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1.
J Virol ; 98(3): e0127823, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38345384

RESUMO

Cytomegalovirus (CMV), a type of herpes virus, is the predominant cause of congenital anomalies due to intrauterine infections in humans. Adverse outcomes related to intrauterine infections with human cytomegalovirus (HCMV) vary widely, depending on factors such as fetal infection timing, infection route, and viral virulence. The precise mechanism underlying HCMV susceptibility remains unclear. In this study, we compared the susceptibility of neonatal human dermal fibroblast cells (NHDFCs) and human induced pluripotent stem cells (hiPSCs) derived from NHDFCs, which are genetically identical to HCMV, using immunostaining, microarray, in situ hybridization, quantitative PCR, and scanning electron microscopy. These cells were previously used to compare CMV susceptibility, but the underlying mechanisms were not fully elucidated. HCMV susceptibility of hiPSCs was significantly lower in the earliest phase. No shared gene ontologies were observed immediately post-infection between the two cell types using microarray analysis. Early-stage expression of HCMV antigens and the HCMV genome was minimal in immunostaining and in in situ hybridization in hiPSCs. This strongly suggests that HCMV does not readily bind to hiPSC surfaces. Scanning electron microscopy performed using the NanoSuit method confirmed the scarcity of HCMV particles on hiPSC surfaces. The zeta potential and charge mapping of the charged surface in NHDFCs and hiPSCs exhibited minimal differences when assessed using zeta potential analyzer and scanning ion conductance microscopy; however, the expression of heparan sulfate (HS) was significantly lower in hiPSCs compared with that in NHDFCs. Thus, HS expression could be a primary determinant of HCMV resistance in hiPSCs at the attachment level. IMPORTANCE: Numerous factors such as attachment, virus particle entry, transcription, and virus particle egress can affect viral susceptibility. Since 1984, pluripotent cells are known to be CMV resistant; however, the exact mechanism underlying this resistance remains elusive. Some researchers suggest inhibition in the initial phase of HCMV binding, while others have suggested the possibility of a sufficient amount of HCMV entering the cells to establish latency. This study demonstrates that HCMV particles rarely attach to the surfaces of hiPSCs. This is not due to limitations in the electrostatic interactions between the surface of hiPSCs and HCMV particles, but due to HS expression. Therefore, HS expression should be recognized as a key factor in determining the susceptibility of HCMV in congenital infection in vitro and in vivo. In the future, drugs targeting HS may become crucial for the treatment of congenital CMV infections. Thus, further research in this area is warranted.


Assuntos
Infecções por Citomegalovirus , Citomegalovirus , Heparitina Sulfato , Células-Tronco Pluripotentes Induzidas , Humanos , Recém-Nascido , Membrana Celular/química , Membrana Celular/metabolismo , Citomegalovirus/fisiologia , Heparitina Sulfato/análise , Heparitina Sulfato/metabolismo , Infecções por Herpesviridae , Células-Tronco Pluripotentes Induzidas/química , Células-Tronco Pluripotentes Induzidas/metabolismo , Fibroblastos/química , Fibroblastos/metabolismo , Fibroblastos/virologia , Pele/citologia
2.
Opt Express ; 31(25): 41726-41739, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38087564

RESUMO

In this study, we developed an in-process sintering method for laser-assisted electrophoretic deposition (LAEPD) using an additional laser to sinter Au particles and improve the Young's modulus of the microstructures fabricated using LAEPD. Thus, in addition to the laser (λ = 488 nm) that traps nanoparticles, another laser (λ = 785 nm) was installed to effectively absorb and sinter the deposited nanoparticles. Deposition was performed via LAEPD and laser sintering alternatively during fabrication. A Young's modulus of 28.2 GPa was achieved for the Au pillar fabricated with a sintering laser irradiation time of 1000 ms/cycle.

3.
Chromosome Res ; 29(1): 95-106, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33694044

RESUMO

Scanning probe microscopy (SPM) uses a probing tip which scans over a sample surface for obtaining information on the sample surface characteristics. Among various types of SPM, atomic force microscopy (AFM) has been widely applied to imaging of biological samples including chromosomes. Scanning ion conductance microscopy (SICM) has been also introduced for visualizing the surface structure of biological samples because it can obtain "contact-free" topographic images in liquid conditions by detecting ion current flow through a pipette opening. However, we recently noticed that the consistent imaging of chromosomes is difficult by SICM. In this paper, the behaviors of the ion current on the sample surfaces were precisely investigated for obtaining SICM images of isolated muntjac metaphase chromosomes more consistently than at present. The present study revealed that application of positive potential to the pipette electrode was acceptable for obtaining the topographic image of chromosomes, while application of negative potential failed in imaging. The approach curves were then studied for analyzing the relationship between the ion current and the tip sample distance when the pipette is approaching chromosomes. The current-voltage (I-V) curve further provided us the accurate interpretation of the ion current behavior during chromosome imaging. These data were further compared with those for SICM imaging of HeLa cells. Our findings indicated that chromosomes are electrically charged and the net charge is strongly negative in normal Dulbecco's phosphate buffered saline. We finally showed that the ion concentration of the bath electrolyte is important for imaging chromosomes by SICM.


Assuntos
Cromossomos , Microscopia , Células HeLa , Humanos , Metáfase
4.
Anal Chem ; 93(4): 2263-2272, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33400515

RESUMO

Direct extraction and ionization techniques using minute amounts of solvent can be employed for the rapid analysis of chemical components in a sample without any sample preparation steps. This type of approach is important for mass spectrometry imaging of samples with multiple chemical components that have different spatial distributions (i.e., biological tissues). To improve the spatial resolution of such imaging, it is necessary to reduce the solvent volume for extraction and deliver it to the sample surface. This report describes a feedback control system applied to tapping-mode scanning probe electrospray ionization. By combining the measurement technique of capillary probe vibration with the dynamic distance control system between the probe and the sample, the vibration amplitude of the probe is maintained while the probe scans over uneven samples. This method allows simultaneous high-resolution imaging of molecular distribution, surface topography, and amplitude/phase changes in the probe vibration. Such multimodal imaging is demonstrated on rhodamine B thin films in microwells and on a mouse brain tissue section. This technique can generally be applied to examine the multidimensional molecular distribution and the surface profiles of various objects.

5.
Nihon Shokakibyo Gakkai Zasshi ; 118(5): 455-461, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-33967130

RESUMO

Although amebiasis is usually asymptomatic, fulminant amebic colitis is associated with a high mortality rate. Here, we report the case of a patient with amebic colitis in which bowel perforation occurred despite treatment with metronidazole. A man in his 70s underwent steroid pulse therapy to treat serious acute hepatitis A. After corticosteroid therapy, he developed acute abdomen because of amebic colitis. We immediately administered metronidazole and his symptoms improved. After completing treatment, he developed colon perforation. Amebic colitis can progress to bowel perforation even after administering the appropriate medication, so this abdominal symptom requires careful attention.


Assuntos
Amebíase , Disenteria Amebiana , Perfuração Intestinal , Corticosteroides , Disenteria Amebiana/tratamento farmacológico , Humanos , Perfuração Intestinal/induzido quimicamente , Masculino , Metronidazol/efeitos adversos
6.
Semin Cell Dev Biol ; 73: 125-131, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28939037

RESUMO

Scanning ion conductance microscopy (SICM), which belongs to the family of scanning probe microscopy, regulates the tip-sample distance by monitoring the ion current through the use of an electrolyte-filled nanopipette as the probing tip. Thus, SICM enables "contact-free" imaging of cell surface topography in liquid conditions. In this paper, we applied hopping mode SICM for obtaining topographical images of convoluted tissue samples such as trachea and kidney in phosphate buffered saline. Some of the SICM images were compared with the images obtained by scanning electron microscopy (SEM) after drying the same samples. We showed that the imaging quality of hopping mode SICM was excellent enough for investigating the three-dimensional surface structure of the soft tissue samples. Thus, SICM is expected to be used for imaging a wide variety of cells and tissues - either fixed or alive- at high resolution under physiologically relevant liquid conditions.


Assuntos
Glomérulos Renais/citologia , Glomérulos Renais/ultraestrutura , Microscopia/métodos , Traqueia/citologia , Traqueia/ultraestrutura , Animais , Propriedades de Superfície
7.
Adv Funct Mater ; 30(28): 1910491, 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32684902

RESUMO

Many emerging applications in microscale engineering rely on the fabrication of 3D architectures in inorganic materials. Small-scale additive manufacturing (AM) aspires to provide flexible and facile access to these geometries. Yet, the synthesis of device-grade inorganic materials is still a key challenge toward the implementation of AM in microfabrication. Here, a comprehensive overview of the microstructural and mechanical properties of metals fabricated by most state-of-the-art AM methods that offer a spatial resolution ≤10 µm is presented. Standardized sets of samples are studied by cross-sectional electron microscopy, nanoindentation, and microcompression. It is shown that current microscale AM techniques synthesize metals with a wide range of microstructures and elastic and plastic properties, including materials of dense and crystalline microstructure with excellent mechanical properties that compare well to those of thin-film nanocrystalline materials. The large variation in materials' performance can be related to the individual microstructure, which in turn is coupled to the various physico-chemical principles exploited by the different printing methods. The study provides practical guidelines for users of small-scale additive methods and establishes a baseline for the future optimization of the properties of printed metallic objects-a significant step toward the potential establishment of AM techniques in microfabrication.

8.
Nano Lett ; 17(11): 7117-7124, 2017 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-29047282

RESUMO

Focusing on intracellular targets, we propose a new cell separation technique based on a nanoneedle array (NNA) device, which allows simultaneous insertion of multiple needles into multiple cells. The device is designed to target and lift ("fish") individual cells from a mixed population of cells on a substrate using an antibody-functionalized NNA. The mechanics underlying this approach were validated by force analysis using an atomic force microscope. Accurate high-throughput separation was achieved using one-to-one contacts between the nanoneedles and the cells by preparing a single-cell array in which the positions of the cells were aligned with 10,000 nanoneedles in the NNA. Cell-type-specific separation was realized by controlling the adhesion force so that the cells could be detached in cell-type-independent manner. Separation of nestin-expressing neural stem cells (NSCs) derived from human induced pluripotent stem cells (hiPSCs) was demonstrated using the proposed technology, and successful differentiation to neuronal cells was confirmed.


Assuntos
Anticorpos Imobilizados/química , Separação Celular/instrumentação , Nanoestruturas/química , Agulhas , Animais , Linhagem Celular , Desenho de Equipamento , Células HeLa , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células MCF-7 , Camundongos , Células NIH 3T3 , Nanoestruturas/ultraestrutura , Células-Tronco Neurais/citologia , Análise Serial de Tecidos/instrumentação
9.
Opt Express ; 22(23): 28109-17, 2014 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-25402051

RESUMO

We describe a novel fabrication method of three-dimensional (3D) microstructures using local electrophoresis deposition together with laser trapping. A liquid cell consisting of two-faced conductive substrates was filled with a colloidal solution of Au nanoparticles. The nanoparticles were trapped by a laser spot and positioned on the bottom substrate, then deposited onto the surface by the application of electrical voltage between the two substrates. By moving the liquid cell downward while maintaining the deposition, 3D microstructures were successfully fabricated. The smallest diameter of the fabricated pillar was 500 nm, almost the same as that of the Airy disc. The Young's modulus of the fabricated structure was 1.5 GPa.


Assuntos
Eletroforese/instrumentação , Lasers , Microtecnologia/métodos , Nanopartículas/química , Nanotecnologia/métodos , Desenho de Equipamento
10.
Rev Sci Instrum ; 94(7)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37466407

RESUMO

A high-speed imaging method for a scanning ion conductance microscope (SICM) based on a current source amplifier that compensates for unavoidable capacitance is proposed. The capacitance is generated on a side wall of a nanopipette in the principle of the SICM. The electrical response time is deteriorated due to the capacitance, and the probe overshoots the setpoint of the detection of the sample surface. A capacitance compensation circuit was installed in a feedback circuit of the current source amplifier. The proposed capacitance compensation method is useful because it can shorten the imaging time by only installing the compensation circuit in the ion current detection circuit of an existing SICM. The maximum approaching speeds with and without capacitance compensation were found to be 1050 and 450 µm/s, respectively. The approaching speed with capacitance compensation was 2.3 times faster than that without capacitance compensation. A topographic image of the test sample was successfully obtained at an approaching speed of 1050 µm/s. The images of microvillus dynamics of COS-7 cells were obtained at ∼23.4 s/frame as an application of the developed technology.

11.
Best Pract Res Clin Rheumatol ; 37(1): 101832, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-37248141

RESUMO

Ultrasound (US)-guided procedures have increasingly gained their role in the daily practice of rheumatology, owing to the growing evidence supporting their utility. The utilization of US guidance in procedures may enhance their accuracy, efficacy, and safety. This article presents a comprehensive review of the current evidence and practical knowledge pertaining to US-guided procedures in rheumatology, encompassing joint aspirations, injections, and other applications such as tendon sheath injections. We provide a detailed description of the US-guided procedure process and compare the in-plane and out-of-plane view methods, along with practical techniques based on existing evidence or our own expertise. For each joint, we summarize how to perform procedures with figures to facilitate a better understanding. Additionally, we introduce other applications of US-guided procedures for tendons, enthesis, bursae, and nerves as well as emerging therapies such as US-guided fascia hydrorelease. By utilizing these US techniques, rheumatologists can achieve the ability to manage a wider range of musculoskeletal conditions.


Assuntos
Doenças Musculoesqueléticas , Reumatologia , Humanos , Reumatologia/métodos , Ultrassonografia de Intervenção/métodos , Ultrassonografia , Doenças Musculoesqueléticas/terapia , Reumatologistas
12.
Mod Rheumatol Case Rep ; 7(1): 82-86, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36029470

RESUMO

Since its approval for the management of systemic lupus erythematosus (SLE), belimumab has been widely used. However, its pregnancy safety profile has been underinvestigated. We present the pregnancy outcomes of two cases of early placental exposure to belimumab and summarise the pregnancy outcomes in previous reports regarding placental exposure to belimumab. Case 1 describes a 27-year-old woman with an 18-year history of SLE and lupus nephritis class III. We introduced belimumab 19 months prior to conception to control her proteinuria and discontinued its use at 5 weeks and 5 days of gestation. Her lupus activity was stable throughout pregnancy, and at 37 weeks and 1 day of gestation, she delivered a healthy girl with no anomaly. At delivery, the girl was small for gestational age, but at the 1-year follow-up, there was no delay in her growth or any serious infection. Case 2 describes a 32-year-old woman with a 15-year history of SLE. We introduced belimumab 9 months prior to conception and discontinued its use at 7 weeks and 1 day of gestation. Although her lupus was well controlled without belimumab, a missed abortion occurred, which was possibly due to foetal factors. Although there is accumulating data on the safety of belimumab use during pregnancy, it seems necessary to cautiously use this medication in pregnant women, until further analyses are conducted.


Assuntos
Imunossupressores , Lúpus Eritematoso Sistêmico , Feminino , Humanos , Gravidez , Adulto , Imunossupressores/efeitos adversos , Placenta , Resultado do Tratamento , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Resultado da Gravidez
13.
Materials (Basel) ; 15(14)2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35888413

RESUMO

Carbon nanotubes (CNTs) are ultimately small structures, attractive for future nanoelectronics. CNT-bundles on Si nanostructures can offer an alternative pathway to build hybrid CMOS-compatible devices. To develop a simple method of using such CNT-bundles as transistor channels, we fabricated semiconductor single-walled CNT field-effect transistors using inkjet printing on a CMOS-compatible platform. We investigated a method of producing stable CNT solutions without surfactants, allowing for CNT debundling and dispersion. An inkjet-printing system disperses CNT-networks with ultimately low density (down to discrete CNT-bundles) in Al source-drain gaps of transistors. Despite the small number of networks and random positions, such CNT-bundles provide paths to the flow current. For enhanced controllability, we also demonstrate the manipulation of CNT-networks using an AFM technique.

14.
Front Plant Sci ; 13: 878059, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35812975

RESUMO

Genome editing in plants employing recombinant DNA often results in the incorporation of foreign DNA into the host genome. The direct delivery of genome-editing proteins into plant tissues is desired to prevent undesirable genetic alterations. However, in most currently available methods, the point of entry of the genome-editing proteins cannot be controlled and time-consuming processes are required to select the successfully transferred samples. To overcome these limitations, we considered a novel microneedle array (MNA)-based delivery system, in which the needles are horizontally aligned from the substrate surface, giving it a comb-like configuration. We aimed to deliver genome-editing proteins directly into the inner layers of leaf tissues; palisade, the spongy and subepidermal L2 layers of the shoot apical meristem (SAM) which include cells that can differentiate into germlines. The array with needles 2 µm wide and 60 µm long was effective in inserting into Arabidopsis thaliana leaves and Glycine max (L.) Merr. (soybeans) SAM without the needles buckling or breaking. The setup was initially tested for the delivery of Cre recombinase into the leaves of the reporter plant A. thaliana by quantifying the GUS (ß-glucuronidase) expression that occurred by the recombination of the loxP sites. We observed GUS expression at every insertion. Additionally, direct delivery of Cas9 ribonucleoprotein (RNP) targeting the PDS11/18 gene in soybean SAM showed an 11 bp deletion in the Cas9 RNP target site. Therefore, this method effectively delivered genome-editing proteins into plant tissues with precise control over the point of entry.

15.
J Electron Microsc (Tokyo) ; 60(6): 359-66, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22049270

RESUMO

We introduce a compact nanomanipulator that can be operated inside the sample chamber of a scanning electron microscope (SEM) for biological sample manipulation. The design of the nanomanipulator is based on that of an atomic force microscope (AFM). A self-sensitive cantilever is used to realize the compact body and thus it is possible to put a pair of the standalone AFM units on the sample stage in the SEM chamber. Using this system, we accomplished nanodissection of biological samples as well as AFM imaging under SEM observation. We then fabricated the surface of a rat renal glomerulus by scan-scratching and succeeded in making a small hole on the wall of a blood capillary. As a result, it was possible to observe the internal structure of the capillary, which had been hidden beneath the surface wall. Furthermore, using two AFM units on the sample stage of the SEM, we successfully dissected the lens fiber cells taken from a rat eye in a multi-probe operation using the two cantilevers. This system is expected to become a very useful tool for micro- and nanometer-scale anatomy and engineering applications.


Assuntos
Microscopia de Força Atômica/instrumentação , Microscopia Eletrônica de Varredura/métodos , Nanotecnologia/instrumentação , Animais , Dissecação/métodos , Glomérulos Renais/anatomia & histologia , Masculino , Microscopia de Força Atômica/métodos , Nanotecnologia/métodos , Ratos , Ratos Wistar , Sensibilidade e Especificidade
16.
Microscopy (Oxf) ; 70(5): 423-435, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-33644794

RESUMO

Scanning ion conductance microscopy (SICM) is useful for imaging soft and fragile biological samples in liquids because it probes the samples' surface topography by detecting ion currents under non-contact and force-free conditions. SICM acquires the surface topographical height by detecting the ion current reduction that occurs when an electrolyte-filled glass nanopipette approaches the sample surface. However, most biological materials have electrically charged surfaces in liquid environments, which sometimes affect the behavior of the ion currents detected by SICM and, especially, make topography measurements difficult. For measuring such charged samples, we propose a novel imaging method that uses a double-barrel nanopipette as an SICM probe. The ion current between the two apertures of the nanopipette desensitizes the surface charge effect on imaging. In this study, metaphase chromosomes of Indian muntjac were imaged by this technique because, owing to their strongly negatively charged surfaces in phosphate-buffered saline, it is difficult to obtain the topography of the chromosomes by the conventional SICM with a single-aperture nanopipette. Using the proposed method with a double-barrel nanopipette, the surfaces of the chromosomes were successfully measured, without any surface charge confounder. Since the detailed imaging of sample topography can be performed in physiological liquid conditions regardless of the sample charge, it is expected to be used for analyzing the high-order structure of chromosomes in relation to their dynamic changes in the cell division.


Assuntos
Cromossomos , Microscopia , Íons
17.
J Cardiol Cases ; 22(5): 249-252, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33133321

RESUMO

Coral reef aorta (CRA), a rare disease, is characterized by severe calcification of the juxta-renal and suprarenal aorta that grows into the lumen and leads to severe stenosis. A 70-year-old woman with refractory hypertension and lower limb claudication presented with hypertension and congestive heart failure. Treatment with vasodilators and diuresis led to oliguria and exacerbated kidney function, while her congestion remained. Abdominal computerized tomography showed a bulky, irregular localized supra-renal aortic calcification with stenosis. A peripheral artery ultrasound and angiography showed no occlusive lesions in the distal run-off vessels. Based on her medical history and the unique aspects of the localized calcified lesion, CRA was diagnosed. We suspected that the congestive heart failure, refractory hypertension, and renal failure resulted from the supra-renal aortic stenosis. Because she developed oliguria with diuretics and vasodilators, we performed an open graft replacement with a thoracoabdominal approach. The reddish-brown calcified mass came off easily and was very fragile. The postoperative course was uneventful, and her heart and renal failure were completely resolved. This is the first report showing the fragility of CRA. Considering its fragility, catheter treatment may need to be avoided to prevent distal embolism. .

18.
Arch Histol Cytol ; 72(4-5): 271-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-21471662

RESUMO

We developed a novel nano manipulator based on an atomic force microscope (AFM) that can be operated inside the sample chamber of a scanning electron microscope (SEM). This AFM manipulator is also coupled with a haptic device, and the nanometer-scale movement of the AFM cantilever can be scaled up to the millimeter-scale movement of the pen handle of the haptic device. Using this AFM manipulation system, we were able to observe the AFM cantilever and samples under the SEM and obtain topographical images of the AFM under the SEM. These AFM images contained quantitative height information of the sample that is difficult to obtain from SEM images. Our system was also useful for positioning the cantilever for accurate AFM manipulation because the manipulation scene could be directly observed in real time by SEM. Coupling of the AFM manipulator with the haptic device was also useful for manipulation in the SEM since the operator can move the AFM probe freely at any position on the sample surface while feeling the interaction force between the probe and the sample surface. We tested two types of cutting methods: simple cutting and vibration cutting. Our results showed that vibration cutting with probe oscillation is very useful for the dissection of biological samples which were dried for SEM observation. Thus, cultivated HeLa cells were successfully micro-dissected by vibration cutting, and the dissection process could be observed in real time in the SEM. This AFM manipulation system is expected to serve as a powerful tool for dissecting various biological samples at the micro and nanometer-scale under SEM observation.


Assuntos
Microscopia de Força Atômica/métodos , Microscopia Eletrônica de Varredura/métodos , Desenho de Equipamento , Células HeLa , Humanos , Nanotecnologia/instrumentação
20.
Mass Spectrom (Tokyo) ; 7(2): S0078, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31840014

RESUMO

Ambient sampling and ionization techniques based on direct liquid extraction and electrospray ionization are of great value for rapid analysis and mass spectrometry imaging. Scanning probe electrospray ionization (SPESI) enables the sampling and ionization of analyte molecules in a solid material using a liquid bridge and electrospray, respectively, from a single capillary probe. To further improve SPESI, it is essential to understand the dynamic behavior of nanoliter volumes of liquids during sampling and ionization. In this study, the dynamic formation and breakage of the liquid bridge and the subsequent electrospray ionization were investigated by measuring the displacement of the capillary probe using a new optical technique. Measurements revealed that both the time from the formation of the liquid bridge to its breakage and the time from the breakage of the liquid bridge to the detection of analyte ions were correlated with the physical properties of the solvent. It was also found that both of these times were positively correlated with the flow rate. These results will not only lead to the improvement of sampling and ionization efficiencies but also afford a greater understanding of the physicochemical properties of charged nanoliter volumes of liquids.

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