bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Control of Spiroketal Formation in Rubromycin Polyketide Biosynthesis
Authors: Toplak Marina , Saleem‐Batcha Raspudin , Piel Jörn , Teufel Robin 
Published: October 2021

AbstractThe medically important bacterial aromatic polyketide natural products typically feature a planar, polycyclic core structure. An exception is found for the rubromycins, whose backbones are disrupted by a bisbenzannulated [5,6]‐spiroketal pharmacophore that was recently shown to be assembled by flavin‐dependent enzymes. In particular, a flavoprotein monooxygenase proved critical for the drastic oxidative rearrangement of a pentangular precursor and the installment of an intermediate [6,6]‐spiroketal moiety. Here we provide structural and mechanistic insights into the control of catalysis by this spiroketal synthase, which fulfills several important functions as reductase, monooxygenase, and presumably oxidase. The enzyme hereby tightly controls the redox state of the substrate to counteract shunt product formation, while also steering the cleavage of three carbon‐carbon bonds. Our work illustrates an exceptional strategy for the biosynthesis of stable chroman spiroketals.
Total Synthesis of Dolabriferol C by a Highly Stereoselective One‐Pot Coupling of a meso‐3,7‐Diketone with Two Chiral Aldehydes
Authors: Diddi Naveen , Ward Dale E. 
Published: October 2021

AbstractTotal synthesis of the noncontiguous polypropionate dolabriferol C was achieved by retro‐Claisen fragmentation of its putative contiguous precursor under mild conditions, thus establishing the former as a plausible isolation artifact. The precursor was prepared by a novel one‐pot three‐component bisaldol coupling of a meso (Z,Z)‐bisenolate (generated in situ from a 3,7‐diketone) with two enantioenriched aldehydes to set the absolute configuration of seven stereocenters in one step. The first aldol reaction proceeded with enantioselective desymmetrization of the bisenolate to produce an enantiomerically pure enolate–aldolate. Quenching at this stage enabled a streamlined synthesis of dolabriferol. Addition of a racemic aldehyde to the enolate–aldolate resulted in aldol coupling with kinetic resolution of the “matched” aldehyde; overall, a sequential enantiotopic‐group‐selective (SEGS) bisaldol reaction. Because the desired adduct results from the “mismatched” aldol reaction, use of enantioenriched aldehyde was required.
Residual levels and dietary risk assessment of bifenthrin and dinotefuran and its major metabolites in open wheat field conditions
Authors: Li Pengfei , Hu Jiye 
Published: October 2021

AbstractTo evaluate the residual levels of bifenthrin and dinotefuran, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) and high‐performance liquid chromatography–tandem mass spectrometry method for simultaneous detection of bifenthrin and dinotefuran and its major metabolites in wheat was developed and validated. Dietary risk assessments were further performed based on the relevant residual data from 12 wheat fields, toxicology data and dietary patterns. In wheat grain and straw, the recoveries of all analytes ranged from 77 to 102% with the relative standard deviation <9.7% and the limit of quantitation 0.05 mg kg−1. The highest terminal residue of bifenthrin in wheat grain was 0.069 mg kg−1 and dinotefuran was 0.34 mg kg−1. Residual concentrations of bifenthrin and dinotefuran decreased to <0.05 and 0.15 mg kg−1 at 21 days (pre‐harvest interval), respectively. The chronic risk quotient ranged from 6.4 to 62.7% and the acute risk quotient varied from 0.38 to 17.73%. The chronic and acute dietary risks caused by the terminal residues of the two insecticides were negligible for Chinese populations. The recommended pre‐harvest interval was proposed to ensure safe wheat consumption. These data could provide a scientific reference to establish the Chinese maximum residue limit of dinotefuran in wheat.
Does Machiavellianism meaningfully differ from psychopathy? It depends
Authors: Sharpe Brinkley M. , Collison Katherine L. , Lynam Donald R. , Miller Joshua D. 
Published: October 2021

AbstractMachiavellianism is a personality construct characterized by cynicism, callousness, and skillful manipulation of others to achieve personal gains. We review the Machiavellianism literature with a particular focus on its measurement alongside narcissism and psychopathy in the so‐called “Dark Triad” (DT). We discuss criticisms of Machiavellianism on the grounds of insufficient construct validity as well as its virtual indistinguishability from psychopathy when assessed by commonly used instruments. As a response to these criticisms, we offer the super‐short form of the Five Factor Machiavellianism Inventory (FFMI‐SSF) as an alternative. The goal of the present study was to evaluate the FFMI‐SSF in relation to psychopathy and basic personality traits (i.e., the Five Factor Model) and to compare it to widely used measures of the DT and psychopathy in a large undergraduate sample (n = 1004).
Quantitative Analysis of Bioactive Carbazole Alkaloids in Murraya koenigii (L.) from Six Different Climatic Zones of India Using UPLC/MS/MS and Their Principal Component Analysis
Authors: Nandan Shiv , Singh Sumit K. , Singh Pratibha , Bajpai Vikas , Mishra Ashwanee K. , Joshi Trapti , Mahar Rohit , Shukla Sanjeev K. , Mishra Dipak K. , Kanojiya Sanjeev 
Published: October 2021

AbstractMurraya koenigii (L.) Spreng (Curry leaf) is a commercially important medicinal plant in South Asia, containing therapeutically valuable carbazole alkaloids (CAs). Thus, the quantitative evaluation of these compounds from different climatic zones of India are an important aspect for quality assessment and economic isolation of targeted compounds from the plant. In this study, quantitative estimation of CAs among 34 Indian natural populations of M. koenigii was assessed using UPLC/MS/MS. The collected populations represent the humid subtropical, tropical wet & dry, tropical wet, semi‐arid, arid, and montane climatic zones of India. A total of 11 CAs viz. koenine‐I, murrayamine A, koenigine, koenimbidine, koenimbine, O‐methylmurrayamine A, girinimbine, mahanine, 8,8’’‐biskoenigine, isomahanimbine, and mahanimbine were quantified using multiple reaction monitoring (MRM) experiments within 5.0 min. The respective range for natural abundance of CAs were observed as 0.097–1.222, 0.092–5.014, 0.034–0.661, 0.010–1.673, 0.013–7.336, 0.010–0.310, 0.010–0.114, 0.049–5.288, 0.031–1.731, 0.491–3.791, and 0.492–5.399 mg/g in leaves of M. koenigii. The developed method shown linearity regression coefficient (r2>0.9995), LOD (0.003–0.248 ng/mL), LOQ (0.009–0.754 ng/mL), and the recovery was between 88.803–103.729 %. The bulk of these CAs were recorded in their highest concentrations in the humid subtropical zone, followed by the tropical wet & dry zones of India. Further, principal component analysis (PCA) was performed which differentiated the climatic zones according to the dominant and significant CAs contents within the populations. The study concludes that the method established is simple, rapid, with high sample throughput, and can be used as a tool for commercial purposes and quality control of M. koenigii.
Comparative evaluation of amino acid composition and protein profile of gliadin from different extraction protocols
Authors: Rani Monika , Siddiqi Raashid Ahmad , Sogi Dalbir Singh , Gill Balmeet Singh 
Published: October 2021

AbstractSignificance and backgroundGliadin is known to trigger the celiac disease or gluten sensitivity affecting around 70 million people globally. Its detection in early stages has become a controversial issue due to lack of efficient gliadin extraction procedures. The efficiency of gliadin extraction procedure is therefore an important critical step to the results of detection of gluten‐derived products from either rapid immunoreactivity assay kit or analytical mass analysis. Hence, four gliadin extraction procedures were investigated using six wheat cultivars and analyzed for their physiochemical analysis.FindingsThe relative proportion of ω‐gliadin, α/β‐, γ‐gliadin, HMW‐NG, and amino acid concentration of gliadin varied with the extraction protocol. The higher proportion of α/β‐, γ‐gliadin was found in Weiss extraction protocol (79.74%–88.62%) and lowest in Wallace (50.70%–58.91%). The ω‐gliadin was found to be significantly (p ≤ .05) highest in DuPont (9.78%–22.54%) and lowest in Weiss protocol (0.46%–1.04%). The region between 36 and 44 kDa showed well‐resolved bands in DuPont, while a dense mass in other extraction protocols. Amino acid score was found to be significantly (p ≤ .05) higher in DuPont (79.53–91.75 g/100 g), followed by Osborne (67.17–81.16 g/100 g), Wallace (68.54–77.58 g/100 g), and Weiss (60.97–79.16 g/100 g) extracted gliadin.ConclusionThe extraction protocol was found to influence the proportion of different protein fractions as well as amino acid concentration.Significance and noveltyThe insight obtained gives a better understanding of how the same protein behaves when extracted with different extraction protocols.
Drag Reduction Performance and Stability of an Organic Polymer, Surfactant, and Their Complexes
Authors: Abdulbari Hayder A. , Amir Rasidah 
Published: October 2021

AbstractLong‐chained polymeric drag‐reducing agents suffer from mechanical degradation when exposed to a high‐shearing environment during the transportation of liquids in turbulent flow mode. Improving the polymer's resistance to shear forces using chemical methods is time‐consuming and associated with high costs. The drag reduction performance and stability of xanthan gum polymer, cetyltrimethylammonium bromide surfactant, and their physically formed complexes were investigated using a high‐shear rotating‐disk apparatus. The results demonstrated that all the examined additives could act as effective drag‐reducing agents, and their complexes showed modified mechanical degradation and drag reduction performances.
Reflections on the intriguing occurrence of some recently isolated natural products as racemates and scalemic mixtures
Authors: Zask Arie , Ellestad George A. 
Published: October 2021

AbstractThis review continues our interest in the intriguing reports of a variety of new racemic natural products (at least 11 in the past 4 years). These include the polyphenolic racemate galewone, the polycyclic prenylated acylphloroglucinol garcinielliptone; variecolortide, a combination of an anthraquinone and a isochinulin‐type alkaloid; the isoindoline alkaloid irpexine, the new hybrid phenylproanoid asarone; colletopyandione an indolydenepyradione; the enantiomerically enriched (scalemic) neolignans, gardenifolins; and meroterpenoid pabmaragramin in addition to some marine lipids. We also present a recent biomimetic synthesis of the polyketide preuisolactone A; synthesis of the polyketide spiromamakone A, which also corrected the proposed structure of another metabolite as identical to spiromamakone A; and the melicolones A and B. The continuing reports of natural racemates provoke speculation as to their role in the producing organism.
Effects of early‐life exposure to dust mite allergen and endotoxin on the development of asthma and wheezing: The Japan Environment and Children's Study
Authors: Hasunuma Hideki , Yoda Yoshiko , Tokuda Narumi , Taniguchi Naoko , Takeshima Yasuhiro , Shima Masayuki ,   The Japan Environment and Children's Study (JECS) Group
Published: October 2021

AbstractBackgroundThe effects of early‐life exposure to house dust mite allergen and endotoxin on the development of asthma are unclear in the literature. We investigated the association of early‐life exposure (0–36 months old) to house dust mite allergen and endotoxin with asthma incidence.MethodsIn this novel, large‐scale, nationwide birth cohort study, 5017 participants were randomly selected from those who met the eligibility criteria. House dust was vacuum‐sampled from the children's mattresses within homes and assayed for the presence of dust mite allergen (Der 1) and endotoxin. The participants were classified into four quartiles (Q1–Q4) according to exposure levels. We defined the incidence of asthma and wheezing using questionnaires at 12, 24, and 36 months old. Odds ratios (ORs) of the incidence of asthma and wheezing by age in Der 1 and endotoxin exposure level were estimated using logistic regression.ResultsThe cumulative incidence rates of asthma and wheezing during 0–36 months were 10.4% and 38.1%, respectively. Significant ORs were observed in asthma onset during 12–24 months old, asthma onset during 24–36 months old, and wheezing onset during 0–12 months old in the Q4 Der 1 group. In the Q4 endotoxin group, significant positive associations between endotoxin exposure and asthma (OR 2.00, 95% confidence interval [CI]: 1.03–3.85) and wheezing (OR 1.78, 95% CI: 1.01–3.12) onset during 24–36 months old were found.ConclusionsOur results indicated that high levels of early‐life exposure to Der 1 and endotoxin in mattresses may be involved in the development of asthma.
A Patent Review on SARS Coronavirus Main Protease (3CLpro) Inhibitors
Authors: Chia C. S. Brian , Xu Weijun , Shuyi Ng Pearly 
Published: October 2021

AbstractThe severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemic is an unprecedented global health emergency causing more than 4.2 million fatalities as of 30 July 2021. Only three antiviral therapies have been approved or granted emergency use authorization by the FDA. The SARS‐CoV‐2 3CL protease (3CLpro) is deemed an attractive drug target as it plays an essential role in viral polyprotein processing and pathogenesis, although no inhibitors have been approved. This patent review discusses SARS coronavirus 3CLpro inhibitors that have been filed up to 30 July 2021, giving an overview on the types of inhibitors that have generated commercial interest, especially amongst drug companies. Insights into the common structural motifs required for active site binding is also discussed.
A reputation‐based RPL protocol to detect selective forwarding attack in Internet of Things
Authors: Patel Anshuman , Jinwala Devesh 
Published: October 2021

SummaryInternet of Things (IoT) is an internet of smart objects where smart objects communicate with each other. IoT objects are deployed in open medium with dynamic topology. Due lack of infrastructure and centralized management, IoT present serious vulnerabilities to security attacks. Therefore, security is an essential prerequisite for the real‐world deployment of IoT. In this work, we propose reputation‐based RPL protocol where reputation‐based mechanism is embedded into RPL protocol to enhance its capabilities against selective forwarding attack. Reputation is calculated by evaluating data forwarding behavior of IoT node. Data forwarding behavior of IoT node is evaluated by the difference between monitored actual packet loss and estimated normal loss. Calculated reputation value is considered in parent selection. Simulation results show that the proposed approach can accurately detect and isolate selective forwarding attack with improving data delivery ratio of the IoT network.
Does the legacy of historical thinning treatments foster resilience to bark beetle outbreaks in subalpine forests?
Authors: Morris Jenna E. , Buonanduci Michele S. , Agne Michelle C. , Battaglia Mike A. , Harvey Brian J. 
Published: October 2021

AbstractPromoting ecological resilience to increasing disturbance activity is a key management priority under warming climate. Across the Northern Hemisphere, tree mortality from widespread bark beetle outbreaks raises concerns for how forest management can foster resilience to future outbreaks. Density reduction (i.e., thinning) treatments can increase vigor of remaining trees, but the longevity of treatment efficacy for reducing susceptibility to future disturbance remains a key knowledge gap. Using one of the longest‐running replicated experiments in old‐growth subalpine forests, we measured stand structure following a recent (early 2000s) severe mountain pine beetle (MPB; Dendroctonus ponderosae) outbreak to examine the legacy of historical (1940s) thinning treatments on two components of resilience. We asked: ‘How did historical thinning intensity affect (1) tree‐scale survival probability and stand‐scale survival proportion (collectively “resistance” to outbreak) for susceptible trees (lodgepole pine [Pinus contorta] ≥ 12 cm diameter) and (2) post‐outbreak stand successional trajectories?’ Overall outbreak severity was high (MPB killed 59% of susceptible individuals and 78% of susceptible basal area), and historical thinning had little effect on tree‐scale and stand‐scale resistance. Tree‐scale survival probability decreased sharply with increasing tree diameter and did not differ from the control (uncut stands) in the historical thinning treatments. Stand‐scale proportion of surviving susceptible trees and basal area did not differ from the control in historically thinned stands, except for treatments that removed nearly all susceptible trees, in which survival proportion approximately doubled. Despite limited effects on resistance to MPB outbreak, the legacy of historical treatments shifted dominance from large‐diameter to small‐diameter lodgepole pine by the time of outbreak, resulting in historically thinned stands with ~2× greater post‐outbreak live basal area than control stands. MPB‐driven mortality of large‐diameter lodgepole pine in control stands and density‐dependent mortality of small‐diameter trees in historically thinned stands led to convergence in post‐outbreak live tree stand structure. One exception was the heaviest historical thinning treatments (59–77% basal area removed), for which sapling dominance of shade‐tolerant, unsusceptible conifers was lower than control stands. After six decades, thinning treatments have had minimal effect on resistance to bark beetle outbreaks, but leave persistent legacies in shaping post‐outbreak successional trajectories.
Sensitive periods during the development and expression of vertebrate sexual signals: A systematic review
Authors: McDermott Molly T. , Safran Rebecca J. 
Published: October 2021

AbstractMany sexually selected traits exhibit phenotypic plasticity. Despite a growing appreciation for the ecological context in which sexual selection occurs, and for the role of plasticity in shaping traits associated with local adaptation and divergence, there is an important gap in knowledge about the onset and duration of plasticity in sexual trait expression. Integrating this temporal dimension of plasticity into models of sexual selection informs our understanding of the information conveyed by sexual traits and our predictions related to trait evolution, and is critical in this time of unprecedented and rapid environmental change. We conducted a systematic review of 869 studies to ask how trait modalities (e.g., visual and chemical) relate to the onset and duration of plasticity in vertebrate sexual signals. We show that this literature is dominated by studies of coloration in birds and fish, and most studies take place during the breeding season. Where possible, we integrate results across studies to link physiology of specific trait modalities with the life stage (e.g., juvenile, breeding, or nonbreeding) during which plasticity occurs in well‐studied traits. Limitations of our review included a lack of replication in our dataset, which precluded formal analysis. We argue that the timing of trait plasticity, in addition to environmental context, is critical for determining whether and how various communication signals are associated with ecological context, because plasticity may be ongoing or occur at only one point in an individual's lifetime, and determining a fixed trajectory of trait expression. We advocate for careful consideration of the onset and duration of plasticity when analyzing how environmental variation affects sexual trait expression and associated evolutionary outcomes.
Benefits and harms of sodium‐glucose co‐transporter‐2 inhibitors (SGLT2‐I) and renin–angiotensin–aldosterone system inhibitors (RAAS‐I) versus SGLT2‐Is alone in patients with type 2 diabetes: A systematic review and meta‐analysis of randomized controlled trials
Authors: Seidu Samuel , Kunutsor Setor K , Topsever Pinar , Khunti Kamlesh 
Published: October 2021

AbstractIntroductionIt is uncertain if the combination of sodium‐glucose co‐transporter 2 inhibitors (SGLT2‐Is) and renin‐angiotensin‐aldosterone system inhibitors (RAAS‐Is) provides better cardio‐renal clinical outcomes in people with type 2 diabetes mellitus (T2DM) compared with SGLT2‐Is alone. Using a systematic review and meta‐analysis of randomized controlled trials (RCTs), we evaluated the efficacy and safety with respect to cardio‐renal outcomes of the combination of SGLT2 and RAAS inhibitors vs SGLT2‐Is in patients with T2DM.MethodsStudies were identified from MEDLINE, Embase, the Cochrane Library and search of bibliographies to May 2021. The Cochrane risk of bias tool was used to assess the risk of bias of each study. Study‐specific risk ratios (RRs) with 95% confidence intervals (CIs) were pooled. Quality of the evidence was assessed using GRADE.ResultsNine articles comprising 8 RCT evaluations (n = 34,551 participants) that compared SGLT2‐Is with placebo in patients with T2DM against a background of standard care and reported subgroup results for those treated with or without RAAS‐Is at baseline were included. No RCT specifically investigated the combination of SGLT2 and RAAS inhibitors compared with SGLT2‐Is alone. The RRs (95% CIs) for composite cardiovascular outcome and composite CVD death/heart failure hospitalization comparing SGLT2‐Is vs placebo in patients on RAAS‐Is were 0.93 (0.85–1.01) and 0.88 (0.76–1.02), respectively. The corresponding estimates for patients not on RAAS‐Is were 0.78 (0.65–0.93) and 0.73 (0.65–0.82), respectively. There was no evidence of interactions between RAAS‐I status and the effects of SGLT2‐Is for both outcomes. Single study results showed that SGLT2‐Is vs placebo reduced the risk of composite kidney outcome and cardiovascular death in patients with RAAS inhibition. The effect of SGLT2 inhibition vs placebo on kidney parameters, genital infections, volume depletion, hyperkalaemia, hypokalaemia, hypoglycaemia and other adverse events was similar in patients with or without RAAS inhibition. The quality of the evidence ranged from very low to moderate.ConclusionsAggregate published data suggest that the combination of SGLT2 and RAAS inhibitors in the treatment of patients with T2DM may be similar in efficacy and safety if not superior to SGLT2‐Is alone. Head‐to‐head comparisons of the two interventions are warranted to inform T2DM management. The use of SGLT2 inhibition as a first‐line therapy in T2DM or its early use in the prevention of renal deterioration and cardiovascular complications in addition to its glycaemic control deserves further study.