577 research outputs found
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Elucidating the role of shikimate dehydrogenase in controlling the production of anthocyanins and hydrolysable tannins in the outer peels of pomegranate.
BACKGROUND:The outer peels of pomegranate (Punica granatum L.) possess two groups of polyphenols that have health beneficial properties: anthocyanins (ATs, which also affect peel color); and hydrolysable tannins (HTs). Their biosynthesis intersects at 3-dehydroshikimate (3-DHS) in the shikimate pathway by the activity of shikimate dehydrogenase (SDH), which converts 3-DHS to shikimate (providing the precursor for AT biosynthesis) or to gallic acid (the precursor for HTs biosynthesis) using NADPH or NADP+ as a cofactor. The aim of this study is to gain more knowledge about the factors that regulate the levels of HTs and ATs, and the role of SDH. RESULTS:The results have shown that the levels of ATs and HTs are negatively correlated in the outer fruit peels of 33 pomegranate accessions, in the outer peels of two fruits exposed to sunlight, and in those covered by paper bags. When calli obtained from the outer fruit peel were subjected to light/dark treatment and osmotic stresses (imposed by different sucrose concentrations), it was shown that light with high sucrose promotes the synthesis of ATs, while dark at the same sucrose concentration promotes the synthesis of HTs. To verify the role of SDH, six PgSDHs (PgSDH1, PgSDH3-1,2, PgSDH3a-1,2 and PgSDH4) were identified in pomegranate. The expression of PgSDH1, which presumably contributes to shikimate biosynthesis, was relatively constant at different sucrose concentrations. However, the transcript levels of PgSDH3s and PgSDH4 increased with the accumulation of gallic acid and HTs under osmotic stress, which apparently accumulates to protect the cells from the stress. CONCLUSIONS:The results strongly suggest that the biosynthesis of HTs and ATs competes for the same substrate, 3-DHS, and that SDH activity is regulated not only by the NADPH/NADP+ ratio, but also by the expression of the PgSDHs. Since the outer peel affects the customer's decision regarding fruit consumption, such knowledge could be utilized for the development of new genetic markers for breeding pomegranates having higher levels of both ATs and HTs
Characterization of FANCL variants observed in patient cancer cells
Fanconi Anemia (FA) is a rare genetic disorder characterized by developmental defects, bone marrow failure and high predisposition to cancer. The FA DNA repair pathway is required in humans to coordinate repair of DNA interstrand crosslinks. The central event in the activation of the pathway is the monoubiquitination of FANCD2 and FANCI by the E2-E3 pair, Ube2T-FANCL, with the central UBC-RWD (URD) domain of FANCL recognising the substrates. Whole genome sequencing studies of cancer cells from patients identified point mutations in the FANCL URD domain. We analysed 17 such variants of FANCL, including known substrate binding mutants (W212A, W214A and L248A, F252A, L254A, I265A), a FA mutation (R221C) and 14 cancer-associated mutations (F110S, I136V, L149V, L154S, A192G, E215Q, E217K, R221W, T224K, M247V, F252L, N270K, V287G, E289Q) through recombinant expression analysis, thermal shift assay, interaction with FANCD2, in vitro ubiquitination activity, and cellular sensitivity to an interstrand crosslinking agent. We find that the FANCL mutations I136V, L154S, W212A and L214A, R221W, R221C, and V287G are destabilising, with N270K and E289Q destabilising the C-terminal helices of the URD domain. The hydrophobic patch mutant (L248A, F252A, L254A, I265A), along with mutations E217K, T224K, and M247V, cause defects in the catalytic function of FANCL. This highlights the C-terminal lobe of the FANCL URD domain as important for the activity and function of FANCL. These mutations which affect the fold and activity of FANCL may contribute to tumorigenesis in these non-FA cancer patients, and this implicates FA genes in general cancer progression
Performance of point charge embedding schemes for excited states in molecular organic crystals
Modeling excited state processes in molecular crystals is relevant for several applications. A popular approach for studying excited state molecular crystals is to use cluster models embedded in point charges. In this paper, we compare the performance of several embedding models in predicting excited states and S1-S0 optical gaps for a set of crystals from the X23 molecular crystal database. The performance of atomic charges based on ground or excited states was examined for cluster models, Ewald embedding, and self-consistent approaches. We investigated the impact of various factors, such as the level of theory, basis sets, embedding models, and the level of localization of the excitation. We consider different levels of theory, including time-dependent density functional theory and Tamm-Dancoff approximation (TDA) (DFT functionals: ωB97X-D and PBE0), CC2, complete active space self-consistent field, and CASPT2. We also explore the impact of selection of the QM region, charge leakage, and level of theory for the description of different kinds of excited states. We implemented three schemes based on distance thresholds to overcome overpolarization and charge leakage in molecular crystals. Our findings are compared against experimental data, G0W0-BSE, periodic TDA, and optimally tuned screened range-separated functionals
Understanding the psychosocial impact of weight loss following bariatric surgery: a qualitative study
Abstract
Background
Bariatric surgery leads to changes in mental health, quality of life and social functioning, yet these outcomes differ among individuals. In this study, we explore patients’ psychosocial experiences following bariatric surgery and elucidate the individual-level factors that may drive variation in psychosocial outcomes.
Methods
Eleven semi-structured focus groups with Michigan Bariatric Surgery Collaborative (MBSC) patients (n = 77). Interviews were audio recorded, transcribed verbatim, and analyzed using a grounded theory approach. Data on participant demographic characteristics were abstracted from the MBSC clinical registry.
Results
Most focus group participants were female (89%), white (64%), and married (65%). We identified three major themes: (1) change in self-perception; (2) change in perception by others; and (3) change in relationships. Each theme includes 3 sub-themes, demonstrating a range of positive and negative psychosocial experiences. For example, weight loss led to increased self-confidence among many participants while others described a loss of self-identity. Some noted improved relationships with family or friends while others experienced worsening or even loss of relationships due to perceived jealousy.
Conclusion
Weight loss following bariatric surgery leads to complex changes in self-perception and inter-personal relationships, which may be proximal mediators of commonly assessed mental health outcomes such as depression. Individuals considering bariatric surgery may benefit from anticipatory guidance about these diverse experiences, and post-surgical longitudinal monitoring should include evaluation for adverse psychosocial events.https://deepblue.lib.umich.edu/bitstream/2027.42/146725/1/40608_2018_Article_215.pd
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National inter-rater agreement of standardised simulated-patient-based assessments.
PURPOSE: The forthcoming UK Medical Licensing Assessment will require all medical schools in the UK to ensure that their students pass an appropriately designed Clinical and Professional Skills Assessment (CPSA) prior to graduation and registration with a licence to practice medicine. The requirements for the CPSA will be set by the General Medical Council, but individual medical schools will be responsible for implementing their own assessments. It is therefore important that assessors from different medical schools across the UK agree on what standard of performance constitutes a fail, pass or good grade. METHODS: We used an experimental video-based, single-blinded, randomised, internet-based design. We created videos of simulated student performances of a clinical examination at four scripted standards: clear fail (CF), borderline (BD), clear pass (CPX) and good (GD). Assessors from ten regions across the UK were randomly assigned to watch five videos in 12 different combinations and asked to give competence domain scores and an overall global grade for each simulated candidate. The inter-rater agreement as measured by the intraclass correlation coefficient (ICC) based on a two-way random-effects model for absolute agreement was calculated for the total domain scores. RESULTS: 120 assessors enrolled in the study, with 98 eligible for analysis. The ICC was 0.93 (95% CI 0.81-0.99). The mean percentage agreement with the scripted global grade was 74.4% (range 40.8-96.9%). CONCLUSIONS: The inter-rater agreement amongst assessors across the UK when rating simulated candidates performing at scripted levels is excellent. The level of agreement for the overall global performance level for simulated candidates is also high. These findings suggest that assessors from across the UK viewing the same simulated performances show high levels of agreement of the standards expected of students at a 'clear fail,' 'borderline,' 'clear pass' and 'good' level.Cambridge NIHR Biomedical Research Centr
Quantum state preparation, tomography, and entanglement of mechanical oscillators
Precisely engineered mechanical oscillators keep time, filter signals, and
sense motion, making them an indispensable part of today's technological
landscape. These unique capabilities motivate bringing mechanical devices into
the quantum domain by interfacing them with engineered quantum circuits.
Proposals to combine microwave-frequency mechanical resonators with
superconducting devices suggest the possibility of powerful quantum acoustic
processors. Meanwhile, experiments in several mechanical systems have
demonstrated quantum state control and readout, phonon number resolution, and
phonon-mediated qubit-qubit interactions. Currently, these acoustic platforms
lack processors capable of controlling multiple mechanical oscillators' quantum
states with a single qubit, and the rapid quantum non-demolition measurements
of mechanical states needed for error correction. Here we use a superconducting
qubit to control and read out the quantum state of a pair of nanomechanical
resonators. Our device is capable of fast qubit-mechanics swap operations,
which we use to deterministically manipulate the mechanical states. By placing
the qubit into the strong dispersive regime with both mechanical resonators
simultaneously, we determine the resonators' phonon number distributions via
Ramsey measurements. Finally, we present quantum tomography of the prepared
nonclassical and entangled mechanical states. Our result represents a concrete
step toward feedback-based operation of a quantum acoustic processor.Comment: 13 pages, 4+5 figure
Primary Metabolites, Anthocyanins, and Hydrolyzable Tannins in the Pomegranate Fruit
Pomegranate (Punica granatum L.) is an important and interesting fruit tree that is cultivated in many parts of the world. In recent years, along with the increase in its cultivation and consumption there has been a dramatic increase in the scientific interest in its biology, methods of cultivation, adaptation to environmental cues and its health-promoting properties. Quite a large proportion of the various metabolites produced in the pomegranate were determined and their content in the bark, roots, leaves, and fruit was reported. Many reviews on polyphenolic compound content, antioxidant activity and health-promoting compounds were published recently. However, only very few recent reports were dedicated to primary metabolites, despite the fact that much work was done on organic acids, sugars, proteins, lipids, and amino acids of the pomegranate fruit. In this review, a special effort was made to present these recent studies and the review is devoted to primary metabolites. The reported data show high variation in the content of primary metabolites within the pomegranate fruit; therefore the data is presented (whenever possible) according to fruit tissues (peel, arils, and seeds), developmental stages of the fruit, environmental and climatic conditions, and genetic background. Most of the data on pomegranate is based on metabolic content and contains no genetic or molecular analysis except for work done on anthocyanins and hydrolyzable tannins. In those cases, gene assignment and genetic control studies were pointed out in the review. The recent publication of the genome sequences from several pomegranate varieties and transcriptomic data from fruits, flowers, and leaves is expected to facilitate the understanding of genetic control of metabolites in pomegranate
Brain and Mind Integration: Childhood Sexual Abuse Survivors Experiencing Hyperbaric Oxygen Treatment and Psychotherapy Concurrently
Due to evidence that traumatic experience impacts the brain, the body (concerning sensory sensitivity), and the mind, a recent study that attempted to answer the question of whether the effects of CSA can be reversed by using a multidisciplinary approach consisting of dual treatments: hyperbaric & psychotherapy, was conducted. Its results showed that in addition to improvement of brain functionality, symptoms of distress were significantly reduced. The current paper aims to present the process as experienced by the 40 female childhood sexual abuse survivor participants. Data included participants' daily journals and drawings, and participants' summaries presented verbally and written, 6-months after the study ended. A phenomenological analysis was used. Results showed three phases, the initial phase—remembering the trauma from both physical and cognitive aspects, the second phase—physiological relaxation as well as positive memories emerge; and, the third phase—bouncing back to life. The results are discussed in light of the study theoretical model and Lev-Wiesel (2015) childhood sexual abuse conceptualization
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