Fabrication and properties of temperature-responsive imprinted sensors based on fluorescently labeled yeast cells via MVL ATRP.

Temperature-responsive yeast cell-imprinted sensors (CIPs/AuNPs/Ti3C2Tx/AuNPs/Au) were prepared based on fluorescein isothiocyanate labeled yeast cells (FITC-yeast) via metal-free visible-light-induced atom transfer radical polymerization (MVL ATRP). Here, N-isopropyl acrylamide (NIPAM) was used as a temperature-responsive functional monomer, α-methacrylic acid (MAA) was chosen as an auxiliary functional monomer, N,N'-methylene bisacrylamide (MBA) was used as a cross-linker, and FITC-yeast was selected as both a template and photocatalyst. Under the optimal conditions, the detection range of the yeast cell-imprinted sensor toward yeast cells was 1.0 × 102 to 1.0 × 109 cells per mL, and the detection limit was 11 cells per mL (S/N = 3), with a linear equation of ΔI (µA) = 8.44 log[C (cells per mL)] + 7.62 (R2 = 0.993). The sensor showed good selective recognition in the presence of interfering substances such as autolyzed yeast cells (AY), dead yeast cells (DY), human mammary epithelial cells (MCF-10A), human breast cancer cells (MCF-7) and Escherichia coli (EC). The sensor also had good consistency and reproducibility. Finally, spiked recovery experiments were performed to investigate the recognition of yeast cells in the actual sample using the yeast cell-imprinted sensor. The spiked recoveries were all in the range of 98.5-108.0%, and the RSD values were all less than 4%, indicating that the sensor had good application prospects.

Ultramicro and ultrasensitive detection of lipopolysaccharides based on triple-signal amplification via ultrafast ATRP and an ultramicroelectrode.

Highly sensitive testing of trace lipopolysaccharides (LPS) is very important due to their high toxicity to the human body. Here, an ultrasensitive electrochemical sensor requiring only 5 µL solution was developed for LPS detection via triple-signal amplification based on ultrafast atom transfer radical polymerization (UATRP) and a Au ultramicroelectrode (UME). Firstly, the Au UME was modified with gold nanoparticles (nAu) and an LPS aptamer (Apt) in turn. When the Apt recognized LPS, the ATRP initiator of 4-(bromomethyl)phenylboronic acid (BPA) could be tethered to the electrode by covalent cross-linking between the phenylboronic acid moiety and the cis-diol site of LPS. Then UATRP was conducted for 2.5 min with nitrogen-doped carbon quantum dots (N-CQDs) as the photocatalyst and methylacrolein (MLA) as the monomer. After the electroactive probes of Ag nanoparticles (AgNPs) were formed on the surface of poly(MLA) by the silver mirror reaction, the electrochemical sensor was successfully prepared. Under the optimal conditions, the sensor exhibited a lower detection limit and a wider linear range when it was compared with a similar assay for LPS. In particular, the LOD of 7.99 × 10-2 pg mL-1 was better than that of the limulus amoebocyte lysate (LAL)-based technique, which is the gold standard for LPS detection. In the end, the sensor reported in this paper showed good selectivity and satisfactory feasibility for LPS detection in real biological samples and food products. The results obtained from the drug, blood and potable water samples laid a strong foundation for its clinical applications and application in other fields.

Molecular characterization and functional analysis of cyp11a and cyp11b in black rockfish (Sebastes schlegelii).

The cyp11 includes cyp11a and cyp11b in most mammals and teleosts, encoded cholesterol side chain lyase and 11ß-hydroxylase, respectively. It is essential in steroid hormone synthesis. However, studies on the regulation of cyp11 are limited, especially in teleosts. In this study, the molecular characterization and function of cyp11a and cyp11b of black rockfish was investigated. Both of them showed high homology with other teleost counterparts by phylogenetic analysis. The expression of cyp11a and cyp11b exhibited a clear sexually dimorphic pattern, with a higher expression level in testis than that of in ovaries. During the different developmental stages (40 dpf, 80 dpf, 190 dpf, 360 dpf, 720 dpf), the expression of cyp11a was earlier than cyp11b. In situ hybridization results showed that cyp11a and cyp11b were mainly expressed in oogonia and oocytes of the ovary. They were located in spermatogonia and interstitial compartment in the 1.5-year-old gonads, and spermatocytesgonia and the peritubular myoid cell of the testis in the 2.5-year-old gonads. To explore the distinct roles of cyp11a and cyp11b in gonads, oestrogen and androgens were used to stimulate the primary testicular and ovarian cells. The expressions of cyp11a and cyp11b were tested under different dose of 17α-methyltestosterone (17α-MT) and 17ß-estradiol (E2). The results showed cyp11a was significantly increased at 10-6  mol ml-1 of 17α-MT and 10-8  mol ml-1 of E2 in ovary and 10-10  mol ml-1 of 17α-MT and E2 in testis, while cyp11b was significantly decreased after 17α-MT and E2 treatment. These results indicated that cyp11a and cyp11b were likely to have different functions, and also implied they might play an important roles in the differentiation of gonads and the synthesis of steroids in black rockfish.

[Experimental studies of rhizoma Astilbes chinensis on its effects in abirritation, blood activation, cough relieving and sputum elimination].

OBJECTIVE: To study the effects of rhizoma Astilbes chinensis in abirritation, blood activation, cough relieving and sputum elimination. METHOD: The antalgic function of rhizoma A. chinensis was tested by hot-plate method and writhing reaction. The acute blood-stasis model rats were made by Injection of adrenaline hydrochloride along with stimulation by ice water. The effects of cough relieving and sputum elimination were observed by the ammonia water-induced tussive mice and excretion of phenol red in the airway of mice. The maximum tolerance dose of rhizoma A. chinensis was also determined during the acute toxicity test. RESULT: The data were analyzed for statistical significance by t-test, which shows that the decoction of rhizoma A. chinensis is significantly effective in reducing the frequency of licking behavior of mice on hot-plate and writhing response induced by acetic acid, improving the hemarheology of acute blood-stasis model rats, prolonging the latent period, reducing the frequency of cough induced byammonia, and in increasing the quantity of phenol red output from the trachea in mice. The result acute toxicity test shows that maximum tolerance dose of gastrogavage in mice was 400 g x kg(-1). Which was 666. 7 times of that clinically used for human. CONCLUSION: Rhizoma A. chinensis has the effects of abirritation, blood activation, cough relieving and sputum elimination, and is safe in clinical application.