Electroenzymatic tandem catalysis for the conversion of nitrate into ammonia.

A porous silver nanostructure-supported ionic liquid-modified chloroperoxidase nanohybrid was successfully used in electroenzymatic tandem catalysis to achieve an efficient, mild, and stable approach for the conversion of nitrate into ammonia.

A dendritic porous copper foam-carbonic anhydrase biohybrid for carbon dioxide electroreduction.

Carbonic anhydrase (CA) is bound to a dendritic porous copper foam (3D-Cu) via electrostatic interaction to form a biohybrid (CA/3D-Cu), which exhibits high selectivity and Faraday efficiency in the electroreduction of carbon dioxide (CO2) to formic acid (selectivity of 98.7%, Faraday efficiency of 82.1%) due to the large specific surface area of the 3D-Cu and the ultra-high CO2 hydration capacity of CA.

Electroenzymatic cascade reaction on a biohybrid boosts the chiral epoxidation reaction.

The chiral epoxidation of styrene and its derivatives is an important transformation that has attracted considerable scientific interest in the chemical industry. Herein, we integrate enzymatic catalysis and electrocatalysis to propose a new route for the chiral epoxidation of styrene and its derivatives. Chloroperoxidase (CPO) functionalized with 1-ethyl-3-methylimidazolium bromide (ILEMB) was loaded onto cobalt nitrogen-doped carbon nanotubes (CoN@CNT) to form a biohybrid (CPO-ILEMB/CoN@CNT). H2O2 species were generated in situ through a two-electron oxygen reduction reaction (2e-ORR) at CoN@CNT to initiate the following enzymatic epoxidation of styrene by CPO. CoN@CNT had high electroactivity for the ORR to produce H2O2 at a more positive potential, prohibiting the conversion of FeIII to FeII in the heme of CPO to maintain enzymatic activity. Meanwhile, CoN@CNT could serve as an ideal carrier for the immobilization of CPO-ILEMB. Hence, the coimmobilization of CPO-ILEMB and CoN@CNT could facilitate the diffusion of intermediate H2O2, which achieved 17 times higher efficiency than the equivalent amounts of free CPO-ILEMB in bulk solution for styrene epoxidation. Notably, an enhancement (∼45%) of chiral selectivity for the epoxidation of styrene was achieved.

Analysis of Characteristics in the Macro-Composition and Volatile Compounds of Understory Xiaobai White Tea.

Understory planting affects the growth environment of tea plants, regulating the tea plant growth and the formation of secondary metabolites, which in turn affects the flavor of Xiaobai white tea. The present research adopted biochemical composition determination, widely targeted volatilities (WTV) analysis, multivariate statistical analysis, and odor activity value (OAV) analysis to analyze the characteristics in the macro-composition and volatile compounds of understory white tea. The sensory evaluation results indicated that understory Xiaobai white tea (LWTs) was stronger than ordinary Xiaobai white tea (PWTs) in terms of the taste of smoothness, sweetness, and thickness as well as the aromas of the flower and sweet. Understory planting reduced light intensity and air temperature, increased air humidity, organic matter, total nitrogen, and available nitrogen contents, which improved the growth environment of tea plants. The phytochemical analysis showed that the water-extractable substances, caffeine, flavonoids, and soluble sugar contents of understory tea fresh-leaf (LF) were higher than those of ordinary fresh-leaf (PF). The phytochemical analysis showed that the free amino acids, theaflavins, thearubigins, water-extractable substances, and tea polyphenols contents of LWTs were significantly higher than those of PWTs, which may explain the higher smoothness, sweetness, and thickness scores of LWTs than those of PWTs. The 2-heptanol, 2-decane, damasone, and cedar alcohol contents were significantly higher in LWTs than in PWTs, which may result in stronger flowery and sweet aromas in LWTs than in PWTs. These results provide a firm experimental basis for the observed differences in the flavor of LWTs and PWTs.

Comparative retrospective review of perioperative analgesia using ultrasound-guided programmed intermittent erector spinae plane block for video-assisted thoracoscopic lobectomy.

BACKGROUND: The retrospective cohort study was conducted to estimate the opioid-sparing anesthesia and limited side-effects with ultrasound (US)-guided ESPB using programmed intermittent bolus (PIB) or continuous infusion (CI) and standard opioid-based anesthesia in patients undergoing video-assisted thoracoscopic lobectomy (VATS). METHODS: Patients underwent VATS were stratified into either control group or one of the two ESPB groups in a 1:2:2 ratio depending on whether PIB was implemented or not. The primary endpoint was intra- and post-operative opioids consumption over the first 48 h following surgery. RESULTS: A total of 180 cases were included in the analysis. Cumulative perioperative opioid administration was found to be significantly different between PIB, CI and control group (both p < 0.001), and between PIB and CI group (p = 0.028). More specifically, the mean was 305.30 ± 51.35 mg, 339.68 ± 56.07 mg and 468.91 ± 79.84 mg in PIB, CI and control group. NRS scores at rest across all postoperative times were comparable in two ESPB groups, while significantly lower than control group, however, scores during exercising at postoperative 3, 6, 12 h were significantly lower in PIB group as compared to CI group. A wider anesthetized dermatomes with PIB was observed at 6, 24 and 48 h as opposed to the CI. The mean of levobupivacaine plasma concentration was significantly lower for PIB at postoperative 0.5, 12, 24 and 48 h after initiation than CI. However, local anesthetic toxicity was not observed in any of the two ESPB groups. CONCLUSIONS: When US-guided ESPB using PIB was performed preoperatively, it contributed to the minimization of intra- and post-operative opioid consumption due to better analgesia with a wider anesthetic dermatome opposed to conventional CI, whereas, it was also associated with lower risk of local anesthetic toxicity because of lower plasma concentration of levobupivacaine.

The chloroperoxidase immobilized on porous carbon nanobowls for the detection of trichloroacetic acid by electroenzymatic synergistic catalysis.

Trichloroacetic acid (TCA), as a by-product of chlorination disinfection, is a highly carcinogenic chemical. Due to the widespread use of chlorination disinfection, it is critical to detect TCA in drinking water to decrease the incidence of disease. In this work, we developed an efficient TCA biosensor via electroenzymatic synergistic catalysis. The porous carbon nanobowls (PCNB) are prepared and wrapped by an amyloid like proteins formed by phase-transitioned lysozyme (PTL-PCNB), then, chloroperoxidase (CPO) is abounding to PTL-PCNB owing to its strong adhesion. The ionic liquid of 1-ethyl-3-methylimidazolium bromide (ILEMB) is co-immobilized on PTL-PCNB to from CPO-ILEMB@PTL-PCNB nanocomposite to assist the direct electron transfer (DET) of CPO. The PCNB plays two roles here. In addition, to increasing the conductivity, it serves as an ideal support for holding CPO; The CPO-ILEMB@PTL-PCNB nanocomposite modified electrode presents high efficiency for sensing TCA. Through electroenzymatic synergistic catalysis, a wide detection range of 33 µmol L-1 to 98 mmol L-1 can be achieved with a low detection limit of 5.9 µmol L-1, and high stability, selectivity as well as reproducibility, which ensures its potential practical applicability. This work provides a new platform for the electro-enzyme synergistic catalysis in one pot.

Synergistic catalysis and detection of hydrogen peroxide based on a 3D-dimensional molybdenum disulfide interspersed carbon nanotubes nanonetwork immobilized chloroperoxidase biosensor.

Enzyme-based electrochemical biosensors are promising for a wide range of applications due to their unique specificity and high sensitivity. In this work, we present a novel enzyme bioelectrode for the sensing of hydrogen peroxide (H2O2). The molybdenum disulfide nanoflowers (MoS2) is self-assembled on carboxylated carbon nanotubes (CNT) to form a three-dimensional conductive network (3D-CNT@MoS2), which is modified with 1-ethyl-3-methylimidazolium bromide (ILEMB), and followed by anchoring chloroperoxidase (CPO) onto the nanocomposite (3D-CNT@MoS2/ILEMB) through covalent binding to form a bioconjugate (3D-CNT@MoS2/ILEMB/CPO). The ILEMB modified 3D-CNT@MoS2/ILEMB has good hydrophilicity and conductivity, which not only provides a suitable microenvironment for the immobilization of CPO but also facilitates the direct electron transfer (DET) of CPO at the electrode. The 3D-CNT@MoS2/ILEMB/CPO bioconjugate modified electrode has a high catalytic efficiency for H2O2. Through electroenzymatic synergistic catalysis for H2O2 detection by 3D-CNT@MoS2/ILEMB/CPO-GCE, a wide detection range of 0.2 µmol·L-1 to 997 µmol·L-1 and a low detection limit of 0.097 µmolï½¥L-1 with high sensitivity of 1050 µA·mmol·L-1·cm-2 were achieved. Additionally, the 3D-CNT@MoS2/ILEMB/CPO-GCE displayed exceptional stability, selectivity, and reproducibility. Furthermore, 3D-CNT@MoS2/ILEMB/CPO-GCE is suitable for sensing of H2O2 in human urine s with good recovery, suggesting its potential application for the detection of H2O2 in biomedical field.

Application and clinical significance of tissue ultrasound for assessment of right ventricular diastolic function in patients with coronary slow flow.

Objectives: To evaluate right ventricular diastolic function in patients with coronary slow flow phenomenon (CSFP) by using Doppler tissue imaging (DTI). Methods: CSFP patients diagnosed using coronary angiography from June 2019 to December 2020 at the third Hospital of Quzhou were retrospectively investigated, with a similar number of patients with normal coronary blood flow during the same period taken as the control group. Right ventricular systolic and diastolic function index was measured via DTI. Results: No differences were found between CSFP and control groups in terms of baseline data, RV end systolic diameter, RV end diastolic diameter, or RV ejection fraction. The peak velocity E in the early diastolic phase of the right ventricle was decreased in CSFP patients, while the peak velocity a in the late diastolic phase of the right ventricle was increased, resulting in a lower E / a ratio. Conclusions: Right ventricular diastolic function in patients with CSFP is decreased, and this can be identified using DTI. DTI has important applicative value for evaluating right ventricular diastolic function in patients with CSFP.

Intermittent tube feeding for stroke patients with dysphagia: a meta-analysis and systematic review.

BACKGROUND: Nutrition supports is essential to the prognosis of stroke patients with dysphagia. It's necessary to evaluate the effects and safety of intermittent tube feeding for stroke patients with dysphagia, to provide evidence for the management of dysphagia. METHODS: Cochrane Library et al. databases were searched for randomized controlled trials (RCTs) on the intermittent tube feeding for stroke patients with dysphagia up to Feb 15, 2021. Bias risk assessment tool recommended by Cochrane was used for quality assessment, and Revman5.3 software was used for data analysis. RESULTS: A total of 11 RCTs involving 762 stroke patients with dysphagia were included. Meta-analysis indicated that intermittent tube feeding could significantly increase the rate of dysphagia function improvement [odd ratio (OR ) = 5.22, 95% confidence interval (CI): 3.38-8.07], serum albumin level [mean difference (MD) = 3.07, 95% CI: 1.65-4.49], hemoglobin level (MD =1.55, 95% CI: 1.19-1.95), prealbumin level (MD =1.79, 95% CI: 1.46-2.12), and reduce the incidence of aspiration pneumonia (OR = 0.28, 95% CI: 0.15-0.53), incidence of aspiration (OR =0.27, 95% CI: 0.08-0.93) for stroke patients with dysphagia (all P<0.05), o significant difference in the triceps skinfold thickness (TSF) (MD =0.46, 95% CI: -0.24 to 1.19) and arm muscle circumference (MD =0.04, 95% CI: -0.28 to 0.36) between two groups were found (all P>0.05). Egger regression tests indicated that there was no publication bias between included RCTs (all P>0.05). DISCUSSION: Intermittent tube feeding for stroke patients with dysphagia during the recovery period can not only ensure the nutritional supply, but also promote the recovery of swallowing function and reduce the occurrence of aspiration and aspiration associated pneumonia.

Amino modified magnetic halloysite nanotube supporting chloroperoxidase immobilization: enhanced stability, reusability, and efficient degradation of pesticide residue in wastewater.

Halloysite nanotube (HNT) is a natural bio-compatible and stable nanomaterial available in abundance at low-cost. In this work, HNT was modified by two strategies to make it suitable for supporting immobilization of chloroperoxidase (CPO). Firstly, Fe3O4 nanoparticles were deposited on HNT, so magnetic separation can be used instead of centrifugation. Then, the magnetic HNT was modified by 3-aminopropyltriethoxysilane (APTES), which can provide amine group on surface of HNT and meanwhile inhibit the agglomeration of magnetic HNT. Then, HNT-Fe3O4 -APTES was linked with branched polyethyleneimine (PEI) to provide more amino for binding with enzyme. The so-prepared CPO@HNT-Fe3O4-APTES-PEI showed enhanced enzyme loading, reusability, improved thermal stability and tolerance to organic solvents than free CPO. For example, after 10 repeated uses, CPO@HNT- Fe3O4-APTES-PEI can maintain 92.20% of its original activity compared with 65.12% of activity of CPO@HNT-APTES-PEI and 45.69% of activity of CPO@HNT. The kinetic parameters indicated the affinity and specificity of immobilized enzyme to substrate was increased. CPO@HNT-Fe3O4-APTES-PEI was very efficient when it was applied in the degradation of pesticides mesotrione in wastewater. The degradation efficiency can reach 90% within 20 min at range of 5-40 µmol·L-1. These results ensure the potential practical application of this bio-materials in wastewater treatment.

Demineralized bone matrix used for direct pulp capping in rats.

OBJECTIVES: To evaluate the wound healing process following direct pulp capping with demineralized bone matrix (DBM) and calcium hydroxide (Ca(OH)2). METHODS: Fifty 8-weeks-old SPF Wistar male rats were divided into two groups: one was the DBM treated group, and the other was the Ca(OH)2 treated group. Pulpotomy was performed on the maxillary first molar of one side of each rat, and the another side was left as the blank control. Rats were sacrificed after each observation period (1, 3, 7, 14 and 28 days) and specimen slices were made. Hematoxylin-Eosin (HE) staining was used for observing the changes of pulp tissue, and immunohistochemical staining was used for observing the expression of reparative dentinogenesis-related factors runt transcription factor 2 (Runx2), type I collagen (COL I), osteocalcin (OCN) and dentin sialoprotein (DSP). RESULTS: Inflammatory cell infiltration (ICI) and pulp tissue disorganization (PTD) could be observed in both the DBM and Ca(OH)2 groups at all observation periods. The DBM group showed slighter ICI on 1 and 28 days and milder PTD on 28 days, with a significant difference (P<0.05). Reparative dentin formation (RDF) could initially be observed on 14 days postoperatively, and the DBM group showed more regular and thinner RDF with significant differences on 14 and 28 days compared with the Ca(OH)2 group (P<0.05). In both groups, the expression of Runx2, COL I, DSP and OCN were positive. Generally, the expression of these four factors in the DBM group was stronger than the Ca(OH)2 group on the same observation periods. CONCLUSIONS: DBM had the ability of inducing odontoblast differentiation and promoting dentinogenesis. DBM could initiate physiologic wound healing in pulp and had the ability to promote reparative dentin formation. Consequently, DBM may be an acceptable alternative for direct pulp capping.

Knowledge mapping of Chinese medicine interdisciplinary research field.

Based on 248 core biomedical journals indexed in the General Contents of Chinese Core Journals (2011 edition) released by Peking University,we established a Chinese Medicine Sciences Citation Index (CMSCI) database; in addition, based on the Chinese Library Classification (4(th) edition), we identified 13 259 articles concerning Chinese medicine interdisciplinary research. The knowledge mapping was performed for keywords co-occurence, total cites of articles, and total cites of authors using the CiteSpace3 software, with an attempt to reveal the research priorities,knowledge sources, and highly influential authors