1-Ethyl-4-hydr­oxy-9-aza­tricyclo­[7.4.1.02,7]tetra­deca-2,4,6-trien-8-one

In the mol­ecule of the title compound, C15H19NO2, the six-membered dihydro­pyridinone ring assumes a screw-boat conformation. In the crystal structure, mol­ecules are linked via O—H⋯O hydrogen bonding between hydr­oxy and carbonyl groups, forming supra­molecular chains along the a axis

A Tabu Search algorithm for the vehicle routing problem with discrete split deliveries and pickups

The Vehicle Routing Problem with Discrete Split Deliveries and Pickups is a variant of the Vehicle Routing Problem with Split Deliveries and Pickups, in which customers’ demands are discrete in terms of batches (or orders). It exists in the practice of logistics distribution and consists of designing a least cost set of routes to serve a given set of customers while respecting constraints on the vehicles’ capacities. In this paper, its features are analyzed. A mathematical model and Tabu Search algorithm with specially designed batch combination and item creation operation are proposed. The batch combination operation is designed to avoid unnecessary travel costs, while the item creation operation effectively speeds up the search and enhances the algorithmic search ability. Computational results are provided and compared with other methods in the literature, which indicate that in most cases the proposed algorithm can find better solutions than those in the literature

3-[(3S)-3-Ethyl-1-methyl­azepan-3-yl]phenyl N-(4-fluoro­phen­yl)carbamate

The asymmetric unit of the title compound, C22H27FN2O2, a (−)-S-meptazinol derivative, contains two mol­ecules. The azepane ring adopts a similar twist chair form in both mol­ecules, while the dihedral angles between the two benzene rings are 88.17 (14) and 89.93 (14)° in the two mol­ecules. The absolute configuration of the mol­ecule was determined from the synthetic starting material. The crystal structure is stabilized by classical inter­molecular N—H⋯O hydrogen bonds

2-Methyl-1,2,3,4-tetra­hydro­isoquinolin-6-yl N-phenyl­carbamate

In the mol­ecule of the title compound, C17H18N2O2, the piperidine ring adopts a half-chair form. The two benzene rings are individually planar and make a dihedral angle of 53.90°. The crystal structure is stabilized by inter­molecular N—H⋯N hydrogen bonds and π–π stacking inter­actions (centroid–centroid distance = 3.962 Å)

Field and Laboratory Studies on Pathological and Biochemical Characterization of Microcystin-Induced Liver and Kidney Damage in the Phytoplanktivorous Bighead Carp

Field and experimental studies were conducted to investigate pathological characterizations and biochemical responses in the liver and kidney of the phytoplanktivorous bighead carp after intraperitoneal (i.p.) administration of microcystins (MCs) and exposure to natural cyanobacterial blooms in Meiliang Bay, Lake Taihu. Bighead carp in field and laboratory studies showed a progressive recovery of structure and function in terms of histological, cellular, and biochemical features. In laboratory study, when fish were i.p. injected with extracted MCs at the doses of 200 and 500 μg MC-LReq/kg body weight, respectively, liver pathology in bighead carp was observed in a time dose-dependent manner within 24 h postinjection and characterized by disruption of liver structure, condensed cytoplasm, and the appearance of massive hepatocytes with karyopyknosis, karyorrhexis, and karyolysis. In comparison with previous studies on other fish, bighead carp in field study endured higher MC doses and longer-term exposure, but displayed less damage in the liver and kidney. Ultrastructural examination in the liver revealed the presence of lysosome proliferation, suggesting that bighead carp might eliminate or lessen cell damage caused by MCs through lysosome activation. Biochemically, sensitive responses in the antioxidant enzymes and higher basal glutathione concentrations might be responsible for their powerful resistance to MCs, suggesting that bighead carp can be used as biomanipulation fish to counteract cyanotoxin contamination

5,6-Dimethyl-1,2,4-triazin-3-amine

In the crystal structure of the title compound, C5H8N4, adjacent mol­ecules are connected through N—H⋯N hydrogen bonds, resulting in a zigzag chain along [100]. The amino groups and heterocyclic N atoms are involved in further N—H⋯N hydrogen bonds, forming R 2 2(8) motifs