Field Experimental Study on Corrosion Mechanism of Well Lai 14-9

Casing corrosion is serious and the injection efficiency is considerably low due to high injecting water corrosion in Well Lai 14-9. Casing corrosion mechanism is retrieved through SEM observation, energy spectrum analysis, XRD analysis spectrum, TGA analysis of corrosion fouling. The results show casing corrosion mechanism varies with depths; casing corrosion is the result of the combined action of carbon dioxide, dissolved oxygen, sulfate-reducing bacteria and high salinity. To extend the life of casing, appropriate casing protection measures should be adopted, which can reduces the cost of production of the oilfield.Key words: Corrosion mechanism; Fouling; SEM observation; XRD analysis spectrum; TGA analysi

Bone remodeling at microscrew interface near extraction site in the beagle dog mandible-histologic and immunohistochemical analyses

Extraction is often used as part of orthodontic therapy, and good control of anchorage is a key step after extraction. Although microscrews can be implanted close to the extraction site in order to achieve orthodontic support, the efficiency of bone remodeling at the implant-bone interface near the extraction region is dubious. OBJECTIVE: The purpose of this study was to investigate bone remodeling of the bone-microscrew interface near the tooth extraction site, in the absence of loading. MATERIAL AND METHODS: Third and fourth premolars were extracted from the mandibles of beagle dogs, followed by placement of test microscrews near the extraction sites. Control microscrews were placed further away from the extraction site. All samples were collected after 1, 3, 8, or 12 weeks of healing following extraction. The bone remodeling process at the interface was evaluated using histologic and immunohistochemical analyses. RESULTS: Initially, a large number of inflammatory cells were aggregated at the interface. The expression levels of core binding factor (Cbfa1), osteocalcin (OC) and transforming growth factor beta (TGF-β) were inconspicuous in both groups, whereas tumor necrosis factor alpha (TNF-α) was strongly expressed, especially in the test groups (

Construction of genetic map in barley using sequence-related amplified polymorphism markers, a new molecular marker technique

Sequence-related amplified polymorphism (SRAP) markers, a novel polymerase chain reaction (PCR)-based molecular marker technique, were successfully applied in map construction, cultivar identification, diversity evaluation, comparative genomics and gene location of different plant species. The molecular genetic map of SRAP markers in Steptoe / Morex doubled haploid (DH) population was constructed in this study, using 216 SRAP markers and 312 simple sequence repeat (SSR) markers. Overall, 21 of the 216 SRAP markers generated 78 polymorphic loci, and 98 of 312 SSR markers produced 107 polymorphic loci. Among the 185 loci, 175 loci (70 SRAP loci and 105 SSR loci) were assigned to nine linkage groups. The map covered 1475 cM with a mean density of 8.7 cM per locus. In total, 33 of all the loci (17.84%) showed significant segregation distortion. Moreover, 23 of the 33 loci (69.7%) skewed towards the parent Steptoe, whereas the remaining loci (21.3%) deviated towards the parent Morex and some of these distorted loci tended to cluster at the end of linkage groups, while others were dispersed on linkage groups in a decentralized fashion. The three putative segregation distortion regions (SDRs) were detected on chromosomes 2H, 4H and 5H, respectively. This linkage map indicates its importance in quantitative trait loci (QTLs) mapping, marker-assisted selection (MAS) and integrative analysis for further genetic studies with other linkage maps in barley.Keywords: Barley, sequence-related amplified polymorphism (SRAP), molecular genetic map, simple sequence repeat (SSR), doubled haploid (DH) populatio

Complex emulsions for shape control based on mass transfer and phase separation

Complex emulsions are used to fabricate new morphologies of multiple Janus droplets, evolving from non-engulfing to complete engulfing core/shell configuration. The produced droplets contain an aqueous phase of dextran (DEX) solution and an oil phase, which is mixed with ethoxylated trimethylolpropane triacrylate (ETPTA) and poly(ethylene glycol) diacrylate (PEGDA). The PEGDA in the oil phase is transferred into the aqueous phase to form complex morphologies due to the phase separation of PEGDA and DEX. The effects are investigated including the ratio of oil to aqueous phase, the content of initial PEGDA, DEX and surfactants, and the type of surfactants. DEX/PEGDA-ETPTA core/shell-single phase Janus droplets are formed with an increasing engulfed oil droplet into the aqueous droplet while the ratio of oil to aqueous phase increases or the initial PEGDA content increases. The high DEX content leads to the DEX-PEGDA-ETPTA doublet Janus. The use of surfactants polyglycerol polyricinoleate (PGPR) and Span 80 results in the formation of DEX/PEGDA/ETPTA single core/double shell and DEX/PEGDA-ETPTA core/shell-single phase Janus droplets, respectively. These complex emulsions are utilized to fabricate solid particles of complex shapes. This method contributes to new material design underpinned by mass transfer and phase separation, which can be extended to other complex emulsion systems

Association of gamma-tocopherol serum concentrations and blood pressure among adults in the United States: a cross-sectional study

Backgroundhypertension is one of the major preventable risk factors for numerous diseases. The role of vitamin E in blood pressure (BP) has been controversial. We aimed to investigate the relationship between gamma-tocopherol serum concentration (GTSC) and BPMethodsData from 15,687 US adults from the National Health and Nutrition Examination Survey (NHANES) were analyzed. The correlations of GTSC with systolic BP (SBP), diastolic BP (DBP), and prevalence of hypertension were investigated by multivariate logistic regression models, generalized summation models, and fitted smoothing curves. Subgroup analyses were performed to investigate possible effect modifiers between them.ResultsWith each natural log increase in GTSC, SBP, and DBP increased by 1.28 mmHg (β 1.28, 95% CI 0.71–1.84) and 1.15 mmHg (β 1.15, 95% CI 0.72–1.57), respectively, both P for trend < 0.001; the prevalence of hypertension increased by 12% (OR 1.12, 95% CI 1.03–1.22), P for trend 0.008. In subgroup analysis, in drinkers, with each natural log increase in GTSC, SBP, and DBP increased by 1.77 mmHg (β 1.77,95% CI 1.13–2.41) and 1.37 mmHg (β 1.37,95% CI 0.9–1.85), respectively, whereas they were not correlated in non-drinkers.ConclusionGTSC was linearly and positively associated with SBP, DBP, and the prevalence of hypertension, and alcohol consumption may modify the relationship of GTSC with SBP and DBP

Protective Effect and Mechanism of Chinese Yam Total Protein on High D-Glucose Induced Oxidative Stress in Human Umbilical Vein Endothelial Cells

To explored the protective effect and mechanism of Chinese yam total protein in human umbilical vein endothelial cells (HUVECs) with high-concentration D-glucose (HG)-induced oxidative stress injury. The HUVECs injury model was established by 50 mmol/L HG. HUVECs were randomly divided into control, model, low-dose Chinese yam total protein (0.5 mg/mL), and high-dose Chinese yam total protein (1 mg/mL) groups. The effects of Chinese yam total protein on the viability, morphology, and angiogenetic ability of HUVECs treated with HG were evaluated. The reactive oxygen species (ROS) level, superoxide dismutase (SOD) and catalase (CAT) activities in cells were determined. The nitric oxide (NO), 8-hydroxy deoxyguanosine (8-OHdG), malondialdehyde (MDA), interleukin-1β (IL-1β), and interleukin-6 (IL-6) levels in culture medium supernatant were measured. Protein expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), thioredoxin-interacting protein (Txnip), NOD-like receptor protein 3 (NLRP3), cleaved Caspase-1, and IL-1β were determined. The results showed that Chinese yam total protein could significantly increased the cell viability of HUVECs treated with HG (P<0.01), improved cell apoptotic morphology, and significantly increased the activities of SOD and CAT (P<0.05, P<0.01) and ratio of apoptosis-related proteins (Bcl-2/Bax), angiogenetic ability and nitric oxide (NO) secretion. Moreover, Chinese yam total protein significantly decreased the levels of ROS, MDA, 8-OHdG, IL-1β, and IL-6 (P<0.05, P<0.01) and the expression levels of inflammation-related proteins (Txnip, NLRP3, cleaved Caspase-1, and IL-1β) (P<0.05, P<0.01). Changes in these indicators showed a significant concentration-dependent manner. The results indicate that Chinese yam total protein may protect against HG-induced oxidative stress by inhibiting the Txnip/NLRP3 signaling pathway, restoring the oxidative balance, and reducing the inflammatory response of HUVECs

Mechanism of intercalation and deintercalation of lithium ions in graphene nanosheets

Graphene nanosheets (GNSs) were synthesized by reducing exfoliated graphite oxides. Their structure, surface morphology and lithium storage mechanism were characterized and investigated systematically using X-ray diffraction, atomic force microscopy, scanning electron microscopy, charge-discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. It was found that the GNSs, which were obtained via chemical synthesis, were primarily less than 10 graphene layers. The GNS electrodes, which were fabricated from the reduced GNSs, exhibited an enhanced reversible lithium storage capacity and good cyclic stability when serving as anodes in lithium-ion batteries. Also, the first-cycle irreversible capacities of the system were relatively high, because of the formation of a solid electrolyte interphase film on the surface of the GNS electrode and the spontaneous stacking of GNSs during the first lithiation. The electrochemical impedance spectroscopy results suggest that the solid electrolyte interphase film on the GNS electrode during first lithiation were primarily formed at potentials between 0.95 and 0.7 V. Also, the symmetry factor of the charge transfer was measured to be 0.446.Fundamental Research Funds for the Central Universities[2010LKHX03, 2010QNB04, 2010QNB05]; China University of Mining Technology[ON090237

Influences of Canopy Nitrogen and Water Addition on AM Fungal Biodiversity and Community Composition in a Mixed Deciduous Forest of China

Nitrogen (N) deposition and precipitation could profoundly influence the structure and function of forest ecosystems. However, conventional studies with understory additions of nitrogen and water largely ignored canopy-associated ecological processes and may have not accurately reflected the natural situations. Additionally, most studies only made sampling at one time point, overlooked temporal dynamics of ecosystem response to environmental changes. Here we carried out a field trial in a mixed deciduous forest of China with canopy addition of N and water for 4 years to investigate the effects of increased N deposition and precipitation on the diversity and community composition of arbuscular mycorrhizal (AM) fungi, the ubiquitous symbiotic fungi for the majority of terrestrial plants. We found that (1) in the 1st year, N addition, water addition and their interactions all exhibited significant influences on AM fungal community composition; (2) in the 2nd year, only water addition significantly reduced AM fungal alpha-diversity (richness and Shannon index); (3) in the next 2 years, both N addition and water addition showed no significant effect on AM fungal community composition or alpha-diversity, with an exception that water addition significantly changed AM fungal community composition in the 4th year; (4) the increment of N or water tended to decrease the abundance and richness of the dominant genus Glomus and favored other AM fungi. (5) soil pH was marginally positively related with AM fungal community composition dissimilarity, soil NH4+-N and N/P showed significant/marginal positive correlation with AM fungal alpha-diversity. We concluded that the effect of increased N deposition and precipitation on AM fungal community composition was time-dependent, mediated by soil factors, and possibly related to the sensitivity and resilience of forest ecosystem to environmental changes