bluuebunny/crossref_metadata_2025 huggingface dataset:
Trench Formation under the Tunable Nanogap: Its Depth Depends on Maximum Strain and Periodicity
Authors: Park Daehwan , Lee Dukhyung , Moghaddam Mahsa Haddadi , Kim Dai-Sik
Published: October 2023

Metallic nanogaps have been studied for many years in the context of a significant amount of field enhancements. Nanogaps of macroscopic lengths for long-wave applications have attracted much interest, and recently one dimensional tunable nanogaps have been demonstrated using flexible PET substrates. For nanogaps on flexible substrates with applied tensile strain, large stress is expected in the vicinity of the gap, and it has been confirmed that several hundred nanometer-deep trenches form beneath the position of the nanogap because of this stress singularity. Here, we studied trench formation under nanogap structures using COMSOL Multiphysics 6.1. We constructed a 2D nanogap unit cell, consisting of gold film with a crack on a PDMS substrate containing a trench beneath the crack. Then, we calculated the von Mises stress at the bottom of the trench for various depths and spatial periods. Based on it, we derived the dependence of the trench depth on the strain and periodicity for various yield strengths. It was revealed that as the maximum tensile strain increases, the trench deepens and then diverges. Moreover, longer periods lead to larger depths for the given maximum strain and larger gap widths. These results could be applied to roughly estimate achievable gap widths and trench depths for stretchable zerogap devices.
Metronidazole Treatment Failure and Persistent BV Lead to Increased Frequencies of Activated T- and Dendritic-Cell Subsets
Authors: Qulu Wenkosi Perez , Mzobe Gugulethu , Mtshali Andile , Letsoalo Marothi Peter , Osman Farzana , San James Emmanuel , Kama Asavela Olona , Garrett Nigel , Mindel Adrian , Rompalo Anne , Liebenberg Lenine J. P. , Archary Derseree , Sivro Aida , Ngcapu Sinaye
Published: October 2023

Metronidazole (MDZ) treatment failure and bacterial vaginosis (BV) recurrence rates are high among African women. This cohort study identified genital immune parameters associated with treatment response by comparing vaginal microbiota and immune cell frequencies in endocervical cytobrushes obtained from 32 South African women with symptomatic BV pre- and post-metronidazole treatment. Cervical T- and dendritic-cell subsets were phenotyped using multiparameter flow cytometry and the composition of vaginal microbial communities was characterized using 16S rRNA gene sequencing. MDZ treatment led to a modest decrease in the relative abundance of BV-associated bacteria, but colonization with Lactobacillus species (other than L. iners) was rare. At 6 and 12 weeks, MDZ-treated women had a significant increase in the frequencies of CCR5+ CD4+ T cells and plasmacytoid dendritic cells compared to the pre-treatment timepoint. In addition, MDZ non-responders had significantly higher frequencies of activated CD4 T cells and monocytes compared to MDZ responders. We conclude that MDZ treatment failure was characterized by an increased expression of activated T- and dendritic-cell subsets that may enhance HIV susceptibility. These data suggest the need to further assess the long-term impact of MDZ treatment on mucosal immune response and the vaginal microbiota.
Late Cretaceous-Paleocene Arc and Back-Arc System in the Neotethys Ocean, Zagros Suture Zone
Authors: Mohammad Yousif , Abdulla Kurda , Azizi Hossein
Published: October 2023

The Bulfat Igneous Complex comprises the Bulfat and Walash groups and is situated in the Zagros Suture Zone, in the junction of Arabian and Eurasian plates. Zircon U-Pb data indicat an age of 63.7 ± 1.5 Ma for the trondhjemite rocks within the Bulfat group. Walash group is primarily composed of basalt to andesite rocks, interbedded with sedimentary rocks. Zircon U-Pb dating yields an age of 69.7 ± 2.7 Ma for the Walash group. Whole rocks chemistry shows that the Bulfat rocks have affinity to MORB and calc alkaline series but Walsh are mainly plot in the calc alkaline field. Whole rocks Sr-Nd isotope ratios show that the 143Nd/144Nd (i) changes from 0.51243 to 0.52189 and 87Sr/86Sr(i) ratios vary from 0.70345 to 0.7086. The calculated εNd(t) values, based on the CHUR, yield predominantly high positive values ranging from +6 to +8 for most samples. However, a few samples exhibit lower values (+2 to +3). Our data suggest that the interaction between lithospheric (depleted mantle, MORB-Like) and asthenospheric mantle (OIB-like) melts significantly controlled the magmatic evolution of the Bulfat group. The strong positive εNd(t) values (ranging from +6 to +8) align more consistently with a highly depleted lithospheric mantle source for the Walsh group. Therefore, the gradual transition from an arc signature at 70 Ma to a MORB signature around 63 Ma, occurred over a relatively short period of about 10 million years, and indicates the presence of an arc and back-arc system in the Neotethys ocean before the collision of the Arabian and Iran plates during the Cenozoic.
Copper-Bearing Magnetite and Delafossite in Copper Smelter Slags
Authors: Gezzaz Hassan , Ciobanu Cristiana L. , Cook Nigel J. , Ehrig Kathy , Slattery Ashley , Wade Benjamin , Yao Jie
Published: October 2023

The cooling paths and kinetics in the system Cu-Fe-O are investigated by the empirical micro- and nanoscale analysis of slags from the flash furnace smelter at Olympic Dam, South Australia. We aim to constrain the exsolution mechanism of delafossite (Cu1+Fe3+O2) from a spinel solid solution (magnetite, Fe3O4) and understand why cuprospinel (CuFe2O4) is never observed, even though, as a species isostructural with magnetite, it might be expected to form. Flash furnace slags produced in the direct-to-blister copper smelter at Olympic Dam contain four Cu-bearing phases: Cu-bearing magnetite, delafossite, metallic copper, and cuprite. Delafossite coexists with magnetite as rims and lamellar exsolutions, as well as bladed aggregates, associated with cuprite within Si-rich glass. The empirical compositions of magnetite and rim delafossite are (Fe2+6.89Cu2+0.86Co0.13Mg0.15Si0.02)8.05 (Fe3+15.52Al0.41Ti0.01Cr0.01)15.95O32, and (Cu1+0.993Co0.002Mg0.002)0.997(Fe3+0.957Al0.027Ti0.005Si0.004)0.993O2, respectively. The measured Cu content of magnetite represents a combination of a solid solution (~6 mol.% cuprospinel endmember) and exsolved delafossite lamellae. Atomic-resolution high-angle annular dark field scanning transmission electron microscope (HAADF STEM) imaging shows epitaxial relationships between delafossite lamellae and host magnetite. Defects promoting the formation of copper nanoparticles towards the lamellae margins suggest rapid kinetics. Dynamic crystallization under locally induced stress in a supercooled system (glass) is recognized from misorientation lamellae in delafossite formed outside magnetite grains. The observations are concordant with crystallization during the cooling of molten slag from 1300 °C to <1080 °C. Melt separation through an immiscibility gap below the solvus in the system Cu-Fe-O is invoked to form the two distinct delafossite associations: (i) melt-1 from which magnetite + delafossite form; and (ii) melt-2 from which delafossite + cuprite form. Such a path also corroborates the published data explaining the lack of cuprospinel as a discrete phase in the slag. Delafossite rims form on magnetite at a peritectic temperature of ~1150 °C via a reaction between the magnetite and copper incorporated in the oxide/Si-rich melt. The confirmation of such a reaction is supported by the observed misfit orientation (~10°) between the rim delafossite and magnetite. HAADF STEM imaging represents a hitherto underutilized tool for understanding pyrometallurgical processes, and offers a direct visualization of phase relationships at the smallest scale that can complement both experimental approaches and theoretical studies based on thermodynamic modelling.
A New and Rapid HPLC Method to Determine the Degree of Deacetylation of Glutaraldehyde-Cross-Linked Chitosan
Authors: Amamou Ons , Denis Jean-Philippe , Heinen Élise , Boubaker Taoufik , Cardinal Sébastien
Published: October 2023

Chitosan is a linear biopolymer composed of D-glucosamine and N-acetylglucosamine units. The percentage of D-glucosamine in the polymeric chain can vary from one sample to another and is expressed as the degree of deacetylation (DDA). Since this parameter has an impact on many properties, its determination is often critical, and potentiometric titration is a common analytical technique to measure the DDA. Cross-linking with glutaraldehyde is one of the most explored modifications of chitosan; however, the determination of the DDA for the resulting reticulated chitosan resins can be challenging. In this paper, we report a new, rapid, and efficient method to determine the DDA of glutaraldehyde-cross-linked chitosan resins via HPLC. This method relies on the use of 2,4-dinitrophenylhydrazine (DNPH) as a derivatizing agent to measure the level of reticulation of the polymer (LR) after the reticulation step. In this study, we prepare three calibration curves (with an R2 value over 0.92) for three series of reticulated polymers covering a large range of reticulation levels to demonstrate that a correlation can be established between the LR established via HPLC and the DDA obtained via titration. The polymers are derived from three different chitosan starting materials. These standard calibration curves are now used on a routine basis in our lab, and the HPLC method has allowed us to change our DDA analysis time from 20 h to 5 min.
Making Moco: A Personal History
Authors: Burgmayer Sharon J. Nieter
Published: October 2023

This contribution describes the path of my nearly forty-year quest to understand the special ligand coordinated to molybdenum and tungsten ions in their respective enzymes. Through this quest, I aimed to discover why nature did not simply use a methyl group on the dithiolene that chelates Mo and W but instead chose a complicated pyranopterin. My journey sought answers through the synthesis of model Mo compounds that allowed systematic investigations of the interactions between molybdenum and pterin and molybdenum and pterin-dithiolene and revealed special features of the pyranopterin dithiolene chelate bound to molybdenum.
Magnetic Bimerons in Cylindrical Nanotubes
Authors: Galvez David , Castro Mario , Bittencourt Guilherme , Carvalho Vagson , Allende Sebastian
Published: October 2023

This work presents the analysis of the stability of magnetic bimerons in a cylindrical nanotube. Through micromagnetic simulations, we study the influence of magnetic and geometrical parameters on the bimeron existence and size. The obtained results allow us to present diagram states showing the stability region of a bimeron as a function of the nanotube’s height and radius for different anisotropy and Dzyaloshinskii–Moriya interaction strengths. We also obtain two other magnetic states in the range of parameters where the bimeron is not stable: helicoidal and saturated states.
Assessment of the Tribological Performance of Electrospun Lignin Nanofibrous Web-Thickened Bio-Based Greases in a Nanotribometer
Authors: Borrego María , Kuhn Erik , Martín-Alfonso José E. , Franco José M.
Published: October 2023

The tribological performance of novel bio-based lubricating greases thickened with electrospun lignin nanostructures was investigated in a nanotribometer using a steel–steel ball-on-disc configuration. The impact of electrospun nanofibrous network morphology on friction and wear is explored in this work. Different lignin nanostructures were obtained with electrospinning using ethylcellulose or PVP as co-spinning polymers and subsequently used as thickeners in castor oil at concentrations of 10–30% wt. Friction and wear generally increased with thickener concentration. However, friction and wear decreased when using homogeneous bead-free nanofiber mats (with higher fiber diameter and lower porosity) rather than nanostructures dominated by the presence of particles or beaded fibers, which was favored by reducing the lignin:co-spinning polymer ratio.
Dual-Channel Switchable Metasurface Filters for Compact Spectral Imaging with Deep Compressive Reconstruction
Authors: Wang Chang , Liu Xinyu , Zhang Yang , Sun Yan , Yu Zeqing , Zheng Zhenrong
Published: October 2023

Spectral imaging technology, which aims to capture images across multiple spectral channels and create a spectral data cube, has been widely utilized in various fields. However, conventional spectral imaging systems face challenges, such as slow acquisition speed and large size. The rapid development of optical metasurfaces, capable of manipulating light fields versatilely and miniaturizing optical components into ultrathin planar devices, offers a promising solution for compact hyperspectral imaging (HSI). This study proposes a compact snapshot compressive spectral imaging (SCSI) system by leveraging the spectral modulations of metasurfaces with dual-channel switchable metasurface filters and employing a deep-learning-based reconstruction algorithm. To achieve compactness, the proposed system integrates dual-channel switchable metasurface filters using twisted nematic liquid crystals (TNLCs) and anisotropic titanium dioxide (TiO2) nanostructures. These thin metasurface filters are closely attached to the image sensor, resulting in a compact system. The TNLCs possess a broadband linear polarization conversion ability, enabling the rapid switching of the incidence polarization state between x-polarization and y-polarization by applying different voltages. This polarization conversion facilitates the generation of two groups of transmittance spectra for wavelength-encoding, providing richer information for spectral data cube reconstruction compared to that of other snapshot compressive spectral imaging techniques. In addition, instead of employing classic iterative compressive sensing (CS) algorithms, an end-to-end residual neural network (ResNet) is utilized to reconstruct the spectral data cube. This neural network leverages the 2-frame snapshot measurements of orthogonal polarization channels. The proposed hyperspectral imaging technology demonstrates superior reconstruction quality and speed compared to those of the traditional compressive hyperspectral image recovery methods. As a result, it is expected that this technology will have substantial implications in various domains, including but not limited to object detection, face recognition, food safety, biomedical imaging, agriculture surveillance, and so on.
Regular Exercise Improved Fatigue and Musculoskeletal Pain in Young Adult Psoriatic Patients without Psoriatic Arthritis
Authors: Diaz Antonio J. , Rosety Miguel A. , Armario Jose C. , Bandez Manuel J. , Garcia-Gomez Natalia , Sanchez-Sanchez Eduardo , Diaz Jara , Castejon-Riber Cristina , Bernardi Marco , Rosety-Rodriguez M Manuel , Ordonez Francisco J. , Rosety Ignacio
Published: October 2023

Fatigue and musculoskeletal pain are also frequent in patients with psoriasis (PsO) without arthritis (PsA). The current study aimed to assess the impact of an intervention program based on aerobic training to reduce fatigue and musculoskeletal pain in patients with PsO without PsA. A total of 118 male patients with PsO volunteered in the current interventional study and were randomly allocated to the experimental (n = 59) or control group (n = 59). The intervention consisted of a 16-week aerobic training program on a treadmill, three sessions per week, consisting of a warm-up, 35–50 min treadmill exercise (increasing 5 min/4 weeks) at a work intensity of 50–65% of peak heart-rate (increasing 5%/4 weeks), and cooling-down. The functional assessment of chronic illness therapy fatigue scale (FACIT-Fatigue), health assessment questionnaire disability index (HAQ-DI), and visual analog scale (VAS) were compared pre and post intervention. Nutritional intake, maximal aerobic power, lipid profile, serum markers of muscle damage, and body composition were also assessed. When compared to baseline, FACIT-Fatigue, HAQ-DI, and VAS scores were significantly improved without increasing markers of muscle damage. Fat mass percentage, lipid profile, and maximal oxygen consumption were also improved. In conclusion, a 16-week aerobic training program at moderate intensity was safe, well tolerated, and effective in psoriatic patients without PsA. Long-term follow-up studies are required to examine whether these promising results may improve clinical outcomes.
A New Dietary Fiber Can Enhance Satiety and Reduce Postprandial Blood Glucose in Healthy Adults: A Randomized Cross-Over Trial
Authors: Wu Simou , Jia Wen , He Huimin , Yin Jun , Xu Huilin , He Chengyuan , Zhang Qinqiu , Peng Yue , Cheng Ruyue
Published: October 2023

Background: Dietary fiber plays a potential role in regulating energy intake and stabilizing postprandial blood glucose levels. Soluble dietary fiber has become an important entry point for nutritional research on the regulation of satiety. Methods: this was a double-blind, randomized cross-over trial enrolling 12 healthy subjects to compare the effects of RPG (R+PolyGly) dietary fiber products (bread, powder, and capsule) and pectin administered with a standard meal on satiety, blood glucose, and serum insulin level. Results: Adding 3.8% RPG dietary fiber to bread significantly increased the volume, water content, hardness, and chewiness of bread compared to 3.8% pectin bread and white bread and significantly improved the sensory quality of bread. RPG bread had better appetite suppression effects at some time points than the other two groups and the best postprandial blood glucose lowering effects among the three groups. Administration of RPG capsules containing 5.6 g of RPG dietary fiber with meals improved satiety and reduced hunger compared to 6 g of RPG powder and 6 g of pectin, which had the greatest effect on suppressing appetite and reducing prospective food consumption. The peak level of serum glucagon-like peptide-1 (GLP-1) in the RPG capsule group (578.17 ± 19.93 pg/mL) was significantly higher than that in other groups at 0 min and 30 min after eating. RPG powder had the best effect in reducing postprandial blood glucose and increasing serum insulin levels; the total area under the curve (AUC) of serum insulin with RPG powder was higher than other groups (5960 ± 252.46 μU min/mL). Conclusion: RPG dietary fiber products can improve the sensory properties of food, reduce postprandial blood glucose, and enhance satiety, especially in capsule and powder forms. Further research on the physiological effects of RPG dietary fiber is required to facilitate its use as a functional ingredient in food products.
Modulatory Properties of Vitamin D in Type 2 Diabetic Patients: A Focus on Inflammation and Dyslipidemia
Authors: MacGirlley Rizqah , Phoswa Wendy N. , Mokgalaboni Kabelo
Published: October 2023

Background: Evidence from preclinical studies has found a correlation between the development of type 2 diabetes (T2D) and vitamin D deficiency. However, evidence from randomized controlled trials (RCTs) revealed inconclusive results on vitamin D supplementation. We explored the effect of vitamin D on inflammation and dyslipidemia in T2D. Methods: We comprehensively searched for RCTs evaluating the effect of vitamin D in T2D on PubMed. Data were analyzed using Review Manager 5.3 and reports, such as standardized mean difference (SMD) and 95% confidence intervals (CI) at a 5% significant level using a random effect model. Results: This study revealed a significant reduction in tumor necrosis factor-alpha (TNF-α) SMD = (−0.51, 95%CI (−0.93, −0.09); p = 0.02), high sensitivity C-reactive protein (hs-CRP) SMD = (−1.06, 95%CI (−1.67, −0.45); p < 0.05) in vitamin D compared to placebo. Additionally, interleukin-6 (IL-6) exhibited a marginal effect SMD = (−0.52, 95%CI (−1.05, 0.01), p = 0.05). Furthermore, a significant reduction in the level of triglycerides SMD = (−0.65, 95%CI (−1.11, −0.18), p < 0.05) was observed, concomitant to a significantly increased high-density lipoprotein (HDL) level SMD = (0.53, 95%CI (0.08, 0.98), p = 0.02). However, no statistically significant changes were observed in total cholesterols SMD = (−0.16, 95%CI (−0.57, 0.24), p = 0.43) and low-density lipoprotein (LDL) SMD = (−0.06, 95%CI (−0.37, 0.24), p = 0.67). Conclusions: These findings suggest that vitamin D supplementation may be beneficial in ameliorating inflammation and dyslipidemia in T2D patients.
Impact of Nutrition on Female Reproductive Disorders
Authors: Ciarmela Pasquapina , Greco Stefania
Published: October 2023

The female reproductive system is a delicate and complex system in the body that can be affected by many disorders [...]
HIV Care Profiling and Delivery Status in the Mobile Health Clinics of eThekwini District in KwaZulu Natal, South Africa: A Descriptive Evaluation Study
Authors: Ngcobo Silingene Joyce , Makhado Lufuno , Sehularo Leepile Alfred
Published: October 2023

Mobile health clinics (MHCs) serve as an alternative HIV care delivery method for the HIV-burdened eThekwini district. This study aimed to describe and profile the HIV care services provided by the MHCs through process evaluation. A descriptive cross-sectional quantitative evaluation study was performed on 137 MHCs using total population sampling. An online data collection method using a validated 50-item researcher-developed instrument was administered to professional nurses who are MHC team leaders, following ethical approval from the local university and departments of health. Descriptive statistics were used to analyze the data. The results described that HIV care services are offered in open spaces (43%), community buildings (37%), solid built buildings called health posts (15%), vehicles (9%), and tents (2%) with no electricity (77%), water (55%), and sanitation (64%). Adults (97%) are the main recipients of HIV care in MHCs (90%) offering antiretroviral therapy (95%). Staff, monitoring, and retaining care challenges were noted, with good linkage (91%) and referral pathways (n = 123.90%). In conclusion, the standardization and prioritization of HIV care with specific contextual practice guidelines are vital.
Immunoblot Criteria for Diagnosis of Lyme Disease: A Comparison of CDC Criteria to Alternative Interpretive Approaches
Authors: Porwancher Richard , Levin Andrew , Trevejo Rosalie
Published: October 2023

The current Centers for Disease Control and Prevention (CDC) interpretive criteria for serodiagnosis of Lyme disease (LD) involve a two-tiered approach, consisting of a first-tier EIA, IFA, or chemiluminescent assay, followed by confirmation of positive or equivocal results by either immunoblot or a second-tier EIA. To increase overall sensitivity, single-tier alternative immunoblot assays have been proposed, often utilizing antigens from multiple Borrelia burgdorferi strains or genospecies in a single immunoblot; including OspA and OspB in their antigen panel; requiring fewer positive bands than permitted by current CDC criteria; and reporting equivocal results. Published reports concerning alternative immunoblot assays have used relatively small numbers of LD patients and controls to evaluate novel multi-antigen assays and interpretive criteria. We compared the two most commonly used alternative immunoblot interpretive criteria (labeled A and B) to CDC criteria using data from multiple FDA-cleared IgG and IgM immunoblot test kits. These single-tier alternative interpretive criteria, applied to both IgG and IgM immunoblots, demonstrated significantly more false-positive or equivocal results in healthy controls than two-tiered CDC criteria (12.4% and 35.0% for Criteria A and B, respectively, versus 1.0% for CDC criteria). Due to limited standardization and high false-positive rates, the presently evaluated single-tier alternative immunoblot interpretive criteria appear inferior to CDC two-tiered criteria.
Identification of a Novel Polerovirus in Cocoa (Theobroma cacao) Germplasm and Development of Molecular Methods for Use in Diagnostics
Authors: Ullah Ihsan , Kamran Muhammad , Dunwell Jim M.
Published: October 2023

The cocoa crop (Theobroma cacao L.) is known to be a host for several badnaviruses, some of which cause severe disease, while others are asymptomatic. Recently, the first preliminary evidence has been published concerning the occurrence of a polerovirus in cacao. We report here the first near-complete genome sequence of cacao polerovirus (CaPV) by combining bioinformatic searches of cacao transcript databases, with cloning from the infected germplasm. The reported novel genome has all the genome features known for poleroviruses from other species. Pairwise identity analyses of RNA-dependent RNA polymerase and coat protein indicates < 60% similarity of CaPV with any reported poleroviruses; hence, we propose that the polerovirus isolate reported in this study is a novel polerovirus. The genome sequence information was also used to develop a multiplex RT-PCR assay, which was applied to screen a selected range of germplasms and to identify several infected clones. Although there is no evidence that this virus causes any severe disease, this new information, together with a robust diagnostic assay, are of strategic importance in developing protocols for the safe international transfer of cacao germplasms.
Super-Resolution Imaging Enhancement through a 2D Scanning Galvanometer: Algorithm Formulation and Application in Aerial Optoelectronic Systems
Authors: Ma Tianxiang , Liang Chao , Han Yuting , Yuan Fang , Meng Lingtong , Xu Yongsen , Shen Honghai , Liu Yunqing
Published: October 2023

As the fields of aviation and aerospace optics continue to evolve, there is an increasing demand for enhanced detection capabilities in equipment. Nonetheless, in applications where both optical and mechanical constraints are stringent, the continuous expansion of optical aperture and focal length is impractical. Given the existing technological landscape, employing super-resolution algorithms to enhance the imaging capability of optical systems is both practical and highly relevant. This study capitalizes on using a 2D scanning galvanometer in optical systems to acquire micro-displacement information. Initially, an imaging model for optical systems equipped with a 2D scanning galvanometer was established, and the displacement vectors for both forward and sweep image motions were defined. On this foundation, we incorporated micro-displacement information that can induce high-frequency aliasing. Subsequently, the motion paths of the galvanometer were planned and modeled. To align image sequences with micro-displacement correlations, the Lucas–Kanade (L-K) optical flow method was employed with multi-layer pyramid iteration. Then, super-resolution reconstruction was performed using kernel regression techniques. Ultimately, we tested the algorithm on an aeronautical optoelectronic pod to evaluate its impact on optical resolution and imaging quality. Compared with the original images, the 16-frame image demonstrated a 39% improvement in optical resolution under laboratory conditions. Moreover, the algorithm exhibited satisfactory performance under both nighttime and daytime conditions, as well as during aerial tests.
Examining the Corn Seedling Emergence–Temperature Relationship for Recent Hybrids: Insights from Experimental Studies
Authors: Beegum Sahila , Walne Charles Hunt , Reddy Krishna N. , Reddy Vangimalla , Reddy Kambham Raja
Published: October 2023

Corn seedling emergence is a critical factor affecting crop yields. Accurately predicting emergence is crucial for precise crop growth and development simulation in process-based crop models. While various experimental studies have investigated the relationship between corn seedling emergence and temperature, there remains a scarcity of studies focused on newer corn hybrids. In the present study, statistical models (linear and quadratic functional relationships) are developed based on the seedling emergence of ten current corn hybrids, considering soil and air temperatures as influencing factors. The data used for model development are obtained from controlled soil plant atmospheric research chamber experiments focused on corn seedling emergence at five different temperatures. Upon evaluating the developed models, the quadratic model relating the air temperature with time to emergence was found more accurate for all corn hybrids (coefficient of determination (R2): 0.97, root mean square error (RMSE): 0.42 day) followed by the quadratic model based on soil temperature (R2: 0.96, RMSE: 1.42 days), linear model based on air (R2: 0.94, RMSE: 0.53 day) and soil temperature (R2: 0.94, RMSE: 0.70 day). A growing degree day (GDD)-based model was also developed for the newer hybrids. When comparing the developed GDD-based model with the existing GDD models (based on old hybrids), it was observed that the GDD required for emergence was 16% higher than the GDD used in the current models. This showed that the existing GDD-based models need to be revisited when adopted for newer hybrids and adapted to corn crop simulation models. The developed seedling emergence model, integrated into a process-based corn crop simulation model, can benefit farmers and researchers in corn crop management. It can aid in optimizing planting schedules, supporting management decisions, and predicting corn crop growth, development, and it yields more accurately.
Seed Pelleting with Gum Arabic-Encapsulated Biocontrol Bacteria for Effective Control of Clubroot Disease in Pak Choi
Authors: Abdukerim Rizwangul , Xiang Sheng , Shi Yanxia , Xie Xuewen , Li Lei , Chai Ali , Li Baoju , Fan Tengfei
Published: October 2023

Clubroot is one of the most serious soil-borne diseases on crucifer crops worldwide. Seed treatment with biocontrol agents is an effective and eco-friendly way to control clubroot disease. However, there is a big challenge to inoculating the seed with bacterial cells through seed pelleting due to the harsh environment on the seed surface or in the rhizosphere. In this study, a method for microbial seed pelleting was developed to protect pak choi seedlings against clubroot disease. Typically, a biocontrol bacterium, Paenibacillus polymyxa ZF129, was encapsulated by the spray-drying method with gum arabic as wall material, and then pak choi seeds were pelleted with the microencapsulated Paenibacillus polymyxa ZF129 (ZF129m). The morphology, storage stability, and release behavior of ZF129 microcapsules were evaluated. Compared with the naked Paenibacillus polymyxa ZF129 cells, encapsulated ZF129 cells showed higher viability during ambient storage on pak choi seeds. Moreover, ZF129m-pelleted seeds showed higher control efficacy (71.23%) against clubroot disease than that of nonencapsulated ZF129-pelleted seeds (61.64%) in pak choi. Seed pelleting with microencapsulated biocontrol Paenibacillus polymyxa ZF129 proved to be an effective and eco-friendly strategy for the control of clubroot disease in pak choi.
Enhancing Maize Productivity and Soil Health under Salt Stress through Physiological Adaptation and Metabolic Regulation Using Indigenous Biostimulants
Authors: Ouhaddou Redouane , Meddich Abdelilah , Ikan Chayma , Lahlali Rachid , Ait Barka Essaid , Hajirezaei Mohammad-Reza , Duponnois Robin , Baslam Marouane
Published: October 2023

Salinity poses a persistent threat to agricultural land, continuously jeopardizing global food security. This study aimed to enhance sweet corn (SC) fitness under varying levels of salinity using indigenous biostimulants (BioS) and to assess their impacts on plant performance and soil quality. The experiment included control (0 mM NaCl), moderate stress (MS; 50 mM NaCl), and severe stress (SS; 100 mM NaCl) conditions. Indigenous biostimulants, including compost (C), Bacillus sp., Bacillus subtilis (R), and a consortium of arbuscular mycorrhizal fungi (A) were applied either individually or in combination. Growth traits, physiological and biochemical parameters in maize plants, and the physico–chemical properties of their associated soils were assessed. SS negatively affected plant growth and soil quality. The RC combination significantly improved plant growth under SS, increasing aerial (238%) and root (220%) dry weights compared to controls. This treatment reduced hydrogen peroxide by 54% and increased peroxidase activity by 46% compared to controls. The indigenous biostimulants, particularly C and R, enhanced soil structure and mineral composition (K and Mg). Soil organic carbon and available phosphorus increased notably in C-treated soils. Furthermore, RC (437%) and CAR (354%) treatments exhibited a significant increase in glomalin content under SS. Indigenous biostimulants offer a promising strategy to mitigate salinity-related threats to agricultural land. They improve plant fitness, fine-tune metabolism, and reduce oxidative stress. In addition, the biostimulants improved the soil structure and mineral composition, highlighting their potential for reconstitution and sustainability in salt-affected areas. This approach holds promise for addressing salinity-related threats to global food security.
Polymer Hydrogels and Frontal Polymerization: A Winning Coupling
Authors: Mariani Alberto , Malucelli Giulio
Published: October 2023

Polymer hydrogels are 3D networks consisting of hydrophilic crosslinked macromolecular chains, allowing them to swell and retain water. Since their invention in the 1960s, they have become an outstanding pillar in the design, development, and application of engineered polymer systems suitable for biomedical and pharmaceutical applications (such as drug or cell delivery, the regeneration of hard and soft tissues, wound healing, and bleeding prevention, among others). Despite several well-established synthetic routes for developing polymer hydrogels based on batch polymerization techniques, about fifteen years ago, researchers started to look for alternative methods involving simpler reaction paths, shorter reaction times, and lower energy consumption. In this context, frontal polymerization (FP) has undoubtedly become an alternative and efficient reaction model that allows for the conversion of monomers into polymers via a localized and propagating reaction—by means of exploiting the formation and propagation of a “hot” polymerization front—able to self-sustain and propagate throughout the monomeric mixture. Therefore, the present work aims to summarize the main research outcomes achieved during the last few years concerning the design, preparation, and application of FP-derived polymeric hydrogels, demonstrating the feasibility of this technique for the obtainment of functional 3D networks and providing the reader with some perspectives for the forthcoming years.
Plasma-Treated Electrospun PLGA Nanofiber Scaffold Supports Limbal Stem Cells
Authors: Jafar Hanan , Ahmed Khalid , Rayyan Rama , Sotari Shorouq , Buqain Rula , Ali Dema , Al Bdour Muawyah , Awidi Abdalla
Published: October 2023

The corneal epithelial layer is continuously replaced by limbal stem cells. Reconstructing this layer in vitro using synthetic scaffolds is highly needed. Poly-lactic-co-glycolic acid (PLGA) is approved for human use due to its biocompatibility and biodegradability. However, PLGA is hydrophobic, preventing cell adherence to PLGA membranes. PLGA scaffolds were prepared by electrospinning on a custom-made target drum spinning at a rate of 1000 rpm with a flow rate of 0.5 mL/h and voltage at 20 kV, then treated with oxygen plasma at 30 mA using a vacuum coater. Scaffolds were characterized by SEM, mechanically by tensile testing, and thermally by DSC and TGA. In vitro degradation was measured by weight loss and pH drop. Wettability was assessed through water uptake and contact angles measurements. Human limbal stem cells (hLSCs) were isolated and seeded on the scaffolds. Cell attachment and cytotoxicity assay were evaluated on day 1 and 5 after cell seeding. SEM showed regular fiber morphology with diameters ranging between 150 nm and 950 nm. Tensile strength demonstrated similar average stress values for both plasma- and non-plasma-treated samples. Scaffolds also showed gradual degradability over a period of 7–8 weeks. Water contact angle and water absorption were significantly enhanced for plasma-treated scaffolds, indicating a favorable increase in their hydrophilicity. Scaffolds have also supported hLSCs growth and attachment with no signs of cytotoxicity. We have characterized a nanofiber electrospun plasma-treated PLGA scaffold to investigate the mechanical and biological properties and the ability to support the attachment and maintenance of hLSCs.
Investigation of Pressure Variations in Hose Pumps under Different Flow Regimes Using Bidirectional Fluid–Structure Interaction
Authors: Wang Mengfan , Zhang Lixin , Wang Wendong , Ma Xiao , Hu Xue , Zhao Jiawei , Chao Xuewei
Published: October 2023

Hose pumps, renowned for their ability to efficiently transport highly viscous and corrosive fluids, hold an irreplaceable position in numerous engineering domains. With a wide range of fluid types being transported by hose pumps, the study of pressure variations during the conveyance of different fluid states is of paramount importance, as it positively contributes to optimizing hose pump structures, reducing noise, and enhancing hose pump longevity. To investigate pressure variations in hose pumps during the conveyance of varying fluid states, this paper employs a bidirectional fluid–structure coupling method and utilizes commercial finite element software, ANSYS. The research validates the causes of variations in hose pumps during fluid conveyance and examines the overall pressure distribution within the fluid domain of hose pumps conveying different fluid states at varying rotor speeds. The results indicate that when the fluid within the hose pump is in a turbulent state, pressure variations exhibit multiple minor amplitude oscillations, whereas in a laminar state, pressure variations display fewer oscillations but with more significant amplitudes. Moreover, higher rotor speeds exacerbate pressure variations. Recommendations include optimizing the shape of the squeezing roller and enhancing pressure variation control through shell angle optimization.
Mechanical Properties of Buried Gas Pipeline under Traffic Loads
Authors: Zhang Jiaxin , Gu Xiaoting , Zhou Yutong , Wang Yu , Zhang Hailun , Zhang Yuan
Published: October 2023

Dynamic loads generated by heavy vehicles are among the loads resisted by pipelines buried under road surfaces. Most recent analyses are based on static assumptions; however, in practice, vehicle loads change dynamically. In this study, the finite element model of the pipe–soil interaction of a buried pipeline was established using the ABAQUS 2020 finite element software, and dynamic loads were applied above the model soil to simulate the influence of vehicles above the highway on the buried X80 pipeline. The mechanical responses of different influencing factors to buried pipelines were analyzed. Increasing the pipe diameter and burial depth decreases the effect of vehicle rolling on the buried pipeline. The mass of the vehicle is the most significant factor that influences the stress and strain on the pipeline. The stress increase of the conventional vehicle load on the X80 gas pipeline does not exceed 10 MPa, and the maximum shape variable of the pipeline is within 13 mm. This study provides a data reference and a risk warning regarding the rolling of buried natural gas pipelines under a single vehicle load.
Online Dynamic Optimization of Multi-Rate Processes with the Case of a Fluid Catalytic Cracking Unit
Authors: Zhang Jianfei , Lin Jiajiang , Xu Feng , Luo Xionglin
Published: October 2023

Due to operational limitations in the industrial field, the operating variables of fluid catalytic cracking units (FCCU) are of multiple operating frequencies, which are CO combustion promoter amount, recycle slurry flow rate, combustion air flow rate, heat escape, and reaction temperature, from low frequency to high frequency. There are usually two schemes for operation optimization of FCCU. The former is called single-rate, single-window optimization, whose operating variables are optimized only once in the whole operation cycle, which is easy to achieve, but the optimization effect is poor. The latter is called single-rate multi-window optimization, whose operating variables are optimized repeatedly and whose operation cycle is discretized into multiple optimization periods with the same frequency, which costs a heavy calculation burden and cannot adapt to the optimization variables with multiple operating frequencies. So, a multi-rate, variable-window online dynamic optimization method is proposed. In an operation cycle, the high-frequency operating variable is optimized in a short optimization period, and the low-frequency operating variable is optimized in a long optimization period; each optimization period has integer multiples to the minimum optimization period. Each optimized result for each optimization period is put into use online immediately. The optimization model involves the time domain differential equations, integral cost objective function, and measured disturbances. The experimental results show that compared with the single-rate, single-window optimization method and single-rate multi-window optimization method, the optimization effect of multi-rate, variable-window online dynamic optimization is better than single-rate, single-window optimization but worse than single-rate multi-window optimization. However, the optimization results are consistent with the operation frequency of each optimization variable, which can be implemented in complex chemical processes and increase certain economic benefits.
Research on Diesel Engine Speed Control Based on Improved Salp Algorithm
Authors: Zeng Boshun , Shen Qianqiao , Wang Guiyong , Wang Yuhua , Zhao You , He Shuchao , Yu Xuan
Published: October 2023

To better regulate the speed of diesel engines and optimize the speed overshoot and fast response, a speed control method combining the improved salp swarm algorithm (ISSA) with the proportional integral and differential (PID) controller was proposed. A real-time simulation model for a high-pressure common rail diesel engine was established. Addressing the challenges of the salp swarm algorithm (SSA), such as uneven population distribution and its tendency to become trapped in local optima, logistic-tent chaotic mapping, adaptive parameters was introduced, as well as adaptive dynamic inertia weights, elite strategy, and a dynamic inverse strategy. These enhancements bolstered the algorithm’s precision and efficiency in both global and local searches. Using the enhanced SSA, the parameters of the PID controller for the diesel engine model was optimized. The results indicated that the ISSA offers superior parameter identification precision, strengthening speed control stability. During sudden changes in speed and load, the overshoot decreased by an average of more than 30.3% and more than 8.6%, respectively. Moreover, the settling time decreased by an average of more than 0.76 s and 1.52 s, respectively, significantly enhancing the quality of diesel engine speed control.
A General Relative Radiometric Correction Method for Vignetting Noise Drift
Authors: Fan Liming , Yu Shuhai , Zhong Xing , Chen Maosheng , Wang Dong , Cao Jinyan , Cai Xiyan
Published: October 2023

Due to the limitation of the number of sensor pixels, optical splicing is commonly used to improve the imaging width of remote sensing satellites, and this optical stitching can cause vignetting in the image data of adjacent sensors. The weak energy, low signal-to-noise ratio, and poor response stability of vignetting are key factors that restrict the relative radiometric correction of optical splicing remote satellites. This paper proposes a stability analysis method and a relative radiometric correction method for vignetting. First, we analyzed the stability of the response and the noise impact of vignetting. Massive data from the Jilin-1 GF03D satellites was used to analyze the stability of the response using the vignetting stability analysis method. Secondly, the data on the deep sea during nighttime (DDSN) of Jilin-1 GF03D satellites was used to obtain the characteristics of the sensors’ noise. Thirdly, by building a noise drift model, we calculated the coefficient of the noise drift according to its characteristics. Using the coefficient to eliminate the noise drift of each pixel in vignetting can improve the response stability of vignetting. The average response stability increased by 37.64% by this method. Finally, the automatic relative radiometric correction method was completed through histogram matching. Furthermore, we proposed color aberration metrics (CAMs) to evaluate the multi-spectral images after relative radiometric correction, and massive data from the 16 satellites of Jilin-1 GF03D was used to verify the effectiveness and generality. The experimental results show that the average CAM of the images increased by 15.97% using the proposed method compared to the traditional method.
Using Multi-Spectral Remote Sensing for Flood Mapping: A Case Study in Lake Vembanad, India
Authors: Kulk Gemma , Sathyendranath Shubha , Platt Trevor , George Grinson , Suresan Anagha Kunhimuthappan , Menon Nandini , Evers-King Hayley , Abdulaziz Anas
Published: October 2023

Water is an essential natural resource, but increasingly water also forms a threat to the human population, with floods being the most common natural disaster worldwide. Earth Observation has the potential for developing cost-effective methods to monitor risk, with free and open data available at the global scale. In this study, we present the application of remote sensing observations to map flooded areas, using the Vembanad-Kol-Wetland system in the southwest of India as a case study. In August 2018, this region experienced an extremely heavy monsoon season, which caused once-in-a-century floods that led to nearly 500 deaths and the displacement of over a million people. We review the use of existing algorithms to map flooded areas in the Lake Vembanad region using the spectral reflectances of the green, red and near-infrared bands from the MSI sensor on board Sentinel-2. Although the MSI sensor has no cloud-penetrating capability, we show that the Modified Normalised Difference Water Index and the Automated Water Extraction Index can be used to generate flood maps from multi-spectral visible remote sensing observations to complement commonly used SAR-based techniques to enhance temporal coverage (from 12 to 5 days). We also show that local knowledge of paddy cultivation practices can be used to map the manoeuvring of water levels and exclude inundated paddy fields to improve the accuracy of flood maps in the study region. The flood mapping addressed here has the potential to become part of a solution package based on multi-spectral visible remote sensing with capabilities to simultaneously monitor water quality and risk of human pathogens in the environment, providing additional important services during natural disasters.