Butane-1,4-diyl bis-(pyridine-4-carboxyl-ate).

The mol-ecule of the title compound, C(16)H(16)N(2)O(4), lies about an inversion centre; the butane chain adopts an extended zigzag conformation. The dihedral angle between the pyridine ring and the adjacent COO group is 3.52 (s14)°.

A Comparative Randomized Prospective Clinical Study on Modified Erich Arch Bar with Conventional Erich Arch Bar for Maxillomandibular Fixation.

INTRODUCTION: Erich arch bar used for maxillomandibular fixation (MMF) since decades has several disadvantages such as risks of injury, additional operating room time, and gingival trauma. To overcome these downsides, modified Erich arch bar was introduced; however, there is not much available literature, indicating the efficacy of modified Erich arch bar over that of conventional arch bar wire. Therefore, the present study focuses on comparing efficiency of modified arch bar with conventional arch bar. MATERIALS AND METHODS: This comparative randomized study was conducted on 32 patients that required MMF and were divided into Group A patients who received intermaxillary fixation (IMF) with modified Erich arch bars and Group B patients with conventional Erich arch bars. The parameters recorded were average surgical time required, wire prick injuries, IMF stability, occlusal stability, screw loosening, oral hygiene status, and vitality response of the teeth. The variables were statistically analyzed using Student's t-test and Wilcoxon signed-rank test. RESULTS: The wire prick injury, intraoperative time noted in Group A was significantly reduced in comparison to Group B (P < 0.0001). Debris indices were significantly good in Group A in comparison to Group B (P < 0.0001). Nonvitality response of tooth was significantly more in Group B than in Group A patients (P < 0.05). DISCUSSION: The efficiency of modified Erich arch bar group was superior to the conventional arch bar with very limited restrictions.

Ameloblastic carcinoma: A case series.

Ameloblastic carcinoma is a rare odontogenic tumor exhibiting not only features of ameloblastoma, but also features of carcinoma. Clinical dissemination of this lesion is more aggressive and rapid than that of ameloblastoma and it can metastasize to the lung or regional lymph node. Histologically, there are features of both ameloblastoma and carcinoma. <50 cases have been reported until 2011. We report a series of six cases with our treatment modalities.

Synthesis of (+)-lycoricidine by the application of oxidative and regioselective ring-opening of aziridines.

A highly stereoselective total synthesis of (+)-lycoricidine has been described. The salient features of this synthesis are the one-pot elimination followed by allylation reaction, ring-closing metathesis, stereoselective aziridine formation, Dess-Martin periodinane, and silica gel mediated oxidative ring-opening of aziridine to form alpha,beta-unsaturated ketone (allyl amine) and intramolecular Heck cyclization.