Recombinant hirudin suppresses angiogenesis of diffuse large B-cell lymphoma through regulation of the PAR-1-VEGF.

Hirudin is one of the specific inhibitors of thrombin, which has been confirmed to have strong bioactivities, including inhibiting tumors. However, the function and mechanism of hirudin and protease-activated receptor 1 (PAR-1) in diffuse large B-cell lymphoma (DLBCL) have not been clear. Detecting the expression PAR-1 in DLBCL tissues and cells by RT-qPCR and IHC. Transfected sh-NC, sh-PAR-1, or pcDNA3.1-PAR-1 in DLBCL cells or processed DLBCL cells through added thrombin, Vorapaxar, Recombinant hirudin (RH), or Na2S2O4 and co-culture with EA.hy926. And built DLBCL mice observed tumor growth. Detecting the expression of related genes by RT-qPCR, Western blot, IHC, and immunofluorescence, measured the cellular hypoxia with Hypoxyprobe-1 Kit, and estimated the cell inflammatory factors, proliferation, migration, invasion, and apoptosis by ELISA, CCK-8, flow cytometry, wound-healing and Transwell. Co-immunoprecipitation and pull-down measurement were used to verify the relationship. PAR-1 was highly expressed in DLBCL tissues and cells, especially in SUDHL2. Na2S2O4 induced SUDHL2 hypoxia, and PAR-1 did not influence thrombin-activated hypoxia. PAR-1 could promote SUDHL2 proliferation, migration, and invasion, and it was unrelated to cellular hypoxia. PAR-1 promoted proliferation, migration, and angiogenesis of EA.hy926 or SUDHL2 through up-regulation vascular endothelial growth factor (VEGF). RH inhibited tumor growth, cell proliferation, and migration, promoted apoptosis of DLBCL, and inhibited angiogenesis by down-regulating PAR-1-VEGF. RH inhibits proliferation, migration, and angiogenesis of DLBCL cells by down-regulating PAR-1-VEGF.

Pyoderma gangrenosum complicated with hematological malignancies: Two case reports.

INTRODUCTION: Pyoderma gangrenosum (PG) is a rare noninfectious neutrophilic skin disease. The diagnosis of PG is mainly based on clinical manifestations. Therefore, the clinical features of PG are important for confirming the diagnosis of this disease. Herein, the clinical data of 2 young males with PG complicated with hematological malignancies were reported, and the literature were reviewed. CASE PRESENTATION: The first case was a 22-year-old male who was admitted due to a systemic rash, headache, and fever. Physical examination showed black scabs on the skins of the extremities, trunk, scalp, and face. Biopsy of the skin lesion showed epidermal edema, spongy formation, neutrophil infiltration, acute and chronic inflammatory cell infiltration in the dermis, showing purulent inflammation with epidermal erosion. The bone marrow biopsy showed obviously active proliferation of nucleated cells, granulocytes at various stages, abnormal morphological neutrophils, and occasionally observed young red blood cells. The diagnosis of PG and chronic myelomonocytic leukemia (CMML-0) was made. The second case was a 28-year-old male who presented a swollen, painful right calf following injury and then developed ulcers on skin and soft tissues. Bone marrow biopsy showed obviously active nucleated cell proliferation, suggesting a myeloid tumor. He was also diagnosed with PG and hematological malignancies. They both received hormone and antiinfection therapy. After treatment, their body temperature, infection, and skin lesions were improved. However, both of them were readmitted and had a poor prognosis. CONCLUSIONS: PG may be associated with hematological malignancies. For patients with typical skin lesions and obvious abnormal blood routines, it is necessary to investigate the possibility of PG with hematological malignancies.

Reconstitution of Natural Killer cells after allogeneic hematopoietic stem cell transplantation is facilitated by Huiyang-Guben decoction through activating the Smad7/Stat3 signal pathway.

Natural Killer (NK) cell is the first batch of re-constructed cell populations after allogeneic hematopoietic stem cell transplantation (allo-HSCT), and its delayed reconstitution inevitably causes poor outcome. The traditional Chinese medicine Huiyang-Guben decoction (HYGB) has been clinically used in patients undergoing allo-HSCT, but its effect on NK cell reconstruction is still unclear. 40 patients with allo-HSCT therapy were randomly divided into the control group and the HYGB group, and were given oral administration of normal saline or HYGB for 4 weeks before allo-HSCT, respectively. NK cells were cultured and treated with transforming growth factor ß (TGF-ß) and HYGB in vitro, and cell viability, cell apoptosis, and the function of NK cells were evaluated. Functional verification experiments were performed by knocking down signal transduction molecule 7 (Smad7) in NK cells before TGF-ß and HYGB treatment. Clinical data suggested that HYGB intervention decreased the incidence of acute graft-versus-host disease after allo-HSCT, and increased the proportion of NK cell population. Meanwhile, HYGB improved cell viability, restrained apoptotic cell death, and enhanced cell killing activity of NK cells in patients with allo-HSCT. Notably, we found that HYGB significantly increased the expression level of Smad7 and the phosphorylation level of signal transducer and activator of transcription 3 (Stat3) in NK cells from patients with allo-HSCT. Moreover, HYGB alleviated TGF-ß-induced NK cell impairment and re-activated the Smad7/Stat3 signaling in vitro, while silencing Smad7 reversed the protective effect of HYGB on TGF-ß-treated NK cells. HYGB promotes NK cell reconstruction and improves NK cell function after allo-HSCT through activating the Smad7/Stat3 signaling pathway.

Anti-cancer potential of selenium-chitosan-polyethylene glycol-carvacrol nanocomposites in multiple myeloma U266 cells.

Multiple myeloma (MM) is an incurable cancer that is characterized by malignant plasma cell proliferation. Approximately 10% of all blood cancers are MM, and there is no standard curative therapy. In this work, we intended to synthesize, characterize, and assess the anticancer effects of selenium/chitosan/polyethylene glycol-carvacrol nanocomposites (SCP-Car-NCs) on MM U266 cells in vitro. Various characterization techniques were used to characterize the synthesized SCP-Car-NCs. Several in vitro free radical scavenging experiments were conducted to test the ability of synthesized SCP-Car-NCs to scavenge the different free radicals. The cytotoxicity of SCP-Car-NCs was assessed on Vero and U266 cells using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. By using various fluorescence staining techniques, the amount of reactive oxygen species (ROS) generation, MMP, and apoptosis were measured. Using commercial test kits, the levels of oxidative stress and apoptotic biomarkers in control and treated U266 cells were assessed. The highest peak in the UV spectral analysis was found to be at 271 nm, demonstrating the development of SCP-Car-NCs. Fourier transform infrared analysis showed that the synthesized SCP-Car-NCs contained a variety of stretching and bonding. The X-ray diffraction study confirmed the crystallinity of SCP-Car-NCs. The dynamic light scattering analysis showed that the SCP-Car-NCs had an average size of 171 nm. The different free radicals, such as the 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, and peroxyl radicals, were significantly scavenged by the SCP-Car-NCs. According to the MTT assay results, the SCP-Car-NCs decreased the viability of U266 cells while having no impact on the proliferation of Vero cells. The SCP-Car-NCs significantly boosted ROS production, decreased the MMP level, and promoted apoptosis, as evidenced by the fluorescence staining experiments. In U266 cells treated with SCP-Car-NCs, the level of thiobarbituric acid reactive substances increased while superoxide dismutases and glutathione levels were reduced. In the SCP-Car-NCs treated U266 cells, it was found that the Bax, caspase-3, and -9 activities had increased while the Bcl-2 level had decreased. In conclusion, our findings show that SCP-Car-NCs treatment reduced the viability and increased apoptosis in the U266 cells, providing a new insight on SCP-Car-NCs' potential for usage in the future to treat MM.

Case Report: An unclassified T cell lymphoma subtype with co-expression of TCR αß and γ chains revealed by single cell sequencing.

Background: T cell lymphomas (TCL) are a group of heterogeneous diseases with over 40 subtypes. In this study, we identified a novel TCL subtype which was featured by a unique T cell receptor (TCR) presentation, α, ß and γ chains were co-existing in a single malignant T cell. Case presentation: A 45-year-old male patient was diagnosed T cell lymphoma after 2-month of abdominal distension and liver enlargement. Combining histology review, PET-CT scanning and immunophenotyes, the patient was not classified to any existing TCL subtypes. To better understand this unclassified TCL case, we performed single cell RNA sequencing paired with TCR sequencing on the patient's PBMC and bone marrow samples. To our surprise, we identified that the malignant T cells had a very rare TCR combination, by expressing two α chains, one ß chain and one γ chain simultaneously. We further studied the molecular pathogenesis and tumor cell heterogeneity of this rare TCL subtype. A set of potential therapeutic targets were identified from the transcriptome data, such as CCL5, KLRG1 and CD38. Conclusions: We identified the first TCL case co-expressing α, ß and γ chains and dissected its molecular pathogenesis, providing valuable information for precision medicine options for this novel TCL subtype.

VMF-SSD: A Novel V-Space Based Multi-Scale Feature Fusion SSD for Apple Leaf Disease Detection.

Apple leaf diseases seriously affect the quality of apples and may lead to yield losses, detecting apple leaf diseases accurately can prevent diseases from spreading and promote the healthy growth of the industry. However, recent studies cannot achieve accurate detection of leaf diseases with high accuracy because the lesions are of different sizes. So, this paper proposed a novel apple leaf disease detection method called VMF-SSD (V-space-based Multi-scale Feature-fusion SSD), which is designed to extract more reliable multi-scale feature representations for varied sizes of diseased spots and improve the final detection performance. The multi-scale feature extraction is established with multi-scale feature representation to further improve the disease detection performance, especially for small spots. After that, a V-space-based location branch is presented to enhance the texture feature information and help further identify disease spot location. Finally, attention mechanisms are utilized to automatically learn the importance of feature channels at different scales for distinguishing diseased spots of different sizes. Experimental results showed that the VMF-SSD method achieves 83.19% mAP and obtains the detection speed of 27.53 FPS on the test set, which indicates that the proposed VMF-SSD method can achieve competitive performance on apple leaf diseases detection task and satisfy the requirements of agricultural production applications.

Single cell profiling of γδ hepatosplenic T-cell lymphoma unravels tumor cell heterogeneity associated with disease progression.

PURPOSE: Hepatosplenic T-cell lymphoma (HSTCL), mostly derived from γδ T cells, is a rare but very aggressive lymphoma with poor outcomes. In this study, we generated the first single cell landscape for this rare disease and characterized the molecular pathogenesis underlying the disease progression. METHODS: We performed paired single cell RNA-seq and T cell receptor (TCR) sequencing on biopsies from a HSTCL patient pre- and post- chemotherapy treatments. Following by a series of bioinformatics analysis, we investigated the gene expression profile of γδ HSTCS as well as its tumor microenvironment (TME). RESULTS: We characterized the unique gene expressing signatures of malignant γδ T cells with a set of marker genes were newly identified in HSTCL (AREG, PLEKHA5, VCAM1 etc.). Although the malignant γδ T cells were expanded from a single TCR clonotype, they evolved into two transcriptionally distinct tumor subtypes during the disease progression. The Tumor_1 subtype was dominant in pre-treatment samples with highly aggressive phenotypes. While the Tumor_2 had relative mild cancer hallmark signatures but expressed genes associated with tumor survival signal and drug resistance (IL32, TOX2, AIF1, AKAP12, CD38 etc.), and eventually became the main tumor subtype post-treatment. We further dissected the tumor microenvironment and discovered the dynamically rewiring cell-cell interaction networks during the treatment. The tumor cells had reduced communications with the microenvironment post-treatment. CONCLUSIONS: Our study reveals heterogenous and dynamic tumor and microenvironment underlying pathogenesis of HSTCL and may contribute to identify novel targets for diagnosis and treatment of HSTCL in the future.

LAD-Net: A Novel Light Weight Model for Early Apple Leaf Pests and Diseases Classification.

Aphids, brown spots, mosaics, rusts, powdery mildew and Alternaria blotches are common types of early apple leaf pests and diseases that severely affect the yield and quality of apples. Recently, deep learning has been regarded as the best classification model for apple leaf pests and diseases. However, these models with large parameters have difficulty providing an accurate and fast diagnosis of apple leaf pests and diseases on mobile terminals. This paper proposes a novel and real-time early apple leaf disease recognition model. AD Convolution is firstly utilized to replace standard convolution to make smaller number of parameters and calculations. Meanwhile, a LAD-Inception is built to enhance the ability of extracting multiscale features of different sizes of disease spots. Finally, the LAD-Net model is built by the LR-CBAM and the LAD-Inception modules, replacing a full connection with global average pooling to further reduce parameters. The results show that the LAD-Net, with a size of only 1.25MB, can achieve a recognition performance of 98.58%. Additionally, it is only delayed by 15.2ms on HUAWEI P40 and by 100.1ms on Jetson Nano, illustrating that the LAD-Net can accurately recognize early apple leaf pests and diseases on mobile devices in real-time, providing portable technical support.

Identification of TNFRSF1A as a novel regulator of carfilzomib resistance in multiple myeloma.

Multiple myeloma (MM) is a hematological tumor with high mortality and recurrence rate. Carfilzomib is a new-generation proteasome inhibitor that is used as the first-line therapy for MM. However, the development of drug resistance is a pervasive obstacle to treating MM. Therefore, elucidating the drug resistance mechanisms is conducive to the formulation of novel therapeutic therapies. To elucidate the mechanisms of carfilzomib resistance, we retrieved the GSE78069 microarray dataset containing carfilzomib-resistant LP-1 MM cells and parental MM cells. Differential gene expression analyses revealed major alterations in the major histocompatibility complex (MHC) and cell adhesion molecules. The upregulation of the tumor necrosis factor (TNF) receptor superfamily member 1A (TNFRSF1A) gene was accompanied by the downregulation of MHC genes and cell adhesion molecules. Furthermore, to investigate the roles of these genes, we established a carfilzomib-resistant cell model and observed that carfilzomib resistance induced TNFRSF1A overexpression and TNFRSF1A silencing reversed carfilzomib resistance and reactivated the expression of cell adhesion molecules. Furthermore, TNFRSF1A silencing suppressed the tumorigenesis of MM cells in immunocompetent mice, indicating that TNFRSF1A may lead to carfilzomib resistance by dampening antitumor immunity. Furthermore, our results indicated that TNFRSF1A overexpression conferred carfilzomib resistance in MM cells and suppressed the expression of MHC genes and cell adhesion molecules. The suppression of MHC genes and cell adhesion molecules may impair the interaction between immune cells and cancer cells to impair antitumor immunity. Future studies are warranted to further investigate the signaling pathway underlying the regulatory role of TNFRSF1A in MM cells.

Agronomic evaluation of shade tolerance of 16 spring Camelina sativa (L.) Crantz genotypes under different artificial shade levels using a modified membership function.

Camelina [Camelina sativa (L.) Crantz] is currently gaining considerable attention as a potential oilseed feedstock for biofuel, oil and feed source, and bioproducts. Studies have shown the potential of using camelina in an intercropping system. However, there are no camelina genotypes evaluated or bred for shade tolerance. The objective of this study was to evaluate and determine the shade tolerance of sixteen spring camelina genotypes (growth stage: BBCH 103; the plants with 4-5 leaves) for intercropping systems. In this study, we simulated three different shade levels, including low (LST), medium (MST), and high shade treatments (HST; 15, 25, and 50% reduction of natural light intensity, respectively), and evaluated the photosynthetic and physiological parameters, seed production, and seed quality. The mean chlorophyll pigments, including the total chlorophyll and chlorophyll a and b across the 16 genotypes increased as shade level increased, while the chlorophyll fluorescence parameter Fv/Fm, chlorophyll a/b, leaf area, the number of silicles and branches plant-1 decreased as shade level increased. The first day of anthesis and days of flowering duration of camelina treated with shade were significantly delayed and shortened, respectively, as shade increased. The shortened lifecycle and altered flowering phenology decreased camelina seed yield. Additionally, the shade under MST and HST reduced the seed oil content and unsaturated fatty acids, but not saturated fatty acids. The dendrograms constructed using the comprehensive tolerance membership values revealed that CamK9, CamC4, and 'SO-40' were the relatively shade-tolerant genotypes among the 16 camelina genotypes. These camelina genotypes can grow under the shade level up to a 25% reduction in natural light intensity producing a similar seed yield and seed oil quality, indicating the potential to intercrop with maize or other small grain crops. The present study provided the baseline information on the response of camelina genotypes to different shade levels, which would help in selecting or breeding shade-tolerant genotypes.

Review for Rare-Earth-Modified Perovskite Materials and Optoelectronic Applications.

In recent years, rare-earth metals with triply oxidized state, lanthanide ions (Ln3+), have been demonstrated as dopants, which can efficiently improve the optical and electronic properties of metal halide perovskite materials. On the one hand, doping Ln3+ ions can convert near-infrared/ultraviolet light into visible light through the process of up-/down-conversion and then the absorption efficiency of solar spectrum by perovskite solar cells can be significantly increased, leading to high device power conversion efficiency. On the other hand, multi-color light emissions and white light emissions originated from perovskite nanocrystals can be realized via inserting Ln3+ ions into the perovskite crystal lattice, which functioned as quantum cutting. In addition, doping or co-doping Ln3+ ions in perovskite films or devices can effectively facilitate perovskite film growth, tailor the energy band alignment and passivate the defect states, resulting in improved charge carrier transport efficiency or reduced nonradiative recombination. Finally, Ln3+ ions have also been used in the fields of photodetectors and luminescent solar concentrators. These indicate the huge potential of rare-earth metals in improving the perovskite optoelectronic device performances.

Anticancer and Anti-inflammatory Effect of Diosmin against Dalton Ascitic Lymphoma Induced Leukemia.

Cancer is the world's biggest health problem and cancer-induced mortality happened all over the planet after the heart disease. The present study was to scrutinize the anti-leukemia effect of diosmin against Dalton Ascitic Lymphoma (DAL) induced leukemia in mice. DAL cell was used for induction the solid tumor. Body weight, life spans, tumor volume and mean survival time was estimated. Antioxidant, biochemical and pro-inflammatory cytokines were estimated. Diosmin showed the cell viability effect at dose dependent manner against the both cell lines. DAL induced solid tumor mice showed the decreased body weight, mean survival days, non viable cell count and increased the tumor volume, viable cell count and diosmin significantly (p < 0.001) reverse the effect of DAL. Diosmin significantly (p < 0.001) altered the hematological, differential leukocytes, antioxidant, biochemical, pro-inflammatory cytokines at dose dependently. Collectively, we can say that diosmin might alter the DAL induced abnormality via antioxidant and anti-inflammatory effects.

Daphnetin exerts an anticancer effect by attenuating the pro-inflammatory cytokines.

Leukemia is a malignant tissue-forming disease, which induces the overproduction of large numbers of immature blood cells entering the peripheral blood. It is well documented that inflammation plays a crucial role in the expansion of leukemia. Daphnetin has confirmed anti-inflammatory effects against various diseases. In this experimental study, we evaluated the anti-leukemia and anti-inflammatory effect of daphnetin against benzene-induced leukemia in rats and explored the underlying mechanism. Benzene was used for inducing leukemia in experimental rats. The rats were divided into different groups and the body weight, hematological parameters, bone marrow cells, cytokines, and inflammatory mediators were estimated. Reverse transcription polymerase chain reaction (RT-PCR) was used for estimating the messenger RNA (mRNA) expression of sphingosine-1-phosphate receptor-1. Daphnetin-treated rats showed upregulation of body weight compared to other groups. Moreover, Daphnetin reduced blasts in leukemic rats. It also altered hematological parameters such as red blood cells, white blood cells, lymphocytes, neutrophils, monocytes, eosinophils, monocytes, and basophils, respectively. Daphnetin-treated rats showed a reduction of pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1ß (IL-1ß), IL-2, IL-6, and inflammatory mediators including nuclear factor-κB. RT-PCR showed upregulated mRNA expression of sphingosine-1-phosphate receptor-1 of daphnetin-treated group rats compared to other groups. The current study showed that the anti-inflammatory effect of daphnetin against the benzene-induced leukemia via alteration of cytokines.

Thermal gradient induced tweezers for the manipulation of particles and cells.

Optical tweezers are a well-established tool for manipulating small objects. However, their integration with microfluidic devices often requires an objective lens. More importantly, trapping of non-transparent or optically sensitive targets is particularly challenging for optical tweezers. Here, for the first time, we present a photon-free trapping technique based on electro-thermally induced forces. We demonstrate that thermal-gradient-induced thermophoresis and thermal convection can lead to trapping of polystyrene spheres and live cells. While the subject of thermophoresis, particularly in the micro- and nano-scale, still remains to be fully explored, our experimental results have provided a reasonable explanation for the trapping effect. The so-called thermal tweezers, which can be readily fabricated by femtosecond laser writing, operate with low input power density and are highly versatile in terms of device configuration, thus rendering high potential for integration with microfluidic devices as well as lab-on-a-chip systems.

Complete mitochondrial genome of the Algerian honeybee, Apis mellifera intermissa (Hymenoptera: Apidae).

In this study, the complete mitochondrial genome sequence of Algerian honeybee, Apis mellifera intermissa, is analyzed for the first time. The results show that this genome is 16,336 bp in length, and contains 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 control region (D-loop). The overall base composition is A (43.2%), C (9.8%), G (5.6%), and T (41.4%), so the percentage of A and T (84.6%) is considerably higher than that of G and C. All the genes are encoded on H-strand, except for four subunit genes (ND1, ND4, ND4L, and ND5), two rRNA genes (12S and 16S rRNA), and eight tRNA genes. The complete mitochondrial genome sequence reported here would be useful for further phylogenetic analysis and conservation genetic studies in A. m. intermissa.

Construction of Anti-CD20 Single-Chain Antibody-CD28-CD137-TCRζ Recombinant Genetic Modified T Cells and its Treatment Effect on B Cell Lymphoma.

BACKGROUND: Immunotherapy has been explored as a new therapy for B cell lymphoma, which is a non-Hodgkin's lymphoma. Because CD20 is a B lymphocyte-specific marker, anti-CD20 single chain-tagged T lymphocytes have already begun to be experimentally used in B cell lymphoma treatment, but its use is still limited because of its unspecific targeting. T cells transfected with CD28 and CD137 can significantly improve the ability of cytokines secretion and anti-tumor effect, as well as extending T cell survival time and improving their proliferation ability. MATERIAL AND METHODS: Genes containing anti-CD20-CD28-CD137-TCRζ were constructed. After cloning and sequencing, the plasmid was constructed and packaged by lentivirus. It was transfected to the peripheral blood T lymphocyte after identification transfection to induce the fusion protein expression. The cells were incubated with Raji cells and the LDH test was performed to detect the cytotoxic effect of CAR-T cells; the tumor volume and survival rate were measured to observe its inhibitory effect on B cell lymphoma in nude mice. RESULTS: Gene with anti-CD20-CD28-CD137-TCRζ was successfully constructed and transfected to the T cell surface. LDH assay revealed that CAR-T cells can kill the Raji cells with a killing rate of 32.89±6.26%. It can significantly inhibit B cell lymphoma growth in nude mice. CONCLUSIONS: T lymphocytes transfected with anti-CD20-CD28-CD137-TCRζ fusion gene can kill B cell lymphoma, which could provide a new strategy for tumor treatment.

Experimental and theoretical investigation of macro-periodic and micro-random nanostructures with simultaneously spatial translational symmetry and long-range order breaking.

Photonic and plasmonic quasicrystals, comprising well-designed and regularly-arranged patterns but lacking spatial translational symmetry, show sharp diffraction patterns resulting from their long-range order in spatial domain. Here we demonstrate that plasmonic structure, which is macroscopically arranged with spatial periodicity and microscopically constructed by random metal nanostructures, can also exhibit the diffraction effect experimentally, despite both of the translational symmetry and long-range order are broken in spatial domain simultaneously. With strategically pre-formed metal nano-seeds, the tunable macroscopically periodic (macro-periodic) pattern composed from microscopically random (micro-random) nanoplate-based silver structures are fabricated chemically through photon driven growth using simple light source with low photon energy and low optical power density. The geometry of the micro-structure can be further modified through simple thermal annealing. While the random metal nanostructures suppress high-order Floquet spectra of the spatial distribution of refractive indices, the maintained low-order Floquet spectra after the ensemble averaging are responsible for the observed diffraction effect. A theoretical approach has also been established to describe and understand the macro-periodic and micro-random structures with different micro-geometries. The easy fabrication and comprehensive understanding of this metal structure will be beneficial for its application in plasmonics, photonics and optoelectronics.

Dressing plasmon resonance with particle-microcavity architecture for efficient nano-optical trapping and sensing.

We propose a particle-microcavity scheme for efficient optical trapping and sensing. When a resonant plasmonic nanoparticle (NP) is placed inside a microcavity with high Q-factor, sensitivity is enhanced in the far-field extinction while near-field around the NP is barely affected. Stable near-field and high sensitivity for optical trapping and ultrasensitive detection of nanosized targets are therefore realized simultaneously. Such a particle-microcavity system opens up a new hybrid nanophotonic device platform that combines the unique merits of conventional and plasmonic integrated photonics.

Metallic diffraction grating enhanced coupling in whispering gallery resonator.

For the first time, metallic diffraction grating is investigated to enable efficient coupling in the whispering gallery resonator (WGR). Six-fold field enhancement in the resonator is achieved with respect to their dielectric counter-parts. This higher coupling efficiency is attributed to the surface plasmon excitation which drives the whispering gallery mode along the grating. Fano resonances have been observed in optical reflection. With the metallic grating, single-port end-fire WGR configuration becomes possible - a scheme that has not been demonstrated in any other WGR coupling devices. Hence, it serves as a prototype for portable whispering gallery devices potentially useful in sensing, switching and nonlinear applications.

Plasmonic optical trap having very large active volume realized with nano-ring structure.

The feasibility of using gold nano-rings as plasmonic nano-optical tweezers is investigated. We found that at a resonant wavelength of λ=785 nm, the nano-ring produces a maximum trapping potential of ~32k(B)T on gold nanoparticles. The existence of multiple potential wells results in a very large active volume of ~10(6) nm(3) for trapping the target particles. The report nano-ring design provides an effective approach for manipulating nano-objects in very low concentration into the high-field region and is well suited for integration with microfluidics for lab-on-a-chip applications.