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Introduction: Brain abscesses (BA) form approximately 8% of intracranial masses in developing and 1-2% in western countries. Fungal BA (FBA) are aggressive and represent a catastrophic manifestation compared to protozoan and bacterial BA. Diagnosis of FBA is rare and usually done postmortem. Objectives: The present retrospective study analyses the clinico-mycological aspects of FBA presented to our neurosurgical services over a period of 38 years, from January 1979 to April 2017. Materials and Methods: Patients diagnosed as definitive cases of FBA were included in the study. Clinico- demographic and microbiological data were collected from medical records. BA pus was examined for fungal etiology using standard microbiological procedures. Results: During the period of 38 years out of total 2,916 brain abscesses, 29 cases of FBA were diagnosed with an overall incidence rate of 0.99% per year. Cladophialophora bantiana (44%) was the most predominant isolate followed by Aspergillus spp and others. Male preponderance was seen with a male:female ratio of 4.8:1. There was no predilection for any age group. Headache, limb weakness and fever were the most common presentations. Amphotericin B was given in 44.8% of cases. Craniotomy with excision (48.2%) was the predominant surgical management. Outcome was fatal in 62% of the cases. Conclusion: Neurotropic C. bantiana is the predominant isolate causing fungal brain abscess. The incidence and trends of fungi causing brain abscess do not show significant change. Young immunocompetent outdoor working males were predominantly susceptible to fungal infection. Advance in the diagnostic modalities show promising in diagnosis of FBA. High index of suspicion with early diagnosis, prompt antifungal therapy and aggressive surgical management is required as FBA are associated with high mortality rate.

The results of an investigation into whether or not eclipse shadow bands have an atmospheric origin are presented. Using high altitude balloon and ground-based photodiode arrays during the 21 August 2017 total solar eclipse, data revealing the light patterns before and after totality were collected. These data were then analyzed using spectrograms. Both at the altitude of the balloon and on the ground, a sustained ~ 4.5 Hz signal was detected a few minutes before and after totality. This signal was coherent over a scale greater than 10 cm and detected in four separate balloon photodiodes and 16 ground photodiodes. At higher frequencies, up to at least 30 Hz, brief chaotic signals that were disorganized as a function of time were detected on the ground, but not at the altitude of the balloon and appeared mostly uncorrelated over a length scale of 10 cm. Some of our ground arrays utilized red and blue filters, but neither the sustained 4.5 Hz signal nor the higher frequency signals showed a strong dependence on filter color. On the ground we made a video of the shadow bands on a scaled white screen. We judged that the bands were roughly parallel to the orientation of the bright thin crescent Sun before and after totality and inferred that their propagation velocity was about v ~ 59 cm /s. Shadow band signals other than the sustained signal at ~ 4.5 Hz are consistent with atmospheric scintillation theory. These results are surprising. Based on accounts in the literature we expected to confirm the atmospheric scintillation theory of eclipse shadow bands, but instead we detected a sustained ~ 4.5 Hz signal at both high altitude and on the ground. This signal cannot be due to atmospheric scintillation and we ran a check to make sure this signal is not an artifact of our electronics. We recommend that additional searches for eclipse shadow bands be made at high altitude in the future., Comment: 11 pages, 8 figures. Accepted for publication, JASTP

The fluorophilicity of a series of hydrocarbon and fluorocarbon-functionalized nicotinic acid esters (nicotinates) is measured from their partitioning behavior (log K(P)) in the biphasic solvent system of perfluoro(methylcyclohexane) (PFMC) and toluene. The chain length of the hydrocarbon or fluorocarbon alkyl group of the ester ranges from one to twelve carbon atoms. Knowledge of the fluorophilicity of these solutes is relevant to the design of these prodrugs for fluorocarbon-based drug delivery. The experimental log K(p) values range from -1.72 to -3.40 for the hydrocarbon nicotinates and -1.64 to 0.13 for the fluorinated nicotinates, where only the prodrug with the longest fluorinated chain (2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl nicotinic acid ester) partitions preferentially into the fluorinated phase (log K(p) = 0.13). Predictions of the partition coefficients using solubility parameters calculated from group contribution techniques or molecular dynamics simulation are in reasonable agreement for the perhydrocarbon nicotinates and short chained perfluorinated nicotinates (≈ 0.3%-39% deviation). Significant deviations from experimental partition coefficients (greater than 100%) are observed for the longest chain perfluoroalkyl nicotinates.

A series of colored hydrocarbon and fluorocarbon tagged 1-fluoro-4-alkylamino-anthraquinones and 1,4-bis-alkylamino-anthraquinone probe molecules were synthesized from a (fluorinated) alkyl amine and 1,4-difluoroanthraquinone to aid in the development of fluorous separation applications. The anthraquinones displayed stacking of the anthraquinone tricycle and interdigitation of the (fluorinated) alkyl chains in the solid state. Furthermore, intramolecular N–H⋯O hydrogen bonds forced the hydrocarbon and fluorocarbon tags into a conformation pointing away from the anthraquinone tricycle, with the angle of the tricycle plane normal and the main (fluorinated) alkyl vector ranging from 1° to 39°. Separation of the probe molecules on fluorous silica gel showed that the degree of fluorination of the probe molecules plays only a minor role with most eluents (e.g., hexane/ethyl acetate and methyl nonafluorobutyl ethers/ethyl acetate). However, toluene as eluent caused a pronounced separation by degree of fluorination for fluorocarbon, but not hydrocarbon tagged probe molecules on both silica gel and fluorous silica gel. These studies suggest that hydrocarbon and fluorocarbon tagged anthraquinones are useful probe molecules for the development of laboratory scale fluorous separation applications.

Anti HIV and antitumor compounds, harman and substituted harmans have been synthesized using electrocyclization reactions as key steps. A one-pot reaction sequence was used to furnish these compounds in good overall yield.