成人VR视频

Description
Millimetric liquid droplet generation is important in a wide range of engineering scenarios. Successful generation requires that prescribed volumes can be dispensed repeatedly. Further, upon generation successive droplets should follow a well-defined trajectory and have minimal oscillations in volume. Currently employed droplet generating techniques do not address all of the desirable characteristics previously mentioned. A novel apparatus has been developed in our lab that successfully fulfills these requirements, as described in a recent journal article. A high level of droplet volume accuracy and precision is achieved by the use of a tee-junction. A desired volume of water is injected via a syringe pump, then pushed vertically downward with air pressure. Erratic droplet trajectories and oscillations are caused by adhesive solid-liquid forces at the generating tip. A superhydrophobic PTFE tip was engineered using femtosecond laser micromachining techniques. The highly fibrous microstructure left on the surface traps air beneath the liquid and thus a very small area fraction of solid is in contact with the liquid. Liquids with surface tensions lower than that of water do not yield the air trapping effect on superhydrophobic surfaces. Instead, the liquid-solid contact line moves such that the entire morphology becomes wetted. To reduce solid-liquid contact for low surface tension liquids, re-entrant structures must be ablated, whereby the contact line is pinned. We have developed methods to micromachine these structures in our lab onto flat PTFE plates. Imparting these structures onto the generating tip will allow for the production of droplets over a wide range of surface tensions..

Tasks:
(1) Replication of re-entrant structures on flat PTFE material using the previously developed procedure to familiarize yourself with the laser system as well as to obtain a base material for comparison. (2) Contact angle measurements of low surface tension liquid onto base re-entrant structure patch. (3) Application of the previously developed re-entrant structure procedure to the end of the PTFE droplet generating tip. (4) Test low surface tension fluid droplet generation ability of re-entrant structured PTFE droplet generating tip on the droplet generating tee apparatus.

Deliverables:
At the end of the four-month period, the student is expected to have altered the method of creating re-entrant structures on flat plates to impart omniphobicity to the surface of a PTFE droplet generating tip.

Description
Engineering biological tissues, either for replacement in humans or to develop controlled study platforms in the lab requires careful positioning of cells within a three-dimensional hydrogel matrix. Scaling these approaches up to allow positioning of individual cells at the tissue level is extremely challenging, and of vital importance in both understanding diseases and developing solutions. Smart materials respond to applied stimuli, and can be microfabricated to create a broad range of shapes on demand. Although these materials have been studied for decades, the possibility of using them to engineer better tissues has not yet been explored. In this project, the student will investigate various methods of processing smart materials on the micro-scale, and use the resulting 鈥榮mart scaffolds鈥� to engineer a contractile tissue with spatial control over individual cells. These precisely-designed tissues will be used immediately to study how disease progress through tissue remodeling, but more generally, this project will explore and develop new tools to engineer artificial tissues and organs..

Tasks:
The student will gain experience in materials processing, characterization, cell culture, and microscopy; and will require the student to work closely with materials scientists, engineers and biologists.

Deliverables:
The student will design, characterize and test a novel tissue microfabrication technique capable of scaled-up production of precision-engineered biological tissues.

Description
When diseases are studied in humans and in model organisms (mice, rats, etc), it is exceedingly difficult to 'watch' how the disease progresses. These studies are like watching a handful of grainy screenshots from a 3 hour long ultra HD movie. Microscale tissue engineered organs can be developed to watch these processes occur, but requires careful design of the culture platform. In this project, we aim to watch how cancer cells metastasize away from a primary tumor site, enter the blood stream, and find a site to develop the secondary tumor. Being able to watch these processes in realistic but controlled culture environments will ultimately allow us to understand the disease better, identify critical intervention points and modalities, and test new drugs and therapies..

Tasks:
AutoCAD, 3D printing, cell culture, immunostaining, microscopy.

Deliverables:
The student will design, build and test a programmable and microscale cell culture bioreactor, populate it with human cells and conduct fluorescent microscopy and image analysis.

Description
Immunotherapy using engineered and cultured immune cells has the potential to revolutionize the treatment of cancer. The principle of immunotherapy is to 鈥渢rain鈥� immune cells to detect and attack cancer cells specifically. One approach used in our lab is to harvest monocytes from blood and differentiate these cells into dendritic cells in culture vessels. These dendritic cells can then be injected into patients to activate an immune response against a specific cancer cell type. The efficacy of this approach is however highly dependent on the manufacturing process used to culture and manipulate immune cells in vitro, including culture surfaces and culture media. Culture media currently used in cell processing laboratories contain proteins that adsorb onto culture surface, which impacts cell adhesion and immunotherapy product quality. In the context of current good manufacturing practice, dendritic cell immunotherapy products are cultured in specific animal component-free media containing proteins such as albumin, transferrin and insulin. The objective of this project is to quantify protein adsorption to different cell culture surfaces, and to study the impact of these proteins on cell adhesion. This project will be conducted in collaboration with a company involved in the development of products used to manufacture therapeutic cells. The results of this project will help develop better cell manufacturing devices for medical applications such as cancer immunotherapy..

Tasks:
The trainee will measure and quantify the amount and the nature of the protein adlayer adsorbed on the surfaces developed in the laboratory, develop techniques to visualize cell interactions with the surface and develop a protocol to block cell adhesion receptors. The trainee will also participate in bi-weekly meetings with our industrial collaborator.

Deliverables:
Engineering report on the effect of adsorbed proteins on cell-surface interactions in the context of immunotherapy; oral and written presentation of the report to the collaborating company.

Description
12% of worldwide mortality is directly linked to coronary artery disease, characterized by narrowing of the arteries nourishing the heart. This necessitates the implantation of a vascular stent, a cylindrical mesh that is implanted in the narrowed area to allow maximum blood flow. Due to biocompatibility issues, the stented artery can re-narrow, putting the patient at risk of heart attack and myocardial infarction. Endothelial cells create the most biocompatible blood contacting surface known to man. Modifying the surface of stents with specific biomolecules can potentially enhance the endothelial coverage of the stent. The biomolecules would target the recruitment of endothelial progenitor cells (EPCs) to the surface, protecting against stent failure and causing regeneration of the arterial tissue. The stents we are interested in are biodegradable stents made from polylactic acid (PLA). The objective of this project is to develop a realistic in vitro stent model that will be used to optimize surface modification strategies. Specifically, the goal of the internship project is to 3D-print prototypes of PLA biodegradable stents that can be biofunctionalized and tested under flow conditions. The results of this work could play a key role in designing a new generation of surface modified vascular scaffolds that has superior long-term performance..

Tasks:
Develop micro-design of a vascular stent (CAD); optimize and produce 3D-printed biodegradable stents; test bio-functionalization of 3D-printed stents; fluorescence microscopy; image analysis, experimental design; data analysis; data presentation at group meetings; collaboration with research groups in chemical engineering and medicine at 成人VR视频, Universit茅 Laval, and the Montreal Heart Institute.

Deliverables:
Lab meeting presentation and final report describing the methods developed to 3D print and test stent models.

Description
Type 1 diabetes is a chronic autoimmune illness where the body鈥檚 immune system components attack its own insulin-producing islet cells in the pancreas. This leads to insufficient insulin production, which can be seriously detrimental without proper treatment. Islet transplantation is a newly emerged long-term treatment option for the disease, where islets are isolated from a donor鈥檚 pancreas and transplanted into recipients. To avoid immune rejection, islets can be individually encapsulated in alginate microbeads. The alginate material acts as a semipermeable membrane that should be permeable to oxygen, nutrients, and insulin, and impermeable to antibodies and immune cells, through size exclusion principles. The project will involve the optimization of an existing conventional electrostatic nozzle cell encapsulation device. The candidate should demonstrate the ability to design experiments and conduct full factorial experiments to fully characterize the encapsulator and determine the optimal settings for the application of diabetes treatment. The results of this project will be used as a 鈥済old鈥� standard for the development of novel encapsulation methods to treat type 1 diabetes..

Tasks:
Alginate bead generation using electrostatic nozzle encapsulation device; characterization of alginate beads; animal cell culture; aseptic encapsulation of beta cell lines; literature search; design of experiments; data analysis; oral and written presentation of results; contribution to lab duties.

Deliverables:
Standard operating procedure for beta cell encapsulation using a nozzle encapsulator; final report; presentation at the lab meeting.

Description:
Type 1 diabetes is an autoimmune disease in which the insulin-producing beta cells of the pancreas are destroyed. To regulate blood glucose levels, most type 1 diabetic patients require several daily doses of exogenous insulin. Islet transplantation has emerged as an alternatie long鈥憈erm treatment to insulin therapy: instead of replacing insulin, the insulin-producing beta cells found in clusters called islets of Langerhans are isolated from donors and administered to patients. Currently, this treatment can eliminate the need for insulin injections in 40% of type 1 diabetic recipients for at least 3 years. Unfortunatly, the islet supply from human donors is vastly insufficient to treat all type 1 diabetic patients. Also, recipients must take immune suppressive drugs for the rest of their life to limit graft rejection. The long-term goal of this project is to develop a transplantation device allowing the transplantation of stem cell-derived islets while avoiding the need for immune suppression. Currently, our device consists in a vessel irrigated by channels created using 3D printed carbohydrate glass (sugar) lattices. The objective of this project is to optimize the coating applied to the 3D printed carbohydrate glass networks. Different types of coatings will be applied and characterized, including measuring parameters such as coating thickness, oxygen & water permeability, wettability and mechanical properties. Preliminary thrombogenicity tests will be conducted in animals. This project is expected to lead to the design of an improved islet transplantation device to treat diabetes.

Tasks:
Aseptic cell culture of beta cell lines and primary islets; carbohydrate glass casting, coating & characterization (e.g. thickness, permeability, thrombogenicity); participation in animal studies; literature search; design of experiments; data analysis; oral and written presentation of results; presentation of research progress in bi-weekly JDRF team meetings; contribution to lab duties.

Deliverables:
Standard operating procedure for carbohydrate glass coating & sterilization procedure; final report; presentation at the lab meeting

Description
Controlled radical polymerization has allowed the development of new polymeric materials with the control of microstructure and chain length only previously accessible by ionic polymerization or other 鈥渓iving鈥� techniques. Controlled radical polymerization techniques such as nitroxide mediated polymerization (NMP), atom transfer radical polymerization (ATRP) and reversible addition/fragmentation transfer polymerization (RAFT) do not require the stringent purification of monomers, solvents and protection of functional groups required by ionic polymerization. Further, controlled radical polymerization methods can be done in aqueous media and can combine different polymer sequences, which may not be possible using ionic polymerization. Consequently, such controlled or 鈥減seudo-living鈥� radical polymerizations have become increasingly popular for the production of novel polymeric materials for controlled release, separations applications, nano-wires nano-bushings and electronic materials. Block copolymers are prominently featured in such materials, particularly for their ability to self-assemble at the nm scale. The use of block copolymers, via directed self-assembly, to form patterns at nm-scale is seen as a new method to overtake conventional photolithographic approaches for microelectronics. We will examine specifically the formation of block copolymers using monomers that are renewably sourced such as itaconic acid derivatives, myrcene and others for thermoplastic elastomers, coating materials and thin films for microelectronics..

Tasks:
The students will be responsible for the following:1) polymerization of renewably-sourced monomers using nitroxide mediated polymerization (the student will focus on monomers such as itaconates and bio-based dienes; 2)) characterization of homo and block copolymer composition and microstructure 3) processing of block copolymers into desired application (rheology for thermoplastic elastomers; films for coatings - scratch testing)

Deliverables:
1) students will present findings regularly at group meetings 2) final oral report 3) final written report

Description
Our oceans are becoming increasingly polluted by plastic waste, causing great concern as to the impact this man-made material is having on marine organisms. Research in this area has focused predominately on macro-scale organisms such as fish and birds. All life in the oceans, however, depends on microscopic organisms such as phytoplankton for the production of oxygen, and heterotrophic bacteria to break down detritus. The objective of this study is to investigate what effects plastic pollution in marine environments may be having on the physiology and ecology of these important microorganisms, with an emphasis on marine bacteria..

Tasks:
The student will learn standard operating procedures for sterile work in a class 2 lab, including training on how to work in a Biological Safety Cabinet. The student will conduct microbiological work such as culturing and enumerating marine bacteria and performing biofilm assays, as well as conducting incubation experiments with eukaryotic marine phytoplankton. The student will be introduced to advanced microscopy techniques such as fluorescence microscopy, confocal laser scanning microscopy, and/or CytoViva hyperspectral imaging. After receiving the required training in the lab (first month), the student will start working more independently. The student will be introduced to a range of research areas including environmental microbiology, microbial ecology, and ecotoxicology.

Deliverables:
A written report containing all relevant methods and results, as well as a brief literature review will be submitted. Additionally, the student will give a brief presentation to the lab group summarizing their work at the conclusion of the project.

Description
Engineered nanoparticles (ENPs) are being increasingly incorporated into commercial products. The primary driver for their use is related to the special properties of ENPs that set them apart from their bulk counterparts, such as increased catalytic, optical, magnetic or electronic capacity. These same properties that enhance the ENPs may lead to unintended consequences should ENPs be released into the environment. Given this, it鈥檚 important to examine the fate and transport of ENPs in environmentally relevant scenarios. Much of the research on environmental impacts of ENPs has been performed with pristine ENPs and represents ideal conditions. The incorporation of ENPs into commercial products however will alter these pristine nanoparticles through processes such as functionalization of the surface or embedding ENPs into polymers or other matrices. In most cases, it remains unclear how these processes will impact the ENP properties as well as their fate and transport. Additionally, incidental nanoparticles produced from the weathering of coatings and matrices remain largely unexplored. The primary objectives of this project are to investigate commercially relevant ENPs to understand how their incorporation into products may change their physicochemical properties and influence their stability in aqueous systems and their transport in porous media representative of groundwater environments..

Tasks:
The student will be trained in a range of nanotechnology and analytical/laboratory techniques that will include, for example: ENP dispersion and stabilization, determination of aggregate size via dynamic light scattering (DLS), characterization of ENP surface charge via electrophoretic mobility, and assessment of ENP mobility via laboratory column tests. After receiving the required training in the lab (first month), the student will start working more independently. The student will be introduced to a range of new areas including colloidal chemistry, aggregation theory, and environmental nanotechnology.

Deliverables:
A written report containing all relevant methods and results, as well as a brief literature review will be submitted. Additionally, the student will give a brief presentation to the lab group summarizing their work at results at the conclusion of the proj

Description
Carbon dots, also known as carbon quantum dots, have a variety of applications from chemical sensing, drug delivery, bioimaging, as well as their use in solar cells, supercapacitors, light-emitting diodes (LEDs), and fluorescent inks and paints. Currently, most quantum dots are made from heavy metals. Although, these metal-based quantum dots are well characterized and their properties can be easily tuned, there are environmental concerns with their widespread use and production. For example, cadmium is commonly used in quantum dots, but is highly toxic. Similarly, the process of mining and refining heavy metals also carries with it a significant negative impact on the environment. This project will focus on the synthesis of carbon-based quantum dots using renewable naturally-occurring compounds. The goal of this project is to further develop quantum dot technology in a sustainable manner..

Tasks:
The student will read literature on bottom-up methods of carbon dot synthesis. The student will be trained in the synthesis and purification of carbon dots as well as their characterization using UV-Vis spectroscopy and fluorescence spectroscopy. The student will be given ample guidance in improving their written and oral presentation skills, which will be valuable for any future study/work environment. After receiving the required initial training/skills in the lab (first month), the student will start working independently under the guidance of a PhD candidate. This project is part of a study on the green synthesis of carbon dots from renewable materials. The student will be introduced to a range of new research areas in nanotechnology and green chemistry.

Deliverables:
A written report containing all relevant methods and results, as well as a brief literature review will be submitted. Additionally, the student will give a brief presentation to the lab group summarizing their work at results at the conclusion of the proj

Description
Wearable devices can allow for continuous or on-demand monitoring of someone鈥檚 condition, health and surrounding environment in a non-invasive manner. Biocompatible lightweight materials could be incorporated in clothing or worn directly onto the skin. While biosensors and wearable electronics have become more and more portable in the past decade, challenges remain, such as the production cost, the design of biocompatible interfaces between biological tissues and electronics, and the ease of use. In order to produce entirely biocompatible and biodegradable wearable items in an environmentally-friendly manner, here we propose to fabricate protein-based wearable materials. Proteins can serve two functions as part of wearable devices; 1) they can act as a biopolymer scaffold that holds the material together, and that confers its flexibility and mechanical properties, 2) they can simultaneously act as the sensing or responsive element in the device. There exist several self-assembling proteins that can be used to form protein fibers, self-assembling gels, or other three-dimensional matrices. This project aims at identifying biocompatible protein candidates that can be used as matrix for the fabrication of wearable devices, and at developing methods to easily produce functional protein patches..

Tasks:
The student will be involved in all steps of the fabrication process of protein-based materials; from the rational design of proteins and genetic engineering portion, to the protein production, purification, and materials assembly. If time permits, the student will contribute to the design of a functional device.

Deliverables:
A short presentation at the end of the summer. A final report including all relevant methods, literature review and results.

Description
Soft and biocompatible materials capable of electron transfer are attractive for several applications, including biosensors, electrobiosynthetic systems, flexible electronics and low-cost energy conversion and storage devices. Using proteins and peptides to fabricate soft electronics allows for the production of multifunctional bioactive and environmentally-friendly devices. This project aims at modifying proteins that self-assemble into nanofibers to confer them with novel functionalities such as electron transport or light harvesting. These engineered conductive or light-sensitive fibers can then be used to fabricate functional coatings or thin films, and can be incorporated into devices like batteries and solar cells. Modifications of the protein fibers will be carried out through genetic engineering, self-assembly with nanomaterials, or covalent bioconjugation reactions. The electrical and optical properties of the protein nanofibers will then be characterized under different conditions..

Tasks:
The student will be involved in all steps of the fabrication process of protein-based materials; from the rational design of proteins and genetic engineering portion, to the protein production, purification, and electrical/optical characterization. If time permits, the student will contribute to the design of a functional device.

Deliverables:
A short presentation at the end of the summer. A final report including all relevant methods, literature review and results.

Description
Clathrate hydrates are ice-like solids composed of a guest gas encaged within a lattice of water molecules. Also known as gas hydrates, these crystalline solids have long been a source of trouble for the oil and gas industry, particularly in offshore projects. When light hydrocarbons, such as methane, ethane and propane, are contacted with water under high pressures and low temperatures, gas hydrates form. These solids form in blowout preventers, choke-lines, kill-lines and gas transmission lines. Gas hydrates that form in gas pipelines may accumulate and plug the pipe entirely, resulting in severe environmental, infrastructural, and economical consequences, in addition to jeopardizing the safety of working personnel. In order to better predict and understand hydrate formation, its crystallization process must be studied. Nucleation, which is the formation of microscopic clusters of hydrates that precedes the crystal growth event, is an intrinsically random event that has not been studied systematically. However, since nucleation is often the rate-limiting step in hydrate crystallization, it is imperative that engineers gain a better and more complete understanding of this phenomenon..

Tasks:
The student should have a strong background in multi-phase thermodynamics and crystallization processes. He/she will design and carry out experiments related to gas hydrate nucleation, both at atmospheric and high pressures. The time taken for a sample to nucleate (induction time) will be detected via thermal imaging. The effect of various factors, such as degree of sub-cooling and inhibitor addition, that influence the induction time of a sample will be investigated. He/she will work closely with a graduate student on this project but must also be able to work independently and diligently.

Deliverables:
Collection and analysis of experimental data for submission to his or her supervisor. The student may contribute to the writing of portions of a manuscript that may result in a publication.

Description
Water is one of the most significant compounds in nature that is not only responsible for life but also plays a significant role in many processes related to energy and safety. Water can undergo two significant phase changes when it is exposed to the proper thermodynamic conditions and components: Ice and Gas Hydrate. Ice accretion on modern infrastructure such as aircrafts, ships, offshore oil platforms, wind turbines, telecommunications and power transmission lines jeopardize their integrity and pose a significant safety hazard to operators and civilians alike. Gas hydrates on the other hand, are viewed as a new/alternative method to sustain our increasing energy demands and hence, our quality of life. Naturally occurring gas hydrates have enormous amounts of stored energy that exceeds conventional carbon reserves and mostly contain natural gas. Rheometry experiments will provide a unique insight into the flow of water, in a liquid state, but also as a slurry with soft-solids (ice and hydrate). This information is essential for the design of safe, economical, and environmentally responsible processes and facilities to deal with ice and hydrate-forming systems, as well as for the exploitation of in-situ methane hydrate as a future energy resource. A novel approach will be undertaken in this work, exploring the effects of nanomaterial surfaces and polymeric additives on both ice and gas hydrate forming systems. The goal is to elucidate the behavior of the flow of water in the presence of these surfaces and additives as it transitions to either ice or hydrate. The outcome of such work has the potential to place Canada at the forefront of technologies related to de-icing techniques that preclude ice accretion and natural gas recovery, storage and transportation..

Tasks:
The student should have a strong background in multi-phase thermodynamics and crystallization processes. He/she will design and carry out experiments related to ice and gas hydrate nucleation, both at atmospheric and high pressures and measure rheological properties. The student will investigate the effect of various factors, such as degree of sub-cooling and inhibitor addition, that influence the rheology of the phase change. He/she will work closely with a graduate student on this project but must also be able to work independently and diligently.

Deliverables:
Collection and analysis of experimental data for submission to his or her supervisor. The student may contribute to the writing of portions of a manuscript that may result in a publication.

Description
Synthetic Polymers are used in several technological applications due to their many desirable properties: low cost, good mechanical properties, resistance to corrosion and durability. However, their surfaces are typically hydrophobic which limits their wettability and biocompatibility. This issue can be addressed using surface engineering: selectively tailoring the surface properties of materials without affecting the desirable bulk properties. Cold reactive plasmas (ionized gases produced by an electrical discharge) have been used to alter a surface by the addition of functional groups or a functional layer. The project will involve the preparation of plasma deposited organic coatings with compositional gradients and their surface chemical characterization. This method has been demonstrated as promising to improve the performance of thin films for biomedical applications. The candidate should demonstrate scientific curiosity as well as maturity and autonomy. This project may lead to a Masters project..

Tasks:
- Deposition of thin organic coatings using plasma technology. - Surface analysis and characterization of the deposits - Literature search

Deliverables:
Plasma deposited set of samples and their characterization

Description
Various strategies can be used to minimize exposure of human and aquatic organisms to environmental contaminants. Two of our on-going research projects approach this issue from different perspectives. The first project aims at integrating ozone treatment with biological treatment to improve the overall performance of wastewater lagoon treatment for remote and First Nations communities in order to reduce discharges of contaminants in receiving waters, to protect the ecosystem as well as the quality of our water resources. Pilot testing will be conducted in May/June at a remote site. The objective of the second project is to determine the extent to which humans are exposed to legacy and replacement compounds, such as pthalates and their replacements, through drinking water and to evaluate the efficiency of drinking water treatment technologies in minimizing exposure to environmental contaminants. These two projects offer an opportunity to be familiarized with various environmental issues, sampling procedures and sample preparation methods and to learn different ways of assessing the quality of water..

Tasks:
The student will first get familiarized with the background information as well as the context of these projects, then will be trained on the various sample collection, preparation and analysis methods relevant to the projects, which will later be applied to the samples collected. The student will work in close collaboration with the team members to develop an experimental plan for the summer. The student will also participate in weekly research meetings and on a regular basis exchange with members of the other research groups involved in these projects, including our industrial partner.

Deliverables:
A report and presentation summarizing the data collected about exposure and performance of the prevention strategies investigated.