In situ fast self-assembled preparation of dandelion-like Cu(OH)2@Cu3(HHTP)2 with core-shell heterostructure arrays for electrochemical sensing of formaldehyde in food samples.

Formaldehyde is known to harm the respiratory, nervous, and digestive systems of people. In this paper, a novel dandelion-like electrocatalyst with core-shell heterostructure arrays were fast self-assembled prepared in situ using copper foam (CF) as support substrate and 2,3,6,7,10,11 hexahydroxy-triphenyl (HHTP) as ligand (Cu(OH)2@Cu3(HHTP)2/CF) by a simple two-step hydrothermal reaction. The 1D Cu(OH)2 nanorods "core" and the 2D π-conjugated conducting metal-organic frameworks (Cu3(HHTP)2cMOF) "shell" with remote delocalized electrons give the dandelion-like heterogeneous catalysts excellent electrochemical activity such as a large specific surface area, high conductivity and a fast electron transfer rate. The Cu(OH)2@Cu3(HHTP)2/CF exhibited excellent electrocatalytic performance for formaldehyde under alkaline conditions with a linear range of 0.2 µmol/L - 125 µmol/L and 125 µmol/L - 8 mmol/L, a detection limit as low as 15.9 nmol/L (S/N = 3), as well as good accuracy, consistency, and durability, and it effectively identified FA in food.

NiCo-LDH coupled with 2D ZIF-derived Co nitrogen doped carbon nanosheet arrays as a self-supporting electrocatalyst for detection of formaldehyde.

Formaldehyde is susceptible to illegal addition to foodstuffs to extend their shelf life due to its antimicrobial, preservative and bleaching properties. In this study, a self-supporting "nanosheet on nanosheet" arrays electrocatalyst with core-shell heterostructure was prepared in situ by coupling NiCo layer double hydroxide with 2D ZIF derived Co-nitrogen-doped porous carbon on carbon cloth (Co-N/C@NiCo-LDH NSAs/CC). Co-N/C nanosheet arrays act as a scaffold core with good electrical conductivity, providing more NiCo-LDH nucleation sites to avoid NiCo-LDH agglomeration, thus having fast mass/charge transfer performance. While the NiCo-LDH nanosheet arrays shell with high specific surface area provide more active sites for electrochemical reactions. As an electrocatalytic sensing electrode, Co-N/C@NiCo-LDH NSAs/CC has a wide linear range of 1 µM to 13 mM for formaldehyde detection, and the detection limit is 82 nM. Besides, the sensor has been applied to the detection of formaldehyde in food samples with satisfactory results.

Construction of Co-ZIF-derived CoS2@Cu hollow heterogeneous nanotube array for the detection of hydrazine in environmental water samples.

As a neurotoxin, it is necessary to establish a low cost, stable and sensitive method for the quantitative detection of hydrazine. Using Co-ZIF (zeolite imidazole framework) nanorods as precursor, CoS2 hollow nanotube array heterogeneous structure loaded with Cu nanoparticles were prepared on carbon cloth (CC) by etching, calcination and plasma magnetron sputtering (CoS2@Cu HNTA/CC). As a self-supporting electrode, its hollow heterogeneous structure provides a large area of electron transfer channel for the oxidation of the food pollutant hydrazine. In addition, bimetallic synergies and in situ N doping regulated the electronic structure of CoS2@Cu HNTA/CC, and thus significantly improved the electrical conductivity and catalytic activity. As an efficient hydrazine sensor with a wide linear range of 1 µM L-1-10 mM (1 µM-1 mM and 1 mM-10 mM), its sensitivity and the limit of detection are 7996 µA mM-1 cm-2, 3772 µA mM-1 cm-2 and 0.276 µM (S/N = 3), respectively. This study provides a new strategy for the construction of MOFs (Metal Organic Framework)-derived bimetallic composites and their application in electrochemical sensing.

Effect of nalbuphine plus ropivacaine on vaginal labor in epidural analgesia.

BACKGROUND: Various approaches using epidural analgesia have been employed for relieving labor pain and promoting spontaneous delivery. We aimed to evaluate the effect of nalbuphine and ropivacaine versus fentanyl and ropivacaine on the duration of delivery in parturients. METHODS: Clinical data of 160 full-term primiparous women who received either nalbuphine or fentanyl in combination with ropivacaine infusion for epidural labor analgesia in our hospital from December 2020 to May 2022 were retrospectively analyzed. The participants were divided into two groups based on anesthesia methods: nalbuphine group (NR group, n = 78) received 0.2 mg/mL nalbuphine combined with 0.1% ropivacaine hydrochloride for patient-controlled epidural analgesia (PCEA) and fentanyl group (FR group, n = 82) received 2 ug/mL fentanyl citrate and 0.1% ropivacaine hydrochloride for PCEA. Both groups received an epidural blockade for labor analgesia at lumbar 2-3 interspace. The duration of the first, second, and third stages of labor, the onset of analgesia, and time before delivery (T0), 15 min of analgesia (T1), 30 min of analgesia (T2), full opening of the uterine opening (T3),exerts force during childbirth(T4), heart rate (HR), blood pressure (BP), blood saturation (SpO2), visual analogue pain scale (VAS) score, Ramsay sedation score, and modified Bromage score, and 5 min were recorded at 2 h postpartum (T5). The neonatal Apgar score, neonatal behavioral neurological assessment (NBNA) score, maternal nausea, vomiting, and itchy skin were recorded. RESULTS: Compared with the FR group, the first stage of labor duration (p < 0.05) and total duration of labor (p < 0.05) were shortened and the onset of analgesia (p < 0.05) was increased in the NR group. NR group had lower incidence of urinary retention than FR group (p < 0.05). The maternal and neonatal investigational parameters and scores had no significant difference between the two groups. CONCLUSIONS: Nalbuphine combined with ropivacaine in epidural block labor has a faster onset of analgesia and has a lower incidence of urinary retention than fentanyl combined with ropivacaine, and nalbuphine shortens the duration of the first and total stages of labor. Both nalbuphine and fentanyl can reduce pain during labor, have little effect on maternal hemodynamics, and have no significant effect on neonatal Apgar or NBNA scores.

Electromagnetic induction detector for capillary electrophoresis and its application in pharmaceutical analysis.

A new electromagnetic induction detector for capillary electrophoresis and its application are described. The detector is consisted of an inductor, a resistor, a high-frequency signal generator and a high-frequency millivoltmeter. The conditions affecting the response of the detector, including dimension of the magnetic ring, position of the capillary, number of coil turns, frequency, excitation voltage and value of the resistor were examined and optimized. The feasibility of the proposed detector was evaluated by detection of inorganic ions and separation of amino aids. Its quantification applicability was investigated by determination of aspirin and paracetamol in pharmaceutical preparation (Akafen powder). The primary factors affecting separation efficiency, which include variety of buffer, buffer concentration, injection time and injection height and separation voltage, were researched. Experimental results demonstrated that this new detector showed a well-defined correlation between sample concentrations and responses (r=0.997-0.999), with detection limits of 30 µmol L(-1) for aspirin and 10 µmol L(-1) for paracetamol, as well as good reproducibility and stability. Compared with currently available detection techniques, this new detector has several advantages, such as simple construction, no complicated elements, ease of assembly and operation, and potential for universal applications. It can be an alternative to the traditional methods in the quality control of the pharmaceutical preparations.

Dual fluorescence/contactless conductivity detection for microfluidic chip.

A new dual detection system for microchip is reported. Both fluorescence detector (FD) and contactless conductivity detector (CCD) were combined together and integrated on a microfluidic chip. They shared a common detection position and responded simultaneously. A blue light-emitting diode was used as excitation source and a small planar photodiode was used to collect the emitted fluorescence in fluorescence detection, which made the device more compact and portable. The coupling of the fluorescence and contactless conductivity modes at the same position of a single separation channel enhanced the detection characterization of sample and offered simultaneous detection information of both fluorescent and charged specimen. The detection conditions of the system were optimized. K(+), Na(+), fluorescein sodium, fluorescein isothiocyanate (FITC) and FITC-labeled amino acids were used to evaluate the performance of the dual detection system. The limits of detection (LOD) of FD for fluorescein Na(+), FITC, FITC-labeled arginine (Arg), glycine (Gly) and phenylalanine (Phe) were 0.02micromolL(-1), 0.05micromolL(-1), 0.16micromolL(-1), 0.15micromolL(-1), 0.12micromolL(-1) respectively, and the limits of detection (LOD) of CCD achieved 0.58micromolL(-1) and 0.39micromolL(-1) for K(+) and Na(+) respectively.

NB-3/Notch1 pathway via Deltex1 promotes neural progenitor cell differentiation into oligodendrocytes.

Neurons and glia in the vertebrate central nervous system arise in temporally distinct, albeit overlapping, phases. Neurons are generated first followed by astrocytes and oligodendrocytes from common progenitor cells. Increasing evidence indicates that axon-derived signals spatiotemporally modulate oligodendrocyte maturation and myelin formation. Our previous observations demonstrate that F3/contactin is a functional ligand of Notch during oligodendrocyte maturation, revealing the existence of another group of Notch ligands. Here, we establish that NB-3, a member of the F3/contactin family, acts as a novel Notch ligand to participate in oligodendrocyte generation. NB-3 triggers nuclear translocation of the Notch intracellular domain and promotes oligodendrogliogenesis from progenitor cells and differentiation of oligodendrocyte precursor cells via Deltex1. In primary oligodendrocytes, NB-3 increases myelin-associated glycoprotein transcripts. Thus, the NB-3/Notch signaling pathway may prove to be a molecular handle to treat demyelinating diseases.