Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
1.
Micromachines (Basel) ; 15(6)2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38930766

RESUMO

This study introduces a novel approach for fabricating vertically stacked mini-LED arrays, integrating InGaN yellow and blue epitaxial layers with a stress buffer layer to enhance optoelectronic characteristics and structural stability. This method significantly simplifies the LED design by reducing the need for RGB configurations, thus lowering costs and system complexity. Employing vertical stacking integration technology, the design achieves high-density, efficient white light production suitable for multifunctional applications, including automotive lighting and outdoor signage. Experimental results demonstrate the exceptional performance of the stacked yellow and blue mini-LEDs in terms of luminous efficiency, wavelength precision, and thermal stability. The study also explores the performance of these LEDs under varying temperature conditions and their long-term reliability, indicating that InGaN-based yellow LEDs offer superior performance over traditional AlGaInP yellow LEDs, particularly in high-temperature environments. This technology promises significant advancements in the design and application of lighting systems, with potential implications for both automotive and general illumination markets.

2.
Behav Brain Res ; 471: 115068, 2024 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-38830386

RESUMO

Alcohol-Related Brain Damage (ARBD) manifests predominantly as cognitive impairment and brain atrophy with the hippocampus showing particular vulnerability. Fasudil, a Rho kinase (ROCK) inhibitor, has established neuroprotective properties; however, its impact on alcohol-induced cognitive dysfunction and hippocampal structural damage remains unelucidated. This study probes Fasudil's neuroprotective potential and identifies its mechanism of action in an in vivo context. Male C57BL/6 J mice were exposed to 30% (v/v, 6.0 g/kg) ethanol by intragastric administration for four weeks. Concurrently, these mice received a co-treatment with Fasudil through intraperitoneal injections at a dosage of 10 mg/kg/day. Fasudil was found to mitigate alcohol-induced spatial and recognition memory deficits, which were quantified using Y maze, Morris water maze, and novel object recognition tests. Concurrently, Fasudil attenuated hippocampal structural damage prompted by chronic alcohol exposure. Notably, Fasudil moderated alcohol-induced disassembly of the actin cytoskeleton and microtubules-mechanisms central to the maintenance of hippocampal synaptic integrity. Collectively, our findings indicate that Fasudil partially reverses alcohol-induced cognitive and morphological detriments by modulating cytoskeletal dynamics, offering insights into potential therapeutic strategies for ARBD.


Assuntos
1-(5-Isoquinolinasulfonil)-2-Metilpiperazina , Disfunção Cognitiva , Etanol , Hipocampo , Camundongos Endogâmicos C57BL , Microtúbulos , Fármacos Neuroprotetores , Animais , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Hipocampo/metabolismo , Masculino , Camundongos , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/induzido quimicamente , Etanol/farmacologia , Fármacos Neuroprotetores/farmacologia , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Modelos Animais de Doenças , Reconhecimento Psicológico/efeitos dos fármacos
3.
J Neurosurg ; : 1-11, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38728755

RESUMO

OBJECTIVE: The aim of this study was to develop and validate a predictive nomogram model for long-term rebleeding events in patients with hemorrhagic moyamoya disease (HMMD). METHODS: In total, 554 patients with HMMD from the Fifth Medical Center of the Chinese PLA General Hospital (5-PLAGH cohort) were included and randomly divided into training (390 patients) and internal validation (164 patients) sets. An independent cohort from the First Medical Center and Eighth Medical Center of Chinese PLA General Hospital (the 1-PLAGH and 8-PLAGH cohort) was used for external validation (133 patients). Univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) regression algorithm were used to identify significant factors associated with rebleeding, which were used to develop a nomogram for predicting 5- and 10-year rebleeding. RESULTS: Intraventricular hemorrhage was the most common type of cerebral hemorrhage (39.0% of patients in the 5-PLAGH cohort and 42.9% of the 1-PLAGH and 8-PLAGH cohort). During the mean ± SD follow-up period of 10.4 ± 2.9 years, 91 (16.4%) patients had rebleeding events in the 5-PLAGH cohort. The rebleeding rates were 12.3% (68 patients) at 5 years and 14.8% (82 patients) at 10 years. Rebleeding events were observed in 72 patients (14.3%) in the encephaloduroarteriosynangiosis (EDAS) surgery group, whereas 19 patients (37.3%) experienced rebleeding events in the conservative treatment group. This difference was statistically significant (p < 0.001). We selected 4 predictors (age at onset, number of episodes of bleeding, posterior circulation involvement, and EDAS surgery) for nomogram development. The concordance index (C-index) values of the nomograms of the training cohort, internal validation cohort, and the external validation cohort were 0.767 (95% CI 0.704-0.830), 0.814 (95% CI 0.694-0.934), and 0.718 (95% CI 0.661-0.775), respectively. The nomogram at 5 years exhibited a sensitivity of 48.1% and specificity of 87.5%. The positive and negative predictive values were 38.2% and 91.3%, respectively. The nomogram at 10 years exhibited a sensitivity of 47.1% and specificity of 89.1%. The positive and negative predictive values were 48.5% and 88.5%, respectively. CONCLUSIONS: EDAS may prevent rebleeding events and improve long-term clinical outcomes in patients with HMMD. The nomogram accurately predicted rebleeding events and assisted clinicians in identifying high-risk patients and devising individual treatments. Simultaneously, comprehensive and ongoing monitoring should be implemented for specific patients with HMMD throughout their entire lifespan.

4.
J Neurosurg ; : 1-10, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38759234

RESUMO

OBJECTIVE: Diabetes is often linked to poorer outcomes in patients with moyamoya disease (MMD). However, experience has shown that certain individuals with diabetes have favorable outcomes after encephaloduroarteriosynangiosis (EDAS). The authors aimed to develop a nomogram to predict good neoangiogenesis in patients with MMD and type 2 diabetes mellitus (T2DM) to aid neurosurgeons in the identification of suitable candidates for EDAS. METHODS: Adults with MMD and T2DM who underwent EDAS between June 2004 and December 2018 were included in the analysis. In total, 126 patients (213 hemispheres) with MMD and T2DM from the Fifth Medical Centre of the Chinese PLA General Hospital were included and randomly divided into training (152 hemispheres) and internal validation (61 hemispheres) cohorts at a ratio of 7:3. Univariate logistic and least absolute shrinkage and selection operator regression analyses were used to identify the significant factors associated with good neoangiogenesis, which were used to develop a nomogram. The discrimination, calibration, and clinical utility were assessed. RESULTS: A total of 213 hemispheres in 126 patients were reviewed, including 152 (71.36%) hemispheres with good postoperative collateral formation and 61 (28.64%) with poor postoperative collateral formation. The authors selected 4 predictors (FGD5 rs11128722, VEGFA rs9472135, Suzuki stage, and internal carotid artery [ICA] moyamoya vessels) for nomogram development. The C-indices of the nomogram in the training and internal validation cohorts were 0.873 and 0.841, respectively. The nomogram exhibited a sensitivity of 84.5% and specificity of 81.0%. The positive and negative predictive values were 92.1% and 66.7%, respectively. The calibration curves indicated high predictive accuracy, and receiver operating characteristic curve analysis showed the superiority of the nomogram. The decision-making analysis validated the fitness and clinical application value of this nomogram. Then a web-based calculator to facilitate clinical application was generated. CONCLUSIONS: The nomogram developed in this study accurately predicted neoangiogenesis in patients with MMD and T2DM after EDAS and may assist neurosurgeons in identifying suitable candidates for indirect revascularization surgery.

5.
Stroke Vasc Neurol ; 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38460971

RESUMO

BACKGROUND: The relationship between anterior cerebral artery (ACA) occlusion and moyamoya disease (MMD) has rarely been studied. In this study, we focused on a special type of MMD: isolated ACA-occlusive MMD. We investigated clinical attributes, genotypes and progression risk factors in patients with ACA-occlusive MMD, providing initial insights into the relationship between ACA occlusion and MMD. METHODS: We retrospectively analysed digital subtraction angiography (DSA) from 2486 patients and diagnosed 139 patients with ACA-occlusive MMD. RNF213 p.R4810K (rs112735431) mutation analysis was performed. Patients were categorised into progression and non-progression groups based on whether they progressed to typical MMD. Differences in clinical characteristics, neuropsychological assessment, radiological findings and genotypes were evaluated. Logistic regression analyses identified risk factors for ACA-occlusive MMD progression. RESULTS: The median age of patients with ACA-occlusive MMD was 36 years, and the primary symptom was transient ischaemic attack (TIA). 72.3% of ACA-occlusive MMD patients had cognitive decline. Of 116 patients who underwent RNF213 gene mutation analysis, 90 patients (77.6%) carried the RNF213 p.R4810K GG allele and 26 (22.4%) carried the GA allele. Of 102 patients with follow-up DSA data, 40 patients (39.2%) progressed. Kaplan-Meier curve estimates indicated a higher incidence of ischaemic stroke in the progression group during follow-up (p=0.035). Younger age (p=0.041), RNF213 p.R4810K GA genotype (p=0.037) and poor collateral compensation from the middle cerebral artery (MCA) to ACA (p<0.001) were risk factors of ACA-occlusive MMD progression to typical MMD. CONCLUSIONS: Cognitive decline and TIA might be the main manifestations of ACA-occlusive MMD. Isolated ACA occlusion may be an early signal of MMD. The initial lesion site of MMD is not strictly confined to the terminal portion of the internal carotid artery. Younger patients, patients with RNF213 p.R4810K GA genotype or those with inadequate MCA-to-ACA compensation are more likely to develop typical MMD.

6.
Animals (Basel) ; 14(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38473118

RESUMO

Resource partitioning may allow species coexistence. Sand dunes in the typical steppe of Alxa Desert Inner Mongolia, China, consisting of desert, shrub, and grass habitats, provide an appropriate system for studies of spatial niche partitioning among small mammals. In this study, the spatial niche characteristics of four rodents, Orientallactaga sibirica, Meriones meridianus, Dipus sagitta, and Phodopus roborovskii, and their responses to environmental changes in the Alxa Desert were studied from 2017 to 2021. Using the capture-mark-recapture method, we tested if desert rodents with different biological characteristics and life history strategies under heterogeneous environmental conditions allocate resources in spatial niches to achieve sympatric coexistence. We investigated the influence of environmental factors on the spatial niche breadth of rodents using random forest and redundancy analyses. We observed that the spatial niche overlap between O. sibirica and other rodents is extremely low (overlap index ≤ 0.14). P. roborovskii had the smallest spatial niche breadth. Spatial niche overlap was observed in two distinct species pairs, M. meridianus and D. sagitta, and P. roborovskii and D. sagitta. The Pielou evenness index of rodent communities is closely related to the spatial distribution of rodents, and the concealment of habitats is a key factor affecting the spatial occupation of rodents.

7.
J Inflamm Res ; 17: 1721-1733, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38523687

RESUMO

Background: The immune system plays an important role in the onset and development of moyamoya disease (MMD), but the specific mechanisms remain unclear. This study aimed to explore the relationship between the expression of complements and immunoglobulin in serum and progression of MMD. Methods: A total of 84 patients with MMD and 70 healthy individuals were enrolled. Serum immunoglobulin and complement C3 and C4 expression were compared between healthy individuals and MMD patients. Follow-up was performed at least 6 months post-operation. Univariate and multivariate analysis after adjusting different covariates were performed to explore predictive factors associated with vasculopathy progression. A nomogram basing on the results of multivariate analysis was established to predict vasculopathy progression. Results: Compared to healthy individuals, MMD patients had significantly lower expression of serum complements C3 (P = 0.003*). Among MMD patients, C3 was significantly lower in those with late-stage disease (P = 0.001*). Of 84 patients, 27/84 (32.1%) patients presented with vasculopathy progression within a median follow-up time of 13.0 months. Age (P=0.006*), diastolic blood pressure (P=0.004*) and serum complement C3 expression (P=0.015*) were associated with vasculopathy progression after adjusting different covariables. Conclusion: Complement C3 is downregulated in moyamoya disease and decreases even further in late-Suzuki stage disease. Age, diastolic blood pressure and serum complement C3 expression are associated with vasculopathy progression, suggesting that the complement might be involved in the development of moyamoya disease.

8.
Sci Rep ; 14(1): 7018, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528020

RESUMO

This study showcases a method for achieving high-performance yellow and red micro-LEDs through precise control of indium content within quantum wells. By employing a hybrid quantum well structure with our six core technologies, we can accomplish outstanding external quantum efficiency (EQE) and robust stripe bandwidth. The resulting 30 µm × 8 micro-LED arrays exhibit maximum EQE values of 11.56% and 5.47% for yellow and red variants, respectively. Notably, the yellow micro-LED arrays achieve data rates exceeding 1 Gbit/s for non-return-to-zero on-off keying (NRZ-OOK) format and 1.5 Gbit/s for orthogonal frequency-division multiplexing (OFDM) format. These findings underscore the significant potential of long-wavelength InGaN-based micro-LEDs, positioning them as highly promising candidates for both full-color microdisplays and visible light communication applications.

9.
Heliyon ; 10(4): e26108, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38404780

RESUMO

Objective: This study aimed to explore the long-term outcome of unilateral moyamoya disease and predict the clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease. Methods: We retrospectively recruited unilateral moyamoya disease patients with available genetic data who underwent encephaloduroarteriosynangiosis (EDAS) surgery at our institution from January 2009 to November 2017. Long-term follow-up data, including clinical outcomes, angiographic features, and genetic information, were analyzed. Results: A total of 83 unilateral moyamoya disease patients with available genetic data were enrolled in our study. The mean duration of clinical follow-up was 7.9 ± 2.0 years. Among all patients, 19 patients demonstrated contralateral progression to bilateral disease. Heterozygous Ring Finger Protein 213 p.R4810K mutations occurred significantly more frequently in unilateral moyamoya disease patients with contralateral progression. Furthermore, patients with contralateral progression typically demonstrated an earlier age of onset than those with non-progressing unilateral moyamoya disease. In the contralateral progression group, posterior circulation involvement was observed in 11 (11/19, 57.9%) patients compared to 12 (12/64, 18.8%) in the non-contralateral progression group (P = 0.001). The time to peak of cerebral perfusion and neurological status showed significant postoperative improvement. Conclusion: Long-term follow-up revealed that the EDAS procedure might provide benefits for unilateral moyamoya disease patients. Ring Finger Protein 213 p.R4810K mutations, younger age, and posterior circulation involvement might predict the contralateral progression of unilateral moyamoya disease.

10.
J Neurosurg ; 140(3): 800-808, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37724788

RESUMO

OBJECTIVE: This study aimed to explore the clinical features of moyamoya disease (MMD) and the efficacy of encephaloduroarteriosynangiosis (EDAS) in elderly patients with MMD and to identify the risk factors for long-term stroke events. METHODS: Clinical data were retrospectively collected on elderly patients with MMD (age ≥ 60 years) who had been treated at the authors' center from May 2007 to December 2017. Clinical features, angiographic findings, and long-term outcomes (> 5-year follow-up) were analyzed. Cox regression analysis was performed to determine the risk factors for postoperative stroke events. Long-term stroke events were analyzed using Kaplan-Meier curves. RESULTS: The mean age at symptom onset was 62.9 ± 3.0 years among 111 elderly patients with MMD. Vascular comorbidities were present in 80 (72.1%) patients. The ratio of female to male patients was 1:1.2. Familial MMD was found in 7 (6.3%) patients. Cerebral ischemia was the most common clinical manifestation observed in 82 (73.9%) patients. Most patients (59.5%) presented with Suzuki stages 5 and 6 MMD, and 29 (26.1%) patients presented with stenosis or occlusion of the posterior circulation. Unilateral MMD was present in 17 (15.3%) patients. Among the 58 (52.3%) patients who underwent EDAS, 28 (48.3%) and 30 (51.7%) underwent bilateral and unilateral surgeries, respectively. Overall, 53 (47.7%) patients were treated conservatively using internal medicine. After a median follow-up duration of 8.2 years, stroke incidence in the EDAS and conservative treatment groups was respectively 17.2% (7 and 3 cases of cerebral infarction and hemorrhage, respectively) and 49.1% (22 and 4 cases of cerebral infarction and hemorrhage, respectively). The stroke incidence rate was higher in the conservative group than in the EDAS group, with a statistically significant difference (p = 0.001) according to results of the Kaplan-Meier analysis. The identified predictor of postoperative stroke events was initial hemorrhage in the EDAS group and advanced age, aneurysm, and initial ischemia in the conservative treatment group. CONCLUSIONS: The postoperative long-term stroke rate among elderly patients with MMD was lower in the EDAS group than in the conservative treatment group. Long-term stroke events were associated with advanced age, aneurysm, and initial ischemia after conservative treatment and only initial hemorrhage after EDAS.


Assuntos
Aneurisma , Doença de Moyamoya , Acidente Vascular Cerebral , Idoso , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Transversais , Doença de Moyamoya/epidemiologia , Doença de Moyamoya/cirurgia , Estudos Retrospectivos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/terapia , Infarto Cerebral , Hemorragia
11.
Discov Nano ; 18(1): 149, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38062340

RESUMO

Free-space optical communications hold promising advantages, including a large bandwidth, access to license-free spectrum, high data rates, quick and simple deployment, low power consumption, and relaxed quality requirements. Nevertheless, key technical challenges remain, such as a higher transmission efficiency, a lower transmission loss, and a smaller form factor of optical systems. Here, we demonstrate the viability of circular-polarization-multiplexed multi-channel optical communication using metasurfaces alongside a photonic-crystal surface-emitting laser (PCSEL) light source at wavelength of 940 nm. Through the light manipulation with metasurface, we split the linearly polarized incidence into left and right circular polarizations with desired diffraction angles. Such orthogonal polarization states provide a paradigm of polarization division multiplexing technique for light communication. The PCSEL light source maintains a low divergence angle of about 0.373 degrees after passing through an ultra-thin metasurface without further bulky collimator or light guide, making end-to-end (E2E) and device-to-device (D2D) communications available in a compact form. Both light source and modulated polarized light exhibit a - 3 dB bandwidth over 500 MHz, with successful 1 Gbit/s transmission demonstrated in eye diagrams. Our results affirm that metasurface effectively boosts transmission capacity without compromising the light source's inherent properties. Future metasurface designs could expand channel capacity, and its integration with PCSEL monolithically holds promise for reducing interface losses, thereby enhancing efficiency.

12.
Dermatol Pract Concept ; 13(4)2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37992347
13.
Huan Jing Ke Xue ; 44(10): 5524-5535, 2023 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-37827769

RESUMO

For the surface sediment samples of Taihu Lake in 2010, the eight physicochemical indices of pH, temperature, Eh, water content, porosity, grain size, total phosphorus, and Loss-on-ignition were measured and analyzed, along with the contents of nine heavy metals:Cu, Zn, Ni, Cr, Pb, Ba, Mn, Co, and V. The order of magnitudes of heavy metal content of surface sediments in Taihu Lake was:Mn>Ba>Zn>Cr>V>Ni>Pb>Cu>Co. This suggested that the contents of the nine heavy metals were beyond the background value, which had a close connection to the geology of the Taihu Lake Basin and were influenced by human activity to varying degrees. The clustering analysis and the spatial distribution of the heavy metals revealed that the concentrations of heavy metals in the North and South Taihu Lake sections decreased from the lake shore to the lake center, the concentrations of heavy metals in the West Taihu Lake section increased from the lake shore to the lake center, and the distribution of heavy metals in the center of the lake remained relatively uniform. According to the correlation study, the metal elements were positively correlated with one another to varying degrees, indicating that they originate from the same source of pollution. According to the PCA and PMF analyses, there were some different sources of heavy metals in Taihu Lake, in which the transportation and industrial complex source were the most important sources, the diagenesis was the second major source, and agriculture was the third major source. Furthermore, the heavy metal pollution was evaluated using the geoaccumulation and the potential ecological risk indices. This offers a solid theoretical backing for the future management of heavy metal pollution in Taihu Lake.

14.
Biomacromolecules ; 24(11): 5353-5363, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37871289

RESUMO

The silencing of disease-causing genes with small interfering RNA (siRNA) offers a particularly effective therapeutic strategy for different disorders; however, its clinical efficacy relies on the development of nontoxic and tissue-specific delivery vehicles. Herein, we report that bioresponsive chimaeric polymersomes (BCP) with short poly(ethylenimine) as inner shell mediate highly efficacious, sustained, and liver-specific siRNA transfection in vivo. BCP exhibited remarkable encapsulation efficiencies of siRNA (95-100%) at siRNA-feeding contents of 15-25 wt %, to afford stable, small-sized (55-64 nm), and neutral-charged BCP-siRNA. siApoB-Loaded BCP (BCP-siApoB) outperformed lipofectamine counterparts and silenced 93% of ApoB mRNA in HepG2 cells at 50 nM siApoB without inducing cytotoxicity. Intriguingly, the in vivo studies using wild-type C57BL/6 mice revealed that BCP-siApoB preferentially accumulated in the liver, and a single dose of 4.5 mg/kg achieved over 90% downregulation of ApoB mRNA for at least 10 days. The systemic administration of BCP-siApoB at 4.5 mg/kg every 2 weeks or 1.5 mg/kg weekly in diet-induced obese mice could also achieve up to 80% silencing of ApoB mRNA. The liver specificity and silencing efficacy of BCP-siApoB could further be improved by decorating it with the trivalent N-acetylgalactosamine (TriGalNAc) ligand. These bioresponsive and liver-specific chimaeric polymersomes provide an enabling technology for siRNA therapy of various liver-related diseases.


Assuntos
Apolipoproteínas B , Fígado , Animais , Camundongos , RNA Interferente Pequeno/genética , Camundongos Endogâmicos C57BL , Apolipoproteínas B/genética , Transfecção , RNA Mensageiro
15.
Discov Nano ; 18(1): 95, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37498403

RESUMO

In this study, we have demonstrated the potential of InGaN-based red micro-LEDs with single quantum well (SQW) structure for visible light communication applications. Our findings indicate the SQW sample has a better crystal quality, with high-purity emission, a narrower full width at half maximum, and higher internal quantum efficiency, compared to InGaN red micro-LED with a double quantum wells (DQWs) structure. The InGaN red micro-LED with SQW structure exhibits a higher maximum external quantum efficiency of 5.95% and experiences less blueshift as the current density increases when compared to the DQWs device. Furthermore, the SQW device has a superior modulation bandwidth of 424 MHz with a data transmission rate of 800 Mbit/s at an injection current density of 2000 A/cm2. These results demonstrate that InGaN-based SQW red micro-LEDs hold great promise for realizing full-color micro-display and visible light communication applications.

16.
Int J Mol Sci ; 24(11)2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37298074

RESUMO

Heat sensation and tolerance are crucial for determining species' survival and distribution range of small mammals. As a member of the transmembrane proteins, transient receptor potential vanniloid 1 (TRPV1) is involved in the sensation and thermoregulation of heat stimuli; however, the associations between animal's heat sensitivity and TRPV1 in wild rodents are less studied. Here, we found that Mongolian gerbils (Meriones unguiculatus), a rodent species living in Mongolia grassland, showed an attenuated sensitivity to heat compared with sympatrically distributed mid-day gerbils (M. meridianus) based on a temperature preference test. To explain this phenotypical difference, we measured the TRPV1 mRNA expression of two gerbil species in the hypothalamus, brown adipose tissue, and liver, and no statistical difference was detected between two species. However, according to the bioinformatics analysis of TRPV1 gene, we identified two single amino acid mutations on two TRPV1 orthologs in these two species. Further Swiss-model analyses of two TRPV1 protein sequences indicated the disparate conformations at amino acid mutation sites. Additionally, we confirmed the haplotype diversity of TRPV1 in both species by expressing TRPV1 genes ectopicly in Escherichia coli system. Taken together, our findings supplemented genetic cues to the association between the discrepancy of heat sensitivity and the functional differentiation of TRPV1 using two wild congener gerbils, promoting the comprehension of the evolutionary mechanisms of the TRPV1 gene for heat sensitivity in small mammals.


Assuntos
Regulação da Temperatura Corporal , Temperatura Alta , Animais , Gerbillinae/metabolismo , Regulação da Temperatura Corporal/genética , Aminoácidos/metabolismo , Variação Genética
17.
Discov Nano ; 18(1): 77, 2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37382747

RESUMO

This study presents a comprehensive analysis of the structural and optical properties of an InGaN-based red micro-LED with a high density of V-shaped pits, offering insights for enhancing emission efficiency. The presence of V-shaped pits is considered advantageous in reducing non-radiative recombination. Furthermore, to systematically investigate the properties of localized states, we conducted temperature-dependent photoluminescence (PL). The results of PL measurements indicate that deep localization in the red double quantum wells can limit carrier escape and improve radiation efficiency. Through a detailed analysis of these results, we extensively investigated the direct impact of epitaxial growth on the efficiency of InGaN red micro-LEDs, thereby laying the foundation for improving efficiency in InGaN-based red micro-LEDs.

18.
Huan Jing Ke Xue ; 44(5): 2767-2774, 2023 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-37177949

RESUMO

Nitrogen (N) deposition in the context of human activities continuously affects the carbon cycle of ecosystems. The effect of N deposition on soil organic carbon is related to the differential responses of different carbon fractions. To investigate the changes in soil organic carbon fraction and its influencing factors in the context of short-term N deposition, four N addition gradients:0 (CK), 1.5 (N1), 3 (N2), and 6 (N3) g·(m2·a)-1 were set up in acacia plantations based on field N addition experiments, and the soil physicochemical properties, microbial biomass, and enzyme activities were measured in June and September. The results showed that:① exogenous N input reduced soil pH, promoted the increase in soluble organic carbon content, and increased soil nitrogen effectiveness. ② Short-term N addition significantly reduced soil organic carbon content, and the response of each component of organic carbon to N addition was different. Among them, the content of easily oxidized organic carbon was significantly reduced and reached the lowest value under the N2 treatment, with 54.4% and 48.2% reduction compared with that of the control, respectively, and the content of inert organic carbon increased, although the increase was not significant. Nitrogen addition reduced the soil carbon pool activity and improved the stability of the soil carbon pool. Soil carbon pool activity reached its lowest under the N3 and N2 treatments, with a decrease of 53.3% and 52.80%, respectively, compared to that of the control. ③Random forest modeling indicated that the soil microbial biomass stoichiometry ratio, microbial biomass carbon, and AP were the key factors driving the changes in soil organic carbon activity under short-term N addition, explaining 65.96% and 66.68% of the changes in oxidizable organic carbon and inert organic carbon, respectively. Structural equation modeling validated the results of the random forest modeling, and soil microbial biomass stoichiometric ratios significantly influenced carbon pool activity. Short-term nitrogen addition changed soil microbial biomass and its stoichiometric ratio in the acacia plantation forest mainly through two pathways, i.e., increasing soil nitrogen effectiveness and promoting soil acidification and inhibiting extracellular carbon hydrolase activity, thus changing the soil carbon fraction ratio and participating in the soil organic carbon cycling process.


Assuntos
Ecossistema , Robinia , Humanos , Carbono/análise , Robinia/metabolismo , Nitrogênio/análise , Solo/química , Microbiologia do Solo , Biomassa , China
19.
Front Neurol ; 14: 1115909, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36846147

RESUMO

Background and objective: The natural course and risk factors of moyamoya disease (MMD) associated with unruptured intracranial aneurysms involving stenosed parental arteries are scarcely studied. This study aimed to elucidate the natural course of MMD and its associated risk factors in patients with MMD with unruptured aneurysms. Methods: Between September 2006 and October 2021, patients with MMD with intracranial aneurysms at our center were examined. The natural course, clinical features, radiological features, and follow-up outcomes after revascularization were analyzed. Results: This study included 42 patients with MMD with intracranial aneurysms (42 aneurysms). The age distribution of MMD cases ranged from 6 to 69 years, with four children (9.5%) and 38 adults (90.5%). A total of 17 male and 25 female subjects were included (male-to-female ratio: 1:1.47). The first symptom was cerebral ischemia in 28 cases, and cerebral hemorrhage occurred in 14 cases. There were 35 trunk aneurysms and seven peripheral aneurysms. There were 34 small aneurysms (<5 mm) and eight medium aneurysms (5-15 mm). During the average clinical follow-up period of 37.90 ± 32.53 months, there was no rupture or bleeding from aneurysms. Twenty-seven of these patients underwent a cerebral angiography review, in which it was found that one aneurysm had enlarged, 16 had remained unchanged, and 10 had shrunk or disappeared. A correlation exists between the reduction or disappearance of aneurysms and the progression of the Suzuki stages of MMD (P = 0.015). Nineteen patients underwent EDAS on the aneurysm side, and nine aneurysms disappeared, while eight patients did not undergo EDAS on the aneurysm side and one aneurysm disappeared. Conclusion: The risk of rupture and hemorrhage of unruptured intracranial aneurysms is low when the parent artery already has stenotic lesions, thus, direct intervention may not be necessary for such aneurysms. The progression of the Suzuki stage of moyamoya disease may play a role in the shrinkage or disappearance of the aneurysms, thereby decreasing the risk of rupture and hemorrhage. Encephaloduroarteriosynangiosis (EDAS) surgery may also help promote atrophy or even the disappearance of the aneurysm, thus reducing the risk of further rupture and bleeding.

20.
Ying Yong Sheng Tai Xue Bao ; 34(1): 83-91, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36799380

RESUMO

Bamboo nodes play a key role in the hollow structure and the rapid growth of bamboo culm. Studying on the anatomical structure of bamboo is helpful to understand its growth mechanism. Taking the noninvasive, high-resolution and accurate technical advantages of magnetic resonance imaging (MRI), we conducted cross-sectional high-resolution MRI scanning on the tip of young Moso bamboo culm (removed shoot sheath) and extracted the gray value of the MRIs by using MATLAB software to explore the differences of water distribution in nodes, proximal nodes, and internodes. The results showed that numerous vascular bundles were repeatedly twisted and rotated horizontally at the nodal diaphragms and inner wall near the nodal diaphragms of the young bamboo, forming an intricate and highly connected network. The structure protected important tissues from mechanical stress by allocating axial loads, and enabled to laterally transport water and nutrients, which was an important basis for the rapid growth of Moso bamboo in relatively short term. The signal value (also known as brightness value) of MRIs indicated that water content of vascular bundles in young bamboo culm was much higher than that of surrounding parenchyma tissues. The mean value and standard deviation of water content between pixels of internodes were significantly higher than that of nodes, and the values of that in the proximal nodes were intermediate. The development of MRI would play a significant role in the studies of bamboo anatomy, physiology, and biochemistry.


Assuntos
Imageamento por Ressonância Magnética , Poaceae , Poaceae/anatomia & histologia , Poaceae/crescimento & desenvolvimento , Brotos de Planta/anatomia & histologia , Brotos de Planta/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA