bluuebunny/crossref_metadata_2025 huggingface dataset:
Untersuchung des Auf‐ und Abbaues von Wasserstoff‐ und Sauerstoffbelegungen an Platin mit einer neuen instationären Methode
Authors: Will F. G. , Knorr C. A.
Published: October 2023

Es wird ein Verfahren für elektrodenkinetische Messungen und seine Anwendung zur Untersuchung von Adsorptionserscheinungen an Platin beschrieben. Die Methode besteht im wesentlichen darin, daß zwischen der Versuchselektrode und einer Bezugselektrode praktisch stromlos eine Gleichspannung und cine Dreieckspannung variabler Amplitude und Frequenz mittels eines elektronischen Potentiostaten vorgegeben und der Zellenstrom oszillographisch registriert wird. Steigert man die Frequenz der periodischen Dreieckspannung, so ergibt sich bei Wasserstoffbespülung der Elektrode ein stetiger Übergang von der hauptsächlich durch die Transportvorgänge bedingten stationären zu der im wesentlichen durch die Umladungsvorgänge bestimmten instationären Kurve. Bei Anwendung von Stickstoffbespülung konnte zwischen 400 und 800 m V die Doppelschichtkapazität bestimmt und als unabhängig von der Dreieckfrequenz erwiesen werden. Der Auf‐ und Abbau der auf der Elektrodenoberfläche adsorbierten Wasserstoff‐ und Sauerstoffbelegungen in Abhängigkeit von der Bezugsspannung wurde durch graphische Integration der erhaltenen Strom‐Zeit‐Kurven quantitativ ermittelt. Die beim Schicht‐Aufbau und ‐Abbau vorhandenen Reaktionshemmungen wurden durch Variation der Dreieckfrequenz untersucht. Eine besonders große Hemmung ergab sich für den Abbau der Sauerstoffadsorptionsschichten, jedoch ist auch eine kennzeichnende Hemmung beim Auf‐ und Abbau der Wasserstoffschichten feststellbar. Die Untersuchung des Einflusses der anodischen Vorbehandlung der Elektrode ergab, daß durch diese “Aktivierung” neben der Reinigung eine beträchtliche Aufrauhung der Oberfläche eintritt, die im Laufe der Zeit wieder zurückgeht.
Zur Analyse der Langperiodeninterferenzen
Authors: Bonart R. , Hosemann R.
Published: October 2023

Es wird gezeigt, daß die konventionelle Interpretation der bekannten Langperiodeninterferenzen an synthetischen Faserstoffen unbefriedigend ist. Als neues Strukturmodell für den Aufbau einer Elementarfibrille wird deshalb ein aus statistisch gekrümmten Schichten bestehendes sog. parakristallines Schichtgitter vorgeschlagen, wobei die Schichten die sog. „kristallinen”︁ und die dazwischen liegenden Bereiche die sog. „amorphen”︁ Anteile wiedergeben. Auf Grund dieses neuen Strukturmodelles können alle wesentlichen Parameter der Langperiodeninterferenzen zwanglos gedeutet werden. Lichtoptisch gewonnene Beugungsbilder zweidimensionaler Strukturmodelle veranschaulichen die diskutierten Zusammenhänge.
Absorptionsspektren und Basizität der Phenanthroline und verwandter Verbindungen
Authors: Perkampus H.‐H. , Köhler H.
Published: October 2023

In der vorliegenden Arbeit werden die Absorptionsspektren und ihre pH‐Abhängigkeit von 7 Phenanthrolinen, sowie einigen strukturell ähnlichen Verbindungen mitgeteilt. Die Diskussion der Spektren in bezug auf das Phenanthren als Grundgerüst zeigt, daß die Änderung des Phenanthrenspektrums durch die hetero‐zyklischen N‐Atome weniger spezifisch ist als beispielsweise bei Naphthalin‐Chinolin. Auch die pH‐Abhängigkeit dieser Spektren trägt hier weniger zur Klärung bei.

Aus der pH‐Abhängigkeit der Absorptionsspektren wurden die pk‐Werte sämtlicher Gleichgewichte, einschließlich derer, die im Bereich der Hammettschen Säurefunktion liegen, ermittelt. Die aus der Temperaturabhängigkeit der PK‐Werte gewonnenen thermodynamischen Daten werden im Zusammenhang mit der Konstitution dieser Verbindungen diskutiert.
Die Untersuchung schnell verlaufender protolytischer Reaktionen mit der Blitzlichtmethode
Authors: Breitschwerdt K. , Weller A.
Published: October 2023

Der Reaktionszyklus (siehe unten) bei der Fluoreszenzumwandlung aromatischer Oxyverbindungen (ROH) in neutraler und schwach saurer wäßriger Lösung wurde dazu benutzt, mittels eines intensiven Lichtblitzes von 8 μsec Dauer einige Prozent der vorliegenden ROH über die Reaktion im angeregten Zustand zu RO− zu dissoziieren. Die Wiedereinstellung des gestörten Gleichgewichts wurde absorptionsspektroskopisch verfolgt. Durch oszillographische Registrierung der zeitlichen Abnahme der RO−‐Konzentration nach dem Blitz konnte so die Geschwindigkeit der Reaktion

equation image

ermittelt werden. Dabei zeigte sich, daß bei schwächeren Säuren (pK > 8) die Reaktion:
equation image
wesentlich zur Wiedereinstellung des Gleichgewichts beiträgt.
Bestimmung der Diffusionskoeffizienten D, D und D mit der Platinscheibenelektrode
Authors: Breiter M. , Hoffmann K.
Published: October 2023

Es wird die Versuchsapparatur für eine in unserem Institut erstellte Scheibenelektrode beschrieben. Aus Messungen der anodischen Grenzstromdichte der Wasserstoffmoleküle wird der Diffusionskoeffizient DH2 in 0,5n‐H2SO4, 5n‐H2SO4, und 0,1m‐Na2SO4im Temperaturbereich ‐ 10°C bis 60°C mittels der Lewitsch‐Formel bestimmt.

Der Diffusionskoeffizient D wird in schwach saurer 0,1m‐Na2SO4 bei 20°C aus der kathodischen Grenzstromdichte der H+‐Ionen und der Diffusionskoeffizient D in schwach alkalischer 0,1m‐Na2SO4 aus der anodischen OH−‐Ionengrenzstromdichte ermittelt.
Zur spektralen Empfindlichkeit photographischer Schichten II
Authors: Eggert J. , Pestalozzi H.
Published: October 2023

Für Sensibilisierungsfarbstoffe photographischer Schichten besteht, wenn man den Vorgang als Elektronenmechanismus beschreibt, das Problem, wie die Farbstoffmolekeln nach Abgabe eines Elektrons in den Anfangszustand zurückkehren können, ohne daß zusätzliche Energie benötigt wird. Am einfachsten geschieht dies, wenn das fehlende Elektron im Farbstoff aus Zwischentermen des adsorbierenden Silberbromids ergänzt wird, die durch Gitterfehler oder Fremdionen verursacht werden.—In der vorliegenden Arbeit wird zu zeigen versucht, daß ein solcher Mechanismus der Sensibilisation mit um so größerer Ausbeute erfolgt, je gestörter das ursprüngliche Silberbromidgitter ist.—Als Ausgangsmaterial wird eine Sedimentschicht von reinem Silberbromid benützt, die lediglich eine Eigenempfindlichkeit im Blau, aber praktisch keine Empfindlichkeit im Grün und im Rot besitzt. Diese Schicht kann durch Reifen mit Natriumthiosulfat oder durch eine Vorbehandlung mit reinem Wasser zu erhöhten Empfindlichkeiten für längere Wellen gebracht werden, wobei also jene Zwischenterme und die damit verbundene längerwellige Absorption des Silberbromids entstehen. Diese Empfindlichkeitssteigerung zeigt sich im gleichen Maße sowohl bei der unsensibilisierten wie auch bei der mit Farbstoff sensibilisierten Schicht.
Ein isothermes Wärmeströmungskalorimeter für höhere Temperaturen
Authors: Wittig Franz Eberhard , Schilling Werner
Published: October 2023

Eine Analyse der prinzipiellen Fehlerquellen der Erwärmungskalorimetrie und der adiabatischen Kalorimeter bei höheren Temperaturen führt zu dem Versuch, ein isothermes Kalorimeter zu realisieren. Dieses arbeitet bei konstanter Temperatur des Thermostaten, konstanter Temperaturdifferenz zwischen Thermostat und Kalorimeter und daher auch bei konstantem Wärmestrom. Das Kalorimeter wird mit einer höheren konstanten elektrischen Leistung beheizt, als für den Wärmestrom erforderlich wäre, die vorgegebene Temperaturdifferenz mit einem quasi‐stetigen P‐Regler eingestellt und die Einschaltdauer der elektrischen Heizung mit einem Zeitmesser summiert und äquidistant registriert. Dazu müssen Modulationsregler nach Wittig und Kemeny mit konstanter Modulationsperiode verwendet werden, die eine Synchronisation mit der Begrenzung der Ableseperioden ermöglichen. Reaktionswärmen werden als Differenzen gegen die konstanten summierten Einschaltzeiten in Vor‐ und Nachperiode erhalten, so daß sich die kalorimetrische Messung auf eine äquidistante Registrierung eines Zeitmessers reduzieren läßt. Das Verfahren weist eine Reihe von Vorzügen auf, die auch andere Anwendungen als aussichtsreich erscheinen lassen. So entfällt eine gesonderte Bestimmung von Wasserwert und Wärmeaustauschkonstanten, und Messung und elektrische Eichung erfolgen in einem Arbeitsgang. Die Auswertung läßt sich ebenfalls einfach und schnell ausführen, und im einfachsten Fall müssen nur vier Ablesungen des Zeitmessers ausgeführt werden. Systematische Fehler können aus Regelabweichungen des P‐Reglers sowie aus einer mangelhaften Äquivalenz der Wärmeverteilung resultieren, lassen sich aber erkennen, als Korrektur berücksichtigen oder durch weitere Maßnahmen beseitigen. Als Anwendung wird die Zerfallswärme des Stickoxyduls N2O bei 460°C bestimmt.
Photoisomerization of Cycloheptatriene. II: Temperature Dependence of Collisional Energy Transfer
Authors: Luu S. H. , Troe J.
Published: October 2023

The photoisomerization of cycloheptatriene to toluene at 2600 Å has been studied in the temperature range 293673 K in the presence of various inert gases. The temperature dependence of the Stern‐Volmer constants for collisional deactivation has been analyzed. Various model functions for the specific rate constants of isomerization k(E) and for the collisional transition probabilities have been discussed. Independently of the uncertainties in these models, one finds that the average amounts of energy <ΔE> transferred per collision depend only very slightly on the temperature T. A slight increase of ∣ΔE∣ with T for inefficient colliders and a slight decrease for efficient ones appear possible, but are within the uncertainty of the present experiments.
Molwärmen binärer Systeme aus Cyclohexan, Kohlenstofftetrachlorid, Siliziumtetrachlorid und Zinntetrachlorid
Authors: Wilhelm Emmerich , Zettler M. , Sackmann H.
Published: October 2023

In den sechs flüssige binären Mischungen aus Cyclohexan, Kohlenstofftetrachlorid, Siliziumtetrachlorid und Zinntetrachlorid wurde die Molwärme bei konstantem Druck, CP, über den gesamten Konzentrationsbereich (einschließlich der Reinstoffe) zwischen O°C bzw. 10°C und 50°C bestimmt. In allen Fällen treten negative Abweichungen vom Idealverhalten auf. Für äquimolare Konzentrationen betragen diese Abweichungen (ΔCP) zwischen ‐0,16 JK−1 mol−1 (für C6H12CCl4) und ‐2,70 JK−1 mol−1 (für C6H12SnCl4). Der Temperaturkoeffizient dΔCP/dTist stets klein und positiv.

Bereits bekannte Werte der Schallgeschwindigkeit, des Ausdehnungskoeffizienten und des Molvolumens wurden benutzt, um aus dem experimentell ermittelten CP die Molwärme bei konstantem Volumen, Cv (entlang der orthobarischen Kurve), und die isotherme und adiabatische Kompressibilität zu berechnen.

Für die Reinstoffe wurden die Größen (∂Cv/∂T)v und (∂Cv/∂V)T berechnet. Eine Abschätzung des Rotationsbeitrages zur residuellen Molwärme fär die Reinstoffe wurde gegeben. Für die Mischungen wurde die Zusatzmolwärme bei konstantem Volumen ΔCv und die Zusatzkompressibilität Δ(Vβ) berechnet. Eine Interpretation von ΔCv in Termen des Rotationsverhaltens der Komponenten wurde versucht.
Insights into the Biological Activity and Cytotoxic Mechanism of Epimedium pubigerum
Authors: Seyhan Gökçe , Akkaya Didem , Kolci Kübra , Reis Rengin , Yazici Nurdan , Nur Barut Elif , Barut Burak
Published: October 2023

In this work, the phytochemical characterization, biological activity, and cytotoxic mechanism of aerial and rhizome methanol extracts (SME and RME) of Epimedium pubigerum were investigated to demonstrate its potential usage in the treatment of lung cancer. LC‐HRMS analysis, total phenolic/flavonoid content assay, DPPH radical scavenging assay, DNA interaction, cytotoxicity, and western blotting were investigated using different methods. Fumaric acid was found to be the most abundant compound in both extracts. SME and RME were cytotoxic on A549 cells concentration‐dependently. Also, in vitro scratch assay showed that SME and RME led to a significant anti‐migratory effect at 1 mg/mL. Cytochrome c, p53, and caspase 3 expression significantly increased in the presence of RME compared to the control. All of these results claimed that RME might be suggested as a theoretically more effective phytotherapeutic agent for lung cancer compared to the effect seen with the SME.
Novel Corncob‐Based Catalytic Biodiesel Production Process: Experiments, Modeling, and Simulation
Authors: Hussain Zakir , Lingareddy Joji Reddy , Sulthana Nazleen , Boddu Shashi Kanth
Published: October 2023

A functionalized catalyst for catalyzed biodiesel production via a heterogeneous route is a highly focused area to lower the cost of production and mitigate the drawbacks of homogeneously catalyzed reactions. Production aspects such as parameter study, kinetics modeling, and simulation of continuous process flowsheets incorporating kinetic parameters are scarce in the literature. In the current work, a sulfonic group‐functionalized porous carbonaceous catalyst based on corncob was used for the esterification of oleic acid. The Langmuir‐Hinshelwood‐Hougen‐Watson (LHHW) kinetic model was found to best fit to correlate the experimental data and thus applied to deduce the kinetic parameters. The obtained kinetic parameters were incorporated into the Aspen Plus simulator to simulate the continuous biodiesel production process. The catalyst showed a strong affinity for oleic acid which enhances the reaction rate.
Direct Lithium Extraction Using Intercalation Materials
Authors: Wang Jing , Koenig Gary M.
Published: October 2023

Worldwide lithium demand has surged in recent years due to increased production of Li‐ion batteries for electric vehicles and stationary storage. Li supply and production will need to increase such that the transition towards increased electrification in the energy sector does not become cost prohibitive. Many countries have taken policy steps such as listing Li as a critical mineral. Current commercial Li mining is mostly from dedicated mine sources, including ores, clays, and brines. The conventional ways to extract Li+ from those resources are through chemical processing and includes steps of calcination, leaching, precipitation, and purification. The environmental and economic sustainability of conventional Li processing has recently received increased scrutiny. Routes such as direct Li+ extraction may provide advantages relative to conventional Li+ extraction technologies, and one possible route to direct Li+ extraction includes leveraging intercalation materials. Intercalation material processing has recently demonstrated high selectivity towards Li+ as opposed to other cations. Reviews and reports of direct Li+ extraction with intercalation materials are limited, even as this technology has started to show promise in smaller‐scale demonstrations. This paper will review selective Li+ extraction via intercalation materials, including both electrochemical and chemical methods to drive Li+ in and out, and efforts to characterize the Li+ insertion/deinsertion processes.
Establishing Modular Cell‐Free Expression System for the Biosynthesis of Bicyclomycin from a Chemically Synthesized Cyclodipeptide†
Authors: Liu Yi‐Pei , Zhao Yu‐Heng , Zhang Wen‐Qi , Wu Lian , Huang Linjuan , Tang Gong‐Li , He Jun‐Bin
Published: October 2023

Comprehensive Summary

Cell‐free expression systems have emerged as a versatile and powerful platform for metabolic engineering, biosynthesis and synthetic biology studies. Nevertheless, successful examples of the synthesis of complex natural products using this system are still limited. Bicyclomycin, a structurally unique and complex diketopiperazine alkaloid, is a clinically promising antibiotic that selectively inhibits the transcription termination factor Rho. Here, we established a modular cell‐free expression system with cascade catalysis for the biosynthesis of bicyclomycin from a chemically synthesized cyclodipeptide. The six cell‐free expressed biosynthetic enzymes, including five iron‐ and α‐ketoglutarate‐dependent dioxygenases and one cytochrome P450 monooxygenase, were active in converting their substrates to the corresponding products. The co‐expressed enzymes in the cell‐free module were able to complete the related partial pathway. In vitro biosynthesis of bicyclomycin was also achieved by reconstituting the entire biosynthetic pathways (i.e., six enzymes) using the modular cell‐free expression system. This study demonstrates that the modular cell‐free expression system can be used as a robust and promising platform for the biosynthesis of complex antibiotics.
Navigating the Sotatercept landscape: A meta‐analysis of clinical outcomes
Authors: Nasrollahizadeh Amir , Soleimani Hamidreza , Nasrollahizadeh Ali , Hashemi Seyedeh Melika , Hosseini Kaveh
Published: October 2023

Pulmonary arterial hypertension (PAH) is a widespread condition that affects around 1% of the global population, with a higher prevalence among older individuals. The approach to managing PAH has undergone significant changes, requiring extensive treatment strategies. Sotatercept, an FDA‐approved medication, has recently attracted attention for its potential role in PAH therapy. However, information on its safety and effectiveness is scarce. In this study, we performed a meta‐analysis of existing randomized clinical trials to assess the impact of Sotatercept on PAH patients. Our findings revealed that those treated with Sotatercept showed greater improvement in pulmonary vascular resistance and World Health Organization functional class compared with placebo recipients. The occurrence of adverse events was similar between both groups. Importantly, the Sotatercept group displayed a considerably higher number of cases with an increase in hemoglobin levels. Considering that about 33% of PAH patients experience anemia and both anemia and polycythemia can adversely affect disease prognosis, additional research is necessary to establish the potential advantages and disadvantages of Sotatercept as a treatment choice, specifically regarding its erythropoietic properties.
Development of Photoswitchable Tethered Ligands that Target the μ‐Opioid Receptor
Authors: Lahmy Ranit , Hübner Harald , Lachmann Daniel , Gmeiner Peter , König Burkhard
Published: October 2023

Converting known ligands into photoswitchable derivatives offers the opportunity to modulate compound structure with light and hence, biological activity. In doing so, these probes provide unique control when evaluating G‐protein‐coupled receptor (GPCR) mechanism and function. Further conversion of such compounds into covalent probes, known as photoswitchable tethered ligands (PTLs), offers additional advantages. These include localization of the PTLs to the receptor binding pocket. Covalent localization increases local ligand concentration, improves site selectivity and may improve the biological differences between the respective isomers. This work describes chemical, photophysical and biochemical characterizations of a variety of PTLs designed to target the μ‐opioid receptor (μOR). These PTLs were modeled on fentanyl, with the lead disulfide‐containing agonist found to covalently interact with a cysteine‐enriched mutant of this medically‐relevant receptor.
Local laws and a mesoscopic CLT for β‐ensembles
Authors: Peilen Luke
Published: October 2023

We study the statistical mechanics of the log‐gas, or β‐ensemble, for general potential and inverse temperature. By means of a bootstrap procedure, we prove local laws on the next order energy that are valid down to microscopic length scales. To our knowledge, this is the first time that this kind of a local quantity has been controlled for the log‐gas. Simultaneously, we exhibit a control on fluctuations of linear statistics that is valid at all mesoscales using Johansson's method and a transport approach. Using these local laws, we are able to exhibit for the first time a CLT at arbitrary mesoscales, improving upon previous results that were true only for power mesoscales.
Effect of Sb Doping on Structure and Humidity Sensing Properties of SnO2 Synthesized by Hydrothermal Method
Authors: Ding Yuchuan , Niu Liyan , Chen Yong , Wang MaoHua
Published: October 2023

The tetragonal rutile Sb doped Sn O2 (0, 0.5, 1 at.%) is successfully synthesized by hydrothermal method. The XRD analysis shows that the average crystallite size of SnO2 decreases from 29.59 to 20.53 nm with the increase of the doping concentration. SEM images depict the spherical grain morphology of the SnO2 sample. With the increase of the doping ratio, the optical bandgap value of the SnO2 samples increases from 3.6 to 3.86 eV and then decreases to 3.47 eV, showing a trend of first increasing and then decreasing. XPS results indicate that oxygen vacancy defects and substitutional defects(SbSn)are formed into the SnO2 lattice, which changes the electronic effect of Sn element to tune the oxygen vacancy concentration. The humidity‐sensitive testing data shows that 1 at.% Sb‐doped SnO2 humidity sensor presented excellent sensitivity and linearity at a working frequency of 100 Hz as compared to the pure SnO2 sample.
The Comparative Third‐Order Nonlinearities of Titanium Carbide and Tungsten Carbide in the Visible Regain
Authors: Nadafan Marzieh , Majidi Roya , Khashehchi Morteza , Shahram Shamim , Safdari Mohammad , Dehghani Zahra
Published: October 2023

This study investigates the structure and properties of Titanium carbide (TiC) and Tungsten carbide (WC) nanoparticles. The X‐ray diffraction patterns confirm the presence of a hexagonal structure in WC nanoparticles and cubic structure in TiC nanoparticles. Transmission electron microscopy analysis reveals the particle sizes to be within the range of 30–50 nm. The bandgap of TiC and WC nanoparticles are 3.5 and 3.6 eV, respectively based on diffuse reflectance spectroscopy (DRS) along with Kubelka–Munk. Furthermore, the optical phonons and dielectric function of WC and TiC nanoparticles are investigated using the reflectance spectra along with the Kramers–Kronig (KK) method. Furthermore, the Z‐scan technique, employing a Nd:YAG laser operating at a wavelength of 532 nm, is utilized to assess the nonlinear optical (NLO) characteristics of WC and TiC nanoparticles. The open aperture Z‐scan measurements of WC nanoparticles indicate reverse saturable absorption (RSA) behavior and a positive nonlinear refraction (NLR) coefficient. On the other hand, TiC nanoparticles show RSA behavior with a negative NLR effect. The order of NLR, nonlinear absorption coefficient, and the susceptibility of TiC and WC are 10−8 cm2 W−1, 10−4 cm W−1, and 10−6 esu, respectively.
Brief history of the alcohol biomarkers CDT, EtG, EtS, 5‐HTOL, and PEth
Authors: Jones Alan Wayne
Published: October 2023

This article traces the historical development of various biomarkers of acute and/or chronic alcohol consumption. Much of the research in this domain of clinical and laboratory medicine arose from clinics and laboratories in Sweden, as exemplified by carbohydrate deficient transferrin (CDT) and phosphatidylethanol (PEth). Extensive studies of other alcohol biomarkers, such as ethyl glucuronide (EtG), ethyl sulfate (EtS), and 5‐hydroxytryptophol (5‐HTOL), also derive from Sweden. The most obvious test of recent drinking is identification of ethanol in a sample of the person's blood, breath, or urine. However, because of continuous metabolism in the liver, ethanol is eliminated from the blood at a rate of 0.15 g/L/h (range 0.1–0.3 g/L/h), so obtaining positive results is not always possible. The widow of detection is increased by analysis of ethanol's non‐oxidative metabolites (EtG and EtS), which are more slowly eliminated from the bloodstream. Likewise, an elevated ratio of serotonin metabolites in urine (5‐HTOL/5‐HIAA) can help to disclose recent drinking after ethanol is no longer measurable in body fluids. A highly specific biomarker of hazardous drinking is CDT, a serum glycoprotein (transferrin), with a deficiency in its N‐linked glycosylation. Another widely acclaimed biomarker is PEth, an abnormal phospholipid synthesized in cell membranes when people drink excessively, having a long elimination half‐life (median ~6 days) during abstinence. Research on the subject of alcohol biomarkers has increased appreciably and is now an important area of drug testing and analysis.
Pharmaceuticals and Personal Care Products in the Aquatic Environment: How Can Regions at Risk be Identified in the Future?
Authors: Wilkinson John L. , Thornhill Ian , Oldenkamp Rik , Gachanja Anthony , Busquets Rosa
Published: October 2023

Pharmaceuticals and personal care products (PPCPs) are an indispensable component of a healthy society. However, they are well-established environmental contaminants, and many can elicit biological disruption in exposed organisms. It is now a decade since the landmark review covering the top 20 questions on PPCPs in the environment (Boxall et al., 2012). In the present study we discuss key research priorities for the next 10 years with a focus on how regions where PPCPs pose the greatest risk to environmental and human health, either now or in the future, can be identified. Specifically, we discuss why this problem is of importance and review our current understanding of PPCPs in the aquatic environment. Foci include PPCP occurrence and what drives their environmental emission as well as our ability to both quantify and model their distribution. We highlight critical areas for future research including the involvement of citizen science for environmental monitoring and using modeling techniques to bridge the gap between research capacity and needs. Because prioritization of regions in need of environmental monitoring is needed to assess future/current risks, we also propose four criteria with which this may be achieved. By applying these criteria to available monitoring data, we narrow the focus on where monitoring efforts for PPCPs are most urgent. Specifically, we highlight 19 cities across Africa, Central America, the Caribbean, and Asia as priorities for future environmental monitoring and risk characterization and define four priority research questions for the next 10 years. Environ Toxicol Chem 2024;43:575–588. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
FIGO good practice recommendations for cesarean delivery: Prep‐for‐Labor triage to minimize risks and maximize favorable outcomes
Authors: Barnea Eytan R. , Inversetti Annalisa , Di Simone Nicoletta ,   the FIGO Childbirth and Postpartum Hemorrhage Committee
Published: October 2023

Cesarean delivery is an abdominal surgical procedure performed for child delivery when the vaginal route is not feasible or desired due to maternal/fetal indications. All childbirth facilities should be able to safely perform a cesarean, which is not the current reality. For planned cesarean delivery, the facility must be prepared for the patient. In contrast, for unplanned arrivals at the facility, FIGO's Prep‐for‐Labor triage method allows rapid decision‐making on whether cesarean delivery can be safely performed on site or whether transfer to an advanced care center is needed. A checklist of staff/tools for safe on‐site cesarean delivery is provided to enable timely decision‐making. Maternal complications following cesarean are three‐fold higher than vaginal delivery. To prevent nonmedically indicated cesarean by favoring vaginal delivery, up‐to‐date safe and effective guidance is provided, defining labor, second stage length, and status before an arrested labor is confirmed. Whether cesarean delivery is planned or emergency, the Misgav Ladach simplified procedure is proposed as it is suitable for both low‐ and high‐risk cases, including twins, thereby reducing both operative morbidity and postoperative recovery. A trial of labor after first cesarean (TOLAC) should be pursued when feasible, for which the indications, contraindications, safeguards, and steps of safe labor induction are delineated. Implementation of these good practice recommendations will improve childbirth by reducing excessive nonindicated cesareans, while precisely defining the resources and postoperative care required for safe performance on site. Enabling safe childbirth by cesarean and TOLAC, even at sites with low rates currently, will significantly improve maternal and fetal outcomes.
FIGO good practice recommendations on surgical techniques to improve safety and reduce complications during cesarean delivery
Authors: Nunes Inês , Nicholson Wanda , Theron Gerhard ,   the FIGO Childbirth and Postpartum Hemorrhage Committee
Published: October 2023

FIGO is actively contributing to the global effort to reduce maternal morbidity, mortality, and disability worldwide. Cesarean delivery rates are increasing globally, without signs of slowing down. Bleeding associated with cesarean delivery has become an important cause of hemorrhage‐related maternal deaths in many low‐ and middle‐income countries. Correct surgical techniques to improve safety and reduce complications of cesarean delivery is of the utmost importance. This article presents FIGO's good practice recommendations for effective surgical techniques to reduce cesarean complications. Evidence‐based information is included where data are available. An expanded WHO Surgical Safety Checklist for maternity cases is suggested. Different incision techniques through the layers of the abdominal wall with appropriate indications are discussed. Hysterotomy through a transverse incision is described, as are indications for low vertical and classical incisions. Important precautions when extracting the fetus are explained. Uterine closure includes a safe method ensuring adequate reapproximation of the upper segment if a vertical incision is made. The paper concludes with the management of two common bleeding problems following delivery of the placenta.
Deep learning‐based robust hybrid approaches for brain tumor classification in magnetic resonance images
Authors: Krishnasamy Narayanan , Ponnusamy Thangaraj
Published: October 2023

The classification of brain images is an immensely challenging task and one of the most valuable and frequently employed procedures in the field of medical diagnostics. Deep Learning (DL), which falls under the umbrella of artificial intelligence, has introduced novel techniques for automated analysis of medical images. The objective of this study was to develop two hybrid DL models for the segmentation and classification of brain magnetic resonance imaging (MRI) data. The first hybrid model combines fully convolutional networks (FCNs) and residual networks (ResNets) for both segmentation and classification purposes. The second model is a hybrid of SegNet for segmentation and MobileNet for classification. Rest assured, it will provide you with a dependable and promising performance. The analysis was conducted on a labeled dataset comprising images of glioma, meningioma, pituitary, and no‐tumor cases. Python was utilized to implement the aforementioned hybrid models. The proposed models achieved remarkable accuracies of 93.9% and 91.3%, respectively, when evaluated on a brain tumor MRI dataset. Additionally, a comprehensive evaluation of the proposed models was conducted, comparing them with other existing hybrid models in terms of metrics such as the dice score, Jaccard index, positive predictive value (PPV), false predictive value (FPV), testing time, precision, recall, specificity, and F1 score. The results demonstrated that the proposed DL technique can significantly assist doctors and radiologists in the early detection of brain tumor cells.
Curiosity and Intellectual Wellness: Does being curious help counselors stay well?
Authors: Hamilton Mark A. , Granello Darcy Haag , Arjune Bhudayal , Granello Paul F.
Published: October 2023

Counselors and counseling students (N = 125) were surveyed to determine whether curiosity could predict Intellectual Wellness. Structure coefficients found Diversive Curiosity accounted for 19% of the variance and Specific Curiosity for 11%. Implications are including curiosity into training and practice and future research on isolating variables that comprise wellness domains.
Regulatory effect of graphene on growth and carbon/nitrogen metabolism of maize (Zea mays L.)
Authors: Wang Shiya , Wang Xinyi , Liu Ying , Sun Guangxu , Kong Deyong , Guo Wei , Sun Haiyan
Published: October 2023

BACKGROUND

Leakage of graphene into the environment has resulted from its increasing use. Although the impact of graphene on ecosystems is already in full swing, information regarding its impact on plants is lacking. In particular, the effects of graphene on plant growth and development vary, and basic information on the regulation of carbon and nitrogen metabolism is missing. In the current study, the way in which graphene (0, 25, 50, 100, and 200 g kg−1) affects maize seedlings was studied in terms of morphological and biochemical indicators. The purpose of this study was to understand better how graphene regulates plant carbon and nitrogen metabolism and to understand its interactions with leaf structure and plant growth.

RESULTS

The results showed that 50 g kg−1 graphene increased plant height, stem diameter, leaf area, and dry weight; however, this was inhibited by the high level of graphene (200 g kg−1). Further studies indicated that different concentrations of graphene could increase leaf thickness and vascular bundle area as well as the net photosynthetic rate (Pn) of leaves; 25 and 50 g kg−1 graphene enhanced the leaves stomatal conductance (Cond), transpiration rate (Tr), intercellular carbon dioxide (Ci), and chlorophyll content. Higher concentrations decreased the above indicators. At 50 g kg−1, graphene increased the activity of carbon/nitrogen metabolism enzymes by increasing carbon metabolites (fructose, sucrose, and soluble sugars) and soluble proteins (nitrogen metabolites). These enzymes included sucrose synthase (SS), sucrose phosphate synthase (SPS), nitrate reductase (NR), glutamine synthase (GS), and glutamate synthase (GOGAT).

CONCLUSION

These results indicate that graphene can regulate the activities of key enzymes involved in carbon and nitrogen metabolism effectively and supplement nitrogen metabolism through substances produced by carbon metabolism by improving photosynthetic efficiency, thus maintaining the balance between carbon and nitrogen and promoting plant growth and development. The relationship between these indexes explained the mechanism by which graphene supported the growth of maize seedlings by enhancing photosynthetic carbon metabolism and maintaining metabolic balance. For maize seedling growth, graphene treatment with 50 g kg−1 soil is recommended. © 2023 Society of Chemical Industry.
Postharvest wine grape dehydration: ethanol dissipation from grape and biochemical changes
Authors: Bianchi Alessandro , Pettinelli Stefano , Santini Gregorio , Taglieri Isabella , Zinnai Angela , Petriccione Milena , Magri Anna , Modesti Margherita , Cerreta Raffaele , Bellincontro Andrea
Published: October 2023

BACKGROUND

During postharvest dehydration, grapes are subject to metabolic changes including ethanol anabolism and catabolism. These changes affect the quality of the final product and ethanol production is a key step. Ethanol dissipation has never been measured during postharvest wine grape dehydration. Thus, the present study aimed to: (i) monitor ethanol dissipation and (ii) investigate chemical–biochemical changes in berries during dehydration.

RESULTS

Ethanol dissipation from Raboso grapes, under controlled postharvest dehydration, was found to comprise up to 36% of weight loss (w.l.). Moreover, the activity of enzymes involved in the anaerobic metabolism of grapes was investigated. Ethanol dissipation was highly correlated with grape weight loss (r2 = 0.989). Alcohol dehydrogenase activity, responsible for the reduction of ethanol to acetaldehyde, declined significantly with w.l. Similarly, pyruvate decarboxylase and lactate dehydrogenase reduced their activity. High lipoxygenase activity was measured at 27% w.l., whereas polyphenol oxidation was constant and declined in the last sampling.

CONCLUSION

Ethanol dissipation during postharvest dehydration allows for reducing anaerobic metabolism and promotes oxidative metabolism. The sensor used can be a useful commercial tool for monitoring berry metabolism. © 2023 Society of Chemical Industry.
Surface Nanomechanics of Bacteria under UV Radiation
Authors: Zhang Weixiong , Zhang Liping , Mai Zhihui , Qian Lu , Gong Xiangjun , Ngai To
Published: October 2023

It is well established that UV radiation can inactivate bacteria by destroying DNA in the cell envelope, and maintaining the integrity of the cellular membrane. However, how UV radiation changes the surface properties and thus affects bacterial adhesion remain elusive. In this study, single‐cell force spectroscopy is employed to examine the surface nanomechanics of Pseudomonas aeruginosa under UV exposure. It shows that P. aeruginosa became stiffer after UV radiation, and its adhesion to silicon surface decreases with rupture length increasing. Nanospring signatures in the retraction force curve become less with lower spring constant but more plateau signatures with higher rupture length appear. These facts indicate the unfolding of the α‐helices of the pili. Besides, the worm‐like chain force curves with higher contour length indicate the structural degradation of transmembrane proteins or surface macromolecules obstruction. Accordingly, the bacterial adhesion decreases after UV radiation.
Melt Electrowriting of Nylon‐12 Microfibers with an Open‐Source 3D Printer
Authors: Reizabal Ander , Devlin Brenna L. , Paxton Naomi C. , Saiz Paula G. , Liashenko Ievgenii , Luposchainsky Simon , Woodruff Maria A. , Lanceros‐Mendez Senentxu , Dalton Paul D.
Published: October 2023

This study demonstrates how either a heated flat or cylindrical collector enables defect‐free melt electrowriting (MEW) of complex geometries from high melting temperature polymers. The open‐source “MEWron” printer uses nylon‐12 filament and combined with a heated flat or cylindrical collector, produces well‐defined fibers with diameters ranging from 33 ± 4 to 95 ± 3 µm. Processing parameters for stable jet formation and minimal defects based on COMSOL thermal modeling for hardware design are optimized. The balance of processing temperature and collector temperature is achieved to achieve auxetic patterns, while showing that annealing nylon‐12 tubes significantly alters their mechanical properties. The samples exhibit varied pore sizes and wall thicknesses influenced by jet dynamics and fiber bridging. Tensile testing shows nylon‐12 tubes are notably stronger than poly(ε‐caprolactone) ones and while annealing has limited impact on tensile strength, yield, and elastic modulus, it dramatically reduces elongation. The equipment described and material used broadens MEW applications for high melting point polymers and highlights the importance of cooling dynamics for reproducible samples.
Professional competence required in advanced practice nursing in critical care: An exploratory qualitative study
Authors: Solberg Marianne Trygg , Pedersen Ingunn , Mathisen Cathrine , Finnstrøm Inger Johanne , Lundin Per Kristian , Nes Andréa Aparecida Gonçalves
Published: October 2023

Aim

To identify the required competencies of advanced practice nurses (APNs) working with patients in critical care units in Norway.

Design

An exploratory qualitative design.

Methods

Four focus group interviews were performed with 18 nurses who worked in critical care units. The data were examined by inductive content analysis following Graneheim and Lundman's approach.

Findings

Our study found that APNs in critical care require the following professional competencies to meet the needs of patients characterised by greater age, comorbidities and increased complexity: (1) intrapersonal skills as revealed in the subthemes of self‐awareness; motivation and commitment; strong mental health and upholding ethical standards, (2) advanced clinical decision‐making skills as identified in the subthemes of integration of theory and practice; complex practical and technical skills; dealing with increased delegated responsibility and taking the lead in managing increased practice complexity and (3) interpersonal skills, including peer guidance, practising collaboratively and the ability to position oneself.
Maximal daily stepping cadence partially explains functional capacity of individuals with end‐stage knee osteoarthritis
Authors: Hoffman Rashelle M. , Davis‐Wilson Hope C. , Hanlon Shawn , Swink Laura A. , Kline Paul W. , Juarez‐Colunga Elizabeth , Melanson Edward L. , Christiansen Cory L.
Published: October 2023

Background

Individuals with end‐stage knee osteoarthritis (OA) walk at a lower intensity (ie, slower step cadence) contributing to worse physical function. Previous literature reports daily step counts and sedentary time, with little information regarding stepping bouts or cadence. Determining relationships between daily higher stepping cadence duration and clinical outcomes can move the field toward optimal daily stepping prescription.

Objective

To quantify daily physical activity patterns of individuals with end‐stage knee OA and determine the contribution of high stepping cadence to explain functional capacity variability.

Design

Cross‐sectional analysis.

Setting

Veterans Administration medical center.

Participants

U.S. military veterans (n = 104; age: 67.1 years [7.2]; mean [SD]; male [89.3%]) with end‐stage knee OA were enrolled.

Intervention

Not applicable.

Main outcome measure

Functional capacity (6‐Minute Walk Test [6MWT]). Physical activity (activPAL wearable sensor; cadence and time sitting, standing, and stepping), pain (Western Ontario and McMaster Universities Osteoarthritis Index‐pain subscale) sociodemographic variables, and comorbidities (body mass index and Functional Comorbidity Index) are the main explanatory variables.

Results

Participants' wake time was mainly sitting (11.0 h/day) in ≥60‐minute bouts (29.7% ± 12.7 of sitting time). Standing (3.4 hours/day) and stepping (1.4 h/day) primarily occurred in 0–5 minute bouts (standing: 87.7% ± 14.4 of standing time, stepping: 98.7% ± 12.7 of stepping time) and stepping cadence was predominantly incidental (1–19 spm; 52.9% ± 9.6 of total stepping time). Backward elimination model results indicated shorter medium‐to‐brisk cadence bout duration, older age, and higher pain significantly explained shorter 6MWT distance (AdjR2=0.24, p < .01).

Conclusions

Individuals with knee OA spend most of their waking hours sitting, while standing and stepping occurs in short bouts at very low stepping cadence. Decreased time in high stepping cadence is associated with lower functional capacity. Future studies should explore if increasing the daily time spent in higher step cadence can improve functional capacity in this population.
Retrospective on the risk matrix, part 1
Authors: Moseman James A.
Published: October 2023

A review of historic mathematical, risk, and engineering science information was conducted to find the roots of the risk matrix. The objective was to locate and evaluate information surrounding its use. A three‐tiered (low, medium, high) system is historical, if not biologically programmed into human physiology. The Risk Matrix is a Likert preference system that has migrated into engineering and science. No testing or mathematical foundation was found.
Nanoplatelet Superlattices by Tin‐Induced Transformation of FAPbI3 Nanocrystals
Authors: Hazra Vishwadeepa , Mondal Sudipta , Pattanayak Pradip , Bhattacharyya Sayan
Published: October 2023

The transition from 3D to 2D lead halide perovskites is traditionally led by the lattice incorporation of bulky organic cations. However, the transformation into a coveted 2D superlattice‐like structure by cationic substitution at the Pb2+ site of 3D perovskite is unfamiliar. It is demonstrated that the gradual increment of [Sn2+] alters the FASnxPb1−xI3 nanocrystals into the Ruddlesden–Popper‐like nanoplatelets (NPLs), with surface‐absorbed oleic acid (OA) and oleylamine (OAm) spacer ligand at 80 °C (FA+: formamidinium cation). These NPLs are stacked either by a perfect alignment to form the superlattice or by offsetting the NPL edges because of their lateral displacements. The phase transition occurs from the Sn/Pb ratio ≥0.011, with 0.64 wt% of Sn2+ species. At and above Sn/Pb = 0.022, the NPL superlattice stacks start to grow along [00l] with a repeating length of 4.37(3) nm, comprising the organic bilayer and the inorganic block having two octahedral layers (n = 2). Besides, a photoluminescence quantum yield of 98.4% is obtained with Sn/Pb = 0.011 (n ≥ 4), after surface passivation by trioctylphosphine (TOP).
Upscaled Synthesis Protocol for Phase‐Pure, Colloidally Stable MXenes with Long Shelf Lives
Authors: Goossens Nick , Lambrinou Konstantina , Tunca Bensu , Kotasthane Vrushali , Rodríguez González Miriam C. , Bazylevska Anastasiia , Persson Per O. Å. , De Feyter Steven , Radovic Miladin , Molina‐Lopez Francisco , Vleugels Jozef
Published: October 2023

MXenes are electrically conductive 2D transition metal carbides/nitrides obtained by the etching of nanolaminated MAX phase compounds, followed by exfoliation to single‐ or few‐layered nanosheets. The mainstream chemical etching processes have evolved from pure hydrofluoric acid (HF) etching into the innovative “minimally intensive layer delamination” (MILD) route. Despite their current popularity and remarkable application potential, the scalability of MILD‐produced MXenes remains unproven, excluding MXenes from industrial applications. This work proposes a “next‐generation MILD” (NGMILD) synthesis protocol for phase‐pure, colloidally stable MXenes that withstand long periods of dry storage. NGMILD incorporates the synergistic effects of a secondary salt, a richer lithium (Li) environment, and iterative alcohol‐based washing to achieve high‐purity MXenes, while improving etching efficiency, intercalation, and shelf life. Moreover, NGMILD comprises a sulfuric acid (H2SO4) post‐treatment for the selective removal of the Li3AlF6 impurity that commonly persists in MILD‐produced MXenes. This work demonstrates the upscaled NGMILD synthesis of (50 g) phase‐pure Ti3C2Tz MXene clays with high extraction yields (>22%) of supernatant dispersions. Finally, NGMILD‐produced MXene clays dry‐stored for six months under ambient conditions experience minimal degradation, while retaining excellent redispersibility. Overall, the NGMILD protocol is a leap forward toward the industrial production of MXenes and their subsequent market deployment.
Anomalous Impact of Mechanochemical Treatment on the Na‐ion Conductivity of Sodium Closo‐Carbadodecaborate Probed by X‐Ray Raman Scattering Spectroscopy
Authors: Gulino Valerio , Longo Alessandro , de Kort Laura M. , Rodenburg Hendrik P. , Murgia Fabrizio , Brighi Matteo , Černý Radovan , Sahle Christoph J. , Sundermann Martin , Gretarsson Hlynur , de Groot Frank , Ngene Peter
Published: October 2023

Solid‐state sodium ion conductors are crucial for the next generation of all‐solid‐state sodium batteries with high capacity, low cost, and improved safety. Sodium closo‐carbadodecaborate (NaCB11H12) is an attractive Na‐ion conductor owing to its high thermal, electrochemical, and interfacial stability. Mechanical milling has recently been shown to increase conductivity by five orders of magnitude at room temperature, making it appealing for application in all‐solid‐state sodium batteries. Intriguingly, milling longer than 2 h led to a significant decrease in conductivity. In this study, X‐ray Raman scattering (XRS) spectroscopy is used to probe the origin of the anomalous impact of mechanical treatment on the ionic conductivity of NaCB11H12. The B, C, and Na K‐edge XRS spectra are successfully measured for the first time, and ab initio calculations are employed to interpret the results. The experimental and computational results reveal that the decrease in ionic conductivity upon prolonged milling is due to the increased proximity of Na to the CB11H12 cage, caused by severe distortion of the long‐range structure. Overall, this work demonstrates how the XRS technique, allowing investigation of low Z elements such as C and B in the bulk, can be used to acquire valuable information on the electronic structure of solid electrolytes and battery materials in general.