bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of miRNAs associated with dendritic cell dysfunction during acute and chronic hepatitis B virus infection
Authors: Singh Avishek Kumar , Rooge Sheetalnath Babasaheb , Varshney Aditi , Vasudevan Madavan , Kumar Manoj , Geffers Robert , Kumar Vijay , Sarin Shiv Kumar
Published: October 2020

The uptake or expression of hepatitis B virus (HBV) proteins by dendritic cells (DCs) is considered important for disease outcome. Differential expression of microRNA (miRNA) may have a role in viral persistence and hepatocellular injury. The miRNA expression was investigated by microarray in DCs from different stages of HBV infection and liver disease namely, immune active (IA; n = 20); low replicative (LR; n = 20); HBeAg negative (n = 20); acute viral hepatitis (AVH, n = 20) and healthy controls (n = 20). miRNA levels were analyzed by unsupervised hierarchical clustering and principal component analyses and validated by quantitative polymerase Chain Reaction (qPCR). The miRNA‐messenger RNA (mRNA)regulatory networks identified 19 miRNAs and 12 target gene interactions in major histocompatibility complex and other immune pathways. miR‐2278, miR‐615‐3p, and miR‐3681‐3p were downregulated in the IA group compared to healthy control, miR‐152‐3p and miR‐3613‐3p in the LR group compared to IA group and miR‐152‐3p and miR‐503‐3p in HBe negative compared to LR group. However, miR‐7‐1‐1‐3p, miR‐192‐5p, miR‐195‐5p, and miR‐32‐5p in LR, miR‐342‐3p, and miR‐940 in HBe negative, and miR‐34a‐5p, miR‐130b‐3p, miR‐221‐3p, miR‐320a, miR‐324‐5p, and miR‐484 in AVH were upregulated. Further, qPCR confirmed changes in miRNA levels and their target genes associated with antigen processing and presentation. Thus, a deregulated network of miRNAs‐mRNAs in DCs seems responsible for an impaired immune response during HBV pathogenesis.
Comparing two sample pooling strategies for SARS‐CoV‐2 RNA detection for efficient screening of COVID‐19
Authors: Chen Fenghua , Geng Zhi , Wang Jian , Liuchang Wenbo , Huang Da , Xu Yuandong , Wang Zheng , Wang Lin
Published: October 2020

The emerging pandemic of coronavirus disease 2019 (COVID‐19) has affected over 200 countries and resulted in a shortage of diagnostic resources globally. Rapid diagnosis of COVID‐19 is vital to control the spreading of the disease, which, however, is challenged by limited detection capacity and low detection efficiency in many parts of the world. The pooling test may offer an economical and effective approach to increase the virus testing capacity of medical laboratories without requiring more laboratory resources such as laboratory workers, testing reagents, and equipment. In this study, the sample pools of 6 and 10 were detected by a real‐time reverse transcription‐polymerase chain reaction assay targeting ORF1ab and N genes of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Each pool consisted of five or nine negative SARS‐CoV‐2 samples and one positive counterpart with varying viral loads. Two different strategies of sample pooling were investigated and the results were compared comprehensively. One approach was to pool the viral transport medium of the samples in the laboratory, and the other was to pool swab samples during the collection process. For swab pooling strategy, qualitative results of SARS‐CoV‐2 RNA, specific tests of ORF1ab and N genes, remained stable over the different pool sizes. Together, this study demonstrates that the swab pooling strategy may serve as an effective and economical approach for screening SARS‐CoV‐2 infections in large populations, especially in countries and regions where medical resources are limited during the pandemic and may thus be potential for clinical laboratory applications.
Discharge may not be the end of treatment: Pay attention to pulmonary fibrosis caused by severe COVID‐19
Authors: Zhang Chi , Wu Zhao , Li Jia‐Wen , Tan Kangan , Yang Wanna , Zhao Hong , Wang Gui‐Qiang
Published: October 2020

Since December 2019, coronavirus disease (COVID‐19) has rapidly swept the world. So far, more than 30 million people have been infected and nearly one million have died. Although the world is still in the stage of COVID‐19 pandemic, the treatment of new cases and critically ill patients is the focus of the current work. However, COVID‐19 patients lead to pulmonary fibrosis, such a serious threat to the prognosis of complications were also worthy of our attention. First of all, we proposed the possible mechanism of pulmonary fibrosis caused by SARS‐CoV‐2, based on the published data of COVID‐19 ((i) Direct evidence: pulmonary fibrosis was found in autopsy and pulmonary puncture pathology. (ii) Indirect evidence: increased levels of fibrosis‐related cytokines[transforming growth factor [TGF]‐ β, tumor necrosis factor [TNF]‐ α, interleukin [IL]‐6, etc] in peripheral blood of severe patients.) What is more, we summarized the role of three fibrosis‐related signaling pathways (TGF‐ β signal pathway, WNT signal pathway and YAP/TAZ signal pathway) in pulmonary fibrosis. Finally, we suggested the therapeutic value of two drugs (pirfenidone and nintedanib) for idiopathic pulmonary fibrosis in COVID‐19‐induced pulmonary fibrosis.
Cy3‐tilmanocept labeling of macrophages in joints of mice with antibody‐induced arthritis and synovium of human patients with rheumatoid arthritis
Authors: Toribio Ramiro E. , Young Nicholas , Schlesinger Larry S. , Cope Fred O. , Ralph David A. , Jarjour Wael , Rosol Thomas J.
Published: October 2020

γ‐Tilmanocept (99mTc‐tilmanocept) is a receptor‐directed, radiolabeled tracer that is FDA‐approved for guiding sentinel lymph node biopsy. Tilmanocept binds the C‐type lectin mannose receptor (MR, CD206) on macrophages. In this study, nonradioactive, fluorescently‐labeled Cy3‐tilmanocept was used to detect CD206+ mononuclear cells in the cartilage of mice with antibody‐induced arthritis and in the synovial fluid and tissue of human subjects with rheumatoid arthritis (RA) for comparison with osteoarthritis (OA), and healthy volunteer (HV) controls. Murine arthritis was induced by injection of monoclonal anti‐cartilage antibody followed by injection of Escherichia coli lipopolysaccharide. Post‐arthritis development (7–11 days), the mice were injected intravenously with Cy3‐tilmanocept followed by in vivo and ex vivo epifluorescence imaging. Two‐photon imaging, immunofluorescence, and immunohistochemistry were used to identify articular and synovial macrophages (CD206, F4/80, and Cy3‐tilmanocept binding) in murine tissues. Cy3‐tilmanocept epifluorescence was present in arthritic knees and elbows of murine tissues; no radiographic changes were noted in the skeletons. However, inflammatory arthritic changes were apparent by histopathology and immunohistochemistry (F4/80), immunofluorescence (CD206) and Cy3‐tilmanocept binding. In human RA synovial fluid, Cy3‐tilmanocept staining correlated with CD206+/CD16+ cells; negligible labeling was observed in OA samples. Cy3‐tilmanocept colocalized with CD206 and staining was significantly higher in RA synovial tissue compared to OA or HV. Our results demonstrate that imaging with Cy3‐tilmanocept can detect in vivo inflammatory, CD206+ macrophages in an early arthritis animal model and in human RA patients. These data establish a novel tool for preclinical research of early arthritis and have implications for early RA detection and monitoring of therapeutic efficacy in humans.
Clinical, radiographic, and patient‐centered outcomes after use of enamel matrix proteins for the treatment of intrabony defects in patients with aggressive periodontitis: A 12‐month multicenter clinical trial
Authors: Fileto Mazzonetto Ana Lívia , Casarin Renato Corrêa Viana , Santamaria Mauro Pedrine , Andere Naira Maria Rebelatto Bechara , Araújo Cássia Fernandes , Videira Clima da Silva Rafaela , Purisaca Javier Eduardo Vivanco , Sallum Enilson Antonio , Sallum Antonio Wilson
Published: October 2020

Background

The aim of this study was to evaluate the clinical, radiographic and patient‐centered results of enamel matrix derivative (EMD) therapy in intrabony defects in aggressive periodontitis (AgP) patients and compare them with those in chronic periodontitis (CP) patients.

Methods

Sixty intrabony defects in AgP and CP patients associated with ≥ 6 mm residual probing pocket depth (PPD) were included and randomly assigned to one of three groups: AgP+CS (conservative surgery) (n = 20); AgP+CS/EMD (n = 20); CP+CS/EMD (n  =  20). Clinical parameters were measured at baseline and after 6 and 12 months. Defect resolution (DR) and bone filling (BF) were used for radiographic analysis. The quality of life was recorded at baseline and 6 months using OHIP‐14 and VAS scale in the early post‐therapy period.

Results

PPD and relative clinical attachment level (rCAL) improved for all groups during follow‐up (P ≤ 0.05), and AgP+CS/EMD presented a higher rCAL gain (2.4 ± 1.0 mm) when compared to AgP control patients (1.6 ± 1.6 mm, P ≤ 0.05) after 12 months. No difference was observed between AgP+CS/EMD and CP+CS/EMD groups (P > 0.05). No radiographic differences were observed among groups at any time point (P > 0.05). All the groups reported a positive impact on OHIP‐14 total score, without differences among them.

Conclusions

EMD therapy of intrabony defects promotes additional benefits in AgP patients, presenting a similar regeneration rate compared to CP patients, and has proven to be a viable therapy for the treatment of individuals with AgP.
Lattice dynamics and high‐pressure properties of K‐ionic conducting system KNbTeO6
Authors: Paraguassu Waldeci , Knyazev Alexander V. , Corrêa Gregório B. , Blokhina A.G. , Demidov D.N. , Ghosh Angsula
Published: October 2020

In the present work, we report results of high‐pressure Raman scattering spectroscopy, on the ionic conducting system KNbTeO6, as well as lattice dynamics calculations for this compound. From lattice dynamics calculation, we were able to do a definite assignment of modes for this system taking into account the disorder caused by random K occupation and shared occupation of Nb and Te ions. On the basis of the theoretical results, we discuss the changes observed in the high‐pressure Raman spectra. We report a transformation occurring around 4.7 GPa, attributed it to a structural phase transition. The Raman spectra during the decompression process reveals that all changes undergone by the structure are reversible, and the Raman spectrum recovers its original signature.
Demonstration of protein capture and separation using three‐dimensional printed anion exchange monoliths fabricated in one‐step
Authors: Simon Ursula , Scorza Livia C T , Teworte Sarah , McCormick Alistair J , Dimartino Simone
Published: October 2020

Three‐dimensional printing applications in separation science are currently limited by the lack of materials compatible with chromatographic operations and three‐dimensional printing technologies. In this work, we propose a new material for Digital Light Processing printing to fabricate functional ion exchange monoliths in a single step. Through copolymerization of the bifunctional monomer [2‐(acryloyloxy)ethyl] trimethylammonium chloride, monolithic structures with quaternary amine ligands were fabricated. The novel formulation was optimized in terms of protein binding and recovery, microporous structure, and its swelling susceptibility by increasing its cross‐link density and employing cyclohexanol and dodecanol as pore forming agents. In static conditions, the material demonstrated a maximum binding capacity of 104.2 ± 10.6 mg/mL for bovine serum albumin, in line with commercially available materials. Its anion exchange behavior was validated by separating bovine serum albumin and myoglobin on a monolithic bed with Schoen gyroid morphology. The same column geometry was tested for the purification of C‐phycocyanin from clarified as well as cell‐laden Arthrospira platensis feedstocks. This represents the first demonstration of one‐step printed stationary phases to capture proteins directly from solid‐laden feedstocks. We believe that the material presented here represents a significant improvement towards implementation of three‐dimensional printed chromatography media in the field of separation science.
Rapid characterization of the chemical constituents of Duzhong Jiangya tablet by HPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry
Authors: Li Jingwei , Wang Miao , Wang Xue , Sun Lin , Zhao Chunjie , Zhao Min
Published: October 2020

Duzhong Jiangya tablet is a hypotensive drug. In this study, high‐performance liquid chromatography‐Fourier transform‐ion cyclotron resonance‐mass spectrometry technology was used to quickly identify its chemical composition. SinoChrom ODS‐BP column (250 mm × 4.6 mm, 5 μm) was used. The mobile phase was acetonitrile(A)‐0.1% formic acid solution(B). The flow rate was 1 mL/min. Extracted ion chromatogram was used to analyze the samples in positive and negative ion modes. Based on the accurate mass spectrometry information (such as quasi‐molecular ions and fragment ions) obtained from the instrument, combined with reference compounds and literature, the chemical composition of Duzhong Jiangya Tablets was identified. A total of 131 compounds were identified, including four types of penylpropanoids, six types of phenylethanoid glycosides, 10 types of organic acids, 14 types of iridoids, 12 types of lignans, 18 types of alkaloids, seven types of coumarins, and 60 kinds of flavonoids. This established method can quickly and efficiently identify chemical constituents in Duzhong Jiangya tablet, lay a foundation for the research on the efficacy and quality of this traditional Chinese medicine, and provide a reference for the characterization of the chemical constituents of other traditional Chinese medicine preparations.
The role of sample preparation in multidimensional gas chromatographic separations for non‐targeted analysis with the focus on recent biomedical, food, and plant applications
Authors: Franchina Flavio A. , Zanella Delphine , Dubois Lena M. , Focant Jean‐François
Published: October 2020

In this review, we consider and discuss the affinity and complementarity between a generic sample preparation technique and the comprehensive two‐dimensional gas chromatography process. From the initial technical development focus (e.g., on the GC×GC and solid‐phase microextraction techniques), the trend is inevitably shifting toward more applied challenges, and therefore, the preparation of the sample should be carefully considered in any GC×GC separation for an overreaching research. We highlight recent biomedical, food, and plant applications (2016–July 2020), and specifically those in which the combination of tailored sample preparation methods and GC×GC–MS has proven to be beneficial in the challenging aspects of non‐targeted analysis. Specifically on the sample preparation, we report on gas‐phase, solid‐phase, and liquid‐phase extractions, and derivatization procedures that have been used to extract and prepare volatile and semi‐volatile metabolites for the successive GC×GC analysis. Moreover, we also present a milestone section reporting the early works that pioneered the combination of sample preparation techniques with GC×GC for non‐targeted analysis.
Transparency Change Mechanochromism Based on a Robust PDMS‐Hydrogel Bilayer Structure
Authors: Xu Yonghang , Zeng Songshan , Xian Weikang , Lin Limiao , Ding Hao , Liu Jingjing , Xiao Min , Wang Shuanjin , Li Ying , Meng Yuezhong , Sun Luyi
Published: October 2020

Hydrogels and polydimethylsiloxane (PDMS) are complementary to each other, since the hydrophobic PDMS provides a more stable and rigid substrate, while the water‐rich hydrogel possesses remarkable hydrophilicity, biocompatibility, and similarity to biological tissues. Herein a transparent and stretchable covalently bonded PDMS‐hydrogel bilayer (PHB) structure is prepared via in situ free radical copolymerization of acrylamide and allylamine‐exfoliated‐ZrP (AA‐e‐ZrP) on a functionalized PDMS surface. The AA‐e‐ZrP serves as cross‐linking nano‐patches in the polymer gel network. The covalently bonded structure is constructed through the addition reaction of vinyl groups of PDMS surface and monomers, obtaining a strong interfacial adhesion between the PDMS and the hydrogel. A mechanical‐responsive wrinkle surface, which exhibs transparency change mechanochromism, is created via introducing a cross‐linked polyvinyl alcohol film atop the PHB structure. A finite element model is implemented to simulate the wrinkle formation process. The implication of the present finding for the interfacial design of the PHB and PDMS‐hydrogel‐PVA trilayer (PHPT) structures is discussed.
Measuring Functional Status in Huntington's Disease
Authors: Gibson Jessie S. , Ridner Sheila H. , Dietrich Mary S. , Sohn Michael B. , Rhoten Bethany A. , Claassen Daniel O.
Published: October 2020

Background

Neuropsychiatric and cognitive symptoms account for substantial morbidity in Huntington's disease (HD), but their impact on functional status may not be captured using the Total Functional Capacity (TFC) scale. The objective of this study was to assess the impact of motor, cognitive, and neuropsychiatric symptoms on functional status in persons with HD, comparing two instruments.

Methods

Multiple regression analyses assessed the relationship between neuropsychiatric, cognitive, and motor symptoms and functional status as measured using TFC and Adult Functional Adaptive Behavior (AFAB) scales.

Results

Greater burden of neuropsychiatric (P = 0.017), cognitive (P = 0.001), and motor (P = 0.001) symptoms was associated with greater impairments to functional status as measured by the AFAB scale. Only motor symptoms were associated with TFC scores (P = 0.002). The 3 symptom domains explained more of the variance in AFAB than TFC scores (P = 0.016).

Conclusions

TFC may have limited applicability, particularly in early‐stage HD patients, as a measure of functional status. The AFAB scale can be used in HD studies as a more holistic measure of functional status. © 2020 International Parkinson and Movement Disorder Society
Analysis of expression levels of markers associated with tumor proliferation and angiogenesis in familial adenomatous polyposis
Authors: Zhang Zhao , Wang Dan , Xu Chen , Li Yuwei , Yu Yongjun , Chen Chao , Li Mingsen , Zhang Xipeng
Published: October 2020

Background

Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary disease with colorectal adenomatous polyps as the main clinical manifestations. The objective of this study was to analyze and compare the expression levels of tumor proliferation and angiogenesis‐related genes in different tissue sections of FAP patients through qPCR, western blot, and immunohistochemistry (IHC) analysis.

Methods

Seventeen patients with FAP admitted to Tianjin Union Medical Center from January 2010 to June 2015 were selected, and then, normal intestinal mucosa, polyp tissue, or cancerous polyp tissue were collected. QPCR, western blot, and IHC were used to detect the expression level of genes or proteins correlated with tumor proliferation.

Results

The mRNA expression of CD31 in large polyp tissue was significantly higher than that in normal tissue and small polyp tissue. Compared with normal tissue and polyp tissue, the expression level of KI67 mRNA in cancer tissue was remarkably increased. The VEGFA mRNA and CDH5 mRNA expression in both polyp and cancer tissues were prominently lower than those in normal tissue. The expression of CD31 protein in cancer tissue was lower than that in normal tissue and polyp tissue, whereas the expression levels of VEGF, CDH5, and KI67 protein were widely higher than that in normal tissue and polyp tissue.

Conclusion

Abnormal expressions of CD31, KI67, VEGF(A), and CDH5 were associated with the carcinogenesis of FAP.
Precision radiotherapy using monochromatic inverse Compton x‐ray sources
Authors: Simiele Eric A. , Breitkreutz Dylan Y. , Capaldi Dante P. I. , Liu Wu , Bush Karl K. , Skinner Lawrie B.
Published: October 2020

Purpose

The dosimetric properties of inverse Compton (IC) x‐ray sources were investigated to determine their utility for stereotactic radiation therapy.

Methods

Monte Carlo simulations were performed using the egs brachy user code of EGSnrc. Nominal IC source x‐ray energies of 80 and 150 keV were considered in this work. Depth‐dose and lateral dose profiles in water were calculated, as was dose enhancement in the bone. Further simulations were performed for brain and spine treatment sites. The impact of gold nanoparticle doping was also investigated for the brain treatment site. Analogous dose calculations were performed in a clinical treatment planning system using a clinical 6 MV photon beam model and were compared to the Monte Carlo simulations.

Results

Both 80 and 150 keV IC beams were observed to have sharp 80–20 penumbra (i.e., < 0.1 mm) with broad low‐dose tails in water. For reference, the calculated penumbra for the 6 MV clinical beam was 3 mm. Maximum dose enhancement factors in bone of 3.1, 1.4, and 1.1 were observed for the 80, 150 keV, and clinical 6 MV beams, respectively. The plan quality for the single brain metastasis case was similar between the IC beams and the 6 MV beam without gold nanoparticles. As the concentration of gold within the target increased, the V12 Gy to the normal brain tissue and within the target volume significantly decreased and the conformity significantly improved, which resulted in superior plan quality over the clinical 6 MV beam plan. In the spine cases, the sharp penumbra and enhanced dose to bone of the IC beams produced superior plan quality (i.e., better conformity, normal tissue sparing, and spinal cord sparing) as compared to the clinical 6 MV beam plans.

Conclusions

The findings from this work indicate that inverse Compton x‐ray sources are well suited for stereotactic radiotherapy treatments due to their sharp penumbra and dose enhancement around high atomic number materials. Future work includes investigating the properties of intensity‐modulated inverse Compton x‐ray sources to improve the homogeneity within the target tissue.
B0 and B1 inhomogeneities in the liver at 1.5 T and 3.0 T
Authors: Roberts Nathan T. , Hinshaw Louis A. , Colgan Timothy J. , Ii Takanori , Hernando Diego , Reeder Scott B.
Published: October 2020

Purpose

The purpose of this work is to characterize the magnitude and variability of B0 and B1 inhomogeneities in the liver in large cohorts of patients at both 1.5 T and 3.0 T.

Methods

Volumetric B0 and B1 maps were acquired over the liver of patients presenting for routine abdominal MRI. Regions of interest were drawn in the nine Couinaud segments of the liver, and the average value was recorded. Magnitude and variation of measured averages in each segment were reported across all patients.

Results

A total of 316 B0 maps and 314 B1 maps, acquired at 1.5 T and 3.0 T on a variety of GE Healthcare MRI systems in 630 unique exams, were identified, analyzed, and, in the interest of reproducible research, de‐identified and made public. Measured B0 inhomogeneities ranged (5th‐95th percentiles) from −31.7 Hz to 164.0 Hz for 3.0 T (−14.5 Hz to 81.3 Hz at 1.5 T), while measured B1 inhomogeneities (ratio of actual over prescribed flip angle) ranged from 0.59 to 1.13 for 3.0 T (0.83 to 1.11 at 1.5 T).

Conclusion

This study provides robust characterization of B0 and B1 inhomogeneities in the liver to guide the development of imaging applications and protocols. Field strength, bore diameter, and sex were determined to be statistically significant effects for both B0 and B1 uniformity. Typical clinical liver imaging at 3.0 T should expect B0 inhomogeneities ranging from approximately −100 Hz to 250 Hz (−50 Hz to 150 Hz at 1.5 T) and B1 inhomogeneities ranging from approximately 0.4 to 1.3 (0.7 to 1.2 at 1.5 T).
Highly accelerated aortic 4D flow MRI using compressed sensing: Performance at different acceleration factors in patients with aortic disease
Authors: Pathrose Ashitha , Ma Liliana , Berhane Haben , Scott Michael B. , Chow Kelvin , Forman Christoph , Jin Ning , Serhal Ali , Avery Ryan , Carr James , Markl Michael
Published: October 2020

Purpose

To systematically assess the feasibility and performance of a highly accelerated compressed sensing (CS) 4D flow MRI framework at three different acceleration factors (R) for the quantification of aortic flow dynamics and wall shear stress (WSS) in patients with aortic disease.

Methods

Twenty patients with aortic disease (58 ± 15 y old; 19 M) underwent four 4D flow scans: one conventional (GRAPPA, R = 2) and three CS 4D flows with R = 5.7, 7.7, and 10.2. All scans were acquired with otherwise equivalent imaging parameters on a 1.5T scanner. Peak‐systolic velocity (Vmax), peak flow (Qmax), and net flow (Qnet) were quantified at the ascending aorta (AAo), arch, and descending aorta (DAo). WSS was calculated at six regions within the AAo and arch.

Results

Mean scan times for the conventional and CS 4D flows with R = 5.7, 7.7, and 10.2 were 9:58 ± 2:58 min, 3:40 ± 1:19 min, 2:50 ± 0:56 min, and 2:05 ± 0:42 min, respectively. Vmax, Qmax, and Qnetwere significantly underestimated by all CS protocols (underestimation ≤ −7%, −9%, and −10% by CS, R = 5.7, 7.7, and 10.2, respectively). WSS measurements showed the highest underestimation by all CS protocols (underestimation ≤ −9%, −12%, and −14% by CS, R = 5.7, 7.7, and 10.2).

Conclusions

Highly accelerated aortic CS 4D flow at R = 5.7, 7.7, and 10.2 showed moderate agreement with the conventional 4D flow, despite systematically underestimating various hemodynamic parameters. The shortened scan time may enable the clinical translation of CS 4D flow, although potential hemodynamic underestimation should be considered when interpreting the results.
An equal‐TE ultrafast 3D gradient‐echo imaging method with high tolerance to magnetic susceptibility artifacts: Application to BOLD functional MRI
Authors: Ryu Jae‐Kyun , Jung Won Beom , Yu Jaeyong , Son Jeong Pyo , Lee Seung‐Kyun , Kim Seong‐Gi , Park Jang‐Yeon
Published: October 2020

Purpose

To develop an ultrafast 3D gradient echo–based MRI method with constant TE and high tolerance to B0 inhomogeneity, dubbed ERASE (equal‐TE rapid acquisition with sequential excitation), and to introduce its use in BOLD functional MRI (fMRI).

Theory and Methods

Essential features of ERASE, including spin behavior, were characterized, and a comparison study was conducted with conventional EPI. To demonstrate high tolerance to B0 inhomogeneity, in vivo imaging of the mouse brain with a fiber‐optic implant was performed at 9.4 T, and human brain imaging (including the orbitofrontal cortex) was performed at 3 T and 7 T. To evaluate the performance of ERASE in BOLD‐fMRI, the characteristics of SNR and temporal SNR were analyzed for in vivo rat brains at 9.4 T in comparison with multislice gradient‐echo EPI. Percent signal changes and t‐scores are also presented.

Results

For both mouse brain and human brain imaging, ERASE exhibited a high tolerance to magnetic susceptibility artifacts, showing much lower distortion and signal dropout, especially in the regions involving large magnetic susceptibility effects. For BOLD‐fMRI, ERASE provided higher temporal SNR and t‐scores than EPI, but exhibited similar percent signal changes in in vivo rat brains at 9.4 T.

Conclusion

When compared with conventional EPI, ERASE is much less sensitive, not only to EPI‐related artifacts such as Nyquist ghosting, but also to B0 inhomogeneity including magnetic susceptibility effects. It is promising for use in BOLD‐fMRI, providing higher temporal SNR and t‐scores with constant TE when compared with EPI, although further optimization is needed for human fMRI.
Deep learning reconstruction for cardiac magnetic resonance fingerprinting T1 and T2 mapping
Authors: Hamilton Jesse I. , Currey Danielle , Rajagopalan Sanjay , Seiberlich Nicole
Published: October 2020

Purpose

To develop a deep learning method for rapidly reconstructing T1 and T2 maps from undersampled electrocardiogram (ECG) triggered cardiac magnetic resonance fingerprinting (cMRF) images.

Methods

A neural network was developed that outputs T1 and T2 values when given a measured cMRF signal time course and cardiac RR interval times recorded by an ECG. Over 8 million cMRF signals, corresponding to 4000 random cardiac rhythms, were simulated for training. The training signals were corrupted by simulated k‐space undersampling artifacts and random phase shifts to promote robust learning. The deep learning reconstruction was evaluated in Monte Carlo simulations for a variety of cardiac rhythms and compared with dictionary‐based pattern matching in 58 healthy subjects at 1.5T.

Results

In simulations, the normalized root‐mean‐square error (nRMSE) for T1 was below 1% in myocardium, blood, and liver for all tested heart rates. For T2, the nRMSE was below 4% for myocardium and liver and below 6% for blood for all heart rates. The difference in the mean myocardial T1 or T2 observed in vivo between dictionary matching and deep learning was 3.6 ms for T1 and −0.2 ms for T2. Whereas dictionary generation and pattern matching required more than 4 min per slice, the deep learning reconstruction only required 336 ms.

Conclusion

A neural network is introduced for reconstructing cMRF T1 and T2 maps directly from undersampled spiral images in under 400 ms and is robust to arbitrary cardiac rhythms, which paves the way for rapid online display of cMRF maps.
Metal–organic framework polymer composite enhancement via acyl chloride modification
Authors: Peterson Gregory W , Wang Hui , Au Kathleen , Epps Thomas H
Published: October 2020

Ideal mixed‐matrix composites fabricated from metal–organic frameworks (MOFs) and polymers should exhibit good compatibility between components, high adsorptivity, and fast and efficient reactivity. Often, poor compatibility between MOFs and polymers results in interfacial defects, which lead to underperforming materials. In this work the MOF UiO‐66‐NH2 was modified using various acyl chlorides to tailor MOF compatibility and dispersion within mixed‐matrix composites and electrospun fibers to enable better protective suits and filters. MOF crystal structures were unaffected and high surface areas were present after acyl chloride treatment. Most treated MOFs had increased reactivity towards soman (GD) and the simulant dimethyl p‐nitrophenylphosphate relative to the baseline MOF, and this enhanced reactivity was probably because of better wetting behavior towards the agents. Chlorine and 2‐chloroethyl ethyl sulfide uptake of modified MOFs was similar to uptake in the baseline MOF, while nitrogen dioxide and GD sorption capacity decreased for all modified MOFs due to exhaustion of amine sites and pore blockage, respectively. Overall, modification of the MOF with acyl chlorides resulted in better polymer compatibility, retained adsorption capacity for multiple chemicals and even increased reactivity towards GD. The structure–activity processing insights gained from this work will lead to the design of more effective protection equipment such as filters, clothing/suits and membranes. Published 2020. This article is a U.S. Government work and is in the public domain in the USA
A bottom‐up cost analysis of silicon–perovskite tandem photovoltaics
Authors: Chang Nathan L. , Zheng Jianghui , Wu Yiliang , Shen Heping , Qi Fred , Catchpole Kylie , Ho‐Baillie Anita , Egan Renate J.
Published: October 2020

Stacking two photovoltaic (PV) cells to form a tandem structure can improve the efficiency of PV modules, and if achieved at sufficiently low cost, could dominate the PV market in the future. Rapid progress in silicon–perovskite tandem (SPT) cell efficiency has been made, so cost modelling is becoming important in analysing the commercial attractiveness of this approach. While previous cost modelling assumed idealised production processes, this work focuses first on six demonstrated SPT sequences using both homojunction and heterojunction bottom silicon cells, analysed in detail using a bottom‐up cost and uncertainty model and then compared with other reported SPT high‐efficiency cells. This identifies cost barriers in the perovskite cell, including high‐cost hole transport material (HTM) and electron transport layer (ETL) materials such as (2,2′,7,7′‐tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9′‐spirobifluorene [SPIRO] and [6,6]‐phenyl‐C61‐butyric acid methyl ester [PCBM]), and the use of spin coating which has a high wastage rate. Once these cost issues are solved, the silicon cell cost becomes important, and the use of lower cost homojunction cells with p‐type wafers can further reduce costs. A hypothetical medium term low‐cost sequence that combines the lowest cost parts of the analysed sequences and an improved perovskite deposition process has a projected likely cost of $1.50/cell, which if combined with 25% efficiency would give a favourable levelised cost of electricity (LCOE) compared with industry standard c‐Si cells. This analysis guides research directions to address cost issues in parallel with higher efficiencies in this technology area.
Unraveling the effect of fluorine substitution on the hydrogen bonding interaction in the complexes of fluorosubstituted pyridines and acetic acid
Authors: Li Chaozheng , Cao Yonghua , Hu Bo , Li Yongfeng
Published: October 2020

The effect of fluorine substitution on the hydrogen bonding interaction in the complexes of fluorosubstituted pyridines and acetic acid was examined through theoretical method. Two types of double hydrogen bonding cyclic structures have been predicted, one with O–H···N and C–H···O interactions and the other with O–H···F and C–H···O interactions. The changes of the hydrogen bonding interactions are visualized by the reduced density gradient (RDG) and bond critical point (BCP) parameters analysis. With increasing in fluorination, the C–H···O bond strength increases, and the O–H···N and O–H···F bond strengths decrease. Although the O–H···N and O–H···F hydrogen bond energies decrease, the bond type has not changed in all of the fluorinated complexes. For the same degree of fluorination complexes, fluorine favors the C–H···O hydrogen bonding interaction through the cooperating of O–H···F and C–H···O hydrogen bonds, although fluorine is a weak hydrogen bond acceptor. The natural population analysis (NPA) and molecular electrostatic potentials (ESP) were adopted to further explore the variation characteristics of hydrogen bond strength. We found that the substituent fluorine atom acts as a role of electron withdrawing. The pyridine ring nitrogen atom and 2‐position fluorine atom become less negative, and the remaining H atom(s) become more electropositive with increasing degree of fluorination. The hydrogen bond strength is correlated with the charge redistribution of the proton H and acceptor (N and F) atoms.
Charge Transport Mechanism in Atomic Layer Deposited Oxygen‐Deficient TaOx Films
Authors: Gismatulin Andrei , Gritsenko Vladimir , Perevalov Timofey , Kuzmichev Dmitry , Chernikova Anna , Markeev Andrey
Published: October 2020

TaOx is a promising candidate for random access memory formation. To provide the possibility of 3D integration, it is grown by the atomic layer deposition (ALD). Herein, such properties of the pristine TaOx grown by radical‐enhanced ALD (REALD) as oxygen vacancies concentration and the trap energy are evaluated to reveal whether it can replace more common ion‐sputtered TaOx both in filamentary and nonfilamentary resistive random access memory (ReRAM) stacks. For this purpose, charge transport mechanism in the TiN/TaOx/Pt stacks is analyzed. It is found that charge transport through TaOx is described by the phonon‐assisted tunneling between traps model. The thermal Wt  = 0.85 eV and optical Wopt  = 1.7 eV trap energies are determined. The trap concentration N = 1 × 1021 cm−3 found from transport corresponds well with the oxygen vacancy concentration, obtained by ab initio simulation of valence band X‐ray photoelectron spectrum. Derived parameters are typical for the ion‐sputtered TaOx. As a result, it can be considered to replace ion‐sputtered TaOx in the nonfilamentary bilayer stacks. Moreover, the observed properties explain the possibility to achieve electroforming‐free resistive switching in a single layer REALD grown TaOx‐based stack in combination with extracting Ta electrode.
A New Criterion for Prediction of Phase Stability in Al‐Containing High Entropy Alloys
Authors: Li Fangjie , Sha Yeyu , Zeng Xin , Zhang Shidong , Shi Tao , Shen Bingyu , Shen Qin , Liu Min
Published: October 2020

The reliable phase formation rule is demanded for high entropy alloys’ (HEAs) design and property regulation. Previous studies reveal the significant roles of thermodynamic and geometrical parameters in predicting phase structures of HEAs, whereas an accurate criterion is still not available. Herein, taking the most extensively studied Al‐containing HEAs as research object, two alloying parameters, i.e., d‐orbital energy level (Md) and bond order (Bo), combining with valence electron concentration (VEC) and atomic size difference (δ), are introduced to explore the phase stability of Al‐containing HEAs. The results indicate that single FCC solid solution tends to form in the range of δ below 4.5%, ordered phases (such as B2 and intermetallics) are more likely to be produced when the Md value of the alloy is beyond 1.06, and the FCC + BCC dual‐phase structures are mainly concentrated in the region of δ > 4.5% and Md < 1.06. The Md–δ criterion provides a reliable criterion of phase stability and a good guidance in alloy design for Al‐containing HEAs.
Moulded pulp products manufacturing with thermoforming
Authors: Didone Mattia , Tosello Guido
Published: October 2020

For an effective optimization of pulp thermoforming and of the moulded pulp products manufactured by this process, a full understanding of the process physics combined with full knowledge of the pressing equipment is necessary. For this reason, in this Addendum, we clarify how the process parameters “Holding time,” “Vacuum time,” “Cycle time,” and “Temperature” were interpreted and subsequently defined for the analysis of the process and product‐related outputs of the thermoforming experiments.
New technology‐based assistive techniques in total knee arthroplasty: A Bayesian network meta‐analysis and systematic review
Authors: Gao Jiaxiang , Dong Shengjie , Li Jiao Jiao , Ge Long , Xing Dan , Lin Jianhao
Published: October 2020

Background

The radiological and clinical efficiency among robot‐assisted surgery (RAS), computer‐assisted navigation system (CAS) and conventional (CON) total knee arthroplasty (TKA) remains controversial.

Methods

Bayesian network meta‐analysis (NMA) and systematic review were performed to investigate radiological and clinical efficiency, respectively. The certainty of the evidence was evaluated using Grading of Recommendations, Assessment, Development and Evaluation and Confidence in the Evidence from Reviews of Qualitative tools.

Results

Thirty‐four RCTs (7289 patients and 7424 knees) were included. The NMA showed that RAS‐TKA had the highest probability for mechanical axis restoration (odds ratio for RAS vs. CAS 3.79, credible interval [CrI] 1.14–20.54, very low certainty), followed by CAS‐TKA (odds ratio for CAS vs. CON 2.55, CrI 1.67–4.01, very low certainty) and then CON‐TKA, without significant differences in other radiological parameters. No differences were found in clinical outcomes after qualitative systematic review (overall low certainty).

Conclusions

Technology‐based assistive techniques (CAS and RAS) may surpass the CON‐TKA, when considering higher radiological accuracy and comparable clinical outcomes.
Soil microbial community characteristics in a vineyard ten years after fumigation
Authors: Dangi Sadikshya , Wang Dong
Published: October 2020

California is the number one producer of grapes in the United States. Soil fumigation has been used to control soilborne pests and pathogens. However, fumigants can potentially have a negative impact on native soil microbial populations. Given the roles of microorganisms in the soil system, it is important to assess the long‐term impact of fumigation on soil microbial communities, which is currently lacking. The objective of this research was to study the long‐term impact of microbial communities in grapevine (Vitis vinifera L.) replanting situations after fumigation. Soil treatments included methyl bromide (MeBr), Telone C35, InLine, a nonfumigated control, and a mustard (Sinapis alba L.) cover crop in two side‐by‐side field experiments fumigated in 2007 and 2008. Microbial community biomass in 2017 and 2018 did not differ between fumigated and nonfumigated plots at the 0‐ to 30‐cm depth. However, plots with shank‐injected MeBr and Telone C35 applied in 2008 showed significantly reduced microbial biomass in 2018 at deeper depths than subsurface drip‐applied InLine plots. The results show the impact of fumigation on bacterial communities; however, the impact on fungal and arbuscular mycorrhizal fungi (AMF) communities was not evident after 10 years. Furthermore, the effect of depth was apparent on bacterial communities compared with fungal and AMF communities. The data suggest that deep‐rooted grapevines influenced fungal populations, which probably supplied labile C in fumigated and nonfumigated plots. Future research needs to focus collectively on the long‐term effects of fumigation on fruit quality and yield in vineyards, and on soil microbial communities.
Platform ecosystems as meta‐organizations: Implications for platform strategies
Authors: Kretschmer Tobias , Leiponen Aija , Schilling Melissa , Vasudeva Gurneeta
Published: October 2020

Research summary

Platform ecosystems have spurred new products and services, sparked innovation, and improved economic efficiency in various industries and technology sectors. A distinctive feature of the platform architecture is its modular and interdependent system of core and complementary components bound together by design rules and an overarching value proposition. Accordingly, we conceptualize platforms as meta‐organizations, or “organizations of organizations” that are less formal and less hierarchical structures than firms, and yet more closely coupled than traditional markets. To function successfully, however, platforms require coordination among multiple participants not all of whose interests are aligned. These organizational features of platforms raise many interesting and complex strategic challenges and hold implications for how platforms compete. In this paper, we discuss some of the most salient features of platform ecosystems as meta‐organizations, specifically in terms of the sources of authority or power in the ecosystem, the motivation and incentives a platform creates to attract participants, and its governance and coordination structures. We then consider how papers appearing in this special issue inform us about the effects of these features on platform competition along three distinct dimensions: (a) with traditional incumbents as platforms enter and establish themselves in new markets, (b) with other platforms to secure an advantageous market position, and (c) with the different participants on the platform to share the value that has been created jointly. We close by identifying some promising directions for future research.

Managerial summary

Platform ecosystems have spurred new products and services, sparked innovation, and improved economic efficiency in various industries and technology sectors. A distinctive feature of the platform architecture is its modular and interdependent system of core and complementary components bound together by design rules and an overarching value proposition. This makes platform ecosystems an organizational form on its own (a “meta‐organization”), neither possessing the hierarchical instruments of a firm, nor the largely uncoordinated decisionmaking of markets. Successful platform ecosystems require coordination among multiple participants with possibly conflicting interests. We discuss some of the most salient features of platform ecosystems as meta‐organizations, specifically in terms of the sources of authority or power in the ecosystem, the motivation and incentives a platform creates to attract participants, and its governance and coordination structures. These features affect how platform ecosystems compete: i) with a traditional incumbent, ii) with other platform ecosystems, and iii) between different participants of the same platform ecosystem. The articles published in this special issue speak to different aspects of platform competition from the perspective of organization design.
Work‐from‐anywhere: The productivity effects of geographic flexibility
Authors: Choudhury Prithwiraj (Raj) , Foroughi Cirrus , Larson Barbara
Published: October 2020

Research Summary

An emerging form of remote work allows employees to work‐from‐anywhere, so that the worker can choose to live in a preferred geographic location. While traditional work‐from‐home (WFH) programs offer the worker temporal flexibility, work‐from‐anywhere (WFA) programs offer both temporal and geographic flexibility. WFA should be viewed as a nonpecuniary benefit likely to be preferred by workers who would derive greater utility by moving from their current geographic location to their preferred location. We study the effects of WFA on productivity at the United States Patent and Trademark Office (USPTO) and exploit a natural experiment in which the implementation of WFA was driven by negotiations between managers and the patent examiners' union, leading to exogeneity in the timing of individual examiners' transition from a work‐from‐home to a work‐from‐anywhere program. This transition resulted in a 4.4% increase in output without affecting the incidence of rework. We also report results related to a plausible mechanism: an increase in observable effort as the worker transitions from a WFH to a WFA program. We employ illustrative field interviews, micro‐data on locations, and machine learning analysis to shed further light on geographic flexibility, and summarize worker, firm, and economy‐wide implications of provisioning WFA.

Managerial Summary

Work‐from‐anywhere is an emerging form of remote work, in which workers are awarded geographic flexibility, that is, the flexibility to choose where to live. We study the productivity effects of workers moving from a work‐from‐home (WFH) to a work‐from‐anywhere (WFA) regime at the United States Patent and Trademark Office (USPTO). Exploiting a natural experiment, we find that the transition from WFH to WFA resulted in a 4.4% increase in employee output, with no increase in rework. We also report an increase in employee effort after the transition to WFA and document qualitative evidence on how geographic flexibility benefits individual workers and the USPTO (e.g., real estate savings).
Nanoparticle‐Enabled Dual Modulation of Phagocytic Signals to Improve Macrophage‐Mediated Cancer Immunotherapy
Authors: Zhang Ya‐Ru , Luo Jia‐Qi , Zhang Jing‐Yang , Miao Wei‐Min , Wu Jia‐Si , Huang Hua , Tong Qi‐Song , Shen Song , Leong Kam W. , Du Jin‐Zhi , Wang Jun
Published: October 2020

Activation of the phagocytosis of macrophages to tumor cells is an attractive strategy for cancer immunotherapy, but the effectiveness is limited by the fact that many tumor cells express an increased level of anti‐phagocytic signals (e.g., CD47 molecules) on their surface. To promote phagocytosis of macrophages, a pro‐phagocytic nanoparticle (SNPACALR&aCD47) that concurrently carries CD47 antibody (aCD47) and a pro‐phagocytic molecule calreticulin (CALR) is constructed to simultaneously modulate the phagocytic signals of macrophages. SNPACALR&aCD47 can achieve targeted delivery to tumor cells by specifically binding to the cell‐surface CD47 and block the CD47‐SIRPα pathway to inhibit the “don't eat me” signal. Tumor cell‐targeted delivery increases the exposure of recombinant CALR on the cell surface and stimulates an “eat me” signal. Simultaneous modulation of the two signals enhances the phagocytosis of 4T1 tumor cells by macrophages, which leads to significantly improved anti‐tumor efficacy in vivo. The findings demonstrate that the concurrent blockade of anti‐phagocytic signals and activation of pro‐phagocytic signals can be effective in macrophage‐mediated cancer immunotherapy.