bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogenolysis of biomass‐derived levulinic acid to produce 1,4‐pentanediol over Co/ZrO2 catalyst
Authors: Zhang Dingshuo , Zhang Heqian , Li Yue , Sun Daolai , Lv Jianhua
Published: February 2024

BACKGROUND

Levulinic acid is an important platform chemical derivable from lignocellulosic biomass. In this work, the hydrogenolysis of levulinic acid to produce 1,4‐pentanediol was performed over some Co‐based non‐noble catalysts. The relationship between the catalyst properties and the catalytic activity was investigated, and the effects of the reaction conditions on the catalytic activity were studied.

RESULTS

The Co/ZrO2 catalyst prepared by a coprecipitation method showed a high catalytic performance in the hydrogenolysis of levulinic acid to form 1,4‐pentanediol. The calcination of Co/ZrO2 significantly affected the catalytic activity, and a high calcination temperature of 750 °C could promote the formation of 1,4‐pentanediol. Meanwhile, the reduction of Co/ZrO2 at 400 °C in an H2 flow was beneficial for producing 1,4‐pentanediol, and the Co species after the reduction existed as the forms of Co2+ and Co0. A high H2 pressure and a moderate reaction temperature of 200 °C were beneficial for producing 1,4‐pentanediol, and a high 1,4‐pentanediol selectivity of 85.6% with a complete conversion of levulinic acid was obtained over the Co/ZrO2 catalyst at 200 °C under an H2 pressure of 7 MPa.

CONCLUSION

The Co species in the 400 °C‐reduced Co/ZrO2 catalyst existed as the forms of Co2+ and Co0. It was proposed that the synergistic effect of Co2+ and Co0 contributed to the effective formation of 1,4‐pentanediol from levulinic acid. © 2024 Society of Chemical Industry (SCI).
Metallurgical characteristics of AA6061 aluminium and AZ31B magnesium dissimilar joints by fusion welding technique
Authors: Ramaswamy Addanki , Nagasai Bellamkonda Prasanna , Dwivedy Maheshwar , Malarvizhi Sudersanan , Balasubramanian Visvalingam
Published: February 2024

Aluminium (Al) and magnesium (Mg) alloys are extensively used in the automobile sector because of their high strength‐to‐weight ratio, excellent castability low density and simplicity of recycling. Al‐Mg structures used in the automotive sector can potentially reduce their weight. Although there is a significant opportunity for substantial cost reduction, the use of magnesium in aluminium structures remains restricted. This study aims to weld 3 mm‐thick rolled sheets of AA6061 Al and AZ31B Mg alloy using the cold metal transfer (CMT) arc welding process. Three different filler wires (ER1100, ER4043, and ER5356) were used in the experiment. In this article, the mechanical and microstructure characteristics of Al/Mg dissimilar joints manufactured by CMT are evaluated and discussed in detail. Optical microscope (OM), scanning electron microscopy (SEM), energy dispersive x‐ray spectroscopy (EDX), and x‐ray diffraction (XRD) were used to analyze the CMT‐welded Al/Mg dissimilar joints. Of the three filler wires used, ER4043 (Al‐5%Si) filler wire yielded defect‐free sound joints due to the presence of Si, which improves the flow ability of molten filler during welding. The presence of Mg‐rich intermetallics‐Al12Mg17) and Al‐rich intermetallics‐Al3Mg2 were observed. The fractured area of the CMT‐welded Al/Mg dissimilar joints revealed the presence of the Mg‐rich intermetallics (Al12Mg17), which is responsible for the decrease in tensile strength. The reduction of intermetallics, particularly of Mg‐rich intermetallics (Al12Mg17) is important for improving joint strength.

Research Highlights

Cold metal transfer (CMT) arc welding was used to control the Al‐Mg‐rich intermetallics in the Al/Mg dissimilar joints.

The microstructure, morphology and phase composition of the welded joints were studied by OM, SEM, TEM, EDS and XRD.

The weld metal and AL substrate bonded with a strong interface, while weld metal and Mg substrate were joined at the epitaxial solidification area where the intermetallic compounds of Mg2Al3, Mg17Al12 and Mg2Si are generated.

The weld metal on the Mg side experienced brittle fracture, with a continuous distribution of Mg2Al3, Mg17Al12 and Mg2Si.
Efficacy and safety of pantoprazole and itopride in patients with overlap of gastroesophageal reflux disease and dyspepsia: A prospective, open‐label, single‐arm pilot study
Authors: Lakhtakia Sundeep , Singh Aniruddha P , Singla Neeraj , Memon Sana F , Reddy Duvvur N
Published: February 2024

Background and Aim

Combining proton pump inhibitors (PPIs) with prokinetics can provide synergistic action in patients with gastroesophageal reflux disease (GERD) and overlapping dyspepsia, but data regarding this is lacking.

Methods

This single‐center, prospective study evaluated the efficacy and safety of 6‐week treatment with fixed‐drug combination (FDC) of pantoprazole (PPI) and itopride (prokinetic) in 50 patients with ≥3 month history of GERD and overlapping dyspepsia refractory to pantoprazole. Efficacy was assessed as reduction in GERD symptom assessment scale (GSAS) distress score for 15 symptoms from baseline to week 6. Adverse events (AEs) were monitored up to week 6.

Results

Although heartburn was the most common symptom at week 6 (26.8%), its frequency significantly decreased from baseline (84.0%; P <0.01). A similar trend was observed for other symptoms: pressure/discomfort inside chest (19.5%), belching (14.6%), regurgitation (12.2%), bloating (9.8%), flatulence (9.8%), early satiety (7.3%), acidic/sour taste in mouth (7.3%), nausea (7.3%), frequent gurgling in stomach/belly (4.9%), and pressure/lump in throat (2.4%). Mean distress scores of all symptoms markedly decreased at week 6. Three AEs (n = 2) of moderate intensity were reported.

Conclusion

The FDC of pantoprazole and itopride showed favorable efficacy and safety in patients with GERD and overlapping dyspepsia refractory to pantoprazole monotherapy. Nevertheless, further studies are warranted.
A novel composition of endogenous metabolic modulators improves red blood cell properties in sickle cell disease
Authors: van Dijk Myrthe J. , Traets Marissa J. M. , van Oirschot Brigitte A. , Ruiter Titine J. J. , de Wilde Jonathan R. A. , Bos Jennifer , van Solinge Wouter W. , Koziel Margaret J. , Jans Judith J. M. , Wani Revati , van Beers Eduard J. , van Wijk Richard , Rab Minke A. E.
Published: February 2024

The most common forms of sickle cell disease (SCD) are sickle cell anemia (SCA; HbSS) and HbSC disease. In both, especially the more dense, dehydrated and adherent red blood cells (RBCs) with reduced deformability are prone to hemolysis and sickling, and thereby vaso‐occlusion. Based on plasma amino acid profiling in SCD, a composition of 10 amino acids and derivatives (RCitNacQCarLKHVS; Axcella Therapeutics, USA), referred to as endogenous metabolic modulators (EMMs), was designed to target RBC metabolism. The effects of ex vivo treatment with the EMM composition on different RBC properties were studied in SCD (n = 9 SCA, n = 5 HbSC disease). Dose‐dependent improvements were observed in RBC hydration assessed by hemocytometry (MCV, MCHC, dense RBCs) and osmotic gradient ektacytometry (Ohyper). Median (interquartile range [IQR]) increase in Ohyper compared to vehicle was 4.9% (4.0%–5.5%), 7.5% (6.9%–9.4%), and 12.8% (11.5%–14.0%) with increasing 20×, 40×, and 80X concentrations, respectively (all p < 0.0001). RBC deformability (EImax using oxygen gradient ektacytometry) increased by 8.1% (2.2%–12.1%; p = 0.0012), 9.6% (2.9%–15.1%; p = 0.0013), and 13.3% (5.7%–25.5%; p = 0.0007), respectively. Besides, RBC adhesion to subendothelial laminin decreased by 43% (6%–68%; p = 0.4324), 58% (48%–72%; p = 0.0185), and 71% (49%–82%; p = 0.0016), respectively. Together, these results provide a rationale for further studies with the EMM composition targeting multiple RBC properties in SCD.
MR Susceptibility Separation for Quantifying Lesion Paramagnetic and Diamagnetic Evolution in Relapsing–Remitting Multiple Sclerosis
Authors: Zhu Ziyan , Naji Nashwan , Esfahani Javad Hamidi , Snyder Jeff , Seres Peter , Emery Derek J. , Noga Michelle , Blevins Gregg , Smyth Penelope , Wilman Alan H.
Published: February 2024

Background

Multiple sclerosis (MS) lesion evolution may involve changes in diamagnetic myelin and paramagnetic iron. Conventional quantitative susceptibility mapping (QSM) can provide net susceptibility distribution, but not the discrete paramagnetic and diamagnetic components.

Purpose

To apply susceptibility separation (χ separation) to follow lesion evolution in MS with comparison to R2*/R2′/QSM.

Study Type

Longitudinal, prospective.

Subjects

Twenty relapsing–remitting MS subjects (mean age: 42.5 ± 9.4 years, 13 females; mean years of symptoms: 4.3 ± 1.4 years).

Field Strength/Sequence

Three‐dimensional multiple echo gradient echo (QSM and R2* mapping), two‐dimensional dual echo fast spin echo (R2 mapping), T2‐weighted fluid attenuated inversion recovery, and T1‐weighted magnetization prepared gradient echo sequences at 3 T.

Assessment

Data were analyzed from two scans separated by a mean interval of 14.4 ± 2.0 months. White matter lesions on fluid‐attenuated inversion recovery were defined by an automatic pipeline, then manually refined (by ZZ/AHW, 3/25 years' experience in MRI), and verified by a radiologist (MN, 25 years' experience in MS). Susceptibility separation yielded the paramagnetic and diamagnetic susceptibility content of each voxel. Lesions were classified into four groups based on the variation of QSM/R2* or separated into positive/negative components from χ separation.

Statistical Tests

Two‐sample paired t tests for assessment of longitudinal differences. Spearman correlation coefficients to assess associations between χ separation and R2*/R2′/QSM. Significant level: P < 0.005.

Results

A total of 183 lesions were quantified. Categorizing lesions into groups based on χ separation demonstrated significant annual changes in QSM//R2*/R2′. When lesions were grouped based on changes in QSM and R2*, both changing in unison yielded a significant dominant paramagnetic variation and both opposing yielded a dominant diamagnetic variation. Significant Spearman correlation coefficients were found between susceptibility‐sensitive MRI indices and χ separation.

Data Conclusion

Susceptibility separation changes in MS lesions may distinguish and quantify paramagnetic and diamagnetic evolution, potentially providing additional insight compared to R2* and QSM alone.

Level of Evidence

2

Technical Efficacy

Stage 2
Study on the virulence of Metarhizium anisopliae against Spodoptera frugiperda (J. E. Smith, 1797)
Authors: Perumal Vivekanandhan , Kannan Swathy , Alford Lucy , Pittarate Sarayut , Krutmuang Patcharin
Published: February 2024

This study examined the impact of Metarhizium anisopliae (Hypocreales: Clavicipitaceae) conidia on the eggs, larvae, pupae, and adults of Spodoptera frugiperda. The results showed that eggs, larvae, pupae, and adults exhibited mortality rates that were dependent on the dose. An increased amount of conidia (1.5 × 109 conidia/mL) was found to be toxic to larvae, pupae, and adults after 9 days of treatment, resulting in a 100% mortality rate in eggs, 98% in larvae, 76% in pupae, and 85% in adults. A study using earthworms as bioindicators found that after 3 days of exposure, M. anisopliae conidia did not cause any harmful effects on the earthworms. In contrast, the chemical treatment (positive control) resulted in 100% mortality at a concentration of 40 ppm. Histopathological studies showed that earthworm gut tissues treated with fungal conidia did not show significant differences compared with those of the negative control. The gut tissues of earthworms treated with monocrotophos exhibited significant damage, and notable differences were observed in the chemical treatment. The treatments with 70 and 100 µg/mL solutions of Eudrilus eugeniae epidermal mucus showed no fungal growth. An analysis of the enzymes at a biochemical level revealed a decrease in the levels of acetylcholinesterase, α‐carboxylesterase, and β‐carboxylesterase in S. frugiperda larvae after exposure to fungal conidia. This study found that M. anisopliae is effective against S. frugiperda, highlighting the potential of this entomopathogenic fungus in controlling this agricultural insect pest.
Multiyear variability of cloud genera in Krakow in the context of changes in the thermal state of the North Atlantic
Authors: Marsz Andrzej A. , Matuszko Dorota , Styszyńska Anna
Published: February 2024

The analysis conducted in this study examines the relationships between changes in cloud cover and the occurrence of cloud genera in Krakow, Poland, and the variations in the thermal state of the North Atlantic (NA) from 1951 to 2020. The existence of areas where annual sea surface temperature (SST) changes exhibit statistically significant correlations with the annual frequency of specific cloud genera was observed. These relationships vary in space: An increase in SST over the NA, particularly in the western and central regions of the subtropical NA, leads to a decrease in the frequency of stratiform clouds at all levels (Cs, As, Ns and St) and an increase in the frequency of convective clouds (Cu, Sc). An attempt to explain this phenomenon demonstrates that there is a correlation between the frequency of specific cloud genera and the variability of meridional SST gradients, as well as changes in the intensity of the thermohaline circulation in the NA (NA THC), which control the variability of mid‐tropospheric circulation (500 hPa). During positive phases of NA THC (the “warm” state of the NA), zonal circulation prevails over Europe, leading to an increase in the height of h500, an increase in the frequency of anticyclonic weather and a decrease in the frequency of cyclonic weather, including a significant proportion of frontal weather systems. Consequently, there is a reduction in frequency of stratiform clouds and an increase in the occurrence of vertically developed convective clouds, thereby increasing the possibility of observing middle‐level (Ac) and high‐level (Ci, Cc) clouds. In negative phases of NA THC (the “cool” state of the NA), the situation is reversed, with meridional circulation dominating over Europe, h500 lowering, an increase in the frequency of cyclonic systems with fronts, and an increase in the frequency of stratiform clouds. This results in decreased sunshine duration and a reduction in the amount of solar energy reaching the Earth's surface.
Effect of ozone sterilization on controlling leaf mildew and gray mold tomato disease in a glasshouse and its influence on other growth parameters
Authors: Li Xinao , Liu Yuanyi , Zhang Ce , Che Hailong , He Qinghao , Wang Lijuan , Yao Bing
Published: February 2024

BACKGROUND

In order to explore the effect of ozone sterilization treatment on tomato disease control and increase fruit setting rate, this study took 906 pink fruit tomato as test material, used a small ozone generator to carry out ozone treatment single‐factor test, and then selected orthogonal table to guide the ozone treatment combination. The effects of different ozone treatment concentration, ozone treatment duration and ozone treatment times on the growth, disease and fruit setting rate of potted tomato were analyzed.

RESULTS

Different ozone treatment had effects on leaf mildew, gray mold and fruit setting rate of tomato. The influence degree of three factors on leaf mildew, gray mold and fruit setting rate was from large to small, a > b > c, a > c > b, b > a > c. A quadratic regression model was established with the control effect of tomato leaf mildew, gray mold and fruit setting rate as response values, and the optimal parameter combination was determined: The ozone treatment concentration was 0.0465 g kg−1, the ozone treatment time was 30 min, and the ozone treatment times were twice a week. In this case, the control efficiency of tomato leaf mildew was 95.02%, the control effect of gray mold was 99.49%, and the fruit setting rate was 76.5%. The test parameters were accurate and reliable.

CONCLUSION

The ozone sterilization method proposed in this article is safe and green, and can provide theoretical support for the recovery and reconstruction of tomato disease in a glasshouse. © 2024 Society of Chemical Industry.
Anthocyanins and nucleation seeds are key factors affecting quercetin precipitation in red wines
Authors: Luciano Alessandra , Picariello Luigi , Forino Martino , Moio Luigi , Gambuti Angelita
Published: February 2024

Background

Climate changes have been leading to an excessive synthesis of quercetin (Q) and its glycosides (Q‐Gs) in specific red grape varieties, such as Sangiovese. This has resulted in concentrations overcoming the solubility threshold of Q in wines, with the consequent formation of undesirable precipitates. This study aims at assessing the impact of various factors, including anthocyanins, temperature, nucleation seeds and time, on the precipitation of Q in red wine.

Results

The influence of anthocyanins on Q solubility was examined by adding a grape skin extract rich in anthocyanins to a model solution containing 89 μmol L−1 of Q. The data revealed that the solubility of both Q and Q‐Gs increased as a function of the anthocyanin concentration in the model solution. In a subsequent experiment, red wines were stored at two different temperatures (2 and 20 °C), supplemented with Q nucleation seeds, and monitored over a 10‐day period. Notably, after only 3 days of contact with Q seeds at 2 °C, a reduction of over 75% in Q concentration was observed in the supernatant. Among the considered factors, contact with nucleation seeds emerged as the most significant one (P < 0.0001).

Conclusion

Q precipitation in red wines is influenced by the presence of anthocyanins in solution, although it is not the sole determinant. The data also suggested that a potential strategy for wineries to mitigate the risk of Q precipitation in bottled wine would be the acceleration of this process by promoting the formation of nucleation seeds. © 2024 Society of Chemical Industry.
Effect and mechanism of freezing on the quality and structure of soymilk gel induced by different salt ions
Authors: Xia Xiaoyu , Yang Xinxin , Zhu Ying , Sun Ying , Zhu Xiuqing
Published: February 2024

BACKGROUND

The increasing attention toward frozen soy‐based foods has sparked interest. Variations exist in the quality and structure of soymilk gels induced by different salt ions, leading to diverse changes post‐freezing. This study compared and analyzed the effects of calcium chloride (CC), magnesium chloride (MC) and calcium sulfate (CS) on the quality characteristics and protein structure changes of soymilk gels (CC‐S, MC‐S and CS‐S) before and after freezing, and clarified the mechanisms of freezing on soymilk gel.

RESULTS

The formation rate of soymilk gel is influenced by the type of salt ions. In comparison to CS and MC, soymilk gel induced by CC exhibited the fastest formation rate, highest gel hardness, lowest moisture content, and smaller gel pores. However, freezing treatment deteriorated the quality of soymilk gel induced by different salt ions, leading to a decline in textural properties (hardness and chewiness). Among these, the textual state of CC‐induced soymilk gel remained optimal, exhibiting the least apparent damage and minimal cooking loss. Freezing treatments prompt a transition of soymilk gel secondary structure from β‐turns to β‐sheets, disrupting the protein's tertiary structure. Furthermore, freezing treatments also fostered the crosslinking between soymilk gel protein, increasing the content of disulfide bonds.

CONCLUSION

The quality of frozen soymilk gel is influenced by the rate of gel formation induced by salt ions. After freezing, soymilk gel with faster gelation rates exhibited a greater tendency for the transformation of protein–water interactions into protein–protein interactions. They showed a higher degree of disulfide bond formation, resulting in a more tightly knit and firm frozen gel network structure with denser and more uniformly distributed pores. © 2024 Society of Chemical Industry.
In vitro fermentation characteristics of different types of fiber‐rich ingredients by pig fecal inoculum
Authors: Luo Chengzeng , Duan Jiujun , Zhong Ruqing , Liu Lei , Gao Qingtao , Liu Xuelan , Chen Liang , Zhang Hongfu
Published: February 2024

BACKGROUND

Dietary fibers with varying physicochemical properties have different fermentation characteristics, which may differently impact host health. The present study aimed to determine the fermentation characteristics including gas production kinetics, short‐chain fatty acids (SCFAs) production and microbial composition of different fibrous ingredients using in vitro fermentation by fecal microbiota.

RESULTS

Sugar beet pule (SBP), wheat bran (WB), dried corn distillers grains with solubles (DDGS), rice bran (RB) and alfalfa meal (AM) were selected to fermentation in vitro for 36 h. The results showed that SBP had the greatest gas production. SBP had the highest in vitro dry matter fermentability (IVDMF) and production of acetate, propionate and total SCFAs, followed by WB, which were all greater than DDGS, AM and RB. The alpha‐diversity was higher in the DDGS, AM and RB groups than in the WB and SBP groups. Differences in microbial community composition were observed among groups. The relative abundance of Treponema was highest in WB group. RB group showed lower Prevotella abundance than other groups but had higher Succinivibrio abundance. Interestingly, the Lactobacillus reached the highest abundances in the DDGS group. Correlation analysis indicated that the relative abundance of Treponema and Prevotella was positively associated with the gas production, IVDMF and SCFAs, whereas norank_f_Muribaculaceae, Rikenellaceae_RC9_gut_group, Lysinibacillus and Succinivibrio were the opposite.

CONCLUSION

Collectively, WB and SBP were fermented rapidly by fecal microbiota compared to DDGS, AM and RB. Different fiber sources have different fiber compositions and fermentation properties that affect the microbial compositins and SCFAs production. © 2024 Society of Chemical Industry.
Effect of Complex Decongestive Therapy on Quality of Life and Physical Parameters in Head and Neck Lymphedema
Authors: Keskin Kavak Songul , Duran Arzubetül , Ünsal Delialioğlu Sibel , Aktekin Lale
Published: February 2024

Objective

To assess the effect of complex decongestive therapy treatment (CDT) on quality of life, neck disability, cervical range of motion, and facial and neck lymphedema size using specific anatomical landmark points.

Methods

This prospective study was conducted in a tertiary cancer center in Turkey. Thirty patients included in the study were treated with CDT for 21 days. The patients were evaluated before and after CDT with MD Anderson Cancer Center Head and Neck Lymphedema (MDACC HNC) staging system, The Neck Disability Index, European Organization for Research and Treatment of Cancer Quality of Life 30 (EORTC‐QLOC30), Facial Composite score and Neck Circumferences, cervical range of motion.

Results

Median follow‐up was 7.2 months. After treatment of 30 patients significant cognitive function, emotional function, and social function (p < 0.001). After CDT treatment, the quality of life sub‐parameters of EORTC QLQ‐C30 showed significant improvement (p < 0.001). The facial composite score and neck circumferences indices showed significant improvement (p < 0.001). A decrease of 2% or more in the facial composite score and neck circumferences was observed in all patients participating in the study.

Conclusion

There have been few studies on the effectiveness of CDT on the EORTC QLQ‐C30, facial composite score, and neck circumferences in head and neck lymphedema. In patients with head and neck lymphedema following head and neck cancer, our study demonstrated the positive effects of complex decongestive therapy (CDT) on neck disability, range of motion, quality of life, and facial and neck lymphedema tissue size.

Level of Evidence

4 Laryngoscope, 134:3152–3157, 2024
Watershed, lake, and food web factors influence diazotrophic cyanobacteria in mountain lakes
Authors: Jansen Lara S. , Sobota Daniel , Pan Yangdong , Strecker Angela L.
Published: February 2024

Cyanobacterial blooms can occur in freshwater ecosystems largely isolated from development and not experiencing extensive cultural eutrophication. For example, remote mountain lakes can experience intense blooms of diazotrophic (nitrogen‐fixing) cyanobacteria caused by factors acting at different spatial and temporal scales. In this study, we examined how cross‐scale interactions among watershed, lake, and food web characteristics influence diazotrophic cyanobacteria biovolume in mountain lakes. We quantified diazotrophic cyanobacteria biovolume, zooplankton abundance, and physico‐chemical variables for 29 lakes in the Cascade Mountains of Oregon, USA, in summer 2019. Watershed characteristics were compiled from historical datasets available for the region. Diazotrophic cyanobacteria biovolume ranged across the lakes from 0 to 1,930,000 μm3 mL−1; Dolichospermum was the most common genus. Random forest models showed that 11 watershed, lake, and food web characteristics explained 76% of the variance in diazotrophic cyanobacteria biovolume among the sampled lakes. Structural equation models suggested that the drainage ratio (i.e., the relative area of the lake to the watershed) was positively related to phosphorus concentrations and, in turn, to diazotroph biovolume. Among lakes, hypolimnetic dissolved oxygen was negatively correlated with diazotroph biovolume, possibly due to the release of nutrients, like phosphate and iron, bound to sediments. In addition, zooplankton grazers were negatively related to diazotrophic cyanobacteria biovolume, potentially reflecting the influence of stocked fish. Thus, lake management must account for bottom‐up factors, such as nutrient loading, which is influenced by lake morphometry and watershed size, as well as top‐down factors, such as fish stocking, to effectively mitigate diazotrophic cyanobacterial blooms.
Light Engineering and Silicon Diffractive Optics Assisted Nonparaxial Terahertz Imaging
Authors: Orlov Sergej , Ivaškevičiūtė‐Povilauskienė Rusnė , Mundrys Karolis , Kizevičius Paulius , Nacius Ernestas , Jokubauskis Domas , Ikamas Kęstutis , Lisauskas Alvydas , Minkevičius Linas , Valušis Gintaras
Published: February 2024

The art of light engineering unveils a world of possibilities through the meticulous manipulation of photonic properties such as intensity, phase, and polarization. Precision control over these properties finds application in a variety of fields spanning communications, light–matter interactions, laser direct writing, and imaging. Terahertz (THz) range, nestled between microwaves and infrared light, stands out for its remarkable ability to propagate with minimal losses in numerous dielectric materials and compounds, making THz imaging a powerful tool for noninvasive control and inspection. In this study, a rational framework for the design and optimal assembly of nonparaxial THz imaging systems is established. The research is centered on lensless photonic systems composed solely of high‐resistivity silicon‐based nonparaxial elements such as the Fresnel zone plate, the Fibonacci lens, the Bessel axicon, and the Airy zone plate, all fabricated using laser ablation technology. Through a comprehensive examination through illumination engineering and scattered light collection from raster‐scanned samples in a single‐pixel detector scheme, the imaging systems are evaluated via diverse metrics including contrast, resolution, depth of field, and focus. These findings chart an exciting course toward the development of compact and user‐friendly THz imaging systems where sensors and optical elements seamlessly integrate into a single chip.
Informal employment and corruption: Differences across gender and industry
Authors: Berdiev Aziz N. , Goel Rajeev K. , Saunoris James W.
Published: February 2024

This paper adds to the literature studying the substitution and complementarity between corruption and the shadow economy by focusing on the differential effects of various informal employment categories, by gender (informal employment by men vs. women) and across industries (informal employment in the agriculture vs. non‐agriculture sectors). Using cross‐national data, we find evidence of complementarity between corruption and informal employment, after accounting for possible simultaneity. This complementarity holds across different informal employment categories, with some quantitative differences. These findings have policy relevance for the coordination of anti‐corruption and anti‐underground‐economy policies, and whether such policies should be sector specific.
MV‐based relative electron density estimation (iMREDe) for MR‐LINAC dose calculation
Authors: Myronakis Marios , Hu Yue‐Houng , Jacobson Matthew William , Williams Christopher Leigh , Berbeco Ross Isaac
Published: February 2024

Background

MR‐LINAC systems have been increasingly utilized for real‐time imaging in adaptive treatments worldwide. Challenges in MR representation of air cavities and subsequent estimation of electron density maps impede planning efficiency and may lead to dose calculation uncertainties.

Purpose

To demonstrate the generation of accurate electron density maps using the primary MV beam with a flat‐panel imager.

Methods

The ViewRay MRIdian MR‐LINAC system was modeled digitally for Monte Carlo simulations. Iron shimming, the magnetic field, and the proposed flat panel detector were included in the model. The effect of the magnetic field on the detector response was investigated. Acquisition of projections over 360 degrees was simulated for digital phantoms of the Catphan 505 phantom and a patient treated for Head and Neck cancer. Shim patterns on the projections were removed and detector noise linearity was assessed. Electron density maps were generated for the digital patient phantom using the flat‐panel detector and compared with actual treatment planning CT generated electron density maps of the same patient.

Results

The effect of the magnetic field on the detector point‐spread function (PSF) was found to be substantial for field strengths above 50 mT. Shims correction in the projection images using air normalization and in‐painting effectively removed reconstruction artifacts without affecting noise linearity. The relative difference between reconstructed electron density maps from the proposed method and electron density maps generated from the treatment planning CT was 11% on average along all slices included in the iMREDe reconstruction.

Conclusions

The proposed iMREDe technique demonstrated the feasibility of generating accurate electron densities for the ViewRay MRIdian MR‐LINAC system with a flat‐panel imager and the primary MV beam. This work is a step towards reducing the time and effort required for adaptive radiotherapy in the current ViewRay MR‐LINAC systems.
Development of patient and catheter specific error thresholds for high dose rate prostate brachytherapy
Authors: Koprivec Dylan , Belanger Cedric , Beaulieu Luc , Chatigny Philippe Y. , Rosenfeld Anatoly , Cutajar Dean , Petasecca Marco , Howie Andrew , Bucci Joseph , Poder Joel
Published: February 2024

Background

In‐vivo source tracking has been an active topic of research in the field of high‐dose rate brachytherapy in recent years to verify accuracy in treatment delivery. Although detection systems for source tracking are being developed, the allowable threshold of treatment error is still unknown and is likely patient‐specific due to anatomy and planning variation.

Purpose

The purpose of this study was to determine patient and catheter‐specific shift error thresholds for in‐vivo source tracking during high‐dose‐rate prostate brachytherapy (HDRPBT).

Methods

A module was developed in the previously described graphical processor unit multi‐criteria optimization (gMCO) algorithm. The module generates systematic catheter shift errors retrospectively into HDRPBT treatment plans, performed on 50 patients. The catheter shift model iterates through the number of catheters shifted in the plan (from 1 to all catheters), the direction of shift (superior, inferior, medial, lateral, cranial, and caudal), and the magnitude of catheter shift (1–6 mm). For each combination of these parameters, 200 error plans were generated, randomly selecting the catheters in the plan to shift. After shifts were applied, dose volume histogram (DVH) parameters were re‐calculated. Catheter shift thresholds were then derived based on plans where DVH parameters were clinically unacceptable (prostate V100 < 95%, urethra D0.1cc > 118%, and rectum Dmax > 80%). Catheter thresholds were also Pearson correlated to catheter robustness values.

Results

Patient‐specific thresholds varied between 1 to 6 mm for all organs, in all shift directions. Overall, patient‐specific thresholds typically decrease with an increasing number of catheters shifted. Anterior and inferior directions were less sensitive than other directions. Pearson's correlation test showed a strong correlation between catheter robustness and catheter thresholds for the rectum and urethra, with correlation values of –0.81 and –0.74, respectively (p < 0.01), but no correlation was found for the prostate.

Conclusions

It was possible to determine thresholds for each patient, with thresholds showing dependence on shift direction, and number of catheters shifted. Not every catheter combination is explorable, however, this study shows the feasibility to determine patient‐specific thresholds for clinical application. The correlation of patient‐specific thresholds with the equivalent robustness value indicated the need for robustness consideration during plan optimization and treatment planning.
Self‐supervised multicontrast super‐resolution for diffusion‐weighted prostate MRI
Authors: Gundogdu Batuhan , Medved Milica , Chatterjee Aritrick , Engelmann Roger , Rosado Avery , Lee Grace , Oren Nisa C. , Oto Aytekin , Karczmar Gregory S.
Published: February 2024

Purpose

This study addresses the challenge of low resolution and signal‐to‐noise ratio (SNR) in diffusion‐weighted images (DWI), which are pivotal for cancer detection. Traditional methods increase SNR at high b‐values through multiple acquisitions, but this results in diminished image resolution due to motion‐induced variations. Our research aims to enhance spatial resolution by exploiting the global structure within multicontrast DWI scans and millimetric motion between acquisitions.

Methods

We introduce a novel approach employing a “Perturbation Network” to learn subvoxel‐size motions between scans, trained jointly with an implicit neural representation (INR) network. INR encodes the DWI as a continuous volumetric function, treating voxel intensities of low‐resolution acquisitions as discrete samples. By evaluating this function with a finer grid, our model predicts higher‐resolution signal intensities for intermediate voxel locations. The Perturbation Network's motion‐correction efficacy was validated through experiments on biological phantoms and in vivo prostate scans.

Results

Quantitative analyses revealed significantly higher structural similarity measures of super‐resolution images to ground truth high‐resolution images compared to high‐order interpolation (p 0.005). In blind qualitative experiments, of super‐resolution images were assessed to have superior diagnostic quality compared to interpolated images.

Conclusion

High‐resolution details in DWI can be obtained without the need for high‐resolution training data. One notable advantage of the proposed method is that it does not require a super‐resolution training set. This is important in clinical practice because the proposed method can easily be adapted to images with different scanner settings or body parts, whereas the supervised methods do not offer such an option.
Women in the pulpit: Characteristics of protestant churches led by a female pastor
Authors: Lee Young‐joo
Published: February 2024

This study examines how congregational characteristics of a Protestant church relate to having a female pastor, using the glass ceiling and glass cliff theories. The analysis of the 2018–2019 National Congregational Study and the National Survey of Religious Leaders linked data shows that churches with a greater number of participants are less likely to have a female pastor, implying that the glass ceiling is more pervasive in larger congregations. The results also reveal that churches with stagnant or declining revenues are more likely to have a female pastor, which is consistent with the glass cliff theory. Churches with a greater level of racial diversity and those located in urban areas are more likely to have a female pastor, suggesting a link between sociodemographic diversity within a congregation and women's congregational leadership. These findings can be applied to understanding the gender gap in nonprofit leadership in general.
Aiding philanthropic venture capitalists investing in social enterprises: A multi‐criteria decision‐making approach
Authors: Salimi Negin , ten Have Gijs Robbert
Published: February 2024

Social enterprises have emerged as promising solutions for addressing environmental and societal challenges. To enhance their access to financial capital and align their business proposals with the preferences of impact investors, it is crucial to understand how Philanthropic venture capitalists (PhVCs) evaluate potential portfolio companies. This study introduces a framework to assist PhVCs in making more informed investment decisions, fostering successful, long‐term partnerships between investors and investees. The proposed approach begins by determining the significance of investment criteria using the Best‐Worst Method (BWM). Subsequently, the performance of portfolio companies is evaluated, ultimately identifying the most favorable investment opportunities. We apply this framework to a Dutch philanthropic venture capitalist, and our analysis reveals that ‘Potential’ and the ‘Management team’ rank highest in terms of investment criteria importance, while ‘Assessment of the deal’ and ‘External environment’ carry lower significance. Furthermore, our approach, incorporating the BWM outcomes, considers investors' personal preferences and offers a method for ranking portfolio companies based on their value and performance.
A photographic atlas for European freshwater and migratory fish remains and key considerations for their analysis
Authors: Davis Izzy , Sykes Naomi , Hochmuth Michael , Outram Alan , Roffet‐Salque Mélanie
Published: February 2024

Identification of archeological fish remains requires the use of comparative reference materials, generally in the form of disarticulated fish skeletons. Photographic or illustrative atlases provide an additional resource for the analysis of fish remains. Photographic resources exist for many marine species and for specific geographic regions, whereas freshwater European species have not been covered in great detail. Here, we present a photographic atlas for the bones of freshwater and migratory fish commonly recovered from archeological sites in Central Europe, alongside a discussion of the difficulties and considerations for the analysis of freshwater fish remains. The atlas also highlights the morphological similarity of many species and the interpretive limits of freshwater fish assemblages. The atlas aims to act as an accessible and user‐friendly resource, which can be used for basic identification purposes when access to physical collections is not possible, to supplement pre‐existing collections, or for training purposes. This paper acts as a platform from which the full atlas can be downloaded.
Synthesis of Silicon and Germanium Oxide Nanostructures via Photonic Curing; a Facile Approach to Scale Up Fabrication
Authors: Khatoon Najma , Subedi Binod , Chrisey Douglas B.
Published: February 2024

Silicon and Germanium oxide (SiOx and GeOx) nanostructures are promising materials for energy storage applications due to their potentially high energy density, large lithiation capacity (~10X carbon), low toxicity, low cost, and high thermal stability. This work reports a unique approach to achieving controlled synthesis of SiOx and GeOx nanostructures via photonic curing. Unlike conventional methods like rapid thermal annealing, quenching during pulsed photonic curing occurs rapidly (sub‐millisecond), allowing the trapping of metastable states to form unique phases and nanostructures. We explored the possible underlying mechanism of photonic curing by incorporating laws of photophysics, photochemistry, and simulated temperature profile of thin film. The results show that photonic curing of spray coated 0.1 M molarity Si and Ge Acetyl Acetate precursor solution, at total fluence 80 J cm−2 can yield GeOx and SiOx nanostructures. The as‐synthesized nanostructures are ester functionalized due to photoinitiated chemical reactions in thin film during photonic curing. Results also showed that nanoparticle size changes from ~48 nm to ~11 nm if overall fluence is increased by increasing the number of pulses. These results are an important contribution towards large‐scale synthesis of the Ge and Si oxide nanostructured materials which is necessary for next‐generation energy storage devices.
Synergistic effect of the glass bead and continuous glass fibers on the low‐velocity impact resistance of nylon 6 matrix composites
Authors: Yang Shun , Wei Ying , Yin Hongfeng , Tang Yun , Ren Xiaohu , Yuan Hudie , Li Dawei , Zhang Xinting
Published: February 2024

Glass fiber‐reinforced resin matrix composites have good mechanical and impact resistance properties, while with particle co‐reinforcement, a synergistic effect can further improve their performance. In this paper, continuous glass fiber‐reinforced nylon 6 (GF/PA6) and continuous glass fiber (GF) with glass beads (GBs) co‐reinforced nylon 6 (GB–GF/PA6) were prepared to investigate the co‐reinforcement mechanism and the synergistic effect of particle and fiber. A quantitative parameter of the residual impact force divided by the critical force Pr/Pcr, as the damage degree of the low‐velocity impact, is defined to evaluate the impact resistance of the composite. The results indicate that the damage of GB–GF/PA6 was lower than that of GF/PA6, and the synergistic effect reaches the most obvious at the GB addition of 10 wt%. Scanning electron microscope (SEM) and x‐ray computed tomography (XCT) images disclose that GB impedes the type II crack spread in the matrix and fiber/matrix interface. With the type II cracks reducing, the materials' resistance to delamination can be significantly enhanced. For the composite structure, in which 10 wt% GB and 60 wt% GF are introduced, the flexural strength, shear strength, and pendulum impact strength were tested with the maximum values of 379.4 MPa, 53.1 MPa, and 219.0 J/m2, respectively. This composite structure design, presenting a continuous GF and GBs co‐reinforce effect, offers a manufacturing process that is easily scalable to achieve excellent characteristics.
Synergistic toughening modification and finite element analysis of carbon fiber/epoxy resin‐reinforced composites
Authors: Xu Weihao , Wang Yuqing , Gu Zhiqi , Wang Ping , Zhang Yan , Li Yuanyuan
Published: February 2024

In this work, the poor fracture toughness of carbon fiber‐reinforced composites (CFRPs) was improved by the introduction of a graphene oxide/nanosilica (GOS) hybrid, and short carbon fibers (SCFs) were investigated through experimental and modeling methods. The effects of the SCF content, number of SCF layers, and introduction position on the mode I fracture toughness (GIC) and mode II fracture toughness (GIIC) of the composites were considered for epoxy resin (EP) modified by GOS. The results showed that GOS and SCF exhibited a synergistic toughening effect on CFRP. The GIC and GIIC of CFRP laminate with GOS content of 0.2 wt% and SCF content of 0.4 wt% reached 0.506 and 2.15 kJ/m2, increased by 72.2% and 53.6% compared to the unmodified composite, respectively. The number of layers and the lamination mode of GC10S5‐B specimens exhibited the optimal improvement of interlaminar fracture toughness. Similarly compared with those of the original. The GIC and GIIC of the CFRP laminates reached 0.662 and 0.506 kJ/m2 (enhanced by 125.9% and 95%, respectively). In addition, the stress propagation path and distribution, and progressive damage of the CFRP composites were obtained to further reveal the toughness mechanism.

Highlights

Synergistic toughening of resin modification and short carbon fiber on modes I and II fracture toughness of composites were considered.

Content of short carbon fiber and lay‐up methods on toughness performance were investigated thoroughly.

Finite element models were established to reveal the stress progress and distribution and toughness mechanism.
Mechanical recycling and electro‐thermal welding of epoxy vitrimer nanocomposites
Authors: Lorero I. , Mujica A. , Campo M. , Prolongo S. G.
Published: February 2024

Vitrimers constitute a new class of recyclable thermosets based on the incorporation of associative dynamic covalent bonds, such as disulfide bonds, into the crosslinked matrix. These reversible bonds usually require excess dynamic bonds to confer proper self‐healing and recycling capabilities to the thermoset. In that way, we manufacture epoxy resins cured with 4‐aminophenyl disulfide (AFD) in a stoichiometric ratio, and with 10 and 20 wt% of AFD excesses to analyze the effect of composition on resin properties. Beyond the neat vitrimers analysis, we manufacture nanocomposites doped with carbon nanotubes (CNT) to obtain electroactive vitrimers. These epoxy resins and nanocomposites can be mechanically recycled by milling and hot‐pressing. The recycled nanocomposites conserve partially CNT integrity and dispersion. Even more, recycled nanocomposites with AFD excesses maintain the mechanical strength of the pristine nanocomposites. Vitrimer nanocomposite samples can be also electrically welded, due to their heating by the Joule effect, through a relatively low voltage application, and therefore with low energy consumption, to obtain a monolithic specimen. In summary, the manufactured epoxy vitrimers and nanocomposites are recyclable and sustainable epoxy materials, which can be processed and reprocessed using technologies easily implementable, fast, and with low energy consumption.

Highlights

Electroactive and re‐processable vitrimer nanocomposites are manufactured.

Nanocomposite vitrimers show conductivities similar to conventional epoxies.

Bond exchanging temperatures can be reached by Joule heating.

CNT addition enhances disulfide exchanges and thermo‐mechanical recyclability.

Electrothermal welding of vitrimer nanocomposites is successfully tested.