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1.
Cell ; 143(5): 711-24, 2010 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-21074248

RESUMEN

PI3K and PTEN lipid phosphatase control the level of cellular phosphatidylinositol (3,4,5)-trisphosphate, an activator of AKT kinases that promotes cell growth and survival. Mutations activating AKT are commonly observed in human cancers. We report here that ENTPD5, an endoplasmic reticulum (ER) enzyme, is upregulated in cell lines and primary human tumor samples with active AKT. ENTPD5 hydrolyzes UDP to UMP to promote protein N-glycosylation and folding in ER. Knockdown of ENTPD5 in PTEN null cells causes ER stress and loss of growth factor receptors. ENTPD5, together with cytidine monophosphate kinase-1 and adenylate kinase-1, constitute an ATP hydrolysis cycle that converts ATP to AMP, resulting in a compensatory increase in aerobic glycolysis known as the Warburg effect. The growth of PTEN null cells is inhibited both in vitro and in mouse xenograft tumor models. ENTPD5 is therefore an integral part of the PI3K/PTEN regulatory loop and a potential target for anticancer therapy.


Asunto(s)
Proliferación Celular , Retículo Endoplásmico/metabolismo , Glicosilación , Proteínas Oncogénicas/metabolismo , Adenosina Trifosfato/metabolismo , Aerobiosis , Animales , Línea Celular Tumoral , Glucólisis , Guanosina Monofosfato/metabolismo , Humanos , Ratones , Trasplante de Neoplasias , Proteína Oncogénica v-akt/metabolismo , Proteínas Oncogénicas/genética , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Pirofosfatasas , Trasplante Heterólogo , Uridina Monofosfato/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(46): e2212406119, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36346846

RESUMEN

Defense against ultraviolet (UV) radiation exposure is essential for survival, especially in high-elevation species. Although some specific genes involved in UV response have been reported, the full view of UV defense mechanisms remains largely unexplored. Herein, we used integrated approaches to analyze UV responses in the highest-elevation frog, Nanorana parkeri. We show less damage and more efficient antioxidant activity in skin of this frog than those of its lower-elevation relatives after UV exposure. We also reveal genes related to UV defense and a corresponding temporal expression pattern in N. parkeri. Genomic and metabolomic analysis along with large-scale transcriptomic profiling revealed a time-dependent coordinated defense mechanism in N. parkeri. We also identified several microRNAs that play important regulatory roles, especially in decreasing the expression levels of cell cycle genes. Moreover, multiple defense genes (i.e., TYR for melanogenesis) exhibit positive selection with function-enhancing substitutions. Thus, both expression shifts and gene mutations contribute to UV adaptation in N. parkeri. Our work demonstrates a genetic framework for evolution of UV defense in a natural environment.


Asunto(s)
Anuros , Rayos Ultravioleta , Animales , Anuros/genética , Piel , Perfilación de la Expresión Génica , Antioxidantes
3.
J Cell Biochem ; 125(1): 100-114, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38031891

RESUMEN

Osteoporosis (OP) is a bone remodeling disease characterized by an imbalance between bone resorption and formation. Osteoclasts are the primary therapeutic targets for treating bone destruction. Koumine (KM), the most bioactive component in Gelsemium alkaloids, exhibits antitumor, immunosuppressive, anti-inflammatory, and analgesic properties. However, the effects of bone loss have not been well studied. This study conducted in vitro and in vivo verification experiments on KM. The results showed that KM inhibited bone resorption and tartrate-resistant acid phosphatase positive (TRAP+) osteoclasts development by mature osteoclasts in a dose-dependent manner. Moreover, KM prevented OVX-induced OP in vivo and potentially inhibited ubiquitination, a process closely related to various biological activities, including protein interaction, transcription, and transmembrane signal transduction regulation, especially within the nuclear factor-κB (NF-κB) pathway. Previous studies have demonstrated that several proteins ubiquitination promotes osteoclastogenesis, our study indicated that KM inhibits early NF-κB activation and receptor activator of NF-κB ligand induced ubiquitination, a critical factor in osteoclast differentiation. In conclusion, our research suggests that KM holds potential as an effective therapeutic agent for OP.


Asunto(s)
Resorción Ósea , Alcaloides Indólicos , Osteoporosis , Femenino , Humanos , FN-kappa B/metabolismo , Osteoclastos/metabolismo , Osteogénesis , Resorción Ósea/tratamiento farmacológico , Resorción Ósea/prevención & control , Resorción Ósea/metabolismo , Osteoporosis/tratamiento farmacológico , Osteoporosis/etiología , Osteoporosis/prevención & control , Ovariectomía/efectos adversos , Ligando RANK/metabolismo , Diferenciación Celular
4.
PLoS Pathog ; 18(7): e1010632, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35789345

RESUMEN

Enteroviruses (EVs) are among the most prevalent viruses worldwide. They are characterized by a high genetic and phenotypic diversity, being able to cause a plethora of symptoms. EV-D68, a respiratory EV, and EV-D94, an enteric EV, represent an interesting paradigm of EV tropism heterogeneity. They belong to the same species, but display distinct phenotypic characteristics and in vivo tropism. Here, we used these two viruses as well as relevant 3D respiratory, intestinal and neural tissue culture models, to highlight key distinctive features of enteric and respiratory EVs. We emphasize the critical role of temperature in restricting EV-D68 tissue tropism. Using transcriptomic analysis, we underscore fundamental differences between intestinal and respiratory tissues, both in the steady-state and in response to infection. Intestinal tissues present higher cell proliferation rate and are more immunotolerant than respiratory tissues. Importantly, we highlight the different strategies applied by EV-D94 and EV-D68 towards the host antiviral response of intestinal and respiratory tissues. EV-D68 strongly activates antiviral pathways while EV-D94, on the contrary, barely induces any host defense mechanisms. In summary, our study provides an insightful characterization of the differential pathogenesis of EV-D68 and EV-D94 and the interplay with their main target tissues.


Asunto(s)
Enterovirus Humano D , Infecciones por Enterovirus , Enterovirus , Infecciones del Sistema Respiratorio , Antígenos Virales , Antivirales , Enterovirus Humano D/fisiología , Humanos , Tropismo
5.
Opt Express ; 32(12): 20931-20947, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38859461

RESUMEN

In recent decades, rapid advances in astronomical imaging campaigns have generated an urgent need for detailed spectroscopic surveys with increased speed and efficiency. The 6.5 m MUltiplexed Survey Telescope (MUST) aims to address these current demands. The performance of the multi-object fiber-fed spectrograph (MOFS) plays a critical role for spectroscopic survey telescopes, directly influencing the realization of scientific aims. In this paper, we demonstrate a high-resolution and highly-multiplexed option for MOFS of MUST. The system is believed to be first to apply a 92 mm × 92 mm large-size detector in a Schmidt-like camera and reduces the average central obscuration to 14%. Thanks to the F/1.25 camera design with excellent image quality, the spectrograph achieves up to 800 150µm-large-core optical fibers integration. It can obtain the broadband spectral information (395 nm-435 nm, 520 nm-570 nm, 610 nm-680 nm) of 800 objects with a high resolution of >16,000 within one exposure. The spectrograph theory, design method, and final system scheme of the MOFS can offer good reference and guidance for the spectrograph design in the spectroscopic survey.

6.
Chemistry ; 30(13): e202303394, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38116992

RESUMEN

The development of efficient and selective organic synthetic approaches for complex molecules has garnered significant attention due to the need for precise control over molecular structures and functions. Rotaxanes, a type of mechanically interlocked molecules (MIMs), have shown promising applications in various fields including sensing, catalysis, and material science. However, the highly selective synthesis of oligo[n]rotaxanes (mostly n≥3) through controlling host-guest complexation and supramolecular threading assembly process still remains an ongoing challenge. In particular, the utilization of two-dimensional (2D) macrocycles with structural shape-persistency for the synthesis of oligo[n]rotaxanes is rare. In this concept, research on cooperatively threaded host-guest complexation with hydrogen-bonded (H-bonded) aramide macrocycles and selective synthetic protocols of oligo[n]rotaxanes has been summarized. The high efficiency and selectivity in synthesis are ascribed to the synergistic interplay of multiple non-covalent bonding interactions such as hydrogen bonding and intermolecular π-π stacking of macrocycles within the unique supramolecular structure of threaded host-guest complexes. This review focuses on the latest progress in the concepts, synthesis, and properties of H-bonded aramide macrocycle-based oligorotaxanes, and presents an in-depth outlook on challenges in this emerging field.

7.
Virol J ; 21(1): 78, 2024 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-38566231

RESUMEN

Chronic obstructive pulmonary disease (COPD) affects over 250 million individuals globally and stands as the third leading cause of mortality. Respiratory viral infections serve as the primary drivers of acute exacerbations, hastening the decline in lung function and worsening the prognosis. Notably, Human Parainfluenza Virus type 3 (HPIV-3) is responsible for COPD exacerbations with a frequency comparable to that of Respiratory Syncytial Virus and Influenza viruses. However, the impact of HPIV-3 on respiratory epithelium within the context of COPD remains uncharacterized.In this study, we employed in vitro reconstitution of lower airway epithelia from lung tissues sourced from healthy donors (n = 4) and COPD patients (n = 5), maintained under air-liquid interface conditions. Through a next-generation sequencing-based transcriptome analysis, we compared the cellular response to HPIV-3 infection.Prior to infection, COPD respiratory epithelia exhibited a pro-inflammatory profile, notably enriched in canonical pathways linked to antiviral response, B cell signaling, IL-17 signaling, and epithelial-mesenchymal transition, in contrast to non-COPD epithelia. Intriguingly, post HPIV-3 infection, only non-COPD epithelia exhibited significant enrichment in interferon signaling, pattern recognition receptors of viruses and bacteria, and other pathways involved in antiviral responses. This deficiency could potentially hinder immune cell recruitment essential for controlling viral infections, thus fostering prolonged viral presence and persistent inflammation.


Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica , Virus Sincitial Respiratorio Humano , Virosis , Virus , Humanos , Virus de la Parainfluenza 3 Humana , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Epitelio , Antivirales/uso terapéutico
8.
BMC Womens Health ; 24(1): 315, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38824522

RESUMEN

BACKGROUND: Sleep health and obesity may affect the risk of female infertility. However, few studies focused on the interaction of obesity and sleep health on the female infertility risk. This study aimed to evaluate the combined impact of trouble sleeping / sleep duration and overweight/obesity/ abdominal obesity on the risk of female infertility. METHODS: The data for this cross-sectional study was obtained from National Health and Nutritional Examination Survey, which provided information on trouble sleeping, sleep duration, overweight/obesity, abdominal obesity, and confounding factors. Adopted weighted univariate and multivariate logistic regression models to explore the relationship between trouble sleeping, sleep duration, overweight/obesity, abdominal obesity, and the risk of infertility, respectively, and the combined effect of trouble sleeping and overweight/obesity, trouble sleeping and abdominal obesity, sleep duration and overweight/obesity, sleep duration and abdominal obesity, on the female infertility risk. RESULTS: This study included a total of 1,577 women, and 191 were diagnosed with infertility. Women with infertility had a higher proportion of people with overweight/obesity, abdominal obesity, sleep duration ≤ 7 h and trouble sleeping than those with non-infertility. The result indicated that trouble sleeping [odds ratio (OR) = 2.25, 95% confidence intervals (CI): 1.49-3.39], sleep duration ≤ 7 h (OR = 1.59, 95% CI: 1.03-2.48), and the combined impact of abdominal obesity and trouble sleeping (OR = 2.18, 95% CI: 1.28-3.72), abdominal obesity and sleep duration ≤ 7 h (OR = 2.00, 95% CI: 1.17-3.40), overweight/obesity and trouble sleeping (OR = 2.29, 95% CI: 1.24-4.26), and overweight/obesity and sleep duration ≤ 7 h (OR = 1.88, 95% CI: 1.01-3.49) were associated with increased odds of infertility, respectively. CONCLUSION: There was combined effects of trouble sleeping/sleep duration ≤ 7 h and overweight/obesity/ abdominal obesity on increased odds of female infertility.


Asunto(s)
Infertilidad Femenina , Encuestas Nutricionales , Obesidad Abdominal , Obesidad , Trastornos del Sueño-Vigilia , Humanos , Femenino , Adulto , Infertilidad Femenina/epidemiología , Infertilidad Femenina/etiología , Estudios Transversales , Obesidad/epidemiología , Obesidad/complicaciones , Obesidad Abdominal/epidemiología , Obesidad Abdominal/complicaciones , Trastornos del Sueño-Vigilia/epidemiología , Trastornos del Sueño-Vigilia/complicaciones , Sueño/fisiología , Sobrepeso/epidemiología , Sobrepeso/complicaciones , Factores de Riesgo , Adulto Joven , Estados Unidos/epidemiología
9.
Appl Opt ; 63(16): 4284-4292, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38856604

RESUMEN

The development of modern large-scale spectroscopic survey telescopes responds to the urgent demand for spectral information in astronomical research. Tsinghua University has previously proposed a 6.5 m MUltiplexed Survey Telescope consisting of a Ritchey-Chretien configuration and a 1.8 m multi-element wide-field corrector, achieving excellent performance and world-leading survey efficiency. However, an optimized 1.65 m multi-element corrector with five lenses is proposed to overcome the constraints on glass uniformity and verification in fabrication of the previous corrector design. It maintains outstanding image quality, with the 80% enclosed energy diameter not more than 0.559 arcsec within 3° FoV over up to a 55° zenith angle. The optimized optical system does not revise the working mode of the ADC or the curvature of the primary mirror while ensuring the reasonability and accuracy of manufacturing of large corrector elements. It provides a more feasible reference optical design for the MUltiplexed Survey Telescope in subsequent iterations and communications with manufacturers.

10.
Appl Opt ; 63(9): 2187-2194, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38568571

RESUMEN

We designed a cascaded all-soft-glass fiber structure and simulate midinfrared 2-20 µm ultrawideband supercontinuum (SC) generation numerically. The cascaded fiber structure consists of a 1.5 m I n F 3 fiber, a 0.2 m chalcogenide photonic crystal fiber, and a 0.2 m tellurium-based chalcogenide photonic crystal fiber. Using a 2 µm pulse pumping this cascaded structure, the generated SC covering the wavelengths longer than 20 µm has been demonstrated theoretically. The 30 dB bandwidth reaches 20.87 µm from 1.44 to 22.31 µm. The effect of different pulse widths on SC generation is considered. With the increase of peak power and the decrease of pulse width, the energy of SC in the 15-20 µm waveband increases gradually. The mechanism of SC broadening process has also been analyzed. The SC generation of more than 20 µm in this cascade structure is caused by the self-phase modulation, soliton effects, four-wave mixing, and redshifted dispersive wave. This method demonstrates the possibility of generating ultrawide bandwidth SCs up to a 20 µm waveband by a commercial 2 µm pump source and all-fiber structure.

11.
Lett Appl Microbiol ; 77(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38400571

RESUMEN

Intestinal microbiota is a potential determinant of obesity, with probiotic bile salt hydrolase (BSH) as one of the key mechanisms in the anti-obesity effects. In this study, we present a Lactobacillus acidophilus GOLDGUT-LA100 (LA100) with high BSH activity, good gastric acid and bile salt tolerance, and a potential anti-obesity effect. LA100's anti-obesity effects were evaluated in a high-fat diet-induced, obese mouse model. LA100 administration alleviates high-fat diet-induced pathophysiological symptoms, such as body weight gain, high serum glucose and cholesterol level, hepatic lipid accumulation, and adipose inflammation. These results demonstrate concrete anti-obesity benefit in animal models and show promising applications in future clinical studies.


Asunto(s)
Lactobacillus acidophilus , Probióticos , Ratones , Animales , Modelos Animales de Enfermedad , Obesidad , Probióticos/farmacología , Dieta Alta en Grasa , Ratones Endogámicos C57BL
12.
Lett Appl Microbiol ; 77(1)2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38242846

RESUMEN

The administration of probiotics is an effective approach for treatment of Helicobacter pylori, which is associated with human gastrointestinal diseases and cancers. To explore more effective probiotics for H. pylori infection elimination, bacteria from infant feces were screened in this study. We successfully isolated the Bifidobacterium animalis subsp. lactis strains and evaluated its efficacy to inhibit H. pylori growth in vitro and in vivo. The results showed that a B. animalis strain (named BB18) sustained a high survival rate after incubation in gastric juice. The rapid urease test suggested that B. animalis BB18 reduced pathogen loads in H. pylori-infected Mongolian gerbils. Alleviation of H. pylori infection-induced gastric mucosa damage and decreased levels inflammatory cytokines were observed after the B. animalis BB18 administration. These findings demonstrated that B. animalis BB18 can inhibit H. pylori infection both in vitro and in vivo, suggesting its potential application for the prevention and eradication therapy of H. pylori infection.


Asunto(s)
Bifidobacterium animalis , Infecciones por Helicobacter , Helicobacter pylori , Probióticos , Humanos , Bifidobacterium , Infecciones por Helicobacter/prevención & control , Citocinas
13.
J Formos Med Assoc ; 123(4): 496-500, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37903693

RESUMEN

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a novel disease associated with COVID-19. The COVID-19 epidemic peaked in May 2022 in Taiwan, and we encountered our first case of MIS-C in late May 2022. We aimed to present patients' clinical manifestations and identify risk factors for shock. METHODS: We included patients diagnosed with MIS-C at two medical centers from May 2022 to August 2022. We separated those patients into two groups according to whether they experienced shock. We collected demographic, clinical manifestation, and laboratory data of the patients and performed statistical analysis between the two groups. RESULTS: We enrolled 28 patients, including 13 (46 %) with shock and 15 (54 %) without shock. The median age was 6.4 years (IQR: 1.9-7.5). In single variable analysis, patients with shock tended to be older, had more neurological symptoms, more conjunctivitis and strawberry tongue, lower lymphocyte count, lower platelet counts, and higher C-reactive protein, higher procalcitonin, higher ferritin, and higher D-dimer levels than those without shock. The area under the ROC curve that used procalcitonin to be the risk factor of shock with MIS-C was 0.815 (95 % CI 0.644 to 0.987). The cutoff value obtained by ROC analysis of procalcitonin was 1.68 ng/mL. With this cutoff, the test characteristics of procalcitonin were as follows: sensitivity 77 %, specificity 93 %, positive predictive value 91 %, negative predictive value 82 %. Multivariable analysis revealed that procalcitonin was the only independent risk factor of shock with MIS-C on admission (OR, 26.00, 95 % CI, 1.01-668.89). CONCLUSIONS: MIS-C patients with high initial procalcitonin levels have higher risks of experiencing shock and may need ICU admission.


Asunto(s)
COVID-19 , COVID-19/complicaciones , Neumonía Viral , Síndrome de Respuesta Inflamatoria Sistémica , Niño , Humanos , Neumonía Viral/epidemiología , Polipéptido alfa Relacionado con Calcitonina , COVID-19/epidemiología , Proteína C-Reactiva/análisis , Estudios Retrospectivos
14.
Nat Immunol ; 12(8): 742-51, 2011 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-21725320

RESUMEN

The orphan nuclear receptor SHP (small heterodimer partner) is a transcriptional corepressor that regulates hepatic metabolic pathways. Here we identified a role for SHP as an intrinsic negative regulator of Toll-like receptor (TLR)-triggered inflammatory responses. SHP-deficient mice were more susceptible to endotoxin-induced sepsis. SHP had dual regulatory functions in a canonical transcription factor NF-κB signaling pathway, acting as both a repressor of transactivation of the NF-κB subunit p65 and an inhibitor of polyubiquitination of the adaptor TRAF6. SHP-mediated inhibition of signaling via the TLR was mimicked by macrophage-stimulating protein (MSP), a strong inducer of SHP expression, via an AMP-activated protein kinase-dependent signaling pathway. Our data identify a previously unrecognized role for SHP in the regulation of TLR signaling.


Asunto(s)
FN-kappa B/inmunología , Receptores Citoplasmáticos y Nucleares/inmunología , Sepsis/inmunología , Receptores Toll-Like/inmunología , Proteínas Quinasas Activadas por AMP/inmunología , Animales , Inmunoprecipitación de Cromatina , Femenino , Immunoblotting , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal , Factor 6 Asociado a Receptor de TNF/inmunología , Ubiquitinación/inmunología
15.
Mol Ecol ; 32(6): 1335-1350, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36073004

RESUMEN

Understanding how and why species evolve requires knowledge on intraspecific divergence. In this study, we examined intraspecific divergence in the endangered hot-spring snake (Thermophis baileyi), an endemic species on the Qinghai-Tibet Plateau (QTP). Whole-genome resequencing of 58 sampled individuals from 15 populations was performed to identify the drivers of intraspecific divergence and explore the potential roles of genes under selection. Our analyses resolved three groups, with major intergroup admixture occurring in regions of group contact. Divergence probably occurred during the Pleistocene as a result of glacial climatic oscillations, Yadong-Gulu rift, and geothermal fields differentiation, while complex gene flow between group pairs reflected a unique intraspecific divergence pattern on the QTP. Intergroup fixed loci involved selected genes functionally related to divergence and local adaptation, especially adaptation to hot spring microenvironments in different geothermal fields. Analysis of structural variants, genetic diversity, inbreeding, and genetic load indicated that the hot-spring snake population has declined to a low level with decreased diversity, which is important for the conservation management of this endangered species. Our study demonstrated that the integration of demographic history, gene flow, genomic divergence genes, and other information is necessary to distinguish the evolutionary processes involved in speciation.


Asunto(s)
Variación Genética , Manantiales de Aguas Termales , Humanos , Animales , Tibet , Variación Genética/genética , Filogenia , Uganda , Serpientes/genética , Genómica
16.
Opt Express ; 31(22): 36350-36358, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-38017789

RESUMEN

The entire decaying dynamics of harmonic mode-locking (HML) are studied utilizing the dispersive Fourier transform (DFT) technique in a SESAM-based mode-locked fiber laser. It is unveiled that the harmonic solitons do not disappear directly, but undergo transitional processes from the higher-order HML to the lower-order HML and then to the fundamental mode-locking (FML), and finally vanish. The "big corner" can also exist in the decaying process rather than just in the buildup process of HML, and there is at least one "big corner" during the decaying process between the consecutive multi-pulsing states. The energy stabilization phase (ESP) cannot be observed during every transitional process. A breathing behavior and a vibrating soliton molecule are observed in the decaying process from the 2nd HML to the FML and in the decaying process of the FML, respectively. Our work would enrich the understanding of HML behaviors and may contribute to the laser designs.

17.
Opt Lett ; 48(1): 53-56, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36563367

RESUMEN

We propose a Yb-doped fiber laser with an all-fiber beam shaper based on a single-mode-graded-index multimode-few-mode fiber (SMF-GIMF-FMF) structure. The excitation coefficients of the mode can be adjusted continuously by changing the GIMF length. Numerical simulations are performed to investigate the beam shaping dynamics in the fiber structure. Through adding the simple device geometry in the laser cavity, the switchable output between the fundamental transverse (LP01) mode and the second-order transverse (LP11) mode can be achieved. Cylindrical vector beams with high mode purity are also shown by removing the degeneracy of the LP11 mode.

18.
Opt Lett ; 48(21): 5503-5506, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37910688

RESUMEN

We have developed a temporal coupled-mode theory based on quasi-normal modes to investigate the chiroptical effects in parity-time (PT) symmetric metasurfaces. The PT symmetry enforces a different constraint for the direct scattering matrix and the coupling constants, which is verified by calculating the transmission spectra originating from the chiral quasi-bound states in the continuum. What's more, the scattering matrix can be analytically continued to the complex frequency plane. We find that the zero and pole singularities of the transmission coefficients and scattering matrix play an important role in the optical chirality. The pole singularities carry a quantized topological charge of -1. Our work paves the way for studying the enhanced optical chirality in non-Hermitian metasurfaces.

19.
Conserv Biol ; 37(6): e14155, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37551770

RESUMEN

Although numerous studies on the impacts of climate change on biodiversity have been published, only a handful are focused on the intraspecific level or consider population-level models (separate models per population). We endeavored to fill this knowledge gap relative to the Qinghai-Tibetan plateau (QTP) by combining species distribution modeling (SDMs) with population genetics (i.e., population-level models) and phylogenetic methods (i.e., phylogenetic tree reconstruction and phylogenetic diversity analyses). We applied our models to 11 endemic and widely distributed herpetofauna species inhabiting high elevations in the QTP. We aimed to determine the influence of environmental heterogeneity on species' responses to climate change, the magnitude of climate-change impacts on intraspecific diversity, and the relationship between species range loss and intraspecific diversity losses under 2 shared socioeconomic pathways (SSP245 and SSP585) and 3 future periods (2050s, 2070s, and 2090s). The effects of global climatic change were more pronounced at the intraspecific level (22% of haplotypes lost and 36% of populations lost) than the morphospecies level in the SSP585 climate change scenario. Maintenance of genetic diversity was in general determined by a combination of factors including range changes, species genetic structure, and the part of the range predicted to be lost. This is owing to the fact that the loss and survival of populations were observed in species irrespective of the predicted range changes (contraction or expansion). In the southeast (mountainous regions), climate change had less of an effect on range size (>100% in 3 species) than in central and northern QTP plateau regions (range size <100% in all species). This may be attributed to environmental heterogeneity, which provided pockets of suitable climate in the southeast, whereas ecosystems in the north and central regions were homogeneous. Generally, our results imply that mountainous regions with high environmental heterogeneity and high genetic diversity may buffer the adverse impacts of climate change on species distribution and intraspecific diversity. Therefore, genetic structure and characteristics of the ecosystem may be crucial for conservation under climate change.


Impactos del cambio climático sobre la diversidad de herpetofauna en la meseta Qinghai-Tíbet Región Aunque se han publicado numerosos estudios sobre los impactos del cambio climática en la biodiversidad, son muy pocos los que se enfocan en el nivel intraespecífico o que consideran modelos a nivel poblacional (modelos separados por población). Intentamos cerrar este vacío de conocimiento en relación con la meseta Qinghai-Tíbet (MQT) con la combinación entre modelos de distribución de especies (MDE) y genética poblacional (modelos a nivel poblacional) y métodos filogenéticos (reconstrucción de árboles filogenéticos y análisis de diversidad filogenética). Aplicamos nuestros modelos a once especies endémicas de herpetofauna con distribución amplia en las elevaciones más altas de la MQT. Nos planteamos determinar la influencia de la heterogeneidad de las especies sobre la respuesta de las especies al cambio climático, la magnitud de los impactos del cambio climático sobre la diversidad intraespecífica y la relación entre la pérdida de distribución de la especie y las pérdidas de diversidad intraespecífica bajo dos vías socioeconómicas (SSP245 y SSP585) y tres periodos del futuro (2050s, 2070s y 2090s). Los efectos del cambio climático global fueron más pronunciados a nivel intraespecífico (22% de pérdida en los haplotipos y 36% en las poblaciones) que al nivel morfoespecie en el escenario de cambio climático SSP585. El mantenimiento de la diversidad genética casi siempre estuvo determinado por una combinación de factores que incluyen cambios en la distribución, estructura genética de las especies y la parte de la distribución que se pronosticó se perdería. Esto se debe a que observamos la pérdida y supervivencia de las poblaciones sin importar los cambios pronosticados en la distribución (contracción o expansión). En las regiones montañosas del sureste, el cambio climático tuvo un efecto menor sobre la distribución (>100% en tres especies) comparado con las regiones de la meseta central y del norte de la MQT (distribución <100% en todas las especies). Esto puede atribuirse a la heterogeneidad ambiental, la cual proporciona recovecos de clima adecuado en el sureste, mientras que los ecosistemas en las regiones central y norte fueron homogéneos. De manera general, nuestros resultados implican que las regiones montañosas con una elevada heterogeneidad ambiental y una gran diversidad genética podrían reducir los impactos adversos del cambio climático sobre la distribución de las especies y la diversidad intraespecífica. Por lo tanto, la estructura genética y las características del ecosistema pueden ser cruciales para conservar bajo el cambio climático.


Asunto(s)
Cambio Climático , Ecosistema , Tibet , Filogenia , Conservación de los Recursos Naturales
20.
Eur J Nutr ; 62(2): 771-782, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36261730

RESUMEN

PURPOSE: Fruit intake is beneficial to several chronic diseases, but controversial in diabetes. We aimed to investigate prospectively the associations of whole fresh fruit intake with risk of incident type 2 diabetes (T2D) in subjects with different glucose regulation capacities. METHODS: The present study included 79,922 non-diabetic participants aged ≥ 40 years from an ongoing nationwide prospective cohort in China. Baseline fruit intake information was collected by a validated food frequency questionnaire. Plasma HbA1c, fasting and 2 h post-loading glucose levels were measured at both baseline and follow-up examinations. Cox proportional hazards models were used to calculate hazard ratio (HR) and 95% confidence intervals (CI) for incident diabetes among participants with normal glucose tolerance (NGT) and prediabetes, after adjusted for multiple confounders. Restricted cubic spline analysis was applied for dose-response relation. RESULTS: During a median 3.8-year follow-up, 5886 (7.36%) participants developed diabetes. Overall, we identified a linear and dose-dependent inverse association between dietary whole fresh fruit intake and risk of incident T2D. Each 100 g/d higher fruit intake was associated with 2.8% lower risk of diabetes (HR 0.972, 95%CI [0.949-0.996], P = 0.0217), majorly benefiting NGT subjects with 15.2% lower risk (HR 0.848, 95%CI [0.766-0.940], P = 0.0017), while not significant in prediabetes (HR 0.981, 95%CI 0.957-4.005, P = 0.1268). Similarly, the inverse association was present in normoglycemia individuals with a 48.6% lower risk of diabetes when consuming fruits > 7 times/week comparing to those < 1 time/week (HR 0.514, 95% CI [0.368-0.948]), but not in prediabetes (HR 0.883, 95% CI [0.762-1.023]). CONCLUSION: These findings suggest that higher frequency and amount of fresh fruit intake may protect against incident T2D, especially in NGT, but not in prediabetes, highlighting the dietary recommendation of higher fresh fruit consumption to prevent T2D in normoglycemia population.


Asunto(s)
Diabetes Mellitus Tipo 2 , Estado Prediabético , Humanos , Diabetes Mellitus Tipo 2/epidemiología , Frutas , Estudios Prospectivos , Incidencia , Glucosa , Factores de Riesgo
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