Study on the Superlubricity Behavior of Ions under External Electric Fields at Steel Interfaces.

Realizing macroscopic superlubricity in the presence of external electric fields (EEFs) at the steel interfaces is still challenging. In this work, macroscopic superlubricity with a coefficient of friction value of approximately 0.008 was realized under EEFs with the lubrication of LiPF6-based ionic liquids at steel interfaces. The roles of cations and anions in the superlubricity realization under EEFs were studied. Based on the experimental results, the macroscopic superlubricity behavior of Li(PEG)PF6 under EEFs at steel interfaces is attributed to the strong hydration effect of Li+ cations and the complete reactions of anions that contributed to the formation of a boundary film on the appropriate surface. Moreover, the reduction in the number of iron oxides in the boundary film on the disc was beneficial for friction reduction. We also provide a calculation model to describe the relationship between the hydration effect and the optimal voltage position, at which the lowest friction might occur. Ultimately, this work proves that macroscopic superlubricity can be realized under EEFs at steel interfaces and provides a foundation for engineering applications of superlubricity in an electrical environment.

Whole-Cell Biotransformation of Penicillin G by a Three-Enzyme Co-expression System with Engineered Deacetoxycephalosporin†C Synthase.

Deacetoxycephalosporin C synthase (DAOCS) catalyzes the transformation of penicillin G to phenylacetyl-7-aminodeacetoxycephalosporanic acid (G-7-ADCA) for which it depends on 2-oxoglutarate (2OG) as co-substrate. However, the low activity of DAOCS and the expense of 2OG restricts its practical applications in the production of G-7-ADCA. Herein, a rational design campaign was performed on a DAOCS from Streptomyces clavuligerus (scDAOCS) in the quest to construct novel expandases. The resulting mutants showed 25∼58 % increase in activity compared to the template. The dominant DAOCS variants were then embedded into a three-enzyme co-expression system, consisting of a catalase and an L-glutamic oxidase for the generation of 2OG, to convert penicillin G to G-7-ADCA in E. coli. The engineered whole-cell enzyme cascade was applied to an up-scaled reaction, exhibiting a yield of G-7-ADCA up to 39.21 mM (14.6 g ⋅ L-1 ) with a conversion of 78.42 mol %. This work highlights the potential of the integrated whole-cell system that may inspire further research on green and efficient production of 7-ADCA.

Multienzymatic cascade synthesis of fucosyloligosaccharide via a two-step fermentation strategy in Escherichia coli.

OBJECTIVES: To achieve multienzymatic cascade synthesis of fucosyl oligosaccharide from D-mannose by two-step fermentation pathway in Escherichia coli. RESULTS: E. coli BL21(DE3) harboring pET-22b(+) vectors with six genes, i.e., glucokinase (Glk), phosphomannomutase (ManB), mannose-1-phosphate guanylytransferase (ManC), GDP-mannose 4,6-dehydratase (Gmd), GDP-4-keto-6-deoxy-D-mannose-3,5-epimerase/4-reductase (WcaG), and α-1,2-fucosyltransferase (Fuct) were co-inoculated, and the multienzyme synthetic pathway was constructed to produce fucosyloligosaccharide using D-mannose as substrate. The product, analyzed by LC/MS, fucosyloligosaccharide was formed under the catalysis of Fuct using GDP-fucose as donor substrate and lactose as acceptor substrate. Fucosyloligosaccharides reached 22 mM by a two-step fermentation compared to 3.7 mM with a one-pot fermentation. CONCLUSIONS: Fucosyloligosaccharide was produced by a two-step fermentation to avoid the inhibitory effect of GDP-fucose on Gmd. Two-step fermentation is a rational synthetic pathway for accumulating fucosyloligosaccharide.

Leptin regulates energy intake but fails to facilitate hibernation in fattening Daurian ground squirrels (Spermophilus dauricus).

Body fat storage before hibernation affects the timing of immergence in Daurian ground squirrels (Spermophilus dauricus). Leptin is an adipose signal and plays vital role in energy homeostasis mainly by action in brain. To test the hypothesis that leptin plays a role in facilitating the process of hibernation, squirrels were administrated with recombinant murine leptin (1µg/day) through intracerebroventricular (ICV) injection for 12 days during fattening. From day 7 to 12, animals were moved into a cold room (5±1°C) with constant darkness which functioned as hibernaculum. Energy intake, body mass and core body temperature (Tb) were continuously monitored throughout the course of experiment. Resting metabolic rate (RMR) was measured under both warm and cold conditions. At the end of leptin administration, we measured the serum concentration of hormones related to energy regulation, mRNA expression of hypothalamic neuropeptides and uncoupling protein 1 (UCP1) levels in brown adipose tissue (BAT). Our results showed that during leptin administration, the cumulative food intake and increase of body mass were suppressed while Tb and RMR were unaltered. The proportion of torpid squirrels was not different between two groups. At the end of leptin administration, the expressions of hypothalamic neuropeptide Y and agouti gene-related protein were suppressed. There were no differences in UCP1 mRNA expression or protein content in BAT between groups. Our data suggest that leptin can affect energy intake via hypothalamic neuropeptides, but is not involved in the initiation of hibernation in fattening Daurian ground squirrels.

Hypolipidemic effect and molecular mechanism of ginsenosides: a review based on oxidative stress.

Hyperlipidemia is considered a risk factor for cardiovascular and endocrine diseases. However, effective approaches for treating this common metabolic disorder remain limited. Ginseng has traditionally been used as a natural medicine for invigorating energy or "Qi" and has been demonstrated to possess antioxidative, anti-apoptotic, and anti-inflammatory properties. A large number of studies have shown that ginsenosides, the main active ingredient of ginseng, have lipid-lowering effects. However, there remains a lack of systematic reviews detailing the molecular mechanisms by which ginsenosides reduce blood lipid levels, especially in relation to oxidative stress. For this article, research studies detailing the molecular mechanisms through which ginsenosides regulate oxidative stress and lower blood lipids in the treatment of hyperlipidemia and its related diseases (diabetes, nonalcoholic fatty liver disease, and atherosclerosis) were comprehensively reviewed. The relevant papers were search on seven literature databases. According to the studies reviewed, ginsenosides Rb1, Rb2, Rb3, Re, Rg1, Rg3, Rh2, Rh4, and F2 inhibit oxidative stress by increasing the activity of antioxidant enzymes, promoting fatty acid ß-oxidation and autophagy, and regulating the intestinal flora to alleviate high blood pressure and improve the body's lipid status. These effects are related to the regulation of various signaling pathways, such as those of PPARα, Nrf2, mitogen-activated protein kinases, SIRT3/FOXO3/SOD, and AMPK/SIRT1. These findings suggest that ginseng is a natural medicine with lipid-lowering effects.

Active and stable alcohol dehydrogenase-assembled hydrogels via synergistic bridging of triazoles and metal ions.

Biocatalysis is increasingly replacing traditional methods of manufacturing fine chemicals due to its green, mild, and highly selective nature, but biocatalysts, such as enzymes, are generally costly, fragile, and difficult to recycle. Immobilization provides protection for the enzyme and enables its convenient reuse, which makes immobilized enzymes promising heterogeneous biocatalysts; however, their industrial applications are limited by the low specific activity and poor stability. Herein, we report a feasible strategy utilizing the synergistic bridging of triazoles and metal ions to induce the formation of porous enzyme-assembled hydrogels with increased activity. The catalytic efficiency of the prepared enzyme-assembled hydrogels toward acetophenone reduction is 6.3 times higher than that of the free enzyme, and the reusability is confirmed by the high residual catalytic activity after 12 cycles of use. A near-atomic resolution (2.1 Å) structure of the hydrogel enzyme is successfully analyzed via cryogenic electron microscopy, which indicates a structure-property relationship for the enhanced performance. In addition, the possible mechanism of gel formation is elucidated, revealing the indispensability of triazoles and metal ions, which guides the use of two other enzymes to prepare enzyme-assembled hydrogels capable of good reusability. The described strategy can pave the way for the development of practical catalytic biomaterials and immobilized biocatalysts.

Phenotypic changes in the metabolic profile and adiponectin activity during seasonal fattening and hibernation in female Daurian ground squirrels (Spermophilus dauricus).

Seasonal hibernation has provided an opportunity to study animals' phenotypic plasticity in adaptation to changing environment. In the present study focusing on the female Daurian ground squirrel (Spermophilus dauricus)-a well demonstrated seasonal hibernator-we examined their behavioral, morphological, and metabolic changes during fattening, hibernation, and emergence. Our data indicated high levels of food intake, fat deposition, and body mass increases during fattening compared to hibernation. The levels of serum glucose and triglycerides were also higher during fattening than during hibernation and emergence. Interestingly, although squirrels showed signs of obesity and elevated triglycerides in serum during fattening, triglyceride levels in the liver and skeletal muscles remained unchanged. Our data also indicated that adiponectin levels in serum and cerebrospinal fluid were different between fattening and hibernation. Levels of adiponectin receptor 1 in the skeletal muscle remained low during fattening but peaked in late hibernation. In contrast, adiponectin receptor 2 in the liver showed a steady increase during fattening, which was followed by a significant decrease at early hibernation. Our data indicate that adiponectin may play an important role in preventing heterotopic fat accumulation in a receptor- and organ-specific manner, as well as in facilitating the switch from glucose metabolism to lipid metabolism during fattening and hibernation in female Daurian ground squirrels.

Chinese herbal formula shen-ling-bai-zhu-san to treat chronic gastritis: Clinical evidence and potential mechanisms.

BACKGROUND: Chronic gastritis (CG) is an inflammatory disease of the gastric mucosa. Shen-ling-bai-zhu san (SLBZS), a traditional Chinese medicine formula, is widely used for treating CG. Nevertheless, its effects are currently unclear. AIM: To determine the clinical evidence and potential mechanisms of SLBZS for the treatment of CG. METHODS: We systematically searched 3 English (PubMed, Embase, Medline) and 4 Chinese databases (Cochrane Library Central Register of Controlled Trials, China National Knowledge Infrastructure database, Wanfang Data Knowledge Service Platform, and the VIP information resource integration service platform) without language or publication bias restriction. Qualified studies were selected according to pre-set inclusion and exclusion criteria. RevMan 5.3 software was used for meta-analysis and literature quality assessment, Stata 14.0 software was used for sensitivity analysis, GRADE profiler 3.6 was used to evaluate the quality of evidence. And then, network pharmacology analysis was applied to primary research the mechanisms of action of SLBZS on CG. RESULTS: Fourteen studies were finally included, covering 1335 participants. Meta-analysis indicated that: (1) SLBZS was superior to conventional therapies [risk ratio (RR): 1.29, 95% confidence interval (CI): 1.21 to 1.37, P < 0.00001]; (2) SLBZS was better than conventional therapies [RR: 0.24, 95% confidence interval (95%CI): 0.11 to 0.55, P = 0.0007] in terms of recurrence rate and reversal of Helicobacter pylori positivity (RR: 1.20, 95%CI: 1.11 to 1.30, P < 0.00001); and (3) The safety of SLBZS for CG remains unclear. According to the GRADE method, the quality of evidence was not high. Besides, SNZJS might treat CG by acting on related targets and pathways such as EGFR tyrosine kinase inhibitor resistance, the PI3K-Akt signaling pathway, and others. CONCLUSION: SLBZS might be useful in treating CG, but long-term effects and specific clinical mechanisms of it maintain unclear. More samples and high-quality clinical experiments should be assessed and verified in the next step.

Data of atrial arrhythmias in hospitalized COVID-19 and influenza patients.

Atrial arrhythmias (AA) are common in hospitalized COVID-19 patients with limited data on their association with COVID-19 infection, clinical and imaging outcomes. In the related research article using retrospective research data from one quaternary care and five community hospitals, patients aged 18 years and above with positive SARS-CoV-2 polymerase chain reaction test were included. 6927 patients met the inclusion criteria. The data in this article provides demographics, home medications, in-hospital events and COVID-19 treatments, multivariable generalized linear regression regression models using a log link with a Poisson distribution (multi-parameter regression [MPR]) to determine predictors of new-onset AA and mortality in COVID-19 patients, computerized tomography chest scan findings, echocardiographic findings, and International Classification of Diseases-Tenth Revision codes. The clinical outcomes were compared to a propensity-matched cohort of influenza patients. For influenza, data is reported on baseline demographics, comorbid conditions, and in-hospital events. Generalized linear regression models were built for COVID-19 patients using demographic characteristics, comorbid conditions, and presenting labs which were significantly different between the groups, and hypoxia in the emergency room. Statistical analysis was performed using R programming language (version 4, ggplot2 package). Multivariable generalized linear regression model showed that, relative to normal sinus rhythm, history of AA (adjusted relative risk [RR]: 1.38; 95% CI: 1.11-1.71; p = 0.003) and newly-detected AA (adjusted RR: 2.02 95% CI: 1.68-2.43; p < 0.001) were independently associated with higher in-hospital mortality. Age in increments of 10 years, male sex, White race, prior history of coronary artery disease, congestive heart failure, end-stage renal disease, presenting leukocytosis, hypermagnesemia, and hypomagnesemia were found to be independent predictors of new-onset AA in the MPR model. The dataset reported is related to the research article entitled "Incidence, Mortality, and Imaging Outcomes of Atrial Arrhythmias in COVID-19" [Jehangir et al. Incidence, Mortality, and Imaging Outcomes of Atrial Arrhythmias in COVID-19, American Journal of Cardiology] [1].

Incidence, Mortality, and Imaging Outcomes of Atrial Arrhythmias in COVID-19.

Atrial arrhythmias (AAs) are common in hospitalized patients with COVID-19; however, it remains uncertain if AAs are a poor prognostic factor in SARS-CoV-2 infection. In this retrospective cohort study from 2014 to 2021, we report in-hospital mortality in patients with new-onset AA and history of AA. The incidence of new-onset congestive heart failure (CHF), hospital length of stay and readmission rate, intensive care unit admission, arterial and venous thromboembolism, and imaging outcomes were also analyzed. We further compared the clinical outcomes with a propensity-matched influenza cohort. Generalized linear regression was performed to identify the association of AA with mortality and other outcomes, relative to those without an AA diagnosis. Predictors of new-onset AA were also modeled. A total of 6,927 patients with COVID-19 were included (626 with new-onset AA, 779 with history of AA). We found that history of AA (adjusted relative risk [aRR] 1.38, confidence interval [CI], 1.11 to 1.71, p = 0.003) and new-onset AA (aRR 2.02, 95% CI 1.68 to 2.43, p <0.001) were independent predictors of in-hospital mortality. The incidence of new-onset CHF was 6.3% in history of AA (odds ratio 1.91, 95% CI 1.30 to 2.79, p <0.001) and 11.3% in new-onset AA (odds ratio 4.01, 95% CI 3.00 to 5.35, p <0.001). New-onset AA was shown to be associated with worse clinical outcomes within the propensity-matched COVID-19 and influenza cohorts. The risk of new-onset AA was higher in patients with COVID-19 than influenza (aRR 2.02, 95% CI 1.76 to 2.32, p <0.0001), but mortality associated with new-onset AA was higher in influenza (aRR 12.58, 95% CI 4.27 to 37.06, p <0.0001) than COVID-19 (aRR 1.86, 95% CI 1.55 to 2.22, p <0.0001). In a subset of the patients with COVID-19 for which echocardiographic data were captured, abnormalities were common, including valvular abnormalities (40.9%), right ventricular dilation (29.6%), and elevated pulmonary artery systolic pressure (16.5%); although there was no evidence of a difference in incidence among the 3 groups. In conclusion, new-onset AAs are associated with poor clinical outcomes in patients with COVID-19.

Impact of Urban Morphology and Climate on Heating Energy Consumption of Buildings in Severe Cold Regions.

This study aims to acquire a better understanding of the quantitative relationship between environmental impact factors and heating energy consumption of buildings in severe cold regions. We analyze the effects of five urban morphological parameters (building density, aspect ratio, building height, floor area ratio, and shape factor) and three climatic parameters (temperature, wind speed, and relative humidity) on the heating energy use intensity (EUI) of commercial and residential buildings in a severe cold region. We develop regression models using empirical data to quantitatively evaluate the impact of each parameter. A stepwise approach is used to ensure that all the independent variables are significant and to eliminate the effects of multicollinearity. Finally, a spatial cluster analysis is performed to identify the distribution characteristics of heating EUI. The results indicate that the building height, shape factor, temperature, and wind speed have a significant impact on heating EUI, and their effects vary with the type of building. The cluster analysis indicated that the areas in the north, east, and along the river exhibited high heating EUI. The findings obtained herein can be used to evaluate building energy efficiency for urban planners and heating companies and departments based on the surrounding environmental conditions.

Differential analysis of lymph node metastasis in histological mixed-type early gastric carcinoma in the mucosa and submucosa.

AIM: To investigate the relationship between histological mixed-type of early gastric cancer (EGC) in the mucosa and submucosa and lymph node metastasis (LNM). METHODS: This study included 298 patients who underwent gastrectomy for EGC between 2005 and 2012. Enrolled lesions were divided into groups of pure differentiated (pure D), pure undifferentiated (pure U), and mixed-type according to the proportion of the differentiated and undifferentiated components observed under a microscope. We reviewed the clinicopathological features, including age, sex, location, size, gross type, lymphovascular invasion, ulceration, and LNM, among the three groups. Furthermore, we evaluated the predictors of LNM in the mucosa-confined EGC. RESULTS: Of the 298 patients, 165 (55.4%) had mucosa-confined EGC and 133 (44.6%) had submucosa-invasive EGC. Only 13 (7.9%) cases of mucosa-confined EGC and 30 (22.6%) cases of submucosa-invasive EGC were observed to have LNM. The submucosal invasion (OR = 4.58, 95%CI: 1.23-16.97, P = 0.023), pure U type (OR = 4.97, 95%CI: 1.21-20.39, P = 0.026), and mixed-type (OR = 5.84, 95%CI: 1.05-32.61, P = 0.044) were independent risk factors for LNM in EGC. The rate of LNM in mucosa-confined EGC was higher in the mixed-type group (P = 0.012) and pure U group (P = 0.010) than in the pure D group, but no significant difference was found between the mixed-type group and pure U group (P = 0.739). Similarly, the rate of LNM in the submucosa-invasive EGC was higher in the mixed-type (P = 0.012) and pure U group (P = 0.009) than in the pure D group but was not significantly different between the mixed-type and pure U group (P = 0.375). Multivariate logistic analysis showed that only female sex (OR = 5.83, 95%CI: 1.64-20.70, P = 0.028) and presence of lymphovascular invasion (OR = 13.18, 95%CI: 1.39-125.30, P = 0.020) were independent risk factors for LNM in mucosa-confined EGC, while histological type was not an independent risk factor for LNM in mucosa-confined EGC (P = 0.106). CONCLUSION: For mucosal EGC, histological mixed-type is not an independent risk factor for LNM and could be managed in the same way as the undifferentiated type.

Tumor rupture of gastric gastrointestinal stromal tumors during endoscopic resection: a risk factor for peritoneal metastasis?

BACKGROUND AND STUDY AIMS: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract. Up to the present time, complete surgical excision has been the standard treatment for primary GISTs greater than 2 cm. It is well known that tumor rupture during surgery is an independent risk factor for peritoneal metastasis; however, it is not known whether the risk of peritoneal metastasis increases in cases where the tumor is ruptured during endoscopic resection. PATIENTS AND METHODS: A total of 195 patients treated for GIST between January 2014 and December 2016 in our hospital were enrolled in this study. They were divided into two groups according to whether the tumor was ruptured during endoscopic resection. The rate of peritoneal metastasis in patients in the two groups who also suffered perforation was investigated from the follow-up results. RESULTS: Approximately 55.4 % of all patients were female and the average age of the study group was 59.0 ±â€Š10.3 years. Of the 195 patients, the tumors in 27 were ruptured and the remaining 168 patients underwent en bloc resection. There was no statistically significant difference in gender or age between the two groups. The median tumor size (maximum diameter) in all patients was 1.5 cm (0.3 - 5.0 cm): 2.5 cm (0.8 - 5.0 cm) and 1.4 cm (0.3 - 4.0 cm) in the tumor rupture group and en bloc resection group, respectively ( P  < 0.001). Most of the tumors were located in the gastric fundus. At a median follow-up of 18.7 ±â€Š10.2 months, neither tumor recurrence (liver metastasis, peritoneal metastasis, local recurrence) nor mortality related to GISTs were detected. CONCLUSIONS: Tumor rupture during endoscopic resection of gastric GISTs may not be a risk factor for peritoneal metastasis.

[Effects of oculo-acupuncture therapy on colonic serotonin reuptake transporter expression in rats with irritable bowel syndrome].

OBJECTIVE: To investigate the effect of oculo-acupuncture therapy (OAT) on the alteration of colonic serotonin reuptake transporter (SERT) expression in rats with irritable bowel syndrome (IBS) so as to explore its underlying mechanism in relieving IBS. METHODS: Thirty male Wistar rats were randomized into control, IBS model and OAT groups (n = 10/group). IBS model was established by repeated stress stimulation [water-intake inhibition (24 h), warm box keeping (40 degrees C,5 min), electric shock stimulation (30 V, 120 s), forced cool water swimming (14 t, 5 min), 24 h fasting, and tail clamping (180 s)] for 18 days. Oculo-acupuncture stimulation was given to "Xiajiao" (Lower Energizer), "Dachang" (Large Intestine), "Gan" (Liver) and "Pi" (Spleen) areas for 20 min by using filiform acupuncture needles (manipulated 1 min once every 10 min). The treatment was conducted once every 12 h for 7 days. Colonic SERT mRNA and protein expression levels were examined by RT-PCR and Western Blot. RESULTS: In comparison with the control group, the expression levels of both colonic SERT mRNA and protein in the model group were down-regulated remarkably (P < 0.05). Compared with the model group, the expression levels of SERT gene and protein in the OAT group were increased remarkably (P < 0.05). CONCLUSION: OAT can increase colonic SERT protein and gene expression in IBS rats, which may play a role in relieving IBS in OAT clinic.