MICROFLUIDIC APPROACHES FOR DISEASED CELL SEPARATION FROM BLOOD

Ph.DDOCTOR OF PHILOSOPH

Automatic Emergency Dust-Free solution on-board International Space Station with Bi-GRU (AED-ISS)

With a rising attention for the issue of PM2.5 or PM0.3, particulate matters have become not only a potential threat to both the environment and human, but also a harming existence to instruments onboard International Space Station (ISS). Our team is aiming to relate various concentration of particulate matters to magnetic fields, humidity, acceleration, temperature, pressure and CO2 concentration. Our goal is to establish an early warning system (EWS), which is able to forecast the levels of particulate matters and provides ample reaction time for astronauts to protect their instruments in some experiments or increase the accuracy of the measurements; In addition, the constructed model can be further developed into a prototype of a remote-sensing smoke alarm for applications related to fires. In this article, we will implement the Bi-GRU (Bidirectional Gated Recurrent Unit) algorithms that collect data for past 90 minutes and predict the levels of particulates which over 2.5 micrometer per 0.1 liter for the next 1 minute, which is classified as an early warningComment: 11 pages, 5 figures, and 1 tabl

Supercontinuum generation and carrier envelope offset frequency measurement in a tapered single-mode fiber

We report supercontinuum generation by launching femtosecond Yb fiber laser pulses into a tapered single-mode fiber of 3 um core diameter. A spectrum of more than one octave, from 550 to 1400 nm, has been obtained with an output power of 1.3 W at a repetition rate of 250 MHz, corresponding to a coupling efficiency of up to 60%. By using a typical f-2f interferometer, the carrier envelope offset frequency was measured and found to have a signal-to-noise ratio of nearly 30 dB.Comment: 10 pages, accepted by Appl Phys

Enhancing malaria diagnosis through microfluidic cell enrichment and magnetic resonance relaxometry detection

Despite significant advancements over the years, there remains an urgent need for low cost diagnostic approaches that allow for rapid, reliable and sensitive detection of malaria parasites in clinical samples. Our previous work has shown that magnetic resonance relaxometry (MRR) is a potentially highly sensitive tool for malaria diagnosis. A key challenge for making MRR based malaria diagnostics suitable for clinical testing is the fact that MRR baseline fluctuation exists between individuals, making it difficult to detect low level parasitemia. To overcome this problem, it is important to establish the MRR baseline of each individual while having the ability to reliably determine any changes that are caused by the infection of malaria parasite. Here we show that an approach that combines the use of microfluidic cell enrichment with a saponin lysis before MRR detection can overcome these challenges and provide the basis for a highly sensitive and reliable diagnostic approach of malaria parasites. Importantly, as little as 0.0005% of ring stage parasites can be detected reliably, making this ideally suited for the detection of malaria parasites in peripheral blood obtained from patients. The approaches used here are envisaged to provide a new malaria diagnosis solution in the near future.Singapore-MIT Alliance for Research and Technology Cente

Fabrication of multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors by using CF4 plasma treatment

Multianalyte CeO2 biosensors have been demonstrated to detect pH, glucose, and urine concentrations. To enhance the multianalyte sensing capability of these biosensors, CF4 plasma treatment was applied to create nanograin structures on the CeO2 membrane surface and thereby increase the contact surface area. Multiple material analyses indicated that crystallization or grainization caused by the incorporation of flourine atoms during plasma treatment might be related to the formation of the nanograins. Because of the changes in surface morphology and crystalline structures, the multianalyte sensing performance was considerably enhanced. Multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors exhibit potential for use in future biomedical sensing device applications

Cardiovascular Risk Factors and its Transition: An Ongoing Cohort Study in Chinese Kazakhs

Studies on the prevalence of risk factors and the incidence for cardiovascular diseases (CVDs) are limited in Kazakh population. By incorporating nomads, farmers, and urban residents, aged 30 years or older, in a cohort study, we investigated the characteristics of cardiovascular risk factors and their temporal trends that arose from the urbanization and subsequent changes in the lifestyle in a Kazakh population with 1668 participants. We used current guidelines and the monitoring trends and determinants in cardiovascular disease (MONICA) standard to define cardiovascular events. Kazakhs had a high prevalence rate of hypertension (45.3%), and this prevalence was much higher than the national average in China. Prevalence of two or more risk factors was highest among urban people and lowest among nomads. Urban residents have the highest prevalence of hypercholesterolemia and obesity compared with farmers and nomads. However, unlike other studies, our data indicate that young men had the highest prevalence of dyslipidemia, and it decreased significantly thereafter. Crude rates of incidence and mortality for acute cardiovascular events were 742 and 194 per 100,000 people, respectively; the standardized rates were 926 and 272 per 100,000 people, respectively. The findings from this study demonstrate the pervasive burden of cardiovascular risk factors and the related acute cardiovascular events in Kazakhs, particularly BP in Kazakh nomads

GRANULAR FLOW IN THE PRESENCE OF AN ELECTRIC FIELD

The granular flow in a vertical pipe in the presence of electric field E is studied. Depending upon its initial state and the applied field voltage the controlled flow rate remains in two phases, dilute flow or dense flow. For dilute flow, the electric field has no effect on the flow rate until V reaches a critical value Vj. At V = V 1} the flow rate drops abruptly and a transition of the particulate from dilute to dense flow occurs. For dense flow, the flow rate decreases monotonically with increasing V. A two-dimensional computer simulation has been done and the results agree qualitatively well with the experimental measurements

Esophageal Food Impaction: A Homemade Suction Tube Attached to Esophagogastroduodenoscopy for Food Bolus Removal

The most common esophageal foreign body in adults is impacted food bolus. Polypectomy snares, Dormia baskets, retrieval nets, rat-tooth forceps, alligator forceps or polyp graspers are usually used to remove it. Here, we report the case of a 78-year-old woman whose esophagogastroduodenoscopy (EGD) showed a firm goose liver impacted tightly in the lower esophagus; all of the above-mentioned retrieval instruments could not remove it. We used a homemade device by attaching a modified nasogastric tube to an EGD and successfully removed the goose liver by suction under endoscopic visualization. The method is very effective to remove firm and tightly impacted materials in a narrow lumen. When the usual retrieval instruments fail, a homemade suction tube attached to an EGD is an alternative

Agrobacterium rhizogenes-mediated transformation of Superroot-derived Lotus corniculatus plants: a valuable tool for functional genomics

<p>Abstract</p> <p>Background</p> <p>Transgenic approaches provide a powerful tool for gene function investigations in plants. However, some legumes are still recalcitrant to current transformation technologies, limiting the extent to which functional genomic studies can be performed on. <it>Superroo</it>t of <it>Lotus corniculatus </it>is a continuous root cloning system allowing direct somatic embryogenesis and mass regeneration of plants. Recently, a technique to obtain transgenic <it>L. corniculatus </it>plants from <it>Superroot</it>-derived leaves through <it>A. tumefaciens-</it>mediated transformation was described. However, transformation efficiency was low and it took about six months from gene transfer to PCR identification.</p> <p>Results</p> <p>In the present study, we developed an <it>A. rhizogenes</it>-mediated transformation of <it>Superroot</it>-derived <it>L. corniculatus </it>for gene function investigation, combining the efficient <it>A. rhizogenes</it>-mediated transformation and the rapid regeneration system of <it>Superroot</it>. The transformation system using <it>A. rhizogenes </it>K599 harbouring pGFPGUS<it>Plus </it>was improved by validating some parameters which may influence the transformation frequency. Using stem sections with one node as explants, a 2-day pre-culture of explants, infection with K599 at OD₆₀₀= 0.6, and co-cultivation on medium (pH 5.4) at 22°C for 2 days enhanced the transformation frequency significantly. As proof of concept, <it>Superroot</it>-derived <it>L. corniculatus </it>was transformed with a gene from wheat encoding an Na⁺/H⁺antiporter (<it>TaNHX2</it>) using the described system. Transgenic <it>Superroot </it>plants were obtained and had increased salt tolerance, as expected from the expression of <it>TaNHX2</it>.</p> <p>Conclusion</p> <p>A rapid and efficient tool for gene function investigation in <it>L. corniculatus </it>was developed, combining the simplicity and high efficiency of the <it>Superroot </it>regeneration system and the availability of <it>A. rhizogenes</it>-mediated transformation. This system was improved by validating some parameters influencing the transformation frequency, which could reach 92% based on GUS detection. The combination of the highly efficient transformation and the regeneration system of <it>Superroot </it>provides a valuable tool for functional genomics studies in <it>L. corniculatus</it>.</p