bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catechol-O-methyltransferase Val(108/158)Met polymorphism affects fronto-limbic connectivity during emotional processing in bipolar disorder
Authors: Vai B. , Riberto M. , Poletti S. , Bollettini I. , Lorenzi C. , Colombo C. , Benedetti F. 
Published: February 2017

AbstractCatechol-O-methyltransferase (COMT) inactivates catecholamines, Val/Val genotype was associated to an increased amygdala (Amy) response to negative stimuli and can influence the symptoms severity and the outcome of bipolar disorder, probably mediated by the COMT polymorphism (rs4680) interaction between cortical and subcortical dopaminergic neurotransmission. The aim of this study is to explore how rs4680 and implicit emotional processing of negative emotional stimuli could interact in affecting the Amy connectivity in bipolar depression. Forty-five BD patients (34 Met carriers vs. 11 Val/Val) underwent fMRI scanning during implicit processing of fearful and angry faces. We explore the effect of rs4680 on the strength of functional connectivity from the amygdalae to whole brain. Val/Val and Met carriers significantly differed for the connectivity between Amy and dorsolateral prefrontal cortex (DLPFC) and supramarginal gyrus. Val/Val patients showed a significant positive connectivity for all of these areas, where Met carriers presented a significant negative one for the connection between DLPFC and Amy. Our findings reveal a COMT genotype-dependent difference in corticolimbic connectivity during affective regulation, possibly identifying a neurobiological underpinning of clinical and prognostic outcome of BD. Specifically, a worse antidepressant recovery and clinical outcome previously detected in Val/Val patients could be associated to a specific increased sensitivity to negative emotional stimuli.
Kynurenine pathway metabolomics predicts and provides mechanistic insight into multiple sclerosis progression
Authors: Lim Chai K. , Bilgin Ayse , Lovejoy David B. , Tan Vanessa , Bustamante Sonia , Taylor Bruce V. , Bessede Alban , Brew Bruce J. , Guillemin Gilles J. 
Published: February 2017

AbstractActivation of the kynurenine pathway (KP) of tryptophan metabolism results from chronic inflammation and is known to exacerbate progression of neurodegenerative disease. To gain insights into the links between inflammation, the KP and multiple sclerosis (MS) pathogenesis, we investigated the KP metabolomics profile of MS patients. Most significantly, we found aberrant levels of two key KP metabolites, kynurenic acid (KA) and quinolinic acid (QA). The balance between these metabolites is important as it determines overall excitotoxic activity at the N-methyl-D-Aspartate (NMDA) receptor. We also identified that serum KP metabolic signatures in patients can discriminate clinical MS subtypes with high sensitivity and specificity. A C5.0 Decision Tree classification model discriminated the clinical subtypes of MS with a sensitivity of 91%. After validation in another independent cohort, sensitivity was maintained at 85%. Collectively, our studies suggest that abnormalities in the KP may be associated with the switch from early-mild stage MS to debilitating progressive forms of MS and that analysis of KP metabolites in MS patient serum may have application as MS disease biomarkers.
Preoperative adjuvant transarterial chemoembolization cannot improve the long term outcome of radical therapies for hepatocellular carcinoma
Authors: Jianyong Lei , Jinjing Zhong , Lunan Yan , Jingqiang Zhu , Wentao Wang , Yong Zeng , Bo Li , Tianfu Wen , Jiaying Yang 
Published: February 2017

AbstractCombinations of transarterial chemoembolization (TACE) and radical therapies (pretransplantation, resection and radiofrequency ablation) for hepatocellular carcinoma (HCC) have been reported as controversial issues in recent years. A consecutive sample of 1560 patients with Barcelona Clinic Liver Cancer (BCLC) stage A/B HCC who underwent solitary Radiofrequency ablation (RFA), resection or liver transplantation (LT) or adjuvant pre-operative TACE were included. The 1-, 3- and 5-year overall survival rates and tumor-free survival rates were comparable between the solitary radical therapy group and TACE combined group in the whole group and in each of the subgroups (RFA, resection and LT) (P > 0.05). In the subgroup analysis, according to BCLC stage A or B, the advantages of adjuvant TACE were also not observed (P > 0.05). A Neutrophil-lymphocyte ratio (NLR) more than 4, multiple tumor targets, BCLC stage B, and poor histological grade were significant contributors to the overall and tumor-free survival rates. In conclusions, our results indicated that preoperative adjuvant TACE did not prolong long-term overall or tumor-free survival, but LT should nevertheless be considered the first choice for BCLC stage A or B HCC patients. Radical therapies should be performed very carefully in BCLC stage B HCC patients.
Thermal conductance of Nb thin films at sub-kelvin temperatures
Authors: Feshchenko A. V. , Saira O.-P. , Peltonen J. T. , Pekola J. P. 
Published: February 2017

AbstractWe determine the thermal conductance of thin niobium (Nb) wires on a silica substrate in the temperature range of 0.1–0.6 K using electron thermometry based on normal metal-insulator-superconductor tunnel junctions. We find that at 0.6 K, the thermal conductance of Nb is two orders of magnitude lower than that of Al in the superconducting state, and two orders of magnitude below the Wiedemann-Franz conductance calculated with the normal state resistance of the wire. The measured thermal conductance exceeds the prediction of the Bardeen-Cooper-Schrieffer theory, and demonstrates a power law dependence on temperature as T4.5, instead of an exponential one. At the same time, we monitor the temperature profile of the substrate along the Nb wire to observe possible overheating of the phonon bath. We show that Nb can be successfully used for thermal insulation in a nanoscale circuit while simultaneously providing an electrical connection.
Failure and recovery in dynamical networks
Authors: Böttcher L. , Luković M. , Nagler J. , Havlin S. , Herrmann H. J. 
Published: February 2017

AbstractFailure, damage spread and recovery crucially underlie many spatially embedded networked systems ranging from transportation structures to the human body. Here we study the interplay between spontaneous damage, induced failure and recovery in both embedded and non-embedded networks. In our model the network’s components follow three realistic processes that capture these features: (i) spontaneous failure of a component independent of the neighborhood (internal failure), (ii) failure induced by failed neighboring nodes (external failure) and (iii) spontaneous recovery of a component. We identify a metastable domain in the global network phase diagram spanned by the model’s control parameters where dramatic hysteresis effects and random switching between two coexisting states are observed. This dynamics depends on the characteristic link length of the embedded system. For the Euclidean lattice in particular, hysteresis and switching only occur in an extremely narrow region of the parameter space compared to random networks. We develop a unifying theory which links the dynamics of our model to contact processes. Our unifying framework may help to better understand controllability in spatially embedded and random networks where spontaneous recovery of components can mitigate spontaneous failure and damage spread in dynamical networks.
A seed-expanding method based on random walks for community detection in networks with ambiguous community structures
Authors: Su Yansen , Wang Bangju , Zhang Xingyi 
Published: February 2017

AbstractCommunity detection has received a great deal of attention, since it could help to reveal the useful information hidden in complex networks. Although most previous modularity-based and local modularity-based community detection algorithms could detect strong communities, they may fail to exactly detect several weak communities. In this work, we define a network with clear or ambiguous community structures based on the types of its communities. A seed-expanding method based on random walks is proposed to detect communities for networks, especially for the networks with ambiguous community structures. We identify local maximum degree nodes, and detect seed communities in a network. Then, the probability of a node belonging to each community is calculated based on the total probability model and random walks, and each community is expanded by repeatedly adding the node which is most likely to belong to it. Finally, we use the community optimization method to ensure that each node is in a community. Experimental results on both computer-generated and real-world networks demonstrate that the quality of the communities detected by the proposed algorithm is superior to the- state-of-the-art algorithms in the networks with ambiguous community structures.
Molecular mutagenesis of ppGpp: turning a RelA activator into an inhibitor
Authors: Beljantseva Jelena , Kudrin Pavel , Jimmy Steffi , Ehn Marcel , Pohl Radek , Varik Vallo , Tozawa Yuzuru , Shingler Victoria , Tenson Tanel , Rejman Dominik , Hauryliuk Vasili 
Published: February 2017

AbstractThe alarmone nucleotide (p)ppGpp is a key regulator of bacterial metabolism, growth, stress tolerance and virulence, making (p)ppGpp-mediated signaling a promising target for development of antibacterials. Although ppGpp itself is an activator of the ribosome-associated ppGpp synthetase RelA, several ppGpp mimics have been developed as RelA inhibitors. However promising, the currently available ppGpp mimics are relatively inefficient, with IC50 in the sub-mM range. In an attempt to identify a potent and specific inhibitor of RelA capable of abrogating (p)ppGpp production in live bacterial cells, we have tested a targeted nucleotide library using a biochemical test system comprised of purified Escherichia coli components. While none of the compounds fulfilled this aim, the screen has yielded several potentially useful molecular tools for biochemical and structural work.
Antiferromagnetic Kondo lattice compound CePt3P
Authors: Chen Jian , Wang Zhen , Zheng Shiyi , Feng Chunmu , Dai Jianhui , Xu Zhu’an 
Published: February 2017

AbstractA new ternary platinum phosphide CePt3P was synthesized and characterized by means of magnetic, thermodynamic and transport measurements. The compound crystallizes in an antiperovskite tetragonal structure similar to that in the canonical family of platinum-based superconductors APt3P (A = Sr, Ca, La) and closely related to the noncentrosymmetric heavy fermion superconductor CePt3Si. In contrast to all the superconducting counterparts, however, no superconductivity is observed in CePt3P down to 0.5 K. Instead, CePt3P displays a coexistence of antiferromagnetic ordering, Kondo effect and crystalline electric field effect. A field-induced spin-flop transition is observed below the magnetic ordering temperature TN1 of 3.0 K while the Kondo temperature is of similar magnitude as TN1. The obtained Sommerfeld coefficient of electronic specific heat is γCe = 86 mJ/mol·K2 indicating that CePt3P is a moderately correlated antiferromagnetic Kondo lattice compound.
Hysteretic photochromic switching of Eu-Mg defects in GaN links the shallow transient and deep ground states of the Mg acceptor
Authors: Singh A. K. , O’Donnell K. P. , Edwards P. R. , Lorenz K. , Kappers M. J. , Boćkowski M. 
Published: February 2017

AbstractAlthough p-type activation of GaN by Mg underpins a mature commercial technology, the nature of the Mg acceptor in GaN is still controversial. Here, we use implanted Eu as a ‘spectator ion’ to probe the lattice location of Mg in doubly doped GaN(Mg):Eu. Photoluminescence spectroscopy of this material exemplifies hysteretic photochromic switching (HPS) between two configurations, Eu0 and Eu1(Mg), of the same Eu-Mg defect, with a hyperbolic time dependence on ‘switchdown’ from Eu0 to Eu1(Mg). The sample temperature and the incident light intensity at 355 nm tune the characteristic switching time over several orders of magnitude, from less than a second at 12.5 K, ~100 mW/cm2 to (an estimated) several hours at 50 K, 1 mW/cm2. Linking the distinct Eu-Mg defect configurations with the shallow transient and deep ground states of the Mg acceptor in the Lany-Zunger model, we determine the energy barrier between the states to be 27.7(4) meV, in good agreement with the predictions of theory. The experimental results further suggest that at low temperatures holes in deep ground states are localized on N atoms axially bonded to Mg acceptors.
The molecular basis of talin2’s high affinity toward β1-integrin
Authors: Yuan Yaxia , Li Liqing , Zhu Yanyan , Qi Lei , Azizi Latifeh , Hytönen Vesa P. , Zhan Chang-Guo , Huang Cai 
Published: February 2017

AbstractTalin interacts with β-integrin tails and actin to control integrin activation, thus regulating focal adhesion dynamics and cell migration. There are two talin genes, Tln1 and Tln2, which encode talin1 and talin2, and it is generally believed that talin2 functions redundantly with talin1. However, we show here that talin2 has a higher affinity to β1-integrin tails than talin1. Mutation of talin2 S339 to leucine, which can cause Fifth Finger Camptodactyly, a human genetic disease, completely disrupted its binding to β–integrin tails. Also, substitution of talin1 C336 with Ser enhanced the affinity of talin1, whereas substitution of talin2 S339 with Cys diminished that of talin2. Further computational modeling analysis shows that talin2 S339 formed a hydrogen bond with E353, which is critical for inducing key hydrogen bonds between talin2 N326 and β1-integrin R760, and between talin2 K327 and β1-integrin D759. Mutation at any of these residues significantly diminished the interaction of talin2 with β1- integrin tails. These hydrogen bonds were not observed in talin1/β1-integrin, but did exist in talin1C336S/β1-integrin complex. These results suggest that talin2 S339 forms a hydrogen bond with E353 to mediate its high affinity to β1-integrin.
Promoting Cas9 degradation reduces mosaic mutations in non-human primate embryos
Authors: Tu Zhuchi , Yang Weili , Yan Sen , Yin An , Gao Jinquan , Liu Xudong , Zheng Yinghui , Zheng Jiezhao , Li Zhujun , Yang Su , Li Shihua , Guo Xiangyu , Li Xiao-Jiang 
Published: February 2017

AbstractCRISPR-Cas9 is a powerful new tool for genome editing, but this technique creates mosaic mutations that affect the efficiency and precision of its ability to edit the genome. Reducing mosaic mutations is particularly important for gene therapy and precision genome editing. Although the mechanisms underlying the CRSIPR/Cas9-mediated mosaic mutations remain elusive, the prolonged expression and activity of Cas9 in embryos could contribute to mosaicism in DNA mutations. Here we report that tagging Cas9 with ubiquitin-proteasomal degradation signals can facilitate the degradation of Cas9 in non-human primate embryos. Using embryo-splitting approach, we found that shortening the half-life of Cas9 in fertilized zygotes reduces mosaic mutations and increases its ability to modify genomes in non-human primate embryos. Also, injection of modified Cas9 in one-cell embryos leads to live monkeys with the targeted gene modifications. Our findings suggest that modifying Cas9 activity can be an effective strategy to enhance precision genome editing.
Effects of Specific Language Impairment (SLI) and bilingualism on verbal short-term memory
Authors: Meir Natalia 
Published: February 2017

Abstract
The current study assessed independent and combined effects of SLI and bilingualism on tasks tapping into verbal short-term memory (vSTM) with varying linguistic load in two languages (Russian and Hebrew). The study explored the extent to which the presence of SLI is related to limited vSTM storage and bilingualism is associated with reduced vocabulary size.
A total of 190 monolingual and bilingual children aged 5;5–6;8 participated in the current study: 108 sequential Russian-Hebrew bilinguals (18 with SLI), 48 Hebrew monolinguals (13 with SLI) and 34 Russian monolinguals (14 with SLI). Children performed three repetition tasks: forward-digit span (FWD), non-word repetition (NWR) and sentence repetition (SRep); bilingual children were tested in both of their languages.
Results indicated a negative effect of SLI on all experimental tasks tapping into vSTM. The effect of SLI rose as a function of increased linguistic load. Regarding bilingualism, no effect was found on the measure of vSTM with the lowest linguistic load (FWD), while its effect was robust once the linguistic load was increased (SRep). The results reported in this study bring evidence that lower performance on measures of vSTM in children with SLI and bilingual children stem from different sources. Although, children with SLI have limitations of vSTM, deficient vSTM cannot fully account for the linguistic difficulties observed in children with SLI. As for bilingualism, it does not affect verbal storage when the linguistic load is minimal, while poor performance in bilingual children on tasks with greater linguistic load is attributed to smaller vocabulary sizes.
The changing face of α Centauri B: probing plage and stellar activity in K dwarfs
Authors: Thompson A. P. G. , Watson C. A. , de Mooij E. J. W. , Jess D. B. 
Published: February 2017

Abstract
Detailed knowledge of stellar activity is crucial for understanding stellar dynamos, as well as pushing exoplanet radial-velocity detection limits towards Earth analogue confirmation. We directly compare archival High Accuracy Radial velocity Planet Searcher spectra taken at the minimum in α Cen B’s activity cycle to a high-activity state when clear rotational modulation of $\log {R^{\prime }_{HK}}$ is visible. Relative to the inactive spectra, we find a large number of narrow pseudo-emission features in the active spectra with strengths that are rotationally modulated. These features most likely originate from plage, spots or a combination of both. They also display radial velocity variations of ∼300 m s−1 – consistent with an active region rotating across the stellar surface. Furthermore, we see evidence that some of the lines originating from the ‘active immaculate’ photosphere appear broader relative to the ‘inactive immaculate’ case. This may be due to enhanced contributions of, for example, magnetic bright points to these lines, which then causes additional line broadening. More detailed analysis may enable measurements of plage and spot coverage using single spectra in the future.
The Interlenticulostriate Approach to Very High-Riding Distal Basilar Trunk Aneurysms
Authors: Rahme Ralph , Kurbanov Almaz , Keller Jeffrey T. , Abruzzo Todd A. , Jimenez Lincoln , Ringer Andrew J. , Choutka Ondrej , Zuccarello Mario 
Published: February 2017

Abstract

BACKGROUND: Most high-riding distal basilar trunk aneurysms can be surgically approached via the transsylvian route and its orbitozygomatic variant. However, on rare occasions, the basilar bifurcation may be unusually high and an approach above the carotid terminus may be required.

OBJECTIVE: In this cadaveric study, we sought to determine the feasibility and exposure limits of the interlenticulostriate approach (ILSA).

METHODS: A standard transsylvian approach was performed in 10 cerebral hemispheres of 5 formalin-fixed, silicone-injected cadaver heads. The interpeduncular cistern was exposed via the opticocarotid window, carotid-oculomotor window, and supracarotid ILSA window. The latter was measured and an aneurysm clip or ventriculostomy stylet was placed as high as possible through each corridor. Using noncontrast 3-D rotational angiography, clip/stylet positions were measured relative to the dorsum sellae.

RESULTS: ILSA provided a 9.4 × 4.6 mm mean surgical corridor, just enough room for a standard clip applier. This space was limited by the carotid bifurcation inferiorly, the lenticulostriate arteries medially and laterally, and the optic tract superiorly. There was no difference between opticocarotid and carotid-oculomotor windows, in terms of clip position (+8.9 vs +8.6 mm, respectively; P = .78). In contrast, ILSA provided significantly improved superior exposure, compared with either approaches (mean stylet position: +14.3 mm; P = .005). The exposure benefit afforded by ILSA was consistent across all 10 hemispheres, ranging from +2.5 to +8 mm.

CONCLUSION: For high-riding distal basilar trunk aneurysms that cannot be reached via the frontotemporal orbitozygomatic approach, ILSA can provide a viable route of access. Vascular neurosurgeons should be familiarized with this approach.
Superficial Temporal Artery: Distal Posterior Cerebral Artery Bypass through the Subtemporal Approach: Technical Note and Pilot Surgical Cases
Authors: Kawashima Akitsugu , Andrade-Barazarte Hugo , Jahromi Behnam Rezai , Oinas Minna , Elsharkawy Ahmed , Kivelev Juri , Kubota Yuichi , Kawamata Takakazu , Hernesniemi Juha A. 
Published: February 2017

Abstract

BACKGROUND: Posterior cerebral artery (PCA) aneurysms are rare and the majority are fusiform in shape. Proximal occlusion of PCA represents a treatment option for these lesions. However, this procedure carries a high risk of ischemic complications.

OBJECTIVE: To describe the technique of trapping a fusiform PCA aneurysm and revascularization of the distal PCA using a superficial temporal artery (STA) graft through the same microsurgical approach.

METHODS: From September 2012 to October 2014, we retrospectively identified 3 patients harboring a fusiform PCA aneurysm (P2 segment aneurysm) who underwent trapping of the aneurysm and reconstruction of the distal PCA through the same subtemporal approach. We analyzed immediate morbidity, surgical complications, and the patency of the bypass to determine the feasibility of this procedure.

RESULTS: All 3 patients underwent successful trapping of the fusiform PCA aneurysm and revascularization of the distal PCA. The origin of P3 segment or posterior temporal artery (PTA) served as recipient arteries. In all 3 cases, adequate blood flow was evident after performing the STA-P3/PTA bypass. None of the patients experienced a new permanent neurological deficit. At 1-year follow-up, the STA-PTA/PCA bypasses remained patent.

CONCLUSION: The STA-P3/PTA bypass through the subtemporal approach is a feasible option to maintain blood flow in cases of PCA fusiform aneurysms requiring trapping of the P2 segment.
A SURVEILLANCE SYSTEM FOR ASSESSING HEALTH EFFECTS FROM HAZARDOUS EXPOSURES
Authors: HARDY ROBERT J. , SCHRODER GENE D. , COOPER SHARON P. , BUFFLER PATRICIA A. , PRICHARD HOWARD M. , CRANE MARTIN 
Published: February 2017

Abstract
A statistical procedure for monitoring the health status of a community potentially exposed to a hazardous environment is presented. It utilizes two levels of investigation. Level I studies monitor routinely collected vital statistics and routes of community exposure whereas level II studies require additional data collection and are further distinguished by their design and duration. In a level I study, routine vital statistics for specified end points over a specified period of time are monitored, and the observed number of events is compared with the expected number of events for a given population. The statistical model used with this procedure employs a two-step decision rule based on the standardized mortality ratio for the study community. An “alert status” is invoked when the number of events exceeds a prescribed excess. An “action status” is indicated if the excess noted in the initial period persists or if the observed number of events in the initial period greatly exceeds expectation. Should an “action status” be justified, level II studies to determine the likely explanation for the significant excess are initiated. This could include the conduct of a “case-control” study using the exposure data available from monitoring the community.