bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcriptional pausing at the translation start site operates as a critical checkpoint for riboswitch regulation
Authors: Chauvier Adrien , Picard-Jean Frédéric , Berger-Dancause Jean-Christophe , Bastet Laurène , Naghdi Mohammad Reza , Dubé Audrey , Turcotte Pierre , Perreault Jonathan , Lafontaine Daniel A.
Published: January 2017

On the basis of nascent transcript sequencing, it has been postulated but never demonstrated that transcriptional pausing at translation start sites is important for gene regulation. Here we show that the Escherichia coli thiamin pyrophosphate (TPP) thiC riboswitch contains a regulatory pause site in the translation initiation region that acts as a checkpoint for thiC expression. By biochemically probing nascent transcription complexes halted at defined positions, we find a narrow transcriptional window for metabolite binding, in which the downstream boundary is delimited by the checkpoint. We show that transcription complexes at the regulatory pause site favour the formation of a riboswitch intramolecular lock that strongly prevents TPP binding. In contrast, cotranscriptional metabolite binding increases RNA polymerase pausing and induces Rho-dependent transcription termination at the checkpoint. Early transcriptional pausing may provide a general mechanism, whereby transient transcriptional windows directly coordinate the sensing of environmental cues and bacterial mRNA regulation.
Spaceflight-induced neuroplasticity in humans as measured by MRI: what do we know so far?
Authors: Van Ombergen Angelique , Laureys Steven , Sunaert Stefan , Tomilovskaya Elena , Parizel Paul M. , Wuyts Floris L.
Published: January 2017

Space travel poses an enormous challenge on the human body; microgravity, ionizing radiation, absence of circadian rhythm, confinement and isolation are just some of the features associated with it. Obviously, all of the latter can have an impact on human physiology and even induce detrimental changes. Some organ systems have been studied thoroughly under space conditions, however, not much is known on the functional and morphological effects of spaceflight on the human central nervous system. Previous studies have already shown that central nervous system changes occur during and after spaceflight in the form of neurovestibular problems, alterations in cognitive function and sensory perception, cephalic fluid shifts and psychological disturbances. However, little is known about the underlying neural substrates. In this review, we discuss the current limited knowledge on neuroplastic changes in the human central nervous system associated with spaceflight (actual or simulated) as measured by magnetic resonance imaging-based techniques. Furthermore, we discuss these findings as well as their future perspectives, since this can encourage future research into this delicate and intriguing aspect of spaceflight. Currently, the literature suffers from heterogeneous experimental set-ups and therefore, the lack of comparability of findings among studies. However, the cerebellum, cortical sensorimotor and somatosensory areas and vestibular-related pathways seem to be involved across different studies, suggesting that these brain regions are most affected by (simulated) spaceflight. Extending this knowledge is crucial, especially with the eye on long-duration interplanetary missions (e.g. Mars) and space tourism.
Digestive and appendicular soft-parts, with behavioural implications, in a large Ordovician trilobite from the Fezouata Lagerstätte, Morocco
Authors: Gutiérrez-Marco Juan C. , García-Bellido Diego C. , Rábano Isabel , Sá Artur A.
Published: January 2017

Trilobites were one of the most successful groups of marine arthropods during the Palaeozoic era, yet their soft-part anatomy is only known from a few exceptionally-preserved specimens found in a handful of localities from the Cambrian to the Devonian. This is because, even if the sclerotized appendages were not destroyed during early taphonomic stages, they are often overprinted by the three-dimensional, mineralised exoskeleton. Inferences about the ventral anatomy and behavioural activities of trilobites can also be derived from the ichnological record, which suggests that mostCruzianaandRusophycustrace fossils were possibly produced by the actions of trilobites. Three specimens of the asaphid trilobiteMegistaspis (Ekeraspis) hammondi, have been discovered in the Lower Ordovician Fezouata Konservat-Lagerstätte of southern Morocco, preserving appendages and digestive tract. The digestive structures include a crop with digestive caeca, while the appendages display exopodal setae and slight heteropody (cephalic endopods larger and more spinose than thoracic and pygidial ones). The combination of these digestive structures and the heteropody has never been described together among trilobites, and the latter could assist in the understanding of the production of certain comb-like traces of theCruziana rugosagroup, which are extraordinarily abundant on the shallow marine shelves around Gondwana.
Use of Fibonacci numbers in lipidomics – Enumerating various classes of fatty acids
Authors: Schuster Stefan , Fichtner Maximilian , Sasso Severin
Published: January 2017

In lipid biochemistry, a fundamental question is how the potential number of fatty acids increases with their chain length. Here, we show that it grows according to the famous Fibonacci numbers when cis/trans isomerism is neglected. Since the ratio of two consecutive Fibonacci numbers tends to the Golden section, 1.618, organisms can increase fatty acid variability approximately by that factor per carbon atom invested. Moreover, we show that, under consideration of cis/trans isomerism and/or of modification by hydroxy and/or oxo groups, diversity can be described by generalized Fibonacci numbers (e.g. Pell numbers). For the sake of easy comprehension, we deliberately build the proof on the recursive definitions of these number series. Our results should be of interest for mass spectrometry, combinatorial chemistry, synthetic biology, patent applications, use of fatty acids as biomarkers and the theory of evolution. The recursive definition of Fibonacci numbers paves the way to construct all structural formulas of fatty acids in an automated way.
Determining the relative contribution of retinal disparity and blur cues to ocular accommodation in Down syndrome
Authors: Doyle Lesley , Saunders Kathryn J. , Little Julie-Anne
Published: January 2017

Individuals with Down syndrome (DS) often exhibit hypoaccommodation alongside accurate vergence. This study investigates the sensitivity of the two systems to retinal disparity and blur cues, establishing the relationship between the two in terms of accommodative-convergence to accommodation (AC/A) and convergence-accommodation to convergence (CA/C) ratios. An objective photorefraction system measured accommodation and vergence under binocular conditions and when retinal disparity and blur cues were removed. Participants were aged 6–16 years (DS n = 41, controls n = 76). Measures were obtained from 65.9% of participants with DS and 100% of controls. Accommodative and vergence responses were reduced with the removal of one or both cues in controls (p < 0.007). For participants with DS, removal of blur was less detrimental to accommodative responses than removal of disparity; accommodative responses being significantly better when all cues were available or when blur was removed in comparison to when proximity was the only available cue. AC/A ratios were larger and CA/C ratios smaller in participants with DS (p < 0.00001). This study demonstrates that retinal disparity is the main driver to both systems in DS and illustrates the diminished influence of retinal blur. High AC/A and low CA/C ratios in combination with disparity-driven responses suggest prioritisation of vergence over accurate accommodation.
Polychlorinated biphenyls target Notch/Dll and VEGF R2 in the mouse placenta and human trophoblast cell lines for their anti-angiogenic effects
Authors: Kalkunte Satyan , Huang Zheping , Lippe Eliana , Kumar Sunil , Robertson Larry W. , Sharma Surendra
Published: January 2017

The intrauterine environment is particularly vulnerable to environmental exposures. We previously established a mouse model that provided evidence for pregnancy complications and placental anti-angiogenesis in response to Aroclor 1254 (A-1254), a mixture of polychlorinated biphenyls (PCBs). Importantly, these effects were observed in IL-10−/−, but not wild type, mice, suggesting that IL-10 deficiency predisposes to pregnancy disruptive effects of environmental toxicants. However, the mechanisms by which PCBs cause anti-angiogenic effects are unclear. Here, we evaluated PCB-mediated anti-angiogenic effects by diverse but complementary approaches, including HUVEC-mediated trophoblast invasion in nude mice, in vitro three-dimensional capillary tube formation involving HUVEC and/or HTR8 trophoblasts, and aortic ring endothelial cell outgrowth/sprouting. Taken together, our data suggest that PCBs act as potent anti-angiogenic agents. Importantly, we show that treatment of pregnant IL-10−/− mice with A-1254 resulted in placental activation of the Notch/Delta-like ligand (Dll) pathway, a master regulator of cell-cell interaction and vascular patterning. Similar results were obtained with HUVEC and HTR8 trophoblasts. Rescue of A-1254-induced disruption of HUVEC-based tube formation by γ-secretase inhibitor L1790 confirmed the critical role of the Notch/Dll pathway. Our data suggest that PCBs impart pregnancy disruptive functions by activating the Notch/Dll pathway and by inducing anti-angiogenic effects at the maternal-fetal interface.
Novel long-chain compounds with both immunomodulatory and MenA inhibitory activities against Staphylococcus aureus and its biofilm
Authors: Choi Seoung-ryoung , Frandsen Joel , Narayanasamy Prabagaran
Published: January 2017

Menaquinone (MK) biosynthesis pathway is a potential target for evaluating antimicrobials in gram-positive bacteria. Here, 1,4-dihydroxy-2-naphthoate prenyltransferase (MenA) was targeted to reduce methicillin-resistantStaphylococcus aureus(MRSA) growth. MenA inhibiting, long chain-based compounds were designed, synthesized and evaluated against MRSA and menaquinone utilizing bacteria in aerobic conditions. The results showed that these bacteria were susceptible to most of the compounds. Menaquinone (MK-4) supplementation rescued MRSA growth, suggesting these compounds inhibit MK biosynthesis.3aand7cexhibited promising inhibitory activities with MICs ranging 1–8 μg/mL against MRSA strains. The compounds did not facilitate small colony variant formation. These compounds also inhibited the biofilm growth by MRSA at high concentration. Compounds3a,6band7cdisplayed a promising extracellular bactericidal activity against MRSA at concentrations equal to and four-fold less than their respective MICs. We also observed cytokines released from THP-1 macrophages treated with compounds3a,6band7cand found decreases in TNF-α and IL-6 release and increase in IL-1β. These data provide evidence that MenA inhibitors act as TNF-α and IL-6 inhibitors, raising the potential for development and application of these compounds as potential immunomodulatory agents.
Towards an emotional ‘stress test’: a reliable, non-subjective cognitive measure of anxious responding
Authors: Aylward Jessica , Robinson Oliver J.
Published: January 2017

Response to stress or external threats is a key factor in mood and anxiety disorder aetiology. Current measures of anxious responding to threats are limited because they largely rely on retrospective self-report. Objectively quantifying individual differences in threat response would be a valuable step towards improving our understanding of anxiety disorder vulnerability. Our goal is to therefore develop a reliable, objective, within-subject ‘stress-test’ of anxious responding. To this end, we examined threat-potentiated performance on an inhibitory control task from baseline to 2–4 weeks (n = 50) and again after 5–9 months (n = 22). We also describe single session data for a larger sample (n = 157) to provide better population-level estimates of task performance variance. Replicating previous findings, threat of shock improved distractor accuracy and slowed target reaction time on our task. Critically, both within-subject self-report measures of anxiety (ICC = 0.66) and threat-potentiated task performance (ICC = 0.58) showed clinically useful test-retest reliability. Threat-potentiated task performance may therefore hold promise as a non-subjective measure of individual anxious responding.
Experimental Array for Generating Dual Circularly-Polarized Dual-Mode OAM Radio Beams
Authors: Bai Xu-Dong , Liang Xian-Ling , Sun Yun-Tao , Hu Peng-Cheng , Yao Yu , Wang Kun , Geng Jun-Ping , Jin Rong-Hong
Published: January 2017

Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams are of complicated structure and very high cost. This paper provides an effective solution of generating dual circularly-polarized (CP) dual-mode OAM beams. The antenna consists of four dual-CP elements which are sequentially rotated 90 degrees in the clockwise direction. Different from all previous published research relating to OAM generation by phased arrays, the four elements are fed with the same phase for both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The dual-mode operation for OAM is achieved through the opposite phase differences generated for LHCP and RHCP, when the dual-CP elements are sequentially rotated in the clockwise direction. The measured results coincide well with the simulated ones, which verified the effectiveness of the proposed design.
The Content of Imagined Sounds Changes Visual Motion Perception in the Cross-Bounce Illusion
Authors: Berger Christopher C. , Ehrsson H. Henrik
Published: January 2017

Can what we imagine hearing change what we see? Whether imagined sensory stimuli are integrated with external sensory stimuli to shape our perception of the world has only recently begun to come under scrutiny. Here, we made use of the cross-bounce illusion in which an auditory stimulus presented at the moment two passing objects meet promotes the perception that the objects bounce off rather than cross by one another to examine whether the content of imagined sound changes visual motion perception in a manner that is consistent with multisensory integration. The results from this study revealed that auditory imagery of a sound with acoustic properties typical of a collision (i.e., damped sound) promoted the bounce-percept, but auditory imagery of the same sound played backwards (i.e., ramped sound) did not. Moreover, the vividness of the participants’ auditory imagery predicted the strength of this imagery-induced illusion. In a separate experiment, we ruled out the possibility that changes in attention (i.e., sensitivity index d′) or response bias (response bias index c) were sufficient to explain this effect. Together, these findings suggest that this imagery-induced multisensory illusion reflects the successful integration of real and imagined cross-modal sensory stimuli, and more generally, that what we imagine hearing can change what we see.
Variation in short-term and long-term responses of photosynthesis and isoprenoid-mediated photoprotection to soil water availability in four Douglas-fir provenances
Authors: Junker Laura Verena , Kleiber Anita , Jansen Kirstin , Wildhagen Henning , Hess Moritz , Kayler Zachary , Kammerer Bernd , Schnitzler Jörg-Peter , Kreuzwieser Jürgen , Gessler Arthur , Ensminger Ingo
Published: January 2017

For long-lived forest tree species, the understanding of intraspecific variation among populations and their response to water availability can reveal their ability to cope with and adapt to climate change. Dissipation of excess excitation energy, mediated by photoprotective isoprenoids, is an important defense mechanism against drought and high light when photosynthesis is hampered. We used 50-year-old Douglas-fir trees of four provenances at two common garden experiments to characterize provenance-specific variation in photosynthesis and photoprotective mechanisms mediated by essential and non-essential isoprenoids in response to soil water availability and solar radiation. All provenances revealed uniform photoprotective responses to high solar radiation, including increased de-epoxidation of photoprotective xanthophyll cycle pigments and enhanced emission of volatile monoterpenes. In contrast, we observed differences between provenances in response to drought, where provenances sustaining higher CO2assimilation rates also revealed increased water-use efficiency, carotenoid-chlorophyll ratios, pools of xanthophyll cycle pigments, β-carotene and stored monoterpenes. Our results demonstrate that local adaptation to contrasting habitats affected chlorophyll-carotenoid ratios, pool sizes of photoprotective xanthophylls, β-carotene, and stored volatile isoprenoids. We conclude that intraspecific variation in isoprenoid-mediated photoprotective mechanisms contributes to the adaptive potential of Douglas-fir provenances to climate change.
Plasma heme-induced renal toxicity is related to a capillary rarefaction
Authors: Tabibzadeh Nahid , Estournet Céline , Placier Sandrine , Perez Joëlle , Bilbault Héloïse , Girshovich Alexis , Vandermeersch Sophie , Jouanneau Chantal , Letavernier Emmanuel , Hammoudi Nadjib , Lionnet François , Haymann Jean-Philippe
Published: January 2017

Severe hypertension can lead to malignant hypertension (MH) with renal thrombotic microangiopathy and hemolysis. The role of plasma heme release in this setting is unknown. We aimed at evaluating the effect of a mild plasma heme increase by hemin administration in angiotensin II (AngII)-mediated hypertensive rats. Prevalence of MH and blood pressure values were similar in AngII and AngII + hemin groups. MH rats displayed a decreased renal blood flow (RBF), increased renal vascular resistances (RVR), and increased aorta and interlobar arteries remodeling with a severe renal microcirculation assessed by peritubular capillaries (PTC) rarefaction. Hemin-treated rats with or without AngII displayed also a decreased RBF and increased RVR explained only by PCT rarefaction. In AngII rats, RBF was similar to controls (with increased RVR). PTC density appeared strongly correlated to tubular damage score (rho = −0.65, p < 0.0001) and also renal Heme Oygenase-1 (HO-1) mRNA (rho = −0.67, p < 0.0001). HO-1 was expressed in PTC and renal tubules in MH rats, but only in PTC in other groups. In conclusion, though increased plasma heme does not play a role in triggering or aggravating MH, heme release appears as a relevant toxic mediator leading to renal impairment, primarily through PTC endothelial dysfunction rather than direct tubular toxicity.
Generation of germline ablated male pigs by CRISPR/Cas9 editing of the NANOS2 gene
Authors: Park Ki-Eun , Kaucher Amy V. , Powell Anne , Waqas Muhammad Salman , Sandmaier Shelley E.S. , Oatley Melissa J. , Park Chi-Hun , Tibary Ahmed , Donovan David M. , Blomberg Le Ann , Lillico Simon G. , Whitelaw C. Bruce A. , Mileham Alan , Telugu Bhanu P. , Oatley Jon M.
Published: January 2017

Genome editing tools have revolutionized the generation of genetically modified animals including livestock. In particular, the domestic pig is a proven model of human physiology and an agriculturally important species. In this study, we utilized the CRISPR/Cas9 system to edit theNANOS2gene in pig embryos to generate offspring with mono-allelic and bi-allelic mutations. We found thatNANOS2knockout pigs phenocopy knockout mice with male specific germline ablation but other aspects of testicular development are normal. Moreover, male pigs with one intactNANOS2allele and female knockout pigs are fertile. From an agriculture perspective,NANOS2knockout male pigs are expected to serve as an ideal surrogate for transplantation of donor spermatogonial stem cells to expand the availability of gametes from genetically desirable sires.
In-gap corner states in core-shell polygonal quantum rings
Authors: Sitek Anna , Ţolea Mugurel , Niţă Marian , Serra Llorenç , Gudmundsson Vidar , Manolescu Andrei
Published: January 2017

We study Coulomb interacting electrons confined in polygonal quantum rings. We focus on the interplay of localization at the polygon corners and Coulomb repulsion. Remarkably, the Coulomb repulsion allows the formation of in-gap states, i.e., corner-localized states of electron pairs or clusters shifted to energies that were forbidden for non-interacting electrons, but below the energies of corner-side-localized states. We specify conditions allowing optical excitation to those states.
MicroPattern: a web-based tool for microbe set enrichment analysis and disease similarity calculation based on a list of microbes
Authors: Ma Wei , Huang Chuanbo , Zhou Yuan , Li Jianwei , Cui Qinghua
Published: January 2017

The microbiota colonized on human body is renowned as “a forgotten organ” due to its big impacts on human health and disease. Recently, microbiome studies have identified a large number of microbes differentially regulated in a variety of conditions, such as disease and diet. However, methods for discovering biological patterns in the differentially regulated microbes are still limited. For this purpose, here, we developed a web-based tool named MicroPattern to discover biological patterns for a list of microbes. In addition, MicroPattern implemented and integrated an algorithm we previously presented for the calculation of disease similarity based on disease-microbe association data. MicroPattern first grouped microbes into different sets based on the associated diseases and the colonized positions. Then, for a given list of microbes, MicroPattern performed enrichment analysis of the given microbes on all of the microbe sets. Moreover, using MicroPattern, we can also calculate disease similarity based on the shared microbe associations. Finally, we confirmed the accuracy and usefulness of MicroPattern by applying it to the changed microbes under the animal-based diet condition. MicroPattern is freely available at http://www.cuilab.cn/micropattern.
Tomato progeny inherit resistance to the nematode Meloidogyne javanica linked to plant growth induced by the biocontrol fungus Trichoderma atroviride
Authors: Medeiros Hugo Agripino de , Araújo Filho Jerônimo Vieira de , Freitas Leandro Grassi de , Castillo Pablo , Rubio María Belén , Hermosa Rosa , Monte Enrique
Published: January 2017

Root-knot nematodes (RKN) are major crop pathogens worldwide. Trichoderma genus fungi are recognized biocontrol agents and a direct activity of Trichoderma atroviride (Ta) against the RKN Meloidogyne javanica (Mj), in terms of 42% reduction of number of galls (NG), 60% of number of egg masses and 90% of number of adult nematodes inside the roots, has been observed in tomato grown under greenhouse conditions. An in vivo split-root designed experiment served to demonstrate that Ta induces systemic resistance towards Mj, without the need for the organisms to be in direct contact, and significantly reduces NG (20%) and adult nematodes inside tomato roots (87%). The first generation (F1) of Ta-primed tomato plants inherited resistance to RKN; although, the induction of defenses occurred through different mechanisms, and in varying degrees, depending on the Ta-Mj interaction. Plant growth promotion induced by Ta was inherited without compromising the level of resistance to Mj, as the progeny of Ta-primed plants displayed increased size and resistance to Mj without fitness costs. Gene expression results from the defense inductions in the offspring of Ta-primed plants, suggested that an auxin-induced reactive oxygen species production promoted by Ta may act as a major defense strategy during plant growth.
Comparative mitochondrial genomics toward exploring molecular markers in the medicinal fungus Cordyceps militaris
Authors: Zhang Shu , Hao Ai-Jing , Zhao Yu-Xiang , Zhang Xiao-Yu , Zhang Yong-Jie
Published: January 2017

Cordyceps militarisis a fungus used for developing health food, but knowledge about its intraspecific differentiation is limited due to lack of efficient markers. Herein, we assembled the mitochondrial genomes of eightC. militarisstrains and performed a comparative mitochondrial genomic analysis together with three previously reported mitochondrial genomes of the fungus. Sizes of the 11 mitochondrial genomes varied from 26.5 to 33.9 kb mainly due to variable intron contents (from two to eight introns per strain). Nucleotide variability varied according to different regions with non-coding regions showing higher variation frequency than coding regions. Recombination events were identified between some locus pairs but seemed not to contribute greatly to genetic variations of the fungus. Based on nucleotide diversity fluctuations across the alignment of all mitochondrial genomes, molecular markers with the potential to be used for future typing studies were determined.
High fat diet-induced changes of mouse hepatic transcription and enhancer activity can be reversed by subsequent weight loss
Authors: Siersbæk Majken , Varticovski Lyuba , Yang Shutong , Baek Songjoon , Nielsen Ronni , Mandrup Susanne , Hager Gordon L. , Chung Jay H. , Grøntved Lars
Published: January 2017

Epigenetic factors have been suggested to play an important role in metabolic memory by trapping and maintaining initial metabolic changes within the transcriptional regulatory machinery. In this study we fed mice a high fat diet (HFD) for seven weeks followed by additional five weeks of chow, to identify HFD-mediated changes to the hepatic transcriptional program that may persist after weight loss. Mice fed a HFD displayed increased fasting insulin levels, hepatosteatosis and major changes in hepatic gene transcription associated with modulation of H3K27Ac at enhancers, but no significant changes in chromatin accessibility, indicating that HFD-regulated gene transcription is primarily controlled by modulating the activity of pre-established enhancers. After return to the same body weight as chow fed control mice, the fasting insulin, glucose, and hepatic triglyceride levels were fully restored to normal levels. Moreover, HFD-regulated H3K27Ac and mRNA levels returned to similar levels as control mice. These data demonstrates that the transcription regulatory landscape in the liver induced by HFD is highly dynamic and can be reversed by weight loss. This provides hope for efficient treatment of early obesity-associated changes to hepatic complications by simple weight loss intervention without persistent reprograming of the liver transcriptome.
Lytic polysaccharide monooxygenases disrupt the cellulose fibers structure
Authors: Villares Ana , Moreau Céline , Bennati-Granier Chloé , Garajova Sona , Foucat Loïc , Falourd Xavier , Saake Bodo , Berrin Jean-Guy , Cathala Bernard
Published: January 2017

Lytic polysaccharide monooxygenases (LPMOs) are a class of powerful oxidative enzymes that breakdown recalcitrant polysaccharides such as cellulose. Here we investigate the action of LPMOs on cellulose fibers. After enzymatic treatment and dispersion, LPMO-treated fibers show intense fibrillation. Cellulose structure modifications visualized at different scales indicate that LPMO creates nicking points that trigger the disintegration of the cellulose fibrillar structure with rupture of chains and release of elementary nanofibrils. Investigation of LPMO action using solid-state NMR provides direct evidence of modification of accessible and inaccessible surfaces surrounding the crystalline core of the fibrils. The chains breakage likely induces modifications of the cellulose network and weakens fibers cohesion promoting their disruption. Besides the formation of new initiation sites for conventional cellulases, this work provides the first evidence of the direct oxidative action of LPMOs with the mechanical weakening of the cellulose ultrastructure. LPMOs can be viewed as promising biocatalysts for enzymatic modification or degradation of cellulose fibers.
Quantum dynamics study of energy requirement on reactivity for the HBr + OH reaction with a negative-energy barrier
Authors: Wang Yuping , Li Yida , Wang Dunyou
Published: January 2017

A time-dependent, quantum reaction dynamics approach in full dimensional, six degrees of freedom was carried out to study the energy requirement on reactivity for the HBr + OH reaction with an early, negative energy barrier. The calculation shows both the HBr and OH vibrational excitations enhance the reactivity. However, even this reaction has a negative energy barrier, the calculation shows not all forms of energy are equally effective in promoting the reactivity. On the basis of equal amount of total energy, the vibrational energies of both the HBr and OH are more effective in enhancing the reactivity than the translational energy, whereas the rotational excitations of both the HBr and OH hinder the reactivity. The rate constants were also calculated for the temperature range between 5 to 500 K. The quantal rate constants have a better slope agreement with the experimental data than quasi-classical trajectory results.
Biodegradable Magnesium Screws Accelerate Fibrous Tissue Mineralization at the Tendon-Bone Insertion in Anterior Cruciate Ligament Reconstruction Model of Rabbit
Authors: Wang Jiali , Xu Jiankun , Fu Weimin , Cheng Wenxiang , Chan Kaiming , Yung Patrick Shu-hang , Qin Ling
Published: January 2017

The incorporation of tendon graft into bone tunnel is one of the most challenging clinical issues in anterior cruciate ligament (ACL) reconstruction. As a biodegradable metal, Mg has appropriate mechanical strength and osteoinductive effects, thus may be a promising alternative to commercialized products used for graft fixation. Therefore, it was hypothesized that Mg based interference screws would promote tendon graft-bone junction healing when compared to Ti screws. Herein, we compared the effects of Mg and Ti screws on tendon graft healing in rabbits with ACL reconstruction via histological, HR-pQCT and mechanical analysis. The histological results indicated that Mg screws significantly improved the graft healing quality via promoting mineralization at the tendon graft enthesis. Besides, Mg screws significantly promoted bone formation in the peri-screw region at the early healing stage. Importantly, Mg screws exhibited excellent corrosion resistance and the degradation of Mg screws did not induce bone tunnel widening. In tensile testing, there were no significant differences in the load to failure, stress, stiffness and absorption energy between Mg and Ti groups due to the failure mode at the midsubstance. Our findings demonstrate that Mg screws can promote tendon graft healing after ACL reconstruction, implying a potential alternative to Ti screws for clinical applications.
Rules of tissue packing involving different cell types: human muscle organization
Authors: Sánchez-Gutiérrez Daniel , Sáez Aurora , Gómez-Gálvez Pedro , Paradas Carmen , Escudero Luis M.
Published: January 2017

Natural packed tissues are assembled as tessellations of polygonal cells. These include skeletal muscles and epithelial sheets. Skeletal muscles appear as a mosaic composed of two different types of cells: the “slow” and “fast” fibres. Their relative distribution is important for the muscle function but little is known about how the fibre arrangement is established and maintained. In this work we capture the organizational pattern in two different healthy muscles: biceps brachii and quadriceps. Here we show that the biceps brachii muscle presents a particular arrangement, based on the different sizes of slow and fast fibres. By contrast, in the quadriceps muscle an unbiased distribution exists. Our results indicate that the relative size of each cellular type imposes an intrinsic organization into natural tessellations. These findings establish a new framework for the analysis of any packed tissue where two or more cell types exist.
Quantitative proteomic profiling of the extracellular matrix of pancreatic islets during the angiogenic switch and insulinoma progression
Authors: Naba Alexandra , Clauser Karl R. , Mani D. R. , Carr Steven A. , Hynes Richard O.
Published: January 2017

The angiogenic switch, the time at which a tumor becomes vascularized, is a critical step in tumor progression. Indeed, without blood supply, tumors will fail to grow beyond 1 mm3 and are unlikely to disseminate. The extracellular matrix (ECM), a major component of the tumor microenvironment, is known to undergo significant changes during angiogenesis and tumor progression. However the extent of these changes remains unknown. In this study, we used quantitative proteomics to profile the composition of the ECM of pancreatic islets in a mouse model of insulinoma characterized by a precisely timed angiogenic switch. Out of the 120 ECM proteins quantified, 35 were detected in significantly different abundance as pancreatic islets progressed from being hyperplastic to angiogenic to insulinomas. Among these, the core ECM proteins, EFEMP1, fibrillin 1, and periostin were found in higher abundance, and decorin, Dmbt1, hemicentin, and Vwa5 in lower abundance. The angiogenic switch being a common feature of solid tumors, we propose that some of the proteins identified represent potential novel anti-angiogenic targets. In addition, we report the characterization of the ECM composition of normal pancreatic islets and propose that this could be of interest for the design of tissue-engineering strategies for treatment of diabetes.
Alcohol-dose-dependent DNA methylation and expression in the nucleus accumbens identifies coordinated regulation of synaptic genes
Authors: Cervera-Juanes R , Wilhelm L J , Park B , Grant K A , Ferguson B
Published: January 2017

Alterations in DNA methylation have been associated with alcohol exposure and proposed to contribute to continued alcohol use; however, the molecular mechanisms involved remain obscure. We investigated the escalating effects of alcohol use on DNA methylation, gene expression and predicted neural effects in the nucleus accumbens of rhesus macaques that self-administered 4% alcohol for over 12 months. Using an exploratory approach to identify CpG-rich regions, followed by bisulfite sequencing, the methylation levels of 2.7 million CpGs were compared between seven low-binge drinkers and nine heavy–very heavy drinking subjects. We identified 17 significant differential methylation regions (DMRs), including 14 with methylation levels that were correlated with average daily alcohol consumption. The size of the DMRs ranged from 29 to 158 bp (mean=63.7), included 4–19 CpGs per DMR (mean=8.06) and spanned a range of average methylation values from 5 to 34%. Eight of the DMRs mapped to genes implicated in modulating synaptic plasticity. Six of the synaptic genes have not previously been linked to alcohol use. Validation studies of these eight DMRs using bisulfite amplicon sequencing and an expanded set of 30 subjects confirmed the significant alcohol-dose-associated methylation of the DMRs. Expression analysis of three of the DMR-associated genes, LRP5, GPR39 and JAKMIP1, revealed significant correlations between DMR methylation and whole-gene or alternative transcript expression, supporting a functional role in regulating gene expression. Together, these studies suggest that alcohol-associated synaptic remodeling may be regulated and coordinated at the level of DNA methylation.
Nanoparticle delivery of Wnt-1 siRNA enhances photodynamic therapy by inhibiting epithelial–mesenchymal transition for oral cancer
Authors: Ma Chuan , Shi Leilei , Huang Yu , Shen Lingyue , Peng Hao , Zhu Xinyuan , Zhou Guoyu
Published: January 2017

A combination of nanoparticle delivery of Wnt-1 siRNA with photodynamic therapy was realized by inhibiting epithelial–mesenchymal transition.
Warming up for mechanosynthesis – temperature development in ball mills during synthesis
Authors: Kulla Hannes , Wilke Manuel , Fischer Franziska , Röllig Mathias , Maierhofer Christiane , Emmerling Franziska
Published: January 2017

We present a first direct measurement of the temperature during milling combined within situRaman spectroscopy monitoring.
Template-controlled Sonogashira cross-coupling reactions on a Au(111) surface
Authors: Zhang Ran , Lyu Guoqing , Li Deng Yuan , Liu Pei Nian , Lin Nian
Published: January 2017

We employed three metal-coordination structures as templates to control the Sonogashira cross-coupling reactions on a Au(111) surface.
Gd3+–Gd3+distances exceeding 3 nm determined by very high frequency continuous wave electron paramagnetic resonance
Authors: Clayton Jessica A. , Qi Mian , Godt Adelheid , Goldfarb Daniella , Han Songi , Sherwin Mark S.
Published: January 2017

We present a fundamental study of a CW EPR lineshape analysis-based approach to determining Gd–Gd distances at very high frequencies (240 GHz). The approach is demonstrated from cryogenic to biologically-relevant temperatures.
Combining the spin-separated exact two-component relativistic Hamiltonian with the equation-of-motion coupled-cluster method for the treatment of spin–orbit splittings of light and heavy elements
Authors: Cao Zhanli , Li Zhendong , Wang Fan , Liu Wenjian
Published: January 2017

An accurate and efficient treatment of spin–orbit splittings has been achieved by combining the sf-X2C+soc-DKH1 Hamiltonian with the equation-of-motion coupled-cluster method.
Polarization independence of laser-induced nucleation in supersaturated aqueous urea solutions
Authors: Liu Yao , Ward Martin R. , Alexander Andrew J.
Published: January 2017

Imaging reveals no alignment of urea crystal axis with the electric field direction, contrary to current understanding of laser-induced nucleation.
Formation of atmospheric molecular clusters consisting of sulfuric acid and C8H12O6 tricarboxylic acid
Authors: Elm Jonas , Myllys Nanna , Olenius Tinja , Halonen Roope , Kurtén Theo , Vehkamäki Hanna
Published: January 2017

We present the structures and thermochemical properties of (MBTCA)1−3(H2SO4)1−4 atmospheric molecular clusters.
Emerging investigator series: a 14-year depositional ice record of perfluoroalkyl substances in the High Arctic
Authors: MacInnis John J. , French Katherine , Muir Derek C. G. , Spencer Christine , Criscitiello Alison , De Silva Amila O. , Young Cora J.
Published: January 2017

Detection of perfluoroalkyl substances from a remote ice cap indicate the importance of indirect and novel direct atmospheric sources.
Ingestion of soy–whey blended protein augments sports performance and ameliorates exercise-induced fatigue in a rat exercise model
Authors: Ren Guangxu , Yi Suqing , Zhang Hongru , Wang Jing
Published: January 2017

This study sought to determine the effects of soy–whey blended protein supplementation on sports performance and related biochemical parameters after long-term training.
Nucleophilic ring opening of aziridines with amines under catalyst- and solvent-free conditions
Authors: Huang Yi-Yong , Lv Zong-Chao , Yang Xing , Wang Zhao-Lei , Zou Xiao-Xue , Zhao Zhen-Ni , Chen Fei
Published: January 2017

Aza-addition of aziridines under catalyst- and solvent-free conditions was performed to provide access to a wide array of vicinal diamines in up to 95% yields, thus facilitating the scale-up synthesis of the 4-amino-1,2,3,4-tetrahydroisoquinoline derivative.
Inference of cancer mechanisms through computational systems analysis
Authors: Qi Zhen , Voit Eberhard O.
Published: January 2017

The proposed method correctly identified and accurately quantified primary enzymatic alterations in cancer, and these account for over 80% of the metabolic alterations in the investigated carcinoma.
Materials aspects of semiconductor nanocrystals for optoelectronic applications
Authors: Kershaw Stephen V. , Jing Lihong , Huang Xiaodan , Gao Mingyuan , Rogach Andrey L.
Published: January 2017

Semiconductor nanocrystal quantum dots have already emerged as a flat panel display technology but, driven by continuing improvements to the materials and device structures, they are ever closer to reaching commercial viability as infrared photodetectors, efficient LEDs, solar cells and photocatalysts.
Poly(ionic liquid)-based nanogels and their reversible photo-mediated association and dissociation
Authors: Zuo Yong , Yu Junrui , Liu Xiaojun , Cao Peng , Song Pengfei , Wang Rongmin , Xiong Yubing
Published: January 2017

Azo-incorporated PIL nanogels can undergo reversible photo-mediated association and dissociation, and they can also be used as the building blocks to fabricate photo-responsive supramolecular system.
Synthesis of soap-free emulsion with high solid content by differential dripping RAFT polymerization-induced self-assembly
Authors: Wu Juanjuan , Tian Chun , Zhang Lifen , Cheng Zhenping , Zhu Xiulin
Published: January 2017

A soap-free emulsion with high solid content (60%) was successfully prepared by differential dripping RAFT polymerization-induced self-assembly in a semi-batch monomer addition manner.
A facile sol–gel route to prepare functional graphene nanosheets anchored with homogeneous cobalt sulfide nanoparticles as superb sodium-ion anodes
Authors: Chen Tingting , Ma Yifan , Guo Qiubo , Yang Mei , Xia Hui
Published: January 2017

A facile sol–gel route to prepare functional graphene nanosheets/cobalt sulfide hybrid nanocomposites as high-speed-stable sodium-ion anodes.
Elucidation of the reaction mechanisms of isostructural FeSn2and CoSn2negative electrodes for Na-ion batteries
Authors: Vogt Leonie O. , Villevieille Claire
Published: January 2017

FeSn2and CoSn2are tested as suitable negative electrode materials to improve the energy density of Na-ion batteries.
Minimum hyaluronic acid (HA) modified magnetic nanocrystals with less facilitated cancer migration and drug resistance for targeting CD44 abundant cancer cells by MR imaging
Authors: Lee Taeksu , Son Hye Young , Choi Yuna , Shin Youngmin , Oh Seungjae , Kim Jinyoung , Huh Yong-Min , Haam Seungjoo
Published: January 2017

We report minimal amount of hyaluronic acid (HA) conjugated magnetic nanocrystals (mHMs) for targeted imaging of CD44 abundant breast cancer cells with less side effects via MRI.
Highly responsive and broadband photodetectors based on WS2–graphene van der Waals epitaxial heterostructures
Authors: Lan Changyong , Li Chun , Wang Shuai , He Tianying , Zhou Zhifei , Wei Dapeng , Guo Huayang , Yang Hao , Liu Yong
Published: January 2017

A WS2–graphene epitaxial heterostructure based photodetector showed a high responsivity and a broad response spectrum.
Fluorescence patterning with mild illumination in polymer films of photocleavable oxazines
Authors: Thapaliya Ek Raj , Zhang Yang , Raymo Françisco M.
Published: January 2017

The photoinduced cleavage of oxazine heterocycles, connected to macromolecules spin coated on appropriate substrates, occurs efficiently and irreversibly to quench the emission of a fluorescent dopant and allow the imprinting of patterns.
Interlayer expansion of few-layered Mo-doped SnS2 nanosheets grown on carbon cloth with excellent lithium storage performance for lithium ion batteries
Authors: Chen Qiang , Lu Fengqi , Xia Ying , Wang Hai , Kuang Xiaojun
Published: January 2017

Mo-doped SnS2 nanosheets supported on carbon cloth are synthesized. The nanosheets, as additive-free integrated electrodes for LIBs, exhibit a high initial discharge capacity, superior cycling performance and rate capability.
Swift heavy ion irradiation of interstellar dust analogues
Authors: Dartois E. , Chabot M. , Pino T. , Béroff K. , Godard M. , Severin D. , Bender M. , Trautmann C.
Published: January 2017

Context. Interstellar dust grain particles are immersed in vacuum ultraviolet (VUV) and cosmic ray radiation environments influencing their physicochemical composition. Owing to the energetic ionizing interactions, carbonaceous dust particles release fragments that have direct impact on the gas phase chemistry.

Aims. The exposure of carbonaceous dust analogues to cosmic rays is simulated in the laboratory by irradiating films of hydrogenated amorphous carbon interstellar analogues with energetic ions. New species formed and released into the gas phase are explored.

Methods. Thin carbonaceous interstellar dust analogues were irradiated with gold (950 MeV), xenon (630 MeV), and carbon (43 MeV) ions at the GSI UNILAC accelerator. The evolution of the dust analogues is monitored in situ as a function of fluence at 40, 100, and 300 K. Effects on the solid phase are studied by means of infrared spectroscopy complemented by simultaneously recording mass spectrometry of species released into the gas phase.

Results. Specific species produced and released under the ion beam are analyzed. Cross sections derived from ion-solid interaction processes are implemented in an astrophysical context.
Retrospective Matched-Pair Cohort Study on Effect of Bisegmental Fenestration versus Hemilaminectomy for Bisegmental Spinal Canal Stenosis at L3–L4 and L4–L5
Authors: Weber Friedrich , Schüppel Julia
Published: January 2017

Background The main symptoms of degenerative lumbar spinal canal stenosis are progressive back pain, spinal claudication, and, occasionally, sensory and motor deficits. Impairments particularly occur during walking, standing, and sitting. Thus social and vocational activities are increasingly restricted, causing considerable suffering for patients. Surgical therapies are superior to conservative ones. This article studies the outcome of 2-level fenestration versus hemilaminectomy for bisegmental spinal stenosis decompression.

Methods This retrospective matched-pair cohort study included a total of 144 patients who underwent surgery for bisegmental spinal stenosis at the levels L3-4 and L4-5 between 2008 and 2012. There were 72 matching pairs that corresponded in sex, year of birth, and width of the stenosed segments. The patients' impairments were reported before, immediately after, and 6 and 12 months after surgery using the Oswestry Disability Questionnaire (ODQ-D) and the EuroQol-5D (EQ-5D). The data were evaluated statistically.

Results The comparison of both surgical procedures regarding walking ability (walking a distance with and without a walking aid) revealed a significant difference. Patients who underwent hemilaminectomy had better postoperative results. The individual criteria of the ODQ-D and EQ-5D revealed no significant differences between 2-level fenestration and hemilaminectomy; however, there is always significant postoperative improvement in comparison with preoperative status. Age, sex, body mass index, comorbidities, smoking, and alcohol consumption had no influence on the surgical results. The reoperation rate was between 13% and 15% for both surgical techniques, not being significantly different.

Conclusion Fenestration and hemilaminectomy are equivalent therapies for bisegmental lumbar spinal canal stenosis. Regarding walking, the study revealed better results for hemilaminectomy than for fenestration in this cohort of patients. Pain intensity, personal care, lifting and carrying of objects, sitting, social life, and travel all improved significantly postoperatively as compared with preoperatively. In both groups, health status as the decisive predictor improved considerably after surgery. We could show that both surgical methods result in significant postoperative improvement of all the individual criteria of the ODQ-D and the EQ-5D.