bluuebunny/crossref_metadata_2025 huggingface dataset:
The OTELO survey as a morphological probe. Last ten Gyr of galaxy evolution
Authors: Nadolny Jakub , Bongiovanni Ángel , Cepa Jordi , Cerviño Miguel , Pérez García Ana María , Pović Mirjana , Pérez Martínez Ricardo , Sánchez-Portal Miguel , de Diego José A. , Pintos-Castro Irene , Alfaro Emilio , Castañeda Héctor O. , Gallego Jesús , Jesús González J. , Ignacio González-Serrano J. , Lara-López Maritza A. , Padilla Torres Carmen P.
Published: January 2021

Context. The morphology of galaxies provide us with a unique tool for relating and understanding other physical properties and their changes over the course of cosmic time. It is only recently that we have been afforded access to a wealth of data for an unprecedented number galaxies thanks to large and deep surveys.

Aims. We present the morphological catalogue of the OTELO survey galaxies detected with the Hubble Space Telescope (HST)-ACS F814W images. We explore various methods applied in previous works to separate early-type (ET) and late-type (LT) galaxies classified via spectral energy distribution (SED) fittings using galaxy templates. Together with this article, we are releasing a catalogue containing the main morphological parameters in the F606W and F814W bands derived for more than 8000 sources.

Methods. The morphological analysis is based on the single-Sérsic profile fit. We used the GALAPAGOS2 software to provide multi-wavelength morphological parameters fitted simultaneously in two HST-ACS bands. The GALAPAGOS2 software detects, prepares guess values for GALFIT-M, and provides the best-fitting single-Sérsic model in both bands for each source. Stellar masses were estimated using synthetic rest-frame magnitudes recovered from SED fittings of galaxy templates. The morphological catalogue is complemented with concentration indexes from a separate SExtractor dual, high dynamical range mode.

Results. A total of 8812 sources were successfully fitted with single-Sérsic profiles. The analysis of a carefully selected sample of ∼3000 sources up to zphot = 2 is presented in this work, of which 873 sources were not detected in previous studies. We found no statistical evidence for the evolution of the low-mass end of mass–size relation for ET and LT since z = 2. Furthermore, we found a good agreement for the median size evolution for ET and LT galaxies, for a given stellar mass, with the data from the literature. Compared to previous works on faint field galaxies, we found similarities regarding their rest-frame colours as well as the Sérsic and concentration indices.
The far reaches of the β
Pictoris debris disk
Authors: Janson Markus , Brandeker Alexis , Olofsson Göran , Liseau René
Published: January 2021

The nearby young star β Pictoris hosts a rich and complex planetary system, with at least two giant planets and a nearly edge-on debris disk that contains several dynamical subpopulations of planetesimals. While the inner ranges of the debris disk have been studied extensively, less information is known about the outer, fainter parts of the disk. Here we present an analysis of archival FORS V -band imaging data from 2003–2004, which have previously not been explored scientifically because the halo substructure of the bright stellar point spread function is complex. Through a high-contrast scheme based on angular differential imaging, with a forward-modelling approach to mitigate self-subtraction, we produced the deepest imaging yet for the outer range of the β Pic disk, and extracted its morphological characteristics. A brightness asymmetry between the two arms of the edge-on disk, which was previously noted in the inner disk, is even more pronounced at larger angular separations, reaching a factor ~10 around 1000 AU. Approaching 2000 AU, the brighter arm is visible at a surface brightness of 27–28 mag arcsec−2. Much like for the brightness asymmetry, a tilt angle asymmetry exists between the two arms that becomes increasingly extreme at large separations. The outer tilt angle of 7.2 deg can only be explained if the outer disk is farther from an edge-on inclination than the inner disk, or if its dust has a stronger scattering anisotropy, or (most likely) both. The strong asymmetries imply the presence of a highly eccentric kinematic disk component, which may have been caused by a disruptive event thought to have taken place at a closer-in location in the disk.
Langzeitverläufe depressiver Symptomlast und deren
Prädiktoren bei stationärer, tiefenpsychologisch fundierter
Psychotherapie: Befunde der STOP-D-Studie
Authors: Seidler Daniel , Altmann Uwe , Schäfer Ralf , Jenett Dörte , Franz Matthias
Published: January 2021

Ziel der Studie Depressive Erkrankungen zählen zu den
häufigsten psychischen Symptombildern. Bei insgesamt
bestätigter Wirksamkeit stationärer und ambulanter
Psychotherapie werden in der Literatur verschiedene Verlaufsmuster in der
Behandlung depressionstypischer Symptome beschrieben. Ziel der vorliegenden
Studie war es, typische Langzeitverläufe stationärer,
tiefenpsychologisch fundierter Psychotherapie depressiver Erkrankungen zu
identifizieren. Ferner sollten Prädiktoren für
unterschiedliche Verläufe ermittelt werden, um möglichst
früh Non-Responder zu erkennen und Behandlungsangebote differenziert
modifizieren zu können.

Methode Die Daten der naturalistischen Multizenterstudie STOP-D wurden
in 15 bundesdeutschen Psychosomatischen Klinikabteilungen mit primär
tiefenpsychologisch fundiertem Behandlungskonzept erhoben. Die Stichprobe
umfasste N=432 Patientinnen (Frauen, Alter 25–45 Jahren) mit
depressionstypischer Beeinträchtigung. Die Langzeitverläufe
wurden mittels Latent State Modell und einer Latent Class Analysis
identifiziert, potentielle Verlaufsprädiktoren wurden
regressionsanalytisch modelliert.

Ergebnisse Es wurde 3 Langzeitverläufe identifiziert:
Patientinnen, welche in bedeutendem Maße von der Behandlung
profitierten und deren Symptomrückgang sich auch in einer
6-Monats-Katamnese stabil zeigte (Responder, 76,9%), Patientinnen
ohne bedeutsamen Symptomrückgang während der Behandlung und
in der Katamnese (Non-Responder, 18,8%) sowie Patientinnen mit
signifikantem Symptomrückgang und Anstieg der Symptomatik im
Katamnesezeitraum (Rückfällige, 4,4%).
Prädiktor für den Langzeitverlauf der
Rückfälligen war die Ausprägung depressiver Symptome
zu Behandlungsbeginn. Non-Responder unterschieden sich gegenüber
Respondern durch häufigere psychosomatische Vorbehandlungen.

Diskussion Zukünftige Untersuchungen sollten u. a. bei
Rückfälligen prüfen, ob Rückfälle
durch die Symptomatik, die Behandlung oder das soziale Umfeld des Patienten
erklärt werden können. Bei Non-Respondern stellt sich vor
dem Hintergrund häufigerer, bereits wenig erfolgreicher
Vorbehandlungen die Frage, ob für diese Patienten ein anderes oder
modifiziertes Therapieangebot erwogen werden sollte.

Schlussfolgerung In der Literatur berichtete Langzeitverläufe
lassen sich teilweise bestätigen. Auch festigen sich Hinweise auf
einen Einfluss der initialen Belastungsschwere depressionstypischer
Symptomlast auf das Behandlungsergebnis im Verlauf. Zu untersuchen
wäre, wie Behandlungssettings entsprechend modifiziert werden
können.
Prävalenz, Kosten der Versorgung und Formen des dialysepflichtigen chronischen Nierenversagens in Deutschland: Vergleich der Dialyseversorgung innerhalb und außerhalb stationärer Pflegeeinrichtungen
Authors: Häckl Dennis , Kossack Nils , Schoenfelder Tonio
Published: January 2021

Ziel der Studie Für die Wohnbevölkerung Deutschlands stehen keine aktuellen Daten zur Prävalenz des chronischen Nierenversagens und den Versorgungskosten der Dialyse zur Verfügung. Das Ziel dieser Studie war die Erhebung der Prävalenz des dialysepflichtigen chronischen Nierenversagens und der Versorgungskosten der dialysepflichtigen Patienten sowie die Analyse von Unterschieden zwischen dialysepflichtigen Patienten in und außerhalb von stationären Pflegeeinrichtungen.

Methodik Analysiert wurden Abrechnungsdaten von gesetzlichen Krankenkassen aus der WIG2-Forschungsdatenbank, die rund 4,5 Mio. anonymisierte Versicherte enthält. Eingeschlossen wurden Patienten aller Altersgruppen, die 2017 aufgrund eines chronischen Nierenversagens eine ambulante Dialyse (EBM-Ziffer 13602) erhielten. Es erfolgte eine Hochrechnung identifizierter Versicherter für die GKV und BRD mit amtlichen Statistiken. Patienten, die in und außerhalb von stationären Pflegeeinrichtungen wohnhaft waren, wurden hinsichtlich Komorbiditäten, Leistungsinanspruchnahme und Kosten verglichen.

Ergebnisse Für 2017 wurden 87 255 Dialysepflichtige in der GKV (≙1 054 Personen/1 Mio. Einwohner, pmp) und 100.202 für die Wohnbevölkerung Deutschlands (≙1210 pmp) ermittelt. In stationären Pflegeeinrichtungen lebten rund 8% der Dialysepflichtigen (7676 Patienten). Bis 2040 ist von einem Anstieg Dialysepflichtiger von 20–23% auf ca. 120 000–123 000 zu rechnen und für Dialysepflichtige in stationären Pflegeeinrichtungen von ca. 37–44% auf ca. 10 500–11 000. Bei fast allen Dialysepflichtigen kommt die Hämodialyse zum Einsatz, die Peritonealdialyse wird kaum genutzt. Die durchschnittlichen jährlichen Versorgungskosten für dialysepflichtige Patienten, die nicht in einer Pflegeeinrichtung leben, betragen 53 996 und 57 205 € für solche in stationärer Pflege. Hieraus ergeben sich jährliche Versorgungskosten für die GKV von rund 4,73 Mrd. €.

Schlussfolgerung In dieser Studie wurde die Prävalenz des chronischen Nierenversagens für Deutschland auf einer aktuellen Datengrundlage berechnet. Die Ergebnisse bewegen sich im Rahmen von Daten anderer europäischer Länder. Es wird ein beträchtlicher Anstieg der Dialysepflichtigen bis 2040 prognostiziert, insbesondere für jene die im Heim leben. Hierdurch ist mit einer weiteren Steigerung der Versorgungskosten zu rechnen. Die häufigste Dialyseform ist die Hämodialyse, bei Patienten sowohl innerhalb als auch außerhalb stationärer Pflegeeinrichtungen, die Peritonealdialyse wird hingegen in nur geringem Maße eingesetzt.
Optimization and Evaluation of Self-nanoemulsifying Drug Delivery System for Enhanced Bioavailability of Plumbagin
Authors: Kamble Pavan Ram , Shaikh Karimunnisa Sameer
Published: January 2021

Plumbagin, a potential bioactive lipophilic molecule, possesses limited solubility and low oral bioavailability. The purpose of the present study was to examine the potential of the self-nanoemulsifying drug delivery system for improving solubility and oral bioavailability of plumbagin. The self-nanoemulsifying drug delivery system was formulated from Capmul MCM (oil), Tween 20 (surfactant), and propylene glycol (cosurfactant). Central composite design was employed as statistical tool to optimize the formulation variables, X1 (oil) and X2 (surfactant: co-surfactant mixture ratio), of the self-nanoemulsifying drug delivery system. The responses studied were droplet size, self-emulsification time, % of drug release in 15 min, and equilibrium solubility. The optimized liquid self-nanoemulsifying drug delivery system was adsorbed on Neusilin US2 and characterized for flow properties, X-ray diffractometry, differential scanning calorimetry, in
vitro dissolution, in vivo anti-inflammatory activity, and bioavailability study in Wistar rats, as well as ex vivo permeation study. The droplet size, polydispersity index, self-emulsification time, and equilibrium solubility of the optimized formulation were 58.500 ± 1.170 nm, 0.228 ± 0.012, 17.660 ± 1.520 s, and 34.180 ± 1.380 mg/mL, respectively. Its zeta potential, transmittance value, and cloud point were − 28.200 ± 1.200 mV, 99.200% ± 0.600, and 90 °C, respectively. Drug release was found to be 93.320% ± 1.090. In vivo anti-inflammatory study confirmed more enhanced activity from the self-nanoemulsifying drug delivery system than with pure plumbagin. Pharmacokinetic study in rats revealed that solid self-nanoemulsifying drug delivery system had 4.49-fold higher bioavailability than pure plumbagin. Ex vivo permeation study demonstrated 1.75-fold increased intestinal permeability of the self-nanoemulsifying drug delivery system than
pure plumbagin. The developed self-nanoemulsifying drug delivery system is a useful solid platform for improving solubility and oral bioavailability of plumbagin.
S2k-Leitlinie – Empfehlungen zur stationären Therapie von Patienten mit COVID-19
Authors: Kluge S. , Janssens U. , Welte T. , Weber-Carstens S. , Schälte G. , Spinner C. D. , Malin J. J. , Gastmeier P. , Langer F. , Wepler M. , Westhoff M. , Pfeifer M. , Rabe K. F. , Hoffmann F. , Böttiger B. W. , Weinmann-Menke J. , Kersten A. , Berlit P. , Haase R. , Marx G. , Karagiannidis C.
Published: January 2021

Seit Dezember 2019 verbreitet sich das neuartige Coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome – Corona Virus-2) rasch im Sinne einer weltweiten Pandemie. Dies stellt Kliniker und Krankenhäuser vor große Herausforderungen und belastet die Gesundheitssysteme vieler Länder in einem nie dagewesenen Ausmaß. Die Mehrheit der Patienten mit Coronavirus Disease 2019 (COVID-19) zeigt lediglich milde Symptome wie Husten und Fieber. Allerdings benötigen etwa 8 % eine stationäre Behandlung. Der frühzeitigen Klärung, ob eine stationäre und ggfs. intensivmedizinische Behandlung medizinisch sinnvoll und vom Patienten gewollt ist, kommt in der Pandemie eine besondere Bedeutung zu. Die akute hypoxämische respiratorische Insuffizienz mit Dyspnoe und hoher Atemfrequenz (> 30/min) führt i. d. R. zur Aufnahme auf die Intensivstation. Oft finden sich dann bereits bilaterale pulmonale Infiltrate/Konsolidierungen oder auch Lungenembolien in der Bildgebung. Im weiteren Verlauf entwickeln einige dieser Patienten ein akutes Lungenversagen (Acute Respiratory Distress Syndrome; ARDS). Eine Sterblichkeitsreduktion einer verfügbaren medikamentösen Therapie bei schwerer COVID-19-Erkrankung ist bisher lediglich für Dexamethason in randomisiert, kontrollierten Studien nachgewiesen. Das Hauptziel der supportiven Therapie besteht in der Sicherstellung einer ausreichenden Oxygenierung. Die invasive Beatmung und wiederholte Bauchlagerung sind dabei wichtige Elemente in der Behandlung von schwer hypoxämischen COVID-19-Patienten. Die strikte Einhaltung der Basishygiene, einschließlich der Händehygiene, sowie das korrekte Tragen von adäquater persönlicher Schutzausrüstung sind im Umgang mit den Patienten unabdingbar. Medizinisch notwendige Handlungen am Patienten, die zur Aerosolbildung führen könnten, sollten mit äußerster Sorgfalt und Vorbereitung durchgeführt werden.
Comparison of Different Clinical Prognostic Scores in Patients with Pulmonary Embolism and Active Cancer
Authors: Li Xiaoqian , Hu Yuehong , Lin Ping , Zhang Jiarui , Tang Yongjiang , Yi Qun , Liang Zong'an , Zhou Haixia , Wang Maoyun
Published: January 2021

Objective This article aimed to validate and compare the prognostic performance of generic scores (Pulmonary Embolism Severity Index [PESI] and Hestia) and cancer-specific pulmonary embolism (PE)/venous thromboembolism (VTE) scales (Registro Informatizado de la Enfermedad TromboEmbólica [RIETE], POMPE-C, and modified Ottawa) in PE patients with active cancer.

Methods A retrospective study was conducted among 460 patients with PE and active cancer. The primary outcome was 30-day overall mortality. Secondary outcomes were 30-day PE-related death and overall adverse outcomes. The prognostic accuracy of clinical scores was determined using receiver operating characteristic (ROC) curve analysis.

Results Within 30 days, 18.0% of patients died, 2.0% suffered major bleeding, and 0.2% presented recurrence of VTE. All scales showed a high area under the ROC curve (AUC) for predicting 30-day overall mortality except modified Ottawa (0.74 [0.70–0.78] for PESI, Hestia, and RIETE; 0.78 (0.74–0.81) for POMPE-C; 0.64 (0.59–0.68) for modified Ottawa]. PESI divided the least patients (9.1%) into low risk, followed by modified Ottawa (17.0%). Hestia stratified the most patients (65.4%) as low risk. But overall mortality of low-risk patients based on these three scales is high (>5%). RIETE and POMPE-C both classified 30.9% of patients as low risk, and low-risk patients stratified by these two scales presented a low overall mortality (1.4 and 3.5%). Similar predictive performance was found for 30-day PE-related death and overall adverse outcomes in these scores.

Conclusion Cancer-specific PE prognostic scores (RIETE and POMPE-C) performed better than generic scales (PESI and Hestia) and a cancer-specific VTE prognostic scale (modified Ottawa) in identifying low-risk PE patients with active cancer who may be suitable for outpatient treatment.
Transfusion with Cryoprecipitate for Very Low Fibrinogen Levels Does Not Affect Bleeding or Survival in Critically Ill Cirrhosis Patients
Authors: Budnick Isadore M. , Davis Jessica P.E. , Sundararaghavan Anirudh , Konkol Samuel B. , Lau Chelsea E. , Alsobrooks James P. , Stotts Matthew J. , Intagliata Nicolas M. , Lisman Ton , Northup Patrick G.
Published: January 2021

Background Fibrinogen (FIB) levels less than 150 mg/dL have been associated with increased rates of bleeding and lower survival in critically ill cirrhosis patients.

Objective We aimed to determine if treatment with cryoprecipitate (CRYO) for low FIB levels is associated with bleeding outcomes or survival.

Methods A total of 237 cirrhosis patients admitted to an intensive care unit at a tertiary care liver transplant center with initial FIB levels less than 150 mg/dL were retrospectively assessed for CRYO transfusion, bleeding events, and survival outcomes.

Results The mean MELD score was 27.2 (95% confidence interval [CI]: 26.0–28.3) and CLIF-C acute on chronic liver failure score was 53.4 (51.9–54.8). Ninety-nine (41.8%) were admitted for acute bleeding and the remainder were admitted for nonbleeding illnesses. FIB level on admission correlated strongly with disease severity. After adjusting for disease severity, FIB on admission was not an independent predictor of 30-day survival (hazard ratio [HR]: 0.99, 95% CI: 0.99–1.01, p = 0.68). CRYO transfusion increased FIB levels but had no independent effect on mortality or bleeding complications (HR: 1.10, 95% CI: 0.72–1.70, p = 0.65).

Conclusion In cirrhosis patients with critical illness, low FIB levels on presentation reflect severity of illness but are not independently associated with 30-day mortality. Treatment of low FIB with CRYO also does not affect survival or bleeding complications, suggesting FIB is an additional marker of severity of illness but is not itself a direct factor in the pathophysiology of bleeding in critically ill cirrhosis patients.
Preoperative Factors Affecting the Patient-Reported Outcome Measures following Total Knee Replacement: Socioeconomic Factors and Preoperative OKS Have a Clinically Meaningful Effect
Authors: Demetriou Charis , Webb Jeremy , Sedgwick Philip , Afzal Irrum , Field Richard , Kader Deiary
Published: January 2021

The Oxford Knee Score (OKS) is a patient-reported outcome questionnaire typically used to assess function and pain in patients undergoing total knee replacement (TKR). However, research is inconclusive as to which preoperative factors are important in explaining variation in outcome following TKR. The operative records of 12,709 patients who underwent primary TKR over a 9-year period were analyzed. The following variables were collected for each patient: age, sex, body mass index (BMI), Index of Multiple Deprivation decile rank, side of operation, diagnosis, the American Society of Anaesthesiologists (ASA) grade, preoperative OKS, EQ-5D index score, EuroQol visual analog scale (EQ-VAS) score, the postoperative OKS at 1 and 2 years. Generalized linear regression models were performed at 1 and 2 years to investigate the effect of the preoperative variables on the postoperative OKS. The effect of age, sex, BMI, Index of Multiple Deprivation decile rank, diagnosis, ASA grade, preoperative OKS, EuroQoL five-dimensional (EQ-5D) index score, and EQ-VAS score were all statistically significant in explaining the variation in OKS at 1 and 2 years postoperatively, with critical level of significance of 0.05 (5%). Being male aged 60 to 69 years of normal BMI, ASA grade I (fit and healthy), living in an affluent area, not reporting preoperative anxiety/depression, were associated with an enhanced mean postoperative OKS at both 1 and 2 years. When adjusted for potential confounding, age of 60–69 years, male sex, normal BMI, lower ASA grade, higher Index of Multiple Deprivation and higher pre-operative EQ-5D, EQ-VAS and OKS were identified as factors that resulted in higher post-operative OKS after primary TKR.
Tibial Cut Accuracy in Mechanically Aligned Total Knee Arthroplasty Using Extensor Hallucis Longus Tendon to Determine Extramedullary Tibial Guide Position
Authors: Besa Pablo , Vega Rafael , Ledermann Gerardo , Calvo Claudio , Angulo Manuela , Lira María Jesús , Vidal Catalina , Orrego Mario , Irribarra Luis , Espinosa Julio , Vial Raimundo , Irarrázaval Sebastián
Published: January 2021

This study aimed to determine the tibial cut (TC) accuracy using extensor hallucis longus (EHL) tendon as an anatomical landmark to position the total knee arthroplasty (TKA) extramedullary tibial guide (EMTG), and its impact on the TKA mechanical alignment (MA). We retrospectively studied 96 TKA, performed by a single surgeon, using a femoral tailored intramedullary guide technique. Seventeen were prior to the use of the EHL and 79 used the EHL tendon to position the EMTG. We analyzed preoperative and postoperative standing total lower extremity radiographs to determine the tibial component angle (TCA) and the correction in MA, comparing pre-EHL use and post-EHL technique incorporation. Mean TCA was 88.89 degrees and postoperative MA was neutral in 81% of patients. Pre- and postoperative MAs were not correlated. As a conclusion of this study, using the EHL provides a safe and easy way to determine the position of EMTG.
2.2 Samarium-Mediated Reductions
Authors: Flowers R. A. , Chciuk T. V. , Bartulovich C. O.
Published: January 2021

Samarium(II)-based reductants have been shown to be a group of very powerful reagents whose reactivity can be tuned significantly by the use of additives. The use of additives has been shown to greatly impact the rate, diastereoselectivity, chemoselectivity, and mechanism by which these reactions proceed, making these systems extremely useful and versatile. These reagents have been shown to promote several reactions including reductions of a range of functional groups and a variety of carbon–carbon bond forming reactions. More recently, initial work has demonstrated catalytic reactions of samarium(II)-based reductants. This chapter focuses on the chemistry of samarium diiodide (SmI2) and a few other samarium(II)-based reductants, with examples of the reactions they promote, both with and without the use of additives. Additionally, recent work on the mechanistic understanding of catalytic reactions using terminal reductants and a novel example of an approach employing radical relay that negates the use of a terminal reductant are presented.
2.3 Single-Electron-Transfer Oxidation and Reduction Involving Metal Complexes other than Samarium
Authors: Cormier M. , Goddard J.-P.
Published: January 2021

Recent advances in the field of radical organic chemistry involving single-electron transfer (SET) are highlighted in this chapter. The focus is on processes between organic molecules and metal complexes that facilitate the creation of challenging covalent bonds. A selection of oxidation and reduction reactions is reported, with special attention paid to enantioselective reactions. Mechanistic discussions are also provided.
2.4 Redox-Active Ligands in Catalysis for Single-Electron-Transfer Processes
Authors: Ren Y. , Das A. , Hessin C. , Desage-El Murr M.
Published: January 2021

Redox-active ligands are well known for their ability to stabilize electronic density on their scaffolds, and coordination complexes with such ligands are often stable, open-shell species. This property can be used as a means to favor single-electron transfer (SET) with external sources and devise catalytic radical manifolds. This chapter highlights selected representative reactions resulting in efficient and broad-scope catalytic methodologies. It covers nitrene and carbene radical reactivity, as well as radical trifluoromethylation.
2.6 Generation of Carbon-Centered Radicals by Photochemical Methods
Authors: Fagnoni M. , Ravelli D. , Protti S.
Published: January 2021

A selection of the recent literature describing the light-driven generation and subsequent exploitation of carbon-centered radicals for synthetic purposes is presented in this chapter. The aim is to showcase to organic (photo)chemistry practitioners the impressive potential of photocatalytic and photochemical strategies in terms of versatility, efficiency, and sustainability.
2.8 Selective Radical Fluorinations
Authors: Bolduc T. G. , Thomson B. , Sammis G. M.
Published: January 2021

Fluorine atoms are found in numerous industrially relevant materials, including pharmaceuticals, agrochemicals, and plastics. In the pharmaceutical industry alone, more than 20% of all therapeutics and a majority of the top-grossing drugs contain fluorine. The ubiquity of fluorinated compounds in industry has necessitated the development of new methods for selective fluorination. Historically, selective fluorination has relied upon electrophilic or nucleophilic processes. Recent breakthroughs in the discovery of mild radical fluorine-transfer reagents have led to a renaissance in selective radical fluorinations. This review provides a brief overview of the known fluorine-transfer reagents, including molecular fluorine, hypofluorites, xenon difluoride, electrophilic N–F reagents, and metal–F reagents. A survey of a range of radical fluorination reactions is covered, including fluorodecarboxylation, fluorination of alkenes, fluorination of boronic acid derivatives, C—H activation and fluorination, C—C activation and fluorination, deoxyfluorination, and halogen-exchange reactions. This review primarily focuses on advances in the last ten years, with an emphasis on the most practical methods.
2.9 Electrochemical Organic Synthesis via Radical Species
Authors: Mitsudo K. , Suga S.
Published: January 2021

An electrochemical single-electron-transfer reaction is a promising method to generate reactive radical species in organic synthesis. One-electron oxidation of a neutral compound gives a radical cation, which usually breaks down into a radical and a cationic species; conversely, one-electron reduction of a neutral compound affords a radical anion, which forms a radical and an anionic species. The radical species generated in this way can be used for a variety of transformations. In this chapter, selected recent electrochemical transformations that involve electrogenerated radical species are collected and described.
2.10 Radical Chemistry in Flow
Authors: Sumino S. , Fukuyama T. , Ryu I.
Published: January 2021

The past two decades have witnessed a rapid growth in flow-based organic synthesis and synthesis involving radical reactions in flow systems is no exception. Flow microreactors have large surface-to-volume ratios that become available by the employment of tiny channels, and this allows radical reactions to occur with efficient heat transfer and diffusion. Flow photomicroreactors with thin, glass-made channels allow for efficient light penetration, which enables highly efficient photo-radical reactions. This chapter highlights recent advances in both thermal and photo-induced radical reactions, which have achieved increased efficiency by using flow reaction systems.
2.11 Radical–Radical Cross-Coupling Reactions
Authors: Zhou M. , Qin T.
Published: January 2021

Due to nearly diffusion-limited radical–radical coupling, synthetically useful, selective radical–radical cross-coupling reactions remain challenging. However, different radical lifetimes and various radical initiation approaches now provide the possibility for radical–radical cross-coupling. In this chapter, recent advances in radical–radical cross-coupling reactions are described. In the first part, a basic kinetic phenomenon called the persistent radical effect is briefly reviewed and explained. The remainder of the chapter presents a series of case studies, illustrating several types of radical–radical cross couplings in a variety of disparate settings.
2.1 Organic Electron Donors in Electron-Transfer Reactions
Authors: Clark K. F. , Dimitrova D. , Murphy J. A.
Published: January 2021

The field of organic electron donors is large and diverse, both in terms of the structures of the donors and the structures of the acceptors. In the past 15 years, organic donors have been developed that show remarkable strength, with ground-state or excited-state oxidation potentials rivalling even the most reactive metals. At the other end of the scale of reactivity, highly reactive oxidizing agents are now available upon photoactivation of a number of organic structures. The first part of this chapter reviews organic electron donors that are based upon an alkene that is activated by strongly electron-releasing substituents; these donors can be active in the ground and/or excited states. The chapter also covers anionic organic donors that emerged in the field of SRN1 and base-induced homolytic aromatic substitution (BHAS) reactions, as well as substrate-based anionic donors including borates and silicates. The use of photoexcited organic dyes as electron donors is described and, finally, some of the recent research with very weak organic donors is highlighted.
IPEM topical report: guidance on the use of MRI for external beam radiotherapy treatment planning
*
Authors: Speight Richard , Dubec Michael , Eccles Cynthia L , George Ben , Henry Ann , Herbert Trina , Johnstone Robert I , Liney Gary P , McCallum Hazel , Schmidt Maria A
Published: January 2021

This document gives guidance for multidisciplinary teams within institutions setting up and using an MRI-guided radiotherapy (RT) treatment planning service. It has been written by a multidisciplinary working group from the Institute of Physics and Engineering in Medicine (IPEM). Guidance has come from the experience of the institutions represented in the IPEM working group, in consultation with other institutions, and where appropriate references are given for any relevant legislation, other guidance documentation and information in the literature. Guidance is only given for MRI acquired for external beam RT treatment planning in a CT-based workflow, i.e. when MRI is acquired and registered to CT with the purpose of aiding delineation of target or organ at risk volumes. MRI use for treatment response assessment, MRI-only RT and other RT treatment types such as brachytherapy and gamma radiosurgery are not considered within the scope of this document. The aim was to produce guidance that will be useful for institutions who are setting up and using a dedicated MR scanner for RT (referred to as an MR-sim) and those who will have limited time on an MR scanner potentially managed outside of the RT department, often by radiology. Although not specifically covered in this document, there is an increase in the use of hybrid MRI-linac systems worldwide and brief comments are included to highlight any crossover with the early implementation of this technology. In this document, advice is given on introducing a RT workload onto a non-RT-dedicated MR scanner, as well as planning for installation of an MR scanner dedicated for RT. Next, practical guidance is given on the following, in the context of RT planning: training and education for all staff working in and around an MR scanner; RT patient set-up on an MR scanner; MRI sequence optimisation for RT purposes; commissioning and quality assurance (QA) to be performed on an MR scanner; and MRI to CT registration, including commissioning and QA.
Superconducting gap ratio from strange metal phase in the absence of quasiparticles
Authors: Cai Wenhe , Ge Xian-Hui
Published: January 2021

A lattice model for strongly interacting electrons motivated by a rank-3 tensor model provides a tool for understanding the pairing mechanism of high-temperature superconductivity. This Sachdev–Ye–Kitaev-like model describes the strange metal phase in the cuprate high temperature superconductors. Our calculation indicates that the superconducting gap ratio in this model is higher than the ratio in the BCS theory due to the coupling term and the spin operator. Under certain conditions, the ratio also agrees with the BCS theory. Our results relate to the case of strong coupling, so it may pave the way to gaining insight into the cuprate high temperature superconductors.
Stratified Control Strategy of Vehicle Longitudinal Active Collision Avoidance
Authors: Zhang Kaimei , Liu Wenjing , Li Jiuru , Zhang Lei
Published: January 2021

In order to improve the safety and real-time performance of vehicle longitudinal active collision avoidance, a layered collision avoidance control method based on warning value, standard collision time safety model TTC and fuzzy PID is proposed in this paper. Based on the collision time safety model, the upper controller obtains the braking deceleration of the vehicle according to the relative speed and relative displacement of the obstacle in front. The lower controller is based on fuzzy PID, according to the brake deceleration speed of the upper vehicle, by controlling the pressure of the brake master cylinder of the vehicle, the control of vehicle speed is realized. Finally, using the CarSim/Simulink co-simulation platform, and taking the straight-line working condition as an example, the collision avoidance effect of the controlled vehicle under different speeds was simulated and verified. The results show that the upper controller can afford the appropriate speed of collision avoidance and deceleration according to the reference information, and the lower controller can adjust the brake deceleration speed according to the fuzzy PID, so as to realize the vehicle braking pressure, meet the requirements of longitudinal active collision avoidance.
Research on the Impact of Internet Consumer Credit on Hunan Residents’ Consumption Structure
Authors: Zhang Ying , Luo Jinjia
Published: January 2021

The escalating market demand of local residents makes the consumption a booster of the growth of China’s economy. Mainstream consumers began to choose Internet credit as their daily tool for smoothing out consumption. The consumption structure has also changed with the development of the Internet credit. In order to explore how Internet credits changes the residents’ consumption structure, this article selects the panel data of counties (districts) in Hunan Province from 2012 to 2018 for empirical research, uses the relevant indicators of Peking University Digital Inclusive Financial Index to construct Hunan Internet Consumer Credit Development Index, applies the fixed effect model (FE) and systematic GMM regression separately to analyse the impact of the Internet Consumer Credit on the consumption structure of residents, and then further compares the difference in the impact on different income levels. The results show that Internet consumer credit has promoted the upgrading of the consumption structure of residents in Hunan Province, and the improvement of the consumption structure of low-income residents is more significant.
Software and hardware co-simulation verification platform for navigation SoC
Authors: Qi Dan , Chen Mo , Zhang Shaozhen , Cheng Dan , Mu Jun
Published: January 2021

This paper proposes a software and hardware co-simulation verification platform suitable for satellite navigation SoC chips. The specific implementation scheme is described, and the final simulation results are given. Software simulation is written in c and assembly language, using a complete software compilation and debugging tool chain, hardware simulation is built based on verification methodology, SoC design code is written by verilog, and the software and hardware are coordinated through the VCS compiler to achieve information interaction, and then a universal simulation platform with fast speed, high authenticity and convenient debugging is realized. The simulation results show that the navigation SoC chip functions correctly.
Teaching Cases Analysis of Integration of Electromechanical Control of Linkage Mechanism
Authors: He Chaoming , Luo Yalin , Liu Guangshuai
Published: January 2021

In the teaching design of electromechanics integration for mechanism, three designs (machinery, motor and control) work in parallel. Before the mechanical team completes the design, the motor and control team needs to obtain information about the machinery in advance. The integrated teaching of the three elements of machinery, motor and control of the planar linkage mechanism is discussed in this article, creating an enhanced environment for electromechanics integration in teaching mechanism combining the virtual simulation and physical production, integrating the five aspects of design, simulation, control, manufacturing and testing, therefore establishing an innovation model of mechanical principles of research and exploratory type teaching, problem-oriented learning-type teaching.
Analysis on Theory of MIMO and Research on Channel Capacity of MIMO System
Authors: Wu Bo
Published: January 2021

By 2023, the average rate of global mobile network will increase to 44Mbps, 5G mobile communication network rate will reach 575Mbps [1]. Compared with 4G mobile communication, 5G mobile communication can support higher quality, higher transmission rate, higher user density and higher mobility performance, as well as lower delay and lower energy consumption scenarios [2]. With the advent of large-scale commercialization of 5G technology, the improvement of transmission performance can meet the growing communication needs of people well, and multiple antenna system (MIMO) has certain superiority in improving channel capacity. This article is aimed at introducing the working principle of MIMO system and the improvement of transmission performance brought by the technologies adopted. Furthermore, the proof of improvement of channel capacity brought by MIMO will be given. A channel model of MIMO communication system will be established through MATLAB, generating channel matrices randomly according to Gaussian distribution and then getting channel capacity by means of calculating the average value of multiple groups of data. The result shows that the channel capacity could improve greatly with the increase of the number of antennas under the condition of the same signal noise ratio (SNR), reaching the conclusion that MIMO system can effectively improve channel capacity.
A Framework for Low-cost Fusion Positioning with Single Frequency RTK/MEMS-IMU/VIO
Authors: Liu Xin , Li Deng , Shi Junjiong , Li Anran , Jiang Lin
Published: January 2021

In response to the demand for high-precision positioning in the consumer market for low-speed UAVs, this paper proposes an ultra-low-cost fusion positioning system architecture, selecting consumer-grade GNSS Ublox M8T, IMU MPU 9250 modules and binocular cameras as the main equipment. We fused raw data measured from multi-sensors by expansion Kalman filter(EKF), and tested the fusion positioning performance of MEMS-IMU and VIO through simulation interruption experiment. The experimental results show that the ultra-low-cost single-frequency RTK/VIO/MEMS-IMU multi-sensor fusion positioning system can provide high-precision, reliable, continuous and smooth positioning results.
Design and implementation of HPLC Communication module in Smart Grid
Authors: Luo Dan , Xiao Deyong , Zhang Xudong , Zhang Xiaohui , Tang Xiaoke , Zheng LI
Published: January 2021

In allusion to the problems of lower speed, weak anti-interference ability based on narrow band PLC (Power Line Communications) technology, a kind of HPLC (High-speed Power Line Communications) module used in ubiquitous power intelligent electricity acquisition system is designed. The HPLC module takings the SOC chip SC3105 as the master control chip transmit user datum between a concentrator and meters in high speed. Using abundant interrupts and timers, the system software fast processes accurate service messages and network management messages. The memory management mechanism of the system software recovers memory fragments and improves the use efficiency of memory, so as to keeping system stable. The test results show the module has over 1Mbps communication speed, 100% reading meter success rate, shorter reading meter time, and excellent communication performance in city power grids and village power grids, which solves the problems of narrow band PLC technology.
A blind classification method of adaptive coding and modulation signals based on cumulants
Authors: Chen Zhiqiang , Lei Jing , Liu Wei
Published: January 2021

This paper proposes a blind modulation classification method for adaptive coding and modulation signals base on the difference in high-order cumulants of different modulation types. Use high-order cumulants to establish features to design modulation classification algorithm and decision thresholds. Because of the time-varying characteristics of adaptive coding and modulation signals, the segmentation classification method is used to realize the modulation classification of each frame in the time dimension. Finally, the designed algorithm is simulated, and the classification performance of the algorithm under different modulation types, segment lengths and signal-to-noise ratios is analyzed.
Structure Design of Convolutional Neural Network Based on Residual Theory for Face Recognition
Authors: Chenchen Zhang , Hong Jin
Published: January 2021

Compared with the traditional face recognition methods, the deep convolution neural network model does not need to manually design complex and time-consuming feature extraction algorithms, but only needs to design an effective neural network model, and then carry out end-to-end, simple and efficient training on a large number of training samples, so as to obtain better classification accuracy. In this paper, based on the original VGG network model, combined with Residual theory, a deep-level residual convolutional neural network structure is designed and implemented, which not only reduces the computing power requirements of hardware computers, but also achieves better recognition results.
Image Fusion of PMMW and Optical Images for Concealed Object Detection
Authors: Zhang Lu , Pang Lei , Miao Jungang
Published: January 2021

This paper addresses a method of concealed objects detection by passive millimeter wave (PMMW) images, and on this basis, the fusion techniques of passive millimeter-wave images and optical images is discussed. According to PMMW real-time imager acquired image characteristics and storage methods, firstly, using correlation coefficient method to screen sequence images and the selected images are optimized using wavelet fusion algorithm. Secondly, the concealed objects are detected by Gaussian filter, threshold segmentation and edge detection. Finally, based on YIQ transform, discrete wavelet transform and a fusion rule, the optical image and the extracted concealed object contour are merged. The experimental results show that the proposed method can be effectively applied to human body concealed object detection in millimeter wave video and fuse two different types of images in a fully automated way.
Impact of the Half Space on High Resolution Range Profile
Authors: He Zhenyu , Xie Yongjun
Published: January 2021

High resolution range profile (HRRP) which contains the characteristics of the scattering centers of the target, has an important application in the field of radar automatic target recognition. Based on the formation principle of HRRP, this paper analyzes the scattering mechanism of targets in half space and the influence of half space environment on HRRP. The half space HRRP of the same object in different viewing angles and relative dielectric constant is obtained by simulation, and it is compared with the HRRP in free space to further verify the correctness of the analysis. The analysis results have certain significance for processing half space HRRPs and half space target recognition.
Voltage Sensitivity of Tag Antennas for Inductively Coupled RFID Systems
Authors: Jin Cheng , Zhu Jixuan
Published: January 2021

This paper describes a parameter of voltage sensitivity to recognize the performance differences of tag antennas for inductively coupled RFID systems. Based on the equivalent circuit model of the RFID tag and reader, an expression for the voltage sensitivity is educed. Then, the design steps of measuring platform to obtain the voltage sensitivity of tag antenna are introduced in detail. Finally, the feasibility of the proposed method was verified with the market available tag antennas through the measuring platform.
A Design of Monitoring System for Low-Voltage Distribution Station
Authors: Ju Gaofeng , Xu Peng , Zhou Min , Zhang LingLing , Fan XiaoLong , Yang Yongjie
Published: January 2021

In order to improve the low-voltage distribution station’s stability and safety, a monitoring system for this station based on the STM32 microprocessor is designed. The system can collect data on the environmental and switch status of multiple power distribution stations in the partial area through NB-loT Technology, then report it to the cloud platform server in the form of CoAP protocol with XTEA encryption algorithm. The cloud platform server transmits the data to the monitoring platform, categorizes and stores the node data. After on-site installation and deployment, the self-designed plug device can reduce the complexity of the plug-in. The system possesses the characteristics of instantaneity, automatic networking and high security, which can meet the industrial requirements well.
EEG signal representation of basic geometric bodies
Authors: Zhen-wei Wang , Hong-sheng Shi , Peng Cheng , Hong Chen
Published: January 2021

In the field of intelligent design, much attention is paid to the generation of design knowledge and experience. Today, EEG signal is a direct method to explore the design idea and brain consciousness. The purpose of this paper is to establish a basic geometric representation pattern of EEG signals. Firstly, the basic geometry representation of EEG signal is given, EEG signal is collected and the preprocessing method of EEG signal is proposed. Then, the feature extraction and recognition method of EEG signal is described, and the recognition rate is improved by feature decision fusion. Finally, the correctness of the representation pattern is verified by experiments.
Harmonic control system of smart meter based on ZigBee
Authors: Wang Yanyang , Hu Kefan , Zhang Jiaming
Published: January 2021

Under the background that the country vigorously advocates the development of smart grids, the first step is to develop smart meters. In order to achieve smart grid harmonic pollution control to compensate for non-function rate and reduce energy consumption, while monitoring power quality in real time, this paper proposes a ZigBee-based Communication protocol, using ADE7878 energy measurement embedded into STM32 unit to use the CC2430 of the meter node and Ethernet to transmit data and perform power quality analysis. The analysis results are combined with harmonic suppression algorithms to control the power quality controller to achieve power harmonics Governance. Supported by “the Fundamental Research Funds for the Central Research Funds for the Central”: 201910497134