bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved QSAR modeling of anti-HIV-1 acivities by means of the optimized correlation weights of local graph invariants
Authors: Marino Damián , Castro Eduardo , Toropov Andrey 
Published: February 2006

AbstractWe report the results derived from the use of molecular descriptors calculated with the correlation weights (CWs) of local graph invariants for modeling of anti-HIV-1 potencies of two groups of reverse transcriptase inhibitors. The presence of different chemical elements in the molecular structure of the inhibitors and the Morgan extended connectivity values of zeroth-, first-, and second order have been examined as local graph invariants in the labeled hydrogen-filled graphs. We have computed via Monte Carlo optimization procedure the values of CWs which produce the largest possible correlation coefficient between the numerical data on the anti-HIV-1 potencies and those values of the descriptors on the training set. The model of the anti-HIV-1 activity obtained with compounds of training set by means of optimization of correlation weights of chemical elements present together with Morgan extended connectivity of first order makes up a sensible model for a satisfactory prediction of the endpoints of the compounds belonging to the test set.
Oxovanadium(IV) complexes of bromo-and methoxy substituted N1,N4-diarylidene-S-methylthiosemicarbazones
Authors: Demirci Tülay. , Köseoğlu Yüksel , Güner Sadik , Ülküseven Bahri 
Published: February 2006

AbstractFour new oxovanadium(IV) compounds were prepared by template reaction of salicyl-, 5-bromosalicyl-and 3-methoxysalicyl-aldehyde S-methylthiosemicarbazones with 2-hydroxy-, 5-bromo-2-hydroxy-and 3-methoxy-2-hydroxy-benzaldehyde in various combinations. The compounds were isolated as stable solid compounds with general formula [VO(L)] and characterized by elemental analysis, conductivity and magnetic measurements, electronic, IR and EPR spectroscopy. The X-band EPR signals recorded from powder forms of all samples have a single asymmetric line shape and theoretical fit studies proved the presence of axial symmetry around the paramagnetic vanadium ions. The anisotropic Lande splitting factors take values of g‖ < g⊥ < ge = 2.0023. Orbital energy levels for magnetic electrons were determined from theoretically well fitted Spin Hamiltonian parameters. The EPR spectra recorded from solution forms almost have isotropic character.
Two-step synthesis of high aspect ratio gold nanorods
Authors: Mortier Tom , Persoons André , Verbiest Thierry 
Published: February 2006

AbstractWe describe a very simple, two-step synthetic method to prepare gold nanorods with extremely high aspect ratios (> 20) and average lengths of more than 1000 nm. The method is based on a seed-mediated growth in presence of the surfactant cetyltrimethylammonium bromide. The length and aspect ratios of the nanorods can be manipulated by varying the surfactant concentration.
Phase formation and microstructure in Re1-x CaxBa2Cu3Oz (Re=Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics
Authors: Stoyanova-Ivanova A.K. , Terzieva S.D. , Staneva A.D. , Mikli V. , Traksmaa R. , Dimitriev Y.B. , Kovachev V.T. 
Published: February 2006

AbstractWe have investigated the influence of Ca-substitution and different rare earths on the microstructure of RE1-x
CaxBa2Cu3O7-δ
(RE= Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics. Scanning electron microscopy, X-ray microanalysis and energy dispersive spectroscopy have been used to study the microstructure and the chemical composition of the samples. A correlation was established between the polycrystalline microstructure and phase formation depending on the additive content. We observed that calcium is distributed uniformly in the crystals. The formation of minor impurity phases improved the sintering conditions.
Density and surface tension of the systems CaO-FeO-Fe2O3-MgO, CaO-FeO-Fe2O3-ZnO and CaO-Fe2O3-Cu2O
Authors: Vadász Pavol , Havlík Milan , Daněk Vladimír 
Published: February 2006

AbstractThe density and surface tension of melts of the systems CaO-FeO-Fe2O3 MgO at the temperature 1623 K, CaO-FeO-Fe2O3-ZnO at 1573 K, and CaO-Fe2O3-Cu2O at 1573 K were determined using the maximum bubble pressure method. The molar volume, the excess molar volume, and the excess surface tension were calculated on the basis of the obtained data. From these properties information on the interactions of components and possible chemical reactions between them was obtained. Due to the absence of silica and the low concentration of other network-forming oxides, only isolated FeO45− tetrahedra and the CaO·FeO ionic pairs are formed in these basic melts, the donor of the oxygen atoms being either CaO, FeO, or both CaO+FeO oxides. Even the observed ternary interactions may be attributed to the formation of the anions FeO45− only.
AFM study of complement system assembly initiated by antigen-antibody complex
Authors: Ramanaviciene Almira , Snitka Valentinas , Mieliauskiene Rasa , Kazlauskas Rolandas , Ramanavicius Arunas 
Published: February 2006

AbstractThe shape and size of complement system C1 components assembled on a SiO2 surface after classical activation by antigen-antibody complex was determined by tapping mode atomic force microscopy (AFM). The SiO2 substrate was silanized and bovine leukemia virus proteins gp51 were covalently bound to the SiO2 substrate. Self-assembly of complement system proteins was investigated by AFM. Uniform coating of silanized surface by gp51 proteins was observed by AFM. After incubation of gp51 coated substrate in anti-gp51 antibody containing solution, Ag-Ab complexes were detected on the substrate surface by AFM. Then after treatment of Ag-Ab complex modified substrate by guinea-pig blood serum containing highly active complement system proteins for 3 minutes and 30 minutes features 2–3 times and 5–8 times higher in diameter and in height if compared with those observed after formation of Ag-Ab complex, were observed respectively on the surface of SiO2. This study revealed that AFM might be applied for the imaging of complement system assembly and provides valuable information that can be used to complement other well-established techniques.
Exact laws for sums of ratios of order statistics from the Pareto distribution
Authors: Adler André 
Published: February 2006

Abstract
Consider independent and identically distributed random variables {X
nk, 1 ≤ k ≤ m, n ≤ 1} from the Pareto distribution. We select two order statistics from each row, X
n(i) ≤ X
n(j), for 1 ≤ i < j ≤ = m. Then we test to see whether or not Laws of Large Numbers with nonzero limits exist for weighted sums of the random variables R
ij = X
n(j)/X
n(i).
On the doubly connected domination number of a graph
Authors: Cyman Joanna , Lemańska Magdalena , Raczek Joanna 
Published: February 2006

Abstract
For a given connected graph G = (V, E), a set
$$D \subseteq V(G)$$
is a doubly connected dominating set if it is dominating and both 〈D〉 and 〈V (G)-D〉 are connected. The cardinality of the minimum doubly connected dominating set in G is the doubly connected domination number. We investigate several properties of doubly connected dominating sets and give some bounds on the doubly connected domination number.
Hitting distributions domination and subordinate resolvents; an analytic approach
Authors: Boboc Nicu , Bucur Gheorghe 
Published: February 2006

Abstract
We give an analytic version of the well known Shih's theorem concerning the Markov processes whose hitting distributions are dominated by those of a given process. The treatment is purely analytic, completely different from Shih's arguments and improves essentially his result (in the case when the given processes are transient
Modulation of the epithelial barrier by dexamethasone and prolactin in cultured Madin—Darby canine kidney (MDCK) cells
Authors: Peixoto E.B.M.I. , Collares‐Buzato C.B. 
Published: February 2006

AbstractGlucocorticoids and prolactin (PRL) have a direct effect on the formation and maintenance of tight junctions (TJs) in cultured endothelial and mammary gland epithelial cells. In this work, we investigated the effect of a synthetic glucocorticoid dexamethasone (DEX) and PRL on the paracellular barrier function in MDCK renal epithelial cells. DEX (4 μM) + PRL (2 μg/ml) and DEX alone increased significantly the transepithelial electrical resistance after chronic treatment (4 days) of confluent MDCK monolayers or after 24 h treatment of subconfluent monolayers. Immunoblotting and immunocytochemistry revealed no changes in the expression and distribution of TJ‐associated proteins occludin, ZO‐1 and claudin‐1 in confluent monolayers after hormone addition. However, a marked increase in junctional content for occludin and ZO‐1 with no changes in their total expression was observed in subconfluent MDCK monolayers 24 h exposed to DEX or DEX + PRL. No change in cell proliferation/growth was detected at subconfluent conditions following hormone treatment. An increase in the total number of viable cells was observed only in confluent MDCK monolayers after exposure to DEX + PRL suggesting that the main effect of these hormones on already established barrier may be associated with the inhibition of cell death. In conclusion, our data suggest that these hormones (specially dexamethasone) have an effect on TJ structure and function only during the formation of MDCK epithelial barrier by probably modulating the localization, stability or assembly of TJ proteins to membrane sites of intercellular contact.
Involvement of caspase‐3 pathway in anti‐apoptotic action of methionine enkephalin on CEM × 174 cells in prolonged infection with simian immunodeficiency virus in vitro
Authors: Xu Jin , Xin Shuqin , Li Hui , Liu Lin , Xia Weiyi , Li Pingfeng , Liu Xinhua , Li Gang 
Published: February 2006

AbstractThe roles of methionine enkephalin, as an immunomodulator, on immunodeficiency virus‐induced apoptosis of lymphocytes during prolonged infection are still unclear. In the present study, we evaluated the effects of methionine enkephalin on the viability, the profile of cell cycle and apoptosis, as well as the expression of apoptosis‐related genes in CEM × 174 cells infected with simian immunodeficiency virus for 72 h. Our data demonstrated that methionine enkephalin maintains the viability of cells during the period of prolonged infection. Following co‐incubation with the virus, CEM × 174 cells were arrested at S phase, with increased mortality as a result of apoptosis. Methionine enkephalin could abolish virus‐induced over‐expression of caspase‐3. Taken together all findings, we conclude that methionine enkephalin may maintain the viability of SIV‐infected cells via suppressing the expression of caspase‐3, which may have clinical implications in opioid peptide therapy for AIDS.
The effect of altering haemodynamics on the plasma concentrations of natriuretic peptides in heart failure
Authors: Larsen A.I. , Dickstein K. , Ahmadi N.S. , Aarsland T. , Kvaløy J.T. , Hall C. 
Published: February 2006

AbstractBackgroundNatriuretic peptide levels reflect haemodynamics in patients with heart failure and may serve as biochemical markers of cardiac filling pressures. The purpose of this study was to detect differences in the kinetic profile between atrial natriuretic peptide (ANP), B‐type natriuretic peptide (BNP) and their N‐terminal fragments N‐ANP and N‐BNP, in response to rapid and persistent vasodilatation.MethodsSixteen men and four women aged 63.0 ± 10.4 (mean ± S.D.) with symptomatic congestive heart failure (NYHA III) and pulmonary capillary wedge pressure (PCWP) > 18 mm Hg, received a 24‐h infusion of nitroglycerin (N= 8) or nicorandil (N= 12). A reduction of PCWP was achieved for the duration of the study. Natriuretic peptides were measured by radioimmunoassay at baseline, 1, 3, 6, 12 and 24 h.ResultsPCWP and right atrial pressure fell rapidly and then increased modestly. ANP and N‐ANP demonstrated a similar pattern. In contrast, BNP and N‐BNP levels fell steadily throughout the observation period. This was accompanied by a continuous reduction of systemic vascular resistance (SVR). PCWP was highly correlated to the levels of all the natriuretic peptides. Using alongitudinal regression modelevaluating responses over time, we found separate, significant relationships between all peptides and haemodynamic variablesConclusionThe atrial natriuretic peptides reflect rapid changes in filling pressures while the B‐type peptides respond much slower. B‐type peptides are less sensitive to short‐term changes in filling pressures, but should reflect changes in SVR better during vasodilator therapy.
Biventricular versus right ventricular pacing decreases immune activation and augments nitric oxide production in patients with chronic heart failure
Authors: Rubaj Andrzej , Ruciński Piotr , Rejdak Konrad , Oleszczak Krzysztof , Duma Dariusz , Grieb Paweł , Kutarski Andrzej 
Published: February 2006

AbstractIntroductionImmune system activation and oxidative stress are involved in the pathogenesis of heart failure (HF). We aimed to test the hypothesis that upgrading from right ventricular pacing (RVp) to biventricular pacing (BiVp) can counteract these phenomena.Methods28 HF patients, with BiVp were switched to RVp for one week, and then returned to BiVp. Immediately prior to, and 48 h after the return to BiVp, left ventricular (LV) systolic function was evaluated by echocardiography, and serum N‐terminal pro‐brain natriuretic peptide (NTproBNP), C‐reactive protein (CRP), tumor necrosis factor alpha (TNF‐α), interleukin 6 (IL6), nitric oxide metabolites (NOx) and malondialdehyde (MDA) were assayed.ResultsLV systolic function significantly improved 48 h after switching from RVp to BiVp: Ao‐VTI (p < 0.001), SV (p < 0.001) and CO (p < 0.001), and mitral regurgitation significantly decreased (p = 0.003). At the same time, indices of peripheral immune activation decreased: TNF‐α (p = 0.02) and IL6 (p < 0.001). MDA decreased (p < 0.001), whereas NOx increased (p = 0.04). NTproBNP and CRP did not change. In addition, in “responders” (i.e. CO increase > 10% during BiVp vs. RVp) NTproBNP decreased and NOx increased. However, during BiVp, the decreases in TNF‐α, IL6, and MDA occurred both in responders and in non‐responders and were accompanied by a reduction in mitral regurgitation.ConclusionThe beneficial effect of BiVp compared to RVp extends beyond improving cardiac haemodynamics and comprises a decrease in immune activation accompanied by an increase in serum NOx and decrease in serum MDA.
Localization of SP‐ and CGRP‐immunopositive nerve fibers in the hip joint of patients with painful osteoarthritis and of patients with painless failed total hip arthroplasties
Authors: Saxler Guido , Löer Franz , Skumavc Marc , Pförtner Jörg , Hanesch Ulrike 
Published: February 2006

AbstractUsing immunohistochemical methods we determined the presence of SP‐ and CGRP‐immunopositive nerve fibers in the hip joint of patients with femoral neck fracture (controls, group 1), painful osteoarthritis (group 2), and painless failed total hip arthroplasties (group 3). Immunoreactive nerve fibers were found in the soft tissue of the fossa acetabuli as well as in the subintimal part of the synovial layer in the hip joint capsule of groups 1 and 2. In the capsule of controls the innervation density had a median of 5.7 fibers/cm2 for CGRP‐ir and 3.2 fibers/cm2 for SP‐ir afferents. In the osteoarthritic group, the density significantly increased to a median of 15.6 fibers/cm2 for CGRP‐ir and 8.2 fibers/cm2 for SP‐ir neurons (p = 0.05). Patients with failed hip arthroplasties completely lacked these neuropeptide containing afferents. Innervation density in the fossa acetabuli of osteoarthritc patients showed a median of 14.1 fibers/cm2 for CGRP‐ir and 5.9 fibers/cm2 for SP‐ir afferents. From these data we assume that the hip joint capsule and the soft tissue of the fossa acetabuli are important triggers of nociception. This is supported by the fact, that patients with loosened total hip arthroplasties, where we failed to detect SP‐ and CGRP‐immunoreactive fibers, did not feel pain.The upregulation of SP‐ and CGRP‐positive neurons in response to arthritic stages suggests a mechanism involving neuropeptides in the maintenance of a painful degenerative joint disease and in mediating noxious stimuli from the periphery. Furthermore, these findings help to explain clinical observations, such as effectiveness of local therapy to control hip pain with intraarticular injection, synovectomy and denervation procedures.
In situ tagging of deep-sea redfish: application of an underwater, fish-tagging system
Authors: Sigurdsson Thorsteinn , Thorsteinsson Vilhjalmur , Gústafsson Leifur 
Published: February 2006

Abstract
We describe a tagging method using underwater-tagging equipment (UTE), developed in collaboration between the Icelandic Marine Research Institute and the marine-device manufacturer STAR–ODDI. The tagging device can be attached to a pelagic or demersal trawl, immediately in front of the codend. Fish that enter the trawl are guided through the UTE, where they enter a tagging chamber to be held, tagged, and then released. The tagging equipment is electronically controlled from the vessel by a computer with a hard-wire, sonar cable link between the ship and the device. The same cable carries signals from four video cameras in the UTE, and a researcher can view images of the fish on a computer screen and control the tagging equipment simultaneously. The motivation for this project is the need to be able to tag fish, in situ, underwater, so avoiding the problem of swimbladder expansion that for physoclists such as redfish precludes conventional tagging. The UTE has been used to tag redfish in the size range 32–52 cm. Other species, such as saithe, have also entered the equipment and have been tagged with success. The tagging equipment could therefore be an alternative for tagging any medium-size roundfish, such as cod, haddock, and saithe, as well as many deep-sea species in their natural environment without subjecting them to the hazardous journey from deep water to the surface. In all, 752 redfish were tagged with the UTE in 2003 and 2004. Of these, 29 (3.9%) have been recaptured, most with reliable information on date, position, and condition at the time of capture. The tags used in 2003 and 2004 were dummy tags identical in size and shape to the external housings of electronic data-storage tags. In 2005, real DSTs were used of the type DST-micro from STAR–ODDI. These will in future provide time-series of ambient temperature and depth.
Walleye pollock respond to trawling vessels
Authors: De Robertis Alex , Wilson Christopher D. 
Published: February 2006

Abstract
The potential for fish to avoid survey vessels is a major source of uncertainty in stock-assessment surveys. Although walleye pollock (Theragra chalcogramma) are the subject of a substantial commercial fishery in the North Pacific, their behavioural responses to approaching survey vessels remain poorly understood. As a first step in an effort to determine if walleye pollock avoid survey vessels engaged in trawling operations, we made pairwise comparisons of acoustic backscatter recorded by survey vessels while free-running and while trawling. Results are presented of acoustic backscatter recorded from NOAA's RV “Miller Freeman”, which used a midwater trawl during the 1996–2002 eastern Bering Sea surveys, and a chartered commercial fishing vessel, which used a bottom trawl during a survey in 2003 in the Gulf of Alaska. In both cases, average backscatter from a vessel-mounted echosounder was significantly higher when free-running than when trawling. These decreases in backscatter are consistent with increased vessel avoidance while trawling. There were no differences in the vertical distribution of backscatter when free-running and trawling, indicating that pollock do not exhibit elevated diving responses when approached by a trawling vessel rather than by a free-running vessel. Although the study indicates that pollock respond to trawling vessels, the nature of the behavioural response cannot be determined with the methods used in this study. Future work should evaluate potential stimuli produced by trawlers to which pollock may react, and should document changes in behaviour that may occur in their presence.
Preliminary information on cod and haddock production in submerged cages off the coast of New Hampshire, USA
Authors: Chambers Michael D. , Howell William H. 
Published: February 2006

Abstract
The University of New Hampshire's Open Ocean Aquaculture project is intended to evaluate the potential development of offshore aquaculture in the northeastern United States. As part of this project, both cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) were raised in submerged cages at an exposed location 14 km off the coast of New Hampshire, USA. In September 2003, at a mean weight of 45 g, 30 000 cod were transferred offshore into a 200-m3 nursery net located inside a 3000-m3 cage submerged 12 m below the surface. Cod were later released into the main cage at a mean weight of 90 g and are intended to be grown to a market size of 2–3 kg. As of February 2005, the cod averaged 652 g, had a 92% survival rate, an FCR of 1.49, and an SGR of 0.49% d−1. Haddock research was initiated in mid-September 2002, when 3000 haddock (16 g mean weight) were transferred to a 35-m3 inshore nursery pen. By mid-December 2002, their mean weight had increased to 78 g, and the fish were transferred to an offshore cage. As of February 2005, the haddock had a survival rate of 92%, mean weight of 1360 g, FCR of 2.36, and SGR of 0.35% d−1.
Continuous light delays sexual maturation and increases growth of Atlantic cod (Gadus morhua L.) in sea cages
Authors: Taranger G.L. , Aardal L. , Hansen T. , Kjesbu O.S. 
Published: February 2006

Abstract
Prevention of early sexual maturation is essential in Atlantic cod (Gadus morhua) farming because maturity results in reduced growth, affects flesh quality, and may lead to increased mortality. In farmed cod, almost 100% of the fish mature at two years of age and often at a size of 1.5–2 kg. Two pilot experiments were conducted with cod in sea cages at a commercial fish farm in western Norway (60°N) to test the effect of additional continuous light (LL) on the timing of sexual maturation and somatic growth compared with controls under natural light (NL). In the NL groups, 100% maturation was indicated during the natural spawning period from February to April at the age of two years. By contrast, LL treatment from 27 June (15-month-old cod) or 2 September (18-month-old cod) onwards delayed gonad development by three to five months, reduced reproductive investment, and enhanced winter growth compared with the controls. Fish held at NL decreased in body weight during the spawning season (February–April), whereas LL-exposed fish appeared to continue to grow during their spawning season (May–August). LL-treated cod reached mean body weights of 2.90–3.13 kg within 28 months of hatching, whereas the controls reached 2.20–2.42 kg during the same period.