Flow-mediated dilatation to relieve puncture-induced radial artery spasm: A pilot study

  Background: Puncture-induced radial artery spasm (RAS) may extend the duration of coronary an­giography (CAG) or cause transradial access failure. Flow-mediated dilatation (FMD), a widely-used noninvasive approach for assessing endothelial function, was reported to remove the entrapped radial sheath after percutaneous coronary intervention. Herein, the efficacy and safety of FMD in treating puncture-induced RAS before transradial CAG was investigated. Methods: Ninety patients with puncture-induced RAS were randomized in a 1:1:1 ratio into three groups: FMD group was immediately treated with blockage of brachial artery blood for 5 min using a sphygmomanometric cuff and then rapid relief; nitroglycerin (NTG) group was administered with 0.5 mg sublingual NTG instantly; and the no-therapy group was treated with a wait-and-watch strategy. The time of radial pulse recovery, and regional and systemic complications were recorded. Results: The rate of radial pulse recovery within 30 min in FMD group was significantly higher than that in no-therapy group (97% vs. 73%, p = 0.026). The median time to return of radial pulse in FMD group and NTG group was significantly shorter than that in no-therapy group (7 [6.5–9] min vs. 15 [12–18] min, 8 [7–9] min vs. 15 [12–18] min, respectively; both p < 0.001). Headache and decreased blood pressure were more prevalent in NTG group than those in FMD and no-therapy groups. Conclusions: FMD is a feasible, noninvasive and nonpharmacological approach to relieve RAS and facilitate radial artery cannulation after an initial failed attempt. (Cardiol J 2018; 25, 1: 1–6

Application of Ionic Liquids in the Microwave-Assisted Extraction of Proanthocyanidins from Larix gmelini Bark

Ionic liquid based, microwave-assisted extraction (ILMAE) was successfully applied to the extraction of proanthocyanidins from Larix gmelini bark. In this work, in order to evaluate the performance of ionic liquids in the microwave-assisted extraction process, a series of 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were evaluated for extraction yield, and 1-butyl-3-methylimidazolium bromide was selected as the optimal solvent. In addition, the ILMAE procedure for the proanthocyanidins was optimized and compared with other conventional extraction techniques. Under the optimized conditions, satisfactory extraction yield of the proanthocyanidins was obtained. Relative to other methods, the proposed approach provided higher extraction yield and lower energy consumption. The Larix gmelini bark samples before and after extraction were analyzed by Thermal gravimetric analysis, Fourier-transform infrared spectroscopy and characterized by scanning electron microscopy. The results showed that the ILMAE method is a simple and efficient technique for sample preparation

Compared the efficacy of mitoxantrone hydrochloride injection for tracing with radionuclide in sentinel lymph node biopsy of breast cancer

Background and purpose: Both domestic and foreign guidelines recommend the use of radionuclide as sentinel lymph node (SLN) biopsy (SLNB) tracer, however this technique has not been popularized in China for a variety of reasons. Mitoxantrone hydrochloride injection for tracing (MHI), a new strategy to identify lymph nodes, has not been tested for axillary node staging in breast cancer. This multicenter, self-controlled, non-inferiority trial aimed to evaluate the differences between MHI and radionuclide in SLNB tracing. Methods: The trial was conducted across 7 hospitals from December 2019 to December 2020. Patients with early-stage breast cancer received MHI and radionuclide (technetium 99 labeled sulfur colloid, 99mTc-Sc) as SLN tracers during the surgery. The number of SLNs detected and sentinel node detection rates of MHI and radionuclide were counted to evaluate differences in the tracing effects between the two tracers. Results: SLN detection rates of MHI and radionuclide were 96.9% (370/382) and 97.4% (372/382), respectively, with no significant difference (P>0.05). SLNs were co-detected by both tracers in 362 (94.7%) patients; 16 (4.1%) had adverse events possibly related to the trial drugs. Conclusion: In this study, it was found that the lymphatic tracing ability of MHI was not inferior to that of radionuclide. Meanwhile, the use of MHI does not require special instrument/equipment assistance

Temporal and Spatial Profiling of Root Growth Revealed Novel Response of Maize Roots under Various Nitrogen Supplies in the Field

A challenge for Chinese agriculture is to limit the overapplication of nitrogen (N) without reducing grain yield. Roots take up N and participate in N assimilation, facilitating dry matter accumulation in grains. However, little is known about how the root system in soil profile responds to various N supplies. In the present study, N uptake, temporal and spatial distributions of maize roots, and soil mineral N (Nmin) were thoroughly studied under field conditions in three consecutive years. The results showed that in spite of transient stimulation of growth of early initiated nodal roots, N deficiency completely suppressed growth of the later-initiated nodal roots and accelerated root death, causing an early decrease in the total root length at the rapid vegetative growth stage of maize plants. Early N excess, deficiency, or delayed N topdressing reduced plant N content, resulting in a significant decrease in dry matter accumulation and grain yield. Notably, N overapplication led to N leaching that stimulated root growth in the 40–50 cm soil layer. It was concluded that the temporal and spatial growth patterns of maize roots were controlled by shoot growth and local soil Nmin, respectively. Improving N management involves not only controlling the total amount of chemical N fertilizer applied, but also synchronizing crop N demand and soil N supply by split N applications

Synthesis of the kempane diterpene ring system, and regio- and stereoselectivity in the reductions of cyclic enediones

Kempane diterpenes such as 1 and 2, which are a class of compact tetracyclic compounds isolated from the defense secretions of nasute soldier termites, have been challenging synthetic targets. We have achieved a highly stereoselective synthesis of the kempane diterpene ring system that possesses all the required stereogenic centers and sufficient functionality to allow elaboration to 1 and 2. A key step of our synthesis of the ring system is the highly regia- and facially-selective Diels-Alder cycloaddition of cis-5-(I-((tert-butyldimethylsilyl)oxy)vinyl)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one (78) and 2,6-dimethyl-1,4-benzoquinone (13) to establish the benzoindane ring system 79. The diene 78 was prepared through a sequence that contained a regiospecific [2 + 2] cycloaddition of 1-methyl-1 ,3-cyclohexadiene (38) with dichloroketene, generated in situ from dichloroacetyl chloride and triethylamine. Though attempts to cyclize the seven-membered ring in hemi-acetal 72 by aldol reaction were unsuccessful due to the difficulty in opening the five-membered hemi-acetal ring, the seven-membered ring was constructed by a regiospecific Dieckmann condensation in ethyl (1α,2β,4α,4aβ,6β,6aα,7aβ,10aβ,10bα,10cα)-2,3,4,4a,5,6,6a,7,7a,10,10a,10b,10c-tridecahydro-4-hydroxy-6-(2-methoxyethoxy)methoxy-2,10c-dimethyl-9-oxo-1Hbenz[6,7]indeno-[2,1-b]furan-l-methylcarboxylate (131). The transformation of the benzoindane ring system 79 to carboxylate 131 involved a remarkably regio- and stereoselective addition of an acetylide to the apparently more hindered carbonyl in 79, a reductive cleavage of a γ-hydroxy group in an α,β-enone system, and a one-pot acid-promoted epimerization and double-bond isomerization. -- To explore the possibility of modifying our synthesis of the kempane diterpene ring system to an asymmetric approach, we investigated the asymmetric [2 + 2] cycloadditions of enantiopure, L-menthoxy- and 1,2:5 ,6-di-O-isopropyllidene-a-D-glucofuranoxy-substituted ketenes 174 and 185 with cyclopentadiene (175). -- In the course of the synthetic study towards kempane diterpenes, an exiremely regia- and stereoselective reduction of the seemingly more hindered carbonyl in enedione 56 with lithium tri-tert-butoxyaluminohydride or sodium borohydride was observed. Systematic study proved this observation to be general with non-bridged cyclic enediones. Both the regio- and stereoselectivities are due to a preference for axial attack by the reducing reagents. Among possible axial additions to the two carbonyls, only one approach is sterically allowed. It was also found that the combination of sodium borohydride and cerium trichloride, the Luche reagent, was a useful alternative reducing reagent. It either improved or completely reversed the regioselectivity

Matrix Extraction of Parasitic Parameters and Suppression of Common-Mode Conducted Interference in a PMSG-IDOS Rectifier Module

The rectifier module is the key part of a permanent magnet synchronous generator integrated DC output system (PMSG-IDOS) with low-voltage and high-current. The high-speed switching device of the rectifier module is the main source of electromagnetic interference (EMI). In this paper, the matrix extraction method is proposed to establish an accurate conducted interference model, and a 3D crimped SiC MOSFET model is established via Ansoft Q3D simulation software. The matrix of the parasitic parameters between poles of the MOSFET is simulated to extract the accurate parasitic parameters. Furthermore, a high-precision conducted interference simulation model of the pulse width modulation (PWM) rectifier system is established. Then, the space vector pulse width modulation (SVPWM) jump-backward control strategy based on the three-phase four-leg structure is proposed to suppress the common-mode interference, and the comparison with other two methods is carried out based on this model. Finally, the experimental platform of a 5 V/1000 A synchronous generator with rectifier is constructed, and conducted interference is tested in accordance with the simulated results. It demonstrates the accuracy of the model with parasitic parameters based on the matrix extraction method. This paper provides a more simple and effective reference method for the prediction study of conducted interference in power converter systems. After comparing the simulation results with the experimental results, it is proven that the SVPWM jump-backward control strategy based on the three-phase four-leg structure can ensure the output balance of the bridge leg and allow the common-mode (CM) interference to reach the ideal state