Effect of insulin and metformin on methylation and glycolipid metabolism of peroxisome proliferator-activated receptor γ coactivator-1A of rat offspring with gestational diabetes mellitus

AbstractObjectiveTo discuss the effect of insulin and metformin on a methylation and glycolipid metabolism of peroxisome proliferator-activated receptor γ coactivator-1A (PPARGC1A) of rat offspring with gestational diabetes mellitus (GDM).MethodsA total of 45 pregnant rats received the intraperitoneal injection of streptozotocin to establish the pregnant rat model of GDM. A total of 21 pregnant rats with GDM were randomly divided into three groups, with 7 rats in each group, namely the insulin group, metformin group and control group. Rats in the insulin group received the abdominal subcutaneous injection of 1 mL/kg recombinant insulin glargine at 18:00 every day. Rats in the metformin group received the intragastric infusion of metformin hydrochloride at 18:00 every day, with the first dose of 300 mg/kg. The doses of two groups were adjusted every 3 d to maintain the blood glucose level at 2.65–7.62 mmol/L. Rats in the control group received the intragastric infusion of 1 mL normal saline at 18:00 every day. After the natural delivery of pregnant rats, 10 offspring rats were randomly selected from each group. At birth, 4 wk and 8 wk after the birth of offspring rats, the weight of offspring rats was measured. The blood glucose level of offspring rats was measured at 4 wk and 8 wk, while the level of serum insulin, triglyceride and leptin was measured at 8 wk.ResultsThe weight of offspring rats at birth in the insulin group and metformin group was significantly lower than the one in the control group (P < 0.05), and there was no significant difference at 4 wk and 8 wk among three groups (P > 0.05). The fasting blood glucose and random blood glucose in the insulin group and metformin group at 4 wk and 8 wk were all significantly lower than ones in the control group (P < 0.05); there was no significant difference between the insulin group and metformin group (P > 0.05). The expression of PPARGC1A mRNA in the insulin group and metformin group was significantly higher and the methylation level of PPARGC1A was significantly lower than the one in the control group (P < 0.05); but there was no significant difference between the insulin group and metformin group (P > 0.05). Insulin and leptin at 8 wk in the insulin group and metformin group were significantly higher, while triglyceride was significantly lower than the one in the control group (P < 0.05); triglyceride level in the insulin group was significantly higher than the one in the metformin group (P < 0.05). There was no significant difference in insulin and leptin level between the insulin group and metformin group (P > 0.05).ConclusionsGDM can induce the methylation of PPARGC1A of offspring rats to reduce the expression of PPARGC1A mRNA and then cause the disorder of glycolipid metabolism when the offspring rats grow up; the insulin or metformin in the treatment of pregnant rats with GDM can reduce the methylation level of PPARGC1A and thus improve the abnormal glycolipid metabolism of offspring rats

Study on Wear Resistance of Nickel Cladding Layer with Imitation Shell Convex Strip Structure on the Surface of 7075 Aluminum Alloy Drill Pipe

In this study, a nickel cladding layer with a bionic convex strip structure was applied to the surface of an aluminum alloy drill pipe, and laser cladding technology was used to improve the wear resistance of the aluminum alloy drill pipe. Firstly, by observing the morphological characteristics of the shell surface, the ratio of the width of the convex strips to the spacing between the convex strips was obtained as 0.39–0.53, and thus a model of the bionic structure was constructed. Numerical simulations were performed, and the results showed that the wear of the bionic structure was reduced by 77.6% compared with that of the smooth structure. Subsequently, the cladding layers of both structures were coated on the drill pipe using nickel powder as the material, and wear tests were performed. The microstructure, composition, and hardness behavior of the cladding layers were analyzed using scanning electron microscopy, an X-ray diffractometer, and a microhardness tester. It was found that the cladding layer mainly consists of Al3Ni2, and there is a transition layer between the cladding layer and the aluminum alloy matrix, whose hardness is lower than that of Al3Ni2. In addition, the groove space can be formed between the convex strips, which effectively reduces the frequency of the debris flow. The results of the wear tests show that the wear of the cladding layer with the bionic structure is reduced by 74.0%. Similar results in numerical simulations and experiments verified that the designed cladding layer with a bionic convex strip structure can significantly improve the wear resistance of aluminum alloy drill pipes.© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Nitrogen Doped Carbons Derived From Graphene Aerogel Templated Triazine-Based Conjugated Microporous Polymers for High-Performance Supercapacitors

Conjugated microporous polymers (CMPs) have attracted intensive attention owing to their permanent nanoporosity, large surface area and possibility for functionalization, however their application in energy storage suffers from poor conductivity and low hetero-atom content. Here, we demonstrate a hybrid of conjugated microporous polymers and graphene aerogel with improved conductivity. After treating at 800°C in NH3, the nitrogen content increases to 9.8%. The resulting microporous carbon exhibits a significant rise in supercapacitive performance up to 325 F g−1, 55% higher than pristine triazine-based CMPs, with energy density up to 12.95 Wh kg−1. Moreover, it has high stability with 99% retention after 10,000 cycles at 5 A g−1. The synergy of hierarchical porous structure, graphene-based conduction path and high percentage of hybridization with nitrogen ensures effective ion/electron transport and diffusion, making NH3-treated graphene aerogel/CMP hybrid a promising electrode material in high-performance supercapacitor

Solar Response and Long‐Term Trend of Midlatitude Mesopause Region Temperature Based on 28 Years (1990–2017) of Na Lidar Observations

We present midlatitude solar response and linear trend from Colorado State University/Utah State University Na lidar nocturnal temperature observations between 1990 and 2017. Along with the nightly mean temperatures (_Ngt), we also use the corresponding 2‐hr means centered at midnight (_2MN), resulting in vertical trend profiles similar in shapes as those previously published. The 28‐year trend from _Ngt (_2MN) data set starts from a small warming at 85 km, to cooling at 87 (88) km, reaching a maximum of 1.85 ± 0.53 (1.09 ± 0.74) at 92 (93) km and turns positive again at 102 (100) km. The 6‐month winter trend is much cooler than the 4‐month summer trend with comparable solar response varying around 5 ± 1 K/100 SFU throughout the profile (85–105 km) with higher summer values. We explore the observed summer/winter trend difference in terms of observed gravity wave heat flux heating rate at a nearby station and the long‐term trend of gravity wave variance at a midlatitude. Between 89 and 100 km, the lidar trends are within the error bars of the Leibniz Middle Atmosphere (LIMA) summer trends (1979–2013), which are nearly identical to the lidar‐Ngt trend. We address the need of long data set for reliable analysis on trend, the extent of trend uncertainty due to possible tidal bias, the effect of a Pinatubo/episodic function, and the impact of stratospheric ozone recovery

Synthesis of Enantiomers of Chiral Ester Derivatives Containing an Amide Group and their Chiral Recognition by ¹H NMR Spectroscopy

Enantiomers of Chiral Ester Derivatives Containing an Amide Group and Possessing One or Two Stereogenic Centers Were Prepared from L- and D-Α-Amino Acids, and Glycine with (S)- and (R)-Mandelic Acid for Probing their Chiral Recognition as a New Class of Chiral Guests by 1H NMR Spectroscopy, Since Chiral Ester Derivatives Have Been Rarely Used as Chiral Substrates for Chiral Recognition by 1H NMR Technology. the Results Indicated that These Chiral Ester Derivatives Have Been Successfully Differentiated in the Presence of Tetraaza Macrocyclic Chiral Solvating Agents (TAMCSAs) 1 A–1 C. in Order to Better Understand their Chiral Discriminating Behavior, Job Plots, Association Constants (Ka), and Theoretical Calculations of (S,S)-G1 and (R,R)-G1, as a Representative Example, Were Performed, respectively. in Order to Evaluate their Practical Application, the 1H NMR Spectra of G1 and G9 with Various Optical Purities Were Measured (Up to 98 % Ee). in This Work, a Practical Strategy Has Been Effectively Established for Chiral Recognition of Chiral Ester Derivatives Containing an Amide Group and Possessing One or Two Chiral Centers in the Presence of Tetraaza Macrocyclic Chiral Solvating Agents 1 A–1 C by Means of 1H NMR Spectroscopy