Robust object recognition is a crucial skill for robots operating autonomously in real world environments. Range sensors such as LiDAR and RGBD cameras are increasingly found in modern robotic ...systems, providing a rich source of 3D information that can aid in this task. However, many current systems do not fully utilize this information and have trouble efficiently dealing with large amounts of point cloud data. In this paper, we propose VoxNet, an architecture to tackle this problem by integrating a volumetric Occupancy Grid representation with a supervised 3D Convolutional Neural Network (3D CNN). We evaluate our approach on publicly available benchmarks using LiDAR, RGBD, and CAD data. VoxNet achieves accuracy beyond the state of the art while labeling hundreds of instances per second.
This paper poses object category detection in images as a type of 2D-to-3D alignment problem, utilizing the large quantities of 3D CAD models that have been made publicly available online. Using the ..."chair" class as a running example, we propose an exemplar-based 3D category representation, which can explicitly model chairs of different styles as well as the large variation in viewpoint. We develop an approach to establish part-based correspondences between 3D CAD models and real photographs. This is achieved by (i) representing each 3D model using a set of view-dependent mid-level visual elements learned from synthesized views in a discriminative fashion, (ii) carefully calibrating the individual element detectors on a common dataset of negative images, and (iii) matching visual elements to the test image allowing for small mutual deformations but preserving the viewpoint and style constraints. We demonstrate the ability of our system to align 3D models with 2D objects in the challenging PASCAL VOC images, which depict a wide variety of chairs in complex scenes.
Osteosarcoma (OS) remains a dismal malignancy in children and young adults, with poor outcome for metastatic and recurrent disease. Immunotherapies in OS are not as promising as in some other cancer ...types due to intra-tumor heterogeneity and considerable off-target expression of the potentially targetable proteins. Here we show that chimeric antigen receptor (CAR) T cells could successfully target an isoform of alkaline phosphatase, ALPL-1, which is highly and specifically expressed in primary and metastatic OS. The target recognition element of the second-generation CAR construct is based on two antibodies, previously shown to react against OS. T cells transduced with these CAR constructs mediate efficient and effective cytotoxicity against ALPL-positive cells in in vitro settings and in state-of-the-art in vivo orthotopic models of primary and metastatic OS, without unexpected toxicities against hematopoietic stem cells or healthy tissues. In summary, CAR-T cells targeting ALPL-1 show efficiency and specificity in treating OS in preclinical models, paving the path for clinical translation.
Activation of the mineralocorticoid receptor (MR) in the heart is considered to be a cardiovascular risk factor. MR activation leads to heart hypertrophy and arrhythmia. In ventricular ...cardiomyocytes, aldosterone induces a profound remodeling of ion channel expression, in particular, an increase in the expression and activity of T-type voltage-gated calcium channels (T-channels). The molecular mechanisms immediately downstream from MR activation, which lead to the increased expression of T-channels and, consecutively, to an acceleration of spontaneous cell contractions in vitro, remain poorly investigated. Here, we investigated the putative role of a specific microRNA in linking MR activation to the regulation of T-channel expression and cardiomyocyte beating frequency. A screening assay identified microRNA 204 (miR-204) as one of the major upregulated microRNAs after aldosterone stimulation of isolated neonatal rat cardiomyocytes. Aldosterone significantly increased the level of miR-204, an effect blocked by the MR antagonist spironolactone. When miR-204 was overexpressed in isolated cardiomyocytes, their spontaneous beating frequency was significantly increased after 24 h, like upon aldosterone stimulation, and messenger RNAs coding T-channels (CaV3.1 and CaV3.2) were increased. Concomitantly, T-type calcium currents were significantly increased upon miR-204 overexpression. Specifically repressing the expression of miR-204 abolished the aldosterone-induced increase of CaV3.1 and CaV3.2 mRNAs, as well as T-type calcium currents. Finally, aldosterone and miR-204 overexpression were found to reduce REST-NRSF, a known transcriptional repressor of CaV3.2 T-type calcium channels. Our study thus strongly suggests that miR-204 expression stimulated by aldosterone promotes the expression of T-channels in isolated rat ventricular cardiomyocytes, and therefore, increases the frequency of the cell spontaneous contractions, presumably through the inhibition of REST-NRSF protein.
Bio-nanocapsules (BNCs) are a hollow nanoparticle consisting of about 100-nm liposome (LP) embedding about 110 molecules of hepatitis B virus (HBV) surface antigen (HBsAg) L protein as a ...transmembrane protein. Owing to the human hepatocyte-recognizing domains on the N-terminal region (pre-S1 region), BNCs have recently been shown to attach and enter into human hepatic cells using the early infection mechanism of HBV. Since BNCs could form a complex with an LP containing various drugs and genes, BNC–LP complexes have been used as a human hepatic cell-specific drug and gene-delivery system in vitro and in vivo. However, the role of BNCs in cell entry and intracellular trafficking of payloads in BNC–LP complexes has not been fully elucidated. In this study, we demonstrate that low pH-dependent fusogenic activity resides in the N-terminal part of pre-S1 region (NPLGFFPDHQLDPAFG), of which the first FF residues are essential for the activity, and which facilitates membrane fusion between LPs in vitro. Moreover, BNC–LP complexes can bind human hepatic cells specifically, enter into the cells via clathrin-mediated endocytosis, and release their payloads mostly into the cytoplasm. Taken together, the BNC portion of BNC–LP complexes can induce membrane fusion between LPs and endosomal membranes under low pH conditions, and thereby facilitate the endosomal escape of payloads. Furthermore, the fusogenic domain of the pre-S1 region of HBsAg L protein may play a pivotal role in the intracellular trafficking of not only BNC–LP complexes but also of HBV.
BNC–LP complexes bind to HSPG, enter cells by high-affinity receptor, fuse with endosomal membrane by the pH-dependent fusogenic pre-S1 domain, and then release their payloads into the cytoplasm. Display omitted
Este artículo explica la función comunicativa de la variación léxica y construccional en los predicados verbales que elaboran la cuantificación de cifra o volumen de negocio en las noticias de ...economía. Las ocurrencias se analizan desde la perspectiva de la Lingüística Cognitiva y los resultados muestran que el contenido informativo está determinado por: (i) la categoría semántica del verbo, (ii) el número de complementos de medida, (iii) la posición de la expresión de medida en el predicado, (iv) la categoría léxica de la expresión de medida, y (iv) el uso de modificadores adverbiales. La conclusión es que los predicados verbales de cantidad representan diversos constructos y que la función comunicativa de la variación es la de representar las preferencias del emisor con respecto a la selección, la prominencia y el nivel de especificidad de la información.
Exciton Circular Dichroism in Channelrhodopsin Pescitelli, Gennaro; Kato, Hideaki E; Oishi, Satomi ...
The journal of physical chemistry. B,
10/2014, Letnik:
118, Številka:
41
Journal Article
Recenzirano
Channelrhodopsins (ChRs) are of great interest currently because of their important applications in optogenetics, the photostimulation of neurons. The absorption and circular dichroism (CD) spectra ...of C1C2, a chimera of ChR1 and ChR2 of Chlamydomonas reinhardtii, have been studied experimentally and theoretically. The visible absorption spectrum of C1C2 shows vibronic fine structure in the 470 nm band, consistent with the relatively nonpolar binding site. The CD spectrum has a negative band at 492 nm (Δεmax = −6.17 M–1 cm–1) and a positive band at 434 nm (Δεmax = +6.65 M–1 cm–1), indicating exciton coupling within the C1C2 dimer. Time-dependent density functional theory (TDDFT) calculations are reported for three models of the C1C2 chromophore: (1) the isolated protonated retinal Schiff base (retPSB); (2) an ion pair, including the retPSB chromophore, two carboxylate side chains (Asp 292, Glu 162), modeled by acetate, and a water molecule; and (3) a hybrid quantum mechanical/molecular mechanical (QM/MM) model depicting the binding pocket, in which the QM part consists of the same ion pair as that in (2) and the MM part consists of the protein residues surrounding the ion pair within 10 Å. For each of these models, the CD of both the monomer and the dimer was calculated with TDDFT. For the dimer, DeVoe polarizability theory and exciton calculations were also performed. The exciton calculations were supplemented by calculations of the coupling of the retinal transition with aromatic and peptide group transitions. For the dimer, all three methods and three models give a long-wavelength C2-axis-polarized band, negative in CD, and a short-wavelength band polarized perpendicular to the C2 axis with positive CD, differing in wavelength by 1–5 nm. Only the retPSB model gives an exciton couplet that agrees qualitatively with experiment. The other two models give a predominantly or solely positive band. We further analyze an N-terminal truncated mutant because it was assumed that the N-terminal domain has a crucial role in the dimerization of ChRs. However, the CD spectrum of this mutant has an exciton couplet comparable to that of the wild-type, demonstrating that it is dimeric. Patch-clamp experiments suggest that the N-terminal domain is involved in protein stabilization and channel kinetics rather than dimerization or channel activity.
The orientation of sensing molecules on solid phase biosensors has to be optimized to facilitate efficient binding of analytes. Since conventional observation methods (e.g., electron microscopy, ...atomic force microscopy, time-of-flight secondary ion mass spectrometry) require exaggerated machines and possess insufficient resolution for single molecule analyses, functional assays based on the reactivity to analytes have thus far been used for this optimization. However, it is not clear whether these assays can judge whether sensing molecules are fixed in an oriented-immobilization manner or not. Here, we describe that bio-nanocapsules of about 30 nm diameter, displaying approximately 120 molecules of a tandem form of the immunoglobulin (Ig) G Fc-binding Z domain (ZZ-BNCs), can discriminate between the Fc regions of IgGs fixed in an oriented-immobilization manner and those fixed randomly, thus facilitating the evaluation of the orientation of IgGs in immunosensors. Furthermore, in sandwich immunoassays, ZZ-BNCs can bind specifically to detection-IgGs fixed in an oriented-immobilization manner by antigen-capture IgG complexes, rather than to capture-IgGs fixed randomly onto a solid phase, allowing the simultaneous use of the same IgG as capture- and detection-IgGs. Thus, we demonstrate that ZZ-BNCs are a unique probe for evaluating the orientation of IgGs on a solid phase.
AtHMA1 Is a Thapsigargin-sensitive Ca2+/Heavy Metal Pump Moreno, Ignacio; Norambuena, Lorena; Maturana, Daniel ...
Journal of biological chemistry/The Journal of biological chemistry,
04/2008, Letnik:
283, Številka:
15
Journal Article
Recenzirano
Odprti dostop
The Arabidopsis thaliana AtHMA1 protein is a member of the PIB-ATPase family, which is implicated in heavy metal transport. However, sequence analysis reveals that AtHMA1 possesses a predicted stalk ...segment present in SERCA (sarcoplasmic/endoplasmic reticulum Ca2+ ATPase)-type pumps that is involved in inhibition by thapsigargin. To analyze the ion specificity of AtHMA1, we performed functional complementation assays using mutant yeast strains defective in Ca2+ homeostasis or heavy metal transport. The heterologous expression of AtHMA1 complemented the phenotype of both types of mutants and, interestingly, increased heavy metal tolerance of wild-type yeast. Biochemical analyses were performed to describe the activity of AtHMA1 in microsomal fractions isolated from complemented yeast. Zinc, copper, cadmium, and cobalt activate the ATPase activity of AtHMA1, which corroborates the results of metal tolerance assays. The outcome establishes the role of AtHMA1 in Cd2+ detoxification in yeast and suggests that this pump is able to transport other heavy metals ions. Further analyses were performed to typify the active Ca2+ transport mediated by AtHMA1. Ca2+ transport displayed high affinity with an apparent Km of 370 nm and a Vmax of 1.53 nmol mg–1 min–1. This activity was strongly inhibited by thapsigargin (IC50 = 16.74 nm), demonstrating the functionality of its SERCA-like stalk segment. In summary, these results demonstrate that AtHMA1 functions as a Ca2+/heavy metal pump. This protein is the first described plant P-type pump specifically inhibited by thapsigargin.
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