A microfluidic droplet array demonstrating high-throughput screening in individual lipid-producing microalgae.

Microalgae are a group of photoautotrophic microorganisms which could use carbon dioxide for autosynthesis. They have been envisioned as one of the most prospective feedstock for renewable oil. However, great endeavors will still be needed to increase their economic feasibility. The screening of competitive species and suitable culture conditions are such issues. To greatly accelerate these rather laborious steps and also improve their experimental lump-sum-manner, we developed a microfluidic droplet-based 2 × 103 resolution "identification card", which allowed high throughput real-time monitoring of individual algae among population. A novel fluid-blocking-based droplet generating and trapping performance were integrated in the platform which made it excellent in operational simplicity, rapidity and stability and full of the potentials in single-cell-isolation/screening. The developed platform was successfully used to screen three unicellular algae, namely, Isochrysis zhanjiangensis, Platymonas subcordiformis and Platymonas helgolandica var. tsingtaoensis. In situ bioassays of the lipid accumulation and cell proliferation at single cell level for interspecies comparison were possible. Furthermore, lipid-producing inhomogeneity was demonstrated among cells in the same specie and batch. Nitrogen stress condition can be identified that induce positive-skewed frequency distribution of lipid content, even among individual inhomogeneous cells over the typically used culture condition.

Instrumentation-Compact Digital Microfluidic Reaction Interface-Extended Loop-Mediated Isothermal Amplification for Sample-to-Answer Testing of Vibrio parahaemolyticus.

Vibrio parahaemolyticus is usually spread via consumption of contaminated seafood and causes vibriosis. By combination of digital microfluidic (DMF) and loop-mediated isothermal amplification (LAMP), we provided an automated instrumentation-compact DMF-LAMP device for sample-to-answer detection of V. parahaemolyticus. For the first time, how much the proper mixing might facilitate the DMF-LAMP process is explored. The results illustrated that increasing the number of flow configurations and decreasing the fluid-reversibility will extend the interfacial surface available for diffusion-based mass transfer within a droplet microreactor, thus contributing to the overall amplification reaction rate. Noticeably, the DMF-LAMP amplification plateau time is shortened by proper mixing, from 60 min in static mixing and traditional bulk LAMP to 30 min in 2-electrode mixing and 15 min in 3-electrode mixing. The device achieved much higher detection sensitivity (two copies per reaction) than previously reported devices. V. parahaemolyticus from spiked shrimps is detected by Q-tip sampling associated with 3-electrode mixing DMF-LAMPs. The detectable signal occurs within only 3 min at a higher concentration and, at most, is delayed to 18 min, with a detection limit of <0.23 × 103 CFU/g. Thus, the developed DMF-LAMP device demonstrates potential for being used as a sample-to-answer system with a quick analysis time, high sensitivity, and sample-to-answer format.

A three-dimensional pinwheel-shaped paper-based microfluidic analytical device for fluorescence detection of multiple heavy metals in coastal waters by rational device design.

Here, we present the rational design of a pinwheel-shaped three-dimensional microfluidic paper-based analytical device (3D-µPAD) for specific, sensitive and multiplexed detection of heavy metals in coastal waters. A more homogeneous permeation of fluids along the chip than common design, even under unskilled performance, has been achieved by the elaborate chip design of the hydrostatic balancing inlet port and uniformly stressed reversible sealing. With the combination of ion imprinted polymer grafted CdTe quantum-dots and fluid accumulation pad, 4 metals (Cu2+, Cd2+, Pb2+, and Hg2+) in 1 analysis and 25-fold enrichment for each metal can be simultaneously performed within 20 min, with detection limits of 0.007-0.015 µg/L. It has the ability to selectively recognize these 4 metals in mixtures and immunizing to interferences from components found in coastal waters, which provided results that were in agreement with values gained from atomic absorption. The inexpensive and portable nature as well as the highly sensitive and flexible performance of the new developed 3D-µPAD could make it attractive as an on-site testing approach for marine environmental monitoring.

The predictors and prognosis for unexpected reocclusion after mechanical thrombectomy: a meta-analysis.

BACKGROUND: Mechanical thrombectomy (MT) is the cornerstone for treating acute ischemic stroke (AIS) in emergency cases. However, 3-9% of patients display reocclusion in the recanalized vessels within 24 hours after performing MT. This meta-analysis aimed to further identify the predictors and prognosis of unexpected reocclusion after MT. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, we searched several literature databases, including PubMed, Embase, and Cochrane, for publications related to the subject term "thrombectomy" that were published prior to March 2020. Pooled analysis was performed with the fixed-effects model using the Mantel-Haenszel method if the heterogeneity was expected to be available (I2≤50%). Otherwise, the random-effects model computed by the DerSimonian-Laird method was used (I2>50%). R software (http://www.r-project.org) was used for analysis in this study. RESULTS: A total of five articles comprising 1,883 patients (126 patients with reocclusion, 1,757 patients without reocclusion) who were confirmed to have AIS and who underwent emergency MT were finally included in this study. The pooled analysis (reocclusion versus non-reocclusion) showed that atrial fibrillation [odds ratio (OR), 0.36; 95% confidence interval (CI), 0.20-0.63], cardiogenic embolism (OR, 0.35; 95% CI, 0.20-0.63), long-term statin use (OR, 0.39; 95% CI, 0.21-0.75), long-term antiplatelet use (OR, 0.53; 95% CI, 0.31-0.92), and target occlusion at middle cerebral artery-M1 (MCA-M1) (OR, 0.39; 95% CI, 0.19-0.77) might prevent reocclusion and longer onset-to-reperfusion time (mean difference, 66.51; 95% CI, 36.66-96.35) might promote reocclusion after MT performance. Furthermore, the clinical outcomes including early neurological deterioration (OR, 4.87; 95% CI, 2.08-11.40), 90-day modified Rankin Scale score ≤2 (OR, 0.28; 95% CI, 0.18-0.45), and 90-day death rate (OR, 1.85; 95% CI, 1.04-3.29) were also associated with reocclusion after MT performance. CONCLUSIONS: Atrial fibrillation, cardiogenic embolism, long-term statin use, long-term antiplatelet use, and target occlusion at MCA-M1 might prevent reocclusion, and longer onset-to-reperfusion time seemed to promote reocclusion after MT. Reocclusion after MT results in a high risk of poor prognosis.

Post-thrombolysis hemorrhage in a patient with hypothyroidism and acute ischemic stroke: Case report.

Thrombolytic treatment with intravenous recombinant tissue plasminogen activator (rtPA) is an effective treatment for acute ischemic stroke. However, its effectiveness and risks in patients with hypothyroidism have not been reported. Here, we report the case of hemorrhagic transformation after intravenous rtPA thrombolysis treatment in a patient with acute ischemic stroke and hypothyroidism. An apparent edema formed around the hematoma and progressively worsened. He also developed lung infection, electrolyte imbalance, and abnormal liver and kidney functions, and eventually died within 1 month of symptom onset. Thus, our observations suggest that caution should be exercised for the administration of intravenous rtPA thrombolysis to patients with hypothyroidism.