bluuebunny/crossref_metadata_2025 huggingface dataset:
Space weathering simulation of micrometeorite bombardment on silicates and their mixture for space application
Authors: Weber Iris , Böttger Ute , Hanke Franziska , Reitze Max P. , Heeger Marcel , Adolphs Thorsten , Arlinghaus Heinrich F.
Published: June 2021

Missions to planetary bodies require innovative techniques for the in situ investigation of their surfaces, especially when landings are planned. Therefore, Raman spectroscopy as an excellent laboratory tool for rapid mineralogical analysis of both terrestrial and extraterrestrial rocks has been successfully proposed for the investigation of planetary surfaces. Examples are the Raman laser spectrometer (RLS) of the joint ESA and Roscosmos mission ExoMars 2022 as well as Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) and SuperCam onboard NASA's Mars2020 Perseverance Rover; another is the Raman spectrometer for Martian Moons eXploration (MMX) (RAX), which is being developed for the in situ exploration of the Mars' moon Phobos. When preparing such space missions, it is essential to be prepared for all possible outcomes, such as samples exhibiting space weathering (SW). In this work, we study the influence of micrometeorite bombardment on bodies without atmosphere as one trigger of SW. This type of SW effect is simulated with an excimer laser irradiating the investigated samples with an energy density of ~2.5 J/cm2 for each pulse. As possible components on Phobos, we investigated the silicates olivine (Fo91) and pyroxene (En87) and their mixtures with Raman spectroscopy before and after laser irradiation. Surprisingly, the characteristic Raman bands of the individual minerals in the spectra are not influenced by this kind of SW. On the other hand, the fluorescence‐dominated background signal induced by laser irradiation is reduced, possibly due to the formation of nanophase Fe, which then facilitates a better interpretation of the individual mineral peaks.
Effects of defect action level of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) fragments on quality of wheat flour
Authors: Negi Aditi , Pare Akash , Manickam Loganathan , Rajamani Meenatchi
Published: June 2021

BACKGROUND

Tribolium castaneum (Herbst) is one of the most important secondary storage pests of all types of flour and flour‐based products. The present study focuses on the fragment producing behaviour of T. castaneum in wheat flour during storage and its effect on the quality parameters and defect action level (DAL) of fragments. The US Food and Drug Administration has set a DAL of 75 insect fragments in 50 g of flour. Box–Behnken design was used to optimize the storage conditions (storage period in days and temperature in degrees Celsius) and insect density (numbers) to keep insect fragments below the DAL.

RESULTS

Optimization results indicated that the presence of single number of adult of T. castaneum is enough to cross the DAL of insect fragments within a storage period of 21 days at a storage temperature of 30 °C. Insect fragments cause perceptible changes in the quality of wheat flour. When sample attained DAL of T. castaneum fragments in wheat flour,the various quality parameters were analysed in that moisture content of wheat flour was 10.8 ± 0.26%, total colour change was 2.052 (ΔE value), T. castaneum progeny emergence was 19.66 ± 1, uric acid was 1.8 ± 0.16 g kg−1 and microbial count was 7.34 ± 0.5 cfu g−1.

CONCLUSIONS

Results from the present study indicate that the presence of even a single adult of stored pest in wheat flour should not be ignored. It is mandatory to determine the threshold level and frequent sampling is required to achieve zero tolerance of stored product insects in food commodities. © 2021 Society of Chemical Industry.
Preparative separation of gypenoside XVII, ginsenoside Rd2, and notoginsenosides Fe and Fd from Panax notoginseng leaves by countercurrent chromatography and orthogonality evaluation for their separation
Authors: Sun Hengmian , Ma Li‐Juan , Wan Jian‐Bo , Tong Shengqiang
Published: June 2021

The minor ginsenosides with less polarity may have more potent biological activities. Four minor saponins, i.e., gypenoside XVII, ginsenoside Rd2, notoginsenoside Fe, and notoginsenoside Fd, were successfully separated from Panax notoginseng leaves (PNL) after biotransformation by one‐step countercurrent chromatography using the biphasic solvent system consisting of n‐butanol–ethyl acetate–water (1:4:5, v/v/v). 30 mg of the refined extract of PNL produced 1 mg of gypenoside XVII, 4 mg of notoginsenoside Fe, 2.5 mg of ginsenoside Rd2, and 8.4 mg of notoginsenoside Fd, with purity of 74.9, 95.2, 87.3, and 97.6%, respectively. Besides, orthogonality evaluation for the separation of the four saponins using countercurrent chromatography and liquid chromatography was discussed. Four minor saponins were successfully separated from each other on a preparative scale by countercurrent chromatography from PNL, which will facilitate to provide ample of these minor saponins for further pharmacological studies.
Novel Approach to Ultrasound‐Guided Thoracostomy
Authors: Taylor Lindsay A. , Stenberg Robert , Tozer Jordan , Vitto Michael J. , Joyce Michael , Jennings Jason , Carpenter Christopher L. , Fuchs Robert , Deuell Zachary , Evans David P.
Published: June 2021

Objectives

Thoracostomy is often a required treatment in patients with thoracic trauma; however, performing a thoracostomy using traditional techniques can have complications. Ultrasound can be a beneficial tool for identifying the correct thoracostomy insertion site. We designed a randomized prospective study to assess if ultrasound guidance can improve thoracostomy site identification over traditional techniques.

Methods

Emergency medicine residents were randomly assigned to use palpation or ultrasound to identify a safe insertion site for thoracostomy placement. The target population comprised of hemodynamically stable trauma patients who received an extended focused assessment with sonography for trauma (EFAST) and a chest computed tomography (CT) exam. The resident placed a radiopaque marker on the skin of the patient where a safe intercostal space was believed to be located, either by palpation or ultrasound. Clinical ultrasound faculty reviewed the CT to confirm marker placement relative to the diaphragm. A Fischer's exact test was used to analyze the groups.

Results

One hundred and forty‐seven patients were enrolled in the study, 75 in the ultrasound group and 72 in the landmark group. This resulted in the placement of 271 total thoracostomy site markers, 142 by ultrasound and 129 by palpation and landmarks. The ultrasound group correctly identified thoracostomy insertion sites above the diaphragm in 97.2% (138/142) of patients, while the palpation group identified a safe insertion site in 88.4% (114/129) of patients (P = .0073).

Conclusion

This study found that emergency medicine residents are more likely to identify a safe tube thoracostomy insertion site in trauma patients by using ultrasound, as compared to using landmarks and palpation.
Long‐Term Facial Nerve Outcome in Primary Parotid Cancer Surgery: A Population‐Based Analysis
Authors: Thielker Jovanna , Wahdan Ali , Buentzel Jens , Kaftan Holger , Boeger Daniel , Mueller Andreas H. , Wittig Andrea , Schultze‐Mosgau Stefan , Ernst Thomas , Guntinas‐Lichius Orlando
Published: June 2021

Objectives/Hypothesis

To determine immediate postoperative and long‐term facial nerve dysfunction after parotid cancer surgery, risk factors, and the role of facial reanimation surgery.

Study Design

Population‐based long‐term analysis for all new primary parotid carcinoma cases in Thuringia from 1996 to 2019.

Methods

Data of the cancer registries of Thuringia, a federal state in Germany, were analyzed in combination with hospital‐based data on facial function.

Results

About 477 patients (42.3% women; median age: 68 years) were included. It was observed that 6.7% had a preoperative facial nerve dysfunction, 11.7% received a radical parotidectomy, that is, that 5% had a normal preoperative facial function but needed radical surgery because of intraoperative detection of tumor infiltration into the facial nerve. About 10.2% received facial nerve reconstruction surgery. Immediate postoperative facial nerve dysfunction in the other patients was observed in 34.4% of the patients. Advanced T classification (odds ratio [OR] = 2.140; confidence interval [CI] = 1.268–3.611; P = .004) and neck dissection (OR = 2.012; CI = 1.027–3.940; P = .041) were independent risk factors for immediate postoperative facial nerve dysfunction. In addition, 22.0% showed no recovery during follow‐up. Advanced T classification (OR = 2.177; CI = 1.147–4.133; P = .017) and postoperative radiotherapy (OR = 2.695; CI = 1.244–5.841; P = .012) were independent risk factors for permanent postoperative facial nerve dysfunction.

Conclusion

Patients with primary parotid cancer are at high risk for long‐term facial nerve dysfunction. It seems that the possibilities of facial reanimation surgery needs to be utilized even more effectively.

Level of Evidence

3 Laryngoscope, 131:2694–2700, 2021
Safety practices for in‐office laryngology procedures during clinical reintroduction amidst COVID‐19
Authors: Calcagno Haley , Anthony Benjamin P. , Halum Stacey L. , Parker Noah P.
Published: June 2021

Objective

Describe safety practices for performing in‐office laryngology procedures during clinical re‐introduction amidst the coronavirus disease 2019 (COVID‐19) pandemic.

Methods

An anonymous survey in Qualtrics was created to evaluate demographics, preprocedure testing, practice settings, anesthesia, and personal protective equipment (PPE) use for five procedure categories (non‐mucosal‐traversing injections, mucosal‐traversing injections, endoscopy without suction, endoscopy with suction/mucosal intervention via working channel, and laser via working channel). The survey was emailed to the Fall Voice Community on Doc Matter and to members of the American Broncho‐Esophagological Association (ABEA) from May to June 2020.

Results

Eighty‐two respondents were analyzed (response rate: 10%). Respondents represented diverse locations, including international. Most reported academic (71%) or private practices (16%), laryngology fellowship training (76%), and a significant practice devotion to laryngology and broncho‐esophagology. During the early re‐introduction, most continued to perform all procedure categories. The office was preferred to the OR setting for most, though 36% preferred the OR for laser procedures. There was a preference for preprocedural SARS‐Cov2 testing for procedures involving a working channel (>67%), and these procedures had the highest proportion of respondents discontinuing the procedure due to COVID‐19. Various types of topical anesthesia were reported, including nebulizer treatments. The most common forms of personal protective equipment utilized were gloves (>95%) and N95 masks (>67%). Powered‐air purifying respirators and general surgical masks were used infrequently.

Conclusions

During the early re‐introduction, respondents reported generally continuing to perform office laryngology procedures, while greater mucosal manipulation affected decisions to stop procedures due to COVID‐19, perform preprocedural SARS‐Cov2 testing, and alter topical anesthesia. Gloves and N95 masks were the predominate PPE.

Level of Evidence

N/A.
An Olefin Copolymer with Aggregation‐Induced Emission Characteristics Synthesized by Using Metallocene Catalyst
Authors: Wang Wei , Ji Wenxi , Hou Liping , Li Juan , Du Wenjie , Ren Minqiao , Zhang Taoyi
Published: June 2021

Copolymerization of ethylene with (2‐(4‐vinylphenyl)ethene‐1,1,2‐triyl) tribenzene is conducted by using a metallocene catalyst, giving an ethylene copolymer containing tetraphenylethene unit. The result of NMR shows that the tetraphenylethene unit is distributed in isolation in the polymer chain, and the melting point of the copolymer decreases linearly with the increase of the comonomer incorporation. The copolymer can emit blue fluorescence under ultraviolet light, and the intensity increases with the increase of the comonomer incorporation. The fluorescence of flakes made of the copolymer gradually becomes weaker when the temperature is raised. When the temperature is higher than the melting point of the copolymer, the fluorescence is almost invisible.
Demethylzeylasteral inhibits proliferation, migration, and invasion through FBXW7/c‐Myc axis in gastric cancer
Authors: Li Yongsen , Su Yongyue , Zhao Yuzu , Hu Xiaosong , Zhao Gaichao , He Jiang , Wan Sicheng , Lü Muhan , Cui Hongjuan
Published: June 2021

Gastric cancer (GC) is one of the most familiar malignancy in the digestive system. Demethylzeylasteral (Dem), a natural functional monomer extracted from Tripterygium wilfordii Hook F, shows anti‐tumor effects in a variety of cancers, including GC, however, with the underlying mechanism poorly understood. In our study, we show that Dem inhibits the proliferation, migration, and invasion of GC cells, which are mediated by down‐regulating c‐Myc protein levels. Mechanistically, Dem reduces the stability of c‐Myc by up‐regulating FBXW7, an E3 ubiquitin ligase. Moreover, in xenograft tumor model experiment, Dem also inhibits GC, which depends on suppressing c‐Myc expression. Finally, Dem enhances GC cell chemosensitivity to the combination treatment of 5‐Fluorouracil (5‐Fu) and doxorubicin (DOX) in vitro. Together, Dem exerts anti‐neoplastic activities through destabilizing and suppressing c‐Myc, establishing a theory foundation for using it in future treatment of GC.
A novel pathogenic splice site variation in STK11 gene results in Peutz–Jeghers syndrome
Authors: Zhao Na , Wu Huizhi , Li Ping , Wang Yuxian , Dong Li , Xiao Han , Wu Changxin
Published: June 2021

Background

Peutz–Jeghers syndrome (PJS) is a rare autosomal dominantly inherited disease resulting in multiple gastrointestinal hamartomatous polyps, mucocutaneous pigmentation, and an increased risk of various types of cancer, and is caused by variations in the serine/threonine protein kinase STK11 (LKB1).

Methods

STK11 gene variations were identified by analyzing STK11 cDNA and genomic DNA. Minigenes carrying the wild‐type and mutant sequences were subjected to in vitro splicing assay to dissect the features of these mutations. The different distribution of wild‐type and mutant protein in cells were tested by Immunofluorescence assays and the functional analysis of the variation were performed using Western blot.

Results

A novel heterozygous splice‐acceptor site variation (c.921‐2 A>C) in intron 7 of the STK11 gene which is co‐segregates with the PJS phenotypes in the proband and all the affected family members and three previously reported variations (c.180C>G, c.580G>A, c.787_790del) were identified in the four families. The c.921‐2 A>C substitution resulted in the inactivation of a splice site and the utilization of a cryptic splice acceptor site surrounding exon 8, generating three different aberrant RNA transcripts, leading to frameshift translation and protein truncation. The results of minigenes indicated that the spliceosome can use a variety of 3’ acceptor site sequences to pair with a given 5’ donor site. The immunofluorescent visualization showed that the distribution of mutant STK11 was different from that of wild‐type STK11, suggesting the mutation may be the causative effect on the dysfunction of the mutant protein. The rescue experiments indicated that the failure of suppressing mTOR phosphorylation by shRNA STK11 could be eliminated by supply of wild‐type STK11 rather than mutant STK11.

Conclusion

We identified a novel heterozygous mutation (c.921‐2 A>C) in the STK11 in a Chinese PJS family. Haploinsufficiency of STK11 might contribute to the pathogenesis of the disease.
fastCAT: Fast cone beam CT (CBCT) simulation
Authors: O'Connell Jericho , Bazalova‐Carter Magdalena
Published: June 2021

Purpose

To develop fastCAT, a fast cone‐beam computed tomography (CBCT) simulator. fastCAT uses pre‐calculated Monte Carlo (MC) CBCT phantom‐specific scatter and detector response functions to reduce simulation time for megavoltage (MV) and kilovoltage (kV) CBCT imaging.

Methods

Pre‐calculated x‐ray beam energy spectra, detector optical spread functions and energy deposition, and phantom scatter kernels are combined with GPU raytracing to produce CBCT volumes. MV x‐ray beam spectra are simulated with EGSnrc for 2.5‐ and 6 MeV electron beams incident on a variety of target materials and kV x‐ray beam spectra are calculated analytically for an x‐ray tube with a tungsten anode. Detectors were modeled in Geant4 extended by Topas and included optical transport in the scintillators. Two MV detectors were modeled—a standard Varian AS1200 GOS detector and a novel CWO high detective quantum efficiency detector. A kV CsI detector was also modeled. Energy‐dependent scatter kernels were created in Topas for two 16 cm diameter phantoms: A Catphan 515 contrast phantom and an anthropomorphic head phantom. The Catphan phantom contained inserts of 1–5 mm in diameter of six different tissue types: brain, deflated lung, compact and cortical bone, adipose, and B‐100.

Results

fastCAT simulations retain high fidelity to measurements and MC simulations: MTF curves were within 3.5% and 1.2% of measured values for the CWO and GOS detectors, respectively. HU values and CNR in a fastCAT Catphan 515 simulation were seen to be within 95% confidence intervals of an equivalent MC simulation for all of the tissues with root mean squared errors less than 16 HU and 1.6 in HU values and CNR comparisons, respectively. The anthropomorphic head phantom CWO detector CBCT image resulted in much higher tissue contrast and lower noise compared to the GOS detector CBCT image. A fastCAT simulation of the Catphan 515 module with an image size of 1024  1024  10 voxels took 61 s on a GPU while the equivalent Topas MC was estimated to take more than 0.3 CPU years.

Conclusions

We present an open source fast CBCT simulation with high fidelity to MC simulations. The fastCAT python package can be found at https://github.com/jerichooconnell/fastCAT.git.
Simultaneous 15N polarization of several biocompatible substrates in ethanol–water mixtures by signal amplification by reversible exchange (SABRE) method
Authors: Kiryutin Alexey S. , Yurkovskaya Alexandra V. , Petrov Pavel A. , Ivanov Konstantin L.
Published: June 2021

Signal amplification by reversible exchange (SABRE) is a popular method for generating strong signal enhancements in nuclear magnetic resonance (NMR). In SABRE experiments, the source of polarization is provided by the nonthermal spin order of parahydrogen (pH2, the H2 molecule in its nuclear singlet spin state). Polarization formation requires that both pH2 and a substrate molecule bind to an Ir‐based complex where polarization transfer occurs. Subsequently, the complex dissociates and free polarized substrate molecules are formed. In this work, we present approaches towards biocompatible SABRE, meaning that several small biomolecules are simultaneously polarized by using the SABRE method in water–ethanol solutions at room temperature. We are able to demonstrate significant 15N‐NMR signal enhancements in water–ethanol solutions for biomolecules like nicotinamide, metronidazole, adenosine‐5′‐monophosphate, and 4‐methylimidazole and found that the first three substrates are polarized at the same level as a well‐known pyridine. We show that simultaneous polarization of several molecules is indeed feasible when the reactions are carried out at an ultralow field of about 400–500 nT. The achieved enhancements are between 100‐fold and 15,000‐fold. The resulting 15N polarization (maximal value about 4% achieved for metronidazole and pyridine at 45°C) strongly depends on the sample temperature, pH2 bubbling pressure, and pH2 flow. One more parameter, which is important for optimizing the enhancement, is the solvent pH. Hence, this study presents a step in developing biocompatible SABRE polarization and gives a clue on how such SABRE experiments should be optimized to achieve the highest NMR signal enhancement.
Electric field calculation and peripheral nerve stimulation prediction for head and body gradient coils
Authors: Roemer Peter B. , Wade Trevor , Alejski Andrew , McKenzie Charles A. , Rutt Brian K.
Published: June 2021

Purpose

To demonstrate and validate electric field (E‐field) calculation and peripheral nerve stimulation (PNS) prediction methods that are accurate, computationally efficient, and that could be used to inform regulatory standards.

Methods

We describe a simplified method for calculating the spatial distribution of induced E‐field over the volume of a body model given a gradient coil vector potential field. The method is easily programmed without finite element or finite difference software, allowing for straightforward and computationally efficient E‐field evaluation. Using these E‐field calculations and a range of body models, population‐weighted PNS thresholds are determined using established methods and compared against published experimental PNS data for two head gradient coils and one body gradient coil.

Results

A head‐gradient‐appropriate chronaxie value of 669 µs was determined by meta‐analysis. Prediction errors between our calculated PNS parameters and the corresponding experimentally measured values were ~5% for the body gradient and ~20% for the symmetric head gradient. Our calculated PNS parameters matched experimental measurements to within experimental uncertainty for 73% of ∆Gmin estimates and 80% of SRmin estimates. Computation time is seconds for initial E‐field maps and milliseconds for E‐field updates for different gradient designs, allowing for highly efficient iterative optimization of gradient designs and enabling new dimensions in PNS‐optimal gradient design.

Conclusions

We have developed accurate and computationally efficient methods for prospectively determining PNS limits, with specific application to head gradient coils.
Understanding and Enhancing Angler Satisfaction with Fisheries Management: Insights from the “Great Red Snapper Count”
Authors: Scyphers Steven B. , Drymon J. Marcus , Furman Kelsi L. , Conley Elizabeth , Niwa Yvette , Jefferson Amanda E. , Stunz Gregory W.
Published: June 2021

Management of Gulf of Mexico Red Snapper Lutjanus campechanus has been a topic of much scientific debate and intensive public scrutiny. In response to political, public, and management desires for more robust data on Red Snapper populations, a gulfwide initiative commonly referred to as the “Great Red Snapper Count” (GRSC) was funded to estimate the absolute abundance of Red Snapper in the U.S. Gulf of Mexico. Here, we describe the results of an online survey designed to (1) characterize the social dimensions of Red Snapper anglers, (2) measure satisfaction with current Red Snapper populations and regulations, (3) assess overall patterns of awareness of the GRSC, and (4) evaluate the potential benefits of GRSC stakeholder engagement videos. A key finding of our survey was that awareness of the GRSC was associated with up to three times higher satisfaction with fisheries management. Through an in-survey experiment, we found that anglers that were presented a video on specific GRSC project components reported slightly higher management satisfaction than those presented an overview video or no video. Collectively, our results indicate that angler awareness, when underpinned by effective engagement and outreach activities, can enhance angler satisfaction.
A review concerning the main factors that interfere in the electrical percolation threshold content of polymeric antistatic packaging with carbon fillers as antistatic agent
Authors: Vieira Leonardo de Souza , dos Anjos Erick Gabriel Ribeiro , Verginio Gleice Ellen Almeida , Oyama Isabela Cesar , Braga Natália Ferreira , da Silva Thaís Ferreira , Montagna Larissa Stieven , Passador Fabio Roberto
Published: June 2021

The use of high contents of carbon fillers in polymeric composites may decrease the mechanical properties of the polymeric matrices, as well as reduce their processability and increase the production costs of antistatic packaging used in the electronic industry. Therefore, it is of great technological interest the research on alternative approaches to produce polymer composites with low electrical percolation threshold. In this way, this review article focuses on the discussion of the main factors that interfere in the electrical percolation threshold of electrically conductive polymer composites, such as the aspect ratio of the carbon fillers and its particle size, the compatibility between the composite phases, the crystallinity degree of the polymeric matrix, the processing route and the location of fillers in multi‐phase polymer blends. Additionally, the review article reports the latest studies related to the obtainment of polymer composites with low percolation threshold contents and produced with different types of carbon fillers.
Long‐term effectiveness and safety of bladder augmentation in spina bifida patients
Authors: Romero‐Maroto Jesús , Martinez‐Cayuelas Laura , Gómez‐Pérez Luis , Sarrió‐Sanz Pau , Olarte Barragán Edgar , López‐López Ana Isabel
Published: June 2021

Aims

To establish the long‐term efficacy and safety of bladder augmentation in spina bifida patients.

Material and Methods

Sixteen patients were operated on using the Bramble technique. Preoperative and postoperative evaluation included clinical history, blood tests, urine cultures, cystography, pyelography, ultrasound, and filling cystometry. In the final review a standardized quality of life questionnaire was applied.

Results

Median follow‐up was 20 years (15–26). Kidney function was stabilized except for one case that required a kidney transplant. Hydronephrosis disappeared or improved (p = 0.03). Vesicoureteral reflux grades I–II was cured without reimplantation and grades III‐IV responded better with reimplantation than without (p = 0.03). Quality of life improved in all patients, with all stating they would undergo the procedure again. After surgery, 94% of the patients exhibited diurnal continence but 25% exhibited nocturnal incontinence. Pressure at capacity decreased and bladder capacity increased (p < 0.001). One patient presented ureteral fistula with another presenting hemorrhage. Both required immediate surgical review. Late complications included urinary sphincter cuff erosion, renal lithiasis, four instances of bladder lithiasis and repeated pyelonephritis in one 24‐year‐old patient. All required surgery. The mean of urinary infections fell, from 2.5 per year (0.7) to 1 (0.5) (p = 0.03).

Conclusion

Augmentation cystoplasty (AC) maintains its efficacy and improves quality of life in the long term. However, serious surgical complications can ensue, along with minor or major subsequent complications. This should be considered before surgery and makes lifelong monitoring of patients necessary.
Oxygen‐enhanced functional lung imaging using a contemporary 0.55 T MRI system
Authors: Bhattacharya Ipshita , Ramasawmy Rajiv , Javed Ahsan , Chen Marcus Y. , Benkert Thomas , Majeed Waqas , Lederman Robert J. , Moss Joel , Balaban Robert S. , Campbell‐Washburn Adrienne E.
Published: June 2021

The purpose of this study was to evaluate oxygen‐enhanced pulmonary imaging at 0.55 T with 3D stack‐of‐spirals ultrashort‐TE (UTE) acquisition. Oxygen‐enhanced pulmonary MRI offers the measurement of regional lung ventilation and perfusion using inhaled oxygen as a contrast agent. Low‐field MRI systems equipped with contemporary hardware can provide high‐quality structural lung imaging by virtue of the prolonged T2*. Fortuitously, the T1 relaxivity of oxygen increases at lower field strengths, which is expected to improve the sensitivity of oxygen‐enhanced lung MRI. We implemented a breath‐held T1‐weighted 3D stack‐of‐spirals UTE acquisition with a 7 ms spiral‐out readout. Measurement repeatability was assessed using five repetitions of oxygen‐enhanced lung imaging in healthy volunteers (n = 7). The signal intensity at both normoxia and hyperoxia was strongly dependent on lung tissue density modulated by breath‐hold volume during the five repetitions. A voxel‐wise correction for lung tissue density improved the repeatability of percent signal enhancement maps (coefficient of variation = 34 ± 16%). Percent signal enhancement maps were compared in 15 healthy volunteers and 10 patients with lymphangioleiomyomatosis (LAM), a rare cystic disease known to reduce pulmonary function. We measured a mean percent signal enhancement of 9.0 ± 3.5% at 0.55 T in healthy volunteers, and reduced signal enhancement in patients with LAM (5.4 ± 4.8%, p = 0.02). The heterogeneity, estimated by the percent of lung volume exhibiting low enhancement, was significantly increased in patients with LAM compared with healthy volunteers (11.1 ± 6.0% versus 30.5 ± 13.1%, p = 0.01), illustrating the capability to measure regional functional deficits.
Brain metabolism in tau and amyloid mouse models of Alzheimer's disease: An MRI study
Authors: Wei Zhiliang , Xu Jiadi , Chen Lin , Hirschler Lydiane , Barbier Emmanuel L. , Li Tong , Wong Philip C. , Lu Hanzhang
Published: June 2021

Alzheimer's disease (AD) is the leading cause of cognitive impairment and dementia in elderly individuals. According to the current biomarker framework for “unbiased descriptive classification”, biomarkers of neurodegeneration, “N”, constitute a critical component in the tri‐category “A/T/N” system. Current biomarkers of neurodegeneration suffer from potential drawbacks such as requiring invasive lumbar puncture, involving ionizing radiation, or representing a late, irreversible marker. Recent human studies have suggested that reduced brain oxygen metabolism may be a new functional marker of neurodegeneration in AD, but the heterogeneity and the presence of mixed pathology in human patients did not allow a full understanding of the role of oxygen extraction and metabolism in AD. In this report, global brain oxygen metabolism and related physiological parameters were studied in two AD mouse models with relatively pure pathology, using advanced MRI techniques including T2‐relaxation‐under‐spin‐tagging (TRUST) and phase contrast (PC) MRI. Additionally, regional cerebral blood flow (CBF) was determined with pseudocontinuous arterial spin labeling. Reduced global oxygen extraction fraction (by −18.7%,p = 0.008), unit‐mass cerebral metabolic rate of oxygen (CMRO2) (by −17.4%,p = 0.04) and total CMRO2(by −30.8%,p < 0.001) were observed in Tau4RΔK mice—referred to as the tau AD model—which manifested pronounced neurodegeneration, as measured by diminished brain volume (by −15.2%,p < 0.001). Global and regional CBF in these mice were not different from those of wild‐type mice (p > 0.05), suggesting normal vascular function. By contrast, in B6;SJL‐Tg [APPSWE]2576Kha (APP) mice—referred to as the amyloid AD model—no brain volume reduction, as well as relatively intact brain oxygen extraction and metabolism, were found (p > 0.05). Consistent with the imaging data, behavioral measures of walking distance were impaired in Tau4RΔK mice (p = 0.004), but not in APP mice (p = 0.88). Collectively, these findings support the hypothesis that noninvasive MRI measurement of brain oxygen metabolism may be a promising biomarker of neurodegeneration in AD.
Analysis of COVID‐19 and comorbidity co‐infection model with optimal control
Authors: Omame Andrew , Sene Ndolane , Nometa Ikenna , Nwakanma Cosmas I. , Nwafor Emmanuel U. , Iheonu Nneka O. , Okuonghae Daniel
Published: June 2021

In this work, we develop and analyze a mathematical model for the dynamics of COVID‐19 with re‐infection in order to assess the impact of prior comorbidity (specifically, diabetes mellitus) on COVID‐19 complications. The model is simulated using data relevant to the dynamics of the diseases in Lagos, Nigeria, making predictions for the attainment of peak periods in the presence or absence of comorbidity. The model is shown to undergo the phenomenon of backward bifurcation caused by the parameter accounting for increased susceptibility to COVID‐19 infection by comorbid susceptibles as well as the rate of reinfection by those who have recovered from a previous COVID‐19 infection. Simulations of the cumulative number of active cases (including those with comorbidity), at different reinfection rates, show infection peaks reducing with decreasing reinfection of those who have recovered from a previous COVID‐19 infection. In addition, optimal control and cost‐effectiveness analysis of the model reveal that the strategy that prevents COVID‐19 infection by comorbid susceptibles is the most cost‐effective of all the control strategies for the prevention of COVID‐19.
Wet Conditions, Complications Challenge Wastewater Treatment Plant Upgrade
Authors: Pfeuffer Chris , Amsler Brian
Published: June 2021

Effective teamwork and technology selection ensured successful project delivery for a complicated wastewater system upgrade under challenging conditions.
In situ fibrillation‐reinforced polypropylene‐based multi‐component foams
Authors: Wu Gaojian , Xu Yuxuan , Chen Junxiang , Dang Kaifang , Yang Weimin , Xie Pengcheng
Published: June 2021

Recent trends in energy and environmental protection have led to many studies of high‐performance microcellular foams. Polymer blends provide an effective way to improve foamability, microstructure, and performance versus single component thermoplastics. However, challenges remain for morphological control of polymer blends because the reinforcing effect depends upon the morphology of the dispersed phase. In this work, we present a feasible method for attaining microfibrils with high aspect ratios based on the in situ fibrillation of immiscible polymers to improve the morphology and distribution of the blend phase and improve the microcellular structure and mechanical properties of composite foams. Composite foams of polypropylene (PP)/thermoplastic polyester elastomer (TPEE)/polytetrafluoroethylene (PTFE) were fabricated, which were the polymer matrix, blend phase, and in situ fibrillation phase, respectively. The presence of PTFE and its effect on crystallization, rheology behavior, cellular structure, and mechanical properties were investigated. The results showed that PTFE microfibrils can promote melt strength, crystallization, and rheology properties. Thus, the multi‐composite foams achieve improved microcellular structure and mechanical properties, and improvements in these properties indicate the positive effects of an in situ fibrillation phase on the polymer blend foams.
Physicochemical Parameters of Insensitive Munition Constituent Methylnitroguanidine (MeNQ) of Importance to Environmental Fate and Transport
Authors: George Garrett W. , Jones Stacy J. , Buchanan J. Paige , Cuddy Michael , Alberts Erik M. , Crouch Rebecca , Thornell Travis L. , Moores Lee C.
Published: June 2021

1‐methyl‐3‐nitroguandine (MeNQ) is being pursued as an insensitive munition to replace legacy munitions such as TNT and RDX. This study was intended to determine the basic physicochemical properties of MeNQ as well as potential environmental fate pathways. The solubility of MeNQ was determined to be 12.92±0.52 g/L and aqueous photolysis was found to efficiently degrade the munition, where its quantum yield and half‐life were found to be 0.009 and 0.59 days, respectively. Hydrolysis was an insignificant degradation pathway resulting in 8.1 % degradation at pH 4, 2.6 % at pH 7, and 6.2 % at pH 9 after five days at an elevated temperature. Volatilization at environmentally relevant conditions was found to be insignificant as the molecule thermally degrades, leading to an inability to calculate Henry's Constant for volatilization from water. Spectroscopic (UV‐vis, FTIR, NMR) and analytical (HPLC) studies were undertaken and are shown alongside the parent molecule, NQ, for comparison to characterize the emerging munition.
Pharmacometric analysis linking immunoglobulin exposure to clinical efficacy outcomes in chronic inflammatory demyelinating polyneuropathy
Authors: Tortorici Michael A. , Yuraszeck Theresa , Cornblath David , Bril Vera , Hartung Hans‐Peter , Sobue Gen , Lewis Richard A. , Merkies Ingemar S. J. , Lawo John‐Philip , Praus Michaela , Durn Billie L. , Mielke Orell , Ma Xuewen , Jauslin Petra , Pfister Marc , van Schaik Ivo N. ,   the PATH study group
Published: June 2021

The two main objectives of this analysis were to (i) characterize the relationship between immunoglobulin (Ig) exposure and chronic inflammatory demyelinating polyneuropathy (CIDP) disease severity using data from 171 patients with CIDP who received either subcutaneous Ig (IgPro20; Hizentra®) or placebo (PATH study), and to (ii) simulate and compare exposure coverage with various dosing approaches considering weekly dosing to be the reference dose. IgG pharmacokinetic (PK) parameters, including those from a previous population PK model, were used to predict individual IgG profile and exposure metrics. Treatment‐related changes in Inflammatory Neuropathy Cause and Treatment (INCAT) scores were best described by a maximum effect (Emax) model as a function of ΔIgG (total serum IgG at INCAT score assessment minus baseline IgG levels before intravenous Ig restabilization). Simulations indicate that flexible dosing from daily to biweekly (every other week) provide an exposure coverage equivalent to that of a weekly Ig dose.
Dielectric Relaxation Dynamics and Polaronic Tunneling Conduction Mechanism of Electrical Conductivity of Fe2O3‐Doped PbO–ZrO2–SiO2 Glass Ceramics
Authors: Chandrakala Ch. , Siva Sesha Reddy A. , Kostrzewa M. , Purnachand N. , Venkatramaiah N. , Naga Raju G. , Ravi Kumar V. , Veeraiah Nalluri
Published: June 2021

This study consists of comprehensive investigations on dielectric permittivity (ε′), electric moduli (M′, M″), impedance (Z), and conductivity (σac) spectra over broad regions of frequency and temperature of lead zirconium silicate glass ceramics mixed with different concentrations of Fe2O3. The observed increase in dielectric permittivity with the content of Fe2O3 is attributed to the increasing presence of iron ions in octahedral positions. Electric moduli plots with frequency (ω) and temperature (T) exhibit dipolar effects. These effects are quantitatively analyzed by Cole–Cole plots; the analysis indicates the distribution of relaxation times. Probable dipoles for these effects are identified and discussed. AC conductivity (σac) shows a rising trend with an increase in Fe2O3 beyond 0.2 mol%, and this increase is attributed to the polaron exchange among Fe2+ and Fe3+ ions. The conduction mechanism is well explained using a polaron tunneling model in the middle‐frequency and high‐temperature regions.
Bayesiansingle‐armphaseIItrial designs withtime‐to‐eventendpoints
Authors: Wu Jianrong , Pan Haitao , Hsu Chia‐Wei
Published: June 2021

For the cancer clinical trials with immunotherapy and molecularly targeted therapy, time‐to‐event endpoint is often a desired endpoint. In this paper, we present an event‐driven approach for Bayesian one‐stage and two‐stage single‐arm phase II trial designs. Two versions of Bayesian one‐stage designs were proposed with executable algorithms and meanwhile, we also develop theoretical relationships between the frequentist and Bayesian designs. These findings help investigators who want to design a trial using Bayesian approach have an explicit understanding of how the frequentist properties can be achieved. Moreover, the proposed Bayesian designs using the exact posterior distributions accommodate the single‐arm phase II trials with small sample sizes. We also proposed an optimal two‐stage approach, which can be regarded as an extension of Simon's two‐stage design with the time‐to‐event endpoint. Comprehensive simulations were conducted to explore the frequentist properties of the proposed Bayesian designs and an R packageBayesDesigncan be assessed via R CRAN for convenient use of the proposed methods.
An assessment of the efficacy and safety of dydrogesterone in women with ovarian endometrioma: An open‐label multicenter clinical study
Authors: Kitawaki Jo , Koga Kaori , Kanzo Takumi , Momoeda Mikio
Published: June 2021

Purpose

To assess the efficacy and safety of dydrogesterone in Japanese women with ovarian endometrioma in a real‐world setting.

Methods

The post‐marketing study involved 15 sites in Japan. Dydrogesterone 10 mg twice daily orally was administered for 21 days (day 5‐25 of each menstrual cycle) for 4 cycles. The primary outcome measure was the change in ovarian endometrioma volume from baseline. Secondary outcome measures included total dysmenorrhea score (0 = absent to 3 = severe), severity of dysmenorrhea pain [0‐10cm visual analog scale (VAS)], serum carbohydrate antigen 125 (CA‐125) levels, and safety.

Results

The study group comprised women with an endometrioma aged 20 to 49 (47.4% cases aged ≥40 years). Endometrioma volume was reduced in 50% (26/52), unchanged in 25% (13/52), and increased in 25% (13/52) of women from baseline to the end of cycle 5; three‐quarters of patients thus had either reduced or unchanged ovarian endometrioma volume. Dydrogesterone significantly reduced total dysmenorrhea scores and severity of dysmenorrhea pain VAS during treatment compared with baseline. CA‐125 levels were not significantly changed during the study. The incidence of adverse events and adverse drug reactions in 59 subjects was 13.6% and 11.9%.

Conclusions

Dydrogesterone prevented an increase in endometrioma size in many women, and it also significantly improved total dysmenorrhea scores and severity of dysmenorrhea pain, and was well tolerated. The ClinicalTrials.gov identifier of the study was NCT02921763.
Formation tracking for singular swarm systems subjected to energy constraints and switching transmission topologies
Authors: Xi Jianxiang , Wang Cheng , Li Hongyao , He Ming , Zhang Yanhong
Published: June 2021

This article investigates admissible formation tracking for singular swarm systems under conditions of switching transmission topologies as well as the limited energy supply, where both switching transmission topologies containing a spanning tree and switching transmission topologies containing a joint spanning tree are addressed. First, a new formation control tracking protocol with switching transmission topologies is proposed to realize admissible formation tracking, where the total energy supply is predetermined. Afterwards, by a dual nonsingular transformation, the disagreement dynamics between followers and the leader is determined and the impacts of asymmetric structures of switching transmission topologies are eliminated. Sufficient conditions for admissible formation tracking design and analysis for singular swarm systems with switching transmission topologies containing a spanning tree and with switching transmission topologies containing a joint spanning tree are proposed, respectively, where the coupling relationship matrix between the total energy supply and the matrix variable is determined. Finally, two numerical simulations are presented to demonstrate the effectiveness of theoretical results.
Sensor fault estimation based on the constrained zonotopic Kalman filter
Authors: Liu Zixing , Wang Ziyun , Wang Yan , Ji Zhicheng
Published: June 2021

For solving the additive and multiplicative sensor faults in the constrained system with unknown but bounded noise, the constrained zonotopic Kalman filter‐based additive sensor fault estimator and multiplicative sensor fault estimator are designed, respectively. In the fault estimation process, the states of the system are contained in the zonotopic sets estimated by the constrained zonotopic Kalman filter. The fault detection is carried out by judging whether the true value of the system's output is within the upper and lower bounds of its estimated zonotopic set. Once a fault is detected in the system, the corresponding sensor fault estimator can be used to estimate the additive or multiplicative sensor faults, and the corresponding zonotopic set and interval set can be obtained, respectively. Finally, comparative analyses of the proposed constrained zonotopic Kalman filter‐based fault estimators and the zonotopic Kalman filter‐based fault estimators in both numerical and case simulations prove the feasibility and effectiveness of the proposed algorithm and show the advantages of this algorithm in view of conservativeness.
High‐resolution temperature modeling of stream reconstruction alternatives
Authors: Hall Austin , Selker John S.
Published: June 2021

Streams are complex where biology, hydrology, and atmospheric processes are all important. Because quantifying and modeling of these systems can be challenging, many teams go directly to prescribed restoration treatments and principles. Restoration on the Middle Fork of the John Day River in Oregon, USA, shows how a project that was designed according to widely accepted restoration principles may lead to outcomes contrary to one of the project's stated goals: reducing peak temperatures for endangered salmonids on the site. This study employed the most sophisticated equipment available for stream temperature monitoring, including approximately 1 million independent hourly measurements in the 2‐week period considered. These data were collected along the river channel with fiber optic–distributed temperature sensing and were used to quantify thermal dynamics. These observations were paired with a physically based stream temperature model which was then employed to predict temperature change from design alternatives. Restored‐reach impact on peak temperature was directly correlated with the air–water interfacial area and the percentage of effective shade (R2 > 0.99). The increase in air–water area of the proposed design was predicted to increase daytime stream temperature by as much as 0.5°C upon completion of the work. Shade from riparian vegetation was found to potentially mitigate stream temperature increases, though only after decades of growth. A moderately dense canopy of 5 m tall trees blocking 17% of daily shortwave solar radiation is predicted to mitigate predicted temperature increases over the 1,800 m reach but also increases nighttime temperatures due to blocking of long‐wave radiation. These outcomes may not be intuitive to restoration practitioners and show how quantitative analysis can benefit the design of a project. This is significant in an area where riparian vegetation has been difficult to reestablish. Without quantitative analysis, restoration efforts can lead to outcomes opposite to stated goals and may be costly and disruptive interventions to fragile stream systems.
The eco‐friendly side of narcissism: The case of green marketing
Authors: Lin Han , Chen Lu , Yuan Ming , Yu Mingchuan , Mao Ye , Tao Fuwen
Published: June 2021

The march toward marrying good business practice with sustainability in the global marketing contexts is articulated with the hope of decoupling consumption and affluence from environmental deterioration. However, the key question, whether and how chief executive officers' (CEO) psychological characteristics exert its influence on corporate marketing activities with relation to environmental conservation, is still unsolved. The current study aimed at examining how the personality traits of CEOs affect corporate green marketing program (GMP), with primary regard to CEO narcissism. On the basis of a moderated mediation analysis on a batch of survey data from a sample of manufacturing firms in China, the findings showed that narcissistic CEOs are often associated with the higher level of the corporate green marketing program. Besides, corporate environmental strategy (ES) plays a role of mediator in the relationship between CEO narcissism and the implementation of green marketing. Furthermore, regulatory pressure not only significantly drives corporate environmental strategy and green marketing program but also moderates the relationships among CEO narcissism, corporate environmental strategy, and green marketing program. This study shines light on the establishment of management mode, which could illuminate both business practitioners and policymakers on the governance of sustainability.