Alignment technology based on a central small aperture for the AIMS telescope.

The accurate infrared solar magnetic field measurement system (AIMS) is a 1 m off-axis Gregorian alt-azimuth solar telescope and will be dedicated to measuring the solar magnetic field in mid-infrared. How to align the large-aperture off-axis system is a significant issue. Sub-aperture stitching with the small-aperture standard flat mirror can be applied to the alignment of the large-aperture off-axis system. However, this method is time-consuming and inefficient. We propose an alignment method based on the Zernike polynomials of the central small aperture to solve the low efficiency of sub-aperture stitching. Theoretical simulation shows that the RMS residual error of the system after using the central small-aperture alignment method will be less than 4.5∗10-6λ at 632.8 nm. Practical alignment suggests that our method can make the RMS value of full-aperture wave aberration quickly converge to 0.12λ at 632.8 nm. Compared with the sub-aperture stitching method, our method can significantly reduce the times of sub-aperture stitching and save the alignment time.

Highly sensitive determination of paracetamol, uric acid, dopamine, and catechol based on flexible plastic electrochemical sensors.

Flexible sensing is an alternative to traditional sensing and possesses good flexibility and wearability. Intrinsically conductive polymers, particularly poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS), have received significant attention due to their high mechanical flexibility and good biocompatibility. Here, we report the design of highly conductive and electrochemically active PEDOT:PSS-coated plastic substrate electrodes by combining N-doped graphene (NG) or S-doped graphene (SG) with methanesulfonic acid-treated PEDOT:PSS (denoted as NG-f-MSA-PEDOT:PSS/PET and SG-f-MSA-PEDOT:PSS/PET) by a simple drop-coating method. At room temperature, the NG-f-MSA-PEDOT:PSS/PET electrode demonstrated the lowest detection limits of 17.09, 33.84, 28.30, and 44.96 nM for paracetamol, uric acid, dopamine, and catechol (S/N = 3), respectively. The NG-f-MSA-PEDOT:PSS/PET electrode had good anti-interference ability and reproducibility without employing expensive noble metals and requiring much effort to polish the surface of traditional glass carbon electrodes. Most importantly, this film electrode could maintain a stable electrochemical response under different bending and crease states and had excellent mechanical stability and flexibility.

Electrochemically reduced phytic acid-doped TiO2 nanotubes for the efficient electrochemical degradation of toxic pollutants.

Element-doped TiO2 nanotube arrays (TNAs) with optimized active sites provide an effective approach for significantly improving electrocatalytic performance. The challenges in such construction mainly include selection of green dopant and control of active sites. Herein, we present phytic acid as a phosphorus source for P-doped TNAs. An oxygen vacancy (Ov) and P co-doped TNAs (P-TiO2-y) was prepared as an electrochemical oxidation anode. P-TiO2-y exhibits excellent degradation activity due to the formation of Ti-O-P bonds and generation of Ov. P-doping was beneficial in improving the oxygen evolution potential of the electrode, which would be benefit for electrocatalytic degradation of pollutants. Using the P-TiO2-y anode with a current density of 10 mA/cm2 for tetracycline degradation, after a 3 h treatment, the removal rate, chemical oxygen demand and total organic carbon removal rates were 100%, 90.32% and 76.60%, respectively. The P-TiO2-y also has excellent degradation performance for phenol, hydroquinone, p-nitrophenol and metronidazole.

Nanosilver and protonated carbon nitride co-coated carbon cloth fibers based non-enzymatic electrochemical sensor for determination of carcinogenic nitrite.

A novel electrochemical nitrite (NaNO2) sensor was fabricated by combining nanosilver with protonated carbon nitride (H-C3N4) supported on carbon cloth (CC). H-C3N4 was distributed uniformly on the CC surface, providing more active sites for the electrocatalytic active center (nanosilver). CC as a substrate improved the H-C3N4 conductivity and provided the sensor with a flexible feature. The strong synergistic effect between CC, H-C3N4, and nanosilver can exert a significant electrocatalytic performance on the flexible sensor. The Ag/H-C3N4/CC flexible sensor electrode did not consume much more time to polish the surface of traditional electrodes, and possessed a high sensitivity of 0.85537 µA/mg, a wide linear response range that spanned 5 to 1000 µM, a low detection limit of 0.216 µM (S/N = 3), and high selectivity for nitrite in the presence of common organic and inorganic interfering species (such as CaCl2, NaCl, MgCl2, NaNO3, glucose, urea, and p-nitrophenol). The Ag/H-C3N4/CC flexible sensor can be used for sample detection of nitrite as it has a strong anti-interference ability, good reproducibility, repeatability, and long-term stability. The Ag/H-C3N4/CC sensor is a promising alternative electrode to traditional ones such as ITO, gold or glassy carbon electrodes.

Preparation of an AgI/CuBi2O4 heterojunction on a fluorine-doped tin oxide electrode for cathodic photoelectrochemical assays: application to the detection of L-cysteine.

Photocathodic methods in photoelectrochemical (PEC) analysis are based on the use of functional photocathodes. Heterojunction cathodes consisting of different kinds of semiconductors are being considered as favorite schemes when compared to the single-component ones. A semiconductor heterojunction between CuBi2O4 (CBO) and other semiconductors has not been exploited in PEC assays so far. Herein, CBO nanospheres were initially electrochemically deposited on a fluorine-doped tin oxide (FTO) conductive glass and then coupled to chemically deposited AgI nanoparticles to obtain an electrode of type AgI/CBO/FTO. It was applied as a cathode in the PEC detection of L-cysteine as a model analyte. The sensor can selectively detect L-cysteine, and it is assumed that this is due to the selective interaction between the L-cysteine and both copper and silver via the formation of Cu-S and Ag-S bonds. The photocurrent of the electrode increases linearly with the logarithm of the cysteine concentration in the range from 0.1 and 50 µM, and the detection limit is 0.1 µM. Graphical abstract Schematic presentation of the preparation of an AgI/CuBi2O4 (AgI/CBO) heterojunction on a fluorine-doped tin oxide (FTO) electrode and its application to the cathodic photoelectrochemical detection of L-cysteine.

Effect of maternal and embryonic factors on frozen-thawed IVF-ET outcome after pre-equilibration with hyaluronan.

PURPOSE: To systematically evaluate the effect of maternal and embryonic factors on in vitro fertilization and embryo transfer (IVF-ET) outcomes among Chinese patients after using hyaluronan-enriched transfer medium (HETM). METHODS: This retrospective study included 637 frozen-thawed ET cycles. Patients were divided into subgroups based on their maternal or embryonic status or treatment procedures. The implantation, clinical pregnancy, delivery, and abortion rates were compared between the HETM and control groups. In addition, the implantation and clinical pregnancy rates were used to analyze the reciprocal effect of HETM and Preimplantation genetic screening (PGS) assessment. RESULTS: Maternal risk factors, especially maternal aging and a low number of retrieved oocytes, have a significant adverse impact on the efficacy of HETM usage. Endometrial preparation with artificial and natural cycles but not stimulated cycles showed a satisfying outcome after IVF-ET treatment. Compared with cleavage embryos, blastocyst stage embryo transfer showed more prominent improvement when using HETM. Prolonged pre-equilibration treatment with HETM notably compromised the IVF-ET outcome. PGS-based preselection could further facilitate the HETM-induced beneficial effect on IVF-ET outcomes. The body weight, length, and sex ratio of the neonate did not significantly differ between the HETM and control groups. CONCLUSION: Both the maternal and embryonic status or treatment procedures affected the IVF-ET outcomes after using HETM. HETM had a beneficial effect on advantaged IVF cycles but did not improve the outcomes of disadvantaged IVF cycles. Endometrial preparation with stimulated cycles is not recommended when using HETM. Prolonged pre-equilibration treatment must be avoided.

[Sperm DNA damage and unexplained recurrent spontaneous abortion].

OBJECTIVE: To explore the relationship of sperm DNA damage with unexplained recurrent spontaneous abortion (URSA). METHODS: Sperm DNA fragmentation was evaluated by sperm chromatin dispersion (SCD), and the results were expressed in terms of DNA fragmentation index (DFI). DFIs were measured in the male partners of 56 women with URSA (the experiment group) and of 31 without URSA (the control group). RESULTS: The DFI was shown to be (11.0% - 56.9%) in the experiment group, 21 (37.5%) of the subjects over 30%, as compared with (10.0% -36.8%) in the control group, only 8 (25.8%) of the subjects over 30%, significantly higher in the former than in the latter (29.4% vs 25.5%, P < 0.05). CONCLUSION: There is a relationship between sperm DNA damage and URSA.

[Effect of adenosine on electrophysiological changes of ventricular myocardium in rats with experimental diabetes].

OBJECTIVE: To investigate the electrophysiological changes of ventricular myocardium of rats with experimental diabetes and the effect of adenosine on its electrophysiology. METHODS: Diabetes was induced in male SD rats, using a single injection of alloxan into tail vein. Untreated animals were used as controls. The electrocardiograms (ECG) were recorded 6 weeks after diabetes was induced. Effects of adenosine on ventricular myocardium in diabetic rats and controls were observed by measuring the transmembrane potentials with conventional glass microelectrodes. RESULTS: QT interval in ECG and action potential duration (APD) at all levels (APD30, APD50, APD70 and APD90) were significantly prolonged in right ventricular papillary muscle 6 week after diabetes was induced. No differences were observed in the resting membrane potential (RP), action potential amplitude (APA) and overshoot (OS) as well as the maximum rate of depolarization (Vmax) between the diabetic rats and control rats. At concentration of 10 approximately 400 micromol/L, ADO had little influence on all transmembrane potential parameters of right ventricular papillary muscle in diabetic rats and controls. At 500 micromol/L, ADO shortened APD30, APD50, APD70 and APD90 of control group, while having no effect on diabetic rats. CONCLUSION: QT interval in ECG and APD at all levels are significantly prolonged in right ventricular papillary muscle of experimentally induced-diabetic rats.