Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 132
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Respir Res ; 25(1): 165, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38622589

ABSTRACT

Little is known about the relationships between human genetics and the airway microbiome. Deeply sequenced airway metagenomics, by simultaneously characterizing the microbiome and host genetics, provide a unique opportunity to assess the microbiome-host genetic associations. Here we performed a co-profiling of microbiome and host genetics with the identification of over 5 million single nucleotide polymorphisms (SNPs) through deep metagenomic sequencing in sputum of 99 chronic obstructive pulmonary disease (COPD) and 36 healthy individuals. Host genetic variation was the most significant factor associated with the microbiome except for geography and disease status, with its top 5 principal components accounting for 12.11% of the microbiome variability. Within COPD individuals, 113 SNPs mapped to candidate genes reported as genetically associated with COPD exhibited associations with 29 microbial species and 48 functional modules (P < 1 × 10-5), where Streptococcus salivarius exhibits the strongest association to SNP rs6917641 in TBC1D32 (P = 9.54 × 10-8). Integration of concurrent host transcriptomic data identified correlations between the expression of host genes and their genetically-linked microbiome features, including NUDT1, MAD1L1 and Veillonella parvula, TTLL9 and Stenotrophomonas maltophilia, and LTA4H and Haemophilus influenzae. Mendelian randomization analyses revealed a potential causal link between PARK7 expression and microbial type III secretion system, and a genetically-mediated association between COPD and increased relative abundance of airway Streptococcus intermedius. These results suggest a previously underappreciated role of host genetics in shaping the airway microbiome and provide fresh hypotheses for genetic-based host-microbiome interactions in COPD.


Subject(s)
Microbiota , Pulmonary Disease, Chronic Obstructive , Humans , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/genetics , Pulmonary Disease, Chronic Obstructive/complications , Microbiota/genetics , Sputum , Transcriptome , Human Genetics , Adaptor Proteins, Signal Transducing/genetics
2.
J Phys Chem A ; 128(19): 3848-3854, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38691198

ABSTRACT

Energy transfer between atoms and molecules is fundamental to many physical and chemical processes, and understanding the mechanisms and outcomes of energy transfer is crucial for various applications in physics and chemistry. Here, the rovibrational excitation of YO(X 2Σ+) molecules with the collision of Kr and Ne has been studied in the laser-ablation crossed beam and time-sliced ion velocity map imaging setup in combination with the resonance enhanced multiphoton ionization scheme. Significant changes in the angular distribution for different rovibrational excitations of YO molecules are observed with the collision of Kr. The sharp forward distribution for low rovibrational excitation of YO(v' = 0, 1) molecules suggest that the weak attractive potential between Kr and YO is dominant at large impact parameters. Comparatively, the strong sideway distribution for highly rovibrationally excited YO(v' = 1, 2, 3, and 5) is due to rainbow scattering from the stronger attractive potential of Kr···YO at relatively small impact parameters. The more isotropic angular distribution in the highly rovibrationally excited YO(v' = 11) indicates the formation of a short-lived complex. A change in the angular distribution of scattered YO with different rovibrational excitations was also observed in the collisions of Ne. For YO as a heteronuclear diatomic molecule, collisions of the Y- and the O-end of YO with rare gases would affect the contribution of inelastic processes at different impact parameters.

3.
J Phys Chem A ; 127(46): 9654-9660, 2023 Nov 23.
Article in English | MEDLINE | ID: mdl-37937974

ABSTRACT

Spin-orbit coupling plays an important role in chemical reactivity, especially in reactions that require the change of electron spin states. However, it is difficult to measure and analyze the reaction dynamics between spin-orbit splitting states, particularly for splitting states with a small energy difference. In this study, we find that nonreactive scattering of spin-orbit splitting states can provide complementary information that is overlooked in chemical reaction studies. Here, the oxidation reactivities of spin-orbit Al(2P1/2,3/2) states with small energy difference of 112 cm-1 are clearly distinguished in the high rotational AlO(v = 0 and 1, N) products at low collision energy of 507 cm-1 using a laser ablation crossed-beam and time-sliced ion velocity mapping technique, in conjunction with state-selected nonreactive scattering studies. For both the AlO(v = 0 and 1) channels, the spin-orbit relative reactivity σ3/2/σ1/2 increases with the increase of rotational level N of AlO products. However, for AlO(v = 0), the reactivity of the Al(2P3/2) excited state is consistently lower than that of the Al(2P1/2) ground state, whereas for AlO(v = 1), the reactivity of Al(2P3/2) is higher than that of Al(2P1/2) at a higher rotational state. The relative reactivity of spin-orbit split Al(2P) states at different scattering angles shows a more pronounced enhancement of forward scattering relative to side and backward scattering for Al(2P3/2) when a higher rotationally excited AlO is produced. Nonreactive scattering studies of Al(2P) suggest that the Al(2P3/2) state is deexcited to the ground Al(2P1/2) state at the sideways and backward scattering directions, and the deexcitation is supposed to reduce the reactivity of the excited Al(2P3/2) at the corresponding direction.

4.
J Chem Phys ; 159(22)2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38078525

ABSTRACT

In this paper, a global and full-dimensional potential energy surface at the 2A″ ground state for the Al + O2 → AlO + O reaction was constructed, for the first time, based on extensive electronic structure calculations using the doubly hybrid functional XYG3 and potential energy surface fittings by neural networks. Details of the reaction paths have been analyzed. It was found that both two intermediates, the cyclic-AlO2 and the linear-OAlO, were able to dissociate to the AlO + O products, and the isomerization process between these two intermediates was controlled by conical intersections between two 2A″ states. Ro-vibrational state resolved integral cross sections have also been calculated at collision energies from 1.0 to 10.0 kcal/mol. The results support the harpooning mechanism in this metal-oxidant-involved reaction.

5.
BMC Pulm Med ; 23(1): 106, 2023 Mar 31.
Article in English | MEDLINE | ID: mdl-37003996

ABSTRACT

RATIONALE: Chronic obstructive pulmonary disease (COPD) is a complicated chronic inflammatory disease. It is important to investigate the characteristics of acute exacerbation of COPD to develop new therapeutic strategies. OBJECTIVE: This study aimed to determine the relationship between the human beta-defensin-2 (hBD-2) levels and aggravation of COPD. METHODS: We detected the sputum hBD-2 level of 254 patients from Guangzhou, China, for 2 years. The study participants were categorized into the COPD group (n = 203, GOLD 0-4) and the control group (n = 51, 40-79 years old). At baseline, 12th month, and 24th month, we detected the sputum hBD-2 level and levels of cytokines, such as CXCL10, CXCL11, and IFN. RESULTS: At baseline, there were no significant differences in the sputum and serum hBD-2 levels between the patients and the controls. However, the sputum hBD-2 levels of patients who had at least one symptom aggravation over the next 2 years were significantly lower than those of patients without any exacerbations (1130.9 ± 858.4 pg/mL vs. 2103.7 ± 1294.2 pg/mL, respectively; p = 0.001). Nevertheless, there were no statistically significant differences in the sputum hBD-2 levels between patients (no aggravation history) and controls (2084.9 ± 1317.6 pg/mL vs. 2152.5 ± 1251.6 pg/mL, respectively; p = 0.626). We used a logistic regression model to assess the relationship between aggravation and sputum hBD-2 levels. Interestingly, we found that low hBD-2 level (< 1000 pg/mL) was significantly associated with exacerbations. Specifically, patients with low hBD-2 levels were more likely to experience exacerbations in the next 12 months (0.333 vs. 0.117; p = 0.001). Moreover, we compared the hBD-2 levels between controls and patients with GOLD 3-4 and found that participants with bacteria (+) and/or viruses (+) had an association between hBD-2 level and disease severity (p = 0.02). CONCLUSION: Patients at risk of exacerbations are more likely to have lower sputum hBD-2 levels. These results have important implications for future therapies for COPD.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Viruses , beta-Defensins , Humans , Adult , Middle Aged , Aged , Sputum/microbiology , beta-Defensins/therapeutic use , Cytokines
6.
Sensors (Basel) ; 23(1)2023 Jan 02.
Article in English | MEDLINE | ID: mdl-36617108

ABSTRACT

The modulation transfer function (MTF) is an important parameter for performance evaluation of optical imaging systems in photogrammetry and remote sensing; the slanted-edge method is one of the main methods for measuring MTF. To solve the problem of inaccurate edge detection by traditional methods under the conditions of noise and blur, this paper proposes a new method of MTF measurement with a slanted-edge method based on improved Zernike moments, which firstly introduces the Otsu algorithm to automatically determine the Zernike moment threshold for sub-pixel edge detection to precisely locate the edge points, then obtains LSF through edge point projection, ESF sampling point acquisition, smoothing, fitting, taking ESF curve differential and Gaussian fitting, and finally, accurately obtaining MTF by LSF Fourier transform and modulo normalization. Based on simulation experiments and outdoor target experiments, the reliability of the proposed algorithm is verified by the deviations of slanted-edge angle and MTF measurement, and the tolerance degree of edge detection to noise and ambiguity are analyzed. The results show that compared with ISO 12233, OMNI-sine method, Hough transform method and LSD method, this algorithm has the highest edge detection accuracy, the maximum tolerance of noise and ambiguity, and also improves the accuracy of MTF measurement.

7.
Rev Esp Enferm Dig ; 2023 Nov 20.
Article in English | MEDLINE | ID: mdl-37982565

ABSTRACT

A 71-year-old male patient presented to our emergency department with a 1-day history of abdominal pain after an accidental fall. Laboratory test results were as follows: a white blood cell count of 2.32 × 109/L, blood lactate of 3.0 mmol/L, pH 7.30, calcitonin precursor level of 71.09 ng/ml, and creatinine of 115 umol/L. The abdominal CT revealed: portal vein gas accumulation (PVGA) accompanied by a fluid-air level; pneumatosis cystoides intestinalis (PCI) manifested as multiple gas collections within the wall of the lower small intestine. Based on lowered blood pH and elevated lactate levels, there was a high suspicion of small intestinal ischemic necrosis. Subsequent emergency laparotomy and pathological examination confirmed necrosis of the small intestine.

8.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(6): 600-605, 2023 Jun 15.
Article in Zh | MEDLINE | ID: mdl-37382129

ABSTRACT

OBJECTIVES: To study the differences in the clinical features of children with coronavirus disease 2019 (COVID-19) in different age groups during the epidemic of Omicron variant. METHODS: A retrospective analysis was performed on the clinical data of 211 children with COVID-19 who were admitted to the Department of General Pediatrics, Zhongshan People's Hospital, from December 9, 2022 to January 8, 2023. According to their age, they were divided into 4 groups: 1 month-<1 year (n=84), 1-<3 years group (n=64), 3-<5 years (n=29), and ≥5 years (n=34). The above groups were compared in terms of general status, clinical features, ancillary examination results, treatment, and outcome. RESULTS: The children aged <3 years accounted for 70.1% (148/211) of all hospitalized children with COVID-19, and the 3-<5 years group and the ≥5 years group had a significantly higher proportion of children with underlying diseases than the 1 month-<1 year group and the 1-<3 years group (P<0.05). Compared with the other three groups, the 1 month-<1 year group had significantly higher incidence rates of dyspnea, nasal congestion/nasal discharge, diarrhea and significantly lower incidence rates of convulsion and nervous system involvement (P<0.05). Moreover, compared with the other three groups, the 1 month-<1 year group had significantly higher incidence rates of increases in bile acid and creatine kinase isoenzyme and significantly lower incidence rates of decreased platelet count, increased neutrophil percentage, and decreased lymphocyte percentage (P<0.05). The 1 month-<1 year group had a significantly higher incidence rate of mild COVID-19 than the 1-<3 years group and a significantly lower incidence rate of severe/critical COVID-19 than the other three groups (P<0.05). Compared with the other three groups, the 1 month-<1 year group had a significantly higher proportion of children receiving oxygen inhalation therapy (P<0.05). CONCLUSIONS: Children with COVID-19 in different age groups have different clinical features during the epidemic of Omicron variant, especially between the children aged 1 month to <1 year and those aged ≥1 year.


Subject(s)
COVID-19 , Epidemics , Humans , Child , Retrospective Studies , SARS-CoV-2
9.
Sensors (Basel) ; 22(10)2022 May 22.
Article in English | MEDLINE | ID: mdl-35632332

ABSTRACT

Impervious surface as an evaluation indicator of urbanization is crucial for urban planning and management. It is necessary to obtain impervious surface information with high accuracy and resolution to meet dynamic monitoring under rapid urban development. At present, the methods of impervious surface extraction are primarily based on medium-low-resolution images. Therefore, it is of theoretical and application value to construct an impervious surface extraction method that applies to high-resolution satellite images and can solve the shadow misclassification problem. This paper builds an impervious surface extraction model by Bayes discriminant analysis (BDA). The Gaussian prior model is incorporated into the Bayes discriminant analysis to establish a new impervious surface extraction model (GBDA) applicable to high-resolution remote sensing images. Using GF-2 and Sentinel-2 remote sensing images as experimental data, we discuss and analyze the applicability of BDA and GBDA in impervious surface extraction of high-resolution remote sensing images. The results showed that the four methods, SVM, RF, BDA and GBDA, had OA values of 91.26%, 94.91%, 94.64% and 97.84% and Kappa values of 0.825, 0.898, 0.893 and 0.957, respectively, in the extraction results of GF-2. In the results of effective Sentinel-2 extraction, the OA values of the four methods were 87.94%, 91.79%, 92.19% and 93.51% and the Kappa values were 0.759, 0.836, 0.844 and 0.870, respectively. Compared with the support vector machine (SVM), random forest (RF) and BDA methods, GBDA has significantly improved the extraction accuracy. GBDA enhances the robustness and generalization ability of the model and can improve the shadow misclassification phenomenon of high-resolution images. The model constructed in this paper is highly reliable for extracting impervious surfaces from high-resolution remote sensing images, exploring the application value of Bayes discriminant analysis in impervious surface extraction and providing technical support for impervious surface information of high spatial resolution and high quality.


Subject(s)
Remote Sensing Technology , Urbanization , Bayes Theorem , City Planning , Discriminant Analysis
10.
Curr Psychol ; : 1-22, 2022 Feb 05.
Article in English | MEDLINE | ID: mdl-35153458

ABSTRACT

Narrowing the debate about the meaning of wisdom requires two different understandings of wisdom. (a) As action or behaviour, wisdom refers to well-motivated actors achieving an altruistic outcome by creatively and successfully solving problems. (b) As a psychological trait, wisdom refers to a global psychological quality that engages intellectual ability, prior knowledge and experience in a way that integrates virtue and wit, and is acquired through life experience and continued practice. Thus, we propose a two-dimensional theory of wisdom that integrates virtue and wit. Wisdom can be further divided into "humane wisdom" and "natural wisdom" according to the types of capability required. At the same time, we propose that wisdom classification should integrate the views of Sternberg and Wang and be divided into three types: domain-specific wisdom, domain-general wisdom, and omniscient/ overall wisdom. We then discuss three pressing questions about wisdom, and consider five issues important to the future of wisdom research in psychology.

11.
Curr Psychol ; 41(11): 8032-8043, 2022.
Article in English | MEDLINE | ID: mdl-33424207

ABSTRACT

Wisdom views in different cultural contexts are closely connected with the corresponding culture's worldview. Some results are found by comparing the wisdom concepts in Chinese and Western cultures: Firstly, the early wisdom concepts, both in China and the West, contain the elements of intelligence and virtue. Whereas, from the Enlightenment to the Piagetian school, the western concept of wisdom has then shifted to the role of cognition and knowledge; By contrast, the traditional Chinese wisdom concept has been treating wisdom as a virtue. Modern Chinese and western wisdom psychologists are inclined to accept the wisdom meta-theory of "integration of intelligence and virtue". Secondly, both Chinese and the Western philosophy advocate using wisdom to solve real-life problems. Western thinkers focus on practical problems in the material world, i.e. reconciling conflicts between people and the world through understanding and changing the environment. However, Chinese philosophers focus on internal spiritual problems, i.e. improving the individual realm to solve the contradictions inside oneself. Thirdly, both China and the West highlight the comprehensive application of multiple thinking modes. While comparing with the west, which is excelled in using logical and analytical thinking modes and utilizing rational cognition, China is far better at using dialectical and holistic thinking modes and applying intuitive comprehension.

12.
J Res Med Sci ; 27: 3, 2022.
Article in English | MEDLINE | ID: mdl-35342449

ABSTRACT

Background: The adaptive immune system plays a role in the pathogenesis of idiopathic pulmonary fibrosis (IPF) has been reported previously. However, the association between airway and circulating autoantibodies (AAbs) levels is unclear. The aim of this study is to investigate the link between the AAb levels in airway and circulation in stable patients with IPF. Materials and Methods: From June 2016 to March 2017, 21 stable IPF patients and 22 healthy volunteers were recruited. We established Luminex interacting AAbs with bead-antigen complex to detect the immunoglobulin G antibodies levels of ten autoantigens which were matched serum (Se) and sputum (Sp) samples collected from recruited subjects, including Smith (Sm), Anti-ribosomal P antibody (P0), Sjögren syndrome type A antigen (SSA), La/Sjögren syndrome type B antigen (SSB), DNA topoisomerase (Scl-70), histidyl-tRNA synthetase (Jo-1), U1 small nuclear ribonucleoprotein (U1-SnRNP), thyroid peroxidase, Proteinase 3, and Myeloperoxidase. Spearman's rank correlation matrix was applied to explore the associations of Ab profiles between Se and Sp. Results: For IPF patients, Spearman's correlation matrix showed multiple intercorrelations among Sp-AAbs and Sp-AAbs (P < 0.05), while only the levels of AAb against Sm and anti-La in Se were correlated with those Sp-AAb counterparts (P < 0.05). For healthy individuals, only anti-La in Se was associated with those Sp-AAb counterparts (P < 0.05). For IPF patients, there was a positive correlation between carbon monoxide diffusing capacity (DLCO)% predicted and Sp-anti-P0 level (r = 0.464, P = 0.034). Forced vital capacity% predicted was positively correlated with Sp-anti-Scl-70 level (r = 0.466, P = 0.033). Conclusion: Comparing to Se-AAbs, Sp-AAbs are more associated with clinical parameters in the patients with IPF. In order to better understand the role of autoimmunity in the pathogenesis of IPF, detection of Sp-AAbs for local autoimmune responses may be a good choice.

13.
Am J Physiol Lung Cell Mol Physiol ; 320(6): L1169-L1182, 2021 06 01.
Article in English | MEDLINE | ID: mdl-33908260

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a complex and progressive respiratory disease. Autoimmune processes have been hypothesized to contribute to disease progression; however, the presence of autoantibodies in the serum has been variable. Given that COPD is a lung disease, we sought to investigate whether autoantibodies in sputum supernatant would better define pulmonary autoimmune processes. Matched sputum and serum samples were obtained from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study and at the Guangzhou Institute of Respiratory Health (GIRH). Samples were collected from patients with varying severity of COPD, asymptomatic smokers, and healthy control subjects. IgG and IgM autoantibodies were detected in sputum and serum of all subjects in both cohorts using a broad-spectrum autoantigen array. No differences were observed in sputum autoantibodies between COPD and asymptomatic smokers in either cohort. In contrast, 16% of detectable sputum IgG autoantibodies were decreased in subjects with COPD compared to healthy controls in the ADEPT cohort. Compared to asymptomatic smokers, approximately 13% of detectable serum IgG and 40% of detectable serum IgM autoantibodies were differentially expressed in GIRH COPD subjects. Of the differentially expressed specificities, anti-nuclear autoantibodies were predominately decreased. A weak correlation between increased serum IgM anti-tissue autoantibodies and a measure of airspace enlargement was observed. The differential expression of specificities varied between the cohorts. In closing, using a comprehensive autoantibody array, we demonstrate that autoantibodies are present in subjects with COPD, asymptomatic smokers, and healthy controls. Cohorts displayed high levels of heterogeneity, precluding the utilization of autoantibodies for diagnostic purposes.


Subject(s)
Autoantibodies/immunology , Lung/metabolism , Pulmonary Disease, Chronic Obstructive/metabolism , Sputum/metabolism , Case-Control Studies , Disease Progression , Humans , Immunoglobulin G/immunology , Immunoglobulin M/blood , Lung/immunology , Pulmonary Disease, Chronic Obstructive/immunology , Smokers , Smoking/metabolism
14.
Br J Neurosurg ; : 1-6, 2021 May 12.
Article in English | MEDLINE | ID: mdl-33977843

ABSTRACT

BACKGROUND: To investigate the efficacy of percutaneous transforaminal endoscopic discectomy (PTED) in the treatment of patients who were diagnosed with lumbar disc herniation (LDH) with positive nerve root sedimentation sign (NRSS). METHODS: A total of 86 patients who underwent LDH were recruited and divided into NRSS-positive group (n = 49) and NRSS-negative group (n = 37). The visual analog scale (VAS), Japanese Orthopaedic Association (JOA), and Oswestry disability index (ODI) were used to evaluate the low back pain and functional recovery and were compared between the two groups. RESULTS: There were no significant differences in the demographic parameters between the two groups. The average area of the dural sac compression in the NRSS-positive group was significantly higher than that in the NRSS-negative group. Patients with a positive NRSS showed a better low back pain relief than those with a negative NRSS at 1 week and 1 month after surgery. The JOA and ODI in the NRSS-positive group were better than those in the NRSS-negative group at 3 months and 6 months postoperatively. The apparent efficiency of JOA and the excellent and good rate of ODI in the negative group was lower than that in the positive group at 6 months after surgery. CONCLUSIONS: Patients undergoing LDH with a positive NRSS showed better pain relief and functional recovery than those with a negative NRSS. The present study suggested that NRSS might be a valuable sign and associated with better clinical outcomes in patients undergoing LDH with the treatment of PTED.

15.
J Cell Mol Med ; 24(21): 12285-12297, 2020 11.
Article in English | MEDLINE | ID: mdl-32977360

ABSTRACT

Spinal cord injury (SCI) induces both motor and sensory dysfunctions. We wondered whether miR-30b could promote primary sensory neuron (PSN) axon growth in inhibitory microenvironment. The neurite growth was promoted by miR-30b agomir and inhibited by antagomir. MiR-30b targeted and degraded sema3A mRNA. MiR-30b regulated the formation of sema3A-NRP-1-PlexinA1 complex via targeting sema3A. The neurite length was induced by the miR-30b agomir, and the application of sema3A protein could reverse the effect of agomir. GTP-RhoA and ROCK expression were down-regulated by miR-30b. Neurite outgrowth that inhibited by sema3A and the miR-30b antagomir was increased by Y-27632. Agomir promoted neurite growth in NogoA inhibitory conditions, which indicated miR-30b could both enhance neuronal intrinsic regenerative ability and promote neurite growth against inhibitory microenvironment via Sema3A/NRP-1/PlexinA1/RhoA/ROCK axis. The agomir could also regulate Sema3A/NRP-1/PlexinA1/RhoA/ROCK axis in vivo and restore spinal cord sensory conductive function. In conclusion, miR-30b could be a novel target for sensation recovery after SCI.


Subject(s)
MicroRNAs/metabolism , Sensory Receptor Cells/physiology , Signal Transduction , Spinal Cord/physiology , Amides/pharmacology , Animals , Axons/metabolism , Cell Adhesion Molecules/metabolism , Female , Gene Expression Regulation , Guanosine Triphosphate/chemistry , Nerve Regeneration/drug effects , Nerve Tissue Proteins/metabolism , Neuronal Outgrowth , Neurons/metabolism , Neuropilin-1/metabolism , Phosphorylation/drug effects , Pyridines/pharmacology , Rats , Rats, Wistar , Semaphorin-3A/metabolism , Sensation , Signal Transduction/drug effects , Spinal Cord Injuries/genetics , rho GTP-Binding Proteins/metabolism , rho-Associated Kinases/metabolism
16.
J Phys Chem A ; 124(33): 6573-6584, 2020 Aug 20.
Article in English | MEDLINE | ID: mdl-32633965

ABSTRACT

Stereoselectivity or stereorequirement refers to the enhancement of chemical reactivity resulting from the preferential alignment/orientation of the colliding reactants. This concept is deeply embodied in the pre-exponential A-factor of the Arrhenius rate expression or the entropy effect of thermal kinetics in physical chemistry textbooks. To understand its dynamical consequence and seek for its mechanistic origin, two different approaches of either selecting the rotational states of the reactant or aligning/orienting the reactant in the laboratory have traditionally been taken. Due to the experimental challenges, theory is far more advanced than experiment. However, even for the simple atom + diatom reaction, the physical interpretations of the calculated results can sometimes be ambiguous or controversial because of the entangled potential and kinematic factors. In this Feature Article, we try to experimentally tackle the problem for reactions with polyatomic reactants by adopting both approaches in parallel for the same reaction. By comparing the results from the two approaches as well as contrasting them with the analogous reactants-here, a symmetric-top CHD3 versus a spherical-top CH4, deeper physical insights are gained, which paves the road for future studies of complex systems and for establishing a more complete conceptual framework.

17.
Sensors (Basel) ; 20(18)2020 Sep 22.
Article in English | MEDLINE | ID: mdl-32972029

ABSTRACT

Nighttime lights (NTL) create a unique footprint left by human activities, which can reflect the economic index and demographic characteristics of a country or region to some extent. It is of great significance to explore the impact of land features related to social-economic indexes to NTL intensity in urban areas. At present, there are few studies on the impact factors of high-resolution NTL remote sensing data to analyze the influence of NTL intensity variation at a fine scale. In this paper, taking Changchun, China as a case study, we selected the new generation of high spatial resolution (0.92 m) and multispectral bands NTL image JL1-3B data to evaluate the relationship between NTL intensity and related land features such as the normalized difference vegetation index (NDVI), land use types and point of information (POI) at the parcel level, and combined Luojia 1-01 images for comparative analysis. After screening features by the Gini index, 17 variables were selected to establish the best random forest (RF) regression model for the Luojia 1-01 and JL1-3B data, corresponding to out-of-bag (oob) scores of 0.8304 and 0.9054, respectively. The impact of features on NTL was determined by calculating the features contribution. It was found that JL1-3B data perform better on a finer scale and provide more information. In addition, JL1-3B data are less affected by light overflow effect and saturation, and they could provide more accurate information at smaller parcels. Through the impact analysis of land features on the two kinds of NTL data, it is proven that JL1-3B images can be used to study effectively the relationship between NTL and human activities information. This paper aims to establish a regression model between the radiance of two types of NTL data and land features by RF algorithm, to further excavate the main land features that impact radiance according to the feature contribution, and compare the performance of two types of NTL data in regression. The study is expected to provide a reference to the further application of NTL data such as land feature inversion, artificial surface monitoring and evaluation, geographic information point estimation, information mining, etc., and a more comprehensive cognition of land feature impact to urban social-economic indexes from a unique perspective, which can be used to assist urban planning and related decision-making.

18.
Cell Mol Neurobiol ; 39(1): 87-98, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30426336

ABSTRACT

Spinal cord injury (SCI) causes sensory dysfunctions such as paresthesia, dysesthesia, and chronic neuropathic pain. MiR-20a facilitates the axonal outgrowth of the cortical neurons. However, the role of miR-20a in the axonal outgrowth of primary sensory neurons and spinal cord dorsal column lesion (SDCL) is yet unknown. Therefore, the role of miR-20a post-SDCL was investigated in rat. The NF-200 immunofluorescence staining was applied to observe whether axonal outgrowth of dorsal root ganglion (DRG) neurons could be altered by miR-20a or PDZ-RhoGEF modulation in vitro. The expression of miR-20a was quantized with RT-PCR. Western blotting analyzed the expression of PDZ-RhoGEF/RhoA/GAP43 axis after miR-20a or PDZ-RhoGEF was modulated. The spinal cord sensory conduction function was assessed by somatosensory-evoked potentials and tape removal test. The results demonstrated that the expression of miR-20a decreased in a time-dependent manner post-SDCL. The regulation of miR-20a modulated the axonal growth and the expression of PDZ-RhoGEF/RhoA/GAP43 axis in vitro. The in vivo regulation of miR-20a altered the expression of miR-20a-PDZ-RhoGEF/RhoA/GAP43 axis and promoted the recovery of ascending sensory function post-SDCL. The results indicated that miR-20a/PDZ-RhoGEF/RhoA/GAP43 axis is associated with the pathophysiological process of SDCL. Thus, targeting the miR-20a/PDZ-RhoGEF /RhoA/GAP43 axis served as a novel strategy in promoting the sensory function recovery post-SCI.


Subject(s)
GAP-43 Protein/metabolism , Guanine Nucleotide Exchange Factors/metabolism , MicroRNAs/metabolism , Signal Transduction , Spinal Cord Injuries/pathology , Spinal Cord/pathology , Wound Healing , rhoA GTP-Binding Protein/metabolism , Animals , Female , Ganglia, Spinal/metabolism , Ganglia, Spinal/pathology , MicroRNAs/genetics , Neurites/metabolism , Neurites/pathology , Rats, Wistar , Recovery of Function , Sensory Receptor Cells/metabolism , Sensory Receptor Cells/pathology , Spinal Cord Injuries/genetics , Up-Regulation
19.
J Phys Chem A ; 123(17): 3672-3677, 2019 May 02.
Article in English | MEDLINE | ID: mdl-30969120

ABSTRACT

Roaming dynamics is observed in the photodissociation of formic acid (HCOOH) at 230 nm by using the slice imaging method. In combination with rotational state selective (2 + 1) resonance-enhanced multiphoton ionization of the CO fragments, the speed distributions of the CO fragments exhibit a low recoil velocity at low rotational levels of J = 9 and 20, while the velocity distributions of CO at high rotational levels of J = 30 and 48 show a relatively large recoil velocity. The experimental results indicate that the roaming of OH radical should be related with the formation of CO + H2O channel at the present photolysis energy. Unlike the roaming pathways occurring in H2CO that can be described by loose flat potential, our CO speed distribution analysis suggests the presence of a "tight" flat potential in the roaming dynamics of HCOOH molecules.

20.
J Chem Phys ; 149(12): 124303, 2018 Sep 28.
Article in English | MEDLINE | ID: mdl-30278672

ABSTRACT

Nonadiabatic transition between electronic states plays a critical role in the photodissociation of the CX3Y (X = H and F; Y = Cl, Br, and I) system, and the transition probability was considered to be closely related to the X-C-Y bending motion. Hereby the effect of F-C-Br bending vibration on the nonadiabatic transition dynamics is studied by time-sliced ion velocity imaging of Br(2P1/2,3/2) isotopomers produced from the photodissociation of title molecules at two source temperatures, 298 K and 473 K, respectively. At the photolysis wavelength 234 nm, the anisotropy parameter (ß) of the Br(2P3/2) products decreases from 1.3 at 298 K to 0.9 at 473 K, while the ß of Br(2P1/2) remains at almost 2 at two temperatures, indicating the significant effect of bending excitation on the ground channel. Two nonadiabatic dissociation pathways are suggested in the Br(2P3/2) channel. One of them is the parallel excitation from the ground state to the 3 Q 0 state in C3V symmetry, and then transition to the 1 Q 1 state via conical intersection, and the other is the perpendicular excitation to the 3A' state in Cs symmetry and then decomposition along this state in the presence of the avoided crossing between 3A' and 4A' states. Closely related to the F-C-Br bending vibration of CF3Br is the latter transition.

SELECTION OF CITATIONS
SEARCH DETAIL