Valley-dependent spin polarization in bulk MoS2 with broken inversion symmetry.

The valley degree of freedom of electrons is attracting growing interest as a carrier of information in various materials, including graphene, diamond and monolayer transition-metal dichalcogenides. The monolayer transition-metal dichalcogenides are semiconducting and are unique due to the coupling between the spin and valley degrees of freedom originating from the relativistic spin-orbit interaction. Here, we report the direct observation of valley-dependent out-of-plane spin polarization in an archetypal transition-metal dichalcogenide--MoS2--using spin- and angle-resolved photoemission spectroscopy. The result is in fair agreement with a first-principles theoretical prediction. This was made possible by choosing a 3R polytype crystal, which has a non-centrosymmetric structure, rather than the conventional centrosymmetric 2H form. We also confirm robust valley polarization in the 3R form by means of circularly polarized photoluminescence spectroscopy. Non-centrosymmetric transition-metal dichalcogenide crystals may provide a firm basis for the development of magnetic and electric manipulation of spin/valley degrees of freedom.

Superconducting dome in a gate-tuned band insulator.

A dome-shaped superconducting region appears in the phase diagrams of many unconventional superconductors. In doped band insulators, however, reaching optimal superconductivity by the fine-tuning of carriers has seldom been seen. We report the observation of a superconducting dome in the temperature-carrier density phase diagram of MoS(2), an archetypal band insulator. By quasi-continuous electrostatic carrier doping achieved through a combination of liquid and solid gating, we revealed a large enhancement in the transition temperature T(c) occurring at optimal doping in the chemically inaccessible low-carrier density regime. This observation indicates that the superconducting dome may arise even in doped band insulators.

A case of lupus erythematosus profundus with multiple arc-shaped erythematous plaques on the scalp and a review of the literature.

A 26-year-old Japanese female presented to us with a 2-year history of multiple arc-shaped erythematous lesions on her scalp and the right side of her forehead. Histopathological examination of two of the lesions showed lobular and septal panniculitis with deposits of IgG in the basement membrane zone. We diagnosed the case as lupus erythematosus profundus, and successfully treated her with 20 mg/day prednisolone. To our knowledge, there has been only one previously reported case of lupus erythematosus profundus with annular-shaped erythematous lesions and six cases with linear configuration.

Pancreatic sphincter precutting to gain selective access to the common bile duct: a series of 172 patients.

BACKGROUND AND STUDY AIMS: Several precutting techniques have been described in cases of failed access to the common bile duct. We describe our experience with pancreatic sphincter precutting in an upward direction, and report its success rates and complications. PATIENTS AND METHODS: A total of 172 patients underwent a procedure using this technique between January 1989 and December 2001. The technique consisted of a medium-to-large precut along the midline, above the papillary elevation, using either the common channel or the pancreatic duct in the ampulla of Vater as a guide. The septum between the pancreatic duct and the bile duct was removed and separate openings to the pancreatic and bile ducts were created, followed by complete biliary sphincterotomy. RESULTS: Biliary cannulation and sphincterotomy was successful in 163 of the 172 study patients (95 %). Mild complications, which were all managed conservatively, occurred in 17 patients (10 %). This complication rate was significantly higher than our complication rate for standard endoscopic sphincterotomy, which was 0.8 % in 1770 patients ( P < 0.0001). CONCLUSIONS: Pancreatic sphincter precutting is an effective and safe technique for patients in whom selective cannulation of the common bile duct has failed. Further prospective comparative studies of other precutting techniques will better define its clinical value.

[A case of percutaneous and transpapillary placements of expandable metallic stents in a patient with cholangiocarcinoma at the hilum of the liver].

A 76-year-old woman was admitted with obstructive jaundice. US and MR cholangiopancreatography (MRCP) revealed an inoperative cholangiocarcinoma, 3 cm in diameter at the hilum of the liver, the obstruction of the hepatic duct bifurcation and the separation of bilateral hepatic bile ducts. Percutaneous transhepatic biliary drainage (PTBD) was performed from bilateral hepatic bile ducts. The right PTBD tube was spontaneously extubated. We could not succeed in performing internal biliary drainage across the hilar malignant stricture from a left hepatic bile duct, because of bad angulation. Transpapillary insertion into the common bile duct (CBD) was extremely difficult due to the collapse of the CBD. Endoscopic sphincterotomy (EST) after precutting method was performed. Although we performed the ballooned dilatation of malignant stricture and the insertion of a self-expandable metallic stent (EMS) into a right hepatic bile duct transpapillary. After dilatation of the hilar malignant stricture by the initial EMS, we inserted a guidewire into the CBD through the wire mesh of a stent from the left PTBD tube. We could insert the second EMS from a left hepatic bile duct to the CBD transhepatically, using a dilator and a dilating balloon. Finally, we performed the ballooned dilatation from bilateral hepatic bile ducts to the CBD transpapillary. She was discharged after bilateral internal biliary drainages, successfully.

[An extremely elderly patient with choledocholithiasis and many complications].

It was very difficult to treat a 90-year-old woman for choledocholithiasis with acute obstructive suppurative cholangitis, gallbladder perforation, and a pool of bile in the right perirenal spase. Extracorporeal shockwave lithotripsy (ESWL) was performed after emergency percutaneous transhepatic biliary drainage (PTBD), but we could not perform lithotripsy successfully because of large and hard stones. Although Endoscopic sphincterotomy (EST) was performed using an ultratome by rendezvous method. Lithotripsy was finally successful, after three times endoscopic mechanical lithotripsy (EML) and procedure using an endotriptor for basket impaction. It is very important in advanced aged patients that endoscopic treatment should be performed step by step.

[An elderly case of post-bulbar Dieulafoy's ulcer].

The case is a 79-year-old man who came to our hospital with melena as chief complaint. Emergency endoscopy showed spurting bleeding from a small ulcer. We diagnosed as Post-Bulbar Dieulafoy's ulcer and performed hemostatic procedure with hemostatic clips. The forth endoscopy (7 days after admission) showed fresh clot and oozing bleeding after the third hemostatic clipping. Although we performed hemostatic procedure with the injection therapy of hypertonic saline epinephrine solution (HSE). The effective hemostatic procedure is discussed with reference to some related literature.

[Surgical treatment of secondary chronic colonic pseudo-obstruction].

A 74-year-old woman was admitted to the hospital because of constipation and marked abdominal distension. She had become to be bedridden after cerebral infarction 10 years previously, and was tabescent due to vomiting. A left hemicolectomy and colostomy were performed because conservative therapy seemed to be ineffective. The postoperative course was good and her nutritional status improved.

[A case of endocrine cell carcinoma in the duodenal bulb].

A 73-year-old man was admitted to our hospital due to weight loss and melena. Roentgenograms and endoscopy showed a Borrmann type 2 tumor occupying the entire duodenal bulb. Histological findings of the lesion (H-E stain) showed poorly differentiated adenocarcinoma. Almost the entire specimen showed positive staining granules for Grimelius stain. Ultrastructurally, remarkable endocrine granules covered a layer of the limited membrane (membrane-bound granule) in the tumor cell. We diagnosed endocrine cell carcinoma. Since it was difficult to operate due to age and invasion to the fundus of the gall-bladder and the pancreatic head, we treated this case by chemotherapy.

[A case of Lemmel's syndrome caused by a large diverticular enterolith at the peripapillary portion of the duodenum].

A 93-year-old woman admitted because of epigastralgia. Cholelithiasis, obstructive jaundice, acute suppurative cholangitis and acute pancreatitis were diagnosed on blood chemistry and ultrasonography on admission. We performed emergency PTCD. A calculus 4 cm in diameter was detected at the papilla of Vater and marked dilatation of the common bile duct and pancreatic duct. ESWL was performed because of her age and because endoscopical operation seemed to be difficult. After lithotripsy, PTC and endoscopy demonstrated a diverticulum at the peripapillary portion of the duodenum. Based on analysis of PTC result before and after ESWL, we diagnosed this case as Lemmel's syndrome (obstructive jaundice, acute suppurative cholangitis and acute pancreatitis) caused by a large diverticular enterolith at the peripapillary portion of the duodenum. ESWL treatment of aged patient with an enterolith is safe.

[A case of early duodenal cancer resected by endoscopic polypectomy in the elderly].

Early duodenal cancer has been detected with increasing frequency of endoscopy and the advent of an aging society. Aged patients, however, are often inoperable because of complications due to various underlying diseases. The authors report a case of early duodenal cancer curatively operated by endoscopic polypectomy and refer to related cases in the literature.

[Upper gastrointestinal bleeding in the elderly].

Due to increasing number of the elderly, cases of hematemesis and melena in the aged have been increasing. The authors evaluated 69 such cases over 60 years old in whom emergency endoscopy of the upper digestive tract was carried out because of hematemesis and melena. Twenty cases are diagnosed as gastric ulcer (29%), 12 cases as esophageal ulcer and esophageal erosion (17.4%), 9 as duodenal ulcer (13.0%), 7 as gastric cancer (10.1%), 6 as Mallory-Weiss syndrome (8.7%), 6 as esophageal and gastric varices (8.7%), 4 as acute hemorrhagic gastritis (5.8%), 3 as Dieulafoy's ulcer (4.3%), and one case each of chronic pancreatitis (hemosuccus pancreaticus) and hemorrhage due to gastric angiodysplasia (1.4%). Of these cases, blood transfusion was performed in 46 cases (66.7%), and shock occurred in 27 cases (39.1%). The endoscopical hemostatic procedure was effective for detection of underlying diseases in the aged. Surgery was often impossible because of the rapid deterioration of the systemic condition due to the hemorrhage of the digestive tract.

Class II antigen expression by lacrimal epithelial cells. An updated working hypothesis for antigen presentation by epithelial cells.

It has been suggested that aberrant expression of Class II histocompatibility antigens (HLA) is involved in T cell activation and leads to autoimmunity. Although Class II antigen expression was found in various nonlymphoid tissues, including salivary glands, its expression on lacrimal epithelial cells has not been reported. In this study, 12 cadaver lacrimal glands were analyzed for HLA-DR and for the numbers and distributions of T suppressor cells (Ts), T helper cells (Th), B cells, and macrophages. None of these cases exhibited the high numbers of inflammatory cells, tissue damage, and fibrosis characteristic of Sjogren's syndrome. The HLA-DR-positive epithelial cells were detected in ten cases; they represented from less than 1% to more than 70% of the epithelial cells. In these ten positive cases, there were greater numbers of T cells per millimeter squared (229 +/- 94 [mean +/- the standard error of the mean]) than in the two HLA-DR-negative cases (37 +/- 1 [mean +/- range]). Three lacrimal gland specimens tested were negative for immunoglobulin (Ig) G-bearing B cells, and two of the three specimens tested had IgA-bearing cells. Acinar cells were isolated from rat and rabbit lacrimal glands and cultured overnight in serum-free media supplemented with several potential mediators of Class II antigen expression: interferon-gamma, carbachol, or isoproterenol. Freshly isolated cells did not express Class II antigens at detectable levels, but in most experiments, they began to express the antigen even in the absence of putative mediators.(ABSTRACT TRUNCATED AT 250 WORDS)

Light-inducible pigmentation in Portulaca callus; selection of a high betalain producing cell line.

We have established a unique betalain pigmentation system in callus cultures that originated from seedlings of Portulaca sp. 'Jewel'. Within three different 'Jewel' lines examined, one line (JR) was clearly superior with regard to callus growth rate and pigment formation. Furthermore, after ten cycles of selection of deeply colored callus patches, the selected clones contained on an average four times the amount of betalain as compared to the non-selected mother line. The colorization was induced by light, but disappeared in the dark. Pigment synthesis was detectable within 30 h after irradiation and showed positive correlation with irradiation periods.

Low-friction hydrophilic surface for medical devices.

A hydrophilic polymer surface was developed exhibiting excellent low frictional property, namely slipperiness, when in contact with water or physiological fluid due to the reaction of epoxy-containing poly(vinyl pyrrolidone) with the polyamino compound formed on the surface of the substrate. Epoxy-containing poly(vinyl pyrrolidone) was obtained by the copolymerization of vinyl pyrrolidone as a hydrophilic component, glycidyl acrylate as a binding component to the substrate, and vinyl acetate to preserve the strength of the coating layer. The surface friction coefficient depends on the molecular weight of the coated hydrophilic copolymer. It was demonstrated that a molecular weight of 400,000 or more is essential to achieve excellent low surface friction. Using rabbit models, polyurethane catheters, both with and without the hydrophilic low friction coating, were evaluated for surface friction coefficient and blood compatibility. As a result, in the case of coated catheters, no lesions of the intima of the blood vessels and no thrombus formations on the surfaces of the catheters were observed. However, the non-coated catheters injured the intima of the blood vessels and severe thrombus formation was found on their surfaces.