17 research outputs found
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Uptake, sequestration and tolerance of cadmium at cellular levels in the hyperaccumulator plant species Sedum alfredii.
Sedum alfredii is one of a few plant species known to hyperaccumulate cadmium (Cd). Uptake, localization, and tolerance of Cd at cellular levels in shoots were compared in hyperaccumulating (HE) and non-hyperaccumulating (NHE) ecotypes of Sedum alfredii. X-ray fluorescence images of Cd in stems and leaves showed only a slight Cd signal restricted within vascular bundles in the NHEs, while enhanced localization of Cd, with significant tissue- and age-dependent variations, was detected in HEs. In contrast to the vascular-enriched Cd in young stems, parenchyma cells in leaf mesophyll, stem pith and cortex tissues served as terminal storage sites for Cd sequestration in HEs. Kinetics of Cd transport into individual leaf protoplasts of the two ecotypes showed little difference in Cd accumulation. However, far more efficient storage of Cd in vacuoles was apparent in HEs. Subsequent analysis of cell viability and hydrogen peroxide levels suggested that HE protoplasts exhibited higher resistance to Cd than those of NHE protoplasts. These results suggest that efficient sequestration into vacuoles, as opposed to rapid transport into parenchyma cells, is a pivotal process in Cd accumulation and homeostasis in shoots of HE S. alfredii. This is in addition to its efficient root-to-shoot translocation of Cd
Quantum Image Processing and Its Application to Edge Detection: Theory and Experiment
Processing of digital images is continuously gaining in volume and relevance,
with concomitant demands on data storage, transmission and processing power.
Encoding the image information in quantum-mechanical systems instead of
classical ones and replacing classical with quantum information processing may
alleviate some of these challenges. By encoding and processing the image
information in quantum-mechanical systems, we here demonstrate the framework of
quantum image processing, where a pure quantum state encodes the image
information: we encode the pixel values in the probability amplitudes and the
pixel positions in the computational basis states. Our quantum image
representation reduces the required number of qubits compared to existing
implementations, and we present image processing algorithms that provide
exponential speed-up over their classical counterparts. For the commonly used
task of detecting the edge of an image, we propose and implement a quantum
algorithm that completes the task with only one single-qubit operation,
independent of the size of the image. This demonstrates the potential of
quantum image processing for highly efficient image and video processing in the
big data era.Comment: 13 pages, including 9 figures and 5 appendixe
Primitive neuroectodermal tumor of the prostate: Case report from China
Peripheral primitive neuroectodermal tumor (PNET) in the prostate is one of the most aggressive tumors and a rare, uncommon clinical disease entity with a very poor prognosis. We reported a case of PNET in the prostate of a 49-year-old man and diagnosed through a biopsy. The patient underwent chemotherapy followed by adjuvant external radiation therapy without cystoprostatectomy as recommended, and 2 years later there is no sign of recurrence or distant metastasis. The patient had a good recovery and satisfactory outcomes in the follow-up. The successful treatment of PNET in the prostate in our case without surgery will provide a good therapeutic regime for reference until now
A Review of On-Line Measurement Methods of Alkali Metal Emissions from Combustion by Passive Spontaneous Emission Spectroscopy
This article reviews the principles and applications of passive spontaneous emission spectroscopy (SES) for the quantitative determination of alkali metal concentrations emitted from combustion processes. The combustion of fuels that contain a high alkali metal content (Na and/or K) is challenging, as alkali metals reduce the slag formation temperature and induce fouling, causing combustion facilities to shutdown prematurely. The in situ on-line quantification of alkali metals is, thus, a critical measure to control combustion processes, preventing slagging and fouling from occurring. This review shows that several SES systems, developed by the Huazhong University of Science and Technology (HUST), are inexpensive, portable, and useful for measuring the alkali metal content, and have been applied for biomass combustion as well as coal and municipal solid waste combustion, from laboratory-scale settings (20 kW) to industrial facilities (300 MW). Compared with other research, the SES system from HUST has successfully quantified the emitted alkali metal concentrations during combustion. This review also highlights the challenges of the SES system and recommends further work to improve it for further applications
A Review of On-Line Measurement Methods of Alkali Metal Emissions from Combustion by Passive Spontaneous Emission Spectroscopy
This article reviews the principles and applications of passive spontaneous emission spectroscopy (SES) for the quantitative determination of alkali metal concentrations emitted from combustion processes. The combustion of fuels that contain a high alkali metal content (Na and/or K) is challenging, as alkali metals reduce the slag formation temperature and induce fouling, causing combustion facilities to shutdown prematurely. The in situ on-line quantification of alkali metals is, thus, a critical measure to control combustion processes, preventing slagging and fouling from occurring. This review shows that several SES systems, developed by the Huazhong University of Science and Technology (HUST), are inexpensive, portable, and useful for measuring the alkali metal content, and have been applied for biomass combustion as well as coal and municipal solid waste combustion, from laboratory-scale settings (20 kW) to industrial facilities (300 MW). Compared with other research, the SES system from HUST has successfully quantified the emitted alkali metal concentrations during combustion. This review also highlights the challenges of the SES system and recommends further work to improve it for further applications
Self-Supported Single Crystalline H<sub>2</sub>Ti<sub>8</sub>O<sub>17</sub> Nanoarrays as Integrated Three-Dimensional Anodes for Lithium-Ion Microbatteries
Well-ordered, one-dimensional H<sub>2</sub>Ti<sub>2</sub>O<sub>5</sub>, H<sub>2</sub>Ti<sub>8</sub>O<sub>17</sub>, TiO<sub>2</sub>–B, and anatase TiO<sub>2</sub>/TiO<sub>2</sub>–B nanowire arrays were innovatively designed and directly
grown on current collectors as high performance three dimensional
(3D) anodes for binder and carbon free lithium ion batteries (LIBs).
The prepared thin nanowires exhibited a single crystalline phase with
highly uniform morphologies, diameters ranging from 70–80 nm,
and lengths of around 15 μm. Specifically, reversible Li insertion
and extraction reactions around 1.6–1.8 V with initial intercalation
capacities of 326 and 271 mA h g<sup>–1</sup> at a cycling
rate of 0.1 C (where 1 C = 335 mA g<sup>–1</sup>) were observed
for H<sub>2</sub>Ti<sub>8</sub>O<sub>17</sub> and TiO<sub>2</sub>–B
nanowire arrays, respectively. Among the four compounds investigated,
the H<sub>2</sub>Ti<sub>8</sub>O<sub>17</sub> nanowire electrode demonstrated
optimal cycling stability, delivering a high specific discharge capacity
of 157.8 mA h g<sup>–1</sup> with a coulombic efficiency of
100%, even after the 500th cycle at a current rate of 1 C. Furthermore,
the H<sub>2</sub>Ti<sub>8</sub>O<sub>17</sub> nanowire electrode displayed
superior rate performance with rechargeable discharge capacities of
127.2, 111.4, 87.2, and 73.5 mA h g<sup>–1</sup> at 5 C, 10
C, 20 C, and 30 C, respectively. These results present the potential
opportunity for the development of high-performance LIBs based on
nanostructured Ti-based anode materials in terms of high stability
and high rate capability
Regional source apportionment of trace metals in fine particulate matter using an observation-constrained hybrid model
Abstract Trace metals in fine particulate matter (PM2.5) are of significant concern in environmental chemistry due to their toxicity and catalytic capability. An observation-constrained hybrid model is developed to resolve regional source contributions to trace metals and other primary species in PM2.5. In this method, source contributions to primary PM2.5 (PPM2.5) from the Community Multiscale Air Quality (CMAQ) Model at each monitoring location are improved to align better with the observation data by applying source-specific scaling factors estimated from a unique regression model. The adjusted PPM2.5 predictions and chemical speciation data are then used to generate observation-constrained source profiles of primary species. Finally, spatial distributions of their source contributions are produced by multiplying the improved CMAQ PPM2.5 contributions with the deduced source profiles. The model is applied to the Pearl River Delta (PRD) region, China using daily observation data collected at multiple stations in 2015 to resolve source contributions to 8 trace metals, elemental carbon, primary organic carbon, and 10 other primary species. Compared to three previous methods, the new model predicts 13 species with smaller model errors and 16 species with less model biases in 10-fold cross validation analysis. The source profiles determined in this study also show good agreement with those collected from the literature. The new model shows that during 2015 in the PRD region, Cu is mainly from the area sources (31%), industry sector (27%), and power generation (20%), with an annual average concentration as high as 50 ng m−3 in some districts. Meanwhile, major contributors to Mn are area sources (40%), emission from outside PRD (23%) and power generation (17%), leading to a mean level of around 10 ng m−3. Such information is essential in assessing the epidemiological impacts of trace metals as well as formulating effective control measures to protect public health
Multifunctional TiO<sub>2</sub>–C/MnO<sub>2</sub> Core–Double-Shell Nanowire Arrays as High-Performance 3D Electrodes for Lithium Ion Batteries
The unique TiO<sub>2</sub>–C/MnO<sub>2</sub> core–double-shell
nanowires are synthesized for the first time using as anode materials
for lithium ion batteries (LIBs). They combine both advantages from
TiO<sub>2</sub> such as excellent cycle stability and MnO<sub>2</sub> with high capacity (1230 mA h g<sup>–1</sup>). The additional
C interlayer intends to improve the electrical conductivity. The self-supported
nanowire arrays grown directly on current-collecting substrates greatly
simplify the fabrication processing of electrodes without applying
binder and conductive additives. Each nanowire is anchored to the
current collector, leading to fast charge transfer. The unique one-dimensional
core–double-shell nanowires exhibit enhanced electrochemical
performance with a higher discharge/charge capacity, superior rate
capability, and longer cycling lifetime
Erythrocyte membrane with CLIPPKF as biomimetic nanodecoy traps merozoites and attaches to infected red blood cells to prevent Plasmodium infection
Abstract Background Malaria remains a serious threat to global public health. With poor efficacies of vaccines and the emergence of drug resistance, novel strategies to control malaria are urgently needed. Results We developed erythrocyte membrane-camouflaged nanoparticles loaded with artemether based on the growth characteristics of Plasmodium. The nanoparticles could capture the merozoites to inhibit them from repeatedly infecting normal erythrocytes, owing to the interactions between merozoites and heparin-like molecules on the erythrocyte membrane. Modification with a phosphatidylserine-targeting peptide (CLIPPKF) improved the drug accumulation in infected red blood cells (iRBCs) from the externalized phosphatidylserine induced by Plasmodium infection. In Plasmodium berghei ANKA strain (pbANKA)-infected C57BL/6 mice, the nanoparticles significantly attenuated Plasmodium-induced inflammation, apoptosis, and anemia. We observed reduced weight variation and prolonged survival time in pbANKA-challenged mice, and the nanoparticles showed good biocompatibility and negligible cytotoxicity. Conclusion Erythrocyte membrane-camouflaged nanoparticles loaded with artemether were shown to provide safe and effective protection against Plasmodium infection. Graphical Abstrac