bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐shot quantitative perfusion imaging of the human lung
Authors: Pracht Eberhard D. , Fischer André , Arnold Johannes F.T. , Kotas Markus , Flentje Michael , Jakob Peter M. 
Published: November 2006

AbstractThe major drawback to quantitative perfusion imaging using arterial spin labeling (ASL) techniques is the need to acquire two images (tag and control), which must be subtracted in order to obtain a perfusion‐weighted image. This can potentially result in misregistration artifacts, especially in lung imaging, due to varying lung inflation levels in different breath‐holds. In this work a double inversion recovery (DIR) imaging technique that yields perfusion‐weighted images of the human lung in a single shot is presented. This technique ensures the complete suppression of background tissue while it preserves signal from the blood. Furthermore, the perfusion‐weighted images and an additional (independent) acquired reference scan can be used to obtain quantitative perfusion information from the lungs. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Theory of differential equations in discontinuous piecewise‐defined functions
Authors: Herrera I. 
Published: November 2006

AbstractA truly general and systematic theory of finite element methods (FEM) should be formulated using, as trial and test functions, piecewise‐defined functions that can be fully discontinuous across the internal boundary, which separates the elements from each other. Some of the most relevant work addressing such formulations is contained in the literature on discontinuous Galerkin (dG) methods and on Trefftz methods. However, the formulations of partial differential equations in discontinuous functions used in both of those fields are indirect approaches, which are based on the use of Lagrange multipliers and mixed methods, in the case of dG methods, and the frame, in the case of Trefftz method. This article addresses this problem from a different point of view and proposes a theory, formulated in discontinuous piecewise‐defined functions, which is direct and systematic, and furthermore it avoids the use of Lagrange multipliers or a frame, while mixed methods are incorporated as particular cases of more general results implied by the theory. When boundary value problems are formulated in discontinuous functions, well‐posed problems are boundary value problems with prescribed jumps (BVPJ), in which the boundary conditions are complemented by suitable jump conditions to be satisfied across the internal boundary of the domain‐partition. One result that is presented in this article shows that for elliptic equations of order 2m, with m ≥ 1, the problem of establishing conditions for existence of solution for the BVPJ reduces to that of the “standard boundary value problem,” without jumps, which has been extensively studied. Actually, this result is an illustration of a more general one that shows that the same happens for any differential equation, or system of such equations that is linear, independently of its type and with possibly discontinuous coefficients. This generality is achieved by means of an algebraic framework previously developed by the author and his collaborators. A fundamental ingredient of this algebraic formulation is a kind of Green's formulas that simplify many problems (some times referred to as Green‐Herrera formulas). An important practical implication of our approach is worth mentioning: “avoiding the introduction of the Lagrange multipliers, or the ‘frame’ in the case of Trefftz‐methods, significantly reduces the number of degrees of freedom to be dealt with.” © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007
Instantaneous rate constants in physical organic chemistry: application to acyl transfer reactions of p‐nitrophenyl acetate to hydroxide ion
Authors: Parker Vernon D. 
Published: November 2006

AbstractThe instantaneous rate constant (IRC)–time profiles for single‐step mechanisms are straight lines with zero slope. The IRC–time profiles for reactions taking place in more than a single step depend upon whether decay of reactant or evolution of product concentration is monitored. When reactant decay is monitored, the IRC–time plot extrapolated to zero time is equal to the rate constant for the initial step (kf) in the reaction while the IRC–time profile for product evolution extrapolates to zero at t = 0. The IRC–time profiles for monitoring reactant decay and product evolution converge to a plateau value which can be equated to the rate constant under steady‐state conditions (ks.s). Two independent procedures for calculating IRC–time profiles were developed and tested for both simple and complex mechanisms. The first method is initiated with a least squares correlation over the first 11 points of a 2000‐point ln(1−ER)−time profile (ER designates extent of reaction). The IRC at the midpoint (IRC(6)) of the time interval is assigned the value of −S (where S is the slope of the correlation). The second correlation is over points 2–12 and provides a value of IRC(7). This procedure is continued until IRC(6) to IRC(1995) have been generated. The second method involves a 5th order polynomial smooth of the (1−ER)/time profile before calculating IRC at the midpoints between successive points. The limitations of the two IRC procedures are discussed. The IRC procedures are applied to experimental absorbance–time profiles for the acyl transfer reactions of p‐nitrophenyl acetate to hydroxide ion in water and in aqueous acetonitrile. In water, no significant deviations from pseudo first‐order kinetics were observed. A dramatic change in IRC/time profiles was observed on changing solvents to aqueous acetonitrile. Under the latter conditions the IRC analyses were observed to be consistent with a 2‐step mechanism. Copyright © 2006 John Wiley & Sons, Ltd.
In Vitro effect of D‐004, a lipid extract of the ground fruits of the cuban royal palm (Roystonea regia), on rat microsomal lipid peroxidation
Authors: Menéndez Roberto , Más Rosa , Pérez Yohani , González R. M. 
Published: November 2006

AbstractD‐004 is a lipid extract of the fruits of the Cuban royal palm (Roystonea regia) containing a mixture of saturated fatty acids. D‐004 inhibits prostate hyperplasia (PH) induced with testosterone, in rodents. Since fatty acids inhibit lipid peroxidation (LP), this study investigated whether D‐004 prevents in vitro LP. D‐004 (0.9–1000 µg/mL) markedly and dose‐dependently inhibited in vitro iron‐induced LP in native brain and liver microsomes. D‐004 showed hydroxyl radical scavenging activity, which could explain partially its antioxidant effect on microsomal iron‐induced LP, but it was unable to scavenge superoxide and ABTS radicals, indicating a limited radical scavenging activity. Also, D‐004 inhibited CCl4‐mediated LP in active liver microsomes through a decreased generation of radical species rather than a radical trapping action on CCl4‐derived radical species. D‐004 also inhibited lipooxygenase (LOX) and cyclooxygenase (COX) activities, and the generation of protein‐associated carbonyl groups after LP. Since increased oxidative stress has been linked to PH, the antioxidant effect of D‐004 shown here could contribute to explaining its beneficial effects on T‐induced PH in rodents. Nevertheless, this study shows only in vitro results. Further studies should investigate whether D‐004 also exhibits antioxidant effects in vivo. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of the surface energetics of surface modified calcium carbonate using inverse gas chromatography
Authors: Calhoun Allison , Chiang Ethan 
Published: November 2006

AbstractStearic acid and several silane surface coating agents, including propyltriethoxysilane, aminopropyltriethoxysilane, and diphenyldimethoxysilane, were applied to uncoated calcium carbonate samples at coating levels ranging from 0 to 2.0% by weight. The surface energy of these coated calcium carbonate samples, as determined by inverse gas chromatography, decreased relative to that of the native mineral with increasing coating level for both the stearic acid and the diphenyldimethoxysilane. This decrease in energy arises from the nonpolar functionality of the coating masking the high energy surface of the mineral. The propyltriethoxysilane generated a decreasing surface energy with increase in coating level up to a theoretical monolayer coating. Above this coating level, an inverted bilayer formed that increased the surface energy of the mineral. Aminopropyltriethoxysilane caused an initial decrease in surface energy relative to that of the native mineral but then retained an approximately constant surface energy at all coating levels. This observation arises from the energetic groups presented at the surface of the mineral regardless of the orientation of the silane. J. VINYL ADDIT. TECHNOL., 12:174–182, 2006. © 2006 Society of Plastics Engineers
Pentaphenyl‐1,3,2‐dioxaphospholane as a reactive flame retardant
Authors: Howell Bob A. , Uzibor Joel 
Published: November 2006

Abstract2,4,4,5,5‐Pentaphenyl‐1,3,2‐dioxaphospholane may be generated by treating benzpinacol with (dichloro)phenylphosphine. The phospholane contains a strained carbon–carbon bond which undergoes thermally‐induced homolysis at 70°C to generate a diradical capable of initiating styrene polymerization. The polymer generated from decomposition of the phospholane in the presence of styrene monomer contains phosphorus in the mainchain. This polymer exhibits thermal stability comparable to that of conventional polystyrene but decreased flammability. J. VINYL ADDIT. TECHNOL., 12:192–197, 2006. © 2006 Society of Plastics Engineers
Expression of active Akt protects against tamoxifen‐induced apoptosis in MCF‐7 Cells
Authors: Shin Incheol , Arteaga Carlos L. 
Published: November 2006

AbstractWe investigated the effect of constitutive active Akt expression on anti‐proliferative and apoptotic effect of tamoxifen in MCF‐7 human breast cancer cells. Forced expression of AktDD (T308D, S473D) resulted in increased phosphorylation of GSK3β, a physiological substrate of Akt. When estrogen receptor (ER) mediated transcription was determined by luciferase assays, there was more than 2‐fold increase in estradiol‐dependent transcription in MCF‐7 cells overexpressing AktDD (MCF‐7 AktDD) compared to vector control cells (MCF‐7 vec). MCF‐7 AktDD cells showed increased proliferation in a medium containing charcoal stripped serum supplemented with estradiol. When the cell cycle profiles were examined, there was an increase in S‐phase and a reduction in G1 phase in MCF‐7 AktDD cells as compared to MCF‐7 vec cells. Overexpression of AktDD also attenuated tamoxifen‐mediated apoptosis. These results suggest that Akt could confer resistance to anti‐estrogen mediated cell death and inhibition of proliferation.
iubmb Life, 58: 664 ‐ 669, 2006
Temporal Parts and Timeless Parthood
Authors: Olson Eric T. 
Published: November 2006

AbstractWhat is a temporal part? Most accounts explain it in terms of timeless parthood: a thing's having a part without temporal qualification. Some find this hard to understand, and thus find the view that persisting things have temporal parts—four‐dimensionalism—unintelligible. T. Sider offers to help by defining temporal parthood in terms of a thing's having a part at a time. I argue that no such account can capture the notion of a temporal part that figures in orthodox four‐dimensionalism: temporal parts must be timeless parts. This enables us to state four‐dimensionalism more clearly.
Exchange Rate Regimes and Reforms: A Panel Analysis for the World versus OECD Countries*
Authors: Belke Ansgar , Herz Bernhard , Vogel Lukas 
Published: November 2006

AbstractThis paper examines the contemporaneous relationship between the exchange rate regime and structural economic reforms over a period of 30 years. Using panel data techniques, we look at both a broad ‘world sample’ and an OECD country sample. We investigate empirically whether structural reforms have complemented or substituted for monetary commitment in the attempt to improve macroeconomic performance. Our results suggest that, on average, an exchange rate rule positively correlates with the amount of overall structural reforms and of trade liberalization in particular. However, we do not find a significant and robust impact of exchange rate commitment on labour and product market reform. The results are similar for both the wider, more heterogeneous world sample and the panel of OECD economies. They contradict the hypothesis that exchange rate commitments may have slowed the pace of structural reform, but neither provides robust evidence that losing the possibility of an exchange rate adjustment promotes labour and product market reforms.
Efficient assay for evaluating human thrombopoiesis using NOD/SCID mice transplanted with cord blood CD34+ cells
Authors: Suzuki Ken‐ichi , Hiramatsu Hidefumi , Fukushima‐Shintani Mari , Heike Toshio , Nakahata Tatsutoshi 
Published: November 2006

AbstractA suitable model for the preclinical study of human platelet production in vivo has not been available. NOD/SCID mice were characterized as representing an efficient engraftment model for human hematopoietic stem cells, which resulted in the production of human platelets. Here, we evaluated in vivo human thrombopoiesis and ex vivo human platelet functions in NOD/SCID mice transplanted with human cord blood (CB) CD34+ cells. Human platelets and human CD45+ cells appeared in peripheral blood of NOD/SCID mice from 4 wk after transplantation. Human platelets produced in these mice showed CD62P expression and the activation of GPIIb/IIIa on human platelets on stimulation with an agonist. PEG‐rHuMGDF (0, 0.5 and 5 μg/kg/d s.c.) was injected for 14 d into mice that had been confirmed to produce human platelets stably. The number of human platelets increased about twofold at 0.5 μg/kg/d and about fivefold at 5 μg/kg/d after 14 d. Withdrawal of PEG‐rHuMGDF administration caused the human platelet count to return to the pretreatment level. Further, re‐administration of PEG‐rHuMGDF induced a similar human thrombopoietic response as it did on initial administration. These results suggest that NOD/SCID mice engrafted with human CB CD34+ cells will be useful for the study of human platelet production in vivo.
Does an immunochromatographic D‐dimer exclude acute lower limb deep venous thrombosis?
Authors: Subramaniam Rathan M , Heath Rebekah , Cox Kim , Chou Tina , Stewart Joanna , Sleigh Jamie 
Published: November 2006

AbstractBackground:  A pre‐test probability score and D‐dimer may reduce the need for ultrasound examinations for excluding lower limb deep venous thrombosis (DVT).Objective:  To establish the accuracy of an immunochromatographic D‐dimer assay called ‘Simplify’ for diagnosis of acute DVT by complete (calf veins included) lower limb ultrasound examination.Methods:  A total of 453 consecutive patients presented to the ED of a tertiary centre with suspected first episode of DVT, were prospectively recruited. A pre‐test probability score (Hamilton Score), an immunochromatographic D‐dimer and a complete, single, unilateral lower limb ultrasound examination were performed in all patients. All patients with a negative ultrasound examination were followed up for 3 months.Results:  There were 159 men and 294 women with a mean age of 55.8 years (SD 20.3). Of the 227 patients with a negative D‐dimer, 214 patients had negative ultrasound examinations and 13 patients had isolated calf DVT. Among the 226 patients with a positive D‐dimer, 74 patients had DVT and 152 patients had negative ultrasound examinations. The sensitivity, specificity, positive and negative predictive values were 85.1% (75.8–91.8), 58.5% (53.4–63.5), 32.7% (26.6–38.9) and 94.3% (90.4–96.9), respectively. One hundred and sixty‐five patients had an unlikely Hamilton Score and a negative D‐dimer. The negative predictive value of the immunochromatographic D‐dimer in an unlikely Hamilton Score population was 98.8% (95.7–99.8%).Conclusion:  An unlikely probability Hamilton Score and a negative immunochromatographic D‐dimer reliably exclude both proximal and isolated calf DVT.
Patients Responding to Phosphodiesterase Type 5 Inhibitor Therapy—What Do Their Sexual Partners Know?
Authors: Klotz Theodor , Mathers Mike , Klotz Rosemarie , Sommer Frank 
Published: November 2006

ABSTRACT

Introduction
Phosphodiesterase type 5 (PDE5) inhibitors are an efficacious therapy in men with erectile dysfunction (ED). There are only a few studies that also focus on the participating couples during PDE5 inhibitor therapy.

Aim
To determine to what extent patients personally informed their sexual partners about their ongoing PDE5 inhibitor therapy.

Main Outcome Measures
Likelihood of informing the female partner by the patient himself about the use of PDE5 inhibitors.

Methods
A total of 216 men (mean age 62.3 years) with ED were successfully treated with PDE5 inhibitors in three independent centers. After an interval of at least 3 months of successful ED therapy, all patients were asked by questionnaire whether their sexual partners were informed of their PDE5 inhibitor therapy.

Results
Eighty-two percent of the patients were exclusively involved in one stable sexual relationship, 9.7% of the men admitted to having changing sexual partners, and 6% did not give any information at all about their sexual partners. Twenty percent of the men had a severe ED (International Index of Erectile Function [IIEF-5] &lt;11). Forty-nine percent showed a moderate ED (IIEF-5 11–16) and 31% suffered a mild ED (IIEF-5 &gt;16). PDE5 inhibitor medication was used 1.2 times/month by men with a severe ED, 2.1 times/month by patients with a moderate ED, and 2.9 times/month by men with a mild ED. Forty-one (93%) of the 44 patients with a severe ED informed their sexual partners that they were taking PDE5 inhibitors. In the patient group with moderate ED, 49 (47%) of 105 patients and only 14 (21%) of 67 of the patients with mild ED shared this information with their partners.

Conclusion
Less than 40% of the patients suffering a moderate or mild ED using PDE5 inhibitors shared this information with their partners. It seems that patients find ED so disturbing that many patients do not inform their partners of PDE5 inhibitor use.
Genetic Diversity of Norovirus among Children with Gastroenteritis in São Paulo State, Brazil
Authors: Castilho Juliana Galera , Munford Veridiana , Resque Hugo Reis , Fagundes-Neto Ulysses , Vinjé Jan , Rácz Maria Lúcia 
Published: November 2006

ABSTRACT
Norovirus (NoV) is one of the most common causes of acute gastroenteritis in children and adults. To study the prevalence and genetic variability of NoV in children with acute gastroenteritis in São Paulo State, Brazil, we examined 234 stool samples from children with or without gastroenteritis during a 5-year period (1995 to 1999). NoV RNA was detected by reverse transcription-PCR and confirmed by DNA sequence analysis. We used two different oligonucleotide primer sets targeting the 3′ end of the RNA polymerase gene (region B), as well a partial capsid region at the 3′ end of the VP1 gene (region D). A total of 78 (33.3%) of the samples tested positive for NoV, and in region B, of the 66 strains sequenced, 4 (6.1%) belonged to GI, 52 (78.7%) belonged to GII, and five samples (7.6%) contained a mixture of the GI and GII genotypes. Phylogenetic analysis showed that the majority (40 of 66 [60.6%]) of the strains belonged to genotype GII.4. The nucleotide sequence identity of three strains was lower than 77.9% compared to a region B reference sequence database but showed 85.3 to 88.8% identity with GII.2 Melksham strain in region D, indicating the circulation of a possible recombinant NoV strain. One sample (GII.3) was sequenced only in region D. In conclusion, we have a total of 67 sequenced strains. This is the first report that describes the predominance of GII.4 NoV strains in children visiting the ambulatory of different hospitals in São Paulo State, Brazil, and we show that mixtures of different strains can be found in individual samples, including some possible new recombinant strains.
Detection of
Aspergillus
DNA in Cerebrospinal Fluid from Patients with Cerebral Aspergillosis by a Nested PCR Assay
Authors: Hummel M. , Spiess B. , Kentouche K. , Niggemann S. , Böhm C. , Reuter S. , Kiehl M. , Mörz H. , Hehlmann R. , Buchheidt D. 
Published: November 2006

ABSTRACT

Invasive aspergillosis (IA), a complication with high mortality rates, especially in disseminated IA with cerebral involvement, is difficult to diagnose. Biopsy of cerebral lesions is often not feasible, and culture of
Aspergillus
spp. from cerebrospinal fluid (CSF) is frequently negative. New molecular methods have emerged for diagnosing IA. So far, there are only few reports of
Aspergillus
DNA detection in CSF. After modifying the DNA extraction protocol, we detected
Aspergillus
DNA in CSF samples by a previously described nested PCR assay. In six patients with hematologic malignancy and cerebral aspergillosis, CSF samples were investigated for
Aspergillus
DNA. IA was classified according to the EORTC/MSG 2002 criteria. Two patients each had proven, probable, and possible IA. Thirty-five CSF samples were investigated for
Aspergillus
DNA by nested PCR. Samples with positive results in the nested PCR assay were quantified by LightCycler PCR assay. Fourteen CSF samples showed positive results in the nested PCR assay. Of these, six samples gave positive results in real-time PCR. The range of CFU per ml was 2,154 to 63,100,000. The highest number of CFU per ml was found in a CSF sample of a patient with acute lymphocytic leukemia and probable cerebral aspergillosis. Detection of
Aspergillus
DNA in CSF samples is thus possible and has the potential to improve diagnosis of cerebral aspergillosis. Further prospective studies with larger numbers of patients must be performed to evaluate the clinical significance of
Aspergillus
PCR with CSF samples.
Crimean-Congo Hemorrhagic Fever Virus: Genetic Analysis and Tick Survey in Turkey
Authors: Tonbak Sukru , Aktas Munir , Altay Kursat , Azkur Ahmet K. , Kalkan Ahmet , Bolat Yusuf , Dumanli Nazir , Ozdarendeli Aykut 
Published: November 2006

ABSTRACT

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus in the family
Bunyaviridae
, genus
Nairovirus
. The virus is transmitted to humans through infected tick bites or from direct contact with viremic animals or humans. In the present study, a total of 1,015 adult ticks were collected from cattle (603 specimens), sheep (17 specimens), and goats (395 specimens) in the Kelkit Valley in Turkey. Four tick species were recognized on the animals in the surveyed region. The most abundant species were
Rhipicephalus bursa
and
Hyalomma marginatum marginatum
, at 47.68% (484/1,015) and 46.40% (471/1,015), respectively. Reverse transcriptase PCR was used to recover partial sequences of the CCHFV small (S) genome segment. The presence of CCHFV was determined in 3 of 33 (9.09%)
R. bursa
pools and in 1 of 31 (3.22%)
H. m. marginatum
pools. Virus sequences from
R. bursa
were extremely different from those of the Greek CCHFV strain (U04958) isolated from an
R. bursa
tick. Phylogenetic analysis indicated that the CCHFV isolates obtained in this study clustered in group 5, whose range encompasses southwestern Russian and Kosovo. This is the first evidence of CCHFV in ticks from Turkey. Even though
Hyalomma
is the main vector for CCHFV,
R. bursa
may play a role in CCHFV transmission.