bluuebunny/crossref_metadata_2025 huggingface dataset:
Roux-Y Gastric Bypass and Sleeve Gastrectomy directly change gut microbiota composition independent of surgery type
Authors: Paganelli Fernanda L. , Luyer Misha , Hazelbag C. Marijn , Uh Hae-Won , Rogers Malbert R. C. , Adriaans Danielle , Berbers Roos-Marijn , Hendrickx Antoni P. A. , Viveen Marco C. , Groot James A. , Bonten Marc J. M. , Fluit Ad C. , Willems Rob J. L. , Leavis Helen L.
Published: July 2019

Bariatric surgery in morbid obesity, either through sleeve gastrectomy (SG) or Roux-Y gastric bypass (RYGB), leads to sustainable weight loss, improvement of metabolic disorders and changes in intestinal microbiota. Yet, the relationship between changes in gut microbiota, weight loss and surgical procedure remains incompletely understood. We determined temporal changes in microbiota composition in 45 obese patients undergoing crash diet followed by SG (n = 22) or RYGB (n = 23). Intestinal microbiota composition was determined before intervention (baseline, S1), 2 weeks after crash diet (S2), and 1 week (S3), 3 months (S4) and 6 months (S5) after surgery. Relative to S1, the microbial diversity index declined at S2 and S3 (p < 0.05), and gradually returned to baseline levels at S5. Rikenellaceae relative abundance increased and Ruminococcaceae and Streptococcaceae abundance decreased at S2 (p < 0.05). At S3, Bifidobacteriaceae abundance decreased, whereas those of Streptococcaceae and Enterobacteriaceae increased (p < 0.05). Increased weight loss between S3-S5 was not associated with major changes in microbiota composition. No significant differences appeared between both surgical procedures. In conclusion, undergoing a crash diet and bariatric surgery were associated with an immediate but temporary decline in microbial diversity, with immediate and permanent changes in microbiota composition, independent of surgery type.
Preparation of Monoacylglycerol Derivatives from Indonesian Edible Oil and Their Antimicrobial Assay against Staphylococcus aureus and Escherichia coli
Authors: Jumina Jumina , Lavendi Wenggi , Singgih Tubagus , Triono Sugeng , Steven Kurniawan Yehezkiel , Koketsu Mamoru
Published: July 2019

In the present work, linoleic acid and oleic acid were isolated from Indonesian corn oil and palm oil and they were used to prepare monoacylglycerol derivatives as the antibacterial agent. Indonesian corn oil contains 57.74% linoleic acid, 19.88% palmitic acid, 11.84% oleic acid and 3.02% stearic acid. While Indonesian palm oil contains 44.72% oleic acid, 39.28% palmitic acid, 4.56% stearic acid and 1.54% myristic acid. The oleic acid was purified by using Urea Inclusion Complex (UIC) method and its purity was significantly increased from 44.72% to 94.71%. Meanwhile, with the UIC method, the purity of ethyl linoleate was increased from 57.74% to 72.14%. 1-Monolinolein and 2-monoolein compounds were synthesized via two-step process from the isolated linoleic acid and oleic acid, respectively. The preliminary antibacterial assay shows that the 1-monolinolein did not give any antibacterial activity against Staphylococcus aureus and Escherichia coli, while 2-monoolein showed weak antibacterial activity against Staphylococcus aureus.
Establishment of a Murine Pro-acinar Cell Line to Characterize Roles for FGF2 and α3β1 Integrins in Regulating Pro-acinar Characteristics
Authors: Thiemann Renée F. , Nelson Deirdre A. , Michael DiPersio C. , Larsen Melinda , LaFlamme Susan E.
Published: July 2019

Radiation therapy for head and neck cancers results in permanent damage to the saliva producing acinar compartment of the salivary gland. To date, a pure pro-acinar cell line to study underlying mechanisms of acinar cell differentiation in culture has not been described. Here, we report the establishment of a pro-acinar (mSG-PAC1) and ductal (mSG-DUC1) cell line, from the murine submandibular salivary gland (SMG), which recapitulate developmental milestones in differentiation. mSG-DUC1 cells express the ductal markers, keratin-7 and keratin-19, and form lumenized spheroids. mSG-PAC1 cells express the pro-acinar markers SOX10 and aquaporin-5. Using the mSG-PAC1 cell line, we demonstrate that FGF2 regulates specific steps during acinar cell maturation. FGF2 up-regulates aquaporin-5 and the expression of the α3 and α6 subunits of the α3β1 and α6β1 integrins that are known to promote SMG morphogenesis and differentiation. mSG-DUC1 and mSG-PAC1 cells were derived from genetically modified mice, homozygous for floxed alleles of the integrin α3 subunit. Similar to SMGs from α3-null mice, deletion of α3 alleles in mSG-PAC1 cells results in the up-regulation of E-cadherin and the down-regulation of CDC42. Our data indicate that mSG-DUC1 and mSG-PAC1 cells will serve as important tools to gain mechanistic insight into salivary gland morphogenesis and differentiation.
Predictability of US West Coast Ocean Temperatures is not solely due to ENSO
Authors: Capotondi Antonietta , Sardeshmukh Prashant D. , Di Lorenzo Emanuele , Subramanian Aneesh C. , Miller Arthur J.
Published: July 2019

The causes of the extreme and persistent warming in the Northeast Pacific from the winter of 2013/14 to that of 2014/15 are still not fully understood. While global warming may have contributed, natural influences may also have played a role. El Niño events are often implicated in anomalously warm conditions along the US West Coast (USWC). However, the tropical Pacific sea surface temperature (SST) anomalies were generally weak during 2014, calling into question their role in the USWC warming. In this study, we identify tropical Pacific “sensitivity patterns” that optimally force USWC warming at a later time. We find that such sensitivity patterns do not coincide with the mature SST anomaly patterns usually associated with ENSO, but instead include elements associated with ENSO SST precursors and SST anomalies in the central/western equatorial Pacific. El Niño events that produce large USWC warming, irrespective of their magnitude, do project on the sensitivity pattern and are characterized by a distinct evolution of the North Pacific atmospheric and oceanic fields. However, even weak tropical SST anomalies in the right location, and not necessarily associated with ENSO, can significantly influence USWC conditions and enhance their predictability.
Protein phosphatases regulate growth, development, cellulases and secondary metabolism in Trichoderma reesei
Authors: Rodriguez-Iglesias Aroa , Schmoll Monika
Published: July 2019

Trichoderma reeseirepresents one of the most prolific producers of plant cell wall degrading enzymes. Recent research showed broad regulation by phosphorylation inT. reesei, including important transcription factors involved in cellulase regulation. To evaluate factors crucial for changes in these phosphorylation events, we studied non-essential protein phosphatases (PPs) ofT. reesei. Viable deletion strains were tested for growth on different carbon sources, osmotic and oxidative stress response, asexual and sexual development, cellulase and protease production as well as secondary metabolism. Six PPs were found to be positive or negative regulators for cellulase production. A correlation of the effects of PPs on protease activities and cellulase activities was not detected. Hierarchical clustering of regulation patterns and phenotypes of deletion indicated functional specialization within PP classes and common as well as variable effects. Our results confirmed the central role of catalytic and regulatory subunits of PP2A which regulates several aspects of cell growth and metabolism. Moreover we show that the additional homologue of PPH5 inTrichodermaspp., PPH5-2 assumes distinct functions in metabolism, development and stress response, different from PPH5. The influence of PPs on both cellulase gene expression and secondary metabolite production support an interrelationship in the underlying regulation mechanisms.
Atlantic origin of asynchronous European interdecadal hydroclimate variability
Authors: Zanchettin Davide , Toniazzo Thomas , Taricco Carla , Rubinetti Sara , Rubino Angelo , Tartaglione Nazario
Published: July 2019

Discharge time series of major large-catchment European rivers are known to display significant decadal and interdecadal fluctuations. However, the hydroclimate variability causing such fluctuations remains poorly understood, particularly due to a lack of a spatio-temporal integrated assessment. Here, we demonstrate for the first time that European hydroclimate variability is dominated by a meridional delayed oscillation characterized by a lag of approximately 5 years in interdecadal discharge fluctuations of continental (northern) European rivers with respect to those of Euro-Mediterranean (southern) rivers. We demonstrate a connection of this coherent signal with the large-scale atmospheric circulation over the North Atlantic, and suggest a hitherto unexplored multiannual atmosphere-ocean mechanism in the subpolar North Atlantic at its root.
High prevalence of the MLH1 V384D germline mutation in patients with HER2-positive luminal B breast cancer
Authors: Lee Seung Eun , Lee Hye Seung , Kim Kyoung-Yeon , Park Jung-Hoon , Roh Hanseong , Park Ha Young , Kim Wan-Seop
Published: July 2019

HER2-positive luminal B breast cancer (BC), a subset of the luminal B subtype, is ER-positive and HER2-positive BC which is approximately 10% of all BC. However, HER2-positive luminal B BC has received less attention and is less represented in previous molecular analyses than other subtypes. Hence, it is important to elucidate the molecular biology of HER2-positive luminal B BC to stratify patients in a way that allows them to receive their respective optimal treatment. We performed molecular profiling using targeted next-generation sequencing on 94 HER2-positive luminal B BC to identify its molecular characteristics. A total of 134 somatic nonsynonymous mutations, including 131 nonsynonymous single nucleotide variants and three coding insertions/deletions were identified in 30 genes of 75 samples. PIK3CA was most frequently mutated (38/94, 40.4%), followed by TP53 (31/94, 33.0%), and others were detected at lower frequencies. Recurrent germline mutations of MLH1 V384D were found in 13.8% (13/94), with a significantly high TP53 mutations rate. The frequency of MLH1 V384D germline mutation in individuals with HER2-positive luminal B BC was significantly higher than that observed in the controls. All 13 cases were classified as microsatellite stable tumors. Tumor mutation burdens (TMB) were not significantly different between MLH1 V384D carrier and wild type. The concordant results of microsatellite instability (MSI) and TMB suggest that the haploinsufficiency of MLH1 plays a role as a tumor predisposition factor rather than a direct oncogenic driver. Our study identified, for the first time, that MLH1 V384D germline variant is frequently detected in HER2-positive luminal B BC. MLH1 V384D germline variant may not only contribute to gastrointestinal cancer predisposition but may also contribute to BC in East Asians.
Migration rather than proliferation transcriptomic signatures are strongly associated with breast cancer patient survival
Authors: Nair Nishanth Ulhas , Das Avinash , Rogkoti Vasiliki-Maria , Fokkelman Michiel , Marcotte Richard , de Jong Chiaro G. , Koedoot Esmee , Lee Joo Sang , Meilijson Isaac , Hannenhalli Sridhar , Neel Benjamin G. , de Water Bob van , Le Dévédec Sylvia E. , Ruppin Eytan
Published: July 2019

The efficacy of prospective cancer treatments is routinely estimated by in vitro cell-line proliferation screens. However, it is unclear whether tumor aggressiveness and patient survival are influenced more by the proliferative or the migratory properties of cancer cells. To address this question, we experimentally measured proliferation and migration phenotypes across more than 40 breast cancer cell-lines. Based on the latter, we built and validated individual predictors of breast cancer proliferation and migration levels from the cells’ transcriptomics. We then apply these predictors to estimate the proliferation and migration levels of more than 1000 TCGA breast cancer tumors. Reassuringly, both estimates increase with tumor’s aggressiveness, as qualified by its stage, grade, and subtype. However, predicted tumor migration levels are significantly more strongly associated with patient survival than the proliferation levels. We confirmed these findings by conducting siRNA knock-down experiments on the highly migratory MDA-MB-231 cell lines and deriving gene knock-down based proliferation and migration signatures. We show that cytoskeletal drugs might be more beneficial in patients with high predicted migration levels. Taken together, these results testify to the importance of migration levels in determining patient survival.
Glial gene networks associated with alcohol dependence
Authors: Erickson Emma K. , Blednov Yuri A. , Harris R. Adron , Mayfield R. Dayne
Published: July 2019

Chronic alcohol abuse alters the molecular structure and function of brain cells. Recent work suggests adaptations made by glial cells, such as astrocytes and microglia, regulate physiological and behavioral changes associated with addiction. Defining how alcohol dependence alters the transcriptome of different cell types is critical for developing the mechanistic hypotheses necessary for a nuanced understanding of cellular signaling in the alcohol-dependent brain. We performed RNA-sequencing on total homogenate and glial cell populations isolated from mouse prefrontal cortex (PFC) following chronic intermittent ethanol vapor exposure (CIE). Compared with total homogenate, we observed unique and robust gene expression changes in astrocytes and microglia in response to CIE. Gene co-expression network analysis revealed biological pathways and hub genes associated with CIE in astrocytes and microglia that may regulate alcohol-dependent phenotypes. Astrocyte identity and synaptic calcium signaling genes were enriched in alcohol-associated astrocyte networks, while TGF-β signaling and inflammatory response genes were disrupted by CIE treatment in microglia gene networks. Genes related to innate immune signaling, specifically interferon pathways, were consistently up-regulated across CIE-exposed astrocytes, microglia, and total homogenate PFC tissue. This study illuminates the cell-specific effects of chronic alcohol exposure and provides novel molecular targets for studying alcohol dependence.
Similarity index for intuitive assessment of three-dimensional facial asymmetry
Authors: Kwon Sun Mi , Hwang Jae Joon , Jung Yun-Hoa , Cho Bong-Hae , Lee Kee-Joon , Hwang Chung-Ju , Choi Sung-Hwan
Published: July 2019

Evaluation of facial asymmetry generally involves landmark-based analyses that cannot intuitively assess differences in three-dimensional (3D) stereoscopic structures between deviation and non-deviation sides. This study tested a newly developed similarity index that uses a mirroring technique to intuitively evaluate 3D mandibular asymmetry, and characterised the resulting lower facial soft tissue asymmetry. The similarity index was used to evaluate asymmetry before and after surgery in 46 adult patients (27 men, 19 women; age, 22 ± 4.8 years) with skeletal Class III malocclusion and facial asymmetry who underwent conventional bimaxillary orthognathic surgery. Relative to the midsagittal plane used as the reference plane, the non-overlapping volume of the mandible significantly decreased, and the similarity index significantly increased after surgery. Similarity indexes of the mandible and lower facial soft tissue were strongly negatively correlated with non-overlapping volumes of each measurement. Differences in bilateral hemi-mandibular and hemi-lower facial soft tissue surface and volume measurements before surgery were significantly negatively correlated with similarity indexes of the mandible before and after surgery. This newly developed similarity index and non-overlapping volume using a mirroring technique can easily and intuitively evaluate overall 3D morphological discrepancies, especially 3D mandibular asymmetry, before and after surgery in skeletal Class III patients with facial asymmetry.
Night-shift work, circadian and melatonin pathway related genes and their interaction on breast cancer risk: evidence from a case-control study in Korean women
Authors: Pham Thu-Thi , Lee Eun-Sook , Kong Sun-Young , Kim Jeongseon , Kim Sun-Young , Joo Jungnam , Yoon Kyong-Ah , Park Boyoung
Published: July 2019

Our purpose is to investigate the impact of circadian and melatonin pathway genes as well as their interactions with night-shift work (NSW) on breast cancer risk in Korean women. Information about NSW and other covariates was collected using a structured questionnaire and twenty-two polymorphisms in 11 genes were analyzed in a hospital-based case-control study with 941 cases of breast cancer and 959 controls. In analysis of the main effects of each single nucleotide polymorphisms(SNPs), variants in CLOCK rs11133373 was associated with breast cancer risk even after false discovery rate (FDR) correction (Odd Ratios (OR) = 1.38 (95% Confident Interval (CI) 1.14–1.69) in CG and CC compared to GG genotype. Analysis of MTNR1A rs2119882 demonstrated a decreased risk of breast cancer in CC compared to TT (p-FDR = 0.043). A correlation between NSW and breast cancer interaction was found in two loci. NSW increased risk of breast cancer in women who carried the heterozygote genotype of CRY2 rs2292912 (OR = 1.98, 95% CI = 1.14–3.44) or carried at least one minor allele of RORA rs1482057 (OR = 2.20, 95% CI = 1.10–4.37). Our study results support a putative role for several loci of circadian genes and genes of melatonin biosynthesis and their interaction, and the gene interactions with NSW in the development of breast cancer.
Catalytically Competent Non-transforming H-RASG12P Mutant Provides Insight into Molecular Switch Function and GAP-independent GTPase Activity of RAS
Authors: Ilter Metehan , Sensoy Ozge
Published: July 2019

RAS mutants have been extensively studied as they are associated with development of cancer; however, H-RASG12P mutant has remained untouched since it does not lead to transformation in the cell. To the best of our knowledge, this is the first study where structural/dynamical properties of H-RASG12P have been investigated -in comparison to H-RASWT, H-RASG12D, RAF-RBD-bound and GAP-bound H-RASWT- using molecular dynamics simulations (total of 9 μs). We observed remarkable differences in dynamics of Y32. Specifically, it is located far from the nucleotide binding pocket in the catalytically-active GAP-bound H-RASWT, whereas it makes close interaction with the nucleotide in signaling-active systems (H-RASG12D, KRAS4BG12D, RAF-RBD-bound H-RASWT) and H-RASWT. The accessibility of Y32 in wild type protein is achieved upon GAP binding. Interestingly; however, it is intrinsically accessible in H-RASG12P. Considering the fact that incomplete opening of Y32 is associated with cancer, we propose that Y32 can be targeted by means of small therapeutics that can displace it from the nucleotide binding site, thus introducing intrinsic GTPase activity to RAS mutants, which cannot bind to GAP. Therefore, mimicking properties of H-RASG12P in RAS-centered drug discovery studies has the potential of improving success rates since it acts as a molecular switch per se.
In vivo direct reprogramming of glial linage to mature neurons after cerebral ischemia
Authors: Yamashita Toru , Shang Jingwei , Nakano Yumiko , Morihara Ryuta , Sato Kota , Takemoto Mami , Hishikawa Nozomi , Ohta Yasuyuki , Abe Koji
Published: July 2019

The therapeutic effect of in vivo direct reprogramming on ischemic stroke has not been evaluated. In the present study, a retroviral solution (1.5–2.0 × 107 /ul) of mock pMX-GFP (n = 13) or pMX-Ascl1/Sox2/NeuroD1 (ASN) (n = 14) was directly injected into the ipsilateral striatum and cortex 3 days after 30 min of transient cerebral ischemia. The reprogrammed cells first expressed neuronal progenitor marker Dcx 7 and 21 days after viral injection, then expressed mature neuronal marker NeuN. This was accompanied by morphological changes, including long processes and synapse-like structures, 49 days after viral injection. Meanwhile, therapeutic improvement was not detected both in clinical scores or infarct volume. The present study provides a future novel self-repair strategy for ischemic stroke with beneficial modifications of the inducer-suppressor balance.
Population variability of rhesus macaque (Macaca mulatta) NAT1 gene for arylamine N-acetyltransferase 1: Functional effects and comparison with human
Authors: Boukouvala Sotiria , Chasapopoulou Zoi , Giannouri Despina , Kontomina Evanthia , Marinakis Nikolaos , Rizou Sophia V. , Stefani Ioanna , Tsirka Theodora , Veyssière Charlotte , Zaliou Sofia , Sabbagh Audrey , Crouau-Roy Brigitte , Fakis Giannoulis
Published: July 2019

Human NAT1 gene for N-acetyltransferase 1 modulates xenobiotic metabolism of arylamine drugs and mutagens. Beyond pharmacogenetics, NAT1 is also relevant to breast cancer. The population history of human NAT1 suggests evolution through purifying selection, but it is unclear whether this pattern is evident in other primate lineages where population studies are scarce. We report NAT1 polymorphism in 25 rhesus macaques (Macaca mulatta) and describe the haplotypic and functional characteristics of 12 variants. Seven non-synonymous single nucleotide variations (SNVs) were identified and experimentally demonstrated to compromise enzyme function, mainly through destabilization of NAT1 protein and consequent activity loss. One non-synonymous SNV (c.560G > A, p.Arg187Gln) has also been characterized for human NAT1 with similar effects. Population haplotypic and functional variability of rhesus NAT1 was considerably higher than previously reported for its human orthologue, suggesting different environmental pressures in the two lineages. Known functional elements downstream of human NAT1 were also differentiated in rhesus macaque and other primates. Xenobiotic metabolizing enzymes play roles beyond mere protection from exogenous chemicals. Therefore, any link to disease, particularly carcinogenesis, may be via modulation of xenobiotic mutagenicity or more subtle interference with cell physiology. Comparative analyses add the evolutionary dimension to such investigations, assessing functional conservation/diversification among primates.
Strategies and limitations in app usage and human mobility
Authors: De Nadai Marco , Cardoso Angelo , Lima Antonio , Lepri Bruno , Oliver Nuria
Published: July 2019

Cognition has been found to constrain several aspects of human behaviour, such as the number of friends and the number of favourite places a person keeps stable over time. This limitation has been empirically defined in the physical and social spaces. But do people exhibit similar constraints in the digital space? We address this question through the analysis of pseudonymised mobility and mobile application (app) usage data of 400,000 individuals in a European country for six months. Despite the enormous heterogeneity of apps usage, we find that individuals exhibit a conserved capacity that limits the number of applications they regularly use. Moreover, we find that this capacity steadily decreases with age, as does the capacity in the physical space but with more complex dynamics. Even though people might have the same capacity, applications get added and removed over time. In this respect, we identify two profiles of individuals: app keepers and explorers, which differ in their stable (keepers) vs exploratory (explorers) behaviour regarding their use of mobile applications. Finally, we show that the capacity of applications predicts mobility capacity and vice-versa. By contrast, the behaviour of keepers and explorers may considerably vary across the two domains. Our empirical findings provide an intriguing picture linking human behaviour in the physical and digital worlds which bridges research studies from Computer Science, Social Physics and Computational Social Sciences.
New Absorbable Microvascular Anastomotic Devices Representing a Modified Sleeve Technique: Evaluation of Two Types of Source Material and Design
Authors: Jeong Woonhyeok , Kim Kyuhee , Son Daegu , Kim Yunkun
Published: July 2019

The purpose of this study was to create a new absorbable vascular anastomotic coupler and evaluate the patency and degradation degree. Vascular anastomosis was performed in the jugular vein in 31 New Zealand white female rabbits. The coupler consisted of an inner and outer ring. One side of the jugular vein was passed through and overlapped the inner ring. The opposite side of the jugular vein overlapped the everted jugular vein on the inner ring. Then, the outer ring engaged with the inner ring and completed the anastomosis. The outer rings were also constructed with two shapes including an O-type that had no slit and a C-type with a slit on the outer ring of the O-type coupler to allows expandability of the diameter. A Phase I experiment was performed to evaluate the degradability of the source materials, including the poly (lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) couplers. A Phase II experiment was performed to evaluate the patency and anastomosis time of the O-type PLGA and PCL couplers. A Phase III experiment was performed to evaluate the patency and anastomosis time of suture anastomosis (control) and the C-type PLGA coupler. The patency was determined by ultrasonography and open exploration. Histological analysis was performed to determine the degradability of the couplers. In Phase I, the PLGA couplers were completely degraded with good vascular wall remodeling at 8 months, while the PCL couplers demonstrated incomplete degradation. In Phases II and III, the anastomosis time was significantly shorter in the coupler groups than that in the control group. All of the coupler groups demonstrated complete patency of the anastomoses on ultrasonography. In Phase III, the C-type PLGA coupler also demonstrated patency and complete degradation at 8 months. PLGA is a suitable source material for absorbable couplers due to its fast degradability. We devised the O-shaped outer ring for the C-shaped outer ring to increase flexibility, which also demonstrated complete patency during the experimental period. Our absorbable microvascular anastomosis devices could provide rapid and reliable microvascular anastomosis without anastomotic failure.
Magnetic Order with Fractionalized Excitations in Pyrochlore Magnets with Strong Spin-Orbit Coupling
Authors: Chern Li Ern , Kim Yong Baek
Published: July 2019

A recent inelastic neutron scattering experiment on the pyrochlore magnet Yb2Ti2O7 uncovers an unusual scattering continuum in the spin excitation spectrum despite the splayed ferromagnetic order in the ground state. While there exist well defined spin wave excitations at high magnetic fields, the one magnon modes and the two magnon continuum start to strongly overlap upon decreasing the field, and eventually they become the scattering continuum at zero field. Motivated by these observations, we investigate the possible emergence of a magnetically ordered ground state with fractionalized excitations in the spin model with the exchange parameters determined from two previous experiments. Using the fermionic parton mean field theory, we show that the magnetically ordered state with fractionalized excitations can arise as a stable mean field ground state in the presence of sufficiently strong quantum fluctuations. The spin excitation spectrum in such a ground state is computed and shown to have the scattering continuum. Upon increasing the field, the fractionalized magnetically ordered state is suppressed, and is eventually replaced by the conventional magnetically ordered phase at high fields, which is consistent with the experimental data. We discuss further implications of these results to the experiments and possible improvements on the theoretical analysis.
Characterization of genes in guar gum biosynthesis based on quantitative RNA-sequencing in guar bean (Cyamopsis tetragonoloba)
Authors: Hu Haiyan , Wang Haijie , Zhang Yaoyuan , Kan Baolin , Ding Yuanhao , Huang Jiaquan
Published: July 2019

Guar gum is an important raw material in the food, textile and oil industries, but the biosynthesis of guar gum remains unclear. To illuminate the genes involved in guar gum biosynthesis, guar beans from 30 and 40 days after flowering (DAF) were used for RNA sequencing in this study. A total of 2,535 and 2,724 preferentially expressed genes were found in 30 and 40 DAF endosperm, and 3,720 and 2,530 preferentially expressed genes were found in 30 and 40 DAF embryos, respectively. Of these, mannan synthase genes, α-galactosyltransferase genes and cellulose synthase genes were preferentially expressed in the endosperm from 30 and 40 DAF. The high expression level of these glycometabolism genes in endosperm is consistent with the expectation that the main component of guar gum is galactomannan. We believe that genes related to guar gum biosynthesis found in this study will be useful for both new variety development via genetic engineering and synthetic biology research on guar gum biosynthesis in the future.
From curved spacetime to spacetime-dependent local unitaries over the honeycomb and triangular Quantum Walks
Authors: Arrighi Pablo , Di Molfetta Giuseppe , Marquez-Martin Ivan , Perez Armando
Published: July 2019

A discrete-time Quantum Walk (QW) is an operator driving the evolution of a single particle on the lattice, through local unitaries. In a previous paper, we showed that QWs over the honeycomb and triangular lattices can be used to simulate the Dirac equation. We apply a spacetime coordinate transformation upon the lattice of this QW, and show that it is equivalent to introducing spacetime-dependent local unitaries —whilst keeping the lattice fixed. By exploiting this duality between changes in geometry, and changes in local unitaries, we show that the spacetime-dependent QW simulates the Dirac equation in (2 + 1)–dimensional curved spacetime. Interestingly, the duality crucially relies on the non linear-independence of the three preferred directions of the honeycomb and triangular lattices: The same construction would fail for the square lattice. At the practical level, this result opens the possibility to simulate field theories on curved manifolds, via the quantum walk on different kinds of lattices.
Bidirectional optogenetic modulation of prefrontal-hippocampal connectivity in pain-related working memory deficits
Authors: Cardoso-Cruz Helder , Paiva Pedro , Monteiro Clara , Galhardo Vasco
Published: July 2019

Dysfunction of the prefrontal-hippocampal circuit has been identified as a leading cause to pain-related working-memory (WM) deficits. However, the underlying mechanisms remain poorly determined. To address this issue, we implanted multichannel arrays of electrodes in the prelimbic cortex (PL-mPFC), and in the dorsal hippocampal CA1 field (dCA1) to record the neural activity during the performance of a delayed non-match to sample (DNMS) task. The prefrontal-hippocampal connectivity was selectively modulated by bidirectional optogenetic inhibition or stimulation of local PL-mPFC glutamatergic calcium/calmodulin-dependent protein kinase-II alpha (CaMKIIα) expressing neurons during the DNMS task delay-period. The within-subject behavioral performance was assessed using a persistent neuropathic pain model – spared nerve injury (SNI). Our results showed that the induction of the neuropathic pain condition affects the interplay between PL-mPFC and dCA1 regions in a frequency-dependent manner, and that occurs particularly across theta oscillations while rats performed the task. In SNI-treated rats, this disruption was reversed by the selective optogenetic inhibition of PL-mPFC CaMKIIα-expressing neurons during the last portion of the delay-period, but without any significant effect on pain responses. Finally, we found that prefrontal-hippocampal theta connectivity is strictly associated with higher performance levels. Together, our findings suggest that PL-mPFC CaMKIIα-expressing neurons could be modulated by painful conditions and their activity may be critical for prefrontal-hippocampal connectivity during WM processing.
High Resolution Magic Angle Spinning (HRMAS) Pulse Field Gradient (PFG) NMR Diffusometry Studies of Swollen Polymers
Authors: Alam Todd M.
Published: July 2019

In this chapter, the combination of high resolution magic angle spinning (HRMAS) NMR spectroscopy and pulse field gradient (PFG) NMR diffusometry techniques to study solvent transport in swollen polymers is presented. The MAS suppression of magnetic susceptibility differences that exist for liquids absorbed in heterogenous polymer materials is shown to provide significant improvements in the NMR spectral resolution, thereby allowing the use of PFG NMR diffusion experiments to probe multiple chemical environments simultaneously. Recent examples of using 1H HRMAS PFG NMR experiments to measure solvent diffusion in 3D-printed siloxane polymer composites are detailed, along with an example of characterizing diffusion in methanol fuel cell anion exchange polymer membranes. These results demonstrate the power of HRMAS PFG NMR diffusometry to obtain information for complex chemical mixtures absorbed in polymers.
Structure and Molecular Dynamics of Semicrystalline Polymers as Studied by Solid-state NMR
Authors: Zheng Zhaoxi , Ma Jiayang , Wang Kun , Jin Fan , Miyoshi Toshikazu
Published: July 2019

Chain-level structure of semicrystalline polymers in melt- and solution-grown crystals has been debated over the past several decades. Recently, 13C–13C double quantum (DQ) NMR spectroscopy and spin-dynamics simulation have been applied to trace chain trajectory and packing structure of 13C labeled polymers in melt- and solution-grown crystals. We highlight recent NMR studies for (i) packing structure, (ii) chain trajectory, (iii) conformation of the folded chains, (iv) nucleation mechanisms in the early stage of crystallization, and (v) deformation mechanism at the molecular scale of semicrystalline polymers.
Molecular Chain Packing and Conformation in π-Conjugated Polymers from Solid-state NMR
Authors: Selter Philipp , Hansen Michael Ryan
Published: July 2019

Polymers with extended π-conjugation are currently of broad scientific interest due to their promising applications as the active semiconducting material in flexible organic electronic devices. The main advantage of using π-conjugated polymers is that this enables the fabrication via solution processing. However, this yields materials that are semicrystalline, potentially lacking any long-range order, and prevents direct access to details about the molecular organization from a conventional approach. In this chapter, we first provide the reader with a brief introduction to the area of semiconducting π-conjugated polymers and the challenges associated with characterizing their structure at the molecular level. This is followed by a selected overview of 1D and 2D solid-state NMR techniques that are capable of elucidating the molecular chain packing and conformation for semicrystalline π-conjugated polymers. Finally, three examples are given highlighting how the selected NMR techniques can be used to gain molecular insights into this kind of material.
Solid-state NMR and Membrane Proteins: Key Interactions in Biomacromolecules
Authors: Shigeta Arisu , Kawamura Izuru
Published: July 2019

Membrane proteins play a crucial role in maintaining the homeostasis of living cells. The characterization of key membrane protein interactions, such as specific hydrogen bonds and electrostatic contacts in the reaction centre of membrane proteins, is a fairly straightforward approach for understanding their function at a molecular level. Solid-state nuclear magnetic resonance (NMR) spectroscopy is convenient for the structural and biophysical analysis of membrane proteins embedded in lipid bilayers. In this chapter, we introduce several recent NMR approaches for ingenious detection of key interactions on membrane proteins. Monitoring of the alterations in isotropic chemical shifts can find local structural change of sodium ion pump rhodopsin depending on pH, alkali metal ions, site-specific mutation, etc. Magic angle spinning (MAS) NMR experiments using recoupled 13C–15N heteronuclear and 13C–13C homonuclear dipolar interactions are applied to determine drug-binding site in M2 protein. To detect an initial proton transfer pathway in the light-driven proton pump protein, 1H–15N correlations assisted by dynamic nuclear polarization (DNP) with photo-irradiation can be observed for each photo-intermediate as a snapshot.
Structural Investigations of Polymer Materials by Dynamic Nuclear Polarisation Solid-state NMR
Authors: Mollica Giulia , Ziarelli Fabio , Thureau Pierre , Viel Stéphane
Published: July 2019

Solid-state nuclear magnetic resonance (SSNMR) has established itself as an essential structural elucidation technique in polymer science because it can non-destructively provide unique molecular-level information with atomic resolution on complex macromolecular materials, especially when combined with complementary techniques such as scattering and computer simulation. The Achilles’ heel of NMR, however, is its low sensitivity due to the weak nuclear spin polarisation at thermal equilibrium, even at very high magnetic fields. One intriguing way to enhance NMR sensitivity is dynamic nuclear polarisation (DNP), which relies on the microwave-driven transfer of thermal electron spin polarisation to nuclei. DNP is attracting scientific attention owing to the availability of both high-power/high-frequency microwave sources and efficient DNP polarising agents (i.e., paramagnetic species used for doping diamagnetic samples to provide the source of electron polarisation for DNP). At moderately high magnetic fields (∼10 T), large DNP signal enhancements can now be readily obtained, which has led to unprecedented SSNMR applications. In this review, we describe the requirements for high-field DNP SSNMR and provide examples of its use for the structural analysis of organic polymer materials, so as to highlight its advantages and (current) limitations for the field.
Epistemological problems underlying pre-service chemistry teachers’ aims to use practical work in school science
Authors: Yeşiloğlu Sevinç Nihal , Köseoğlu Fitnat
Published: July 2019

The main purpose of this study is to explore the epistemological problems underlying pre-service chemistry teachers’ aims in using practical work, i.e., individual or small group object manipulation or observation, in school science. Twenty-two pre-service chemistry teachers participated in this study. Qualitative data collection tools included participants’ reflections about some practical work cases; participants’ practical work plans; responses given to open-ended questions about practical work, scientific inquiry, the epistemology of science, and science teaching approaches such as discovery and inquiry based learning; and follow-up interviews. Through the qualitative analysis of the data, participants’ aims were grouped under three main themes, which included six categories: providing learning by discovery to students, serving to verify scientific theory, making scientific theories concrete, developing students’ scientific process skills, providing learning about the nature of science, and creating curiosity and motivation towards science. Arguments related to any epistemological problems underlying some of these aims are presented in the Results and discussion section. Based on the results, conclusions were made about the sources of these epistemological problems, why the epistemology of science should be considered explicitly when teaching the science teaching approaches and using the practical work, and why “teaching nature of science implicitly” failed.
An electrochemical immunosensing system on patterned electrodes for immunoglobulin E detection
Authors: Oh Seung Jun , Ahn Jun Ki , Park Hun , Song Yesol , Kwon Seong Jung , Shin Hang-Beum
Published: July 2019

We present an electrochemical biosensing platform which enables immunoglobulin E (IgE) detection from eight independent biological samples. The performance of the electrochemical immunosensor was comparable to the conventional optical assay.
Click and photo-release dual-functional nucleic acid nanostructures
Authors: Valsangkar Vibhav A. , Chandrasekaran Arun Richard , Zhuo Lifeng , Mao Song , Lee Goh Woon , Kizer Megan , Wang Xing , Halvorsen Ken , Sheng Jia
Published: July 2019

DNA nanostructures are useful in drug delivery, with cargos attached via click chemistry and released using light-based triggers.
Small molecule anion transporters display in vitro antimicrobial activity against clinically relevant bacterial strains
Authors: Carreira-Barral Israel , Rumbo Carlos , Mielczarek Marcin , Alonso-Carrillo Daniel , Herran Enara , Pastor Marta , Del Pozo Angel , García-Valverde María , Quesada Roberto
Published: July 2019

Highly active transmembrane anion transporters have demonstrated their activity against antibiotic-resistant and clinically relevant bacterial strains.
High performance benzoimidazolyl-based aminophenolate zinc complexes for isoselective polymerization of rac-lactide
Authors: Gong Yanmei , Ma Haiyan
Published: July 2019

A series of zinc complexes supported by achiral benzoimidazolyl-based aminophenolate ligands were employed as highly active initiators for the ring-opening polymerization of rac-lactide to afford highly isotactic polymers under mild conditions.
Synthesis and carbon dioxide capture properties of flower-shaped zeolitic imidazolate framework-L
Authors: Wang Shaozhen , Zang Biao , Chang Yueyue , Chen Hongqi
Published: July 2019

Flower-shaped zeolitic imidazolate framework-L (ZIF-L) nanostructures were synthesized by a coordination control method. The CO2 adsorption capacity of flower-shaped ZIF-L was 1.15 mmol g−1 at room temperature and 1 bar, which was higher than that of the two-dimensional ZIF-L.
ZSM-5 decrystallization and dealumination in hot liquid water
Authors: Maag Alex R. , Tompsett Geoffrey A. , Tam Jason , Ang Cheen Aik , Azimi Gisele , Carl Alexander D. , Huang Xinlei , Smith Luis J. , Grimm Ronald L. , Bond Jesse Q. , Timko Michael T.
Published: July 2019

ZSM-5 zeolite degrades the crystal surface framework and internal acid sites, dependent on the unique thermophysical nature of water solvent.
Using photoelectron spectroscopy to observe oxygen spillover to zirconia
Authors: Lackner Peter , Zou Zhiyu , Mayr Sabrina , Diebold Ulrike , Schmid Michael
Published: July 2019

Oxygen vacancies in five-monolayer-thick tetragonal ZrO2films can cause core level binding energies up to 1.8 eV higher than in the (near-stoichiometric) monoclinic phase. The vacancies can be healed by oxygen spillover from a metal catalyst.
Nitrogen-doped metal-free carbon catalysts for (electro)chemical CO2conversion and valorisation
Authors: Fernandes Diana M. , Peixoto Andreia F. , Freire Cristina
Published: July 2019

This review focuses on the recent developments made in the fabrication of N-doped carbon materials for enhanced CO2conversion and electrochemical reduction into high-value-added products.
The study of Rh(iii) hydroxocomplexes using capillary zone electrophoresis with a UV–Vis detector: the development of the method
Authors: Volchek Victoria V. , Shuvaeva Olga V. , Berdyugin Semen N. , Vasilchenko Danila B. , Korenev Sergey V.
Published: July 2019

Capillary zone electrophoresis was firstly employed to study a mixture of rhodium(iii) polynuclear hydroxocomplexes.
An excellently stable TbIII–organic framework with outstanding stability as a rapid, reversible, and multi-responsive luminescent sensor in water
Authors: Guo Feng , Su Changhua , Fan Yuhang , Shi Wenbing
Published: July 2019

A multi-response Tb-based metal–organic framework with excellent stability is used as a rapid and reversible luminescent sensor for Fe3+, Cr2O72−, and nitrofurantoin in water.
One-pot synthesis of a new generation of hybrid bisphosphonate polyoxometalate gold nanoparticles as antibiofilm agents
Authors: Tomane S. , López-Maya E. , Boujday S. , Humblot V. , Marrot J. , Rabasso N. , Castells-Gil J. , Sicard C. , Dolbecq A. , Mialane P. , Vallée A.
Published: July 2019

A reduced polyoxovanadate functionalized with alendronate molecules was used for the synthesis of gold nanoparticles; these hybrid nanomaterials exhibit high antibiofilm activity.
Metal–oxygen clusters as peroxidase mimics for their multifarious applications in colorimetric sensors
Authors: Wei Mei-Jie , Fu Jia-Qi , Li Bo , Shao Kui-Zhan , Zang Hong-Ying , Wang Xiao-Hong , Su Zhong-Min
Published: July 2019

Metal–oxygen cluster (Fe28) was certified to own inherent peroxidase-like performance, which displayed multi-functional applications in H2O2, glucose and dopamine detection.
A stable luminescent zinc–organic framework as a dual-sensor toward Cu2+ and Cr2O72−, and excellent platform-encapsulated Ln3+ for systematic color tuning and white-light emission
Authors: Qin Bo-Wen , Zhang Xiao-Ying , Zhang Jing-Ping
Published: July 2019

A stable three-fold interpenetrated framework (Zn-MOF), showing chemical sensing for Cu2+ and Cr2O72−, tunable luminescence and white-light emission after encapsulating lanthanide cations, was synthesized and characterized.
A luminescent inorganic–organic hybrid, [Cd(C16H10N2O8S)(H2O)], for the selective and recyclable detection of chromates and dichromates in aqueous solution
Authors: Kundu Tanaya , Manna Krishna , Jana Ajay K. , Natarajan Srinivasan
Published: July 2019

A three-dimensional inorganic–organic hybrid [Cd(H2L)(H2O)], was shown to exhibit good catalytic activity as well as to detect highly toxic chromate and dichromate anions in aqueous medium with good selectivity.
Strong plasmonic fluorescence enhancement of individual plant light-harvesting complexes
Authors: Kyeyune Farooq , Botha Joshua L. , van Heerden Bertus , Malý Pavel , van Grondelle Rienk , Diale Mmantsae , Krüger Tjaart P. J.
Published: July 2019

Plasmon-enhanced fluorescence for detection of weakly emitting individual photosynthetic pigment-protein complexes.
Graphitic carbon nitride-based nanocomposites and their biological applications: a review
Authors: Chan Ming-Hsien , Liu Ru-Shi , Hsiao Michael
Published: July 2019

Graphitic carbon nitrides present the finest energy gap and catalysis function and can be applied for biosensing, bioimaging, and therapy.
Maghemite nanoparticles stabilize the protein corona formed with transferrin presenting different iron-saturation levels
Authors: Martens Ulrike , Böttcher Dominique , Talbot Delphine , Bornscheuer Uwe , Abou-Hassan Ali , Delcea Mihaela
Published: July 2019

Maghemite nanoparticle-transferrin corona formation depends on the protein–iron-loading and the protein is stabilized by bioconjugation.
A facile route to fabricate thermally conductive and electrically insulating polymer composites with 3D interconnected graphene at an ultralow filler loading
Authors: Song Shiqiang , Wang Jinyuan , Liu Cheng , Wang Jincheng , Zhang Yong
Published: July 2019

A facile route has been developed to prepare highly thermally conductive composites including silicone, styrene–butadiene rubber and epoxy resin matrices.
Correction: Ionic-liquid-bifunctional wrapping of ultrafine SnO2 nanocrystals into N-doped graphene networks: high pseudocapacitive sodium storage and high-performance sodium-ion full cells
Authors: Yang Yan , Pan Zhen-Zhen , Wang Ying-Ying , Ma Yuan-Chuan , Li Chong , Lu Yu-Jun , Wu Xing-Long
Published: July 2019

Correction for ‘Ionic-liquid-bifunctional wrapping of ultrafine SnO2 nanocrystals into N-doped graphene networks: high pseudocapacitive sodium storage and high-performance sodium-ion full cells’ by Yan Yang et al., Nanoscale, 2019, DOI: 10.1039/c9nr02542a.
Poly(2-amino-2-oxazoline)s: a new class of thermoresponsive polymers
Authors: Sedlacek Ondrej , Bera Debaditya , Hoogenboom Richard
Published: July 2019

In this report, we describe the synthesis and properties of poly(2-dialkylamino-2-oxazoline)s (PAmOx), a new class of thermoresponsive polymers.