Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
Opt Express ; 32(7): 12763-12773, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38571106

RESUMEN

Terahertz (THz) microcavities have garnered considerable attention for their ability to localize and confine THz waves, allowing for strong coupling to remarkably enhance the light-matter interaction. These properties hold great promise for advancing THz science and technology, particularly for high-speed integrated THz chips where transient interaction between THz waves and matter is critical. However, experimental study of these transient time-domain processes requires high temporal and spatial resolution since these processes, such as THz strong coupling, occur in several picoseconds and microns. Thus, most literature studies rarely cover temporal and spatial processes at the same time. In this work, we thoroughly investigate the transient cavity-cavity strong-coupling phenomena at THz frequency and find a Rabi-like oscillation in the microcavities, manifested by direct observation of a periodic energy exchange process via a phase-contrast time-resolved imaging system. Our explanation, based on the Jaynes-Cummings model, provides theoretical insight into this transient strong-coupling process. This work provides an opportunity to deeply understand the transient strong-coupling process between THz microcavities, which sheds light on the potential of THz microcavities for high-speed THz sensor and THz chip design.

2.
Glob Chang Biol ; 30(1): e17114, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38273577

RESUMEN

Human activity and climate change affect biodiversity and cause species range shifts, contractions, and expansions. Globally, human activities and climate change have emerged as persistent threats to biodiversity, leading to approximately 68% of the ~522 primate species being threatened with extinction. Here, we used habitat suitability models and integrated data on human population density, gross domestic product (GDP), road construction, the normalized difference vegetation index (NDVI), the location of protected areas (PAs), and climate change to predict potential changes in the distributional range and richness of 26 China's primate species. Our results indicate that both PAs and NDVI have a positive impact on primate distributions. With increasing anthropogenic pressure, species' ranges were restricted to areas of high vegetation cover and in PAs surrounded by buffer zones of 2.7-4.5 km and a core area of PAs at least 0.1-0.5 km from the closest edge of the PA. Areas with a GDP below the Chinese national average of 100,000 yuan were found to be ecologically vulnerable, and this had a negative impact on primate distributions. Changes in temperature and precipitation were also significant contributors to a reduction in the range of primate species. Under the expected influence of climate change over the next 30-50 years, we found that highly suitable habitat for primates will continue to decrease and species will be restricted to smaller and more peripheral parts of their current range. Areas of high primate diversity are expected to lose from 3 to 7 species. We recommend that immediate action be taken, including expanding China's National Park Program, the Ecological Conservation Redline Program, and the Natural Forest Protection Program, along with a stronger national policy promoting alternative/sustainable livelihoods for people in the local communities adjacent to primate ranges, to offset the detrimental effects of anthropogenic activities and climate change on primate survivorship.


Asunto(s)
Cambio Climático , Conservación de los Recursos Naturales , Animales , Humanos , Primates , Biodiversidad , Ecosistema , Actividades Humanas , China
3.
Mol Biol Evol ; 40(11)2023 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-37823401

RESUMEN

The genus Macaca includes 23 species assigned into 4 to 7 groups. It exhibits the largest geographic range and represents the most successful example of adaptive radiation of nonhuman primates. However, intrageneric phylogenetic relationships among species remain controversial and have not been resolved so far. In this study, we conducted a phylogenomic analysis on 16 newly generated and 8 published macaque genomes. We found strong evidence supporting the division of this genus into 7 species groups. Incomplete lineage sorting (ILS) was the primary factor contributing to the discordance observed among gene trees; however, we also found evidence of hybridization events, specifically between the ancestral arctoides/sinica and silenus/nigra lineages that resulted in the hybrid formation of the fascicularis/mulatta group. Combined with fossil data, our phylogenomic data were used to establish a scenario for macaque radiation. These findings provide insights into ILS and potential ancient introgression events that were involved in the radiation of macaques, which will lead to a better understanding of the rapid speciation occurring in nonhuman primates.


Asunto(s)
Genoma , Macaca , Animales , Filogenia , Macaca/genética , Hibridación Genética
4.
Sci Total Environ ; 899: 165746, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37495138

RESUMEN

Climate change significantly affects the suitability of wildlife habitats. Thus, understanding how animals adapt ecologically and genetically to climate change is important for targeted species protection. Rhesus macaques (Macaca mulatta) are widely distributed and multi-climatically adapted primates. This study explored how rhesus macaques adapt to climate change by integrating ecological and genetic methods and applying species distribution models (SDMs) and a gradient forest (GF) model. The findings suggested that temperature seasonality primarily affects habitat suitability and indicated that climate change will have a dramatic impact on macaque populations in the future. We also applied genotype-environment association (GEA) analyses and selection signature analyses to identify genes associated with climate change and provide possible explanations for the adaptation of rhesus macaques to climatic environments. The population genomics analyses suggested that the Taihang population has the highest genomic vulnerability with inbreeding and low heterozygosity. Combined with the higher ecological vulnerability, additional conservation strategies are required for this population under higher risk of climate change. Our work measured the impact of climate change and enabled the identification of populations that exhibit high vulnerability to severe climate change. Such information is useful for selecting populations of rhesus macaques as subject of long-term monitoring or evolutionary rescue under future climate change.


Asunto(s)
Cambio Climático , Ecosistema , Animales , Macaca mulatta/genética , Genómica
5.
Mol Ecol ; 32(14): 3942-3959, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37160724

RESUMEN

Biological introductions provide a natural ecological experiment unfolding in a recent historical timeframe to elucidate how evolutionary processes (such as founder effects, genetic diversity and adaptation) shape the genomic landscape of populations postintroduction. The Asian icefish, Protosalanx chinensis, is an economically important fishery resource, deliberately introduced into dozens of provinces across China for decades. However, while invading and disturbing the local ecosystem, many introduced populations declined, disappearing mysteriously in a very short time. The way in which various evolutionary forces integrate to result in invasion failure of an introduced population remains unknown. Here, we performed whole-genome sequencing of 10 species from the Salangidae family and 70 Asian icefish (Protosalanx chinensis) individuals from 7 geographic populations in China, aiming to characterize the evolutionary fate of introduced populations. Our results show that compared to other Salangidae species, P. chinensis has low genetic diversity, potentially due to the long-lasting decline in population size. In a recently introducted population, Lugu lake, severe sampling effects and a strong bottleneck further deteriorated the genomic landscape. Although the introduced population showed signs of reduced genetic load, the purging selection efficiency was low. Our selective sweep analysis revealed site frequency changes in candidate genes, including gata1a and hoxd4b, which could be associated with a decrease in dissolved oxygen in the deep-water plateau lake. These findings caution against the widespread introduction of P. chinensis in China and lay the groundwork for future use of this economically species.


Asunto(s)
Ecosistema , Genómica , Humanos , Genoma , Evolución Biológica , Adaptación Fisiológica
7.
Medicine (Baltimore) ; 102(10): e33101, 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36897714

RESUMEN

BACKGROUND: Postoperative pain is one of the most feared complications of total knee arthroplasty. Recently, randomized controlled trials have compared the efficacy of duloxetine in patients undergoing total knee arthroplasty. However, there is no definite answer as to the efficacy and safety of duloxetine. METHODS: Randomized controlled trials about relevant studies were searched from PubMed (1996 to July 2022), Embase (1996 to July 2022), and Cochrane Library (CENTRAL, July 2022). RESULTS: Six high-quality studies containing 532 patients met the inclusion criteria. Results show patients in the duloxetine group had better performance in terms of visual analog scale (P < .05), equivalent morphine consumption (P < .05), and length of stay (P < .05). CONCLUSION: Duloxetine can be used to reduce pain after knee arthroplasty in selected patients.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Manejo del Dolor , Humanos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Clorhidrato de Duloxetina , Manejo del Dolor/métodos , Dolor Postoperatorio/etiología , Ensayos Clínicos Controlados Aleatorios como Asunto
8.
World Neurosurg ; 171: e533-e541, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36529433

RESUMEN

BACKGROUND: The study aimed to explore the recent efficacy of oblique lateral interbody fusion (OLIF) combined with Wiltse approach pedicle screw fixation in the treatment of single-level degenerative lumbar spondylolisthesis (DLS). METHODS: This is a retrospective study. The study enrolled 54 patients with single-level DLS who were treated at the Affiliated Jiangnan Hospital of Zhejiang Chinese Medical University from May 2018 to June 2020. (OLIF group) 24 cases operated using OLIF combined with Wiltse approach pedicle screw fixation, and (PLIF group) 30 cases operated by PLIF. The primary outcome measures were visual analog scale (VAS) pain scores, Oswestry dysfunction index (ODI), and the lower lumbar spine anterior convexity angle. RESULTS: There were significant differences in VAS (2.63 ± 0.58 vs. 3.57 ± 0.63, P < 0.001) and ODI (9.67 ± 0.92 vs. 10.63 ± 1.40, P < 0.05) between the OLIF group and PLIF group on postoperative 3 days. And there was a significant decrease in VAS (2.63 ± 0.58 vs. 1.08 ± 0.28, P < 0.05) and ODI (3.57 ± 0.63 vs. 1.10 ± 0.31, P < 0.05) in both groups on postoperative 3 days and at 6 months postoperative comparisons. OLIF group showed better intervertebral space height and the lower lumbar spine anterior convexity angle scores on postoperative 3 days and 6 months, the difference was statistically significant(all P < 0.05). CONCLUSIONS: OLIF combined with the Wiltse approach pedicle screw fixation can achieve good short-term clinical results in the treatment of single-level DLS. This surgical approach is less invasive, promotes early functional recovery, shortens hospitalization time, and improves the quality of life.


Asunto(s)
Tornillos Pediculares , Fusión Vertebral , Espondilolistesis , Humanos , Espondilolistesis/cirugía , Estudios Retrospectivos , Calidad de Vida , Resultado del Tratamiento , Fusión Vertebral/métodos , Vértebras Lumbares/cirugía
9.
Opt Express ; 30(26): 47124-47133, 2022 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36558649

RESUMEN

We propose and experimentally demonstrate that giant asymmetric reflection of circularly polarized light based on asymmetric coupling can be achieved in single-layer extrinsic chiral metasurfaces at oblique incidence. The asymmetric coupling and asymmetric reflection in the extrinsic chiral metasurfaces are caused by extrinsic chirality, allowing them to have extremely high values. An asymmetric reflection of approximately 40% is measured. Furthermore, the asymmetric reflection of extrinsic chiral metasurfaces is demonstrated not only in intensity but also in phase retardation, which induces asymmetric polarization state conversion. An approximately 14° asymmetric reflected polarization offset from the symmetry axis is achieved. Our research provides an effective new method for constructing huge asymmetric coupled systems to manipulate electromagnetic waves.

10.
Integr Zool ; 17(6): 1063-1077, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34932875

RESUMEN

Coastal and demersal chondrichthyans (sharks, rays, and skates) are expected to exhibit high levels of genetic differentiation in areas of complex geomorphology. Population genetic studies investigating the extent to which demographic history shapes the genetic structure of these fishes are rare. Here, we combined mitochondrial DNA (Cytb and ND2) and 8 nuclear microsatellite loci from 244 individuals to examine the population genetic structure and demographic history of the 3 Indo-West Pacific species of sharpnose rays (Telatrygon zugei, Telatrygon biasa, and Trygon crozieri). High levels of genetic variation both within and between species were identified. Phylogenetic analysis partitioned haplotypes into 2 lineages supporting divergence of T. zugei from T. crozieri and T. biasa during the Pleistocene. Furthermore, microsatellite-based clustering analyses identified 4 genetic groups (i.e. T. zugei from Japan, T. zugei from coastal China, T. biasa from Gulf of Thailand, and T. crozieri from the Andaman Sea). Measurements of genetic differentiation also support these 4 groups. Additionally, Pleistocene demographic expansions were examined in all genetic groups. The climate oscillations and current hydrologic cycles in the Indo-West Pacific appear to coincide with the hypothesis regarding speciation and the observed demographic history trends of the sharpnose rays. Considering the species group has, until recently, been thought to be one species, these results are critical for defining management units and guiding conservation efforts to preserve stingray biodiversity.


Asunto(s)
Elasmobranquios , Rajidae , Animales , Rajidae/genética , Filogenia , Elasmobranquios/genética , ADN Mitocondrial/genética , Variación Genética , Demografía , Océano Pacífico
11.
Front Microbiol ; 12: 763022, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34950117

RESUMEN

Ex situ (captivity in zoos) is regarded as an important form of conservation for endangered animals. Many studies have compared differences in the gut microbiome between captive and wild animals, but few have explained those differences at the functional level due to the limited amount of 16S rRNA data. Here, we compared the gut microbiome of captive and wild Rhinopithecus roxellana, whose high degree of dietary specificity makes it a good subject to observe the effects of the captive environment on their gut microbiome, by performing a metagenome-wide association study (MWAS). The Chao1 index was significantly higher in the captive R. roxellana cohort than in the wild cohort, and the Shannon index of captive R. roxellana was higher than that of the wild cohort but the difference was not significant. A significantly increased ratio of Prevotella/Bacteroides, which revealed an increased ability to digest simple carbohydrates, was found in the captive cohort. A significant decrease in the abundance of Firmicutes and enrichment of genes related to the pentose phosphate pathway were noted in the captive cohort, indicating a decreased ability of captive monkeys to digest fiber. Additionally, genes required for glutamate biosynthesis were also significantly more abundant in the captive cohort than in the wild cohort. These changes in the gut microbiome correspond to changes in the composition of the diet in captive animals, which has more simple carbohydrates and less crude fiber and protein than the diet of the wild animals. In addition, more unique bacteria in captive R. roxellana were involved in antibiotic resistance (Acinetobacter) and diarrhea (Desulfovibrio piger), and in the prevention of diarrhea (Phascolarctobacterium succinatutens) caused by Clostridioides difficile. Accordingly, our data reveal the cause-and-effect relationships between changes in the exact dietary composition and changes in the gut microbiome on both the structural and functional levels by comparing of captive and wild R. roxellana.

12.
Nanoscale Res Lett ; 16(1): 175, 2021 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-34874503

RESUMEN

We designed a simple on-chip integrated optical isolator made up of a metal-insulator-metal waveguide and a disc cavity filled with magneto-optical material to enhance the transverse magneto-optical effect through the coin paradox spin-orbit interaction (SOI). The simulation results of the non-reciprocal transmission properties of this optical structure show that a high-performance on-chip integrated optical isolator is obtained. The maximum isolation ratio is greater than 60 dB with a corresponding insertion loss of about 2 dB. The great performance of the optical isolator is attributed to the strong transverse magneto-optical effect, which is enhanced by the coin paradox SOI. Moreover, the enhancement of the transverse magneto-optical effect through the coin paradox SOI is more substantial for smaller azimuthal mode number n. Benefiting from this, the transverse magneto-optical effect remains strong in a wide wavelength range. Additionally, a smaller cavity has a stronger transverse magneto-optical effect in the same wavelength range. Our research provides a new perspective for creating highly integrated magneto-optical devices.

13.
iScience ; 23(7): 101267, 2020 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-32593955

RESUMEN

Salangids, known as Asian icefishes, represent a peculiar radiation within the bony fish order Protacanthopterygii where adult fish retain larval characteristics such as transparent and miniaturized bodies and a cartilaginous endoskeleton into adulthood. Here, we report a de novo genome of Protosalanx chinensis, the most widely distributed salangid lineage. The P. chinensis genome assembly is more contiguous and complete than a previous assembly. We estimate that P. chinensis, salmons, trouts, and pikes diverged from a common ancestor 185 million years ago. A juxtaposition with other fish genomes revealed loss of the genes encoding ectodysplasin-A receptor (EDAR), SCPP1, and four Hox proteins and likely lack of canonical fibroblast growth factor 5 (FGF5) function. We also report genomic variations of P. chinensis possibly reflecting the immune system repertoire of a species with a larval phenotype in sexually mature individuals. The new Asian icefish reference genome provides a solid foundation for future studies.

14.
Sleep Med ; 67: 164-170, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31935618

RESUMEN

OBJECTIVE: To elucidate the sleep quality characteristics and factors related to either good or poor sleep quality in acromegaly patients before surgery and to explore sleep quality changes after transsphenoidal surgery and the factors related to these changes. METHODS: We prospectively enrolled 39 acromegaly patients and 78 patients with nonfunctioning pituitary adenomas. Scales for anxiety, depression, disease stigma and nasal condition were evaluated. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was administered before surgery as well as one month and three months after surgery. RESULTS: A higher percentage of acromegaly patients had poor sleep quality compared to controls (35.9% vs. 5.1%, p < 0.001). In addition, acromegaly patients experienced worse subjective sleep quality, extended sleep latency, increased sleep disturbance and decreased daytime functioning. Higher scores for anxiety, disease stigma and sinonasal outcomes were correlated with worse sleep quality in acromegaly patients. At one month after transsphenoidal surgery, we found worse subjective sleep quality, extended sleep latency, shortened sleep duration, impaired sleep efficiency and increased sleep disturbance in acromegaly patients. At three months postoperatively, most impaired PSQI domains in acromegaly patients recovered to preoperative levels. The use of soluble gauze was related to decreased sleep quality at one month after surgery and severe anxiety and depression were related to improved sleep quality at three months after surgery. CONCLUSIONS: Sleep quality was reduced in acromegaly patients. Moreover, sleep quality initially worsened after surgery but later recovered. Emotional problems and the use of soluble gauze were related factors. CLINICAL TRIAL REGISTRATION: None.


Asunto(s)
Acromegalia/cirugía , Ansiedad/psicología , Depresión/psicología , Neoplasias Hipofisarias/cirugía , Trastornos del Sueño-Vigilia/diagnóstico , Adulto , Femenino , Humanos , Estudios Longitudinales , Masculino , Periodo Posoperatorio , Estudios Prospectivos , Calidad de Vida , Estigma Social , Encuestas y Cuestionarios
15.
Mitochondrial DNA B Resour ; 5(3): 2377-2378, 2020 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-33457798

RESUMEN

For the first time, we illuminate the complete mitochondrial genome (mitogenome) sequence of the Paradiplospinus antarcticus, which is 16,988 bp in size and contains 13 protein-coding (PCGs), 2 rRNA genes, 22 tRNA genes, and one control region.The base composition of the mitogenome is 26.08% A, 26.77% T, 28.46% C and 18.69% G. Here, we selected 11 genera of species from the mostly monotypic snake mackerel family, including representative Antarctic Paradiplospinus antarcticus that have been identified, and constructed phylogenetic trees to better study the snake mackerel family.

16.
Nanoscale Res Lett ; 14(1): 388, 2019 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-31865496

RESUMEN

Circular dichroism (CD) is an interesting phenomenon originating from the interaction of light with chiral molecules or other nanostructures lacking mirror symmetries in three-dimensional (3D) or two-dimensional (2D) space. While the observable effects of optical chirality are very weak in most of the natural materials, they can be designed and significantly enhanced in synthetic chiral structures, where the spatial symmetry of their component are broken on a nanoscale. Therefore, fabrication of composites capable of cheap, time-saving, and giant CD is desirable for the advanced optical technologies. Here, the giant CD of large-area metal nanocrescent array structures was investigated theoretically and experimentally. The largest value of the CD spectrum measured was larger than 0.5, and the CD spectrum was tuned effectively and extensively while maintaining a large peak intensity, which can be attributed to the selective excitation of the lattice surface modes (LSMs) by circularly polarized light. The analysis of the extrinsic chiral structure shows potential applications in chiral molecule sensing and polarizing imaging.

17.
Opt Express ; 27(16): 22819-22826, 2019 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-31510567

RESUMEN

The discovery of topological photonic states has revolutionized our understanding of electromagnetic propagation and scattering. With the introduction of topology, some attractive properties such as unidirectional propagation and robustness against defects and impurities will be endowed to photonic edge modes. In this study, two-dimensionally confined topological edge states were achieved at terahertz (THz) frequency based on an all-dielectric photonic crystal structure. Trivial and nontrivial bandgaps of two deforming honeycomb lattices as well as unidirectional topological edge states were observed. Because the topological edge states with opposite helicity propagated in opposite directions at the interface, a polarization-resolved characteristic was demonstrated here, and thus a continuously tunable power splitter was achieved. This study provides some insights for further THz topological studies and possibilities for THz integrated platforms.

18.
Opt Express ; 27(5): 7373-7383, 2019 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-30876302

RESUMEN

We experimentally demonstrate on-chip plasmon-induced transparency at THz frequencies using a meta-structure deposited on a 50 µm-thick dielectric subwavelength waveguide. The obvious plasmon-induced transparency results from strong coupling between the respective modes of a cut wire and a double-gap split ring resonator. The simulation and experimental results are consistent. Based on our numerical simulations of the temporal evolution of plasmon-induced transparency, a π/2 phase difference at the transparency peak between the above two modes is observed, i.e., there is energy oscillating between them that exhibits Rabi oscillation-like behavior. In addition, at the transparency peak, a strong local-field enhancement effect and high transmission can be obtained simultaneously, which can be tuned by changing the separation between the cut wire and the double-gap split ring resonator. These results will facilitate the design of THz integrated photonic devices and serve as an excellent platform for nonlinear optics and sensing.

19.
Nanoscale Res Lett ; 13(1): 392, 2018 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-30515587

RESUMEN

An optical diode structure with two dislocated parallel metallic gratings is proposed and investigated numerically. Dichroic optical diode transmission is realized in this structure, i.e., optical diode effect is observed in two wavebands corresponding to inverse transmission directions. In the structure, two parallel metallic gratings with different grating constants are separated by a dielectric slab in between. The first illuminated grating acts as a selector for exciting surface plasmons at a proper wavelength. The other grating acts as an emitter to realize optical transmission. When the incident direction is reversed, the roles of two gratings exchange and surface plasmons are excited at another wavelength. In dichroic transmission wavebands, the optical diode structure exhibits extraordinary transmission and possesses high optical isolation up to 1. Furthermore, the operating wavebands can be modulated by changing structure parameters.

20.
Opt Express ; 26(2): 1954-1961, 2018 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-29401916

RESUMEN

We quantitatively demonstrate transient establishment of wavefronts for negative, zero, and positive refraction through a wedge-shaped metamaterial consisting of periodically arranged split-ring resonators and metallic wires. The wavefronts for the three types of refractions propagate through the second interface of the wedge along positive refraction angles at first, then reorganize, and finally propagate along the effective refraction angles after a period of establishment time respectively. The establishment time of the wavefronts prevents violating causality or superluminal propagation for negative and zero refraction. The establishment time for negative or zero refraction is longer than that for positive refraction. For all three refraction processes, transient establishment processes precede the establishment of steady propagation. Moreover, some detailed characters are proven in our research, including infinite wavelength, uniform phase inside the zero-index material, and the phase velocity being antiparallel to the group velocity in the negative-index material.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...