A correlative study of iron metabolism based on q-Dixon MRI in benign prostatic hyperplasia and prostate cancer.

Clinical staging, Gleason score, and prostate-specific antigen (PSA) have been accepted as factors for evaluating the prognosis of prostate cancer (PCa). With the in-depth study of iron metabolism and the development of multiparametric magnetic resonance imaging technology, we used q-Dixon magnetic resonance imaging (MRI) to measure the iron content of the PCa patients' lesions, and used enzyme-linked immunosorbent assay (ELISA) to measure the iron metabolism indicators in the patients' serum samples, combined with the patients' postoperative clinical data for analysis. We found that the serum indexes were correlated with the T2 star values, International Society of Urological Pathology (ISUP) grade, and pathological classification in PCa patients (all P < 0.001) but not in benign prostatic hyperplasia (BPH) patients (all P > 0.05). The utilization of q-Dixon-based MRI and serum indexes allows the noninvasive measurement of iron content in prostate lesions and the assessment of differential iron metabolism between PCa and BPH, which may be helpful for evaluating the prognosis of PCa.

Thermo-sensitive polymer nanospheres as a smart plugging agent for shale gas drilling operations.

Emulsifier-free poly(methyl methacrylate-styrene) [P(MMA-St)] nanospheres with an average particle size of 100 nm were synthesized in an isopropyl alcohol-water medium by a solvothermal method. Then, through radical graft copolymerization of thermo-sensitive monomer N-isopropylacrylamide (NIPAm) and hydrophilic monomer acrylic acid (AA) onto the surface of P(MMA-St) nanospheres at 80 °C, a series of thermo-sensitive polymer nanospheres, named SD-SEAL with different lower critical solution temperatures (LCST), were prepared by adjusting the mole ratio of NIPAm to AA. The products were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, particle size distribution, and specific surface area analysis. The temperature-sensitive behavior was studied by light transmittance tests, while the sealing performance was investigated by pressure transmission tests with Lungmachi Formation shales. The experimental results showed that the synthesized nanoparticles are sensitive to temperature and had apparent LCST values which increased with an increase in hydrophilic monomer AA. When the temperature was higher than its LCST value, SD-SEAL played a dual role of physical plugging and chemical inhibition, slowed down pressure transmission, and reduced shale permeability remarkably. The plugged layer of shale was changed to being hydrophobic, which greatly improved the shale stability.