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Cisplatin is one of the first line anti-cancer drugs prescribed for treatment of solid tumors; however, the chemotherapeutic drug resistance is still a major obstacle of cisplatin in treating cancers. Yu Ping Feng San (YPFS), a well-known ancient Chinese herbal combination formula consisting of Astragali Radix, Atractylodis Macrocephalae Rhizoma and Saposhnikoviae Radix, is prescribed as a herbal decoction to treat immune disorders in clinic. To understand the fast-onset action of YPFS as an anti-cancer drug to fight against the drug resistance of cisplatin, we provided detailed analyses of intracellular cisplatin accumulation, cell viability, and expressions and activities of ATP-binding cassette transporters and glutathione S-transferases (GSTs) in YPFS-treated lung cancer cell lines. In cultured A549 or its cisplatin-resistance A549/DDP cells, application of YPFS increased accumulation of intracellular cisplatin, resulting in lower cell viability. In parallel, the activities and expressions of ATP-binding cassette transporters and GSTs were down-regulated in the presence of YPFS. The expression of p65 subunit of NF-κB complex was reduced by treating the cultures with YPFS, leading to a high ratio of Bax/Bcl-2, i.e. increasing the rate of cell death. Prim-O-glucosylcimifugin, one of the abundant ingredients in YPFS, modulated the activity of GSTs, and then elevated cisplatin accumulation, resulting in increased cell apoptosis. The present result supports the notion of YPFS in reversing drug resistance of cisplatin in lung cancer cells by elevating of intracellular cisplatin, and the underlying mechanism may be down regulating the activities and expressions of ATP-binding cassette transporters and GSTs.

Introduction Our recent study found that selective ablation of the distal part of the ligament of Marshall (LOMLSPV ) could suppress ventricular arrhythmias (VAs) during acute myocardial infarction (AMI). This study was to investigate the possible underlying mechanisms. Methods Dogs were randomly divided into the sham-operated group (SO; n = 6), AMI group (AMI; n = 8) and the group undergoing LOMLSPV ablation ahead of AMI (LOMD+AMI; n = 8). Incidence of VAs, serum levels of malondialdehyde (MDA) and superoxide dismutase (SOD), expression of connexin (Cx43), Bcl-2, Bax, caspase-3, tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), and high mobility group box (HMGB)1 were compared. Anatomic and immunostaining examinations of LOM LSPV were performed. Results Compared with the AMI group, incidence of VAs was reduced in the LOMD+AMI group. Compared with the SO group, Cx43, SOD, and Bcl-2 were decreased, MDA, Bax, caspase-3, TNF-α, IL-6, and HMGB1 were increased in the MI group, and all the alterations were significantly restrained in the LOMD+AMI group. A visual nerve fiber communication between the left stellate ganglion (LSG) and LOM and abundant sympathetic nerve bundles distribution in LOMLSPV were revealed. Conclusions LOMLSPV ablation could suppress VAs during AMI. The possible mechanism may be associated with disconnection of the sympathetic conduit from LSG to the ventricles. Preservation of Cx43, inhibition of cardiac oxidative stress, apoptosis, and inflammation may be involved.

BACKGROUND Atrial ganglionated plexus (GP) ablation was proved to have therapeutic effects on vasovagal syncope. The study aimed to investigate whether selective ablation of only right anterior GP (ARGP) and right inferior GP (IRGP) was effective in a canine model of vasovagal syncope. METHODS Seventeen mongrel dogs were divided into control (N = 10) and ablation group (N = 7). Bilateral thoracotomy was performed at the fourth intercostal space and ARGP and IRGP were ablated in the ablation group. A bolus of veratridine (15 ug/kg) was injected into the left atrium to induce vasovagal reflex. Surface electrocardiogram and blood pressure (BP) were continuously monitored. Heart rate (HR) variability was calculated to represent cardiac autonomic tone. RESULTS Veratridine injection induced vasovagal reflex in all dogs. HR decreased from 149 ± 17 to 89 ± 33 beats/min (P

The sandwich-like 2H MoS2 and unilaminar graphitic nanocarbon hybrid was synthesized via graphitizing threonic acid intercalated MoS2 precursor obtained using hydrothermal process. An excellent electrocatalytic efficiency of hydrogen evolution reaction with a remarkably small overpotential of 195 mV and a Tafel slope of 47 mV/decade is easily accessible for our hybridized catalyst in 0.5 M H2SO4 aqueous solution, much superior to that of pure 2H MoS2 and threonic acid intercalating MoS2 nanomaterials. Moreover, the detailed electrochemical activity surface area and electrochemical impedance suggest that the face-to-face stacking of unilaminar 2H MoS2 and graphitic nanocarbon at an alternating sequence accelerates the mass transport and electron transfer and, thus, enhances the efficiency for electrocatalytic water splitting. This work paves a neoteric and straightforward pathway for the fabrication of superlattice MoS2 and unilaminar graphitic nanocarbon hybrid, further improving the electrocatalytic effi...

Individuals predisposed to vasovagal syncope may have different autonomic nervous system control mechanisms from those without predisposition to vasovagal events. To test this hypothesis, we investigated different sympathetic responses in a canine model of vasovagal syncope. Left thoracotomy was performed on 20 mongrel dogs. The heart was exposed and a bolus of veratridine (15 μg/kg), a neurotoxin which prevents the inactivation of sodium ion channels, was injected into the left atrium to induce a Bezold–Jarisch reflex-mediated vasovagal event, characterized by bradycardia, decreased inotropism, and hypotension. Electrocardiogram and blood pressure were continuously monitored. Neural activity was recorded from the left stellate ganglion. Plasma norepinephrine and acetylcholine levels were measured 30 s before and 30 s after veratridine injection. Veratridine resulted in rapid decreases in heart rate and blood pressure in all dogs, accompanied by increases in both norepinephrine and acetylcholine. Two types of neural activity (high-amplitude spike discharge activity and low-amplitude burst discharge activity) were recorded from the left stellate ganglion. Veratridine induced high-frequency spike discharge activity in some dogs (Group A), whereas spike discharge activity was scarce and relatively unresponsive to veratridine in the remaining dogs (Group B). Dogs in Group A had higher plasma norepinephrine levels (111.63 ± 15.1 vs. 48.11 ± 33.81 ng/l, p = 0.002) and less intense drops in heart rate (− 37 ± 24 vs. − 84 ± 28 bpm, p = 0.001) and blood pressure (systolic blood pressure, − 18 ± 15 vs. − 37 ± 13 mmHg, p = 0.009; diastolic blood pressure, − 26 ± 13 vs. − 45 ± 13 mmHg, p = 0.005) compared to dogs in Group B. Similarly, heart rate post-veratridine was higher (102 ± 23 vs. 69 ± 22 bpm, p = 0.004), the veratridine-induced longest RR interval was shorter (0.7 [0.5–0.8] vs. 1.2 [1.1–3.5] s, p

TiO 2 -supported Pt catalysts were prepared for the study of CO oxidation kinetics at reaction conditions of pressures (1–100 Torr) and temperatures (300–500 K). We find two distinct temperature ranges with different reaction kinetics distinguished by an abrupt slope change at around 380 K in the Arrhenius plot only with the excess O 2 , not with the stoichiometric O 2 /CO ratio. We propose that Pt oxides are formed during the catalytic reactions with increasing temperatures under the oxidizing condition and the origin of the slope change is due to the changes in the reaction pathways of CO oxidation due to the Pt oxide formation.

In this paper, sensitive and specific detections on dimethyl methylphosphonate (DMMP), a representative simulant of sarin and organophosphorus pesticides, are demonstrated by a piezoresistive cantilever-based aptasensor in neutral electrolytic solution. By improving the design and fabrication processes of the cantilever-based sensor, a Hooge factor of 4.8 × 10−6 and a surface stress sensitivity of 1.47 × 10−3 (N/m)−1 have been obtained, and the output fluctuation has been minimized to 1 μV at a 3 V bias voltage. For selective and specific molecular capturing, the sensing cantilevers was functionalized by 78-mer 5′-biotinylated aptamers in a biotin-streptavidin system. The aptasensor was experimentally demonstrated to have a linear behavior in detecting DMMP within the concentrations of 50 nM–1.0 μM. Attributed to the low electrical noise and high sensitivity of the piezoresistive cantilever, a limit of detection of 50 nM for DMMP was well obtained in phosphate buffered saline at neutral pH value. Besides, the aptasensors were also exposed to apple juice with DMMP added, whose detecting results indicate that the existence of biomacromolecular polysaccharides and the regional desorption of mercapto self-assembled layer from the gold film on the sensing cantilevers could result in a decrease of the detecting sensitivity slightly. The proposed cantilevers are promising for low cost, trace level and on-site biological/chemical detections.

In this paper, we demonstrate an ultra-broadband terahertz (THz) bi-metasurfaces absorber composed of two stacking metasurfaces backed by a metallic ground plane. The bottom metasurface consists of four multiplexed cross resonators with different geometries on a thin parylene layer, achieving a bandwidth of 3.80 THz with the absorption higher than 50% at high frequency. Meanwhile, the top metasurface, including two multiplexed cross resonators with different sizes on a relatively thicker parylene layer, provides a low frequency absorption band with an additional Salisbury screen absorption peak that connects the two absorption bands of the two metasurfaces, therefore enabling an ultra-broadband absorption. The experimental absorption spectrum of the bi-metasurfaces shows a bandwidth of 4.46 THz while the absorption exceeding 50% and a full width at half maxima (FWHM) of 97.7%. The ultra-broadband absorber will be a promising candidate for THz broadband detection.

Hydration–dehydration cycles can frequently cause stress to seeds, but can also be used to improve germination. However, the molecular basis of the stress caused is poorly understood. Herein, we examine the effects of hydration–dehydration cycles on seed viability and profile the membrane glycerolipid molecular species. We find that seed viability was not affected during the first two cycles, but significantly decreased as further cycles were applied, until all viability was lost. The abundances of seven glycerolipid classes increased and decreased through hydration and dehydration, respectively, but the phosphatidic acid and diacylglycerol abundances changed in the opposite sense, while total glycerolipid contents remained constant. This suggests that during hydration–dehydration cycles, turnover of glycerolipid metabolite pools take place, while no significant lipid synthesis or degradation is involved. As further hydration–dehydration cycles occurred, lipid unsaturation increased, plastidic lipids decreased, and phosphatidylserine acyl chains lengthened. The latter two could be lethal for seeds. Our findings reveal a novel model of membrane lipid changes, and provide new insights into the responses of seeds to hydration–dehydration cycles.

This paper presents the design, fabrication, and performance of a $256 \times 256$ multiband infrared (IR) focal plane array (FPA) using microbimaterial cantilever as the sensitive pixel. Different from traditional uncooled IR FPA that works only at long wavelength IR, the working bandwidth of the presented FPA is extended to full band IR, covering the three IR atmospheric windows of 1– $2.5~\mu $ m, 3– $5~\mu $ m and 8–14 $\mu $ m simultaneously. The multiband performance is attributed to the elaborately designed multiband absorber consisting of a stacked layer of silicon nitride, chromium nanofilm, and gold mirror. The absorbing mechanism of the stacked layer is discussed in detail and testified by experimental results. Images of short-wavelength, middle-wavelength, and long-wavelength IR were captured successfully with the single FPA. The measured sensitivity and noise equivalent temperature difference of the FPA are $0.18~\mu $ m/K and 194.7 mK, respectively. [2014-0090]

Imbibitional chilling injury during germination causes agricultural losses, but this can be overcome by osmopriming. It remains unknown how membranes reorganize during germination. Herein, we comparatively profiled changes of membrane lipids during imbibition under normal and chilling temperatures in chilling-tolerant and -sensitive soybean seeds. We found three patterns of dynamic lipid remodelling during the three phases of germination. Pattern 1 involved a gradual increase in plastidic lipids during phases I and II, with an abrupt increase during phase III. This abrupt increase was associated with initiation of photosynthesis. Pattern 3 involved phosphatidic acid (PA) first decreasing, then increasing, and finally decreasing to a low level. Patterns 1 and 3 were interrupted in chilling-sensitive seeds under low temperature, which lead a block in plastid biogenesis and accumulation of harmful PA, respectively. However, they were rescued and returned to their status under normal temperature after polyethylene glycol osmopriming. We specifically inhibited phospholipase D (PLD)-mediated PA formation in chilling-sensitive seeds of soybean, cucumber, and pea, and found their germination under low temperature was significantly improved. These results indicate that membranes undergo specific and functional reorganization of lipid composition during germination and demonstrate that PLD-mediated PA causes imibibitional chilling injury.

This work introduces a flexible piezoresistive microcantilever by using polyimide (PI) and silicon oxide (SiO 2 ) as the insulation layers of titanium (Ti) strain resistors. The microcantilever is elaborately devised including the strain and piezoresistive characteristics of Ti and the film formation and patterned process of the PI. The fabricated PI/Ti/SiO 2 microcantilever is steady and flexible with less than 3 μV@3V output voltage fluctuation in PBS buffer environment and a spring constant of 21.28 nN/μm. An aptasensor is developed through functionalizing the microcantilevers, which is able to detect ricin of 10 ng/mL concentration with good specificity. All the experiment results show that the PI/Ti/SiO 2 microcantilever-based aptasensor enables label free and high sensitivity chemical/biological molecules detection and analysis.

In this work, we report two multifocal terahertz (THz) lenses (MTLs) based on reflective metasurfaces with focusing efficiencies of 57.3% and 46.3% at a frequency of 3.11 THz, respectively. The reflective metasurfaces were constructed by patterning the polarization-insensitive cross resonator array atop a continuous gold ground plane spaced by a layer of parylene film, which provides a complete 2π phase coverage. The elaborated phase profiles of the two MTLs were arranged based on the Fresnel-Kirchhoff diffraction theory. The two MTLs were theoretically and experimentally verified to converge continuous THz waves into two and four beam spots at their focal planes, respectively. Meanwhile, the MTLs were also experimentally demonstrated with multiple imaging abilities.

Dendritic cells (DCs) are potent antigen‑presenting cells that play pivotal roles in the initiation of primary immune responses. Lycium barbarum polysaccharides (LBPs) are known to have a variety of immunomodulatory functions. However, the cellular and molecular mechanisms underlying their therapeutic effects are poorly understood. In this study, we report that LBPs induce phenotypic and functional maturation of DCs. LBPs upregulated DC expression of I‑A/I‑E and CD11c, enhanced DC allostimulatory activity and induced IL‑12p40 production. Furthermore, the activity of LBPs on DCs was significantly reduced by treating the cells with anti‑TLR2 or anti‑TLR4 antibody prior to LBPs, indicating that both are possible receptors of LBPs. Maturation of DCs by LBPs was able to directly activate the nuclear transcription factor NF‑κB p65. The results revealed that LBP stimulation induces the phenotypic and functional maturation of DCs via TLR2- and/or TLR4-mediated NF‑κB signaling pathways.

High sensitivity of seeds to water loss is a widespread phenomenon in the world's plant species. The molecular basis of this trait is poorly understood but thought to be associated with critical changes in membrane function. We profiled membrane lipids of seeds in eight species with varying levels of desiccation tolerance and found a close association between reducing seed viability and increasing phosphatidic acid (PA). We applied hydration-dehydration cycles to Arabidopsis seeds, which are normally desiccation tolerant, to mimic the onset of desiccation sensitivity with progression towards germination and examined the role of phospholipase D (PLD) in desiccation stress-induced production of PA. We found that PLDα1 became more abundant and migrated from the cytosol to the membrane during desiccation, whereas PLDδ did not change, and that all desiccation-induced PA was derived from PLDα1 hydrolysis. When PLDα1 was suppressed, the germination level after each hydration-dehydration cycle improved significantly. We further demonstrated that PLDα1-mediated PA formation modulates desiccation sensitivity as applying its inhibitor improved seed desiccation tolerance and its suppression in protoplasts enhanced survival under dehydration. The insights provided by comparative lipidomics enable us to propose a new membrane-based model for seed desiccation stress and survival.

Supermacroporous cryogel with embedded nano-size adsorbent particles is a new media suggested for separation and purification of biomolecules. In order to reveal the protein adsorption characteristics in this novel cryogel, several polyacrylamide-based cryogel beds with embedded Fe 3 O 4 nanoparticles were prepared by radical cryo-copolymerization of acrylamide, N , N ′-methylene-bis-acrylamide, allyl glycidyl ether and surfactant-stabilized Fe 3 O 4 nanoparticles under freezing variation conditions in glass columns of inner diameters 16 and 26 mm. Bovine serum albumin (BSA) was used as model protein to study the cryogel adsorption behaviors in the cryogels. Experimental measurements of the isothermal and kinetics adsorption of BSA were carried out and the protein adsorption capacities were determined. Breakthrough curves of BSA in NaAc–HAc buffer at different liquid flow rates were obtained to reveal the protein adsorption behaviors. Effect of liquid velocity, as well as the pore-structures and liquid dispersion on the protein breakthrough performance were investigated and analyzed.

This paper reports ultrasensitive detections of DNA and protein by multi-silicon-nanowire field-effect-transistor (SiNW-FET) biosensors. Single-SiNW-FET, double-SiNW-FET and quad-SiNW-FET have been designed on a single chip and fabricated by a simple top-down fabrication process. Compared with single-SiNW-FET, the multi-SiNW-FET biosensor shows a higher ability of decreasing the noise by averaging the source-drain currents. Both Norovirus DNA and IgG have been detected with the sensors at concentrations as low as 1 fM and 10 fM respectively. The sensor also shown high specificity in 1bp mismatch DNA disturbance.

The present case-control study explored the interaction between marine-derived n-3 long chain polyunsaturated fatty acids (n-3 LC PUFAs) and uric acid (UA) on glucose metabolism and risk of type 2 diabetes mellitus (T2DM). Two hundred and eleven healthy subjects in control group and 268 T2DM subjects in case group were included. Plasma phospholipid (PL) fatty acids and biochemical parameters were detected by standard methods. Plasma PL C22:6n-3 was significantly lower in case group than in control group, and was negatively correlated with fasting glucose (r = −0.177, p &lt, 0.001). Higher plasma PL C22:6n-3 was associated with lower risk of T2DM, and the OR was 0.32 (95% confidence interval (CI), 0.12 to 0.80, p = 0.016) for per unit increase of C22:6n-3. UA was significantly lower in case group than in control group. UA was positively correlated with fasting glucose in healthy subjects, but this correlation became negative in T2DM subjects. A significant interaction was observed between C22:6n-3 and UA on fasting glucose (p for interaction = 0.005): the lowering effect of C22:6n-3 was only significant in subjects with a lower level of UA. In conclusion, C22:6n-3 interacts with UA to modulate glucose metabolism.

Continuous supermacroporous monolithic cryogel is a novel sponge-like chromatographic adsorbent for bioseparation in downstream process and it is always prepared under a constant freezing-temperature condition. In this work, polyacrylamide-based supermacroporous monolithic cryogel beds in different inner diameter glass columns (I.D. 10, 16 and 26 mm) have been prepared by radical cryogenic copolymerization process under the condition of freezing-temperature variation. The matrix microstructure morphologies of these cryogels were analyzed by scanning electron microscopy (SEM) and the axial liquid dispersion characteristics in these cryogel beds were also analyzed by measuring the residence time distributions (RTDs). The formation of cryogel bed under the present situation has been considered as a coinstantaneous process of solvent crystal growth and polymeric monomer copolymerization. Effects of freezing-temperature variation route, cooling rate and redox initiator concentration on the cryogel microstructure and the liquid dispersion characteristics were investigated experimentally to reveal the cooperative mechanisms of these two processes on the formation of cryogel bed. The results showed that the cryogel pore-structures and the axial liquid dispersion coefficients in the cryogel beds depended strongly on the cooling condition, which controls the solvent crystallization process, and the redox initiator concentration, which influences the monomer polymerization.

Expression of ErbB4 receptor is correlated with the incidence of non-metastatic types of human cancers, whereas the overexpression of other ErbB receptor families (ErbB1/EGFR, ErbB2 and ErbB3) is correlated to the formation of metastatic tumors. However, the molecular mechanism underlying this phenomenon has been unclear. Earlier, we demonstrated that okadaic acid (OA), an inhibitor of a serine/threonine phosphatase PP2A, stimulated the growth hormone-induced ERK phosphorylation in the wild type Chinese hamster ovary (CHO) cells and the cells expressing ErbB1 receptor, but suppressed ERK activation in CHO cells that express ErbB4 receptor. PP2A had been understood as a negative regulator of the growth hormone-stimulated signal transduction pathways, however, this observation suggested that expression of ErbB4 receptor reversed the regulation of PP2A in the ErbB4 signalling pathway. In this study, we found that OA suppressed phosphorylation of Shc at Tyr317, therefore it down-regulated ERK phosphorylation in the ErbB4 expressing CHO cells. Accordingly, basal PP2A contributed to the phosphorylation of Shc Tyr317 in ErbB4 expressing CHO cells, nevertheless it had been reported that PP2A negatively regulates Shc tyrosine phosphorylation in the EGF- or IGF-I-induced signalling pathways. By testing OA for human cancer cell lines that express different types of ErbB receptors, we found that ErbB4 receptor expression was accompanied with positive regulation of PP2A for phosphorylation of Shc Tyr317 and its downstream ERK phosphorylation in MCF-7 and SK-OV-3 cell lines, but not in LNCaP and PC-3 cells. Thus, PP2A regulates the ERK activity in a cell-specific manner, and it is speculated that distinct regulation of PP2A in the ErbB4 receptor signalling pathway may cause a difference in progression of cancer phenotypes.

Ligand-activated and tyrosine-phosphorylated ErbB3 receptor binds to the SH2 domain of the p85 subunit of phosphatidylinositol 3-kinase and initiates intracellular signaling. Here, we studied the interactions between the N- (N-SH2) and C- (C-SH2) terminal SH2 domains of the p85 subunit of the phosphatidylinositol 3-kinase and eight ErbB3 receptor-derived phosphotyrosyl peptides (P-peptides) by using molecular dynamics, free energy, and surface plasmon resonance (SPR) analyses. In SPR analysis, these P-peptides showed no binding to the C-SH2 domain, but P-peptides containing a phospho-YXXM or a non-phospho-YXXM motif did bind to the N-SH2 domain. The N-SH2 domain has two phosphotyrosine binding sites in its N- (N1) and C- (N2) terminal regions. Interestingly, we found that P-peptides of pY1180 and pY1241 favored to bind to the N2 site, although all other P-peptides showed favorable binding to the N1 site. Remarkably, two phosphotyrosines, pY1178 and pY1243, which are just 63 amino acids apart from the pY1241 and pY1180, respectively, showed favorable binding to the N1 site. These findings indicate a possibility that the pair of phosphotyrosines, pY1178-pY1241 or pY1243-pY1180, will fold into an appropriate configuration for binding to the N1 and N2 sites simultaneously. Our model structures of the cytoplasmic C-terminal domain of ErbB3 receptor also strongly supported the speculation. The calculated binding free energies between the N-SH2 domain and P-peptides showed excellent qualitative agreement with SPR data with a correlation coefficient of 0.91. The total electrostatic solvation energy between the N-SH2 domain and P-peptide was the dominant factor for its binding affinity.

Using the Gemini surfactant [C12H25N+(CH3)(2-)N+(CH3)(2)-N+(CH3)(2)-C12H25](.)2Br(-) (abbreviated as C12-2-12) with the short spacer group (s = 2) as structure-directing agent and sodium silicate as precursor, high-quality ordered cubic mesoporous silica (space group Ia3d) was prepared through the S+I- route (S denotes surfactant, I precursor). The samples were characterized by small-angle X-ray diffraction, transmission electron microscopy, and N-2 adsorption-desorption techniques. Results showed that the pore structure of the resulting mesoporous silica belonged to the cubic structure (space group Ia3d). The high-quality cubic mesoporous structure was formed at 1:0.33 (molar ratio of sodium silicate to C12-2-12), 2:1 (ethyl acetate to sodium silicate), and at 30 degreesC. The formation conditions of MCM-48 with C12-2-12 were milder than those with the corresponding monovalent surfactants, such as alkyltrimethylammonium bromide. N-2 adsorption-desorption curves revealed type IV isotherms and H1 hysteresis loops; Brunauer-Emmet-Teller (BET) surface areas increased with the decrease of the molar ratio of sodium silicate to C12-2-12 and of ethyl acetate to sodium silicate as well as of the hydrothermal temperatures.

In this article, the sensitivity and the noise of piezoresistive cantilevers were systematically investigated with respect to the piezoresistor geometry, the piezoresistive materials, the doping dose, the annealing temperature, and the operating biased voltage. With the noise optimization results, dimension optimized array cantilevers were designed and fabricated by using single-crystal silicon, low-pressure chemical-vapor deposition (LPCVD) amorphous silicon and microcrystalline silicon as piezoresistive layers. Measurement results have shown that the smallest Hooge factor (alpha) was 3.2x10(-6), the biggest gauge factors was 95, and the minimum detectable deflection (MDD) at 6 V and 200 Hz-measurement bandwidth was 0.3 nm for a single-crystal silicon cantilever. Of the two LPCVD silicon piezoresistive cantilevers, amorphous silicon piezoresistors had relatively lower 1/f noise. The MDD for a LPCVD silicon cantilever at a 200 Hz-measurement bandwidth was 0.4 nm. For all kinds of piezoresistive cantilevers, the 1/f noises were decreased by 35%-50% and the gauge factors were decreased by 60-70% if the doping dose were increased by ten times. The annealing at 1050 degreesC for 30 min decreased 1/f noise by about 65% compared with the 950 degreesC for 10 min treatments. The cantilevers with a relatively higher-doping dose gave smaller MDD even though the gauge factors of them were decreased by nearly a factor of 1.8. The higher-biased voltages had no great improvements on the MDD due to the 1/f noise dominance.

Oligochitosan has been reported to possess anti-inflammatory properties; however, the mechanism of the antiinflammatory effects of oligochitosan remains unknown. The present study aimed to investigate the expression levels of inflammatory cytokines and the production of nitric oxide (NO), in the nuclear factor (NF)-κB pathway of lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophages. The results of the present study demonstrated that different concentrations of oligochitosan could significantly lower the levels of NO, tumor necrosis factor (TNF)-α and interleukin (IL)-1β, released from LPS-stimulated RAW264.7 cells. This was shown to be mediated through inhibiting the activation of the NF-κB pathway. These results demonstrate that oligochitosan may efficiently inhibit inflammation and has the potential to be an effective anti-inflammatory agent.

This paper presents the design, fabrication and performance of a 256×256 bimaterial cantilever focal plane array (FPA) which is able to work in the three infrared (IR) atmospheric windows of 1~2.5μm, 3~5μm and 8~14μm simultaneously. The FPA employs a silicon-framed structure by selectively etching away the substrate with Deep Reactive Ion Etching technique, and a stacked layer of chromium and SiNx serves as the multi-band absorber. The images of short wavelength, middle wavelength and long wavelength infrared were captured successfully with the same FPA by combining the Chromium nano-film with silicon nitride as the multi-band IR absorber. The measured sensitivity of the FPA is 0.18μm/K.

Resurrection plants usually grow in specific or extreme habitats and have the capacity to survive almost complete water loss. We characterized the physiological and biochemical responses of Paraisometrum mileense to extreme desiccation and found that it is a resurrection plant. We profiled the changes in lipid molecular species during dehydration and rehydration in P. mileense, and compared these with corresponding changes in the desiccation-sensitive plant Arabidopsis thaliana. One day of desiccation was lethal for A. thaliana but not for P. mileense. After desiccation and subsequent rewatering, A. thaliana showed dramatic lipid degradation accompanied by large increases in levels of phosphatidic acid (PA) and diacylglycerol (DAG). In contrast, desiccation and rewatering of P. mileense significantly decreased the level of monogalactosyldiacylglycerol and increased the unsaturation of membrane lipids, without changing the level of extraplastidic lipids. Lethal desiccation in P. mileense caused massive lipid degradation, whereas the PA content remained at a low level similar to that of fresh leaves. Neither damage nor repair processes, nor increases in PA, occurred during non-lethal desiccation in P. mileense. The activity of phospholipase D, the main source of PA, was much lower in P. mileense than in A. thaliana under control conditions, or after either dehydration or rehydration. It was demonstrated that low rates of phospholipase D-mediated PA formation in P. mileense might limit its ability to degrade lipids to PA, thereby maintaining membrane integrity following desiccation.

Plant lifespan is affected by factors with genetic and environmental bases. The laws governing these two factors and how they affect plant lifespan are unclear. Here we show that the acyl chain length (ACL) of phosphatidylserine (PS) is correlated with plant lifespan. Among the detected eight head-group classes of membrane lipids with lipidomics based on triple quadrupole tandem mass spectrometry, the ACL of PS showed high diversity, in contrast to the ACLs of the other seven classes, which were highly conserved over all stages of development in all plant species and organs and under all conditions that we studied. Further investigation found that acyl chains of PS lengthened during development, senescence, and under environmental stresses and that increasing length was accelerated by promoted- senescence. The acyl chains of PS were limited to a certain carbon number and ceased to increase in length when plants were close to death. These findings suggest that the ACL of PS can count plant lifespan and could be a molecular scale ruler for measuring plant development and senescence.

The natural anion exchange property of conducting polymer polypyrrole (PPY) was examined using solid phase microextraction (SPME) methods. Our preliminary results demonstrated that the anion exchange property of PPY could be utilized for direct SPME of anionic species from aqueous solutions without derivatization. This paper presents the first example of coupling SPME to ion chromatography (IC).

We design, fabricate and characterize dual-band terahertz (THz) metamaterial absorbers with high absorption based on a structures consisting of a cobalt silicide (Co-Si) ground plane, a parylene-C dielectric spacer and a metal top layer. By combining two periodic metal resonators that couple separately within a single unit cell, a polarization-independent absorber with two distinct absorption peaks was obtained. By varying the thickness of the dielectric layer, we obtain absorptivity of 0.76 at 0.76THz and 0.97 at 2.30THz, which indicates the Co-Si ground plane absorbers present good performance.

The association of plasma phospholipid (PL) fatty acid composition with plasma homocysteine (Hcy) in Chinese vegetarians is not understood. The main aim of the present study was to investigate the plasma PL fatty acid status, and its association with plasma Hcy in Chinese vegetarians and omnivores. A total of 103 male vegetarians and 128 male omnivores were recruited in Linyin Temple, Hangzhou. Plasma Hcy and PL fatty acid concentrations were determined by standard methods. Compared with omnivores, plasma PL n-3 PUFA (Pn-3 (Pn-6 (P= 0·021), 22 : 2n-6 (PP= 0·017) were significantly lower, while plasma PL n-6 PUFA (P= 0·007) and total PUFA (Pn-3 (r − 0·257, P= 0·046) was significantly negatively associated with plasma Hcy. In omnivores, plasma PL 18 : 1n-7 (r 0·237, P= 0·030) was significantly positively associated with plasma Hcy. Plasma PL 22 : 6n-3 (r − 0·217, P= 0·048) was negatively associated with plasma Hcy in omnivores. Plasma PL SFA were positively associated with the prevalence of HHcy. It would seem appropriate for vegetarians to increase their dietary n-3 PUFA and decrease dietary SFA, and thus reduce the risk of HHcy.

A large proportion of the Chinese population is now at risk of non-alcoholic fatty liver disease (NAFLD). We aimed to investigate the relationship between plasma phospholipids (PL) fatty acids and the risk of NAFLD. One hundred NAFLD patients and 100 healthy subjects were recruited in Hangzhou, China. Plasma PL and selected biochemical and hematological parameters were analyzed by using standard methods. Stepwise logistic regression was used to identify independent risk factors of NAFLD. Plasma PL total saturated fatty acid (SFA), C20:3n-6, serum alanine aminotransferase, high-density lipoprotein cholesterol, and body mass index were independent risk factors of NAFLD. The risk of NAFLD was significantly increased with higher quartiles of plasma PL total SFA (P for trend = 0.028) and C20:3n-6 (P for trend

The stereocontrolled synthesis of the amicetose/aculose disaccharide (VII) is achieved in six steps from acylfuran and involves two Luche and a diimide reduction.

In an effort to address the medicinal chemist's need for new synthetic methods for the preparation of unnatural carbohydrates, new de novo methods for carbohydrate synthesis have been developed. These routes use asymmetric catalysis to set the sugar absolute stereochemistry, a palladium-catalyzed glycosylation reaction to stereoselectively control the anomeric center, and subsequent diastereoselective post-glycosylation to install the remaining sugar stereocenters. The utility of this method has been demonstrated by the syntheses of several classes of mono-, di- and tri-saccharides.

[19377-75-4] C6H8O3 (MW 128.13) InChI = 1S/C6H8O3/c7-4-5(8)6-2-1-3-9-6/h1-3,5,7-8H,4H2 InChIKey = YOSOKWRRCVPEJS-UHFFFAOYSA-N [14086-08-9] (1R)-C6H8O3 (MW 128.13) InChI = 1S/C6H8O3/c7-4-5(8)6-2-1-3-9-6/h1-3,5,7-8H,4H2/t5-/m1/s1 InChIKey = YOSOKWRRCVPEJS-RXMQYKEDSA-N [61243-05-8] (1S)-C6H8O3 (MW 128.13) InChI = 1S/C6H8O3/c7-4-5(8)6-2-1-3-9-6/h1-3,5,7-8H,4H2/t5-/m0/s1 InChIKey = YOSOKWRRCVPEJS-YFKPBYRVSA-N (carbohydrate derivative, chiral furan diol, and six-carbon intermediate in carbohydrate and natural product syntheses) Alternate Names: 2-(1,2-dihydroxyethyl)-furan, 2-(d-glycero-1,2-dihydroxyethyl)furan. Physical Data: (1R)-1-(2-furanyl)-1,2-ethanediol; bp 83–85 ° (0.01 Torr); (c 3.3 CHCl3). Solubility: soluble in ether, tetrahydrofuran, ethyl acetate, benzene, methylene chloride, and ethanol; slightly soluble in water. Handling, Storage, and Precautions: 1-(2-furanyl)-1,2-ethanediol can form a stable endo-peroxide with singlet oxygen and can be exothermally polymerized under acidic conditions. It may irritate the eyes, the skin, and respiratory tract upon exposure. This reagent should be handled only in a fume hood. Purification: 1-(2-furanyl)-1,2-ethanediol can be distilled at reduced pressure and by silica gel chromatography. Preparative Methods: along with other furan products, the chiral furyl alcohol, (1R)-1-(2-furanyl)-1,2-ethanediol, is a by-product from the acid-catalyzed dehydration of the d-hexoses.1 Better yields of (1R)-1-(2-furanyl)-1,2-ethanediol occur when Hg(II) salts are used in the reaction (eq 1).2 When the biopolymer cellulose is used as the carbohydrate starting material, the mixture of furan products' primary utility is as a potential biofuel source1 and not a starting material for asymmetric synthesis. In addition to the problems with mixtures of furan products associated with the dehydration of the D-hexose, the (1R)-1-(2-furanyl)-1,2-ethanediol produced by these procedures is susceptible to acid-catalyzed racemization. Applying the acid-catalyzed dehydration reaction on advanced carbohydrate intermediates has been shown to skirt some of the problems associated with racemization and isomer formation. For instance, when the glucose derivative, d-glucal, is used in the dehydration procedure, better yields of (1R)-1-(2-furanyl)-1,2-ethanediol are produced with more reproducible enantiopurity (eq 2).3 Of course, other carbohydrate derivatives can be used to produce the enantiomeric product, (1S)-1-(2-furanyl)-1,2-ethanediol (eq 3).4 (1) (2) (3)

This paper presents the design, fabrication and performance of a bimaterial microcantilever focal plane array (FPA) of 256×256 pixels for uncooled infrared (IR) imaging. The microcantilevers made of silicon nitride (SiNx) and gold (Au) convert incident IR energy to a distribution of deflection angles among the FPA pixels according to the IR source, which is read out by an optical method. The thermo-mechanical sensitivity of the cantilever pixel was measured to be 147 nm/K. The noise equivalent temperature difference (NETD) of the FPA was theoretically estimated to be 130 mK and the response time was calculated to be 12 ms. Thermal image of the heated brand iron were captured by the fabricated FPA. The most valuable feature of the implemented FPA is their scalability to high resolution formats without progressively growing fabrication complexity and cost.

Poly(aryl ether ether ketone) is found to be compatible with poly(aryl ether sulfone) at a blending temperature 310°C. There is a single glass transition temperature (Tg) for various compositions of the blend. The relationship of Tg with composition obeys Gordon-Taylor's equation, where the adjustable parameter k is 0.43. Thermodynamic interaction parameter χ12 is estimated to be -0.001 according to Nishi and Wang's melting point depression equation. When the processing temperature is above 350°C, phase separation takes place as shown by a double mechanical loss tangent relaxations in the range of 100–280°C.

Two sequential palladium-catalyzed reactions, an intermolecular Stille cross-coupling followed by a recently developed palladium-catalyzed reductive N-heteroannulation, have been employed as the key synthetic steps toward six tetrahydrocarbazolones. The products are advanced intermediates toward a number of naturally occurring carbazole alkaloids.

This paper presents the design, fabrication and analysis of an infrared focal-plane array (FPA) consisting of bi-material cantilevers. The bi-material cantilevers are made of silicon nitride (SiNx) and aluminum (Al), and which will bend as the temperature changes due to the difference of the two materials in thermal expansion coefficients. In order to enhance the infrared (IR) absorption efficiency of the FPA, deep reactive ion etching (DRIE) technique was introduced to remove the backside Si of the structures. Therefore the IR light can reach the FPA directly. The thermomechanical sensitivity for the finished FPA is measured to be 0.134 μm/K by profile meter, and the noise-equivalent temperature difference (NETD) of the system was estimated to be 18mK.Copyright © 2007 by ASME

Gold-coated microcantilevers were used to develop sensitive micromechanical biosensor for detecting mismatch mutations in DNA hybrids. The selective 5'-end immobilization of 25-mer single-stranded (ss) DNA probes to a gold-coated cantilever surface and the specific hybridization of ssDNA targets to the immobilized probe were performed by the direct electric field control. The controlled electric fields were used to regulate the transport of charged oligo-nucleotides. More than 70% of the immobilization and hybridization can be carried out in 2-3 seconds, and the detection rates are at least 102 times faster than in the passive control reactions performed without electric field.

A method for full speciation and determination of alkyllead and inorganic lead(II) in aqueous samples was developed. This was accomplished by in situ derivatization with deuterium-labeled sodium tetraethylborate NaB(C2D5)4 (DSTEB). The derivatization was carried out directly in the aqueous sample and the derivatives were extracted from the headspace by a solid-phase microextraction (SPME) fiber. The extracted analytes were then transferred to a GC/MS or a GC/FID for separation and detection. The research presented demonstrates that SPME and the derivatization reagent DSTEB can be used successfully for the speciation of Pb2+, Pb(CH3)3+, Pb(C2H5)3+, and Pb(C2H5)4 in water samples. All derivatives, Pb(C2D5)4, (CH3)3Pb(C2D5), (C2H5)3Pb(C2D5), and Pb(C2H5)4, are separated using an SBP-5 column. This method was applied to monitor degradation of tetraethyllead in water. This is the first report of ethylation by DSTEB for full speciation of methyllead, ethyllead, and inorganic lead compounds. This approach can be extended to other organometallic compounds as demonstrated for ethyltin speciation. This full speciation method will aid in monitoring occurrence, pathways, toxicity, and biological effects of these compounds in the environment. It is easily adopted for field analysis.

Lead is the most frequently quantitated toxic metal in biological matrixes. In this paper, a method is described for lead determination in whole blood and urine using solid-phase microextraction (SPME) gas chromatography. Lead ion is first derivatized with sodium tetraethylborate to form tetraethyllead, which is then extracted from the headspace over the sample by SPME. The analytical procedure was optimized for coating selection, pH, extraction time, and effect of salt. The relative standard deviation was less then 10% for both urine and blood samples. The limit of detection was 3 and 4 ppb; the limit of quantification is 5 and 10 ppb for urine and blood samples, respectively. Good linearity was found for both urine and blood samples when PDMS coating was used. The standard addition method was used for quantitation. Certified urine and blood samples were analyzed, and good accuracy was obtained.

We design, fabricate, and characterize dual-band terahertz (THz) metamaterial absorbers with high absorption based on structures consisting of a cobalt silicide (Co-Si) ground plane, a parylene-C dielectric spacer, and a metal top layer. By combining two periodic metal resonators that couple separately within a single unit cell, a polarization-independent absorber with two distinct absorption peaks was obtained. By varying the thickness of the dielectric layer, we obtain absorptivity of 0.76 at 0.76 THz and 0.97 at 2.30 THz, which indicates the Co-Si ground plane absorbers present good performance.

A method for the asymmetric synthesis of the disaccharide portion of SCH-47554 has been developed in 6 steps. The route is shorter than the reported route to a related disaccharide. The route involves the use of the Noyori reduction to establish the asymmetry of the d- and l-sugar portion of the molecule. Diastereoselective Pd-glycosylation reaction and subsequent post-glycosylation transformation are used to establish the remaining stereocenter.

Biological macromolecules have been used to fabricate many nanostructures, biodevices and biomimetics because of their physical and chemical properties. But dynamic nanostructure and biomachinery that depend on collective behavior of biomolecules have not been demonstrated. Here, we report the design of DNA nanocompartments on surfaces that exhibit reversible changes in molecular mechanical properties. Such molecular nanocompartments are used to encage molecules, switched by the collective effect of Watson-Crick base-pairing interactions. This effect is used to perform molecular recognition. Furthermore, we found that 'fuel' strands with single-base variation cannot afford an efficient closing of nanocompartments, which allows highly sensitive label-free DNA array detection. Our results suggest that DNA nanocompartments can be used as building blocks for complex biomaterials because its core functions are independent of substrates and mediators.