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2.
Ecol Evol ; 14(5): e11364, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38698929

RESUMEN

Plot-scale experiments indicate that functional diversity (FD) plays a pivotal role in sustaining ecosystem functions such as net primary productivity (NPP). However, the relationships between functional diversity and NPP across larger scale under varying climatic conditions are sparsely studied, despite its significance for understanding forest-atmosphere interactions and informing policy development. Hence, we examine the relationships of community-weighted mean (CWM) and functional dispersion (FDis) of woody plant traits on NPP across China and if such relationships are modulated by climatic conditions at the national scale. Using comprehensive datasets of distribution, functional traits, and productivity for 9120 Chinese woody plant species, we evaluated the distribution pattern of community-weighted mean and functional dispersion (including three orthogonal trait indicators: plant size, leaf morphology, and flower duration) and its relationships with NPP. Finally, we tested the effects of climatic conditions on community-weighted mean/functional dispersion-NPP relationships. We first found overall functional diversity-NPP relationships, but also that the magnitude of these relationships was sensitive to climate, with plant size community-weighted mean promoting NPP in warm regions and plant size functional dispersion promoting NPP in wet regions. Second, warm and wet conditions indirectly increased NPP by its positive effects on community-weighted mean or functional dispersion, particularly through mean plant size and leaf morphology. Our study provides comprehensive evidence for the relationships between functional diversity and NPP under varying climates at a large scale. Importantly, our results indicate a broadening significance of multidimensional plant functional traits for woody vegetation NPP in response to rising temperatures and wetter climates. Restoration, reforestation actions and natural capital accounting need to carefully consider not only community-weighted mean and functional dispersion but also their interactions with climate, to predict how functional diversity may promote ecosystem functioning under future climatic conditions.

3.
Appl Opt ; 63(9): 2241-2247, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38568578

RESUMEN

For conventional refractive lenses, chromatic aberration inevitably occurs due to the refractive index variation of the lens material with the incident wavelength, leading to axial aberrations and lower imaging system quality. Achromatic metalenses have demonstrated a great capability to solve this problem and been extensively investigated. However, the metalens achromatic method involves construction of a unit structure satisfying a phase distribution greater than 0-2π or phase compensation. Although this design method can obtain a good achromatic effect, finding a unit that satisfies a linear distribution during design is difficult. In this paper, we use subregion discrete wavelength modulation to achieve broadband achromatism. The total number of structural units in each region is optimized for different incident wavelengths, and the internal and external ring unit structures are also optimized. This achromatic metalens exhibits a large aperture and a high numerical aperture in the 4.2-4.7 µm mid-infrared band (NA = 0.83). Our research has strong potential and application prospects in ultracompact imaging and laser beam shaping.

4.
Vaccines (Basel) ; 12(4)2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38675793

RESUMEN

OBJECTIVE: This study aimed to provide clinical evidence for lineage replacement and genetic changes of High-Risk Human Papillomavirus (HR-HPV) during the period of vaccine coverage and characterize those changes in eastern China. METHODS: This study consisted of two stages. A total of 90,583 patients visiting the Obstetrics and Gynecology Hospital of Fudan University from March 2018 to March 2022 were included in the HPV typing analysis. Another 1076 patients who tested positive for HPV31, 33, 52, or 58 from November 2020 to August 2023 were further included for HPV sequencing. Vaccination records, especially vaccine types and the third dose administration time, medical history, and cervical cytology samples were collected. Viral DNA sequencing was then conducted, followed by phylogenetic analysis and sequence alignment. RESULTS: The overall proportion of HPV31 and 58 infections increased by 1.23% and 0.51%, respectively, while infection by HPV33 and 52 decreased by 0.42% and 1.43%, respectively, within the four-year vaccination coverage period. The proportion of HPV31 C lineage infections showed a 22.17% increase in the vaccinated group, while that of the HPV58 A2 sublineage showed a 12.96% increase. T267A and T274N in the F-G loop of HPV31 L1 protein, L150F in the D-E loop, and T375N in the H-I loop of HPV58 L1 protein were identified as high-frequency escape-related mutations. CONCLUSIONS: Differences in epidemic lineage changes and dominant mutation accumulation may result in a proportional difference in trends of HPV infection. New epidemic lineages and high-frequency escape-related mutations should be noted during the vaccine coverage period, and regional epidemic variants should be considered during the development of next-generation vaccines.

5.
Front Plant Sci ; 15: 1362149, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38516660

RESUMEN

The improvement of nutrients in soil is essential for using deserts and decertified ecosystems and promoting sustainable agriculture. Grapevines are suitable crops for desert soils as they can adapt to harsh environments and effectively impact soil nutrients; however, the mechanisms underlying this remain unclear. This study explored the impact of the different duration(3, 6, and 10 years) of grape cultivation on soil organic carbon, physicochemical properties, enzyme activities, microbial communities, and carbon cycle pathways in both rhizosphere and bulk soils. Partial least squares path modeling was used to further reveal how these factors contributed to soil nutrient improvement. Our findings indicate that after long-term grape cultivation six years, soil organic carbon, total nitrogen, total phosphorus, microbial biomass carbon and nitrogen, and enzyme activities has significantly increased in both rhizosphere and bulk soils but microbial diversity decreased in bulk soil. According to the microbial community assembly analysis, we found that stochastic processes, particularly homogenizing dispersal, were dominant in both soils. Bacteria are more sensitive to environmental changes than fungi. In the bulk soil, long-term grape cultivation leads to a reduction in ecological niches and an increase in salinity, resulting in a decrease in soil microbial diversity. Soil enzymes play an important role in increasing soil organic matter in bulk soil by decomposing plant litters, while fungi play an important role in increasing soil organic matter in the rhizosphere, possibly by decomposing fine roots and producing mycelia. Our findings enhance understanding of the mechanisms of soil organic carbon improvement under long-term grape cultivation and suggest that grapes are suitable crops for restoring desert ecosystems.

6.
Transl Res ; 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38494125

RESUMEN

Hepatic ischemia reperfusion (I/R) injury is a common clinical complication. X-box binding protein 1 (XBP1), as a critical regulator of the endoplasmic reticulum stress, has been implicated in a variety of diseases. In this study, we aimed to investigate the effects and the underlying mechanism of XBP1 in the progression of hepatic I/R injury. Hepatocyte-specific XBP1 knockout mice, multiple viral delivery systems and specific pharmacological inhibitors were applied in vivo in a partial hepatic I/R injury mouse model and in vitro in a cell model of hypoxia-reoxygenation (H/R) injury. Mitophagy and autophagic flux were evaluated and fluorescence resonance energy transfer (FRET) as well as immunoprecipitation were performed. The results demonstrated that reperfusion for 6 h represented a critical timepoint in hepatic I/R injury and resulted in significant intracellular mitochondrial dysfunction; led to the breakdown of hepatocytes accompanied by the highest expression levels of XBP1. Hepatocyte-specific XBP1 knockout alleviated hepatic I/R injury via enhanced mitophagy, as demonstrated by the reduction in hepatocellular damage/necrosis and increased expression of mitophagy markers. Mechanistically, XBP1 interacted with FoxO1 directly and catalyzed the ubiquitination of FoxO1 for proteasomal degradation. Targeting XBP1 by genetic or pharmacological techniques potentiated the protein levels of FoxO1, further promoting the activity of the PINK1/Parkin signaling pathway, thus augmenting mitophagy and exerting hepatoprotective effects upon I/R injury. In conclusion, the inhibition of XBP1 potentiated FoxO1-mediated mitophagy in hepatic I/R injury. Specific genetic and pharmacological treatment targeting XBP1 in the perioperative 6 h prior to reperfusion exerted beneficial effects, thus providing a novel therapeutic approach.

7.
Molecules ; 29(3)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38338428

RESUMEN

In order to efficiently extract ß-glucan from highland barley (HBG) and study its structural characterization and antioxidant activity, ultrasonic-microwave-assisted extraction (UME) was optimized by the response surface method (RSM). Under the optimal extraction conditions of 25.05 mL/g liquid-solid ratio, 20 min ultrasonic time, and 480 W microwave intensity, the DPPH radical scavenging activity of HBG reached 25.67%. Two polysaccharide fractions were purified from HBG, namely HBG-1 and HBG-2. Structural characterization indicated that HBG-1 and HBG-2 had similar functional groups, glycosidic linkages, and linear and complex chain conformation. HBG-1 was mainly composed of glucose (98.97%), while HBG-2 primarily consisted of arabinose (38.23%), galactose (22.01%), and xylose (31.60%). The molecular weight of HBG-1 was much smaller than that of HBG-2. Both HBG-1 and HBG-2 exhibited concentration-dependent antioxidant activity, and HBG-1 was more active. This study provided insights into the efficient extraction of HBG and further investigated the structure and antioxidant activities of purified components HBG-1 and HBG-2. Meanwhile, the results of this study imply that HBG has the potential to be an antioxidant in foods and cosmetics.


Asunto(s)
Hordeum , beta-Glucanos , Antioxidantes/farmacología , Antioxidantes/química , Ultrasonido , Microondas , beta-Glucanos/farmacología , Polisacáridos/química
8.
Heliyon ; 10(2): e24499, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38298727

RESUMEN

The study aimed to explore the relationship between the expression of cytochrome P450 family 27 subfamily B member 1 (CYP27B1), vitamin D, and impaired T cell subsets in recurrent spontaneous miscarriage (RSM). A Total of 779 healthy women of childbearing age and 1031 women with a history of RSM were involved in this study. The results of flow cytometry showed that the proportion of Tregs was higher in healthy women than in the women with RSM. For cytokines, the levels of interleukin-17 (IL-17) and interferon-gamma (IFN-γ) were significantly higher in RSM patients than in healthy women, while IL-10 was notably lower in RSM patients. Furthermore, compared to healthy individuals, RSM patients had lower levels of serum 25(OH)D detected by chemiluminescence. The frequency of Tregs was negatively correlated with 25(OH)D. Specifically, for every 10 ng/ml increase in 25(OH)D, the percentage of Tregs increased by 0.58 as calculated. IL-17 and IFN-γ were inversely correlated with 25(OH)D, while the serum interleukin-10 (IL-10) level was positively correlated with 25(OH)D. CYP27B1 was found to be expressed in both cytotrophoblast and extracellular villi trophoblast cells. However, reduced expression of CYP27B1 was observed in the placenta with RSM. Notably, the level of 25(OH)D increased in the supernatant of CYP27B1 knockdown BeWo compared to normal cells, while human chorionic gonadotropin (hCG) was significantly reduced. The hCG secretion of CYP27B1 KO BeWo cells was partially restored after 1,25(OH)2D3 supplementation. In addition, 1,25(OH)2D3 treatment could induce more CD4+ T cells to convert to Foxp3+iTreg, which in turn inhibited the secretion of IL-17, IFN-γ. In summary, this research unveiled a connection between reduced CYP27B1 and vitamin D deficiency in RSM. Our study underscores the potential benefits of vitamin D treatment supplementation in the context of RSM. However, it is important to note that further research is imperative to validate these observations.

9.
Ecol Lett ; 27(1): e14364, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38225803

RESUMEN

Plant-soil feedback (PSF) is an important mechanism determining plant community dynamics and structure. Understanding the geographic patterns and drivers of PSF is essential for understanding the mechanisms underlying geographic plant diversity patterns. We compiled a large dataset containing 5969 observations of PSF from 202 studies to demonstrate the global patterns and drivers of PSF for woody and non-woody species. Overall, PSF was negative on average and was influenced by plant attributes and environmental settings. Woody species PSFs did not vary with latitude, but non-woody PSFs were more negative at higher latitudes. PSF was consistently more positive with increasing aridity for both woody and non-woody species, likely due to increased mutualistic microbes relative to soil-borne pathogens. These findings were consistent between field and greenhouse experiments, suggesting that PSF variation can be driven by soil legacies from climates. Our findings call for caution to use PSF as an explanation of the latitudinal diversity gradient and highlight that aridity can influence plant community dynamics and structure across broad scales through mediating plant-soil microbe interactions.


Asunto(s)
Plantas , Suelo , Microbiología del Suelo , Simbiosis , Retroalimentación
10.
Sci China Life Sci ; 67(4): 817-828, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38217639

RESUMEN

The Convention on Biological Diversity seeks to conserve at least 30% of global land and water areas by 2030, which is a challenge but also an opportunity to better preserve biodiversity, including flowering plants (angiosperms). Herein, we compiled a large database on distributions of over 300,000 angiosperm species and the key functional traits of 67,024 species. Using this database, we constructed biodiversity-environment models to predict global patterns of taxonomic, phylogenetic, and functional diversity in terrestrial angiosperms and provide a comprehensive mapping of the three diversity facets. We further evaluated the current protection status of the biodiversity centers of these diversity facets. Our results showed that geographical patterns of the three facets of plant diversity exhibited substantial spatial mismatches and nonoverlapping conservation priorities. Idiosyncratic centers of functional diversity, particularly of herbaceous species, were primarily distributed in temperate regions and under weaker protection compared with other biodiversity centers of taxonomic and phylogenetic facets. Our global assessment of multifaceted biodiversity patterns and centers highlights the insufficiency and unbalanced conservation among the three diversity facets and the two growth forms (woody vs. herbaceous), thus providing directions for guiding the future conservation of global plant diversity.


Asunto(s)
Magnoliopsida , Filogenia , Biodiversidad , Plantas , Ecosistema , Conservación de los Recursos Naturales
11.
Cancer Treat Res Commun ; 38: 100786, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38198984

RESUMEN

OBJECTIVES: The incidence of cervical cancer increases every year during pregnancy. Cervical cytology in pregnant women has a unique morphology and liquid-based cytology methods are prone to cause false positives. The aim of this study was to investigate the serum cytokeratin 19 fragment antigen 21-1 (CYFRA21-1) and squamous cell carcinoma associated antigen (SCC-Ag) concentrations in healthy pregnant women during pregnancy and to assess their diagnostic value for cervical cancer in pregnancy. METHODS: In this prospective study, 165 healthy non-pregnant women, 441 healthy pregnant women and 22 patients with cervical cancer in pregnancy were recruited. The healthy pregnant women group included 143 women in the first trimester (T1), 147 in the second (T2) and 151 in the third (T3). RESULTS: Both SCC-Ag and CYFRA21-1 levels were significantly different in the healthy pregnant women group compared to the control group. The CYFRA21-1 and SCC-Ag were higher in the T1 and T3 than in the control groups. However, there was no statistically significant difference in serum CYFRA21-1 and SCC-Ag levels in the T2 group compared to the control group. The AUCs of CYFRA21-1, SCC-Ag and CYFRA21-1 combined with SCC-Ag were 0.674, 0.792, and 0.805, respectively. The cut-off values of CYFRA21-1 and SCC-Ag were 6.64 ng/mL and 1.75 ng/mL, respectively. CONCLUSIONS: Serum CYFRA21-1 and SCC-Ag levels were higher in pregnant women during early and late pregnancy compared to non-pregnant individuals, while they were not statistically different from non-pregnant women during mid-trimester. CYFRA21-1 and SCC-Ag have diagnostic value for cervical cancer in pregnancy.


Asunto(s)
Antígenos de Neoplasias , Carcinoma de Células Escamosas , Serpinas , Neoplasias del Cuello Uterino , Humanos , Femenino , Embarazo , Queratina-19 , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patología , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/patología , Estudios Prospectivos
12.
Asia Pac J Clin Oncol ; 20(2): 319-322, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36658669

RESUMEN

About 80% of hepatocellular carcinoma (HCC) patients are in advanced stages and ineligible for curative surgery. Palliative treatments just maintained limited survival, thus an effective downstaging therapy is badly needed. Here we report an initially unresectable patient who underwent radical hepatectomy after successful downstaging with selective internal radiation therapy (SIRT). A 34-year-old man was diagnosed with China Liver Cancer Staging (CNLC) IIIa HCC. Due to insufficient future liver remnant and vascular involvement, the patient was suggested to be unresectable. SIRT with yttrium-90 resin microspheres was given. At three months post-SIRT, a complete response was achieved. The tumor was downstaged to CNLC Ia stage. The patient underwent anatomical hepatectomy 5 months after SIRT. Histopathological examination of the resected specimen showed 4% viable tumor cells inside a necrotic mass. To our knowledge, this is the first case who underwent SIRT with yttrium-90 resin microspheres in China mainland. The success of the downstaging in this case renders a possible cure to be achieved in an initially unresectable patient. In addition, the nearly complete tumor necrosis in the resected specimen indicates a good prognosis post-surgery. This is the first case who underwent SIRT with yttrium-90 resin microspheres in China mainland. SIRT followed by anatomical hepatectomy is a potentially curative strategy for unresectable HCC, which deserves a confirmative trial in the future.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Masculino , Humanos , Adulto , Carcinoma Hepatocelular/radioterapia , Carcinoma Hepatocelular/cirugía , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/cirugía , Neoplasias Hepáticas/patología , Hepatectomía , Microesferas , Radioisótopos de Itrio/uso terapéutico
13.
Gene ; 895: 147978, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-37951372

RESUMEN

The key circadian genes, Period1(Per1), Period2(Per2), and Period3(Per3), constitute the mammalian Period gene family. The abnormal expression of Per1 and Per2 is closely related to tumor development, but there are few reports on Per3 and tumorigenesis. This study was conducted to determine whether the abnormal expression of Per3 could influence the progression of astroblastoma. The results indicated that the expression level of Per3 was increased in astroblastoma cells, and the high expression of Per3 was correlated with the poor overall survival time of glioma patients. The role of Per3 in astroblastoma cells was then investigated using two approaches: interference and overexpression. The interference of Per3 inhibited astroblastoma cell proliferation by inducing the cell cycle at the S phase. The interference of Per3 inhibited the migration and invasion of astroblastoma cells, while promoted the astroblastoma cell apoptosis and the expression of the apoptosis genes Cleaved-CASP3, P53, and BAX. The overexpression of Per3 promoted proliferation by affecting the S phase distribution of the astroblastoma cell cycle. The overexpression of Per3 promoted the migration and invasion of astroblastoma cells, while inhibited the astroblastoma cell apoptosis and the expression of apoptosis genes Cleaved-CASP3, P53, and BAX. RNA-seq analysis showed that the interference of Per3 in astrocytoma cells resulted in significant changes in the expression levels of 764 genes. Among the differentially expressed genes enriched in apoptosis-related pathways, the interference of Per3 resulted in significant upregulation of MARCKSL1 expression, in contrast to significant downregulation of SFRP4, EPB41L3, and GPC5 expression. Taken together, our results suggest that Per3 appears to be a pro-cancer gene by altering the proliferation, migration, invasion, and apoptosis of astroblastoma cells. As a result, the Per3 gene may be a promising therapeutic target in the treatment of astroblastoma.


Asunto(s)
Neoplasias Neuroepiteliales , Proteína p53 Supresora de Tumor , Animales , Humanos , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo , Caspasa 3/metabolismo , Ritmo Circadiano , Glipicanos/metabolismo , Mamíferos/metabolismo , Proteínas de Microfilamentos/metabolismo , Neoplasias Neuroepiteliales/genética , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteína p53 Supresora de Tumor/genética
14.
Sci China Life Sci ; 67(2): 403-413, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37606847

RESUMEN

Global climate change has led to the decline of species and functional diversity in ecosystems, changing community composition and ecosystem functions. However, we still know little about how species with different resource-use strategies (different types of resource usage and plant growth of plants as indicated by the spectrum of plant economic traits, including acquisitive resource-use strategy and conservative resource-use strategy) would change in response to climate change, and how the changes in the diversity of species with different resource-use strategies may influence community-level productivity. Here, using long-term (1982-2017) observatory data in a temperate grassland in Inner Mongolia, we investigated how climate change had affected the species richness (SR) and functional richness (FRic) for the whole community and for species with different resource-use strategies. Specifically, based on data for four traits representing leaf economics spectrum (leaf carbon concentration, leaf nitrogen concentration, leaf phosphorus concentration, and specific leaf area), we divided 81 plant species appearing in the grassland community into three plant functional types representing resource-acquisitive, medium, and resource-conservative species. We then analyzed the changes in community-level productivity in response to the decline of SR and FRic at the community level and for different resource-use strategies. We found that community-level SR and FRic decreased with drying climate, which was largely driven by the decline of diversity for resource-acquisitive species. However, community-level productivity remained stable because resource-conservative species dominating this grassland were barely affected by climate change. Our study revealed distinctive responses of species with different resource-use strategies to climate change and provided a new approach based on species functional traits for predicting the magnitude and direction of climate change effects on ecosystem functions.


Asunto(s)
Ecosistema , Pradera , Cambio Climático , Plantas , China , Biodiversidad
15.
Int J Gynaecol Obstet ; 165(2): 786-791, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37994047

RESUMEN

OBJECTIVE: To assess whether serum inhibin A at 14-20 weeks of gestation is associated with the occurrence of pre-eclampsia. METHODS: A retrospective cohort study using propensity score matching was conducted on 11 682 singleton pregnant women with established deliveries at the Obstetrics and Gynecology Hospital of Fudan University between January 2017 and July 2019. We investigated serum inhibin A levels at 14-20 weeks of gestation and calculated the relative risk between inhibin A and pre-eclampsia by multifactorial logistic regression analysis. Smoothed, fitted curves were used to observe the effect of inhibin A in relation to the occurrence of pre-eclampsia. RESULTS: The risk of pre-eclampsia occurrence increased with elevated serum inhibin A. After full adjustment for confounders, the risk ratio for pre-eclampsia in the group of pregnant women with high inhibin A was 2.92 (95% confidence interval [CI] 2.08-4.11) compared with those with normal inhibin A. The results of sensitivity analysis suggested a consistent effect of inhibin A on the risk of pre-eclampsia in different populations. CONCLUSION: Elevated serum inhibin A at 14-20 weeks of gestation is associated with pre-eclampsia and may provide an early warning signal for pregnancy outcomes associated with pre-eclampsia.


Asunto(s)
Preeclampsia , Embarazo , Femenino , Humanos , Preeclampsia/epidemiología , Estudios Retrospectivos , Puntaje de Propensión , Inhibinas
16.
Org Lett ; 25(48): 8766-8770, 2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-37991932

RESUMEN

Two C1-symmetric heterohelicenes were constructed by nonsymmetrically extending the ortho-fused structures of a C2v-symmetric NBN-embedded phenalene derivative and featured intense luminescence, large Stokes shifts, and successive reversible redox behaviors. Increasing one fused phenyl unit in such a helical structure led to a 10-fold-enhanced dissymmetry factor. Their strong double hydrogen-bond-donating capability makes them distinctly red-shifted in absorption, emission, and CD and CPL spectra upon the addition of fluoride anion.

17.
Nat Commun ; 14(1): 7609, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37993449

RESUMEN

The rapid diversification and high species richness of flowering plants is regarded as 'Darwin's second abominable mystery'. Today the global spatiotemporal pattern of plant diversification remains elusive. Using a newly generated genus-level phylogeny and global distribution data for 14,244 flowering plant genera, we describe the diversification dynamics of angiosperms through space and time. Our analyses show that diversification rates increased throughout the early Cretaceous and then slightly decreased or remained mostly stable until the end of the Cretaceous-Paleogene mass extinction event 66 million years ago. After that, diversification rates increased again towards the present. Younger genera with high diversification rates dominate temperate and dryland regions, whereas old genera with low diversification dominate the tropics. This leads to a negative correlation between spatial patterns of diversification and genus diversity. Our findings suggest that global changes since the Cenozoic shaped the patterns of flowering plant diversity and support an emerging consensus that diversification rates are higher outside the tropics.


Asunto(s)
Magnoliopsida , Magnoliopsida/genética , Filogenia , Plantas , Extinción Biológica , Evolución Biológica
18.
Proc Biol Sci ; 290(2011): 20231926, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37989241

RESUMEN

The evolution of dispersal modes has been proposed to promote the diversification of angiosperms. However, little is known about the relative impact of different dispersal modes on plant diversification. We test the association between dispersal modes and diversification rates using Rhamnaceae, the cosmopolitan buckthorn family, as a model. We found that species with diplochory have the highest diversification rates followed by those with myrmecochory and ballistic dispersal, while lineages dispersed by vertebrates and wind have relatively low diversification rates. The difference in diversification rates may be closely linked to the difference in dispersal distance and ecological interactions implied by each dispersal mode. Species which disperse over larger geographical distances may have much higher speciation rates due to the increased chance of establishing isolated populations due to geological barriers or habitat fragmentation. However, long-distance dispersal may also increase the chance of extinction. By contrast, species with short-distance dispersal modes may have low speciation rates. Complex interactions with the surrounding environment may, however, impact diversification rates positively by increasing plant survival and reproductive success.


Asunto(s)
Magnoliopsida , Rhamnaceae , Animales , Filogenia , Ecosistema , Geografía , Especiación Genética
19.
Micromachines (Basel) ; 14(10)2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37893385

RESUMEN

A GaN high-electron-mobility transistor (HEMT) was simulated using the semiconductor simulation software Silvaco TCAD in this paper. By constructing a two-dimensional structure of GaN HEMT, combined with key models such as carrier mobility, the effects of a different state, different incidence position, different drain voltage, different LET values, and a different incidence angle on the single-event transient effect of GaN HEMT are simulated. LET stands for the linear energy transfer capacity of a particle, which refers to the amount of energy transferred by the particle to the irradiated substance on the unit path. The simulation results show that for GaN HEMTs, the single-event transient effect is more obvious when the device is in off-state than in on-state. The most sensitive location of GaN HEMTs to the single-event effect is in the region near the drain. The peak transient current increases with the increase in the drain bias and incident ion LET values. The drain charge collection time increases with the angle of incidence of heavy ion.

20.
Conserv Biol ; : e14205, 2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37855155

RESUMEN

The Kunming-Montreal Global Biodiversity Framework of the Convention on Biological Diversity calls for an expansion of the current protected areas (PAs) to cover at least 30% of global land and water areas by 2030 (i.e., the 30×30 target). Efficient spatial planning for PA expansion is an urgent need for global conservation practice. A spatial prioritization framework considering multiple dimensions of biodiversity is critical for improving the efficiency of the spatial planning of PAs, yet it remains a challenge. We developed an index for the identification of priority areas based on functionally rare, evolutionarily distinct, and globally endangered species (FREDGE) and applied it to 21,536 terrestrial vertebrates. We determined species distributions, conservation status (global endangerment), molecular phylogenies (evolutionary distinctiveness), and life-history traits (functional rarity). Madagascar, Central America, and the Andes were of high priority for the conservation of multiple dimensions of terrestrial vertebrate biodiversity. However, 68.8% of grid cells in these priority areas had <17% of their area covered by PAs, and these priority areas were under intense anthropogenic and climate change threats. These results highlight the difficulties of conserving multiple dimensions of biodiversity. Our global analyses of the geographical patterns of multiple dimensions of terrestrial vertebrate biodiversity demonstrate the insufficiency of the conservation of different biodiversity dimensions, and our index, based on multiple dimensions of biodiversity, provides a useful tool for guiding future spatial prioritization of PA expansion to achieve the 30×30 target under serious pressures.


+Identificación de las prioridades mundiales de conservación para los vertebrados terrestres con base en varias dimensiones de la biodiversidad Resumen El Marco Mundial de Biodiversidad de Kunming-Montreal del Convenio sobre Diversidad Biológica demanda la expansión de las áreas protegidas actuales (AP) para que cubran al menos el 30% de las áreas marinas y terrestres para el 2030 (el objetivo 30×30). La conservación mundial necesita con urgencia de la planeación espacial eficiente para que la expansión de las AP. Es importante tener un marco de priorización espacial que considere varias dimensiones de la biodiversidad para mejorar la eficiencia de la planeación espacial de las AP, sin embargo, esto todavía es un reto. Desarrollamos un índice para identificar las áreas prioritarias con base en las especies funcionalmente raras, evolutivamente distintas y en peligro mundial (FREDGE, en inglés). Aplicamos este índice a 21,536 especies de vertebrados terrestres y determinamos su distribución, estado de conservación (peligro mundial), filogenia molecular (singularidad evolutiva) y características de la historia de vida (rareza funcional). Madagascar, América Central y los Andes representaron una gran prioridad para la conservación de varias dimensiones de la biodiversidad de vertebrados terrestres. Sin embargo, el 68.8% de las celdas de la cuadrícula en estas áreas prioritarias tuvieron <17% de su área cubierta por AP, y estas áreas prioritarias estaban sometidas a amenazas intensas de origen antropogénicas y de cambio climático. Estos resultados resaltan las dificultades de conservar las diferentes dimensiones de la biodiversidad. Nuestro análisis mundial de los patrones geográficos de las diferentes dimensiones de la biodiversidad de vertebrados terrestres demuestra la insuficiencia de la conservación de diferentes dimensiones de la biodiversidad y nuestro índice basado en varias dimensiones de la biodiversidad proporciona una herramienta útil para orientar en el futuro la priorización espacial de la expansión de AP para lograr el objetivo 30×30 bajo presión severa.

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