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Generating circularly polarized luminescence (CPL) with simultaneous high photoluminescence quantum yield (PLQY) and dissymmetry factor (glum) is difficult due to usually unmatched electric transition dipole moment (µ) and magnetic transition dipole moment (m) of materials. Herein we tackle this issue by playing a "cascade cationic insertion" trick to achieve strong CPL (with PLQY of ~100 %) in lead-free metal halides with high glum values reaching -2.3×10-2 without using any chiral inducers. Achiral solvents of hydrochloric acid (HCl) and N, N-dimethylformamide (DMF) infiltrate the crystal lattice via asymmetric hydrogen bonding, distorting the perovskite structure to induce the "intrinsic" chirality. Surprisingly, additional insertion of Cs+ cation to substitute partial (CH3)2NH2 + transforms the chiral space group to achiral but the crystal maintains chiroptical activity. Further doping of Sb3+ stimulates strong photoluminescence as a result of self-trapped excitons (STEs) formation without disturbing the crystal framework. The chiral perovskites of indium-antimony chlorides embedded on LEDs chips demonstrate promising potential as CPL emitters. Our work presents rare cases of chiroptical activity of highly luminescent perovskites from only achiral building blocks via spontaneous resolution as a result of symmetry breaking.
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In successive UK clinical trials (UKALL 2003, UKALL 2011) for paediatric acute lymphoblastic leukaemia (ALL), polyethylene glycol-conjugated E. coli L-asparaginase (PEG-EcASNase) 1000 iu/m2 was administered intramuscularly with risk-stratified treatment. In induction, patients received two PEG-EcASNase doses, 14 days apart. Post-induction, non-high-risk patients (Regimens A, B) received 1-2 doses in delayed intensification (DI) while high-risk Regimen C patients received 6-10 PEG-EcASNase doses, including two in DI. Trial substudies monitored asparaginase (ASNase) activity, ASNase-related toxicity and ASNase-associated antibodies (total, 1112 patients). Median (interquartile range) trough plasma ASNase activity (14 ± 2 days post dose) following first and second induction doses and first DI dose was respectively 217 iu/l (144-307 iu/l), 265 iu/l (165-401 iu/l) and 292 iu/l (194-386 iu/l); 15% (138/910) samples showed subthreshold ASNase activity (<100 iu/l) at any trough time point. Older age was associated with lower (regression coefficient -9.5; p < 0.0001) and DI time point with higher ASNase activity (regression coefficient 29.9; p < 0.0001). Clinical hypersensitivity was observed in 3.8% (UKALL 2003) and 6% (UKALL 2011) of patients, and in 90% or more in Regimen C. A 7% (10/149) silent inactivation rate was observed in UKALL 2003. PEG-EcASNase schedule in UKALL paediatric trials is associated with low toxicity but wide interpatient variability. Therapeutic drug monitoring potentially permits optimisation through individualised asparaginase dosing.
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Antineoplásicos , Leucemia-Linfoma Linfoblástico de Células Precursoras , Anticuerpos/uso terapéutico , Antineoplásicos/uso terapéutico , Asparaginasa , Niño , Monitoreo de Drogas , Escherichia coli , Humanos , Polietilenglicoles , Leucemia-Linfoma Linfoblástico de Células Precursoras/inducido químicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológicoRESUMEN
Crop pests and diseases have been the main cause of reduced food production and have seriously affected food security. Therefore, it is very urgent and important to solve the pest problem efficiently and accurately. While traditional neural networks require complete processing of data when processing data, by compressed sensing, only one part of the data needs to be processed, which greatly reduces the amount of data processed by the network. In this paper, a combination of compressed perception and neural networks is used to classify and identify pest images in the compressed domain. A network model for compressed sampling and classification, CSBNet, is proposed to enable compression in neural networks instead of the sensing matrix in conventional compressed sensing (CS). Unlike traditional compressed perception, no reduction is performed to reconstruct the image, but recognition is performed directly in the compressed region, while an attention mechanism is added to enhance feature strength. The experiments in this paper were conducted on different datasets with various sampling rates separately, and our model was substantially less accurate than the other models in terms of trainable parameters, reaching a maximum accuracy of 96.32%, which is higher than the 93.01%, 83.58%, and 87.75% of the other models at a sampling rate of 0.7.
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Compresión de Datos , Compresión de Datos/métodos , Redes Neurales de la Computación , Hojas de la PlantaRESUMEN
In practical electrocardiogram (ECG) monitoring, there are some challenges in reducing the data burden and energy costs. Therefore, compressed sensing (CS) which can conduct under-sampling and reconstruction at the same time is adopted in the ECG monitoring application. Recently, deep learning used in CS methods improves the reconstruction performance significantly and can removes of some of the constraints in traditional CS. In this paper, we propose a deep compressive-sensing scheme for ECG signals, based on modified-Inception block and long short-term memory (LSTM). The framework is comprised of four modules: preprocessing; compression; initial; and final reconstruction. We adaptively compressed the normalized ECG signals, sequentially using three convolutional layers, and reconstructed the signals with a modified Inception block and LSTM. We conducted our experiments on the MIT-BIH Arrhythmia Database and Non-Invasive Fetal ECG Arrhythmia Database to validate the robustness of our model, adopting Signal-to-Noise Ratio (SNR) and percentage Root-mean-square Difference (PRD) as the evaluation metrics. The PRD of our scheme was the lowest and the SNR was the highest at all of the sensing rates in our experiments on both of the databases, and when the sensing rate was higher than 0.5, the PRD was lower than 2%, showing significant improvement in reconstruction performance compared to the comparative methods. Our method also showed good recovering quality in the noisy data.
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Glioma is a malignant primary brain tumor, which can easily lead to death if it is not detected in time. Magnetic resonance imaging is the most commonly used technique to diagnose gliomas, and precise outlining of tumor areas from magnetic resonance images (MRIs) is an important aid to physicians in understanding the patient's condition and formulating treatment plans. However, relying on radiologists to manually depict tumors is a tedious and laborious task, so it is clinically important to investigate an automated method for outlining glioma regions in MRIs. To liberate radiologists from the heavy task of outlining tumors, we propose a fully convolutional network, XY-Net, based on the most popular U-Net symmetric encoder-decoder structure to perform automatic segmentation of gliomas. We construct two symmetric sub-encoders for XY-Net and build interconnected X-shaped feature map transmission paths between the sub-encoders, while maintaining the feature map concatenation between each sub-encoder and the decoder. Moreover, a loss function composed of the balanced cross-entropy loss function and the dice loss function is used in the training task of XY-Net to solve the class unevenness problem of the medical image segmentation task. The experimental results show that the proposed XY-Net has a 2.16% improvement in dice coefficient (DC) compared to the network model with a single encoder structure, and compare with some state-of-the-art image segmentation methods, XY-Net achieves the best performance. The DC, HD, recall, and precision of our method on the test set are 74.49%, 10.89 mm, 78.06%, and 76.30%, respectively. The combination of sub-encoders and cross-transmission paths enables the model to perform better; based on this combination, the XY-Net achieves an end-to-end automatic segmentation of gliomas on 2D slices of MRIs, which can play a certain auxiliary role for doctors in grasping the state of illness.
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Neoplasias Encefálicas , Glioma , Médicos , Humanos , Glioma/diagnóstico por imagen , Neoplasias Encefálicas/diagnóstico por imagen , Entropía , Encéfalo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia MagnéticaRESUMEN
Background: Emerging brain-computer interface (BCI) technology holds promising potential to enhance the quality of life for individuals with disabilities. Nevertheless, the constrained accuracy of electroencephalography (EEG) signal classification poses numerous hurdles in real-world applications. Methods: In response to this predicament, we introduce a novel EEG signal classification model termed EEGGAN-Net, leveraging a data augmentation framework. By incorporating Conditional Generative Adversarial Network (CGAN) data augmentation, a cropped training strategy and a Squeeze-and-Excitation (SE) attention mechanism, EEGGAN-Net adeptly assimilates crucial features from the data, consequently enhancing classification efficacy across diverse BCI tasks. Results: The EEGGAN-Net model exhibits notable performance metrics on the BCI Competition IV-2a and IV-2b datasets. Specifically, it achieves a classification accuracy of 81.3% with a kappa value of 0.751 on the IV-2a dataset, and a classification accuracy of 90.3% with a kappa value of 0.79 on the IV-2b dataset. Remarkably, these results surpass those of four other CNN-based decoding models. Conclusions: In conclusion, the amalgamation of data augmentation and attention mechanisms proves instrumental in acquiring generalized features from EEG signals, ultimately elevating the overall proficiency of EEG signal classification.
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The impact of emotions on health, especially stress, is receiving increasing attention. It is important to provide a non-invasive affect detection system that can be continuously monitored for a long period of time. Multi-sensor fusion strategies can better improve the performance of affect detection models, but there are also problems such as insufficient feature extraction and poor spatiotemporal feature fusion. Therefore, this study proposes a feature-level fusion method based on long short-term memory and one-dimensional convolutional neural network to extract temporal and spatial features of electrocardiogram, electromyogram, electrical activity, temperature, accelerator and response data, respectively, and then fuse them in a summation fashion for affect and stress detection. In particular, we added the tanh activation function before feature fusion, which can improve the model's performance. We used the wearable affect and stress detection dataset to train the model, which includes three different emotion states (neutral, stress, and amusement) for three-class emotion classification with accuracy and F1-scores of 87.82% and 86.68%, respectively. Due to the importance of stress, we also studied binary classification for stress detection, where neutral and amusement were combined as non-stress, with accuracy and F1-scores of 94.9% and 94.98%, respectively. The performance of the proposed model outperforms other control models and can effectively improve the performance of affect and stress detection, and promote medical care, health care and elderly care.
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Electrocardiografía , Redes Neurales de la Computación , Humanos , Electromiografía , TemperaturaRESUMEN
Using proteins in a therapeutic context often requires engineering to modify functionality and enhance efficacy. We have previously reported that the therapeutic antileukemic protein macromolecule Escherichia coli L-asparaginase is degraded by leukemic lysosomal cysteine proteases. In the present study, we successfully engineered L-asparaginase to resist proteolytic cleavage and at the same time improve activity. We employed a novel combination of mutant sampling using a genetic algorithm in tandem with flexibility studies using molecular dynamics to investigate the impact of lid-loop and mutations on drug activity. Applying these methods, we successfully predicted the more active L-asparaginase mutants N24T and N24A. For the latter, a unique hydrogen bond network contributes to higher activity. Furthermore, interface mutations controlling secondary glutaminase activity demonstrated the importance of this enzymatic activity for drug cytotoxicity. All selected mutants were expressed, purified, and tested for activity and for their ability to form the active tetrameric form. By introducing the N24A and N24A R195S mutations to the drug L-asparaginase, we are a step closer to individualized drug design.
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Asparaginasa/química , Asparaginasa/metabolismo , Proliferación Celular , Glutaminasa/metabolismo , Leucemia/patología , Ingeniería de Proteínas , Asparaginasa/genética , Dominio Catalítico , Simulación por Computador , Glutaminasa/química , Glutaminasa/genética , Humanos , Leucemia/enzimología , Leucemia/genética , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Mutación Puntual/genética , Conformación Proteica , Multimerización de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Células Tumorales CultivadasAsunto(s)
Células de la Médula Ósea/metabolismo , Vesículas Extracelulares/metabolismo , Células Madre Mesenquimatosas/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Animales , Antígenos CD19/metabolismo , Línea Celular , Línea Celular Tumoral , Endocitosis , Humanos , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Microscopía Confocal , Trasplante HeterólogoRESUMEN
We developed a murine model of CNS disease to obtain a better understanding of the pathogenesis of CNS involvement in pre-B-cell acute lymphoblastic leukemia (ALL). Semiquantitative proteomic discovery-based approaches identified unique expression of asparaginyl endopeptidase (AEP), intercellular adhesion molecule 1 (ICAM1), and ras-related C3 botulinum toxin substrate 2 (RAC2), among others, in an invasive pre-B-cell line that produced CNS leukemia in NOD-SCID mice. Targeting RAC2 significantly inhibited in vitro invasion and delayed disease onset in mice. Induced expression of RAC2 in cell lines with low/absent expression of AEP and ICAM1 did not result in an invasive phenotype or murine CNS disease. Flow cytometric analysis identified an enriched population of blast cells expressing ICAM1/lymphocyte function associated antigen-1 (LFA-1)/CD70 in the CD10(+)/CD19(+) fraction of bone marrow aspirates obtained from relapsed compared with normal controls and those with primary disease. CD10(+)/CD19(+) fractions obtained from relapsed patients also express RAC2 and give rise to CNS disease in mice. Our data suggest that combinations of processes are involved in the pathogenesis of CNS disease in pre-B-cell ALL, support a model in which CNS disease occurs as a result of external invasion, and suggest that targeting the processes of adhesion and invasion unique to pre-B cells may prevent recurrences within the CNS.
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Neoplasias del Sistema Nervioso Central/fisiopatología , Cisteína Endopeptidasas/genética , Molécula 1 de Adhesión Intercelular/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/fisiopatología , Proteínas de Unión al GTP rac/genética , Animales , Adhesión Celular/fisiología , Línea Celular Tumoral , Membrana Celular/fisiología , Neoplasias del Sistema Nervioso Central/genética , Neoplasias del Sistema Nervioso Central/patología , Niño , Cisteína Endopeptidasas/metabolismo , Modelos Animales de Enfermedad , Regulación Leucémica de la Expresión Génica/fisiología , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones SCID , Invasividad Neoplásica , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/fisiopatología , Proteómica , Proteínas de Unión al GTP rac/metabolismo , Proteína RCA2 de Unión a GTPRESUMEN
Objective.A segmentation method for pre-impact fall detection data is investigated. Specifically, it studies how to partition data segments that are important for classification from continuous inertial sensor data for pre-impact fall detection.Approach.In this study, a trigger-based algorithm combining multi-channel convolutional neural network (CNN) and class activation mapping was proposed to solve the problem of data segmentation. First, a pre-impact fall detection training dataset was established and divided into two parts. For falls, the 1 s data was divided from the peak value of the acceleration signal magnitude vector to the starting direction. For activities of daily living, the cycle segmentation was performed for a 1 s window size. Second, a heat map of the class activation regions of the sensor data was formed using a multi-channel CNN and a class activation mapping algorithm. Finally, the data segmentation strategy was established based on the heat map, the basic law of falls and the real-time requirements.Main results.This method was verified by the SisFall dataset. The obtained segmentation strategy (i.e. to start segmenting a small data segment with a window duration of 325 ms when the acceleration signal magnitude vector is less than 9.217 m s-2) met the real-time requirements for pre-impact fall detection. Moreover, it was suitable for various machine learning algorithms, and the accuracy of the machine learning algorithms used exceeded 94.8%, with the machine learning algorithms verifying the data segmentation strategy.Significance.The proposed method can automatically identify the class activation area, save the computing resources of wearable devices, shorten the duration of segmentation window, and ensure the real-time performance of pre-impact fall detection.
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Actividades Cotidianas , Redes Neurales de la Computación , Algoritmos , Humanos , Aprendizaje AutomáticoRESUMEN
Objective. Overcomplete dictionaries are widely used in compressed sensing (CS) to improve the quality of signal reconstruction. However, dictionary learning under theâ0-norm orâ1-norm constraint inevitably produces dictionary atoms that are negatively correlated with the original signal; meanwhile, when we use a sparse linear combination of dictionary atoms to represent a signal, it is suboptimal for the dictionary atoms to "cancel each other out" by addition and subtraction to approximate the sample. In this paper, we propose a non-negative constrained dictionary learning (NCDL) algorithm to improve the reconstruction performance of CS with electrocardiogram (ECG) signals.Approach.Non-NCDL was divided into an encoding stage and a dictionary learning stage. In the encoding stage, non-negative constraints were imposed on the encoding coefficients and obtained the sparse solution using the alternating direction method of multipliers. At the same time, a penalty term was integrated into the objective function in order to remove small coding coefficients and achieve the effect of sparse coding. In the dictionary learning stage, the block coordinate descent algorithm was utilized to update the dictionary with a view to obtaining an overcomplete dictionary.Results.The performance of the proposed NCDL algorithm was evaluated using the standard MIT-BIH database. Quantitative performance metrics, such as percent root mean square difference (PRD1) and root mean square error, were compared with existing CS approaches to quantify the efficacy of the proposed scheme. For a PRD1 value of 9%, the compression ratio (CR) of the NCDL approach was around 2.78. When CR ranged from 1.05 to 2.78, the proposed NCDL approach outperformed the method of optimal direction, k-means singular value decomposition, and online dictionary learning approaches in ECG signal reconstruction based on CS.Significance.This promising preliminary result demonstrates the capability and feasibility of the proposed bioimpedance method and may open up a new direction for this application. The non-NCDL method proposed in this paper can be used to obtain a sparse basis and improve the performance of CS reconstruction.
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Compresión de Datos , Electrocardiografía , Algoritmos , Bases de Datos Factuales , Electrocardiografía/métodosRESUMEN
The relation between slump flow and yield stress of ultra-high performance concrete (UHPC) mixtures was studied with theoretical analysis and experimentation. The relational expression between slump flow and yield stress of UHPC mixtures was built and then verified with a rheological test. The results showed that the prediction model, as a function of cone geometry of dimensionless slump flow and dimensionless yield stress of the UHPC mixtures, was constructed based on Tresca criteria, considering the geometric relation of morphological characterization parameters before and after slump of the UHPC mixtures. The rationality and applicability of the dimensionless prediction model was verified with a rheological test and a slump test of UHPC mixtures with different dosages of polycarboxylate superplasticizer. With increase in polycarboxylate superplasticizer dosage, yield stress of the two series of UHPC mixtures (large/small binding material consumption) gradually decreased, leading to a gradual increase in slump flow. Based on the prediction model of dimensionless slump flow and dimensionless yield stress, the relational expression between slump flow and yield stress of the UHPC mixtures was built. The comparison result showed that the calculated data was consistent with the experimental data, which provided a new method for predicting yield stress of UHPC mixtures with a slump test.
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The nitrogen nutrition status affects the main factors of rice yield. In traditional rice nitrogen nutrition monitoring methods, most experts enter the farmland to observe leaf color and growth and apply an appropriate amount of nitrogen fertilizer according to the results. However, this method is labor- and time-consuming. To realize automatic rice nitrogen nutrition monitoring, we constructed the Jiangxi rice nitrogen nutrition monitoring model based on a convolution neural network (CNN) using the same region rice canopy image in different generation periods. Our CNN model was evaluated using multiple evaluation criteria (Accuracy, Recall, Precision, and F1 score). The results show that the same CNN model could distinguish the rice nitrogen nutrition status in different periods, which can completely realize the automatic discrimination of nitrogen nutrition status so as to guide the scientific nitrogen application of rice in this area. This will greatly improve the discrimination efficiency of the nitrogen nutrition status and reduce the time and labor cost. The application of the proposed method also proved that the CNN model can be applied in the discrimination of the nitrogen nutrition status. Among CNN models, GoogleNet model proposed a CNN architecture named Inception which can improve the depth of the network and extract higher-level features without changing the amount of calculation of the model. The GoogleNet model achieved the highest accuracy, 95.7%.
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Oryza , Nitrógeno , Estado Nutricional , Fertilizantes , Redes Neurales de la ComputaciónRESUMEN
Objective: Virtual reality (VR) grasping exercise training helps patients participate actively in their recovery and is a critical approach to the rehabilitation of hand dysfunction. This study aimed to explore the effects of active participation and VR grasping on brain function combined with the kinematic information obtained during VR exercises. Methods: The cerebral oxygenation signals of the prefrontal cortex (LPFC/RPFC), the motor cortex (LMC/RMC), and the occipital cortex (LOC/ROC) were measured by functional near-infrared spectroscopy (fNIRS) in 18 young people during the resting state, grasping movements, and VR grasping movements. The EPPlus plug-in was used to collect the hand motion data during simulated interactive grasping. The wavelet amplitude (WA) of each cerebral cortex and the wavelet phase coherence (WPCO) of each pair of channels were calculated by wavelet analysis. The total difference in acceleration difference of the hand in the VR grasping movements was calculated to acquire kinematic characteristics (KCs). The cortical activation and brain functional connectivity (FC) of each brain region were compared and analyzed, and a significant correlation was found between VR grasping movements and brain region activation. Results: Compared with the resting state, the WA values of LPFC, RPFC, LMC, RMC, and ROC increased during the grasping movements and the VR grasping movements, these changes were significant in LPFC (p = 0.0093) and LMC (p = 0.0007). The WA values of LMC (p = 0.0057) in the VR grasping movements were significantly higher than those in the grasping movements. The WPCO of the cerebral cortex increased during grasping exercise compared with the resting state. Nevertheless, the number of significant functional connections during VR grasping decreased significantly, and only the WPCO strength between the LPFC and LMC was enhanced. The increased WA of the LPFC, RPFC, LMC, and RMC during VR grasping movements compared with the resting state showed a significant negative correlation with KCs (p < 0.001). Conclusion: The VR grasping movements can improve the activation and FC intensity of the ipsilateral brain region, inhibit the FC of the contralateral brain region, and reduce the quantity of brain resources allocated to the task. Thus, ordered grasping exercises can enhance active participation in rehabilitation and help to improve brain function.
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In order to investigate the feasibility of using rice critical nitrogen concentration as a nitrogen nutrition diagnosis index, a two-year positioning field gradient experiment using four rice varieties and four nitrogen levels (0, 75, 150, 225 kg·ha-1 for early rice; 0, 90, 180, 270 kg·ha-1 for late rice) was conducted for early and late rice. The critical dilution curves (Nc%) of the double-cropped rice based on leaf dry matter (LDM) were constructed and verified using the field data. Two critical nitrogen dilution curves and nitrogen nutrition indexes (NNI) of rice LDM were constructed for early rice [Nc% = 2.66LDM-0.79, R2 = 0.88, NNI ranged between 0.29-1.74, and the average normalized root mean square error (n-RMSE = 19.35%)] and late rice [Nc% = 7.46LDM-1.42, R2 = 0.91, NNI was between 0.55-1.53, and the average (n-RMSE = 15.14%)]. The relationship between NNI and relative yield was a quadratic polynomial equation and suggested that the optimum nitrogen application rate for early rice was sightly smaller than 150 kg·ha-1, and that for late rice was about 180 kg·ha-1. The developed critical nitrogen concentration dilution curves, based on leaf dry matter, were able to diagnose nitrogen nutrition in the double-cropped rice region.
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Nitrógeno/análisis , Oryza/crecimiento & desarrollo , Simulación por Computador , Productos Agrícolas/química , Productos Agrícolas/crecimiento & desarrollo , Oryza/química , Hojas de la Planta/química , Hojas de la Planta/crecimiento & desarrolloRESUMEN
B7-H1 (PD-L1) is a B7-related protein that inhibits T-cell responses. B7-H1 participates in the immunoescape of cancer cells and is also involved in the long-term persistence of leukemic cells in a mouse model of leukemia. B7-H1 can be constitutively expressed by cancer cells, but is also induced by various stimuli. Therefore, we examined the constitutive and inducible expression of B7-H1 and the consequences of this expression in human acute myeloid leukemia (AML). We analyzed B7-H1 expression in a cohort of 79 patients with AML. In addition, we studied blast cells after incubation with interferon-gamma or toll-like receptors (TLR) ligands. Finally, we evaluated functionality of cytotoxic T-cell activity against blast cells. Expression of B7-H1 upon diagnosis was high in 18% of patients. Expression of TLR2, 4 and 9 was detected in one-third of AML samples. Expression of TLR2 and TLR4 ligands or IFN-γ induced by B7-H1 was found to protect AML cells from CTL-mediated lysis. Spontaneous B7-H1 expression was also found to be enhanced upon relapse in some patients. MEK inhibitors, including UO126 and AZD6244, reduced B7-H1 expression and restored CTL-mediated lysis of blast cells. In AML, B7-H1 expression by blasts represents a possible immune escape mechanism. The inducibility of B7-H1 expression by IFN-γ or TLR ligands suggests that various stimuli, either produced during the immune response against leukemia cells or released by infectious microorganisms, could protect leukemic cells from T cells. The efficacy of MEK inhibitors against B7-H1-mediated inhibition of CTLs suggests a possible cancer immunotherapy strategy using targeted drugs.
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Antígenos CD/fisiología , Crisis Blástica/inmunología , Interferón gamma/fisiología , Leucemia Mieloide Aguda/patología , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Linfocitos T Citotóxicos/inmunología , Receptores Toll-Like/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Antígeno B7-H1 , Línea Celular Tumoral , Citotoxicidad Inmunológica , Femenino , Humanos , Péptidos y Proteínas de Señalización Intracelular/fisiología , Masculino , Persona de Mediana Edad , Fosfatidilinositol 3-Quinasas/fisiología , Proteínas Serina-Treonina Quinasas/fisiología , Serina-Treonina Quinasas TORRESUMEN
In the title complex, [Co(C(13)H(14)N(3)O(3))(2)(H(2)O)(2)], the Co(II) atom has a distorted octa-hedral coordination, formed by four N atoms from two (±)-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)nicotinate ligands and two O atoms from two water mol-ecules. Intra-molecular N-Hâ¯O and O-Hâ¯O hydrogen bonds are present. In the crystal, inter-molecular O-Hâ¯O hydrogen bonds link the complex mol-ecules into a chain along [010].
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In the title compound, [Mn(C(13)H(14)N(3)O(3))(2)(H(2)O)(2)], the Mn(II) ion is coordinated by four N atoms from two (±)-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)nicotinate ligands and two water mol-ecules in a distorted octa-hedral environment. Inter-molecular O-Hâ¯O hydrogen bonds lead to a chain along [010]. Intra-molecular N-Hâ¯O and O-Hâ¯O hydrogen bonds are observed.
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The Zn atom in the title compound, [Zn(C(7)H(5)O(2))(2)(C(12)H(8)N(2))(H(2)O)], is five-coordinate in a distorted trigonal-bipyramidal coordination environment involving two O atoms of two monodentate benzoates, two N atoms of a 1,10-phenanthroline mol-ecule and one O atom of a water mol-ecule. The axial positions are occupied by a carboxyl-ate O atom from the benzoate ligand and an N atom from the 1,10-phenanthroline ligand [N-Zn-O = 146.90â (7)°]. The water mol-ecule forms an intra-molecular O-Hâ¯O hydrogen bond; an inter-molecular O-Hâ¯O hydrogen bond gives rise to a dimer.