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1.
Immunity ; 55(12): 2336-2351.e12, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36462502

RESUMO

Therapeutic promotion of intestinal regeneration holds great promise, but defining the cellular mechanisms that influence tissue regeneration remains an unmet challenge. To gain insight into the process of mucosal healing, we longitudinally examined the immune cell composition during intestinal damage and regeneration. B cells were the dominant cell type in the healing colon, and single-cell RNA sequencing (scRNA-seq) revealed expansion of an IFN-induced B cell subset during experimental mucosal healing that predominantly located in damaged areas and associated with colitis severity. B cell depletion accelerated recovery upon injury, decreased epithelial ulceration, and enhanced gene expression programs associated with tissue remodeling. scRNA-seq from the epithelial and stromal compartments combined with spatial transcriptomics and multiplex immunostaining showed that B cells decreased interactions between stromal and epithelial cells during mucosal healing. Activated B cells disrupted the epithelial-stromal cross talk required for organoid survival. Thus, B cell expansion during injury impairs epithelial-stromal cell interactions required for mucosal healing, with implications for the treatment of IBD.


Assuntos
Colite , Mucosa Intestinal , Animais , Cicatrização , Células Epiteliais/metabolismo , Epitélio , Modelos Animais de Doenças
2.
Proc Natl Acad Sci U S A ; 120(28): e2219825120, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37399379

RESUMO

Compound drought and heatwave (CDHW) events have garnered increased attention due to their significant impacts on agriculture, energy, water resources, and ecosystems. We quantify the projected future shifts in CDHW characteristics (such as frequency, duration, and severity) due to continued anthropogenic warming relative to the baseline recent observed period (1982 to 2019). We combine weekly drought and heatwave information for 26 climate divisions across the globe, employing historical and projected model output from eight Coupled Model Intercomparison Project 6 GCMs and three Shared Socioeconomic Pathways. Statistically significant trends are revealed in the CDHW characteristics for both recent observed and model simulated future period (2020 to 2099). East Africa, North Australia, East North America, Central Asia, Central Europe, and Southeastern South America show the greatest increase in frequency through the late 21st century. The Southern Hemisphere displays a greater projected increase in CDHW occurrence, while the Northern Hemisphere displays a greater increase in CDHW severity. Regional warmings play a significant role in CDHW changes in most regions. These findings have implications for minimizing the impacts of extreme events and developing adaptation and mitigation policies to cope with increased risk on water, energy, and food sectors in critical geographical regions.

3.
J Cell Physiol ; 239(4): e31201, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38284481

RESUMO

Dynamic nuclear architecture and chromatin organizations are the key features of the mid-prophase I in mammalian meiosis. The chromatin undergoes major changes, including meiosis-specific spatiotemporal arrangements and remodeling, the establishment of chromatin loop-axis structure, pairing, and crossing over between homologous chromosomes, any deficiencies in these events may induce genome instability, subsequently leading to failure to produce gametes and infertility. Despite the significance of chromatin structure, little is known about the location of chromatin marks and the necessity of their balance during meiosis prophase I. Here, we show a thorough cytological study of the surface-spread meiotic chromosomes of mouse spermatocytes for H3K9,14,18,23,27,36, H4K12,16 acetylation, and H3K4,9,27,36 methylation. Active acetylation and methylation marks on H3 and H4, such as H3K9ac, H3K14ac, H3K18ac, H3K36ac, H3K56ac, H4K12ac, H4K16ac, and H3K36me3 exhibited pan-nuclear localization away from heterochromatin. In comparison, repressive marks like H3K9me3 and H3K27me3 are localized to heterochromatin. Further, taking advantage of the delivery of small-molecule chemical inhibitors methotrexate (heterochromatin enhancer), heterochromatin inhibitor, anacardic acid (histone acetyltransferase inhibitor), trichostatin A (histone deacetylase inhibitor), IOX1 (JmjC demethylases inhibitor), and AZ505 (methyltransferase inhibitor) in seminiferous tubules through the rete testis route, revealed that alteration in histone modifications enhanced the centromere mislocalization, chromosome breakage, altered meiotic recombination and reduced sperm count. Specifically, IOX1 and AZ505 treatment shows severe meiotic phenotypes, including altering chromosome axis length and chromatin loop size via transcriptional regulation of meiosis-specific genes. Our findings highlight the importance of balanced chromatin modifications in meiotic prophase I chromosome organization and instability.


Assuntos
Histonas , Prófase Meiótica I , Processamento de Proteína Pós-Traducional , Espermatócitos , Animais , Masculino , Camundongos , Cromatina/genética , Heterocromatina , Histonas/metabolismo , Meiose , Espermatócitos/citologia , Espermatócitos/metabolismo
4.
PLoS Pathog ; 18(4): e1010448, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35413079

RESUMO

Banana bunchy top virus (BBTV) is a six-component ssDNA virus (genus Babuvirus, family Nanoviridae) transmitted by aphids, infecting monocots (mainly species in the family Musaceae) and likely originating from South-East Asia where it is frequently associated with self-replicating alphasatellites. Illumina sequencing analysis of banana aphids and leaf samples from Africa revealed an alphasatellite that should be classified in a new genus, phylogenetically related to alphasatellites of nanoviruses infecting dicots. Alphasatellite DNA was encapsidated by BBTV coat protein and accumulated at high levels in plants and aphids, thereby reducing helper virus loads, altering relative abundance (formula) of viral genome components and interfering with virus transmission by aphids. BBTV and alphasatellite clones infected dicot Nicotiana benthamiana, followed by recovery and symptomless persistence of alphasatellite, and BBTV replication protein (Rep), but not alphasatellite Rep, induced leaf chlorosis. Transcriptome sequencing revealed 21, 22 and 24 nucleotide small interfering (si)RNAs covering both strands of the entire viral genome, monodirectional Pol II transcription units of viral mRNAs and pervasive transcription of each component and alphasatellite in both directions, likely generating double-stranded precursors of viral siRNAs. Consistent with the latter hypothesis, viral DNA formulas with and without alphasatellite resembled viral siRNA formulas but not mRNA formulas. Alphasatellite decreased transcription efficiency of DNA-N encoding a putative aphid transmission factor and increased relative siRNA production rates from Rep- and movement protein-encoding components. Alphasatellite itself spawned the most abundant siRNAs and had the lowest mRNA transcription rate. Collectively, following African invasion, BBTV got associated with an alphasatellite likely originating from a dicot plant and interfering with BBTV replication and transmission. Molecular analysis of virus-infected banana plants revealed new features of viral DNA transcription and siRNA biogenesis, both affected by alphasatellite. Costs and benefits of alphasatellite association with helper viruses are discussed.


Assuntos
Afídeos , Babuvirus , Musa , Animais , Afídeos/genética , Babuvirus/genética , DNA Viral/genética , Doenças das Plantas , RNA Interferente Pequeno/genética
5.
Microb Pathog ; 197: 107022, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39419458

RESUMO

Immunosuppression in cancer poses challenges for immunotherapy and highlights the vulnerability of immunocompromised patients to viral infections. This study explored how Chikungunya virus (CHIKV) infection potentially inhibits B16-F10 melanoma-induced immunosuppressive effects on T cells and RAW 264.7 macrophages. We found high expression of CHIKV entry genes in melanoma and other cancers, with B16-F10 cells demonstrating greater susceptibility to CHIKV infection than non-tumorigenic cells. Interestingly, the CHIKV-infected B16-F10 cell culture supernatant (B16-F10-CS) reversed the immunosuppressive effects of uninfected B16-F10-CS on T cells. This reversal was characterised by decreased STAT3 activation and increased MAPK activation in T cells, an effect amplified by interleukin 10 (IL-10) receptor blockade. In RAW 264.7 cells, B16-F10-CS enhanced CHIKV infectivity without triggering activation. However, blocking the IL-10 receptor (IL-10R) in RAW 264.7 reduced CHIKV infection. CHIKV infection and IL-10R blockade synergistically inhibited B16-F10-CS-mediated polarisation of RAW 264.7 cells towards immunosuppressive macrophage. Our findings suggest that CHIKV modulates cancer-induced immunosuppression through IL-10-dependent pathways, providing new insights into viral-cancer interactions. This research may contribute to developing novel antiviral immunotherapies and virotherapies beneficial for cancer patients and immunocompromised individuals.

6.
Phys Rev Lett ; 132(22): 222501, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38877923

RESUMO

The known I^{π}=8_{1}^{+}, E_{x}=2129-keV isomer in the semimagic nucleus ^{130}Cd_{82} was populated in the projectile fission of a ^{238}U beam at the Radioactive Isotope Beam Factory at RIKEN. The high counting statistics of the accumulated data allowed us to determine the excitation energy, E_{x}=2001.2(7) keV, and half-life, T_{1/2}=57(3) ns, of the I^{π}=6_{1}^{+} state based on γγ coincidence information. Furthermore, the half-life of the 8_{1}^{+} state, T_{1/2}=224(4) ns, was remeasured with high precision. The new experimental information, combined with available data for ^{134}Sn and large-scale shell model calculations, allowed us to extract proton and neutron effective charges for ^{132}Sn, a doubly magic nucleus far-off stability. A comparison to analogous information for ^{100}Sn provides first reliable information regarding the isospin dependence of the isoscalar and isovector effective charges in heavy nuclei.

7.
Soft Matter ; 20(23): 4621-4632, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38819321

RESUMO

Knowledge about the dynamic nature of chromatin organization is essential to understand the regulation of processes like DNA transcription and repair. The existing models of chromatin assume that protein organization and chemical states along chromatin are static and the 3D organization is purely a result of protein-mediated intra-chromatin interactions. Here we present a new hypothesis that certain nonequilibrium processes, such as switching of chemical and physical states due to nucleosome assembly/disassembly or gene repression/activation, can also simultaneously influence chromatin configurations. To understand the implications of this inherent nonequilibrium switching, we present a block copolymer model of chromatin, with switching of its segmental states between two states, mimicking active/repressed or protein unbound/bound states. We show that competition between switching timescale Tt, polymer relaxation timescale τp, and segmental relaxation timescale τs can lead to non-trivial changes in chromatin organization, leading to changes in local compaction and contact probabilities. As a function of the switching timescale, the radius of gyration of chromatin shows a non-monotonic behavior with a prominent minimum when Tt ≈ τp and a maximum when Tt ≈ τs. We find that polymers with a small segment length exhibit a more compact structure than those with larger segment lengths. We also find that the switching can lead to higher contact probability and better mixing of far-away segments. Our study also shows that the nature of the distribution of chromatin clusters varies widely as we change the switching rate.


Assuntos
Cromatina , Cromatina/química , Modelos Moleculares , Nucleossomos/química , Nucleossomos/metabolismo , DNA/química
8.
Phys Chem Chem Phys ; 26(29): 19992-19999, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39005075

RESUMO

Classical molecular dynamics simulations are carried out on cationically ordered yttria-doped zirconia, YxZr1-xO2-x/2, at the dopant (Y3+) concentration of x = 12.5%. A variety of Zr4+/Y3+ ordered structures are examined for local migration pathways and microscopic energetics governing oxide ion transport in the system. Starting from a layer of cubic Y2O3 spanning the basal plane, the number of Y3+ layers in the simulation cell is multiplied systematically, at the expense of their coverage per layer. The study reveals that cationic ordering in YxZr1-xO2-x/2 can produce a profound impact on the oxide ion transport in the framework, wherein with the maximal dispersion of the dopant a four-fold enhancement in the ionic conductivity is observed relative to the cationically disordered matrix. We demonstrate that this improvement in ion mobility is due to the homogenization of oxide ion vacancies across the matrix. This study thus provides valuable insights for the enhancement of the electrochemical performance of solid oxide fuel cells.

9.
J Chem Ecol ; 50(7-8): 364-372, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38795224

RESUMO

Onion flowers require pollinator-mediated cross-pollination. However, the cues that pollinators use to locate the flowers are not well understood. The floral scent, along with floral visual cues, might acts as important signal to pollinators in order to locate the floral resources. We used electrophysiological methods combined with behavioural assays to determine which compounds in a floral scent are more attractive and thus biologically important to foraging scollid wasps. The majority of the molecules identified as floral fragrances in onions are common compounds that are already known from other angiosperms, and onion floral scents were predominately composed of aromatic components. The antennae of scoliid wasps responded to a large number of compounds, among them o-cymene, cis-ß-ocimene, benzaldehyde and allo-ocimene were behaviourally active. In contrast to other wasp flowers investigated nectar analysis demonstrated the dominance of hexose sugars over sucrose. Our findings provide fresh insights into the floral volatile chemistry of a key vegetable crop grown around the world. We demonstrate here that onion is using generalist floral volatiles to attract floral visitors. This insight could be utilised to make onion blooms more attractive to minor pollinators as well as major pollinators in order to maximise seed set.


Assuntos
Flores , Odorantes , Cebolas , Polinização , Compostos Orgânicos Voláteis , Vespas , Animais , Vespas/fisiologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/farmacologia , Flores/química , Cebolas/química , Odorantes/análise , Comportamento Animal/efeitos dos fármacos
10.
Environ Res ; 253: 119124, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38734294

RESUMO

Polyaromatic hydrocarbons (PAHs) are the most persistent compounds that get contaminated in the soil and water. Nearly 16 PAHs was considered to be a very toxic according US protection Agency. Though its concentration level is low in the environments but the effects due to it, is enormous. Advanced Oxidation Process (AOP) is an emergent methodology towards treating such pollutants with low and high molecular weight of complex substances. In this study, sulfate radical (SO4‾•) based AOP is emphasized for purging PAH from different sources. This review essentially concentrated on the mechanism of SO4‾• for the remediation of pollutants from different sources and the effects caused due to these pollutants in the environment was reduced by this mechanism is revealed in this review. It also talks about the SO4‾• precursors like Peroxymonosulfate (PMS) and Persulfate (PS) and their active participation in treating the different sources of toxic pollutants. Though PS and PMS is used for removing different contaminants, the degradation of PAH due to SO4‾• was presented particularly. The hydroxyl radical (•OH) mechanism-based methods are also emphasized in this review along with their limitations. In addition to that, different activation methods of PS and PMS were discussed which highlighted the performance of transition metals in activation. Also this review opened up about the degradation efficiency of contaminants, which was mostly higher than 90% where transition metals were used for activation. Especially, on usage of nanoparticles even 100% of degradation could be able to achieve was clearly showed in this literature study. This study mainly proposed the treatment of PAH present in the soil and water using SO4‾• with different activation methodologies. Particularly, it emphasized about the importance of treating the PAH to overcome the risk associated with the environment and humans due to its contamination.


Assuntos
Recuperação e Remediação Ambiental , Oxirredução , Hidrocarbonetos Policíclicos Aromáticos , Sulfatos , Sulfatos/química , Sulfatos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/química , Recuperação e Remediação Ambiental/métodos , Poluentes Ambientais/química , Poluentes Ambientais/análise
11.
Environ Res ; 260: 119768, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39134114

RESUMO

The development of biocompatible adsorbents is vital for environmental remediation to control and reduce pollution and waste accumulation in ecosystems. Biocompatible hydrogels represent an innovative class of materials that are primarily composed of polymer chain units forming their structural framework. They have a high affinity for water molecules. This research thus aims to incorporate iron oxide particles into the gelatin matrix to produce gelatin hydrogel beads to remove hexavalent chromium from an aqueous solution. The synthesized beads, known for their consistent size, low friction, high specific surface area, mechanical stability, and lightweight characteristics, demonstrated their suitability for various industrial applications. The effectiveness of these hydrogels in removing hexavalent chromium ions was confirmed through a thorough analysis using techniques such as FTIR, TGA, SEM, EDX, VSM, and XPS. Batch experiments revealed that the gelatin-based nanocomposite beads exhibited optimal adsorption efficiency under acidic conditions, lower initial concentrations of chromium ions, extended contact time, and elevated temperature (50-60 °C). The composite achieved a maximum removal efficiency of 99% at pH 1, with an adsorbent dose of 0.5 g at 50 °C, and an initial concentration of 50 mg per liter. The use of 0.7 N NaOH in the regeneration process resulted in a commendable 70.5% desorption efficiency, enabling potential reuse and regeneration. Significantly, the desorption efficiency remained consistently high even after four desorption-readsorption cycles, contributing to the economic and environmental sustainability of chromium removal. Additionally, the study determined that the sorption process was feasible, spontaneous, and endothermic. These collective findings suggest that magnetic gelatin hydrogel beads could serve as a cost-effective alternative adsorbent for the efficient removal of chromium ions from aqueous solutions.


Assuntos
Cromo , Gelatina , Hidrogéis , Nanopartículas de Magnetita , Poluentes Químicos da Água , Purificação da Água , Hidrogéis/química , Gelatina/química , Poluentes Químicos da Água/química , Cromo/química , Cromo/isolamento & purificação , Adsorção , Nanopartículas de Magnetita/química , Purificação da Água/métodos , Materiais Biocompatíveis/química
12.
Biotechnol Appl Biochem ; 71(4): 881-895, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38576028

RESUMO

Inflammatory bowel disease (IBD) imposes a significant impact on the quality of life for affected individuals. However, there was a current lack of a systematic summary regarding the latest epidemic trends and the underlying pathogenesis of IBD. This highlights the need for a thorough examination of both the epidemiological aspects of IBD and the specific mechanisms by which lactic acid bacteria (LAB) contribute to mitigating this condition. In developed countries, higher incidences and death rates of IBD have been observed, influenced by a combination of environmental and genetic factors. LAB offer significant advantages and substantial potential for enhancing IBD treatment. LAB's capabilities include the production of bioactive metabolites, regulation of gut immunity, protection of intestinal mechanical barriers, inhibition of oxidative damage, and restoration of imbalanced gut microbiota. The review suggests that screening effective LAB using cell models and metabolites, optimizing LAB intake through dose-effect studies, enhancing utilization through nanoencapsulation and microencapsulation, investigating mechanisms to deepen the understanding of LAB, and refining clinical study designs. These efforts aim to contribute to comprehending the epidemic trend, pathogenesis, and treatment of IBD, ultimately fostering the development of targeted therapeutic products, such as LAB-based interventions.


Assuntos
Doenças Inflamatórias Intestinais , Probióticos , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/metabolismo , Probióticos/uso terapêutico , Humanos , Lactobacillales/metabolismo , Lactobacillales/genética , Animais , Clonagem Molecular , Microbioma Gastrointestinal
13.
J Chem Phys ; 161(14)2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39377331

RESUMO

Stimuli-responsive polymers have gained significant research interest in recent years owing to their potential applications in diverse areas. Here, we present a study on the actuation characteristics of chitosan-based free-standing films that exhibit full reversibility and repeatability in response to water vapor exposure. The effect of pH of the water and the degree of cross-linking of the chitosan films on the actuation performance is studied. In the case of free-standing polymer film-based actuators, the primary driving force behind actuation is understood to be the differential strain induced by the gradient in volume changes across the thickness of the film. To understand it further, we conducted full atomistic molecular dynamics simulation studies to explore water absorption and adsorption into the chitosan matrix. Our simulations revealed an accumulation of water molecules in the surface layer that rapidly desorb when shielded from water vapor. Furthermore, estimates of the energy gain resulting from the adsorption of water on the surface suggest that it is adequate to drive the shape change of the actuator when subjected to asymmetric exposure to water vapor. This finding supports the fact that the adsorbed layer of water on the surface of the chitosan film plays a role in actuation.

14.
BMC Med Imaging ; 24(1): 230, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39223507

RESUMO

Breast cancer is a leading cause of mortality among women globally, necessitating precise classification of breast ultrasound images for early diagnosis and treatment. Traditional methods using CNN architectures such as VGG, ResNet, and DenseNet, though somewhat effective, often struggle with class imbalances and subtle texture variations, leading to reduced accuracy for minority classes such as malignant tumors. To address these issues, we propose a methodology that leverages EfficientNet-B7, a scalable CNN architecture, combined with advanced data augmentation techniques to enhance minority class representation and improve model robustness. Our approach involves fine-tuning EfficientNet-B7 on the BUSI dataset, implementing RandomHorizontalFlip, RandomRotation, and ColorJitter to balance the dataset and improve model robustness. The training process includes early stopping to prevent overfitting and optimize performance metrics. Additionally, we integrate Explainable AI (XAI) techniques, such as Grad-CAM, to enhance the interpretability and transparency of the model's predictions, providing visual and quantitative insights into the features and regions of ultrasound images influencing classification outcomes. Our model achieves a classification accuracy of 99.14%, significantly outperforming existing CNN-based approaches in breast ultrasound image classification. The incorporation of XAI techniques enhances our understanding of the model's decision-making process, thereby increasing its reliability and facilitating clinical adoption. This comprehensive framework offers a robust and interpretable tool for the early detection and diagnosis of breast cancer, advancing the capabilities of automated diagnostic systems and supporting clinical decision-making processes.


Assuntos
Neoplasias da Mama , Ultrassonografia Mamária , Humanos , Neoplasias da Mama/diagnóstico por imagem , Feminino , Ultrassonografia Mamária/métodos , Interpretação de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Inteligência Artificial
15.
Phytother Res ; 38(6): 2728-2763, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38522005

RESUMO

Women face a significant change in their reproductive health as menopause sets in. It is marred with numerous physiological changes that negatively impact their quality of life. This universal, transition phase is associated with menopausal and postmenopausal syndrome, which may spread over 2-10 years. This creates a depletion of female hormones causing physical, mental, sexual and social problems and may, later on, manifest as postmenopausal osteoporosis leading to weak bones, causing fractures and ultimately morbidity and mortality. Menopausal hormone therapy generally encompasses the correction of hormone balance through various pharmacological agents, but the associated side effects often lead to cessation of therapy with poor clinical outcomes. However, it has been noticed that phytotherapeutics is trusted by women for the amelioration of symptoms related to menopause and for improving bone health. This could primarily be due to their reduced side effects and lesser costs. This review attempts to bring forth the suitability of phytotherapeutics/herbals for the management of menopausal, postmenopausal syndrome, and menopausal osteoporosis through several published research. It tries to enlist the available botanicals with their key constituents and mechanism of action for mitigating symptoms associated with menopause as well as osteoporosis. It also includes a list of a few herbal commercial products available for these complications. The article also intends to collate the findings of various clinical trials and patents available in this field and provide a window for newer research avenues in this highly important yet ignored health segment.


Assuntos
Menopausa , Osteoporose Pós-Menopausa , Fitoterapia , Humanos , Feminino , Osteoporose Pós-Menopausa/tratamento farmacológico , Menopausa/efeitos dos fármacos , Qualidade de Vida , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico
16.
Clin Oral Investig ; 28(11): 606, 2024 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-39438333

RESUMO

OBJECTIVES: The objective of this paper was to compare the effectiveness of different materials for mouthguards in preventing oral and maxillofacial injuries during sports activities. The present study compares the stress-reduction and energy absorption capabilities of two other fused filament materials - poly(lactic-acid plus) (PLA+) and polycarbonate (PC), with Ethylene-vinyl acetate (EVA), which is the most commonly used material for mouthguard fabrication. MATERIALS AND METHODS: Two human skulls were modelled, and a boxing glove simulated punches along the x, y, and z-axes with 5 mm displacement with 1 kN force. Firstly, the maximum principal stress curve in the skull was compared for forces along the three perpendicular directions. Furthermore, the present study examines materials energy absorption properties, including their specific energy absorption characteristics and initial peak von Mises stresses. Additionally, a topology optimization approach is used to create an alternative design for a mouthguard to improve specific energy absorption. RESULTS: The model without a mouthguard showed the highest stress concentration of 32.298 MPa in the teeth, followed by the EVA material, which resulted in a maximum principal stress of 28.525 MPa. Fused filament 3D materials, such as PLA + and PC, on the other hand, showed better mechanical effectiveness in both lower jaw dislocation and lower maximum principal stress by 30.82% and 51.25% in the mandibular and maxillary teeth. Though EVA comparatively shows better specific energy absorption capability at 2.24 kJ/kg post-optimization than PLA + and PC, the peak principal stress experienced in the mandibular region was comparatively higher. The topology optimization, however, improved the energy-absorbing capabilities of PLA + by 4.5 times, reaching 1.37 kJ/kg and PC from 0.165 kJ/kg to 0.38 kJ/kg. CONCLUSIONS: This study demonstrates that PLA + and PC have better stress reduction capabilities than EVA and could be promising materials for the fabrication of mouthguards in sports activities. This study highlights the importance of topology optimization in dental materials science and engineering to develop safer and more effective mouthguard designs.


Assuntos
Desenho de Equipamento , Teste de Materiais , Protetores Bucais , Cimento de Policarboxilato , Poliésteres , Equipamentos Esportivos , Humanos , Poliésteres/química , Cimento de Policarboxilato/química , Polivinil/química , Traumatismos em Atletas/prevenção & controle , Estresse Mecânico , Traumatismos Maxilofaciais/prevenção & controle
17.
Clin Oral Investig ; 28(9): 492, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39167267

RESUMO

OBJECTIVES: To compare effectiveness of Autologous Particulate Dentin (APD) with Demineralized Freeze-Dried Bone Allograft (DFDBA) in ridge preservation, using radiographic and clinical parameters. MATERIALS AND METHODS: Thirty subjects with indication of mandibular posterior teeth extraction were randomly assigned to either test or control group. After atraumatic extraction, ridge preservation was performed using APD or DFDBA mixed with i-PRF in test and control groups respectively. Both groups had sockets sealed with A-PRF membrane. Clinical parameters (plaque, gingival and healing indices) and radiographic parameters (vertical ridge height, horizontal ridge width) were assessed at baseline and 6 months using CBCT. Statistical analysis was performed using an independent t-test to compare clinical and radiographic parameters between the groups. RESULTS: Both groups had significant decreases in ridge dimensions over 6 months (p < 0.001). The test group showed less reduction in ridge dimensions than control group at 6 months (p < 0.001). Mean change in vertical height was not significant (1.37 ± 1.32, 1.7311 ± 0.563), but in horizontal ridge width (1.3120 ± 1.13, 1.8093 ± 1.16) was significantly different between test and control groups respectively. There was no statistical difference in clinical parameters between the groups at 6 months (p > 0.001). CONCLUSIONS: APD grafts resulted in significant improvements in radiographic parameters, specifically in vertical ridge height and horizontal ridge width, compared to DFDBA group. CLINICAL RELEVANCE: Autologous particulate dentin is a promising, versatile substitute for regenerative procedures. While more research on its long-term efficacy and application is needed, current evidence suggests it could significantly improve patient care and outcomes.


Assuntos
Transplante Ósseo , Dentina , Liofilização , Extração Dentária , Humanos , Feminino , Masculino , Estudos Prospectivos , Dentina/diagnóstico por imagem , Transplante Ósseo/métodos , Extração Dentária/métodos , Adulto , Resultado do Tratamento , Mandíbula/cirurgia , Mandíbula/diagnóstico por imagem , Aumento do Rebordo Alveolar/métodos , Tomografia Computadorizada de Feixe Cônico , Pessoa de Meia-Idade , Alvéolo Dental/cirurgia , Alvéolo Dental/diagnóstico por imagem , Aloenxertos , Transplante Autólogo
18.
Cryo Letters ; 45(4): 257-268, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38809790

RESUMO

BACKGROUND: Little is known about the effects of different seasons on the cryopreservation success of buffalo sperm in terms of kinematics and sperm functional parameters. OBJECTIVE: To study the effect of three seasons (winter, comfort and summer) and cryopreservation on sperm kinematics and functional properties in buffalo bulls. MATERIALS AND METHODS: Semen ejaculates (n = 90) collected during three seasons i.e. winter (n = 30), comfort (n = 30), summer (n = 30) were evaluated for sperm kinematics and functional properties. RESULTS: Sperm kinematics with respect to total (TM), progressive (PM) and rapid motility (RM) was higher (P < 0.05) in fresh sperm compared to sperm that had been frozen-thawed. Similarly, all kinematic parameters [viz. average path velocity (VAP), straight linear velocity (VSL), curvilinear velocity (VCL), beats cross frequency (BCF), lateral head displacement (ALH), linearity (LIN) and straightness (STR)] were higher (P < 0.01) at the fresh stage. With respect to season, frozen-thawed semen TM (57.67 ± 115 %), PM (50.2 ± 1.15 %) and RM (51.6 ± 1.19 %) were higher (P < 0.01) when using sperm collected during winter. The stage of cryopreservation (i.e., equilibration and freeze-thawing) also showed significant effects (P < 0.01) on mitochondrial superoxide positive status (MSPS), mitochondrial membrane potential (MMP), acrosome status and intra-cellular calcium status. CONCLUSION: The season of sperm collection and cryopreservation have significant effects on buffalo bull sperm kinematics and functional properties. Doi.org/10.54680/fr24410110612.


Assuntos
Acrossomo , Búfalos , Cálcio , Criopreservação , Mitocôndrias , Preservação do Sêmen , Motilidade dos Espermatozoides , Espermatozoides , Animais , Criopreservação/veterinária , Criopreservação/métodos , Masculino , Búfalos/fisiologia , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Espermatozoides/fisiologia , Cálcio/metabolismo , Mitocôndrias/metabolismo , Fenômenos Biomecânicos , Estações do Ano , Potencial da Membrana Mitocondrial , Análise do Sêmen/veterinária
19.
Cryo Letters ; 45(1): 36-40, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38538370

RESUMO

BACKGROUND: Extensive dilution of cattle semen with tris-based extender compromises certain sperm kinetic and functional traits following cryopreservation. OBJECTIVE: To study sperm functions of buffalo bulls under high dilution rates. MATERIALS AND METHODS: Twenty-four ejaculates were harvested twice a week from four buffalo bulls, and diluted to sperm concentrations of 80, 60, 40 and 20 million/mL. Diluted samples were filled in straws, equilibrated at refrigeration temperature for 4 h, and frozen in liquid nitrogen. Frozen sperm samples were thawed for evaluation of kinetic and functional attributes. RESULTS: Compared to 20 million/mL (million/mL) sperm sample, the total motility, progressive motility and rapid motility were reduced (P < 0.05) in 5 million/mL sample. The proportion of live sperm were significantly (P < 0.05) higher in 10, 15 and 20 million/mL samples than in 5 million/mL sample. The percentage of moribund sperm, dead sperm, and sperm with lipid per oxidation increased significantly (P < 0.05) in 5 million/mL sample. CONCLUSION: The reduction of sperm concentrations to < 10 million/mL affects post-thaw Buffalo sperm kinetic and functional attributes.. https://doi.org/10.54680/fr24110110712.


Assuntos
Preservação do Sêmen , Sêmen , Animais , Bovinos , Masculino , Búfalos , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Preservação do Sêmen/veterinária , Criopreservação/veterinária , Crioprotetores , Espermatozoides , Análise do Sêmen/veterinária
20.
Environ Geochem Health ; 46(9): 308, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39001890

RESUMO

This study introduces a new biosorbent derived from Delonix regia bark-activated carbon to efficiently remove Chromium Cr(VI) metal ions from aqueous systems. The biosorbent was synthesized from the bark powder of the plant species and chemically activated with phosphoric acid. The biosorbent was characterized using FTIR, SEM, and BET to determine its functional properties and structural morphology. The batch adsorption experiments examined the optimal conditions for Cr(VI) metal ion adsorption, identifying that the highest removal efficiency occurred at pH levels of 2. The ideal adsorbent dosage was determined to be 2.5 g/L, with equilibrium achieved at a contact time of 60 min at the optimal temperature of about 303 K for a Cr(VI) metal ion concentration of 20 mg/L. Various isotherm models were applied to the adsorption equilibrium values, revealing that the adsorbent had a maximum removal capacity of approximately 224.8 mg/g for Cr(VI) metal ions. The adsorption process of Cr(VI) on the DAC biosorbent was best described by the Freundlich isotherm, indicating multilayer adsorption. The kinetic data fit well with the pseudo-second-order model. Thermodynamic parameters suggested that the adsorption process was spontaneous, exothermic, and feasible across different temperatures. Furthermore, the desorption studies showed that the DAC biosorbent can easily be rejuvenated and utilized several cycles with high adsorption capacity. These findings indicate that the developed adsorbent is environmentally friendly and effective for removing Cr(VI) from water systems.


Assuntos
Carvão Vegetal , Cromo , Casca de Planta , Poluentes Químicos da Água , Cromo/química , Adsorção , Casca de Planta/química , Poluentes Químicos da Água/química , Carvão Vegetal/química , Concentração de Íons de Hidrogênio , Purificação da Água/métodos , Cinética , Sapotaceae/química , Termodinâmica , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
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