Dehydro­abietic acid

The title compound [systematic name: (1R,4aS,10aR)-7-iso­prop­yl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octa­hydro­phen­anthrene-1-carboxylic acid], C20H28O2, has been isolated from disproportionated rosin which is obtained by isomerizing gum rosin with a Pd-C catalyst.. Two crystallographically independent mol­ecules exist in the asymmetric unit. In each mol­ecule, there are three six-membered rings, which adopt planar, half-chair and chair conformations. The two cyclo­hexane rings form a trans ring junction with the two methyl groups in axial positions. The crystal structure is stabilized by inter­molecular O—H⋯O hydrogen bonds

Benefits of trees in tropical cities

10.1126/science.aan6642Science3566344124

15-Hydroxy­ethyl-19-isopropyl-5,9-dimethyl-14,16-dioxo-15-aza­penta­cyclo­[10.5.2.01,10.04,9.013,17]nona­dec-18-ene-5-carboxylic acid

The title compound, C26H37NO5, which was synthesized from monoethano­lamine and maleopimaric acid, consists of two fused and unbridged cyclo­hexane rings. They form a trans ring junction with a chair conformation. The two methyl groups are in axial positions. In the crystal, inter­molecular O—H⋯O hydrogen bonds link adjacent mol­ecules into a layer structure. Two C—H⋯O interactions are also present

7-Isopropyl-1,4a-dimethyl-1,2,3,4,4a,5,6,7,8,9,10,10a-dodeca­hydro­phenan­threne-1-carboxylic acid

The title compound, C20H32O2, has been isolated from hydrogenated rosin. There are two independent mol­ecules in the asymmetric unit. In each mol­ecule, the cyclo­hexane ring assumes a chair conformation, while the two cyclo­hexene rings adopt half-chair and envelope conformations. Inter­molecular O—H⋯O hydrogen bonding between carboxyl groups links pairs of independent mol­ecules into dimers

Study on Roadway Parameters of Broken Compound Roof of Gently Inclined Thick Coal Seam

AbstractThis paper through investigation of the geological conditions of Da’ Anshan's coal mine, according to the special of the broken compound roof on inclined thick coal seam, select the anchor suspension theory and composite beam theory, design the roadway support's anchor parameters, and apply the finite element software ADINA carry out simulation analysis, through the contrast of analysis and engineering data, proved that the design of support parameters is reasonably and practicable. The research has practical value and can guide similar projects

Bis{2-[bis­(3,5-dimethyl-1H-pyrazol-1-yl-κN 2)meth­yl]pyridine-κN}cobalt(II) dinitrate

The central CoII ion in the title complex, [Co(C16H19N5)2](NO3)2, is located on a twofold rotation axis and has a slightly distorted octa­hedral coordination sphere. It is bonded to six N atoms from two 2-[bis­(3,5-dimethyl-1H-pyrazol-1-yl)meth­yl]pyridine ligands. In the crystal, mol­ecules are linked by weak C—H⋯O inter­actions

catena-Poly[[tetra­aqua­zinc(II)]-μ-2,2′-dihydr­oxy-5,5′-diazenediyldibenzoato]

In the title compound, [Zn(C14H8N2O6)(H2O)4]n, the 2,2′-dihydr­oxy-5,5′-diazenediyldibenzoate ligand acts as a carboxyl­ate bridge, leading to the formation of a polymeric chain running along the [10] direction. The ZnII atom is hexa-coordinated in a distorted octa­hedral geometry by six O atoms [Zn—O = 2.055 (4)–2.132 (3) Å] from two carboxylate ligands and four water mol­ecules. The crystal packing is stabilized by inter­molecular O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds, and two π–π inter­actions. The centroid–centroid distances are 3.803 (16) and 3.804 (17) Å

Tissue-Specific Expression of the Chicken Calpain2 Gene

We quantified chicken calpain 2 (CAPN2) expression in two Chinese chicken breeds (mountainous black-bone chicken breed [MB] and a commercial meat type chicken breed [S01]) to discern the tissue and ontogenic expression pattern and its effect on muscle metabolism. Real-time quantitative PCR assay was developed for accurate measurement of the CAPN2 mRNA expression in various tissues from chickens of different ages (0, 2, 4, 6, 8, 10, and 12 weeks). Results showed that the breast muscle and leg muscle tissues had the highest expression of CAPN2 compared to the other tissues from the same individual (P < .05). Overall, the CAPN2 mRNA level exhibited a “rise” developmental change in all tissues. The S01 chicken had a higher expression of the CAPN2 mRNA in all tissues than the MB chicken. Our results suggest that chicken CAPN2 expression may be related to chicken breeds and tissues