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The unique thermogenic capacity of brown adipocyte makes it an attractive target for antiobesity treatments. Several epigenetic regulators can control brown adipocyte development. In this study, we show that SIRT5, a member of the sirtuins, is required for brown adipocyte differentiation and essential for brown adipogenic gene activation in vitro. Furthermore, we find out that knockdown of SIRT5 reduces intracellular α-ketoglutarate concentration, which leads to elevated H3K9me2 and H3K9me3 levels at promoter regions of Pparγ and Prdm16 loci. Finally, we discover that SIRT5 knockout mice on the Sv129 background exhibit less browning capacity in subcutaneous white adipose tissue compared with controls and show apparent cold intolerance, suggesting that SIRT5 can modulate the browning process in vivo. Thus, our study uncovers a new biological function of SIRT5 in brown adipocyte differentiation and a mechanism by which SIRT5 regulates brown adipogenic gene activation at least partly through an indirect effect on histone modifications. Our study extends the linkage between epigenetics and cell differentiation. [ABSTRACT FROM AUTHOR]

AMP-activated protein kinase (AMPK) is an energy sensor of metabolism that is an attractive therapeutic target for type 2 diabetes mellitus and metabolic syndrome. Using a homogeneous scintillation proximity assay (SPA), we identified a new small-molecule AMPK activator, ZLN024, which allosterically stimulated active AMPK heterotrimers and the inactive α1 subunit truncations α1 (1–394) and α1 (1–335) but not α1 (1–312). AMPK activation by ZLN024 requires the pre-phosphorylation of Thr-172 by at least one upstream kinase and protects AMPK Thr-172 against dephosphorylation by PP2Cα. ZLN024 activated AMPK in L6 myotubes and stimulated glucose uptake and fatty acid oxidation without increasing the ADP/ATP ratio. ZLN024 also activated AMPK in primary hepatocytes, decreased fatty acid synthesis and glucose output. Treatment of db/db mice with 15 mg/kg/day ZLN024 improved glucose tolerance; liver tissue weight, triacylglycerol and the total cholesterol content were decreased. The hepatic transcriptional level of G6Pase, FAS and mtGPAT were reduced. The transcription of genes involved in fatty acid oxidation and the mitochondrial biogenesis of muscle tissue were elevated. The ACC phosphorylation was increased in muscle and liver. This study provides a novel allosteric AMPK activator for functional study in vitro and in vivo and demonstrates that AMPK allosteric activators could be a promising therapeutic approach for type 2 diabetes mellitus and metabolic syndrome. [ABSTRACT FROM AUTHOR]

Heterogeneousreactions on mineral aerosols remain an importantsubject in atmospheric chemistry because of their role in alteringthe properties of particles and the budget of trace gases. Yet, therole of coadsorption of trace gases onto mineral aerosols and potentialsynergistic effects are largely uncertain, especially synergisticeffects between inorganic and organic gas-phase pollutants. In thisstudy, synergistic effects between HCOOH and SO2were investigatedfor the first time using in situ diffuse-reflectance infrared Fouriertransform spectroscopy (DRIFTS). It was found that the heterogeneousreaction of HCOOH is hindered significantly by coexisting SO2. The total amount of formate decreased, whereas the total amountof sulfate was not affected during coadsorption on the surface ofα-Fe2O3. Futhermore, part of the formateon the surface was catalytically decomposed to CO2by α-Fe2O3with the help of SO2. These resultssuggest a possible mechanism for the observed correlations betweensulfate and carboxylate in the atmosphere. [ABSTRACT FROM AUTHOR]

Despite increased awareness of the role played by heterogeneousreactions of formic acid on mineral aerosol, the experimental determinationof how these atmospheric reaction rates vary with temperature remaina crucially important part of atmosphere science. Here we report thefirst measurement of heterogeneous uptake of formic acid on α-Al2O3as a function of temperature (T= 240–298 K) at ambient pressure using diffuse reflectanceinfrared Fourier transform spectroscopy (DRIFTS). From the analysisof the spectral features, crystalline HCOOH was identified at lowtemperature besides common product (formate ions) on the surface.It was also interesting to find that crystalline HCOOH can continueto react with α-Al2O3. The reaction mechanismsat both room and low temperature were discussed. Furthermore, thereactive uptake coefficients were acquired and found to increase withdecreasing temperature. Finally, the atmospheric lifetime of formicacid because of heterogeneous loss on mineral aerosol was estimatedat temperatures related to the upper troposphere. [ABSTRACT FROM AUTHOR]

Background: Painless gastroscopy is a widely used diagnostic and therapeutic technology in clinical practice. Propofol combined with opioids is a common drug for painless endoscopic sedation and anaesthesia. In clinical work, adverse drug reactions of anaesthesia schemes are often one of the important areas of concern for doctors and patients. With the increase in propofol dosage, the risk of serious adverse drug reactions, such as respiratory depression and hypotension, increases significantly; the use of opioids often causes gastrointestinal reactions in patients after examination, such as nausea, vomiting, delayed recovery of gastrointestinal function and other complications, which seriously affect their quality of life., Aim: To observe the effect of wrist-ankle acupuncture therapy on the anaesthesia regimen and anaesthesia-related complications during and after painless gastroscopy examination., Methods: Two hundred patients were selected and randomly divided into a treatment group ( n = 100) and a control group ( n = 100). Both groups were routinely anaesthetized with the nalbuphine and propofol regimen, gastroscopy began after the patient lost consciousness, and given supportive treatment and vital sign monitoring. If the patient interrupted the surgery due to intraoperative torsion, intravenous propofol was used to relieve his or her discomfort. The treatment group received wrist-ankle acupuncture on this basis., Results: The general data before treatment, American Society of Anesthesiologist (ASA) grade and operation time between the two groups was no significant difference. The Wakeup time, and the Self-ambulation time in the treatment group was significantly faster than that in the control group ( P < 0.05). The total dose of propofol in the treatment group was 109 ± 8.17 mg, significantly lower than that in the control group ( P < 0.05). The incidence of respiratory depression and hypotension was not significantly different, but the incidence of hiccups was significantly lower than that in the control group ( P < 0.05). After the examination, the incidence of nausea, vomiting, abdominal distension, and abdominal pain was 11%, 8%, 6%, and 5%, respectively, which was significantly lower than that in the control group ( P < 0.05). In addition, both the operators and the patients were more satisfied with this examination, with no significant difference between the groups ( P > 0.05)., Conclusion: Wrist-ankle acupuncture treatment can optimize the painless gastroscopy and anaesthesia scheme, reduces propofol total dose; shortens patient Wakeup time and Self-ambulation time, improves patient compliance and tolerance, is beneficial to clinical application., Competing Interests: Conflict-of-interest statement: All the authors declare that they have no conflict of interest with this work., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)

Multiphase acid-catalyzed oxidation by hydrogen peroxide has been suggested to be a potential route to secondary organic aerosol (SOA) formation from isoprene and its gas-phase oxidation products, but the kinetics and chemical mechanism remain largely uncertain. Here we report the first measurement of uptake of methacrolein into aqueous solutions of sulfuric acid and hydrogen peroxide in the temperature range of 253-293 K. The steady-state uptake coefficients were acquired and increased quickly with increasing sulfuric acid concentration and decreasing temperature. Propyne, acetone, and 2,3-dihydroxymethacrylic acid were suggested as the products. The chemical mechanism is proposed to be the oxidation of carbonyl group and C═C double bonds by peroxide hydrogen in acidic environment, which could explain the large content of polyhydroxyl compounds in atmospheric fine particles. These results indicate that multiphase acid-catalyzed oxidation of methacrolein by hydrogen peroxide can contribute to SOA mass in the atmosphere, especially in the upper troposphere.

In the title salt, C(23)H(26)N(4) (2+)·2C(6)H(2)N(3)O(7) (-), the dihedral angle between the imidazolium rings in the dication is 69.9 (1)°. The aromatic ring of the benzyl group is almost perpendicular to the N-heterocyclic ring that is directly connected to it [dihedral angles = 83.2 (2) and 77.3 (3)°].

The title compound, [Cd(NO(3))(2)(C(9)H(12)N(4))(2)](n), has a one-dimensional double-bridged chain polymer structure with a 16-membered macrometallacyclic tetragonal structural motif. The Cd(II) ion occupies a crystallographic inversion centre and is coordinated by four equatorial N atoms from four distinct bis(2-methylimidazol-1-yl)methane ligands and two apical nitrate O atoms to form a slightly distorted octahedral coordination geometry.