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Iron is required for the Fe-S cluster assembly which occurs in chloroplasts, mitochondria, and cytosol and here we characterized 44 Fe-S cluster biosynthesis genes and investigated their expression profiles during different peach flowering stages. Quantitative real-time PCR analysis shows that the highest expression of most peach Fe-S cluster biosynthesis genes appeared in the full bloom stage. Also, the highest Fe accumulation occurred in the full bloom stage followed by beginning bloom, petal fall, and bud swell stages. Activities of nitrite reductase (NiR) and succinate dehydrogenase (SDH) were closely correlated to the flower Fe content, whereas the aconitase (ACO) activity kept steady during the whole flowering process. Moreover, shading treatment significantly reduced Fe accumulation and NiR, SDH, and ACO activities of the full blooming flowers. Seventeen Fe-S cluster biosynthesis genes were down-regulated in response to a shading treatment. In particular, plastid sulfur mobilization genes were sensitive to the shading treatment.

Copper (Cu2+) ion was determined at micro level by diethyldithiocarbamate (DDTC) spectrophotometry after temperature-dependent solid–liquid separation using N-butyl pyridinium hexafluorophosphate ([BPy]PF6) as a solid solvent and DDTC as an extractant. The results showed that ions can be extracted 100% by DDTC–[BPy]PF6 at pH = 10·20. The extracted species was neutral Cu(DDTC)mCl2 (m = 1) based on slope analysis in the Cu2+–[BPy]PF6–DDTC temperature-dependent solid–liquid separation system. The recovery of Cu2+ extracted into DDTC–[BPy]PF6 can be achieved using 2 mol L−1 HNO3 as stripping agents. Back extraction method was adopted for the detection and quantification of Cu2+ ions using the DDTC spectrometry. The calibration curve was Y = 0·00328 + 0·10279X (correlation coefficient = 0·99922), the linear calibration range was 7·68 × 10−2 0·768 μg mL−1 and the limit of detection was 1·28 × 10−2 μg mL−1 for Cu2+. In this method, the contents of Cu2+ in Tieguanyin tea were determined with relative stan...

Summary Background Peginterferon-α–based therapy frequently leads to neutropenia. It remains unclear whether neutropenia is associated with bacterial infection in chronic hepatitis C (CHC). Aim To evaluate the risk of bacterial infection and neutropenia in patients with CHC treated with peginterferon-α/ribavirin. Methods In all, 207 patients with CHC with (group A, n = 30) and without (group B, n = 177) baseline neutropenia were treated with peginterferon-α/ribavirin. Results Group A had significantly higher rates of moderate (

This case–control study aimed to evaluate the diagnostic application of urinary transforming growth factor (TGF) α and serum α-fetoprotein (AFP) in hepatocellular carcinoma (HCC). TGFα and AFP were determined in 90 pairs of age- and gender-matched patients with cirrhotic HCC and patients with cirrhosis alone and 60 healthy controls. The results indicated that TGFα and AFP levels in patients with HCC were higher than in those with cirrhosis alone or healthy controls (each P = 0.0001). Multivariate analysis indicated that TGFα (odds ratio (OR) 1.03, 95 % confidence interval (CI) 1.05–1.16) and AFP (OR 1.03, 95 % CI 1.01–1.06) were closely associated, in a dose-related fashion, with the development of HCC. The optimal cutoff values, determined with the receiver operating characteristic (ROC) curves, were 29 μg/g creatinine for TGFα and 100 ng/ml for AFP, respectively. The areas under ROC curve (AUC) were 0.74 for TGFα and 0.78 for AFP, respectively. Both biomarkers showed the same sensitivity (52.2 %), high specificity, high positive predictive value, and moderate positive likelihood ratio. Determination of both markers in parallel significantly increased the AUC (0.91) and diagnostic accuracy (92.2 %), with a high sensitivity (86.7 %), specificity (97.8 %), positive predictive value (PPV; 97.5 %), and moderate positive likelihood ratio (PLR; 39.4). Among 31 cirrhotic HCC with AFP ≤ 20 ng/ml, the calculated AUC for TGFα was 0.79, with a sensitivity of 64.5 %, specificity of 96.7 %, PPV of 87.0 %, and PLR of 19.5. In conclusion, urinary TGFα and serum AFP are complementary tumor markers for detection of HCC with low AFP production.

The above-ground organs of plants are covered by a cuticle, an extracellular membrane performing important physiological and ecological functions, that consists of the fatty acid-derived polymer cutin and waxes. In the cuticular wax of many species, including the leaves of Prunus laurocerasus, triterpenoids are found at high concentrations. This paper investigates the potential of Raman microspectroscopy for the simultaneous detection of structurally similar triterpenoids in plant cuticles. Relative composition analysis was first performed on artificial triterpenoid mixtures consisting of α-amyrin and oleanolic acid, as well as oleanolic acid and ursolic acid, the two triterpenoids abundantly found in the cuticles of P. laurocerasus. The different triterpenoids could be distinguished in the mixture spectra and the resulting calculated triterpenoid ratios were consistent with the expected values. Qualitative analysis of the Raman spectra of P. laurocerasus cuticle demonstrated the in situ detectability of the triterpenoids using this approach. It is shown here that Raman microspectroscopy has the potential to provide useful information concerning the spatial distribution of some key chemical components of plant cuticles. This technique thus offers a valuable complement to the current standard analytical methods used for analyzing the bulk composition of plant cuticles.

Vanadium pentoxide (V2O5) nanomaterials with various morphologies were prepared by chemical vapour deposition at a relatively low temperature (evaporation temperature of 250 °C and growth temperature of 500 °C) using vanadyl acetylacetonate (VO(acac)2) powder as the vanadium precursor. The obtained samples were characterized by scanning electron microscopy, x-ray diffraction, Raman scattering and photoluminescence spectra. The results revealed that the samples including a V2O5 nanocluster film, V2O5 nanowires and V2O5 nanospheres were synthesized at different distances from the source material. For our chemical vapour transport system, we suggested that VOx vapour and VO(acac)2 vapour existed simultaneously during the growth process, which resulted in different morphologies of V2O5 nanomaterials. The quite different supersaturation distributions of VOx vapour and VO(acac)2 vapour led to three main growth areas. The V2O5 film was grown in the region where the supersaturation of the VOx vapour was high, V2O5 nanowires were obtained where the supersaturation of the VOx vapour was relatively low and V2O5 nanospheres were synthesized in the region where the supersaturation of the VO(acac)2 vapour was high. The growth pressure that influenced the vapour concentration controlled the morphologies of the nanowires. It was found that a specific level of low concentration was necessary to ensure the growth of V2O5 nanowires.

We have measured the energy distributions of electrons field emitted from tungsten carbide, HfC〈100〉, and ZrC〈100〉 tips, and tungsten field emitters with diamondlike carbon coatings. Multiple‐peaked energy distributions were observed from instability induced emission sites on the carbide tips. Energy distributions of electrons field emitted from the diamondlike carbon coated tungsten tips were broader than those from metal tips. They also showed a shift towards lower energies with increases in the emission current.

We have evaluated the cold‐field‐emission characteristics of HfC〈100〉 and ultrasharp tungsten emitters. We found that proper acetylene treatment improved both the angular current confinement and the emission stability of thermally cleaned HfC〈100〉 tips. Stable emission exceeding 10 μA/sr for over 1 h and angular confinement to a 3° semicone angle have been observed. The improvements are probably related to the modified work function and surface chemical composition induced by the acetylene treatment at the tip apex. Carburization of W〈100〉 and W〈111〉 tips also significantly improved the emission current stability. This study indicates the usefulness of surface processing in the development of cold‐field emitters.

The transport of ATP out of mitochondria and uptake of ADP and Pi into the matrix are coupled to the uptake of one proton (Klingenberg, M., and Rottenberg, H. (1977) Eur. J. Biochem. 73, 125--130). According to the chemiosmotic hypothesis of oxidative phosphorylation this coupling of nucleotide and Pi transport to proton transport implies that the P/O ratio for the synthesis and transport of ATP to the external medium is less than the P/O ratio for the synthesis of ATP inside mitochondria. A survey of previous determinations of the P/O ratio of intact mitochondria showed little convincing evidence in support of the currently accepted values of 3 with NADH-linked substrates and 2 with succinate. We have measured P/O ratios in rat liver mitochondria by the ADP pulse method and by 32 Pi esterification, measuring oxygen uptake with an oxygen electrode, and find values close to 2 with beta-hydroxybutyrate as substrate and 1.3 with succinate as substrate in the presence of rotenone to inhibit NADH oxidation. These values were largely independent of pH, temperature, Mg2+ ion concentration, Pi concentration, ADP pulse size, or amount of mitochondria used. We suggest that these are the true values of the P/O ratio for ATP synthesis and transport by mitochondria, and that previously reported higher values resulted from errors in the determination of oxygen uptake and the use of substrates which lead to ATP synthesis by succinate thiokinase.

Secondary ion mass spectrometry (SIMS), low energy electron diffraction (LEED), and Auger electron spectroscopy (AES) have been employed to study the interactions of silane and phosphine with the Si(100) surface. Phosphine adsorption and desorption were investigated at surface temperatures in the range . At ambient temperature, phosphine saturated the bare Si(100) surface after 3–5L exposure, and fitting adsorption data to a Langmuir model yields the value for the sticking coefficient. Phosphine adsorption was found to follow the pattern of the underlying silicon. Competitive adsorption experiments set an upper bound of for silane adsorption under like conditions. The silicon surface was observed to be passivated with respect to silane adsorption by prior exposure to phosphine, with a layer of preferentially adsorbed phosphine formed which served to preclude subsequent silane adsorption. The results obtained here are discussed in the context of their bearing upon the phosphorus‐doped low pressure chemical vapor deposition process.

Particulate and sulfate emission characteristics of two catalyzed radial-flow wire-mesh particulate traps are presented. The traps were found to be ineffective for particulate reduction. The first trap was dynamometer tested for 25 consecutive EPA Heavy Duty Diesel Transient Cycles and 40 hours of steady-state operation. During steady state testing, particulates were sampled from both the raw and diluted engine exhaust. The total particulate matter was chemically analyzed for sulfate, organic, moisture, and nonextractable fractions. The data indicate significant conversion of fuel sulfur to hygroscopic sulfuric acid. Although solid carbon fraction was reduced, total particulate mass increased. Sulfuric acid condensation presented operational and particulate sampling difficulties. Sampling from the raw exhaust with heated lines showed good sulfur balance between fuel and exhaust contents, but sulfate emission also exceeded the baseline for total particulate matter. Steady-state tests with a second trap with a different catalyst formulation produced similar results and no improvement in total particulate emissions.

The impact of diesel fuel sulfur reduction on directly-emitted and secondary atmospheric particulate is evaluated by experiment and analysis. Experimental evidence shows that fuel sulfur conversion rate to particulate sulfate is linear down to zero sulfur level. Analysis shows that sulfur-derived particulate accounts for the vast majority of atmospheric particulate from diesel engines. Consequently, fuel sulfur reduction would have a far greater impact in reducing atmospheric particulate burden than any other diesel engine particulate control strategy.

Secondary ion emission during sputtering depends very much on the local atomic environments of the sputtered atoms. For example, sputtering with 02 + significantly enhances positive ion formation [1]. This enhancement is attributed to the incorporation of oxygen atoms in the target. The formation of the oxide bonds intensifies the secondary ion yields. In this experiment we moved a step further and tried to see whether the presence of a second metallic component in the sample could influence this oxygen enhancement effect. We also tried to look for any corresponding changes in the oxide bonds with X-ray photoemission (XPS). We examined two alloy systems: CrNi and AgPd. Both Cr and Ni form strong oxides, while both Ag and Pd form weak ones.