Seven naphtho-γ-pyrones from the marine-derived fungus Alternaria alternata: structure elucidation and biological properties

Eight bioactive pyrone derivatives were identified from the culture of Alternaria alternata strain D2006, isolated from the marine soft coral Denderonephthya hemprichi, which was selected as its profound antimicrobial activities. The compounds were assigned as pyrophen (1), rubrofusarin B (2), fonsecin (3), and fonsecin B (5) beside to the four dimeric naphtho-γ-pyrones; aurasperone A (6), aurasperone B (7), aurasperone C (8), and aurasperone F (9). Structures of the isolated compounds were identified on the basis of 1D and 2D NMR spectroscopy and mass (EI, ESI, HRESI) data, and by comparison with the literature. Configuration of the four dimeric naphtho-γ-pyrones 6-9 was analyzed by CD spectra, exhibiting an identical stereochemistry

Lightweight Mutual Authentication Protocol for Low Cost RFID Tags

Radio Frequency Identification (RFID) technology one of the most promising technologies in the field of ubiquitous computing. Indeed, RFID technology may well replace barcode technology. Although it offers many advantages over other identification systems, there are also associated security risks that are not easy to be addressed. When designing a real lightweight authentication protocol for low cost RFID tags, a number of challenges arise due to the extremely limited computational, storage and communication abilities of Low-cost RFID tags. This paper proposes a real mutual authentication protocol for low cost RFID tags. The proposed protocol prevents passive attacks as active attacks are discounted when designing a protocol to meet the requirements of low cost RFID tags. However the implementation of the protocol meets the limited abilities of low cost RFID tags.Comment: 11 Pages, IJNS

SYNTHESIS AND X-RAY CRYSTALLOGRAPHY OF 2,4,6-TRIMETHYL-1,4-DIHYDRO-PYRIDINE-3,5-DICARBOXYLIC ACID DIETHYL ESTER

The biologically active 2,4,6-trimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester has been prepared and characterized by X-ray crystallography. The 1,4-dihydro-pyridine ring is in a flattened boat form, with atoms C3, and N1 being the bow and stern of the boat. Atoms C3 and N1 being 0.1346(12)A and 0.0970(12)A above the mean plane of the 1,4-dihydro-pyridine ring. One of the ethyl ester groups were found to be disordered in two positions at occupancies of 0.517 (19) and 0.483 (19) respectively. There are four molecules of 2,4,6-trimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester, in the unit cell. Inter­molecular N—H···O hydrogen bonding inter­actions were observed in the crystal lattice which connected the molecules into chain running along b-axis

Value of non-contrast CT examination of the urinary tract (stone protocol) in the detection of incidental findings and its impact upon the management

AbstractBackgroundUrolithiasis is one of the most common urinary tract diseases worldwide, with a wide range of affected age groups. Non-contrast CT examination of the urinary tract is the gold-standard examination for detection and characterization of urinary tract stones, with great impact upon the choice of method of management. Aside from detection of stones, non-contrast CT examination of the abdomen and pelvis also offers a valuable overlook upon the other abdominal organs, pathologies of which may simulate a stone disease, or accompany stone disease and can be detected incidentally, which may shift management plan dramatically.Aim of workTo demonstrate the use of non-contrast CT examinations (stone protocol) in the detection of abdominal pathologies other than stones, whether or not simulating the clinical picture of urolithiasis, and its impact upon patient management.Patients and methodsAssessment of the non-contrast examinations of the urinary tract of patients referred for suspected stone urolithiasis recording any incidental finding and follow-up of the impact of these incidental findings upon the management delivered to the patient.ResultsA total of 719 examinations were performed, of which 334 had urinary tract stones only, 211 had incidental finding beside urinary tract stones, 170 had an incidental finding with no urinary tract stones, and four patients had neither stones nor incidental findings. A total number of 381 patients had incidental findings, 198 (47%) of which had an impact upon the management.ConclusionNon-contrast CT examination of the urinary tract (stone protocol) is a valuable tool in the detection of incidental findings which may simulate, or coincide with urolithiasis and it has a significant impact upon the management of the patients

Normal testicular tissue elasticity by sonoelastography in correlation with age

AbstractPurposeThis research aimed to study the correlation between the normal testicular tissue elasticity as detected by real time sonoelastography with the age.Materials and methodsThe study was conducted upon 63 adult healthy volunteers. Each volunteer was subjected to real time sonoelastography measuring the strain ratio of testicular tissues and their elasticity scores.ResultStrain ratios of the examined testes ranged from 0.27 to 0.38, with a mean strain of 0.33 and a standard deviation of 0.03. Elasticity score of the examined testes included ES1 in 62 testes (49%), ES2 in 58 testes (46%) and ES3 in 6 testes (5%). No ES4 or ES5 was elicited in this group. High negative correlation is found between the age and both the testicular volume and the strain ratio, while there is no correlation between age and the elasticity score of testes.ConclusionNormal testicular tissues as studies by sonoelastography show strong correlation between the age and the testicular volume as well as the strain ratio

Behavior of Power System Equilibrium Points in Dynamic Available Transfer Capability Calculation

Available Transfer Capability (ATC) is of fundamental importance in electric power system planning and operation. The calculation of firm ATC in a power market environment is carried out based on day-ahead market dispatch with a set of security constraints. Incorporating dynamic security constraints into the ATC calculation not only renders a heavier burden on the computational approach, but also manifests complex system behavior in the neighborhood of its equilibrium points. This paper specifically highlights exotic system characteristics encountered during dynamic ATC calculation. The problem of ATC calculation is modeled as a nonlinear mathematical programming problem to maximize the power transfer subject to system technical and operating constraints. The dynamic ATC constraints are represented via the quadratic approximation of the stable manifold of the controlling unstable equilibrium point (UEP). A case study on the IEEE WECC 3- machine, 9-bus power system is presented and analyzed

Mansouramycins E–G, Cytotoxic Isoquinolinequinones from Marine Streptomycetes

Chemical investigation of the ethyl acetate extract from the marine-derived Streptomyces sp. isolate B1848 resulted in three new isoquinolinequinone derivatives, the mansouramycins E–G (1a–3a), in addition to the previously reported mansouramycins A (5) and D (6). Their structures were elucidated by computer-assisted interpretation of 1D and 2D NMR spectra, high-resolution mass spectrometry, and by comparison with related compounds. Cytotoxicity profiling of the mansouramycins in a panel of up to 36 tumor cell lines indicated a significant cytotoxicity and good tumor selectivity for mansouramycin F (2a), while the activity profile of E (1a) was less attractive

14-Bromo-12-chloro-2,16-dioxapentacyclohenicosa-3(8),10,12,14-tetraene-7,20-dione

In the title compound, C19H16BrClO4, both the fused xanthene rings and one of the cyclohexane rings adopt envelope conformations, while the other cyclohexane ring is in a chair conformation. In the crystal, molecules are linked by C-H...O hydrogen bonds, forming infinite chains running along [10-1] incorporating R22(16) ring motifs. In addition, C-H...[pi] interactions and weak [pi]-[pi] stacking interactions [centroid-centroid distance = 3.768 (3) Å] help to consolidate the packing