bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radical‐Mediated Non‐Dearomative Strategies in Construction of Spiro Compounds
Authors: Pawlowski R. , Skorka P. , Stodulski M. 
Published: August 2020

AbstractIn recent years, spirocyclic compounds have attracted a significant interest in medicinal chemistry due to their considerable biological activities. The general and widely used concept for spirocyclic compound synthesis is related with dearomatization of starting material. However, most of the libraries prepared using this concept comprise structure similarity. Therefore, preparation of structurally distinct libraries comprising varied functionality requires different approaches and that includes non‐dearomative pathways. In given review recent advance in the synthesis of structurally varied spirocycles via radical‐mediated non‐dearomative strategies is discussed. In this context, application of radical initiators or photoredox catalysis is described. The variety of the presented examples indicates the high potential of the visible‐light‐induced methodologies in spirocyclic compound synthesis, which can act as a very efficient green alternative to known procedures, offering mild reaction conditions and high functional group tolerance.magnified image
COVID‐19 Policy Modeling in Sub‐Saharan Africa
Authors: Mueller Valerie , Sheriff Glenn , Keeler Corinna , Jehn Megan 
Published: August 2020

AbstractAfter an initial delay, Sub‐Saharan Africa (SSA) is being hit by the pandemic. Demand for exports is falling and caseloads are rising. Governments have approached this crisis with a range of policy options. Optimal policy balances reduced infection rates with lost economic output. This paper discusses how an economic‐epidemiological model used to analyze policy in high‐income countries could be adapted to a context where poverty considerations are paramount. Differences in country characteristics across the continent affect benefits and costs of alternative policy designs. We conclude by highlighting data needs and model calibration challenges for COVID‐19 policy research in SSA.
Beef Cattle Markets and COVID‐19
Authors: Martinez Charles C. , Maples Joshua G. , Benavidez Justin 
Published: August 2020

AbstractCattle producers and markets faced massive disruptions due to COVID‐19 in both supply and demand for cattle and beef. Restaurant and food service shutdowns affected beef demand. Closures and slowdowns of beef processors caused a logjam of live cattle in the supply chain. The resulting effects on cattle producers at all levels were lower prices and abnormal cattle flows, but the magnitudes of those effects were not homogenous across size and type of cattle. In this article, we detail how the COVID‐19 pandemic has affected cattle markets and cattle producers across the different sectors. We also discuss policy responses and considerations.
Effects of row spacing, nitrogen, and mepiquat chloride application on yield and spatio‐temporal patterns of cotton bolls in the yellow river valley of China
Authors: Yan Wei , Li Fangjun , Xu Dongyong , Eneji A. Egrinya , Du Mingwei , Tian Xiaoli , Li Zhaohu 
Published: August 2020

AbstractMechanical harvesting of cotton is an inevitable trend in China due to the current shortage of farm labor. Row spacings of spindle‐type pickers are adjustable between 76 and 102 cm. However, it is not clear which is better for cotton production in the Yellow River Valley. This field study was conducted under stalk incorporation during 2016–2018, and consisted of experiments of row spacing × nitrogen (N) and row spacing × mepiquat chloride (MC). A split‐plot with four replications was used; row spacings (76, 92 and 102 cm) were assigned as main plots at equal population of 90 000 plants ha−1, and N (0, 105, 210 kg ha−1) or MC rates (0, 140, 281 and 394 g ha−1) as subplots. The wider row spacings (92 and 102 cm) yielded as much as the narrower spacing (76 cm) in 2016 and 2018, but out‐yielded the latter in the wet year (2017) due to the greater number of bolls. Nitrogen application had marginal effects on cotton yield. Mepiquat chloride application increased lint yield by increasing boll weight in 2016–2017, but decreased yield by reducing boll number at the highest rate (394 g ha−1) in the dry year of 2018. Considering plants spaced 92 cm more resistant to lodging than those spaced 102 cm, we suggest the 92 cm spacing may be selected. In addition, the 105–210 kg N ha−1and the 140–281 g MC ha−1 were recommended to balance N removal in seed cotton and get higher or stable yield, respectively.
Early detection of black Sigatoka in banana leaves using hyperspectral images
Authors: Ugarte Fajardo Jorge , Bayona Andrade Oswaldo , Criollo Bonilla Ronald , Cevallos‐Cevallos Juan , Mariduena‐Zavala María , Ochoa Donoso Daniel , Vicente Villardón José Luis 
Published: August 2020

PremiseBlack Sigatoka is one of the most severe banana (Musa spp.) diseases worldwide, but no methods for the rapid early detection of this disease have been reported. This paper assesses the use of hyperspectral images for the development of a partial‐least‐squares penalized‐logistic‐regression (PLS–PLR) model and a hyperspectral biplot (HS biplot) as a visual tool for detecting the early stages of black Sigatoka disease.MethodsYoung (three‐month‐old) banana plants were inoculated with a conidia suspension of the black Sigatoka fungus (Pseudocercospora fijiensis). Selected infected and control plants were evaluated using a hyperspectral imaging system at wavelengths in the range of 386–1019 nm. PLS–PLR models were run on the hyperspectral data set. The prediction power was assessed using leave‐one‐out cross‐validation as well as external validation.ResultsThe PLS–PLR model was able to predict the presence of the disease with a 98% accuracy. The wavelengths with the highest contribution to the classification ranged from 577 to 651 nm and from 700 to 1019 nm.DiscussionPLS–PLR and HS biplot effectively estimated the presence of black Sigatoka disease at the early stages and can be used to graphically represent the relationship between groups of leaves and both visible and near‐infrared wavelengths.
Trial‐to‐Trial Variability in Electrodermal Activity to Odor in Autism
Authors: Haigh Sarah M. , Endevelt‐Shapira Yaara , Behrmann Marlene 
Published: August 2020

Abnormal trial‐to‐trial variability (TTV) has been identified as a key feature of neural processing that is related to increased symptom severity in autism. The majority of studies evaluating TTV have focused on cortical processing. However, identifying whether similar atypicalities are evident in the peripheral nervous system will help isolate perturbed mechanisms in autism. The current study focuses on TTV in responses from the peripheral nervous system, specifically from electrodermal activity (EDA). We analyzed previously collected EDA data from 17 adults with autism and 19 neurotypical controls who viewed faces while being simultaneously exposed to fear (fear‐induced sweat) and neutral odors. Average EDA peaks were significantly smaller and TTV was reduced in the autism group compared to controls, particularly during the fear odor condition. Amplitude and TTV were positively correlated in both groups, but the relationship was stronger in the control group. In addition, TTV was reduced in those with higher Autism Quotient scores but only for the individuals with autism. These findings confirm the existing results that atypical TTV is a key feature of autism and that it reflects symptom severity, although the smaller TTV in EDA contrasts with the previous findings of greater TTV in cortical responses. Identifying the relationship between cortical and peripheral TTV in autism is key for furthering our understanding of autism physiology.Lay SummaryWe compared the changes in electrodermal activity (EDA) to emotional faces over the course of repeated faces in adults with autism and their matched controls. The faces were accompanied by smelling fear‐inducing odors. We found smaller and less variable responses to the faces in autism when smelling fear odors, suggesting that the peripheral nervous system may be more rigid. These findings were exaggerated in those who had more severe autism‐related symptoms.
Phlorotannins as HIV Vpu inhibitors, an in silico virtual screening study of marine natural products
Authors: Langarizadeh Mohammad Amin , Abiri Ardavan , Ghasemshirazi Saeid , Foroutan Nazanin , Khodadadi Arash , Faghih‐Mirzaei Ehsan 
Published: August 2020

AbstractThe importance of new effective treatment methodologies for human immunodeficiency virus (HIV) is undeniable for the medical society. Viral protein U (Vpu), one of the disparaged accessory proteins of HIV, is responsible for the dissemination of viral particles, and HIV mutants lacking Vpu protein have remarkably reduced pathogenicity. Here, we explored the marine natural products to find the leading structures which can potentially inhibit the activity of Vpu in silico. To fulfill this goal, we set up a virtual screening based on molecular docking to evaluate the binding capacity of different marine products to Vpu. For validation, we used molecular dynamics simulation and monitored the root mean square deviation value and binding interactions. The results were intriguing when we realized that the hit compounds (phlorotannins) had previously been identified as reverse transcriptase and HIV protease inhibitors. This research inaugurates a new road to combat HIV by multifaceted mode of action of these marine natural products without putting the normal cells in jeopardy (with their safe toxicological profile).
Investigating the change in the photophysical properties of a trio of tetraphenylcyclopentadienone derivatives with varied groups on the aromatic rings in the 3‐ and 4‐positions
Authors: Orozco Arnoldo J. , Joachim Kole , Ruiz Henry D. , Fronczek Frank R. , Isovitsch Ralph 
Published: August 2020

AbstractOrganic compounds with electronic properties, such as a small band gap, are useful in areas ranging from organic field effect transistors to solar cells. Such organic compounds can possess conjugation and/or aromatic systems, with one example being tetraphenylcyclopentadienone and its derivatives. A trio of dramatically coloured tetraphenylcyclopentadienone derivatives with varied substituents on the aromatic rings in the 3‐ and 4‐positions were prepared. Their identities were confirmed using the usual methods, for example 1H nuclear magnetic resonance (NMR) spectroscopy, and their purity quantified using elemental analysis. The X‐ray crystal structure of compound 2 was determined. Its notable structural features involved the cyclopentadienone core with its distinct C−C and C=C bond lengths and its overall nonplanarity, both of which served to mitigate its antiaromatic nature. Chloroform solutions of compounds 2–4 exhibited absorption spectra with three absorption bands at approximately 250, 350, and 500 nm that were assigned to (π)→(π*) transitions. Computational chemistry methods assisted in assigning the observed transitions to a specific molecular orbital combination in the structures of 2–4. Emission in the red end of the visible spectrum (550–625 nm) was observed from chloroform solutions of all three of the prepared compounds.
Microscopic insight to specificity of metal ion cofactor in DNA cleavage by restriction endonuclease EcoRV
Authors: Mandal Sasthi Charan , Maganti Lakshmi , Mondal Manas , Chakrabarti Jaydeb 
Published: August 2020

AbstractRestriction endonucleases protect bacterial cells against bacteriophage infection by cleaving the incoming foreign DNA into fragments. In presence of Mg2+ ions, EcoRV is able to cleave the DNA but not in presence of Ca2+, although the protein binds to DNA in presence of both metal ions. We make an attempt to understand this difference using conformational thermodynamics. We calculate the changes in conformational free energy and entropy of conformational degrees of freedom, like DNA base pair steps and dihedral angles of protein residues in Mg2+(A)‐EcoRV‐DNA complex compared to Ca2+(S)‐EcoRV‐DNA complex using all‐atom molecular dynamics (MD) trajectories of the complexes. We find that despite conformational stability and order in both complexes, the individual degrees of freedom behave differently in the presence of two different metal ions. The base pairs in cleavage region are highly disordered in Ca2+(S)‐EcoRV‐DNA compared to Mg2+(A)‐EcoRV‐DNA. One of the acidic residues ASP90, coordinating to the metal ion in the vicinity of the cleavage site, is conformationally destabilized and disordered, while basic residue LYS92 gets conformational stability and order in Ca2+(S) bound complex than in Mg2+(A) bound complex. The enhanced fluctuations hinder placement of the metal ion in the vicinity of the scissile phosphate of DNA. Similar loss of conformational stability and order in the cleavage region is observed by the replacement of the metal ion. Considering the placement of the metal ion near scissile phosphate as requirement for cleavage action, our results suggest that the changes in conformational stability and order of the base pair steps and the protein residues lead to cofactor sensitivity of the enzyme. Our method based on fluctuations of microscopic conformational variables can be applied to understand enzyme activities in other protein‐DNA systems.
Strain engineering for high‐level 5‐aminolevulinic acid production in Escherichia coli
Authors: Miscevic Dragan , Mao Ju‐Yi , Kefale Teshager , Abedi Daryoush , Moo‐Young Murray , Perry Chou C. 
Published: August 2020

AbstractHerein, we report the development of a microbial bioprocess for high‐level production of 5‐aminolevulinic acid (5‐ALA), a valuable non‐proteinogenic amino acid with multiple applications in medical, agricultural, and food industries, using Escherichia coli as a cell factory. We first implemented the Shemin (i.e., C4) pathway for heterologous 5‐ALA biosynthesis in E. coli. To reduce, but not to abolish, the carbon flux toward essential tetrapyrrole/porphyrin biosynthesis, we applied clustered regularly interspersed short palindromic repeats interference (CRISPRi) to repress hemB expression, leading to extracellular 5‐ALA accumulation. We then applied metabolic engineering strategies to direct more dissimilated carbon flux toward the key precursor of succinyl‐CoA for enhanced 5‐ALA biosynthesis. Using these engineered E. coli strains for bioreactor cultivation, we successfully demonstrated high‐level 5‐ALA biosynthesis from glycerol (~30 g L−1) under both microaerobic and aerobic conditions, achieving up to 5.95 g L−1 (36.9% of the theoretical maximum yield) and 6.93 g L−1 (50.9% of the theoretical maximum yield) 5‐ALA, respectively. This study represents one of the most effective bio‐based production of 5‐ALA from a structurally unrelated carbon to date, highlighting the importance of integrated strain engineering and bioprocessing strategies to enhance bio‐based production.
Associations between apparent diffusion coefficient values and histopathological tissue alterations in myopathies
Authors: Meyer Hans‐Jonas , Schneider Ilka , Emmer Alexander , Kornhuber Malte , Surov Alexey 
Published: August 2020

AbstractObjectivesDiffusion‐weighted imaging (DWI) can reflect histopathologic changes in muscle disorders. The present study sought to elucidate possible associations between histopathology derived from muscle biopsies and DWI in myositis and other myopathies.MethodsNineteen patients (10 women, 52.6%) with a mean age 51.43 ± 19 years were included in this retrospective study. Apparent diffusion coefficients (ADC) were evaluated with a histogram approach of the biopsied muscle. The histopathology analysis included the scoring systems proposed by Tateyama et al., Fanin et al., Allenbach et al. and immunhistochemical stainings for MHC, CD68, CD8, and CD4.ResultsThere was a tendency that skewness was lowered with increasing Tateyama score, but it did not reach statistical significance (p = .14). No statistical differences for the other scores were identified. There was a tendency that kurtosis was higher in MHC negative stained patient compared to positive patients, but statistically significance was not reached (p = .07). ADC histogram parameters did not correlate with CD68 and CD8 positive stained cells. There was a trend for skewness to correlate with the amount of CD4‐positive cells (r = .57, p = .07).ConclusionThe present study could not identify statistical significant associations between DWI and histopathology in muscle diseases based upon a small patient sample. Presumably, the investigated histopathology scores are more specific for certain disease aspects, whereas ADC values reflect the whole cellularity of the investigated muscle, which might cause the negative results.
Identification of a novel prognostic DNA methylation signature for lung adenocarcinoma based on consensus clustering method
Authors: Cai Qidong , He Boxue , Xie Hui , Zhang Pengfei , Peng Xiong , Zhang Yuqian , Zhao Zhenyu , Wang Xiang 
Published: August 2020

AbstractAbnormal DNA methylation persists throughout carcinogenesis and cancer development. Hence, gene promoter methylation may act as a prognostic tool and provide new potential therapeutic targets for patients with lung adenocarcinoma (LUAD). In this study, to explore prognostic methylation signature, data regarding DNA methylation and RNA‐seq, and clinical data of patients with LUAD from the Cancer Genome Atlas database (TCGA) were downloaded. After data preprocessing, the methylation data were divided into training (N = 405) and test sets (N = 62). Then, patients in the training set were assigned to five subgroups based on their different methylation levels using the consensus clustering method. We comprehensively analyzed the survival information, methylation levels, and clinical variables, including American Joint Committee on Cancer (AJCC) stage, tumor‐node‐metastasis (TNM) staging, age, smoking history, and gender of these five groups. Subsequently, we identified a 16‐CpG prognostic signature and constructed a prognostic model, which was verified in the test set. Further analyses showed stable prognostic performance in the stratified cohorts. In conclusion, the new predictive DNA methylation signature proposed in this study may be used as an independent biomarker to assess the overall survival of LUAD patients and provide bioinformatics information for development of targeted therapy.
Maintenance rituximab in Veterans with follicular lymphoma
Authors: Halwani Ahmad S. , Rasmussen Kelli M. , Patil Vikas , Morreall Deborah , Li Catherine , Yong Christina , Burningham Zachary , Dawson Keith , Masaquel Anthony , Henderson Kevin , DeLong‐Sieg Elisha , Sauer Brian C. 
Published: August 2020

AbstractReal‐world practice patterns and clinical outcomes in patients with follicular lymphoma (FL), including the adoption of maintenance rituximab (MR) therapy in the United States (US), have been reported in few studies since the release of the National LymphoCare Study almost a decade ago. We analyzed data from the largest integrated healthcare system in the United States, the Veterans Health Administration (VHA), to identify rates of adoption and effectiveness of MR in FL patients after first‐line (1L) treatment. We identified previously untreated patients with FL in the VHA between 2006 and 2014 who achieved at least stable disease after chemoimmunotherapy or immunotherapy. Among these patients, those who initiated MR within 238 days of 1L composed the MR group, whereas those who did not were classified as the non‐MR group. We examined the effect of MR on progression‐free survival (PFS) and overall survival (OS). A total of 676 patients met our inclusion criteria, of whom 300 received MR. MR was associated with significant PFS (hazard ratio [HR]=0.55, P < .001) and OS (HR = 0.53, P = .005) compared to the non‐MR group, after adjusting by age, sex, ethnicity, geographic region, diagnosis period, stage, grade at diagnosis, hemoglobin, lactate dehydrogenase (LDH), Charlson comorbidity index (CCI), 1L treatment regimen, and response to 1L treatment. These results suggest that in FL patients who do not experience disease progression after 1L treatment in real‐world settings, MR is associated with a significant improvement in both PFS and OS. Maintenance therapy should be considered in FL patients who successfully complete and respond to 1L therapy.
Management and outcomes of coronary artery perforations treated with the block and deliver technique
Authors: Sanz Sanchez Jorge , Garbo Roberto , Gagnor Andrea , Oreglia Jacopo , Mazzarotto Pietro , Maurina Matteo , Regazzoli Damiano , Gasparini Gabriele L. 
Published: August 2020

AbstractObjectives and BackgroundCoronary artery perforation (CAP) is a potentially life‐threatening complication during percutaneous coronary interventions (PCI) and the best strategy for its management is yet to be proved. We aimed to analyze the safety, efficacy, and long‐term clinical outcomes of the block and deliver (BAD) technique, as only anecdotal cases are reported in literature.MethodsFrom January 2016 to January 2020, all consecutive patients treated with the BAD technique at five high‐volume centers in Italy were retrospectively identified.Results25 CAPs treated with the BAD technique were included. The most frequently perforated artery was the left anterior descending artery (32%) and spring‐coil wires with a hydrophilic coating were the most common culprit wires (68%). Mean sealing time was 46.9 ± 60.1 min, with no significant differences between CTO‐PCIs and non‐CTO PCIs (p = .921). Acute successful sealing of the CAP was achieved in 96% of the cases. Immediate cardiac tamponade occurred in 28% of patients, four during CTO PCI and three during non‐CTO PCI (p = .55). Two patients required pericardiocentesis during hospitalization, one patient developed acute kidney injury, and one patient underwent cardiac surgery due to severe mitral regurgitation. At 1‐year follow‐up no significant differences were observed between groups in terms of POCE (25 vs 25%, p = .628) and its individual components.ConclusionThe BAD technique proved to be effective for the management of CAP, showing high successful sealing rates. Rates of in‐hospital events and at 1‐year follow‐up did not significantly differ between patients suffering CAP during CTO revascularization or during non‐CTO PCI.
Size‐Dependent and Self‐Catalytic Gold@Prussian Blue Nanoparticles for the Electrochemical Detection of Hydrogen Peroxide
Authors: Zhang Minwei , Zhang Wenrui , Engelbrekt Christian , Hou Chengyi , Zhu Nan , Chi Qijin 
Published: August 2020

AbstractABSTRACT: Prussian blue (PB) nanoparticle (NP)‐based nanomaterials have become a subject of intense interest, because of their intriguing physical and chemical properties that differ from their bulk counterparts, leading to novel applications in electrocatalysis. However, the size effect of PB NPs on the electrocatalytic performance is still ambiguous and hinders further applications for the study of biomimetic sensors. In this work, a new approach to synthesize core‐shell Au@PB NPs is presented, using gold nanoparticles as catalysts for the fabrication of size‐controllable, highly stable, water‐soluble, biologically compatible and highly electrochemically active PB NPs. As a result, all sizes of Au@PB NPs display high electrochemical activity towards peroxidase biomimicry. Furthermore, the size effect of PB‐based electrocatalysis has been investigated, showing the best performance for 18 nm Au@PB NPs. This insight could be used for the design and application of PB‐based nanomaterials in biosensors.