Enhanced Brain Targeting Delivery of Salvianic Acid Using Borneol as a Promoter of Blood/Brain Transport and Regulator of P-gp.

BACKGROUND: Borneol can enhance the blood-brain barrier (BBB) permeability of some drugs and suppress the efflux transport of P-glycoprotein (P-gp), which will contribute to the brain delivery of salvianic acid A (SAA). OBJECTIVE: The study aimed to develop an approach to improve the brain targeting delivery of SAA with the aid of borneol. MATERIALS AND METHODS: "Borneol" was involved in SAA via esterified prodrug SAA borneol ester (SBE) and combined administration (SAA-borneol, SAA-B). Subsequently, the blood-brain transport of SAA through brain/blood distribution and P-gp regulation via expression and function assay were investigated in rats. RESULTS: The SBE and SAA-B-treated group received a three-fold brain concentration and longer t1/2 and retention period of active SAA than that of SAA alone (20.18/13.82 min vs. 6.48 min; 18.30/17.42 min vs. 11.46 min). In addition, blood to brain transport of active SAA in SBE was altered in comparison to that of SAA-B, ultimately resulting in a better drug targeting index (9.93 vs. 3.63). Further studies revealed that SBE-induced downregulation of P-gp expression occurred at the later stage of administration (60 min, P < 0.01), but SBE always showed a more powerful drug transport activity across BBB represented by Kp value of rhodamine 123 than SAA-B (30, 60 min, P < 0.05). CONCLUSION: The comparative results indicate that SBE exhibits prominent efficiency on SAA's targeting delivery through improved blood/brain metabolic properties and sustained inhibitory effect of "borneol" on P-gp efflux. Therefore, prodrug modification can be applied as a more effective approach for brain delivery of SAA.

Prediction of Nanoscale Water Meniscus Shape between Deliquescent KDP Crystal Optics and AFM Probe for Water-Dissolution Repairing.

KDP (KH2PO4) crystal optics are the key elements for megajoule laser facilities. Nanoscale surface defects would cause laser-induced damage when the optics are irradiated by a high-fluence laser (over 10 J/cm2). Dip-pen nanolithography (DPN) could be used to repair the nanoscale surface defects in the KDP optics by the water meniscus. The high humidity required for high-efficiency and soft KDP surfaces penetrated by the AFM probe brings challenges for accurately predicting the water meniscus shape to evaluate the effectiveness of the DPN water-dissolution repairing. The multisolutions of the Young-Laplace and Kelvin equations also lead to the wrong water meniscus shape. A theoretical model that takes the high humidity and the penetration of the AFM probes into account is developed. The parametrization Young-Laplace equations are adopted for the zero contact angle of the water films, and the AFM probe is treated as the combination of the cone and sphere for the water meniscus whose size is larger than the AFM tip radius under high humidity. The penetration of the AFM probe is modeled by Hertz theory. Both the water films (3.3 nm thickness at 99% relative humidity) and indentations (1.46 nm depth at 300 nN contact force) are non-negligible for the nanoscale water meniscus between the KDP surface and the AFM probe. Moreover, the rough-fine two-step method is proposed to lock the correct solution of the Young-Laplace and Kelvin equations. The effectiveness of the proposed model is verified by comparison with reported ESEM images and pull-off forces. In addition, the overgrowth dots on the KDP surface are compared with the water meniscus. The linear growth of the water meniscus would cause the linear growth of the overgrowth dot, which proves the proposed model could be used to guide the DPN water-dissolution repairing for the nanoscale surface defects in the KDP optics.

Unveiling sub-bandgap energy-level structures on machined optical surfaces based on weak photo-luminescence.

Sub-bandgap defect energy levels (SDELs) introduced by the point defects located in surface defect areas are considered the main factors in decreasing laser-induced damage thresholds (LIDTs). The suppression of SDELs could greatly increase LIDTs. However, no available method could detect SDELs, limiting the characterization and suppression of SDELs. Herein, a self-designed photo-luminescence detection system is developed to explore the weak transient-steady photo-luminescence properties of machined surfaces. Based on the excitation laser wavelength dependence of photo-luminescence properties, a sub-bandgap energy-level structure (SELS) containing SDELs is unveiled for the first time. Based on the developed mathematical model for predicting LIDTs, the feasibility of the detection method was verified. In summary, this work provides a novel approach to characterize SDELs on machined surfaces. This work could construct electronic structures and explore the transition behaviors of electrons, which is vital to laser-induced damage. Besides, this work could predict the LIDTs of the machined surfaces based on their PL properties, which provides convenience for evaluating the LIDTs of various optical elements in industrial production. Moreover, this work provides a convenient method for raising the LIDTs of various optical elements through monitoring and suppressing the SDELs on machined surfaces.

RNA-binding protein-regulated fibronectin is essential for EGFR-activated metastasis of head and neck squamous cell carcinoma.

There is a higher expression level of epidermal growth factor receptor (EGFR) in up to 90% of advanced head and neck squamous cell carcinoma (HNSCC) tissue than in normal surrounding tissues. However, the role of RNA-binding proteins (RBPs) in EGFR-associated metastasis of HNSCC remains unclear. In this study, we reveal that RBPs, specifically nucleolin (NCL) and heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2B1), correlated with the mesenchymal phenotype of HNSCC. The depletion of RBPs significantly attenuated EGF-induced HNSCC metastasis. Intriguingly, the EGF-induced EMT markers, such as fibronectin, were regulated by RBPs through the ERK and NF-κB pathway, followed by the enhancement of mRNA stability of fibronectin through the 5' untranslated region (5'-UTR) of the gene. The upregulation of fibronectin triggered the integrin signaling activation to enhance tumor cells' attachment to endothelial cells and increase endothelial permeability. In addition, the concurrence of EGFR and RBPs or EGFR and fibronectin was associated with overall survival and disease-free survival of HNSCC. The in vivo study showed that depletion of NCL, hnRNPA2B1, and fibronectin significantly inhibited EGF-promoted extravasation of tumor cells into lung tissues. The depletion of fibronectin or treatment with integrin inhibitors dramatically attenuated EGF-induced HNSCC metastatic nodules in the lung. Our data suggest that the RBPs/fibronectin axis is essential for EGF-induced tumor-endothelial cell interactions to enhance HNSCC cell metastasis.

Discovery of acylated isoquercitrin derivatives as potent anti-neuroinflammatory agents in vitro and in vivo.

Neuroinflammation is considered as an important pathological mechanism in neurodegenerative diseases. The natural isoquercitrin (IQ) was reported to have potential anti-neuroinflammatory activity. The acylation of glycoside in IQ enhanced its hydrophobicity, which was expected to enhance the protective effect against inflammation. In this study, three carboxylic acids with anti-neuroinflammatory effects including cinnamic acid, ibuprofen (IBU) and acetylsalicylic acid were introduced into the 6''-OH of IQ through the corresponding vinyl esters intermediates (8a-8c). Ultimately, the acylated IQ derivatives (Compound 9a-9c) were obtained with 35-42% yields using immobilized lipase Novozym 435 as catalyst. Subsequently, their anti-neuroinflammatory activities were evaluated in lipopolysaccharide (LPS)-induced BV2 cells. Compound 9b improved cell viability in the range of ≤50 µM and significantly decreased NO, PGE2 production and TNF-α, IL-1ß release and oxidative stress level with a concentration-dependent manner. Also, it could downregulate iNOS, COX-2, TNF-α and IL-1ß expression levels, approximately 40% reduction were achieved when 15µM compound 9b was employed. In addition, compound 9b resisted phosphorylation and degradation of IkBαs, suppressing the activation of NF-κB signaling pathway, exhibiting excellent neuroinflammatory inhibition. Moreover, the administration of compound 9b (30, 60 mg/kg) alleviated behavioral disorders and neuronal damages in LPS-induced neuroinflammatory mice. Meanwhile, the decreased TNF-α, IL-1ß release, expression and the inhibited glial cells activation were obtained in compound 9b-treated group, which was superior to that of IQ or IBU. Overall, these findings demonstrated that compound 9b, formed by the introduction of ibuprofen into IQ, can serve as a novel promising therapeutic agent for anti-neuroinflammation.

A comparative study of pectic polysaccharides from fresh and dried Dendrobium officinale based on their structural properties and hepatoprotection in alcoholic liver damaged mice.

In this study, two pectic polysaccharides from fresh and dried Dendrobium officinale, namely FDP and DDP, were obtained by sour-water extraction, ethanol precipitation and further purification with DEAE cellulose-52 and Sephadex G-100 column chromatography. FDP/DDP had eight similar glycosidic linkages including 1,4-linked-GlcAp, 1,4- and 1,3,4-linked-GalAp, 1,3,4- and T-linked-Glcp, 1,6- and T-linked-Galp, T-linked-Galp and T-linked-Xylp. Besides, FDP was marked by 1,6-, 1,2,6-linked-Manp and 1,2,4-, 1,2-linked-Rhap, and DDP consisted of unique 1,6-linked-GlcAp and 1,3,6-Manp. FDP with a molecular weight of 14.8 kDa generally showed stronger scavenging capacity against DPPH, ABTS and hydroxyl radicals than DDP (p < 0.05). Pretreatment with FDP/DDP alleviated the alcohol-induced liver injury in mice, and their serum aminotransferase and triglyceride levels were 10.3%-57.8% lower than those of the model group (MG). Meanwhile, the FDP/DDP-M and FDP/DDP-H groups (200 and 300 mg kg-1) displayed a remarkable increase in antioxidant enzyme activities and significant reduction in inflammatory cytokine levels in comparison with the MG. Further analysis revealed that FDP-treated mice generally exhibited lower transaminase levels and inflammatory cytokine expression as well as higher antioxidant enzyme activities than DDP-treated ones. The FDP-H group showed significant restoration, which was slightly less than or almost comparable to that of the bifendate-fed positive control. The above results indicate that D. officinale pectin can attenuate oxidative stress and inflammatory cytokine response, and ultimately ameliorate liver injury, and "fresh" pectin with specific structural characteristics is expected to be more promising as hepatoprotective food.

Evolution of the point defects involved under the action of mechanical forces on mechanically machined fused silica surfaces.

Point defects with different species are concentrated on most mechanically machined fused silica optical surfaces with surface defects, which would sharply decrease the laser damage resistance under intense laser irradiation. Various point defects have distinct roles in affecting the laser damage resistance. Especially, the proportions of various point defects have not been identified, posing the challenge in relating the intrinsic quantitative relationship among various point defects. To fully reveal the comprehensive effect of various point defects, it is necessary to systematically explore the origins, evolution laws and especially the quantitative relationship among point defects. Herein, seven types of point defects are determined. The unbonded electrons in point defects are found to tend to be ionized to induce laser damage and there is a definite quantitative relationship between the proportions of oxygen-deficient point defects and that of peroxide point defects. The conclusions are further verified based on the photoluminescence (PL) emission spectra and the properties (e.g., reaction rule and structural feature) of the point defects. On basis of the fitted Gaussian components and electronic-transition theory, the quantitative relationship between PL and the proportions of various point defects is constructed for the first time. E'-Center accounts for the highest proportion among them. This work is beneficial for fully revealing the comprehensive action mechanisms of various point defects and providing new insights in elucidating the defect-induced laser damage mechanisms of optical components under intense laser irradiation from the atomic scale.

Coixol ameliorates Toxoplasma gondii infection-induced lung injury by interfering with T. gondii HSP70/TLR4/NF-κB signaling pathway.

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that causes pulmonary toxoplasmosis, although its pathogenesis is incompletely understood. There is no cure for toxoplasmosis. Coixol, a plant polyphenol extracted from coix seeds, has a variety of biological activities. However, the effects of coixol on T. gondii infection have not been clarified. In this study, we infected a mouse macrophage cell line (RAW 264.7) and BALB/c mice with the T. gondii RH strain to establish infection models in vitro and in vivo, respectively, to explore protective effects and potential mechanisms of coixol on lung injury caused by T. gondii infection. Anti-T. gondii effects and underlying anti-inflammatory mechanisms of coixol were investigated by real-time quantitative PCR, molecular docking, localized surface plasmon resonance, co-immunoprecipitation, enzyme-linked immunosorbent assay, western blotting, and immunofluorescence microscopy. The results show that coixol inhibits T. gondii loads and T. gondii-derived heat shock protein 70 (T.g.HSP70) expression. Moreover, coixol reduced inflammatory cell recruitment and infiltration, and ameliorated pathological lung injury induced by T. gondii infection. Coixol can directly bind T.g.HSP70 or Toll-like receptor 4 (TLR4) to disrupt their interaction. Coixol prevented overexpression of inducible nitric oxide synthase, tumor necrosis factor-α, and high mobility group box 1 by inhibiting activation of the TLR4/nuclear factor (NF)-κB signaling pathway, consistent with effects of the TLR4 inhibitor CLI-095. These results indicate that coixol improves T. gondii infection-induced lung injury by interfering with T.g.HSP70-mediated TLR4/NF-κB signaling. Altogether, these findings suggest that coixol is a promising effective lead compound for the treatment of toxoplasmosis.

Effect of Pre-Existing Micro-Defects on Cutting Force and Machined Surface Quality Involved in the Ball-End Milling Repairing of Flawed KDP Crystal Surfaces.

When serving in extremely high-power laser conditions, KH2PO4 (KDP) surfaces are susceptible to incur laser damage points (also known as defects). Using micro-ball end milling cutters to repair and remove the pre-existing damage points on the flawed KDP crystal surface is the most effective method to control the growth of laser damage points on KDP crystal surfaces and prolong their service life. However, there are various forms of micro-defects (such as pits, scratches and brittle fractures) around the laser damage points on KDP crystal surfaces which possess remarkable effects on the micro-milling repair process and consequently deteriorate the repair quality. In this work, combined with nano-indentation experiments, elastic-plastic mechanics and fracture mechanics theory, a constitutive model considering the anisotropic property of KDP crystals and a three-dimensional (3D) finite element model (FEM) were established to simulate the cutting force and surface topography involved in the ball-end milling repairing of flawed KDP crystal surfaces. Besides, the micro-milling experiments were conducted to evaluate the change of cutting force and machined surface quality in the presence of micro-defects with various feed rates. The results show that micro-defects would induce the fluctuation of cutting force and a change of the undeformed cutting thickness (UCT) in the process of repairing the damage points on the crystal surface, which would lead to the brittle-ductile transition (BDT) and affect the machined surface quality. The machined surface quality was found to be deteriorated by the pre-existing micro-defects when the UCT was small (the UCT was less than 375 nm). On the contrary, brittle mode cutting in the local area can be transformed into ductile mode cutting, resulting in an improvement of repaired surface quality that is exhibited by the cutting force and microtopography. This work has great theoretical significance and engineering practical value for the promotion and application of micro-milling repairing technology in the practical manufacturing and operation of KDP optics applied to high-power laser systems.

An Overview of Laser Metal Deposition for Cladding: Defect Formation Mechanisms, Defect Suppression Methods and Performance Improvements of Laser-Cladded Layers.

With the development of society and the economy, there is an increasing demand for surface treatment techniques that can efficiently utilize metal materials to obtain good performances in the fields of mechanical engineering and the aerospace industry. The laser metal deposition (LMD) technique for cladding has become a research focus in recent years because of its lower dilution rate, small heat-effect zone and good metallurgical bonding between the coating and substrate. This paper reviews the simulation technology for the melt pool's grain growth mechanism, temperature and stress distribution that are directly related to defect formation in LMD technology. At the same time, the defect suppression method and the performance improvement method of the cladded layer in LMD technology are introduced. Finally, it is pointed out that the active selection of materials according to the required performance, combined with the controllable processing technology, to form the corresponding microstructure, and finally, to actively realize the expected function, is the future development direction of LMD technology.

Non-Singleton Type-3 Fuzzy Approach for Flowmeter Fault Detection: Experimental Study in a Gas Industry.

The main contribution of this paper is to develop a new flowmeter fault detection approach based on optimized non-singleton type-3 (NT3) fuzzy logic systems (FLSs). The introduced method is implemented on an experimental gas industry plant. The system is modeled by NT3FLSs, and the faults are detected by comparison of measured end estimated signals. In this scheme, the detecting performance depends on the estimation and modeling performance. The suggested NT3FLS is used because of the existence of a high level of measurement errors and uncertainties in this problem. The designed NT3FLS with uncertain footprint-of-uncertainty (FOU), fuzzy secondary memberships and adaptive non-singleton fuzzification results in a powerful tool for modeling signals immersed in noise and error. The level of non-singleton fuzzification and membership parameters are tuned by maximum correntropy (MC) unscented Kalman filter (KF), and the rule parameters are learned by correntropy KF (CKF) with fuzzy kernel size. The suggested learning algorithms can handle the non-Gaussian noises that are common in industrial applications. The various types of flowmeters are investigated, and the effect of common faults are examined. It is shown that the suggested approach can detect the various faults with good accuracy in comparison with conventional approaches.

Identification of resistance loci against new pathotypes of Plasmodiophora brassicae in Brassica napus based on genome-wide association mapping.

Genetic resistance is a successful strategy for management of clubroot (Plasmodiophora brassicae) of brassica crops, but resistance can break down quickly. Identification of novel sources of resistance is especially important when new pathotypes arise. In the current study, the reaction of 177 accessions of Brassica napus to four new, virulent pathotypes of P. brassicae was assessed. Each accession was genotyped using genotyping by sequencing to identify and map novel sources of clubroot resistance using mixed linear model (MLM) analysis. The majority of accessions were highly susceptible (70-100 DSI), but a few accessions exhibited strong resistance (0-20 DSI) to pathotypes 5X (21 accessions), 3A (8), 2B (7), and 3D (15), based on the Canadian Clubroot Differential system. In total, 301,753 SNPs were mapped to 19 chromosomes. Population structure analysis indicated that the 177 accessions belong to seven major populations. SNPs were associated with resistance to each pathotype using MLM. In total, 13 important SNP loci were identified, with 9 SNPs mapped to the A-genome and 4 to the C-genome. The SNPs were associated with resistance to pathotypes 5X (2 SNPs), 3A (4), 2B (5) and 3D (6). A Blast search of 1.6 Mb upstream and downstream from each SNP identified 13 disease-resistance genes or domains. The distance between a SNP locus and the nearest resistance gene ranged from 0.04 to 0.74 Mb. The resistant lines and SNP markers identified in this study can be used to breed for resistance to the most prevalent new pathotypes of P. brassicae in Canada.

Identification of Two Major QTLs in Brassica napus Lines With Introgressed Clubroot Resistance From Turnip Cultivar ECD01.

Plasmodiophora brassicae causes clubroot disease in brassica crops worldwide. Brassica rapa, a progenitor of Brassica napus (canola), possesses important sources for resistance to clubroot. A doubled haploid (DH) population consisting of 84 DH lines were developed from a Backcross2 (BC2) plant through an interspecific cross of B. rapa turnip cv. ECD01 (resistant, R) with canola line DH16516 (susceptible, S) and then backcrossed with DH16516 as the recurrent parent. The DH lines and their parental lines were tested for resistance to four major pathotypes (3A, 3D, 3H, and 5X) of P. brassicae identified from canola. The R:S segregation ratio for pathotype 3A was 1:3, and 3:1 for pathotypes 3D, 3H, and 5X. From genotyping by sequencing (GBS), a total of 355.3 M short reads were obtained from the 84 DH lines, ranging from 0.81 to 11.67 M sequences per line. The short reads were aligned into the A-genome of B. napus "Darmor-bzh" version 4.1 with a total of 260 non-redundant single-nucleotide polymorphism (SNP) sites. Two quantitative trait loci (QTLs), Rcr10 ECD01 and Rcr9 ECD01 , were detected for the pathotypes in chromosomes A03 and A08, respectively. Rcr10 ECD01 and Rcr9 ECD01 were responsible for resistance to 3A, 3D, and 3H, while only one QTL, Rcr9 ECD01 , was responsible for resistance to pathotype 5X. The logarithm of the odds (LOD) values, phenotypic variation explained (PVE), additive (Add) values, and confidence interval (CI) from the estimated QTL position varied with QTL, with a range of 5.2-12.2 for LOD, 16.2-43.3% for PVE, 14.3-25.4 for Add, and 1.5-12.0 cM for CI. The presence of the QTLs on the chromosomes was confirmed through the identification of the percentage of polymorphic variants using bulked-segregant analysis. There was one gene encoding a disease resistance protein and 24 genes encoding proteins with function related to plant defense response in the Rcr10 ECD01 target region. In the Rcr9 ECD01 region, two genes encoded disease resistance proteins and 10 genes encoded with defense-related function. The target regions for Rcr10 ECD01 and Rcr9 ECD01 in B. napus were homologous to the 11.0-16.0 Mb interval of chromosome A03 and the 12.0-14.5 Mb interval of A08 in B. rapa "Chiifu" reference genome, respectively.

Combined modulation of incident laser light by multiple surface scratches and their effects on the laser damage properties of KH2PO4 crystal.

Manufacturing-induced surface defects are deemed as a potential source, leading the laser-induced damage threshold (LIDT) of the actual KDP crystal optics to be much lower than the intrinsic one. However, the underlying mechanisms have not been fully recognized. We explore the combined modulation of incident laser light by multiple scratches and their effects on laser damage performance of KDP optics by modeling the light intensifications and performing a laser damage test. Under the combined modulation of multiple scratches, enhanced hot spots are generated due to the focusing effects of convex lens profiles surrounded by the neighboring scratches. The combined modulation actions are much stronger than that of a single scratch. The relative light intensities (IRs) caused by multiple scratches can reach up to two times, and the number of hot spots (IPs) are four times as large as those by a single scratch. The IRs exhibit a general, increasing tendency as the scratch density increases. But for the case of double total reflections of rear-surface scratches, the totally reflected lights are transmitted through neighboring scratches, resulting in decreasing tendency of IRs. The tested LIDTs and optical transmittances of multiple scratches present a gradual, decreasing tendency with the increase of scratch density, which agrees with the simulation results. Besides, the simulated light intensifications could well explain the locations of laser damage, which further verify the role of multiple scratches in lowering the laser damage resistance.

Arabidopsis UBC13 differentially regulates two programmed cell death pathways in responses to pathogen and low-temperature stress.

UBC13 is required for Lys63-linked polyubiquitination and innate immune responses in mammals, but its functions in plant immunity remain to be defined. Here we used genetic and pathological methods to evaluate roles of Arabidopsis UBC13 in response to pathogens and environmental stresses. Loss of UBC13 failed to activate the expression of numerous cold-responsive genes and resulted in hypersensitivity to low-temperature stress, indicating that UBC13 is involved in plant response to low-temperature stress. Furthermore, the ubc13 mutant displayed low-temperature-induced and salicylic acid-dependent lesion mimic phenotypes. Unlike typical lesion mimic mutants, ubc13 did not enhance disease resistance against virulent bacterial and fungal pathogens, but diminished hypersensitive response and compromised effector-triggered immunity against avirulent bacterial pathogens. UBC13 differently regulates two types of programmed cell death in response to low temperature and pathogen. The lesion mimic phenotype in the ubc13 mutant is partially dependent on SNC1. UBC13 interacts with an F-box protein CPR1 that regulates the homeostasis of SNC1. However, the SNC1 protein level was not altered in the ubc13 mutant, implying that UBC13 is not involved in CPR1-regulated SNC1 protein degradation. Taken together, our results revealed that UBC13 is a key regulator in plant response to low temperature and pathogens.

Effects of Propofol on Several Membrane Characteristics of Cervical Cancer Cell Lines.

BACKGROUND: Although significant advances have been made toward understanding the molecular mechanisms underlying the effect of propofol on tumor cell metastasis, less is known regarding how cell membrane and cytoskeletal ultrastructure are affected in this process. Here, we investigated the relationship between cell morphology and cell size, which are features mainly defined by the cytoskeleton. METHODS: To confirm the effects of propofol on the migratory ability of human cervical carcinoma cells, cell migration and invasion were examined through scratch wound healing and transwell membrane assays. Furthermore, HeLa cells cultivated with different concentrations of propofol were examined by confocal microscopy and atomic force microscopy (AFM), and the mean optical density and migration ability of these cells were also assessed. In addition, cell membrane morphology was inspected using AFM. RESULTS: The results of the wound healing and transwell membrane assays indicated that propofol decreases the migratory ability of cervical carcinoma cells compared to control cells. A comparative analysis of the test results revealed that short-term (3 h) exposure to propofol induced marked changes in cell membrane microstructure and in the cytoskeleton in a dose-dependent manner. These morphological changes in the cell membrane were accompanied by cytoskeleton (F-actin) derangement. The present findings demonstrate a close relationship between changes in cell membrane ultrastructure and cytoskeletal alterations (F-actin) in propofol-treated HeLa cells. AFM scanning analysis showed that cell membrane ultrastructure was significantly changed, including a clear reduction in membrane roughness. CONCLUSION: The influence of propofol on the HeLa cell cytoskeleton can be directly reflected by changes in cellular morphology, as assessed by AFM. Moreover, the use of AFM is a good method for investigating propofol-mediated changes within cytoskeletal ultrastructure.

Role of tool marks inside spherical mitigation pit fabricated by micro-milling on repairing quality of damaged KH2PO4 crystal.

Repairing initial slight damage site into stable structures by engineering techniques is the leading strategy to mitigate the damage growth on large-size components used in laser-driven fusion facilities. For KH2PO4 crystals, serving as frequency converter and optoelectronic switch-Pockels cell, micro-milling has been proven the most promising method to fabricate these stable structures. However, tool marks inside repairing pit would be unavoidably introduced due to the wearing of milling cutter in actual repairing process. Here we quantitatively investigate the effect of tool marks on repairing quality of damaged crystal components by simulating its induced light intensification and testing the laser-induced damage threshold. We found that due to the formation of focusing hot spots and interference ripples, the light intensity is strongly enhanced with the presence of tool marks, especially for those on rear surfaces. Besides, the negative effect of tool marks is mark density dependent and multiple tool marks would aggravate the light intensification. Laser damage tests verified the role of tool marks as weak points, reducing the repairing quality. This work offers new criterion to comprehensively evaluate the quality of repaired optical surfaces to alleviate the bottleneck issue of low laser damage threshold for optical components in laser-driven fusion facilities.

In PC3 prostate cancer cells ephrin receptors crosstalk to ß1-integrins to strengthen adhesion to collagen type I.

Eph receptor (Eph) and ephrin signaling can play central roles in prostate cancer and other cancer types. Exposed to ephrin-A1 PC3 prostate cancer cells alter adhesion to extracellular matrix (ECM) proteins. However, whether PC3 cells increase or reduce adhesion, and by which mechanisms they change adhesion to the ECM remains to be characterized. Here, we assay how ephrin-A1 stimulates PC3 cells to adhere to ECM proteins using single-cell force spectroscopy. We find that PC3 cells binding to immobilized ephrin-A1 but not to solubilized ephrin-A1 specifically strengthen adhesion to collagen I. This Eph-ephrin-A1 signaling, which we suppose is based on mechanotransduction, stimulates ß1-subunit containing integrin adhesion via the protein kinase Akt and the guanine nucleotide-exchange factor cytohesin. Inhibiting the small GTPases, Rap1 or Rac1, generally lowered adhesion of PC3 prostate cancer cells. Our finding suggests a mechanism by which PC3 prostate cancer cells exposed to ephrins crosstalk to ß1-integrins and preferably metastasize in bone, a collagen I rich tissue.

Increasing throughput of AFM-based single cell adhesion measurements through multisubstrate surfaces.

Mammalian cells regulate adhesion by expressing and regulating a diverse array of cell adhesion molecules on their cell surfaces. Since different cell types express distinct sets of cell adhesion molecules, substrate-specific adhesion is cell type- and condition-dependent. Single-cell force spectroscopy is used to quantify the contribution of cell adhesion molecules to adhesion of cells to specific substrates at both the cell and single molecule level. However, the low throughput of single-cell adhesion experiments greatly limits the number of substrates that can be examined. In order to overcome this limitation, segmented polydimethylsiloxane (PDMS) masks were developed, allowing the measurement of cell adhesion to multiple substrates. To verify the utility of the masks, the adhesion of four different cell lines, HeLa (Kyoto), prostate cancer (PC), mouse kidney fibroblast and MDCK, to three extracellular matrix proteins, fibronectin, collagen I and laminin 332, was examined. The adhesion of each cell line to different matrix proteins was found to be distinct; no two cell lines adhered equally to each of the proteins. The PDMS masks improved the throughput limitation of single-cell force spectroscopy and allowed for experiments that previously were not feasible. Since the masks are economical and versatile, they can aid in the improvement of various assays.

Influence of surface cracks on laser-induced damage resistance of brittle KH2PO4 crystal.

Single point diamond turning (SPDT) currently is the leading finishing method for achieving ultra-smooth surface on brittle KH(2)PO(4) crystal. In this work, the light intensification modulated by surface cracks introduced by SPDT cutting is numerically simulated using finite-difference time-domain algorithm. The results indicate that the light intensification caused by surface cracks is wavelength, crack geometry and position dependent. Under the irradiation of 355 nm laser, lateral cracks on front surfaces and conical cracks on both front and rear surfaces can produce light intensification as high as hundreds of times, which is sufficient to trigger avalanche ionization and finally lower the laser damage resistance of crystal components. Furthermore, we experimentally tested the laser-induced damage thresholds (LIDTs) on both crack-free and flawed crystal surfaces. The results imply that brittle fracture with a series of surface cracks is the dominant source of laser damage initiation in crystal components. Due to the negative effect of surface cracks, the LIDT on KDP crystal surface could be sharply reduced from 7.85J/cm(2) to 2.33J/cm(2) (355 nm, 6.4 ns). In addition, the experiment of laser-induced damage growth is performed and the damage growth behavior agrees well with the simulation results of light intensification caused by surface cracks with increasing crack depths.