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Herein, three novel cocrystals of 1-hydroxy-2-naphthoic acid: tetramethylpyrazine, 1-hydroxy-2-naphthoic acid:1,10-phenanthroline, and 1-hydroxy-2-naphthoic acid:1,4-bis(imidazol-1-ylmethyl)benzene (L2) were obtained by crystallization in methanol–water mixed solvent via a slow evaporation method. The cocrystalline products 1−3 were carried out by a range of techniques, including single-crystal X-ray diffraction, Fourier transform–infrared spectroscopy, elemental analysis, and thermogravimetric testing. We analyzed the crystal structures of the cocrystals 1−3 and found that weak interactions C–H···X (X = O or π) were of great importance in the process of self-assembly as well as strong and conventional hydrogen bonds (N–H···O, O–H···N, O–H···O), leading to a stable and diverse multidimensional supramolecular architecture. It is worth noting that a series of ring motifs with different sizes were explored in the crystal structures of the above complexes, such as R22(5), R22(7), R22(8), R23(13), R24(16), R44(16), R44(22), and so on. The classical and robust supramolecular synthon intermolecular bond between acid and pyridine (acid···pyridine) heterosynthon R22(7), commonly found in organic solids containing carboxylic acids with other N-containing heteroaromatics, was further demonstrated to be involved in the construction of the hydrogen-bond networks of cocrystal 1. The thermogravimetric technique used in this study proved that the mass losses of these three cocrystals were closely related to the strength of the hydrogen bonds in the package fraction.

Juvenile idiopathic arthritis (JIA) is highly heterogeneous in terms of etiology and clinical presentation with ambiguity in JIA classification. The advance of high-throughput omics technologies in recent years has gained us significant knowledge about the molecular mechanisms of JIA. Besides a minor proportion of JIA cases as monogenic, most JIA cases are polygenic disease caused by autoimmune mechanisms. A number of HLA alleles (including both HLA class I and class II genes), and 23 non-HLA genetic loci have been identified of association with different JIA subtypes. Omics technologies, i.e., transcriptome profiling and epigenomic analysis, contributed significant knowledge on the molecular mechanisms of JIA in addition to the genetic approach. New molecular knowledge on different JIA subtypes enables us to reconsider the JIA classification, but also highlights novel therapeutic targets to develop a cure for the devastating JIA.