Profiling B cell immunodominance after SARS-CoV-2 infection reveals antibody evolution to non-neutralizing viral targets.

Dissecting the evolution of memory B cells (MBCs) against SARS-CoV-2 is critical for understanding antibody recall upon secondary exposure. Here, we used single-cell sequencing to profile SARS-CoV-2-reactive B cells in 38 COVID-19 patients. Using oligo-tagged antigen baits, we isolated B cells specific to the SARS-CoV-2 spike, nucleoprotein (NP), open reading frame 8 (ORF8), and endemic human coronavirus (HCoV) spike proteins. SARS-CoV-2 spike-specific cells were enriched in the memory compartment of acutely infected and convalescent patients several months post symptom onset. With severe acute infection, substantial populations of endemic HCoV-reactive antibody-secreting cells were identified and possessed highly mutated variable genes, signifying preexisting immunity. Finally, MBCs exhibited pronounced maturation to NP and ORF8 over time, especially in older patients. Monoclonal antibodies against these targets were non-neutralizing and non-protective in vivo. These findings reveal antibody adaptation to non-neutralizing intracellular antigens during infection, emphasizing the importance of vaccination for inducing neutralizing spike-specific MBCs.

The IFT81-IFT74 complex acts as an unconventional RabL2 GTPase-activating protein during intraflagellar transport.

Cilia are important cellular organelles for signaling and motility and are constructed via intraflagellar transport (IFT). RabL2 is a small GTPase that localizes to the basal body of cilia via an interaction with the centriolar protein CEP19 before downstream association with the IFT machinery, which is followed by initiation of IFT. We reconstituted and purified RabL2 with CEP19 or IFT proteins to show that a reconstituted pentameric IFT complex containing IFT81/74 enhances the GTP hydrolysis rate of RabL2. The binding site on IFT81/74 that promotes GTP hydrolysis in RabL2 was mapped to a 70-amino-acid-long coiled-coil region of IFT81/74. We present structural models for RabL2-containing IFT complexes that we validate in vitro and in cellulo and demonstrate that Chlamydomonas IFT81/74 enhances GTP hydrolysis of human RabL2, suggesting an ancient evolutionarily conserved activity. Our results provide an architectural understanding of how RabL2 is incorporated into the IFT complex and a molecular rationale for why RabL2 dissociates from anterograde IFT trains soon after departure from the ciliary base.

Biochemically validated structural model of the 15-subunit intraflagellar transport complex IFT-B.

Cilia are ubiquitous eukaryotic organelles impotant for cellular motility, signaling, and sensory reception. Cilium formation requires intraflagellar transport of structural and signaling components and involves 22 different proteins organized into intraflagellar transport (IFT) complexes IFT-A and IFT-B that are transported by molecular motors. The IFT-B complex constitutes the backbone of polymeric IFT trains carrying cargo between the cilium and the cell body. Currently, high-resolution structures are only available for smaller IFT-B subcomplexes leaving > 50% structurally uncharacterized. Here, we used Alphafold to structurally model the 15-subunit IFT-B complex. The model was validated using cross-linking/mass-spectrometry data on reconstituted IFT-B complexes, X-ray scattering in solution, diffraction from crystals as well as site-directed mutagenesis and protein-binding assays. The IFT-B structure reveals an elongated and highly flexible complex consistent with cryo-electron tomographic reconstructions of IFT trains. The IFT-B complex organizes into IFT-B1 and IFT-B2 parts with binding sites for ciliary cargo and the inactive IFT dynein motor, respectively. Interestingly, our results are consistent with two different binding sites for IFT81/74 on IFT88/70/52/46 suggesting the possibility of different structural architectures for the IFT-B1 complex. Our data present a structural framework to understand IFT-B complex assembly, function, and ciliopathy variants.

Optical and Antibacterial Properties of Chiral Arginine-Stabilized ZnO Nanoparticles.

The surface ligands of nanoparticles (NPs) play essential roles in material synthesis, properties, and applications. Chiral molecules have been the new hot topic in tuning the properties of inorganic NPs. Herein, l-arginine- and d-arginine-stabilized ZnO NPs were prepared, and the TEM, UV-vis, and PL spectra were investigated, which demonstrated that the l-arginine and d-arginine have different effects on the self-assembly and photoluminescence properties of ZnO NPs, showing an evident chiral effect. Furthermore, the results of the cell viability assays, plate counting method, and bacterial SEM images showed that ZnO@LA possessed lower biocompatibility and higher antibacterial efficiency than those of ZnO@DA, implying that the chiral molecules on the surface of nanomaterials may affect their bioproperties.

Biallelic DAW1 variants cause a motile ciliopathy characterized by laterality defects and subtle ciliary beating abnormalities.

PURPOSE: The clinical spectrum of motile ciliopathies includes laterality defects, hydrocephalus, and infertility as well as primary ciliary dyskinesia when impaired mucociliary clearance results in otosinopulmonary disease. Importantly, approximately 30% of patients with primary ciliary dyskinesia lack a genetic diagnosis. METHODS: Clinical, genomic, biochemical, and functional studies were performed alongside in vivo modeling of DAW1 variants. RESULTS: In this study, we identified biallelic DAW1 variants associated with laterality defects and respiratory symptoms compatible with motile cilia dysfunction. In early mouse embryos, we showed that Daw1 expression is limited to distal, motile ciliated cells of the node, consistent with a role in left-right patterning. daw1 mutant zebrafish exhibited reduced cilia motility and left-right patterning defects, including cardiac looping abnormalities. Importantly, these defects were rescued by wild-type, but not mutant daw1, gene expression. In addition, pathogenic DAW1 missense variants displayed reduced protein stability, whereas DAW1 loss-of-function was associated with distal type 2 outer dynein arm assembly defects involving axonemal respiratory cilia proteins, explaining the reduced cilia-induced fluid flow in particle tracking velocimetry experiments. CONCLUSION: Our data define biallelic DAW1 variants as a cause of human motile ciliopathy and determine that the disease mechanism involves motile cilia dysfunction, explaining the ciliary beating defects observed in affected individuals.

Design, synthesis and application of near-infrared fluorescence probe IR-780-Crizotinib in detection of ALK positive tumors.

At present, the early diagnosis and treatment of NSCLC has become an international research hotspot. However, how to realize the organic combination of highly sensitive and high-resolution tumor imaging diagnosis and effective treatment, and to provide effective information for the diagnosis and treatment of cancer is still a major problem in the integration of cancer diagnosis and treatment. In this study, based on the Crizotinib has a good targeted inhibitory effect on ALK positive tumor cells, the near-infrared targeted fluorescent dye IR-780 was covalently bound with the drug molecule Crizotinib, thus the near-infrared fluorescent probe IR-780-Crizotinib targeting ALK positive tumor cells was synthesized. The probe structure is confirmed by NMR and MS. The optical properties of the fluorescent probe and the imaging process in ALK positive tumor-bearing mice were analyzed using ultraviolet spectrophotometer, near-infrared fluorescence spectrometer, and near-infrared fluorescence imaging system. The results show that the probe had better photoactivity. In vivo imaging shows that the probe maintained the biological activity of Crizotinib, effectively targeting the tumor site involved with clear imaging, and ultimately excreted from the body. It was confirmed that the probe could be used for the tracking, positioning and targeted therapy of nude mice with ALK positive tumors in vivo, thus exploring a new approach for the clinical application of near-infrared fluorescent probe to detect ALK positive tumors in the future.

Non-targeted metabolomics reveal the impact of phenanthrene stress on root exudates of ten urban greening tree species.

Different root exudations can modify the bioavailability of persistent organic pollutants (POPs). Among these exudations, the low molecular weight organic acids play an imperative role in this process. The study was conducted to analyze the effect of phenanthrene (PHE) stress on root exudation variations and changes in its chemical composition in ten urban greening tree species, namely Loropetalum chinense, Gardenia ellis, Photinia fraseri, Ligustrum japonicum, Rhododendron simsii, Osmanthus fragrans, Gardenia jasminoides, Buxus sinica, Camellia sasanqua, and Euonymus japonicas. The experiment was carried out in three PHE concentration treatments (0 mg kg-1 (CK), 200 mg kg-1 (PHEL), 2000 mg kg-1 (PHEH)). The root exudates were collected and analyzed by GC-MS method. In total, 673 compounds were identified either with high or low abundance among all species and treatments. Compounds identified in CK, PHEL, and PHEH were 240, 180, and 256, respectively. The results illustrated that carbohydrates, phenols, and esters were the dominant compounds, accounted for more than 92%. Principal component analysis depicted that tree species grown in PHEH showed obvious alteration in compounds of root exudation, whereas little difference was noticed between PHEL and CK. Phenols (80%) were the most abundant, while nitriles contributed a small portion. Moreover, among all species, R. simsii released the maximum number of compounds, and L. japonicum released the least number of compounds accounting for 89 and 46, respectively. The results achieved here to illustrate that plant type, and PHE stress can significantly change the concentrations and species of root exudates. This study provides the scientific reference for understanding the phenanthrene responsive changes in root exudates and phytoremediation of polycyclic aromatic hydrocarbons (PAHs), as well as a screening of urban greening tree species.

Comparison of platelet-rich fibrin (PRF) produced using 3 commercially available centrifuges at both high (~ 700 g) and low (~ 200 g) relative centrifugation forces.

OBJECTIVES: Platelet-rich fibrin (PRF) has gained tremendous momentum in recent years as a natural autologous growth factor derived from blood capable of stimulating tissue regeneration. Owing to its widespread use, many companies have commercialized various centrifugation devices with various proposed protocols. The aim of the present study was to compare 3 different commercially available centrifuges at both high and low g-force protocols. MATERIALS AND METHODS: PRF was produced on three commercially available centrifuges including the IntraSpin Device (IntraLock), the Duo Quattro (Process for PRF), and Salvin (Salvin Dental). Two separate protocols were tested on each machine including the original leukocyte and platelet-rich fibrin (L-PRF) protocol (~ 700 RCF max (~ 400 RCF clot) for 12 min) as well as the advanced platelet-rich fibrin (A-PRF+) protocol (~ 200 g RCF max (~ 130 g RCF clot) for 8 min). Each of the tested groups was compared for cell numbers, growth factor release, scanning electron microscopy (SEM) for morphological differences, and clot size (both weight and length/width). RESULTS: The present study found that PRF clots produced utilizing the low-speed centrifugation speeds (~ 200 g for 8 min) produce clots that (1) contained a higher concentration of evenly distributed platelets, (2) secreted higher concentrations of growth factors over a 10 day period, and (3) were smaller in size. This was irrespective of the centrifugation device utilized and consistently observed on all 3 devices. The greatest impact was found between the protocols utilized (up to a 200%). Interestingly, it was further revealed that the centrifugation tubes used had a much greater impact on the final size outcome of PRF clots when compared to centrifugation devices. It was found that, in general, the Process for PRF tubes produced significantly greater-sized clots when compared to other commercially available tubes. The Salvin Dental tubes also produced significantly greater PRF clots when compared to the IntraLock tubes on each of the tested centrifugation devices. CONCLUSIONS: The present study demonstrated the reproducibility of a scientific concept (reduction in RCF produces PRF clots with more evenly distributed cells and growth factors) utilizing different devices. Furthermore, (and until now overlooked), it was revealed for the first time that the centrifugation tubes are central to the quality production of PRF. Future research investigating tube characteristics thus becomes critically important for the future optimization of PRF. CLINICAL RELEVANCE: This is the first study to reveal the marked impact of centrifugation tubes on the final production of PRF. Future study thus becomes markedly important to further optimize the quality of PRF-based matrices. It was further found that little variability existed between the centrifugation devices if optimized centrifugation protocols (lower centrifugation speeds) were utilized.

Analysis of disease organ as a novel phenotype towards disease genetics understanding.

Discerning the modular nature of human diseases through computational approaches calls for diverse data. The finding sites of diseases, like other disease phenotypes, possess rich information in understanding disease genetics. Yet, analysis of the rich knowledge of disease finding sites has not been comprehensively investigated. In this study, we built a large-scale disease organ network (DON) based on 76,561 disease-organ associations (for 37,615 diseases and 3492 organs) extracted from the United Medical Language System (UMLS) Metathesaurus. We investigated how phenotypic organ similarity among diseases in DON reflects disease gene sharing. We constructed a disease genetic network (DGN) using curated disease-gene associations and demonstrated that disease pairs with higher organ similarities not only are more likely to share genes, but also tend to share more genes. Based on community detection algorithm, we showed that phenotypic disease clusters on DON significantly correlated with genetic disease clusters on DGN. We compared DON with a state-of-art disease phenotype network, disease manifestation network (DMN), that we have recently constructed, and demonstrated that DON contains complementary knowledge for disease genetics understanding.

Purification, Characterization of Two Polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine and Their Anti-Inflammatory Effects on Mucus Secretion of Airway Epithelium.

Pinelliae Rhizoma Praeparatum cum Alumine (PRPCA) is an important traditional processed herbal medicine mainly used for treating phlegm in China for more than 2000 years. In our previous studies, extraction optimization, characterization, and bioactivities of total polysaccharides from PRPCA were investigated. In this study, further purification of these polysaccharides was performed. Two polysaccharides named neutral fraction of total polysaccharides-II (TPN-II) and acidic fraction of total polysaccharides-II (TPA-II) were obtained by gradient ion-exchange chromatography followed by gel-permeation chromatography. Results of scanning electron microscopy (SEM) analysis in the present study showed that TPN-II had a tight structure with a rough and uneven surface, while TPA-II had a relative homogeneous surface and a loose structure. Further studies indicated that TPN-II was a homosaccharide mainly composed by glucose with a molecular weight of 8.0 kDa. TPA-II was mainly composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and arabinose in a molar ratio of 2.1, 2.3, 1.7, 10.6, 2.6, 14.2, and 2.5, with a molecular weight of 1250 kDa. The nuclear magnetic resonance (NMR) results indicated that α and ß form glycoside bonds existed in TPN-II and TPA-II, and TPN-II was composed of α-glucopyranose. In addition, both purified polysaccharides have significant anti-inflammatory effects on mucus secretion of human airway epithelial NCI-H292 cells without cytotoxicity. Compared with TPN-II, TPA-II exhibited more significant anti-inflammatory effects on lipopolysaccharide (LPS)-induced airway inflammation by regulating levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) and inhibiting mucus secretion. The results suggest that polysaccharides from PRPCA could be explored as therapeutic agents in treating inflammation and over secretion of mucus in asthma.

Traditional Uses, Botany, Phytochemistry, Pharmacology, Pharmacokinetics and Toxicology of Xanthium strumarium L.: A Review.

Xanthium strumarium L. (Asteraceae) is a common and well-known traditional Chinese herbal medicine usually named Cang-Er-Zi, and has been used for thousands of years in China. The purpose of this paper is to summarize the progress of modern research, and provide a systematic review on the traditional usages, botany, phytochemistry, pharmacology, pharmacokinetics, and toxicology of the X. strumarium. Moreover, an in-depth discussion of some valuable issues and possible development for future research on this plant is also given. X. strumarium, as a traditional herbal medicine, has been extensively applied to treat many diseases, such as rhinitis, nasal sinusitis, headache, gastric ulcer, urticaria, rheumatism bacterial, fungal infections and arthritis. Up to now, more than 170 chemical constituents have been isolated and identified from X. strumarium, including sesquiterpenoids, phenylpropenoids, lignanoids, coumarins, steroids, glycosides, flavonoids, thiazides, anthraquinones, naphthoquinones and other compounds. Modern research shows that the extracts and compounds from X. strumarium possess wide-ranging pharmacological effects, including anti- allergic rhinitis (AR) effects, anti-tumor effects, anti-inflammatory and analgesic effects, insecticide and antiparasitic effects, antioxidant effects, antibacterial and antifungal effects, antidiabetic effects, antilipidemic effects and antiviral effects. However, further research should focus on investigating bioactive compounds and demonstrate the mechanism of its detoxification, and more reasonable quality control standards for X. strumarium should also be established.

MicroRNA-1-3p inhibits the proliferation and migration of oral squamous cell carcinoma cells by targeting DKK1.

We investigated the functional role and mechanism of miR-1-3p and DKK1 in oral squamous cell carcinoma (OSCC) cells. The level of miR-1-3p and DKK1 expression were detected in OSCC tissues and cells using reverse-transcription - quantitative PCR and Western blot. A dual luciferase reporter gene assay was applied to confirm the targeting relationship between miR-1-3p and DKK1. Functional assays, including MTT, Transwell, colony formation, and flow cytometry analysis were conducted to verify their effect on cell progressions. MTT, colony formation, and Transwell assays indicated that the proliferation, migration, and invasion of SCC-4 cells was impaired with high miR-1-3p expression but promoted with high DKK1 expression. The results from cell cycle analysis and annexin-V-PI assays for apoptosis suggested that miR-1-3p suppressed the transit of SCC-4 cells from G0/G1 to S and induced apoptosis. In summary, miR-1-3p suppressed the progression of OSCC by inhibiting DKK1 expression.

Zanthoxylum bungeanum Maxim. (Rutaceae): A Systematic Review of Its Traditional Uses, Botany, Phytochemistry, Pharmacology, Pharmacokinetics, and Toxicology.

Zanthoxylum bungeanum Maxim. (Rutaceae) is a popular food additive and traditional Chinese herbal medicine commonly named HuaJiao in China. This plant is widely distributed in Asian countries. The aim of this paper is to provide a systematic review on the traditional usages, botany, phytochemistry, pharmacology, pharmacokinetics, and toxicology of this plant. Furthermore, the possible development and perspectives for future research on this plant are also discussed. To date, over 140 compounds have been isolated and identified from Z. bungeanum, including alkaloids, terpenoids, flavonoids, and free fatty acids. The extracts and compounds have been shown to possess wide-ranging biological activity, such as anti-inflammatory and analgesic effects, antioxidant and anti-tumor effects, antibacterial and antifungal effects, as well as regulatory effects on the gastrointestinal system and nervous system, and other effects. As a traditional herbal medicine, Z. bungeanum has been widely used to treat many diseases, especially digestive disorders, toothache, stomach ache, and diarrhea. Many traditional usages of this plant have been validated by present investigations. However, further research elucidating the structure-function relationship among chemical compounds, understanding the mechanism of unique sensation, as well as exploring new clinical effects and establishing criteria for quality control for Z. bungeanum should be further studied.

Traditional Uses, Origins, Chemistry and Pharmacology of Bombyx batryticatus: A Review.

Bombyx batryticatus (B. batryticatus), a well-known traditional animal Chinese medicine, has been commonly used in China for thousands of years. The present paper reviewed advances in traditional uses, origin, chemical constituents, pharmacology and toxicity studies of B. batryticatus. The aim of the paper is to provide more comprehensive references for modern B. batryticatus study and application. In Traditional Chinese Medicine (TCM) culture, drugs containing B. batryticatus have been used to treat convulsions, headaches, skin prurigo, scrofula, tonsillitis and fever. Many studies indicate B. batryticatus contains various compounds, including protein and peptides, fatty acids, flavonoids, nucleosides, steroids, coumarin, polysaccharide and others. Numerous investigations also have shown that extracts and compounds from B. batryticatus exert a wide spectrum of pharmacological effects both in vivo and in vitro, including effects on the nervous system, anticoagulant effects, antitumor effects, antibacterial and antifungal effects, antioxidant effects, hypoglycemic effects, as well as other effects. However, further studies should be undertaken to investigate bioactive compounds (especially proteins and peptides), toxic constituents, using forms and the quality evaluation and control of B. batryticatus. Furthermore, it will be interesting to study the mechanism of biological activities and structure-function relationships of bioactive constituents in B. batryticatus.

Blockade of Androgen Markers Using a Novel Betasitosterol, Thioctic Acid and Carnitine-containing Compound in Prostate and Hair Follicle Cell-based Assays.

Androgenetic alopecia (AGA) affects approximately 70% of men and 40% of women in an age-dependent manner and is partially mediated by androgen hormones. Benign prostatic hyperplasia (BPH) similarly affects 50% of the male population, rising by 10% each decade. Finasteride inhibits 5-alpha reductase (5AR) and is used to treat both disorders, despite offering limited clinical benefits accompanied by significant adverse side effects. Building on our previous work demonstrating the efficacy of naturally derived 5AR inhibitors (such as stigmasterol and beta sitosterol), we hypothesize that targeting 5AR as well as inflammatory pathways may yield improved efficacy in AGA and BPH. Here we address these dual pathomechanisms by examining the potency of a novel composition using in vitro assays of representative cell lines for AGA (hair follicle dermal papilla cells) and BPH (LNCaP prostate cells), respectively. Exposure of cells to the novel test composition down-regulated mRNA expression profiles characteristic of both disease processes, which outperformed finasteride. Changes in mRNA expression were corroborated at the protein level as assessed by western blotting. These studies provide proof of concept that novel, naturally derived compositions simultaneously targeting 5AR and inflammatory mediators may represent a rational approach to treating AGA and BPH. Copyright © 2016 John Wiley & Sons, Ltd.

Transgenic Expression of Vitamin D Receptor in Gut Epithelial Cells Ameliorates Spontaneous Colitis Caused by Interleukin-10 Deficiency.

BACKGROUND: Vitamin D deficiency is common in patients with inflammatory bowel diseases. The vitamin D receptor (VDR) is a nuclear hormone receptor mediating the activity of vitamin D hormone. Our previous studies showed that intestinal epithelial VDR signaling inhibits colitis by protecting the mucosal epithelial barrier, and this activity is independent of non-epithelial immune VDR actions. Interleukin (IL)-10-deficient mouse is a chronic colitis model that develops colitis due to aberrant immune responses. Here we used IL-10 null (IL-10KO) model to assess the anti-colitic activity of epithelial VDR in the setting of an aberrant immune system. METHODS: We crossed IL-10KO mice with villin promoter-driven human (h) VDR transgenic (Tg) mice to generate IL-10KO mice that carry the hVDR transgene in intestinal epithelial cells (IL-10KO/Tg). IL-10KO and IL-10KO/Tg littermates were studied in parallel and followed for up to 25 weeks. RESULTS: By 25 weeks of age, accumulatively 79 % IL-10KO mice developed prolapse, whereas only 40 % IL-10KO/Tg mice did so (P < 0.001). Compared with IL-10KO mice, IL-10KO/Tg littermates showed markedly reduced mucosal inflammation in both small and large intestines, manifested by attenuation in immune cell infiltration and histological damage and a marked decrease in pro-inflammatory cytokine production. IL-10KO/Tg mice also showed reduced intestinal epithelial cell apoptosis as a result of diminished PUMA induction and caspase 3 activation. CONCLUSION: These observations demonstrate that targeting hVDR expression to intestinal epithelial cells is sufficient to attenuate spontaneous colitis caused by an ill-regulated immune system, confirming a critical role of the epithelial VDR signaling in blocking colitis development.

Expression and clinical significance of microRNA-1246 in human oral squamous cell carcinoma.

BACKGROUND: MicroRNAs (miRNAs) are small, non-coding RNAs that may function as oncogenes or tumor suppressors. Previous studies have shown that the expression level of miR-1246 was enhanced in multiple types of cancers. However, the expression of miR-1246 in human oral squamous cell carcinoma (OSCC) and its prognostic values remain unclear. MATERIAL AND METHODS: Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was used to analyze the expression of miR-1246 in 106 pairs of matched normal and tumor tissue samples. The chi-square test was used to examine the associations between miR-1246 expression and the clinicopathological characters. The survival curves were constructed by the Kaplan-Meier method. The influence of each clinical variable on survival was examined by the Cox multivariate regression analysis. RESULTS: The expression level of miR-1246 was significantly higher in tumor tissues and oral cancer cell lines than in normal controls (p<0.01). High expression of miR-1246 was found to significantly correlate with nodal status (p=0.015), TNM stage (p=0.005), and tumor grade (p=0.002). Enhanced miR-1246 correlated significantly with patient survival (p<0.01). In multivariate analysis, we found that miR-1246 expression was an independent prognostic factor of poor patient survival (p= 0.036; HR=2.82; 95% CI=1.07-7.43). CONCLUSIONS: High miR-1246 expression is associated with poor prognosis in OSCC and may serve as a novel prognostic marker in OSCC.

Comparative study of electroless copper film on different self-assembled monolayers modified ABS substrate.

Copper films were grown on (3-Mercaptopropyl)trimethoxysilane (MPTMS), (3-Aminopropyl)triethoxysilane (APTES) and 6-(3-(triethoxysilyl)propylamino)-1,3,5- triazine-2,4-dithiol monosodium (TES) self-assembled monolayers (SAMs) modified acrylonitrile-butadiene-styrene (ABS) substrate via electroless copper plating. The copper films were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Their individual deposition rate and contact angle were also investigated to compare the properties of SAMs and electroless copper films. The results indicated that the formation of copper nuclei on the TES-SAMs modified ABS substrate was faster than those on the MPTMS-SAMs and APTES-SAMs modified ABS substrate. SEM images revealed that the copper film on TES-SAM modified ABS substrate was smooth and uniform, and the density of copper nuclei was much higher. Compared with that of TES-SAMs modified resin, the coverage of copper nuclei on MPTMS and APTES modified ABS substrate was very limited and the copper particle size was too big. The adhesion property test demonstrated that all the SAMs enhanced the interfacial interaction between copper plating and ABS substrate. XRD analysis showed that the copper film deposited on SAM-modified ABS substrate had a structure with Cu(111) preferred orientation, and the copper film deposited on TES-SAMs modified ABS substrate is better than that deposited on MPTMS-SAMs or APTES-SAMs modified ABS resins in electromigrtion resistance.

[Effect of dihydroartemisinin combined irradiation on the apoptosis of human lung cancer GLC-82 cells and its mechanism study].

OBJECTIVE: To study the effect of dihydroartemisinin (DHA) combined irradiation on the apoptosis of human lung cancer GLC-82 cells and to study its mechanism. METHODS: The growth inhibition rate of GLC-82 cells acted by different concentrations DHA was detected using MTT assay at 24, 48, and 72 h, respectively. Clone forming test was used. With multi-target single-hit model, the radiosensitization effect was assessed by calculating sensitizing enhancement ratio (SER).The effect of DHA combined irradiation on the apoptosis of GLC-82 cell cycle distribution and apoptosis were measured by flow cytometry. The protein expression of p53, p21, Bcl-2, and Bax were detected by Western blot. RESULTS: Different concentrations DHA (4, 8, 16, 32, 64, and 128 µg/mL) had cytotoxicity on GLC-82 cells. The IC50 for 24, 48, and 72 h was 38.25,20.58, and 10.36 µg/mL, respectively, in obvious dose- and time-dependent manner. The growth inhibition rate was more significantly increased than that of the blank control group (P < 0.01, P<0.05). DHA had sensitization enhancement effect on GLC-82 cells, with SER of 1.4. DHA combined irradiation could obviously change the structure of GLC-82 cells cell cycle and induce apoptosis (with the apoptosis rate of 21.5%), which was significantly different from that of the blank control group (P < 0.05). Western blot showed the expression of p53 and p21 protein could be increased by DHA combined irradiation, and the expression of Bcl-2 protein down-regulated (P <0.01, P <0. 05). CONCLUSIONS: DHA had stronger cytotoxicity and radiosensitization on GLC-82 cells. Its mechanisms might lie in making the arrest of GLC-82 cells' growth at G0/G1 phase, decreasing the ratio of cells at S phase, restoring the function of p53, decreasing the expression of Bcl-2 protein, and inducing apoptosis in GLC-82 cells.

Log-Euclidean metric based covariance propagation on SPD manifold for continuous-discrete extended Kalman filtering.

For nonlinear systems with continuous dynamic and discrete measurements, a Log-Euclidean metric (LEM) based novel scheme is proposed to refine the covariance integration steps of continuous-discrete Extended Kalman filter (CDEKF). In CDEKF, the covariance differential equation is usually integrated with regular Euclidean matrix operations, which actually ignores the Riemannian structure of underlying space and poses a limit on the further improvement of estimation accuracy. To overcome this drawback, this work proposes to define the covariance variable on the manifold of symmetric positive definite (SPD) matrices and propagate it using the Log-Euclidean metric. To embed the LEM based novel propagation scheme, the manifold integration of the covariance for LEMCDEKF is proposed together with the details of efficient realization, which can integrate the covariance on SPD manifold and avoid the drawback of Euclidean scheme. Numerical simulations certify the new method's superior accuracy than conventional methods.