Article
Chemistry, Analytical
Woohyuk Kim, Beomseok Cha, Jessie S. Jeon, Jinsoo Park
Summary: We have developed an acoustofluidic method for dynamically controlling the chemical concentration (CC) within picoliterscale droplets at high-throughput production. The method involves rapidly mixing two fluids using acoustic streaming flow-induced micro-vortices, and precisely controlling the mixing index through modulation of the wave amplitude. We have demonstrated the applicability of this method for producing droplet libraries with tunable CCs, which is promising for various droplet microfluidic applications.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Analytical
Lindsay C. C. Elliott, Adam L. Pintar, Craig R. Copeland, Thomas B. Renegar, Ronald G. Dixson, B. Robert Ilic, R. Michael Verkouteren, Samuel M. Stavis
Summary: The study proposes a method that combines gravimetry and microscopy to measure the volume of microdroplets simultaneously and calibrate them accurately to the International System of Units (SI), achieving sub-picoliter level measurement consistency. The uncertainties and precision of the method match previous results while improving accuracy.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Analytical
Yan Zhang, Keyin Li, Yaoyao Zhao, Weihua Shi, Hrishikesh Iyer, Sungho Kim, Christopher Brenden, Jonathan V. Sweedler, Yurii Vlasov
Summary: We demonstrate a silicon-based integrated microfluidic platform for multiplexed analysis of neurochemicals in picoliter droplets via nanoelectrospray ionization (nESI)-mass spectrometry (MS). The developed system allows effective detection of multiple neurochemicals in low picoliter volumes, showing promising applications in monitoring a range of brain chemicals.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Analytical
Thomas Weber, Sundar Hengoju, Ashkan Samimi, Martin Roth, Miguel Tovar, Miriam A. Rosenbaum
Summary: Microfluidic emulsion-based droplet systems have the potential for inexpensive and high-throughput experimentation. However, selecting and amplifying single droplets of interest from a large number of other droplets is still a challenge. To overcome this limitation, a system is presented where droplets of interest are collected and positioned on agar surface or microtiter plate. Results show effective isolation of single droplets, allowing for further analysis and processing.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Physics, Multidisciplinary
Amir A. Pahlavan, Lisong Yang, Colin D. Bain, Howard A. Stone
Summary: The study reveals that small droplets under the dominance of surface tension forces at small scales may exhibit pancakelike flat shapes and relax back to a spherical-cap shape toward the end of their lifetime. These pancakelike droplets not only suppress the coffee-ring effect, but also lead to uniform deposition of suspended particles.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Mingcong Wen, Benjun Yao, Shun Yuan, Weina Zhang, Yao Zhang, Guowei Yang, Hongxiang Lei
Summary: In this study, an optical method for coalescence and splitting of femto-/pico-liter droplets in microreactors is proposed. The microdroplets (oil and water) are stably trapped and directionally transported using a scanning optical tweezing system, and optically controlled coalescence and splitting of the microdroplets are achieved. These microreactors combine the advantages of miniaturization and the multi-functions of microdroplets, as well as the precision, flexibility, and non-invasiveness of optical tweezers, showing great potential for applications in materials synthesis and biosensing.
Article
Nanoscience & Nanotechnology
Philipp Rosenberger, Ritika Dagar, Wenbin Zhang, Arijit Majumdar, Marcel Neuhaus, Matthias Ihme, Boris Bergues, Matthias F. Kling
Summary: Droplets provide a unique platform for investigating laser-induced surface chemistry. This study demonstrates the application of reaction nanoscopy technique to propanediol nanodroplets and reveals the sensitivity of the technique to droplet size, charge, and surface chemistry. The results show enhanced production of methyl cations from 1,2-PDO droplets compared to 1,3-PDO droplets, highlighting the role of surface alignment in chemical reactions on droplets. These findings open up opportunities for spatio-temporal observations of charge dynamics and surface reactions on droplets.
Article
Chemistry, Multidisciplinary
Weizhi Liu, Ruihua Zhang, Shanqing Huang, Xingrui Li, Wanling Liu, Jianhui Zhou, Lin Zhu, Yanling Song, Chaoyong Yang
Summary: Single-cell protein analysis allows for quantification of protein expression in individual cells, shedding light on cell-to-cell variation in heterogeneous biological systems. A microfluidic method has been developed to profile protein expression in individual cells using paired droplets, achieving high sensitivity and minimal protein loss. This platform can identify cell types and investigate heterogeneity within cell populations, establishing a foundation for parallel, sensitive, and integrated protein quantification at the single-cell level.
Article
Chemistry, Analytical
Hiroki Ashiba, Masato Yasuura, Takashi Fukuda, Ken Hatano, Makoto Fujimaki
Summary: Quick and sensitive virus detection methods have been developed using sub-picoliter microwells. The methods include the use of an aggregation-induced emission (AIE) reagent and enzymatic reaction supported with high-concentration immunomagnetic beads. The AIE reagent method achieved a detection limit of 3 x 10^5 copies/mL within 1 minute, while the high-concentration immunomagnetic beads method had a detection limit as low as 1 x 10^2 copies/mL.
ANALYTICA CHIMICA ACTA
(2022)
Article
Chemistry, Multidisciplinary
Praveen Kumar Saravanan, Dinesh Bhalothia, Guo-Heng Huang, Amisha Beniwal, Mingxing Cheng, Yu-Chieh Chao, Ming-Wei Lin, Po-Chun Chen, Tsan-Yao Chen
Summary: The catalytic conversion of CO2 into valuable commodities is important, and the reverse water-gas shift (RWGS) reaction plays a key role in this process. However, the CO2 methanation reaction limits the CO production yield, so a highly CO-selective catalyst is needed. In this study, a bimetallic nanocatalyst, CoPd, was developed and laser irradiation was used to optimize its catalytic activity and selectivity. The CoPd-10 nanocatalyst showed the highest CO production yield with improved selectivity, which was attributed to surface restructuring and formation of heteroatomic reaction sites.
Article
Energy & Fuels
Lihua Zhang, Shi Chen, Xingzhu Wang, Deng Wang, Yan Li, Qian Ai, Xiyu Sun, Jiabang Chen, Yang Li, Xiongzhuo Jiang, Shihe Yang, Baomin Xu
Summary: This study develops a heat-assisted inkjet-printing process for directly printing compact and uniform crystalline perovskite films on the planar PEDOT:PSS substrate under ambient conditions. By systematically studying the effects of precursor composition, printing temperature, solvent system, and printing parameters, along with revealing crystal growth models, the research provides constructive guidance for future studies on ambient inkjet-printed perovskite films and devices. Enhanced power conversion efficiency (PCE) of 16.6% is achieved for ambient printed PSC devices, offering a reliable and cost-effective approach for scalable fabrication of perovskite films with low material consumption.
Article
Chemistry, Analytical
Margarita Khariton, Conor J. McClune, Kara K. Brower, Sandy Klemm, Elizabeth S. Sattely, Polly M. Fordyce, Bo Wang
Summary: Microfluidic droplet assays enable single-cell PCR and sequencing analyses at unprecedented scales. Encapsulating cells within picoliter double emulsion allows sorting droplets with commercially available FACS machines, making it possible to isolate single cells based on phenotypes of interest. However, sorting DE droplets with standard cytometers requires small droplets that can pass FACS nozzles. Therefore, this study overcame limitations by using a plate-based RT-PCR assay to ameliorate the inhibition and demonstrated one-step RT-PCR from single cells in 20 pL DE droplets with fluorescence quantifiable via FACS.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Margarita Khariton, Conor J. McClune, Kara K. Brower, Sandy Klemm, Elizabeth S. Sattely, Polly M. Fordyce, Bo Wang
Summary: Microfluidic droplet assays enable single-cell PCR and sequencing analyses at unprecedented scales. However, sorting small droplets for FACS poses challenges for molecular biology. To overcome this, we used a plate-based RT-PCR assay and showed that heat lysis can alleviate inhibition for most cell lines, allowing RT-PCR to proceed in low-picoliter volumes.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Masanobu Sagisaka, Takumi Endo, Kazuki Fujita, Yasushi Umetsu, Suzuna Osaki, Tsuyoshi Narumi, Atsushi Yoshizawa, Azmi Mohamed, Frederic Guittard, Christopher Hill, Julian Eastoe
Summary: This study introduces new amphiphiles with double and triple hedgehog tails, showing their effectiveness in reducing surface tension at the critical micelle concentration. Interestingly, the surface layer density is found to be a key factor in promoting low surface tension, rather than the total number of carbon and silicon atoms in the hydrophobic tails. Additionally, the exchange of surfactant counterions from Na+ to Mg2+ is shown to significantly reduce the surface tension, making the surfactant comparable to typical fluorinated surfactants.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Zheng Zhong, Kaibao Sun, Guangyu Dan, Qingfei Luo, Xiaohong Joe Zhou
Summary: The purpose of this study was to demonstrate a reduced field of view (rFOV-SPEEDI) MRI pulse sequence for achieving sub-millisecond temporal resolution and decreasing scan times. The rFOV-SPEEDI method successfully captured fast-changing electric currents and the rapid opening and closing processes of the aortic valve with reduced FOVs, leading to a significant reduction in acquisition times compared to full FOV get-SPEEDI while maintaining spatial resolution. The results suggest that reducing the FOV can be an effective approach to accelerating scan times in MRI imaging.
MAGNETIC RESONANCE IN MEDICINE
(2021)
Letter
Anesthesiology
A. J. Shrimpton, J. M. Brown, T. M. Cook, A. E. Pickering
Article
Gastroenterology & Hepatology
Florence K. A. Gregson, Andrew J. Shrimpton, Fergus Hamilton, Tim M. Cook, Jonathan P. Reid, Anthony E. Pickering, Dimitri J. Pournaras, Bryan R. Bzdek, Jules Brown
Summary: Coughing during OGD is identified as the main source event for increased aerosol levels, highlighting the importance of appropriate precautions. Additionally, insertion and removal of the endoscope typically do not generate aerosols unless triggered by coughing.
Article
Anesthesiology
A. J. Shrimpton, J. M. Brown, F. K. A. Gregson, T. M. Cook, D. A. Scott, F. McGain, R. S. Humphries, R. S. Dhillon, J. P. Reid, F. Hamilton, B. R. Bzdek, A. E. Pickering
Summary: The study shows that manual facemask ventilation, even with an intentional leak, does not generate high levels of bioaerosol. Therefore, the authors argue that facemask ventilation should not be considered an aerosol-generating procedure.
Correction
Chemistry, Multidisciplinary
Shweta Narayan, Iaroslav Makhnenko, Davis B. Moravec, Brad G. Hauser, Andrew J. Dallas, Cari S. Dutcher
Article
Respiratory System
Fergus W. Hamilton, Florence K. A. Gregson, David T. Arnold, Sadiyah Sheikh, Kirsty Ward, Jules Brown, Ed Moran, Carrie White, Anna J. Morley, Bryan R. Bzdek, Jonathan P. Reid, Nicholas A. Maskell, James William Dodd
Summary: This study aimed to compare aerosol emission from HFNO and CPAP with breathing, speaking, and coughing. It found that in healthy volunteers, CPAP produced less aerosol than breathing, speaking, and coughing, while HFNO emissions mainly came from the machine and were unlikely to carry viral particles. Patients with COVID-19 coughed out more aerosol than volunteers.
Editorial Material
Respiratory System
Sadiyah Sheikh, Fergus W. Hamilton, George W. Nava, Florence K. A. Gregson, David T. Arnold, Colleen Riley, Jules Brown, Jonathan P. Reid, Bryan R. Bzdek, Nicholas A. Maskell, James William Dodd
Summary: Pulmonary function tests are essential for diagnosing respiratory diseases, but the production of potentially infectious aerosols during testing has been a concern. This study found that coughing generated the highest aerosol emission, while the use of viral filters and masks significantly reduced aerosol emission. Mitigation strategies such as these could help reduce the risk of transmission to staff during lung function testing.
Article
Biochemistry & Molecular Biology
Li Zhan, Joseph Sushil Rao, Nikhil Sethia, Michael Q. Slama, Zonghu Han, Diane Tobolt, Michael Etheridge, Quinn P. Peterson, Cari S. Dutcher, John C. Bischof, Erik B. Finger
Summary: By optimizing cryoprotectant agent composition and vitrification and rewarming methods, researchers have achieved high-quality cryopreservation of islets in mouse, porcine, human, and human stem cell-derived beta cell islets. The cryopreserved islets showed high viability and normal function, suggesting that cryopreservation could be used to supply needed islets for successful transplantation and diabetes cure.
Article
Mechanics
Emmanouil Chatzigiannakis, Yun Chen, Rana Bachnak, Cari S. Dutcher, Jan Vermant
Summary: The dynamics of thin films in water-in-oil emulsions were studied using a dynamic thin film balance, showing that external factors and variations in collision angle can affect coalescence time distributions. Difficulty extracting insights on the coalescence mechanism from these distributions was also discussed.
Article
Engineering, Chemical
Joshua Harrison, Brian Saccente-Kennedy, Christopher M. Orton, Lauren P. McCarthy, Justice Archer, Henry E. Symons, Alicja Szczepanska, Natalie A. Watson, William J. Browne, Benjamin Moseley, Keir E. J. Philip, James H. Hull, James D. Calder, Declan Costello, Pallav L. Shah, Ruth Epstein, Jonathan P. Reid, Bryan R. Bzdek
Summary: This study quantifies the generation of respiratory droplets (>20 μm) by a cohort of 76 adults and children using a water-sensitive paper droplet deposition approach. The study finds that oral articulation drives the production of droplets larger than 20 μm, while breathing generates virtually no droplets. The study also compares aerosol and droplet emissions for the same participants and reports the full size distribution of respiratory aerosols (0.5-1000 μm).
AEROSOL SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Chemical
Alicja Szczepanska, Joshua Harrison, Brian Saccente-Kennedy, Justice Archer, Natalie A. Watson, Christopher M. Orton, William J. Browne, Ruth Epstein, James D. Calder, Pallav L. Shah, Declan Costello, Bryan R. Bzdek, Jonathan P. Reid
Summary: Surgical face masks are effective in reducing the emission of respiratory particles and droplets, with varying filtration efficiency depending on the task. For particles with a diameter of 0.5-2 μm, filtration efficiency is high, while for particles larger than 4 μm, filtration efficiency is close to 100%. These results are important for preventing disease transmission through inhalation.
AEROSOL SCIENCE AND TECHNOLOGY
(2023)
Article
Anesthesiology
A. J. Shrimpton, V. Brown, J. Vassallo, J. P. Nolan, J. Soar, F. Hamilton, T. M. Cook, B. R. Bzdek, J. P. Reid, C. H. Makepeace, J. Deutsch, R. Ascione, J. M. Brown, J. R. Benger, A. E. Pickering
Summary: Cardiopulmonary resuscitation generates high concentrations of respiratory aerosol, suggesting the need for airborne transmission precautions in high-risk pathogen settings.
Article
Energy & Fuels
Rana Bachnak, Chinmayee Panigrahi, Davis B. Moravec, Brad G. Hauser, Andrew J. Dallas, Cari S. Dutcher
Summary: This study investigates the impact of surface interactions on droplet coalescence using microfluidic platforms. The results show that contact with fibers and other droplets affects the coalescence process, and droplets with multiple contacts have a higher likelihood of coalescence compared to two free droplets brought together. This research has important implications for essential industrial applications such as firefighting foams, oil remediation, and pharmaceutical preparation.
Article
Cell & Tissue Engineering
V. Hamilton, S. Sheikh, A. Szczepanska, N. Maskell, F. Hamilton, J. P. Reid, B. R. Bzdek, J. R. D. Murray
Summary: This study quantifies the aerosol exposure in orthopaedic surgeries and suggests additional precautions for diathermy and bone sawing to reduce exposure.
BONE & JOINT RESEARCH
(2023)
Article
Environmental Sciences
Alison Bain, Man Nin Chan, Bryan R. R. Bzdek
Summary: Organosulfates make up to 30% of the organic fraction of aerosol. Understanding their physical properties is crucial for predicting their impact on global climate, yet current knowledge is limited. This study measures the physical properties of aqueous solutions containing sodium methyl or ethyl sulfate and compares them with literature data for organosulfates, salts, and organics. The results show that organosulfates have intermediate physical properties between salts and short alkyl chain organics, except for water activity. This work emphasizes the importance of measuring and developing models for the physical properties of abundant atmospheric organosulfates to better understand aerosol's climate impact.
ENVIRONMENTAL SCIENCE-ATMOSPHERES
(2023)
Article
Biology
Justice Archer, Lauren P. McCarthy, Henry E. Symons, Natalie A. Watson, Christopher M. Orton, William J. Browne, Joshua Harrison, Benjamin Moseley, Keir E. J. Philip, James D. Calder, Pallav L. Shah, Bryan R. Bzdek, Declan Costello, Jonathan P. Reid
Summary: This study provides a robust assessment of the absolute particle number and mass exhalation rates from measurements of minute ventilation. The results indicate that children and adults generate similar amounts of aerosol when performing the same activity, and aerosol exhalation rate increases with increasing sound volume.
