1,026 research outputs found
Phytotoxic activity of Salvia x jamensis.
A study has been carried out on the surface exudate of Salvia x jamensis, which showed a significant phytotoxic activity against Papaver rhoeas L. and Avena sativa L.. Bioguided separation of the exudate yielded active fractions from which 3β-hydroxy-isopimaric acid (1), hautriwaic acid (2), betulinic acid (3), 7,8β-dihydrosalviacoccin (4), isopimaric acid (5), 14α-hydroxy-isopimaric acid (7), 15,16-epoxy-7α,10β-dihydroxy-clerod-3,13(16),14-trien-17,12;18,19-diolide (8), cirsiliol (5,3′,4′-trihydroxy-6,7-dimethoxyflavone, 9) and two new neoclerodane diterpenes (6 and 10) were isolated. The structures of 6 and 10 were identified as 15,16-epoxy-10β-hydroxy-clerod-3,13(16),14-trien-17,12;18,19-diolide and 15,16-epoxy-7α,10-dihydroxy-clerod-2,13(16),14-trien-17,12;18,19-diolide respectively on the basis of spectroscopic data analysis. All compounds, but 7, 8 and 10, were active in inhibiting the germination of the tested species
High prevalence of BRCA1 deletions in BRCAPRO-positive patients with high carrier probability.
Mutation screening of the BRCA1 and BRCA2 genes in probands with familial breast/ovarian cancer has been
greatly improved by the multiplex ligation-dependent probe amplification (MLPA) assay able to evidence gene
rearrangements not detectable by standard screening methods. However, no criteria for selection of cases to
be submitted to the MLPA test have been reported yet. We used the BRCAPro software for the selection of
familial breast/ovarian cancer probands investigated with the MLPA approach after negative BRCA1/2
conventional mutation screening. One hundred and seventy-seven probands were investigated for germline
BRCA1/2 mutations after assessment of genetic risk using BRCAPro. Probands were classified as BRCAPro
positive (n = 67) when the carrier probability (CP) was >10% and as BRCAPro negative (n = 110), when the CP
was <10%. Conventional mutational analyses of the BRCA1/2 genes and, in one case, of p53 identified 22
pathogenetic germline mutations, 12 in BRCA1, 9 in BRCA2 and 1 in p53, in 22/177 (12.4%) probands. All the
mutations except one were detected in BRCAPro-positive patients. In the 46 BRCAPro-positive cases that
resulted negative by BRCA1/2 mutation, screening analysis of rearrangements within BRCA1/2 by MLPA was
carried out. Three patients with a very high CP showed BRCA1 deletions, consisting of deletions of exons 1–2 in
two probands and of exon 24 in the third proband. In one case, the exons 1–2 deletion was shown to
cosegregate with disease in the family. No BRCA2 rearrangements were detected, but one patient showed the
1100delC of the CHEK2 gene, whose probe is present in the BRCA2 kit. In our series, the highest carrier
detection rate of mutation screening plus MLPA analysis (52.3%) was in patients with a BRCAPro CP >50%
Laser writable high-K dielectric for van der Waals nano-electronics
This is the author accepted manuscript. The final version is available from American Association for the Advancement of Science via the DOI in this record.Like silicon-based semiconductor devices, van der Waals heterostructures will require integration with high-K oxides. This is needed to achieve suitable voltage scaling, improved performance as well as allowing for added functionalities. Unfortunately, commonly used high-k oxide deposition methods are not directly compatible with 2D materials. Here we demonstrate a method to embed a multi-functional few nm thick high-k oxide within van der Waals devices without degrading the properties of the neighbouring 2D materials. This is achieved by in-situ laser oxidation of embedded few layer HfS2 crystals. The resultant oxide is found to be in the amorphous phase with a dielectric constant of k~15 and break-down electric fields in the range of 0.5-0.6 V/nm. This transformation allows for the creation of a variety of fundamental nano-electronic and opto-electronic devices including, flexible Schottky barrier field effect transistors, dual gated graphene transistors as well as vertical light emitting and detecting tunnelling transistors. Furthermore, upon dielectric break-down, electrically conductive filaments are formed. This filamentation process can be used to electrically contact encapsulated conductive materials. Careful control of the filamentation process also allows for reversible switching between two resistance states. This allows for the creation of resistive switching random access memories (ReRAMs). We believe that this method of embedding a high-k oxide within complex van der Waals heterostructures could play an important role in future flexible multi-functional van der Waals devices.F.W
acknowledges support from the Royal Academy of Engineering. J.D.M. acknowledges financial support
from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the
EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1). S.R. and M.F.C.
acknowledge financial support from EPSRC (Grant no. EP/K010050/1, EP/M001024/1, EP/M002438/1),
from Royal Society international Exchanges Scheme 2016/R1, from The Leverhulme trust (grant title
“Quantum Revolution” and "Quantum Drums"). A.P Rooney and S.J Haigh acknowledge support from the
EPSRC postdoctoral fellowship and from the European Research Council (ERC) under the European Union’s
Horizon 2020 research and innovation programme (grant agreement ERC-2016-STG-EvoluTEM-715502)
and the Defence Threat Reduction Agency (HDTRA1-12-1-0013). I.A. acknowledges financial support from
The European Commission Marie Curie Individual Fellowships (Grant number 701704)
Multi-membership gene regulation in pathway based microarray analysis
This article is available through the Brunel Open Access Publishing Fund. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Gene expression analysis has been intensively researched for more than a decade. Recently, there has been elevated interest in the integration of microarray data analysis with other types of biological knowledge in a holistic analytical approach. We propose a methodology that can be facilitated for pathway based microarray data analysis, based on the observation that a substantial proportion of genes present in biochemical pathway databases are members of a number of distinct pathways. Our methodology aims towards establishing the state of individual pathways, by identifying those truly affected by the experimental conditions based on the behaviour of such genes. For that purpose it considers all the pathways in which a gene participates and the general census of gene expression per pathway. Results: We utilise hill climbing, simulated annealing and a genetic algorithm to analyse the consistency of the produced results, through the application of fuzzy adjusted rand indexes and hamming distance. All algorithms produce highly consistent genes to pathways allocations, revealing the contribution of genes to pathway functionality, in agreement with current pathway state visualisation techniques, with the simulated annealing search proving slightly superior in terms of efficiency. Conclusions: We show that the expression values of genes, which are members of a number of biochemical pathways or modules, are the net effect of the contribution of each gene to these biochemical processes. We show that by manipulating the pathway and module contribution of such genes to follow underlying trends we can interpret microarray results centred on the behaviour of these genes.The work was sponsored by the studentship scheme of the School of Information Systems, Computing and Mathematics, Brunel Universit
More three-point correlators of giant magnons with finite size
In the framework of the semiclassical approach, we compute the normalized
structure constants in three-point correlation functions, when two of the
vertex operators correspond to heavy string states, while the third vertex
corresponds to a light state. This is done for the case when the heavy string
states are finite-size giant magnons with one or two angular momenta, and for
two different choices of the light state, corresponding to dilaton operator and
primary scalar operator. The relevant operators in the dual gauge theory are
Tr(F_{\mu\nu}^2 Z^j+...) and Tr(Z^j). We first consider the case of AdS_5 x S^5
and N = 4 super Yang-Mills. Then we extend the obtained results to the
gamma-deformed AdS_5 x S^5_\gamma, dual to N = 1 super Yang-Mills theory,
arising as an exactly marginal deformation of N = 4 super Yang-Mills.Comment: 14 pages, no figure
Liquid biopsies in lung cancer: The new ambrosia of researchers
In the last decades the approach to cancer patient management has been deeply revolutionized. We are moving from a "one-fits-all" strategy to the "personalized medicine" based on the molecular characterization of the tumor. In this new era it is becoming more and more clear that the monitoring of the disease is fundamental for the success of the treatment, thus there is the need of new biomarker discovery. More precisely in the last years the scientific community has started to use the term "liquid biopsy". A liquid biopsy is a liquid biomarker that can be easily isolated from many body fluids (blood, saliva, urine, ascites, pleural effusion, etc.) and, as well as a tissue biopsy, a representative of the tissue from which it is spread. In this review we will focus our attention on circulating tumor cells, circulating tumor DNA, exosomes and secretomes with the aim to underlie their usefulness and potential application in a clinical setting for lung cancer patient management
Pregnancy-induced changes in cell-fate in the mammary gland
The protective effect of an early full-term pregnancy is a well established phenomenon; in contrast, the molecular and cell-specific mechanisms that govern parity-specific changes in the mammary gland have not been well described. Recent studies signify a dramatic advance in our understanding of this phenomenon, and indicate a 'cell fate' model for parity-related changes that lead to protection against breast cancer
Why nature matters: A systematic review of intrinsic, instrumental, and relational values
\ua9 2023 The Author(s). Published by Oxford University Press on behalf of the American Institute of Biological Sciences. In this article, we present results from a literature review of intrinsic, instrumental, and relational values of nature conducted for the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, as part of the Methodological Assessment of the Diverse Values and Valuations of Nature. We identify the most frequently recurring meanings in the heterogeneous use of different value types and their association with worldviews and other key concepts. From frequent uses, we determine a core meaning for each value type, which is sufficiently inclusive to serve as an umbrella over different understandings in the literature and specific enough to help highlight its difference from the other types of values. Finally, we discuss convergences, overlapping areas, and fuzzy boundaries between different value types to facilitate dialogue, reduce misunderstandings, and improve the methods for valuation of nature\u27s contributions to people, including ecosystem services, to inform policy and direct future research
Pregnancy-related factors and the risk of breast carcinoma in situ and invasive breast cancer among postmenopausal women in the California Teachers Study cohort
Abstract Introduction Although pregnancy-related factors such as nulliparity and late age at first full-term pregnancy are well-established risk factors for invasive breast cancer, the roles of these factors in the natural history of breast cancer development remain unclear. Methods Among 52,464 postmenopausal women participating in the California Teachers Study (CTS), 624 were diagnosed with breast carcinoma in situ (CIS) and 2,828 with invasive breast cancer between 1995 and 2007. Multivariable Cox proportional hazards regression methods were used to estimate relative risks associated with parity, age at first full-term pregnancy, breastfeeding, nausea or vomiting during pregnancy, and preeclampsia. Results Compared with never-pregnant women, an increasing number of full-term pregnancies was associated with greater risk reduction for both breast CIS and invasive breast cancer (both P trend < 0.01). Women having four or more full-term pregnancies had a 31% lower breast CIS risk (RR = 0.69, 95% CI = 0.51 to 0.93) and 18% lower invasive breast cancer risk (RR = 0.82, 95% CI = 0.72 to 0.94). Parous women whose first full-term pregnancy occurred at age 35 years or later had a 118% greater risk for breast CIS (RR = 2.18, 95% CI = 1.36 to 3.49) and 27% greater risk for invasive breast cancer (RR = 1.27, 95% CI = 0.99 to 1.65) than those whose first full-term pregnancy occurred before age 21 years. Furthermore, parity was negatively associated with the risk of estrogen receptor-positive (ER+) or ER+/progesterone receptor-positive (PR+) while age at first full-term pregnancy was positively associated with the risk of ER+ or ER+/PR+ invasive breast cancer. Neither of these factors was statistically significantly associated with the risk of ER-negative (ER-) or ER-/PR- invasive breast cancer, tests for heterogeneity between subtypes did not reach statistical significance. No clear associations were detected for other pregnancy-related factors. Conclusions These results provide some epidemiologic evidence that parity and age at first full-term pregnancy are involved in the development of breast cancer among postmenopausal women. The role of these factors in risk of in situ versus invasive, and hormone receptor-positive versus -negative breast cancer merits further exploration
Recurrent Modification of a Conserved Cis-Regulatory Element Underlies Fruit Fly Pigmentation Diversity
The development of morphological traits occurs through the collective action of networks of genes connected at the level of gene expression. As any node in a network may be a target of evolutionary change, the recurrent targeting of the same node would indicate that the path of evolution is biased for the relevant trait and network. Although examples of parallel evolution have implicated recurrent modification of the same gene and cis-regulatory element (CRE), little is known about the mutational and molecular paths of parallel CRE evolution. In Drosophila melanogaster fruit flies, the Bric-à-brac (Bab) transcription factors control the development of a suite of sexually dimorphic traits on the posterior abdomen. Female-specific Bab expression is regulated by the dimorphic element, a CRE that possesses direct inputs from body plan (ABD-B) and sex-determination (DSX) transcription factors. Here, we find that the recurrent evolutionary modification of this CRE underlies both intraspecific and interspecific variation in female pigmentation in the melanogaster species group. By reconstructing the sequence and regulatory activity of the ancestral Drosophila melanogaster dimorphic element, we demonstrate that a handful of mutations were sufficient to create independent CRE alleles with differing activities. Moreover, intraspecific and interspecific dimorphic element evolution proceeded with little to no alterations to the known body plan and sex-determination regulatory linkages. Collectively, our findings represent an example where the paths of evolution appear biased to a specific CRE, and drastic changes in function were accompanied by deep conservation of key regulatory linkages. © 2013 Rogers et al
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