Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 460
Filtrar
1.
ACS Omega ; 9(25): 26911-26921, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38947833

RESUMEN

Fast pyrolysis technology can reduce the secondary reactions, improve the volatile product yield, and reduce the semicoke yield. Still, the high proportion of heavy tar components affects the development of fast pyrolysis industrialization. Therefore, this paper put forward a catalytic upgrading method of coal based on the solid waste bauxite residue (BR) as a catalyst. This study investigated the impact of varying particle sizes of pulverized coal and the addition of the BR catalyst on the product distribution and kinetics of coal fast pyrolysis. The results found that the tar yield was the highest at 600 °C when the particle size of pulverized coal was 75-150 µm, which was 19.44%. In the range of 550-650 °C, the relative content of benzene and toluene xylene (BTX) in liquid products increased with the temperature. With the increase of the proportion of the BR catalyst, the yield of semicoke in coal pyrolysis products increased, the yield of the gas phase also increased, and the yield of the liquid phase decreased.

2.
Adv Sci (Weinh) ; : e2404071, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38958542

RESUMEN

α-halo alkylboronic esters, acting as ambiphilic synthons, play a pivotal role as versatile intermediates in fields like pharmaceutical science and organic chemistry. The sequential transformation of carbon-boron and carbon-halogen bonds into a broad range of carbon-X bonds allows for programmable bond formation, facilitating the incorporation of multiple substituents at a single position and streamlining the synthesis of complex molecules. Nevertheless, the synthetic potential of these compounds is constrained by limited reaction patterns. Additionally, the conventional methods often necessitate the use of bulk toxic solvents, exhibit sensitivity to air/moisture, rely on expensive metal catalysts, and involve extended reaction times. In this report, a ball milling technique is introduced that overcomes these limitations, enabling the external catalyst-free multicomponent coupling of aryl diazonium salts, alkenes, and simple metal halides. This approach offers a general and straightforward method for obtaining a diverse array of α-halo alkylboronic esters, thereby paving the way for the extensive utilization of these synthons in the synthesis of fine chemicals.

3.
Materials (Basel) ; 17(11)2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38893845

RESUMEN

In this paper, we conduct a comprehensive investigation into PVA fiber modified with SiO2 to improve the mechanical properties of oil-well cements. Specifically, SiO2 was coated onto the surface of polyvinyl alcohol fiber (PVAF) as its silicon source via a sol-gel process by using tetraethyl orthosilicate (TEOS), while hydrochloric acid and ammonia were respectively used as the catalyst in the sol (hydrolysis) and the gel (condensation) processes. The PVAF microstructure was then characterized with the scanning electron microscope (SEM), while the effects of the modified PVAF on both mechanical and rheological properties of oil-well cements were examined. Due to the fact that SiO2 can be uniformly coated onto the PVAF surface, such modified PVAF can slightly improve the rheology of the cement slurry, while the raw PVAF exhibits poor dispersion at a high dosage. Compared with those of cement stone without PVAF after curing for 28 days at 60 °C, the flexural strength, compressive strength, and elastic modulus of the cement stone incorporated with the modified PVAFs were enhanced by 37.7%, 66.1%, and 50.0%, respectively. The SEM test (EDX) test, XRD test, and thermogravimetric test prove that the SiO2 coating on the PVAF surface can promote the hydration of cement clinker and can react with Ca(OH)2 to generate CSH gel. The SiO2 grafted onto the surface of PVAFs can improve the bond strength at the fiber/cement matrix interface, thus improving the mechanical properties of cement stone.

4.
Ecotoxicol Environ Saf ; 280: 116588, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38878332

RESUMEN

Simultaneous heterotrophic nitrification and aerobic denitrification (SND) is gaining tremendous attention due to its high efficiency and low cost in water treatment. However, SND on an industrial scale is still immature since effects of coexisting pollutants, for example, heavy metals, on nitrogen removal remains largely unresolved. In this study, a HNAD bacterium (Pseudomonas sp. XF-4) was isolated. It could almost completely remove ammonium and nitrate at pH 5-9 and temperature 20 ℃-35 ℃ within 10 h, and also showed excellently simultaneous nitrification and denitrification efficiency under the coexistence of any two of inorganic nitrogen sources with no intermediate accumulation. XF-4 could rapidly grow again after ammonium vanish when nitrite or nitrate existed. There was no significant effects on nitrification and denitrification when Cd(II) was lower than 10 mg/L, and 95 % of Cd(II) was removed by XF-4. However, electron carrier and electron transport system activity was inhibited, especially at high concentration of Cd(II). Overall, this study reported a novel strain capable of simultaneous nitrification and denitrification coupled with Cd(II) removal efficiently. The results provided new insights into treatment of groundwater or wastewater contaminated by heavy metals and nitrogen.


Asunto(s)
Cadmio , Desnitrificación , Nitrificación , Nitrógeno , Pseudomonas , Contaminantes Químicos del Agua , Cadmio/metabolismo , Pseudomonas/metabolismo , Contaminantes Químicos del Agua/metabolismo , Nitrógeno/metabolismo , Procesos Heterotróficos , Nitratos/metabolismo , Aguas Residuales/microbiología , Aguas Residuales/química , Biodegradación Ambiental , Aerobiosis , Purificación del Agua/métodos , Compuestos de Amonio/metabolismo
5.
bioRxiv ; 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38895361

RESUMEN

Land plant organellar genomes have extremely low rates of point mutation yet also experience high rates of recombination and genome instability. Characterizing the molecular machinery responsible for these patterns is critical for understanding the evolution of these genomes. While much progress has been made towards understanding recombination activity in land plant organellar genomes, the relationship between recombination pathways and point mutation rates remains uncertain. The organellar targeted mutS homolog MSH1 has previously been shown to suppress point mutations as well as non-allelic recombination between short repeats in Arabidopsis thaliana. We therefore implemented high-fidelity Duplex Sequencing to test if other genes that function in recombination and maintenance of genome stability also affect point mutation rates. We found small to moderate increases in the frequency of single nucleotide variants (SNVs) and indels in mitochondrial and/or plastid genomes of A. thaliana mutant lines lacking radA, recA1, or recA3. In contrast, osb2 and why2 mutants did not exhibit an increase in point mutations compared to wild type (WT) controls. In addition, we analyzed the distribution of SNVs in previously generated Duplex Sequencing data from A. thaliana organellar genomes and found unexpected strand asymmetries and large effects of flanking nucleotides on mutation rates in WT plants and msh1 mutants. Finally, using long-read Oxford Nanopore sequencing, we characterized structural variants in organellar genomes of the mutant lines and show that different short repeat sequences become recombinationally active in different mutant backgrounds. Together, these complementary sequencing approaches shed light on how recombination may impact the extraordinarily low point mutation rates in plant organellar genomes.

6.
J Obstet Gynaecol ; 44(1): 2372645, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38943550

RESUMEN

BACKGROUND: This study examined the improvement of dysmenorrhoea and menorrhagia after uterine artery embolisation (UAE) in women with symptomatic adenomyosis and identified factors that could predict the improvement of dysmenorrhoea and menorrhagia. METHODS: This retrospective study included women with adenomyosis who underwent bilateral UAE between December 2014 and December 2016. The percentage of the volume of the absence of contrast enhancement on T1-weighted images was evaluated 5-7 days after UAE. A receiver operating characteristic (ROC) analysis was used to determine a cut-off point and predict the improvement of dysmenorrhoea and menorrhagia. RESULTS: Forty-eight patients were included. At 24 and 36 months after UAE, the improvement rates for dysmenorrhoea and menorrhagia were 60.4% (29/48) and 85.7% (30/35), and the recurrence rates were 19.4% (7/36) and 9.1% (3/33), respectively. Only the percentage of the volume of the absence of contrast enhancement on T1-weighted images was associated with the improvement of dysmenorrhoea (p = 0.001, OR = 1.051; 95% CI: 1.02-1.08) and menorrhagia (p = 0.006, OR = 1.077; 95% CI: 1.021-1.136). When the cut-off value of the ROC analysis was 73.1%, sensitivity, specificity, positive predictive value, and negative predictive value for the improvement of dysmenorrhoea were 58.6%, 94.7%, 94.4%, and 60%, while they were 58.9%, 80%, 100%, 100%, and 45.5% for the improvement of dysmenorrhoea. CONCLUSION: Bilateral UAE for symptomatic adenomyosis led to good improvement of dysmenorrhoea and menorrhagia. The percentage of the volume of the absence of contrast enhancement on T1-weighted images of the uterus in postoperative magnetic resonance imaging might be associated with the improvement of dysmenorrhoea and menorrhagia.


This study examined the improvement of dysmenorrhoea and menorrhagia after uterine artery embolisation in women with symptomatic adenomyosis and identified factors that could predict the improvement of dysmenorrhoea and menorrhagia. This retrospective study included women with adenomyosis who underwent uterine artery embolisation. A total of 48 patients were included. Only the percentage of the volume of the absence of contrast enhancement on T1-weighted images was associated with improvement of dysmenorrhoea and menorrhagia. Bilateral uterine artery embolisation for symptomatic adenomyosis led to good improvement. The percentage of the volume of the absence of contrast enhancement on images in postoperative T1-weighted magnetic resonance imaging of the uterus might be associated with the improvement of dysmenorrhoea and menorrhagia.


Asunto(s)
Adenomiosis , Dismenorrea , Menorragia , Embolización de la Arteria Uterina , Humanos , Femenino , Menorragia/etiología , Menorragia/terapia , Adenomiosis/complicaciones , Dismenorrea/etiología , Dismenorrea/terapia , Estudios Retrospectivos , Embolización de la Arteria Uterina/métodos , Adulto , Resultado del Tratamiento , Persona de Mediana Edad , Imagen por Resonancia Magnética , Curva ROC
7.
Cancer Lett ; 597: 217047, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38871245

RESUMEN

Bone metastasis is common in breast cancer and more effective therapies are required, however, its molecular mechanism is poorly understood. Additionally, the role of the m6A reader YTHDF1 in bone metastasis of breast cancer has not been reported. Here, we reveal that the increased expression of YTHDF1 is clinically correlated with breast cancer bone metastases. YTHDF1 promotes migration, invasion, and osteoblast adhesion and induces osteoclast differentiation of cancer cells in vitro and vivo. Mechanically, RNA-seq, MeRIP-seq and RIP-seq analysis, and molecular biology experiments demonstrate that YTHDF1 translationally enhances EZH2 and CDH11 expression by reading m6A-enriched sites of their transcripts. Moreover, adeno-associated virus (AAV) was used to deliver shYTHDF1 (shYTHDF1-AAV) in intratibial injection models, eliciting a significant suppressive effect on breast cancer bone metastatic formation and osteolytic destruction. Overall, we uncovered that YTHDF1 promotes osteolytic bone metastases of breast cancer by inducing EZH2 and CDH11 translation.

8.
Front Plant Sci ; 15: 1404071, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38887455

RESUMEN

Backgrounds: Prunus mume in the Rosaceae and commonly referred to as mei or Chinese plum is widely used as a traditional ornamental flowering plant and fruit tree in China. Although some population and genetic analyses have been conducted for this species, no extensive comparisons of genetic variation from plastomes have yet been investigated. Methods: We de novo assembled a total of 322 complete P. mume plastomes in this study and did a series of comparative analyses to better resolve pan-plastomic patterns of P. mume. To determine the phylogeny and domestication history of this species, we reconstructed the phylogenetic tree of Prunus genus, and resolved the population structure of P. mume. We also examined the nucleotide variation of P. mume to find potential DNA barcodes. Results: The assembled plastomes exhibited a typical quadripartite structure and ranged from 157,871 bp to 158,213 bp in total size with a GC content ranging from 36.73 to 36.75%. A total of 112 unique genes were identified. Single nucleotide variants (SNVs) were the most common variants found among the plastomes, followed by nucleotide insertions/deletions (InDels), and block substitutions with the intergenic spacer (IGS) regions containing the greatest number of variants. From the pan-plastome data six well-supported genetic clusters were resolved using multiple different population structure analyses. The different cultivars were unevenly distributed among multiple clades. We also reconstructed a phylogeny for multiple species of Prunus to better understand genus level diversity and history from which a complex introgressive relationship between mei and other apricots/plums was resolved. Conclusion: This study constructed the pan-plastome of P. mume, which indicated the domestication of P. mume involved multiple genetic origins and possible matrilineal introgression from other species. The phylogenetic analysis in Prunus and the population structure of P. mume provide an important maternal history for Prunus and the groundwork for future studies on intergenomic sequence transfers, cytonuclear incompatibility, and conservation genetics.

9.
Cancer Biol Med ; 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38940672

RESUMEN

OBJECTIVE: Radiotherapy has achieved remarkable effects in treating non-small cell lung cancer (NSCLC). However, radioresistance remains the major obstacle to achieving good outcomes. This study aims at identifying potential targets for radiosensitizing NSCLC and elucidating the underlying mechanisms. METHODS: Lentivirus-based infection and CRISPR/Cas9 technology were used to modulate the expression of microRNA-384 (miR-384). Cell clonogenic formation assays and a xenograft tumor model were used to analyze radiosensitivity in NSCLC cells. Fluorescence-activated cell sorting was used to assess the cell cycle and cell death. Immunofluorescence staining, Comet assays, and homologous recombination or non-homologous end-joining I-SceI/GFP reporter assays were used to study DNA damage and repair. Western blotting and quantitative real-time polymerase chain reaction were used to identify the targets of miR-384. Chromatin immunoprecipitation and polymerase chain reaction were performed to evaluate upstream regulators of miR-384. RESULTS: MiR-384 was downregulated in NSCLC. Overexpression of miR-384 increased the radiosensitivity of NSCLC cells in vitro and in vivo, whereas knockout of miR-384 led to radioresistance. Upregulation of miR-384 radiosensitized NSCLC cells by decreasing G2/M cell cycle arrest, inhibiting DNA damage repair, and consequently increasing cell death; miR-384 depletion had the opposite effects. Further investigation revealed that ATM, Ku70, and Ku80 were direct targets of miR-384. Moreover, miR-384 was repressed by NF-κB. CONCLUSIONS: MiR-384 is an ionizing radiation-responsive gene repressed by NF-κB. MiR-384 enhances the radiosensitivity of NSCLC cells via targeting ATM, Ku80, and Ku70, which impairs DNA damage repair. Therefore, miR-384 may serve as a novel radiosensitizer for NSCLC.

10.
Cancer Lett ; 595: 217000, 2024 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-38821254

RESUMEN

Radiotherapy is one of the predominant treatment modalities for almost all kinds of malignant cancers, including non-small cell lung cancer (NSCLC). Increasing evidence shows that ionizing radiation (IR) induces reactive oxygen species (ROS) leading to lipid peroxidation and subsequently ferroptosis of cancer cells. However, cancer cells evolve multiple mechanisms against ROS biology resulting in resistance to ferroptosis and radiotherapy, of which NRF2 signaling is one of the most studied. In the current research, we identified that microRNA-139 (miR-139) could be a novel radiosensitizer for NSCLC by inhibiting NRF2 signaling. We found that miR-139 possessed great potential as a diagnostic biomarker for NSCLC and multiple other types of cancer. Overexpression of miR-139 increased radiosensitivity of NSCLC cells in vitro and in vivo. MiR-139 directly targeted cJUN and KPNA2 to impair NRF2 signaling resulting in enhanced IR-induced lipid peroxidation and cellular ferroptosis. We proved KPNA2 to be a binding partner of NRF2 that involved in nuclear translocation of NRF2. Moreover, we found that IR induced miR-139 expression through transcriptional factor EGR1. EGR1 bound to the promoter region and transactivated miR-139. Overall, our findings elucidated the effect of EGR1/miR-139/NRF2 in IR-induced ferroptosis of NSCLC cells and provided theoretical support for the potential diagnostic biomarkers and therapeutic targets for the disease.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Proteína 1 de la Respuesta de Crecimiento Precoz , Ferroptosis , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares , MicroARNs , Factor 2 Relacionado con NF-E2 , Tolerancia a Radiación , Transducción de Señal , MicroARNs/genética , MicroARNs/metabolismo , Humanos , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Ferroptosis/genética , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/metabolismo , Tolerancia a Radiación/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Animales , Línea Celular Tumoral , Ratones , Masculino , Especies Reactivas de Oxígeno/metabolismo , Células A549 , Ratones Desnudos , Femenino
11.
Small ; : e2401815, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38573922

RESUMEN

Currently, research on thermal interface materials (TIMs) is primarily focused on enhancing thermal conductivity. However, strong adhesion and multifunctionality are also important characteristics for TIMs when pursing more stable interface heat conduction. Herein, a novel poly(urethane-urea-imide) (PUUI) elastomer containing abundant dynamic hydrogen bonds network and reversible disulfide linkages is successfully synthesized for application as a TIM matrix. The PUUI can self-adapt to the metal substrate surface at moderate temperatures (80 °C) and demonstrates a high adhesion strength of up to 7.39 MPa on aluminum substrates attributed its noncovalent interactions and strong intrinsic cohesion. Additionally, the PUUI displays efficient self-healing capability, which can restore 94% of its original mechanical properties after self-healing for 6 h at room temperature. Furthermore, PUUI composited with aluminum nitride and liquid metal hybrid fillers demonstrates a high thermal conductivity of 3.87 W m-1 K-1 while maintaining remarkable self-healing capability and adhesion. When used as an adhesive-type TIM, it achieves a low thermal contact resistance of 22.1 mm2 K W-1 at zero pressure, only 16.7% of that of commercial thermal pads. This study is expected to break the current research paradigm of TIMs and offers new insights for the development of advanced, reliable, and sustainable TIMs.

12.
Ecol Evol ; 14(4): e11320, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38681184

RESUMEN

The climate fluctuations during the Late Pleistocene significantly influenced the phylogeographic structure and historical dynamics of marine fishes in the marginal seas of the western Pacific Ocean. The puffer fish, Lagocephalus spadiceus, holds substantial nutritional and economic value in the South China Sea. To investigate the demographic history and population structure of the L. spadiceus, the mitochondrial DNA COI and Cyt b gene datasets from 300 individuals across eight populations in the South China Sea were sequenced. Our findings revealed high haplotype diversity (0.874 ± 0.013) and low nucleotide diversity (0.00075 ± 0.00058). The phylogenetic tree and haplotype networks revealed no significant genetic differentiation along the northern coast of South China Sea. Neutrality tests, mismatch distribution analyses, and Bayesian skyline plots suggested that L. spadiceus underwent population expansion during the Late Pleistocene. Both ocean currents and climate change significantly influenced the geographical distribution and genetic population structure of L. spadiceus.

13.
Mol Hortic ; 4(1): 14, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38622744

RESUMEN

Roses are consistently ranked at the forefront in cut flower production. Increasing demands of market and changing climate conditions have resulted in the need to further improve the diversity and quality of traits. However, frequent hybridization leads to highly heterozygous nature, including the allelic variants. Therefore, the absence of comprehensive genomic information leads to them making it challenging to molecular breeding. Here, two haplotype-resolved chromosome genomes for Rosa chinensis 'Chilong Hanzhu' (2n = 14) which is high heterozygous diploid old Chinese rose are generated. An amount of genetic variation (1,605,616 SNPs, 209,575 indels) is identified. 13,971 allelic genes show differential expression patterns between two haplotypes. Importantly, these differences hold valuable insights into regulatory mechanisms of traits. RcMYB114b can influence cyanidin-3-glucoside accumulation and the allelic variation in its promoter leads to differences in promoter activity, which as a factor control petal color. Moreover, gene family expansion may contribute to the abundance of terpenes in floral scents. Additionally, RcANT1, RcDA1, RcAG1 and RcSVP1 genes are involved in regulation of petal number and size under heat stress treatment. This study provides a foundation for molecular breeding to improve important characteristics of roses.

14.
Genes (Basel) ; 15(4)2024 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-38674377

RESUMEN

The plastid organelle is vital for photosynthesis and energy production. Advances in sequencing technology have enabled the exploration of plastomic resources, offering insights into plant evolution, diversity, and conservation. As an important group of horticultural ornamentals in the Crassulaceae family, Sempervivum plants are known for their unique rosette-like structures and reproduction through offsets. Despite their popularity, the classification status of Sempervivum remains uncertain, with only a single plastome sequence currently available. Furthermore, codon usage bias (CUB) is a widespread phenomenon of the unbalanced usage of synonymous codons in the coding sequence (CDS). However, due to the limited available plastid data, there has been no research that focused on the CUB analysis among Sempervivum until now. To address these gaps, we sequenced and released the plastomes of seven species and one subspecies from Sempervivum, revealing several consistent patterns. These included a shared 110 bp extension of the rps19 gene, 14 hypervariable regions (HVRs) with distinct nucleotide diversity (π: 0.01173 to 0.02702), and evidence of selective pressures shaping codon usage. Notably, phylogenetic analysis robustly divided the monophyletic clade into two sections: Jovibarba and Sempervivum. In conclusion, this comprehensive plastomic resource provides valuable insights into Sempervivum evolution and offers potential molecular markers for DNA barcoding.


Asunto(s)
Filogenia , Plastidios , Plastidios/genética , Uso de Codones , Genoma de Plastidios/genética , Evolución Molecular
15.
Hortic Res ; 11(3): uhae023, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38469379

RESUMEN

Complete mitochondrial genomes (mitogenomes) of plants are valuable resources for nucleocytoplasmic interactions, plant evolution, and plant cytoplasmic male sterile line breeding. However, the complete assembly of plant mitogenomes is challenging due to frequent recombination events and horizontal gene transfers. Previous studies have adopted Illumina, PacBio, and Nanopore sequencing data to assemble plant mitogenomes, but the poor assembly completeness, low sequencing accuracy, and high cost limit the sampling capacity. Here, we present an efficient assembly toolkit (PMAT) for de novo assembly of plant mitogenomes using low-coverage HiFi sequencing data. PMAT has been applied to the de novo assembly of 13 broadly representative plant mitogenomes, outperforming existing organelle genome assemblers in terms of assembly accuracy and completeness. By evaluating the assembly of plant mitogenomes from different sequencing data, it was confirmed that PMAT only requires 1× HiFi sequencing data to obtain a complete plant mitogenome. The source code for PMAT is available at https://github.com/bichangwei/PMAT. The developed PMAT toolkit will indeed accelerate the understanding of evolutionary variation and breeding application of plant mitogenomes.

16.
Proc Natl Acad Sci U S A ; 121(10): e2317240121, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38427600

RESUMEN

Nuclear and organellar genomes can evolve at vastly different rates despite occupying the same cell. In most bilaterian animals, mitochondrial DNA (mtDNA) evolves faster than nuclear DNA, whereas this trend is generally reversed in plants. However, in some exceptional angiosperm clades, mtDNA substitution rates have increased up to 5,000-fold compared with closely related lineages. The mechanisms responsible for this acceleration are generally unknown. Because plants rely on homologous recombination to repair mtDNA damage, we hypothesized that mtDNA copy numbers may predict evolutionary rates, as lower copy numbers may provide fewer templates for such repair mechanisms. In support of this hypothesis, we found that copy number explains 47% of the variation in synonymous substitution rates of mtDNA across 60 diverse seed plant species representing ~300 million years of evolution. Copy number was also negatively correlated with mitogenome size, which may be a cause or consequence of mutation rate variation. Both relationships were unique to mtDNA and not observed in plastid DNA. These results suggest that homologous recombinational repair plays a role in driving mtDNA substitution rates in plants and may explain variation in mtDNA evolution more broadly across eukaryotes. Our findings also contribute to broader questions about the relationships between mutation rates, genome size, selection efficiency, and the drift-barrier hypothesis.


Asunto(s)
Variaciones en el Número de Copia de ADN , Genoma , Animales , ADN de Plantas/genética , Variaciones en el Número de Copia de ADN/genética , Filogenia , ADN Mitocondrial/genética , Plantas/genética
17.
J Hepatocell Carcinoma ; 11: 399-409, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38435682

RESUMEN

Purpose: Local in combination with systemic therapy might be an option for patients with advanced unresectable hepatocellular carcinoma (uHCC). This study examined the clinical benefits and adverse events (AEs) of first-line transarterial embolization (TAE) and hepatic arterial infusion chemotherapy (HAIC) combined with atezolizumab (Atezo) and bevacizumab (Bev) in patients with uHCC of a diameter larger than 8 cm. Patients and methods: This retrospective study included patients with uHCC of a diameter larger than 8 cm who were treated with first-line Atezo-Bev and TAE+HAIC at the First Affiliated Hospital of Sun Yat-Sen University between September 30, 2019, and September 30, 2022. Progression-free survival (PFS), overall survival (OS), tumor response according to mRECIST, and AEs were analyzed. Multivariable Cox analyses were performed to examine the factors associated with PFS. Results: Thirty patients were included. The objective response rate (ORR) was 74.4% (95% confidence interval [CI], 59.3%-89.5%), and the disease control rate (DCR) was 93.3% (95% CI, 85.4%-98.6%). The median follow-up was 11.4 (inter-quartile range [IQR], 5.5-17.9) months. The median PFS was 6.8 (95% CI, 2.6-11.1) months. The 3-, 6-, 9-, and 12-month survival rates were 86.2%, 82.5%, 68.6%, and 60%, respectively. The median OS was not estimated. Extrahepatic metastasis was independently associated with PFS (hazard ratio [HR]=3.468, 95% CI, 1.001-12.023). The most common AEs were fever (46.7%). Grade 4 AEs occurred one time as hematemesis but no 5 AEs were observed. Conclusion: Atezo-Bev combined with TAE and HAIC might benefit patients with uHCC of a diameter larger than 8 cm, with manageable AEs.

18.
Int J Surg Case Rep ; 117: 109530, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38518472

RESUMEN

INTRODUCTION: Upper limb soft tissue sarcomas are extremely rare and can be misdiagnosed as benign, leading to unplanned excisions. Unplanned excisions and local recurrences pose significant challenges for the subsequent treatment of patients. PRESENTATION OF CASE: A patient with a forearm soft tissue sarcoma who underwent unplanned excisions and experienced multiple recurrences. In the most recent treatment, she underwent wide tumor excision combined with thigh free flap transplantation for reconstruction. The reconstruction surgery successfully addressed the extensive soft tissue defect. During the three-year follow-up, there was no tumor recurrence observed, alongside the restoration of upper arm function. DISCUSSION: Challenges and considerations in the treatment of soft tissue sarcomas (STS) are discussed. CONCLUSION: Unplanned excisions and local recurrences of upper limb soft tissue sarcomas present significant challenges for surgery. Patients should be referred to specialized cancer centers for multidisciplinary diagnosis and treatment.

19.
Carbohydr Polym ; 331: 121886, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38388040

RESUMEN

The use of natural starch as a replacement for petroleum-based packaging materials is limited due to its poor processability, weak mechanical properties, and strong moisture sensitivity. To address these limitations, this study adopts molecular design of hydroxypropylation and acetylation to sequentially modify natural starch, and material design of introducing acetylated cellulose nanofibers (ACNF) into the starch matrix to reinforce the material. Hydroxypropylation decreased the interaction force between the starch molecular chains, thereby reducing the glass transition temperature. Subsequent acetylation introduced hydrophobic acetyl groups that disrupted intermolecular hydrogen bonds, enhancing the mobility of the starch molecular chain, and endowed the hydroxypropyl starch acetate (HPSA) with excellent thermoplastic processability (melt index of 7.12 g/10 min) without the need for plasticizers and notable water resistance (water absorption rate of 3.0 %). The introduction of ACNF generated a strong interaction between HPSA chains, promoting the derived ACNF-HPSA to exhibit excellent mechanical strength, such as high impact strength of 2.1 kJ/m2, tensile strength of 22.89 MPa, elasticity modulus of 813.22 MPa, flexural strength of 24.18 MPa and flexural modulus of 1367.88 MPa. Its overall performance even surpassed that of polypropylene (PP) plastic, making it a potential alternative material for PP-based packaging materials.

20.
Transl Oncol ; 42: 101861, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38301409

RESUMEN

Beta-Parvin (PARVB) is an actin-binding protein with functionality in extracellular matrix binding. Recent studies suggest its potential as a biomarker for various cancers, given its role in governing several malignancies. Yet, its involvement and modulatory mechanisms in malignant melanoma remain under-explored.  In this research, we undertook a comprehensive pan-cancer analysis centered on PARVB. We probed its aberrant expression and prognostic implications, and assessed correlations between PARVB expression and immunocyte infiltration. This expression was subsequently corroborated using clinical samples. Both in vitro and in vivo, we discerned the functional ramifications of PARVB on melanoma. Furthermore, we scrutinized how HIF-1α/2α modulates PARVB and initiated a preliminary investigation into potential downstream pathways influenced by PARVB. Our results illuminate that elevated PARVB expression manifests across various tumors and significantly influences the prognosis of multiple cancers, emphasizing its peculiar expression and prognostic relevance in melanoma. Augmented PARVB levels were inversely proportional to immunocyte penetration in melanoma. Silencing PARVB curtailed cellular proliferation, migration, and invasion in vitro and decelerated tumor expansion in vivo. Notably, hypoxic conditions, triggering HIF-1α/2α activation, appear to elevate PARVB expression by anchoring to the hypoxia-specific responsive element within the PARVB promoter. Enhanced PARVB levels seem intertwined with the activation of cellular proliferation circuits and the damping of inflammatory trajectories. Collectively, these revelations posit PARVB as a potential prognostic indicator and therapeutic linchpin for malignant melanoma.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...