Effects of Homogenization Heat Treatment on the Fe Micro-Segregation in Ti-1023 Titanium Alloy.

The segregation of the Fe element in Ti-10V-2Fe-3Al titanium alloy (Ti-1023) can lead to the generation of beta flecks, which seriously affects the performance of Ti-1023 products. During the heat treatment (HT) process at a high temperature, the Fe element in Ti-1023 ingots will migrate, making its distribution more uniform and reducing the segregation index. In this paper, the control of Fe micro-segregation in Ti-1023 ingots by homogenization HT was investigated. Firstly, dissection sampling and SEM-EDS analysis methods were used to study the distribution pattern of the Fe element in the equiaxed grains in the core of Ti-1023 ingots. It was found that the Fe content in the grain gradually increased along with the radial direction from the core to the grain boundary. Then, the homogenization HT experiments and numerical simulations of Ti-1023 at different HT temperatures from 1050 °C to 1200 °C were carried out. The results showed that the uniformity of Fe element distribution within grain can be significantly improved by the homogenization HT. With increasing HT temperature, Fe atoms migration ability increases, and the uniformity of Fe element distribution improves. Homogenization HT at 1150 °C and 1200 °C for 12 h can effectively reduce the degree of Fe element segregation.

LncRNA SNHG5 promotes the glycolysis and proliferation of breast cancer cell through regulating BACH1 via targeting miR-299.

BACKGROUND: Breast cancer (BC) is one of the most common malignant tumors in women. Accumulating studies have been reported that long non-coding RNA (lncRNA) SNHG5 is highly expressed in BC. However, the specific molecular mechanism of SNHG5 in BC is unclear. METHODS: Gene and protein expressions in BC cell were detected by qRT-PCR and western blotting. The proliferation and cell cycle were measured using colony formation assay and flow cytometry analysis, separately. The glucose consumption and lactate production were determined by using the glucose assay kit and lactate assay kit. A dual-luciferase reporter assay was performed to measure the interaction between miR-299 and SNHG5 or BACH1. RESULTS: SNHG5 and BACH1 expressions were increased in BC cell while miR-299 level was decreased. SNHG5 increased BACH1 expression by directly targeting miR-299. SNHG5 silencing or miR-299 overexpression suppressed the proliferation of BC cell, arrested the cell cycle in the G1 cell phase, and decreased the glucose consumption and lactate production of BC cell. However, inhibition of miR-299 or overexpression of BACH1 could reverse the inhibitory effects of sh-SNHG5 on cell proliferation and glycolysis in BC. CONCLUSION: SNHG5 promoted the BC cell growth and glycolysis through up-regulating BACH1 expression via targeting miR-299. These findings may improve the diagnostic and therapeutic approaches to BC.

Kaempferol blocks neutrophil extracellular traps formation and reduces tumour metastasis by inhibiting ROS-PAD4 pathway.

Kaempferol (kaem) is a dietary flavonoid found in a variety of fruits and vegetables. The inhibitory effects of kaem on primary tumour growth have been extensively investigated; however, its effects on tumour metastasis are largely unknown. In the present study, we found that kaem significantly suppresses both primary tumour growth and lung metastasis in mouse breast tumour model. Furthermore, decreased expression of citrullinated histone H3 (H3-cit), a biomarker of neutrophil extracellular traps (NETs), had been founded in metastatic lung upon treated with kaem. The reduction of H3-cit is not, however, due to the cytotoxicity of kaem on neutrophils since the frequency of CD11b+ Ly6G+ neutrophils did not change in lung, tumour or blood in the presence of kaem. We then confirm the anti-NETs effects of kaem in vitro by co-culturing mouse neutrophils and kaem. Supplementing the neutrophils with GSK484, a potent NET inhibitor, totally abrogated the inhibitory effects of kaem on tumour metastasis while having little or no impact on primary tumour growth, indicating the specificity of kaem acting on NET formation and tumour metastasis. We also found that kaem suppressed ROS production in mouse bone-marrow derived neutrophils. Supplementing with the ROS scavenger DPI abrogated kaem's effects on NET formation, suggesting the involvement of kaempferol in NADPH/ROS-NETs signalling. Finally, we applied the kaem on NET-deficient PAD4-/- mice and found decreased primary tumour volume and weight but similar lung metastatic tumour with kaempferol treatment. Therefore, our findings reveal a novel mechanism of kaem in breast cancer development by targeting NETs induced tumour metastasis.

Noninvasive and real-time pharmacokinetics imaging of polymeric nanoagents in the thoracoepigastric vein networks of living mice.

Noninvasive and real-time visualization of the thoracoepigastric veins (TVs) of living mice was demonstrated by using two-photon excitation (TPE) optical imaging with a Eu-luminescent polymeric nanoagent as the angiographic contrast. The spatiotemporal evolution of the polymeric nanoagent in TVs was monitored for up to 2 h by TPE time-resolved (TPE-TR) bioimaging, which is free from the interference of tissue autofluorescence. A wide field-of-view covering the thoracoabdominal region allowed the visualization of the entire TV network with an imaging depth of 1 to 2 mm and a lateral resolution of 80 µm at submillimeter. Detailed analysis of the uptake, transport, and clearance processes of the polymeric nanoagent revealed a clearance time constant of ∼30 min and an apparent clearance efficiency of 80% to 90% for the nanoagent in both axial and lateral TVs. TPE-TR imaging of the dissected internal organs proved that the liver is mainly responsible for the sequestration of the nanoagent, which is consistent with the apparent retention efficiency of liver, ∼32 % , as determined by the real-time in vivo TV imaging. We demonstrate the potency of TPE-TR modality in the pharmacokinetics imaging of the peripheral vascular systems of animal models, which can be beneficial for related nanotheranostics study.

Uptake and Translocation of Styrene Maleic Anhydride Nanoparticles in Murraya exotica Plants As Revealed by Noninvasive, Real-Time Optical Bioimaging.

This work reports the in vivo uptake and translocation of PNPs in the one-year grown terrestrial plant, Murraya exotica ( M. exotica), as investigated by two-photon excitation and time-resolved (TPE-TR) optical imaging with a large field of view (FOV, 32 × 32 mm2) in a noninvasive and real-time manner. The PNPs (⟨ Rh⟩ = 12 ± 4.5 nm) synthesized from poly(styrene- co-maleic anhydride) (SMA) were Eu-luminescence labeled (λL ≈ 617 nm). On exposing the roots of living M. exotica plants to the colloidal suspension of SMA PNPs at different concentrations, the spatiotemporal evolution of SMA PNPs along plant stems (60 mm in length) were monitored by TPE-TR imaging, which rendered rich information on the uptake and translocation of PNPs without any interference from the autofluorescence of the plant tissues. The TPE-TR imaging combined with the high-resolution anatomy revealed an intercell-wall route in the lignified epidermis of M. exotica plants for SMA PNP uptake and translocation, as well as the similar accumulation kinetics at different positions along the plant stems. We modeled the accumulation kinetics with Gaussian distribution to account for the trapping probability of a SMA PNP by the lignified cell walls, allowing the statistical parameters, the average trapping time ( tm) and its variance (σ), to be derived for the quantification of the PNP accumulation in individual plants. The TPE-TR imaging and the analysis protocols established herein will be helpful in exploring the mechanism of plant-PNP interaction under physiological condition.

Wide field of view, real time bioimaging apparatus for noninvasive analysis of nanocarrier pharmacokinetics in living model animals.

Understanding nanocarrier pharmacokinetics is crucial for the emerging nanopharmacy, which highly demands noninvasive and real-time visualization of the in vivo dynamics of nanocarriers. To this end, we have developed a 2-photon excitation and time-resolved (TPE-TR) bioimaging apparatus for the analysis of the spatial distribution and temporal evolution of nanocarriers in living model animals. The specific polymeric nanocarrier, Eu@pmma-maa doped with Eu-complexes luminescing in long persistence at ∼615 nm upon near-infrared 2-photon excitation, allows the complete rejection of tissue autofluorescence by selective luminescence detection. This together with a unique beam shaping scheme for homogeneous line excitation, a delicate timing strategy for single-shot line scanning, and an equal optical path design for in-plane scan endows the TPE-TR apparatus with the following prominent features: an imaging depth of ∼10 mm, a field of view (FOV) of 32 × 32 mm2 along with a horizontal resolution of ∼60 µm, a sub-10 s frame time, and negligible laser heating effect. In addition, a combination of the in-plane line scan with the 3D scan of a model animal offers the convenience for examining an interested FOV with a millimeter vertical resolution. Application of TPE-TR bioimaging to a living mouse reveals rich information on the dynamics of nanocarriers including the spatial distribution and temporal evolution and the kinetics of domains of interest. The noninvasive TPE-TR bioimaging instrumentation with a wide FOV and a large imaging depth will find applications in the pharmaceutical development of nanocarriers and relevant research fields.

Effect of initial solution pH on photo-induced reductive decomposition of perfluorooctanoic acid.

The effects of initial solution pH on the decomposition of perfluorooctanoic acid (PFOA) with hydrated electrons as reductant were investigated. The reductive decomposition of PFOA depends strongly on the solution pH. In the pH range of 5.0-10.0, the decomposition and defluorination rates of PFOA increased with the increase of the initial solution pH. The rate constant was 0.0295 min(-1) at pH 10.0, which was more than 49.0 times higher than that at pH 5.0. Higher pH also inhibits the generation of toxic intermediates during the PFOA decomposition. For example, the short-chain PFCAs reached a lower maximum concentration in shorter reaction time as pH increasing. The peak areas of accumulated fluorinated and iodinated hydrocarbons detected by GC/MS under acidic conditions were nearly 10-100 times more than those under alkaline conditions. In short, alkaline conditions were more favorable for photo-induced reduction of PFOA as high pH promoted the decomposition of PFOA and inhibited the accumulation of intermediate products. The concentration of hydrated electron, detected by laser flash photolysis, increased with the increase of the initial pH. This was the main reason why the decomposition of PFOA in the UV-KI system depended strongly on the initial pH.

Short- and long-chain perfluorinated acids in sewage sludge from Shanghai, China.

Perfluorinated acids (PFAs) are the subject of increasingly intense environmental research. In this study, sewage sludge samples were collected from 25 wastewater treatment plants (WWTPs) in Shanghai, China to evaluate the levels and profile of C3-C14 PFAs. The results showed a ubiquitous PFAs contamination of sewage sludge in Shanghai with the total PFAs (∑PFAs) range of 126-809 ng g(-1)dw. Perfluorooctanoic acid (PFOA) was found to be the dominant PFA pollutant and its concentration ranged from 23.2 to 298 ng g(-1)dw, much higher than the levels in other countries. Moreover, concentrations of short-chain PFAs (

[Method development for analysis of short-and long-chain perfluorocarboxylates in sewage].

A method using weak anion exchange cartridge for solid phase extraction before high performance liquid chromatography-negative electronspray ionization-tandem mass spectrometry [WAX-SPE + HPLC-ESI(-)-MS/MS] detection has been developed to measure C2-C14 perfluorocarboxylates (PFCAs) in sewages. When the weak anion exchange (WAX) cartridges were used for solid phase extraction (SPE), the better recoveries of short- and long-chain PFCAs (C2-C14) were achieved as the sewage samples were acidified to pH = 3.0 by formic acid, 2% formic acid was used for washing solvent and 1% ammonium hydroxide in methanol was used for elution solvent. The WAX cartridges used for SPE overcame the disadvantages of reverse phase solid phase extraction cartridges, i.e. the recoveries of short-chain PFCAs (C2-C5) were very low. The validity of this method was demonstrated by determination of short- and long-chain PFCAs (C2-C14) in influent of municipal wastewater treatment plant A and B in Shanghai, China. The results indicate that the recoveries of all PFCAs in influent of plant A and B are 56%-121% and 54%-120%, respectively; the recovery relative standard deviations (RSD) of plant A and B are < 11% and < 14%, respectively; and the method detection limits (MDL) and method quantitation limits (MQL) are 0.2-1.0 ng/L and 1.0-5.0 ng/L, respectively. In addition, the perfluorooctanoate (743 ng/L and 837 ng/L, respectively) and trifluoroacetic acid (139 ng/L and 489 ng/L, respectively) are the most and the second most PFCAs found in both plant A and B.

[Toxicological study of PFOS/PFOA to zebrafish (Danio rerio) embryos].

Acute toxicity of PFOS/PFOA to zebrafish (Danio rerio) and development effects to zebrafish embryo were examined using a zebrafish embryo test. PFOS/PFOA showed remarkably toxicity effects on zebrafish. The LC50 (48 h) values are 1 005 mg/L for PFOA, 107 mg/L for PFOS, while the LC50 (96 h) values are 499 mg/L for PFOA, 71 mg/L for PFOS. Moreover PFOS/PFOA inhibited embryo development, and caused embryo abnormality and death. After exposure to high concentration of PFOS (> 240 mg/L), cells in animal pole of embryos autolyzed to coagulate, which indicated PFOS caused cell membranes damage. The most sensitive endpoints for PFOS exposure is spinal column malformation, and the EC50 values is 9.14 mg/L. While for PFOA hatching (96 h) is the most sensitive, and the EC50 values is 328.0 mg/L. Both PFOS and PFOA retarded embryo development which indicates their development toxicity.

[Sorption behavior of bisphenol A on anaerobic sludge].

Batch experiments were conducted to investigate the sorption behavior of bisphenol A (BPA) with low concentration on anaerobic sludge. The autoclaved inactivated sludge was used to minimize the influence of degradation of activated sludge. The results showed that the sorption of BPA on anaerobic sludge was a quick process. Anaerobic sludge had achieved 89.1% of the maximum sorption capacity at 15 min. The sorption isotherms of BPA were fitted well by Freundlich and linear sorption models. The sorption coefficients normalized by organic carbon contents were in the range of 665-878 at 10-30 degrees C. MLSS had significant effect on the sorption behavior. With the increase in MLSS, the sorption removal efficiency increased. Through the determination of thermodynamics parameters of BPA, it can be concluded that the sorption of BPA on the anaerobic sludge was mainly a physical process and partitioning between the water and sludge phases played a dominant role. Desorption tests showed that BPA sorption on anaerobic sludge was partially reversible.

[Biodegradability and degradation mechanism of 3-fluorophenol by the activated sludge].

An acclimated activated sludge was examined for its ability to degrade 3-fluorophenol in aerobic batch cultures. The result indicated that the organism degrades up to 100 mg/L 3-fluorophenol completely with approximately 100% fluoride anion release within 16 h. 3-Fluorophenol can serve as the sole carbon source and energy source for the organism. The acclimated activated sludge can degrade 3-fluorophenol effectively. The degradation mechanism study reveal that the initial step in the aerobic biodegradation of 3-fluorophenol is its transformation to fluorocatechol. Following transformation of the fluorophenol to fluorocatechol, ring cleavage by catechol 1, 2-dioxygenase proceedes via an ortho-cleavage pathway, then defluorination occurres.

[Studies on the electron transfer between etoposide (VP-16) and DNA].

In the present study, the electron transfer between Etoposide (VP-16) and GMP or DNA was investigated using pulse radiolysis and circular dichroism technology. The electron transfer between VP-16 and GMP was found, and the reaction rate constant was determined as 3.16 x 10(7) L x mol(-1) x s(-1) by pulse radiolysis. The authors found the interaction of VP-16 and DNA using the technology of circular dichroism. This study has provided theoretical reference for further study on the anti-tumor mechanism of VP-16.