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Plants (Basel, Switzerland) Jun 2024This study focuses on optimizing chlorophyll extraction techniques, in which leaf discs are cut from places on the leaf blade to enhance chlorophyll concentration in...
This study focuses on optimizing chlorophyll extraction techniques, in which leaf discs are cut from places on the leaf blade to enhance chlorophyll concentration in sesame ( L.) leaves. Thirty sesame genotypes, categorized into light green (LG), middle green (MG), and deep green (DG) pigment groups based on leaf coloration, were selected from a larger pool of field-grown accessions. The investigation involved determining optimal Soil Plant Analysis Development (SPAD) value index measurements, quantifying pigment concentrations, exploring extraction solvents, and selecting suitable leaf disk positions. Significant variations in chlorophyll content were observed across genotypes, greenness categories, and leaf disk positions. The categorization of genotypes into DG, MG, and LG groups revealed a correlation between leaf appearance and chlorophyll content. The study highlighted a consistent relationship between carotenoids and chlorophyll, indicating their role in adaptation to warm environments. An examination of leaf disk positions revealed a significant chlorophyll gradient along the leaf blade, emphasizing the need for standardized protocols. Chlorophyll extraction experiments identified DMSO and 96% ethanol, particularly in those incubated for 10 min at 85 °C, as effective choices. This recommendation considers factors like cost-effectiveness, time efficiency, safety, and environmental regulations, ensuring consistent and simplified extraction processes. For higher chlorophyll extraction, focusing on leaf tips and the 75% localization along the sesame leaf blade is suggested, as this consistently yields increased chlorophyll content. Furthermore, our examination revealed significant anatomical variations in the internal structure of the mesophyll tissue leaves between deep green and light green sesame plants, primarily linked to chloroplast density and pigment-producing structures. Our findings, therefore, provide insightful knowledge of chlorophyll gradients and encourage the use of standardized protocols that enable researchers to refine their experimental designs for precise and comparable chlorophyll measurements. The recommended solvent choices ensure reliable outcomes in plant physiology, ecology, and environmental studies.
PubMed: 38931021
DOI: 10.3390/plants13121589 -
Materials (Basel, Switzerland) Jun 2024The article discusses the phenomena and destructive mechanisms occurring on the surface of 1.2344 steel dies used during the hot forging of disc-type forgings....
Increasing the Working Time of Forging Tools Used in the Industrial Process of Producing a Disk-Type Forging Assigned for a Gearbox through the Application of Hybrid Layers.
The article discusses the phenomena and destructive mechanisms occurring on the surface of 1.2344 steel dies used during the hot forging of disc-type forgings. Preliminary research has shown that gas nitriding alone, used so far, is insufficient due to the occurrence of destructive mechanisms other than abrasive wear, such as thermal and thermomechanical fatigue, which cause the average durability of such tools to be approximately 5000 forgings. Analyses were also carried out to assess the load on forging tools using numerical modeling (Forge 3.0NxT), which confirmed the occurrence of large and cyclically changing thermal and mechanical loads during the forging process. Therefore, in order to increase operational durability, it was decided to use two types of hybrid layers, differing in the PVD coating used: TiCrAlN and CrN, and then subjected to gas nitriding (GN). The obtained results showed that, depending on the area of the tool and the current working conditions, the applied PVD coatings protect the surface layer of the tool against the dominant destructive mechanisms. In both cases, the strength increased to the level of 7000 forgings, the tools could continue to work, and globally, slightly better results were obtained for the GN+TiCrAlN layer. The CrN-type layer protects the tool more against thermal fatigue, while the TiCrAlN layer is more resistant to abrasive wear. In areas where the hybrid layer was worn, a decrease in hardness was observed from 1300 HV to 600-700 HV, and in places of intense material flow (front-point 2 and tool bridge-point 9) the hardness dropped to below 400 HV, which may indicate local tempering of the material. Moreover, the research has shown that each process and tool should be analyzed individually, and the areas in the tool where particular destructive mechanisms dominate should be identified, so as to further protect the forging tool by using appropriate protective coatings in these areas.
PubMed: 38930374
DOI: 10.3390/ma17123005 -
Materials (Basel, Switzerland) Jun 2024In this study, the ball-on-disk sliding wear and tribocorrosion behavior in the HSO and HCl solution of NiCoCrMoCu alloys with carbon additions of 0.2, 1, 1.5, and 2...
In this study, the ball-on-disk sliding wear and tribocorrosion behavior in the HSO and HCl solution of NiCoCrMoCu alloys with carbon additions of 0.2, 1, 1.5, and 2 wt.% with the AlO ball as a counterpart was investigated systematically. Obvious tribocorrosion antagonistic effects were found after wear in both aqueous solutions. Compared with dry sliding wear conditions, the lubrication effect of the aqueous solution significantly reduces the wear rate of the alloy, and the reduction effect in the HSO aqueous solution was more obvious than that in HCl. The antagonistic effects of the 0.2C and 1C alloys decrease with the load and sliding rate, while those of the 1.5C and 2C alloys increase. The (coefficient of friction) COF and wear rate under different loads and sliding rates were analyzed using the response surface analysis (RSM) method. It was found that the COF mainly showed dependence on the sliding rate, while the wear rate showed dependence on load and sliding speed.
PubMed: 38930340
DOI: 10.3390/ma17122971 -
Journal of Clinical Medicine Jun 2024: Lumbar disc herniation, a complex challenge in spinal health, significantly impacts individuals across diverse age groups. This article delves into the intricacies of...
: Lumbar disc herniation, a complex challenge in spinal health, significantly impacts individuals across diverse age groups. This article delves into the intricacies of this condition, emphasising the pivotal role of anatomical considerations in its understanding and management. Additionally, lumbar discectomy might be considered an "easy" surgery; nevertheless, it carries significant risks. The aim of the study was to present a groundbreaking "three-step approach" with some anatomical insight derived from our comprehensive clinical experiences, designed to systematise the surgical approach and optimise the outcomes, especially for young spine surgeons. We highlighted the purpose of the study and introduced our research question(s) and the context surrounding them. : This retrospective study involved patients treated for lumbar disc herniation at a single institution. The patient demographics, surgical details, and postoperative assessments were meticulously recorded. All surgeries were performed by a consistent surgical team. : A total of 847 patients of the 998 patients initially included completed the follow-up period. A three-step approach was performed for every patient. The recurrence rate was 1.89%. Furthermore, the incidence of lumbar instability and the need for reoperation were carefully examined, presenting a holistic view of the outcomes. : The three-step approach emerged as a robust and effective strategy for addressing lumbar disc herniation. This structured approach ensures a safe and educational experience for young spinal surgeons.
PubMed: 38930100
DOI: 10.3390/jcm13123571 -
Journal of Clinical Medicine Jun 2024: Standard oblique cages cannot cover endplates side-to-side, which is an important biomechanical factor for reducing the risk of cage subsidence and for restoring...
New Axially Expandable Oblique Cage Designed for Anterior to Psoas (ATP) Approach: Indications-Surgical Technique and Clinical-Radiological Outcomes in Patients with Symptomatic Degenerative Disc Disease.
: Standard oblique cages cannot cover endplates side-to-side, which is an important biomechanical factor for reducing the risk of cage subsidence and for restoring correct segmental lordosis. The aim of this study is to evaluate the radiological and clinical results of a new oblique lumbar interbody fusion (OLIF) axially expandable cage. : This is a prospective observational case-control study. From March 2018 to June 2020, 28 consecutive patients with lumbar degenerative disease underwent an ATP approach, with the insertion of a new axially expandable cage, which was used as a stand-alone procedure or followed by posterior percutaneous pedicle fixation. : Twenty-eight patients in both groups met the inclusion criteria. The mean follow-up time was 31.2 months (range of 13-37). The clinical results were not significantly different, although in the control group, two major intraoperative complications were recorded, and slight improvements in ODI and SF-36 scores were observed in the study group. The radiological results showed a less frequent incidence of subsidence and a higher rate of fusion in the study group compared to controls. : The axially expandable oblique cage for lumbar inter body fusion, specifically designed for the ATP approach, represents an innovation and a technical improvement. The insertion and the axial expansion technique are safe and easy. The large footprint could obtain solid and effective arthrodesis, potentially reducing the risk of subsidence.
PubMed: 38929973
DOI: 10.3390/jcm13123444 -
Antibiotics (Basel, Switzerland) Jun 2024With the increasing burden of carbapenem-resistant (CR-Kp), including high rates of healthcare-associated infections, treatment failure, and mortality, a good...
UNLABELLED
With the increasing burden of carbapenem-resistant (CR-Kp), including high rates of healthcare-associated infections, treatment failure, and mortality, a good therapeutic strategy for attacking this multi-resistant pathogen is one of the main goals in current medical practice and necessitates the use of novel antibiotics or new drug combinations.
OBJECTIVES
We reviewed the clinical and microbiological outcomes of seven patients treated at the "Agrippa Ionescu" Clinical Emergency Hospital between October 2023 and January 2024, aiming to demonstrate the synergistic activity of the ceftazidime-avibactam (C/A) plus aztreonam (ATM) combination against the co-producers of NDM + OXA-48-like CR-Kp.
MATERIAL AND METHODS
Seven CR-Kp with NDM and OXA-48 as resistance mechanisms were tested. Seven patients treated with C/A + ATM were included. The synergistic activity of C/A + ATM was proven through double-disk diffusion in all seven isolates. Resistance mechanisms like KPC, VIM, OXA-48, NDM, IMP, and CTX-M were assessed through immunochromatography.
RESULTS
With a mean of nine days of treatment with the synergistic combination C/A + ATM, all patients achieved clinical recovery, and five achieved microbiological recovery.
CONCLUSIONS
With the emerging co-occurrence of OXA-48 and NDM among in Romania, the combination of C/A and ATM could be a promising therapeutic option.
PubMed: 38927216
DOI: 10.3390/antibiotics13060550 -
Antibiotics (Basel, Switzerland) Jun 2024Dental caries is a global health problem that requires better prevention measures. One of the goals is to reduce the prevalence of the cariogenic Gram-positive bacterium...
Dental caries is a global health problem that requires better prevention measures. One of the goals is to reduce the prevalence of the cariogenic Gram-positive bacterium . We have recently shown that naturally occurring arachidonic acid (AA) has both anti-bacterial and anti-biofilm activities against this bacterium. An important question is how these activities are affected by other anti-bacterial compounds commonly used in mouthwashes. Here, we studied the combined treatment of AA with chlorhexidine (CHX), cetylpyridinium chloride (CPC), triclosan, and fluoride. Checkerboard microtiter assays were performed to determine the effects on bacterial growth and viability. Biofilms were quantified using the MTT metabolic assay, crystal violet (CV) staining, and live/dead staining with SYTO 9/propidium iodide (PI) visualized by spinning disk confocal microscopy (SDCM). The bacterial morphology and the topography of the biofilms were visualized by high-resolution scanning electron microscopy (HR-SEM). The effect of selected drug combinations on cell viability and membrane potential was investigated by flow cytometry using SYTO 9/PI staining and the potentiometric dye DiOC2(3), respectively. We found that CHX and CPC had an antagonistic effect on AA at certain concentrations, while an additive effect was observed with triclosan and fluoride. This prompted us to investigate the triple treatment of AA, triclosan, and fluoride, which was more effective than either compound alone or the double treatment. We observed an increase in the percentage of PI-positive bacteria, indicating increased bacterial cell death. Only AA caused significant membrane hyperpolarization, which was not significantly enhanced by either triclosan or fluoride. In conclusion, our data suggest that AA can be used together with triclosan and fluoride to improve the efficacy of oral health care.
PubMed: 38927206
DOI: 10.3390/antibiotics13060540 -
Brazilian Journal of Microbiology :... Jun 2024Pseudomonas aeruginosa is one of the most important nosocomial pathogens that possess the ability to produce multiple antibiotic resistance and virulence factors....
Effect of phenylalanine arginyl β-naphthylamide on the imipenem resistance, elastase production, and the expression of quorum sensing and virulence factor genes in Pseudomonas aeruginosa clinical isolates.
Pseudomonas aeruginosa is one of the most important nosocomial pathogens that possess the ability to produce multiple antibiotic resistance and virulence factors. Elastase B (LasB) is the major factor implicated in tissue invasion and damage during P. aeruginosa infections, whose synthesis is regulated by the quorum sensing (QS) system. Anti-virulence approach is now considered as potential therapeutic alternative and/or adjuvant to current antibiotics' failure. The aim of this study is primarily to find out the impact of the efflux pump inhibitor (EPI) phenylalanine arginyl β-naphthylamide (PAβN) on the production of elastase B and the gene expression of lasI quorum sensing and lasB virulence factor in clinical isolates of P. aeruginosa. Five P. aeruginosa isolates recovered from patients with respiratory tract infections were examined in this study. Antimicrobial susceptibility of isolates was performed by the disk agar diffusion method. Effect of the PAβN on imipenem susceptibility, bacterial viability, and elastase production was evaluated. The expression of lasB and lasI genes was measured by quantitative real-time PCR in the presence of PAβN. All isolates were identified as multidrug-resistant (MDR) and showed resistance to carbapenem (MIC = 64-256 µg/mL). Susceptibility of isolates to imipenem was highly increased in the presence of efflux inhibitor. PAβN significantly reduced elastase activity in three isolates tested without affecting bacterial growth. In addition, the relative expression of both lasB and lasI genes was diminished in all isolates in the presence of inhibitor. Efflux inhibition by using the EPI PAβN could be a potential target for controlling the P. aeruginosa virulence and pathogenesis. Furthermore, impairment of drug efflux by PAβN indicates its capability to be used as antimicrobial adjuvant that can decrease the resistance and lower the effective doses of current drugs.
PubMed: 38926315
DOI: 10.1007/s42770-024-01426-7 -
International Ophthalmology Jun 2024The aim of this study was to evaluate the lamina cribrosa curvature index in different types of glaucoma in comparison with clinical findings and conventional...
OBJECTIVE
The aim of this study was to evaluate the lamina cribrosa curvature index in different types of glaucoma in comparison with clinical findings and conventional measurement methods.
MATERIAL AND METHOD
Patients older than 18 years who were followed up in Glaucoma Unit of Department of Ophthalmology at Fırat University Faculty of Medicine, whose disease had been under control at least for 1 year, who had at least three reliable visual fields, whose refractive error was between - 6 and + 5 diopter and who did not have any disease other than glaucoma that would affect the visual field, were included in the study. Clinical and demographic characteristics, visual field, optical coherence tomography and lamina cribrosa curvature index (LCCI) results were evaluated. The study patients were divided into six groups: early-stage primary open-angle glaucoma (POAG) as group 1 and intermediate-advanced stage POAG as group 2, pseudo-exfoliation glaucoma (PEXG) as group 3, normal tension glaucoma (NTG) as group 4, ocular hypertension patients whom subsequently developed POAG as group 5 and healthy control as group 6.
RESULTS
A total of 189 eyes of 101 patients were included in our study. Forty-seven patients were male (46.5%) and 54 were female (53.5%). The mean age was 62.43 ± 1.49 years. LCCI, mean deviation (MD), visual field index (VFI), pattern standard deviation (PSD) and retinal nerve fiber layer thickness (RNFL) values were analyzed in all groups and Pearson correlation analysis showed statistically significant correlation between PSD and RNFL measurements with LCCI values in all groups. MD value was correlated with LCCI in groups 2, 3 and 4, while VFI value was correlated with LCCI in all groups except group 5. When the groups were compared with each other according to the Post-Hoc Tamhane test, LCCI measurement showed statistically significant results in accordance with MD, VFI, PSD and RNFL values.
CONCLUSION
The LCCI assessment is mostly consistent with conventional tests. In this study, in which different types of glaucoma and healthy subjects were examined simultaneously, LCCI shows promise as a detailed and reliable assessment method.
Topics: Humans; Male; Female; Tomography, Optical Coherence; Middle Aged; Visual Fields; Optic Disk; Intraocular Pressure; Aged; Glaucoma, Open-Angle; Retinal Ganglion Cells; Nerve Fibers; Adult; Follow-Up Studies; Glaucoma
PubMed: 38926206
DOI: 10.1007/s10792-024-03190-x -
Science Advances Jun 2024Mechanical computing encodes information in deformed states of mechanical systems, such as multistable structures. However, achieving stable mechanical memory in most...
Mechanical computing encodes information in deformed states of mechanical systems, such as multistable structures. However, achieving stable mechanical memory in most multistable systems remains challenging and often limited to binary information. Here, we report leveraging coupling kinematic bifurcation in rigid cube-based mechanisms with elasticity to create transformable, multistable mechanical computing metastructures with stable, high-density mechanical memory. Simply stretching the planar metastructure forms a multistable corrugated platform. It allows for independent mechanical or magnetic actuation of individual bistable element, serving as pop-up voxels for display or binary units for various tasks such as information writing, erasing, reading, encryption, and mechanologic computing. Releasing the pre-stretched strain stabilizes the prescribed information, resistant to external mechanical or magnetic perturbations, whereas re-stretching enables editable mechanical memory, akin to selective zones or disk formatting for information erasure and rewriting. Moreover, the platform can be reprogrammed and transformed into a multilayer configuration to achieve high-density memory.
PubMed: 38924402
DOI: 10.1126/sciadv.ado6476