collected across the c. 400 km long species range, consistent with autonomous self-pollination as a species-wide trait. Tetrazolium staining tests indicated that more than 50% of seeds produced following self-pollination are viable. Although small amounts of liquid were detected in the spurs of S. rupestre flowers, scent emission rates and the number of massulae per pollinium are consistent with reduced reliance on animal pollinators. Future studies should focus on the extent to which the species relies on autonomous self-pollination for reproduction, to reveal whether it may serve as a mechanism of reproductive assurance in the pollinator-depauperate forest and cliff habitats of S. rupestre.

Collapse and runout of granular columns in pendular state

It is well known that even small amounts of liquid can strongly modify the mechanical behavior of granular packings in static and dynamic conditions. This experimental work, therefore, focuses on the collapse of columns of wet granular materials in the pendular wetting regime. Different from previous studies, where idealized spherical materials (glass beads) are typically used, here experiments on irregular wet calcium carbonate particles (coarse sand) were carried out and compared with glass sphere results. Particles of different sizes (in the range 0.8-5 mm) were mixed with water from 0% to 4% w/w and poured in a rectangular box. Flow was then triggered by removing a lateral wall of the box. The measured runout distances showed marked differences between the two types of materials which could not be explained only in terms of particle shape or capillary forces. Ring shear tests and 3D tomographic reconstructions of the liquid distribution in the materials highlighted the role of additional mechanisms related to liquid spreading at the particle surface, inter-particle friction, and contact lubrication.

FABRICATING THE MICROFLUIDIC CHIP WITH LENGTH-AND-DIAMETER RATIO OF CHANNEL AROUND 3000

Microfluidics is a device that accurately controls the motion of fluid flow with a very small amount of liquid. This field has been studied with many empirical applications in physics, chemistry, biochemistry, nanotechnology and biotechnology. Depending on particular application, the length-and-diameter ratio of channel is designed specifically in order to gain the highest efficiency for physical response and chemical reaction, etc. In this report, microfluidic chips, based on PDMS material, fabricated by soft lithography with the length-and-diameter ratio of channel 3000 times, have been fabricated for the research on biomedical orientation.Illustration of microfluidic chip with straight and spiral shape and the length-and-diameter ratio of channel around 3000.

Modeling of protein and salt redistribution during drying of a solution from a square cell

Background: Drying of biological fluids and saline biopolymer solutions is an actively researched topic, since the textures of the films remaining on the substrate after evaporation carry information about the state of the organism or biopolymer. Earlier, we have shown that the texture area and the amount of zigzag crystallization patterns depend on the structural state of the biopolymer. Models of flows and particle redistribution in a round sessile drop have been described by multiple authors, but in our experiments the solution completely fills a square cell to its walls, which results in different drying conditions and dynamics. Objectives: Conducting a numerical simulation of liquid evaporation and the corresponding redistribution of BSA and NaCl particles for a square 20×1×20 mm3 cell. Materials and methods: Liquid evaporation was simulated in the OpenFOAM continuous media modeling package using the interThermalPhaseChangeFoam module, and the redistribution of the particle concentrations (BSA, Na+ and Cl–) in the solution was simulated using the method of biased random walk on a discrete Cartesian lattice. Results: According to the obtained results, for most of the drying time, the flows in the liquid are from the corners to the center of the cell and from the diagonals to the walls of the cell, which leads to the accumulation of a significant fraction of the particles near the walls. When the liquid-air interface in the central part of the cell reaches the bottom, the surface tension forces quickly withdraw the solution to the cell walls, although a small amount of liquid can remain as a drop in the center. After complete drying, the majority of BSA and NaCl particles that did not settle at the cell walls were found to be concentrated at a distance of 1-3 mm from the cell walls, in the form of a rounded band. A small amount of BSA is also present in the central part of the cell, while the remainder of the salt is uniformly distributed over the entire area of the cell due to its greater diffusivity. Conclusions: Taking into account the experimental distributions of textures, these results support the hypotheses that textures are not formed in the absence of a biopolymer, and that zigzag patterns are formed in locations with high drying rate.

Coarse grain model for DEM simulation of dense and dynamic particle flow with liquid bridge forces

In many powder handling processes, liquid is added and dispersed into bulk dry powder. To study these systems, simulations of wet particles with small amounts of liquid are often performed by incorporating liquid bridge forces consisting of capillary and viscous forces into Discrete Element Method (DEM) (Sakai and Koshizuka, 2009). One of the existing challenges in DEM is the high computational cost to perform industrial scale simulations with large number of particles. One of the strategies often employed to reduce computational cost is by scaling up particle size, also known as the coarse grain method, which have been applied in several studies for dry cohesionless or dry cohesive particles. In the present work, the “direct force scaling” coarse grain model (Sakai and Koshizuka, 2009; Sakai et al., 2012) is applied for a dense and dynamic system of wet particles with liquid bridge forces. A general scaling criteria is proposed for different types of DEM related forces based on force balances on a control volume: l3 scaling for body forces and l2 scaling for interaction forces, where l is the scaling factor of the coarse grain particle. The coarse grain model is validated for wet particles in a vertical mixer in terms of the bulk flow and mixing behaviour. It is shown that the coarse grain model with l2 scaling of the liquid bridge forces can accurately predict the flow and mixing behaviour of the original wet particles.

The Ingestion of Fluorescent, Magnetic Nanoparticles for Determining Fluid-uptake Abilities in Insects.

Fluid-feeding insects ingest a variety of liquids, which are present in the environment as pools, films, or confined to small pores. Studies of liquid acquisition require assessing mouthpart structure and function relationships; however, fluid uptake mechanisms are historically inferred from observations of structural architecture, sometimes unaccompanied with experimental evidence. Here, we report a novel method for assessing fluid-uptake abilities with butterflies (Lepidoptera) and flies (Diptera) using small amounts of liquids. Insects are fed with a 20% sucrose solution mixed with fluorescent, magnetic nanoparticles from filter papers of specific pore sizes. The crop (internal structure used for storing fluids) is removed from the insect and placed on a confocal microscope. A magnet is waved by the crop to determine the presence of nanoparticles, which indicate if the insects are able to ingest fluids. This methodology is used to reveal a widespread feeding mechanism (capillary action and liquid bridge formation) that is potentially shared among Lepidoptera and Diptera when feeding from porous surfaces. In addition, this method can be used for studies of feeding mechanisms among a variety of fluid-feeding insects, including those important in disease transmission and biomimetics, and potentially other studies that involve nano- or micro-sized conduits where liquid transport requires verification.

The Ingestion of Fluorescent, Magnetic Nanoparticles for Determining Fluid-uptake Abilities in Insects

Fluid-feeding insects ingest a variety of liquids, which are present in the environment as pools, films, or confined to small pores. Studies of liquid acquisition require assessing mouthpart structure and function relationships; however, fluid uptake mechanisms are historically inferred from observations of structural architecture, sometimes unaccompanied with experimental evidence. Here, we report a novel method for assessing fluid-uptake abilities with butterflies (Lepidoptera) and flies (Diptera) using small amounts of liquids. Insects are fed with a 20% sucrose solution mixed with fluorescent, magnetic nanoparticles from filter papers of specific pore sizes. The crop (internal structure used for storing fluids) is removed from the insect and placed on a confocal microscope. A magnet is waved by the crop to determine the presence of nanoparticles, which indicate if the insects are able to ingest fluids. This methodology is used to reveal a widespread feeding mechanism (capillary action and liquid bridge formation) that is potentially shared among Lepidoptera and Diptera when feeding from porous surfaces. In addition, this method can be used for studies of feeding mechanisms among a variety of fluid-feeding insects, including those important in disease transmission and biomimetics, and potentially other studies that involve nano- or micro-sized conduits where liquid transport requires verification.

Magnetic resonance imaging of gas–solid fluidization with liquid bridging

Magnetic resonance imaging is used to generate snapshots of particle concentration and velocity fields in gas–solid fluidized beds into which small amounts of liquid are injected. Three regimes of bed behavior (stationary, channeling, and bubbling) are mapped based on superficial velocity and liquid loading. Images are analyzed to determine quantitatively the number of bubbles, the bubble diameter, bed height, and the distribution of particle speeds under different wetting conditions. The cohesion and dissipation provided by liquid bridges cause an increase in the minimum fluidization velocity and a decrease in the number of bubbles and fast particles in the bed. Changes in liquid loading alter hydrodynamics to a greater extent than changes in surface tension or viscosity. Keeping U/Umf at a constant value of 1.5 produced fairly similar hydrodynamics across different wetting conditions. The detailed results presented provide an important dataset for assessment of the validity of assumptions in computational models. © 2017 American Institute of Chemical Engineers AIChE J, 64: 2958–2971, 2018

Development of rectal self-emulsifying suspension of a moisture-labile water-soluble drug

Self-emulsifying drug delivery systems, commonly used for oral delivery of poorly soluble compounds, were used to formulate water soluble but moisture labile compounds for rectal application. The objective was to use the oily phase of the system to formulate a liquid, non-aqueous product while obtaining the advantages of self-emulsification, rapid contact with the rectal mucosa and rapid absorption post-administration. Ceftriaxone was used as a model drug and the human bile salt sodium chenodeoxycholate was used as an absorption enhancer. After preliminary screening of 23 excipients, based on their emulsification ability and emulsion fineness in binary and ternary mixtures, a full factorial design was used to screen different formulations of three preselected excipients. The optimal formulation contained 60% of excipients, namely Capryol 90, Kolliphor EL and Kolliphor PS20 in 4 : 6 : 6 ratio and 40% of a powder blend that included 500 mg of ceftriaxone. Characterization of the system showed that it complied with the requirements for rectal administration, in particular rapid emulsification in a small quantity of liquid. Rabbit bioavailability showed rapid absorption of ceftriaxone, achieving 128% bioavailability compared to powder control formulation. These results demonstrated the potential of self-emulsifying formulations for rectal administration of Class 3 BCS drugs.

Mitigation of whistling in vertical corrugated pipes by liquid addition

When a corrugated pipe is subject to a dry gas flow, high amplitude sound can be produced (so-called ‘whistling’). It was shown previously that liquid addition to corrugated pipe flow has the ability to reduce sound production. Small amounts of liquid are sufficient to mitigate whistling entirely. One of the mitigation mechanisms, cavity filling, is studied experimentally. Acoustic measurements are combined with a planar laser-induced fluorescence technique to measure the liquid accumulation in the cavities of a corrugated pipe. Using this technique, it is shown that the amount of filling of the cavities with liquid increases with increasing liquid injection rate and with reducing gas flow rate. The reduction in whistling amplitude caused by the liquid injection is closely related to the cavity filling. This indicates that the geometric alteration of the pipe wall, caused by the accumulation of liquid inside the cavities, is an important factor in the reduction in whistling amplitude.

Experimental investigation of dynamic characteristics of a rotary compressor and its air conditioner using R290 during warm startup

The object of this research was to experimentally study the dynamic characteristics of an R290 rotary compressor and its air conditioner during warm startup under a cooling condition. These dynamic characteristics included pressure changes in the cylinder and system, temperature changes in the compressor shell and system, the viscosity of refrigerant/oil mixture in the oil sump and liquid level of the oil sump. All experiments were carried out in the psychrometric rooms, in which the humidity and temperature kept constant. Experimental results showed that the minimum suction pressure (390kPa) during the warn startup was greater than that of the cold startup (145kPa). During the initial stage of warm startup process, a small amount of liquid was founded in the cylinder as the pressure increased rapidly to 1.7MPa in 1s. The viscosity and liquid level ranges in the compressor for the warm startup were smaller than that of the cold startup under the same cooling condition. This indicated that warm startup kept the R290 compressor a better-lubricated state and less oil was pumped into the system during the startup process.

Effect of liquid withdraw technique on the incidence of pneumothorax and tumor tissue amount of CT-guided cutting needle lung biopsy: An expanded retrospective study.

e20535 Background: CT-guided cutting needle lung biopsy is important for the diagnosis of lung cancer especially in the area of precision medicine. In ASCO 2015, we reported that “Liquid withdraw” technique (to inject small amount of liquid while withdraw of the needle) can prominently reduce incidence of pneumothorax when combined with co-axial technique in 38 cases. In this reported, we retrospectively studied 90 patients undergoing CT-guided cutting needle lung biopsy to investigate the role of this technique in reducing complications and promoting biopsy effectiveness. Methods: From Jan 1st, 2014 to Nov 30th, 2016, we retrospectively studied 92 CT-guided percutaneous lung biopsies using co-axial and liquid withdraw techniques in 90 patients. The pathologies and complications secondary to biopsy procedure were noted. Pneumothorax and bleeding was graded as mild (mild and very mild), moderate, and severe. Results: 88 cases were diagnosed out of 92 biopsies (95.7%), of which 60 cases were adenocarcinoma. Liquid withdraw technique assured adequate tissue for diagnosis and treatment planning of lung cancer. Among 71cases diagnosed as NSCLC, only 5 (7.0%) were diagnosed as NOS. Among 52 cases of adenocarcinoma who consented EGFR mutation test, only 1 case (1.9%) failed due to insufficient tissue. Among all the biopsies, when acquiring specimens 4-6 times per procedure, the incidence of pneumothorax was in 18 cases (19.6%), among which 13 cases (14.1%) were very mild pneumothorax (lung surface retraction of≤1 cm), mild and moderate pneumothorax accounted for just 4.3%. No severe pneumothorax occurred. 19 cases (20.7%) happened bleeding (18 cases were mild bleeding). No infection, tumor implantation or aeroembolism happened. Conclusions: Compared to lung biopsy without liquid withdraw, the incidence of pneumothorax was reduced from approximately 35% to 19.6%. The liquid withdraw technique also resulted in low rate of other complications and adequate tissue for diagnosis. Next, we are planning to conduct a prospective study to further evaluate the role of this technique in the precision diagnosis and treatment of lung cancer.

Liquid flexRIXS: A RIXS endstation for molecular systems at BESSY II

The liquid flexRIXS endstation is dedicated to resonant inelastic x-ray scattering experiments on liquid samples and gasses in the soft x-ray range. The liquids are injected into the chamber via a liquid jet system whereas gasses and also small amounts of liquids can be investigated using a liquid/gas flow cell. The MCP-based RIXS spectrometer allows for a resolving power of better than 1000.

Micturition Drive is Associated with Decreased Brain Response to Palatable Milkshake in the Human Anterior Insular Cortex

Introduction Most functional magnetic resonance imaging (fMRI) studies of taste deliver small quantities of liquids over roughly 45 min to repeatedly sample brain response to tastants. Within this time participants frequently report that their need to urinate increases.

A Portable 3D Printer System for the Diagnosis and Treatment of Multidrug-Resistant Bacteria

Summary Multidrug-resistant bacteria are a major threat to human health, but broad-spectrum antibiotics are losing efficacy. There is a need to screen a given drug against a bacterial infection outside of the laboratory. To address this need, we have designed and built an inexpensive and easy-to-use 3D-printer-based system that allows easily readable quantitative tests for the performance of antibacterial drugs. The platform creates a sterile diagnostic device by using 3D printing, and the device is filled automatically with growth medium, and then antibiotics are sprayed onto the medium by ink-jet technology. The sample for testing can be introduced via a fluid port, and the printer hot bed is used to incubate the device, allowing operation in the field. Combining advantages from various established tests of antibacterial performance, this allows the comparison of a specific antibiotics and bacteria. Also, this system can create and test several antibiotic formulations for therapeutic use, and we demonstrate this potential by investigating a mixture of pathogens that are only killed by a mixture of drugs.

CT characteristics of the sero-hepatic type of hepatic tuberculosis

Objective To study the CT features of the sero-hepatic type of hepatic tuberculosis. Methods This is a retrospective, multi-center and cross-sectional study. 17 patients with the sero-hepatic type of hepatic tuberculosis from the Yueqing People’s Hospital (n=5), Second Affiliated Hospital of Wenzhou Medical College (n=5), and Wenzhou People’s Hospital (n=7) were studied. All these patients were fasted for 8 h prior to CT scanning. They underwent enhanced after conventional CT breathless scanning with no abdominal pressure. Results The CT scans displayed 41 lesions in these 17 patients with the sero-hepatic type of hepatic tuberculosis, including a solitary lesion in 13 patients and multiple lesions in 4 patients. The diameter of the lesions varied from 0.8 to 4.7 cm, with a mean ± S. D. of 2.38±4.82 cm. The CT features showed a localized spindle-shaped focal lesion just underneath the liver capsule with resultant concave compression of the adjacent liver tissue (n=22), spotted calcifications in the center of the focal nodules (n=1); and aggregation of multiple low density nodular foci (n=19). Additional CT features included focal nodules surrounded by a small amount of liquid (n=15), compression of adjacent liver tissue (n=22), a small amount of ascites (n=8), and retroperitoneal lymph nodes enlargement (n=2). These nodules showed moderate (n=5) and slight enhancement in the arterial phase (n=36); moderate (n=32) and mild enhancement in the portal venous phase (n=9); and moderate (n=32) and mild enhancement in the parenchymal phase (n=9), respectively. The nodules showed ring-shaped (n=26), honeycomb or multiple ring-shaped enhancement (n=15). The enhanced ring-shaped wall thickness varied from 0.2 to 0.9 cm, with a thin wall (n=30) and a thick wall (n=11). The center of the focal nodule was a low density sac-shaped area, with no obvious contrast enhancement. The CT value was 21 to 39 hu. The infiltrative liver tissues which surrounded the focal nodules were shown as lamellar areas of obvious arterial enhancement, with equidensity in the portal vein phase and equilibrium phase. Conclusions CT showed characteristic features of the sero-hepatic type of hepatic tuberculosis. Clinical and laboratory findings could provide important supplementary information to make the diagnosis. Key words: Hepatic tuberculosis, sero-hepatic type; Tomography, X-ray computed