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18 pages, 2404 KiB  
Article
Efficient Production of High-Concentration Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from CO2 Employing the Recombinant of Cupriavidus necator
by Kenji Tanaka, Izumi Orita and Toshiaki Fukui
Bioengineering 2025, 12(6), 557; https://doi.org/10.3390/bioengineering12060557 - 22 May 2025
Viewed by 757
Abstract
A copolymer of 3-hydroxybutyrate (3HB) and 3-hydoxyhexanoate (3HHx), PHBHHx, is a practical biodegradable plastic, and at present, the copolymer is produced at commercial scale via heterotrophic cultivation of an engineered strain of a facultative hydrogen-oxidizing bacterium, Cupriavidus necator, using vegetable oil as [...] Read more.
A copolymer of 3-hydroxybutyrate (3HB) and 3-hydoxyhexanoate (3HHx), PHBHHx, is a practical biodegradable plastic, and at present, the copolymer is produced at commercial scale via heterotrophic cultivation of an engineered strain of a facultative hydrogen-oxidizing bacterium, Cupriavidus necator, using vegetable oil as the carbon source. In our previous report, we investigated PHBHHx production from CO2 via pH-stat jar cultivation of the newly created recombinants of C. necator under autotropic conditions, feeding the inorganic substrate gas mixture (H2/O2/CO2 = 80:10:10 v/v%) into a recycled-gas closed-circuit (RGCC) culture system. The dry cell weight (DCW) and PHBHHx concentration with the best strain MF01/pBPP-ccrMeJAc-emd increased to 59.62 ± 3.18 g·L−1 and 49.31 ± 3.14 g·L−1, respectively, after 216 h. In this study, we investigated the high-concentration production of PHBHHx with a shorter cultivation time by using a jar fermenter equipped with a basket-shaped agitator to enhance oxygen transfer in the culture medium and by continuously supplying the gases with higher O2 concentrations to maintain the gas composition within the reservoir at a constant ratio. The concentrations of ammonium and phosphate in the culture medium were maintained at low levels. As a result, the DCW and PHBHHx concentrations increased to 109.5 ± 0.30 g·L−1 and 85.2 ± 0.62 g·L−1 after 148 h, respectively. The 3HHx composition was 10.1 ± 0.693 mol%, which is suitable for practical applications. Full article
(This article belongs to the Special Issue Advances in Polyhydroxyalkanoate (PHA) Production, 4th Edition)
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20 pages, 4397 KiB  
Article
Ridesharing Methods for High-Speed Railway Hubs Considering Path Similarity
by Wendie Qin, Liangjie Xu, Di Zhu, Wanheng Liu and Yan Li
Sustainability 2025, 17(7), 2975; https://doi.org/10.3390/su17072975 - 27 Mar 2025
Viewed by 302
Abstract
We propose a hub ridesharing method that considers path similarity to swiftly evacuate high volumes of passengers arriving at a high-speed railway hub. The technique aims to minimize total mileage and the number of service vehicles, considering the characteristics of hub passengers, such [...] Read more.
We propose a hub ridesharing method that considers path similarity to swiftly evacuate high volumes of passengers arriving at a high-speed railway hub. The technique aims to minimize total mileage and the number of service vehicles, considering the characteristics of hub passengers, such as the constraints of large luggage, departure times, and arrival times. Meanwhile, to meet passengers’ expectations, a path morphology similarity indicator combining directional and locational features is developed and used as a crucial criterion for passenger matching. A two-stage algorithm is designed as a solution. Passenger requests are clustered based on path vector similarity in the first stage using a heuristic approach. In the second stage, we employ an adaptive large-scale neighborhood search to form passenger matches and shared routes. The experiments demonstrate that this method can reduce operational costs, enhance computational efficiency, and shorten passenger wait times. Taking path similarity into account significantly decreases passenger detour distances. It improves the Jaccard coefficient (JAC) of post-ridesharing paths, fulfilling the passenger’s psychological expectation that the shared route will closely resemble the original one. Full article
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21 pages, 3931 KiB  
Article
Effects of Sinensetin, Eupatilin, and Jaceosidin on Human Melanogenesis: A Pilot Study
by Shilpi Goenka
Future Pharmacol. 2025, 5(1), 12; https://doi.org/10.3390/futurepharmacol5010012 - 14 Mar 2025
Viewed by 751
Abstract
Background/Objectives: Flavones, a class of plant-based flavonoids, have demonstrated conflicting anti-melanogenic activities in mouse and human melanocytes. Sinensetin (SNT), a polymethoxyflavone, has shown pro-melanogenic activity in B16F10 mouse melanoma (MM) cells, while eupatilin (EU) and jaceosidin (JAC), two flavones that are structural analogs [...] Read more.
Background/Objectives: Flavones, a class of plant-based flavonoids, have demonstrated conflicting anti-melanogenic activities in mouse and human melanocytes. Sinensetin (SNT), a polymethoxyflavone, has shown pro-melanogenic activity in B16F10 mouse melanoma (MM) cells, while eupatilin (EU) and jaceosidin (JAC), two flavones that are structural analogs of SNT, have not been evaluated for their effects on melanogenesis yet. Methods: Herein, the effects of SNT, EU, and JAC on melanogenesis in MNT-1 cells (human melanoma) and HEMn-DP cells (primary human melanocytes) have been examined. The mushroom tyrosinase (TYR) activity was tested in cell-free conditions, followed by examination of the cytotoxicity of the compounds via the Alamar Blue (AB) assay. Cellular melanin production and TYR activity were estimated in MNT-1 cells. The compounds were further examined in primary human melanocytes for melanin production, TYR activity, and protein levels. Results: Our findings show that SNT was a potent inhibitor of TYR activity in a cell-free assay, while EU and JAC had no effect. However, both SNT and EU were shown to exhibit anti-melanogenic activity (that was reversible) in human cells, while JAC was ineffective and cytotoxic. Conclusions: SNT and EU are potential novel candidates for hyperpigmentation treatment without cytotoxicity. Additional studies are warranted to elucidate the signaling mechanisms that govern their anti-melanogenesis action. Future research is necessary to assess the anti-melanogenic effectiveness of SNT/EU using 3D skin tissue equivalents and to select the optimal candidate. Full article
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20 pages, 7405 KiB  
Article
TG-MS Analysis of the Effect of Variations in Coal Particle Size on Combustion Characteristics and Kinetic Parameters
by Jinyang Zhang, Guoliang Song, Weijian Song and Hongliang Ding
Energies 2025, 18(6), 1347; https://doi.org/10.3390/en18061347 - 10 Mar 2025
Viewed by 668
Abstract
This study investigated the influence of particle size on combustion performance using equivalent characteristic spectrum analysis (ECSA) on a TG-MS platform. The experiments were conducted at heating rates of 10 °C/min and 20 °C/min for three granular coal types with particle sizes of [...] Read more.
This study investigated the influence of particle size on combustion performance using equivalent characteristic spectrum analysis (ECSA) on a TG-MS platform. The experiments were conducted at heating rates of 10 °C/min and 20 °C/min for three granular coal types with particle sizes of 1 mm, 4 mm, and 8 mm. The results showed that the ignition temperature, burnout temperature, and burnout time generally increased with particle size, while the combustion characteristic index for the 8 mm particles was 28.81% lower than that for 1 mm particles. The particle size effects were more pronounced at lower heating rates. Combustion kinetics revealed that the pre-combustion endothermic stage had a significant impact on the ignition temperature, followed by the volatilization stage. For Shenmu bituminous coal (SBC), a 1 kJ/mol reduction in apparent activation energy during the endothermic stage increased the ignition temperature by 13.02 °C (10 °C/min) or 17.11 °C (20 °C/min). Similar trends were observed for Datong bituminous coal (DBC) and Jincheng anthracite coal (JAC). A gas product analysis indicated that the peak release temperatures rose with particle size, and particle size variations affected the maximum release rates and combustion stage duration. Smaller particles generally released less NO during combustion. Full article
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13 pages, 7079 KiB  
Article
A Study of the Performance of Dissimilar Pulsed-Laser-Welded JSC590R/JAC980YL Steel Joints of Differential Thickness
by Rui Zhang, Qiaobo Feng, Chunliang Wang, Shuai Tian, Sizhe Niu and Ming Lou
Metals 2024, 14(12), 1352; https://doi.org/10.3390/met14121352 - 27 Nov 2024
Viewed by 861
Abstract
To reveal the correlation between the mechanical properties of JSC590R/JSC980YL steel pulse-laser-welded joints and welding parameters, this study adopts the response surface analysis test method to determine the welding parameters, and examined the macroscopic morphology, microstructure, microhardness, and tensile properties of the cross-section [...] Read more.
To reveal the correlation between the mechanical properties of JSC590R/JSC980YL steel pulse-laser-welded joints and welding parameters, this study adopts the response surface analysis test method to determine the welding parameters, and examined the macroscopic morphology, microstructure, microhardness, and tensile properties of the cross-section of the welded joints. The results revealed that the key factors influencing welded joints quality, in descending order of importance, are distance to focus, welding speed, and single-pass heat input. The interaction between these factors is extremely significant. The weld zone of the joints is primarily composed of lath martensite, while the heat-affected zone is composed of ferrite, martensite, carburite, tempered martensite, and residual austenite. The optimized welding parameters align with actual expectations, yielding an average engineering stress of 616.9 MPa for the joint. Notably, the fracture area shifts from the heat-affected zone of JSC590R to the base material. Full article
(This article belongs to the Special Issue Welding and Joining Technology of Dissimilar Metal Materials)
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21 pages, 5538 KiB  
Article
Investigating the Role of Microclimate and Microorganisms in the Deterioration of Stone Heritage: The Case of Rupestrian Church from Jac, Romania
by Dorina Camelia Ilieș, Andrei-Ionuț Apopei, Cristina Mircea, Alexandru Ilieș, Tudor Caciora, Berdenov Zharas, Lucian Barbu-Tudoran, Nicolaie Hodor, Alexandru Turza, Ana Cornelia Pereș, Thowayeb H. Hassan, Bahodirhon Safarov and Ioan-Cristian Noje
Appl. Sci. 2024, 14(18), 8136; https://doi.org/10.3390/app14188136 - 10 Sep 2024
Cited by 2 | Viewed by 1863
Abstract
Natural stone can undergo disaggregation from various causes, including physical actions such as freeze–thaw cycles, temperature and humidity variations, chemical actions such as the solubilization of minerals by organic and inorganic acids, as well as biological actions due to the colonization of organisms [...] Read more.
Natural stone can undergo disaggregation from various causes, including physical actions such as freeze–thaw cycles, temperature and humidity variations, chemical actions such as the solubilization of minerals by organic and inorganic acids, as well as biological actions due to the colonization of organisms that can produce biocorrosion and biomineralization. This research investigates the impact of microclimatic conditions and microbial activity on the physical and chemical integrity of stone heritage, particularly the biodeterioration caused by fungi in the case of a Romanian rock church. Various analytical techniques were employed, including macroscopic and optical microscopy, Raman spectroscopy, X-ray diffraction, and culture-based identification methods, to characterize the mineral composition and microbial contamination of the rock samples. The analyses revealed that the sandstone consists primarily of quartz (over 90%), muscovite (5–10%), and feldspars. The identified fungi included Cladosporium herbarium, Aspergillus niger, and Mortierella hyalina. The SEM images showed fungal hyphae and spores within the kaolinite–illite matrix, indicating significant microbial colonization and its role in rock deterioration. Additionally, microclimatic data collected over a 12-week period highlighted the substantial fluctuations in temperature and relative humidity within the church, which contribute to the physical and chemical weathering of the stone. This study also noted high levels of particulate matter (PM2.5 and PM10) and volatile organic compounds, which can exacerbate microbial growth and stone decay. The comprehensive analysis underscores the need for targeted preservation strategies that consider both microclimatic factors and microbial colonization to effectively conserve stone heritage sites, ensuring their longevity and structural integrity. Full article
(This article belongs to the Special Issue Advanced Study on Diagnostics for Surfaces of Historical Buildings)
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15 pages, 984 KiB  
Article
Rapid Access to Empirical Impact Ionization Cross Sections for Atoms and Ions across the Periodic Table
by Stephan Fritzsche, Liguang Jiao and Giorgio Visentin
Plasma 2024, 7(1), 106-120; https://doi.org/10.3390/plasma7010008 - 30 Jan 2024
Cited by 3 | Viewed by 2952
Abstract
Electron-impact ionization (EII) processes are essential for modelling high-temperature plasma in quite different research areas, from astrophysics to material science to plasma and fusion research and in several places elsewhere. In most, if not all, of these fields, partial and total EII cross [...] Read more.
Electron-impact ionization (EII) processes are essential for modelling high-temperature plasma in quite different research areas, from astrophysics to material science to plasma and fusion research and in several places elsewhere. In most, if not all, of these fields, partial and total EII cross sections are required, and often for a good range of electron energies, in order to determine, for instance, the level population of ions and spectral line intensities in plasma under both local and non-local thermodynamic equilibrium conditions. To obey these needs, various kinds of semi-empirical EII cross sections have been applied in practice, often simply because of the large computational demands in dealing explicitly with two free electrons within the continuum. Here, we expand Jac, the Jena Atomic Calculator, to provide such empirical EII cross sections for (most) atoms and ions across the periodic table. Five empirical models from the recent literature have been implemented to support a simple and rapid access to the partial EII cross sections for electrons from a (partly filled) shell (n)q as well as the total ionization cross sections. We here restrict ourselves to the direct part of the EII cross section, whereas the impact excitation of electrons with subsequent autoionization and the resonant electron capture with double autoionization have been left aside in this first implementation. Rapid access to the (direct) EII cross sections will help already to better understand the role of electron-impact processes in the diagnostics of fusion plasma or the interpretation of astrophysical spectra. Full article
(This article belongs to the Special Issue Feature Papers in Plasma Sciences 2023)
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12 pages, 2546 KiB  
Article
Production of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from CO2 via pH-Stat Jar Cultivation of an Engineered Hydrogen-Oxidizing Bacterium Cupriavidus necator
by Kenji Tanaka, Izumi Orita and Toshiaki Fukui
Bioengineering 2023, 10(11), 1304; https://doi.org/10.3390/bioengineering10111304 - 10 Nov 2023
Cited by 7 | Viewed by 2567
Abstract
The copolyester of 3-hydroxybutyrate (3HB) and 3-hydoxyhexanoate (3HHx), PHBHHx, is a biodegradable plastic characterized by high flexibility, softness, a wide process window, and marine biodegradability. PHBHHx is usually produced from structurally related carbon sources, such as vegetable oils or fatty acids, but not [...] Read more.
The copolyester of 3-hydroxybutyrate (3HB) and 3-hydoxyhexanoate (3HHx), PHBHHx, is a biodegradable plastic characterized by high flexibility, softness, a wide process window, and marine biodegradability. PHBHHx is usually produced from structurally related carbon sources, such as vegetable oils or fatty acids, but not from inexpensive carbon sources such as sugars. In previous studies, we demonstrated that engineered strains of a hydrogen-oxidizing bacterium, Cupriavidus necator, synthesized PHBHHx with a high cellular content not only from sugars but also from CO2 as the sole carbon source in the flask culture. In this study, the highly efficient production of PHBHHx from CO2 was investigated via pH-stat jar cultivation of recombinant C. necator strains while feeding the substrate gas mixture (H2/O2/CO2 = 80:10:10 v/v%) to a complete mineral medium in a recycled-gas, closed-circuit culture system. As a result, the dry cell mass and PHBHHx concentration with the strain MF01/pBPP-ccrMeJAc-emd reached up to 59.62 ± 3.18 g·L−1 and 49.31 ± 3.14 g·L−1, respectively, after 216 h of jar cultivation with limited addition of ammonia and phosphate solutions. The 3HHx composition was close to 10 mol%, which is suitable for practical applications. It is expected that the autotrophic cultivation of the recombinant C. necator can be feasible for the mass production of PHBHHx from CO2. Full article
(This article belongs to the Special Issue Advances in Polyhydroxyalkanoate (PHA) Production, 4th Edition)
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17 pages, 12441 KiB  
Article
JAC4 Alleviates Rotenone-Induced Parkinson’s Disease through the Inactivation of the NLRP3 Signal Pathway
by Lu Zou, Zhen Che, Kun Ding, Chao Zhang, Xia Liu, Luman Wang, Aiping Li and Jianwei Zhou
Antioxidants 2023, 12(5), 1134; https://doi.org/10.3390/antiox12051134 - 20 May 2023
Cited by 11 | Viewed by 3149
Abstract
Parkinson’s disease (PD) is the fastest-growing neurodegeneration disease, characterized typically by a progressive loss of dopaminergic neurons in the substantia nigra, and there are no effective therapeutic agents to cure PD. Rotenone (Rot) is a common and widely used pesticide which can directly [...] Read more.
Parkinson’s disease (PD) is the fastest-growing neurodegeneration disease, characterized typically by a progressive loss of dopaminergic neurons in the substantia nigra, and there are no effective therapeutic agents to cure PD. Rotenone (Rot) is a common and widely used pesticide which can directly inhibit mitochondrial complex I, leading to a loss of dopaminergic neurons. Our previous studies proved that the JWA gene (arl6ip5) may play a prominent role in resisting aging, oxidative stress and inflammation, and JWA knockout in astrocytes increases the susceptibility of mice to 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD. JWA-activating compound 4 (JAC4) is a small-molecule activator of the JWA gene, but its role in and mechanism against PD have not yet been clarified. In the present study, we showed that the JWA expression level is strongly related to tyrosine hydroxylase (TH) in different growth periods of mice. Additionally, we constructed models with Rot in vivo and in vitro to observe the neuroprotective effects of JAC4. Our results demonstrated that JAC4 prophylactic intervention improved motor dysfunction and dopaminergic neuron loss in mice. Mechanistically, JAC4 reduced oxidative stress damage by reversing mitochondrial complex I damage, reducing nuclear factor kappa-B (NF-κB) translocation and repressing nucleotide-binding domain, leucine-rich-containing family and pyrin domain-containing-3 (NLRP3) inflammasome activation. Overall, our results provide proof that JAC4 could serve as a novel effective agent for PD prevention. Full article
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27 pages, 19713 KiB  
Article
JAC4 Inhibits EGFR-Driven Lung Adenocarcinoma Growth and Metastasis through CTBP1-Mediated JWA/AMPK/NEDD4L/EGFR Axis
by Kun Ding, Xuqian Jiang, Zhangding Wang, Lu Zou, Jiahua Cui, Xiong Li, Chuanjun Shu, Aiping Li and Jianwei Zhou
Int. J. Mol. Sci. 2023, 24(10), 8794; https://doi.org/10.3390/ijms24108794 - 15 May 2023
Cited by 5 | Viewed by 2797
Abstract
Lung adenocarcinoma (LUAD) is the most common lung cancer, with high mortality. As a tumor-suppressor gene, JWA plays an important role in blocking pan-tumor progression. JAC4, a small molecular-compound agonist, transcriptionally activates JWA expression both in vivo and in vitro. However, the direct [...] Read more.
Lung adenocarcinoma (LUAD) is the most common lung cancer, with high mortality. As a tumor-suppressor gene, JWA plays an important role in blocking pan-tumor progression. JAC4, a small molecular-compound agonist, transcriptionally activates JWA expression both in vivo and in vitro. However, the direct target and the anticancer mechanism of JAC4 in LUAD have not been elucidated. Public transcriptome and proteome data sets were used to analyze the relationship between JWA expression and patient survival in LUAD. The anticancer activities of JAC4 were determined through in vitro and in vivo assays. The molecular mechanism of JAC4 was assessed by Western blot, quantitative real-time PCR (qRT-PCR), immunofluorescence (IF), ubiquitination assay, co-immunoprecipitation, and mass spectrometry (MS). Cellular thermal shift and molecule-docking assays were used for confirmation of the interactions between JAC4/CTBP1 and AMPK/NEDD4L. JWA was downregulated in LUAD tissues. Higher expression of JWA was associated with a better prognosis of LUAD. JAC4 inhibited LUAD cell proliferation and migration in both in-vitro and in-vivo models. Mechanistically, JAC4 increased the stability of NEDD4L through AMPK-mediated phosphorylation at Thr367. The WW domain of NEDD4L, an E3 ubiquitin ligase, interacted with EGFR, thus promoting ubiquitination at K716 and the subsequent degradation of EGFR. Importantly, the combination of JAC4 and AZD9191 synergistically inhibited the growth and metastasis of EGFR-mutant lung cancer in both subcutaneous and orthotopic NSCLC xenografts. Furthermore, direct binding of JAC4 to CTBP1 blocked nuclear translocation of CTBP1 and then removed its transcriptional suppression on the JWA gene. The small-molecule JWA agonist JAC4 plays a therapeutic role in EGFR-driven LUAD growth and metastasis through the CTBP1-mediated JWA/AMPK/NEDD4L/EGFR axis. Full article
(This article belongs to the Section Molecular Oncology)
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15 pages, 736 KiB  
Article
Collision Strengths of Astrophysical Interest for Multiply Charged Ions
by Stephan Fritzsche, Li-Guang Jiao, Yuan-Cheng Wang and Jozef E. Sienkiewicz
Atoms 2023, 11(5), 80; https://doi.org/10.3390/atoms11050080 - 6 May 2023
Cited by 9 | Viewed by 2367
Abstract
The electron impact excitation and ionization processes are crucial for modeling the spectra of different astrophysical objects, from atmospheres of late-type stars to remnants of supernovae and up to the light emission from neutron star mergers, to name just a few. Despite their [...] Read more.
The electron impact excitation and ionization processes are crucial for modeling the spectra of different astrophysical objects, from atmospheres of late-type stars to remnants of supernovae and up to the light emission from neutron star mergers, to name just a few. Despite their significance, however, little is known quantitatively about these processes for low- and medium-impact energies of, say, Ekin5000 eV of the free incident electron. To further explore the role of impact excitation, we here expanded Jac, the Jena Atomic Calculator, to the computation of distorted wave collision strengths for fine-structure-resolved, as well as configuration-averaged transitions. While we excluded the formation of dielectronic resonances, these tools can be readily applied for ions with a complex shell structure and by including the major relativistic contributions to these strengths. Detailed computations of the collision strengths are shown and explained for the impact excitation of lithium- and chlorine-like ions. When compared with other, well-correlated methods, good agreement was found, and hence, these tools will support studies of effective collision strengths for a wide range of electron impact energies, levels, and ionic charge states. Full article
(This article belongs to the Special Issue Atomic Processes for Plasma Modeling Applications)
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15 pages, 1524 KiB  
Article
Radiative Recombination Plasma Rate Coefficients for Multiply Charged Ions
by Stephan Fritzsche, Anna V. Maiorova and Zhongwen Wu
Atoms 2023, 11(3), 50; https://doi.org/10.3390/atoms11030050 - 4 Mar 2023
Cited by 6 | Viewed by 2474
Abstract
Radiative recombination (RR) plasma rate coefficients are often applied to estimate electron densities and temperatures under quite different plasma conditions. Despite their frequent use, however, these rate coefficients are available only for selected (few-electron) ions and isoelectronic sequences, mainly because of the computational [...] Read more.
Radiative recombination (RR) plasma rate coefficients are often applied to estimate electron densities and temperatures under quite different plasma conditions. Despite their frequent use, however, these rate coefficients are available only for selected (few-electron) ions and isoelectronic sequences, mainly because of the computational efforts required. To overcome this limitation, we report here a (relativistic) cascade model which helps compute fine-structure and shell-resolved as well as total RR plasma rate coefficients for many, if not most, elements of the periodic table. This model is based on Jac, the Jena Atomic Calculator, and supports studies on how the electron is captured in selected levels of the recombined ion, a relativistic (Maxwellian) electron distribution, or how the multipoles beyond the electric-dipole field in the electron-photon interaction affect the RR rate coefficients and, hence, the ionization and recombination dynamics of hot plasma. As a demonstration of this model, we compute, compare, and discuss different RR plasma rate coefficients for initially helium-like ions, with an emphasis especially on Fe24+ ions. Full article
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23 pages, 4474 KiB  
Article
FKF1 Interacts with CHUP1 and Regulates Chloroplast Movement in Arabidopsis
by Ning Yuan, Lavanya Mendu, Kaushik Ghose, Carlie Shea Witte, Julia Frugoli and Venugopal Mendu
Plants 2023, 12(3), 542; https://doi.org/10.3390/plants12030542 - 25 Jan 2023
Cited by 3 | Viewed by 3737
Abstract
Plants have mechanisms to relocate chloroplasts based on light intensities in order to maximize photosynthesis and reduce photodamage. Under low light, chloroplasts move to the periclinal walls to increase photosynthesis (accumulation) and move to the anticlinal walls under high light to avoid photodamage, [...] Read more.
Plants have mechanisms to relocate chloroplasts based on light intensities in order to maximize photosynthesis and reduce photodamage. Under low light, chloroplasts move to the periclinal walls to increase photosynthesis (accumulation) and move to the anticlinal walls under high light to avoid photodamage, and even cell death (avoidance). Arabidopsis blue light receptors phot1 and phot2 (phototropins) have been reported to regulate chloroplast movement. This study discovered that another blue light receptor, FLAVIN-BINDING KELCH REPEAT F-BOX1 (FKF1), regulates chloroplast photorelocation by physically interacting with chloroplast unusual positioning protein 1 (CHUP1), a critical component of the chloroplast motility system. Leaf cross-sectioning and red-light transmittance results showed that overexpression of FKF1 compromised the avoidance response, while the absence of FKF1 enhanced chloroplast movements under high light. Western blot analysis showed that CHUP1 protein abundance is altered in FKF1 mutants and overexpression lines, indicating a potential regulation of CHUP1 by FKF1. qPCR results showed that two photorelocation pathway genes, JAC1 and THRUMIN1, were upregulated in FKF1-OE lines, and overexpression of FKF1 in the THRUMIN1 mutant weakened its accumulation and avoidance responses, indicating that JAC1 and THRUMIN1 may play a role in the FKF1-mediated chloroplast avoidance response. However, the precise functional roles of JAC1 and THRUMIN1 in this process are not known. Full article
(This article belongs to the Special Issue Molecular Biology of Chloroplast: Structure, Function and Development)
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20 pages, 2365 KiB  
Article
Lectin-Based Affinity Enrichment and Characterization of N-Glycoproteins from Human Tear Film by Mass Spectrometry
by Carsten Schmelter, Alina Brueck, Natarajan Perumal, Sichang Qu, Norbert Pfeiffer and Franz H. Grus
Molecules 2023, 28(2), 648; https://doi.org/10.3390/molecules28020648 - 8 Jan 2023
Cited by 7 | Viewed by 4033
Abstract
The glycosylation of proteins is one of the most common post-translational modifications (PTMs) and plays important regulatory functions in diverse biological processes such as protein stability or cell signaling. Accordingly, glycoproteins are also a consistent part of the human tear film proteome, maintaining [...] Read more.
The glycosylation of proteins is one of the most common post-translational modifications (PTMs) and plays important regulatory functions in diverse biological processes such as protein stability or cell signaling. Accordingly, glycoproteins are also a consistent part of the human tear film proteome, maintaining the proper function of the ocular surface and forming the first defense barrier of the ocular immune system. Irregularities in the glycoproteomic composition of tear film might promote the development of chronic eye diseases, indicating glycoproteins as a valuable source for biomarker discovery or drug target identification. Therefore, the present study aimed to develop a lectin-based affinity method for the enrichment and concentration of tear glycoproteins/glycopeptides and to characterize their specific N-glycosylation sites by high-resolution mass spectrometry (MS). For method development and evaluation, we first accumulated native glycoproteins from human tear sample pools and assessed the enrichment efficiency of different lectin column systems by 1D gel electrophoresis and specific protein stainings (Coomassie and glycoproteins). The best-performing multi-lectin column system (comprising the four lectins ConA, JAC, WGA, and UEA I, termed 4L) was applied to glycopeptide enrichment from human tear sample digests, followed by MS-based detection and localization of their specific N-glycosylation sites. As the main result, our study identified a total of 26 N glycosylation sites of 11 N-glycoproteins in the tear sample pools of healthy individuals (n = 3 biological sample pools). Amongst others, we identified tear film proteins lactotransferrin (N497 and N642, LTF), Ig heavy chain constant α-1 (N144 and 340, IGHA1), prolactin-inducible protein (N105, PIP), and extracellular lacritin (N105, LACRT) as highly reliable and significant N glycoproteins, already associated with the pathogenesis of various chronic eye diseases such as dry eye syndrome (DES). In conclusion, the results of the present study will serve as an important tear film N-glycoprotein catalog for future studies focusing on human tear film and ocular surface-related inflammatory diseases. Full article
(This article belongs to the Special Issue Frontiers in Mass Spectrometry Based Glycomics and Glycoproteomics)
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18 pages, 2776 KiB  
Article
Pathogen Resistance Depending on Jacalin-Dirigent Chimeric Proteins Is Common among Poaceae but Absent in the Dicot Arabidopsis as Evidenced by Analysis of Homologous Single-Domain Proteins
by Lara Esch, Christian Kirsch, Lara Vogel, Jana Kelm, Nikolai Huwa, Maike Schmitz, Thomas Classen and Ulrich Schaffrath
Plants 2023, 12(1), 67; https://doi.org/10.3390/plants12010067 - 23 Dec 2022
Cited by 2 | Viewed by 2505
Abstract
MonocotJRLs are Poaceae-specific two-domain proteins that consist of a jacalin-related lectin (JRL) and a dirigent (DIR) domain which participate in multiple developmental processes, including disease resistance. For OsJAC1, a monocotJRL from rice, it has been confirmed that constitutive expression in transgenic rice [...] Read more.
MonocotJRLs are Poaceae-specific two-domain proteins that consist of a jacalin-related lectin (JRL) and a dirigent (DIR) domain which participate in multiple developmental processes, including disease resistance. For OsJAC1, a monocotJRL from rice, it has been confirmed that constitutive expression in transgenic rice or barley plants facilitates broad-spectrum disease resistance. In this process, both domains of OsJAC1 act cooperatively, as evidenced from experiments with artificially separated JRL- or DIR-domain-containing proteins. Interestingly, these chimeric proteins did not evolve in dicotyledonous plants. Instead, proteins with a single JRL domain, multiple JRL domains or JRL domains fused to domains other than DIR domains are present. In this study, we wanted to test if the cooperative function of JRL and DIR proteins leading to pathogen resistance was conserved in the dicotyledonous plant Arabidopsis thaliana. In Arabidopsis, we identified 50 JRL and 24 DIR proteins, respectively, from which seven single-domain JRL and two single-domain DIR candidates were selected. A single-cell transient gene expression assay in barley revealed that specific combinations of the Arabidopsis JRL and DIR candidates reduced the penetration success of barley powdery mildew. Strikingly, one of these pairs, AtJAX1 and AtDIR19, is encoded by genes located next to each other on chromosome one. However, when using natural variation and analyzing Arabidopsis ecotypes that express full-length or truncated versions of AtJAX1, the presence/absence of the full-length AtJAX1 protein could not be correlated with resistance to the powdery mildew fungus Golovinomyces orontii. Furthermore, an analysis of the additional JRL and DIR candidates in a bi-fluorescence complementation assay in Nicotiana benthamiana revealed no direct interaction of these JRL/DIR pairs. Since transgenic Arabidopsis plants expressing OsJAC1-GFP also did not show increased resistance to G. orontii, it was concluded that the resistance mediated by the synergistic activities of DIR and JRL proteins is specific for members of the Poaceae, at least regarding the resistance against powdery mildew. Arabidopsis lacks the essential components of the DIR-JRL-dependent resistance pathway. Full article
(This article belongs to the Collection Feature Papers in Plant Protection)
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