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Dam is an important part of engineering structure, in the process of dam construction, the dam monitoring is crucial since water erosion and time-dependent motion may cause deformation. Traditional monitoring methods are time-consuming and labour-intensive. However, Interferometric Synthetic Aperture Radar (InSAR) can provide precise and spatially dense information on slow deformations. This research investigated the longest earth-rock-fill dam in Sudan to determine the spatial and temporal deformations Sentinel-1A descending SAR images were further used to analyse the issues mentioned above. The results suggested that the dam existed the maximum displacement with a value up to 190 mm on the dam crest. Besides, the selected sections along the riverbed of the dam were analysed and the RMSE was approximately 2 mm/year. The results were in good agreement with the in situ measurements, indicating the advancement of time series InSAR in dam deformation monitoring.

Osteoporosis has become a world-wide health problem. As a promising intervention, mechanical strain is considered to be an important factor in bone remodeling. However, the underlying mechanisms are still not clarified clearly. In the present study, we aim to investigate the possible mechanism by which mechanical stimulation induces osteogenic differentiation of bone mesenchymal stem cells (BMSCs) from ovariectomized rats (OVX BMSCs). The results demonstrated that intermittent mechanical strain (IMS) promoted osteogenic differentiation of OVX BMSCs by activating Runt-related transcription factor 2 (Runx2). When the extracellular regulated kinase1/2-mitogen activated protein kinases (ERK1/2-MAPK) signaling pathway was blocked, the osteogenenic effects of IMS were diminished; while blocking of the p38-MAPK signaling pathway had little effect on subsequent osteogenic events. In addition, the phosphorylation level of JNK was not affected by IMS. Our results indicated that strain-induced osteogenic differentiation of OVX BMSCs may take effect via ERK1/2-MAPK not p38 or c-Jun N-terminal (JNK)-MAPK signaling pathway. These findings may have implications for physical treatment of osteoporosis in vitro.

An initial study on WEDM process optimization for PCD micro milling tool has been carried out. With a orthogonal design of roughing and finishing condition experiment of PCD, a largest difference of WEDM parameter is obtained to calculate the influence of those parameter on cutting speed for roughing operation and surface roughness Ra and metamorphic layer thickness for finishing operation. For roughing operation, peak current and voltage pulse width are the dominant WEDM parameters; while for finishing operation, Peak current, peak voltage are the largest influence of parameters on cutting speed. With WEDM optimized parameters, a quadrilateral PCD micro milling tool is fabricated with CTB002 PCD material. Tool edge radius is 6.7 m.

Melting processes of a truncated icosahedral Cu135 cluster have been studied by employing molecular dynamics method based on the embedded-atom method (EAM) potential. The detailed information of structure and energy changes has been obtained by dividing Cu135 cluster into six shell regions according to radical density distribution peaks of atoms. The simulation results show that the melting behavior of the Cu135 cluster presents new pattern, its melting behaviors show similar to the bulk, there is definitive melting point (791K). Stable and particular surface structures of Cu135 cluster, which is identical structure with C60 cluster, play important role. The simulation results also show there is bigger internal strain in the Cu135 cluster and lower surface energy at 300K, and the internal strain gets release by the volume of the Cu135 cluster expanding with temperature rising.

Micro milling force is the main parameter in motoring dynamic cutting process. The natural frequency of dynamometer is the key factor in the accurate measurement of high speed milling force. In this paper, a new structure fixture is designed, and the natural frequency of the fixture is obtained by finite element methods. After optimizing the structure design, the fixture is produced for the force signal acquisition system, together with the forces transducer, signal acquisition card and the software based on the LabVIEW. The experiment shows that the design of the fixture can meet the requirements of force acquisition.

Relaxation and local structure changes of a molten Cu135 cluster have been studied by molecular dynamics simulation using embedded atom method when the cluster is rapidly quenched to 700K, 600K, 500K, 400K, 300K, 200K, and 100K. With decreasing quenching temperature, details of energy evolvement and relaxation are analyzed. The simulation results show that the final structures are molten at 700K, like-icosahedral geometry at 600K-200K, non-crystal at 100K. The average energy of atoms is the lowest at 500K, and in the relaxation has abrupt increase at 25,135 and 42ps separately at 400K, 300K, and 200K. The simulation reveals that the quenching temperature has great affect on the relaxation processes of the Cu135 cluster after β relaxation region.

Mitochondrial redox states provide important information about energy-linked biological processes and signaling events in tissues for various disease phenotypes including cancer. The redox scanning method developed at the Chance laboratory about 30 years ago has allowed 3D high-resolution (~50 × 50 × 10 μm3) imaging of mitochondrial redox state in tissue on the basis of the fluorescence of NADH (reduced nicotinamide adenine dinucleotide) and Fp (oxidized flavoproteins including flavin adenine dinucleotide, i.e., FAD). In this review, we illustrate its basic principles, recent technical developments, and biomedical applications to cancer diagnostic and therapeutic studies in small animal models. Recently developed calibration procedures for the redox imaging using reference standards allow quantification of nominal NADH and Fp concentrations, and the concentration-based redox ratios, e.g., Fp/(Fp+NADH) and NADH/(Fp+NADH) in tissues. This calibration facilitates the comparison of redox imaging results acquired for different metabolic states at different times and/or with different instrumental settings. A redox imager using a CCD detector has been developed to acquire 3D images faster and with a higher in-plane resolution down to 10 μm. Ex vivoimaging and in vivoimaging of tissue mitochondrial redox status have been demonstrated with the CCD imager. Applications of tissue redox imaging in small animal cancer models include metabolic imaging of glioma and myc-induced mouse mammary tumors, predicting the metastatic potentials of human melanoma and breast cancer mouse xenografts, differentiating precancerous and normal tissues, and monitoring the tumor treatment response to photodynamic therapy. Possible future directions for the development of redox imaging are also discussed.

We have imaged mitochondrial oxidation–reduction states by taking a ratio of mitochondrial fluorophores: NADH (reduced nicotinamide adenine dinucleotide) to Fp (oxidized flavoprotein). Although NADH has been investigated for tissue metabolic state in cancer and in oxygen deprived tissues, it alone is not an adequate measure of mitochondrial metabolic state since the NADH signal is altered by dependence on the number of mitochondria and by blood absorption. The redox ratio, NADH/(Fp + NADH), gives a more accurate measure of steady-state tissue metabolism since it is less dependent on mitochondrial number and it compensates effectively for hemodynamic changes. This ratio provides important diagnostic information in living tissues. In this study, the emitted fluorescence of mouse colon in situis passed through an emission filter wheel and imaged on a CCD camera. Redox ratio images of the healthy and hypoxic mouse intestines clearly showed significant differences. Furthermore, the corrected redox ratio indicated an increase from an average value of 0.51 ± 0.10 in the healthy state to 0.92 ± 0.03 in dead tissue due to severe ischemia (N = 5). We show that the CCD imaging system is capable of displaying the metabolic differences in normal and ischemic tissues as well as quantifying the redox ratio in vivoas a marker of these changes.

The fluorescence properties of reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavoproteins (Fp) including flavin adenine dinucleotide (FAD) in the respiratory chain are sensitive indicators of intracellular metabolic states and have been applied to the studies of mitochondrial function with energy-linked processes. The redox scanner, a three-dimensional (3D) low temperature imager previously developed by Chance et al., measures the in vivometabolic properties of tissue samples by acquiring fluorescence images of NADH and Fp. The redox ratios, i.e. Fp/(Fp+NADH) and NADH/(Fp+NADH), provided a sensitive index of the mitochondrial redox state and were determined based on relative signal intensity ratios. Here we report the further development of the redox scanning technique by using a calibration method to quantify the nominal concentration of the fluorophores in tissues. The redox scanner exhibited very good linear response in the range of NADH concentration between 165–1318 μM and Fp between 90–720 μM using snap-frozen solution standards. Tissue samples such as human tumor mouse xenografts and various mouse organs were redox-scanned together with adjacent NADH and Fp standards of known concentration at liquid nitrogen temperature. The nominal NADH and Fp concentrations as well as the redox ratios in the tissue samples were quantified by normalizing the tissue NADH and Fp fluorescence signal to that of the snap-frozen solution standards. This calibration procedure allows comparing redox images obtained at different time, independent of instrument settings. The quantitative multi-slice redox images revealed heterogeneity in mitochondrial redox state in the tissues.

Despite the numerous advantages offered by high-speed and high-performance cutting technologies, the issue of diminished tool life still remains profoundly concerning, especially in the case of machining hardened steels. Moreover, in finish machining, the requirement of improving workpiece surface finish also gains considerable importance. Application of the minimum quantity of lubrication (MQL) has delivered so many benefits that it has almost become part and parcel of turning, drilling, and milling technologies. In this research work, the high-speed milling of hardened cold work tool steel (62 HRc), under an MQL environment, was experimentally investigated and a response surface methodology was utilized to optimize the cutting parameters. A series of experiments was performed in order to quantify the effects of following three cutting parameters on tool life and arithmetic average surface roughness: cutting speed (Vc), feed rate (fz), and radial depth of cut (ae). The surface roughness was measured in two directions: along the feed, Ra, and along the pick-feed, Ra(pick). Analysis of variance (ANOVA) performed on the data revealed that the effect of cutting speed was significant on tool life as well as on Ra. Moreover, the effects of feed rate and radial depth of cut on tool life and Ra(pick) respectively were found to be significant. Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses were performed to determine the dependence of different tool damage modes on levels of cutting parameters utilized. It was found that chipping and adhesion were the dominant tool damage modes in most of the experimental runs and their severity was dependent on levels of feed rate and cutting speed respectively.

Land‐use change can lead to changes in soil carbon (C) and nitrogen (N) storage. This study aimed to determine the impact of long‐term grazing exclusion (GE) on soil organic C and total N (TN) storage in the Leymus chinensisgrasslands of northern China and to estimate the dynamics of recovery after GE. We investigated the aboveground biomass and soil organic C and TN storage in six contiguous plots along a GE chronosequence comprising free grazing, 3‐yr GE, 8‐yr GE, 20‐yr GE, 24‐yr GE, and 28‐yr GE. Grazing exclusion for two decades increased the soil C and N storage by 35.7 and 14.6%, respectively, in the 0‐ to 40‐cm soil layer. The aboveground net primary productivity and soil C and N storage were the highest with 24‐yr GE and the lowest with free grazing. The storage increased logarithmically with the duration of GE; after an initial rapid increase after the introduction of GE, the storage attained equilibrium after 20 yr. A logarithmic regression analysis revealed 86.8 and 87.1% variation in the soil C storage and 74.2 and 80.7% variation in the soil N storage in the 0‐ to 10‐cm and 0‐ to 40‐cm soil layers, respectively. Based on these results, we suggest that two decades of GE would restore the L. chinensisgrasslands from being lightly degraded to a stable productive condition with good soil C and N storage capacity. Our results demonstrated that by implementing GE, the temperate grasslands of northern China could facilitate significant C and N storage on decade scales in the context of mitigating global climate change.

To determine if plasma exchange combined with plasma perfusion is a reliable and effective temporary liver support treatment for patients on the waiting list for OLT, we tested this method in 5 patients with end-stage and 3 patients with middle-stage severe hepatitis. Four patients were successfully controlled until a donor liver was available 4 to 13 days later. In contrast, the remaining 4 patients were not adequately controlled by this treatment and experienced aggravated disease progression, dying 3 to 8 days after treatment while still awaiting OLT. Of those 4 patients who received OLT, 2 patients died from multi-organ failure caused by hepatic failure, while the other 2 survived. These findings show that plasma exchange combined with plasma perfusion provides temporary support for some patients on the waiting list for OLT. The ability of patients to successfully bridge to OLT is closely associated with the degree of liver failure, complications, multi-organ failure, and the length of the waiting period for a donor liver.

We report a method to prepare hydrophilic poly(dimethylsiloxane) (PDMS) stamps that could transfer patterns of polar molecules homogeneously in soft lithography. In this method, we demonstrated a two-step procedure by using a mixed gas of argon (Ar) and hydrogen (H2)-based microwave plasma pretreatment to activate PDMS and subsequent acrylonitrile grafting onto PDMS, generating a hydrophilic surface with cyano (−CN) group coatings. The PDMS hydrophilic surface exhibited high affinity for wetting acetonitrile, which is a conventional solvent for DNA synthesis. Acetonitrile droplets possessed contact angles as low as 17 ± 7° on the cyano (−CN) groups grafted PDMS stamps surface. The hydrophilicity was stable and could last for at least 1 month at room temperature. Attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectrum were used to characterize the surface hydrophilization. Such a hydrophilic and inert PDMS stamp showed significance for reactive multilevel fabrications in soft lithography. The possible chemical mechanism for PDMS surface grafting was discussed.

This paper describes the in situ synthesis of oligonucleotide arrays on glass surfaces by using soft lithography. In this method, based on the standard phosphoramidite chemistry protocol, the coupling was achieved by the glass slide being printed with a set of polydimethylsiloxane (PDMS) microstamps, on which was spread nucleoside monomer and tetrazole mixed solution. The elastic characteristic of PDMS allowed it to make conformal contact with the glass slide in the printing coupling. With regard to the efficiency of the printing coupling, the hybridization microscope images of 20-mer oligonucleotide synthesized via the directly drip-dropped coupling and the contact coupling were compared; the fluorescence intensities of the two methods showed no significant differences. The coupling efficiency was also investigated via an end-labelled fluorescence nucleotide method and a stepwise yield of 97&percent; was obtained. A high-quality, high spatial resolution and large-scale PDMS stamp, which was developed by integrating 168 different microstamps on one glass substrate for synthesizing oligonucleotide arrays. The stamp was modified to improve the surface wettability by plasma discharge treatments, so that microstamps could be used to fabricate oligonucleotide arrays. A motional printing head was developed to improve the contact effect of the glass slide with different microstamps. A higher boiling point solvent was used in the printing coupling to inhibit solvent volatilization and to maintain the consistency of reagents on different features of the microstamp. An effective method was used to eliminate residual reactive nucleosides on chips with small molecules containing a hydroxyl group. A specific oligonucleotide array of four probes both matched and mismatched with the target sequence was fabricated to identify the perfect match and mismatch sequences.

This paper describes the in situsynthesis of oligonucleotide arrays on glass surfaces by using soft lithography. In this method, based on the standard phosphoramidite chemistry protocol, the coupling was achieved by the glass slide being printed with a set of polydimethylsiloxane (PDMS) microstamps, on which was spread nucleoside monomer and tetrazole mixed solution. The elastic characteristic of PDMS allowed it to make conformal contact with the glass slide in the printing coupling. With regard to the efficiency of the printing coupling, the hybridization microscope images of 20-mer oligonucleotide synthesized via the directly drip-dropped coupling and the contact coupling were compared; the fluorescence intensities of the two methods showed no significant differences. The coupling efficiency was also investigated via an end-labelled fluorescence nucleotide method and a stepwise yield of 97% was obtained. A high-quality, high spatial resolution and large-scale PDMS stamp, which was developed by integrating 168 different microstamps on one glass substrate for synthesizing oligonucleotide arrays. The stamp was modified to improve the surface wettability by plasma discharge treatments, so that microstamps could be used to fabricate oligonucleotide arrays. A motional printing head was developed to improve the contact effect of the glass slide with different microstamps. A higher boiling point solvent was used in the printing coupling to inhibit solvent volatilization and to maintain the consistency of reagents on different features of the microstamp. An effective method was used to eliminate residual reactive nucleosides on chips with small molecules containing a hydroxyl group. A specific oligonucleotide array of four probes both matched and mismatched with the target sequence was fabricated to identify the perfect match and mismatch sequences.

Siliceous MCM-41 mesoporous materials and those possessing Fe, La, Al,respectively, were synthesized using water glass as silica source. Results from thermogravimetric analysis and other techniques showed us that Fe(III) or La(III) species was incorporated into framework. Owing to Fe–O or La–O bond longer than Si–O bond, Fe(III) or La(III) species was limited to insert into framework and transformed from tetrahedrally coordinated state to octahedrally coordinated state upon calcination to remove template.

The acidity of mesoporous materials FeSiMCM-41, LaSiMCM-41, SiMCM-41, AlSiMCM-41 and HAlSiMCM-41 has been investigated by microcalorimetric studies of the adsorption of ammonia and temperature programmed ammonia desorption method. In the initial stage, the acid strength sequence is SiMCM-41>HAlSiMCM-41>AlSiMCM-41>FeSiMCM-41>LaSiMCM-41, in agreement with that found for microporous molecular sieves materials. A small number of strong acid sites of SiMCM-41 may result from the aluminum impurity contained in the silica source material. The acid density sequence is HAlSiMCM-41>AlSiMCM-41>FeSiMCM-41>LaSiMCM-41≥SiMCM-41 and can be explained by the studies of existing states of trivalent atoms in these samples reported in previous work. Since some NH3-TPD plots of these samples show the profiles that could not be back to baseline at elevated temperature, the technique of microcalorimetric adsorption is preferable in studying these samples.

The movement of labeled concanavalin A (Con A) receptors in reconstituted human erythrocyte membranes was observed directly in an electron microscope, using an environmental stage that kept the sample fully hydrated at all experimental temperatures. Human erythrocyte membrane ghosts were spread on the air/water interface in a Langmuir trough. The surface monolayer film contained most native proteins and lipids of the erythrocyte membrane. The Con A receptors in the film were labeled with Con A-conjugated, 25-nm-diameter gold microspheres. Unsupported bilayer membranes were reconstituted by dipping a 1000-mesh grid through the labeled surface film. The reconstituted membrane samples were observed under low beam current and photographed by timed exposures with sensitive x-ray films. The total radiation per exposure was kept below the damage threshold of 5 X 10(-4) coulomb/cm2. The Con A-gold labels were observed to move in unison within local areas (domains) of the reconstituted membrane. The size of the domains and the velocity of the labels were measured as functions of temperature. The typical domain size was 10 micron2 and the typical velocity of the labels was 7 nm/sec. The minimum domain size and velocity were found at 17 degrees-28 degrees C. Reduction of the amount of cholesterol in the precursor erythrocyte membrane caused the domain velocity at 7 degrees C to decrease and the domain size to increase; the opposite effect was observed with cholesterol enrichment. The results indicate that the components of the erythrocyte membrane tended to form moving domains and that the motion was related to lipid phase separation in the bilayer.

Abstract: Objective: One hundred eighty-one (97 F, 84 M) unrelated healthy African-American subjects (aged 18–41 years) were phenotyped based on their dextromethorphan (DMP) O-demethylation ability. Methods: Each subject was given 15 mg DMP orally and collected 8-h urine. The concentrations of DMP and its metabolite dextrophan (DOP) were determined by HPLC with ultraviolet detection. Metabolic ratio (MR) was expressed as the ratio of DMP to DOP molar amount in urine. Results: The frequency distribution histogram of the MR was bimodal, and probit analysis of this frequency gave an antimode value of 0.34. Seven subjects [3.9%, 95% confidence interval (CI) 1.1%–6.7%] were classified as poor metabolizers (PMs). Conclusion: This deficient frequency is in complete agreement with the reported ones in two smaller investigations in the African-American populations.