bluuebunny/crossref_metadata_2025 huggingface dataset:
Riding the Rails to (Un)Freedom: Colson Whitehead’s The Underground Railroad
Authors: González Groba Constante
Published: May 2020

This novel about US black slavery departs from realism, moving around in time and space as a means of dealing with different racial terrors in different historical periods. One of the author’s intentions is to make us think about slavery not just in the past but with reverberations for the present. Published in 2016, the novel resonates with a contemporary America characterized by acrimonious racial division.

After escaping from a Georgia plantation through a literalized Underground Railroad, the adolescent female protagonist soon learns that freedom remains elusive in states further north, even those where slavery has been abolished. The novel fuses the odyssey of Cora with the history and mythology of America, and asserts the inseparability of slavery from American capitalism and the building of empire.

Cora explores both the Declaration of Independence and the Bible, two foundational texts of the nation, in a novel that addresses some of the foundational sins of America. Hers is the all-American story of escape to freedom, but her journey takes her through ever darker varieties of depredation and oppression. She becomes an American dreamer in the sense that she never accepts her place in a system that she persists in defying, and through this process becomes a fictional representation of black people who, with their relentless pursuit of freedom, contributed so greatly to the building of American democracy.
Form and Diversity in American Crime Fiction:The Southern Forensic Thriller
Authors: Avanzas Álvarez Elena
Published: May 2020

The forensic thriller has traditionally been constructed as a mainstream American narrative focused on the stereotypical representation of the country as a metropolis with an incredible amount of resources, and the American capitalist dream. The author Patricia Cornwell (Postmortem, first novel in the Kay Scarpetta series, published in 1990) is considered the founding mother of this crime fiction subgenre native to the US, closely followed by Kathy Reichs (Deja Dead, first novel in the Temperance Brennan series, published in 1997) whose series have been successfully adapted to television in the show Bones (2005-2017). But the 21st century has seen the inclusion of more diverse settings for these stories, the South being the most economically successful and dominated by women authors too. Georgian Karin Slaughter is the author of the “Grant County” series, set in the fictional town of Heartsdale, in rural Georgia, and responsible for the inscription of the South in American forensic thrillers thanks to her own experience as a native. Blindsighted (2001) includes elements from both the grotesque southern gothic and the hard boiled tradition. My analysis of the first novel in the series will examine how the southern environment becomes quintessential to the development of the crimes and the characters from a literary, philosophical and feminist point of view. The issues examined will include, but not be limited to crime, morals, religion, professional ambition, infidelity, divorce, sexual desire, infertility, and family relationships.
Nuclei determine the spatial origin of mitotic waves
Authors: Nolet Felix E , Vandervelde Alexandra , Vanderbeke Arno , Piñeros Liliana , Chang Jeremy B , Gelens Lendert
Published: May 2020

Traveling waves play an essential role in coordinating mitosis over large distances, but what determines the spatial origin of mitotic waves remains unclear. Here, we show that such waves initiate at pacemakers, regions that oscillate faster than their surroundings. In cell-free extracts of Xenopus laevis eggs, we find that nuclei define such pacemakers by concentrating cell cycle regulators. In computational models of diffusively coupled oscillators that account for nuclear import, nuclear positioning determines the pacemaker location. Furthermore, we find that the spatial dimensions of the oscillatory medium change the nuclear positioning and strongly influence whether a pacemaker is more likely to be at a boundary or an internal region. Finally, we confirm experimentally that increasing the system width increases the proportion of pacemakers at the boundary. Our work provides insight into how nuclei and spatial system dimensions can control local concentrations of regulators and influence the emergent behavior of mitotic waves.
SARS-CoV-2 strategically mimics proteolytic activation of human ENaC
Authors: Anand Praveen , Puranik Arjun , Aravamudan Murali , Venkatakrishnan AJ , Soundararajan Venky
Published: May 2020

Molecular mimicry is an evolutionary strategy adopted by viruses to exploit the host cellular machinery. We report that SARS-CoV-2 has evolved a unique S1/S2 cleavage site, absent in any previous coronavirus sequenced, resulting in the striking mimicry of an identical FURIN-cleavable peptide on the human epithelial sodium channel α-subunit (ENaC-α). Genetic alteration of ENaC-α causes aldosterone dysregulation in patients, highlighting that the FURIN site is critical for activation of ENaC. Single cell RNA-seq from 66 studies shows significant overlap between expression of ENaC-α and the viral receptor ACE2 in cell types linked to the cardiovascular-renal-pulmonary pathophysiology of COVID-19. Triangulating this cellular characterization with cleavage signatures of 178 proteases highlights proteolytic degeneracy wired into the SARS-CoV-2 lifecycle. Evolution of SARS-CoV-2 into a global pandemic may be driven in part by its targeted mimicry of ENaC-α, a protein critical for the homeostasis of airway surface liquid, whose misregulation is associated with respiratory conditions.
Implied Evidence of the Functional Role of the Rectus Capitis Posterior Muscles
Authors: Hallgren Richard C. , Rowan Jacob J.
Published: May 2020

Context

Osteopathic physicians often target the rectus capitis posterior minor (RCPm) and rectus capitis posterior major (RCPM) muscles when using muscle energy or soft tissue cervical techniques to treat patients with head and neck pain. The RCPm and RCPM muscles are located deep within the posterior occipitoatlantal and atlantoaxial interspaces, respectively.

Objective

To characterize the functional role of RCPm and RCPM muscles by comparing electromyographic (EMG) activation patterns of these muscles with EMG activation patterns of specific flexor and extensor muscles of the head and neck, the sternocleidomastoid (SCM), and the splenius capitis (SC) muscles, respectively.

Methods

Asymptomatic participants were recruited from the Michigan State University College of Osteopathic Medicine student body. Disposable 25-gauge, bipolar fine-wire intramuscular electrodes were used to collect EMG data from the right and left RCPm and RCPM muscles. Surface electrodes were used to collect EMG data from the right and left SCM and SC muscles. Data were collected as participants performed 4 cycles of flexion and extension with an external 4-lb force applied to the back of the head and the forehead.

Results

In RCPM muscles, EMG activity was significantly greater (P<.003) during flexion and extension of the head and neck when an external force was applied to the back of the head. EMG activity in SCM muscles was significantly greater (P<.0001) during flexion and extension of the head and neck when an external force was applied to the forehead. The authors observed that EMG activity in SC muscles was significantly greater (P<.015) during flexion and extension of the head and neck when an external force was applied to the back of the head. No significant difference was found in EMG activity in RCPm muscles (P<.834) during flexion and extension of the head and neck, regardless of whether the external force was applied to the back of the head or the forehead.

Conclusion

The EMG activation patterns of the RCPm muscles suggest that their functional role may be to stabilize the occipitoatlantal joint by helping maintain congruency of the joint surfaces. In contrast, the EMG activation patterns of the RCPM muscles suggest that their functional role may be to contribute to extension of the head, primarily at the occipitoatlantal and the atlantoaxial joints.
“Reflexivity of reflexivity” with Roma-related Nordic educational research
Authors: Țîștea Ioana
Published: May 2020

In this article, I reflect on the various uses of reflexivity in Roma-related educational research focusing on the Nordic context, in my own and other authors’ writings. I respond to the call of the recently founded Critical Romani Studies journal for reflexivity, which has been raised since mostly non-Romani scholars produce Roma-related research. I purposefully selected 34 academic texts, which I closely read in relation to various research paradigms and their typologies of reflexivity, after which I further reflected on my own readings. The article contributes to recent debates arguing for reflecting on uses of reflexivity, or for a reflexivity of reflexivity, as a strategy to address the reproduction of epistemic privileges in research.
Situating Boundary Work: Chronic Disease Prevention in Danish Hospitals
Authors: Pedersen Inge Kryger
Published: May 2020

Noncommunicable diseases, such as type 2 diabetes, are the leading cause of death globally. This paper focuses on the boundary work among health professions involved in lifestyle-related preventive measures at Danish hospitals. Drawing on documents, qualitative in-depth interviews and extended conversations conducted with health professionals about goals, dilemmas, and practices related to lifestyle disease prevention, as well as site visits at Danish hospitals, it is identified which professional groups have claimed responsibility for the tasks, how they are defined, and through what kinds of interactions and infighting. The analysis grounds Abbott’s framework of jurisdictions and his meso-level vocabulary in a situated account of professional boundary work and follow the way nurses in particular create, and sometimes stabilize or standardize techniques for prevention of lifestyle-related diseases. It is demonstrated by different forms of boundary work how nurses work to extend, defend or refashion established work boundaries when handling these new tasks.
Bioinformatics profiling identifies seven immune-related risk signatures for hepatocellular carcinoma
Authors: Xue Feng , Yang Lixue , Dai Binghua , Xue Hui , Zhang Lei , Ge Ruiliang , Sun Yanfu
Published: May 2020

Background

Density of tumor infiltrating lymphocytes (TIL) and expressions of certain immune-related genes have prognostic and predictive values in hepatocellular carcinoma (HCC); however, factors determining the immunophenotype of HCC patients are still unclear. In the current study, the transcript sequencing data of liver cancer were systematically analyzed to determine an immune gene marker for the prediction of clinical outcome of HCC.

Methods

RNASeq data and clinical follow-up information were downloaded from The Cancer Genome Atlas (TCGA), and the samples were assigned into high-stage and low-stage groups. Immune pathway-related genes were screened from the Molecular Signatures Database v4.0 (MsigDB) database. LASSO regression analysis was performed to identify robust immune-related biomarkers in predicting HCC clinical outcomes. Moreover, an immune gene-related prognostic model was established and validated by test sets and Gene Expression Omnibus (GEO) external validation sets.

Results

We obtained 319 immune genes from MsigDB, and the genes have different expression profiles in high-stage and low-stage of HCC. Univariate survival analysis found that 17 genes had a significant effect on HCC prognosis, among them, 13 (76.5%) genes were prognostically protective factors. Further lasso regression analysis identified seven potential prognostic markers (IL27, CD1D, NCOA6, CTSE, FCGRT, CFHR1, and APOA2) of robustness, most of which are related to tumor development. Cox regression analysis was further performed to establish a seven immune gene signature, which could stratify the risk of samples in training set, test set and external verification set (p < 0.01), and the AUC in both training set and test set was greater than 0.85, which also greater compared with previous studies.

Conclusion

This study constructed a 7-immunogenic marker as novel prognostic markers for predicting survival of HCC patients.
Effective connectivity differences in motor network during passive movement of paretic and non-paretic ankles in subacute stroke patients
Authors: Nagy Marianna , Aranyi Csaba , Opposits Gábor , Papp Tamás , Lánczi Levente , Berényi Ervin , Vér Csilla , Csiba László , Katona Péter , Spisák Tamás , Emri Miklós
Published: May 2020

Background

A better understanding of the neural changes associated with paresis in stroke patients could have important implications for therapeutic approaches. Dynamic Causal Modeling (DCM) for functional magnetic resonance imaging (fMRI) is commonly used for analyzing effective connectivity patterns of brain networks due to its significant property of modeling neural states behind fMRI signals. We applied this technique to analyze the differences between motor networks (MNW) activated by continuous passive movement (CPM) of paretic and non-paretic ankles in subacute stroke patients. This study aimed to identify CPM induced connectivity characteristics of the primary sensory area (S1) and the differences in extrinsic directed connections of the MNW and to explain the hemodynamic differences of brain regions of MNW.

Methods

For the network analysis, we used ten stroke patients’ task fMRI data collected under CPMs of both ankles. Regions for the MNW, the primary motor cortex (M1), the premotor cortex (PM), the supplementary motor area (SMA) and the S1 were defined in a data-driven way, by independent component analysis. For the network analysis of both CPMs, we compared twelve models organized into two model-families, depending on the S1 connections and input stimulus modeling. Using DCM, we evaluated the extrinsic connectivity strengths and hemodynamic parameters of both stimulations of all patients.

Results

After a statistical comparison of the extrinsic connections and their modulations of the “best model”, we concluded that three contralateral self-inhibitions (cM1, cS1 and cSMA), one contralateral inter-regional connection (cSMA→cM1), and one interhemispheric connection (cM1→iM1) were significantly different. Our research shows that hemodynamic parameters can be estimated with the Balloon model using DCM but the parameters do not change with stroke.

Conclusions

Our results confirm that the DCM-based connectivity analyses combined with Bayesian model selection may be a useful technique for quantifying the alteration or differences in the characteristics of the motor network in subacute stage stroke patients and in determining the degree of MNW changes.
Comprehensive analysis reveals a metabolic ten-gene signature in hepatocellular carcinoma
Authors: Zhu Zhipeng , Li Lulu , Xu Jiuhua , Ye Weipeng , Chen Borong , Zeng Junjie , Huang Zhengjie
Published: May 2020

Background

Due to the complicated molecular and cellular heterogeneity in hepatocellular carcinoma (HCC), the morbidity and mortality still remains high level in the world. However, the number of novel metabolic biomarkers and prognostic models could be applied to predict the survival of HCC patients is still small. In this study, we constructed a metabolic gene signature by systematically analyzing the data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC).

Methods

Differentially expressed genes (DEGs) between tumors and paired non-tumor samples of 50 patients from TCGA dataset were calculated for subsequent analysis. Univariate cox proportional hazard regression and LASSO analysis were performed to construct a gene signature. The Kaplan–Meier analysis, time-dependent receiver operating characteristic (ROC), Univariate and Multivariate Cox regression analysis, stratification analysis were used to assess the prognostic value of the gene signature. Furthermore, the reliability and validity were validated in four types of testing cohorts. Moreover, the diagnostic capability of the gene signature was investigated to further explore the clinical significance. Finally, Go enrichment analysis and Gene Set Enrichment Analysis (GSEA) have been performed to reveal the different biological processes and signaling pathways which were active in high risk or low risk group.

Results

Ten prognostic genes were identified and a gene signature were constructed to predict overall survival (OS). The gene signature has demonstrated an excellent ability for predicting survival prognosis. Univariate and Multivariate analysis revealed the gene signature was an independent prognostic factor. Furthermore, stratification analysis indicated the model was a clinically and statistically significant for all subgroups. Moreover, the gene signature demonstrated a high diagnostic capability in differentiating normal tissue and HCC. Finally, several significant biological processes and pathways have been identified to provide new insights into the development of HCC.

Conclusion

The study have identified ten metabolic prognostic genes and developed a prognostic gene signature to provide more powerful prognostic information and improve the survival prediction for HCC.
The Bombay Blood Group: How Rare is It? A Case Report and a Review of the Literature
Authors: Ekanem Emmanuel , Poozhikalayil Santosh , Sinha Anita
Published: May 2020

The Bombay blood group is a rare type of blood group which is very distinct from the ABO system and was first discovered in India about five decades ago. This blood group describes individuals who lack the H antigen and thus present with the anti H antibodies in addition to anti A and anti B antibodies. Bombay blood group is sometimes mistaken for blood group O. The significance of this blood group is in its ability to potentially cause fatal blood transfusion reaction and haemolytic disease of the foetus and the neonate.

Aim: This case report aims to elucidate the rare occurrence of the Bombay blood group.

Methods: We describe a case report of the pregnancy, labour and delivery of a multiparous Indian woman with the Bombay blood group in her second pregnancy.

Results: The index case had an uneventful pregnancy, labour and delivery without the need for blood transfusion. The neonate was Rhesus D positive and did not have any complications.

Conclusion: Bombay blood group is a rare blood group which can lead to blood transfusion reactions and haemolytic disease of the foetus and newborn. Pregnancy, labour and delivery should be managed in a unit with the availability of anti H blood to avoid foetal and maternal complications.
Effect of Bacillus subtilis QM3 on β-amylase Isoenzyme in Early Germination of Wheat Seed
Authors: Li Ya-Jing , Hu Qing-Ping
Published: May 2020

Seed germination is the basis and initial stage in the process of plant growth and development. Bacillus subtilis QM3 is a plant growth promoting rhizobacterium (PGPR) with function of growth promoting, promoting, prevention of pathogens and pests attack and can improve plant resistance to different stress factors. Through the measurement of the early germination rate of wheat (Triticum aestivam L.). seeds under B. subtilis QM3 treatment, the results showed that B. subtilis QM3 can significantly promote the germination of wheat seeds, which has reached a significant level at 6h after seeds sowing or at 6 h of treatment, during imbibition. The β-amylase isoenzyme in early period of wheat seed germination was measured by denaturing polyacrylamide gel electrophoresis. The results showed that the band width and brightness of β-amylase isoenzyme of wheat seeds treated with B. subtilis QM3 increased during three to 6 h of imbibition and especially the effect was significant at 6 h. In the early period, the band of α-amylase isoenzyme could not be detected. It is suggested that the increase of β-amylase isoenzyme early band may be one of the main reasons for B. subtilis QM3 to promote wheat seed germination. Through the combination of B. subtilis QM3 with free and binding states of β-amylase, it was found that the former can increase the activity of β-amylase by either increasing free β-amylase or releasing binding β-amylaseisoenzyme. β-amylaseisoenzyme inhibitors can significantly inhibit β-amylase activity, nevertheless α-amylase activators and inhibitors have no significant effect on β-amylaseisoenzyme, which further proved that the β-amylase exerted the effects in the early period of wheat seed more precisely during the imbibition of the seeds.
Temporal association of sNfL and gad‐enhancing lesions in multiple sclerosis
Authors: Rosso Mattia , Gonzalez Cindy T. , Healy Brian C. , Saxena Shrishti , Paul Anu , Bjornevik Kjetil , Kuhle Jens , Benkert Pascal , Leppert David , Guttmann Charles , Bakshi Rohit , Weiner Howard L. , Chitnis Tanuja
Published: May 2020

Objective

Multiple sclerosis (MS) is an autoimmune demyelinating disorder, which is characterized by relapses and remissions. Serum neurofilament light chain (sNfL) is an emerging biomarker of disease activity but its clinical use is still limited. In this study, we aim to characterize the temporal association between sNfL and new clinical relapses and new gadolinium‐enhancing (Gd+) lesions.

Methods

Annual sNfL levels were measured with a single‐molecule array (SIMOA) assay in 94 patients with MS enrolled in the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women’s Hospital (CLIMB) study. We used a multivariable linear mixed‐effects model to test the temporal association of sNfL with clinical relapses and/or new Gd+ lesions. We adjusted this model for age, disease duration, sex, and disease‐modifying therapies (DMTs) use.

Results

In the 3 months after a Gd+ lesion, we observed an average 35% elevation in sNfL (P < 0.0001) compared to remission samples. We also observed an average 32.3% elevation in sNfL at the time of or prior to a Gd+ lesion (P = 0.002) compared to remission. We observed a significant elevation in sNfL after a clinical relapse only when associated with a Gd+ lesion.

Interpretation

Our findings support sNfL as a marker of clinical relapses and Gd+ lesions. sNfL peaks in a 3‐month window around Gd+ lesions. sNfL shows promise as a biomarker of neurological inflammation and possibly of simultaneous Gd+ lesions during a clinical relapse.
Artificial Biosystem for Modulation of Interactions between Antigen‐Presenting Cells and T Cells
Authors: Alatoom Aseel , Sapudom Jiranuwat , Soni Priya , Mohamed Walaa Kamal E. , Garcia‐Sabaté Anna , Teo Jeremy
Published: May 2020

T cell activation is triggered by signal molecules on the surface of antigen‐presenting cells (APC) and subsequent exertion of cellular forces. Deciphering the biomechanical and biochemical signals in this complex process is of interest and will contribute to an improvement in immunotherapy strategies. To address underlying questions, coculture and biomimetic models are established. Mature dendritic cells (mDC) are first treated with cytochalasin B (CytoB), a cytoskeletal disruption agent known to lower apparent cellular stiffness and reduction in T cell proliferation is observed. It is attempted to mimic mDC and T cell interactions using polyacrylamide (PA) gels with defined stiffness corresponding to mDC (0.2–25 kPa). Different ratios of anti‐CD3 (aCD3) and anti‐CD28 (aCD28) antibodies are immobilized onto PA gels. The results show T cell proliferation is triggered by both aCD3 and aCD28 in a stiffness‐dependent manner. Cells cultured on aCD3 immobilized on gels has significantly enhanced proliferation and IL‐2 secretion, compared to aCD28. Furthermore, ZAP70 phosphorylation is enhanced in stiffer substrate a in a aCD3‐dependent manner. The biosystem provides an approach to study the reduction of T cell proliferation observed on CytoB‐treated mDC. Overall, the biosystem allows distinguishing the impact of biophysical and biochemical signals of APC and T cell interactions in vitro.
Engineering Co2MnAlxSi1−x Heusler Compounds as a Model System to Correlate Spin Polarization, Intrinsic Gilbert Damping, and Ultrafast Demagnetization
Authors: Guillemard Charles , Zhang Wei , Malinowski Gregory , de Melo Claudia , Gorchon Jon , Petit‐Watelot Sebastien , Ghanbaja Jaafar , Mangin Stéphane , Le Fèvre Patrick , Bertran Francois , Andrieu Stéphane
Published: May 2020

Engineering of magnetic materials for developing better spintronic applications relies on the control of two key parameters: the spin polarization and the Gilbert damping, responsible for the spin angular momentum dissipation. Both of them are expected to affect the ultrafast magnetization dynamics occurring on the femtosecond timescale. Here, engineered Co2MnAlxSi1‐x Heusler compounds are used to adjust the degree of spin polarization at the Fermi energy, P, from 60% to 100% and to investigate how they correlate with the damping. It is experimentally demonstrated that the damping decreases when increasing the spin polarization from 1.1 × 10−3 for Co2MnAl with 63% spin polarization to an ultralow value of 4.6 × 10−4 for the half‐metallic ferromagnet Co2MnSi. This allows the investigation of the relation between these two parameters and the ultrafast demagnetization time characterizing the loss of magnetization occurring after femtosecond laser pulse excitation. The demagnetization time is observed to be inversely proportional to 1 – P and, as a consequence, to the magnetic damping, which can be attributed to the similarity of the spin angular momentum dissipation processes responsible for these two effects. Altogether, the high‐quality Heusler compounds allow control over the band structure and therefore the channel for spin angular momentum dissipation.
Extrusion and Microfluidic‐Based Bioprinting to Fabricate Biomimetic Tissues and Organs
Authors: Davoodi Elham , Sarikhani Einollah , Montazerian Hossein , Ahadian Samad , Costantini Marco , Swieszkowski Wojciech , Willerth Stephanie Michelle , Walus Konrad , Mofidfar Mohammad , Toyserkani Ehsan , Khademhosseini Ali , Ashammakhi Nureddin
Published: May 2020

Next generation engineered tissue constructs with complex and ordered architectures aim to better mimic the native tissue structures, largely due to advances in 3D bioprinting techniques. Extrusion bioprinting has drawn tremendous attention due to its widespread availability, cost‐effectiveness, simplicity, and its facile and rapid processing. However, poor printing resolution and low speed have limited its fidelity and clinical implementation. To circumvent the downsides associated with extrusion printing, microfluidic technologies are increasingly being implemented in 3D bioprinting for engineering living constructs. These technologies enable biofabrication of heterogeneous biomimetic structures made of different types of cells, biomaterials, and biomolecules. Microfluiding bioprinting technology enables highly controlled fabrication of 3D constructs in high resolutions and it has been shown to be useful for building tubular structures and vascularized constructs, which may promote the survival and integration of implanted engineered tissues. Although this field is currently in its early development and the number of bioprinted implants is limited, it is envisioned that it will have a major impact on the production of customized clinical‐grade tissue constructs. Further studies are, however, needed to fully demonstrate the effectiveness of the technology in the lab and its translation to the clinic.
Multichannel Effect of Triplet Excitons for Highly Efficient Green and Red Phosphorescent OLEDs
Authors: Tian Qi‐Sheng , Yuan Shuai , Shen Wan‐Shan , Zhang Yuan‐Lan , Wang Xue‐Qi , Kong Fan‐Cheng , Liao Liang‐Sheng
Published: May 2020

With the inherent organic–metal system property, phosphorescent organic light‐emitting diodes (PhOLEDs) are capable of exhibiting high performance. However, the existence of unintended triplet–triplet annihilation (TTA), which is mainly originated from high triplet exciton density leading to inferior device performance, is a current predicament. For mitigating the TTA in devices, reported herein is an effective host system with the role of precisely controlling the triplet excitons via the multichannel processes, in which a bipolar host material, a hole‐transporting material, and an electron‐transporting material are mixed to manage the triplet exciton transfer. The mixed‐host with so‐called “triplet excitons harvesting” strategy exhibits two concomitant reverse intersystem crossing (RISC) processes that simultaneously occur in the bipolar host material:electron‐transporting material and the host‐transporting material:electron‐transporting material exciplexes, respectively. Highly efficient green and red PhOLEDs are demonstrated by these multichannel processes, in which phosphorescent emitters bis(2‐phenylpyridine) (acetylacetonate) iridium(III) (Ir(ppy)2(acac)) and bis(2‐methyldibenzo[f,h]‐quinoxaline) (acetylacetonate) iridium(III) (Ir(MDQ)2(acac)) are doped into the mixed‐host, respectively. The green and red PhOLEDs realize nearly 30% of maximum external quantum efficiencies of 29.4% and 29.2%, respectively, and also maintain 29.1% and 28.3% at 1000 cd m−2. These excellent efficiencies and low roll‐offs confirm that the concomitant RISC processes effectively manage and utilize triplet excitons.
Synthesis of Bulky 1,1‐Diarylalkanes by Copper‐Catalyzed 1,2‐Alkylarylation of Styrenes with α‐Carbonyl Alkyl Bromides and Arenes involving C−H Functionalization
Authors: Luo Shu‐Zheng , Min Man‐Yi , Wu Yan‐Chen , Jiang Shuai‐Shuai , Xiao Yu‐Ting , Song Ren‐Jie , Li Jin‐Heng
Published: May 2020

A copper and silver‐promoted intermolecular 1,2‐alkylarylation of styrenes with α‐carbonyl alkyl bromides and arenes for producing highly bulky 1,1‐diarylalkane derivatives has been developed. In this transformations, two new C−C bonds were formed in a single reaction step through C−Br bond cleavage and C(sp2)−H functionalization. This protocol tolerates a variety of α‐carbonyl alkyl bromides, including primary, secondary and tertiary α‐bromoalkyl ketone esters.

magnified image
The Manipulation of RNA‐Guided Nucleic Acid Cleavage with Ninhydrin Chemistry
Authors: Wang Shao‐Ru , Huang Hai‐Yan , Liu Jian , Wei Lai , Wu Ling‐Yu , Xiong Wei , Yin Ping , Tian Tian , Zhou Xiang
Published: May 2020

CRISPR (clustered regularly interspaced short palindromic repeats) systems have been established as valuable genome‐editing tools. Controlling CRISPR systems has high biological significance and this field has garnered intense interest. There is a considerable need for simple approaches with no need for protein engineering. The CRISPR systems usually require a guide RNA (gRNA) moiety to recruit and direct the nuclease complexes. In this respect, the ninhydrin (1,2,3‐indantrione monohydrate) seems to have considerable potential, as yet unexploited, for modifying gRNA. In this study, ninhydrin chemistry is explored for reversible postsynthetic modification of gRNA molecules. It is further shown that ninhydrin chemistry is efficient in modulating two important CRISPR systems. Thus, ninhydrin chemistry exhibits potential applications in future chemical biology studies.
Device and Circuit Architectures for In‐Memory Computing
Authors: Ielmini Daniele , Pedretti Giacomo
Published: May 2020

With the rise in artificial intelligence (AI), computing systems are facing new challenges related to the large amount of data and the increasing burden of communication between the memory and the processing unit. In‐memory computing (IMC) appears as a promising approach to suppress the memory bottleneck and enable higher parallelism of data processing, thanks to the memory array architecture. As a result, IMC shows a better throughput and lower energy consumption with respect to the conventional digital approach, not only for typical AI tasks, but also for general‐purpose problems such as constraint satisfaction problems (CSPs) and linear algebra. Herein, an overview of IMC is provided in terms of memory devices and circuit architectures. First, the memory device technologies adopted for IMC are summarized, focusing on both charge‐based memories and emerging devices relying on electrically induced material modification at the chemical or physical level. Then, the computational memory programming and the corresponding device nonidealities are described with reference to offline and online training of IMC circuits. Finally, array architectures for computing are reviewed, including typical architectures for neural network accelerators, content addressable memory (CAM), and novel circuit topologies for general‐purpose computing with low complexity.
Evolutionary Algorithm‐Guided Voxel‐Encoding Printing of Functional Hard‐Magnetic Soft Active Materials
Authors: Wu Shuai , Hamel Craig M. , Ze Qiji , Yang Fengyuan , Qi H. Jerry , Zhao Ruike
Published: May 2020

Hard‐magnetic soft active materials (hmSAMs), embedding hard‐magnetic particles in soft polymeric matrices, have attracted a great number of research interests due to their fast‐transforming, untethered control, as well as excellent programmability. However, the current direct‐ink‐write (DIW) printing‐based fabrication of hmSAM parts and structures only permits programmable magnetic direction with a constant magnetic density. Also, the existing designs rely on the brute‐force approach to generate the assignment of magnetization direction distribution, which can only produce intuitional deformations. These two factors greatly limit the design space and the application potentials of hmSAMs. Herein, a “voxel‐encoding DIW printing” method to program both the magnetic density and direction distributions during hmSAM printing is introduced. The voxel‐encoding DIW printing is then integrated with an evolutionary algorithm (EA)‐based design strategy to achieve the desired magnetic actuation and motion with complex geometry variations and curvature distributions. With the new EA‐guided voxel‐encoding DIW printing technique, the functional hmSAMs that produce complicated shape morphing with desired curvature distributions for advanced applications such as biomimetic motions are demonstrated. These demonstrations indicate that the proposed EA‐guided voxel‐encoding DIW printing method significantly broadens the application potentials of hmSAMs.
Community Organizing and Transformative Change in the Response to Domestic Violence in India
Authors: Menon Suvarna V. , Allen Nicole E.
Published: May 2020

Pervasive cultural narratives that normalize domestic violence have made efforts to respond to domestic violence in India challenging. An effective response to domestic violence in India needs to be transformative in nature, supporting the empowerment of survivors of violence and empowering communities to support survivors. Various studies have highlighted the importance of settings like grassroots organizations for promoting empowerment of members through community organizing. This qualitative study builds on this growing body of research using a grassroots agency in India as an exemplar to understand (a) empowering processes at the individual and community level associated with the agency’s community organizing efforts; and (b) salient mechanisms associated with social change and action in the response to domestic violence in the community. At the individual level, the agency’s organizing efforts provided knowledge, skills and resources, and opportunities for participation and leadership. At the community level, the agency engages in capacity building and increases social capital of members. The mechanisms that emerged as salient were increased critical consciousness of members, an emphasis on breaking the silence around domestic violence, community trust and cohesion, and capacity for informal social control. Implications of our findings for intervention and prevention work are discussed.

Highlights

Community organizing is an important avenue for change in the response to domestic violence.

Community organizing can facilitate empowering processes like participation and leadership.

Building capacity and social capital is central to facilitating empowerment of communities.
Outcomes of recurrent nasopharyngeal carcinoma patients treated with endoscopic nasopharyngectomy: a meta‐analysis
Authors: Yang Jingyi , Song Xiaole , Sun Xicai , Liu Quan , Hu Li , Yu Hongmeng , Wang Dehui
Published: May 2020

Background

Recurrent nasopharyngeal carcinoma (rNPC) is mainly managed with re‐irradiation or salvage surgery. Endoscopic resection is generally considered as the preferred surgical treatment, whereas a standard treatment modality has yet to be established. This article is aimed to summarize the treatment outcomes of endoscopic rNPC resection.

Methods

Major medical databases including PubMed, EMBASE, Cochrane Central Library, Web of Science, and 2 major Chinese databases, CNKI and Wanfang, were searched for studies on endoscopic rNPC resection. Main characteristics of study and outcomes of interest were retrieved from articles meeting the selection criteria for meta‐analysis.

Results

A total of 761 articles were identified through the initial systematic research. The combined 1‐year, 2‐year, and 5‐year overall survival (OS) rates were 97%, 92%, and 73% with random effect model, respectively. The combined 2‐year and 5‐year disease‐free survival (DFS) rates were 81% and 62%, respectively. Meta‐regression analysis showed that high recurrent tumor (rT) stage (rT3 to rT4) case proportion was a correlative factor of heterogeneity. Combined 2‐year OS rate in rT1, rT2, rT3, and rT4 patients were 100%, 87%, 78%, and 38%, respectively. Combined 2‐year DFS rate in rT1 and rT2 patients were and 96% and 86%, respectively.

Conclusion

The combined OS and DFS rates of rNPC patients treated with endoscopic nasopharyngectomy were summarized and reported in our study. This meta‐analysis indicated that endoscopic nasopharyngectomy has comparable and possibly better treatment outcomes than intensity‐modulated radiotherapy (IMRT). Therefore, the result of our study indicated that randomized controlled trials (RCTs) are needed in rNPC patients to compare treatment outcomes of endoscopic nasopharyngectomy vs IMRT.
Molecular Spring‐like Triple‐Helix Coordination Polymers as Dual‐Stress and Thermally Responsive Crystalline Metal–Organic Materials
Authors: Mei Lei , An Shu‐wen , Hu Kong‐qiu , Wang Lin , Yu Ji‐pan , Huang Zhi‐wei , Kong Xiang‐he , Xia Chuan‐qin , Chai Zhi‐fang , Shi Wei‐qun
Published: May 2020

Elastic metal–organic materials (MOMs) capable of multiple stimuli‐responsiveness based on dual‐stress and thermally responsive triple‐helix coordination polymers are presented. The strong metal‐coordination linkage and the flexibility of organic linkers in these MOMs, rather than the 4 Å stacking interactions observed in organic crystals, causes the helical chain to act like a molecular spring and thus accounts for their macroscopic elasticity. The thermosalient effect of elastic MOMs is reported for the first time. Crystal structure analyses at different temperatures reveal that this thermoresponsiveness is achieved by adaptive regulation of the triple‐helix chains by fine‐tuning the opening angle of flexible V‐shaped organic linkers and rotation of its lateral conjugated groups to resist possible expansion, thus demonstrating the vital role of adaptive reorganization of triple‐helix metal–organic chains as a molecular spring‐like motif in crystal jumping.
Revisiting the Polymerization of Diphenylacetylenes with Tungsten(VI) Chloride and Tetraphenyltin: An Alternative Mechanism by a Metathesis Catalytic System
Authors: Miyairi Mami , Taniguchi Tsuyoshi , Nishimura Tatsuya , Maeda Katsuhiro
Published: May 2020

An alternative reaction mechanism of the polymerization of diphenylacetylelnes using a catalytic system composed of tungsten(VI) chloride and tetraphenyltin has been proposed through the optimization of reaction conditions and investigation of the effect of the electronic nature of diphenylacetylene monomers on the polymerizability. The detailed structures of the polymers have been suggested by mass spectrometric analysis of the obtained polymers and oligomers, which suggested that a phenyl group of tetraphenyltin has been introduced to an initiating end of the polymer chain. Mass spectrometric analysis also provided information about the termination processes of the polymerization. The experimental results strongly suggested that the polymerization of diphenylacetylenes using tungsten(VI) chloride and tetraphenyltin proceeds through a migratory insertion mechanism rather than the long‐accepted metathesis mechanism.
Silica‐Grafted Tris(neopentyl)aluminum: A Monomeric Aluminum Solid Co‐catalyst for Efficient Nickel‐Catalyzed Ethene Dimerization
Authors: Moroz Ilia B. , Florian Pierre , Viger‐Gravel Jasmine , Gordon Christopher P. , Lesage Anne , Copéret Christophe
Published: May 2020

A silica‐supported monomeric alkylaluminum co‐catalyst was prepared via surface organometallic chemistry by contacting tris(neopentyl)aluminum and partially dehydroxylated silica. This system, fully characterized by solid‐state 27Al NMR spectroscopy augmented by computational studies, efficiently activates (nBu3P)2NiCl2 towards dimerization of ethene, demonstrating comparable activity to previously reported dimeric diethylaluminum chloride supported on silica. Three types of aluminum surface species have been identified: monografted tetracoordinated Al species as well as two types of bisgrafted Al species—tetra‐ and pentacoordinated. Of them, only the monografted Al species is proposed to be able to activate the (nBu3P)2NiCl2 complex and generate the active cationic species.
Partially Pyrolyzed Binary Metal–Organic Framework Nanosheets for Efficient Electrochemical Hydrogen Peroxide Synthesis
Authors: Wang Mengjun , Zhang Nan , Feng Yonggang , Hu Zhiwei , Shao Qi , Huang Xiaoqing
Published: May 2020

Herein, we developed a partially controlled pyrolysis strategy to create evenly distributed NiO nanoparticles within NiFe‐MOF nanosheets (MOF NSs) for electrochemical synthesis of H2O2 by a two‐electron oxygen reduction reaction (ORR). The elemental Ni can be partially transformed to NiO and uniformly distributed on the surface of the MOF NSs, which is crucial for the formation of the particular structure. The optimized MOF NSs‐300 exhibits the highest activity for ORR with near‐zero overpotential and excellent H2O2 selectivity (ca. 99 %) in 0.1 m KOH solution. A high‐yield H2O2 production rate of 6.5 mol gcat−1 h−1 has also been achieved by MOF NSs‐300 in 0.1 m KOH and at 0.6 V (vs. RHE). In contrast to completely pyrolyzed products, the enhanced catalytic activities of partially pyrolyzed MOF NSs‐300 originates mainly from the retained MOF structure and the newly generated NiO nanoparticles, forming the coordinatively unsaturated Ni atoms and tuning the performance towards electrochemical H2O2 synthesis.
Nickel‐Mediated Trifluoromethylation of Phenol Derivatives by Aryl C−O Bond Activation
Authors: Hu Wei‐Qiang , Pan Shen , Xu Xiu‐Hua , Vicic David A. , Qing Feng‐Ling
Published: May 2020

The increasing pharmaceutical importance of trifluoromethylarenes has stimulated the development of more efficient trifluoromethylation reactions. Tremendous efforts have focused on copper‐ and palladium‐mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel‐mediated trifluoromethylation of phenol derivatives with readily available trimethyl(trifluoromethyl)silane (TMSCF3). The strategy relies on PMe3‐promoted oxidative addition and transmetalation, and CCl3CN‐induced reductive elimination. The broad utility of this transformation has been demonstrated through the direct incorporation of trifluoromethyl into aromatic and heteroaromatic systems, including biorelevant compounds.
Overriding Intrinsic Reactivity in Aliphatic C−H Oxidation: Preferential C3/C4 Oxidation of Aliphatic Ammonium Substrates
Authors: Knezevic Melina , Heilmann Michael , Piccini Giovanni Maria , Tiefenbacher Konrad
Published: May 2020

The site‐selective C−H oxidation of unactivated positions in aliphatic ammonium chains poses a tremendous synthetic challenge, for which a solution has not yet been found. Here, we report the preferential oxidation of the strongly deactivated C3/C4 positions of aliphatic ammonium substrates by employing a novel supramolecular catalyst. This chimeric catalyst was synthesized by linking the well‐explored catalytic moiety Fe(pdp) to an alkyl ammonium binding molecular tweezer. The results highlight the vast potential of overriding the intrinsic reactivity in chemical reactions by guiding catalysis using supramolecular host structures that enable a precise orientation of the substrates.
What's Hot, What's Not: The Trends of the Past 20 Years in the Chemistry of Odorants
Authors: Armanino Nicolas , Charpentier Julie , Flachsmann Felix , Goeke Andreas , Liniger Marc , Kraft Philip
Published: May 2020

This review is the sequel to the 2000 report on the recent advances in the chemistry of odorants and it summarizes the developments in fragrance chemistry over the past 20 years. Following the olfactory spectrum set out in that report, trendsetting so‐called captive odorants (patent‐protected ingredients unavailable to the market) are presented according to the main odor families: “fruity”, “marine”, “green”, “floral”, “spicy”, “woody”, “amber”, and “musky”. The design of odorants, their chemical synthesis, and their use in modern perfumery are illustrated with prominent examples. Featured are new fruity odorants that provide signature in the top note, as well as precursor technology. In the green domain, focus is on leafy notes and green pear. New benzodioxepines and benzodioxoles have modernized the marine family and required a revision of the existing olfactophore models. The replacement of Lilial and Lyral kept the industry busy in the floral domain with a plethora of new “muguets”. There was continued activity in the domain of rose odorants, especially in the area of rose ketones. Biotechnology became significant, for example, with Clearwood and Ambrofix, and the principal odorants of vetiver oil in the woody family have been found. Fourth and fifth families of musk odorants were also discovered and populated. Thus, new avenues for further explorations into fragrance chemistry have been opened.
Three‐dimensional digital image construction of metaxylem vessels in root tips of Zea mays subsp. mexicana from thin transverse sections
Authors: Miki Yasushi , Saito Susumu , Niki Teruo , Gladish Daniel K.
Published: May 2020

Premise

Young plant roots share a common architecture: a central vascular cylinder surrounded by enveloping cylinders of ground and dermal tissue produced by an apical promeristem. Roots with closed apical organization can be studied to explore how ontogeny is managed. The analysis of transverse and longitudinal sections has been the most useful approach for this, but suffers from limitations. We developed a new method that utilizes digital photography of transverse sections and three‐dimensional (3D) computer virtual reconstructions to overcome the limitations of other techniques.

Methods

Serial transverse sections of teosinte root tips (Zea mays subsp. mexicana) were used to construct longitudinal images, 3D images, and an animated 3D model. The high‐resolution, high‐contrast, and low‐distortion sectioning method developed previously by the authors enabled high‐quality virtual image construction with the aid of a standard laptop computer.

Results

The resulting 3D images allowed greater insight into root tissue ontogeny and organization, especially specific cellular structures such as histogen layers, xylem vessels, pericycle, and meristematic initials.

Discussion

This new method has advantages over confocal laser scanning microscopy and magnetic resonance imaging for visualizing anatomy, and includes a procedure to correct for sectioning distortion. An additional advantage of this method, developed to produce better knowledge about the developmental anatomy of procambium in roots, is its applicability to a wide range of anatomical subjects.