A clickable oxysterol photolabel retains NMDA receptor activity and accumulates in neurons

Oxysterol analogs that modulate NMDA receptor function are candidates for therapeutic development to treat neuropsychiatric disorders. However, the cellular actions of these compounds are still unclear. For instance, how these compounds are compartmentalized or trafficked in neurons is unknown. In this study, we utilized a chemical biology approach combining photolabeling and click chemistry. We introduce a biologically active oxysterol analog that contains: (1) a diazirine group, allowing for the permanent labeling of cellular targets, and (2) an alkyne group, allowing for subsequent in situ visualization using Cu2+ catalyzed cycloaddition of an azide-conjugated fluorophore. The physiological properties of this analog at NMDA receptors resemble those of other oxysterols, including occlusion with other oxysterol-like compounds. Fluorescent imaging reveals that the analog accumulates diffusely in the cytoplasm of neurons through an energy-independent mechanism. Overall, this work introduces a novel chemical biology approach to investigate oxysterol actions and introduces a tool useful for further cell biological and biochemical studies of oxysterols.</p

Microparticle manipulation using laser-induced thermophoresis and thermal convection flow

We demonstrate manipulation of microbeads with diameters from 1.5 to 10 µm and Jurkat cells within a thin fluidic device using the combined effect of thermophoresis and thermal convection. The heat flow is induced by localized absorption of laser light by a cluster of single walled carbon nanotubes, with no requirement for a treated substrate. Characterization of the system shows the speed of particle motion increases with optical power absorption and is also affected by particle size and corresponding particle suspension height within the fluid. Further analysis shows that the thermophoretic mobility (DT) is thermophobic in sign and increases linearly with particle diameter, reaching a value of 8 µm2 s−1 K−1 for a 10 µm polystyrene bead

Parallel Transjugular Intrahepatic Portosystemic Shunt with Viatorr\u3csup\u3e®\u3c/sup\u3e Stents for Primary TIPS Insufficiency: Case Series and Review of Literature

BACKGROUND Transjugular intrahepatic portosystemic shunts (TIPS) can alleviate complications of portal hypertension such as ascites and variceal bleeding by decreasing the portosystemic gradient. In limited clinical situations, parallel TIPS may be only solution to alleviate either variceal bleeding or ascites secondary to portal hypertension when the primary TIPS fails to do so. Data specifically addressing the use of this partially polytetrafluoroethylene covered nitinol stent (Viatorr®) is largely lacking despite Viatorr® being the current gold standard for modern TIPS placement. CASE SUMMARY All three patients had portal hypertension and already had a primary Viatorr® TIPS placed previously. All patients have undergone failed endoscopy to manage acute variceal bleeding before referral for a parallel stent (PS). PS were placed in patients presenting with recurrent variceal bleeding despite existence of a widely patent primary TIPS. Primary stent patency was verified with either Doppler ultrasound or intra-procedural TIPS stent venography. Doppler ultrasound follow-up imaging demonstrated complete patency of both primary and parallel TIPS. All three patients did well on clinical follow-up of up to six months and no major complications were recorded. A review of existing literature on the role of PS in the management of portal hypertension complications is discussed. There are three case reports of use of primary and PS Viatorr® stents placement, only one of which is in a patient with gastrointestinal variceal bleeding despite a patent primary Viatorr® TIPS. CONCLUSION Viatorr® PS placement in the management of variceal hemorrhage is feasible with promising short term patency and clinical follow-up data

Investigation on A Ground Source Heat Pump System Integrated With Renewable Sources

Buildings consumed 40% of the energy and represented 40% of the carbon emissions in the United States. This is more than any other sector of the U.S. economy, including transportation and industry. About 24% of all energy used in the nation is for space heating, cooling and water heating in buildings. Enhancing building efficiency represents one of the easiest, most immediate and most cost effective ways to reduce carbon emissions. One of energy efficient and environment friendly technologies with potentials for savings is Ground Source Heat Pump (GSHP) system. On the other hand, solar energy is considered as an unlimited and an environment friendly energy source, which has been widely used for solar thermal and solar power applications. This paper presents a laboratory test facility for a solar powered ground source heat pump system. The ultimate technical goal is to apply the solar powered ground source heat pump into a net-zero energy building, where all the electricity consumption will be covered by an integrated on-site solar Photovoltaics (PV) panels and battery system. The added-on benefits from this solar powered GSHP include but not limited to: 1) help further reduce electricity peak demand and 2) help further reduce greenhouse emissions. In this test rig, a ¾ - ton water-to-air GSHP is connected to two 60-feet deep wells. A group of solar PV panels of 1.12KW is connected to a battery bank, which is used to power the GSHP and a 0.27KW DC powered well pump. During the daytime, solar PV panels convert solar photons into electrical energy which will be stored into the battery bank. Whenever the GSHP system is on demand, the battery bank will provide the power. This test rig also has a comprehensive performance monitoring and data acquisition system. Well groundwater temperatures, refrigerant temperatures, air temperatures, water flow rates, etc. are all real-time monitored, trended and stored. In addition, an on-site weather station is installed to measure outside air temperature, relative humidity, wind speed and direction, and solar radiation. The details for the design and layout of this solar powered GSHP, together with the monitoring and data acquisition system will be introduced in this paper. In addition, the preliminary data collected from a testing of a cooling mode operation will be presented to illustrate the benefits of the proposed system. Finally, the feasibility of the application of the system will be discussed in the paper

Gastrointestinal Bleeding from Supraduodenal Artery with Aberrant Origin

Angiography and endovascular embolization play an important role in controlling acute arterial upper gastrointestinal hemorrhage, particularly when endoscopic intervention fails to do so. In our case, the patient presented with recurrent life-threatening bleed in spite of multiple prior endoscopic interventions and gastroduodenal artery embolization. Our teaching points focus on the role of angiography in acute upper gastrointestinal bleed and when to conduct empiric embolization, while reviewing the supraduodenal artery as an atypical but important potential culprit for refractory upper gastrointestinal bleed

Capturing the Perceived Phantom Limb through Virtual Reality

poster abstractPhantom limb is the sensation amputees may feel where the missing limb (occasionally an organ) is still attached to the body and is still moving as it would if it were there. Between 50-80% amputees report neuropathic pain, also known as phantom limb pain (PLP). Recent studies suggest that providing sensory input to the stump or amputation area may modulate how PLP can be related to neuroplastic changes in the cortex. However, there is still little understanding of why PLP occurs and there are no fully effective, long-term treatments available. Part of the problem is the difficulty for amputees to describe the sensations of their phantom limbs due to the lack of a physical limb as well as phantom limbs that are in positions that are impossible to attain. This project aims to develop an effective 3D tool with the Maya 3D animation software and the Unity game engine. The tool will then be used for those with phantom limb syndrome to communicate the sensations accurately and easily through various hand positions using a model arm with a user friendly interface. The 3D model arm will be able to mimic the phantom sensation, being able to go beyond normal joint extensions of a regular arm. This way we can have a true 3D visual of how the amputee with phantom limb feels if it is abnormal. Testing the effectiveness of the tool will involve a pilot study with able-bodied volunteers. The non-dominant limb of the volunteers will be hidden behind a blind. After putting their limb in a random position, they will attempt to capture the limb on the 3D model. The actual position and captured position will be compared to determine the reproducibility and accuracy of the virtual limb. By taking advantage of computer graphics, virtual reality and computerized image capture technologies we are hoping to achieve a far less challenging way to quickly and accurately capture the position and striking feelings of the phantom limb sensation