286 research outputs found
Occurrence and Sources of Triterpenoid Methyl Ethers and Acetates in Sediments of the Cross-River System, Southeast Nigeria
Pentacyclic triterpenol methyl ethers (PTMEs), germanicol methyl ether (miliacin), 3-methoxyfern-9(11)-ene (arundoin), β-amyrin methyl ether (iso-sawamilletin), and 3-methoxytaraxer-14-ene (sawamilletin or crusgallin) were characterized in surface sediments of the Cross-River system using gas chromatography-mass spectrometry (GC-MS). Triterpenol esters (mainly ι- and β-amyrinyl acetates and hexanoates, and lupeyl acetate and hexanoate) were also found. These distinct compounds are useful for assessing diagenesis that can occur during river transport of organic detritus. Poaceae, mainly Gramineae and Elaeis guineensis higher plant species, are proposed as primary sources for the PTMEs and esters in the sediments. PTMEs are biomarkers of specific higher plant subspecies, while the triterpenol esters are indicators of early diagenetic alteration of higher plant detritus
Altered gene expression in human placenta after suspected preterm labour
Introduction Suspected preterm labour occurs in around 9% of pregnancies. However, almost two-thirds of women admitted for threatened preterm labour ultimately deliver at term and are considered risk-free for fetal development. Methods We examined placental and umbilical cord blood samples from preterm or term deliveries after threatened preterm labour as well as term deliveries without threatened preterm labour. We quantitatively analysed the mRNA expression of inflammatory markers (IL6, IFN?, and TNFa) and modulators of angiogenesis (FGF2, PGF, VEGFA, VEGFB, and VEGFR1). Results A total of 132 deliveries were analysed. Preterm delivery and term delivery after suspected preterm labour groups showed similar increases in TNFa expression compared with the term delivery control group in umbilical cord blood samples. Placental samples from preterm and term deliveries after suspected preterm labour exhibited significantly increased expression of TNFa and IL6 and decreased expression of IFN?. Suspected preterm labour was also associated with altered expression of angiogenic factors, although not all differences reached statistical significance. Discussion We found gene expression patterns indicative of inflammation in human placentas after suspected preterm labour regardless of whether the deliveries occurred preterm or at term. Similarly, a trend towards altered expression of angiogeneic factors was not limited to preterm birth. These findings suggest that the biological mechanisms underlying threatened preterm labour affect pregnancies independently of gestational age at birth
Differential subordination and superordination studies involving symmetric functions using a q-analogue multiplier operator
The present investigation focus on applying the theories of differential subordination, differential superordination and related sandwich-type results for the study of some subclasses of symmetric functions connected through a linear extended multiplier operator, which was previously defined by involving the -Choi-Saigo-Srivastava operator. The aim of the paper is to define a new class of analytic functions using the aforementioned linear extended multiplier operator and to obtain sharp differential subordinations and superordinations using functions from the new class. Certain subclasses are highlighted by specializing the parameters involved in the class definition, and corollaries are obtained as implementations of those new results using particular values for the parameters of the new subclasses. In order to show how the results apply to the functions from the recently introduced subclasses, numerical examples are also provided
Study protocol for a randomised controlled trial: Treatment of early intrauterine growth restriction with low molecular weight heparin (TRACIP)
Introduction The incidence of intrauterine growth restriction (IUGR) is estimated at about 3% of pregnancies, and it is associated with 30% of all perinatal mortality and severe morbidity with adverse neurodevelopmental and cardiovascular health consequences in adult life. Early onset IUGR represents 20%-30% of all cases and is highly associated with severe placental insufficiency. The existing evidence suggests that low molecular weight heparin (LMWH) has effects beyond its antithrombotic action, improving placental microvessel structure and function of pregnant women with vascular obstetric complications by normalising proangiogenic and antiapoptotic protein levels, cytokines and inflammatory factors. The objective of our study is to demonstrate the effectiveness of LMWH in prolonging gestation in pregnancies with early-onset IUGR. Methods and analysis This is a multicentre, triple-blind, parallel-arm randomised clinical trial. Singleton pregnancies qualifying for early (20-32 weeks at diagnosis) placental IUGR (according to Delphi criteria) will be randomised to subcutaneous treatment with bemiparin 3500 IU/0.2 mL/day or placebo from inclusion at diagnosis to the time of delivery. Analyses will be based on originally assigned groups (intention-to-treat). The primary objective will be analysed by comparing gestational age and prolongation of pregnancy (days) in each group with Student''s t-tests for independent samples and by comparing Kaplan-Maier survival curves (from inclusion to delivery, log-rank test). A linear regression model for gestational age at birth will consider the following covariates: Gestational age at inclusion (continuous) and pre-eclampsia (binary). Ethics and dissemination The study will be conducted in accordance with the principles of Good Clinical Practice. This study was approved by the Clinical Research Ethics Committee (CEIC) of Sant Joan de DĂŠu Hospital, on 13 July 2017. The trial is registered in the public registry www.clinicaltrial.gov. according to Science Law 14/2011, and the results will be published in an open access journal
The assessment of thermal and radiation stability of UHMWPE
Preirradiated ultrahigh molecular weight polyethylene (UHMWPE) was subjected to other cycle of Îł-exposure in order to explain the behavior of this material after radiation processing. The oxygen uptake investigation was selected for the characterization of thermal stability of multisession irradiation. The long life radicals promote crosslinking or oxidative degradation depending on the second irradiation dose and on the environmental conditions. The main kinetic parameters: oxidation period and oxidation rate were evaluated depicting the availability of radiochemical processing of UHMWPE for further long term applications. Irradiation of UHMWPE in salt solution reveals the improvement in the thermal strength for low exposure doses
Applications of fuzzy differential subordination theory on analytic p-valent functions connected with -calculus operator
In recent years, the concept of fuzzy set has been incorporated into the field of geometric function theory, leading to the evolution of the classical concept of differential subordination into that of fuzzy differential subordination. In this study, certain generalized classes of -valent analytic functions are defined in the context of fuzzy subordination. It is highlighted that for particular functions used in the definitions of those classes, the classes of fuzzy -valent convex and starlike functions are obtained, respectively. The new classes are introduced by using a -calculus operator defined in this investigation using the concept of convolution. Some inclusion results are discussed concerning the newly introduced classes based on the means given by the fuzzy differential subordination theory. Furthermore, connections are shown between the important results of this investigation and earlier ones. The second part of the investigation concerns a new generalized -calculus operator, defined here and having the -Bernardi operator as particular case, applied to the functions belonging to the new classes introduced in this study. Connections between the classes are established through this operator
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Terpenoid Compositions of Resins from Callitris Species (Cupressaceae)
The environmental fate of conifer resins and their natural product compounds as mixtures is of importance for source, alteration, and transport studies. The compound compositions of resins of the common Callitris species (Cupressaceae) based on gas chromatography-mass spectrometry have not been reported. Results show that diterpenoids were the most abundant components and callitrisic acid was present in the resin extracts of all Callitris species analyzed. Significant amounts of 4-epi-pimaric and sandaracopimaric acids, with lesser communic, ozic, and lambertianic acids, were also in the mixtures. Phenolic diterpenoids, for example, ferruginol, hinokiol, were found in trace quantities in some samples. Thus, callitrisic acid and 4-epi-pimaric acid are the characteristic diterpenoids of Callitris species that are amenable to molecular biomarker analyses in geological or environmental applications
Tests of the random phase approximation for transition strengths
We investigate the reliability of transition strengths computed in the
random-phase approximation (RPA), comparing with exact results from
diagonalization in full shell-model spaces. The RPA and
shell-model results are in reasonable agreement for most transitions; however
some very low-lying collective transitions, such as isoscalar quadrupole, are
in serious disagreement. We suggest the failure lies with incomplete
restoration of broken symmetries in the RPA. Furthermore we prove, analytically
and numerically, that standard statements regarding the energy-weighted sum
rule in the RPA do not hold if an exact symmetry is broken.Comment: 11 pages, 7 figures; Appendix added with new proof regarding
violation of energy-weighted sum rul
Clinical impact of Doppler reference charts on management of smallâforâgestationalâage fetuses: need for standardization
Objective
To assess clinical variability in the management of smallâforâgestationalâage (SGA) fetuses according to different published Doppler reference charts for umbilical artery (UA) and fetal middle cerebral artery (MCA) Doppler indices and cerebroplacental ratio (CPR).
Methods
We performed a systematic search of MEDLINE, EMBASE, CINAHL and the Web of Science databases from 1954 to 2018 for studies with the sole aim of creating fetal Doppler reference values for UA, MCA and CPR. The top cited articles for each Doppler parameter were included. Variability in Doppler values at the following clinically relevant cutâoffs was assessed: UAâpulsatility index (PI)â>â95th percentile; MCAâPI <â5th percentile; and CPR <â5th percentile. Variability was calculated for each week of gestation and expressed as the percentage difference between the highest and lowest Doppler value at the clinically relevant cutâoffs. Simulation analysis was performed in a cohort of SGA fetuses (n â=â617) to evaluate the impact of this variability on clinical management.
Results
From a total of 40 studies that met the inclusion criteria, 19 were analyzed (13 for UAâPI, 10 for MCAâPI and five for CPR). Wide discrepancies in reported Doppler reference values at clinically relevant cutâoffs were found. MCAâPI showed the greatest variability, with differences of up to 51% in the 5th percentile value at term. Variability in the 95th percentile of UAâPI and the 5th percentile of CPR at each gestational week ranged from 21% to 41% and 15% to 33%, respectively. As expected, on simulation analysis, these differences in Doppler cutâoff values were associated with significant variation in the clinical management of SGA fetuses, despite using the same protocol.
Conclusions
The choice of Doppler reference chart can result in significant variation in the clinical management of SGA fetuses, which may lead to suboptimal outcomes and inaccurate research conclusions. Therefore, an attempt to standardize fetal Doppler reference ranges is needed
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