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1.
IEEE Trans Image Process ; 33: 3200-3211, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38687652

RESUMEN

Person re-identification (ReID) typically encounters varying degrees of occlusion in real-world scenarios. While previous methods have addressed this using handcrafted partitions or external cues, they often compromise semantic information or increase network complexity. In this paper, we propose a new method from a novel perspective, termed as OAT. Specifically, we first use a Transformer backbone with multiple class tokens for diverse pedestrian feature learning. Given that the self-attention mechanism in the Transformer solely focuses on low-level feature correlations, neglecting higher-order relations among different body parts or regions. Thus, we propose the Second-Order Attention (SOA) module to capture more comprehensive features. To address computational efficiency, we further derive approximation formulations for implementing second-order attention. Observing that the importance of semantics associated with different class tokens varies due to the uncertainty of the location and size of occlusion, we propose the Entropy Guided Fusion (EGF) module for multiple class tokens. By conducting uncertainty analysis on each class token, higher weights are assigned to those with lower information entropy, while lower weights are assigned to class tokens with higher entropy. The dynamic weight adjustment can mitigate the impact of occlusion-induced uncertainty on feature learning, thereby facilitating the acquisition of discriminative class token representations. Extensive experiments have been conducted on occluded and holistic person re-identification datasets, which demonstrate the effectiveness of our proposed method.

2.
IEEE Trans Pattern Anal Mach Intell ; 46(5): 3290-3304, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38190688

RESUMEN

This study proposes a set of generic rules to revise existing neural networks for 3D point cloud processing to rotation-equivariant quaternion neural networks (REQNNs), in order to make feature representations of neural networks to be rotation-equivariant and permutation-invariant. Rotation equivariance of features means that the feature computed on a rotated input point cloud is the same as applying the same rotation transformation to the feature computed on the original input point cloud. We find that the rotation-equivariance of features is naturally satisfied, if a neural network uses quaternion features. Interestingly, we prove that such a network revision also makes gradients of features in the REQNN to be rotation-equivariant w.r.t. inputs, and the training of the REQNN to be rotation-invariant w.r.t. inputs. Besides, permutation-invariance examines whether the intermediate-layer features are invariant, when we reorder input points. We also evaluate the stability of knowledge representations of REQNNs, and the robustness of REQNNs to adversarial rotation attacks. Experiments have shown that REQNNs outperform traditional neural networks in both terms of classification accuracy and robustness on rotated testing samples.

3.
Front Immunol ; 12: 677190, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34335576

RESUMEN

Background: Neuromyelitis optica spectrum disorders (NMOSDs) are severe inflammatory diseases mediated mainly by humoral and cellular immunity. Circulating follicular helper T (Tfh) cells are thought to be involved in the pathogenesis of NMOSD, and serum C-X-C motif ligand 13 (CXCL13) levels reflect the effects of Tfh cells on B-cell-mediated humoral immunity. Immune cell and cytokine changes during the dynamic relapsing and remitting processes in NMOSD require further exploration. Patients and methods: Blood samples were collected from 36 patients in acute and recovery phases of NMOSD, 20 patients with other noninflammatory neurological diseases (ONND) and 20 age- and sex-matched healthy volunteers. CD4+CXCR5+PD-1+ Tfh cells were detected by flow cytometry, and serum CXCL13 levels were assessed by enzyme-linked immunosorbent assay (ELISA). Results: The percentage of CD4+CXCR5+PD-1+ Tfh cells was significantly higher during the acute phase than during the recovery phase, and serum CXCL13 levels were significantly higher in patients in the acute and recovery phases of NMOSD than in the ONND and control groups. The Tfh cell percentage was positively correlated with CXCL13 levels, and both were positively correlated with Expanded Disability Status Scale (EDSS) scores and cerebrospinal fluid protein levels in patients with acute NMOSD. Conclusion: Circulating Tfh cells level has the potential to be a biomarker of disease severity.


Asunto(s)
Quimiocina CXCL13/sangre , Neuromielitis Óptica/sangre , Neuromielitis Óptica/inmunología , Índice de Severidad de la Enfermedad , Células T Auxiliares Foliculares/inmunología , Adulto , Anticuerpos/sangre , Anticuerpos/inmunología , Acuaporina 4/inmunología , Biomarcadores/sangre , Antígenos CD4/metabolismo , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunidad Celular , Masculino , Persona de Mediana Edad , Receptor de Muerte Celular Programada 1/metabolismo , Receptores CXCR5/metabolismo
4.
PLoS One ; 16(8): e0255022, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34339435

RESUMEN

Prolyl hydroxylase (PH) enzymes control the degradation of hypoxia-inducible factor (HIF), a transcription factor known to regulate erythropoiesis, angiogenesis, glucose metabolism, cell proliferation, and apoptosis. HIF-PH inhibitors (HIF-PHIs) correct anemia in patients with renal disease and in animal models of anemia and kidney disease. However, the effects of HIF-PHIs on comorbidities associated with kidney disease remain largely unknown. We evaluated the effects of the HIF-PHI FG-2216 in obese ZSF1 (Ob-ZSF1) rats, an established model of kidney failure with metabolic syndrome. Following unilateral nephrectomy (Nx) at 8 weeks of age, rats were treated with 40 mg/kg FG-2216 or vehicle by oral gavage three times per week for up to 18 weeks. FG-2216 corrected blood hemoglobin levels and improved kidney function and histopathology in Nx-Ob-ZSF1 rats by increasing the glomerular filtration rate, decreasing proteinuria, and reducing peritubular fibrosis, tubular damage, glomerulosclerosis and mesangial expansion. FG-2216 increased renal glucose excretion and decreased body weight, fat pad weight, and serum cholesterol in Nx-Ob-ZSF1 rats. Additionally, FG-2216 corrected hypertension, improved diastolic and systolic heart function, and reduced cardiac hypertrophy and fibrosis. In conclusion, the HIF-PHI FG-2216 improved renal and cardiovascular outcomes, and reduced obesity in a rat model of kidney disease with metabolic syndrome. Thus, in addition to correcting anemia, HIF-PHIs may provide renal and cardiac protection to patients suffering from kidney disease with metabolic syndrome.


Asunto(s)
Cardiomiopatías/tratamiento farmacológico , Prolina Dioxigenasas del Factor Inducible por Hipoxia/antagonistas & inhibidores , Obesidad/tratamiento farmacológico , Inhibidores de Prolil-Hidroxilasa/uso terapéutico , Bibliotecas de Moléculas Pequeñas/uso terapéutico , Animales , Biomarcadores/sangre , Cardiomegalia/sangre , Cardiomegalia/complicaciones , Cardiomegalia/fisiopatología , Cardiomiopatías/sangre , Cardiomiopatías/complicaciones , Cardiomiopatías/fisiopatología , Glucosa/metabolismo , Hemoglobinas/metabolismo , Hipertensión/sangre , Hipertensión/complicaciones , Hipertensión/fisiopatología , Prolina Dioxigenasas del Factor Inducible por Hipoxia/metabolismo , Riñón/fisiopatología , Enfermedades Renales/sangre , Enfermedades Renales/complicaciones , Enfermedades Renales/fisiopatología , Masculino , Obesidad/sangre , Obesidad/complicaciones , Obesidad/fisiopatología , Inhibidores de Prolil-Hidroxilasa/farmacología , Ratas , Bibliotecas de Moléculas Pequeñas/farmacología
6.
Trials ; 22(1): 450, 2021 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-34261530

RESUMEN

BACKGROUND: Rheumatoid arthritis (RA) is a common autoimmune disease that severely impacts quality of life. Currently available medications for the treatment of RA have adverse side effects. Emerging evidence suggests that intradermal acupuncture (IA) is feasible and safe for patients, but its application in RA patients has not been examined. Our study aims to explore the efficacy and safety of IA for the treatment of RA. METHODS: This study is a randomised, sham-controlled, patient-outcome assessor-statistician blind trial that aims to evaluate the effects of IA in patients with RA. We will recruit 132 patients aged ≥ 18 years with a diagnosis of RA. Patients will be randomly allocated with a 1:1 ratio to IA or sham IA groups. Both groups will receive basic treatment and nursing routines for RA. The experimental group will receive actual IA treatment, whereas the control group will receive sham IA treatment. All patients will receive one course of treatment (i.e., four consecutive treatment sessions with an intervening 1-day interval). Primary outcomes will be traditional Chinese medicine (TCM) syndromes before and after a treatment course and Health Assessment Questionnaire (HAQ) scores. Secondary outcomes will be disease activity score 28 (DAS28) and levels of serum C-reactive protein (CRP). Outcome measures will be collected pre- and post-treatment. DISCUSSION: This study aims to provide high-quality evidence for the efficacy and safety of IA for treating RA. In addition, the results will provide references for selection of acupoints for other syndromes in clinical practice. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000038028 . Registered on 8 September 2020.


Asunto(s)
Terapia por Acupuntura , Artritis Reumatoide , Terapia por Acupuntura/efectos adversos , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/terapia , Humanos , Medicina Tradicional China , Evaluación de Resultado en la Atención de Salud , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento
7.
Molecules ; 26(6)2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33801847

RESUMEN

Therapeutics that target the virulence of pathogens rather than their viability offer a promising alternative for treating infectious diseases and circumventing antibiotic resistance. In this study, we searched for anti-virulence compounds against Pseudomonas aeruginosa from Chinese herbs and investigated baicalin from Scutellariae radix as such an active anti-virulence compound. The effect of baicalin on a range of important virulence factors in P. aeruginosa was assessed using luxCDABE-based reporters and by phenotypical assays. The molecular mechanism of the virulence inhibition by baicalin was investigated using genetic approaches. The impact of baicalin on P. aeruginosa pathogenicity was evaluated by both in vitro assays and in vivo animal models. The results show that baicalin diminished a plenty of important virulence factors in P. aeruginosa, including the Type III secretion system (T3SS). Baicalin treatment reduced the cellular toxicity of P. aeruginosa on the mammalian cells and attenuated in vivo pathogenicity in a Drosophila melanogaster infection model. In a rat pulmonary infection model, baicalin significantly reduced the severity of lung pathology and accelerated lung bacterial clearance. The PqsR of the Pseudomonas quinolone signal (PQS) system was found to be required for baicalin's impact on T3SS. These findings indicate that baicalin is a promising therapeutic candidate for treating P. aeruginosa infections.


Asunto(s)
Flavonoides/farmacología , Quinolonas/metabolismo , Sistemas de Secreción Tipo III/metabolismo , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Biopelículas/efectos de los fármacos , China , Proteínas de Drosophila/efectos de los fármacos , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Femenino , Flavonoides/metabolismo , Modelos Animales , Infecciones por Pseudomonas/tratamiento farmacológico , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/metabolismo , Percepción de Quorum/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Factores de Transcripción/uso terapéutico , Sistemas de Secreción Tipo III/efectos de los fármacos , Virulencia/efectos de los fármacos , Factores de Virulencia
8.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 35(2): 246-251, 2021 Feb 15.
Artículo en Chino | MEDLINE | ID: mdl-33624482

RESUMEN

OBJECTIVE: To review the causes of Latarjet surgery failure and various revision surgeries, in order to provide the reference for the revision of treatment options for Latarjet surgery failure. METHODS: Literature on the causes of Latarjet surgery failure and revision surgeries was extensively reviewed and analyzed. RESULTS: Latarjet surgery is widely used in clinical practice for recurrent anterior dislocation of shoulder with glenoid defects, especially for the defects of more than 25%. The main reasons for its failure are ununion, bone resorption, graft dislocation, trauma, and graft fracture, etc. The revision surgeries are diverse, the standard treatment has not yet been formed. The revision surgeries include open iliac bone grafting, microscopic Eden-Hybinette surgery, soft tissue reconstruction, open or arthroscopic bone grafting, etc. The differences among the revisions are mainly reflected in grafts, complications, and their costs. CONCLUSION: Latarjet surgery is difficult to operate and requires high technical requirements for the surgeons. It is necessary to continuously improve the surgical technology to reduce the complications related to Latarjet surgery and its revision surgery.


Asunto(s)
Inestabilidad de la Articulación , Luxación del Hombro , Articulación del Hombro , Humanos , Inestabilidad de la Articulación/cirugía , Reoperación , Escápula , Luxación del Hombro/cirugía , Articulación del Hombro/cirugía
9.
ChemSusChem ; 14(9): 2067-2075, 2021 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-33539031

RESUMEN

High-voltage LiNi0.8 Co0.1 Mn0.1 O2 (NCM811)-based Li-ion batteries (LIBs) with enhanced performance can be achieved by properly tailoring the electrolyte systems. Benzoic anhydride (BA) was proposed here as a promising bifunctional electrolyte additive that can not only construct a robust cathode-electrolyte interface (CEI) film on the electrode surface but also capture HF/H2 O in the electrolyte effectively. Compared to the cell without the BA additive, the capacity of Li/NCM811 half-cell with 1.0 wt % BA was increased from 128.5 to 149.6 mAh g-1 after 200 cycles at 1 C between 3.0 and 4.3 V. Even at a higher cut-off voltage of 4.5 V, the BA-containing Li/NCM811 half-cell delivered a capacity retention of 69 % after 200 cycles, much higher than that of the half-cell without the additive (56 %). Both theoretical calculation and experimental results verified that the BA additive could be preferentially oxidized to form a stable interface film with high conductivity that protected the NCM811 cathode and suppressed the decomposition of the electrolyte.

10.
Front Neurol ; 12: 807646, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35095746

RESUMEN

Relapsing-remitting multiple sclerosis (RRMS) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) are inflammatory demyelinating diseases of the central nervous system (CNS). Due to the shared clinical manifestations, detection of disease-specific serum antibody of the two diseases is currently considered as the gold standard for the diagnosis; however, the serum antibody levels are unpredictable during different stages of the two diseases. Herein, peripheral blood single-cell transcriptome was used to unveil distinct immune cell signatures of the two diseases, with the aim to provide predictive discrimination. Single-cell RNA sequencing (scRNA-seq) was conducted on the peripheral blood from three subjects, i.e., one patient with RRMS, one patient with MOGAD, and one patient with healthy control. The results showed that the CD19+ CXCR4+ naive B cell subsets were significantly expanded in both RRMS and MOGAD, which was verified by flow cytometry. More importantly, RRMS single-cell transcriptomic was characterized by increased naive CD8+ T cells and cytotoxic memory-like Natural Killer (NK) cells, together with decreased inflammatory monocytes, whereas MOGAD exhibited increased inflammatory monocytes and cytotoxic CD8 effector T cells, coupled with decreased plasma cells and memory B cells. Collectively, our findings indicate that the two diseases exhibit distinct immune cell signatures, which allows for highly predictive discrimination of the two diseases and paves a novel avenue for diagnosis and therapy of neuroinflammatory diseases.

11.
Sensors (Basel) ; 19(15)2019 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-31357641

RESUMEN

In this study, an ultra-compact humidity sensor based on a double-folded substrate integrated waveguide (SIW) re-entrant cavity was proposed and analyzed. By folding a circular re-entrant cavity twice along its two orthogonally symmetric planes, the designed structure achieved a remarkable size reduction (up to 85.9%) in comparison with a conventional TM010-mode circular SIW cavity. The operating principle of the humidity sensor is based on the resonant method, in other words, it utilizes the resonant properties of the sensor as signatures to detect the humidity condition of the ambient environment. To this end, a mathematical model quantitatively relating the resonant frequency of the sensor and the relative humidity (RH) level was established according to the cavity perturbation theory. The sensing performance of the sensor was experimentally validated in a RH range of 30%-80% by using a humidity chamber. The measured absolute sensitivity of the sensor was calculated to be 135.6 kHz/%RH, and the corresponding normalized sensitivity was 0.00627%/%RH. It was demonstrated that our proposed sensor not only has the merits of compact size and high sensitivity, but also benefits from a high Q-factor and ease of fabrication and integration. These advantages make it an excellent candidate for humidity sensing applications in various fields such as the agricultural, pharmaceutical, and food industries.

12.
Sensors (Basel) ; 18(11)2018 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-30453580

RESUMEN

In this study, a novel non-invasive and contactless microwave sensor using a square substrate integrated waveguide (SIW) re-entrant cavity is proposed for complex permittivity measurement of chemical solutions. The working principle of this sensor is based on cavity perturbation technique, in which the resonant properties of cavity are utilized as signatures to extract the dielectric information of liquid under test (LUT). A winding microfluidic channel is designed and embedded in the gap region of the cavity to obtain a strong interaction between the induced electric field and LUT, thus achieving a high sensitivity. Also, a mathematical predictive model which quantitatively associates the resonant properties of the sensor with the dielectric constant of LUT is developed through numerical analysis. Using this predictive model, quick and accurate extraction of the complex permittivity of LUT can be easily realized. The performance of this sensor is then experimentally validated by four pure chemicals (hexane, ethyl acetate, DMSO and water) together with a set of acetone/water mixtures in various concentrations. Experimental results demonstrate that the designed sensor is capable of characterizing the complex permittivities of various liquids with an accuracy of higher than 96.76% (compared with the theoretical values obtained by Debye relaxation equations), and it is also available for quantifying the concentration ratio of a given binary mixture.

13.
World J Surg Oncol ; 13: 271, 2015 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-26369407

RESUMEN

BACKGROUND: The aim of this study is to evaluate the value of (18)F-FDG uptake features in the diagnosis of solitary pulmonary lesions. METHODS: One hundred thirty-nine patients with solitary pulmonary lesions were divided into full uptake, circular uptake, multi-focus uptake, mild uptake, and no-uptake groups according to the uptake features of (18)F-FDG in solitary pulmonary lesions. The incidence of benign and malignant lesions and the false-positive and false-negative rates in each group were analyzed. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the method using (18)F-FDG uptake features combined with maximum standard uptake value (SUVmax) (SUV method) in the differential diagnosis of solitary pulmonary lesions were evaluated. RESULTS: There were 89 malignant and 50 benign lesions. (1) The malignant incidence of the full uptake group was 84.0% (63/75), and there were significant differences when compared with the other groups except the circular uptake group (16/23) (all P = 0.0001). The benign incidence of the multi-focus and no-uptake groups was 83.3% (10/12) and 82.4% (14/17), respectively, and there were significant differences when compared with the full uptake and the circular uptake groups, respectively (all P < 0.05). The benign incidence of the mild uptake group was 58.3% (7/12), and there were no significant differences when compared with the others except the full uptake group (all P > 0.05). No statistical significance was found between either two of the no-uptake, mild uptake, and multi-focus uptake groups (all P > 0.05). (2) In cases with SUVmax ≥2.5, the false-positive rate in the multi-focus uptake group was 83.3% (10/12), which was significantly higher than in the full uptake (12/75) or circular uptake group (7/23) (all P < 0.05). In cases with SUVmax <2.5, the false-negative rates in the mild and no-uptake groups were 41.7 and 17.6% (P = 0.218). (3) The sensitivity, specificity, accuracy, PPV, and NPV of the method using (18)F-FDG uptake features combined with SUVmax and the single SUV method were 88.7%/91.0%, 62.0%/42.0%, 79.1%/73.4%, 80.6%/73.6%, and 75.6%/72.4%, respectively. CONCLUSIONS: The method using uptake features of (18)F-FDG combined with SUVmax can improve the diagnostic specificity and accuracy of solitary pulmonary lesions. The multi-focus uptake feature maybe a benign sign, which still needs more researches to confirm.


Asunto(s)
Fluorodesoxiglucosa F18/metabolismo , Neoplasias Pulmonares/diagnóstico , Tomografía de Emisión de Positrones/métodos , Radiofármacos/metabolismo , Nódulo Pulmonar Solitario/diagnóstico , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , China/epidemiología , Diagnóstico Diferencial , Femenino , Humanos , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/metabolismo , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Curva ROC , Nódulo Pulmonar Solitario/epidemiología , Nódulo Pulmonar Solitario/metabolismo
14.
IEEE Trans Cybern ; 44(6): 748-60, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23996588

RESUMEN

Principal curves arising as an essential construct in dimensionality reduction and data analysis have recently attracted much attention from theoretical as well as practical perspective. In many real-world situations, however, the efficiency of existing principal curves algorithms is often arguable, in particular when dealing with massive data owing to the associated high computational complexity. A certain drawback of these constructs stems from the fact that in several applications principal curves cannot fully capture some essential problem-oriented facets of the data dealing with width, aspect ratio, width change, etc. Information granulation is a powerful tool supporting processing and interpreting massive data. In this paper, invoking the underlying ideas of information granulation, we propose a granular principal curves approach, regarded as an extension of principal curves algorithms, to improve efficiency and achieve a sound accuracy-efficiency tradeoff. First, large amounts of numerical data are granulated into C intervals-information granules developed with the use of fuzzy C-means clustering and the two criteria of information granulation, which significantly reduce the amount of data to be processed at the later phase of the overall design. Granular principal curves are then constructed by determining the upper and the lower bounds of the interval data. Finally, we develop an objective function using the criteria of information confidence and specificity to evaluate the granular output formed by the principal curves. We also optimize the granular principal curves by adjusting the level of information granularity (the number of clusters), which is realized with the aid of the particle swarm optimization. A number of numeric studies completed for synthetic and real-world datasets provide a useful quantifiable insight into the effectiveness of the proposed algorithm.

15.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 11): o2898, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22219932

RESUMEN

In the title compound, C(14)H(9)N(5)O(10), the two benzene rings are inclined at a dihedral angle of 14.81 (5)°, and the nitro groups are twisted with respect to the benzene rings to which they are attached, making dihedral angles of 57.89 (7), 14.93 (7), 62.58 (7), 2.80 (12) and 22.38 (12)°. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

16.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 11): o3044, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22220056

RESUMEN

The title compound, C(14)H(8)N(6)O(12), is centrosymmetric, the mid-point of the central C-C bond being located on an inversion centre. Two of the three independent nitro groups are disordered over two sites, with a site-occupancy ratio of 0.513 (3):0.487 (3). Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

17.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 11): o3072, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22220080

RESUMEN

In the title compound, C(4)H(5)N(3)O(2), the nitro group is twisted with respect to the imidazole ring by a dihedral angle of 5.60 (2)°. Weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonding is present in the crystal structure.

18.
Zhongguo Zhong Yao Za Zhi ; 34(12): 1489-92, 2009 Jun.
Artículo en Chino | MEDLINE | ID: mdl-19777830

RESUMEN

OBJECTIVE: To study the effect of phosphorus on copper tolerance in Achyranthes bidentata. METHOD: A PVC pipe experiment was conducted to study the interactive effects of phosphorus (P) and copper (Cu), on growth, elemental accumulation and chemical constituents of A. bidentata. Two levels of elemental P were applied at 0 (P0) and 100 ( P100) mg x kg(-1) soil with 5 levels of Cu at 0 (Cu0), 100 (Cu100), 200 (Cu200), 200 (Cu400), 200 (Cu600) mg x kg(-1) soil, respectively. RESULT AND CONCLUSION: The biomass production between different Cu treatments, phosphorus treatment showed significant differences. The biomass reached the maximum value as the concentration of Cu and P was 100 mg x kg(-1). Low concentration of Cu improved the growth of A. bidentata. The growth was blocked as Cu concentration reached 200 mg x kg(-1) in soil, however the contents of oleanolic acid and ecdysterone in roots of A. bidentata had not influenced by Cu. P could improved the copper tolerance in A. bidentata and increased root yield. The Cu concentration in soil of the cultivation bases must be below 200 mg x kg(-1) in order to produce good quality of medicinal material.


Asunto(s)
Achyranthes/metabolismo , Cobre/metabolismo , Fósforo/metabolismo , Contaminantes del Suelo/metabolismo , Achyranthes/crecimiento & desarrollo , Biomasa , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo
19.
Antioxid Redox Signal ; 10(4): 679-89, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18162054

RESUMEN

Abrupt reduction of flow (ischemia) leads to endothelial cell membrane depolarization, NADPH oxidase activation, and reactive oxygen species (ROS) generation in isolated rat and mouse lungs and in flow-adapted endothelial cells in vitro. Here we evaluated the role of PI-3-kinase and rac in activation of endothelial NADPH oxidase. Endothelium of isolated perfused mouse lungs labeled with 2',7'-dichlorodihydrofluorescein (H(2)DCF) or hydroethidine (HE) showed increased ROS generation with ischemia; these results were supported by TBARS measurement in whole-lung homogenate and by in vitro studies using flow-adapted mouse pulmonary microvascular endothelial cells. Ischemia-induced ROS generation in intact lung or isolated cells was blocked by pretreatment with Clostridium difficile toxin B, a rac inhibitor, and by wortmannin or LY294002, PI3 kinase inhibitors. In cells, immunofluorescence and immunoblot after subcellular fractionation showed ischemia-induced translocation of rac, p47(phox), and p67(phox) to the plasma membrane. Increased extracellular K(+) also resulted in rac translocation, providing evidence that this pathway is sensitive to alterations of endothelial cell membrane potential. These results indicate that PI-3-kinase and the small G protein rac are involved in the activation of endothelial cell NADPH oxidase that is associated with the acute loss of shear stress.


Asunto(s)
Células Endoteliales/metabolismo , Enfermedades Pulmonares/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteínas de Unión al GTP rac/metabolismo , Androstadienos/farmacología , Animales , Proteínas Bacterianas/farmacología , Toxinas Bacterianas/farmacología , Membrana Celular/metabolismo , Células Cultivadas , Cromonas/farmacología , Citosol/metabolismo , Células Endoteliales/citología , Fluoresceínas/química , Pulmón/irrigación sanguínea , Pulmón/metabolismo , Pulmón/patología , Ratones , Microscopía Fluorescente , Morfolinas/farmacología , NADPH Oxidasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosfoproteínas/metabolismo , Transducción de Señal , Superóxidos/metabolismo , Wortmanina , Proteínas de Unión al GTP rac/antagonistas & inhibidores , Proteína de Unión al GTP rac1/metabolismo
20.
Microcirculation ; 11(6): 517-26, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15371132

RESUMEN

OBJECTIVE: To investigate the role of voltage-gated Ca2+ channels in Ca2+ influx with flow cessation in flow-adapted rat pulmonary microvascular endothelial cells. METHODS: Cells were evaluated for mRNA and protein levels for major components of the voltage-gated Ca2+ channels. Ca2+ influx with flow cessation and cell membrane potential were measured in real time with fluorescent dyes. Mibefradil and nifedipine were used as inhibitors of Ca2+ channel activity. RESULTS: Voltage-gated Ca2+ channel protein and mRNA for the T-type channel were expressed at a relatively low level in endothelial cells cultured under static conditions and expression was induced significantly during flow adaptation. Flow-adapted but not control cells showed Ca2+ influx during flow cessation that was blocked by mibefradil but not by nifedipine. Ca2+ influx also was blocked by cromakalim, a KATP channel agonist. Cell membrane depolarization with flow cessation was unaffected by mibefradil. CONCLUSIONS: Rat pulmonary microvascular endothelial cells express T-type voltage-gated Ca2+ channels that are induced during adaptation to flow and are responsible for Ca2+ influx that occurs as a result of flow cessation-mediated membrane depolarization.


Asunto(s)
Canales de Calcio Tipo T/metabolismo , Calcio/metabolismo , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Transporte Iónico/efectos de los fármacos , Pulmón/irrigación sanguínea , Animales , Western Blotting , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio Tipo T/genética , Capilares/citología , Cromakalim/farmacología , Endotelio Vascular/citología , Activación del Canal Iónico/efectos de los fármacos , Potenciales de la Membrana/efectos de los fármacos , Mibefradil/farmacología , Nifedipino/farmacología , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio/genética , Canales de Potasio/metabolismo , ARN Mensajero/biosíntesis , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Reología
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