bluuebunny/crossref_metadata_2025_split huggingface dataset:
PDL1 blockage increases fetal resorption and Tfr cells but does not affect Tfh/Tfr ratio and B-cell maturation during allogeneic pregnancy
Authors: Zeng Weihong , Qin Shi , Wang Renjie , Zhang Yuchen , Ma Xiaoling , Tian Fuju , Liu Xiao-Rui , Qin Xiaoli , Liao Shujie , Sun Liqun , Lin Yi 
Published: February 2020

AbstractA successful pregnancy requires sophisticated regulation of uterine microenvironment to guarantee the existence of semi-allogeneic conceptus without immune rejection. T follicular regulatory (Tfr) cells exert a suppressive effect on Tfh-cell expansion, B-cell response, and antibody production. Although accumulating evidence has demonstrated that dysregulations of Tfr cells can bring on various immunological diseases, their immunomodulatory roles during pregnancy still remain unheeded. Herein, we introduced an allogeneic normal-pregnant mouse model and found that CD4+CXCR5hiPD-1hiFoxp3+ Tfr cells were preferentially accumulated in the uterus at mid-gestation and displayed a distinct phenotype. In addition, the absence of PDL1 resulted in increased fetal resorption by favoring Tfr cells accumulation and upregulating PD-1 expression on these cells. However, PDL1 blockade affected neither the ratio of Tfh/Tfr cells nor the maturation and differentiation of B cells. Overall, our results are the first to present a correlation of Tfr cells accumulation with healthy allogeneic pregnancy and PDL1 blockade-induced miscarriage, and to indicate that appropriate assembly of Tfr cells is important for pregnancy maintenance. Since blockade of PD-1-PDL1 pathway leads to more Tfr cells and fetal losses, the reproductive safety must be taken into consideration when PD-1/PD-L1 checkpoint blockade immunotherapy is used in pregnancy.
Mammalian ALKBH1 serves as an N6-mA demethylase of unpairing DNA
Authors: Zhang Min , Yang Shumin , Nelakanti Raman , Zhao Wentao , Liu Gaochao , Li Zheng , Liu Xiaohui , Wu Tao , Xiao Andrew , Li Haitao 
Published: February 2020

AbstractN6-methyladenine (N6-mA) of DNA is an emerging epigenetic mark in mammalian genome. Levels of N6-mA undergo drastic fluctuation during early embryogenesis, indicative of active regulation. Here we show that the 2-oxoglutarate-dependent oxygenase ALKBH1 functions as a nuclear eraser of N6-mA in unpairing regions (e.g., SIDD, Stress-Induced DNA Double Helix Destabilization regions) of mammalian genomes. Enzymatic profiling studies revealed that ALKBH1 prefers bubbled or bulged DNAs as substrate, instead of single-stranded (ss-) or double-stranded (ds-) DNAs. Structural studies of ALKBH1 revealed an unexpected “stretch-out” conformation of its “Flip1” motif, a conserved element that usually bends over catalytic center to facilitate substrate base flipping in other DNA demethylases. Thus, lack of a bending “Flip1” explains the observed preference of ALKBH1 for unpairing substrates, in which the flipped N6-mA is primed for catalysis. Co-crystal structural studies of ALKBH1 bound to a 21-mer bulged DNA explained the need of both flanking duplexes and a flipped base for recognition and catalysis. Key elements (e.g., an ALKBH1-specific α1 helix) as well as residues contributing to structural integrity and catalytic activity were validated by structure-based mutagenesis studies. Furthermore, ssDNA-seq and DIP-seq analyses revealed significant co-occurrence of base unpairing regions with N6-mA in mouse genome. Collectively, our biochemical, structural and genomic studies suggest that ALKBH1 is an important DNA demethylase that regulates genome N6-mA turnover of unpairing regions associated with dynamic chromosome regulation.
Variant antigen diversity in Trypanosoma vivax is not driven by recombination
Authors: Silva Pereira Sara , de Almeida Castilho Neto Kayo J. G. , Duffy Craig W. , Richards Peter , Noyes Harry , Ogugo Moses , Rogério André Marcos , Bengaly Zakaria , Kemp Steve , Teixeira Marta M. G. , Machado Rosangela Z. , Jackson Andrew P. 
Published: February 2020

AbstractAfrican trypanosomes (Trypanosoma) are vector-borne haemoparasites that survive in the vertebrate bloodstream through antigenic variation of their Variant Surface Glycoprotein (VSG). Recombination, or rather segmented gene conversion, is fundamental in Trypanosoma brucei for both VSG gene switching and for generating antigenic diversity during infections. Trypanosoma vivax is a related, livestock pathogen whose VSG lack structures that facilitate gene conversion in T. brucei and mechanisms underlying its antigenic diversity are poorly understood. Here we show that species-wide VSG repertoire is broadly conserved across diverse T. vivax clinical strains and has limited antigenic repertoire. We use variant antigen profiling, coalescent approaches and experimental infections to show that recombination plays little role in diversifying T. vivax VSG sequences. These results have immediate consequences for both the current mechanistic model of antigenic variation in African trypanosomes and species differences in virulence and transmission, requiring reconsideration of the wider epidemiology of animal African trypanosomiasis.
Vapor–liquid–solid growth of large-area multilayer hexagonal boron nitride on dielectric substrates
Authors: Shi Zhiyuan , Wang Xiujun , Li Qingtian , Yang Peng , Lu Guangyuan , Jiang Ren , Wang Huishan , Zhang Chao , Cong Chunxiao , Liu Zhi , Wu Tianru , Wang Haomin , Yu Qingkai , Xie Xiaoming 
Published: February 2020

AbstractMultilayer hexagonal boron nitride (h-BN) is highly desirable as a dielectric substrate for the fabrication of two-dimensional (2D) electronic and optoelectronic devices. However, the controllable synthesis of multilayer h-BN in large areas is still limited in terms of crystallinity, thickness and stacking order. Here, we report a vapor–liquid–solid growth (VLSG) method to achieve uniform multilayer h-BN by using a molten Fe82B18 alloy and N2 as reactants. Liquid Fe82B18 not only supplies boron but also continuously dissociates nitrogen atoms from the N2 vapor to support direct h-BN growth on a sapphire substrate; therefore, the VLSG method delivers high-quality h-BN multilayers with a controllable thickness. Further investigation of the phase evolution of the Fe-B-N system reveals that isothermal segregation dominates the growth of the h-BN. The approach herein demonstrates the feasibility for large-area fabrication of van der Waals 2D materials and heterostructures.
The insect antimicrobial peptide cecropin A disrupts uropathogenic Escherichia coli biofilms
Authors: Kalsy Miriam , Tonk Miray , Hardt Martin , Dobrindt Ulrich , Zdybicka-Barabas Agnieszka , Cytrynska Malgorzata , Vilcinskas Andreas , Mukherjee Krishnendu 
Published: February 2020

AbstractCurrent antibiotics cannot eradicate uropathogenic Escherichia coli (UPEC) biofilms, leading to recurrent urinary tract infections. Here, we show that the insect antimicrobial peptide cecropin A (CecA) can destroy planktonic and sessile biofilm-forming UPEC cells, either alone or when combined with the antibiotic nalidixic acid (NAL), synergistically clearing infection in vivo without off-target cytotoxicity. The multi-target mechanism of action involves outer membrane permeabilization followed by biofilm disruption triggered by the inhibition of efflux pump activity and interactions with extracellular and intracellular nucleic acids. These diverse targets ensure that resistance to the CecA + NAL combination emerges slowly. The antimicrobial mechanisms of CecA, thus, extend beyond pore-forming activity to include an unanticipated biofilm-eradication process, offering an alternative approach to combat antibiotic-resistant UPEC infections.
Divergence across mitochondrial genomes of sympatric members of the Schistosoma indicum group and clues into the evolution of Schistosoma spindale
Authors: Jones Ben P. , Norman Billie F. , Borrett Hannah E. , Attwood Stephen W. , Mondal Mohammed M. H. , Walker Anthony J. , Webster Joanne P. , Rajapakse R. P. V. Jayanthe , Lawton Scott P. 
Published: February 2020

AbstractSchistosoma spindale and Schistosoma indicum are ruminant-infecting trematodes of the Schistosoma indicum group that are widespread across Southeast Asia. Though neglected, these parasites can cause major pathology and mortality to livestock leading to significant welfare and socio-economic issues, predominantly amongst poor subsistence farmers and their families. Here we used mitogenomic analysis to determine the relationships between these two sympatric species of schistosome and to characterise S. spindale diversity in order to identify possible cryptic speciation. The mitochondrial genomes of S. spindale and S. indicum were assembled and genetic analyses revealed high levels of diversity within the S. indicum group. Evidence of functional changes in mitochondrial genes indicated adaptation to environmental change associated with speciation events in S. spindale around 2.5 million years ago. We discuss our results in terms of their theoretical and applied implications.
Single subject and group whole-brain fMRI mapping of male genital sensation at 7 Tesla
Authors: Luijten Sven P. R. , Groenendijk Ilse M. , Holstege Joan C. , De Zeeuw Chris I. , van der Zwaag Wietske , Blok Bertil F. M. 
Published: February 2020

AbstractProcessing of genital sensations in the central nervous system of humans is still poorly understood. Current knowledge is mainly based on neuroimaging studies using electroencephalography (EEG), magneto-encephalography (MEG), and 1.5- or 3- Tesla (T) functional magnetic resonance imaging (fMRI), all of which suffer from limited spatial resolution and sensitivity, thereby relying on group analyses to reveal significant data. Here, we studied the impact of passive, yet non-arousing, tactile stimulation of the penile shaft using ultra-high field 7T fMRI. With this approach, penile stimulation evoked significant activations in distinct areas of the primary and secondary somatosensory cortices (S1 & S2), premotor cortex, insula, midcingulate gyrus, prefrontal cortex, thalamus and cerebellum, both at single subject and group level. Passive tactile stimulation of the feet, studied for control, also evoked significant activation in S1, S2, insula, thalamus and cerebellum, but predominantly, yet not exclusively, in areas that could be segregated from those associated with penile stimulation. Evaluation of the whole-brain activation patterns and connectivity analyses indicate that genital sensations following passive stimulation are, unlike those following feet stimulation, processed in both sensorimotor and affective regions.
Prospective Cohort study of Predictors of Follow-Up Diagnostic Colonoscopy from a Pragmatic Trial of FIT Screening
Authors: O’Connor Elizabeth A. , Nielson Carrie M. , Petrik Amanda F. , Green Beverly B. , Coronado Gloria D. 
Published: February 2020

AbstractThe goal of this study was to explore diagnostic colonoscopy completion in adults with abnormal screening fecal immunochemical test (FIT) results. This was a secondary analysis of the Strategies and Opportunities to Stop Colon Cancer in Priority Populations (Stop CRC) study, a cluster-randomized pragmatic trial to increase uptake of CRC screening in federally qualified community health clinics. Diagnostic colonoscopy completion and reasons for non-completion were ascertained through a manual review of electronic health records, and completion was compared across a wide range of individual patient health and sociodemographic characteristics. Among 2,018 adults with an abnormal FIT result, 1066 (52.8%) completed a follow-up colonoscopy within 12 months. Completion was generally similar across a wide range of participant subpopulations; however, completion was higher for participants who were younger, Hispanic, Spanish-speaking, and had zero or one of the Charlson medical comorbidities, compared to their counterparts. Neighborhood-level predictors were not associated with diagnostic colonoscopy completion. Thus, completion of a diagnostic colonoscopy was relatively low in a large sample of community health clinic adults who had an abnormal screening FIT result. While completion was generally similar across a wide range of characteristics, younger, healthier, Hispanic participants tended to have a higher likelihood of completion.
In-cell NMR as a sensitive tool to monitor physiological condition of Escherichia coli
Authors: Sugiki Toshihiko , Yamaguchi Yoshihiro , Fujiwara Toshimichi , Inouye Masayori , Ito Yutaka , Kojima Chojiro 
Published: February 2020

AbstractThe in-cell NMR technique offers significant insights into the structure and function of heterologous proteins in the physiological intracellular environment at an atomic resolution. Escherichia coli (E. coli) is one of the most widely used host cells for heterologous protein expression in structural biological studies as well as for in-cell NMR studies to investigate fundamental structural characteristics and the physiochemistry of certain proteins and their intermolecular interactions under physiological conditions. However, in many cases, it is not easy to obtain well-resolved in-cell NMR spectra because the detectability and resolution of these spectra are significantly influenced by intracellular factors such as nonspecific intermolecular interactions. In this study, we re-examined the experimental parameters of E. coli in-cell NMR and found that the detectability and resolution of the NMR spectra clearly depended on the growth phase of the host cells. Furthermore, the detectability and resolution of the E. coli in-cell NMR spectra correlated with the soluble fraction amounts of the expressed target protein. These results indicate that the E. coli in-cell NMR spectrum of a target protein is a useful tool for monitoring the intracellular conditions of the host cell and for establishing the appropriate cultivation conditions for protein overexpression.
The draft genome of mandrill (Mandrillus sphinx): An Old World monkey
Authors: Yin Ye , Yang Ting , Liu Huan , Huang Ziheng , Zhang Yaolei , Song Yue , Wang Wenliang , Guang Xuanmin , Sahu Sunil Kumar , Kristiansen Karsten 
Published: February 2020

AbstractMandrill (Mandrillus sphinx) is a primate species, which belongs to the Old World monkey (Cercopithecidae) family. It is closely related to human, serving as a model for human health related research. However, the genetic studies on and genomic resources of mandrill are limited, especially in comparison to other primate species. Here we produced 284 Gb data, providing 96-fold coverage (considering the estimated genome size of 2.9 Gb), to construct a reference genome for the mandrill. The assembled draft genome was 2.79 Gb with contig N50 of 20.48 Kb and scaffold N50 of 3.56 Mb. We annotated the mandrill genome to find 43.83% repeat elements, as well as 21,906 protein-coding genes. The draft genome was of good quality with 98% gene annotation coverage by Benchmarking Universal Single-Copy Orthologs (BUSCO). Based on comparative genomic analyses of the Major Histocompatibility Complex (MHC) of the immune system in mandrill and human, we found that 17 genes in the mandrill that have been associated with disease phenotypes in human such as Lung cancer, cranial volume and asthma, barbored amino acids changing mutations. Gene family analyses revealed expansion of several genes, and several genes associated with stress environmental adaptation and innate immunity responses exhibited signatures of positive selection. In summary, we established the first draft genome of the mandrill of value for studies on evolution and human health.
NanoThermoMechanical AND and OR Logic Gates
Authors: Hamed Ahmed , Ndao Sidy 
Published: February 2020

AbstractToday’s electronics cannot perform in harsh environments (e.g., elevated temperatures and ionizing radiation environments) found in many engineering applications. Based on the coupling between near-field thermal radiation and MEMS thermal actuation, we presented the design and modeling of NanoThermoMechanical AND, OR, and NOT logic gates as an alternative, and showed their ability to be combined into a full thermal adder to perform complex operations. In this work, we introduce the fabrication and characterization of the first ever documented Thermal AND and OR logic gates. The results show thermal logic operations can be achieved successfully through demonstrated and easy-to-manufacture NanoThermoMechanical logic gates.
Investigating the influence of perinatal nicotine exposure on genetic profiles of neurons in the sub-regions of the VTA
Authors: Kazemi Tina , Avci Naze G. , Keller Renee F. , Akay Yasemin M. , Akay Metin 
Published: February 2020

AbstractChronic nicotine exposure during pregnancy has been shown to induce physiological and anatomical alterations in offspring. Previously, we investigated the complexity of dopamine (DA) neuron firing in the sub-regions of the ventral tegmental area (VTA) following perinatal nicotine exposure. Using approximate entropy, we found that within the middle sub-region, the parainterfascicular nucleus (PIF), there was higher complexity indicating more random neural firing and a less homogeneous neuron population. Therefore, we sought to investigate the neuron populations within the sub-regions of the VTA following perinatal nicotine exposure. We used real time PCR in order to find the relative quantity of glutamate to γ-aminobutyric acid (GABA), DA, and glutamate neurons within three sub-regions: the parabrachial pigmented nucleus (PBP), parainterfascicular nucleus (PIF), and paranigral nucleus (PN). Our results showed that the PIF region of the VTA contained a more diverse population of neurons resulting in a more complex system. In addition, we found that DA neurons are more activated in PN sub-region of the VTA, which mediates the rewarding effects of drugs including nicotine. Lastly, using immunohistochemistry, we observed an overall decrease in DA neurons following perinatal nicotine exposure.
Predictors of impending acute chest syndrome in patients with sickle cell anaemia
Authors: Alkindi Salam , Al-Busaidi Ikhlas , Al-Salami Bushra , Raniga Samir , Pathare Anil , Ballas Samir K. 
Published: February 2020

AbstractAcute chest syndrome (ACS) is a major complication of sickle cell anaemia (SCA) and a leading cause for hospital admissions and death. We aimed to study the spectrum of clinical and laboratory features of ACS and to assess the predisposing factors and predictors of severity. A retrospective case-control cohort was studied by retrieving patient information from electronic medical records after ethical approval. One hundred adolescents and adults with SCA and hospital admissions for ACS were identified through the discharge summaries, along with 20 additional patients presenting with VOC, but without ACS (controls). Among the patients with ACS, fever (>38.5 °C), reduced oxygen saturation (<95) and asplenia significantly differed when compared to those of controls (p < 0.05, chi-squared test). The degree of severity was reflected in the use of non-invasive ventilation (NIV), simple and exchange transfusions, and the presence of bilateral pleural effusions and multi-lobar atelectasis/consolidation, which were significantly higher in the cases with ACS than in the controls. Lower haemoglobin (Hb) and high WBC counts were also significantly different between the two groups (p < 0.05, Student’s t test). Using logistic regression, our study further demonstrated that asplenia, fever, and reduced O2 saturation, along with low Hb and leukocytosis, were important predictors for the development of ACS.
All-Optical Naked-Eye Ghost Imaging
Authors: Wang Gao , Zheng Huaibin , Tang Zhiguo , Zhou Yu , Chen Hui , Liu Jianbin , He Yuchen , Yuan Yuan , Li Fuli , Xu Zhuo 
Published: February 2020

AbstractGhost imaging is usually based on the optoelectronic process and electronic computing. A new ghost imaging approach is put forward in the paper that avoids any optoelectronic or electronic process. Instead, the proposed scheme exploits all-optical correlation and the vision persistence effect to generate images observed by naked eyes. To realize high contrast naked-eye ghost imaging, a special pattern-scanning architecture on a low-speed light-modulation disk is designed, which also enables high-resolution imaging with lower-order Hadamard vectors and boosts the imaging speed. With this approach, we realize high-contrast real-time naked-eye ghost imaging for moving colored objects.
Magnetic Needle Steering in Soft Phantom Tissue
Authors: Ilami Mahdi , Ahmed Reza James , Petras Alex , Beigzadeh Borhan , Marvi Hamid 
Published: February 2020

AbstractNeedle steering is a technology for guiding needles around sensitive internal obstacles in minimally invasive surgery. Traditional techniques apply rotation at the base of a needle with an asymmetric tip, enabling steering through the redirection of radial forces. Magnetic steering of catheters and continuum manipulators is another technology that allows steering of a shaft in the body. Both of these techniques rely on mechanical or manual shaft advancement methods. Needle steering has not achieved widespread clinical use due to several limitations: 1- buckling and compression effects in the shaft and needle rotation cause excessive tissue damage; 2- torsion effects on the shaft and needle deflection at tissue boundaries lead to difficulty in control; and 3- restricted radius of curvature results in limited workspace. Magnetically steered catheters and continuum manipulators also suffer from limited curvature and the possibility of buckling. This paper proposes a novel needle steering method empowered by electromagnetic actuation that overcomes all of the aforementioned limitations, making it a promising option for further study toward healthcare applications.
Imaging and Pathological Features of Idiopathic Portal Hypertension and Differential Diagnosis from Liver Cirrhosis
Authors: Zhao Zhen-Long , Wei Ying , Wang Tai-Ling , Peng Li-Li , Li Yan , Yu Ming-An 
Published: February 2020

AbstractIdiopathic portal hypertension (IPH) mimics liver cirrhosis in many aspects, and no efficient imaging method to differentiate the two diseases has been reported to date. In this study, the imaging and pathological characteristics were analysed for both IPH and cirrhosis. From January 2015 to March 2019, ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) images and pathological results from 16 IPH and 16 liver cirrhosis patients, as well as imaging results of 16 normal patients as a control group, were retrospectively reviewed. The age of the patients was 39 ± 20 years. There was a significant difference in the mean lumen diameter, wall thickness and ratio of thickness to diameter between the IPH and liver cirrhosis patients in the main and sagittal portal veins (P < 0.05), as well as in the lumen diameter and ratio of thickness to diameter between the IPH and liver cirrhosis patients in the Segment 3 (S3) portal vein (P < 0.05). In IPH patients, the main imaging changes were portal vein wall thickening, stenosis or occlusion, a low enhancement area along the portal vein in the delay phase in contrast-enhanced imaging, and a non-homogeneous change in T1WI. The corresponding pathological changes included interlobular vein thickening, stenosis, occlusion, portal area fibrosis, and atrophy or apoptosis of hepatocytes. The main imaging characteristic of liver cirrhosis was a nodular change in T1WI, and the related pathological change was pseudolobule formation. The imaging characteristics of IPH include thickening of the portal vein vascular wall, stenosis of the portal vein lumen and the absence of diffuse cirrhosis-like nodules. These imaging features have a definite pathological basis and could help make differential diagnoses between IPH and cirrhosis.