448 research outputs found
Enhanced spin density wave in LaOFeSb
We predict atomic, electronic, and magnetic structures of a hypothetical
compound LaOFeSb by first-principles density-functional calculations. It is
shown that LaOFeSb prefers a stripe-type antiferromagnetic phase (i.e., spin
density wave (SDW) phase) to the non-magnetic (NM) phase, with a larger Fe spin
moment and greater SDW-NM energy difference than those of LaOFeAs. The SDW
phase is found to favor the orthorhombic structure while the tetragonal
structure is more stable in the NM phase. In the NM-phase LaOFeSb, the
electronic bandwidth near the Fermi energy is reduced compared with LaOFeAs,
indicating smaller orbital overlap between Fe states and subsequently
enhanced intra-atomic exchange coupling. The calculated Fermi surface in the NM
phase consists of three hole and two electron sheets, and shows increased
nesting between two hole and two electron sheets compared with LaOFeAs.
Monotonous changes found in our calculated material properties of LaOFePn
(Pn=P, As, and Sb), along with reported superconducting properties of doped
LaOFeP and LaOFeAs, suggest that doped LaOFeSb may have a higher
superconducting transition temperature.Comment: 5 pages with 3 figures and 1 table, double colum
Intrahepatic extramedullary hematopoiesis mimicking a hypervascular hepatic neoplasm on dynamic- and SPIO-enhanced MRI
We present a rare case of a focal intrahepatic extramedullary hematopoiesis (EMH) that mimicked a hypervascular hepatic neoplasm in a 33-year-old woman with idiopathic myelofibrosis. The lesion showed homogeneous and persistent enhancement on both contrast-enhanced CT and gadolinium-enhanced dynamic MR imaging. The lesion did not demonstrate an apparent signal drop on a T2-weighted sequence following administration of a superparamagnetic iron-oxide agent (SHU 555A). A hepatocellular adenoma was the initial radiological diagnosis. To the best of our knowledge, this is the first report of a histopathologically proven intrahepatic EMH evaluated with dynamic- and SPIO-enhanced MRI
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The Association of Maximum Body Weight on the Development of Type 2 Diabetes and Microvascular Complications: MAXWEL Study
Background: Obesity precedes the development of type 2 diabetes (T2D). However, the relationship between the magnitude and rate of weight gain to T2D development and complications, especially in non-White populations, has received less attention. Methods and Findings: We determined the association of rate and magnitude of weight gain to age at T2D diagnosis (AgeT2D), HbA1c at T2D diagnosis (HbA1cT2D), microalbuminuria, and diabetic retinopathy after adjusting for sex, BMI at age 20 years, lifestyles, family history of T2D and/or blood pressure and lipids in 2164 Korean subjects aged ≥30 years and newly diagnosed with diabetes. Body weight at age 20 years (Wt20y) was obtained by recall or from participants’ medical, school, or military records. Participants recalled their maximum weight (Wtmax) prior to T2D diagnosis and age at maximum weight (Agemax_wt). The rate of weight gain (Ratemax_wt) was calculated from magnitude of weight gain (ΔWt = Wtmax–Wt20y) divided by ΔTime (Agemax_wt –20 years). The mean Agemax_wt and AgeT2D were 41.5±10.9 years and 50.1±10.5 years, respectively. The Wt20y and Wtmax were 59.9±10.5 kg and 72.9±11.4 kg, respectively. The Ratemax_wt was 0.56±0.50 kg/year. After adjusting for risk factors, greater ΔWt and higher Ratemax_wt were significantly associated with earlier AgeT2D, higher HbA1cT2D after additional adjusting for AgeT2D, and microalbuminuria after further adjusting for HbA1cT2D and lipid profiles. Greater ΔWt and higher Ratemax_wt were also significantly associated with diabetic retinopathy. Conclusions: This finding supports public health recommendations to reduce the risk of T2D and its complications by preventing weight gain from early adulthood
Biliary complications in living donor liver transplantation: imaging findings and the roles of interventional procedures
PURPOSE: To describe the incidence, types, and findings of biliary complications in living donor liver transplantation (LDLT) and to determine the roles of interventional procedures. MATERIALS AND METHODS: Twenty-four biliary complications among 161 LDLT patients (24/161, 14.9%) were identified. These complications were divided into two groups according to the initial manifestation time, i.e., "early" (<60 days) or "late". The CT and cholangiographic findings were reviewed regarding the presence of a stricture or leak and the location, and length, shape, and degree of the stricture. Both groups were categorized into three subgroups: leak, stricture, and both. The type of interventional procedures used and their roles were determined. RESULTS: Early complications were identified in 14 of the 24 patients (58%) and late complications in 11 (46%). One patient showed both early and late complications. Biliary stricture was detected in 10 patients, leak in 10, and both in 5. By cholangiography, all strictures were irregular and short (mean length 15 +/- 6 mm) at the anastomotic site and complete obstruction was observed in 2 patients with late stricture. Twenty-three of the 24 patients were treated using percutaneous and/or endoscopic drainage procedures with or without balloon dilatation. Seventeen (74%) showed a good response, but reoperations were inevitable in 6 (26%). All patients except those with complete obstruction showed a favorable outcome after interventional management. CONCLUSION: Biliary leaks and strictures are predominant complications in LDLT. Most show good responses to interventional treatment. However, complete obstruction needs additional operative management
MDCT and Gd-EOB-DTPA Enhanced MRI Findings of Adrenal Adenoma Arising from an Ectopic Adrenal Gland within the Liver: Radiologic-Pathologic Correlation
We report a case of an adenoma arising from an ectopic adrenal gland mimicking a hepatocellular carcinoma in a heavy alcohol abuser. A MDCT showed a 2.7 low-attenuating nodule in segment VII of the liver through all CT phases. Compared to a precontrast image, however, a subtle enhancement was noted on the arterial phase CT image. On T1 weighted in- and opposed-phase MR images, an abundant fat component within the lesion was seen. Dynamic contrast-enhanced MR images after administration of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) more clearly depicted hypervascularity and wash-out of the lesion on arterial and portal phases, respectively. On delayed hepatobiliary phase MR images, obtained 20 minutes after Gd-EOB-DTPA administration, subtle uptake or retention of the contrast agent by the lesion was suspected. A tumorectomy was performed and adrenal adenoma from an ectopic adrenal gland within the liver was confirmed
Chemoenzymatic Synthesis of Glycosylated Macrolactam Analogues of the Macrolide Antibiotic YC‐17
YC‐17 is a 12‐membered ring macrolide antibiotic produced from Streptomyces venezuelae ATCC 15439 and is composed of the polyketide macrolactone 10‐deoxymethynolide appended with D‐desosamine. In order to develop structurally diverse macrolactam analogues of YC‐17 with improved therapeutic potential, a combined approach involving chemical synthesis and engineered cell‐based biotransformation was employed. Eight new antibacterial macrolactam analogues of YC‐17 were generated by supplying a novel chemically synthesized macrolactam aglycone to S. venezuelae mutants harboring plasmids capable of synthesizing several unnatural sugars for subsequent glycosylation. Some YC‐17 macrolactam analogues were active against erythromycin‐resistant bacterial pathogens and displayed improved metabolic stability in vitro. The enhanced therapeutic potential demonstrated by these glycosylated macrolactam analogues reveals the unique potential of chemoenzymatic synthesis in antibiotic drug discovery and development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113147/1/adsc_201500250_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113147/2/2697_ftp.pd
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