compact-lens-less-digital-holographic-microscope-for-mems-inspection

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and ...

Nanyang Technological University

Intravascular volume therapy is crucial in septic patients to improve tissue perfusion and maintain stable hemodynamics. Modified fluid gelatins (MFG) and medium weight hydroxyethyl starches (HES) are the most widely used synthetic colloids. Our aim in this study, performed in septic rats challenged by cecal ligation and puncture (CLP), was to investigate the effects of HES and MFG on pulmonary capillary leakage and to determine whether an antiinflammatory mechanism was involved.

Hydroxyethyl starch, but not modified fluid gelatin, affects inflammatory response in a rat model of polymicrobial sepsis with capillary leakage.

Feruloylated mono- and di-acylglycerols were synthesized in a two step reaction: ethyl ferulate was first transesterified with glycerol and then this was esterified with oleic acid. The yield of the combined feruloylated mono- and di-acylglycerols in the second reaction reached 96% when esterification of 0.3 g transesterification products with 2.22 g oleic acid was catalyzed with 0.25 g Candida antarctica lipase at 60 degrees C under a vaccum of 10 mmHg for 1.33 h.

A novel, two consecutive enzyme synthesis of feruloylated monoacyl- and diacyl-glycerols in a solvent-free system.

To report the experience with canalplasty during the operation of overlay tympanoplasty.

[Experience of canalplasty during the overlay tympanoplasty].

The oceans play a key role in climate regulation especially in part buffering (neutralising) the effects of increasing levels of greenhouse gases in the atmosphere and rising global temperatures. This chapter examines how the regulatory processes performed by the oceans alter as a response to climate change and assesses the extent to which positive feedbacks from the ocean may exacerbate climate change. There is clear evidence for rapid change in the oceans. As the main heat store for the world there has been an accelerating change in sea temperatures over the last few decades, which has contributed to rising sea-level. The oceans are also the main store of carbon dioxide (CO2), and are estimated to have taken up approximately 40% of anthropogenic-sourced CO2 from the atmosphere since the beginning of the industrial revolution. A proportion of the carbon uptake is exported via the four ocean 'carbon pumps' (Solubility, Biological, Continental Shelf and Carbonate Counter) to the deep ocean reservoir. Increases in sea temperature and changing planktonic systems and ocean currents may lead to a reduction in the uptake of CO2 by the ocean; some evidence suggests a suppression of parts of the marine carbon sink is already underway. While the oceans have buffered climate change through the uptake of CO2 produced by fossil fuel burning this has already had an impact on ocean chemistry through ocean acidification and will continue to do so. Feedbacks to climate change from acidification may result from expected impacts on marine organisms (especially corals and calcareous plankton), ecosystems and biogeochemical cycles. The polar regions of the world are showing the most rapid responses to climate change. As a result of a strong ice-ocean influence, small changes in temperature, salinity and ice cover may trigger large and sudden changes in regional climate with potential downstream feedbacks to the climate of the rest of the world. A warming Arctic Ocean may lead to further releases of the potent greenhouse gas methane from hydrates and permafrost. The Southern Ocean plays a critical role in driving, modifying and regulating global climate change via the carbon cycle and through its impact on adjacent Antarctica. The Antarctic Peninsula has shown some of the most rapid rises in atmospheric and oceanic temperature in the world, with an associated retreat of the majority of glaciers. Parts of the West Antarctic ice sheet are deflating rapidly, very likely due to a change in the flux of oceanic heat to the undersides of the floating ice shelves. The final section on modelling feedbacks from the ocean to climate change identifies limitations and priorities for model development and associated observations. Considering the importance of the oceans to climate change and our limited understanding of climate-related ocean processes, our ability to measure the changes that are taking place are conspicuously inadequate. The chapter highlights the need for a comprehensive, adequately funded and globally extensive ocean observing system to be implemented and sustained as a high priority. Unless feedbacks from the oceans to climate change are adequately included in climate change models, it is possible that the mitigation actions needed to stabilise CO2 and limit temperature rise over the next century will be underestimated.

Chapter 1. Impacts of the oceans on climate change.

The in vitro basic biological characteristics and directed differentiation potential towards cardiomyocytes of adult adipose-derived stem cells (ADSCs) induced by angiotensin II were both investigated. ADSCs were isolated from adult adipose tissue and cultured in vitro, and were subsequently induced into adipocytes, chondrocytes, and osteoblasts for assays of multipotential differentiation. The morphological characteristics of ADSCs were observed under an inverted microscope in bright field and phase-contrast ways and a confocal laser scanning microscopy. Moreover, the directional differentiation potential was observed by Oil Red, alkaline phosphatase, von Kossa, and toluidine blue stainings, respectively. The expressions of CD34, CD44, CD45, CD105, and HLA-DR were also detected via flow cytometry. Following to this, ADSCs were induced by angiotensin II and basic fibroblast growth factor for the purpose of directional differentiation towards cardiomyocyte-like cells, and the cells treated with 5-azacytidine were regarded as the control. The results showed that the isolated and cultured ADSCs presented a typical morphology of fusiform shape and also expressed CD44, CD105, but not CD34, CD45, and HLA-DR with assays of flow cytometry. The multi-differentiations to adipocytes, chondrocytes, and osteoblasts confirmed that the isolated cells maintained the stem characteristics generating from adipose tissues. After 4 weeks of induction by angiotensin II, the cells expressed myosin heavy chain, troponin I, and connexin43 by immunocytochemistry staining, but without beating of the cells. This current study indicated that ADSCs possessed the characteristics of mesenchymal stem cells and angiotensin II could induce ADSCs into cardiomyocyte-like cells.

In vitro culture, determination, and directed differentiation of adult adipose-derived stem cells towards cardiomyocyte-like cells induced by angiotensin II.

Thermal and magnetic field responsive biodegradable shape memory polymer nanocomposite was prepared with Fe3O4 nanoparticles and poly(L-lactides) (PLLA). The magnetic Fe3O4 nanoparticles with an average size of 9 nm were initially synthesized by co-precipitation method and then followed by surface modification using oleic acid. The TEM and SEM results show that the surface modified Fe3O4 nanoparticles can evenly disperse in chloroform and PLLA polymer matrix. The tensile test results show that the addition of Fe3O4 nanoparticles to a PLLA matrix greatly improved the elastic modulus, tensile strength, elongation at break, and the shape memory properties as well. Moreover, the shape recovery process of the nanocomposites driven by an alternating magnetic field was also observed. However, the shape recovery ratio and the recovery speed in an alternating magnetic field are lower than that occurred in 70 °C water. The lower shape recovery ratio and the recovery speed in an alternating magnetic field is attributed to the low frequency and strength of the magnetic field, which lead to small heat generated by Fe3O4 nanoparticles.

Biodegradable shape memory nanocomposites with thermal and magnetic field responsiveness.

Two polar vessels, Akademik Shokalskiy and Xuelong, were trapped by thick sea ice in the Antarctic coastal region just to the west of 144°E and between 66.5°S and 67°S in late December 2013. This event demonstrated the rapid establishment of extreme Antarctic sea ice conditions on synoptic time scales. The event was associated with cyclones that developed at lower latitudes. Near the event site, cyclone-enhanced strong southeasterly katabatic winds drove large westward drifts of ice floes. In addition, the cyclones also gave southward ice drift. The arrival and grounding of Iceberg B9B in Commonwealth Bay in March 2011 led to the growth of fast ice around it, forming a northward protruding barrier. This barrier blocked the westward ice drift and hence aided sea ice consolidation on its eastern side. Similar cyclone-induced events have occurred at this site in the past after the grounding of Iceberg B9B. Future events may be predictable on synoptic time scales, if cyclone-induced strong wind events can be predicted.

Cyclone-induced rapid creation of extreme Antarctic sea ice conditions.

A prominent feature of recent climatic change is the strong Arctic surface warming that is contemporaneous with broad cooling over much of Antarctica and the Southern Ocean. Longer global surface temperature observations suggest that this contrasting pole-to-pole change could be a manifestation of a multi-decadal interhemispheric or bipolar seesaw pattern, which is well correlated with the North Atlantic sea surface temperature variability, and thus generally hypothesized to originate from Atlantic meridional overturning circulation oscillations. Here, we show that there is an atmospheric origin for this seesaw pattern. The results indicate that the Southern Ocean surface cooling (warming) associated with the seesaw pattern is attributable to the strengthening (weakening) of the Southern Hemisphere westerlies, which can be traced to Northern Hemisphere and tropical tropospheric warming (cooling). Antarctic ozone depletion has been suggested to be an important driving force behind the recently observed increase in the Southern Hemisphere's summer westerly winds; our results imply that Northern Hemisphere and tropical warming may have played a triggering role at an stage earlier than the first detectable Antarctic ozone depletion, and enhanced Antarctic ozone depletion through decreasing the lower stratospheric temperature.

An atmospheric origin of the multi-decadal bipolar seesaw.

The electrically tunable lens (ETL) is a novel current-controlled adaptive optical component which can continuously tune its focus in a specific range via changing its surface curvature. To quantitatively characterize its tuning power, here we assume the ETL to be a pure phase object and present a novel calibration method to dynamically measure its wavefront by use of digital holographic microscopy (DHM). The least squares method is then used to fit the radius of curvature of the wavefront. The focal length is obtained by substituting the radius into the Zemax model of the ETL. The behavior curve between the focal length of the ETL and its driven current is drawn, and a quadratic mathematic model is set up to characterize it. To verify our model, an ETL and offset lens combination is proposed and applied to ETL-based transport of intensity equation (TIE) phase retrieval microscopy. The experimental result demonstrates the calibration works well in TIE phase retrieval in comparison with the phase measured by DHM.

Zhaomin Wang

School of Mechanical and Aerospace Engineering,
Center of Laser and Optical Engineering,
School of Mechanical and Aerospace Engineering, Center of Laser and Optical Engineering

Nanyang Technological University

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

Zhaomin Wang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}School of Mechanical and Aerospace Engineering,Center of Laser and Optical Engineering,School of Mechanical and Aerospace Engineering, Center of Laser and Optical Engineering

Nanyang Technological University

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

School of Mechanical and Aerospace Engineering,
Center of Laser and Optical Engineering,
School of Mechanical and Aerospace Engineering, Center of Laser and Optical Engineering