bluuebunny/crossref_metadata_2025 huggingface dataset:
Archaeal DNA on the histone merry‐go‐round
Authors: Bhattacharyya Sudipta , Mattiroli Francesca , Luger Karolin
Published: May 2018

How did the nucleosome, the fundamental building block of all eukaryotic chromatin, evolve? This central question has been impossible to address because the four core histones that make up the protein core of the nucleosome are so highly conserved in all eukaryotes. With the discovery of small, minimalist histone‐like proteins in most known archaea, the likely origin of histones was identified. We recently determined the structure of an archaeal histone‐DNA complex, revealing that archaeal DNA topology and protein‐DNA interactions are astonishingly similar compared to the eukaryotic nucleosome. This was surprising since most archaeal histones form homodimers which consist only of the minimal histone fold and are devoid of histone tails and extensions. Unlike eukaryotic H2A–H2B and H3–H4 heterodimers that assemble into octameric particles wrapping ~ 150 bp DNA, archaeal histones form polymers around which DNA coils in a quasi‐continuous superhelix. At any given point, this superhelix has the same geometry as nucleosomal DNA. This suggests that the architectural role of histones (i.e. the ability to bend DNA into a nucleosomal superhelix) was established before archaea and eukaryotes diverged, while the ability to form discrete particles, together with signaling functions of eukaryotic chromatin (i.e. epigenetic modifications) were secondary additions.
Drought timing influences the legacy of tree growth recovery
Authors: Huang Mengtian , Wang Xuhui , Keenan Trevor F. , Piao Shilong
Published: May 2018

Whether and how the timing of extreme events affects the direction and magnitude of legacy effects on tree growth is poorly understood. In this study, we use a global database of Ring‐Width Index (RWI) from 2,500 sites to examine the impact and legacy effects (the departure of observed RWI from expected RWI) of extreme drought events during 1948–2008, with a particular focus on the influence of drought timing. We assessed the recovery of stem radial growth in the years following severe drought events with separate groupings designed to characterize the timing of the drought. We found that legacies from extreme droughts during the dry season (DS droughts) lasted longer and had larger impacts in each of the 3 years post drought than those from extreme droughts during the wet season (WS droughts). At the global scale, the average integrated legacy from DS droughts (0.18) was about nine times that from WS droughts (0.02). Site‐level comparisons also suggest stronger negative impacts or weaker positive impacts of DS droughts on tree growth than WS droughts. Our results, therefore, highlight that the timing of drought is a crucial factor determining drought impacts on tree recovery. Further increases in baseline aridity could therefore exacerbate the impact of punctuated droughts on terrestrial ecosystems.
Immunohistochemical and genetic characteristics of a colorectal mucin‐rich variant of traditional serrated adenoma
Authors: Hiromoto Takafumi , Murakami Takashi , Akazawa Yoichi , Sasahara Noriko , Saito Tsuyoshi , Sakamoto Naoto , Mitomi Hiroyuki , Nagahara Akihito , Yao Takashi
Published: May 2018

Aims

Recently, several morphological variants of traditional serrated adenoma (TSA) of the colorectum have been recognised, and mucin‐rich TSA (MR‐TSA) and serrated tubulovillous adenoma (S‐TVA) were introduced as distinct morphological variants separate from conventional TSA (C‐TSA). This aim of this study was to elucidate the immunohistochemical and genetic characteristics of MR‐TSAs.

Methods and results

We performed immunostaining for cytokeratins (CKs) (e.g. CK7 and CK20), mucins (e.g. MUC2, MUC5AC, MUC6, and CD10), β‐catenin, and MLH1, and direct sequencing of BRAF/KRAS, in 32 MR‐TSAs, 35 C‐TSAs, and 23 S‐TVAs. Immunohistochemically, all studied cases were positive for CK20, whereas few cases were positive for CK7, with no significant differences between the three groups. Regarding mucin‐phenotypic expression, all cases were positive for MUC2 but negative for MUC6 and CD10. MUC5AC positivity was found significantly more frequently in MR‐TSAs (53%) than in C‐TSAs (26%; P = 0.026). Nuclear β‐catenin expression in MR‐TSAs was significantly less frequent than in S‐TVAs (P = 0.002). MLH1 nuclear staining was retained in all cases. Genetically, MR‐TSAs (75%) more frequently harboured BRAF mutation than C‐TSAs (49%; P = 0.044) or S‐TVAs (4%; P < 0.001), whereas only two cases (6%) of MR‐TSA harboured a KRAS mutation, a frequency that was significantly lower than that in C‐TSAs (26%; P = 0.047) or S‐TVAs (57%; P < 0.001).

Conclusions

MR‐TSAs more frequently harboured BRAF mutations than C‐TSAs, and had distinct immunohistochemical characteristics. Our findings indicated that MR‐TSAs could be important precursors of BRAF‐mutated, microsatellite‐stable subtypes of colorectal carcinoma.
Longevity of bond strength of resin cements to root dentine after radiation therapy
Authors: Yamin P. A. , Pereira R. D. , Lopes F. C. , Queiroz A. M. , Oliveira H. F. , Saquy P. C. , Sousa‐Neto M. D.
Published: May 2018

Aim

To evaluate the bond strength and adhesive interface between several resin cements and root dentine immediately and 6 months after radiotherapy.

Methodology

Sixty maxillary canines were selected and randomly assigned to two groups (n = 30): one group was not irradiated and the other one was subjected to a cumulative radiation dose of 60 Gy. The teeth were sectioned to obtain roots 16 mm long and the canals were prepared with the Reciproc system (R50) and filled using a lateral condensation technique with an epoxy resin sealer. Each group was divided into three subgroups (n = 10) according to the resin cement used for fibreglass fibre post cementation: RelyX‐U200, Panavia‐F2.0 and RelyX ARC. The posts were cemented in accordance with the manufacturer's recommendations. Three 1‐mm‐thick dentine slices were then obtained from each root third. The first two slices in the crown‐apex direction of each third were selected for the push‐out test. The failure mode after debonding was determined with a stereo microscope. The third slice from each root third was selected for scanning electron microscopy (SEM) analyses to examine the resin cement–dentine interface with 100, 1000, 2000 and 4000× magnification. Bond strength data were analysed by anova and Tukey's test (α = 0.05).

Results

Significantly lower bond strength (P < 0.0001) was obtained after irradiation compared to nonirradiated teeth. RelyX‐U200 cemented fibre posts had the higher bond strength (15.17 ± 5.89) compared with RelyX ARC (P < 0.001) and Panavia‐F2.0 (P < 0.001). The evaluation after 6 months revealed lower bond strength values compared to the immediate values (P < 0.001) for irradiated and nonirradiated teeth. Cohesive failures occurred in the irradiated dentine. SEM revealed fractures, microfractures and fewer collagen fibres in irradiated root dentine. RelyX‐U200 and Panavia‐F2.0 were associated with a juxtaposed interface of the cement with the radicular dentine in irradiated and nonirradiated teeth, and for RelyX ARC, hybrid layer formation and tags were observed in both irradiated and nonirradiated teeth.

Conclusion

Radiation was associated with a decrease in the push‐out bond strength and with lower resin cement/root dentine interface adaptation. Self‐adhesive resin cement was a better alternative for fibre post cementation in teeth subjected to radiation therapy. The bond strength decreased after 6 months.
Stress and psoriasis
Authors: Rousset Laurie , Halioua Bruno
Published: May 2018

The links between psoriasis and stress are complex. This article proposes a review of the literature on the relationship between stress and psoriasis. In 31–88% of cases, patients report stress as being a trigger for their psoriasis. There was also a reported higher incidence of psoriasis in subjects who had a stressful event the previous year, suggesting that stress may have a role in triggering the disease in predisposed individuals. Stress is also a consequence of psoriasis outbreaks. Understanding the role of stress makes it appropriate to target stress when proposing treatment to patients with psoriasis. Several controlled studies have demonstrated that relaxation, hypnosis, biofeedback, and behavioral and cognitive stress management therapies have been effective in people with psoriasis.
Eyebrows cue grandiose narcissism
Authors: Giacomin Miranda , Rule Nicholas O.
Published: May 2018

Objective

Though initially charming and inviting, narcissists often engage in negative interpersonal behaviors. Identifying and avoiding narcissists therefore carries adaptive value. Whereas past research has found that people can judge others' grandiose narcissism from their appearance (including their faces), the cues supporting these judgments require further elucidation. Here, we investigated which facial features underlie perceptions of grandiose narcissism and how they convey that information.

Method and Results

In Study 1, we explored the face's features using a variety of manipulations, ultimately finding that accurate judgments of grandiose narcissism particularly depend on a person's eyebrows. In Studies 2A–2C, we identified eyebrow distinctiveness (e.g., thickness, density) as the primary characteristic supporting these judgments. Finally, we confirmed the eyebrows' importance in Studies 3A and 3B by measuring how much perceptions of narcissism changed when swapping narcissists' and non‐narcissists' eyebrows between faces.

Conclusions

Together, these data show that distinctive eyebrows reveal narcissists' personality to others, providing a basic understanding of the mechanism through which people can identify narcissistic personality traits with potential application to daily life.
Humidity‐dependent mechanical and adhesive properties of Arachnocampa tasmaniensis capture threads
Authors: Piorkowski D. , Blackledge T. A. , Liao C.‐P. , Doran N. E. , Wu C.‐L. , Blamires S. J. , Tso I.‐M.
Published: May 2018

Bioluminescent glow‐worms (Arachnocampa spp.) capture prey in glue‐coated silk capture threads hung from their nests on damp cave and wet forest substrates. In a dry environment, these animals are very susceptible to desiccation as their bodies can become life threateningly dry and their silk has been anecdotally observed to become non‐sticky. Water has a plasticizing effect on the structural proteins of several invertebrate silks, including those used in caddisfly nets, mussel byssus and spider webs. Moreover, water facilitates interfacial adhesion by spreading adhesive biomolecules in functionally analogous velvet worm slime and spider silk glue. We tested the effects of water on the mechanics and adhesion of Arachnocampa tasmaniensis capture threads sampled within damp caves. We found that threads tested at high humidity were three times more compliant and over 10‐fold more extensible than those tested at low humidity (30% RH). We also found the threads to be significantly more adhesive in high humidity with force at detachment increasing two orders of magnitude and work of adhesion increasing by five orders of magnitude compared to threads tested at low humidity. Our results unequivocally demonstrate that A. tasmaniensis capture thread functionality is dependent upon exposure to high humidity. Our results both confirm previous reports and indicate that the foraging habitat of these animals is restricted to caves and cave‐like environments, such as wet forests.
Genome‐wide evidence for divergent selection between populations of a major agricultural pathogen
Authors: Hartmann Fanny E. , McDonald Bruce A. , Croll Daniel
Published: May 2018

The genetic and environmental homogeneity in agricultural ecosystems is thought to impose strong and uniform selection pressures. However, the impact of this selection on plant pathogen genomes remains largely unknown. We aimed to identify the proportion of the genome and the specific gene functions under positive selection in populations of the fungal wheat pathogen Zymoseptoria tritici. First, we performed genome scans in four field populations that were sampled from different continents and on distinct wheat cultivars to test which genomic regions are under recent selection. Based on extended haplotype homozygosity and composite likelihood ratio tests, we identified 384 and 81 selective sweeps affecting 4% and 0.5% of the 35 Mb core genome, respectively. We found differences both in the number and the position of selective sweeps across the genome between populations. Using a XtX‐based outlier detection approach, we identified 51 extremely divergent genomic regions between the allopatric populations, suggesting that divergent selection led to locally adapted pathogen populations. We performed an outlier detection analysis between two sympatric populations infecting two different wheat cultivars to identify evidence for host‐driven selection. Selective sweep regions harboured genes that are likely to play a role in successfully establishing host infections. We also identified secondary metabolite gene clusters and an enrichment in genes encoding transporter and protein localization functions. The latter gene functions mediate responses to environmental stress, including interactions with the host. The distinct gene functions under selection indicate that both local host genotypes and abiotic factors contributed to local adaptation.
Pulse wave velocity in the microcirculation reflects both vascular compliance and resistance: Insights from computational approaches
Authors: Pan Qing , Wang Ruofan , Reglin Bettina , Fang Luping , Yan Jing , Cai Guolong , Kuebler Wolfgang M. , Pries Axel R. , Ning Gangmin
Published: May 2018

Objective

PWV is the speed of pulse wave propagation through the circulatory system. mPWV emerges as a novel indicator of hypertension, yet it remains unclear how different vascular properties affect mPWV. We aim to identify the biomechanical determinants of mPWV.

Methods

A 1D model was used to simulate PWV in a rat mesenteric microvascular network and, for comparison, in a human macrovascular arterial network. Sensitivity analysis was performed to assess the relationship between PWV and vascular compliance and resistance.

Results

The 1D model enabled adequate simulation of PWV in both micro‐ and macrovascular networks. Simulated arterial PWV changed as a function of vascular compliance but not resistance, in that arterial PWV varied at a rate of 0.30 m/s and −6.18 × 10−3 m/s per 10% increase in vascular compliance and resistance, respectively. In contrast, mPWV depended on both vascular compliance and resistance, as it varied at a rate of 2.79 and −2.64 cm/s per 10% increase in the respective parameters.

Conclusions

The present study identifies vascular compliance and resistance in microvascular networks as critical determinants of mPWV. We anticipate that mPWV can be utilized as an effective indicator for the assessment of microvascular biomechanical properties.
Defaunation impacts on seed survival and its effect on the biomass of future tropical forests
Authors: de Paula Mateus Dantas , Groeneveld Juergen , Fischer Rico , Taubert Franziska , Martins Valéria F. , Huth Andreas
Published: May 2018

Large animal species, which provide important ecological functions such as dispersal of seeds or top–down control of seed predators, are very vulnerable in fragmented forests, being unable to survive in small fragments, and facing increasing hunting pressure. The loss of large animals affects two main ecological processes crucial for the tree reproductive cycle: seed dispersal of large seeds (e.g. provided by tapirs) and control of seed predator population (e.g. provided by large cats). The changes in both processes are expected to increase seed mortality since seeds are not dispersed away from conspecifics (causing increased pre‐dispersal mortality due to negative density dependent effects) and/or face increased predation after a dispersal event (post‐dispersal mortality). Although an extensive body of empirical knowledge exists on seed predation, the link between seed loss and adult tree community composition and structure is not well established, as well as the temporal scale seed changes affect adults. Using an individual‐based forest model (FORMIND), we evaluate the long‐term consequences of increased pre and post‐dispersal seed mortality on the future forest biomass retention of a Brazilian northeastern Atlantic forest. Our results show that forest biomass is significantly affected after 80–93% pre‐dispersal loss of large seeds, or post‐dispersal predation densities of 20–25 predators per parent tree. Large‐seeded tree species are at increased risk of local extinction causing up to 26.2% loss of forest biomass when both pre and post‐dispersal processes are combined. However, these changes can last up to 100 years after the occurrence of defaunation. In summary we conclude that large animal loss has the potential to reduce future forest biomass and tree species‐richness by impacting seed survival, and should be considered in the planning of biodiversity friendly landscapes as well as in calculations of the global carbon budget.
Wheeze trajectories are modifiable through early‐life intervention and predict asthma in adolescence
Authors: Owora Arthur H. , Becker Allan B. , Chan‐Yeung Moira , Chan Edmond S. , Chooniedass Rishma , Ramsey Clare , Watson Wade T. A. , Azad Meghan B.
Published: May 2018

Background

The objectives of this study were to identify developmental trajectories of wheezing using data‐driven methodology, and to examine whether trajectory membership differentially impacts the effectiveness of primary preventive efforts that target modifiable asthma risk factors.

Methods

Secondary analysis of the Canadian Asthma Primary Prevention Study (CAPPS), a multifaceted prenatal intervention among children at high risk of asthma, followed from birth to 15 years. Wheezing trajectories were identified by latent class growth analysis. Predictors, intervention effects, and asthma diagnoses were examined between and within trajectory groups.

Results

Among 525 children, 3 wheeze trajectory groups were identified: Low‐Progressive (365, 69%), Early‐Transient (52, 10%), and Early‐Persistent (108, 21%). The study intervention was associated with lower odds of Early‐Transient and Early‐Persistent wheezing (P < .01). Other predictors of wheeze trajectories included, maternal asthma, maternal education, city of residence, breastfeeding, household pets, infant sex and atopy at 12 months. The odds of an asthma diagnosis were three‐fold to six‐fold higher in the Early‐Persistent vs Low‐Progressive group at all follow‐up assessments (P = .03), whereas Early‐Transient wheezing (limited to the first year) was not associated with asthma. In the Early‐Persistent group, the odds of wheezing were lower among intervention than control children (adjusted odds ratio: 0.67; 95% CI: 0.48; 0.93) at 7 years.

Conclusions

Using data‐driven methodology, children can be classified into clinically meaningful wheeze trajectory groups that appear to be programmed by modifiable and non‐modifiable factors, and are useful for predicting asthma risk. Early‐life interventions can alter some wheeze trajectories (ie, Early‐Persistent) in infancy and reduce wheezing prevalence in mid‐childhood.
Chromosome‐based survey sequencing reveals the genome organization of wild wheat progenitor Triticum dicoccoides
Authors: Akpinar Bala Ani , Biyiklioglu Sezgi , Alptekin Burcu , Havránková Miroslava , Vrána Jan , Doležel Jaroslav , Distelfeld Assaf , Hernandez Pilar ,   The IWGSC, Budak Hikmet
Published: May 2018

Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is the progenitor of wheat. We performed chromosome‐based survey sequencing of the 14 chromosomes, examining repetitive sequences, protein‐coding genes, miRNA/target pairs and tRNA genes, as well as syntenic relationships with related grasses. We found considerable differences in the content and distribution of repetitive sequences between the A and B subgenomes. The gene contents of individual chromosomes varied widely, not necessarily correlating with chromosome size. We catalogued candidate agronomically important loci, along with new alleles and flanking sequences that can be used to design exome sequencing. Syntenic relationships and virtual gene orders revealed several small‐scale evolutionary rearrangements, in addition to providing evidence for the 4AL‐5AL‐7BS translocation in wild emmer wheat. Chromosome‐based sequence assemblies contained five novel miRNA families, among 59 families putatively encoded in the entire genome which provide insight into the domestication of wheat and an overview of the genome content and organization.
Ectopic expression of ORANGE promotes carotenoid accumulation and fruit development in tomato
Authors: Yazdani Mohammad , Sun Zhaoxia , Yuan Hui , Zeng Shaohua , Thannhauser Theodore W. , Vrebalov Julia , Ma Qiyue , Xu Yimin , Fei Zhangjun , Van Eck Joyce , Tian Shiping , Tadmor Yaakov , Giovannoni James J. , Li Li
Published: May 2018

Carotenoids are critically important to plants and humans. The ORANGE (OR) gene is a key regulator for carotenoid accumulation, but its physiological roles in crops remain elusive. In this study, we generated transgenic tomato ectopically overexpressing the Arabidopsis wild‐type OR (AtORWT) and a ‘golden SNP’‐containing OR (AtORHis). We found that AtORHis initiated chromoplast formation in very young fruit and stimulated carotenoid accumulation at all fruit developmental stages, uncoupled from other ripening activities. The elevated levels of carotenoids in the AtOR lines were distributed in the same subplastidial fractions as in wild‐type tomato, indicating an adaptive response of plastids to sequester the increased carotenoids. Microscopic analysis revealed that the plastid sizes were increased in both AtORWT and AtORHis lines at early fruit developmental stages. Moreover, AtOR overexpression promoted early flowering, fruit set and seed production. Ethylene production and the expression of ripening‐associated genes were also significantly increased in the AtOR transgenic fruit at ripening stages. RNA‐Seq transcriptomic profiling highlighted the primary effects of OR overexpression on the genes in the processes related to RNA, protein and signalling in tomato fruit. Taken together, these results expand our understanding of OR in mediating carotenoid accumulation in plants and suggest additional roles of OR in affecting plastid size as well as flower and fruit development, thus making OR a target gene not only for nutritional biofortification of agricultural products but also for alteration of horticultural traits.
Genetic improvement of the shoot architecture and yield in soya bean plants via the manipulation of GmmiR156b
Authors: Sun Zhengxi , Su Chao , Yun Jinxia , Jiang Qiong , Wang Lixiang , Wang Youning , Cao Dong , Zhao Fang , Zhao Qingsong , Zhang Mengchen , Zhou Bin , Zhang Lei , Kong Fanjiang , Liu Baohui , Tong Yiping , Li Xia
Published: May 2018

The optimization of plant architecture in order to breed high‐yielding soya bean cultivars is a goal of researchers. Tall plants bearing many long branches are desired, but only modest success in reaching these goals has been achieved. MicroRNA156 (miR156)‐SQUAMOSA PROMOTER BINDING PROTEIN‐LIKE (SPL) gene modules play pivotal roles in controlling shoot architecture and other traits in crops like rice and wheat. However, the effects of miR156‐SPL modules on soya bean architecture and yield, and the molecular mechanisms underlying these effects, remain largely unknown. In this study, we achieved substantial improvements in soya bean architecture and yield by overexpressing GmmiR156b. Transgenic plants produced significantly increased numbers of long branches, nodes and pods, and they exhibited an increased 100‐seed weight, resulting in a 46%–63% increase in yield per plant. Intriguingly, GmmiR156b overexpression had no significant impact on plant height in a growth room or under field conditions; however, it increased stem thickness significantly. Our data indicate that GmmiR156b modulates these traits mainly via the direct cleavage of SPL transcripts. Moreover, we found that GmSPL9d is expressed in the shoot apical meristem and axillary meristems (AMs) of soya bean, and that GmSPL9d may regulate axillary bud formation and branching by physically interacting with the homeobox gene WUSCHEL (WUS), a central regulator of AM formation. Together, our results identify GmmiR156b as a promising target for the improvement of soya bean plant architecture and yields, and they reveal a new and conserved regulatory cascade involving miR156‐SPL‐WUS that will help researchers decipher the genetic basis of plant architecture.
Pathological antibody‐mediated rejection in pediatric heart transplant recipients: Immunologic risk factors, hemodynamic significance, and outcomes
Authors: Hollander Seth A. , Peng David M. , Mills Marcos , Berry Gerald J. , Fedrigo Marny , McElhinney Doff B. , Almond Christopher S. , Rosenthal David N.
Published: May 2018

Biopsy‐diagnosed pAMR has been observed in over half of pediatric HT recipients within 6 years of transplantation. We report the incidence and outcomes of pAMR at our center. All endomyocardial biopsies for all HT recipients transplanted between 2010 and 2015 were reviewed and classified using contemporary ISHLT guidelines. Graft dysfunction was defined as a qualitative decrement in systolic function by echocardiogram or an increase of ≥3 mm Hg in atrial filling pressure by direct measurement. Among 96 patients, pAMR2 occurred in 7 (7%) over a median follow‐up period of 3.1 years, while no cases of pAMR3 occurred. A history of CHD, DSA at transplant, and elevated filling pressures were associated with pAMR2. Five‐sixths (83%) of patients developed new C1q+ DSA at the time of pAMR diagnosis. There was a trend toward reduced survival, with 43% of patients dying within 2.3 years of pAMR diagnosis.
A case series of perioperative variables in relation to short‐term outcomes in pediatric renal transplant recipients
Authors: Goh Celine Y. Y. , Hume‐Smith Helen , Kessaris Nicos , Marks Stephen D.
Published: May 2018

Multiple perioperative variables have been shown in existing literature to influence long‐term outcomes of pediatric RTx, such as allograft survival. Their impact on short‐term outcomes is not as well‐documented. This case series aims to investigate the effects of nine perioperative variables on two short‐term outcomes in pRTR: 1‐week post‐operative eGFR and post‐operative LOS. A total of 73 pRTR transplanted over 3 years from 2012 to 2014 at a single center were studied retrospectively and statistical analyses were performed. There was higher 1‐week post‐operative eGFR in pRTR who received living donor transplants compared to those who received deceased donor transplants (P=.01), with mean eGFR of 135 mL/min/1.73 m2 and 82 mL/min/1.73 m2, respectively. Aorta‐IVC anastomosis was associated with longer LOS compared to iliac vessel anastomosis (P=.03), with median LOS of 19 and 13 days, respectively. There were no significant effects on 1‐week eGFR or LOS of the seven other variables: pRTR age and gender, donor age, preoperative donor SBP, intraoperative mean CVP before graft perfusion, intraoperative median SBP z score after graft perfusion, and intraoperative fluid volume. Living donor transplants were associated with higher 1‐week post‐operative eGFR compared to deceased donor transplants. Aorta‐IVC anastomosis was significantly associated with longer LOS compared to iliac vessel anastomosis.
Photophysical and Photochemical Properties of 3‐methylpterin as a New and More Stable Pterin‐type Photosensitizer
Authors: Estébanez Sandra , Lorente Carolina , Kaufman Teodoro S. , Larghi Enrique L. , Thomas Andrés H. , Serrano Mariana P.
Published: May 2018

Pterin derivatives are heterocyclic compounds which are present in different biological systems. Neutral aqueous solutions of pterins present acid–base and keto–enol equilibria. These compounds, under UV‐A radiation fluoresce, undergo photooxidation, generate reactive oxygen species and photoinduce the oxidation of biological substrates. As photosensitizers, they may act through different mechanisms, mainly through an electron transfer‐initiated process (type‐I mechanism), but they also produce singlet molecular oxygen (1O2) upon irradiation (type‐II mechanism). In general, upon UV‐A excitation two triplet states, corresponding to the lactim and lactam tautomers, are formed, but only the last one is the responsible for the photosensitized reactions of biomolecules. We present a study of the photochemical properties of 3‐methylpterin (3‐Mep) which, in contrast to most pterin derivatives, exists only in the lactam form. Also an improvement in the synthesis of 3‐Mep is reported. The spectroscopic properties 3‐Mep in aqueous solution were similar to those of the unsubstituted pterin derivative (Ptr) in its acid form, such as absorption, fluorescent and phosphorescent emission spectra. Experiments using 2′‐deoxyguanosine 5′‐monophosphate (dGMP) as oxidizable target demonstrated that methylation at C‐3 position of the pterin moiety does not affect significantly the efficiency of photosensitization, but results in a more photostable sensitizer.
Big Data in Supply Chain Management
Authors: Sanders Nada R. , Ganeshan Ram
Published: May 2018

“Big data” has become ubiquitous. It is impacting every aspect of how companies organize and manage their supply chains. Supply chains are evolving into digital networks connected via devices and sensors revolutionizing how data is generated, shared, and communicated. It is also unlocking new research streams. In this study, we introduce papers in this issue and showcase Big Data research trends across supply chain management.
Wheat leaf resistance to Pyrenophora tritici‐repentis induced by silicon activation of phenylpropanoid metabolism
Authors: Dorneles K. R. , Pazdiora P. C. , Hoffmann J. F. , Chaves F. C. , Monte L. G. , Rodrigues F. A. , Dallagnol L. J.
Published: May 2018

Tan spot caused by Pyrenophora tritici‐repentis is a disease present in all wheat‐producing countries and silicon (Si) treatment of wheat plants has been shown to increase plant resistance to tan spot. In this study, the effect of phenylpropanoid metabolism on resistance to tan spot was evaluated and some phenolic compounds that accumulated in response to P. tritici‐repentis attack were identified. Furthermore, the effect of Si on phenylalanine ammonia‐lyase (PAL) activity and phenolic compound accumulation were determined in situ. Antifungal activity of differentially accumulated phenolic compounds was also evaluated in in vitro tests. Results showed that the increase in concentration of phenolic compounds was greatest at the onset of infection, and that some compounds showed fungitoxic effects including fungal tip swelling, granulation of germ tube and hyphae, and hyphal hyperbranching. Silicon‐induced reduction in both lesion size and tan spot disease progression were associated with activation of phenylpropanoid metabolism. PAL activity and accumulation of antifungal phenolic compounds were greater in pathogen‐inoculated plants supplied with Si. In these plants, fluorescence indicative of accumulation of phenolic compounds occurred early in epidermal cells and its intensity increased during the evaluation period, showing higher numbers of fluorescent cells around infected cells. Thus, the combined responses of cell fluorescence at sites of infection, increased PAL activity and accumulation of phenols indicate that Si strengthened wheat defence responses to infection by P. tritici‐repentis, reducing the severity of tan spot.
Alluvial stratification styles in a large, flash‐flood influenced dryland river: The Luni River, Thar Desert, north‐west India
Authors: Carling Paul A. , Leclair Suzanne F.
Published: May 2018

Detailed descriptions of the architecture of dryland‐river deposits are few, which hinders the understanding of stratigraphic development in aggradational settings. The aim of this study was to obtain new insight into the depositional dynamics and resultant stratigraphy of steep, high‐energy dryland rivers in particular. The study site is within the Luni River, the largest river in the Thar Desert, India. A 700 m wide section, 5 m deep, was logged and the dated‐stratification related to the flow regimen. Seasonal discharges may reach 14 000 m3 sec−1 but the bed is usually dry. The deposits consist mainly of sandy upper‐stage plane bed lamination and low‐angle stratification deposited in supercritical flows with some strata showing gravel‐lense antidune signatures. Estimated hydraulic parameters indicate a dominance of the upper‐stage plane bed state. Less frequent dune trough cross‐sets occur at all depths, yet commonly as isolated sets with erosive upper boundaries. Localized deep scour causes slumping and soft‐sediment deformation. Scour holes adjacent to older bedded deposits are rapidly infilled, often by massive deposits. Repeated deep scour results in units of deposition of different ages (50 to 500 a bp) and different facies found at similar shallow depths (2 to 3 m). Older dates (1 to 2 ka bp) occur in lower strata (4 to 5 m depths) at which depths younger units also are preserved locally. The steep, high‐energy depositional environment promotes the unusual preservation and predominance of upper‐stage facies, in contrast to a relative paucity of lower‐stage facies. Frequent local deep‐scour during floods means that specific facies rarely can be traced across the river channel for more than a few metres, but are replaced by other facies in close proximity. These results should help interpretation of high‐energy sediment deposits widely and improve understanding of the stratigraphic development in modern dryland rivers, and in characterizing oil, gas and groundwater reservoirs in the dryland geological record more generally.
Rice RAD51 paralogs play essential roles in somatic homologous recombination for DNA repair
Authors: Xu Zhan , Zhang Jianxiang , Xu Meng , Ji Wen , Yu Meimei , Tao Yajun , Gong Zhiyun , Gu Minghong , Yu Hengxiu
Published: May 2018

Synthesis‐dependent strand annealing (SDSA) and single‐strand annealing (SSA) are the two main homologous recombination (HR) pathways in double‐strand break (DSB) repair. The involvement of rice RAD51 paralogs in HR is well known in meiosis, although the molecular mechanism in somatic HR remains obscure. Loss‐of‐function mutants of rad51 paralogs show increased sensitivity to the DSB‐inducer bleomycin, which results in greatly compromised somatic recombination efficiencies (xrcc3 in SDSA, rad51b and xrcc2 in SSA, rad51c and rad51d in both). Using immunostaining, we found that mutations in RAD51 paralogs (XRCC3, RAD51C, or RAD51D) lead to tremendous impairment in RAD51 focus formation at DSBs. Intriguingly, the RAD51C mutation has a strong effect on the protein loading of its partners (XRCC3 and RAD51B) at DSBs, which is similar to the phenomenon observed in the case of blocking PI3K‐like kinases in wild‐type plant. We conclude that the rice CDX3 complex acts in SDSA recombination while the BCDX2 complex acts in SSA recombination in somatic DSB repair. Importantly, RAD51C serves as a fulcrum for the local recruitment of its partners (XRCC3 for SDSA and RAD51B for SSA) and is positively modulated by PI3K‐like kinases to facilitate both the SDSA and SSA pathways in RAD51 paralog‐dependent somatic HR.
Effect of Intermittent Pneumatic Compression on Preventing Deep Vein Thrombosis Among Stroke Patients: A Systematic Review and Meta‐Analysis
Authors: Zhang Dongdong , Li Fenfen , Li Xiaotian , Du Ganqin
Published: May 2018

Background

Deep vein thrombosis (DVT) and subsequent pulmonary embolism (PE) are common complications of stroke. However, the effect of intermittent pneumatic compression (IPC) for patients after stroke is uncertain.

Objectives

To assess the effectiveness and safety of IPC in reducing the risk of DVT, PE, and mortality in stroke patients.

Methods

We searched leading medical databases including Medline, EMBASE, Cochrane Library, Wanfang, CNKI, and CBM, from inception to June 2, 2017. Studies comparing IPC with no IPC in stroke patients were included. Agreement was measured using simple agreement and kappa statistics. The rates of PE, DVT, and mortality were compared. The results were pooled using a fixed effects model to evaluate the differences between the IPC and control groups. If there was significant heterogeneity in the pooled result, a random effect model was used.

Results

We identified seven randomized controlled trials that included 3,551 stroke patients. The average calculated κ for the various parameters was κ = 0.96 (0.70–1). Overall, IPC significantly reduced the incidence of DVT in stroke patients (risk ratio [RR] = 0.50; 95% confidence interval [CI 0.27, 0.94]). At the same time, IPC increased IPC‐related adverse events (RR = 5.71; 95% CI [3.40, 9.58]). Though IPC was associated with a significant increase in survival by 4.5 days during 6 months of follow‐up (148–152 days; 95% CI [–0.2, 9.1]), there was a mean gain of only 0.9 days (26.7–27.6 days; 95% CI [2.1, 3.9]) in quality‐adjusted survival during the 6‐month follow‐up. Overall, sensitivity analyses did not alter these findings.

Linking Evidence to Action

This review provides an important basis for preventing DVT in stroke patients, especially in hemorrhagic stroke patients. IPC significantly reduces the risk of DVT and significantly improves survival in a wide variety of patients who are immobile after stroke. However, IPC does not significantly improve quality‐adjusted survival. Clinicians should take functional status and quality of life into consideration when making decisions for stroke patients.
Appropriately testing patients with intermediate risk for coronary artery disease: how well are we doing?
Authors: Alsaad Ali A , Shapiro Brian P
Published: May 2018

Background

Cardiovascular risk assessment and stratification of stable coronary artery disease represents a pivotal component of coronary artery disease management. The introduction of risk stratification tools has advanced the detection of patients with intermediate to high risk for coronary artery events. These patients will ultimately undergo non-invasive and invasive cardiovascular testing.

Objective

To synthesise evidence illustrating risk stratification tools and non-invasive testing for patients with intermediate risk for coronary artery disease and suggest a simple method for clinicians to follow prior to ordering non-invasive cardiovascular testing.

Study selection

Literature review of PubMed and MEDLINE Central on studies and evidence highlighting the appropriate use criteria for radionuclide myocardial perfusion imaging.

Findings and conclusions

Overtestingusing myocardial perfusion imaging is well documented in several studies in the literature. Few studies highlighted the importance of the appropriate use criteria for radionuclide myocardial perfusion imaging, which can reduce unnecessary testing in patients with suspected coronary artery disease. Herein, we propose ‘Simple Steps to Follow’ to be considered by clinicians prior to ordering radionuclide myocardial perfusion imaging. The target audience of this article is internal and family medicine primary care physicians and other non-cardiologist physicians.
Role of sampling times and serum cortisol cut-off concentrations on the routine assessment of adrenal function using the standard cosyntropin test in an academic hospital from Spain: a retrospective chart review
Authors: Ortiz-Flores Andrés E , Santacruz Elisa , Jiménez-Mendiguchia Lucía , García-Cano Ana , Nattero-Chávez Lia , Escobar-Morreale Héctor F , Luque-Ramírez Manuel
Published: May 2018

Objectives

Aiming to validate the use of a single poststimulus sampling protocol for cosyntropin test short standard high-dose test (SST) in our institution, our primary objectives were (1) to determine the concordance between 30 and 60 min serum cortisol (SC) measurements during SST; and (2) to evaluate the diagnostic agreement between both sampling times when using classic or assay-specific and sex-specific SC cut-off values. The secondary objectives included (1) estimating the specificity and positive predictive value of 30 and 60 min sampling times while considering the suspected origin of adrenal insufficiency (AI); and (2) obtaining assay-specific cut-off values for SC after SST in a group of subjects with normal hypothalamic–pituitary–adrenal (HPA) axis.

Design and setting

This is a retrospective chart review study conducted at a Spanish academic hospital from 2011 to 2015.

Participants and interventions

Two groups were evaluated: (1) a main study group including 370 patients in whom SC was measured at 30 and 60 min during SST; and (2) a confirmative group that included 150 women presenting with a normal HPA axis in whom SST was conducted to rule out late-onset congenital adrenal hyperplasia. Diagnostic agreement between both sampling times was assessed by considering both classic (500 nmol/L) and assay-specific SC cut-off concentrations.

Results

Diagnostic agreement between both sampling times was greater when applying sex-specific and assay-specific cut-off values instead of the classic cut-off values. For suspected primary AI, 30 min SC determination was enough to establish a diagnosis in over 95% of cases, without missing any necessary treatment. When central AI is suspected, 60 min SC measurement was more specific, establishing a diagnosis in over 97% of cases.

Conclusions

Sex-specific and assay-specific SC cut-off values improve the diagnostic accuracy of SST. For primary disease, a subnormal SC response at 30 min is a reliable marker of adrenal dysfunction. On the contrary, when central AI is suspected, 60 min SC measurement improves the diagnostic accuracy of the test.
What is the effect of prolonged sitting and physical activity on thoracic spine mobility? An observational study of young adults in a UK university setting
Authors: Heneghan Nicola R , Baker Gemma , Thomas Kimberley , Falla Deborah , Rushton Alison
Published: May 2018

Objective

Sedentary behaviour has long been associated with neck and low back pain, although relatively little is known about the thoracic spine. Contributing around 33% of functional neck movement, understanding the effect of sedentary behaviour and physical activity on thoracic spinal mobility may guide clinical practice and inform research of novel interventions.

Design

An assessor-blinded prospective observational study designed and reported in accordance with Strengthening the Reporting of Observational Studies in Epidemiology.

Setting

UK university (June–September 2016).

Participants

A convenience sample (18–30 years) was recruited and based on self-report behaviours, the participants were assigned to one of three groups: group 1, sitters—sitting >7 hours/day+physical activity<150 min/week; group 2, physically active—moderate exercise >150 min/week+sitting <4 hours/day and group 3, low activity—sitting 2–7 hours/day+physical activity <150 min/week.

Outcome measures

Thoracic spine mobility was assessed in the heel-sit position using Acumar digital goniometer; a validated measure. Descriptive and inferential analyses included analysis of variance and analysis of covariance for between group differences and Spearman’s rank correlation for post hoc analysis of associations.

Results

The sample (n=92) comprised: sitters n=30, physically active n=32 and low activity n=30. Groups were comparable with respect to age and body mass index.

Thoracic spine mobility (mean (SD)) was: group 1 sitters 64.75 (1.20), group 2 physically active 74.96 (1.18) and group 3 low activity 68.44 (1.22). Significant differences were detected between (1) sitters and low activity, (2) sitters and physically active (p<0.001). There was an overall effect size of 0.31. Correlations between thoracic rotation and exercise duration (r=0.67, p<0.001), sitting duration (r=−0.29, p<0.001) and days exercised (r=0.45, p<0.001) were observed.

Conclusions

Findings evidence reduced thoracic mobility in individuals who spend >7 hours/day sitting and <150 min/week of physical activity. Further research is required to explore possible causal relationships between activity behaviours and spinal musculoskeletal health.
How a deliberative approach includes women in the decisions of screening mammography: a citizens' jury feasibility study in Andalusia, Spain
Authors: Baena-Cañada José M , Luque-Ribelles Violeta , Quílez-Cutillas Alicia , Rosado-Varela Petra , Benítez-Rodríguez Encarnación , Márquez-Calderón Soledad , Rivera-Bautista Juan Manuel
Published: May 2018

Objectives

To verify whether a citizens' jury study is feasible to the Andalusian population and to know if women, when better informed, are able to answer the research question of whether the Andalusian Public Health System must continue offering screening mammography to women aged 50–69. The reasons for the pertinent decision and recommendations to the political authorities will be stated.

Design

Qualitative research study with the methodology of citizens' jury.

Setting

Breast cancer screening programme in Andalusia (Spain).

Participants

Thirteen women aged 50–69 with secondary school or higher education accepted to participate as a jury. Two epidemiologists were the expert witnesses. The main researcher was the neutral moderator.

Interventions

Jury met on Monday, 15 February 2016. The moderator indicated to the jury that it had to assess the screening programme’s key benefits and main harm. On Tuesday, 16 February, the expert witnesses positioned for and against the programme. On Thursday, 18 February, the jury deliberated, reached final conclusions, submitted its vote and stated its recommendations to politicians. The deliberation session was transcribed and analysed with the support of ATLAS.ti.5.2 software.

Primary and secondary outcome measures

Feasibility in the Andalusian population, women’s vote and opinion, reasons for votes and recommendations to political authorities.

Results

Eleven participants voted yes and two voted no. There are three reasons to vote ‘yes’: health, the test nature, and individual freedom. Some women invoke the lack of efficacy and the cost to justify their negative vote, at least in universal terms. On completion, they made suggestions to be submitted to the pertinent authorities for the improvement of information, psychology services and research.

Conclusions

The deliberative strategy is feasible and causes a favourable positioning regarding screening mammography, although information changes the opinion of some women, who desire informed decision making and to keep or increase medicalisation in their lives.