Built-in Electric Fields in Heterostructured Lamellar Membranes Enable Highly Efficient Rejection of Charged Mass.

Separation membranes with homogeneous charge channels are the mainstream to reject charged mass by forming electrical double layer (EDL). However, the EDL often compresses effective solvent transport space and weakens channel-ion interaction. Here, built-in electric fields (BIEFs) are constructed in lamellar membranes by assembling the heterostructured nanosheets, which contain alternate positively-charged nanodomains and negatively-charged nanodomains. We demonstrate that the BIEFs are perpendicular to horizontal channel and the direction switches alternately, significantly weakening the EDL effect and forces ions to repeatedly collide with channel walls. Thus, highly efficient rejection for charged mass (salts, dyes, and organic acids/bases) and ultrafast water transport are achieved. Moreover, for desalination on four-stage filtration option, salt rejection reaches 99.9 % and water permeance reaches 19.2 L m-2 h-1 bar-1. Such mass transport behavior is quite different from that in homogeneous charge channels. Furthermore, the ion transport behavior in nanochannels is elucidated by validating horizontal projectile motion model.

Analysis of droplet size uniformity and selection of spray parameters based on the biological optimum particle size theory.

Based on the theory of biological optimal particle size, the most easily attached droplets for different organisms have different particle sizes. To achieve the best average particle size, the droplet size in the atomization field must be more uniform and attain a high the adhesion rate. Therefore, during the application process, not only the average particle size of the droplets but also the influence of the uniformity of the droplets in the spray field must be considered. In this study, 20 small-angle fan nozzles ranging from 20° to 40° are used as the research objects. The droplet size information in the atomization field is obtained using a laser particle size analyzer, and the droplet uniformity under different parameters is calculated. The results showed that within the range of the parameters selected in the experiment, the droplet size increased with an increase in the flow rate, and decreased with an increase in the pressure. In addition, the angle had little effect on the droplet size. Increasing the spray height, spray angle, and pressure, while reducing the equivalent outlet diameter of the nozzle was beneficial to improve the uniformity of droplets. The order of the degree of influence of the four parameters on the uniformity of the droplets was height > equivalent outlet diameter (r) > pressure > spray angle, and the influence weights were 51.1%, 37.1%, 7.8%, 4.1%; 48.4%, 37.6%, 10%, and 4%. Under the condition of the parameter settings used in this experiment, the optimal atomization effect for the four intervals of 150-200 µm, 200-250 µm, 250-300 µm, and 300-400 µm was analyzed from the perspective of uniformity. The nozzle models with the best atomization effects in each interval were SS4003-0.3 MPa, SS4006-0.3 MPa, SS4008-0.3 MPa, and 633.512.30.CC-0.1 MPa.

Exploring the metabolic fate of propanol in industrial erythromycin-producing strain via 13C labeling experiments and enhancement of erythromycin production by rational metabolic engineering of Saccharopolyspora erythraea.

Propanol had been widely used as a precursor for erythromycin synthesis in industrial production. However, the knowledge on the exact metabolic fate of propanol was still unclear. In the present study, the metabolic fate of propanol in industrial erythromycin-producing strain Saccharopolyspora erythraea E3 was explored via 13C labeling experiments. An unexpected pathway in which propanol was channeled into tricarboxylic acid cycle was uncovered, resulting in uneconomic catabolism of propanol. By deleting the sucC gene, which encodes succinyl-CoA synthetase that catalyse a reaction in the unexpected propanol utilization pathway, a novel strain E3-ΔsucC was constructed. The strain E3-ΔsucC showed a significant enhancement in erythromycin production in the chemically defined medium compared to E3 (786.61 vs 392.94 mg/L). Isotopically nonstationary 13C metabolic flux analysis were employed to characterize the metabolic differences between Saccharopolyspora erythraea E3 and E3-ΔsucC. The results showed that compared with the starting strain E3, the fluxes of pentose phosphate pathway in E3-△sucC increased by almost 200%. The flux of the metabolic reaction catalyzed by succinyl-CoA synthetase in E3-ΔsucC was almost zero, while the glyoxylate bypass flux significantly increased. These new insights into the precursor utilization of antibiotic biosynthesis by rational metabolic engineering in Saccharopolyspora erythraea provided the new vision in increasing industrial production of secondary metabolites.

Loss of Dec1 prevents autophagy in inflamed periodontal ligament fibroblast.

Periodontal ligament fibroblasts (PDLFs) are integral to the homeostasis of periodontal tissue. The transcription factor Dec1 functions to modulate Porphyromonas gingivalis-induced periodontal inflammation. Here, we aimed to characterize the Dec1-mediated autophagy in PDLFs under inflammatory conditions. Human PDLFs were subjected to an inflammatory environment using P. gingivalis Lipopolysaccaride (LPS) along with Dec1 siRNA in vitro. Quantitative real-time polymerase chain reaction and Western blot analyses were used to evaluate the expression levels of autophagy-related genes and their upstream AKT/mTOR signaling pathways. An experimental P. gingivalis-treated Dec1 knockout (Dec1KO) mouse model was used to confirm the expression of autophagy in PDLFs in vivo. Treatment with P. gingivalis LPS induced the expression of ATG5, Beclin1 and microtubule-associated protein 1 light chain 3 (LC3) and elevated the expression of pro-inflammatory cytokine IL-1ß and Dec1 in human PDLFs. Knockdown of Dec1 partly reversed the detrimental influences of LPS on these autophagy markers in human PDLFs. The inhibition of autophagy with Dec1 siRNA suppressed the inflammatory effect of AKT/mTOR signaling pathways following treatment with P. gingivalis LPS. P. gingivalis-treated Dec1KO mice partly reduced autophagy expression. These findings suggest that a Dec1 deficiency can modulate the interaction between autophagy and inflammation in PDLFs.

Epigallocatechin gallate affects the proliferation of human alveolar osteoblasts and periodontal ligament cells, as well as promoting cell differentiation by regulating PI3K/Akt signaling pathway.

Human periodontal ligament cells (hPDLCs) and human alveolar osteoblasts (hAOBs) play pivotal roles in periodontium. The regulatory effects of epigallocatechin gallate (EGCG) on hPDLCs and hAOBs remained unclear. This study probed into the functions of EGCG treating periodontal diseases. Cultured hAOBs and hPDLCs were passaged and observed by microscopic examination, and alkaline phosphatase (ALP) and immumohistochemical staining were performed for verification. hAOBs and hPDLCs were treated with EGCG and LY294002 + EGCG, then the proliferation of the two cells was assayed by MTT. Mineralization of the treated hAOBs and hPDLCs was detected by ALP activity experiment and Alizarin Red S staining kit. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were performed for the detection of the expressions of differentiation-related mRNAs and PI3K/Akt signaling pathway-related proteins in the two cells. The third passage of hAOBs mainly showed triangle shape and were positive by ALP staining. hPDLCs in passage 3 adhered to the wall in spiral or radial pattern with positively stained vimentin and negatively stained keratin. Cell proliferation and ALP activity of the hAOBs and hPDLCs were increased by EGCG treatment. The mineralized nodules and expressions of differentiation-related mRNAs, the phosphorylation of PI3K and Akt of the hAOBs and hPDLCs were promoted by EGCG treatment, while the effects of LY294002 treatment were opposite to EGCG treatment. Epigallocatechin gallate affected the proliferation and differentiation of hAOBs and hPDLCs through regulating PI3K/Akt signaling pathway.

Enantioselective Total Synthesis of (-)-Spiroxins A, C, and D.

Spiroxins A, C, and D are metabolites that have been identified in the marine fungal strain LL-37H248. Their unique polycyclic structures and intriguing biological activities make them attractive targets for the synthetic community. Based on a scalable enantioselective epoxidation of 5-substituted naphthoquinone, an oxidation/spiroketalization cascade, ortho-selective chlorination of the phenol unit, and oxime-ester-directed acetoxylation, an enantioselective total synthesis of (-)-spiroxins A and C and the first total synthesis of (-)-spiroxin D have been achieved.

Blocking the flow of propionate into TCA cycle through a mutB knockout leads to a significant increase of erythromycin production by an industrial strain of Saccharopolyspora erythraea.

A high erythromycin producing mutant strain Saccharopolyspora erythraea HL3168 E3-ΔmutB was constructed by deleting mutB (SACE_5639) gene encoding the beta subunit of methylmalonyl-CoA mutase of an industrial strain of S. erythraea HL3168 E3. Industrial media and process control strategies were adopted in a 5 L bioreactor for characterizing the physiological parameters. The total erythromycin titer and erythromycin A concentration in mutant were 46.9 (12740.5 µg/mL) and 64.9 % (8094.4 µg/mL) higher than those in original strain, respectively, which were comparable to industrial erythromycin production. The specific glucose and n-propanol consumption rates were increased by 52.4 and 39.8 %, respectively. During the rapid erythromycin synthesis phase, the yield of erythromycin on n-propanol also increased from 24.3 % in control group to 66.9 % in mutant group. Meanwhile, the specific formation rates of methylmalonyl-CoA and propionyl-CoA, two crucial precursors for erythromycin synthesis, were 1.89- and 2.02-folds higher in the mutant strain, respectively.

Emerging catalysts for the ambient synthesis of ethylene glycol from CO2 and its derivatives.

Ethylene glycol (EG), a useful chemical raw material, has been widely applied in many aspects of modern society. The conventional preparation of ethylene glycol mainly uses the petroleum route at high temperatures and pressure. More and more approaches have been developed to synthesize EG from CO2 and its derivatives under mild conditions. In this review, the ambient synthesis of EG from thermocatalysis, photocatalysis, and electrocatalysis is highlighted. The coal-to-ethylene glycol technology, one of the typical thermal catalysis routes for EG preparation, is relatively mature. However, it still faces some problems to be solved in industrialization. The recent progress in the development of coal-to-ethylene glycol technology is introduced. The main focus is on how to realize the preparation of EG under mild conditions. The strategies include doping promoters, modification of supports, design of catalysts with special structures, etc. Furthermore, the emerging technological progress of photocatalytic and electrocatalytic ethylene glycol synthesis under ambient conditions is introduced. Compared with the thermal catalytic reaction, the reaction conditions are milder. However, there are still many problems in large-scale production. Finally, we propose future development issues and related prospects for the ambient synthesis of EG using different catalytic routes.

Impact of preparation method on nickel speciation and methane dry reforming performance of Ni/SiO2 catalysts.

The methane dry reforming reaction can simultaneously convert two greenhouse gases (CH4 and CO2), which has significantly environmental and economic benefits. Nickel-based catalysts have been widely used in methane dry reforming in past decade due to their low cost and high activity. However, the sintering and coke deposition of catalysts severely limit their industrial applications. In this paper, three Ni/SiO2 catalysts prepared by different methods were systematically studied, and the samples obtained by the ammonia evaporation method exhibited excellent catalytic performance. The characterization results such as H2-TPR, XPS and TEM confirmed that the excellent performance was mainly attributed to the catalyst with smaller Ni particles, stronger metal-support interactions, and abundant Ni-O-Si units on the catalyst surface. The anti-sintering/-coking properties of the catalyst were significantly improved. However, the Ni/SiO2-IM catalyst prepared by impregnation method had uneven distribution of nickel species and large particles, and weak metal-support interactions, showing poor catalytic performance in methane dry reforming. Since the nickel species were encapsulated by the SiO4 tetrahedral network, the Ni/SiO2-SG catalyst prepared by sol-gel method could not expose more effective active sites even if the nickel species were uniformly dispersed, resulting in poor dry reforming performance. This study provides guidance for the preparation of novel anti-sintering/-coking nickel-based catalysts.

Clinical Outcomes of Permanent Left Bundle Branch Area Pacing in Patients With Left Bundle Branch Block and Left Ventricular Ejection Fraction >35 vs. ≤35.

Aims: The present study aimed to compare the effects of left bundle branch area pacing (LBBAP) on cardiac function and clinical outcomes in patients with left bundle branch block (LBBB) and left ventricular ejection fraction (LVEF) >35 vs. ≤35%. Methods and Results: Thirty-six consecutive patients with LBBB and LVEF <50% were enrolled. All patients were followed up for a mean of 6 months. The successful LBBAP was defined as a paced QRS complex presented as right bundle branch block (RBBB) morphology and QRSd < 130 ms. Echocardiography parameters, pacing parameters and clinical outcomes were collected. The successful LBBAP was achieved in 77.8% of all cases (28/36). In LVEF > 35% group (70 ± 8 years, 9 male), the success rate was 81.0% (17/21). QRSd significantly decreased from 174 ± 23 ms to 108 ± 13 ms (P < 0.001). The pacing threshold and R-wave amplitude were 0.6 ± 0.2 V @ 0.5 ms and 12 ± 7 mV, respectively. In LVEF ≤ 35% group (69 ± 5 years, 9 male), the success rate was 73.3% (11/15) with QRSd decreasing from 188 ± 25 ms to 107 ± 11 ms (P < 0.001). The hyperresponders to LBBAP (functional recovery and LVEF ≥ 50%) in LVEF > 35% group was 52.9%, which were almost twice of that in LVEF ≤ 35% group (33.3%). Whether patients had LBBAP or left ventricular septal pacing (LVSP), patients in the LVEF > 35% group showed significantly lower incidence of heart failure hospitalizations or death from any cause (hazard ratio in LVEF > 35% group, 0.22; 95%CI, 0.06 to 0.75, P = 0.011). Conclusions: LBBAP can significantly shorten the QRSd and improve cardiac function in LBBB patients with either LVEF > 35 or ≤ 35%. LBBAP should be considered as an effective therapy for preventing the deterioration of cardiac function in early-stage heart failure patients with LBBB and LVEF > 35%.

Reversible T-wave inversions during left bundle branch area pacing.

BACKGROUND: Our clinical observation found that T-wave inversions (TWIs) appeared during left bundle branch area pacing (LBBAP); however, the incidence and influencing factors were unclear. The study aimed to investigate the effects of LBBAP on T-wave and explore possible factors associated with TWIs. METHODS: This was a retrospective cohort study. An electrocardiogram (ECG) was acquired at baseline and after LBBAP. Baseline characteristics, ECG parameters, LBBAP parameters, and troponin T (TnT) levels were compared between the non-TWIs and TWIs groups. Multivariable logistic analyses were performed to adjust for potential confounders to identify the predictive factors of TWIs during LBBAP. RESULTS: A total of 398 consecutive patients who underwent successful LBBAP were assessed for inclusion between May 2017 and Jan 2021, and 264 (66.3%) patients had TWIs. The mean (standard deviation [SD]) baseline QRS duration (QRSd) was longer in the TWIs group compared to the non-TWIs group (125.9 [34.5] ms vs. 98.2 [18.1] ms; P <0.001). Multivariable logistic regression analysis suggested that QRSd >120 ms was an independent predictor for TWIs. TWIs were partially or com-pletely recovered in 151/172 (87.8%) patients during follow-up, the median (interquartile range [IQR]) follow-up duration was 10 days (7 days to 5.5 months). TWIs in patients with complete left bundle branch block (CLBBB) occurred more frequently in inferior wall leads (II, III, and aVF) and anterior wall leads (V1-V4) (P <0.05). Patients with complete right bundle branch block (CRBBB) were more prone to TWIs in high lateral wall leads (I and aVL) (P <0.05). There were no significant differences in TnT levels between the TWIs and non-TWIs groups. CONCLUSIONS: TWIs during LBBAP were clinically frequent and recoverable. QRSd >120 ms was independently associated with TWIs.

Construction of a theoretical model for fan nozzles with precise atomization angles for plant protection.

The fan nozzle is widely used in the process of pest control in agriculture and forestry. The spray angle of the nozzle is an important characterization parameter in the atomization of liquids. The spray angle of the nozzle is an important characterizing parameter in the liquid atomization process. It affects the flow field at the exit of the nozzle, thereby affecting the size and velocity of the droplets, and further affecting the deposition effect of the droplets on the crop. Therefore, its research is of great significance for improving the deposition of liquid on plants and controlling pests and related diseases. Based on the classical theory of predecessors and considering the parameters of the flat fan nozzle, we further optimized the theory at the structural level by means of a simulation test and built a spray angle theoretical model taking into account the parameters of the inner chamber of the nozzle. We arrived at the following conclusions: (1) the average error of the spray angle measured by the simulation test and the actual test spray angle was 2.95%, the maximum spray angle deviation value was 2.81°, and the result proves that the simulation test parameter setting is accurate; and (2) the average error between the actual measured value and the theoretical model calculation value was 3.56%, the maximum spray angle deviation was 4°, through the actual test comparison, and the spray angle error of the theoretical model was within the allowable error range of industry production. It was proved that the model could effectively reflect the changing law of spray angle of the flat fan nozzle.

Feasibility and safety of left bundle branch area pacing in very elderly patients (≥80 years).

BACKGROUND: Left bundle branch area pacing (LBBAP) has emerged as a promising physiologic pacing strategy. Though many clinical studies have established the feasibility and safety of LBBAP, the data for very elderly patients are lacking. AIMS: This study aimed to assess the feasibility and safety of LBBAP in very elderly patients (≥80 years). METHODS: Two hundred and forty consecutive patients who received LBBAP implantation were retrospectively enrolled in the present study. Inclusion criteria were patients with atrioventricular block, atrial fibrillation with a slow ventricular response, and heart failure with bundle branch block. The patients were divided into two groups: those aged ≥80 years and those aged <80 years. LBBAP implantation was successfully performed in 48 of 53 (90.6%) very elderly patients and 162 of 187 (86.5%) counterparts. In the very elderly group, the mean (standard deviation [SD]) age was 84 (3) years, mean (SD) paced QRS duration was 112.4 (9.0), and the mean (SD) stimulus to R wave peak time was 82.0 (14.2) ms. Mean (SD) pacing thresholds and mean (SD) R wave sensing were 0.61(0.21) V and 12.1 (4.7) mV at implant. Pacing parameters in very elderly patients were similar to those in their counterparts. During a median follow-up of 6 months, pacing parameters remained stable. Five patients in the very elderly group developed complications (1 with septal perforation during the procedure, 1 with pocket hematoma, 1 with pacing threshold increase, and 2 with micro lead dislodgement during follow-up). CONCLUSION: LBBAP is safe and effective in patients ≥80 years old. LBBAP can be considered as an alternative method for delivering physiological pacing in this special population.

[Evaluation on hepatotoxicity caused by Dioscorea bulbifera based on analysis of bile acids].

Metabolic profile of bile acids was used to evaluate hepatotoxicity of mice caused by ethanol extraction of Dioscorea bulbifera L. (ethanol extraction, ET) and diosbulbin B (DB), separately. Ultra-performance liquid chromatography coupled with quadrupole mass spectrometry (UPLC-MS) was applied to determine the contents of all kinds of endogenous bile acids including free bile acids, taurine conjugates and glycine conjugates. Obvious liver injuries could be observed in mice after administrated with ET and DB. Based on the analysis using principle components analysis (PCA), toxic groups could be distinguished from their control groups, which suggested that the variance of the contents of bile acids could evaluate hepatotoxicity caused by ET and DB. Meanwhile, ET and DB toxic groups were classified in the same trends comparing to control groups in the loading plot, and difference between the two toxic groups could also be observed. DB proved to be one of the toxic components in Dioscorea bulbifera L. Bile acids of tauroursodeoxycholic acid (TUDCA), taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), taurodeoxycholic acid (TDCA), cholic acid (CA) and others proved to be important corresponds to ET and DB induced liver injury according to analysis of partial least square-discriminant analysis (PLS-DA) and the statistical analysis showed that there were significant differences between the control groups and toxic groups (P < 0.01). Furthermore, good correlation could be revealed between the foregoing bile acids and ALT, AST. It indicated that taurine conjugated bile acids as TUDCA, TCDCA, TCA and TDCA along with CA could be considered as sensitive biomarkers of ET and DB induced liver injury. This work can provide the base for the further research on the evaluation and mechanism of hepatotoxicity caused by Dioscorea bulbifera L.

Validation of the 2020 AHA/ACC Risk Stratification for Sudden Cardiac Death in Chinese Patients With Hypertrophic Cardiomyopathy.

Background: Sudden cardiac death (SCD) is a common cause of death in hypertrophic cardiomyopathy (HCM), but identification of patients at a high risk of SCD is challenging. The study aimed to validate the three SCD risk stratifications recommended by the 2011 ACCF/AHA guideline, the 2014 ESC guideline, and the 2020 AHA/ACC guideline in Chinese HCM patients. Methods: The study population consisted of a consecutive cohort of 511 patients with HCM without a history of SCD event. The endpoint was a composite of SCD or an equivalent event (appropriate implantable cardioverter defibrillator therapy or successful resuscitation after cardiac arrest). Results: During a follow-up of 4.7 ± 1.7 years, 15 patients (2.9%) reached the SCD endpoint and 12 (2.3%) were protected by implantable cardioverter defibrillator for primary prevention. A total of 13 (2.8%) patients experiencing SCD events were misclassified as low-risk patients by the 2011 ACCF/AHA guideline, 12 (2.3%) by the 2014 ESC model, and 7 (1.6%) by the 2020 AHA/ACC guideline. The SCD risk stratification in the 2020 AHA/ACC guideline showed greater area under the curve (0.71; 95% CI 0.56-0.87, p < 0.001) than the one in the 2011 ACCF/AHA guideline (0.52; 95% CI 0.37-0.67, p = 0.76) and 2014 ESC guideline (0.68; 95% CI 0.54-0.81, p = 0.02). Conclusion: The SCD risk stratification recommended by the 2020 AHA/ACC guideline showed a better discrimination than previous stratifications in Chinese patients with HCM. A larger multicenter, independent, and prospective study with long-term follow-up would be warranted to validate our result.

Dec2 attenuates autophagy in inflamed periodontal tissues.

INTRODUCTION: Transcriptional regulation of autophagy depends on the transcription factors coordinated inflammatory feedback mechanism. Here, we provide a comprehensive functional characterization of periodontal ligament fibroblasts (PDLFs) treated with Porphyromonas gingivalis lipopolysaccharide (LPS), aiming to reveal previously unappreciated biological changes and to investigate how a transcription factor differentiated embryonic chondrocytes 2 (Dec2)-deficient environment influences the function of autophagy in nflamed human PDLFs. METHODS: A Dec2-deficient (Dec2KO) experimental periodontal inflammation mouse model and treatment with P. gingivalis LPS were employed to examine the role of autophagy in PDLFs using hematoxylin and eosin staining and immunohistochemistry in vivo. A Dec2 small interfering RNA (siRNA) was used to modulate autophagy, and the effect of autophagy on the Dec2 pathway was explored using real-time polymerase chain reaction and western blot analysis in vitro. RESULTS: LPS-treated human PDLFs (HPDLFs) induced autophagy, as demonstrated by the enhanced levels of microtubule-associated protein 1 light chain 3-II (LC3-II) and the induction of ATG5, Beclin1, and Dec2. Compared with a scrambled siRNA, a Dec2 siRNA triggered the detrimental influences of LPS and markedly enhanced autophagy expression in inflamed HPDLFs. The expression of phosphorylated ERK was increased and levels of phosphorylated mammalian target of rapamycin (mTOR) were decreased after exposure to LPS in Dec2 siRNA transfected HPDLFs. The Dec2KO model exhibited that P. gingivalis in Dec2 deficient conditions increases the inflammation of PDLFs by regulating autophagy. CONCLUSIONS: These results demonstrate that a Dec2 deficiency can alleviate LPS-induced inflammation via the ERK/mTOR signaling pathway by regulating autophagy, conceivably delivering a novel approach for the detection of periodontal treatments.