bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biopolymer Skeleton Produced by Rhizobium radiobacter: Stoichiometric Alternation of Glycosidic and Amidic Bonds in the Lipopolysaccharide O‐Antigen
Authors: Speciale Immacolata , Di Lorenzo Flaviana , Gargiulo Valentina , Erbs Gitte , Newman Mari‐Anne , Molinaro Antonio , De Castro Cristina 
Published: February 2020

AbstractThe lipopolysaccharide (LPS) O‐antigen structure of the plant pathogen Rhizobium radiobacter strain TT9 and its possible role in a plant‐microbe interaction was investigated. The analyses disclosed the presence of two O‐antigens, named Poly1 and Poly2. The repetitive unit of Poly2 constitutes a 4‐α‐l‐rhamnose linked to a 3‐α‐d‐fucose residue. Surprisingly, Poly1 turned out to be a novel type of biopolymer in which the repeating unit is formed by a monosaccharide and an amino‐acid derivative, so that the polymer has alternating glycosidic and amidic bonds joining the two units: 4‐amino‐4‐deoxy‐3‐O‐methyl‐d‐fucose and (2′R,3′R,4′S)‐N‐methyl‐3′,4′‐dihydroxy‐3′‐methyl‐5′‐oxoproline). Differently from the O‐antigens of LPSs from other pathogenic Gram‐negative bacteria, these two O‐antigens do not activate the oxidative burst, an early innate immune response in the model plant Arabidopsis thaliana, explaining at least in part the ability of this R. radiobacter strain to avoid host defenses during a plant infection process.
Co‐syndiospecific Alternating Copolymerization of Functionalized Propylenes and Styrene by Rare‐Earth Catalysts
Authors: Wang Haobing , Wu Xia , Yang Yang , Nishiura Masayoshi , Hou Zhaomin 
Published: February 2020

AbstractThe precise control of monomer sequence and stereochemistry in copolymerization is of much interest and importance for the synthesis of functional polymers, but studies toward this goal have met with only limited success to date. Now, the co‐syndiospecific alternating copolymerization of methoxyphenyl‐ and N,N‐dimethylaminophenyl‐functionalized propylenes with styrene by half‐sandwich rare‐earth catalysts is reported. This reaction efficiently afforded the corresponding functionalized propylene‐alt‐styrene copolymers with a perfect alternating sequence and excellent co‐syndiotacticity (rrrr >99 %), thus constituting the first example of co‐stereospecific alternating copolymerization of polar and non‐polar olefins.
A Water‐Stable Ionic MOF for the Selective Capture of Toxic Oxoanions of SeVI and AsV and Crystallographic Insight into the Ion‐Exchange Mechanism
Authors: Sharma Shivani , Desai Aamod V. , Joarder Biplab , Ghosh Sujit K. 
Published: February 2020

AbstractSelectively capturing toxic oxoanions of selenium and arsenic is highly desired for the remediation of hazardous waste. Ionic metal–organic frameworks (iMOFs) especially cationic MOFs (iMOF‐C) as ion‐exchange materials, featuring aqueous phase stability, present a robust pathway for sequestration of the oxoanions owing to their ability to prevent leaching because of their ionic nature. On account of scarcity of water‐stable cationic MOFs, the capture of oxoanions of selenium and arsenic has been a major challenge and has not been investigated using iMOFs. Herein, we demonstrate large scale synthesis of cationic MOF, viz. iMOF‐1C that exhibits selective capture of oxoanions of SeVI (SeO42−) and AsV (HAsO42−) in water with a maximum sorption capacity of 100 and 85 mg g−1, respectively. This represents among the highest uptake capacities observed for selenate oxoanion in MOFs. Further, the ion‐exchange mechanism was directly unveiled by single crystal analysis, which revealed variable modes of host–guest binding.
Pseudo‐Stereodivergent Synthesis of Enantioenriched Tetrasubstituted Alkenes by Cascade 1,3‐Oxo‐Allylation/Cope Rearrangement
Authors: Chen Peng , Li Yue , Chen Zhi‐Chao , Du Wei , Chen Ying‐Chun 
Published: February 2020

AbstractThe catalytic diastereodivergent construction of stereoisomers having two or more stereogenic centers has been extensively studied. In contrast, the switchable introduction of another stereogenic element, that is,Z/Econfiguration involving a polysubstituted alkene group, into the optically active stereoisomers, has not been recognized yet. Disclosed here is the pseudo‐stereodivergent synthesis of highly enantioenriched tetrasubstituted alkene architectures from isatin‐based Morita–Baylis–Hillman carbonates and allylic derivatives, under the cooperative catalysis of a tertiary amine and a chiral iridium complex. The success of the switchable construction of the tetrasubstituted alkene motif relies on the diastereodivergent 1,3‐oxo‐allylation reaction between N‐allylic ylides and chiral π‐allyliridium complex intermediates by ligand and substrate control, followed by the stereoselective concerted 3,3‐Cope rearrangement process.
Transcriptomic analysis at the first instar larval stage of nonmolting Bombyx mori mutant (a42)
Authors: Sun Xia , Zhang Kaixiang , Qin Sheng , Zhang Guozheng , Li Muwang 
Published: February 2020

AbstractThe life cycle of the holometabolous insect Bombyx mori (Linnaeus) consists of the embryo, larva, pupa, and adult stages with six larval molts. Ecdysone and juvenile hormones play important roles in the growth and development of the silkworms. The a42 silkworm mutant is recessive and homozygous lethal by exhibiting a dark‐colored and small body size and fails to molt to second instar. We compared the gene expression of a42 mutants with normal individuals at the first larval molting stage to elucidate the physiological influence of the a42 mutation on the growth and development of silkworms. The transcriptomic sequencing results revealed that 1,411 genes are differentially expressed in a42 mutants, compared with wild‐type control silkworms, in which 791 genes are upregulated and 620 genes are downregulated. Gene Ontology/Kyoto Encyclopedia of Genes and Genomes analyses identified differentially expressed genes (DEGs) assigned to biological pathways, such as pentose and glucoronate interconversions, glycerolipid metabolism, folate biosynthesis, amino sugar, and nucleotide sugar metabolism. Two hydroxylases of phenylalanine hydroxylase (BmPAH) and tyrosine hydroxylase (BmTh) are upregulated in a42 mutants. The influence of a42 mutation on these DEGs reveals that melanin metabolism plays an important role during the molting process in silkworms.
Novel pyrazolo[3,4‐d]pyrimidine derivatives inhibit human cancer cell proliferation and induce apoptosis by ROS generation
Authors: Gaonkar Supreet , Savanur Mohammed Azharuddin , Nadaf AfraQuasar A. , Najare Mahesh S. , Mantur Shivaraj , Garbhagudi Manjunatha , Mulla Sikandar I. , Khazi Imtiyaz Ahmed M. 
Published: February 2020

AbstractThe paucity of effective anticancer drugs for successful treatment is a major concern, indicating the strong need for novel therapeutic compounds. In the quest of new molecules, the present study aimed to explore the potential of pyrazolo[3,4‐d]pyrimidine derivatives as antiproliferative agents. In vitro anticancer screening of selected compounds was done by the National Cancer Institute's Developmental Therapeutics Programme against a panel of 60 cancer cell lines. The lead compound PP‐31d considerably inhibited the growth of cancer cells, such as NCI‐H460 (non‐small‐cell lung cancer), OVCAR‐4 (ovarian cancer), 786‐0 (renal cancer), A549 (non‐small‐cell lung cancer), and ACHN (renal cancer), showing strong anticancer potential, among other derivatives. Kinetic studies of PP‐31d on NCI‐H460 cells revealed a dose‐dependent effect with an IC50 of 2 µM. The observed inhibition by PP‐31d is attributed to the generation of reactive oxygen species and the subsequent induction of cellular apoptosis, as evidenced by the increase in the hypodiploid (subG1) population, the early apoptotic cell population, and caspase‐3/7 activity, the loss of the mitochondrial membrane potential, and the degradation of nuclear DNA. Collectively, our results demonstrated that pyrazolo[3,4‐d]pyrimidine derivatives inhibit cancer cell proliferation by inducing apoptosis and, thus, have the potential to be further explored for anticancer properties.
Reduced White Matter Integrity and Deficits in Neuropsychological Functioning in Adults With Autism Spectrum Disorder
Authors: Haigh Sarah M. , Keller Timothy A. , Minshew Nancy J. , Eack Shaun M. 
Published: February 2020

Autism spectrum disorder (ASD) is currently viewed as a disorder of cortical systems connectivity, with a heavy emphasis being on the structural integrity of white matter tracts. However, the majority of the literature to date has focused on children with ASD. Understanding the integrity of white matter tracts in adults may help reveal the nature of ASD pathology in adulthood and the potential contributors to cognitive impairment. This study examined white matter water diffusion using diffusion tensor imaging in relation to neuropsychological measures of cognition in a sample of 45 adults with ASD compared to 20 age, gender, and full‐scale‐IQ‐matched healthy volunteers. Tract‐based spatial statistics were used to assess differences in diffusion along white matter tracts between groups using permutation testing. The following neuropsychological measures of cognition were assessed: processing speed, attention vigilance, working memory, verbal learning, visual learning, reasoning and problem solving, and social cognition. Results indicated that fractional anisotropy (FA) was significantly reduced in adults with ASD in the anterior thalamic radiation (P = 0.022) and the right cingulum (P = 0.008). All neuropsychological measures were worse in the ASD group, but none of the measures significantly correlated with reduced FA in either tract in the adults with ASD or in the healthy volunteers. Together, this indicates that the tracts that are the most impacted in autism may not be (at least directly) responsible for the behavioral deficits in ASD. Autism Res 2020, 13: 702–714. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryWhite matter tracts are the data cables in the brain that efficiently transfer information, and damage to these tracts could be the cause for the abnormal behaviors that are associated with autism. We found that two long‐range tracts (the anterior thalamic radiation and the cingulum) were both impaired in autism but were not directly related to the impairments in behavior. This suggests that the abnormal tracts and behavior are the effects of another underlying mechanism.
Distinctive lung cancer incidence trends among men and women attributable to the period effect in Shanghai: An analysis spanning 42 years
Authors: Xie Li , Qian Ying , Liu Yishan , Li Yixuan , Jia Sinong , Yu Herbert , Wang Chunfang , Qian Biyun , Bao Pingping 
Published: February 2020

AbstractBackgroundMany previous studies reported secular trend of lung cancer incidence and mortality, but little is known about the possible reasons for these trends.MethodsData were obtained from Shanghai Cancer Registry. Age‐standardized rates were calculated and average annual percent changes (AAPCs) were evaluated by Joinpoint regression. Age, period, and birth cohort effects were assessed by age‐period‐cohort models.ResultsFrom 1973 to 2010, compared with long‐time slowly increasing trend in women, male lung cancer incidence had significantly decreased between 2001 and 2009. After that lung cancer incidence rising sharply in women (AAPC = 14.13%, 95%CI: 2.68%‐26.86%, P = .016) and similar rising trends without statistical significance in men (AAPC = 2.96, 95%CI: −2.47%‐8.69%, P = .281) between 2010 and 2014. Age‐period cohort model showed the different patterns of period effects for lung cancer incidence between men and women. The period effects for lung cancer incidence showed rising effect for women, whereas there was decline effect for lung cancer incidence for men. On the other hand, the model showed a significant period effect in both genders with a similar fashion in mortality, yielding steady falling trends during the entire study period.ConclusionsThe distinctive patterns of lung cancer incidence between men and women may be attributable to significant period effects, which reflected the changes in public health policies or diagnostic practices and highlighted the urgent of continued monitoring of gender‐specific risk factors for lung cancer incidence.
Experimental study of the vascular normalization window for tumors treated with apatinib and the efficacy of sequential chemotherapy with apatinib in lung cancer‐bearing mice and patients
Authors: Liu Mingtao , Li Hui , Wang Xiuxiu , Jing Lijun , Jiang Peng , Li Yu 
Published: February 2020

AbstractIn the tumor vascular system, the vascular structure is disordered, the morphology is abnormal, and the structure of the blood vessel walls is incomplete, leading to leakage of the blood vessel wall, elevated interstitial fluid pressure, and elevated blood flow resistance. These alterations lead to local microenvironmental changes, which mainly manifest as a lack of oxygen and acidosis, further affecting the efficacy of chemotherapy drugs. Antiangiogenic drugs can normalize the abnormalities caused by tumor angiogenesis, thereby transferring oxygen and drugs to tumor cells more efficiently through normalized blood vessels and enhancing the efficacy of chemotherapy drugs. Apatinib is a specific VEGFR‐2 inhibitor that blocks the transmission of the VEGF/VEGFR‐2 signaling pathway. In this study, we constructed a nude mouse xenograft model of lung cancer and administered apatinib at different doses and times to detect the normalization of reactive blood vessels through VEGF, α‐SMA, college‐IV, HIF‐1α, and MMP. The ultrastructure of tumor blood vessels was observed by electron microscopy, and the dose and timing of apatinib‐induced normalization of lung cancer in nude mice were confirmed. Then, we observed the inhibitory effect of apatinib combined with pemetrexed on transplanted tumors of lung cancer cells in nude mice at different time points and observed whether combination pemetrexed chemotherapy showed more significant effects in the time window of vascular normalization induced by apatinib. The inhibition of the growth of transplanted tumors was examined. Then 20 patients with advanced non–small cell lung cancer were enrolled, and apatinib sequential chemotherapy drugs were applied as a third‐line chemotherapy regimen to observe its clinical efficacy.
Treatment of Gingival Fenestration With a Double Pedicle Flap Approach and Dehydrated Amnion–Chorion Membrane: A Case Report
Authors: Bhide Vinay M. , Tenenbaum Howard C. 
Published: February 2020

IntroductionAlthough gingival fenestrations (GFs) occur with relative infrequency, their actual incidence is thought to be much higher. Furthermore, if left untreated, these mucogingival defects can lead to unfavorable sequelae which can compromise the esthetics and stability of the teeth affected. Most GFs require surgical treatment for closure. Previously reported modalities of treatment include connective tissue grafting, acellular dermal matrix allograft, and pedicle flap approaches. This case demonstrates the first documented use of a dehydrated amnion‐chorion membrane (dHACM) to treat GF.Case PresentationA surgical approach involving a double pedicle flap and dHACM with 15 months follow‐up is described. Following gentle cleansing of the defect and careful split‐thickness elevation of a double pedicle flap, the area of exposure fenestration was covered with dHACM. The overlying flap was then closed carefully to completely cover the dHACM. The case presented shows a successful clinical outcome as characterized by successful closure of the fenestration defect with nice tissue maturation.ConclusionThe technique described in this case report demonstrates that GFs can be successfully treated with a periodontal plastic surgical approach using dHACM with minimal patient discomfort.
Flowcharts for Easy Periodontal Diagnosis Based on the 2018 New Periodontal Classification
Authors: Sutthiboonyapan Pimchanok , Wang Hom‐Lay , Charatkulangkun Orawan 
Published: February 2020

Focused Clinical QuestionHow can a clinician simply and quickly perform a periodontal screening and make a proper periodontal diagnosis using the 2018 proposed new periodontal classification?SummaryThe 2018 periodontal classification has been released, however, it is challenging for clinicians especially for the dental students to apply the published information in practice. A diagnostic flowchart was created for three of the most common periodontal conditions: health, gingivitis, and periodontitis. Additionally, flowcharts were proposed for the diagnosis of periodontitis severity and risk of progression by staging and grading. Probing depth was the first clinical parameter to categorize the type of diseases. Subsequently, bleeding on probing, radiographic bone loss/clinical attachment loss, and history of periodontal treatment were further added for making a proper diagnosis. Three clinical cases were given to demonstrate the use of the simplified proposed flowcharts.ConclusionsThe proposed diagnostic flowcharts are the user‐friendly tool to assist clinicians to perform an initial screening and diagnosis based on the 2018 newly proposed periodontal disease classification.
Facile Access to Dative, Single, and Double Silicon−Metal Bonds Through M−Cl Insertion Reactions of Base‐Stabilized SiII Cations
Authors: Frisch Philipp , Szilvási Tibor , Inoue Shigeyoshi 
Published: February 2020

AbstractSilicon(II) cations can offer fascinating reactivity patterns due to their unique electronic structure: a lone pair of electrons, two empty p orbitals and a positive charge combined on a single silicon center. We now report the facile insertion of N‐heterocyclic carbene (NHC)‐stabilized silyliumylidene ions into M−Cl bonds (M=Ru, Rh), forming a series of novel chlorosilylene transition‐metal complexes. Theoretical investigations revealed a reaction mechanism in which the insertion into the M−Cl bond with concomitant 1,2‐migration of a silicon‐bound NHC to the transition metal takes place after formation of an initial silyliumylidene transition‐metal complex. The mechanism could be verified experimentally through characterization of the intermediate complexes. Furthermore, the obtained chlorosilylene complexes can be conveniently utilized as synthons to access Si−M and Si=M bonding motifs bonds through reductive dehalogenation.
Neutrophil‐like HL‐60 cells expressing only GFP‐tagged β‐actin exhibit nearly normal motility
Authors: Garner Rikki M. , Skariah Gemini , Hadjitheodorou Amalia , Belliveau Nathan M. , Savinov Andrew , Footer Matthew J. , Theriot Julie A. 
Published: February 2020

AbstractObservations of actin dynamics in living cells using fluorescence microscopy have been foundational in the exploration of the mechanisms underlying cell migration. We used CRISPR/Cas9 gene editing to generate neutrophil‐like HL‐60 cell lines expressing GFP‐β‐actin from the endogenous locus (ACTB). In light of many previous reports outlining functional deficiencies of labeled actin, we anticipated that HL‐60 cells would only tolerate a monoallelic edit, as biallelic edited cells would produce no normal β‐actin. Surprisingly, we recovered viable monoallelic GFP‐β‐actin cells as well as biallelic edited GFP‐β‐actin cells, in which one copy of the ACTB gene is silenced and the other contains the GFP tag. Furthermore, the edited cells migrate with similar speeds and persistence as unmodified cells in a variety of motility assays, and have nearly normal cell shapes. These results might partially be explained by our observation that GFP‐β‐actin incorporates into the F‐actin network in biallelic edited cells at similar efficiencies as normal β‐actin in unedited cells. Additionally, the edited cells significantly upregulate γ‐actin, perhaps helping to compensate for the loss of normal β‐actin. Interestingly, biallelic edited cells have only modest changes in global gene expression relative to the monoallelic line, as measured by RNA sequencing. While monoallelic edited cells downregulate expression of the tagged allele and are thus only weakly fluorescent, biallelic edited cells are quite bright and well‐suited for live cell microscopy. The nondisruptive phenotype and direct interpretability of this fluorescent tagging approach make it a promising tool for studying actin dynamics in these rapidly migrating and highly phagocytic cells.
Beyond Beer's Law: Why the Index of Refraction Depends (Almost) Linearly on Concentration
Authors: Mayerhöfer Thomas G. , Dabrowska Alicja , Schwaighofer Andreas , Lendl Bernhard , Popp Jürgen 
Published: February 2020

AbstractBeer's empiric law states that absorbance is linearly proportional to the concentration. Based on electromagnetic theory, an approximately linear dependence can only be confirmed for comparably weak oscillators. For stronger oscillators the proportionality constant, the molar attenuation coefficient, is modulated by the inverse index of refraction, which is itself a function of concentration. For comparably weak oscillators, the index of refraction function depends, like absorbance, linearly on concentration. For stronger oscillators, this linearity is lost, except at wavenumbers considerably lower than the oscillator position. In these transparency regions, linearity between the change of the index of refraction and concentration is preserved to a high degree. This can be shown with help of the Kramers–Kronig relations which connect the integrated absorbance to the index of refraction change at lower wavenumbers than the corresponding band. This finding builds the foundation not only for refractive index sensing, but also for new interferometric approaches in IR spectroscopy, which allow measuring the complex index of refraction function.
Assessing Neuron–Astrocyte Spatial Interactions Using the Neuron–Astrocyte Proximity Assay
Authors: Badia‐Soteras Aina , Octeau J. Christopher , Verheijen Mark H. G. , Khakh Baljit S. 
Published: February 2020

AbstractAstrocytes are morphologically complex cells with numerous close contacts with neurons at the level of their somata, branches, and branchlets. The smallest astrocyte processes make discrete contacts with synapses at scales that cannot be observed by standard light microscopy. At such contact points, astrocytes are thought to perform both homeostatic and neuromodulatory roles—functions that are proposed to be determined by their close spatial apposition. To study such spatial interactions, we previously developed a Förster resonance energy transfer (FRET)–based approach, which enables observation and tracking of the static and dynamic proximity of astrocyte processes with synapses. The approach is compatible with standard imaging techniques such as confocal microscopy and permits assessment of the most proximate contacts between astrocytes and neurons in live tissues. In this protocol article we describe the approach to analyze the contacts between striatal astrocyte processes and corticostriatal neuronal projection terminals onto medium spiny neurons. We report the required protocols in detail, including adeno‐associated virus microinjections, acute brain slice preparation, imaging, and post hoc FRET quantification. The article provides a detailed description that can be used to characterize and study astrocyte process proximity to synapses in living tissue. © 2020 by John Wiley & Sons, Inc.Basic Protocol 1: Förster resonance energy transfer imaging in cultured cellsBasic Protocol 2: Förster resonance energy transfer imaging with the neuron–astrocyte proximity assay in acute brain slices