Fusing Depth and Silhouette for Scanning Transparent Object with RGB-D Sensor

3D reconstruction based on structured light or laser scan has been widely used in industrial measurement, robot navigation, and virtual reality. However, most modern range sensors fail to scan transparent objects and some other special materials, of which the surface cannot reflect back the accurate depth because of the absorption and refraction of light. In this paper, we fuse the depth and silhouette information from an RGB-D sensor (Kinect v1) to recover the lost surface of transparent objects. Our system is divided into two parts. First, we utilize the zero and wrong depth led by transparent materials from multiple views to search for the 3D region which contains the transparent object. Then, based on shape from silhouette technology, we recover the 3D model by visual hull within these noisy regions. Joint Grabcut segmentation is operated on multiple color images to extract the silhouette. The initial constraint for Grabcut is automatically determined. Experiments validate that our approach can improve the 3D model of transparent object in real-world scene. Our system is time-saving, robust, and without any interactive operation throughout the process

Optimization with a Genetic Algorithm for Multilayer Electromagnetic Wave Absorption Cement Mortar Filled with Expended Perlite

Abstract: Due to the complexity of the design of multilayer electromagnetic (EM) wave absorbing materials, it is difficult to establish the relationship between material parameters (type and filling ratios) and EM properties using traditional trial and error methods. Based on the measured EM parameters within a few materials and Boltzmann mixing theory, a database of EM parameters was thereafter built up. In this study, the genetic algorithm (GA) was used to design the multilayer wave-absorbing cement mortar. In order to verify this method, a multilayer mortar was fabricated and measured. The simulated and measured results are well consistent, which convincingly verifies computer-aided design. In addition, the optimized result expresses that the first layer as a matching layer guides EM waves into the interior of the material, while the other layers as absorption layers attenuate EM waves. The multilayer material may not meet the impedance gradient principle but still exhibits better EM wave absorption performance. The reflection loss (RL) of all optimized three layer sample is below –6.89 dB in the full frequency band and the minimum RL is –26.21 dB. This composite absorbing material and the GA method provide more design ideas for the design of future cement-based wave-absorbing materials and save a lot of time and material cost

Volumeter: 3D human body parameters measurement with a single Kinect

3D human body parameters measurement is a challenging task due to two main reasons: (i) it is difficult to reconstruct 3D human model due to flexible deformation of non‐rigid body during images capturing process and (ii) there lies a gap between 3D model and body parameters. To address these two issues, a 3D human body parameters measurement system is represented. With the object freely spinning in front of a Kinect, body parameters are calculated. To reduce registration errors caused by body deformation while rotating, a piecewise tracking and mapping algorithm based on KinectFusion framework is proposed. Then model–model iterative closest point and non‐rigid constraints are introduced to optimise alignments and disambiguate different surfaces caused by aliasing in the piecewise strategy. Finally, a novel method is presented to measure the volume and perimeter of human body with the truncated signed distance function values of voxels. Extensive experimental results show that the proposed method achieves comparable accuracy to the state of the arts, and the error of volume and perimeter measurements are 2.0 and 5.8%, respectively

Hepatitis D: advances and challenges

Hepatitis D virus (HDV) infection causes the most severe form of viral hepatitis with rapid progression to cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Although discovered > 40 years ago, little attention has been paid to this pathogen from both scientific and public communities. However, effectively combating hepatitis D requires advanced scientific knowledge and joint efforts from multi-stakeholders. In this review, we emphasized the recent advances in HDV virology, epidemiology, clinical feature, treatment, and prevention. We not only highlighted the remaining challenges but also the opportunities that can move the field forward

Heterologous expression of mlrA gene originated from Novosphingobium sp THN1 to degrade microcystin-RR and identify the first step involved in degradation pathway

Information on the catalytic role of mlrA gene-encoded enzyme (MlrA) in microcystin-RR (MC-RR) biodegradation was limited. This study succeeded in expressing mlrA homolog of Novosphingobium sp. THN1 in heterologous host for the first time, by constructing a recombinant bacterium. Mass spectrometric analysis showed that the recombinant MlrA hydrolyzed MC-RR into linear intermediate product by cleaving the peptide bond between Adda and arginine residue, greatly detoxifying MC-RR. This finding clearly manifested that the MlrA homolog of THN1 strain possesses its original catalytic function, and ring-opening constituted the first step in MC-RR biodegradation pathway of THN1 strain. Moreover, MC-RR degradation by intact recombinant cells and cell-free crude enzyme (CE) from recombinant was compared. Results exhibited that intact recombinant was able to degrade 20 mu g mL(-1) MC-RR more quickly than CE, with the maximum rate of 9.22 mu g mL(-1) h(-1) in the first 8 h. Thus, this study provided new insights on the catalytic activity and roles of MIrA originated from THN1 strain in MC-RR biodegradation process, which lay a foundation for efficiently removing and detoxifying MC-RR, and exploring downstream steps in MC-RR biodegradation pathway of THN1 strain. (C) 2017 Elsevier Ltd. All rights reserved.</p

Performance Analysis and Sensor-Target Geometry Optimization for TOA and TDOA-Based Hybrid Source Localization Method

Currently, the performance analysis of positioning algorithms and optimization of ground station deployment schemes are predominantly based on pure TOA or TDOA measurement information, and the relevant theoretical analysis is primarily the geometric analysis of optimal station deployment for fixed point targets, with few placement ranges and amount of station constraints. In practice, however, there are typically several measurements from TOA and TDOA stations, with a focus on positioning precision within a certain region or line trajectory, as well as the necessity for constraints on the ground station placement range. This paper proposes an efficient method for hybrid source localization using TOA and TDOA measurement information, establishes a mathematical model for hybrid source localization based on TOA and TDOA measurement information, derives and simulates the Gauss–Newton iterative localization algorithm with the least squares criterion, and performs a theoretical analysis of the least squares error and CRLB boundary to improve the accuracy of target localization in the aforementioned scenarios. Taking the average CRLB value of target line trajectory positioning error as the objective function, the ground station placement scheme of TOA- and TDOA-receiving sensors is optimized by utilizing a Genetic Algorithm with strong global optimization capability under the constraints of station placement range and station quantities, and a station placement geometry with better performance than typical station placement is obtained. Meanwhile, we summarize the general placement principles for TOA and TDOA hybrid source localization of target line trajectories

A rare case of primary pulmonary diffuse large B cell lymphoma with CD5 positive expression

Primary pulmonary diffuse large B-cell lymphoma (PPDLBCL) is extremely rare. Its clinical symptoms and signs are nonspe cific, and imaging features also have not yet been well-defined. Further description is important for the diagnosis and treatment of PPDLBCL. Herein, we reported a case of a patient who suffered from bilateral chest pain and dyspnea. Computed tomography (CT) of chest demonstrated bilateral lung mass, consolidations and reverse halo sign, while consolidations and reverse halo sign are uncommon according to previous reports. Tissue samples were taken by CT guided needle biopsy. The histological samples showed PPDLBCL. This case was special in view of positive expression of CD5. After the case was treated by cyclophosphamide pirarubicin vindesine dexamethasone (CHOP) chemotherapy for six courses, her clinical symptoms were partially alleviated, while CT showed progression disease. This case report highlights different imaging features and characteristics of molecular biology, and reviews study progress of PPDLBCL

Frequency and molecular basis of CD36 deficiency among platelet donors in Kunming, China

CD36 is a multifunctional receptor expressed on the surface of many cell types. Among healthy individuals, CD36 may be absent on platelets and monocytes (type I deficiency) or platelets alone (type II deficiency). However, the exact molecular mechanisms underlying CD36 deficiency remain unclear. In this study, we aimed to identify individuals with CD36 deficiency and investigate the molecular basis underlying it. Blood samples were collected from platelet donors at Kunming Blood Center. Platelets and monocytes were isolated and CD36-expression levels were analyzed using flow cytometry. DNA from whole blood and mRNA isolated from monocytes and platelets of individuals with CD36 deficiency were analyzed using polymerase chain reaction (PCR) testing. The PCR products were cloned and sequenced. Among the 418 blood donors,7 (1.68%) were CD36 deficient: 1 (0.24%) with type I deficiency and 6(1.44%) with type II deficiency. Six heterozygous mutations occurred, including c.268C>T (in type I individuals), c.120 + 1 G>T, c.268C>T, c.329_330del/AC, c.1156 C>T, c.1163A>C, and c.1228_1239del/ATTGTGCCTATT (in type II individuals). Mutations were not detected in one type II individual . At the cDNA level, only mutant, but not wild-type, transcripts were detected in the platelets and monocytes of type I individual. In type II individuals, only mutant transcripts were found in platelets, whereas monocytes possessed wild-type and mutant transcripts. Interestingly, only alternative splicing transcripts were observed in the individual without mutation. We report the incidence rates of type I and II CD36 deficiencies among platelet donors in Kunming. Molecular genetic analyses of DNA and cDNA demonstrated that homozygous mutations on the cDNA level in platelets and monocytes or platelets alone identified type I and II deficiencies, respectively. Furthermore, alternatively spliced products also potentially contribute to the mechanism of CD36 deficiency

Long-lifetime, potentially low-cost anthraquinone flow battery chemistry developed from study of effects of water-solubilizing group and connection to core

Water-soluble anthraquinones (AQs) hold great promise serving as redox-active species in aqueous organic redox flow batteries. Systematic investigations into how the properties of redox molecules depend on the water-solubilizing groups and the way in which they are bound to the redox core are, however, still lacking. We introduce water-solubilizing groups linked to anthraquinone by C=C bonds via Heck cross-coupling reactions and convert C=C bonds to CC bonds through hydrogenation. The anthraquinone and the ending groups are connected via branched or straight chains with either unsaturated or saturated bonds. We investigate the influence of water-solubilizing chains and ionic ending groups on redox potentials of molecules and identify three important trends. (1): The electron-withdrawing ending groups can affect redox potentials of AQs with two unsaturated hydrocarbons on the chains through π-conjugation. (2): For chains with two saturated or unsaturated straight hydrocarbons, water-solubilizing ending groups increase redox potentials of the AQs in the order of PO32 <CO2<SO3. (3): AQs with saturated and unbranched chains at high pH possess desirably low redox potentials, high solubilities, and high stability. Disproportionation leads to the formation of anthrone, which can be regenerated to anthraquinone. Tautomerization results in the saturation of alkene chains, stabilizing the structure. We utilize these observations to identify a potentially low-cost and long-lifetime negolyte that demonstrates a temporal fade rate as low as 0.0128%/day when paired with a potassium ferrocyanide posolyte