Experimental measurement of dynamic concentration of nanofluid in laminar flow

Nanofluid is thought to have a potential enhancement in heat transfer behaviour of fluid. The nanoparticle concentration in nanofluid is one of the most important factors that affect the nanofluid behaviour. The static concentration was applied in the researches under flowing condition. In this paper, Nuclear Magnetic Resonance (NMR) scanning was applied to study the dynamic concentration of nanofluid flow in pipe. The experiments were carried out with ferrofluid under different concentration and temperature. A new parameter T2* was introduced in the study. Experiments were carried out to obtain the T2* of nanofluid in the pipe. An empirical equation based on T2* and temperature was proposed to calculate the concentration of nanoparticles. Then, experiments were carried out with flowing ferrofluid in pipe. The dynamic concentration was calculated with the empirical equation. It has a highest concentration near the pipe wall. The concentration decreases from the wall to the pipe centre. Furthermore, the experiment result also gives out a chance to investigate the mechanism of nanoparticle movement in laminar flow with the concentration gradient along radius

2-Hydr­oxy-N′-[(E)-(3-hydr­oxy-2-naphth­yl)methyl­ene]benzohydrazide. Corrigendum

Corrigendum to Acta Cryst. (2009), E65, o262

Photothermal conversion and transfer in photothermal therapy: From macroscale to nanoscale

Photothermal therapy (PTT) is a promising alternative therapy for benign or even malignant tumors. To improve the selective heating of tumor cells, target-specific photothermal conversion agents are often included, especially nanoparticles. Meanwhile, some indirect methods by manipulating the radiation and heat delivery are also adopted. Therefore, to gain a clear understanding of the mechanism, and to improve the controllability of PTT, a few issues need to be clarified, including bioheat and radiation transfer, localized and collective heating of nanoparticles, etc. In this review, we provide an introduction to the typical bioheat transfer and radiation transfer models along with the dynamic thermophysical properties of biological tissue. On this basis, we reviewed the most recent advances in the temperature control methods in PTT from macroscale to nanoscale. Most importantly, a comprehensive introduction of the localized and collective heating effects of nanoparticle clusters is provided to give a clear insight into the mechanism for PPT from the microscale and nanoscale point of view

Nanoparticle hybrids as efficient theranostic nanoagents with enhanced near-infrared optical absorption and scattering

The design of high-efficiency theranostic nanoagents that can be utilized in tumor diagnosis and treatment has been investigated extensively in recent years. However, most of the existing nanoagents consist of uncommon materials and complex shell structures. Despite the efforts that have been made, the development of a simple and easily synthesized theranostic nanoplatform that can be applied in optical-based imaging-guided photothermal therapy still remains a challenge. In this paper, we investigated the optical characteristics of nanoparticle aggregates as potential theranostic nanoplatforms. The mechanism of spectrum shifting and the optical properties of contacting and non-contacting short nanochains were investigated. It was found that the near-field interaction of the gold nanosphere will not shift the localized surface plasmon resonance peak to the near-infrared region. However, when the nanospheres are connected to each other, a low energy resonance peak will be excited. On this basis, a simple hybrid theranostic nanoagent consisting of different nanosphere clusters was proposed. The nanohybrid exhibits high absorption and low scattering in the first near-infrared window (NIR-I) and high scattering and near-zero absorption in the second NIR (NIR-II). This characteristic can be beneficial to tumor diagnosis and treatment, i.e., NIR-I for photothermal therapy and NIR-II for optical imaging. Numerical results show that the performance of the proposed hybrid theranostic nanoagent remains excellent even with the existence of potential impuritie

ImMesh: An Immediate LiDAR Localization and Meshing Framework

In this paper, we propose a novel LiDAR(-inertial) odometry and mapping framework to achieve the goal of simultaneous localization and meshing in real-time. This proposed framework termed ImMesh comprises four tightly-coupled modules: receiver, localization, meshing, and broadcaster. The localization module utilizes the prepossessed sensor data from the receiver, estimates the sensor pose online by registering LiDAR scans to maps, and dynamically grows the map. Then, our meshing module takes the registered LiDAR scan for incrementally reconstructing the triangle mesh on the fly. Finally, the real-time odometry, map, and mesh are published via our broadcaster. The key contribution of this work is the meshing module, which represents a scene by an efficient hierarchical voxels structure, performs fast finding of voxels observed by new scans, and reconstructs triangle facets in each voxel in an incremental manner. This voxel-wise meshing operation is delicately designed for the purpose of efficiency; it first performs a dimension reduction by projecting 3D points to a 2D local plane contained in the voxel, and then executes the meshing operation with pull, commit and push steps for incremental reconstruction of triangle facets. To the best of our knowledge, this is the first work in literature that can reconstruct online the triangle mesh of large-scale scenes, just relying on a standard CPU without GPU acceleration. To share our findings and make contributions to the community, we make our code publicly available on our GitHub: https://github.com/hku-mars/ImMesh

Bacoside-A exerts protective effect against Parkinson’s disease-induced functional damage in mice via inhibition of apoptosis and oxidative response

Purpose: To determine the effect of bacoside-A on Parkinson's disease (PD) in a rat model, and elucidate its mechanism of action.Methods: A rat model of PD was established by administration of 5 µL of 6-hydroxydopamine in ascorbic acid (0.1 %). Measurement of serum levels of inflammatory factors was carried out using enzyme-linked immunosorbent assay (ELISA) kits. Western blotting was used to assay Bax, cytochrome c and Bcl-2 in rat hippocampus.Results: Bacoside-A treatment significantly reduced PD-induced high turning values in rats (p < 0.05). Treatment with bacoside-A reversed PD-mediated suppression of serum activities of CAT and glutathione peroxidase (GPx). In bacoside-A-treated PD rats, dose-dependent suppression of acetylcholinesterase (AChE) and inducible nitric oxide synthase (iNOS) activities were observed (p < 0.05). Bacoside-A-treated PD rats significantly (p < 0.018) reduced interleukin (IL)-1β and IL-6 levels. Treatment of PD rats with bacoside-A effectively reduced levels of tumor necrosis factor (TNF)-α, NF-κB p65, (COX)-2 and p53 protein, and also reversed up-regulations of Bax, cytochrome C, caspase-3 and caspase-9.Conclusion: Bacoside-A exhibits a protective effect against Parkinson disease-induced oxidative damage and neuronal degeneration in rats through downregulation of iNOS, AChE, inflammatory cytokines and pro-apoptotic proteins. Therefore, bacoside-A has potentials for use in the management of Parkinson disease. Keywords: Parkinson disease, Neuroprotective, Pro-apoptotic, Cytokines, Neurotoxicit

A first-in-human study of AMG 208, an oral MET inhibitor, in adult patients with advanced solid tumors.

BackgroundThis first-in-human study evaluated AMG 208, a small-molecule MET inhibitor, in patients with advanced solid tumors.MethodsThree to nine patients were enrolled into one of seven AMG 208 dose cohorts (25, 50, 100, 150, 200, 300, and 400 mg). Patients received AMG 208 orally on days 1 and days 4-28 once daily. The primary objectives were to evaluate the safety, tolerability, pharmacokinetics, and maximum tolerated dose (MTD) of AMG 208.ResultsFifty-four patients were enrolled. Six dose-limiting toxicities were observed: grade 3 increased aspartate aminotransferase (200 mg), grade 3 thrombocytopenia (200 mg), grade 4 acute myocardial infarction (300 mg), grade 3 prolonged QT (300 mg), and two cases of grade 3 hypertension (400 mg). The MTD was not reached. The most frequent grade ≥3 treatment-related adverse event was anemia (n = 3) followed by hypertension, prolonged QT, and thrombocytopenia (two patients each). AMG 208 exposure increased linearly with dose; mean plasma half-life estimates were 21.4-68.7 hours. One complete response (prostate cancer) and three partial responses (two in prostate cancer, one in kidney cancer) were observed.ConclusionsIn this study, AMG 208 had manageable toxicities and showed evidence of antitumor activity, particularly in prostate cancer

Passive control of temperature distribution in cancerous tissue during photothermal therapy using optical phase change nanomaterials

Thermal therapy is a very promising alternative treatment for benign tumor, in which the temperature control is a key issue to avoid unwanted thermal damage of healthy tissue. However, the active temperature control methods usually require the assistance of real-time and accurate temperature monitoring devices. Even though, the lag of temperature control is inevitable. Therefore, in the present work, a passive control method is proposed to improve the uniformity of temperature distribution inside tumorous tissue during laser induced thermal therapy (LITT). Optical phase change nanoparticles (O-PCNPs) are utilized to replace the commonly used noble metal nanoparticles to enhance and adjust the localized light absorption in tumor. In the early stage of LITT, the O-PCNPs is used to improve the specific absorption rate in the targeted region. However, after the local temperature reaches a certain level (phase transition temperature), the O-PCNPs convert from amorphous state to crystalline state. By carefully selecting the size, shape, and laser wavelength, the absorption cross section of O-PCNPs could drop dramatically after phase transition. Therefore, in the high temperature zone the local temperature increasing rate reduces due to the reduction of local heat generation rate. On the contrary, the temperature increasing rate rises in the low temperature zone since more energy is transferred to the deeper tissue. In the present work, results show that SiO2@VO2 nanoshells can be applied as thermal contrast agents to improve the temperature uniformity in tumor during LITT

Effect of adding copper oxide nanoparticles on the mass/heat transfer in falling film absorption

Absorber is an essential component that affects the efficiency of absorption refrigeration unit. Falling film absorption is one of the most widespread forms of the heat/mass transfer in absorption system. In this paper, based on the software COMSOL Multiphysics, the finite element method is used to establish the model of falling film absorption. The falling film absorption properties of nanofluids was studied by adding CuO nanoparticles. The results reveal that as the film flow rate increases, the average mass transfer flux rises first and then decreases. The average mass transfer flux increases with the rise of the concentration of solution at the inlet, the decrease of the temperature of solution at the inlet and the reduction of cooling water inlet temperature. After adding copper oxide nanoparticles to lithium bromide solution, the vapor absorption performance of lithium bromide solution can be significantly improved

Plasmonic Optical Tweezers for Particle Manipulation: Principles, Methods, and Applications

Inspired by the idea of combining conventional optical tweezers with plasmonic nanostructures, a technique named plasmonic optical tweezers (POT) has been widely explored from fundamental principles to applications. With the ability to break the diffraction barrier and enhance the localized electromagnetic field, POT techniques are especially effective for high spatial-resolution manipulation of nanoscale or even subnanoscale objects, from small bioparticles to atoms. In addition, POT can be easily integrated with other techniques such as lab-on-chip devices, which results in a very promising alternative technique for high-throughput single-bioparticle sensing or imaging. Despite its label-free, high-precision, and high-spatial-resolution nature, it also suffers from some limitations. One of the main obstacles is that the plasmonic nanostructures are located over the surfaces of a substrate, which makes the manipulation of bioparticles turn from a three-dimensional problem to a nearly two-dimensional problem. Meanwhile, the operation zone is limited to a predefined area. Therefore, the target objects must be delivered to the operation zone near the plasmonic structures. This review summarizes the state-of-the-art target delivery methods for the POT-based particle manipulating technique, along with its applications in single-bioparticle analysis/imaging, high-throughput bioparticle purifying, and single-atom manipulation. Future developmental perspectives of POT techniques are also discussed