BxCyNz hybrid graphenylene: stability and electronic properties

Interest in hybrid monolayers with arrangements that differ from that of the honeycomb lattice has been growing. However, systematic investigations on the properties of these structures are still lacking. In this work, we combined density functional theory (DFT) and molecular dynamics (MD) simulations to study the stability and electronic properties of nanosheets composed of B, C, and N atoms arranged in the pattern of the carbon allotrope graphenylene. We considered twenty structures with varied atomic arrangements and stoichiometries, which we call B_xC_yN_z hybrid graphenylenes. We calculated the formation energy for each arrangement, and found that it decreases as the number of B–C and N–C bonds decreases. We also found that the structure with minimum energy has stoichiometry B₂CN and an atomic arrangement with BN and C stripes connected along the zigzag direction. Regarding the electronic properties, we found that all investigated structures are semiconductors, with band gaps ranging from 0.14 to 1.65 eV. Finally, we found that the optimized hybrid lattices presented pores of varied sizes and shapes. This diversity in pore geometry suggests that these structures might be particularly suited for molecular sieve applications.

We combine density functional theory and molecular dynamics to investigate the stability and electronic properties of 20 structures composed of boron, carbon, and nitrogen arranged in the pattern of the two-dimensional carbon allotrope graphenylene.     

A new biliary access technique for the long-term endoscopic management of intrahepatic stones

Intrahepatic stone disease poses a difficult postoperative management problem due to frequent stone recurrence. Most of the methods proposed for long-term access to the intrahepatic biliary tree require multiple sessions of additional, usually invasive, procedures. An alternative method for endoscopic long-term access to the intrahepatic ducts, represented by a side-to-side anastomosis between the isolated Roux-en-Y jejunal limb of the bilioenteric bypass and the duodenum (duodenojejunostomy), was used in eight patients with retained and/or recurrent stones after surgical treatment of intrahepatic stone disease. There were no short- or long-term complications or mortality associated with the duodenojejunostomy. Postoperative endoscopic access to the intrahepatic ducts was successfully achieved in five of six patients: one with stone recurrence, one with a left hepatic duct stricture and stone recurrence and one with known retained postoperative stones. In two patients, no stones were found at endoscopy. Side-to-side duodenojejunostomy may be useful in the long-term endoscopic management of recurrent intrahepatic biliary stone disease and should be indicated whenever a bilioenteric anastomosis is performed for the treatment of bilateral intrahepatic stone disease. Introduction     

Can the self-selection of aerobic exercise be used in individuals with different cardiorespiratory fitness levels?

Sport Sciences for Health - To compare the intensity and duration self-selected by participants with higher and lower cardiorespiratory fitness to that recommended by the American College of Sports...     

Muscle function and muscle balance in lower limbs are not impaired in individuals with general joint hypermobility

Sport Sciences for Health - The generalized joint hypermobility (GJH) syndrome is a condition characterized by a connective tissue disorder that may negatively affect the muscle function and muscle...     

In vivo specific uptake of labeled insulin by liver,adipose tissue,pituitary, and adrenals in the turtle Chrysemys dorbigni

Insulin labeled with ¹²⁵I was injected into turtles (Chrysemys dorbigni) to study its specific uptake by tissues. The maximum specific uptake of radioactivity by turtle tissues was obtained 1 hr after administration of [¹²⁵I]iodoinsulin. Besides liver and adipose tissue, specific uptake of labeled insulin was detected in some endocrine glands, such as pituitary and adrenals. Both glands were as active in concentrating labeled insulin as liver and adipose tissue. A significant reduction of the uptake was observed when unlabeled insulin was injected together with the labeled hormone. This reduction was dose dependent, and the concentration of unlabeled insulin that prevented 50% of the tissue uptake of [¹²⁵I]iodoinsulin was of 1 to 10 μg/kg body weight. These doses were able to induce blood glucose decrease in the turtle. Prolactin, growth hormone, or glucagon were unable to displace labeled insulin uptake. The major proportion of the radioactive material extracted from liver and pituitary 1 hr after [¹²⁵I]iodoinsulin injection into turtle coeluted with [¹²⁵I]iodoinsulin in Sephadex G-50 column. The presence of radioactive degradation products are consistent with the intracellular receptor mediated degradation hypothesis. These findings suggest the presence of specific insulin binding sites in liver, adipose tissue, pituitary, and adrenal glands from turtles.     

High-dose chemoradiotherapy and autologous blood stem cell transplantation in multiple myeloma: results of a phase II trial involving 63 patients

Sixty-three patients with high tumor mass multiple myeloma were treated with high-dose chemotherapy and total body irradiation supported by autologous blood stem cell transplantation. After high-dose therapy, they were monitored for a median of 44 months. Seven patients died early from toxicity. All the other patients, including those whose disease was resistant to previous therapies, showed a tumor mass reduction. At 6 months postengraftment, 40 (71%) of the surviving patients had minimal residual disease and 11 (20%) were in apparent complete remission. During follow-up, 25 out of the 63 (39%) patients relapsed and 16 of these died; 31 (49%) had a sustained remission. The median overall and event-free survival times after transplantation were 59 and 43 months, respectively. The initial serum beta 2-microglobulin value (> or < 2.8 mg/L) and length of previous therapy (> or < 6 courses of chemotherapy) were the only significant prognostic factors. In all surviving patients, blood stem cell autograft provided satisfactory and sustained haematopoietic reconstitution most often within 15 days. High dose chemoradiotherapy followed by autologous blood stem cell transplantation is thus an important therapeutic option for young patients with aggressive multiple myeloma.     

Small intestine transplantation

BACKGROUND: Significant progress has been made in clinical small bowel transplantation over the last decade mainly due advances in biotechnology and new immunosuppressive regiments. This transplantation has now been indicated to treat special cases of intestinal failure. AIM: This review highlights recent developments in the area of small bowel transplantation. MATERIAL AND METHODS: Over 600 reports on clinical and experimental small bowel transplantation were reviewed. Aspects concerning research development, different immunosuppressive strategies, patient and graft monitoring, and improvements in surgical techniques are discussed. RESULTS: About 700 small bowel transplantation were performed in 55 transplant centers, 44% intestine-liver, 41% isolated intestinal graft and 15% multivisceral transplantation. Rejection and infection are the main limitation of this procedure. Actual 5 years post transplantation graft survival of the total international experience is 46% for isolated intestinal graft, 43% for combined intestine-liver and nearly 30% for multivisceral transplantation. Higher graft and patient survival are seen at the more experienced centers. In a series of 165 intestinal transplantation at University of Pittsburgh, PA, USA, actuarial patient survival was reported to be over 75% at one year, 54% at 5 years and 42% at 10 years. Over 90% patients from Pittsburgh program resume an unrestricted oral diet. CONCLUSION: Small bowel transplantation has advanced from an experimental strategy to a feasible alternative for patients with permanent intestinal failure. Further refinements in graft acceptance, immunosuppressive regiments, infection management and prophylaxis, surgical techniques as well as appropriated patient referral and selection are crucial to improve outcomes.     

Human colonic mononuclear cells: studies of cytotoxic function.

We isolated lymphocytes from the lamina propria of colon from 19 patients with inflammatory bowel disease, colon cancer, and certain benign conditions to determine: (1) if these lymphocytes could mediate mitogen-induced (MICC) and spontaneous cell-mediated cytotoxicity (SCMC), and (2) if there were any differences in cytotoxic effectiveness which could relate to the underlying disease. We found that lamina propria lymphocytes functioned well in MICC reactions with phytohaemagglutinin, but not concanavalin A as the inducing mitogen (specific lysis 28 5% vs 5 3%). Lamina propria lymphocytes did not mediate SCMC (specific lysis 0.3%). Neither the presence of inflammation not the underlying disease of the patient influenced the cytotoxic activity. Peripheral blood lymphocytes from normal subjects and patients performed well in MICC assay with both phytohaemagglutinin and concanvalin A as the inducing mitogen and were equally effective in SCMC reactions.