Glass Capillary Research Articles

A simple goniometer-compatible flow cell for serial synchrotron X-ray crystallography.

Serial femtosecond crystallography was initially developed for room-temperature X-ray diffraction studies of macromolecules at X-ray free electron lasers. When combined with tools that initiate biological reactions within microcrystals, time-resolved serial crystallography allows the study of structural changes that occur during an enzyme catalytic reaction. Serial synchrotron X-ray crystallography (SSX), which extends serial crystallography methods to synchrotron radiation sources, is expanding the scientific community using serial diffraction methods. This report presents a simple flow cell that can be used to deliver microcrystals across an X-ray beam during SSX studies. This device consists of an X-ray transparent glass capillary mounted on a goniometer-compatible 3D-printed support and is connected to a syringe pump via light-weight tubing. This flow cell is easily mounted and aligned, and it is disposable so can be rapidly replaced when blocked. This system was demonstrated by collecting SSX data at MAX IV Laboratory from microcrystals of the integral membrane protein cytochrome c oxidase from Thermus thermophilus, from which an X-ray structure was determined to 2.12 Å resolution. This simple SSX platform may help to lower entry barriers for non-expert users of SSX.

Densities, Viscosities, and Derived Properties for Binary Mixtures of Long-Chain Alcohols of 1-Hexanol + 1-Pentanol, + 2-Pentanol, + 2-Methyl-1-butanol, + 1-Heptanol, and + 1-Octanol from 288.15 to 338.15 K

Densities and viscosities for binary mixtures of long-chain alcohols are important to design transfer heat and mass equipment and to interpret the kind of interactions that occur in the studied blends. Current investigation indicated the measurements of densities and viscosities for liquid mixtures of 1-hexanol + 1-pentanol, + 2-pentanol, + 2-methyl-1-butanol, + 1-heptanol, and + 1-octanol from 288.15 to 338.15 K at atmospheric pressure and over the whole range of mole fractions. A vibrating tube densimeter and a glass capillary viscometer were used to measure the density and viscosity of the alcohol binary mixtures, respectively. Experimental measurements of the pure alcohols have been compared with the data reported in the literature using average absolute percentage deviation (AAPD) as a criterion. The obtained results demonstrated for density an AAPD of 0.023% and for viscosity an AAPD of 0.597%, which is a good agreement between the experimental findings and literature data. Excess molar volume and viscosity deviation present negative deviations for all the alcohol mixtures at the conditions considered in this research. These results indicate that the mixture suffers a volume contraction, which is caused by intermolecular forces of attraction between different alcohol molecules. The Redlich–Kister equation is used to fit the excess molar volume and viscosity deviation. Kinematic viscosities of the binary blends have been calculated through the Nava-Ríos et al. and McAllister equations.

Cavitation-induced microjets tuned by channels with alternating wettability patterns

A laser pulse focused near the closed end of a glass capillary partially filled with water creates a vapor bubble and an associated pressure wave. The pressure wave travels through the liquid toward the meniscus where it is reflected, creating a fast, focused microjet. In this study, we selectively coat the hydrophilic glass capillaries with hydrophobic strips along the capillary. The result after filling the capillary is a static meniscus which has a curvature markedly different than an unmodified capillary. This tilting asymmetry in the static meniscus alters the trajectory of the ensuing jets. The hydrophobic strips also influence the advancing contact line and receding contact line as the vapor bubble expands and collapses. We present thirteen different permutations of this system which includes three geometries and four coating schemes. The combination of geometry and coatings influences the jet breakup, the resulting drop size distribution, the trajectory of the jet tip, and the consistency of jet characteristics across trials. The inclusion of hydrophobic strips promotes jetting in line with the channel axis, with the most effective arrangement dependent on channel size.

High-throughput piezoelectric droplet dispenser driven by ultra-low voltage

Efficient and facile generation of tiny droplets is critical to many cutting-edge applications, such as flexible electronic skin, customized circuits, and micro-electro-mechanical systems. However, conventional piezoelectric inkjet printing techniques show more prominent problems of high driving voltage and relatively low printing frequency. Here, a novel principle for high-throughput droplet dispensing was proposed based on the resonance of the liquid column within the glass capillary. The mechanisms of this high-throughput piezoelectric droplet dispensing technique were studied both experimentally and theoretically. It is demonstrated experimentally that the resonance frequencies of different orders of the liquid column in the capillary fit perfectly with the theoretical value. It is further demonstrated that when the working frequency is close to the resonant frequency of piezoelectric ceramic, droplets can be ejected out by a driving voltage as low as 1 V. This ultra-low driving voltage and power consumption make this dispenser compatible with various digital transistor–transistor logic or complementary metal–oxide–semiconductor drive circuits without any power amplifier.

Formation of ibrutinib solvates: so similar, yet so different.

The transformation processes of non-solvated ibrutinib into a series of halogenated benzene solvates are explored in detail here. The transformation was studied in real time by X-ray powder diffraction in a glass capillary. Crystal structures of chlorobenzene, bromobenzene and iodobenzene solvates are isostructural, whereas the structure of fluorobenzene solvate is different. Four different mechanisms for transformation were discovered despite the similarity in the chemical nature of the solvents and crystal structures of the solvates formed. These mechanisms include direct transformations and transformations with either a crystalline or an amorphous intermediate phase. The binding preference of each solvate in the crystal structure of the solvates was examined in competitive slurry experiments and further confirmed by interaction strength calculations. Overall, the presented system and online X-ray powder diffraction measurement provide unique insights into the formation of solvates.

Development of a chub mackerel with less-aggressive fry stage by genome editing of arginine vasotocin receptor V1a2

Genome editing is a technology that can remarkably accelerate crop and animal breeding via artificial induction of desired traits with high accuracy. This study aimed to develop a chub mackerel variety with reduced aggression using an experimental system that enables efficient egg collection and genome editing. Sexual maturation and control of spawning season and time were technologically facilitated by controlling the photoperiod and water temperature of the rearing tank. In addition, appropriate low-temperature treatment conditions for delaying cleavage, shape of the glass capillary, and injection site were examined in detail in order to develop an efficient and robust microinjection system for the study. An arginine vasotocin receptor V1a2 (V1a2) knockout (KO) strain of chub mackerel was developed in order to reduce the frequency of cannibalistic behavior at the fry stage. Video data analysis using bioimage informatics quantified the frequency of aggressive behavior, indicating a significant 46% reduction (P = 0.0229) in the frequency of cannibalistic behavior than in wild type. Furthermore, in the V1a2 KO strain, the frequency of collisions with the wall and oxygen consumption also decreased. Overall, the manageable and calm phenotype reported here can potentially contribute to the development of a stable and sustainable marine product.

Directivity of photoacoustically generated ultrasound from a thin tube embedded in the soft phantom

Our previous study has revealed that acoustic resonances have non-negligible effects on photoacoustic signals for a liquid sample confined in a thin tube. In this paper, we present numerical and experimental studies on the effects of tube hardness on the directivity of the generated photoacoustic signal. A thin glass capillary and silicone tube of 1 mm in diameter were tested using a pulsed light of 637 nm wavelength. Black ink was confined in the glass capillary and silicone tube as a photoacoustic sample material. In the glass capillary, acoustic resonance modes in the glass capillary were efficiently excited, and clear directivity was observed in the generated photoacoustic signals. On the other hand, little resonance was stimulated in the silicon tube because of the acoustic impedance matching between the sample and surrounding media, which resulted in the weak confinement of acoustic waves. The results suggest a possibility of characterization of the physical properties of thin tubes.

A temperature sensor based on liquid crystal coated grapefruit microstructer fiber with core-offset splicing structure

A temperature sensor based on liquid crystal coated grapefruit microstructure fiber (GMF) with core-offset splicing structure is proposed and prepared. Both ends of the GMF are core-offset spliced with the single-mode fibers (SMF). The capillary glass tube is sleeved outside the GMF and filled with the liquid crystal. Due to the mismatch between the core mode fields of the input SMF and the GMF, a part of the light out of of the input SMF enters the core of the GMF, and the rest is coupled into the cladding of the GMF forming the cladding mode. The core-offset splicing structure forms the Mach-Zehnder interferometer and two beams interfere in the output SMF. Immersed in the liquid crystal solution, The interferometer generates the phase difference between the core mode and cladding modes of GMF with the change of external temperature. The temperature could be measured by detecting the change of the interference spectrum of the sensor. The experimental results show that the transmission spectrum appears red shift with the increase of temperature in 30 ∼ 90 °C, achieving the maximum temperature sensitivity of 202.26 pm/°C and good linearity. The sensor has the advantages of simple fabrication and high sensitivity, and has good applications in environment monitoring and industrial productions.

Sensing characteristics of a compact gourd-type MZ interferometer based on hollow-core fiber

A gourd-type hollow-core fiber (HCF) based Mach–Zehnder interferometer (MZI) is proposed, and its sensing properties are investigated and extended. The MZI splices both ends of a section of HCF with single-mode fibers and uses a fusion splicer to cone between the HCF-SMF fusion point and the HCF to form a gourd-shaped structure. The conical part and the collapsed region inside the HCF form the light splitting/combining part of the MZI. Studies have shown that the MZI has high refractive index (RI) sensitivity (up to 2705.7 nm/RIU) and low cross-sensitivity to temperature (1.21×10-5 °C/RIU), which is very suitable for biochemical sensing. Encapsulation of this structure using capillary glass tubes and glycerol can convert its high sensitivity to RI into a high sensitivity to temperature, increasing the temperature sensitivity (527.88 pm/ °C) by a factor of about 16. The temperature sensitivity and range of the sensor are adjustable. The MZI has the characteristics of easy preparation, low price, compact structure, and superior detecting performance, and has excellent application prospects in biochemical sensing and physical sensing such as RI and temperature.

Gas-phase dopant flow to modify nanoLC-MS and nanoESI protein charge

A miniature permeation device is used to add controlled amounts of gas-phase dopant to the air around two types of atmospheric pressure nanoflow electrospray source: a pulled glass capillary needle in a custom mount, and for the first time a commercial nano-liquid chromatography emitter in a commercial ion source housing. Intact proteins sprayed at 300 nL/min are charge-reduced by the addition of nitrogen doped with diethylamine, and the reaction is assisted by adjusting flow rate, positioning, and enclosure of the nanoflow emitter. Charge distribution is shifted to lower charge states with increasing amounts of dopant. The maximum signal of the most abundant charge state and the total signal abundance are increased to an extent dependent on the mass and isoelectric point of the protein.

Building a Hofmeister-like series for the maximum in density temperature of aqueous electrolyte solutions

The temperature of the maximum in density (TMD) at room pressure is experimentally evaluated for aqueous solutions of a set of halides containing F−, Cl−, Br−, I−, Li+, Na+, K+, Rb+, Cs+ and Mg2+ at a 1 m concentration. The measurements were performed by monitoring the density-temperature profiles and tracking the temperature-dependent position of the meniscus, in a capillary glass tube. Adding salts diminishes the TMD of the solutions with respect to pure water, being the magnitude of the change dependent on the nature of the electrolyte. The experimental values of the shift in the TMD can be split into individual ion contributions. From this information we were able to establish a rank of ions (i.e., a Hofmeister-like series) according to their efficiency in shifting down the TMD. The experimental results are also compared to simulation values obtained via Molecular Dynamics using the Madrid-2019 force field that assigns non-integer charges for the ions and is parametrized for the TIP4P/2005 water model. Finally, since the TMD is a fingerprint property of water, we will discuss the impact of ions on this maximum in relation with the way different ions modify the structure of water.

Electrical detection and analysis of exosomes by a glass capillary nanopore.

An exosome is a vesicle less than 200 nm in diameter released from a cell and works as a medium for cell-to-cell communication. It is suggested that compositions of encapsulated molecules in exosomes have diversity even from a same cell. Single-particle analysis will be insight into the understanding the diversity, but it is still challenging. Nanopore technology will have a potential to detect and to capture single exosomes because it can discriminate nanoparticle properties including size, shape, and surface properties such as the charge by observation of ionic current change through a nano-sized pore. Here, we proposed to use a glass capillary nanopore (φ∼200 nm) and attempt to capture milk exosomes. Exosomes used in this study were extracted from cow milk using a procedure proposed previously. The particle sizes were confirmed by dynamic light scattering (DLS). A glass capillary nanopore was prepared by a puller. We observed the pore diameter of the capillaries by a scanning electron microscope (SEM). In the nanopore experiments, a glass capillary was filled with and immersed in PBS solution to measure I-V curve for checking the pore conductance, and then it was replaced in the exosome solution to detect the exosomes. The size of extracted exosomes was confirmed by DLS, and it was consistent with that in a previous study (∼130 nm). The outer diameter of the glass nanopores ranged from about 100 to 500 nm determined by SEM observation. For channel current measurement, the current blockages were observed in the presence of exosomes that was depended on the polarity of the applying voltages. We are conducting identification of microRNA encapsulated in exosomes collected from the nanopore by RT-qPCR, and it will be discussed in San Diego.

Localized transverse flow measurement with dynamic light scattering line-scan OCT.

A novel decorrelation-based approach for measuring localized transverse flow velocity using line-scan (LS) optical coherence tomography (OCT) is proposed. The new approach allows for separation of the flow velocity component along the line-illumination direction of the imaging beam from other orthogonal velocity components, from particle diffusion motion, and from noise-induced distortion in the OCT signal's temporal autocorrelation. The new method was verified by imaging flow in a glass capillary and a microfluidic device and mapping the spatial distribution of the flow velocity within the beam's illumination plane. This method can be extended in the future to map the three-dimensional flow velocity fields for both ex-vivo and in-vivo applications.

Assessing rheometry for measuring the viscosity-average degree of polymerisation of cellulose in paper degradation studies

In paper degradation studies, the viscosity-average degree of polymerisation (DPv) is often used as a key indicator of the extent of degradation of cellulosic paper. DPv can be deduced from the viscosity of dilute paper solutions, as typically measured through glass capillary viscometry. The current study proposes an efficient, alternative method to evaluate DPv of cellulosic paper, which is based on rotational rheometry. The proposed methodology relies on the application of a shear flow in a thin film of cellulose solution to measure its dynamic viscosity, from which DPv can be subsequently derived in a straightforward fashion. Rheometry allows to measure the viscosity for a range of shear rates, which results in multiple DPv evaluations per sample, and thus in statistically representative data from an individual test. Further, rheometry typically requires considerably less paper mass per test than glass capillary viscometry, which makes the method attractive for paper degradation studies with limited sample availability. Also, rheometry measurements are less work-intensive than glass capillary viscometry measurements. The rheometry method has been applied to 4 hygrothermally aged cellulose paper samples and the unaged counterpart. The measurement results regarding the age-dependency of DPv and the number of cellulose chain scissions are compared to those obtained by glass capillary viscometry, showing a very good agreement. At a longer ageing time, both experimental methods reveal a non-linear decrease in time of DPv, and a non-linear increase in time of the number of cellulose chain scissions, which indicate that the cellulose ageing process is realistically captured. The agreement in measurement results further demonstrates that rheometry is an easy-to-use, accurate and efficient alternative for DPv measurements by glass capillary viscometry.

Electrokinetic Extraction of Doxorubicin from Biological Fluids by Polymer Inclusion Membrane Sampling Probe.

A polymer inclusion membrane (PIM) based sampling probe was developed for electrokinetic extraction of drugs from biological fluids. The probe was fabricated by dip-coating a nonconductive glass capillary tube in a homogeneous PIM solution for three cycles. The PIM solution comprised cellulose triacetate (CTA), 2-nitrophenyl octyl ether (NPOE), and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [EMIM][NTf2] in a ratio of 5:4:2. The developed probe electrokinetically extracted doxorubicin from human plasma, human serum, and dried blood spot (DBS). The practicability and reliability of the electrokinetic extraction were evaluated by LC-MS/MS to quantify the desorption of extracted doxorubicin. Under the optimized conditions, a quantification limit of 0.2-2 ng/mL was achieved for the three biological samples. The probe was further integrated into a portable battery-powered device for safe low-voltage (36 V) electrokinetic extraction. The developed technique is envisioned to provide a more efficient analytical workflow in the laboratory.

Capillary rise kinetics of 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMI.BF[formula omitted]) in a single glass tube: Experiment and modeling

Ionic liquids are materials composed purely of cations and anions which melt at or below 100 ∘C. For applications involving wetting of a solid surface by an ionic liquid or the flow of ionic liquid through capillaries, one must know the wetting properties of the ionic liquid/solid pair, such as the contact angle (θ). Herein, the use of a (numerical) theoretical model of capillary rise kinetics for describing the experimental data of meniscus height versus time for a particular ionic liquid (BMI.BF4) rising in a glass capillary tube is reported, assessing also the suitability of estimating the ionic liquid/glass contact angle (θ) from the fitting procedure involved. Capillary rise experiments were conducted in glass capillaries with 1 mm internal diameter and digital images from the corresponding videos (obtained with an smartphone high-resolution camera and a LED light box) were semi-automatically processed/analyzed using an algorithm (script) specifically developed for such purpose. A relatively good agreement between the experimental data and the theoretical predictions was found for the ionic liquid (BMI.BF4) studied, in particular with respect to the shape of the height versus time curve. From fitting the theoretical model to the experimental data, a value of 43.7±6.4∘ was obtained for the contact angle (θ) of BMI.BF4 in glass at a temperature of 23.7±0.4∘C. The results obtained validated the utilized methodology for determining the contact angle of ionic liquids in (transparent) solid surfaces and also showed its adequacy for studying the kinetics of capillary rise of such liquids in small vertical capillaries.

Electric field driven self-assembly of dissolved graphene foam particles in a capillary

The ability to self-organize particles under the influence of an external excitation (magnetic field, electric field, temperature, light or crossed effect) is one of the most fundamental aspects of science, which can be directly transferred to practical applications. Magneto- or electro- rheological fluids are an example of using such phenomena. The most important challenge is to reduce the energy required to induce self-assembly in larger structures from fractured parts. In this paper the self-construction ability of graphene microparticles is presented. The main observation regarding the self-assembly of graphene foam in a thin glass capillary into a single chain in methanol upon applied DC electric field is reported. The mechanism of self-ordering of molecules is discussed in terms of charge separation in semi-conducting graphene particles upon an applied DC electric field.Additionally, in order to prepare thin coatings with fixed self-assembled graphene structures inside, silica hydrolysate was applied.

Determination of amphetamines in human hair by flash evaporation-gas chromatography/mass spectrometry combined with micro-reaction device

A sensitive and novel method for the determination of methamphetamine (MAMP), 3,4-methylenedioxymethamphetamine (MDMA) and their metabolites amphetamine (AMP), 3,4-methylenedioxyamphetamine (MDA) in human hair was established by the employment of flash evaporation-gas chromatography/mass spectrometry (FE-GC/MS) combined with micro-reaction device. 0.30 mg human hair after cutting was put into a sealed glass capillary and heated at 270 °C in a pyrolyzer for 0.5 min. MAMP, AMP, MDMA and MDA evaporated from the hair were converted into their corresponding trifluoroacetylation product in a 60 °C water bath for 30 min with the acetylation by 2 μL trifluoroacetic anhydride (TFAH). Thus, amphetamines (AMPs) in human hair were separated and detected by GC/MS in SIM mode. The obtained calibration curves showed good linearity with the concentrations of MAMP, MDMA and MDA at 1–100 ng/mg, and AMP at 2–100 ng/mg. The linear correlation coefficients (r) were all larger than 0.996. Limits of detection for MAMP, AMP, MDMA and MDA were 0.67, 0.07, 0.17 and 0.07 ng/mg respectively. Limits of quantification for MAMP, AMP, MDMA and MDA were 2.00, 0.20, 0.50 and 0.20 ng/mg respectively. The precision over a range of 0.63–9.98 % were obtained with the recoveries of 92.7–115.2 % for AMPs. Five positive hair samples, three suspicious hair samples and two negative hair samples were successfully analyzed. The results of FE-GC/MS with micro-reaction device were comparable with those found by the referenced method. It was demonstrated that the developed method had potential applications for the analysis of AMPs in hair.

A micro sample pretreatment technique combined with ion chromatography and its application in the determination of polyvinyl chloride

A method for the determination of polyvinyl chloride was developed by the use of a micro sample pretreatment technique combined with ion chromatography. Polyvinyl chloride sample was placed in a sealed glass capillary containing 10 μL deionized water. As a micro pyrolysis reactor, the sealed glass capillary was maintained at 300 °C for 2 min in an oven. Under the above temperature, polyvinyl chloride was pyrolyzed rapidly and released hydrogen chloride, which was easily absorbed by deionized water. Subsequently, the absorption liquid was transferred to a volumetric flask and diluted to 10 mL. Ion chromatography was utilized to detect the content of chloride ion in the diluted absorption liquid for the quantification of polyvinyl chloride in samples. Good linear correlation coefficient (r = 0.9999) was obtained over a range of 0.02–2.00 mg polyvinyl chloride. Appropriate precision with the relative standard deviation below 16.4% and good recoveries between 86.0 and 119.4% were achieved in this work. The limits of detection and quantification were 0.004 mg and 0.012 mg for polyvinyl chloride respectively. The contents of polyvinyl chloride in real samples determined by the micro sample pretreatment technique were consistent with the results obtained by the referenced oxygen flask combustion method. It proved that the proposed method is simple, rapid and accurate for the determination of polyvinyl chloride in real samples.

Quasi-continuous infrared matrix-assisted laser desorption electrospray ionization source coupled to a quadrupole time-of-flight mass spectrometer for direct analysis from well plates.

High-throughput screening (HTS) is a technique mostly used by pharmaceutical companies to rapidly screen multiple libraries of compounds to find drug hits with biological or pharmaceutical activity. Mass spectrometry (MS) has become a popular option for HTS given that it can simultaneously resolve hundreds to thousands of compounds without additional chemical derivatization. For this application, it is convenient to do direct analysis from well plates. Herein, we present the development of an infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source coupled directly to an Agilent 6545 for direct analysis from well plates. The source is coupled to a quadrupole time-of-flight (Q-TOF) mass spectrometer to take advantage of the high acquisition rates without sacrificing resolving power as required with Orbitrap or Fourier-transform ion cyclotron resonance (FTICR) instruments. The laser used for this source operates at 100 Hz, firing 1 pulse-per-burst, and delivers around 0.7 mJ per pulse. Continuously firing this laser for an extended duration makes it a quasi-continuous ionization source. Additionally, a metal capillary was constructed to extend the inlet of the mass spectrometer, increase desolvation of electrospray charged droplets, improve ion transmission, and increase sensitivity. Its efficiency was compared with the conventional dielectric glass capillary by measured signal and demonstrated that the metal capillary increased ionization efficiency due to its more uniformly distributed temperature gradient. Finally, we present the functionality of the source by analyzing tune mix directly from well plates. This source is a proof of concept for HTS applications using IR-MALDESI coupled to a different MS platform.