Observation of Hysteretic Transport Due to Dynamic Nuclear Spin Polarization in a GaAs Lateral Double Quantum Dot

We report a new transport feature in a GaAs lateral double quantum dot that emerges only for magnetic field sweeps and shows hysteresis due to dynamic nuclear spin polarization (DNP). This DNP signal appears in the Coulomb blockade regime by virtue of the finite inter-dot tunnel coupling and originates from the crossing between ground levels of the spin triplet and singlet extensively used for nuclear spin manipulations in pulsed gate experiments. The unexpectedly large signal intensity is suggestive of unbalanced DNP between the two dots, which opens up the possibility of controlling electron and nuclear spin states via DC transport.Comment: 5 pages, 4 figure

Coastal Marine Debris Mapping Using Multi-Modal Feature Extraction Pipeline

Marine debris in the ocean is becoming an increasing problem for the management of coastal oceans and seaside resort areas. This paper presents a method for coastal marine debris mapping using satellite images from multiple satellite platforms. We carry out a pilot project in association with a local government to collect in-situ measurements of debris deposited on beaches and download the coincident satellite images to identify the marine debris. We propose to study the detection of marine debris on land and in the coastal ocean with various sources of satellite imagery as a way to increase the revisit frequency. High temporal resolution data can provide an agile estimation of the resources required to mitigate the pollution accumulation on the shoreline. A major challenge of monitoring specific areas from optical satellite images is the obscuration by cloud cover, which makes it decrease the sampling frequency. To get a handle on this problem and establish high-fidelity model, we acquired the greatest number of satellite images from a variety of platforms including high temporal-resolution imagery provided by small satellite constellation programs. We first established our method using entropy of the segmentation model output on marine debris mapping in coastal areas using WorldView images provided by MAXAR corp. Then we extended the pipeline to other small satellite images using unsupervised domain adaptation techniques. We showed that the spatial representation of the segmentation map is greatly improved by the domain adaptation techniques. Whereas some dataset still requires more data samples and additional quantitative analysis, we confirmed the compatibility of the segmentation output to the established pipeline using entropy metrics to estimate the accumulation density of the debris. This analysis shows the robust capability to be able to apply the pipeline to different types of satellite images, which can be also applied in other remote sensing applications

Antena solution for future communication devices in mm-wave range

Different type of printed antennas for millimeter ranges like: high gain (narrow beam) with linear and circular polarization, sector antennas with azimuth angle of 600, 900 and 1800, omnidirectional antennas are proposed. All type suitable for integration with active microwave and millimeter wave like amplifiers, down and up convectors. Also, proposed sector and omnidirectional antennas are practically applicable for lower microwave range of 5 GHz that is included in new generation of communication systems for 60 GHz range

Reconstruction Method After Pancreaticoduodenectomy. Idea to Prevent Serious Complications

Pancreatic fistula after pancreaticoduodenectomy represents a critical trigger of potentially life-threatening complications and is also associated with markedly prolonged hospitalization. Many arguments have been proposed for the method to anastomosis the pancreatic stump with the gastrointestinal tract, such as invagination vs. duct-to-mucosa, Billroth I (Imanaga) vs. Billroth II (Whipple and/or Child) or pancreaticogastrostomy vs. pancreaticojejunostomy. Although the best method for dealing with the pancreatic stump after pancreaticoduodenectomy remains in question, recent reports described the invagination method to decrease the rate of pancreatic fistula significantly compared to the duct-to-mucosa anastomosis. In Billroth I reconstruction, more frequent anastomotic failure has been reported, and disadvantages of pancreaticogastrostomy have been identified, including an increased incidence of delayed gastric emptying and of pancreatic duct obstruction due to overgrowth by the gastric mucosa. We review recent several safety trials and methods of treating the pancreatic stump after pancreaticoduodenectomy, and demonstrate an operative procedure with its advantage of the novel reconstruction method due to our experiences

Stimulated emission from multilayer graphene

Monolayer graphene absorbs $\sim$ 2.3 percent of the incident visible light. This "small" absorption was used to emphasize visual transparency of graphene, but in fact it means that multilayer graphene absorbs sizable fraction of incident light, which causes non-negligible fluorescence. In this paper, we study the light emission properties of multilayer graphene composed of tens to hundreds of layers, because these are informative materials having interesting optical properties correlated closely with fluorescence. For example, it was recently predicted that 87-layer graphene absorbs infrared light at maximum efficiency and 20-layer graphene on silicon substrates exhibits zero reflectance (a total absence of backscattering) at a specific visible light wavelength. By modeling light emissions from multilayer graphene using a transfer matrix method, we could quantitatively explain the measured reflectivity from multilayer graphene on silicon substrates. We found sizable corrections, that cannot be classified as incoherent light emissions, to the reflectance of visible light. The new component originates from stimulated emission caused by absorption at each graphene layer, and it is a coherent sum over the amplitudes coming from all graphene layers with a common phase shift of $\pi$ relative to the incident light. The coherent corrections to the reflectance become dominant for samples thicker than 40-layers and thinner than 160-layers. Multilayer graphene thus functions as a partial coherent light source of various wavelengths and it may have surface-emitting laser applications.Comment: 9 pages, 9 figure

Autoimmune Pancreatitis Accompanied with Recurrence of Bladder Cancer: Difficulty in Diagnosis and Management of Systemic Lesions in a Case with Autoimmune Pancreatitis

Context A case of autoimmune pancreatitis develops a hepatic metastasis of bladder cancer resected over 5 years before, mimicking a pseudotumor of the liver. Case report A 71-year-old man with a surgical history of bladder cancer (pT4, G2>3, N (+)) later developed autoimmune pancreatitis. Diagnosis of autoimmune pancreatitis was not problematic; however, a variety of systemic disorders appeared after the onset of autoimmune pancreatitis, possibly associated with autoimmune disorder or steroid therapy. These included pancreatic stone attack, septic shock due to ureteral stenosis, and bloody phlegm due to a lung aspergilloma. These events were not easily controlled but were managed with clinical efforts. In the following course, pelvic lymph nodes gradually enlarged and a hepatic mass occurred at 5 years and 6 months after total cystectomy. Several candidates were considered for the hepatic lesion including inflammatory pseudotumor, cholangiocellular carcinoma, and hepatic adenoma. However, percutaneous biopsy confirmed metastasis of the bladder cancer. In general, recurrence after 5 years following cystectomy is extremely rare in cases of pT4 bladder cancer with lymph node metastasis. Conclusions Patients of autoimmune pancreatitis display various problematic scenarios in diagnosis and long-term management, not only for their pancreatic lesions but also for systemic lesions.Image: Histology of percutaneous hepatic biopsy showed urothelial carcinoma