Information-to-work conversion by Maxwell's demon in a superconducting circuit quantum electrodynamical system.

Information thermodynamics bridges information theory and statistical physics by connecting information content and entropy production through measurement and feedback control. Maxwell's demon is a hypothetical character that uses information about a system to reduce its entropy. Here we realize a Maxwell's demon acting on a superconducting quantum circuit. We implement quantum non-demolition projective measurement and feedback operation of a qubit and verify the generalized integral fluctuation theorem. We also evaluate the conversion efficiency from information gain to work in the feedback protocol. Our experiment constitutes a step toward experimental studies of quantum information thermodynamics in artificially made quantum machines.

[Clinicopathological features and diagnostic points of uncommon pancreatic tumors].

Clinicopathological features of uncommon pancreatic tumors including solid cystic tumor (SCT), acinar cell carcinoma and pancreatoblastoma are described, based upon a literature survey and own experiences. They are often discovered by US and CT as asymptomatic pseudocystic tumor. SCTs almost always occur in young female and Pancreatoblastoma, in children less than five years old. The prognosis is very favorable in SCT, and relatively good in acinar cell carcinoma and pancreatoblastoma. Pancreatoblastoma is often associated with the elevation of serum AFP levels. Characteristic histological features and immunocytochemical features are also described, all of which are very different from those of usual pancreatic ductal carcinoma. Molecular biological features including the results of k-ras and p53 point mutation are also discussed. In addition to the clinicopathological features, these uncommon tumors are very different from usual ductal carcinoma in the molecular biological features.

Epidermoid cyst derived from an accessory spleen in the pancreas. A case report with literature survey.

A rare case of splenic epidermoid cyst (SEC) of the pancreas discovered in a 32-year-old Japanese female is reported. The lesion, 5 x 6 cm in size including caseous material and serous fluid in the lumen, was discovered by ultrasonography and computed tomography at the tail of the pancreas and was easily removed. Histopathologically, the cystic wall consisted of three components: the inside was lined by mature squamous epithelium with keratinization, the middle layer consisted of splenic pulp with a sinus structure, and the peripheral layer was dense fibrous connective tissue in which some involutional pancreatic ducts and islets were recognized. The literature about SEC of the pancreas is discussed in comparison with other types of epidermoid cyst including lymphoepithelial cyst and dermoid cyst in the pancreas.

Lymphoepithelial cyst of the pancreas: a preoperatively diagnosed case based on an aspiration biopsy.

This paper reports an extremely rare case of lymphoepithelial cyst of the pancreas. The patient, a 58-year-old man with no subjective symptoms, was found to have a pancreatic tumor during a physical examination. He visited our clinic and was admitted for a follow-up examination. Based on the ultrasonographic findings, superselective angiography, and aspiration biopsy, an epidermoid cyst was diagnosed. Enucleation was easily performed. Macroscopically, this cyst resembled an atheroma. Histologically, the cavity of the cyst was lined with a squamous epithelium with a nucleated layer and below that, lymphatic tissue. No malignancy was found. Tumors of the pancreas with a squamous epithelial covering are extremely rare; only a few such cases have been reported in the literature. As of 1991, only 12 cases, including the present case, had been reported. With the advances in diagnostic techniques, the detection of pancreatic tumors is expected to improve. This paper reports a case in which the use of an aspiration biopsy and superselective angiography proved to be useful in making an accurate diagnosis.