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This report describes rapid changes to instructional materials, assessment, and technology use in a flipped college-level organic chemistry course in response to the sudden COVID-19 campus closures and midsemester transition to remote learning. The instructors modified in-class instructional materials to accommodate students' preference for text-based over audiovisual engagement in the remote environment. The pros and cons of three approaches to administering remote organic chemistry exams are presented. Issues related to equitable incorporation of technology and maintaining academic integrity are discussed.

The structure of the title compound, C27H46N2, at 93 K has monoclinic (P21/n) symmetry. The title compound was prepared by treatment of 2-(2,6-diisopropylphenyl)-3,3-dimethyl-2-azaspiro[4.5]dec-1-en-2-ium hydrogen dichloride with two equivalents of lithium diethylamide. Characterization of the title compound by single-crystal X-ray diffraction and 1H and 13C NMR spectroscopy is presented. Formation of the diethylamine adduct of the cyclic(alkyl)(amino)carbene (CAAC) was unexpected, as deprotonation using lithium diisopropylamide results in free CAAC formation.

Bis(perfluorocatecholato)silane Si(cat(F))2 was prepared, and stoichiometric binding to Lewis bases was demonstrated with fluoride, triethylphosphine oxide, and N,N'-diisopropylbenzamide. The potent Lewis acidity of Si(cat(F))2 was suggested from catalytic hydrosilylation and silylcyanation reactions with aldehydes. Mechanistic studies of hydrosilylation using an optically active silane substrate, R-(+)-methyl-(1-naphthyl)phenylsilane, proceeded with predominant stereochemical retention at silicon, consistent with a carbonyl activation pathway. The enantiospecificity was dependent on solvent and salt effects, with increasing solvent polarity or addition of NBu4BAr(F)4 leading to a diminished enantiomeric ratio. The medium effects are consistent with an ionic mechanism, wherein hydride transfer occurs prior to silicon-oxygen bond formation.

Category: Lesser Toes; Midfoot/Forefoot Introduction/Purpose: Traditional K-Wire fixation of the proximal interphalangeal joint during correction of hammertoes is associated with various complications including loss of fixation, recurrence of deformity, pin tract infection and patient dissatisfaction due to the pin. At least 20 devices designed expressly for the purpose of fusing the interphalangeal joint of the lesser toes exist. Cost of the implants can range from $450 to $2000 per implant (when disposable instruments are included in the cost.) We hypothesized that a permanent intraosseous K-Wire bridging the proximal and middle phalanx would perform in an equivalent manner to many commercially available implants with a large potential for cost savings. Methods: A modified DuVries hammertoe correction procedure through a dorsal approach including resection of both joint surfaces. A 2mm or 1.6mm K-wire is then cut and placed into the intramedullary canals of the phalanges bridging the PIP joint (IP). A snug extensor mechanism repair affords compression and rotational control. External pins (EP) were used if the diaphyseal canal was less than 1.6mm. A retrospective review of medical records and radiographs of all patients undergoing hammertoe correction over three years by a single surgeon. 50 patients (28 Women, 12 Men) and 53 feet (2 bilateral) with mean age 66 (range 34 – 84) who had a minimum 6-month follow-up were available for study. 112 toes were corrected. Osseous union or stable fibrous union were the desired results with non-union, deformity recurrence and/or the need for revision being noted as failure. Average follow-up was 21.7 months (6 – 54). Results: Results: Of the 93 IP fixations, there were 68 fusions, 22 stable fibrous unions, and 3 non-unions. Of the 19 External pins there were, 11 fusions, 3 stable fibrous unions and 5 non-unions. 5 Patients required revision which was done by bone grafting and compression with an intramedullary screw. Success was noted in 96% of IP fixation and 74% of external pin fixations. Conclusion: Permanent internal K-Wire fixation for hammertoe correction is a viable option for fixation of hammertoe deformity outperforming traditional temporary K-wire fixation and resulting in good clinical results comparable to other commercially available implants. Given the negligible cost of this implant, the potential cost savings to the medical system is great. K-Wires are readily available worldwide and this technique may useful in countries where resources do not allow use of expensive implants.

We report hydroboration of carbodiimide and isocyanate substrates catalyzed by a cyclic carbodiphosphorane catalyst. The cyclic carbodiphosphorane outperformed the other Lewis basic carbon species tested, including other zerovalent carbon compounds, phosphorus ylides, an N‐heterocyclic carbene, and an N‐heterocyclic olefin. Hydroborations of seven carbodiimides and nine isocyanates were performed at room temperature to form N‐boryl formamidine and N‐boryl formamide products. Intermolecular competition experiments demonstrated the selective hydroboration of alkyl isocyanates over carbodiimide and ketone substrates. DFT calculations support a proposed mechanism involving activation of pinacolborane by the carbodiphosphorane catalyst, followed by hydride transfer and B−N bond formation. [ABSTRACT FROM AUTHOR]

Rosanna Qualizza1, Cristoforo Incorvaia2, Romualdo Grande3, Eleni Makri2, Luigi Allegra31Allergy Service, 2Allergy/Pulmonary Rehabilitation, Istituti Clinici di Perfezionamento, 3IRCCS Fondazione Cà Granda, Milan, ItalyBackground: Toxocara canis is an intestinal nematode affecting dogs and cats, which causes human infection when embryonated eggs excreted in dog feces are ingested. Humans are paratenic hosts. Although the larvae do not develop into adult worms in the human body, they may migrate to various tissues and organs where they can survive for several years, giving rise to several clinical symptoms, which can present in allergy-like form.Methods: Over 5 years, we examined 9985 patients referred for suspected allergies, based on symptoms such as dermatitis, urticaria, rhinitis, asthma, and conjunctivitis; 753 patients who had allergy tests negative or unrelated to clinical history were tested for seropositivity to T. canis by enzyme-linked immunosorbent assay (ELISA) or Western blotting (WB).Results: In 240 patients (31.8%), ELISA or WB or both tests were positive for T. canis immunoglobulin G (IgG) antibodies: in particular, 64 of them (26.7%) were positive to ELISA, 110 (45.8%) to WB, and 66 (27.5%) to both tests. Asthma was the most common clinical presentation. Two thirds of patients underwent subsequent anthelmintic therapy and showed a complete remission of symptoms and, in 43% of patients retested by ELISA and WB, became negative to Toxocara.Conclusion: These findings strongly suggest that T. canis plays a significant role in inducing chronic symptoms presenting as suspected allergies.Keywords: suspected allergy, Toxocara canis, enzyme-linked immunosorbent assay, Western blotting, anthelmintic therapy

Neuroplasticity in the mesolimbic dopaminergic system is critical for behavioral adaptations associated with opioid reward and addiction. These processes may be influenced by cholinergic transmission arising from the laterodorsal tegmental nucleus (LDTg), a main source of acetylcholine to mesolimbic dopaminergic neurons. To examine this possibility we asked if chronic systemic morphine administration affects expression of genes in ventral and ventrolateral periaqueductal gray at the level of the LDTg using rtPCR. Specifically, we examined gene expression changes in the area of interest using Neurotransmitters and Receptors PCR array between chronic morphine and saline control groups. Analysis suggested that chronic morphine administration led to changes in expression of genes associated, in part, with cholinergic neurotransmission. Furthermore, using a quantitative immunofluorescent technique, we found that chronic morphine treatment produced a significant increase in immunolabeling of the cholinergic marker (vesicular acetylcholine transporter) in neurons of the LDTg. Finally, systemic administration of the nonselective and noncompetitive neuronal nicotinic antagonist mecamylamine (0.5 or 2 mg/kg) dose-dependently blocked the expression, and to a lesser extent the development, of locomotor sensitization. The same treatment had no effect on acute morphine antinociception, antinociceptive tolerance or dependence to chronic morphine. Taken together, the results suggest that endogenous nicotinic cholinergic neurotransmission selectively contributes to behavioral sensitization to morphine and this process may, in part, involve cholinergic neurons within the LDTg.