Turbulent transport reduction induced by transition on radial electric field shear and curvature through amplitude and cross-phase in torus plasma

Spatiotemporal evolutions of radial electric field and turbulence are measured simultaneously in the H-mode transition, which is a prototypical example of turbulence structure formation in high-temperature plasmas. In the dynamical phase where transport barrier is established abruptly, the time-space-frequency-resolved turbulent particle flux is obtained. Here we report the validation of the mechanism of transport barrier formation quantitatively. It is found that the particle flux is suppressed predominantly by reducing density fluctuation amplitude and cross phase between density fluctuation and potential fluctuation. Both radial electric field shear and curvature are responsible for the amplitude suppression as was predicted by theory. Turbulence amplitude reduction immediately responds to the growth of the radial electric field non-uniformity and saturates, while cross phase continuously approaches zero.

Antegrade jejunogastric intussusception and common bile duct stones at 14 months after gastrectomy and cholecystectomy: A case report

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Jejunogastric intussusception occurred after distal gastrectomy followed by Roux-en Y reconstruction.

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Common bile duct stone occurred after prophylactic cholecystectomy and distal gastrectomy.

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Intussusception and common bile duct stone both could occur simultaneously after gastrectomy.

Introduction

Intussusception after gastrectomy is a minor complication after gastrectomy, while common bile duct stone (CBD) is also a rare complication post cholecystectomy. We report a case that simultaneously caused both intussusception and CBD stone following gastrectomy with prophylactic cholecystectomy.

Case presentation

A 74-year-old woman underwent distal gastrectomy with Roux-en-Y reconstruction and prophylactic cholecystectomy for gastric cancer. After 14 months, the patient reported nausea and vomiting. Abdominal computed tomography scanning showed antegrade intussusception of the Roux limb of the gastrojejunostomy and calculi in the common bile duct, with a diagnosis of jejunogastric intussusception and common bile duct stones. The patient was hospitalized and endoscopic examination was performed on day 3. Endoscopic treatment did not resolve the intussusception, which also obstructed the bile duct stones. Elective surgery was performed on day 10, in which the invaginated Roux limb of the gastrojejunostomy was resected after manual reinstatement to its original position. This was followed by open exploration of the common bile duct and T-tube drainage. The patient was discharged 25 days post- surgery.

Discussion

Jejunogastric intussusception and CBD stone may require operative management, although the operation could be elective after sufficient examination and preparation.

Conclusion

Jejunogastric intussusception and bile duct stones are rare after distal gastrectomy, physicians should be alerted to the possibility of these complications.

Culturing Periosteum in Vitro: The Influence of Different Sizes of Explants

Periosteal transplantation is being used clinically to repair articular defects. Isolated cells and very small periosteal explants can be grown in tissue culture, but it will be necessary to test larger sizes for tissue engineering to be applied to clinical transplantation of periosteum. This study was conducted to assess the chondrogenic potential of different sizes of periosteal explants in agarose culture. Ninety-six rabbit tibial periosteal explants in three different sizes (small 1.5 × 2, medium 3 × 2, and large 4 × 6 mm, 32 pieces per size) were cultured in agarose suspension for 6 wk and given TGF-β1 (10 ng/mL) for the first 2 wk. Tissue growth, as indicated by normalized final wet weights of the explants after 6 wk in culture, was inversely proportional to explant size. Cartilage formation was observed in all explante. Histomorphometry revealed that cartilage formation was significantly better for the smaller explants (80% cartilage), but similar in the medium and larger explants (60% cartilage). Similar proportions of type II collagen were present in the different-sized explants. This study demonstrates that various sizes of periosteal explants can be grown in culture. Abundant cartilage was produced even by the large explants. © 1998 Elsevier Science Inc.

Crystallographic and electronic properties of AlCrN films that absorb visible light

We investigate the crystallographic and electronic properties of wurtzite Cr-doped AlN (AlCrN) films (Cr ≤12.0%) that absorb visible light. We confirmed that the films consist of wurtzite columnar single crystals that are densely packed, c-axis oriented, and exhibit a random rotation along the a-axis in plane by using transmission electron microscopy. The oxidation state of Cr was found to be 3+ using Cr K-edge X-ray absorption near edge structure, which implies that Cr can be a substitute for Al3+ in AlN. The first nearest neighbor distances estimated using Cr K-edge extended X-ray absorption fine structure (EXAFS) were found to be nearly isotropic for incident light with electric fields that are parallel and perpendicular to the plane. The results of ab initio lattice relaxation calculations for the model of wurtzite Al1-xCrxN supercell where Cr replaces Al support the EXAFS results. The calculations for the model showed that additional energy bands are formed in the band gap of AlN, in which the Fermi energy (EF ) is present. As expected from the calculation results, the electrical conductivity increases with increase in the Cr concentration, implying that the density of states at EF increases monotonically. From these results, we can conclude that AlCrN films are an intermediate band material with respect to their crystallographic and electric properties.