Two models to estimate the density of organic cocrystals.

Two models for predicting the density of organic cocrystals composed of energetic organic cocrystals and general organic cocrystals containing nitro groups were obtained. Sixty organic cocrystals in which the ratio of component molecules is 1 : 1 were studied as the dataset. Model-I was based on the artificial neural network (ANN) to predict the density of the cocrystals, which used (six) input parameters of the component molecules. The root mean square error (RMSE) of the ANN model was 0.033, the mean absolute error (MAE) was 0.023, and the coefficient of determination (R 2) was 0.920. Model-II used the surface electrostatic potential correction method to predict the cocrystal density. The corresponding RMSE, MAE, and R 2 were 0.055, 0.045, and 0.716, respectively. The performance of Model-I is better than that of Model-II.

From tortoise-shell-like molecular segments to C(4n)H(2n)N(2n) (n = 3-8) cages stabilized by alkenyl: a theoretical study.

The C(4n)H(2n)N(2n) (n = 3-8) cage molecules with D(nh) symmetry and their nitrated products, C(4n)N(4n)O(4n) (n = 3, 4, 5) and C(4n)H(n)N(3n)O(2n) (n = 4, 6, 8) were studied by DFT at the B3LYP/cc-pVDZ level. Their geometrical structures, ground-state energies, and heats of formation have been investigated. They exhibit an obvious cage effect. Hirshfeld partitioning charges in momentum space give evidence of high strained energy in the title compounds. Their orbital energy and frontier orbital shape and electrostatic potential calculation are also studied. Investigation of heat of formation and NICS analysis reveal that C(24)H(12)N(12) is the most stable molecule among title compounds with D(nh) symmetry. Their half nitrated products are predicted as a promising candidate for high energy matter.

Structure and relative stability of drum-like C4nN2n n = 3-8) cages and their hydrogenated products C4nH4nN2n (n = 3-8) cages.

The drum-like C4nNn (n = 3-8) cages and corresponding hydrogenated products C4n H4nN2n (n = 3-8) are studied at the DFT B3LYP/6-31G** level. Their structures, energies, and vibrational frequencies have been investigated. Comparison of heat of formation reveals that C32N16 with D8h symmetry in the C4nN2n (n = 3-8) series is a promising candidate as high energy density matter. The calculation of the DeltaG and DeltaH for the hydrogenation of C4nN2n (n = 3-8) shows that it is an exothermic reaction at 298 K and the C4nH4nN2n (n = 3-8) species are more stable than C4nN2n (n = 3-8) species. The analysis of molecular orbital and selected bond lengths of N-N and C-C provides another insight about their stability. Combined with the nucleus-independent chemical shifts (NICS) calculation, it is indicated that molecular stability for cage-shaped molecules depends on not only aromatic character but also the cage effect.

Molecular dynamics simulation study for LRH-1: interaction with fragments of SHP and function of phospholipid ligand.

The liver receptor homolog-1 (LRH-1) is an important transcriptional factor in the process of cholesterol and bile acids metabolism. In this article, molecular dynamics simulation for six systems with total 60 ns is employed to study LRH-1. LRH-1/phospholipid and LRH-1/SHP (fragments) interactions are analyzed by counting atomic contact number, identifying hydrogen bonds, and estimating binding free energies (by MM-PB/SA and N-mode analysis). Through integrating our modeling result with previous experimental data, deeper understandings to LRH-1/SHP interaction are obtained, and functions of the phospholipid ligand in LRH-1 are proposed.

3D-QSAR studies with the aid of molecular docking for a series of non-steroidal FXR agonists.

The farnesoid x receptor (FXR) has become a potential drug target for treating cholesterol-related and bile acid-related diseases recently. In this paper, 3-dimensional quantitative structure-activity (structure-affinity and structure-efficacy) relationships are investigated for a series of non-steroidal agonists (fexaramine series) by using the comparative molecular field analysis (CoMFA), where molecular docking method (FlexX) is employed to construct molecular superimposition maps. A proposal to design some new agonists is discussed lastly.

Evaluation on the safety of a group A + C meningococcal polysaccharide vaccine / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the safety of a group A + C meningococcal polysaccharide vaccine as part of a phase IV clinical trial.</p><p><b>METHODS</b>The study area was divided into 108 clusters according to the principle of cluster randomization, stratified and paired sampling methods. 54 out of 108 clusters served as observation groups were administered A + C vaccine, while the rest 54 groups were administered Vi polysaccharide vaccine. An adverse event surveillance system was established to monitor the adverse events following the vaccination campaign. Identical form and methods were used for data collection to investigate the adverse events following the vaccination of both A+ C vaccine and Vi vaccine.</p><p><b>RESULTS</b>34,543 people were vaccinated, including 18,167 of whom received A + C vaccine, while the other 16,376 received Vi vaccine. The rates of immediate injection reaction and unsolicited non-serious adverse events from A + C vaccine group were 0.44% and 0.38% while of Vi vaccine group were 0.79% and 0.73% respectively. At the solicited adverse event survey on 3-day-post-vaccination, 1239 vaccinees were followed-up including 771 received A + C vaccine and 468 received Vi vaccine. The local injection reaction rate of A + C vaccine group on the 1st day was significantly higher (X2 = 13.98, P = 0.0002) than that of Vi vaccine group. Neither the local injection reaction rate nor the system reaction rate between both groups was significantly different on 2nd and 3rd day, post vaccination. It was not statistically different when comparing fever onset rate between those who received vaccine and those who did not, in each vaccine group. There were no serious adverse events observed.</p><p><b>CONCLUSION</b>Results showed that the side effects of A + C vaccine and the Vi vaccine were mild and safe for vaccination campaigns targeting on populations at different age.</p>